Kai Mithoefer

Clinical Efficacy of the Microfracture Technique for Articular Cartilage Repair in the Knee An Evidence-Based Systematic Analysis

Background Despite the popularity of microfracture as a first-line treatment for articular cartilage defects in the knee, systematic information on its clinical efficacy for articular cartilage repair and long-term improvement of knee function is not available. Hypothesis Systematic analysis of the existing clinical literature of microfracture in the knee can improve the understanding of the advantages and limitations of this cartilage repair technique and can help to optimize its indications and clinical outcomes. Study Design Systematic review. Methods A comprehensive literature search was performed using established search engines (MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials) to identify original human studies of articular cartilage repair with microfracture. Modified Coleman Methodology Scores were used to analyze the quality of the existing studies. Clinical efficacy of articular cartilage repair was evaluated by systematic analysis of short- and long-term functional outcome scores, macroscopic and microscopic repair cartilage quality, and findings of postoperative magnetic resonance imaging. Results Twenty-eight studies describing 3122 patients were included in the review. The average follow-up was 41 months, with only 5 studies reporting follow-up of 5 years or more. Six studies were randomized controlled trials and the mean Coleman Methodology Score was 58 (range, 22–97). Microfracture effectively improved knee function in all studies during the first 24 months after microfracture, but the reports on durability of the initial functional improvement were conflicting. Several factors were identified that affected clinical outcome. Defect fill on magnetic resonance imaging was highly variable and correlated with functional outcome. Macroscopic repair cartilage quality positively affected long-term failure rate, while the influence of histologic repair tissue quality remained inconclusive. Conclusion This systematic analysis shows that microfracture provides effective short-term functional improvement of knee function but insufficient data are available on its long-term results. Shortcomings of the technique include limited hyaline repair tissue, variable repair cartilage volume, and possible functional deterioration. The quality of the currently available data on micro-fracture is still limited by the variability of results and study designs. Further well-designed studies are needed to determine the long-term efficacy of microfracture and to define its specific clinical indications compared to other cartilage repair techniques.

High-Impact Athletics After Knee Articular Cartilage Repair A Prospective Evaluation of the Microfracture Technique

Background Knee articular cartilage injuries in athletes present a therapeutic challenge and have been identified as an important cause of permanent disability because of the high mechanical joint stresses in athletes. Purpose To determine whether microfracture treatment of knee articular cartilage injuries can return athletes to high-impact sports and to identify the factors that affect the ability to return to athletic activity. Study Design Case series; Level of evidence, 4. Methods Thirty-two athletes who regularly participated in high-impact, pivoting sports before articular cartilage injury were treated with microfracture for single articular cartilage lesions of the knee. Functional outcome was prospectively evaluated with a minimum 2-year follow-up by subjective rating, activity-based outcome scores, and the ability for postoperative participation in high-impact, pivoting sports. Results At last follow-up, 66% of athletes reported good or excellent results. Activity of daily living, Marx activity rating scale, and Tegner activity scores increased significantly after microfracture. After an initial improvement, score decreases were observed in 47% of athletes. Forty-four percent of athletes were able to regularly participate in high-impact, pivoting sports, 57% of these at the preoperative level. Return to high-impact sports was significantly higher in athletes with age <40 years, lesion size <200 mm2, preoperative symptoms <12 months, and no prior surgical intervention. Conclusion Microfracture is an effective first-line treatment to return young athletes with short symptomatic intervals and small articular cartilage lesions of the knee back to high-impact athletics.

Terminology and classification of muscle injuries in sport: The Munich consensus statement

Objective To provide a clear terminology and classification of muscle injuries in order to facilitate effective communication among medical practitioners and development of systematic treatment strategies. Methods Thirty native English-speaking scientists and team doctors of national and first division professional sports teams were asked to complete a questionnaire on muscle injuries to evaluate the currently used terminology of athletic muscle injury. In addition, a consensus meeting of international sports medicine experts was established to develop practical and scientific definitions of muscle injuries as well as a new and comprehensive classification system. Results The response rate of the survey was 63%. The responses confirmed the marked variability in the use of the terminology relating to muscle injury, with the most obvious inconsistencies for the term strain. In the consensus meeting, practical and systematic terms were defined and established. In addition, a new comprehensive classification system was developed, which differentiates between four types: functional muscle disorders (type 1: overexertion-related and type 2: neuromuscular muscle disorders) describing disorders without macroscopic evidence of fibre tear and structural muscle injuries (type 3: partial tears and type 4: (sub)total tears/tendinous avulsions) with macroscopic evidence of fibre tear, that is, structural damage. Subclassifications are presented for each type. Conclusions A consistent English terminology as well as a comprehensive classification system for athletic muscle injuries which is proven in the daily practice are presented. This will help to improve clarity of communication for diagnostic and therapeutic purposes and can serve as the basis for future comparative studies to address the continued lack of systematic information on muscle injuries in the literature. What are the new things Consensus definitions of the terminology which is used in the field of muscle injuries as well as a new comprehensive classification system which clearly defines types of athletic muscle injuries. Level of evidence Expert opinion, Level V.

Return to Sports Participation After Articular Cartilage Repair in the Knee: Scientific Evidence

Background Articular cartilage injury in the athletes knee presents a difficult clinical challenge. Despite the importance of returning injured athletes to sports, information is limited on whether full sports participation can be successfully achieved after articular cartilage repair in the knee. Hypothesis Systematic analysis of athletic participation after articular cartilage repair will demonstrate the efficacy of joint surface restoration in high-demand patients and help to optimize outcomes in athletes with articular cartilage injury of the knee. Study Design Systematic review. Methods A comprehensive literature review of original studies was performed to provide information about athletic participation after articular cartilage repair. The athletes ability to perform sports postoperatively was assessed by activity outcome scores, rate of return to sport, timing of the return, level of postoperative sports participation, and the continuation of athletic activity over time. Results Twenty studies describing 1363 patients were included in the review, with an average follow-up of 42 months. Return to sports was possible in 73% overall, with highest return rates after osteochondral autograft transplantation. Time to return to sports varied between 7 and 18 months, depending on the cartilage repair technique. Initial return to sports at the preinjury level was possible in 68% and did not significantly vary between surgical techniques. Continued sports participation at the preinjury level was possible in 65%, with the best durability after autologous chondrocyte transplantation. Several factors affected the ability to return to sport: athletes age, preoperative duration of symptoms, level of play, lesion size, and repair tissue morphology. Conclusion Articular cartilage repair in the athletic population allows for a high rate of return to sports, often at the preinjury level. Return to sports participation is influenced by several independent factors. The findings provide pertinent information that is helpful for the clinical decision-making process and for the management of the athletes postoperative expectations.

Chondral Resurfacing of articular cartilage defects in the knee with the Microfracture Technique Surgical technique

BACKGROUND Microfracture is a frequently used technique for the repair of articular cartilage lesions of the knee. Despite the popularity of the technique, prospective information about the clinical results after microfracture is still limited. The purpose of our study was to identify the factors that affect the clinical outcome from this cartilage repair technique. METHODS Forty-eight symptomatic patients with isolated full-thickness articular cartilage defects of the femur in a stable knee were treated with the microfracture technique. Prospective evaluation of patient outcome was performed for a minimum follow-up of twenty-four months with a combination of validated outcome scores, subjective clinical rating, and cartilage-sensitive magnetic resonance imaging. RESULTS At the time of the latest follow-up, knee function was rated good to excellent for thirty-two patients (67%), fair for twelve patients (25%), and poor for four (8%). Significant increases in the activities of daily living scores, International Knee Documentation Committee scores, and the physical component score of the Short Form-36 were demonstrated after microfracture (p < 0.05). A lower body-mass index correlated with higher scores for the activities of daily living and SF-36 physical component, with the worst results for patients with a body-mass index of >30 kg/m(2). Significant improvement in the activities of daily living score was more frequent with a preoperative duration of symptoms of less than twelve months (p < 0.05). Magnetic resonance imaging in twenty-four knees demonstrated good repair-tissue fill in the defect in thirteen patients (54%), moderate fill in seven (29%), and poor fill in four patients (17%). The fill grade correlated with the knee function scores. All knees with good fill demonstrated improved knee function, whereas poor fill grade was associated with limited improvement and decreasing functional scores after twenty-four months. CONCLUSIONS Microfracture repair of articular cartilage lesions in the knee results in significant functional improvement at a minimum follow-up of two years. The best short-term results are observed with good fill grade, low body-mass index, and a short duration of preoperative symptoms. A high body-mass index adversely affects short-term outcome, and a poor fill grade is associated with limited short-term durability.

Functional Outcome After Acute Compartment Syndrome of the Thigh

BACKGROUND Acute compartment syndrome of the thigh is an uncommon condition that is associated with a high rate of morbidity. Because of its rarity, limited information is available on the long-term functional outcome for patients with this condition and the factors that affect the clinical result. METHODS Eighteen patients with acute compartment syndrome of the thigh were evaluated at an average of sixty-two months after treatment. Functional outcome was evaluated by means of physical examination, isokinetic thigh-muscle testing, and validated functional outcome scores. RESULTS Long-term functional deficits were present in eight patients, and only five patients had full recovery of thigh-muscle strength. The persistent dysfunction was reflected in worse overall functional outcome scores. High injury severity scores, ipsilateral femoral fracture, prolonged intervals to decompression, the presence of myonecrosis at the time of fasciotomy, and an age of more than thirty years were associated with increased long-term functional deficits, persistent thigh-muscle weakness, and worse functional outcome scores. CONCLUSIONS Acute compartment syndrome of the thigh is often associated with considerable long-term morbidity. Several factors can affect the functional outcome, and knowledge of these factors can help in the development of a more effective clinical management strategy to reduce long-term morbidity.

Current Concepts for Rehabilitation and Return to Sport After Knee Articular Cartilage Repair in the Athlete

Articular cartilage injury is observed with increasing frequency in both elite and amateur athletes and results from the significant acute and chronic joint stress associated with impact sports. Left untreated, articular cartilage defects can lead to chronic joint degeneration and athletic and functional disability. Treatment of articular cartilage defects in the athletic population presents a therapeutic challenge due to the high mechanical demands of athletic activity. Several articular cartilage repair techniques have been shown to successfully restore articular cartilage surfaces and allow athletes to return to high-impact sports. Postoperative rehabilitation is a critical component of the treatment process for athletic articular cartilage injury and should take into consideration the biology of the cartilage repair technique, cartilage defect characteristics, and each athletes sport-specific demands to optimize functional outcome. Systematic, stepwise rehabilitation with criteria-based progression is recommended for an individualized rehabilitation of each athlete not only to achieve initial return to sport at the preinjury level but also to continue sports participation and reduce risk for reinjury or joint degeneration under the high mechanical demands of athletic activity.

Emerging Options for Treatment of Articular Cartilage Injury in the Athlete

Articular cartilage injury is observed with increasing frequency in both elite and amateur athletes and results from the significant joint stress associated particularly with high-impact sports. The lack of spontaneous healing of these joint surface defects leads to progressive joint pain and mechanical symptoms with resulting functional impairment and limitation of athletic participation. Left untreated, articular cartilage defects can lead to chronic joint degeneration and athletic disability. Articular cartilage repair in athletes requires effective and durable joint surface restoration that can withstand the significant joint stresses generated during athletic activity. Several techniques for articular cartilage repair have been developed recently, which can successfully restore articular cartilage surfaces and allow for return to high-impact athletics after articular cartilage injury. Besides these existing techniques, new promising scientific concepts and techniques are emerging that incorporate modern tissue engineering technologies and promise further improvement for the treatment of these challenging injuries in the demanding athletic population.

Return to play after thigh muscle injury in elite football players: implementation and validation of the Munich muscle injury classification

Background Owing to the complexity and heterogeneity of muscle injuries, a generally accepted classification system is still lacking. Aims To prospectively implement and validate a novel muscle injury classification and to evaluate its predictive value for return to professional football. Methods The recently described Munich muscle injury classification was prospectively evaluated in 31 European professional male football teams during the 2011/2012 season. Thigh muscle injury types were recorded by team medical staff and correlated to individual player exposure and resultant time-loss. Results In total, 393 thigh muscle injuries occurred. The muscle classification system was well received with a 100% response rate. Two-thirds of thigh muscle injuries were classified as structural and were associated with longer lay-off times compared to functional muscle disorders (p<0.001). Significant differences were observed between structural injury subgroups (minor partial, moderate partial and complete injuries) with increasing lay-off time associated with more severe structural injury. Median lay-off time of functional disorders was 5–8 days without significant differences between subgroups. There was no significant difference in the absence time between anterior and posterior thigh injuries. Conclusions The Munich muscle classification demonstrates a positive prognostic validity for return to play after thigh muscle injury in professional male football players. Structural injuries are associated with longer average lay-off times than functional muscle disorders. Subclassification of structural injuries correlates with return to play, while subgrouping of functional disorders shows less prognostic relevance. Functional disorders are often underestimated clinically and require further systematic study.

Guidelines for the Design and Conduct of Clinical Studies in Knee Articular Cartilage Repair: International Cartilage Repair Society Recommendations Based on Current Scientific Evidence and Standards of Clinical Care

Objective: To summarize current clinical research practice and develop methodological standards for objective scientific evaluation of knee cartilage repair procedures and products. Design: A comprehensive literature review was performed of high-level original studies providing information relevant for the design of clinical studies on articular cartilage repair in the knee. Analysis of cartilage repair publications and synopses of ongoing trials were used to identify important criteria for the design, reporting, and interpretation of studies in this field. Results: Current literature reflects the methodological limitations of the scientific evidence available for articular cartilage repair. However, clinical trial databases of ongoing trials document a trend suggesting improved study designs and clinical evaluation methodology. Based on the current scientific information and standards of clinical care, detailed methodological recommendations were developed for the statistical study design, patient recruitment, control group considerations, study endpoint definition, documentation of results, use of validated patient-reported outcome instruments, and inclusion and exclusion criteria for the design and conduct of scientifically sound cartilage repair study protocols. A consensus statement among the International Cartilage Repair Society (ICRS) and contributing authors experienced in clinical trial design and implementation was achieved. Conclusions: High-quality clinical research methodology is critical for the optimal evaluation of current and new cartilage repair technologies. In addition to generally applicable principles for orthopedic study design, specific criteria and considerations apply to cartilage repair studies. Systematic application of these criteria and considerations can facilitate study designs that are scientifically rigorous, ethical, practical, and appropriate for the question(s) being addressed in any given cartilage repair research project.