[Comparison of 127° small and 135° large stem angle prostheses in total hip arthroplasty]

To investigate the effect of total hip arthroplasty(THA) with the prosthesis of 127° small neck stem angle and 135° large neck stem angle.

From January 2014 to June 2016, 84 patients with THA were selected, including 44 males and 40 females, aged 45 to 72(53.4±8.1) years old, 68 patients with necrosis of the femoral head(32 on the left and 36 on the right), 16 patients with serious osteoarthritis of the hip caused by other reasons, and the course of disease was 9 to 36 (24.0±5.5) months. Forty-two patients in each group were evaluated by Harris score, visual analog score(VAS), length measurement of lower limbs, biomechanical evaluation of different angles of the neck stem. The complications and quality of life 24 months after operation were compared.

Two patients in each group were lost, the rest were followed up for 30 to 36 (33.0±1.6)months. The Harris score and the length of both lower limbs were measured before and 1, 6, 12, 24 months after operation. The difference of Harris score and the length of both lower limbs in the two groups was significantly improved compared with that before operation(P<0.05), but there was no significant difference between the two groups(P>0.05). There was no significant difference between the two groups in VAS score before operation (P>0.05), but the VAS score of the group with large neck stem angle was significantly lower than that of the group with small neck stem angle(P<0.05). There was no significant difference in the incidence of postoperative complications between the two groups (P>0.05). The quality of life of the patients in the two groups after 24 months was significantly higher than that before operation (P<0.05).

THA with large and small neck stem angle prosthesis can better recover the function of hip joint, but large neck stem angle can reduce the degree of postoperative pain and improve the quality of life of patients.