Indian Journal of Plastic Surgery Medknow Publications on behalf of Indian Journal of Plastic Surgery ISSN: 0970-0358 EISSN: 1998-376x Vol. 44, Num. 1, 2011, pp. 150-156

Indian Journal of Plastic Surgery, Vol. 44, No. 1, January-April, 2011, pp. 150-156

Case Report

Salvage of foot with extensive giant cell tumour with transfer of vascularised fibular bone graft

Jose Tharayil, Rahul K Patil

Department of Plastic and Reconstructive Surgery, Lakeshore Hospital, Cochin, India

Correspondence Address:
Jose Tharayil
Department of Plastic and Reconstructive Surgery, Lakeshore Hospital, Cochin - 682040
India
joseitharayil@gmail.com

DOI: 10.4103/0970-0358.81469

Abstract

Keywords: Free fibula; giant cell tumour of foot; salvage of foot

Introduction

Common sites for giant cell tumour are the distal femur and proximal tibia followed by distal radius. Mid-foot involvement is rare and simultaneous involvement of multiple mid-foot bones is extremely so. ^[1] It is known to be locally aggressive, with frequent local recurrence after excision. Curettage, bone grafting, irradiation and en bloc resection have been used in the treatment of giant cell tumours. When en bloc resection is indicated for lesions, because of advanced invasion, removing a wide margin through normal tissue planes (often leading to amputation of the involved part) will ensure the lowest rate of recurrence.

There are very few cases reported in the literature where multiple foot bones were involved. ^[1] For this site, curettage and bone grafting is the recommended treatment of choice, although, logically, for reconstruction of large segmental bony defects, after en bloc resection, a free vascularised bone graft may prove to be an excellent surgical alternative. We report a case with extensive involvement of all the tarsal bones and metatarsal bases in a young adult. We were able to save his foot after a wide local excision and reconstruction with free fibula graft. There is no reported case in the literature stating successful salvage of a functional extremity following such an extensive giant cell tumour of the mid-foot.

Case Report

In January 2007, a 19-year-old boy presented with history of swelling over the dorsum of his right foot. The swelling had appeared 7 months back for which he consulted a local orthopaedic surgeon. Following a radiograph, the swelling was biopsied and diagnosed as a giant cell tumour. With this diagnosis, curettage of the lesion and bone grafting was performed. The swelling subsided completely just to reappear 4 months later. He was then advised a below-knee amputation of the ipsilateral leg.

The recurred lesion was a single diffuse swelling of 7 cm x 6 cm in size over the antero-medial aspect of the right mid-foot with a well-healed surgical scar over the centre of the swelling [Figure - 1]a. There was no distal neurovascular deficit. After complete physical examination, radiographs and magnetic resonance (MR) imaging scan of the leg and foot were obtained. A fresh biopsy taken from the lateral aspect of the foot [Figure - 1]b confirmed tumour recurrence. The radiograph of the foot showed confluent involvement of all tarsal bones and metatarsal bases [Figure - 1]c. MR scan of the foot confirmed the skeletal involvement [Figure - 2]a and b; and ruled out any soft tissue involvement.

The patient was explained regarding the high possibility of recurrence and possible malignant transformation. He was also explained about the difficulties in the reconstruction if it was to be attempted, like loss of contour, loss of ankle, inter-tarsal and tarso-metatarsal joint functions and possible difficulties in walking. As the patient was reluctant to accept an amputation, we decided to perform a wide local excision and reconstruction with double-barreled free fibula. As the posterior half of the calcaneum was spared, the excision was planned as shown in [Figure - 3]a. [Figure - 3]b and c show the procedure till the removal of the tumour, preserving all the tendons, neurovascular structures and the skin through the medial and lateral incisions. After adequate surgical clearance, vascularised fibula (24 cm) was harvested from the opposite leg and was doubled up on its periosteal blood supply. The fibular struts were placed between the remnant of the calcaneum and the shafts of the first and third metatarsals, and stabilised by K-wires to maintain the length of the foot [Figure - 3]d and e. The foot was stabilised in a neutral position using an external fixator frame [Figure - 3]e. No attempt was made to fix the fibular struts to the tibia. The fibula was revascularised by anastomosing the peroneal vessels (recipient) to the anterior tibial vessels (donor).

The postoperative period was uneventful and the patient was discharged on the 10th postoperative day. He was advised bed rest for 6 weeks following which the external fixator frame was removed and the leg was put in a Plaster of Paris cast. Nonweight-bearing walking was allowed from the 3rd week onwards. The donor site healed primarily. X-rays were taken on the 2 ^nd postoperative day to check alignment and, subsequently, every month for the first 6 months to look for bony union, followed by 3-monthly for the next 6 months to look for continued union and remodelling. At 4 months, the fractures healed uneventfully and the wires were removed [Figure - 4]a. Gradual weight bearing was then started, which was supervised by the hospital physiotherapist. In spite of repeated warnings to discourage immediate full-weight bearing, the patient attempted premature full-weight bearing at his residence, which resulted in fracture of the grafted fibular strut [Figure - 4]b. After radiographic evaluation, he was advised nonweight-bearing ambulation. The fracture eventually healed in another 2 months time with a hypertrophic callus [Figure - 4]c, but the remodelling continued for over a year and half forming a good weight-bearing platform [Figure - 4]d and e. Although bone scan was not performed postoperatively, the fact that the bone graft united with the adjacent bones, i.e. 1st and 3rd metatarsals and remnant of calcaneum within 4 months, confirmed the vascularisation of the fibula graft.

Three and half years after the reconstruction [Figure - 5]a and b, the patient is disease free and ambulatory with near-normal gait. He has normal sensation over the plantar and dorsal aspects of the foot. The ankle joint has 20 degrees of dorsiflexion and 10 degrees of plantar flexion. There is a flexion deformity at the metatarsophallangeal joints of all toes, and complete dorsiflexion of toes is not possible. This may be due to lax extensors that have shown no tendency to spontaneous adjustment in length or tension over the period of time. This can be easily corrected by adjusting the tension of extrinsic extensors of the toes but the patient is satisfied with the reconstruction and has refused the option of undergoing another surgery. According to Enneking′s functional scoring system [Table - 1] used for evaluation outcome following excision of extremity neoplasm, this patient scored 25/30 points. The patient has slight limp while walking. He does not have a high stepping gait neither does he sway to either side while walking.

Discussion

Giant cell tumour is a locally aggressive tumour. The treatment of this tumour is essentially surgical, as malignant transformation has been reported in the literature following radiotherapy. ^[2] Traditionally, curettage with or without bone grafting is the first line of management. Although usually effective, it has been associated with a very high (15-60%) recurrence rate. Most often, recurrence has been reported within 3 years of primary surgery, and is thought to be a persistent disease, rather than recurrence. Although some of the lesions classified as stage 1 of Enneking′s surgical staging or grade 1 of Campanacci′s radiographic grading will recur, curettage may be indicated in those cases because of the lower recurrence rate than in those classified as stage 2 or 3. However, for stage 2 or 3, grade 2 or 3 as per the above classifications or postcurettage recurrent lesions, a wide local excision with a 2.5-cm margin is indicated. ^[3] Secondly, due to a small but definite risk of malignant transformation, they should be regularly followed-up.

In the case of the resultant large bony defect, there is a wide range of bone and soft tissue reconstructive options, including conventional bone grafting. However, when nonvascularised bone is grafted to a large bony defect, the time required for bone union is significantly extended, especially if the graft is more than 7 cm long. For defects, ranging from 7.5 cm to 12 cm, Enneking et al.^[3] documented a union rate of 67%, with a stress fracture rate of 17%, at an average of 22 months postoperatively. For defects exceeding 12 cm, the results seem much less predictable. Although a union rate of 68% occurred, 30% of the patients required a secondary procedure to achieve this result. Furthermore, a stress fracture rate of 58% during an average postoperative period of 21 months occurred. Complications of long segmental nonvascularised bone grafts include nonunion, resorption, collapse of the articular segments and fracture of the graft. For success, these procedures require a robust and healthy soft tissue envelope. The foot lacks muscle and soft tissue bulk and may not provide adequate vascularity to the underlying graft. Also, the foot, unlike other sites, has to bear weight primarily and is more prone to stress fractures.

There are a few reports about giant cell tumour of foot in the literature. Curettage and bone grafting has been favoured in all. ^[1] In the English language literature, we could find only three separate case reports of patients where multiple tarsal bones were involved in giant cell tumour. ^[1],[4],[5] There are few reports of reconstructions of metatarsal bones with the use of free vascularised fibular grafts following a tumour resection, One of these cases reported excision of five tarsal bones and replacement with nonvascularised iliac bone graft with 7 years of follow-up. ^[1]

Autogenous vascularised bone graft for long bone reconstruction after tumour resection was first described by Taylor et al.^[6] It was subsequently popularised by McKee ^[7] and Ueba. ^[8] Free fibula subsequently has become more popular in limb sparing after long bone tumour resection.

The available treatment options in this case were amputation of foot, for which the patient was unwilling. After oncologically sound surgical clearance, the available options for reconstruction were nonvascularised or vascularised bone graft. The length of the defect, thin soft tissue covers and eventual weight-bearing function ruled out the option of nonvascularised bone graft.

Depending on the size and location of the tumour in the foot, wide surgical margins had to be planned. There are nine foot compartments described ^[9],[10] in foot for compartmental excision of tumour, but these are not applicable probably for multi-centric tumours. Therefore, limb salvage for tumours of the foot is difficult to achieve and requires detailed preoperative assessment to determine the extent of the tumour. In this case, after careful assessment of the scans to rule out soft tissue involvement on table, frozen section biopsy was performed to demonstrate clear margins and complete extra-compartmental excision.

The fundamental goal of treatment was improved quality of life by including a functional and durable reconstruction of the musculoskeletal defect. ^[11],[12] Compartmental excision in this case fortunately could be achieved without loss of functionality because of the preservation of substantial neurovascular and tendinous structures as well as skin. Intact sensation, especially on the plantar surface, is vital for foot function and skin integrity. ^[13] Our patient had intact neurovascular structures and has normal sensation over his foot. We feel that it was a great advantage and has lead the way to early functionality.

The first ray is a critical structure in the formation of the tripod of the foot enabling normal gait. ^[14],[16] During the stance and toe-off phases of the gait cycle, load bearing focuses on the first ray. ^[15] A total force of about 119% of body weight acts on the first metatarsal head, making it the most heavily loaded ray of the forefoot. ^[16] Because of the importance of the first ray for weight bearing and propulsion, one strut was attached distally to the first metacarpal and another one to the third metacarpal. The bony contact was good and the fractures united uneventfully in 4 months, and the wires were removed. Because of early complete weight bearing, both the struts got fractured but, with minimal rest, these fractures united without any intervention because of the vascularised nature of the graft. Also, after the fracture of the graft, massive amounts of callus were observed on X-ray with remodelling of bone that was found hypertrophied to almost three-times the original size, again indicating good vascularity. The young age of the patient also helped.

After 3.5 years of follow-up, the patient is disease free, the donor and recipient sites have settled well and the patient has residual flexion contracture of toes. The patient limps slightly while walking. He does not have a high stepping gait probably because of restricted motion at the ankle, which prevents full plantar flexion of the ankle joint.

Summary

We have attempted this reconstruction for salvage of foot extensively involved in giant cell tumour by using a double barrel vascularised fibula. We feel that this method deserves consideration as a last attempt to salvage the functional foot in a disease like this, with an understanding that amputation of the affected limb is the only remaining option in case of any unforeseen complications.

References

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