Magnetic resonance imaging of occult fractures of the proximal femur

Abstract

The evaluation of the painful hip in the elderly osteoporotic patient with normal plain radiographs can be difficult. We studied 15 osteopenic patients with normal plain radiographs and suspected hip fractures with magnetic resonance (MR) imaging and found MR to be an excellent aid in detecting occult fractures. A clear fracture was seen in 10 of the 15 patients, who then underwent surgical repair based on the MR study. The remaining patients had no MR-demonstrable fracture and were successfully treated nonoperatively. Some believe that a negative bone scan in this population of patients should be repeated within 3 days prior to a definitive "no fracture" decision being made. Unfortunately, bone scanning lacks spatial resolution, and increased osteoblastic activity may be caused by other pathologic processes besides fracture. Two of the 15 patients had MR-demonstrated bone infarcts near the fracture. One patient also had femoral head osteonecrosis on the side of the fracture. One patient with metastatic prostatic carcinoma had a hip fracture and one patient with metastatic breast carcinoma had no fracture. No only is MR imaging an excellent technique for delineating occult fractures, but due to its spatial resolution, associated bone disorders adjacent to fractures can be detected in most instances. From a cost perspective, rapid diagnosis and early treatment of an occult femoral fracture is advisable. A reduced hospital stay pending diagnosis and the early institution of definitive therapy also decrease the chance that a simple non-displaced fracture will displace and require more complex management with resultant increased morbidity and cost.(ABSTRACT TRUNCATED AT 250 WORDS)

Imaging Choices in Occult Hip Fracture

“…Other factors that may weaken bone include smoking, inactivity, rheumatoid arthritis, post-gastrectomy syndrome, a low percentage of body fat, poor calcium intake, excessive alcohol intake, and endocrine disorders such as diabetes, hyperthyroidism, hyperparathyroidism, and hypercortisolemia (24). Alcoholism as a factor in osteoporosis was seen in a 45-year-old-patient found to have occult hip fracture in Haramati et al's study (28).…”

Diagnosis of acute fractures of the extremities: comparison of low-field MRI and conventional radiography

“…This approach has been reported by several authors elsewhere [4,12,15,18,20,22,24]. The study design allowed, to the best of our knowledge, for the first time a calculation of the interobserver variability (two radiologists for both methods) and an ROC analysis.…”

“…High-field MRI as well as low-field MRI systems have shown their diagnostic potential for the detection of musculoskeletal disorders and radiographically oc- Sensitivity, specificity, and accuracy were calculated as the mean of the results of both readers cult fractures [1,2,5,12,13,14,15,16,17,18,19,20,21]. The combination of STIR and T1-weighted sequences seems to allow a satisfactory evaluation of osseous lesions along with low-field MRI [9,22,23,24,25].…”

Bilateral occult hip fracture

“…25 Meanwhile, another study reported a 4.2% incidence, which was derived by dividing the number of occult operative hip fractures found by the total number of patients with operative hip fractures diagnosed during their study period. 26 Although magnetic resonance imaging (MRI) is universally recognized as the gold standard for diagnosing the occult hip fracture, 13,27 with sensitivity and specificity approaching 100%, 20,[28][29][30][31] earlier studies used either clinical progression or bone scanning for diagnosis. 19,[22][23][24] Bone scanning, or bone scintigraphy, has a reported sensitivity and specificity of 93% and 95%, respectively 32 ; however, it is thought to take 24 to 72 hours for a scan to become positive in older patients.…”