Systematic review of tendon transfers in the foot and ankle using interference screw fixation: Outcomes and safety of early versus standard postoperative rehabilitation

Comparison of Staple, Anchor, and Tenodesis Screw for Posterior Tibialis Tendon Fixation: A Biomechanical Analysis

Various posterior tibialis tendon fixation techniques are described in literature. Suture anchor, staple and tenodesis screws are widely used for posterior tibialis tendon transfer, but their stiffness and the maximal ultimate failure load were not tested before. We aimed to compare the initial ultimate failure load and stiffnesses of suture anchor, staple and tenodesis screws on bovine tendon fixation to bovine metaphyseal bone. Thirty-five fresh bovine ankle joints and hooves were obtained from a local abattoir. Metatarsals bones with long extensor tendons were harvested. Staple group had 15, suture anchor group had 10, and tenodesis screw group had 10 samples. All fixations were tested with Instron® ElectroPuls® E10000 Test Instrument. Ultimate failure load and failure location were noted. Staple group's median ultimate failure load was 210.03 N (IQR: 133.43), suture anchor group's was 124.33 N (IQR: 63.67), and tenodesis screw group's was 394.46 N (IQR:115.09). Median stiffness of the staple group was 19.87 N/m (IQR: 15.29); the tenodesis screw group's was 20.28 N/m (IQR: 6.18), the anchor group's was 8.54 N/m (IQR: 4.35). Staples' failure occurred on tendon-staple interface, while suture anchors' occurred on anchor-suture interface and tenodesis screws' occurred on tendon-suture interface. Tenodesis screws' ultimate failure load was the highest (tenodesis vs anchor and staple p < .001 and p = .032, respectively). Staple fixation is less expensive than the other methods and can provide sufficient fixation strength but was weaker than the tenodesis screw fixation. Staples are still a good choice for tendon to bone fixation, whereas the suture anchors provide lower fixation strength at a higher cost.

Methods of Immobilization after Achilles Tendon Rupture Repair: A Comparative Study in Rat Model

OBJECTIVE

The Achilles tendon (AT) is the most frequently ruptured in the human body. Literature describing different immobilization methods' impact on tendon healing after AT repair is lacking. We compare plaster cast, splint, and K-wire to determine which is the most stable and has the fewest complications.

METHODS

Sixty rats aged 5-6 months were selected to establish Achilles tendon injury in two hind legs model. After suturing the ends of the AT together with a modified "Kessler" method (Prolene 5-0). The skin incision was interrupted and sutured with 1-0 thread. Rats were divided into three immobilization methods (plaster cast group, splint group, and K-wire group). In plaster cast group, the hind leg was cast with plaster in the extended position of the hip and knee joints, and the ankle joint was at 150°. Splint and K-wire group used splints and 0.8-mm K-wires, separately. The fixed period was 4 weeks. The incidence of stability and complications (death, necrosis of the legs, necrosis of the skin, and incisional infection) were recorded. Differences were detected using the chi-square test.

RESULTS

Within 4 weeks observation, K-wires showed better stability (90%) compared with the other two ways (40% in plaster cast group, 65% in splint group; p < 0.05). Rats immobilized with K-wires (10%) suffered significantly lower complications compared with plaster cast and splint group (15%; p < 0.05).

CONCLUSION

K-wire has better stability, lower complication rate than other methods. Immobilization with K-wire may be a promising tool in future clinical Achilles tendon rupture applications.

Interference screw versus suture button fixation for tibialis anterior tendon transfer: a biomechanical analysis

Tibialis anterior tendon (TAT) transfer to the lateral cuneiform is commonly utilized to treat dynamic supination for relapsed clubfoot deformity. Traditional suture button fixation (SBF) may lead to skin necrosis at the button/skin interface. While interference screw fixation (ISF) would mitigate this concern, this fixation method has not been investigated in clubfoot patients. This study aims to investigate the performance of ISF versus SBF for TAT transfer in a cadaveric model. Ten matched pairs of cadaveric feet were obtained. One of each matched specimen underwent TAT transfer to the lateral cuneiform using ISF and the other underwent TAT transfer using SBF. For each ISF specimen, the tension of the transferred TAT required to bring the ankle to neutral was measured. This tension was then applied to both matched specimens using an MTS machine. Tension dissipation was measured after a 20-minute interval. In specimens with SBF, a load cell was positioned between the plantar skin and suture button to determine plantar skin pressure at the time of initial tension application. Average tension necessary to achieve neutral dorsiflexion was 49.4 N. Average tension dissipation after 20 min was significantly less in the IFS group (20 N versus 23.6 N, P = 0.02). No fixation failures occurred in either group. Average plantar foot skin pressure was 196.5 mmHg at initial tension application, exceeding thresholds for tissue ischemia. ISF allows for tendon tensioning at forces beyond those expected to result in skin necrosis with SBF with less dissipation of tension over time.

Current strategies for enhancement of the bioactivity of artificial ligaments: A mini-review

Background and objective

Anterior cruciate ligament (ACL) reconstruction calls for artificial ligaments with better bioactivity, however systematic reviews regarding bioactivity enhancement strategies, technologies, and perspectives of artificial ligaments have been rarely found.

Methods

Research papers, reviews, and clinical reports related to artificial ligaments were searched and summarized the current status and research trends of artificial ligaments through a systematic analysis.

Results

Having experienced ups and downs since the very first record of clinical application, artificial ligaments differing in material, and fabrication methods have been reported with different clinical performances. Various manufacturing technologies have developed and realized scaffold- and cell-based strategies. Despite encouraging in-vivo and in-vitro test results, the clinical results of such new designs need further clinical examinations.

Conclusion

As the demand for ACL reconstruction dramatically increases, novel artificial ligaments with better osteoinductivity and mechanical performance are promising.

The translational potential of this article

To develop novel artificial ligaments simultaneously possessing excellent osteoinductivity and satisfactory mechanical performance, it is important to grab a glance at recent research advances. This systematic analysis provides researchers and clinicians with comprehensive and comparable information on artificial ligaments, thus being of clinical translational significance.