In 1999 a statement of best practice in primary total hip replacement was approved by the Council of the British Orthopaedic Association (BOA) and by the British Association for Surgery of the Knee (BASK) to provide a basis for regional and national auditable standards: we have compared practice in the North West of England to this document to ascertain adherence to this guide to best practice. A direct comparison of data held on the North West Hip Arthroplasty Register for 2001/2002 and BASK/BOA guidelines was performed. 86 surgeons from 26 hospitals were included in the study. A mean of 93.3% of operations were performed in the surgeon’s usual theatre. All of these theatres had vertical laminar air flow systems. 42.2% of respondents routinely used exhaust suits. 68.1% of respondents routinely used impermeable disposable gowns. All surgeons use some form of anti-thromboembolic prophylaxis. 66.2% use a combination of both mechanical and chemical means. All surgeons used antibiotic prophylaxis. The most popular choice of antibiotic was a cephalosporin. 93.7% of surgeons routinely use antibiotic-loaded cement. The PFC and Kinemax prostheses were the most commonly used pros-theses. Interestingly, 97.7% of all first choice implants were cemented. Only 2 surgeons used uncemented TKR. 69.8% of surgeons used a posterior cruciate retaining design. A midline longitudinal skin incision is used by 87.2% of surgeons, a medial longitudinal skin incision by 7.0% and a lateral longitudinal skin incision by 5.8% 0f surgeons. A medial parapatellar capsular incision is preferred by 91.9% with the remainder using mid vastus or trivector retaining capsulotomy. Closure of capsulotomies is performed in flexion by 65.1% and in extension by 34.9%. In patients with osteoarthritis 38.4% routinely resurfaced the patella, 34.9% never resurfaced the patella and 26.7% selectively resurfaced. This was in direct contrast to practice for patients with rheumatoid arthritis in whom 66.3% routinely resurfaced the patella, 22.1% never resurfaced the patella and 11.6% selectively resurfaced. This study has demonstrated considerable variation of practice in hip arthroplasty across the North West region and significant divergence from the BASK/BOA statement of best practice. The introduction of a properly funded national arthroplasty register will surely help to clarify the effect of such diverse practice on patient outcome.
Restoration of the mechanical axis is thought to be a critical factor in determining the outcome of knee replacement surgery. There is strong theoretical evidence that reproduction of this axis improves mechanical loading and hence longevity of the implant. Per operative use alignment jigs help to determine the bony cuts. Studies have shown large margins of error using the standard jigs. On this basis computer navigation systems are being introduced. No study has shown conclusively that accurately reproducing the mechanical axis of the lower limb improves survivorship of the implant. Prior to investing in these systems we felt it would be prudent to investigate how critical reproduction of the mechanical axis was in the primary total knee replacement. We assessed 100 primary total knee replacements performed in 1990. All case notes were reviewed looking for basic demographics, pathology, and clinical outcome. All cases had a long leg þlm weight bearing alignment þlm taken post operatively. These were digitised and then analysed using CAD software. From this the mechanical axis calculated. Using this data the patients were divided into two groups. The þrst were within 3 degrees varus/valgus of the mechanical axis. The second were outside this range. These two groups were then correlated to clinical outcome. Our results suggest that accurate reproduction of the mechanical axis improves clinical outcome and survi-vorship of the implant. Our data would support the use of intra operative computer navigation systems
The aim of this study was to ascertain if a correlation exists between the indication for revision and the clinical outcome in revision total knee replacement.
Sixteen per cent of patients revised for aseptic loosening were non-committal or disappointed with the outcome in comparison with 33.3% revised for implant failure, 21.4% revised for instability, 62.5% revised for pain and 71.4% revised for infection.
It is usually assumed that there is a correlation between the number of previous operations and the clinical outcome of revision knee arthroplasty though it has not been studied and published. We reviewed our series of 81 revision knee arthroplasty patients to ascertain if a correlation exists. All patients had a semi-constrained prosthesis implanted.
The clinical results of cemented hip arthroplasty in patients with DDH are excellent in terms of pain relief and implant longevity. The survivorship of the femoral stem in young patients less than 40 years of age is 97% at ten years and falls to 89% at 25 years. In comparison, survivorship of the acetabular component is 97% at ten years but falls to 58% at 25 years. The excellent survivorship of the femoral stem can be explained by a favourable canal flair index, competent cancellous bone, and secure fixation with acrylic cement. The inferior results of the acetabular component are explained by the distorted pelvic anatomy and lack of bone support for the acetabular component. We continue to recommend cemented hip arthroplasty in this cohort of patients. Our current practice is to use fourth generation cementing techniques and to employ autografting of the acetabulum to address some of the anatomical deficiencies of the original anatomy.
Preoperatively, 16 patients were wheelchair bound and using a frame as a walking aid and 10 used two crutches for ambulation. 5 patients needed plastic surgical input and 5 needed a whiteside’s osteotomy for exposure. Previous surgery on the knee: 2 patients – 1 surgery 13 patients – 2 surgeries 8 patients – 3 surgeries 5 patients – 4 surgeries 2 patients – more than 4 surgeries In the latest review, excluding the deceased patients, there were 24 patients (89%) regarded as having satisfactory and 3 patients (11%) unsatisfactory results. 89% of the patients were subjectively satisfied with the operation, mostly because of a stable, mobile knee with minimal pain, in comparison to their pre-operative debilitating condition.
Post operative blood salvage and autologous blood transfusion have been used though the financial implications of their use has not been assessed in the UK.
Mean blood loss (non-autologous system) – 778mls Mean blood loss ( autologous system) – 633mls Mean autologous blood reinfused – 360mls - (autologous drainage system) Mean homologous blood transfused – 179mls - autologous drainage system) Mean homologous blood transfused – 590mls - (non autologous drainage system) Total cost for use of autologous drainage system and associated transfusion – 6,226.00 Total cost for use of non-autologous drainage system and associated transfusion – 8,346.00
We report the long-term outcome of 218 Charnley low-friction arthroplasties in 141 patients who were 40 years old or younger at the time of surgery. The minimum follow-up was ten years with a mean of 16 years. The probability of the femoral component surviving 20 years was 86% and of the acetabular component, 84%. The chance that both components would survive for this period was 75%. The pathological diagnosis significantly influenced implant survival. In rheumatoid patients the probability of both components surviving at 20 years was 96% compared with 51% in patients with osteoarthritis. Clinical assessment of 103 patients (166 hips) in whom the arthroplasty was still functioning showed that 94% of hips had minimal pain or none. We conclude that in young patients cemented total hip replacement is a good procedure for those with rheumatoid arthritis but that the results are much less reliable in those with osteoarthritis.
A computer-based image analysis system has been developed as a research tool in total hip replacement. The system has been programmed to take multiple measurements from coronal plane radiographs. Poor quality radiographic images can be enhanced and standardised. The measurements which can be obtained include stem subsidence, cup migration, cup wear, and stem loosening. Reproducibility and accuracy were +/- 0.01 mm and +/- 0.5 mm respectively. The present application is in retrospective research, but prospective monitoring of radiographs is planned.