Does restoration of leg length and femoral offset play a role in functional outcome one year after hip hemiarthroplasty?

Background: The objective of this study was to evaluate the correlation between specific joint biomechanical parameters and 1year functional outcome scores in elderly patients receiving hemiarthroplasty in the setting of intracapsular hip fractures.

Methods: This is a retrospective, institutional registry based study. 168 hip hemarthroplasties were captured from October 2013 to June 2015. Patients were excluded based on contralateral hip surgery, perioperative complications or inadequate radiographs. 84 patients were alive at one year follow up. We compared mobility and pain scores to radiographically determined variations of leg lengths and femoral offset. We also compared the performance of fellowship trained arthroplasty surgeons to their non-fellowship trained counterparts.

Results: The operated leg was a mean of 1.12±6.8mm longer than the contralateral. leg length discrepancy (LLD) was less than 10mm in 72 patients. Mean difference in offset between limbs was 0.25±3.3mm. The difference was within 5mm in 79 patients (94%). We found no statistically significant correlation between mobility or pain scores and variations in leg length or offset. We found significantly better performance of the arthroplasty surgeons in restoring leg length but no difference in offset reconstruction or functional benefit for the patient.

Conclusions: Our study was unable to demonstrate a significant relationship between leg length or femoral offset restoration and the patient's ultimate functional recovery. Arthroplasty surgeons performed better in restoring leg length, but no associated functional advantage was seen.