Pectus Arcuatum: A Pectus Unlike Any Other.

BACKGROUND: Pectus arcuatum is often mistaken for a type of pectus carinatum. However, pectus arcuatum is a unique clinical form of pectus caused by premature obliteration of the sternal sutures (manubrial sternum, four sternebrae and xiphoïd process), whereas pectus carinatum is due to abnormal growth of the costal cartilage. In order to better describe pectus arcuatum, we analysed the files of patients with pectus arcuatum followed in our centers. METHODS: Multicenter retrospective study of young patients' files diagnosed with pectus arcuatum. RESULTS: The clinical diagnosis of pectus arcuatum was made in 34 patients with a mean age at diagnosis of 10.3 years (4-23 years). A chest profile X-ray or a CT scan was performed in 16 patients (47%) and confirmed the diagnosis of PA by the presence of a sternal fusion. It was complete in 12 patients. A malformation was associated in 35% of cases (Noonan syndrome 33%, scoliosis 25% or cardiopathy 16%). 11 patients (32%) had a family history of skeletal malformation. Orthopedic treatment was initiated in 3 patients without any success. 11 patients underwent surgical correction, which was completed in 7 of them. CONCLUSION: The diagnosis of pectus arcuatum is based on clinical experience and if necessary, on a profile chest X-ray showing the fusion of the sternal pieces. It implies the search for any associated malformations (musculoskeletal, cardiac, syndromic). Bracing treatment is useless for pectus arcuatum. Corrective surgery, based on a sternotomy associated with a partial chondro-costal resection, can be performed at the end of growth. LEVEL OF EVIDENCE: IV.

Deformity correction in thoracic adolescent idiopathic scoliosis.

AIMS: To compare the rates of sagittal and coronal correction for all-pedicle screw instrumentation and hybrid instrumentation using sublaminar bands in the treatment of thoracic adolescent idiopathic scoliosis (AIS). METHODS: We retrospectively reviewed the medical records of 124 patients who had undergone surgery in two centres for the correction of Lenke 1 or 2 AIS. Radiological evaluation was carried out preoperatively, in the early postoperative phase, and at two-year follow-up. Parameters measured included coronal Cobb angles and thoracic kyphosis. Postoperative alignment was compared after matching the cohorts by preoperative coronal Cobb angle, thoracic kyphosis, lumbar lordosis, and pelvic incidence. RESULTS: A total of 179 patients were available for analysis. After matching, 124 patients remained (62 in each cohort). Restoration of thoracic kyphosis was significantly better in the sublaminar band group than in the pedicle screw group (from 23.7° to 27.5° to 34.0° versus 23.9° to 18.7° to 21.5°; all p < 0.001). When the preoperative thoracic kyphosis was less than 20°, sublaminar bands achieved a normal postoperative thoracic kyphosis, whereas pedicle screws did not. In the coronal plane, pedicle screws resulted in a significantly better correction than sublaminar bands at final follow-up (73.0% versus 59.7%; p < 0.001). CONCLUSION: This is the first study to compare sublaminar bands and pedicle screws for the correction of a thoracic AIS. We have shown that pedicle screws give a good coronal correction which is maintained at two-year follow-up. Conversely, sublaminar bands restore the thoracic kyphosis better while pedicle screws are associated with a flattening of the thoracic spine. In patients with preoperative hypokyphosis, sublaminar bands should be used to restore a proper sagittal profile. Cite this article: Bone Joint J 2020;102-B(3):376-382.

Gait abnormalities following slipped capital femoral epiphysis treated with in situ fixation.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a common disorder in adolescent for which no consensus exists regarding management. The aim of the present study was to analyze gait modifications following SCFE treated with in situ fixation (ISF) and to relate it to radiologic stage. RESEARCH QUESTION: To verify if gait biomechanics are impaired in patients with SCFE and to try to determine a degree of slippage from which gait modifications would appear. METHODS: We evaluated 16 patients treated by ISF for SCFE with slippage ranging from 11° to 61°. Gait variables were compared to normal population according to age and walking speed and were normalized in Z-scores. RESULTS: Spatiotemporal parameters, mechanical and energetic variables were inferior to |1.5| Z-scores and considered as normal. Kinematics showed increase of pelvic tilt and hip adduction. Kinetic variables showed modifications with increased hip extension moment. There was also a strong increase in power of hip extensor. Hip extension moment and power of hip extensors were significantly correlated to radiologic stage. Analysis of ROC curves showed a cut-off value of slippage about 25°-30° affecting kinematics of pelvis and hip and kinetic variables. CONCLUSION: The gait variables were close to normal values. Main modifications were observed in kinematic and kinetic data with a significant increase in extension moment and power generated at the operated hip. This could participate to long-term joint degradation observed in SCFE, even in mild slips. The clinical message is to control regularly SCFE with initial slippage greater than >25-30° to allow for early diagnosis of premature hip osteoarthritis.