Case Report
European Journal of Trauma and Emergency Surgery
Rupture of Flexor Pollicis Longus Tendon: A Complication of Volar Locking Plating of the Distal Radius Aysha Sethunathan Rajeev, Shanaka Sreverthana, John Harrison1
Abstract We report an unusual case of complete rupture of the flexor pollicis longus tendon following volar locking plating for a distal radius fracture. We believe that the prominence of a distal locking screw head predisposed to the rupture of the tendon. We highlight that correctly attaching the distal locking screws to the plate is essential for obtaining the correct biomechanics of the device and preventing flexor tendon rupture. Key Words Biomechanics of fracture fixation Æ Osteosynthesis Æ Reconstructive surgery Æ Wrist Eur J Trauma Emerg Surg 2010;36:385–7 DOI 10.1007/s00068-009-9021-4
Introduction Complete rupture of the flexor pollicis longus (FPL) tendon is an uncommon complication following volar plating of distal radius fractures. The tendon is at risk of fraying, and subsequent rupture has been reported in the literature [1, 2, 5]. The prominence of screw heads is one of the most important factors attributed to this complication [6, 7]. It has also been suggested that repair of the pronator quadratus after a volar Henry’s approach reduces the chance of FPL tendon attrition. Constant irritation from the prominent screw heads leads to synovitis, fraying, and the eventual rupture of the FPL tendon [6]. We report a complete rupture of the flexor pollicis longus tendon following distal radius volar plating
1
using a locking plate for a distal radius fracture. There are no previous reports of this in the literature.
Case Report A 61-year-old lady fractured her left distal radius following a simple fall. She was a secretary and her past medical history included hypertension. Radiographs showed a communicated extra-articular fracture of the left distal radius. The patient underwent open reduction and internal fixation using a distal radius volar locking plate (Acumed). The postoperative period was uneventful and the fracture healed radiologically at six weeks. She was eventually discharged from the clinic after three months with slightly reduced wrist extension but with other movements preserved. The patient came back to the clinic seven months later with swelling and pain in the left wrist. Examination revealed swelling and tenderness over the flexor tendons proximal to her wrist. The patient was reassured and discharged home with a follow-up appointment three months later. The patient returned to the clinic earlier after two weeks with an inability to flex the thumb. The clinical examination revealed a complete rupture of the FPL tendon with no active thumb interphalangeal joint flexion. The radiograph taken at this time showed that one or more of the distal locking screw heads were prominent (Figure 1a, b). An exploration of the wrist was performed and a complete rupture of the FPL tendon was confirmed (Figure 2). The locking plate was removed. A tendon transfer of the ring finger flexor digitorum superficialis to the FPL was performed (Figure 3). At the three-
Trauma and Orthopaedics, Queen Elizabeth Hospital, Sheriff Hill, Gateshead, Tyne and Wear, NE9 6SX, UK.
Received: January 28, 2009; revision accepted: August 1, 2009; Published Online: September 11, 2009
Eur J Trauma Emerg Surg 2010 Æ No. 4 Ó URBAN & VOGEL
385
Rajeev AS, et al. Rupture of Flexor Pollicis Longus Tendon
Figure 1. a Radiograph showing a prominent screw head (arrow head). b Operative picture showing a prominent screw head (arrow head).
month follow-up the patient had regained full thumb flexion and opposition. She works as a typist and had returned to full duties.
Discussion Rupture of flexor tendons after distal radius plating is rare. There are reports of the rupture of the flexor
pollicis longus tendon due to mechanical attrition against the prominent distal edge of the plate [1–5]. In all of these reports the plate had been placed too distal. It is important to emphasize the watershed line as a landmark to prevent the plate being placed too proximal. In some cases, even if the plate is initially placed correctly, the collapse of the fracture makes the plate more prominent [1]. Scott and Duncan reported an isolated FPL rupture as a complication after osteosynthesis of the distal radius using a T-plate [3]. They suggested that a diagnosis of FPL rupture should be considered in any patient who presents with pain and has undergone a previous operation of the wrist, especially involving metalwork insertion [3]. Cross and Schmidt [4] reported fraying and rupture of the FPL tendon, despite placing the plate in the correct position and flush to the cortex. They also emphasized that the patient should be informed about the removal of the plate if necessary. Klug et al. [5] suggested that ruptures of FPL tendons occur due to physiologically abnormal tendons, improperly placed plates, and prominent and sharp edges of plates and/or screws. Heim and Pfeiffer [6] described abrasion and synovitis caused by a prominent screw that was used to fix a volar plate. Drobetz and Kutscha–Lissbergb [7] reported their experiences of FPL rupture due to prominent screw heads in a custom-made fixed-angle volar plate of their own design. Jupiter et al. [8] suggested that the plate should be covered with the pronator quadratus muscle to minimize any tendon impingement. Yamazaki et al. [9] recently identified two causes of tendon ruptures by a volar plate; one is due to the distal edge of the plate, and the second is due to the sharp edge of a screw head. We have performed over 50 volar locking plate fixations for distal radial fractures. This is our only case of a flexor tendon rupture. In this case, the plate was placed at the correct level and was flush to the cortex. However, a distal locking screw head was left prominent which predisposed to the tendon rupture. As a
Figure 2. Picture showing the complete rupture of the FPL tendon. A, FPL tendon; B, FDS tendon.
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Eur J Trauma Emerg Surg 2010 Æ No. 4
Rajeev AS, et al. Rupture of Flexor Pollicis Longus Tendon
Figure 3. Postoperative picture showing FDS to FPL reconstruction (arrow head).
result of the tendon rupture, the patient required further surgery and extensive physiotherapy to achieve a good result. In this case, the pronator quadratus muscle was not repaired, which may have protected the flexor tendons. It is our normal practice to repair the pronator quadratus, and this can usually be achieved if the muscle has been elevated from its most radial attachment. However, in some cases the pronator quadratus muscle is torn when the fracture occurs and the muscle cannot be repaired after plate fixation. In these cases it has not been our experience that this has led to irritation of the flexor tendons, and we do not believe that this is an important factor in the prevention of flexor tendon rupture. Modern volar locking plates are low profile and the distal screw heads are below the surface of the plate when fully seated. We believe that the more important factor in the prevention of flexor tendon rupture is ensuring the correct placement of the locking plate and the full insertion of the locking screws. Although various types of volar locking distal radius plates are available, the placement on the bone is dictated by the fracture configuration. There is a theoretical line marking the most volar aspect of the volar margin of the radius that is distal to the pronator quadratus line and is covered by the volar capsule, and is called the watershed line. Any hardware placed volar to this line would function as a fulcrum for the flexor tendons, especially during power grip, potentially risking tenosynovitis or rupture. Therefore, it is important to ensure that the volar plate does not project above this line. If the locking screw cannot be screwed fully into the plate, we recommend that either the hole should be left unfilled or the whole screw should be removed and
Eur J Trauma Emerg Surg 2010 Æ No. 4
a further screw placed through the plate into the hole already drilled in the distal radius. The locking plate acts a fixed-angle device that buttresses the subchondral bone of the distal radius. If the distal locking screw is not fully attached into the plate the fixation is likely to fail. If a prominent screw head is found on postoperative radiographs, possibly due to the screw backing out from the plate, we recommend the removal of the plate and screws once the fracture has healed if there is any evidence of flexor tendon irritation.
Conflict of interest statement The authors declare that there is no actual or potential conflict of interest in relation to this article.
References 1.
2. 3.
4.
5.
6. 7.
8.
9.
Bell JSP, Wollstein R, Citron ND. Rupture of flexor pollicis longus tendon – a complication of volar plating of the distal radius. J Bone Joint Surg 1998;80:225–6. Koo SC, Ho ST. Delayed rupture of flexor pollicis tendon after volar plating of the distal radius. J Hand Surgery 2006;11:67–70. Duncan SFM, Weiland AJ. Delayed rupture of flexor pollicis tendon after routine volar placement of a T-plate on the distal radius. Am J Orthop 2007;36:669–70. Cross AW , Schmidt CC. Flexor tendon injuries following locked volar plating of distal radius fractures. J Hand Surg 2008;33A:164–7. Klug RA, Press CM, Gonzalez MH. Rupture of the flexor pollicis longus tendon after volar fixed-angle plating of a distal radius fracture: a case report. J Hand Surg 2007;32A:984–8. Heim U, Pfeiffer KM. Internal fixation of small fractures, 3rd edn. Berlin: Springer, 1988:165. Drobetz H, Kutscha-Lissberg E. Osteosynthesis of distal radius fractures with a volar locking screw plate system. Int Orthop 2003;27:1–6. Fernandez DL, Jupiter JB, eds. Surgical techniques. In: Fractures of the distal radius: a practical approach to management. New York: Springer, 1995:67–102. Yamazaki H, Hallori Y, Doi K. Delayed ruptures of flexor tendons caused by protrusion of a screw head of a volar plate for distal radius fracture: a case report. Hand Surg 2008;13:27–9.
Address for Correspondence Rajeev Aysha Sethunathan Trauma and Orthopaedics Queen Elizabeth Hospital Sheriff Hill, Gateshead Tyne and Wear NE9 6SX, UK Phone (+44/19) 1482 0000 e-mail: [email protected]
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European Journal of Trauma and Emergency Surgery
Rupture of Flexor Pollicis Longus Tendon: A Complication of Volar Locking Plating of the Distal Radius Aysha Sethunathan Rajeev, Shanaka Sreverthana, John Harrison1
Abstract We report an unusual case of complete rupture of the flexor pollicis longus tendon following volar locking plating for a distal radius fracture. We believe that the prominence of a distal locking screw head predisposed to the rupture of the tendon. We highlight that correctly attaching the distal locking screws to the plate is essential for obtaining the correct biomechanics of the device and preventing flexor tendon rupture. Key Words Biomechanics of fracture fixation Æ Osteosynthesis Æ Reconstructive surgery Æ Wrist Eur J Trauma Emerg Surg 2010;36:385–7 DOI 10.1007/s00068-009-9021-4
Introduction Complete rupture of the flexor pollicis longus (FPL) tendon is an uncommon complication following volar plating of distal radius fractures. The tendon is at risk of fraying, and subsequent rupture has been reported in the literature [1, 2, 5]. The prominence of screw heads is one of the most important factors attributed to this complication [6, 7]. It has also been suggested that repair of the pronator quadratus after a volar Henry’s approach reduces the chance of FPL tendon attrition. Constant irritation from the prominent screw heads leads to synovitis, fraying, and the eventual rupture of the FPL tendon [6]. We report a complete rupture of the flexor pollicis longus tendon following distal radius volar plating
1
using a locking plate for a distal radius fracture. There are no previous reports of this in the literature.
Case Report A 61-year-old lady fractured her left distal radius following a simple fall. She was a secretary and her past medical history included hypertension. Radiographs showed a communicated extra-articular fracture of the left distal radius. The patient underwent open reduction and internal fixation using a distal radius volar locking plate (Acumed). The postoperative period was uneventful and the fracture healed radiologically at six weeks. She was eventually discharged from the clinic after three months with slightly reduced wrist extension but with other movements preserved. The patient came back to the clinic seven months later with swelling and pain in the left wrist. Examination revealed swelling and tenderness over the flexor tendons proximal to her wrist. The patient was reassured and discharged home with a follow-up appointment three months later. The patient returned to the clinic earlier after two weeks with an inability to flex the thumb. The clinical examination revealed a complete rupture of the FPL tendon with no active thumb interphalangeal joint flexion. The radiograph taken at this time showed that one or more of the distal locking screw heads were prominent (Figure 1a, b). An exploration of the wrist was performed and a complete rupture of the FPL tendon was confirmed (Figure 2). The locking plate was removed. A tendon transfer of the ring finger flexor digitorum superficialis to the FPL was performed (Figure 3). At the three-
Trauma and Orthopaedics, Queen Elizabeth Hospital, Sheriff Hill, Gateshead, Tyne and Wear, NE9 6SX, UK.
Received: January 28, 2009; revision accepted: August 1, 2009; Published Online: September 11, 2009
Eur J Trauma Emerg Surg 2010 Æ No. 4 Ó URBAN & VOGEL
385
Rajeev AS, et al. Rupture of Flexor Pollicis Longus Tendon
Figure 1. a Radiograph showing a prominent screw head (arrow head). b Operative picture showing a prominent screw head (arrow head).
month follow-up the patient had regained full thumb flexion and opposition. She works as a typist and had returned to full duties.
Discussion Rupture of flexor tendons after distal radius plating is rare. There are reports of the rupture of the flexor
pollicis longus tendon due to mechanical attrition against the prominent distal edge of the plate [1–5]. In all of these reports the plate had been placed too distal. It is important to emphasize the watershed line as a landmark to prevent the plate being placed too proximal. In some cases, even if the plate is initially placed correctly, the collapse of the fracture makes the plate more prominent [1]. Scott and Duncan reported an isolated FPL rupture as a complication after osteosynthesis of the distal radius using a T-plate [3]. They suggested that a diagnosis of FPL rupture should be considered in any patient who presents with pain and has undergone a previous operation of the wrist, especially involving metalwork insertion [3]. Cross and Schmidt [4] reported fraying and rupture of the FPL tendon, despite placing the plate in the correct position and flush to the cortex. They also emphasized that the patient should be informed about the removal of the plate if necessary. Klug et al. [5] suggested that ruptures of FPL tendons occur due to physiologically abnormal tendons, improperly placed plates, and prominent and sharp edges of plates and/or screws. Heim and Pfeiffer [6] described abrasion and synovitis caused by a prominent screw that was used to fix a volar plate. Drobetz and Kutscha–Lissbergb [7] reported their experiences of FPL rupture due to prominent screw heads in a custom-made fixed-angle volar plate of their own design. Jupiter et al. [8] suggested that the plate should be covered with the pronator quadratus muscle to minimize any tendon impingement. Yamazaki et al. [9] recently identified two causes of tendon ruptures by a volar plate; one is due to the distal edge of the plate, and the second is due to the sharp edge of a screw head. We have performed over 50 volar locking plate fixations for distal radial fractures. This is our only case of a flexor tendon rupture. In this case, the plate was placed at the correct level and was flush to the cortex. However, a distal locking screw head was left prominent which predisposed to the tendon rupture. As a
Figure 2. Picture showing the complete rupture of the FPL tendon. A, FPL tendon; B, FDS tendon.
386
Eur J Trauma Emerg Surg 2010 Æ No. 4
Rajeev AS, et al. Rupture of Flexor Pollicis Longus Tendon
Figure 3. Postoperative picture showing FDS to FPL reconstruction (arrow head).
result of the tendon rupture, the patient required further surgery and extensive physiotherapy to achieve a good result. In this case, the pronator quadratus muscle was not repaired, which may have protected the flexor tendons. It is our normal practice to repair the pronator quadratus, and this can usually be achieved if the muscle has been elevated from its most radial attachment. However, in some cases the pronator quadratus muscle is torn when the fracture occurs and the muscle cannot be repaired after plate fixation. In these cases it has not been our experience that this has led to irritation of the flexor tendons, and we do not believe that this is an important factor in the prevention of flexor tendon rupture. Modern volar locking plates are low profile and the distal screw heads are below the surface of the plate when fully seated. We believe that the more important factor in the prevention of flexor tendon rupture is ensuring the correct placement of the locking plate and the full insertion of the locking screws. Although various types of volar locking distal radius plates are available, the placement on the bone is dictated by the fracture configuration. There is a theoretical line marking the most volar aspect of the volar margin of the radius that is distal to the pronator quadratus line and is covered by the volar capsule, and is called the watershed line. Any hardware placed volar to this line would function as a fulcrum for the flexor tendons, especially during power grip, potentially risking tenosynovitis or rupture. Therefore, it is important to ensure that the volar plate does not project above this line. If the locking screw cannot be screwed fully into the plate, we recommend that either the hole should be left unfilled or the whole screw should be removed and
Eur J Trauma Emerg Surg 2010 Æ No. 4
a further screw placed through the plate into the hole already drilled in the distal radius. The locking plate acts a fixed-angle device that buttresses the subchondral bone of the distal radius. If the distal locking screw is not fully attached into the plate the fixation is likely to fail. If a prominent screw head is found on postoperative radiographs, possibly due to the screw backing out from the plate, we recommend the removal of the plate and screws once the fracture has healed if there is any evidence of flexor tendon irritation.
Conflict of interest statement The authors declare that there is no actual or potential conflict of interest in relation to this article.
References 1.
2. 3.
4.
5.
6. 7.
8.
9.
Bell JSP, Wollstein R, Citron ND. Rupture of flexor pollicis longus tendon – a complication of volar plating of the distal radius. J Bone Joint Surg 1998;80:225–6. Koo SC, Ho ST. Delayed rupture of flexor pollicis tendon after volar plating of the distal radius. J Hand Surgery 2006;11:67–70. Duncan SFM, Weiland AJ. Delayed rupture of flexor pollicis tendon after routine volar placement of a T-plate on the distal radius. Am J Orthop 2007;36:669–70. Cross AW , Schmidt CC. Flexor tendon injuries following locked volar plating of distal radius fractures. J Hand Surg 2008;33A:164–7. Klug RA, Press CM, Gonzalez MH. Rupture of the flexor pollicis longus tendon after volar fixed-angle plating of a distal radius fracture: a case report. J Hand Surg 2007;32A:984–8. Heim U, Pfeiffer KM. Internal fixation of small fractures, 3rd edn. Berlin: Springer, 1988:165. Drobetz H, Kutscha-Lissberg E. Osteosynthesis of distal radius fractures with a volar locking screw plate system. Int Orthop 2003;27:1–6. Fernandez DL, Jupiter JB, eds. Surgical techniques. In: Fractures of the distal radius: a practical approach to management. New York: Springer, 1995:67–102. Yamazaki H, Hallori Y, Doi K. Delayed ruptures of flexor tendons caused by protrusion of a screw head of a volar plate for distal radius fracture: a case report. Hand Surg 2008;13:27–9.
Address for Correspondence Rajeev Aysha Sethunathan Trauma and Orthopaedics Queen Elizabeth Hospital Sheriff Hill, Gateshead Tyne and Wear NE9 6SX, UK Phone (+44/19) 1482 0000 e-mail: [email protected]
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