Improving results of flexor tendon repair and rehabilitation

Insurance Status Predicts Hand Therapy Adherence following Flexor Tendon Repair: A Retrospective Cohort Study

BACKGROUND

Many patients are not adherent to hand therapy rehabilitation following surgical repair of traumatic flexor tendon injuries, which can negatively affect surgical outcomes and long-term hand function. The authors aimed to identify the factors that predict patient nonadherence to hand therapy following flexor tendon repair surgery.

METHODS

This retrospective cohort study included 154 patients who underwent surgical repair of flexor tendon injuries at a level I trauma center between January of 2015 and January of 2020. A manual chart review was performed to collect demographic data, insurance status, injury characteristics, and details of the postoperative course, including health care use.

RESULTS

Factors significantly associated with occupational therapy no-shows included Medicaid insurance (OR, 8.35; 95% CI, 2.91 to 24.0; P < 0.001), self-identified Black race (OR, 7.28; 95% CI, 1.78 to 29.7; P = 0.006), and current cigarette smoker status (OR, 2.69; 95% CI, 1.18 to 6.15; P = 0.019). Patients without insurance attended 73.8% of their occupational therapy visits, and patients with Medicaid attended 72.0% of their visits, rates significantly lower than the rate of those with private insurance (90.7%; P = 0.026 and P = 0.001, respectively). Patients with Medicaid were eight times more likely to seek emergency department care postoperatively than patients with private insurance ( P = 0.002).

CONCLUSIONS

Significant disparities in hand therapy adherence following flexor tendon repair surgery exist between patients with different insurance statuses, races, and tobacco use. Understanding these disparities can help providers identify at-risk patients to improve hand therapy use and postoperative outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

The Effect of Timing Between Traumatic Flexor Tendon Injury of the Hand and Surgical Intervention on Repair Failure Rates

Flexor tendon injuries of the hand, especially in zone II, pose a challenge for hand surgeons because of the region's intricate pulley mechanism and local avascularity, and post-surgical complications such as repair failure are not uncommon. One proposed predictor of outcomes following flexor tendon repair has been timing of surgery from initial injury. However, the effect of the timing of flexor tendon repair on failure rates remains controversial and understudied. The purpose of this study was to compare the failure rates of zone II flexor tendon repairs in patients at various time intervals from onset of injury. A retrospective chart review was conducted using data from hand surgery specialists at our level 1 trauma center from January 1, 2010, through May 31, 2020. This retrospective review included 407 zone II flexor tendon repairs. The primary outcome was failure of repair. Among 407 flexor tendon repairs, there were 12 reported repair failures. The failure rate was 2.9%. In the non-failure group, the mean number of days between the date of injury and the date of surgery was 7±13 days. For the failure group, this value was 14±17 days. Repairs occurring within 14 days had a failure rate of 2.3%, while repairs occurring beyond 14 days had a failure rate of 7.7%. This study demonstrates that there is a benefit to repairing the tendon within a 14-day window, as evidenced by a lower failure rate. More research is required to determine if other complications and overall health of the hand are also improved when a repair is performed in a more expedient manner. [Orthopedics. 2024;47(2):113-117.].

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.

Evaluation of Outcome Measures of Zone V Flexor Tendon Injury: A Systematic Review

Background  Flexor tendon injury zone V is a multicomponent soft tissue injury involving tendons, nerves, and vessels. Outcome assessment of repair thus requires evaluation of the hand as a whole rather than solely evaluating tendon function. The purpose of this Preferred Reporting Items for Systematic Reviews and Meta-Analyses -compliant systematic review was to identify and assess the components of outcome measures used in flexor zone V. Methods  A total of 3,761 studies were retrieved from four databases (PubMed, ProQuest, Cochrane Central, and Google Scholar). These studies were then screened for inclusion using a validated screening form. Fifteen articles fulfilling the eligibility criteria were included in the review. Subsequently, the included studies were assessed for methodological quality using the Joanna Brigg Institute tool. Results  Out of the 15 studies, 11 were case series, 3 were cross-sectional studies, and 1 was a randomized controlled trial. Out of 15 included studies, 13 were of low risk, whereas 2 studies suggested moderate risk when assessed for methodological quality using the Joanna Brigg Institute tool. Eight outcome measures were identified, out of which the most frequently used were Total Active Motion by the American Society for Surgery of Hand (TAM-ASSH) and Noaman's criteria. Our study found that Noaman's criteria assessed sensory-motor function and finger deformity in addition to the range of motion (ROM), which was found to be assessed by all the other outcome measures. Conclusion  We concluded that although Buck-Gramcko criteria is well suited for the ROM evaluation, Noaman's criteria, a recently developed outcome measure used exclusively for combined injuries in zone V, took into consideration the implications of nerve injury along with tendon function. Although being specifically designed for combined injuries of tendons, nerves, and vessels in zone V, there is a lack of usage of Noaman's in the literature. There still exists a lack of a consistent and appropriate choice of outcome measure.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Flexor Tendon Repair Techniques: M-Tang Repair

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

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

STUDY DESIGN

Case report INTRODUCTION: Relative motion flexion (RMF) orthoses are emerging as an option for early active motion (EAM) postoperatively.

PURPOSE OF THE STUDY

To describe the rationale and implementation of an RMF orthosis to manage a patient after partial zone II epitendinous flexor tendon repairs.

METHODS

This case involves a female who sustained partial flexor tendon lacerations to her middle finger in zone II, 60% flexor digitorum superficialis (FDS) and 90% flexor digitorum profundus (FDP). After epitendinous repair she was referred to therapy for EAM with a no orthosis request. The unusual circumstances prompted the therapist, concerned about the risk of tendon rupture to engage in discussion with the surgeon. Following discussion, a decision was made to use an RMF orthosis for controlled EAM to protect the epitendinous zone II FDS and FDP repairs. Outcomes of range of motion (ROM), total active motion (TAM), %TAM, grip, and quickDASH are reported.

RESULTS

Neither the FDP or FDS tendons ruptured, nor were there any joint contractures. "Good" %TAM outcomes were achieved at 12-week postoperatively. Quick DASH scores improved 61 points indicating a clinically meaningful difference of improved function.

DISCUSSION

The lack of a multi-strand core suture repair is unusual in combination with EAM. The positive outcomes reported in this single patient have raised questions about the protective benefit of the RMF orthosis when used with a zone II epitendinous repair of a 90% FDP laceration. Epitendinous repair of a partial (60%) FDS injury, however, is not uncommon and often not repaired at all.

CONCLUSIONS

In this single case report the epitendinous repairs of zone II 90% FDP and 60% FDS with digital nerve involvement were successfully managed with an RMF only orthosis. The use of EAM with an epitendinous repair is in conflict to the current surgical and therapy literature.

Hand Therapy after Flexor and Extensor Tendon Repair: Assessing Predictors of Loss to Follow-up

Postoperative hand therapy (HT) is important for regaining function and preventing complications in patients undergoing tendon repair of the hand and wrist. Loss to follow-up (LTFU) can hinder this process; so we sought to determine factors that predict attrition of these patients.

Methods

Charts were retrospectively reviewed for patients who underwent extensor or flexor tendon repair of the hand, wrist, or forearm between 2014 and 2019. Demographic data, including age, sex, zip code, employment status, education level, and insurance type, were collected, and the rate of LTFU was calculated. Logistic regression was used to analyze factors.

Results

A total of 149 patients were identified and analyzed. The rate of LTFU was 42%. Factors that predicted loss were younger age, male gender, lower educational degree, and a documented psychiatric history. Employment status, insurance type, and distance from the HT center did not predict attrition. The number of HT weeks recommended by the occupational therapist did not differ between those who were lost and those who were not. Lost patients completed, on average, 57% of their suggested HT course.

Conclusions

The current study identified demographic factors associated with attrition in patients undergoing tendon repair of the distal upper extremity. Factors included patients who were younger, male gender, less educated, and had a documented psychiatric history. By identifying factors that predict LTFU, specific strategies can be developed to reduce attrition rates, particularly for at-risk populations, to improve patient care after tendon repair.

Hand wounds: An analysis of topography and related damage to underlying structures

INTRODUCTION

Hand wounds account for 35 to 51% of hand traumas. Damage to underlying anatomical structures depends on the location of the wound. The objective of this study is to describe the topographic distribution of hand wounds allowing for subsequent evaluation of the link between affected surface area and underlying lesion.

METHODS

We retrospectively reviewed the medical records of 1058 patients with a total of 1319 wounds over a period of 2 years. Wound location was described according to the cutaneous projection of IFSSH zones for flexors and extensors. Any associated deep lesions were evaluated. Topographical distribution was modeled graphically using a heat-map. We compared the proportion of underlying lesions between each cutaneous zone. Sub-group analysis for lesions' rate regarding zone groups were performed.

RESULTS

58.9% of wounds were located on the palmar surface and 41.1% on the dorsal surface. 71% of wounds affected only the digits. The index finger was the most affected. The most damaged region was zone 2 for palmar wounds and zone 3 for dorsal wounds. 45.5% of wounds resulted in injury to a significant underlying anatomical structure. This frequency was 36.4% and 58.5% for palmar and dorsal wounds respectively. More than 50% of wounds in palmar zone 5 and dorsal zones 1, 3, 5, 6 and 7 presented at least one lesion. A lesion of major structure was more frequently found in palmar zone 5 (p <0.001). Dorsally, no zone predominated. Subgroup analysis for dorsal wounds revealed that wounds overlying joints had more major lesions including more tendons injuries and more articular violations with zone 3 presenting a rate of 68%.

CONCLUSION

We provided the first graphical representation for the topographical distribution of hand wounds. Dorsal wounds have a higher association with injury to underlying structures. These results generally support surgical exploration of all hand wounds regardless of their location.

LEVEL OF EVIDENCE

IV Study type: Epidemiological study.

10 Hypotheses in Hand Surgery

I have put together 10 topics and labeled them as hypotheses, which outline my preferred practices. The topics relate to questionable nerve compression, double crush syndrome of nerves, motion therapy after surgery, delayed primary tendon repair, proximal pole fracture of the scaphoid, short splint, and indications for postoperative hand elevation. I found no proof whether my preferred methods are better than or inferior to alternative methods that others use. The 10 hypotheses are presented to stimulate thinking, clinical observation, or investigations and highlight several areas of research. Investigation into these hypotheses may avoid unnecessary treatment or improve postsurgical comfort for patients and long-term outcomes of treatment.

Secondary Flexor Tendon Reconstruction: Protocol for a Systematic Review and Meta-Analysis

Introduction:

Flexor tendon injuries of the hand and wrist involve complete or partial severance of the tendon, and primary repair is standard treatment. In cases of significantly delayed presentation, rupture of the repair or segmental tendon loss may require 1- or 2-stage secondary tendon reconstruction where a tendon graft is used. There is a risk of poor functional outcome due to stiffness and reduced range of motion which may affect patient’s employment and activities of daily living. This study seeks to systematically evaluate the current evidence to determine outcomes of secondary flexor tendon reconstruction in terms of functional outcomes, complications, patient-reported outcome measures (PROMS) and costs.

Methods:

This is a PROSPERO registered study protocol for systematic review and meta-analysis of comparative and non-comparative studies. Outcomes of intrasynovial versus extrasynovial tendon grafting and seniority of the surgeon will be analysed in addition to comparing graft weaving at the wrist and palm for both single- and two-stage tendon reconstruction. The primary outcome is functional active range of motion. Secondary outcomes are complications, PROMs and resource use. A comprehensive literature search will be conducted from 2000 to present. All studies involving secondary flexor tendon repairs will be involved, without limitation on language, and will be screened by two independent reviewers. Tools to appraise the quality of study methodology and/or bias will be used (e.g., Cochrane Collaborative Risk of Bias tool) and if feasible, a random effects meta-analysis will be conducted.

Ethics and dissemination:

Ethical approval was not required for this study. The results of this systematic review and meta-analysis will be published in a peer-reviewed journal, and presented at both national and international conferences involving hand surgeons. The data collected will allow patients to be counselled more accurately by clinicians and may suggest areas where further research could be undertaken.

Systematic review registration:

PROSPERO CRD42021296009.

Highlights

The Impact of Social Deprivation and Hand Therapy Attendance on Range of Motion After Flexor Tendon Repair

PURPOSE

To examine the influence of social deprivation and hand therapy attendance on active range of motion (AROM) outcomes following flexor tendon repair.

METHODS

We performed a retrospective analysis of patients who underwent primary zone I-III flexor tendon repair between November 2016 and November 2020. Area deprivation index (ADI) was used to quantify social deprivation. Medical record review determined each patient's demographic characteristics, injury details, total hand therapy visits, and final AROM outcome. Active range of motion was converted to Strickland's percentage for analysis. Spearman correlation and simple and multivariable linear regression models were used to assess relationships between explanatory variables and outcomes.

RESULTS

There were a total of 109 patients, with a mean ADI of 53 and mean therapy attendance of 13 visits. Higher ADI and lower therapy attendance were correlated, and each was associated with significantly decreased Strickland's percentage. In the multivariable model, therapy attendance, ADI, zone 2 injury, and age maintained significant associations with Strickland's percentage.

CONCLUSIONS

Socially deprived patients attend fewer therapy sessions and obtain poorer AROM after flexor tendon repair. Social deprivation is likely to contribute to poor outcomes both by its association with decreased therapy attendance and by other potential pathways that make it difficult for deprived patients to achieve good surgical outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Relative motion flexion splinting for the rehabilitation of flexor tendon repairs: A systematic review

Introduction

Relative motion splinting has been used successfully in the treatment of extensor tendon repairs and has recently been applied in flexor tendon rehabilitation. The purpose of this systematic review was to identify articles reporting use of relative motion flexion (RMF) splinting following flexor tendon repair and to examine indications for use and clinical outcomes.

Methods

Seven medical databases, four trials registries and three grey literature sources were systematically searched and screened against pre-specified eligibility criteria. Screening, data extraction and quality appraisal were independently performed by two reviewers.

Results

A total of 12 studies were identified, of which three met the review eligibility criteria: one retrospective case series; one cadaveric proof of concept study; and one ongoing prospective case series. The type of splint (including metacarpophalangeal joint position and available movement), exercise programme, and zone of tendon injury varied between studies. Both case series presented acceptable range of movement and grip strength outcomes. The prospective series reported one tendon rupture and two tenolysis procedures; the retrospective series reported no tendon ruptures or secondary surgeries.

Discussion

We found limited evidence supporting the use of RMF splinting in the rehabilitation of zones I-III flexor tendon repairs. Further prospective research with larger patient cohorts is required to assess the clinical outcomes, patient reported outcomes and safety of RMF splinting in comparison to other regimes. Application of the relative motion principles to flexor tendon splinting varied across the included studies, and we suggest an operational definition of relative motion in this context.

Identification and Distinction of Tenocytes and Tendon-Derived Stem Cells

Restoring the normal structure and function of injured tendons is one of the biggest challenges in orthopedics and sports medicine department. The discovery of tendon-derived stem cells (TDSCs) provides a novel perspective to treat tendon injuries, which is expected to be an ideal seed cell to promote tendon repair and regeneration. Because of the lack of specific markers, the identification of tenocytes and TDSCs has not been conclusive in the in vitro study of tendons. In addition, the morphology of tendon derived cells is similar, and the comparison and identification of tenocytes and TDSCs are insufficient, which causes some obstacles to the in vitro study of tendon. In this review, the characteristics of tenocytes and TDSCs are summarized and compared based on some existing research results (mainly in terms of biomarkers), and a potential marker selection for identification is suggested. It is of profound significance to further explore the mechanism of biomarkers in vivo and to find more specific markers.

Wide-awake local anaesthesia no tourniquet (WALANT) vs regional or general anaesthesia for flexor tendon repair in adults: protocol for a systematic review and meta-analysis

BACKGROUND

Flexor tendon injuries most commonly occur following a penetrating injury to the hand or wrist. These are challenging injuries and the standard treatment is surgical repair under general or regional anaesthesia. 'Wide-awake' surgery is an emerging technique in hand surgery where a conscious patient is operated on under local anaesthetic. The vasoconstrictive effect of adrenaline (epinephrine) creates a 'bloodless' operating field and a tourniquet is not required. The potential advantages include intra-operative testing of the repair; removal of the risks of general anaesthesia; reduced costs; no aerosol generation from intubation therefore reduced risk of COVID-19 spread to healthcare professionals. The aim of this study will be to systematically evaluate the evidence to determine if wide-awake surgery is superior to general/regional anaesthetic in adults who undergo flexor tendon repair.

METHODS

We designed and registered a study protocol for a systematic review and meta-analysis of comparative and non-comparative studies. The primary outcome will be functional active range of motion. Secondary outcomes will be complications, resource use (operative time) and patient-reported outcome measures. A comprehensive literature search will be conducted (from 1946 to present) in MEDLINE, EMBASE, CINAHL, and Cochrane Library. Grey literature will be identified through Open Grey, dissertation databases and clinical trials registers. All studies on wide-awake surgery for flexor tendon repair will be included. The comparator will be general or regional anaesthesia. No limitations will be imposed on peer review status or language of publication. Two investigators will independently screen all citations, full-text articles and abstract data. Potential conflicts will be resolved through discussion or referral to a third author when necessary. The study methodological quality (or bias) will be appraised using an appropriate tool. If feasible, we will conduct a random effects meta-analysis.

DISCUSSION

This systematic review will summarise the best available evidence and definitively establish if function, complications, cost, or patient-reported outcomes are improved when flexor tendons are repaired using wide-awake technique. It will determine if this novel approach is superior to general or regional anaesthesia. This knowledge will help guide hand surgeons by continuing to improve outcomes from flexor tendon injuries.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020182196.

Growth and Stem Cell Characteristics of Tendon-Derived Cells with Different Initial Seeding Densities: An In Vitro Study in Mouse Flexor Tendon Cells

Tendon stem/progenitor cells (TSPCs) are considered promising seed cells for tendon regeneration. Previous studies reported that a low seeding density favors TSPC growth, whereas a high seeding density favors tenocyte growth. We aimed to distinguish TSPCs from tenocytes by seeding tendon-derived cells at a density gradient. In this study, tendon-derived cells were isolated from flexor digitorum profundus tendons of mice and seeded at the initial densities of 50, 500, 5,000, and 50,000/cm². We found that distinct cell colonies were formed from cells with initial seeding densities of 50 and 500/cm², but colonies were not discernible for cells seeded at 5,000 and 50,000/cm². There was a positive correlation between cell proliferation rate and seeding density, but a negative correlation between cell senescence and seeding density. The cell proliferation rate decreased gradually during serial passages. All cells exhibited restricted differentiation potentials, and expressed stem cell markers and relatively high levels of tenogenic markers without notable differences among cells seeded at different densities. We concluded that a pure population of TSPCs could not be isolated from mouse digital flexor tendons through culturing cells at a density gradient. Cells seeded at low densities had very limited proliferative ability and did not show more prominent stem cell characteristics when compared with cells seeded at high densities.

Flexor Tendon: Development, Healing, Adhesion Formation, and Contributing Growth Factors

Management of flexor tendon injuries of the hand remains a major clinical problem. Even with intricate repair, adhesion formation remains a common complication. Significant progress has been made to better understand the mechanisms of healing and adhesion formation. However, there has been slow progress in the clinical prevention and reversal of flexor tendon adhesions. The goal of this article is to discuss recent literature relating to tendon development, tendon healing, and adhesion formation to identify areas in need of further research. Additional research is needed to understand and compare the molecular, cellular, and genetic mechanisms involved in flexor tendon morphogenesis, postoperative healing, and mechanical loading. Such knowledge is critical to determine how to improve repair outcomes and identify new therapeutic strategies to promote tissue regeneration and prevent adhesion formation.

Outcomes of 200 digital flexor tendon repairs using updated protocols and 30 repairs using an old protocol: experience over 7 years

We reviewed outcomes of 230 flexor tendon repairs in 27 thumbs and 203 fingers in Zone 1 and 2 over 7 years. In 2013, we used a 2-strand modified Kessler method followed by passive motion exercise in repairing flexor digitorum profundus tendon injuries in Zone 2 in 30 fingers; 24 fingers were followed, five (26%) had repair ruptures. Between 2014 and 2017, we used a 4- or 6-strand method to repair 111 flexor digitorum profundus tendons in Zone 2, followed by true early active motion. Two had repair ruptures. Among 101 fingers followed over 6 months, two fingers had tenolysis and 87 (87%) good or excellent outcomes. In 2018 to 2019, we used a 6-strand method to repair 42 flexor digitorum profundus tendons in Zone 2 with out-of-splint early active motion. None had repair ruptures or tenolysis. From 2014 to 2019, 27 flexor pollicis longus tendons were repaired in Zone 1 or 2, and 20 fingers had end-to-end flexor digitorum profundus repairs in Zone 1; none had repair ruptures or tenolysis. We conclude that a strong repair and true active motion are necessary for best outcomes of flexor tendon repairs in the thumb and fingers, and out-of-splint true active motion is safe.

The evidence-base for the management of flexor tendon injuries of the hand: Review

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There is no consensus on the optimal flexor tendon repair technique at each anatomical flexor zone.

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There is paucity of high quality evidence.

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Heterogenous study designs limit inter-study comparisons.

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Patient reported outcome measures are crucial but there is a perennial need for robust disease-specific tools to be utilised.

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.

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.

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.

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.

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

PURPOSE

The repair of zone II flexor tendon injuries is an evolving topic in hand surgery with current literature suggesting the use of a 4-strand repair; 3-0 or 4-0 braided, nonabsorbable sutures; and an epitendinous repair. It was hypothesized that variability would exist within the hand surgeon community in treatment of zone II flexor tendon repairs in surgical material used, surgical technique, and postoperative rehabilitation protocol.

METHODS

An online single-answer multiple-choice survey was distributed to the American Society for Surgery of the Hand members' database. Surgeons were asked questions about demographics, surgical technique, suture type, common complications, postoperative management, and the factor that plays the largest role in guiding their surgical preferences. Responses were compared with current medical evidence.

RESULTS

A total of 410 individuals responded to the survey. In regards to technique, the majority of surgeons reported using a 4-strand repair; with 3-0 or 4-0 core braided, nonabsorbable sutures; and performing an epitendinous repair. Only 20% of surgeons surveyed reported ever using wide-awake local anesthesia, no tourniquet and postoperative protocols were split between early active and early passive rehabilitation. Senior surgeons (≥ 15 years in practice) were more likely than their colleagues to use a 2-strand repair and a passive rehabilitation protocol.

CONCLUSIONS

This study demonstrates that the majority of respondents are performing zone II flexor tendon repairs in accordance with the best currently available evidence, although there is variability with respect to suture material, surgical technique, and rehabilitation protocols.

CLINICAL RELEVANCE

There is still a need for high-quality studies on surgical technique and rehabilitation protocols.

Flexor Tendon Repair Postoperative Rehabilitation: The Saint John Protocol

The Saint John Protocol describes a rehabilitation program of up to half a fist of protected true active finger flexion beginning 3 to 5 days after flexor tendon repair. We no longer use full fist place and hold. We illustrate with film and text the reasons for these changes.

Tissue Engineering of Tendons: A Comparison of Muscle-Derived Cells, Tenocytes, and Dermal Fibroblasts as Cell Sources

BACKGROUND

The rapid development of tendon tissue-engineering technology may offer an alternative graft for reconstruction of severe tendon losses. One critical factor for tendon tissue engineering is the optimization of seed cells. Little is known about the optimal cell source for engineered tendons. The aim of this study was to compare mouse muscle-derived cells, dermal fibroblasts, and tenocytes and determine the optimal cell source for tendon tissue engineering.

METHODS

Mouse muscle-derived cells, dermal fibroblasts, and tenocytes were isolated and cultured in vitro. At passage 1, cellular morphology, cell proliferation, and tenogenic marker expression were evaluated. After seeding on the polyglycolic acid scaffolds for 2 weeks in vitro and 12 weeks in vivo, histologic qualities, ultrastructure, and biomechanical characteristics were evaluated.

RESULTS

Proliferation and cellular morphology were similar for dermal fibroblasts and tenocytes, whereas muscle-derived cells proliferated faster than the other two groups. With regard to the phenotype difference between them, muscle-derived cells and tenocytes shared the gene expression of SCX, TNMD, GDF-8, and Col-I, but with MyoD gene expression only in muscle-derived cells. In contrast to dermal fibroblast and tenocyte constructed tendons, neotendon with muscle-derived cells exhibited better aligned collagen fibers, more mature collagen fibril structure, and stronger mechanical properties, whereas no significant difference in the dermal fibroblast and tenocyte groups was observed.

CONCLUSION

Although dermal fibroblasts are candidates for tendon tissue engineering because they are similar to tenocytes in proliferation and neotendon formation, muscle-derived cells appear to be the most suitable cells for further study and development of engineered tendon.