Increasingly, much shorter splints are used for protection of the wrist and hand after flexor tendon repair.10,11,21 A short splint extends from either the distal forearm or the wrist to the fingertips; I use a splint from the distal forearm to the fingertips. In addition, exact wrist positions are no longer considered important. The wrist can be in neutral, mild flexion, or mild extension, provided that the patient is comfortable. The splint should be slightly flexed at the metacarpophalangeal joint and be straight beyond the metacarpophalangeal joint, and should extend past the finger or thumb tip. The wrist position for splinting should avoid marked flexion (which will be uncomfortable) or marked extension (which will add unnecessary tension to the repaired tendon).
There is no need to start motion or therapy in the first 3 or 4 days after surgery, which also avoids pain and discomfort.1 From day 4 or 5, at least a few sessions of digital motion exercises are necessary; the exact number of sessions should be decided by the surgeons and therapists according to preferences and the patient’s condition. In each session, to lessen resistance of joint stiffness, full passive finger motion—usually 20 to 40 repetitions—should be performed before active digital flexion. Then, active digital flexion should proceed gradually. In the first 3 to 4 weeks, only one-third to two-thirds of the active motion range should be the goal. Extreme digital active flexion should be avoided, because the tendon has greatly increased resistance to gliding and the repair is more prone to disrupt when the tendon is bent and being pulled (Fig. 6).1,28 In reality, some patients have marked swelling at this time, making full range of active motion difficult. For them, it is not possible to immediately pursue forceful, full active flexion, but full passive finger flexion and extension should always be performed. From the end of week 3 or 4, full range of active flexion is the goal. Patients having difficulty with full active flexion at week 4 or 5 may gradually achieve full flexion in later weeks, but exercise to reduce joint stiffness and prevent extension lag is very important for eventual recovery of active finger flexion.
Out-of-splint active motion is encouraged as the most efficient exercise for decreasing resistance to active motion. A robust tendon repair is strong enough to permit the digit to move out of splint. A number of surgeons obtained excellent outcomes after performing out-of-splint active digital motion after finger flexor tendon repair or flexor pollicis longus tendon repair (Fig. 7).14,16,21 The splint can be discarded entirely at week 6 to 7 depending on the severity of injury. Rehabilitation should continue for at least 8 to 10 weeks (or longer), with the goal of decreasing residual extension lag or achieving full flexion. After flexor pollicis longus repairs, active thumb flexion exercise is similar to that of the fingers, although some details vary.14,16
Venting the pulleys changes the dynamics of gliding of a repaired flexor tendon, and strong repair methods increase repair safety. Because of these measures, practices are evolving: (1) peripheral sutures can be rather sparse or even absent14,21,22; (2) a slightly bulky repair site is fine; (3) sheath closure is no longer considered essential or necessary; and (4) wrist positioning can be flexible, and the wrist may not even need protection. In addition, not repairing the flexor digitorum superficialis tendon (e.g., leaving the retracted flexor digitorum superficialis stump alone without resection or resection of the flexor digitorum superficialis tendon exposed in the surgical field locally) is not detrimental to finger motion.
The timing of surgery is not important if the repair is not delayed too long. Although primary repair is always preferable, delayed primary repair within 1 to 2 weeks after injury gives outcomes quite similar to those of a primary repair. Very delayed primary repair (>3 or 4 weeks after injury) can also be attempted,25 but conservative measures, such as using a very strong repair,25 should be taken; and surgeons should be very experienced, because the intraoperative decision as to whether to proceed with secondary tendon reconstruction requires expert judgment.
Although rupture rates of primary repairs have decreased substantially, ruptures remain a persistent complication. They occur mainly in patients whose surgeons still use a weak core suture, or have not yet updated their knowledge about the keys to performing a repair and early active motion.
Adhesions remain a major complication, and are more frequent than repair ruptures. Significant adhesions need surgical tenolysis 6 months after the repair or 3 months after failure to improve active range of motion. Severe soft-tissue and bone injuries or local tissue loss are factors contributing to the formation of adhesions. These complications cannot be avoided entirely with current repair techniques and rehabilitation. Although mild adhesions can be disrupted during passive or active digital motion exercises, severe injury to and edema of the hand cause formation of restrictive adhesions, often requiring tenolysis. There are no recent reports on rates of tenolysis, but they are estimated to be around 10 percent.
Although only some patients need release of joint stiffness, the incidence of joint stiffness is very high. The stiffness improves, although patients often complain of lack of full extension or flexion in the first few months after primary repair. In my experience, unless such lags are severe, it is not necessary to proceed to surgical release. The stiffness usually resolves in 5 to 6 months through daily hand use. The improvement in hand function can be observed for more than 1 year, with major decreases in extension and flexion lags.
The following pitfalls and pearls are very helpful in performing primary flexor tendon repair and rehabilitation:
Based on recent reports and the experience of the author and his colleagues, multistrand repair, especially a six-strand core suture, ensures a strong tendon repair and almost completely prevents repair rupture. Rupture was noted only in rare patients who returned to unrestricted hand use too soon or who suffered accidents. It appears that venting the sheath-pulley a bit longer than previously recommended is not harmful and appears to cause no problems of tendon bowstringing. Although the length limit of the venting apparently varies among fingers and hands of different sizes, the A2 and A4 pulleys should certainly not both be vented. A report from Japan describes venting the entire A2 pulley in some cases.32 Other surgeons vent the A2 pulley according to intraoperative active motion; they do not emphasize keeping it intact.8,29,33 Considerable variations exist in clinical repair configuration; their strengths vary.38 The best practice for pulley venting in the thumb is poorly defined, remaining a topic of discussion.14,16,39
Out-of-splint motion from the very initial weeks is another step toward true active motion. A common impression among many surgeons who use strong repairs and vent the pulleys is that early active motion can be more aggressive than currently recommended. In fact, if a too-forceful grip is avoided, any active motion appears to be safe. I consider that expertise of surgeons should be described together with outcomes,36,40–42 and more aggressive pursuit of tendon motion is likely to become a future direction for research.
1. Tang JBIndications, methods, postoperative motion and outcome evaluation of primary flexor tendon repairs in zone 2. J Hand Surg Eur Vol. 2007;32:118129.
2. Kwai Ben I, Elliot D“Venting” or partial lateral release of the A2 and A4 pulleys after repair of zone 2 flexor tendon injuries. J Hand Surg Br. 1998;23:649654.
3. Elliot D, Giesen TPrimary flexor tendon surgery: The search for a perfect result. Hand Clin. 2013;29:191206.
4. Savage RThe search for the ideal tendon repair in zone 2: Strand number, anchor points and suture thickness. J Hand Surg Eur Vol. 2014;39:2029.
5. Tang JBRelease of the A4 pulley to facilitate zone II flexor tendon repair. J Hand Surg Am. 2014;39:23002307.
6. Tang JB, Chang J, Elliot D, Lalonde DH, Sandow M, Vögelin EIFSSH Flexor Tendon Committee report 2014: From the IFSSH Flexor Tendon Committee (Chairman: Jin Bo Tang). J Hand Surg Eur Vol. 2014;39:107115.
7. Tang JB, Amadio PC, Boyer MI, et al.Current practice of primary flexor tendon repair: A global view. Hand Clin. 2013;29:179189.
8. Higgins A, Lalonde DH, Bell M, McKee D, Lalonde JFAvoiding flexor tendon repair rupture with intraoperative total active movement examination. Plast Reconstr Surg. 2010;126:941945.
9. Lalonde DHWide-awake flexor tendon repair. Plast Reconstr Surg. 2009;123:623625.
10. Wong JK, Peck FImproving results of flexor tendon repair and rehabilitation. Plast Reconstr Surg. 2014;134:913e925e.
11. Khor WS, Langer MF, Wong R, Zhou R, Peck F, Wong JKImproving outcomes in tendon repair: A critical look at the evidence for flexor tendon repair and rehabilitation. Plast Reconstr Surg. 2016;138:1045e1058e.
12. Hoffmann GL, Büchler U, Vögelin EClinical results of flexor tendon repair in zone II using a six-strand double-loop technique compared with a two-strand technique. J Hand Surg Eur Vol. 2008;33:418423.
13. Moriya K, Yoshizu T, Maki Y, Tsubokawa N, Narisawa H, Endo NClinical outcomes of early active mobilization following flexor tendon repair using the six-strand technique: Short- and long-term evaluations. J Hand Surg Eur Vol. 2015;40:250258.
14. Giesen T, Sirotakova M, Copsey AJ, Elliot DFlexor pollicis longus primary repair: Further experience with the Tang technique and controlled active mobilization. J Hand Surg Eur Vol. 2009;34:758761.
15. Zhou X, Li XR, Qing J, Jia XF, Chen JOutcomes of the six-strand M-Tang repair for zone 2 primary flexor tendon repair in 54 fingers. J Hand Surg Eur Vol. 2017;42:462468.
16. Pan ZJ, Qin J, Zhou X, Chen JRobust thumb flexor tendon repairs with a six-strand M-Tang method, pulley venting, and early active motion. J Hand Surg Eur Vol. 2017;42:909914.
17. Moriya K, Yoshizu T, Tsubokawa N, Narisawa H, Hara K, Maki YOutcomes of release of the entire A4 pulley after flexor tendon repairs in zone 2A followed by early active mobilization. J Hand Surg Eur Vol. 2016;41:400405.
18. Sandow MJ, McMahon MActive mobilisation following single cross grasp four-strand flexor tenorrhaphy (Adelaide repair). J Hand Surg Eur Vol. 2011;36:467475.
19. Al-Qattan MMIsolated flexor digitorum profundus tendon injuries in zones IIA and IIB repaired with figure of eight sutures. J Hand Surg Eur Vol. 2011;36:147153.
20. Frueh FS, Kunz VS, Gravestock IJ, et al.Primary flexor tendon repair in zones 1 and 2: Early passive mobilization versus controlled active motion. J Hand Surg Am. 2014;39:13441350.
21. Tang JB, Zhou X, Pan ZJ, Qing J, Gong KT, Chen JStrong digital flexor tendon repair, extension-flexion test, and early active flexion: Experience in 300 tendons. Hand Clin. 2017;33:455463.
22. Giesen T, Calcagni M, Elliot DPrimary flexor tendon repair with early active motion: Experience in Europe. Hand Clin. 2017;33:465472.
23. Rigo IZ, Røkkum MPredictors of outcome after primary flexor tendon repair in zone 1, 2 and 3. J Hand Surg Eur Vol. 2016;41:793801.
24. Edsfeldt S, Rempel D, Kursa K, Diao E, Lattanza LIn vivo flexor tendon forces generated during different rehabilitation exercises. J Hand Surg Eur Vol. 2015;40:705710.
25. Tang JBUncommon methods of flexor tendon and tendon-bone repairs and grafting. Hand Clin. 2013;29:215221.
26. Cao Y, Zhu B, Xie RG, Tang JBInfluence of core suture purchase length on strength of four-strand tendon repairs. J Hand Surg Am. 2006;31:107112.
27. Tang JB, Zhang Y, Cao Y, Xie RGCore suture purchase affects strength of tendon repairs. J Hand Surg Am. 2005;30:12621266.
28. Wu YF, Tang JBRecent developments in flexor tendon repair techniques and factors influencing strength of the tendon repair. J Hand Surg Eur Vol. 2014;39:619.
29. Lalonde DH, Martin ALWide-awake flexor tendon repair and early tendon mobilization in zones 1 and 2. Hand Clin. 2013;29:207213.
30. Tang JBWide-awake primary flexor tendon repair, tenolysis, and tendon transfer. Clin Orthop Surg. 2015;7:275281.
31. Kozono N, Okada T, Takeuchi N, Hanada M, Shimoto T, Iwamoto YAsymmetric six-strand core sutures enhance tendon fatigue strength and the optimal asymmetry. J Hand Surg Eur Vol. 2016;41:802808.
32. Moriya K, Yoshizu T, Tsubokawa N, Narisawa H, Hara K, Maki YClinical results of releasing the entire A2 pulley after flexor tendon repair in zone 2C. J Hand Surg Eur Vol. 2016;41:822828.
33. Elliot D, Lalonde DH, Tang JBCommentaries on clinical results of releasing the entire A2 pulley after flexor tendon repair in zone 2C. K. Moriya, T. Yoshizu, N. Tsubokawa, H. Narisawa, K. Hara and Y. Maki. J Hand Surg Eur. 2016, 41: 822-28. J Hand Surg Eur Vol. 2016;41:829830.
34. Wu YF, Tang JBTendon healing, edema, and resistance to flexor tendon gliding: Clinical implications. Hand Clin. 2013;29:167178.
35. Wu YF, Tang JBEffects of tension across the tendon repair site on tendon gap and ultimate strength. J Hand Surg Am. 2012;37:906912.
36. Tang JBOutcomes and evaluation of flexor tendon repair. Hand Clin. 2013;29:251259.
37. Wu YF, Tang JBThe effect of asymmetric core suture purchase on gap resistance of tendon repair in linear cyclic loading. J Hand Surg Am. 2014;39:910918.
38. Leppänen OV, Linnanmäki L, Havulinna J, Göransson HSuture configurations and biomechanical properties of flexor tendon repairs by 16 hand surgeons in Finland. J Hand Surg Eur Vol. 2016;41:831837.
39. Sirotakova M, Elliot DEarly active mobilization of primary repairs of the flexor pollicis longus tendon with two Kessler two-strand core sutures and a strengthened circumferential suture. J Hand Surg Br. 2004;29:531535.
40. Tang JBRe: Levels of experience of surgeons in clinical studies. J Hand Surg Eur Vol. 2009;34:137138.
41. Tang JB, Giddins GWhy and how to report surgeons’ levels of expertise. J Hand Surg Eur Vol. 2016;41:365366.
42. Moriya K, Yoshizu T, Tsubokawa N, Narisawa H, Matsuzawa S, Maki YOutcomes of flexor tendon repairs in zone 2 subzones with early active mobilization. J Hand Surg Eur Vol. 2017;42:896902.