Search

Abstract Background The current study aimed to evaluate the bone union rate between infected vertebrae after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis. Methods This retrospective multicenter cohort study evaluated 75 patients of posterior fixation for thoracolumbar pyogenic spondylitis that have been recorded at six relevant institutions from January 2016 to December 2022. Data on age, sex, location of infected vertebrae, number of infected disks, comorbidity, Pola classification, number of vertebrae fixed according to surgery, implant failure requiring revision surgery, and distance according to the type of infected vertebrae after surgery were evaluated. Further, their association with postoperative bone union was investigated > 12 months postoperatively. Results Finally, 40 patients were included in the study. In total, 32 (80%) patients achieved bone union at the infected vertebrae after minimally invasive posterior fixation without bone grafting. The mean duration from surgery to union was 10.7 months. Twenty-six (65%) patients initially achieved bone union at the lateral and/or anterior bridging callus. Patients with multiple-level infected disks (33%, 2/6 patients) had a lower bone union rate than those with a single-level infected disk (88%, 30/34 patients) (p = 0.0095). Conclusions In 80% of patients, bone union at the infected vertebrae was achieved after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis. A total of 65% of the patients achieved initial bone union at the lateral and/or anterior bridging callus. Moreover, patients with multiple-level infected disks had a low bone union rate. Hence, the treatment strategy should be cautiously considered. Trial registration This study was registered retrospectively and all procedures used in this study including the review of patient records were approved by the institutional review board.

Abstract Assessing intraoperative hemodynamics with Surgical Apgar Score (SAS) and preoperative nutritional status with the Controlling Nutritional Status (CONUT) score are said to be useful to predict postoperative complications in many surgical services, but little is reported in the field of spinal surgery. The purpose of this study was to assess the utility of SAS and the CONUT score for predicting the risk of major postoperative complications after spinal surgery. We included 659 people who undergone spinal surgery in our institute in eight consecutive years. The occurrence of postoperative major complications was investigated. Background clinical information, surgical information including the SAS and the CONUT score, and the length of postoperative hospital stay were collected. The risk factors of postoperative complications were assessed statistically. Complications occurred in 117 cases (17.8%). The multivariate analysis showed that history of diabetes mellitus (odds ratio [OR] 1.81: P = 0.035), coronary disease (OR 3.33; P = 0.009), American Society of Anesthesiologists Physical Status (OR 1.71; P = 0.025), use of instruments (OR 2.07; P = 0.026), operation time (OR 1.30; P

Study Design A post-hoc analysis of a prospective cohort study. Purpose This study aimed to identify factors at the time of injury associated with declining activities of daily living (ADLs) in the chronic phase of osteoporotic vertebral fractures (OVFs) managed conservatively. Overview of Literature Although a conservative approach is the treatment of choice for OVFs, ADLs do not improve or eventually decrease in some cases. However, the risk factors for ADL decline after the occurrence of OVFs, particularly the difference between those with or without initial bed rest, are unknown. Methods A total of 224 consecutive patients with OVFs aged ≥65 years who received treatment within 2 weeks after the occurrence of injury were enrolled. The patients were followed up for 6 months thereafter. The criteria for evaluating the degree of independence were applied to evaluate ADLs. Multivariable analysis with a logistic regression model was performed to evaluate the risk factors for ADL decline. Results In total, 49/224 patients (21.9%) showed a decline in ADLs. Of these, 23/116 patients (19.8%) in the rest group and 26/108 patients (24.1%) in the no-rest group experienced a decline in ADLs. In the logistic regression analyses, a diffuse low signal on T2-weighted magnetic resonance imaging (MRI) (odds ratio, 5.78; 95% confidence interval, 2.09–16.0; p=0.0007) and vertebral instability (odds ratio, 3.89; 95% confidence interval, 1.32–11.4; p=0.0135) were identified as independent factors in the rest and no-rest groups, respectively. Conclusions In patients with acute OVFs, a diffuse low signal on T2-weighted MRI and severe vertebral instability were independently associated with ADL decline in patients treated with and without initial bed rest, respectively.

Abstract Background Minimally invasive posterior fixation surgery for pyogenic spondylitis is known to reduce invasiveness and complication rates; however, the outcomes of concomitant insertion of pedicle screws (PS) into the infected vertebrae via the posterior approach are undetermined. This study aimed to assess the safety and efficacy of PS insertion into infected vertebrae in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis. Methods This multicenter retrospective cohort study included 70 patients undergoing minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis across nine institutions. Patients were categorized into insertion and skip groups based on PS insertion into infected vertebrae, and surgical data and postoperative outcomes, particularly unplanned reoperations due to complications, were compared. Results The mean age of the 70 patients was 72.8 years. The insertion group (n = 36) had shorter operative times (146 versus 195 min, p = 0.032) and a reduced range of fixation (5.4 versus 6.9 vertebrae, p = 0.0009) compared to the skip group (n = 34). Unplanned reoperations occurred in 24% (n = 17) due to surgical site infections (SSI) or implant failure; the incidence was comparable between the groups. Poor infection control necessitating additional anterior surgery was reported in four patients in the skip group. Conclusions PS insertion into infected vertebrae during minimally invasive posterior fixation reduces the operative time and range of fixation without increasing the occurrence of unplanned reoperations due to SSI or implant failure. Judicious PS insertion in patients with minimal bone destruction in thoracolumbar pyogenic spondylitis can minimize surgical invasiveness.

Study Design A retrospective, cross-sectional study was conducted to analyze the implications of asymmetric baseball movements on the incidence of spondylolysis. Purpose This study aimed to evaluate the relationship between asymmetric movements and the laterality of spondylolysis. Overview of Literature Baseball, characterized by its asymmetric throwing and batting, may disproportionately stress one side. Lumbar spondylolysis is a frequent cause of lower back pain in young athletes, particularly those involved in activities with consistent unilateral rotations such as baseball. However, whether a link exists between the laterality in spondylolysis and the dominant throwing/batting side or whether disparities exist between pitchers and fielders remains unclear. Methods The study included 85 players. Participants were divided into two groups: pitchers and fielders. The association between the laterality of spondylolysis and the throwing/batting side in the overall cohort and between the two groups was evaluated. Results Among pitchers, 16 lesions appeared on the throwing side and 32 on the nonthrowing side (p=0.029). For fielders, no notable difference was observed between the two sides (p=0.363). Furthermore, batting preference did not influence the laterality of spondylolysis in either group. Conclusions Adolescent baseball players, particularly pitchers, exhibited a higher incidence of lumbar spondylolysis on the side opposite their throwing arm. The findings of this study highlight the significant effect of asymmetrical sporting activities on the development of spondylolysis, to which pitchers are particularly susceptible.

Introduction: Conventional methods for analyzing vertebral rotation are limited to postoperative patients who underwent posterior fusion. A previous methodology calculated vertebral rotation using inverse trigonometric functions based on the length of the pedicle screw (PS). Accordingly, this study evaluates rotational deformity in patients with postoperative adolescent idiopathic scoliosis (AIS) using inverse trigonometric functions. Methods: This retrospective single-center study includes patients with AIS who underwent posterior fusion surgery. Postoperative radiography and computed tomography (CT) scans were retrospectively evaluated. The magnification ratio was calculated using the rod diameter (δ=lateral/frontal rod diameter), and the visible screw lengths were measured using radiographs. The rotation angle was calculated using the apex of the main curve and the lower instrumented vertebra (LIV) (rotation angle=tan-1 (lateral PS length/(δ×frontal PS length))) immediately following the surgery as well as two and five years postoperatively. The correlation between the direct CT measurement and postoperative rotation angle progression was investigated. The crankshaft phenomenon (CSP) and distal adding-on (DAO) were evaluated as postoperative deformities. CSP was defined as a 5° increase in rotation angle. Results: Seventy-eight patients (age: 15.3±2.0 years, eight boys and seventy girls) were included. The rotation angle was strongly correlated with CT rotation measurements (r=0.87). The mean rotation angle at the apex and LIV did not change within five years postoperatively (mean: 0.5±3.6° and 0.4±3.4°, respectively). CSP and DAO were observed in 6.4% and 3.8% of patients, respectively. Conclusions: The inverse trigonometric method is useful to quantitatively evaluate the postoperative rotation angle and identify CSP.

Introduction: Lateral lumbar interbody fusion (LLIF) techniques have been extensively used in adult spinal deformity surgery. Preoperative knowledge of the optimal position of the patient on the surgical table is essential for a safe procedure. Therefore, this study aims to determine the optimal angle for positioning the patient on the surgical table during LLIF using three-dimensional computed tomography (3DCT). Methods: Data from 59 patients (2 males, 57 females, mean age 66.3±8.6 years) with adult spinal deformities treated by performing corrective spinal surgery were included in this observational retrospective study. Simulated fluoroscopic images were obtained using 3DCT images rotated from the reference position with the spinous process of S1 as the midline to the position with the spinous process in the center of the bilateral pedicle of T12-L5. The rotation angle of each vertebra was measured and defined as the optimal rotation angle (ORA). The angle that bisected the angle between the maximum and minimum ORA was defined as the optimal mean angle of the maximum and minimum ORA (OMA) and considered the optimal angle for the patient's position on the surgical table, as this position could minimize the rotation angle of the surgical table during surgery. A multiple regression analysis was performed to predict OMA. Results: Multiple regression analysis revealed the following equation: OMA=1.959+(0.238×lumbar coronal Cobb angle)+(−0.208×sagittal vertical axis). Conclusions: When the patient is placed on the surgical table by rotating them at the OMA, the rotation of the surgical table can be reduced, ensuring a safe and efficient surgical procedure.

Introduction: The smiley face rod method is an effective treatment for symptomatic terminal-stage spondylolysis. However, the risk factors for treatment failure are unknown. We investigated the association of pars defect type with the treatment outcomes of this method. Methods: We retrospectively examined data from 34 patients (18.0±6.7 years) with terminal-stage spondylolysis who underwent surgery using the smiley face rod method. The mean follow-up period was 44.9±21.4 months. The patients were divided into 2 groups: pars defect without bone atrophy or sclerosis (group A; 18 patients), and with bone atrophy and sclerosis (group B; 16 patients). We evaluated and compared the visual analog scale (VAS) score for back pain, bone union rate, and time to return to preinjury athletics level between the groups. Fisher exact and paired t tests were used to compare the variables between groups. The VAS score between the groups was compared using a 2-factor repeated-measures analysis of variance. Results: Within groups, the VAS score was significantly different over time (p

Abstract Background Fifth lumbar vertebra (L5) spondylolysis has a lower bone union rate than non-L5 spondylolysis, but the reason for this is unknown. This study aimed to evaluate the differences in patient and lesion characteristics between L5 and non-L5 spondylolysis. Methods A total of 410 patients with lumbar spondylolysis aged 18 years or younger who were treated conservatively were enrolled. Patients and lesions were divided into L5 and non-L5 (L2–L4) spondylolysis. Factors, including sex, age, presence of spina bifida occulta, stage of the main side lesion, whether the lesion was unilateral or bilateral, presence and stage of the contralateral side lesion and treatment duration, were evaluated at the first visit and compared between the two groups. Results A total of 250 patients with 349 lesions were included. The bone union rate of L5 lesions was lower than that of non-L5 lesions (75% vs. 86%, p = 0.015). Patients with L5 spondylolysis were more likely to be male (86% vs. 66%) and younger (14.0 vs. 14.6 years) than patients with non-L5 spondylolysis. Lesions of L5 spondylolysis were more likely to be in a progressive stage (28% vs. 15%), less likely to be in a pre-lysis stage (28% vs. 43%) and more likely to be in a contralateral terminal stage (14% vs. 5.3%, p = 0.013) compared with lesions of non-L5 spondylolysis. Conclusions L5 spondylolysis was characterised by a lower bone union rate, more males, younger age, more progressive stage and more contralateral pseudarthrosis than non-L5 spondylolysis.

Introduction: This study aimed to determine whether the proximity of the median arcuate ligament (MAL) and the celiac artery (CA) changes in patients following surgery to correct adult spinal deformity (ASD). We hypothesized that the distance between the MAL and the CA shortens after corrective spinal surgery, which may cause acute celiac artery compression syndrome (ACACS). Methods: A total of 89 patients (68.4±7.6 years; 7 men/82 women) with ASD treated with spinal correction surgery were included in the present retrospective study. The level of the MAL, CA, and distance between the MAL and the CA (DMC) were determined via reconstructed computed tomography. MAL overlap was determined preoperatively and postoperatively. Results: The MAL and CA moved caudally following surgery. On average, after surgery, no changes in DMC were observed. We found preoperative MAL overlap in 32 (36%) patients, who also had postoperative MAL overlap. No patients showed any MAL overlap postoperatively. Conclusions: Contrary to our hypothesis, the distance between the MAL and the CA did not shorten, and emerging MAL overlap was not observed postoperatively.

Introduction: Lumbar spondylolysis is a common fatigue fracture of the pars interarticularis of the lamina of the lumbar spine in adolescent athletes presenting with pars clefts. Some pseudarthrotic lumbar spondylolysis causes low back pain or radiculopathy. This study presents a case of pseudarthrotic lumbar spondylolysis that was successfully treated using a modified smiley face rod technique. Technical Note: We developed a modified smiley face rod technique, which places pedicle screws in the lateral edge of the pedicle to preserve the erector spinae muscles and inserts a U-shaped rod between the spinous processes to preserve the supraspinous ligament. When a U-shaped rod penetrates the interspinous ligament subcutaneously, the resection of the supraspinous ligaments can be avoided. When the screw head is positioned more anterolaterally, a compression force is applied perpendicular to the surface of the pars cleft by rod clamping. This intrasegmental fusion technique preserves the mobile segment and simultaneously repairs the pars cleft. It is less invasive and more appropriate than interbody fusion for young athletes to avoid the possibility of future adjacent segment disorders. Conclusions: This is a minimally invasive procedure that can easily achieve bone fusion and should be introduced for patients who are suffering from the symptoms of pseudarthrotic lumbar spondylolysis.

Introduction: This study aims to investigate risk factors for cage subsidence following minimally invasive lateral corpectomy for osteoporotic vertebral fractures. Methods: Eight males and 13 females (77.2±6.0 years old) with osteoporotic vertebral fractures who underwent single corpectomy using a wide-footprint expandable cage with at least a 1-year follow-up were retrospectively included. The endplate cage (EC) angle was defined as the angle between the vertebral body's endplate and the cage's base on the cranial and caudal sides. A sagittal computed tomography scan was performed immediately after surgery and at the final follow-up, with cage subsidence defined as subsidence of 2 mm on the cranial or caudal side. Risk factors were analyzed by dividing cases into groups with (n=6) and without (n=15) cage subsidence. Results: No significant differences were noted in age, bone mineral density, number of fixed vertebrae, sagittal parameters, preoperative and final kyphosis angle, amount of kyphosis angle correction, bone union, screw loosening, and number of other vertebral fractures preoperatively and 1-year postoperatively between the two groups. No difference was noted in cranial EC angle, but a significant difference was noted in caudal EC angle in the group with (10.7±4.1°) and without (4.7±4.2°) subsidence (P=0.008). Logistic regression analysis with the dependent variable as presence or absence of subsidence showed that caudal EC angle (>7.5°) was a significant factor (odds ratio: 20, 95% confidence interval: 1.655-241.7, P=0.018). Conclusions: In minimally invasive lateral corpectomy for osteoporotic vertebral fractures, a cage tilted more than 7.5° to the caudal vertebral endplate is a risk factor for cage subsidence. The cage should be placed as perpendicular to the endplate as possible, especially to the caudal vertebral body, to avoid cage subsidence.

Introduction: The effect of spina bifida occulta (SBO) on bone union in lumbar spondylolysis is controversial. The study aim was to assess the effect of SBO on bone union after conservative treatment of L5 spondylolysis, the most common level. Methods: The study included 191 lesions in 145 patients (mean age, 14.0 years) with conservatively treated L5 spondylolysis. We examined the relationships between bone union after conservative treatment and the number of SBOs, levels, and single or multilevel status. Fisher's exact probability test, chi-square test, and Welch's T test were performed. Results: The SBO incidence was 53%, with at least one SBO at any vertebral level. SBO at S1 (p=0.034) or S2 (p=0.0003), two SBOs (p=0.0018), and three SBOs (p=0.011) were associated with a lower bone union rate. The bone union rate was significantly lower for lesions with SBOs at both S1 and S2 than without (42% vs. 79%; p

Abstract Background Lumbar spondylolysis, a common identifiable cause of low back pain in young athletes, reportedly has a higher incidence rate in males. However, the reason for its higher incidence in males is not clear. This study aimed to investigate the epidemiological differences between the sexes in adolescent patients with lumbar spondylolysis. Methods A retrospective study was conducted in 197 males and 64 females diagnosed with lumbar spondylolysis. These patients visited our institution from April 2014 to March 2020 with their main complaint being low back pain, and they were followed-up until the end of their treatment. We investigated associations between lumbar spondylosis, their background factors, and characteristics of the lesions and analyzed their treatment results. Results Males had a higher prevalence of spina bifida occulta (SBO) (p = 0.0026), more lesions with bone marrow edema (p = 0.0097), and more lesions in the L5 vertebrae (p = 0.021) than females. The popular sports disciplines were baseball, soccer, and track and field in males, and volleyball, basketball, softball in females. The dropout rate, age at diagnosis, bone union rate, and treatment period did not differ between the sexes. Conclusion Lumbar spondylolysis was more common in males than in females. SBO, bone marrow edema, and L5 lesions were more frequent in males, and sports discipline varied between the sexes.

Abstract Background Factors affecting bone union in the conservative treatment of adolescent lumbar spondylolysis remain controversial. We aimed to examine these factors along with advances in diagnostic imaging using multivariable analysis of a sufficient number of patients and lesions. Methods In this retrospective study, high-school-aged patients or younger (n = 514) who were diagnosed with lumbar spondylolysis from 2014 to 2021 were investigated. We included patients with acute fractures who showed signal changes around the pedicle on magnetic resonance imaging and who completed conservative treatment. The following factors were investigated at the initial visit: age, sex, level of lesion, main side stage, presence and stage of contralateral side lesion, and presence of spina bifida occulta. The association of each factor with bone union was evaluated through a multivariable analysis. Results Altogether, 298 lesions in 217 patients (174 boys and 43 girls; mean age: 14.3 years) were included in this study. Multivariable logistic regression analysis of all factors showed that the main side progressive stage was more likely associated with nonunion as compared to the pre-lysis (OR: 5.86; 95% confidence interval [CI]: 2.00–18.8; p = 0.0011) and early stages (OR: 3.77; 95% CI: 1.72–8.46; p = 0.0009). Regarding the contralateral side stage, the terminal stage was more likely to be associated with nonunion. Conclusion In the conservative treatment of lumbar spondylolysis, the factors affecting bone union were the main and contralateral side stages. Sex, age, level of lesion, or spina bifida occulta had no significant effects on bone union. The main, progressive, and contralateral side terminal stages were negative predictors of bone union. Trial registration This study was retrospectively registered.

Study Design Retrospective cohort study. Purpose To evaluate the clinical outcomes of the conservative treatment of “pre-lysis”-stage lumbar spondylolysis. Overview of Literature With the widespread use of magnetic resonance imaging (MRI) for early diagnosis of lumbar spondylolysis, a new disease stage called pre-lysis has emerged, in which intensity change is observed only on MRI without a fracture line on computed tomography. This study aimed to evaluate the clinical outcomes and factors unfavorable to bone healing of the conservative treatment of pre-lysis-stage lumbar spondylolysis. Methods Fifty-three patients with 57 fresh pre-lysis-stage lesions who had completed conservative treatment were included in the study (40 men, 13 women; mean age, 14.3 years). We investigated the rate of bone healing and the relationship between bone healing after conservative therapy and factors such as age, sex, vertebral level, unilateral/bilateral lesions, and presence of spina bifida occulta. Results The overall bone healing rate was 95% (54/57 lesions). Bilateral lesions had a significantly lower bone healing rate than unilateral lesions (86% vs. 100%, p=0.046). There were no statistically significant differences based on age, sex, vertebral level, or presence of spina bifida occulta. Conclusions The bone healing rate in unilateral lesions was 100%, which was significantly higher than that in bilateral lesions. It is important to detect and initiate treatment while the lesion is still unilateral, if possible.

Abstract Although the incidence of cervical spinal cord injury (CSCI) with ossification of the posterior longitudinal ligament (OPLL) has increased in older adults, its etiology and neurological outcomes remain unknown. We identified OPLL characteristics and determined whether they influence neurological severity and improvement of CSCI in older patients. This multicenter retrospective cohort study identified 1512 patients aged ≥ 65 years diagnosed with CSCI on admission during 2010–2020. We analyzed CSCI etiology in OPLL patients. We performed propensity score-adjusted analyses to compare neurological outcomes between patients with and without OPLL. Cases were matched based on variables influencing neurological prognosis. The primary neurological outcome was rated according to the American Spine Injury Association (ASIA) impairment scale (AIS) and ASIA motor score (AMS). In 332 OPLL patients, the male-to-female ratio was approximately 4:1. Half of all patients displayed low-energy trauma-induced injury and one-third had CSCI without a bony injury. Propensity score matching created 279 pairs. There was no significant difference in the AIS grade and AMS between patients with and without OPLL during hospitalization, 6 months, and 12 months following injury. OPLL patients tended to exhibit worse neurological findings during injury; nevertheless, OPLL was not associated with poor neurological improvement in older CSCI patients.

Introduction: Magnetic resonance imaging (MRI) is widely used in orthopedics, but orthopedic surgeons, including spine surgeons, do not have detailed knowledge of MRI-related accidents. We, as orthopedic surgeons, investigated the details of medical accidents related to ferromagnetic objects brought into the MRI room using a national multicenter database. Methods: We conducted an exploratory analysis of accidents involving MRI ferromagnets based on the Japanese database of adverse medical occurrences. From a total of 104,659 accident reports over nine years, 172 involving the presence of ferromagnetic objects in the MRI room were extracted and analyzed. Results: The accident reports frequently involved children and the elderly. Nurses filed the highest number of reports (44.8%) by occupation, which was more than twice as many as physicians (19.8%). The most common ferromagnetic devices brought into the MRI rooms were pacemakers (n = 22). There were also large magnetic objects such as oxygen cylinders (n = 12) and IV stands (n = 7). In the field of orthopedics, ankle weights (n = 4), pedometers (n = 3), and artificial limbs (n = 2) were brought in. “Failure to check” was the most common cause of accidents (69%). Actual harm to patients occurred in 9% of cases, with no fatalities. Conclusions: Manuals and checklists should be developed and continuous education provided to prevent accidents involving magnetic objects brought into the MR scanner room. As orthopedic surgeons, including spine surgeons, we should be cautious with emergency, geriatric, and pediatric patients because their information and medical history may not be accurate. We should not overlook equipment commonly found in orthopedic practice such as ankle weights and pedometers.

Introduction: Lumbar spondylolysis typically arises during adolescence, whereas its onset in adulthood is rare. Several studies have reported incidentally identified terminal-stage spondylolysis in adults, but only one case series has investigated acute lumbar spondylolysis lesions with bone marrow edema in adults. Methods: We retrospectively investigated lumbar spondylolysis in patients aged 18 years or older. Age at diagnosis, sex, competitive sporting level, and competitive sporting discipline were investigated in each patient. The level of the affected vertebra, pathological stage, bone union, and treatment period were analyzed for each lesion. Results: The study included nine patients (eight males and one female), aged 18-22 years old, with 14 acute lumbar spondylolysis lesions. Four patients were soccer players (two professionals, and two amateurs), four were amateur track and field athletes, and one was an amateur basketball player. The affected vertebral levels were L3 in two lesions, L4 in seven lesions, and L5 in five lesions. The pathological stage was pre-lysis stage in two lesions, early stage in eight lesions, and progressive stage in four lesions. Ten lesions achieved bone union with conservative therapy. The average treatment period was 84.7 days. Conclusions: The adult-onset lumbar spondylolysis patients were young, up to their early 20s, and generally professional sportspeople performing at an elite level. Most of them were performing a sport that has been reported to have a high risk of causing lumbar spondylolysis. L4 was the most affected vertebral level in contrast to L5, which has been reported in adolescent lumbar spondylolysis. Bone union was achieved for most lesions with conservative therapy.

Abstract Occasionally lumbar spondylolysis in adolescents will recur after conservative treatment. The goal of this study was to retrospectively review the conditions in which recurrence transpired in a subset of adolescent patients diagnosed with acute lumbar spondylolysis. A retrospective survey was conducted in 141 patients who had been treated for spondylolysis and had obtained bone union. Twenty subjects were selected who had recurrent lumbar spondylolysis after returning to sports activity following the initial spondylolysis treatment. There were 18 males and two females with an average age at the time of initial visit of 13.3 years and 14.1 years at the time of recurrence. The average period of initial treatment was 101 days, and the average time to recurrence after healing was 149 days. There were three cases at L3, two cases at L4 and 15 cases at L5. At recurrence, 18 patients had unilateral involvement and two patients presented with bilateral occurrence. Four cases did not achieve bony union. In this study, the recurrence rate was 13.2%. Eighty percent of cases had recurrence within six months after healing. After recurrence, 20% of the cases reached pseudoarthrosis. It is useful to take regular MRI images to detect recurrence within six months after returning to sports.

Introduction: Vertebral instability (VI) in osteoporotic vertebral fractures (OVFs) varies from mild to severe. The relationship between the VI of OVFs and independent factors, such as bone mineral density (BMD) and lumbar muscle volume, is unclear. This study aimed to investigate whether BMD and the cross-sectional area (CSA) of lumbar muscles are related to VI in OVFs. Methods: On the basis of the thoracolumbar lateral radiographs of 95 acute OVFs in postmenopausal women (mean age 80.6 years; range: 64-103 years), supine and standing vertebral collapse rates (CRsp and CRst, respectively) were determined. Subsequently, VI was defined as follows: VI=CRst−CRsp. Using axial T2-weighted magnetic resonance imaging (MRI), CSA of the psoas major, erector spinae, and multifidus muscles at the L3/4 intervertebral disc level were measured. The BMD of the lumbar spine and proximal femur (total hip) was measured for all participants using dual-energy X-ray absorptiometry. The patients were classified into group 1 (VI

Study Design Retrospective cohort study Purpose To examine bone healing with conservative treatment in cases of adolescent bilateral L5 spondylolysis. Overview of Literature We classified bilateral L5 spondylolysis, which is the most affected spinal level, by fracture stage and aimed to compare the bone healing rate according to the fracture stage and evaluate the presence of a preexisting contralateral terminal fracture at the diagnosis of fresh spondylolysis. Methods We evaluated 48 patients (38 boys and 10 girls) with bilateral L5 spondylolysis diagnosed during or before high school. L5 spondylolysis was classified into two groups: fresh group (bilateral fresh spondylolysis cases), and terminal group (cases wherein one side had fresh spondylolysis and the contralateral side had terminal spondylolysis). We investigated the age of examination and bone healing rate in both groups. We investigated progressive-stage lesions and bone healing rate with or without progressive-stage lesions. Results The bone healing rate in the fresh group was significantly higher than that in the terminal group 72.0% vs. 26.1%, p=0.003). In both the groups, the bone healing rate was significantly higher in patients without progressive-stage lesions than in those with progressive-stage lesions. Conclusions Bone healing of progressive-stage fresh spondylolysis was not achieved by conservative treatment when contralateral terminal spondylolysis was present in adolescents with bilateral L5 spondylolysis. Our results suggest that bilateral L5 spondylolysis treatment strategies must be determined based on the combination of the stages present.

Abstract Three types of sacral alar fatigue fractures are elderly, postnatal, and sport-related. They are most prevalent in athletes during adulthood; there are few reports of sacral alar fatigue fractures in young athletes. The purpose of this study was to analyze sacral alar fatigue fractures in adolescent athletes. Of the 920 patients hospitalized with low back pain, 13 were diagnosed with sacral alar fatigue fractures with magnetic resonance imaging (MRI) abnormalities. We investigated age, sex, sports discipline, span from symptom onset to consultation, laterality, complication with spondylolysis, computed tomography (CT) findings, and treatment span. The average age was 14.5 years old (8-men and 5-women). The most frequent discipline was basketball. The span to consultation was 13.2 days. The number of right-side cases was 9. Seven cases were complicated by bilateral spondylolysis. MRI abnormalities were observed in all the cases. Only two patients showed abnormal findings on CT. Averagely 67 days after treatment, participants returned to their sports. Sacral alar fatigue fractures suggest that the span from onset to consultation is short. Fracture lines are often unclear on CT, and MRI is useful for diagnosis. More than half of the cases in this study were complicated by lumbar spondylolysis.

Abstract Background If bone union is expected, conservative treatment is generally selected for lumbar spondylolysis. However, sometimes conservative treatments are unsuccessful. We sought to determine the factors associated with failure of bony union in acute unilateral lumbar spondylolysis with bone marrow edema including contralateral pseudarthrosis. Methods This study targeted unilateral lumbar spondylolysis treated conservatively in high school or younger students. Conservative therapy was continued until the bone marrow edema disappeared on MRI and bone union was investigated by CT. We conducted a univariate analysis of sex, age, pathological stage, lesion level complicating the contralateral bone defect, lesion level, and intercurrent spina bifida occulta, and variables with p