Osteochondritis Dissecans Of Knee Research Articles

Clinical Outcomes and Return-to-Sport Rates following Fragment Fixation Using Hydroxyapatite/Poly-L-Lactate Acid Threaded Pins for Knee Osteochondritis Dissecans: A Case Series.

Osteochondritis dissecans (OCD) of the knee is an uncommon injury in young active patients. There is currently a lack of knowledge regarding clinical outcomes and return-to-sport rates after fragment fixation surgery using hydroxy appetite poly-L-lactic acid (HA/PLLA) threaded pins for knee OCD among athletes. Our purpose was to investigate the clinical outcomes and return-to-sport rates following osteochondral fragment fixation using HA/PLLA pins for the treatment of knee OCD lesions among athletes. A total of 45 patients were retrospectively reviewed. In total, 31 patients were excluded, and 14 patients were included. Pre- and postoperative patient-reported outcome scores (PROSs), including the International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcome Scale (KOOS), were compared. In addition, patients were categorized into four groups according to postoperative sports status: higher, same, lower than preinjury, or unable to return to sports. The mean age was 14.4 years (SD 1.67). All patients were male. All PROSs significantly improved at 6, 12, and 24 months postsurgery compared to presurgery. 50% of the patients returned to sports at the same or higher level after surgery. Fragment fixation using HA/PLLA pins leads to favorable clinical outcome scores and high return-to-sport rates in the treatment of athletes with knee OCD.

Osteochondritis Dissecans Lesions of the Knee: Evidence-Based Treatment.

Osteochondritis dissecans (OCD) of the knee is a potentially disabling condition in adolescent and young adults, which is likely multifactorial in origin. In recent years, there have been notable improvements in identification and treatment. Clinical presentation varies based mostly on OCD lesion stability. Patients with stable lesions generally present with vague knee pain and altered gait while mechanical symptoms and effusion are more common with unstable lesions. Lesions most commonly occur on the lateral aspect of the medial femoral condyle in patients aged 10 to 20 years. Magnetic resonance imaging is vital to diagnose and predict clinical treatment, which is largely based on stability of the fragment. Conservative treatment of stable lesions in patients with open physis is recommended with protected weight-bearing and gradual progression of activities over the course of 3 to 6 months. Stable OCD lesions which failed a nonsurgical course can be treated with transarticular or retrograde drilling while unstable lesions usually require fixation, autologous chondrocyte implantation (ACI), osteochondral autograft transfer (OATS), or osteochondral allograft transplantation. This review highlights the most current understanding of knee OCD lesions and treatment options with the goal of optimizing outcomes in this difficult pathology.

Patella and Trochlea Osteochondritis Dissecans: Demographics and Treatment Paradigms.

Previous research on patellar and trochlear groove osteochondritis dissecans (OCD) is limited by small sample sizes. This study aims to describe the presentation of patients with OCD lesions of the patella and trochlea and characterize the outcomes of operative and nonoperative treatments. This retrospective cohort study identified all patients from a single institution from 2008 to 2021 with patellar and/or trochlear OCD lesions. Patients were excluded from the study if surgical records were unavailable or if the patient had knee surgery for a different injury at index surgery or in the 12 months postoperative. Minimum follow-up was 12 months. Outcomes included a return to sports (RTS), pain resolution, radiographic healing, and treatment "success" (defined as full RTS, complete pain resolution, and full healing on imaging). A total of 68 patients (75 knees) were included-45 (60%) with patellar OCD and 30 (40%) with trochlear. Of the patients, 69% were males. The median age at knee OCD diagnosis was 14 years. At the final follow-up, 62% of knees (n = 44) recovered sufficiently to allow a full RTS and 54% of knees (n = 39) had full pain resolution. Of the 46 knees with radiographic imaging at least 1 year apart, 63% had full healing of the lesion. There was no significant difference in RTS, pain resolution, radiographic healing, or overall success when comparing treatments. This study provides valuable epidemiologic demographic and outcome data regarding the scarcely reported patellar and trochlear OCD. While over half of patients fully returned to sports and reported full pain resolution, a large proportion continued to experience symptoms over a year after presentation. Future research should aim to better define the treatment algorithms for these OCD subtypes. Level III.

Epiphyseal cartilage vascular architecture at the distal humeral osteochondritis dissecans predilection site in juvenile pigs.

Failure of endochondral ossification due to interruption of the vascular supply to the epiphyseal cartilage is a critical step in the development of osteochondritis dissecans (OCD). Herein we describe the vascular architecture of the distal humeral epiphyseal cartilage in pigs and identify characteristic features that have been associated with sites predisposed to OCD development across species. Distal humeral specimens were harvested from pigs (n = 5, ages = 1, 10, 18, 30, and, 42 days old) and imaged at 9.4T magnetic resonance imaging (MRI) using a 3D gradient recalled echo sequence. The MRI data were processed using a quantitative susceptibility mapping (QSM) pipeline to visualize the vascular architecture. Specimens were also evaluated histologically to identify the presence of ischemic epiphyseal cartilage necrosis (osteochondrosis [OC]-latens) and associated failure of endochondral ossification (OC-manifesta). The QSM data enabled visualization of two distinct vascular beds arising from the perichondrium at the lateral and medial aspects of the distal humeral epiphysis. Elongated vessels originating from these beds coursed axially to supply the lateral and medial thirds of epiphyseal cartilage. At 18 days of age and older, a shift from perichondrial to transosseous blood supply was noted axially, which appeared more pronounced on the lateral side. This shift coincided with histologic identification of OC-latens (30- and 42-day-old specimens) and OC-manifesta (18- and 42-day-old specimens) lesions in the corresponding regions. The vascular anatomy and its evolution at the distal humeral epiphysis closely resembles that previously reported at predilection sites of knee OCD, suggesting a shared pathophysiology between the knee and elbow joints.

Efficacy of the pridie drilling technique in knee osteochondritis dissecans among children and young adults: follow-up of 41 cases.

This study aims to examine whether Pridie drilling, a form of bone marrow stimulation, can expedite the healing process and enable a faster return to sports activity in patients with knee Osteochondritis dissecans (OCD). The primary objective is to assess the effectiveness of Pridie drilling in stable OCD lesions that do not respond to non-operative treatment, by evaluating the absence of painful symptoms 6months after the procedure. Secondary objectives include evaluating radiographic reconstruction 6months post-surgery and determining the time it takes to resume sports participation. This single-center retrospective study included all cases of stable OCD in the knee that underwent anterograde chondral drilling between 2008 and 2020. Diagnosis of OCD was established using knee radiographs, and the surgical technique involved multiple multidirectional subchondral drilling. Treatment efficacy was defined by the absence of painful symptoms for 6months postoperatively. A total of 41 knees were included in the study, and no complications were observed before or after surgery. At 6months postoperatively, 32 knees (78%) showed complete resolution of symptoms. Complete radiographic reconstruction was observed in 66% of cases. Asymptomatic patients at 6months returned to sports activity of similar intensity to that practiced previously in an average time of 7.9months; while, patients who were symptomatic at 6months returned in an average time of 16.5months. This study provides evidence supporting the short-term efficacy of anterograde chondral drilling in stable lesion of OCD in children and adolescents after failed functional treatment. Level III (retrospective cohort study).

Evaluating the Etiology of Osteochondritis Dissecans of the Knee: The Role of the Articular-Epiphyseal Cartilage Complex

Introduction: In pathologic form, osteochondritis dissecans (OCD) is a focal end-stage disease of articular cartilage. Comparative anatomy studies have demonstrated that injury to epiphyseal anlage cartilage leads to development of OCD in many species, whereas in humans, the exact etiology is suspected but remains unknown. A potential candidate is the articular-epiphyseal cartilage complex, and our hypothesis is that injury at the junction between the epiphyseal anlage cartilage and the articular cartilage results in childhood OCD.Methods: A retrospective, two-institution assessment of children with magnetic resonance imaging (MRI) of the affected knee before the onset of an OCD lesion was performed. Demographics were recorded, including the history of why each initial pre-OCD MRI (Index-MRI) was obtained. MRI measurements were made on the Index-MRI as well as the subsequent OCD-MRI of the epiphyseal ossification length (Growth), marrow edema, the distance of lesion from physis (Lesion Position), and the distance from articular surface (OCD Depth). Comparisons over time were then calculated.Results: Six children (seven knees) were identified with an Index-MRI (Pre-OCD development) obtained at median age 11.6 years and OCD-MRI obtained at a median of 1.9 years later. ‘Growth' occurred in at least one dimension for all children (sagittal MRI, p=0.018). As a group, the ‘Lesion Position' did not change significantly in any plane but two demonstrated continued ossification of the epiphysis and one demonstrated bone necrosis. As a group, the ‘OCD Depth' was significantly different (coronal plane, p=0.029 and sagittal plane, p=0.026) over time, with all lesions increasing their depth (since none existed on the Index-MRI).Discussion: Even though the articular-epiphyseal cartilage complex appeared to be involved with the etiology of knee OCD in this limited series, we found significant variation in the response to a presumed injury with either halted progression, continued ossification, or even regression of ossification adjacent to the OCD. This variation either indicates that there is a multimodal etiology, or that the articular-epiphyseal cartilage complex inconsistently responds to injury. This may explain the inconsistent response to management and calls for further basic science studies to ascertain the exact location of injury in the human articular-epiphyseal cartilage complex.Level of Evidence: III, Retrospective Cohort StudyKey Concepts•Osteochondritis dissecans may have more than one etiology that leads to a similar pathology pattern at the time of presentation.•Future study will be important to identify when certain patterns of progression are present that may indicate one management modality over another one.•Understanding the variation in OCD etiology may have repercussions regarding animal model development.

Paper 53: A Predictive Model for Mobile vs. Immobile Osteochondritis Dissecans Lesions of the Knee

Objectives: Osteochondritis dissecans (OCD) of the knee is a focal idiopathic alteration of subchondral bone and/or its precursor with risk for instability and disruption of adjacent cartilage that may result in premature osteoarthritis. Treatment options vary depending on multiple patient and lesion characteristics, including lesion mobility. Recent multicenter studies helped develop the ROCK (Research on Osteochondritis Dissecans of the Knee) Arthroscopy Classification of OCD lesions of the knee. To advance the clinical utility of the classification system, this current investigation aimed to develop a simple, clinical outcomes-based model that could be used to differentiate lesion mobility. We hypothesized that a multivariable model including patient demographics and physical examination findings at clinical presentation would predict the arthroscopically confirmed mobility status of the OCD lesion with high sensitivity and specificity. Methods: Patient data for the predictive modeling came from a multi-center national prospective cohort of patients with osteochondritis dissecans of the knee. Inclusion criteria included patients < 19 years of age, operatively treated OCD of the medial or lateral femoral condyle, and appropriate preoperative and intra-operative data. Demographic, preoperative physical examination, and radiographic data were considered independent predictors in the model. Multivariable logistic regression analysis using stepwise model selection was used to determine factors associated with the likelihood of a mobile versus an immobile lesion. Receiver operating characteristic (ROC) curve analyses were used to dichotomize relevant variables for a final predictive model. The authors reviewed the relevant variables for clinical utility. A 75% partition of the data was used for model training, and 25% was held out for model validation testing. Quantitative model fit statistics were computed using the hold-out data, including sensitivity, specificity, and the area under the ROC curve (AUC), along with the corresponding 95% confidence interval (CI). Results: 479 patients in the prospective cohort who were less than 19 years of age and had surgical treatment of a knee OCD lesion were reviewed. 407 patients had usable preoperative and intra- operative data, including 235 immobile and 172 mobile lesions. Mean chronologic age of the 407 patients was 13.7 (2.2 SD) years with 62% male. Mean height was 63.6 (5.3 SD) inches and 129.5 (40.4 SD) lbs. Mean BMI was 22 (5.1 SD). 21% of the total cohort presented with an effusion on physical examination and 20% presented with reduced range of motion either in flexion or extension compared with their contralateral knee. Patient demographics (age, sex, age, height, weight, BMI) and physical examination findings of relative loss of motion (ROM) compared to unaffected knee and presence of effusion on examination were primary variables of interest. 88 patients were excluded because of missing partial data for modeling. 319 patients had complete data for modeling (training data 75%; n=239; validation data 25%; n=80). Using the training dataset, the multivariable analysis found that chronologic age ≥ 14 years, effusion on physical examination (p=0.004), and any loss of ROM on physical examination (p=0.004) increased the likelihood of mobile lesion controlling for male sex (p=0.42) and weight >120lbs (p=0.23). In the 25% holdout sample (n=80), this model yielded a sensitivity of 83%, a specificity of 75%, and an AUC of 0.86 (95% CI, 0.78-0.94). The final predictive model was created from dichotomized relevant variables (Figure 1). Conclusions: This predictive model for knee OCD lesions indicates a patient presenting with chronologic age ≥ 14 years, evidence of a knee effusion on physical examination, and reduced ROM relative to the contralateral knee is between 90% and 95% likely to have a mobile lesion compared to an immobile lesion using the ROCK Arthroscopy Classification. The ability to predict the mobility of knee OCD lesions before surgical intervention can facilitate improved surgical planning and more relevant communication with families regarding the procedures that will be required. Specifically, this can aid in distinguishing between less invasive interventions such as drilling versus more invasive procedures such as OCD fixation and salvage.

Poster 271: Descriptive Epidemiology of Surgically Treated Osteochondritis Dissecans of the Knee: Lessons Learned from a Large Pediatric Orthopedic Center

Objectives: Osteochondritis dissecans (OCD) lesions of the knee affect roughly 10-25 per 100,000 patients ages 6-19. This condition, which can cause pain, discomfort, and lead to arthritic changes, can be especially challenging for younger patients. The etiology is still not fully understood and treatment strategies, both non-operative and operative, can vary among clinicians. Although previous studies have begun to describe the prevalence and patterns of knee OCD lesions, there are very limited epidemiologic investigations of these lesions in surgically treated patients or from pediatric orthopedic centers at children’s hospitals. Methods: Patients ages 0-18 who underwent operative treatment for OCD lesions of the knee from January 2015 to December 2021 at a large pediatric orthopedic center were identified using Current Procedural Terminology (CPT) codes. Patients who underwent exclusively nonoperative management of their OCD were excluded. Demographic data, growth plate status, sports participation, symptoms, lesions characteristics, and operative data were gleaned from patient charts. Descriptive statistical analysis was performed for outcomes of interest. Results: A total of 375 knees in 354 patients across 5 surgeons were operated on; 64.4% were male. There was a mean age of 13.91 years (range 8.3-18.9 years), and 77.6% of patients had open growth plates. The most common sports played were basketball for males (28.6% of cases) and soccer for females (31.7% of cases). 55.7% of lesions were on the right with 22.7% of patients having bilateral OCD. Most lesions were on the medial femoral condyle (63.2%) with other locations including the lateral femoral condyle (17.6%), patella (10.4%), trochlea (8.3%), or tibial plateau (0.5%). The average time to surgery from initial presentation was 4.8 months (range 0.03-59.83 months) with 61.6% of patients having undergone some form of conservative treatment prior to surgery. The most common indication for surgery was failed healing response to conservative treatment (46.9% of cases). After diagnostic arthroscopy, patients either underwent drilling (67.7%), fixation with screws, sutures, or chondral darts (24.2%), grafting (33.3%), bone stimulation (14.1%), or cartilage biopsy for two-stage procedure (6.1%) (Table 1). 32% had some combination of surgical interventions. Transarticular drilling was the most common technique and the proximal tibia was the most common source of autograft. 19.4% of cases had additional procedures performed at the time of OCD repair. Conclusions: Overall, there is great variability in the presentation and management of surgically treated OCD lesions of the knee in pediatric and adolescent patients. While most patients trialed conservative therapy prior to operative treatment, there is a large cohort of patients who go to surgery sooner for other indications such as instability or additional injuries requiring operative repair. Although drilling is the most common form of fixation, the high prevalence of grafting suggests more lesions to be unstable than initially thought. [Table: see text]

Long-Term Outcome and Athletic Level following Operative Treatment for Osteochondritis Dissecans of the Knee in Pediatric and Adolescent Patients.

Research on the long-term outcomes following surgical therapy for osteochondritis dissecans (OCD) of the knee is scarce. A single-center retrospective cohort study was conducted to investigate surgically treated patients for knee OCD between 1993 and 2007. A total of 37 patients with an average follow-up duration of 14 years (range 8-18) were in the final cohort. IKDC and Lysholm scores were assessed. The duration and types of sport activity were reported. Long-term results were compared with existing midterm data. Knee scores showed a very good outcome with a mean of 91.3 in the IKDC score and 91.7 in the Lysholm score. Compared to midterm outcomes, both IKDC (p = 0.028) and Lysholm scores (p = 0.01) improved on final follow-up. Patients with open physes showed a significantly better Lysholm score compared to patients with closed physes (p = 0.034). Defect localization and size did not influence the outcome, but a defect depth of <0.8 cm2 achieved significantly better scores than ≥0.8 cm2. Of all surgical interventions, refixation achieved the best outcome. Long-term results significantly improved compared to midterm results with a follow-up of 40 months (p = 0.01). Thirty-six out of 37 patients were physically active, with 56% of sports being knee-straining activities. Long-term results following surgically treated OCD fragments show excellent function and a good athletic level. Patients with open physes potentially have better knee outcomes. Midterm results are sustainable and could improve further in the long term.

No difference in patient reported outcomes between cohorts undergoing lesion-specific surgery for osteochondritis dissecans of the knee

IntroductionThere is a paucity of data on patient reported outcome measures (PROMs) associated with surgical treatment of osteochondritis dissecans (OCD). As a result, preoperative patient and family counseling regarding expected outcomes is difficult. The purpose of this study was to compare pre-to post-operative changes in PROMs amongst cohorts of patients with OCD that underwent one of three lesion-specific surgical treatments: 1) transarticular drilling for stable lesions, 2) drilling and fixation for unstable lesions 3) grafting for unsalvageable lesions. MethodsThe electronic medical records of pediatric and adolescent patients with knee OCD, at a single institution between January 2017 and August 2019, were reviewed. Patients were categorized into one of three surgical groups, with initial determination confirmed at the time of surgery during diagnostic knee arthroscopy. Differences between groups were assessed with one-way analysis of variance (ANOVA). ResultsOf the 78 patients included in this study, 49 (62.8%) were male with a mean age of 13.5 ± 2.2 years. There was no significant difference between the surgical groups for baseline HSS Pedi-FABS (P = 0.58) or PROMIS Mobility (P = 0.47). There were no significant differences in PROMIS PI scores at baseline (P = 0.32), at latest follow-up (P = 0.72), or in interval change from baseline to follow-up (P = 0.42), between the three surgical groups. ConclusionLesion-specific surgical management of OCD led to similar improvements in PROMIS PI at a minimum of one-year follow-up. These results may better allow surgeons to reassure patients and families that outcomes are similar when lesions are treated through a lesion-specific algorithm. Level of evidenceLevel IV: Retrospective cohort study.

Low-Intensity Pulsed Ultrasonography Plus Arthroscopic Drilling Does Not Improve Bone Healing More Than Arthroscopic Drilling Alone in Pediatric Patients With Stable Osteochondritis Dissecans of the Knee

To determine whether adjuvant use of bone stimulation would improve the rate of healing in the operative management of stable osteochondritis dissecans (OCD) of the knee in pediatric patients. This retrospective matched case-control study was performed at a single tertiary care pediatric hospital between January 2015 and September 2018. Patients who underwent antegrade drilling for stable femoral condyle OCD with greater than 2 years' follow-up were included. Preference was for all to receive postoperative bone stimulation; however, some were denied because of insurance coverage. This enabled us to create 2 matched groups of those who received postoperative bone stimulation and those who did not. Patients were matched on skeletal maturity, lesion location, sex, and age at surgery. The primary outcome measure was the rate of healing of the lesions determined by postoperative magnetic resonance imaging measurements at 3 months. Fifty-five patients were identified who met the inclusion and exclusion criteria. Twenty patients from the bone stimulator group (BSTIM) were matched to 20 patients from the no bone stimulator group (NBSTIM). Mean age for BSTIM at surgery was 13.2 years ± 2.0 (range, 10.9-16.7) and for NBSTIM at surgery 12.9 years ± 2.0 (range, 9.3-17.3). At 2 years, 36 patients (90%) in both groups went on to clinical healing without further interventions. In BSTIM, there was a mean decrease of 0.9 (±1.8) mm in lesion on coronal width and 12 patients (63%) had overall improved healing; in NBSTIM there was a mean decrease of 0.8 (±3.6) mm in coronal width and 14 patients (78%) had improved healing. No statistical differences in the rate of healing were found between the 2 groups (P= .706). In antegrade drilling of stable knee OCD lesions in pediatric and adolescent patients, adjuvant bone stimulator use did not appear to improve radiographic or clinical healing. Level III, retrospective case-control study.

Increased lesion depth, higher body mass index and older age are risk factors for osteoarthritis during long-term follow-up in patients with osteochondritis dissecans of the knee

IntroductionTo report on the long-term prognosis of osteochondritis dissecans (OCD) patients regarding radiological and patient-reported outcomes and to analyze possible risk factors.Materials and methodsAll patients diagnosed with knee OCD between 2004 and 2014 with radiographic Kellgren–Lawrence (K–L) grades 0–2 at the time of diagnoses, ability to understand the language of the interview, and willingness to participate in the study were retrospectively reviewed. Current knee radiographs and the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire were prospectively collected between May 2020 and March 2021. The extent of osteoarthritis (OA) and KOOS questionnaire results were evaluated.Results90 patients (103 knees) with a mean age of 21 years (range 6–60) were included. The mean follow-up time was 12 years (range 7–20). 24 knees (23%) were treated conservatively, and 79 knees (77%) operatively. At the time of diagnoses, 90% of the patients had K–L grades of 0–1; during the follow-up period, 45% of the patients showed radiological progression of OA. Patient body mass index (BMI) (p = 0.004; 95% CI 0.25–0.29), age (p = 0.003; 95% CI 0.18–0.30), operative treatment (p = 0.0075; 95% CI 0.41–0.65) and lesion depth (p = 0.0007) were statistically significantly connected to K–L grade change. Patients with no progression in joint space narrowing had statistically significantly better overall KOOS scores (p = 0.03; 95% CI 0.77–0.88) than patients whose K–L grades worsened.ConclusionsDuring the long-term follow-up of 12 years, patients with knee OCD had good clinical results. Lac of radiological progression of cartilage degeneration was noted in 55% of the patients, regardless of treatment method. Lesion depth, higher BMI and older age were associated with the progression of OA. The progression of OA was related to a worsening of functional scores.Level of evidenceIV.

Knee osteochondritis dissecans-treatment technical aspects

Purpose and objectiveCurrent treatments of different stages of knee osteochondritis Dissecans (OCD) are depending on the age of the patients and the stability of the diseased osteochondral area. The purpose of this paper was to summarize the treatment alternatives in order to simplify the choice for the treating surgeon. Background and principle resultsOsteochondritis dissecans (OCD) of the knee is an idiopathic and local osteochondral abnormality that affects mainly children and adolescents with risk of loosening of osteochondral fragments. A good clinical result can be expected when the physes are still open, when the osteochondritis is small and when the osteochondritis can be assessed as stable by MRI. Unstable OCD lesions most often need to be treated operatively by different fixation methods and when the osteochondral cannot be refixated, different local chondral and osteochondral repairs are available to fill up the defect area to congruity Summary and major conclusionsThe final choice of which treatment to use is depending on fragment viability and forms. Viable fragments are refixated while poor quality fragments are removed followed by a local biological osteochondral repair. Such osteochondral resurfacing may be single bone marrow stimulation with or without scaffold augmentation or different cell seeded grafts.

Technologies for stimulation of the reparative processes in children with knee osteochondritis dissecans: A review

Dissecting osteochondritis of the knee joint, Koenigs disease is a disease of the knee joint that result in articular surface and osteoarthritis congruence. The disease incidence reaches 15% in the pathological knee joint structure in children. The comparative effectiveness of various treatment methods for children with Koenigs disease, from conservative therapy to orthobiological technologies, is a topical subject of discussion among specialists.&#x0D; The effectiveness of modern treatment methods for children with Koenigs disease has been evaluated and is the leading trend in the use of biotechnology for further experimental and clinical studies.&#x0D; The literature search was conducted in the electronic databases of PubMed, Web of Science, Scopus, MEDLINE, eLibrary, RSCI, and Cyberleninka, whereas 2300 references were analyzed, 283 articles were viewed, and 90 publications on orthopedics and biotechnology were selected for the review.&#x0D; Indications for conservative treatment in children with Koenigs disease are currently limited to stages III of the process. Surgical methods occupy a dominant position when pain relief and pathological focus regeneration stimulation are necessary. However, the long-term results of therapy indicate the replacement of the necrosis zone with coarse fibrous connective tissue, which is significantly inferior to hyaline cartilage in terms of biomechanical characteristics, which determines a high risk of developing osteoarthritis. The actively developing direction of orthobiology allows the use of a patients tissues to activate the processes of reparative regeneration with the relief of clinical manifestations and favorable immediate results.&#x0D; The focus of attention of researchers has shifted to the plane of orthobiological technologies following the established trends in regenerative medicine development, which provide a high proportion of favorable immediate interventional results. However, the limited number of publications and the lack of long-term results of therapy do not meet the criteria for demonstrative effectiveness of technologies.

Classification Systems for Knee Osteochondritis Dissecans: A Systematic Review.

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. 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. 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. 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. Systematic review, level IV.

Novel Mri Classification for Osteochondritis Dissecans of the Knee: A Validation Study

Background:A simpler three-category magnetic resonance imaging (MRI) classification system for osteochondritis dissecans (OCD) of the knee was recently shown to have comparable reliability to the existing five-category Hefti system. The validity and clinical utility of this simpler system as an alternative to the Hefti system has yet to be established.Hypothesis/Purpose:The purpose of this study was to assess whether a novel, simpler three-category MRI classification system for OCD of the knee demonstrates equal or better validity and correlates more strongly with treatment than the five-category Hefti classification.Methods:Demographic data and arthroscopic findings were collected from the medical and surgical records of 144 knees of children and adolescents with arthroscopically diagnosed knee OCD. MRI assessment of OCD lesions was conducted by two independent raters. Inter-rater reliability for novel and Hefti classifications was assessed by estimating weighted kappa (kw ). Agreement between MRI classification and arthroscopic findings was assessed by estimating kw coefficients. Classifications were dichotomized into 1,2 versus 3 for the novel system, and the sensitivity and specificity of classification was estimated as compared to arthroscopic findings. Correlation between arthroscopic classification and treatment type was assessed by estimating Spearman’s coefficient.Results:There was substantial interrater agreement with the proposed system’s ratings on MRI (kw =0.66; 955 CI=0.56-0.75) and moderate agreement for Hefti system’s ratings on MRI (kw =0.57; 955 CI=0.47-0.67) (Table 1). There was no difference detected in the agreement statistics for the proposed versus Hefti classifications (p=0.89). Binary agreement of the novel classification using dichotomous categories was slightly worse than the three-category classification. When 1&2s were combined, the agreement was moderate with k=0.41 (95% CI=0.25-0.58) and when 2&3s were combined, the agreement was fair with k=0.34 (95% CI=0.21-0.48). There was strong correlation between novel classification on arthroscopy with treatment type (r=0.85; 95% CI = 0.80-0.89) and between Hefti classification and treatment type (r=0.82; 95% CI = 0.75-0.86) (Table 2).Conclusion:The validity and clinical utility of the proposed three-category MRI classification system for knee OCD is comparable to that of the five-category Hefti system. This simpler classification system provides a foundation for the subsequent establishment of an operative treatment algorithm for knee OCD.Table 1.Summary of MRI and arthroscopic findings based on one random measurement per patient.Table 2.Agreement between arthroscopic classification and treatment.

Suture-Bridge Fixation of Osteochondrial Fractures and Osteochonritis Dissecans in the Adolescent Knee: Mir Assement of Healing

Background:Preservation of articular cartilage in the setting of adolescent knee injury is paramount for long-term joint health. Achieving osseous union, minimizing implant related injury, and eliminating need for reoperation for osteochondral fracture lesions (OCL) and osteochondritis dissecans (OCD) remain a challenge for orthopedic surgeons.Hypothesis/Purpose:To evaluate MRI appearance of osseous and chondral integration following suture bridge construct. Secondarily, to assess short-term complications and outcomes of suture bridge fixation of OCL and OCD in adolescent knees.Methods:Consecutive patients (n=41) treated within a pediatric sports medicine institution who underwent suture-bridge knee fixation of an OCL or OCD from 10/2019-03/2021 were reviewed. MRI within 6 months of surgery was required. Analysis included demographics, pre-operative MRI lesion characteristics, surgical technique, suture type, Postoperative MRIs for lesion healing (Full Union: 100% cancellous/cancellous-chondral lesion continuity, Stable Union: >50% continuity with some fibrous tissue present, Un-united: < 50% continuity and extensive fibrous signal or fluid below the lesion), complications, rates and timing of return-to-sport (RTS), and short-term patient-reported outcomes (Pedi-IKDC, Pedi-FABS, KOOS Symptoms, PROMIS® ).Results:22 knees (20 patients) included 11 OCL and 10 OCD (Table 1). Lesion characteristics: OCL-mean size=248.2(140-459)mm2, mean major length=17.3(12-27)mm, osteochondral= 10(83%), all chondral= 2(17%); OCD-mean size =374.4(130-780)mm2, mean major length=19.3(10-29)mm, progeny bone present =7(70%). 91%(20/22) were treated via mini-arthrotomy, and 86%(19/22) of constructs were absorbable suture. At MRI follow up (6.7 months, 3.0-21.1), OCLs demonstrated 91.7% Full Union, 8.3% Stable Union, 0% Un-united; OCDs demonstrated 50% Full Union, 50% Stable Union, 0% Un-united. At average of 6.4 months, 19(86%) knees had RTS. Pedi-FABS demonstrated a return to similar level of activity and Pedi-IKDC indicated functional improvement in 80% on average 9.6 months post-operatively (Table 2). There were 2 (9.1%) complications (1. repeat arthroscopy for chondroplasty and marrow stimulation for 20% distal margin instability of patellar OCL secondary to patellar instability, 2. Second surgery for patellar stabilization following trochlear OCD suture-bridge in the setting of trochlear dysplasia and no stabilization at primary procedure) and no re-operations needed for suture-bridge construct.Conclusion:In this series of knee OCLs and OCDs, suture-bridge fixation demonstrates excellent rates of healing based on MRI appearance and good early outcomes with minimal short-term complications. This technique may be used by surgeons to avoid loose body removal and marrow-stimulation, and have significant benefits in comparison to metallic and non-metallic screw/tack constructs in the treatment of these challenging lesions. Longer term follow-up and investigation is warranted.Table 1.Patient Demographics and Lesion LocationTable 2.Patient Reported Outcomes

Validation of a Novel Magnetic Resonance Imaging Classification for Osteochondritis Dissecans of the Knee.

The novel Kocher classification is a 3-group magnetic resonance imaging (MRI) classification system for osteochondritis dissecans (OCD) of the knee that was shown to have comparable reliability to that of the established 5-group Hefti classification. The purpose of this study was to evaluate the validity and clinical utility of this simplified system as an alternative to the Hefti classification. Demographic data and arthroscopic findings were retrospectively collected from medical and surgical records of 144 consecutive knees in children with arthroscopically diagnosed knee OCD. OCD lesions on preoperative MRIs and surgical reports (serving as the reference standard) were assessed by independent raters and assigned both a Kocher and Hefti classification. Agreement between MRI classification and arthroscopic findings for both systems was assessed using weighted kappa (kw) coefficients. Validation, accuracy, sensitivity, and specificity were measured by comparing a dichotomized Kocher classification for MRI and arthroscopy, and by estimating Cohen kappa (kc) coefficients. Agreement between arthroscopic findings and treatment type was measured using the Spearman correlation coefficient. Inter-rater reliability between the 2 MRI raters was substantial for the Kocher classification [ka=0.66; 95% confidence interval (CI)=0.56-0.75] and moderate for the Hefti classification (ka=0.57; 95% CI=0.47-0.67). There was no difference detected in the agreement statistics for Kocher versus Hefti classifications (P=0.89). Binary agreement using dichotomized Kocher classifications was worse than the 3-group category classification. When dichotomized, combining Kocher grades 1 and 2 demonstrated moderate agreement (kc=0.41; 95% CI=0.25-0.58), and combining grades 2 and 3 demonstrated fair agreement (kc=0.34; 95% CI=0.21-0.48). There was a strong correlation between arthroscopy-based finding and treatment category for both the Kocher classification (r=0.85; 95% CI=0.80-0.89) and the Hefti classification (r=0.82; 95% CI=0.75-0.86). The validity and clinical utility of the newer 3-group Kocher classification for knee OCD is comparable to that of the well-established 5-group Hefti classification. Both systems help determine lesion stability and characteristics on MRI, which correlate closely to arthroscopic findings. This simplified classification system, with less uncertainty, provides a foundation for further outcomes research to develop an evidence-based algorithm for effective surgical management of OCD lesions of the knee. Level II-diagnostic study.

Incidence of Subsequent Surgical Intervention at Short-term Follow-up in Previously Healing and Stable Juvenile Osteochondritis Dissecans of the Knee.

Juvenile osteochondritis dissecans (OCD) of the knee is a defect of subchondral bone seen primarily in active children and adolescents. Studies have evaluated the incidence of surgery in knee OCD, but the incidence of subsequent surgery in patients with stable, healing lesions cleared to return to activities is unknown. This study sought to determine the incidence of surgery in participants with knee OCD lesions cleared to return to activities and evaluate predictors of subsequent surgery. A single center, retrospective review was performed of participants aged 7 to 18 with knee OCD. Inclusion criteria were stable lesion, skeletal immaturity, no history of previous knee surgery, release to activity without surgery, and at least 12 months of follow-up. Documentation of subsequent surgery was queried in the electronic health record. Participants with no recorded surgery were contacted through phone. Analysis included bivariate and logistic regression. Twenty-five individuals were included in this study, with 7 undergoing surgery after returning to activity. Medial femoral condyle lesions were less likely to undergo surgery (B=-2.6, P=0.038). Average lesion size for the Surgery and No Surgery groups was 1.76±0.65 and 1.32±0.81 cm2, respectively, though not significantly different (P=0.21). The Surgery group returned to activity sooner (3.7 mo, range 1.1 to 6.4) than the No Surgery group (8.1 mo, range 1.8 to 35.4), though not significantly different (P=0.18). Mean follow-up time for the study was 42.7 (range 12.6 to 77.6) months. No participants contacted by phone progressed to surgery or reported symptoms that limited their activities. While the majority of participants with stable, healing, and asymptomatic knee OCD lesions have favorable outcomes with nonoperative management, some lesions may progress to surgery. Lesions on the medial femoral condyle may be predictive of lower likelihood of progression to surgery. Our study provides insight on the outcomes of nonoperative management of OCD lesions. Level IV-prognostic study.

Descriptive Epidemiology From the Research in Osteochondritis Dissecans of the Knee (ROCK) Prospective Cohort

Background: Osteochondritis dissecans (OCD) occurs most commonly in the knees of young individuals. This condition is known to cause pain and discomfort in the knee and can lead to disability and early knee osteoarthritis. The cause is not well understood, and treatment plans are not well delineated. The Research in Osteochondritis Dissecans of the Knee (ROCK) group established a multicenter, prospective cohort to better understand this disease. Purpose: To provide a baseline report of the ROCK multicenter prospective cohort and present a descriptive analysis of baseline data for patient characteristics, lesion characteristics, and clinical findings of the first 1000 cases enrolled into the prospective cohort. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients were recruited from centers throughout the United States. Baseline data were obtained for patient characteristics, sports participation, patient-reported measures of functional capabilities and limitations, physical examination, diagnostic imaging results, and initial treatment plan. Descriptive statistics were completed for all outcomes of interest. Results: As of November 2020, a total of 27 orthopaedic surgeons from 17 institutions had enrolled 1004 knees with OCD, representing 903 patients (68.9% males; median age, 13.1 years; range, 6.3-25.4 years), into the prospective cohort. Lesions were located on the medial femoral condyle (66.2%), lateral femoral condyle (18.1%), trochlea (9.5%), patella (6.0%), and tibial plateau (0.2%). Most cases involved multisport athletes (68.1%), with the most common primary sport being basketball for males (27.3% of cases) and soccer for females (27.6% of cases). The median Pediatric International Knee Documentation Committee (Pedi-IKCD) score was 59.9 (IQR, 45.6-73.9), and the median Pediatric Functional Activity Brief Scale (Pedi-FABS) score was 21.0 (IQR, 5.0-28.0). Initial treatments were surgical intervention (55.4%) and activity restriction (44.0%). When surgery was performed, surgeons deemed the lesion to be stable at intraoperative assessment in 48.1% of cases. Conclusion: The multicenter ROCK group has been able to enroll the largest knee OCD cohort to date. This information is being used to further understand the pathology of OCD, including its cause, associated comorbidities, and initial presentation and symptoms. The cohort having been established is now being followed longitudinally to better define and elucidate the best treatment algorithms based on these presenting signs and symptoms.