Advanced containment methods for Legg-Calvé-Perthes disease: triple pelvic osteotomy versus Chiari osteotomy.

INTRODUCTION: The goal of intervention in Legg-Calvé-Perthes disease (LCPD) is to prevent femoral head deformation by containing the head within the acetabulum. Currently, surgical containment methods are the mainstay of treatment, and pelvic osteotomies have been shown to be successful. They include triple pelvic osteotomy (TPO), Salter osteotomy, Chiari osteotomy and shelf procedure. The purpose of this study was to compare clinical and radiologic results for Chiari osteotomy and TPO in LCPD. METHODS: 29 children treated between 1980 and 2010 for LCPD in 2 centres were reviewed. 19 underwent TPO, and 10, Chiari osteotomy. Two independent observers assessed sequential radiographs and medical data. Each hip was preoperatively classed by clinical data, Catteral, Herring and Salter-Thompson classification, centre-edge angle (CE), and acetabular index (AI). The 2 groups were first tested for their comparability. After surgery the hips were classified by Stulberg classification, CE, AI, Harris Hip Score (HHS) and performance of further surgery. Chiari osteotomy and TPO have been secondary compared on these data by Wilcoxon test. RESULTS: Average follow-up was 4.2 years. The 2 groups were comparable before surgery. At first and last follow-up examination, statistically significantly superior results in patients with TPO regarding Stulberg classification (p = 0.01), AI (p = 0.002), pain (p = 0.02) and function (p = 0.01) in the HHS score were found. No differences were noticed concerning CE angle. CONCLUSIONS: In our series, TPO provided better radiologic and clinical outcomes compared to Chiari osteotomy, specially concerning the final Stulberg classification. We concluded that TPO should be preferred when indicated.

Restoration of thoracic kyphosis by simultaneous translation on two rods for adolescent idiopathic scoliosis.

INTRODUCTION: Sagittal and axial corrections of the three-dimensional deformity characteristic of scoliosis remain challenging. MATERIALS AND METHOD: The author developed a new technique for scoliosis correction consisting of the translation of vertebrae simultaneously towards two rods, which are pre-bent to the correct sagittal profile. Using two rods ensures both reduction and stabilization of the curve. The system includes stable anchorages with polyaxial-threaded extensions that connect to the rods. Deformity reduction is done by tightening nuts simultaneously and progressively on the two rods. Results demonstrate the efficiency of this technique to achieve normal thoracic kyphosis (>20°) in all 99 patients, with a mean gain of 19° of thoracic kyphosis in hypokyphotic cases. Coronal correction was 70-80% with a vertebral rotation gain of 40% where derotation connectors were used. CONCLUSIONS: In a large consecutive series of patients, this new technique allows to achieve a good 3D correction of the scoliosis.

Relationship between thoracic hypokyphosis, lumbar lordosis and sagittal pelvic parameters in adolescent idiopathic scoliosis.

PURPOSE: Sagittal spine and pelvic alignment of adolescent idiopathic scoliosis (AIS) is poorly described in the literature. It generally reports the sagittal alignment with regard to the type of curve and never correlated to the thoracic kyphosis. The objective of this study is to investigate the relationship between thoracic kyphosis, lumbar lordosis and sagittal pelvic parameters in thoracic AIS. METHODS: Spinal and pelvic sagittal parameters were evaluated on lateral radiographs of 86 patients with thoracic AIS; patients were separated into hypokyphosis group (n = 42) and normokyphosis group (n = 44). Results were statistically analyzed. The lumbar lordosis was lower in the hypokyphosis group, due to the low proximal lordosis. The thoracic kyphosis was not correlated with any pelvic parameters but with the proximal lordosis. The pelvic incidence was correlated with sacral slope, pelvic tilt, lumbar lordosis and highly correlated with distal lumbar lordosis in the two groups. There was a significant linear regression between thoracic kyphosis and proximal lordosis and between pelvic incidence and distal lordosis. CONCLUSIONS: We can consider that the proximal part of the lordosis depends on the thoracic kyphosis and the distal part depends on the pelvic incidence. The hypokyphosis in AIS is independent of the pelvic parameters and could be described as a structural parameter, characteristic of the scoliotic deformity.

Simultaneous translation on two rods to treat adolescent idiopathic scoliosis: radiographic results in coronal, sagittal, and transverse plane of a series of 62 patients with a minimum follow-up of two years.

STUDY DESIGN: Retrospective analysis of a consecutive cohort of 62 adolescent patients treated by posterior spinal fusion (PSF) with a minimum follow-up of 2 years. OBJECTIVE: To present sagittal and coronal results of a specific method of reduction: the simultaneous translation on 2 rods (ST2R). SUMMARY OF BACKGROUND DATA: The long-term outcome of surgically treated scoliosis is dependent not only on the coronal correction but also on restoration of sagittal curves. Recent publications confirm the moderate correction of thoracic hypokyphosis by posterior instrumentation with hooks or pedicle screws. METHODS: Radiographic parameters were measured preoperatively and at 6 weeks, 1 year, and last follow-up (between 2 and 7.4 years) in a consecutive cohort of 62 patients with adolescent idiopathic scoliosis (AIS) treated by PSF. All operative procedures were performed by the same surgeon using stable anchorages such as screws or self-stabilizing claws. The screws and claws included a polyaxial-threaded extension, which was fixed to the rod with connecting clamps. Reduction of the deformity was obtained by gradual and alternate tightening of the nuts on all threaded extensions on both rods, which allowed the vertebrae to gradually approach the rods while the translation maneuver was performed. RESULTS: In the coronal plane, the average main curve was reduced from 51° to 16° and maintained 70% of correction at last follow-up. In the sagittal plane, for patients with hypokyphosis (27 cases < 20°), the average kyphosis angle was significantly improved from 9° to 29° and maintained during follow-up (32°) with a mean gain of 23° (P < 0.0001). Only 1 patient reported hypokyphosis (18°) at last follow-up. For patients with normal kyphosis, the average gain was 8°. CONCLUSION: In a large consecutive cohort, reduction of scoliosis by ST2R is a simple method that allows 70% of correction in the coronal plane, equivalent to screw instrumentations, and a restoration of normal thoracic kyphosis.

Simultaneous translation on two rods is an effective method for correction of hypokyphosis in AIS: radiographic results of 24 hypokyphotic thoracic scoliosis with 2 years minimum follow-up.

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: Simultaneous translation on two rods (ST2R), performed by the same surgeon using stable anchorages such as screws or self-stabilizing claws. Radiographic parameters were measured preoperatively, at 1 month, 1 year and at 2 years minimum follow-up. In the coronal plane, the average main curve was significantly reduced from 51° to 17° and maintained at last follow-up, corresponding to an average correction of 67%. In the sagittal plane, the average kyphosis angle was significantly improved from 9° to 30° postoperatively and to 32° at last follow-up, corresponding to a mean gain of 23°. The 24 patients reported normal kyphosis at last follow-up (≥20°). Reduction of scoliosis by ST2R is an effective method that gives coronal correction equivalent to all screw constructs and allows restoration of normal thoracic kyphosis.

Restoration of thoracic kyphosis by posterior instrumentation in adolescent idiopathic scoliosis: comparative radiographic analysis of two methods of reduction.

STUDY DESIGN: A retrospective comparison of radiographic results for 2 consecutive series of patients treated for adolescent idiopathic scoliosis (AIS) by posterior instrumentations with thoracic screws using 2 methods of reduction: sequential approximation by cantilever reduction (CR) and simultaneous translation technique on 2 rods (ST2R). OBJECTIVE: To compare correction of thoracic hypokyphosis and coronal radiographic results between the 2 methods of reduction. SUMMARY OF BACKGROUND DATA: Publications concerning AIS confirm the moderate correction of thoracic hypokyphosis by posterior instrumentation with hooks and also with pedicle screws. METHODS: Forty-four patients with AIS (Lenke type 1, 2, 3) underwent a posterior spinal fusion and instrumentation (CR series: 21 patients--ST2R series: 23 patients). Three groups of preoperative kyphosis were generated: 12 patients with severe hypokyphosis (20 degrees ) (11 and 9 patients, respectively). Thoracic kyphosis (T4-T12) and Cobb angle measurements of major and minor curves were evaluated by an independent observer. The minimum follow-up was 2 years. RESULTS: At final follow-up, regarding patients with a severe preoperative hypokyphosis, the mean gain was 14 degrees in the CR series (8 degrees preoperative-22 degrees postoperative) and 27 degrees in the ST2R series (3-30 degrees ) (P = 0.018). Concerning patients with mild hypokyphosis, the mean gains were, respectively, 8 degrees (17-25 degrees ) and 18 degrees (16-34 degrees ) (P = 0.052). After surgery, 3 patients of CR series had hypokyphosis whereas the patients of the ST2R series all had normal kyphosis. In coronal plane, the mean correction of scoliosis was similar for both groups (75% vs. 69%; P = 0.177). CONCLUSION: Simultaneous translation on 2 rods provides a better correction of thoracic kyphosis than the sequential approximation by CR on patients with preoperative hypokyphosis. This surgical technique restores normal thoracic kyphosis in all cases.

Complications of scoliosis surgery in Prader-Willi syndrome.

STUDY DESIGN: Retrospective case series of 16 consecutive patients. OBJECTIVE: To evaluate the results of scoliosis surgery in Prader-Willi syndrome (PWS) with special emphasis on the complications and their risk factors. SUMMARY OF BACKGROUND DATA: PWS is a rare genetic disorder characterized by obesity, hypotonia, and frequent scoliosis. The literature dealing with scoliosis surgery in PWS consists of only few case reports. Surgical treatment was reported to be difficult with frequent and severe complications. METHODS: Sixteen patients (3 males, 13 females) in 63 presenting scoliosis and PWS were operated on between 1974 and 2004. Preoperative, postoperative and last follow-up clinical and radiologic data were analyzed. Complications, treatment, and outcome were investigated. RESULTS: Mean age at scoliosis diagnosis was 6.2 years (range 0.5-13.5). Mean age at surgery was 12.3 years (range 5-15). Mean follow-up was 5.4 years (range 2-18). There were 9 major complications (4 severe kyphosis above fusion, 2 deep infections, 1 transient paraplegia, 1 pseudarthrosis, 1 delayed wound healing). The 4 kyphosis required reoperation, 3 of which were complicated with permanent spinal cord injury. Minor complications affected 6 patients. CONCLUSION: Scoliosis surgery is frequently necessary in PWS and is associated with high rate of complications. These are often related to specific features of this syndrome the surgeon should recognize and consider.