Medial meniscus posterior root tears (MMRTs), defined as tears or avulsions that occur within 1 cm of the tibial attachment of the medial meniscus posterior root, lead to biomechanically detrimental knee conditions by creating a functionally meniscal-deficient status. Given their biomechanical significance, MMRTs have recently been gaining increasing interest. Accordingly, numerous studies have been conducted on the anatomy, biomechanics, clinical features, diagnosis, and treatment of MMRTs, and extensive knowledge has been accumulated. Although a consensus has not yet been reached on several issues, such as surgical indications, surgical techniques, and rehabilitation protocols, this article aimed to comprehensively review the current knowledge on MMRTs and to introduce the author’s treatment strategies.

Background: Osteoarthritis (OA) poses a significant global burden, with conventional treatments like corticosteroid and hyaluronic acid (HA) injections commonly used. Emerging injectable biologics, including bone marrow aspirate concentrate (BMAC), show promise in OA management. Purpose: To investigate the clinical efficacy of BMAC injection compared with other injection treatments for knee OA. Study Design: Systematic review; Level of evidence, 1. Methods: A systematic review was conducted using PubMed, Embase, Cochrane Library, and Google Scholar to identify randomized controlled trials with Level 1 evidence that compared the clinical efficacy of BMAC with other injections. The visual analog scale for pain and the Pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) were used as clinical scores representing pain. For functional assessment, the Western Ontario and McMaster Universities Osteoarthritis Index and the International Knee Documentation Committee subjective form were used. For studies comparing BMAC with HA, each clinical score was standardized to pain and function scales based on the minimal clinically important difference (MCID). Results: Eight studies, consisting of a total of 937 patients, were included. Patients treated with BMAC showed a significant improvement in clinical scores compared with baseline, starting at 1 month postinjection. For pain scores at 6-month ( P = .033) and 12-month follow-up ( P = .011), BMAC demonstrated favorable results over HA, with a statistically significant difference. However, these differences did not exceed the MCID. When BMAC was compared with other injections, no significant differences were observed in the degree of clinical score improvement. No serious adverse events or events significantly associated with BMAC compared with other treatments were reported. Conclusion: BMAC injections demonstrated effectiveness in providing pain relief and functional improvement for patients with knee OA. When BMAC was compared with other intra-articular injection options, distinct differences surpassing the MCID were not evident. Further research is deemed necessary to investigate the role of BMAC in the treatment of knee OA.

Background: Osteoarthritis (OA) is a multifactorial disease involving inflammatory processes. Platelets play important roles in both hemostasis and the inflammatory response; however, the relationship between platelet count and OA is unclear. Our aim was to evaluate the association between platelet count and knee and hip OA in Korean women. Methods: In this cross-sectional designed study, we included a total of 6011 women aged ⩾50 years from the 2010–2013 Korea National Health and Nutrition Examination Survey. Knee and hip OA were defined as Kellgren–Lawrence grade ⩾2 and presence of knee or hip pain, respectively. Platelet counts were divided into quartiles as follows: Q1, 150–212 (10³/µl); Q2, 213–246 (10³/µl); Q3, 247–283 (10³/µl); and Q4, 284–450 (10³/µl). Multiple logistic-regression analysis was conducted to calculate odds ratios and 95% confidence intervals. Receiver operating characteristic analysis was performed to determine the optimal platelet count cut-off with which to discriminate participants with knee and/hip OA versus those without OA. Results: Of the 6011 participants, 1141 (18.1%) had knee or hip OA. The mean age of participants without OA was 60.6 years, and that of participants with OA was 68.0 years. Compared with the lowest quartile, odds ratios (95% confidence intervals) for OA were 1.08 (0.84–1.39) for Q2, 0.94 (0.73–1.23) for Q3, and 1.35 (1.08–1.69) for Q4 after adjusting for confounders. The prevalence of OA was significantly higher with platelet counts ⩾288 × 10³/µl, compared with platelet counts <288 × 10³/µl. Conclusion: High platelet counts within the normal range are significantly associated with knee and hip OA.

The interrelation and clinical utility of the parameters for superior migration of the humeral head, such as the acromiohumeral interval (AHI), inferior glenohumeral distance (IGHD), and upward migration index (UMI), in the management of massive rotator cuff tears are not clear. The objectives of this study were to identify the relation between AHI, IGHD, and UMI when measured with radiography and MRI and to determine whether superior migration can predict the irreparability of massive rotator cuff tears. We retrospectively reviewed the files of 64 consecutive patients who underwent arthroscopic partial or complete repair for massive rotator cuff tears at our institution between August 2015 and August 2018. We recorded both radiography and MRI measurements of AHI, IGHD, and UMI, and further the tangent sign, fatty infiltration of the rotator cuff muscles, and the Patte grade. We performed correlation assessments and multiple logistic regression analysis to identify potential predictors of the reparability of massive rotator cuff tears. Thirty-five patients had partially reparable and 29 had completely reparable tears. Parameters measured with either radiography or MRI were highly correlated with each other. The radiographic measurements showed a moderate or low correlation with the MRI measurements. All parameters of superior migration of the humeral head on radiography and MRI, the tangent sign, fatty infiltration of the infraspinatus muscle, and the Patte grade showed significant differences between patients with partially and completely repaired tears. Among these, the independent predictors for irreparability was Patte grade = 3. The AHI, IGHD, and UMI were highly correlated when measured with either radiography or MRI, but not when comparing their radiographic with their MRI values. Furthermore, they were not independent indicators of reparability in massive rotator cuff tears.