Effect of Initial Graft Tension During Anterior Talofibular Ligament Reconstruction on Ankle Kinematics, Laxity, and In Situ Forces of the Reconstructed Graft

Biomechanical assessment of ligament maturation after arthroscopic ligament reconstruction of the anterior talofibular ligament

BACKGROUND

Many techniques have been described for lateral ankle ligament reconstruction. Although the biomechanical properties of gracilis tendons are different from those of ligaments, the use of a gracilis tendon autograft is a popular option for anatomical reconstruction. Graft maturation and the biomechanical processes over time remain unclear. This study describes changes in graft stiffness following anterior talofibular ligament (ATFL) reconstruction and graft reaction to varus stress.

HYPOTHESIS

The reconstruction would be stiffer than the native ATFL, but would decrease during follow-up.

METHODS

Twenty patients were prospectively included after arthroscopic reconstruction of the ATFL and calcaneofibular ligament for ankle stabilization. All patients were followed up 3, 6, and 12 months after surgery to assess graft stiffness by shear wave elastography (SWE) at different angles of varus in the ankle. At one year the EFAS and AOFAS functional scores were obtained. A control group of twenty healthy subjects were included to compare graft stiffness to that of a native ATFL.

RESULTS

The stiffness of the native ATFL in the control group was 12.8 +/- 2.4 kPa in neutral position, 18.4 +/- 4.8 kPa at 15 ° of varus, 31.9 +/- 6.6 kPa at 30 ° of varus. One year after surgery, graft stiffness was statistically higher and averaged 56 +/- 9 kPa, 70.2 +/- 11.6 kPa and 84.9 +/- 10.5 kPa, respectively. Postoperative graft stiffness at three, six, and twelve months was not correlated with any of these scores, reflecting patient satisfaction and good function at one year.

CONCLUSION

Graft stiffness decreases over time but remains four times stiffer than that of a native ATFL at one year in the neutral position. ATFL graft stiffness at one year during varus stress appears to be different from that of a native ATFL.

LEVEL OF EVIDENCE

III.

Broström ankle ligament repair augmented with suture tape : Results of magnetic resonance imaging evaluation

BACKGROUND

The Broström procedure is an established procedure in cases of primary lateral ankle ligament repair (LALR). To improve postoperative stability an augmentation device, InternalBrace™ (Arthrex, Naples, FL) has been introduced. This study evaluates remodelling of the anterior talofibular ligament (ATFL) in patients undergoing a tape augmented Broström technique as well as clinical outcomes.

METHODS

In this study 32 patients with chronic lateral ankle instability (CLAI) receiving augmented LALR were included. Clinical outcomes were evaluated at a one-time postoperative visit between 12 and 18 months. A 3 T magnetic resonance imaging (MRI) was done to evaluate the morphology of the ATFL. Statistical analysis was completed with the free software and environment R version 3.6.3 (Bell Laboratories, Murray Hill, NJ, USA) and P-values < 0.05 were considered statistically significant.

RESULTS

The mean follow-up time was 15.3 ± 1.8 months with a return to sport time of 4.0 ± 2.4 months. The average AOFAS (American Orthopaedic Foot and Ankle Society Score) score was 94.4 ± 7.2, the FAOS (Foot and Ankle Outcome Score) demonstrated 87.3 ± 10.4 points and the FFI (Foot Function Index - 2 scores (pain and function score)) was 22.9 ± 20.1 and 15.4 ± 10.4, respectively. The MRI findings demonstrated an average length of the ATFL of 18.6 ± 4.3 mm and the width was 3.6 ± 0.9 mm. A clear differentiation between the ATFL and the augmentation device could be shown in 28 cases. The Fisher's exact test could not depict a significant correlation between the presence of a bone marrow edema and the tension of the augmentation device with a level of significance of α = 0.05.

CONCLUSION

An anatomical healing tendency of the ligament repair and good integrity of the augmentation device could be shown based on MRI findings. The lateral ligament repair augmented with suture tape is an effective and safe procedure regarding surgical treatment in chronic lateral ankle instability producing good clinical outcome.

Optimal assessment for anterior talofibular ligament injury utilizing stress ultrasound entails internal rotation during plantarflexion

OBJECTIVES

An optimal load and ankle position for stress ultrasound of the injured anterior talofibular ligament (ATFL) are unknown. The objectives of this study were to compare stress ultrasound and ankle kinematics from a 6 degree-of-freedom (6-DOF) robotic testing system as a reference standard for the evaluation of injured ATFL and suggest cut-off values for ultrasound diagnosis.

METHODS

Ten fresh-frozen human cadaveric ankles were used. Loads and ankle positions examined by the 6-DOF robotic testing system were: 40 N anterior load, 1.7 Nm inversion, and 1.7 Nm internal rotation torques at 30° plantarflexion, 15° plantarflexion, and 0° plantarflexion. Bony translations were measured by ultrasound and a robotic testing system under the above conditions. After measuring the intact ankle, ATFL was transected at its fibular attachment under arthroscopy. Correlations between ultrasound and robotic testing systems were calculated with Pearson correlation coefficients. Paired t-tests were performed for comparison of ultrasound measurements of translation between intact and transected ATFL and unloaded and loaded conditions in transected ATFL.

RESULTS

Good agreement between ultrasound measurement and that of the robotic testing system was found only in internal rotation at 30° plantarflexion (ICC ​= ​0.77; 95% confidence interval 0.27-0.94). At 30° plantarflexion, significant differences in ultrasound measurements of translation between intact and transected ATFL (p ​< ​0.01) were found in response to 1.7 Nm internal rotation torque and nonstress and stress with internal rotation (p ​< ​0.01) with mean differences of 2.4 ​mm and 1.9 ​mm, respectively.

CONCLUSION

Based on the data of this study, moderate internal rotation and plantarflexion are optimal to evaluate the effects of ATFL injury when clinicians utilize stress ultrasound in patients.

LEVEL OF EVIDENCE

III.

Investigation into the effect of deltoid ligament injury on rotational ankle instability using a three-dimensional ankle finite element model

Background

Injury to the lateral collateral ligament of the ankle may cause ankle instability and, when combined with deltoid ligament (DL) injury, may lead to a more complex situation known as rotational ankle instability (RAI). It is unclear how DL rupture interferes with the mechanical function of an ankle joint with RAI.

Purpose

To study the influence of DL injury on the biomechanical function of the ankle joint.

Methods

A comprehensive finite element model of an ankle joint, incorporating detailed ligaments, was developed from MRI scans of an adult female. A range of ligament injury scenarios were simulated in the ankle joint model, which was then subjected to a static standing load of 300 N and a 1.5 Nm internal and external rotation torque. The analysis focused on comparing the distribution and peak values of von Mises stress in the articular cartilages of both the tibia and talus and measuring the talus rotation angle and contact area of the talocrural joint.

Results

The dimensions and location of insertion points of ligaments in the finite element ankle model were adopted from previous anatomical research and dissection studies. The anterior drawer distance in the finite element model was within 6.5% of the anatomical range, and the talus tilt angle was within 3% of anatomical results. During static standing, a combined rupture of the anterior talofibular ligament (ATFL) and anterior tibiotalar ligament (ATTL) generates new stress concentrations on the talus cartilage, which markedly increases the joint contact area and stress on the cartilage. During static standing with external rotation, the anterior talofibular ligament and anterior tibiotalar ligament ruptured the ankle's rotational angle by 21.8% compared to an intact joint. In contrast, static standing with internal rotation led to a similar increase in stress and a nearly 2.5 times increase in the talus rotational angle.

Conclusion

Injury to the DL altered the stress distribution in the tibiotalar joint and increased the talus rotation angle when subjected to a rotational torque, which may increase the risk of RAI. When treating RAI, it is essential to address not only multi-band DL injuries but also single-band deep DL injuries, especially those affecting the ATTL.

Anatomic reconstruction using the autologous gracilis tendon achieved less sprain recurrence than the Broström-Gould procedure but delayed recovery in chronic lateral ankle instability

PURPOSE

To compare the return-to-activity and long-term clinical outcomes between anatomic lateral ligament reconstruction using the autologous gracilis tendon and modified Broström-Gould (MBG) procedure in chronic lateral ankle instability (CLAI). It was hypothesised that there was no difference between the two techniques.

METHODS

From 2013 to 2018, 30 CLAI patients with grade III joint instability confirmed by anterior drawer test underwent anatomic reconstruction of lateral ankle ligament with the autologous gracilis tendon (reconstruction group) in our institute. Another 30 patients undergoing MBG procedure (MBG group) were matched in a 1:1 ratio based on demographic parameters. The post-operative American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) pain score, Tegner activity score, Karlsson-Peterson score, surgical complications, return-to-activities and work were retrospectively evaluated and compared between the two groups.

RESULTS

All subjective scores significantly improved after the operation (all with p < 0.001) without difference between the two groups (all n.s.). The MBG group showed a significantly higher proportion of postoperative sprain recurrence than the reconstruction group (26.7% vs. 0, p = 0.002). The reconstruction group showed a significantly longer period to start walking with full weight-bearing (10.5 ± 6.9 vs. 7.0 ± 3.1 weeks, p = 0.015), jogging (17.1 ± 8.9 vs. 12.7 ± 6.9 weeks, p = 0.043) and return-to-work (13.5 ± 12.6 vs. 8.0 ± 4.7 weeks, p = 0.039) than the MBG group.

CONCLUSIONS

Both anatomic reconstruction using the autologous gracilis tendon and MBG procedure could equally achieved reliable long-term clinical outcomes and the tendon reconstruction showed a relatively lower incidence of postoperative sprain recurrence but delayed recovery to walking, jogging and return-to-work. The MBG procedure was still the first choice with rapid recovery but the tendon reconstruction was recommended for patients with higher strength demand.

LEVEL OF EVIDENCE

III.

The optimal tension for the reconstruction of the distal radioulnar ligaments

PURPOSE

This study aimed to investigate the optimal tension for the reconstruction of the distal radioulnar ligaments (DRULs) in the treatment of the distal radioulnar joint (DRUJ) instability.

METHODS

A total of eight human cadaver upper extremities were used. First, the Tekscan sensor film system was used to measure the contact characteristics of the intact DRUJ. Following this, the DRULs were resected, and the measurement was repeated. The DRULs were then reconstructed according to Adams' procedure, and the contact forces under different initial tension were compared with that of the intact group to obtain the optimal tension. At that point, the contact force of the DRUJ was close to normal. The reliability of the obtained tension was verified by translational testing, which reflected the stability of the DRUJ.

RESULTS

In the neutral position, the contact force, area, and pressure inside DRUJ were 0.51 ± 0.10 N, 64.08 ± 11.58 mm², and 8.33 ± 2.42 kPa, respectively. After the DRULs were resected, they were 0.19 ± 0.02 N, 41.75 ± 5.01 mm², and 4.86 ± 1.06 kPa, respectively. The relationship between the tension and contact force was linear regression (Y = 0.0496x + 0.229, R² = 0.9575, P < 0.0001). According to the equation, when the tension was 3.64-7.68 N, the contact force was close to normal. There was no statistical difference in the stability of the reconstructed DRUJ under this tension compared with the intact group (P = 0.08).

CONCLUSION

By comparing the contact forces under different reconstruction tensions with the normal value, we obtained the optimal tension, which can provide the theoretical basis for the clinical treatment of chronic DRUJ instability.

Effect of Accelerated Rehabilitation on Early Return to Sport After Arthroscopic Ankle Lateral Ligament Repair

Background

Although the minimal invasiveness of arthroscopic ankle lateral ligament repair (ALLR) means that an early return to sporting activities can be anticipated, studies have described postoperative cast immobilization and the avoidance of weightbearing for a certain period. Accelerated rehabilitation may be helpful for an early return to sport.

Purpose

To investigate clinical outcomes of ALLR and accelerated rehabilitation with a minimum duration of postoperative ankle immobilization and proactive early weightbearing.

Study Design

Case series; Level of evidence, 4.

Methods

This study investigated 23 ankles of 22 patients (11 men, 11 women; mean age, 38.7 years) who underwent ALLR for chronic lateral ankle instability. Postoperative management included the avoidance of weightbearing until postoperative day 3, after which full weightbearing walking with a brace was permitted. The objective was to return to competitive sport 8 weeks after surgery. The following were evaluated: pre- and postoperative instability and pain symptoms, ankle range of motion, anterior drawer distance on stress radiograph, anterior translation measured with a capacitance-type strain sensor, the Ankle-Hindfoot Scale from the Japanese Society for Surgery of the Foot, and the SAFE-Q (Self-Administered Foot Evaluation Questionnaire).

Results

Two male patients dropped out and were excluded from analysis. Postoperatively, instability and pain resolved or improved in all patients. There was no significant postoperative change in range of motion. There were significant pre- to postoperative improvements in talar tilt angle (from 12.2°-5.6°, P < .01), anterior drawer distance (8.2-4.4 mm, P < .01), and anterior translation (10.5-4.6 mm, P < .01) as well as the Ankle-Hindfoot Scale score (68.8-96.8, P < .01) and all subscales of the SAFE-Q (P ≤ .01 for all). Complete return to sport was achieved by 75% of the patients at 8 weeks postoperatively.

Conclusion

When accelerated rehabilitation with proactive weightbearing exercises was implemented from postoperative day 3 without ankle immobilization after ALLR, there were significant improvements in objective assessments of ankle stability and clinical scores, and as many as 75% of the patients were able to make a complete return to sport within 8 weeks.

Biomechanical evaluation of interference screw fixation techniques for distal radioulnar ligament reconstruction: a cadaveric experimental study

INTRODUCTION

In the reconstruction of distal radioulnar ligaments (DRULs), interference screws can be used for antegrade or retrograde fixation of grafts to the ulna. However, the biomechanics of interference screw fixation are currently unknown. This study aimed to determine the biomechanical effects of these two fixations on the distal radioulnar joint (DRUJ) in a cadaveric model and to investigate the appropriate initial tension.

MATERIALS AND METHODS

A total of 30 human cadaver upper extremities were used, and the DRULs were reconstructed according to Adams' procedure. First, eight specimens were randomly divided into two groups: antegrade and retrograde, followed by translational testing and load testing. Then, the other eight specimens were divided into the two groups above, and the contact mechanics, including forces, areas, and pressures, were measured. Finally, to investigate the appropriate initial tension, the remaining 14 specimens were fixed with interference screws under different tensions in an antegrade way, and the translational testing was repeated as before.

RESULTS

In the neutral position, antegrade fixation exhibited less translation than retrograde fixation (7.21 ± 0.17 mm versus 10.77 ± 1.68 mm, respectively). The maximum failure load was 70.45 ± 6.20 N in antegrade fixation, while that in retrograde fixation was 35.17 ± 2.95 N (P < 0.0001). Antegrade fixation exhibited a larger increase in contact force than retrograde fixation (99.72% ± 23.88% versus 28.18% ± 10.43%) (P = 0.001). The relationship between tension and displacement was nonlinear (Y = - 1.877 ln(x) + 7.94, R² = 0.868, P < 0.0001).

CONCLUSIONS

Compared with retrograde fixation, the antegrade fixation of interference screws may be a more reliable surgical technique, as it shows a higher failure load and stability. In addition, to avoid the risk of potential arthritis caused by anterograde fixation, we propose an equation to determine the appropriate initial tension in DRUL reconstruction.

Ultrasound-Guided Anterior Talofibular Ligament Repair With Augmentation Can Restore Ankle Kinematics: A Cadaveric Biomechanical Study

Background:

Anterior talofibular ligament (ATFL) repair of the ankle is a common surgical procedure. Ultrasound (US)-guided anchor placement for ATFL repair can be performed anatomically and accurately. However, to our knowledge, no study has investigated ankle kinematics after US-guided ATFL repair.

Hypothesis:

US-guided ATFL repair with and without inferior extensor retinaculum (IER) augmentation will restore ankle kinematics.

Study Design:

Controlled laboratory study; Level of evidence, 4.

Methods:

A 6 degrees of freedom robotic testing system was used to apply multidirectional loads to fresh-frozen cadaveric ankles (N = 9). The following ankle states were evaluated: ATFL intact, ATFL deficient, combined ATFL repair and IER augmentation, and isolated US-guided ATFL repair. Three loading conditions (internal-external rotation torque, anterior-posterior load, and inversion-eversion torque) were applied at 4 ankle positions: 30° of plantarflexion, 15° of plantarflexion, 0° of plantarflexion, and 15° of dorsiflexion. The resulting kinematics were recorded and compared using a 1-way repeated-measures analysis of variance with the Benjamini-Hochberg test.

Results:

Anterior translation in response to an internal rotation torque significantly increased in the ATFL-deficient state compared with the ATFL-intact state at 30° and 15° of plantarflexion (P = .022 and .03, respectively). After the combined US-guided ATFL repair and augmentation, anterior translation was reduced significantly compared with the ATFL-deficient state at 30° and 15° of plantarflexion (P = .0012 and .005, respectively). Anterior translation was not significantly different for the isolated ATFL-repair state compared with the ATFL-deficient or ATFL-intact states at 30° and 15° of plantarflexion.

Conclusion:

Combined US-guided ATFL repair with augmentation of the IER reduced lateral ankle laxity due to ATFL deficiency. Isolated US-guided ATFL repair did not reduce laxity due to ATFL deficiency, nor did it increase instability compared with the intact ankle.

Clinical Relevance:

US-guided ATFL repair with IER augmentation is a minimally-invasive technique to reduce lateral ankle laxity due to ATFL deficiency. Isolated US-guided ATFL repair may be a viable option if accompanied by a period of immobilization.

Effects of the Ankle Flexion Angle During Anterior Talofibular Ligament Reconstruction on Ankle Kinematics, Laxity, and In Situ Forces of the Reconstructed Graft

BACKGROUND

This study aimed to evaluate the effects of the ankle flexion angle during anterior talofibular ligament (ATFL) reconstruction on ankle kinematics, laxity, and in situ force of a graft.

METHODS

Twelve cadaveric ankles were evaluated using a 6-degrees of freedom robotic system to apply passive plantar flexion and dorsiflexion motions and multidirectional loads. A repeated measures experiment was designed using the intact ATFL, transected ATFL, and reconstructed ATFL. During ATFL reconstruction (ATFLR), the graft was fixed at a neutral position (ATFLR 0 degrees), 15 degrees of plantar flexion (ATFLR PF15 degrees), and 30 degrees of plantar flexion (ATFLR PF30 degrees) with a constant initial tension of 10 N. The 3-dimensional path and reconstructed graft tension were simultaneously recorded, and the in situ force of the ATFL and reconstructed grafts were calculated using the principle of superposition.

RESULTS

The in situ forces of the reconstructed grafts in ATFLR 0 degrees and ATFLR PF 15 degrees were significantly higher than those of intact ankles. The ankle kinematics and laxity produced by ATFLR PF 30 degrees were not significantly different from those of intact ankles. The in situ force on the ATFL was 19.0 N at 30 degrees of plantar flexion. In situ forces of 41.0, 33.7, and 21.9 N were observed at 30 degrees of plantar flexion in ATFLR 0, 15, and 30 degrees, respectively.

CONCLUSION

ATFL reconstruction with the peroneus longus (PL) tendon was performed with the graft at 30 degrees of plantar flexion resulted in ankle kinematics, laxity, and in situ forces similar to those of intact ankles. ATFL reconstructions performed with the graft fixed at 0 and 15 degrees of the plantar flexion resulted in higher in situ forces on the reconstructed graft.

CLINICAL RELEVANCE

Fixing the ATFL tendon graft at 30 degrees of plantar flexion results in an in situ force closest to that of an intact ankle and avoids the excessive tension on the reconstructed graft.