Langenbecks Arch Chir (1997) 382: 25–28

© Springer-Verlag 1997

O R I G I N A L A RT I C L E

F. Schweighofer · H. P. Hofer · R. Wildburger N. Stockenhuber · G. Bratschitsch

Unstable fractures of the upper thoracic spine

Received: 8 May 1996

Instabile Frakturen der oberen Brustwirbelsäule Zusammenfassung Instabile Frakturen der oberen Brustwirbelsäule sind wegen der hohen Inzidenz an Begleitverletzungen und Rückenmarkläsionen eine therapeutische Herausforderung. Diese Kasuistik konzentriert sich auf die operative Therapie solcher Verletzungen. Wir präsentieren 9 Patienten mit instabilen Verletzungen der oberen Brustwirbelsäule, nach der Einteilung von Magerl et al. handelt es sich um 7 Typ C- und 2 Typ B-Verletzungen. 8 Patienten hatten komplette Querschnittsläsionen, bei 1 Patient bestand eine unauffällige neurologische Situation. Alle Patienten wiesen Begleitverletzungen auf, 9 hatten Rippenfrakturen, 3 ein frakturiertes Sternum und 3 einen schweren Hämatothorax. Alle wurden operiert; 6 alleinige dorsale Fusionen, 2 alleinige ventrale Fusionen nach Thorakotomien wegen stark blutender rupturierter Interkostalarterien und eine kombinierte Fusion nach fehlgeschlagener posteriorer Stabilisierung wurden ausgeführt. Die Behandlung solcher Patienten sollte individuell gestaltet werden, abhängig von den Begleitverletzungen, vom Blutverlust aufgrund von frakturierten Rippen und rupturierten Gefäßen und vom Schmerz, verursacht durch einen instabilen Thorax. Im allgemeinen bevorzugen wir den dorsalen Zugang bei instabilen Verletzungen der Brustwirbelsäule. Schlüsselwörter Obere Brustwirbelsäule · Instabile Frakturen · Stabilisierung Abstract Unstable fractures of the upper thoracic spine are a therapeutic challenge because of the high rate of associated injuries and frequent occurrence of spinal cord le-

F. Schweighofer (½) · H. P. Hofer · R. Wildburger · N. Stockenhuber · G. Bratschitsch Department of Traumatology, University of Graz, Auenbruggerplatz 7a, A-8036 Graz, Austria

sions. This study focuses on the operative treatment of these injuries. We present nine patients with unstable injuries of the upper thoracic spine. According to the classification of Magerl et al., there are seven type C and two type B fractures. Eight patients had complete transverse lesions of the cord and one had no evidence of spinal cord injury. All patients presented associated injuries: nine patients had fractured ribs, three a fractured sternum and three a severe haemothorax. All underwent operative treatment: six posterior fusions only, two anterior interbody fusions only after thoractotomy owing to severe bleeding from ruptured intercostal arteries, and one a combined fusion after failure of posterior fusion. The treatment of these patients should be individualized, depending on the associated injuries, loss of blood owing to fractured spine and ruptured vessels and depending on the back pain resulting from an unstable thorax. In general, we prefer the posterior approach to unstable fractures of the upper thoracic spine. Key words Upper thoracic spine · Unstable fractures · Stabilization

Introduction

The upper thoracic spine ranges from T1 to T10. The rib cage restricts motion and adds stiffness to the spine. Thoracic kyphosis is caused by the vertical height of the vertebral bodies, which is about 2–3 mm less anteriorly than posteriorly, and so the vertebral bodies are load-bearing and the posterior arches act in resisting tension. The upper thoracic spine has the narrowest lumen of the spinal canal and the scantiest vascular supply to the spinal cord [2, 3]. These criteria increase the risk of neurological damage in unstable fractures of the upper thoracic spine. Unstable fractures are a therapeutic challenge because of the high rate of associated injuries and frequent occurrence of spinal cord lesions. The aim of this study is to emphasize the operative treatment of unstable fractures of the upper thoracic spine.

26 Fig. 1 Anteroposterior chest X-ray study shows a dislocation fracture (type C) of the upper thoracic spine (patient 3)

Patients and methods Between 1990 and 1994, nine unstable fractures of the upper thoracic spine were treated operatively in the Department of Traumatology of the University of Graz. According to the classification of thoracic and lumbar injuries, presented by Magerl et al. [8], two type B and seven type C fractures from T2 to T8 were operated on. There were seven males and one female. Their ages ranged from 17 to 60 years (average 28 years). The causes of injury were traffic accidents in seven and falling from a height in two patients. Five of the last patients underwent the methylprednisolone therapy advocated by Bracken et al. [2]. Preoperatively, plain radiographs an CT scans of the injured and adjacent vertebrae were routinely obtained in all patients. All nine patients had associated fractured ribs, three a fractured sternum and three a severe haemothorax. One patient had no neurological deficit, but the others had complete transverse lesions of the cord. The surgical procedure was carried out from 6 h to 8 days after injury. Two patients underwent an anterior transthoracic interbody fusion after thoracotomy because of severe haemothorax owing to bleeding from ruptured intercostal arteries. Seven were stabilized by a posterior approach using plates designed by Louis in six cases and Steffee plates in one case.

Table 1 Diagnoses and neurological lesions of nine patients with unstable fractures of the upper thoracic spine Number of patients

Age (years)

Classification of fracture

Level of injury

Neurological lesion

1 2 3 4 5 6 7 8 9

60 25 25 19 22 20 40 17 24

B2 C1 C3 C1 C3 C2 C1 C1 B1

T1–2 T8–9 T5–6 T6–7 T5–7 T6–7 T4–5 T6–7 T7–8

– Complete Complete Complete Complete Complete Complete Complete Complete

Fig. 2 Lateral radiograph of the thoracic spine demonstrates an anteriorly dislocated fracture of the proximal thoracic spine with shortening

In one patient, a laminectomy was additionally performed (patient 9) and four patients had a bone graft applied additionally.

27 Fig. 3 Anteroposterior and lateral X-ray studies after dorsal approach and stabilization with Louis plates

Table 2 Operative procedures, time between injury and operation, associated injuries and complications in nine patients

Number of patients

Operative procedures

Time

Associated injuries

Complications

1

Posterior fusion C7–T3

3 days

Fractured ribs, fractured sternum

–

2

Posterior fusion T6–T1

2 days

Fractured ribs

–

3

Posterior fusion T3–9

5 days

Fractured ribs, fractured sternum, severe bleeding from intercostal arteries (thoracotomy)

–

4

Posterior fusion T5–9, reoperation and anterior interbody fusion

1 day 8 days

Fractured ribs

Redislocation, pulmonary embolism

5

Anterior interbody fusion T6–8

6h

Fractured ribs, severe bleeding from intercostal arteries (thoracotomy)

–

6

Anterior interbody fusion T3–8

8h

Fractured ribs, fractured sternum, severe bleeding from intercostal arteries (thoracotomy)

–

8

Posterior fusion T5–9

2 days

Fractured ribs

–

9

Posterior fusion T5–10

12 h

Fractured ribs

–

28

Results and complications

In one patient there was a redislocation secondary to loosening of the distal screws 6 days after the operation. Reduction was achieved using larger pedicel screws, and subsequently a transthoracic interbody fusion using a titanium mesh cylinder was performed. The patient developed a pulmonary embolism 3 days after the last operation. The patients with cord lesions were transferred to a rehabilitation centre after 4–8 weeks. The follow-up ranged from 1 to 4 years. There was no change in the neurological situation. All patients with complete transverse lesions have been mobilized in wheelchairs. Three patients complain sometimes of back pain and four had metal removed.

Discussion

The upper thoracic spine is different from other parts of the spine because of its stiffness, and so the compression tolerance is increased by a factor of 4. Considerable violence is necessary to destabilize this rigid system [1, 3]. Fractures of the upper thoracic spine can be detected on chest radiographs in half of the patients [3]. In trauma patients with impaired consciousness who complain of pain in the thoracic spine, plain radiographs are mandatory. If there is any doubt of the fracture or if an operation is planned, CT scans should be performed. A classification of thoracic injuries is very helpful to obtain information regarding the severity of injury, the type of instability and the choice of the appropriate therapy. The main categories of classification presented by Magerl et al. [8] deal with three types. Type A covers compression injuries of the vertebral body. Concerning the thoracic spine, compression fractures are the most common injuries. They are caused by axial loading forces and are considered to be stable enough for functional treatment regarding the degree of traumatic kyphosis and the spinal cord injury. Type B defines destruction injuries affecting the anterior and posterior elements and type C multidirectional instabilities with translation. The degree of instability increases from type A to type C [4, 8]. In the literature there is controversial discussion regarding the treatment of injuries of the upper thoracic spine. Place et al. [9] reported about complications in patients with traumatic paraplegia and found that the surgically treated group had twice as many complications as the nonoperative group. Complications included problems in wound healing, pulmonary embolism and reoperations. In the nonoperative group, there were more patients with severe back pain [9]. The treatment of these patients should be individualized and depends on the associated injuries, blood loss and back pain resulting from an unstable thorax. Therefore, operative procedures should aim at reducing pain and decreasing the loss of blood [1, 5, 7, 10].

In type A injuries without cord lesion and kyphosis of less than 25°, we prefer functional treatment with external orthotic support. All unstable fractures, such as type B and C injuries (and type A injuries with greater than 50% loss of vertebral height or greater than 25° kyphosis), should be considered for surgical treatment. If there is no cord injury or a complete cord lesion, the patient should be operated on when their general condition is stable. Patients with an incomplete cord injury may have significant potential for neurological recovery. In this situation, early decompression and fusion result in better neurological recovery [1]. Several authors noted major intrathoracic injury in one-third of patients with thoracic spine fractures and associated paraplegia [1, 6]. To avoid redislocation after posterior fusion of very unstable type C injuries (patient 4), we recommend the use of a longer instrument with six pairs of pedicle screws to stabilize the upper thoracic spine. In general, we prefer a primary posterior approach to the upper thoracic spine for reducing and stabilizing the fracture. A correct axis of the spine and clearance of the spinal canal in all cases of cord compression should be achieved. If there is a cord transection, clearance of the spinal canal becomes unnecessary. In cases with remaining anterior stenosis with cord compression in an incomplete neurological situation, an anterior approach should be performed secondarily.

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