Woo Kim

Comparison of the Cellular Composition and Cytokine-Release Kinetics of Various Platelet-Rich Plasma Preparations.

Background: Variations in formulations used to prepare platelet-rich plasmas (PRPs) result in differences in the cellular composition and biomolecular characteristics. Purpose: To evaluate the cellular composition and the cytokine-release kinetics of PRP according to differences in the preparation protocols. Study Design: Controlled laboratory study. Methods: Five preparation procedures were performed for 14 healthy subjects, including 2 manual procedures (single-spin [SS] at 900g for 5 minutes; double-spin [DS] at 900g for 5 minutes and then 1500g for 15 minutes) and 3 methods with commercial kits (Arthrex ACP, Biomet GPS, and Prodizen Prosys). After evaluation of cellular composition, each preparation was divided into 4 aliquots and incubated for 1 hour, 24 hours, 72 hours, and 7 days for the assessment of cytokine release over time. The cytokine-release kinetics were evaluated by assessing platelet-derived growth factor (PDGF), transforming growth factor (TGF), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), interleukin-1 (IL-1), and matrix metalloproteinase–9 (MMP-9) concentrations of each aliquot with bead-based sandwich immunoassay. Results: The DS PRP had a higher concentration of platelets and leukocytes than did the SS PRP. Every PRP preparation exhibited an increase in PDGF, TGF, VEGF, and FGF release when compared with whole blood samples. The FGF and TGF release occurred quickly and decreased over time, while the PDGF and VEGF release was constant and sustained over 7 days. The PDGF and VEGF concentrations were higher in the DS PRP than in the SS PRP, whereas the TGF and FGF concentrations were higher in the SS PRP than in the DS PRP. Biomet GPS had the highest VEGF and MMP-9 concentrations but the lowest TGF concentration. Arthrex ACP had the highest FGF concentration but the lowest PDGF concentration. Prodizen Prosys had the highest IL-1 concentration and higher PDGF concentration than Arthrex ACP. Conclusion: The DS method generally led to a higher concentration of platelet relative to the SS method. However, the cytokine content was not necessarily proportional to the cellular composition of the PRPs, as the greater content could be different between the SS or DS method depending on the type of cytokine. Clinical Relevance: Physicians should select proper PRP preparations after considering their biomolecular characteristics and patient indications.

Measurement Methods for Humeral Retroversion Using Two-Dimensional Computed Tomography Scans: Which Is Most Concordant with the Standard Method?

Background Humeral retroversion is variable among individuals, and there are several measurement methods. This study was conducted to compare the concordance and reliability between the standard method and 5 other measurement methods on two-dimensional (2D) computed tomography (CT) scans. Methods CT scans from 21 patients who underwent shoulder arthroplasty (19 women and 2 men; mean age, 70.1 years [range, 42 to 81 years]) were analyzed. The elbow transepicondylar axis was used as a distal reference. Proximal reference points included the central humeral head axis (standard method), the axis of the humeral center to 9 mm posterior to the posterior margin of the bicipital groove (method 1), the central axis of the bicipital groove –30° (method 2), the base axis of the triangular shaped metaphysis +2.5° (method 3), the distal humeral head central axis +2.4° (method 4), and contralateral humeral head retroversion (method 5). Measurements were conducted independently by two orthopedic surgeons. Results The mean humeral retroversion was 31.42° ± 12.10° using the standard method, and 29.70° ± 11.66° (method 1), 30.64° ± 11.24° (method 2), 30.41° ± 11.17° (method 3), 32.14° ± 11.70° (method 4), and 34.15° ± 11.47° (method 5) for the other methods. Interobserver reliability and intraobserver reliability exceeded 0.75 for all methods. On the test to evaluate the equality of the standard method to the other methods, the intraclass correlation coefficients (ICCs) of method 2 and method 4 were different from the ICC of the standard method in surgeon A (p < 0.05), and the ICCs of method 2 and method 3 were different form the ICC of the standard method in surgeon B (p < 0.05). Conclusions Humeral version measurement using the posterior margin of the bicipital groove (method 1) would be most concordant with the standard method even though all 5 methods showed excellent agreements.

Intraarticular epidermal cyst of knee

An epidermal cyst is a common benign lesion that generally exists in subcutaneous tissue. Prevalent sites of the lesion are the trunk, neck, face, hand, and foot [1]. It generally develops from a trauma leading to the implantation of an epithelial element. It can also congenitally develop, probably through the inclusion of epidermal elements during neural tube closure in embryogenesis. It rarely develops after an orthopedic procedure, and there have been only a few reports of such a lesion around the knee [2–4]; the majority of them developed in subcutaneous tissue. The authors know of only one report on an epidermal cyst in a joint cavity [3]. In this work, we report an epidermal cyst that developed in a knee joint cavity after an arthroscopic procedure.

Outcomes of Rotator Cuff Repair in Patients with Comorbid Disability in the Extremities

Background Rehabilitation and overuse of the shoulder after rotator cuff repair are a concern in patients with comorbid disability in other extremities. Improvement of outcomes can be hampered in this situation. This study was to describe the clinical outcomes of rotator cuff repair in patients with comorbid disability in other extremities. Methods In two tertiary institutions, 16 patients with comorbid disability (9 men and 7 women; mean age of 57.1 years [range, 45 to 71 years]; 14 dominant arms; mean follow-up of 18 months [range, 12 to 38 months]) underwent rotator cuff repair. There were 5 massive tears, 1 large tear, 9 medium tears, and 1 small tear. Open repair was performed in 3 patients and arthroscopic repair in 13. The most common comorbid condition was paralysis (n = 7). Eight patients walked with crutches preoperatively. Anatomical outcome was investigated in 12 patients using either magnetic resonance imaging or ultrasonography at least 6 months postoperatively. Results Range of motion, visual analogue scale for pain and satisfaction, and all functional scores improved significantly. Healing failure occurred in 4 patients (2 large-to-massive and 2 medium size tears), but none required revision surgery. All 4 retears involved the dominant side, and 3 patients were crutch users. Conclusions The current data suggested favorable outcome of rotator cuff repair in patients with comorbid disability. Careful surgical planning and rehabilitation is particularly important for crutch users and in the case of dominant arm involvement in disabled patients.