“Locked” Scapholunate Instability Diagnosed with 4D Computed Tomography Scan
05 November 2018
24 September 2018
10 January 2019 (eFirst)
Background Scapholunate instability (SLI) has a wide range of clinical and radiological presentations. The management depends on the stage of the disorder. Subluxation of scaphoid is pathognomonic feature of the SLI. We describe a patient with SLI with a dislocated proximal pole of scaphoid, out of the distal radius scaphoid fossa. The 4D (three-dimensions + time) computed tomography (CT) scan demonstrated that the scaphoid did not reduce throughout wrist motion.
Case Description A 20-year-old male presented with SLI following a fall skateboarding. The 4D CT scan revealed the dislocated scaphoid that did not reduce with wrist motion. He underwent open reduction of the proximal pole of scaphoid and SL reconstruction using flexor carpi radialis (FCR) tendon graft with the Quad tenodesis technique. At 1 year, he had improved pain, wrist functions, and maintained satisfactory radiological alignment.
Literature Review We are not aware of any previous description of the dorsal scaphoid dislocation in association with scapolunate instability.
Clinical Relevance We recommend that the SLI staging classification needs to be expanded to include dislocation (locked) stage. The 4D CT has a significant role in identifying the instability and its reducibility.
Level of Evidence This is a level V study.
Keywordsscapholunate instability - locked scapholunate instability - scaphoid dislocation - carpal - instability - 4D CT scan
This study was done at Department of Orthopedic Surgery, Flinders University and Flinders Medical Center, Bedford Park, Adelaide, South Australia, Australia.
- 1 Watson HK, Weinzweig J, Zeppieri J. The natural progression of scaphoid instability. Hand Clin 1997; 13 (01) 39-49
- 2 Watson HK, Ashmead IV D, Makhlouf MV. Examination of the scaphoid. J Hand Surg Am 1988; 13 (05) 657-660
- 3 LaStayo P, Howell J. Clinical provocative tests used in evaluating wrist pain: a descriptive study. J Hand Ther 1995; 8 (01) 10-17
- 4 Zhao K, Breighner R, Holmes III D, Leng S, McCollough C, An K-N. A technique for quantifying wrist motion using four-dimensional computed tomography: approach and validation. J Biomech Eng 2015; 137 (07) 0745011-0745015
- 5 Garcia-Elias M, Alomar Serrallach X, Monill Serra J. Dart-throwing motion in patients with scapholunate instability: a dynamic four-dimensional computed tomography study. J Hand Surg Eur Vol 2014; 39 (04) 346-352
- 6 Berger RA, Bishop AT, Bettinger PC. New dorsal capsulotomy for the surgical exposure of the wrist. Ann Plast Surg 1995; 35 (01) 54-59
- 7 Bain GI, Watts AC, McLean J, Lee YC, Eng K. Cable-augmented, quad ligament tenodesis scapholunate reconstruction: rationale, surgical technique, and preliminary results. Tech Hand Up Extrem Surg 2013; 17 (01) 13-19
- 8 Bain GI, Watts AC, McLean J, Lee YC, Eng K. Cable-augmented, quad ligament tenodesis scapholunate reconstruction. J Wrist Surg 2015; 4 (04) 246-251
- 9 Kwon YW, Kulwicki KJ, Zuckerman JD. Glenohumeral joint subluxation, dislocations and instability. In: Rockwood and Green’s Fractures in Adults: Two Volumes Plus Integrated Content Website (Rockwood, Green, and Wilkins’ Fractures). Vol 1. Seventh. Lippincott Williams & Wilkins; 2012: 1179
- 10 Short WH, Werner FW, Green JK, Masaoka S. Biomechanical evaluation of ligamentous stabilizers of the scaphoid and lunate. J Hand Surg 2002; 27 (06) 991-1002
- 11 Haerle M, Garcia-Elias M, Wahegaonkar A, Bain GI, Luchetti R. IFSSH Scientific Committe on Carpal Instability. Part 2: Management of Scapho-Lunate Dissociation; 2016: 5-6. Avaialable at: http://www.ifssh.info/pdf/Carpal_Instability_Part_2_2016_FINAL_Formatted_for_website_and_book.pdf
- 12 Horton T, Shin AY, Cooney WP. Isolated scaphoid dislocation associated with axial carpal dissociation: an unusual injury report. J Hand Surg 2004; 29 (06) 1102-1108
- 13 Leung YF, Wai YL, Kam WL, Ip PS. Solitary dislocation of the scaphoid: From case report to literature review. J Hand Surg Br Eur Vol 1998; 23 (01) 88-92
- 14 Bain GI, McGuire DT. Decision Making for Partial Carpal Fusions. J Wrist Surg 2012; 1 (02) 103-114
- 15 Halpenny D, Courtney K, Torreggiani WC. Dynamic four-dimensional 320 section CT and carpal bone injury-a description of a novel technique to diagnose scapholunate instability. Clin Radiol 2012; 67 (02) 185-187