Treatment Outcomes for Osteochondritis Dissecans of the Knee, Elbow and Ankle (OCD-MULTI): A Cohort Study

Patients in this cohort receive non-surgical management, which may include activity restriction, braces/orthoses, immobilizers/casts, therapeutic ultrasound, analgesics, anti-inflammatory medications, and/or Traditional Chinese Medicine (TCM).

This is not an intervention assigned by the study. It encompasses the spectrum of standard conservative and surgical treatments that participants may receive as part of independent clinical care. The specific treatment each participant receives is documented and used to define the study cohorts for observational comparison.

Patients who undergo any of the following standard surgical procedures as part of their routine clinical care: joint debridement, internal fixation, retroarticular drilling, microfracture, autogenous transplantation, or allograft transplantation.

This is not an intervention assigned by the study. It encompasses the spectrum of standard conservative and surgical treatments that participants may receive as part of independent clinical care. The specific treatment each participant receives is documented and used to define the study cohorts for observational comparison.

In this study, the MOCART score quantitatively assesses cartilage/osteochondral repair on MRI across nine dimensions, including integrity of the repaired tissue, surface appearance, signal intensity and integration with surrounding tissue. The total score ranges from 0 to 100; higher scores indicate better morphological repair, with scores >70 defined as good and >85 as excellent. This primary outcome applies to surgically treated participants across the knee, elbow and ankle.

Stage regression of the OCD lesion on serial MRI in conservatively treated participants, assessed by readers blinded to treatment using the joint-specific validated system: the Hefti staging (stages I-V) for the knee, a five-stage T2-weighted MRI staging (stages I-V) for the elbow capitellum, and the Berndt-Harty classification (grades I, IIA, IIB, III and IV) for the talus. Stage regression (a decrease in stage from baseline) indicates structural healing/stabilization and is summarized as the proportion with regression and the change in stage at 24 months.

It is a one-dimensional scale ranging from 0 to 10, used to assess the activity level of patients in terms of sports and daily work. The higher the score, the higher the activity level of knee joint. High score (8-10 points): Indicates the level of competitive sports, with extremely high requirements for the knee joint. Medium score (4-7 points): Represents recreational sports and physical labor, which is the level of most active people. Low score (0-3 points): Represents daily life and sedentary work, with a lower load on the knee joint.

It can comprehensively assess the knee joint's functionality, consisting of 18 questions, covering three dimensions: symptoms, sports activity function, and daily activity function. The higher the score, the better the knee joint's functionality and the fewer the symptoms. Generally, a score of >90 indicates excellent function, while a score of <70 indicates significant functional impairment. The minimum clinically important difference is approximately 10-12 points.

It can assess specific symptoms and functional impairments of the knee joint, and has particular advantages in reflecting instability and limitations in daily activities. It consists of 8 items, with a total score of 100. The higher the score, the better the function. Function classification (widely accepted standard): Excellent: 95 - 100 points; Good: 84 - 94 points; Average: 65 - 83 points; Poor: < 65 points.

It can quantify the intensity of subjective pain and is the simplest and most direct method for pain assessment. It is usually a horizontal line 10 centimeters long, with "no pain" marked at the left end (0 points) and "the most intense pain" marked at the right end (10 points). The patient marks their own sensation on the line. 0 points: No pain. 1-3 points: Mild pain (not affecting sleep). 4-6 points: Moderate pain (affects sleep but is tolerable). 7-10 points: Severe pain (extremely unbearable, seriously affecting sleep and daily life).

The Mayo Elbow Performance Score (MEPS) is a standardized clinician- and patient-reported composite outcome measure used to assess elbow-specific symptoms and functional impairment. It evaluates four domains: pain (0-45 points), range of motion/flexion-extension arc (0-20 points), joint stability (0-10 points), and ability to perform daily activities (0-25 points; combing hair, feeding, hygiene, donning shirt, donning shoes). The total score ranges from 0 to 100, with higher scores indicating better elbow function and less disability. Function classification: Excellent: 90-100 points; Good: 75-89 points; Fair: 60-74 points; Poor: <60 points.

The Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) is a shortened, validated patient-reported outcome measure assessing upper-extremity symptoms and functional impairment. It consists of 11 items covering difficulty with physical activities, pain, tingling, sleep disturbance, and limitations in work and social activities. Each item is rated on a 5-point Likert scale from 1 (no difficulty/no symptom) to 5 (unable/extreme symptom). At least 10 of 11 items must be completed for scoring. The score is transformed to a 0-100 scale using the formula: [(mean of completed items - 1) × 25]. The total score ranges from 0 to 100, where 0 indicates no disability and 100 indicates the most severe upper-extremity disability. Higher scores represent worse function.

The Foot and Ankle Outcome Score (FAOS) is a patient-reported outcome measure assessing foot- and ankle-related pain, symptoms, daily function, sports/recreation function, and quality of life. It consists of 42 items divided into five subscales: Pain (9 items), Other Symptoms (7 items), Activities of Daily Living (17 items), Sport and Recreation (5 items), and Foot- and Ankle-Related Quality of Life (4 items). Each item is scored on a 5-point Likert scale from 0 (no problem) to 4 (extreme problem). Each subscale is normalized to a 0-100 scale, where 100 indicates no symptoms or functional limitation and 0 indicates the worst possible state. Higher subscale scores indicate better foot and ankle function. A total FAOS score is not routinely derived; subscales are reported separately.

The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale is a clinician- and patient-assessed composite measure evaluating clinical status of the ankle and hindfoot. It includes 9 items in three domains: Pain (1 item, 0-40 points), Function (7 items, 0-50 points; activity limitation/support, walking distance, walking surfaces, gait, sagittal motion, hindfoot motion, stability), and Alignment (1 item, 0-10 points). The total score ranges from 0 to 100, with 100 indicating no pain, full function, and good alignment. Higher scores indicate better clinical outcome. Commonly used classification: Excellent 90-100; Good 75-89; Fair 50-74; Poor <50.

This study will systematically monitor and record all adverse events and serious adverse events that occur from the start of treatment until the last follow-up. Adverse events refer to any adverse medical events that occur in patients after receiving treatment. These include, but are not limited to, common complications related to surgery, failure of cartilage repair, joint stiffness, and activity impairment. Serious adverse events include situations that result in death, endanger life, require hospitalization, cause significant functional impairment, or other important medical events.