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Intraosseous ganglion of the pisiform bone
Intraosseous Ganglion of the Pisiform Bone--B. Helal and B. Vernon-Roberts
INTRAOSSEOUS GANGLION OF THE PISIFORM BONE B. H E L A L and B. VERNON-ROBERTS, London SUMMARY A ease report of a ganglion in the pisifo~rm bone, accompanied by pain and instability in the wrist joint. INTRODUCTION The occurrence of intraosseous ganglia in the bones of the hand is very rare. Of the the total of twenty-nine cases of intraosseous ganglia recorded in the literature (Hicks, 1956; Woods, 1961; Crabbe, 1966; Crane and Scarano, 1967; Seymour, 1968; Goldman and Friedman, 1969; Kaplan, 1971), only three occurred in the bones of the hand--in the scaphoid in one case and in the lunate in two cases. A communication with the joint cavity has been recorded in only two instances--one involving the lunate (Crabbe, 1966) and the other the scaphoid (Kaplan, 1971). We present our case here to call attention to the possibility of finding this very rare lesion, the intraosseous ganglion, in the carpal bones, to record the occurrence of this lesion in a previously unrecorded site, i.e. the pisiform bone; and to provide definite histological evidence that, in this case at least, the lesion communicated with the adjacent joint cavity. CASE REPORT The patient was a married woman aged fifty-eight years who worked as a housewife and secretary. Early in November 1972 she consulted an orthopaedic surgeon complaining of a swelling on the left wrist which had appeared after a fall on the wrist three months previously. His examination revealed the presence of a small cystic swelling on the volar aspect of the ulnar border of the left wrist, 4 cm distal to the head of the ulna, and also puffiness and tenderness on the radial border of the same wrist. Wrist movements were full and equal. Radiographs of the left wrist showed an enlarged and somewhat cystic pisiform with a small separate ossicle near the styloid process of the ulna (Figs. la, lb). Laboratory investigations, including sedimentation rate and rheumatoid factor, did not reveal any abnormality. Later in November 1972, the cystic swelling at the base of the hypothenar eminence was considered to be a ganglion and was removed. Histological examination of the excised tissue confirmed the presence of a typical ganglion, comprising fluid-containing cystic spaces surrounded by thick layers of fibrous tissue and other areas of myxoid changes in the connective tissues accompanied by varying stages of cystic degeneration. After this first operation, she continued to complain of pain and also of slight numbness of the skin over the distribution of the dorsal sensory branch of the ulnar nerve. The pain became worse during the subsequent year, and further radiographs revealed degenerative changes in the radial side of the wrist joint (Fig. 2). Since sp!intage of the wrist, manipulation, steroid injections and physiotherapy produced no lasting benefit, the patient was referred to one of us (B.H.) for advice and treatment. Helal, B. H., M.Ch.(Orth.), F.R.C.S.Ed., Broomer Cottage, Churchgate, Cheshunt, Herts. 150
The Hand--VoL 8
No. 2
1976
lntraosseous Ganglion of the Pisilorm Bone--B. Helal and B. Vernon-Roberts
Figs. 1A & lB. The cystic changes in the pisiform and the ossicle can be seen in both views of the left wrist. Fig. 2. Some narrowing of the joint space on the radial side of the wrist and some separation of the scaphoid and lunate can be seen. CLINICAL FINDINGS In December 1973, examination of the left wrist revealed a cystic swelling and tenderness located precisely to the pisotriquetral joint. Tenderness was also present between the radial styloid and the scaphoid. Compared with the asymptomatic normal right hand, extension, flexion and radial deviation of the left wrist were all reduced by 10°; ulnar deviation, supination and pronation were normal. There was diminished sensation over the area of distribution of the dorsal sensory branch of the ulnar nerve. RADIOLOGICAL FINDINGS Radiographs confirmed the presence of degenerative changes and some narrowing of the joint space between the radial styloid and the scaphoid, in addition to the enlarged and cystic pisiform and loose body first noted in 1972.
SURGICAL TREATMENT In January 1974, an enlarged pisiform was excised together with a cyst arising from the pisotriquetral joint and two loose bodies contained within that joint (Fig. 3). During the radial styloidectomy which was also performed, osteoarthrosic changes were observed in the articulating surfaces of the radius and scaphoid and some thickened synovial tissue was excised. HISTOPATHOLOGY Histological examination of the pisiform revealed advanced osteoarthrosic changes in the surviving articular cartilage. The body of the bone contained many large and small cystic cavities (Fig. 4) lined by flattened cells or, in some places, a definite layer of synovial-type cells. Immediately external to the lining of the cavities was a thin layer of collagenized fibrous tissue which separated the interior of the cavities from a network of trabecular bone having a mature lamellar structure. The tissues between the cavities exhibited a myxomatous appearance in many places, with areas of degeneration resulting in cyst formation (Fig. 5); these appearances of myxoid changes in connective tissues with The Hand--Vol. 8
No. 2
1976
151
Intraosseous Ganglion of the Pisiform Bone--B. Helal and B. Vernon-Roberts
Fig. 3. The excised pisiform bone showing degenerative changes of the articular surface and the two loose bodies which were found in the piso-triquetral joint. Fig, 4. Low-power view of section through pisiform showing large and small cystic spaces occupying body of the bone. Haematoxylin-eosin x 6.
Fig. 5. Cyst (C) arising by myxoid degeneration of connective tissues in pisiform. Pisotriquetral joint space can be seen at the bottom of the photomicrograph. Haematoxylin-eosin x 6. Fig. 6. Communication (arrow) between intraosseus cysts and joint space (JS) of pisotriquetral joint. Haematoxylin-eosin x 6. cystic cavities in various stages of evolution were similar to those seen in ganglia of extraosseous tissues. T h e pisiform was serially sectioned t h r o u g h o u t at 5 t~m intervals, and this revealed that a definite c o m m u n i c a t i o n existed between the ganglion and the synovial space of the piso-triquetral joint (Fig. 6); it also revealed that the majority of the larger cavities c o m m u n i c a t e d with each other. T h e fluid within these larger cavities exhibited the staining properties o f synovial fluid. 152
The Hand--Vol. 8
No. 2
1976
lntraosseous Ganglion o/the Pisiform Bone--B. Helal and B. Vernon-Roberts
The loose bodies from the piso-triquetral joint Space were composed predominantly of hyaline cartilage with widespread calcification and some ossification. The radial styloidectomy specimen exhibited advanced osteoarthosic changes in the cartilage. The synovial tissues showed reactive changes and contained fragments of calcific and cartilaginous debris consistent with advanced osteoarthrosis. P O S T - O P E R A T I V E COURSE
Post-operative radiographs revealed the presence of a gap between the scaphoid and the lunate, and she continued to have some discomfort on the radial side of the wrist for several months due to instability between the scaphoid and the lunate. By contrast, the pain which she had experienced on the ulnar side of the wrist disappeared immediately after the operation and no further symptoms recurred. When last seen in February 1975, the wrist was free of pain and the carpal instability was much less marked; while there was limitation of dorsiflexion to 40 ° and palmar flexion to 30 °, there was no limitation of radial or ulnar deviation, or of supination and pronation. DISCUSSION
The case presented here is of special interest, not only because it is the first recorded example of an intraosseous ganglion occuring within the pisiform bone of the hand, but also because the ganglion communicated with the adjacent joint space and co-existed with another ganglion in the adjacent connective tissues. It seems unlikely that the intraosseous ganglion in this case arose by extension from the more superficial lesion (or vice versa), since no evidence of intercommunication between the two sites was noted at the time of the first operation. That the intraosseous ganglion arose from the herniation of synovial membrane through a breach in the surface of the pisiform during the traumatic episode which appeared to have initiated the patient's symptoms clearly remains a possibility, but this is unlikely in the absence of pathological evidence of injury to the bone; although Landells (1953) reported two cases in which intraosseous synovial cysts occurred following trauma, one in an old ununited fracture of the carpal navicular and the other in a previously injured femoral head. Although a wide variety of pathogenic mechanisms have been promulgated and refuted, the genesis of parosteal and intraosseous ganglia remains obscure; we favour the concept that ganglia represent the degenerative and cystic stage of an antecedent mesenchymal proliferation with associated mucin production, and their propensity to form in close proximity to joints may suggest a similar reactivity of the mesenchymal derivatives of juxta-articular tissues whether they be within bone or soft tissue. We believe that the radial side wrist symptoms in this case occurred as a result of her initial injury and were due to dehiscence of the scapholunate ligaments causing carpal instability. REFERENCES
CRABBE, W. A. (1966) Intra-osseus Ganglia of Bone. British Journal of Surgery, 53: 15-17. CRANE, A. R. and SCARANO, J. J. (1967) Synovial cysts (Ganglia) of Bone--Report of Two Cases. Journal of Bone and Joint Surgery, 49A: 355-361. GOLDMAN, R. L. and FRIEDMAN, N. B. (1969) Ganglia ("Synovial" Cysts) Arising in Unusual Locations--Report of three Cases, one Primary in Bone. Clinical Orthopaedics and Related Research, 63: 184-189. The Hand--Vol. 8
No. 2
1976
153
lntraosseous Ganglion of the Pisiform Bone--B. Helal and B. Vernon-Roberts
HICKS, J. D. (1956) Synovial Cysts in Bone. The Australian and New Zealand Journal of Surgery, 26: 138-143. KAPLAN, E, B. (1971) Intraosseus Ganglion of the Scaphoid Bone of the Wrist--Case Report. Bulletin of the Hospital for Joint Diseases, 32: 50-53. LANDELLS, J. W. (1953) The Bone Cysts of Osteoarthritis. Journal of Bone and Joint Surgery, 35B: 643-649. SEYMOUR, N. (1968) Intraosseus Ganglia--Report of Two Cases. Journal of Bone and Joint Surgery, 50/3: 134-137. WOODS, C. G. (1961) Subchondral Bone Cysts. Journal of Bone and Joint Surgery, 43B: 758-766.
154
The Hand--Vol. 8
No. 2
1976
INTRAOSSEOUS GANGLION OF THE PISIFORM BONE B. H E L A L and B. VERNON-ROBERTS, London SUMMARY A ease report of a ganglion in the pisifo~rm bone, accompanied by pain and instability in the wrist joint. INTRODUCTION The occurrence of intraosseous ganglia in the bones of the hand is very rare. Of the the total of twenty-nine cases of intraosseous ganglia recorded in the literature (Hicks, 1956; Woods, 1961; Crabbe, 1966; Crane and Scarano, 1967; Seymour, 1968; Goldman and Friedman, 1969; Kaplan, 1971), only three occurred in the bones of the hand--in the scaphoid in one case and in the lunate in two cases. A communication with the joint cavity has been recorded in only two instances--one involving the lunate (Crabbe, 1966) and the other the scaphoid (Kaplan, 1971). We present our case here to call attention to the possibility of finding this very rare lesion, the intraosseous ganglion, in the carpal bones, to record the occurrence of this lesion in a previously unrecorded site, i.e. the pisiform bone; and to provide definite histological evidence that, in this case at least, the lesion communicated with the adjacent joint cavity. CASE REPORT The patient was a married woman aged fifty-eight years who worked as a housewife and secretary. Early in November 1972 she consulted an orthopaedic surgeon complaining of a swelling on the left wrist which had appeared after a fall on the wrist three months previously. His examination revealed the presence of a small cystic swelling on the volar aspect of the ulnar border of the left wrist, 4 cm distal to the head of the ulna, and also puffiness and tenderness on the radial border of the same wrist. Wrist movements were full and equal. Radiographs of the left wrist showed an enlarged and somewhat cystic pisiform with a small separate ossicle near the styloid process of the ulna (Figs. la, lb). Laboratory investigations, including sedimentation rate and rheumatoid factor, did not reveal any abnormality. Later in November 1972, the cystic swelling at the base of the hypothenar eminence was considered to be a ganglion and was removed. Histological examination of the excised tissue confirmed the presence of a typical ganglion, comprising fluid-containing cystic spaces surrounded by thick layers of fibrous tissue and other areas of myxoid changes in the connective tissues accompanied by varying stages of cystic degeneration. After this first operation, she continued to complain of pain and also of slight numbness of the skin over the distribution of the dorsal sensory branch of the ulnar nerve. The pain became worse during the subsequent year, and further radiographs revealed degenerative changes in the radial side of the wrist joint (Fig. 2). Since sp!intage of the wrist, manipulation, steroid injections and physiotherapy produced no lasting benefit, the patient was referred to one of us (B.H.) for advice and treatment. Helal, B. H., M.Ch.(Orth.), F.R.C.S.Ed., Broomer Cottage, Churchgate, Cheshunt, Herts. 150
The Hand--VoL 8
No. 2
1976
lntraosseous Ganglion of the Pisilorm Bone--B. Helal and B. Vernon-Roberts
Figs. 1A & lB. The cystic changes in the pisiform and the ossicle can be seen in both views of the left wrist. Fig. 2. Some narrowing of the joint space on the radial side of the wrist and some separation of the scaphoid and lunate can be seen. CLINICAL FINDINGS In December 1973, examination of the left wrist revealed a cystic swelling and tenderness located precisely to the pisotriquetral joint. Tenderness was also present between the radial styloid and the scaphoid. Compared with the asymptomatic normal right hand, extension, flexion and radial deviation of the left wrist were all reduced by 10°; ulnar deviation, supination and pronation were normal. There was diminished sensation over the area of distribution of the dorsal sensory branch of the ulnar nerve. RADIOLOGICAL FINDINGS Radiographs confirmed the presence of degenerative changes and some narrowing of the joint space between the radial styloid and the scaphoid, in addition to the enlarged and cystic pisiform and loose body first noted in 1972.
SURGICAL TREATMENT In January 1974, an enlarged pisiform was excised together with a cyst arising from the pisotriquetral joint and two loose bodies contained within that joint (Fig. 3). During the radial styloidectomy which was also performed, osteoarthrosic changes were observed in the articulating surfaces of the radius and scaphoid and some thickened synovial tissue was excised. HISTOPATHOLOGY Histological examination of the pisiform revealed advanced osteoarthrosic changes in the surviving articular cartilage. The body of the bone contained many large and small cystic cavities (Fig. 4) lined by flattened cells or, in some places, a definite layer of synovial-type cells. Immediately external to the lining of the cavities was a thin layer of collagenized fibrous tissue which separated the interior of the cavities from a network of trabecular bone having a mature lamellar structure. The tissues between the cavities exhibited a myxomatous appearance in many places, with areas of degeneration resulting in cyst formation (Fig. 5); these appearances of myxoid changes in connective tissues with The Hand--Vol. 8
No. 2
1976
151
Intraosseous Ganglion of the Pisiform Bone--B. Helal and B. Vernon-Roberts
Fig. 3. The excised pisiform bone showing degenerative changes of the articular surface and the two loose bodies which were found in the piso-triquetral joint. Fig, 4. Low-power view of section through pisiform showing large and small cystic spaces occupying body of the bone. Haematoxylin-eosin x 6.
Fig. 5. Cyst (C) arising by myxoid degeneration of connective tissues in pisiform. Pisotriquetral joint space can be seen at the bottom of the photomicrograph. Haematoxylin-eosin x 6. Fig. 6. Communication (arrow) between intraosseus cysts and joint space (JS) of pisotriquetral joint. Haematoxylin-eosin x 6. cystic cavities in various stages of evolution were similar to those seen in ganglia of extraosseous tissues. T h e pisiform was serially sectioned t h r o u g h o u t at 5 t~m intervals, and this revealed that a definite c o m m u n i c a t i o n existed between the ganglion and the synovial space of the piso-triquetral joint (Fig. 6); it also revealed that the majority of the larger cavities c o m m u n i c a t e d with each other. T h e fluid within these larger cavities exhibited the staining properties o f synovial fluid. 152
The Hand--Vol. 8
No. 2
1976
lntraosseous Ganglion o/the Pisiform Bone--B. Helal and B. Vernon-Roberts
The loose bodies from the piso-triquetral joint Space were composed predominantly of hyaline cartilage with widespread calcification and some ossification. The radial styloidectomy specimen exhibited advanced osteoarthosic changes in the cartilage. The synovial tissues showed reactive changes and contained fragments of calcific and cartilaginous debris consistent with advanced osteoarthrosis. P O S T - O P E R A T I V E COURSE
Post-operative radiographs revealed the presence of a gap between the scaphoid and the lunate, and she continued to have some discomfort on the radial side of the wrist for several months due to instability between the scaphoid and the lunate. By contrast, the pain which she had experienced on the ulnar side of the wrist disappeared immediately after the operation and no further symptoms recurred. When last seen in February 1975, the wrist was free of pain and the carpal instability was much less marked; while there was limitation of dorsiflexion to 40 ° and palmar flexion to 30 °, there was no limitation of radial or ulnar deviation, or of supination and pronation. DISCUSSION
The case presented here is of special interest, not only because it is the first recorded example of an intraosseous ganglion occuring within the pisiform bone of the hand, but also because the ganglion communicated with the adjacent joint space and co-existed with another ganglion in the adjacent connective tissues. It seems unlikely that the intraosseous ganglion in this case arose by extension from the more superficial lesion (or vice versa), since no evidence of intercommunication between the two sites was noted at the time of the first operation. That the intraosseous ganglion arose from the herniation of synovial membrane through a breach in the surface of the pisiform during the traumatic episode which appeared to have initiated the patient's symptoms clearly remains a possibility, but this is unlikely in the absence of pathological evidence of injury to the bone; although Landells (1953) reported two cases in which intraosseous synovial cysts occurred following trauma, one in an old ununited fracture of the carpal navicular and the other in a previously injured femoral head. Although a wide variety of pathogenic mechanisms have been promulgated and refuted, the genesis of parosteal and intraosseous ganglia remains obscure; we favour the concept that ganglia represent the degenerative and cystic stage of an antecedent mesenchymal proliferation with associated mucin production, and their propensity to form in close proximity to joints may suggest a similar reactivity of the mesenchymal derivatives of juxta-articular tissues whether they be within bone or soft tissue. We believe that the radial side wrist symptoms in this case occurred as a result of her initial injury and were due to dehiscence of the scapholunate ligaments causing carpal instability. REFERENCES
CRABBE, W. A. (1966) Intra-osseus Ganglia of Bone. British Journal of Surgery, 53: 15-17. CRANE, A. R. and SCARANO, J. J. (1967) Synovial cysts (Ganglia) of Bone--Report of Two Cases. Journal of Bone and Joint Surgery, 49A: 355-361. GOLDMAN, R. L. and FRIEDMAN, N. B. (1969) Ganglia ("Synovial" Cysts) Arising in Unusual Locations--Report of three Cases, one Primary in Bone. Clinical Orthopaedics and Related Research, 63: 184-189. The Hand--Vol. 8
No. 2
1976
153
lntraosseous Ganglion of the Pisiform Bone--B. Helal and B. Vernon-Roberts
HICKS, J. D. (1956) Synovial Cysts in Bone. The Australian and New Zealand Journal of Surgery, 26: 138-143. KAPLAN, E, B. (1971) Intraosseus Ganglion of the Scaphoid Bone of the Wrist--Case Report. Bulletin of the Hospital for Joint Diseases, 32: 50-53. LANDELLS, J. W. (1953) The Bone Cysts of Osteoarthritis. Journal of Bone and Joint Surgery, 35B: 643-649. SEYMOUR, N. (1968) Intraosseus Ganglia--Report of Two Cases. Journal of Bone and Joint Surgery, 50/3: 134-137. WOODS, C. G. (1961) Subchondral Bone Cysts. Journal of Bone and Joint Surgery, 43B: 758-766.
154
The Hand--Vol. 8
No. 2
1976