Secondary matrix-associated autologous chondrocyte implantation after failed cartilage repair shows superior results when combined with autologous bone grafting: Findings from the German Cartilage Registry (KnorpelRegister DGOU).

PURPOSE: The aim of this study was to evaluate whether additive autologous bone grafting (ABG) improves clinical outcome and survival in revision matrix-associated autologous chondrocyte implantation (M-ACI) after failed cartilage repair (CR). METHODS: A retrospective, registry-based, matched-pair analysis was performed to compare patient-reported outcomes and survival in secondary M-ACI with or without additional bone grafting for focal full-thickness cartilage defects of the knee and to compare it with those in primary M-ACI. Patients were matched for age, sex, body mass index, defect size and localization, and number of previous CRs. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was assessed over a follow-up period of 36 months. The patient acceptable symptomatic state, the clinical response rate and the survival of the subgroups were determined. RESULTS: A total of 818 patients were matched. Revision M-ACI (n = 238) with concomitant bone grafting was associated with significantly higher PRO as measured by KOOS (80.8 ± 16.8 vs. 72.0 ± 17.5, p = 0.032) and higher CRR (81.4% vs. 52.0%, p = 0.018) at 36 months compared to patients with revision M-ACI alone. KOOS and KOOS improvement in these patients did not differ from those who underwent primary M-ACI (p = n.s.). The combination of M-ACI and ABG resulted in a significantly higher KOOS at 36 months than M-ACI alone, regardless of whether bone marrow stimulation (89.6 ± 12.5 vs. 68.1 ± 17.9, p = 0.003) or ACI (82.6 ± 17.0 vs. 72.8 ± 16.0, p = 0.021) was performed before. Additional bone grafting results in equivalent survival rates at 7 years in secondary compared to primary M-ACI (83% vs. 84%, p = n.s.). CONCLUSIONS: Regardless of the type of previous CR, additional bone grafting in secondary M-ACI improves the clinical outcome, response rate and survival at 36 months compared to M-ACI alone. Secondary M-ACI with ABG had comparable clinical response and survival rates to primary M-ACI. Therefore, subchondral bone should be treated even in cases of mild bone involvement in revision M-ACI. LEVEL OF EVIDENCE: Level III.

Factors Influencing Long-term Outcomes After Matrix-Induced Autologous Chondrocyte Implantation: Long-term Results at 10 Years.

BACKGROUND: Matrix-induced autologous chondrocyte implantation (MACI), the third-generation of the technique, is an established procedure for the treatment of focal cartilage defects in the knee. However, the literature lacks long-term results of MACI with good statistical power. PURPOSE: To determine long-term survival and patient-reported outcomes (PROs) in a representative cohort and to identify patient- and surgery-related parameters that may influence long-term clinical outcomes. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 103 patients were clinically evaluated at the current follow-up of 8.1 years (range, 5-11.9 years). PRO measures (PROMs) included the Knee injury and Osteoarthritis Outcome Score (KOOS), EQ-5D, visual analog scale for pain, and Tegner Activity Scale. Magnetic resonance imaging results were evaluated by using the AMADEUS (area measurement and depth and underlying structures) and MOCART (magnetic resonance observation of cartilage repair tissue) 2.0 knee score classification systems. Potential factors influencing PROs were first identified univariately and investigated in a multivariate regression model. RESULTS: The defects had a mean size of 4.8 cm2 (range, 1.2-12 cm2) and were predominantly femorotibial (66%). The mean Kaplan-Meier survival rate of revision for any reason was 97.2% ± 1.6% at 10 years. In comparison to preoperative values, all PROMs were significantly improved at the current follow-up (P < .05). The MOCART 2.0 score peaked at 12 months (mean, 80.2 ± 15.3 months) and showed no significant change at 96 months (mean, 76.1 ± 19.5 months; P = .142). The linear multivariate regression model identified an association of body mass index (BMI), MOCART 2.0 score, and number of previous knee surgeries with KOOS (R2 = 0.41; f2 = 0.69). Further analysis of the individual determinants revealed an optimal BMI range of 20 to 29 for favorable PROs at 96 months. Significant correlations of MOCART subscores with the overall KOOS were found for graft surface and structure, bony reaction, and subchondral detectable changes. Only 30% of patients with 2 previous surgeries and 20% of patients with 3 previous surgeries achieved a Patient Acceptable Symptom State (χ2 = 10.93; P = .012). CONCLUSION: The present study shows consistently good long-term clinical outcomes after MACI with a low revision rate and high patient satisfaction. BMI and number of previous knee surgeries may influence clinical outcomes and should be considered in patient selection and education. There is a correlation between graft structure, subchondral bone changes on magnetic resonance imaging, and long-term PROMs.

Favourable clinical outcomes and low revision rate after M-ACI in adolescents with immature cartilage compared to adult controls: Results at 10 years.

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.

Neutral to slightly undercorrected mechanical leg alignment provides superior long-term results in patients undergoing matrix-associated autologous chondrocyte implantation.

PURPOSE: The aim of this study was to evaluate the role of leg alignment on long-term clinical outcome after matrix-associated autologous chondrocyte implantation (M-ACI) and to define an individualized target range to optimize clinical outcome. METHODS: The present study examined patients who underwent M-ACI of the femoral condyle. The Knee Injury and Osteoarthritis Outcome Score (KOOS) and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) were used to assess the results. Clinical outcomes were related to Patient Acceptable Symptomatic State (PASS). For intra- and interobserver reliability of mechanical tibiofemoral angle, mechanical medial proximal tibial angle and mechanical lateral distal femoral angle, we calculated intraclass correlation coefficients using a two-way mixed model with absolute agreement. A regression model and receiver-operating characteristics curve were used to identify an individual range of alignment where a favourable clinical outcome could be expected in the long term. RESULTS: Additional osteotomy was performed in 50% of patients with similar clinical outcomes as physiologically aligned patients (p > 0.05). The curve-fitting regression model identified a target range of -2.5° valgus to 4.5° varus for ideal postoperative alignment (R2 = 0.12, p = 0.01). Patients within this range were more likely to achieve PASS (70% vs. 27%, p = 0.001). In medially treated defects, a refined range of -2.5° valgus to 4° varus alignment was found (R2 = 0.15, p = 0.01). These patients were more likely to achieve PASS (67% vs. 30%, p = 0.01) and showed favourable postoperative KOOS and MOCART scores (p = 0.02). Patients with lateral defects were more likely to achieve PASS within a range of -2° valgus and 0.5° varus (90% vs. 45%, p = 0.03) and showed favourable postoperative KOOS and MOCART scores (p = not significant). CONCLUSIONS: An individual range of leg alignment-whether achieved by osteotomy or physiologic alignment-should be respected in M-ACI treatment. A neutral to slightly undercorrected alignment favours the postoperative outcome after M-ACI. When planning surgery for patients with focal cartilage defects of the femoral condyle, these ranges should be recognized as critical factors. LEVEL OF EVIDENCE: Level III.

The role of autologous bone grafting in matrix-associated autologous chondrocyte implantation at the knee: Results from the German Cartilage Registry (KnorpelRegister DGOU).

PURPOSE: To investigate whether concomitant autologous bone grafting adversely affects clinical outcome and graft survival after matrix-associated autologous chondrocyte implantation (M-ACI). METHODS: The present study examines registry data of patients who underwent M-ACI with or without autologous bone grafting for large-sized chondral or osteochondral defects. Propensity score matching was performed to exclude potential confounders. A total of 215 patients with similar baseline characteristics were identified. Clinical outcome was assessed at the time of surgery and at 6, 12, 24, 36 and 60 months using the Knee Injury and Osteoarthritis Outcome Score (KOOS). KOOS change, clinical response rate, KOOS subcomponents and failure rate were determined. RESULTS: Patients treated with M-ACI and autologous bone grafting achieved comparable clinical outcomes compared with M-ACI alone. At 24 months postoperatively, the patient-reported outcome (PRO) of patients treated with M-ACI and autologous bone grafting was even significantly better as measured by KOOS (74.9 ± 18.8 vs. 79.2 ± 15.4; p = 0.043). However, the difference did not exceed the minimal clinically important difference (MCID). In patients with M-ACI and autologous bone grafting, a greater change in KOOS relative to baseline was observed at 6 (9.3 ± 14.7 vs. 15.0 ± 14.7; p = 0.004) and 12 months (12.6 ± 17.2 vs. 17.7 ± 14.6; p = 0.035). Overall, a high clinical response rate was observed in both groups at 24 months (75.8% vs. 82.0%; p = n.s.). The estimated survival at the endpoint of reoperation for any reason was 82.1% (SD 2.8) at 8.4 years for isolated M-ACI and 88.7% (SD 2.4) at 8.2 years for M-ACI with autologous bone grafting (p = 0.039). CONCLUSIONS: Even in the challenging cohort of large osteochondral defects, the additional treatment with autologous bone grafting leads to remarkably good clinical outcomes in patients treated with M-ACI. In fact, they tend to benefit more from surgery, have lower revision rates and achieve clinical response rates earlier. Subchondral bone management is critical to the success of M-ACI and should be addressed in the treatment of borderline defects. LEVEL OF EVIDENCE: Level III.

How Does Age Affect Injury Characteristics in Young Elite Footballers?-A Prospective Cohort Study of a German Youth Academy.

BACKGROUND: Little is known about age-related changes in injury characteristics and burden, and existing data are inconsistent, highlighting the need for new studies on this topic. This study aimed to describe age-related injury risk, severity and burden in a German elite youth football academy. METHODS: A prospective cohort study was conducted in the 2012/2013 season, reporting 109 time-loss injuries among 138 young athletes playing at an elite football academy in Germany. For the most severe injuries, the injury burden in the different age groups was considered separately. RESULTS: Athletes missed a total of 2536 days of exposure, resulting in an overall incidence of 2.6 per 1000 h (1.7-3.0; 95% CI) and a burden of 60.6 days lost per 1000 h (40.8-80.3; 95% CI). The incidence and burden of joint sprains and muscle injuries were higher in the older age groups. Physeal injuries peaked in the U14 age group during the pubertal growth spurt. Bone injuries and contusions showed no age trend. CONCLUSION: Injury characteristics vary with age. The overall incidence, severity and burden of injuries increased with the age of the athletes. To ensure the optimal development of young athletes, it is important to be aware of the differences in injury susceptibility between age groups in order to implement tailored prevention programmes.

Injury Patterns and Incidence in an Elite Youth Football Academy-A Prospective Cohort Study of 138 Male Athletes.

BACKGROUND: There is a lack of evidence regarding injury incidence in German elite youth football academies, and the risk of re-injury is unknown. Therefore, the objectives of this study were (1) to determine injury patterns and incidence in an elite youth football academy in Germany, (2) to monitor overuse-/trauma-related injuries over the course of the season, and (3) determine the risk of re-injury. METHODS: A prospective cohort study was conducted in the 2012/2013 season among 138 male players from an elite youth football academy in Germany. Injuries were recorded according to the consensus statement on injury definitions and data collection in studies of football injuries. Injury incidence was reported as the number of injuries per 1000 h of exposure and the number of injuries per squad season. RESULTS: A total of 109 injuries were reported, resulting in a cumulative time-loss of 2536 days. A squad of 25 players sustained 19.7 injuries per season, with an average of 23.3 days (15.7-30.9; 95% CI lower-upper) of absence per injury. Ligament sprains (28%), muscle strains (19%) and physeal injuries (12%) were the most common causes of time-loss. Physeal injuries were the most common severe type of injury (29%), with a mean time-loss of 29.7 days (18.2-41.2; 95% CI lower-upper). Re-injuries accounted for 3% of all injuries and resulted in significantly more time-loss than non-re-injuries (60 vs. 23 days; p = 0.01). CONCLUSION: In the youth academies studied, a team of 25 players sustained an average of 19.7 injuries per season, resulting in a cumulative time-loss of 459 days. Physeal injuries are a major contributor to severe injuries and therefore require special attention.

[Platelet-rich plasma (PRP) : Compositional analysis with different dietary habits and timing of blood sampling]. / "Platelet-rich plasma" (PRP) : Analyse der Zusammensetzung bei unterschiedlichem Ernährungsverhalten und Blutentnahmezeitpunkt.

The variability of PRP is a major contributor to the lack of evidence regarding the therapeutic effect of PRP in musculoskeletal diseases. In a large study, we are currently investigating factors that may influence PRP variability. Interim results showed that concentrations of IL­6, but not IGF­1 or cellular constituents, were significantly decreased in PRP samples from vegans compared with omnivores and tended to be decreased compared to samples from vegetarians. This suggests that diet may have a significant influence on therapeutically active PRP constituents. However, the constituents studied here did not appear to be significantly affected by the timing of the sampling. Identification of significant variables affecting PRP composition will be critical to provide sufficient medical evidence for the therapeutic effects of PRP in orthopedic conditions.

[New treatment methods in competitive sports : What can we learn from the medical care of top athletes?] / Neue Therapieverfahren im Wettkampfsport : Was können wir aus der Betreuung von Spitzensportlern lernen?

BACKGROUND: As elite sport becomes more professional, the medical-psychological care of athletes is an important factor in providing them with the best possible support and thus optimising their performance. Our experience in the fields of prevention, conservative and surgical treatment, and rehabilitation also provides valuable insights for the treatment of our patients in daily practice. PREVENTION: Designed to improve static and dynamic muscle strength, kinaesthetic sensitivity, and neuromuscular control, the FIFA 11+ injury prevention programme is a three-part warm-up programme that is widely used in coaching and recreational sports. CONSERVATIVE TREATMENT: Platelet-rich plasma (PRP) is probably the most widely used orthobiologic treatment modality for the conservative management of tendon, muscle and cartilage injuries. Its effectiveness depends on the underlying pathology and the affected body region. The best evidence exists for the treatment of patellar tendinitis ("jumper's knee") and epicondylitis humeri radialis ("tennis elbow"). SURGICAL TREATMENT: The treatment of ACL injuries in competitive athletes is challenging due to the high physical demands. Prompt surgical intervention, anatomical reconstruction and additional extra-articular stabilisation are associated with improved surgical outcomes. Graft selection must be individualised, adapted to the needs of the athletes and our patients. REHABILITATION: Electromyography (EMG) is a diagnostic tool to identify muscular imbalances in rehabilitation and, at the same time, to help reduce them through biofeedback training. COGNITIVE TRAINING: Training for the development of basic cognitive skills helps to optimise performance through its potentially positive influence on the executive functions of athletes.