THE HUMERAL SHAFT FRACTURE FIXATION (HU-FIX) STUDY: A PROSPECTIVE RANDOMIZED TRIAL OF OPERATIVE VERSUS NONOPERATIVE MANAGEMENT OF FRACTURES OF THE HUMERAL DIAPHYSIS

Humeral shaft fractures are routinely managed non-operatively, but this approach is potentially associated with higher nonunion rates and inferior functional outcomes when compared to operative fixation. This single-centre prospective randomized trial aimed to assess whether there was any difference in outcome between surgery and bracing for adults with an isolated, closed humeral shaft fracture. A prospective, superiority, parallel-group randomized clinical trial was conducted between September 2018 and October 2023 at an academic major trauma centre in the UK. Seventy patients (mean age 49 years, 54% female) were randomized to either open reduction and plate fixation (n=36/70) or functional bracing (n=34/70). Exclusion criteria included absolute indications for surgery, pathological/periprosthetic fractures, polytrauma, significant frailty and inability to comply with follow-up. Seven patients did not receive their assigned treatment (operative n=5/32, non-operative n=2/32); intention-to-treat analyses were employed. The primary outcome measure was the Disabilities of the Arm, Shoulder and Hand score (DASH) at three months. Secondary outcomes included health-related quality of life (EuroQol 5-Dimension [EQ-5D]/health visual analogue scale [EQ-VAS] and SF-12 Physical [PCS]/Mental Component Summary [MCS] scores), pain VAS, shoulder/elbow range of motion and complications. At three months, 66 patients (94%) had complete follow-up. The operative group had a significantly better DASH (difference 15.0, p=0.006). Surgery was also associated with a superior DASH at six weeks (difference 14.7, p=0.005), but not at six (p=0.098) or 12 months (p=0.782). Surgery was associated with a higher EQ-5D (6wks: difference 0.126, p=0.03), EQ-VAS (6mths: difference 7, p=0.039) and SF-12 MCS (6wks: difference 9.3, p=0.001; 3mths: difference 6.9, p=0.008; 6mths: difference 7.1, p=0.007). Pain scores were superior over the first six months in the surgery group (body pain 6wks: MD 12/100, p=0.02; body pain 6mths: MD 10/100, p=0.023; limb pain 6mths: MD 1.2/10, p=0.027). Surgery conferred superior shoulder elevation, abduction and external rotation at six weeks and three months, along with elbow flexion at three months and one year (all p < 0 .05). Brace-related dermatitis was more common in the non-operative group (18% vs 3%; OR 7.8, p=0.049). There were eight (11%) nonunions (non-operative 18% vs operative 6%; OR 3.8, p=0.14). There was no difference in return to work, but surgery conferred a higher rate of return to sport (94% vs 57%; p=0.027). There were no other differences in outcomes between the groups. For patients with a humeral shaft fracture, surgery conferred early functional advantages over bracing. However, these benefits should be considered in the context of potential operative risks and the absence of any difference in outcomes at one year post-intervention.