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Short report letters Merries International, Shin Tien, Taiwan). Platelet glue was prepared by mixing thrombinrich gel and plasma-rich platelets. The postoperative course was uneventful. Two months later, the functional outcome was satisfactory and a plain film showed good bony alignment without resorption (Figure 1(B)). The incidence of non-union is about 6% of all phalangeal fractures (Van Oosterom et al., 2001). Reconstruction of a recurrent phalangeal nonunion is difficult because repeated bone grafting and soft tissue manipulation compromises the local tissue circulation and results in severe fibrosis. The common methods of treating this situation include autologous bone graft, free vascularized bone graft and artificial substitutes (Findikcioglu et al., 2009). A vascularized bone graft is better than an autologous bone graft because of its good circulation, but has several limitations, such as the long operating time, sacrifice of a digital artery and donor site morbidity (Dimitriou et al., 2005). Platelet glue, first described by Marx (2004), has proven effects on collagen synthesis and angiogenesis, which facilitate wound healing and bone union. When used in bone reconstruction, it provides some adhesion for the consolidation of corticocancellous bone in the bone defect. Autologous platelet glue has the advantages that there are no risks of blood transfusion reaction or disease transmission. Autologous platelet glue mixed with autologous bone graft may be an alternative in reconstruction of the difficult phalangeal non-union with a bone deficit. Acknowledgement Civilian Administration Division of Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Conflict of interests None declared.
References Dimitriou R, Dahabreh Z, Katsoulis E, Matthews SJ, Branfoot T, Giannoudis PV. Application of recombinant BMP-7 on persistent upper and lower limb non-unions. Injury. 2005, 36: S51–9. Findikcioglu K, Findikcioglu F, Yavuzer R, Elmas C, Atabay K. Effect of platelet-rich plasma and fibrin glue on healing of critical-size calvarial bone defects. J Craniofac Surg. 2009, 20: 34–40. Marx RE. Platelet-rich plasma: evidence to support its use. J Oral Maxillofac Surg. 2004, 62: 489–96.
Van Oosterom FJ, Brete GJ, Ozdemir C, Hovius SE. Treatment of phalangeal fractures in severely injured hands. J Hand Surg Br. 2001, 26: 108–11.
C.-T. Lin, S.-G. Chen and S.-C. Chang Division of Plastic and Reconstructive Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. Corresponding author:
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Rupture of the flexor pollicis longus tendon in a child treated by twostage tendon transfer Dear Sir, An 8-year-old, right-handed boy was referred to us from a local orthopaedic clinic with a diagnosis of trigger thumb. Two years previously, it had been noted that he had difficulty writing when he started elementary school, but his parents had thought this was not unusual in a young child. More recently, they noticed that he could not flex the interphalangeal (IP) joint of his right thumb. He had no significant past medical history and no history of trauma. Examination of his right hand showed that the crease on the palmar surface of the IP joint of the thumb was indistinct. He was unable to actively flex the IP joint. There was no tenodesis effect of the flexor pollicis longus (FPL) tendon. The other extrinsic and intrinsic muscles of the hand had normal strength, and hand sensation was normal. Hand radiographs did not show skeletal abnormalities. Magnetic resonance imaging showed that the distal insertion of the FPL was relatively hypertrophied, and that the proximal portion of the distal stump was hyperintense on T1- and T2-weighted images, and tapered off at the base of the thumb. In the proximal forearm only an atrophied remnant of the FPL tendon was detected. We diagnosed a spontaneous rupture of the FPL tendon at the metacarpophalangeal (MCP) joint of the right thumb. A zigzag incision was made on the flexor surface of the thumb. The stout remnant of the FPL tendon was strongly adherent to the A1, Av, oblique, and A2 pulleys, tapering off at the MCP joint, which suggested that the condition was not congenital (Figure 1). We could not identify the proximal stump of the FPL
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The Journal of Hand Surgery (Eur) 40(4)
Figure 1. During the first-stage surgery, the remnants of the FPL tendon are observed to adhere to the flexor sheath and taper off at the metacarpophalangeal joint.
tendon in the vertical incision in the distal forearm. We therefore carried out a staged tendon reconstruction using a 4 mm Hunter tendon implant. Three months after the first-stage surgery, the flexor digitorum superficialis tendon of the ring finger was transferred as a motor unit, without the need for a free graft. A tendon-to-tendon technique, rather than the tendon-to-bone technique, was used to avoid damaging the growth plate of the distal phalanx. The thumb was immobilized in a thumb spica cast for 3 weeks, followed by immobilization in a splint that could be removed for bathing. Active exercises of the IP joint were started at 6 weeks after surgery, and progressive resisted hand-strengthening exercises were started at 2 months. The patient was able to actively flex the IP joint of his right thumb independently of the ring finger at only 2 weeks after surgery, when we renewed the cast. At 2 years after the second-stage surgery, active range of motion of the IP and MCP joint was almost the same in both hands. He did not complain of any difficulty with thumb function in his daily life. It has been reported that tendons rarely rupture if they have an adequate blood supply (McMaster, 1933). The cause of tendon rupture is uncertain in our case. Adduction of the thumb causes acute kinking of the tendon, which may be injured by a pulley or against a sesamoid bone (Patel, 1966). The child did not yet have sesamoid bones, but the narrow tunnel at the A1 pulley may have constricted the tendon. A relatively avascular watershed area overlying the MCP joint has been described (Hergenroeder et al., 1982). This regional anatomy seems a
predisposing factor to rupture, along with some external factors. Rupture secondary to trigger thumb seems unlikely and the patient had no apparent congenital anomaly or predisposition to rupture of the FPL tendon. Late secondary rupture of the FPL tendon may occur after an almost forgotten history of trauma, but there was no scar to suggest this, although if a penetrating injury occurred early in life, any scar may have faded. We suspect that the rupture occurred during infancy, because there was no distal thumb crease. The management of a late tendon rupture in childhood is difficult. Early mobilization for a young patient is unsafe. We carried out a two-stage surgical procedure using a silicone rod to obtain a smooth pathway for the tendon transfer. The sheath formed around the rod allowed the tendon transfer to glide without adhesions (Oka, 2000). Immobilization for 3 weeks after the tendon transfer was safe for a child with good gliding of the tendon. Careful follow-up is needed because the tendon transfer was done while still skeletally immature. Conflict of interests None declared.
Ethical approval This manuscript is approved by the committee on ethics of Mitsubishi Kyoto Hospital.
References Hergenroeder PT, Gelberman RH, Akeson WH. The vascularity of the flexor pollicis longus tendon. Clin Orthop Related Res. 1982, 162: 298–303. McMaster PE. Tendon and muscle ruptures. Clinical and experimental studies on the causes and location of subcutaneous ruptures. J Bone Joint Surg Am. 1933, 15: 705–22. Oka Y. Reconstruction of the flexor pollicis longus tendon ruptured, but untreated, during infancy. Tokai J Exp Clin Med. 2000, 25: 23–6. Patel AP. Trigger thumb in infancy. Postgrad Med J. 1966, 42: 512–3.
H. Yamamoto MD PhD and S. Fujita MD Department of Orthopaedic Surgery, Mitsubishi Kyoto Hospital, Kyoto, Japan. Corresponding author:
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