ObjectiveTo compare the effect of percutaneous kyphoplasty (PKP) with different phases bone cement for treatment of osteoporotic vertebral compression fracture (OVCF).MethodsThe clinical data of 219 OVCF patients who treated with PKP and met the selection criteria between June 2016 and May 2018 were retrospectively analyzed. According to the different time of intraoperative injection of bone cement, they were divided into observation group [116 cases, intraoperative injection of polymethyl methacrylate (PMMA) bone cement in low-viscosity wet-sand phase)] and control group (103 cases, intraoperative injection of PMMA bone cement in low-viscosity wire-drawing phase). There was no significance in general date of gender, age, disease duration, body mass index, bone mineral density T value, fracture vertebral body, preoperative fracture severity of the responsible vertebral body, anterior height ratio of the responsible vertebral body, preoperative pain visual analogue scale (VAS) score, and Oswestry disability index (ODI) between the two groups (P>0.05). The VAS score and ODI score were used to evaluate the improvement of patients’ symptoms at immediate, 2 days, 3 months after operation and at last follow-up. At 1 day, 3 months after operation, and at last follow-up, X-ray film and CT of spine were reexamined to observe the distribution of bone cement in the vertebral body, bone cement leakage, and other complications. During the follow-up, the refracture rate of the responsible vertebral body and the fracture rate of the adjacent vertebral body were recorded.ResultsThe injection amount of bone cement in the observation group and control group were (4.53±0.45) mL and (4.49±0.57) mL, respectively, showing no significant difference between the two groups (t=1.018, P=0.310). Patients in both groups were followed up 6-18 months (mean, 13.3 months). There were 95 cases (81.9%) and 72 cases (69.9%) of the bone cement distribution range more than 49% of the cross-sectional area of the vertebral body in the observation group and the control group, respectively, showing significant difference in the incidence between the two groups (χ2=4.334, P=0.037). The VAS score and ODI score of the postoperative time points were significantly improved compared with those before operation (P<0.05), and there were significant differences among the postoperative time points (P<0.05). The VAS score and ODI score of the observation group were significantly better than those of the control group (P<0.05) at immediate, 2 days, and 3 months after operation, and there was no significant difference between the two groups at last follow-up (P>0.05). At 1 day after operation, the cement leakage occurred in 18 cases of the observation group (8 cases of venous leakage, 6 cases of paravertebral leakage, 4 cases of intradiscal leakage) and in 22 cases of the control group (9 cases of venous leakage, 8 cases of paravertebral leakage, 5 cases of intradiscal leakage). There was no significant difference between the two groups (P>0.05). During the follow-up, 5 cases (4.3%) in the observation group, 12 cases (11.7%) in the control group had responsible vertebral refracture, and 6 cases (5.2%) in the observation group and 14 cases (13.6%) in the control group had adjacent vertebral fracture, the differences were significant (χ2=4.105, P=0.043; χ2=4.661, P=0.031).ConclusionBone cement injection with wet-sand phase in PKP is beneficial for the bone cement evenly distributed, strengthening the responsible vertebral, relieving the short-term pain after operation, decreasing the rate of responsible vertebral refracture and adjacent vertebral fracture without increasing the incidence of relevant complications and can enhance the effectiveness.
ObjectiveTo investigate the occurrence, treatment, and effectiveness of peri-implant refracture after intramedullary nail fixation for intertrochanteric fractures.MethodsThe clinical data of 16 patients with peri-implant refracture after intramedullary nail fixation for intertrochanteric fractures who met the inclusion criteria between April 2014 and November 2019 were retrospectively analyzed. There were 7 males and 9 females with an average age of 78.4 years (range, 65-93 years). The 14 cases of initial intertrochanteric fractures were classified according to the classification of AO/Orthopaedic Trauma Association (AO/OTA): 5 cases of type A1, 7 cases of type A2, and 2 cases of type A3; the other 2 cases were intertrochanteric combined with subtrochanteric fractures (Seinsheimer type Ⅴ). According to the classification of peri-implant refracture which was proposed by Chan et al., there were 10 cases of type 1 (6 cases of type 1A, 3 cases of type 1B, 1 case of type 1C) and 6 cases of type 2 (4 cases of type 2A and 2 cases of type 2B). The average interval between refracture and initial surgery was 14.6 months (range, 1-52 months). The incidence of peri-implant refracture in short nail group (the length of intramedullary nail used in initial surgery≤240 mm) was 1.92% (11/573), while the incidence of long nail group (the length of intramedullary nail used in initial surgery≥340 mm) was 1.66% (5/301), showing no significant difference between the two groups (χ2=0.073, P=0.786). The peri-implant refractures were revised with extended intramedullary nail (5 cases) or fixed with additional limited invasive stabilization system (11 cases).ResultsThe average operation time was 115.8 minutes (range, 78-168 minutes) and the average intraoperative blood loss was 283.1 mL (range, 120-500 mL). One patient died of myocardial infarction at 3 months after operation, and the other 15 patients were followed up 9-46 months (mean, 16.8 months). The peri-implant refractures healed at 14-20 weeks (mean, 16.4 weeks) after operation. There was no complications such as incision infection, nonunion, internal fixator loosening and rupture, screw cutting-out, and the second refracture during the follow-up. At last follow-up, all injured limbs regained walking function, and the Hospital for Special Surgery (HSS) score was 56-92 (mean, 80.2). The results were classified as excellent in 2 cases, good in 10, fair in 2, and poor in 1, with the excellent and good rate of 80%.ConclusionStress concentration at the tip of initial intramedullary nail and distal interlocking screw aera is the main cause of peri-implant refracture after intramedullary nail fixation for intertrochanteric fractures. Revision with extended intramedullary nail or fixation with limited invasive stabilization system according to the length of initial intramedullary nail and the type of refracture can get satisfactory effectiveness.
ObjectiveTo compare the refracture risk between sandwich vertebrae and ordinary adjacent vertebrae, and to explore the risk factors related to refracture.MethodsRetrospective analysis was performed on the data of patients who received percutaneous vertebral augmentation (PVA) and formed sandwich vertebrae between April 2015 and October 2019. Of them, 115 patients were enrolled in the study. There were 27 males and 88 females with an average age of 73.9 years (range, 53-89 years). Univariate analysis was performed to analyzed the patients’ general data, vertebral augmentation related indexes, and sandwich vertebrae related indexes. Survival analysis was performed for all untreated vertebrae at T4-L5 of the included patients at the vertebra-specific level, and risk curves of refracture probability of untreated vertebrae between sandwich vertebrae and ordinary adjacent vertebrae were compared. Cox’s proportional hazards regression model was used to analyze risk factors for refracture.ResultsThe 115 patients were followed up 12.6-65.9 months (mean, 36.2 months). Thirty-seven refractures involving 51 vertebral bodies occurred in 31 patients. The refracture rate of 27.0% (31/115) in patients with sandwich vertebrae was significantly higher than that of 15.2% (187/1228) in all patients who received PVA during the same period (χ2=10.638, P=0.001). Univariate analysis results showed that there was a significant difference in the number of augmented vertebrae between patients with and without refractures (Z=0.870, P=0.004). However, there was no significant difference in gender, age, body mass index, whether had clear causes of fracture, whether had dual energy X-ray absorptiometry testing, whether the sandwich vertebra generated through the same PVA, puncture method, method of PVA, number of PVA procedures, number of vertebrae with old fracture, whether complicated with spinal deformity, bone cement distribution, and kyphosis angle of sandwich vertebral area (P>0.05). Among the 1 293 untreated vertebrae, there were 136 sandwich vertebrae and 286 ordinary adjacent vertebrae. The refracture rate of sandwich vertebrae was 11.3% which was higher than that of ordinary adjacent vertebrae (6.3%)(χ2=4.668, P=0.031). The 1- and 5-year fracture-free probabilities were 0.90 and 0.87 for the sandwich vertebrae, and 0.95 and 0.93 for the ordinary adjacent vertebrae, respectively. There was a significant difference between the two risk curves of refracture (χ2=4.823, P=0.028). Cox’s proportional hazards regression model analysis results showed that the sandwich vertebrae, thoracolumbar location, the number of the augmented vertebrae, and the unilateral puncture were significant risk factors for refracture (P<0.05).ConclusionThe sandwich vertebrae has a higher risk of refracture when compared with the ordinary adjacent vertebrae, and its 1- and 5-year fracture-free probabilities are lower than those of the ordinary adjacent vertebrae. However, the 5-year fracture-free probability of sandwich vertebrae is still 0.87, so prophylactic enhancement is not recommended for all sandwich vertebrae. In addition, the sandwich vertebrae, thoracolumbar location, the number of the augmented vertebrae, and the unilateral puncture were important risk factors for refracture.
Objective To analyze the causes and treatment of off target of the distal interlocking screws when short cephalomeduallry nails were installed through jig-guided targeting device, and to put forward the technical points to prevent off target. Methods Retrospective analysis of 9 patients with intertrochanteric fractures treated between July 2014 and June 2023 was conducted, in which off target occurred during the insertion of the distal interlocking screw by jig-guided targeting device in short cephalomedullary nailling (<24 cm). There were 1 male and 8 females, with an average age of 82.7 years (range, 73-94 years). There were 3 cases of type A1, 5 cases of type A2, and 1 case of type A3 according to 2018-AO/Orthopaedic Trauma Association (AO/OTA) fracture classification. As for the misaligned distal interlocking screw, six parameters were collected and analyzed, including the time of finding, the position, the type of passing through the cortical bone, the special circumstances during operation (such as the need to remove the intramedullary nail for reaming the diaphysis, hammering, etc.), the treatment, and the patient follow-up results. Results In the 9 patients, the off target of the distal interlocking screw was found in 7 cases during operation and in 2 cases after operation; the locking screw was located behind the nail in 7 cases and in front of the nail in 2 cases; the off target locking screw was passing tangentially in transcortical patern in 6 cases and in bicortical pattern through the medullary cavity in 3 cases. Three cases were attributed to the mismatch between the nail and the femur, two of which were attributed to the narrow femoral medullary cavity, one of which was attributed to the large anterolateral femoral bowing, and the other 6 cases were attributed to technical errors such as the loosening of the jig-guided targeting device, the tension of the fascia lata, and the blunt of the drill. In the 7 cases found during operation, the misaligned interlocking screw was removed first and the screw hole was left vacant, then in 2 cases, the interlocking screw was not used further; in 1 case, the distal dynamic hole was successfully inserted with a dynamic guide frame, and in 4 cases, the interlocking screw was successfully put after 2-3 attempts, leaving a large hole in the lateral cortex. No special treatment was performed in 2 cases found after operation. One patient was out of bed early after operation, 7 patients were in bed for 1 month, and 1 patient deteriorated to A3 type after operation and was in bed for 3 months. All the 9 patients were followed up 6-12 months, with an average of 8 months. Fracture healing was achieved in 8 patients. One patient with vacant interlocking screw had a secondary spiral fracture of the femoral shaft 3 months later, and was refixed with a long cephalomedullary nail and circlage wiring. Conclusion Distal interlocking screw off target is rare, but when it occurs, it leaves a large cortical hole in the osteoporotic femoral shaft, reducing bone strength; the use of precision instruments and attention to technical details can reduce this adverse phenomenon.