Meniscal Allografts and Other Meniscal Implants

Section: Surgery
Effective Date: January 01, 2020
Revised Date: November 14, 2019
Last Reviewed: November 14, 2019


Meniscal Cartilage Damage

Meniscal cartilage is an integral structural component of the human knee, functioning to absorb shocks and providing load sharing, joint stability, congruity, proprioception, and lubrication and nutrition of the cartilage surfaces. Total and partial meniscectomy frequently result in degenerative osteoarthritis. The integrity of the menisci is particularly important in knees in which the anterior cruciate ligament has been damaged. In these situations, the menisci act as secondary stabilizers of anteroposterior and varus-valgus translation.

Meniscal allograft transplantation (MAT) is considered a salvage procedure, reserved for individuals with disabling knee pain following meniscectomy who are considered too young to undergo total knee arthroplasty or in individuals who require a total or near total meniscectomy for irreparable tears. As a result, the population intended to receive these transplants is relatively limited.

Issues under study include techniques for processing and storing the grafts, proper sizing of the grafts, and appropriate surgical techniques. The four primary ways of processing and storing allografts are fresh viable, fresh frozen, cryopreserved, and lyophilized. Fresh viable implants, harvested under sterile conditions, are less frequently used because the grafts must be used within a couple of days to maintain viability. Alternatively, the harvested meniscus can be fresh frozen for storage until needed. Cryopreservation freezes the graft in glycerol, which aids in preserving the cell membrane integrity and donor fibrochondrocyte viability. CryoLife is a commercial supplier of such grafts. Donor tissues may also be dehydrated (freeze-dried or lyophilized), permitting storage at room temperature. Several secondary sterilization techniques may be used, with gamma irradiation the most common. The dose of radiation considered effective has been shown to change the mechanical structure of the allograft; therefore, nonirradiated grafts from screened donors are most frequently used.


Meniscal allograft transplantation may be considered medically necessary in individuals who have had aprior meniscectomy and have symptoms related to the affected sidewhen all of the following criteria are met:

  • Adult individuals should be too young to be considered an appropriate candidate for total knee arthroplasty or other reconstructive knee surgery (eg, <55 years)
  • Disabling knee pain with activity that is refractory to conservative treatment
  • Absence or near absence (>50%) of the meniscus, established by imaging or prior surgery
  • Documented minimal to absent diffuse degenerative changes in the surrounding articular cartilage (eg, Outerbridge grade II or less, <50% joint space narrowing)
  • Normal knee biomechanics or alignment and stability achieved concurrently with meniscal transplantat

Meniscal allograft transplantation may be considered medically necessary when performed in combination, either concurrently or sequentially, with treatment of focal articular cartilage lesions using any of the following procedures:

  • autologous chondrocyte implantation; or
  • osteochondral allografting; or
  • osteochondral autografting

Use of other meniscal implants incorporating materials such as collagen are considered investigational.

Procedure Codes

29868 G0428

Diagnosis Codes

M23.000 M23.001 M23.002 M23.003 M23.004 M23.005 M23.006
M23.007 M23.009 M23.011 M23.012 M23.019 M23.021 M23.022
M23.029 M23.031 M23.032 M23.039 M23.041 M23.042 M23.049
M23.051 M23.052 M23.059 M23.061 M23.062 M23.069 M23.200
M23.201 M23.202 M23.203 M23.204 M23.205 M23.206 M23.207
M23.209 M23.211 M23.212 M23.219 M23.221 M23.222 M23.229
M23.231 M23.232 M23.239 M23.241 M23.242 M23.249 M23.251
M23.252 M23.259 M23.261 M23.262 M23.269 M23.300 M23.301
M23.302 M23.303 M23.304 M23.305 M23.306 M23.307 M23.309
M23.311 M23.312 M23.319 M23.321 M23.322 M23.329 M23.341
M23.342 M23.349 M23.351 M23.352 M23.359 M23.361 M23.362
M23.369 M23.40 M23.41 M23.42 M23.50 M23.51 M23.52
M23.601 M23.602 M23.609 M23.611 M23.612 M23.619 M23.621
M23.622 M23.629 M23.631 M23.632 M23.639 M23.641 M23.642
M23.649 M23.671 M23.672 M23.679 M23.8X1 M23.8X2 M23.8X9
M23.90 M23.91 M23.92 S83.200 S83.201 S83.202 S83.203
S83.204 S83.205 S83.206 S83.207 S83.209 S83.211 S83.212
S83.219 S83.221 S83.222 S83.229 S83.231 S83.232 S83.239
S83.241 S83.242 S83.249 S83.251 S83.252 S83.259 S83.261
S83.262 S83.269 S83.271 S83.272 S83.279 S83.281 S83.282
S83.289 S83.30XA S83.30XD S83.30XS S83.31XA S83.31XD S83.31XS
S83.32XA S83.32XD S83.32XS

Professional Statements and Societal Positions Guidelines

Practice Guidelines and Position Statements

International Meniscus Reconstruction Experts Forum

The International Meniscus Reconstruction Experts Forum (2015) published consensus statements on the practice of MAT (see Table 10). The Forum's statements included guidance on indications, graft procurement and preparation, surgical technique, and rehabilitation.

Table. Select Consensus Statements on the Practice of MAT


Indications for MAT:

  • Unicompartmental pain post-meniscectom
  • In combination with anterior cruciate ligament reconstruction when meniscus deficient
  • In combination with articular cartilage repair if meniscus deficient

MAT not recommended for asymptomatic meniscus deficient individual.

Potentially poorer outcomes expected in individuals with moderate to severe OA (Kellgren-Lawrence grade ≥3).

Non-irradiated fresh frozen or fresh viable grafts are recommended.

Mechanical axis alignment should be performed prior to MAT; if mechanical axis deviation present, consider realignment osteotomy.

Based on current evidence, the superiority of 1 surgical technique over another (all-suture vs bone) is not established.

Outcome scores should include:

  • Disease-specific: Western Ontario Meniscal Evaluation Tool
  • Region-specific: Knee injury and Osteoarthritis Outcome Score
  • Activity: Marx Activity Rating Scale
  • Qualityof life/utility: EuroQoL 5 dimensions questionnaire

MAT: meniscal allograft transplantation; OA: osteoarthritis.

National Institute for Health and Care Excellence

The guidance from the National Institute for Health and Care Excellence (2012) stated that the evidence on "partial replacement of the meniscus of the knee using a biodegradable scaffold raises no major safety concerns," but evidence for any advantage of the procedure over standard surgery was limited.

American Academy of Orthopaedic Surgeons

The American Academy of Orthopaedic Surgeons (2009) updated its position in 2014, still recommending MAT for active people younger than 55 years old, with the goal of replacing the meniscus cushion before the articular cartilage is damaged. The website also notes that "synthetic (artificial) meniscal tissue has been tried, but there is conflicting information at this time."