Objective To investigate the impact of joint capsule repair and external rotators suture on the prognosis in primary total hip arthroplasty (THA) by posterolateral approach. Methods Between January 2006 and June 2009, 159 patients with femoral neck fracture underwent primary THA by posterolateral approach, and were divided into 4 groups according to different treatments: joint capsule repair and external rotators suture were given in group A (n=38), only joint capsule repair in group B (n=39), only external rotators suture in group C (n=41), and no joint capsule repair or external rotators suture in group D (n=41). There was no significant difference in gender, age, cause of injure, disease duration, type of fracture, combined medical disease, or prosthesis selection among 4 groups (P gt; 0.05). The bleeding volume, drainage, postoperative hip dislocation rate, hip Harris score, and the hip range of motion (ROM) in internal rotation and external rotation were compared. Results There was no significant difference in operative time, bleeding volume, or drainage among 4 groups (P gt; 0.05). Postoperative hip dislocation occurred in 0, 0, 4 (9.8%), and 4 (9.8%) cases of groups A, B, C, and D, respectively, showing significant difference in incidence of postoperative hip dislocation among 4 groups (χ2=7.910, P=0.048). The hip Harris scores were significantly improved after operation when compared with preoperative scores in 4 groups (P lt; 0.05). Significant differences were found in hip Harris score at 6 weeks and 6 months after operation among 4 groups (P lt; 0.05); group D was significantly lower than groups A, B, and C, and groups B and C were significantly lower than group A (P lt; 0.05). There was no significant difference in the hip ROM in internal rotation among 4 groups at 6 weeks and 6, 12 months after operation (P gt; 0.05); but the hip ROM in external rotation were significantly bigger in groups A and C than in groups B and D at 6 weeks and 6 months after operation (P lt; 0.05). Conclusion Joint capsule repair and external rotators suture in primary THA by posterolateral approach do not increase the bleeding volume and drainage, but can reduce the early postoperative hip dislocation risk, increase the Harris score, and recover the external rotation function of involved hip. So joint capsule and external rotators should be repaired in THA by posterolateral approach.
Objective To investigate the role and mechanism of S100 calcium binding protein B (S100B) in osteoarthritis (OA) cartilage damage repair. Methods Twenty New Zealand rabbits were randomly divided into control group and model group, with 10 rabbits in each group. Rabbits in the model group were injured by the right knee joint immobilization method to make the artilage injury model, while the control group did not deal with any injury. After 4 weeks, the levels of interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) in synovial fluid were detected by ELISA method; the mRNA and protein expressions of S100B, fibroblast growth factor 2 (FGF-2), and FGF receptor 1 (FGFR1) in cartilage tissue were examined by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot assay. Human synovial fibroblasts (SF) were isolated and cultured in vitro. The effects of S100B overexpression and knockdown on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Moreover, the effects of FGFR1 knockdown in above S100 overexpression system on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Results ELISA detection showed that the expressions of IL-1β and TNF-α in the synovial fluid of the model group were significantly higher than those of the control group (P<0.05); qRT-PCR and Western blot detection showed that the mRNA and protein expressions of S100B, FGF-2, and FGFR1 in cartilage tissue were significantly higher than those of the control group (P<0.05). Overexpression and knockdown S100 could respectively significantly increase and decrease lipopolysaccharides (LPS) induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 (P<0.05); whereas FGFR1 knockdown could significantly decrease LPS induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 (P<0.05). Conclusion S100B protein can regulate the inflammatory response of SF and may affect the repair of cartilage damage in OA, and the mechanism may be related to the activation of FGF-2/FGFR1 signaling pathway.