Fourth Bristol Unicompartment Knee Arthritis Meeting

The 4th Bristol Unicompartment Arthritis Meeting was held on 7 May 2001. The meeting was attended by 72 delegates from across the country. This year the focus was on patello-femoral arthritis and replacement as opposed to osteotomy or unicompartment replacement (UKR). There was also a session highlighting the recent advancements in unicompartment knee replacement.

Without many signs of the aftermath of the welcome dinner the night before, the meeting got underway promptly. A brief welcome address by John Newman introduced the three morning symposia: the first on the epidemiology and radiology of arthritis; the second on the early treatment of patello-femoral disease; and the third on patello-femoral replacement (PFR).

Andrew Davis started the session by presenting the incidence of patello-femoral osteoarthritis (PFOA). In a review of 206 patients conducted at Norwich he found a 9% incidence of isolated PFOA. He found that the medial patellar facet involvement was more common in women. He also stressed the importance of patellar profile (skyline) views.

John Newman questioned whether adolescent anterior knee pain lead to patello-femoral arthritis. He quoted two recent studies which highlight the persistence of anterior knee pain many years after onset. His study was a retrospective analysis of 124 patients who had undergone isolated patello-femoral replacement (PFR). This postal questionnaire-based study aimed at picking up any history of adolescent patellar problems. This cohort of patients were age and sex-matched with patients undergoing UKR who according to selection criteria would have had a near normal patello-femoral joint. A significant difference was found in the incidence of adolescent patellar problems in the two groups. Patients (25%) in the PFR group had adolescent anterior knee pain or patellar instability as opposed to 6% in the control group.

He suggested that patients with lateral patellar facet involvement may have had patellar instability and the patients with medial facet involvement may have suffered with adolescent anterior knee pain. This theory lead to a lively discussion in which many members shared their experiences.

Paul O’Donnel (musculo-skeletal radiologist) described some interesting ways of measuring patellar subluxation using CT scan. Intricate analysis of articular cartilage based on MRI scans was also described. He also highlighted the need for MRI and CT scan analysis of knees with and without quadriceps contraction to assess patellar tracking.

The second symposium started with medical management of patello-femoral arthritis. John Kirwan (rheumatologist) presented his experience with Hylan GF 20 (intra-articular hyaluronidase injection). His study looking at early results (follow up 26 weeks) on use of this injection in patients (average age 55 years) with patello-femoral arthritis found a 30% sustained improvement in pain scores but with less improvement in disability scores. He found that most of the adverse reactions were early and in these cases a subsequent injection produced more severe reactions. He concluded that the effects of Hylan GF 20 on patello-femoral arthritis are similar to that on tibio-femoral arthritis and more sustained than cortico-steroid administration.

Andy Cobb described the use of local anaesthetic injection into the lateral retinaculum prior to lateral release as a prognostic indicator. In the 59 patients with early PFOA which he had followed for 1–5 years after lateral release he found an 80% improvement in pain but little improvement in patient satisfaction.

Chris Ackroyd also discussed realignment for early PFOA using arthroscopy to control tracking. He stressed the importance of superio-lateral portal for assessing the patello-femoral joint.

Andrew Smith described the Hasting and Eastbourne experience with PFR. His series consisting of three types of patello-femoral prosthesis (Lubinus, Cartier and LCS) had a 13% revision rate at 3 years average follow up. Bona Tauro presented the Bristol experience with Lubinus patello-femoral prostheses reporting an 8-year survivorship of 65% with revision as the end point. The main problems in these series were patellar maltracking and progression of arthritis.

Chris Ackroyd described the development of Avon patello-femoral replacement and highlighted some technical considerations and pointed out a few persistent problems that were being addressed. He reported a series of 133 patients who had a 98% survival rate at 2 years.

After lunch there was a short session on recent thoughts on the unicompartment tibio-femoral knee replacement in which John Newman noted that the Swedish series of medial compartment arthritis showed very low rates of progression of disease in the other compartment. He therefore questioned whether timely intervention could actually slow the natural progression of arthritis. He suggested this by demonstrating that only 14% of the knees showed progression of arthritis 10 years after medial UKR while 31% of a matched non-operatively treated group did so. A similar benefit was not seen after PFR.

The specificity and predictive value of MRI as a diagnostic tool for assessment of anterior cruciate ligament and lateral compartment arthritis for patients undergoing medial unicompartment knee replacement was presented by Simon White. Based on a series of 18 cases he concluded that only rarely was MRI of assistance.

Mohammad Hassaballa presented his study of kneeling after UKR which showed some improvement in the ability of the patients to kneel after surgery but still only 26% of patients could kneel though this was better than patients who had undergone TKR or PFR.

Chris Dodd presented his experience with ‘Field Block’ analgesia following Oxford medial unicompartment knee replacement. He advocated copious use of ropivicain with adrenalin and keteorolec. Ropivicain, he pointed out, has more sensory than motor inhibition. Excellent immediate pain relief was achieved though analgesic coverage on the second post-operative day was less good despite using a high dose of anti-inflammatory. Although many patients were thought ready for early post-operative discharge this was not always happening, but the method gave good pain relief in the post-operative period and allowed rapid rehabilitation.

The afternoon session concluded with a live telecast of Avon patello-femoral replacement from the operation theatre followed by a hands-on workshop on Avon patello-femoral replacement and some case discussions.