Objective To compare the differences in acetabular position during total hip arthroplasty (THA) between by direct anterior approach and by posterolateral approach. Methods Between December 2008 and December 2015, 102 patients undergoing THA were included in the study. THA was performed by anterior approach in 51 cases (anterior group) and by posterolateral approach in 51 cases (posterolateral group). There was no significant difference in gender, age, body mass index, side, and cause of illness between 2 groups (P>0.05), with comparability. The acetabular abduction angle and anteversion angel were measured on the X-ray film at 1 day after operation to evaluate whether the acetabular prosthesis was displaced in the safe zone. Results The acetabular abduction angle was (42.28±5.77)° in the anterior group and was (43.93±7.44)° in the posterolateral group, showing no significant difference (t=1.30, P=0.19). The acetabular anteversion angle was (21.14±5.17)° in the anterior group and was (21.05±4.10)° in the posterolateral group, showing no significant difference (t=0.05, P=0.96). The ratio in the target safe zone of the acetabular abduction angle in the anterior group and the posterolateral group were 88.2% (45/51) and 84.3% (43/51) respectively, showing no significant difference (χ2=0.33, P=0.56). The ratio in the target safe zone of the acetabular anteversion was 80.4% (41/51) in the anterior group and was 82.4% (42/51) in the posterolateral group, showing no significant difference between 2 groups (χ2=0.06, P=0.79). The ratio in the target safe zone of both the abduction and anteversion angel was 70.6% (36/51) in the anterior group and was 68.6% (35/51) in the posterolateral group, showing no significant difference (χ2=0.05, P=0.82). Conclusion There is no differences in the acetabulum position during THA between by direct anterior approach and posterolateral approach.
Objective To study the expression difference of Sclerostin in the medial and lateral subchondral bone of the varus osteoarthritic knee plateau. Methods The tibial plateau was obtained from 20 patients with varus knee osteoarthritis receiving total knee arthroplasty from March to October 2015. There were 8 males and 12 females with an average age of 67.8 years (range, 61-78 years). The mean course of osteoarthritis was 3.2 years (range, 2-5 years). Before operation, the varus angle was 12.0-25.5° (mean, 17.6°) on the X-ray film. Five cases were rated as grade III and 15 cases as grade IV according to Kellgren-Lawrance classification. Micro-CT scan was performed on the medial and lateral subchondral bone to compare the changes of bone structure; bone volume/total volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), structure model index (SMI), and the trabecular separation (Tb.Sp) were measured. Immunohistochemistry and real-time fluorescent quantitative PCR were used to test the expressions of Sclerostin protein and sost gene. Results Micro-CT showed that BV/TV, Tb.N, and Tb.Th significantly increased in the medial subchondral bone when compared with the lateral part (P<0.05), but SMI and Tb.Sp significantly reduced (P<0.05). Real-time fluorescent quantitative PCR detection showed that sost gene expression level in the medial subchondral bone (1.000) was significantly lower than that in the lateral part (4.157±2.790) (t=2.371,P=0.040). The percentage of Sclerostin positive cells in the lateral subchondral bone (52.00%±0.19%) was significantly higher than that in the medial subchondral bone (7.20%±0.04%) (t=5.094,P=0.005). Conclusion Sclerostin plays an important role in the subchondral bone remodeling of the varus osteoarthritic knee. And the low expression of Sclerostin may be an important factor to promote bone remodeling and aggravate knee deformity.
ObjectiveTo retrospectively compare the mid-term effectiveness between by direct anterior approach (DAA) and by posterolateral approach in total hip arthroplasty (THA).MethodsBetween January 2009 and December 2010, 110 patients (110 hips) treated with THA and followed up more than 5 years were chosen in the study. THA was performed on 55 patients by DAA (DAA group), and on 55 patients by posterolateral approach (PL group). There was no significant difference in gender, age, body mass index, types of hip joint disease, and preoperative Harris score between 2 groups (P>0.05). The operation time, amount of bleeding, length of hospital stay, postoperative complications, and the Harris scores were recorded and compared.ResultsThere was no significant difference in operation time and length of hospital stay between 2 groups (t=0.145, P=0.876; t=1.305, P=0.093). The amount of bleeding was significantly less in DAA group than in PL group (t=2.314, P=0.032). All patients were followed up 5-7 years (mean, 5.97 years). Complications happened in 5 cases (9.1%) of DAA group and in 3 cases (5.5%) of PL group, and there was no significant difference in the incidence of complications between 2 groups (χ2=0.539, P=0.463). There was significant difference in Harris scores at 6 months after operation between 2 groups (t=2.296, P=0.014), but no significant difference was found in Harris score at 1 year and 5 years between 2 groups (t=1.375, P=0.130; t=0.905, P=0.087). Further analysis, at 6 months after operation, the joint function score in DAA group was significantly higher than that in PL group (t=1.087, P=0.034), while there was no significant difference in the pain score and range of motion score between 2 groups (t=1.872, P=0.760; t=1.059, P=0.091).ConclusionTHA by DAA has the advantages of less bleeding and faster recovery. The short-term effectiveness is superior to the THA by traditional posterolateral approach, but there is no obvious advantage in the mid-term effectiveness.