Biological Reconstruction for Extremity Osteosarcoma: Distraction Osteogenesis Technique

Type I: Tumor at diaphyseal location or metaphyseal location over 2 cm far from the epiphyseal plate

Type II: Tumor at metaphyseal location extending to less than half of the epiphyseal growth plate

Type III: Tumor at metaphyseal location extending to the whole growth plate

Type IV: Metaphyseal tumor extending through the growth plate into part of the epiphysis at least 1 cm from the articular surface

Type V: Tumor extending into less than half of the epiphysis less than 1 cm away from the articular surface

Type VI: Tumor extending into more than half of the epiphysis less than 1 cm away from the articular surface

Fig. 16.1

Classification of tumor excision. (a) Type I. (b) Type II. (c )Type III. (d) Type IV. (e) Type V. (f) Type VI

16.3 Surgical Techniques

16.3.1 Type I (Fig. 16.2)

Fig. 16.2

Type I: surgical method. (a) Resection line. (b) Tumor resection. (c) Application of external fixator and osteotomy for lengthening. (d) Bone grafting at docking site. (e) After bone consolidation

In Type I, the tumor is diaphyseally or metaphyseally located over 2 cm far from the epiphyseal plate. The operative technique of the DO method consists of en bloc tumor excision with preservation of the epiphyseal plate and articular surface. An external fixator is applied and osteotomy is performed for postoperative bone transport. After docking bone transport, we usually perform bone graft at the docking site. Shortening-distraction is indicated if acute shortening is possible during the operation. Optional intramedullary nailing, if feasible, or plate conversion, are also used to shorten the external fixation time [4, 6].

16.3.2 Type II (Fig. 16.3)

Fig. 16.3

Type II: surgical method. (a) Resection line. (b) Tumor resection. (c) Application of external fixator and osteotomy for lengthening. (d) Bone grafting at docking site. (e) After bone consolidation

In Type II, the tumor is located metaphyseally and extends to less than half of the epiphyseal growth plate. There is also a possibility of joint deformity due to unequal growth after reconstruction. The operative technique of the DO method consists of hemicortical en bloc tumor excision. An external fixator is applied, and proximal hemicortical osteotomy is performed for postoperative bone transport. Epiphysiodesis of the other side of the growth plate is one option to avoid future angular deformities for young patients. After docking bone transport, we usually perform a bone graft at the docking site. At that time, plate conversion is optionally used to shorten the external fixation time. If a deformity occurs in the future, correction with or without lengthening can be performed.

16.3.3 Type III (Fig. 16.4)

Fig. 16.4

Type III: surgical method. (a) Resection line. (b) Tumor resection. (c) Application of external fixator and osteotomy for lengthening. (d) Bone grafting at docking site. (e) After bone consolidation

In Type III, the tumor is metaphyseally located and extends to the whole growth plate. Limb length discrepancies are anticipated in immature patients, which may be managed surgically if necessary. The operative technique of the DO method consists of transepiphyseal and intercalary en bloc tumor excision with the growth plate. Surgical technique is basically same as in the Type I DO method.