Zone II Flexor Tendon Repairs in the United States: Trends in Current Management

Flexor Tendon Injuries

Flexor tendon injuries are complex, and management of these injuries requires consideration of the surgical timing, injury location, approach, and soft tissue handling. Complications are common, including adhesions, tendon rupture, infection, and a high reoperation rate for zone 2 repairs. Special considerations are given to chronic ruptures, concomitant fractures, and pediatric cases. We discuss current concepts that may improve patient outcomes.

Zone-specific pitfalls in flexor tendon rehabilitation: management and prevention

Despite significant advancements in flexor tendon repair techniques and rehabilitation strategies, achieving complete restoration of digital motion remains a formidable challenge. The most prevalent complications associated with tendon repair are the development of tendon adhesions and joint contractures. Left unaddressed, these complications can further lead to secondary pathomechanical changes, resulting in fixed deformities significantly affecting hand function. This review of zone-specific considerations in flexor tendon rehabilitation provides an in-depth analysis of the dynamics of tendon motion after repair and strategies to minimize common secondary complications.

Current clinical opinion on surgical approaches and rehabilitation of hand flexor tendon injury-a questionnaire study

The management of flexor tendon injury has seen many iterations over the years, but more substantial innovations in practice have been sadly lacking. The aim of this study was to investigate the current practice of flexor tendon injury management, and variation in practice from the previous reports, most troublesome complications, and whether there was a clinical interest in potential innovative tendon repair technologies. An online survey was distributed via the British Society for Surgery of the Hand (BSSH) and a total of 132 responses were collected anonymously. Results showed that although most surgeons followed the current medical recommendation based on the literature, a significant number of surgeons still employed more conventional treatments in clinic, such as general anesthesia, ineffective tendon retrieval techniques, and passive rehabilitation. Complications including adhesion formation and re-rupture remained persistent. The interest in new approaches such as use of minimally invasive instruments, biodegradable materials and additive manufactured devices was not strong, however the surgeons were potentially open to more effective and economic solutions.

WAFER trial: a study protocol for a feasibility randomised controlled trial comparing wide-awake local anaesthesia no tourniquet (WALANT) to general and regional anaesthesia with tourniquet for flexor tendon repair

INTRODUCTION

Flexor tendons are traditionally repaired under either general anaesthesia (GA) or regional anaesthesia (RA), allowing for the use of an arm tourniquet to minimise blood loss and establish a bloodless surgical field. However, the use of tourniquets exposes the patient to certain risks, including skin, muscle and nerve injuries. A recent advancement in anaesthesia delivery involves the use of a wide-awake approach where no sedation nor tourniquets are used (wide-awake local anaesthesia no tourniquet (WALANT)). WALANT uses local anaesthetic with epinephrine to provide pain relief and vasoconstriction, reducing operative bleeding. Several studies revealed potential benefits for WALANT compared with GA or RA. However, there remains a paucity of high-quality evidence to support the use of WALANT. As a result of this uncertainty, the clinical practice varies considerably. We aim to evaluate the feasibility of WALANT as an alternative to GA and RA in patients undergoing surgical repair of flexor tendon injuries. This involves addressing factors such as clinician and patient support for a trial, clinical equipoise, trial recruitment and dropout and the most relevant outcomes measures for a future definitive trial.

METHODS AND ANALYSIS

WAFER is a multicentre, single-blinded, parallel group, randomised controlled trial (RCT) to assess the feasibility of WALANT versus RA and GA. The target population is patients with acute traumatic flexor tendon injuries, across 3 major hand surgery units in England involving a total of 60 participants. Outcome assessors will be blinded. The primary outcome will be the ability to recruit patients into the trial, while secondary outcomes include difference in functional outcome, patient-reported outcome measures, health-related quality of life, cost-effectiveness and complication rates.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the London-City and East Research Ethics Committee (22/PR/1197). Findings will be disseminated through peer-reviewed publication, conferences, patient information websites and social media networks.

TRIAL REGISTRATION NUMBER

ISRCTN identifier: 15052559.

Flexor Tendon Repair: Avoidance and Management of Complications

The proper technique for flexor tendon repair has been well established through numerous bench science and clinical studies. However, less is known about strategies to avoid and manage postoperative complications. This article discusses the common complications after flexor tendon repair, such as repair site rupture and adhesion formation. This article also addresses strategies to prevent and manage these complications. The foundation for preventing many of these complications is ensuring a strong repair without gapping at time zero, which will enable the accrual of tensile strength through early initiation of motion.

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

BACKGROUND

Flexor tendon lacerations in the fingers are challenging injuries that can be repaired using the wide-awake local anesthesia no tourniquet (WALANT) technique or under traditional anesthesia (TA). The purpose of our study was to compare the functional outcomes and complication rates of patients undergoing flexor tendon repair under WALANT versus TA.

METHODS

All patients who underwent a primary flexor tendon repair in zone I and II without tendon graft for closed avulsions or open lacerations between 2015 and 2019 were identified. Electronic medical records were reviewed to record and compare patient demographics, range of motion, functional outcomes, complications, and reoperations.

RESULTS

Sixty-five zone I (N = 21) or II (N = 44) flexor tendon repairs were included in the final analysis: 23 WALANT and 42 TA. There were no statistical differences in mean age, length of follow-up, proportion of injured digits, or zone of injury between the groups. The final Quick Disabilities of the Arm, Shoulder, and Hand score in the WALANT group was 17.2 (SD: 14.4) versus 23.3 (SD: 18.5) in the TA group. There were no statistical differences between the groups with any final range of motion (ROM) parameters, grip strength, or Visual Analog Scale pain scores at the final follow-up. The WALANT group was found to have a slightly higher reoperation rate (26.1% vs 7.1%; P = .034) than the TA group.

CONCLUSIONS

This study represents one of the first clinical studies reporting outcomes of flexor tendon repairs performed under WALANT. Overall, we found no difference in rupture rates, ROM, and functional outcomes following zone I and II flexor tendon repairs when performed under WALANT versus TA.

Ulnar Superficialis Slip Resection Versus Radial Superficialis Slip Resection: A Biomechanical Pilot Study

BACKGROUND

There are numerous clinical scenarios during which the surgeon contemplates whether the radial or ulnar slip of the flexor digitorum superficialis (FDS) should be sacrificed. To date no study has assessed the point of failure of each one of the FDS slips in each digit, aiding the avid surgeon in deciding which slip to sacrifice.

METHODS

A total of 41 digits were assessed, each digit was dissected, and a specimen containing the denuded bone of the middle phalanx with the attachments of the ulnar and radial FDS slips was obtained. An Instron 4502 device was utilized to biomechanically assess the point of failure of each slip of each digit.

RESULTS

There was no statistical difference between ulnar and radial slip point of failure when compared across all digits and subjects. There was no statistical difference between male and female subject's specimens. The point of failure was higher in the ulnar slips of the second and third digits, whereas the point of failure was higher in the radial slips of the fourth and fifth digits.

CONCLUSIONS

Sacrifice of a FDS slip may cause loss of grip strength. In several clinical scenarios one may be faced with the dilemma which FDS slip to sacrifice. Our findings show this is not an arbitrary choice. Hand surgeons should keep our findings in mind when deciding which slip to sacrifice, in effort to preserve function and strength in the injured hand.

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.

Medium-term clinical outcomes of Zone 2B/2C finger flexor tendon repairs: influence of management of flexor digitorum superficialis

III.

Hand therapy role in return to work for patients with hand and upper limb conditions

STUDY DESIGN

Electronic Web-based survey INTRODUCTION: Evidence supports the use of health-focused interventions combined with service coordination and work modification components to reduce the individual, community, and societal burden associated with acute and chronic musculoskeletal conditions. The levels of engagement, skill, and confidence of Australian hand therapists in assisting their patients to return to work (RTW) are currently unknown.

PURPOSE OF THE STUDY

To identify current practices, skill, and the need for additional training in management of the RTW process from a sample of Australian hand therapists.

METHODS

An electronic survey was sent to current members of the Australian Hand Therapy Association. Data collected included training and/or professional experience, caseload and/or workplace, scope of and barriers to vocational practice, and satisfaction with own contribution to the RTW process for patients.

RESULTS

A total of 99 individual responses (12.4% of total membership) were included, with most indicating a limited role in the RTW process. Only 52.7% said they regularly monitored and adjusted their patients' RTW program. Most plans were informed by formal tests of underlying body structure and function components rather than the patient's ability to perform of a specific work role or task. Median satisfaction with the quality of RTW service they provided was 6 of 10, with 42% scoring ≤ 5 of 10, indicating considerable scope for improvement.

CONCLUSIONS

Practice patterns are described for planning and monitoring RTW, and these did not always align with the evidence-base. Further exploration of clinician barriers to implementing RTW interventions is warranted, as is upskilling for those indicating a lack of confidence in this field.

The consistency and reliability of six-strand and four-strand flexor tendon repairs: a comparative porcine cadaveric study

The aim of this study was to compare the consistency and reliability of the six-strand Gan modification of the Lim-Tsai flexor tendon repair with the four-strand Adelaide repair, both with 3-0 sutures and with eight to ten runs of simple 5-0 running peripheral suture as well as the influence of the surgeons' level of experience on the strength of the repair in a cadaveric animal setup. Thirty-nine surgeons repaired 78 porcine flexor digitorum profundus tendons with either the Adelaide technique (39 tendons) or the modified Lim-Tsai technique (39 tendons). Each repaired tendon was tested in a material testing machine under a single cycle load-to-failure test. The forces were recorded when the gap between the two tendon stumps reached 1 and 2 mm and when irreversible elongation or total rupture occurred. We found no significant differences in gap formation force and yielding strength of the tendons between the two methods. The surgeon's previous experience in tendon repairs did not improve the consistency, reliability or tensile strength of the repairs. We conclude that if a strong peripheral suture is added, the modified Lim-Tsai repair has the same technical reliability and consistency as the Adelaide repair in term of ultimate loading strength in this test setup.

Dynamic Tendon Grip (DTG™) novel knot array compared to traditional sutures for zone two flexor tendon injury - a biomechanical feasibility study

BACKGROUND

Flexor tendon injuries pose many challenges for the treating surgeon, the principal of which is creating a strong enough repair to allow early active motion, preserving a low-profile of the repair to prevent buckling and subsequent pulley venting. A main concern is that a low-profile repair is prone to gap formation and repair failure. The Dynamic Tendon Grip (DTG™) all suture staple device claims to allow a strong and low-profile repair of the flexor tendon. The purpose of this study is to test the effects of the DTG™ device in early active motion simulation on range of motion, load to failure and gap formation and to compare it to traditional suturing technique.

METHODS

Twelve fresh-frozen cadaveric fingers were assigned to two groups: DTG™ device (n = 9) and traditional suturing (double Kessler 4-core suture and a peripheral suture, n = 3). The deep flexor was incised and repaired in zone 2, and active motion simulation was carried out with a cyclic flexion-extension machine. Finger range of motion and gap formation were measured, as well as load to failure and method of repair failure.

RESULTS

Following motion simulation, ROM decreased from 244.0 ± 9.9° to 234.5 ± 5.8° for the DTG™ device compared to 234.67 ± 6.51° to 211.67 ± 10.50° for traditional suturing. The DTG™ repair demonstrated gap formation of 0.93 ± 0.18 mm in 3 of 8 specimens after applying 1 kg load, which negated after load removal. Load to failure averaged 76.51 ± 23.15 N for DTG™ and 66.31 ± 40.22 N for the traditional repair. Repair failure occurred as the suture material broke for the DTG™ array and at the knot level for the traditional repair.

CONCLUSIONS

The DTG™ all-suture stapling concept achieved a strong low-profile repair in zone 2 flexor tendon injury after active motion simulation. Further clinical studies will be needed to determine the effectiveness of this device compared to traditional techniques.

Outcomes at 3 Months of a Place and Active Hold Method of Flexor Tendon Rehabilitation Following Zone II Injury

Background: Previous studies have shown that outcomes following a place and active hold (PAH) are better than a passive flexion protocol after a two-strand core-suture repair of flexor tendons injuries in zone II. This study aims to determine the outcomes of a PAH protocol of flexor tendon rehabilitation following a four-strand core-suture plus an epitendinous suture repair of the flexor digitorum profundus (FDP) combined with a simple horizontal loop repair of the flexor digitorum superficialis (FDS). Methods: This is a prospective study of patients with complete injury to both flexor tendons in zone II. All tendons were repaired with a simple horizontal loop for FDS and four-strand core-suture plus epitendinous suture for FDP. The PAH protocol was used postoperatively for 6 weeks. The outcome was evaluated using flexion contracture and total active motion (TAM), interpreted using Strickland criteria and categorised as excellent, good, fair and poor at 6 weeks and 3 months. The linear regression model was used to determine predictors of outcomes. Results: The study included 32 patients with flexor tendon injury in 46 fingers. No repairs ruptured, and 24 (52%) digits achieved good or excellent motion 6 weeks after surgery using the Strickland criteria. According to the Strickland criteria, 41 (89%) digits ranked as excellent and good with no poor result at a 3-month follow-up. Four patients had 5-10° of flexion contracture. Age was the predictor of TAM at 6 weeks and accounted for 13% of its variation. Improvement of TAM from 6 weeks to 3 months was related to age and flexion contracture at 6 weeks. Conclusions: The PAH protocol can be considered a safe technique for flexor rehabilitation after four-strand core-suture repair of FDP in zone II. Level of Evidence: Level IV (Therapeutic).

Postoperative hand therapy management of zones V and VI extensor tendon repairs of the fingers: An international inquiry of current practice

STUDY DESIGN

Electronic Web-based survey.

INTRODUCTION

Evidence supports early motion over immobilization for postoperative extensor tendon repair management. Various early motion programs and orthoses are used, with no single approach recognized as superior. It remains unknown if and how early motion is used by hand therapists worldwide.

PURPOSE OF THE STUDY

The purpose of this study was to determine if there is a preferred approach and identify practice patterns for constituents of International Federation of Societies for Hand Therapy full-member countries.

METHODS

Participation in this English-language survey required respondents to have postoperatively managed at least one extensor tendon repair within the previous year. Approaches surveyed included programs of immobilization, early passive (EPM), and early active (EAM) with motion delivered by resting hand, dynamic, palmar/interphalangeal joints (IPJs) free, or relative motion extension (RME) orthoses. Survey flow depended on the respondent's answer to their "most used" approach in the previous year.

RESULTS

There were 992 individual responses from 28 International Federation of Societies for Hand Therapy member countries including 887 eligible responses with an 81% completion rate. The order of most used program was EAM (83%), EPM (8%), and immobilization (7%). The two most used orthoses for delivery of EAM were RME (43%) and palmar/IPJs free (25%). The RME orthosis was preferred for earlier recovery of hand function and motion. Barriers to therapists wanting to use the RME/EAM approach related to preference of surgeon (70%) and clinic (24%).

DISCUSSION

In practice, many therapists select from multiple approaches to manage zone V and VI extensor tendon repairs. Therapists believed TAM achieved with the RME/EAM approach was superior to the other approaches. Contrary to the literature, in practice, many therapists modify forearm-based palmar/IPJs free orthosis to exclude the wrist to manage this diagnosis.

CONCLUSIONS

The RME/EAM approach was identified as the favored approach. Practice patterns and evidence did not always align.

Relative motion extension management of zones V and VI extensor tendon repairs: Does international practice align with the current evidence?

STUDY DESIGN

Electronic Web-based survey.

INTRODUCTION

Therapists participating in an international survey selected relative motion extension (RME) as the "most used" approach for the postoperative management of zones V and VI extensor tendon repairs. A subgroup of respondents identified RME as their preferred approach and were asked about their routine RME practices.

PURPOSE OF THE STUDY

The purpose of this study was to capture data from routine RME users about their practices and compare this with the RME evidence.

METHODS

An English-language survey was distributed to 36 International Federation of Societies for Hand Therapy full-member countries. Participation required therapists to have postsurgically managed at least one extensor tendon repair within the previous year. Those who selected RME as their "most used" approach were asked to identify which variation of the RME approach they favored: RME plus (with wrist orthosis), RME only, or "both" RME plus and RME only, and then were directed to additional questions related to their choice.

RESULTS

Respondents from 28 International Federation of Societies for Hand Therapy full-member countries completed the survey. RME users (N = 368; 41.5% of sample) contributed to this secondary data. Respondents favored the RME variation "RME plus" (47%), followed by "both" (44%), then "RME only" (9%) with most managing single digit/simple injuries (n = 287, 81%) versus multiple digit/complex injuries (n = 96, 27%), and partial repairs (n = 278, 79%).

DISCUSSION

Practices not aligning with limited level II-IV evidence includes half of RME only users not adding/substituting an overnight orthosis; use of RME plus versus RME only for both repairs of independent extensor tendons and repairs proximal to the juncturae tendinum; fabrication of three not four-finger orthotic design; and restricting use to only repairs of one or two fingers.

CONCLUSIONS

RME plus and RME only are used interchangeably depending on surgeon preferences and patient/tendon factors. Compared with RME plus, from this survey, it appears that the RME only approach yields similar uncomplicated, early return of motion and hand function.

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.

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.

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

PURPOSE

Our hypothesis was that the rupture rate after primary flexor tendon repair in the modified 4-strand core suture technique using the FiberLoop^® (Arthrex, Munich, Germany) is lower than in other suture materials and functional outcome and patient satisfaction are superior compared to the current literature.

PATIENTS AND METHODS

A 2-stage retrospective, randomized follow-up study of 143 patients treated with the Arthrex FiberLoop^® after flexor tendon injury in zones 2 or 3 from May 2013 to May 2017 was performed. In the 1^st stage, the rupture rate of all patients was assessed after a follow-up of at least one year by interview to exclude revision surgery. In the 2nd stage, 20% of the patients could be randomly clinically examined. Functional parameters, such as finger and wrist range of motion measured by goniometer, grip strength measured by Jamar dynamometer (Saehan, South Korea), patient satisfaction measured by school grades (1-6), pain levels measured by visual rating scales (0-10) and functional outcome according to the DASH-score were assessed. The Buck-Gramcko and Strickland scores were calculated. The length of sick leave was recorded.

RESULTS

A rupture rate of 2.1% was recorded. 29 patients (20%) were followed up at a mean of 34 ± 7.5 months postoperatively. 10.3% of these patients had an incomplete fingertip palm distance. The mean postoperative grip strength was 24 ± 3.1 kg. 93% of the patients were very satisfied with the treatment. No patient complained of pain postoperatively. The mean postoperative DASH score was 6.7 ± 2.8 points. The mean Buck-Gramcko score was 14 ± 0.2 points. 93% of the patients had excellent and 7% good results according to the Strickland score. 67% of patients had a work accident and returned to work at a mean of 4 ± 0.2 months postoperatively. 31% of patients suffered a non-occupational injury and returned to work at a mean of 3 ± 0.4 months postoperatively.

CONCLUSIONS

Primary flexor tendon repair in the modified 4-strand core suture technique using the Arthrex FiberLoop^® has proven to be a viable treatment option in our series. The rupture rate was lower than in other suture materials. It leads to acceptable pain relief, grip strength and functional outcome.

LEVEL OF EVIDENCE

IV; therapeutic.

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

Objective

This study was designed to compare the ultimate tensile strength and force to 2 mm gap formation among 50% partial, 75% partial, and complete circumferential epitendinous suture with a combination of 4-strand core suture in human cadaver flexor tendon.

Materials and methods

Forty-five flexor tendons from four soft human cadavers were used to evaluate the biomechanical property among 50% partial, 75% partial, and complete circumferential epitendinous suture with a combination of 4-strand core suture.

Results

The force to 2 mm gap of complete epitendinous was significantly greater than partial epitendinous suture (P < 0.05); however, there was no difference between 50% partial and 75% partial epitendinous suture (P > 0.05). For the ultimate strength, there was no significant difference between partial and complete epitendinous suture (P > 0.05). The partial epitendinous was approximately 60% of the complete epitendinous suture in force to 2 mm gap and also 70% of complete epitendinous suture in ultimate tensile strength with a combination of core sutures.

Conclusions

The complete epitendinous suture showed better ultimate tensile strength and force to 2 mm gap compared with a partial 50% and 75% epitendinous suture. However, in some clinical scenario which the complete epitendinous suture is not possible to perform, the authors suggested only partial epitendinous suture with 50% circumference is recommended as the additional epitendinous repair up 75% circumference cannot provide any mechanical benefit to the repaired site.

Comparative Accuracy of 1.5T MRI, 3T MRI, and Static Ultrasound in Diagnosis of Small Gaps in Repaired Flexor Tendons: A Cadaveric Study

PURPOSE

We hypothesized that magnetic resonance imaging (MRI) would more accurately diagnose small gaps (<6 mm) after flexor tendon repair than static ultrasound (US) and that suture artifact would negatively impair accuracy.

METHODS

A laceration of the flexor digitorum profundus was created in 160 fresh-frozen cadaveric digits and randomized to either an intact repair (0-mm gap) or repairs using a locked 4-strand suture repair with either 4-0 Prolene, Ethibond, or and gaps of 2, 4,or 6 mm; or no suture in which 2-, 4-, or 6-mm gaps were created without a suture crossing the repair site. We performed 1.5T and 3T MRI and static US studies; gap widths were estimated by radiologists blinded to suture presence and true gap widths.

RESULTS

The 1.5 and 3.0T MRI had a lower mean error than US for gap sizes 0 and 2 mm. All 3 modalities performed similarly for 4- and 6-mm gaps. Documentation of imaging artifact worsened error, and odds of seeing artifacts were 1.72 higher with MRI than with US. Suture did not worsen artifact nor impair accuracy for any of the 3 modalities. When no suture was used, all 3 modalities significantly overestimated the true gap.

CONCLUSIONS

MRI is most accurate for small gaps less than 4 mm. Although all modalities overestimated gap sizes in specimens with a 0-mm gap (intact tendon repair), mean overestimation (<2 mm) was not clinically relevant. Ultrasound overestimated 2-mm gaps (clinically intact repairs), whereas MRIs did not. We recommend MRI for evaluation of gaps after flexor tendon repair. The 1.5T has slightly better sensitivity and specificity for distinguishing clinically intact (gap < 3 mm) from clinically impaired (gap > 3 mm) repairs than the 3T.

CLINICAL RELEVANCE

Accurate diagnosis of intact repairs or small gaps (<3 mm) might prevent unnecessary exploration or allow modification of rehabilitation protocols. Diagnosis of clinically relevant gaps (3-6 mm) may allow for earlier revision surgery before significant tendon retraction and adhesions develop, possibly necessitating a staged reconstruction.

Comparative Sensitivity and Specificity of Static and Dynamic High-Resolution Ultrasound in Diagnosis of Small Gaps in Repaired Flexor Tendons: A Cadaveric Study

PURPOSE

To compare the sensitivity and specificity of high-resolution static and dynamic ultrasound (US) for diagnosing intact repairs and small, clinically relevant gaps (≥4 mm) in repaired flexor digitorum profundus tendons within zone 2 and, secondarily, to evaluate the effect of suture artifact from 3 commonly used suture types.

METHODS

Eighty-eight fresh-frozen cadaveric digits (thumbs excluded) were randomized to either an intact repair (0-mm gap) or repairs using a locked 4-strand suture repair with either 4-0 Prolene, Ethibond, or FiberWire and gaps of 2, 4, or 6 mm and no suture in which 2-, 4-, or 6-mm gaps were created without a suture crossing the repair site. Gap widths were estimated by a blinded musculoskeletal ultrasonographer in static and dynamic modes.

RESULTS

Both static and dynamic modalities tended to overestimate actual gap sizes. For the suture gaps, both modalities had poor sensitivity (29% static; 42% dynamic) for accurately diagnosing a clinically intact repair (<4 mm), but better specificity (83% static; 75% dynamic) for diagnosing a clinically failed repair (≥4-mm gap). Although suture presence decreased the sensitivity of gap width measurement for both modalities, no differences were seen between suture types.

CONCLUSIONS

Static and dynamic US have poor sensitivity for diagnosing clinically intact repairs (gaps < 4 mm) because they typically overestimate gap size. The ability to diagnose failed repairs (gap ≥ 4 mm), based on greater specificity, is much better, but still suboptimal.

CLINICAL RELEVANCE

Based on a receiver operating characteristic analysis cutoff of 5 mm, if a gap of 5 mm or larger is identified with US when evaluating a zone 2 flexor digitorum profundus tendon repair, a failed repair is likely in about 80% of cases. A gap measurement of less than 5 mm may miss a high percentage of repairs that are clinically failed.

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.

Wide-Awake Surgery With Local Anesthesia and Epinephrine Is Safe

Hand and upper extremity surgery performed with the patient wide awake involves the use of a local anesthetic and epinephrine. Controversy persists as to whether epinephrine is safe for use in the hand. The goal of this study was to evaluate the safety of epinephrine in hand and upper extremity surgery. The hypothesis was that epinephrine is safe and can be used for a wide breadth of surgical procedures of the hand and upper extremity. A 4-year retrospective chart review was conducted of consecutive patients undergoing wide-awake surgery performed by 2 surgeons at a single institution. All procedures were performed with local anesthesia and epinephrine. Data collected included patient demographics, procedure volume, procedure type, surgical setting, and complications related to epinephrine use. During the study period, 4054 consecutive patients underwent 4287 wide-awake procedures with local anesthesia and epinephrine. Average patient age was 59 years, and 64% of patients were female. No complications occurred as a result of the use of epinephrine, and no tissue necrosis, phentolamine reversal, anaphylaxis, or readmissions occurred. No patients required conversion to general anesthesia or monitored anesthesia care. This analysis of more than 4000 consecutive patients undergoing wide-awake hand and upper extremity surgery with epinephrine confirmed that epinephrine use is safe, with no reported cases of tissue necrosis, reversal, readmission, anaphylaxis, or anesthetic conversion. Epinephrine is safe for use in the hand and upper extremity for patients undergoing wide-awake hand surgery with a local anesthetic. [Orthopedics. 2020;43(6):e529-e532.].

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.

Improving Strength and Quality of Epitendinous Repairs

Background: Epitendinous sutures not only join the 2 severed tendon edges but also supply strength and support to the repair. Multiple techniques have been described, but none of them include another thread of suture. This could potentially increase the strength of the repair without affecting gliding. Methods: Caprine tendons were harvested, transected, and sutured with 6-0 Prolene. Four groups were created: single thread running (SR), single thread locking (SL), double thread running (DR), and double thread locking (DL). An Instron 5542 was used to pull the repaired tendons apart, and the energy at the break was calculated (gf/mm). For gliding resistance, we harvested a human A2 pulley. A pre- and postrepair value was obtained, and a ratio was elaborated. A single-factor analysis of variance and independent sample t tests were performed. Results: The SR group had a mean energy at break of 9339.71 ± 1630.212 gf/mm; the SL group, 9629.96 ± 1476.45 gf/mm; and the DR group, 9600.221 ± 976.087 gf/mm, with no statistical significance. The DL group was significantly higher at 14 740.664 ± 2596.586 gf/mm (P < .05). When comparing SR with DL for gliding, SR had less than half of the resistance than DL (0.018 ± 0.004 and 0.049 ± 0.015 N/mm, respectively), with statistical significance (P < .05). Conclusion: Using a single suture thread for running epitendinous repair is no different than locking with a single thread or using an extra thread in a running fashion. Performing a double suture thread with a locking technique is significantly stronger than the previously mentioned repairs, with the disadvantage of more resistance at the pulley.

Current Trends in WALANT Surgery: A Survey of American Society for Surgery of the Hand Members

Purpose

To define self-reported WALANT use among American Society for Surgery of the Hand (ASSH) members. We aimed to define surgeon and practice demographics relative to WALANT use and identify potential barriers for WALANT implementation.

Methods

An anonymous multiple-choice survey was electronically distributed to all active ASSH members. Incomplete surveys were included in the final analysis. Surgeons were asked to provide reasons for not performing WALANT, which were categorized based on general themes. We compared practice and surgeon demographic information relative to WALANT use.

Results

Of 3,826 ASSH members, 869 responded (23%). A total of 79% of respondents had performed at least one WALANT procedure; 62% currently incorporated WALANT into their practice. Hospital-owned outpatient surgery centers were the most common location for WALANT procedures (31%). Canadian surgeons were more likely to use WALANT, compared with US and international surgeons. Surgeons with fewer years in practice and higher-volume surgeons were more likely to use WALANT. There was no statistically significant association between either practice or income structure and WALANT use. For carpal tunnel release (CTR), 13% did not offer patients WALANT, whereas 43% offered WALANT to all patients. Moreover, 51% of surgeons reported that anesthesia staff was required to be present for WALANT cases at their institution. In determining reasons for not using WALANT, 16% reported that they preferred a tourniquet for visualization. Only 2% had concerns regarding epinephrine use in the hand.

Conclusions

The results of this survey illustrate current WALANT use among ASSH members and defines the demographics of those employing WALANT. Lack of familiarity with WALANT and an acceptance of the use of epinephrine in the hand has increased from prior ASSH surveys. Lack of familiarity with the technique, concerns regarding operating room efficiency, and patient preferences remain considerable barriers to more widespread adoption of WALANT procedures.

Type of study/level of evidence

Economic and Decision Analysis V.

Ordinary PVC feeding tube: A low-cost alternative to silicon rod for staged flexor tendon reconstruction in zone II of hand

BACKGROUND

Staged flexor tendon reconstruction is most appropriate treatment for delayed zone II flexor tendon injuries of hand. The Hunter's silicon rod used in this procedure is costly and not simply available. The aim of this study was to evaluate the results using PVC feeding tube as a cheaper and readily available alternative.

MATERIALS AND METHODS

this study include 6 patients(8 digits) were treated by the staged flexor tendon reconstruction using PVC feeding tube for first stage followed by tendon graft in second stage and the patients were followed for mean period of 6 months.

RESULTS

Excellent results were seen in 5 digits and good results in 3 digits, according to both LaSalle system and Strickland-Glogovac grading system.

CONCLUSIONS

PVC feeding tube is a cost effective, simply accessible and an effective alternative to Hunter's silicon rod for staged flexor tendon reconstruction.

Flexor Subzone II A-D Range of Motion Progression during Healing on a No-Splint, No-Tenodesis Protection, Immediate Full Composite Extension Regimen

Background: The objective was to study the hypotheses that an advanced zone II flexor tendon rehabilitation protocol would avoid rupture, achieve a high range of excursion, and minimize interphalangeal contracture during both the early phases and at the conclusion of healing. We also proposed the null hypothesis of no difference between any two of the zone II subdivisions. Methods: Fifty-one consecutive adult patients with zone II flexor tendon repairs of a single finger were retrospectively evaluated on an active contraction rehabilitation protocol with no splint, no tenodesis protection, and immediate full composite extension. There were 38 males and 13 females with a mean age of 39 years (range 18-69) involving 15 index, 7 long, 6 ring, and 23 small fingers. Repairs were located in flexor subzone IIA for 8 fingers; subzone IIB, 14; subzone IIC, 19; and subzone IID, 10. Differences in outcome between any two subzones were compared by T-test with p < 0.05. Results: Mean active arcs of motion in degrees at 3 weeks post repair were PIP 1-93; DIP 0-44; and total active motion (TAM) 221. At 6 weeks PIP 2-98; DIP 1-51; and TAM 236. At 10-12 weeks PIP 1-101; DIP 1-56; and TAM 246. Final TAM by flexor subzone IIA was 243; IIB, 251; IIC, 246; and IID, 246. There were no significant differences between any two subzones. Mean final DASH score was 5. There were no ruptures. Conclusions: The results support the hypotheses. Outcomes of the therapy protocol demonstrated the lack of interphalangeal joint flexion contractures, high range of total active motion achieved early and sustained, and no ruptures. No differences were identified between and two of the flexor subzones.

Comparison of surgical trends in zone 2 flexor tendon repair between Turkish and international surgeons

Objectives

The aim of this study was to evaluate Turkish trends in zone 2 flexor repair with regards to surgical technique, suture materials, anesthesia and post-operative rehabilitation and compare this with international surgeons by modifying Gibson's survey.

Methods

A printed and online survey consisting of 19 questions modified from Gibson's survey was sent to 590 Turkish and international surgeons. The surgeon's years in practice, province of practice, residency type, number of zone 2 flexor tendon repairs done in a year, preferred surgical technique, suture material, complications and postoperative protocols were asked to the respondents.

Results

A total of 194 surgeons completed the survey (a 25% response rate). Of those who completed the survey, 91 were international (mostly from far eastern countries) and 103 were Turkish surgeons. Years in practice and educational background had influence on the decision-making. There were differences between the Turkish and international surgeons in the core and epitendinous suture thickness preference and flexor tendon sheath repair. There was a statistically significant relationship between the province of practice and the use of WALANT (Wide awake local anesthesia no tourniquet) (p < 0.05). While the majority of respondents who preferred postoperative early passive motion protocol were from Turkey (61.5%), the majority of respondents who preferred early active motion protocol were practicing abroad (73.9%).

Conclusion

Despite some variations the surgeons involved in this study follow to a large extent the current literature.

Negative Predictors of Outcomes of Flexor Tendon Repairs

The current trend in hand surgery has streamlined the treatment of acute hand trauma to the modern-day surgery unit. As the volume of hand trauma caseloads continues to increase, it is becoming increasingly difficult to schedule patients for theater on the day of injury. It, therefore, becomes paramount to adequately triage patients in accordance with best clinical evidence and predictors of poor clinical outcomes.

Animal models suggest that the earlier flexor tendons are repaired, the better the patient functional outcome. The largest study to date examining the timing of injury to functional post-operative outcome also recognizes that the faster these injuries are repaired, the better the patient outcome. Age-related changes to tendon biomechanics and structure are well-documented. However, no conclusive evidence exists specific to the degenerative changes and mechanical properties of flexor tendons in humans. The animal model strongly suggests that increasing age is associated with local architectural and biological changes that directly affect the tendon repair functional outcome. Although retrospective analyses to date suggest that smoking is a negative outcome predictor for functional tendon outcome, no prospective large-scale studies exist.

A large, single-center prospective study specifically examining the positive and negative outcome predictors of flexor tendon repairs and functional post-operative outcome is warranted. The negative predictive model of patient care may enable us to further council patients preoperatively and stratify patients according to clinical need.

Latest Advances in Wide Awake Hand Surgery

Injection of tumescent local anesthesia should no longer be painful. WALANT anesthesia, strong sutures, a slightly bulky repair, intraoperative testing of active movement, and judicious venting of the A2 and A4 pulleys improve results in flexor tendon repair. WALANT K wire finger fracture reduction permits intraoperative testing of K wire stability with active movement to facilitate early protected movement at 3 to 5 days after surgery. WALANT can decrease costs and garbage production while increasing accessibility and affordability. Several surgeons have found no infection difference when the K wires are inserted with full operating room sterility versus field sterility.

Lessons Learned in the Authors' First Years of Wide-Awake Hand Surgery at the W Hospital in Korea

Wide-awake local anesthesia no tourniquet (WALANT) is a promising development for surgeons and patients through improved operation outcomes in hand and wrist surgery. The authors have mostly used WALANT for flexor and extensor tendon repair, tenolysis, and tendon transfer. Its application at W Hospital in korea has bolstered surgeon confidence in tendon repair integrity, gliding ability, and transfer tension via direct observation and patient feedback. The authors do not use WALANT in complicated tenolysis or in secondary surgeries in previous severe injury situations. The procedure has proven similarly unsuitable in incomplete or complete digit replantation.

Practice in Wide-Awake Hand Surgery: Differences Between United Kingdom and Cyprus

The implementation of the wide-awake local anesthetic no tourniquet (WALANT) approach to surgical procedures in Cyprus has led to significant cost savings. In the United Kingdom, the implementation of WALANT has led to shorter waiting times for hand surgical procedures, cost savings for the National Health Service, and high patient satisfaction rates. In both countries, patient education is a prerequisite for WALANT surgery. It increases the satisfaction rate among patients and enhances the patient-surgeon relationship. Patients need to know they can participate actively in a procedure, because a patient moving the hand during a procedure can improve the outcome.

Results of 4-strand modified Kessler core suture and epitendinous interlocking suture followed by modified Kleinert protocol for flexor tendon repairs in Zone 2

Objective

There has been no consensus in literature for the ideal flexor tendon repair technique. The results of zone 2 flexor tendon lacerations repaired primarily by 4 strand Modified Kessler core suture and epitendinous interlocking suture technique followed by Modified Kleinert protocol were investigated.

Methods

128 fingers of 89 patients who had flexor tendon laceration in zone 2 built the working group. Functional outcomes were evaluated using the Strickland formula. A statistical analysis was made between Strickland scores and some parameters such as age, gender, follow-up time, co-existing injury existence, repair time, single or multiple finger injury, tendon rupture and the effect of FDS injury and repair.

Results

Excellent, good, fair, poor results were obtained from 71 (55.5%), 46 (35.9%), 8 (6.3%), 3 (2.3%) fingers, respectively. Time of the repair has a significant effect on the strickland scores. Surgery performed within the first 24 hours following the injury gave better results. 3 fingers (2.3%) had tendon ruptures. Existence of ruptures affected the results significantly. Co-existing injuries were found that they did not have any effect on the results. In the fingers in which both FDP and FDS tendons were lacerated, no significant relationship was found between only FDP repair, both FDP and FDS repair and single FDS slip repair. Additionally no significant relationships between follow-up time, gender, single or multiple finger injury and Strickland scores were observed. 13 fingers (10.1%) had PIP joint contracture above 20°.

Conclusion

The low rupture rate (2.3%) and 91.4% ‘good’ and ‘excellent’ scoring rates in our series support the idea that modified Kessler 4-strand core suture and epitendinous interlocking suture repair combined with modified Kleinert protocol gives satisfactory results. Repair time is one of the most important factors affecting the functional results and surgery should not be delayed if there is an experienced surgeon available.

Level of evidence

Level IV, therapeutic study.

Primary flexor tendons repair in zone 2: Current trends with GEMMSOR survey results

The repair of flexor tendon lesions in zone 2 remains a highly controversial subject in hand surgery. Currently, there is no consensus about the management of these lesions intra- and postoperatively, but the literature suggests that a solid suture will allow early active motion. We hypothesized that the management of flexor tendon injury in zone 2 varies widely. Two online surveys were conducted with surgeons and hand therapists. The questions captured the demographics of the surveyed population, surgical technique, common complications, postoperative management (duration of immobilization, type of splint, rehabilitation techniques and principles of self-rehabilitation). The responses were compared to current literature data. We collected 366 responses to the "surgery" survey and 206 responses to "rehabilitation" survey. Most surgeons performed suture repair with at least 4 strands (75.9%). Active rehabilitation protocols were used in 48.9% of cases. The "rehabilitation" survey underlined the lack of information provided to therapists by surgeons. Therapists used active protocols in 79.7% of cases. This study found a large variation in the management of flexor tendon injuries, which is not always consistent with current published recommendations. Ideally, the suture repair should be a 4-strand pattern with an epitendinous circumferential suture and a release of the pulley in the suture area. Mobilization and rehabilitation should be started on the 3rd day using an active protocol.

In Vitro Comparison of Two Barbed Suture Configurations for Flexor Tendon Repair

Purpose  The current study compares the strength of a previously studied technique for flexor tendon repair with barbed sutures to an experimental approach that aligns all the barbs to oppose distraction. Methods  Twelve flexor tendons from cadaveric specimens were mechanically tested following repair of simulated zone II tendon injuries. Two repair techniques utilizing barbed sutures were studied: the Marrero-Amadeo four-core barbed suture approach and the experimental configuration with all barbs on four cores opposing distraction. Maximum applied load at failure, that is, ultimate load, and 2-mm gap force were compared between the two repair techniques, both as raw values and after normalization to cross-sectional area of the intact tendon. Statistical testing was performed using t -tests and Mann-Whitney U -tests, where appropriate, with a significance level of 0.05. Results  The ultimate loads, raw (58.2 N) and normalized (4.8 N/mm ² ), were significantly larger for the Marrero-Amadeo repair than the proposed experimental approach (35.6 N and 2.7 N/mm ² ; p  < 0.05). No significant differences were identified for 2-mm gap force. Conclusion  The innovation of suturing to align all barbs to oppose distraction does not improve strength of the repaired tendon. The Marrero-Amadeo technique was found to have superior strength for use in traumatic zone II flexor tendon injuries.