Primary total hip arthroplasty using jumbo femoral heads (40 and 44 mm) : a series of over 1,800 patients.

AIMS

The use of jumbo femoral heads, defined as those with a diameter of ≥ 40 mm, in primary total hip arthroplasty (THA) has gained popularity, to mitigate dislocation. The aim of this study was to determine the risk of dislocation, implant survival, and clinical outcomes of a large cohort of primary THAs with jumbo femoral heads.

METHODS

We conducted a retrospective analysis of 1,828 primary THAs with jumbo femoral heads, which were undertaken for osteoarthritis, in 1,578 patients between January 2000 and December 2022, at a single academic medical centre. The femoral head diameter was 40 mm in 1,584 THAs (87%) and 44 mm in 244 THAs (13%). The outer diameter of the acetabular component ranged from 52 mm to 72 mm in those with 40 mm heads, and from 54 mm to 78 mm in those with 44 mm heads. The types of bearing included ceramic-on-highly cross-linked polyethylene (1,229 THAs; 67%) and metal-on-polyethylene (599 THAs; 33%). Elevated liners were used in 472 THAs (26%) and 1,083 (59%) were lateralized. The most common operative approach was posterior (1,388 THAs; 76%). Outcomes of interest included the rate of dislocation, revision for dislocation, any revision, any reoperation, and the Harris Hip Score (HHS). The mean age of the patients at the time of THA was 64 years (8 to 94); 1,477 (81%) were male, and their mean BMI was 28 kg/m² (5 to 55). The mean follow-up was six years (2 to 14).

RESULTS

The ten-year survival free of dislocation was 97% (95% CI 96 to 98; 97% for 40 mm heads (95% CI 95 to 98) and 99% for 44 mm heads (95% CI 97 to 100) (hazard ratio 3 (95% CI 1 to 14); p = 0.106)). The ten-year survival free of revision for dislocation was 99.6% (95% CI 99 to 100) (99.5% for 40 mm heads (95% CI 98 to 100) and 100% for 44 mm heads (p = 0.546)). The ten-year survival free of any revision and any reoperation was 95% (95% CI 94 to 97) and 93% (95% CI 91 to 95), respectively. There were no significant differences in survival free of any revision (p = 0.746) or any reoperation (p = 0.762) between the two groups.

CONCLUSION

In this large single-centre study of the use of jumbo femoral heads in primary THAs, the ten-year survival free of dislocation was 97%, with extremely few revisions for dislocation. These results highlight the potential for jumbo femoral heads to reduce the risk of dislocation and enhance implant longevity without compromising other clinical outcomes.