Meniscal allograft transplantation of the knee is a surgical procedure used as a treatment option to restore normal meniscal function for selected individuals by replacing the damaged meniscus with donor cadaver allograft cartilage. 

Medically Necessary:

Meniscal allograft transplantation of the knee is considered medically necessary as a treatment for individuals with significant partial (more than 50%) or complete loss of the meniscus* when all of the criteria listed below are met:

• Skeletally mature up to and including age 55 years; and
• Disabling knee pain refractory to conservative treatment; and
• Ligamentous stability prior to surgery or achieved concurrently with meniscal transplantation; and
• Documented mild to moderate articular damage (Outerbridge grade II or less); and
• Normal alignment without varus or valgus deformities

*Absence of meniscus must be firmly established by previous operative reports, magnetic resonance imaging (MRI), or diagnostic arthroscopy

Not Medically Necessary:

Meniscal allograft transplantation of the knee is considered not medically necessary as a treatment for symptomatic individuals with partial or complete loss of the meniscus when criteria listed above are not met.

Investigational and Not Medically Necessary:

Meniscal allograft transplantation of the knee is considered investigational and not medically necessary as a treatment for asymptomatic individuals with partial or complete loss of the meniscus.

Loss of the meniscus either in part or whole, can have a poor prognosis in the long term, with the possibility of future arthritis thought to be proportional to the amount of tissue that is torn or removed. There is growing consensus that meniscal allograft transplantation may be indicated in a narrowly defined subset of individuals considered too young or active for arthroplasty and who meet specific criteria. Recent peer-reviewed research indicates the procedure is useful for carefully selected individuals with persistent pain, intact articular cartilage, normal alignment, and a stable knee joint, and may offer the possibility of cartilage protection. Studies have demonstrated the effectiveness of this procedure in alleviating pain and swelling and in improving knee function in select individuals.

Van Arkel (2002) described a prospective survival analysis of 63 consecutive meniscal allografts transplanted into 57 individuals between 1989 and 1999. The study group consisted of 40 men and 17 women with ages ranging from 26 to 55 years (mean age of 39 years). The mean interval between a total meniscectomy and transplantation was 16 years and the mean follow-up was 60 months. The medial meniscus was transplanted in 17 individuals, the lateral meniscus in 34, and both menisci in the same knee in six persons. The cumulative allograft survival rates were calculated at 50% for the medial, 76% for the lateral, and 67% for combined allografts.

Verdonk and colleagues (2005, 2006) reported on the clinical outcomes of 100 meniscal allograft transplantations which had been completed on 96 individuals between 1989 and 2001. Thirty nine medial and 61 lateral allografts were transplanted into 70 men and 26 women with ages ranging from 16 to 50 years (mean age of 35 years). A survival analysis was performed with a mean duration of follow up of 7.2 years. At ten years, 70% those receiving transplants showed beneficial effects from the allograft. The authors concluded meniscal allograft can significantly relieve pain and improve function of the knee joint.

Von Lewinski and colleagues (2007) studied long term outcomes of the first free meniscal allograft transplantations in five individuals. Between 1984 and 1986, four men and one woman with ages ranging from 24 to 26 years (mean age of 25 years) underwent simultaneous medial meniscal transplantation, anterior cruciate ligament (ACL) reconstruction and femoral advancement or temporary detachment of the medial collateral ligament (MCL). Clinical outcomes were evaluated at 20 years postoperatively by a variety of techniques including radiographs and magnetic resonance imaging (MRI). The radiological examinations revealed two persons with minimal, two persons with moderate and 1 person with severe degenerative changes. MRIs revealed shrinkage of the transplants and degenerative changes. Study limitations reported by the authors included that this was a case series done on those who first received the procedure, the meniscal allograft was always combined with other procedures, all individuals revealed cartilage damage at the time of surgery, control groups were not used, and evaluation criteria changed over time.

Rue and colleagues (2008) evaluated 30 individuals who underwent 31 combined meniscus transplantations and articular cartilage repairs between 1997 and 2004. The study group consisted of 18 males and 12 females with ages ranging from 13.9-47.9 years (mean age of 39.9). They were prospectively studied and completed standardized outcome surveys prior to surgery and annually after surgery for a minimum of 2 years. Two individuals were lost to follow-up, leaving 29 procedures to review. Significant improvements were observed. Seventy six percent of all study participants reported that they were completely (31%) or mostly (45%) satisfied with their results. Overall, 48% of participants were classified as normal or nearly normal at their most recent follow-up using the International Knee Documentation Committee examination score. Ninety percent of participants reported they would have the surgery again. The authors concluded that results of combined procedures were comparable with published reports of these procedures performed in isolation and long term follow-up is needed.

Several recent systematic reviews (Harris, 2010; Hergan, 2010) compared isolated meniscal allograft transplantations with meniscal allograft transplantation performed with a concomitant procedure (such as those for cartilage defects) and detected no significant difference in outcomes. In addition, Hergan and colleagues (2010) concluded that "meniscal allograft transplantation can result in alleviation of knee pain, improvement in knee function, and good patient satisfaction if performed in the optimal candidate."

Although clinical experience has helped define indications for meniscal allograft transplantation, at this time there is still limited information on the long term results of this procedure as well as other factors that impact outcomes. These include: the challenge in early detection of the onset of joint degeneration in those who are known to be meniscus-deficient; lack of information on the biology of the transplanted meniscus including the process of cell migration into the meniscus during cellular re-population and the effect of an immune response on graft remodeling; and lack of information to guide rehabilitation after meniscal transplantation.

Meniscal allograft transplantation of the knee is indicated, according to those who perform it, for those who have had a previous meniscectomy, persistent pain, intact articular cartilage, normal alignment, and a stable joint. If the joint is unstable because of anterior or posterior cruciate ligament injury, these ligaments are reconstructed at the time of transplantation. The suggested ideal candidates are young, skeletally mature, physically active individuals with stable (or stabilizable) knees, normal alignment, and only mild to moderate articular surface damage (Outerbridge Grade II or less). The American Academy of Orthopedic Surgeons (2009) reports a meniscal transplant may be recommended for those who are younger than 55 years.

Contraindications for meniscal transplantation include systemic metabolic degenerative disease, arthritis of the knees, flattening of the femoral condyles or severe degenerative changes (greater than 50% joint space narrowing, bone on bone, or erosion to subchondral bone) and those who are skeletally immature. Meniscal transplantation is not indicated for individuals who have undergone partial or total meniscectomy and do not have symptoms or problems with their knee. Also, those with flattening of the femoral condyles or severe degenerative changes (greater than 50% joint space narrowing, bone on bone, or erosion to subchondral bone) are poor surgical candidates.

It is evident that meniscal allograft transplantation is a viable option for the treatment of symptomatic individuals provided rigid inclusion criteria are met. Those with appropriate indications should expect to do well postoperatively in terms of predictable reduction in pain and an ability to increase activity levels. Only further study will clarify the long-term results of meniscal allografts as well as their role in preventing the progression of secondary osteoarthritis in the involved compartment.

There are two types of cartilage within the knee. The surface or articular cartilage is teflon-like and facilitates the gliding and sliding of the bone ends upon each other. Articular cartilage is present in all of the joints of the body.  The other type of cartilage in the knee is the meniscus, a c-shaped piece of fibrocartilage that lies between the weight bearing joint surfaces of the femur (thigh bone) and the tibia (shin bone). There are two menisci in the normal knee; the outside one is called the lateral meniscus, the inner one the medial meniscus. The meniscus cartilage acts as a cushion and absorbs force traveling up and down the leg and protects the surface cartilage of the knee. The menisci also cup the joint surfaces of the femur and therefore provide some degree of stabilization to the knee.

Injuries to meniscal cartilage fall into two broad categories: traumatic tears which result from a sudden load being applied to the meniscal tissue, often from a twisting injury or blow to the side of the knee; and degenerative tears due to the natural drying out of the inner center of the meniscus that progress with age. As the meniscus becomes less elastic and compliant, a tear may occur with only minimal trauma. A torn meniscus will usually cause pain on the side of the knee that is localized to the meniscus. Typically, low-level swelling sets in the next day after the injury and is associated with stiffness. Any twisting, squatting or impact activities will pinch the tear and cause pain. Often the pain may improve with rest and anti-inflammatory medication after the initial injury but frequently recurs with any aggressive activity. With the exception of the outermost periphery where it joins to the vascular knee lining and has a blood supply, meniscal tissue does not heal and therefore presents a clinical problem which can over time lead to cartilage damage and osteoarthritis.

For isolated tears that are unresponsive to non-operative care, operative treatment may be indicated when disabling symptoms continue. Surgical treatment involves repairing or removing large unstable tears and is dependent on location, age and geometry of the tear, age of the individual and co-existing injury. In general, the principle is to save the meniscus whenever possible. Repair involves roughing up the injured surfaces of the tear and placing sutures or another fixation device across the tear to keep the edges opposed to facilitate healing. A partial meniscectomy is an operative procedure that involves trimming or removing the unstable torn portion of the cartilage, with the goal of eliminating or minimizing symptoms.

Significant meniscal damage can result in changes to meniscal structure and function and as a result, alteration in the alignment of the knee joint. Altered knee alignment results in re-distribution of the forces placed on the joint during normal activity, such as walking, which further damages the meniscus and articular surfaces of the femur or tibia. Over time this damage progresses leading to destruction of the joint.

After a complete loss of the meniscus from an extensive injury or repeated resections, rapid impairment of knee function most often occurs. Without therapy, osteoarthritis develops in most individuals in 5 to 10 years, faster than would occur as a consequence of aging. The treatment options available after meniscal depletion are limited. To find a therapeutic solution, meniscal allograft transplantation has been performed. Meniscal replacement seeks to: 1) reduce pain following removal of the meniscus; 2) prevent degenerative changes of the cartilage and subchondral bone after meniscus removal; 3) avoid or reduce the risk of osteoarthritis; 4) restore the mechanical properties to the joint after meniscal removal.

Proponents of meniscal allograft transplantation state that it can slow the onset of painful, disabling arthritis, avoid or delay the need for knee replacement at a very early age, and allow individuals to continue working and participating in sports or fitness activities.

Allograft: A transplantation of tissue obtained from a donor of the same species; under most circumstances in knee surgery, the donor is a cadaver.

Articular: Of or relating to the skeletal joints.

Arthroscopy: A procedure using a special instrument (arthroscope) that is inserted into the knee.

Chondral: Of or pertaining to cartilage.

Skeletally mature: With respect to evaluation and treatment of the lower extremities, skeletal maturity implies radiographic closure of the epiphyseal growth plates and cessation of vertical growth.

Meniscal: Pertaining to the meniscus, a crescent-shaped cartilage situated in the knee.

Meniscectomy: Removal of the meniscus.

Osteochondral: Pertaining to bone and the attached articular cartilage.

Valgus: An abnormal position in which part of a limb is twisted outward away from the midline.

Varus: An abnormal position in which part of a limb is twisted inward toward the midline.

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services may be Medically Necessary, when criteria are met: 

When Services are Not Medically Necessary:
For the procedure code listed above when criteria are not met  

When Services are Investigational and Not Medically Necessary:
For the procedure code listed above for asymptomatic individuals, for all other indications, or when the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

Future ICD-10 coding (effective 10/01/2013)
A draft of ICD-10 Coding related to this document, as it might look today, is available for reference and comments at: Appendix 1: Future ICD-10 coding

Peer Reviewed Publications:

1. Cameron ML, Briggs KK, Steadman JR. Reproducibility and reliability of the outerbridge classification for grading chondral lesions of the knee arthroscopically. Am J Sports Med. 2003, 31(1):83-86.
2. Cole B, Carter T, Rodeo S. Allograft meniscal transplantation: background, techniques and results. American Academy of Orthopaedic Surgeons. Instr Course Lect. 2003; 52:383-396.
3. Crook TB, Ardolino A, Williams LA, Barlow IW. Meniscal allograft transplantation: a review of the current literature. Ann R Coll Surg Engl. 2009; 91(5):361-365.
4. Felix NA, Paulos LE. Current status of meniscal transplantation. Knee. 2003; 10(1):13-17.
5. Greis PE, Holmstrom MC, Bardana DD, Burks RT. Meniscal injury: II. Management. J Am Acad Orthop Surg. 2002; 10(3):177-187.
6. Harris JD, Cavo M, Brophy R, et al. Biological Knee Reconstruction: A Systematic Review of Combined Meniscal Allograft Transplantation and Cartilage Repair or Restoration. Arthroscopy. 2010 Oct 26. [Epub ahead of print]
7. Hergan D, Thut D, Sherman O, Day MS. Meniscal Allograft Transplantation. Arthroscopy. 2010 Sep 28. [Epub ahead of print]
8. Johnson DL, Bealle D. Meniscal allograft transplantation. Clin Sports Med. 1999; 18(1):93-108.
9. Lubowitz JH, Verdonk PC, Reid JB 3rd, Verdonk R. Meniscus allograft transplantation: a current concepts review. Knee Surg Sports Traumatol Arthrosc. 2007; 15(5):476-492.
10. Maitra RS, Miller MD, Johnson DL. Meniscal reconstruction Part 1: indications, techniques and graft considerations. Am J Orthop. 1999; 28(4):213-218.
11. Maitra RS, Miller MD, Johnson DL. Meniscal reconstruction. Part II: outcome, potential complications, and future directions. Am J Orthop. 1999; 28(5):280-286.
12. Matava MJ. Meniscal allograft transplantation: a systematic review. Clin Orthop Relat Res. 2007; 455:142-157.
13. Mueller SM, Shortkroff S, Schneider TO, et al. Meniscus cells seeded in type I and type II collagen-GAG matrices in vitro. Biomaterials. 1999; 20(8):701-709.
14. Packer JD, Rodeo SA. Meniscal allograft transplantation. Clin Sports Med. 2009; 28(2):259-83, viii.
15. Peters G, Wirth CJ. The current state of meniscal allograft transplantation and replacement. Knee. 2003; 10(1):19-31.
16. Rankin M, Noyes FR, Barber-Westin SD, et al. Human meniscus allografts' in vivo size and motion characteristics: magnetic resonance imaging assessment under weightbearing conditions. Am J Sports Med. 2006; 34(1):98-107.
17. Rath E, Richmond JC, Yassir W, et al. Meniscal allograft transplantation: two- to eight-year results. Am J Sports Med. 2001; 29(4):410-414.
18. Rodeo SA. Meniscal allografts--where do we stand? Am J Sports Med. 2001; 29(2):246-261.
19. Rodeo SA, Seneviratne A, Suzuki K, et al. Histological analysis of human meniscal allografts. J Bone Joint Surg Am. 2000; 82-A(8):1071-1081.
20. Rodkey WG, Steadman JR, Li ST. A clinical study of collagen meniscus implants to restore the injured meniscus. Clin Orthop. 1999; (367 Suppl):S281-292.
21. Rue JP, Yanke AB, Busam ML, et al. Prospective evaluation of concurrent meniscus transplantation and articular cartilage repair: minimum 2-year follow-up. Am J Sports Med. 2008; 36(9):1770-1778.
22. Ryu RK, Dunbar V WH, Morse GC. Meniscal allograft replacement: a 1 year to 6 year experience. Arthroscopy. 2002; 18(9):989-994.
23. Sekiya JK, Ellingson CI. Meniscal allograft transplantation. J Am Acad Orthop Surg. 2006; 14(3):164-174.
24. Sohn DH, Toth AP. Meniscus transplantation: current concepts. J Knee Surg. 2008; 21(2):163-172.
25. Stollsteimer GT, Shelton WR, Dukes A, et al. Meniscal allograft transplantation: A 1- to-5 year follow-up of 22 patients. Arthroscopy. 2000; 16(4):343-347.
26. Van Arkel ER, de Boer HH. Survival analysis of human meniscal transplantations. J Bone Joint Surg Br. 2002; 84(2):227-231.
27. Van Arkel ER, Goei R, de Ploeg I, de Boer HH. Meniscal allografts: evaluation with magnetic resonance imaging and correlation with arthroscopy. Arthroscopy. 2000; 16(5):517-521.
28. Verdonk PC, Demurie A, Almqvist KF, et al. Transplantation of viable meniscal allograft. Survivorship analysis and clinical outcome of one hundred cases. J Bone Joint Surg Am. 2005; 87(4):715-724.
29. Verdonk PC, Demurie A, Almqvist KF, et al. Transplantation of viable meniscal allograft. Surgical technique. J Bone Joint Surg Am. 2006; 88 Suppl:109-118.
30. Verdonk R, Almqvist KF, Huysse W, Verdonk PC. Meniscal allografts: indications and outcomes. Sports Med Arthrosc. 2007; 15(3):121-125
31. Verdonk R. Meniscal transplantation. Acta Orthop Belg. 2002; 68(2):118-127.
32. von Lewinski G, Milachowski KA, Weismeier K, et al. Twenty-year results of combined meniscal allograft transplantation, anterior cruciate ligament reconstruction and advancement of the medial collateral ligament.Knee Surg Sports Traumatol Arthrosc. 2007; 15(9):1072-1082.
33. Wirth CJ, Peters G, Milachowski KA, et al. Long-term results of meniscal allograft transplantation. Am J Sports Med. 2002; 30(2):174-181.
34. Yoldas EA, Sekiya JK, Irrgang JJ, et al. Arthroscopically assisted meniscal allograft transplantation with and without combined anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2003; 11(3):173-182.

Government Agency, Medical Society, and Other Authoritative Publications:

1. American Academy of Orthopaedic Surgeons. Meniscal transplants. Last updated February 2009. Available at: http://orthoinfo.aaos.org/fact/thr_report.cfm?Thread_ID=414&topcategory=Knee&all=all. Accessed on December 16, 2010.

1. National Institute of Arthritis and Musculoskeletal and Skin Diseases. Questions and answers about knee problems. Available at: http://www.niams.nih.gov/Health_Info/Knee_Problems/default.asp. Accessed on December 16, 2010.

Allograft Transplantation
Meniscal Allograft Transplantation