Obesity and sex influence fatty infiltration of the rotator cuff: the Rotator Cuff Outcomes Workgroup (ROW) and Multicenter Orthopaedic Outcomes Network (MOON) cohorts.

BACKGROUND: Fatty infiltration (FI) is one of the most important prognostic factors for outcomes after rotator cuff surgery. Established risk factors include advancing age, larger tear size, and increased tear chronicity. A growing body of evidence suggests that sex and obesity are associated with FI; however, data are limited. METHODS: We recruited 2 well-characterized multicenter cohorts of patients with rotator cuff tears (Multicenter Orthopaedic Outcomes Network [MOON] cohort [n = 80] and Rotator Cuff Outcomes Workgroup [ROW] cohort [n = 158]). We used multivariable logistic regression to evaluate the relationship between body mass index (BMI) and the presence of FI while adjusting for the participant's age at magnetic resonance imaging, sex, and duration of shoulder symptoms, as well as the cross-sectional area of the tear. We analyzed the 2 cohorts separately and performed a meta-analysis to combine estimates. RESULTS: A total of 27 patients (33.8%) in the Multicenter Orthopaedic Outcomes Network (MOON) cohort and 57 patients (36.1%) in the Rotator Cuff Outcomes Workgroup (ROW) cohort had FI. When BMI < 25 kg/m2 was used as the reference category, being overweight was associated with a 2.37-fold (95% confidence interval [CI], 0.77-7.29) increased odds of FI and being obese was associated with a 3.28-fold (95% CI, 1.16-9.25) increased odds of FI. Women were 4.9 times (95% CI, 2.06-11.69) as likely to have FI as men. CONCLUSIONS: Among patients with rotator cuff tears, obese patients had a substantially higher likelihood of FI. Further research is needed to assess whether modifying BMI can alter FI in patients with rotator cuff tears. This may have significant clinical implications for presurgical surgical management of rotator cuff tears. Sex was also significantly associated with FI, with women having higher odds of FI than men. Higher odds of FI in female patients may also explain previously reported early suboptimal outcomes of rotator cuff surgery and higher pain levels in female patients as compared with male patients.

Epidemiology of the Frequency, Etiology, Direction, and Severity (FEDS) system for classifying glenohumeral instability.

HYPOTHESIS: The purpose of this multicenter epidemiologic study was to determine the distribution of patients within the Frequency, Etiology, Direction, and Severity (FEDS) classification system to determine which categories are of clinical importance. METHODS: Shoulder instability patients were identified using International Classification of Diseases, Ninth Revision coding data from 3 separate institutions from 2005-2010. Data were collected retrospectively. Details of instability were recorded in accordance with the FEDS classification system. Each patient was assigned a classification within the FEDS system. After all patients were assigned to a group, each group was individually analyzed and compared with the other groups. RESULTS: There are a total of 36 possible combinations within the FEDS system. Only 16 categories were represented by at least 1% of our patient population. Six categories captured at least 5% of all patients with shoulder instability. Only 2 categories represented greater than 10% of the population: solitary, traumatic, anterior dislocation, with 95 patients (24.8%), and occasional, traumatic, anterior dislocation, with 63 patients (16.4%). CONCLUSIONS: There are 16 categories within the FEDS classification that are clinically significant. Solitary, traumatic, anterior dislocation and occasional, traumatic, anterior dislocation were the most frequently observed in our cohort.

The Surgical Management of Osteochondritis Dissecans of the Knee in the Skeletally Immature: A Survey of the Pediatric Orthopaedic Society of North America (POSNA) Membership.

BACKGROUND: While the characteristics of osteochondritis dissecans (OCD) of the knee that require surgery to heal have been described, several surgical techniques/procedures exist with no consensus established regarding timing of treatment and specific surgical intervention. In this study, we aim to determine current trends in surgical treatment for OCD lesions in the skeletally immature who have failed 6 months of nonoperative management by surveying a large cohort of orthopaedic surgeons. METHODS: An electronic survey designed using REDCap to capture surgeon treatment preferences for OCD lesions was distributed to members of the Pediatric Orthopaedic Society of North America (POSNA). The survey inquired about treating physicians' training and demographics. It then offered a series of clinical vignettes alongside imaging describing patients with varying degrees of severity of OCD following nonoperative treatment. Surgeons were prompted to select from a variety of multiple-choice-based options for further patient management. Standard descriptive statistics were used to summarize and compare the responses. RESULTS: Of the 129 POSNA members completing the pediatric survey, 97.7% were attending level orthopaedic surgeons, the majority identifying with an academic institution and treating mostly skeletally immature patients. In the skeletally immature population, the majority would treat intact, stable OCD lesions with drilling in a retroarticular or transarticular manner. Preferred treatment for unstable, salvageable lesions was screw fixation using bioabsorble materials or metal with variable pitch with no bone graft. The majority of respondents would treat unstable, unsalvageable OCD lesions with chondroplasty and osteochondral transplant/transfer or microfracture/drilling. CONCLUSIONS: The POSNA membership appears to agree on principle in terms of treatment modalities for various stages of OCD lesions in the skeletally immature, whereas individual techniques of achieving these principles may vary. Members endorse drilling for stable intact lesions; fixation for unstable, salvageable lesions; and "defect fill" for unsalvageable lesions. CLINICAL SIGNIFICANCE: OCD surgical treatment patterns can be used in future studies to determine which techniques are most effective for given indications, with the goal of designing a research-proven optimal treatment regimen for skeletally immature patients.

2013 Neer Award: predictors of failure of nonoperative treatment of chronic, symptomatic, full-thickness rotator cuff tears.

BACKGROUND: The purpose of this study is to help define the indications for rotator cuff repair by identifying predictors of failure of nonoperative treatment. METHODS: A prospective, multicenter, cohort study design was used. All patients with full-thickness rotator cuff tears on magnetic resonance imaging were offered participation. Baseline data from this cohort were used to examine risk factors for failing a standard rehabilitation protocol. Patients who underwent surgery were defined as failing nonoperative treatment. A Cox proportional hazards model was fit to determinethe baseline factors that predicted failure. The dependent variable was time to surgery. The independent variables were tear severity and baseline patient factors: age, activity level, body mass index, sex, Single Assessment Numeric Evaluation score, visual analog scale score for pain, education, handedness, comorbidities, duration of symptoms, strength, employment, smoking status, and patient expectations. RESULTS: Of the 433 subjects in this study, 87 underwent surgery with 93% follow-up at 1 year and 88% follow-up at 2 years. The median age was 62 years, and 49% were female patients. Multivariate modeling, adjusted for the covariates listed previously, identified patient expectations regarding physical therapy (P < .0001) as the strongest predictor of surgery. Higher activity level (P = .011) and not smoking (P = .023) were also significant predictors of surgery. CONCLUSION: A patient's decision to undergo surgery is influenced more by low expectations regarding the effectiveness of physical therapy than by patient symptoms or anatomic features of the rotator cuff tear. As such, patient symptoms and anatomic features of the chronic rotator cuff tear may not be the best features to use when deciding on surgical intervention.

Does arthroscopic knee surgery work?

A recent randomized trial from the Finnish Degenerative Meniscal Lesion Study Group was published in the New England Journal of Medicine and attempted to determine the efficacy of partial meniscectomy without osteoarthritis. Patients were randomized to either arthroscopic partial meniscectomy or sham surgery. The authors concluded that the clinical outcomes after arthroscopic partial meniscectomy were no better than those after the sham surgical procedure. However, there are several important limitations of this trial that make it difficult to generalize to the 700,000 arthroscopic partial meniscectomies performed in the United States each year. In this small sample of 146 patients, patients with traumatic meniscal tears and locking symptoms-those most likely to benefit from a partial meniscectomy-were excluded. In addition, although patients with radiographic arthritis were excluded, most of the patients in the study had degenerative changes at the time of arthroscopy. Therefore it is difficult to determine whether the patients were symptomatic from their chondral degeneration or their degenerative meniscal tear. In our opinion this study does not change the role of surgery in current clinical practice. The primary indication for arthroscopic partial meniscectomy remains symptoms of well-localized joint line pain with acute onset and mechanical symptoms such as catching or locking that have failed comprehensive nonoperative management.

The association of metabolic syndrome markers with adhesive capsulitis.

BACKGROUND: Research has associated adhesive capsulitis with diabetes mellitus but suggests that glucose-mediated injury may begin before diabetes is diagnosed. The period preceding diabetes is often marked by metabolic syndrome. METHODS: We investigated the relationship between metabolic syndrome components (insulin resistance, hypertension, dyslipidemia, and obesity) and the development of adhesive capsulitis using a case-control study. We retrospectively reviewed 150 consecutive adhesive capsulitis patient charts to determine the prevalence of obesity and of medications used for treating metabolic syndrome elements and compared these with previously reported nationwide values. RESULTS: The prevalence of anti-hyperglycemia medications in the adhesive capsulitis cohort was 18.4% (95% confidence interval [CI], 12.9%-25.7%), twice the national rate of diagnosed diabetes of 7.6% (95% CI, 6.7%-8.5%). In the 20- to 39-year-old group, the prevalence of anti-hyperglycemic medications, 26.3% (95% CI, 11.8%-48.8%), was over 10 times the nationwide rate. The overall prevalence of hypertensive medication use in the adhesive capsulitis group, 33.1% (95% CI, 25.9%-41.2%), was notably higher than the nationwide rate, 21.6% (95% CI, 19.8%-23.4%). In the 40- to 64-year-old group, the prevalence of hypertensive medication use, 36.8% (95% CI, 28.6%-46.0%), was notably higher than the nationwide rate of 24.5% (95% CI, 22.2%-27.0%). The prevalence of anti-lipid medications and obesity was similar between the groups. CONCLUSIONS: The relationship between adhesive capsulitis and metabolic syndrome remains unclear. Our results confirm previous work associating hyperglycemia with adhesive capsulitis. We have also shown a possible association of hypertension, part of metabolic syndrome and a proinflammatory condition, with adhesive capsulitis, which has not been previously described.

The duration of symptoms does not correlate with rotator cuff tear severity or other patient-related features: a cross-sectional study of patients with atraumatic, full-thickness rotator cuff tears.

HYPOTHESIS: The purpose of this cross-sectional study is to determine whether the duration of symptoms influences the features seen in patients with atraumatic, full-thickness rotator cuff tears. Our hypothesis is that an increasing duration of symptoms will correlate with more advanced findings of rotator cuff tear severity on magnetic resonance imaging, worse shoulder outcome scores, more pain, decreased range of motion, and less strength. METHODS: We enrolled 450 patients with full-thickness rotator cuff tears in a prospective cohort study to assess the effectiveness of nonoperative treatment and factors predictive of success. The duration of patient symptoms was divided into 4 groups: 3 months or less, 4 to 6 months, 7 to 12 months, and greater than 12 months. Data collected at patient entry into the study included (1) demographic data, (2) history and physical examination data, (3) radiographic imaging data, and (4) validated patient-reported measures of shoulder status. Statistical analysis included a univariate analysis with the Kruskal-Wallis test and Pearson test to identify statistically significant differences in these features for different durations of symptoms. RESULTS: A longer duration of symptoms does not correlate with more severe rotator cuff disease. The duration of symptoms was not related to weakness, limited range of motion, tear size, fatty atrophy, or validated patient-reported outcome measures. CONCLUSIONS: There is only a weak relationship between the duration of symptoms and features associated with rotator cuff disease.

Obesity is associated with muscle atrophy in rotator cuff tear.

Objective: The primary goal of this study is to evaluate the relationship between Body Mass Index (BMI) and muscle atrophy in individuals with rotator cuff tears. Methods: This study consists of patients with rotator cuff tears identified by MRI from two independent cohorts, the Rotator Cuff Outcomes Workgroup (ROW) and the Multicenter Orthopaedic Outcomes Network (MOON). Presence of atrophy (yes/no) and severity of atrophy (as an ordinal variable) were assessed on MRI by expert physicians. We used multivariable regression models to evaluate the relationship between BMI and muscle atrophy while adjusting for age and sex in each study, conducted sensitivity analyses for full-thickness tear and combined results using inverse variance-weighted meta-analysis. Results: A total of 539 patients (MOON=395, ROW=144) from the combined cohorts had MRI data available on muscle atrophy. Among these patients, 246 (46%) had atrophy of at least one of the muscles of the rotator cuff and 282 (52%) had full-thickness tears. In meta-analysis across both cohorts, each 5 kg/m2 increase in BMI was associated with a 21% (aOR=1.21, 95% CI=1.02, 1.43) increased odds of having muscle atrophy among individuals with any tear size, and 36% (aOR=1.36, 95% CI=1.01-1.81) increased odds among individuals with full-thickness tear. Conclusions: Higher BMI was associated with significantly higher odds of muscle atrophy in patiens with rotator cuff tears. More study is needed to unders1tand why and how this relationship exists, as well as whether interventions to reduce BMI may help improve outcomes for these patients. Level of Evidence: III.

Complications in brief: Arthroscopic partial meniscectomy.

Arthroscopic partial meniscectomy can be complicated by excessive resection, damage to articular cartilage, neurovascular injury, persistent drainage from portals, and infection; the procedure can be rendered more difficult, and the outcome less certain, if the surgeon fails to recognize concomitant injuries, malpositions the portals, or misidentifies the components of a meniscus tear. We review the problems that can occur as a result of errors made before, during, and after surgery.

Three osteochondritis dissecans lesions in one knee: a case report.

BACKGROUND: Osteochondritis dissecans (OCD) has been defined as a localized process in which a focus of subchondral bone and adjacent articular cartilage separates from the surrounding bone. With the knee being the most common location for OCD development and the propensity for this lesion to be found in those who participate in sports, a repetitive microtrauma hypothesis for its cause has gained favor. However, the cause of OCD remains controversial, as does the most appropriate treatment for the varying degrees of OCD lesions. CASE DESCRIPTION: We present a unique case of three OCD lesions in one knee. The patient was a young, athletic boy who developed three separate OCD lesions in his right knee over the course of 4 years. Temporally, the OCD lesions developed first in the lateral femoral condyle, then in the medial femoral condyle, and finally in the trochlea. LITERATURE REVIEW: Our literature review yielded a few reports of bicondylar OCD lesions. We identified no previous reports of three separate OCD lesions found in a single joint. PURPOSES AND CLINICAL RELEVANCE: This report illustrates how a uniquely affected knee with three OCD lesions was treated in three different ways with resolution of symptoms. Each of the OCD lesions was evaluated individually and treatment for each based on the severity of the lesion from the physical examination, imaging studies, and arthroscopic findings.

Drilling juvenile osteochondritis dissecans: retro- or transarticular?

BACKGROUND: Early diagnosis and successful treatment of juvenile osteochondritis dissecans (JOCD) is essential in preventing articular degeneration at a young age. Surgical treatment of stable JOCD lesions failing nonoperative treatment involves retroarticular or transarticular drilling to induce revascularization and healing. Multiple case series report high healing rates and infrequent complications for both retroarticular and transarticular drilling modalities; however, it is unclear from these individual reports whether one mode of drilling provides higher healing rates. QUESTIONS/PURPOSES: We asked whether transarticular or retroarticular drilling of stable JOCD lesions results in differing patient-oriented outcomes, rates of radiographic healing, time to radiographic healing, and complication rates. METHODS: We systematically reviewed the short-term clinical outcomes of retroarticular and transarticular drilling of stable OCD lesions. PubMed and additional sources identified 65 studies; 12 studies met inclusion criteria. RESULTS: Heterogeneity and quality of studies limited review to qualitative analysis. No clear differences were seen in patient-oriented outcomes after treatment with either drilling modality. Radiographic healing for JOCD lesions drilled retroarticularly occurred in 96 of 111 (86%) lesions in an average of 5.6 months. Transarticular drilling of JOCD lesions resulted in 86 of 94 (91%) lesions healing by radiography in an average of 4.5 months. No complications were reported for either drilling modality. CONCLUSIONS: Retroarticular and transarticular drilling of stable lesions results in comparable short-term patient-oriented outcomes and radiographic healing. Further high-quality comparative studies are required to adequately compare drilling modalities, clearly define radiographic healing, and patient-oriented outcomes after nonoperative treatment.

Osteochondritis dissecans knee histology studies have variable findings and theories of etiology.

BACKGROUND: Although many etiological theories have been proposed for osteochondritis dissecans (OCD), its etiology remains unclear. Histological analysis of the articular cartilage and subchondral bone tissues of OCD lesions can provide useful information about the cellular changes and progression of OCD. Previous research is predominantly comprised of retrospective clinical studies from which limited conclusions can be drawn. QUESTIONS/PURPOSES: The purposes of this study were threefold: (1) Is osteonecrosis a consistent finding in OCD biopsy specimens? (2) Is normal articular cartilage a consistent finding in OCD biopsy specimens? (3) Do histological studies propose an etiology for OCD based on the tissue findings? METHODS: We searched the PubMed, Embase, and CINAHL databases for studies that conducted histological analyses of OCD lesions of the knee and identified 1560 articles. Of these, 11 met our inclusion criteria: a study of OCD lesions about the knee, published in the English language, and performed a histological analysis of subchondral bone and articular cartilage. These 11 studies were assessed for an etiology proposed in the study based on the study findings. RESULTS: Seven of 11 studies reported subchondral bone necrosis. Four studies reported normal articular cartilage, two studies reported degenerated or irregular articular cartilage, and five studies found a combination of normal and degenerated or irregular articular cartilage. Five studies proposed trauma or repetitive stress and two studies proposed poor blood supply as possible etiologies. CONCLUSIONS: We found limited research on histological analysis of OCD lesions of the knee. Future studies with consistent methodology are necessary to draw major conclusions about the histology and progression of OCD lesions. Inconsistent histologic findings have resulted in a lack of consensus regarding the presence of osteonecrosis, whether the necrosis is primary or secondary, the association of cartilage degeneration, and the etiology of OCD. Such studies could use a standardized grading system to allow better comparison of findings.

Efficacy and degree of bias in knee injury prevention studies: a systematic review of RCTs.

BACKGROUND: Knee injury prevention programs have been developed to address the epidemic of knee injuries in young athletes. These programs include exercises that focus on balance, proprioception, and neuromuscular control. Some studies have suggested such specialized exercise programs may reduce the risk of knee injury. QUESTIONS/PURPOSES: We conducted a systematic review of randomized controlled trials (RCTs) of knee injury prevention programs and evaluated the risks of bias in these studies. METHODS: We performed a systematic search using MEDLINE (from 1966), CINAHL (from 1982), Cochrane (CENTRAL), and EMBASE (from 1974) in April 2011. The searches were limited to RCTs. Two reviewers independently assessed the internal validity of the included studies using the van Tulder critical appraisal tool for RCTs. Authors were contacted when internal validity was unclear in the methodology. Ten Level I studies (RCTs) met the inclusion criteria. The average risk of bias score for these studies was 7 of 11 (range, 5-10). RESULTS: Two of the 10 studies reported a reduction in knee injuries. Of the three studies that provided ACL injuries as an outcome measure, none showed a reduction in overall ACL injury. CONCLUSIONS: Current evidence suggests most (eight of 10) well-designed RCTs show no difference of treatment benefit. Perhaps refinements of interventions may lead to a reduction in knee and ACL injuries in future trials. Limitations in the number and heterogeneity of currently published RCTs of injury prevention programs place restraints on quantifying intervention efficacy with a meta-analytic approach. Future research articles should more clearly describe the different elements of their methodology, consistent with the standards set forth by the CONSORT statement.

Effectiveness of physical therapy in treating atraumatic full-thickness rotator cuff tears: a multicenter prospective cohort study.

PURPOSE: To assess the effectiveness of a specific nonoperative physical therapy program in treating atraumatic full-thickness rotator cuff tears using a multicenter prospective cohort study design. MATERIALS AND METHODS: Patients with atraumatic full-thickness rotator cuff tears who consented to enroll provided data via questionnaire on demographics, symptom characteristics, comorbidities, willingness to undergo surgery, and patient-related outcome assessments (Short Form 12 score, American Shoulder and Elbow Surgeons score, Western Ontario Rotator Cuff score, Single Assessment Numeric Evaluation score, and Shoulder Activity Scale). Physicians recorded physical examination and imaging data. Patients began a physical therapy program developed from a systematic review of the literature and returned for evaluation at 6 and 12 weeks. At those visits, patients could choose 1 of 3 courses: (1) cured (no formal follow-up scheduled), (2) improved (continue therapy with scheduled reassessment in 6 weeks), or (3) no better (surgery offered). Patients were contacted by telephone at 1 and 2 years to determine whether they had undergone surgery since their last visit. A Wilcoxon signed rank test with continuity correction was used to compare initial, 6-week, and 12-week outcome scores. RESULTS: The cohort consists of 452 patients. Patient-reported outcomes improved significantly at 6 and 12 weeks. Patients elected to undergo surgery less than 25% of the time. Patients who decided to have surgery generally did so between 6 and 12 weeks, and few had surgery between 3 and 24 months. CONCLUSION: Nonoperative treatment using this physical therapy protocol is effective for treating atraumatic full-thickness rotator cuff tears in approximately 75% of patients followed up for 2 years.

Does the Choice of Acellular Scaffold and Augmentation With Bone Marrow Aspirate Concentrate Affect Short-term Outcomes in Cartilage Repair? A Systematic Review and Meta-analysis.

BACKGROUND: Matrix-induced chondrogenesis (MIC) is a promising treatment option for critical-size cartilage lesions of the knee; however, there exists substantial heterogeneity in the choice of acellular scaffold matrix for MIC cartilage repairs. HYPOTHESIS: The choice of acellular matrix will not affect patient outcomes after MIC cartilage repair procedures, and the addition of concentrated bone marrow aspirate (cBMA) will improve short-term patient outcomes regardless of matrix choice. STUDY DESIGN: Meta-analysis; Level of evidence, 4. METHODS: Studies were stratified by matrix type: multilayered, single layered, and gel based. Continuous outcomes were analyzed with pairwise meta-analysis using the inverse variance model with random effects applied. Binary outcomes were analyzed as pooled proportions in a single-arm fashion; after which, reconstruction of relative risks (RRs) with confidence intervals was performed using the Katz logarithmic method. RESULTS: A total of 876 patients were included: 469 received multilayered bioscaffolds; 238, gel-based scaffolds; and 169, single-layered scaffolds. The mean age of patients was 36.2 years (95% CI, 33.9 to 38.4), while the mean lesion size was 3.91 cm2 (95% CI, 3.40 to 4.42). The weighted mean follow-up was 23.8 months (95% CI, 20.1 to 27.6). Multilayered bioscaffolds were most effective at improving visual analog scale scores (P = .03; weighted mean difference [WMD], -4.44 [95% CI, -4.83 to -4.06]; P < .001). There were significantly lower risks of incomplete defect filling for gel-based scaffolds when compared with multilayered scaffolds (RR, 0.78 [95% CI, 0.69 to 0.88]; P < .001) and single-layered scaffolds (RR, 0.58 [95% CI, 0.41 to 0.81]; P = .001). Augmentation with cBMA further improved clinical scores across all scaffolds, with significant improvements in Tegner score (P = .02), while decreasing incomplete defect filling rates as well. There was significantly greater improvement in visual analog scale scores (P = .01) for single-layered scaffolds with cBMA augmentation (WMD, -4.88 [95% CI, -5.38 to -4.37]; P < .001) as compared with single-layered scaffolds without cBMA augmentation (WMD, -4.08 [95% CI, -4.46 to -3.71]; P < .001). All significant improvements were below their respective minimum clinically important differences. CONCLUSION: While cartilage repair with acellular scaffolds provides significant improvements in pain and function for patients, there is insufficient clinical evidence to suggest which scaffold material is the most superior in influencing such improvements. The enhancement of cartilage repair procedures with cBMA may provide further functional improvements and improve defect filling; however, more long-term evidence is required to evaluate the effects.

Linguistic Analysis Identifies Emergent Biomaterial Fabrication Trends for Orthopaedic Applications.

The expanse of publications in tissue engineering (TE) and orthopedic TE (OTE) over the past 20 years presents an opportunity to probe emergent trends in the field to better guide future technologies that can make an impact on musculoskeletal therapies. Leveraging this trove of knowledge, a hierarchical systematic search method and trend analysis using connected network mapping of key terms is developed. Within discrete time intervals, an accelerated publication rate for anatomic orthopedic tissue engineering (AOTE) of osteochondral defects, tendons, menisci, and entheses is identified. Within these growing fields, the top-listed key terms are extracted and stratified into evident categories, such as biomaterials, delivery method, or 3D printing and biofabrication. It is then identified which categories decreased, remained constant, increased, or emerged over time, identifying the specific emergent categories currently driving innovation in orthopedic repair technologies. Together, these data demonstrate a significant convergence of material types and descriptors used across tissue types. From this convergence, design criteria to support future research of anatomic constructs that mimic both the form and function of native tissues are formulated. In summary, this review identifies large-scale trends and predicts new directions in orthopedics that will define future materials and technologies.

Evaluation of surgical fixation methods for the implantation of melt electrowriting-reinforced hyaluronic acid hydrogel composites in porcine cartilage defects.

The surgical repair of articular cartilage remains an ongoing challenge in orthopedics. Tissue engineering is a promising approach to treat cartilage defects; however, scaffolds must (i) possess the requisite material properties to support neocartilage formation, (ii) exhibit sufficient mechanical integrity for handling during implantation, and (iii) be reliably fixed within cartilage defects during surgery. In this study, we demonstrate the reinforcement of soft norbornene-modified hyaluronic acid (NorHA) hydrogels via the melt electrowriting (MEW) of polycaprolactone to fabricate composite scaffolds that support encapsulated porcine mesenchymal stromal cell (pMSC, three donors) chondrogenesis and cartilage formation and exhibit mechanical properties suitable for handling during implantation. Thereafter, acellular MEW-NorHA composites or MEW-NorHA composites with encapsulated pMSCs and precultured for 28 days were implanted in full-thickness cartilage defects in porcine knees using either bioresorbable pins or fibrin glue to assess surgical fixation methods. Fixation of composites with either biodegradable pins or fibrin glue ensured implant retention in most cases (80%); however, defects treated with pinned composites exhibited more subchondral bone remodeling and inferior cartilage repair, as evidenced by micro-computed tomography (micro-CT) and safranin O/fast green staining, respectively, when compared to defects treated with glued composites. Interestingly, no differences in repair tissue were observed between acellular and cellularized implants. Additional work is required to assess the full potential of these scaffolds for cartilage repair. However, these results suggest that future approaches for cartilage repair with MEW-reinforced hydrogels should be carefully evaluated with regard to their fixation approach for construct retention and surrounding cartilage tissue damage.

Transarticular Versus Retroarticular Drilling of Stable Osteochondritis Dissecans of the Knee: A Prospective Multicenter Randomized Controlled Trial by the ROCK Group.

BACKGROUND: When stable osteochondritis dissecans (OCD) lesions of the femoral condyle in a skeletally immature patient fail to heal with nonoperative methods, the standard of care treatment is condylar OCD drilling. Two primary OCD drilling techniques have been described, but no prospective studies have compared their relative effectiveness. PURPOSE/HYPOTHESIS: The purpose of this study was to compare the healing and function after transarticular drilling (TAD) with that after retroarticular drilling (RAD). It was hypothesized that there would be no difference in rate or time to healing, rate or time to return to sports, patient-reported outcomes (PROs), or secondary OCD-related surgery. STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1. METHODS: Skeletally immature patients with magnetic resonance imaging-confirmed stable OCD lesions of the medial femoral condyle who did not demonstrate substantial healing after a minimum of 3 months of nonoperative treatment were prospectively enrolled by 1 of 17 surgeon-investigators at 1 of 14 centers. Patients were randomized to the TAD or RAD group. Tourniquet time, fluoroscopy time, and complications were compared between the treatment groups. Postoperatively, serial radiographs were obtained every 6 weeks to assess healing, and PROs were obtained at 6 months, 12 months, and 24 months. RESULTS: A total of 91 patients were included, consisting of 51 patients in the TAD and 40 patients in the RAD group, who were similar in age, sex distribution, and 2-year PRO response rate. Tourniquet time and fluoroscopy time were significantly shorter with TAD (mean, 38.1 minutes and 0.85 minutes, respectively) than RAD (mean, 48.2 minutes and 1.34 minutes respectively) (P = .02; P = .004). In the RAD group, chondral injury from K-wire passage into the intra-articular space was reported in 9 of 40 (22%) patients, but no associated postoperative clinical sequelae were identified in these patients. No significant differences between groups were detected in follow-up Pediatric-International Knee Documentation Committee, Lysholm, Marx Activity Scale, or Knee injury and Osteoarthritis Outcome Score Quality of Life scores. Healing parameters were superior at 6 months and 12 months in the TAD group, compared with the RAD group, and secondary OCD surgery occurred in 4% of patients who underwent TAD and 10% of patients who underwent RAD (P = .40). Patients in the TAD group returned to sports earlier than those in the RAD group (P = .049). CONCLUSION: TAD showed shorter operative time and fluoroscopy time and superior healing parameters at 6 and 12 months, but no differences were seen in 24-month healing parameters or PROs at all follow-up time points, when compared with RAD. REGISTRATION: NCT01754298 (ClinicalTrials.gov identifier).

Meniscal and Articular Cartilage Predictors of Outcome After Revision ACL Reconstruction: A 6-Year Follow-up Cohort Study.

BACKGROUND: Meniscal and chondral damage is common in the patient undergoing revision anterior cruciate ligament (ACL) reconstruction. PURPOSE: To determine if meniscal and/or articular cartilage pathology at the time of revision ACL surgery significantly influences a patient's outcome at 6-year follow-up. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients undergoing revision ACL reconstruction were prospectively enrolled between 2006 and 2011. Data collection included baseline demographics, surgical technique, pathology, treatment, and scores from 4 validated patient-reported outcome instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx Activity Rating Scale. Patients were followed up at 6 years and asked to complete the identical set of outcome instruments. Regression analysis assessed the meniscal and articular cartilage pathology risk factors for clinical outcomes 6 years after revision ACL reconstruction. RESULTS: An overall 1234 patients were enrolled (716 males, 58%; median age, 26 years). Surgeons reported the pathology at the time of revision surgery in the medial meniscus (45%), lateral meniscus (36%), medial femoral condyle (43%), lateral femoral condyle (29%), medial tibial plateau (11%), lateral tibial plateau (17%), patella (30%), and trochlea (21%). Six-year follow-up was obtained on 79% of the sample (980/1234). Meniscal pathology and articular cartilage pathology (medial femoral condyle, lateral femoral condyle, lateral tibial plateau, trochlea, and patella) were significant drivers of poorer patient-reported outcomes at 6 years (IKDC, KOOS, WOMAC, and Marx). The most consistent factors driving outcomes were having a medial meniscal excision (either before or at the time of revision surgery) and patellofemoral articular cartilage pathology. Six-year Marx activity levels were negatively affected by having either a repair/excision of the medial meniscus (odds ratio range, 1.45-1.72; P≤ .04) or grade 3-4 patellar chondrosis (odds ratio, 1.72; P = .04). Meniscal pathology occurring before the index revision surgery negatively affected scores on all KOOS subscales except for sports/recreation (P < .05). Articular cartilage pathology significantly impaired all KOOS subscale scores (P < .05). Lower baseline outcome scores, higher body mass index, being a smoker, and incurring subsequent surgery all significantly increased the odds of reporting poorer clinical outcomes at 6 years. CONCLUSION: Meniscal and chondral pathology at the time of revision ACL reconstruction has continued significant detrimental effects on patient-reported outcomes at 6 years after revision surgery.

Classification Systems for Knee Osteochondritis Dissecans: A Systematic Review.

OBJECTIVE: Aim of this systematic review was to describe all classification systems for knee osteochondritis dissecans (OCD) lesions, evaluating their accuracy and reliability, as well as their use in the literature on knee OCD. DESIGN: A systematic review of the literature was performed in July 2021 on PubMed, WebOfScience, and Cochrane Collaboration (library) to describe all published classification systems for knee OCD lesions and quantify the use of these classifications in the literature. RESULTS: Out of 1,664 records, 30 studies on 33 OCD classifications systems were identified, describing 11 radiographic, 13 MRI, and 9 arthroscopic classifications. The search included 193 clinical studies applying at least one OCD classification, for a total of 7,299 knee OCD cases. Radiographic classifications were applied to 35.8%, MRI to 35.2%, and arthroscopic classifications to 64.2% of the included studies. Among these, in the last two decades, the International Cartilage Repair Society's (ICRS) arthroscopic classification was the most described approach in studies on knee OCD. Overall, there is a lack of data on accuracy and reliability of the available systems. CONCLUSIONS: Several classifications are available, with ICRS being the most used system over the time period studied. Arthroscopy allows to confirm lesion stability, but noninvasive imaging approaches are the first line to guide patient management. Among these, radiographic classifications are still widely used, despite being partially superseded by MRI, because of its capability to detect the earliest disease stages and to distinguish stable from unstable lesions, and thus to define the most suitable conservative or surgical approach to manage patients affected by knee OCD. LEVEL OF EVIDENCE: Systematic review, level IV.