HAND SURGERY COMPLICATIONS
Volar Carpal Subluxation Following Lunate Facet Fracture Alison Kitay, MD, Chaitanya Mudgal, MD THE PATIENT A 27-year-old right-handed man presented with pain and limited motion in the left wrist and forearm after surgical treatment for an intra-articular volar marginal distal radius fracture with a lunate facet fragment and volar carpal subluxation (Fig. 1). He was treated at an outside hospital with volar plate fixation and pinning of the distal radioulnar joint (Fig. 2). The pin was removed 4 weeks after surgery and he was started on rehabilitative exercises. THE COMPLICATION Two weeks after rehabilitation was initiated, he had no forearm supination. Radiographs taken 6 weeks postoperatively revealed loss of fixation of the distal radius fracture distally with volar subluxation of the carpus (Fig. 3). In addition, there was destruction of the ulnar head radially. He had persistent wrist pain, no forearm supination, only 30 pronation, 15 wrist extension, and 25 wrist flexion. ADVERSE EFFECTS Malunions of the volar lunate facet and volar subluxation of the carpus can lead to decreased motion, impaired function, pain, and ultimately arthrosis. TREATMENT The patient was taken to the operating room and the prior volar incision was extended into an extended carpal tunnel approach. The transverse carpal ligament
From the Department of Hand and Upper Extremity Surgery, Massachusetts General Hospital, Boston, MA. Received for publication March 12, 2014; accepted in revised form April 4, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Alison Kitay, MD, Department of Hand and Upper Extremity Surgery, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115; e-mail: [email protected]. 0363-5023/14/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.04.027
was released and the proximal dissection was carried out ulnar to the palmaris longus tendon to gain access to the volar ulnar corner of the distal radius. The volar lunate facet was completely displaced from under the plate in an ulnar-volar direction. After plate removal, the lunate facet fracture site was redeveloped at the proximal ulnar corner of the fragment at the ulnar aspect of the distal radius metaphysis. The boomerang-shaped lunate facet fragment was mobilized, reduced, and provisionally pinned in place and cancellous allograft bone chips were placed in the malunion site. Once the fragment was reduced, forearm supination improved from 0 to 60 . An intermediate column 2.4-mm variable-angle locking plate (Synthes, Paoli, PA) was used to fix the fragment as a buttress. Proper radiocarpal alignment was restored. Because the other components of the original fracture were healed, no other fixation was performed. We partially resected the ulnar head and performed an extensor carpi ulnaris tenodesis. The patient’s wrist was immobilized for 6 weeks postoperatively in a short-arm cast before starting rehabilitation. At the time of the latest follow-up, the patient maintained appropriate alignment of the radiocarpal joint. He had near full pronation and supination, 65 wrist extension, and 45 wrist flexion, and he was still making range of motion gains with therapy (Fig. 4). There was no evidence of tendon irritation from the plate, and the pain had resolved. LITERATURE REVIEW Volar lunate facet fractures often present with subtle radiographic findings that may be missed on initial presentation. Inadequate fixation of the volar ulnar corner during operative treatment of distal radius fractures can lead to loss of reduction and volar subluxation of the carpus. Fixation of this critical fragment can be challenging because of the anatomy of the volar ulnar corner. The lunate facet serves as the attachment site for the volar radiolunate ligament.1,2 The facet is more prominent volarly than the remainder of the distal radius by about 3 mm.2
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1
2
VOLAR LUNATE FACET FRACTURES
FIGURE 1: Injury films including A posteroanterior (PA), B lateral, and C oblique views of the wrist demonstrating the volar lunate facet fragment and initial volar carpal subluxation.
FIGURE 2: A Intraoperative PA, B lateral, and C and oblique x-ray films from the initial surgery demonstrating only 1 point of fixation into the critical volar ulnar corner.
are the first step in evaluation. On the lateral view, the teardrop (Fig. 5) represents the volar lunate facet and the teardrop angle (Fig. 5) measures displacement of the volar lunate facet fragment.4 The angle is formed between a line drawn along the axis of the radial shaft and a line along the axis of the teardrop, parallel to the subchondral bone of the volar rim. The normal teardrop angle is about 70 . If the angle is less than 45 , this suggests marked dorsal tilt of the volar rim.4 The teardrop angle has high interobserver and intra-observer reliability, and it has been associated with articular gap and stepoff on computed tomography.5 Preoperative computed tomography scans are also helpful for delineating fracture fragments and identifying fragment morphology.6
Because of this volar prominence, standard volar distal radius locking plates do not typically fit well over the volar ulnar corner. For this reason, loss of reduction and volar subluxation of the carpus is of particular concern in patients treated with monoblock fixation for fractures involving the lunate facet. If left untreated, malunions of the volar lunate facet and volar subluxation of the carpus can lead to decreased function, decreased wrist range of motion, arthrosis, and pain. Loss of forearm supination and wrist extension are frequent early problems among these patients.3 Loss of supination is not well tolerated and can have a significant impact on function. The first key in treatment is initial recognition of the critical volar lunate facet fragment. Plain radiographs J Hand Surg Am.
r
Vol. -, - 2014
VOLAR LUNATE FACET FRACTURES
3
FIGURE 3: A Plain PA and B lateral radiographs taken 6 weeks after surgery demonstrating loss of reduction with volar subluxation of the carpus.
Understanding the fragment geometry is critical for preoperative planning and aids in decision making about fixation techniques and optimal hardware placement. Isolated lunate facet fragments can be fixed with linear columnar plates or a judiciously placed cannulated screw with a washer, which can serve as a 1-hole plate (Fig. 6A). The boomerang-shaped fragment geometry that is common with lunate facet fractures is not amenable to monoblock fixation using standard volar locking plates. The patient presented here had a boomerang-shaped fragment as part of the volar Barton fracture that was treated with a volar locking plate in isolation, and the volar lunate facet fragment displaced with loss of fixation and volar carpal subluxation. When noted as part of a complex distal radius fracture pattern, careful positioning of a monoblock volar plate on the J Hand Surg Am.
ulnar-most aspect of the distal radius can allow for at least 2 points of fixation into the lunate facet fragment, particularly if variable angle screws are used. Volar plate fixation can also be augmented by adding a single cannulated screw with a washer to secure the lunate facet fragment (Fig. 6B). Fragment-specific fixation implants,7 low-profile plates, and wire loop fixation8 are other potential fixation options. Some lunate facet fractures are avulsion-type fractures that occur as a component of a radiocarpal fracture-dislocation. These fragments tend to be small. Fixation is usually achieved with wire loop techniques, suture anchors, or mini-fragment screws, although screw fixation can be challenging and fraught with risk of fragmentation. When patients present with loss of fixation of the volar lunate facet fragment, as was the case for r
Vol. -, - 2014
4
VOLAR LUNATE FACET FRACTURES
FIGURE 4: A Plain radiographs and B clinical pictures demonstrating improved radiographic alignment and clinical range of motion after revision open reduction internal fixation of the lunate facet fragment.
J Hand Surg Am.
r
Vol. -, - 2014
VOLAR LUNATE FACET FRACTURES
5
FIGURE 5: A The teardrop is outlined with the dotted line and B the teardrop angle is drawn.
our patient, they typically have volar subluxation of the carpus and loss of supination. During revision open reduction internal fixation, the preferred interval for access to the fragment is between the flexor tendons and the ulnar neurovascular bundle.3 The volar lunate facet fragment can usually be mobilized by starting at the most proximal ulnar cortical edge, where the former fracture site is often visible even several weeks after injury. This is a critical detail to remember because the anatomy is substantially altered and can be confusing. This corner can be used to redevelop the boomerangshaped fracture fragment. The 10 inclined lateral radiograph is helpful to assess adequate reduction intraoperatively.3 Once reduced, fixation using plates or 1 of the techniques mentioned above can improve motion and function.1,3 Given the distal extension of the volar lunate facet fragment, any fixation applied to this fragment will appear to be intra-articular on the posteroanterior radiograph but should not be a cause for concern as long as the lateral radiograph confirms appropriate hardware placement. When distal plate placement is planned, we recommend performing J Hand Surg Am.
a carpal tunnel release and monitoring for postoperative signs of flexor tendon irritation necessitating removal of hardware.9 Corrective osteotomy also achieves good results for patients who present too late for revision open reduction internal fixation. In a series of 13 patients treated with intra-articular osteotomies for isolated malunions of the volar lunate facet, Ruch et al3 demonstrated substantial improvements in range of motion, grip strength, and Disabilities of the Arm, Shoulder, and Hand questionnaire scores. PREVENTION To prevent the complication of volar carpal subluxation, we recommend (1) preoperative and intraoperative clinical and radiographic vigilance to visualize the volar lunate facet fragment and (2) adequate fixation of the volar lunate facet fragment. Because of the irregular anatomy of this fragment, adequate fixation is difficult to achieve using monoblock fixation with a volar plate. Special attention to plate placement and the use of alternative techniques r
Vol. -, - 2014
6
VOLAR LUNATE FACET FRACTURES
FIGURE 6: A Lunate facet fragment reduced and secured with a cannulated screw and washer. B Final fixation construct with volar locking plate and cannulated screw and washer.
to augment fixation of the volar ulnar corner can prevent loss of fixation and the sequelae of malunions. Primary fixation of nascent malunions or corrective osteotomy has been shown to improve motion and function in these circumstances. J Hand Surg Am.
REFERENCES 1. Harness NG, Jupiter JB, Orbay JL, Raskin KB, Fernandez DL. Loss of fixation of the volar lunate facet fragment in fractures of the distal part of the radius. J Bone Joint Surg Am. 2004;86(9): 1900e1908.
r
Vol. -, - 2014
VOLAR LUNATE FACET FRACTURES
6. Harness NG, Ring D, Zurakowski D, Harris GJ, Jupiter JB. The influence of three-dimensional computed tomography reconstructions on the characterization and treatment of distal radial fractures. J Bone Joint Surg Am. 2006;88(6):1315e1323. 7. Saw N, Roberts C, Cutbush K, Hodder M, Couzens G, Ross M. Early experience with the TriMed fragment-specific fracture fixation system in intraarticular distal radius fractures. J Hand Surg Eur Vol. 2008;33(1):53e58. 8. Chin KR, Jupiter JB. Wire-loop fixation of volar displaced osteochondral fractures of the distal radius. J Hand Surg Am. 1999;24(3):525e533. 9. Kitay A, Swanstrom M, Schreiber JJ, et al. Volar plate position and flexor tendon rupture following distal radius fracture fixation. J Hand Surg Am. 2013;38(6):1091e1096.
2. Andermahr J, Lozano-Calderon S, Trafton T, Crisco JJ, Ring D. The volar extension of the lunate facet of the distal radius: a quantitative anatomic study. J Hand Surg Am. 2006;31(6):892e895. 3. Ruch DS, Wray WH III, Papadonikolakis A, Richard MJ, Leversedge FJ, Goldner RD. Corrective osteotomy for isolated malunion of the palmar lunate facet in distal radius fractures. J Hand Surg Am. 2010;35(11):1779e1786. 4. Medoff RJ. Essential radiographic evaluation for distal radius fractures. Hand Clin. 2005;21(3):279e288. 5. Fujitani R, Omokawa S, Iida A, Santo S, Tanaka Y. Reliability and clinical importance of teardrop angle measurement in intra-articular distal radius fracture. J Hand Surg Am. 2012;37(3): 454e459.
J Hand Surg Am.
7
r
Vol. -, - 2014
Volar Carpal Subluxation Following Lunate Facet Fracture Alison Kitay, MD, Chaitanya Mudgal, MD THE PATIENT A 27-year-old right-handed man presented with pain and limited motion in the left wrist and forearm after surgical treatment for an intra-articular volar marginal distal radius fracture with a lunate facet fragment and volar carpal subluxation (Fig. 1). He was treated at an outside hospital with volar plate fixation and pinning of the distal radioulnar joint (Fig. 2). The pin was removed 4 weeks after surgery and he was started on rehabilitative exercises. THE COMPLICATION Two weeks after rehabilitation was initiated, he had no forearm supination. Radiographs taken 6 weeks postoperatively revealed loss of fixation of the distal radius fracture distally with volar subluxation of the carpus (Fig. 3). In addition, there was destruction of the ulnar head radially. He had persistent wrist pain, no forearm supination, only 30 pronation, 15 wrist extension, and 25 wrist flexion. ADVERSE EFFECTS Malunions of the volar lunate facet and volar subluxation of the carpus can lead to decreased motion, impaired function, pain, and ultimately arthrosis. TREATMENT The patient was taken to the operating room and the prior volar incision was extended into an extended carpal tunnel approach. The transverse carpal ligament
From the Department of Hand and Upper Extremity Surgery, Massachusetts General Hospital, Boston, MA. Received for publication March 12, 2014; accepted in revised form April 4, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Alison Kitay, MD, Department of Hand and Upper Extremity Surgery, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115; e-mail: [email protected]. 0363-5023/14/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.04.027
was released and the proximal dissection was carried out ulnar to the palmaris longus tendon to gain access to the volar ulnar corner of the distal radius. The volar lunate facet was completely displaced from under the plate in an ulnar-volar direction. After plate removal, the lunate facet fracture site was redeveloped at the proximal ulnar corner of the fragment at the ulnar aspect of the distal radius metaphysis. The boomerang-shaped lunate facet fragment was mobilized, reduced, and provisionally pinned in place and cancellous allograft bone chips were placed in the malunion site. Once the fragment was reduced, forearm supination improved from 0 to 60 . An intermediate column 2.4-mm variable-angle locking plate (Synthes, Paoli, PA) was used to fix the fragment as a buttress. Proper radiocarpal alignment was restored. Because the other components of the original fracture were healed, no other fixation was performed. We partially resected the ulnar head and performed an extensor carpi ulnaris tenodesis. The patient’s wrist was immobilized for 6 weeks postoperatively in a short-arm cast before starting rehabilitation. At the time of the latest follow-up, the patient maintained appropriate alignment of the radiocarpal joint. He had near full pronation and supination, 65 wrist extension, and 45 wrist flexion, and he was still making range of motion gains with therapy (Fig. 4). There was no evidence of tendon irritation from the plate, and the pain had resolved. LITERATURE REVIEW Volar lunate facet fractures often present with subtle radiographic findings that may be missed on initial presentation. Inadequate fixation of the volar ulnar corner during operative treatment of distal radius fractures can lead to loss of reduction and volar subluxation of the carpus. Fixation of this critical fragment can be challenging because of the anatomy of the volar ulnar corner. The lunate facet serves as the attachment site for the volar radiolunate ligament.1,2 The facet is more prominent volarly than the remainder of the distal radius by about 3 mm.2
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1
2
VOLAR LUNATE FACET FRACTURES
FIGURE 1: Injury films including A posteroanterior (PA), B lateral, and C oblique views of the wrist demonstrating the volar lunate facet fragment and initial volar carpal subluxation.
FIGURE 2: A Intraoperative PA, B lateral, and C and oblique x-ray films from the initial surgery demonstrating only 1 point of fixation into the critical volar ulnar corner.
are the first step in evaluation. On the lateral view, the teardrop (Fig. 5) represents the volar lunate facet and the teardrop angle (Fig. 5) measures displacement of the volar lunate facet fragment.4 The angle is formed between a line drawn along the axis of the radial shaft and a line along the axis of the teardrop, parallel to the subchondral bone of the volar rim. The normal teardrop angle is about 70 . If the angle is less than 45 , this suggests marked dorsal tilt of the volar rim.4 The teardrop angle has high interobserver and intra-observer reliability, and it has been associated with articular gap and stepoff on computed tomography.5 Preoperative computed tomography scans are also helpful for delineating fracture fragments and identifying fragment morphology.6
Because of this volar prominence, standard volar distal radius locking plates do not typically fit well over the volar ulnar corner. For this reason, loss of reduction and volar subluxation of the carpus is of particular concern in patients treated with monoblock fixation for fractures involving the lunate facet. If left untreated, malunions of the volar lunate facet and volar subluxation of the carpus can lead to decreased function, decreased wrist range of motion, arthrosis, and pain. Loss of forearm supination and wrist extension are frequent early problems among these patients.3 Loss of supination is not well tolerated and can have a significant impact on function. The first key in treatment is initial recognition of the critical volar lunate facet fragment. Plain radiographs J Hand Surg Am.
r
Vol. -, - 2014
VOLAR LUNATE FACET FRACTURES
3
FIGURE 3: A Plain PA and B lateral radiographs taken 6 weeks after surgery demonstrating loss of reduction with volar subluxation of the carpus.
Understanding the fragment geometry is critical for preoperative planning and aids in decision making about fixation techniques and optimal hardware placement. Isolated lunate facet fragments can be fixed with linear columnar plates or a judiciously placed cannulated screw with a washer, which can serve as a 1-hole plate (Fig. 6A). The boomerang-shaped fragment geometry that is common with lunate facet fractures is not amenable to monoblock fixation using standard volar locking plates. The patient presented here had a boomerang-shaped fragment as part of the volar Barton fracture that was treated with a volar locking plate in isolation, and the volar lunate facet fragment displaced with loss of fixation and volar carpal subluxation. When noted as part of a complex distal radius fracture pattern, careful positioning of a monoblock volar plate on the J Hand Surg Am.
ulnar-most aspect of the distal radius can allow for at least 2 points of fixation into the lunate facet fragment, particularly if variable angle screws are used. Volar plate fixation can also be augmented by adding a single cannulated screw with a washer to secure the lunate facet fragment (Fig. 6B). Fragment-specific fixation implants,7 low-profile plates, and wire loop fixation8 are other potential fixation options. Some lunate facet fractures are avulsion-type fractures that occur as a component of a radiocarpal fracture-dislocation. These fragments tend to be small. Fixation is usually achieved with wire loop techniques, suture anchors, or mini-fragment screws, although screw fixation can be challenging and fraught with risk of fragmentation. When patients present with loss of fixation of the volar lunate facet fragment, as was the case for r
Vol. -, - 2014
4
VOLAR LUNATE FACET FRACTURES
FIGURE 4: A Plain radiographs and B clinical pictures demonstrating improved radiographic alignment and clinical range of motion after revision open reduction internal fixation of the lunate facet fragment.
J Hand Surg Am.
r
Vol. -, - 2014
VOLAR LUNATE FACET FRACTURES
5
FIGURE 5: A The teardrop is outlined with the dotted line and B the teardrop angle is drawn.
our patient, they typically have volar subluxation of the carpus and loss of supination. During revision open reduction internal fixation, the preferred interval for access to the fragment is between the flexor tendons and the ulnar neurovascular bundle.3 The volar lunate facet fragment can usually be mobilized by starting at the most proximal ulnar cortical edge, where the former fracture site is often visible even several weeks after injury. This is a critical detail to remember because the anatomy is substantially altered and can be confusing. This corner can be used to redevelop the boomerangshaped fracture fragment. The 10 inclined lateral radiograph is helpful to assess adequate reduction intraoperatively.3 Once reduced, fixation using plates or 1 of the techniques mentioned above can improve motion and function.1,3 Given the distal extension of the volar lunate facet fragment, any fixation applied to this fragment will appear to be intra-articular on the posteroanterior radiograph but should not be a cause for concern as long as the lateral radiograph confirms appropriate hardware placement. When distal plate placement is planned, we recommend performing J Hand Surg Am.
a carpal tunnel release and monitoring for postoperative signs of flexor tendon irritation necessitating removal of hardware.9 Corrective osteotomy also achieves good results for patients who present too late for revision open reduction internal fixation. In a series of 13 patients treated with intra-articular osteotomies for isolated malunions of the volar lunate facet, Ruch et al3 demonstrated substantial improvements in range of motion, grip strength, and Disabilities of the Arm, Shoulder, and Hand questionnaire scores. PREVENTION To prevent the complication of volar carpal subluxation, we recommend (1) preoperative and intraoperative clinical and radiographic vigilance to visualize the volar lunate facet fragment and (2) adequate fixation of the volar lunate facet fragment. Because of the irregular anatomy of this fragment, adequate fixation is difficult to achieve using monoblock fixation with a volar plate. Special attention to plate placement and the use of alternative techniques r
Vol. -, - 2014
6
VOLAR LUNATE FACET FRACTURES
FIGURE 6: A Lunate facet fragment reduced and secured with a cannulated screw and washer. B Final fixation construct with volar locking plate and cannulated screw and washer.
to augment fixation of the volar ulnar corner can prevent loss of fixation and the sequelae of malunions. Primary fixation of nascent malunions or corrective osteotomy has been shown to improve motion and function in these circumstances. J Hand Surg Am.
REFERENCES 1. Harness NG, Jupiter JB, Orbay JL, Raskin KB, Fernandez DL. Loss of fixation of the volar lunate facet fragment in fractures of the distal part of the radius. J Bone Joint Surg Am. 2004;86(9): 1900e1908.
r
Vol. -, - 2014
VOLAR LUNATE FACET FRACTURES
6. Harness NG, Ring D, Zurakowski D, Harris GJ, Jupiter JB. The influence of three-dimensional computed tomography reconstructions on the characterization and treatment of distal radial fractures. J Bone Joint Surg Am. 2006;88(6):1315e1323. 7. Saw N, Roberts C, Cutbush K, Hodder M, Couzens G, Ross M. Early experience with the TriMed fragment-specific fracture fixation system in intraarticular distal radius fractures. J Hand Surg Eur Vol. 2008;33(1):53e58. 8. Chin KR, Jupiter JB. Wire-loop fixation of volar displaced osteochondral fractures of the distal radius. J Hand Surg Am. 1999;24(3):525e533. 9. Kitay A, Swanstrom M, Schreiber JJ, et al. Volar plate position and flexor tendon rupture following distal radius fracture fixation. J Hand Surg Am. 2013;38(6):1091e1096.
2. Andermahr J, Lozano-Calderon S, Trafton T, Crisco JJ, Ring D. The volar extension of the lunate facet of the distal radius: a quantitative anatomic study. J Hand Surg Am. 2006;31(6):892e895. 3. Ruch DS, Wray WH III, Papadonikolakis A, Richard MJ, Leversedge FJ, Goldner RD. Corrective osteotomy for isolated malunion of the palmar lunate facet in distal radius fractures. J Hand Surg Am. 2010;35(11):1779e1786. 4. Medoff RJ. Essential radiographic evaluation for distal radius fractures. Hand Clin. 2005;21(3):279e288. 5. Fujitani R, Omokawa S, Iida A, Santo S, Tanaka Y. Reliability and clinical importance of teardrop angle measurement in intra-articular distal radius fracture. J Hand Surg Am. 2012;37(3): 454e459.
J Hand Surg Am.
7
r
Vol. -, - 2014
