Return to sports participation after articular cartilage repair in the knee: scientific evidence

Return to Sports After Bone Marrow-Derived Cell Transplantation for Osteochondral Lesions of the Talus

OBJECTIVE

Arthroscopic "one-step" technique based on bone marrow-derived cell transplantation (BMDCT) have achieved good results in repairing osteochondral lesions of the talus (OLT), overcoming important drawbacks of older techniques. It may be particularly adequate for the treatment of athletes in order to permit a safe and stable return to sports. The aim of this study was to report the results at 48 months of a series of athletes and the factors influencing the return to sports.

DESIGN

Case series. A total of 140 athletes underwent a "one-step" BMDCT repair of OLT. All the patients had the cells harvested from the iliac crest, condensed and loaded on a scaffold, and then implanted. Patients were evaluated clinically by the American Orthopaedic Foot and Ankle Society (AOFAS) scores and Halasi score.

RESULTS

AOFAS score improved from 58.7 ± 13.5 preoperatively to 90.6 ± 8.6 (P < 0.005) at 24 months, and to 90.9 ± 10.7 at 48 months. Halasi score was 6.88 ± 1.8 preinjury, 4.08 ± 1.7 preoperatively, and 5.56 ± 2.0 at final follow-up. At the final follow-up, all the patients (beside 1 failure and 3 lost) were able to return to activity and 72.8% were able to resume sports at preinjury level.

CONCLUSIONS

"One-step" BMDCT repair of OLT had good clinical results that was durable over time in athletes, permitting a return to sports at preinjury level in the majority of patients. The preoperative presence of impingement and articular degeneration were the main negative prognostic factors.

Aarhus Regenerative Orthopaedics Symposium (AROS)

The combination of modern interventional and preventive medicine has led to an epidemic of ageing. While this phenomenon is a positive consequence of an improved lifestyle and achievements in a society, the longer life expectancy is often accompanied by decline in quality of life due to musculoskeletal pain and disability. The Aarhus Regenerative Orthopaedics Symposium (AROS) 2015 was motivated by the need to address regenerative challenges in an ageing population by engaging clinicians, basic scientists, and engineers. In this position paper, we review our contemporary understanding of societal, patient-related, and basic science-related challenges in order to provide a reasoned roadmap for the future to deal with this compelling and urgent healthcare problem.

Comparison of T2* relaxation times of articular cartilage of the knee in elite professional football players and age-and BMI-matched amateur athletes

OBJECTIVE

Recent investigation has underlined the potential of quantitative MR imaging to be used as a complementary tool for the diagnosis of cartilage degeneration at an early state. The presented study analyses T2* relaxation times of articular cartilage of the knee in professional athletes and compares the results to age- and BMI (Body Mass Index)-matched healthy amateur athletes.

MATERIALS AND METHODS

22 professional football players and 22 age- and BMI-matched individuals were underwent knee Magnetic Resonance Imaging (MRI) at 3T including qualitative and quantitative analysis. Qualitative analysis included e.g. meniscal tears, joint effusion and bone edema. For quantitative analysis T2* (22 ET: 4.6-53.6ms) measurements in 3D data acquisition were performed. Deep and superficial layers of 22 predefined cartilage segments were analysed. All data sets were postprocessed using a dedicated software tool. Statistical analysis included Student t-test, confidence intervals and a random effects model.

RESULTS

In both groups, T2* relaxation times were significantly higher in the superficial compared to the deep layers (p<0.001). Professional athletes had significantly higher relaxation times in eight superficial and three deep cartilage layers in the predefined cartilage segments (p<0.05). Highly significant differences were found in the weight-bearing segments of the lateral superficial femoral condyle (p<0.001).

CONCLUSION

Elevated T2* values in cartilage layers of professional football players compared to amateur athletes were noted. The effects seem to predominate in superficial cartilage layers.

Comprehensiveness of Outcome Reporting in Studies of Articular Cartilage Defects of the Knee

PURPOSE

To assess the comprehensiveness of outcome reporting after treatment of focal articular cartilage defects in the knee.

METHODS

A systematic review of literature published over the past 5 years (October 2010 to October 2015) in 5 high-impact orthopaedic journals was completed to identify all recent clinical studies tracking outcomes after surgery for focal articular cartilage defects in the knee. A metric reporting score was calculated for each study, according to reporting of 6 cardinal domains: pain, satisfaction, osteoarthritis progression, subjective knee function, objective knee function, and patient-reported outcomes.

RESULTS

Of the 122 studies included for review, 117 (96%) tracked patient-reported outcomes during follow-up. Nearly two-thirds of studies (63%) monitored progression of osteoarthritis at follow-up. Fewer than half of studies (39%) specifically monitored pain outcomes in patients. One-third of studies (30%) tracked patient satisfaction. Only 21% of studies monitored subjective knee function using proxies such as return to play, and only 17% of studies reported on objective knee function during return visits to the clinic. The average metric reporting score of all studies was 2.6, and nearly half of studies (48%) reported on only 1 or 2 domains of interest.

CONCLUSIONS

There is substantial variability in outcome reporting after cartilage surgery in high-impact orthopaedic journals. Furthermore, most studies do not comprehensively track outcomes across domains. Both factors hinder comparison of results across studies. Future outcome metrics should focus on patient-centered factors to improve both accuracy of results reporting and standardization across studies.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Osteochondral Autograft Transfer Versus Microfracture in the Knee: A Meta-analysis of Prospective Comparative Studies at Midterm

PURPOSE

To compare microfracture (MFX) and osteochondral autograft transfer (OAT) surgical techniques to determine (1) postoperative activity level, (2) subjective patient outcomes, (3) failure rates, and (4) assess if any lesion characteristics favored one technique over the other.

METHODS

A comprehensive review of literature was performed of all studies comparing MFX and OAT. Studies included were all prospective studies that reported on activity-based outcome measures such as Tegner activity scores and subjective outcomes such as the International Knee Documentation Committee score. Failure rates, as determined by the publishing authors, were recorded for each study. Meta-analyses were conducted using a random-effects model. Paired standardized mean differences (Hedges's g to account for small sample bias) were used for continuous outcome measures, and risk ratios (Mantel-Haenszel method for small sample bias) for dichotomous outcome measures.

RESULTS

Six prospective studies satisfied the eligibility criteria and included 249 patients (186 male, 120 female) with an average age of 26.4 years and follow-up of 67.2 months. Tegner scores were superior in patients treated with OAT compared with MFX (ΔOAT-MFX for pre-post scores = 0.94 Tegner points, standardized mean difference [SMD] = 0.469, P = .005). Failure rates of MFX were higher than OAT (OAT = 11%, MFX = 32%, risk ratio = 2.42, P < .036). OAT was superior to MFX at 3 years in relation to subjective outcome scores (SMD = 0.404, P = .008). When assessing OAT lesions larger than 3 cm², OAT was superior to MFX with respect to activity level (SMD = 0.506, P = .001).

CONCLUSIONS

OAT may achieve higher activity levels and lower risk of failure when compared with MFX for cartilage lesions greater than 3 cm² in the knee, although there was no significant difference for lesions less than 3 cm² at midterm. However, because of variability in patient-specific factors such as age, preinjury activity level, lesion location and size, the superiority of OAT over MFX cannot be generalized to all patient populations and therefore requires individualized patient care.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II studies.

Cartilage repair strategies in the knee: A survey of Turkish surgeons

Objectives

The purpose of this study was to analyze the trends in cartilage repair strategies among Turkish orthopedic surgeons for isolated focal (osteo)chondral lesions of the knee joint.

Materials and methods

A web-based survey of 21 questions consisting of surgical indications, techniques and time to return to sports was developed to investigate the preferences of members of the TOTBID and the TUSYAD.

Results

A total of 147 surgeons answered the questionnaire.70% of the respondents were TUSYAD members. 82% of respondents had at least five years experience in arthroscopy. Half of the surgeons indicated that patient age of 50 was the upper limit for cartilage repair. Irrespective of activity level, microfracture (60–67%) was the most frequently used technique for lesions smaller 2.5 cm². In lesions larger than 4 cm², MACI was the most commonly advocated procedure (67%). In patients with high activity levels, mosaicplasty was the first choice (69%) for lesions between 2.5 and 4 cm² in size, followed by MACI (27%).

Conclusion

Patient age, activity level, BMI and lesion size were important determinants for the choice of treatment of isolated chondral lesions in the knee. These results reflect the choices of experienced knee surgeons in the country. Although not widely performed in Turkey and has limited reimbursement by the health care system, the first choice for defects over 4 cm² was second generation ACI. Third party payers & health reimbursement authorities should take into account that large defects require methods which are relatively expensive and need high technology. Cross-sectional survey, Level II.

Sports Activity After Reconstruction of Osteochondral Lesions of the Talus With Autologous Spongiosa Grafts and Autologous Matrix-Induced Chondrogenesis

BACKGROUND

For the treatment of osteochondral lesions of the talus (OCLTs), autologous matrix-induced chondrogenesis (AMIC) is a safe 1-step procedure with good clinical and radiological results. However, data regarding postoperative sports activity after AMIC are limited.

PURPOSE

To identify significant factors influencing the rate of postoperative sports and recreational activities.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The sports and recreational activities of 60 patients (mean age, 34.9 ± 11.5 years) undergoing the AMIC procedure were retrospectively analyzed at a mean of 46.9 ± 17.8 months (range, 24.5-87.0 months) postoperatively. The visual analog scale (VAS) for pain score, Tegner activity scale score, activity rating scale (ARS) score, and satisfaction with surgery outcomes were assessed.

RESULTS

Corrective calcaneal osteotomy was performed in 38 of 60 (63.3%) patients. Ligament repair was performed in 41 of 60 (68.3%) patients. The mean VAS score improved significantly from 6.9 ± 1.6 points (range, 5-10 points) preoperatively to 2.3 ± 1.9 points (range, 0-6 points) at latest follow-up (P < .001). No significant change in the mean Tegner activity scale score (3.3 ± 2.0 preoperatively to 3.4 ± 2.2 postoperatively; P = .526) and the mean ARS score (2.6 ± 4.3 preoperatively to 2.3 ± 3.4 postoperatively; P = .874) was noted. The percentage of patients involved in sports activity before the onset of symptoms became significantly lower at the time of surgery (from 95.0% to 53.3%; P < .001); no significant difference was noted postoperatively (from 53.3% to 58.3%; P = .663). No significant difference of the weekly sports frequency and the duration of sports activity was found postoperatively.

CONCLUSION

Patients undergoing AMIC repair of an OCLT participate at a similar low postoperative sports and recreational activity level compared with the preoperative level.

Long-Term Outcomes after Autologous Chondrocyte Implantation: A Systematic Review at Mean Follow-Up of 11.4 Years

OBJECTIVE

Autologous chondrocyte implantation (ACI) has not been proven to be durable over the long-term. The purpose of this systematic review was (1) to evaluate activity level and knee function, (2) to evaluate reoperation and failure rates, and (3) to analyze risk factors for reoperation and failure of ACI at minimum long-term follow-up.

DESIGN

A comprehensive review was performed for studies with long-term outcomes after ACI for cartilage defect repair. Studies reported outcome scores such as Tegner score, Lysholm score, and International Knee Documentation Society (IKDC) score along with rates of failure and reoperation. Modified Coleman Methodology Scores were calculated to assess study methodological quality.

RESULTS

Nine studies with a total of 771 patients with a mean age of 33.4 ± 2.5 years, mean defect size of 5.9 ± 1.6 cm(2), and mean follow-up of 11.4 years were included. Tegner score, Lysholm score, and IKDC score change from preoperative to final follow-up was 1.1 (95% CI 0.8-1.4, P < 0.001), 24.9 points (95% CI 18.8-31, P < 0.001), and 16.5 points (95% CI 5.4-27.5, P < 0.01), respectively. The mean failure and reoperation rates were 18% and 37%, respectively. Increased age and lesion size (>4.5 cm(2)) were significantly correlated with increased risk of reoperation and failure.

CONCLUSIONS

Overall, ACI demonstrated successful outcomes in 82% of patients over the long-term. Increased patient age and lesion size greater than 4.5 cm(2) were risk factors for a higher reoperation and failure rate. Nonetheless, this review is limited by heterogeneity in surgical technique, and lesion and patient characteristics.

Prevalence of Articular Cartilage Lesions and Surgical Clinical Outcomes in Football (Soccer) Players' Knees: A Systematic Review

PURPOSE

To systematize the available scientific literature on the prevalence of articular cartilage and/or osteochondral lesions in football (soccer) players' knees, and overview the surgical procedures and functional outcomes and return to sports.

METHODS

A comprehensive search using Pubmed, Cochrane Library, SPORTDiscus, and CINAHL databases was carried out until September 30, 2015. All English language studies that assessed the outcomes of a surgical technique for the treatment of articular cartilage lesions in football players' knees, with a minimum follow-up of 12 months, were included. The reference list of the most relevant papers was screened. The main outcomes of interest were the clinical, arthroscopy or imaging primary outcomes and the return to sports rate. The methodological and reporting qualities were assessed according to Coleman methodology score.

RESULTS

The search provided 485 titles and abstracts. Five studies were eligible for inclusion (mean Coleman score of 37.2 points), comprising a total of 183 football players with a mean age of 25.7 years. A total of 217 articular cartilage and/or osteochondral lesions were reported, where the medial and lateral femoral condyles were the most common sites of lesion. The surgical procedures investigated were mosaicplasty, microfracture, autologous chondrocyte implantation, and chondral debridement.

CONCLUSIONS

No definitive conclusion could be made in respect to the best current surgical technique for articular cartilage and osteochondral lesions. Microfracture and mosaicplasty can provide a faster return to competition and faster clinical and functional results, whereas autologous chondrocyte implantation and/or matrix-induced autologous chondrocytes implantation procedures can enhance longstanding clinical and functional results.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Muscle co-contraction during gait in individuals with articular cartilage defects in the knee

Increased muscle co-contraction during gait is common in individuals with knee pathology, and worrisome as it is known to amplify tibiofemoral compressive forces. While knees with articular cartilage defects (ACD) are more vulnerable to compressive forces, muscle co-contraction has never been reported in this population. The purpose of this study was to evaluate the extent to which individuals with ACDs in the knee demonstrate elevated quadriceps to hamstrings muscle co-contraction on the involved limb during gait compared to the uninvolved limb and to healthy controls. We also explored the impact of participant characteristics and knee impairments on co-contraction. Twenty-nine individuals with full-thickness knee ACDs (ACD group) and 19 healthy adults (control group) participated in this study. Participants performed five gait trials at self-selected speed, during which activity of the quadriceps and hamstrings muscles were collected with surface electromyography. Three-dimensional motion capture was used to define phases of gait. Quadriceps strength and self-reported outcomes were also assessed in the same session. There were no differences in quadriceps: hamstrings co-contraction between the ACD and control groups, or between the involved and uninvolved limb for the ACD group. For both ACD and control groups, co-contraction was highest in early stance and lowest in late stance. Quadriceps strength was consistently the strongest predictor of muscle co-contraction in both the ACD and the control groups, with individuals with lower strength demonstrating greater co-contraction. Further study is needed to understand the effect of increased muscle co-contraction on joint compressive forces in the presence of varied quadriceps strength.

Cartilage repair surgery for full-thickness defects of the knee in Germany: indications and epidemiological data from the German Cartilage Registry (KnorpelRegister DGOU)

PURPOSE

Treatment of cartilage defects of the knee remains an important issue with high relevance. In October 2013 the German Cartilage Registry (KnorpelRegister DGOU) was initiated in order to study indications, epidemiology and (clinical) outcome of different cartilage repair techniques. The present evaluation of the registry baseline data was initiated to report common practices of cartilage repair surgery in Germany.

MATERIALS AND METHODS

1065 consecutive patients who underwent surgical cartilage treatment of the knee have been included (complete data sets available in 1027 cases; FU rate 96.4 %) between October 1, 2013 and June 30, 2015. Data collection was performed using a web-based RDE System. All data were provided by the attending physician at the time of arthroscopic or open surgery of the affected knee.

RESULTS

In 1027 cartilage repair procedures, single defects were treated in 80 % of the cases with the majority of the defects located on the medial femoral condyle, followed by the patella. Degenerative defects grade III or IV according to ICRS were treated in 60 % of the cases and therefore were found more frequently compared to traumatic or post-traumatic lesions. Autologous chondrocyte implantation (ACI) was the most common technique followed by bone marrow stimulation (BMS) and osteochondral transplantation (OCT). While ACI was performed in defects with a mean size of 4.11 cm(2) SD SD 2.16), BMS and OCT (1.51 cm(2), SD 1.19; p < 0.01) were applied in significantly smaller defects (both p < 0.01). Independent of defect size, the ratio of ACI versus BMS applications differed between different defect locations. ACI was used preferably in defects located on the patella.

CONCLUSION

The present analysis of data from the German Cartilage Registry shows that the vast majority of cartilage repair procedures were applied in degenerative, non-traumatic cartilage defects. Experts in Germany seem to follow the national and international guidelines in terms that bone marrow stimulation is applied in smaller cartilage defects while cell-based therapies are used for the treatment of larger cartilage defects. In patellar cartilage defects a trend towards the use of cell-based therapies has been observed.

Sport and early osteoarthritis: the role of sport in aetiology, progression and treatment of knee osteoarthritis

Sports activities are considered favourable for general health; nevertheless, a possible influence of sports practice on the development of early osteoarthritis (OA) is a cause for concern. A higher incidence of OA in knees and ankles of former high-impact sports players than in those of the normal population has been shown and it is still debatable whether the cause is either to be recognized generically in the higher number of injuries or in a joint overload. The possibility to address knee OA in its early phases may be strictly connected to the modification of specific extrinsic or intrinsic factors, related to the patient in order to save the joint from further disease progression; these include sport practice, equipment and load. Non-surgical therapies such as continuative muscles reinforce and training play a strong role in the care of athletes with early OA, particularly if professional. There is an overall agreement on the need of an early restoring of a proper meniscal, ligament and cartilage integrity in order to protect the knee and resume sports safely, whereas alignment is a point still strongly debatable especially for professional athletes. Remaining questions still to be answered are the risks of different sports in relation to one another, although an actual protective effect of low-impact sports, such as walking, swimming or cycling, has been recognized on the appearance or worsening of OA, the effect of continuing or ceasing to practice a sport on the natural history of early OA, and even following appropriate treatment is still unknown.

Autologous chondrocyte implantation (ACI) for cartilage defects of the knee: A guideline by the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU)

BACKGROUND

Autologous chondrocyte implantation (ACI) is an established and well-accepted procedure for the treatment of localised full-thickness cartilage defects of the knee.

METHODS

The present review of the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU) describes the biology and function of healthy articular cartilage, the present state of knowledge concerning therapeutic consequences of primary cartilage lesions and the suitable indication for ACI.

RESULTS

Based on best available scientific evidence, an indication for ACI is given for symptomatic cartilage defects starting from defect sizes of more than three to four square centimetres; in the case of young and active sports patients at 2.5cm(2), while advanced degenerative joint disease needs to be considered as the most important contraindication.

CONCLUSION

The present review gives a concise overview on important scientific background and the results of clinical studies and discusses the advantages and disadvantages of ACI.

LEVEL OF EVIDENCE

Non-systematic Review.

Management of knee articular cartilage injuries in athletes: chondroprotection, chondrofacilitation, and resurfacing

Articular cartilage defects of the knee are common among athletes where the physical demands of sport result in significant stresses on joints. Chondral defects are associated with pain and functional impairment that limit sporting participation and may progress to joint degeneration and frank arthritis. Management of established chondral lesions aims to allow athletes to return to high-impact sports and can be considered in terms of protection of existing cartilage, chondrofacilitation, and resurfacing. Repaired and regenerated cartilage must closely resemble and function like normal hyaline cartilage, and this ability may be the most significant factor for the return to sport. Based on our experiences and the available literature, we outline how athletes can best protect their cartilage, how physicians can facilitate intrinsic repair of established lesions, and which methods of cartilage restoration or resurfacing should be used in different situations.

LEVEL OF EVIDENCE

IV.

Can young and active patients participate in sports after osteochondral autologous transfer combined with valgus high tibial osteotomy?

PURPOSE

To evaluate sporting activity following osteochondral autologous transfer (OAT) combined with valgus high tibial osteotomy (HTO) in young and active patients with focal osteochondral defects of the medial femoral condyle and concomitant varus malalignment.

METHODS

Thirty patients with focal osteochondral defects of the medial femoral condyle and varus malalignment >2° were enrolled. All patients were active in sports on a regular base prior to surgery (lifetime), but were unable to perform sports at the time of surgery. Sporting activity 1 year preoperatively and at final follow-up was compared using a previously published sports questionnaire, which assesses sports level, number of sports disciplines, sports frequency, sports duration and the participation in 32 common sports disciplines. Additionally, the Tegner activity scale and the Activity Rating Scale were used.

RESULTS

After a mean follow-up of 6.9 years (2.5-9.8; SD 2.4), 76.7 % of patients were participating in sports on a regular basis (Fig. 2). Compared to 1 year preoperatively, there was no difference (n.s.) with regard to sports, the number of sports disciplines, sports frequency and sports duration (Fig. 4). The median Tegner activity scale measured preoperatively 5.0 (2.0-7.0) and post-operatively 5.0 (4.0-7.0) points (Fig. 3), and the ARS changed from 5.7 to 5.3 points (n.s.). The different types of sports disciplines were comparable between 1 year preoperatively and at follow-up.

CONCLUSION

A high return to sports rate and an activity level comparable to the state at 1 year preoperatively can be expected in young and active patients after combined OAT and valgus HTO. This seems to be relevant in clinical practice when planning, indicating and performing these complex procedures.

LEVEL OF EVIDENCE

IV.

Return to Sport After Articular Cartilage Repair in Athletes' Knees: A Systematic Review

PURPOSE

To perform a systematic review of cartilage repair in athletes' knees to (1) determine which (if any) of the most commonly implemented surgical techniques help athletes return to competition, (2) identify which patient- or defect-specific characteristics significantly affect return to sport, and (3) evaluate the methodologic quality of available literature.

METHODS

A systematic review of multiple databases was performed. Return to preinjury level of sport was defined as the ability to play in the same or greater level (i.e., league or division) of competition after surgery. Study methodologic quality for all studies analyzed in this review was evaluated with the Coleman Methodology Score.

RESULTS

Systematic review of 1,278 abstracts identified 20 level I-IV studies for inclusion but only 1 randomized controlled trial. Twenty studies (1,117 subjects) were included. Subjects (n = 970) underwent 1 of 4 surgeries (microfracture [n = 529], autologous chondrocyte implantation [ACI, n = 259], osteochondral autograft [n = 139], or osteochondral allograft [n = 43]), and 147 were control patients. The rate of return to sports was greatest after osteochondral autograft transplantation (89%) followed by osteochondral allograft, ACI, and microfracture (88%, 84%, and 75%, respectively). Osteochondral autograft transplantation and ACI had statistically significantly greater rates of return to sports compared with microfracture (P < .001, P < .01; Fisher exact test).

CONCLUSIONS

Athletes may return to sports participation after microfracture, ACI, osteochondral autograft, or osteochondral allograft, but microfracture patients were least likely to return to sports. The athletes who had a better prognosis after surgery were younger, had a shorter preoperative duration of symptoms, underwent no previous surgical interventions, participated in a more rigorous rehabilitation protocol, and had smaller cartilage defects.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Autologous osteochondral transplantation for osteochondral lesions of the talus in an athletic population

PURPOSE

To assess clinical outcomes and return to sport in an athletic population treated with autologous osteochondral transplantation (AOT) for osteochondral lesions of the talus.

METHODS

A total of 36 patients were included in this retrospective study including 21 professional athletes and 15 amateur athletes who participated in regular moderate- or high-impact athletic activity. All patients underwent autologous osteochondral transplantation of the talus under the care of a single surgeon. At a mean follow-up of 5.9 years, patients were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system. All patients also received pre-operative MRI with the follow-up MRI performed at 1 year and underwent assessment of return to athletic activity.

RESULTS

The overall AOFAS score improved from 65.5 (SD ± 11.1) to 89.4 (SD ± 14.4) (p = 0.01). At a final follow-up, 90% of professional athletes (19 of 21) were still competing in athletic activity or still able to participate in unrestricted activity. Of the recreational athletes, 87% (13 of 15) had full return to pre-injury activity levels, while two (13%) returned to activity with restrictions or reduced intensity. MRI showed cystic change in 33% of patients post-operatively; however, this did not appear to affect outcomes (n.s.). Donor site symptoms were seen in 11% of the cohort at final follow-up, despite high function at donor knee.

CONCLUSION

The results of our study indicate that AOT procedure is able to achieve good outcomes in an athletic population at a midterm follow-up.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Running speed increases plantar load more than per cent body weight on an AlterG® treadmill

AlterG® treadmills allow for running at different speeds as well as at reduced bodyweight (BW), and are used during rehabilitation to reduce the impact load. The aim of this study was to quantify plantar loads borne by the athlete during rehabilitation. Twenty trained male participants ran on the AlterG® treadmill in 36 conditions: all combinations of indicated BW (50-100%) paired with different walking and running speeds (range 6-16 km · hr^-1) in a random order. In-shoe maximum plantar force (Fmax) was recorded using the Pedar-X system. Fmax was lowest at the 6 km · hr^-1 at 50% indicated BW condition at 1.02 ± 0.21BW and peaked at 2.31 ± 0.22BW for the 16 km · hr^-1 at 100% BW condition. Greater increases in Fmax were seen when increasing running speed while holding per cent BW constant than the reverse (0.74BW-0.91BW increase compared to 0.19-0.31BW). A table is presented with each of the 36 combinations of BW and running speed to allow a more objective progression of plantar loading during rehabilitation. Increasing running speed rather than increasing indicated per cent BW was shown to have the strongest effect on the magnitude of Fmax across the ranges of speeds and indicated per cent BWs examined.

Return to Sports Activity and Work After Autologous Chondrocyte Implantation of the Knee: Which Factors Influence Outcomes?

BACKGROUND

Autologous chondrocyte implantation (ACI) has been associated with satisfying results in everyday activities. Clinical results after ACI treatment of femorotibial lesions are superior in comparison with patellofemoral lesions. There is limited information regarding at which level recreational, amateur, and professional athletes can resume sports and physical activities as well as work after ACI and what parameters influence return to work and sports.

HYPOTHESIS

Return to sports activity and work is dependent on defect characteristics such as location and size.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 130 patients with isolated full-thickness cartilage defects of the knee joint treated with ACI between June 2000 and October 2007 were retrospectively studied by an established questionnaire that assessed sports-specific questions such as frequency, duration, and intensity. Engagement in 32 different sports disciplines was evaluated. In addition, work-specific data were evaluated according to classifications established by the REFA Association. Results were evaluated depending on patient- and defect-specific parameters.

RESULTS

The mean ± SD patient age at ACI was 36.2 ± 9.2 years, with a mean defect size of 4.4 ± 1.7 cm(2). Defects were located at the femorotibial compartment in 55.7% of cases, whereas lesions of the patellofemoral compartment were found in 44.3%. Mean duration of inability to work after ACI was 13.6 ± 11.0 weeks and did not appear to be influenced by patient age. Defect location and defect size did not appear to significantly influence return-to-work rates, but work intensity before surgery significantly influenced return-to-work rates and duration of absence from work. Workplace adaptations were necessary in only 9.2% of cases postoperatively. With regard to postoperative sports activity, 73.1% of patients were able to return to sports. Neither defect location nor size significantly influenced return to physical activity. Patients participated in a mean of 2.3 different sports during their lifetime. Both duration of exercise and number of sessions per week significantly decreased from before to after surgery. Detailed analysis of 32 different sporting activities revealed that high-impact as well as start-stop sports were generally abandoned in favor of endurance and low-intensity exercises. A lifetime level of competitiveness was maintained in 31.3% of cases, while return to elite sports at the time of the survey became highly unlikely (0.8%).

CONCLUSION

The study results illustrate that treatment of articular cartilage defects of the knee joint leads to satisfactory results concerning everyday activities. With the exception of physical labor, no essential adaptations needed to be made at work. Regarding sports activity, return to low- and moderate-intensity levels appears realistic in the majority of cases, whereas the likelihood of returning to activities with high stress applied on the knee joint is low. Neither defect location nor size appears to significantly influence postoperative sports activity or return-to-work rates.

Medial Femoral Condyle Cartilage Defect Biomechanics: Effect of Obesity, Defect Size, and Cartilage Thickness

BACKGROUND

Medial femoral condyle (MFC) chondral defects cause knee pain. Clinical studies have shown worse functional outcomes and cartilage defect fill rates after microfracture in obese patients (BMI ≥30) and for defects with size ≥2 cm(2).

PURPOSE

To determine the effect of obesity, defect size, and cartilage thickness on the force sustained at the base of full-thickness MFC cartilage defects during weightbearing.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight human cadaveric knees were loaded in 15° of flexion. A sensor measured force across the medial compartment. The area at the base of the defect protected from load, termed the "area of containment," was quantified, and loads simulating weightbearing for BMIs of 20, 30, and 40 were applied. A full-thickness cartilage defect was created on the MFC. Cycles of loads were applied for defect sizes with diameters of 6, 8, 10, 12, 14, 16, 18, and 20 mm. A second sensor recorded force at the base of the defect for defects with diameters of 14, 16, 18, and 20 mm.

RESULTS

Loads simulating BMI ≥30 led to a decrease in the area of containment for all defects ≥14 mm in diameter (P ≤ .038). Base of defect force increased for defects ≥16 mm in diameter (area, ≥2 cm(2)) between loaded and unloaded states (P ≤ .042) and for loads simulating BMI ≥30 (P ≤ .045). Cartilage rim thickness <2 mm showed higher base of defect force than did thickness ≥2 mm, for all BMI groups (P ≤ .025).

CONCLUSION

Increased force at the base of MFC cartilage defects was observed for weightbearing loads simulating BMI ≥30, for defect size ≥2 cm(2), and for rim thickness <2 mm. This may lead to a biomechanically unfavorable environment after microfracture in these patient subsets.

CLINICAL RELEVANCE

These biomechanical findings corroborate clinical studies that have noted worse outcomes after microfracture in patients with BMI ≥30 and cartilage defects of size ≥2 cm(2). Further clinical studies are needed to compare microfracture with other cartilage restoration procedures in these patient subsets.

Cartilage issues in football-today's problems and tomorrow's solutions

Articular cartilage injury is prevalent in football players and results from chronic joint stress or acute traumatic injuries. Articular cartilage injury can often result in progressive painful impairment of joint function and limit sports participation. Management of articular cartilage injury in athletes aims to return the player to competition, and requires effective and durable joint surface restoration that resembles normal hyaline articular cartilage that can withstand the high joint stresses of football. Existing articular cartilage repair techniques can return the athlete with articular cartilage injury to high-impact sports, but treatment does not produce normal articular cartilage, and this limits the success rate and durability of current cartilage repair in athletes. Novel scientific concepts and treatment techniques that apply modern tissue engineering technologies promise further advancement in the treatment of these challenging injuries in the high demand athletic population. We review the current knowledge of cartilage injury pathophysiology, epidemiology and aetiology, and outline existing management algorithms, developing treatment options and future strategies to manage articular cartilage injuries in football players.

Knee osteoarthritis: Clinical connections to articular cartilage structure and function

Articular cartilage is a unique biphasic material that supports a lifetime of compressive and shear forces across joints. When articular cartilage deteriorates, whether due to injury, wear and tear or normal aging, osteoarthritis and resultant pain can ensue. Understanding the basic science of the structure and biomechanics of articular cartilage can help clinicians guide their patients to appropriate activity and loading choices. The purpose of this article is to examine how articular cartilage structure and mechanics, may interact with risk factors to contribute to OA and how this interaction provides guidelines for intervention choices This paper will review the microstructure of articular cartilage, its mechanical properties and link this information to clinical decision making.

Results 2 Years After Matrix-Associated Autologous Chondrocyte Transplantation Using the Novocart 3D Scaffold: An Analysis of Clinical and Radiological Data

BACKGROUND

A range of scaffolds is available from various manufacturers for cartilage repair through matrix-associated autologous chondrocyte transplantation (MACT), with good medium- to long-term results.

PURPOSE

To evaluate clinical and magnetic resonance imaging (MRI) outcomes 2 years after MACT on the knee joint using the Novocart 3D scaffold based on a bilayered collagen type I sponge.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Of 28 initial patients, 23 were clinically and radiologically evaluated 24 months after transplantation. Indications for MACT were chondral or osteochondral lesions on the knee joint with a defect size >2 cm2, no instability, and no malalignment (axis deviation <5°). Then, MRI was performed on a 3-T scanner to assess the magnetic resonance observation of cartilage repair tissue (MOCART) and 3-dimensional (3D) MOCART scores. A variety of subjective scores (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Noyes sports activity rating scale, Tegner activity scale, and visual analog scale [VAS] for pain) were used for clinical evaluation.

RESULTS

Two years after MACT, the MRI evaluation showed a mean MOCART score of 73.2 ± 12.4 and a 3D MOCART score of 73.4 ± 9.7. Clinical results showed mean values of 69.8 ± 15.2 for the IKDC; 51.6 ± 21.2, 86.5 ± 13.9, 54.5 ± 23.6, 65.0 ± 8.0, and 91.5 ± 10.6 for the KOOS subscales (Quality of Life, Pain, Sports and Recreation, Symptoms, and Activities of Daily Living, respectively); 77.5 ± 12.7 for the Noyes scale; 4.4 ± 1.6 for the Tegner activity scale; and 1.8 ± 1.7 for the VAS, with statistically significant improvement in all scores other than KOOS-Symptoms.

CONCLUSION

Undergoing MACT using the Novocart 3D scaffold is an applicable method to treat large focal chondral and osteochondral defects, with good short-term clinical and radiological results.

Reconstruction of the Medial Patellofemoral Ligament: Clinical Outcomes and Return to Sports

BACKGROUND

Recent studies have shown that medial patellofemoral ligament (MPFL) reconstruction using a standardized technique provides significant improvements in all outcome scoring systems, with low complication rates and good patient satisfaction. Although numerous studies have assessed clinical results, there is little published literature investigating return to sporting activities after reconstruction of the MPFL.

PURPOSE

To demonstrate postoperative outcomes and the return-to-sports rate a minimum of 2 years after isolated MPFL reconstruction in a young patient cohort.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2007 and 2010, a total of 72 isolated MPFL reconstructions (in 68 patients) were performed for recurrent patellar dislocation. Pre- and postoperative knee assessment included a thorough history of symptoms and a clinical examination consisting of crepitus, range of motion, patellofemoral pain, and patellar apprehension. Knee function was assessed using the Kujala score, International Knee Documentation Committee score, Tegner activity score, visual analog scale (VAS), and Activity Rating Scale (ARS).

RESULTS

Of patients who participated in sports preoperatively (62/68 patients), 100% returned to sports after MPFL reconstruction; 53% returned at equal or higher levels, whereas 47% returned at lower levels. Fifty-four of 68 patients (79.4%) rated themselves as very satisfied or satisfied with the results. The median Kujala score improved significantly from 66 to 87.5 and the median International Knee Documentation Committee score from 60 to 79.8. The median VAS for pain score illustrated significant preoperative to postoperative improvement, from 4 to 2. Conversely, patients' activity levels according to the Tegner activity score dropped from 4.5 to 4, and the median Activity Rating Scale score dropped from 6 to 3. There was also a persistent instability rate of 10% as well as a slight loss of knee flexion in 24 of 72 knees.

CONCLUSION

Reconstruction of the MPFL is a safe and effective treatment for patellofemoral instability without severe trochlear dysplasia and allows most patients to engage in regular sports activities 2 years postoperatively, at least at a recreational level. However, potential complications, such as persistent instability, pain, and loss of flexion, must be considered.

Clinical and MRI evaluation of medium- to long-term results after autologous osteochondral transplantation (OCT) in the knee joint

PURPOSE

Autologous osteochondral transplantation (OCT) is one of the surgical options currently used to treat cartilage defects. It is the only cartilage repair method that leads to a transfer of hyaline cartilage repair tissue. The purpose of this study was to evaluate the magnetic resonance observation of cartilage repair tissue (MOCART) score, the 3D MOCART score and various clinical scores in patients after OCT in knee joints.

METHODS

Two women and eight men were evaluated 6-9 years (median 7.2 years) after OCT on the femoral condyle of the knee joint. All patients were evaluated by magnetic resonance imaging (MRI) measurement, using a 3.0 T Scanner with different cartilage-specific sequences. Clinical assessment included the knee injury and osteoarthritis outcome score (KOOS), the international knee documentation committee (IKDC) subjective knee form, the Noyes sport activity rating scale and the Tegner activity score. For MRI evaluation, the MOCART score and 3D MOCART score were applied.

RESULTS

Clinical long-term results after OCT showed median values of 77 (range 35.7-71.4) for the IKDC; 50 (6.3-100), 66.7 (30.6-97.2), 65 (0-75), 57.1 (35.7-71.4) and 80.9 (30.9-100) for the KOOS subscales (quality of life, pain sports, symptoms and activity of daily living); 61.4 (22.3-86.2) for the Noyes scale; and 3 (0-6) for the Tegner activity score. The median MOCART score was 75 (30-90) after both 1 and 2 years and 57.5 (35-90) after 7 years, as assessed by different cartilage-specific sequences. The 3D MOCART score showed values of 70 (50-85) and 60 (50-80) in the two different isotropic sequences after 7 years.

CONCLUSION

The MOCART and 3D MOCART scores are applicable tools for patient follow-up after OCT. Post-operative follow-up assessments would also benefit from the inclusion of OCT-specific parameters. Long-term results after OCT reflect an impairment in clinical scores in the first 2 years with good results during follow-up. Stable conditions were observed between 2 and 7 years after surgery. The filling of the defects and the cartilage interface appeared good at MRI evaluation after the first 2 years, but cartilage loss was observed between the medium- and long-term follow-ups. Isotropic imaging with multiplanar reconstruction is useful for daily clinical use to assess bony cylinders in cartilage repair, especially in combination with the 3D MOCART.

LEVEL OF EVIDENCE

Retrospective therapeutic study, Level IV.

Current concepts of articular cartilage restoration techniques in the knee

Context:

Articular cartilage injuries are common in patients presenting to surgeons with primary complaints of knee pain or mechanical symptoms. Treatment options include comprehensive nonoperative management, palliative surgery, joint preservation operations, and arthroplasty.

Evidence Acquisition:

A MEDLINE search on articular cartilage restoration techniques of the knee was conducted to identify outcome studies published from 1993 to 2013. Special emphasis was given to Level 1 and 2 published studies.

Study Design:

Clinical review.

Level of Evidence:

Level 3.

Results:

Current surgical options with documented outcomes in treating chondral injuries in the knee include the following: microfracture, osteochondral autograft transfer, osteochondral allograft transplant, and autologous chondrocyte transplantation. Generally, results are favorable regarding patient satisfaction and return to sport when proper treatment algorithms and surgical techniques are followed, with 52% to 96% of patients demonstrating good to excellent clinical outcomes and 66% to 91% returning to sport at preinjury levels.

Conclusion:

Clinical, functional, and radiographic outcomes may be improved in the majority of patients with articular cartilage restoration surgery; however, some patients may not fully return to their preinjury activity levels postoperatively. In active and athletic patient populations, biological techniques that restore the articular surface may be options that provide symptom relief and return patients to their prior levels of function.

Return to competitive football after major knee surgery: more questions than answers?

Despite significant advances in the diagnostics and treatment of knee injuries over the last decade, several challenges related to the subject "return to sport" remain largely unknown. For example, how should "return to sport" be defined precisely? What is the optimal timing and progression to enable a return to sport? Which criteria should be used during this process? What type of training is indicated? Which measurements can support the decision-making process? How do we optimally prepare athletes for competition without risking re-injury? This paper critically addresses these questions, and proposes a return to play model to prepare football players to compete after major knee surgery (anterior cruciate ligament reconstruction, cartilage repair). The goal is to re-integrate the player gradually into the game, taking into account his individual characteristics. Several evidence-based and empirical criteria are needed to plan and monitor the efficient return to competitive football. Injury-prevention education should be part of this process to maximise the chance of a durable career and decrease the risk of re-injury. However, because of the paucity of research on "return to sport", further research is more than warranted.

The effects of kinesio tape on isokinetic muscular function of horse racing jockeys

[Purpose] The purpose of this study was to conduct a scientific analysis of the effectiveness of Kinesio taping at preventing injury and improving horse racing jockey' performance, by studying the effects on isokinetic muscular function of Kinesio taping applied to the knee joint muscle. [Subjects] Eight horse racing jockeys were selected for this study. [Methods] Measurement of isokinetic muscular function of both flexor and extensor muscles was performed at the angular velocities of 60°/sec and 180°/sec using a Biodex system 3, before and after application of Kinesio taping to the rectus femoris, vastus medialis, vastus lateralis, and hamstring. [Result] At the angular velocities of 60°/sec and 180°/sec, significant differences were observed in both flexor and extensor peak torque, average power, and total work of the knee joint after application of Kinesio taping. [Conclusion] The application of Kinesio taping has a positive effect on the function of both knee flexors and extensors, and also kinetic ability. Therefore, its use would lead to a significant increase in the muscle function of horse racing jockeys.

Evidence-based status of second- and third-generation autologous chondrocyte implantation over first generation: a systematic review of level I and II studies

PURPOSE

The purpose of this study was to examine the Level I and II evidence for newer generations of autologous chondrocyte implantation (ACI) versus first-generation ACI and to establish whether the newer generations have overcome the limitations associated with first-generation ACI.

METHODS

A literature search was carried out for Level I and II evidence studies on cartilage repair using the PubMed database. All the studies that dealt with ACI were identified. Only Level I and II studies that compared newer generations against earlier generations were selected, whereas studies that compared ACI against other methods of cartilage repair were excluded.

RESULTS

A total of 7 studies matched the selection criteria. Two studies compared periosteum-based autologous chondrocyte implantation (P-ACI) against collagen membrane-based autologous chondrocyte implantation (C-ACI), whereas one study each compared membrane-associated autologous chondrocyte implantation (MACI) against P-ACI and C-ACI. One study on C-ACI compared results related to age, whereas 2 studies evaluated postoperative rehabilitation after MACI. There was weak evidence showing that C-ACI is better than P-ACI and that MACI is comparable with both P-ACI and C-ACI. The weak evidence is because of studies with short durations of follow-up, small numbers of patients, medium-sized defects, and younger age groups. There is good evidence favoring an accelerated weight-bearing regimen after MACI. There is currently no evidence that supports scaffold-based ACI or arthroscopic implantation over first-generation ACI.

CONCLUSIONS

The hypothesis is thus partly proved in favor of C-ACI/MACI against P-ACI with weak evidence, in favor of accelerated weight bearing after MACI with strong evidence, and not in favor of arthroscopic and scaffold-based implantations because of unavailable evidence. LEVEL OF EVIDENCE: Level II, systematic review of Level I and II studies.

Return to an athletic lifestyle after osteochondral allograft transplantation of the knee

BACKGROUND

Osteochondral allograft transplantation (OATS) is a treatment option that provides the ability to restore large areas of hyaline cartilage anatomy and structure without donor site morbidity and promising results have been reported in returning patients to some previous activities. However, no study has reported on the durability of return to activity in a setting where it is an occupational requirement.

HYPOTHESIS

Osteochondral allograft transplantation is less successful in returning patients to activity in a population in which physical fitness is a job requirement as opposed to a recreational goal.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review was conducted of 38 consecutive OATS procedures performed at a single military institution by 1 of 4 sports medicine fellowship-trained orthopaedic surgeons. All patients were on active duty at the time of the index procedure, and data were collected on demographics, return to duty, Knee Injury and Osteoarthritis Outcome Score (KOOS), and ultimate effect on military duty. Success was defined as the ability to return to the preinjury military occupational specialty (MOS) with no duty-limiting restrictions.

RESULTS

The mean lesion size treated was 487.0 ± 178.7 mm(2). The overall rate of return to full duty was 28.9% (11/38). An additional 28.9% (11/38) were able to return to limited activity with permanent duty modifications. An alarming 42.1% (16/38) were unable to return to military activity because of their operative knee. When analyzed for return to sport, only 5.3% (2/38) of patients were able to return to their preinjury level. Eleven patients underwent concomitant procedures. Statistical power was maintained by analyzing data in aggregate for cases with versus without concomitant procedures. When the 11 undergoing concomitant procedures were removed from the data set, the rate of return to full activity was 33.3% (9/27), with 22.3% (6/27) returning to limited activity and 44.4% (12/27) unable to return to activity. In this subset, 7.4% (2/27) were able to return to a preinjury level of sport. The KOOS values were significantly higher in the full activity group when compared with the limited and no activity groups (P < .01). Branch of service was a significant predictor of outcome, with Marine Corps and Navy service members more likely to return to full activity compared with Army and Air Force members. A MOS of combat arms was a significant predictor of a poor outcome. All patients demonstrated postoperative healing of their grafts as documented in their medical chart, and no patient in the series required revision for problems with graft incorporation.

CONCLUSION

Osteochondral allograft transplantation for the treatment of large chondral defects in the knee met with disappointing results in an active-duty population and was even less reliable in returning this population to preinjury sport levels. Branch of service and occupational type predicted the return to duty, but other traditional predictors of outcome such as rank and years of service did not. The presence of concomitant procedures did not have an effect on outcome with respect to activity or sport level with the numbers available for analysis.

Advanced patellofemoral cartilage lesions in patients younger than 50 years of age: is there an ideal operative option?

PURPOSE

The purpose of this review was to determine if there is an ideal operation for large symptomatic articular cartilage lesions on the undersurface of the patella in young patients.

METHODS

A systematic search of PubMed was conducted to determine the outcome of operations performed for large patellar lesions in young patients. Inclusionary criteria were English language, original clinical trials published from 1992 to 2012, patellar lesions 4 cm(2) or larger, mean patient age 50 years or younger, and all evidence levels.

RESULTS

Of 991 articles identified, 18 met the inclusionary criteria, encompassing 840 knees in 828 patients. These included 613 knees that underwent autologous chondrocyte implantation (ACI) (11 studies), 193 knees that had patellofemoral arthroplasty (PFA) (5 studies), and 34 knees that underwent osteochondral allografting (OA) (2 studies). The mean patient age was 37.2 years and the mean follow-up was 6.2 years. Long-term follow-up (>10 years) was available in only 4 studies (2 PFA, 1 ACI, 1 OA). All studies except one were Level IV and none were randomized or had a control group. Twenty-one outcome instruments were used to determine knee function. When taking into account knees that either failed or had fair/poor function, the percentage of patients who failed to achieve a benefit averaged 22% after PFA and 53% after OA and ranged from 8% to 60% after ACI. In addition, all 3 procedures had unacceptable complication and reoperation rates.

CONCLUSIONS

The combination of failure rates and fair/poor results indicated that all 3 procedures had unpredictable results. We concluded that a long-term beneficial effect might not occur in one of 3 ACI and PFA procedures and in 2 of 3 OA procedures. We were unable to determine an ideal surgical procedure to treat large symptomatic patellar lesions in patients 50 years or younger.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

Activity-Related Outcomes of Articular Cartilage Surgery: A Systematic Review

OBJECTIVE

The purpose of this systematic review was to compare activity-based outcomes after microfracture, autologous chondrocyte implantation (ACI), and osteochondral autograft (OAT).

DESIGN

Multiple databases were searched with specific inclusion and exclusion criteria for level III and higher studies with activity outcomes after microfracture, OAT, osteochondral allograft, and ACI. Activity-based outcomes included the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner Score, the Cincinnati Knee scores, the International Knee Documentation Committee (IKDC) subjective knee score, the Marx activity score, and/or the rate of return-to-sport.

RESULTS

Twenty studies were included (1,375 patients). Although results were heterogeneous, significant advantages were seen for ACI and OAT as compared with microfracture in Tegner scores at 1 year (ACI vs. microfracture, P = 0.0016), IKDC scores at 2 years (ACI vs microfracture, P = 0.046), Lysholm scores at 1 year (OAT vs microfracture, P = 0.032), and Marx scores at 2 years (OAT vs microfracture, P < 0.001). The only score or time point to favor microfracture was Lysholm score at 1 year (ACI vs microfracture, P = 0.037). No other standardized outcome measures or time points were significantly different. Several studies demonstrated significantly earlier return to competition with microfracture. Overall reoperation rates were similar, but of reoperations, a higher proportion of those following ACI were unplanned with the majority of performed for graft delamination or hypertrophy.

CONCLUSIONS

ACI and OAT may have some benefits over microfracture, although return-to-sport is fastest following microfracture. Heterogeneity in technique, outcome measures, and patient populations hampers systematic comparison within the current literature.

Application of sodium triple-quantum coherence NMR spectroscopy for the study of growth dynamics in cartilage tissue engineering

We studied the tissue growth dynamics of tissue-engineered cartilage at an early growth stage after cell seeding for four weeks using sodium triple-quantum coherence NMR spectroscopy. The following tissue-engineering constructs were studied: 1) bovine chondrocytes cultured in alginate beads; 2) bovine chondrocytes cultured as pellets (scaffold-free chondrocyte pellets); and 3) human marrow stromal cells (HMSCs) seeded in collagen/chitosan based biomimetic scaffolds. We found that the sodium triple-quantum coherence spectroscopy could differentiate between different tissue-engineered constructs and native tissues based on the fast and slow components of relaxation rate as well as on the average quadrupolar coupling. Both fast (Tf ) and slow (Ts ) relaxation times were found to be longer in chondrocyte pellets and biomimetic scaffolds compared to chondrocytes suspended in alginate beads and human articular cartilage tissues. In all cases, it was found that relaxation rates and motion of sodium ions measured from correlation times were dependent on the amount of macromolecules, high cell density and anisotropy of the cartilage tissue-engineered constructs. Average quadrupolar couplings were found to be lower in the engineered tissue compared to native tissue, presumably due to the lack of order in collagen accumulated in the engineered tissue. These results support the use of sodium triple-quantum coherence spectroscopy as a tool to investigate anisotropy and growth dynamics of cartilage tissue-engineered constructs in a simple and reliable way.

Anatomic variation of depth-dependent mechanical properties in neonatal bovine articular cartilage

Articular cartilage has well known depth-dependent structure and has recently been shown to have similarly non-uniform depth-dependent mechanical properties. Here, we study anatomic variation of the depth-dependent shear modulus and energy dissipation rate in neonatal bovine knees. The regions we specifically focus on are the patellofemoral groove, trochlea, femoral condyle, and tibial plateau. In every sample, we find a highly compliant region within the first 500 µm of tissue measured from the articular surface, where the local shear modulus is reduced by up to two orders of magnitude. Comparing measurements taken from different anatomic sites, we find statistically significant differences localized within the first 50 µm. Histological images reveal these anatomic variations are associated with differences in collagen density and fiber organization.

Advanced Strategies for Articular Cartilage Defect Repair

Articular cartilage is a unique tissue owing to its ability to withstand repetitive compressive stress throughout an individual's lifetime. However, its major limitation is the inability to heal even the most minor injuries. There still remains an inherent lack of strategies that stimulate hyaline-like articular cartilage growth with appropriate functional properties. Recent scientific advances in tissue engineering have made significant steps towards development of constructs for articular cartilage repair. In particular, research has shown the potential of biomaterial physico-chemical properties significantly influencing the proliferation, differentiation and matrix deposition by progenitor cells. Accordingly, this highlights the potential of using such properties to direct the lineage towards which such cells follow. Moreover, the use of soluble growth factors to enhance the bioactivity and regenerative capacity of biomaterials has recently been adopted by researchers in the field of tissue engineering. In addition, gene therapy is a growing area that has found noteworthy use in tissue engineering partly due to the potential to overcome some drawbacks associated with current growth factor delivery systems. In this context, such advanced strategies in biomaterial science, cell-based and growth factor-based therapies that have been employed in the restoration and repair of damaged articular cartilage will be the focus of this review article.

Ability to return to sports 5 years after matrix-associated autologous chondrocyte transplantation in an average population of active patients

BACKGROUND

Cartilage injuries often occur during sports activities, and return to sports after cartilage surgery is an important outcome parameter for different treatment methods in the competitive as well as the recreationally active population.

HYPOTHESIS

At the time of midterm follow-up after matrix-associated autologous chondrocyte transplantation (MACT), return to recreational sports at the preinjury level will be possible.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Seventy patients (51 men, 19 women; age [mean ± standard deviation], 34.9 ± 8.6 y; range, 18-55 y) were clinically evaluated 5 years after MACT through subjective clinical scores such as the Knee Injury and Osteoarthritis Outcome Score (KOOS) sport and recreation subscales, the Tegner activity scale, and the Noyes sports activity rating scale. The level of sports participation was included in the investigation.

RESULTS

The results 5 years after MACT showed mean values of 60.1 for the KOOS-sport, 67.4 for the Noyes, and 3.8 for the Tegner scores, meaning that regular sports activity such as cycling or running on flat ground, as well as medium-level manual labor, is possible. We noted that 74.3% of our patients returned to at least their preinjury sports level.

CONCLUSION

Midterm postoperative results after MACT show that in a moderately active population, participation in regular sports is possible for most patients, at least at their preinjury recreational level and intensity, and there is a good rate of return to sports.

Sensitivity of magnetic resonance imaging for detection of patellofemoral articular cartilage defects

PURPOSE

Chondral defects within the patellofemoral compartment are common and lack the ability to heal on their own. Early detection of these lesions with a noninvasive modality would be beneficial in delaying or preventing their possible progression to osteoarthritis. We hypothesized that magnetic resonance imaging (MRI) is a sensitive, specific, and accurate imaging modality for the detection of patellofemoral chondral defects with substantial interobserver reliability and that MRI has a higher sensitivity, specificity, and accuracy for detecting patellar defects than trochlear defects.

METHODS

A systematic review of multiple medical databases was performed by use of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol. Analysis of studies that reported diagnostic performance of MRI in the assessment of patellofemoral chondral defects (patella and trochlea), using arthroscopy as the reference gold standard, was performed. Sensitivity, specificity, accuracy, and interobserver reliability were reported. Significant heterogeneity across studies precluded meta-analysis.

RESULTS

MRI was more sensitive in detection of patellar (87%) versus trochlear (72%) defects. MRI was similarly specific for patellar (86%) and trochlear (89%) defects. MRI was similarly accurate for patellar (84%) and trochlear (83%) defects. Interobserver agreement was substantial to almost perfect for both patellar and trochlear defects.

CONCLUSIONS

MRI is a highly sensitive, specific, and accurate noninvasive diagnostic modality for the detection of chondral defects in the patellofemoral compartment of the knee, using arthroscopy as the reference gold standard. Although there was wide variability in the statistical parameters assessed, MRI was more sensitive for detection of patellar versus trochlear defects and similarly specific and accurate for patellar and trochlear defects. Interobserver reliability is substantial to near perfect in the assessment of these lesions, without a significant difference between patellar and trochlear defects.

CLINICAL RELEVANCE

Use of MRI may allow early detection of chondral defects within the patellofemoral compartment, enabling clinicians to adopt strategies to delay or prevent progression to osteoarthritis.

LEVEL OF EVIDENCE

Level III, systematic review of Level I, II, and III studies.

Ten-year follow-up of a prospective, randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint of athletes

BACKGROUND

Various techniques have proven to be effective for treating articular cartilage defect (ACD) and osteochondral defect (OCD) of the knee joint, but knowledge regarding which method is best still remains uncertain.

PURPOSE

To evaluate and compare the outcomes of mosaic-type osteochondral autologous transplantation (OAT) and microfracture (MF) procedures for the treatment of articular cartilage defects of the knee joint in young active athletes. This article represents an update of the clinical results at 10 years.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Between 1998 and 2002, a total of 60 athletes with a mean age of 24.3 years (range, 15-40 years) and with a symptomatic ACD or OCD in the knee were randomized to undergo either OAT or MF. Patients were then evaluated postoperatively using the International Cartilage Repair Society (ICRS) score, Tegner activity score, radiographs, and magnetic resonance imaging. The mean follow-up time was 10.4 years (range, 9-11 years).

RESULTS

Three to 10 years after the OAT and MF procedures, patients had lower ICRS and Tegner scores (P < .05), but both groups still had significant clinical improvement over presurgery scores according to ICRS scores at 10-year follow-up. Statistically significantly better results were detected in patients in the OAT group compared with those in the MF group at 10 years (P < .005). At 10-year follow-up, there were 15 failures (26%), including 4 failures (14%) of the OAT and 11 failures (38%) of MF treatment (P < .05). Seven patients (25%) from the OAT group and 14 patients (48%) from the MF group had radiographic evidence of Kellgren-Lawrence grade I osteoarthritis at 10 years, but these differences were not significant (P = .083) or related to the clinical results. The ICRS and Tegner scores of younger athletes (<25 years at the time of primary surgery) remained significantly higher after 10 years compared with older patients (P < .05); 15 of 20 patients (75%) in the OAT group and 8 of 22 patients (37%) in the MF group maintained the same physical activity level.

CONCLUSION

The OAT technique for ACD or OCD repair in the athletic population allows for a higher rate of return to and maintenance of sports at the preinjury level compared with MF.

AMIC Cartilage Repair in a Professional Soccer Player

We report a case of a professional soccer player suffering from a traumatic cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle treated with an enhanced microfracture technique (AMIC). Autologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. Because of the cartilage lesion (3 cm(2)), an AMIC procedure was performed followed by a rehabilitation program according to the protocols in the literature, (Steadman et al.; 2003). After 8 months of rehabilitation, the player returned to team training and after 10 months to competition. Altogether he returned to the same skill level for almost one year after the index operation. He is very satisfied with the clinical results after AMIC, which corresponds with the Lysholm score of 90 points at 12 months.

[Cell-based therapy options for osteochondral defects. Autologous mesenchymal stem cells compared to autologous chondrocytes]

Cartilage defects are multifactorial and site-specific and therefore need a clear analysis of the underlying pathology as well as an individualized therapy so that cartilage repair lacks a one-for-all therapy. The results of comparative clinical studies using cultured chondrocytes in autologous chondrocyte implantation (ACI) have shown some superiority over conventional microfracturing under defined conditions, especially for medium or large defects and in long-term durability. Adult mesenchymal stem cells can be isolated from bone marrow, have the potency to proliferate in culture and are capable of differentiating into the chondrogenic pathway. They represent a promising versatile cell source for cartilage repair but the ideal conditions for cultivation and application in cartilage repair are not yet known or have not yet been characterized. Adding a scaffold offers mechanical stability and advances chondrogenic differentiation for both possible cell sources.

The impact of sport and active recreation injuries on physical activity levels at 12 months post-injury

The aim of this study was to evaluate the impact of serious sport and active recreation injury on 12-month physical activity levels. Adults admitted to hospital with sport and active recreation-related injuries, and captured by the Victorian Orthopaedic Trauma Outcomes Registry were recruited to the study. Changes between preinjury and 12 month post-injury physical activity was assessed using the short International Physical Activity Questionnaire (IPAQ). Independent demographic, injury, and hospital variables were assessed for associations with changes in physical activity levels, using multivariate linear regression. A total of 324 patients were recruited, of which 98% were followed up at 12 months. Mean short IPAQ scores decreased from 7650 METS (95% CI: 7180, 8120) preinjury to 3880 METS; (95% CI: 3530, 4250) post-injury, independent of functional recovery. Education level and occupation group were the only variables independently associated with changes in physical activity levels post-injury. These results highlighted that sport and active recreation injuries lead to significant reductions in physical activity levels. Hence, the prevention of sport and active recreation injuries is important when considering promotion of activity at a population level.

Clinical comparison of the osteochondral autograft transfer system and subchondral drilling in osteochondral defects of the first metatarsal head

BACKGROUND

Osteochondral defects of the first metatarsal head can deteriorate to osteoarthritis of the first metatarsophalangeal joint if left untreated. Treatment options for osteochondral defects of the first metatarsal head vary widely.

PURPOSE

To compare the clinical outcomes of the osteochondral autograft transfer system with those of subchondral drilling for the treatment of osteochondral defects of the first metatarsal head.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The authors retrospectively evaluated 24 cases of osteochondral defects of the first metatarsal head treated operatively; 14 patients underwent subchondral drilling (group A), while 10 were treated with the osteochondral autograft transfer system (group B). The association of variables of osteochondral defects with clinical outcomes was assessed in each group. Clinical outcomes were evaluated according to a visual analog scale (VAS) for pain, the American Orthopaedic Foot and Ankle Society (AOFAS) hallux metatarsophalangeal-interphalangeal scale, and the Roles and Maudsley score. The Tegner activity scale and an activity rating scale were used to determine the activity levels.

RESULTS

The mean VAS score in both groups was significantly improved (from 6.9 ± 0.9 to 3.9 ± 1.3 in group A and from 7.4 ± 0.8 to 3.4 ± 1.2 in group B; P < .05). No difference was noted between the 2 groups at final follow-up (P = .651). The mean AOFAS score in both groups was significantly improved (from 62.9 ± 5.8 to 73.2 ± 8.2 in group A and from 65.0 ± 4.1 to 81.5 ± 5.8 in group B; P < .05). There was a significant difference in mean AOFAS score between the 2 groups at final follow-up (P = .032). Large defect size (≥50 mm(2)) and the existence of a subchondral cyst were significant predictors of unsatisfactory clinical outcomes in group A (P = .047 and P = .019, respectively). Multivariate analyses showed a defect size larger than 50 mm(2) was associated with significantly worse outcomes on the last follow-up VAS and AOFAS scores in group A (P = .005 for VAS and P = .006 for AOFAS). There was no association of defect size and subchondral cyst with clinical outcomes in group B (P > .05). No association was found between location of the defect area and clinical outcome in either group.

CONCLUSION

For osteochondral defects larger than 50 mm(2) or when a subchondral cyst exists, the osteochondral autograft transfer system could potentially be used as a treatment of choice for osteochondral defects of the first metatarsal head to restore functionality of the metatarsophalangeal joint.

Knee chondral injuries: clinical treatment strategies and experimental models

Articular cartilage has a very limited capacity to repair and as such premature joint degeneration is often the end point of articular injuries. Patients with chondral injury have asymptomatic periods followed by others in which discomfort or pain is bearable. The repair of focal cartilage injuries requires a precise diagnosis, a completed knee evaluation to give the correct indication for surgery proportional to the damage and adapted to each patient. Many of the surgical techniques currently performed involve biotechnology. The future of cartilage repair should be based on an accurate diagnosis using new MRI techniques. Clinical studies would allow us to establish the correct indications and surgical techniques implanting biocompatible and biodegradable matrices with or without stem cells and growth factors. Arthroscopic techniques with the design of new instruments can facilitate repair of patella and tibial plateau lesions.

Full-thickness knee articular cartilage defects in national football league combine athletes undergoing magnetic resonance imaging: prevalence, location, and association with previous surgery

PURPOSE

To better define the prevalence and location of full-thickness articular cartilage lesions in elite football players undergoing knee magnetic resonance imaging (MRI) at the National Football League (NFL) Invitational Combine and assess the association of these lesions with previous knee surgery.

METHODS

We performed a retrospective review of all participants in the NFL Combine undergoing a knee MRI scan from 2005 to 2009. Each MRI scan was reviewed for evidence of articular cartilage disease. History of previous knee surgery including anterior cruciate ligament reconstruction, meniscal procedures, and articular cartilage surgery was recorded for each athlete. Knees with a history of previous articular cartilage restoration surgery were excluded from the analysis.

RESULTS

A total of 704 knee MRI scans were included in the analysis. Full-thickness articular cartilage lesions were associated with a history of any previous knee surgery (P < .001) and, specifically, previous meniscectomy (P < .001) but not with anterior cruciate ligament reconstruction (P = .7). Full-thickness lesions were present in 27% of knees with a previous meniscectomy compared with 12% of knees without any previous meniscal surgery. Full-thickness lesions in the lateral compartment were associated with previous lateral meniscectomy (P < .001); a similar relation was seen for medial meniscus tears in the medial compartment (P = .01).

CONCLUSIONS

Full-thickness articular cartilage lesions of the knee were present in 17.3% of elite American football players at the NFL Combine undergoing MRI. The lateral compartment appears to be at greater risk for full-thickness cartilage loss. Previous knee surgery, particularly meniscectomy, is associated with these lesions.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Return to athletic activity after osteochondral allograft transplantation in the knee

BACKGROUND

Fresh-stored osteochondral allografts have been used successfully to resurface large chondral and osteochondral defects of the knee. However, there are limited data available for the return to athletic activity.

PURPOSE

To review the rate of return to athletic activity after osteochondral allograft transplantation in the knee and to identify any potential risk factors for not returning to sport.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Forty-three athletes were treated with fresh-stored osteochondral allograft transplantation for symptomatic large chondral or osteochondral defects of the knee from 2000 to 2010. The average age of the athletes (30 men, 13 women) was 32.9 years (range, 18-49 years). Patients were prospectively evaluated by International Knee Documentation Committee (IKDC), activities of daily living scale of the Knee Injury and Osteoarthritis Outcome Score (KOOS), Marx Activity Rating Scale, and Cincinnati Sports Activity Scale scores. A multivariable regression analysis was performed to identify potential risk factors for failure to return to sport at the preinjury level.

RESULTS

At an average 2.5-year follow-up, limited return to sport was possible in 38 of 43 athletes (88%), with full return to the preinjury level achieved in 34 of 43 athletes (79%). In these 34 athletes, time to return to sport was 9.6 ± 3.0 months. Age ≥25 years (P = .04) and preoperative duration of symptoms greater than 12 months (odds ratio, 37; P = .003) negatively affected the ability to return to sport. In the athletes who returned to their previous level of competition, IKDC (P < .001), KOOS (P = .02), and Marx Activity Rating Scale (P < .001) scores were all significantly greater than in those athletes who did not return to sport.

CONCLUSION

Osteochondral allograft transplantation in an athletic population for chondral and osteochondral defects in the knee allows for a high rate of return to sport. Risk factors for not returning to sport included age ≥25 years and preoperative duration of symptoms ≥12 months.