Tibial rotation during pivoting in anterior cruciate ligament reconstructed knees using a single bundle technique

Systematic Review of Surgical Technique and Tunnel Target Points and Placement in Anatomical Single-Bundle ACL Reconstruction

The purpose of this systematic review was to reveal the trend in surgical technique and tunnel targets points and placement in anatomical single-bundle anterior cruciate ligament (ACL) reconstruction. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, data collection was performed. PubMed, EMBASE, and Cochran Review were searched using the terms "anterior cruciate ligament reconstruction," "anatomic or anatomical," and "single bundle." Studies were included when they reported clinical results, surgical technique, and/or tunnel placement evaluation. Laboratory studies, technical reports, case reports, and reviews were excluded from this study. From these full article reviews, graft selection, method of creating the femoral tunnel, and femoral and tibial tunnel target points and placement were evaluated. In the 79 studies included for data evaluation, the selected grafts were: bone patella tendon bone autograft (12%), and hamstring autograft (83%). The reported methods of creating the femoral tunnel were: transportal technique (54%), outside-in technique (15%), and transtibial technique (19%). In the 60 studies reporting tunnel target points, the target point was the center of the femoral footprint (60%), and the center of the anteromedial bundle footprint (22%). In the 23 studies evaluating tunnel placement, the femoral tunnel was placed in a shallow-deep direction (32.3%) and in a high-low direction (30.2%), and the tibial tunnel was placed from the anterior margin of the tibia (38.1%). The results of this systematic review revealed a trend in anatomical single-bundle ACL reconstruction favoring a hamstring tendon with a transportal technique, and a tunnel target point mainly at the center of the ACL footprint. The level of evidence stated is Systematic review of level-III studies.

A meta-analysis on anterior cruciate ligament reconstruction: Is modified transtibial technique inferior to independent drilling techniques?

This report respectively compared the standard transtibial (sTT) technique to the independent drilling (ID) techniques applied to anterior cruciate ligament (ACL) reconstruction. It also made a comparison between the clinical results of the modified transtibial (mTT) technique and of the ID techniques. Prospective studies on transtibial (TT) and ID techniques for ACL reconstruction were retrieved from several databases and a subgroup analysis was performed to compare the sTT technique with the ID techniques and the mTT with the ID techniques. Furthermore, comparison of the Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC) subjective and objective evaluations, Lysholm score and Tegner activity scale were conducted. This report included 12 clinical studies that involved 681 patients having received ACL reconstruction. The study results indicated that in comparison between the sTT and ID techniques, the ID techniques outperformed the sTT technique in the IKDC subjective score (P=0.01) and laxity (P=0.0004). However, there was no significant difference in the IKDC objective score (P=0.34), pivot-shift test (P=0.24), Lachman test (P=0.21), Lysholm score (P=0.14) and Tegner activity scale (P=0.66). The comparison between the new mTT technique and the ID techniques suggested no significant difference in the IKDC objective and subjective scores (P=0.86), laxity (P=0.38), pivot-shift test (P=0.66), Lachman test (P=0.10), Lysholm score (P=0.10) and Tegner activity scale (P=0.55). Compared to the sTT technique, the mTT and ID techniques are more suitable for ACL reconstruction because they can present better subjective feelings. Moreover, considering that the TT technique is familiar to surgeons and the mTT technique can bring favorable subjective feelings and objective clinical outcomes, the mTT technique shows greater utilization potential.

Landing strategies focusing on the control of tibial rotation in the initial contact period of one-leg forward hops

Anterior cruciate ligament (ACL) reconstruction (ACLR) surgeries successfully restore anterior tibial translation but not tibial rotation. This study aimed to explore landing strategies focusing on the control of tibial rotation at landing when the ACL is most vulnerable. Three groups of male subjects (50 ACLRs, 26 basketball players, and 31 controls) participated in one-leg forward hop tests for determining the tibial rotatory landing strategies adopted during the initial landing phase. The differences in knee kinematics and muscle activities between internal and external tibial rotatory (ITR, ETR) landing strategies were examined. A higher proportion of basketball players (34.6%) were found to adopt ITR strategies (controls: 6.5%), exhibiting significantly greater hopping distance and knee strength. After adjusting for hopping distance, subjects adopting ITR strategies were found to hop faster with straighter knees at foot contact and with greater ITR and less knee adduction angular displacement during the initial landing phase. However, significantly greater angular displacement in knee flexion, greater medial hamstring activities, and greater co-contraction index of hamstrings and medial knee muscles were also found during initial landing. Our results support the importance of the recruitments of medial hamstrings or the local co-contraction in assisting the rotatory control of the knee during initial landing for avoiding ACL injuries.

The effect of anterior cruciate ligament graft orientation on rotational knee kinematics

PURPOSE

To determine whether coronal graft orientation and tunnel placement for single-bundle anterior cruciate ligament (ACL) reconstruction is associated with tibial rotation excursion during functional activities.

METHODS

Eighty-four patients who had undergone ACL reconstruction over a ten-year time span had tibial rotation measured during level walking, using a three-dimensional motion analysis system. Fifty-two patients also had measures taken during the more dynamic task of single-limb landing. During the 10-year period, the position of the graft was deliberately changed from a vertical to more horizontal orientation in the coronal plane. Post-operative radiographs were analysed for the coronal graft orientation and femoral and tibial tunnel positions. Radiographic measurements of graft orientation and tunnel position were then correlated with the amount of tibial rotational excursion recorded during the walking and landing tasks.

RESULTS

For the single-limb landing task, a significant positive correlation was observed between the coronal graft angle and rotational excursion (R = 0.35, R (2)  = 0.12, p = 0.01). This indicated greater rotational excursion was associated with vertical graft orientation, but only explained 12 % of the variance. No correlations were found between coronal graft angle and tibial rotation during level walking.

CONCLUSIONS

These findings support the notion that ACL graft orientation may play a role in rotational kinematics of the ACL-reconstructed knee, particularly during higher impact activities.

LEVEL OF EVIDENCE

IV.

The effect of knee braces on tibial rotation in anterior cruciate ligament-deficient knees during high-demand athletic activities

OBJECTIVE

To examine if bracing can restrict tibial rotation in anterior cruciate ligament (ACL)-deficient patients during high loading activities.

DESIGN

Repeated measures. Kinematic data were collected with an 8-camera Vicon system while each patient performed 2 tasks that are known to cause increased rotational and translational loads on the knee: (1) descending from a stair and subsequent pivoting, and (2) landing from a platform and subsequent pivoting. The tasks were repeated under 3 brace conditions for the ACL-deficient knee: (1) wearing a prophylactic brace (braced condition), (2) wearing a patellofemoral brace (sleeved condition), and (3) without brace (unbraced condition).

SETTING

Biomechanical laboratory study.

PATIENTS

Twenty-one male subjects with a confirmed unilateral ACL rupture were assessed in vivo.

MAIN OUTCOME MEASURES

Tibial internal rotation. Two repeated measures ANOVAs tested for differences in tibial internal rotation among the 3 conditions of the ACL-deficient knee and the unbraced condition of the intact knee.

RESULTS

In both tasks, tibial rotation was significantly lower in the intact knee compared with all 3 conditions of the ACL-deficient knee (P ≤ 0.031). Bracing the ACL-deficient knee resulted in lower rotation than the unbraced (P ≤ 0.001) and sleeved (P ≤ 0.033) conditions. The sleeved condition resulted in lower tibial rotation in the drop landing and pivoting task compared with the unbraced condition (P = 0.019) but not in the stair descending and pivoting task (P = 0.256).

CONCLUSIONS

Bracing decreased the excessive tibial rotation in ACL-deficient patients during high-demand activities but failed to fully restore normative values. If knee braces can enhance rotational knee stability in ACL-deficient patients, then they could possibly play an important role in preventing further knee pathology in such patients.

Hamstring tendon anterior cruciate ligament reconstruction: does gracilis tendon harvest matter?

PURPOSE

Hamstring tendon grafts are a popular choice for anterior cruciate ligament (ACL) reconstruction. Typical morbidity reported after hamstring tendon harvest is muscle weakness in flexion, and whilst still a matter for debate, this morbidity may be greater if the gracilis tendon is harvested in addition to the semitendinosus. This study sought to comprehensively compare the outcome of ACL reconstructions in which the semitendinosus was harvested alone (ST group) or with the gracilis (ST/G group).

METHODS

Twenty patients (ten ST, ten ST/G) were assessed with a variety of measures that included subjective scores, function, strength and tibial rotation as measured by gait analysis during a pivoting task.

RESULTS

Results showed that the graft diameter was significantly larger in the ST group, but there were no other differences between the groups for any other outcome measure.

CONCLUSION

Harvesting the gracilis in addition to semitendinosus does not appear to affect either the outcome or graft-related morbidity after hamstring ACL reconstruction.