OBJECTIVETo study short-term results and clinical application of Tri-lock BPS in total hip arthoplasty.

METHODSFrom May 2010 to July 2011, 32 hips in 31 patients (18 males and 13 females, ranging in age from 50 to 77 years old, with an average of 60.5 years old) were treated by total hip arthroplasty with Tri-lock BPS, including 8 patients with osteonecrosis (ON), 13 patients with fresh femoral neck fracture, 10 patients with developmental dysplasia of the hip (DDH). The therapeutic effects were evaluated by self assessment form, preoperative and postoperative Harris hip score, radiographs, Engh score and bone in growth of femoral side described by Gruen. Based on the short-term results,its design characteristic and clinical properties were analyzed.

RESULTSAll the incisions healed well and there were no complications such as femoral fracture, infection, dislocation and neurovascular injuries. All the patients were followed up with an average time of 12.2 months (ranged, 10 to 14 months). All the joints had good or excellent clinical results. The Harris score increased from preoperative 38.3 +/- 4.9 to 92.5 +/- 11.2 at the latest follow-up (t = 27.53, P < 0.01). Radiographically, the positions of the prostheses were normal,the average limbs length and femoral eccentricity recovered to normal. X-ray of the hips showed that the femoral stem prosthesis was in line with good initial fixed standard. At 3 months after surgery, X-ray of the hips showed that bone in growth in Gruen II and VI of femoral side.

CONCLUSIONShort-term results show that the design of Tri-lock BPS is more in line with human anatomy, and has the advantages in rapid recovery of hip function and retains more bone mass. It offers a newly valuable technology for the treatment of osteonecrosis, femoral neck fracture and DDH and so on.