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Isolated dorsal dislocation of the scaphoid
ISOLATED
DORSAL
DISLOCATION
OF THE
SCAPHOID
G. INOUEand N. MAEDA From the Division of Hand Surgery, Nagoya University School of Medicine, Japan
A case of isolated dorsal dislocation of the scaphoid is reported. The patient was treated surgically with a good result. Journal of Hand Surgery (British VoIume, 1990) 15B: 368-369 While primary or secondary rotational subluxation of the scaphoid is not uncommon, isolated dislocation of this bone is extremely rare. In our review of the available English literature, there were 12 case-reports describing isolated dislocation of the scaphoid : five cases of anterior dislocation (Higgs, 1930; Kuth, 1939; Murakami, 1977; Thomas, 1977) and seven of radial dislocation (Buzy, 1934; Walker, 1943; Russell, 1949; Schlossbach, 1954; Connell and Dyson, 1955; Maki et al., 1982; Amamilo et al., 1985). Isolated dorsal dislocation of the scaphoid has not been previously described. Case report
An 18-year-old right-handed industrial worker was admitted to hospital complaining of pain and loss of motion of the wrist. 14 days earlier, his left wrist had been caught in a press machine which forced it into dorsiflexion. Examination found moderate swelling and tenderness on the dorsal aspect of the wrist. The neurovascular state of the hand was intact, but wrist motion was limited to 0” of dorsiflexion and 40” of palmartlexion.
Fig. 1
Lateral x-ray films (Fig. la) showed the proximal pole of the scaphoid with a small fracture displaced dorsally, extended over the dorsal rim of the radius. The scaphoid was rotated 70” to the long axis of the radius. The lunate was dorsiflexed and there was minimal subluxation of the mid-carpal joint. The P.-A. film (Fig. lb) showed an increased scapholunate gap and a foreshortened appearance of the scaphoid. After unsuccessful attempts at closed reduction, open reduction was performed through a dorsal approach. After the skin had been incised and the extensor tendons retracted, a bony prominence was evident beneath the dorsal wrist capsule which was still intact. When this capsule was incised, the proximal pole of the scaphoid was seen to be dislocated dorsally. The interosseous scapho-lunate ligament was avulsed from the dorsal aspect of the lunate with a chip fragment. The scaphoid was reduced easily by distraction of the wrist and digital pressure on the proximal pole of the scaphoid. The avulsed chip fragment was fixed to the lunate using a microscrew. The wrist was immobilised in a short arm cast for four weeks. The patient was then encouraged to start the range of motion exercise. Three months after
The preoperative x-ray hlms. (a) Lateral view showing the proximal pole of the scaphoid with small fracture displaced dorsally. Note the increased scapho-lunate angle and a minimal subluxation of the midcarpal joint. (b) Drawing of the above to show the slight backward sub&xation of the capitate. (c) P-A view showing increased scapho-lunate gap and foreshortened appearance of the scaphoid.
^ 368
:
THE JOURNAL
OF HAND SURGERY
ISOLATED
DORSAL DISLOCATION
OF THE SCAPHOID
Fig. 2 X-rays of the wrist one year after injury, showing no evidence of residual rotational subluxation or avascular necrosis of the scaphoid.
the operation he had no pain and was able to return to work. On examination one year after the injury, the grip strength in the left hand was 77% of that in the right (uninjured) hand. The range of motion of the left wrist was 60”of dorsiflexion, 50”of palmarflexion, 15”of radial deviation and 30” of ulnar deviation. There was no roentgenographic evidence of residual rotational subluxation or avascular necrosis of the scaphoid (Fig. 2).
References
Discussion Although our case required open reduction due to a twoweek delay between injury and diagnosis, the patient has no symptoms of instability of the wrist because the avulsion fracture of the scapho-lunate interosseous ligament was fixed securely with a microscrew. Maytield ( 1980) stated that carpal dislocations occurred in a sequential fashion due to progressive and specific ligamentous disruptions and were divided into four stages according to the degree of perilunar instability. He suggested that the isolated rotational subluxation of the scaphoid may be the first stage of a perilunar dislocation. It can occur without associated mid-carpal dislocation, so that the proximal pole of the scaphoid cannot extend over the dorsal rim of the radius due to the strong ligamentous attachments between the scaphoid, capitate and trapezium. If the scaphoid dislocates dorsally without fracture, it must accompany the capitate, resulting in a stage II perilunar dislocation. A careful examination of the lateral films of our case revealed minimal subluxation of the mid-carpal joint, suggesting the probable reason for the capitate dislocation. However, the pathomechanics of this injury did not seem to occur in the transition from the stage II perilunar dislocation because, at the time of VOL. 15B No. 3 AUGUST
the operation, the dorsal capsule, which is usually torn in a stage II perilunar dislocation, was found to be intact. This variation appears to be different from rotational subluxation of the scaphoid, in which closed reduction is easily achieved with the wrist in extension. This injury may be an intermediate condition between a stage I and stage II perilunar dislocation.
1996
AMAMILO. S. C.. UPPAL. R. andSAMUEL. A. W. (1985). Isolated Dislocation of Carpal Scaphoid. Journal of Hand Surgery, 10B: 3: 385-388. BUZBY, B. F. (1934). Isolated radial dislocation of a carpal scaphoid. Annals of surgery, loo: 553-555. CONNELL, M. C. and DYSON, R. P. (1955). Dislocationofthe carpal scaphoid. Report of a case.. Journal of Bone and Joint Surgery, 37B : 2: 252-253. HIGGS, S. L. (1930). Two Cases of Dislocation of Carpal Scaphoid. Proceedings ofthe Royal Society of Medicine, 23: 2: 1337-1339. KUTH, J. R. (1939). Isolated dislocation of the carpal navicular: A case report. Journal of Bone and Joint Surgery, 21: 479483. MAKI, N. J., CHUINARD, R. G. and D’AMROSIA, R. (1982). Isolated, Comnlete Radial Dislocation of the Scanhoid. A case renort and review of the liierature. Journalof Boneand Joint Surgery, 64A: 4:‘615-616. MAYFIELD, J. K., JOHNSON, R. P. and KILCOYNE, R. K. (1980). Carpal dislocations: Pathomechanics and progressive perilunar instability. Journal of Hand Surgery, 5 : 3 : 22624 I. MURAKAMI, Y. (1977)Dislocationofthecarpalscaphoid. The Hand9: 1: 7981. RUSSELL, T. B. (1949). Inter-carpal dislocations and fracture dislocations. A review of fifty-nine cases. Journal of Bone and Joint Surgery 31B: 4: 524 531. SCHLOSSBACH, T. (1954). Dislocation of the Carpal Navicular Bone Not Associated with Fracture. Journal of the Medical Society of New Jersey, 51: 12: 533-534. THOMAS, H. 0. (1977). Isolated dislocation of the carpal scaphoid. Acta Orthopaedica Scandinavica, 48 : 369-372. WOODD WALKER, G. B. (1943). Dislocation of the carpal scaphoid reduced by open operation. British Journal of Surgery, 30: 380-38 1. Dr. G. Inoue, Nagoya Nagoya, Japan. 0 1990 The British
University Schcol of Medicine, Division of
Society
for Surgery
Hand
Surgery
(Bun-in),
of the Hand
026~7681/W/0015-a368/$10.00
369
DORSAL
DISLOCATION
OF THE
SCAPHOID
G. INOUEand N. MAEDA From the Division of Hand Surgery, Nagoya University School of Medicine, Japan
A case of isolated dorsal dislocation of the scaphoid is reported. The patient was treated surgically with a good result. Journal of Hand Surgery (British VoIume, 1990) 15B: 368-369 While primary or secondary rotational subluxation of the scaphoid is not uncommon, isolated dislocation of this bone is extremely rare. In our review of the available English literature, there were 12 case-reports describing isolated dislocation of the scaphoid : five cases of anterior dislocation (Higgs, 1930; Kuth, 1939; Murakami, 1977; Thomas, 1977) and seven of radial dislocation (Buzy, 1934; Walker, 1943; Russell, 1949; Schlossbach, 1954; Connell and Dyson, 1955; Maki et al., 1982; Amamilo et al., 1985). Isolated dorsal dislocation of the scaphoid has not been previously described. Case report
An 18-year-old right-handed industrial worker was admitted to hospital complaining of pain and loss of motion of the wrist. 14 days earlier, his left wrist had been caught in a press machine which forced it into dorsiflexion. Examination found moderate swelling and tenderness on the dorsal aspect of the wrist. The neurovascular state of the hand was intact, but wrist motion was limited to 0” of dorsiflexion and 40” of palmartlexion.
Fig. 1
Lateral x-ray films (Fig. la) showed the proximal pole of the scaphoid with a small fracture displaced dorsally, extended over the dorsal rim of the radius. The scaphoid was rotated 70” to the long axis of the radius. The lunate was dorsiflexed and there was minimal subluxation of the mid-carpal joint. The P.-A. film (Fig. lb) showed an increased scapholunate gap and a foreshortened appearance of the scaphoid. After unsuccessful attempts at closed reduction, open reduction was performed through a dorsal approach. After the skin had been incised and the extensor tendons retracted, a bony prominence was evident beneath the dorsal wrist capsule which was still intact. When this capsule was incised, the proximal pole of the scaphoid was seen to be dislocated dorsally. The interosseous scapho-lunate ligament was avulsed from the dorsal aspect of the lunate with a chip fragment. The scaphoid was reduced easily by distraction of the wrist and digital pressure on the proximal pole of the scaphoid. The avulsed chip fragment was fixed to the lunate using a microscrew. The wrist was immobilised in a short arm cast for four weeks. The patient was then encouraged to start the range of motion exercise. Three months after
The preoperative x-ray hlms. (a) Lateral view showing the proximal pole of the scaphoid with small fracture displaced dorsally. Note the increased scapho-lunate angle and a minimal subluxation of the midcarpal joint. (b) Drawing of the above to show the slight backward sub&xation of the capitate. (c) P-A view showing increased scapho-lunate gap and foreshortened appearance of the scaphoid.
^ 368
:
THE JOURNAL
OF HAND SURGERY
ISOLATED
DORSAL DISLOCATION
OF THE SCAPHOID
Fig. 2 X-rays of the wrist one year after injury, showing no evidence of residual rotational subluxation or avascular necrosis of the scaphoid.
the operation he had no pain and was able to return to work. On examination one year after the injury, the grip strength in the left hand was 77% of that in the right (uninjured) hand. The range of motion of the left wrist was 60”of dorsiflexion, 50”of palmarflexion, 15”of radial deviation and 30” of ulnar deviation. There was no roentgenographic evidence of residual rotational subluxation or avascular necrosis of the scaphoid (Fig. 2).
References
Discussion Although our case required open reduction due to a twoweek delay between injury and diagnosis, the patient has no symptoms of instability of the wrist because the avulsion fracture of the scapho-lunate interosseous ligament was fixed securely with a microscrew. Maytield ( 1980) stated that carpal dislocations occurred in a sequential fashion due to progressive and specific ligamentous disruptions and were divided into four stages according to the degree of perilunar instability. He suggested that the isolated rotational subluxation of the scaphoid may be the first stage of a perilunar dislocation. It can occur without associated mid-carpal dislocation, so that the proximal pole of the scaphoid cannot extend over the dorsal rim of the radius due to the strong ligamentous attachments between the scaphoid, capitate and trapezium. If the scaphoid dislocates dorsally without fracture, it must accompany the capitate, resulting in a stage II perilunar dislocation. A careful examination of the lateral films of our case revealed minimal subluxation of the mid-carpal joint, suggesting the probable reason for the capitate dislocation. However, the pathomechanics of this injury did not seem to occur in the transition from the stage II perilunar dislocation because, at the time of VOL. 15B No. 3 AUGUST
the operation, the dorsal capsule, which is usually torn in a stage II perilunar dislocation, was found to be intact. This variation appears to be different from rotational subluxation of the scaphoid, in which closed reduction is easily achieved with the wrist in extension. This injury may be an intermediate condition between a stage I and stage II perilunar dislocation.
1996
AMAMILO. S. C.. UPPAL. R. andSAMUEL. A. W. (1985). Isolated Dislocation of Carpal Scaphoid. Journal of Hand Surgery, 10B: 3: 385-388. BUZBY, B. F. (1934). Isolated radial dislocation of a carpal scaphoid. Annals of surgery, loo: 553-555. CONNELL, M. C. and DYSON, R. P. (1955). Dislocationofthe carpal scaphoid. Report of a case.. Journal of Bone and Joint Surgery, 37B : 2: 252-253. HIGGS, S. L. (1930). Two Cases of Dislocation of Carpal Scaphoid. Proceedings ofthe Royal Society of Medicine, 23: 2: 1337-1339. KUTH, J. R. (1939). Isolated dislocation of the carpal navicular: A case report. Journal of Bone and Joint Surgery, 21: 479483. MAKI, N. J., CHUINARD, R. G. and D’AMROSIA, R. (1982). Isolated, Comnlete Radial Dislocation of the Scanhoid. A case renort and review of the liierature. Journalof Boneand Joint Surgery, 64A: 4:‘615-616. MAYFIELD, J. K., JOHNSON, R. P. and KILCOYNE, R. K. (1980). Carpal dislocations: Pathomechanics and progressive perilunar instability. Journal of Hand Surgery, 5 : 3 : 22624 I. MURAKAMI, Y. (1977)Dislocationofthecarpalscaphoid. The Hand9: 1: 7981. RUSSELL, T. B. (1949). Inter-carpal dislocations and fracture dislocations. A review of fifty-nine cases. Journal of Bone and Joint Surgery 31B: 4: 524 531. SCHLOSSBACH, T. (1954). Dislocation of the Carpal Navicular Bone Not Associated with Fracture. Journal of the Medical Society of New Jersey, 51: 12: 533-534. THOMAS, H. 0. (1977). Isolated dislocation of the carpal scaphoid. Acta Orthopaedica Scandinavica, 48 : 369-372. WOODD WALKER, G. B. (1943). Dislocation of the carpal scaphoid reduced by open operation. British Journal of Surgery, 30: 380-38 1. Dr. G. Inoue, Nagoya Nagoya, Japan. 0 1990 The British
University Schcol of Medicine, Division of
Society
for Surgery
Hand
Surgery
(Bun-in),
of the Hand
026~7681/W/0015-a368/$10.00
369