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Palmar dislocation of the trans-scaphoid-lunate unit
P A L M A R D I S L O C A T I O N OF T H E T R A N S - S C A P H O I D - L U N A T E UNIT L. EKEROT
From the Department of Hand Surgery, Lund University, Malm6 University Hospital, Malm6, Sweden A rare case of total palmar trans-scaphoid-lunate dislocation is reported. Open reduction, bone grafting and internal fixation were followed by uneventful healing. At follow-up 70 months after injury there is no osteonecrosis and the wrist function is almost normal.
Journal of Hand Surgery (British and European Volume, 19959 20B: 4:557-560 follow-up the patient has no complaints and good wrist function.
Total palmar trans-scaphoid:lunate dislocation as a unit is reportedly rare. It implies a fracture through the scaphoid, extensive ligamentous damage and a total deprivation of circulation to the proximal pole of the scaphoid and the lunate. A poor prognosis might be expected. A case is reported with a good result after immediate open reduction and internal fixation. At late
Fig 1
CASE REPORT
A 19-year-old woman fell about 16 mea~oe~and sustained bilateral wrist injuries and a lumbar vertebral compression fracture without nerve complications. On the
(a and b) Initial radiographs show the palmar-proximal dislocation of the bone unit. (c) The corresponding deformity of the volar aspect of the forearm. 557
558
THEJOURNALOF HANDSURGERYVOL.20BNo. 4 AUGUST1995
Fig 1 Pleasesee p. 557 for legend. right side she had a closed distal fracture of the radius and on the left side a closed trans-scaphoid-lunate dislocation. The proximal pole of the scaphoid and the lunate showed palmar and proximal displacement to a position 10 cm proximal to the radio-carpal joint. The volar aspect of the distal forearm was swollen with the dislocated bone unit palpable (Fig 1). At operation there was blood in the carpal tunnel and a transverse rent in the volar carpal joint capsule. The proximal pole of the scaphoid and the lunate, united by the intact scapho-lunate ligament but completely denuded o f soft
Fig 2
tissue attachments, were found submuscularly in the forearm (Fig 2). The bone unit was replaced via palmar and dorsal approaches, the fracture was fixed with an Ender's plate and grafted with a cancellous bone peg from the iliac crest fashioned to bridge the exactly reduced scaphoid fragments. There was no comminution of the fracture. The scaphoid, capitate and lunate bones were transfixed with K-wires, and the palmar ligaments and capsule repaired. Post-operatively an above-elbow cast was used for 3 months, then a low circular cast for additional 2 months. The Ender's plate was removed 2 weeks after mobilization. At this operation the scaphoid fracture was found to have healed. The patient returned to her native country, and contact was lost for some time. At follow-up 22 months after injury she was free of pain, with slight restriction in wrist extension and flexion compared to the right wrist, the radial fracture having been treated conservatively, and she had no reduction in grip strength. Radiographs showed healing of the scaphoid and some increase in radio-density of the lunate. M R I without contrast medium showed a low signal on Tl-weighted images and a high signal on T2-weighted images in the centre of the lunate, but the findings were not conclusive for osteonecrosis. 70 months after injury she is still free
An operative photograph shows the dislocated bones with an intact interosseous ligament. The unit was totally denuded of soft tissue attachments.
TRANS-SCAPHOID-LUNATEDISLOCATION of pain and working as a housewife. The range of motion of the wrist is 60 ° of extension, 70 ° of flexion (right wrist 80/80), 30 ° of radial abduction and 40 ° of ulnar abduction. Grip strength (Jamar dynamometer) on the left is 28 kg and on the right 32 kg. Radiographs including tomography show no signs of osteonecrosis and no arthrotic changes within the radio-carpal and carpal joints. The unusual shape of the radial contour of the scaphoid is found also on the right side (Figs 3 and 4).
Fig 3
559 DISCUSSION Dislocation within the scapho-lunate complex implies rupture of its ligamentous attachments or a fracture of the scaphoid. Detachment between the scaphoid and the capitate might dislocate the scaphoid and the lunate as a unit (Taleisnik et al, 1982; Sarrafian and Breihan, 1990). When there is a scaphoid fracture, the result might be a palmar trans-scaphoid-lunate dislocation. This lesion has rarely been reported. Green and O'Brien
(a) Anteroposterior radiograph 70 months after injury. The scaphoid is healed and there is no evidenceof scaphoid or lunate necrosis. There is some ulnar translocation of the carpus. (b) Side view. (c) Anteroposteriorradiograph of the right wrist for comparison.
560
THE JOURNAL OF HAND SURGERY VOL. 20B No. 4 AUGUST 1995
Fig 4
Fig 3
Please see p. 559 for legend.
(1978) described two probable cases, and two cases are formally reported by Stern (1984). The mechanism of injury is unknown but the extensive damage probably indicates high energy trauma. Thus, it might be interpreted as the end-stage of dorsal trans-scaphoid peri-lunate carpal dislocation by analogy with the peri-lunate/lunate carpal dislocation. Total deprivation of the proximal pole of the scaphoid and the lunate of their circulation might result in non-union of the scaphoid and avascular necrosis, and the ligament injuries might cause wrist instability and a collapse pattern. Apparently few of these complications occur. In this case immediate open reduction, bone grafting and internal fixation were followed by uneventful healing. A cancellous bone graft was chosen to secure as intimate contact as possible between clearly vascularized bone and the proximal pole of the scaphoid. The lunate developed a slight increase in radio-density but no avascular necrosis (White and Omer, 1984), and restoration of circulation, probably via the grafted scaphoid fracture and the intact scapho-lunate interosseous ligament, was not followed by deformation and
T o m o g r a p h s s h o w i n g absence o f t e x t u r a l or structural b o n e changes i n d i c a t i n g osteonecrosis. A tear f r a g m e n t between the s c a p h o i d a n d the l u n a t e is noted.
collapse (Aspenberg et al, 1994). The long-term possibility of degenerative disease exists, and is already indicated by some irregularities at the lunate capitate joint (Fig 3a). It is interesting that a completely avascular lunate showed recovery without developing avascular necrosis. References ASPENBERG, P., WANG, J. S., JONSSON, K. and HAGERT, C. G. (1994). Experimental osteoneerosis of the lunate. Journal of Hand Surgery, 19B: 5: 565-569. GREEN, D. P. and O'BRIEN, E. T. (1978). Open reduction of carpal dislocations: Indications and operative techniques. Journal of Hand Surgery, 3: 250-265. SARRAFIAN, S. K. and BREIHAN, J. H. (1990 ). Palmar dislocation of scaphoid and lunate as a unit. Journal of Hand Surgery, 15A: 134-139. STERN, P. J. (1984). Transscaphoid-lunate dislocation: A report of two cases. Journal of Hand Surgery, 9A: 370 373. TALEISNIK, J., MALERICH, M. and PRIETTO, M. (1982). Palmar carpal instability secondary to dislocation of scaphoid and lunate: Report of case and review of the literature. Journal of Hand Surgery, 7A: 606-612. WHITE, R. E. and OMER, G. E. (1984). Transient vascular compromise of the lunate after fracture-dislocation or dislocation of the carpus. Journal of Hand Surgery, 9A: 181-184.
Accepted: 20 February 1995 Dr Lars Ekerot MD, University of Lund, Department of Hand Surgery, Malta6 Allm/~nna Sjukhus, 5-21401 Maim6, Sweden. © 1995 The British Societyfor Surgery of the Hand
From the Department of Hand Surgery, Lund University, Malm6 University Hospital, Malm6, Sweden A rare case of total palmar trans-scaphoid-lunate dislocation is reported. Open reduction, bone grafting and internal fixation were followed by uneventful healing. At follow-up 70 months after injury there is no osteonecrosis and the wrist function is almost normal.
Journal of Hand Surgery (British and European Volume, 19959 20B: 4:557-560 follow-up the patient has no complaints and good wrist function.
Total palmar trans-scaphoid:lunate dislocation as a unit is reportedly rare. It implies a fracture through the scaphoid, extensive ligamentous damage and a total deprivation of circulation to the proximal pole of the scaphoid and the lunate. A poor prognosis might be expected. A case is reported with a good result after immediate open reduction and internal fixation. At late
Fig 1
CASE REPORT
A 19-year-old woman fell about 16 mea~oe~and sustained bilateral wrist injuries and a lumbar vertebral compression fracture without nerve complications. On the
(a and b) Initial radiographs show the palmar-proximal dislocation of the bone unit. (c) The corresponding deformity of the volar aspect of the forearm. 557
558
THEJOURNALOF HANDSURGERYVOL.20BNo. 4 AUGUST1995
Fig 1 Pleasesee p. 557 for legend. right side she had a closed distal fracture of the radius and on the left side a closed trans-scaphoid-lunate dislocation. The proximal pole of the scaphoid and the lunate showed palmar and proximal displacement to a position 10 cm proximal to the radio-carpal joint. The volar aspect of the distal forearm was swollen with the dislocated bone unit palpable (Fig 1). At operation there was blood in the carpal tunnel and a transverse rent in the volar carpal joint capsule. The proximal pole of the scaphoid and the lunate, united by the intact scapho-lunate ligament but completely denuded o f soft
Fig 2
tissue attachments, were found submuscularly in the forearm (Fig 2). The bone unit was replaced via palmar and dorsal approaches, the fracture was fixed with an Ender's plate and grafted with a cancellous bone peg from the iliac crest fashioned to bridge the exactly reduced scaphoid fragments. There was no comminution of the fracture. The scaphoid, capitate and lunate bones were transfixed with K-wires, and the palmar ligaments and capsule repaired. Post-operatively an above-elbow cast was used for 3 months, then a low circular cast for additional 2 months. The Ender's plate was removed 2 weeks after mobilization. At this operation the scaphoid fracture was found to have healed. The patient returned to her native country, and contact was lost for some time. At follow-up 22 months after injury she was free of pain, with slight restriction in wrist extension and flexion compared to the right wrist, the radial fracture having been treated conservatively, and she had no reduction in grip strength. Radiographs showed healing of the scaphoid and some increase in radio-density of the lunate. M R I without contrast medium showed a low signal on Tl-weighted images and a high signal on T2-weighted images in the centre of the lunate, but the findings were not conclusive for osteonecrosis. 70 months after injury she is still free
An operative photograph shows the dislocated bones with an intact interosseous ligament. The unit was totally denuded of soft tissue attachments.
TRANS-SCAPHOID-LUNATEDISLOCATION of pain and working as a housewife. The range of motion of the wrist is 60 ° of extension, 70 ° of flexion (right wrist 80/80), 30 ° of radial abduction and 40 ° of ulnar abduction. Grip strength (Jamar dynamometer) on the left is 28 kg and on the right 32 kg. Radiographs including tomography show no signs of osteonecrosis and no arthrotic changes within the radio-carpal and carpal joints. The unusual shape of the radial contour of the scaphoid is found also on the right side (Figs 3 and 4).
Fig 3
559 DISCUSSION Dislocation within the scapho-lunate complex implies rupture of its ligamentous attachments or a fracture of the scaphoid. Detachment between the scaphoid and the capitate might dislocate the scaphoid and the lunate as a unit (Taleisnik et al, 1982; Sarrafian and Breihan, 1990). When there is a scaphoid fracture, the result might be a palmar trans-scaphoid-lunate dislocation. This lesion has rarely been reported. Green and O'Brien
(a) Anteroposterior radiograph 70 months after injury. The scaphoid is healed and there is no evidenceof scaphoid or lunate necrosis. There is some ulnar translocation of the carpus. (b) Side view. (c) Anteroposteriorradiograph of the right wrist for comparison.
560
THE JOURNAL OF HAND SURGERY VOL. 20B No. 4 AUGUST 1995
Fig 4
Fig 3
Please see p. 559 for legend.
(1978) described two probable cases, and two cases are formally reported by Stern (1984). The mechanism of injury is unknown but the extensive damage probably indicates high energy trauma. Thus, it might be interpreted as the end-stage of dorsal trans-scaphoid peri-lunate carpal dislocation by analogy with the peri-lunate/lunate carpal dislocation. Total deprivation of the proximal pole of the scaphoid and the lunate of their circulation might result in non-union of the scaphoid and avascular necrosis, and the ligament injuries might cause wrist instability and a collapse pattern. Apparently few of these complications occur. In this case immediate open reduction, bone grafting and internal fixation were followed by uneventful healing. A cancellous bone graft was chosen to secure as intimate contact as possible between clearly vascularized bone and the proximal pole of the scaphoid. The lunate developed a slight increase in radio-density but no avascular necrosis (White and Omer, 1984), and restoration of circulation, probably via the grafted scaphoid fracture and the intact scapho-lunate interosseous ligament, was not followed by deformation and
T o m o g r a p h s s h o w i n g absence o f t e x t u r a l or structural b o n e changes i n d i c a t i n g osteonecrosis. A tear f r a g m e n t between the s c a p h o i d a n d the l u n a t e is noted.
collapse (Aspenberg et al, 1994). The long-term possibility of degenerative disease exists, and is already indicated by some irregularities at the lunate capitate joint (Fig 3a). It is interesting that a completely avascular lunate showed recovery without developing avascular necrosis. References ASPENBERG, P., WANG, J. S., JONSSON, K. and HAGERT, C. G. (1994). Experimental osteoneerosis of the lunate. Journal of Hand Surgery, 19B: 5: 565-569. GREEN, D. P. and O'BRIEN, E. T. (1978). Open reduction of carpal dislocations: Indications and operative techniques. Journal of Hand Surgery, 3: 250-265. SARRAFIAN, S. K. and BREIHAN, J. H. (1990 ). Palmar dislocation of scaphoid and lunate as a unit. Journal of Hand Surgery, 15A: 134-139. STERN, P. J. (1984). Transscaphoid-lunate dislocation: A report of two cases. Journal of Hand Surgery, 9A: 370 373. TALEISNIK, J., MALERICH, M. and PRIETTO, M. (1982). Palmar carpal instability secondary to dislocation of scaphoid and lunate: Report of case and review of the literature. Journal of Hand Surgery, 7A: 606-612. WHITE, R. E. and OMER, G. E. (1984). Transient vascular compromise of the lunate after fracture-dislocation or dislocation of the carpus. Journal of Hand Surgery, 9A: 181-184.
Accepted: 20 February 1995 Dr Lars Ekerot MD, University of Lund, Department of Hand Surgery, Malta6 Allm/~nna Sjukhus, 5-21401 Maim6, Sweden. © 1995 The British Societyfor Surgery of the Hand