Core Suture Research Articles

Biomechanical Study of Asymmetric Flexor Tendon Repair Using a 6-Strand 4-0 Supramid Suture Versus a 4-Strand 2-0 Tenoflex Suture.

Background: Multi-strand repair of flexor tendons are important for increased strength but this may cause ischemia during the intrinsic healing process. In this study, we aim to compare the strength of the 4-strand modified Asymmetric repair using 2-0 Tenoflex® suture with the original description of the Asymmetric repair using a 6-strand 4-0 Supramid® suture under cyclic loading in a porcine tendon model. We hypothesise that the number of core sutures through the repair site can be reduced with advanced suture material. Methods: Two groups consisting of 10 porcine tendons each were repaired using the Asymmetric repair technique. One group underwent the original description using a 6-strand 4-0 Supramid® suture and the other group underwent a modified 4-strand technique using 2-0 Tenoflex® suture. The repaired tendons were subjected to a two-stage cyclic loading test. Survival rate and gap formation at the repaired site were analysed. The failure mechanism of each repair was also analysed. Additionally, the cross-sectional area of each strand of core suture used was also calculated. Results: The 1st and 2nd stage survival rates were 90% and 30% for the 6-strand repair and 100% and 60% for the 4-strand repair respectively. The mean gap formation at the end of stage 2 was 1.79 mm (SD 1.57) for the 4-strand repair, which is comparable to that of the 6-strand repair (1.82 mm; [SD 1.20]). The total mean cross-sectional area of 2-0 Tenoflex® and 4-0 Supramid® suture strands were 0.078 and 0.086 mm2, respectively. Conclusions: These results demonstrate that despite having fewer core sutures, the 4-strand modified Asymmetric repair using 2-0 Tenoflex® may be a better option as compared to the original 6-strand Asymmetric repair using 4-0 Supramid®.

Effects of a Q Suture Technique as a Core Suture on Resistance to Gap Formation and Tensile Strength in an Ex Vivo Porcine Flexor Tendon Model

The Q suture has been reported to be an effective alternative to conventional peripheral sutures in tendon repair. Whether the Q method can be used as a core suture rather than a peripheral suture by adjusting the purchase length is unknown. We tested a double Q suture technique with variable purchase length and studied its effects on gap formation and tensile strength using an exvivo model. Forty pig flexor tendons were repaired using the double Q sutures with purchase lengths of 2, 4, 6, and 8 mm. Twenty tendons repaired using the double Tsuge and double Kessler sutures with an 8-mm purchase length were used as controls. The tendons were subjected to cyclic loading and load-to-failure. The number of tendons that formed an initial or 2-mm gap between the tendon ends, gap distance at the repair site, stiffness, and ultimate strength were recorded. During cyclic loading, the double Q suture with a 4-8-mm purchase had fewer tendons form an initial or 2-mm gap and a smaller gap size at the repair site than the Tsuge and Kessler sutures. The stiffness of the double Q suture with a 6-8-mm purchase length and Tsuge suture was greater than those of the double Kessler suture. The double Q suture with a 2-mm purchase length had smaller ultimate strength than the other sutures. The Q suture may be an effective tendon repair method whose role can be converted between peripheral and core sutures via adjusting the suture purchase length. With an optimal suture length of 4-6 mm, the double Q method had tensile resistance superior to 4-strand core sutures. The double Q suture may be a viable option as a core suture in flexor tendon repair when the purchase length is appropriately adjusted.

The Effect of an Additional Core Suture During Pulvertaft Tendon Repair: A Fresh-Frozen Cadaver Study

Pulvertaft tendon repair is a strong suture technique; however, proper tendon tension is impaired by repair site elongation. Therefore, methods to reduce postoperative elongation are warranted. This study aimed to determine the effects of additional core sutures during Pulvertaft tendon repair on repair site elongation and rupture strength. A total of 48 finger extensor tendons were harvested from fresh-frozen cadavers, and tendons with similar diameters were paired. The 24 pairs of tendons were divided into the following 4 groups: group I, 3 interlaced weaves only; group II, 3 interlaced weaves and 2 core suture strands with 4-0 nylon; group III, 3 interlaced weaves and 2 core suture strands with 4-0 FiberWire; and group IV, 4 interlaced weaves only. Each sutured tendon was placed in a Universal Testing Machine, and repair site elongation after repeated traction loads and rupture strength were measured. The mean elongation values were 2.74 ± 0.84 mm, 1.80 ± 0.16 mm, 1.60 ± 0.18 mm, and 1.92 ± 0.18 mm for groups I, II, III, and IV, respectively. The elongation values were significantly lower in groups II, III, and IV than in group I. The mean rupture strengths were 64.9 ± 16.0 N, 94.8 ± 17.2 N, 110.9 ± 21.3 N, and 104.9 ± 17.5 N for groups I, II, III, and IV, respectively. Rupture strengths were significantly higher for groups III and IV than for group I. After adding core sutures during Pulvertaft tendon repair, the elongation amount decreased, and the rupture strength improved. The study showed the effect of additional core sutures during Pulvertaft tendon repair, suggesting that it could be useful in reducing postoperative tendon elongation when extensor tendon transfers are performed.

Biomechanical Evaluation of a Novel Double-Strand (Looped) Polyamide Monofilament Suture for Canine Flexor Tendon Repair

Objective: Determine the influence of a novel looped polyamide suture on the biomechanical properties and gap formation of repaired canine flexor tendons. Study Design: Tendons were assigned to 3 groups (n=12/group). Following transection, tendons were repaired with a Kessler pattern using monofilament polypropylene, Kessler pattern using looped polyamide suture and a Kessler pattern using looped polyamide augmented with a continuous Epitendinous Suture (ES) representing groups 1, 2, and 3 respectively. Constructs were tested to simulate clinical failure. Yield, peak and failure loads, loads at -1 and 3mm gap formation and failure modes were analyzed. Results: Looped polyamide suture is equivalent to monofilament polypropylene using a Kessler core pattern. Looped polyamide suture augmented with a running ES significantly increased yield, peak and failure loads by 3.2x, 3.0x and 2.6x respectively, compared to core suture use alone. Use of an ES required significantly greater force to cause 3mm gap formation while reducing occurrence of gapping in tested constructs. Mode of failure differed among experimental constructs. Conclusion: Looped polyamide suture is equivalent to monofilament polypropylene in the same pattern. Our results support the addition of ES augmentation, a simple technique modification that demonstrates substantially improved repair strength while reducing the occurrence of gapping between tendon ends. Future in-vivo studies investigating effect of suture placement on tendinous healing, blood supply, and glide function are warranted.

Loop modification of the traditional three-loop pulley pattern improves the biomechanical properties and resistance to 3-mm gap formation in a canine common calcanean teno-osseous avulsion model.

To compare the biomechanical properties and gapping characteristics following loop modification of a 3-loop-pulley (3LP) pattern in an ex vivo canine common calcaneal tendon (CCT) avulsion repair model. 56 skeletally mature hindlimbs from 28 canine cadavers. The CCTs were randomized to 1 of 4 experimental groups (n = 14/group) then sharply transected at the teno-osseous junction. Groups consisted of a 3LP, 4-loop-pulley (4LP), 5-loop-pulley (5LP), or 6-loop-pulley (6LP) pattern with loops placed 60° apart using size-0 polypropylene. Yield, peak, and failure loads, construct stiffness, loads to produce a 3-mm teno-osseous gap, and failure mode were evaluated and compared between groups. Yield (P = 0.001), peak (P < 0.001), and failure loads (P < 0.001), construct stiffness (P < 0.001), and loads to 3-mm gap formation (P = 0.005) were all significantly greater for 6LP compared to all other groups. Mode of failure did not differ among groups (P = 0.733) with 75% (42/56) of repairs failing by mechanism of core sutures pulling through the tendinous tissue. Pattern modification by increasing the number of loops increased the repair site strength by 1.4, 1.6, and 1.8 times for 4LP, 5LP, and 6LP compared to 3LP, respectively. Increasing the number of suture loops compared to a traditional 3LP repair is a relatively simple technique modification that significantly increases teno-osseous repair site strength and loads required to cause 3-mm gap formation. The results of this study justify further focused investigation of increasing the number of suture loops in vivo for teno-osseous CCT repair in dogs.

A Survey of Zone II Flexor Tendon Repair Techniques and Rehabilitation Protocols Preferred by Malaysian Orthopaedic Practitioners.

Introduction:Flexor tendon repair is challenging mainly due to the need to balance between a strong repair technique, ease of tendon gliding and early mobilisation to prevent adhesions while preventing tendon rupture. While different countries have different preferences in repair techniques, core sutures and suture types, there is still no study in Malaysia regarding our preference and whether we are following the current evidence.Materials and methods:We performed a survey with a standard questionnaire distributed during our annual national orthopaedic meeting in 2019. The standard questionnaire consisted of 24-objective multiple-choice questions concerning the treatment of flexor tendon injury were distributed with consent. A total of 290 questionnaires that were filled out correctly were included in this study.Results:The majority of respondents preferred the Modified Kessler technique (n=96, 33.1%) followed by the Adelaide technique (n=81, 27.9%) and Double Modified Kessler (n=45, 15.5%). However, for the number of core strands in the repair, the majority utilised the 4-strand (n=203, 70%), followed by 2-strand (n=34, 11.7%) and 6-strand (n=21, 7.2%). The majority utilised Prolene sutures (n=259, 89.3%) with a suture size of 4/0 (n=157, 54.1%). For rehabilitation, 56.9% (n=165) preferred early passive motion, 27.6% (n=80) early active motion and 14.8% (n=43) would strictly immobilise.Conclusion:There is still no consensus as to the best technique; however, the aim of tendon repairs is still the same around the world. It would be helpful to know our preferences to improve our current practice and outcomes following these common flexor tendon injuries in hand.

Comparison of 4 Different 4-Strand Core Suturing Techniques for Flexor Tendon Laceration: An Ex Vivo Biomechanical Study.

Forces applied to the repaired flexor tendon should not exceed its yield force during early postoperative rehabilitation to prevent gapping and rupture. We aimed to biomechanically compare the tensile strengths and the 2-mm gapping of 4 different 4-strand core suturing techniques for flexor tendon repair. Fifty-six goat deep digital flexor tendons were repaired with the 4-strand double-modified Kessler, the 4-strand augmented Becker, the 4-strand Savage, and the 4-strand modified Tang techniques. All tendons were repaired with 4-0 polyester for core suture and 5-0 polyester for continuous epitendinous running suture. The specimens were subjected to static linear tensile testing by applying a single linear load-to-failure pull. After the linear load testing, the yield load, the ultimate strength of the repaired tendons, and the force exerted to yield a 2-mm gap were measured. All peripheral sutures ruptured near the yield point. All core suture techniques were similar regarding the yield force. The augmented Becker 4-strand technique had the greatest ultimate strength (98.7 [82-125.3] N). The modified double Kessler technique was the weakest in resisting a 2-mm gap formation. The 4-strand modified Tang repair had the shortest (11.3 [7-15] minutes), while the 4-strand augmented Becker had the longest operative time (29 [23-33] minutes). All 4 techniques demonstrated similar yield force, with differences in operative time, ultimate strength, and resistance to gapping. Future clinical studies can further elucidate their appropriateness for early active motion protocols.

Outcome of Surgical Repair and Rehabilitation of Flexor Tendon Injuries in Zone II of the Hand: Systematic Review and Meta-Analysis

We performed a systematic review and meta-analysis to determine an optimal rehabilitation protocol following surgical repair for flexor tendon injury in zone II of the hand. Records from PubMed, Embase, and Cochrane were retrieved from their establishment to January 12, 2020. Seven studies were included in the final analysis. A total of 569 digits with a flexor tendon injury in zone II of the hand were included in this meta-analysis: 135 in a place and hold group; 161 in an active flexion and extension group; and 273 in an early passive motion group. There was no significant difference between the place and hold and early passive motion regimes in the incidence of rupture. There was a significant difference between the active flexion and extension and early passive motion regimes in the incidence of rupture. In the early active motion group, the possibility of 1 or more grades of improvement on the Strickland grading system was increased. The early active motion group obtained greater total active motion than the early passive motion group. A higher risk of rupture was noted in the active flexion and extension subgroup repaired by 2-strand core suture. The 2-strand technique was not sufficient for active flexion and extension protocols. Further study in multistrand tendon repair technique with early active exercise in zone II should be undertaken to determine its efficacy. Therapeutic IV.

Flexor tendon repair: recent changes and current methods.

The current clinical methods of flexor tendon repair are remarkably different from those used 20 years ago. This article starts with a review of the current methods, followed by presentation of past experience and current status of six eminent hand surgery units from four continents/regions. Many units are using, or are moving toward using, the recent strong (multi-strand) core suture method together with a simpler peripheral suture. Venting of the critical pulleys over less than 2 cm length is safe and favours functional recovery. These repair and recent motion protocols lead to remarkably more reliable repairs, with over 80% good or excellent outcomes achieved rather consistently after Zone 2 repair along with infrequent need of tenolysis. Despite slight variations in repair methods, they all consider general principles and should be followed. Outcomes of Zone 2 repairs are not dissimilar to those in other zones with very low to zero incidence of rupture.

Rupture Rate, Functional Outcome and Patient Satisfaction after Primary Flexor Tendon Repair with the Modified 4-Strand Core Suture Technique by Tsuge and Using the Arthrex FiberLoop® with Early Motion Rehabilitation.

Purpose:Our hypothesis was that the rupture rate after primary flexor tendon repair in the modified 4-strand core suture technique using the FiberLoop® (Arthrex, Munich, Germany) is lower than in other suture materials and functional outcome and patient satisfaction are superior compared to the current literature. Patients and methods: A 2-stage retrospective, randomized follow-up study of 143 patients treated with the Arthrex FiberLoop® after flexor tendon injury in zones 2 or 3 from May 2013 to May 2017 was performed. In the 1st stage, the rupture rate of all patients was assessed after a follow-up of at least one year by interview to exclude revision surgery. In the 2nd stage, 20% of the patients could be randomly clinically examined. Functional parameters, such as finger and wrist range of motion measured by goniometer, grip strength measured by Jamar dynamometer (Saehan, South Korea), patient satisfaction measured by school grades (1–6), pain levels measured by visual rating scales (0–10) and functional outcome according to the DASH-score were assessed. The Buck-Gramcko and Strickland scores were calculated. The length of sick leave was recorded. Results: A rupture rate of 2.1% was recorded. 29 patients (20%) were followed up at a mean of 34 ± 7.5 months postoperatively. 10.3% of these patients had an incomplete fingertip palm distance. The mean postoperative grip strength was 24 ± 3.1 kg. 93% of the patients were very satisfied with the treatment. No patient complained of pain postoperatively. The mean postoperative DASH score was 6.7 ± 2.8 points. The mean Buck-Gramcko score was 14 ± 0.2 points. 93% of the patients had excellent and 7% good results according to the Strickland score. 67% of patients had a work accident and returned to work at a mean of 4 ± 0.2 months postoperatively. 31% of patients suffered a non-occupational injury and returned to work at a mean of 3 ± 0.4 months postoperatively. Conclusions: Primary flexor tendon repair in the modified 4-strand core suture technique using the Arthrex FiberLoop® has proven to be a viable treatment option in our series. The rupture rate was lower than in other suture materials. It leads to acceptable pain relief, grip strength and functional outcome. Level of Evidence: IV; therapeutic.

Evaluation of biomechanical properties on partial and complete epitendinous suture in human cadaver flexor tendon repair

ObjectiveThis study was designed to compare the ultimate tensile strength and force to 2 mm gap formation among 50% partial, 75% partial, and complete circumferential epitendinous suture with a combination of 4-strand core suture in human cadaver flexor tendon.Materials and methodsForty-five flexor tendons from four soft human cadavers were used to evaluate the biomechanical property among 50% partial, 75% partial, and complete circumferential epitendinous suture with a combination of 4-strand core suture.ResultsThe force to 2 mm gap of complete epitendinous was significantly greater than partial epitendinous suture (P < 0.05); however, there was no difference between 50% partial and 75% partial epitendinous suture (P > 0.05). For the ultimate strength, there was no significant difference between partial and complete epitendinous suture (P > 0.05). The partial epitendinous was approximately 60% of the complete epitendinous suture in force to 2 mm gap and also 70% of complete epitendinous suture in ultimate tensile strength with a combination of core sutures.ConclusionsThe complete epitendinous suture showed better ultimate tensile strength and force to 2 mm gap compared with a partial 50% and 75% epitendinous suture. However, in some clinical scenario which the complete epitendinous suture is not possible to perform, the authors suggested only partial epitendinous suture with 50% circumference is recommended as the additional epitendinous repair up 75% circumference cannot provide any mechanical benefit to the repaired site.

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.

Up to five-week delay in primary repair of Zone 2 flexor tendon injuries: outcomes and complications.

We report the outcomes of delayed primary repair of flexor tendons in Zone 2 in 31 fingers and thumb (28 patients) averaging 15days (range 4-37) after injury in 2020. The delay was longer than usual due to the COVID-19 pandemic. The tendons were repaired with a 6-strand core suture (M-Tang method) or a double Tsuge suture and a peripheral suture. This was followed by an early, partial-range, active flexion exercise programme. Adhesions in four digits required tenolysis. These patients were not with longest delay. Outcomes of two improved after tenolysis. The other two patients declined further surgery. One finger flexor tendon ruptured in early active motion. This was re-repaired, and final outcome was good. Overall excellent and good results using the Tang criteria were in 27 out of 31 fingers and thumbs (87%). The time elapsed between the injury and surgery is not an important risk factor for a good outcome, rather it depends on proper surgical methods, the surgeon's experience and early mobilization, properly applied. Adhesions may occur, but they can be managed with tenolysis.Level of evidence: IV.

The impact of transverse components on 4-strand tendon repairs.

We investigated the effects of the transverse components of a tendon core suture on tensile resistance and strength of 4-strand repairs. Forty-four pig flexor tendons were repaired with one of the following four methods: double Tsuge, U-shaped, 4-strand cross and 4-strand rectangular repairs. We recorded the number of the repaired tendons that formed a 2 mm gap between the tendon ends during cyclic loading for 20 cycles, stiffness of the tendon at the 1st and 20th cycle, gap distance at the repair site and ultimate strength of the repair at the 20th cycle. When transverse components were added to the core suture, a greater number of tendons formed a 2 mm gap during cyclic loading. The stiffness gradually decreased, and the repair site's gap distance after cyclic loading increased with the presence of transverse components of the sutures. We conclude that the core suture's transverse components negatively impact the tensile resistance of 4-strand tendon repairs.

The impact of transverse components on resistance and ultimate strength of 6-strand tendon repairs.

We assessed the effects of tendon core sutures' transverse components on the tensile resistance of two commonly used 6-strand tendon repairs. Tang and Yoshizu #1 repairs (6-strand) were tested and compared with 4-strand rectangular and double Kessler sutures (4-strand). A total of 40 pig flexor tendons were tested under cyclic loading. We recorded the number of tendons that formed a 2-mm gap between two tendon ends during 20 cycles of cyclic loading test, stiffness at the 1st and 20th loading cycle, and gap distance at the repair site and the ultimate repair strength at the 20th cycles. We found that the Yoshizu #1 repairs were more prone to form gaps and their ultimate strength was significantly lower than that of the Tang repair. The transverse components in a 6-strand repair affect gap formation and failure strength.

Biomechanical evaluation of a novel barbed suture pattern with epitendinous suture augmentation in a canine flexor tendon model.

To determine the effect of a novel barbed suture pattern (NBSP) compared to a three-loop-pulley (3LP) with and without epitendinous suture (ES) augmentation on the biomechanical strength and gap formation of repaired canine tendons. Ex vivo, cadaveric, randomized, experimental study. Forty, adult superficial digital flexor tendons (SDFT). SDFT were randomly assigned to one of four groups (n=10/group). Sharp tenotomy was performed and repaired with 3LP, NBSP, 3LP + ES, and NBSP + ES. Constructs were tested to failure while evaluating yield, peak, and failure loads, loads at 1 and 3 mm gap formation, and failure mode. Constructs augmented with ES sustained 80% greater yield (p < .001), peak (p < .001), and failure (p < .001) loads, with no difference between 3LP + ES and NBSP + ES constructs regarding peak (p=.614), and failure forces (p=.865). Loads resulting in 1 and 3 mm gap formation were greater when constructs were augmented with an ES (p ≤ .003). Failure mode differed between groups (p < .001), occurring predominantly due to suture pull-through in 3LP and NBSP groups compared to tissue failure distant to the repair site in ES augmented constructs. Tendons repaired with the NBSP used in this study resisted similar forces as those repaired with 3LP. Augmentation with an ES improved the biomechanical properties of repaired constructs, including resistance to gap formation. The NBSP repair tested here may be advantageous over monofilament suture repair as it uses a similar-sized barbed core suture but eliminates the requirement for knot tying.

Polytetrafluoroethylene (PTFE) suture vs fiberwire and polypropylene in flexor tendon repair

BackgroundIn this study, we evaluate the value of novel suture material based on monofilamentous-extruded polyfluoroethylene (PTFE) compared to polypropylene (PPL) and Fiberwire (FW).Materials and methods60 flexor tendons were harvested from fresh cadaveric upper extremities. 4–0 sutures strands were used in the PPL, FW and PTFE group. Knotting properties and mechanical characteristics of the suture materials were evaluated. A 4-strand locked cruciate (Adelaide) or a 6-strand (M-Tang) suture technique was applied as core sutures for a tendon repair. Two-way ANOVA tests were performed with the Bonferroni correction.ResultsStable knotting was achieved with 5 throws with the PPL material, 7 throws for FW and 9 throws for PTFE. In the PPL group, linear tensile strength was 45.92 ± 12.53 N, in the FW group 80.11 ± 18.34 N and in the PTFE group 76.16 ± 29.10 N. FW and PTFE are significantly stronger than PPL but show no significant difference among each other. Similar results were obtained in the subgroup comparisons for different repair techniques. The Adelaide and the M-Tang knotting technique showed no significant difference.ConclusionFiberwire showed superior handling and knotting properties in comparison to PTFE. However, PTFE allows easier approximation of the stumps. In both, M-Tang and Adelaide repairs, PTFE was equal to FW in terms of repair strength. Both PTFE and FW provide for a robust tendon repair so that early active motion regimens for rehabilitation can be applied.

Transosseous Sutures in Tendon-to-Bone Repairs: the Role of the Epitendinous Suture

Background: Numerous transosseous fixation techniques for flexor tendon injuries in Zone 1 of the hand have been described in the literature. While relatively high maximal loads to failure are documented in different biomechanical experiments, several tests revealed a low 2 mm gapping resistance of the tendon-to-bone repairs. We therefore aimed to investigate the effect on gap formation adding a peripheral suture to an established transosseous fixation technique. In addition, we analyzed the influence of different suture materials (braided vs. non-braided) on the stability of the core suture. Method: A total of 30 porcine flexor digitorum profundus tendons were divided into 3 groups (n = 10 each) and repaired using the transverse intraosseous loop technique (TILT). In group 1 and group 2 the repairs were performed using PDS 3-0 or Ethibond 3-0, respectively. In group 3, a peripheral suture was added to the core suture (PDS 3-0) consisting of two figure-of-eight stitches with PDS 5-0. The biomechanical performance of the repaired tendons was analyzed using a standardized protocol. Results: The suture material and peripheral suture showed no effect on the ultimate failure load in our testing. However, the addition of a peripheral suture led to a statistically significantly higher 2 mm gap force when compared with the repair with a core suture only. Conclusion: In conclusion, addition of a palmar epitendinous suture to the transosseous core suture significantly increases the load to 2 mm gap formation in Zone 1 flexor tendon repairs and thus allows an immediate controlled mobilization.

Management of Flexor Pollicis Longus Injury - Experience in BSMMU

Anatomic consideration: Flexor pollicis longus (FPL) tendon arises from volar aspect of middle third of radial shaft and from the lateral aspect of interosseous membrane. The anterior interosseous branch of median nerve innervates the muscle in the proximal/mid forearm. Blood supply is predominantly from radial artery.&#x0D; Abstract Purpose: The purpose of this study was to evaluate the results of repair and one stage reconstruction of FPL injury and to find out complications and rupture rate and effectiveness of repair and reconstruction.&#x0D; Method: This retrospective review was carried out in Bangabandhu Sheikh Mujib Medical University from January 2015 to December 2018. 30 consecutive patients were enrolled in the study. 4 strands core suture with simple circumferential suture were used for repair and reconstruction. Tendon transfer was done in few cases. Power grip, active and passive range of motion, American Society for Surgery of the Hand criteria and Buck-Gramcko criteria were used for outcome assessment.&#x0D; Results: Out of 30 patients, 20 (67%) were male and 10 (33%) were female. Mean age was 30 years. Mean follow up period was 1.5 years. All cases were due to various type of cut injuries. In subjective assessment 40% patients achieved excellent, 50% good, 10% fair results. Our rupture rate was 0%. Mean power grip, pinch grip strength of index and key pinch strength were 87.5%, 68.18% and 86.66% respectively from contralateral normal hand. Active range of motion of IP joint was 64.28% of normal side.&#x0D; Conclusions: Use of 4 strands core sutures and early active motion give good to excellent results in 90% cases of repair, reconstruction and tendon transfer in FPL injuries with 0% rupture rate&#x0D; J Shaheed Suhrawardy Med Coll, December 2020, Vol.12(1); 20-26

Effect of Oblique Tendon Laceration on Core Suture Strength: A Biomechanical Evaluation.

The effect of obliquity of tendon laceration on repair strength is not well studied. The overwhelming majority of biomechanical studies assess repair strength following a laceration that is perpendicular to the long axis of the tendon. The aim of this study was to investigate whether the angle of tendon laceration affects the core suture strength. In all, 110 fresh human cadaveric flexor tendons were cut at varying angles of 15°, 30°, 45°, and 60° and the control group at 90°. All tendons were repaired with 6-strand modified Tang technique. The repair strength was tested using a custom-made tensioning machine, and the initial static gap force and the ultimate breaking force were measured. The mean gap force and 95% confidence interval (CI) for the 15°, 30°, 45°, 60°, and 90° groups were 15.2 N (11.4-19.0 N), 15.8 N (13.6-18.1 N), 15.6 N (13.1-18.4 N), 16.6 N (13.7-19.5 N), and 22.3 N (16.6-27.9 N), respectively. In the same respective order, the break force and 95% CI were 25.9 N (21.9-29.8 N), 26.5 N (23.2-29.7 N), 31.1 N (26.1-36.1 N), 35.6 N (28.2-43.1 N), and 51.8 N (62.5-41.0), respectively. The Fisher least significant difference demonstrated significant differences between the control group and all experimental groups for both gap force and break force. Obliquity of tendon laceration affects the core suture strength when compared with a transverse cut. Flexor tendons cut at 90° demonstrated a higher overall gap force and breaking strength that were statistically significant when compared with all obliquely cut groups. These findings should be considered when repairing and starting postoperative therapy for obliquely cut tendons.