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Basic Knee Arthroscopy Part 2: Surface Anatomy and Portal Placement

November 2013
Arthroscopy Techniques 2(4)

November 2013
2(4)

DOI:10.1016/j.eats.2013.07.013

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CC BY-NC-ND 4.0

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Knee arthroscopy is an important diagnostic and therapeutic tool in the management of disorders of the knee. In a series of 4 articles, the basics of knee arthroscopy are reviewed. In this article (part 2), surface anatomy and the anterolateral and anteromedial portals are reviewed. Accurate portal placement is critical to both diagnostic and operative arthroscopy. Mastery of the surface anatomy allows accurate and reproducible portal placement.

Surface anatomy markings for a left knee: (A) patella, (B) patellar tendon, (C) tibial tubercle, (D) anteromedial portal, (E) anterolateral portal, (F) fibular head, and (G) superior medial portal (optional portal for fluid outflow).

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Arthroscopic view, left knee, of medial compartment taken from the anterolateral portal. A spinal needle is used to determine the placement of the anteromedial portal. The needle should enter the knee just superior to the medial meniscus and inferior enough to reach the posterior horn of the medial meniscus.

…

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Basic Knee Arthroscopy Part 2: Surface Anatomy

and Portal Placement

Benjamin D. Ward, M.D., and James H. Lubowitz, M.D.

Abstract: Knee arthroscopy is an important diagnostic and therapeutic tool in the management of disorders of the knee.

In a series of 4 articles, the basics of knee arthroscopy are reviewed. In this article (part 2), surface anatomy and the

anterolateral and anteromedial portals are reviewed. Accurate portal placement is critical to both diagnostic and operative

arthroscopy. Mastery of the surface anatomy allows accurate and reproducible portal placement.

Knee arthroscopy is the most commonly performed

orthopaedic procedure. Indications include diag-

nostic arthroscopy, meniscectomy, loose body removal,

chondroplasty, microfracture, irrigation and debride-

ment, and ligament reconstruction. In this series of arti-

cles, we present a comprehensive review of the complete

surgical technique for basic knee arthroscopy.

1,2

Knee surface anatomy and portal placement are

reviewed in this article and Video 1. Accurate portal

placement is critical to both diagnostic and operative

arthroscopy. Mastery of the surface anatomy allows

accurate and reproducible portal placement. Proper

placement of the anterolateral portal just superior to

the lateral meniscus and just lateral to the patellar

tendon allows optimal visualization of the compart-

ments of the knee and proper access for the operative

instruments. Proper placement of the anteromedial

portal just superior to the medial meniscus but inferior

enough for instruments to reach the posterior horn of

the meniscus is also critical.

Surgical Technique

This article will review the relevant surface anatomy

as well as placement of the anterolateral and ante-

romedial portals (Fig 1). Beginning arthroscopists will

ﬁnd it beneﬁcial to mark out the surface anatomy as

a reference for portal placement. The palpable borders

of the patella, tibial tubercle, and patellar tendon, the

medial and lateral tibial joint line, and the head of the

ﬁbula are marked on the skin. Typically, the lateral joint

line is slightly more superior than the medial joint line.

The marks will give a reference for placement of the

arthroscopic portals. The anterolateral and antero-

medial portals can be vertical or horizontal. Horizontal

portals are more cosmetic, but if they are placed too

high or too low, they may be difﬁcult to correct, so the

beginning arthroscopist may prefer a vertical portal.

The superomedial portal is an optional portal typically

used for ﬂuid outﬂow. The anterolateral portal is placed

1 cm above the joint line and just next to the patellar

tendon in a palpable soft spot. The anteromedial portal

is placed 1 cm above the joint line and 1 cm medial to

the patellar tendon, also in a palpable soft spot. The

placement of the anteromedial portal can be conﬁrmed

with a spinal needle using the arthroscope.

After marking, the portals are typically injected with

a local anesthetic. A No. 15 or 11 blade with the blade

facing away from the patellar tendon is used to make

a 4- to 5-mm portal. The skin and the joint capsule are

incised, with care taken not to damage the ligaments or

cartilage and to stay above the meniscus. The arthros-

copic cannula with a blunt obturator is then brought

into the ﬁeld and held with the index ﬁnger along the

cannula. The cannula is inserted into the anterolateral

portal at an angle parallel to the tibial plateau and

directed between the condyles. The cannula is then

pushed into the intercondylar notch. This motion is

From the Taos Orthopaedic Institute, Taos, New Mexico, U.S.A.

The authors report the following potential conﬂict of interest or source of

funding: B.D.W. receives support from Arthrex Fellows Forum Travel and

Hotel; J.H.L. receives support from SNE, Arthrex, Ivivi, AANA, law ﬁrms not

related to the orthopaedic industry (i.e., medical malpractice defense, ski

industry defense), Breg, Donjoy, Smith & Nephew, MTF, DCI, patents pending

with Arthrex not related to manuscript, Taos Orthopaedic Institute, Taos

Center for Sportsmedicine and Rehabilitation, and Taos MRI.

Received June 29, 2013; accepted July 25, 2013.

Address correspondence to James H. Lubowitz, M.D., Taos Orthopaedic

Institute, 1219-A Gusdorf Rd, Taos, NM 87571, U.S.A. E-mail: jlubowitz@

kitcarson.net

Ó2013 by the Arthroscopy Association of North America

2212-6287/13439/$36.00

http://dx.doi.org/10.1016/j.eats.2013.07.013

Arthroscopy Techniques, Vol 2, No 4 (November), 2013: pp e501-e502 e501

repeated a few times to ensure that the cannula moves

freely through the portal and fat pad. Then, the cannula

is pulled back just enough to be outside of the inter-

condylar notch, the knee is straightened into full

extension, and the cannula is advanced under the

patella into the suprapatellar pouch. The obturator is

removed, and the arthroscopic camera is locked into the

cannula. The ﬂuid ﬂow is then started, and the

arthroscopic procedure is begun. Basic diagnostic and

operative arthroscopy will be discussed in the subse-

quent articles.

The anteromedial portal is the main working or

instrumentation portal. The placement of this portal is

critical for effectively reaching the various intra-articular

structures with the arthroscopic instruments. It is rec-

ommended to create this portal under direct vision using

the arthroscope. A spinal needle is inserted into the

medial compartment through the previously marked

portal. The needle is held toward the tip so as not to

over-penetrate and damage the cartilage. The needle is

inserted just above the meniscus. Under direct vision,

the needle is advanced to touch the posterior horn of the

medial meniscus (Fig 2). If the entry angle is too high or

too vertical, the femur will prevent access to the poste-

rior structures. After an optimal position is found, the

needle is removed and the No. 15 or 11 blade is used

again to cut the skin approximately 5 mm. The knife

is then advanced, and an inline capsulotomy is per-

formed. Fluid escape from the portal is seen when an

adequate capsulotomy has been performed. At this

point, a beginning arthroscopist and even some ad-

vanced arthroscopists will put a cannula into the portal.

A hemostat can also be used to spread the portal to make

the passage of instruments easier.

Discussion

Knee arthroscopy is a valuable diagnostic and thera-

peutic procedure for the treatment of various knee

disorders. Precise placement of the anterolateral and

anteromedial portals allows for full access to the

compartments of the knee. A key point to remember in

marking the surface anatomy is that the lateral tibial

plateau is usually slightly superior to the medial tibial

plateau. Marking the surface anatomy will facilitate

accurate placement of the portals. The anterolateral

portal should be placed just superior to the lateral

meniscus and close to the patellar tendon. The ante-

romedial portal is the main working portal and there-

fore should be placed under direct visualization to

ensure that the instruments will be able to reach the

posterior meniscus and other structures.

References

1. Phillips BB. Arthroscopy of the lower extremity. In:

Canale ST, Beaty JH, editors. Campbell’s operative orthopae-

dics. Ed 11. Philadelphia: Mosby Elsevier; 2008:2811-2893.

2. Aviles SA, Allen CR. Knee arthroscopy: The basics. In:

Wiesel SW, editor. Operative techniques in orthopaedic surgery.

Philadelphia: Lippincott Williams & Wilkins; 2011:248-256.

Fig 1. Surface anatomy markings for a left knee: (A) patella,

(B) patellar tendon, (C) tibial tubercle, (D) anteromedial

portal, (E) anterolateral portal, (F) ﬁbular head, and (G)

superior medial portal (optional portal for ﬂuid outﬂow).

Fig 2. Arthroscopic view, left knee, of medial compartment

taken from the anterolateral portal. A spinal needle is used to

determine the placement of the anteromedial portal. The

needle should enter the knee just superior to the medial

meniscus and inferior enough to reach the posterior horn of

the medial meniscus.

e502 B. D. WARD AND J. H. LUBOWITZ

Is posterior knee arthroscopy using posterior portals necessary for orthopedic surgeons? The latest evidence on applications and techniques

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Various uses of posterior knee arthroscopy have been shown, including all-inside repair of posterior meniscal lesions, posterior cruciate ligament (PCL) reconstruction or PCL avulsion fixation, extensile posterior knee synovectomy for pigmented villonodular synovitis or synovial chondromatosis, posterior capsular release in the setting of knee flexion contractures, and loose bodies removal. Posterior arthroscopy provides direct access to the posterior meniscal borders for adequate abrasion and fibrous tissue removal. This direct view of the knee posterior structures enables the surgeon to create a stronger biomechanical repair using vertical mattress sutures. During PCL reconstruction, posterior arthroscopy gives the surgeon proper double access to the tibial insertion site, which can result in less acute curve angles and the creation of a more anatomic tibial tunnel. Moreover, it gives the best opportunity to preserve the PCL remnant. Arthroscopic PCL avulsion fixation is more time-consuming with a larger cost burden compared to open approaches, but in the case of other concomitant intra-articular injuries, it may lead to a better chance of a return to pre-injury activities. The high learning curve and overcaution of neuromuscular injury have discouraged surgeons from practicing posterior knee arthroscopy using posterior portals. Evidence for using posterior portals by experienced surgeons suggests fewer complications. The evidence suggests toward learning posterior knee arthroscopy, and this technique must be part of the education about arthroscopy. In today's professional sports world, where the quick and complete return of athletes to their professional activities is irreplaceable, the use of posterior knee arthroscopy is necessary.

Effect of Tunnel Drilling Portal on Femoral Tunnel Entry Aperture’s Location in Arthroscopic Anterior Cruciate Ligament Reconstruction

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Introduction Transportal techniques for femoral tunnel drilling have the advantage of anatomical anterior cruciate ligament reconstruction, which was earlier difficult to achieve through transtibial femoral tunnels. However, the medial arthroscopic portal used for femoral tunnel drilling in single-bundle anterior cruciate ligament reconstruction (ACLR) has not been uniformly placed in different studies. Therefore, we performed a computed tomography-based analysis to compare the femoral tunnel entry aperture of the ACLR cases that used the standard AM portal and those using a far medial portal for femoral tunnel drilling. Methods We retrospectively reviewed computed tomography images of patients who underwent isolated single-bundle ACLR in our institute with either standard anteromedial portal or the far medial portal used for the femoral tunnel drilling. The femoral tunnel aperture's depth and height, measured using the quadrant method, were compared between the two portal methods. Results A total of forty-two case records were reviewed, sixteen belonging to standard anteromedial portal technique and twenty-six belonging to far medial portal technique. The tunnels created through the far AM portal were significantly shallower (more anterior) and inferior than the standard AM portal-created femoral tunnels. Conclusion The choice of drilling portals can influence transportal femoral tunnel drilling. A tendency towards anterior and inferior positioning of the femoral tunnel entry aperture has been observed when a far medial arthroscopic portal is used for femoral tunnel drilling. Therefore, care must be taken to ensure that the drilling guide pin position does not change when the reamer is passed over it.

Greater Patient Satisfaction With Use of Nonabsorbable Sutures Compared to Absorbable Sutures for Skin Closure Following Knee Arthroscopy: A Randomized Controlled Trial

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Arthroscopic-assisted robotic bi-unicompartmental knee arthroplasty: a pilot cadaveric study

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ARCH ORTHOP TRAUM SU

Introduction Although bicondylar arthroplasty showed great functional results, it encounters some difficulties to be performed routinely. On the other hand, arthroscopic techniques tend to replace open surgical techniques in sports medicine but strive to be developed in the field of arthroplasty. This study aimed to assess the feasibility of a micro-invasive bi-compartmental knee arthroplasty using both arthroscopic and robotic technologies (A-BiUKA). Materials and Methods The study was conducted on complete fresh-frozen and embalmed cadaveric specimens. The main criterion of judgment was the successful positioning of trial implants through a minimal quad-sparing approach. Arthroscopy was used for bone-morphing and burring, supported by an image-free robotic system. Secondary criteria of judgment were axial deviation (measured using the navigation system), operating time, and incision length. Results Ten A-BiUKA were performed. Implantation was successful in all cases. The mean preoperative frontal deviation was 179.8° ± 3.2 [175: 185], the mean postoperative frontal deviation was 178.5° ± 2.2 [175: 182], without any outliers. The mean correction was 1.7° ± 1.6 [0: 5]. Once the eight first A-UKA were performed, constituting the learning curve, the mean operative time for the remaining twelves surgeries was 90 min ± 6. The mean skin incision length was 3.35 cm ± 0.13 [3: 4]. Conclusion Associated arthroscopic and robotic technologies allows to perform Bi-UKA procedure using a quad sparing mini-invasive approach. Clinical prospective studies have to confirm the feasibility and the clinical outcomes of this surgery.

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Revision anterior cruciate ligament (ACL) reconstruction is a technically demanding procedure, and the surgeon should be prepared to address bone tunnel osteolysis, concurrent meniscal, ligamentous, or cartilage lesions, and limb malalignment. ACL revision can typically be done in one procedure, but it may need to be staged if there is poor previous tunnel positioning or excessive tunnel osteolysis. Bone grafting of the tunnels can be accomplished in several ways, including autograft, allograft, or bone substitutes. Currently, no consensus is available regarding the optimal choice of bone graft material for bone tunnel augmentation in revision ACL reconstruction. Bone graft substitute for tunnel augmentation has been showed to have good histologic, radiographic, and intraoperative integration, comparable to that of autologous bone. In this Technical Note, the technical details of arthroscopic treatment of attenuated anterior cruciate ligament graft with enlarged bone tunnels are described. The tunnels are debrided arthroscopically and filled up with PRO-DENSE injectable regenerative graft.

Güncel Ortopedi ve Travmatoloji Çalışmaları VI Menisküs ve Diz Çevresi Bağ Yaralanmalarında Güncel Yaklaşımlar

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Dizin Artroskopik Anatomisi ve Portaller Soner KOÇAK Abdülkadir YALÇINKAYA Menisküs Yırtıklarına Yaklaşım Nihat Demirhan DEMİRKIRAN Ramadan ÖZMANEVRA Süleyman Kaan ÖNER Menisküs Transplantasyonu ve Skafoldlar Erdem ATEŞ Artroskopik Kıkırdak Tedavileri- Mozaikplasti Kemal ŞİBAR Primer Ön Çapraz Bağ Rekonstrüksiyonu Günbay Noyan DİRLİK Arka Çapraz Bağ Rekonstrüksiyonu Fatih GÜNAYDIN Medial Kollateral Ligament ve Posteromedial Köşe Yaralanmalar Volkan ÖZEL Diz Artroskopisi Komplikasyonları Mehmet Yiğit GÖKMEN Revizyon Ön Çapraz Bağ Rekonstrüksiyonu Mustafa Çağlar KIR Pediatrik Ön Çapraz Bağ Rekonstrüksiyonu Öner KILINÇ Sert Dizde Artroskopik Gevşetme İdris DEMİRTAŞ

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Purpose To investigate the safety and accessibility of direct posterior medial and lateral portals into the knee. Methods This study was a controlled laboratory study that comprised a sample of 95 formalin-embalmed cadaveric knees and 9 fresh-frozen knees. Cannulas were inserted into the knees, 16 mm from the vertical plane between the medial epicondyle of the femur and the medial condyle of the tibia, and 8 (females) and 14 mm (males) from the vertical plane connecting the lateral femoral epicondyle and lateral tibial condyle. Landmarks were identified in full extension, and cannula insertion was completed with the formalin-embalmed knees in full extension and the fresh-frozen knees in 90 degrees of flexion. The posterior aspects of the knees were dissected from superficial to deep to assess potential damage caused by the cannula insertion. Results The incidence of neurovascular damage was 9.6% (n = 10): 0.96% for the medial cannula and 8.7% for the lateral cannula. The medial cannula damaged 1 small saphenous vein (SSV). The lateral cannula damaged 1 SSV, 7 common fibular nerves (CFNs), and both the CFN and lateral cutaneous sural nerve in 1 specimen. All incidences of damage occurred in formalin-embalmed knees. The posterior horns of the menisci were accessible in all specimens. Conclusions A direct posterior portal into the knee with reference to the medial bony landmarks of the knee proved safe in 99% of the cadaveric sample and allowed access to the posterior horn of the medial meniscus. A direct posterior portal with reference to the lateral bony landmarks demonstrated a higher risk of neurovascular damage in the embalmed sample but no damage in the fresh-frozen sample. Given the severe consequences of common fibular nerve injury, recommending this approach at this stage is not advisable. Clinical Relevance Direct posterior arthroscopy portals are understudied but may allow safe visualization of the posterior knee compartments and may also assist to manage repair of ramp lesions and posterior meniscus pathology.

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Diagnostic Knee Arthroscopy and Arthroscopic Anatomy

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Arthroscopy is a powerful tool for the diagnosis and treatment of intraarticular pathology in the knee. In comparison to an open procedure or an arthrotomy, knee arthroscopy is considered to have the advantage of lower morbidity due to being a less invasive technique. Arthroscopy is an important skill for every orthopedic surgeon. Knowledge of anatomical landmarks is paramount to assist surgeons with proper and safe portal placement and to avoid neurovascular structures. Standard portals include anterolateral and anteromedial portals, with other accessory portals when indicated. Diagnostic arthroscopy is a safe procedure and should be completed in a thorough, methodical way every time so as not to miss pathology.KeywordsKnee arthroscopyPortals

Knee arthroscopy: The basics

Article

Mar 2012

Arthroscopy of the lower extremity

Article

Jan 2008

B.B. Phillips

Knee arthroscopy: The basics Operative techniques in orthopaedic surgery

248-256

Aviles Sa
Allen
Cr

Aviles SA, Allen CR. Knee arthroscopy: The basics. In: Wiesel SW, editor. Operative techniques in orthopaedic surgery. Philadelphia: Lippincott Williams & Wilkins; 2011:248-256.

Operative techniques in orthopaedic surgery

Jan 2011
248-256

S A Aviles
C R Allen

Aviles SA, Allen CR. Knee arthroscopy: The basics. In: Wiesel SW, editor. Operative techniques in orthopaedic surgery. Philadelphia: Lippincott Williams & Wilkins; 2011:248-256.