Abstract
Introduction and Objective
Ankle fractures are common and affect young adults as well as the elderly. An unstable ankle fracture treatment typically involves surgical fixation, immobilisation, and modified weight-bearing for six weeks. Non-weight bearing (NWB) cast immobilisation periods were used to protect the soft tissue envelope and osteosynthesis. This can have implications on patient function and may reduce independence, mobility and return to work. Newer trends in earlier mobilisation compete with traditional NWB doctrine, and weak consensus exists as to the best postoperative strategy. The purpose of this trial is to investigate the safety and efficacy of immediate weight-bearing (IWB) and range of motion (ROM) exercise regimes following ORIF of unstable ankle fractures with a particular focus on functional outcomes and complication rates.
Materials and Methods
A pragmatic randomised controlled multicentre trial, comparing IWB in a walking boot and ROM within 24 hours versus non-weight-bearing (NWB) and immobilisation in a cast for six weeks, following ORIF of all types of unstable adult ankle fractures (lateral malleolar, bimalleolar, trimalleolar with or without syndesmotic injury). The exclusion criteria are skeletal immaturity and tibial plafond fractures. The primary outcome measure is the functional Olerud-Molander Ankle Score (OMAS). Secondary outcomes include wound infection (deep and superficial), displacement of osteosynthesis, the full arc of ankle motion (plantar flexion and dorsal flection), RAND-36 Item Short Form Survey (SF-36) scoring, time to return to work and postoperative hospital length of stay.
Results
We recruited 160 patients with an unstable ankle fracture. Participants’ ages ranged from 15 to 94 years (M = 45.5, SD = 17.2), with 54% identified as female. The mean time from injury to surgical fixation was 1.3 days (0 to 17 days). Patients in the immediate weight-bearing group had a 9.5-point higher mean OMAS at six weeks postoperatively (95% CI 1.48, 17.52) P = 0.021. The complications rate was similar in both groups. The rate of surgical site infection was 4.3%. One patient had DVT, and another patient had a pulmonary embolism; both were randomised to NWB. Length of hospital stay (LOS) was 1 ± 1.5 (0, 12) for the IWB group vs 1.5 ± 2.5 (0, 19) for the NWB group.
Conclusions
There is a paucity of quality evidence supporting the postoperative management regimes used most commonly in clinical practice. To our knowledge, immediate weight-bearing (IWB) following ORIF of all types of unstable ankle fractures has not been investigated in a controlled prospective manner in recent decades. In this large multicentre, randomised controlled trial, we investigated immediate weight-bearing following ORIF of all ankle fracture patterns in the usual care condition using standard fixation methods. Our result suggests that IWB following ankle fracture fixation is safe and resulted in a better functional outcome. Once anatomical reduction and stable internal fixation is achieved, we recommend IWB in all types of ankle fractures in a compliant patient.
