Koh Jason Lee, Wirsing Kim, Lautenschlager Eugene, Zhang Li-Oun
Department of Orthopaedic Surgery, Northwestern University Medical School, Chicago, Illinois, USA.
Am J Sports Med. 2004 Mar;32(2):317-20. doi: 10.1177/0363546503261730.
Incongruity of the articular cartilage following osteochondral transplantation affects surface contact pressure.
An 80 N load was applied for 120 seconds to the femoral condyles of 10 swine knees. Contact pressures were measured using Fuji prescale film. Seven conditions were tested: (1) intact articular surface; (2) 4.5-mm diameter defect; (3) grafted with 4.5-mm diameter plug elevated 1 mm above adjacent cartilage; (4) plug elevated 0.5 mm; (5) plug flush; (6) plug sunk 0.5 mm below surface; and (7) sunk 1.0 mm.
Peak contact pressures were significantly (P <.001) elevated by approximately 20% after defect creation and were reduced to normal when plugs were flush. There were large and significant (P<.001) increases in pressure with plugs elevated 1 and 0.5 mm. Contact pressures with plugs sunk 0.5 and 1 mm were significantly (P <.01) higher than intact cartilage but were significantly (P <.01) lower than an empty defect.
Normal contact pressures and patterns can be duplicated with flush articular surface grafts. However, small incongruities, particularly when the plug is elevated, can lead to significantly increased pressure. This reinforces the importance of articular surface congruity in the initial biomechanical state following osteochondral implantation.
骨软骨移植后关节软骨的不协调会影响表面接触压力。
对10只猪膝关节的股骨髁施加80N的负荷，持续120秒。使用富士预敏胶片测量接触压力。测试了七种情况：（1）完整的关节表面；（2）直径4.5mm的缺损；（3）移植直径4.5mm的骨栓，高于相邻软骨1mm；（4）骨栓抬高0.5mm；（5）骨栓齐平；（6）骨栓低于表面0.5mm；（7）下沉1.0mm。
缺损形成后，峰值接触压力显著升高（P<.001），约升高20%，当骨栓齐平时恢复正常。骨栓抬高1mm和0.5mm时，压力有大幅且显著的增加（P<.001）。骨栓下沉0.5mm和1mm时的接触压力显著高于完整软骨（P<.01），但显著低于空洞缺损（P<.01）。
齐平的关节表面移植可重现正常的接触压力和模式。然而，小的不协调，特别是当骨栓抬高时，会导致压力显著增加。这强化了骨软骨植入后初始生物力学状态下关节表面协调性的重要性。
