|Abstract / Summary|
The epidemiology of meniscal lesions was analyzed in a suburban area of Copenhagen with approximately 620,000 inhabitants. The overall incidence of meniscal lesions per 10,000 inhabitants per year was 9.0 in men and 4.2 in women. The highest incidences were seen in the 3rd, 4th and 5th decade of age. In men onset of symptoms was more often related to trauma than in women (77 vs. 64 percent). Bucket-handle lesion was the most frequent type of meniscal lesion in men (35 percent) whereas most peripheral detachments (41 percent) occurred in women. The sex-associated occurrence of knee trauma did not explain the difference between men and women as to type of meniscal lesions.
To compare the clinical, functional and radiological outcome after partial and total meniscectomy 200 patients participated in a prospective and randomized study. They were peroperatively allocated to one of the two open procedures. The results were compared at one year and at 6.3-9.8 years (median 7.8).
After one year more patients with partial meniscectomy (91 percent) than with total meniscectomy (80 percent) had no complaints. At the late review this difference was not observed, but patients with partial meniscectomy had the highest functional scores. In 5 percent knee joint function had improved and in 35 percent deteriorated, in the latter group with no difference between partial and total meniscectomy.
The incidence of lateral laxity rose from 8 to 47 percent and occurred more frequently after total meniscectomy. During the observation period radiological signs of knee joint degeneration changed from solely joint line narrowing into additional ridge formation and flattening of the femoral condyle, but unrelated to whether partial or total meniscectomy had been performed.
Following partial meniscectomy posterior horn lesions had the poorest functional outcome but difference in scores between lesions types was seen only if more than one third of the meniscal surface had been removed. The amount of meniscal tissue excised was inversely correlated to knee joint function except in bucket handle lesions treated with partial meniscectomy. These lesions had the largest areas of meniscal tissue removed but higher functional scores than posterior horn lesions. Preservation of the peripheral rim of the meniscus following partial meniscectomy was essential for the functional outcome after surgery.
The course of symptoms and sports performance was investigated in 36 patients. They were waiting for an arthroscopy of the knee joint due to symptoms suggesting an isolated meniscal lesion. Six to 24 months after being placed on the waiting list, none of the patients noted worsening of symptoms, four had no change and nine had no symptoms. Twenty-three others had improved but 17 had stopped sports or reduced sports activity while only two of the 27 who did sports before they had knee joint symptoms had resumed their normal activity. By the time of admission, 14 patients refused arthroscopy; eight had decided to give up sports indefinitely. Of the 22 patients who underwent arthroscopy, meniscal pathology was demonstrated in 12 cases. In two of these a healed meniscal lesion was found. It was concluded that symptoms of meniscal tears of knees may improve with time, but frequently the patient remains unfit for physical performance such as that needed for sports.
An experimental model for repair of three months old longitudinal and stable lesions in the central avascular portion of the rabbits meniscus was presented: three months after a longitudinal incision in the avascular portion no healing was observed. At that time repair was performed by a full thickness radial cut from the lesion to the joint capsule. Three months later, 9 of 10 menisci had healed mainly with cartilaginous tissue although the repaired areas both at gross inspection and histologically were different from the normal fibrocartilage. It is suggested that synovitis with hyperplasia of the lining cells - present in all cases at the time of repair - plays an important role in the healing process.
The articular cartilage of the rabbits’ knees was studied at three-month intervals after the lesion. Joint cartilage was affected both macro- and microscopically after three months. Scintigraphy was abnormal in all. Meniscal repair did not reverse the cartilage alterations seen at the time of repair, but benefited knees in which further meniscal damage would otherwise develop. Joint cartilage changes after meniscectomy were more pronounced than after meniscal repair or in untreated lesions.