Long-Term Results of Meniscal Allograft Transplantation

Abstract

Between May 1984 and December 1986, 23 patients with a history of medial meniscectomy and anterior knee instability were entered into a long-term prospective study of the results of medial meniscal transplantation combined with reconstruction of the anterior cruciate ligament. In 17 cases a lyophilized meniscal allograft was used and in 6 cases a deep-frozen meniscal allograft was used. The patients' clinical outcomes were evaluated 3 and 14 years postoperatively by clinical assessment, Lysholm score, radiographs, magnetic resonance imaging, arthrography, and, in some cases, arthroscopy. Two anterior cruciate ligament reconstruction control groups were used for comparison, one group having previously undergone meniscectomy and one with intact menisci. The follow-up rate was 100% after 14 years. The Lysholm score was 84 +/- 12 points at 3 years postoperatively and 75 +/- 23 points at 14 years. Patients with deep-frozen meniscal transplants generally had better results than patients with lyophilized meniscal transplants. Magnetic resonance imaging evaluation showed good preservation of the deep-frozen meniscal transplants, even after 14 years. The lyophilized meniscal transplants were reduced in size at the second-look arthroscopy and as seen on magnetic resonance imaging examination. When the control groups were compared with the study group, the deep-frozen meniscal allografts were found to be more comparable with an intact meniscus and the lyophilized meniscal allografts were more comparable with the control group knees that had undergone meniscectomy.

Transplantation of Viable Meniscal Allograft

“…Our study showed that transplantation of medial and lateral meniscal allografts significantly reduces pain and improves function of the involved knee joint as measured with the modified HSS score. Our findings substantiate previously published reports on the clinical success of this procedure 4,7,[24][25][26] . Since the rate of clinical success of any surgical procedure is strongly dependent on the duration of follow-up, we performed a Kaplan-Meier survival analysis.…”

“…This rating system has been used to determine knee function in previous reviews of the results of meniscal allografting procedures and of fresh osteochondral allograft procedures in combination with meniscal allografting 15,18,19 . Since meniscal allografting specifically relieves pain and improves function, the pain score and functional score of the modified HSS system were used for the evaluation of the clinical outcome and for the survival analysis [4][5][6][7] . The involved knee joint was evaluated by experienced examiners preoperatively and on a yearly basis postoperatively.…”

“…Therefore, meniscal tissue should be preserved whenever possible. When the meniscus has been completely lost, transplantation of a meniscal allograft has been a therapeutic option with favorable results, in terms of pain reduction and functional improvement, in the medium and long term [4][5][6][7] . These improvements are presumably due to an increase in contact area and thus a decrease in contact peak stress compared with a meniscectomized knee [8][9][10][11] .…”

Meniscal Allograft Transplantation: Where are we Standing?

“…During the first 5 years after MAT, physicians can expect a mean Lysholm score of 80 points (range 60-100), with still values between 60 and 80 points at a follow-up between 10 and 20 years [7]. Also, several studies have reported a significant improvement in postoperative values of the Lysholm score compared to preoperative values [14][15][16][17][18][19]. Many studies found significant improvements after MAT in the International Knee Documentation Committee (IKDC) [11,14,15,17,18,20], with percentages between 70 to 90% of nearly normal or normal values [21][22][23].…”

“…The theoretical advantages of fresh-frozen over cryopreserved allografts are lower immunogenicity, easier process, and lower cost [48]. Lyophilized allografts are not currently recommended because of high percentage of graft shrinkage and greater likelihood of synovitis [19,38,53]. Nowadays, the most commonly used and recommended types of grafts are cryopreserved or fresh-frozen [6,7].…”