[Impact of proximal femoral shape on leg length discrepancy after total hip arthroplasty].

OBJECTIVE: To investigate the effect of different proximal femoral shapes on leg length discrepancy(LLD) after total hip arthroplasty(THA). METHODS: Total 131 patients with osteoarthritis or osteonecrosis received unilateral biological total hip arthroplasty from June 2013 to June 2019. All patients' age, sex, side and pelvis anteroposterior digital radiography were retraspectively analyzed. There were 69 males and 62 females, 57 cases of left hip and 74 cases of right hip. The age ranges from 25 to 89 with an average age of 62 years. There were 48 cases of osteoarthritis and 83 cases of osteonecrosis. In this study, femoral cortical index (FCI) was used as the classification of proximal femoral shape, and bilateral lower limb length differences were measured by preoperative and postoperative pelvis anteroposterior digital radiography. Grouping according to FCI:> 0.6 was Dorr A group, 0.5 to 0.6 was Dorr B group, <0.5 was the Dorr C group, and the relationship between proximal femur morphology and the leg length discrepancy after total hip arthroplasty was determined. RESULTS: The postoperative average FCI was(0.56±0.08) mm and the median LLD was 5.10 mm (IQR -1.00 to 8.80 mm). Three groups were divided according to the level of FCI, and there were no statistically significant differences in gender, age, side, diagnosis and intraoperative fracture rate distribution among three groups. FCI>0.6, the postoperative LLD was 6.30 mm (IQR 1.00 to 10.95 mm). When FCI was 0.5 to 0.6, the postoperative LLD was 5.85 mm(IQR-0.55 to 8.90 mm). FCI<0.5, the postoperative LLD was 1.95 mm(IQR -2.50 to 6.68 mm). LLD comparison of different proximal femoral shape was statistically significant (P<0.05). CONCLUSION: High FCI increases the risk of lower extremity prolongation after surgery on the affectedside, while low FCI reduces the risk of lower extremity prolongation after surgery on the affected side. The surgeon can assess the shape of the proximal femur of the patient preoperatively and inform the patient in advance of possible changes in leg length of both lower extremities after total hip replacement.

[Imageology study of correlation loss and its related factors after short-segment pedicle screw reduction and fixation for lumbar fractures].

OBJECTIVE: To analyze the correction loss after posterior segmental fixation for lumbar spine fractures and explore the related image factors. METHODS: Posterior short-segment fixation was received in 48 patients with L2-L4 fractures. There were 32 males and 16 females, with ages of 23 to 60 (45.98±8.20) yeaes. The anterior vertebrae height (AVH), vertebral wedge angle (VWA) of the injured vertebra and local kyphosis angle (LKA) were measured before operation, 1 week after operation and the final follow-up. The loss of segmental discal angle (LoSDA), LKA(LoLKA), AVH(LoAVH) were calculated between 1 week postoperative and the last follow up. Preoperative load-sharing scores(LSS), TLICS scores, and adjacent intervertebral disc injuries (IDIs) were assessed. Then the correlation between the age, follow up time, LSS, TLICS, IDIs and the correction loss was analyzed. RESULTS: The average follow-up was 12 to 18 (16.13±5.39) months. LKA, AVH and VWA at 1 week postoperative and those at the final follow up, were significantly improved compared with those preoperative (P<0.05). In the final follow up, the average LKA(5.70±3.17)° and AVH(4.31±5.95)% correction loss were observed compared with those 1 week postoperative(P<0.05). Otherwise the lose of VWA was not obvious(P>0.05). Univariate analysis showed that the SDA (r=0.706, 0.579, 0.449) and LKA(r=0.715, 0.566, 0.502) correction loss were aggravated with the increase of LSS, TLICS and IDIs, and AVH (r=-0.325, -0.219) correction loss was aggravated with the increase of LSS and TLICS(P<0.05). Multivariate analysis showed that increased LSS scores were all risk factors for segmental disc angle (SDA) loss, LKA correction loss, and AVH correction loss (P<0.05). CONCLUSION: The angle of adjacent intervertebral discs and anterior height of injured vertebrae were lost statistically after posterior short-segment pedicle screw treatment for lumbar fractures, and multivariate analysis showed that all of them were correlated with load-sharing score.

[Analysis of hidden blood loss and its risk factors in the treatment of osteoporotic vertebral compression fractures with PVP].

OBJECTIVE: To investigate the influencing factors of hidden blood loss (HBL) during the treatment of percutaneous vertebroplasty (PVP). METHODS: The clinical data of 125 patients with osteoporotic vertebral compression fractures (OVCFs) treated with percutaneous vertebroplasty from March 2016 to December 2017 were retrospectively analyzed. All patients underwent X rays of the AP and lateral lumbar spine, double oblique, and dynamic positions. Lumbar spine CT, MRI, and dual energy X ray bone densitometer (DXA) were used to confirm the diagnosis. There were 55 males and 70 females, 10 cases of thoracic vertebrae, 89 cases of thoracolumbar vertebrae, 26 cases of lumbar vertebrae, 87 cases with single segment, 29 cases with double segment,and 9 cases with 3 segments. The vertebral compression height ratios of 67 patients were less than 1 / 3, and the ratios for 41 patients were from 1 / 3 to 2 / 3,for 17 patients were more than 2 / 3. Blood routine examination were performed before and 3 days after surgery to analyze hidden blood loss and to explore its risk factors. RESULTS: The average hidden blood loss was (317±156) ml in 125 patients. Multiple linear regression analysis revealed a history of diabetes(P=0.011),surgical segments(P=0.036),number of segments (P<0.001),vertebral height loss rate (P=0.002),vertebral height recovery rate (P<0.001) and bone cement leakage rate (P=0.003) were positively correlated with hidden blood loss. Moreover,it was found that the blood loss was higher in those with higher vertebral height loss rate than in those with lower vertebral height loss rate, and the blood loss was higher in those with good vertebral height recovery than those with poor vertebral height recovery. Additionally,the cement leakage was also an important factor in increasing hidden blood loss. However,there was no significant correlation between bone mineral density(P=0.814) or history of hypertension(P=0.055) and hidden blood loss. CONCLUSION: Patients with OVCFs have a large amount of hidden blood loss after PVP treatment, which needs attention. At the same time, the history of diabetes, surgical segments, number of segments, bone cement leakage rate, vertebral height loss rate and vertebral height recovery rate are the risk factors for hidden blood loss.

Rapamycin could increase the effects of melatonin against age-dependent bone loss.

Previous studies have demonstrated the beneficial effect of melatonin (MEL) on bone tissue and bone metabolism. Rapamycin (RAP) promotes osteoblast proliferation and inhibits osteoclast proliferation, and positively affects bone regeneration; however, reports about effects of RAP on bone loss for aged female rats with MEL administration are limited. This study investigated the impact of treatment with RAP on bone loss for aged female rats with MEL administration. Female Sprague-Dawley rats weighing approximately 520 g were randomly divided into 3 groups of 10: group CON, group MEL and group MEL + RAP and received saline, MEL, RAP plus MEL treatment until death at 12 weeks, respectively. The results of maintaining bone mass and bone strength with RAP plus MEL administration were evaluated by histology, microcomputerized tomography (Micro-CT), gene expression analysis and biomechanical testing. Results from this study indicated that MEL + RAP had stronger effects on the prevention and treatment of osteoporosis than MEL administration. Administration of MEL + RAP produced the strongest effects on bone parameters and strength for distal femurs and regulation of OPG/RANKL signalling pathway-related gene expression. These results seemed to indicate that RAP could increase the effects of MEL on age-dependent bone loss.