Masahiro Kanayama

Purpose Patients with ossification of the posterior longitudinal ligament (OPLL) may require lumbar surgery due to ossified lesions and degenerative changes. However, risk stratification for lumbar intervention remains underexplored. We aimed to identify predictors of lumbar surgery in patients with OPLL. Methods We retrospectively analyzed 178 OPLL patients who underwent whole-spine computed tomography (CT) (2007–2023). Patients were classified according to whether they underwent lumbar surgery. CT obtained prior to lumbar surgery or during conservative follow-up was reviewed. Imaging parameters, including ossification distribution and degenerative changes, were compared between groups and analyzed using multivariable logistic regression to identify independent predictors. Results Lumbar surgery was performed in 70 (39.3%) patients. The surgery group exhibited higher body mass index and greater prevalence of thoracolumbar ankylosis, thoracic and lumbar OPLL, lumbar ossification of the ligamentum flavum (OLF), and intervertebral disc (IVD) gas. Multivariable analysis identified lumbar OLF (OR, 6.49; 95% CI, 2.60–16.25) and lumbar IVD gas (OR, 5.75; 95% CI, 2.37–13.97) as independent risk factors. Coexisting OPLL and OLF at the same level was associated with younger surgical age and greater neurological severity. Conclusions Using whole-spine CT, we demonstrated that patients requiring lumbar surgery frequently exhibited a diffuse whole-spine ossification phenotype, characterized by thoracolumbar OPLL and ankylosis. Lumbar OLF and IVD gas were identified as independent risk factors; notably, lumbar OLF reflects this generalized ossification tendency, whereas disc gas indicates mechanical stress and degeneration. These findings support whole-spine CT–based risk stratification and longitudinal monitoring in patients with OPLL.

Background: Ossification of the posterior longitudinal ligament (OPLL) is relatively common in East Asian populations, with a recently revealed link to obesity. However, evidence linking OPLL with visceral fat obesity, which is prevalent in the Asian population, is insufficient. We aimed to examine the association between visceral fat obesity and the development of OPLL. Methods: In a single-center case-control study, data were collected from 120 Japanese patients diagnosed with OPLL and 91 controls without spinal ligament ossification identified during health screenings. From 2020 to 2023, all participants underwent computed tomography to assess visceral fat content and spinal ligament ossification. OPLL was classified as localized (cervical spine) or diffuse (thoracic/lumbar spine). Multivariable logistic regression was conducted to assess the effect size (odds ratio [OR]) of body mass index on the incidence of OPLL and to compare outcomes between groups with a high and low visceral/subcutaneous fat area (V/S) ratio. Results: The proportion of patients with visceral fat obesity was significantly higher in both the localized and diffuse OPLL groups than in the controls (58.9% vs. 64.1% vs. 25.2%, p < 0.05). Patients with OPLL had a higher rate of comorbid visceral fat obesity than the propensity score–matched controls did (56.8% vs. 18.1%, p < 0.001). The effect of BMI on the development of diffuse OPLL was 2.6-fold greater in the high V/S ratio group (OR, 9.50; 95% confidence interval [CI], 2.11 to 42.71) than in the low V/S ratio group (OR, 3.56; 95% CI, 1.51-8.37). Conclusions: Visceral fat obesity was associated with the development of OPLL, particularly diffuse OPLL. The modifying effect of visceral fat accumulation with overweight status was more strongly associated with diffuse OPLL than was that of subcutaneous fat combined with an overweight status. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Objective: To evaluate the preoperative and perioperative predictors of persistent leg numbness following lumbar fusion in patients aged ≥ 75 years.Methods: This single-center retrospective study examined 304 patients aged ≥ 75 years who underwent lumbar fusion for lumbar degenerative disease (102 men, 202 women; mean age, 79.2 [75–90] years). The visual analogue scale (VAS) score for leg numbness was examined preoperatively and at 2 years postoperatively. The persistent leg numbness group included patients with a 2-year postoperative VAS score for leg numbness ≥ 5 points. The demographic data were also reviewed. A multivariate stepwise logistic regression analysis was performed for variables with univariate analysis values of p < 0.2 on univariate analysis.Results: In total, 71 patients (23.4%) experienced persistent postoperative leg numbness. Multivariate logistic regression analysis revealed that a history of lumbar decompression, longer symptom duration, and a preoperative VAS score for leg numbness ≥ 5 points were associated with greater postoperative persistent leg numbness following lumbar fusion. In contrast, other factors, such as sex, body mass index, vertebral fracture, diabetes mellitus, depression, symptom duration, dural injury, operative time, and estimated blood loss, were not.Conclusion: A history of preoperative lumbar decompression, longer symptom duration, and greater preoperative VAS scores for leg numbness were preoperative predictors of persistent postoperative leg numbness following lumbar fusion in older patients. Although lumbar fusion is expected to improve leg numbness, surgeons should consider the surgical history, duration, and preoperative numbness intensity and explain the potential postoperative persistent leg numbness in advance.

Introduction: In the early phase of the coronavirus disease 2019 (COVID-19) pandemic, the importance of triaging surgeries was suggested to reduce burdens on the existing health system and maintaining service. The governor declared a state of emergency and requested that residents avoid going out unnecessarily (semi-lockdown) for the entire prefecture including our medical region from February 28 until May 25, 2020. However, for several spine patients, a significant delay in care may result in the progression of extremity weakness and pain. This study aimed to investigate trends of spine surgeries during the first COVID-19 semi-lockdown in the nonepidemic region in Japan.Methods: Spine surgeries performed in our institution from February 28 until May 25 between 2017 and 2020 were retrospectively reviewed and analyzed. We compared the number of spine surgeries and types of surgical spine pathologies between 2017 and 2019: previous years and 2020: a COVID-19 year.Results: The mean number of spine surgeries performed in previous years was 121 cases, and the number of spine surgeries performed in a COVID-19 year was 109 cases. The percentage of urgent surgeries was 19.6% in previous years versus 37.6% in a COVID-19 year; the difference was statistically significant (P<0.05). Among the urgent surgical spine pathologies, the prevalence of cauda equina or severe nerve root compression leading to progressive neurological deterioration or intractable pain was 20.2% in a COVID-19 year, which was significantly higher than 12.4% in previous years (P<0.05).Conclusions: The first COVID-19 semi-lockdown in Japan led to a decrease in elective cases and an increase in urgent cases and might affect progressive neurological deterioration for some spine patients even in a nonepidemic region.

Teriparatide (recombinant human parathyroid hormone 1–34) is increasingly used for the treatment of severe osteoporosis because it stimulates bone formation and may potentially enhance fracture healing. The objective of this study was to investigate the effects of teriparatide versus a bisphosphonate on radiographic outcomes in the treatment of osteoporotic vertebral compression fractures (OVCF). A total of 98 patients undergoing non-operative treatment for recent single-level OVCF were reviewed retrospectively. Thirty-eight patients were treated by a once-daily subcutaneous injection of 20 micrograms of teriparatide (TPD group), whereas 60 patients received 35 mg of alendronate weekly (BP group). Except for these medications, the same treatment protocol was applied to both groups. The radiographic assessments included union status, vertebral kyphosis, and mid-vertebral body height. The rates of fracture site surgical intervention were also compared between the two groups. The mean follow-up period was 27 months (median 22.5, range 2 – 75 months). Cox regression analysis showed that TPD reduced the time-to-union (adjusted relative hazard ratio: 1.86, 95% C.I.: 1.21 – 2.83). The union rate at six months after treatment was 89% in the TPD group and 68% in the BP group; the surgical intervention rate was significantly higher in the TPD group (p = 0.026, adjusted odds ratio: 8.15, 95% C.I.: 2.02 – 43.33). The change in local kyphosis was 4.6° in the TPD group and 3.8° in the BP group (p = 0.495, paired t-test). The change of mid-vertebral body height was 4.4 mm in the TPD group and 3.4 mm in the BP group (p = 0.228, paired t-test). Fracture site surgical interventions were not required in the TPD group; however, two patients in the BP group eventually underwent surgical treatment for symptomatic non-union or vertebral collapse. This retrospective study suggests that teriparatide may enhance fracture healing and improve the union rate in OVCF.

Study design: A retrospective study. Objective: The aim of the study was to review the treatment of deep wound infection after posterior instrumented lumbar fusion, and thereby to optimize the decision-making process of implant removal or retention on the basis of magnetic resonance imaging (MRI) assessment. Summary of Background Data: Biofilm formed on the surface of the spinal implant prevents infiltration of antibiotics and makes the infection treatment more complicated. The decision of implant removal, if necessary, should be made appropriately, but the problem is a lack of consensus for implant removal or retention. Methods: A total of 1445 consecutive patients who underwent posterior instrumented lumbar fusion were reviewed retrospectively. There were 23 deep wound infections (1.6%) requiring surgical treatment. MR images were used to evaluate the presence or absence of osteomyelitis of the instrumented vertebra and intervertebral abscess. Results: Six patients in the negative MRI group (n=7) were successfully treated by a single salvage surgery without implant removal; fusion occurred in 86% of the patients. However, in the positive MRI group (n=13), 4 patients required implant removal at the initial surgery and 5 patients eventually warranted implant removal after an average of 2.4 additional operations. Notably, 3 of the 4 patients who kept the implants ended up with a loss of fixation stability attributed to screw loosening with a progressive destruction of the instrumented vertebra. Therefore, the fusion rate was only 23% for the MRI-positive patients. Furthermore, making a wrong decision regarding implant removal increased the number of salvage surgeries and frequently resulted in progressive bone destruction and pseudarthrosis. Conclusions: Once vertebral osteomyelitis and/or intervertebral abscess were evident in MR images, all the hardware should be removed. Failure to adhere to this recommendation resulted in multiple additional failed operations, and ultimately pseudarthrosis with further bony destruction.

Peri-radicular injection is a widely used procedure for treating lumbar radicular pain, but it remains unclear what types of lumbar pathologies respond well to this treatment. We aimed to investigate the efficacy of peri-radicular injection for degenerative lumbar disorders and to determine what types of pathologies respond well to this treatment. We reviewed the records of 641 consecutive patients who underwent peri-radicular injection for degenerative lumbar pathologies with mean follow-up of 23.4 months. The pathologies included herniated disc in 286 patients, spinal stenosis in 141, degenerative spondylolisthesis in 136, failed back surgery in 24, isthmic spondylolisthesis in 22, degenerative scoliosis in 18, and foraminal stenosis in 14. Outcome measure was whether or not surgery is avoided by using peri-radicular injection. The rate of obviating surgery was determined in each pathology. Peri-radicular injection obviated surgeries in 331 patients (51.7 %). There were no complications related to the procedure, including neurological deterioration, infection, and haematoma. The rate of obviating surgery was 42.0 % in disc herniation, 52.9 % in degenerative spondylolisthesis, 67.4 % in spinal stenosis, 54.5 % in isthmic spondylolisthesis, 57.1 % in foraminal stenosis, 61.1 % in degenerative scoliosis and 54.1 % in failed back surgery. Poor outcomes were observed in herniated disc with spinal stenosis (17.9 % success), foraminal disc herniation (33.3 %), recurrent disc herniation (18.2 %) and failed back surgery with instability (33.3 %). This study demonstrated that 51.7 % of patients with degenerative lumbar pathologies were successfully treated by peri-radicular injection. Efficacy was limited in cases of herniated disc with spinal stenosis, foraminal disc herniation, recurrent disc herniation and failed back surgery with instability.

Balloon kyphoplasty (BKP) has been a well-accepted procedure in the treatment of osteoporotic vertebral compression fracture (OVCF), whereas it remains unclear whether or not this procedure has an impact on the global spinal alignment. The purpose of this study is to evaluate the effect of BKP on the global spinal alignment in OVCF. Fifty-six consecutive patients who had undergone BKP for symptomatic OVCF were retrospectively reviewed with a mean follow-up of 32 months. They were seven males and 49 females with a mean age of 75 years. Radiographic assessment was performed using upright whole spine radiographs. The parameters included vertebral kyphosis, mid-vertebral body height and global sagittal spinal alignment (C7 plumb line deviation). Clinical outcomes were evaluated using visual analog scale of back pain. Fifty-one of 56 patients (91.1 %) achieved immediate pain relief. Vertebral kyphosis significantly decreased from 18 to 14 degrees, but 43 patients (76.8 %) still had more than 10 degrees of local kyphosis. Subsequent vertebral compression fractures were observed in seven patients (12.5 %). Anterior deviation of a C7 plumb line (C7PL) was 3.1 cm pre-operatively, 3.1 cm postoperatively, and significantly increased to 5.9 cm at the final follow-up. Consistent results were obtained in those with pre-operative sagittal imbalance (>5 cm anterior deviation of C7PL) and with pre-existing OVCFs. BKP contributed to immediate pain relief, but did not improve the global sagittal spinal alignment after OVCF. This procedure should be solely indicated for painful OVCF or non-union, and could not be expected to restore the global sagittal alignment.

Hepatocellular carcinoma (HCC) is the third most common cause of cancer‑associated mortality worldwide. No effective treatment has been established for unresectable advanced HCC, and the prognosis is poor. Sorafenib is an oral multi‑targeted tyrosine kinase inhibitor for unresectable advanced HCC that significantly improves progression‑free and overall survival. However, in the two large phase III clinical trials (the SHARP and Asia‑Pacific trials), no cases of complete response (CR) were reported. The present study reports the case of a 68‑year‑old male with hepatitis C virus‑related cirrhosis and multiple recurrent HCCs, with a tumor thrombus of the third portal vein following resection. The patient received 400 mg once daily (half the standard dose) of sorafenib for two years and achieved a CR. At the most recent follow‑up examination at one year after the cessation of treatment, the patient was observed to be in remission without clinical or imaging evidence of disease recurrence.