Immediate versus delayed weight bearing for fractures of the pelvis, acetabulum, distal femur, and proximal and distal tibia: a feasibility randomized controlled trial

Abstract Background Early weight bearing is frequently allowed and encouraged following fixation of hip and femoral and tibial shaft fractures, while pelvis, acetabulum, and lower extremity periarticular fractures are often prescribed 6–12 weeks of restricted weight bearing. Our objective was to perform a feasibility randomized trial of immediate versus delayed weight bearing as tolerated (WBAT) for fractures of the pelvis, acetabulum, distal femur, and proximal and distal tibia. Methods A parallel two-arm pilot feasibility trial was performed at one academic level I trauma center. Patients with a fracture of the pelvis, acetabulum, distal femur, proximal tibia, or distal tibia were eligible. Patients were randomized to either immediate WBAT or delayed (≥6 weeks) weight bearing after surgery. Our feasibility criteria included: 1) 25% overall enrollment (surgeon and patient agreement to participate in 50% eligible cases each), 2) > 90% follow-up at 3 months), 3) 100% correct documentation of weight bearing status, and 4) 100% correct documentation of primary outcomes (reoperation and hardware failure). Results Surgeons allowed inclusion of 64/133 (48.1%) of eligible patients (by fracture type: 76% of pelvis, 43% of acetabulum, 38% of distal femur, 45% of proximal tibia [39% of tibial plateau], and 56% of distal tibia fractures). 50/64 (78%) of these patients agreed to participate in the study, for an overall enrollment of 38% (50/133). The follow-up rate was 46/50 (92%) at the 3-month follow-up. Correct documentation of postoperative weight bearing status and the primary outcomes of reoperation and hardware failure were achieved in all cases 50/50 (100%). There were two reoperations (one hardware failure and one wound infection) in the immediate WBAT group, and none in the delayed weight bearing group. Conclusion All four of the feasibility criteria were met. While we did not meet our target of 50% of patients whom surgeons were willing to randomize, we did exceed the target of 25% overall patient enrollment. This feasibility trial demonstrates that a randomized controlled trial of early versus delayed weight bearing would be feasible for certain fracture types. Future study design will incorporate additional patient and fracture characteristics that may make surgeons unwilling to allow randomization. Trial Registration: ClinicalTrials.gov identifier: NCT05595148