Update: This article was updated on October 19, 2022, because of previous errors, which were discovered after the preliminary version of the article was posted online. On page 1787, in the legend for Figure 2, the sentence that had read “The vertebral collapse rate (in %) was defined as 1 − (A/P) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images.” now reads “The vertebral collapse rate (in %) was defined as (1 − [A/P]) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images.” On page 1788, in the section entitled “Data Collection,” the sentence that had read “The vertebral collapse rate (in %) was defined as 1 − (anterior vertebral wall height/posterior vertebral wall height) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images⁹.” now reads “The vertebral collapse rate (in %) was defined as (1 − [anterior vertebral wall height/posterior vertebral wall height]) × 100, and vertebral instability (in %) was defined as the difference in vertebral collapse rate between the loaded and non-loaded images⁹.” Finally, on page 1791, in Table IV, the footnote for the “Primary outcome” row that had read “N = 113 in the rest group and 99 in the no-rest group.” now reads “N = 116 in the rest group and 108 in the no-rest group.” Background: Although imaging findings that predict resistance to conservative treatment in patients with osteoporotic vertebral fracture (OVF) have recently been reported, no conservative treatment method has been standardized. In this study, the effects of initial bed rest on the outcomes of patients with OVF and in patients with and without poor prognostic findings on magnetic resonance imaging (MRI) were compared. Methods: This prospective cohort study at 2 facilities involved consecutive patients aged ≥65 years with OVF who began treatment within 2 weeks after their injury and were observed for 6 months. Patients at one hospital rested for 2 weeks (116 patients; mean age, 80.4 years), whereas those at the other hospital were not instructed to rest (108 patients; mean age, 81.5 years). Patients were further divided according to the presence or absence of poor prognostic MRI findings. The primary end point was the rate of transition to surgery; secondary end points included bone union rate, vertebral collapse progression, local kyphosis progression, and changes in activities of daily living (ADL). Results: Forty-five patients in the rest group (including 3 who required surgery) and 37 patients in the no-rest group (including 9 who required surgery) had poor prognostic MRI findings. Although the difference in the rate of transition to surgery between the rest and no-rest groups did not reach significance among all patients (p = 0.06), the transition rate in the rest group was significantly lower (p = 0.02) in the patients with poor prognostic MRI findings. Both the bone union rate and changes in ADL were not significantly different between the rest and no-rest groups. The mean vertebral collapse progression was 6.4% in the rest group and 20.9% in the no-rest group (p < 0.001), and the mean local kyphosis progression was 2.4° in the rest group and 8.8° in the no-rest group (p < 0.001). Conclusions: Although bed rest is not recommended for all patients, hospitalized bed rest for 2 weeks reduced the number of patients with OVF who require surgery among patients with poor prognostic MRI findings. Bed rest also reduced progression of vertebral collapse and kyphosis, regardless of the MRI findings. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Introduction: The smiley face rod method is an effective treatment for symptomatic terminal-stage spondylolysis. How-ever, the risk factors for treatment failure are unknown. We investigated the association of pars defect type with the treat-ment outcomes of this method. Methods: We retrospectively examined data from 34 patients (18.0 +/- 6.7 years) with terminal-stage spondylolysis who un-derwent surgery using the smiley face rod method. The mean follow-up period was 44.9 +/- 21.4 months. The patients were di-vided into 2 groups: pars defect without bone atrophy or sclerosis (group A; 18 patients), and with bone atrophy and sclero-sis (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<0.001). The VAS scores between groups were not significantly different. Patients in group A had a significantly higher bone union rate per pars at 6 months (group A, 65.7%; and group B, 37.5%, p=0.028) and 24 months after surgery (group A, 97.1%; and group B, 75.0%, p=0.011). All patients returned to their respective sports, and no significant differences were observed in the time to return to preinjury athletics level between the groups (p=0.055) Conclusions: The type of pars defect are associated with bone union after the smiley face rod method, but have little ef-fect on postoperative symptoms.

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: 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 <20%) and group 2 (VI ≥20%).Results: We observed a negative correlation between VI and CSA of the erector spinae muscle (r = −0.3962, P < 0.0001). No significant correlations were observed between VI and BMD. The CSA of the erector spinae muscle in group 2 was significantly lower than that in group 1 (P = 0.0002). No significant difference in the BMD or the CSA of the psoas major or multifidus muscles was observed between the two groups. A multivariable analysis of factors of VI was performed. Both age (odds ratio [OR], 1.099; 95% confidence interval [CI], 1.015–1.189; P = 0.020) and the CSA of the erector spinae (OR, 0.996; 95% CI, 0.993–0.999; P = 0.020) were significant predictors of high VI.Conclusions: Although the severity of OVFs was related to the CSA of the erector spinae muscle, it was not associated with BMD.

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.