Strong Digital Flexor Tendon Repair, Extension-Flexion Test, and Early Active Flexion: Experience in 300 Tendons

Repaired Flexor Tendon Excursion with Half a Fist of True Active Movement Versus Full Fist Place and Hold in the Awake Patient

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Zone 2 flexor tendon repairs using a tensioned strong core suture, sparse peripheral stitches and early active motion: results in 60 fingers

We report the outcomes of zone 2 tendon repairs in 60 fingers using a strong core suture, sparse peripheral stitches and early active motion. From January 2014 to April 2016, we repaired 60 flexor digitorum profundus tendons with a tensioned 4-strand or 6-strand core suture and three to four peripheral stitches. The A2 or A4 pulleys were vented as necessary. Following early active flexion of the repaired tendons, no repairs ruptured and 52/60 (87%) fingers recovered to good or excellent function using the Tang criteria after follow-up of 8-33 months. We conclude that tensioned multi-strand strong core repairs only require sparse peripheral stitches and are safe for early active flexion. Standard peripheral sutures are not necessary. The core sutures should be properly tensioned to prevent gapping at tendon repair site and pulleys should be sufficiently vented to allow tendon motion. Level of evidence: IV.

Flexor tendon repair with a polytetrafluoroethylene (PTFE) suture material

BACKGROUND

There is a consensus that after a flexor tendon repair an aggressive rehabilitation protocol with early active motion can improve functional outcome, provided that the combination of material and suturing technique can meet the higher biomechanic demands. Bearing this in mind we evaluated a polytetrafluoroethylene (PTFE) suture (SERAMON^®, Serag-Wiessner) as a possible material for flexor tendon repair.

MATERIALS AND METHODS

40 flexor tendons were harvested from fresh cadaveric upper extremities. 3-0 and 5-0 strands were used both in the polypropylene (PPL) as well as in the PTFE group. In the first phase of the study, we evaluated knotting properties and mechanical characteristics of the suture materials themselves. In the second phase, a 2-strand Kirchmayr-Kessler suture technique was applied for a core suture of a flexor tendon (n = 16). In the third phase, we performed a tendon repair including an epitendinous running suture with 5-0 PPL or 5-0 PTFE material (n = 22). One way ANOVA tests were performed.

RESULTS

The linear loading strength of single strand knotted PPL 3-0 was 19.87 ± 0.59 N. The linear loading strength of knotted PTFE 3-0 was 32.47 ± 1.67 N. For PPL 3-0 maximum linear strength was achieved with five knots, for PTFE 3-0 with eight knots. When a Kirchmayr-Kessler core-only repair was performed, then in the PPL group the loading strength of the repaired tendon was 30.74 ± 9.77 N. In the PTFE group the loading strength was 23.74 ± 5.6 N (p = 0.10). However, all repairs in the PTFE group failed due to cheese wiring. When a Kirchmayr-Kessler core and epitendinous repair technique was used, then in the PPL group the loading strength of the repaired tendon was 49.90 ± 16.05 N. In the PTFE group the loading strength was 73.41 ± 19.81 N (p = 0.006).

CONCLUSION

PTFE demonstrates superior strength properties in comparison to PPL for flexor tendon repairs. However, standard 2 strand techniques have proved inadequate to bear the higher biomechanic demands.

Latest Advances in Wide Awake Hand Surgery

Injection of tumescent local anesthesia should no longer be painful. WALANT anesthesia, strong sutures, a slightly bulky repair, intraoperative testing of active movement, and judicious venting of the A2 and A4 pulleys improve results in flexor tendon repair. WALANT K wire finger fracture reduction permits intraoperative testing of K wire stability with active movement to facilitate early protected movement at 3 to 5 days after surgery. WALANT can decrease costs and garbage production while increasing accessibility and affordability. Several surgeons have found no infection difference when the K wires are inserted with full operating room sterility versus field sterility.

Practice in Wide-Awake Hand Surgery: Differences Between United Kingdom and Cyprus

The implementation of the wide-awake local anesthetic no tourniquet (WALANT) approach to surgical procedures in Cyprus has led to significant cost savings. In the United Kingdom, the implementation of WALANT has led to shorter waiting times for hand surgical procedures, cost savings for the National Health Service, and high patient satisfaction rates. In both countries, patient education is a prerequisite for WALANT surgery. It increases the satisfaction rate among patients and enhances the patient-surgeon relationship. Patients need to know they can participate actively in a procedure, because a patient moving the hand during a procedure can improve the outcome.

Wide Awake Secondary Tendon Reconstruction

The wide awake anesthesia technique is a useful tool in secondary tendon reconstruction. With active participation of the patient, the tendon repair can be adjusted appropriately to prevent repairs that are too tight or too loose. Areas of tendon scarring or triggering can be identified and released. Other advantages of active participation include reduction of gapping, ensuring adequate strength of repair, and avoiding tendon imbalances. Last, it allows intraoperative patient education and may therefore increase patient satisfaction. This article discusses how the technique can be applied to tenolysis, 2-stage tendon reconstruction, and tendon transfer.

New Developments Are Improving Flexor Tendon Repair

New developments in primary tendon repair in recent decades include stronger core tendon repair techniques, judicious and adequate venting of critical pulleys, followed by a combination of passive and active digital flexion and extension. During repair, core sutures over the tendon should have sufficient suture purchase (no shorter than 0.7 to 1 cm) in each tendon end and must be sufficiently tensioned to resist loosening and gap formation between tendon ends. Slight or even modest bulkiness in the tendon substance at the repair site is not harmful, although marked bulkiness should always be avoided. To expose the tendon ends and reduce restriction to tendon gliding, the longest annular pulley in the fingers (i.e., the A2 pulley) can be vented partially with an incision over its distal or proximal sheath no longer than 1.5 to 2 cm; the annular pulley over the middle phalanx (i.e., the A4 pulley) can be vented entirely. Surgeons have not observed adverse effects on hand function after judicious and limited venting. The digital extension-flexion test to check the quality of the repair during surgery has become increasingly routine. A wide-awake surgical setting allows patient to actively move the digits. After surgery, surgeons and therapists protect patients with a short splint and flexible wrist positioning, and are now moving toward out-of-splint freer early active motion. Improved outcomes have been reported over the past decade with minimal or no rupture during postoperative active motion, along with lower rates of tenolysis.

Recent evolutions in flexor tendon repairs and rehabilitation

This article reviews some recent advancements in repair and rehabilitation of the flexor tendons. These include placing sparse or no peripheral suture when the core suture is strong and sufficiently tensioned, allowing the repair site to be slightly bulky, aggressively releasing the pulleys (including the entire A2 pulley or both the A3 and A4 pulleys when necessary), placing a shorter splint with less restricted wrist positioning, and allowing out-of-splint active motion. The reported outcomes have been favourable with few or no repair ruptures and no function-disturbing tendon bowstringing. These changes favour easier surgeries. The recent reports have cause to re-evaluate long-held guidelines of a non-bulky repair site and the necessity of a standard peripheral suture. Emerging understanding posits that minor clinically noticeable tendon bowstringing does not affect hand function, and that free wrist positioning and out-of-splint motion are safe when strong surgical repairs are used and the pulleys are properly released.

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.

Sonographic study of repair, gapping and tendon bowstringing after primary flexor digitorum profundus repair in zone 2

We report sonographic findings with clinical outcomes after zone 2 flexor digitorum profundus tendon repairs in ten fingers. The tendons underwent a six-strand M-Tang core repair, no circumferential suture, and partial or complete division of the pulleys. Over 12 months after surgery and using ultrasound, we found no gapping at the repair site during finger motion. When the pulleys were divided, there was sonographic evidence of tendon bowstringing, but the bowstringing was minimal. Clinically, we did not find any fingers that displayed tendon bowstringing or had functional loss. With ultrasound examination, the repaired tendons remained enlarged over 12 months. Two patients developed heterotopic ossifications at the repair site without tendon gliding, and these required tenolysis. We conclude that the tendon repair site does not gap when a strong core suture is used in the repair without adding peripheral sutures. There is no notable tendon bowstringing clinically, though the repaired tendons have sonographic evidence of minor bowstringing.

LEVEL OF EVIDENCE

III.

The effect of adding active flexion to modified Kleinert regime on outcomes for zone 1 to 3 flexor tendon repairs. A prospective randomized trial

In a prospective randomized study, we studied whether adding active flexion to a modified Kleinert regime changed outcomes of flexor tendon repairs in zone 1, 2 and 3 in 73 fingers (53 patients). Evaluation included active range of finger motion, grip and pinch strengths. Twelve months after surgery, the increase in range of active finger motion after adding active flexion was insignificant compared with that with the modified Kleinert regime. According to the Strickland criteria, 20 out of 29 fingers had excellent or good recovery after adding active flexion, as did 28 out of 34 fingers with the modified Kleinert regime; we could not detect significant improvement of the good and excellent rate. At 6 months, the pinch strength was significantly higher with the addition of active flexion. We failed to find that adding active finger flexion to the modified Kleinert regime improves the overall long-term results of repairs in zone 1 to 3, though recovery appeared faster, and the good and excellent recovery of zone 2 repairs was 17% greater with the active flexion protocol.

LEVEL OF EVIDENCE

I.

Conceptual origins, current practice, and views of wide awake hand surgery

This article reviews historical background, essential practice principles, and the new emerging area of wide awake hand surgery. It outlines the reasons that wide awake, local anaesthesia, no tourniquet surgery has emerged so quickly in the last 10 years over the world. I explain the origin of the concepts and some of the challenges of getting the technique accepted; in particular, the debunking of the myth of epinephrine danger in the finger. I review the most recent developments in several operations in this rapidly changing field of the tourniquet-free approach. Finally, this review includes speculations on the future of this technique.

Robust thumb flexor tendon repairs with a six-strand M-Tang method, pulley venting, and early active motion

We present the outcomes of flexor pollicis longus tendon repairs in 34 thumbs using a six-strand M-Tang repair with venting of one or two pulleys according to site of tendon laceration. The A2 pulley was vented in all three thumbs with zone 1 injury. In 31 thumbs with zone 2 injuries, the oblique pulley was vented partially or entirely. Twenty-two thumbs had both the A1 and oblique pulleys vented. Six to 46 months post-surgery, 14 thumbs with zone 2 injuries were rated excellent, 13 good, three fair and one failure according to Tang criteria. No tendon ruptures or bowstringing occurred. Fourteen of 34 thumbs had deficits in interphalangeal joint extension averaging 13°. We conclude that venting of one or two pulleys may ensure recovery of thumb function without risking tendon bowstringing and that early active thumb motion is safe with a robust tendon repair.

LEVEL OF EVIDENCE

IV.