Subchondral insufficiency fractures of the medial tibial condyle are associated with medial meniscus extrusion: A retrospective observational study.

BACKGROUND: To the best of our knowledge, no prior studies have identified any risk factors for subchondral insufficiency fractures of the medial tibial condyle. This study aimed to explain relationships between subchondral insufficiency fractures of the medial tibial condyle and the meniscus status, lower extremity alignment, or osteoporosis. METHODS: This retrospective study included 325 consecutive patients whose chief complaint is knee joint pain and who had visited one institution between April 2016 and March 2021, of which 70 patients (8 men and 62 women) who had suspected subchondral insufficiency fractures of the medial tibial condyle had undergone magnetic resonance imaging and radiographic examination. These patients were divided into two groups based on the results of their magnetic resonance imaging: the insufficiency fracture group included 46 patients who had subchondral insufficiency fractures of the medial tibial condyle and the nonfracture group included 24 patients without fractures. The meniscus injury and medial meniscus extrusion (MME) were evaluated by using magnetic resonance imaging. The Kellgren-Lawrence grade, the femorotibial angle, and the percent mechanical axis (%MA) were evaluated with the use of knee radiographs. T-scores were also measured by using dual-energy X-ray absorptiometry with a bone densitometer. RESULTS: MME were significantly larger and the %MA was significantly smaller in the insufficiency fracture group than that in the nonfracture group. The prevalence of medial meniscus injuries and pathological MME were higher in the insufficiency fracture group than those in the nonfracture group. The prevalence of varus knee and osteoporosis did not vary remarkably different between the two groups. CONCLUSION: The patients who had insufficiency fractures of the medial tibial condyle tended to have medial meniscus extrusion.

Utility of a Navigated High-Speed Drill in Robotic-Assisted Screw Placement for Spine Surgery.

Purpose To elucidate the utility of a navigated high-speed drill used after the version upgrade in surgeries assisted by a spinal robotics system. Methods The subjects were 166 patients who underwent screw placement using a spinal robotics system between April 2021 to July 2023. A significant change during the study was the introduction of a navigated high-speed drill in 80 post-upgrade cases, aimed at improving drilling accuracy. Screw accuracy was analyzed using the Gertzbein and Robbins classification on postoperative CT scans. Screws placed before (pre-upgrade group: 718 screws in 86 cases) and after the system upgrade (post-upgrade group: 747 screws in 80 cases) were compared in terms of perfect accuracy and deviation rates. Results There were no significant differences in demographics or surgical details between the two groups. No significant differences were observed in the overall perfect accuracy rate and deviation rate (2.4% pre-upgrade vs. 2.0% post-upgrade) between the two groups. For the percutaneous pedicle screw (PPS), the perfect accuracy rate was significantly higher, and the deviation rate was significantly lower in the post-upgrade group (26.1% pre-upgrade vs. 4.4% post-upgrade). Notably, the post-upgrade group achieved 100% perfect accuracy and 0% deviation for the cortical bone trajectory screw (CBT) technique. Conclusions The introduction of the navigated high-speed drill did not significantly alter the overall perfect accuracy or deviation rates for robotic-assisted screw placement. However, its use did demonstrate improved outcomes in specific techniques such as PPS and CBT, indicating its potential value in addressing skiving in robotic-assisted minimally invasive surgeries.

Long-term changes in bone mineral density following adolescent idiopathic scoliosis surgery: a minimum 34-year follow-up.

PURPOSE: To investigate longitudinal changes in bone mineral density (BMD) in middle-aged female patients who underwent spinal fusion for adolescent idiopathic scoliosis (AIS). METHODS: The study subjects were 229 female patients who were diagnosed with AIS and underwent spinal fusion between 1968 and 1988. A two-step survey study was conducted on 19 female AIS patients. BMD, Z-scores, T-scores, and the prevalence of osteoporosis and osteopenia were compared between the initial (2014-2016) and second (2022) surveys. Correlations between the annual changes in Z-scores and T-scores with radiographic parameters, body mass index (BMI), and the number of remaining mobile discs were analyzed. RESULTS: BMD decreased significantly from the initial (0.802 ± 0.120 g/cm2) to the second survey (0.631 ± 0.101 g/cm2; p < 0.001). Z-scores decreased from 0.12 ± 1.09 to - 0.14 ± 1.04, while T-scores decreased significantly from - 0.70 ± 1.07 to - 1.77 ± 1.11 (p < 0.001). The prevalence of osteopenia and osteoporosis increased significantly from 36.8% to 89.5% (p = 0.002), but the increase in osteoporosis alone was not statistically significant (5.3% to 26.3%; p = 0.180). Moderate negative correlations were found between annual changes in Z-scores and both main thoracic (MT) curve (r = - 0.539; p = 0.017) and lumbar curve (r = - 0.410; p = 0.081). The annual change in T-scores showed a moderate negative correlation with the MT curve (r = - 0.411; p = 0.081). CONCLUSION: Significant reductions in BMD and an increased prevalence of osteopenia and osteoporosis were observed in middle-aged female AIS patients who had undergone spinal fusion. The decline in Z-scores in patients with AIS suggested that there was an accelerated loss of BMD compared with the general population. Larger residual curves could pose an added osteoporosis risk. Further research is needed to understand if the onset of osteoporosis in AIS patients is attributable to the condition itself or the surgical intervention.

Learning curves for robotic-assisted spine surgery: an analysis of the time taken for screw insertion, robot setting, registration, and fluoroscopy.

PURPOSE: The purpose of this study was to clarify the learning curve for robotic-assisted spine surgery. We analyzed the workflow in robotic-assisted spine surgery and investigated how much experience is required to become proficient in robotic-assisted spine surgery. METHODS: The data were obtained from consecutive 125 patients who underwent robotic-assisted screw placement soon after introducing a spine robotic system at a single center from April 2021 to January 2023. The 125 cases were divided into phases 1-5 of sequential groups of 25 cases each and compared for screw insertion time, robot setting time, registration time, and fluoroscopy time. RESULTS: There were no significant differences in age, body mass index, intraoperative blood loss, number of fused segments, operation time, or operation time per segment between the 5 phases. There were significant differences in screw insertion time, robot setting time, registration time, and fluoroscopy time between the 5 phases. The screw insertion time, robot setting time, registration time, and fluoroscopy time in phase 1 were significantly longer than those in phases 2, 3, 4, and 5. CONCLUSION: In an analysis of 125 cases after the introduction of the spine robotic system, the screw insertion time, robot setting time, registration time, and fluoroscopy time were significantly longer in the 25 cases in the period initially after introduction. The times were not significantly different in the subsequent 100 cases. Surgeons can be proficient in robotic-assisted spine surgery after their experience with 25 cases.

Comparison of Radiographic and Patient-Reported Outcomes After Surgery in Adolescent Idiopathic Scoliosis Between Robotics and Navigation: An Analysis Using Propensity Score Matching.

Purpose This study aimed to compare the radiographic and patient-reported outcomes after surgery in adolescent idiopathic scoliosis (AIS) between robotics and navigation using propensity score matching. Methods This retrospective study involved 50 patients undergoing posterior spinal fusion for AIS between October 2016 and August 2022, utilizing navigation or robotic systems, analyzing them using propensity score matching. The evaluations included assessments using X-ray, Scoliosis Research Society 22-Item (SRS-22) Questionnaire, and CT, considering variables such as age, gender, BMI, and Lenke type. Results Post matching, 13 cases each from robotics and navigation groups were compared. No significant differences were found in the demographic variables, preoperative X-ray parameters, and preoperative SRS-22 scores between the two groups. The robotics group demonstrated a higher perfect accuracy rate (94.0% vs. 84.7%, p=0.005) and a lower deviation rate in pedicle screw placements (1.6% vs. 4.1%, p=0.223). At one year postoperatively, there were no significant differences in the X-ray parameters between both groups. Likewise, no significant differences were found in each domain of SRS-22, but function, self-image, mental health, and satisfaction scores were numerically higher in the robotics group. Conclusion The application of a spinal robotic system in AIS surgery presented enhanced screw accuracy and lower deviation rates, compared to navigation, with no significant differences observed in the X-ray parameters and each domain of SRS-22 at one year postoperatively. This suggests that, to improve patient quality of life (QOL), it is essential for robotic-assisted spine surgery to focus not only on screw accuracy but also on the development of novel robotic-assisted techniques.

Nutritional Status Is Associated With Survival Following Spinal Surgery in Patients With Metastatic Spinal Tumors.

Background Preoperative and postoperative nutritional statuses are reported to influence the outcomes and complications of multidisciplinary treatment, including patient survival. However, a causal relationship between nutritional status and survival following spinal surgery has not been demonstrated in patients with metastatic spinal tumors. The present study was, therefore, designed to evaluate the correlation between the nutritional status and survival following spinal surgery in patients with metastatic spinal tumors. Methods Nutritional status was evaluated using the Japanese version of the modified Glasgow prognostic score (JmGPS), C-reactive protein-to-albumin ratio (CAR), prognostic nutrition index (PNI), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), which were calculated from the results of preoperative laboratory tests. The survival period was defined as the interval between the day preoperative data were obtained and the day of death. Results Data from 57 of 113 consecutive surgeries were retrieved. The CAR, JmGPS, and PNI were significantly correlated with the survival period (CAR, r = -0.576, P < 0.01; JmGPS, r = -0.537, P < 0.01; PNI, r = 0.316, P = 0.02). Furthermore, patients with 0 points on the JmGPS had significantly longer survival. Using receiver operating characteristic curves, CAR cutoffs of ≥0.880 and ≤0.220 were found to be optimal in predicting the 90- and 180-day postoperative survival, respectively. Conclusions The findings of the present study indicate that preoperative assessment of the JmGPS, CAR, and PNI has utility in estimating nutritional status and predicting survival following spinal surgery in patients with metastatic spinal tumors.

Safety of robotic-assisted screw placement for spine surgery: Experience from the initial 125 cases.

BACKGROUND: The present study aimed to evaluate the safety of robot-assisted screw placement in 125 cases after introducing a spinal robotics system and to identify the situations where deviation was likely to occur. METHODS: The subjects were 125 consecutive patients who underwent robotic-assisted screw placement using a spinal robotics system (Mazor X Stealth Edition, Medtronic) from April 2021 to January 2023. The 1048 screws placed with robotic assistance were evaluated. We investigated intraoperative adverse events of the robotics system and complications occurring within 30 days after surgery. We evaluated screw accuracy and deviation and compared them for vertebral levels, screw insertion methods (open traditional pedicle screw [Open-PS], cortical bone trajectory screw [CBT], percutaneous pedicle screw [PPS], and S2 alar iliac screw [S2AIS]), diagnosis, and phases of surgical cases. RESULTS: The deviation rate of robotic-assisted screw placement for spine surgery was 2.2%. Complications were reoperation due to implant-related neurological deficit in 0.8% and surgical site infection in 0.8%. There was significant difference in the deviation rate between vertebral levels. The deviation rate of the T1-T4 level was high at 10.0%. There was significant difference in the deviation rate between Open-PS, CBT, PPS, and S2AIS. The PPSs had a high deviation rate of 10.3%. The deviation rates were not significantly different between patients with and without deformity. The deviation rate did not change depending on the experience of surgical cases, and the deviation rate was favorable from the onset. CONCLUSION: Although the robotic-assisted screw placement was safe, we should be extra vigilant when placing screws in the upper thoracic region (deviation rate 10.0%) and when using PPSs (deviation rate 10.3%).

Balloon kyphoplasty combined with percutaneous pedicle screw (PPS) for the treatment of osteoporotic thoracolumbar fractures has minimum correction loss 2 years after surgery: compared to vertebroplasty using hydroxyapatite block combined with PPS.

BACKGROUND: Balloon kyphoplasty (BKP) is a useful treatment performed in patients with painful osteoporotic vertebral body fracture (OVF). However, in cases with large intra-vertebral clefts and cases with posterior spinal tissue damage, adjacent vertebral body fractures (AVFs), and cement migration may occur early after BKP, which may be a factor for poor results. In such cases, percutaneous vertebroplasty (PVP) combined with percutaneous pedicle screw (PPS) is useful treatment. This study compared BKP combined with PPS (BKP + PPS) compared to PVP using hydroxyapatite (HA) block combined with PPS (HAVP + PPS) for thoracolumbar OVF (TLOVF). METHODS: Twenty-eight patients who sustained painful TLOVFs without neurologic deficits underwent HAVP + PPS (group H, n=14) or BKP + PPS (group B, n=14). We evaluated time from injury to surgery, pre- and post-operative visual analogue scale (VAS) of low back pain, wedging angle of fractured vertebra, duration of operation, intraoperative blood loss, number of instrumented vertebra, and length of stay at hospital. RESULTS: Group B had significantly less surgery time and less blood loss during surgery. VAS of low back pain improved equally in both groups, but at 1 year and 2 years postoperatively, wedging angle of fractured vertebra progressed significantly in group H compared with group B. CONCLUSIONS: PPS fixation combined with percutaneous vertebral cement augmentation with BKP for OVF was suggested to be minimally invasive in the elderly patients. In addition, there is no correction loss of the fractured vertebral body after BKP + PPS, which is considered to be a useful surgical procedure.

Impact of the COVID-19 Pandemic on Middle-Aged and Older Patients With Adolescent Idiopathic Scoliosis Who Underwent Spinal Fusion: A Questionnaire-Based Survey.

Purpose To investigate the impact of the COVID-19 pandemic on middle-aged and older patients with adolescent idiopathic scoliosis (AIS) who underwent spinal fusion. Methods The subjects were 252 AIS patients who underwent spinal fusion between 1968 and 1988. The surveys were performed before the COVID-19 pandemic (a primary survey in 2014) and during the pandemic (a secondary survey in 2022). The self-administered questionnaires were mailed to the patients. We analyzed 35 patients (33 females and two males) who replied to both surveys. Results The pandemic had low impacts on 11 patients (31.4%). Two patients reported refraining from seeing a doctor because they were concerned about going to the clinic or hospital, eight reported that the pandemic impacted their work, and five reported fewer opportunities to go out (based on multiple-choice answers). Twenty-four patients reported that their lives were unaffected by the pandemic. No significant differences were detected between both surveys for Scoliosis Research Society-22 (SRS-22) in any domains (function, pain, self-image, mental, or satisfaction). The Oswestry Disability Index (ODI) questionnaires revealed a significant worsening of the survey during the pandemic compared with the survey before the pandemic. There was no significant difference in the impact of the pandemic between the ODI deterioration group (27.8%) and the ODI stable group (35.3%). Conclusion The COVID-19 pandemic had a low impact on 31.4% of middle-aged and older patients with AIS who underwent spinal fusion. The impact of the pandemic did not significantly differ between the groups with ODI deteriorations and the groups with stable ODI. The pandemic had a smaller impact on AIS patients at a minimum of 33 years after surgery.

Health-Related Quality of Life of Patients With Adolescent Idiopathic Scoliosis at Least 40 Years After Surgery.

STUDY DESIGN: Retrospective study. OBJECTIVE: The aim was to clarify the health-related quality of life (QOL) of patients who had adolescent idiopathic scoliosis (AIS) at a minimum of 40 years after surgery. SUMMARY OF BACKGROUND DATA: The postoperative health-related QOL of middle-aged patients with AIS has been reported to be good, but that of middle-aged and older patients with AIS has yet to be completely explored. MATERIALS AND METHODS: We included 179 patients with AIS who underwent spinal fusion(s) between 1968 and 1982. We conducted three surveys in 2009, 2014, and 2022. Patients self-administered both the Scoliosis Research Society-22 and the Roland-Morris Disability questionnaires three times (in 2009, 2014, and 2022) and the Oswestry Disability Index (ODI) questionnaire was self-administered in 2014 and 2022. We considered patients who responded to all three surveys in 2009, 2014, and 2022. RESULTS: For the Scoliosis Research Society-22 questionnaires, no significant differences were detected among the three time points (2009, 2014, and 2022) for total scores, function domain, pain domain, self-image domain, mental domain, or satisfaction domain. The results of the Roland-Morris Disability Questionnaire were also not significantly different among the surveys over time. The ODI questionnaires revealed a significant worsening of the 2022 results compared with the 2014 results. Eight patients (29.6%) who had an ODI deterioration of 10% or more had numerically fewer mobile lumbar disks than those with <10% deterioration of the ODI, although the difference did not reach statistical significance. CONCLUSION: Among patients with AIS who underwent spinal fusion(s) between 1968 and 1982, we found health-related QOL to be maintained over the last 13 years. Relatively good QOL was appreciated in this population of patients who are now middle-aged and older.

Accuracy of computer-assisted pedicle screw placement for adolescent idiopathic scoliosis: a comparison between robotics and navigation.

PURPOSE: To compare the accuracy of pedicle screw placement in adolescent idiopathic scoliosis (AIS) between robotics and navigation and clarify the factors that cause screw deviation when robotics is used. METHODS: Fifty consecutive patients who underwent posterior spinal fusions with computer-assisted pedicle screw placement including robotics and navigation for AIS were included. A total of 741 pedicle screws (250: Robot group, 491: Navi group) were evaluated on postoperative CT images. A rate of penetration of ≥ 2 mm was calculated as the deviation rate. After propensity score matching, we examined vertebral levels, the distance from the reference frame (RF), and the pedicle channel grade as factors for deviation. RESULTS: The deviation rate was significantly lower in the Robot group than in the Navi group (Robot group: 1.6%, Navi group: 7.5%). After propensity score matching, 22 cases were extracted. At T5-T8, the deviation rate of the Robot group was significantly lower than that of the Navi group. In the Robot group, the T2-T4 deviation rate was significantly higher than at the other vertebral levels. The distance from the RF didn't affect the deviation rate. The deviation rate of pedicle channel Grade 4 (inner diameter of less than 1 mm) was significantly higher than for the other grades. CONCLUSION: The deviation rate of robotics was 1.6%, lower than that of navigation. The narrow pedicles with an inner diameter of less than 1 mm (deviation rate: 22.2%) and the upper thoracic level (deviation rate: 14.3%) were factors related to screw deviation even when using robotics.

Accuracy of robotic-assisted pedicle screw placement comparing junior surgeons with expert surgeons: Can junior surgeons place pedicle screws as accurately as expert surgeons?

BACKGROUND: The purpose of this study was to verify whether a spine robotic system was useful for junior surgeons. METHODS: Twenty-seven patients underwent posterior spinal fusion with open surgery using a spine robotic system (Mazor X Stealth Edition, Medtronic Inc., Dublin, Ireland) from April to August 2021. Pedicle screw insertions were performed by five surgeons. The surgeon and insertion time were recorded for each pedicle screw. Two surgeons who are board-certified spine surgeons by the Japanese Society for Spine Surgery and Related Research (JSSR) were defined as the expert surgeon group. Three surgeons who were training to acquire qualifications as JSSR board certified spine surgeons were defined as the junior surgeon group. In postoperative CT images, the deviation of 255 pedicle screws was evaluated using the Gertzbein-Robbins (GR) grades. RESULTS: In the expert surgeon group, the GR grades were Grade A for 79 screws (90.8%), Grade B for 6 (6.9%), Grade C for 2 (2.3%), and 0 (0%) for Grades D and E. I In the junior surgeon group, the GR grades were Grade A for 162 screws (96.4%), Grade B for 6 (3.6%), and 0 (0%) for Grades C, D, and E. There was no significant difference in the deviation rate between surgeon groups (p = 0.08). The mean insertion times were 174.5 ± 83.0 s in the expert surgeon group and 191.0 ± 111.0 s in the junior surgeon group. There was no significant difference in the insertion time between surgeon groups (p = 0.22). CONCLUSIONS: There were no significant differences in the deviation rate and the insertion time of robotic-assisted pedicle screw placement between expert surgeons and junior surgeons who were training to acquire qualifications as JSSR board certified spine surgeons. Robotic-assisted pedicle screw placement can be effectively employed by junior surgeons.

Comparison of foot posture and foot muscle morphology between lifesaver athletes and healthy adults.

This study aimed to compare the foot muscle morphology and foot posture between healthy adults and lifesavers in sandy beach sports. The participants included 15 lifesaver athletes and 15 healthy adults. Using a non-contact three-dimensional foot measurement device, the foot length, width, and arch height of the right foot were measured while standing and sitting without back support, and the transverse arch length ratio and arch height index were subsequently calculated. Muscle cross-sectional area was measured using an ultrasound imaging device. Muscle cross-sectional areas, arch height, foot width, arch height index, and transverse arch length ratio were larger in the lifesaver than in the healthy adult group. Lifesavers had higher arches and more developed intrinsic and extrinsic muscles than healthy adults. Performing physical activity while barefoot on sandy beaches may effectively develop the foot intrinsic and extrinsic muscles and raise the arch.

Somnolence and Dizziness During Mirogabalin Treatment in Patients With Neuropathic Pain Related to Lumbar Disease Who Switched From Pregabalin: A Retrospective Study.

STUDY DESIGN: Multicenter retrospective study. OBJECTIVES: To investigate adverse events (AEs) in patients with neuropathic pain related to lumbar disease who switched to mirogabalin from pregabalin. METHODS: This study surveyed the records of 82 patients with peripheral neuropathic leg pain related to lumbar disease who switched to mirogabalin from pregabalin. We evaluated AEs associated with pregabalin and mirogabalin, the continuation rate of mirogabalin, and the pain-relieving effect at 4 weeks after switching from pregabalin to mirogabalin. We compared patients who switched due to lack of efficacy (LoE group) and patients who switched due to AEs (AE group). RESULTS: The incidence rates of somnolence and dizziness with pregabalin were 12.2% and 14.6%, respectively, while the incidence rates with mirogabalin were reduced to 7.3% for somnolence and 4.9% for dizziness. The incidence of AEs with pregabalin was significantly higher in the AE group (LoE group: 11.1%, AE group 100%), especially for somnolence (LoE group: 3.2%, AE group: 47.1%) and dizziness (LoE group: 4.8%, AE: 52.9%). After switching, the incidences of AEs with mirogabalin were not significantly different between the 2 groups (LoE group: 15.9%, AE group: 23.5%), including for somnolence (LoE group: 7.9%, AE group: 5.9%) and dizziness (LoE group: 4.8%, AE group: 5.9%). There were no significant differences in continuation rate of mirogabalin or the pain-relieving effect between groups. CONCLUSIONS: The patients who experience somnolence and dizziness with pregabalin might be able to continue safely receiving treatment for their pain by switching to mirogabalin.

Robotics is useful for less-experienced surgeons in spinal deformity surgery.

PURPOSE: To verify whether robotics was useful for surgeons who had less experience with spinal deformity surgery. METHODS: A retrospective review was conducted of 70 consecutive patients who underwent robotic-assisted pedicle screw placements with open procedures using a spine robotic system (Mazor X Stealth Edition) at a single institution from April 2021 to April 2022. Gertzbein-Robbins grades were used to assess the deviation of the 599 pedicle screws in the postoperative CT images. The rate of Grade A was considered the perfect accuracy rate, and the rate of Grades C, D, and E was calculated as the deviation rate. The perfect accuracy rate and deviation rate were compared between the spinal deformity and the non-deformity groups. The perfect accuracy rate, deviation rate, and screw insertion time were compared in the spinal deformity cases between the expert surgeon group and the less-experienced surgeon group. RESULTS: The deviation rate of the spinal deformity group was higher than that of the non-deformity group even though there was no statistically significant difference (spinal deformity group: 2.3%, non-deformity group: 1.2%, p = 0.350). In the spinal deformity cases, there was no significant difference in the perfect accuracy rate between the expert surgeon group and the less-experienced surgeon group, but the deviation rate was significantly lower in the less-experienced surgeon group (expert surgeon group: 5.0%, less-experienced surgeon group: 0%, p = 0.008). The screw insertion time was significantly shorter in the less-experienced surgeon group. CONCLUSION: Robotics is particularly useful for surgeons with less experience in spinal deformity surgery.

The Learning Curve of Robotic-Assisted Pedicle Screw Placements Using the Cumulative Sum Analysis: A Study of the First 50 Cases at a Single Center.

Introduction: The purpose of this study was to clarify how many cases surgeons need to experience to pass the learning phase of robotic-assisted spine surgery using the cumulative sum (CUSUM) analysis. Methods: A retrospective review was conducted on the initial 50 consecutive patients who underwent robotic-assisted pedicle screw placements with open procedures using a spine robotic system (Mazor X Stealth Edition) at a single center from April 2021 to January 2022. There were 19 male and 31 female patients with a mean age of 58.7 (range, 13-86) years. To split the surgeries into the early and late phases using the CUSUM analysis of screw insertion time, we compared the screw insertion time, the robot setting time, the registration time, and the operation time in the early and late phases. Results: The screw insertion time, the robot setting time, and the registration time declined as the number of surgical cases increased. The operation time did not decline as the number of surgical cases increased. The learning curve for screw insertion time can be separated into two stages based on the CUSUM analysis. The first 23 cases were in the early phase, and the later 27 cases were in the late phase. The mean screw insertion time was reduced from 3.2 min in the first 23 cases to 2.7 min in the subsequent 27 cases. The robot setting time and registration time in the late phase were also significantly shorter than those in the early phase. Conclusions: The screw insertion time, robot setting time, and registration time decreased with experience. After 23 cases, surgeons passed the learning phase of robotic-assisted spine surgery and became more proficient.

Diagnosis of Spinal Infection with Alpha-defensin Lateral Flow Test: A Preliminary Report.

Introduction: The alpha-defensin lateral flow test has been used in periprosthetic joint infection as a diagnostic support tool because of its simplicity and speed. However, the test has not been used to diagnose spinal infections. The purpose of this study was to investigate the efficacy of the alpha-defensin lateral flow test for diagnosing spinal infections. Methods: The subjects were 11 patients who were suspected of having spinal infections from October 2019 to August 2021 and underwent biopsies at a single institution. There were nine male and two female patients, with an average age of 60.7 (14-87) years. For diagnosing infection, the patient's consent for biopsy was obtained, and the sample was collected by computed tomography-guided aspiration biopsy or open biopsy at the site considered to be a possible abscess. The samples were subjected to a bacterial culture test, an acid-fast bacillus culture test, and an alpha-defensin lateral flow test (SynovasureⓇ lateral flow test; Zimmer Biomet, IN, USA). Results: Of the 11 suspected spinal infections, the alpha-defensin lateral flow test was positive in 8 cases, negative in 2 cases, and undeterminable in 1 case. Of the 10 cases excluding the undeterminable case, the definitive diagnosis was 9 cases of spinal infection (spondylitis: 6 cases, spinal implant infection: 3 cases) and 1 case of vertebral body fracture. The alpha-defensin lateral flow test demonstrated a sensitivity of 88.9%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 50%. The biopsy sample culture test demonstrated a sensitivity of 77.8%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 33.3%. Conclusions: We suggested that the alpha-defensin lateral flow test might be useful as a diagnostic support tool for spinal infections.

Screw Insertion Time, Fluoroscopy Time, and Operation Time for Robotic-Assisted Lumbar Pedicle Screw Placement Compared With Freehand Technique.

Introduction The purpose of this study was to clarify the superiority of robotic-assisted lumbar pedicle screw placement in terms of screw insertion time, fluoroscopy time, and operation time. Methods The subjects were 46 patients who underwent a posterior lumbar interbody fusion with an open procedure for lumbar degenerative disease from April 2021 to February 2022. The robot group contained 29 cases of screw insertion using a spine robotic system (Mazor X Stealth Edition, Medtronic Inc., Dublin, Ireland). The freehand group contained 17 cases of screw insertion with the freehand technique utilizing the conventional C-arm image guidance. The screw insertion time, fluoroscopy time, and operation time were compared between the robot and the freehand group. Results The screw insertion time did not differ significantly between the two groups (robot group: 179.0 ± 65.2 sec; freehand group: 164.2 ± 83.4 sec; p = 0.507). The fluoroscopy time was significantly shorter in the robot group (robot group: 28.3 ± 25.8 sec; freehand group: 67.5 ± 72.8 sec; p = 0.011). The fluoroscopy time per segment was also significantly shorter in the robot group (robot group: 17.8 ± 23.0 sec; freehand group: 60.2 ± 74.8 sec; p = 0.007). The operation time was significantly longer in the robot group (robot group: 249.6 ± 72.5 min; freehand group: 195.8 ± 60.1 sec; p = 0.013), but the operation time per segment did not differ significantly between the two groups (robot group: 144.1 ± 39.0 min; freehand group: 159.7 ± 34.4 min; p = 0.477). Conclusions The screw insertion time and operation time per segment were similar when employing the spine robotic system compared to the freehand technique; however, the fluoroscopy time was shorter. The fluoroscopy time per segment in the robot group was 29.6% of the time of the freehand group using the C-arm. The surgeon's radiation exposure is thought to be decreased since the spine robotic system shortens the fluoroscopy time.

Supramalleolar Lateral Opening-Wedge Osteotomy in Conjunction With Progressive Collapsing Foot Deformity Reconstruction for PCFD With Ankle Instability.

BACKGROUND: Reconstruction of progressive collapsing foot deformity (PCFD) with ankle instability (PCFD class E) remains a substantial challenge to orthopaedic surgeons. We report the outcomes of PCFD class E treated by means of a relatively standard PCFD foot reconstruction approach with the addition of a supramalleolar lateral opening-wedge osteotomy. METHODS: We conducted a retrospective study of 13 patients (15 ankles) who underwent this procedure for PCFD class E between 2010 and 2021. Mean follow-up time was 3.8 (range, 2-6.3) years. Clinical assessment was based on the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale as well as a Self-Administered Foot Evaluation Questionnaire (SAFE-Q). Radiographic assessments, including identification of the mechanical ankle joint axis point and a modified valgus Takakura-Tanaka osteoarthritis grade, were recorded. RESULTS: The mean JSSF score improved significantly from 45.2 preoperatively to 83.9 postoperatively (P < .001). SAFE-Q scores at the final follow-up were 70.1 for the pain and pain-related subscale, 75.4 for the physical functioning and daily living subscale, 83.0 for the social functioning subscale, 74.4 for the shoe-related subscale, and 78.1 for the general health and well-being subscale. Radiographic measurements showed improvement in the tibiotalar tilt angle (average improvement: 5.4 degrees); orientation of the talus joint line relative to the ground (average improvement: 14.0 degrees); anteroposterior talus-first metatarsal angle (average improvement: 11.2 degrees), talonavicular coverage angle (average improvement: 21.6 degrees), and lateral talus-first metatarsal angle (average improvement: 17.0 degrees). Postoperatively, the mechanical ankle joint axis point moved medially for all patients and into the medial half of the ankle joint for 7 patients. The modified osteoarthritis stage improved postoperatively in most cases. CONCLUSION: In this select and relatively small group of patients who had a supramalleolar lateral opening-wedge osteotomy combined with PCFD reconstruction, we measured general improvement in JSSF scores and radiographic variables. Long-term durability of the procedure remains unknown. This procedure may be an option for preserving the ankle joint in treatment of PCFD class E with osteoarthritis of the ankle. LEVEL OF EVIDENCE: Level IV, therapeutic.

The Diagnostic Accuracy of MRI to Evaluate Acute Lisfranc Joint Injuries: Comparison With Direct Operative Observations.

BACKGROUND: Early diagnosis is important in patients with Lisfranc joint injury to avoid subsequent complications. As the ligaments in the Lisfranc joint are relatively small and course obliquely, isotropic 3-dimensional (3D) magnetic resonance imaging (MRI) can be beneficial to evaluate ligament injury. The purpose of this study was to investigate the diagnostic accuracy of MRI, including isotropic 3D MRI for acute injury of the Lisfranc joint, especially of the interosseous C1-M2 ligament (Lisfranc ligament), the dorsal C1-M2 ligament (dorsal ligament), and the interosseous C1-C2 ligament, compared with direct operative observations. METHODS: This retrospective review identified 27 patients who had undergone MR examination for acute Lisfranc joint injury followed by surgery. We reviewed the operative reports that described the Lisfranc, dorsal, and interosseous C1-C2 ligaments. All patients underwent an MRI, including a 2D oblique plane image parallel to the Lisfranc ligament and an isotropic 3D MRI. An image analysis of the integrity of the 3 ligaments and other associated injuries was performed. The diagnostic accuracy of MRI was analyzed using operative findings as a reference standard. RESULTS: Lisfranc and dorsal ligament injuries were identified on MRI in all patients. MRI depicted disruption of the interosseous C1-C2 ligament in 12 patients. MRI diagnostic accuracy for detection of Lisfranc, dorsal, and interosseous C1-C2 ligaments was 100% (95% CI 0.82-1.0), 74% (95% CI 0.54-0.89), and 70% (95% CI 0.50-0.86), respectively. CONCLUSION: MRI with oblique planes parallel to the Lisfranc ligament and isotropic 3D MRI was reliable for detecting Lisfranc ligament injury, whereas MRI findings of the dorsal and interosseous C1-C2 ligaments were less consistent with operative observations. LEVEL OF EVIDENCE: Level IV, case series.