[Application of high hip center technique in total hip arthroplasty in patients with Crowe typeâ ¡and â ¢ developmental dysplasia of hip and severe hip osteoarthritis].

OBJECTIVE: To explore the clinical efficacy of high hip center technique total hip arthroplasty （THA） for Crowe Ⅱand Ⅲ developmental dysplasia of hip （DDH） and severe hip osteoarthritis （HOA）. METHODS: From January 2018 to January 2020, 74 patients with Crowe typeⅡand Ⅲ DDH and severe HOA were admitted, and 37 cases of anatomical hip center reconstruction were taken as control group, including 7 males and 30 females, aged from 42 to 65 years old with an average of （58.40±4.98） years old, body mass index （BMI） ranged from 18 to 29 kg·m-2 with an average of （23.02±2.21） kg·m-2. Thirty-seven routine high hip center technical reconstruction were performed as study group, including 5 males and 32 females, aged from 41 to 65 years old with an average of （57.31±5.42） years old, BMI ranged from 18 to 29 kg·m-2 with an average of （23.14±2.07） kg·m-2. The patients presented with hip pain, limited function and range of motion, and gait instability before surgery. All patients underwent THA, the control group underwent intraoperative anatomical hip center reconstruction, and the study group underwent intraoperative high hip joint reconstruction. The perioperative indicators of the two groups were compared. The hip joint function, balance function and gait of the patients were evaluated before surgery, 3 months, 6 months, and 12 months after surgery. The length difference of both lower limbs, horizontal distance of rotation center, vertical distance of rotation center and femoral eccentricity were measured before operation and 1 year after operation. The incidence of complications in the two groups during the operation and postoperative follow-up was counted. RESULTS: The operation time of the study group was shorter than that of the control group, and the intraoperative blood loss was less than that of the control group （P<0.05）. After 12-months follow-up, 1 was lost to followvup in study group and 2 were lost to follow-up in control group. The Harris scores and Berg balance scale（BBS）, pace, stride frequency and single step length in the study group were higher than those in the control group at 3 months and 6 months after operation （P<0.05）；there was no statistically significant difference between the two groups in the indexes 12 months after operation （P>0.05）. The vertical distance of the center of rotation of the study group was greater than that of the control group 12 months after operation （P<0.05）, and there was no significant difference in the length difference of the lower limbs, the horizontal distance of the center of rotation, and the femoral eccentricity between two groups （P>0.05）. There were no complications in either group. CONCLUSION: The long-term effects of THA in patients with DDH and severe HOA were similar between the two central hip reconstruction methods, and the safety was good, and the high hip central reconstruction technique could shorten the operation time and reduce the amount of intraoperative blood loss.At the same time, it has certain advantages in early recovery of hip joint function, balance function and walking function of patients.

[Risk factors of adjacent vertebral refracture after percutaneous vertebroplasty for osteoporotic vertebral compression fractures in super-old patients].

OBJECTIVE: To analyze the risk factors for refracture of adjacent vertebrae after percutaneous vertebroplasty (PVP) in super-old patients with osteoporotic vertebral compression fractures(OVCFs). METHODS: A retrospective analysis was performed on 40 patients(age≥90 years) with OVCFs who underwent PVP between June 2012 and June 2019. There were 7 males and 33 females, age from 90 to 101 years old with an average of (94.6±1.6) years. Patients were divided into two groups according to whether adjacent vertebral refracture occurred after PVP. Among them, 20 patients occurred refracture after PVP (refracture group) and 20 patients did not occur it(control group). The general information, radiological data and pelvic parameters of the two groups were collected. The items included age, gender, body mass index (BMI), fracture site and bone mineral density(BMD) T-value, fracture to operation time, compression degree of injured vertebra, recovery degree of anterior edge of injured vertebra, bone cement injection amount, bone cement leakage, pelvic index(PI), pelvic tilt angle (PT), sacral angle(SS), et al. Factors that may be related to refracture were included in the single-factor study, and multivariate Logistic regression analysis was performed on the risk factors with statistical significance in the single-factor analysis to further clarify the independent risk factors for refracture of adjacent vertebral bodies after PVP. RESULTS: There were no significant differences in age, gender, fracture site, fracture to operation time, compression degree of injured vertebra and recovery degree of anterior edge of injured vertebra between two groups (P>0.05). There were significant differences in BMI, BMD T-value, bone cement injection amount and bone cement leakage rate between two groups(P<0.05). The PI and PT values of the refracture group were higher than those of the control group(P<0.05). There was no significant difference in SS between two groups (P>0.05). Multivariate Logistic regression analysis showed that decreased BMD T-value, bone cement leakage, increased PT and PI values increased the risk of recurrence of adjacent vertebral fractures in OVCFs (P<0.05). CONCLUSION: There are many risk factors for the recurrence of adjacent vertebral fractures in super-old patients with OVCFs. Patients with high PI and PT values may be one of the risk factors.