External fixation reconstruction of the residual problems of benign bone tumours

Abstract

The mechanical features of and biologic response to using distraction osteogenesis with the circular external fixator are the unique aspects of Ilizarov's contribution that allows deformity correction and reconstruction of bone defects. We present a retrospective study of 20 patients who suffered from a variety of benign tumours for which external fixators (EF) were used to treat deformity, bone loss, and limb-length discrepancy. A total of 26 bony segments in twenty patients (10 males, 10 females; mean age 17 years; range 7-58 years) were treated with EF for residual problems from the tumour itself (primary treatment) in 8 patients and for complications related to the primary surgery (secondary treatment) in 12 patients. Histological diagnoses were Ollier's disease (n = 4), Fibrous Dysplasia (n = 5), Congenital multiple exostosis (n = 5), giant cell tumour (n = 2) and one case for chondromyxoid fibroma, desmoid fibroma, chondroma and unicameral bone cyst. Various types of external fixators used to treat these problems. These were Ilizarov, unilateral fixator, multiaxial correction frame (Biomet, Parsippany, NJ), Taylor spatial frame (Memphis, TN) and smart correction multiaxial frame. The mean follow-up time was 69.5 months (range 35-108 months). The mean external fixation time was 159.5 days (range 27-300 days). The mean external fixation index was 67.4 days/cm (12-610) in 26 limbs who underwent distraction osteogenesis. The mean length of distraction was 4.9 cm (range 0.2-14 cm). At final follow-up, all patients had returned to normal activities. Complications were in the form of knee arthrodesis in one patient, pin tract infection in six and residual shortening in eight patients. The use of EF and the principles of distraction osteogenesis, in the management of problems associated with benign bone tumours and related surgery yields successful results especially in young patients. With this approach, the risk for recurrence of shortening and deformity may be minimized with overcorrection or over-lengthening as dictated by preoperative planning.

Keywords: Benign bone tumours; Bone deformity; Distraction osteogenesis; External fixation; Limb reconstruction; Shortening.

Fig. 1

An eight-year-old girl with Ollier’s disease Lt. femur and tibia who developed valgus deformity and shortening following initial surgery of excision. Preoperative orthoroentgenogram denoting the LLD and the valgus deformity

Fig. 2

Tibial Ilizarov with proximal osteotomy for gradual lengthening and distal osteotomy for gradual correction of valgus

Fig. 3

Clinical photo of the Ilizarov frame

Fig. 4

Femoral unilateral fixator for acute deformity correction and gradual lengthening, note the consolidation of the regenerates with corrected deformity

Fig. 5

After removal of the fixators, restored length with deformity correction

Fig. 6

A thirteen-year-old boy with Fibrous dysplasia Lt. distal femur treated initially by excision. Clinically, block test denoting 5 cm shortening

Fig. 7

AP orthoroentgenogram, denoting valgus deformity with the CORA at the site of previous initial treatment

Fig. 8

Lateral X-ray of the same patient

Fig. 9

Immediately after the operation, with Smart correction multiaxial frame and distal femoral osteotomy

Fig. 10

After correction and lengthening with good regenerate (note the amount of translation as the osteotomy site is not at the CORA)

Fig. 11

Orthoroentgenogram after removal of the frame with healed regenerate and fully corrected limb

Fig. 12

Clinically straight limb with the block test denoting residual shortening

Fig. 13

A fourteen-year-old boy with Congenital Multiple Exostosis Rt. Ulna treated initially by excision. X-ray showing type 1 deformity in which there is ulnar deviation of the hand and deformity of the radius

Fig. 14

Acutely corrected radius by plate and screws. Also unilateral fixator in the ulna for gradual lengthening

Fig. 15

X-ray at the end of lengthening

Fig. 16

X-ray after removal of the external fixator, fully corrected deformity with excellent regenerate (note the 0.5 over-lengthening to avoid complications of recurrence and to improve the function

Fig. 17

Photographic documentation during external fixation period

Fig. 18

a, b Photographic documentation denoting fully corrected deformity and functional limb