What are knee experts currently thinking about meniscus tears?

Current Thinking on Meniscus Tears

Why preserving the meniscus has become one of the most important principles in modern knee surgery

The meniscus was once considered expendable. For many years, the standard treatment for a torn meniscus was straightforward: trim away the damaged tissue and allow the patient to recover quickly.

Modern knee science has changed that approach considerably.

We now understand that the meniscus is one of the most important protective structures within the knee joint. Removing it, even partially, can significantly increase the risk of cartilage wear, instability, overload of the joint surfaces and, ultimately, osteoarthritis.

Preserve the meniscus whenever possible.

What does the meniscus actually do?

Each knee contains two menisci: a medial meniscus on the inner side and a lateral meniscus on the outer side.

These structures are not simply “shock absorbers”. They are highly specialised fibrocartilage structures that:

• Distribute load across the knee.
• Reduce contact pressure on cartilage.
• Improve joint stability.
• Assist lubrication and nutrition of cartilage.
• Help control rotational movement.
• Contribute to proprioception and movement awareness.

When functioning normally, the meniscus converts compressive force into what is known as hoop stress, allowing the knee to tolerate walking, running, twisting and impact activities efficiently.

When the meniscus is damaged or removed, this load distribution mechanism breaks down.

Why has thinking changed?

Historically, many patients underwent arthroscopic partial meniscectomy. This often improved symptoms quickly, particularly mechanical catching or locking.

However, long-term follow-up studies demonstrated an important problem: patients who had meniscal tissue removed developed significantly higher rates of osteoarthritis.

This has altered surgical thinking internationally.

Current evidence increasingly supports:

• Preservation over removal.
• Repair over resection.
• Biological restoration where appropriate.
• Attention to alignment and biomechanics rather than simply removing torn tissue.

Not all meniscus tears are the same

One of the most important developments in modern knee surgery is recognising that “a meniscus tear” is not a single diagnosis.

Different tear patterns behave very differently biologically and biomechanically.

Vertical longitudinal tears

These are often the best tears to repair, particularly in younger active patients. If the tear occurs in the more vascular outer zone of the meniscus, healing potential can be favourable.

Bucket-handle tears are a larger variant where part of the meniscus displaces centrally and may cause locking. Many of these tears are repairable.

Radial tears

Radial tears were once considered irreparable.

We now understand they are biomechanically significant because they disrupt the circumferential fibres responsible for hoop stress transmission.

Modern repair techniques have evolved considerably and many radial tears are now repaired rather than excised.

Horizontal tears

These tears are common in middle age. Historically, the lower leaflet was frequently trimmed away.

Current thinking is more cautious because removal of one leaflet can substantially alter contact pressures within the knee.

Selected horizontal tears can now be repaired, particularly when symptoms are significant and tissue quality remains reasonable.

Meniscus root tears

This is one of the most important areas of modern meniscus surgery.

A meniscus root tear effectively disconnects the meniscus from its tibial attachment. Biomechanically, this can behave similarly to a total meniscectomy.

The consequences can be substantial:

• Rapid cartilage overload.
• Meniscus extrusion.
• Accelerated arthritis.
• Bone stress injury.
• Sudden deterioration in joint function.

Modern treatment increasingly favours root repair in appropriately selected patients.

Ramp lesions

These injuries occur at the back of the medial meniscus and are strongly associated with ACL injuries.

They are sometimes missed on MRI and even during standard arthroscopy. Recognition of ramp lesions has increased significantly because untreated instability in this region may contribute to persistent rotational laxity after ACL reconstruction.

The growing importance of meniscus extrusion

Meniscus extrusion occurs when the meniscus displaces beyond the edge of the tibia.

An extruded meniscus no longer distributes load effectively.

Extrusion is now recognised as being strongly associated with:

• Pain.
• Cartilage degeneration.
• Early osteoarthritis progression.
• Abnormal biomechanics.

Modern techniques such as meniscal centralisation aim to restore the meniscus closer to its normal position and improve load distribution.

Degenerative meniscus tears: surgery is not always the answer

Another important shift in thinking concerns degenerative meniscal tears in middle-aged and older adults.

MRI scans frequently show meniscal abnormalities in people over 40, many of whom have no symptoms at all.

Several studies have shown that in degenerative tears:

• Physiotherapy can produce outcomes similar to arthroscopic trimming.
• Arthroscopy is not always superior to structured rehabilitation.
• Some degenerative tears represent part of an early osteoarthritic process rather than an isolated injury.

This does not mean surgery is never appropriate.

Some patients still benefit substantially from surgery, particularly where there are mechanical symptoms, unstable fragments, locking, failure of rehabilitation, associated root tears or extrusion.

Modern meniscus surgery is becoming increasingly biological

Repair healing depends heavily on blood supply and biological environment.

Emerging techniques include:

• Bone marrow stimulation.
• Fibrin clot augmentation.
• Platelet-rich plasma.
• Stem cell approaches.
• Scaffold implants.

The evidence remains mixed, but there is increasing interest in improving healing biology, particularly in more degenerative or avascular tears.

Alignment matters

Repairing a meniscus in a poorly aligned knee may not succeed.

For example, a patient with significant varus alignment places increased load through the medial compartment.

In selected cases, unloading procedures such as high tibial osteotomy may be combined with meniscal preservation surgery to improve biomechanics and reduce stress on the repaired tissue.

The future of meniscus treatment

Current knee preservation strategies are increasingly focused on:

• Earlier diagnosis.
• Preserving native tissue.
• Restoring biomechanics.
• Preventing osteoarthritis progression.
• Combining biological and mechanical solutions.

The field continues to evolve rapidly.

What was considered irreparable ten years ago may now be reconstructed, repaired or biologically augmented.

Final thoughts

The modern view of the meniscus is fundamentally different from previous generations of orthopaedics.

The meniscus is no longer viewed as expendable tissue. It is a critical structure for long-term knee health.

While not every tear should be repaired, current thinking strongly supports preservation whenever possible, careful assessment of biomechanics and alignment, and a more individualised approach to treatment.

Treatment decisions should not be based simply on the presence of a tear on MRI. The type of tear, symptoms, age, activity level, cartilage health, alignment and overall biomechanics all influence management decisions.

Modern meniscus care is increasingly focused on protecting the future of the knee, not simply addressing current symptoms.