Low Back and Buttock Pain After a Fall

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Distinguishing fracture type to provide optimal treatment

A 51-year-old man presented to our spine clinic for investigation of low back and buttock pain accompanied by swelling and ecchymosis over the sacral prominence. He related a history of falling several feet after slipping off an icy footbridge, striking his low back and buttocks on a large tree trunk. He was on vacation at the time, and he did not seek care until he returned home.

Upon his return, he consulted his family practice provider. An initial X-ray was obtained and was read as normal. Follow-up magnetic resonance imaging (MRI) revealed a fracture through the sacrum at the S4-S5 junction. The patient was subsequently referred to our practice for specialty consult and continuing care.

The Patient

On initial presentation, the patient complained of pain from the lower back to the top of the natal crease. He described it as most severe over the bony sacral prominence. He reported a pain score of 8/10 on the Visual Analog Scale (VAS).  He reported no lower extremity pain, numbness or weakness and no history of bowel or bladder dysfunction. He stated that he was able to initiate and maintain an erection, and that he had experienced no change in his sexual function.

Physical examination revealed mild swelling over the right sacral prominence at the level of S4, accompanied by ecchymosis. The patient reported moderate tenderness on palpation of the area; fluctuance was noted, but no crepitus was elicited. A thorough neuromuscular examination of the lumbosacral spine and pelvis, including a digital rectal exam, revealed no deficits.

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Figure 1

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Figure 2

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Figure 3

The initial plain X-ray was not available for review during the evaluation. The MRI sequence was available and was personally reviewed while the patient was in the office. The MRI revealed a nondisplaced transverse fracture at the level of the S4-S5 junction (Figure 1). Coronal and sagittal short T1 inversion recovery (STIR) imaging highlighted the fracture and showed its extension through the S5 foramina bilaterally (Figures 2 and 3). MRI evidence of edema at the fracture site confirmed that the fracture was acute.

The terminal spinal canal was of normal diameter, and the sacral foramina remained widely patent at all levels. A moderate subcutaneous hematoma was visualized superficial to the fracture. Although accompanying pelvic or lumbar fractures are common, in this case the patient had an isolated transverse sacral fracture. The level of the fracture and the lack of displacement indicated that the fracture was likely stable.

Discussion

Transverse sacral fracture is a rare clinical entity, often missed on plain film radiography and clinical evaluation. Commonly this fracture occurs in the setting of multiple severe traumatic injuries and is overshadowed by the presence of more threatening injuries. Lewis et al popularized the term “jumper’s syndrome” in 1965, referring to the pattern of spinal, pelvic and lower extremity injuries associated with falls from height.1 Roy-Camille et al coined the term “suicide jumper’s fracture” for transverse sacral fracture in 1985.2 Although sacral fractures are rare, isolated fractures (without corresponding pelvic ring fractures) are even more rare, representing only 5% to 10% of all sacral injuries. 3,4 Most sacral fractures are vertical, however isolated sacral fractures tend to be transverse.4

Denis et al proposed a systematic classification system for sacral fractures in 1988.5 The Denis classification systems utilizes a simple zone approach and provides prediction of expected neurologic consequences and treatment strategies. Zone I fractures involve the ala alone, sparing the foraminal and central canals. Zone II fractures involve one or more sacral foramina. Zone III fractures involve primarily the central canal (Figure 4).

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NovCF_Figure5_300xTransverse sacral fractures can, and commonly do, involve more than one zone. Transverse fractures are often described based on their radiographic appearance. Description is based on the fracture appearance compared to letters in the English or Latin alphabets. Common fracture patterns include H, U, ? (lambda) and t (tau) (Figure 5).2

Transverse sacral fracture types are not adequately described using the Denis classification alone. Additional subclassification of these fractures is based upon the amount and type of displacement along with the configuration of the fracture lines. Type I fractures show angulation without significant subluxation. Type II fractures show angulation and subluxation. Type III fractures feature complete subluxation. Type IV fractures result in compression and comminution of the first sacral segment (Figure 6).2,6

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Clinical Presentation

Presentation common to all transverse sacral fractures is localized pain at the fracture site. Swelling and/or ecchymosis are often present. Additional symptomatology correlates closely to the sacral level of the fracture, as well as the zone or zones involved. 3 High sacral fractures (S1-2 or S2-3) are most often associated with neurogenic bowel and bladder symptoms. Lower fractures (S3-4 or S4-5) are more likely to cause neurogenic bowel symptoms while sparing the bladder. Displacement of fracture fragments correlates highly with the likelihood of neurologic damage and poorer long-term outcomes regardless of management. 4,5

Robles reported that 97% of transverse spine fracture patients present with some type of neurologic injury. 7The Denis classification correlates closely with the likelihood and severity of neurologic injury. Gibbons et al reported a 24% incidence of neurologic injury in patients presenting with zone I fractures, 29% in zone II fractures and 57% to 60% in zone III fractures.8 Zone I and II injuries usually result in unilateral lumbar or sacral radiculopathy. Zone III injuries are generally more severe, with bilateral involvement and accompanying bowel and/or bladder dysfunction.5,8

Concurrent injuries and medical interventions in the acute care phase can mask important examination findings. Urinary catheterization can mask voiding issues. Spine and lower extremity fractures can obscure examination clues that indicate sacral nerve root compression. Carefully elicited history from the patient, responders and witnesses, paired with a high degree of suspicion, are keys to detecting sacral fracture. Determination of fall height and point of impact (i.e., landing on feet or direct sacral impact) are particularly important, since this data correlates closely with the risk of pelvic or sacral fracture.9

Imaging

Plain film radiography of the pelvis and sacrum is indicated for all patients presenting with fall from height as a mechanism of injury, but negative finding on plain films is not definitive.6,9 A literature review by Kim et al revealed that only 5% of sacral fractures were identified on admission in 195 patients without accompanying neurologic deficit. In patients with neurologic deficit, only 49% were initially identified as having sacral fractures.4 Roy-Camille et al noted that 54% of sacral fractures went unrecognized initially, resulting in treatment delay of 1 to 18 months.2 In light of these reports, I propose that MRI or CT of the pelvis and sacrum should be the standard in fall patients.

Treatment

There is little controversy over the management of displaced fractures, and in these cases surgical decompression and stabilization is recommended.2,3-6,10  Immediate emergency referral for surgical management of these injuries is necessary to limit the risk of permanent neurologic sequelae.

Treatment of low transverse fractures without displacement is also straightforward, consisting of conservative management combined with careful follow-up. Hak et al suggest progressive weight bearing as tolerated, with an orthosis and initial toe touch weight bearing on the affected side for 8 weeks.10 This regimen is most useful in vertically oriented sacral fractures and high transverse fractures in which pelvic ring forces are more likely to cause additional fracture stress.

For low transverse sacral fractures, personal experience indicates that progressive weight bearing without orthosis is well tolerated. Because this type of fracture is below the level of the sacroiliac joint, toe touch weight bearing is not necessary, and patients tolerate ambulation well. Reclining rather than sitting provides increased comfort at rest, and patients may need bolsters or other methods of pressure shifting to sit, recline or lie down.

Treatment of high sacral fractures and minimally displaced fractures with neurologic deficit remains controversial. Kim et al suggest that all high transverse fractures be considered for stabilization. H type fractures are especially concerning, since the pattern of fracture causes the sacral fragment to effectively float free of the pelvic ring.4 Some authors contend that decompression is the treatment of choice when fracture is accompanied by neurologic deficit.2,3,5 Others suggest conservative management in the majority of these cases, due to lack of statistical data demonstrating the superiority of surgical decompression in returning neurologic function.3,4,10,11 These cases always warrant immediate referral to a specialist surgeon with experience in treating these types of fractures.

Patient Outcome

Based on the examination, imaging studies, the level of the fracture, and in consultation with the attending orthopedic surgeon, conservative treatment was implemented for this patient.  He was placed on strict activity restriction, and worsening precautions were discussed in detail. The neuromuscular exam remained normal throughout the 12-week follow-up period. Four weeks after initial evaluation, the patient reported that pain had decreased to 4/10 on the VAS. At 12 weeks, the patient reported a 3/10 on the VAS.

A computed tomography (CT) scan of the pelvis performed 12 weeks post injury revealed excellent healing of the fracture. The patient was subsequently returned to regular activity, including return to his usual occupation.


References:

  1. Lewis WS, et al. Jumpers Syndrome. The trauma of high free fall as seen at Harlem Hospital. J Trauma.1965;5(6):812-818.
  2. Roy-Camille R, et al. Transverse fracture of the upper sacrum. Suicide jumper’s fracture. Spine.1985;10(9):838-845.
  3. Sapkas GS, et al. Transverse sacral fractures with anterior displacement. Eur Spine J. 2008;17(3):342-347.
  4. Kim MY, et al. Transverse sacral fractures: case series and literature review. Can J Surg. 2001;44(5):359-363.
  5. Denis F, et al. Sacral fractures: an important problem. Retrospective analysis of 236 cases. Clin Orthop Relat Res. 1988;227:67-81.
  6. Strange-Vognsen HH, Lebech A. An unusual type of fracture in the upper sacrum. J Orthop Trauma.1991;5(2):200-203.
  7. Robles LA. Transverse sacral fractures. Spine J. 2009;9(1):60-69.
  8. Gibbons KJ, et al. Neurological injury and patterns of sacral fractures. J Neurosurg. 1990;72(6):889-893.
    Dayner J. Always Obtain Radiographs of the Lumbar Spine, Pelvis and Calcaneus in Jumper Syndrome. Emergency Medicine News. 2001;23(7):23-24.
  9. Hak DJ, et al. Sacral Fractures: current strategies in diagnosis and management. Orthopedics.2009;32(10). doi: 10.3928/01477447-20090818-18.
  10. Phelan ST, et al. Conservative management of transverse fractures of the sacrum with neurological features. A report of four cases J Bone Joint Surg. 1991;73-B:969-971.
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About Author

J. Bradley Davis, MPAS, PA-C

J. Bradley Davis is a physician assistant at Intermountain Spine Institute in Salt Lake City.

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