The Influence of Leg Length Discrepancy After Total Hip Arthroplasty on Function and Quality of Life

Leg length discrepancy (LLD) is a complication of THA and may result in patient dissatisfaction, gait disorder, greater trochanter pain, low back pain. In the literature, LLD is reported to vary widely among studies e.g. 6 to 35 mm. However, the threshold at which a LLD is clinically important is still a matter of debate. The aim of this study was to determine the influence of non-corrected LLD after THA on patients' reported hip function and quality of life. This prospective cohort study was conducted at Sundsvall Teaching Hospital in Sweden after it was approved by the regional ethics committee at Umeå University (No. 07-052M and No. 12-287-32M). Between September 2010 and April 2013, all patients with unilateral primary osteoarthritis (OA) treated with THA were considered for inclusion. Informed consent was obtained from all patients. Patients with secondary OA, previous spinal, pelvic, or lower limb injuries or fractures were excluded.

The primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index that measures functional outcome (ref). The secondary outcome measure was the EQ-5D and visual analogue scale (VAS) scale. Patients were assessed preoperatively and at follow-up at 1 year postoperatively. The posterolateral approach was used in all operations. LLD was measured on the postoperative x-rays. patients were divided into three groups: shortening group where the operated leg was more than 5mm shorter compared with the contralateral side, the restoration control group where the operated leg was within 5mm shortening and 9mm lengthening compared with the contralateral side, and the lengthening group where the operated leg became more than 9mm longer compared with the contralateral side.