In Vitro Comparison between the Pulvertaft Weave and the Modified Core Suture Pulvertaft Weave

Background: The Pulvertaft weave was described more than 50 years ago and is still used in tendon transfers. The aim of this study was to evaluate the strength of a modified core suture Pulvertaft weave technique and compare it to the original Pulvertaft weave traditionally used in tendon transfer surgery. Methods: 12 extensor pollicis longus tendons and extensor indices proprius tendons were harvested from fresh frozen cadavers. Six Pulvertaft weaves were performed using FiberWire 4.0 and six core suture tendon weave were performed using FiberLoop 4.0. Biomechanical analysis was performed and stifness, first failure load and ultimate failure load were measured for both set of repairs. Results: The stiffness of the core suture tendon repair (9.5 N/mm) was greater than that of the Pulvertaft repair (2.5 N/mm) The first failure load of the core suture tendon repairs (68.9 N) was greater than the Pulvertaft repairs (19.2 N) and the ultimate failure load of the core suture tendon repairs (101.8 N) was greater than the Pulvertaft repairs (21.9 N). All of these differences were statistically significant. Conclusions: The core suture Pulvertaft weave is a modification to the Pulvertaft weave used in tendon transfers. The results of this cadaveric study suggest it is 5 times stronger than the traditional Pulvertaft repair, potentially allowing it to be used with early active motion protocols after tendon transfers.

The use of barbed sutures in the Pulvertaft weave: a biomechanical study

The use of barbed sutures in tendon repair and reconstruction is advantageous because it allows for a knotless suturing technique. In this biomechanical study, we compared barbed sutures with conventional sutures in tendon transfers using the Pulvertaft weave technique in a human cadaveric model. Thirty human cadaveric finger flexor tendons were transected and divided into three groups of ten tendons, which were then reconstructed by the Pulvertaft weave technique using 3-0 Prolene (Ethicon, Inc., Somerville, NJ, USA), 3-0 Ethilon (Ethicon, Inc., Somerville, NJ, USA) or 3-0 V-Loc (Covidien Deutschland GmbH, Neustadt, Germany) sutures. Biomechanical testing showed that repairs in the V-Loc group had significantly greater ultimate tensile strength and stiffness than conventional sutures. The time taken to complete the weave and the length of sutures used were also the least in the V-Loc group. Our study has shown that the barbed suture has a better biomechanical performance than conventional suture types when used in the Pulvertaft weave technique.

Strength of Pulvertaft modifications: tensile testing of porcine flexor tendons

The aim of the study was to present two new modifications of the Pulvertaft weave, allowing a higher number of weaves without the need for a longer overlap. The mechanical properties were measured and compared with the traditional technique. Forty-five pairs of porcine flexor tendons were randomized to a Pulvertaft repair with three weaves, a Double Pulvertaft and Locking Pulvertaft repairs. In the last two repairs one of the tendons in each repair was split in two before weaving. A difference in the maximum stiffness was observed between the three groups (p = 0.024). All repairs failed by the sutures being sheared through the tendons splitting the tendon fibres longitudinally. The two modifications were both stronger than the Pulvertaft weave and provide an alternative when a strong connection is needed and a longer overlap is impossible.

Strength of Interference Screw Fixation to Cuboid vs Pulvertaft Weave to Peroneus Brevis for Tibialis Posterior Tendon Transfer for Foot Drop

BACKGROUND

Tibialis posterior (TP) tendon transfer is an effective treatment for foot drop. Currently, standard practice is to immobilize the ankle in a cast for 6 weeks nonweightbearing, risking postoperative stiffness. To assess whether early active dorsiflexion and protected weightbearing could be safe, the current study assessed tendon displacement under cyclic loading and load to failure, comparing the Pulvertaft weave (PW) to interference screw fixation (ISF) in a cadaveric foot model.

METHODS

Twenty-four cadaveric ankles had TP tendon transfer performed, 12 with the PW technique and 12 with ISF to the cuboid. The TP tendon was cycled 1000 times at 50 to 150 N and then loaded to failure in a materials testing machine. Tendon displacement at the insertion site was recorded every 100 cycles. An independent t test and 2-way analysis of variance were performed to compare techniques, with a significance level of P < .05.

RESULTS

Mean tendon displacement was similar in the PW group (2.9 ± 2.5 mm [mean ± SD]) compared with the ISF group (2.4 ± 1.1 mm), P = .35. One specimen in the ISF group failed early by tendon pullout. None of the PW group failed early, although displacement of 8.9 mm was observed in 1 specimen. Mean load to failure was 419.1 ± 82.6 N in the PW group in comparison to 499.4 ± 109.6 N in the ISF group, P = .06.

CONCLUSION

For TP tendon transfer, ISF and PW techniques were comparable, with no differences in tendon displacement after cyclical loading or load to failure. Greater variability was observed in the PW group, suggesting it may be a less reliable technique.

CLINICAL RELEVANCE

The results indicate that early active dorsiflexion and protected weightbearing may be safe for clinical evaluation, with potential benefits for the patient compared with cast immobilization.

Biomechanical assessment of a novel tendon junction

The Pulvertaft weave has been the standard tendon junction technique used both in tendon transfers and tendon grafts. A limitation of this repair is the sequential failure of stabilizing sutures, rather than the tendon. A novel loop weave is described and compared with the Pulvertaft weave in biomechanical performance. Ovine deep flexor and extensor tendons were used to simulate Pulvertaft or loop weaves (n = 11) for tensile testing. The Pulvertaft weaves failed at the stabilizing sutures, whereas the loop weaves repairs failed by longitudinal splitting of the motor tendon. The loop weave demonstrated significantly higher mean initial failure and ultimate strengths. Tensile loads required to elongate the loop weave by 4, 6, and 8 mm were significantly higher, while more displacement was associated with the Pulvertaft repair under the application of 50, 75, and 100 N tensile loads. This study demonstrates favourable biomechanical characteristics of the new loop weave technique.