Prevalence and Clinical Characteristics of Osteochondritis Dissecans of the Humeral Capitellum Among Adolescent Baseball Players

BACKGROUND

The prevalence and clinical characteristics of osteochondritis dissecans (OCD) of the humeral capitellum among adolescent baseball players are unknown.

PURPOSE

To determine the OCD prevalence in adolescent competitive baseball players and to investigate the clinical characteristics of these patients.

STUDY DESIGN

Cross-sectional and case-control study; Level of evidence, 3.

METHODS

A total of 2433 baseball players (mean age, 14.5 ± 1.5 years) belonging to junior high school and high school baseball clubs were enrolled. Players completed a questionnaire, and the elbow of each player's throwing arm was assessed by ultrasonography. Participants with abnormal results on ultrasonography were further examined through radiographic study. The OCD lesions were classified into stages based on radiographic results, and demographic data were compared between players with and without OCD lesions.

RESULTS

Osteochondritis dissecans of the humeral capitellum was found in 82 (3.4%) elbows by ultrasonography. Players with an OCD lesion began playing baseball at an earlier age (P = .016), had a longer duration of competitive play (P = .0013), and had experienced more present (P = .0025) and past (P < .0001) elbow pain compared with players without a lesion. There were no differences between the 2 groups in the position played (P = .26). Sixty-eight patients underwent further radiographic examination for OCD (radiography, computed tomography, magnetic resonance imaging). Of these players, 10 (14.7%) were classified as having stage I OCD (radiolucent stage); 26 (38.2%), stage II (fragmentation stage); 9 (13.2%), stage III (loose body stage); 9 (13.2%), stage IV (residual stage); and 14 (23.5%), stage V (postoperative stage).

CONCLUSION

The prevalence of OCD of the humeral capitellum, including latent cases, was 3.4% among adolescent baseball players. Players with OCD lesions began playing baseball at earlier ages, had played for longer periods, and had experienced more elbow pain. The player's current baseball position may not be related to the existence of OCD lesions in adolescents.

A biomechanical analysis of articular cartilage of the human elbow and a potential relationship to osteochondritis dissecans

A cadaveric study of the articular surfaces of the radiocapitellar joint was undertaken to identify a biomechanical mechanism of osteochondritis dissecans of the humeral capitellum. The articulating radial head and capitellum of fresh anatomic specimens were dissected and tested for intrinsic mechanical properties. Significant differences exist in the mechanical properties and thickness of cartilage topographically in the capitellum and radial head, and between the two surfaces. The medial portion of the radial head is the softest of all radiocapitellar osteochondral segments tested. Comparing medial to lateral sites of the capitellum, there is a trend of decreased stiffness; lateral segments are softer than medial ones. The central section of the radial head is significantly stiffer than the lateral capitellum. There is no significant difference between the stiffness of the radial head sites and the medial capitellum. The disparity in the mechanical properties of the central radial head and lateral capitellum would increase strain in the lateral capitellum. During high-valgus stress activities such as throwing, this increased strain may be a factor in the initiation and localization of the dissecans lesion observed in osteochondritis dissecans of the elbow.

Radiological investigations of osteochondrosis dissecans in Standardbred Trotters and Swedish Warmblood horses

A total of 106 Standardbred Trotters and 27 Swedish Warmblood horses, with a radiological diagnosis of osteochondrosis dissecans, were studied over a six year period. The majority were young horses. No statistical difference in frequency between the sexes was demonstrated. In both breeds osteochondrosis was most common in the hock joints, the site of predilection being the distal dorsal tip of the intermediate tibial ridge. On radiographs the lesions of the hock joints were graded on a scale from 0 to 5 according to size, number and localisation of defects and visible loose bodies. The sizes of the loose bodies estimated radiologically were fairly closely correlated with those found at surgery or autopsy.

Prevalence of Osteochondrosis in the Limb Joints of South German Coldblood Horses

This study aimed to quantify the factors associated with the prevalence of the radiological signs of osteochondrosis (OC) and osteochondrosis dissecans (OCD) in South German Coldblood (SGC) horses. The prevalence of OC and OCD in fetlock and hock joints was analysed in 167 young coldblood horses with a mean age of 14 months. The presence of at least one osteochondrotic lesion (OC) in fetlock or hock joints was documented for 61.7% of the horses and 26.9% of the horses had osseus fragments. Osteochondrotic findings at the dorsal aspect of the sagittal ridge of the third metacarpal/metatarsal bone were seen in 53.9% of the horses and palmar/plantar osseous fragments in fetlock joints in 16.2% of the horses. Hock joint OC was found in 40.1% of the horses and hock OCD in 0.6%. Osteochondrotic findings in the distal part of the tibia were prevalent in 28.1% and in the lateral trochlea tali in 17.4% of the horses. The sex of the investigated horses significantly influenced the prevalence of OC in fetlock and hock joints, as well as the findings in the distal part of the tibia and lateral trochlea tali. Age at radiological examination was significant for the prevalence of OC in hock joints, palmar/plantar osseous fragments in fetlock joints and osteochondrotic findings in the distal part of the tibia. Female horses showed a 2-fold higher risk for OC in fetlock and hock joints than male horses. The distribution of the affected horses by age classes showed that radiographic signs of OC in fetlock and hock joints significantly increased at an age of about 1 year. We can conclude from our study that fetlock and hock OC is a prevalent radiographic finding in more than 1-year-old female and male SGC horses.

The relationship between homozygosity and the occurrence of specific diseases in Bouvier Belge des Flandres dogs in The Netherlands

Since purebred dog populations represent closed gene pools, a relatively high level of consanguinity between individuals, and hence of inbreeding, is common. This case control study was conducted to establish the possible connection between the actual level of homozygosity due to inbreeding and specific diseases (flea allergy, osteochondrosis, laryngeal paralysis, neoplasm, autoimmune disease, hypoplastic trachea, and food allergy) occurring in the Bouvier Belge des Flandres breed. One hundred and sixty-eight animals referred to the Utrecht University Clinic formed the patient group. Each of the seven diseases was chosen because of the demonstrability of the diagnosis. Each animal was chosen because one of the selected diseases was established in that individual, and because its pedigree was complete. All dogs of the patient group were born between 1 January 1980 and 31 December 1985. A control group (n = 123) was randomly chosen from the total population of registered Bouviers born in the Netherlands in the same period. pedigree data were obtained from the Dutch Kennel Club. The extent of inbreeding was determined for all animals using Wright's inbreeding coefficient. The distribution of inbreeding coefficients in each patient group was compared with the distribution in controls. Inbreeding coefficients in the control group ranged from 0.0 to 0.406. Animals in which osteochondrosis, food allergy, autoimmune disease, neoplasm, or hypoplastic trachea was diagnosed had higher inbreeding coefficients than controls. It was concluded that in the Bouvier Belge des Flandres dog population examined, the level of homozygosity was positively correlated with occurrence of these diseases.

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.

Osteochondritis dissecans of the humeral head

A rare case of osteochondritis dissecans (OCD) occurring in the humeral head is presented. As there are only six available records in the literature concerning OCD in the humeral head, clinical features, treatment, and etiology of OCD involvement of this anatomical part remains unclear. These points are discussed on the basis of the previous cases and ours. Osteochondritis dissecans of the humeral head commonly affects middle-aged and young males rather than females. The prevalent location of involvement is the anterosuperior aspect of the humeral head. We propose that repetitive microtrauma is one of the important causes of OCD in the humeral head. Moreover, we suggest that the most authentic treatment for OCD with a partial detached osteochondral fragment is removal of this fragment and drilling.

[The magnetic resonance tomography of osteochondrosis dissecans of the knee joint after intravenous gadolinium-DTPA administration]

20 patients with osteochondritis dissecans were studied by MRI over a period of 3-34 months in order to observe healing and determine the viability of the loose fragment. After intravenous contrast, there was increased signal intensity at the junction between the fragment and the epiphyseal bed on T2-weighted sequences; this was interpreted as fibrous granulation tissue surrounding the fragment. The fragments themselves also showed increased signal intensity after gadolinium-DTPA. Intravenous gadolinium allows accurate evaluation of the junctional zone between the fragment and the epiphyseal bed by demonstrating fibrous, vascularised granulation tissue. This can be distinguished from synovial fluid, and it also demonstrates viability of the fragment.

The incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knees: a systematic review and meta-analysis

PURPOSE

The current systematic review and meta-analysis aim to pool together the incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knee.

METHODS

The systematic review was conducted according to PRISMA guidelines. A search was conducted using PubMed and Cochrane Library with the keywords being "knee" and "osteochondritis dissecans" or "osteochondral lesion". All original human studies that reported the incidence or risk factors of osteoarthritis following osteochondritis dissecans of the knee were included.

RESULTS

Nine studies with 496 patients were included. The incidence of osteoarthritis following osteochondritis dissecans is 0.39 (95% CI 0.19-0.59). Patients with a body mass index greater than 25 kg/m2 had a significantly increased risk of osteoarthritis. Fragment excision had an increased relative risk of 1.89 (95% CI 1.19-3.01) of osteoarthritis as compared to fragment preservation. Significant heterogeneity was identified when comparing between juvenile and adult osteochondritis dissecans. The size of the lesions moderated the between-study heterogeneity with regards to the incidence of osteoarthritis, with the relative risk of osteoarthritis in lesions bigger than 4 cm2 being 2.29 (95% CI 1.24-4.23). No other risk factors, including gender of the patient, location of osteochondritis dissecans, stability of osteochondritis dissecans, and surgical versus non-surgical management were significant risk factors.

CONCLUSION

Significant risk factors for osteoarthritis were increased body mass index and fragment excision. Probable but inconclusive risk factors were the age of the patients and the size of the osteochondritis dissecans. The gender of the patient, location of osteochondritis dissecans, the stability of osteochondritis dissecans, and surgical versus non-surgical management of osteochondritis dissecans when appropriate were not significant risk factors.

Osteochondritis Dissecans of skeletal elements of the foot in a 19th century rural farming community from The Netherlands

Osteochondritis Dissecans (OD) is a pathological condition of the subchondral bone and surrounding cartilage of synovial joints, associated with strenuous activity and/or trauma. Reports of OD in archaeological skeletal remains are few and the majority demonstrate low OD prevalence (<1%). A predominantly 19th century skeletal sample from Middenbeemster, the Netherlands, was assessed for OD. The sample included adult individuals of both sexes. There were no definitive OD lesions in non-pedal elements, yet 12.9% of individuals suffered from pedal OD. Few archaeological and clinical reports specify the prevalence of pedal OD. According to the few that do, the Middenbeemster pedal OD prevalence is distinctly high. Several factors could have contributed to this. First, the rural Beemster community was centered around cattle farming, requiring extensive outside work and animal maintenance; thus, increasing the chances of acute/repetitive trauma in the foot. Second, the footwear worn during that period in the Netherlands was the wooden clog. It is suggested that the hard and inflexible clog, which is poor at absorbing shock and limits the movement of the foot, could have resulted in repetitive microtrauma. These two factors combined may have caused a high frequency of OD.

Osteochondritis dissecans: a multicenter study of the European Pediatric Orthopedic Society

To assess of the value of conservative and operative treatment of osteochondritis dissecans of the knee, a multicenter study was performed. In 12 European countries, 798 cases of osteochondritis of the knee have been collected from 44 hospitals. Results were based on 452 patients with 509 affected knees with minimum follow-up was 1 year (mean follow-up, 3 years and 11 months) and sufficient data for evaluation: 61% were male patients; 39% female patients; 318 affected knees were found in juvenile patients; 191 affected knees were in adult or premature patients. The localization was the medial femoral condyle on the lateral side in 51% (typical site) of patients. Various other sites were involved. Of the 509 affected knees, 154 were treated conservatively, 355 were treated surgically (many with multiple operations). For evaluation, the initial situation (at the time of the diagnosis) was favorable in 198 patients (no effusion, diameter of the lesion < 20 mm and no gross dissection on imaging) and unfavorable (one of the parameters did not meet these prerequisites) in 311 patients. The results were better in young patients than in adult patients. However, in the adolescent group, 22% of patients had abnormal knee at follow-up. The classical localization has a better prognosis than an unusual one. Patients with a favorable situation at diagnosis have significantly better results after conservative treatment than those who have undergone operation. When there are signs of dissection, the results are better after operative than after conservative treatment.

Is There a Connection Between Attention Deficit Hyperactivity Disorder and Osteochondritis Dissecans?

BACKGROUND

To determine if children with Osteochondritis Dessicans (OCD) lesions of the distal femur are more likely to have a co-morbid diagnosis of Attention Deficit/ Hyperactivity Disorder (ADHD) than age matched controls and to assess the impact of ADHD on OCD outcomes.

METHODS

A retrospective chart review of patients treated at a single tertiary care hospital between 2000-2012 was performed. Charts were reviewed for a diagnosis of OCD of the distal femur in all skeletally immature patients (males < 16 years and females < 14 years). These were then screened for a comorbid diagnosis of ADHD. Age-matched controls with anterior knee pain without OCD were then reviewed to determine if ADHD was more common in the OCD population. Treatment and outcomes of the OCD lesions were then compared in children with and without ADHD.

RESULTS

The prevalence of ADHD was 23% in patients with OCD lesions and was significantly greater than the 11% found in the anterior knee pain age-matched controls (p<0.05). The average grade of lesions at presentation was similar in both groups (2.2 ADHD vs 2.1 no ADHD) however, at final follow-up, the average OCD grade was significantly worse for children with ADHD (1.4 vs 0.7, p<0.004).

CONCLUSION

There is a significantly higher prevalence of ADHD in children with OCD lesions compared with age-matched controls. This study suggests children that with osteochondritis dessicans and ADHD may not have as favorable treatment course as children without the hyperactivity disorder.Level of Evidence: III.

[Osteochondritis dissecans]

Osteochondritis dissecans (OCD) has been known for more than 100 years. Several reasons have been suggested as the major cause for developing OCD: trauma/microtrauma, ischaemic or genetic reasons. OCD is primarily located in the knee. In adolescent patients with knee symptoms, X-ray of the affected knee and often a subsequent MRI scan is indicated. Depending on the findings, an arthroscopy can be performed. Conservative treatment can be quiet regime or bracing. Operative treatment can be transchondral/retrograde drilling for the in situ lesion or fixation of the unstable lesion.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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 OF EVIDENCE

Level IV-prognostic study.

Prevalence of osteochondral fragments, osteochondrosis dissecans and palmar/plantar osteochondral fragments in Hanoverian Warmblood horses

In this study, the prevalences of osteochondral fragments in the distal (DUI) and proximal interphalangeal joints (PIJ) as well as in the fetlock, hock and stifle joints, of palmar/plantar osteochondral fragments in the fetlock joints (POFs) and of osteochondrosis dissecans (OCD) in fetlock, hock and stifle joints were estimated in a large sample of Hanoverian Warmblood horses. For this purpose, radiographic findings of 9478 Hanoverian Warmblood horses collected from 2005 to 2011 were analyzed. Overall 31.9% of the horses showed one or more osteochondral fragments in at least one joint. The fetlocks were predominantly affected with a prevalence of 19.7%, followed by the hocks with 8.2% and the stifles with 2.7%. For OCD, an overall prevalence of 14.3% was determined. In fetlock joints, 5.4% of the horses had OCD, in the hock joints 6.9% and in the stifle joints 2.6%, with bilateral occurrence in 25.8% of the hock, 24.9% of the stifle and 12.6% of the fetlock joints. POFs were observed in 6.8% of the horses. With a prevalence of 6.3%, the hindlimbs were significantly more frequently affected than the forelimbs with 0.6%. Of the horses with POFs, 16.5% were also affected with OCD. The high prevalences for osteochondral fragments determined in this study show their great importance with regard to economics and animal welfare.

Nineteen years of radiographic screening: Impact of sepsis and evolution of osteochondrosis dissecans prevalence in Walloon sport horses born between 2004 and 2022

Osteochondrosis dissecans is a particularly common developmental orthopaedic disorder in equines. Among its causes, the hereditary component is no longer a matter of debate, and, for several decades, the various studbooks for sport horses have been selecting stallions in order to limit the prevalence of this condition in the population. However, to our knowledge, no study has evaluated changes in the prevalence of osteochondrosis dissecans over time through longitudinal monitoring of a population of sport horses. The study presented here is part of a large screening programme for developmental orthopaedic pathologies in Wallonia (Belgium) and assessed the presence of these lesions over a period of 19 years in the Walloon sport horse population according to constant and standardised sampling and diagnostic criteria. The effects of breeding conditions and infection in foals were also assessed by means of questionnaires. The results showed no significant change in the prevalence of osteochondrosis dissecans in a population of 1099 individuals born between 2004 and 2022. Furthermore, individuals who had suffered from sepsis during their growing period were very significantly predisposed (p < 0.001) to the development of osteochondrosis dissecans compared to a control group, with respectively 14/21 (67%) and 103/364 (28%) of individuals affected. This study suggests that the selection programmes applied to the population studied are not sufficiently strong or adapted to reduce the prevalence of osteochondrosis dissecans in the population over a period of 19 years. Moreover, this study confirms that foals with sepsis and concurrent osteochondrosis dissecans lesions should not necessarily be excluded from breeding programmes on this basis.

Osteochondritis Dissecans of the Knee Associated With Mechanical Overload

BACKGROUND

Osteochondritis dissecans (OCD) of the knee is a rare but potentially incapacitating disorder in which subchondral bone detaches, leading to an osteochondral fragment that can become unstable and progress into a loose body. The exact cause is unknown, although several biological and mechanical factors have been described.

PURPOSE

To provide insight into epidemiological data of a large cohort of patients affected by OCD of the knee and to identify potential factors contributing to the cause of this disorder.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 236 patients (259 knees) affected by OCD were included in our Knee Registry (2005-2022) and retrospectively analyzed. Patient characteristics were extracted from the medical records. Location and International Cartilage Regeneration & Joint Preservation Society grade (1-4) of OCD were assessed using magnetic resonance imaging. If available, a full-leg standing radiograph was used to assess alignment. Additionally, a statistical scoring system for instability risk was created.

RESULTS

A total of 263 OCD lesions were identified in 259 knees, 66.2% on the medial femoral condyle (MFC), 26.6% on the lateral femoral condyle (LFC), 3.8% on the trochlea, 2.7% on the patella, and 0.8% on the lateral tibia plateau. Male patients made up 57.6% of the sample, which had a mean age of 21.8 years. A very high percentage of patients (77.1%; n = 182) practiced sports, of whom 67.6% (n = 123) were engaged in high-impact sports. The location of the OCD lesions and the leg alignment (n = 110) were significantly correlated: MFC lesions were associated with more varus than valgus alignment (47.5% vs 11.3%) and patients with LFC lesions had more valgus than varus alignment (46.7% vs 20.0%; P = .002). Based on age, smoking, sports activity, and preceding trauma, a multivariable scoring system (0-11 points) was created. An increased risk of lesion instability was associated with an increased score: 29.0% at 0 points and 97.0% at 11 points.

CONCLUSION

This study provides detailed epidemiological data for 236 patients affected by OCD of the knee. Older age, smoking, inactivity, and preceding trauma were predictive for instability of OCD lesions. There was an association between OCD of the MFC and varus malalignment and between OCD of the LFC and valgus malalignment. This finding, in combination with the high percentage of patients practicing high-impact sports, suggests an important role for mechanical overload in the pathogenesis of OCD.

Overuse injuries in adolescents

The incidence of overuse injuries in young athletes is on the rise and accounts for a significant number of visits to the primary care office. There are distinctive intrinsic and extrinsic factors that place young athletes at risk for overuse injuries. These injuries vary in severity from being a temporary inconvenience to having potential lifelong morbidity. An understanding of the young athlete and their unique injuries is important for enabling early recognition and treatment. Prevention strategies are also discussed.

Patella and Trochlea Osteochondritis Dissecans: Demographics and Treatment Paradigms

OBJECTIVE

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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 OF EVIDENCE

Level III.

Osteochondritis dissecans of the knee

Osteochondritis dissecans is a separation of an articular cartilage subchondral bone segment from the remaining articular surface. This is a different entity from osteonecrosis, with which osteochondritis dissecans is commonly confused. In osteochondritis dissecans, the fragment separates from a vascular normal bony bed, while in osteonecrosis, the fragment typically is more peripheral and separates from an avascular bony bed. Osteochondritis dissecans is more common in adolescents and young adults, with the knee, elbow, and ankle being the most common sites. Injury to an area of fairly tenuous blood supply is the most likely cause. Treatment is typically nonoperative for stable lesions and operative for unstable lesions. Most patients do well with no long-term sequelae, but this depends on a variety of factors including the location and size of the lesion, patient age, and treatment.