Insufficiency and stress fractures of the long bones occurring in patients with rheumatoid arthritis and other inflammatory diseases, with a contribution on the possibilities of computed tomography

Delayed Diagnosis of a Tibial Stress Fracture Associated with Glucocorticoid and Methotrexate Therapy in a Patient with Rheumatoid Arthritis: A Case Report

The risk of stress fractures is associated with rheumatoid arthritis (RA), which can aggravate bone loss. We report the case of a patient who was on long-term medication for RA presenting with lower extremity pain on the left and swelling without trauma. Magnetic resonance imaging and plain radiographs at the previous hospital showed no signs of fracture, but radiographs performed later, revealed a stress fracture of the left distal tibia. The stress fracture may have occurred due to multiple reasons such as long-term use of methotrexate and glucocorticoids, active RA, postmenopausal state, and immobility. Suspicion of a stress fracture should not be ruled out especially in RA patients with persistent pain, even if the radiographical findings are normal. Additional imaging and follow-ups are essential. The patient’s pain was relieved with Korean medicine treatments, which suggests their potential application for stress fractures in RA patients.

Clinical features of methotrexate osteopathy in rheumatic musculoskeletal disease: A systematic review

BACKGROUND

There is growing evidence from case reports that methotrexate (MTX) therapy may impair bone metabolism in individual patients leading to low bone mass, atraumatic stress fractures and immobilizing bone pain - referred to as 'MTX osteopathy'. However, the clinical features, risk factors and treatment options of this condition are still elusive.

METHODS

A systematic review was conducted according to PRISMA guidelines. Two databases (MEDLINE, Embase) were searched for published cases of MTX osteopathy in patients with rheumatic musculoskeletal diseases (RMD). Data from the included publications were extracted and descriptive statistical analysis was performed.

RESULTS

We report data from 32 studies describing 80 adult RMD patients with stress fractures in MTX osteopathy. Most cases were found in elderly women with longstanding RMD, especially rheumatoid arthritis (72.5%). MTX osteopathy commonly presented as stress fracture of the distal tibia (51.3%), calcaneus (35.0%) and proximal tibia (27.5%), mimicking arthritis in some cases. Although a majority of the patients met the densitometric criteria for osteoporosis (58.1%), typical osteoporotic fractures (e.g., vertebral fractures) were rarely seen. Patients frequently suffered from bilateral (55.0%), multiple (71.3%) and recurrent fractures (25.0%). Fractures mainly occurred at low to moderate doses of MTX therapy (45.0%). It should be noted that half (48.8%) of the patients did not receive systemic steroid therapy for at least 3 years.

CONCLUSIONS

Low-dose MTX therapy in RMD may result in atraumatic stress fractures of the lower extremity that can mimic arthritis. MTX osteopathy is characterized by a pathognomonic type of stress fractures with band- or meander-shaped appearance along the growth plate.

Tibia stress injury and the imaging appearance of stress fracture in juvenile dermatomyositis: six patients' experiences

BACKGROUND

Tibial stress injuries are frequent injuries of the lower extremity and the most common causes of exercise-induced leg pain among athletes and military recruits. They sometimes occur in patients with pathological conditions of bone metabolism such as osteoporosis or rheumatoid arthritis, but there are previously no cases reported in juvenile dermatomyositis (JDM). Here we report 6 JDM patients who presented with shin pain, and the imaging appearance of tibial stress fractures or stress reactions.

CASE PRESENTATION

All 6 patients with JDM presented with shin pain or tenderness in the anterior tibia without any evidence of excessive exercise or traumatic episode. They were diagnosed with tibial stress injuries based on a combination of radiographs, three-phase bone scans, and magnetic resonance imaging (MRI), and 5 out of 6 patients had been treated with prednisone and/or methotrexate at onset of tibial stress injuries. In one patient, we could not find any abnormalities in his radiograph, but the subsequent MRI showed tibial stress reaction. In all 6 patients, the tibial stress injuries improved with only rest and/or analgesics.

CONCLUSION

We experienced 6 children with JDM who presented with shin pain, and who were diagnosed with tibial stress fractures or stress reactions. Their underlying disease and weakness, treatment with glucocorticoid and methotrexate, or inactivity may have resulted in these tibial injuries, and made these patients more predisposed than other children. In addition to preventing JDM patients from getting osteoporosis, we need to consider stress reactions when children with JDM complain of sudden shin pain.

Clinical and Radiological Characterization of Patients with Immobilizing and Progressive Stress Fractures in Methotrexate Osteopathy

Methotrexate (MTX) is one of the most commonly prescribed drugs for autoimmune rheumatic diseases. As there is no consensus on its negative effects on bone, the purpose of this investigation was to determine the clinical spectrum of patients with stress fractures due to long-term MTX treatment (i.e., MTX osteopathy). We have retrospectively analyzed data from 34 patients with MTX treatment, severe lower extremity pain and immobilization. MRI scans, bone turnover markers, bone mineral density (DXA) and bone microarchitecture (HR-pQCT) were evaluated. Stress fractures were also imaged with cone beam CT. While the time between clinical onset and diagnosis was prolonged (17.4 ± 8.6 months), the stress fractures had a pathognomonic appearance (i.e., band-/meander-shaped, along the growth plate) and were diagnosed in the distal tibia (53%), the calcaneus (53%), around the knee (62%) and at multiple sites (68%). Skeletal deterioration was expressed by osteoporosis (62%) along with dissociation of low bone formation and increased bone resorption. MTX treatment was discontinued in 27/34 patients, and a combined denosumab-teriparatide treatment initiated. Ten patients re-evaluated at follow-up (2.6 ± 1.5 years) had improved clinically in terms of successful remobilization. Taken together, our findings provide the first in-depth skeletal characterization of patients with pathognomonic stress fractures after long-term MTX treatment.

Subchondral insufficiency fractures and spontaneous osteonecrosis of the knee may not be related to osteoporosis

The term insufficiency fracture implies inadequate bone and is applied to some subchondral knee magnetic resonance images. We reviewed bone mineral density, body mass index, meniscal extrusion, comorbidities, and demographics in 32 knee insufficiency fracture patients. Only five were osteoporotic. Meniscal extrusion was predominant.

PURPOSE

The literature supports systemic osteoporosis as a risk fracture for spontaneous osteonecrosis of the knee (SONK). SONK is also called a subchondral insufficiency fracture. Recognizing that insufficiency fracture and SONK are related, we designed this retrospective study to determine if knee subchondral insufficiency fractures were associated with osteoporosis based on bone mineral density.

METHODS

Based on magnetic resonance imaging findings, 32 patients were diagnosed as having an insufficiency fracture by an orthopaedic surgeon with magnetic resonance imaging confirmation by a musculoskeletal radiologist. We reviewed body mass index, age, sex, comorbidities, demographics, and bone mineral density using both T-scores and Z-scores.

RESULTS

The average age was 70, and only five patients were osteoporotic. Twenty-six of the 32 patients were female. The average age-related Z-score was 1 standard deviation above normal.

CONCLUSIONS

We conclude that osteoporosis is not the underlying cause of this disorder in the majority of patients.

Reproducibility of a peripheral quantitative computed tomography scan protocol to measure the material properties of the second metatarsal

Background

Peripheral quantitative computed tomography (pQCT) is an established technology that allows for the measurement of the material properties of bone. Alterations to bone architecture are associated with an increased risk of fracture. Further pQCT research is necessary to identify regions of interest that are prone to fracture risk in people with chronic diseases. The second metatarsal is a common site for the development of insufficiency fractures, and as such the aim of this study was to assess the reproducibility of a novel scanning protocol of the second metatarsal using pQCT.

Methods

Eleven embalmed cadaveric leg specimens were scanned six times; three times with and without repositioning. Each foot was positioned on a custom-designed acrylic foot plate to permit unimpeded scans of the region of interest. Sixty-six scans were obtained at 15% (distal) and 50% (mid shaft) of the second metatarsal. Voxel size and scan speed were reduced to 0.40 mm and 25 mm.sec^-1. The reference line was positioned at the most distal portion of the 2^nd metatarsal. Repeated measurements of six key variables related to bone properties were subject to reproducibility testing. Data were log transformed and reproducibility of scans were assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV%).

Results

Reproducibility of the measurements without repositioning were estimated as: trabecular area (ICC 0.95; CV% 2.4), trabecular density (ICC 0.98; CV% 3.0), Strength Strain Index (SSI) - distal (ICC 0.99; CV% 5.6), cortical area (ICC 1.0; CV% 1.5), cortical density (ICC 0.99; CV% 0.1), SSI – mid shaft (ICC 1.0; CV% 2.4). Reproducibility of the measurements after repositioning were estimated as: trabecular area (ICC 0.96; CV% 2.4), trabecular density (ICC 0.98; CV% 2.8), SSI - distal (ICC 1.0; CV% 3.5), cortical area (ICC 0.99; CV%2.4), cortical density (ICC 0.98; CV% 0.8), SSI – mid shaft (ICC 0.99; CV% 3.2).

Conclusions

The scanning protocol generated excellent reproducibility for key bone properties measured at the distal and mid-shaft regions of the 2^nd metatarsal. This protocol extends the capabilities of pQCT to evaluate bone quality in people who may be at an increased risk of metatarsal insufficiency fractures.

An unusual cause of apareunia

A 49-year-old woman with history of rheumatoid arthritis presented with worsening pelvic pain. A pelvic computed tomography (CT) scan demonstrated a fracture and a lytic expansile lesion within the right superior and inferior pubic rami. The diagnosis of "insufficiency fractures secondary to rheumatoid arthritis" was established. Six months later, she started describing pain and fullness sensation in the vagina which eventually led to a complete apareunia. An x ray confirmed healing of the previous fractures, fracture of both left superior and inferior pubic rami, and an upwards shift of the right hemi-pelvis. Conservative management was chosen. Twelve months later, no improvement occurred and she was still apareunic. A "corrective osteotomy surgery" was performed and the displaced pubic rami and ischial tuberosities were remodelled bilaterally through a vertical incision over each labia majora. These bones were partially excised until an adequate vaginal opening was established. Her symptoms have impressively resolved with complete reverse of the apareunia.

Methoden der Bildgebung und der Knochendichtemessung bei der Osteoporose im Rahmen entzündlich-rheumatischer Erkrankungen

Besides clinical history and clinical findings conventional X-ray is important in the evaluation of osteoporosis as the third diagnostic tool. Its purpose is mainly excluding other diseases and proof of fractures as well as their follow up. Also X-ray is able to demonstrate complications of osteoporosis such as insuffiency fractures and effects of therapy as for example fluorosis. For very early diagnosis bone densitometry is used. Today the improved methods deliver fracture prediction percentages of high value. As a planar measurement method DXA of the spine and of the femoral neck can be used. Volumetric tools, which can measure trabecular bone, without overlying cortical bone, are computed tomography of the spine and of the distal radius. Quantitative ultrasound is an interesting approach, but which does not really measure bone densitometry and which is net yet suited for clinical follow up. Quantitative Magnetic Resonance is far from routine clinical application.

16 detector multislice CT versus skeletal scintigraphy in the diagnosis of wrist fractures: value of quantification of 99Tcm-MDP uptake

To compare the measured uptake of 99Tcm-methylene diphosphonate (99Tcm-MDP) in those scaphoid fractures seen on both 16 detector multislice CT and scintigraphy, with those seen only on scintigraphy. Over a 12 month period a total of 51 patients with suspected fracture underwent both conventional 99Tcm-MDP scintigraphy and 16 detector multislice CT on the same day. The 99Tcm-MDP uptake was then quantified in patients with identified fracture. This was measured by placing a region of interest (ROI) over the fracture site and the mean and maximum number of counts were compared with those in a similar size ROI placed over background bone activity. A total of 23 fractures were identified on scintigraphy of which 16 were also detected on CT (concordant). In seven cases the fracture was not seen on CT, even in retrospect (discordant). In the discordant cases, follow-up radiographs and MRI (where available) also failed to demonstrate a fracture. The mean fracture count to background bone activity ratio averaged 7.7 (range 3.2-18.5) for concordant fractures and 3.8 (range 1.7-5.3) for discordant fractures (t-test p=0.04). The maximum fracture count to background bone activity ratio averaged 12.7 (range 4.3-27.7) for concordant fractures and 6.3 (range 2.6-9.5) for discordant fractures (t-test p=0.03). It is speculated whether these discordant fractures with less 99Tcm-MDP uptake may represent a less severe injury such as bone bruise.

Distinction of Long Bone Stress Fractures from Pathologic Fractures on Cross-Sectional Imaging: How Successful Are We?

OBJECTIVE

The objectives of our study were to define CT and MRI features that distinguish pathologic fractures from stress fractures and to compare the performance of CT and MRI with radiography.

MATERIALS AND METHODS

Two reviewers retrospectively reviewed 45 MR images, 37 CT scans, and 43 radiographs in 59 patients (30 biopsy-proven pathologic fractures and 29 stress fractures followed to resolution). The features observed on MRI were abnormal bone marrow (well-defined, ill-defined); intracortical, periosteal, or muscle T1 or T2 signal; endosteal scalloping; and a soft-tissue mass. The features seen on CT were marrow abnormality and character (well-defined, ill-defined, permeative, moth-eaten), endosteal scalloping, periosteal reaction (benign, aggressive), and a soft-tissue mass. Reviewers rated their confidence for diagnosing a pathologic fracture on a 1-3 scale (< 50%, 50-95%, > 95% sure, respectively) with each technique. Performance of each technique was defined by reviewer accuracy and area under the receiver operating characteristic curve (Az); the frequency with which the MRI and CT features were associated with pathologic and stress fractures was calculated.

RESULTS

For both reviewers, accuracy for differentiating pathologic from stress fractures was highest on MRI (accuracy/Az: reviewer 1, 98%/0.97; reviewer 2, 93%/0.99); CT (reviewer 1, 88%/0.83; reviewer 2, 82%/0.90) was less accurate than radiography (reviewer 1, 94%/0.98; reviewer 2, 88%/0.96). On MRI, pathologic fractures compared with stress fractures exhibited well-defined T1 marrow signal (83% vs 7%, respectively; p < 0.001), endosteal scalloping (58% vs 0%, p < 0.001), muscle signal (83% vs 48%, p = 0.026), and a soft-tissue mass (67% vs 0%, p < 0.001). On CT, pathologic fractures compared with stress fractures exhibited marrow abnormality (84% vs 17%, respectively; p = 0.001), endosteal scalloping (44% vs 0%, p = 0.006), and aggressive periosteal reaction (36% vs 0%, p = 0.04).

CONCLUSION

MRI is useful for distinguishing pathologic from stress fractures, especially after inconclusive radiographic findings. Specifically, pathologic fractures exhibit well-defined T1 marrow alterations, endosteal scalloping, and adjacent soft-tissue abnormalities.

Distinguishing stress fractures from pathologic fractures: a multimodality approach

Whereas stress fractures occur in normal or metabolically weakened bones, pathologic fractures occur at the site of a bone tumor. Unfortunately, stress fractures may share imaging features with pathologic fractures on plain radiography, and therefore other modalities are commonly utilized to distinguish these entities. Additional cross-sectional imaging with CT or MRI as well as scintigraphy and PET scanning is often performed for further evaluation. For the detailed assessment of a fracture site, CT offers a high-resolution view of the bone cortex and periosteum which aids the diagnosis of a pathologic fracture. The character of underlying bone marrow patterns of destruction can also be ascertained along with evidence of a soft tissue mass. MRI, however, is a more sensitive technique for the detection of underlying bone marrow lesions at a fracture site. In addition, the surrounding soft tissues, including possible involvement of adjacent muscle, can be well evaluated with MRI. While bone scintigraphy and FDG-PET are not specific, they offer a whole-body screen for metastases in the case of a suspected malignant pathologic fracture. In this review, we present select examples of fractures that underscore imaging features that help distinguish stress fractures from pathologic fractures, since accurate differentiation of these entities is paramount.

Stress fractures of the ankle and forefoot in patients with inflammatory arthritides

Twenty-four stress fractures occurring in the metatarsal bones and ankle region were examined in 17 patients with inflammatory arthritides. There were 16 metatarsal, four distal fibular, two distal tibial, and two calcaneus fractures. Radiographic analyses were performed to determine the presence of possible predisposing factors for stress fractures. Metatarsal and ankle region stress fractures were analyzed separately. Stress fractures occurred most frequently in the second and third metatarsals. In metatarsal fractures, there was a trend for varus alignment of the ankle to cause fractures of the lateral metatarsal bones and valgus alignment of the medial metatarsal bones. Valgus deformity of the ankle was present in patients with distal fibular fractures in the ankle region group. Calcaneus fractures showed neutral ankle alignment. Malalignment of the ankle and hindfoot is often present in distal tibial, fibular, and metatarsal stress fractures. Additionally, patients tend to have long disease histories with diverse medication, reconstructive surgery and osteoporosis. If such patients experience sudden pain, tenderness, or swelling in the ankle region, stress fractures should be suspected and necessary examinations performed.