This study reports the mid-term results of a large bearing hybrid metal on metal total hip replacement (MOMHTHR) in 199 hips (185 patients) with mean follow up of 62 months. Clinical, radiological, metal ion and retrieval analysis were performed.

Seventeen patients (8.6%) had undergone revision, and a further fourteen are awaiting surgery (defined in combination as failures). Twenty one (68%) failures were females. All revisions and ten (71%) awaiting revision were symptomatic. Twenty four failures (86%) showed progressive radiological changes.

Fourteen revision cases showed evidence of adverse reactions to metal debris (ARMD). The failure cohort had significantly higher whole blood cobalt ion levels (p=0.001), but no significant difference in cup size (p=0.77), inclination (p=0.38) or cup version (p=0.12) compared to the non revised cohort. Female gender was associated with increased risk of failure (p=0.04). Multifactorial analysis demonstrated isolated raised Co levels in the absence of symptoms or XR changes were not predictive of failure (p=0.675). However the presence of pain (p<0.001) and XR changes (p<0.001) in isolation were significant predictors of failure. Wear analysis (n=5) demonstrated increased wear at the trunnion/head interface (mean out of roundness measurements 34.5 microns (normal range 8–10 microns) with normal wear levels at the articulating surfaces. Macroscopically corrosion was evident at the proximal and distal stem surfaces. Cumulative survival rate, with revision for any reason was 92.4% (95%CI: 87.4–95.4) at 5 years. Including those awaiting surgery, the revision rate would be 15.1% with 89.6% (95% CI: 83.9–93.4). Cumulative survival at 5 years.

This MOMHTHR series has demonstrated unacceptable high failure rates with evidence of high wear at the head/trunnion interface and passive corrosion to the stem surface. Female gender was an independent risk factor of failure. Metal ion levels remain a useful aspect of the investigation work up but in isolation are not predictive of failure.

This study reports the mid-term results of a large bearing hybrid metal on metal total hip replacement (MOMHTHR) in 199 hips (185 patients) with mean follow up of 62 months. Clinical, radiological outcome, metal ion levels and retrieval analysis were performed.

Seventeen patients (8.6%) had undergone revision, and a further fourteen are awaiting surgery (defined in combination as failures). Twenty one (68%) failures were females. All revisions and ten (71%) of those awaiting revision were symptomatic. Twenty four failures (86%) showed progressive radiological changes.

Fourteen revision cases showed evidence of adverse reactions to metal debris (ARMD). The failure cohort had significantly higher whole blood cobalt ion levels (p=0.001), but no significant difference in cup size (p=0.77), inclination (p=0.38) or cup version (p=0.12) in comparison to the non revised cohort. Female gender was associated with an increased risk of failure (chi squared p=0.04). Multifactorial analysis demonstrated isolated raised Co levels in the absence of either symptoms or XR changes was not predictive of failure (p=0.675). However both the presence of pain (p<0.001) and XR changes (p<0.001) in isolation were both significant predictors of failure. Wear analysis (n=5) demonstrated increased wear at the trunnion/head interface (mean out of roundness measurements of 34.5 microns +/−13.3 (+/−2SD, normal range 8-10 microns) with normal levels of wear at the articulating surfaces. There was evidence of corrosion at the proximal and distal stem surfaces. The cumulative survival rate, with revision for any reason was 92.4% (95%CI: 87.4-95.4) at 5 years. Including those awaiting surgery, the revision rate would be 15.1% with cumulative survival at 5 years of 89.6% (95% CI: 83.9-93.4).

This MOMHTHR series has demonstrated unacceptable high failure rates with evidence of high wear at the head/trunnion interface and passive corrosion to the stem surface. This raises concern with the use of large heads on conventional 12/14 tapers. Female gender was an independent risk factor of failure. Metal ion levels remain a useful aspect of the investigation work up but in isolation are not predictive of failure.

With an increasing ageing population and a rise in the number of primary hip arthroplasty, peri-prosthetic fracture (PPF) reconstructive surgery is becoming more commonplace. The Swedish National Hip Registry reported that, in 2002, 5.1% of primary total hip replacements required revision due to PPF. Laboratory studies have indicated that age, bone quality and BMI all contribute to an increased risk of PPF. Osteolysis and aseptic loosening contribute to the formation of loosening zones as described by Gruen, with subsequent increased risk of fracture. The aim of the study was to identify significant risk factors for PPF in patients who have undergone primary total hip replacement (THR).

Logbooks of three Consultant hip surgeons were filtered for patients who had THR-PPF fixation subsequent to trauma. Risk factors evaluated included sex, age, bone density (Singhs index), loosening zones, Vancouver classification, prosthesis stem angle relative to the axis of the femur, and length of time from THR to fracture. A control group of uncomplicated primary THR patients was also scrutinised.

Forty-six PPF were identified representing 2.59% of THR workload. The male: female ratios in both groups were not significantly different (1:1.27 and 1:1.14 respectively). Average age of PPF was 72.1, which was significantly older than the control group (54.7, p>0.05). The commonest type of PPF was Vancouver type B. Whilst stem position in the AP plane was similar in both groups, in lateral views the PPF stem angle demonstrated significant antero-grade leg position compared to the non-PPF group (p.0.05). The PPF group demonstrated a greater number of loosening zones in pre-fracture radiographs compared to the control group (2.59 and 1.39 respectively, p>0.05)

Our workload from PPF reflects that seen in Europe. Age, stem position and the degree of stem loosening appear to contribute to the risk of a peri-prosthetic fracture.

It is established good practice that hip and knee replacements should have regular follow-up and for the past seven years at the North Hampshire Hospital a local joint register has been used for this purpose and we compare this with results of the Swedish and UK national and the Trent Regional registries.

Since March 1999, all primary and revision hip and knee arthroplasties performed at North Hampshire Hospital, Basingstoke have been prospectively recorded onto a database set up by one of the senior authors (JMB). Data from patients entered in the first five years of the register were analysed. All patients have at least one year clinical and radiological review then a minimum of yearly postal follow-up. 3266 operations (1524 hips and 1742 knees) were performed under the care of 13 consultants. Osteoarthritis was the most common primary diagnosis in over 75% of hips and knees. Our revision burden was 7.5% (10.2% hips and 3.5% knees). As of 31/12/2006 6.2% of patients had died and 5.5% were lost to follow-up.

Revision rates were 1.5% and 1.4% for primary total hip and knee replacements respectively.

Our data analysis of revisions and patello-femoral replacements has allowed us to change our practice following local audit which is ongoing. Oxford scores at 2 years had improved from a mean of 19 and 21 pre-operatively to 40 and 39 for primary hips and knees respectively. Our costs are estimated at approximately £35 per patient for their lifetime on the register.

Compared to other registries:

Our dataset is more complete and comprehensive

It is established good practice that joint replacements should have regular follow-up and for the past seven years at the North Hampshire Hospital a local joint register has been used for this purpose and we compare this with results of the Swedish and UK national registries.

Since March 1999, all primary and revision knee arthroplasties performed at North Hampshire Hospital, Basingstoke have been prospectively recorded onto a database set up by one of the senior authors (JMB). Data from patients entered in the first six years of the register were analysed. All patients have at least one year clinical and radiological review then a minimum of yearly postal follow-up.

As of 31/12/2006, 2854 knee replacement procedures had been performed under the care of 13 consultants. OA was the most common diagnosis in over 75% of knees. 5.2% of patients had died and 4.6% were lost to follow-up. Our revision burden was 3.5% and we had a revision rate of 1.4% for primary total knee replacements. Audit of data for revisions and patello-femoral replacements has enabled us to change our practices. Mean length of stay was 7.2 days for primary total knee arthroplasty versus 4.0 days for unicompartmental knee arthroplasty and 5.4 days for patellofemoral replacement and mean flexion at discharge was 88.4, 93.7 and 88.7 degrees respectively. WOMAC and Oxford scores at 2 years had improved from a mean of 52 and 21 pre-operatively to 74 and 39 respectively for primary total knee arthroplasty. Our costs are estimated at approximately £35 per patient for their lifetime on the register.

Compared to other registries:

Our dataset is more complete and comprehensive

Intra-operative infiltration of local anaesthetic into peri-operative tissue has become part of the protocol of many units worldwide. It is claimed that this reduces post operative pain and improves the speed of mobilisation thereby improving the comfort of the patient and decreasing the hospital stay.

In order to test the validity of this concept we conducted a prospective randomised controlled clinical trial of 100 patients undergoing primary total hip arthroplasty or hip resurfacing. All procedures were performed by one surgeon (Miss Muirhead-Allwood) using a posterior-lateral approach. Patients were randomised to receive 30ml of 0.5% Marcaine injected under direct vision at the time of closure or no injection (placebo).

Post-operatively patients in both groups received a standardised regime of intravenous infusion of diclofenac for 48 hours and ‘rescue’ intramuscular injections of morphine on demand.

Patients’ pain levels post-operatively were independently recorded using both a verbal rating score (VRS) and a visual analogue scale (VAS) at regular intervals for the first five post-operative days. Periodicity of requests for opiate analgesia was documented. Time taken to reach mobility ‘goals’ were also documented as was time taken to discharge and patient satisfaction with the whole process.

Our results show no significant difference in the two groups previously defined and we suggest that routine use of intracapsular local anaesthetic is not indicated in primary hip replacements and surface replacements provided an adequate post-operative pain regime is already in use.