IMPROVEMENTS IN FUNCTION AND ACTIVITY LEVELS AFTER PARTIAL MENISCECTOMY ARE INFLUENCED BY SPECIFIC FACTORS

Abstract

Objectives: Partial meniscectomy is the current standard of care for torn menisci not suitable for repair. Arthroscopic partial meniscectomy is the most commonly performed orthopaedic surgical procedure. The purpose of this study was to determine what specific factors influence longevity of improvements in function and activity levels following arthroscopic partial meniscectomy.

Methods: Six hundred forty (640) knees which had undergone isolated partial meniscectomy were identified from a clinical database. One hundred ninety-three (193) knees had partial lateral meniscectomy, 342 had partial medial meniscectomy, and 105 had partial medial and lateral meniscectomy. Average age was 52 years (range, 15 to 79) with 207 females and 433 males. Patients were excluded if they had concurrent ACL reconstructions or microfracture for chondral defects. Lysholm function and Tegner activity scores were collected for a minimum of 8 years after the index partial meniscectomy.

Results: For all knees, Lysholm scores improved significantly from preoperative (54) to 1 year postoperative (76) (p< 0.001). Lysholm scores did not change from year 1 to year 5. At year 6, average Lysholm score decreased to 69, and by year 8, the score decreased further to 63. When comparing degenerative knees to non-degenerative knees, the non-degenerative group had greater improvement and maintained it longer. Medial meniscus patients maintained their improvement at 6 and 7 years while the lateral meniscus group showed less improvement and decreased at years 6 and 7. Anatomic location of meniscus tear (anterior, middle or posterior thirds) was not associated with changes in improvement of Lysholm or Tegner scores. Tegner activity levels improved significantly from preoperative (3.6) to 1 year postoperative (4.7) (p< 0.001). This improvement was maintained at years 2, 3, and 4. There was no significant difference between preoperative Tegner and year-5 Tegner scores (4.0) (p> 0.05). This same finding was also seen at years 6, 7, and 8. In degenerative knees, there was less improvement, and levels declined at years 6, 7, and 8.

Conclusions: Patients who undergo partial meniscectomy can expect 4 to 5 years of improved function and activity levels. Knee function continues to improve up to 5 years, but it decreases as activity levels decrease. Patients who delay treatment or have degenerative changes experience a decrease in function and activity levels sooner. Meniscectomy provides a short term improvement in function and activity levels, but long term improvement seems unlikely. Our findings confirm that specific factors such as which meniscus (medial or lateral) undergoes meniscectomy, chronicity of the tear, and preexisting degenerative changes might be expected to influence longevity of improvements after partial meniscectomy.