Suture tape augmentation of the lateral ulnar collateral ligament increases load to failure in simulated posterolateral rotatory instability

A comparative analysis of suture-augmented and standard hamstring autograft single-bundle ACL reconstruction outcomes: short-term functional benefits without long-term impact

BACKGROUND

Augmentation of the biologic graft with nonabsorbable suture material during anterior cruciate ligament reconstruction (ACLR) is a relatively new technique to enhance its biomechanical properties and add additional support to the critical process of healing. We aimed to compare the short-term functional patient-reported outcome measures (PROMs) and complication rates of patients treated with either standard single-bundle four-strand hamstring ACLR or added suture augmentation (SA).

METHODS

Patients undergoing arthroscopic ACLR between February 2015-January 2017 and in the standard ACLR group, and between February 2017-September 2019 in the SA-ACLR group operated by adding a no.5 FiberWire® (Arthrex, Naples, FL, USA) braided suture to the hamstring autograft, were retrospectively reviewed and the PROMs were compared. Patients were followed up for a 24-month period and PROMs were assessed by the International Knee Documentation Committee (IKDC) Subjective Knee Form and Tegner-Lysholm knee score. Patients' demographic and clinical characteristics, and postoperative complications including graft retear requiring revision surgery, deep vein thrombois, and surgical site infection were recorded and analyzed.

RESULTS

We included 79 patients with mean age of 31.6 ± 8.3 years in the standard ACLR group, and 90 patients with mean oge of 30.5 ± 7.6 in the SA-ACLR group. There was no statistically significant difference between the two groups in terms of age, sex, body mass index, and medical comorbidities. The values of the IKDC scores increased to 75.8 ± 18.9 in the standard ACLR group, and 85.6 ± 12.6 in the SA-ACLR group, 24 months after the operation (P < 0.05). The 24-month postoperative Tegner-Lysholm scores escalated to 79.3 ± 21.0 in the standard ACLR group and 91.0 ± 13.7 in the SA-ACLR group (P < 0.05). Four (5.1%) patients in the standard ACLR group and 4 (4.4%) in the SA-ACLR group experienced graft retear requiring revision surgery (P > 0.05). Incidence of surgical site infection and deep vein thrombosis showed no significant differences between the two groups, 24 months after ACLR.

CONCLUSION

SA-ACLR is associated with improved short-term functional PROMs compared to the standard hamstring ACLR. Although SA did not reduce the retear rate, and infection and DVT rates did not differ between study groups, superior improvement of PROMs in SA approach, leverages this method for ACLR.

The effect of lateral collateral ligament repair tension on elbow stability: An in vitro biomechanical study

BACKGROUND

The aim of this study was to determine the optimal repair tension of the lateral collateral ligament of the elbow by performing simulated active flexion with the arm in the varus gravity loaded position using an in vitro elbow simulator.

METHODS

Eight cadaveric specimens were mounted in the varus gravity loaded orientation onto an elbow motion simulator. Four states were studied (intact, lateral collateral ligament injured, and 15 N and 20 N lateral collateral ligament repairs) with the forearm in supination and pronation. An electromagnetic tracking system was used to measure joint kinematics during active elbow flexion.

FINDINGS

There was no difference in ulnohumeral rotation between the intact state and the 15 N repair (P = .150 for pronation; P = 1.0 for supination) or the 20 N repair (P = 1.0 for pronation; P = .568 for supination). For varus-valgus angulation, the 20 N repair was not statistically different from the intact state (P = .059 in pronation; P = 1.0 in supination).

INTERPRETATION

Repair of the lateral collateral ligament following injury can restore joint kinematics with the arm in the varus position. A repair tension of 20 N was successful in restoring joint stability for simulated active motion with the forearm in pronation and supination. This study shows that when the lateral collateral ligament is repaired with adequate tension, avoidance of the varus position may not be as crucial during early motion.

Testing of a Novel Method for Securing Ligaments Against Bone During Simultaneous Medial and Lateral Elbow Ligament Reconstruction

PURPOSE

A ligament reconstruction method that simultaneously tensions the medial and lateral sides of the elbow and maintains tension with compression plates on the proximal ulna is proposed for the treatment of bidirectional elbow ligament instability. Graft slippage, catastrophic failure, and excessive displacement were evaluated. Biomechanical stability without graft slippage was hypothesized.

METHODS

Eight cadaveric ligament reconstruction simulations were created through the dissection of three cadaver arms. Each reconstruction was statically tested with 160 N in a manner where it was first augmented with an absorbable suture and then without. Then, 3 more ligament reconstruction simulations were created for dynamic testing with each undergoing testing at 80 N for 2,000 cycles at 2 Hz. Construct displacement and graft slippage were recorded for each load application.

RESULTS

No grafts failed catastrophically and no graft slippage was observed with either static or dynamic loading. Under static loading, the mean change in displacement between augmented and nonaugmented ligament reconstruction simulations was 28.7% ± 21% (augmented 3.95 ± 1.81 mm vs nonaugmented 4.89 ± 2.22 mm). The mean stiffness was 66.6 ± 26.6 N/mm for augmented and 64.6 ± 23.2 N/mm for nonaugmented simulations. With dynamic loading, the mean displacement for augmented graft ligament reconstruction simulations was 1.55 ± 0.16 mm compared with 2.18 ± 0.77 mm for nonaugmented reconstruction simulations.

CONCLUSIONS

This method of fixation to the proximal ulna for the simultaneous reconstruction of medial and lateral elbow ligaments successfully prevented graft slippage without excessive construct displacement during static and dynamic testing. Ligament augmentation with absorbable sutures decreased the construct displacement.

CLINICAL RELEVANCE

This ligament fixation method may be a viable alternative for the treatment of concomitant medial and lateral elbow instability.

Biomechanical Stability of Lateral Ulnar Collateral Ligament Reconstruction and Repair of the Elbow: The Role of Ligament Bracing on Gap Formation and Stabilization

BACKGROUND

Augmented (internal braced) lateral ulnar collateral ligament (LUCL) repair has been biomechanically compared with reconstruction techniques in the elbow. However, LUCL repair alone has not yet been compared with augmented repair and reconstruction techniques.

HYPOTHESIS

Internal bracing of LUCL repair would improve time-zero stabilization regarding gap formation, stiffness, and residual torque as compared with repair alone and reconstruction techniques to restore native elbow stability.

STUDY DESIGN

Controlled laboratory study.

METHODS

Overall, 24 cadaveric elbows were used for either internal braced LUCL repair (Repair-IB) or single- and double-strand ligament reconstruction with triceps (Recon-TR) and palmaris longus tendon graft (Recon-PL), respectively. Laxity testing in external rotation was consecutively performed at 90° of elbow flexion on the intact, dissected, and repaired conditions and with the previously assigned techniques. First, intact elbows were loaded to 7.0-N·m external torque to evaluate time-zero ligament rotations at 2.5, 4.0, 5.5, and 7.0 N·m. Rotation-controlled cycling was performed (total of 1000 cycles) for each surgical condition. Gapping, stiffness, and residual torque were analyzed. Finally, these and 8 additional intact elbows underwent torque-to-failure testing (30 deg/min).

RESULTS

The dissected state showed the highest gap formation and lowest peak torques (P < .001). While gap formation of Repair-IB (P < .021) was significantly lower than that of repair without internal bracing at all rotation levels, gaps of Recon-PL were similar to and Recon-TR were significantly higher than those of Repair-IB except for the highest torsion level. Residual peak torques at specific rotation angles between native state and Recon-TR (α_2.5), Recon-PL (α_4.0), and Repair-IB (α_5.5) were similar; all other comparisons were significantly different (P < .027). Torsional stiffness of Repair-IB was significantly higher at all rotation angles measured. Analysis of covariance showed significantly less gap formation over residual peak torques for Repair-IB (P < .001) as compared with all other groups. The native state failure load was significantly higher than Recon-PL and Recon-TR failure loads, with similar stiffness to all other groups.

CONCLUSION

Repair-IB and Recon-PL of the LUCL showed increased rotational stiffness relative to the intact elbow for restoring posterolateral stability to the native state in a cadaveric model. Recon-TR demonstrated lower residual peak torques but provided near-native rotational stiffness.

CLINICAL RELEVANCE

Internal bracing of LUCL repair may reduce suture-tearing effects through tissue and provide sufficient stabilization for healing throughout accelerated and reliable recovery without the need for a tendon graft.

Locking suture repair versus ligament augmentation-a biomechanical study regarding the treatment of acute lateral collateral ligament injuries of the elbow

BACKGROUND

Lateral collateral ligament (LCL) tears are frequently observed in fractures and dislocations of the elbow. Recent biomechanical evidence suggests that additional ligament augmentation may improve repair stability. The aim of this biomechanical in-vitro study was to compare the resistance of a locking suture repair of the LCL with a ligament augmentation technique.

MATERIAL AND METHODS

Eight fresh frozen cadaveric elbows were evaluated for stability against varus/posterolateral rotatory forces (3 Nm). A strain gauge (µm/m; negative values) was placed at the origin and insertion of the lateral ulnar collateral ligament (LUCL) and cyclic loading was performed for 1000 cycles. We analyzed three distinct scenarios: (A) native LCL, (B) locking transosseou suture repair of the LCL, (C) simple LCL repair with additional ligament augmentation of the LUCL.

RESULTS

The mean measured strain was - 416.1 µm/m (A), - 618 µm/m (B) and - 288.5 µm/m (C) with the elbow flexion at 90°; the strain was significantly higher in scenario B compared to C (p = .01). During the cyclic load (1000) the mean measured strain was - 523.1 µm/m (B) and - 226.3 µm/m (C) with the elbow flexion at 60°; the strain was significantly higher in scenario B compared to C (p = .01). No significant difference between the first and the last cycles was observed (p = .09; p = .07). One failure of the LCL repair was observed after 1000 cycles; none of the ligament augmentations failed.

CONCLUSION

Ligament augmentation (C) provides higher resistance compared to the native LCL (A) and to the locking suture repair technique (B). Both techniques, however, hold up during 1000 cycles. While ligament augmentation might enhance the primary stability of the repair, future clinical studies have to show whether this increase in resistance leads to negative effects like higher rates of posttraumatic elbow stiffness.

LEVEL OF EVIDENCE

Basic science study, biomechanics.

Prospective clinical results of an additive ligament bracing for stabilizing simple and complex elbow instabilities

INTRODUCTION

Ligament bracing augments ligament repair using a non-absorbable suture tape. Although biomechanically an increase in primary stability has been proven, there is a lack of clinical evidence. Purpose of this study was to evaluate clinical results of patients treated with ligament bracing due to primary elbow instability, including an analysis of complications. Furthermore, clinical results for patients treated with and without early functional mobilization were compared.

MATERIALS AND METHODS

This prospective case-series evaluated clinical and functional results from patients treated with ligament bracing due to primary elbow instability. Clinical outcome measures were range of motion (ROM) as well as objective and subjective elbow scores [Mayo Elbow Performance Score (MEPS); Disabilities of Arm, Shoulder and Hand Score (DASH score)]. Stability was evaluated sonographically by humero-radial gapping under varus stress.

RESULTS

This study involved 34 patients treated with ligament bracing. After a mean follow-up of 12.9 months ROM was 112° ± 29, MEPS 88 ± 13 points, DASH 91 ± 11 points, and 84% were satisfied with their result. Lateral joint gapping was 2.4 mm. No significant difference was observed regarding a postoperative mobilization with and without limitations. Most common complication after ligament bracing was elbow stiffness including heterotopic ossifications in four patients (12%).

CONCLUSION

Operatively treated elbow instability with additional ligament bracing results in good clinical outcomes with high patient satisfaction and recovery of elbow stability. The high primary stability of the ligament bracing allows early functional mobilization without bracing, which facilitates postoperative rehabilitation. Elbow stiffness with heterotopic ossification seems to be a potential complication. Furthermore, the optimal tensioning of the ligament bracing remains challenging, including the risk of an over tensioning.

LEVEL OF EVIDENCE

III.

Biomechanical Comparison of Two Fixation Techniques for Lateral Ulnar Collateral Ligament Repair With Ligament Bracing

PURPOSE

Ligament bracing is a technique of suture reinforcement that can be used to augment lateral ulnar collateral ligament repair in the treatment of posterolateral rotatory instability of the elbow, thereby improving early stability of the repair. However, multiple failures of the ulnar anchor during implantation have been documented. We hypothesized that the use of a cortical button for ulnar fixation of the ligament brace would be biomechanically comparable to a suture anchor construct.

METHODS

Sixteen elbows were tested with a materials testing machine. The intact, dissected, and repaired lateral collateral ligament complex was tested with a cyclic varus rotational torque of 0.5-3.5 Nm in 120°, 90°, 60°, and 30° elbow flexion. For the repair, the specimens were randomized into 2 groups: ulnar fixation of the ligament bracing using a suture anchor and ulnar fixation of the ligament bracing using a cortical button. The number of implant failures was documented. A load-to-failure protocol was conducted in 90° elbow flexion.

RESULTS

Load to failure was comparable and was found to be 20.7 Nm in the suture anchor group and 21.8 Nm in the cortical button group. Laxity after ligament bracing did not differ significantly between suture anchor and cortical button fixation. Compared with the native ligament, the laxity was significantly reduced after ligament bracing. The failure mode was slippage of the suture tape through the humeral anchor in all cases. Additionally, the capitellum was damaged in 9 of 16 cases.

CONCLUSIONS

A cortical button for ulnar fixation of the ligament bracing was comparable with a suture anchor fixation with regard to biomechanical properties such as laxity and load to failure.

CLINICAL RELEVANCE

A cortical button fixation is less prone to failure of insertion. This would improve the implantation technique, while clinical results are expected to be comparable.

Elbow Osteochondral Allograft Transplantation and Lateral Ulnar Collateral Ligament Repair with Internal Brace: A Case Report

CASE

A 23-year-old woman with an Osborne-Cotterill lesion and posterolateral rotatory instability (PLRI) of the elbow was treated with osteochondral allograft transplantation (OCA) and lateral ulnar collateral ligament (LUCL) repair with internal brace. Two years after surgery, she reported resolution of pain and returned to all recreational activities. She reported no mechanical symptoms and no episodes of postoperative instability.

CONCLUSION

PLRI can present with an Osborne-Cotterill lesion in addition to LUCL injury. The purpose of this case report was to describe the use of OCA to manage bony defects in the capitellum in addition to LUCL repair for patients with PLRI.

Utilization of Internal Bracing in Elbow Medial UCL Stabilization: From Biomechanics to Clinical Application and Patient Outcomes

Ulnar collateral ligament (UCL) reconstruction has been successfully utilized to treat symptomatic UCL insufficiency in overhead athletes. Despite the overall success of the procedure, attempts have been made to improve upon the original technique with the goal of hastening return to sport. Most recently, there has been interest in repairing or reconstructing the native ligament with internal brace (IB) augmentation. Biomechanical cadaveric studies assessing UCL repair with IB augmentation have attempted to evaluate the efficacy of this treatment; however, the literature is seemingly divided on its benefit. Preliminary clinical studies suggest internal bracing may allow a faster return to sport than conventional techniques. The purpose of this review was to provide an analysis of the current evidence on IB augmentation in UCL repair of the elbow as it pertains to biomechanical advantages/disadvantages, reported surgical techniques, and clinical outcomes in comparison with traditional UCL reconstruction techniques.

Role of the transverse ligament of the ulnar collateral ligament of the elbow: a biomechanical study

Background

The ulnar collateral ligament (UCL) complex of the elbow plays a primary role in valgus and posteromedial stability of the elbow. The anterior oblique ligament (AOL) of the UCL is believed to provide the majority of resistance to external forces on the medial elbow. The transverse ligament (TL) of the UCL is generally thought to have minimal contribution to the elbow’s overall stability. However, recent studies have suggested a more significant role for the TL. The primary aim of this study was to identify the TL’s contribution to the stability of the elbow joint in determining the joint stiffness and neutral zone variation in internal rotation.

Methods

Twelve cadaveric elbows, set at a 90° flexion angle, were tested by applying an internal rotational force on the humerus to generate a medial opening torque at the level of the elbow. The specimens were preconditioned with 10 cycles of humeral internal rotation with sinusoidal torque ranging from 0 to 5 Nm. Elbow stiffness measures and joint neutral zone were first evaluated in its integrity during a final ramp loading. The test was subsequently repeated after cutting the TL at 33%, 66%, and 100% followed by the AOL in the same fashion.

Results

The native UCL complex joint stiffness to internal rotation measured 1.52 ± 0.51 Nm/°. The first observable change occurred with 33% sectioning of the AOL, with further sectioning of the AOL minimizing the joint stiffness to 1.26 ± 0.32 Nm/° (P = .004). A 33% resection of the TL found an initial neutral zone variation of 0.376 ± 0.23° that increased to 0.771 ± 0.41° (P < .01) at full resection. These values were marginal when compared with the full resection of the AOL for which we have found 3.69 ± 1.65° (P < .01).

Conclusion

The TL had no contribution to internal rotation elbow joint stiffness at a flexion angle of 90°. However, sequential sectioning of the TL was found to significantly increase the joint neutral zone when compared with the native cadaveric elbow at a flexion angle of 90°. This provides evidence toward the TL having some form of contribution to the elbow’s overall stability.

Biomechanical comparison of lateral collateral ligament reconstruction with and without additional internal bracing using a three-dimensional elbow simulator

BACKGROUND

Although an additional internal bracing significantly increases stability in a repair of the lateral ulnar collateral ligament, it remains unclear whether it also does in reconstruction. Aim of this study was to implement a three-dimensional elbow simulator for testing posterolateral rotatory instability. We hypothesized that (1) reconstruction with and without internal bracing is comparable in biomechanical properties, and (2) there would be higher load-to-failure with internal bracing.

METHODS

Posterolateral rotatory instability was tested by imitating the lateral pivot shift test in 16 elbows. Valgus and supination torques were simultaneously increased stepwise up to 1.2 Nm. Specimens were tested at 30°, 60°, 90°, and 120° elbow flexion with an intact lateral collateral ligament complex, dissected complex, and after reconstruction with or without internal bracing. Outcome measures included joint gapping, laxity, and load to failure.

FINDINGS

With the implemented elbow simulator no significant difference was observed for gapping or laxity between both treatment groups. Comparing treatment and native ligament, gapping was reduced, especially with increased elbow flexion. Laxity was also reduced at some flexion angles. The mean load-to-failure was 8.1 ± 2.7 Nm without and 9.6 ± 3.6 Nm with internal bracing (P = 0.645).

INTERPRETATION

Both treatments were comparable in biomechanical properties but did not fully restore the native state. Although the additional augmentation of the LUCL reconstruction tends to increase the maximum load to failure, this difference was not statistically significant. Still, reconstruction with internal bracing seems to be a reasonable option in selected primary reconstructions. It could also be useful in revision reconstruction.