Name of the Condition

• Cystic meniscus, unspecified lateral meniscus, left knee
• Medical Term: Meniscal cyst, left knee

Summary

A cystic meniscus refers to a condition where a fluid-filled sac forms on the meniscus of the knee. This condition often affects the lateral meniscus, which is on the outer side of the knee joint. It can cause swelling and pain in the affected knee.

Causes

Cystic meniscus is often caused by degenerative changes or tears within the meniscus itself. It can also develop from repetitive stress or injury to the knee joint.

Risk Factors

• Active participation in sports, particularly those involving repetitive knee motions (e.g., soccer, basketball)
• Aging, which may contribute to degenerative changes
• Previous knee injuries
• Genetic predisposition to joint problems

Symptoms

• Pain or tenderness in the affected knee
• Swelling or a noticeable lump on the outer side of the knee
• Limited range of motion
• Clicking or locking sensation in the knee

Diagnosis

• Physical examination and patient history
• Imaging tests such as MRI (Magnetic Resonance Imaging) or ultrasound to visualize the meniscal cyst
• Arthroscopy in some cases to confirm the diagnosis

Treatment Options

• Rest and physical therapy to strengthen muscles around the knee and improve flexibility
• Aspiration of the cyst to remove fluid and reduce swelling
• Surgical intervention, such as meniscectomy or meniscal repair if conservative measures fail
• How each treatment helps manage or cure the condition

Prognosis and Follow-Up

• The outcome is generally positive with appropriate treatment, although recurrence of the cyst can happen.
• Regular follow-up appointments are important to monitor recovery and adjust treatments if necessary

Complications

• Persistent knee pain if left untreated
• Reduced knee function or mobility
• Potential for meniscal tear progression

Lifestyle & Prevention

• Engage in regular knee-strengthening exercises
• Use proper techniques when participating in sports to reduce knee strain
• Wearing appropriate footwear and knee pads for protection

When to Seek Professional Help

• Persistent knee pain or swelling
• Difficulty bending or straightening the knee
• If the knee feels unstable or locks during movement

Additional Resources

• American Academy of Orthopaedic Surgeons (AAOS) www.aaos.org
• Arthritis Foundation www.arthritis.org

Tips for Medical Coders

• Ensure specific coding for laterality (left knee) with M23.001
• Double-check documentation for specification of the lateral meniscus and cystic nature to avoid miscoding
• Be aware of updates or changes in ICD coding guidelines that may affect cystic meniscus coding