The factors associated with anterior cruciate ligament (ACL) tears are not completely clear. Some studies have shown that patients with a narrow intercondylar notch have a predisposition for ACL tears. To determine the relationship between the α angle and intercondylar notch width measurements and ACL tears. Case-control study; Level of evidence, 3. A total of 530 patients (308 with ACL rupture, 222 with healthy ACLs) were included in this study. The α angle and intercondylar width were measured from magnetic resonance images (MRIs). Binary logistic regression analysis was performed to determine the influence of the variables on ACL status (normal or torn). Odds ratios (ORs) and their respective 95% CIs were also calculated. No significant differences in patient age and the affected knee were found between patients with normal or torn ACLs. The mean α angle was higher in patients with a torn ACL than in those with an intact one (57.5° ± 5.5° vs 56.2° ± 4.5°; P = .009). Intercondylar width was significantly lower in patients with a torn ACL than in those with an intact one (18.2 ± 3.1 vs 19.5 ± 3.6 mm; P < .001). A highly significant difference between men and women was found for mean intercondylar notch width (19.3 ± 3.3 vs 17.4 ± 3.1 mm; P < .001). In a logistic regression model, sex, intercondylar width, and α angle were statistically significant when adjusted for age. Study results suggest that the ACL tears are associated with a narrow intercondylar notch and a high α angle, and that tears occur more frequently in men than in women. The model proposed in this study could be used by the physician in the medical office as a tool to identify the risk factors that may predispose a patient for a potential ACL tear.

Background Futsal started being played in 1930 and the number of futsal players has increased all over the world ever since. Nonetheless, despite the fact that Spain is one of the most relevant national teams worldwide, information on the incidence of injuries and their anthropometric characteristics is sparse in this country. Aim To analyse medical assistance provided to players in their prematch concentration camps with the Spanish national team over five seasons, from 2010–2011 to 2014–2015, and also to collect data regarding anthropometric characteristics. Materials and methods This is a retrospective and detailed study of injuries players suffered over these five seasons. All variables were registered on an Excel spreadsheet and later analysed statistically. Results 411 injuries were studied in total. The dominant somatotype was mesomorph and the injured pivots were both the most endomorphic and the most mesomorphic. The most injured body structure was the hamstring muscles, occurring due to training and intrinsic mechanisms, where fatigue was the most frequent diagnosis. Only a few complementary examinations were carried out and prematch withdrawal was rare. Discussion The skinfold test total sum was lower than that of the Spanish 11-a-side players or than that in the lower category futsal Spanish players. In various research studies analysing exclusively injuries occurring in matches, the most frequent injury is ligament injury by extrinsic mechanism. The body mass index was not a useful parameter when assessing players’ appropriate weight. Most injuries occurred in training sessions, mostly by intrinsic mechanism; the highest percentage of traumatic injuries occurred in official matches.

Purpose: Two-year follow-up to assess efficacy and safety of high-density autologous chondrocyte implantation (HD-ACI) in patients with cartilage lesions in the ankle. Design: Twenty-four consecutive patients with International Cartilage repair Society (ICRS) grade 3-4 cartilage lesions of the ankle were included. Five million chondrocytes per cm² of lesion were implanted using a type I/III collagen membrane as a carrier and treatment effectiveness was assessed by evaluating pain with the visual analogue scale (VAS) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score at baseline, 12-month, and 24-month follow-up, together with dorsal and plantar flexion. Magnetic resonance observation for cartilage repair tissue (MOCART) score was used to evaluate cartilage healing. Histological study was possible in 5 cases. Results: Patients’ median age was 31 years (range 18-55 years). Median VAS score was 8 (range 5-10) at baseline, 1.5 (range 0-8) at 12-month follow-up, and 2 (rang e0-5) at 24-month follow-up ( P < 0.001). Median AOFAS score was 39.5 (range 29-48) at baseline, 90 (range 38-100) at 12-month follow-up, and 90 (range 40-100) at 24-month follow-up ( P < 0.001). Complete dorsal flexion significantly increased at 12 months (16/24, 66.7%) and 24 months (17/24, 70.8%) with regard to baseline (13/24, 54.2%) ( P = 0.002). MOCART at 12- and 24-month follow-ups were 73.71 ± 15.99 and 72.33 ± 16.21. Histological study confirmed that neosynthetized tissue was cartilage with hyaline extracellular matrix and numerous viable chondrocytes. Conclusion: HD-ACI is a safe and effective technique to treat osteochondral lesions in the talus, providing good clinical and histological results at short- and mid-term follow-ups.

We hypothesized that implanting cells in a chondral defect at a density more similar to that of the intact cartilage could induce them to synthesize matrix with the features more similar to that of the uninjured one. We compared the implantation of different doses of chondrocytes: 1 million (n = 5), 5 million (n = 5), or 5 million mesenchymal cells (n = 5) in the femoral condyle of 15 sheep. Tissue generated by microfracture at the trochlea, and normal cartilage from a nearby region, processed as the tissues resulting from the implantation, were used as references. Histological and molecular (expression of type I and II collagens and aggrecan) studies were performed. The features of the cartilage generated by implantation of mesenchymal cells and elicited by microfractures were similar and typical of a poor repair of the articular cartilage (presence of fibrocartilage, high expression of type I collagen and a low mRNA levels of type II collagen and aggrecan). Nevertheless, in the samples obtained from tissues generated by implantation of chondrocytes, hyaline-like cartilage, cell organization, low expression rates of type I collagen and high levels of mRNA corresponding to type II collagen and aggrecan were observed. These histological features, show less variability and are more similar to those of the normal cartilage used as control in the case of 5 million cells implantation than when 1 million cells were used. The implantation of autologous chondrocytes in type I/III collagen membranes at high density could be a promising tool to repair articular cartilage.

Objective . The aim of this work was to study the short- and mid-term effectiveness and safety of high-density autologous chondrocyte implantation (HD-ACI) in the first 50 patients with knee cartilage damage treated in our unit. Design . Fifty consecutive patients with cartilage lesions (Outerbridge grade III-IV) in the knee treated with HD-ACI were included in this study. Chondrocytes were isolated from a nonbearing cartilage area biopsy and were cultured until 40 to 50 million cells were obtained. Five million chondrocytes per cm ² of a porcine collagen type I/III membrane were implanted covering the defect. Procedure effectiveness was assessed by evaluating pain, swelling, and range of mobility (flexion and extension) at 6-, 12-, and 24-month follow-up. The International Knee Documentation Committee (IKDC) subjective evaluation form was used to evaluate symptoms and functions of the knee. Results . The percentage of patients with pain and swelling decreased progressively in the following visits, with differences being statistically significant ( P < 0.001 and P = 0.040, respectively). IKDC scores improved progressively throughout the 24-month follow-up ( P < 0.001). Thus, the mean IKDC score improvement was 26.3 points (95% confidence interval [CI] = 18.2-34.4 points) at 12 months and 31.0 points (95% CI = 22.9-39 points) at 24 months. No significant differences were found when performing extension ( P = 0.112). Flexion significantly improved by 25.1° at 24-month follow-up ( P = 0.013). Conclusions . HD-ACI is a safe and effective technique for the treatment of cartilage defects, improving clinical and subjective perception of knee functionality. These preliminary results encourage future studies comparing this technique with traditional ACI.

Hyaline cartilage’s inability to self-repair can lead to osteoarthritis and joint replacement. Various treatments, including cell therapy, have been developed for cartilage damage. Autologous chondrocyte implantation (ACI) is considered the best option for focal chondral lesions. In this article, we aimed to create a narrative review that highlights the evolution and enhancement of our chondrocyte implantation technique: High-Density-ACI (HD-ACI) Membrane-assisted Autologous Chondrocyte Implantation (MACI) improved ACI using a collagen membrane as a carrier. However, low cell density in MACI resulted in softer regenerated tissue. HD-ACI was developed to improve MACI, implanting 5 million chondrocytes per cm², providing higher cell density. In animal models, HD-ACI formed hyaline-like cartilage, while other treatments led to fibrocartilage. HD-ACI was further evaluated in patients with knee or ankle defects and expanded to treat hip lesions and bilateral defects. HD-ACI offers a potential solution for cartilage defects, improving outcomes in regenerative medicine and cell therapy. HD-ACI, with its higher cell density, shows promise for treating chondral defects and advancing cartilage repair in regenerative medicine and cell therapy.