Hip Instability Leading to Metallosis, Polyethylene Wear, and Failure of an Oxinium Femoral Head: A Case Report and Review of Literature

Oxinium is a zirconium metal alloy with an oxidized (ceramicized) surface that aims to mimic the superior wear properties of a ceramic femoral head while maintaining the high strength of metal-bearing surfaces. There are several reports that illustrate the wear and/or failure of Oxinium femoral heads following abnormal head contact with metal cup, with only a few studies reporting on the occurrence of metallosis. We present a case of metallosis and failure of Oxinium femoral head following two incidents of hip instability and one closed reduction. Successful revision was performed with cemented cup and metal femoral head, with 68 months of follow-up. We aimed to highlight the importance of achieving stable and well-oriented hip components when using Oxinium-bearing surfaces and to present a short literature review regarding the wear of oxidized zirconium-bearing surfaces in hip arthroplasty.

Femoral Revision Total Hip Arthroplasty Performed through the Interval of the Direct Anterior Approach

Background: we report the clinical outcomes for femoral revision total hip replacement (THR) using the Direct Anterior Approach (DAA) interval. Methods: 149 patients (165 hips) with a mean age of 68.9 years (range, 33.2–91.0 years) and a mean follow-up of 4.2 years (1.1–8.9 years) were included. The indication for revision surgery was aseptic stem loosening in 131 (79.4%) hips, periprosthetic fracture in 29 (17.6%) hips, revision for stem malalignment in one (0.6%) hip, and prosthetic failure in four (2.4%) hips. Results: an endofemoral approach was used for 156 hips, and a Wagner transfemoral osteotomy was used for nine hips. An additional cup revision was done in 52 hips (uncemented cup: n = 29; cemented cup: n = 21; acetabular cage: n = 2). The overall complication rate was 14.5% (24 complications). Ten patients (10 hips) were revised (8 cups, 2 liners, 2 stems) with an average time to revision of 6 months (range, 3–23 months). The median preoperative Western Ontario McMasters Osteoarthritis Score (WOMAC) score was 52.5 (Inter Quartile Range (IQR): 33.3), which improved to 27.2 (IQR: 30) postoperatively (p < 0.01). Conclusion: use of the DAA achieved similar results when compared with other surgical approaches in terms of clinical outcomes and complications, including dislocation rate. These results suggest that femoral revision using the DAA interval can be a safe and reliable procedure.

Two-year results of the Moovis trapeziometacarpal joint arthroplasty with focus on early complications

In this prospective study, we aimed to analyse the early results of 200 consecutive total trapeziometacarpal joint arthroplasties using the Moovis cup, a new generation, dual-mobility, uncemented conical cup, with special focus on early complications. At the 24-month follow-up, we found clinically relevant improvement of function and comfort. Among intraoperative complications were nine intraoperative trapezial fractures, which were treated by screw osteosynthesis; prolonged immobilization; and conversion to cemented cup fixation or primary or secondary trapeziectomy. One was left untreated as the loose cup did not cause notable symptoms. There were three implants with polyethylene wear and two with liner dislocation. We conclude that early outcomes of this new-generation implant are favourable, but its surgery is challenging and associated with important intraoperative and early postoperative complications related to the learning curve. Attentive reaming of the trapezium and careful cup impaction are crucial steps to avoid trapezial fracture and early cup failure. Level of evidence: II

Dual-mobility bearings for patients with abductor-trochanteric complex insufficiency

Introduction: The purpose of this study was to summarise the performance of dual-mobility cup systems for revision total hip arthroplasty in patients with abductor-trochanteric complex deficiency. Methods: We prospectively followed 17 patients (20 hips) with a mean age of 64.5 years (range 33-89 years) who underwent acetabular reconstruction with dual-mobility cups for aseptic loosening in 12 hips, infection treatment as second or single stage in 6 hips, and instability in 2 hips. All of the patients had abductor insufficiency. We evaluated the clinical Harris Hip scores (HHS) and radiographs for migration, loosening, and osteolysis. The survival of the components was calculated according to Kaplan-Meier survivorship analysis, and failure was defined as any dislocation, acetabular component or total hip revision for any reason. Results: The mean duration of follow-up was 38.1 months (range 24-98 months). There were 2 (12.5%) revisions for cemented cup migration after 11 months and 19 months respectively. There were no dislocations. At the last follow-up, the mean HHS increased from 42 points preoperatively to 86 points. The cumulative survival rate of the dual-mobility cup system was 93% (95% confidence interval 88-98.7%) at 5 years, with any revision as the end point. Conclusion: Dual-mobility cups may provide excellent stability in patients with abductor-trochanteric complex insufficiency.

The Corail Stem as a Reverse Hybrid – Survivorship and X-Ray Analysis at 10 Years

Background The use of a cemented cup together with an uncemented stem in total hip arthroplasty (THA) has become popular in Norway and Sweden during the last decade. The results of this prosthetic concept, reverse hybrid THA have been sparsely described. We report our experience of reverse hybrid THA, using the Elite plus polyethylene cemented cup together with the Corail fully hydroxyapatite-coated uncemented stem and a 28-mm alumina ceramic head. Patients and methods 132 consecutive reverse hybrid hip arthroplasties were performed from January 2000 to December 2003 in 126 patients with a mean age of 54.3 years (28-65). All patients were routinely reviewed at 3 months, 1, 5, 7 and 10 years postoperatively. At each follow-up patients were seen either by a consultant orthopaedic surgeon or a senior trainee. Anteroposterior pelvic and lateral x-rays of the hip were taken at each visit. To estimate the survival of the THAs we used the Kaplan-Meier method with 95% confidence interval (CI). Logistic regression analysis was performed to determine which factors affected the presence of radiolucency around the femoral stem. Results The mean follow-up was 11.1 years (9.0-14.2). 1 patient was lost to follow-up, and 7 patients were deceased at the time of 10-year follow up. At 10 years 7 patients have had further surgery. 5 for infection, 1 periprosthetic femoral fracture and 1 heterotopic bone formation. All stems were classified as well fixed. 2 cups were defined as loose at 10 years. 1 patient is scheduled for revision the other refused revision. The clinical outcome and radiological findings were assessed in 123 hips. The mean Harris Hip Score was 94 (35-100) at 10 years and the mean WOMAC score was 89 (30.2-100). Conclusions We report good results with respect to clinical outcome and survival of the reverse hybrid concept in patients younger than 65. A successful outcome depends on meticulous preoperative planning, use of modern cementing techniques in the acetabulum and experience in implanting an uncemented stem.