Multiple contiguous spinous process fractures, a case report and literature review.

Contiguous spinous process fractures are an extremely rare event with only a few cases described in the literature. They are usually stable lesions treated with analgesic medication, immobilization, physical activity restriction for 4 to 6 weeks and close surveillance. These fractures appear to have a significant risk of nonunion, despite the good reported results. We report a case of a 61 years-old male patient who suffered eight contiguous spinous process fractures following a tractor accident.

Introduction

Clay-shovelers' fracture, an isolated spinous process fracture of the cervical or thoracic vertebrae, is an uncommon condition that was first reported in the early 20th century [1], [2], [3]. However, the occurrence of several contiguous spinous process fractures is even rarer, with only a few reported cases in the literature (Table 1). It typically occurs in the lower cervical or upper thoracic spine. In these cases, deceleration and shear forces caused by trapezius, rhomboids, and the ligamentum nuchae contraction probably exert repetitive traction on their attachment sites to the spinous processes, resulting in several fractures. There are also reports of spinous process fractures in osteoporotic bones and in renal transplanted patients on steroids [4].

Table 1

Literature review of patients with contiguous spinous process fractures.

Author	Year of publication	Age/sex	Level of involvement (number)	Etiology	Treatment
Kose KC [8].	2006	58/M	T5-T10 (6)	Automobile accident	Hyperextension brace for 3 months
Solaroğlu et al. [3]	2007	32/M	C6, C7 (2)	Automobile accident	Cervical collar for 4 weeks
Unay et al. [4]	2008	39/M	C7, T1 (2)	Osteoporosis	Cervical collar for 6 weeks
Kang and Lee [5]	2009	40/M	T1, T2 (2)	Golf player	Immobilization for 8 weeks
Akhaddar et al. [9]	2011	40/not known	T2-T8 (7)	Automobile accident	Immobilization for 6 weeks
Umredkar et al. [10]	2011	–	C6, T4 (6)	Automobile accident	Cervical collar for 4 weeks
Kim et al. [6]	2012	45/F	C6, C7 (2)	Golf player	Cervical collar for 6 weeks
Akhaddar and Mandour [11]	2013	29/F	C6-T9 (11)	Automobile accident	Immobilization for 6 weeks
Han and Sohn [12]	2014	34/M	C4-T8 (12)	Motorcycle accident	Cervical collar and thoraco-lumbar brace for 4 weeks
Upadhyaya et al. [7]	2016	45/M	C7-T6 (7)	Automobile accident	Cervical collar and thoracic brace for 8 weeks
Present case report	2020	61/M	T5-T12 (8)	Tractor fall	Thoraco-lumbar brace for 6 weeks

We present a case of multiple spinous process fractures in the thoracic spine, with an extension from T5 to T12. To the best of our knowledge, there are only ten cases of contiguous spinous process fractures described in the literature (Table 1) and this study presents itself as the largest bibliographic review on the subject. In this way, it is possible to draw objective conclusions about the clinical presentation, treatment and natural evolution of these fractures.

Case report

A 61 years-old male patient was admitted at the emergency department after falling from a tractor with direct back trauma. At presentation the patient had moderate pain complaints, with mild edema in the dorsal region and pain on spinous processes palpation, without irradiation. On neurological examination, there were no perceptible deficits, with preserved mobility and strength of the upper and lower limbs and no bladder or bowel dysfunction.

Computed tomography (CT) revealed a complex fracture pattern, with minor compression fractures of T7, T8, T12 and L2 vertebral bodies and 8 contiguous spinous process fractures in the thoracic spine, with an extension from T5 to T12 (Fig. 1).

Fig. 1

Left - Computerized tomography (CT) revealing eight contiguous spinous process fractures, from T5 to T12. Right - After 14 months, all the levels, with the exception of D12, have evolved to nonunion.

The patient was kept under observation in the emergency department for 24 h and was discharged home with a prescription for a nonsteroidal anti-inflammatory drug (NSAID) analgesic, and a Jewett brace for 6 weeks. He gradually recovered with nonoperative management and, after 24 months of follow up, the patient did not have any functional limitation in his daily life activities and presented pain improvement from 7/10 to 1/10 according to the Visual Analogue Score (VAS). Effectively, the majority of the spinous process fractures have evolved to nonunion, which had no influence on the clinical improvement of the patient.

Discussion

Isolated spinous process fractures are most commonly described at T1 level, followed by C7, T2, T3, and C6, with 16 % of these injuries involving more than one spinous process [2], [3]. The mechanisms of injury can be due to direct trauma to the posterior aspect of the spine but also because of repetitive muscle and ligament stresses due to shoveling by manual laborers. Although shovel load was previously common, these injuries are now rare due to agricultural machineries. Nowadays, falls and road traffic accidents are the most likely causes of these fractures. Recently they have also been reported in relation to sports practice (e.g. volleyball and golf) (Table 1) [5]. These lesions seem to be more common in male patients, namely between the ages of 38 and 61 years-old (Table 1). Even though clay-shovelers' fractures are stable, dynamic radiographies (flexion and extension views) can be performed to search for associated instability [6], [7], especially in situations associated with cervical fractures. Computed tomography (CT) of the cervical and thoracic spine may be useful to better characterize the spine fracture as well as possible surrounding associated injuries [5]. Magnetic resonance imaging (MRI) can provide additional important findings, including the existence of posterior paraspinal muscular injury (edema), disruption of the supraspinous and/or interspinous ligaments, bone marrow edema, extensive prevertebral edema and fluid (hemorrhage) [7].

These injuries are usually stable although associated with significant pain complaints. It is imperative to combine analgesic medication, immobilization and close surveillance of these patients' pain evolution. NSAID exposure is known as a potential risk factor for developing a delayed union or nonunion, so has increasing age. In this case report, the patient only consumed NSAIDs for the first 3 days after the trauma, and subsequently required only paracetamol medication for pain relief.

In conclusion, contiguous spinous process fractures are very rare lesions resulting from direct trauma or repetitive muscle and ligament traction on the spinous processes. This type of lesion is treated conservatively without the need for surgical intervention [5]. Immobilization and physical activity restriction for 4 to 6 weeks generally leads to good outcomes [5]. Frequent non-consolidation of spinous processes with subsequent evolution to nonunion has been reported, despite the absence of significant correlation with clinical outcomes, as in this case report [8].

Sources of financial support that require acknowledgment

None.

Approval code issued by the institutional review board (IRB)

This study is only a retrospective description of a clinical case and a narrative review, it does not present any type of change in conduct or follow-up. Therefore, approval by the IRB or ethics committee is not required.

Statement of informed consent

The patient was informed that data concerning the case would be submitted for publication and agreed with the creation and publication of this article.

Declaration of competing interest

The authors declare that there are no conflicts of interest.