Can the Sterilization Protocol Be Improved to Enhance the Healing of Allograft Tendons? An In Vivo Study in Rabbit Tendons.

BACKGROUND: Peracetic acid and irradiation are common sterilization methods for allograft tendons; however, under some conditions, both methods adversely affect the fiber arrangement and ultimate load of the tendon. An in vitro study showed that low-dose peracetic acid combined with irradiation may be less detrimental to allograft tendon structure and properties, possibly because the breakdown of peracetic acid can lead to an enlargement of the interstitial spaces and an increase in porosity. QUESTIONS/PURPOSES: Using a rabbit Achilles tendon model, we asked: What is the effect of peracetic acid-ethanol combined irradiation on (1) the histopathology and fiber diameter of the allograft tendon, (2) tensile creep and load-to-failure biomechanical properties of allograft tendons, and (3) healing of the treated tendon in vivo compared with fresh-frozen allograft and peracetic acid-ethanol sterilization at 4 and 8 weeks? METHODS: The Achilles tendons used in this study were sourced from euthanized 10-week-old male New Zealand White rabbits previously used for ophthalmic experiments. All allografts were divided into three groups: fresh-frozen group (control group, n = 20), peracetic acid-ethanol sterilization group (n =20), and peracetic acid-ethanol combined irradiation group (n = 20). The sterilization protocols were performed per a predetermined plan. In the peracetic acid-ethanol sterilization group, the tendon tissues were covered with the peracetic acid-ethanol sterilization solution (1% peracetic acid for 30 minutes). In the peracetic acid-ethanol combined irradiation group, the tendon tissues were covered with the peracetic acid-ethanol sterilization solution (0.2% peracetic acid for 30 minutes) and were subjected to 15 kGy gamma irradiation. Thirty 10-week-old male New Zealand White rabbits received bilateral Achilles tendon allografts surgically. Tendon samples from each group were harvested at 4 weeks (n = 30) and 8 weeks (n = 30) postoperatively. For each timepoint, eight tissues were used for histologic staining and electron microscopy, 15 tissues were used for biomechanical testing, and seven tissues were used for hydroxyproline assay and quantitative polymerase chain reaction. Histopathology was determined qualitatively by hematoxylin and eosin and Masson staining, while fiber diameter was measured quantitatively by transmission electron microscopy. Biomechanical properties were measured using cyclic loading tests and load-to-failure tests. The healing outcome was quantitatively judged through healing-related genes and proteins. RESULTS: At 4 weeks and 8 weeks postoperatively, the peracetic acid-ethanol combined irradiation group visually demonstrated the best continuity and minimal peripheral adhesions. Histologic staining showed that tendon fibers in the peracetic acid-ethanol combined irradiation group maintained consistent alignment without notable disruptions or discontinuities, and there was a qualitatively observed increase in the number of infiltrating cells compared with the control group at the 4-week timepoint (444 ± 49 /mm 2 versus 256 ± 43 /mm 2 , mean difference 188 /mm 2 [95% confidence interval 96 to 281]; p < 0.001). At 8 weeks postoperatively, the tendon fiber diameter in the peracetic acid-ethanol combined irradiation groups was similar to that of the control group (0.23 ± 0.04 µm versus 0.21 ± 0.03 µm, mean difference 0.02 µm [95% CI -0.04 to 0.08]; p = 0.56). At 8 weeks postoperatively, the peracetic acid-ethanol combined irradiation group exhibited better properties in terms of both ultimate load (129 ± 15 N versus 89 ± 20 N, mean difference 40 N [95% CI 7 to 73]; p = 0.02) and energy absorption density (17 ± 6 kJ/m 2 versus 8 ± 4 kJ/m 2 , mean difference 8 kJ/m 2 [95% CI 0.7 to 16]; p = 0.004) compared with the control group. Gene expression analysis revealed higher expression levels of COL1A1 (2.1 ± 0.8 versus 1.0 ± 0, mean difference 1.1 [95% CI 0.1 to 2.1]; p = 0.003) and MMP13 (2.0 ± 0.8 versus 1.0 ± 0, mean difference 1.0 [95% CI 0.4 to 1.6]; p = 0.03) in the peracetic acid-ethanol combined irradiation group than in the control group. There was a higher amount of collagen Type I in tendons treated with peracetic acid-ethanol combined irradiation than in the control group (0.36 ± 0.03 versus 0.31 ± 0.04, mean difference 0.05 [95% CI 0.01 to 0.09]; p = 0.02). CONCLUSION: Treatment with peracetic acid-ethanol combined irradiation did not have any discernible adverse effect on the histology, fiber diameter, enzymatic resistance, collagen content, or biomechanical strength of the allograft tendons compared with the control group. Peracetic acid-ethanol combined irradiation treatment had a positive impact on remodeling of the extracellular matrix and realignment of collagen fibers. CLINICAL RELEVANCE: This sterilization method could be helpful to expand the scope and frequency with which allogeneic materials are applied. The long-term healing effect and strength of allograft tendons must be tested before clinical use, and it is necessary to conduct comparative studies on autografts and synthetic materials that are currently widely used clinically.

U-shaped kirschner wire transfixation: effective treatment for Skier's thumb.

BACKGROUND: Skier's thumb is a type of injury to the ulnar collateral ligament of the metacarpophalangeal joint of the thumb, which can result in bone fragmentation and joint instability. OBJECTIVE: The objective of this study was to compare the traditional Kirschner wire fixation method with the U-shaped Kirschner wire method for treating small bone fragments with displacement, rotation, or instability in skier's fractures. METHOD: A retrospective study was conducted on 30 patients with skier's thumb who were treated at Tianjin Hospital from January 2019 to December 2021. Patients were divided into two groups: Group A received traditional Kirschner wire fixation, while Group B received U-shaped Kirschner wire fixation. Functional assessments and complications during the perioperative period were evaluated. RESULTS: Both surgical methods significantly reduced postoperative pain and increased joint range of motion. Group B had a lower incidence of pain during follow-up and showed significant functional improvement in Tip-pinch and Grip tests compared to Group A. U-shaped Kirschner wire fixation significantly reduced complications during the perioperative period. CONCLUSION: The U-shaped Kirschner wire internal fixation is a safe and effective treatment for the thumb proximal phalanx base ulnar side avulsion fracture.

Microwave-assisted intralesional curettage combined with other adjuvant methods for treatment of Campanacci III giant cell tumor of bone in distal radius: a multicenter clinical study.

Objective: To compare the clinical outcomes of microwave-assisted intralesional curettage(MAIC) with those of en bloc resection and autogenous fibular reconstruction (EBR-AFR) for treating grade III giant cell tumor of the bone (GCTB) of the distal radius and to elucidate the indications for wrist preservation surgery. Materials and methods: In this retrospective study, 19 patients with grade III GCTB of the distal radius who underwent surgery at three medical institutions were included and categorized based on their surgical pattern. Seven patients underwent MAIC and internal fixation with bone cement (MAIC group) and 12 underwent EBR-AFR (EBR-AFR group). To evaluate the function of the affected limb postoperatively, wrist range of motion, grip strength, Musculoskeletal Tumor Society (MSTS) scores were recorded. Results: The follow-up time of the MAIC group was 73.57 ± 28.61 (36-116) months, with no recurrence or lung metastasis. In contrast, the follow-up time of the EBR-AFR group was 55.67 ± 28.74 (36-132) months, with 1 case of local recurrence (8.3%, 1/12) and 1 case of lung metastasis (8.3%, 1/12). The wrist flexion, extension, supination, pronation, grip strength were better in the MAIC group than in the EBR-AFR group. Although there was no statistically significant difference in the MSTS score between the two groups, it is noteworthy that the MAIC group exhibited significantly superior emotional acceptance and hand positioning compared to the EBR-AFR group(p < 0.05). Conclusion: The functional outcomes of the MAIC group are better. The treatment strategy for grade III GCTB of the distal radius should be determined based on the specific preoperative imaging findings. Nevertheless, MAIC can be the preferred surgical approach for most patients with grade III GCTB of the distal radius, particularly for young patients.

Radiomics in Diagnosis, Grading, and Treatment Response Assessment of Soft Tissue Sarcomas: A Systematic Review and Meta-analysis.

RATIONALE AND OBJECTIVES: To evaluate radiomics in soft tissue sarcomas (STSs) for diagnostic accuracy, grading, and treatment response assessment, with a focus on clinical relevance. METHODS: In this diagnostic accuracy study, radiomics was applied using multiple MRI sequences and AI classifiers, with histopathological diagnosis as the reference standard. Statistical analysis involved meta-analysis, random-effects model, and Deeks' funnel plot asymmetry test. RESULTS: Among 579 unique titles and abstracts, 24 articles were included in the systematic review, with 21 used for meta-analysis. Radiomics demonstrated a pooled sensitivity of 84% (95% CI: 80-87) and specificity of 63% (95% CI: 56-70), AUC of 0.93 for diagnosis, sensitivity of 84% (95% CI: 82-87) and specificity of 73% (95% CI: 68-77), AUC of 0.91 for grading, and sensitivity of 83% (95% CI: 67-94) and specificity of 67% (95% CI: 59-74), AUC of 0.87 for treatment response assessment. CONCLUSION: Radiomics exhibits potential for accurate diagnosis, grading, and treatment response assessment in STSs, emphasizing the need for standardization and prospective trials. CLINICAL RELEVANCE STATEMENT: Radiomics offers precise tools for STS diagnosis, grading, and treatment response assessment, with implications for optimizing patient care and treatment strategies in this complex malignancy.

Limitations and modifications in the clinical application of calcium sulfate.

Calcium sulfate and calcium sulfate-based biomaterials have been widely used in non-load-bearing bone defects for hundreds of years due to their superior biocompatibility, biodegradability, and non-toxicity. However, lower compressive strength and rapid degradation rate are the main limitations in clinical applications. Excessive absorption causes a sharp increase in sulfate ion and calcium ion concentrations around the bone defect site, resulting in delayed wound healing and hypercalcemia. In addition, the space between calcium sulfate and the host bone, resulting from excessively rapid absorption, has adverse effects on bone healing or fusion techniques. This issue has been recognized and addressed. The lack of sufficient mechanical strength makes it challenging to use calcium sulfate and calcium sulfate-based biomaterials in load-bearing areas. To overcome these defects, the introduction of various inorganic additives, such as calcium carbonate, calcium phosphate, and calcium silicate, into calcium sulfate is an effective measure. Inorganic materials with different physical and chemical properties can greatly improve the properties of calcium sulfate composites. For example, the hydrolysis products of calcium carbonate are alkaline substances that can buffer the acidic environment caused by the degradation of calcium sulfate; calcium phosphate has poor degradation, which can effectively avoid the excessive absorption of calcium sulfate; and calcium silicate can promote the compressive strength and stimulate new bone formation. The purpose of this review is to review the poor properties of calcium sulfate and its complications in clinical application and to explore the effect of various inorganic additives on the physicochemical properties and biological properties of calcium sulfate.

Modular intercalary prosthetic reconstruction for malignant and metastatic tumours of the proximal femur.

To illustrate the surgical technique and explore clinical outcomes of the reconstruction for the malignant and metastatic bone tumour of proximal femur with metallic modular intercalary prosthesis. Sixteen patients who underwent modular intercalary prosthetic reconstruction after tumour resection were included from April 2012 and October 2020. Prosthesis and screws parameters, resected bone length and residual bone length, clinical outcomes and survivorship were analyzed. All patients were followed up for an average of 19 months (range 1-74). In our series, 12 patients died of the progression of the primary disease at the final follow-up. The cumulative survivorship since the treatment of proximal femoral metastasis was 78.6% (11 patients) at 6 months and 38.5% (5 patients) at 1 year. The mean MSTS score was 22.25 ± 4.55 among all patients. There were no cases of loosening or breakage of the prostheses, plates or screws, despite the various measurements of prostheses and residual bones. Modular intercalary prosthetic reconstruction was an effective method for malignant tumour of the proximal femur, including the advantages of providing early pain relief, quickly restoring postoperative function, required a short operation time, and preserving the adjacent joints.

Targeting the chromatin structural changes of antitumor immunity.

Epigenomic imbalance drives abnormal transcriptional processes, promoting the onset and progression of cancer. Although defective gene regulation generally affects carcinogenesis and tumor suppression networks, tumor immunogenicity and immune cells involved in antitumor responses may also be affected by epigenomic changes, which may have significant implications for the development and application of epigenetic therapy, cancer immunotherapy, and their combinations. Herein, we focus on the impact of epigenetic regulation on tumor immune cell function and the role of key abnormal epigenetic processes, DNA methylation, histone post-translational modification, and chromatin structure in tumor immunogenicity, and introduce these epigenetic research methods. We emphasize the value of small-molecule inhibitors of epigenetic modulators in enhancing antitumor immune responses and discuss the challenges of developing treatment plans that combine epigenetic therapy and immunotherapy through the complex interaction between cancer epigenetics and cancer immunology.