Biomechanical evaluation of flexor tendon repair techniques

Immediate active mobilization of repaired tendons is thought to be the most effective way to restore function of injured flexor tendons. Sixty human flexor digitorum profundus tendons were used to evaluate techniques for active tendon motion. The tendons were divided equally into six groups, and each group was assigned to one of the following techniques: Kessler core suture plus running peripheral suture, Kessler plus cross-stitch suture, Kessler plus Halsted suture, Tang core suture plus running peripheral suture, Tang plus cross-stitch suture, or Tang plus Halsted suture. Immediately after tendon repair, an Instron tensile testing machine was used to measure the 2-mm gap formation force, ultimate strength, elastic modulus, and energy to failure of the tendons repaired by these techniques. Ultimate strength, elastic modulus, and energy to failure were measured in load displacement curve. Results showed that the ultimate strength of the Tang plus Halsted or cross-stitch was, respectively, 116.8 +/- 9.6 N and 94.6 +/- 7.8 N; and 2-mm gap formation force was, respectively, 86.6 +/- 4.9 N and 71.9 +/- 5.1 N. The Tang plus Halsted or cross-stitch methods had a statistically significant increase in ultimate strength and 2-mm gap formation force as compared with the Kessler core suture or Tang plus running peripheral suture method. Elastic modulus and energy to failure of the Tang plus Halsted or cross-stitch suture were statistically higher than those of other techniques. The Tang plus cross-stitch or Tang plus Halsted sutures had the highest strength among the tested methods and are appropriate techniques for tendon repair in which the goal is immediate active tendon motion.     

Simplifying four-strand flexor tendon repair using double-stranded suture: a comparative ex vivo study on tensile strength and bulking

We have compared a simple four-strand flexor tendon repair, the single cross-stitch locked repair using a double-stranded suture (dsSCL) against two other four-strand repairs: the Pennington modified Kessler with double-stranded suture (dsPMK); and the cruciate cross-stitch locked repair with single-stranded suture (Modified Sandow). Thirty fresh frozen cadaveric flexor digitorum profundus tendons were transected and repaired with one of the core repair techniques using identical suture material and reinforced with identical peripheral sutures. Bulking at the repair site and tendon-suture junctions was measured. The tendons were subjected to linear load-to-failure testing. Results showed no significant difference in ultimate tensile strength between the Modified Sandow (36.8 N) and dsSCL (32.6 N) whereas the dsPMK was significantly weaker (26.8 N). There were no significant differences in 2 mm gap force, stiffness or bulk between the three repairs. We concluded that the simpler dsSCL repair is comparable to the modified Sandow repair in tensile strength, stiffness and bulking.     

Cyclic testing of pullout sutures and micro-mitek suture anchors in flexor digitorum profundus tendon distal fixation

PURPOSE: Little data exist comparing the strength of traditional methods of fixation in a flexor digitorum profundus tendon with the use of a suture anchor. In vitro cyclic testing simulating a passive mobilization protocol was used to compare the repair of a flexor digitorum profundus tendon using a single micro-Mitek anchor (Mitek, Westwood, MA) or a modified Bunnell 2-strand pullout technique using a monofilament or a braided polyester suture. METHODS: Twenty-four fresh-frozen cadaveric fingers were divided randomly into 4 repair groups (n = 6 each): a micro-Mitek with a 3-0 braided polyester suture or a 3-0 monofilament suture, or a modified Bunnell technique with a 3-0 braided polyester suture or a 3-0 monofilament suture. After repair the specimens were loaded cyclically from 2 to 15 N at 5 N/s, for a total of 500 cycles. Gap formation at the tendon-bone interface was assessed every 100 cycles. Samples were tested to failure at the completion of 500 cycles. RESULTS: No specimens failed catastrophically during cyclic testing. A significantly greater gap formed using the monofilament sutures compared with the braided polyester sutures with both repair techniques. Load to failure in the modified Bunnell technique was superior to the micro-Mitek with both suture types. The modified Bunnell technique using a braided polyester suture was superior to the monofilament suture whereas the suture type did not alter the properties of the micro-Mitek repair. CONCLUSIONS: Significant gap formation with the use of a monofilament suture may be of concern. The use of a braided polyester suture when removal of the pullout suture is required as in the Bunnell technique also needs to be considered.     

The biomechanical assessment of gap formation after flexor tendon repair using partial interlocking cross-stitch peripheral sutures

The gap formation of five core plus peripheral suture techniques for flexor tendon repair was evaluated by cyclic load testing. Fifty pairs of dental roll tendon models were sutured using six-strand Pennington modified Kessler core suture with 4-0 Polypropylene. One-half or three-fourths circumferential interlocking cross-stitch, or three complete circumferential peripheral suture techniques were performed using 6-0 Polypropylene. An initial cyclic load of 10 N for 500 cycles was applied and increased by 5 N for an additional 500 cycles at each new load until rupture. The complete circumferential interlocking cross-stitch had the greatest fatigue strength. The partial circumferential cross-stitches resulted in significantly larger gap formations at both the repaired and unrepaired sides than the complete circumferential sutures, and were also associated with early rupture. The full circumference of the cut tendon must be sutured using an interlocking cross-stitch peripheral suture to improve strength and avoid gap formation.     

A biomechanical analysis of suture materials and their influence on a four-strand flexor tendon repair

PURPOSE: Flexor tendon repair strength depends on the suture technique and the suture material used. Configurations that incorporate locking loops prevent sutures from pulling through the tendon but typically fail because of suture breakage. The choice of suture material therefore influences repair strength. This study investigated the mechanical properties of 5 nonabsorbable 4-0 suture materials (monofilament nylon, monofilament polypropylene, braided polyester, braided stainless steel wire, and braided polyethylene) and evaluated their performance when used in a locking 4-strand flexor tendon repair configuration. METHODS: Five samples of 2 strands of each suture type were tested mechanically to determine the material stiffness and ultimate load. In addition, 50 fresh porcine flexor tendons were divided and repaired with each of the 5 suture materials using a 4-strand single-cross technique. Gap force, ultimate strength, and stiffness were measured to compare biomechanical performance. RESULTS: All repairs failed by suture rupture at the locking loop. Fibrewire and stainless-steel sutures and repairs were significantly stronger and stiffer than the other suture types. The results for Prolene and Ethibond were similar in the tendon repair groups with respect to gap and ultimate forces although Ethibond provided significantly increased repair stiffness. Nylon sutures and repairs consistently produced the poorest mechanical performance in all outcome measures. CONCLUSIONS: Suture material strongly influences the biomechanical performance of multistrand tendon repairs and is an important consideration for the surgeon. Fibrewire and stainless steel are the most biomechanically suitable suture materials for flexor tendon repair whereas nylon is the least suitable. Further developments in suture materials are important for advancements in flexor tendon repair strength.     

A comparative analysis of the biomechanical behaviour of five flexor tendon core sutures

Five core suture techniques were compared by static tensile testing in vitro. Fifty porcine tendons were used. The core sutures were performed with 3-0 or 4-0 braided polyester suture (Ticron) and the over-and-over running peripheral sutures with 6-0 monofilament polypropylene (Prolene). The core sutures were: (1) Pennington modified Kessler (3-0), (2) Double Pennington modified Kessler (3-0), (3) 4-strand Savage (3-0), (4) 4-strand Savage (4-0), and (5) 6-strand Savage (4-0). Repairs were compared as paired in regard to one variable: the number of core suture strands, the suture calibre, or the suture configuration. Biomechanical differences between the repair groups started during the linear region, with the yield force and stiffness increasing along with the number of core suture strands. All three variables influenced the strain at the yield point. Thus, the strength of the intact repair can be improved by modifying the core suture. In all repairs gap formation started near the yield point after failure of the peripheral suture. The yield force represents the strength of the intact repair composite and should be considered the strength of the tendon repair.     

Cyclic stress analysis of flexor tendon repair

A method of evaluating flexor tendon repair techniques with the use of cyclic testing is presented. This type of evaluation complements the presently used load-to-failure tests by providing more detailed information about gap formation at the repair site. During load-to-failure testing in this study, core sutures alone demonstrated initial gap formation at 0.85 kg tensile force or more; yet on cyclic testing all techniques demonstrated gap formation of 1.9 mm or greater at 0.5 kg tensile force. Thus cyclic testing demonstrated gap formation not readily apparent on load-to-failure testing. An epitenon stitch placed circumferentially around the laceration site added strength in both load-to-failure and cyclic tests, and significantly reduced gap formation regardless of the core suture technique.     

Comparative mechanical analysis of a looped-suture tendon repair

The in vitro breaking force of a braided nylon looped-suture tendon juncture designed to decrease tying time was compared with the breaking force of the modified Kessler and Bunnell techniques. Repaired with either braided nylon or tetrafluoroethylene, porcine digiti quarti propius tendons were tested to single cycle failure on a MTS hydraulic testing machine. The results showed that the looped-suture technique had a mean breaking force that was statistically indistinguishable from that of the Bunnell technique regardless of suture material. However, the breaking forces for the looped suture and Bunnell techniques were statistically greater for both suture materials when compared with the modified Kessler technique. The resistance to gap formation for the looped suture was found to be intermediate between the Bunnell technique and the modified Kessler technique.     

Biomechanic comparison of the Teno Fix tendon repair device with the cruciate and modified Kessler techniques

PURPOSE: To compare the mechanical behavior of a novel internal tendon repair device with commonly used 2-strand and 4-strand repair techniques for zone II flexor tendon lacerations. METHODS: Thirty cadaveric flexor digitorum profundus tendons were randomized to 1 of 3 core sutures: (1) cruciate locked 4-strand technique, (2) modified Kessler 2-strand core suture technique, or (3) Teno Fix multifilament wire tendon repair device. Each repair was tested in the load control setting on a Instron controller coupled to an MTS materials testing machine load frame by using an incremental cyclic linear loading protocol. A differential variable reluctance transducer was used to record displacement across the repair site. Cyclic force (n-cycles) to 1-mm gap and repair failure was recorded using serial digital photography. RESULTS: There was no significant difference in differential variable reluctance transducer displacement between the cruciate, modified Kessler, and Teno Fix repairs. The cruciate repair had greater resistance to visual 1-mm repair-site gap formation and repair-site failure when compared with the Kessler and Teno Fix repairs. No significant difference was found between the modified Kessler repair and the Teno Fix repair. In all specimens, the epitenon suture failed before the core suture. Repair failure occurred by suture rupture in the 7 cruciate specimens that failed, with evidence of gap formation before failure. Seven of 10 modified Kessler repairs failed by suture rupture. All of the Teno Fix repairs failed by pullout of the metal anchor. CONCLUSIONS: The Teno Fix repair system did not confer a mechanical advantage over the locked cruciate or modified Kessler suture techniques for zone II lacerations in cadaveric flexor tendons during cyclic loading in a linear testing model. This information may help to define safe boundaries for postoperative rehabilitation when using this internal tendon repair device.     

Bone suture anchors versus the pullout button for repair of distal profundus tendon injuries: a comparison of strength in human cadaveric hands.

Avulsion or distal tendon laceration of flexor digitorum profundus (FDP) is classically repaired to the base of the distal phalanx via a pullout suture over a button. Bone suture anchors, used extensively in other surgical areas, have recently been proposed for reattachment of the FDP to the distal phalanx. The FDP tendons of the index, long, and ring fingers in 9 fresh frozen cadeveric hands were randomized to 1 of 3 repair techniques after simulated distal avulsion injuries. These were the pullout button using 3-0 monofilament nylon in a 2-strand Bunnell suture pattern, the 1.8 mm Mini QuickAnchor (Mitek Products, Norwood, MA) using 3-0 braided polyester in a 2-strand Bunnell suture pattern, and the Mitek micro anchor using 3-0 braided polyester with a modified 4-strand Becker suture pattern. Nine specimens were loaded to failure, noting maximum load and mode of failure. The 1.3 mm Micro QuickAnchor (Mitek) technique (69.6 +/- 10.8 N) was significantly stronger than the pullout button (43.3 +/- 4.8 N) or the Mini anchor technique (44.6 +/- 12.7 N). The Micro bone suture anchor provides a stronger tendon to bone repair than the pullout button or the Mini anchor. Given the disadvantages of the pullout button, the Micro bone suture anchor with the modified Becker technique is worth consideration as an alternative method to repair distal FDP avulsions.     

Effect of core suture technique and type on the gliding resistance during cyclic motion following flexor tendon repair: A cadaveric study

We investigated the effects of two suture techniques using three suture types in a human model in vitro. We obtained 60 flexor digitorum profundus (FDP) tendons from cadavers and measured the gliding resistance during 1,000 cycles of simulated flexion–extension motion and load to failure of six groups: the modified Kessler (MK) repair using 3‐0 coated, braided polyester (Ethibond, Ethicon, Somerville, NJ), 3‐0 coated, braided polyester/monofilament polyethylene composite (FiberWire®; Arthrex, Naples, FL), or 4‐0 FiberWire; and the Massachusetts General Hospital (MGH) repair using 3‐0 Ethibond, 3‐0 FiberWire, or 4‐0 FiberWire. The 3‐0 Ethibond MGH suture had significantly higher ultimate load to failure than the 3‐0 or 4‐0 FiberWire MK suture. The 3‐0 and 4‐0 FiberWire MGH sutures had significantly higher load to failure than the three MK groups. The gliding resistances of the three MGH groups were significantly higher than that of the three corresponding MK groups. The MGH repair had more gliding resistance than an MK repair, even when comparing large diameter suture in the MK repair with smaller diameter suture in the MGH repair. In this study, suture technique was more important in predicting repair load to failure and gliding resistance than the nature or caliber of the suture material that was used. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1475–1481, 2010     

The role of an adhesive (Histoacryl) in tendon repair.

Two in vitro experiments have been done comparing various techniques of tendon repair. These include repairs using an adhesive, 2-butyl cyanoacrylate (Histoacryl), and repairs by the modified Kessler technique, using 4/0 braided polyester and 4/0 stainless steel. Mechanical analysis has shown that by replacing the circumferential suture of a modified Kessler tendon repair with Histoacryl, the tensile strength of the repair and the force needed to produce a gap can be increased by 30% to 40%. This improvement was statistically significant (P < 0.05).     

Biomechanical differences resulting from the combination of suture materials and repair techniques

Background Many suture materials and repair techniques have been applied in clinical tendon surgery. However, no recommendation is available concerning the choice of suture materials and repair techniques except in a few experimental studies. The purpose of the current study is to show the biomechanical difference resulting from the combination of suture materials and repair techniques. Methods The gastrocnemius tendons of 24-week-old cattle (diameter 14–16 × 9–11 mm) were repaired with application of a single locking, multiple locking, single grasping, or multiple grasping technique using a USP2 suture thread of either braided polyblend polyethylene, polyester, polydioxanone, or nylon. Therefore, a total of 16 combinations were made, with eight specimens for each combination. The specimen was set in an Instron tensiometer to measure the gap length after repetitive tensile loading 500 times (10–100 N). Results The single locking technique using braided polyblend polyethylene provided the smallest gap (4.5 ± 0.5 mm). Other techniques using the same material resulted in a large gap (10.0–11.8 mm). The polyester provided a relatively smaller gap length, irrespective of the repair technique (7.4–8.8 mm). Polydioxanone and nylon tended to result in a large gap (9.3–12.3 mm and 8.4–10.6 mm, respectively). Conclusions Mechanical properties of each tendon suture depended on the particular combination of suture materials and repair techniques. The combination of braided polyblend polyethylene and single locking technique provided the highest antigap strength.     

Biomechanical comparison of the simple running and cross-stitch epitenon sutures in achilles tendon repairs

BACKGROUND: Augmenting the strength of Achilles tendon repairs may allow for earlier active rehabilitation with less risk of adhesion formation and re-ruptures, leading to quicker and stronger healing. Building upon previous research that has (1) demonstrated strength gains in Achilles repairs upon addition of simple running epitenon sutures, and (2) shown the cross-stitch epitenon suture to be stronger than the simple running stitch in flexor tendons of the hand, this study compares use of these epitenon sutures in the Achilles tendon. MATERIALS AND METHODS: Ruptures were simulated in 7 matched pairs of fresh frozen human Achilles tendons and repaired with the two-tailed Krakow locking loop core technique using No. 2 nonabsorbable, braided, polyester suture. From each pair, one specimen was randomly selected to also receive the epitenon cross-stitch, the other receiving the simple running stitch. All epitenon repairs employed 4-0 nylon suture. Repaired tendons were loaded in tension to the point of failure on a Materials Testing Machine (MTS). RESULTS: Tendon repair augmented with the cross-stitch displayed a significant, 53% greater failure strength than those repaired with the simple running stitch. Increases in initial stiffness and resistance to 2-mm gap formation in the cross-stitch specimens were 3.1% and 3.6%, respectively. CONCLUSION: Gapping resistance and initial stiffness in Achilles tendon repairs were comparable between the cross-stitch and simple running stitch, but the cross-stitch significantly improved failure strength. CLINICAL RELEVANCE: Greater failure strength may translate clinically to lower rates of re-rupture and earlier mobilization following Achilles tendon repair.     

Cyclic loading of Achilles tendon repairs: a comparison of polyester and polyblend suture

BACKGROUND: Early functional rehabilitation is widely used after open suture repair of the Achilles tendon. To our knowledge, no previous studies have assessed gap formation from cyclic loading and subsequent failure loads of simulated Achilles tendon repairs. A synthetic (polyblend) suture has been introduced for tendon repairs with reportedly greater strength than polyester suture. This stronger, stiffer suture material may provide stronger repairs with less elongation of the tendon repair. METHODS: Simulated Achilles tendon ruptures in bovine Achilles tendon were repaired with a four-strand Krackow suture technique using No. 2 polyester suture. Specimens were loaded for 3,000 cycles at maximal loads of 50, 75, 100, or 125 N, and gap formation at the repair site was continuously measured. After cyclic loading, each specimen was loaded to failure. Identical repairs were performed with number 2 polyblend suture and cyclically loaded to 75 N for 3,000 cycles. All specimens were loaded to failure. RESULTS: Cyclically loading polyester suture repairs to 50, 75, 100, or 125 N for 3,000 cycles resulted in mean gapping at the repair site of 3.0 +/- 0.8, 4.9 +/- 1.0, 7.2 +/- 0.9, and 7.9 +/- 0.8 mm, respectively. Cyclically loading the polyblend suture repairs for 3,000 cycles at 75 N, resulted in 3.3 +/- 0.3 mm of gap formation at the repair site, significantly less than polyester suture repairs (p < 0.001). The mean load to failure for polyester suture repair was 222 +/- 19 N and for polyblend suture repair was 582 +/- 49 N, a statistically significant difference (p < 0.001). Gap formation at 100, 1,000, and 2,000 cycles, as a percentage of total gap formation at 3,000 cycles, was 64.3%, 87.5%, and 95.4% for polyester suture and 45.8%, 78.5%, and 90.1% for polyblend repairs. All specimens in all groups failed at the knots during load-to-failure testing. CONCLUSIONS: Cyclic loading of simulated Achilles tendon repairs using a Krackow, four-core polyester suture technique showed progressive gap formation with increasing load. All repairs failed at the knot, and suture pull-out from tendon was not observed. Polyblend suture repair, when compared to identical repairs with braided polyester suture, resulted in a 260% higher load to failure and 33% less gap formation at the repair site after 3,000 cycles. CLINICAL RELEVANCE: The use of polyblend suture in a four-stranded Krackow configuration provides stronger repairs with less gap formation, which may provide increased security during early functional rehabilitation.     

Biomechanical comparison of the primary stability of suturing Achilles tendon rupture: a cadaver study of Bunnell and Kessler techniques under cyclic loading conditions

Introduction  Biomechanical studies investigating suture techniques for Achilles tendon repair used single load to failure tests in order to evaluate the maximal load capacity of the repaired construct. During early rehabilitation the repair is repetitively loaded such as exercise or daily living activities like walking. Cyclic loading seems to duplicate the physiological loading conditions more closely than single cycle failure tests. Aim of this study was to test the most commonly used Achilles tendon repair techniques (Bunnell and Kessler repair) under cyclic loading conditions. Materials and methods  Following tenotomy fresh human cadaveric tendons were sutured either with the Bunnell or Kessler technique. After repair, cyclic loading tests were performed with a uniaxial biomechanical testing machine Lloyd LR-5K Plus. Both groups were sutured with 0.7 mm PDS. Results  Except at maximum load we could not find significant differences between tendons sutured by Bunnell and Kessler techniques. During the cyclic testing there were no differences between both groups with respect to displacement. This applies also to the stiffness of the constructs, which we defined from the load to failure measurements. The failure modes in both groups differed; the tendons repaired by Kessler technique were cut by the tendons and in the Bunnell group the suture material tore in each specimen tested. Conclusion  In our study Bunnell and Kessler techniques showed similar biomechanical properties using the same suture material. The typical failure mode of the Bunnell technique shows potential to optimise biomechanical behavior by using stronger suture material.     

Biomechanical analysis of knotless flexor tendon repair using large-diameter unidirection barbed suture

Purpose

In traditional flexor tendon repairs, suture knots can be sites of weakness, impair tendon healing, stimulate an inflammatory response, and increase the bulk of the tendon repair. Because of this, there has been an increased interest in knotless flexor tendon repair using barbed suture. Since knots are not required, it may be possible to increase the strength of the tendon repair by using a large-diameter barbed suture. The purpose of this study was to biomechanically compare a traditional four-strand tendon repair using 3-0 braided polyester with a similar knotless four-strand tendon repair using 0 unidirectional barbed suture.

Methods

Twenty-two matched cadaveric flexor digitorum profundus tendons were lacerated and assigned to repair by a four-strand modified Kirchmayr–Kessler technique using 3-0 braided polyester (n = 11) or knotless four-strand modified Kirchmayr–Kessler repair using 0 unidirectional barbed suture (n = 11). Repaired tendons were linearly distracted to failure at 20 mm/min after 1 N preload. Maximum load and load at 2-mm gap formation were recorded. Maximum load and load at 2-mm gap formation were compared with the Student’s t test, and p values ≤ 0.05 were considered significant.

Results

The mean maximum load of the barbed, knotless suture repair was higher than that of the traditional repair (52 vs. 42 N). There was no difference between the two groups in the mean load required to produce a 2-mm gap.

Conclusions

The four-strand knotless tendon repairs using a large-diameter unidirectional barbed suture were stronger than the traditional four-strand repairs using 3-0 braided polyester, and had similar 2-mm gap resistance.     

Mechanical characteristics of cross-stitch epitenon suture in association with various two-strand core sutures: a biomechanical study using canine cadaver tendons

The purpose of this study was to investigate the ultimate tensile strength and stiffness of the cross-stitch epitenon suture technique in association with three different two-strand core suture techniques (the modified Kessler, Tsuge, and two-strand Savage). Twenty-four canine cadaver flexor profundus tendons were lacerated and repaired by one of the following techniques: the cross-stitch (Group 1), the modified Kessler with cross-stitch (Group 2), the Tsuge with cross-stitch (Group 3), and the two-strand Savage with cross-stitch (Group 4). Ultimate strength was determined with a tensile testing machine and stiffness was recorded by a video dimension analyser system. The ultimate strength of Group 2 (5.704 kgf) was significantly greater than that of the other techniques, followed by Group 4 (4.608 kgf), Group 3 (3.568 kgf), and Group 1 (2.935 kgf). The stiffness of Group 2 (495.8 kgf/m) was significantly greater than that of the other techniques, followed by Group 4 (369.7 kgf/m), Group 3 (225.7 kgf/m), and Group 1 (200.1 kgf/m). These results may be helpful to surgeons in deciding which core suture technique to use in association with the cross-stitch epitenon suture.     

An evaluation of suture materials used in tendon surgery

The following suture materials have been evaluated for their suitability for use in flexor tendon repairs: 4/0 gauge monofilament and multifilament stainless steel, mono-filament nylon, monofilament polypropylene, monofilament polybutestor, braided polyester, braided polyglycolic acid and a monofilament polyglyconate. These were investigated for their tensile strength (both knotted and unknotted), their extension to failure and knot-holding properties. Stainless steel and monofilament polyglyconate appeared to be the most suitable in that they had high tensile strengths, both knotted and unknotted, and had good knot-holding security. The only disadvantages are that stainless steel is difficult to use and monofilament polyglyconate is absorbable. Polypropylene and braided polyester, although having lower tensile strengths, are reasonable alternatives.     

Effect of absorbable polydioxanone flexor tendon repair and restricted active mobilization in a canine model.

We performed an experimental study to evaluate the mechanical and histologic healing process of flexor tendon repair using absorbable polydioxanone monofilament followed by active mobilization. Sixty-four canine flexor digitorum profundus tendons were repaired using polydioxanone monofilament or control braided polyester. Animals were evaluated 7, 14, 28, and 42 days after surgery with 12 day 0 control tendons. All repaired tendons healed without rupture or gap formation. Mechanically, all specimens had adequate tensile strength enabling active mobilization. The tendons that were repaired using braided polyester healed without initial tensile depression; however, the ultimate tensile strength values of polydioxanone specimens showed a significant decrease at day 14. Histologically, an inflammatory response was observed around the polydioxanone monofilament; this reaction increased from day 14 to day 42. However, the inflammatory response did not cause large adhesions or large tendon callus formation. This method of using absorbable suture material for tendon repair has the potential for use in the clinical setting.