METHODS: Retrospective review of 48 patients (48 hips) with follow-up duration of average 11.4 years (range, 6.1-21.4 years) was conducted. At each follow-up, Harris hip score was used to assess functional outcome, and radiographic acetabular component osteolysis was measured by DeLee and Charnley classification. Bone defects were assessed preoperatively and intraoperatively using American academy of orthopedic surgeons and Paprosky classification. The common modes of ARRH failures were evaluated. Bone consolidation, presence of heterotopic ossification, and complications such as infection and dislocation were recorded.
RESULTS: The bone defects were varied and included cavitary, segmental, and combined defects without any pelvic discontinuity. Mean Harris hip score improved from 52.6 points preoperatively to 82.0 points postoperatively. Nine acetabular revisions and 3 stem revisions (2 concurrent with acetabular revisions and 1 isolated stem revision) were performed. There were 5 infected cases and 1 patient with recurrent dislocation. The 11.4-year survival of revision THA with ARRH was 71% as the end point for acetabular revision surgery for any reason. The expected 15-year survival of revision THA with ARRH was 60%. The most common failure mode of ARRH was superomedial migration followed by lateral migration.
CONCLUSION: ARRH combined with bone grafting produces relatively good average long-term clinical results.
Materials and Methods: Forty eight hips with the conversion of bipolar HA to THA were followed up for an average 6.2 years (range 2.0-11.5 years). Twenty one hips had conversion surgery to THA using metal-on-metal articulation (28 or 32 mm head). Nine hips used ceramic-on-ceramic (28-40 mm) and eighteen hips used large head metal-on-metal bearing (>40 mm). Outcome was evaluated using Harris Hip Score (HHS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score. The radiographs were analyzed for evidence of osteolysis and/or loosening. The complications were evaluated, especially dislocation with different femoral head diameter.
Results: Average HHS significantly improved from 42 preoperatively to 86 postoperatively and the average WOMAC score also significantly improved from 47 to 22 postoperatively. Radiological evaluation showed all the femoral components were stable. There was one acetabular component loosening, which required revision 9 years after conversion to THA. One dislocation and one recurrent dislocation were recorded in isolated acetabular revision hip; whereas one dislocation, one recurrent dislocation, and one trochanteric nonunion occurred in the hips with revision of both components. All dislocations occurred in hips with a femoral head size of 28 mm (P = 0.052). The cup and femoral head interval length was the most significant factor contributing to dislocation (P = 0.013).
Conclusions: Conversion THA after failed bipolar HA offers a reliable pain relief and functional improvement. To prevent dislocation, it is highly recommended to use a larger diameter femoral head, especially where the cup size is big.
METHODS: Between 2006 and 2012, 22 patients underwent revision surgery using MoM bearing (28 mm femoral head in 18 hips and 32 mm in 4 hips) for ceramic bearing fracture and followed average 52.1 months. We assessed radiological parameter and functional outcome using Harris hip score (HHS) and WOMAC score. Also, serum cobalt (Co) and chromium (Cr) blood tests were performed and compared with the result obtained from age, sex- and follow-up duration-matched patients with MoM revision THA for failed polyethylene bearing.
RESULTS: The mean HHS improved from 60.6 preoperatively to 90.3 at final follow-up. There were no changes in cup position, progression of osteolytic lesions, and measurable wear of MoM bearing articulation at final follow-up radiographs. There was one case of recurrent dislocation after surgery, which was treated with greater trochanter distal advancement and one case of deep infection, which underwent two-stage revision. Mean serum Co level (1.7 vs. 1.4 μg/dl; p = 0.211) and Cr level (0.70 vs. 1.01 μg/dl; p = 0.327) showed no significant difference.
CONCLUSIONS: MoM articulation with liner cementation into the acetabular cup along with total synovectomy can be chosen in revision surgery for ceramic fracture with good midterm follow-up. However, the use of MoM bearing is indicated when the stem and metal shell can be retained and ceramic on ceramic or ceramic on polyethylene bearing cannot be selected. Also long-term outcome needs to be further evaluated.
Materials and Methods: This is a retrospective study of 179 patients who underwent cementless bipolar hemiarthroplasty during the 2011-2019 period at an orthopaedic and traumatology hospital. Data on the patient's demography, pre-operative American Society Anaesthesiologist (ASA) score, body mass index (BMI), canal flare index (CFI), Dorr classification, and stem alignment were obtained. The primary outcomes were post-operative femoral stem subsidence, post-operative pain, and functional outcome using Harris Hip Score (HHS). Statistical analysis was conducted to identify risk factors associated with the primary outcome.
Results: The mean femoral stem subsidence was 2.16 ±3.4 mm. The mean post-operative Visual Analog Score (VAS) on follow-up was 1.38 ± 1. Mean HHS on follow-up was 85.28±10.3. American Society Anaesthesiologist score 3 (p = 0.011, OR = 2.77) and varus alignment (p=0.039, OR = 6.963) were related to worse stem subsidence. Otherwise, neutral alignment (p = 0.045 and OR = 0.405) gave protection against femoral stem subsidence. The female gender (p = 0.014, OR 2.53) was associated with postoperative pain onset. Neutral alignment had significant relationship with functional outcomes (p = 0.01; OR 0.33).
Conclusion: A higher ASA score and varus stem alignment were related to a higher risk of femoral stem subsidence. Meanwhile, neutral stem alignment had a protective effect on the femoral stem subsidence and outcome.