Disease Description (Causes and Symptoms)
- Definition: A discoid meniscus is a congenital variation of the meniscus in which the central portion is filled in, maintaining a round (disc-shaped) form instead of the normal crescent (C-shaped) form. It is more common in the lateral meniscus.
- Cause/Pathogenesis: Although the cause is not clearly known, it is explained as a congenital deformity that occurs when the central portion does not disappear during fetal development. Because of the change in shape, it is thicker and wider than a normal meniscus, resulting in different mechanical stress and increased susceptibility to tears.
- Main symptoms: Often asymptomatic. When symptoms are present, they may include knee pain, swelling, joint noises (clicking or popping), discomfort during exercise, and limited joint movement (locking, catching, or a fixed/blocked sensation). Symptoms are more likely to be triggered in association with tears or degeneration than in a normal meniscus.
- Diagnosis: It is generally not detected on plain X-rays, and MRI is needed for accurate diagnosis and evaluation of its shape and damage.
Treatment Methods
- Conservative treatment
- Observation (monitoring the course) is recommended when symptoms are mild or absent.
- Pain and inflammation control: Short-term use of nonsteroidal anti-inflammatory drugs (NSAIDs), cold compresses, rest, and activity modification.
- Physical therapy: Strengthening exercises (especially the quadriceps), exercises to restore the joint’s range of motion, weight management, and rehabilitation for functional recovery.
- Surgical treatment
- Indications: Persistent pain, mechanical symptoms (locking or catching), or significant tearing or functional impairment on MRI.
- Arthroscopic treatment (standard): Meniscoplasty (saucerization, partial meniscectomy) reshapes the discoid meniscus into a crescent shape and removes excess tissue, thereby improving mechanical symptoms and preserving the function of the remaining meniscus.
- Repair: If a tear at the edge of the meniscus can be repaired, preservation is attempted through repair (particularly advantageous in areas with good blood supply).
- Total excision (remove) or transplantation: If the tear is extensive or the meniscus is severely degenerated and cannot be preserved, partial or total excision may be followed by consideration of meniscal transplantation depending on symptoms and function.
- Recovery/Rehabilitation: Early joint motion and exercises to restore muscle strength are important after arthroscopy. After repair, limited weight-bearing and exercise restrictions may be necessary for protection.
- Medication: NSAIDs for pain control and, if necessary, short-term analgesics. Standard antibiotics for infection prevention are usually not necessary (standard protocols are followed during surgery).
- Precautions: Excessive excision can increase the long-term risk of knee arthritis (degenerative changes), so preserving as much of the meniscus as possible is considered the top priority.
Outpatient Visit Checkpoints (Including Sample Questions)
Items and preparations:
- A list of currently taken medications (including prescription drugs, OTC drugs, and supplements) and allergy information
- Previous knee imaging (past MRI, X-rays, and test findings), if possible in the original format or on a CD/USB
- Symptom records: when symptoms began, pain intensity (numeric pain scale), symptom patterns (during exercise/at rest), and the frequency and circumstances of mechanical symptoms (locking, catching, and noises)
- Occupational and exercise history: activity level, types of sports participation, and loads placed on the knee by work duties
- History of previous knee injuries or surgery
- Limitations in daily life (going up and down stairs, running, etc.)
Examples of questions helpful for patients to ask during an outpatient visit (items to make notes about):
- When did the symptoms first begin, and what triggered them (including whether there was an injury)?
- Where is the pain, and what is it like (is it constant, or does it worsen with certain movements)?
- Are there mechanical symptoms such as locking, catching, or a feeling of instability?
- What methods help relieve the pain (rest, taking medication, etc.)?
- What activities or exercise have you stopped because of the symptoms?
- What previous knee treatments have you received (physical therapy, injections, surgery, etc.)?
Examples of General Questions to Ask the Doctor
- What are the shape and extent of damage of the discoid meniscus shown on my MRI?
- Is surgery necessary in my situation, or would conservative treatment be sufficient without immediate surgery?
- What treatment (conservative or surgical) do you recommend in my case, and why?
- If I undergo surgery, what surgical method will be used, what is the expected recovery period, and what are the risks of complications?
- When can I expect to return to daily activities and resume exercise after surgery?
- Please explain the side effects or interactions of the medications and methods of pain management.
Examples of Condition-Specific Questions
- Could you explain specifically whether the discoid meniscus on my MRI is ‘complete discoid’ or ‘partial,’ and whether there is a meniscal tear or degeneration?
- To preserve as much of the meniscus as possible, is repair or reshaping (saucerization) possible, and if so, what is the prognosis given my age and activity level?
- For an athlete (or someone with a physically demanding occupation), what are the differences in the time to return to competition and the long-term condition of the joint between undergoing surgery and not undergoing surgery?
(If necessary, showing these questions directly to the doctor during the consultation may make the consultation more efficient.)