Journal of Orthopedic Oncology
Open Access

About 85% of cases of Aneurysmal Bone Cyst are younger than 20 years. They are primary benign active vascular lesions of multiple blood-filled cavities, locally destructive and expansile lesion. It is most commonly encountered in the metaphysis of long bones. The incidence of Aneurysmal Bone Cyst in tarsal bone is less than 12% of which calcaneum account for about 1.6% of all Aneurysmal Bone Cysts [1,2].

Thus, here we report our case of rare site of Aneurysmal Bone Cyst calcaneum in the paediatric age group treated with curettage with fibular strut graft bone graft substitute (Synthetic Calcium Hydroxyapatite crystal).

Case report

A 10 years old boy presented with a 3-month history pain and swelling in right heel, swelling and pain gradually increased for the past 1 month and had difficult in walking. He had previous history trauma and underwent 3 native bandages. On examination he was found to have bony hard swelling from the calcaneum.

X-ray and computed tomography suggestive of an expansile lytic lesion with sclerotic borders with internal septations, solitary well defined, radiolucent mass occupying 90 percent of calcaneum with narrow zone of transition, without cortical breech, without periosteal reaction and does not involving the soft tissue [Figures 1 and 2].

Figure 1: Diffuse bony swelling from calcaneum.

Figure 2: X-ray shows expansile lytic lesion of calcaneum with multiple septations.

Further preceded with CT which showed expansile lytic lesion of right calcaneum of size 4.8 x 4.4x 4 cm without matrix mineralization with multiple internal septae, no adjacent soft tissue mass.

Surgical procedure

Patient in Left lateral position, by lateral approach L-Shaped incision from base of the 5th Metatarsal to posterior aspect of lateral malleolus, Peroneal tendon retracted. Multiple drill holes made on the lateral wall of the calcaneum. Then cavity opened which is filled with multiple fibrous septae and blood. All the contents were scooped out and sent for Histopathological examination [Figures 3-7].

Figure 3: CT shows expansile lytic lesion of right calcaneum of size 4.8 x 4.4 x 4 cm without matrix mineralization with multiple internal.

Figure 4: Calcaneal cavity opened by lateral approach by preserving peroneal tendon.

Figure 5: Multiple blood-tinged osteoid tissue with fibrous tissue sent for histopathology.

Figure 6: Calcaneal defect augmented with modified hydroxyl.

Figure 7: Fluoroscopy image of fibular strut augmented with modified hydroxy apatite blocks.

The defect of the size measured 5 cm, so fibular strut graft kept within the cavity and augmented with bone graft substitutes - G Bone (synthetic calcium hydroxyapatite crystals) due to inadequate autogenous bone graft.

HPE report interpreted dense cellular fibro collagenous tissue with numerous multinucleated osteoclastic giant cells interspersed with multiple clefts like cystic spaces and some of them are filled with blood, the cyst walls are lined by giant cells. Area of edema, haemorrhage and hyalinization are also seen. occasional foci show bony spicules. Features consistent with Aneurysmal Bone Cyst [Figure 8].

Figure 8: Black arrow shows cystic spaces with haemorrhage blue arrow shows multinucleated giant cells.

Post-operative Protocol

Post-operative period was uneventful, Due to lack of soft tissue cover, Wound healing was delayed, and patient was kept on below knee cast and non-Weight bearing for 6 weeks and serial follow up X-Ray taken which shows good Graft up take and consolidation. Outcome was measured using AOFAS ankle hind foot scale.

With 1 year follow up patient had better outcome and with Graft consolidation without any disturbances in gait with full ankle range of motion and excellent AOFAS ankle hind foot scale [Figures 9-10].

Figure 9: Shows serial follow-up X-rays with good graft uptake.

Figure (10-A): Shows pain free gait.

Figure (10-B): Full ankle range of movements.

Discussion

Term Aneurysmal Bone Cyst was first used in 1942 Jaffe and Lichtenstein on Aneurysmal Bone Cyst Lesions seen on radiograph [3] The incidence of Aneurysmal Bone Cyst in tarsal bone is less than 12% of which calcaneum account for about 1.6% of all Aneurysmal Bone Cysts.

Aneurysmal Bone Cyst are locally destructive and expansile lesion and impinges the surrounding tissue causing, pain and swelling and rarely pathological fractures [2]

Cystic Lesions that affect calcaneum includes, Simple Bone Cyst, Aneurysmal Bone Cyst, Chondroblastoma, Giant Cell Tumor, Osteo Sarcoma (Telangiectatic Variety) [3]. Therefore, exact diagnosis warrants clinical, radiological and histological correlation. Being and unusual site HPE confirmation is necessary to differentiate it from other cystic lesions.

Eighty five percent of the cases of Aneurysmal Bone Cyst are under 20 of age.

60% cases originate from metaphysis, while 28% originate from the meta epiphyseal and sub chondral part [4].

Despite various modalities of treatment such as wide excision or arterial embolization, surgical curettage is sufficient to treat most cases of Aneurysmal Bone Cyst of calcaneum.

• So, our patient was treated with surgical curettage with Fibular sturt graft with bone graft substitute to fill the cavity. With 2 year follow up we have not reported any recurrence of the lesion without any infection.

Conclusion

So, any patient with heel pain and swelling should be subjected to at least radiographic imaging. The cause of heel pain of calcaneum may be any of the above-mentioned lesions. Management protocol varies from lesion to lesion.

To conclude Aneurysmal Bone Cyst of calcaneum is extremely rare, proper diagnosis and appropriate management is necessary to prevent recurrence. Surgical curettage supplemented with Fibular strut grafting with bone graft substitute (Synthetic Calcium hydroxyapatite crystals) is a valuable option in paediatric age group.

1. Babazadeh S, Broadhead ML, Schlicht SM, Powell GJ, Tymms GM (2011) Pathologic fracture of a calcaneal aneurysmal bone cyst. The Journal of foot and ankle surgery 50:727-732.

Indexed at, Google Scholar, Crossref

2. Li M. Cell type expression of RANKL in periprosthetic membrane. Virginia Commonwealth University. 2005.
3. Kransdorf MJ, Sweet DE (1995) Aneurysmal bone cyst: concept, controversy, clinical presentation, and imaging. AJR. American journal of roentgenology 164: 573-580.

Indexed at, Google Scholar, Crossref

4. Chowdhry M, Chandrasekar CR, Mohammed R, Grimer RJ (2010) Curettage of aneurysmal bone cysts of the feet. Foot & ankle international 31:131-135.

Indexed at, Google Scholar, Crossref