[Treatment of periprosthetic femoral fractures after total hip arthroplasty with specially constructed retrograde hollow nails]

Abstract

Aim: Treatment of periprosthetic fractures by implantation of a specially constructed, retrograde hollow nail which fits over the tip of the prosthesis and becomes locked on it.

Indications: Periprosthetic femoral fractures with firmly anchored prosthesis shaft after total hip arthroplasty of types B1 and C according to the Vancouver classification.

Contraindications: Loosened prosthesis (type B2/B3) and trochanteric fractures (type A). Broken or damaged prosthesis, florid inflammation and soft tissue injuries in the operation field, contracted knee joint, advanced deformation in the knee joint and distal femur, enclosed prosthesis and general contraindications.

Surgical technique: In a supine position the periprosthetic fracture is exposed via a lateral access. For cemented prostheses the cement is removed around the tip of the prosthesis (at least 2-3 cm) and medullary cavity. Arthrotomy with flexion of the knee joint and marking of the nail entry point. Drill the medullary cavity, retrograde introduction of the nail, visually fit the nail over the tip of the prosthesis and lock the nail with the prosthesis. If necessary use additional spongiosaplasty or also placement of additional cerclages depending on fracture type and size of the defect zone. Lock the nail distally. Use intraoperative radiological imaging to control correct positioning and length of the nail. Close the wound layer by layer with placement of suction drainage devices and dressing.

Postoperative management: Partial loading for 6 weeks with a subsequent pain-adapted loading gradient until full loading is possible. If selective partial loading is not possible, a decision must be made in individual cases as to whether the intraoperative findings allow immediate full loading.

Results: From 2004 to 2011 a total of 25 periprosthetic femoral fractures in 25 patients were treated in 2 locations using specially constructed slotted hollow nails. Within the framework of a retrospective study 20 of these patients (16 female and 4 male; average age 77.2 [72-84] years) were clinically and radiologically re-examined on average 19.3 (7-31) months postoperatively. No postoperative bleeding, wound healing disorders and infections. In all patients there was a loading stable consolidation of the fracture in the correct femoral axis, length and rotation with no evidence for radiological signs of loosening of the prosthesis or dislocation of the nails. In one case there was loosening of the prosthesis which had obviously occurred during the operative procedure. After consolidation of the fracture it was necessary to exchange the prosthesis for a long shafted prosthesis. A comparable situation to the preoperative degree of mobility was found in 12 out of the 20 patients, a moderate deterioration in 5 patients, a substantial residual impairment in 2 patients and an improvement of the situation in 1 patient.