Pegg Elise C, Mancuso Francesco, Alinejad Mona, van Duren Bernard H, O'Connor John J, Murray David W, Pandit Hemant G
Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
Orthopaedics and Traumatology Unit, San Donà di Piave General Hospital, Venice, Italy.
Clin Biomech (Bristol). 2016 Jan;31:33-9. doi: 10.1016/j.clinbiomech.2015.10.004. Epub 2015 Oct 22.
There is a greater risk of tibial component loosening when mobile unicompartmental knee replacement is performed in anterior cruciate ligament deficient knees. We previously reported on a cohort of anterior cruciate ligament deficient patients (n=46) who had undergone surgery, but no difference was found in implant survivorship at a mean 5-year follow-up. The purpose of this study was to examine the kinematic behaviour of a subcohort of these patients.
The kinematic behaviour of anterior cruciate deficient knees (n=16) after mobile unicompartmental knee replacement was compared to matched intact knees (n=16). Sagittal plane knee fluoroscopy was taken while patients performed step-up and forward lunge exercises. The patellar tendon angle, knee flexion angle and implant position was calculated for each video frame.
The patellar tendon angle was 5° lower in the deficient group, indicating greater anterior tibial translation compared to the intact group between 30 and 40° of flexion. Large variability, particularly from 40-60° of flexion, was observed in the bearing position of the deficient group, which may represent different coping mechanisms. The deficient group took 38% longer to perform the exercises.
Kinematic differences were found between the deficient and intact knees after mobile unicompartmental knee replacement; but these kinematic changes do not seem to affect the medium-term clinical outcome. Whether these altered knee kinematics will have a clinical impact is as yet undetermined, but more long-term outcome data is required before mobile unicompartmental knee replacement can be recommended for an anterior cruciate ligament deficient patient.
在进行前交叉韧带缺失膝关节的活动单髁膝关节置换术时，胫骨部件松动的风险更大。我们之前报道了一组接受手术的前交叉韧带缺失患者（n = 46），但在平均5年的随访中未发现植入物存活率存在差异。本研究的目的是检查这些患者亚组的运动学行为。
将活动单髁膝关节置换术后前交叉韧带缺失膝关节（n = 16）的运动学行为与匹配的完整膝关节（n = 16）进行比较。在患者进行上台阶和前弓步练习时进行矢状面膝关节荧光透视。计算每个视频帧的髌腱角、膝关节屈曲角度和植入物位置。
缺损组的髌腱角低5°，表明在30至40°屈曲之间，与完整组相比，胫骨向前平移更大。在缺损组的轴承位置观察到较大的变异性，特别是在40 - 60°屈曲时，这可能代表了不同的应对机制。缺损组完成练习的时间长38%。
活动单髁膝关节置换术后，缺损膝关节和完整膝关节之间存在运动学差异；但这些运动学变化似乎不影响中期临床结果。这些改变的膝关节运动学是否会产生临床影响尚未确定，但在推荐将活动单髁膝关节置换术用于前交叉韧带缺失患者之前，需要更多的长期结果数据。
