Double taper hydroxyapatite-coated implant tied to lower postoperative periprosthetic femur fractures

However, literature indicates higher risks of postoperative periprosthetic femur fractures (PPFFs) with both direct anterior THA and uncemented femoral stems.

Therefore, R.M.Fuller and colleagues from the Department of Orthopaedics, Bluegrass Orthopaedics, Yorkshire Medical Park, Lexington, USA carried out this retrospective study to investigate the influence of femoral stem design on PPFF incidence in uncemented direct anterior THA among patients older than 70 years.

557 primary THAs in patients aged 70 or over were reviewed for PPFFs from a consecutive series of 2011 patients undergoing direct anterior THA from a fellowship-trained adult reconstruction surgeon. Exclusion criteria included age (<70) and posterior approach.

For the first cohort of 361 patients (79 of which passed exclusion criteria) the surgeon used a single-tapered, proximally porous coated, collarless titanium stem. For the next 1650, (478 of which passed exclusion), the surgeon used a dual-tapered, collared, hydroxyapatite-coated titanium stem.

Included patients were carefully monitored for PPFFs. A Fisher's exact test was used to compare the incidence PPFFs between the 2 implant designs.

The study highlighted that 2 of 79 (2.5%) patients had atraumatic PPFFs at an average of 19.5 days post-operatively in the first cohort. Both experienced a Vancouver type B2 periprosthetic fracture and required femoral revision. However, no patients (0/478, 0%) in the second group sustained a PPFF. (P = 0.0199).

Hence, the authors concluded that "the dual-taper, hydroxyapatite-coated implant had a significantly lower PPFF rate among elderly patients than a single-taper, proximally porous stem without a collar."