Postsurgical Rehabilitation of Flexor Tendon Injuries

Cell-based tissue engineered flexor tendon allograft: A canine in vivo study

This study aimed to compare the clinically established autologous extrasynovial tendon graft to a newly developed tissue-engineered allograft (Eng-allograft) in terms of functional outcomes following flexor tendon reconstruction in a canine model. The second and fifth flexor digitorum profundus (FDP) tendons from 16 dogs were transected and repaired in Zone II. After 6 weeks of cage activity, the repaired tendons were intentionally ruptured, creating a clinically relevant model for reconstruction. The re-ruptured FDP tendons were then reconstructed using either the clinically standard autologous extrasynovial tendon graft or the Eng-allograft, which had been revitalized with autologous bone marrow-derived mesenchymal stem cells (BMSCs) and synovialized using carbodiimide derivatized synovial fluid (cd-SYN). Following 12 weeks of postoperative rehabilitation, the functional outcomes of the surgical digits were evaluated. The Eng-allograft group exhibited improved digital function, including lower digit work of flexion and reduced adhesion status, while maintaining similar tendon gliding resistance compared to the autograft group. However, the failure load of both the distal and proximal host/graft conjunctions in the Eng-allograft group was significantly lower than that of the autograft group with higher graft rupture at the host-graft junction. In conclusion, the decellularized allogenic intrasynovial tendon, when revitalized BMSCs and synovialized with cd-SYN, demonstrates positive effects on digital function improvement and adhesion reduction. However, the healing at both proximal and distal graft/host junctions is far lower than the autograft. Further research is needed to enhance the healing capacity of allograft conjunctions, aiming to achieve a comparable level of healing seen with autografts.

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.

Hand Flexor Tendon Repair: From Biology to Surgery and Rehabilitation

Tendon biology and anatomy are crucial to manage hand flexor tendon injuries, not only for surgical treatment but also for rehabilitation; surgeon and physical therapist have to choose zone by zone the best way to manage and restore the normal function of hand flexor tendons.

A 3-Dimensional Suture Technique for Flexor Tendon Repair: A Biomechanical Study

PURPOSE

Flexor tendon injury continues to pose a number of challenges for hand surgeons. Improving mechanical properties of repairs should allow for earlier and unprotected rehabilitation. A 3-dimensional (3D) 4-strand suture technique has been proposed to combine high tensile strength and low gliding resistance without causing suture pullout due to tendon delamination. Our hypothesis is that the 3D technique can result in better mechanical properties than the Adelaide technique.

METHODS

Four groups of 10 porcine flexor tendons were sutured using the 3D or Adelaide technique with a 3-0 polypropylene or ultrahigh molecular weight polyethylene (UHMWPE) suture. The axial traction test to failure was performed on each tendon to measure 2-mm gap force and ultimate tensile strength.

RESULTS

The mean 2-mm gap force was 49 N for group A (3D + polypropylene), 145 N for group B (3D + UHMWPE), 47 N for group C (Adelaide + polypropylene), and 80 N for group D (Adelaide + UHMWPE). Failure mode was caused by suture breakage for group A (10/10) and mainly by suture pullout for the other groups (8/10 up to 10/10). With the UHMWPE suture, the mean ultimate tensile strength was 145 N for the 3D technique and 80 N for the Adelaide technique.

CONCLUSIONS

Porcine flexor tendons repaired using the 3D technique and UHMWPE suture exceeded a 2-mm gap force and tensile strength of 140 N. The ultimate tensile strength was superior to that of the Adelaide technique, regardless of the suture material.

CLINICAL RELEVANCE

This in vitro study on porcine flexor tendon suture highlights that the mechanical properties of 3D repair are better than those of 3D repair using the Adelaide technique when a UHMWPE suture is used.

Risk factors associated with tendon adhesions after hand tendon repair

Background

Tendon adhesions after hand tendon repair are one of the most difficult complications of hand surgery and can cause severe disability. This study aimed to assess the risk factors associated with tendon adhesions after hand tendon repair to provide a theoretical foundation for the early prevention of tendon adhesions in patients with tendon injuries. Moreover, this study intends to increase doctors' awareness of the issue and serves as a reference for developing new prevention and treatment strategies.

Methods

We retrospectively analyzed 1,031 hand trauma cases that underwent repair after finger tendon injury in our department between June 2009 and June 2019. Tendon adhesions, tendon injury zones, and other relevant information were collected, summarized, and analyzed. The significance of data was determined using a t-test or Pearson's chi-square test, and odds ratios (OR) were calculated using logistic regression tests to describe factors associated with post-tendon repair adhesions.

Results

A total of 1,031 patients were enrolled in this study. There were 817 males and 214 females with an average age of 34.98 (2-82) years. The injured side included 530 left and 501 right hands. Postoperative finger tendon adhesions occurred in 118 cases (11.45%), including 98 males and 20 females, 57 left and 61 right hands. The risk factors for the total sample in the descending order were degloving injury, no functional exercise, zone II flexor tendon injury, time from injury to surgery >12 h, combined vascular injury, and multiple tendon injuries. The flexor tendon sample shared the same risk factors as the total sample. Risk factors for the extensor tendon sample were degloving injury, no functional exercise.

Conclusions

Clinicians should pay close attention to patients with tendon trauma in hand having the following risk factors: degloving injury, zone II flexor tendon injury, lack of functional exercise, time from injury to surgery >12 h, combined vascular injury, and multiple tendon injuries. Due to the high risk of post-repair adhesions in patients with the conditions mentioned above, individualized treatment measures should be designed for the risk factors, and postoperative functional exercise of the hand is required.

Effect of a Text Message-Based Support Program on Outcomes of Patients After Flexor Tendon Injury Repair

PURPOSE

Although the effectiveness of using text messages in home-based rehabilitation programs has been investigated, its ability to engage patients in home rehabilitation exercises and, as a result, improve hand outcomes, specifically in patients with flexor tendon injuries, has not been evaluated. The aim of this study was to determine whether the addition of a text message-based intervention to usual care is effective in improving hand outcomes in patients with flexor tendon injuries after repair.

METHODS

In this 2-arm parallel randomized controlled trial, 40 patients were randomly assigned to either the intervention group (usual care plus the support program) or the control group (usual care only). Intervention included an automated package of instructional text messages containing links to a secure website for instructional rehabilitation videos delivered over 12 weeks. The Quick Disabilities of the Arm, Shoulder, and Hand and visual analog scale for pain scores were assessed at 6 and 12 weeks. Physician-reported grip strength and total active motion were assessed after 12 weeks.

RESULTS

The study was completed by 90% (36 of 40) of the patients who were enrolled. There were statistically significant differences between the 2 groups with respect to Quick Disabilities of the Arm, Shoulder, and Hand and visual analog scale scores at the 6-week and 12-week assessments. In addition, there were statistically significant differences between the 2 groups with respect to total active motion and grip strength at 12 weeks. Finally, a high level of satisfaction with the intervention was reported.

CONCLUSIONS

The text message-based program was associated with improved outcomes over the first 12 weeks after flexor tendon repair.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Effect of electromyographic biofeedback training on functional status in zone I-III flexor tendon injuries: a randomized controlled trial

BACKGROUND

Despite advances in hand therapy and surgery, functional deficits persist after flexor tendon repair especially in zone I-III. This suggests that methods applied may be insufficient. Electromyographic (EMG) biofeedback may provide an effective tendon gliding through visual and auditory feedback.

PURPOSE

The purpose of this study was to investigate the effect of EMG biofeedback training applied in addition to early passive motion protocol on functional status in zone I-III flexor tendon injuries.

METHODS

Patients were randomly assigned into two groups, each consisted of 11 patients. In addition to early passive motion method, EMG biofeedback training was applied in the first group. The second group was followed only with early passive motion protocol. Joint range of motion (ROM), Michigan Hand Outcomes Questionnaire (MHQ) and grip strength were evaluated.

RESULTS

There were no significant differences between the groups in terms of the ROM, MHQ scores and grip strength (p ≥ .087). However, there were clinically important differences in the results of the 12th week ROM (effect size = 0.70), 24th week activity of daily living (ADL) score in MHQ (effect size = 0.68), 12th week gross, tip pinch and lateral grip strength (effect sizes = 0.59, 0.52, 0.81, respectively) and 24th week gross, tip pinch and lateral grip strength (effect sizes = 0.69, 0.73, 0.69, respectively) between the two groups.

CONCLUSIONS

EMG biofeedback training was clinically but not statistically superior to early passive motion method in terms of the effect on functional status.

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

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

Sustained-Release Hydrogel-Based Rhynchophylline Delivery System Improved Injured Tendon Repair

During the injured flexor tendon healing process, tendon tissue is easy to form extremely dense adhesion with the surrounding tissue, which causes the serious influence of hand function recovery. Uncaria is widely used in clinic and its main composition, Rhynchophylline (Rhy), has been reported on its good therapeutic effect, which could effectively inhibit the intra-abdominal adhesion formation. However, the therapeutic effect of Rhy on tendon healing and adhesion formation is still unclear. Due to the short half-life of Rhy, hyaluronic acid (HA) sustained-release system for Rhy delivery was constructed and it could also avoid drug from the undesired loss during the transit. After Rhy delivery system was applied around the injured tendons, adhesion formation, gliding function and healing strength of tendons were evaluated. Our results showed that the gliding excursion and healing strength of repaired tendons were both significantly increased, as well as the adhesion was inhibited. From in vivo experiments, Rhy could be able to increase the expression of Col Ⅰ/Col Ⅲ and helped fibroblasts to ordered organization for tendon tissues. But for adhesion tissues, Rhy promoted the apoptosis and accelerated the degradation of extracellular matrix. In vitro study showed Rhy could help tenocytes stimulated with TGF-β1 to recover to normal cell functions involving cell proliferation and apoptosis level. Through high-throughput sequencing, we found that Rhy was involved in the regulation of Extracellular Matrix (ECM) signaling pathway. We draw a conclusion that Rhy enhanced the tendon healing and prevented adhesion formation through inhibiting the phosphorylation of Smad2. In a word, this sustained release system of Rhy may be a promising strategy for the treatment of injured tendons.

[Flexor tendon injuries of the hand]

Flexor tendon injuries of the hand are relatively rare but pose significant challenges to both physician and patient. A thorough clinical evaluation enables flexor tendon lacerations to be identified and classified. The flexor tendons of the hand are divided into five anatomic zones (from distal to proximal). Diagnostics, treatment and prognosis may differ depending on which zone is affected. Early, careful and proficient management is needed to ensure good functional outcomes. Various factors influence the outcome, including location, mechanism of injury, presence of concomitant injuries, time of surgery, quality of tendon repair and the rehabilitation protocol. It is important to inform the patient about the importance of thorough rehabilitation and possible complications. Postoperative scarring and adhesions, infections and secondary tendon ruptures due to insufficient primary repairs are especially challenging and potentially necessitate a lengthy and strenuous secondary repair and rehabilitation process.