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

A randomized controlled trial comparing controlled active motion and early passive mobilization protocols for rehabilitation of repaired flexor tendons in zone II

BACKGROUND

Flexor tendon injuries in zone II of the hand pose serious clinical complications due to the high risk of adhesion formation and suboptimal clinical outcomes, although controlled active motion (CAM) and early passive mobilization (EPM) are standard protocols used during rehabilitation.

OBJECTIVE

This randomized trial compared functional outcomes between CAM and EPM systems after zone II flexor tendon repair.

METHODS

Forty patients with entire zone II flexor digitorum profundus and superficialis tears were randomly assigned to either the CAM or EPM protocol for 12 weeks' rehabilitation. Total active motion (TAM), grip strength, and disability of the arm, shoulder, and hand (DASH) scores were assessed in the 6th and 12th week after the repair. Two-way mixed ANOVA was used to determine the effect of the treatment regarding the type of protocol and time within and between groups, as well as, Cohen's d was used to calculate the effect size.

RESULTS

There was a significant improvement over time in both groups for all measured outcomes (p < 0.001). However, CAM showed superior results than EPM across all time points (6th and 12th week); for TAM (p < 0.05, Cohen's d =11.8 and 9.9), grip strength (p < 0.05, Cohen's d = 7.97 and 9.7), and DASH score (p < 0.05, Cohen's d = 5.8 and 5.5). By 12 weeks, 80% of CAM patients achieved an "excellent" rating according to the Strickland formula of the TAM grading compared with 55% for the EPM group.

CONCLUSION

While both CAM and EPM protocols improve functional status after zone II flexor tendon repair, CAM confers a distinct early advantage in a digital range of motion and manual function compared with EPM. These data support the preferred adoption of the CAM rehabilitation approach after area II flexor tendon surgical repair.

Optimizing Flexor Digitorum Profundus Tendon Repair: A Narrative Review

Zone II flexor digitorum profundus (FDP) tendon injuries are complex, and present significant challenges in hand surgery, due to the need to balance strength and flexibility during repair. Traditional suture techniques often lead to complications such as adhesions or tendon rupture, prompting the exploration of novel strategies to improve outcomes. This review investigates the use of flexor digitorum superficialis (FDS) tendon autografts to reinforce FDP repairs, alongside the integration of biomaterials to enhance mechanical strength without sacrificing FDS tissue. Key biomaterials, including collagen-polycaprolactone (PCL) composites, are evaluated for their biocompatibility, mechanical integrity, and controlled degradation properties. Collagen-PCL emerges as a leading candidate, offering the potential to reduce adhesions and promote tendon healing. Although nanomaterials such as nanofibers and nanoparticles show promise in preventing adhesions and supporting cellular proliferation, their application remains limited by manufacturing challenges. By combining advanced repair techniques with biomaterials like collagen-PCL, this approach aims to improve surgical outcomes and minimize complications. Future research will focus on validating these findings in biological models, assessing tendon healing through imaging, and comparing the cost-effectiveness of biomaterial-enhanced repairs with traditional methods. This review underscores the potential for biomaterial-based approaches to transform FDP tendon repair.

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.

Delayed primary flexor tendon repair in zone II injuries: results of using WALANT and controlled true active motion

Early repair of flexor tendon injuries is ideal, but delays are common. We studied the outcomes of flexor tendon repairs delayed from 5 days to 6 months and carried out under wide-awake local anaesthesia with no tourniquet (WALANT). Twenty-four patients (29 fingers) who underwent primary flexor tendon repair on zone II using a four- to six-strand core suture technique, followed by controlled early active motion therapy. Clinical assessments, including total active motion (TAM) and Disabilities of the Arm, Shoulder and Hand, were made 6, 8 and 12 weeks after operation. All outcomes improved significantly over time. At the final assessment, 93% of fingers showed excellent TAM outcomes. Extension deficit was between 5° and 20° in eight of 26 fingers. The results of this study suggest that delayed primary flexor tendon repair under WALANT can achieve excellent functional outcomes, although longer follow-up is needed for extension deficit recovery.Level of evidence: IV.

Principles for Achieving Predictable Outcomes in Flexor Tendon Repair

Flexor tendon injuries require surgical repair. Early repair is optimal, but staged repair may be indicated for delayed presentations. Zone II flexor tendon injuries are the most difficult to achieve acceptable outcomes and require special attention for appropriate repair. Surgical techniques to repair flexor tendons have evolved over the past several decades and principles include core strand repair using at least a 4 strand technique, epitendinous suture to add strength and gliding properties, and pulley venting. Early postoperative active range of motion within the first 3 to 5 days of surgery is essential for optimizing outcomes.

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.

Segmentary exclusion syndrome in hand traumatology - definition, rehabilitation and orthosis

BACKGROUND

Segmentary exclusion syndrome is a motor behavioral disorder consisting in non-use or underuse of a limb or limb segment following local inflammation, most often of traumatic origin, primarily affecting the fingers and hand. It can be associated with somatosensory disorder, limitation of range of motion, and pain.

PURPOSE OF THE STUDY

The objective of this article is to further describe segmentary exclusion syndrome, and to present practical rehabilitation techniques and strategies focused on prevention, assessment and treatment.

A Lightweight Dynamic Hand Orthosis With Sequential Joint Flexion Movement for Postoperative Rehabilitation of Flexor Tendon Repair Surgery

During the postoperative hand rehabilitation period, it is recommended that the repaired flexor tendons be continuously glided with sufficient tendon excursion and carefully managed protection to prevent adhesion with adjacent tissues. Thus, finger joints should be passively mobilized through a wide range of motion (ROM) with physiotherapy. During passive mobilization, sequential flexion of the metacarpophalangeal (MCP) joint followed by the proximal interphalangeal (PIP) joint is recommended for maximizing tendon excursion. This paper presents a lightweight device for postoperative flexor tendon rehabilitation that uses a single motor to achieve sequential joint flexion movement. The device consists of an orthosis, a cable, and a single motor. The degree of spatial stiffness and cable path of the orthosis were designed to apply a flexion moment to the MCP joint prior to the PIP joint. The device was tested on both healthy individuals and a patient who had undergone flexor tendon repair surgery, and both flexion and extension movement could be achieved with a wide ROM and sequential joint flexion movement using a single motor.

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

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

Therapy after Flexor Tendon Repair

Rehabilitation after flexor tendon repairs is a challenging process. The repaired tendon must be simultaneously protected from disruption and moved in a controlled fashion to prevent restrictive adhesion formation. Although measures are necessary to protect the repaired structures, early controlled motion is required to enhance healing and function. Appropriate intervention at the correct phase of healing is based on an understanding of tendon healing and the factors that influence it. Coordination and communication between the surgeon and therapist is essential. Tendon injuries can profoundly affect hand function, and appropriate rehabilitation is essential to preserve function to the fullest extent possible.

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%.

Relative motion flexion following zone I-III flexor tendon repair: Concepts, evidence and practice

STUDY DESIGN

Narrative review and case series.

INTRODUCTION

The relative motion approach has been applied to rehabilitation following flexor tendon repair. Positioning the affected finger(s) in relatively more metacarpophalangeal joint flexion is hypothesized to reduce the tension through the repaired flexor digitorum profundus by the quadriga effect. It is also hypothesized that altered patterns of co-contraction and co-inhibition may further reduce flexor digitorum profundus tension, and confer protection to flexor digitorum superficialis.

METHODS

We reviewed the existing literature to explore the rationale for using relative motion flexion orthoses as an early active mobilization strategy for patients after zone I-III flexor tendon repairs. We used this approach within our own clinic for the rehabilitation of a series of patients presenting with zone I-II flexor tendon repair. We collected routine clinical and patient reported outcome data.

RESULTS

We report published outcomes of the clinical use of relative motion flexion orthoses with early active motion, implemented as the primary rehabilitation approach after zone I-III flexor digitorum repairs. We also report novel outcome data from 18 patients.

DISCUSSION

We discuss our own experience of using relative motion flexion as a rehabilitation strategy following flexor tendon repair. We explore orthosis fabrication, rehabilitation exercises and functional hand use.

CONCLUSIONS

There is currently limited evidence informing use of relative motion flexion orthoses following flexor tendon repair. We highlight key areas for future research and describe a current pragmatic randomized controlled trial.

The influence of a nanoparticle gel loaded with siRNA-cyclooxygenase on flexor tendon healing: an in vivo animal study

We investigated the influence of cyclooxygenase (COX)-1 and COX-2 siRNAs delivered through a nanoparticle-gel system on the strength of flexor tendon repairs. Sixteen flexor digitorum profundus (FDP) tendons of chicken toes were transected, repaired and wrapped with gels to evaluate gel adherence. We found that the gel adhered to the tendon surface firmly. Next, 56 tendons were used in a first set of in vivo experiments to compare the therapeutic effects of different doses of COX siRNAs. Another 15 tendons were added in a second set to further assess the effects of a dosage of 12 μg. After 4 weeks, the mean strength of the repaired tendons increased most notably in the toes treated with 12 μg COX siRNAs, and the number of samples with low strength (<35 N) was significantly smaller than in the group without molecular treatment. We conclude that COX-1 and COX-2 siRNAs delivered through a nanoparticle-gel system increased the healing strength of the repaired tendons.

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.

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

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

Variation in patient information and rehabilitation regimens after flexor tendon repair in the United Kingdom

Introduction

There is clinical uncertainty regarding the optimal method of rehabilitation following flexor tendon repair. Many splint designs and rehabilitation regimens are reported in the literature; however, there is insufficient evidence to support the use of any one regimen. The aim of this study was to describe rehabilitation guidelines used in the United Kingdom (UK) following zone I/II flexor tendon repair.

Methods

Using a cross-sectional design, hand units in the UK were invited to complete a short survey and to upload their flexor tendon rehabilitation guidelines and patient information material. Approval was granted by the British Association of Hand Therapists. Data were extracted in duplicate, using a pre-piloted form, and analysed using descriptive statistics.

Results

Thirty-five hand units responded (21%), providing 52 treatment guidelines. Three splinting regimens were described, and all involved early active mobilisation: (i) long dorsal-blocking splint (DBS); (ii) short DBS; and (iii) relative motion flexion splint. Duration of full-time splint wear ranged from 4 to 6 weeks. There were variations in splint design and composition of home exercise programmes, particularly for the long DBS. Where reported, recommended return to driving ranged from 8 to 12 weeks, and return to light work activities ranged from 5 to 10 weeks.

Discussion

Treatment guidelines varied across UK hand therapy departments, suggesting that patients receive differing advice about how to protect, move and use their hand after zone I/II flexor tendon repair. The disparity in splint wear duration, home exercise frequency and prescribed functional restrictions raises potential financial and social implications for patients. Future research should explore rehabilitation burden in addition to clinical outcomes.

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

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

Flexor tendon repair: recent changes and current methods

The current clinical methods of flexor tendon repair are remarkably different from those used 20 years ago. This article starts with a review of the current methods, followed by presentation of past experience and current status of six eminent hand surgery units from four continents/regions. Many units are using, or are moving toward using, the recent strong (multi-strand) core suture method together with a simpler peripheral suture. Venting of the critical pulleys over less than 2 cm length is safe and favours functional recovery. These repair and recent motion protocols lead to remarkably more reliable repairs, with over 80% good or excellent outcomes achieved rather consistently after Zone 2 repair along with infrequent need of tenolysis. Despite slight variations in repair methods, they all consider general principles and should be followed. Outcomes of Zone 2 repairs are not dissimilar to those in other zones with very low to zero incidence of rupture.