Musculoskeletal condition M22.4 — ICD-10 M22.4

ICD-10: M22.4 | Category: Other Joint Disorders | Billable: Yes

ICD-10 code M22.4 refers to "Recurrent dislocation of the patella," a common musculoskeletal condition affecting individuals across various age groups, particularly adolescents and young adults. This condition occurs when the patella (kneecap) partially or completely dislocates from its normal position in the trochlear groove of the femur during knee movement, leading to pain, instability, and functional impairment. Understanding the underlying anatomy and biomechanics is crucial for effective diagnosis and treatment.

The patella is a sesamoid bone located within the quadriceps tendon, serving as a fulcrum for knee extension and providing protection to the knee joint. It articulates with the femur at the trochlear groove, allowing for smooth movement during flexion and extension.

The primary stabilizers of the patella include:

• Quadriceps Muscle Group: Provides dynamic stability through muscle contraction.
• Patellar Tendon: Connects the patella to the tibia, facilitating movement.
• Medial and Lateral Retinacula: Fibrous structures that help maintain patellar alignment.
• Ligaments: The medial collateral ligament (MCL) and lateral collateral ligament (LCL) provide additional stabilization.

Biomechanically, proper alignment and tracking of the patella are critical for knee function. Abnormalities in these structures can lead to maltracking, resulting in recurrent dislocations or subluxations.

Patient presents with a 23-year-old male who reports intermittent knee pain and a sensation of the knee cap shifting during physical activities, particularly while running. The patient has a history of patellar instability and has not engaged in any recent physical therapy. Code as M22.4 because the documentation supports a diagnosis of recurrent patellar subluxation, characterized by symptoms consistent with the condition.

To support medical necessity and prevent claim denials for ICD-10 code M22.4, the following key documentation elements must be included:

• Diagnosis Specificity: Clearly state the diagnosis of patellar subluxation, including any relevant history of the condition or previous injuries.

• Subjective and Objective Findings: Document the patient's symptoms, physical examination results, and any diagnostic imaging that supports the diagnosis.

• Treatment Plan: Outline a detailed plan of care including referrals for physical therapy, prescribed exercises, and any other interventions.

• Follow-Up Notes: Include documentation of follow-up appointments and the patient's response to treatment, demonstrating ongoing medical necessity.

Subjective: A 30-year-old female presents to the clinic with complaints of left knee pain for the past three months. She reports that the pain worsens with activities such as climbing stairs and squatting. The patient mentions that she often feels her knee cap is "moving out of place." Objective: Upon examination, the left knee shows mild swelling and tenderness along the medial aspect. Range of motion is limited to 90 degrees flexion with pain noted at extremes. The apprehension test reveals a positive result, indicating patellar instability. Assessment: Left patellar subluxation (ICD-10 Code: M22.4) due to underlying muscular imbalances and possible history of previous knee injuries. Plan:

1. Refer the patient to physical therapy focusing on quadriceps strengthening and patellar stabilization exercises.
2. Educate the patient on activity modifications to avoid exacerbating the condition.
3. Schedule a follow-up appointment in six weeks to assess progress and adjust the treatment plan as necessary.

When considering M22.4, several differential diagnoses should be evaluated:

1. Patellar Tendinopathy (M76.5): Pain localized to the inferior pole of the patella.
2. Iliotibial Band Syndrome (M76.3): Lateral knee pain aggravated by activity.
3. Meniscal Tear (S83.2): Joint locking or catching with effusion.
4. Anterior Cruciate Ligament Injury (S83.51): Instability following pivoting movements.
5. Osteochondritis Dissecans (M93.2): Knee pain with associated cartilage lesions.

When documenting M22.4 in EMR systems, ensure comprehensive details are included:

1. Patient history highlighting previous dislocations or related injuries.
2. Results from physical examinations and imaging studies supporting diagnosis.
3. Treatment plans outlining rehabilitation phases with specific goals.

Billing guidance includes using relevant codes for associated procedures such as physical therapy sessions (e.g., CPT codes 97110 for therapeutic exercises). Accurate coding ensures proper reimbursement while maintaining compliance with payer requirements.