[Surgical treatment of a displaced femoral head fracture with a cement-free dual-headed prosthesis using a minimally invasive approach. Clinical and radiographic outcome]

Abstract

One hundred patients treated with a cementless bipolar prosthesis for a displaced subcapital hip fracture were prospectively evaluated for clinical and radiographic outcome. All patients were operated via a minimally invasive approach; in every case we implanted a Zweymuller stem. There were 77 women and 33 men with a mean age of 80 years (29-98 years). The mean duration of the operation was 29 min (20-95 min). Full weight bearing on crutches was allowed 1 day after the operation. The mean follow-up was 2.5 years (6 months to 7 years). Two years after the operation there were 40% of the remaining 65 patients who scored between 90 and 100 on the Harris hip score, 23% between 80 and 89, 20% between 70 and 79, and 17% below 70. No patient complained about thigh pain and up to now there has been no need for femoral revision due to loosening. There was no infection or nerve lesion. In three patients there was a luxation of the prosthesis which could be reduced by closed means. Radiographs from 81 patients showed stress shielding in 97.5% mainly in Gruen zones 1 and 7. Radiolucent lines in two or more Gruen zones were found in two patients. These findings suggest that the noncemented, pressfit, grit-blasted bipolar prosthesis demonstrated similar stability and radiographic results to cemented bipolar prostheses. Stress shielding was common but did not influence longevity of the implant. We did not find any signs of protrusion. Especially in older patients with a history of cardiac disease, the noncemented bipolar prosthesis is a rational alternative to avoid intra- and postoperative complications despite the higher costs for the implant. The minimally invasive approach helps to reduce operation time and intraoperative blood loss.