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Intra-articular osteochondroma of the ankle joint
Intra-articular Osteochondroma of the Ankle Joint Intra-articular osteochondroma is a rare entity that appears as a single giant osteocartilaginous loose body in a joint cavity. The few reported cases of intra-articular osteochondroma have occurred in the knee joint. We report the case of a large osteochondral loose body in the ankle joint of a 10-year-old girl and discuss the origin of the osteochondral tumor. (The Journal of Foot & Ankle Surgery 37(1):66-68, 1998) Key words: intra-articular osteochondroma, ankle joint, osteochondromatosis
Toshihiko Yamashita, MD, PhD 1 ,2 Naotoshi Sakamoto, MD Ichiro Ishikawa, MD
Masamichi Usui, MD, PhD Yasunori Fujisawa, MD, PhD 3
Osteochondromatosis presents as multiple chondral or osteochondral intrasynovial nodules, which may progress to a formation of an intra-articular loose body. The multiple nodules usually are small, rarely reaching a diameter of a centimeter (1). Much more uncommon is the presence of a single giant osteochondral intraarticular tumor, which is either pedunculated or free in the joint space. Such a loose body has been termed giant intra-articular osteochondroma by Sarmiento and Elkins (2). We treated a young girl with a large osteochondral loose body in the ankle joint.
fragment were performed. Arthroscopy showed intact joint cartilage and no synovitis in the ankle joint. At surgery, a curved 7-cm. incision was made over the posteromedial aspect of the ankle, and the joint capsule was opened. A large osteocartilaginous mass, which had a fine fibroareolar connective tissue attachment to the capsule, was easily removed from the joint cavity. No metaplastic lesions were found in the synovial membrane. The gross appearance of the osteocartilaginous tumor was an irregular nodular mass that consisted of a glistening white cartilaginous part and a brown bony part. The specimen measured 3.5 X 2.0 X 0.5 em, The cartilaginous part appeared lobular, and a small chondral fragment was easily separated from the tumor (Fig. 3). Microscopic investigation revealed that the bony part was composed of cancellous bone, and the surface facing the cartilaginous part was covered with cartilaginous tissue. The cartilaginous part consisted of lobular chondromas. The bony part and the cartilaginous part were connected by loose fibrous tissue. There was no evidence of cellular atypia (Fig. 4). The patient had an uneventful recovery and regained normal function of the ankle joint. She was followed for 2 years after the operation and has full range of motion with no pain from any activity. The latest radiographs show no evidence of recurrence.
Case Report
A lO-year-old girl was referred to us because of swelling and pain in the right ankle joint. When she was 5 years old, the patient had been examined by another doctor for a minor sprain of the right ankle. Radiographs at that time showed small free bodies at the posterosuperior aspect of the talus (Fig. 1), which were ignored by the doctor. Since that time, she occasionally felt ankle joint pain, especially after running, and noticed gradually increased swelling of the posterior aspect of the ankle joint. She had a tender mass in the posterior aspect and a decreased range of plantar flexion of the ankle. Radiographs taken at our clinic showed a large osseous mass at the posterior aspect of the talus (Fig. 2). Arthroscopy and subsequent surgical excision of the From the 'Department of Orthopedic Surgery, Sapporo Medical University, Sapporo, Japan and the 3Department of Pathology, Muroran City General Hospital, Muroran, Japan. 2Address correspondence to: Department of Orthopedic Surgery, Sapporo Medical University, South 1, West 16, Chuo-ku, Sapporo 060, Japan. Fax: 81-11-641-6026. The Journal of Foot & Ankle Surgery 1067-2516/98/3701-0066$4.00/0 Copyright © 1998 by the American College of Foot and Ankle Surgeons
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THE JOURNAL OF FOOT & ANKLE SURGERY
Discussion
Osteocartilaginous loose bodies inside the joint are generally thought to arise either from pre-existing bone or cartilage, that is, osteochondral fractures or osteochondritis dissecans, or from nonosseous structures such as a synovium or capsule. The latter entity, called synovial osteochondromatosis, consists of either focal or diffuse proliferation of intrasynovial chondral or osteo-
FIGURE 1 Lateral roentgenogram of the ankle when the patient
FIGURE 2 Lateral roentgenogram of the ankle when the patient
was 5 years old, showing small intra-articular osseous fragments .
was 10 years old, show lnq the large intra-articular osseous mass.
chondral nodules, which mayor may not progress to the formation of a single loose body. The size of an individualloose body found in cases of synovial osteochondromatosis is rarely greater than 1 em. in diameter. However, there have been a few reports of a single giant chondral or osteochondral tumor in the joint cavity (1-3). Sarmiento and Elkins (2) reported a case that showed a large intra-articular osteocartilaginous loose body in the knee joint and termed it giant intra-articular osteochondroma. Milgram and Dunn (1) also int erpreted a case that presented an osteochondral tumor and two cases that presented chondral tumors in the knee joint as intra-articular osteochondroma and intraarticular chondromas, respectively. The present case is similar to these reports because in our patient the tumor was a single intra-articular osteocartilaginous loose body with a diameter of more than 3 cm., which is very large relative to a child's ankle joint. Use of the terms osteochondroma and chondroma for these lesions is confusing because those terms usually describe the much more common lesions that arise from bone. Milgram and Dunn (1) termed para-articular lesions that arise as a result of metaplasia within soft
FIGURE 3 Photograph of the removed gross intra-articular osteocartilaginous tumor . White cartilaginous lobules are seen. One divis ion of the scale indicates 5 mm.
tissues near the joints intra-articular osteochondroma and chondroma. Sarmiento and Elkins (2) speculated that loose bodies arise from an area of synovial metaplasia and grow slowly inside the joint for many years. These lesions are distinctly different entities from the VOLUME 37, NUMBER 1, 1998
67
FIGURE 4 Low-power photomicrograph of a representative section of the removed tumor. The bony part (left half) and the cartilaginous part (right half) are connected with thin connective tissue. The surface of the bony part facing the cartilaginous part is covered with cartilaginous tissue. The cartilaginous part appears to be chondroma made up of united chondral nodules (H&E x 100).
common osteochondroma that is attached by either a broad or narrow stalk to a cortical surface of a bone. The tumor in our patient consisted of a bony part and a cartilaginous part that were connected to each other by thin connective tissue. The bony part, which showed histological features of osteochondroma, should be called intra-articular osteochondroma. In contrast, the cartilaginous part, which is composed of small united chondral nodules, may be called intra-articular chondroma. To our knowledge, there has been no previous report of intra-articular osteochondroma or intra-articular chondroma in the ankle joint. In our patient the intra-articular tumor grew gradually
68
THE JOURNAL OF FOOT & ANKLE SURGERY
over a 5-year period. The cartilaginous part of the tumor seemed to be formed by small united masses of synovial chondromatosis. The origin of the bony part, however, is not clear. It could also have been formed by the union of small nodules of osteochondromatosis, because small intra-articular osseous fragments were seen in a radiograph taken when the patient was 5 years old. Another possible origin of the lesion is an osteochondral fragment from the articular surface of the posterosuperior edge of the talus or the posteroinferior edge of the tibia that may have been avulsed into the joint and may have grown either because of nourishment by synovial fluid or because of blood supply from its residual attachment to the synovial membrane (2). However, this is a less likely possibility because during surgery the articular surfaces of the tibia and fibula were observed to be covered by normal hyaline cartilage. Thus, the present case provided us clues to the origin of the intra-articular osteochondroma. Acknowledgment
The authors thank Professor Seiichi Ishii of the Department of Orthopedic Surgery, Sapporo Medical University for his critical review of the manuscript. References 1. Milgram, J. W., Dunn, E. J. Para-articular chondromas and osteochondromas: a report of three cases. Clin. Orthop. Relat. Res. 148:147-151, 1980. 2. Sarmiento, A., Elkins, R. W. Giant intra-articular osteochondroma of the knee. A case report. J. Bone Joint Surg. 57:560-561, 1975. 3. Hagan, P. F., Schoenecker, P. L.: Para-articular osteochondroma: a case report. Am. J. Orthop. 24:65-67, 1995.
Toshihiko Yamashita, MD, PhD 1 ,2 Naotoshi Sakamoto, MD Ichiro Ishikawa, MD
Masamichi Usui, MD, PhD Yasunori Fujisawa, MD, PhD 3
Osteochondromatosis presents as multiple chondral or osteochondral intrasynovial nodules, which may progress to a formation of an intra-articular loose body. The multiple nodules usually are small, rarely reaching a diameter of a centimeter (1). Much more uncommon is the presence of a single giant osteochondral intraarticular tumor, which is either pedunculated or free in the joint space. Such a loose body has been termed giant intra-articular osteochondroma by Sarmiento and Elkins (2). We treated a young girl with a large osteochondral loose body in the ankle joint.
fragment were performed. Arthroscopy showed intact joint cartilage and no synovitis in the ankle joint. At surgery, a curved 7-cm. incision was made over the posteromedial aspect of the ankle, and the joint capsule was opened. A large osteocartilaginous mass, which had a fine fibroareolar connective tissue attachment to the capsule, was easily removed from the joint cavity. No metaplastic lesions were found in the synovial membrane. The gross appearance of the osteocartilaginous tumor was an irregular nodular mass that consisted of a glistening white cartilaginous part and a brown bony part. The specimen measured 3.5 X 2.0 X 0.5 em, The cartilaginous part appeared lobular, and a small chondral fragment was easily separated from the tumor (Fig. 3). Microscopic investigation revealed that the bony part was composed of cancellous bone, and the surface facing the cartilaginous part was covered with cartilaginous tissue. The cartilaginous part consisted of lobular chondromas. The bony part and the cartilaginous part were connected by loose fibrous tissue. There was no evidence of cellular atypia (Fig. 4). The patient had an uneventful recovery and regained normal function of the ankle joint. She was followed for 2 years after the operation and has full range of motion with no pain from any activity. The latest radiographs show no evidence of recurrence.
Case Report
A lO-year-old girl was referred to us because of swelling and pain in the right ankle joint. When she was 5 years old, the patient had been examined by another doctor for a minor sprain of the right ankle. Radiographs at that time showed small free bodies at the posterosuperior aspect of the talus (Fig. 1), which were ignored by the doctor. Since that time, she occasionally felt ankle joint pain, especially after running, and noticed gradually increased swelling of the posterior aspect of the ankle joint. She had a tender mass in the posterior aspect and a decreased range of plantar flexion of the ankle. Radiographs taken at our clinic showed a large osseous mass at the posterior aspect of the talus (Fig. 2). Arthroscopy and subsequent surgical excision of the From the 'Department of Orthopedic Surgery, Sapporo Medical University, Sapporo, Japan and the 3Department of Pathology, Muroran City General Hospital, Muroran, Japan. 2Address correspondence to: Department of Orthopedic Surgery, Sapporo Medical University, South 1, West 16, Chuo-ku, Sapporo 060, Japan. Fax: 81-11-641-6026. The Journal of Foot & Ankle Surgery 1067-2516/98/3701-0066$4.00/0 Copyright © 1998 by the American College of Foot and Ankle Surgeons
66
THE JOURNAL OF FOOT & ANKLE SURGERY
Discussion
Osteocartilaginous loose bodies inside the joint are generally thought to arise either from pre-existing bone or cartilage, that is, osteochondral fractures or osteochondritis dissecans, or from nonosseous structures such as a synovium or capsule. The latter entity, called synovial osteochondromatosis, consists of either focal or diffuse proliferation of intrasynovial chondral or osteo-
FIGURE 1 Lateral roentgenogram of the ankle when the patient
FIGURE 2 Lateral roentgenogram of the ankle when the patient
was 5 years old, showing small intra-articular osseous fragments .
was 10 years old, show lnq the large intra-articular osseous mass.
chondral nodules, which mayor may not progress to the formation of a single loose body. The size of an individualloose body found in cases of synovial osteochondromatosis is rarely greater than 1 em. in diameter. However, there have been a few reports of a single giant chondral or osteochondral tumor in the joint cavity (1-3). Sarmiento and Elkins (2) reported a case that showed a large intra-articular osteocartilaginous loose body in the knee joint and termed it giant intra-articular osteochondroma. Milgram and Dunn (1) also int erpreted a case that presented an osteochondral tumor and two cases that presented chondral tumors in the knee joint as intra-articular osteochondroma and intraarticular chondromas, respectively. The present case is similar to these reports because in our patient the tumor was a single intra-articular osteocartilaginous loose body with a diameter of more than 3 cm., which is very large relative to a child's ankle joint. Use of the terms osteochondroma and chondroma for these lesions is confusing because those terms usually describe the much more common lesions that arise from bone. Milgram and Dunn (1) termed para-articular lesions that arise as a result of metaplasia within soft
FIGURE 3 Photograph of the removed gross intra-articular osteocartilaginous tumor . White cartilaginous lobules are seen. One divis ion of the scale indicates 5 mm.
tissues near the joints intra-articular osteochondroma and chondroma. Sarmiento and Elkins (2) speculated that loose bodies arise from an area of synovial metaplasia and grow slowly inside the joint for many years. These lesions are distinctly different entities from the VOLUME 37, NUMBER 1, 1998
67
FIGURE 4 Low-power photomicrograph of a representative section of the removed tumor. The bony part (left half) and the cartilaginous part (right half) are connected with thin connective tissue. The surface of the bony part facing the cartilaginous part is covered with cartilaginous tissue. The cartilaginous part appears to be chondroma made up of united chondral nodules (H&E x 100).
common osteochondroma that is attached by either a broad or narrow stalk to a cortical surface of a bone. The tumor in our patient consisted of a bony part and a cartilaginous part that were connected to each other by thin connective tissue. The bony part, which showed histological features of osteochondroma, should be called intra-articular osteochondroma. In contrast, the cartilaginous part, which is composed of small united chondral nodules, may be called intra-articular chondroma. To our knowledge, there has been no previous report of intra-articular osteochondroma or intra-articular chondroma in the ankle joint. In our patient the intra-articular tumor grew gradually
68
THE JOURNAL OF FOOT & ANKLE SURGERY
over a 5-year period. The cartilaginous part of the tumor seemed to be formed by small united masses of synovial chondromatosis. The origin of the bony part, however, is not clear. It could also have been formed by the union of small nodules of osteochondromatosis, because small intra-articular osseous fragments were seen in a radiograph taken when the patient was 5 years old. Another possible origin of the lesion is an osteochondral fragment from the articular surface of the posterosuperior edge of the talus or the posteroinferior edge of the tibia that may have been avulsed into the joint and may have grown either because of nourishment by synovial fluid or because of blood supply from its residual attachment to the synovial membrane (2). However, this is a less likely possibility because during surgery the articular surfaces of the tibia and fibula were observed to be covered by normal hyaline cartilage. Thus, the present case provided us clues to the origin of the intra-articular osteochondroma. Acknowledgment
The authors thank Professor Seiichi Ishii of the Department of Orthopedic Surgery, Sapporo Medical University for his critical review of the manuscript. References 1. Milgram, J. W., Dunn, E. J. Para-articular chondromas and osteochondromas: a report of three cases. Clin. Orthop. Relat. Res. 148:147-151, 1980. 2. Sarmiento, A., Elkins, R. W. Giant intra-articular osteochondroma of the knee. A case report. J. Bone Joint Surg. 57:560-561, 1975. 3. Hagan, P. F., Schoenecker, P. L.: Para-articular osteochondroma: a case report. Am. J. Orthop. 24:65-67, 1995.