Risk Factors for Residual Back Pain After Balloon Kyphoplasty for Osteoporotic Vertebral Fracture.

Background: Balloon kyphoplasty (BKP) is a method for the management of osteoporotic vertebral body fracture (OVF). However, improvement in back pain (BP) is poor in some patients, also previous reports have not elucidated the exact incidence and risk factors for residual BP after BKP. We clarified the characteristics of residual BP after BKP in patients with OVF. Hypothesis: In this study, we hypothesize that some risk factors may exist for residual BP 2 years after the treatment of OVF with BKP. Patients and Methods: A multicenter cohort study was performed where patients who received BKP within 2 months of OVF injury were followed-up for 2 years. BP at 6 months after surgery and final observation was evaluated by Visual Analog Scale (VAS) score. Patients with a score of 40 mm or more were allocated to the residual BP group, and comparisons between the residual back pain group and the improved group were made for bone density, kyphosis, mobility of the fractured vertebral body, total spinal column alignment, and fracture type (fracture of the posterior element, pedicle fracture, presence or absence of posterior wall damage, etc.). Also, Short Form 36 (SF-36) for physical component summary (PCS) and mental component summary (MCS) at the final follow-up was evaluated in each radiological finding. Results: Of 116 cases, 79 (68%) were followed-up for 2 years. Two years after the BKP, 26 patients (33%) experienced residual BP. Neither age nor sex differed between the groups. In addition, there was no difference in bone mineral density, BKP intervention period (period from onset to BKP), and osteoporosis drug use. However, the preoperative height ratio of the vertebral body was significantly worse in the residual BP group (39.8% vs. 52.1%; p = 0.007). Two years after the operation, the vertebral body wedge angle was significantly greater in the residual BP group (15.7° vs. 11.9°; p = 0.042). In the multiple logistic regression model with a preoperative vertebral body height ratio of 50% or less [calculated by receiver operating characteristic (ROC) curve], the adjusted odds ratio for residual BP was 6.58 (95% confidence interval 1.64-26.30; p = 0.007); similarly, patients with vertebral body height ratio less than 50% had a lower score of SF-36 PCS 24.6 vs. 32.2 p = 0.08. Conclusion: The incidence of residual BP 2 years after BKP was 33% in the current study. The risk factor for residual BP after BKP was a preoperative vertebral body height ratio of 50% or less, which should be attentively assessed for the selection of a proper treatment scheme and to provide adequate stabilization. Level of Evidence: III.

Machine-learning-based approach for nonunion prediction following osteoporotic vertebral fractures.

PURPOSE: An osteoporotic vertebral fracture (OVF) is a common disease that causes disabilities in elderly patients. In particular, patients with nonunion following an OVF often experience severe back pain and require surgical intervention. However, nonunion diagnosis generally takes more than six months. Although several studies have advocated the use of magnetic resonance imaging (MRI) observations as predictive factors, they exhibit insufficient accuracy. The purpose of this study was to create a predictive model for OVF nonunion using machine learning (ML). METHODS: We used datasets from two prospective cohort studies for OVF nonunion prediction based on conservative treatment. Among 573 patients with acute OVFs exceeding 65 years in age enrolled in this study, 505 were analyzed. The demographic data, fracture type, and MRI observations of both studies were analyzed using ML. The ML architecture utilized in this study included a logistic regression model, decision tree, extreme gradient boosting (XGBoost), and random forest (RF). The datasets were processed using Python. RESULTS: The two ML algorithms, XGBoost and RF, exhibited higher area under the receiver operating characteristic curves (AUCs) than the logistic regression and decision tree models (AUC = 0.860 and 0.845 for RF and XGBoost, respectively). The present study found that MRI findings, anterior height ratio, kyphotic angle, BMI, VAS, age, posterior wall injury, fracture level, and smoking habit ranked as important features in the ML algorithms. CONCLUSION: ML-based algorithms might be more effective than conventional methods for nonunion prediction following OVFs.

Risk factors of the poor long-term prognosis of osteoporotic vertebral fractures: A multicenter cohort study.

INTRODUCTION: The presence of existing osteoporotic vertebral fracture (OVF) increases the mortality risk. However, the influence of the characteristics of OVF is unclear. This study aimed to investigate the influence of new OVF on patients' long-term prognosis using our past cohort study. METHOD: This is an extension study of our cohort study carried out between 2005 and 2007. In the present extension study, of 420 patients, 197 whose contact information was available at the 6-month follow-up were included in the telephone survey in 2018. Five patients refused to participate in the survey, and 82 could not be contacted. Eventually, 110 patients were enrolled. Of the Demographic data, radiological findings, medical history, and clinical outcome were investigated at injury onset and at the 6-month follow-up. A proportional hazard model was used to investigate the risk factors for mortality. RESULTS: Among 110 patients, 33 died. Male sex and low body mass index (BMI <18.5 kg/m2) were significant risk factors for mortality [hazard ratio (HR) = 6.40, 1.01-40.50; 5.24, 1.44-19.04, respectively]. The history of stroke and liver disease increased the risk of mortality (HR = 13.37, 1.93-92.7; 6.62, 1.15-38.14, respectively). As regards radiological findings, local kyphosis progression per 1° or ≥7° were significant risk factors of mortality (HR = 1.20, 1.06-1.36; 5.38, 1.81-16.03, respectively). CONCLUSIONS: A telephone survey at 12 years after the occurrence of OVF analyzed risk factors for mortality and showed that a progression of local kyphosis in fractures between injury onset and 6 months after injury was a risk factor of poor prognosis.

Characteristic radiological findings for revision surgery after balloon kyphoplasty.

Balloon kyphoplasty (BKP) sometimes fails to improve patients' outcomes, with revision surgery, using anterior or posterior reconstruction, being required. The purpose of this study was to investigate the radiological risk factors of failure after BKP in the treatment of osteoporotic vertebral fractures (OVFs). This case-control study included 105 patients treated with single BKP and 14 patients  who required revision BKP. We evaluated radiological findings differentiating both groups, using plain radiography and computed tomography, before BKP. Angular flexion-extension motion was significantly greater in the revision than BKP group. While the frequency of pedicle fracture and posterior wall injury was not different between the groups, a split type fracture was more frequent in the revision group. Split type fracture had the highest adjusted odds ratio (OR) for revision (16.5, p = 0.018). Angular motion ≥14° increased the risk for revision surgery by 6-fold (p = 0.013), with endplate deficit having an OR of revision of 5.0 (p = 0.032). The revision rate after BKP was 3.8%, with split type fracture, greater angular motion and large endplate deficit being risk factors for revision. Treatment strategies for patients with these risk factors should be carefully evaluated, considering the inherent difficulties in performing revision surgery after BKP.

Development of a scoring system for predicting adjacent vertebral fracture after balloon kyphoplasty.

BACKGROUND CONTEXT: The incidence of adjacent vertebral fracture (AVFs) is reported to be 10%-38% after balloon kyphoplasty. However, no reports have established a system for prediction of AVF occurrence. PURPOSE: To establish a scoring system for predicting AVF occurrence after balloon kyphoplasty for osteoporotic vertebral fractures (OVFs). DESIGN: A prospective cohort study. PATIENT SAMPLE: Consecutive elderly patients aged 65 years and older who underwent balloon kyphoplasty for OVFs within 2 months after the onset. OUTCOME MEASURES: AVF was confirmed by X-ray. METHODS: From 2015 to 2017, 116 consecutive patients from 10 participating hospitals who underwent balloon kyphoplasty were enrolled in this study. Prior to study enrollment, each patient underwent plain X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) of the thoracic and lumbar spine. Severity of pain was subjectively assessed using a visual analog scale (VAS) based on the average level of back pain that the patient had experienced in the preceding week. After enrollment, subjects underwent balloon kyphoplasty. Quality of life was evaluated using SF-36. Patients were followed up for at least 6 months. RESULTS: Of the 116 patients enrolled, 109 patients with all the required data at the time of enrolment and the 6-month follow-up were included in the study. A total of 32 patients (29%) showed AVFs within the 6-month follow-up. No significant differences were observed in each clinical outcome at 6-month follow-up, although higher VAS score for back pain at 1-month follow-up was observed in the AVF group (37.5) than in the non-AVF group (20.8, p<.001). Wedge angle of vertebrae before surgery was greater in the AVF group (21.6°) than in the non-AVF group (15.7°, p<.001). The change in wedge angle between pre- and postsurgery was greater in the AVF group than in the non-AVF group, whereas the change in local kyphosis was not significantly different. The multiple logistic regression model showed increased odds ratio (OR) of thoracic or thoracolumbar spine, old OVF presence, >25° kyphosis before surgery, and >10°correction for AVF. Based on this result, a simple scoring system for predicting AVF occurrence was developed. The total AVF score was calculated as the sum of the individual scores, which varied from 0 to 6. All patients with 5-6 points sustained AVF. CONCLUSIONS: More severe wedge angle before surgery, correction degree, old OVF presence, and thoracolumbar level were predictive factors for AVF. All patients with AVF risk score of 5 or more showed AVF. This information may aid preoperative risk assessment, informed shared decision-making, and consideration of potential alternative management strategies.

ISSLS PRIZE IN CLINICAL SCIENCE 2019: clinical importance of trunk muscle mass for low back pain, spinal balance, and quality of life-a multicenter cross-sectional study.

STUDY DESIGN: A multicenter cross-sectional study. OBJECTIVES: To clarify the relationship of trunk muscle mass with low back pain, spinal sagittal balance, and quality of life. Few reports have investigated the relationship of trunk muscle mass with lumbar spine function and spinal balance, and the clinical significance of trunk muscle mass remains unclear. METHODS: Patients attending spinal outpatient clinics at 10 different medical institutions were enrolled in this study. Patient demographics, trunk muscle mass and appendicular skeletal muscle mass (ASM) measured by bioelectrical impedance analysis (BIA), body mass index (BMI), Charlson Comorbidity Index (CCI), the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated. Multivariate nonlinear regression analysis was used to investigate the association of trunk muscle mass with the ODI, VAS score, SVA, and EQ5D score. RESULTS: Of 2551 eligible patients, 1738 (mean age 70.2 ± 11.0 years; 781 men and 957 women) were enrolled. Trunk muscle mass was significantly correlated with the ODI, VAS score, SVA, and EQ5D score (P < 0.001) when adjusted for age, sex, BMI, ASM, CCI, and history of lumbar surgery. Patient deterioration was associated with a decrease in trunk muscle mass, and the deterioration accelerated from approximately 23 kg. CONCLUSIONS: Trunk muscle mass was significantly associated with the ODI, VAS score, SVA, and EQ5D score. Trunk muscle mass may assume an important role to elucidate and treat lumbar spinal dysfunction and spinal imbalance. These slides can be retrieved under Electronic Supplementary Material.

Balloon Kyphoplasty Versus Conservative Treatment for Acute Osteoporotic Vertebral Fractures With Poor Prognostic Factors: Propensity Score Matched Analysis Using Data From Two Prospective Multicenter Studies.

STUDY DESIGN: A multicenter, prospective, single-arm, intervention study. OBJECTIVE: The aim of this study was to investigate efficacy of balloon kyphoplasty (BKP) for acute osteoporotic vertebral fractures (OVFs) in patients with poor prognostic factors. SUMMARY OF BACKGROUND DATA: The indications for BKP remain unclear. Characteristic magnetic resonance imaging (MRI) findings (high-intensity or diffuse low-intensity area in fractured vertebrae on T2-weighted images) were reportedly predictive of delayed union. METHODS: This study enrolled 106 patients with poor prognostic MRI findings who underwent BKP within 2 months after injury, and 116 controls with acute OVFs and the same poor prognostic factors who underwent conservative treatment. Patients were propensity score matched in a logistic regression model adjusted for age, sex, number of baseline old fractures, and fracture level. The primary outcome was reduction in activities of daily living (ADLs) at 6 months after fracture, and the secondary outcomes were improvement in short-form (SF)-36 subscales, back pain visual analog scale (VAS) score, and vertebral body deformity. RESULTS: A decrease in ADLs occurred in 5.6% of patients in the BKP group and 25.6% of patients in the conservative treatment group (P < 0.001). The SF-36 vitality subscale score improved by 26.9 ±â€Š25.9 points in the BKP group and 14.5 ±â€Š29.4 points in the control group (P = 0.03). The VAS pain score improved by 43.4 ±â€Š34.4 in the BKP group and 52.2 ±â€Š29.8 in the control group (P = 0.44). The vertebral body wedge angle improved by 5.5 ±â€Š6.2° in the BKP group and -6.3 ±â€Š5.0° in the control group (P < 0.0001). The percent vertebral body height improved by 15.2 ±â€Š19.2% in the BKP group and -20.6 ±â€Š14.2% in the control group (P < 0.0001). CONCLUSION: ADLs, quality of life, and vertebral deformity showed greater improvement with BKP intervention for acute OVF with poor prognostic factors than with conservative treatment at 6 months after injury. Our treatment strategy uses BKP intervention according to the presence or absence of poor prognostic MRI findings. LEVEL OF EVIDENCE: 4.

Differences in short-term clinical and radiological outcomes depending on timing of balloon kyphoplasty for painful osteoporotic vertebral fracture.

BACKGROUND: Balloon kyphoplasty or vertebroplasty is widely performed as a surgical intervention for osteoporotic vertebral fracture (OVF) and the effects have been investigated in many previous studies. However, the influence of the timing of the procedure on patient outcomes has not been studied formally. The purpose of this study was to investigate differences in the surgical outcomes of OVFs according to the timing of balloon kyphoplasty. METHODS: This was a multicenter cohort study. Participants comprised 72 consecutive patients who underwent balloon kyphoplasty between January 2012 and January 2016. Patients were analyzed in two groups according to the timing of kyphoplasty after onset (Early group: ≤2 months; Late group: >2 months). Follow-up continued for more than 6 months. RESULTS: A total of 72 patients were effectively analyzed. Of these, 27 (38%) patients underwent kyphoplasty within 2 months after symptom onset. The Late group showed greater angular motion of fractured vertebrae (p = 0.005) and compression of anterior vertebral height (p = 0.001) before surgery. Final outcomes adjusted for age and preoperative outcome showed lower visual analog scale (VAS) scores for low back pain in the Early group than in the Late group (19.9 vs. 30.4, p = 0.049). Final relative anterior vertebral height and kyphotic angle were more preserved in the Early group than in the Late group (p = 0.002 and p = 0.020, respectively), although absolute differences were not significant. CONCLUSIONS: Vertebral height and kyphotic angle before and after balloon kyphoplasty were greater in patients who underwent kyphoplasty within 2 months after onset, and the VAS score for low back pain at final follow-up was better. Our results support kyphoplasty within 2 months.

Waterless Hand Rub Versus Traditional Hand Scrub Methods for Preventing the Surgical Site Infection in Orthopedic Surgery.

MINI: Fourteen hundred consecutive patients were investigated for evaluating the utility of waterless hand rub before orthopaedic surgery. The risk in the surgical site infection incidence was the same, but costs of liquids used for hand hygiene were cheaper and the hand hygiene time was shorter for waterless protocol, compared with traditional hand scrub. STUDY DESIGN: A retrospective cohort study with prospectively collected data. OBJECTIVE: The aim of this study was to compare SSI incidences, the cost of hand hygiene agents, and hand hygiene time between the traditional hand scrub and the waterless hand rub protocols before orthopedic surgery. SUMMARY OF BACKGROUND DATA: Surgical site infections (SSI) prolong hospitalization and are a leading nosocomial cause of morbidity and a source of excess cost. Recently, a waterless hand rub protocol comprising alcohol based chlorhexidine gluconate for use before surgery was developed, but no studies have yet examined its utility in orthopedic surgery. METHODS: Fourteen hundred consecutive patients who underwent orthopedic surgery (spine, joint replacement, hand, and trauma surgeries) in our hospital since April 1, 2012 were included. A total of 712 cases underwent following traditional hand scrub between April 1, 2012 and April 30, 2013 and 688 cases underwent following waterless hand rub between June 1, 2013 and April 30, 2014. We compared SSI incidences within all and each subcategory between two hand hygiene protocols. All patients were screened for SSI within 1 year after surgery. We compared the cost of hand hygiene agents and hand hygiene time between two groups. RESULTS: The SSI incidences were 1.3% (9 of 712) following the traditional protocol (2 deep and 7 superficial infections) and 1.1% (8 of 688) following the waterless protocol (all superficial infections). There were no significant differences between the two groups. The costs of liquids used for one hand hygiene were about $2 for traditional hand scrub and less than $1 for waterless hand rub. The mean hand hygiene time was 264 seconds with the traditional protocol and 160 seconds with the waterless protocol. CONCLUSION: Waterless hand rub with an alcohol based chlorhexidine gluconate solution can be a safe, quick, and cost-effective alternative to traditional hand scrub. LEVEL OF EVIDENCE: 3.

Intradural chondroma in the cervical spine: case report.

Chondromas are benign tumors that are rarely located in the spine. The authors present a rare occurrence of a spinal chondroma that developed as an intradural but extramedullary tumor in a 60-year-old woman. The location of the tumor at C4-5 was confirmed by MRI, with hyperintensity on T2-weighted images and isointensity on T1-weighted images. The tumor was completely contained intradurally, with no continuity to any vertebrae. It adhered to the anterior dura, indicative of its likely origin from the dura mater. The tumor was completely resected, with no sign of recurrence after 3 years postoperatively. Although reports of chondromas originating from the dura mater have been previously described, these have all been intracranial tumors. To the best of the authors' knowledge, this is the first report of an intradural chondroma located in the spine. Therefore, chondromas should be considered in the differential diagnosis of intradural spinal tumors.

Discriminating imaging findings of acute osteoporotic vertebral fracture: a prospective multicenter cohort study.

BACKGROUND: Appropriate treatment of osteoporotic vertebral fractures (OVF) requires knowledge of the age of the fracture. Although diagnostic imaging has made remarkable progress in recent years, it remains difficult to differentiate acute fractures from old. Our purpose was to investigate chronological changes in radiological findings after OVF and to identify discriminators of acute versus older injuries. METHODS: We evaluated 139 vertebrae in 136 patients. All patients underwent X-ray and magnetic resonance imaging (MRI) examination within 2 weeks of injury and again after 6 months. The anterior vertebral height ratio (AVHR) was calculated on lateral X-ray, and the intensity change of the posterior wall of the fractured vertebra was evaluated on T1-weighted MRI. The cutoff AVHR value to diagnose acute fracture was determined by receiver operating characteristic (ROC) curve analysis. RESULTS: Average AVHR fell from 84.6% at initial visit to 63.7% at 6 months. When acute fracture was defined as AVHR >75%, sensitivity was 85.6%, specificity was 67.6%, and positive predictive value was 72.6%. On MRI, 83.5% of fractured vertebrae showed intensity change in the posterior wall in the acute stage, which fell to 41.7% of vertebrae after 6 months. When intensity change in the posterior wall and AVHR >75% were both present, the specificity and positive predictive value for diagnosing acute fracture improved to 87.1% and 84.7%, respectively. CONCLUSIONS: This study suggests that vertebral fracture rarely shows significant collapse on X-ray in the first 2 weeks after injury. The combination of intensity change in the posterior wall on MRI and AVHR >75% on X-ray indicates a high probability of acute fracture.

Prognostic factors for reduction of activities of daily living following osteoporotic vertebral fractures.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To elucidate the prognostic factors indicating reduced activities of daily living (ADL) at the time of the 6-month follow-up after osteoporotic vertebral fracture (OVF). SUMMARY OF BACKGROUND DATA: OVF has severe effects on ADL and quality of life (QOL) in elderly patients and leads to long-term deteriorations in physical condition. Many patients recover ADL with acceleration of bony union and spinal stability, but some experience impaired ADL even months after fracture. Identifying factors predicting reduced ADL after OVF may prove valuable. METHODS: Subjects in this prospective study comprised 310 OVF patients from 25 institutes. All patients were treated conservatively without surgery. Pain, ADL, QOL, and other factors were evaluated on enrollment and at 6 months. ADL were evaluated using the criteria of the Japanese long-term care insurance system to evaluate the degree of independence. We defined reduced ADL as a reduction of at least single grade at 6 months after fracture and investigated factors predicting reduced ADL after OVF, using uni- and multivariate regression analysis. RESULTS: ADL were reduced at 6 months after OVF in 66 of 310 patients (21.3%). In univariate analysis, age more than 75 years (P = 0.044), female sex (P = 0.041), 2 or more previous spine fractures (P = 0.009), presence of middle column injury (P = 0.021), and lack of regular exercise before fracture (P = 0.001) were significantly associated with reduced ADL. In multivariate analysis, presence of middle column injury (odds ratio [OR], 2.26; P = 0.022) and lack of regular exercise before fracture (OR, 2.49; P = 0.030) were significantly associated with reduced ADL. CONCLUSION: These results identified presence of middle column injury of the vertebral body and lack of regular exercise before fracture as prognostic factors for reduced ADL. With clarification and validation, these risk factors may provide crucial tools for determining subsequent OVF treatments. Patients showing these prognostic factors should be observed carefully and treated with more intensive treatment options.

Risk factor analysis for motor deficit and delayed recovery associated with L4/5 lumbar disc herniation.

STUDY DESIGN: Retrospective study of multivariable analysis for the risk factors of motor deficit associated with lumbar disc herniation (LDH). OBJECTIVES: To identify the risk factors for motor deficit and delayed recovery after surgery in patients with LDH. SUMMARY OF BACKGROUND DATA: LDH can cause motor deficit as well as pain and sensory disturbance. Even though motor deficit can lead to disabilities and affect treatment plans, few studies have described motor deficit and its risk factors in LDH patients. METHODS: Seventy-six consecutive patients who underwent microsurgical or microendoscopic discectomy for LDH at the L4/5 level were retrospectively reviewed. Motor deficit was defined as tibialis anterior muscle strength of lower than grade 4 by the manual muscle test, and delayed recovery was defined as cases requiring longer than 3 months to achieve complete recovery. The possible risk factors including sex, age, symptom duration, preoperative radiographic parameters, and type of herniation were evaluated by multivariate logistic regression analysis. RESULTS: Forty-three patients (56.6%) suffered from motor deficit before surgery. Forty cases (93%) completely recovered within a mean duration of 4 months. Multivariate logistic regression analysis revealed that noncontained-type (P=0.012, odds ratio=13.7) and migrated herniated nucleus pulposus (P=0.033, odds ratio=9.8) were important risk factors for motor deficit. Furthermore, severe motor deficit (preoperative manual muscle test≤3; P=0.019, odds ratio=19.6) and noncontained type (P=0.049, odds ratio=5.17) were identified as important risk factors for delayed recovery. CONCLUSIONS: Noncontained-type or migrated herniated nucleus pulposus seem to be the most important risk factors for motor deficit in LDH, whereas severe motor deficit and noncontained type seem to be associated with delayed recovery. The treatment options for patients with these factors at first visit should be carefully chosen during the follow-up period.

The influence of approach side on facet preservation in microscopic bilateral decompression via a unilateral approach for degenerative lumbar scoliosis. Clinical article.

OBJECT: The authors compared the clinical outcomes of microscopic bilateral decompression via a unilateral approach (MBDU) for the treatment of degenerative lumbar scoliosis (DLS) and for lumbar canal stenosis (LCS) without instability. The authors also compared postoperative spinal instability in terms of different approach sides (concave or convex) following the procedure. METHODS: The authors retrospectively reviewed data obtained in 50 consecutive patients (25 in the DLS group and 25 in the LCS group) who underwent MBDU; the minimum follow-up period was 2 years. Patients with DLS were divided into 2 subgroups according to the surgical approach side: a concave group (23 segment) and a convex group (17 segments). The Japanese Orthopaedic Association Scale scores for the assessment of low-back pain were evaluated before surgery and at final follow-up. The Japanese Orthopaedic Association Scale scores and recovery rates were compared between the DLS and LCS groups, and between the convex and concave groups. Cobb angle and scoliotic wedging angle (SWA) were evaluated on standing radiographs before surgery and at final follow-up. Facet joint preservation (the percentage of preservation) was assessed on pre- and postoperative CT scans, compared between the LCS and DLS groups, and compared between the concave and convex groups. The influence of approach side on postoperative progression of segmental instability was also examined in the DLS group. RESULTS: The mean recovery rate was 58.7% in the DLS and 62.0% in the LCS group. The mean recovery rate was 58.6% in the convex group and 60.6% in the concave group. There were no significant differences in recovery rates between the LCS and DLS groups, or between the DLS subgroups. The mean Cobb angles in the DLS group were significantly increased from 12.7° preoperatively to 14.1° postoperatively (p < 0.05), and mean preoperative SWAs increased significantly from 6.2° at L3-4 and 4.1° at L4-5 preoperatively to 7.4° and 4.9°, respectively, at final follow-up (p < 0.05). There was no significant difference in percentage of preservation between the DLS and LCS groups. The mean percentages of preservation on the approach side in the DLS group at L3-4 and L4-5 were 89.0% and 83.1% in the convex group, and those in the concave group were 67.3% and 77.6%, respectively. The percentage of preservation at L3-4 was significantly higher in the convex than the concave group. The mean SWA had increased in the concave group (p = 0.01) but not the convex group (p = 0.15) at final follow-up. CONCLUSIONS: The MBDU can reduce postoperative segmental spinal instability and achieve good postoperative clinical outcomes in patients with DLS. The convex approach provides surgeons with good visibility and improves preservation of facet joints.

Factors affecting neurological deficits and intractable back pain in patients with insufficient bone union following osteoporotic vertebral fracture.

The purpose of this study was to examine factors affecting the severity of neurological deficits and intractable back pain in patients with insufficient bone union following osteoporotic vertebral fracture (OVF). Reports of insufficient union following OVF have recently increased. Patients with this lesion have various degrees of neurological deficits and back pain. However, the factors contributing to the severity of these are still unknown. A total of 45 patients with insufficient union following OVF were included in this study. Insufficient union was diagnosed based on the findings of vertebral cleft on plain radiography or CT, as well as fluid collection indicating high-intensity change on T2-weighted MRI. Multivariate logistic regression analysis was performed to determine the factors contributing to the severity of neurological deficits and back pain in the patients. Age, sex, level of fracture, duration after onset of symptoms, degree of local kyphosis, degree of angular instability, ratio of occupation by bony fragments, presence or absence of protrusion of flavum, and presence or absence of ossification of the anterior longitudinal ligament (OALL) in the adjacent level were used as explanatory variables, while severity of neurological deficits and back pain were response variables. On multivariate analysis, factors significantly affecting the severity of neurological deficits were angular instability of more than 15 degrees [adjusted odds ratio (OR), 9.24 (95% confidence interval, CI 1.49-57.2); P < 0.05] and ratio of occupation by bony fragments in the spinal canal of more than 42% [adjusted OR 9.23 (95%CI 1.15-74.1); P < 0.05]. The factor significantly affecting the severity of back pain was angular instability of more than 15 degrees [adjusted OR 14.9 (95%CI 2.11-105); P < 0.01]. On the other hand, presence of OALL in the adjacent level reduced degree of back pain [adjusted OR 0.14 (95%CI 0.03-0.76); P < 0.05]. In this study, pronounced angular instability and marked posterior protrusion of bony fragments in the canal were factors affecting neurological deficits. In addition, marked angular instability was a factor affecting back pain. These findings are useful in determining treatment options for patients with insufficient union following OVF.

Endoscopic vertebroplasty for the treatment of chronic vertebral compression fracture. Technical note.

The authors describe a new vertebroplasty technique for the treatment of chronic painful vertebral compression fractures (VCFs). A urinary balloon catheter is introduced into the vertebral body (VB) via a bilateral transpedicular approach and inflated with contrast medium to obtain sufficient space for endoscopic observation. The granulation tissue occupying the VB is then removed using a punch or curette inserted through one pedicle, with the guidance of an endoscope introduced through the contralateral pedicle. After endoscopic resection of granulation tissue in the fractured VB, vertebroplasty is performed by injecting calcium phosphate cement (CPC) into the VB. Fourteen patients in whom chronic painful VCFs were diagnosed underwent surgery involving the aforementioned technique. In all cases, intractable pain and ambulatory function improved after surgery, and there were no significant systemic complications. On radiological evaluation in eight cases in which the follow-up period exceeded 1 year, the mean height of the fractured VB improved from 38% of that of adjacent intact VBs to 85%. Although a slight loss of correction was routinely observed at 1 month postoperatively, an additional loss of VB height was not noted up to 1 year later. Bone formation was commonly seen along the anterior wall of the involved vertebrae in all cases. Vertebroplasty involving the endoscopic removal of granulation tissue proved to be an efficacious procedure for the treatment of chronic painful VCFs. The osteoconductive capacity of CPC facilitated callus formation and ultimately restoration of vertebral bone structure.

Trigger finger caused by an old partial flexor tendon laceration: a case report.

We report a rare case of trigger finger caused by an old partial laceration of the flexor digitorum superficialis. The triggering occurred five months after injury. This case was the latest presentation of triggering in the literature. The patient was managed by incising the A1 pulley and suturing the flexor tendon flap after trimming. He was relieved of triggering and there was no recurrence.