Doi:10.1016/j.jhsa.2005.04.013

Open Traumatic Avulsion of the
Flexor Pollicis Longus Tendon
From the Musculotendinous Area:
A Case Report
Panagiotis Givissis, MD, PhD, Dimitrios Karataglis, MD,
Anastasios Christodoulou, MD, PhD, Ioannis Terzidis, MD,
John Pournaras, MD, PhD, Thessaloniki, Greece
A traumatic avulsion of the flexor tendon at the musculotendinous junction in nonamputated digits
is a very rare injury. We present a 14-year-old girl who sustained a longitudinal, tensile, injurious
force directly to the flexor pollicis longus tendon after an open thenar injury resulting in its avulsion
at the musculotendinous junction. In an effort to minimize soft-tissue damage and preserve the
transverse ligament of the carpus the tendon was retrieved through a separate forearm incision.
Direct repair was made by encapsulation of the tendon into the muscle belly. The functional result
30 months after surgery was satisfactory. (J Hand Surg 2005;30A:850 – 853. Copyright 2005 by
the American Society for Surgery of the Hand.)
Key words: Flexor pollicis longus, avulsion, musculotendinous area.
The musculotendinous junction together with the bony very rare for the flexor pollicis where avul- insertion are considered the weakest links of the mus- sions of the entire tendon length in any given digit can culotendinous chain, the former being by far the more occur, including the tMoreover the anatomy common site of Despite this only 6 closed and profound functional importance of this tendon ren- flexor tendon ruptures at the musculotendinous area have been reported to Of these 6 ruptures 3 We present a case of traumatic avulsion of the ruptures involved the flexor digitorum superficialis and flexor pollicis longus tendon from its musculotendi- the remaining 3 ruptures involved the flexor pollicis nous junction resulting from extreme longitudinal With the exception of traumatic conditions force applied to the tendon after an open hand injury.
associated with digit amputations this type of injury is The chosen technique for direct repair led to a verysatisfactory functional outcome without the need fora tendon transfer.
From the A’ Orthopaedic Department, Aristotelian University of Thes-saloniki, “G. Papanikolaou” General Hospital, Exohi, 570 10, Thessal- Case Report
Received for publication November 11, 2003; accepted in revised form A 14-year-old girl sustained direct trauma to the right dominant hand when she slipped while climbing a No benefits in any form have been received or will be received from fence and a pointed spear-like bar entered her palm at a commercial party related directly or indirectly to the subject of thisarticle.
the thenar eminence just underneath the tendon of the Corresponding author: Panagiotis Givissis, MD, PhD, 33 Abatzoglou str., flexor pollicis longus. She impulsively released her 40 Eklissies, 546 36, Thessaloniki, Greece; e-mail: [email protected].
grip and that left her momentarily hanging from the Copyright 2005 by the American Society for Surgery of the Hand FPL tendon. This resulted in complete proximal 0363-5023/05/30A04-0031$30.00/0doi:10.1016/j.jhsa.2005.04.013 avulsion of the flexor pollicis longus tendon from its Givissis et al / Avulsion of the Flexor Pollicis Longus Tendon the tendon stump was sutured side to side to the distaledge of the catheter. In a modification of the tech-nique described by Sourmelis and thetendon subsequently was rerouted through the carpaltunnel to the proximal wound at the level of its owntorn muscle belly at the musculotendinous junction.
The tendon stump was sutured back to the musclebelly with 4 interrupted 3-0 sutures (Ethibond; John-son & Johnson, St Stevens-Woluve, Belgium) placedthrough the tendon and the muscle fibers. Length andtension restoration were checked during surgery byusing the tenodesis test. Because the flexor pollicislongus is a unipinate muscle, encapsulation of thetendon stump within the muscle belly was addition-ally performed to reinforce the repair. The techniqueused was that of draping the replaced tendon withmuscle substance using the same suture materialSubsequently the A1 pulley was recon-structed and augmented using part of the flexor pol-licis brevis tendon. The radial digital nerve of thethumb was sutured end to end with 2 epineural in-terrupted 8-0 sutures (Prolene; Johnson & Johnson)under microscope magnification. Finally the skin wasclosed with a 4-flap Z-plasty at the site of the basalskin crease of the thumb to avoid skin contracture.
Cefuroxime in conjunction with amikasin and met-ronidazole were administered for 3 days. An above-elbow plaster cast was used for 3 weeks, followed bybelow-elbow immobilization for a further 3-weekperiod with the thumb held in moderate flexion andabduction. Passive continuous motion as postopera-tive rehabilitation was commenced the second post-operative day and active mobilization was initiated 6weeks after surgery.
Figure 1. Preoperative view of avulsion of the entire tendon
of the flexor pollicis longus through the thenar wound.
The wounds healed promptly and no complica- muscle belly and laceration of the flexor pollicisbrevis, the A1 pulley, and the radial digital nerve tothe thumb She was admitted to our hospital within 4 hours of the initial injury and was taken immediately to theoperating room. General anesthesia was induced anda tourniquet was used after administration of intra-venous antibiotics. After thorough wound debride-ment and copious irrigation a second incision wasmade in the volar aspect of the distal third of theforearm to access the muscle belly of the flexorpollicis longus. The site of avulsion at the musculo-tendinous junction was identified and a catheter was Figure 2. Tendon reconstruction and augmentation with en-
introduced from the thenar wound through the carpal capsulation of the tendon in the flexor pollicis longus muscle tunnel to the forearm wound. The proximal end of The Journal of Hand Surgery / Vol. 30A No. 4 July 2005 Figure 3. The hand 30 months after surgery. Thumb movement regarding (A) extension, (B) flexion, and (C) opposition at both
the metacarpophalangeal and interphalangeal joints returned very close to normal.
tions were observed. Thumb movement at both the pollicis The rarity of this injury to the metacarpophalangeal and interphalangeal joints re- flexor pollicis longus combined with the anatomy turned very close to normal within 4 months (full and profound functional importance of this tendon— flexion, 10° extension deficit of the interphalangeal because the thumb provides more than 40% of the joint of the involved side, full opposition) entire hand’s function—render this injury unique and On final follow-up evaluation 30 months after sur- justify every effort for primary Only 3 such gery the functional result as evaluated according to cases of closed rupture of the flexor pollicis longus the criteria of Fitoussi et was excellent with a tendon at the musculotendinous junction have been score of 9 of 9. Grip strength was tested with a reported to date: 2 by Boyes et in which no further dynamometer (5030 J1 Jamar Hand Dynamometer; details were provided by the authors and 1 by Takami Sammons and Preston, Bolingbrook, IL) and reached et in a 23-year-old woman who had closed rupture 93.7% of the strength of the uninjured side. Key, of the flexor pollicis longus while bowling. None of pulp, and tripod grip strengths were tested with a the earlier-described 3 cases was open, nor did these pinch meter (Baseline Link Pinch meter; Waldemar patients have immediate surgery. In the last case a Link, Hamburg, Germany) and reached 81%, 97.7%, direct repair was impossible, necessitating a tendon and 90.2% of the strength of the uninjured side, transfer in which the flexor digitorum superficialis respectively. Two-point discrimination on the pa- tendon to the ring finger was transferred to that of the tient’s thumb was 5 mm at the sensory area of the flexor pollicis longus. Furthermore the 2 cases de- repaired digital nerve compared with 4 mm on the scribed by Boyes et aloccurred through diseased tendons. Our case seems to be the second that oc- Discussion
curred through apparently normal tendon. In our case Avulsion-type injuries of the flexor tendons at their the hand injury was open and the injurious force was bony insertion and disruptions in the musculotendi- extreme. The force was applied directly to the tendon nous junction associated with traumatic digit ampu- itself, leading to its avulsion from the musculature of tations have been well documented in the litera- the flexor pollicis longus. It is well known from the normal flexor tendons occurs infrequently and little mal muscle–tendon system is subjected to severe has been reported about these ruptures. Isolated strain the tendon does not rupture. Instead rupture flexor tendon rupture at the musculotendinous junc- may occur at the insertion of the tendon to bone, at tion in the absence of digit amputation is a very the musculotendinous junction, through the belly of unusual injury pattern and is believed to result from the muscle, or at its origin from the bone. In our case the original soft-tissue trauma involved the thenar have been reported to date, 3 involving the flexor region and the base of the thumb. In an effort to digitorum superficialis and 3 involving the flexor minimize further induced soft-tissue trauma and to Givissis et al / Avulsion of the Flexor Pollicis Longus Tendon preserve the carpal tunnel we used a modification of chance of speedy return of good function and there- a technique described by Sourmelis and Mc- for retrieving retracted flexor tendons with the aid of a catheter. We believe that in the context of to retrieve the proximal stump of retracted flexor extensive soft-tissue trauma in the region, preserva- tendons with the aid of a catheter was used success- tion of the carpal tunnel, which is an all-important fully in a vice versa manner to repair the musculo- pulley, and minimizing surgical trauma provided a tendinous chain with the least possible soft-tissue more favorable environment for tissue healing and functional recovery. Healing of the muscle–tendoncomplex was successful, which to a certain extent The authors thank Dr Konstantinos Ditsios for assistance in the final can be attributed to the rich vascularization of the editing of the manuscript and Dr Aggeliki Lambanari for assistance withthe drawings.
There was no evidence of adhesion forma-tion and one could argue that the chosen method of References
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