carpal instability is broad category consisting of various patterns of injury , with dissociative type more common . a 13 -year -old boy presented at 6 months following a fall with restriction of wrist movements . patient had sustained a closed distal one -third both bones fracture forearm fixed with k -wire , and volar lunate instability was found during sequential follow -up . posttraumatic carpal instability should be identified at the earliest to avoid poor hand function and morbidity associated with it . carpal instability and its biomechanics have always been evolving due to the advancement in the field of radiology and arthroscopy . lunate plays a pivotal role and acts like an intercalated segment in carpal stability , loss of anchorage of this key structure cause intercalated segment instability . volar intercalated segment instability ( visi ) is a less common manifestation of dissociative carpal instability . a 13-year - boy had sustained distal one - third radius and ulna fracture after fall on an outstretched hand . open reduction and k - wire fixation was performed for both bone fracture forearm ( fig . 2 ) . he noticed restriction of dorsiflexion of wrist , while other movements normal . serial x - rays showed a loss of normal alignment of radio - lunate in comparison with the opposite ( fig . 3 , 4 ) . serial radiographs during follow - up showed a volar facing lunate with alteration of scapholunate and lunatocapitate angle and was diagnosed with a volar intercalated lunate instability ( fig . the patient was put on strict rehabilitation protocol and the dorsiflexion improved from 0 - 10 to 0 - 40. at 1 year follow - up patient is still having restriction of dorsiflexion ( fig . ( a ) post - operative radiograph of right wrist posterior - anterior and ( b ) lateral view showing reduced distal one - third radius and ulna fracture with implants in situ . ( a ) radiograph of wrist posterior - anterior and ( b ) lateral view at 2 months with uniting distal one - third radius and ulna fracture . ( a ) radiograph of both wrist posterior - anterior view left and ( b ) right showing union of distal one - third of radius and ulna . loss of gilula arc with flexed scaphoid suggesting carpal instability at 6-month follow - up . ( a ) radiograph of both wrists lateral view left and ( b ) right at 6 month follow - up showing volar facing lunate with loss of carpal alignment . ( a ) radiograh of right wrist at 1 year follow - up , post - anterior view and ( b and c ) lateral views , ( a ) showing healed distal one - third radius and ulna fracture , signet ring sign of scaphoid and moon like appearance of lunate . ( b ) volar facing lunate with loss of alignment between radius , lunate and capitate . ( c ) reduction in the scapholunate angle ( 16 ) and increased capitolunate angle ( 40 ) . ( a ) clinical photograph at 1 year follow - up showing reduction of dorsiflexion ( 0 - 40 ) and ( b ) normal palmar flexion ( 0 - 80 ) of wrist . carpal instability should be considered as a differential in patients presenting with chronic wrist pain and restricted movements following trauma . classified carpal instability into four categories and lunato - triquetral ligament is involved in stage three which leads to volar lunate instability . visi is a condition in which there is pathologic volar flexion of the lunate , with or without a similar posture of the other proximal row carpal bones . posttraumatic volar lunate instability is an entity that can be missed during the initial traumatic event because of its subtle nature . posttraumatic carpal stability diagnosed at the earliest avoids advanced surgical procedures such as reconstruction and fusion of joint . lunate instability in plain radiograph can be diagnosed with the alteration of various angles namely the loss of scapholunate angle , loss of alignment between the lunate , capitate and radius and increase in the capitolunate angle . treatment options include from closed reduction and k - wire fixation , dorsal capsulodesis , tenodesis , arthroscopic or open repair with reconstruction and finally arthrodesis . this injury could be subtle in nature before reduction and fixation that led to delay in diagnosis or iatrogenic in nature after reduction of the fracture . wrist function is a complex interaction of various biomechanics involving the carpal bones , ligaments , and the distal radio - ulnar complex . awareness of carpal instability associated with fractures or injuries around the wrist is needed by the treating surgeon to avoid delay in diagnosis and treatment . to suspect visi following a wrist injury and also following reduction with k - wire fixation . follow - up of patient at regular intervals to prevent morbidity due to this deformity .
introduction : carpal instability is broad category consisting of various patterns of injury , with dissociative type more common.case report : a 13 -year -old boy presented at 6 months following a fall with restriction of wrist movements . patient had sustained a closed distal one -third both bones fracture forearm fixed with k -wire , and volar lunate instability was found during sequential follow -up.conclusion : posttraumatic carpal instability should be identified at the earliest to avoid poor hand function and morbidity associated with it .