[Preliminary experiences in minimally invasive and mini-incision surgery total hip arthroplasty for late osteonecrosis of the femoral head].

OBJECTIVE: To explore the effect of minimally invasive and mini-incision surgery (MIS) in total hip arthroplasty (THA) on late osteonecrosis of femoral head (ONFH).

METHODS: From March 2003, Eighteen patients (22 hips) with ONFH underwent MIS in THA. Their ages ranged from 24 to 57 years, including 13 males and 5 females. The mean body mass index ranged from 17.1 to 30.1 (24.6 on average). The Harris hip score was 46 points before operation. Modified posterior-lateral approach was adopted, and the MIS THA was performed by cementless prosthesis. As a comparison, 18 patients (22 hips) were performed by conventional THA at the same period. The data, including bleeding volume during operation, incision length, operative time, and postoperative function recovery, were compared.

RESULTS: Follow-ups were done for 6 to 20 months (11 months on average). Dislocation occurred in one patient that underwent conventional THA 2 days after operation. No complication occurred in MIS THA group. The incision lengths ranged from 8.7 to 10.5 cm (9.3 cm on average) in MIS THA group, being statistically different (P< 0. 01). There was no significant difference in Harris scoring of the function between the two groups both before the operation and after the operation (P>0.05). The operative time was almost the same, but the bleeding volume in MIS THA group was less (P<0.05). The function recovery was faster in MIS THA group.

CONCLUSION: The MIS THA is an alternative to the treatment of late ONFH. The advantages of MIS THA are fewer trauma, less bleeding volume, and faster recovery. The MIS THA should be performed by surgeons with rich experiences in THA and hospitals with necessary instruments.