Osteochondral Defect (OCD) of the knee


1. Acute Trauma: A sudden injury or trauma to the knee, such as a sports-related injury (e.g., twisting, direct impact), can cause damage to the articular cartilage and underlying bone. This can lead to the development of an osteochondral defect.

2. Repetitive Microtrauma: Activities that involve repetitive stress on the knee joint, such as running, jumping, or certain occupational activities, can gradually wear down the cartilage and bone over time, contributing to the development of OCD.

3. Joint Instability: Conditions that cause instability in the knee joint, such as ligament injuries (e.g., ACL tears) or chronic knee laxity, can alter the normal biomechanics of the knee. This abnormal stress distribution can lead to focal areas of cartilage and bone damage.

4. Poor Joint Alignment: Malalignment of the knee joint, such as genu valgum (knock-knee) or genu varum (bow-leggedness), can increase the risk of developing osteochondral defects due to abnormal loading on specific areas of the joint.

5. Genetic Predisposition: Some individuals may have a genetic predisposition to developing osteochondral defects, where the structure or composition of their cartilage makes it more susceptible to damage and degeneration.

6. Joint Disorders: Certain joint disorders, such as osteoarthritis, inflammatory arthritis (e.g., rheumatoid arthritis), or osteochondritis dissecans (a specific type of osteochondral defect), can lead to the formation of osteochondral defects as part of the disease process.

7. Vascular Insufficiency: In some cases, poor blood supply to the bone and cartilage of the knee joint can contribute to the development of osteochondral defects, as the tissues may not receive adequate nutrients and oxygen for proper repair and maintenance.

8. Idiopathic Causes: In some instances, osteochondral defects may develop without a clear identifiable cause, and these are referred to as idiopathic defects.


- Pain: Pain is the most common symptom of an osteochondral defect in the knee. The pain may be localized to the affected area and can vary in intensity. It is often exacerbated by weight-bearing activities such as walking, running, or climbing stairs.

- Swelling: Swelling around the knee joint may occur, especially after physical activity or prolonged periods of standing. The swelling is typically localized to the area of the osteochondral defect.

- Stiffness: Individuals with an osteochondral defect may experience stiffness in the knee joint, particularly after periods of inactivity or upon waking in the morning. This stiffness can affect mobility and the ability to fully bend or straighten the knee.

- Catching or Locking Sensation: Some people may feel a catching or locking sensation in the knee joint, especially during movement. This can occur if a loose fragment of cartilage or bone within the defect becomes displaced and interferes with normal joint motion.

- Decreased Range of Motion: The presence of an osteochondral defect can limit the knee joint's range of motion, making it difficult to fully extend or flex the knee.

- Instability: In some cases, the knee may feel unstable or give way due to the altered mechanics caused by the osteochondral defect. This instability can impact balance and increase the risk of further injury.

- Weakness: Muscle weakness around the knee joint may develop as a result of pain and limited mobility associated with the osteochondral defect.

- Grinding Sensation: In more advanced cases, individuals may experience a grinding sensation (crepitus) within the knee joint during movement, which can indicate roughened or irregular surfaces within the defect.


Medical History and Physical Examination:
- Your healthcare provider will begin by discussing your symptoms, including the location and nature of your knee pain, any swelling, stiffness, locking, or instability you may be experiencing.
- They will also ask about your medical history, previous injuries to the knee, and any activities that aggravate or alleviate your symptoms.
- During the physical examination, your provider will assess your knee for tenderness, swelling, range of motion, and signs of instability or joint locking.

Imaging Studies:
- X-rays: X-rays are often the initial imaging study performed to evaluate the knee joint. While X-rays do not show cartilage directly, they can help identify bony abnormalities, such as loose bodies or changes in joint alignment, which may suggest the presence of an OCD.
- MRI (Magnetic Resonance Imaging): MRI is the most sensitive imaging modality for diagnosing OCD because it provides detailed images of soft tissues, including cartilage and bone. MRI can accurately depict the size, location, and extent of the osteochondral defect, as well as assess any associated bone edema or changes in the surrounding tissues.
- CT Scan (Computed Tomography): CT scans may be used in some cases to provide additional information about the bony architecture and the relationship of the defect to surrounding structures, especially if surgical planning is being considered.

- In some cases, when the diagnosis remains uncertain or if surgical intervention is being considered, arthroscopy may be performed. Arthroscopy is a minimally invasive surgical procedure where a small camera (arthroscope) is inserted into the knee joint through small incisions. This allows the surgeon to directly visualize the inside of the knee joint, assess the cartilage and other structures, and potentially treat the osteochondral defect.

Clinical Tests:
- Your healthcare provider may perform specific clinical tests to assess the stability and function of the knee joint, such as ligament stability tests or tests for joint laxity.

Differential Diagnosis:
Your healthcare provider will also consider other conditions that may cause similar symptoms, such as meniscal tears, ligament injuries (e.g., ACL tear), or other types of cartilage damage.


Conservative Management:
- Activity Modification: Avoiding high-impact activities that exacerbate symptoms, such as running and jumping.
- Physical Therapy: A physical therapist can design a program to strengthen muscles around the knee, improve range of motion, and enhance joint stability. This can also include modalities such as ultrasound or electrical stimulation to reduce pain and inflammation. - Orthotic Devices: Custom-made orthotics or braces may be used to unload the affected area of the knee and provide support.

- Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): These medications can help reduce pain and inflammation associated with OCD.
- Pain Relievers: Analgesics may be prescribed to manage pain, especially during periods of flare-ups.

- Corticosteroid Injections: Injections of corticosteroids directly into the knee joint can provide temporary relief from pain and inflammation associated with OCD.
- Hyaluronic Acid Injections: Also known as viscosupplementation, these injections can help lubricate the joint and reduce pain.

Biological Treatments:
- Platelet-Rich Plasma (PRP) or Stem Cell Therapy: These treatments involve injecting concentrated platelets or stem cells from the patient’s own body into the knee joint to promote healing of the osteochondral defect.

Surgical Options:
- Arthroscopic Debridement and Microfracture: This minimally invasive procedure involves using a small camera (arthroscope) to remove loose cartilage and stimulate new cartilage growth by making tiny fractures in the underlying bone. It is typically used for smaller OCDs with intact cartilage edges.
- Osteochondral Autograft Transplantation (OATS) or Mosaicplasty: Healthy cartilage and bone plugs are taken from another part of the knee (autograft) and transplanted into the defect area. This procedure is suitable for larger OCDs and can restore the joint surface.
- Osteochondral Allograft Transplantation: In cases where the defect is too large or complex for OATS, donor cartilage and bone tissue (allograft) can be used to replace the damaged area.
- Autologous Chondrocyte Implantation (ACI): In this procedure, a small sample of healthy cartilage cells (chondrocytes) is harvested from the patient, grown in a laboratory, and then implanted into the defect during a second surgical procedure. This technique is suitable for larger OCDs and aims to regenerate new cartilage tissue.
- Joint Replacement: In severe cases where there is extensive damage to the knee joint and other treatments have failed, total or partial knee replacement surgery may be necessary to relieve pain and restore function.