ArticlePDF Available

Extreme lateral interbody fusion - XLIF

June 2009
Current Orthopaedic Practice 20(3):238–251

June 2009
20(3):238–251

DOI:10.1097/BCO.0b013e3181a32ead

Authors:

Jason Billinghurst

Behrooz A Akbarnia

University of California, San Diego

Anterior and posterior approaches for lumbar interbody fusion can be associated with a number of serious complications. Interest in minimally invasive approaches for interbody fusion has increased in recent years, with the goal of decreasing complications and patient morbidity. The goal of minimally invasive spine surgery is to decrease operative time, decrease blood loss, improve cosmesis, shorter hospital stays and faster recovery time. Extreme lateral interbody fusion (XLIF) is a relatively new technique whereby access to the disc space is achieved through a minimally invasive lateral, retroperitoneal, trans-psoas approach. The nerves of the lumbar plexus reside within the psoas, and the technique is dependent upon real-time electromyographic monitoring. The purpose of this review is to present an overview of the XLIF technique, with particular attention paid to indications, advantages, biomechanics, and early clinical and radiographic results.

(A) The patient is placed in the lateral decubitus position with the greater trochanter over the table break, and secured in place with tape. (B) The table is flexed to increase the distance between the ribs and the iliac crest. (A reproduced with permission from NuVasive, San Diego, CA).

…

(A) A lateral fluoroscopic image is obtained to ensure that the direct lateral skin incision is centered over the target disc space. The posterolateral incision is located four fingerbreadths posterior to the direct lateral incision. (B) The skin is marked appropriately. (B reproduced with permission from NuVasive, San Diego, CA).

…

(A) With a gentle sweeping motion, the surgeon's finger is used to release the adhesions between the peritoneum anteriorly, and the psoas and abdominal wall. (B) The psoas is palpable lateral to the vertebral body and disc space. (Reproduced with permission from NuVasive, San Diego, CA).

…

The surgeon's finger is turned upwards to the direct lateral incision and the skin is incised. (Reproduced with permission from NuVasive, San Diego, CA).

…

(A) The initial dilator is placed through the direct lateral incision. (B) The surgeon's finger safely guides the initial dilator onto the lateral aspect of the psoas. (Reproduced with permission from NuVasive, San Diego, CA).

…

Figures - uploaded by Jason Billinghurst

Content may be subject to copyright.

Content uploaded by Jason Billinghurst

Content may be subject to copyright.

Spine

Extreme lateral interbody fusion - XLIF

Jason Billinghurst

and Behrooz A. Akbarnia

INTRODUCTION

Interbody fusion involves the placement of a structural

implant (spacer, allograft, or cage) within the disc space

after a complete discectomy and preparation of end-

plates. Lumbar interbody fusion, as originally described by

Capener in the 1930s, used an anterior approach to the

lumbar spine.

Cloward

introduced posterior lumbar inter-

body fusion (PLIF) in 1945 for the treatment of lumbar disc

herniations. Transforaminal lumbar interbody fusion (TLIF)

was reﬁned and popularized by Harms and Jeszensky

and

uses a unilateral posterior approach to the anterior column.

More recently Pimenta popularized the lateral approach

to interbody fusion, or extreme lateral interbody fusion

(XLIF).

Nowadays, various types of bone grafts and bone

graft extenders also are available that can be placed within

and around the implant to help promote fusion.

Interbody spine fusion has several theoretical advantages

over traditional posterolateral fusion. Interbody fusion

allows for a much larger area for fusion than is available with

posterolateral fusion. Because the graft is placed anterior to

the instantaneous axis of rotation, it is exposed to compres-

sive rather than tensile forces, which is a more favorable

environment for bone fusion. Pseudarthrosis rates after

posterolateral fusion range from 14–21%.

5,6

Fusion rates

after instrumented interbody fusions vary depending on

technique, interbody implant, graft material and the use

of supplemental instrumentation. In general, reported fusion

rates after interbody fusions are considerably higher than

those seen after posterolateral fusions.

7–11

Compared to traditional posterolateral fusion, interbody

fusion also is advantageous from a biomechanical perspec-

tive. Without interbody support, normal physiologic loads

can exceed the bending strength and stiffness of posterior

pedicle screw constructs.

Anterior column reconstruction

with structural interbody grafts provides immediate segmen-

tal stability, thereby unloading the posterior segmental

instrumentation and increasing the endurance limit of the

construct.

13,14

The indications for lumbar interbody fusion are essentially

the same as those for traditional posterolateral fusion and

include degenerative disc disease, trauma, tumor, infection,

deformity and instability. More recently, interbody fusion

has been used in discogenic low-back pain; however, this is

the most controversial indication for lumbar interbody

fusion.

The goals of interbody fusion are to attain a solid fusion

and to restore disc space height, foraminal dimensions, and

coronal and sagittal balance. Most commonly, interbody

SPECIAL FOCUS

ABSTRACT

Anterior and posterior approaches for lumbar interbody fusion

can be associated with a number of serious complications.

Interest in minimally invasive approaches for interbody fusion

has increased in recent years, with the goal of decreasing com-

plications and patient morbidity. The goal of minimally invasive

spine surgery is to decrease operative time, decrease blood loss,

improve cosmesis, shorter hospital stays and faster recovery time.

Extreme lateral interbody fusion (XLIF) is a relatively new tech-

nique whereby access to the disc space is achieved through a

minimally invasive lateral, retroperitoneal, trans-psoas approach.

The nerves of the lumbar plexus reside within the psoas, and the

technique is dependent upon real-time electromyographic

monitoring. The purpose of this review is to present an overview

of the XLIF technique, with particular attention paid to indica-

tions, advantages, biomechanics, and early clinical and radio-

graphic results.

Keywords

XLIF, lateral approach, interbody fusion, minimally invasive,

spinal deformity

Spine Fellow, San Diego Center for Spinal Disorders, La Jolla, California

Clinical Professor, Department of Orthopaedics, University of California,

San Diego, Medical Director, San Diego Center for Spinal Disorders, La

Jolla, California

Correspondence to Behrooz A. Akbarnia, MD, San Diego Center for Spinal

Disorders, 4130 La Jolla Village Drive #300, La Jolla, CA 92037

Tel: +858 678 0610; fax: +858 678 0007; e-mail: akbarnia@ucsd.edu

1940-7041 ß2009 Wolters Kluwer Health | Lippincott Williams & Wilkins

238 Current Orthopaedic Practice Volume 20 Number 3 May/June 2009

fusions are performed through either an anterior or posterior

approach to the lumbar spine. Both may be associated with

signiﬁcant approach-related complications. Complications

of posterior approaches (PLIF, TLIF) may include pseudar-

throsis, graft dislodgement, and neurologic injury.

The

extensive muscle stripping and denervation associated with

the traditional posterior midline approach also can lead

to atrophy, chronic dysfunction of the lumbar paraspinal

musculature and failed back syndrome.

16– 19

Anterior lumbar

interbody fusion (ALIF) requires mobilization of the

abdominal contents, and most spine surgeons today require

the assistance of a general or vascular access surgeon.

Even so, complication rates of ALIF range from 2.8– 80%

and most frequently involve vascular injury, somatic neuro-

logic injury, deep venous thrombosis and sexual dysfunc-

tion.

20– 28

Less commonly, ureteral injury, bowel injury,

lumbar sympathetic dysfunction, wound dehiscence and

hernias have been reported.

20,23,29

The complication rate

increases signiﬁcantly if the anterior approach is used for

revision surgery.

Recently, more attention has been given to alternative, less

invasive techniques that minimize approach-related compli-

cations and patient morbidity. XLIF is one relatively new

technique that appears to accomplish this goal. The purpose

of this review is to give a general overview of XLIF. Particular

attention is given to indications, surgical technique, advan-

tages, and potential complications of this approach in the

surgical treatment of spinal disorders.

MINIMALLY INVASIVE APPROACHES TO

LUMBAR INTERBODY FUSION

Minimally invasive spine (MIS) surgery has been increasing

in popularity in recent years. With improved instrumenta-

tion and retractor systems, spine surgeons can now perform a

vast array of procedures previously only possible through

large, open approaches, using MIS techniques. In general, the

potential advantages of MIS techniques include smaller

incisions, less damage to soft-tissue structures, improved

cosmesis, decreased blood loss, shorter hospital stays, less

postoperative pain and faster recovery time.

MIS techniques potentially offer additional advantages

speciﬁc to interbody fusion. MIS TLIF for example uses a

unilateral paramedian, muscle-splitting approach to the facet

of interest. The entire procedure is performed through a

tubular retractor system. By avoiding the extensive muscle

stripping required with the traditional posterior midline

approach, the hope is to lower the incidence of chronic pain

and fatigue symptoms, or ‘‘fusion disease.’’ Further, by pre-

serving the integrity of the posterior soft-tissue envelope, the

risk of adjacent segment degeneration and junctional disease

should, theoretically, be lower. A short-term outcome study

available in the literature on minimally invasive approaches

to interbody fusion demonstrated good intermediate-term

(6– 12 months) results in 85% of patients after MIS TLIF.

EXTREME LATERAL INTERBODY FUSION (XLIF)

The lateral approach to interbody fusion, or XLIF has been

popularized by Osgur et al.

It is a relatively new technique

whereby access to the disc space is achieved through a

minimally disruptive lateral, retroperitoneal, trans-psoas

approach to the spine. Blunt dissection of the psoas major

muscle is achieved with the use of a series of dilators. The

nerves of the lumbar plexus lie within the substance of the

psoas and real-time electromyographic (EMG) monitoring is

performed to direct safe passage through this corridor.

The lateral approach to interbody fusion has many advan-

tages over anterior and posterior approaches. The lateral

approach avoids the risks of anterior surgery. Mobilization

of the abdominal contents and great vessels is not required.

Injury to the hypogastric sympathetic plexus and injury to

the gastrointestional and genitourinary systems are similarly

avoided. Accordingly, there is usually no need for an

approach surgeon. The lateral approach also avoids all of

the posterior approach-related complications seen with open

TLIF and PLIF. Extensive muscle stripping and denervation

are avoided. Retraction of the neural elements is not

required, avoiding the potential for associated neurologic

and dural related complications.

In terms of technical difﬁculty, the lateral approach is

relatively simple to perform, with a rather gradual learning

curve. The lateral approach involves minimal soft-tissue

disruption and is associated with minimal blood loss,

decreased operative time, less postoperative pain, shorter

hospital stays and quicker recovery and return to work.

BIOMECHANICS OF LATERAL INTERBODY

FUSION

There are several important issues related to the biomecha-

nics of interbody fusion that deserve mention. Numerous

biomechanical studies have demonstrated that stand-alone

ALIF does not provide adequate segmental stability, necessi-

tating the use of supplemental ﬁxation.

32– 34

The addition of

an anterior plate, posterior translaminar facet screws, or

posterior transpedicular screws imparts sufﬁcient immediate

stability to anterior lumbar interbody constructs.

35,36

Two recent studies evaluated the biomechanics of inter-

body reconstruction after a lateral approach.

37,38

Kim et al.

showed that both anterior and lateral discectomy cause seg-

mental instability. Stand-alone anterior or lateral interbody

reconstruction with femoral ring allograft restored segmental

stability to that of the intact spine. The addition of a lateral

plate to the lateral interbody construct resulted in a signiﬁ-

cant increase in segmental stability compared with the stand-

alone construct. The addition of posterior pedicle screw

instrumentation to the anterior interbody construct also

resulted in a signiﬁcant increase in segmental stability com-

pared with both the stand-alone anterior interbody construct

and the lateral interbody/plate construct. In another cadaver

study, Bess et al.

demonstrated that stand-alone XLIF con-

structs and various instrumented XLIF constructs (lateral

plate, unilateral pedicle screws, bilateral pedicle screws) all

led to increased stability when compared with theintact spine.

The improved immediate stability seen after lateral inter-

body reconstruction of the cadaveric spine has been attrib-

uted to a number of causes. Tencer et al.

has demonstrated

the destabilizing effect of sectioning the anterior longitudi-

nal ligament (ALL) in calf and human cadaveric spines. The

lateral approach does not violate the ALL as occurs during

Current Orthopaedic Practice 239

anterior discectomy and interbody fusion. Preservation of

this structure likely has an important role in maintaining

segmental stability after lateral discectomy and interbody

reconstruction.

There are no published studies directly comparing the

stability of lateral interbody constructs to posterior interbody

constructs using the PLIF or TLIF technique. However, the

destabilizing effect of unilateral and bilateral hemifactec-

tomy performed during TLIF and PLIF is well known.

40– 42

The lateral approach does not violate the posterior osseoli-

gamentous ring.

The lateral approach allows for a large interbody implant to

be placed. Larger implants more effectively restore foraminal

dimensions, as well as, sagittal and coronal alignments.

Ideally, the implant should span the entire disc space from

medial to lateral, and rest on the peripheral portion of the

endplate, or the ring apophysis. The peripheral portion of the

endplate is stronger than the central portion. Therefore,

larger implants also enable endplate stresses to be distributed

over a larger surface area. Larger surface areas equate to lower

stresses at the bone-implant interface. Interbody implants

placed though a lateral approach can therefore provide

greater resistance to implant subsidence, which is a major

complication associated with the ALIF technique.

PATIENT SELECTION AND SURGICAL

INDICATIONS

In his initial description of the XLIF procedure, Osgur et al.

used the technique in patients with degenerative disc disease

and axial low back pain. Candidates for the procedure were

essentially those who would otherwise be considered for

ALIF. Patients were not considered candidates for the pro-

cedure if they demonstrated severe central canal stenosis,

signiﬁcant scoliotic deformity, or moderate to severe

spondylolisthesis.

The indications for the XLIF procedure have since been

expanded to include patients with a variety of spinal path-

ologies. Exposure of the L5-S1 disc space is limited by the iliac

crests and so the lateral approach may only be used in

situations requiring anterior column stabilization above

L5. The XLIF approach can be used to treat patients with

degenerative disc disease, complex spinal deformity and

spondylolisthesis. Thoracic or lumbar corpectomy and lum-

bar total disc replacement also can be accomplished through

the lateral approach. Patients requiring revision after either

prior failed fusion surgery (pseudarthrosis, adjacent level

disease) or revision of failed total disc replacement surgery

are all candidates for the lateral approach. Finally, the lateral

approach also has been used as an alternative approach to the

thoracic spine. Thoracic disectomy and corpectomy can be

performed with minimal variation in the surgical technique.

Accordingly, thoracic disc herniations, thoracolumbar

trauma, tumors and infections also may be treated through

a lateral approach.

SURGICAL TECHNIQUE FOR INTERBODY

FUSION

The XLIF procedure consists of ﬁve key steps: 1) patient

positioning; 2) retroperitoneal access; 3) transpsoas access

and disc exposure; 4) discectomy and disc space prep-

aration; and 5) interbody implant sizing and placement.

Compulsive attention to detail is essential to ensure

patient safety. Strict adherence to these guidelines will

achieve reproducible results and maximize the potential

for success.

Patient Positioning

The patient is placed on a radiolucent operating table capable

of ﬂexing near its midportion. After endotracheal intubation,

general anesthesia is administered and lines are placed. The

patient is placed in the true lateral decubitus position with

the greater trochanter positioned directly over the table

break. An axillary roll is placed, and all bony prominences

are padded. The patient is secured to the operating room

table using tape, and the table is ﬂexed to increase the

distance between the ribs and the iliac crest (Figure 1 A

and B). Fluoroscopy is used to ensure that good, unobstructed

images of the disc space of interest have been obtained on

both the crosstable anteroposterior (AP) and lateral views.

The table is rotated as necessary to provide true AP and lateral

images of the disc space. The skin is prepared and draping is

performed in the usual manner.

Retroperitoneal Access

The lateral approach uses a one or a two-incision technique,

the latter of which is the authors’ preferred method. The

two-incision approach includes a direct lateral incision and

a posterolateral incision. The direct lateral incision is the

working portal. It is centered over the target disc space, as

240 Volume 20 Number 3 May/June 2009

FIGURE 1. (A) The patient is placed in the lateral decubitus position with

the greater trochanter over the table break, and secured in place with tape.

(B) The table is ﬂexed to increase the distance between the ribs and the iliac

crest. (A reproduced with permission from NuVasive, San Diego, CA).

conﬁrmed on the lateral ﬂuoroscopic image. The skin is

marked appropriately (Figure 2 A and B). If two levels are

to be treated, then the direct lateral skin incision is made

halfway between the two target levels. For multilevel pro-

cedures, more than one skin incision may be required.

The posterolateral incision is used to gain access to the

retroperitoneal space. It guides the safe passage of the

dilators and retractor system through the retroperitoneal

space. The incision is located approximately four ﬁnger-

breadths posterior to the direct lateral incision. It is located

just anterior to the intersection of the erector spinae and

the abdominal oblique muscles. The skin and subcu-

taneous tissue are incised. Blunt dissection of the abdomi-

nal obliques is carried out, spreading in line with the

corresponding muscle ﬁbers. After the ﬁnal layer of fascia

is incised, the retroperitoneal space has been entered.

Current Orthopaedic Practice 241

FIGURE 2. (A) A lateral ﬂuoroscopic image is obtained to ensure that the direct lateral skin incision is centered over the target disc space. The posterolateral

incision is located four ﬁngerbreadths posterior to the direct lateral incision. (B) The skin is marked appropriately. (B reproduced with permission from

NuVasive, San Diego, CA).

FIGURE 3. (A) With a gentle sweeping motion, the surgeon’s ﬁnger is used to release the adhesions between the peritoneum anteriorly, and the psoas and

abdominal wall. (B) The psoas is palpable lateral to the vertebral body and disc space. (Reproduced with permission from NuVasive, San Diego, CA).

Using a gentle sweeping motion, the surgeon’s ﬁnger is

used to release the peritoneum from the psoas and abdomi-

nal wall, allowing the abdominal contents to fall forward

and away from the operative ﬁeld. The psoas is palpable

just lateral to the vertebral body and disc space (Figure 3 A

and B). Posteriorly, the tip of the surgeon’s ﬁnger will come

into contact with the transverse processes of the lumbar

spine. The surgeon’s ﬁnger is then turned upwards to the

direct lateral skin incision, and the skin is incised

(Figure 4). The fascia is incised over the target disc space.

The initial dilator is introduced through this incision, and

the surgeon’s ﬁnger is used to guide it safely through the

retroperitoneal space and onto the lateral surface of the

psoas (Figure 5 A and B). Biplanar ﬂuoroscopy ensures that

the initial dilator is centered over the disc space of interest

(Figure 6 A and B).

The one-incision technique, if employed, utilizes the direct

lateral incision only. It may be favored for cosmetic reasons,

however, it is important to note that adhesions between

the peritoneum and the abdominal wall may place the

peritoneum and its contents at risk. Surgeons utilizing the

one-incision technique must use extreme caution during

the initial approach to the retroperitoneal space.

Transpsoas Access and Disc Exposure

The nerves of the lumbar plexus are located within the

substance of the psoas muscle. Anatomic studies have shown

that they are most often found in the posterior third of the

242 Volume 20 Number 3 May/June 2009

FIGURE 4. The surgeon’s ﬁnger is turned upwards to the direct lateral

incision and the skin is incised. (Reproduced with permission from NuVasive,

San Diego, CA).

FIGURE 5. (A) The initial dilator is placed through the direct lateral incision.

(B) The surgeon’s ﬁnger safely guides the initial dilator onto the lateral

aspect of the psoas. (Reproduced with permission from NuVasive, San

Diego, CA).

FIGURE 6. Lateral (A) and anteroposterior (B) ﬂuoroscopic images ensure that the initial dilator is centered over the target disc space. (Reproduced with

permission from NuVasive, San Diego, CA).

muscle.

44,45

In addition, the genitofemoral nerve lies on

the anterior surface of the psoas. Safe passage through the

psoas is entirely dependent upon EMG monitoring. The XLIF

dilators have stimulating electrodes at their tips. A stimulat-

ing clip is attached to the other end, allowing real time

Neurovision EMG monitoring (Nuvasive, San Diego, CA)

as the psoas is traversed (Figure 7). To minimize the risk to

the lumbar plexus, the dilators should enter the psoas at the

junction of the anterior and middle thirds. A radiolucent

blade or tubular retractor system is placed over the largest

dilator and docked on the lateral aspect of the disc space.

Care should be taken to ensure that the abdominal contents

are protected anteriorly during this maneuver. The retractor

system is then secured to the operating table and expanded.

The retractor should not be expanded past the midportion of

the vertebral body to minimize the possibility of segmental

vessel injury (Figure 8).

Discectomy and End Plate Preparation

Disc space preparation is carried out in the usual fashion with

a few important caveats. A lateral annulotomy is performed

followed by a complete discectomy using pituitary rongeurs

and curettes (Figure 9). Over-aggressive decortication of the

Current Orthopaedic Practice 243

FIGURE 7. Real time Neurovision EMG monitoring is performed as the dilators are passed through the psoas. The surgeon is alerted to the proximity of the

nerves of the lumbar plexus by a series of audible and visual signals. (Reproduced with permission from NuVasive, San Diego, CA).

endplates should be avoided to minimize the risk of graft

subsidence. The contralateral annulus is released by passing a

Cobb elevator completely across the disc space. Both the

anterior annulus and the posterior annulus are preserved.

It is essential to ensure that the patient has not shifted

position during the course of the procedure and that instru-

ments are placed directly across the disc space. This is best

conﬁrmed on a cross-table true AP ﬂuoroscopic image. Any

deviation can result in oblique passage of instruments across

the disc space and potentially catastrophic neurologic or

vascular injury.

Interbody Implant Placement

The appropriate size interbody implant is determined after

trial positioning. The implant is ﬁlled with graft material

(Figure 10). Under biplanar ﬂuoroscopic guidance, the

implant is carefully impacted completely across the anterior

to middle one-third of the disc space (Figure 11). Placing the

implant over the outer rim of the end plate on each side

provides maximum support because of the strength of the

ring apophysis (Figure 12). Supplemental lateral plate ﬁx-

ation may be used in favor of posterior ﬁxation depending on

individual patient factors and surgeon judgment. Hemostasis

is achieved, and the wounds are irrigated and closed in layers.

A drain is not typically necessary (Figure 13).

POSTOPERATIVE CARE

After surgery patients typically exhibit all of the beneﬁts of

minimally invasive surgery. They are mobilized on the ﬁrst

244 Volume 20 Number 3 May/June 2009

FIGURE 8. (A) The retractor is placed over the largest dilator and docked on the lateral aspect of the disc space. (B) The retractor is secured to the operating

table and expanded. (Reproduced with permission from NuVasive, San Diego, CA).

FIGURE 9. Complete discectomy and endplate preparation is carried out

using a series of pituitary rongeurs and curettes. (Reproduced with per-

mission from NuVasive, San Diego, CA).

postoperative day. A TLSO brace may be used at the surgeon’s

discretion. Most patients are discharged home 1 to 3 days

after an isolated XLIF procedure.

DISADVANTAGES AND POTENTIAL

COMPLICATIONS OF XLIF

XLIF seeks to avoid the anterior and posterior approach-

related complications outlined above. However, as with

any other operative technique, it is not without its own

unique set of disadvantages and potential complications.

The XLIF procedure cannot be used to treat pathology invol-

ving the L5-S1 intervertebral disc; exposure is limited by the

ipsilateral iliac crest. Furthermore, XLIF relies on indirect

decompression of the neural elements through restoration

of foraminal dimensions. Patients with severe stenosis from

facet or ligamentum hypertrophy may require an additional

posterior approach to achieve complete decompression.

Potential complications of the lateral approach are mostly

related to the psoas and the nerves of the lumbar plexus that

lie within it. The nerves of the lumbar plexus and the

genitofemoral nerve are at risk as the psoas is traversed.

The real-time EMG monitoring during this critical stage of

the procedure can reliably detect the proximity of neural

structures and signal the surgeon to redirect.

Still, post-

operative groin or thigh dysesthesias may occur in some

Current Orthopaedic Practice 245

FIGURE 10. Interbody cage ﬁlled with the surgeon’s choice of bone graft or

any of a variety of commercially available bone graft substitutes.

FIGURE 11. Intraoperative photograph (A) and schematic representation (B) of the implant carefully impacted across the anterior to middle one-third of the

disc space. (B reproduced with permission from NuVasive, San Diego, CA).

FIGURE 12. The implant should rest on the outer rim of the endplate

to minimize the risk of subsidence. (Reproduced with permission from

NuVasive, San Diego, CA).

patients. In one recent series of patients with degenerative

lumbar scoliosis, three of 12 patients experienced transient

groin or thigh dysesthesias.

47

These all resolved within

6 weeks. In our experience, occasionally these may even last

up to 6 months. Direct trauma to the psoas also frequently

leads to transient hip ﬂexor pain and weakness during the

early postoperative period. Patients should be informed of

these possibilities during the preoperative discussion.

Major neurologic, vascular, or implant related compli-

cations of the XLIF procedure have not been published.

Still, meticulous attention to detail and to the techniques

outlined in this review, are essential to minimize the risk

of complications.

CLINICAL EXPERIENCE WITH XLIF

The safety and efﬁcacy of XLIF has been demonstrated by a

number of researchers who have presented their experience

with XLIF at various national and international meet-

ings.

46,48– 52

In the largest of these series, Wright

reported

the results of XLIF in 145 patients treated by 20 surgeons in

the United States. All patients underwent XLIF for the treat-

ment of lumbar degenerative disc disease. The number of

levels treated varied from one to four (72% single level, 22%

two levels, 5% three levels, and 1% four levels). Interbody

spacers (poly-ether-ether-ketone (PEEK) 86%, allograft 8%, or

cage 6%) were used in conjunction with bone morphogenic

protein (52%), demineralized bone matrix (39%), or auto-

graft (9%). Twenty percent of the cases were stand-alone

interbody, 23% used a lateral rod-screw construct, and

58% used posterior pedicle screws. Average operative time

was 74 minutes (range, 30–150 minutes). Average blood loss

was 88 ml (range, 25–450 ml). The author noted a 46%

incidence of EMG-directed instrument repositioning during

the trans-psoas approach. Most patients ambulated on the

day of surgery and were discharged on the ﬁrst postoperative

day. No major complications were reported.

There are still only a few published studies on outcomes

after XLIF. Those that are available are mostly small case

series. Despite their small numbers, these studies have

demonstrated the safe and effective application of the XLIF

procedure in patients with degenerative disc disease and

adult deformity.

4,47,53

At our institution, XLIF has been performed successfully

and reliably in patients with degenerative conditions,

spondylolisthesis and adult deformity (primary and revision

cases). We recently reported the early results of the XLIF

approach in 13 patients (mean age 60.5 years, range,

37– 84 years) who had multilevel (two or more levels) XLIF

for the treatment of adult lumbar scoliosis greater than

30 degrees.

A mean of three levels (range, two to ﬁve)

were treated and all were combined with posterior spinal

fusion and instrumentation. Average follow-up was 9 months

(range, 2–28 months). Radiographically, signiﬁcant improve-

ments in lumbar curve magnitude and lumbar lordosis were

achieved. Two XLIF-related complications occurred: one graft

required revision due to migration, and one hernia occurred at

the site of the XLIF incision, which did not require operative

treatment. All cases of psoas muscles weakness or thigh numb-

ness or pain resolved in patients who had a minimum of

6 months follow-up. Short-term postoperative visual analog

scale (VAS), Scoliosis Research Society (SRS)-22 and Oswestry

Disability Index (ODI) scores were improved signiﬁcantly in

comparison to preoperative scores.

To date, there exists no large, multicenter, Level I or Level II

studies that examine clinical outcomes of patients after the

XLIF approach. Similarly, no published data exist comparing

XLIF to other traditional or minimally invasive approaches to

lumbar interbody fusion (Figures 14–17; case examples).

CONCLUSION

The goal of any interbody fusion technique is to achieve a

solid fusion, restore disc space height and foraminal dimen-

sions, and correct any segmental (sagittal or coronal) imbal-

ance. All of these goals must be achieved while minimizing

the potential for complications and morbidity. The XLIF

procedure appears to accomplish these goals through a mini-

mally disruptive lateral retroperitoneal trans-psoas approach

to the spine. The anterior and posterior approach-related

complications are avoided. Neurophysiologic monitoring is

an essential component of the procedure to ensure avoidance

of the lumbar plexus complications. Minor complications

such as lumbar plexus neuropraxia and hip ﬂexor weakness

may occur but are transient.

The XLIF procedure is biomechanically advantageous in

that it preserves the anterior and posterior osseoligamen-

tous structures of the spine and allows for insertion of a

large interbody implant. Restoration of foraminal dimen-

sions and coronal and sagittal balance can be achieved

while minimizing the risk of subsidence and implant

failure. Further biomechanical research is necessary to bet-

ter elucidate the role of supplemental posterior or lateral

instrumentation.

Early reports have shown that XLIF appears to accomplish

all of the goals of interbody fusion, safely and effectively.

Large, evidenced based, multi-center studies are needed to

provide intermediate and long-term term outcome data

with this new technique. As with all new technologies,

246 Volume 20 Number 3 May/June 2009

FIGURE 13. Appearance of the incisions following closure. Final antero-

posterior and lateral ﬂuoroscopic images of the implant (inset).

Current Orthopaedic Practice 247

FIGURE 14. A 63-year-old woman with low back pain and neurogenic claudication, who previously underwent an L4-5 instrumented fusion for degenerative

spondylolisthesis. Anteroposterior (A) and lateral (B) radiographs and sagittal T2 weighted MRI (C) 3 years postoperatively demonstrate severe adjacent

segment degeneration at L2-3 and L3-4, with anterolisthesis of L3 on L4. The patient underwent a single stage L2-3 and L3-4 XLIF, followed by posterior

decompression, and extension of the fusion to L2. Post-operative anteroposterior (D) and lateral (E) radiographs demonstrate reduction of the listhesis and

restoration of disc space height, foraminal dimensions, and lumbar lordosis.

248 Volume 20 Number 3 May/June 2009

FIGURE 15. A 36-year-old man with chronic, axial low back pain secondary to L4-5 degenerative disc disease, unresponsive to nonoperative treatment. The

patient had a positive discogram with concordant pain at L4-5 and a negative control at L5-S1. Pre-operative, anteroposterior (A) and lateral (B) radiographs,

and sagittal T2-weighted MRI (C). The patient underwent an L4-5 XLIF with supplementary lateral plate ﬁxation. Post-operative anteroposterior (D) and lateral

(E) radiographs.

Current Orthopaedic Practice 249

FIGURE 16. A 35-year-old woman with idiopathic scoliosis who had undergone posterior spinal fusion and Harrington instrumentation from T3-L4 in 1984.

She had a history of chronic low back pain and right anterior thigh pain for 6 months. Anteroposterior (A) and lateral (B) radiographs demonstrate lumbar

ﬂatback deformity, sagittal imbalance, and adjacent segment degeneration at L4-5. Axial CT myelogram at L4-5 (C) demonstrates right foraminal stenosis. She

had a positive discogram with concordant pain at L4-5, with a negative control at L5-S1. She underwent L4-5 XLIF, followed by partial removal of the

Harrington rod, L3-5 laminectomies and foraminotomies, and posterior fusion and pedicle screw instrumentation, L2-5. Postoperative anteroposterior (D) and

lateral (E) radiographs demonstrate restoration of segmental lordosis (inset).

eventually this outcome data will need to be compared

against traditional and other minimally invasive approaches

to lumbar interbody fusion. Finally, it is extremely important

for those who want to use this technique to be trained

appropriately and to identify a mentor with whom they

can observe surgery and communicate regarding proper

indications and possible management questions.

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Current Orthopaedic Practice 251

Using an Extreme Lateral Interbody Fusion (XLIF) in Revising Failed Transforaminal Lumbar Interbody Fusion (TLIF) With Exchange of Cage

Article

Full-text available

Mar 2021

Minimally invasive techniques have gained popularity in spine surgery in recent years. Extreme lateral interbody fusion (XLIF) is one of these techniques. The rapid increase in the use of this approach in either primary or revision surgeries is related to its several advantages including less operative time, less blood loss and reduced length of hospital stay with fast recovery. We report a case of a failed transforaminal lumbar interbody fusion (TLIF) in L4-L5 level, one year after the primary procedure with persistent pain due to failed fusion. Underwent revision, by using XLIF with the removal of old cage and exchange with new large cage. Revision of failed interbody fusion can be achieved through anterior, posterior or lateral approach. The decision to proceed with either method depends on several factors, including previous surgeries, fibrosis and risk of neurovascular injury and surgeon's preference. XLIF approach should be considered in revision surgeries of failed interbody fusion. As it can provide several advantages compared to anterior or posterior approaches, in terms of better fusion rates and lower risk of neurovascular injuries by avoiding the use of the previous passage.

Vascular injury risk stratification for lateral lumbar interbody fusion (LLIF) at L4–L5: a morphometric study using magnetic resonance imaging

Article

Full-text available

Dec 2023

Background Proper vascular injury risk stratification (VIRS) methods for L4–L5 lateral lumbar interbody fusion (LLIF) surgery have not been well-described. The objective of this study was to propose a novel VIRS method for L4–L5 LLIF surgery via the transpsoas approach. Methods Axial magnetic resonance imaging (MRI) of adult patients were obtained and analyzed. The VIRS scores were assessed using anterior disc line to posterior vessel wall distance, the disc vessel angle (DVA), and the disc edge to vessel distance at the level of L4–L5 disc space. Results Ninety-one consecutive adult patients were included in the study. The right common iliac vein (CIV) had a high risk of injury with both right- and left-sided approaches. The left CIV had a moderate risk with a left-sided approach when the iliocaval confluence was above the L4–L5 disc space but had a high risk when the confluence was at the L4–L5 disc space. The left CIV had a high risk with a right-sided approach when the confluence was above the L4–L5 disc space but had a moderate risk when the confluence was at the L4–L5 disc space. The inferior vena cava (IVC) had a high risk with both right- and left-sided approaches. The aorta had a moderate risk regardless of the right or left-sided approaches. The left common iliac artery (CIA) had a moderate risk with a right-sided approach and a low risk with a left-sided approach. The right CIA had a low risk with both right- and left-sided approaches. Conclusions There are significant vascular anatomic variations at the L4–L5 disc level and a proper VIRS can be performed utilizing a combination of anterior disc line to posterior vessel wall distance, DVA, and disc edge to vessel distance, on the axial MRI.

Rates of Postoperative Complications and Approach-related Neurological Symptoms After L4–L5 Lateral Transpsoas Lumbar Interbody Fusion Compared With Upper Lumbar Levels

Article

Full-text available

Aug 2022

Study design: This was a retrospective comparative study. Objective: To compare the likelihood of approach-related complications for patients undergoing single-level lateral lumbar interbody fusion (LLIF) at L4-L5 to those undergoing the procedure at upper lumbar levels. Summary of background data: LLIF has been associated with a number of advantages when compared with traditional interbody fusion techniques. However, potential risks with the approach include vascular or visceral injury, thigh dysesthesias, and lumbar plexus injury. There are concerns of a higher risk of these complications at the L4-L5 level compared with upper lumbar levels. Materials and methods: A retrospective cohort review was completed for consecutive patients undergoing single-level LLIF between 2004 and 2019 by a single surgeon. Indication for surgery was symptomatic degenerative lumbar stenosis and/or spondylolisthesis. Patients were divided into 2 cohorts: LLIF at L4-L5 versus a single level between L1 and L4. Baseline characteristics, intraoperative complications, postoperative approach-related neurological symptoms, and patient-reported outcomes were compared and analyzed between the cohorts. Results: A total of 122 were included in analysis, of which 58 underwent LLIF at L4-L5 and 64 underwent LLIF between L1 and L4. There were no visceral or vascular injuries or lumbar plexus injuries in either cohort. There was no significant difference in the rate of postoperative hip pain, anterior thigh dysesthesias, and/or hip flexor weakness between the cohorts (53.5% L4-L5 vs. 37.5% L1-L4; P=0.102). All patients reported complete resolution of these symptoms by 6-month postoperative follow-up. Discussion: LLIF surgery at the L4-L5 level is associated with a similar infrequent likelihood of approach-related complications and postoperative hip pain, thigh dysesthesias, and hip flexor weakness when compared with upper lumbar level LLIF. Careful patient selection, meticulous use of real-time neuromonitoring, and an understanding of the anatomic location of the lumbar plexus to the working corridor are critical to success.

Do evoked potentials matter? Pre-pathologic signal change and clinical outcomes with expandable cages in lateral lumbar interbody fusion surgery

Article

Apr 2022
J CLIN NEUROSCI

Minimally Invasive Lateral Lumbar Interbody Fusion (MIS LLIF) is a reliable technique for treatment of degenerative disk disease, foraminal stenosis and spinal deformity. The retroperitoneal transpsoas approach risks lumbar plexus injury that may result in anterior thigh pain, sensory loss and weakness. A prospective study of 64 consecutive patients undergoing MIS LLIF with expandable cages (23 standalone, 41 integrated with lateral plate) using multimodal electrophysiological monitoring was performed. We measured sequential retraction times, complications, patient reported outcome scores and electrophysiologic findings with a minimum 12-month follow-up. Incidence of evoked potential and electromyographic signal change was moderate, and rarely resulted in post-operative neurologic deficit. Evoked potential signal changes were frequently resolved by the un-breaking of the surgical table or repositioning of the retractor. Average retraction times were 24 (15–41) minutes for standalone cages and 30 (15–41) minutes for integrated cages. At follow-up, the vast majority (97%) of patients reported significant clinical improvement post-operatively with only 2 patients reporting postoperative neurologic symptoms and subsequent recovery at 12-months. The present study shows that evoked potentials combined with electromyography is a more sensitive measure of pre-pathologic lumbar plexopathy in LLIF compared to electromyography alone, especially at L3/4 and L4/5 levels. Based on our findings, there is limited clinical indication for routine neural monitoring at rostral lumbar levels. The routine inclusion of multimodal electrophysiological monitoring in lateral transpsoas surgery is recommended to minimise the risk of neural injury by enabling optimal patient and retractor positioning and continued surveillance throughout the procedure.

The impact of cage positioning on lumbar lordosis and disc space restoration following minimally invasive lateral lumbar interbody fusion

Article

Jan 2023
Neurosurg Focus

OBJECTIVE The objective of this study was to evaluate patient and surgical factors that predict increased overall lumbar lordosis (LL) and segmental lordosis correction following a minimally invasive lateral lumbar interbody fusion (LLIF) procedure. METHODS A retrospective review was conducted of all patients who underwent one- or two-level LLIF. Preoperative, initial postoperative, and 6-month postoperative measurements of LL, segmental lordosis, anterior disc height, and posterior disc height were collected from standing lateral radiographs for each patient. Cage placement was measured utilizing the center point ratio (CPR) on immediate postoperative radiographs. Spearman correlations were used to assess associations between cage lordosis and radiographic parameters. Multivariate linear regression was performed to assess independent predictors of outcomes. RESULTS A total of 106 levels in 78 unique patients were included. Most procedures involved fusion of one level (n = 50, 64.1%), most commonly L3–4 (46.2%). Despite no differences in baseline segmental lordosis, patients with anteriorly or centrally placed cages experienced the greatest segmental lordosis correction immediately (mean anterior 4.81° and central 4.46° vs posterior 2.47°, p = 0.0315) and at 6 months postoperatively, and patients with anteriorly placed cages had greater overall lordosis correction postoperatively (mean 6.30°, p = 0.0338). At the 6-month follow-up, patients with anteriorly placed cages experienced the greatest increase in anterior disc height (mean anterior 6.24 mm vs posterior 3.69 mm, p = 0.0122). Cages placed more posteriorly increased the change in posterior disc height postoperatively (mean posterior 4.91 mm vs anterior 1.80 mm, p = 0.0001) and at 6 months (mean posterior 4.18 mm vs anterior 2.06 mm, p = 0.0255). There were no correlations between cage lordotic angle and outcomes. On multivariate regression, anterior cage placement predicted greater 6-month improvement in segmental lordosis, while posterior placement predicted greater 6-month improvement in posterior disc height. Percutaneous screw placement, cage lordotic angle, and cage height did not independently predict any radiographic outcomes. CONCLUSIONS LLIF procedures reliably improve LL and increase intervertebral disc space. Anterior cage placement improves the lordosis angle greater than posterior placement, which better corrects sagittal alignment, but there is still a significant improvement in lordosis even with a posteriorly placed cage. Posterior cage placement provides greater restoration in posterior disc space height, maximizing indirect decompression, but even the anteriorly placed cages provided indirect decompression. Cage parameters including cage height, lordosis angle, and material do not impact radiographic improvement.

Recovery of Bilateral Hip Flexion Weakness Following Extreme Lateral Interbody Fusion Due to Postoperative Pain -A prospective Study

Article

Full-text available

Jun 2022

1. Abstract 1.1. Background Context Extreme lateral interbody fusion (XLIF) is a relatively recent minimally invasive fusion technique of the lumbar spine. A point of criticism is the risk of postoperative weakness of the psoas ascribed to neural injury. We postulate that the resulting hip flexion weakness is merely a temporary phenomenon due to postoperative pain. 1.2. Purpose To examine hip flexion strength in patients undergoing the XLIF procedure and evaluate clinical outcomes. 1.2.1 Design: A prospective single-center cohort study. 1.2.2. Patient Sample: Patients with chronic low back pain due to lumbar degenerative disc disease, degenerative lumbar deformity, and spondylolisthesis for at least 12 months and history of at least 6 months of unsuccessful conservative treatment. 1.2.3. Outcomes Measures: Physiologic Measures: hip flexion strength; Self-reported Measures: low back pain using the visual analogue scale (VAS) and the Oswestry Disability Index (ODI). 1.3. Methods Patients following a one-or two-level XLIF procedure were assessed during a 3-month follow-up period. Measurements of hip flexion strength were performed with a fixed digital dynamometer, both on the operated and the non-operated side, 2 days preoper-atively as well as 2 days, 6 weeks and 3 months postoperatively, by two independent examiners blinded to the side of the lumbar approach. ODI scores and VAS values for low back pain were collected at the indicated time points. The data were evaluated statistically using t-tests and correlation analyses. 1.4. Results From May to December 2018, 17 participants (5 men and 12 women) were included in the study; the average age was 67 years (range 49-82). The lateral transpsoas approach to the lumbar spine was on the right side in 8 patients, and on the left in 9. All procedures were performed between L3 and L5. Hip flexion strength on the operated side was significantly decreased 2 days postoper-atively (p=0.0001) and returned to almost normal values 6 weeks postoperatively. On the non-operated side, strength was also significant lower 2 days postoperatively (p=0.004), recovering almost completely to preoperative values within 3 months. Low back pain VAS score was significantly reduced (p=0.003) 6 weeks postoper-atively, and ODI value decreased from 42% preoperatively to 35% at 6 weeks, and 23% at 3 months after the procedure. Correlation of the VAS score with the hip flexion force was-0.268 (p=0.0087). 1.5. Conclusion The transient psoas muscle weakness following the XLIF procedure observed on the operated side is mainly caused by postoper-ative pain and less by muscular injury, with muscular strength almost returning to baseline values within 6 weeks after the surgery. The postoperative pain seems to be the main cause of the weakness also affecting the non-operated side.

Anterior and Lateral Interbody Techniques for Revision Lumbar Fusion

Chapter

Feb 2024

Revision lumbar fusion is commonly performed in the setting of pseudarthrosis and adjacent segment disease after primary lumbar fusion. Anterior interbody techniques may prove invaluable in this setting by avoiding previously used approaches to the spine, provision of improved stability and surface for fusion, restoration of alignment, and indirect decompression of neural elements. This review aims to discuss the utility of anterior interbody techniques and the technical challenges and considerations in the revision setting.

Extreme Lateral Interbody Fusion: An Observational Study of Functional and Radiological Outcome

Article

Full-text available

Nov 2023

Introduction: Extreme lateral interbody fusion (XLIF) constitutes a minimally invasive procedure employed to address a spectrum of conditions including degenerative disc disorders, trauma, infections, and deformities. Despite its potential, there exists a scarcity of studies exploring perioperative functional and radiological outcomes. This prospective observational study seeks to address this gap by reporting these outcomes in patients treated at the King Faisal Specialist Hospital & Research Centre (KFSHRC) over a mean follow-up period of 5 years. Methods This case series amassed baseline patient data, encompassing gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) classification, operated level, and posterior fixation type. Primary outcome measures encompassed the Oswestry Disability Index (ODI), Roland-Morris Disability Index (RMDI), Euro-Qol (EQ)-5D, visual analog scale (VAS), and EQ-5D index scores. Additionally, the study delved into secondary outcomes encompassing radiological parameters such as sagittal balance, lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence. Results: The study embraced 51 patients, comprising 9 females and 42 males, with a mean age of 58.6 years and a mean BMI of 29.3. The patients were followed for an average of 5.2 years. Stratification according to ASA classification revealed that 11.8% of patients were classified as ASA I, 52.9% as ASA II, and 35.3% as ASA III. The levels of operation included 60.8% at L4-L5, 33.3% at L3-L4, and 5.9% at L2-L3. The fixation techniques employed encompassed 58.8% bilateral and 41.2% unilateral approaches. The analysis of the primary clinical outcomes unveiled statistically significant enhancements in ODI, RMDI, EQ-5D VAS, and EQ-5D index scores. While lumbar lordosis registered a significant decrease, radiological parameters indicated non-significant shifts in pelvic incidence, pelvic tilt, and sacral slope. Conclusion The XLIF procedure emerges as an efficacious and minimally invasive avenue for managing degenerative disc disorders. The reported functional and radiological outcomes prove satisfactory. However, while demonstrably effective, the generation of clinical recommendations necessitates the compilation of results from randomized clinical trials.

Incidence of postoperative neurological deficit with the use of an intraoperative neuromonitoring protocol for lateral lumbar interbody fusion

Article

Nov 2023
J NEUROSURG-SPINE

OBJECTIVE Intraoperative neuromonitoring (IONM) has become commonplace in assessing neurological integrity during lateral approaches to lumbar interbody fusion surgeries. Neuromonitoring is designed to aid surgeons in identifying the potential for intraoperative nerve injury and reducing associated postoperative complications. However, standardized protocols for neuromonitoring have not been provided, and outcomes are not well described. The purpose of this study was to provide a standardized protocol for IONM, and to describe clinical outcomes in a cohort of individuals who underwent lateral lumbar interbody fusion (LLIF) surgery. METHODS A retrospective review of 169 consecutive patients who underwent LLIF surgery at a single institution from October 2014 to October 2016 was performed. Patient characteristics, intraoperative details, clinical outcomes, and postoperative deficits (PODs) were compared between patients who did and did not trigger IONM alerts, and between patients who did and did not demonstrate a POD. A protocol for IONM decision-making was generated based on these observations. RESULTS Most patients (91.7%) underwent surgery for a degenerative spine condition. Twenty-three patients (13.6%) triggered neuromonitoring alerts, and 16 patients (9.5%) demonstrated a POD. Leg pain, back pain, and disability improved significantly (p < 0.045), and 2 patients had both motor and sensory deficits at the 12-week postoperative time point. Patients with a POD demonstrated greater operating room time (p = 0.034) and a greater number of interbody fusion levels (p = 0.015) but were less likely to have triggered a neuromonitoring alert (p = 0.04). There was no association between retractor time and POD (p = 0.98). When an IONM protocol was followed, individuals who experienced a POD were less likely to trigger an alert than those who did not experience a POD (p = 0.04). CONCLUSIONS This study provides a protocol algorithm for IONM alert responses in patients undergoing LLIF surgery. PODs are most associated with multilevel fusion, and patients with alerts had a low rate of persistent deficit. Future research is needed to validate these findings using a more rigorous comparative study design.

Prone Lateral Interbody Fusion: A Narrative Review and Case Report

Article

Feb 2023

Background: Prone transpsoas (PTP) is a novel approach for performing lateral lumbar interbody fusion in a single position. This approach may be beneficial for difficult clinical scenarios. In particular, the PTP position may facilitate lateral corpectomy for certain lumbar pathologies where a circumferential approach is necessary. Case presentation: A 23-year-old woman presented to the ED with wound breakdown four months after a T10-L2 posterior spinal fusion (PSF) was performed following a motor vehicle accident. Imaging studies revealed distal hardware failure and compromise of her distal vertebral body. A lateral corpectomy and interbody fusion was performed. Discussion: We report a case of lateral lumbar corpectomy via a novel PTP approach for a patient with a significant amount of kyphosis, wound breakdown, and hardware failure. We include a review of the current literature on prone transpsoas lateral lumbar interbody fusion. Initial reports do not suggest inferiority compared to other approaches. However, given its novelty, further investigation is needed.

Retrograde ejaculation after anterior lumbar interbody fusion - Transperitoneal versus retroperitoneal exposure

Article

May 2003

Study Design. In this multicenter, prospective, 2-year study, 146 male patients underwent a single-level anterior lumbar interbody fusion with a tapered threaded titanium fusion device. All the patients were advised before surgery of the risk for retrograde ejaculation. After surgery, any case of retrograde ejaculation was recorded as an adverse event, and the patient was observed up for the remainder of the study. Objective. To determine the incidence of retrograde ejaculation in male patients treated for single-level degenerative lumbar disc disease at L4-L5 or L5-S1 with a stand-alone anterior interbody fusion using tapered, threaded titanium fusion cages. Summary of Background Data. The incidence of retrograde ejaculation in men after anterior lumbosacral spinal surgery has been reported to range from 0.42% to 5.9%. Various risk factors that increase the chance of retrograde ejaculation have been proposed. Methods. In this prospective study, 146 male patients underwent an open surgical exposure of the lumbosacral junction and a single-level interbody fusion at either L4-L5 or L5-S1. Assessment of a patient's clinical outcome was based on written questionnaires at 6 weeks and then 3, 6, 12, and 24 months after surgery. Patients were questioned about adverse events at each of these assessments, and any case of retrograde ejaculation was recorded and followed. Results. Retrograde ejaculation developed in 6 of the 146 men after open anterior lumbar interbody fusion surgery. Two cases (1.7%; 2/116) involved patients who underwent a retroperitoneal surgical exposure. Four cases (13.3%; 4/30) involved patients who had a transperitoneal surgical exposure. This difference is statistically significant according to Fisher's exact test (P = 0.017). At 12 months after surgery, 2 patients had resolution of their symptoms: 1 in the retroperitoneal approach group and 1 in the transperitoneal group. At the final 2-year follow-up, no changes in symptoms were reported. One patient in the retroperitoneal approach group (0.86%) and three patients in the transperitoneal group (10%) reported permanent retrograde ejaculation (P = 0.027). Conclusions. A transperitoneal approach to the lumbar spine at L4-L5 and L5-S1 has a 10 times greater chance of causing retrograde ejaculation in men than a retroperitoneal approach.

The unilateral transforaminal approach for posterior lumbar interbody fusion

Article

Jan 1998

A carbon fiber implant to aid lumbar interbody fusion. Two-year clinical results in the first 26 patients

Article

Oct 1993

The success of posterior lumbar interbody fusion (PLIF) has been limited by mechanical and biologic deficiencies of the donor bone. The authors have designed a carbon fiber-reinforced polymer implant that separates the mechanical and biologic functions of PLIF. The cagelike implant provides an actual device designed to meet the mechanical requirements of PLIF and replaces the donor bone with autologous bone, the best possible bone for healing. The authors report 2-year follow-up results for their first 26 consecutive patients, 18 of whom were postsurgical failed backs with a total of 37 previous surgeries. At 2 years, 28 of 28 PLIF cage fusion levels and 6 of 11 (54.5%) allograft levels exhibited radiographic fusion, a statistically significant difference at P = 0.0002. Clinical results were excellent in 11/26, good in 10/26, fair in 3/26, and poor in 2/26. Fair and poor results were attributable to objective identifiable problems unrelated to the carbon cage. The carbon implant achieved successful fusion in 6/6 (100%) of followed patients treated for a failed ETO allograft interbody fusion. A prospective controlled multi-centered study is being initiated.

Posterior Lumbar Interbody Fusion with Specialized Instruments

Article

Mar 1985
CLIN ORTHOP RELAT R

GABRIEL W. C. MA

Posterior lumbar interbody fusion (PLIF) has been performed in 100 individuals by use of specialized surgical instruments and allogeneic preserved bone grafts from 1979 to March 1982, after the advantages of performing PLIF in 342 individuals from 1965 to 1978 were noted. No deaths occurred, nor any infections or thrombophlebitis postoperation. Eleven (11%) reoperations were required: six for proven pseudarthrosis, three for gradual bone graft extrusion (of six extrusions total), one for bone graft fracture (with manifestations of nerve root compression), and one for hematoma. Operative results were excellent in 35%, good in 39%, fair in 17%, and poor in 9%. Specialized surgical instruments used for the operation included mortising chisels with cannulated reamers, right-angled curettes, and depth-limited impactors. PLIF is technically demanding; however, it establishes a mortise-graft interbody fusion to stabilize and restore the spinal architecture. (C) Lippincott-Raven Publishers.

Minimally invasive anterolateral approaches for the treatment of back pain and adult degenerative deformity

Article

Sep 2008
NEUROSURGERY

Minimally invasive and interbody and instrumented fusion techniques are increasingly being used for the treatment of adult degenerative disc disease, stenosis, and deformity of the lumbar spine. Advocates of minimal access spinal approaches list certain advantages over open procedures, including decreased postoperative pain and narcotic requirements, shorter hospital stays, less blood loss, and smaller incisions. The minimally invasive anterolateral approach allows access to the lumbar spine through the retroperitoneal space. We report on the short-term clinical and radiographic outcomes in four patients with mid to high lumbar coronal deformities treated at our institution with the anterolateral transpsoas minimally invasive approach. The primary presentation of these patients was back and leg pain. All patients showed improvement in their preoperative symptoms and solid arthrodesis at 6 months. Independent nonbiased patient pain analysis was also performed. Mean follow-up was 10 months (standard deviation, 1.4 mo), and mean hospital stay was 3.5 days (standard deviation, 1.9 d). One patient had additional posterior segmental instrumentation placed. Mean Cobb angles in the coronal plane were 28.5 degrees preoperatively and 18.3 degrees postoperatively (P < 0.05). We also present a historical perspective on retroperitoneal spine surgery, a regional anatomic description of the lumbosacral plexus and surrounding structures, and a description of the surgical technique as related to treatment of lumbar deformity.

Minimally Invasive Multilevel Percutaneous Correction and Fusion for Adult Lumbar Degenerative Scoliosis

Article

Nov 2008

Prospective evaluation of 12 patients undergoing surgery for lumbar degenerative scoliosis. To assess the feasibility of minimally invasive spine surgery (MIS) techniques in the correction of lumbar degenerative deformity. Patient age, comorbidities, and blood loss may be limiting factors when considering surgical correction of lumbar degenerative scoliosis. MIS may allow for significantly less blood loss and tissue disruption than open surgery. Twelve patients underwent circumferential fusion. The age range of these patients was 50 to 85 years (mean of 72.8 y). Of the 12 patients, 7 were men and 5 were women. All patients underwent direct lateral transpsoas approach for discectomy and fusion with polyetheretherketone cage and rh-BMP2. All fusions to the sacrum included L5-S1 fusion with the Trans1 Axial Lumbar Interbody Fusion technique. Posteriorly, multilevel percutaneous screws were inserted using the CD Horizon Longitude system. Radiographs, visual analog scores (VAS), and treatment intensity scores (TIS) were assessed preoperatively and at last postoperative visit. Operative times and estimated blood loss were recorded. Mean number of segments operated on was 3.64 (range: 2 to 8 segments). Mean blood loss for anterior procedures (transpsoas discectomy/fusion and in some cases L5-S1 interbody fusion) was 163.89 mL (SD 105.41) and for posterior percutaneous pedicle screw fixation (and in some cases L5-S1 interbody fusion) was 93.33 mL (SD 101.43). Mean surgical time for anterior procedures was 4.01 hours (SD 1.88) and for posterior procedures was 3.99 hours (SD 1.19). Mean Cobb angle preoperatively was 18.93 degrees (SD 10.48) and postoperatively was 6.19 degrees (SD 7.20). Mean preoperative VAS score was 7.1; mean preoperative TIS score was 56.0. At mean follow-up of 75.5 days, mean VAS was 4.8; TIS was 28.0. A combination of 3 MIS techniques allows for correction of lumbar degenerative scoliosis. Multisegment correction can be performed with less blood loss and morbidity than for open correction.

Patient Outcomes After Lumbar Spinal Fusions

Article

Sep 1992

To determine success and complication rates for lumbar spinal fusion surgery, predictors of good outcomes, and whether fusion improves success rates of laminectomy for specific low back disorders. English-language journal articles published from 1966 through April 1991, identified through MEDLINE searching (spinal fusion plus limiting terms), bibliography review, and expert consultation. Articles were selected only if they reported at least 1 year of follow-up data enabling the classification of clinical outcomes as satisfactory or unsatisfactory for at least 30 patients. Two reviewers independently extracted data on patient characteristics, surgical methods, patient outcomes, and quality of study methods. Of 47 articles, there were no randomized trials. Four nonrandomized studies compared surgery with and without fusion for herniated disks; three found no advantage for fusion. On average, 68% of patients had a satisfactory outcome after fusion, but the range was wide (16% to 95%), and the satisfactory outcome rate was lower in prospective than in retrospective studies. The most frequently reported complications were pseudarthrosis (14%) and chronic pain at the bone graft donor site (9%). Clinical outcomes did not differ by diagnosis or fusion technique, but were worse in studies with a greater number of previously operated patients. For several low back disorders no advantage has been demonstrated for fusion over surgery without fusion, and complications of fusions are common. Randomized controlled trials are needed to compare fusion, surgery without fusion, and nonsurgical treatments in rigorously defined patient groups.

Experimental Evaluation of Seven Different Spinal Fracture Internal Fixation Devices Using Nonfailure Stability Testing

Article

Sep 1991

Fracture site immobilization capabilities of seven internal spine fixation systems were experimentally evaluated: Harrington double distraction (plain, supplemented with Edwards sleeves, supplemented with sublaminar wires), Luque rectangle, Kaneda device, transfixed Kaneda device, and Steffee plates. Stability evaluation involved comparing the three-dimensional motion that occurred across an experimentally created L1 slice fracture, and the load resistance of the implants when subjected to axial, flexion, extension, lateral bending, and torsional loads. Each implant was tested on 15 different vertebral segments from 200-250-lb calves. All implants load-shared with the fractured vertebral column to varying degrees. All except the Steffee plate system showed an obvious biomechanical weakness in one or more load modes. The unstable 4R-4bar mechanism configuration of bilevel spinal implants was identified. Mechanism configurations allow free movement with little or no resistance to the applied load until load sharing by the spinal column stops the collapse and resists the applied load.

The Role of Anterior Lumbar Fusion for Internal Disc Disruption

Article

Jun 1988

Internal disc disruption is a syndrome of traumatically induced low-back pain arising from the intervertebral disc. The diagnosis is confirmed by abnormal discography with concordant pain reproduction at the affected level or levels. Thirty-four patients with internal disc disruption at one level were followed for an average of 29 months. Eighteen (53%) underwent anterior lumbar fusion at the L4-5 disc, 11 (32%) at the L5-S1 disc and the remainder at the L3-4 or L2-3 disc. Bank bone was used in all but seven patients for interbody fusion. Treatment was judged a success by the patient returning to work or normal activities and requiring either no medications or an antiinflammatory drug only. By the above criteria 25 patients (74%) had successful outcome of treatment. The average time to return to work or normal activities was 6.1 months. The overall union rate was 73% with an average time to union of approximately 12 months. Complications consisted of graft extrusion requiring revision and retrograde ejaculation. These occurred in one patient and were the only complications in the series. We concluded that disc excision and anterior interbody fusion is an effective treatment for internal disc disruption.

Posterior Lumbar Interbody Fusion and Plates

Article

Mar 1988

Posterior lumbar interbody fusion (PLIF) is accepted by many authors as the surgical treatment for herniated discs, degenerative disc conditions, and Grades I and II spondylolistheses. PLIF is now used in conjunction with newly developed segmental spine plates by using transpedicular screw fixation to enhance the osteosynthesis and success rate of interbody fusion. To date, 104 fusions have been performed in 67 patients with no dislocations of any interbody grafts and no indication of absorption, pseudoarthrosis, or infections.

Extreme lateral interbody fusion - XLIF

Abstract and Figures

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