Objective:To investigate the clinical outcome of the coronal Y-shaped osteotomy in the apical vertebra for treating congenital complex rigid scoliosis.Methods:A retrospective analysis was conducted on 66 cases who underwent Y-shaped osteotomy treatment for congenital complex rigid scoliosis in the uppermost vertebra at the Department of Orthopedics,the Second Hospital of Shanxi Medical University from June 2007 to August 2020. There were 19 males and 47 females,with an age of (13.1±5.3) years(range:2 to 30 years).Classification of congenital scoliosis:25 cases (37.9%) were incomplete,13 cases (19.7%) were dysarthritic,and 28 cases (42.4%) were mixed. There were 25 cases (37.9%) with thoracic or rib malformations. 45 cases (68.2%) were complicated with spinal cord malformation.The main radiological indicators included Cobb angle of the curvature,Cobb angle of the local bend,apical vertebral translation (AVT),trunk shift (TS),thoracic trunk shift (TTS),radiographic shoulder height (RSH),coronal balance and sagittal vertebral axis. The preoperative,postoperative immediate,and last follow-up radiological indicators were collected and the operation time,blood loss,hospitalization time,and operation-related complications were recorded. Data were compared by repeated measure ANOVA and paired- t test. Results:All patients underwent surgery successfully. The duration of the first surgery was (221.4±52.8) minutes,and the blood loss during the first surgery was (273.2±41.8) ml. The length of the first hospital stay was (8.8±1.7) days.Unilateral fixation was performed in 19 cases (28.8%),while bilateral fixation was performed in 47 cases (71.2%). The fused segments were 7.5±2.9,and the vertebral pedicle screw density was (68.5±20.6)%. The follow-up time for the 66 patients was (36.7±17.0) months(range:24 to 102 months).The main curve Cobb Angle was improved from (58.5±18.9)°before surgery to (21.1±11.8)°after surgery,and was (23.6±15.3) ° at the last follow-up( F=273.957, P<0.01),with a correction rate of 66.2%. Segmental curve Cobb Angle was improved from (47.9±18.0)° to (16.0±11.3)° after surgery,and was (16.8±12.8) °at the last follow-up ( F=270.483, P<0.01)with a correction rate of 69.2%. The AVT,TS,TTS and RSH values improved significantly at the final follow-up (all P<0.05),while coronal balance and sagittal vertical axis were maintained without significant differences between pre-operation and post-operation(both P>0.05). A total of 5 patients underwent staged operation,all of which were residual scoliosis aggravated after the first stage of orthosis operation and had good prognosis after the second stage of operation. Conclusions:Y-shaped osteotomy for the treatment of congenital rigid scoliosis results in good clinical and radiological outcomes without serious complications. This procedure can be considered as an option for the treatment of congenital complex rigid scoliosis.

Objective:To investigate the clinical outcome of the coronal Y-shaped osteotomy in the apical vertebra for treating congenital complex rigid scoliosis.Methods:A retrospective analysis was conducted on 66 cases who underwent Y-shaped osteotomy treatment for congenital complex rigid scoliosis in the uppermost vertebra at the Department of Orthopedics,the Second Hospital of Shanxi Medical University from June 2007 to August 2020. There were 19 males and 47 females,with an age of (13.1±5.3) years(range:2 to 30 years).Classification of congenital scoliosis:25 cases (37.9%) were incomplete,13 cases (19.7%) were dysarthritic,and 28 cases (42.4%) were mixed. There were 25 cases (37.9%) with thoracic or rib malformations. 45 cases (68.2%) were complicated with spinal cord malformation.The main radiological indicators included Cobb angle of the curvature,Cobb angle of the local bend,apical vertebral translation (AVT),trunk shift (TS),thoracic trunk shift (TTS),radiographic shoulder height (RSH),coronal balance and sagittal vertebral axis. The preoperative,postoperative immediate,and last follow-up radiological indicators were collected and the operation time,blood loss,hospitalization time,and operation-related complications were recorded. Data were compared by repeated measure ANOVA and paired- t test. Results:All patients underwent surgery successfully. The duration of the first surgery was (221.4±52.8) minutes,and the blood loss during the first surgery was (273.2±41.8) ml. The length of the first hospital stay was (8.8±1.7) days.Unilateral fixation was performed in 19 cases (28.8%),while bilateral fixation was performed in 47 cases (71.2%). The fused segments were 7.5±2.9,and the vertebral pedicle screw density was (68.5±20.6)%. The follow-up time for the 66 patients was (36.7±17.0) months(range:24 to 102 months).The main curve Cobb Angle was improved from (58.5±18.9)°before surgery to (21.1±11.8)°after surgery,and was (23.6±15.3) ° at the last follow-up( F=273.957, P<0.01),with a correction rate of 66.2%. Segmental curve Cobb Angle was improved from (47.9±18.0)° to (16.0±11.3)° after surgery,and was (16.8±12.8) °at the last follow-up ( F=270.483, P<0.01)with a correction rate of 69.2%. The AVT,TS,TTS and RSH values improved significantly at the final follow-up (all P<0.05),while coronal balance and sagittal vertical axis were maintained without significant differences between pre-operation and post-operation(both P>0.05). A total of 5 patients underwent staged operation,all of which were residual scoliosis aggravated after the first stage of orthosis operation and had good prognosis after the second stage of operation. Conclusions:Y-shaped osteotomy for the treatment of congenital rigid scoliosis results in good clinical and radiological outcomes without serious complications. This procedure can be considered as an option for the treatment of congenital complex rigid scoliosis.

Objective: To discuss the feasibility and effectiveness of using micro-CT in bone-implant contact (BIC) evaluation in dogs, and to provide reference for clinical and scientific research. Methods: Bilateral mandibular second premolar and first molar of six male Beagle dogs were extracted. After 3 months′ healing, eight implants were placed in bilateral mandible of each dog, four on each side. Dogs were sacrificed at 2 weeks, 4 weeks and 8 weeks after implant placement, two on each time point. Samples were scanned with micro-CT and digitally reconstructed. Bone-implant interface was analyzed at different analysis regions (25, 50 and 100 μm from implants′ surface), different detection range models were obtained (each time point consists 48 models), and BIC was evaluated, and the results were counted as micro-CT₂₅, micro-CT₅₀, and micro-CT₁₀₀ groups. Then undecalcified slides were made (three slides for each sample) and stained with toluidine blue for observation and analysis of BIC using an optical microscope, and the results were counted as optical microscope groups. The advantages and disadvantages, evaluation efficiency and BIC of different methods were analyzed. Results: To evaluate BIC of single sample, it took about 90 minutes by micro-CT, which was much lower than the time of 14 days by optical microscope. The success rates of modeling of micro-CT₂₅, micro-CT₅₀, and micro-CT₁₀₀ groups all were 100.0% (48/48), and total success rate of micro-CT group was 100.0% (144/144). For optical microscope groups, the success rates of making slides 2, 4, 8 weeks were 89.6% (43/48), 93.8% (45/48) and 93.8% (45/48), respectively, and total success rates of optical microscope group was 92.4% (133/144). At 2, 4,8 weeks after implantation, BIC in micro-CT₂₅ group was significantly smaller than that in optical microscope group at the same time point (P<0.05). However, at 2, 4,8 weeks after implantation, BIC of the micro-CT₅₀ and micro-CT₁₀₀ groups showed no significant difference with optical microscope groups at the same time point (P>0.05). A significant correlation (P<0.001, each) was seen between slides and micro-CT (25, 50, 100 μm groups) concerning BIC (r=0.680, r=0.892, r=0.713), and error bias was -19.4%, -0.9%, 3.0%, respectively. The probability within the 95% limits of agreement were 97.9%. Conclusions Micro-CT is a faster, simpler and more efficient way to analyze BIC at the implant-bone interface than optical microscope observation. BIC analysis by selecting 50 μm from implants′ surface as analysis region using micro-CT is in consistent with that using the optical microscope.