Graft shrinkage or radial extrusion is a reported complication after meniscus allograft transplantation (MAT). Whether shrinkage or extrusion progress after surgery and whether they are associated with the clinical outcome of MAT remain debatable. In this study, graft shrinkage and extrusion were measured in the coronal and sagittal planes using serial postoperative magnetic resonance imaging (MRI). The purpose of this study was to evaluate if graft shrinkage or extrusion is correlated to the clinical outcome of MAT. MRIs acquired at 3 and 12 months postoperatively in 30 patients (21 men and 9 women) who underwent MAT (6 medial and 24 lateral menisci) from 2010 to 2016 were analyzed. Two orthopedic surgeons and two musculoskeletal specialized radiologists each performed the MRI measurements. Allograft shrinkage was measured by the width and thickness of the graft at the coronal and sagittal planes. To determine the graft extrusion, distances between the proximal tibia cartilage margin and the extruded graft margin were measured in both coronal (either lateral or medial) and sagittal (both anterior and posterior) plane and relative percentage of extrusion (RPE) were calculated. Subjective International Knee Documentation Committee (IKDC) scores at 12 months were evaluated as a clinical outcome measurement, and correlations between shrinkage or extrusion of allograft and IKDC score were analyzed. In the coronal plane, radial RPE averaged 43.6% at postoperative 3 months, but there was no significant progression of extrusion at 12 months (average 42.0%) (P = 0.728). In the sagittal plane, there were no significant progressions of anterior and posterior RPE (P = 0.487 and 0.166, respectively) between postoperative 3 and 12 months. Shrinkage was calculated by multiplying the width and height of the three sections and summing these values. There was no significant progression of shrinkage between postoperative 3 and 12 months (P = 0.150). RPE in the radial (R = 0.147, P = 0.525), anterior (R = 0.249, P = 0.264), and posterior (R = 0.230, P = 0.315) directions and shrinkage (R = 0.176, P = 0.435) were not correlated to IKDC score at postoperative 12 months. In the coronal and sagittal planes, extrusion and shrinkage did not progress from 3 months to 1 year. Extrusion and shrinkage had no correlation with early clinical outcomes. This finding suggests that graft extrusion or shrinkage may be not a great concern especially in early postoperative period of MAT, and multiple, serial MRI may be not necessary.

Studies on the results of arthroscopic repair of massive rotator cuff tears have reported widely varied prognoses. Among other factors, the sizable discrepancy can be attributable to the fact that the current definition of massive rotator cuff tears covers an extensive area of tendons. Functional and radiological results according to subgroups would show significant inter-subgroup differences preoperatively and postoperatively. Cohort study; Level of evidence, 2. A total of 104 patients who required arthroscopic repair for massive rotator cuff tears were prospectively evaluated. The patients were allocated into 3 groups according to tendon involvement as diagnosed by preoperative magnetic resonance imaging: group 1 (anterosuperior type involving the subscapularis and supraspinatus), group 2 (posterosuperior type involving the infraspinatus and supraspinatus), and group 3 (anteroposterior type involving the subscapularis, supraspinatus, and infraspinatus). We compared functional results (at 2 years postoperatively) and radiological findings (at 1 year postoperatively) for each group. There were 34 patients in group 1, 54 in group 2, and 16 in group 3. In all 3 groups, functional results significantly improved after surgery. There were no statistically significant intergroup differences in functional results among the 3 groups. On the radiological evaluations, each group (groups 1, 2, and 3) showed a significantly different result in the preoperative acromiohumeral distance (AHD) (7.19, 5.44, and 5.22 mm, respectively), tear size (38.8, 39.3, and 46.4 mm, respectively), extent of retraction (33.9, 40.0, and 41.4 mm, respectively), postoperative AHD (8.92, 7.37, and 6.71 mm, respectively), and retear rate (23.5%, 51.9%, and 56.2%, respectively) (P < .001 for all). Massive rotator cuff tears can be divided into 3 types: anterosuperior (group 1), posterosuperior (group 2), and anteroposterior (group 3). Each group has distinctive characteristics and shows different results in the preoperative AHD, tear size, extent of retraction, postoperative AHD, and retear rate, which provide a reasonable basis for categorization. So far, massive rotator cuff tears have only been broadly defined, consequently being understood as a single category by many. However, to clearly understand and evaluate this injury, we suggest identifying differences within the category through proper subclassification.

Purpose: The study aim was to evaluate gap healing after medial open-wedge high tibial osteotomy (MOWHTO) using novel injectable beta-tricalcium phosphate (β-TCP) as gap filler. We also aimed to evaluate radiographic and clinical outcome of MOWHTO using injectable β-TCP. Methods: Consecutive 28 patients underwent MOWHTO using anatomical locking plate fixation, and β-TCP was injected as gap filler. Serial radiographs and computed tomography were taken at postoperative 3 and 12 months, and gap healing was assessed. Lower extremity alignment was measured on radiographs, and clinical outcome was evaluated by determining International Knee Documentation Committee, Western Ontario and McMaster Universities Arthritis Index, and visual analogue scales for pain scores. Results: Progress of bone union was found on plain radiographs, and the mean ratio (β-TCP/host bone) of computed tomography attenuation values significantly changed from postoperative 3 months to 12 months, which indicates maturation of β-TCP. The average mechanical femoro-tibial angle changed from 4.1° varus (preoperative) to 4.8° valgus (3 months) and maintained until 12 months (4.3° valgus). All clinical outcome scores were significantly improved and no significant complication occurred. Conclusion: Using injectable β-TCP as gap filler for MOWHTO resulted in satisfactory gap healing without complication. Radiographic and clinical results were satisfactory. The injectable β-TCP can be a safe and effective option for gap filling after MOWHTO.

A rotator cuff is a muscle and tendon surrounding the shoulder joint, and a rotator cuff tear can be caused by overuse or injury, which leads to great pain in affected individuals. However, rotator cuff tear is a multifactorial process whose underlying mechanism is still unclear. Many previous studies have suggested an important role of genetic predisposition, such as single-nucleotide polymorphisms (SNPs), in explaining the genesis of tendinopathy. This study aimed to identify specific genes or genetic variants associated with rotator cuff tears by performing a genome-wide association study (GWAS) using an independent case of rotator cuff tears. GWAS was performed using data from CHA Bundang Medical Center with 20 cases of rotator cuff tears, and 20 cases of healthy controls genotyped on the Illumina HiSeq 2500. Tests of association were performed using the Burrows–Wheeler Aligner (BWA) software at 284,246 SNPs. Data were filtered based on sequence ontology, minor allele frequency, and Hardy–Weinberg equilibrium values, and SNPs were considered significant if the p-value was <0.05. The tests of association revealed more than 20 significantly associated SNPs. SNPs showing the highest significance occurred in candidate genes, including LAIR2 (rs2287828, OR 9.116, p-value 5.49 × 10⁻⁴) on chromosome 19 and CRIPAK (rs9328733, OR 6, p-value 1.11 × 10⁻³) and REST (rs2228991, OR 8.222, p-value 1.20 × 10⁻³) on chromosome 4. This study attempted to identify genetic variants influencing rotator cuff tears through a genome-wide association study using a dense set of SNPs. More than 20 SNPs were significantly associated with rotator cuff tears. The major limitation of this study is that it was conducted on a small study group and requires further validation. Nevertheless, the identification of potential genetic variants related to rotator cuff injury would aid in the early detection of individuals at risk for the development of tendinopathy and will provide insight into future gene therapies.