Suture-Only Repair Versus Suture Anchor-Augmented Repair for Achilles Tendon Ruptures With a Short Distal Stump: A Biomechanical Comparison

Biomechanical Comparison of Knotless Suture Anchor Versus Percutaneous End-to-End Technique for Mid-Substance Achilles Tendon Rupture Repair

Percutaneous Achilles tendon repairs can be performed with 2 distal fixation techniques: knotless suture anchor repair (KL) or percutaneous end-to-end repair (ETE). There is a paucity of literature comparing the biomechanical strength of these 2 distal fixation techniques. The aim of this study was to compare the strength of KL and ETE repairs using flat-braided suture for mid-substance Achilles tendon rupture during simulated progressive rehabilitation. Nine matched pairs of fresh-frozen below-knee cadaveric extremities were randomly assigned into these 2 repair groups. Each specimen was tested in 2 parts sequentially; Part I simulating passive ankle range of motion (cyclic: 20N-100N), and Part II simulating ambulation in a walking boot (cyclic: 20N-190N). The number of cycles, gap displacement, and the mode of failure were recorded for each repair. Achilles tendon repairs using the percutaneous methods of ETE and KL techniques showed no significant difference in the number of cycles to clinical failure, mean gap displacement, or overall failure rate. During Part I, the survival rate in terms of clinical failure for KL and ETE groups was 8 of 9 repairs and 7 of 9 repairs, respectively. During Part II, all repairs experienced clinical failure in both groups. Five repairs in the KL group experienced suture anchor pull out from the calcaneus, and 3 repairs failed at suture-tendon interface. Four repairs in the ETE group failed due to knot slippage and 5 repairs failed at suture-tendon interface. Both techniques are viable options in treating acute mid-substance Achilles tendon ruptures.

A Critical Biomechanical Evaluation of Foot and Ankle Soft Tissue Repair

The objective of this article is to review the biomechanical stresses that occur during normal physiologic function of lower extremity soft tissue anatomic structures and to use this as a baseline for a critical analysis of the medical literature because it relates to surgical reconstruction following injury. The Achilles tendon, anterior talofibular ligament, plantar plate, and spring ligament are specifically evaluated.

High-Energy Achilles Tendon Rupture With Associated Medial Malleolus Fracture and Traumatic Peroneal Dislocation: A Case Report

Fracture, Achilles tendon rupture, or traumatic dislocation of the peroneal tendons are often seen in isolation after a trauma or sports-related injury. However, in rare circumstances, a combination of these injuries can occur simultaneously. Multiple previous case reports describe a combination of 2 of these injuries. Missed or delayed diagnosis is common in these combination injuries and can lead to significant patient morbidity and result in long-term consequences. We report a case of a 35-year-old man who sustained an Achilles tendon rupture with an associated medial malleolus fracture and traumatic peroneal dislocation after a snowboarding injury. These injuries were treated surgically, and at 9 months postoperatively, the patient had returned to all activities. Clinicians should have a high index of suspicion for concomitant injuries with higher-energy trauma to the ankle and should perform a thorough history, physical examination, and plain radiographs at a minimum.Levels of Evidence: LEVEL 5.

Biomechanical Comparison of Tape Versus Suture in Simulated Achilles Tendon Midsubstance Rupture

As sutures have progressed in strength, increasing evidence supports the suture tendon interface as the site where most tendon repairs fail. We hypothesized that suture tape would have a higher load to failure versus polyblend suture due to its larger surface area. Eleven matched pairs of cadaveric Achilles tendons were sutured with 2 mm wide braided ultrahigh molecular weight polyethylene tape (Tape) or 2 mm wide braided ultrahigh molecular weight polyethylene suture (Suture) using a Krackow repair method. All Achilles repair constructs were cyclically loaded, after which they were loaded to failure. Change in suture footprint height, clinical and ultimate load to failure, and location of failure was recorded. Clinical loads to failure for Tape and Suture were 290.4 ± 74.8 and 231.7 ± 70.4 Newtons, respectively (p= .01). Ultimate loads to failure for Tape and Suture were 352.9 ± 108.1 and 289.8 ± 53.7 Newtons, respectively (p = .11). Cyclic testing resulted in significant changes in footprint height for both Tape and Suture, but the 2 sutures did not differ in terms of the magnitude of change in footprint height (p = .52). The suture tendon interface was the most common site of failure for both Tape and Suture. Our results suggest that Tape may provide added repair strength in vivo for Achilles midsubstance rupture.

Comparison of the double loop knot stitch and Kessler stitch for Achilles tendon repair: A biomechanical cadaver study

Tendon elongation after Achilles tendon (AT) repair is associated with the clinical outcome. Reliable suture techniques are essential to reduce gap formations and to allow early mobilization. Cyclic loading conditions represent the repetitive loading in rehabilitation. The aim of this study was to compare the Kessler stitch and double loop knot stitch (DLKS) in a cyclic loading program focussing on gap formation. Sixteen human cadaveric ATs were transected and sutured using either the Kessler stitch or DLKS (eight matched pairs). The suture-tendon configurations were subjected to cyclic loading and additional ultimate load to failure testing using the Zwick 1446 universal testing machine. Each AT survived cyclic loading, with a mean gap formation less than 5 mm after 1000 cycles. The mechanical properties of the Kessler stitch and DLKS were not significantly different after cyclic loading with a mean displacement of 4.57 mm (± 1.16) for the Kessler stitch and 4.85 mm (± 1.14) for the DLKS (P = .76). There were no significant differences in the ultimate load testing (P = .85). Both bioprotective techniques prevent excessive gaping in cyclic testing when tendon loading is moderate. Our data and those from literature of gap formation in cyclic and ultimate loading allow the conclusion, that early aggressive AT loading after repair (e.g. full weightbearing) overstrain simple as well as complex suture configurations. Initial intraoperative tightening of the knots (preloading) before locking is important to decrease postoperative elongation.

Optimization of the knot configuration for early accelerated rehabilitation after Achilles tendon rupture

Background Panda Rope Bridge Technique (PRBT) was an new minimally invasive technique consisted of two bridge anchors (proximal anchors at calcaneus and distal anchors at myotendinous junction) and strong ropes (threads of the suture anchors) stretched between them, which was suitable for early accelerated rehabilitation of Achilles tendon rupture. However, the optimal knot configuration with PRBT was unknow. The purpose of this study was identify minimum number of half hitches necessary to maintain knot security for PRBT. Methods Using an Instron device we tested the effect of different knot configuration in two kinds of suture threads (Ethibond™ #5 and Ultrabraid™ #2). According to the result of it, we put the optimal knot configuration into Part 1 with PRBT test model and Part 2 with modified PRBT test model, to evaluate whether the optimal knot configuration could complete the cyclic loading test simulated early rehabilitation. Findings In the first part of the study, the optimal knot configuration of Ethibond™ #5 suture thread was the combination of three half hitches and one double throw half knot, and the optimal knot configuration of Ultrabraid™ #2 suture thread was the combination of five half hitches and one double throw half knot. In the second part of the study, only Ultrabraid™ #2 suture thread with optimal knot configuration had finished all test in Part 1. Interpretation The Ultrabraid™ #2 suture thread with optimal knot configuration was suitable for PRBT with early accelerated rehabilitation after Achilles tendon repair.

Minimally Invasive Achilles Repair Techniques

Achilles tendon rupture is an increasingly common problem with an aging population participating in high-level physical activities. Appropriate treatment has been debated for decades, but good outcomes have been reported after conservative and surgical management. The development of minimally invasive surgical techniques for Achilles repair has reduced the incidence of complications and maintained the high level of function reported after open surgery. The Achilles Midsubstance SpeedBridge repair is a newer minimally invasive technique that has demonstrated promising results and is the authors' preferred treatment of Achilles tendon rupture in athletes and active patients.

The elastic capacity of a tendon-repair construct influences the force necessary to induce gapping

PURPOSE

Most biomechanical investigations of tendon repairs were based on output measures from hydraulic loading machines, therefore, accounting for construct failure rather than true gapping within the rupture zone. It was hypothesized that the elastic capacity of a tendon-repair construct influences the force necessary to induce gapping.

METHODS

A tendon-repair model was created in 48 porcine lower hind limbs, which were allocated to three fixation techniques: (1) Krackow, (2) transosseous and (3) anchor fixation. Loading was performed based on a standardized phased load-to-failure protocol using a servohydraulic mechanical testing system MTS (Zwick Roell, Ulm, Germany). Rupture-zone dehiscence was measured with an external motion capture device. Factors influencing dehiscence formation was determined using a linear regression model and adjustment performed as necessary. A 3-mm gap was considered clinically relevant. Analysis of variance (ANOVA) was used for comparison between groups.

RESULTS

The elastic capacity of a tendon-repair construct influences the force necessary to induce gapping of 3 mm (F_3mm) [β = 0.6, confidence interval (CI) 0.4-1.0, p < 0.001]. Furthermore, the three methods of fixation did not differ significantly in terms of maximum force to failure (n.s) or F_3mm (n.s).

CONCLUSION

The main finding of this study demonstrated that the higher the elastic capacity of a tendon-repair construct, the higher the force necessary to induce clinically relevant gapping.

LEVEL OF EVIDENCE

Controlled biomechanical study.