Abstract
Between 1992 and 2000, 120 shoulder arthroplasties have been inserted in patients with osteoarthritis at this hospital. Shoulder function was assessed using the ASES patient self-evaluation form and the Constant-Murley clinical index as well as evaluation including routine measurements of shoulder motion and pain. The mean follow-up was 4.4years (2 to 10years).
Movement, pain and both shoulder function scores significantly improved after operation with t-test values significant at P< 0.001 level. Three sub-groups of primary osteoarthritis (OA), avascular necrosis (AVN) and post traumatic arthritis (PTA) were analysed separately. Although each group was significantly improved after arthroplasty the AVN and PTA patients had significantly poorer results than OA patients for pain and the functional scores, except the AVN group for the Constant Murley score. General linear model analysis indicated that both Constant-Murley and ASES shoulder function scores were shown to be sensitive to change after treatment and that improvement was maintained for up to 8 years post-operation.
Kaplan-Meier analysis showed a significant difference in survival between the 3 sub-groups of OA, PTA and AVN with 5 of 16 PTA operations needing revision. This was reflected in function measurement with PTA values 20 points lower in both clinical (P=0.014) and self assessed functional status (P=0.004).
At each visit a true AP radiograph was taken. Radiological lucency was graded using the method of Matsen. The humeral components were inserted without cement and there were no signs of loosening. Just four components had lucency at one of 7 zones. There was a noticeably higher incidence of glenoid lucency, Proportional hazards analysis was used to model the hazard rate of glenoids at risk. A hazard model for the glenoid components consisted of only one variable – presence or absence of glenoid erosion noted at operation. The model is significant (P= 0.02) with erosion having a hazard rate 6 times greater than that if not eroded.
These abstracts were prepared by Mr Cormac Kelly. Correspondence should be addressed to him c/o British Orthopaedic Association, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN.
