Results of talectomy for inveterate or recurrent clubfoot.

INTRODUCTION: The aim of the present study was to define indications for talectomy in congenital paralytic, dystrophic or idiopathic, inveterate or recurrent, clubfoot. HYPOTHESIS: Talectomy is a valid option for paralytic, dystrophic or idiopathic, inveterate or recurrent, clubfoot. PATIENTS AND METHODS: A single-center retrospective series comprised 52 clubfeet in 31 patients. Etiology was paralytic in 34 feet (65%) (17 arthrogryposes, 10 myelomeningoceles, 4 encephalopathies, 3 peripheral neuropathies), dystrophic in 6 (12%) and idiopathic in 12 (23%). In 27 feet, there was history of surgery (52%). Mean age at talectomy was 4.7 years. In 45 feet (87%), there were associated procedures (soft-tissue release, tendon surgery, calcaneal or lateral arch osteotomy, tibiocalcaneal fusion) and talectomy was isolated in 7 feet (13%). Mean follow-up was 9 years. Final assessment was based on the modified Ghanem and Seringe classification (G&S) and the Ankle-Hindfoot Scale (AHS). RESULTS: All feet required at least one complementary procedure, either in the same step or as revision. Revision surgery was performed in 17 cases (33%), including all 7 feet with isolated talectomy (7 calcaneal tendon lengthenings, 10 mid- or hind-foot osteotomies, 6 tibiocalcaneal fusions, one calcaneocuboid fusion, and 2 progressive corrections by external fixator). Finally, 33 feet (63%) had good G&S results, 44 (85%) were pain-free, and 40 (77%) were plantigrade. DISCUSSION: Talectomy for paralytic or dystrophic inveterate or recurrent clubfoot provided satisfactory medium-term results. Associated to other procedures, it achieves a pain-free plantigrade foot in most cases. Tibiocalcaneal fusion has an analgesic effect. Talectomy may, however, not be indicated in idiopathic clubfoot, given the patients' high functional demand and the existence of alternative treatments. LEVEL OF EVIDENCE: IV, retrospective series.

Does the cement mantle thickness influence the glenoid loosening in anatomic total shoulder arthroplasty? An experimental study.

BACKGROUND: Glenoid component loosening is the most frequent failure mode. Few data are available on the effect of thickness of cement on glenoid loosening. The purpose of this study is to determine if the cement mantle thickness influences the mode and localization of loosening. Our hypotheses are: 1) failure is caused by traction stresses generated within the cement mantle and 2) a thicker cement mantle amplifies the rocking horse effect. METHODS: Using bone substitute, an experimental protocol was designed to compare loosening of a keeled glenoid prosthesis in axial traction and off-centered-load, to recreate the rocking-horse effect (1.000.000 cycles). Different standardized mantle of cement between the back of the glenoid and the foam were tested (0-1 - 2-3 mm). The displacement of the polyethylene was assessed with an LVDT (Linear Variable Differential Transformer) gauge when the prosthetic humeral head loaded the opposite part of the implant. RESULTS: The loosening took place within the keel of the implant, and at the polyethylene-cement interface in traction if there was cement at the back of the polyethylene. For cycling loading, we observed a loosening at this interface, with associated fracture of the cement, only for cement 2 and 3 mm thick. CONCLUSION: This experimental study suggests that the cement mantle should be as thin as possible between the back of the implant and the sub-chondral bone but should be optimized around the keel of the implant. LEVEL OF EVIDENCE: Basic Science Study.

CT arthrography and anatomical correlation of the bare area of the ulnar trochlear fossa: a risk of misdiagnosis of cartilage ulcerations.

AIMS: There is a variable bare area on the ulnar trochlear fossa that may be somehow interpreted as a cartilage defect. We aimed to correlate radiological images and dissections of this bare spot with CT arthrography imaging. MATERIALS AND METHODS: We conducted a double study that included 10 unpaired fresh-frozen human cadaveric elbows (CT arthrography + dissection) and 40 CT arthrography of patients to investigate the 3-D architecture of the trochlear fossa of the ulna. Positioning, shape and measurements of the bare spot of each ulna were measured and correlated. A total of 40 were analyzed with this protocol of measurements to validate the anatomical findings. RESULTS: The bare spot area is located 15.8 mm from the tip of the olecranon and 13.8 mm from the coronoid process (mean values). This area measures 4.1 mm in cranio-caudal plane, 2.2 mm in transversal plane. This area is located above a small subchondral tubercle that measures 1.0 mm in antero-posterior axis. No significant difference has been found between left and right elbow regarding its positioning and shape. A significant difference has been found between genders regarding the positioning of this area but not according to its shape. CONCLUSION: The ulnar trochlear notch has a small area without cartilage. This bare area is located at the site of fusion of the different ossification center of the proximal ulna. It should not be interpreted as a chondral lesion. The existence of a subchondral tubercle clearly indicates that this uncovered zone is normal. Radiologist should consider this when interpreting elbow CT arthrography.

Morphological analysis of the glenoid version in the axial plane according to age.

PURPOSE: Total shoulder arthroplasty planning requires a preoperative assessment of the glenoid version. This study aimed to determine the morphologic profile of the glenoid cavity and our null hypothesis was that age may affect the spiraling aspect. METHOD: 114 CT arthrographies of patients from 15 to 78 years old were included. Four groups were defined according to age: 15-29, 30-44, 45-59 years old, and over 60. The version of the glenoid was measured in the axial plane according to the most common method: a line is drawn between the osseous anterior and posterior margins of the glenoid and the version corresponds to the angle between this line and the transverse axis of the glenoid. The transverse axis of the scapula is determined by a line drawn from the center of the glenoid fossa to the medial border of the scapula. The axial plane (perpendicular to the supero-inferior axis of the glenoid cavity) was defined by multiplanar reconstruction. The measurements were performed at three regions of interest: the level of the coracoid process (region A), the level of the notch on the anterior border of the glenoid (region B), and the region of the greater antero-posterior diameter (region C). RESULTS: 96 % of the glenoid cavities included were retroverted. The mean version in region A was 11.9° (0-24.3, S-D 5.2), in region B 6.85° (-5.2 to 12.1, S-D 4.13) and in region C 4.04° (-7.7 to 11.1, S-D 4.04). The difference between the mean version of region A and region B was 5.02° and the difference between the mean version of the region B and the mean version of the region C was 2.81°. When considering the rate of change of the mean version between two adjacent regions, no difference was observed between the four groups of age. DISCUSSION: The analysis showed the importance of the axial reconstruction plan chosen to allow interpretable and reproducible measures. A decreasing version of the glenoid superior-to-inferior was observed, presenting a spiraling twist as described in previous studies. The profile of variation does not change in the four groups of patients included. The reconstruction of an articular surface as close to the anatomy as possible would also participate in establishing the muscular balance and the constraints on implants. Up to now, implants do not take into account this cranio-caudal twisting.

Sagittal balance correction of idiopathic scoliosis using the in situ contouring technique.

PURPOSE: Idiopathic scoliosis can lead to sagittal imbalance. The relationship between thoracic hyper- and hypo-kyphotic segments, vertebral rotation and coronal curve was determined. The effect of segmental sagittal correction by in situ contouring was analyzed. METHODS: Pre- and post-operative radiographs of 54 scoliosis patients (Lenke 1 and 3) were analyzed at 8 years follow-up. Cobb angles and vertebral rotation were determined. Sagittal measurements were: kyphosis T4-T12, T4-T8 and T9-T12, lordosis L1-S1, T12-L2 and L3-S1, pelvic incidence, pelvic tilt, sacral slope, T1 and T9 tilt. RESULTS: Thoracic and lumbar curves were significantly reduced (p = 0.0001). Spino-pelvic parameters, T1 and T9 tilt were not modified. The global T4-T12 kyphosis decreased by 2.1° on average (p = 0.066). Segmental analysis evidenced a significant decrease of T4-T8 hyperkyphosis by 6.6° (p = 0.0001) and an increase of segmental hypokyphosis T9-T12 by 5.0° (p = 0.0001). Maximal vertebral rotation was located at T7, T8 or T9 and correlated (r = 0.422) with the cranial level of the hypokyphotic zone (p = 0.003). This vertebra or its adjacent levels corresponded to the coronal apex in 79.6 % of thoracic curves. CONCLUSIONS: Lenke 1 and 3 curves can show normal global kyphosis, divided in cranial hyperkyphosis and caudal hypokyphosis. The cranial end of hypokyphosis corresponds to maximal rotation. These vertebrae have most migrated anteriorly and laterally. The sagittal apex between segmental hypo- and hyper-kyphosis corresponds to the coronal thoracic apex. A segmental sagittal imbalance correction is achieved by in situ contouring. The concept of segmental imbalance is useful when determining the levels on which surgical detorsion may be focused.

Could an osteoinductor result in degeneration of a neurofibroma in NF1?

We report a case of fatal evolution of neurofibromatosis in a young boy. A laminectomy was performed when he was 9 years old. A secondary hyperkyphosis led to many surgeries resulting in recurrent malunions. When he was 23 years old, a breakage of his rods was treated by a new instrumentation and a T12-L1 interbody cage fitted with rh-BMP. Five months later, he developed a huge posterior tumour on his back. The biopsy diagnosed a neurofibrosarcoma. The growth of the tumour was extremely rapid. He died after several months from a septic shock. NF1 is characterised by neurofibromas that have a possibility of malign degeneration and conversion to a sarcoma. However, the chronology, rapidity of evolution and the exceptional volume of the tumour made us wonder whether the BMP had a part of responsibility as osteoinductor in the malignant degeneration, in this particular case, of neurofibromatosis. It seemed important to point out this case to the medical community.