Causes Analysis On Hip-Joint Diseases Induced Pelvic Tilts

Objective:To study the occurrence patterns of hip-joint diseases induced coronal pelvic tilts via analyzing causes and clinical features of them, and to discuss the classification method of pelvic tilts according to the characteristics of hip-joint characteristics.Method:180 patients with hip-joint diseases induced coronal pelvic tilt who were treated at Orthopedics in First Affiliated Hospital of Kunming Medical University from January 2012 to December 2014 were analyzed retrospectively. For the patients,99 were non-osteonecrosis of femoral head (NONFH),32 were primary osteoarthritis of hit-joint,22 were developmental dysplasia of hip-joint (DDH),17 were rheumatoid arthritis of hip-joint, and 10 were infectious hip osteoarthritis (OA). Comprehensive evaluation including general conditions, systemic conditions, focal conditions of hip-joint, images and others were performed for all patients.Tracing conditions progression and evolution situations upon history collection confirmed the onset of diseases (acute or chronic), clinical manifestations and quality of life; appearance, deformity features, WHO pain degree and ROA (range of motion) of hip joint were collected to evaluate hip functions and to confirm the types and mechanism of of affected hip functional changes; the pelvic tilts and shortness of the affect limb were confirmed via measuring the direction and degree of pelvic tilts and bilateral Spine-Ankle Lines (from anterior superior spine to both bony eminences of medial ankles) and Navel-Ankle Lines (from navel to both bony eminences of medial ankles); meanwhile, the malformation types of affected hip joint after functional changes were also considered to analyze the causes of coronal pelvic tilts to study the pattern of occurrence and to discuss the classification method of pelvic tilts which share common characteristics of this disease.Results:1. Clinical characteristics of pelvic tilts caused by hip joint diseases in 180 patients:(1) There were 37 patients whose pelvis tilted towards the affected limb, i.e. Type Ⅰ pelvic tilt Abdution contracture with flexion of different degrees occurred to the affected hip joints. Affected limb could bear load and walk with flexion and abduction of the affected hip joint, adduction of the contralateral limb and pelvic tilts towards the affected limb during walkings. Their disease progressions were relatively slow with less pain on hip-joints. Progressive and aggravated functional disorders of joint motions were major clinical manifestation. (2) There were 143 patients whose pelvis tilted towards the contralateral limb, i.e. Type Ⅱ pelvic tilt. Addution contracture with flexion of different degrees occurred to the affected hip joints. Affected limb could bear load and walk, and require support mostly. During walkings, flexion and abduction of the affected hip joint, adduction of the contralateral limb and pelvic tilts towards the affected limb appeared. Their disease progressions were relatively quick with hip-joint pain as during onset and the progression as the major clinical manifestations.2. SPSS20.0 software was adopted for statistical analysis. Chi-square test was adopted for the comparison of pelvic tilt type constituent ratio for different causes and different WHO pain grade. Fisher exact test was adopted when the requirements were not met. It can be concluded that, (1) Significant pelvic tilt constituent ratio difference existed for different causes (fisher exact value= 40.267, p<0.05) that cause correlates to pelvic tilts. Also, it is found that, patients with non-traumatic ischemic necrosis of femoral head, primary osteoarthritis of hit-joint, rheumatoid arthritis of hip-join and infectious hip osteoarthritis tended to be with Type Ⅱ pelvic tilts; (2) significant pelvic tilt constituent ratio difference existed for different pain Grades (fisher exact value= 96.739, p<0.05) that pain Grade correlates to pelvic tilts. Also, it is found that, patients with higher pain Grade tended to be with Type Ⅱ pelvic tilts.Conclusion:1 If the pain Grade is lower and the functional disorder of joint motions are progressive and aggravated, affected hip joint will mostly bend and show abduction contracture malformation with a pelvic tilt towards affected side; if the pain grade is higher during onsets and condition progression, affected hip joint will mostly bend and show adduction contracture malformation with a pelvic tilt towards contralateral side.2 Hip-joint diseases induced coronal pelvic tilt direction is same with the moving direction of body’s center gravity; the shortening of the affected limb cannot determine the direction of coronal pelvic tilt.3 According to the types of contracture malformation and the shortening conditions of the affected limbs, pelvic tilts are divided into the following groups: Type Ⅰ:Abduction contracture of the affected hip-joint Type ⅠA:with equal bilateral Spine-Ankle Lines Type ⅠB:with unequal bilateral Spine-Ankle Lines Type Ⅱ:Adduction contracture of the affected hip-joint Type ⅡA:with equal bilateral Spine-Ankle Lines Type ⅡB:with unequal bilateral Spine-Ankle Lines4 Coronal pelvic tilts induced by unilateral hip-joint diseases are mostly Type Ⅱ pelvic tilts.