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Flexor Tendon Repair

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Updated Sep 20264 citations

Why this operation has been suggested

Dr Kieran Hirpara, an upper-limb surgeon at Mater Private Hospital Rockhampton, matches the treatment to your specific injury. Patients are generally referred to our clinic by their GP; if a physiotherapist has suggested you see us, you will still need a referral from your GP in order to be eligible for the Medicare rebate. At your appointment we take a history, examine your hand, and arrange imaging if it is needed. This tells us where the tendon is torn and how bad the injury is.

A flexor tendon is the cord that bends your finger or thumb. When it snaps, it does not heal on its own, so surgery is usually recommended straight away for this kind of injury. The operation stitches the two ends of the tendon back together. The aim is to let you bend the finger or thumb again and to lower the chance of long-term stiffness. We will talk through the plan with you before any decision is made.

Before the operation

Your surgeon will give you clear instructions before the day of surgery, but here is what to expect. You will need to stop eating and drinking for seven hours beforehand. We ask for seven hours rather than six so you can be brought forward if the theatre list runs early. Tell your surgeon about every medicine you take, including blood thinners, as some may need to pause. Bring a written list of your medications on the day. Arrange for someone to drive you home, and wear loose, comfortable clothing with sleeves that slide over your hand. Most people need no special tests beforehand. If you have other medical conditions, you may need blood tests or a review with the anaesthetist.

On the day

You arrive at the hospital's surgical admissions unit, where you are checked in and prepared for theatre. You then meet the anaesthetist. This operation is done under general anaesthetic. A regional nerve block is sometimes added for post-operative pain relief; the anaesthetist will discuss this with you on the day. You are then taken into the operating theatre, where the operation is performed.

You wake up in the recovery area, where nurses monitor you while the anaesthetic wears off. Once you are stable, you either go to the ward or go home, depending on the procedure and your recovery.

What the operation involves

The operation is done through a cut on the palm side of your finger or hand, over the path of the torn tendon. Your surgeon finds the two ends of the tendon and stitches them back together with strong suture thread. Modern repairs use several strands of thread through the tendon, which makes the repair strong enough to start moving within a few days of the injury.

The tendons in your finger slide through narrow tunnels of tissue called pulleys. Your surgeon works carefully around these tunnels and keeps as many of them intact as possible, so the tendon can glide smoothly as it heals. If a tendon end has pulled away and cannot be reached for a direct stitch, or if the repair has failed before, a tendon graft may be used instead. This means taking a piece of tendon from elsewhere and weaving it in to bridge the gap.

The cut is closed with stitches and covered with a dressing. A splint is fitted to protect the repair, and hand therapy begins early. The whole plan, from the timing of surgery to the therapy afterwards, is matched to where the tendon is torn, because injuries in different parts of the finger behave differently and need different care.

The operation itself can be technically demanding, especially when the tear sits inside the finger's narrow sheath. Your surgeon will talk you through the exact plan for your injury before you consent.

After the operation

You will wake up in the recovery area, where nurses watch over you while the anaesthetic wears off. Your hand will be dressed, and a splint will hold your finger or thumb still to protect the repair. Pain relief is planned for you before you leave theatre; tell the nurses if your pain is not settling. You may be asked to keep your hand raised on pillows to help with swelling. Someone should stay with you for the first 24 hours after you get home. Your team will tell you whether you go home the same day or stay one night in hospital.

Recovery

For the first few days your finger or thumb will throb and the hand will swell. Keeping your hand raised on pillows eases this, and your pain relief plan will keep you comfortable. The soreness and swelling settle gradually as the weeks pass.

A splint protects the repair at all times at first. Hand therapy after surgery is with Ruby Doolan at Extend Rehabilitation. Ruby is a hand therapist: she directs your exercises and makes any splint you need. Early on, you will start gentle, careful bending movements of the finger within the splint. Moving the repair site helps the tendon glide and lowers the chance of it sticking down, but moving too much too soon risks the repair pulling apart. Your therapist will show you exactly how far to bend and how often, and you will do these exercises at home several times a day. As healing progresses, the range of movement grows and the exercises become more active.

Everyday tasks take planning while one hand is protected. You will need help with cooking, dressing and washing at first. Sleeping with the splint propped on a pillow can be more comfortable. You should not drive while wearing the splint, and you can read our separate guide on driving after upper-limb surgery.

Recovery varies from person to person. Your timeline may differ, and your surgeon and hand therapist will guide you at each step.

What can go wrong

Most patients do well, but problems can occasionally happen. Your surgeon and the team monitor you closely to spot any issue early.

Sometimes the repaired tendon sticks down to the tissue around it as it heals. You might notice the finger or thumb bending less than expected, or a catching feeling when you try to move it. If bending feels blocked or limited, bring it up at your next review. Your hand therapist can adjust your exercises, and your surgeon can talk through options if the sticking does not settle.

The joints in the finger or thumb can also stiffen into a bent position that does not straighten fully. This is called a joint contracture. You may find you cannot straighten the finger all the way, even with gentle stretching. Tell your therapist or surgeon if straightening becomes harder over time, as early treatment gives the best chance of keeping the joint moving.

The repair itself can pull apart before the tendon has healed. If this happens, you will usually know: the finger or thumb suddenly will not bend at all, or a pop is followed by loss of bending. This is not a slow change, it is a clear loss of movement. If you notice this, contact the clinic straight away or go to the emergency department. A repair that has pulled apart usually needs further surgery.

Injuries in the very tip of the finger, where the tendon attaches closest to the bone, can be harder to treat than tears elsewhere. Full movement is rarely regained with these injuries. If your injury is in this spot, your surgeon will discuss what to expect before you consent.

The complications table on this page lists typical rates if you want the specifics.

When to call us

Call us if you have a fever, or if the wound becomes more red, swollen or starts to ooze fluid. Call us if pain keeps getting worse instead of settling. Go to emergency if you feel short of breath, or if a calf becomes swollen and painful. Go to emergency if your fingers or hand go numb, or if you suddenly cannot bend the finger or thumb after a pop. These changes need checking straight away.

Advanced reading: the deeper science (optional)

This section goes further than you need for your own treatment decisions. Flexor tendon repair is worth the extra reading because it is governed by a single unforgiving trade-off: the movement that stops the tendon sticking down is the same movement that can pull the repair apart. Almost every technical decision in this operation is an attempt to buy room between those two failures.

The trade-off, measured

A meta-analysis of 569 zone II repairs compared early active motion with early passive motion after surgery. The early active group achieved greater total active motion, the outcome that determines whether the finger is useful [1].

The same analysis found the cost. A higher risk of rupture was observed in the group doing active flexion and extension when the tendon had been repaired with a 2-strand core suture [1].

That conditional is the whole point, and it is easy to miss. Early active motion is not inherently dangerous, and 2-strand repair is not inherently weak. The combination is the problem. The strength of the repair and the aggressiveness of the rehabilitation are a single decision made by two people, and they have to be made to match. If your hand therapist and your surgeon appear to be talking to each other about the specific suture used, that is the system working as intended.

Why the literature is harder to read than it should be

A systematic review of 1,878 digital flexor tendon repairs set out to compare 2-strand against multistrand core suture techniques and could not definitively confirm its hypothesis, not because the answer was negative, but because of wide variation in how outcomes and study designs were reported [2].

This is a recurring problem in hand surgery. Different papers use different motion measurements, different definitions of a good result and different follow-up points, which makes pooling them close to meaningless. Where you see confident claims that one repair technique is superior, the honest position from the pooled evidence is that the reporting is not yet consistent enough to say.

Splinting is moving, with the evidence lagging

Relative motion orthoses, splints that hold the repaired finger slightly differently from its neighbours, so tendon glide is shared, have changed extensor tendon rehabilitation. A systematic review of 529 patients concluded there is now good evidence that the approach is safe in zones V–VI extensor repairs, but that evidence for flexor repairs remains limited [3].

So it is a promising direction rather than an established standard on the flexor side, and it is reasonable to ask what protocol is being used and why.

Where technique is heading

One line of work accepts the trade-off and engineers around it. A zone II technique using an externalised detensioning suture, a temporary suture outside the skin that takes load off the repair, substantially strengthened the construct and allowed early active motion with reduced rupture risk, at the cost of limiting distal joint motion until the suture is removed [4].

That is a fair summary of the field: the fundamental tension has not been dissolved, only managed more cleverly.

What this means for your recovery

The therapy is not aftercare, it is part of the operation. Attendance, and doing exactly the prescribed amount rather than more, is what keeps you on the right side of the trade-off described above. A rupture in the first six weeks usually means a second operation with a worse starting point than the first.

Reviewed by Dr Kieran Hirpara · 13 August 2026.

Want the clinical detail? Read the clinician version.

Talk to your treating clinician for advice specific to you.

For an appointment with the CQ Hand + Upper Limb team, ask your GP about a referral or visit www.cqupperlimb.com.

References for the advanced reading
  1. Xu H, Huang X, Guo Z, Zhou H, Jin H, Huang X. Outcome of surgical repair and rehabilitation of flexor tendon injuries in zone II of the hand: systematic review and meta-analysis. J Hand Surg Am. 2023;48(4):407.e1-407.e11.
  2. Hardwicke JT, Tan JJ, Foster MA, Titley OG. A systematic review of 2-strand versus multistrand core suture techniques and functional outcome after digital flexor tendon repair. J Hand Surg Am. 2014;39(4):686-95.e2.
  3. Shaw AV, Verma Y, Tucker S, Jain A, Furniss D. Relative motion orthoses for early active motion after finger extensor and flexor tendon repairs: a systematic review. J Hand Ther. 2023;36(2):332-46.
  4. Suszynski TM, Coutinho D, Kaufmann RA. Flexor tendon repair in zone II augmented with an externalized detensioning suture: protected flexor tendon repair. J Hand Surg Am. 2023;48(10):1065.e1-1065.e4.
Evidence & references

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Overview

  • Flexor tendon repair in Zone II is a technically demanding procedure, but outcomes have become more predictable and satisfying [1].
  • No gold standard has been determined for the optimal flexor tendon repair algorithm, and repairs are usually chosen based on familiarity, popularity, and technical difficulty [2].
  • Zone I flexor tendon injuries traditionally have not yielded results as good as other flexor tendon injuries, with full motion rarely regained and good/excellent results reported in only up to 67% of cases [4].
  • Despite improvements in surgical technique and rehabilitation, functional outcomes for flexor tendon injuries remain unreliable, with adhesion formation and joint contractures being the most common complications [5].
  • Secondary reconstruction remains an important and useful technique for complicated flexor tendon injuries or those that have failed primary repair [6].
  • Consistent, successful management of flexor tendon injuries relies on understanding the anatomy, characteristics and repair of tendons in the different zones, potential complications, rehabilitation protocols, recent advances in treatment, and future directions, including tissue engineering and biologic modification of the repair site [7].
  • Tendon grafting is the treatment of choice for flexor tendon injuries in zones I and II when direct repair is not possible or delayed [8].
  • Limited evidence currently exists for zones IV and VII extensor and for flexor tendon repairs regarding relative motion orthoses for early active motion [10].
  • Many of the principles of flexor tendon repair and rehabilitation can be applied to zones III–V [11].
  • Primary flexor tendon repair in the digital sheath area has become standard practice with a shift toward strong multistrand core sutures and modified pulley preservation [12].
  • A modified protocol for primary flexor tendon repair in zones 1 and 2 utilizes a 6-strand core suture without circumferential suturing, selective pulley division, and partial FDS resection to facilitate early active motion and improve outcomes [19].

Anatomy & Pathophysiology

  • Flexor tendons function as cables that transmit forces to move and stabilize joints [31].
  • An understanding of flexor tendon biomechanics is essential for the proper evaluation and treatment of upper extremity disorders [31].
  • A thorough understanding of flexor tendon anatomy and the mechanism of injury is critical for diagnosis, treatment, and postoperative management [47].
  • Adhesion formation is the most common complication following flexor tendon injuries [5].
  • Joint contractures are the most common complication following flexor tendon injuries [5].
  • Functional outcomes for flexor tendon injuries remain unreliable despite improvements in surgical technique and rehabilitation [5].
  • Therapists must understand the implications of wrist and metacarpophalangeal (MCP) joint positioning to safely facilitate tendon gliding [36].
  • Proper wrist and MCP joint positioning helps prevent secondary pathomechanical changes during rehabilitation [36].
  • Complex hand injuries involving flexor tendon disruption require management of associated soft tissue and bony injuries to optimize functional outcomes [43].

Classification

  • Flexor tendon repair in Zone II is a technically demanding procedure [1].
  • Outcomes for acute flexor tendon repairs in Zone II have become more predictable and satisfying [1].
  • No gold standard has been determined for the optimal flexor tendon repair algorithm [2].
  • Flexor tendon repair techniques are usually chosen based on familiarity, popularity, and technical difficulty [2].
  • Zone I flexor tendon injuries traditionally have not yielded results as good as other flexor tendon injuries [4].
  • Full motion is rarely regained in Zone I flexor tendon injuries [4].
  • Good or excellent results are reported in only up to 67% of Zone I flexor tendon injury cases [4].
  • Secondary reconstruction remains an important and useful technique for complicated flexor tendon injuries [6].
  • Secondary reconstruction remains an important and useful technique for flexor tendon injuries that have failed primary repair [6].
  • Consistent, successful management of flexor tendon injuries relies on understanding the anatomy, characteristics, and repair of tendons in the different zones [7].
  • Tendon grafting is the treatment of choice for flexor tendon injuries in zones I and II when direct repair is not possible or delayed [8].
  • Many principles of flexor tendon repair and rehabilitation can be applied to zones III–V [11].
  • Primary flexor tendon repair in the digital sheath area has become standard practice [12].
  • There is a shift toward strong multistrand core sutures in primary flexor tendon repair in the digital sheath area [12].
  • There is a shift toward modified pulley preservation in primary flexor tendon repair in the digital sheath area [12].
  • Despite significant advances, the drive towards perfection in flexor tendon repair and reconstruction continues [13].
  • Flexor tendon injuries are complex [14].
  • Management of flexor tendon injuries requires consideration of surgical timing [14].
  • Management of flexor tendon injuries requires consideration of injury location [14].
  • Management of flexor tendon injuries requires consideration of approach [14].
  • Management of flexor tendon injuries requires consideration of soft tissue handling [14].
  • Understanding the role that growth factors play in tendon repair should enable a more targeted approach to improve the results of flexor tendon repair [18].
  • Currently, no strategies targeting growth factors are routinely used in clinical practice for flexor tendon repair [18].
  • Subdividing Zone 2 is key to improving outcomes in flexor tendon repair [40].
  • Releasing critical pulleys (A2 and A4) is key to improving outcomes in flexor tendon repair [40].
  • Using strong multi-strand repairs with early active motion is key to improving outcomes in flexor tendon repair [40].

Clinical Presentation

  • Flexor tendon injuries are complex, requiring consideration of surgical timing, injury location, approach, and soft tissue handling [14].
  • Acute flexor tendon repair in Zone II is a technically demanding procedure with outcomes that have become more predictable and satisfying [1].
  • No gold standard has been determined for the optimal flexor tendon repair algorithm; repairs are usually chosen based on familiarity, popularity, and technical difficulty [2].
  • Zone I flexor tendon injuries traditionally have not yielded results as good as other flexor tendon injuries, with full motion rarely regained and good/excellent results reported in only up to 67% of cases [4].
  • Despite improvements in surgical technique and rehabilitation, functional outcomes for flexor tendon injuries remain unreliable [5].
  • Adhesion formation and joint contractures are the most common complications after flexor tendon repair [5].
  • Tendon adhesion and joint contracture are managed through prevention, meticulous surgical technique, and thoughtful rehabilitation protocols [26].
  • Repair ruptures were documented in most reports with rates ranging from 4%-10% in finger flexors and 3%-17% in FPL of thumbs [16].
  • Spontaneous flexor tendon ruptures of the hand occur more often than one might recognize, with the majority involving the profundus tendon of the small finger in the palm [23].
  • Closed flexor tendon disruptions include traumatic avulsion, spontaneous midsubstance rupture, attrition rupture, infiltrative tenosynovial rupture, and iatrogenic causes [32].
  • Pediatric flexor tendon injuries differ from adults in diagnosis and rehabilitation, often requiring surgical exploration due to uncooperative patients [17].
  • Secondary reconstruction remains an important and useful technique for complicated flexor tendon injuries or those that have failed primary repair [6].
  • Consistent, successful management of flexor tendon injuries relies on understanding the anatomy, characteristics and repair of tendons in the different zones, potential complications, rehabilitation protocols, recent advances in treatment, and future directions [7].
  • The central tenet of modern flexor tendon surgery is to increase tendon healing and avoid adhesion formation by making a repair strong enough to move within a few days of injury [15].
  • Understanding the role that growth factors play in tendon repair should enable a more targeted approach to be developed to improve the results of flexor tendon repair, although currently no strategies are routinely used in clinical practice [18].
  • Future techniques, such as tissue engineering, may provide better functional results [25].
  • Recent incremental improvements in clinical outcomes suggest that new biologic strategies, such as cell-based strategies and tissue engineering, may be useful adjuncts to further improve current clinical outcomes in flexor tendon surgery [33].
  • The large heterogeneity in the outcome domains being assessed/measured across studies highlights the need for a consistent core outcome set to be measured in future clinical research on hand flexor tendon injuries [9].
  • Limited evidence currently exists for zones IV and VII extensor and for flexor tendon repairs regarding relative motion orthoses for early active motion [10].

Investigations

  • Flexor tendon repair in Zone II is a technically demanding procedure, but outcomes have become more predictable and satisfying [1].
  • No gold standard has been determined for the optimal flexor tendon repair algorithm, and repairs are usually chosen based on familiarity, popularity, and technical difficulty [2].
  • Despite improvements in surgical technique and rehabilitation, functional outcomes for flexor tendon injuries remain unreliable, with adhesion formation and joint contractures being the most common complications [5].
  • Consistent, successful management of flexor tendon injuries relies on understanding the anatomy, characteristics and repair of tendons in the different zones, potential complications, rehabilitation protocols, recent advances in treatment, and future directions, including tissue engineering and biologic modification of the repair site [7].
  • Limited evidence currently exists for zones IV and VII extensor and for flexor tendon repairs regarding the use of relative motion orthoses for early active motion [10].
  • Many of the principles of flexor tendon repair and rehabilitation can be applied to zones III–V [11].
  • Primary flexor tendon repair in the digital sheath area has become standard practice with a shift toward strong multistrand core sutures and modified pulley preservation [12].
  • Despite significant advances in flexor tendon repair and reconstruction, the drive towards perfection continues [13].
  • Initial clinical experience is encouraging and the volar plate flap technique may take its place in flexor tendon surgery [20].
  • Late direct repair is possible in a small proportion of patients (approximately 1 in 10 to 1 in 15) where tendon ends can be approximated with acceptable tension [21].
  • Despite aggressive and prompt antibiotic therapy and surgical intervention, even otherwise healthy patients can expect some residual digital stiffness following flexor tendon sheath infection [30].

Treatment

  • Flexor tendon repair in Zone II is technically demanding, but outcomes have become more predictable and satisfying [1].
  • Flexor tendon repairs are usually chosen based on familiarity, popularity, and technical difficulty [2].
  • Adhesion formation is the most common complication after flexor tendon injuries [5].
  • Joint contractures are the most common complication after flexor tendon injuries [5].
  • Secondary reconstruction is an important and useful technique for complicated flexor tendon injuries [6].
  • Secondary reconstruction is an important and useful technique for flexor tendon injuries that have failed primary repair [6].
  • Consistent, successful management of flexor tendon injuries relies on understanding the anatomy, characteristics, and repair of tendons in different zones [7].
  • Consistent, successful management of flexor tendon injuries relies on understanding potential complications [7].
  • Consistent, successful management of flexor tendon injuries relies on understanding rehabilitation protocols [7].
  • Consistent, successful management of flexor tendon injuries relies on understanding recent advances in treatment [7].
  • Future directions in flexor tendon injury management include tissue engineering and biologic modification of the repair site [7].
  • Tendon grafting is the treatment of choice for flexor tendon injuries in zones I and II when direct repair is not possible [8].
  • Tendon grafting is the treatment of choice for flexor tendon injuries in zones I and II when repair is delayed [8].
  • Limited evidence currently exists for relative motion orthoses after finger extensor tendon repairs in zones IV and VII [10].
  • Limited evidence currently exists for relative motion orthoses after flexor tendon repairs in zones IV and VII [10].
  • There is a shift toward strong multistrand core sutures in primary flexor tendon repair [12].
  • There is a shift toward modified pulley preservation in primary flexor tendon repair [12].
  • The central tenet of modern flexor tendon surgery is to increase tendon healing and avoid adhesion formation [15].
  • Modern flexor tendon surgery aims to make a repair strong enough to move within a few days of injury [15].
  • Pediatric flexor tendon injuries differ from adults in diagnosis and rehabilitation [17].
  • Pediatric flexor tendon injuries often require surgical exploration due to uncooperative patients [17].
  • Understanding the role of growth factors in tendon repair should enable a more targeted approach to improve flexor tendon repair results [18].
  • A modified protocol for primary flexor tendon repair in zones 1 and 2 utilizes a 6-strand core suture without circumferential suturing [19].
  • A modified protocol for primary flexor tendon repair in zones 1 and 2 utilizes selective pulley division [19].
  • A modified protocol for primary flexor tendon repair in zones 1 and 2 utilizes partial FDS resection to facilitate early active motion and improve outcomes [19].
  • Initial clinical experience with the volar plate of the distal interphalangeal joint as a distally based flap in flexor tendon surgery is encouraging [20].
  • The volar plate flap technique may take its place in flexor tendon surgery [20].
  • Prompt recognition of problems after flexor tendon injury treatment may help minimize recovery time and improve function [22].
  • Treatment of problems after flexor tendon injury with hand therapy, splinting, and/or surgery may help minimize recovery time and improve function [22].
  • Preoperative, operative, and postoperative considerations are key for flexor tenolysis [24].
  • Patient selection is as key to success in flexor tenolysis as the operative procedure itself [24].
  • Cooperation is as key to success in flexor tenolysis as the operative procedure itself [24].
  • A rational goal is as key to success in flexor tenolysis as the operative procedure itself [24].
  • Tendon adhesion and joint contracture are the most common complications after flexor tendon repair [26].
  • Tendon adhesion and joint contracture after flexor tendon repair are managed through prevention, meticulous surgical technique, and thoughtful rehabilitation protocols [26].
  • Some authors no longer perform flexor tendon repair with tourniquet, sedation, or muscle paralysis in zones 1 and 2 [37].
  • There is not sufficient evidence to support true active motion as an effective or preferable choice for flexor tendon rehabilitation at this time [38].
  • There is a lack of superior benefits following true active motion regimens for flexor tendon rehabilitation [38].
  • There is currently limited evidence informing the use of relative motion flexion orthoses following zone I-III flexor tendon repair [45].
  • Increasing the number of suture strands significantly improves the mechanical strength and gap resistance of flexor tendon repairs [48].
  • Using locking-loop configurations significantly improves the mechanical strength and gap resistance of flexor tendon repairs [48].
  • Optimizing suture purchase length significantly improves the mechanical strength and gap resistance of flexor tendon repairs [48].

Complications

  • Adhesion formation is one of the most common complications following flexor tendon injuries [5].
  • Joint contractures are one of the most common complications following flexor tendon injuries [5].
  • Residual digital stiffness is expected even in otherwise healthy patients following flexor tendon sheath infection, despite aggressive and prompt antibiotic therapy and surgical intervention [30].
  • Repair rupture rates for finger flexors range from 4% to 10% [16].
  • Repair rupture rates for the flexor pollicis longus (FPL) of thumbs range from 3% to 17% [16].
  • Repair rupture rates are reported at 2% to 5% for tendons repaired with 4-strand or 6-strand core sutures [49].
  • Very low to zero incidence of rupture is reported for Zone 2 repairs in some contexts [50].
  • Late direct repair is possible in approximately 1 in 10 to 1 in 15 patients where tendon ends can be approximated with acceptable tension [21].
  • Prompt recognition of problems and treatment with hand therapy, splinting, and/or surgery may help minimize recovery time and improve function [22].

Recovery

  • A modified protocol for primary flexor tendon repair in zones 1 and 2 utilizes a 6-strand core suture without circumferential suturing, selective pulley division, and partial FDS resection to facilitate early active motion and improve outcomes [19].
  • Repeated administration of sodium hyaluronate at the tendon repair site may be effective in improving postoperative active finger motion after primary hand flexor tendon repair in the mid-term [27].
  • The author recommends the partial-range active flexion protocol as a safe, efficient, and generalizable framework for rehabilitation after flexor tendon repair and other hand disorders, particularly where therapist assistance is unavailable [28].
  • Future research is suggested to increase understanding of repair strength, optimal age ranges for early active motion, and cost-effectiveness in children [29].
  • Rehabilitation after surgical repair of flexor injuries is a controversial topic where motion at the repair site decreases risk for adhesions but increases risk for rupture [34].

Key Evidence

  • [L5] Flexor tendon repair in Zone II is a technically demanding procedure, but outcomes have become more predictable and satisfying. [1] (10.1016/j.hcl.2004.11.001)
  • [L5] No gold standard has been determined for the optimal flexor tendon repair algorithm, and repairs are usually chosen based on familiarity, popularity, and technical difficulty. [2] (10.1016/j.jhsa.2014.06.025)
  • [L5] Zone I flexor tendon injuries traditionally have not yielded results as good as other flexor tendon injuries, with full motion rarely regained and good/excellent results reported in only up to 67% of cases. [4] (10.1016/j.hcl.2004.12.004)
  • [L5] Despite improvements in surgical technique and rehabilitation, functional outcomes for flexor tendon injuries remain unreliable, with adhesion formation and joint contractures being the most common complications. [5] (10.1016/j.hcl.2009.11.004)
  • [L5] Secondary reconstruction remains an important and useful technique for complicated flexor tendon injuries or those that have failed primary repair. [6] (10.1016/j.jhsa.2007.08.018)
  • [L5] Consistent, successful management of flexor tendon injuries relies on understanding the anatomy, characteristics and repair of tendons in the different zones, potential complications, rehabilitation protocols, recent advances in treatment, and future directions, including tissue engineering and biologic modification of the repair site. [7] (10.5435/jaaos-d-16-00316)
  • [L5] Tendon grafting is the treatment of choice for flexor tendon injuries in zones I and II when direct repair is not possible or delayed. [8] (10.1016/j.hcl.2004.12.003)
  • [L2] The large heterogeneity in the outcome domains being assessed/measured across studies highlights the need for a consistent core outcome set to be measured in future clinical research on hand flexor tendon injuries. [9] (10.1177/17531934251342732)
  • [L1] Limited evidence currently exists for zones IV and VII extensor and for flexor tendon repairs. [10] (10.1016/j.jht.2023.02.011)
  • [L5] Many of the principles of flexor tendon repair and rehabilitation can be applied to zones III–V. [11] (10.1016/j.hcl.2004.11.007)
  • [L5] Primary flexor tendon repair in the digital sheath area has become standard practice with a shift toward strong multistrand core sutures and modified pulley preservation. [12] (10.1016/j.hcl.2013.02.003)
  • [L5] Despite significant advances in flexor tendon repair and reconstruction, the drive towards perfection continues. [13] (10.1177/17531934251404821)
  • [L5] Flexor tendon injuries are complex, and management requires consideration of surgical timing, injury location, approach, and soft tissue handling. [14] (10.1016/j.jhsa.2024.05.013)
  • [L4] The central tenet of modern flexor tendon surgery is to increase tendon healing and avoid adhesion formation by making a repair strong enough to move within a few days of injury. [15] (10.1016/j.hcl.2013.03.001)
  • [L4] Repair ruptures were documented in most reports with rates ranging from 4%-10% in finger flexors and 3%-17% in FPL of thumbs. [16] (10.1016/j.hcl.2004.11.005)
  • [L5] Pediatric flexor tendon injuries differ from adults in diagnosis and rehabilitation, often requiring surgical exploration due to uncooperative patients. [17] (10.1016/j.hcl.2004.11.004)
  • [L5] Understanding the role that growth factors play in tendon repair should enable a more targeted approach to be developed to improve the results of flexor tendon repair, although currently no strategies are routinely used in clinical practice. [18] (10.1177/1753193413509231)
  • [L5] The authors describe a modified protocol for primary flexor tendon repair in zones 1 and 2 that utilizes a 6-strand core suture without circumferential suturing, selective pulley division, and partial FDS resection to facilitate early active motion and improve outcomes. [19] (10.1016/j.hcl.2017.03.001)
  • [L4] Initial clinical experience is encouraging and the volar plate flap technique may take its place in flexor tendon surgery. [20] (10.1016/j.jhsa.2015.11.004)
  • [L4] Late direct repair is possible in a small proportion of patients (approximately 1 in 10 to 1 in 15) where tendon ends can be approximated with acceptable tension. [21] (10.1016/j.hcl.2013.02.004)
  • [L5] Prompt recognition of problems and treatment with hand therapy, splinting, and/or surgery may help minimize recovery time and improve function. [22] (10.5435/00124635-200607000-00001)
  • [L4] Spontaneous flexor tendon ruptures of the hand occur more often than one might recognize, with the majority involving the profundus tendon of the small finger in the palm. [23] (10.1016/j.jhsa.2007.06.012)
  • [L5] The article outlines preoperative, operative, and postoperative considerations for flexor tenolysis, emphasizing that patient selection, cooperation, and a rational goal are as key to success as the operative procedure itself. [24] (10.1016/j.hcl.2004.11.008)
  • [L5] Future techniques, such as tissue engineering, may provide better functional results. [25] (10.5435/jaaos-d-14-00195)
  • [L5] Tendon adhesion and joint contracture are the most common complications after flexor tendon repair, managed through prevention, meticulous surgical technique, and thoughtful rehabilitation protocols. [26] (10.1016/j.hcl.2014.12.004)
  • [L1] Repeated administration of sodium hyaluronate at the tendon repair site may be effective in improving postoperative active finger motion after primary hand flexor tendon repair in the mid-term. [27] (10.1016/j.jhsa.2021.07.012)
  • [L5] The author recommends the partial-range active flexion protocol as a safe, efficient, and generalizable framework for rehabilitation after flexor tendon repair and other hand disorders, particularly where therapist assistance is unavailable. [28] (10.1177/17531934211037112)
  • [L5] Future research is suggested to increase understanding of repair strength, optimal age ranges for early active motion, and cost-effectiveness. [29] (10.1016/j.jht.2014.12.002)
  • [L5] Despite aggressive and prompt antibiotic therapy and surgical intervention, even otherwise healthy patients can expect some residual digital stiffness following flexor tendon sheath infection. [30] (10.5435/jaaos-20-06-373)
  • [L5] An understanding of the biomechanics of the flexor tendon system is essential to proper evaluation and treatment of disorders of the upper extremity, as the tendons function as cables transmitting forces to move and stabilize joints. [31] (10.1016/j.hcl.2004.11.002)
  • [L5] This article reviews different causes, diagnoses, and treatment options of closed flexor tendon disruptions, including traumatic avulsion, spontaneous midsubstance rupture, attrition rupture, infiltrative tenosynovial rupture, and iatrogenic causes. [32] (10.1016/j.jhsa.2014.04.005)
  • [L5] Recent incremental improvements in clinical outcomes suggest that new biologic strategies, such as cell-based strategies and tissue engineering, may be useful adjuncts to further improve current clinical outcomes in flexor tendon surgery. [33] (10.1016/j.hcl.2005.01.001)
  • [L5] Rehabilitation after surgical repair of flexor injuries is a controversial topic where motion at the repair site decreases risk for adhesions but increases risk for rupture. [34] (10.1016/j.jhsa.2019.02.010)
  • [L5] Therapists must understand the implications of wrist and MCP joint positioning to safely facilitate tendon gliding and prevent secondary pathomechanical changes. [36] (10.1177/17531934241265579)
  • [L5] The authors no longer perform flexor tendon repair with tourniquet, sedation, or muscle paralysis. [37] (10.1016/j.hcl.2013.02.009)
  • [L1] Based on a lack of superior benefits following true active motion regimens, there is not sufficient evidence to support true active motion as an effective or preferable choice for flexor tendon rehabilitation at this time. [38] (10.1016/j.jht.2018.06.001)
  • [L5] The article reviews a three-decade research journey demonstrating that subdividing Zone 2, releasing critical pulleys (A2 and A4), and using strong multi-strand repairs with early active motion are key to improving outcomes in flexor tendon repair. [40] (10.1177/17531934221087585)
  • [L5] Complex hand injuries involving flexor tendons require a physician-therapist team approach and management of associated soft tissue and bony injuries to optimize functional outcomes. [43] (10.1016/j.hcl.2004.12.001)
  • [L4] There is currently limited evidence informing use of relative motion flexion orthoses following flexor tendon repair. [45] (10.1016/j.jht.2022.11.004)
  • [L5] A thorough understanding of the anatomy and mechanism of injury is critical for diagnosis, treatment, and postoperative management. [47] (10.1016/j.csm.2019.12.004)
  • [L5] Increasing the number of suture strands, using locking-loop configurations, and optimizing suture purchase length significantly improve the mechanical strength and gap resistance of flexor tendon repairs. [48] (10.1016/j.jhsa.2009.12.044)
  • [L1] Over the past 10 years, surgeons have reported good to excellent results in about 80% or more of tendons repaired with 4-strand or 6-strand core sutures, with 2% to 5% repair ruptures. [49] (10.1016/j.hcl.2013.02.007)
  • [L5] Outcomes of Zone 2 repairs are not dissimilar to those in other zones with very low to zero incidence of rupture. [50] (10.1177/17531934211053757)

References

[1] Acute Flexor Tendon Repairs in Zone II. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.11.001

[2] Flexor Tendon Repairs: Techniques, Eponyms, and Evidence. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2014.06.025

[4] Zone I Flexor Tendon Injuries. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.12.004

[5] Complications After Flexor Tendon Injuries. Hand Clinics. 2010. DOI: 10.1016/j.hcl.2009.11.004

[6] Secondary Flexor Tendon Reconstruction, A Review. The Journal of Hand Surgery. 2007. DOI: 10.1016/j.jhsa.2007.08.018

[7] Flexor Tendon Injuries. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-16-00316

[8] Delayed Treatment of Flexor Tendon Injuries Including Grafting. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.12.003

[9] Developing a core outcome set for hand flexor tendon injuries: a systematic review of treatment outcomes. Journal of Hand Surgery (European Volume). 2025. DOI: 10.1177/17531934251342732

[10] Relative motion orthoses for early active motion after finger extensor and flexor tendon repairs: A systematic review. Journal of Hand Therapy. 2023. DOI: 10.1016/j.jht.2023.02.011

[11] Treatment of Acute Flexor Tendon Injury: Zones III–V. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.11.007

[12] Current Practice of Primary Flexor Tendon Repair. Hand Clinics. 2013. DOI: 10.1016/j.hcl.2013.02.003

[13] The IFSSH consensus and current guidelines on flexor tendon repairs and reconstruction. Journal of Hand Surgery (European Volume). 2026. DOI: 10.1177/17531934251404821

[14] Flexor Tendon Injuries. The Journal of Hand Surgery. 2024. DOI: 10.1016/j.jhsa.2024.05.013

[15] Primary Flexor Tendon Surgery. Hand Clinics. 2013. DOI: 10.1016/j.hcl.2013.03.001

[16] Clinical Outcomes Associated with Flexor Tendon Repair. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.11.005

[17] Pediatric Flexor Tendon Injuries. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.11.004

[18] The growth factors involved in flexor tendon repair and adhesion formation. Journal of Hand Surgery (European Volume). 2013. DOI: 10.1177/1753193413509231

[19] Primary Flexor Tendon Repair with Early Active Motion. Hand Clinics. 2017. DOI: 10.1016/j.hcl.2017.03.001

[20] Use of the Volar Plate of the Distal Interphalangeal Joint as a Distally Based Flap in Flexor Tendon Surgery. The Journal of Hand Surgery. 2016. DOI: 10.1016/j.jhsa.2015.11.004

[21] Uncommon Methods of Flexor Tendon and Tendon-Bone Repairs and Grafting. Hand Clinics. 2013. DOI: 10.1016/j.hcl.2013.02.004

[22] Complications After Treatment of Flexor Tendon Injuries. Journal of the American Academy of Orthopaedic Surgeons. 2006. DOI: 10.5435/00124635-200607000-00001

[23] Spontaneous Flexor Tendon Ruptures of the Hand: Case Series and Review of the Literature. The Journal of Hand Surgery. 2007. DOI: 10.1016/j.jhsa.2007.06.012

[24] Flexor Tenolysis. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.11.008

[25] Flexor Tendon Reconstruction. Journal of the American Academy of Orthopaedic Surgeons. 2016. DOI: 10.5435/jaaos-d-14-00195

[26] Management of Complications of Flexor Tendon Injuries. Hand Clinics. 2015. DOI: 10.1016/j.hcl.2014.12.004

[27] Effectiveness of Sodium Hyaluronate and ADCON-T/N for the Prevention of Adhesions in Hand Flexor Tendon Surgery: A Systematic Review and Meta-Analysis. The Journal of Hand Surgery. 2022. DOI: 10.1016/j.jhsa.2021.07.012

[28] Rehabilitation after flexor tendon repair and others: a safe and efficient protocol. Journal of Hand Surgery (European Volume). 2021. DOI: 10.1177/17531934211037112

[29] Flexor tendon injuries in children: Rehabilitative options and confounding factors. Journal of Hand Therapy. 2015. DOI: 10.1016/j.jht.2014.12.002

[30] Flexor Tendon Sheath Infections of the Hand. Journal of the American Academy of Orthopaedic Surgeons. 2012. DOI: 10.5435/jaaos-20-06-373

[31] Biomechanics of the Flexor Tendons. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.11.002

[32] Closed Flexor Tendon Ruptures. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2014.04.005

[33] The Future of Flexor Tendon Surgery. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2005.01.001

[34] Postsurgical Rehabilitation of Flexor Tendon Injuries. The Journal of Hand Surgery. 2019. DOI: 10.1016/j.jhsa.2019.02.010

[36] Zone-specific pitfalls in flexor tendon rehabilitation: management and prevention. Journal of Hand Surgery (European Volume). 2024. DOI: 10.1177/17531934241265579

[37] Wide-awake Flexor Tendon Repair and Early Tendon Mobilization in Zones 1 and 2. Hand Clinics. 2013. DOI: 10.1016/j.hcl.2013.02.009

[38] Flexor tendon rehabilitation in the 21st century: A systematic review. Journal of Hand Therapy. 2019. DOI: 10.1016/j.jht.2018.06.001

[40] Investigations into flexor tendon repair: a research journey over three decades. Journal of Hand Surgery (European Volume). 2022. DOI: 10.1177/17531934221087585

[43] Complex Injuries Including Flexor Tendon Disruption. Hand Clinics. 2005. DOI: 10.1016/j.hcl.2004.12.001

[45] Relative motion flexion following zone I-III flexor tendon repair: Concepts, evidence and practice.. Journal of Hand Therapy. 2023. DOI: 10.1016/j.jht.2022.11.004

[47] Evaluation and Treatment of Flexor Tendon and Pulley Injuries in Athletes. Clinics in Sports Medicine. 2020. DOI: 10.1016/j.csm.2019.12.004

[48] Technical and Biological Modifications for Enhanced Flexor Tendon Repair. The Journal of Hand Surgery. 2010. DOI: 10.1016/j.jhsa.2009.12.044

[49] Outcomes and Evaluation of Flexor Tendon Repair. Hand Clinics. 2013. DOI: 10.1016/j.hcl.2013.02.007

[50] Flexor tendon repair: recent changes and current methods. Journal of Hand Surgery (European Volume). 2021. DOI: 10.1177/17531934211053757

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