Proximal and Distal Failure Site Analysis in Percutaneous Achilles Tendon Rupture Repair

Abstract

Background: Different techniques have been described for percutaneous Achilles tendon rupture repair, but no biomechanical evaluation has been performed separately for proximal and distal suturing techniques. The purpose of this study was to biomechanically analyze proximal versus distal percutaneous Achilles suture configurations during cyclic loading and load to failure. Methods: A simulated, midsubstance rupture was created 6 cm proximal to the calcaneal insertion in fresh-frozen cadaveric Achilles tendons. Fifteen proximal specimens were divided into 3 groups: (A1) triple locking technique, (A2) Bunnell-type technique, and (A3) double Bunnell-type technique. Twelve distal specimens were divided into 2 groups: (B1) triple nonlocking technique and (B2) oblique technique. Repairs were subjected to cyclic testing and load to failure. Load to failure, cause of failure, and tendon elongation were evaluated. Results: None of the proximal specimens and 7/12 of the distal ones failed in cyclic testing. The proximal fixation groups demonstrated significantly more strength than the distal groups ( P = .001), achieving up to 710 N of failure load in Group A3. Groups B1and B2 failed on average at 380 N with no difference between them ( P > .05). The majority of all repairs failed in the suture-tendon interface. Distal groups had more elongation during cyclic testing (13.7 mm) than proximal groups (9.4 mm) ( P = .02). Conclusion: The distal fixation site in this Achilles tendon repair was significantly weaker than the proximal fixation site. A proximal modified suture configuration increased resistance to cyclic loading and load to failure significantly. Clinical Relevance: A modification can be suggested to improve strength of the Achilles repair.

The modified mini-open technique for repairing total ruptured Achilles tendon using fiber wire with calcaneal fixation. A prospective case series

“…Hockenbury found percutaneous repair of Achilles tendon ruptures provided approximately 50% of the initial strength afforded by open repair [ 25 ]. Wagner [ 33 ] reported that the distal fixation site in this Achilles tendon repair with a triple nonlocking technique was significantly weaker than the proximal fixation site with a triple locking technique, a Bunnell-type technique, or a double Bunnell-type technique, the constructs tested were not strong enough to confidently allow weight-bearing in a walker boot. Patel [ 13 ] and Wagner [ 34 ] placed the proximal sutures into the calcaneus with a Push Lock anchor system to overcome this disadvantage.…”

“…Some authors didn't meet re-rupture [ [30] , [31] , [32] ]. Clanton [ 36 ] and Wagner [ 33 ] found that percutaneous techniques elongated the Achilles tendon 10 mm. Wagner [ 33 ] recommended pre-tensioning the repair.…”

Long Term Follow-up of Composite Flaps for Single-stage Reconstruction of Concomitant Tendon and Soft Tissue Defects

“…For example, the Achilles tendon needs to sustain a minimum of 190 N over repeated load cycles and glide 4 cm during the normal gait cycle. 8 , 17 , 22 Unfortunately, combined tendon and soft tissue injuries ultimately yield some degree of impairment, even with current methods of composite flap single-stage reconstruction. There can be wide variations in torque loss, ranging from 6.0% to 80.0% differences between injured and uninjured limbs, in patients undergoing composite flap reconstruction.…”

Influence of Achilles tendon rupture site on surgical repair outcomes

“…Biomechanical features are not consistent among different sections of the Achilles tendon and may contribute to results of the common rupture site. 16 Different biomechanical strengths may be related to various arrangement patterns of type I and type III collagens. Ruptured Achilles tendons have more type III collagens than healthy Achilles tendons, and this pathological feature is evident in regions adjacent to the rupture site.…”