The Effect of Arthroscopic Partial Medial Meniscectomy on Tibiofemoral Stability. (January 2013)

• Record Type: Journal Article
• Authors: Arno, Sally; Hadley, Scott; Campbell, Kirk A.; Bell, Christopher P.; Hall, Michael; Beltran, Luis S.; Recht, Michael P.; Sherman, Orrin H.; Walker, Peter S.
• Is Part Of: American journal of sports medicine. Volume 41:Number 1(2013)
• Page Start: 73
• Page End: 79
• Publication Date: 2013-01
• Subjects: partial meniscectomy -- tibiofemoral stability -- knee laxity -- tibiofemoral displacement; Sports medicine -- Periodicals; Sports injuries -- Periodicals; Orthopedic surgery -- Periodicals; 617.102705
• DOI: 10.1177/0363546512464482
• Languages: English
• ISSNs: 0363-5465

Abstract

Background: There is still little known regarding the effects of meniscus resection size on tibiofemoral stability. Purpose: To determine if partial medial meniscectomy of the posterior horn significantly alters tibiofemoral stability as measured by the anterior-posterior (AP) position and laxity of the medial femoral condyle. Study Design: Controlled laboratory study. Methods: Five cadaveric knees were dissected to the capsule, preserving all ligaments and the quadriceps tendon. Each specimen was first tested on a rig where the AP position and laxity of the medial femoral condyle were measured while a range of forces was applied from full extension to 90° of flexion. Magnetic resonance imaging (MRI) at 3 tesla was then performed for baseline measurements of the meniscus before partial meniscectomy. Arthroscopic partial medial meniscectomy aimed at 30% of the posterior horn was then performed, followed by repeat mechanical testing and MRI. The sequence was then repeated for arthroscopic partial meniscectomy aimed at 60% and 100% of the posterior horn of the medial meniscus. Results: The MRI analysis demonstrated that 22% ± 9% of the original width of the posterior horn was removed at the first resection, 46% ± 11% was removed at the second resection, and the third resection was 100% removal of the posterior horn for all specimens. After 22% resection, no significant difference in AP laxity was observed. A statistically significant increase in AP laxity was observed with 46% resection under a 500-N compressive load compared with the intact meniscus. After full resection, significant increases in AP laxity were observed under a 50-N compressive load compared with the intact and 22% and 46% resections. The 22% resection had similar AP positions as the intact knee, whereas the 46% resection and 100% removal of the posterior horn had statistically further posterior AP positions than the intact knee. Conclusion: Partial medial meniscectomy with ≥46% resection of the original width of the posterior horn significantly altered the AP position of the medial femoral condyle and also increased laxity. Clinical Relevance: These mechanical changes may lead to abnormal cartilage loading and early osteoarthritis.