Rehabilitation following flexor tendon injury in Zone 2: a randomized controlled study

The aim of this study was to compare an early active motion (EAM) regimen to a modified Kleinert passive motion therapy in Zone 2 flexor tendon injuries with regards to range of motion (ROM), grip strength and patient-reported outcome measures (PROMs). Seventy-two patients were included. At 3 months postoperatively, we found no difference in total active motion (TAM) between the EAM and the Kleinert groups (median 195.5°, range 115°-273° versus median 191.5°, range 113°-260°), but a significantly better grip strength (median 76%, range 44%-99% versus median 54%, range 19%-101%; p < 0.0005) in the EAM group. Disabilities of the Arm, Shoulder and Hand (DASH) score as well as patient-reported weakness, cold intolerance and problems in daily activities also favoured the EAM group. At 12 months postoperatively, there was no difference in TAM, grip strength or any of the PROMs used. We conclude that EAM leads to a quicker recovery in terms of grip strength and PROMs, but that both regimens lead to similar results at 12 months.Level of evidence: I.

Patients' experiences of flexor tendon rehabilitation in relation to adherence: a qualitative study

PURPOSE

To explore patients' experiences of early active motion flexor tendon rehabilitation in relation to adherence to restrictions and outcome of rehabilitation.

METHOD

Seventeen patients with a flexor tendon injury in one or several fingers participated in qualitative interviews performed between 74 and 111 days after surgery. Data were analysed using directed content analysis with the Health Belief Model (HBM) as a theoretical framework.

RESULTS

Perceived severity of hand function and susceptibility to loss of hand function affected the participants' behaviour. A higher perceived threat increased motivation to exercise and be cautious in activities. During rehabilitation, the perceived benefits or efficacy of doing exercise and following restrictions were compared to the cost of doing so, leading to adherence or non-adherence behaviour. Perceived self-efficacy was affected by previous knowledge and varied through the rehabilitation period. External factors and interaction with therapists influenced the perception of the severity of the injury and the cost and benefits of adhering to rehabilitation.

CONCLUSION

Patient's perception of the injury, the effectiveness of exercises, context and social support to manage daily life affected adherence to restriction, motivation and commitment to rehabilitation. The HBM as a theoretical framework can be beneficial for understanding factors that influence patients' adherence.Implications for RehabilitationInformation regarding the injury and consequences for the patient should be presented at different time points and in different ways, tailored to the patient.It' is important to aid patients to perceive the small gradual improvements in hand function to create motivation to adhere to exercise.Strategies to reduce the cost of adherence in terms of managing everyday life should be addressed by individually based strategies.Instructions regarding exercise and restrictions should be less complex and consider the patient's individual needs.

Is microsurgical experience essential in Zone II flexor tendon injuries?

OBJECTIVES

This study aims to investigate whether microsurgical experience was necessary for the treatment of Zone II flexor tendon injuries.

PATIENTS AND METHODS

Between October 2018 and October 2021, a total of 73 Zone II flexor tendon injuries in 71 patients (53 males, 18 females; mean age: 39.6±12.1 years; range, 21 to 57 years) who underwent surgical intervention in our center were retrospectively analyzed. All patients in the study had flexor digitorum profundus (FDP) tendon injury. The clinical outcomes of patients with digital artery injury, nerve injury or phalanx fracture accompanying FDP tendon injury were evaluated separately according to the American Society for Surgery of the Hand (ASSH) scores. The scores of multiple injuries accompanying FDP tendon injury in patients with FDP+flexor digitorum superficialis (FDS)+digital nerve injury and FDP+FDS+digital artery+nerve injury were evaluated.

RESULTS

The mean ASSH score was 69.4±28.2 in the group with FDP tendon injury accompanying digital nerve injury and 62.9±19.7 in the group with FDP tendon injury and digital artery injury. The clinical outcomes were significantly lower in patients with digital nerve injury and digital artery injury respectively, compared to patients without accompanying injuries (p=0.029 and p=0.012, respectively). The lowest mean score (45.3±10.2) was in patients with fracture accompanying FDP tendon injury and ASSH score was significantly lower than in patients without fracture (p<0.001).

CONCLUSION

Zone II flexor tendon injuries are frequently accompanied by digital artery or nerve injuries, which usually require microsurgical repair. If left untreated, treatment outcome may be poor. Surgical centers and departments undertaking the treatment of flexor tendon injuries should be able to perform microsurgery.

Revision of Flexor Tendon Repair: Factors Associated With Flexor Tenolysis

BACKGROUND

Tenolysis restores mobility to the flexor tendon through the lysis of adhesions that inhibit and negatively impact functional outcomes following flexor tendon repair. Despite extensive literature on operative techniques and therapy protocols used to minimize adhesion formation, there are limited data examining the association of patient, injury, and postoperative factors with tenolysis. This study aims to: (1) quantify tenolysis rates following flexor tendon repair or reconstruction; and (2) identify patient demographic factors, medical comorbidities, injury characteristics, postoperative diagnoses, and complications associated with tenolysis.

METHODS

PearlDiver was used to identify patients who underwent a flexor tendon repair or reconstruction from 2010 to 2020. Patients were stratified by whether or not flexor tenolysis was performed. Patient demographics, comorbidities, injury characteristics, postoperative diagnoses, and complications were recorded. Logistic regression analysis was used to identify independent risk factors associated with tenolysis.

RESULTS

Database review identified 10 264 patients who underwent either flexor tendon repair or reconstruction, with 612 patients (6.0%) subsequently undergoing tenolysis. Logistic regression analysis determined that vascular injury preceding flexor tendon repair, surgical wound disruption, nerve injury diagnosed postoperatively, postoperative tendon rupture, and need for repeat flexor tendon repair were associated with an increased odds of tenolysis. Patient age, sex, and comorbidities were not associated with performance of tenolysis.

CONCLUSIONS

Although tenolysis rates may differ according to physician and patient preferences, identification of factors associated with tenolysis following flexor tendon repair allows surgeons to risk-stratify patients prior to surgery and help guide postoperative expectations if complications arise.

A Diagnostic Algorithm to Guide Operative Intervention of Zone 5 Flexor Injuries

Background: Given the importance of the neurovascular structures in the volar forearm, accurate diagnosis of zone 5 flexor injuries is critical. Purpose: We sought to test the hypothesis that tendinous injury would be more likely in the distal 50% of the forearm and muscle belly injury would be more likely in the proximal 50% of the forearm. Methods: From December 2015 to December 2016, we conducted a prospective clinical study of patients 18 years and older with zone 5 flexor lacerations. We excluded those with concomitant ipsilateral injuries in flexor zones 1 to 4, multiple lacerations in flexor zone 5, prior neurovascular injuries, crush injuries, patients who underwent operative exploration prior to transfer to our facility, and patients who were unable or unwilling to provide consent. Neurovascular and musculotendinous injuries on physical examination were recorded. All patients underwent operative exploration. Physical examination accuracy and the incidence of musculotendinous and neurovascular injury in the distal 50% of the forearm were compared with the proximal 50% of the forearm. Results: The distal 50% of the forearm (group 1, n = 14) had higher probability of tendon injury (64%), whereas lacerations of the proximal 50% of the forearm (group 2, n = 5) did not result in any tendinous injuries. Rather, all patients in group 2 had muscle belly injuries. There was no difference in the rate of neurovascular injury between groups. Physical examination alone was highly accurate in diagnosing nerve injuries (93%-100%) but less accurate in diagnosing arterial injuries (79%-80%) regardless of the location of injury. Conclusions: Due to the lack of tendinous injuries in proximal zone 5 lacerations, along with the accuracy of physical examination in determining the presence of neurovascular injuries, patients with lacerations in the proximal half of the forearm, without evidence of nerve or arterial injury, can likely be observed in lieu of immediate operative exploration.

Prevention of postoperative adhesions after flexor tendon repair with acellular dermal matrix in Zones III, IV, and V of the hand: A randomized controlled (CONSORT-compliant) trial

BACKGROUND

Various techniques have been attempted for preventing postoperative flexor tendon adhesion, such as modification of suture technique, pharmacological agents, and mechanical barriers. However, there is no evidence of the efficacy of these methods in clinical settings. In this study, we present the long-term outcomes of a randomized prospective study in which acellular dermal matrix (ADM) was used to prevent postoperative adhesions after tendon injury in the hand.

METHODS

From January 2017 to January 2020, all patients with an acute single flexor tendon injury in hand Zones III, IV, or V were candidates. A single-digit, total tendon rupture repaired within 48 hours, from the index finger to the little finger, was included in the study. Patients were randomly allocated to either a control or ADM group. Complications and the range of movements were recorded. Functional outcomes and a patient satisfaction questionnaire were evaluated after 12 months following the tendon repair surgery. The present study is adhered to the CONSORT guidelines.

RESULTS

A total of 25 patients was enrolled in the study: 13 patients in the ADM group and 12 in the control group. According to Buck-Gramcko II criteria, the postoperative functional outcome score was 14.38 ± 1.71 in the ADM group and 13.08 ± 1.82 in the control group (P value = .0485). Patient satisfaction was recorded at 8.38 ± 1.44 in the ADM group and 7.08 ± 1.58 in the control group (P value = .0309), a significant difference. There were no differences in complications between the 2 groups.

CONCLUSION

The beneficial effects of ADM after tendon repair were confirmed by improved postoperative functional outcome at flexor Zones III, IV, and V, preventing peritendinous adhesions and acting effectively as an anti-adhesive barrier.

Impact of Design on Force between Flexor Tendons and Distal Radius Volar Plates

Background  Flexor tendon injury is a rare but serious complication of distal radius volar plating. Purpose  This study aims to determine whether the design of distal radius volar plates impacts the amount of force exerted on the flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) tendons when the plates are placed proximal and distal to the watershed line. Methods  Three commercially available plates were applied to 10 fresh, matched-pair upper extremity specimens. Cyclical loading was applied to the tendons, and the force generated between tendon and plate was measured. Linear mixed effect models were used to evaluate differences in maximum and mean forces by plate position, plate design, and the interaction between position and design. Results  Forces on the tendons differed significantly by position but not plate design. For the FPL tendon, the average maximum force with a plate in Soong's grade 2 was 4.50 (95% confidence interval [CI]: 2.8-7.3) times higher than when the plate was in a Soong's grade 0 placement, and 4.63 (95% CI: 2.82-7.61) times higher for the FDP tendon. While not statistically significant, lower observed force values with thinner plates when plates were placed distal to the watershed line suggest that that plate thickness could also be a critical plate characteristic for distally placed plates. Conclusion  Despite differences in plate design, the main determinant of plate prominence and therefore flexor tendon injury potential is placement in relation to the watershed line. Clinical Relevance  This study may help to guide surgeon implant selection and volar plate design.

Postsurgical Rehabilitation of Flexor Tendon Injuries

Rehabilitation after surgical repair of flexor injuries is a controversial topic. Motion at the repair site decreases risk for adhesions but increases risk for rupture. We review the current concepts behind various rehabilitation protocols based on zone of injury and the evidence behind each.

Isolation and characterization of turkey bone marrow-derived mesenchymal stem cells

Flexor tendon injury is often associated with suboptimal outcomes and results in substantial digit dysfunction. Stem cells have been isolated from several experimental animals for the growing interest and needs of utilizing cell-based therapies. Recently, turkey has been developed as a new large animal model for flexor tendon research. In the present study, we reported the isolation and characterization of bone marrow-derived mesenchymal stem cells (BMSCs) from 8- to 12-month-old heritage-breed turkeys. The isolated cells demonstrated fibroblast-like morphology, clonogenic capacity, and high proliferation rate. These cells were positive for surface antigens CD90, CD105, and CD44, but were negative for CD45. The multipotency of turkey BMSCs was determined by differentiating cells into osteogenic, adipogenic, chondrogenic, and tenogenic lineages. There was upregulated gene expression of tenogenic markers, including mohawk, tenomodulin, and EGR1 as well as increased collagen synthesis in BMP12 induced cells. The successful isolation and verification of bone marrow-derived MSCs from turkey would provide opportunities of studying cell-based therapies and developing new treatments for tendon injuries using this novel preclinical large animal model. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1419-1428, 2019.

Correlations Among Objectively Measured Impairment, Outcome Classification Systems, and Subjectively Perceived Disability After Flexor Tendon Repair

PURPOSE

Any loss of range of motion of the finger after flexor tendon repair is an impairment of function, but to what extent it causes disability is not properly understood. The aim of this study was to assess the correlation between perceived function (disability) and objectively measured loss of function (impairment), to understand what impairments are meaningful to patients.

METHODS

We assessed 49 patients who underwent flexor tendon repair an average of 38 months after repair. We measured the perceived function with the visual analog scale, the 4-step rating scale (poor, fair, good, or excellent), and the Disabilities of the Arm, Shoulder, and Hand (DASH) score. The objective measurement of impairment included active range of motion at each joint, total active motion, grip strength, and 2-point discrimination. We also converted range of motion into 4 categories (poor, fair, good, and excellent) following guidelines from 3 different classification systems (American Society for Surgery of the Hand, Strickland-Glocovac, and revised Strickland). We used Spearman ρ and linear regression to assess the correlation.

RESULTS

Active range of motion at the distal interphalangeal joint had a strong correlation and total active range of motion of the finger joints had a moderate correlation with perceived function measured using the visual analog scale and DASH score. Other measured impairments did not correlate with perceived function. Objective classification categories also did not correlate with the patient's own assessment.

CONCLUSIONS

Our results validate the use of range of motion and the DASH questionnaire in assessing flexor tendon repairs. Classification of angular measurement according to the tested systems does not reflect the patient's perspective; it limits the precision of the measurement and adds little value to the measurement itself.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Incidence of tenolysis and features of adhesions in the digital flexor tendons after multi-strand repair and early active motion

We report seven patients requiring tenolysis after primary or delayed primary flexor tendon repair and early active mobilization out of 148 fingers of 132 consecutive patients with Zone 1 or 2 injuries from 1993 to 2017. Three fingers had Zone 2A, two Zone 2B, and two Zone 2C injuries. Two fingers underwent tenolysis at Week 4 or 6 after repair because of suspected repair rupture. The other five fingers had tenolysis 12 weeks after repair. Adhesions were moderately dense between the flexor digitorum superficialis and profundus tendons or with the pulleys. According to the Strickland and Tang criteria, the outcomes were excellent in one finger, good in four, fair in one, and poor in one. Fingers requiring tenolysis after early active motion were 5% of the 148 fingers so treated. Indications for tenolysis were to achieve a full range of active motion in the patients rated good or improvement of range of active motion of the patients rated poor or fair. Not all of our patients with poor or fair outcomes wanted to have tenolysis. Level of evidence: IV.

The Flexor Pollicis Longus Tendon Does Not Lie Parallel to the Thumb Metacarpal

BACKGROUND

Repair of the flexor pollicis longus (FPL) tendon by tendon retriever can be challenging because of uncertainty of the optimal direction. This study aims to describe the FPL tendon path in the thenar eminence.

METHODS

In 18 hands of 9 cadavers, the angle of the FPL tendon was, after dissection, measured in relation to the axis formed between the metacarpophalangeal (MCP) joint of the thumb and the dorsal carpometacarpal joint (MC1-axis) and the axis formed between the second MCP joint and the distal edge of the trapezium (MC2-axis).

RESULTS

The FPL does not follow the angle of the thumb metacarpal. The FPL runs ulnarly from the MC1-axis at a median of 32.5° in abduction and 30.6° in adduction. In relation to the MC2-axis, it runs at a median of 47.5° in abduction and 25° in adduction.

CONCLUSIONS

The FPL tendon path can be preoperatively marked using: (1) the MC1-axis from which it runs ulnarly approximately at an angle of 30° in both abduction and adduction; or (2) the MC2-axis from which it runs radially at an angle of 47.5° in abduction and at an angle of 25° in adduction. We conclude that the FPL tendon path can be preoperatively marked using these axes and does not parallel the metacarpal axes of the thumb.

Outcomes of flexor tendon repairs in zone 2 subzones with early active mobilization

We report on the outcomes of flexor tendon repair in zone 2 subzones with early active mobilization in 102 fingers in 88 consecutive patients. There were 28, 53, 15, and six fingers with repairs in zones 2A to 2D, respectively. Rupture of the repair occurred in four fingers, all in zone 2B. Excluding those with repair ruptures, the mean total active motion was 230° (range 143°-286°). Evaluated with Tang's criteria, the outcomes were ranked excellent in 39 fingers, good in 46, fair in ten, poor in three, and failure in four. The outcomes in zone 2C were significantly inferior to those in zones 2B and 2D ( p = 0.02). Our results suggest that the tendon laceration in the area covered by the A2 pulley (zone 2C) is the most difficult area to obtain satisfactory active digital motion and tendon repair in zone 2B is the area where the risk of rupture is highest.

LEVEL OF EVIDENCE

IV.

Clinical results of releasing the entire A2 pulley after flexor tendon repair in zone 2C

We report the results of complete release of the entire A2 pulley after zone 2C flexor tendon repair followed by early postoperative active mobilization in seven fingers and their comparisons with 33 fingers with partial A2 pulley release. In seven fingers, release of the entire A2 pulley was necessary to allow free gliding of the repairs in five fingers and complete release of both the A2 and C1 pulleys was necessary in two. No bowstringing was clinically evident in any finger. Two fingers required tenolysis. Using Tang's criteria, the function of two digits was ranked as excellent, four good and one fair; there was no failure. The functional return in these seven fingers was similar with that in 33 fingers with partial A2 pulley release; in these patients only one finger required tenolysis. Our results support the suggestion that release of the entire A2 pulley together with the adjacent C1 pulley does not clinically affect finger motion or cause tendon bowstringing, provided that the other pulleys are left intact.

LEVEL OF EVIDENCE

IV.

Outcomes of release of the entire A4 pulley after flexor tendon repairs in zone 2A followed by early active mobilization

We report the outcomes of repair of the flexor digitorum profundus tendon in zone 2a in 22 fingers. The tendon was repaired with a six-strand repair method and the A4 pulley was completely released. Release of the C2 pulley combined with the A4 pulley was necessary in 12 fingers, nine fingers underwent a complete release of the A3, C2, and A4 pulleys, and one finger underwent a release of the C1, A3, C2, and A4 pulleys. The mean total active motion of the three finger joints was 234° at 5 to 12 months of follow-up. No bowstringing was noted in these fingers. The good and excellent recovery of active digital motion was in 20 (91%) out of 22 fingers according to Strickland's criteria or Tang's criteria. Our results suggest that release of the A3, C2, and A4 pulleys makes the repair surgery easier and does not cause tendon bowstringing.

Clinical outcomes of early active mobilization following flexor tendon repair using the six-strand technique: short- and long-term evaluations

We evaluated the factors influencing outcomes of flexor tendon repair in 112 fingers using a six-strand suture with the Yoshizu #1 technique and early postoperative active mobilization in 101 consecutive patients. A total of 32 fingers had injuries in Zone I, 78 in Zone II, and two in Zone III. The mean follow-up period was 6 months; 16 patients (19 fingers) participated in long-term follow-up of 2 to 16 years. The total active motion was 230° SD 29°; it correlated negatively with age. The total active motion was 231° SD 28° after repair of the lacerated flexor digitorum superficialis tendon, and was 205° SD 37° after excision of the flexor digitorum superficialis tendon ends (p = 0.0093). A total of 19 fingers showed no significant increases in total active motion more than 2 years after surgery. The rupture rate was 5.4% in our patients and related to surgeons' level of expertise. Five out of six ruptured tendons were repaired by inexperienced surgeons. Level of Evidence IV.