title: Biomechanical Effects of a Horizontal Medial Meniscal Tear and Subsequent Leaflet Resection.
abstract: BACKGROUND
  Horizontal, degenerative tears of the medial meniscus and subsequent meniscectomy can compromise the biomechanical function of the meniscus in load transmission and weightbearing, leading to the development of radiographic and symptomatic tibiofemoral arthritis.
  
  
  OBJECTIVE
  Resection of both leaflets of a horizontal medial meniscal tear will increase peak contact pressures and decrease contact areas in comparison with resection of only the inferior leaflet.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twelve fresh-frozen human cadaveric knees had tibiofemoral peak contact pressures and contact areas under an 1800-N axial load measured by Tekscan in the control state. A horizontal tear was created in the posterior horn of the medial meniscus, and the knees were retested. The knees were tested a third time after resection of the inferior leaflet (single leaflet) and a final time after resection of the superior leaflet (both leaflets). The Friedman test was used to test for group differences in peak pressure (psi) and contact area (mm(2)) between test conditions (native, tear, inferior leaflet resection, and resection of both leaflets).
  
  
  RESULTS
  For the medial compartment, there was a statistically significant difference in peak pressure (P = .03) but not in contact area (P = .70) between testing conditions. Median peak pressure in the medial compartment was significantly greater for resection of both leaflets compared with the tear (406.5 vs 294.7 psi, respectively; P = .002). Median contact area in the medial compartment was greatest for resection of both leaflets (602.7 mm(2)), but there were no statistically significant differences between test conditions (P = .70). For the lateral compartment, there were no statistically significant differences in peak pressure (P = .99) or contact area (P = .77) between test conditions.
  
  
  CONCLUSIONS
  Resection of a single inferior leaflet after a horizontal medial meniscal tear preserves much of the original biomechanical function of the meniscus. Resection of both leaflets leads to a significant increase in contact pressure dispersed over the same contact area, which results in an undesirable biomechanical environment.
  
  
  CONCLUSIONS
  Arthroscopic inferior leaflet resection is a viable option for providing symptomatic relief of horizontal medial meniscal tears and preserves the ability of the meniscus to absorb axial loading on the knee joint, theoretically decreasing the risk of subsequent osteoarthritis.
authors.affiliation: Department of Orthopaedic Surgery, University at Buffalo, Buffalo, New York, USA mjb9rc@mail.missouri.edu.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Brown
authors.affiliation: School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA.
authors.forename: James P
authors.initials: JP
authors.lastname: Farrell
authors.affiliation: Department of Orthopaedic Surgery, University at Buffalo, Buffalo, New York, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Kluczynski
authors.affiliation: Department of Orthopaedic Surgery, University at Buffalo, Buffalo, New York, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Marzo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena / Q000502:physiology; D002102:Cadaver; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology; D012421:Rupture / Q000601:surgery; D000070600:Tibial Meniscus Injuries
keywords: contact area; contact stress; horizontal tear; knee biomechanics; leaflet resection; medial meniscus; osteoarthritis