Aims

Use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years due to proposed benefits, including a lower risk of dislocation and improved early functional recovery. This study investigates the dislocation rate in a non-selective, consecutive cohort undergoing THA via the DAA without any exclusion or bias in patient selection based on habitus, deformity, age, sex, or fixation method.

A common situation presenting to the orthopaedic surgeon today is a worn acetabular liner with substantial acetabular and pelvic osteolysis. The surgeon has many options for dealing with osteolytic defects. These include allograft, calcium based substitutes, demineralised bone matrix, or combinations of these options with or without addition of platelet rich plasma. To date there are no clinical studies to determine the efficacy of using bone-stimulating materials in osteolytic defects at the time of revision surgery and there are surprisingly few studies demonstrating the clinical efficacy of these treatment options. Even when radiographs appear to demonstrate incorporation of graft material CT studies have shown that incorporation is incomplete. The surgeon, in choosing a graft material for a surgical procedure must take into account the efficacy, safety, cost and convenience of that material.

Cite this article: Bone Joint J 2014;96-B (11 Suppl A):70–2.

Background

Hip resurfacing has resurged in the last decade due to a renewed interest in metal on metal bearing. One of the proposed advantages is ease of revision of the femoral component. Short term functional results after femoral revision are similar to those after conventional total hip replacement. Survival and function after revision of the acetabular component only or of both components have not been reported. We aimed to assess hip function and implant survival after revision of the acetabular component for failed Birmingham hip resurfacing (BHR).

The removal of all prosthetic material and a two-stage revision procedure is the established standard management of an infected total hip replacement (THR). However, the removal of well-fixed femoral cement is time-consuming and can result in significant loss of bone stock and femoral shaft perforation or fracture. We report our results of two-stage revision THR for treating infection, with retention of the original well-fixed femoral cement mantle in 15 patients, who were treated between 1989 and 2002. Following partial excision arthroplasty, patients received local and systemic antibiotics and underwent reconstruction and re-implantation at a second-stage procedure, when the infection had resolved.

The mean follow-up of these 15 patients was 82 months (60 to 192). Two patients had positive microbiology at the second stage and were treated with six weeks of appropriate antibiotics; one of these developed recurrent infection requiring further revision. Successful eradication of infection was achieved in the remaining 14 patients.

We conclude that when two-stage revision is used for the treatment of peri-prosthetic infection involving a THR, a well-fixed femoral cement mantle can be safely left in situ, without compromising the treatment of infection. Advantages of this technique include a shorter operating time, reduced loss of bone stock and a technically more straightforward second-stage procedure.

We report the use of porous metal acetabular revision shells in the treatment of contained bone loss. The outcomes of 53 patients with ≤ 50% acetabular bleeding host bone contact were compared with a control group of 49 patients with > 50% to 85% bleeding host bone contact. All patients were treated with the same type of trabecular metal acetabular revision shell. The mean age at revision was 62.4 years (42 to 80) and the mean follow-up of both groups was 72.4 months (60 to 102). Clinical, radiological and functional outcomes were assessed. There were four (7.5%) mechanical failures in the ≤ 50% host bone contact group and no failures in the > 50% host bone contact group (p = 0.068). Out of both groups combined there were four infections (3.9%) and five recurrent dislocations (4.9%) with a stable acetabular component construct that were revised to a constrained liner. Given the complexity of the reconstructive challenge, porous metal revision acetabular shells show acceptable failure rates at five to ten years’ follow-up in the setting of significant contained bone defects. This favourable outcome might be due to the improved initial stability achieved by a high coefficient of friction between the acetabular implant and the host bone, and the high porosity, which affords good bone ingrowth.

Introduction: Uncemented sockets have been used for revision with good results in the literature. Tantalum coated acetabular uncemented implant is the next generation implant. We used Tritanium (Stryker Corp. Kalamazoo, USA) for revision of acetabulum and present the early results. Aim: To determine early results of porous tantalum coated modular acetabular cups in revision hip arthroplasty. Patients and methods:41 acetabular revisions in 41 patients were performed using Tritanium acetabular uncemented sockets between March 2007 and March 2008. Posterior approach was used for all procedures. AAOS system for acetabular bone deficiency and Harris hip score for function was used for assessment. Results: Mean age of the patients was 67 yrs (range 45–88). 95% of cups were fixed with screws for initial stability. AAOS classification showed there were 17 % Type 1, 49 % Type 2, 24% Type 3 and 5% Type 4 defects and 5 % had no defect. Bone graft was used to in 70% of patients, mostly autograft from the reamings. Mean Harris Hip Score improved from 68 pre-operatively to 84 at the last follow-up. Cup integration was seen in 93% patients. In two patients with pelvic discontinuity there was migration and in one loosening of the implant. One patient was treated for deep vein thrombosis and one patient for infection. Conclusion: Early results of tantalum coated acetabular socket are encouraging, in providing adequate initial stabilisation for biologic fixation in segmental, cavitatory and combined defects. Facility to use locking screws in multiple directions may help in addressing pelvic discontinuity

Introduction: Several techniques have been described for revision of acetabulum associated with severe superior bony defects. An Oblong cup inserted without bone cement has the advantage of restoration of the centre of hip rotation and maintenance of bone stock. The aim of this study was to analyse the medium-term results of acetabular revision using Oblong cup for severe superior bony defects. Methods: Thirty-five acetabular revisions using porous coated Oblong cups (S-Rom, Depuy) in 34 patients were performed by the senior author between 1998–2001. All patients were followed-up clinically and thirty-one hips were analysed radiologically for a mean duration of 39.6 months (range 18 to 60). The clinical assessment was performed using Harris hip score and subjective patient’s satisfaction. The acetabular defects were classified according to the method described by Paprosky et al. The position of the acetabular implant, restoration of the centre of hip rotation and the extent of osseo-integration of the acetabular shell were assessed in the post-operative radiographs. Results: The mean Harris hip score has improved from a preoperative value of 40.6 to 69.4 post-operatively. According to the Leprosy’s method, two acetabula were classified as type 2B, 12 as type 3A and 17 as 3B. The post-operative radiographs showed a mean abduction angle of the Oblong cups of 54.2 degrees (range 40–80). Osseointegration was achieved in 29(94%) of cups. Three cups showed early migration, of which two eventually stabilised and osseointegrated by 12 months. The centre of rotation of hip improved from a mean lateral migration of 8.3 mm and superior migration of 23.5 mm in the pre-operative radiographs to 2.8 mm and 4.3 mm respectively post-operatively. Discussion: Acetabular revision using porous coated oblong cup for severe superior acetabular defects provides satisfactory medium-term results with predictable restoration of hip centre of rotation

Introduction: The Spotorno cementless femoral stem relies on proximal press-fit at time of surgery and subsequent osseointegration for long-term fixation. The aim of the study is to assess the long-term survivorship and clinical outcome of the Spotorno stem used in primary hip replacement surgery in younger patients. Materials and Methods: 74 patients were identified who had undergone 90 THRs using the Spotorno CLS stem between January 1987 and May 1992. There was variation in the acetabular components used. 5 patients (6 hips) were lost to follow-up, leaving a study group of 84 hips. The patients were assessed using the Harris Hip Score and the Oxford Hip Score. Results: Mean age at operation was 40.1years (range 23–65years). Commonest diagnoses were primary osteoarthritis, developmental dysplasia of the hip and rheumatoid arthritis. Mean duration of follow-up was 12.25 years (range 8½ – 15yrs 3months). At most recent follow-up, the mean Oxford Hip Score was 23.8 and mean Harris Hip Score was 81. Taking revision for any cause as an end point, 19 hips from the initial group of 84 had undergone some form of revision surgery at most recent review. 15 of the 19 hips that failed had aseptic loosening of the acetabular component, which was the Mecring component, and underwent revision of acetabulum only. Four stems were revised, 2 for loosening and 2 for infection. 80 out of 84 of stems originally implanted remained intact at most recent review, which represents a stem survivorship of 95.2% at mean 12.25yrs follow-up when used in young patients. Conclusion: Our findings indicate excellent long-term survival of this titanium alloy stem when used in patients under 65years. We attribute this to stem design and the principle of proximal press-fit fixation. Careful consideration must be given to acetabular component selection in cementless total hip arthroplasty