Purpose of Study: To identify the functional outcome, quality of life and prosthesis survivorship in patients who have undergone the Avon patellofemoral arthroplasty at an independent centre.

Method and Results: Sixty-three patellofemoral arthroplasty (PFA) procedures were undertaken on 44 patients between May 1998 to May 2007. The primary and secondary outcome measures were knee function and quality of life, respectively. These outcomes were determined using the Oxford Knee Score (OKS) and EQ-5D and visual analogue score. Out of the forty-four patients 6 were deceased and 6 were lost to follow-up.

Therefore, thirty-two patients (50 PFAs) were included; nine males and 23 females.

Seventeen patients had bilateral PFA. The mean age of the patients was 65.8 years (SD 9.2). Follow-up averaged at 5.34years (range 2.1–10.2years) (SD2.64). The Oxford Knee Scores in this population showed a bimodal distribution. One group centred around 35 and the other around 60. The median Oxford knee score was 42.5 (IQR 34.25 to 54.25). Two sample t-test analysis of the population, divided as those above and below an OKS of 42, showed that follow-up time and age, did not differ between the groups (p=0.325, p=0.255 respectively). The quality of life outcome scores were significantly lower for bilateral compared to unilateral patients, with median scores of 50 and 72.5 respectively (p=0.03829). The cumulative survival at 5years for those with minimum 5 year follow-up (32 out of 50 PFA) was 100%. Three knees in total were revised. One patient developed bilateral tibiofemoral osteoarthritis, requiring revision to total knee replacement (TKA) at seven and 10 years. Another had persistent anterior knee pain and was converted to a TKA.

Conclusion: The Avon patellofemoral arthroplasty provides good functional outcome. The survivorship rate is promising although longer follow-up is required. Prudent patient selection is needed avoid high rates of revision to TKA.

Purpose of Study: To identify the functional outcome, quality of life and prosthesis survivorship in patients who have undergone the Avon patellofemoral arthroplasty at an independent centre.

Method and Results: Sixty-three patellofemoral arthroplasty (PFA) procedures were undertaken on 44 patients between May 1998 to May 2007. The primary and secondary outcome measures were knee function and quality of life, respectively. These outcomes were determined using the Oxford Knee Score (OKS) and EQ-5D and visual analogue score. Out of the forty-four patients 6 were deceased and 6 were lost to follow-up. Therefore, thirty-two patients (50 PFAs) were included; nine males and 23 females. Seventeen patients had bilateral PFA. The mean age of the patients was 65.8 years (SD 9.2). Follow-up averaged at 5.34years (range 2.1–10.2years) (SD2.64). The Oxford Knee Scores in this population showed a bimodal distribution. One group centred around 35 and the other around 60. The median Oxford knee score was 42.5 (IQR 34.25 to 54.25). Two sample t-test analysis of the population, divided as those above and below an OKS of 42, showed that follow-up time and age, did not differ between the groups (p=0.325, p=0.255 respectively). The quality of life outcome scores were significantly lower for bilateral compared to unilateral patients, with median scores of 50 and 72.5 respectively (p=0.03829). The cumulative survival at 5years for those with minimum 5 year follow-up (32 out of 50 PFA) was 100%. Three knees in total were revised. One patient developed bilateral tibiofemoral osteoarthritis, requiring revision to total knee replacement (TKA) at seven and 10 years. Another had persistent anterior knee pain and was converted to a TKA.

Conclusion: The Avon patellofemoral arthroplasty provides good functional outcome. The survivorship rate is promising although longer follow-up is required. Prudent patient selection is needed avoid high rates of revision to TKA.

In a personal series of over 560 hip resurfacing operations performed since 1995, 35 hips have required revision operations.

Only one has been for infection, a single stage revision was performed at 33 months following primary implantation, and the revised hip is still functioning well over 7 years later.

There have been five femoral neck fractures, all became symptomatic within 100 days of surgery. The first four were revised to cemented stems with large modular heads, the fifth was revised to an uncemented stem with large head. The first of these patients developed aseptic loosening at the bone/cement interface, and was revised at 18 months to a cemented Exeter stem with ceramic head and uncemented socket with plastic liner. At 8 years, the hip continues to function well clinically with no radiological signs of loosening.

The remaining four patients have all had satisfactory results at a mean follow up of 69.3 months (range 52 – 96 months)

Ten hips have required revision operations for femoral head loosening or collapse. The mean time after initial surgery was 54.6 months (range 23 – 107 months). In every case, the original socket was preserved and a stem with large modular head was used. The first two were using cemented stem and are still functioning well at 52 and 69 months. The next was with a Trifit uncemented stem, and remains satisfactory at 36 months. The remaining five have all been revised with a Plus Orthopaedics Zweymuller stem. The mean follow up is 13.8 months (range 5 – 33 months) and all are currently satisfactory.

There have been 18 sockets which required revision operations for loosening. The three earliest of these underwent revision surgery at 16, 17 and 27 months, and probably represent sockets which were inadequately seated at the time of implantation and failed to osseointegrate. This is evident on the initial post op radiographs in two patients. The third patient had unexplained discomfort in the hip from the outset, and eventually the hip was explored; at operation the socket was found to be loose after the hip had been opened and the head excised. Only one other patient required the head to be removed; the bone loss in the socket around the loose acetabular socket required revision with a larger socket than would allow the head to be preserved.

There was a cluster of five sockets which were revised between 50 and 57 months, the remaining five sockets were revised between 78 and 98 months. The timing of these failures suggests different modes of failure.

One patient had a revision with a dysplasia socket but no graft and 12 months later had clinical and radiological signs of loosening, but the symptoms settled before surgery was performed.

One patient developed a post operative infection and the implants were removed.

The remaining patients have a mean follow up of 36.5 months (range 8 – 61 months), with no signs of failure of the revised socket or the original femoral component.

Between May 1998 and May 2007 we carried out 50 Avon patellofemoral joint replacements in 32 patients with isolated patellofemoral osteoarthritis.

There were no revisions in the first five years, giving a cumulative survival of 100% for those with a minimum follow-up of five years. The mean follow-up was 5.3 years (2.1 to 10.2). The median Oxford knee score was 30.5 (interquartile range 22.25 to 42.25). In patients with bilateral replacements the median Euroqol General health score was 50 which was significantly lower than that of 75 in those with a unilateral replacement (p = 0.047). The main complication was progression of disease, which was identified radiologically in 11 knees (22%). This highlights the need for accurate selection of patients. Our findings suggest that the Avon prosthesis survives well and gives a satisfactory functional outcome in the medium term.

We have developed a novel method of calculating the radiological magnification of the hip using two separate radio-opaque markers. We recruited 74 patients undergoing radiological assessment following total hip replacement. Both the new double marker and a conventional single marker were used by the radiographer at the time of x-ray. The predicted magnification according to each marker was calculated, as was the true radiological magnification of the components. The correlation between true and predicted magnification was good using the double marker (r = 0.90, n = 74, p < 0.001), but only moderate for the single marker (r = 0.50, n = 63, p < 0.001). The median error was significantly less for the double marker than for the single (1.1% vs 4.8%, p < 0.001). The double marker method demonstrated excellent validity (intraclass correlation coefficient = 0.89), in contrast to the single marker (0.32).

The double marker method appears to be superior to the single marker method when used in the clinical environment.

We used Laser Doppler flowmetry to measure the effect on the blood flow to the femoral head/neck junction of two surgical approaches during resurfacing arthroplasty. We studied 24 hips undergoing resurfacing arthroplasty for osteoarthritis. Of these, 12 had a posterior approach and 12 a trochanteric flip approach. A Laser probe was placed under radiological control in the superolateral part of the femoral head/neck junction. The Doppler flux was measured at stages of the operation and compared with the initial flux. In both groups the main fall in blood flow occurred during the initial exposure and capsulotomy of the hip joint.

There was a greater reduction in blood flow with the posterior (40%) than with the trochanteric flip approach (11%).

Aims: To study clinical and radiological outcome of acetabular revision in THR with porous, hydroxyapatite-coated cups.

Methods: 50 acetabular revisions (48 patients) operated by single surgeon were reviewed. Uncemented, hydroxyapatite coated cup (Mallory/Head, Biomet) was used. Preoperative acetabular bone loss graded by Paprosky’s classification (grade 1: 12, grade 2a: 26, grade 2b: 8, 2c: 2, grade 3a: 2). Acetabulum alone was revised in 22 hips. Duration of follow up: 35 months (24–52). Clinical outcome assessment was done using Merle d’Aubigne and Postel score & QALY index questionnaire. Radiological assessment by standard X-rays taken at the latest review date. No case was lost to follow up.

Results: Merle d’Aubigne & Postel scores improved from 2.1, 2.7 and 2.4 (pre-operative) to 5.0, 4.3 and 4.5 (post-operative) respectively with significant improvement in QALYs scores. Radiological assessment showed no mechanical failures. Good trabecular formation between HA-coating and the bone seen in the majority. Non-progressive radiolucency < 1mm in 6 cases, superior migration > 2 mm in 3 cups where bone graft was used, and < 2mm migration in 9 cups was noted. 2 cases had rerevision for recurrent dislocation.

Conclusions: Hydroxyapatite coating on the implant may enhance bony ongrowth at bone-implant interface giving additional stability. Good midterm results obtained in our study using hydroxyapatite-coated components favour the use of this type of cup in acetabular revisions for moderate bone loss, but a long-term follow up is essential.

We performed a prospective, randomised controlled trial of the operative versus non-operative treatment of 42 displaced fractures of the distal femur in elderly patients.

Excellent or good results were achieved in 53% of the operated group and in 31% of the non-operated group. There were more complications in the latter, and the time to discharge was considerably longer.