Heterotopic ossification after total hip arthroplasty: radiological comparison between a direct anterior approach without an orthopaedic table and a posterior approach.

INTRODUCTION: Heterotopic ossification (HO) occurs in almost ⅓ of total hip arthroplasties (THAs). A direct anterior approach (DAA) with an orthopaedic table is less likely to cause HO than a posterior approach. Without an orthopaedic table, the exposure of the femur requires additional soft tissue release. Soft tissue trauma leads to the production of HO inductors. Our study evaluated the incidence of HO 6 months after THA and compared the results between DAAs without an orthopaedic table and posterior approaches. METHODS: Retrospectively, 164 consecutive, primary THAs were included: 76 through a posterior approach and 88 through a DAA. The main objective was to measure the presence of HO on pelvis radiography 6 months after surgery. RESULTS: The incidence of HO was significantly higher in the DAA group than in the posterior approach group (47.7% vs. 27.6%, respectively; p < 0.01). The overall incidence of HO was 38.4%. No significant difference was found between the 2 approaches regarding the severity of HO. No significant risk factor for HO was identified other than the surgical approach. DISCUSSION: In our study, the incidence of HO after THA in patients undergoing DAA without an orthopaedic table was higher than in patients undergoing a posterior approach after 6 months of follow-up. This result is closely related to the surgical trauma. It suggests that the minimally invasive feature of a surgical approach cannot be dissociated from the overall conditions in which it is performed.

Reconstruction by allograft-prosthetic composite reverse shoulder arthroplasty after proximal humerus tumor resection: Clinical and radiographic assessment at a minimum 2years' follow-up.

INTRODUCTION: Reverse shoulder arthroplasty (RSA) is an option to conserve limb function after resection of proximal humerus malignancy. An allograft-composite RSA is an alternative to a tumor prosthesis, and can restore proximal humeral bone stock. The aim of the present study was to assess medium-term radiographic and clinical results for such composite implants. METHODS: Patients with malignant proximal humerus tumor treated by resection and reconstruction by composite RSA were retrospectively analyzed at a minimum 24months' follow-up. Clinical assessment used Constant score, Subjective Shoulder Value (SSV) and ADLER score. Standard radiographic work-up assessed allograft absorption and screened for implant loosening. RESULTS: Eleven patients were included, with a mean age of 51years (range: 19-87years) and mean 30months' follow-up (range: 24-84months). Mean tumor resection was 10cm (range: 6-17cm). Etiologies comprised chondrosarcoma (n=6), osteosarcoma (n=2), B-cell lymphoma (n=1) and single metastasis (n=2). Bony increased-offset allograft was associated to humerus reconstruction in 8 cases, and latissimus dorsi tendon transfer in 5 cases. Mean Constant score was 49 points, SSV 52%, and ADLER score 20 points. Increased glenoid implant offset associated to tendon transfer significantly improved anterior elevation and external rotation. Radiographic allograft consolidation to the native humerus was acquired in 73% of cases, while osteolysis in the epiphyseal-metaphyseal zone was found in 64%. There were no cases of humeral implant loosening. Glenoid allograft absorption was systematic (8/8 cases), without inducing loosening of the implant baseplate. CONCLUSION: Composite reverse shoulder arthroplasty is functionally effective after massive resection. However, allograft absorption is a drawback, casting doubt on continued use on the glenoid side. LEVEL OF EVIDENCE: IV.

Short-term outcomes of the Nexel total elbow arthroplasty.

BACKGROUND: Third-generation total elbow arthroplasties (TEAs) have shown better mechanical characteristics than older designs. However, these results remain purely mechanical and lack clinical evidence. The purpose of this study was to evaluate clinical and radiographic outcomes of the new-generation semiconstrained Nexel TEA performed at our center. MATERIALS AND METHODS: Between 2015 and 2017, 9 Nexel TEAs were implanted in 9 patients (mean age 61 years, range 38-71). Indication for further surgery, range of motion, mean Mayo Elbow Performance Score (MEPS), Subjective Elbow Value (SEV), radiolucency lines, outcome measures that included implant survival, complications, and revisions were assessed. RESULTS: The mean follow-up was 28 months (5-46 months). Average range of motion significantly improved from pre- to postoperation, with flexion from 120° (70°-140°) to 140° (130°-155°) and supination from 60° (0°-80°) to 80° (80°). Average MEPS improved from 33 (5-45) to 85 points (30-95). During the study period, 5 elbows (56%) experienced complications and 2 (22%) underwent revision. Aseptic humeral loosening was the main indication for revision. The survivorship rate without revision was 75% at 45 months. CONCLUSIONS: The short-term clinical results of the Nexel TEA are satisfactory. However, an unusually high rate of complications and revisions was observed, mainly at the humeral component. Further research with longer follow-up and more patients included are needed to validate this new prosthesis.