Complications of the Technique and Solutions

Abstract

Limb salvage in children with bone tumors consists in a long surgical intervention divided in two-steps. The first step is to resect the tumor; the second step is to reconstruct the limb. In appropriate cases, Cañadell’s technique has been demonstrated to be a safe and effective technique that facilitates resection of the tumor whilst providing a safe margin. Reconstruction after the use of Cañadell’s technique has similar rates of complications as reconstructions after other surgical procedures.

With distraction of the growth plate at a rate of 1 mm per day, the physis usually breaks through the layer of degenerative cells. This chapter will focus on an unusual complication of the Cañadell technique: rupture in the wrong site. The solution should this occur is intra-epiphyseal osteotomy, which can be undertaken without sacrificing the articulation.

11.1 Introduction

Bone sarcoma surgery consists of two steps: resection and reconstruction San-Julian et al. [5]. Complications in the reconstruction step are the same as with reconstruction after other surgical procedures or pathological conditions, such as, fractures, pseudoarthrosis, and infections. For more information see Chap. 12: “Clinical Results”.

As a tumor resection technique, epiphysiolysis before excision has, over time, proved to be a safe and effective technique. It has, however, had critics, who have expressed concern about the possibility of higher rates of complications (infection, for example) that might result from placing an external fixator so close to the tumor. Another concern has been the possibility that tumor cells might be left in the joint area. These considerations have been cautiously investigated over the years and the security and efficacy of the technique has been established (Cañadell and San Julian 2009) [2]. There is no increased risk of local recurrence or infection as a result of the use of an external fixator before resection (Xu et al. 2014) [6]. In this chapter we take a look at a different complication of the Cañadell technique: distraction through an unexpected plane.

When distraction is through the physis at a rate of 1 mm/day, the break usually occurs through the calcified layer in the metaphyseal zone of the growing plate (de Pablos 1986) [1]. This is the desired site of rupture. On some occasions (about 2–3 % of cases), however, the break occurs in a different place. In this chapter we analyze this unusual scenario, and explain how to detect it and what to do in response.

11.2 Material and Methods

We have reviewed our series of more than 160 cases during the last 30 years.

11.3 Results

In our series, there were only two cases of complications related to epiphysiolysis before excision, and both of these cases were distraction in an unexpected site: through the tumor. Our colleagues in Switzerland have reported a third case of such distraction (Betz et al. 2012) [1].

There were no complications related to the external fixator, which was in position for only 10–12 days. The infection rate was 9 %/low, comparable to that for the cases in which epiphysiolysis was not used

11.3.1 Case 1

Case 1 was a 10-year-old boy who presented with pain in his left knee and a limp, which had been ongoing for 2 months. Initially, the patient attended a hospital other than ours. An X-ray was taken and a cortical defect observed (Fig. 11.1).

Fig. 11.1

XR and MRI of a 10 y-o male who complains of knee pain. Bone alteration is seen on the XR. MRI shows no affectation of the physis. So limb salvage is the indication in this cases

Suspecting a bone tumor, an MRI scan was taken. Subsequently, the boy underwent open biopsy (of 6 cm of length) with curettage. After this procedure the patient was not able to walk with that leg due to the pain. The tumor was diagnosed as osteosarcoma.

At this point, the boy was brought to our center to receive treatment. After evaluation of the case (Fig. 11.2), we decided that limb salvage was possible by means of the Cañadell technique and posterior reconstruction. The patient started chemotherapy and received three sessions of intra-arterial chemotherapy. We placed the external fixator and distraction was carried out at a rate of 1 mm per day.

Fig. 11.2

XR and MRI after open biopsy elsewhere. The tumor has grown without the treatment

After between 7 and 10 days of distraction or if the patient reports pain, we typically request an X-ray to confirm rupture through the growth plate. In this case, the X-ray revealed that separation had occurred through the biopsy tract (Fig. 11.3).

Fig. 11.3

Control XR of the external Fixator. We observed that the distraction has not been done through the physis, is been done through the biopsy tract. At this point we remove the EF

The external fixation was removed and intra-epiphyseal osteotomy undertaken. We were able to preserve the proximal tibiae epiphysis and the knee joint. We reconstructed with an intercalary allograft with an intramedullary nail (Fig. 11.4 and 11.5).

Fig. 11.4

Specimen. We performed an intra-epiphyseal osteotomy. See how we get a secure margin above the physis. Histology showed complete necrosis of the tumor

Fig. 11.5

Postoperative RX of the reconstruction with allograft and intramedullary nail and scaffolding with a plate fixing the rest of the epyphisis. We conserve the articular surface

Postoperatively, the patient recovered in a normal way. He continued with chemotherapy treatment. The excised tumor had 100 % necrosis. The patient started walking with crutches and then with full weight-bearing and demonstrated complete range of motion of the knee.

Nine months after completion of chemotherapy (one and a half years after surgery) the patient reported a pain in the contralateral knee (Fig. 11.6). This turned out to be a single bone metastasis without lung affectation. We decided to treat the metastasis as if it were a primary tumor. Intra-venous and intra-arterial chemotherapy was initiated. As the tumor was in contact with all of the physis, we performed intra-epiphyseal osteotomy rather than the Cañadell technique. Then we proceeded with reconstruction (Fig. 11.7)

Fig. 11.6

Xr and MRI of the right tibiae. The patient presented a bone metastasis in contact with the whole physis without lung mets. We decided to do an intra-epiphyseal osteotomy as he has before in the other leg

Fig. 11.7

XR control of both legs

The tumor was 90 % necrotic. The patient continued to receive chemotherapy, but 3 months later developed lung metastases and further bone metastases. He died 4 months later.

11.3.2 Case 2

This concerns a 9 year-old boy who presented with pain and a limp, without any trauma, in his right leg. At that time, the symptoms had persisted for 4 months. He was taken to hospital (not initially our hospital) because of an increase in the intensity of pain and the fact that pain continued even during the night (Fig. 11.8a). By means of closed biopsy, the diagnosis of osteosarcoma was established. There was no lung metastasis. He started chemotherapy, and with two courses of intravenous chemotherapy there was a clear decrease in the pain. His referral center proposed amputation as surgical treatment, and it was in search of other possibilities that he came to our hospital.

Fig. 11.8

(a) 9 yo boy who complains of knee pain. A simple XR showed a cortical bone defect and soft tissue mass. Diagnosed of osteosarcoma. (b) XR post chemotherapy. We observed how the tumor has not grown and is delimitate. (c) T1 and T2 sequences of the tumor which is in contact to 50 % of the physis

After evaluation of the case (Fig. 11.8b, c), we decided that limb salvage was achievable by means of epiphysiolysis (Fig. 11.9) before excision (Cañadell’s technique). We gave just one session of intra-arterial chemotherapy before placing the external fixation, because, as mentioned above, he had already started neoadjuvant chemotherapy elsewhere, with an apparently good response.

Fig. 11.9

We decided to do limb salvage with epiphysiolysis. We place the external fixation

During the preoperative planning session, we saw the possibility that the distraction had not occurred in the expected place, and that the rupture was through the tumor; a CT scan confirmed our suspicion (Fig. 11.10).

Fig. 11.10

CT were we observe the Fracture line

To save the articulation we performed intra-epiphyseal osteotomy. As the growth plate is not tibial plateau, for surgeons with less experience in intra-epiphyseal osteotomy we recommend the use of a k-wire under fluoroscopy control to be more accurate with the saw when performing the osteotomy (Fig. 11.11). In the case of this patient, we had to sacrifice the patellar tendon insertion. For reconstruction we used a humerus intercalary allograft, as this was the most suitable for this patient. Because we had not been able to preserve the growth plate, we used a slightly larger allograft in order to compensate for future dissymmetry (Fig. 11.12).

Fig. 11.11

(1) K-wire helps us to do the osteotomy, (2) Removal of the tumor, (3) Reconstruction with allograft with intramedullary nail and plate

Fig. 11.12

Postop XR

The tumor was 99 % necrotic. The patient continued with standard chemotherapy and follow up. He had complete articular range of motion and walked without crutches. He had slightly instability in varus-valgus angulation of the knee. After 3 years the patient developed lung metastasis. He underwent thoracotomy of the left lung and then, 4 months later, video-thoracoscopy of the right lung. One year later he developed bone metastasis. Currently, 4 years after the initial surgery, the patient is alive but with disease that is still under treatment with chemotherapy and radiotherapy.

11.4 Discussion

The two complications that we have observed with epiphysiolysis were by no means catastrophic and had an easy work-around.

The two cases described are surprising in that we would not expect metastatic disease when the rates of necrosis of the tumor in response to chemotherapy were so high (99 % and 100 %). In this sense these two cases are exceptional.

Both patients had complete range of motion of the knee, could walk, and returned to their normal way of life. In view of the short follow-up, we were not able to evaluate residual dissymmetry due to loss of the growth plate.

11.5 Conclusions

Epiphysiolysis before excision has been shown to be a safe technique (Eralp and Enar 2013) [4] (Zhang et al. 2014) [7]. Distraction at an unexpected site occurred in only 2–3 % of cases. Should this happen, treatment can proceed with intra-epiphyseal osteotomy, and so there is still a chance to preserve the joint, without increasing the local recurrence rate. In case of doubt about the location of the distraction, we recommend taking a CT scan.