Current Concepts in Treating Meniscal Injuries

Introduction

Management of meniscal injuries has evolved significantly over the past few decades. Earlier treatment philosophies favored meniscectomy, but increasing understanding of meniscal biomechanics and long-term joint preservation has shifted modern practice toward meniscal preservation whenever possible.

Current treatment strategies emphasize:

Preservation of meniscal tissue
Restoration of knee biomechanics
Prevention of early osteoarthritis
Evidence-based patient selection

The “Pendulum of Knowledge” in Meniscus Treatment

Medical knowledge often evolves like a pendulum:

Foundational understanding
Introduction of new concepts
Development of dogma
Re-evaluation through evidence
Balanced modern approach

This concept strongly applies to the evolution of meniscus treatment.

Historically:

The meniscus was considered a vestigial structure
Meniscectomy was routinely performed

Modern evidence has demonstrated that:

Meniscal loss significantly increases the risk of osteoarthritis

As a result, treatment philosophy has shifted toward:

“Save the meniscus whenever possible”

Meniscus Anatomy and Structure

Histology

The meniscus is composed predominantly of:

Type I fibrocartilage

It contains:

Relatively low water content

Nutrition

Meniscal nutrition occurs through:

Diffusion from synovial fluid
Peripheral vascular supply

Functional Anatomy

The meniscus is wedge-shaped, which helps:

Improve joint congruency
Enhance load distribution

Major functions include:

Shock absorption
Load transmission
Joint stabilization
Secondary support for ACL and PCL stability

Fiber Orientation

Circumferential Fibers

Also called:

Hoop fibers

These resist:

Compressive forces

Radial Fibers

These maintain:

Structural integrity of the meniscus

Loss of hoop stress results in:

Functional loss of the meniscus

Biomechanical Importance of the Meniscus

The meniscus plays a critical role in knee biomechanics.

Functions include:

Increasing contact area between femur and tibia
Reducing focal stress
Improving force distribution

The meniscus converts:

The relatively flat tibial plateau
Into a more congruent articulation with the femoral condyle

Loss of meniscal tissue causes:

Increased contact pressure
Accelerated cartilage degeneration
Early osteoarthritis

Clinical Examination Pearls

Meniscal Mobility

The lateral meniscus is:

More mobile than the medial meniscus

which explains why:

The medial meniscus is more commonly injured

Mechanical Symptoms

A “click” alone does not confirm meniscal pathology.

A clinically significant meniscal test should reproduce:

Pain
Mechanical symptoms

together.

Evolution of Meniscus Treatment

Historical Approach

Older surgical philosophy considered the meniscus:

Functionally unimportant

leading to:

Routine meniscectomy

Shift in Understanding

Long-term studies demonstrated:

Increased osteoarthritis following meniscectomy

This changed treatment philosophy toward:

Meniscal preservation

Current Standard

Modern principles recommend:

Repair whenever feasible

especially in:

Young patients
Peripheral tears
Associated ACL injuries

Meniscal Repair Outcomes

Better healing outcomes are associated with:

ACL reconstruction
Peripheral vascular tears
Simple vertical longitudinal tears

Healing rates may reach:

Approximately 93–94% when combined with ACL reconstruction

Poor Prognostic Factors

Less favorable healing occurs in:

Complex tears
Degenerative tears
Central avascular zone injuries

Relationship Between ACL and Meniscus

Untreated ACL deficiency significantly increases the risk of meniscal injury.

Important associations include:

Fivefold increase in meniscal tears
Sixfold increase in osteoarthritis risk
Sixteenfold increase in total knee arthroplasty risk

ACL reconstruction helps:

Improve meniscal healing
Prevent further meniscal damage

Expanding Indications for Meniscal Repair

Modern concepts have expanded the definition of:

“Repairable meniscus”

Radial Tears

Previously:

Routinely resected

Current evidence suggests repair may:

Reduce contact stress
Restore near-normal biomechanics

Horizontal Tears

Horizontal cleavage tears can lead to:

Increased contact pressure
Reduced contact area

Repair techniques such as:

Sandwich repair techniques

may help restore function.

Meniscal Root Tears

Meniscal root tears behave biomechanically like:

Total meniscectomy

Root repair may:

Improve clinical outcomes

However:

Incomplete healing
Persistent meniscal extrusion

remain common concerns.

Iatrogenic Meniscal Injury

Meniscal injury may occur during ACL reconstruction.

Potential causes include:

Tunnel malposition
Improper drill angle

This highlights the importance of:

Precise surgical technique

Meniscus Restoration Techniques

Mesenchymal Stem Cells (MSC)

Potential benefits include:

Symptom improvement
Increased meniscal volume on MRI

Limitations of MSC Therapy

Current limitations include:

Poor-quality evidence
Unknown long-term durability
No proven prevention of osteoarthritis

Meniscal Scaffolds

Scaffolds provide:

A framework for tissue regeneration

Reported benefits include:

Increased meniscal volume
Functional improvement

Limitations of Scaffolds

Mixed clinical evidence
Uncertain long-term outcomes

Meniscal Allograft Transplantation (MAT)

Indications

MAT is considered in:

Young symptomatic patients
Meniscal deficiency
Minimal osteoarthritis

Outcomes

Potential benefits include:

Pain reduction
Improved stability
Approximately 77% return to sports

Limitations

Common limitations include:

Meniscal extrusion
Lack of proven osteoarthritis prevention
Limited role as a prophylactic procedure

Degenerative Meniscal Tears

Epidemiology

Degenerative meniscal tears increase with age.

Approximate prevalence:

20% in patients in their 50s
35% in patients in their 60s
50% by age 70

Evidence from Randomized Trials

Studies comparing arthroscopy with:

Sham surgery
Physiotherapy

have shown:

No significant difference in many degenerative tears

Important Clinical Insight

Arthroscopic surgery may have a:

Significant placebo effect

This reinforces the importance of:

Careful patient selection

Current Management Algorithm

Initial Non-Operative Treatment

For degenerative tears without true mechanical locking:

Physiotherapy
NSAIDs
Activity modification
Injections when appropriate

should be the first-line treatment.

Reassessment

Patients are typically reassessed after:

Approximately 3 months

Surgery may be considered if symptoms persist.

Presence of Osteoarthritis

If significant arthritis is present:

Management should focus primarily on osteoarthritis treatment rather than meniscal surgery.

Clarifying Mechanical Symptoms

True Locking

True locking means:

The joint becomes physically stuck

Not True Locking

The following are not considered true locking:

Clicking
Pain inhibition
Transient catching sensations

This distinction is critical for surgical decision-making.

Key Clinical Principles

What Is Well Established

The meniscus is essential for knee health.
Meniscal loss accelerates osteoarthritis.
Preservation is preferable whenever possible.

Current Treatment Philosophy

Repair is preferred over resection.
Combined ACL reconstruction improves healing.
Degenerative tears should initially be managed conservatively.

Current Grey Zones

Areas that continue to evolve include:

Radial tear repair
Horizontal tear management
Root tear outcomes
Biologics and scaffold use
Optimal timing for meniscal transplantation

Final Take-Home Message

Modern meniscus treatment focuses on preservation rather than removal.

Successful management requires:

Understanding meniscal biomechanics
Appropriate patient selection
Evidence-based surgical indications
Long-term joint preservation strategies

Treatment decisions should balance:

Symptoms
Functional demands
Risk of osteoarthritis
Short-term recovery
Long-term outcomes

A balanced, evidence-based approach remains the key principle in contemporary meniscal surgery.

Courtesy: Dr Mark Hutchinson, Visiting Orthopaedic Surgeon – Aspetar

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