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.
Elaborate bioreactor cultivation or expensive growth factor supplementation can enhance extracellular matrix production in engineered neocartilage to provide sufficient mechanical resistance. We here ...investigated whether raising extracellular calcium levels in chondrogenic cultures to physiologically relevant levels would provide a simple and inexpensive alternative to enhance cartilage neogenesis from human articular chondrocytes (AC) or bone marrow-derived mesenchymal stromal cells (BMSC). Interestingly, AC and BMSC-derived chondrocytes showed an opposite response to a calcium increase from 1.8 mM to 8 mM by which glycosaminoglycan (GAG) and collagen type II production were elevated during BMSC chondrogenesis but depressed in AC, leading to two-fold higher GAG/DNA values in BMSC-based neocartilage compared to the AC group. According to control treatments with Mg
or sucrose, these effects were specific for CaCl
rather than divalent cations or osmolarity. Importantly, undesired pro-hypertrophic traits were not stimulated by calcium treatment. Specific induction of PTHrP mRNA and protein by 8.0mM calcium only in AC, along with negative effects of recombinant PTHrP
on cartilage matrix production, suggested that the PTHrP pathway contributed to the detrimental effects in AC-based neocartilage. Altogether, raising extracellular calcium levels was discovered as a novel, simple and inexpensive stimulator for BMSC-based cartilage neogenesis without the need for special bioreactors, whereas such conditions should be avoided for AC.
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.
: 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.
: 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.
: Injuries and time loss were not associated with career progression (
> 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 (
= 0.002). Injuries lasting more than 28 days had a negative impact on career progression compared to minor injuries (30% vs. 10%;
= 0.02).
: 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.
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.
Abstract Background The successful treatment of atrophic tibia non-unions and tibia non-unions with large bone defects or infections is a major challenge in orthopedic and trauma surgery. This ...article evaluates the use of the ‘diamond concept’ using a one-step or two-step procedure according to ‘Masquelet technique’ in the treatment of atrophic tibia non-unions. Methods Between February 2010 and March 2014, 102 patients with atrophic non-unions were treated according to the ‘diamond concept’ in our center. Ninety-nine were available for follow-up. Forty-nine received a one-step treatment (Group 1, G1) and 50 patients received a two-step treatment according to the ‘Masquelet technique’ (Group 2, G2). Clinical and radiological parameters were measured preoperatively as well as 4, 6, and 12 weeks and 6 and 12 months postoperatively. In order to evaluate the subjective health of patients, we used the SF-12 questionnaire. Data analysis was performed one year after treatment. Results The rate of consolidation in G1 was 84% and 80% in G2. The time to heal in G2 was 8.6 ± 2.9 months, which is significantly longer than in G1 being 6.9 ± 3.1 months. In comparison patients in G1/G2 had an average of 3.2/6.7 previous major surgeries. In G1, 4 of 8 patients who did not heal successfully showed positive intraoperative cultures. In G2, 26 patients (52%) initially presented with positive cultures. The results of the SF-12 questionnaire improved in both groups during the postoperative follow-up, but showed no significant differences between groups. In 29 patients a gentamycin-coated nail was used for reosteosynthesis. These patients showed by trend a lower rate of complications at a higher rate of consolidation. Conclusions Our study showed that the ‘diamond concept’ is a suitable method for safely and effectively treating non-unions with large defects or infections. The use of an antibiotic-coated nail provides a therapeutic benefit. For large bone defects of infected non-unions the two-step procedure after Masquelet is an efficient way to eradicate the infection and treat the bone defect successfully.
