Dual-mobility bearings in complex revision hip arthroplasty.

BACKGROUND: Revision total hip arthroplasty (rTHA) is associated with an increased dislocation risk. Dual-mobility (DM) bearings have been used to address this issue. Such constructs offer increased range of motion and enhanced stability whilst avoiding some issues associated with fully-constrained devices. DM bearings have been used in our unit since 2013. METHODS: All rTHA cases since 2013 were reviewed using the following criteria: (1) use of a DM bearing; (2) extensive soft tissue or bone loss resulting from ARMD, infection or multiple revisions, or requiring custom or megaprosthetic reconstruction; (3) minimum 2-month follow-up. RESULTS: 52 cases were identified with a median of 2 previous operations (range 1-6) and mean follow-up of 14 (2-41) months. The Novae-Stick component was used in 50 cases, the Avantage in 2 and the Trident MDM in 1 case. 19 required acetabular reconstruction using trabecular metal and four required custom acetabular components. 19 required femoral reconstruction with a proximal or total femoral replacement.Postoperatively, 8 patients (15.4%) sustained a dislocation at a mean of 1.6 (range 1-3) months. 3 (5.8%) requiring re-revision. 1 required excision arthroplasty and 2 a constrained liner, 1 of which went on to have further instability. There were no intraprosthetic dislocations. CONCLUSIONS: Dual-mobility components are a viable option in the complex rTHA setting. Early dislocations can occur but the rate of instability is acceptable in this high-risk group.

Clinical outcomes and dislocation rates after hip reconstruction using the Bioball system.

INTRODUCTION: Instability accounts for 1/3 of revision total hip arthroplasty (rTHA) performed in the UK. Removal of well-fixed femoral stems in rTHA is challenging with a risk of blood loss and iatrogenic damage to the femur. The Bioball universal adaptor (BUA), a modular head neck extension adaptor, provides a mechanism for optimisation of femoral offset, leg length and femoral anteversion. This can avoid the need for femoral stem revision in selected cases.The aim of this study is to present the clinical results and rate of instability following revision with this BUA at a minimum of 2 years follow-up. PATIENTS AND METHODS: A review of our prospectively collected database was performed. All patients treated with the Bioball device were included. Clinical and radiologic review were performed pre- and post-surgery. Specific enquiry for instability was made. The Oxford Hip Score (OHS), EuroQol (EQ-5D) score and WOMAC scores were calculated pre-and post-operatively. Complications were recorded. RESULTS: 32 rTHA procedures were performed using the Bioball device between 2013 and 2016. 4 patients did not wish to complete post-operative questionnaires. 2 patients (2/28, 7%) complained of recurrent dislocations following their rTHA procedure. 1 patient complained of instability but no dislocation. The median pre-operative EQ-5D was 0.195 (range -0.07-0.85), OHS was 20 (range 5-43) and WOMAC was 29.8 (range 15.5-52.3). The median EQ-5D was 0.85 (range 0.59-1), OHS was 39 (range 21-48) and WOMAC was 91.1 (range 44.5-99.2) at final follow-up. There were significant improvements in the EQ-5D (p = 0.0009), OHS (p = 0.0004) and WOMAC (p = 0.0001). CONCLUSION: The BUA is associated with significant functional improvement and relatively low dislocation rates in revision THA. It is a viable option for use in the revision setting.

Total hip arthroplasty with the MS-30 polished surface cemented stem: a single surgeon consecutive series study at 10 year follow-up.

The Morscher-Sportorno femoral stem is a stainless steel, straight, three-dimensionally tapered, collarless implant for cemented fixation in total hip replacement. The clinical and radiographic results of this implant at a minimum of 5-year follow-up have been extremely encouraging. However, the results at 10 years have yet to be reported. Therefore, we wished to establish the clinical performance and survival of the polished surface MS-30 femoral stem at a minimum of 10-year follow-up. We report the results at a minimum follow-up of 10 years of a single surgeon series of 55 total hip replacements with the polished surface MS-30 cemented femoral component in 48 consecutive patients aged between 50 and 64. The median period of observation was 12 years (inter-quartile range, 10-13). Six patients died with their implant in situ, and one patient was unable to attend for follow-up. All the remaining 41 patients with 47 total hip replacements were reviewed. All patients were assessed clinically with the use of the Oxford hip score, and radiographs taken at the latest follow-up were evaluated by an independent specialist hip surgeon. To date, none of the implants have been revised. The median Oxford hip score was 13 (inter-quartile range, 12-14). Radiologically, no stems had evidence of loosening on assessment by the Harris criteria, and only 4 hips (8.5 %) had osteolysis adjacent to the stem, mostly in Gruen zone 7. The results of the polished surface MS-30 femoral stem were satisfactory with survivorship at a minimum of 10 years of 100 %. These findings support the continued use of this femoral component.

The reconstruction of periprosthetic pelvic discontinuity.

The surgical techniques and outcomes of acetabular reconstruction for periprosthetic pelvic discontinuity cases are reported. The mean time to surgery for 9 patients with acute pelvic discontinuity was 16.3 days, with 8 patients (88%) having posterior column plating and a porous metal acetabular cup. No cases required revision surgery, with a mean follow-up of 34 months (range, 24-67 months). Of the 62 chronic pelvic discontinuity cases, 20 had an ilioischial cage, with a revision rate of 29%. There were 42 cup-cage reconstructions with an 8-year survivorship of 86.3%, with a mean follow-up of 35 months (range, 24-93 months). Stable reconstruction of chronic pelvic discontinuity was achievable by distraction using a cup-cage acetabular reconstruction; however, satisfactory stability of acute pelvic discontinuity was achieved with compression of the posterior column using screw augmentation of the acetabular shell supplemented by posterior column plating.

Removal of solidly fixed implants during revision hip and knee arthroplasty.

The removal of solidly fixed implants during revision hip and knee arthroplasty is a technically challenging procedure with the potential for a large amount of bone loss during component removal. This bone loss may compromise the subsequent reconstruction. Careful preoperative planning is essential before undertaking removal of solidly fixed implants. The surgeon should determine the type and size of the implants and be familiar with any specialized removal equipment that may be available. For both the hip and knee, extensive exposure is often necessary. Removal of a well-fixed femoral component often requires an extended trochanteric osteotomy. The most difficult component to remove from the knee is a well-fixed cementless patellar component. The primary goal in removing well-fixed components is to minimize loss of surrounding bone, which requires effective planning and often access to specialized tools and techniques.

The prevention of periprosthetic fractures of the femur during and after total hip arthroplasty.

The increasing prevalence of periprosthetic fractures of the femur associated with total hip arthroplasty (THA) is caused by several factors, including the increasing use of cementless prostheses in both primary and revision procedure, the rise in THAs in younger patients, who are more at risk of high-energy trauma, and the increasing longevity of elderly patients after THA. With approximately 200,000 THAs performed annually in North America, fracture prevention is extremely important for the individual patient and has a significant impact on the health care system.

Principles of management and results of treating the fractured femur during and after total hip arthroplasty.

The management of fractures of the femur during and after total hip arthroplasty can be difficult, and treatment can be fraught with complications. The ideal scenario would be one in which these fractures are prevented. It is important that the surgeon has a through understanding of the principles of managing these fractures and has access to a variety of fixation and prosthetic devices and allograft bone when necessary in order to provide the best treatment. Because periprosthetic fractures range from the very simple (requiring no surgical intervention) to the complex (requiring major revision), a classification system of these fractures aids in understanding both the principles of management and results of treatment.

Cementless revision for infection following total hip arthroplasty.

Eradication of chronic infection complicating total hip arthroplasty requires removal of all infected, devitalized and foreign tissue, including the arthroplasty components. Reimplantation into a sterile bed is the goal of treatment in most patients and successful reimplantation yields better functional results than excision arthroplasty. Reimplantation may be performed at the same stage as débridement as part of a single-stage procedure, using cemented components with antibiotic-loaded cement. Alternatively, a two-stage procedure may be performed so that the débridement and reimplantation are separated by a period of antibiotic delivery, both locally and systemically. The results of these treatment regimens and the rationale for cementless reconstruction at the second stage of a two-stage treatment protocol are important considerations in the treatment of periprosthetic infection.