Differences in tibial rotation during walking in ACL reconstructed and healthy contralateral knees

Abstract

This study tested the hypotheses that in patients with a successful anterior cruciate ligament (ACL) reconstruction, the internal-external rotation, varus-valgus, and knee flexion position of reconstructed knees would be different from uninjured contralateral knees during walking. Twenty-six subjects with unilateral ACL reconstructions (avg 31 yrs, 1.7 m, 68 kg, 15 female, 24 mo past reconstruction) and no other history of serious lower limb injury walked at a self-selected speed in the gait laboratory, with the uninjured contralateral knee as a matched control. Kinematic measurements of tibiofemoral motion were made using a previously-described point-cluster technique. Repeated-measures ANOVA (α=0.017) was used to compare ACL-reconstructed knees to their contralateral knees at four distinct points during the stance phase of walking. An offset towards external tibial rotation in ACL-reconstructed knees was maintained over all time points (95%CI 2.3±1.3°). Twenty-two out of twenty-six individuals experienced an average external tibial rotation offset throughout stance phase. Varus-valgus rotation and knee flexion were not significantly different between reconstructed and contralateral knees. These findings show that differences in tibial rotation during walking exist in ACL reconstructed knees compared to healthy contralateral knees, providing a potential explanation why these patients are at higher risk of knee osteoarthritis in the long-term.

Can Joint Contact Dynamics Be Restored by Anterior Cruciate Ligament Reconstruction?

“…Abnormal rotational knee kinematics occurs after ACL injury and remains even after conventional SB ACL reconstruction [1,8,13,15,29,30,32,33]. The ability of DB ACL reconstruction to restore normal rotational kinematics during functional activity remains controversial [18,20,24,26].…”

“…Abnormal knee rotation occurs after ACL injury and is not corrected by conventional single-bundle (SB) ACL reconstruction [1,8,13,15,29,30,32,33]. Abnormal knee kinematics (translations, rotations) has been implicated in the initiation and progression of knee osteoarthritis secondary to altered normal joint contact [5].…”

Variations in the three‐dimensional location and orientation of the ACL in healthy subjects relative to patients after transtibial ACL reconstruction

“…[4][5][6] Observations of alterations in tibiofemoral kinematics following ACL reconstruction [7][8][9] have lead some authors to suggest that restoration of normal kinematics may play an important role in preventing premature OA in this population. [10][11][12][13] Interestingly, several recent cadaveric [14][15][16] and in vivo 17,18 studies have linked altered joint mechanics to reconstruction techniques that fail to place the graft within the footprint of the native ACL, thereby changing the orientation and corresponding biomechanical function of the ACL.…”

“…[7][8][9] Consequently, anatomic placement of the ACL graft has received increasing attention as a potential critical factor in the future success of the procedure. Although there is not currently a consensus on the optimal surgical technique to achieve anatomic graft placement, most authors support modifications to the transtibial technique 26,28 or independent drilling of the tibial and femoral tunnels 24,25,27,29 in order to more accurately place the graft in the center of the native ACL footprint, with particular focus on the femoral graft position.…”

Basic biomechanic principles of knee instability

“…After the first historical description of the test by Galway and MacIntosh [30], many other variations have been described by physicians and researchers [31][32][33]. However, research has documented that the interpretation of the pivot shift test remains subjective and examiner dependent [17,[34][35][36][37]. The attempt of quantifying the pivot shift test has proven difficult given the multiple techniques for the exam and the associated large variation in kinematics [37].…”