Indications and limits of meniscal allografts
Introduction
The meniscus plays an important role in the complex biomechanics of the knee joint. It has function in load bearing, load transmission, shock absorption, joint stability, joint lubrication and joint congruity. Loss of this important anatomical structure results in higher peak stresses on the cartilage and eventually leads to cartilage degeneration.1, 2, 3, 4, 5, 6
The current indication for meniscal allograft transplantation is the young or middle-aged patient who presents with moderate to severe pain due to a previous total meniscectomy. Because of the usually mild degenerative cartilage disease, the relative young age of the patients and their desire to lead an active lifestyle, these patients are not candidates for a unicompartimental or total knee arthroplasty. Joint space narrowing should be limited to grade 2 lesions as measured on plain postero-anterior weight bearing radiographs according to the International Cartilage Repair Society (ICRS) classification system. Nevertheless, some studies1, 2, 7, 8, 9, 10 have shown that meniscal allografts can survive in an osteoarthritic joint (Outerbridge grade 3–4), with significant improvement in pain and function. In case of axial malalignment of the lower limb or instability of the knee joint, a corrective osteotomy or stabilization procedure at the time of transplantation is advised. It is the authors' conviction, that an ACL graft is significantly protected by the meniscus allograft as much as the meniscus is protected by an ACL graft. In case of focal cartilage defects, these lesions can be treated concomitantly.11 Chondrocyte transplantation or osteochondral grafting procedures should be performed after completion of the meniscal transplantation in order to prevent accidental damage to the patch or graft during meniscal allograft insertion.12
In an effort to avert early joint degeneration, some also consider young, athletic patients who have had total meniscectomy, as candidates for meniscal transplantation prior to symptom onset.13 However, the results obtained so far still preclude a return to high-impact sports. As such, we do not recommend prophylactic meniscus allograft transplantation in the meniscectomized but asymptomatic patient.
Contraindication to meniscal allograft transplantation is the presence of advanced chondral degeneration, although some studies suggest that cartilage degeneration is not a significant risk factor for failure.14 In general, greater than grade 3 articular cartilage lesions according to the ICRS classification system should be of limited surface area and localized. Radiographic evidence of significant osteophyte formation or femoral condyle flattening is associated with inferior postoperative results because these structural modifications alter the morphology of the femoral condyle.15 Overall, it is believed that patients over age 50 have excessive cartilage lesions and are suboptimal candidates.
Axial malalignment tends to exert abnormal pressure on the allograft leading to loosening, degeneration, and failure of the graft.15 A corrective osteotomy should be considered in patients with more than two degrees of deviation toward the involved compartment, as compared with the mechanical axis of the contralateral limb. Varus or valgus deformity may be managed with either staged or concomitant high tibial or distal femoral osteotomy.12 However, as in any situation in which procedures are combined, it is unclear which aspect of the procedure is implicated in symptom resolution, such as relief of pain.15
Other contraindications to meniscal transplantation are obesity, skeletal immaturity, instability of the knee joint (which may be addressed in conjunction with transplantation), synovial disease, inflammatory arthritis and previous joint infection.
In order to investigate the indications, limitations and results of meniscal allograft implantation we carried out a comprehensive review of the literature.
Section snippets
Materials and methods
In January 2011, we performed a literature search to identify all published and unpublished clinical studies of meniscal allograft transplantation using the following medical electronic databases: MEDLINE, MEDLINE preprints, EMBASE, CINAHL, Life Science Citations and British National Library of Health including the Cochrane
Central Register of Controlled Trials (CENTRAL). The medical databases were searched using the MeSH (Medical Subject heading) terms: meniscus, meniscal transplant,
Results
A total of 39 studies1, 2, 7, 9, 10, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 58 met the inclusion criteria and formed the basis of this review. Due to the small populations studied and the differences in indications, contraindications, preservation techniques, preoperative Outerbridge grade, fixation techniques, surgical techniques, concomitant procedures, evaluation tools and rehabilitation
Discussion
The comparison of published results is difficult due to the large differences in meniscal preservation techniques, types of surgical fixation, the concomitant procedures used, the clinical scoring systems and the follow-up time. Nonetheless, significant relief of pain and improvement in function have been been achieved in a high percentage of patients. These improvements appear to be long-lasting in 70% of patients. Based on plain radiology and MRI, a subset of patients does not show further
References (59)
- et al.
Transplantation of viable meniscal allograft: survivorship analysis and clinical outcome of one hundred cases
J Bone Joint Surg Am
(2005) - et al.
Meniscus allograft survival in patients with moderate to severe unicompartmental arthritis: a 2- to 7-year follow-up
Arthroscopy
(2006) - et al.
Meniscus replacement using Hoffa's infrapatellar fat bodies, initial clinical results
Unfallchirurgie
(1990) - et al.
The current state of meniscal allograft transplantation and replacement
Knee
(2003) - et al.
Autologous perichondral tissue for meniscal replacement
J Bone Joint Surg Br
(1998) - et al.
Medial meniscus replacement by a tendon autograft. Experiments in sheep
J Bone Joint Surg Br
(1992) - et al.
Meniscal allograft transplantation for unicompartmental arthritis of the knee
Clin Orthop
(1997) - et al.
Irradiated meniscus allografts in the human knee: a two to five year follow-up study
Orthop Trans
(1995) - et al.
Meniscal allograft replacement: a 1-year to 6-year experience
Arthroscopy
(2002) - et al.
Combined autologous chondrocyte implantation and allogenic meniscus transplantation: a biological knee replacement
Knee
(2007)
Meniscal allografts – where do we stand?
Am J Sports Med
Chondral injuries of the knee. A contermporary view of cartilage restoration
Orthop Spec Ed
Meniscal allograft trans-plantation
Clin Sports Med
Allograft meniscal transplantation: background, techniques, and results
Instr Course Lect
Meniscal allograft transplantation – part i: background, results, graft selection and preservation, and surgical considerations
Arthroscopy
Meniscal allografts: evaluation with magnetic resonance imaging and correlation with arthroscopy
Arthroscopy
Current status and imaging of allograft meniscal transplantation
Eur J Radiol
MR imaging of meniscal allografts: correlation with clinical and arthroscopic outcomes
Radiology
Meniscal transplantation: a review of 43 cases with 2- to 7-year follow-up
Sports Med Arthrosc Rev
Meniscal allograft transplantation: a 1- to 5-year follow-up of 22 patients
Arthroscopy
Meniscal transplantation in symptomatic patients less than fifty years old
J Bone Joint Surg Am
Human meniscus allografts' in vivo size and motion characteristics: magnetic resonance imaging assessment under weightbearing conditions
Am J Sports Med
Meniscus allograft transplantation: ten-year results of cryopreserved allografts
Arthroscopy
Meniscal allograft transplantation
Sports Med Arthrosc Rev
Clinical evaluation of arthroscopic-assisted allograft meniscal transplantation
Ann Acad Med Singapore
Prospective evaluation of allograft meniscus transplantation: a minimum 2-year follow-up
Am J Sports Med
Concomitant meniscal allograft transplantation and autologous chondrocyte implantation: minimum 2-year follow-up
Am J Sports Med
Current status of meniscal transplantation
Knee
Meniscus allograft transplantation using posterior peripheral suture technique: a preliminary follow-up study
J Orthop Sci
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2022, Arthroscopy - Journal of Arthroscopic and Related SurgeryAn exploratory study of the histomorphogenesis and zonal vascular changes in the human fetal medial meniscus
2021, Translational Research in AnatomyCitation Excerpt :Thorough knowledge of the morphogenesis and zonal vascular changes of the menisci becomes imperative in the development of newer techniques for meniscal restoration. Some of the methods include meniscal allograft transplantation (MAT) [26], Growth factor-based strategies [27], mesenchymal stem cells (MSCs) augmented repair [28], and meniscal scaffolds [29]. Further, the present study may also support the process of developing a tissue-engineered meniscus [30].
Surgical treatment of complex meniscus tear and disease: State of the art
2021, Journal of ISAKOSCitation Excerpt :Coronal malalignment tends to exert abnormal pressure on the allograft leading to graft failure. Verdonk et al reported that total meniscal replacement with allograft is one of the valuable alternatives with a satisfactory long outcome in total resection of the meniscus, and good healing of the peripheral rim to the joint capsule was observed in second-look arthroscopies.28 A systematic review showed that good early and midterm results of MAT could be achieved in a relatively young patient with only mild chondromalacia (lower than Outerbridge grade 3) at the time of transplantation, and radiological examination showed its chondroprotective effect.27
Meniscus Transplantation
2020, Complications in Orthopaedics: Sports MedicineMeniscal Allograft Transplantation Is an Effective Treatment in Patients Older Than 50 Years but Yields Inferior Results Compared With Younger Patients: A Case-Control Study
2019, Arthroscopy - Journal of Arthroscopic and Related SurgeryCitation Excerpt :Thus, although concomitant cartilage lesions are being considered a contraindication less and less and although early MAT actually has recently been suggested in these cases even without marked pain to prevent further diffuse cartilage loss and to potentially yield a better long-term prognosis,19 the limited healing potential of older patients remains a concern. Actually, age has been poorly investigated among factors influencing the outcome of MAT, probably because of the commonly accepted cutoff of 50 years as an indication for MAT,9 and therefore, the evidence on older patients is limited in the literature. In our study, the analysis was focused, through a matched-pair comparative evaluation, on determining the opportunity to extend the indications for MAT to active adults older than 50 years.
Evaluating meniscus allograft transplant using a cost-effectiveness threshold analysis
2018, KneeCitation Excerpt :Absolute indications for MAT do not exist; Rosso et al. identified relative agreement in the literature regarding indications for MAT, including: symptomatology related to previous total or subtotal meniscectomy, young age, stable or well aligned knee, and lack of Outerbridge grade III or IV changes [10]. It has also been suggested that candidates for MAT should have a body mass index (BMI) of less than 30 [11]. However, recent literature has suggested that these indications may be broadened, as authors have shown good outcome in active, middle-aged patients with moderate or severe pre-existing OA, as well as in patients with BMI over 30 [12,13].
Conflict of Interest None of the authors have any conflicts of interest.