Abstract
Minimal invasive surgery (MIS) is accepted when the scar is 10 cm or less. The anterior and the antero-lateral approaches had gained recently interest in the total hip arthroplasty because they allow complete muscle sparing. The postero-lateral and lateral approaches were propsed to be less satisfactory from this point of view. The goal of this paper was to report an objective and carfull assessment of the advantages of the minimal invasive posterior approach in short stem (Nanos) total hip arthroplasty.
Material and methods
From juli 2005 to march 2009 a total of 113 (70 males,53 female) uncemented Nanos-short-stem prothesis were implanted in 111 patients. The patiens average age was 53 years (33-73). The indication for this procedure was predominantly coxarthrosis. In all cases a minimal invasive posterior approach was used. The mean follow up period was 2,5 years (range 6 months- 4,5 years). The patients were assessed using Harris Hip Score and radiologically to detect any bone changes, the stand of the prothesis and peri-articular ossifications
Results
The perioperative Harris Hip Score was 53 (28-77), postoperative was 94 (86-100). Untill now we have not discovered any prothesis specific complications. Radiological follow up examinations showed the development of increasing trabecular reinforciment of the femoral neck and pertrachanteric regions. There is no evidence of any loosing or migration of the prothesis. No luxation. Calcification was noted in 8 cases (Grad 1), 4 cases(Grad 2), 1 case (Grad 3). In 3 cases we have to change the cup because of malposition
Conclusion
the stem design of Nanos-short-stem prothesis allowed a metaphyseal intertrochanteric multipoint primary fixation. The surgical technique using posterior approach give a good access to the femur and acetabulum. It allows intraoperative ROM as well as extention in the event of intraopertive complications. Long term studies still be needed.
