One-Way Self-Expanding Rod in Neuromuscular Scoliosis: Preliminary Results of a Prospective Series of 21 Patients.

BACKGROUND: Fusionless techniques for the treatment of neuromuscular early-onset scoliosis (EOS) are increasingly used to preserve spinal and thoracic growth and to postpone posterior spinal fusion (PSF). These techniques have greatly improved thanks to magnetically controlled growing rods, which allow the avoidance of repeated surgery. However, the surgery-related complication rate remains high. The objective of the current study was to report the preliminary outcomes of 21 patients with neuromuscular EOS who were treated with a 1-way self-expanding rod (OWSER). This device was designed to avoid repeated surgery and preserve spinal and thoracic growth thanks to its free rod sliding. METHODS: Patients with neuromuscular EOS who underwent OWSER fixation were prospectively reviewed; follow-up was a minimum of 3 years. The instrumentation relies on a bipolar construct from T1 to the sacrum, with proximal fixation by double thoracic hook-claws and distal fixation by iliosacral screws. The device comprises a rod with a notched part sliding in 1 direction inside a domino. Changes in Cobb angle, pelvic obliquity, thoracic kyphosis, lumbar lordosis, T1-S1 and T1-T12 length, space available for the lung, and chest width were assessed. Complications were reviewed. RESULTS: The mean age at surgery was 10.5 years. The mean follow-up was 3.9 years. The mean pelvic obliquity improved from 20° preoperatively to 8° postoperatively and to 6° at the latest follow-up. The mean Cobb angle improved from 66° preoperatively to 38° postoperatively and to 32° at the latest follow-up. The mean preoperative kyphosis was reduced from 41° to 26° at the latest follow-up (p = 0.14). The mean lordosis was 34° preoperatively and 38° at the latest follow-up. The mean growth per month was 0.8 mm for the T1-T12 segment and 1.5 mm for T1-S1. The global complication rate was 38% (2 surgical site infections, 3 cases of lack of rod expansion, 1 case of pyelonephritis, and 2 central venous catheter-related infections). No PSF had been performed at the latest follow-up. CONCLUSIONS: Use of the OWSER with a minimally invasive bipolar technique for neuromuscular EOS provided satisfactory correction of spinal and pelvic deformities at 3 years of follow-up. A longer follow-up is required. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Anterior and lateral overcoverage after triple pelvic osteotomy in childhood for developmental dislocation of the hip with acetabular dysplasia: Frequency, features, and medium-term clinical impact.

BACKGROUND: Triple pelvic osteotomy (TPO) is a treatment option in children and adolescents with residual acetabular dysplasia after developmental dislocation of the hip (DDH). However, TPO to redirect the acetabulum is often blamed for anterior and lateral overcoverage of the femoral head. The main objectives of this study were to assess the potential clinical impact, frequency, and radiological features of acetabular overcorrection. Evidence of post-operative remodelling and associations linking younger age at surgery and/or dysplasia severity to the existence and magnitude of overcorrection were sought. HYPOTHESIS: Acetabular overcorrection has little or no clinical impact. PATIENTS AND METHODS: TPO was performed on 41 hips in 31 patients at a mean age of 6.3 years (range, 3.0-15.2 years). Mean follow-up was 13.8 years (range, 5.4-28.7 years) and mean age at last re-evaluation was 22.1 years (range, 13-39 years). Clinical outcomes were assessed based on the Harris Hip Score (HHS) and Postel-Merle d'Aubigné (PMA) score. Radiographs were used to look for a cross-over sign (CO+) and to measure the vertical-centre edge (VCE) and vertical-centre anterior (VCA) angles and the acetabular index (AI). Overcorrection was defined as AI≤0° and/or VCE≥35° and/or VCA≥40° and/or CO+. RESULTS: The HHS and PMA score values were good or excellent for 39 (94%) hips. One or more parameters indicated overcorrection of 33 (80.5%) hips. No significant differences were found between the overcorrected hips and the hips with normal parameters. DISCUSSION: TPO effectively corrects residual acetabular dysplasia. Overcorrection is common in all three planes but has little clinical impact in young adults. The high frequency of overcorrection mandates a careful pre- and intra-operative evaluation of acetabular version. LEVEL OF EVIDENCE: IV, retrospective study.

Does patella lowering improve crouch gait in cerebral palsy? Comparative retrospective study.

BACKGROUND: Patella lowering aims to improve quadriceps function as a means of correcting crouch gait in patients with cerebral palsy. Few studies have assessed the effects of patella lowering as a component of multilevel surgery. HYPOTHESIS: Including patella lowering into the components of multilevel surgery is beneficial in patients with crouch gait and patella alta. MATERIAL AND METHODS: In 12 lower limbs with patella alta (Caton-Deschamps index>1.4) in 41 children with cerebral palsy, patella lowering was performed, without distal femoral extension osteotomy or hamstring release. Among limbs with similar surgical procedures (e.g., hamstring lengthening, rectus femoris transfer) except for patella lowering, controls were selected retrospectively by matching on a propensity score for patella lowering. The propensity score was computed based on preoperative knee flexion contracture, knee extension lag, and minimum knee flexion at mid-stance. Clinical and 3D kinematic data were compared between the two groups. RESULTS: The improvement in minimum knee flexion at mid-stance was significantly greater in the group with patellar lowering (-24°±12°vs. -12°±7°). The Gait Deviation Index improved similarly in the two groups. Knee flexion contracture improved only in the group with patellar lowering. Extension lag did not improve in either group. Peak knee flexion during the swing phase remained unchanged in both groups. DISCUSSION: Patellar lowering is effective in diminishing minimum knee flexion at mid-stance in patients with patella alta and crouch gait due to cerebral palsy. Patellar lowering has not adverse effects on gait. These findings cannot be assumed to apply to patients with normal patellar height. LEVEL OF EVIDENCE: IV (retrospective study).

Contribution of clinical gait analysis to single-event multi-level surgery in children with cerebral palsy.

Clinical gait analysis (CGA) has been proven useful in understanding the gait disturbances seen in children and adolescents with cerebral palsy. Another major benefit provided by CGA is a clinical and scientific evaluation of how orthopaedic surgical procedures modify gait. The information provided by instrumented CGA complements the clinical data, and the two must be interpreted jointly. Although there is some variability in the surgical details of therapeutic strategies, CGA undoubtedly influences the planning of surgery. Although CGA improves surgical outcomes, these remain challenging to predict. CGA seems cost-effective. Internal hip rotation gait is used as an example to illustrate those benefits.

Propulsion and Instability of a Flexible Helical Rod Rotating in a Viscous Fluid.

We combine experiments with simulations to investigate the fluid-structure interaction of a flexible helical rod rotating in a viscous fluid, under low Reynolds number conditions. Our analysis takes into account the coupling between the geometrically nonlinear behavior of the elastic rod with a nonlocal hydrodynamic model for the fluid loading. We quantify the resulting propulsive force, as well as the buckling instability of the originally helical filament that occurs above a critical rotation velocity. A scaling analysis is performed to rationalize the onset of this instability. A universal phase diagram is constructed to map out the region of successful propulsion and the corresponding boundary of stability is established. Comparing our results with data for flagellated bacteria suggests that this instability may be exploited in nature for physiological purposes.

Fusionless surgery in early-onset scoliosis.

BACKGROUND: Surgical treatment of early-onset scoliosis has greatly developed in recent years. Early-onset scoliosis covers a variety of etiologies (idiopathic, neurologic, dystrophic, malformative, etc.) with onset before the age of 5 years. Progression and severity threaten respiratory development and may result in respiratory failure in adulthood. Many surgical techniques have been developed in recent years, aiming to protect spinal and thoracic development. MATERIAL AND METHODS: Present techniques are based on one of two main principles. The first consists in posterior distraction of the spine in its concavity (single growing rod, or vertical expandable prosthetic titanium rib [VEPTR]), or on either side (dual rod); this requires iterative surgery, for lengthening, unless motorized using energy provided by a magnetic system. The second option is to use spinal growth force to lengthen the assembly; these techniques (Luque Trolley, Shilla), using a sliding assembly, are known as growth guidance. RESULTS: These techniques are effective in controlling early scoliotic deformity, and to some extent restore spinal growth. However, they show a high rate of complications: infection, rod breakage, spinal fixation pull out and, above all, progressive spinal stiffness, reducing long-term efficacy. Respiratory gain is harder to assess, as thoracic expansion does not systematically improve respiratory function, particularly due to impaired compliance of the thoracic cage.

Anterior hip dislocation in children with neurological disorders. A retrospective study of ten operated hips.

INTRODUCTION: Patients with neurological disorders often exhibit dislocation or subluxation of the hip. Anterior dislocation is rare, little known, and often associated with deformities. Its surgical treatment has rarely been studied. HYPOTHESIS: Hip surgery (with open reduction, femoral and pelvic osteotomy, and adapted tenotomies) could provide a centered hip that is supple and painless. MATERIALS AND METHODS: Ten hips (seven dislocated, three subluxated) in six patients with a mean age of 8.3 years were operated between 1995 and 2009 and revised with a mean follow-up of 6.5 years. The deformities comprised four cases of abduction, extension, and external rotation and six cases of adduction, extension, and external rotation. Four patients had lost the ability to walk or maintain the sitting position. Intraoperative findings were an increased neck-shaft angle, anterosuperior acetabular dysplasia, and in only one case increased femoral anteversion. In all cases of dislocation, open reduction was necessary, and all hips underwent pelvic and femoral osteotomy. RESULTS: At the longest follow-up, hips were centered on X-rays. Five patients could walk or sit as they had done before and hips were supple, with no deformities. DISCUSSION: The study of deformities and intraoperative findings is mandatory for surgical management, whose mid-term results are encouraging. Femoral anteversion does not seem to be excessive, but the increase of femoral valgus is constant, as is anterosuperior acetabular dysplasia. We propose a decision tree for the management of these patients. DESIGN OF STUDY: Retrospective. LEVEL OF SCIENTIFIC EVIDENCE: IV.

Aromatase inhibitor-induced modulation of breast density: clinical and genetic effects.

BACKGROUND: Change in breast density may predict outcome of women receiving adjuvant hormone therapy for breast cancer. We performed a prospective clinical trial to evaluate the impact of inherited variants in genes involved in oestrogen metabolism and signalling on change in mammographic percent density (MPD) with aromatase inhibitor (AI) therapy. METHODS: Postmenopausal women with breast cancer who were initiating adjuvant AI therapy were enrolled onto a multicentre, randomised clinical trial of exemestane vs letrozole, designed to identify associations between AI-induced change in MPD and single-nucleotide polymorphisms in candidate genes. Subjects underwent unilateral craniocaudal mammography before and following 24 months of treatment. RESULTS: Of the 503 enrolled subjects, 259 had both paired mammograms at baseline and following 24 months of treatment and evaluable DNA. We observed a statistically significant decrease in mean MPD from 17.1 to 15.1% (P<0.001), more pronounced in women with baseline MPD ≥20%. No AI-specific difference in change in MPD was identified. No significant associations between change in MPD and inherited genetic variants were observed. CONCLUSION: Subjects with higher baseline MPD had a greater average decrease in MPD with AI therapy. There does not appear to be a substantial effect of inherited variants in biologically selected candidate genes.

Postoperative perceived health status in adolescent following idiopathic scoliosis surgical treatment: results using the adapted French version of Scoliosis Research Society Outcomes questionnaire (SRS-22).

PURPOSE: Assessing functional outcome from patient-based outcomes questionnaires are essential to the evaluation of adolescent idiopathic scoliosis surgical treatment METHODS: At the minimum follow-up of 2 years, 45 operated on adolescent idiopathic scoliosis patients were mailed the French version of the Scoliosis Research Society Outcome Instrument (SRS-22) questionnaires containing items on pain, activities of daily living, and satisfaction. RESULTS: Mean values of the SRS-22 domains were 3,66 for the Pain domain, 3,85 for the Self-perceived image domain, 4,32 for the Function domain, 3,52 for the Mental health domain and 4,12 for the Global satisfaction with management domain. Mean value of the global SRS-22 score was 3,88. We showed no differences in functional SRS-22 health status in patients according to the type of curve (Lenke classification). We showed statistically significant correlations between the gain of Cobb angle and Patients self-image and function domain scores. There was a statistically significant correlation between preoperative Cobb angle and patient satisfaction with management. CONCLUSIONS: Even if Function and Self-image scores in our patients are close to control group values, indicating good short to mid-term outcome of surgical treatment, scores for pain and mental health status were significantly lower in patients than controls. Long-term follow-up studies conducted by multiple surgeons over successive generations are mandatory to assess clinical significance of these differences. LEVEL OF EVIDENCE: Level IV. Retrospective study.

Rectus femoris transfer in multilevel surgery: technical details and gait outcome assessment in cerebral palsy patients.

INTRODUCTION: In children with cerebral palsy the abnormal activity of the rectus femoris (RF) during the swing phase results in "stiff-knee gait". Transferring the RF to a knee flexor tendon improves this stiffness. The effect may be limited by adhesions from scar tissue or from angular deviations along the surgically created muscle tendon route. HYPOTHESIS: The goal of this study was to assess the effect on gait of a single event multilevel surgery protocol, and provide a detailed description of the transfer technique. PATIENTS AND METHODS: Forty-eight RF transfers were studied in 26 children and adolescents 12 ± 3 years old after a follow up of 25 ± 10 months. Quantified gait analysis was performed pre- and postoperatively to calculate spatiotemporal variables, 3D kinematics, the Gait Deviation Index (GDI) and a knee stiffness score (Goldberg index). A standardized surgical procedure was followed: RF release, gracilis tendon preparation as well as the transfer and suture techniques are described. RESULTS: Step length improved. Gait velocity and cadence were not modified. Gait quality improved (+13 ± 11 GDI) with an inverse relationship between the preoperative GDI and its improvement. Improvement of the preoperative Goldberg index in 74% of the cases was due to modifications of knee ROM from toe-off to peak flexion (+7°), total knee ROM (+16°) and timing of peak knee flexion in percentage of swing (from 51 to 40% of swing). DISCUSSION: The surgical protocol presented here is discussed in relation to the results. LEVEL OF EVIDENCE: IV, retrospective study.

Risk factors for graft dysfunction in the late period of renal transplantation.

INTRODUCTION: Risk factors traditionally associated with kidney graft dysfunction after transplantation are delayed graft function, acute cellular rejection episodes, deceased donor organ source (particularly more than 50 years old), and HLA mismatch. Socioeconomic factors, such as income, education, and type of health insurance, have been reported in some studies. OBJECTIVE: To evaluate the risk factors traditionally associated with worse function of the transplanted kidney and the role of socioeconomic variables among our population. DESIGN OF STUDY: A cohort with 69 patients transplanted in the period 2003 to 2006 was assessed for predictors for a creatinine clearance estimated to be less than 60 mL/min or stage 3 or greater of renal dysfunction at 1 year of follow-up. CONCLUSION: Upon bivariate regression analysis, acute tubular necrosis [odds ratio (OR) 6.93 (1.9-24), P = .03], and bacterial infection [OR 4.13 (1.4-12), P < .01] were predictors of risk, which was also observed among transplants of kidneys from deceased donors [OR 2.67 (0.9-7.6), P = .07] or donors aged more than 49 years [OR 4.22 (0.9-18.1), P = .06]. Better education was a significant protective factor [OR 0.3 (0.1-0.9), P = .02]. Upon multivariate logistic regression analysis delayed graft function [OR 5.1 (1.3-20.5), P = .02] and severe bacterial infection [OR 3.9 (1.23-12.9), P = .02] were predictors; there was no association with socioeconomic factor.

Multiple lumbar plexus neurotizations of the ninth, tenth, and eleventh intercostal nerves.

The topographic anatomy of the lower intercostal nerves is less known than the upper ones except for the twelfth intercostal nerve. It is possible to use the lower intercostal nerves to carry out a neurotization of the lumbar roots. We studied the anatomy of the ninth, tenth, and eleventh intercostal nerves in order to specify the data of descriptive and topographic anatomy allowing to carry out their harvesting under good conditions. Ninth, tenth, and eleventh intercostal nerves of 50 cadavers were dissected. The proximal part of the nerve in the posterior intercostal space was exposed through a posterior approach. The lateral intercostal space was exposed through a lateral approach, under the latissimus dorsi, which made it possible to harvest the intercostals nerve. The proximal course of the nerve in posterior intercostals space was the same in all the cases. The nerve moves obliquely towards the outside to reach the lower border of the rib. The exit of posterior intercostal space is a fibrous strait that marks the entry of a channel between two muscular layers. We describe an aponevrotic channel in which the nerve and the vessels are, immediately at the lower border of the cranial rib. The mean total length of intercostal nerve harvested by our technique was 17.96 cm for the ninth intercostal nerve, 17.14 cm for the tenth intercostal nerve, and 15.94 cm for the eleventh intercostal nerve. The bifurcation of the intercostal nerve in a deep branch and the ramus cutaneus lateralis was found in the majority of the cases, from 9.5 to 21 cm of the emergence of the intercostal nerve in posterior intercostal space. This anatomical study of the ninth, tenth, and eleventh intercostal nerves in posterior intercostal space and lateral intercostal space appears to us to allow the realization of a reliable surgical harvesting.

Anatomical study of the paraspinal approach to the lumbar spine.

The original description of the paraspinal posterior approach to the lumbar spine was for spinal fusion, especially regarding lumbosacral spondylolisthesis treatment. In spite of the technical details described by Wiltse, exact location of the area where the sacrospinalis muscle has to be split remains somewhat unclear. The goal of this study was to provide topographic landmarks to facilitate this surgical approach. Thirty cadavers were dissected in order to precisely describe the anatomy of the trans-muscular paraspinal approach. The level of the natural cleavage plane between the multifidus and the longissimus part of the sacrospinalis muscle was noted and measurements were done between this level and the midline at the level of the spinous process of L4. A natural cleavage plane between the multifidus and the longissimus part of the sacrospinalis muscle was present in all cases. There was a fibrous separation between the two muscular parts in 55 out of 60 cases. The mean distance between the level of the cleavage plane and the midline was 4 cm (2.4-5.5 cm). In all cases, small arteries and veins were present, precisely at the level of the cleavage plane. We found it possible to easily localize the anatomical cleavage plane between the multifidus part and the longissimus part of the sacrospinalis muscle. First the superficial muscular fascia is opened near the midline, exposing the posterior aspect of the sacrospinalis muscle. Then, the location of the muscular cleft can be found by identifying the perforating vessels leaving the anatomical inter-muscular space.