ABSTRACT
Objective To investigate the effect of spine disease on pelvic sagittal alignment and hip biomechanics in total hip arthroplasty (THA) patients. Methods The clinical data of 120 THA patients who had normal lumbar spine (control group) and 40 THA patients who had lumbar disease (lumbar disease group) between January 2013 and September 2015 in Shenzhen Longhua District People′s Hospital were analyzed. Radiographical parameters, like lumbar lordosis (LL), pelvic incidence(PI), pelvic tilt (PT) and sacralslope (SS) were collected and compared. Normal and pathological musculoskeletal simulation model was established based on standing and sitting X-ray pelvic alignment. Hip contact force, moment and muscle forces in standing posture and sitting to standing posture were calculated. Results The value of LL in lumbar disease group was shorter than that in control group:(34.23 ± 12.81)°vs. (47.26 ± 14.67)°, P＜0.05. Butthe value of PI in two groups had no significant difference (P>0.05). The value of PT and SS in two groups had significant differences: (17.51 ± 2.31)°vs. (8.31 ± 1.34)°,(27.61 ± 1.72)°vs. (38.01 ± 1.92)°, P＜0.05. At standing position and sitting moment position, the joint force and moment value between disease model and control model had significant differences (P＜0.05), and the differences were mainly in sagittal and vertical axis (P＜0.05). At standing position and the moment of sitting up, the extorsion muscle activation was at lower level and had no significant difference (P＞0.05). Conclusions Pelvic sagittal alignment pathology could change hip biomechanical situation, making threats to hip stability.
ABSTRACT
BACKGROUND:There are many methods in the clinic to treat pelvic fractures, mainly conservative treatment, internal fixation and external fixation. Conservative treatment often causes complications due to poor reduction after fractures. Fixation has good effects on repair of unstable fractures, but fixation is seldom used for pelvic fractures. OBJECTIVE:To observe the effects of internal fixation on unstable pelvic fractures, and compare with conservative treatment and external fixation. METHODS:126 cases of unstable pelvic fractures from Longhua District People’s Hospital of Shenzhen City from January 2008 to June 2014 were divided into three groups:conservative treatment group, external fixation group and internal fixation group (n=42). After treatment, patients received X-ray examination. Lindahl imaging criteria were used as evidence. The quality of fracture reduction was evaluated. Patients were regularly fol owed up after treatment. The recovery of limb function was evaluated according to Majeed standard. Repair effects, the excel ent and good rates of fracture healing and cal us growth were evaluated in the last fol ow-up. RESULTS AND CONCLUSION:During the last fol ow-up, the total efficiency was 81%in the internal fixation group, 69%in the conservative treatment group, and 71%in the external fixation group, and results were significantly better in the internal fixation group than in the other two groups (P<0.05). The Lindahl and Majeed scores were significantly higher in the internal fixation group than in the other two groups (P<0.05). These results suggest that internal fixation for unstable pelvic fracture obtained better recovery effects and efficiency than conservative treatment and external fixation. Thus, the internal fixation is more suitable for patients with unstable pelvic fractures.