Knee iSAWE 2

Question

A 35 year old man has medial knee pain and locking after a twisting injury. MRI shows a vertical longitudinal tear of the peripheral medial meniscus.

Knee iSAWE 2, coronal mri of the knee
Coronal MRI of the knee. Image by MBq, Wikimedia Commons, Public domain.
  1. How are meniscal tears classified?
  2. Which tears can be repaired?
  3. Describe your repair techniques and rehabilitation.

Answer

Classification

  • By zone of vascularity, red red (outer third), red white and white white (inner third)
  • By pattern, vertical longitudinal, radial, horizontal cleavage, flap, complex and bucket handle
  • Root tears, which cause loss of hoop stress function similar to total meniscectomy
  • Degenerative tears in older patients

Repairable tears

  • Vertical longitudinal tears in the red red or red white zone
  • Acute tears in young patients
  • Repair at the time of ACL reconstruction heals better
  • Root tears in knees without significant arthritis
  • Degenerative tears in middle aged patients without mechanical locking are treated with physiotherapy, as arthroscopic partial meniscectomy has little benefit

Repair techniques

  • Inside out repair with vertical mattress sutures, the gold standard, protecting the saphenous nerve medially and the peroneal nerve laterally
  • All inside devices for posterior horn tears
  • Outside in repair for anterior horn tears
  • Transtibial pull out repair for root tears
  • Rasp the tear edges and consider marrow venting to improve healing

Rehabilitation

  • Protected weight bearing and limited flexion for 4 to 6 weeks
  • Avoid deep squatting for about 4 months
  • Failure rates of about 15 to 25%

Related pages

Author Contributions

Orthofracs team

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.