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.

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.

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.

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.

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.

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%).

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.

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.

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.

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.

Accuracy and Screw Insertion Time of Robotic-Assisted Cortical Bone Trajectory Screw Placement for Posterior Lumbar Interbody Fusion: A Comparison of Early, Middle, and Late Phases

Introduction The purpose of this study was to evaluate robotic-assisted cortical bone trajectory (CBT) screw placement. Early, middle, and late phases of robotic-assisted CBT screw placement were compared for accuracy and screw insertion time by comparing time and accuracy in every phase.  Methods A retrospective review was conducted on the initial 40 patients who underwent spinal fusion using CBT screws in one institution from September 2021 to September 2022 utilizing a spine surgery robot system (Mazor X Stealth Edition, Medtronic Inc., Dublin, Ireland). The inclusion criterion was one- or two-level posterior lumbar interbody fusion (PLIF). Exclusion criteria were 1) patients who underwent posterior-lateral fusion in other segments, 2) patients who underwent additional decompression in other segments, 3) patients who underwent reoperation, and 4) patients with spondylolysis. The deviation of the CBT screw was evaluated on computed tomography (CT) one week after surgery using the Gertzbein-Robbins grade system. The rate of Grade A was considered the perfect accuracy rate, and the rate of penetration of 2 mm or more (Grades C, D, and E) was calculated as the deviation rate. To assess the learning curve, patients were divided into three groups. The first 10 cases were in the early phase group, the subsequent 10 cases were in the middle phase group, and the last 10 cases were in the late phase group. We compared the perfect accuracy rate, deviation rate, operative time, operative time per segment, intraoperative blood loss, registration time, and screw insertion time among the three groups. Results Thirty patients met the criteria. Overall, the perfect accuracy (Grade A) rate of the screw was 95.3% and the deviation rate was 1.4%. The perfect accuracy rate was 90.4% in the early phase, 95.5% in the middle phase, and 100% in the late phase. The deviation rate was 3.8% in the early phase, 0% in the middle phase, and 0% in the late phase, and there was no statistically significant difference between the three groups. Among the three groups, the operative time, the operative time per segment, the intraoperative blood loss, and the registration time were not significantly different. There was no significant difference in the screw insertion time among the three groups, but it decreased with experience (early phase: 156.9 ± 54.7 sec, middle phase: 139.9 ± 41.6 sec, and late phase: 106.4 ± 39.9 sec, p=0.060). The screw insertion time of the late phase tended to be shorter than that of the early phase (p=0.052). Conclusions The deviation rate of robotic-assisted CBT screw placement with one- or two-level PLIF was 1.4%, which was highly accurate. The deviation rate was 3.8% in the early phase, 0% in the middle phase, and 0% in the late phase. Although the deviation rate was low even in the early period, the screw insertion time in the early 10 cases tended to be longer than that in the late 10 cases. After passing the experience of 10 cases, this study concluded that robotic-assisted CBT screw placement was proficient.

Peritalar Configuration Following Fusion in Varus Ankle Osteoarthritis: A 3D Weight Bearing CT Analysis

Category:

Ankle Arthritis; Ankle

Introduction/Purpose:

In varus-type osteoarthritis of the ankle (VAOA), it is known that the subtalar joint compensates in valgus/eversion for the malalignment of the tibiotalar joint. However, previous studies were mainly based on X-ray measurements and did not take into account peri-talar changes that extend to the subtalar and Chopart joints. Furthermore, the effect on peritalar compensation when tibio-talar arthrodesis is performed is still unclear. Distance Mapping (DM) is a technology that can produce a 3D point-to-point distance map of joint interactions from cone beam weight bearing CT (WBCT) images. The purpose of this study was to quantify the peri-talar changes that occur when the tibiotalar joint is fused. We hypothesized that talar varus would improve and that the Chopart/Subtalar joint complex would present compensatory varus/inversion.

Methods:

The subjects were 14 patients (15 feet) who underwent arthrodesis for VAOA at our institution. The average postoperative follow-up period was 6.6 months. Foot alignment (Foot Ankle Offset (FAO)) was measured from WBCT datasets pre and postoperatively. The pre to post op shift vectors of the weighted distance maps center points were measured for the tibiotalar, subtalar, calcaneocuboid and talonavicular joints. Statistical analysis was performed by paired T-test, and the significance level set at p<0.05.

Results:

FAO improved significantly from preoperative -12.9 +-7.4 % to postoperative -6.4 +-3.9 %. The DM vectors were 4.9 +-2.8 mm (lateral direction) for the tibiotalar joint, 0.86 +-0.93 mm (posterior) for the subtalar joint and 4.9 +-2.6 mm (plantar- medial) for the talonavicular joint.

Conclusion:

The main finding in this study was that foot alignment was improved following tibiotalar arthrodesis with peritalar compensation, more so in the talonavicular than in the subtalar joint and not in the calcaneocuboid joint. The limitations of this study include the small number of cases and the short postoperative follow-up. Our results suggest that the flexibility of the talonavicular joint may be necessary when arthrodesis is performed on VAOA to contribute to the alignment correction. If it is not the case, TAR could be considered an alternative.

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.

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 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.

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.

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.

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.

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.

Physiologic Mechanical Stress Directly Induces Bone Formation by Activating Glucose Transporter 1 (Glut 1) in Osteoblasts, Inducing Signaling via NAD+-Dependent Deacetylase (Sirtuin 1) and Runt-Related Transcription Factor 2 (Runx2)

Mechanical stress is an important factor affecting bone tissue homeostasis. We focused on the interactions among mechanical stress, glucose uptake via glucose transporter 1 (Glut1), and the cellular energy sensor sirtuin 1 (SIRT1) in osteoblast energy metabolism, since it has been recognized that SIRT1, an NAD+-dependent deacetylase, may function as a master regulator of the mechanical stress response as well as of cellular energy metabolism (glucose metabolism). In addition, it has already been demonstrated that SIRT1 regulates the activity of the osteogenic transcription factor runt-related transcription factor 2 (Runx2). The effects of mechanical loading on cellular activities and the expressions of Glut1, SIRT1, and Runx2 were evaluated in osteoblasts and chondrocytes in a 3D cell-collagen sponge construct. Compressive mechanical loading increased osteoblast activity. Mechanical loading also significantly increased the expression of Glut1, significantly decreased the expression of SIRT1, and significantly increased the expression of Runx2 in osteoblasts in comparison with non-loaded osteoblasts. Incubation with a Glut1 inhibitor blocked mechanical stress-induced changes in SIRT1 and Runx2 in osteoblasts. In contrast with osteoblasts, the expressions of Glut1, SIRT1, and Runx2 in chondrocytes were not affected by loading. Our present study indicated that mechanical stress induced the upregulation of Glut1 following the downregulation of SIRT1 and the upregulation of Runx2 in osteoblasts but not in chondrocytes. Since SIRT1 is known to negatively regulate Runx2 activity, a mechanical stress-induced downregulation of SIRT1 may lead to the upregulation of Runx2, resulting in osteoblast differentiation. Incubation with a Glut1 inhibitor the blocked mechanical stress-induced downregulation of SIRT1 following the upregulation of Runx2, suggesting that Glut1 is necessary to mediate the responses of SIRT1 and Runx2 to mechanical loading in osteoblasts.

Increase in pancreatic enzymes following spinal alignment changes in the thoracolumbar junction: Potential for acute pancreatitis after kyphosis correction

BACKGROUND

Despite the identification of various risk factors for pancreatitis and hyperamylasemia following spinal surgery, no report has investigated the relationship between spinal alignment changes and elevated serum amylase levels. The purpose of this study was to investigate the relationship between spinal alignment changes and hyperamylasemia after spinal fusion.

METHODS

A total of 222 patients whose serum pancreatic amylase levels were measured before and after spinal surgery from December 2017 to May 2019 were included. Inclusion criteria were (1) spinal fusion including the thoracolumbar junction (T10-L2) and (2) serum pancreatic amylase measurements before, immediately after surgery (day 0), the day after surgery (day 1), and 1 week after surgery. Ultimately, 37 patients who met the criteria were analyzed. Patients with hyperamylasemia at day 0 and/or day 1 (H group) were then compared with those without hyperamylasemia (N group).

RESULTS

No significant differences in age, sex, surgical procedure, number of fused segments, intraoperative blood loss, operative time or American Society of Anesthesiologists physical status classification were observed between both groups. The H group had significantly larger preoperative thoracolumbar kyphosis (TLK) (H group: 22.6°, N group: 6.4°), postoperative TLK (H group: 16.8°, N group: 7.6°), and preoperative T12-L1 kyphosis angles (H group: 16.2°, N group: 7.9°) compared with the N group. Moreover, the H group demonstrated a significant decrease in TLK after surgery (H group: -5.8°, N group: 1.6°).

CONCLUSIONS

Risk factors for hyperamylasemia included a large preoperative TLK angle and a greater postoperative decrease in TLK. Thus, decreased TLK after spinal fusion surgery should prompt careful attention to abdominal symptoms and elevated pancreatic amylase levels.

Tranexamic Acid Reduces Total Blood Loss and the Amount of Stored Preoperative Autologous Blood Donation Needed for Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Fusion

Introduction

There are few published studies on posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) that have reported that the stored amounts of autologous blood donation (ABD) needed for the procedure were estimated by taking into account total blood loss (TBL). The aim of this study was to clarify the following clinical questions: (1) Does the use of tranexamic acid (TXA) reduce the TBL during PSF for AIS? (2) What volume of ABD should be stored to avoid allogeneic blood transfusions?

Methods

This study investigated 44 female patients who underwent PSF for AIS. A total of 33 patients underwent PSF without TXA (non-TXA group) and 11 patients underwent PSF with TXA (TXA group). TBL was determined by the hemoglobin (Hb) balance method calculated with circulating blood volume, Hb levels, hematocrit (Ht) levels before and three days after surgery, and the volumes of blood transfusions, including stored ABD. For the TXA patients, TBL was used to determine the appropriate amount of stored ABD and the number of ABD collections.

Results

The amount of TBL was lower in the TXA group compared to the non-TXA group. The mean required volume of stored ABD in the TXA group was 218.2 ± 577.3 mL, with a required maximum volume of 699.0 mL. The proportions of patients requiring allogeneic blood transfusion were as follows: 72.7% for those with no ABD collection, 45.5% for one ABD collection, and 0% for two ABD collections when TXA was used during surgery. 

Conclusions

TXA reduced the TBL of patients undergoing PSF for AIS. The maximum amount of stored ABD needed was 699.0 mL. Allogeneic blood transfusion can be avoided by storing two ABD collections when TXA is used during the surgery.

Mobile Application for Scoliosis Screening Using a Standard 2D Digital Camera

Several scoliosis detection systems, using three-dimensional (3D) cameras or sensors, have been developed in recent years. Because these systems require specific 3D digital cameras or sensors, and the equipment is expensive, they are rarely used in many countries and regions. The development of a scoliosis screening system that uses standard two-dimensional (2D) digital cameras that come with tablet personal computers (PCs) and smartphones will facilitate the efforts made to detect scoliosis patients on a global scale. The aim of this technical note was to report on a mobile application for scoliosis screening that uses a standard 2D digital camera. The subjects were patients aged 10 years or older who visited our outpatient clinic for scoliosis or suspected scoliosis and underwent whole-spine radiography. Photographs of subjects were obtained using a standard 2D digital camera connected to a tablet PC. For analysis, we used the simplified scoliosis diagnosis support application (Cobb First, Its Corporation, Kawasaki, Japan) which operates on Windows 10 operating system (OS). When an image was imported into the application, it was displayed within a grid. The grid consisted of four columns and 40 rows and was divided into 160 areas. Each image was converted into binarized image data by demarcating skin and background color. The image of the subject was displayed as a black subject on a white background. Two types of conditions were presented to process differences in the environment versus skin color. A binarized image with a clear outline was selected. The determination was displayed as a percentage of the black area in each grid. In each row of the grid, the left and right sides of the black area were compared, and the part with the larger area with respect to the opposite side was colored and displayed. Depending on the ratio of the difference, it was possible to display green, yellow, and red. If this mobile application is available for clinical use, it has the potential to improve the accuracy of screening by physicians and nurses. Furthermore, it may also be used globally to check for possible evidence of scoliosis at home to facilitate the early detection of patients who require a medical checkup for scoliosis. Although it is essential to perform a radiographic examination for the definitive diagnosis of scoliosis, our future goal is to limit radiation exposure and replace a radiologic method with one based on a tablet PC or smartphone. A mobile application using a standard 2D digital camera may improve the accuracy of screening scoliosis by physicians and may have global application in home environments.

MRI findings of spring ligament injury: association with surgical findings and flatfoot deformity

Background

Spring ligament injury is an important cause for flatfoot deformity; however, reliability of magnetic resonance imaging (MRI) findings of spring ligament injury is still ambiguous.

Purpose

To investigate the reliability of MRI findings for the diagnosis of spring ligament injury.

Material and methods

Forty-three cases with spring ligament injury proven by surgery and 29 control cases were enrolled. The spring ligament complex was demonstrated on proton density-weighted images reconstructed from 3D-isotropic MRI data. The presence of waviness, discontinuity, and abnormally high signal intensity of the spring ligament complex was evaluated by two radiologists in cooperation. Also, injury of the posterior tibial tendon (PTT) on MRI and the lateral talo-1st metatarsal angles on weight-bearing X-rays were evaluated.

Results

Discontinuity and abnormally high signal intensity of the superomedial calcaneonavicular ligament (SmCNL) on MRI were more frequently observed in patients with spring ligament injury than in controls (p < 0.001). Discontinuity and abnormally high signal intensity of the SmCNL were found more often in the PTT injury group than in those without (p < 0.001). The talo-1st metatarsal angle was greater in patients with discontinuity and abnormally high signal intensity of the SmCNL on MRI than in patients without these findings (p < 0.001).

Conclusion

Discontinuity and abnormally high signal intensity are reliable MRI findings for spring ligament injury and related disorders, such as flatfoot deformity and PTT injury.

Anatomical Study of the Cuboid and Its Ligamentous Attachments and Its Implications for a Cuboid Osteotomy

Background:

Lateral column lengthening (LCL) for flexible flatfoot is an effective surgery with powerful correction of deformity because it tightens only the lateral third of the long plantar ligament (LPL). However, LCL has been associated with joint damage at the osteotomy site and loss of foot flexibility owing to joint fixation. We focused on the cuboid and investigate a novel anatomical LCL osteotomy site that effectively tightens the LPL without damaging any joints.

Methods:

We studied 24 feet of 12 cadavers (mean age, 80.8 years). The lengths of the LPL and short plantar ligament, locations of the attachments, and shape and location of the cuneocuboid joint on the medial side of the cuboid were studied. ImageJ software was used to measure the osteotomy angle.

Results:

The lateral cuboid attachment of the LPL on average was located 4.6 mm from the calcaneocuboid joint, and the cuneocuboid joint on average was located 6.7 mm from the cuboid-metatarsal joint on the medial surface of the cuboid. The direct line connecting the anterior cuneocuboid joint and the oblique crest of the cuboid on average was at a 10.3-degree inclination posterior to the cuboid-metatarsal joint.

Conclusion:

A straight line must be selected between a point 4 mm from the calcaneocuboid joint laterally and 6 mm from the cuboid-metatarsal joint medially at a 10-degree posterior tilt to the cuboid-metatarsal joint to perform a cuboid osteotomy LCL without damaging the articular surface.

Clinical Relevance:

We investigated a potential novel cuboid osteotomy method for LCL.

Pulmonary Function Improves in Patients with Adolescent Idiopathic Scoliosis who Undergo Posterior Spinal Fusion Regardless of Thoracoplasty: A Mid-Term Follow-Up

Introduction

The purpose of the present study was to determine, in a mid-term follow-up 5 years or more after surgery, the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and expiratory flow in patients with adolescent idiopathic scoliosis (AIS) who underwent posterior spinal fusion (PSF) with or without thoracoplasty.

Methods

The subjects were 134 patients with AIS who underwent PSF between 2004 and 2013. Forty-five patients agreed to participate in the study. We divided the patients into two groups as follows: 24 patients who underwent PSF with thoracoplasty from 2004 to 2010 in the TP group and 21 patients who underwent PSF without thoracoplasty from 2011 to 2013 in the non-TP group. We evaluated whole spine X-ray imaging and pulmonary function tests (PFTs) in these patients. PFTs measured FVC, FEV1, peak expiratory flow (PEF), maximum expiratory flow at 50% FVC (V50), maximum expiratory flow at 25% FVC (V25), and the ratio of V50 to V25 (V50/V25).

Results

The main thoracic curves were 53.6 ± 10.1° before surgery, 19.8 ± 7.6° 1 week after surgery, 22.3 ± 8.3° 2 years after surgery, and 23.3 ± 7.6° at the most recent observation. Compared with preoperative values, FVC, FEV1, and % FEV1 were improved significantly at the most recent observation. No significant difference was observed between % FVC before surgery and at the most recent observation. Compared with preoperative values, PEF, V50, and V25 were improved significantly at the most recent observation. V50/V25 did not change significantly. The changes in PFT values in the TP group and the non-TP group were compared. No significant differences were observed in FVC, % FVC, FEV1, % FEV1, PEF, V50, or V25.

Conclusions

Regardless of whether thoracoplasty was performed or not, FVC, FEV1, and expiratory flow were improved 5 years or later after PSF.

Optimization of the Revised Tokuhashi Scoring System: New Prognostic Criteria for Metastatic Spinal Tumor in Surgical Cases

Introduction

The revised Tokuhashi scoring system has been used to predict survival in patients with metastatic spinal tumors. Because of the rapid progress of cancer therapy, the original criteria of the revised Tokuhashi scoring system became in recent years unsuitable. The study aim was to evaluate the validity of the revised Tokuhashi scoring system in patients who underwent spinal surgery and to establish new prognostic criteria.

Methods

The study enrolled 85 patients with metastatic spinal tumors who underwent spinal surgery. The patients' survival outcomes in October 2019 were as follows: 57 patients died; 10 were alive; and 18 had unknown prognoses. The study evaluated the validity of the Tokuhashi scoring system, and established and validated the new prognostic criteria.

Results

The accuracies of the Tokuhashi scoring system were 66.7% in the short-term group, 60% in the midterm group, and 100% in the long-term group. Among the patients who died, the survival period and total score were significantly correlated. Total score cutoff point was six points in the patients whose predicted survival was <6 months. Total score cutoff point was eight points in the patients whose predicted survival was ≥1 year.

Conclusions

As the prognosis of patients has improved in recent years, the original criteria of the revised Tokuhashi scoring system have been questioned as to their suitability to current treatments. Especially, the survival period among the patients with total scores of 7 and 8 points was not accurate. According to this study, the new prognostic criteria of the revised Tokuhashi scoring system were set to 0 to 6 points for the short-term group, 7 points for the midterm group, and 8 to 15 points for the long-term group.

Fixation of the osteochondral talar fragment yields good results regardless of lesion size or chronicity

PURPOSE

Osteochondral talar lesions, regardless of their size and/or chronicity, are, at our hospital, now treated by fixation of the fragment if the talar dome cartilage is judged to be healthy. The retrospective study described herein was conducted to assess clinical outcomes of this treatment strategy.

METHODS

The study group comprised 44 patients (18 men and 26 women) with 45 such talar lesions. In all cases, the osteochondral fragment was reduced and fixed with bone harvested from the osteotomy site and shaped into peg(s) (one to four pegs per lesion). Median follow-up was 2.1 years (1-9 years). The lesion area was measured on computed tomography arthrographs, and the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale was used to evaluate postoperative outcomes. Clinical failure was defined as a JSSF score < 80 points.

RESULTS

The mean JSSF score improved significantly from 63.5 points preoperatively to 93.0 postoperatively (p < 0.001). Treatment failure occurred in only one ankle (0.02%). The mean lesion area was 51.2 mm² (range 5-147 mm²). Correlation between lesion areas and the postoperative JSSF scores was weak (r = - 0.133). Correlation between the time of the trauma to the time of fixation surgery and the postoperative JSSF scores was also weak (r = 0.042). Radiographic outcomes were good for 28 ankles, fair for 10, and poor for 7.

CONCLUSION

Fixation of the lesion fragment, regardless of size and/or chronicity, appears to be appropriate in cases of an osteochondral talar lesion.

LEVEL OF EVIDENCE

IV.

MRI evaluation of dural sac enlargement by interspinous process spacers in patients with lumbar spinal stenosis: Does it play a role in the long term?

BACKGROUND

To investigate dural sac enlargements and spinal alignments in patients who underwent indirect decompression with interspinous spacers.

METHODS

The subjects were 20 patients who underwent indirect decompression using an interspinous spacer (X-STOP) without laminectomy. Of these 20 patients, 1 patient underwent implant removal surgery 1 month after X-STOP surgery and two patients dropped out. Ultimately, 17 patients were included in this study. MRI and X-ray images were investigated before surgery, 1 week after surgery, 3 months after surgery, and 2 years after surgery.

RESULTS

On MRI, the mean cross-sectional areas of the dural sac were 52.7 mm² before surgery, 73.2 mm² 1 week after surgery, 62.4 mm² 3 months after surgery, and 58.3 mm² 2 years after surgery. There was a significant 37% increase at 1 week postoperatively compared with that before surgery, but there were no significant differences between 3 months postoperatively and 2 years postoperatively. The disc angle in an extension posture was significantly decreased at 1 week after surgery compared with that before surgery, but there were no significant differences between before surgery, 3 months after surgery, and 2 years after surgery.

CONCLUSIONS

The interspinous process spacer increased the dural sac area by 37% 1 week after surgery, but the enlargement was not maintained at 3 months or 2 years after surgery. The use of interspinous process spacers produced an enlargement of the dural sac by limiting extension of the stenotic level only. However, its effect diminished 2 years after surgery.

Spinal Alignments of Residual Lumbar Curve Affect Disc Degeneration after Spinal Fusion in Patients with Adolescent Idiopathic Scoliosis: Follow-up after 5 or More Years

Introduction

Despite preserving lumbar disc mobility, spinal sagittal, and/or coronal alignment might ultimately impede surgical success. The purpose of this study was to elucidate the effects of spinal alignment on lumbar disc degeneration after 5 or more years in adolescent idiopathic scoliosis (AIS) patients who underwent spinal fusion.

Methods

Subjects were 49 AIS patients who underwent posterior spinal fusion without lumbar curve fusion. The inclusion criteria were the following: 1) Lenke type 1A, 1B, 2A or 2B, 2) age 10 to 19 years at the time of operation, and 3) minimum 5-year follow-up. The exclusion criteria were the following: 1) diagnosed as other than AIS, 2) history of lumbar disc herniation and spondylolysis, 3) subsequent surgery, and 4) history of surgery before AIS surgery. Nineteen patients agreed to participate in this research. X-rays, lumbar MRI, and questionnaires were evaluated. Disc degeneration in non-fused segments was defined as Pfirrmann grade 3 or higher. Patients with disc degenerations at the final observation (DD[+] group) were compared to those without disc degenerations (DD[−] group).

Results

There were no significant differences in the preoperative or postoperative 1-week X-ray parameters between both groups. The lumbar curve was significantly larger in the DD[+] group compared with the DD[−] group at the final observation (DD[+]: 16.8 degrees, DD[−]: 10.4 degrees, p = 0.035). The sagittal vertical axis (SVA) was significantly larger in the DD[+] group compared with the DD[−] group at the final observation (DD[+]: −4.4 mm, DD[−]: −34.3 mm, p = 0.006). SRS-22 function, self-image, and satisfaction scores were lower in the DD [+] group compared with the DD[−] group at the final observation.

Conclusions

The patients with DD had significantly larger lumbar curve and SVA with lower SRS-22 function, self-image, and satisfaction scores at the final observation. Even though the non-fused segments were preserved, spinal alignments of non-fused lumbar curve affect the DDs.

Hooks at the Upper Instrumented Vertebra Can Adjust Postoperative Shoulder Balance in Patients with Adolescent Idiopathic Scoliosis: 5 Years or More of Follow-up

Study Design

A retrospective cohort study.

Purpose

This study aims to investigate postoperative shoulder imbalance (PSI) ≥5 years postoperatively in patients who underwent posterior spinal fusion using hooks at the upper instrumented vertebra (UIV) for Lenke type 1 adolescent idiopathic scoliosis (AIS).

Overview of Literature

Studies have reported PSI due to excessive correction of the main thoracic curve.

Methods

We examined 56 patients with AIS who underwent a posterior spinal fusion with hooks at the UIV from 2004 to 2010. Of these, we enrolled 14 patients who underwent surgery, at least, 5 years ago. X-rays and Scoliosis Research Society-22 (SRS-22) questionnaire were administered. To evaluate the shoulder balance, T1 vertebral tilt angle (T1 tilt), clavicle angle, and radiographic shoulder height (RSH) were measured. PSI was considered as the absolute value of the postoperative RSH being ≥20 mm. Based on radiographs obtained immediately postoperatively, we divided patients into two groups as follows: the balanced group (absolute value of RSH <20 mm) and imbalanced group (absolute value of RSH ≥20 mm).

Results

The frequency of PSI was 28.6% immediately postoperatively, 0% 2 years postoperatively, and 7.1% at the last follow-up. In the balanced group, PSI did not occur even at 2 years postoperatively or at the last follow-up. In the imbalanced group, PSI was improved in all patients 2 years postoperatively and all patients, except one patient, at the last follow-up. No significant differences were noted in the frequency of distal adding-on at 2 years postoperatively or the last follow-up between the balanced group and the imbalanced group. We observed moderate negative correlations between the absolute value of T1 tilt and the SRS-22 pain and satisfaction at the last follow-up.

Conclusions

Hooks at the UIV could adjust the shoulder balance to avoid long-term PSI in patients with AIS.

A novel, self-assembled artificial cartilage-hydroxyapatite conjugate for combined articular cartilage and subchondral bone repair: histopathological analysis of cartilage tissue engineering in rat knee joints

Purpose

We previously created a self-assembled cartilage-like complex in vitro from only three cartilage components, hyaluronic acid (HA), aggrecan (AG) and type II collagen, without other materials such as cross-linking agents. Based on this self-organized AG/HA/collagen complex, we have created three novel types of biphasic cartilage and bone-like scaffolds combined with hydroxyapatite (HAP) for osteochondral tissue engineering. These scaffolds have been developed from self-assembled cartilage component molecules and HAP at the nanometer scale by manipulating the intermolecular relations.

Patients and methods

The surface structure of each self-organized biphasic cartilage and bone-like scaffold was evaluated by scanning electron microscopy, whereas the viscoelasticity was also analyzed in vitro. Three types of artificial cartilage–HAP conjugates were implanted into an osteochondral defect in rat knee joints, and bone and cartilage tissues of the implanted site were examined 4 and 8 weeks after implantation. The tissues were examined histopathologically to evaluate the effects of the implantation on the articular cartilage and subchondral bone tissues.

Results

Our in vitro and in vivo data reveal that the self-organized biphasic cartilage and bone-like scaffold conjugated with HAP are superior to the scaffold with no HAP in both cartilage regeneration and subchondral bone regeneration.

Conclusion

Our present study indicates that the self-organized biphasic cartilage and bone-like scaffold, which is conjugated with an HAP layer, may have potential not only to repair articular cartilage defects but also to ameliorate the degeneration of subchondral bone in the diseases with osteochondral defect.

Thoracic Deformity Correction and Changes of Vital Capacity, Forced Expiratory Volume in 1 Second, and Expiratory Flow in Adolescent Idiopathic Scoliosis Five Years or More after Posterior Spinal Fusion with Thoracoplasty

Introduction

The purpose of this study is to investigate thoracic deformity correction and pulmonary function changes in patients with adolescent idiopathic scoliosis (AIS) five years or more after undergoing posterior spinal fusion with thoracoplasty for correction of a thoracic deformity.

Methods

Subjects were 57 patients with AIS who underwent posterior spinal fusion between 2004 and 2010. 24 patients who had undergone thoracoplasty at least five years earlier agreed to participate in this research. X-rays, pulmonary function tests, and thoracic cage computed tomography (CT) were performed, and the Scoliosis Research Society Outcomes Questionnaire (SRS-22) was administered. CT axial images were used at the apex of the main thoracic (MT) curve. Apical vertebral rotation was evaluated using rotation angle to the sagittal plane (RA_sag). Thoracic deformities were evaluated using the rib hump index (RHi) and the posterior hemithoracic symmetry ratio (PHSr).

Results

There were no significant differences between the preoperative and the final observation forced vital capacity (FVC) or the preoperative and the final observation %FVC. The forced expiratory volume in 1 s (FEV1) and %FEV1 were significantly improved at the final observation: FEV1 (preoperative: 1.88 L, final observation: 2.05 L, p = 0.045) and %FEV1 (preoperative: 57.1%, final observation: 66.2%, p = 0.001). FEV1/FVC was also significantly improved at the final observation (preoperative: 83.0%, final observation: 86.4%, p = 0.019). The peak expiratory flow (PEF) was significantly improved at the final observation (preoperative: 3.67 L/s, final observation: 4.38 L/s, p = 0.029). On the CT assessment for thoracic deformities, there were no significant changes in RA_sag or RHi. PHSr was significantly increased at the final observation compared with the preoperative period.

Conclusions

With posterior spinal fusion in combination with thoracoplasty for AIS, although the correction of deformities was limited, the pulmonary function testing demonstrated the preservation of vital capacity (VC) and improvements in the forced expiratory volume in 1 s and expiratory flow.

SPACIA1/SAAL1 Deletion Results in a Moderate Delay in Collagen-Induced Arthritis Activity, along with mRNA Decay of Cyclin-dependent Kinase 6 Gene

This study was performed to elucidate the molecular function of the synoviocyte proliferation-associated in collagen-induced arthritis (CIA) 1/serum amyloid A-like 1 (SPACIA1/SAAL1) in mice CIA, an animal model of rheumatoid arthritis (RA), and human RA-synovial fibroblasts (RASFs). SPACIA1/SAAL1-deficient mice were generated and used to create mouse models of CIA in mild or severe disease conditions. Cell cycle-related genes, whose expression levels were affected by SPACIA1/SAAL1 small interfering RNA (siRNA), were screened. Transcriptional and post-transcriptional effects of SPACIA1/SAAL1 siRNA on cyclin-dependent kinase (cdk) 6 gene expression were investigated in human RASFs. SPACIA1/SAAL1-deficient mice showed later onset and slower progression of CIA than wild-type mice in severe disease conditions, but not in mild conditions. Expression levels of cdk6, but not cdk4, which are D-type cyclin partners, were downregulated by SPACIA1/SAAL1 siRNA at the post-transcriptional level. The exacerbation of CIA depends on SPACIA1/SAAL1 expression, although CIA also progresses slowly in the absence of SPACIA1/SAAL1. The CDK6, expression of which is up-regulated by the SPACIA1/SAAL1 expression, might be a critical factor in the exacerbation of CIA.

Modic changes and disc degeneration in adolescent idiopathic scoliosis patients who reach middle age without surgery: Can residual deformity cause lumbar spine degeneration?

BACKGROUND

We have yet to determine what types of lumbar degenerative changes can be observed on MRI in middle-aged adolescent idiopathic scoliosis (AIS) patients without undergoing surgery. The aims of this study were to investigate AIS patients who have reached middle age without undergoing surgery and to clarify if residual spinal deformities may have affected health-related quality of life (HRQOL) and lumbar spine degeneration.

METHODS

Subjects comprised AIS patients who reached middle age without surgery and who underwent whole-spine X-rays, lumbar MRI, and SRS-22 surveys. Of the 60 cases collected from five scoliosis centers, 25 patients who met the inclusion criteria were enrolled into the residual deformity (RD) group and analyzed. Controls (CTR) group comprised 25 individuals matched for age, sex, and BMI with the patient group.

RESULTS

MRI revealed no significant differences in the percentage of individuals with Pfirrmann grade 4 or 5 disc degeneration in 1 or more segments (RD group: 84%, CTR group: 60%, p = 0.059). Significantly more patients with Modic changes in 1 or more segments were observed in the RD group (RD group: 56%, CTR group: 8%, p < 0.001). All SRS-22 scores were significantly lower in the RD group. The lumbar curve cutoff point based on whether or not Modic change could be observed using ROC analysis was 39.5°.

CONCLUSIONS

Compared to healthy individuals, AIS patients with residual deformity who have never had surgery showed similar prevalence of disc degeneration, but they had more Modic changes and poor HRQOL. The cutoff point for lumbar curves of patients with and without Modic changes in middle age was 39.5°.

Lisfranc ligament anatomical reconstruction surgery is beneficial for chronic Lisfranc injuries

Category:

Midfoot/Forefoot

Introduction/Purpose:

Chronic Lisfranc fracture dislocation had been commonly treated with arthrodesis, but were these treatments suitable? The Lisfranc joint has sagittal motion with articular cartilage and functioning as a shock absorber. We reported the middle-term outcomes after performing Lisfranc ligament anatomical reconstruction surgery (LARS), using an optimal route of reconstruction based on anatomical measurements of and biomechanical experiments with cadavers. The purpose of this study is to determine the usefulness of LARS for chronic Lisfranc injuries to preserve the joint function.

Methods:

We underwent LARS for 8 cases of Chronic Lisfranc injuries (6 males, 2 females) from May 2012 to June 2017. Average age at surgery 26.1 years (18-38), average follow-up period is 28 months (2-46). The reconstruction route was via a burr hole created at a position 6 mm distal to the tarsometatarsal joint on the 2nd metatarsal, and at a depth of 10 mm. A burr hole was then created from the medial cuneiform bone to the 2nd metatarsal bone in a plantar and horizontal direction. The graft tendon was guided through the burr hole from the medial cuneiform bone to the 2nd metatarsal (double-layered side), was looped, and was guided back around the dorsum of the medial cuneiform(single layer) to reconstruct the dorsal ligament. We examined Myerson classification, Kaar evaluation and the postoperative clinical evaluation using Japanese Society for Surgery of Foot (JSSF) midfoot scale.

Results:

In Myerson classification, Type B2 6 cases and Type C1 2 cases. In Kaar evaluation, transverse instability (TI) 6 cases, longitudinal instability (LI) 2 cases. The average time from injury to surgery is 156 days on average (37-404). JSSF scores averaged 95 points (90-100). X - ray evaluations were almost good, but in 2 cases with weight bearing, a slight diastasis between the base of the first cuneiform and second metatarsal was observed. But there were no clinical symptoms such as pain. In the surgical procedure, scar is mediated in chronic cases. Therefore, we had to take time to obtain the reduction.

Conclusion:

Arthrodesis is gold standard for chronic Lisfranc joint injuries, but decline in foot flexibility is inevitable. LARS is beneficial for maintaining anatomical reduction, preserving the joint function, and shortening the post-therapy period. LARS gave stable results against Chronic Lisfranc joint injuries. LARS for chronic Lisfranc joint injuries is a useful procedure.

MRI Analysis for Clarification of Mechanism of Ankle Osteoarthritis

Category:

Ankle Arthritis

Introduction/Purpose:

We have previously studied the relationship between Takakura–Tanaka classification stages and bone-marrow edema (BME) in order to elucidate the pathology of ankle osteoarthritis (ankle OA) on magnetic resonance imaging (MRI). Moreover, we have investigated that BME onset on the talocrural joint can be predicted according to radiographic findings. In the present study, we focused on the changes around the subtalar joint to examine the relationship between talar lateral process impingement (TLPI) and foot and ankle joint alignment, and whether TLPI can be predicted on the basis of X-ray findings.

Methods:

We assessed 30 feet of 30 patients who had a diagnosis of ankle OA in our hospital and underwent MRI. Alignment was assessed radiographically by measuring the tibial anterior surface angle (TAS), the tibial lateral surface angle (TLS), the lateral talo-first metatarsal angle (LTMT), the lateral talocalcaneal angle (LTC), and the tibial axis–talar ratio (T-T ratio). MRI was obtained with the talocrural, subtalar and Chopart joints into 22 subdivided areas to examine the frequency of BME for each patient. TLPI was considered positive (+) when BME was found in the talar lateral process. The patients were divided into two groups according to TLPI positivity or negativity. Their BME frequency was examined, and significant differences in radiographically measured values were analysed with a t-test.

Results:

In the TLPI (+) group, BME development occurred at significantly higher frequencies in all areas except those surrounding the lateral process (p = 0.002). In addition, TLS was significantly lower (p = 0.02), and LTMT was significantly higher (p = 0.04). When the cut-off value on the ROC curve was set at TLS of =74° and LTMT of =19°, TLPI onset could be predicted with a sensitivity of 75% and a specificity of 71%.

Conclusion:

Our results revealed that in the TLPI (+) group, progression of the anteriorly opened talocrural joint and talar dorsiflexion may be causing the talar lateral process to hit the calcaneus. Furthermore, in the TLPI (+) group, BME in other areas also occurred at higher frequencies, and symptoms around the ankle joints may be occurring at multiple locations. The fact that TLPI could be predicted from radiography findings suggests that this may be a potential predictive tool of the severity of clinical symptoms.

Hiflex Foot Gear improves Quality of life in patients with osteoarthritis of the ankle

Category:

Ankle Arthritis

Introduction/Purpose:

There are few reports describing conservative therapy for ankle osteoarthritis. Hiflex Foot Gear (HFG) is a custom-made polyethylene ankle–foot orthosis developed to permit slight mobility of the ankle while providing adequate ankle support. The purpose of this study was to validate the hypothesis that HFG improves the quality of life (QOL) in patients with ankle osteoarthritis.Subjects and methods.

Methods:

Ten ankles from eight patients (one man, seven women) diagnosed with ankle osteoarthritis at this hospital, prescribed an HFG, and observed for follow-up for at least 3 months were included in this study. The patients’ mean age was 69.9 (range: 46?85) years. Patients were classified as Takakura–Tanaka stage IIIa (2 ankles), stage IIIb (2 ankles), stage IV (6 ankles), with a mean observation period of 8.9 (range: 3?13) months. Clinical evaluations were made before and 3 months after wearing the orthosis. The ankle/hindfoot scale of the Japanese Society for Surgery of the Foot (JSSF) Standard Rating System and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) subscale of the Japanese Orthopaedic Association/Japanese Society for Surgery of the Foot, respectively, were used for making evaluations. Scores were compared using a paired t-test.

Results:

JSSF scores improved from 55.1 points at baseline to 71.4 points after wearing the HFG (p < 0.001). According to the SAFE-Q subscales, changes after wearing the HFG were as follows: 28.9 to 61.9 points for items related to pain (p < 0.001), 36.9 to 53.7 points for those related to physical function and daily life (p = 0.001), 31.3 to 58.9 points for those related to social functions (p = 0.002), and from 31.3 to 65.0 points for those related to overall perception of health (p < 0.001); items related to shoes showed no substantial change (from 52.1 to 53.6 points).

Conclusion:

Our results revealed that wearing the HFG improved pain in patients with severe ankle osteoarthritis. Retained flexibility in the ankle range of motion was believed to be the factor underlying improvements in physical function and daily life, social functions, and overall perception of health. HFG is a potential option for conservative therapy in patients who cannot obtain sufficient pain control during the preoperative waiting period or in those who do not wish to undergo surgery.

Clinical results of capsular interposition arthroplasty for severe hallux rigidus

Category:

Midfoot/Forefoot

Introduction/Purpose:

There is no established surgical treatment for severe hallux rigidus (HR). Hamilton suggested capsular interposition arthroplasty (CIA), performed using an articular capsule and extensor hallucis brevis as a biologic spacer, as an alternative to metatarsophalangeal (MTP) joint fixation to treat severe HR. CIA is a preservation procedure that relieves pain and maintains joint function. We present the results of CIA performed at our facility to treat severe HR.

Methods:

In the present study, we further divided Hattrup’s grade II HR into two subtypes on the basis of joint space narrowing of 1stMTP. We recorded the severity of patients’ condition using our modified Hattrup’s classification. In this study, we did a follow-up of 8 cases in which CIA was performed to treat severe HR. The cases were followed up for 1 year or longer. The mean age of patients at surgery was 63.8 years, and the mean follow-up period was 7.1 years. Surgery was performed using a modified Hamilton method, which involves making an incision on the dorsal instead of the medial side and a manipulating the articular capsule in a different manner. Clinical outcomes were evaluated using the Japanese Society for Surgery of the Foot standard rating system (JSSF) scale. We investigated the pre- and post-operative ROM of the MTP joints and verified the presence or absence of complications.

Results:

It was observed that pain had reduced significantly in all cases after surgery. Following CIA, the mean ROM at extension was noted to have improved from 27.5° to 48.8° and the mean ROM at flexion had improved from 11.9° to 21.9°. The mean JSSF scale score has improved from 59.5 to 97.5 points. No complications were observed.

Conclusion:

This procedure is beneficial for pain relief and acquisition or maintenance of articular ROM and is a better choice for patients desiring preservation of ROM and articular function. It is imperative that patients follow proper rehabilitation for ROM and muscular strength preservation.

Spinal fusion on adolescent idiopathic scoliosis patients with the level of L4 or lower can increase lumbar disc degeneration with sagittal imbalance 35 years after surgery

Introduction

The purpose of this study was to investigate the long-term incidence of lumbar disc degeneration and Modic changes in the non-fused segments of patients with adolescent idiopathic scoliosis (AIS) who previously underwent spinal fusion.

Methods

Study subjects consisted of 252 patients with AIS who underwent spinal fusion between 1968 and 1988. Of 252 patients, 35 subjects underwent lumbar spine MRI and whole spine X-ray examination. The mean patient age at the time of follow-up was 49.8 years, with an average follow-up period of 35.1 years. We classified the subjects into two groups based on the lowest fused vertebra: H group whose lowest fused vertebra was L3 or higher levels and L group whose lowest fused vertebra was L4 or lower levels.

Results

The L group had significantly advanced disc degeneration on MRI. There was no significant difference between two groups in Modic changes. The L group showed less lumbar lordosis than the H group (H group: 48.1 degrees; and L group: 32.1 degrees) and greater SVA (H group: 1.2 cm; and L group: 5.5 cm).

Conclusions

In AIS patients, 35 years after spinal fusion surgery on average, we evaluated lumbar disc degeneration and Modic changes of the non-fused segments. In patients with the lowest fusion level at L4 or lower, there were reduced lumbar lordosis, considerable SVA imbalance, and severe disc degeneration compared with those with the lowest fusion level at L3 or higher. The lowest fusion level at L3 or higher is recommended to reduce disc degeneration in midlife.

MRI evaluation with severity of ankle osteoarthritis

Category:

Ankle Arthritis

Introduction/Purpose:

Takakura-Tanaka classification is effective as an X-ray evaluation method for determining the severity of and treatment strategy for ankle osteoarthritis (OA). Concerning OA, MRI is gaining attention as a tool for examining the condition of the articular cartilage over X-ray findings. However, there are few reports on the relationship between MRI and X- ray findings in ankle joints. We assessed MRI findings of ankle OA at each stage of Takakura-Tanaka classification to investigate the effects of bone and articular cartilage.

Methods:

We studied the localization of Bone Marrow Edema (BME) partitioned articular surface by MRI in 22 regions at the talocrural, talocalcaneal, talonavicular, and calcaneocuboid joints of 46 feet of 45 patients who had a diagnosis of ankle OA in our hospital. Furthermore, we compared the radiological findings with the localization of BME.

Results:

By MRI, the area where BME was seen is located in the anterior medial part of the talocrural joint. Pointedly, 60% of BME was confirmed on the tibial side of the talocrural joint. In addition, as the Takakura-Tanaka classification advanced, the identification of BME tended to increase on the anterior of the talus and the medial malleolus articular surface.

Conclusion:

We found on MRI that the localization of BME was identified by Takakura-Tanaka classification in osteoarthritis of the foot. On the other hand, there are some cases of OA without BME that were identified by X-ray in this study. In the future, there is a possibility that the severity of OA can be classified into more inclusive classifications by MRI. We intend to combine the severity of ankle OA with MRI findings and Takakura-Tanaka classification together.

Comparison of postoperative outcomes between modified Mann procedure and modified Lapidus procedure for hallux valgus

Category:

Bunion

Introduction/Purpose:

Surgery for hallux valgus (HV) includes a variety of techniques based on the osteotomy site. We use the modified Mann technique in cases with deformity ranging from 30° to 40° and the modified Lapidus procedure in HV cases with deformity of over 40° or with metatarsalgia.

Methods:

Here we report our investigation of the appropriateness of the modified Mann technique and the modified Lapidus procedure based on a comparison of postoperative outcomes. In total, 73 feet of 58 cases who underwent surgery for HV with subsequent follow-up observation for at least 1 year were included in the study. The modified Mann technique was performed on 31 feet of 26 cases (M Group), and the modified Lapidus procedure was performed on 42 feet of 32 cases (L Group). Six cases in the M Group and 39 cases in the L Group also underwent concurrent surgery for metatarsalgia. The outcome measures were changes in the HV angle, the angle between the M1M2, the Japanese Society for Surgery of the Foot (JSSF) hallux scale, complications, and HV recurrence. These outcome measures were compared using the unpaired t-test on standing anteroposterior X-ray of the feet.

Results:

In the M Group, comparison of pre- and postoperative radiological changes indicated that the HV angle improved from 38.2° to 11.4°, M1M2 angle improved from 14.5° to 5.0° respectively. JSSF hallux score improved from 53.3 to 89.6. Postoperative hallux varus was confirmed in four cases, Osteoarthrosis of the MTP joint in six, and HV recurrence in two. In the L Group, comparison of pre- and postoperative radiological changes indicated that the HV angle improved from 46.0° to 16.9°, M1M2 angle improved from 15.2° to 6.6°respectivelty. JSSF hallux score improved from 47.8 to 94.7. Postoperative hallux varus was confirmed in two cases, Osteoarthrosis of the MTP in four, and HV recurrence in four. In both groups, only preoperative HV angle exhibited significant differences (p < 0.0001).

Conclusion:

Surgical technique was selected based on HV severity and metatarsalgia whether were present; however, both groups showed satisfactory results. In cases of severe HV or in cases accompanied by metatarsalgia, we performed the modified Lapidus procedure that reduced pronation and valgus of first metatarsal. The X-ray and clinical findings of the present study showed that the results of the L Group were not inferior when compared to those of the M Group. Surgical technique should be selected based on both HV severity and lessor toe symptoms.

Safe Zone for the Plantar Portal

Category:

Arthroscopy

Introduction/Purpose:

Open surgery of the sole of the foot requires an extensive amount of soft tissue to be dissected. In recent years, various types of endoscopic surgery for the sole of the foot have been reported, making it possible to dynamically evaluate and treat plantar lesions with a small skin incision and minimal dissection. However, there have also been reports of complications involving plantar nerve injury. A good knowledge of the plantar nerve anatomy is crucial for safe endoscopic surgery of the sole. We aimed to anatomically dissect the soles of cadaveric feet to investigate the safe zones for plantar portals.

Methods:

We studied 36 feet of 24 cadavers. The soft tissue of the sole was dissected, and the relationships between the plantar nerve and flexor digitorum longus tendon, flexor hallucis longus tendon and peroneus longus tendon were studied. The plantar nerve course was digitally imaged and uploaded into Image J software to determine the nerve position. The back of the calcaneus, the medial side of the base of M (Metatarsal) 1, the medial side of the head of M1, the lateral side of the head of M5, and the proximal tip of M5 were plotted and defined as A, B, C, D, and E respectively on Image J. The nerve courses were plotted on AB, BE, and CD, and the percentage at which they were positioned on the line segment was calculated. Next, the bifurcation positions of each nerve were plotted and measured to the defined line segments.

Results:

No major differences were noted in the course of the medial plantar nerve and lateral plantar nerve. The medial plantar nerve and lateral plantar nerve ran between B and E, at 32.4% ± 4% and 61.2%± 5.1% respectively from B. No plantar arteries were found to run between the medial plantar nerve and lateral plantar nerve on BE. Taking mean and standard deviation values into account, no neurovascular structure existed from 36.4% to 56.1% along a line between the medial aspect of the base of M1 to the proximal tip of M5. The flexor digitorum longus tendon and peroneus longus tendon passed through the deep layer of this region.

Conclusion:

We believe this region to be a safe zone for creating plantar endoscopic portal. The plantar central portal can be created at the center of the sole. An approach from the plantar central portal to the flexor digitorum longus tendon, flexor hallucis longus tendon, and peroneus longus tendon with the plantar lateral portal, posteromedial portal, and toe portal allows for a greater range of vision and treatment options and may further advance endoscopic surgery of the sole.

Middle-term Clinical Evaluations of Lisfranc Ligament Anatomical Reconstruction Surgery

Category:

Midfoot/Forefoot

Introduction/Purpose:

We report the middle-term outcomes after performing Lisfranc ligament anatomical reconstruction surgery (LARS), using an optimal route of reconstruction based on anatomical measurements of and biomechanical experiments with cadavers.

Methods:

Subjects included 20 patients (8 female and 12 male, mean age: 35.5 years, mean follow-up period: 35 months) who were diagnosed with Lisfranc joint injury and underwent surgical treatment from 2012 to 2015. Acute case were fourteen cases, chronic cases were 6 cases. The optimal anatomical route of reconstruction was calculated from anatomical measurements obtained from 78 legs of cadavers. The Myerson’s classification and the Kaar’s classification based on stress X-rays were used to classify the injuries at the time of their occurrence. Furthermore, the Japanese Society for Surgery of the Foot (JSSF) Midfoot scale and Stein’s radiographic assessment were used for clinical evaluation postoperatively.

Results:

According to the Myerson’s classification, Type B1 was one case, Type B2 was 15 cases, Type C1 and Type C2 were each 2 cases. According to the Kaar’s classification, 17 patients had transverse-type injuries and 3 patients had longitudinal-type injury. Partial weight bearing was encouraged within 6 week and return to exercise within 12 weeks. Average JSSF scores at final follow-up were 93.8 points in both examples (85-100) respectively. Joint congruities on X ray were appropriate in most cases but admitted a little diastasis by one case of chronic and one acute case.

Conclusion:

LARS achieves both static and dynamic stability, does not require removal of the internal fixation material, and enables all patients to support a full load 8 weeks postoperatively. LARS is beneficial for maintaining anatomical reduction, preserving the joint, and shortening the post-therapy period. Our newly developed ligament reconstruction is not only able to acute injuries but also to the chronic injuries.

Long Term Changes in Muscles around the Knee Joint after ACL Resection in Rats: Comparisons of ACL-Resected, Contralateral and Normal Limb

The purpose of this study was to investigate the long-term effects of anterior cruciate ligament (ACL) resection on the morphological and contractile characteristics of rectus femoris (RF) and semimembranosus (SM) muscles in both injured and contralateral hindlimbs in rats. Wistar male rats (8-week old) were used. Rats were divided into two groups; ACL-resected and (sham-operated) control groups. Furthermore, right and left limbs of rats in the ACL-resected group were assigned as ACL-resected and contralateral groups, respectively, at 1 day, 1, 4, and 48 weeks after ACL resection. No ACL-resection-associated changes in the mass of both muscles were observed 1 week after ACL resection. On the other hand, ACL-resection-associated reduction on mean fiber cross-sectional area (fiber CSA) in RF muscle lasted 48 weeks after ACL resection. Furthermore, ACL-resection associated increase in fiber composition of type I fiber in RF muscle in contralateral limbs. In addition, long-term effects of ACL resection were observed in both ACL-resected and contralateral limbs. Evidences from this study suggested that ACL resection may cause to change in the morphological (fiber CSA) and contractile (distribution of fiber types) properties of skeletal muscles around the knee joint in not only injured but also contralateral limb. Rehabilitation for quantitative and qualitative muscle changes by ACL resection may be required a special care for a long-term period.

Relations of ankle alignment and MRI findings of ankle osteoarthritis

Category:

Ankle Arthritis

Introduction/Purpose:

MRI is gaining attention as a tool for examining the severity of osteoarthritis (OA) over X-ray findings. However, there are few reports on the relationship between MRI and X-ray findings in ankle joints. We assessed the combination of ankle joint alignment and MRI to find the factor to predict MRI findings from X-ray findings in OA.

Methods:

Of the 341 patients who had a diagnosis of ankle OA in our hospital from May 2009 to August 2015, we assessed 46 feet of 45 patients who underwent MRI. We determined ankle joint alignment by measuring tibial anterior surface (TAS) angle, and tibial lateral surface (TLS) angle on X-ray, and determined the areas of Bone Marrow Edema (BME) appearing on STIR, by partitioning 22 areas for talocrural, tarocalcaneal, Chopart joint. In the statistics analysis, we divided into two groups with and without BME, and we compared TAS angle and TLS angle. Moreover, for predicting the occurrence of BME, we divided the disease group into 2 groups, training set and validation set. We then verified the validity of the results by measuring cut-off value of TAS angle and TLS angle from ROC curve, an area which had statistically significant difference.

Results:

TAS angles or TLS angles were significantly lower in the group which showed BME at the anterior medial part of the tibia canopy and medial malleolus joint surface. From the ROC curve of the training set, the cut-off value (TAS angle of 82 degrees or less and TLS angle of 76 degrees or less) was obtained. Applying the obtained cut-off value to the validation set, it was possible to predict the occurrence of BME on the medial malleolus joint surface (sensitivity 71%, specificity 67%).

Conclusion:

Association with BME and clinical symptoms as well as disease prognosis has been reported in the OA area, so predicting the appearance of BME can be a useful index for prescribing a treatment plan. It was suggested that the appearance of BME could be predicted from X-ray findings because it was related to ankle alignment and MRI. It is possible that these findings could be used as a new diagnostic tool to estimate disease severity in the future.

Midlife changes of health-related quality of life in adolescent idiopathic scoliosis patients who underwent spinal fusion during adolescence

PURPOSE

Our previous study reported a good health-related quality of life (HRQOL) in adolescent idiopathic scoliosis (AIS) patients 21 years or more after surgery. The purpose of this study is to investigate midlife changes in HRQOL among AIS patients who passed further 5 years from the previous survey.

METHODS

Subjects were 252 individuals who underwent spinal fusion for AIS between 1968 and 1988. The survey was administered twice-in 2009 and in 2014 using Scoliosis Research Society Patient Questionnaire (SRS-22). We analysed survey responses from 42 individuals (39 females, 3 males) who responded to both surveys.

RESULTS

The average scores for each respective domain of the SRS-22 in 2009 and 2014, respectively, were: function, 4.3 and 4.2; pain, 4.3 and 4.3; self-image, 3.0 and 2.9; mental, 3.9 and 3.8; satisfaction, 3.6 and 3.5. There were no significant differences in any domain of the SRS-22 between 2009 and 2014. Comparing non-fused segments of the lumbar spine of patients with fewer than four discs remaining with patients with four discs or more remaining, SRS-22 satisfaction score decreased more in patients with fewer than four discs (change in patients with four discs or more: -0.02; change in patients with fewer than four discs: -0.38; P = 0.05).

CONCLUSION

Each SRS-22 subscore was similar between 2009 and 2014 surveys. Those scoliosis patients who underwent spinal fusion during adolescence had good HRQOL scores in midlife. Even after five years passed, good conditions were maintained.