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Idiopathic avascular necrosis of the capitate
IDIOPATHIC AVASCULAR
N E C R O S I S OF T H E C A P I T A T E
S. KUTTY and J. CURTIN
From the Department of Orthopaedics, St Mary's" Orthopaedic Hospital, Gurranabraher, Cork, Republic of Ireland Idiopathic avascular necrosis (AVN) of the capitate is rare. A 44-year-old woman presented with chronic pain in her dominant wrist without a history of trauma. Clinical and standard radiological examination were initially inconclusive, while MRI was diagnostic. Mid-carpal arthrodesis gave a satisfactory short term result, and the long term result is awaited. Idiopathic AVN of the capitate should be included in the differential diagnosis of chronic wrist pain.
Journal of Hand Surgery (British and European Volume, 1995) 20B: 3:402-404 However, there were some non-specific changes seen within the capitate in the form of a lucent zone and a circular sclerotic area adjacent to it (Fig 1). As her symptoms persisted for over 6 months an orthopaedic consultation was sought. Physical examination at this stage showed a dorsal carpal swelling with a tender capitate and terminal limitation of wrist movements in all directions. Plain radiographs showed patchy osteosclerosis of the capitate with no collapse (Fig 2), while on isotope scanning the carpus demonstrated increased uptake (Fig 3). MRI scanning (GE Signa, 1.5 Tesla) of the wrist showed areas of decreased signal intensity within the capitate (Fig 4), indicating avascular necrosis (AVN). An open biopsy was carried out, and on histopathological examination characteristic anucleate lacunae were seen in bony trabeculae along with degenerative changes within the marrow fat, diagnostic of AVN (Fig 5).
CASE REPORT A 44-year-old housewife was seen by her General Practitioner with an 11-month history of an insidious onset dominant right wrist pain and discomfort in her right forearm, without a history of trauma or inflammation. Clinical examination and plain radiography did not point to any specific bone or joint pathology.
Fig 1
Fig 2
X-ray of the wrist, showing non-specific lucent lesion in the capitate. 402
X-ray of the wrist, 6 months later, showing osteosclerosis of the capitate, suggestive of avascular necrosis.
IDIOPATHIC AVASCULAR NECROSIS
403
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Isotope bone scan, showing non-specific increased uptake in the carpus.
Definitive operative treatment was undertaken in the form of excision of the avascular capitate and autogenous corticocancellous iliac crest grafting in the distal carpal row to achieve a midcarpal arthrodesis, and the short term results have been satisfactory. DISCUSSION Idiopathic AVN of the capitate is a rare condition and was first reported by J6nsson in 1942. Trauma, in a single major episode.or in repeated minor forms, may produce AVN of the capitate as shown in previous case reports (Lowry and Cord, 1981; Rahme, 1983; Murakami and Nakajima, 1984). AVN of the capitate has also been reported in association with dorsal instability on extension of the carpus (Newman and Watt, 1980) and secondary to vibration (James and Burke, 1984). Bolton-Maggs et al (1984) concluded that the condition was rare because a combination of factors was needed to produce it: an anomalous blood supply; inbuilt carpal instability and trauma. Intraosseous vascular supply of the capitate has been well studied and documented (Panagis et al, 1983). In Fig 4
M R image of the wrist, showing decreased signal intensity from the capitate.
404
Fig 5
THE JOURNAL OF HAND SURGERY VOL. 20B No. 3 JUNE 1995
P h o t o m i c r o g r a p h s h o w i n g e m p t y lacunae in necrotic b o n e and degenerate m a r r o w - H a n d E, x 480.
their study, the capitate along with the scaphoid and 20% of lunates fell into the group in which large areas of bone were supplied by a single nutrient vessel. In 67% of specimens of capitate, the head and neck were supplied by dorsal nutrient vessels, and by palmar vessels in the other 33%. Intraosseous anastomosis between the dorsal and palmar nutrient vessels was found only in 30% of specimens. Thus the capitate was said to be at risk of AVN based on its intraosseous vascular pattern. However, the rarity of AVN of the capitate may relate in part to its protected position in the centre of the distal carpal row (James and Burke, 1984). In the case presented, no definite aetiological factor could be detected in the pathogenesis of the condition. Standard radiological examination was inconclusive, while isotope scanning was helpful in localizing the pathology to the carpus. MRI was sensitive enough to suggest the diagnosis of AVN of the capitate, and as recommended (Cristiani et al, 1990) should be the imaging modality of choice in all cases of chronic unexplained wrist pain. Because the condition is rare, treatment has been limited and to a certain extent experimental. Mid-carpal arthrodesis has been carried out in this patient with a satisfactory short term result.
Acknowledgement The authors wish to thank Dr Margaret Sheehan, Senior Registrar, Department of Pathology, Cork Regional Hospital, Cork, for her assistance in the preparation of histopathology slides.
References BOLTON-MAGGS, B. G., HELAL, B. H. and REVELL, P. A. (1984). Bilateral avascular necrosis of the capitate: A case report and a review of the literature. Journal of Bone and Joint Surgery, 66B: 4:557 559. CRISTIANI, G., CEROFOLINI, E., SQUARZINA, P. B., ZANASI, S., LEONI, A., ROMAGNOLI, R. and CAROLI, A. (1990). Evaluation of ischaemic necrosis of carpal bones by magnetic resonance imaging. Journal of Hand Surgery, 15B: 2: 249-255. JAMES, E. T. R. and BURKE, F. D. (1984). Vibration disease of the capitate. Journal of Hand Surgery, 9B: 2: 169-170. JONSSON, G. (1942). Aseptic bone necrosis of the os capitatum (os magnum). Acta Radiologica, 23: 562-564. LOWRY, W. E. and CORD, S. A. (1981). Traumatic avascular necrosis of the capitate bone: Case report. Journal of Hand Surgery, 6A: 3:245 248. MURAKAMI, S. and NAKAJIMA, H. (1984). Aseptic necrosis of the capitate bone in two gymnasts. American Journal of Sports Medicine, 12: 2: 170-173. NEWMAN, J. H. and WATT, I. (1980). Avascular necrosis of the capitate and dorsal dorsi-flexion instability. The Hand, 12: 2: 176-178. PANAGIS, J. S., GELBERMAN, R. H., TALEISNIK, J. and BAUMGAERTNER, M. (1983). The arterial anatomy of the human carpus. Part II: The intraosseous vascularity. Journal of Hand Surgery, 8: 4: 375-382. RAHME, H. (1983). Idiopathic avascular necrosis of the capitate bone: Case report. Hand, 15: 3: 274-275. Accepted: 30 November 1994 Satish Kutty, MS, DNB, MCh(Orth), 57 Monalee Manor, Knocknacarra, Salthill, Galway, Republic of Ireland. © 1995 The British Society for Surgery of the Hand
N E C R O S I S OF T H E C A P I T A T E
S. KUTTY and J. CURTIN
From the Department of Orthopaedics, St Mary's" Orthopaedic Hospital, Gurranabraher, Cork, Republic of Ireland Idiopathic avascular necrosis (AVN) of the capitate is rare. A 44-year-old woman presented with chronic pain in her dominant wrist without a history of trauma. Clinical and standard radiological examination were initially inconclusive, while MRI was diagnostic. Mid-carpal arthrodesis gave a satisfactory short term result, and the long term result is awaited. Idiopathic AVN of the capitate should be included in the differential diagnosis of chronic wrist pain.
Journal of Hand Surgery (British and European Volume, 1995) 20B: 3:402-404 However, there were some non-specific changes seen within the capitate in the form of a lucent zone and a circular sclerotic area adjacent to it (Fig 1). As her symptoms persisted for over 6 months an orthopaedic consultation was sought. Physical examination at this stage showed a dorsal carpal swelling with a tender capitate and terminal limitation of wrist movements in all directions. Plain radiographs showed patchy osteosclerosis of the capitate with no collapse (Fig 2), while on isotope scanning the carpus demonstrated increased uptake (Fig 3). MRI scanning (GE Signa, 1.5 Tesla) of the wrist showed areas of decreased signal intensity within the capitate (Fig 4), indicating avascular necrosis (AVN). An open biopsy was carried out, and on histopathological examination characteristic anucleate lacunae were seen in bony trabeculae along with degenerative changes within the marrow fat, diagnostic of AVN (Fig 5).
CASE REPORT A 44-year-old housewife was seen by her General Practitioner with an 11-month history of an insidious onset dominant right wrist pain and discomfort in her right forearm, without a history of trauma or inflammation. Clinical examination and plain radiography did not point to any specific bone or joint pathology.
Fig 1
Fig 2
X-ray of the wrist, showing non-specific lucent lesion in the capitate. 402
X-ray of the wrist, 6 months later, showing osteosclerosis of the capitate, suggestive of avascular necrosis.
IDIOPATHIC AVASCULAR NECROSIS
403
,ii!ili7
= 5,:}::::: : :;:
:? ,:,
:::77:: ::;;;;;=:A=7 L=;::
::;;i .-:: ::,
::;: ::
[ [ }
Fig 3
=
::
: ::;:
::
::
; . . . .
==
Isotope bone scan, showing non-specific increased uptake in the carpus.
Definitive operative treatment was undertaken in the form of excision of the avascular capitate and autogenous corticocancellous iliac crest grafting in the distal carpal row to achieve a midcarpal arthrodesis, and the short term results have been satisfactory. DISCUSSION Idiopathic AVN of the capitate is a rare condition and was first reported by J6nsson in 1942. Trauma, in a single major episode.or in repeated minor forms, may produce AVN of the capitate as shown in previous case reports (Lowry and Cord, 1981; Rahme, 1983; Murakami and Nakajima, 1984). AVN of the capitate has also been reported in association with dorsal instability on extension of the carpus (Newman and Watt, 1980) and secondary to vibration (James and Burke, 1984). Bolton-Maggs et al (1984) concluded that the condition was rare because a combination of factors was needed to produce it: an anomalous blood supply; inbuilt carpal instability and trauma. Intraosseous vascular supply of the capitate has been well studied and documented (Panagis et al, 1983). In Fig 4
M R image of the wrist, showing decreased signal intensity from the capitate.
404
Fig 5
THE JOURNAL OF HAND SURGERY VOL. 20B No. 3 JUNE 1995
P h o t o m i c r o g r a p h s h o w i n g e m p t y lacunae in necrotic b o n e and degenerate m a r r o w - H a n d E, x 480.
their study, the capitate along with the scaphoid and 20% of lunates fell into the group in which large areas of bone were supplied by a single nutrient vessel. In 67% of specimens of capitate, the head and neck were supplied by dorsal nutrient vessels, and by palmar vessels in the other 33%. Intraosseous anastomosis between the dorsal and palmar nutrient vessels was found only in 30% of specimens. Thus the capitate was said to be at risk of AVN based on its intraosseous vascular pattern. However, the rarity of AVN of the capitate may relate in part to its protected position in the centre of the distal carpal row (James and Burke, 1984). In the case presented, no definite aetiological factor could be detected in the pathogenesis of the condition. Standard radiological examination was inconclusive, while isotope scanning was helpful in localizing the pathology to the carpus. MRI was sensitive enough to suggest the diagnosis of AVN of the capitate, and as recommended (Cristiani et al, 1990) should be the imaging modality of choice in all cases of chronic unexplained wrist pain. Because the condition is rare, treatment has been limited and to a certain extent experimental. Mid-carpal arthrodesis has been carried out in this patient with a satisfactory short term result.
Acknowledgement The authors wish to thank Dr Margaret Sheehan, Senior Registrar, Department of Pathology, Cork Regional Hospital, Cork, for her assistance in the preparation of histopathology slides.
References BOLTON-MAGGS, B. G., HELAL, B. H. and REVELL, P. A. (1984). Bilateral avascular necrosis of the capitate: A case report and a review of the literature. Journal of Bone and Joint Surgery, 66B: 4:557 559. CRISTIANI, G., CEROFOLINI, E., SQUARZINA, P. B., ZANASI, S., LEONI, A., ROMAGNOLI, R. and CAROLI, A. (1990). Evaluation of ischaemic necrosis of carpal bones by magnetic resonance imaging. Journal of Hand Surgery, 15B: 2: 249-255. JAMES, E. T. R. and BURKE, F. D. (1984). Vibration disease of the capitate. Journal of Hand Surgery, 9B: 2: 169-170. JONSSON, G. (1942). Aseptic bone necrosis of the os capitatum (os magnum). Acta Radiologica, 23: 562-564. LOWRY, W. E. and CORD, S. A. (1981). Traumatic avascular necrosis of the capitate bone: Case report. Journal of Hand Surgery, 6A: 3:245 248. MURAKAMI, S. and NAKAJIMA, H. (1984). Aseptic necrosis of the capitate bone in two gymnasts. American Journal of Sports Medicine, 12: 2: 170-173. NEWMAN, J. H. and WATT, I. (1980). Avascular necrosis of the capitate and dorsal dorsi-flexion instability. The Hand, 12: 2: 176-178. PANAGIS, J. S., GELBERMAN, R. H., TALEISNIK, J. and BAUMGAERTNER, M. (1983). The arterial anatomy of the human carpus. Part II: The intraosseous vascularity. Journal of Hand Surgery, 8: 4: 375-382. RAHME, H. (1983). Idiopathic avascular necrosis of the capitate bone: Case report. Hand, 15: 3: 274-275. Accepted: 30 November 1994 Satish Kutty, MS, DNB, MCh(Orth), 57 Monalee Manor, Knocknacarra, Salthill, Galway, Republic of Ireland. © 1995 The British Society for Surgery of the Hand