Sacral Insufficiency Fractures: Recognition and Treatment in Patients with Concurrent Lumbar Vertebral Compression Fractures

Abstract

IntroductionIn reviewing a larger group of osteoporotic vertebral compression fractures (VCFs), we found that the overall incidence of sacral insufficiency fractures (SIFs) is higher than commonly reported values. This is especially seen in patients with previous or concurrent lumbar VCFs and also in a subgroup that had lumbar stenosis or hip arthroplasty. The altered biomechanics due to associated lumbar stenosis or hip arthroplasty lead to increased mechanical stress on already weakened and deficient sacral alae, which are more vulnerable to osteoporotic weakening than other parts of the sacrum.Materials & methodsWe studied an overall population of patients with VCF seen clinically and separated the patients into the following groups: patients not previously treated, patients treated with vertebroplasty or kyphoplasty at one or more levels, and patients diagnosed with sacral fractures and treated with vertebroplasty or kyphoplasty. We wanted to see if a pattern existed among the patients who had sacral symptoms, were diagnosed with sacral insufficiency fractures, and subsequently underwent sacroplasty.ResultsIn a review of 79 consecutive patients, over a 24-month period, with VCF who underwent surgical treatment, there were 10 patients who also had sacral insufficiency fractures. Four of the patients had sacral insufficiency fractures without VCF. None of the patients with sacral insufficiency fractures were on treatment for osteoporosis at the time of diagnosis. The following symptoms indicated SIF: lower sacral pain (n = 10), buttock pain (n = 7), lateral hip pain (n = 5), and groin pain radiating to the thigh (n = 4). The average time to diagnose SIF was two months after the onset of pain.ConclusionsSacral insufficiency fractures are a frequent cause of both acute and chronic pain; however, they are often missed by the majority of physicians. The frequency of undetected sacral fractures is high. This is due to a number of potential pitfalls, which include both subjective and objective reasons: the patient presenting with vague symptoms, the physician only performing a physical examination of the lumbar spine, and the physician ordering the inadequate standard lumbosacral radiographs, computed tomography (CT), or magnetic resonance imaging (MRI), as well as automatically relating the pain and other symptoms to preexisting MRI findings that are very commonly found in the elderly population. All of these pitfalls lead to SIFs being overlooked.

Balloon-assisted sacroplasty as a successful procedure for osteoporotic sacral insufficiency fractures after failure of the conservative treatment

“…Sacral insufficency fractures are commonly underdiagnosed because of unspecific symptoms who are similar to lumbar spine stenosis or (pathological) lumbar spine body fractures. Besides, sacral insufficency fractures are concomitant pathologies in osteoporotic lumbar spine body fractures and therefore overseen when finding the latter 1 . Clinical symptoms are unspecific being caudal lumbar or gluteal pain, rarely sciatica or a neurological deficit 2 , 3 .…”

“…Typically, a second look on imiginary findings in patients with persistent pain are the key to finding the right diagnosis 2 . The average time span between onset of symptoms to diagnosis is several weeks to months 1 . Explanations herefore are various.…”

Radiologic Evaluation of Chronic Vertebral Compression Fractures and Role of Vertebral Augmentation

“…Thoracic fractures are most frequent but complaints of pain noted in the upper lumbar and lower thoracic spine may indicate a thoracic or thoracic-lumbar VCF, and fractures in this area can lead to a more flexed position (kyphosis) on examination [ 8 - 9 ]. Sacral fractures are frequently missed because of the vagueness of the pain, and they can also present with indirect symptoms, such as pain in the hip and groin, rather than in the low lumbar spine and sacrum [ 10 - 11 ]. Since VCFs occur in an older population, these same patients often have concurrent lumbar degenerative osteoarthritis, spondylolisthesis, and stenosis, so care needs to be taken in reviewing symptoms as well as radiologic studies for lumbar pain after a minor fall or accident [ 12 ].…”

“…In a second group, comprising seven patients, the diagnosis of VCF was delayed because initial attention was focused on another area of the spine or the fracture area was not visualized: two of the four were at the thoracic-lumbar junction and in another two, the original plain X-rays were poor-quality films of obese patients, which did not visualize the fracture The third group consisted of three patients where the initial attention was the lumbar spine and the thoracic-lumbar and thoracic spine films were not obtained until the patient complained of persistent pain in these areas after undergoing therapy for the lumbar spine with a diagnosis of degenerative discs and spondylosis being made after falls or auto accidents. In these cases, the degenerative pathology was initially treated and the VCF was not diagnosed immediately until the persistence of pain or recognition that the pain was in another spinal area, like the lower thoracic spine compared to the lumbar spine, led to the discovery of the fracture on new imaging studies [ 11 - 12 ] (Figure 5 ).…”

Vertebral Compression Fractures after Lumbar Instrumentation

“…However, patients undergoing longer multilevel instrumentation clearly had a higher frequency of fractures [ 9 , 12 ]. Patients can also develop either a unilateral or bilateral sacral insufficiency fracture if the lower lumbosacral area is not included in the original fusion with instrumentation [ 13 - 14 ]. Osteoporotic fractures have also been reported within the instrumented construct as well as the pedicle where screws were placed.…”