Advancing skeletal health and disease research with single-cell RNA sequencing.

Orthopedic conditions have emerged as global health concerns, impacting approximately 1.7 billion individuals worldwide. However, the limited understanding of the underlying pathological processes at the cellular and molecular level has hindered the development of comprehensive treatment options for these disorders. The advent of single-cell RNA sequencing (scRNA-seq) technology has revolutionized biomedical research by enabling detailed examination of cellular and molecular diversity. Nevertheless, investigating mechanisms at the single-cell level in highly mineralized skeletal tissue poses technical challenges. In this comprehensive review, we present a streamlined approach to obtaining high-quality single cells from skeletal tissue and provide an overview of existing scRNA-seq technologies employed in skeletal studies along with practical bioinformatic analysis pipelines. By utilizing these methodologies, crucial insights into the developmental dynamics, maintenance of homeostasis, and pathological processes involved in spine, joint, bone, muscle, and tendon disorders have been uncovered. Specifically focusing on the joint diseases of degenerative disc disease, osteoarthritis, and rheumatoid arthritis using scRNA-seq has provided novel insights and a more nuanced comprehension. These findings have paved the way for discovering novel therapeutic targets that offer potential benefits to patients suffering from diverse skeletal disorders.

Fate of the intervertebral disc and analysis of its risk factors following high-energy traumatic thoracic and lumbar fractures: MRI results of minimum five years after injury.

OBJECTIVE: Disc degenerative disease is regarded as the primary cause of low back pain. The purpose of this study was to clarify the fate of Intervertebral disc (IVD) following the traumatic event through long-term follow-up and to identify the risk factors for irrevocable degeneration. METHODS: 78 non-operative patients who had traumatic fracture of the thoracic or lumbar at minimum 5 years before were enrolled. Disc degeneration was assessed by modified Pfirrmann grading system. The Acceleration of disc degeneration (ADD) was defined as the difference of grade between IVD adjacent to fractured vertebra and their neighbors with increasing grade from 0 to 7. A novel classification of Endplate injury (EPI) with increasing severity from type I to III was proposed based on the injured morphology. The long-term fate of IVD adjacent to fractured vertebra and risk factors for ADD were analyzed. RESULTS: The mean time of last follow-up was 15.4 ± 10.8 years (range 5-49 years) after injury. 138 (68.66%) IVDs were graded 0 of ADD, 44 (21.89%) were 1-3 and 19 (9.45%) were 4-7. Multivariate binary logistic regression analyses showed that injured posterior ligamentous complex (PLC) and EPI type III were independent risk factors for ADD. CONCLUSIONS: Injured PLC and EPI type III were independent risk factors for ADD in patients with traumatic thoracic or lumbar fracture. For such patients without risk factors for ADD, the non-intervertebral fusion should be given a priority if surgery is necessary.

Comparison of unilateral and bilateral polymethylmethacrylate-augmented cannulated pedicle screw fixation for the management of lumbar spondylolisthesis with osteoporosis.

BACKGROUND: Cannulated pedicle screw (CPS) augmented by polymethylmethacrylate (PMMA) can achieve satisfactory clinical efficacy in the treatment of lumbar spondylolisthesis with osteoporosis. However, accurate application of CPSs will help to avoid the difficulty of screw revision and reduce the incidence of PMMA-related complications. This study aimed to investigate the mid-term efficacy of CPS compared to unilateral and bilateral applications in this common lumbar degenerative disease. METHODS: May 2011 and May 2018, 50 patients with lumbar spondylolisthesis with osteoporosis who underwent posterior fixation and fusion using traditional pedicle screws or CPSs were included in the study. Patients were divided into two groups based on the application: the unilateral PMMA-augmented CPS group (UC, n = 29) and the bilateral PMMA-augmented CPS group (BC, n = 21). Operation time, blood loss, average hospitalization time, PMMA leakage, and other complications were recorded. The visual analog scale (VAS) and Oswestry disability index (ODI) scores were used to evaluate symptom recovery. Radiographic results were compared for intervertebral fusion and screw loosening. RESULTS: There were no significant differences in the baseline data of the two groups. The VAS and ODI scores improved significantly after surgery (P < 0.05), with no significant differences between the groups (P > 0.05). The operation time and blood loss in the UC group were significantly lower than those in the BC group (P < 0.05). However, the loss of intervertebral disk height and Taillard index did not differ significantly between the groups. The rates of PMMA leakage in the UC and BC groups were 7.0% and 11.9%, respectively (P < 0.05). Bony fusion was achieved in all groups without screw loosening at the last follow-up. Only one patient experienced superficial infection in both groups, while cerebrospinal fluid leakage was observed in two patients in the BC group. CONCLUSIONS: Unilateral application of PMMA-augmented CPS may provide adequate clinical safety and effectiveness in the surgical treatment of lumbar spondylolisthesis with osteoporosis.