Chondroblastomas are rare (<1% of all bone tumors), benign, locally aggressive cartilaginous bone tumors that are more common in males (1.6–2:1) aged 10 to 25 years and may recur in 10% to 35% of patients.1,2 These tumors typically are observed in the epiphysis of long bones, especially the distal femur, proximal tibia, and proximal humerus.2 Chrondroblastomas usually spread through the physis to the metaphysis and spare the articular cartilage and joints.2 Some chondroblastomas metastasize (range, 0.8%–6%), comprising 1% of benign pulmonary metastases and some of these metastasis, although rare, have led to death.1–3 Treatment options include intralesional curettage and bone grafting, en bloc resection, and radiofrequency ablation.1,4 It is critical to ensure thorough curettage and even use of adjuvant treatments because recurrence can be seen with inadequate curettage.1 Commonly, recurrence is seen with indirect curettage procedures, such as femoral head lesions treated through a transcervical curettage (50%), when compared with open methods (31%).1
Less than 2% of chondroblastomas occur in the distal tibia, and literature search showed only 2 previous reports of intra-articular penetration from chondroblastoma in the knee and ankle.1,2,5 The current authors treated a patient who had chondroblastoma of the distal tibia that extended across the distal tibial articular cartilage into the ankle joint.
A 14-year-old boy had daily, sharp, left mid-anterior ankle pain (duration, 1.5 years), not associated with walking and unresolved with an ankle brace and nonsteroidal anti-inflammatory drugs. He had no trauma. History was noncontributory. Examination showed ankle effusion and anterior joint tenderness. No fever, erythema, or warmth were noted. Ankle motion was normal.
Radiographs and noncontrast computed tomography scan showed a small, well-circumscribed, central, lytic, distal tibial epiphyseal lesion from the physis to plafond, with surrounding sclerosis and articular penetration (Figure 1). Technetium-99m scintigraphy showed increased uptake at the lesion.
Computed tomography scans of the left ankle in sagittal (A), coronal (B), and axial (C) cuts delineating the well-circumscribed lytic lesion in the distal tibial epiphysis with erosion through the articular surface.
Treatment under general anesthesia included intralesional curettage, biopsy, and autologous iliac crest bone grafting through a mid-anterior epiphyseal bone tunnel with fluoroscopic guidance (Figure 2). The lesion had eroded into the ankle joint, with central plafond articular cartilage destruction. The lesion and sclerotic rim were curetted, avoiding the physis. Ankle arthrotomy was also performed to facilitate adequate curettage. Excised tissue fragments were bloody, white, and soft, and histology was consistent with chondroblastoma.6 An absorbable gelatin sponge (Gelfoam; Pfizer, Kalamazoo, Michigan) was placed in the lesion and turned toward the ankle to protect the articular surface and prevent graft extrusion. The epiphyseal defect and bone tunnel were packed with graft. Another piece of gelatin sponge was placed at the anterior cortex to prevent graft extrusion.
Intraoperative fluoroscopic images showing the intra-articular extension of the lesion, as well as the mid-anterior epiphyseal approach (A), used to complete the intralesional curettage (B) and bone grafting without damage to the physis.
Aftercare included short-leg cast (non–weight bearing, 1 week), walker boot (partial weight bearing, 2 weeks), full weight bearing by 6 weeks, and low-impact activities by 3 months. Pre-operative pain resolved by 4 weeks but recurred at 6 months. Radiographs and magnetic resonance imaging showed no recurrence of the epiphyseal lesion. At 11 months, ankle pain and crepitance persisted. Ankle arthroscopy showed intra-articular adhesions, but the plafond was intact and fully healed (Figure 3). He gradually resumed full activities. At 2 years, he was asymptomatic and fully active, with no growth disturbance, osteoarthritis, or lesion recurrence.
Ankle arthroscopy 11 months postoperatively revealing intact distal tibial articular cartilage without evidence of lesional demarcation.
The chondroblastoma was atypical because of the rare location in the distal tibial epiphysis and penetration through the distal tibial plafond. Symptoms resolved without recurrence, growth disturbance, or osteoarthritis after intralesional curettage and bone grafting, possibly because of the short follow-up (2 years) and good healing potential of articular lesions in children with open physes. Although intralesional curettage has been seen to be an effective treatment option for proximal tibial chondroblastomas,4 osteoarthritis is the highest complication after treatment of pediatric epiphyseal chondroblastomas at 77%, despite their skeletal immaturity and plasticity for remodeling, especially at the proximal femur.7 Complications may also include growth disturbance.1,8
Differential diagnosis of distal tibial and ankle tumors include giant cell tumor, aneurysmal bone cyst (concurrent with or secondary to chondroblastoma5,9), osteoid osteoma, osteoblastoma, chondroma, enchondroma, and clear cell chondrosarcoma.2,10 Clear cell chondrosarcoma usually occurs in older people (fifth to seventh decades), and epiphyseal giant cell tumor is unlikely in skeletally immature patients. The current patient had no characteristic findings of aneurysmal bone cyst (blood lakes, lining of cavitary spaces, or compressed fibroblasts and histiocytes).11 Although his lesion was less than 2 cm (making osteoid osteoma more likely than osteoblastoma), the symptoms did not respond to nonsteroidal anti-inflammatory drugs and there was no nidus observed on the computed tomography scan.11 Enchondroma was unlikely because the lesion was not expansile, did not contain intralesional calcifications, and was homogeneously lytic.11 Other epiphyseal lesions, such as acute infection, Brodie abscess, Trevor disease (dysplasia epiphysealis hemimelica), eosinophilic granuloma, and osteochondritis dissecans, were unlikely because he had no history of infection, inflammatory lesion, or trauma and because the sclerotic border of the lytic lesion was not characteristic of eosinophilic granuloma in long bones.2,11
The pink cartilage observed on histology may have been consistent with Trevor disease, chondroma, enchondroma, and chondroblastoma. However, Trevor disease was unlikely because there were no other epiphyseal lesions on imaging or similar complaints at other joints, involvement of the physis, or asymmetrical epiphyseal growth.2 The absence of chondroblastic cells and chicken-wire calcification likely represented sampling artifact because of the small size and destruction of bony architecture from curettage.
Articular surface penetration by the lesion caused treatment dilemma because of the risk of osteoarthritis after epiphyseal chondroblastoma.7 The absorbable gelatin sponge was successful in containing the bone graft in the epiphyseal cavity and avoiding postoperative graft extrusion into the ankle joint. Intra-articular gelatin sponges may serve as a conduit or scaffold for articular cartilage regeneration by functioning as a substrate for cell adhesion and proliferation12 and have been used in treating temporomandibular joint ankylosis.13 Although gelatin foam sponges may absorb within 4 to 6 weeks with minimal foreign body reaction or scarring, limited information is available about the sequelae of intra-articular use in large joints in humans, and the use of gelatin sponges to prevent intra-articular bone graft migration has not been approved by the US Food and Drug Administration.14
Treatment of epiphyseal chondroblastoma may be difficult because of articular involvement and the proximity to the physis, as in the current patient. Common adjuvant therapies, including cryotherapy, phenol, hydrogen peroxide, burring, and electrocautery, have varied success in decreasing recurrence and were not used because they extend circumferentially beyond the lesion and may cause irreversible injury to the physis and articular cartilage.1,15,16
The risk of chondroblastoma recurrence is higher in epiphyseal lesions and lesions near less active physes, such as the distal tibia.1 Nevertheless, the patient had no recurrence after 24 months and returned to full activities. The use of a mid-anterior epiphyseal bone tunnel under fluoroscopic guidance enabled intralesional excision without damage to the physis, despite the small size of the distal tibial epiphysis, and further disruption of the articular cartilage was avoided.
- Sailhan F, Chotel F, Parot RSOFOP. Chondroblastoma of bone in a pediatric population. J Bone Joint Surg Am. 2009;91(9):2159–2168. doi:10.2106/JBJS.H.00657 [CrossRef]
- Karkhur Y, Tiwari A, Verma T, Maini L. Unusual presentation of chondroblastoma mimicking Trevor's disease. J Postgrad Med. 2017;63(3):197–199. doi:10.4103/0022-3859.201414 [CrossRef]
- Rodgers WB, Mankin HJ. Metastatic malignant chondroblastoma. Am J Orthop (Belle Mead NJ). 1996;25(12):846–849.
- Cho HS, Park YK, Oh JH, Lee JH, Han I, Kim HS. Proximal tibia chondroblastoma treated with curettage and bone graft and cement use. Orthopedics. 2016;39(1):e80–e85. doi:10.3928/01477447-20151222-04 [CrossRef]
- Fan J, Li SZ, Mei J, Yu GR. Reconstruction with double pedicel fibular graft and ankle arthrodesis for aggressive chondroblastoma in the distal tibia. World J Surg Oncol. 2016;14:143. doi:10.1186/s12957-016-0839-z [CrossRef]
- Unni KK, Inwards CY. Benign chondroblastoma. In: Unni KK, Inwards CY, eds. Dahlin's Bone Tumors. Philadelphia, PA: Lippincott Williams and Wilkins; 2010:41–49.
- Farfalli GL, Slullitel PA, Muscolo DL, Ayerza MA, Aponte-Tinao LA. What happens to the articular surface after curettage for epiphyseal chondroblastoma? A report on functional results, arthritis, and arthroplasty. Clin Orthop Relat Res. 2017;475(3):760–766. doi:10.1007/s11999-016-4715-5 [CrossRef]
- Suneja R, Grimer RJ, Belthur M, et al. Chondroblastoma of bone: long term results and functional outcome after intralesional curettage. J Bone Joint Surg Br. 2005;87(7):974–978. doi:10.1302/0301-620X.87B7.16009 [CrossRef]
- Sasaki H, Nagano S, Shimada H, et al. Diagnosing and discriminating between primary and secondary aneurysmal bone cysts. Oncol Lett. 2017;13(4):2290–2296. doi:10.3892/ol.2017.5682 [CrossRef]
- Dhanda S, Menon S, Gulia A. Atypical giant chondroblastoma mimicking a chondrosarcoma. J Cancer Res Ther. 2015;11(3):660. doi:10.4103/0973-1482.139387 [CrossRef]
- Heck RK Jr., Benign/aggressive tumors of bone. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics. vol 1, 12th ed. Philadelphia, PA: Elsevier; 2013:887–908. doi:10.1016/B978-0-323-07243-4.00026-8 [CrossRef]
- Seo JP, Kambayashi Y, Itho M, et al. Effects of a synovial flap and gelatin/β-tricalcium phosphate sponges loaded with mesenchymal stem cells, bone morphogenetic protein-2, and platelet rich plasma on equine osteochondral defects. Res Vet Sci. 2015;101:140–143. doi:10.1016/j.rvsc.2015.06.014 [CrossRef]
- Pal US, Singh N, Malkunje LR, et al. Retrospective study of absorbable gelatin sponge soaked in triamcinolone acetonide as inter-positioning material in temporomandibular joint ankylosis in 350 patients. J Oral Biol Craniofac Res. 2013;3(1):20–24. doi:10.1016/j.jobcr.2012.11.006 [CrossRef]
- Pharmacia and Upjohn Company. Gelfoam: absorbable gelatin compressed sponge, http://www.pfizer.com/files/products/uspi_gelfoam_plus.pdf. Accessed April 22, 2018.
- Aboulafia AJ, Rosenbaum DH, Sicard-Rosenbaum L, Jelinek JS, Malawer MM. Treatment of large subchondral tumors of the knee with cryosurgery and composite reconstruction. Clin Orthop Relat Res. 1994;(307):189–199.
- Quint U, Müller RT, Müller G. Characteristics of phenol: instillation in intralesional tumor excision of chondroblastoma, osteoclastoma and enchondroma. Arch Orthop Trauma Surg. 1998;117(1–2):43–46. doi:10.1007/BF00703438 [CrossRef]