Outcomes of the six-strand M-Tang repair for zone 2 primary flexor tendon repair in 54 fingers

Comparison of Treatment Outcomes of Different Immobilized Finger Positions After Repair of Flexor Tendon Rupture in Zones I and II: A Nonrandomized Controlled Trial With Historical Control Group

Introduction The position of finger immobilization after flexor tendon rupture repair is changed to the extended position to prevent flexion contracture of the interphalangeal (IP) joint. However, in Strickland's assessment, We believe that a reduction in TAF (total active flexion) affects the outcome and that extension fixation is not necessarily the primary focus. For example, there are management methods that swap the fixed position between day and night. It is assumed that some effect is sought by placing the fingers in the flexed position. That is, the method of fixation is currently selected at individual facilities through twists and turns; however, the indications and criteria for selecting finger fixation positions are ambiguous, and they are apparently subject to the experience of therapists. This study aimed to characterize follow-up outcomes of flexion and extension fixation after zones I and II flexor tendon rupture repair. Methods This nonrandomized controlled trial with historical controls included 25 patients with flexor tendon ruptures of 30 fingers. The flexion fixation group consisted of 12 patients (n=16 fingers) and the extension fixation group consisted of 13 patients (n=14 fingers). The group with flexion fixation comprised patients who slept with their injured fingers in the flexed position (intervention group). The group with extension was retrospectively selected between April 2017 and March 2019, who slept with their injured finger in the extended position (historical control group). Strickland assessments of the range of motion (ROM) of each joint at the conclusion of hand therapy, the ratio of total active motion of the repaired, to the healthy finger (%TAF), and IP joint extension limitation angles were compared using Mann-Whitney U tests. Ratios of excellent and good ratings based on the Strickland assessment were compared using Fisher exact tests. Result The results of the Strickland assessment showed excellent or good outcomes for 22 (73%) of 30 fingers, which was in line with our previous findings. Strickland ratings of excellent were achieved in seven (44%) of 16 fingers and four (28%) of 14 fingers in the groups with flexion and extension fixation, respectively. The outcomes for two (22%) of 16 fingers and seven (78%) of 14 fingers in the groups with flexion and extension fixation were, respectively, rated as good. The proportion of patients rated as excellent was significantly higher in the group with flexion than extension fixation (p=0.040). The %TAF and the active flexion angle of the distal interphalangeal (DIP) joint were higher in the group with flexion than extension fixation (p=0008 and p=0.025, respectively). Furthermore, the total angle of the IP joint limit of extension did not significantly differ between the groups. Conclusion Flexion fixation after flexor tendon rupture achieved an excellent Strickland rating and was more effective than extension fixation, especially in terms of the active flexion ROM of the DIP joint. Flexion fixation might be an alternative to extension fixation because the range of flexion should be greater and might provide a range of finger extension motion equivalent to that of extension fixation.

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

PURPOSE

The Q suture has been reported to be an effective alternative to conventional peripheral sutures in tendon repair. Whether the Q method can be used as a core suture rather than a peripheral suture by adjusting the purchase length is unknown. We tested a double Q suture technique with variable purchase length and studied its effects on gap formation and tensile strength using an ex vivo model.

METHODS

Forty pig flexor tendons were repaired using the double Q sutures with purchase lengths of 2, 4, 6, and 8 mm. Twenty tendons repaired using the double Tsuge and double Kessler sutures with an 8-mm purchase length were used as controls. The tendons were subjected to cyclic loading and load-to-failure. The number of tendons that formed an initial or 2-mm gap between the tendon ends, gap distance at the repair site, stiffness, and ultimate strength were recorded.

RESULTS

During cyclic loading, the double Q suture with a 4-8-mm purchase had fewer tendons form an initial or 2-mm gap and a smaller gap size at the repair site than the Tsuge and Kessler sutures. The stiffness of the double Q suture with a 6-8-mm purchase length and Tsuge suture was greater than those of the double Kessler suture. The double Q suture with a 2-mm purchase length had smaller ultimate strength than the other sutures.

CONCLUSIONS

The Q suture may be an effective tendon repair method whose role can be converted between peripheral and core sutures via adjusting the suture purchase length. With an optimal suture length of 4-6 mm, the double Q method had tensile resistance superior to 4-strand core sutures.

CLINICAL RELEVANCE

The double Q suture may be a viable option as a core suture in flexor tendon repair when the purchase length is appropriately adjusted.

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.

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.

Early active movement with relative motion flexion splint for the management of zone 1-2 flexor tendon repairs: Case series

BACKGROUND

There is limited literature evidence on the use of relative motion flexion splint after flexor tendon repairs.

OBJECTIVES

We aimed to report the clinical use of early active movement with a relative motion flexion splint and to determine the outcomes of a consecutive series in patients with zone 1-2 flexor tendon repair.

METHODS

We included 14 patients with one-stage flexor tendon repair. An active rehabilitation program was initiated in the first week with a static dorsal block splint, which was removed in the third week, and patients started to use the relative motion flexion splint. Total active motion (TAM) of the injured finger at 8, 12, and 16 weeks after surgery was assessed as described by Strickland and Glogovac.

RESULTS

The mean TAM of the injured fingers was as follows: 102.5 ± 41.49° (25°-180°) at week 8; 123.42 ± 40.94° (45°-190°) at week 12; and 148 ± 38.18° (90°- 200°) at week 16. Final TAM grades of the patients at week 16 were as follows: excellent (six patients); good (five patients); and fair (three patients). There were no tendon ruptures and secondary surgeries.

CONCLUSION

Early active movement and the use of relative motion flexion splint seem to be promising strategies for flexor tendon zone 1-2 repair management.

Encircling tendon repair site with collagen sheet in flexor zone 2: retrospective study

BACKGROUND

Peritendinous adhesion is the most common complication of tendon repairs in the hand and often requires surgical intervention, resulting in increased labor loss and increased treatment costs. Many agents used to reduce tendon adhesion in animal models, however these agents have not entered clinical use. This study is the first-ever clinical study that evaluates encircling tendon repair site with collagen sheet as an anti-adhesion barrier.

METHODS

Between December 2014 and January 2020, 156 patients included in this study, with clean cut isolated flexor digitorum profundus (FDP) tendon injury in flexor tendon zone 2. All tendons repaired with modified double Kessler technique. In 76 patients, tendon repair site encircled with collagen sheet. 80 patients were randomly selected from our clinical records and functional results are compared with Strickland's total active motion grading system.

RESULTS

The mean total range of motion was 79% in the control group and 81% in the collagen sheet group, and there was no statistically significant difference between the two groups (Z: - 1.393, p = 0.164). In the control group, very good and good repair according to Strikland classification was 65/80 (81%). In the collagen sheet group, it was 62/76 (82%), respectively. There was statistically significant difference between 5 FDP TAM measurements between collagen sheet and control group (t(35) = 0.29, p = 0.016, p < 0.05). The mean TAM of the 5 FDP tendons in the collagen sheet group: 83.8 (SD: 8.2) in the and 76.1 (SD: 9.5) in the control group.

CONCLUSIONS

For the first time in the literature, functional results of Zone 2 flexor tendon repair using collagen sheets in patients with clean cut tendon injuries reported. However, there were no statistical difference about total active motion between control and collagen sheet group, 5th FDS tendon repairs encircled with collagen sheets had better outcomes. Prospective studies in patient groups with high adhesion risk are recommended.

Outcomes of Primary Flexor Tendon Repairs in Zones 2 and 3: A Retrospective Cohort Study

Purpose

The aims of this retrospective cohort study were to present outcomes of zone 2 and 3 primary flexor tendon repairs and to evaluate how clinical outcomes change over time within and between zones of injury at weeks 6, 13, and 26.

Methods

Data were retrieved from a multicenter flexor tendon cohort registry from 2014 to 2021. The inclusion criteria were: (1) adult patients after primary flexor tendon surgery in zone 2 or 3, (2) flexor digitorum profundus laceration of >50%, (3) 4-6 multistrand flexor digitorum profundus core suture, and (4) early active motion protocol. The primary outcome was the range of motion. Secondary outcomes were strength, patient satisfaction on an 11-point Likert scale, and self-reported physical function measured with the Disability of the Arm, Shoulder, and Hand questionnaire 6, 13, and 26 weeks after surgery.

Results

We evaluated 33 patients after 39 tendon repairs in zone 3 and 174 repairs in zone 2 of 163 patients. Range of motion significantly improved over time in both zones (P < .001 to .01). Between-group range of motion differences were nonsignificant except for week 26 (P < .001) for the zone 3 group. Hand strength significantly improved in both zones over time (P < .001 to .01), while between-zone strength differences were statistically nonsignificant (P = .37 to .93). Patient satisfaction was generally good to high (mean 6.8 to 8.0 points) with significant within-group changes in both zones (P < .001). There were no relevant between-zone differences in Disability of the Arm, Shoulder, and Hand scores at any time point.

Conclusions

Patients had significantly improved clinical outcomes in both zones. The zone of injury significantly affected the total active motion scores at the final assessment after 26 weeks for the zone 3 injuries. For the secondary outcomes hand strength, patient satisfaction, and Disability of the Arm, Shoulder, and Hand scores, we discovered no significant between-group differences.

Type of study/level of evidence

Therapeutic IV.

Relationship between pain, nerve injury and clinical outcomes after flexor tendon injuries in zones 1-2: a retrospective cohort study

Introduction

The influence of pain and a concomitant digital nerve injury on the course of rehabilitation after flexor tendon injury remains ambiguous. The objectives of the study were to: i) analyse the evolution of pain spanning one year after a primary flexor tendon repair in zones 1-3; ii) examine the differences in pain levels in patients with and without digital nerve injury; and iii) evaluate the relationship between pain, digital nerve injury and pain medication, total active motion (TAM), DASH scores and patient satisfaction.

Methods

Data from 189 patients were retrieved from a flexor tendon registry between 2014 and 2020. Differences in pain, TAM, DASH and patient satisfaction were analysed. Multiple linear and binary logistic regression analyses were performed to determine the relationship between clinical outcomes.

Results

Pain significantly decreased in the course of rehabilitation (p < 0.001 to 0.006). No relationship could be identified between nerve injury and pain (p = 0.21-0.97). In week 6, the presence of pain and a nerve injury were significantly associated with lower TAM scores (p = 0.001). In week 13, pain during motion (p < 0.001) and the presence of a nerve injury (p = 0.036) were significantly associated with worse DASH scores. Patient satisfaction was significantly inversely correlated to pain during motion in weeks 13 and 26 (p < 0.001).

Conclusion

We found a significant relationship between pain during motion and pain medication intake, TAM, DASH scores and patient satisfaction. It is therefore advisable to closely monitor this parameter after flexor tendon injuries.

Study registration

This multi-center cohort study is registered under https://clinicaltrials.gov: NCT04312412.

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).

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

BACKGROUND

The effect of obliquity of tendon laceration on repair strength is not well studied. The overwhelming majority of biomechanical studies assess repair strength following a laceration that is perpendicular to the long axis of the tendon. The aim of this study was to investigate whether the angle of tendon laceration affects the core suture strength.

METHODS

In all, 110 fresh human cadaveric flexor tendons were cut at varying angles of 15°, 30°, 45°, and 60° and the control group at 90°. All tendons were repaired with 6-strand modified Tang technique. The repair strength was tested using a custom-made tensioning machine, and the initial static gap force and the ultimate breaking force were measured.

RESULTS

The mean gap force and 95% confidence interval (CI) for the 15°, 30°, 45°, 60°, and 90° groups were 15.2 N (11.4-19.0 N), 15.8 N (13.6-18.1 N), 15.6 N (13.1-18.4 N), 16.6 N (13.7-19.5 N), and 22.3 N (16.6-27.9 N), respectively. In the same respective order, the break force and 95% CI were 25.9 N (21.9-29.8 N), 26.5 N (23.2-29.7 N), 31.1 N (26.1-36.1 N), 35.6 N (28.2-43.1 N), and 51.8 N (62.5-41.0), respectively. The Fisher least significant difference demonstrated significant differences between the control group and all experimental groups for both gap force and break force.

CONCLUSIONS

Obliquity of tendon laceration affects the core suture strength when compared with a transverse cut. Flexor tendons cut at 90° demonstrated a higher overall gap force and breaking strength that were statistically significant when compared with all obliquely cut groups. These findings should be considered when repairing and starting postoperative therapy for obliquely cut tendons.

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.

Altered TGFB1 regulated pathways promote accelerated tendon healing in the superhealer MRL/MpJ mouse

To better understand the molecular mechanisms of tendon healing, we investigated the Murphy Roth's Large (MRL) mouse, which is considered a model of mammalian tissue regeneration. We show that compared to C57Bl/6J (C57) mice, injured MRL tendons have reduced fibrotic adhesions and cellular proliferation, with accelerated improvements in biomechanical properties. RNA-seq analysis revealed that differentially expressed genes in the C57 healing tendon at 7 days post injury were functionally linked to fibrosis, immune system signaling and extracellular matrix (ECM) organization, while the differentially expressed genes in the MRL injured tendon were dominated by cell cycle pathways. These gene expression changes were associated with increased α-SMA+ myofibroblast and F4/80+ macrophage activation and abundant BCL-2 expression in the C57 injured tendons. Transcriptional analysis of upstream regulators using Ingenuity Pathway Analysis showed positive enrichment of TGFB1 in both C57 and MRL healing tendons, but with different downstream transcriptional effects. MRL tendons exhibited of cell cycle regulatory genes, with negative enrichment of the cell senescence-related regulators, compared to the positively-enriched inflammatory and fibrotic (ECM organization) pathways in the C57 tendons. Serum cytokine analysis revealed decreased levels of circulating senescence-associated circulatory proteins in response to injury in the MRL mice compared to the C57 mice. These data collectively demonstrate altered TGFB1 regulated inflammatory, fibrosis, and cell cycle pathways in flexor tendon repair in MRL mice, and could give cues to improved tendon healing.

Six-Strand Flexor Pollicis Longus Tendon Repairs With and Without Circumferential Sutures: A Multicenter Study

BACKGROUND

The purpose of this study is to assess outcomes in flexor pollicis longus tendon repairs with 6-strand core sutures with and without circumferential sutures.

METHODS

A 6-strand core suture technique with and without circumferential sutures was used. Thirty-three patients were summarized in the C group (circumferential group) and 16 patients in the NC group (non-circumferential group). After the surgery, the wrist was stabilized with a dorsal blocking splint and a controlled early active motion protocol was applied. At weeks 6, 13, and 26 data on demographics, type of injury, surgery, postoperative rehabilitation, complications such as re-rupture and the following outcome measurements were collected: range of motion and its recovery according to the Tang criteria, Kapandji score, thumb and hand strengths, Disabilities of the Arm, Shoulder and Hand score, and satisfaction.

RESULTS

There were no significant differences in range of motion and strength between the 2 treatment groups. In both groups, the outcome measurements increased over time and they expressed similar satisfaction with the surgical treatment. In 4 patients of the C group tendon repair ruptured and in 1 patient of the NC group.

CONCLUSIONS

Six-strand repair technique is an effective procedure to assure early active motion after flexor pollicis longus tendon injuries and good results can also be achieved by omitting the circumferential suture.

Management and outcomes of flexor tendon repairs at a peripheral hospital: a New Zealand case series study

BACKGROUND

Current evidence for flexor tendon repair management and outcomes performed at peripheral centres is unclear. Most studies are based on evidence from specialist hand centres. This study evaluated a peripheral hospital in New Zealand; where all flexor tendon repairs were performed by a generalist Orthopaedic service. The purpose of the study was to benchmark management and outcomes from a peripheral hospital in comparison to international standards.

METHODS

A retrospective single-centre consecutive case series of Zones I and II flexor tendon repairs was extracted between 1 January 2014 and 1 January 2018. Medical records were used to evaluate management and outcomes of repairs. Hand therapy notes were used to evaluate rehabilitation protocols provided. The primary objective was to measure re-rupture and re-operation rates. Secondary objectives included auditing operative management and hand therapy compliance.

RESULTS

Forty-six patients (76 tendon repairs) were included in our final analysis. Mean follow up time to last clinical appointment was 11.8 weeks, and to last patient episode was 4.9 years. Most patients received timely surgery with a four-core repair using 3-0 or larger suture. All hand therapy followed a controlled active motion protocol. The re-operation rate was 19.6% (P = <0.05) and the re-rupture rate was 8.7% (P = 0.28).

CONCLUSIONS

Most flexor tendon injuries at this peripheral centre were managed according to international standards. However, high complication rates including re-operation and re-rupture occurred. Due to a lack of local comparison studies, confounding factors cannot be excluded as a contributor for these results.

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.

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

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

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.

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.

Ultrasonographic assessment in vivo of the excursion and tension of flexor digitorum profundus tendon on different rehabilitation protocols after tendon repair

STUDY DESIGN

Interpretive description study.

PURPOSE

In management of patients with flexion tendon injuries, passive, control active and active motion protocols were proposed after repair to minimize tendon adhesion. The purpose of this study was to compare the excursion distance and the tension of Flexor Digitorum Profundus (FDP) during simulated active and passive motion using ultrasonography techniques using normal subjects.

METHODS

Ultrasonographic assessment of FDP tendon of the middle finger was performed at the wrist level on 20 healthy college students using 3 types of treatment protocols: modified Kleinert protocol, modified Duran protocol, and active finger flexion protocol. The excursion distance was measured following the musculotendinous junction of FDP using the B mode ultrasound system. The elasticity of FDP tendon was measured using the shear wave elastography technique. The excursion distance and the elasticity value were compared among 3 protocols using one-way ANOVA analysis.

RESULTS

Twelve male and 8 female students with mean age of 22.6 ± 1.8 years were invited to join the study. The excursion distance of FDP was 21.82 ± 3.77 mm using the active finger flexion protocol, 8.59 ± 2.59 mm using the modified Duran protocol, and 12.26 ± 2.71 mm using the modified Kleinert protocol. The elasticity was significantly higher in extension position when compared to passive flexion positions, but found lower than active flexion position.

DISCUSSION

The active finger protocol was found to require strongest tension of the tendon and with longest excursion. There was similar tension generated using both passive motion protocols. The modified Duran protocol appeared to create less excursion upon movements than the modified Kleinert approach using the objective ultrasonic evaluation. It is suggested that if the surgical repair was strong and without any complications, the active flexion protocol might work best to regain tension excursion. However, if there are complex problems involved, then the Kleinert approach or Duran approach would be chosen.

Flexor digitorum profundus with or without flexor digitorum superficialis tendon repair in acute Zone 2B injuries

A total of 53 patients with complete cuts of two flexor tendons in Zone 2B treated over a 9-year period was reviewed. Twenty-three patients (28 fingers) had only flexor digitorum profundus repair, while 30 patients (36 fingers) had both flexor digitorum profundus and flexor digitorum superficialis repairs, with a mean follow-up of 21 months (range 12-84). The decision to repair the flexor digitorum superficialis was made according to intraoperative judgement of ease of repair and gliding of the flexor digitorum profundus tendon. Two groups of patients showed no significant differences in total range of active or passive digital motion and power grip percentage to the contralateral hand. However, the values of power grip were statistically superior in the patients with both tendons repaired. The patients after flexor digitorum profundus-only repairs showed significantly greater but still mild flexion contracture (mean 20 °) of the operated digits. The Tang gradings were the same with 89% good and excellent rates in both groups. The conclusion is that although repair of both flexor digitorum profundus and flexor digitorum superficialis tendons is slightly more preferable based on increased grip strength, the repair of the flexor digitorum superficialis together with flexor digitorum profundus is not mandatory. Whether or not to repair flexor digitorum superficialis is an intraoperative decision based on the ease of gliding of the repaired tendon(s).Level of evidence: III.

Clinical effect of thumb finger reconstruction using dorsal foot flap transplant for treating thumb defects

It was found that conventional toe graft alone could not meet the patients' needs for wound repair, so we hypothesized that it would be more effective to treat thumb and finger defect by toe graft with dorsalis foot flap. This prospective study was conducted in 104 thumb defect patients to investigate the clinical effect of thumb reconstruction using toe graft with dorsal foot flap for the treatment of thumb defects. These patients were randomly divided into the dorsal foot group and the control group by randomized double-blind method, with 52 patients in each group. The second toe was used for thumb reconstruction transplant in both the groups. After thumb reconstruction, the abdominal pedicled flap was used to repair the surgical wound in the control group whereas the dorsal foot flap was used to repair the surgical wound in the dorsal foot group. Three months after surgery, the efficacy of surgical treatment, evaluation of two-point discrimination, postoperative complications, function of reconstructed thumb, operation time, and hospitalization time were recorded and compared between the two groups. MHOQ questionnaire was used to evaluate and compare the patients' satisfaction with finger reconstruction in both the groups. The surgical therapeutic effect, the function of the reconstructed thumb, and satisfaction with finger reconstruction were significantly higher in the dorsal foot group compared to the control group (all p < 0.05). The postoperative two-point discrimination, postoperative complication rate, operation time, and hospitalization time of patients in the dorsal foot group were significantly lower compared to the control group (all p < 0.05). Thumb finger reconstruction using the second toe transplant with dorsal foot flap had a beneficial effect on thumb defect patients. It can effectively improve finger function and sensory recovery of patients while reducing complications.

Zone 2 flexor tendon repairs using a tensioned strong core suture, sparse peripheral stitches and early active motion: results in 60 fingers

We report the outcomes of zone 2 tendon repairs in 60 fingers using a strong core suture, sparse peripheral stitches and early active motion. From January 2014 to April 2016, we repaired 60 flexor digitorum profundus tendons with a tensioned 4-strand or 6-strand core suture and three to four peripheral stitches. The A2 or A4 pulleys were vented as necessary. Following early active flexion of the repaired tendons, no repairs ruptured and 52/60 (87%) fingers recovered to good or excellent function using the Tang criteria after follow-up of 8-33 months. We conclude that tensioned multi-strand strong core repairs only require sparse peripheral stitches and are safe for early active flexion. Standard peripheral sutures are not necessary. The core sutures should be properly tensioned to prevent gapping at tendon repair site and pulleys should be sufficiently vented to allow tendon motion. Level of evidence: IV.

Wide-Awake Hand Surgery in Two Centers in China: Experience in Nantong and Tianjin with 12,000 patients

This article summarizes the application of local anesthesia no tourniquet in 2 hand surgery centers in China, Nantong and Tianjin, where more than 12,000 patients were operated on with the new approach. This approach achieves excellent anesthetic and vasoconstrictive effects. In Nantong, surgeons performed fracture fixation, soft tissue tumor excision, and flap transfer in the hand with this approach. In Tianjin, surgeons applied it to cases of hand trauma emergency surgery. The authors' experience shows that this approach to hand surgery is safe, economical, and patient friendly, with no increase in infection rate.

Impact of Wide-Awake Local Anesthesia No Tourniquet on Departmental Settings, Cost, Patient and Surgeon Satisfaction, and Beyond

This article reviews the impact of wide-awake hand surgery without tourniquet on departmental settings and savings on patients' medical cost, and efficiency of fellowship training and practice of junior hand surgeons in 3 units in 3 countries. The medical cost of the commonly performed procedures is decreased remarkably with this approach in the 3 units. Hand surgery fellowship training and practice of junior surgeons are benefited from this approach in 2 units in Turkey and Switzerland. Overall, this approach improves the surgeons' and patients' quality of life and its application is expanding to almost all procedures of hand surgery.

Comparison of the strength of two multi-strand tendon repair configurations in a chicken model

We sought to investigate the strength of two multi-strand tendon repair configurations in a chicken model. Fifty-six chicken flexor tendons were repaired with one to two different four-strand configurations: 1) a four-strand repair consisting of a two-strand core modified Kessler suture with a circle loop repair and 2) a four-strand core Kessler suture repair with three separate peripheral suture points. The strength of the repaired tendons were measured 2, 3 and 4 weeks after the surgical repair and were analyzed statistically. The strength of the two repair methods was not statistically different 2 weeks after surgery. The tendons repaired with the four-strand core Kessler suture repair and three separate peripheral suture points were significantly stronger than those repaired with a two-strand core modified Kessler suture and a circle loop repair at 3 weeks (P = 0.033) and 4 weeks (P = 0.039). The four-strand repair with three separate peripheral suture points had greater strength than a two-strand repair with one circle loop suture based on an in vivo chicken flexor tendon model.

New Developments Are Improving Flexor Tendon Repair

New developments in primary tendon repair in recent decades include stronger core tendon repair techniques, judicious and adequate venting of critical pulleys, followed by a combination of passive and active digital flexion and extension. During repair, core sutures over the tendon should have sufficient suture purchase (no shorter than 0.7 to 1 cm) in each tendon end and must be sufficiently tensioned to resist loosening and gap formation between tendon ends. Slight or even modest bulkiness in the tendon substance at the repair site is not harmful, although marked bulkiness should always be avoided. To expose the tendon ends and reduce restriction to tendon gliding, the longest annular pulley in the fingers (i.e., the A2 pulley) can be vented partially with an incision over its distal or proximal sheath no longer than 1.5 to 2 cm; the annular pulley over the middle phalanx (i.e., the A4 pulley) can be vented entirely. Surgeons have not observed adverse effects on hand function after judicious and limited venting. The digital extension-flexion test to check the quality of the repair during surgery has become increasingly routine. A wide-awake surgical setting allows patient to actively move the digits. After surgery, surgeons and therapists protect patients with a short splint and flexible wrist positioning, and are now moving toward out-of-splint freer early active motion. Improved outcomes have been reported over the past decade with minimal or no rupture during postoperative active motion, along with lower rates of tenolysis.

Biomechanical comparison of modified Lim/Tsai tendon repairs with intra- and extra-tendinous knots

We compared the Lim/Tsai tendon repair technique using an extra-tendinous knot with modification using an intra-tendinous knot. The ultimate tensile strength, load to 2 mm gap force, stiffness, mode of failure, location of failure, and time taken to repair each tendon were recorded during a single cycle loading test in 20 tendons with each repair method. We found that the ultimate tensile strength and 2 mm gap force of the modified Lim/Tsai repair with an extra-tendinous knot (56 SD 5 N and 14 SD 2 N, respectively) were statistically significantly higher than that of the modified Lim/Tsai repair with intra-tendinous knot (51 SD 7 N and 11 SD 2 N, respectively). We conclude that the modified Lim/Tsai repair with extra-tendinous knot is stronger, despite having the same number of core strands.

Recent evolutions in flexor tendon repairs and rehabilitation

This article reviews some recent advancements in repair and rehabilitation of the flexor tendons. These include placing sparse or no peripheral suture when the core suture is strong and sufficiently tensioned, allowing the repair site to be slightly bulky, aggressively releasing the pulleys (including the entire A2 pulley or both the A3 and A4 pulleys when necessary), placing a shorter splint with less restricted wrist positioning, and allowing out-of-splint active motion. The reported outcomes have been favourable with few or no repair ruptures and no function-disturbing tendon bowstringing. These changes favour easier surgeries. The recent reports have cause to re-evaluate long-held guidelines of a non-bulky repair site and the necessity of a standard peripheral suture. Emerging understanding posits that minor clinically noticeable tendon bowstringing does not affect hand function, and that free wrist positioning and out-of-splint motion are safe when strong surgical repairs are used and the pulleys are properly released.

Results of heterodigital flexor digitorum profundus hemi-tendon transfer for 23 flexor tendon injuries in zones 1 or 2

We report outcomes of reconstruction of zone 1 or 2 flexor tendon injuries using a heterodigital hemi-tendon transfer of the flexor digitorum profundus in 23 fingers of 23 patients. At mean follow-up of 57 months, the mean total active motion of the three finger joints including the metacarpophalangeal joint was 128 degrees preoperatively and 229 degrees at final follow up. According to Strickland criteria, the function was excellent for 14 fingers, good for seven fingers and poor for two fingers. The subgroup analysis showed that the results were better in cases of primary surgery, children, and for the index and little fingers. Complications included stiffness of three fingers, and rupture in one finger that was converted to a two-stage tendon reconstruction. We conclude that this technique restores good function in most patients with zone 1 and 2 flexor tendon injuries, in which primary tendon repair has not been performed or was unsuccessful, and where pulley reconstruction is not required.

LEVEL OF EVIDENCE

IV.

Sonographic study of repair, gapping and tendon bowstringing after primary flexor digitorum profundus repair in zone 2

We report sonographic findings with clinical outcomes after zone 2 flexor digitorum profundus tendon repairs in ten fingers. The tendons underwent a six-strand M-Tang core repair, no circumferential suture, and partial or complete division of the pulleys. Over 12 months after surgery and using ultrasound, we found no gapping at the repair site during finger motion. When the pulleys were divided, there was sonographic evidence of tendon bowstringing, but the bowstringing was minimal. Clinically, we did not find any fingers that displayed tendon bowstringing or had functional loss. With ultrasound examination, the repaired tendons remained enlarged over 12 months. Two patients developed heterotopic ossifications at the repair site without tendon gliding, and these required tenolysis. We conclude that the tendon repair site does not gap when a strong core suture is used in the repair without adding peripheral sutures. There is no notable tendon bowstringing clinically, though the repaired tendons have sonographic evidence of minor bowstringing.

LEVEL OF EVIDENCE

III.

Flexor tendon repair in the hand with the M-Tang technique (without peripheral sutures), pulley division, and early active motion

We report outcomes in 29 patients with flexor tendon repairs in 32 digits (five thumbs and 27 fingers) with our modified protocols. We repaired the lacerated flexor digitorum profundus tendons with core suture repairs using the 6-strand M-Tang method and without circumferential sutures. We divided the pulleys as much as needed to allow excursion of the repaired tendons, including complete division of the A4 or A2 pulleys when necessary. In nine fingers, we repaired one slip of the flexor digitorum superficialis tendon and resected the other half. When the flexor digitorum profundus tendon would not glide under the A2 pulley, we excised the remaining slip of the flexor digitorum superficialis tendon. The wrist was splinted in mild extension post-surgery with early commencement of tenodesis exercises. No tendon repair ruptured. By the Strickland criteria, out of 27 fingers, 18 had excellent, six had good, two had fair, and one had poor results. We conclude that a strong core suture (such as the M-Tang repair) without peripheral sutures, and with division of pulleys as necessary is safe for early active motion and yields good outcomes.

LEVEL OF EVIDENCE

IV.

Localized delivery of miRNAs targets cyclooxygenases and reduces flexor tendon adhesions

The formation of adhesions during healing of an injured tendon remains a difficult problem in clinical practice. Local anti-inflammation gene delivery provides high local gene concentration, reduces the inflammatory response of the injured tendon microenvironment, and decreases systemic side effects to enhance in vivo efficacy. In this study, we designed a novel local sustained gene delivery system by using cyclooxygenase (COX-1 and COX-2)-engineered miRNA plasmid/nanoparticles embedded in hyaluronic acid (HA) hydrogel to reduce flexor tendon adhesions. The local sustained gene delivery system significantly downregulates COX-1 and COX-2 expression in the tendon tissue and the surrounding subcutaneous tissue. More importantly, this plasmid/nanoparticle hydrogel system significantly reduced tissue adhesion formation. This approach offers an effective therapeutic strategy to reduce tendon adhesions by directly targeting the down-regulation of COX-1 and COX-2 expression within the microenvironment of the injured tendon.

STATEMENT OF SIGNIFICANCE

A local sustained gene delivery system was developed to regulate the expression of targeted genes in the specific time and location for tendon adhesion treatment. The engineered miRNA plasmid/nanoparticles embedded in hyaluronic acid hydrogel were synthesized to downregulate the expression of cyclooxygenases in the tendon tissue during the early stage of tendon healing with inflammatory response. This plasmid/nanoparticle hydrogel system offers an effective therapeutic strategy to attenuate the formation of tendon adhesion through direct downregulation of COX-1 and COX-2 expression within the microenvironment of the injured tendon.

Biomechanical comparison of the Lim/Tsai tendon repair with a modified method using a single looped suture

The Lim/Tsai tendon repair technique has been modified clinically to achieve a 6-strand repair using a single looped suture with one extratendinous knot. We compared biomechanical performance of the original and modified methods using 20 porcine flexor digitorum profundus tendons. The ultimate tensile strength, load to 2 mm gap force, mode of failure, and time taken to repair each tendon were recorded during a single cycle loading test in 10 tendons with each repair method. We found that despite having the same number of core strands, the single looped suture modified Lim/Tsai technique possessed significantly greater ultimate tensile strength and load to 2 mm gap force. Also, less repair time was required. We conclude that the modified 6-strand repair using a single looped suture has better mechanical performance than the original method. The difference likely was due to the changes in locations of the knots and subsequent load distribution during tendon loading.

Robust thumb flexor tendon repairs with a six-strand M-Tang method, pulley venting, and early active motion

We present the outcomes of flexor pollicis longus tendon repairs in 34 thumbs using a six-strand M-Tang repair with venting of one or two pulleys according to site of tendon laceration. The A2 pulley was vented in all three thumbs with zone 1 injury. In 31 thumbs with zone 2 injuries, the oblique pulley was vented partially or entirely. Twenty-two thumbs had both the A1 and oblique pulleys vented. Six to 46 months post-surgery, 14 thumbs with zone 2 injuries were rated excellent, 13 good, three fair and one failure according to Tang criteria. No tendon ruptures or bowstringing occurred. Fourteen of 34 thumbs had deficits in interphalangeal joint extension averaging 13°. We conclude that venting of one or two pulleys may ensure recovery of thumb function without risking tendon bowstringing and that early active thumb motion is safe with a robust tendon repair.

LEVEL OF EVIDENCE

IV.

Common Hand Problems with Different Treatments in Countries in Asia and Europe

Common hand problems are treated differently in different countries. This article attempts to bring together the views of surgeons from different countries on some of the most common hand problems that hand surgeons encounter in daily practice. In practice, the correct treatment of these problems may be the most important and influential to patients.

Performing Hand Surgery Under Local Anesthesia Without a Tourniquet in China

In China, wide-awake surgeries are increasingly used by surgeons in a growing number of hospitals for hand and upper extremity surgeries. Experience suggests that wide-awake surgery is safe, economical, and patient-friendly, optimizing hospital resource allocation and increasing efficiency. This article discusses which procedures are most suitable, variations in procedures, departmental impacts, and future direction.

Primary Flexor Tendon Repair with Early Active Motion: Experience in Europe

The protocol for primary flexor tendon repair in zones 1 and 2 of the hand is changing. This article discusses recent changes. Immediate repair within 48 hours is performed whenever possible. A 6-strand core suture is performed using the M modification of Tang's technique. The pulleys are divided to allow free excursion of the repaired tendon within the tendon sheath. To avoid repaired structures within the sheath being too bulky, the authors generally repair only half of the flexor digitorum superficialis. In some cases, the flexor digitorum superficialis is excised completely. Rehabilitation remains based on controlled active motion.

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

Over the past 2 decades, repair and rehabilitation methods of primary repair of the digital flexor tendon have changed. In this article, we outline interim results from ongoing investigations in several units. Surgeons in these units now perform digital flexor tendon repairs according to a treatment protocol. Before adopting the protocol, they had no history of tendon-related research; they had not used any of the repair and rehabilitation methods described in the protocol. The surgeons involved are junior or midlevel attending surgeons. At the end of this article, we outline current practice of digital flexor tendon repair in Asian countries.