Bone fusion is one of the mainstay managements for degenerative spinal diseases and critical-sized bone defects resulting from trauma, tumors, infection, and nonunion. Bone graft materials are required for promoting bone healing, with autografts historically considered the gold standard due to their osteogenic, osteoinductive, and osteoconductive properties. However, donor site morbidities have led to the development of alternative bone graft substitutes. Currently available alternative options for bone fusion include allografts, ceramics, demineralized bone matrix (DBM), and bone morphogenetic proteins (BMPs). Each material has its advantages and disadvantages. Allografts avoid donor site morbidities but lack osteogenic properties and pose disease transmission risks. DBMs are acid-extracted allografts that have osteoconductive and osteoinductive properties but require combination with autografts because of the lack of evidence for their stand-alone use. BMP-2 has potent osteoinductive properties and is considered an ideal fusion material, but faces unresolved challenges related to optimal dosage and carrier. Synthetic peptides, mimicking the cell-binding domain of type I collagen, facilitate the attachment of osteogenic cells (such as osteoblasts) to the graft material and the production of extracellular matrix, leading to improved bone growth at the fusion site. The development of materials with ideal properties is a research hotspot. Recent advancements in biomaterials, such as hydrogels, nanomaterials, and three-dimensional-printed biomaterials, offer promising future options for bone fusion. This review provides an overview of available bone fusion materials, their advantages and disadvantages, and introduces emerging candidate options for bone fusion.

Background/Objectives: Despite the increasing prevalence of both spinal stenosis and obesity, their association remains controversial. This study aimed to investigate the relationship between body mass index (BMI) and the risk of lumbar spinal stenosis in the Korean population using nationwide data. Methods: We analyzed data from 2,161,684 adults aged ≥40 years who underwent health examinations in 2009 using the Korean National Health Insurance System database. Participants were categorized by BMI into five groups: underweight (<18.5), normal weight (18.5–22.9), overweight (23.0–24.9), obesity class I (25.0–29.9), and obesity class II and above (≥30). Cox proportional hazards models were used to evaluate the association between BMI and lumbar spinal stenosis risk, adjusting for demographic characteristics, lifestyle factors, and comorbidities. Results: During the 10-year follow-up period, the incidence rate of lumbar spinal stenosis increased progressively with higher BMI categories, from 32.77 per 1000 person-years in the underweight group to 51.51 in the obesity class II and above group. In the fully adjusted model, compared to the normal weight group, the hazard ratios (95% confidence intervals) were 0.801 (0.787–0.815) for underweight, 1.132 (1.126–1.139) for overweight, 1.245 (1.238–1.252) for obesity class I, and 1.348 (1.331–1.366) for obesity class II and above. The association was stronger in females and participants aged <65 years. Conclusions: A higher BMI was independently associated with an increased risk of lumbar spinal stenosis in the Korean population. This association remained robust after adjusting for various confounding factors, suggesting BMI as a significant risk factor for spinal stenosis.

Background and Objectives: Lumbar spinal stenosis (LSS) is a leading cause of disability in older adults, but the role of cigarette smoking in its development remains unclear. This study aimed to clarify the association between smoking and the incidence of LSS, with a focus on dose–response relationships and subgroup variations by age and sex. Methods: We conducted a nationwide, population-based cohort study using the Korean National Health Insurance Service database. A total of 2,123,268 adults aged ≥ 40 years who underwent health screening in 2009 were followed until LSS diagnosis, death, or 2020. Smoking status, duration, daily consumption, and pack-years were assessed. Cox proportional hazards models with progressive adjustment for demographic, lifestyle, and clinical factors were applied. Results: Over a mean follow-up of 8.2 years (17.5 million person-years), 721,909 new cases of LSS were identified. Fully adjusted models showed higher risk in former (HR 1.047; 95% CI, 1.039–1.056) and current smokers (HR 1.052; 95% CI, 1.044–1.060) compared with never smokers. A clear dose–response pattern was observed, with the greatest risk in heavy smokers (≥40 pack-years; HR 1.207; 95% CI, 1.191–1.222). Subgroup analyses indicated stronger associations among adults aged ≥ 65 years and in women. Conclusions: Cigarette smoking was independently associated with an increased risk of LSS, with risk increasing according to lifetime exposure. The findings underscore the importance of smoking cessation strategies to reduce the burden of spinal degeneration, especially in older adults and women.

An abdominal pseudohernia is a rare clinical entity that consists of an abnormal bulging of the abdominal wall that can resemble a true hernia but does not have an associated underlying fascial or muscle defect. Abdominal pseudohernia is believed to result from denervation of the abdominal muscles in cases of herpes zoster infection, diabetes mellitus, lower thoracic or upper lumbar disc herniation, surgical injuries, and rib fracture. To date, nine cases of abdominal pseudohernia caused by disc herniation at the lower thoracic or upper lumbar levels have been reported. A 35-year-old man with no underlying disease or traumatic event presented with chief complaints of left flank pain and a protruding left lower abdominal mass that had formed one day earlier. There was no true abdominal hernia on abdominal computed tomography (CT), although CT and magnetic resonance imaging (MRI) showed a herniated soft (non-calcified) disc into the left neural foramen at the T11-12 level. A nonsteroidal anti-inflammatory drug was prescribed for the flank pain, and the patient was followed on a regular basis for six months. Follow-up MRI taken at the last visit showed complete resorption of the herniated disc. Abdominal pseudohernia and flank pain were also completely resolved. We report a rare case of monoradiculopathy-induced abdominal pseudohernia caused by foraminal soft disc herniation at the T11-12 level. In patients who have an abdominal pseudohernia without herpes zoster infection, diabetes mellitus, or traumatic events, lower thoracic disc herniations should be included in differential diagnosis.

Rationale: The incidence of snapping popliteus tendon syndrome, a type of lateral knee snapping, is not high, so making an accurate diagnosis is difficult. A proper treatment following an accurate diagnosis is essential for improvement. Very few cases have been reported of its treatment. Patient concerns: An 18-year-old male patient had experienced painful popping in the lateral part of the knee during knee flexion for 3 years before his hospital visit. Diagnoses: Snapping popliteus tendon syndrome. Interventions: The patient underwent an all-arthroscopic surgery. Tendon debulking and tissue debridement around the popliteus tendon was conducted, but the snapping did not resolve. The enlarged tubercle was excised through an arthroscopic procedure using a burr, and the surgery was finished after confirming that snapping was resolved. Outcomes: Full range of motion (ROM) was recovered 6 weeks after surgery and the snapping did not recur. Lessons: Snapping popliteus tendon syndrome is a disease that is hardly recognized due to its low prevalence and difficulty in diagnosis, and it requires close observation of the patient before surgery. The location of the tenderness and the snapping occurrence must also be carefully identified. Our procedure is an entirely arthroscopic technique; as it has the prominent advantage of a speedy recovery and easy rehabilitation, it could also be helpful to set treatment standards for this disease in the future.

Destructive spondyloarthropathy (DSA) is one of the major complications in patients undergoing long-term hemodialysis. To the best of our knowledge, an epidural abscess occurring at the level of preexisting cervical DSA has not been well described in the literature. We report a unique case of quadriplegia caused by an epidural abscess occurring at the same level of preexisting cervical DSA. A 49-year-old woman was transferred to our emergency department with 5 days of sepsis, drowsy mental status, and quadriplegia below the C5 level. The patient had a medical history of hemodialysis for 10 years. Magnetic resonance imaging showed spinal cord compression by an epidural abscess at the level of preexisting cervical DSA. Blood culture revealed methicillin-sensitive Staphylococcus aureus. Infection of the arteriovenous (AV) shunt was considered as the primary focus of sepsis and pyogenic spondylitis. We performed an emergent open door laminoplasty and the vascular team debrided the infected AV shunt site. Approximately 8 months after surgery, the patient was able to perform activities of daily living somewhat independently. Emergent surgical decompression and intensive medical care led to successful recovery from a septic and quadriplegic state in this patient. When diagnosing a patient who has undergone long-term hemodialysis presenting with neurologic deficits, the possibility of infectious spondylitis at the same level as DSA should be considered.