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Background: Accurate allograft matching is deemed critical for meniscal transplantation; thus, precise measurements are essential to correctly calculate meniscal size. Several methods for meniscal sizing have been described, but there remains a discussion on which is the most accurate for the lateral meniscus. Purpose: To compare the accuracy of radiographic, anthropometric, and magnetic resonance imaging (MRI) methods of determining width and length of the lateral meniscus with actual dimensions after anatomic dissection. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen human cadaveric knees without any evidence of meniscal or ligamentous injury were primarily imaged using radiography and MRI and subsequently underwent dissection to assess the anatomic size of each meniscus. Four methods were used to predict the size of the lateral menisci: anthropometric, radiographic (Pollard and Yoon), and MRI. Absolute differences in length and width between actual and predicted sizes were determined. Results: The anatomic lateral meniscal width and length were 33.01 ± 4.25 mm (mean ± SD; range, 24.84-40.18 mm) and 31.41 ± 5.06 mm (range, 25.2-40.05 mm), respectively. Regarding width, the anthropometric method demonstrated an absolute difference from anatomic measurement significantly greater when compared with the Pollard technique and MRI (P =.002). Regarding length, the Pollard method presented an absolute difference significantly greater than all other techniques (P =.003). In terms of the ability to measure width and length, MRI accurately predicted meniscal size within 10% of the anatomic size in 65% of measurements, the Yoon method in 54%, and the Pollard method in 20% (P =.01). Radiographs tended to overestimate the true size of the lateral meniscus, while the anthropometric technique overestimated width in all specimens. Conclusion: This study demonstrated that MRI and the Yoon radiographic method are comparable in terms of accuracy for graft sizing before lateral meniscal transplantation. While MRI is useful, a contralateral MRI is required, which makes the Yoon radiographic method recommended given the ease and cost advantage. The original Pollard technique and the anthropometric method are not recommended. Clinical Relevance: Over- and undersizing of meniscal transplants has been implicated in graft failure. Therefore, increasing the reliability of preoperative meniscal measurements is deemed important for the success of meniscal allograft transplantation. [ABSTRACT FROM AUTHOR]

Background: Assays to quantitate the quality of autologous chondrocyte implants have recently become available. However, the correlation of the assay score with radiological and clinical outcomes has not been established. Purpose/Hypothesis: The purpose was to assess the influence of cell identity (chondrocyte/synoviocyte gene expression ratio) and viability on patient-reported outcome measures, graft survival, and repair tissue quality. It was hypothesized that greater cell product quality as assessed through an identity assay and cell viability is associated with superior outcomes after autologous chondrocyte implantation (ACI) for symptomatic cartilage defects. Study Design: Cohort study; Level of evidence, 3. Methods: Seventy-nine patients with a minimum follow-up of 2 years were included in this study. Of these, 67 patients were available for imaging assessment utilizing the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. Patients were assigned to groups either below or above the cohort's mean based on their individual cell identity score and viability percentage. Results: Patients were predominantly female (57.7%) with a mean age of 30.0 ± 9.3 years. No differences were seen between Knee injury and Osteoarthritis Outcome Score, Lysholm, Tegner, or International Knee Documentation Committee Subjective Knee Evaluation Form within the viability and cell identity groups at a final follow-up of 3.8 ± 1.4 years after ACI (P >.05). In a subset of patients, the mean MOCART score was 68.3 ± 15.6 at an average magnetic resonance imaging follow-up of 17.7 ± 9.56 months. Low cell identity was significantly associated with the degree of defect filling (P =.025), integration of border zone (P =.01), effusion (P =.024), and ACI graft failure (P =.002). Patients with above-average cell identity scores had a significantly higher survival rate at 5-year follow-up compared with patients with below-average scores (95.8% vs 64.7%; P =.013). Cell viability did not influence MOCART subscales or graft failure (all P >.05). Cell viability and identity showed no significant correlation with each other (r = −0.045; P =.694). Conclusion: Cell identity was significantly correlated with structural repair quality and graft survival after second-generation ACI for symptomatic chondral lesions in the knee. While improved imaging outcome and higher graft survivorship were associated with a higher individual cell identity score indicating a higher chondrocyte/synoviocyte gene expression ratio in the final cell product, clinical outcome did not correlate with the identity score. [ABSTRACT FROM AUTHOR]

Background: Subchondral changes, specifically cyst formation, are a known finding after osteochondral allograft (OCA) transplantation. Purpose/Hypothesis: The purpose was to determine potential predictive associations between preoperative patient characteristics or OCA morphology and postoperative OCA appearance as assessed by the osteochondral allograft magnetic resonance imaging scoring system (OCAMRISS) at 6-month follow-up. It was hypothesized that preoperative patient factors or OCA morphology is associated with postoperative OCAMRISS scores. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This study evaluated 74 OCAs that were implanted in the femoral condyles of 63 patients for the treatment of symptomatic osteochondral defects in the knee. Postoperative magnetic resonance imaging was obtained at a mean ± SD follow-up of 5.5 ± 1.0 months. A musculoskeletal radiologist scored all grafts according to the OCAMRISS. Point biserial correlation, Mann-Whitney U test, Fisher exact test, and chi-square test were used to distinguish associations between OCAMRISS subscales and age, sex, smoker status, body mass index, previous surgery, concomitant surgery, bone marrow augmentation, graft location, graft size, and bony graft thickness. Results: OCA bony thickness showed significant correlation with cystic changes at the graft-host junction (P =.019). Grafts with cystic formation were significantly thinner than grafts without cystic changes (P =.008). The odds ratio for grafts with <5-mm bony thickness demonstrating cystic changes was 4.9 (95% CI, 1.5-16.1; P =.009). Bony graft thickness was not associated with graft integration, but 40% of grafts with a bony thickness >9 mm presented with a residual osseous cleft, as opposed to 11.3% of thinner grafts (P =.1). The augmentation with bone marrow aspirate did not affect osseous graft integration or subchondral cystic formation (P =.375 and P =.458, respectively). Conclusion: Osteochondral allograft thickness is associated with subchondral cyst formation at short-term follow-up. Thin grafts demonstrate a substantially increased risk of developing subchondral cysts at the graft-host junction after OCA transplantation. Conversely, thicker grafts may negatively affect osseous graft integration. Hence, surgeons should be aware of the potential pitfalls of transplanting thin or thick grafts regarding cystic formation and delay of osseous integration after cartilage resurfacing. [ABSTRACT FROM AUTHOR]

Background: The use of autologous chondrocyte implantation (ACI) remains limited, even though multiple studies have demonstrated success rates exceeding 75%. The procedure is perceived as invasive and technically challenging, presenting barriers to more widespread adoption. Purpose/Hypothesis: The objective of this study was to investigate whether outcomes and the failure rate of a simplified ACI technique (cs-ACI) were comparable with those of the more complicated traditional technique of a chondrocyte suspension injected under a collagen membrane (cACI). We hypothesized that the change in technique would not negatively affect outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Thirty-nine patients treated with the cs-ACI technique fulfilled the inclusion requirements. A group of 45 patients treated previously with standard cACI was used as a comparison. The functional outcomes were prospectively collected both preoperatively and postoperatively at the last follow-up. Failure was defined as any graft removal of more than 25% of the original defect size. Magnetic resonance imaging was performed postoperatively, and scans were assessed using a modified MOCART (magnetic resonance observation of cartilage repair tissue) scoring system. Results: Group demographics were not significantly different, except for the defect size and mean follow-up: 4.09 years in the cACI group and 2.46 years in the cs-ACI group. Significant improvements were seen in all outcome measures except the Tegner score from the preoperative baseline to the latest follow-up for both the cACI group (International Knee Documentation Committee [IKDC] score, from 42.0 to 63.4; Knee injury and Osteoarthritis Outcome Score [KOOS]-Pain subscore, from 58.7 to 77.1; Lysholm score, from 57.2 to 69.7; and Tegner score, from 3.5 to 4.2) and the cs-ACI group (IKDC score, from 45.6 to 68.0; KOOS-Pain subscore, from 66.6 to 84.7; Lysholm score, from 53.7 to 75.4; and Tegner score, from 3.2 to 3.8). No significant difference was found between the groups at the latest follow-up. The failure rate at 2 years was not significantly different, while the total failure rate over the entire study period was significantly lower in the cs-ACI group than the cACI group (5% vs 24%, respectively). The overall MOCART score was not significantly different between the groups. Conclusion: The treatment of full-thickness articular cartilage defects with a simplified cell-seeded ACI technique demonstrated no significant differences in the failure rate and patient-reported outcomes when compared with a standard technique utilizing interrupted sutures and the injection of a cell suspension under a collagen membrane. [ABSTRACT FROM AUTHOR]

Background: Widespread adoption of fresh allograft transplantation remains limited, predominantly by supply issues. To overcome these limitations, a preshaped, cylindrical sterilized and decellularized osteochondral allograft (SDOCA) implant was recently introduced as a clinical treatment option. Purpose: To evaluate functional outcomes and graft survivorship among patients treated with the SDOCA implant for knee cartilage injuries. Study Design: Case series; Level of evidence, 4. Methods: An institutional review board–approved database was used to identify a series of patients with prospectively collected data who had been treated with the SDOCA implant. The surgeries were performed at 2 centers by 2 surgeons. Patient-reported outcomes, magnetic resonance imaging (MRI), and the number and type of reoperations were assessed. Failure was defined as structural damage of the graft diagnosed by arthroscopy or MRI, and any reoperation resulting in removal of the allograft. Patients were evaluated pre- and postoperatively using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Marx Sports Activity Scale. MRI was assessed preoperatively and postoperatively. Results: There were 32 patients with a mean age (±SD) of 35.1 ± 10.6 years; 59% were male. Twenty-three (72%) knees had previous surgery. The mean defect area (±SD) was 2.9 ± 2.0 cm2, and the mean allograft size was 13.18 ± 2.3 mm (6 grafts ≤9 mm and 59 grafts ≥11 mm). The median number of allografts per knee was 2 (range, 1-5 grafts). Twenty-three of the 32 knees (72%) were considered failures by the definition detailed above. Of these, 14 knees (43%) had further surgery after the index procedure. Implant survivorship was 19.6% at 2 years. The mean follow-up duration was 1.29 years (range, 0.11-2.8 years). KOOS pain, activities of daily living (ADL), sports and recreation (sport/rec), and knee-related quality of life improved significantly from the preoperative visit to latest follow-up. Age was significantly predictive of failure, with a hazard ratio of 1.68 per 1 SD older (95% CI, 1.05-2.68; P = .030). The MOCART (magnetic resonance observation of cartilage repair tissue) feature effusion was the only score to correlate with KOOS (symptoms, pain, ADL, sport/rec). Conclusion: The SDOCA implant demonstrated a 72% failure rate within the first 2 years of implantation at these 2 institutions. [ABSTRACT FROM AUTHOR]