Do patients with osteoarthritis lose weight prior to elective joint replacement?

Obesity is a known risk factor for the development of osteoarthritis and the subsequent need for joint replacement. Weight loss has been shown to reduce pain, disability, and the need for joint replacement, particularly in patients with knee osteoarthritis. The aim of this study was to investigate pre-operative weight change in patients with hip, knee, and shoulder osteoarthritis at a regional, public hospital in Australia, to identify opportunities for pre-operative weight-loss intervention.

A retrospective review of patients who underwent elective primary total hip (THR), knee (TKR), and shoulder (TSR) replacement for osteoarthritis was conducted between December 2019 and December 2022. BMI data were collected at three time points: (1) general practitioner (GP) referral; (2) orthopaedic clinic review; and (3) pre-admission clinic (PAC) assessment.

A total of 496 patients were included in the study, of which 205 underwent THR, 251 underwent TKR, and 40 underwent TSR. The mean patient age was 67 years, and 46.4% were female. At the time of GP referral, the mean body mass index (BMI) was 31.4 kg/m². Across the study period, only 2% of patients experienced clinically significant weight loss pre-operatively (≥5% of total body weight).

This study has demonstrated that very few patients lose weight prior to undergoing joint replacement in the public sector in Australia. This highlights the need for targeted non-surgical weight loss interventions for patients currently awaiting joint replacement.