Abstract
Background:
Closed finger flexor tendon pulley injuries occur most frequently in rock climbing but also during other heavy finger strength work or exercises. While single pulley injuries receive a conservative therapy, multiple pulley injuries often require a surgical repair, as otherwise they will lead to contracture and loss of range of motion and functionality. While established surgical techniques, which use bone encircling tendon graft techniques, were found to produce osteonecrosis of the phalanx, our new transosseous technique avoids this problem.
Indications:
All triple pulley injuries (A2,3,4) (grade-4b injuries) and double pulley injuries (A2,3 or A3,4) (grade-4a injuries) are indicated, if the injury is older than 10 days at the point of therapy start or the flexor tendons bowstringing is either not redressable in the ultrasound or extended. Also, grade-4a injuries are indicated, if a secondary contracture starts to build.
Technique Description:
Standard palmar-sided incision, followed by debridement of the tendon sheath, pulley flap, and, if applicable, scare tissue in between the flexor tendons and the bone is performed. Wire-guided 3.0-mm drill holes at the base phalanx at the level of the former distal portion of the A2 pulley are completed. Passing of the palmaris longus tendon through the drill hole and interlacing it as a “loop and a half” follows. Distal continuation through lacing the transplant through the remaining rims of the former pulleys and the flexor tendon sheath is then performed. Securing the repair after tendon gliding control to itself is completed. Postsurgically, the splint is immobilized for 2 weeks, followed by the use of a thermoplastic pulley support ring for 4 weeks with active mobilization.
Results:
No complications occurred during or after the surgery. In few cases, a restricted range of motion in the proximal interphalangeal (PIP) joint of the respective finger of up to 3 to 5 grade occurred. One patient, who had a presurgical PIP extension deficit of 30°, which was released during the surgery, developed over time again a 20° extension deficit. The functional outcome score ranged between good and excellent, with one case being only satisfactory. The sport-specific outcome score was either good or excellent for all patients, with one patient with contracture where it was satisfactory. No osteonecrosis of the phalanx was recorded.
Discussion:
For multiple pulley ruptures, various surgical techniques are described. We favored a modified “loop and a half” technique with a distal continuation to the A3 pulley. This combines the advantages of the “loop and a half” technique, as the strongest, and the Weilby repair, as the most functional repair. We recently noticed some cases with osseous necrosis of the phalanx following this repair, likely due to the high pressure of the circulation of the tendon graft onto the bone and its blood vessels. Therefore, we have modified our procedure into a transosseous repair, which is presented in this article. This approach was first evaluated in a cadaver study to exclude a potential risk of osseous failure (fracture) during stress caused by the drill hole. After ruling out this risk, the transosseous technique became our standard approach, as it combines the advantages of the “loop and a half” technique with those of the Weilby repair and decreases the pressure onto the dorsal cortex of the fingers base phalanx and thus the risk of osteonecrosis.
This is a visual representation of the abstract.
Video Transcript
In this video we will present our method for transosseous multiple finger flexor tendon pulley reconstruction.
There are no relevant disclosures.
Transosseous pulley reconstruction is a valuable procedure for multiple finger flexor tendon pulley ruptures.
The surgical technique includes the following: standard palmar-sided incision and debridement of the tendon sheath; harvesting of ipsilateral palmaris longus tendon; wire-guided 3.0 drill hole at the base phalanx; passing of transplant through phalanx and interlacing the “loop and a half” technique; distal lacing of transplant through the remaining rims of pulley.
Closed finger flexor tendon pulley injuries are the most specific injuries in rock climbing, but also in other finger strength work or exercises. While single-pulley injuries receive a conservative therapy, multiple-pulley injuries often require a surgical repair as otherwise they will lead to contracture and loss of range of motion and functionality.
While established surgical techniques using bone encircling tendon graft techniques were found to produce osteonecrosis of the phalanx, our new transosseous technique targets to avoid this problem.
The human flexor tendon pulley system consists of 5 annular (A1-A5) and 3 weaker crucial ligaments (C1-C3). 9
The main function of the flexor tendon pulley system is to hold the flexor tendons close to the bone, thus converting linear force into torque resulting in rotation at the interphalangeal and metacarpophalangeal joints. 9 A loss of one or several of the pulleys will cause an increased distance between the flexor tendons and the bone, a “bowstringing,” and leads to a loss of strength and a decreased range of motion. 9
Physical examination reveals tenderness over the palmar level of the injured pulley accompanied by swelling and occasionally hematoma. A visible bowstring only occurs with multiple pulley ruptures.4,9 The diagnostic standard is an ultrasound examination, which shows the increased distance in between the flexor tendons and the bone at the level of the injured pulley. 1 With a high-resolution ultrasound probe (>15 Mhz) even a direct visualization of the pulleys is possible. In cases of diagnostic uncertainty, a magnetic resonance imaging (MRI) can be helpful. 9
Pulley ruptures are graded into strains (grade 1), partial tears (grade 2), complete singular tears (grade 3), and multiple tears (double-pulley injury A2/3 or A3/4 grade 4a and triple-pulley injuries A2/3/4 as grade 4b). 3
Single-pulley injuries (grade I-III) receive a conservative therapy with an optional initial short period of immobilization and early functional therapy with a thermoplastic pulley support ring.3,4,9
In grade-IV injuries (multiple pulley injuries), the general recommendation is a surgical repair. 3 Otherwise, the permanently increased tendon bone distance and scarring will cause flexion contracture. 9 Many various pulley reconstruction techniques are reported in the literature, as for example, the Kleinert and Bennet repair based on Weilby repair, Karev belt-loop-technique, the single-loop-technique according to Bunnel, the Lister repair with retinaculum flexorum, a palmaris longus tendon transplantation through the volar plate according to Doyle, the Widstrom “loop and a half”-technique and others. 10
For over 10 years, we favored a modified “loop and a half” technique with a distal continuation to the A3 pulley. 10 This combines the advantages of the “loop and a half” as the strongest and the Weilby repair as the most functional repair. 10 Nevertheless, we recently noticed that some osseous necrosis of the phalanx can occur following this repair, likely due to the high pressure of the circulation onto the bone and its blood vessels. 2
Therefore, we have modified our procedure into an transosseous repair, to decrease pressure and disturbance on blood flow of the dorsal-sided cortex of the base phalanx. This approach was first evaluated in a cadaver study to exclude a potential risk of osseous failure (fracture) during stress caused by the drill hole. 8 After ruling out this risk, the transosseous technique became our standard approach as it combines the advantages of the “loop and a half” technique with those of the Weilby repair and decreases the pressure onto the dorsal cortex of the fingers base phalange and thus the risk of osteonecrosis. Normally for an A2,3,4 pulley rupture, the A2 pulley is repaired with the “one and a half” loop continued distally up to the level of the A3 pulley. The A4 pulley is not regularly addressed.
The surgery is performed under either general anesthesia, plexus anesthesia, or in wide-awake local anesthesia no tourniquet (WALANT). The hand is positioned on the dorsum and fixed in a surgical hand plate. A tourniquet is applied at the upper arm with a pressure of 250 to 300 mm Hg. Standard volar Brunner zig-zag incision, followed by debridement of the tendon sheath, pulley flap and if applicable scare tissue in between the flexor tendons and the bone. The lateral remaining rims of the pulleys along with the tendon sheath are preserved, as these parts are essential to the repair technique.
In the next step, the transplant and the ipsilateral palmaris longus tendon is harvested. Transverse incision at the volar wrist flexion fold and identification of the tendon. After mobilizing, it is stripped with a small tendon stripper and controlled for its quality and length as a transplant. After hemostasis, 2 layer closure of the subcutis and dermis. The graft is preserved in a saline fluid soaked compress and further preparation on the finger continued.
Identification and mobilization of the collateral neurovascular bundle on both sides and wire guided 3.0 mm drill hole (Arthrex disposable kit for 3 × 8.00 mm Bio Tenodesis screw [Arthrex; Naples, FL]) perpendicular to the lateral cortex of the base phalanx at the level of the former distal portion of the A2 pulley. First the guide wire is drilled at the respective spot horizontally through the bone, while the neurovascular bundle is protected by a retractor. After passing the contralateral cortex, the guide wires position is controlled as to exclude that it is too close to the volar or dorsal cortex to prevent breakage of the bone tunnel. Then, secondary the 3.0 mm drill hole is performed wire guided. The graft is passed through the drill with a quick pass tendon shuttle. The tendon graft is then interlaced with itself for the initial “loop and a half” using a Strehli clamp after incision of the graft and sutured together for reinforcement using 4.0 PDS (Ethicon, Norderstedt, FRG). Bevor the fixation of the grafts interlace the correct tension of the graft is controlled via passive and active (if WALANT) movement of the finger to control for a free movement and a good reposition of the flexor tendons.
Next the remaining graft is continued distally as a Weilby repair, involving lacing of the transplant through the remaining rims of the former pulleys and the flexor tendon sheath. Therefore, a minor incision with a no.11 scalpel is done at the very base of the rim of the former pulley and the graft pulled through using a clamp. Each point of contact between graft and pulley stump is reinforced with 2 single stitches using the same suture material mentioned above. Then the distal end of the graft is sutured to itself. Before securing the distal end of the tendon, the repair is tightened gradually after manual tensioning and control of a free movement of the flexor tendons. After a final control for a free movement and a sufficient reposition of the flexor tendons and hemostasis, the skin is closed single layer and immobilized onto a volar sided cast splint. A drain is optional.
Postsurgically, the finger is immobilized until completion of skin healing, using a volar-sided cast splint for a maximum of 2 weeks. Thereafter, a thermoplastic pulley support ring is implemented and gentle active range of motion exercises commence. 6 Six weeks after surgery, free movement without the support ring is allowed, and the functional therapy can be intensified. Specific rehabilitation exercises can be resumed after 2 weeks, once the surgical site edema has completely resolved. Easy climbing and climbing-specific training are allowed after 4 months (with protective H-taping 7 ). Taping should be continued through climbing for another 6 months. The full, sport-specific load can be assumed after 6 to 9 months.
Footnotes
Submitted October 19, 2021; accepted January 12, 2022.
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
