2015 ISAKOS Biennial Congress ePoster #1601
Lateral Meniscal Graft Transplantation: Effect of Fixation Method on Joint Contact Mechanics During Simulated Gait
Moira McCarthy, MD, New York, NY UNITED STATES
Caroline Brial, MEng, New York, New York UNITED STATES
Tony Chen, PhD, Rochester, NY UNITED STATES
Hongsheng Wang, PhD, New York, New York UNITED STATES
Russell F. Warren, MD, New York, NY UNITED STATES
Suzanne A. Maher, PhD, New York, NY UNITED STATES
Hospital for Special Surgery, New York, New York, USA
FDA Status Not Applicable
Summary: Lateral Meniscal Graft Transplantation: Effect of Fixation Method on Joint Contact Mechanics During Simulated Gait
Abstract:
Introduction
Meniscal allograft transplantation is a treatment option for knees that are meniscal deficient or have irreparable meniscal damage.1 For the lateral compartment, common methods of meniscal transplant fixation include keyhole fixation and bone plug fixation. The objective of this study was to assess knee joint contact mechanics on the lateral plateau as a function of meniscal graft fixation method during simulated gait. Our hypothesis was that lateral meniscal transplantation using keyhole fixation would restore contact mechanics of the knee closer to the intact joint.
Methods
Six human cadaveric knees were subjected to physiological loads to simulate gait on a knee simulator.2 Contact stress across the tibial plateau was measured using a sensor that was placed underneath the menisci, across the lateral plateau.2 Four conditions were tested: (1) intact meniscus, (2) keyhole fixation, (3) bone plug fixation, and (4) meniscectomy. Contact area, peak contact stress, total force, and weighted center of contact stress (WCoCS) on the lateral plateau were calculated at the two points of maximum axial load (14% and 45% of the gait cycle). WCoCS was calculated by weighting sensels based on the magnitude of their contact stress.3 Principle component analysis was performed to determine differences in the WCoCS throughout the stance phase of gait (0% to 60% of the gait cycle). A paired one-way ANOVA with Tukey post-hoc test were used for statistical analysis, with p<0.05 representing significance.
Results
At 14% and 45% of the gait cycle, contact area on the lateral plateau was significantly reduced for meniscectomy when compared to all other conditions. Contact area for bone plug fixation at 14% of the gait cycle was also significantly reduced compared to the intact condition. A significant posterior shift of the WCoCS occurred in the meniscectomy condition, relative to the intact condition. This posterior shift was partially restored with both fixation methods. At 14% and 45% of the gait cycle, both the meniscectomized condition and bone plug fixation resulted in a peak contact stress that was significantly greater than the intact condition.
Conclusion
Lateral meniscal transplantation improved the contact mechanics of the meniscal deficient knee during the gait cycle. The hypothesis that keyhole fixation would restore contact mechanics of the knee closer to the intact condition than bone plug fixation was accepted. Additionally, the keyhole method is frequently recommended by surgeons for use in lateral meniscal transplantation because it offers increased graft stability.4,5,6 For these reasons, the keyhole method should be considered the preferable method of fixation for lateral meniscal graft transplantation.
ACKNOWLEDGEMENTS: This study was supported by NIH R01 AR057343, and grant KL2RR000458 of the Clinical and Translational Science Center at Weill Cornell Medical College. We also thank the Clark Foundation, the Kirby Foundation, and the Russell Warren Chair in Tissue Engineering for supporting this study.
REFERENCES: [1] Greis et al: J Am Acad Orthop Surg. 2002. [2] Gilbert et al: J Biomech. 2013. [3] Wang et al: Am J Sports Med. 2014. [4] Rodeo: Am J Sports Med. 2001. [5] Peters, Wirth: The Knee. 2002. [6] Sekiya, Ellingson: J Am Acad Orthop Surg. 2006.