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The Journal of Hand Surgery (Eur) 40(5)
Conflict of interests None declared.
Ethical approval details The patient was informed that the case would be submitted for publication and gave his consent.
References Akahane M, Ono H, Sada M, Saitoh M. Bilateral bipartite lunate: a case report. J Hand Surg Am. 2002, 27: 355–9. Drez D Jr, Romero JR 3rd. Congenital bipartite carpal lunate. A case report. Am J Sports Med. 1978, 6: 405–8. Loh BW, Harvey J, Ek ET. Congenital bipartite lunate presenting as a misdiagnosed lunate fracture: a case report. J Med Case Rep. 2011, 14: 102.
C. H. Lee and K. H. Lee Department of Orthopaedic Surgery, Kepco Medical Center, and Hanyang University College of Medicine, Seoul, Korea. Corresponding author: [email protected]
© The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav doi: 10.1177/1753193413508513 available online at http://jhs.sagepub.com
Changes in the area of the volar scapholunate interosseous ligament at different positions of the wrist Dear Sir, Partial or complete tears of the scapholunate interosseous ligament (SLIL) are frequently observed after wrist injury and may lead to wrist pain and kinematic changes in the carpus. A fall onto an outstretched hand in hyperextension is the predominant mechanism for SLIL injuries (Mayfield, 1980). In addition, rotation of the forearm may be another important causative factor of SLIL injuries. Recent investigation suggests that the volar part of the SLIL is thinner and more elastic than the dorsal part of the SLIL (Berger et al., 1999). Therefore, we investigated changes in the area of the volar SLIL during wrist full extension and forearm rotation in vivo. Twelve healthy adult volunteers were recruited for this study, and their right wrists were studied. The volunteers were divided into two groups of six: in one group, computer tomography (CT) images were acquired at wrist full extension, and in the other group, CT images were obtained at forearm extreme
pronation or supination. In the wrists of both groups, the neutral position was included as the control baseline wrist position. We used data from the CT scans to reconstruct 3-dimensional images using analytic software (Mimics 10.0; Materalise, Leuven, Belgium). We defined the volar region of the SLIL according to their known bone insertions and marked the origin and insertion on the surfaces of the bone reconstructions (Nagao et al., 2005) (Figure 1). We then measured the area of volar SLIL using analytic software (ImageJ 1.42; National Institutes of Health, Maryland, USA). We analyzed the changes in area using repeated-measure one-way analysis of variance followed by post-hoc paired t-tests. From the neutral position to full extension, areas (X ± SD) of the volar SLIL increased from 30.6 ± 3.0 to 39.8 ± 4.5 mm2, and the change was statistically significant (p = 0.001). Areas of the volar SLIL increased from 31.1 ± 3.5 to 33.9 ± 4.9 mm2, when the wrist moved from the neutral position to forearm extreme pronation, and the increase was also statistically significantly (p = 0.007). No significant difference in the average areas of the volar SLIL were found at forearm extreme supination (31.7 ± 3.6 mm2) compared with those in neutral position (31.1 ± 3.5 mm2) (p = 0.131). Using in vivo noninvasive 3-dimensional bone reconstruction to study joint motion has become increasingly popular. Many carpal injuries occur when the hands are outstretched to support body weight, and wrists are usually at positions of full extension. The study by Lee et al. (2010) indicated a mean elongation in loaded extension of 48.4% for the palmar component of the SLIL using in vivo magnetic resonance image scanning and image reconstruction. Our data showed that mean percentage increases of the extending areas of the volar SLIL in full extension and forearm extreme pronation were 30.1% and 9%, respectively. Our findings suggest that the volar part of the SLIL was highly strained in two positions. Furthermore, our findings suggest that wrist full extension may have a more important influence on the areas of volar SLIL than forearm rotation. However, based on our findings, we are unable to speculate whether the volar region of SLIL is more easily disrupted or injured earlier after hand trauma, because less extendable ligaments do not necessarily disrupt more easily. Ultimately, the damage incurred depends on the strengths of different regions of the SLIL, loading speed, and structural properties, such as the elastic modulus of these regions. We acknowledge the limitations of our study. One limitation was the small sample size, creating the potential for type II (false negative) errors for detecting changes in the extending area at the forearm
Downloaded from jhs.sagepub.com at Univ. of Tasmania Library on September 27, 2015
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Short report letters
Figure 1. Volar scapholunate ligament (light yellow) studied in three positions. A: neutral; B: full extension; C: forearm extreme pronation. All images are anteroposterior view.
supination. In addition, we modelled the origin and insertion of the ligaments based on anatomic information, without considering individual differences of the volunteers. The SLIL ligament is short and often difficult to investigate. Measurement of the extending area may be a more reasonable way to quantify changes of the short ligaments, and the findings may perhaps better reflect the tensional status of short ligaments. Conflict of interests The authors declare that there are no conflict of interests.
References Berger RA, Imeada T, Berglund L, An KN. Constraint and material properties of the subregions of the scapholunate interosseous ligament. J Hand Surg Am. 1999, 24: 953–62. Lee SK, Park J, Baskies M, Forman R, Yildirim G, Walker P. Differential strain of the axially loaded scapholunate interosseous ligament. J Hand Surg Am. 2010, 35: 245–51. Mayfield JK. Mechanism of carpal injuries. Clin Orthop Relat Res. 1980, 149: 45–54. Nagao S, Patterson RM, Buford WL Jr, Andersen CR, Shah MA, Viegas SF. Three-dimensional description of ligamentous attachments around the lunate. J Hand Surg Am. 2005, 30: 685–92.
J. Chen, J. Tan and J. B. Tang Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, Nantong and Jiangsu Hand Surgery Center, Jiangsu, China. Corresponding author: [email protected] © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav doi: 10.1177/1753193413513985 available online at http://jhs.sagepub.com
Entrapment of the extensor indicis proprius tendon in the callus after a distal radial fracture Dear Sir, A 17-year-old boy sustained a closed volarly displaced distal radial fracture during gymnastic exercises. A closed reduction was performed and post-manipulation radiographs were satisfactory. A below-elbow plaster cast was applied for 5 weeks. The cast was a little too long distally, reducing flexion of the fingers in the metacarpophalangeal (MP) joints. After removal of the cast, the patient noticed restriction of flexion of the index finger in the MP joint. The problem occurred when the wrist was in flexion, whereas in wrist extension full finger flexion was possible (Figure 1 a,b). Extension of the index finger was normal as well as mobility of the other fingers. A one-month course of rehabilitation failed to resolve the problem. Ultrasound examination suggested rupture of one of the index finger extensors with secondary adhesion of the stump to the extensor retinaculum, thus limiting the finger flexion. Surgical exploration was done through the fourth compartment revealing a complete rupture of the extensor indicis proprius (EIP) tendon with the distal stump being entrapped in the bony callus at the site of the fracture (Figure 2). Extensor digitorum communis (EC) to the index finger was intact. The distal end of the EIP tendon was detached from the callus and sutured to the intact EC tendon, because direct repair was not feasible. The bony callus was trimmed down. A splint was applied for 4 weeks with the wrist in slight extension, followed by physiotherapy. Two months after the operation the patient’s index finger movement was full. Spontaneous extensor tendon rupture after conservatively treated distal radial fracture is
Downloaded from jhs.sagepub.com at Univ. of Tasmania Library on September 27, 2015
The Journal of Hand Surgery (Eur) 40(5)
Conflict of interests None declared.
Ethical approval details The patient was informed that the case would be submitted for publication and gave his consent.
References Akahane M, Ono H, Sada M, Saitoh M. Bilateral bipartite lunate: a case report. J Hand Surg Am. 2002, 27: 355–9. Drez D Jr, Romero JR 3rd. Congenital bipartite carpal lunate. A case report. Am J Sports Med. 1978, 6: 405–8. Loh BW, Harvey J, Ek ET. Congenital bipartite lunate presenting as a misdiagnosed lunate fracture: a case report. J Med Case Rep. 2011, 14: 102.
C. H. Lee and K. H. Lee Department of Orthopaedic Surgery, Kepco Medical Center, and Hanyang University College of Medicine, Seoul, Korea. Corresponding author: [email protected]
© The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav doi: 10.1177/1753193413508513 available online at http://jhs.sagepub.com
Changes in the area of the volar scapholunate interosseous ligament at different positions of the wrist Dear Sir, Partial or complete tears of the scapholunate interosseous ligament (SLIL) are frequently observed after wrist injury and may lead to wrist pain and kinematic changes in the carpus. A fall onto an outstretched hand in hyperextension is the predominant mechanism for SLIL injuries (Mayfield, 1980). In addition, rotation of the forearm may be another important causative factor of SLIL injuries. Recent investigation suggests that the volar part of the SLIL is thinner and more elastic than the dorsal part of the SLIL (Berger et al., 1999). Therefore, we investigated changes in the area of the volar SLIL during wrist full extension and forearm rotation in vivo. Twelve healthy adult volunteers were recruited for this study, and their right wrists were studied. The volunteers were divided into two groups of six: in one group, computer tomography (CT) images were acquired at wrist full extension, and in the other group, CT images were obtained at forearm extreme
pronation or supination. In the wrists of both groups, the neutral position was included as the control baseline wrist position. We used data from the CT scans to reconstruct 3-dimensional images using analytic software (Mimics 10.0; Materalise, Leuven, Belgium). We defined the volar region of the SLIL according to their known bone insertions and marked the origin and insertion on the surfaces of the bone reconstructions (Nagao et al., 2005) (Figure 1). We then measured the area of volar SLIL using analytic software (ImageJ 1.42; National Institutes of Health, Maryland, USA). We analyzed the changes in area using repeated-measure one-way analysis of variance followed by post-hoc paired t-tests. From the neutral position to full extension, areas (X ± SD) of the volar SLIL increased from 30.6 ± 3.0 to 39.8 ± 4.5 mm2, and the change was statistically significant (p = 0.001). Areas of the volar SLIL increased from 31.1 ± 3.5 to 33.9 ± 4.9 mm2, when the wrist moved from the neutral position to forearm extreme pronation, and the increase was also statistically significantly (p = 0.007). No significant difference in the average areas of the volar SLIL were found at forearm extreme supination (31.7 ± 3.6 mm2) compared with those in neutral position (31.1 ± 3.5 mm2) (p = 0.131). Using in vivo noninvasive 3-dimensional bone reconstruction to study joint motion has become increasingly popular. Many carpal injuries occur when the hands are outstretched to support body weight, and wrists are usually at positions of full extension. The study by Lee et al. (2010) indicated a mean elongation in loaded extension of 48.4% for the palmar component of the SLIL using in vivo magnetic resonance image scanning and image reconstruction. Our data showed that mean percentage increases of the extending areas of the volar SLIL in full extension and forearm extreme pronation were 30.1% and 9%, respectively. Our findings suggest that the volar part of the SLIL was highly strained in two positions. Furthermore, our findings suggest that wrist full extension may have a more important influence on the areas of volar SLIL than forearm rotation. However, based on our findings, we are unable to speculate whether the volar region of SLIL is more easily disrupted or injured earlier after hand trauma, because less extendable ligaments do not necessarily disrupt more easily. Ultimately, the damage incurred depends on the strengths of different regions of the SLIL, loading speed, and structural properties, such as the elastic modulus of these regions. We acknowledge the limitations of our study. One limitation was the small sample size, creating the potential for type II (false negative) errors for detecting changes in the extending area at the forearm
Downloaded from jhs.sagepub.com at Univ. of Tasmania Library on September 27, 2015
541
Short report letters
Figure 1. Volar scapholunate ligament (light yellow) studied in three positions. A: neutral; B: full extension; C: forearm extreme pronation. All images are anteroposterior view.
supination. In addition, we modelled the origin and insertion of the ligaments based on anatomic information, without considering individual differences of the volunteers. The SLIL ligament is short and often difficult to investigate. Measurement of the extending area may be a more reasonable way to quantify changes of the short ligaments, and the findings may perhaps better reflect the tensional status of short ligaments. Conflict of interests The authors declare that there are no conflict of interests.
References Berger RA, Imeada T, Berglund L, An KN. Constraint and material properties of the subregions of the scapholunate interosseous ligament. J Hand Surg Am. 1999, 24: 953–62. Lee SK, Park J, Baskies M, Forman R, Yildirim G, Walker P. Differential strain of the axially loaded scapholunate interosseous ligament. J Hand Surg Am. 2010, 35: 245–51. Mayfield JK. Mechanism of carpal injuries. Clin Orthop Relat Res. 1980, 149: 45–54. Nagao S, Patterson RM, Buford WL Jr, Andersen CR, Shah MA, Viegas SF. Three-dimensional description of ligamentous attachments around the lunate. J Hand Surg Am. 2005, 30: 685–92.
J. Chen, J. Tan and J. B. Tang Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, Nantong and Jiangsu Hand Surgery Center, Jiangsu, China. Corresponding author: [email protected] © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav doi: 10.1177/1753193413513985 available online at http://jhs.sagepub.com
Entrapment of the extensor indicis proprius tendon in the callus after a distal radial fracture Dear Sir, A 17-year-old boy sustained a closed volarly displaced distal radial fracture during gymnastic exercises. A closed reduction was performed and post-manipulation radiographs were satisfactory. A below-elbow plaster cast was applied for 5 weeks. The cast was a little too long distally, reducing flexion of the fingers in the metacarpophalangeal (MP) joints. After removal of the cast, the patient noticed restriction of flexion of the index finger in the MP joint. The problem occurred when the wrist was in flexion, whereas in wrist extension full finger flexion was possible (Figure 1 a,b). Extension of the index finger was normal as well as mobility of the other fingers. A one-month course of rehabilitation failed to resolve the problem. Ultrasound examination suggested rupture of one of the index finger extensors with secondary adhesion of the stump to the extensor retinaculum, thus limiting the finger flexion. Surgical exploration was done through the fourth compartment revealing a complete rupture of the extensor indicis proprius (EIP) tendon with the distal stump being entrapped in the bony callus at the site of the fracture (Figure 2). Extensor digitorum communis (EC) to the index finger was intact. The distal end of the EIP tendon was detached from the callus and sutured to the intact EC tendon, because direct repair was not feasible. The bony callus was trimmed down. A splint was applied for 4 weeks with the wrist in slight extension, followed by physiotherapy. Two months after the operation the patient’s index finger movement was full. Spontaneous extensor tendon rupture after conservatively treated distal radial fracture is
Downloaded from jhs.sagepub.com at Univ. of Tasmania Library on September 27, 2015
