Rationale: Lipomas are tumors composed of mature adipocytes, originating from the mesoderm, and are the most common soft tissue tumor. According to the World Health Organization classification of human soft tissue and bone tumors, there are 14 types of benign tumors, including mature adipose tissue. Osteolipoma is known as the rarest subtype of lipoma. Patient concerns: A 63-year-old female presented to our hospital for the evaluation and treatment of a palpable mass with pain in the right knee. Diagnosis: The diagnosis was confirmed as lipoma with osteocartilaginous metaplasia. Interventions: Surgical removal of the tumor was performed. Outcomes: The main symptoms improved immediately after the surgery and recovered without any complications or recurrence until 2 years after surgery. Lessons: Lipoma with osteochondral degeneration is a rare variant of lipoma and it is important to differentiate it from other malignant tumors. Pathological confirmation should be performed after marginal resection of the mass.

Purpose: The distal radioulnar joint (DRUJ) at the wrist facilitates pronation and supination, and both bone structure and soft tissues contribute to its stability. This study analyzed the characteristics of patients with traumatic posterior DRUJ injuries and examined the clinical outcomes of open or arthroscopic treatment methods for these patients. Methods: A retrospective cohort study was conducted on 14 patients with traumatic posterior DRUJ instability, excluding those with associated radius fractures. The study evaluated patient demographics, injury mechanisms, radiologic findings (DRUJ relationship in the coronal plane, sigmoid notch in the axial plane, the presence and location of an accompanying distal ulnar fracture, and ulnar variance in the opposite wrist), and clinical outcomes (visual analog scale, Disability of Arm, Shoulder, and Hand [DASH] score, and range of motion [ROM]). Patients were treated with either open repair or arthroscopic methods, and postoperative results were monitored over an average of 8.8 months. Results: Ten patients had ulnar styloid fractures, with most occurring at the base or more proximally. The sigmoid notch was classified as the flat-face type in nine cases (64.3%) and the ski-slope type in five cases (35.7%). The clinical outcomes were favorable, with no significant differences between the open and arthroscopic groups regarding pain levels, DASH scores, and ROM. Conclusion: Both treatment methods can achieve favorable clinical outcomes in managing traumatic posterior DRUJ instability.

Objectives: This study aimed to investigate the relationship between the sarcopenia index (SI), which is derived from serum creatinine and cystatin C levels, and osteoporosis in chronic kidney disease (CKD). Methods: This study initially included patients who underwent dual-energy X-ray absorptiometry (DXA) and serum creatinine and cystatin C testing between 2005 and 2022. Subsequently, patients diagnosed with CKD were selected for the final analysis, totaling 102 patients. Both traditional and new SI were calculated, with each participant categorized into one of two groups (non-osteoporosis and osteoporosis) according to bone mineral density. To enhance statistical validity, the patients were further divided into low- and high-index groups based on the median value of both indices for comparative analysis. The association between SI and the risk of osteoporosis was estimated using multivariable logistic regression analysis. Results: Participants with lower SI values had lower bone mineral density and a higher diabetes mellitus prevalence. The non-osteoporotic group exhibited significantly higher mean values for both traditional and new SI. Multivariable logistic regression analysis identified three statistically significant variables: both indices, sex, and diabetes mellitus. Both traditional and new SI yielded individual odds ratios of 0.906 with estimated areas under the curve of 0.847 for traditional SI and 0.833 for new SI. Conclusions: This study confirmed that both traditional and new SI are associated with osteoporosis in patients with CKD. Therefore, clinicians can raise the suspicion of osteoporosis based on traditional and new SI in patients with CKD, even when DXA results are unavailable.

Ha C, et al. Clin Orthop Surg. 2025 Feb;17(1):174-180. https://doi.org/10.4055/cios24188

In 1979, Linburg and Comstock reported a lesion that interfered with the independent flexion of the fingers due to an abnormal connection between the flexor pollicis longus and the tendon of the flexor digitorum profundus to the index finger. This entity can cause discomfort in daily life when functionally delicate finger use is required; therefore, surgical treatment is sometimes recommended depending on the symptoms. The authors performed surgical treatment for a patient who visited our outpatient clinic seeking functional improvement for congenital symptoms of simultaneous thumb and index finger flexion and obtained satisfactory results. Reports of surgical treatment for Linburg-Comstock syndrome are rare in Korea, so the authors report this experience, along with a review of the literature.