S82.016M Nondisplaced osteochondral fracture of unspecified patella, subsequent encounter for open fracture type I or II with nonunion

Name of the Condition

• Nondisplaced osteochondral fracture of unspecified patella, subsequent encounter for open fracture type I or II with nonunion

Summary

This condition involves a fracture of the patella (kneecap) where the bone and overlying cartilage are damaged but remain in their original position (nondisplaced). The fracture is classified as open (type I or II), meaning the skin is broken, and it is a subsequent encounter for treatment. The term "nonunion" indicates that the fracture has not healed properly after an expected time. The cartilage involvement distinguishes this from other patellar fractures, and the open nature indicates exposure of the fracture site to the external environment.

Causes

Direct trauma to the knee, such as a fall onto the kneecap, a forceful blow, or a high-impact injury (e.g., motor vehicle accident or sports injury). The open fracture occurs when the force is sufficient to break the skin and underlying bone-cartilage structure, while the fragments remain aligned. Nonunion may result from inadequate initial treatment, poor blood supply, infection, or excessive movement at the fracture site.

Risk Factors

• Participation in activities with a high risk of knee injury, such as contact sports or skiing.
• Osteoporosis or other bone-weakening conditions.
• Previous knee injuries or surgeries.
• Advanced age, which may reduce bone density.
• Poor nutrition or smoking, which can impair bone healing.

Symptoms

• Persistent pain in the knee, often worsening with activity.
• Swelling and bruising around the kneecap.
• Inability to straighten the knee or bear weight.
• Visible wound or break in the skin over the kneecap (may be healed or present).
• A "popping" sensation at the time of injury (if recent).
• Possible instability or grinding sensation in the knee.

Diagnosis

A physical examination to assess knee movement, swelling, and tenderness. Imaging studies, typically X-rays, to confirm the fracture and evaluate bone alignment. In some cases, a CT scan or MRI may be used to assess cartilage damage or nonunion. Documentation of the open fracture type (I or II) and the nonunion status is critical for accurate coding.

Treatment Options

• Immobilization with a brace or cast to stabilize the knee and promote healing.
• Surgical intervention, such as internal fixation or bone grafting, if nonunion persists or the fracture is unstable.
• Antibiotics or wound care for open fractures to prevent infection.
• Physical therapy to restore strength and range of motion once healing allows.

Prognosis and Follow-Up

Prognosis depends on the severity of the injury, treatment adherence, and individual healing capacity. Nonunion may require extended treatment or additional surgery. Regular follow-up with imaging is necessary to monitor healing progress. Most patients can return to normal activities with proper care, though some may experience long-term knee stiffness or pain.

Complications

• Infection, particularly with open fractures.
• Chronic pain or arthritis in the knee.
• Persistent nonunion requiring further intervention.
• Limited range of motion or knee instability.
• Nerve or blood vessel damage in severe cases.

Lifestyle & Prevention

• Avoid high-impact activities until cleared by a healthcare provider.
• Use protective gear during sports or activities with knee injury risk.
• Maintain a healthy diet rich in calcium and vitamin D to support bone health.
• Quit smoking, as it impairs bone healing.
• Follow post-treatment instructions carefully to optimize recovery.

When to Seek Professional Help

Seek immediate medical attention if you experience severe knee pain, inability to bear weight, visible skin break, or signs of infection (e.g., fever, redness, pus). Contact your provider if pain worsens, swelling persists, or you notice new symptoms like numbness or discoloration.

Tips for Medical Coders

Document the fracture type (open I or II), the nonunion status, and the subsequent encounter context clearly. Ensure the patella is specified as "unspecified" and that the injury is not displaced. Verify that the encounter is coded as subsequent (not initial) and that nonunion is explicitly noted to support the code assignment.