Comparative analysis of 'functional excision' of heterotopic ossification around the hip - computed tomography (CT) navigation guided versus conventional excision.

PURPOSE: We aim to analyse and compare the efficacy of the excision of HO around the hip with and without CT-guided navigation. We also aim to compare the functional outcome between CT navigation guided versus conventional excision of HO. PATIENTS AND METHODS: This study is a retrospective analysis of prospectively collected data from 2015 to 2022. There were 23 patients (24 hips) in the final cohort. Intraoperative CT navigation guided excision was performed in 7 hips and conventional excision of HO was done in 17 hips. The HO was classified by Brooker's grading in radiographs. CT scan was taken preoperatively in all patients to exactly identify the volume, location and preoperative planning. The functional outcome was analysed according to Harris Hip Score (HHS) and International Hip Outcome Tool (iHOT) for self-ambulatory patients and improvement in the sitting or nursing care was assessed in patients mobilising with wheelchair or walker support. Any complications or recurrence noted postoperatively and in follow-up were recorded. RESULTS: The mean follow-up was 41.2 months in the CT navigation-guided excision group and 55 months in the conventional excision group. According to Brooker's grading, grade IV was present in 20 hips and grade III in four hips. Twelve patients were self-ambulatory and the other 12 patients were requiring support for mobilisation. There was a significant improvement in the HHS from 21.3 ± 3.7, 18.3 ± 2.5 preoperatively to 75.2 ± 8.3, 72.2 ± 4.3 postoperatively in the CT navigation guided and conventional group respectively (p < 0.001) in the self-ambulatory group. There was one anterior wall and one partial posterior wall fracture in the conventional group. One patient in the conventional group had a deep infection and recurrence. One patient had a superficial infection and another had superficial vein thrombosis in the CT guided excision group. CONCLUSION: Intraoperative CT navigation helps to exactly localize the HO and facilitates safe excision. Functional excision of the HO leads to better nursing care and functional outcomes between both groups.

Outcomes of conversion total hip arthroplasty for failed fixation of intertrochanteric fractures with monoblock distal-loading reconstruction stem.

PURPOSE: The aim of our study was to analyze the clinical and radiological outcomes of conversion total hip arthroplasty (THA) for failed fixation of proximal femur fractures with monoblock grit-blasted titanium reconstruction stem (Wagner self-locking stem, Zimmer). PATIENTS AND METHODS: Thirty-nine patients were included in this retrospective analysis undergoing conversion THA for failed cephalomedullary nail or dynamic hip screw fixation for intertrochanteric fractures from January 2017 to January 2022. The clinical evaluation was done using Harris hip score. The radiological outcomes measured were subsidence, level of osteointegration, stem-canal fill ratio and heterotopic bone formation. The complications were noted postoperatively and during the follow-up. RESULTS: The mean follow-up at the end of the study was 27.8 months (range, 14-72 months). There was a significant improvement in the Harris hip score over serial follow-ups (p < 0.001), but after 2 years, there was no statistically significant difference (p = 0.46). According to Engh's criteria, stable ingrowth was noted in 35 stems, fibrous stable ingrowth was noted in 4 stems and no patients had progressive subsidence and unstable stem. The mean stem-canal fill percentages were 91.8 ± 5.4% at the mid-stem and 80.3 ± 11.5% at the stem tip. Heterotopic ossification Brooker grade 2 was noted in 8 patients, and no patients had grade 3 or 4 heterotopic ossification. There were 7 (17.9%) intraoperative periprosthetic fractures, and greater trochanteric avulsion was noted in 2 patients in the follow-up. CONCLUSION: Conversion THA using monoblock tapered distal loading stems bypasses the calcar deficiency and gives stable fixation in failed fixation of intertrochanteric fractures. It gives good radiological outcome and significant improvement in the clinical outcomes compared to the preoperative disability. However, caution should be noted for risk of intraoperative periprosthetic fractures in this subgroup of patients.