Flexor tendon injury, repair and rehabilitation

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.

Apoptotic Body-Rich Media from Tenocytes Enhance Proliferation and Migration of Tenocytes and Bone Marrow Stromal Cells

The intrinsic healing following tendon injury is ideal, in which tendon progenitor cells proliferate and migrate to the injury site to directly bridge or regenerate tendon tissue. However, the mechanism determining why and how those cells are attracted to the injury site for tendon healing is not understood. Since the tenocytes near the injury site go through apoptosis or necrosis following injury, we hypothesized that secretions from injured tenocytes might have biological effects on cell proliferation and migration to enhance tendon healing. Tenocyte apoptosis was induced by 24 h cell starvation. Apoptotic body-rich media (T-ABRM) and apoptotic body-depleted media (T-ABDM) were collected from culture media after centrifuging. Tenocytes and bone marrow-derived stem cells (BMDSCs) were isolated and cultured with the following four media: (1) T-ABRM, (2) T-ABDM, (3) GDF-5, or (4) basal medium with 2% fetal calf serum (FCS). The cell activities and functions were evaluated. Both T-ABRM and T-ABDM treatments significantly stimulated the cell proliferation, migration, and extracellular matrix synthesis for both tenocytes and BMDSCs compared to the control groups (GDF-5 and basal medium). However, cell proliferation, migration, and extracellular matrix production of T-ABRM-treated cells were significantly higher than the T-ABDM, which indicates the apoptotic bodies are critical for cell activities. Our study revealed the possible mechanism of the intrinsic healing of the tendon in which apoptotic bodies, in the process of apoptosis, following tendon injury promote tenocyte and stromal cell proliferation, migration, and production. Future studies should analyze the components of the apoptotic bodies that play this role, and, thus, the targeting of therapeutics can be developed.

Up to five-week delay in primary repair of Zone 2 flexor tendon injuries: outcomes and complications

We report the outcomes of delayed primary repair of flexor tendons in Zone 2 in 31 fingers and thumb (28 patients) averaging 15 days (range 4-37) after injury in 2020. The delay was longer than usual due to the COVID-19 pandemic. The tendons were repaired with a 6-strand core suture (M-Tang method) or a double Tsuge suture and a peripheral suture. This was followed by an early, partial-range, active flexion exercise programme. Adhesions in four digits required tenolysis. These patients were not with longest delay. Outcomes of two improved after tenolysis. The other two patients declined further surgery. One finger flexor tendon ruptured in early active motion. This was re-repaired, and final outcome was good. Overall excellent and good results using the Tang criteria were in 27 out of 31 fingers and thumbs (87%). The time elapsed between the injury and surgery is not an important risk factor for a good outcome, rather it depends on proper surgical methods, the surgeon's experience and early mobilization, properly applied. Adhesions may occur, but they can be managed with tenolysis.Level of evidence: IV.

Rehabilitation following surgery for flexor tendon injuries of the hand

BACKGROUND

Various rehabilitation treatments may be offered following surgery for flexor tendon injuries of the hand. Rehabilitation often includes a combination of an exercise regimen and an orthosis, plus other rehabilitation treatments, usually delivered together. The effectiveness of these interventions remains unclear.

OBJECTIVES

To assess the effects (benefits and harms) of different rehabilitation interventions after surgery for flexor tendon injuries of the hand.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, MEDLINE, Embase, two additional databases and two international trials registries, unrestricted by language. The last date of searches was 11 August 2020. We checked the reference lists of included studies and relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared any postoperative rehabilitation intervention with no intervention, control, placebo, or another postoperative rehabilitation intervention in individuals who have had surgery for flexor tendon injuries of the hand. Trials comparing different mobilisation regimens either with another mobilisation regimen or with a control were the main comparisons of interest. Our main outcomes of interest were patient-reported function, active range of motion of the fingers, and number of participants experiencing an adverse event.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data, assessed risk of bias and assessed the quality of the body of evidence for primary outcomes using the GRADE approach, according to standard Cochrane methodology.

MAIN RESULTS

We included 16 RCTs and one quasi-RCT, with a total of 1108 participants, mainly adults. Overall, the participants were aged between 7 and 72 years, and 74% were male. Studies mainly focused on flexor tendon injuries in zone II. The 17 studies were heterogeneous with respect to the types of rehabilitation treatments provided, intensity, duration of treatment and the treatment setting. Each trial tested one of 14 comparisons, eight of which were of different exercise regimens. The other trials examined the timing of return to unrestricted functional activities after surgery (one study); the use of external devices applied to the participant to facilitate mobilisation, such as an exoskeleton (one study) or continuous passive motion device (one study); modalities such as laser therapy (two studies) or ultrasound therapy (one study); and a motor imagery treatment (one study). No trials tested different types of orthoses; different orthosis wearing regimens, including duration; different timings for commencing mobilisation; different types of scar management; or different timings for commencing strengthening. Trials were generally at high risk of bias for one or more domains, including lack of blinding, incomplete outcome data and selective outcome reporting. Data pooling was limited to tendon rupture data in a three trial comparison. We rated the evidence available for all reported outcomes of all comparisons as very low-certainty evidence, which means that we have very little confidence in the estimates of effect. We present the findings from three exercise regimen comparisons, as these are commonly used in clinical current practice. Early active flexion plus controlled passive exercise regimen versus early controlled passive exercise regimen (modified Kleinert protocol) was compared in one trial of 53 participants with mainly zone II flexor tendon repairs. There is very low-certainty evidence of no clinically important difference between the two groups in patient-rated function or active finger range of motion at 6 or 12 months follow-up. There is very low-certainty evidence of little between-group difference in adverse events: there were 15 overall. All three tendon ruptures underwent secondary surgery. An active exercise regimen versus an immobilisation regimen for three weeks was compared in one trial reporting data for 84 participants with zone II flexor tendon repairs. The trial did not report on self-rated function, on range of movement during three to six months or numbers of participants experiencing adverse events. The very low-certainty evidence for poor (under one-quarter that of normal) range of finger movement at one to three years follow-up means we are uncertain of the finding of zero cases in the active group versus seven cases in the immobilisation regimen. The same uncertainty applies to the finding of little difference between the two groups in adverse events (5 tendon ruptures in the active group versus 10 probable scar adhesion in the immobilisation group) indicated for surgery. Place and hold exercise regimen performed within an orthosis versus a controlled passive regimen using rubber band traction was compared in three heterogeneous trials, which reported data for a maximum of 194 participants, with mainly zone II flexor tendon repairs. The trials did not report on range of movement during three to six months, or numbers of participants experiencing adverse events. There was very low-certainty evidence of no difference in self-rated function using the Disability of the Arm, Shoulder and Hand (DASH) functional assessment between the two groups at six months (one trial) or at 12 months (one trial). There is very low-certainty evidence from one trial of greater active finger range of motion at 12 months after place and hold. Secondary surgery data were not available; however, all seven recorded tendon ruptures would have required surgery. All the evidence for the other five exercise comparisons as well as those of the other six comparisons made by the included studies was incomplete and, where available, of very low-certainty.

AUTHORS' CONCLUSIONS

There is a lack of evidence from RCTs on most of the rehabilitation interventions used following surgery for flexor tendon injuries of the hand. The limited and very low-certainty evidence for all 14 comparisons examined in the 17 included studies means that we have very little confidence in the estimates of effect for all outcomes for which data were available for these comparisons. The dearth of evidence identified in this review points to the urgent need for sufficiently powered RCTs that examine key questions relating to the rehabilitation of these injuries. A consensus approach identifying these and establishing minimum study conduct and reporting criteria will be valuable. Our suggestions for future research are detailed in the review.

Effect of Time to Hand Therapy following Zone II Flexor Tendon Repair

This population-based study aimed to define how time to hand therapy following isolated zone II flexor tendon repairs impacts complications and secondary procedures.

METHODS

Insurance claims from the Truven MarketScan Databases were used to evaluate outcomes after isolated zone II flexor tendon repairs between January 2009 and October 2015. Cohorts differing in time to hand therapy were compared to evaluate the impact on complications, reoperation, and number of therapy sessions. Secondary outcomes analyzed how the number of therapy sessions affected rates of reoperation.

RESULTS

Hand therapy was identified in 82% of patients (N = 2867) following tendon reconstruction. Therapy initiation occurred within 1 week, 1-4 weeks, and after 4 weeks in 56%, 35%, and 9% of patients, respectively. Univariate analysis showed no difference in non-tendinous complications (27%, 30%, 29%; P = 0.29) or tendon rupture rates (13%, 13%, 10%; P = 0.42) within 90 days between cohorts. Multivariable analysis showed no difference in rates of tenolysis (6.3%, 6%, 4.4%; P > 0.01). In the early initiation cohort, >23 hand therapy sessions were associated with the highest rates of tenolysis (19%).

CONCLUSIONS

Despite being a common fear of hand surgeons, early initiation of hand therapy was not associated with increased tendon rupture rates. Although delayed therapy is a concern for tendon scarring, it did not confer a higher risk of tenolysis. Complication rates do not appear to correlate with timing of hand therapy. Therefore, hand surgeons should promote early mobility following isolated flexor tendon injuries given the known functional outcome benefits.

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.

[Early functional passive mobilization of flexor tendon injuries of the hand (zone 2) : Exercise with an exoskeleton compared to physical therapy]

BACKGROUND

These days there are different types of aftercare following flexor tendon injury. Patients in this study received a dynamic Kleinert protocol and additionally two different postoperative treatments. Both treatment groups were compared to each other and results were put into perspective when compared to other treatment options.

METHODS

Sixty-two patients presenting with clean lesions of the two flexor tendons in zone 2 received postoperative treatment with a dynamic Kleinert protocol. Patients were randomly divided into either Group I (physical therapy) or Group II (exoskeleton). Range of motion was assessed after 6, 12 and 18 weeks. In addition, we measured the Strickland score and grip strength at the 18-week follow-up. DASH scores were obtained at weeks 12 and 18.

RESULTS

Regardless of the received postoperative treatment, range of motion was predominantly limited in the proximal interphalangeal and distal interphalangeal joints after 6 weeks. This deficit decreased with time and almost full range of motion was achieved after 18 weeks. Grip strength measured 75% (Group I) and 78% (Group II) of the healthy hand's level. Good functional outcome was observed in the DASH scores after 12 weeks, which improved further, measuring 7.5 (Group I) and 6.8 (Group II) at the 18-week follow-up. We did not see any clinically relevant differences between the two patient groups.

CONCLUSION

Regarding possible reruptures, the Kleinert protocol delivers a safe treatment regime. The possible disadvantage of flexion contractures with the Kleinert protocol was not seen in our measurements. Additional motion exercises using an exoskeleton delivered comparable results to classic physical therapy.

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

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

LEVEL OF EVIDENCE

IV.