What Is Osteochondritis Dissecans?

Overview

Osteochondritis dissecans (OCD) is a disorder that affects joints, particularly the knees, but it can also affect the elbow and ankle. The exact cause isn't always evident, however, it could be related to variables including injury, repetitive stress on the joint, or insufficient blood flow to the affected area. Individuals who are aware of the disease can detect symptoms early on. Early identification can result in quick medical intervention, increasing the likelihood of successful treatment and preventing future joint damage. Knowledge of osteochondritis dissecans is essential for early detection, effective care, and informed decision-making, all of which contribute to improved overall health and well-being.

Introduction

Definition of Osteochondritis Dissecans (OCD)

Osteochondritis dissecans is a joint ailment in which the bone beneath a joint's cartilage dies owing to an insufficient amount of blood flow. This bone and cartilage can then become loose, producing pain and perhaps impeding joint motion.

It can develop symptoms after a joint injury or after several months of activity, particularly high-impact activity like jumping and running, that damages the joint. The ailment most usually affects the knee, although it can also affect the elbows, ankles, and other joints. Children and adolescents are the most commonly affected with osteochondritis dissecans.³

Historically, Osteochondritis dissecans in 1887, was defined as an inflammatory genesis at the border between cartilage and subchondral bone, but further research has contradicted this hypothesis, and the actual pathogenesis remains unknown.

The Research on Osteochondritis Dissecans of the Knee (ROCK) group recently described OCD as a "focal, idiopathic alteration of subchondral bone with risk for instability and disruption of adjacent articular cartilage that may result in premature osteoarthritis”.¹

Importance of understanding and addressing OCD

It is important to understand OCD priorly so that further damage can be prevented and to have knowledge regarding the age groups involved and their respective treatment strategies.

The younger the patient, the greater the likelihood of complete healing and return to pre-injury activities. However, the patient may have to give up sports that involve repetitive actions, such as pitching.

Adults are more likely than children to require surgery for osteochondritis dissecans and are less likely to heal completely. Adults are also more likely than children to develop osteoarthritis in the injured joint.

Osteochondritis dissecans normally resolves on its own when the patient heals. However, the illness may only appear to mend temporarily as symptoms fade. In such circumstances, symptoms may reappear over time.⁴

Causes and risk factors

Factors leading to the development of OCD

The most current literature suggests that the aetiology is complicated and includes:

• "biological factors" (for example, genetic susceptibility, ossification centre deficit, blood supply issues, and endocrine illnesses such as vitamin D inadequacy) and
• "mechanical factors" (for example, repetitive microtrauma, discoid meniscus, anterior horn instability of the meniscus, anterior tibial spine impingement). These elements would work together to determine OCD.¹

Classifications of OCD

Radiological classification

• Stage 1: limited area, subchondral bone compression.
• Stage 2: OCD bone fragment partially detached.
• Stage 3: completely separated OCD bone fragment, still in the underlying crater.
• Stage four: total detachment/loose body¹

MRI with arthroscopic findings classification 

• Type I: articular cartilage thickening and mild signal alterations, but no break
• Type II: articular cartilage breached; fibrous attachment indicated by low-signal rim behind fragment
• Type III: articular cartilage has been breached; strong signal changes behind the fragment indicate synovial fluid between the fragment and the subchondral bone beneath
• Type IV: slack body¹

Arthroscopic classification

• Type I: cartilage weakening and irregularity but no fragment
• Type II: articular cartilage break, with a modest signal rim behind the fragment indicating attachment
• Type III: distinguishable portion that is partially connected yet displaceable (flap lesion)
• Type IV: loose body and articular surface problem¹

Symptoms and diagnosis

Signs and symptoms of osteochondritis dissecans may include the following, depending on the afflicted joint:

• Pain. Physical activity, such as walking up stairs, climbing a hill, or participating in sports, may cause this most prevalent symptom of osteochondritis dissecans.
• Tenderness and swelling. Your skin around the joint may be puffy and tender.
• The popping or locking of a joint. If a loose piece becomes caught between bones during movement, your joint may pop or remain in one place.
• Weakness in the joints. You may have the sensation that your joint is "giving way" or weakening.
• Reduced range of motion. You may be unable to totally straighten the affected limb.³

Stable and unstable lesions

• The symptoms are determined by the location and stage of the lesion. Stable lesions can cause nonspecific symptoms such as catching or locking, but unstable lesions or loose bodies can elicit mechanical symptoms such as catching or locking.
• Joint effusion and restricted range of motion may indicate unstable lesions or loose bodies. Limb alignment and joint stability should be assessed since they have an impact on biomechanical stress on joints.²

Diagnostic procedures and tools

X-RAY 

• The first-line workup for OCD and monitoring therapy response is radiography.
• Radiography can accurately determine lesion location and size, but it is ineffective in determining stability and identifying small lesions.²

MRI

• For diagnosing and characterising OCD, MRI is the gold standard.
• Although MRI has high sensitivity and specificity for identifying OCD, its accuracy in evaluating stability is questionable.²

CT Scan

• CT can be used to assess lesion size and location, loose bodies, and, in particular, osseous healing after fixation.
• It is frequently used to treat capitellar and talar OCD.²

Ultrasonography

• Ultrasound is the most often utilised treatment for capitellar OCD.²

Treatment options

Conservative approaches

Physical activity restriction, physio kinesitherapy and muscle strengthening exercises, load restriction (partial with crutches or total with wheelchair), immobilisation (with brace or plaster), and essential physical therapies.

Among the several conservative treatments recommended, physical activity reduction or suspension (particularly activities involving pivoting, jumping, and repetitive impacts) appears to be of main importance.¹

A three-step procedure for conservative management was developed in a study.

It is as follows:

• Immobilisation and partial weight-bearing with crutches for the first 4-6 weeks. 
• After radiographic control, weight-bearing without immobilisation is permitted in the second phase, and the rehabilitation routine begins with muscle strengthening and full ROM recovery for another 6-12 weeks.
• If radiographic and clinical evidence of recovery are present three to four months following the initial diagnosis, phase 3 can begin with a gradual return to sport and a new control MRI is granted.¹

Surgical interventions

Persistent pain after 6 months and/or the appearance of symptoms of instability necessitate surgical intervention.

After 6 months of conservative treatment, surgical treatment is suggested if pain persists or worsens in the absence of radiographic healing or MRI evidence of lesion instability.

Depending on the type of injury, several surgical procedures are performed: 

•  Drilling is used to treat symptomatic and stable OCD lesions.
•  Fixation of the fragment is used to treat unstable OCD lesions.

When a piece has separated, salvage methods are used.

There are two types of drilling techniques: trans-articular or antegrade drilling and retro-articular or retrograde drilling.¹

Summary

OCD is typically defined as a focal idiopathic modification of subchondral bone with the possibility of instability and disruption of neighbouring articular cartilage, which can lead to early osteoarthritis.

The aetiology is usually thought to be multifaceted, although in-depth understanding is missing, in part due to the difficulties of examining OCD prior to the onset of overt clinical symptoms.²

Conservative treatment, such as limiting athletic activities, is generally adequate to achieve healing in people with open physes. Surgical treatment is determined by the continuation of symptoms after 6 months of conservative treatment and/or the emergence of indicators of lesion instability.¹