Meniscectomy in the older patient remains a controversial topic. The aim of our study is to assess the mid-term outcome of arthroscopic partial medial meniscectomy in patients over fifty years of age and attempt to retrospectively identify symptoms and/or findings on examination which can differentiate between non-degenerative medial meniscal tears versus degenerative meniscal changes.
Thirty-two patients over the age of fifty who had undergone arthroscopic medial partial meniscectomy, were reviewed. The average age was 60 (51-74 yrs) and the average follow-up was six years (3-7 yrs). Based upon the intra-operative findings, patients were divided into two groups: (1) non-degenerative meniscal tears (NDM; n = 12) and (2) degenerative meniscal changes (DM; n = 20). Our outcome measurements were with the HSS knee score, a satisfaction score, and weight-bearing X-rays.
In the NDM group, eleven patients were rated excellent or good, and one was rated poor. In the DM group, three patients were rated as excellent or good, eight as fair, and nine as poor. The HSS score was 97 +/- 4.6 for the NDM group and 85 +/- 9.5 for the DM group. The average satisfaction score was 9.2 +/- 0.7 (very satisfied) for the NDM group and 5.8 +/- 2.6 (fairly satisfied) for the DM group. There was no significant difference between the NDM and the DM groups with regards to pre-operative symptoms and signs, except for the McMurray sign, which was found to be positive in 83% of NDM cases versus 25% of DM cases (sensitivity = 83%). Using only these data, the McMurray sign was 67% specific for NDM.
Arthroscopic medial meniscectomy in older patients provides 90% good results six years after a non-degenerative meniscal tear, but only 20% of good results after a degenerative meniscal tear. However, based on this study, neither symptoms nor physical examination are able to differentiate between traumatic meniscal tears and degenerative meniscal changes in older patients. A positive McMurray's sign favors the diagnosis of a traumatic tear. However, a specificity of this test of only 67% as shown in our data questions its utility in clinical decision-making.