Meniscus Injury : Mnemonics

Epomedicine

2 years ago

Meniscus structure

Mnemonic: CD RS

Circumferential fibers: Deep layer
- Resist hoop stress
- Due to this arrangement, vertical mattress sutures are stronger than horizontal mattress sutures as they capture circumferential fibers
Radial fibers: Superficial layer
- Support circumferential fibers

McMurray test

Mnemonic: The heel of the foot points towards the injured meniscus

Meniscus attachments in knee

Each meniscus has something attached to it:

Medial meniscus: Medial collateral ligament
Lateral meniscus: Popliteal muscle

Tear Patterns

Mnemonic: LaHORe FC

“Meniscus adalah tisu/rawan berbentuk huruf C yang berfungsi mencegah dua tulang bergesel di antara satu sama lain di bahagian lutut. Tisu meniscus yang koyak berpunca kebiasaannya daripada bersukan yang melibatkan pergerakan lutut yang banyak. Warga emas” by Rawatan Alternatif Shah Alam is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/?ref=openverse.

Tear pattern	Description	Potential to repair
Longitudinal	Oriented parallel to edge of meniscus a. Complete tear with inner fragment displaced over into the intercondylar notch – Bucket handle tear (Double PCL sign or Double anterior horn sign in MRI) b. Tear is near the menisco-capsular attachment of meniscus – Peripheral tear	Repairable
Horizontal	Tears in the same horizontal axis as the meniscus tissue	Irreparable
Oblique	Full thickness tears running obliquely from the inner edge of meniscus out into the body of meniscus	Irreparable
Radial	Extend from medial rim toward lateral rim of meniscus – can be complete or incomplete; almost unique to lateral meniscus (Ghost meniscus sign in MRI)	Potentially repairable
Flap	Like oblique tear but have a horizontal cleavage element rather than being purely vertical	Irreparable
Complex	Combination of above-mentioned tears; more common in chronic meniscal lesions	Irreparable

Root tears extrude beyond the margin of tibial plateau. It is common in ACL tear and SONK. It exhibits kinematics similar to post-total menisectomy because it disrupts the circumferential fibers. It is repaired to the bone (trans-tibial).

Management of Meniscus Tear

Mnemonic: 3 R

Resection
- For tears that cannot be repaired and history of 2 failed repairs
- Goal: Minimal resection, Stable contour
Repair (healing capacity better in red-red zone, vertical tear and with early repair)
- Inside-out: Gold-standard
  - Indications: All tears except direct posterior
  - Highest mechanical strength
- Outside-in
  - Indications: Anterior horn (lateral meniscus)
  - Less risk of neurovascular injury
  - Requires arthroscopic knot typing
- All-inside: Bio-absorbable anchors; Increasingly popular
  - Indications: Body and posterior tears
  - No incisions required
  - Lower mechanical strength
Replacement
- For younger patients requiring near-total or total menisectomy
- Meniscus graft size must match native meniscus within 5–10%
- Contraindications: Grade III-IV Osteoarthritis or Inflammatory arthritis

Meniscus Repair Versus Resection

Mnemonic: LAST Qualifiers

L – Location from capsule (rim width)	<2 mm	0
	2-3 mm	1
	4-5 mm	2
A – Age	<20 years	0
	20-40 years	1
	>40 years	2
S – Size	1-2 cm	0
	2-3 cm	1
	>4 cm	2
T – Tissue quality	Excellent	0
	Good	1
	Fair	2
Qualifiers	Unstable	2
	Malalignment	1
	Chondromalacia grade III	1
	Radial tear	2
	ACL reconstruction or fibrin clot	-1

Higher scores are associated with higher failure rates.

Repair is indicated if score ≤ 4.