Goble E M, Kohn D, Verdonk R, Kane S M
Western Orthopedics & Sports Medicine, Logan, Utah, USA.
Scand J Med Sci Sports. 1999 Jun;9(3):146-57. doi: 10.1111/j.1600-0838.1999.tb00445.x.
A number of clinical series have described the effect of meniscus allograft replacement in humans. The general indication has been disabling pain following loss of a meniscus in a skeletally mature individual. Overall, healing of the graft to the capsule occurs in up to 80% of all transplants. Revascularization and cell repopulation is found in all grafts but is highly variable. The risk for graft failure seems to be greater with irradiated grafts and in patients with grade III or IV osteoarthritic changes. In most series, patients experienced a decrease in pain and an increase in activity level postoperatively. In many series, concominant surgery (cruciate ligament reconstruction or osteotomy) had been performed. Meniscus replacement with frozen or cryopreserved allografts seems to give the most promising short-term results in patients with post-meniscectomy pain. Controlled, randomized prospective studies are needed to confirm a long-term benefit and better define transplantation indications. Viable meniscus allografts seem to survive transplantation, as donor cells were found in the graft after 2 years. Clinically, pain was reduced and activity increased following transplantation, but after 4 years some of these gains were lost. There was no correlation between postoperative findings on MRI and clinical outcome. Meniscal replacement with a quadriceps tendon autograft in humans resulted in pain reduction, but at second-look arthroscopy, only 2 of 9 tendon autografts looked like a meniscus. Six were in position but still looked like tendons. Total medial meniscus replacement by quadriceps tendon autrograft is still an experimental procedure. There is no proof at present that meniscal substitutes (meniscus allografts or tendon autografts) in humans can protect the hyaline cartilage of the knee from the degeneration, following loss of a meniscus. There is some evidence in animal experiments that under circumstances not yet exactly known, a meniscus substitute can have a protective effect on articular cartilage. Three factors have been identified that prevent proper meniscal function: poor fixation of the meniscal horns, no contact of the graft with the articulating surfaces under load and incorrect positioning of the horns. Meniscal allograft transplantation sensitizes humoral and cell mediated immune systems. Bone plugs attached to meniscal allograft tissue may increase cell surface antigenicity. Deep freezing and especially freeze drying of meniscal tissue decreases host immunogenicity. Cryopreservation maintains the content of donor HLA encoded antigens and is likely more sensitizing to the host. The clinical importance of immune responses to meniscal allografts is not known, but it has not been shown to result in graft failure or rejection. Prospective studies are needed.
多项临床系列研究描述了半月板同种异体移植在人体中的效果。一般适应证为骨骼成熟个体半月板缺失后导致功能障碍的疼痛。总体而言，高达80%的移植手术中移植物与关节囊实现愈合。所有移植物均发现有血管再生和细胞再填充，但差异很大。辐照移植物以及患有III级或IV级骨关节炎改变的患者中，移植物失败的风险似乎更高。在大多数系列研究中，患者术后疼痛减轻，活动水平提高。在许多系列研究中，同时进行了其他手术（交叉韧带重建或截骨术）。对于半月板切除术后疼痛的患者，用冷冻或深低温保存的同种异体半月板进行置换似乎能带来最有希望的短期效果。需要进行对照、随机前瞻性研究以证实长期益处并更好地明确移植适应证。有活力的半月板同种异体移植物似乎能在移植后存活，因为在2年后的移植物中发现了供体细胞。临床上，移植后疼痛减轻，活动增加，但4年后部分改善效果消失。MRI术后表现与临床结果之间无相关性。在人体中用股四头肌肌腱自体移植进行半月板置换可减轻疼痛，但在二次关节镜检查时，9例肌腱自体移植中只有2例看起来像半月板。6例位置正确，但仍看起来像肌腱。用股四头肌肌腱自体移植完全替代内侧半月板仍是一种实验性手术。目前尚无证据表明人体中的半月板替代物（半月板同种异体移植物或肌腱自体移植物）能在半月板缺失后保护膝关节的透明软骨免于退变。动物实验中有一些证据表明，在尚未完全明确的情况下，半月板替代物可对关节软骨产生保护作用。已确定有三个因素会妨碍半月板正常功能：半月板角固定不佳、移植物在负重下未与关节面接触以及角位置不正确。半月板同种异体移植会激活体液免疫和细胞介导的免疫系统。附着在半月板同种异体组织上的骨栓可能会增加细胞表面抗原性。半月板组织的深度冷冻尤其是冻干可降低宿主免疫原性。深低温保存会保留供体HLA编码抗原的含量，可能对宿主更具致敏性。对半月板同种异体移植物免疫反应的临床重要性尚不清楚，但尚未显示其会导致移植物失败或排斥反应。需要进行前瞻性研究。
