gms | German Medical Science

Objectives: Recently, satisfactory results have been reported about using GAP II implant in revision total hip arthroplasty (RTHA). In current study, we investigated the short-term results of these implants for acetabular reconstruction in RTHA.

Methods: There were 122 patients (76 males and 46 females) aged 54.2±23.1 years underwent RTHA utilizing Gap II prosthesis. Structural allograft (bulk), morselized allograft and TMT augment were used in 27, 41 and 9 hips, respectively. A cemented polyethylene cup implanted with cement in Gap II implant. Patients were examined clinically and radiographically before and after the operation. Paprosky system was used to classify the bone defects. Pre- and postoperatively, modified Harris Hip score (MHHS) was completed for all patients. The cup stability was assessed using plain x-rays of the hip. Patients were followed for 24.5±11.3 months.

Results and Conclusion: There was no case of infection, deep venous thrombosis, pulmonary thromboembolic disease and dislocation. In one patient, motor-car accident resulted in cage failure and subsequent RTHA. Modified HHS was 49.7±13.1 preoperatively which significantly increased up to 87.5±14.5,postoperatively (p<0.001).

Acetabulum reconstruction in RTHA requires bone graft for bone defects and placing a metal cage to support the acetabulum and grafts. The characteristics of the Gap II, a hook for obturator foramen and extension plate effectively are helpful in anatomically placement of the acetabular component and more stabilized prosthesis. These features make GAP II to be associated with satisfactory outcomes in RTHA.