Introduction: Tibial augments are required to replace bone loss in the proximal tibia during revision total knee replacement and can be either a rectangular ‘block’ shape or an angled ‘wedge’ shape.

Purpose of study: We have identified a high failure rate with the ‘wedge’ shape currently used in the Co-ordinate (DePuy) revision knee system.

Methods: We report a series of revision total knee replacement procedures performed using the Co-ordinate system. All revision ‘angled’ tibial wedge implants were selected from our prospective database containing follow up records for knee replacements. Patients underwent clinical and radiological review at three months following the procedure, on the anniversary of surgery and then on a yearly basis. Those with fewer than 12 months follow-up were excluded.

Results: Between December 1993 and February 2006, a total of 34 patients (19 female, 15 male) required revision knee arthroplasty with an ‘angled’ wedged tibial augment. Mean age at surgery was 59.3 years (range 46–93). Five cases were excluded due to absence of follow-up (four requiring further surgery for infection and one due to unrelated medical complications). Of the remaining 29 cases, 16 (55.2%) had no problems with the tibial implant, while 13 (44.8%) exhibited radiological changes on review. Tibial implant migration was seen in 5 cases (17.2%), all within three years of surgery. One of these has needed further revision surgery and the other four are expected to need revision in the future. Seven (24.1%) were found to have a tibial radiolucent zone, which was progressive in four cases. There was one case of stem dissociation.

Conclusion: ‘Angled’ tibial wedge implants are associated with a high rate of implant migration and loosening, presumably due to the effect of shear forces. Use of these implants should be reserved for low demand patients.

Aseptic loosening due to periprosthetic bone loss is a major cause of implant failure after total hip arthroplasty (THA). Interleukin 1-B (IL-1B) is thought to play a role in aseptic loosening by stimulating the activity of osteoclasts, the main bone resorbing cell type. A restriction fragment length polymorphism due to a C/T single base variation at +3954 in exon 5 of the IL-1B gene has been associated with differences in susceptibility to chronic periodontitis, a condition associated with bone loss. In this study we tested whether carriage of the C and T alleles at this site resulted in differential risk of aseptic loosening in 481 Caucasians (214 failed versus 267 radiologically intact implants) at 11.7± 4.1 years following primary cemented THA for osteoarthritis. Genomic DNA extracted from peripheral blood was genotyped using the Taqman 5′ nuclease method. Carriage rates were calculated and analysed using the 2 test.

In the intact implant group the frequency of the T allele was 0.253. The distribution of the C and T alleles was 147:105:15 (CC:CT:TT, respectively). In the failed implant group the frequency of the T allele was 0.241). The distribution of the C and T alleles was 124:77:13. The carriage rate of the T alleles in each group was 44.9% and 42.1%, respectively (odds-ratio P> 0.05). The genotype frequencies were in Hardy-Weinberg equilibrium for both intact and loose implant populations (Chi-squared P> 0.05).

Using the multivariate Cox proportional hazards model significant risk factors for loosening of both implant components included gender and age at THA (P< 0.05). However, carriage of the +3954 allele was not a significant independent risk factor for aseptic loosening (P> 0.05). Our data suggests that the IL-1B gene restriction fragment length polymorphism at +3954 does not influence the risk of aseptic loosening after THA.

Objective: To compare the results of MRI Gadolinium Arthrograms and hip arthroscopy in patients with hip pain.

Design: Retrospective analysis

Setting: St. James University Hospital, Leeds

Participants: 15 patients (10 females and 5males) underwent hip arthroscopy between 1999 and 2002.The procedure was performed by a single surgeon. The mean age of the patients was 39 (Range 24–74).

Outcome Measures: A review of the findings of both the MRI and arthroscopy were undertaken. Attention was paid to the both the specificity and sensitivity of the MRI diagnosis when compared to the findings at arthroscopy.

Results: All 15 patients underwent MRI Arthrograms with intra-articular gadolinium prior to arthroscopy. The time that elapsed between radiological evaluation and surgery was a mean of 10 months (Range 7–15).During this time there had been no significant change in any of the patients’ clinical symptoms.

Of the 15 scans performed only 10 were found to provide an accurate diagnosis confirmed at the time of surgery, The presence of osteochondral defects, loose bodies, synovitis and AVN were all correctly identified.

Of the remaining five cases, two labral injuries were identified radiologically, but arthroscopy proved to be normal. MRI was also found to be particularly inaccurate when assessing for articular cartilage defects, failing to demonstrate moderate to advanced changes in three cases, later confirmed at surgery.

Discussion: MRI is the non-invasive investigation of choice for the assessment of both intra and extra articular hip pathology. However our results show that limitations do exist with the sensitivity and specificity of this investigation. Previous studies (Edwards et al, Villar et al) have demonstrated similar findings .The interpretation of MRI Arthrograms should therefore be carefully considered when establishing a diagnosis for hip pain.

Abstract We have prospectively analysed a single-surgeon series of 35 consecutive revision THRs with AAOS bone loss grade II–III, requiring morcelised allograft (ethylene oxide sterilised) for acetabular defects. Patients have been followed up for a minimum of 5 years. Although the results are encouraging, we are observing migration patterns in some cases.

Method Twenty-one patients were eligible for final analysis (follow-up for at least 5 years, range 5 to 10 years). Follow-up has consisted of clinical assessment (Charnley activity, pain, function, satisfaction) and a radiographic assessment (AP X-ray) of the replacement hip. Our study end-points are 1) prosthesis revision and, 2) acetabular cup migration at last follow-up.

Results There were 6 deaths with less than 5 years follow-up (unrelated causes) and 2 cases have been lost to subsequent follow-up. Two cases had deep infection (revised to a girdlestones procedure at 9 months and 2 years respectively) and there were no early dislocations. One case underwent further revision at 4 years follow-up due to symptomatic (superior) cup migration and three cases are awaiting imminent out-patient assessment. Twenty-one cases have had a mean follow-up of 5.83 years. Eight cases (23%) have shown no cup migration. Five have shown only late stage migration, 4 cases have shown both initial and then late migration whilst 3 cases have shown only intermediate migration followed by stability. One case has shown progressive migration throughout follow-up. All 13 cases (37%) exhibiting migration are still asymptomatic.

Conclusion Our results show that use of morcelised acetabular allograft for revision hip surgery with deficient medial and superior acetabular wall is a useful surgical procedure. Our results over a minimum of 5 years follow-up are comparable to others in this field. However, the relatively high number of revision cases from our data which have shown, as yet, asymptomatic cup migration causes concern for future management of these patients. It is imperative that all such cases have regular (annual) indefinite follow-up. We are concerned that further cases may present with acetabular cup migration in view of our results.

The purpose of this study was to assess if the use of sterile stockings in lower limb surgery results in the contamination of the operative site with skin commensals from unprepared skin.

Twenty-five consecutive patients under going elective single knee arthroscopy were included in our study. All patients were operated on in the same laminar airflow theatre, by the same surgeon using the same method of skin preparation and operative technique.

Skin swabs were taken from each patient’s foot prior to the commencement of surgery. The limb was then prepared as follows;

An unscrubbed assistant holds up the leg, the leg is then prepared with betadine, by the surgeon from ankle to thigh, sparing the foot.

Two samples were also cut from the cuff of the stocking, one prior to its use to act as a control and the other once it had been unrolled up the leg. The three samples were then sent to microbiology. The swabs were plated out on blood (x2), chocolate and Maconkey agar. One blood plate was incubated anaerobically at 37°c and the others in air at the same temperature. The stocking sample was cultured in nutrient broth. After 48 hours isolates were identified using standard techniques.

The results showed that none of the stocking samples yielded positive microbiology, however all of the foot swab samples did. They all grew coagulase negative Staphylococcus (CNS), five also grew conforms and one grew Pseudomonas, as well.

We can conclude from this, that this method of skin preparation using the sterile stocking is safe. It appears in this study, that the action of unrolling the stocking over the unprepared foot and then up the prepared leg does not contaminate the prepared operative site with commensals from the foot. However concern is raised by the high incidence of CNS on the foot, and may be a source of potential infection.

Tumour necrosis factor-α (TNF) is thought to play a role in aseptic loosening, the major cause of implant failure after total hip arthroplasty (THA). Natural sequence variations at –238 and –308 in the promoter region of the TNF gene are associated with differences in the susceptibility and severity of several TNF-mediated diseases. We tested whether carriage of the [less common] ‘A’ allele at –238 and –308 are associated with aseptic loosening after THA.

481 Caucasians (214 with failed implants versus 267 with radiologically intact implants) were recruited 11.7± 4.1 years after cemented THA for osteoarthritis. Genomic DNA was extracted from peripheral blood and genotyped for the –238 and –308 polymorphisms using the Taqman® 5′ nuclease method. 500 subjects from the local population were also genotyped using Taqman® to establish the background prevalence of the ‘A’ allele at each site.

The carriage rate of –238A was 8.8% in the background population and 10.9% in the THA controls (P> 0.05). –238A carriage in the loosening group was 17.3% (odds ratio 1.72, 95% confidence interval 1.02 to 2.90). Carriage was highest (20.5%) in subjects with loosening of both the femoral and pelvic implant components (odds ratio 2.12; 1.17 to 3.83). The association of –238A with aseptic loosening was independent of age, sex, and amount of implant wear (Cox hazard ratio 1.49 (1.04 to 2.13; P=0.03)). Carriage of –308A was not associated with aseptic loosening.

Genetic, as well as environmental factors, influence implant failure after THA. Whether the –238 polymorphism causes the biological change that predisposes to loosening, or is in linkage disequilibrium with such a locus, is not yet known.

The aim of revision hip arthroplasty for infection is to eradicate infection and restore function. There is, in current literature, little evidence to suggest an optimal time interval between first (excision) and second (reconstruction) stage procedures in revision hip arthroplasty.

Our aim was to assess the difference in outcome, in terms of patient pain, function and satisfaction, in relation to the time interval between surgeries.

A prospective analysis was made of 22 consecutive patients who underwent two-stage revision total hip replacement between 1992 and 2001. There were 12 male and 10 female patients. The mean age at the time of revision surgery was 63.5 years (range 35–83 years). The indication for surgery was infection in all cases. Patients were subdivided into two groups according to the time interval between first and second stages : Group 1 – time interval 6 months or less; Group 2 – time interval greater than 1 year. Outcome was assessed at 1 year post-operatively using change in pain and function scores and patient satisfaction scores.

Pre-operative pain and function scores were similar in the two Groups. Both Groups reported a similar improvement in pain at 1 year post-operatively. The patients in Group 1 also showed an improvement in function score, however, the patients in Group 2 showed no improvement in function. All patients felt the operation to be worthwhile as reflected in the patient satisfaction scores.

The results suggest that good improvements in pain can be achieved after short and longer time intervals. A longer time interval may well be associated with a poorer outcome in terms of restoring function.