Meniscal Knee Injuries

From WikiMSK

This article is still missing information. Join WikiMSK to help expand it


Non-Operative Management

  • The meniscus can repair = “masterly neglect”
  • Greatest healing potential are those that are short (<1cm), longitudinal, stable, and asymptomatic.
  • Stability – evaluated arthroscopically with probing
  • In high level athletes - high risk of tear progression, become symptomatic and eventually require a partial meniscectomy

Operative Mx

Three broad types of surgery

  1. Preservation: Long recovery but reduce risk of OA
  2. Removal of damaged tissue: Speedy recovery but risk future OA
  3. Replacement of damaged tissue

Meniscus Zones

Three zones in the meniscus, with reducing blood supply the more centrally located the tissue

  1. Red-red zone
  2. Red-white zone
  3. White-white zone

Meniscal Repair

  • Tear selection for repair
    • Ideal = Unstable, vertical-longitudinal tear in periphery
    • Meniscus zones: Only peripheral 10-25% of the meniscus is vascularised
    • However acceptable healing rates can occur in the other zones
    • Also beneficial: tear <12 weeks, younger patients, combined ACL repair
  • Bucket handle = vertical longitudinal peripheral tear. Locked knees should be repaired urgently to prevent long term motion loss
  • Techniques
    • Inside-out (gold standard) or outside-in
    • Newer fixation devices (all inside)
    • All forms of repair require many months of prolonged rehabilitation
  • Postoperative rehab
    • typically includes restrictions in knee flexion RO and weight bearing for 6 weeks.
    • Low impact exercise but no running for 2-3 months
    • Return to competition in 6-8 months

Partial Meniscectomy Classic Criteria

Indication = where masterly neglect or repair have a low chance of success

  • complex tear patterns
  • chronic displaced tears with plastic deformation
  • tears in white-white region (rim width > 8mm)
  • Failed repair
  • Degenerative tears (despite being a disproven treatment)

Good at resolving acute symptoms, recovery in several weeks, but more long term OA

Meniscus Replacement

  • Allografts
  • Synthetic scaffolds
  • Does not allow return to competitive sport

Degenerative Tears

Meniscal surgery is not indicated in the context of degenerative tears. This was evaluated in an RCT by Sihvonen et al [1]

  • 146 patients with degenerative meniscal tears without OA. Included those with locking symptoms.
  • Partial meniscectomy vs sham surgery
  • No difference from 12 months to 5 years follow up. [2]
  • Considered one of the highest quality RCTs that exist in all of the surgical literature, and one of the only placebo controlled trials in the entire orthopaedic surgery literature.

Even experienced orthopaedic surgeons cannot predict who will benefit from surgery for degenerative meniscal tears.[3] If conservative management fails, the default isn’t to do something (surgery) that has been disproven to work (and can even make it worse with OA)

There is increased joint space narrowing after arthroscopic partial meniscectomy compared to patients managed non-surgically.[4]


  1. Sihvonen et al.. Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear. The New England journal of medicine 2013. 369:2515-24. PMID: 24369076. DOI.
  2. Sihvonen et al.. Arthroscopic partial meniscectomy for a degenerative meniscus tear: a 5 year follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trial. British journal of sports medicine 2020. 54:1332-1339. PMID: 32855201. DOI.
  3. van de Graaf et al.. Can even experienced orthopaedic surgeons predict who will benefit from surgery when patients present with degenerative meniscal tears? A survey of 194 orthopaedic surgeons who made 3880 predictions. British journal of sports medicine 2020. 54:354-359. PMID: 31371339. DOI. Full Text.
  4. Santana, Daniel C.; Oak, Sameer R.; Jin, Yuxuan; Rothy, Alex; Lee, Ling-Ling; Katz, Jeffrey N.; Winalski, Carl S.; Duryea, Jeff; Jones, Morgan H. (2022-07). "Increased Joint Space Narrowing After Arthroscopic Partial Meniscectomy: Data From the Osteoarthritis Initiative". The American Journal of Sports Medicine (in English). 50 (8): 2075–2082. doi:10.1177/03635465221096790. ISSN 0363-5465. Check date values in: |date= (help)

Literature Review