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.

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.

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.

Objective: Osteoporotic vertebral fracture (OVF) is conventionally treated with conservative management such as bed rest, but a relatively prolonged bed rest has the potential risk of muscle disuse atrophy. This study aimed to examine whether the 2-week of rigorous bed rest affects muscle disuse atrophy in OVF patients.Patients and Methods: A total of 54 OVF patients (16 males; 38 females; mean age, 80.2 ± 9.2 years) were treated with an initial 2-week rigorous bed rest by hospitalization with persistent rehabilitation. Cognitive function, swallowing function, grip strength, and lower extremity circumference were evaluated at three-time points (admission, end of bed rest, and discharge).Results: Of the 51 patients who were able to walk independently before the injury, one patient (2.0%) had to use a wheelchair after the injury. During hospitalization, cognitive function decline was observed in 33.3% of patients, but not in patients with Revised Hasegawa’s Dementia Scale score ≥25 at admission. Swallowing function decline was observed in one patient, and none of the patients developed aspiration pneumonia during hospitalization. The grip strength significantly improved both at the end of bed rest (P=0.04) and discharge (P=0.02). Although the lower extremity circumference significantly decreased at the end of bed rest (P<0.01), it was recovered afterward. The lower extremity circumference did not significantly differ between the admission and discharge (P=0.17).Conclusion: Our results suggested that conservative treatment of OVF through an initial 2-week rigorous bed rest with persistent hospital rehabilitation poses a low risk of muscle disuse atrophy. If cognitive dysfunction is observed on admission, close monitoring for exacerbation should be performed during the hospital stay.

Objective: Lumbar spondylolysis, caused by stress fracture of the pars interarticularis may lead to a bony defect or spondylolisthesis. In adolescents, its surgical treatment employs the smiley face rod method for direct reduction of pseudoarthrotic spondylolysis and spondylolisthesis. Clinical outcomes of this treatment have been occasionally described; however, implant removal has not been discussed previously. We present a patient with lumbar spondylolysis with grade 1 slip at the 5th lumbar vertebra (L5) per the Meyerding classification.Patient: A 14-year-old boy presented with chronic severe lower back pain. Since conservative therapy did not resolve pain or enable resuming sports activities, the smiley face rod repair was performed 7 months after the initial treatment.Result: Anterior slippage of the L5 was surgically reduced. The patient wore a brace for 3 months postoperatively, and partial bone fusion was noted 6 months postoperatively. He resumed his sports activity 8 months postoperatively, and absolute bone fusion was confirmed 18 months postoperatively. Implant removal was performed 3 years postoperatively. Grade 1 slip was corrected with absolute bone fusion, and long-term follow-up revealed good results in terms of healing and rehabilitation.Conclusion: Smiley face rod method that allows for implant removal after bone fusion is suitable for adolescents.

Objective: The aim of this study was to determine the prevalence of curable and pseudoarthrosis stages of adolescent lumbar spondylolysis under high school students complaining of and seeking medical consultation for low back pain.Patients and Methods: We analyzed age, sex, morbidity, presence of spina bifida occulta (SBO), and competitive sport discipline of patients with lumbar spondylolysis. We then stratified their pathological stage using a modified classification system via magnetic resonance imaging and computed tomography.Results: Of 507 patients, 451 lesions in 268 patients were diagnosed with lumbar spondylolysis (average age, 14.7 years; sex ratio, 215:53 male/female). Morbidity levels were as follows: L1, 1 lesion in 1 patient; L2, 9 lesions in 5 patients; L3, 38 lesions in 25 patients; L4, 106 lesions in 74 patients; L5, 297 lesions in 189 patients, and SBO verified in 111 patients. A total of 264 patients played a specific sport: baseball, 93; soccer, 49; volleyball, 21; track and field, 21; basketball, 20; others, 164. The prevalence of curable- and pseudoarthrosis-stage lumbar spondylolysis was 206 lesions in 142 patients, and 141 lesions in 87 patients, respectively.Conclusion: With 59.3% of patients having curable-stage lumbar spondylolysis, adolescent athletes with low back pain are urged to seek consultation. Furthermore, clinicians should perform magnetic resonance imaging to avoid misdiagnosis.

Purpose: This study aimed to examine the characteristics of lumbar spondylolysis with acute lumbar spondylolysis on one side and pseudoarthrotic spondylolysis on the other, relative to acute lumbar spondylolysis on one side only.Patients and Methods: Short-tau inversion recovery images obtained through magnetic resonance imaging were used to diagnose 58 patients with acute lumbar spondylolysis with bone marrow edema on one side only. A total of 20 patients who had pars defects on the contralateral side (terminal-stage pseudoarthrotic spondylolysis) were included in the contralateral pseudoarthrosis group (P group). The remaining 38 patients with normal images for the contralateral pars interarticularis were included in the unilateral lesion group, in which the contralateral side was normal (U group). We investigated the union rate, age, sex, lesion laterality, vertebral level, pathological stage, and existing spina bifida occulta in both groups.Results: The P group was characterized by a higher proportion of right-side cases, L5 lesions, more progressed pathological stage, and spina bifida occulta and a significantly lower union rate than the U group.Conclusion: The union rate in patients with lumbar spondylolysis with acute lumbar spondylolysis on one side and pseudoarthrotic spondylolysis on the opposite side was only 15%. We should inform patients with acute unilateral spondylolysis lesions and contralateral pseudoarthrosis about this poor union rate and urge them to choose their therapy accordingly.