Single-Stage Flexor Tendon Grafting: Refining the Steps

Diagnosis and treatment of flexor tendon injuries of the hand: what the radiologist needs to know

This article reviews the diagnosis and treatment of flexor tendon injuries of the hand highlighting flexor tendon anatomy, important pre-operative imaging findings, surgical options, and post-operative complications. Imaging plays a key role in guiding treatment of these difficult to manage injuries. Thus, it is important for radiologists to have a sound understanding of factors important in treatment decision-making. In the pre-operative setting, accurately identifying the location of the torn proximal tendon stump in subacute and chronic injuries helps dictate whether the patient is a candidate for a primary flexor tendon repair or may require a tendon reconstruction to restore function. In the post-operative setting, the status of the repair and presence of surrounding adhesions help dictate if and when the patient will require subsequent surgery and whether that surgery will be a tenolysis, revision repair, reconstruction, or fusion.

How Can We Make Hand Surgery Carbon Neutral?

BACKGROUND

Climate change is a major public health threat worldwide. Operating theaters are responsible for extensive waste production due to the resource-intensive nature of surgery, including hand surgery.

METHODS

An online literature search was performed to ascertain the approaches that surgeons may undertake to positively impact the environment.

RESULTS

Surgeons can make hand surgery more carbon neutral through various measures that have been categorized as pre-, intra-, and postoperative interventions. With all changes, the aims are to minimize waste and costs while optimizing patient outcomes.

CONCLUSIONS

Administrative obstacles to implementing pro-climate hospital changes may be overcome by also considering likely cost benefits with many environmentally friendly measures. New measures in hand surgery should consider patient safety, clinical efficacy, cost effectiveness, and the environmental impact.

Flexor Tendon Reconstruction

Chronic injury to the flexor tendon system of the hand remains a challenging problem for the hand surgeon to treat. Both single- and two-stage techniques remain important in the reconstruction of the flexor tendon deficient digit. Modern advances include the use of allograft composites that aim to reduce the time and donor-site morbidity compared with conventional autograft techniques. Regardless of technique, restoring a gliding tendon-pulley system with a functional arc of motion is the primary goal of flexor tendon reconstruction.

Mini-open one-stage flexor digitorum profundus tendon graft for jersey finger under WALANT with ultrasound assistance: a case report of a new technique

Treatment of the late presentation of a jersey finger is a therapeutic challenge. We describe a novel technique of one-stage mini-open reconstruction of avulsed flexor digitorum profundus (FDP) using a palmaris longus tendon graft under WALANT with ultrasound assistance. The graft was passed inside the digital sheath using a compressive tendon guide under ultrasound control, to avoid a large surgical approach. WALANT enabled intraoperative setting of tendon graft tension, with restored tendon gliding in the sheath. Ultrasound-guided active rehabilitation was initiated immediately postoperatively in the surgeon's office.

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.

Flexor Tendon Grafting Using Extrasynovial Tendons Followed by Early Active Mobilization

Purpose

This study evaluated the outcomes of early active mobilization after flexor tendon grafts using extrasynovial tendons with a novel distal fixation technique.

Methods

This study was a retrospective case series. The flexor digitorum profundus (FDP) tendons of 7 digits in 7 patients were reconstructed with extrasynovial tendons, which included the palmaris longs, plantaris, and extensor digitorum longus, in a single- or 2-stage procedure between 2008 and 2017. Of the 7 patients, 6 were male and the average patient age was 48 years. The injuries involved 2 middle, 2 ring, and 3 little fingers. The tendons were sutured into the appropriate FDP tendon proximally using end-weave anastomosis; the distal end of the graft was fixed to the distal stump of the FDP using an interlacing suture or a small bone anchor combined with the pull-through technique. The digits were mobilized with a combination of active extension and passive and active flexion in a protective orthosis during the first 6 weeks after surgery. Average follow-up was 18 months. We measured active and passive digit motion both before tendon grafting and at the final evaluation. Outcomes were graded by the LaSalle formula to assess staged flexor tendon reconstruction.

Results

Average passive range of motion (ROM) of the proximal and distal interphalangeal joints before flexor tendon grafting was 146° (SD, 22°). Mean active ROM of these joints at the final evaluation was 123° (SD, 34°). Using the LaSalle formula, mean recovery of active motion was 83%. We encountered no grafted tendon rupture and no finger required tenolysis.

Conclusions

Our proximal and distal fixation techniques allowed the autologous extrasynovial tendon grafts to withstand the stress encountered during early active mobilization with good postoperative ROM and minimal complications.

Type of study/level of evidence

Therapeutic I.

Biomechanical study comparing Pulvertaft suture to step-cut suture

Tendon grafts are a component of the therapeutic arsenal for managing chronic flexor tendons injuries in the hand, especially during two-stage Hunter reconstruction. The purpose of this anatomical study was to compare the strength of the Pulvertaft weave versus the step-cut suture used for flexor tendon reconstruction to determine their role in early active mobilization. We performed a biomechanical study with cadaver specimens. Thirty-four hands were randomized and the tendons from both hands were equally assigned to each group. A comparison of the Pulvertaft weave (group 1) versus the step-cut suture (group 2) using the flexor digitorum profundus from the fourth finger and the longus palmaris was carried out. The main variable was the failure load in both repair groups. We also evaluated the cross-sectional area (CSA) and the tensile strength of the repairs. Thirty hands were included in our study. There was no significant difference in the failure load between the two groups (116N for group 1 versus 103N for group 2, P=0.2). The CSA was significantly smaller in the step-cut group compared to Pulvertaft group (19.8mm² versus 35mm², P<0.01). The tensile strength was significantly higher in the step-cut group than in the Pulvertaft group (5.3N/mm² versus 3.4N/mm², P<0.01). Early active mobilization requires a minimum repair strength of 75N. In our study, the step-cut suture appears strong enough and thin enough to decrease the fibrosis, which would lead to better functional results. No other study of this type has been published. The specimens in which the repair strength was less than 75N all involved a thin, weak longus palmaris. Other biomechanical studies should be done to define the anatomical criteria required for use of the palmaris longus tendon. The step-cut suture seems to be strong enough and thin enough to provide sufficient proximal attachment during flexor tendon reconstruction to allow early active mobilization.

The Relationships Between Surface Measurements and Underlying Tendon Autograft Length for Upper Extremity Reconstructive Surgery

PURPOSE

The availability of tendon grafts is an important consideration for successful upper extremity reconstructive surgery, including flexor or extensor tendon reconstructions, tendon transfers, and ligament reconstructions. Graft selection is based on availability, expendability, ease of harvest, and length. Given variations in patient height and extremity length, existing average values may provide suboptimal insight into actual tendon lengths available. The purpose of this study is, therefore, to pursue a method of estimating available donor tendon lengths based on easily measured anatomical surface landmarks.

METHODS

Thirty cadaveric upper and lower extremity limbs were dissected and the length of commonly harvested tendon grafts including the palmaris longus, extensor indicis proprius, extensor digiti minimi, plantaris, and second long toe extensor was measured. Surface forearm length (from finger tip to cubital fossa) and surface fibular length (from lateral malleolus to fibular head) were also measured. Correlations between surface measurements and underlying tendon lengths were analyzed, and linear models were generated that predicted tendon length as a function of surface measurements.

RESULTS

Surface measurements were correlated with underlying tendon length (R = 0.46 - 0.66). Linear models could predict tendon lengths based on surface measurements. A ratio of donor tendon length compared with the limb segment measured was established for each tendon and can be applied to estimate donor tendon length. For the upper extremity tendons, the multipliers for the palmaris longus, extensor indicis proprius, and extensor digiti minimi were 0.51, 0.20, and 0.18, respectively. Lower extremity tendon ratios for the plantaris and extensor digitorum longus were 0.69 and 0.60, respectively.

CONCLUSIONS

Although length of available donor tendon can be a limiting variable at the time of surgery, surgeons may be better able to estimate underlying tendon lengths using easily obtained superficial measurements.

CLINICAL RELEVANCE

Information obtained from these cadaveric measurements may aid in preoperative planning in hand and upper extremity surgery.