Flexor Tendon Lacerations Research Articles

Outcomes of Zone II Flexor Tendon Repair Under General Versus Wide Awake Local Anesthesia: A Randomized Controlled Trial

Wide awake local anesthesia no tourniquet (WALANT) is gaining popularity with flexor tendon repair. We hypothesized that results of zone II flexor tendon repair performed under WALANT would be superior to those performed under general anesthesia (GA). A randomized controlled trial was conducted to compare results of repair of zone II flexor tendon lacerations under WALANT versus GA. Following sample size estimation, 86 digits were included and randomized into two groups. All surgeries were performed by a single surgeon using a six-stranded core stitch and running epitenon suture. All patients followed the same early active rehabilitation protocol. The primary outcome was recovery calculated using the Strickland and Glogovac criteria. Secondary outcomes included rupture rate, complication rate, and Disabilities of the Arm, Shoulder, and Hand (DASH) score. All outcomes were reported at the 6-month visit for all patients. Of the 86 digits, three were lost to follow-up. Analysis was performed on 43 digits in the WALANT group and 40 in the GA group. Demographic characteristics including age and sex were comparable in both groups. Rupture of the repair occurred in two digits in each of the WALANT and GA groups. An excellent or good outcome was achieved in 49% and 56% of the digits in the WALANT and GA groups, respectively. This difference was not statistically significant. DASH scores averaged 12.9 and 8.4 for the WALANT and GA groups, respectively. WALANT may not be superior to GA in regards function, rates of rupture, and patient-reported outcomes in repair of zone II flexor tendon lacerations. Surgeons can be confident in choosing either technique if rigorous patient selection, sound surgical technique, and proper hand therapy are employed. Therapeutic I.

Mesenchymal Stromal Cells for the Enhancement of Surgical Flexor Tendon Repair in Animal Models: A Systematic Review and Meta-Analysis.

Flexor tendon lacerations are primarily treated by surgical repair. Limited intrinsic healing ability means the repair site can remain weak. Furthermore, adhesion formation may reduce range of motion post-operatively. Mesenchymal stromal cells (MSCs) have been trialled for repair and regeneration of multiple musculoskeletal structures. Our goal was to determine the efficacy of MSCs in enhancing the biomechanical properties of surgically repaired flexor tendons. A PRISMA systematic review was conducted using four databases (PubMed, Ovid, Web of Science, and CINAHL) to identify studies using MSCs to augment surgical repair of flexor tendon injuries in animals compared to surgical repair alone. Nine studies were included, which investigated either bone marrow- or adipose-derived MSCs. Results of biomechanical testing were extracted and meta-analyses were performed regarding the maximum load, friction and properties relating to viscoelastic behaviour. There was no significant difference in maximum load at final follow-up. However, friction, a surrogate measure of adhesions, was significantly reduced following the application of MSCs (p = 0.04). Other properties showed variable results and dissipation of the therapeutic benefits of MSCs over time. In conclusion, MSCs reduce adhesion formation following tendon injury. This may result from their immunomodulatory function, dampening the inflammatory response. However, this may come at the cost of favourable healing which will restore the tendon's viscoelastic properties. The short duration of some improvements may reflect MSCs' limited survival or poor retention. Further investigation is needed to clarify the effect of MSC therapy and optimise its duration of action.

Cyclic testing of six-strand suture techniques for zone 2 flexor tendon lacerations

BackgroundBiomechanical analysis using cyclic testing for repaired flexor tendons is a clinically relevant method. The aim of this study was to evaluate the tensile properties of two six-strand suture techniques, the triple looped suture and Yoshizu #1 suture techniques using cyclic testing under simulating early active mobilization conditions. MethodsTwenty-five flexor digitorum profundus tendons harvested from fresh frozen human cadaver hands were repaired in zone 2 utilizing one of three repair techniques: the 2-strand modified Kessler (MK) technique as a control, the triple looped suture (TLS) and Yoshizu #1 suture (Y1) techniques. In each suture technique, 4-0 monofilament nylon sutures were used for core sutures and 6-0 monofilament nylon sutures for circumferential running sutures. Cyclic testing was performed using 20 N with 600 cycles at 1 Hz. ResultsFive out of eight specimens in the MK group ruptured during cyclic testing. Thus, this group was excluded from analysis. On the other hand, all tendons in the TLS and Y1 groups tolerated cyclic testing. Average gaps of the TLS and Y1 groups were 0.5 ± 0.8 mm and 1.9 ± 2.2 mm, respectively. All tendons in the TLS group and six out of nine tendons in the Y1 group formed gaps less than 2 mm. Two tendons in the Y1 group formed a gap of 3.8 and 6.6 mm had breakage of peripheral sutures at the first cycle. Mean ultimate tensile force of the TLS and Y1 group measured after cyclic tensing, were 66.2 ± 9.0 N and 65.9 ± 13.1 N, respectively. No statistical difference between the two groups was found in gap and ultimate tensile forces. ConclusionsThis study suggested that the TLS and Y1 techniques have tensile properties to allow early active mobilization. None of tendons repaired with the TLS technique had gaps more than 2 mm.

Flexor Tendon Zone II Repair.

Flexor-tendon injury is a historically challenging problem for orthopaedic surgeons. Much research has been dedicated to finding solutions that offer balance in terms of the strength and ease of the repair versus the rate of complications such as adhesions. The number of core sutures, distance from the tendon edge, and use of an epitendinous stitch have been shown to affect repair strength1-4. A number of configurations have been described for the placement of the suture; however, none has been identified as a clear gold standard5. This article will highlight the preferred tendon repair technique of the senior author (R.J.S.), the Strickland repair with a simple running epitendinous stitch. Relevant anatomy, indications, operative technique, and postoperative management will be discussed. The flexor tendon is typically accessed via extension of the laceration that caused the initial injury. After the neurovascular structures and pulleys are assessed, the tendon is cleaned and prepared for repair. A 3-0 braided nylon suture is utilized for the 4-core strand repair and placed in the Strickland fashion. A 5-0 polypropylene suture is then utilized for the simple running epitendinous stitch. Multiple alternative techniques have been described. These vary in the number of core strands, the repair configuration, the suture caliber, and the use of an epitendinous or other suture. Nonoperative treatment is typically reserved for partial flexor-tendon laceration, as complete tendon discontinuity will not heal and requires surgical intervention. The 4-core strand configuration has been well established to increase the strength of the repair as compared with 2-core strand configurations, while also being easier to accomplish and with less suture burden than other techniques1. The presently described technique has excellent repair strength and can allow for early active range of motion, which is critical to reduce the risk of postoperative adhesions and stiffness. Excellent outcomes have been demonstrated for primary flexor-tendon repair if performed soon after the injury1,2,6,7. Delayed repair may lead to adhesions and poor tendon healing8. Early postoperative rehabilitation is vital for success9. There are advocates for either active or passive protocols10-12. The protocol at our institution is to begin early active place-and-hold therapy at 3 to 5 days postoperatively, which has been shown in the literature to provide improved finger motion as compared with passive-motion therapy13-16.Important Tips:: The proximal end of the tendon may need to be retrieved via a separate incision if it is not accessible through the flexor-tendon sheath.The proximal end of the tendon may be held in place with a 25-gauge needle in order to best place sutures into both ends of the tendon.The epitendinous suture is run around the back wall before the core sutures are tied down, in order to prevent the tendon and repair from bunching up and becoming overly bulky.The entire A4 pulley and the distal A2 pulley can be divided for exposure if necessary.Up to 2 cm of the flexor-tendon sheath can be divided.If there are concomitant digital nerve injuries, repair these after the tendon, in order to avoid damaging the more delicate nerve repair while manipulating the tendon for repair.The most common major complications following tendon repair are formation of adhesions and rerupture. Acronyms and Abbreviations:: FDS = flexor digitorum superficialisFDP = flexor digitorum profundusMCP = metacarpophalangealPIP = proximal interphalangealDIP = distal interphalangeal.

Principles of Tendon Structure, Healing, and the Microenvironment.

Tendon is a strong viscoelastic tissue, responsible for conducting force from muscle to bone. In the hand, flexor tendons course through fibro-osseous sheaths, composed of an intricate tenosynovium and fibrocartilaginous pulley system. After flexor tendon laceration, changes occur in tendon force transduction as well as vascularity, affecting tendon healing on a tissue and cellular level. Tendon healing occurs through intrinsic and extrinsic mechanisms, which in combination with local anatomy, can predispose to adhesion formation. Understanding the relationship between microenvironmental cues and tendon healing on the cellular and tissue level will improve our knowledge and treatment of flexor tendon injuries.

Knotless Tendon Repair with a Resorbable Barbed Suture: An In-vivo Comparison in the Turkey Foot.

Background: Un-knotted barbed suture constructs are postulated to decrease repair bulk and improve tension loading along the entire repair site resulting in beneficial biomechanical repair properties. Applying this repair technique to tendons has shown good results in ex-vivo experiments previously but thus far no in-vivo study could confirm these. Therefore, this current study was conducted to assess the value of un-knotted barbed suture repairs in the primary repair of flexor tendons in an in-vivo setting. Methods: Two groups of 10 turkeys (Meleagris gallapovos) were used. All turkeys underwent surgical zone II flexor tendon laceration repairs. In group one, tendons were repaired using a traditional four-strand cross-locked cruciate (Adelaide) repair, while in group two, a four-strand knotless barbed suture 3D repair was used. Postoperatively repaired digits were casted in functional position, and animals were left free to mobilise and full weight bear, resembling a high-tension post-op rehabilitation protocol. Surgeries and rehabilitations went uneventful and no major complications were noted. The turkeys were monitored for 6 weeks before the repairs were re-examined and assessed against several outcomes, such as failure rate, repair bulk, range of motion, adhesion formation and biomechanical stability. Results: In this high-tension in-vivo tendon repair experiment, traditionally repaired tendons performed significantly better when comparing absolute failure rates and repair stability after 6 weeks. Nevertheless, the knotless barbed suture repairs that remained intact demonstrated benefits in all other outcome measures, including repair bulk, range of motion, adhesion formation and operating time. Conclusions: Previously demonstrated ex-vivo benefits of flexor tendon repairs with resorbable barbed sutures may not be applicable in an in-vivo setting due to significant difference in repair stability and failure rates. Level of Evidence: Level IV (Therapeutic).

Use of a relative motion flexion orthosis after epitendinous zone II flexor tendon repair: A case report

Study designCase report IntroductionRelative motion flexion (RMF) orthoses are emerging as an option for early active motion (EAM) postoperatively. Purpose of the studyTo describe the rationale and implementation of an RMF orthosis to manage a patient after partial zone II epitendinous flexor tendon repairs. MethodsThis case involves a female who sustained partial flexor tendon lacerations to her middle finger in zone II, 60% flexor digitorum superficialis (FDS) and 90% flexor digitorum profundus (FDP). After epitendinous repair she was referred to therapy for EAM with a no orthosis request. The unusual circumstances prompted the therapist, concerned about the risk of tendon rupture to engage in discussion with the surgeon. Following discussion, a decision was made to use an RMF orthosis for controlled EAM to protect the epitendinous zone II FDS and FDP repairs. Outcomes of range of motion (ROM), total active motion (TAM), %TAM, grip, and quickDASH are reported. ResultsNeither the FDP or FDS tendons ruptured, nor were there any joint contractures. “Good” %TAM outcomes were achieved at 12-week postoperatively. Quick DASH scores improved 61 points indicating a clinically meaningful difference of improved function. DiscussionThe lack of a multi-strand core suture repair is unusual in combination with EAM. The positive outcomes reported in this single patient have raised questions about the protective benefit of the RMF orthosis when used with a zone II epitendinous repair of a 90% FDP laceration. Epitendinous repair of a partial (60%) FDS injury, however, is not uncommon and often not repaired at all. ConclusionsIn this single case report the epitendinous repairs of zone II 90% FDP and 60% FDS with digital nerve involvement were successfully managed with an RMF only orthosis. The use of EAM with an epitendinous repair is in conflict to the current surgical and therapy literature.

Practice Patterns in Operative Flexor Tendon Laceration Repair: A 15-Year Analysis of Continuous Certification Data from the American Board of Plastic Surgery.

Background:The American Board of Plastic Surgery has been collecting practice data on operative repair of flexor tendon lacerations since 2006, as part of its Continuous Certification program.Methods:Data on operative repair of flexor tendon lacerations from 2006 to 2014 were reviewed and compared with those from 2015 to 2020. National practice trends observed in these data were evaluated and reviewed alongside published literature and evidence-based medicine.Results:In total, 780 patients with flexor tendon laceration injuries were included. Mean patient age was 38 years; mean time between tendon injury and first evaluation was 4 days, and the mean time from injury to operative repair was 12 days. Four-strand sutures remain the most common technique of tendon repair (57%). In the recent cohort, there were significant decreases in tourniquet use (94% versus 89%), general anesthesia (88% versus 74%), and monofilament sutures (44% versus 35%), with a significant increase reported in preserving the A1 pulley (20% versus 29%). Postoperative movement was described as “almost full range of motion” or “good” in 70% of cases, and 74% of patients were satisfied with their results. Postoperative adverse events were reported in 26% of cases, with the most common complications being tendon adhesions (14%) and rupture (3%).Conclusions:Review of The American Board of Plastic Surgery tracer data for operative repair of flexor tendon lacerations establishes a framework by which surgeons can evaluate how their current practice aligns with that of their peers, and whether their practice patterns remain current relative to recommendations from evidence-based medicine.

A retrospective analysis of controlled active motion (CAM) versus modified Kleinert/Duran (modKD) rehabilitation protocol in flexor tendon repair (zones I and II) in a single center

IntroductionThe aim of this study was to analyze primary flexor tendon repair results in zones I and II, comparing the rupture rate and clinical outcomes of the controlled active motion (CAM) protocol with the modified Kleinert/Duran (mKD) protocol.Materials and methodsPatients who underwent surgery with traumatic flexor tendon lacerations in zones I and II were divided in three groups according to the type of rehabilitation protocol and period of management: group 1 included patients who underwent CAM rehabilitation protocol with six-strand Lim and Tsai suture after May 2014. Group 2 and 3 included patients treated by six-strand Lim Tsai suture followed by a modified Kleinert/Duran (modK/D) protocol with additional place and hold exercises between 2003 and 2005 (group 2) and between 2011 and 2013 (group 3).ResultsRupture rate was 4.7% at 12 weeks in group 1 (3/63 flexor tendon repairs) compared to 2% (1/51 flexor tendon repairs) in group 2 and 8% in group 3 (7/86 flexor tendon repairs). The grip strength at 12 weeks was significantly better in group 2 compared to the group 1 (35 kg/25 kg, p = 0.006). The TAM in group 1 [113° (30–175°)] was significantly worse (p < 0.001) than the TAM in group 2 [141° (90–195°)] but with similar extension deficits in both groups. The assessment of range of motion by the original Strickland classification system resulted in 20% excellent and 15% good outcomes in the CAM group 1 compared with 42% and 36% in the modK/D group 2. Subanalysis demonstrated improvement of good/excellent results according to Strickland from 45% at 3 months to 63.6% after 6-month follow-up in the CAM group.ConclusionThe gut feeling that lead to change in our rehabilitation protocol could be explained by the heterogenous bias. A precise outcome analysis of group 1 could underline that in patients with complex hand trauma, nerve reconstruction, oedema or early extension deficit, an even more intensive and individual rehabilitation has to be performed to achieve better TAM at 6 or 12 weeks. Our study explicitly demonstrated a significant better outcome in the modK/D group compared to CAM group. This monocenter study is limited by its retrospective nature and the low number of patients.

Direct Repair of Flexor Tendons Close to Bony Insertion and Ruptured Collateral Ligaments.

Lacerated flexor tendons close to bony junction are commonly repaired using a pullout suture. However, these injuries very close to the tendon-bone junction can be repaired with robust direct suture repair of the proximal tendon stump with the short residual tendon stump and any local tissues such as periosteum and joint volar plate. Subacute or chronic traumatic rupture at the midpart of the collateral ligaments can also be repaired by "refreshing" the divided ligament ends and repairing the ligament stumps to local tissues with multiple sutures often combined with tightening the elongated joint capsule.

A Biomechanical Comparison of Gliding Resistance between Modified Lim Tsai and Asymmetric Tendon Repair Techniques in Zone II Flexor Tendon Repairs.

Background: Early active motion protocols have shown better functional outcomes in zone II flexor tendon lacerations. Different techniques of tendon repair have different effects on gliding resistance, which can impact tendon excursion and adhesion formation. For successful initiation of early active mobilisation, the repair technique should have high breaking strength and low gliding resistance. Previous studies have shown the Modified Lim-Tsai technique demonstrates these characteristics. The Asymmetric repair has also shown superior ultimate tensile strength. This study aims to compare the gliding resistance between the two techniques. Methods: FDP tendons from ten fresh frozen cadaveric fingers were randomly divided into two groups, transected completely distal to the sheath of the A2 pulley and repaired using either the Modified Lim-Tsai or Asymmetric technique. The core repair was performed with Supramid 4-0 looped sutures and circumferential epitendinous sutures were done with nylon monofilament Prolene 6-0 sutures. The gliding resistance and ultimate tensile strength were then tested. Results: The gliding resistance of the Asymmetric and Modified Lim-Tsai repair techniques were 0.2 and 0.95 N respectively. This difference was significant (p = 0.008). The Modified Lim-Tsai technique had a higher ultimate tensile strength and load to 2 mm gap formation, though this was not significant. Conclusions: Gliding resistance of the Asymmetric repair is significantly less than that of Modified Lim-Tsai. Ultimate tensile strength and load to 2 mm gap formation are comparable.

Techniques for Retrieval of Lacerated Flexor Tendons: A Scoping Review.

Introduction: Flexor tendon laceration is often followed by retraction of the proximal stump. The goals of this review were to describe the myriad of proximal stump retrieval surgical techniques and where available to provide the clinical evidence associated with each. Methods: A Medline and Web of Science search was performed to identify any publication whose primary purpose was to describe a tendon retrieval technique. The techniques were assigned to 8 groups. Clinical outcomes, where reported, and advantages and disadvantages of the technique as reported by the authors of the articles were analyzed. Results: Eight-hundred and forty-one publications complied with the search terms, and 33 articles were included in the current analysis. Only 2 of these articles were randomized controlled trials, and they were of low quality. Conclusion: There is no high-quality evidence to allow quantitative comparison of tendon retrieval techniques. An incremental approach can be recommended based on the qualitative review. After failed atraumatic attempts to retrieve the tendon by milking, retrieval should be done through proximal incision at the A1 pulley level, preferably without pulling the tendon out of the wound. When available, using an endoscope to retrieve the tendon appears to be a promising alternative.

The use of connective tissue growth factor mimics for flexor tendon repair.

Intrasynovial flexor tendon lacerations of the hand are clinically problematic, typically requiring operative repair and extensive rehabilitation. The small-molecule connective tissue growth factor (CTGF) mimics, oxotremorine M (Oxo-M) and 4-PPBP maleate (4-PPBP), have been shown to improve tendon healing in small animal models by stimulating the expansion and differentiation of perivascular CD146+ cells. To enhance intrasynovial flexor tendon healing, small-molecule CTGF mimics were delivered to repaired canine flexor tendons via porous sutures. In vitro studies demonstrated that Oxo-M and 4-PPBP retained their bioactivity and could be released from porous sutures in a sustained manner. However, in vivo delivery of the CTGF mimics did not improve intrasynovial tendon healing. Histologic analyses and expression of tenogenic, extracellular matrix, inflammation, and remodeling genes showed similar outcomes in treated and untreated repairs across two time points. Although in vitro experiments revealed that CTGF mimics stimulated robust responses in extrasynovial tendon cells, there was no response in intrasynovial tendon cells, explaining the lack of in vivo effects. The results of the current study indicate that therapeutic strategies for tendon repair must carefully consider the environment and cellular makeup of the particular tendon for improving the healing response.

Functional Outcomes of Flexor Tendon Repair in the Fingers: A Comparison of Wide-Awake Local Anesthesia No Tourniquet Versus Traditional Anesthesia.

Flexor tendon lacerations in the fingers are challenging injuries that can be repaired using the wide-awake local anesthesia no tourniquet (WALANT) technique or under traditional anesthesia (TA). The purpose of our study was to compare the functional outcomes and complication rates of patients undergoing flexor tendon repair under WALANT versus TA. All patients who underwent a primary flexor tendon repair in zone I and II without tendon graft for closed avulsions or open lacerations between 2015 and 2019 were identified. Electronic medical records were reviewed to record and compare patient demographics, range of motion, functional outcomes, complications, and reoperations. Sixty-five zone I (N = 21) or II (N = 44) flexor tendon repairs were included in the final analysis: 23 WALANT and 42 TA. There were no statistical differences in mean age, length of follow-up, proportion of injured digits, or zone of injury between the groups. The final Quick Disabilities of the Arm, Shoulder, and Hand score in the WALANT group was 17.2 (SD: 14.4) versus 23.3 (SD: 18.5) in the TA group. There were no statistical differences between the groups with any final range of motion (ROM) parameters, grip strength, or Visual Analog Scale pain scores at the final follow-up. The WALANT group was found to have a slightly higher reoperation rate (26.1% vs 7.1%; P = .034) than the TA group. This study represents one of the first clinical studies reporting outcomes of flexor tendon repairs performed under WALANT. Overall, we found no difference in rupture rates, ROM, and functional outcomes following zone I and II flexor tendon repairs when performed under WALANT versus TA.

The Effect of Flexor Digitorum Profundus Repair Position Relative to Camper Chiasm on Tendon Biomechanics

The purpose of this study was to investigate the impact of repairing a zone II flexor digitorum profundus (FDP) laceration anatomically versus extra-anatomically on tendon loads and work of flexion (WOF). Twenty digits from 5 cadaveric specimens were tested using an invitro active finger motion simulator under 2 FDP tendon repair conditions: anatomic and extra-anatomic. Tensile loads in FDP and flexor digitorum superficialis (FDS), WOF, and total active finger range of motion (ROM) were measured using in-line load cells and electromagnetic tracking, respectively. The anatomic repairs had no effect on tendon loads or WOF for either FDP or FDS. The extra-anatomic repairs increased FDP loads by 32% and decreased FDS loads by 9% compared with those in the intact condition. This pattern was similar for WOF following extra-anatomic repairs, which increased FDP WOF by 31% and decreased FDS WOF by 18%. Comparing the 2 repairs, FDP loads and WOF were 25% and 22% greater, respectively, with extra-anatomic repairs compared with anatomic repairs, with no significant change in FDS. Total active ROM was not affected by either repair. In this invitro cadaveric model, extra-anatomic repairs of FDP increased tendon loads and WOF compared with anatomic repairs. On the basis of this study, reconstitution of the anatomic relationship of FDP and FDS at the Camper chiasm during the repair of zone II flexor tendon lacerations is recommended.

Is releasing pulleys during flexor tendon repair "part and parcel"? Narrative review of the current evidence.

The complex hand flexors pulleys system is essential in achieving efficient flexor tendons' function. Previous cadaveric studies demonstrated that A2 and A4 are the crucial pulleys in maintaining normal digits biomechanics. Realistically, the preservation of A2 and A4 pulleys during repairing flexor tendon laceration in zones one and two can be extremely challenging. We review the current published evidence in this article to answer the question of whether releasing the pulleys cause bowstringing or affects clinical outcomes. Literature search of the available databases. There was no published comparative evidence. Retrospective case series have reported that no clinical bowstringing was noted after releasing flexor pulleys during flexor tendon repairs. Outcomes have been reported according to Tang and or Strickland criteria to assess range of motion (ROM). No functional hand scores or patients' satisfactions scores have been reported. Releasing flexor pulleys during tendon repair to allow access or prevent impingement of the repaired tendon does not seem to cause bowstringing or affect outcome based on the limited available evidence. Future research is needed. Level 4.

BIOMECHANICS OF A NEW TECHNIQUE FOR FLEXOR TENDON TENORRAPHY OF THE HAND

Abstract INTRODUCTION The present study compares ultimate tensile strength, gap strength (2, 4, 6 mm), distortion time and breaking time in a new flexor tendon suture, to a conventional technique. MATERIAL AND METHODS The flexor digitorum profundus tendons of 40 porcine forelimbs were repaired. The biomechanical analysis was carried out in a universal testing machine applying a constant speed. Tenotomy gap, the force applied and the rupture point were analysed. RESULTS The ultimate tensile strength, and 4 and 6 mm gap strength were significantly higher with the new technique compared with the conventional 4-strand cruciate technique. CONCLUSIONS The new technique is a higher provider of repair strength during early active mobilization when compared with the conventional 4-strand cruciate technique. These findings suggest that this new suture can be considered a biomechanically favourable technique for the repair of flexor tendon lacerations.

Evaluation of a continuous locking novel epitendinous suture pattern with and without a core locking-loop suture on the biomechanical properties of tenorrhaphy constructs in an ex vivo model of canine superficial digital flexor tendon laceration.

To evaluate the effect of a continuous locking novel epitendinous suture (nES) pattern with and without a core locking-loop (LL) suture on the biomechanical properties of ex vivo canine superficial digital flexor tendon (SDFT) tenorrhaphy constructs. 54 cadaveric forelimb SDFTs from 27 musculoskeletally normal adult dogs. Tendons were assigned to 3 groups (18 SDFTs/group): sharply transected and repaired with a core LL suture alone (group 1), an nES pattern alone (group 2), or a combination of a core LL suture and nES pattern (group 3). All constructs underwent a single load-to-failure test. Yield, peak, and failure loads; gap formation incidence; and mode of failure were compared among the 3 groups. Mean yield, peak, and failure loads differed significantly among the 3 groups and were greatest for group 3 and lowest for group 1. Mean yield, peak, and failure loads for group 3 constructs were greater than those for group 1 constructs by 50%, 47%, and 44%, respectively. None of the group 3 constructs developed 3-mm gaps. The most common mode of failure was suture pulling through the tendon for groups 1 (12/18) and 2 (12/18) and suture breakage for group 3 (13/18). Results suggested augmentation of a core LL suture with an nES pattern significantly increased the strength of and prevented 3-mm gap formation at the tenorrhaphy site in ex vivo canine SDFTs. In vivo studies are necessary to assess the effectiveness and practicality of the nES pattern for SDFT repair in dogs.

A prospective comparative study of pull-out suture technique versus modified Kessler technique in flexor tendon repair for Zone I and distal Zone II injuries

Background: Injuries to the hand are common, and poor functional outcomes can have significant long-term consequences affecting both work and social activities. Good outcomes following flexor tendon lacerations in hand are dependent on a sound surgical repair allowing early active mobilization. Aims and Objectives: The purpose of the study was to compare the clinical and functional outcomes of Zone I and distal Zone II flexor tendon repair using pull-out suture technique with two-strand modified Kessler method. Materials and Methods: This hospital-based prospective study was conducted in a tertiary hospital setup in Manipur for 2 years' duration from November 2018 to November 2020. The study was conducted on 26 patients with a total of 30 injured digits, which were then divided into two equal groups of cases and control. Group A included study cases and were treated with pull-out suture technique. Group B included 15 control cases and were treated with modified Kessler technique. Comparison was done between the two different techniques based on patient variables and outcome measured with total active motion (TAM) evaluation system of the American Society for Surgery of Hands. Statistical Analysis: Data collected were entered into the SPSS version 16. Descriptive analysis of baseline characteristics of both study and control groups was done. The final analysis was done using the Chi-square test and SPSS version 16. P < 0.05 was taken as significant. Results: In our comparative study, at the 3-month follow-up range of motion was measured and TAM was calculated. Among case group, 2 (13%) belonged to good and 13 (87%) belonged to fair category, whereas among control group, 2 (13%) belonged to good and 1 poor category, and 12 (80%) belonged to fair category. About 50%–75% of functional recovery by 3 months was obtained in 80% of the cases and 73% of the control group. Conclusion: The pull-out suture technique is a good option for the management of Zone I and distal Zone II flexor tendon injuries.

Comparison of Magnetic Resonance Imaging and Ultrasound Evaluations of Zone II Partial Flexor Tendon Lacerations: A Cadaveric Study.

Surgical intervention for zone II high-grade partial flexor tendon lacerations is often required when more than half of the tendon width is torn. Reliable noninvasive tests are critical for optimizing clinical decision making. Our team previously investigated the use of ultrasound (US) for identification of high-grade zone II flexor digitorum profundus lacerations. In this study, we compared magnetic resonance imaging (MRI) to US for the evaluation of high-grade partial flexor tendon lacerations in cadaveric specimens. Dissection of 32 digits in 8 fresh-frozen upper extremity cadaveric specimens was performed. The flexor digitorum profundus tendons were randomized into 3 groups: intact, low-grade laceration, and high-grade laceration. A dynamic US examination was performed by a blinded musculoskeletal radiologist. The same specimens underwent hand coil MRI, which was read by the same blinded radiologist. Magnetic resonance imaging test performance metrics were calculated and compared to those computed for the US evaluation. For US evaluation of high-grade lacerations, the sensitivity and specificity were 0.5 and 1.0, with positive likelihood ratio (LR+) and negative likelihood ratio (LR-) values of ∞ and 0.50, respectively. The sensitivity and specificity for MRI evaluation were 0.2 and 1.0, with LR+ and LR- values of ∞ and 0.80. Both US and MRI are adequate at determining the presence of a high-grade laceration. Magnetic resonance imaging was more specific than US in identification of high-grade partial flexor tendon lacerations. Although less specific, US is a reasonable and less-expensive alternative to MRI when evaluating for clinically significant high-grade partial flexor tendon lacerations.