Mid-Term Clinical Results of VerSys Hip System (Zimmer) Uncemented Total Hip Replacement Arthroplasty

抄録

Recent reports suggest that uncemented total hip replacement arthroplasty (THR) results in favorable short- to mid-term clinical results. In the present study, we assessed the mid-term clinical results of VerSys Hip System uncemented THR at our hospital. Materials and Methods: We studied patients who received THR using VerSys Hip System and who could be followed-up more than 3 years. Clinical records were used to retrospectively identify patient characteristics, which included age, gender, disease requiring THR, preoperative and postoperative pain score of the Japan Orthopaedic Association scoring system, range of motion in flexion and abduction, operating time, intraoperative complication, and additional operation or revision surgery. Additionally, we investigated the loosening and alignment of implants from X-ray films. Results: Ninety-one patients and 108 hip joints were investigated. Subjects were 11 males and 97 females (mean age, 64.6 years). Mean follow-up period was 6.9 years. Reasons for requiring THR were as follows: secondary osteoarthritis, 87 joints; idiopathic osteonecrosis of the femoral head, 16 joints; rapidly destructive coxarthrosis, 4 joints; and idiopathic ossification of the labrum, 1 joint. Mean operating time was 166 minutes. A total of 11 intraoperative fractures occurred, and wiring was performed in 3 of those cases. Adverse events pertaining to the surgery were limited; however, another adverse event was that 1 case resulted in intraoperative perforation of femoral cortex, for which a revision surgery was performed. There was no dislocation. Pain score using the Japan Orthopaedic Association scoring system and range of motion tests showed statistically significant improvement following THR. At the final follow-up, although no loosening of femoral implants was observed, the loosening of acetabular component was seen in 1 case. Varus insertion of femoral implant was recognized in 40 joints. Moreover, the average inclination angle of acetabular implants was 52.2 degrees. Conclusion: These data suggest that patients receiving VerSys Hip System uncemented THR demonstrate favorable results pertaining pain score and range of motion. However, high rate of intraoperative fracture and malalignment of implants, which may be at a risk of dislocation and/or polyethylene wear in future, suggests that this implant technique requires improvement.