A prospective cohort study on the effect of low back pain in patients undergoing total hip arthroplasty

Evaluation of patients with hip arthritis for total hip arthroplasty (THA) may be confounded by concomitant low back pain (LBP).

To study the prevalence and outcome of LBP in THA patients. To evaluate the outcome of THA in patients with dysfunctional low back pain (DLBP).

In patients undergoing THA, low back pain was assessed with the Roland Morris Disability Questionnaire (RMDQ) and Numerical Pain Rating Scale (NPRS) scores preoperatively and 1 year postoperatively. Patients were categorised as suffering from DLBP if their RMDQ score was >4. Hip function was assessed using the modified Harris Hip Score (mHHS).

26 of 79 (33%) patients had DLBP before THA. At 1 year follow-up, 19 of them either no longer suffered from DLBP (RMDQ ⩽ 4) or at least had improvement in their RMDQ scores ⩾ 5 suggesting discerning clinical improvement. The mean NPRS scores for LBP at one year also improved (1.5 vs. 0.7, p < 0.01). The mean mHHS at 1 year in patients without DLBP was significantly higher than those with DLBP (85.15 vs. 75.81, p = 0.003) implying that patients without DLBP had better hip outcomes following THA.

DLBP improves considerably after THA. The outcome of THA may be adversely affected by the presence of DLBP.