New intraoperative protocol for kinematic evaluation of ACL reconstruction: preliminary results

Abstract

A real improvement in anterior cruciate ligament (ACL) surgery would be achieved if a global kinematic evaluation of graft performance could be made during surgery. A quantitative evaluation of all residual instabilities would be helpful in the evaluation of graft performances. This paper describes a new protocol for an accurate and extensive computer-assisted in vivo evaluation of joint laxities during ACL reconstruction. Fifteen in vivo kinematic evaluations during ACL reconstruction were performed using an optical localizer and custom software. The capability of the protocol was studied by analyzing the accuracy and repeatability of the results, the ergonomics of the setup, time taken, interactions with the surgical steps, and efficacy of the acquisitions. Repeatability of the tests, at maximum force, remained under 1 mm/2 degrees . Repeatability in tibia position and orientation was lower than 1 mm/4 degrees . Secondary laxities during stress tests remained under 2 mm/3 degrees . Added time to surgery was about 11 min. ACL graft increased joint stability up to 52% with respect to the preoperative level. The simplicity and morbidity of the test procedure and system was minimally invasive and allowed a quantitative evaluation of knee laxities at time zero. The repeatability of the tests opens the way for future research on in vivo evaluation of different ACL reconstruction techniques, which may lead to a better understanding of associated lesions and their role to the global knee stability.

Correlation between preoperative and postoperative knee kinematics in total knee arthroplasty using cruciate retaining designs

“…Specifically, all kinematic measurements were taken by a single surgeon using one type of CR implant and surgical technique, and furthermore, inter-rater reliability was not measured. However, several in vivo studies have shown a high inter-rater reliability for knee kinematic measurements using a navigation system [3,9,28]. Thus, we consider that our kinematic data allow valid comparisons of the kinematics of preoperative and postoperative conditions in the same knees.…”

Knee stability before and after total and unicondylar knee replacement: In vivo kinematic evaluation utilizing navigation

“…The surgeon first located the hip joint center by circumducting the femur and used a probe to acquire anatomical landmarks (femoral epicondyles, tibial malleoli, and tibial plateau extremities), which were used to compute femoral and tibial reference systems and obtain relative motion data based on the Grood and Suntay algorithm. [28][29][30] After acquiring the landmarks, knee flexion angle and the relative orientation between femur and tibia were displayed in real-time for use in the kinematic evaluation. Kinematic tests included the following manuevers: varus/valgus (VV) stress at 0 and 308 at maximum load and passive ROM from maximum extension to maximum flexion.…”

Assessment of the pivot shift using inertial sensors

“…They have been integral in increasing our understanding of knee kinematics, improving diagnostic capabilities, and stimulating the development of non-invasive devices for quantifying knee laxity in the clinical setting. Despite their efficacy, navigation systems are often invasive, complex, and expensive [26][27][28][29]. Moreover, they cannot be employed in the clinical setting and are typically reserved for intra-operative analysis.…”