Increased risk of high-grade heterotopic ossification using direct lateral approach versus a muscle-sparing anterolateral approach to the hip: radiological results from a randomised trial in patients with a femoral neck fracture treated with hemiarthroplasty

Abstract

Background and purpose: Hemiarthroplasty is a common treatment in patients with displaced femoral neck fracture. Due to positive claims of less pain, earlier mobilisation and favourable functional outcome, the anterior approaches to the joint are gaining in popularity. This randomised controlled trial investigated if component placement and heterotopic ossification differed between a muscle sparing anterior approach and a direct lateral approach. Patients and methods: 150 patients operated with an uncemented hemiarthroplasty, were randomised to anterolateral or direct lateral approach and assessed postoperatively radiologically. Measurements included leg-length discrepancy, femoral offset, femoral stem position, canal fill ratio and the presence of heterotopic ossification after 12 months. Results: There was an increased risk of high-grade heterotopic ossification in the direct lateral approach ( p < 0.05). We found no statistically significant differences in leg-length discrepancy, femoral stem position or femoral offset. Conclusions: Hemiarthroplasty performed in the direct lateral approach resulted in a higher incidence of Brooker grade 3 heterotopic ossification. Our results support equal geometrical restoration and similar component placement with both approaches. Clinical trial registry: ClinicalTrials.gov Identifier: NCT03974698 Uncemented Hemiarthroplasty, Radiological Features Comparing Lateral Versus Anterolateral Approach https://www.clinicaltrials.gov/ct2/show/NCT03974698?term=raymond+tellefsen…draw=2…rank=1