Strong Digital Flexor Tendon Repair, Extension-Flexion Test, and Early Active Flexion: Experience in 300 Tendons

The value of local dexmedetomidine as an adjuvant to ultrasound-guided wide awake local anesthesia no tourniquet (WALANT) in flexor tendon repair surgeries: a randomized controlled trial

BACKGROUND

The Wide-Awake Local Anesthesia No Tourniquet (WALANT) technique allows intraoperative motor assessment of tendon repair integrity of the hand compared with general anesthesia or brachial plexus block. No studies have tested the effect of adding dexmedetomidine to lidocaine on the analgesic properties of the WALANT technique, which is the aim of our study.

METHODS

A total of 128 patients aged more than 18 years were scheduled for surgical flexor tendon injury repair using WALANT technique. Patients were divided into two equal groups. Ultrasound-guided subcutaneous injection of lidocaine 1% with dexmedetomidine (1 µg/kg), Group D, or without dexmedetomidine, Group C, was performed at four points: proximal to the wrist joint, the distal forearm, palm region, and proximal phalanges. The primary outcome was total morphine consumption throughout the first postoperative day. Secondary outcomes included number of patients requiring rescue analgesia, time to first analgesic request, and pain score.

RESULTS

Total morphine consumption was significantly (P < 0.001) lower in group D (2.66 ± 0.998) than in group C (3.66 ± 1.144) mg. Number of patients requiring rescue analgesia was significantly (P < 0.001) lower in group D (54.7% (35)) than group C (100.0% (64)). The time for first request for analgesia was significantly (P < 0.001) longer in group D (11.31 ± 6.944) than in group C (5.91 ± 4.839) h. Pain score was significantly higher in group C than D at three (P < 0.001), and six (P = 0.001) hours (P = 0.001) postoperatively.

CONCLUSION

Dexmedetomidine significantly improves the analgesic quality of WALANT when added to lidocaine with less opioid consumption.

TRIAL REGISTRATION

(ID: PACTR202203906027106; Date: 31/07/2023).

Complications of flexor tendon repair

This article reviews and highlights complications of flexor tendon repairs. Although the outcomes of flexor tendon repairs have improved over the years, fair or poor functional outcomes are seen, especially in patients whose trauma involves multiple structures of the hand and in zone 5 with multiple tendon lacerations. Rupture of the flexor tendon after repair is no longer a major problem if current repair principles are carefully adhered to. Different degrees of adhesion formations and interphalangeal (IP) joint stiffness still occur in a few patients. Early active postoperative mobilization and use of a shorter splint with sparing of the wrist are effective measures to prevent adhesion formation and IP joint stiffness. Given the overall poor results and high rate of complications with flexor digitorum profundus (FDP) repairs in zone 1, a direct repair of the FDP tendon to any short remnant of the distal insertion with 10-strand or even stronger core suture repair is adopted by many units.

Minimally Invasive Suture Technique Pull-out to Repair the Acute Flexor Tendons in Zone II of the Hand

Objective:  To evaluate the safety and effectiveness of a modified pull-out suture technique in patients undergoing primary repair surgery for injuries to the flexor tendons of the fingers with Total Active Motion (TAM) as the primary outcome. Method:  A total of 29 patients (38 fingers) were chosen from both sexes, aged between 18 and 65 years with clean acute tendon laceration occurring within 15 days, in the Verdan's zone II of flexor tendon in the hand, when only the deep flexor tendon was sutured, either associated or not with digital nerve injury. The patients were operated on using the proposed technique and evaluated at 3, 9 and 24-weeks PO. The primary outcome was the assessment of Total Active Movement (TAM) and 3 classifications were employed: Strickland, IFSSH and Buck-Gramcko. Results:  We observed a total active motion (TAM) of 209.3 °at the end of 24 weeks; 83.0% of Good and Excellent results by the Modified Strickland Classification, 93% of Excellent results by the IFSSH Classification, and 97% of Good and Excellent results using the Buck-Gramcko Classification. There were no cases of rupture, but tendon adhesion was observed in 3 fingers. Conclusion:  The present suture technique proved to be safe and effective with a low rate of complications, obtaining an excellent functional result in terms of total active mobility, according to the evaluations and classifications used.

Healing strength of tendon repair with or without knots between two tendon ends and histological changes in a chicken model

We studied the healing strength and histological changes of digital flexor tendons repaired using Kessler (core suture knots placed over the tendon surface) and modified Kessler (core suture knots placed between two tendon ends) in 31 long toes of chicken. Four weeks after surgery, the healing tendons were measured in a tensile testing machine, and the adhesion formation and histological changes were observed. The strength of the Kessler repairs was significantly greater than that of the modified Kessler repairs with a 35% mean difference. No significant difference was found between the adhesion scores of the tendons repaired with both techniques. In histological sections, the arrangement of collagen fibers in the modified Kessler repair group was more disordered. We conclude that the tendons repaired with the Kessler method are stronger than those with the modified Kessler technique. The knots between tendon ends are detrimental to the early healing strength of digital flexor tendons.

Comparison of Clinical Outcomes of Endoscope-Assisted Technique and Conventional Surgery in Zone 2 Flexor Tendon Repair

PURPOSE

The purpose of the study was to compare clinical outcomes between patients who underwent endoscope-assisted flexor tendon repair and those who underwent conventional surgery.

METHODS

Patients were divided into 2 groups. Group 1 (endoscope-assisted surgery) included 21 patients (27 fingers) and group 2 (conventional surgery) included 19 patients (25 fingers). Outcomes assessed included the mean total active motion, Strickland classification, prevalence of rerupture, tenolysis requirement, and infection rate.

RESULTS

The mean total active motion was 152.3° in group 1 and 134.7° in group 2, which was significantly higher in group 1 compared to group 2. An excellent or good outcome was achieved in 25 (92.5%) of the fingers in group 1 as opposed to 17 (68%) fingers in group 2.

CONCLUSIONS

We conclude that endoscope-assisted surgery is an alternative method for tendon surgery, enables a minimally invasive approach, and provides a favorable range of motion.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Outcomes of 218 primary single-finger flexor tendon repairs up to 1 year after surgery: a multicentre cohort study

In this retrospective multicentre cohort study, we present the results of primary single-finger flexor tendon repairs in zones 1 to 3 between 2014 and 2021. Data from 218 patients were retrieved with their demographics, injury and surgery characteristics and therapy outcomes. The data were systematically collected and analysed at predefined time points up to 1 year after surgery. A good to excellent return of motion was achieved by 77% (Tang classification) and 92% (American Association for Surgery of the Hand classification) of patients at 1 year. The tendon rupture rate was 8.7%. Time had a significant impact on the recovery of finger motion and grip strength of up to 1 year, of patient satisfaction and upper extremity function up to 26 weeks, and of pain up to 13 weeks after surgery. Our results demonstrate that it is worthwhile to assess therapy outcomes over various measurement periods, as some outcomes may continue to improve up to 1 year after flexor tendon repair surgery.Level of evidence: III.

Safety and efficacy of ultrasonography of tension after zone II flexor tendon repair: A randomized controlled trial

BACKGROUND

Primary flexor tendon repairs of lacerations in zone II of the hand are fraught with problems. Traditionally, exercise (active and passive), orthoses, and physical agents are common interventions for the rehabilitation of patients experiencing these issues. One area of focus in this field is how to safely utilize tension to lengthen gliding distance following zone II injury. Finding effective solutions in this area is a key priority for improving patient outcomes and quality of life.

PURPOSE

To identify the optimal immobilization position that meets safety standards for tension and is the most efficient, and consequently, to validate our clinical effectiveness.

STUDY DESIGN

A cross-sectional study was adopted for the first part of the research (Research 1). A prospective, parallel, 2-group, randomized trial was conducted with concealed allocation and single blinding in the second part of the research (Research 2).

METHODS

A total of 60 healthy adults were recruited to select the best-fit protective immobilization position in Research 1, which was confirmed by tendon tension (via Young's modulus) and excursion (via gliding distance). We then randomly assigned 45 patients after zone II flexor tendon repair into two groups in Research 2 to compare functional outcomes. The control group underwent the conventional modified Duran protocol with early passive motion, while the experimental group received the protocol (optimized by Research 1) with early active motion. Ultrasonography was used to measure the tension and excursion of the flexor tendons. The outcomes measured at 16 weeks post-repair included total active motion, strength, the Disabilities of the Arm, Shoulder and Hand, and Strickland scores.

RESULTS

Three participants were unable to participate in Research 2 due to medical issues and poor attendance. The investigation found that the safe tendon threshold was 345.09 ± 87.74 kPa for partial active digital motion among the 60 participants. The optimal immobilization position requires the wrist to be neutral with a flexion angle of 30° at the metacarpophalangeal joint. The grip strengths (p = 0.012), ratio of grip strength (p = 0.015), the Disabilities of the Arm, Shoulder and Hand (p = 0.036), and total active motion (p = 0.023) differed significantly between the two groups.

CONCLUSIONS

Protective immobilization of the wrist in a neutral flexion position and with the metacarpophalangeal joint flexed at 30° can secure the repaired flexor tendon safely and efficiently. The effects of an early active motion ‎protocol may improve the grip strength and upper limb mobility of individuals after zone II flexor tendon repair.

CLINICAL TRIAL REGISTRATION

ChiCTR2000030592.

Effect of loading speed on gap resistance and tensile strength of flexor tendon repair under cyclic loading test

Postoperative digit motion is important for the functional recovery of injured tendons. To date, it is unknown whether the loading speed impacts the biomechanical properties of a repaired tendon. This study investigated the effect of loading speed on the gap resistance and tensile strength of tendon repairs. One hundred porcine flexor tendons were repaired with two core sutures, 4-strand modified Kessler and double Q, and cyclically loaded at the speeds of 10, 40, 80, 160, and 320 mm/min. The number of tendons that formed an initial or 2 mm gap at the repair site during cyclic loading, stiffness at the 1st and 20th loading cycles, gap size between tendon ends when cyclic loading ended, and the ultimate strength were recorded. Under the lowest loading speed, the tendons repaired with the 4-strand modified Kessler suture developed significantly larger gaps and smaller stiffness than those with a greater loading speed. The loading speed did not affect the maximum strength of both tendon repairs. The findings suggest that very slow motion promotes gap formation of tendon repair with inferior gap resistance. The rate corresponds to regular hand action or the tendon core suture possessing a strong gap resistance increases the safety margin during early active finger movement. Our findings help to guide the exercise regimens after tendon surgery.

Tips to Successful Flexor Tendon Repair and Reconstruction with WALANT

WALANT has generated many changes that have improved flexor tendon repair and reconstruction in the last 10 years. Seeing awake unsedated educable patients move repaired reconstructed tendons during the surgery has changed how we do surgery and therapy in many ways for the better. This article offers many tips on how to get better results in using these new techniques with the help of WALANT.

Treatment of Pyogenic Flexor Tenosynovitis in the Emergency Department Setting With WALANT Technique

BACKGROUND

The standard of care for treatment of pyogenic flexor tenosynovitis (PFT) involves antibiotic therapy and prompt irrigation of the flexor tendon sheath, traditionally performed in the operating room. With the acceptance of wide-awake local anesthesia no tourniquet (WALANT) hand surgery and its potential ability to minimize time to flexor tendon sheath irrigation, we sought to determine whether closed irrigation of the flexor tendon sheath could be safely and effectively performed in the emergency department setting with WALANT technique.

METHODS

A retrospective review was conducted of the senior author's hand surgery consultations over a 12-month period. Six patients were identified who were diagnosed with PFT and subsequently underwent irrigation of the flexor tendon sheath using WALANT technique. Patient outcomes such as length of hospital stay, need for reoperation, infectious etiology, perioperative complications, and postprocedure range of motion (ROM) were identified.

RESULTS

Six patients with diagnosis of PFT underwent irrigation of the flexor tendon sheath in the emergency department with local anesthesia only. The irrigation procedures were all well-tolerated. One patient required reoperation due to lack of appropriate clinical improvement following initial irrigation. Four of 6 patients regained their preinjury ROM while the remaining 2 patients had mild proximal interphalangeal joint extension lag. There were no complications associated with the procedures.

CONCLUSIONS

Surgical treatment of PFT with closed irrigation of the flexor tendon sheath in the emergency department utilizing WALANT technique was safe, effective, and well-tolerated. Local anesthesia alone can be used effectively for irrigation procedures of the flexor tendon sheath.

Tenolysis and Salvage Procedures

Complications in flexor tendon repair are common and include tendon rupture, adhesion formation, and joint contracture. Risk factors include preexisting conditions, gross contamination, concurrent fracture, early unplanned loading of the repaired tendon, premature cessation of splinting, and aggressive early active range of motion protocols with insufficient repair strength. Rupture of a repaired tendon should be followed by early operative exploration, debridement, and revision with a four-core strand suture and nonbraided epitendinous suture. Wide-awake flexor tenolysis should be considered when adhesion formation results in the plateaued range of motion, and passive motion exceeds active motion. Two-staged reconstruction is recommended when injury results in excessive scaring, joint contracture, or an incompetent pulley apparatus.

Flexor Tendon Repair Techniques: M-Tang Repair

The authors present the methods and outcomes from six institutes where M-Tang repairs with early active flexion exercise are used for zone 2 digital flexor tendon repair. The authors had close to zero repair ruptures, and few digits needed tenolysis. The excellent to good results are generally between 80% and 90%. In the pandemic period, less stringent therapy supervision might have allowed some patients to move too aggressively, with repair ruptures not seen before the pandemic in one institute. In Nantong, Yixing, and Saint John, the rupture incidence is zero to 1%. In Florence and Heidelberg, the rupture incidence was 3%.

Comparison of the Outcomes of Flexor Tendon Repair in Zone II Using the Original and Adjusted Strickland Scores and the 400-Points Hand Test

Background: The purpose of this study was to report the outcomes of flexor tendon repair in zone II and compare two analytic tests - the original and adjusted Strickland scores - and a global hand function test, the 400-points test. Methods: We included 31 consecutive patients (35 fingers) with a mean age of 36 years (range 19-82 years) who underwent surgery for a flexor tendon repair in zone II. All patients were treated in the same healthcare facility by the same surgical team. All the patients were followed and evaluated by the same team of hand therapists. Results: At 3 months after the surgery, we found a good outcome in 26% of patients with the original Strickland score, 66% with the adjusted one and 62% with the 400-points test. Among the 35 fingers, 13 of them were evaluated at 6 months after the surgery. All the scores had improved with 31% good outcomes in the original Strickland score, 77% in the adjusted Strickland score and 87% in the 400-points test. The results were significantly different between the original and adjusted Strickland scores. Good agreement was found between the adjusted Strickland score and the 400-points test. Conclusions: Our results suggest that flexor tendon repair in zone II remains difficult to assess based solely on an analytic test. It should be combined with an objective global hand function test, such as the 400-points test, which appears to correlate with the adjusted Strickland score. Level of Evidence: Level IV (Therapeutic).

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

PURPOSE

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).

METHODS

Twenty digits from 5 cadaveric specimens were tested using an in vitro 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.

RESULTS

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.

CONCLUSIONS

In this in vitro cadaveric model, extra-anatomic repairs of FDP increased tendon loads and WOF compared with anatomic repairs.

CLINICAL RELEVANCE

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.

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

INTRODUCTION

The 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 METHODS

Patients 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).

RESULTS

Rupture 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.

CONCLUSION

The 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.

Biomechanical Analysis of a New Eight-Strand Suture for Flexor Tendon Repair

Background The placement of multistrand sutures during flexor tendon repair requires complicated surgical skills; such suturing is difficult. We developed a new, simpler eight-strand suture, which we term the Yoshizu cross-lock. This reduces the numbers of suture passages through the tendons, as well as the numbers of knots.

Methods Fourteen porcine flexor tendons were transected and repaired using the Yoshizu cross-lock system; no peripheral sutures were placed. Our system is a modification of the published, exposed cross-lock repair method that employs a 4–0 monofilament nylon two-strand line and two needles. The repaired tendons were subjected to linear, noncyclic load-to-failure tensile testing. The initial gap, the 2-mm gap force, and the ultimate strength were measured.

Results The initial gap force was 12.6 ± 5.6 Newtons (N), the 2-mm gap force was 33.9 ± 10.9 N, and the ultimate strength was 70.1 ± 17.0 N. All tendons subjected to Yoshizu cross-lock repair failed due to suture rupture rather than pullout.

Conclusions Our biomechanical study revealed that Yoshizu cross-lock repair had sufficient tensile strength but was associated with wide variation in the 2-mm gap load (standard deviation = 10.9 N). This study is clinically relevant, showing that the Yoshizu cross-lock repair combined with peripheral suturing may allow a repaired flexor tendon to withstand the stresses encountered during early active mobilization. This simple eight-strand technique will be particularly useful to surgeons who commonly employ the cross-lock stitch for primary flexor tendon repair following early mobilization.

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.

Flexor digitorum profundus tendon injuries in Zone 2 repaired with a modified Mantero technique

From January 2010 to January 2017, 81 complete flexor digitorum profundus tendon disruptions in Zones 2B and 2C were treated using the modified Mantero technique. The patients were re-examined at a mean of 62 months (range 30-96) after operation. We analysed outcomes against ages, gender, pulley integrity, associated injuries and follow-up times. The median total range of motion of both interphalangeal joints, distal interphalangeal joint alone and Quick DASH scores were significantly better for the group with pulley vented versus no pulley vented. According to the Strickland and Glogovac criteria, 76 (91%) had excellent or good, five fair and none had poor results. There were no complications except for one deep and one superficial infection at the site of the injury. There were no tendon ruptures and only three patients (3.7%) required secondary tenolysis. The modified Mantero repair is recommended as an alternative in the repair of tendon disruptions in Zone 2B and 2C. The good results and absence of ruptures suggest that the tendon healing and strength of repair are adequate for immediate postoperative motion.Level of evidence: IV.

Investigations into flexor tendon repair: a research journey over three decades

In this article, I review how my team and I addressed clinical concerns in Zone 2 flexor tendon repair, and how major findings in each step of our research were translated into clinical practice. The focus of the article is on the thought processes behind each new investigation, the interpretation of research findings and conclusions drawn from the basic and clinical studies.

A study to compare strengths of cadaveric tendon repairs with round-bodied and cutting needles

This human cadaver study investigated whether flexor tendon repairs performed with round-bodied needles had a higher risk of pull-out compared with those performed with cutting needles. Forty human cadaver tendons were repaired (20 with each type of needle), subjected to tensile traction testing and evaluated by failure load and mode of failure. The average failure load was 50 N (SD 13 N) for tendons repaired with round-bodied needles, compared with 49 N (SD 16 N) for tendons repaired with cutting needles. Round-bodied needles resulted in more suture pull-out (18 out of 20 tendons) than cutting needles (6 out of 20 tendons). We found no differences in failure load, but significant differences in the mode of failure between round-bodied and cutting needles when used for cadaveric flexor tendon repair.

Outcomes of Wide-Awake Flexor Tendon Repairs in 58 Fingers and 9 Thumbs

PURPOSE

The purpose of this study was to present the outcomes of wide-awake flexor tendon repairs in zones 1 and 2 in a major hand trauma referral center.

METHODS

Zone 1 and zone 2 wide-awake flexor tendon repairs performed between August 2018 and March 2020 were analyzed retrospectively. Outcomes were assessed by the original Strickland-Glogovac criteria for fingers and Buck-Gramcko scoring system for thumbs. Further descriptive analysis of the groups according to potential negative factors, such as injury mechanism, concomitant neurovascular injury, and the extent of injury in zone 2, were performed.

RESULTS

A total of 94 tendons were repaired in 67 digits (58 fingers, 9 thumbs) of the 61 patients included in the study. Satisfactory results were achieved in 89.6% of the fingers and 77.8% of the thumbs. Intraoperative gapping was corrected after active digital extension-flexion test in 1 patient. Rupture was seen in 1 patient for a rate of 1.5%. The tenolysis indication rate was 5.1% for fingers and 11.1% for thumbs.

CONCLUSIONS

In our series, functional outcome scores, tenolysis, and rupture rates remained similar with findings in the literature. The outcome of a flexor tendon repair is influenced by many factors that cannot be controlled intraoperatively. To assess the effect of performing the repair in a wide-awake setting on the outcome, clinical trials with large patient groups are needed.

LEVEL OF EVIDENCE

Therapeutic IV.

Secondary Procedures following Flexor Tendon Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the indications and management options for secondary flexor tendon reconstruction, including tenolysis, tendon grafting, and tendon transfers. 2. Understand the reconstructive options for pulley reconstruction. 3. Understand the options for management of isolated flexor digitorum profundus injuries.

SUMMARY

Despite current advances in flexor tendon repair, complications can still occur following surgery. This article presents the spectrum of treatment options for secondary flexor tendon reconstruction ranging from tenolysis to one- and two-stage tendon grafting, and tendon transfers. In addition, an overview of pulley reconstruction and the treatment of isolated flexor digitorum profundus injuries are discussed. A management algorithm for secondary flexor tendon reconstruction is provided.

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.

The Impact of Dividing the Flexor Tendon Pulleys on Tendon Excursion and Work of Flexion in a Cadaveric Model

PURPOSE

The A2 and A4 pulleys of the flexor tendon system have traditionally been considered critical components of efficient digital flexion. This dogma has recently been challenged. Using fresh human cadaveric hands and a model to measure force and excursion, we sought to clarify the clinical importance of releasing different pulleys.

METHODS

Combinations of A1, A2, and A4 pulleys were released on the index, middle, ring, and little fingers of fresh, cadaveric hands. The excursion was measured as the distance the tendon was pulled by the motor to achieve palm touchdown. The force applied by the motor was constant (25 N); work was derived from the product of force and excursion (distance). The change in excursion and work needed to achieve palm touchdown before and after pulley release was measured. Excursion varies among digits and specimens at baseline; therefore, the percentage change from the intact state was used to compare groups. We compared A2 versus A1, A4 versus A1, A4 versus A2, A1 + A2 versus A2, and A1 + A4 versus A4.

RESULTS

Isolated A2 or A4 release had the greatest individual impact on the excursion (4.77% ± 1.52% and 3.88% ± 1.93%, respectively). When A1 was released with A2 (9.90% ± 2.52%), the additional impact on the excursion was significant; however, when A1 was released with A4 (2.63% ± 2.81%), the impact was marginal. No clinically or statistically significant change in the work of flexion was detected.

CONCLUSIONS

A1 release was clinically significant when added to A2 release but not when added to A4 release. Sacrifice of the A2 and A4 pulleys resulted in a statistically significant, but clinically negligible, difference in flexor tendon excursion. These data suggest that the A1 pulley should be preserved when other proximal pulley components are likely to be compromised. These data also add further support to the concept that the A2 pulley or the A4 pulley can be released as needed for optimal tenorrhaphy.

CLINICAL RELEVANCE

During flexor tendon repair, the length of contiguous pulley release may have more impact on final tendon excursion than which specific pulleys are released.

Systemic Immunosuppression for Prevention of Recurrent Tendon Adhesions

Background:

The recovery for patients after tendon repair is frequently limited by development of tendon adhesions. This scar tissue formation is dependent on immune system activation. Tacrolimus has unique properties that may contribute to the prevention of overactive scarring by inhibition of inflammatory cytokines.

Methods:

Herein, we present a case using systemic immunosuppression to prevent recurrent adhesion accumulation in a patient with a prior spaghetti wrist injury. Tacrolimus began 1 week before repeat-secondary tenolysis surgery, and it continued for 3 months postoperative. Dosing was tapered to a serum level between 5 and 8 µg/L.

Results:

The 27-year-old male patient suffered a volar wrist laceration transecting all flexor tendons and volar wrist nerves. He underwent immediate repair but had a poor outcome despite early range of motion therapy. A primary tenolysis only improved his average arc of finger motion from 72 to 95 degrees. Secondary tenolysis augmented with systemic tacrolimus improved his arc of finger motion from 95 to 202 degrees. Mechanistically, tacrolimus prevents proper function of activated T and B cells. This results in decreased proliferation, angiogenesis, and cytoskeletal organization of fibroblasts on inflammation and integrin adhesions, and it potentially explains the reduced tendon molecule adhesions seen in this patient.

Conclusions:

Tacrolimus may be effective in reducing motion, limiting tendon adhesions. The novel use of this medication resulted in the return of near-normal hand function in a patient placed on low-dose tacrolimus after primary tenolysis had failed.

Post-operative management of flexor tendon injuries at zone II and flexor pollicis longus – a survey of Irish practice

Purpose

The post-operative management of flexor tendon injuries has been the focus of considerable exploration and there continues to be variation in approaches and methods of mobilisation. The purpose of this paper is to explore therapy management following repair to flexor tendons at zone II and flexor pollicis longus (FPL) (all zones) in Ireland.

Design/methodology/approach

A descriptive survey questionnaire design through an online format was used. Therapists were recruited through the Irish Association of Hand Therapists, the national bodies for occupational therapy and physiotherapy, and therapy managers in acute hospitals, with 29 therapists participating in the study. Descriptive statistics were used to analyse the survey data.

Findings

Patients were generally seen three to five days following surgery. Early active mobilisation approaches were favoured by all but one therapist, with 62% using the Belfast protocol and 34% the Manchester Short Splint (MSS) protocol. Each early active protocol exercise session commences with passive motion followed by graded active flexion. Tenodesis is incorporated by the majority of respondents within the first four weeks. Therapy programme and splints are modified based on patient presentation. Resistance exercises are commenced from week seven. Patient compliance was identified as the most influential factor in the post-operative intervention approach taken.

Originality/value

This study provides the first Irish profile of current practice in the post-operative management of flexor tendon repairs at zone II and FPL which has not previously been reported. Further research should explore the reasoning behind the interventions chosen and also the implications for practice of changes to surgical techniques.

Rehabilitation after flexor tendon repair and others: a safe and efficient protocol

In this review I detail the protocol that I use after flexor tendon repair and outline my experience regarding how its framework might be used for other disorders. The early passive-active flexion protocol has a sufficient number of cycles of active flexion in each exercise session, which is at least 40, and ideally 60 to 80. The frequency of exercise sessions may range from 4 to 6 a day, distributed in the morning, afternoon and evening. Increasing the number of daily sessions without a sufficient number of runs in each session is ineffective. In the first 2-3 weeks after surgery, active digital flexion should go through only a partial range. In weeks 4-6, the patient gradually moves through the full range. With modifications, I suggest generalization of the partial-range finger motion to therapy after treating other hand injuries. I consider partial-range active flexion a generalizable working principle for different hand disorders.

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

BACKGROUND

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.

METHODS

Literature search of the available databases.

RESULTS

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.

CONCLUSION

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 OF EVIDENCE

Level 4.

Measurement of finger joint motion after flexor tendon repair: smartphone photography compared with traditional goniometry

The purpose of our study was to determine whether smartphone photography is as reliable and valid as clinical goniometry for measuring interphalangeal joint range of motion. We conducted a retrospective review of 37 fingers in 33 patients after flexor tendon repair. The measurements on photographs taken with a smartphone by a surgeon were compared with manual measurements with goniometry by the same surgeon. Pearson coefficients and interclass correlation coefficients were all above 0.85, and Bland-Altman analysis demonstrated that at least 35 of 37 measurements were within the 95% confidence interval in all variables. According to the Tang criteria, the total number of excellent and good results were equivalent according to both methods. There was high interobserver reliability between measurements by surgeons and a therapist. We conclude that if the pictures are properly taken, the measurement of the angles in the smartphone pictures are as reliable as measuring the angles with goniometry and that grading of the results according to the two methods gives identical results.

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 15 days (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.

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

BACKGROUND

In 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 METHODS

60 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.

RESULTS

Stable 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.

CONCLUSION

Fiberwire 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.

Combined nerve, vessel, and tendon injuries of the volar wrist: Multidisciplinary treatment and functional outcomes

The superficial location of critical structures, including tendons, nerves and vessels, in the volar surface of the wrist makes them vulnerable to penetrating trauma. Extensive injuries to these structures are described as "spaghetti wrist". The main objective of this study was to report functional outcome in spaghetti-wrist injuries. The records of patients presenting to our clinic with extensive volar wrist injuries between January 2016 and January 2019 were reviewed retrospectively. Age, gender, comorbidities, date of injury, injury mechanism, affected hand and transected structures were noted. Tendon function, opposition, intrinsic hand function, deformity and sensitivity were evaluated following the Noaman report. The Michigan Hand Outcomes Questionnaire (MHOQ) was used to evaluate hand-specific outcomes. Twenty patients were included. Mean age was 32.7 years (range, 18-47 years). Mean follow-up was 21.9 months (range, 12-50 months). Mean number of injured structures was 11.9 (range, 10-16 structures) per patient. Physiotherapy duration had an effect on postoperative outcome in all six MHOQ domains (r = 0.821, p = 0.00001). However, no significant difference in overall hand function was found according to the number of injured structures (r = -0.105, p = 0.661). Precise initial evaluation, meticulous surgical treatment within 24 h and early physical therapy are essential after spaghetti-wrist injury. Good functional results are associated with prolonged physical therapy, but not with the number of structures injured.

Flexor tendon injuries: Repair & Rehabilitation

Flexor tendon injuries are common and occur mostly by penetrating trauma. Suspected flexor tendon injuries require a thorough clinical assessment and often are not isolated injuries. A detailed understanding of flexor tendon anatomy and spatial relationships is essential, especially when repairing multi-tendon injuries. Principles of flexor tendon repair include a strong suture construct, minimising gap formation between tendon ends, preserving tendon blood supply and providing a smooth repair interface. Moreover, adequate exposure of the zone of injury using full-thickness skin flaps and preservation of neurovascular and pulley structures is essential. In this article an overview of contemporary management strategies is presented. Today's hand surgeons and therapists can choose from a variety of treatment options when managing these important and potentially life-changing injuries.

Management of spaghetti wrist under WALANT technique

This study aimed to evaluate the effectiveness of the WALANT technique in managing spaghetti wrist lacerations. Thirteen consecutive patients with spaghetti wrist laceration were operated on under WALANT technique and followed prospectively. All patients were operated on by the same hand surgeon in a university hospital setting. At the final follow-up, arterial patency, tendon repair, nerve regeneration, handgrip strength and overall patient satisfaction were assessed. All patients were male, with a mean age of 23.8 ± 7.7 years (range, 18-42). The mean waiting time from admission to operation was 33.6 ± 5.1 min (range, 26-42). The operation lasted a mean 119.6 ± 33.8 min (range, 75-185). Mean time from admission to discharge was 269.3 ± 35.0 min (range, 225-341). Mean VAS for intraoperative pain was 1.0 ± 0.9 points (range, 0-3). Patients were followed up for at least 6 months: mean 9.8 ± 1.6 months (range, 7-12). Ten of the 12 repaired arteries were patent and 2 were occluded at the final follow-up. Six of the 17 repaired nerves were evaluated as excellent, 9 as good and 2 as fair on 2-point discrimination test. Total active range of motion was perfect in 6 patients, good in 6, and fair in 1. Grip strength was averaged 86.8% (range, 76.9-93.5%) of the contralateral value. All patients were either very satisfied (n: 9) or satisfied (n: 4). The WALANT technique can be used for spaghetti wrist lacerations involving the tendons, arteries and nerves, with favorable outcome. Major arterial anastomosis can be performed without any surgical limitation.

Getting Better Results in Flexor Tendon Surgery and Therapy

Recently, better outcomes have been reported when up-to-date developments in flexor tendon surgery and therapy were followed. Slightly tensioned multistrand repairs, judicious venting of pulleys, and early active motion are widely accepted principles. In addition to these principles, tailoring of the repair according to intraoperative active movement with wide awake local anesthesia no tourniquet (WALANT) surgical setting is recommended for better results. We aimed to describe our up-to-date approach to flexor tendon surgery and therapy with the help of visual communication tools of this age. The ideal primary repair of flexor tendons, the management of delayed presentation flexor tendon injuries, the key steps to achieve better results with flexor tendon therapy, and the tele-rehabilitation experience during COVID-19 pandemic will be highlighted. Zone 2 flexor tendon injuries are the most demanding part and will be focused on.

Plastic surgery procedure unit: A streamlined care model for minor and intermediate procedures: A cost-benefit analysis

INTRODUCTION

The advent of wide-awake local anaesthesia has led to a reduced need for main theatre for trauma and elective plastic procedures. This results in significant cost-benefits for the institution. This study aims to show how a dedicated 7 days/ week plastic surgery procedural (PSP) unit, performing both elective and trauma surgeries, can lead to significant cost-benefits for the institution.

METHODS

Retrospective review of all cases performed in the PSP unit between 1 September and 31 August 2018. We utilised hospital directory admissions data and the hospital's intranet operating theatre system to calculate hospital days saved. Cost analysis was performed using Saolta financial data.

RESULTS

A total of 3058 operations were performed. Of these operations, 2388 cases were elective and 670 were trauma cases. The average waiting time for trauma cases for main operating theatre was 1.4 days, saving a total of 487 hospital days. The total savings associated with hospital bed days were €347,861. The estimated resource savings from performing a procedure in PSP compared with main theatre with regional anaesthesia were €529.00 and €391.00 without regional anaesthesia. The cost saved due to resources was therefore €337,226. The total cost-benefit associated with performing surgeries in PSP including hospital days and resources saved was calculated as €685,087.

CONCLUSION

This study shows the benefit of performing elective and trauma operations in minor procedure units such as PSP. PSP results in a more efficient service, reducing waiting times for surgery, shorter hospital stay, reduced operating cost and an overall significant cost saving.

Zone 2 Flexor Tendon Repair Location and Risk of Catching on the A2 Pulley

PURPOSE

To determine the region of the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendons in zone 2 that, when involved by a laceration repair, will reliably catch on the A2 pulley after surgery.

METHODS

Using fresh-frozen cadavers (5 hands, 20 digits), excursions of the FDP and FDS tendons were measured in relation to the A2 pulley. The C1, A3, and C2 pulleys were resected. The digit was maximally flexed by applying traction to the flexor tendon in the forearm. An 8-0 suture tag was placed in the flexor tendons immediately distal to the A2 pulley. The digit was then passively fully extended to measure tendon excursion. Measurements were repeated with 50% venting and 100% release of the A4 pulley. Reference points such as tendon insertions and flexion creases were obtained. This protocol was repeated sequentially for the index, middle, ring, and little fingers.

RESULTS

For all 20 fingers, the suture placed into the FDP just distal to the A2 pulley with the finger fully flexed traveled 1.6 ± 1.9 mm distal to the proximal edge of the A4 pulley with passive extension of the finger. The mean excursion for the FDP was 24.6 ± 3.2 mm, and 16.9 ± 3.1 mm for the FDS. The mean A2 pulley length was 16.2 ± 3.5 mm, and the mean distance between the distal edge of the A2 pulley and the proximal edge of the A4 pulley was 23.0 ± 3.3 mm. Venting the A4 pulley 50% and 100% increased FDP excursion a maximum of 0.9 and 1.9 mm, respectively.

CONCLUSIONS

An FDP repair proximal to the A4 pulley will slide under the A2 pulley with full active digital flexion after surgery. If the distal FDP stump lies underneath the A4 pulley with the digit fully extended, the FDP repair will not likely engage the A2 pulley with full flexion after surgery. The FDP excursion can be reliably predicted as a percentage of the A2 (distal) to the A4 (distal) pulley distance. Most importantly, the distance between the repair site and the A4 pulley approximately equals the length of the A2 pulley that requires release to avoid postoperative triggering.

CLINICAL RELEVANCE

Knowledge of this high-risk region of flexor tendon repair will guide surgeons regarding the potential need for partial release of the A2 pulley.

Wide awake surgery for flexor tendon primary repair: A literature review

Flexor tendon injuries are extremely challenging conditions to manage for hand surgeons. Over the last few years enormous progress has been made for the treatment of these lesions with new surgical approaches being performed. One of these is the wideawake local anesthesia no tourniquet (WALANT) technique, also known as Wide Awake Technique that allows tendon repair under local anesthesia, enabling the tendon to move actively during surgery. Dynamic movement of the tendon during surgery is crucial for the orthopedic surgeon in order to understand if the tendon has been correctly repaired before leaving the operatory table. An electronic literature research was carried out on Pubmed, Google Scholars and Cochrane Library using ((Flexor tendon injury) OR (flexor tendon) OR (injury muscle tendon) OR (flexor pollicis longus tendon) AND ((wide awake repair) OR (wide awake) OR (wide awake hand surgery))as search terms. Authors believe that WALANT is an enormous add-on in the management of patients with flexor tendon injuries mainly because it allows direct visualization of the repair during flexion and extension movement of the fingers and also because it avoids general anesthesia or brachial plexus being more cost effective. The aim of these review was therefore to sum up the evidences available so far on the wade awake technique as an emerging treatment for patients with flexor tendon injuries.

Flexor Tendon Grafting Using Extrasynovial Tendons Followed by Early Active Mobilization

Purpose

This study evaluated the outcomes of early active mobilization after flexor tendon grafts using extrasynovial tendons with a novel distal fixation technique.

Methods

This study was a retrospective case series. The flexor digitorum profundus (FDP) tendons of 7 digits in 7 patients were reconstructed with extrasynovial tendons, which included the palmaris longs, plantaris, and extensor digitorum longus, in a single- or 2-stage procedure between 2008 and 2017. Of the 7 patients, 6 were male and the average patient age was 48 years. The injuries involved 2 middle, 2 ring, and 3 little fingers. The tendons were sutured into the appropriate FDP tendon proximally using end-weave anastomosis; the distal end of the graft was fixed to the distal stump of the FDP using an interlacing suture or a small bone anchor combined with the pull-through technique. The digits were mobilized with a combination of active extension and passive and active flexion in a protective orthosis during the first 6 weeks after surgery. Average follow-up was 18 months. We measured active and passive digit motion both before tendon grafting and at the final evaluation. Outcomes were graded by the LaSalle formula to assess staged flexor tendon reconstruction.

Results

Average passive range of motion (ROM) of the proximal and distal interphalangeal joints before flexor tendon grafting was 146° (SD, 22°). Mean active ROM of these joints at the final evaluation was 123° (SD, 34°). Using the LaSalle formula, mean recovery of active motion was 83%. We encountered no grafted tendon rupture and no finger required tenolysis.

Conclusions

Our proximal and distal fixation techniques allowed the autologous extrasynovial tendon grafts to withstand the stress encountered during early active mobilization with good postoperative ROM and minimal complications.

Type of study/level of evidence

Therapeutic I.

Effects of a Q Suture Technique on Resistance to Gap Formation and Tensile Strength of Repaired Tendons: An Ex Vivo Mechanical Study

PURPOSE

The repair of digital flexor tendons following laceration should aim to prevent gapping at the repair site and restore the tensile strength of the tendons to facilitate postoperative movement. We present here a simple Q suture and test its effects on gap formation and tensile strength of the repaired tendons.

METHODS

Sixty porcine tendons were repaired with 3 2-strand sutures (Kessler, Kessler plus 2Q, and Kessler plus running sutures) and 3 4-strand sutures (double Kessler, double Kessler plus 2Q, and double Kessler plus running sutures). The specimens were subjected to a cyclic loading. At each cycle, the number of tendons that initiated gapping or formed a 2-mm gap at the repair site was determined. After the cyclic load testing, the gap distance between tendon ends and the ultimate strength of the repaired tendons was measured.

RESULTS

In both 2-strand and 4-strand tendon repairs, augmentation by insertion of the 2Q sutures reduced the number of tendons that showed 2-mm gaps ends during loading. Compared with the single Kessler and Kessler plus running sutures, Kessler plus 2Q suture significantly increased the ultimate strength of the tendon repair. Compared with the double Kessler and double Kessler plus running sutures, double Kessler plus 2Q suture significantly decreased the gap distance at the repair site after cyclic loading.

CONCLUSIONS

The Q suture technique effectively enhances the resistance to gap formation of 2-strand and 4-stand tendon repair. It also improves the tensile strength of 2-strand Kessler repairs.

CLINICAL RELEVANCE

The Q suture is a simple technique that can resist gap formation and strengthen the tensile strength of the repaired tendons in the laboratory setting.