Background: There is a lack of evidence regarding the impact of time loss, match exposure, and age at injury on career progression in elite football. Therefore, the aim of this study was to identify injury characteristics and their influence on career progression in a German youth academy. Methods: During the 2012/2013 season, a prospective cohort study reported 107 time-loss injuries among 130 young athletes from an elite German soccer academy. Individual career progression was analyzed using 10-year data. Results: Injuries and time loss were not associated with career progression (p > 0.05) in the overall cohort. In the U17 and U19 groups, 24% were able to reach the professional level, with injuries significantly decreasing this probability (p = 0.002). Injuries lasting more than 28 days had a negative impact on career progression compared to minor injuries (30% vs. 10%; p = 0.02). Conclusions: Not only the characteristics of injuries, but also their impact on career development, vary with age. In the U17 and U19 age groups, serious injuries resulting in more than 28 days of absence have a negative impact on career progression. It is important to be aware of these effects in order to focus on the prevention of long-term injuries to ensure the optimal development of young athletes.

(1) Background: In the treatment of periprosthetic joint infection (PJI), the individual host status and previous surgical procedures appear to have a relevant influence on success rates and clinical outcome of knee revision surgery. Current data about the predictive value are limited in this subgroup of patients. (2) Methods: Retrospectively, 107 patients (109 knees) undergoing two-stage exchange knee arthroplasty for PJI using a rotating-hinge design with at least two years follow-up. The cumulative incidence (CI) for different endpoints was estimated with death as competing risk. Univariate and multivariate analyses for potential predictive factors were performed. Patient-related outcome measures (PROMs) for clinical outcome were evaluated. (3) Results: At 8 years, the CI of any revision was 29.6%, and of any reoperation was 38.9%. Significant predictors for risk of re-revision were the Charlson Comorbidity Index (CCI) and the number of previous surgical procedures prior to explanation of the infected implant. The functional and clinical outcome demonstrated acceptable results in the present cohort with a high comorbidity level. (4) Conclusions: A compromised host status and multiple previous surgical procedures were identified as negative predictors for re-revision knee surgery in the treatment of PJI. Reinfection remained the major reason for re-revision. Overall mortality was high.

Purpose: To evaluate long‐term outcomes of cemented, mobile‐bearing medial unicompartmental knee arthroplasty (UKA) in patients aged 60 or younger, focusing on implant survival, functional results, patient‐reported outcome measures (PROMs), and radiographic findings over >10 years.Methods: This retrospective single‐centre study included 119 knees (102 patients). Implant survival was evaluated using Kaplan–Meier analysis. PROMs included the Oxford Knee Score (OKS), American Knee Society Score (AKSS), UCLA Activity Score and Visual Analogue Scale (VAS). Assessments were performed preoperatively, at mid‐term (2–10 years), and at long‐term follow‐up (>10 years). OKS and AKSS were analysed in relation to Patient Acceptable Symptom State (PASS) thresholds. Radiographs were graded using the Kellgren–Lawrence classification to evaluate lateral osteoarthritis (LOA) progression.Results: The implant survival rate was 86.7% (95% CI: 78.5–91.9%) at 15 years, and 81.7% (95% CI: 71.4%–88.5%) at 17.5 years. Revision surgery was required in 18 knees (mean time to revision: 8.7 years), primarily due to progression of LOA. All PROMs improved significantly from baseline to the final follow‐up (mean: 16 years; p < 0.0001). Although minor functional declines occurred between mid‐ and long‐term follow‐ups, these were not statistically significant (p > 0.05), except for functional AKSS. At the final assessment, 96% of patients exceeded the PASS threshold for OKS, 84% for AKSS objective, and 80% for AKSS functional scores. Radiographic LOA progression was frequent but did not significantly impair functional outcomes.Conclusions: Cemented mobile‐bearing medial UKA in patients aged ≤60 years demonstrated high long‐term implant survival and sustained functional benefit. Even in the presence of radiographic LOA progression, clinical outcomes remained excellent. UKA represents a durable and effective treatment for younger patients with isolated medial compartment osteoarthritis.Level of Evidence: Level IV.

Purpose: The purpose of this study was to evaluate long‐term survival, patient‐reported outcomes (PROs) and radiographic results of matrix‐associated autologous chondrocyte implantation (M‐ACI) in adolescents with immature cartilage and compare them to adult controls.Methods: A retrospective matched‐pair analysis was performed comparing the PRO after M‐ACI for focal cartilage defect of the knee in cartilaginous immature adolescents to mature adults. Groups were matched for sex, body mass index, defect site and size, symptom duration and the number of previous knee surgeries. Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART 2.0) scores were assessed at least 60 months postoperatively. Patient acceptable symptomatic state (PASS) and clinical response rate in KOOS and KOOS subscores were calculated.Results: A total of 54 patients were matched. At a mean of 96 months (65–144 months), no surgical complications, graft hypertrophy or reoperations were noted in the cohorts studied. Adolescents showed superior PROs at the final follow‐up (76.9 ± 14.1 vs. 66.4 ± 15.0, p = 0.03) and were significantly more likely to achieve PASS (74.1% vs. 55.6%; p = 0.02) compared to the adult cohort. The KOOS subscale analysis showed long‐term benefits for adolescents in terms of symptom improvement, pain reduction, activities of daily living, sports and quality of life (p < 0.05). None of the patients in the adolescent group showed graft hypertrophy on magnet resonance imaging or signs of osteoarthritis on radiographs at long‐term follow‐ups.Conclusions: M‐ACI is an effective treatment for chondral defects of the knee in patients with immature cartilage with low revision rates and high patient satisfaction over the long term. Adolescents showed comparable clinical and radiographic results in the short and medium term, with slightly more favourable, clinically relevant functional results in adolescents in the long term. M‐ACI can be safely used in adolescents, and consideration should be given to expanding the indication to include these patients.Level of Evidence: Level III.

Introduction: The aim of the current study was to demonstrate short- to mid-term survivorship as well as clinical outcome of lateral unicompartmental knee replacement (UKR) with a fixed-bearing (FB) design from a non-designer center using the Oxford Fixed Lateral prosthesis. Materials and methods: This single-center retrospective cohort study reports the results of 133 consecutive lateral FB-UKR. Survivorship analysis was performed with different endpoints and clinical outcome was measured using the Oxford-Knee-Score (OKS), American-Knee-Society-Score (AKSS-O), range-of-motion (ROM) and visual-analog-scale for pain (VAS). Results: There were two revision surgeries with conversion to total knee replacements (TKR) due to persistent pain resulting in a survival rate of 98.5% (95% CI 93.5–99.6) with a mean follow-up (FU) of 3.3 ± 1.8 years (range 1–8.5). All outcome scores, VAS and ROM showed a significant improvement at final FU (p < 0.001). The OKS improved from 26 ± 7.8 (range 11–45) preoperatively to 39 ± 8.3 (range 13–48), the AKSS-O from 49.2 ± 14.6 (range 18–90) to 81.8 ± 15.1 (range 40–100), the AKSS-F from 53 ± 23.7 (range 0–100) to 80.4 ± 21.4 (range 5–100) and the ROM from 118 ± 17 (range 90–160) to 134 ± 9.5 (range 100–155). Conclusions: The short- to mid-term results following lateral FB-UKR demonstrate a high survivorship and good clinical outcome from an independent series. We, therefore, suggest that FB-UKR is a safe treatment option for isolated lateral OA if sufficient surgical experience is provided. Level of evidence: Retrospective cohort study, level IV.

Aims: Unicompartmental knee arthroplasty (UKA) is one option in the treatment of isolated unicompartmental advanced osteoarthritis (OA). While long-term results exist for medial mobile-bearing (MB) UKA, evidence regarding lateral MB-UKA is still limited. The Oxford Domed Lateral (ODL) implant aims to reduce the bearing dislocation rate in lateral MB-UKA through enhanced bearing entrapment. However, the long-term performance of this implant remains unclear. This study evaluated the long-term survival and clinical outcomes of the ODL in a non-designer centre.Methods: This single-centre retrospective analysis included 115 lateral MB-UKAs using the ODL performed between January 2006 and December 2014. The primary endpoint of the study was implant survival, defined as the time until a revision procedure was required for any reason. Secondary outcomes included Oxford Knee Score (OKS), Forgotten Joint Score (FJS), pain, satisfaction, and Tegner Activity Scale (TAS). Survival was assessed using Kaplan-Meier analysis.Results: At ten years, the cumulative implant survival rate was 74.8% (95% CI 65.2 to 82.1; number at risk = 71), with bearing dislocation (8.5%) and OA progression (10.4%) as leading revision causes. In 55 non-revised knees with a mean follow-up of 13.4 years (SD 1.8), the mean postoperative OKS improved significantly to 37.8 (SD 9.1) (p < 0.001). Additionally, 85.5% of patients (n = 47) reported satisfaction, with a mean FJS of 65.9 (SD 32.2) and TAS of 2.8 (SD 1.1). However, only 76.4% (n = 42) attained the patient-acceptable symptom state for OKS and FJS.Conclusion: This is the first long-term ODL study from a non-designer centre; our results demonstrated high failure rates due to bearing dislocation and OA progression, despite satisfactory clinical outcomes in non-revised patients. The disproportionately high risk of failure suggests that the MB design should be abandoned in favour of a fixed-bearing device for lateral UKA.Cite this article: Bone Joint J 2025;107-B(3):322–328.