Table 3 - uploaded by Jean-Luc Clément
Content may be subject to copyright.
Source publication
Recent publications confirm that moderate correction of thoracic hypokyphosis can be achieved by posterior instrumentation with hooks or pedicle screws. Twenty-four prospective and consecutive thoracic adolescent scoliosis patients with hypokyphosis (<20°) were operated on by posterior spinal fusion (PSF) with a specific method of reduction: Simult...
Context in source publication
Context 1
... instru- mented minor curves translation decreased from 24 mm preoperatively to 10 mm at last follow-up. Table 3 illustrates sagittal plane radiographic results for thoracic kyphosis and lumbar lordosis. The average thoracic kyphosis significantly increased from 9° preoper- atively to 30° at immediate postoperative follow-up, and to ...
Similar publications
Background
Open reduction and internal fixation through the Kocher–Langenbeck approach is the treatment of choice for selected acetabular fracture patterns. Patient positioning (lateral vs prone) can affect the outcome and post-operative complications.
Methods
A retrospective cohort of seventy-three adult patients’ with acetabular fractures treate...
The development of post-traumatic osteoarthrosis after tibial plateau fracture (TPF) is multifactorial and can only be partially influenced by surgical treatment. There is no standardized method for assessing pre- and postoperative knee joint laxity. Data on the incidence of postoperative laxity after TPF are limited. The purpose of this study was...
Retrospective cohort study.
To evaluate efficacy and relevant problems of in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation in expansive open-door cervical laminoplasty in order to improve surgical treatment effect.
Expansive open-door cervical laminoplasty has been wid...
The evaluation and treatment of aggressive bone tumors continue to be diagnostic and therapeutic challenges for orthopaedic surgeons. Despite compelling data regarding the hazards of biopsy, incomplete preoperative evaluation, inappropriate biopsy techniques, and premature surgical interventions continue to compromise optimal treatment of primary b...
Background
Management of an infected nonunion of the long bones is quite difficult and challenging. A staged procedure comprising of radical debridement followed by definitive internal fixation is favored. However, no standard treatment has been established for determining the appropriate waiting period between the initial debridement and the defin...
Citations
... the bands were partially tensioned. The corrective maneuver was done via ST2R as described by Clement et al. [16]. Once the rods were positioned in the correct alignment, the concave LigaPASS connectors (Medicrea, USA) were tightened to the concave rod. ...
Purpose
To determine if the planned sagittal profile for thoracic kyphosis (TK) restoration was achieved after adolescent idiopathic scoliosis (AIS) surgery using a novel hybrid construct with apical double bands and precontoured patient-specific rods (PSR) made according to the detailed surgical plan for the desired sagittal plane.
Methods
AIS patients with a Lenke type 1–4 primary right thoracic curve who underwent corrective surgery by a single surgeon and had minimum 24-month follow-up were analyzed retrospectively from a prospective database. All patients underwent simultaneous translation on two rods with apical double bands and PSR. Clinical outcomes in terms of sagittal 2D TK (T4–T12), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), PI–LL mismatch, rod angle, and rod deflection were compared between preoperative, planned, and 24-month data, while 3D apical rotation, 3D TK (T5–T12), sagittal thoracolumbar angle, degree of curvature at L1–L4 and L4–S1, proximal junctional angle, and distal junctional angle were compared at baseline and at 6 and 24 months postoperatively. SRS-22 questionnaire scores were obtained at baseline and 24 months postoperatively.
Results
Forty-eight patients were included. Study patients had a median coronal thoracic curve of 62.7° preoperatively and 22.4° at 24-month follow-up (p < 0.001). Median TK gain was 6.5° for the entire cohort (n = 48) and 19.1° in the Lenke type 1 and 2 hypokyphotic subgroup (n = 14). Both groups had no significant changes between planned and 24-month TK (p = 0.068 and p = 0.943, respectively), rod angle (p = 0.776 and p = 0.548, respectively), or rod deflection (p = 0.661 and p = 0.850, respectively). For the overall study cohort, median LL gain was 7.0° (p < 0.001), 3D apical derotation was 10.7° (p < 0.001), and change in 3D TK was 36° (p < 0.001). No instance of proximal junctional kyphosis was observed. SRS-22 scores for pain, self-image, and satisfaction differed significantly between the preoperative and 24-month follow-up time-points.
Conclusions
With sagittal plane planning, desired TK, improved reciprocal changes in LL, and minimal changes in rod shape can be achieved in patients with AIS.
... Revision surgery: Three studies using Ti rods reported revisions [53, 74,82]. The overall pooled proportion for revision was 6% (95% CI 0.0-12.0%). ...
... for CoCr rods. Only one study using stainless steel and another study using Ti rods reported reoperation rates [82]. Thus, the test for subgroup difference could not be performed due to the small number of studies. ...
... Surgical outcomes Kyphosis angle correction: No studies directly compared the impact of rod diameter on postoperative kyphosis angle. Three studies utilized 6 mm posterior rods for AIS surgery and reported corresponding change in the kyphosis angle [21,22,82]. The pooled MD in change in kyphosis angle with 6 mm rods was 13.69° (95% CI: 8.54°-18.84°). ...
Purpose
To assess surgical and safety outcomes associated with different rod materials and diameters in adolescent idiopathic scoliosis (AIS) surgery.
Methods
A systematic literature review and meta-analysis evaluated the surgical management of AIS patients using pedicle screw fixation systems (i.e., posterior rods and pedicle screws) with rods of different materials and sizes. Postoperative surgical outcomes (e.g., kyphosis and coronal correction) and complications (i.e., hyper/hypo-lumbar lordosis, proximal junctional kyphosis, revisions, reoperations, and infections) were assessed. Random-effects models (REMs) pooled data for outcomes reported in ≥ 2 studies.
Results
Among 75 studies evaluating AIS surgery using pedicle screw fixation systems, 46 described rod materials and/or diameters. Two studies directly comparing titanium (Ti) and cobalt–chromium (CoCr) rods found that CoCr rods provided significantly better postoperative kyphosis angle correction vs. Ti rods during a shorter follow-up (0–3 months, MD = − 2.98°, 95% CI − 5.79 to − 0.17°, p = 0.04), and longer follow-up (≥ 24 months, MD = − 3.99°, 95% CI − 6.98 to − 1.00, p = 0.009). Surgical infection varied from 2% (95% CI 1.0–3.0%) for 5.5 mm rods to 4% (95% CI 2.0–7.0%) for 6 mm rods. Reoperation rates were lower with 5.5 mm rods 1% (95% CI 0.0–3.0%) vs. 6 mm rods [6% (95% CI 2.0–9.0%); p = 0.04]. Differences in coronal angle, lumbar lordosis, proximal junctional kyphosis, revisions, and infections did not differ significantly ( p > 0.05) among rods of different materials or diameters.
Conclusion
For AIS, CoCr rods provided better correction of thoracic kyphosis compared to Ti rods. Patients with 5.5 mm rods had fewer reoperations vs. 6.0 and 6.35 mm diameter rods.
Level of evidence
III.
... Surgeries were performed by the senior surgeon (JLC) using hybrid high-density construct with mainly polyaxial pedicle screws and self-stabilizing polyaxial claws at upper vertebra (T2, T3 and T4 in 15, 29 and 48 cases, respectively). The reduction technique as previously described [20] was a posteromedial, simultaneous translation on the 2 rods, which were bent to the target sagittal profile based on surgeon expertise. ...
PurposeThe modification of cervical lordosis (CL) after adolescent idiopathic scoliosis (AIS) surgery is influenced by the correction of thoracic hypokyphosis. The quantification of the increase of CL as a function of the increase of thoracic kyphosis (TK) has never been calculated.MethodsA total of 92 consecutive AIS patients who underwent a posterior thoracic selective fusion, corrected by simultaneous translation on 2 rods technique, with minimum 24-month follow-up, were analyzed from a prospective database. We evaluated global sagittal kyphosis and lordosis. CL was divided by the horizontal line in proximal (PCL) and distal cervical lordosis (DCL), likewise TK in proximal (PTK) and distal TK (DTK), and lumbar lordosis (LL) in proximal (PLL) and distal LL (DLL).ResultsThe mean TK gain was 16°, 14° and 28° in the whole cohort, normokyphosis group and hypokyphosis group, respectively. The mean DCL gain was, respectively, 9°, 7° and 20° and the mean CL gain 8°, 5° and 21°. There was a strong correlation between TK gain and CL gain (coefficient = 0.86) and between TK gain and DCL gain (coefficient = 0.74). The regression equation was defined as DCLgain = − 3 + 0.75 × TKgain (p < 0.0001) corresponding on average to 60% of the TK gain.
Conclusion60% of the TK gain was transferred to DCL gain. Correlations reflect the geometrical equivalence between PTK and DCL. The use of sagittal global measurements shows that DCL is equivalent to PTK and can be expressed as a function of pelvic parameters (DCL = PT + LL-PI). DCL must be considered to optimize the postoperative sagittal alignment of the spine.
... 10 A later study of exclusively thoracic hypokyphotic AIS patients reported an average final TK of 32° and a TK > 20° in all 24 participants. 11 Although the development of the ST2R technique allowed for successful TK corrections, including correction of hypokyphosis, it appears unable to control the TK apex level translocation. The role of the TK apex in maintaining the sagittal balance and affecting the quality of life is not well understood. ...
... TK angles of 9.4° for the ST2R group and 10.2° for the RR group improved to 25.2° and 16.4°, respectively. Clement and colleagues consistently demonstrated alleviation of hypokyphosis in all 10,11,32 4 An additional observation is the ability to correct the TK apex more with the ST2R technique. Although Faldini et al. 4 reported having improved the TK apex locations, they did not provide a quantification of this correction or a comparison to other techniques. ...
... As ST2R involves dual rod application, the forces are distributed along more rod material and pedicle screws, thus reducing the stress at single points. 11 This would likely reduce the risk of screw pullouts and rod flattening, thus preserving the translation ability of the correction maneuver. Finally, our described technique uses reducers also linked through connector segments to limit screw-rod friction and to improve ease of use. ...
OBJECTIVE
The objectives of this study were to apply the simultaneous translation on two rods (ST2R) maneuver involving rods contoured with a convexity at the desired thoracic kyphosis (TK) apex level and to assess the effects on the ability to support triplanar deformity corrections, including TK apex improvement, in patients with hypokyphotic adolescent idiopathic scoliosis (AIS).
METHODS
Using retrospective analysis, the authors examined the digital records that included 2- to 4-week, 1-year, and 2-year postoperative radiographic follow-up data of female hypokyphotic (TK < 20°) AIS patients (Lenke type 1–3) treated with ST2R. The authors assessed the corrections of triplanar deformities by examining the main Cobb angle, TK, rib hump, apical vertebral rotation, Scoliosis Research Society 22-item questionnaire scores, and TK apex translocation. In order to better grasp the potential of ST2R, the outcomes were compared with those of a historical matched case-control cohort treated with a standard rod rotation (RR) maneuver.
RESULTS
Data were analyzed for 25 AIS patients treated with ST2R and 27 patients treated with RR. The ST2R group had significant improvements in the main Cobb angle and TK, reduction in the rib hump size at each time point, and a final correction rate of 72%. ST2R treatment significantly increased the kyphosis apex by an average of 2.2 levels. The correction rate was higher at each time point in the ST2R group than in the RR group. ST2R engendered favorable TK corrections, although the differences were nonsignificant, at 2 years compared with the RR group (p = 0.056). The TK apex location was significantly improved in the ST2R cohort (p < 0.001). At the 1-month follow-up, hypokyphosis was resolved in 92% of the ST2R cohort compared with 30% of the RR cohort.
CONCLUSIONS
Resolving hypokyphotic AIS remains challenging. The ST2R technique supported significant triplanar corrections, including TK apex translocation and restoration of hypokyphosis in most patients. Comparisons with the RR cohort require caution because of differences in the implant profile. However, ST2R significantly improved the coronal and sagittal corrections. It also allowed for distribution of correctional forces over two rod implants instead of one, which should decrease the risk of screw pullout and rod flattening. It is hoped that the description here of commercially available reducers used with the authors’ surgical technique will encourage other clinicians to consider using the ST2R technique.
... Por último, hay que respetar varias reglas admitidas por todos los equipos: restaurar hasta el nivel más parecido a sus valores fisiológicos el plano sagital y permitir que el montaje no termine en el vértice de la cifosis torácica [28] . ...
... No es necesaria ninguna maniobra de distracción. [28,[36][37][38] Elección y colocación de los implantes. Al nivel torácico y lumbar, todas las vértebras se instrumentan de forma bilateral con tornillos. ...
Resumen
Los objetivos del tratamiento quirúrgico de las escoliosis idiopáticas han variado poco en las últimas décadas, pero la capacidad de los cirujanos para obtener el objetivo deseado ha mejorado. El objetivo final es realizar una artrodesis de buena calidad. Esta artrodesis de una extensión mayor o menor de la columna vertebral deformada debe permitir obtener una espalda armoniosa y correctamente equilibrada por encima de la pelvis. La desrotación de las vértebras escolióticas también es un objetivo que debe alcanzarse, porque participa en la calidad estética del resultado final. Desde el desarrollo de la instrumentación de Cotrel y Dubousset al comienzo de la década de 1980, se han desarrollado otras instrumentaciones y técnicas en paralelo. Las instrumentaciones anteriores, el uso de los tornillos pediculares, las bandas sublaminares y las técnicas de translación y de doblado in situ han permitido progresar en la calidad de la corrección tridimensional de la deformación escoliótica. Siempre existe la posibilidad de que surjan complicaciones relacionadas con el uso de estas distintas técnicas, pero se pueden minimizar mediante el respeto estricto las indicaciones, la planificación preoperatoria, el dominio perfecto de la técnica quirúrgica y la neuromonitorización peroperatoria.
... At best, using a method allowing precise bending according to the chosen angulation should lead to obtaining an optimal sagittal balance. The use of a kyphogenic reduction technique is then necessary to obtain this optimal TK [19][20][21]. ...
PurposeDistal thoracic kyphosis (DTK) equivalent to proximal lumbar lordosis (PLL) is the sum of pelvic tilt (PT) and the difference (Δ) between lumbar lordosis (LL) and pelvic incidence (PI): PLL = DTK = PT + Δ. With the assumption that proximal thoracic kyphosis (PTK) is similar to DTK, we propose the equation TK = 2(PT + LL − PI) to express the relationship between thoracic kyphosis (TK) and pelvic parameters. The objective of this work is to verify this relationship in a normal population.Methods
Full spine radiographs of 100 adolescents and young adults (13 to 20 years old), free from vertebral pathology, were analyzed. Measurements included pelvic parameters, LL, PLL, DLL, TK, PTK, DTK and C7 global tilt. The measured global TK was compared with the theoretical TK calculated according to the formula TK = 2(PT + LL − PI).ResultsThe difference between measured TK and calculated TK was + 2.3° and correlated with the C7 global tilt (r = 0.86). There was a significant linear regression between TK and PT + ∆ (p < 0.0001). Given radiographs’ inter-rater reliability of 5° for angled measurements, the p value (0.047) between measured TK and calculated TK is statistically significant to support the hypothesis.Conclusion
This work validates the formula TK = 2(PT + LL − PI) which allows the calculation of global TK as a function of PT, LL and PI. This calculated TK can be used as a target for sagittal correction of adolescents with spine deformities.Graphic abstractThese slides can be retrieved under Electronic Supplementary Material.
... Surgical strategies for the treatment of adolescent idiopathic scoliosis (AIS) continue to be developed and improvement in correction power is notable. 1 Pedicle screws have become the standard, but they are already being associated with a decrease in thoracic kyphosis and a risk of junctional kyphosis. 2,3 In 2003, Mazda et al. introduced the use of a new device: sublaminar bands (SB). The reduction principle that SBs use is the posteromedial translation of the spine, similar to that of Luque wires, but using malleable polyester bands instead of metallic wires. ...
Objective
In 2003, Mazda et al. introduced a new device for surgical correction of Adolescent Idiopathic Scoliosis (AIS) called sublaminar bands (SB). The reduction principle that SBs use is posteromedial spinal translation, similar to Luque’s wiring, but using polyester bands.
Methods
We performed a systematic review of the literature on this subject, evaluating the technique in terms of coronal correction, sagittal correction, bleeding, mean surgical time, loss of correction, infection, pseudoarthrosis, and neurological and other complications. The total search resulted in 14 articles published over the last 10 years. We found that the use of SBs in hybrid AIS correction instrumentations provides an average correction of 69% in the frontal plane, a 5° increase in thoracic kyphosis (average increase of 55%), overall complications of 4.5%, and no neurological complications were reported in any of the studies analyzed.. The mean blood loss was 682.5 mL and the mean surgical time was 228.6 minutes.
Conclusions
We conclude that the literature suggests that this instrumentation is safe, allows good correction in the frontal plane and great correction in the sagittal plane. As for complications, mean surgical time, and blood loss, their averages are lower than those of other constructions used for AIS. Level of evidence IIA; Systematic review.
... However, conventional all-pedicle screw constructs are not as powerful with respect to correction of hypokyphosis, unless rod derotation is the main method used to correct coronal deformity [1]. Results of the present study confirm that applying posteromedial translation using HIT produced equivalent POCC and superior POKC (p = 0.02), while avoiding worsening or inducing hypokyphosis with an overly aggressive thoracic kyphosis correction (Tables 3 and 4) [9][10][11][12][13][14]. Hypokyphosis (T5-T12 kyphosis angle < 20 • ) [15] was reported in 10% of the patients in this series at 2-years. ...
... Multivariable analyses in the present study confirmed the lack of significant correlation between SBd and curve correction based on curve flexibility (Table 5). These results corroborate findings from other studies involving alternative types of instrumentation [6][7][8][9][10][11][12][13][14][15][16]. Charalampidis et al. [5] reported no significant influence of screw density on patient-reported outcomes, curve correction, or reoperation rates in a nationwide study using data on patients treated surgically for AIS by full pedicle screws and hooks. ...
INTRODUCTION: Optimal pedicle screw density for the treatment of adolescent idiopathic scoliosis (AIS) remains unknown. It is not clear whether higher implant density results in better clinical outcomes. Large variability in implant density exists among hybrid or all screw constructs. Significant heterogeneity exists with respect to the number of sublaminar bands (SB) used, and the influence of SB density on curve correction in the treatment of AIS.
HYPOTHESIS: We hypothesize that increased SB density does not improve sagittal or coronal plane curve correction.
METHODS: A single-center, retrospective study of 131 consecutive patients (118 females) with Lenke 1 adolescent idiopathic scoliosis, all operated between 2012 and 2015 by two surgeons using identical surgical technique and type of instrumentation (SB hybrid instrumentation treatment). SB density was measured using the number of SB reported as well as the number of vertebrae instrumented. Radiographic measurements included preoperative thoracic curve flexibility, Cincinnati reduction index (CRI), and postoperative thoracic Cobb (POCC) and kyphosis (POKC) angle correction measured on immediate postoperative radiographs and at 2 years postoperatively.
RESULTS: Median patient age was 15.6 years (IQR, 12–18). The median SB density was 0.4 (IQR 0.4–0.5). No statistically significant correlation was identified between SB density and CRI (p = 0.71), POCC (p = 0.55), or POKC (p = 0.61) at 2-years postoperatively. Preoperative curve flexibility was found to have significant effect both on immediate (r = −3.02, p < 0.001) and 2-year (r = −2.69, p < 0.001).
DISCUSSION: SB utilized as a part of a hybrid construct for patients with flexible Lenke I AIS achieve satisfactory deformity correction regardless of SBd. The use of low SB density is appropriate for a subset of patients with flexible Lenke 1 adolescent idiopathic scoliosis.
... The correction occurs on the concave side, where implants must therefore be placed. The more recently described technique involving simultaneous translation on two rods combined with derotation on the concave side requires a high density of concave implants or connectors [3]. Another recently reported method uses translation of sublaminar bands and reduction on the concave rod [4,5]. ...
The various techniques available for scoliosis surgery via the posterior approach involve positioning implants on either side of the curve and reducing the deformity by manoeuvres on the concave rod or simultaneously on both rods. Correction solely via a direct convex rod manoeuvre would eliminate the need for implants on the concave side. This technique was used to treat thoracic adolescent idiopathic scoliosis in 23 patients with a mean age of 14 years and 9 months. Low-dose biplanar EOS radiographs were obtained before surgery, on post-operative day 7, and at last follow-up (at least 2 years after surgery) to allow comparisons of Cobb's angle (72°, 33°, and 35°, respectively), thoracic kyphosis (21°, 29°, and 26°), lumbar lordosis (58°, 50°, and 55°), and apical vertebra rotation (− 26°, − 12°, and − 11°). Although scoliosis requires corrections in all three dimensions, this technique seems to produce satisfactory outcomes while obviating the need for implants on the concave side, thereby decreasing the risk of iatrogenic adverse events.
Level of evidence
IV.
... Many publications have shown little evidence of significant variation or the decrease in TK after surgery with rotation of the rod, direct vertebral rotation, or cantilever reduction [1][2][3][4][5][6]. Conversely, translation techniques are more likely to improve TK [7][8][9][10][11]. It has been shown that the increase in TK by surgery leads to an increase in lumbar lordosis (LL) without correlation between reciprocal changes in TK and LL [12]. ...
... Consecutive patients with thoracic AIS, Lenke type 1 or 2 were collected from a prospective data base, in a pediatric orthopedic center between 2010 and 2015. Patients underwent a posterior thoracic selective fusion and correction by simultaneous translation on 2 rods (ST2R) with a minimum of 24 months postoperative follow-up [8,10,11,15]. Patients with instrumentation below L1 were excluded to better analyze the spontaneous evolution of uninstrumented LL. The rods were bent during the surgery according to the operator's experience and without proper planning apart from trying to adjust to the patient's pelvic incidence. ...
... A contemporary LL and TK increase during anterior [19] or posterior fusion has been reported [10,12]. However, no significant correlation was found between sagittal reciprocal changes [12]. ...
Purpose
In adolescent idiopathic scoliosis (AIS), there is a close relationship between thoracic kyphosis (TK) and proximal lumbar lordosis (PLL). The hypothesis states correction of hypokyphosis increases lumbar lordosis (LL) through increase in PLL after surgical correction of TK.
Methods
111 consecutive thoracic AIS, Lenke 1 or 2 who underwent posterior selective thoracic fusion with reduction by simultaneous translation on 2 rods and 2 years follow-up have been prospectively selected and analyzed. Instrumentations below L1 and anterior releases were excluded. Global TK and LL were measured by a dedicated software. Mean values were compared through T test, correlations assessed through Pearson’s coefficient.
Results
Global TK increased from 27° to 46° at the last follow-up (p < 0.0001) and LL from 58° to 65° (p < 0.0001). PLL increased by 8° (15°–23°), and distal lumbar lordosis remained stable (42°). The gains were higher for the Hypo-Kyphosis group than for the Normo-Kyphosis group (p < 0.001). There was a strong correlation (coef = 0.65) between TK and PLL as well as between the gain of TK and the gain of PLL (coef = 0.70). LL increased after the first postoperative month. At 1 month, there was a significant increase in pelvic tilt and decrease in sacral slope, offsetting the LL increase, and indicating a temporary pelvic retroversion.
Conclusions
Increase in TK led to increase in uninstrumented LL through increase in PLL with a continuous correlation between TK and PLL. These results allow surgeons to calculate the TK required during surgical correction of thoracic AIS to adapt LL to pelvic incidence.
Graphical abstract
These slides can be retrieved under Electronic Supplementary Material. Open image in new window
