Imaging of stress fractures of the spine

Clinical Presentation and Outcomes of Sacral Stress Fractures in Athletes: A Case Series of 13 Patients

BACKGROUND

Sacral stress fractures are a rare cause of low back pain in athletes. Given the low incidence of these fractures, there is a scarcity of data on symptomatology, risk factors, and clinical outcomes.

HYPOTHESIS

Patients diagnosed with sacral stress fractures would be athletes presenting with low back pain.

STUDY DESIGN

Case series of 13 patients with sacral stress fractures.

LEVEL OF EVIDENCE

Level 4.

METHODS

We conducted a retrospective review of medical records to identify patients diagnosed with sacral stress fractures at a single academic institution. Fractures were diagnosed on noncontrast T2-weighted magnetic resonance imaging scans and categorized using the Bakker classification system. Subjects were administered an electronic survey that asked about (1) the onset, time course, and location of pain and other symptoms; (2) time to treatment and treatment modalities pursued; (3) sports performance and time to return to sport; and (4) risk factors for stress fractures.

RESULTS

Of 18 eligible patients, 13 (72.2%) completed the survey with mean follow-up of 49.6 months (range, 1-144 months). Mean age was 28.0 years (range, 18-52 years); 9 patients (69.2%) were female, of whom 7 (77.8%) were premenopausal. The most common fracture type was Bakker type B (8 patients; 61.5%). Most patients presented with acute lumbosacral back pain in the setting of running/jogging activities. All patients underwent nonoperative treatment for an average of 3.8 months (range, 0-8 months) and three-quarters reported pain resolution at last follow-up. Rate of return to sport was 83.3%, but most patients reported ongoing deficits in running performance.

CONCLUSION

Sacral stress fractures commonly present as acute lumbosacral back pain provoked by running sports. While the pain associated with these fractures prevents most athletes from participating in sports, nonoperative management appears to be an effective treatment modality with a high rate of return to sport.

Red flags to screen for vertebral fracture in people presenting with low back pain

BACKGROUND

Low back pain is a common presentation across different healthcare settings. Clinicians need to confidently be able to screen and identify people presenting with low back pain with a high suspicion of serious or specific pathology (e.g. vertebral fracture). Patients identified with an increased likelihood of having a serious pathology will likely require additional investigations and specific treatment. Guidelines recommend a thorough history and clinical assessment to screen for serious pathology as a cause of low back pain. However, the diagnostic accuracy of recommended red flags (e.g. older age, trauma, corticosteroid use) remains unclear, particularly those used to screen for vertebral fracture.

OBJECTIVES

To assess the diagnostic accuracy of red flags used to screen for vertebral fracture in people presenting with low back pain. Where possible, we reported results of red flags separately for different types of vertebral fracture (i.e. acute osteoporotic vertebral compression fracture, vertebral traumatic fracture, vertebral stress fracture, unspecified vertebral fracture).

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 26 July 2022.

SELECTION CRITERIA

We considered primary diagnostic studies if they compared results of history taking or physical examination (or both) findings (index test) with a reference standard test (e.g. X-ray, magnetic resonance imaging (MRI), computed tomography (CT), single-photon emission computerised tomography (SPECT)) for the identification of vertebral fracture in people presenting with low back pain. We included index tests that were presented individually or as part of a combination of tests.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data for diagnostic two-by-two tables from the publications or reconstructed them using information from relevant parameters to calculate sensitivity, specificity, and positive (+LR) and negative (-LR) likelihood ratios with 95% confidence intervals (CIs). We extracted aspects of study design, characteristics of the population, index test, reference standard, and type of vertebral fracture. Meta-analysis was not possible due to heterogeneity of studies and index tests, therefore the analysis was descriptive. We calculated sensitivity, specificity, and LRs for each test and used these as an indication of clinical usefulness. Two review authors independently conducted risk of bias and applicability assessment using the QUADAS-2 tool.

MAIN RESULTS

This review is an update of a previous Cochrane Review of red flags to screen for vertebral fracture in people with low back pain. We included 14 studies in this review, six based in primary care, five in secondary care, and three in tertiary care. Four studies reported on 'osteoporotic vertebral fractures', two studies reported on 'vertebral compression fracture', one study reported on 'osteoporotic and traumatic vertebral fracture', two studies reported on 'vertebral stress fracture', and five studies reported on 'unspecified vertebral fracture'. Risk of bias was only rated as low in one study for the domains reference standard and flow and timing. The domain patient selection had three studies and the domain index test had six studies rated at low risk of bias. Meta-analysis was not possible due to heterogeneity of the data. Results from single studies suggest only a small number of the red flags investigated may be informative. In the primary healthcare setting, results from single studies suggest 'trauma' demonstrated informative +LRs (range: 1.93 to 12.85) for 'unspecified vertebral fracture' and 'osteoporotic vertebral fracture' (+LR: 6.42, 95% CI 2.94 to 14.02). Results from single studies suggest 'older age' demonstrated informative +LRs for studies in primary care for 'unspecified vertebral fracture' (older age greater than 70 years: 11.19, 95% CI 5.33 to 23.51). Results from single studies suggest 'corticosteroid use' may be an informative red flag in primary care for 'unspecified vertebral fracture' (+LR range: 3.97, 95% CI 0.20 to 79.15 to 48.50, 95% CI 11.48 to 204.98) and 'osteoporotic vertebral fracture' (+LR: 2.46, 95% CI 1.13 to 5.34); however, diagnostic values varied and CIs were imprecise. Results from a single study suggest red flags as part of a combination of index tests such as 'older age and female gender' in primary care demonstrated informative +LRs for 'unspecified vertebral fracture' (16.17, 95% CI 4.47 to 58.43). In the secondary healthcare setting, results from a single study suggest 'trauma' demonstrated informative +LRs for 'unspecified vertebral fracture' (+LR: 2.18, 95% CI 1.86 to 2.54) and 'older age' demonstrated informative +LRs for 'osteoporotic vertebral fracture' (older age greater than 75 years: 2.51, 95% CI 1.48 to 4.27). Results from a single study suggest red flags as part of a combination of index tests such as 'older age and trauma' in secondary care demonstrated informative +LRs for 'unspecified vertebral fracture' (+LR: 4.35, 95% CI 2.92 to 6.48). Results from a single study suggest when '4 of 5 tests' were positive in secondary care, they demonstrated informative +LRs for 'osteoporotic vertebral fracture' (+LR: 9.62, 95% CI 5.88 to 15.73). In the tertiary care setting, results from a single study suggest 'presence of contusion/abrasion' was informative for 'vertebral compression fracture' (+LR: 31.09, 95% CI 18.25 to 52.96).

AUTHORS' CONCLUSIONS

The available evidence suggests that only a few red flags are potentially useful in guiding clinical decisions to further investigate people suspected to have a vertebral fracture. Most red flags were not useful as screening tools to identify vertebral fracture in people with low back pain. In primary care, 'older age' was informative for 'unspecified vertebral fracture', and 'trauma' and 'corticosteroid use' were both informative for 'unspecified vertebral fracture' and 'osteoporotic vertebral fracture'. In secondary care, 'older age' was informative for 'osteoporotic vertebral fracture' and 'trauma' was informative for 'unspecified vertebral fracture'. In tertiary care, 'presence of contusion/abrasion' was informative for 'vertebral compression fracture'. Combinations of red flags were also informative and may be more useful than individual tests alone. Unfortunately, the challenge to provide clear guidance on which red flags should be used routinely in clinical practice remains. Further research with primary studies is needed to improve and consolidate our current recommendations for screening for vertebral fractures to guide clinical care.

Insufficiency Fractures vs. Low-Energy Pelvic Ring Fractures - Epidemiological, Diagnostic and Therapeutic Characteristics of Fragility Fractures of the Pelvic Ring

BACKGROUND

Fragility fractures of the pelvis (FFP) encompass two fracture entities: fracture after low-energy trauma and insufficiency fracture without trauma. It is unclear whether the two subgroups differ in terms of diagnosis and therapy. The aim of this retrospective study was to evaluate insufficiency fractures with regard to defined parameters and to compare specific parameters with the fractures after low-energy trauma.

PATIENTS AND METHODS

In the period from 2008 to 2017, 203 patients with FFP were recorded at our clinic (Level 1 Trauma Centre DGU, SAV approval). Of these, 25 had an insufficiency fracture and 178 had a pelvic ring fracture after low-energy trauma. Epidemiological, diagnostic and therapeutic parameters were examined.

RESULTS

There was a relative increase in the insufficiency fracture within the FFP (2008 - 2009: 5.0% vs. 2015 - 2017: 17.8%). In these patients, osteoporosis tended to be more pronounced than in patients after low-energy trauma (t-value: - 3.66 vs. - 3.13). The diagnosis of insufficiency fractures showed increased use of MRI and DECT (60.9% vs. 26.0%) and a high proportion of type IV fractures after FFP (40.0% vs. 7.9%). In terms of therapy, surgical treatment of the insufficiency fracture was sought more often (68,2% vs. 52,1%), with a tendency towards increased use of combined osteosynthesis procedures (14.3% vs. 7.6%).

CONCLUSION

We were able to show that as the number of cases increases, the insufficiency fracture becomes more important within FFP. If these patients tend to have more pronounced osteoporosis, particular attention should be paid to the diagnosis and adequate therapy of the osteoporosis, especially in the case of an insufficiency fracture. In addition to the increased diagnostic testing using MRI and DECT to detect oedema and the increased surgical therapy for this type of fracture, it is also noteworthy that the insufficiency fracture can cause higher-grade fractures after FFP.

Axial Spondyloarthritis: Mimics and Pitfalls of Imaging Assessment

Axial spondyloarthritis (axSpA) is a chronic inflammatory disorder that predominantly involves the axial skeleton. Imaging findings of axSpA can be divided into active changes, which include bone marrow edema, synovitis, enthesitis, capsulitis, and intra-articular effusion, and structural changes, which include erosions, sclerosis, bone fatty infiltration, fat deposition in an erosion cavity, and bone bridging or ankylosis. The ability to distinguish between imaging lesions suggestive of axSpA and artifacts or lesions suggestive of other disorders is critical for the accurate diagnosis of axSpA. Diagnosis may be challenging, particularly in early-stage disease and magnetic resonance imaging (MRI) plays a key role in the detection of subtle or inflammatory changes. MRI also allows the detection of structural changes in the subchondral bone marrow that are not visible on conventional radiography and is of prognostic and monitoring value. However, bone structural changes are more accurately depicted using computed tomography. Conventional radiography, on the other hand, has limitations, but it is easily accessible and may provide insight on gross changes as well as rule out other pathological features of the axial skeleton. This review outlines the imaging evaluation of axSpA with a focus on imaging mimics and potential pitfalls when assessing the axial skeleton.

Association of osteoporosis and varus inclination of the tibial plateau in postmenopausal women with advanced osteoarthritis of the knee

Background

Although varus inclination of the tibial plateau has increasingly been recognized as a major risk factor in the progression of Osteoarthritis of the knee (OA knee), little attention has been placed on the development of the varus inclination of the tibial plateau. Osteoporosis is a disease characterized by low bone mass and may increase the risk of a stress fracture in the proximal tibia. To date, risk factors for varus inclination of the tibial plateau are rarely reported. In this study, we investigated Bone Mineral Density (BMD) as a risk factor of varus inclination of the tibial plateau in postmenopausal women with advanced OA knee.

Methods

A total of 90 postmenopausal women with varus OA knee who had received a total knee arthroplasty in our department between January 2016 and December 2019 were reviewed. Certain factors may correlate to inclination of the tibial plateau (Medial Tibial Plateau Angle, MTPA), including age, operation side, Kellgren-Lawrence grade of OA knee, BMD, Body Mass Index (BMI), Lateral Distal Femur Angle (LDFA), lower extremity alignment (Hip-Knee-Ankle angle, HKAA), and history of both spinal compression fracture and hip fracture were collected and analyzed.

Results

Osteoporosis, lower extremity varus malalignment and age were significantly associated with varus inclination of the tibial plateau (MTPA) (P = 0.15, 0.013 and 0.033 respectively). For patients with a lower extremity varus malalignment (HKAA < 175°), osteoporosis (T-score ≤ -2.5) was significantly associated with inclination of the tibial plateau. For patients with a normal lower extremity alignment (HKAA ≥ 175°), no significant association was found between osteoporosis (T-score ≤ -2.5) and varus inclination of the tibial plateau.

Conclusions

Osteoporosis, lower extremity varus malalignment and age are major risk factors for inclination of the tibial plateau in postmenopausal women with OA knee. More attention needs to be given to the progression of varus OA knee in postmenopausal women who simultaneously has osteoporosis and lower extremity varus malalignment.

Bone Scintigraphy: A Review of Technical Aspects and Applications in Orthopedic Surgery

Due to its high sensitivity, low cost, accessibility, and ease of use, bone scintigraphy is used in orthopedic surgery for the diagnosis and management of varied pathology. It is commonly used for insufficiency fractures, metastatic neoplasia, staging and surveillance of sarcoma, and nonaccidental trauma. It augments diagnoses, including stress or occult fractures, musculoskeletal neoplasia or infection, and chronic regional pain syndrome, in patients presenting with normal results on radiographs. Bone scan images are resistant to metal-based implant artifact, allowing effective evaluation of failed total joint prostheses. Bone scintigraphy remains an underused tool in the evaluation and management of orthopedic patients. [Orthopedics. 2019; 42(1):e14-e24.].

Guidelines for the management of osteoporosis and fragility fractures

The purpose of this document, a result of the harmonisation and revision of Guidelines published separately by the SIMFER, SIOMMMS/SIR, and SIOT associations, is to provide practical indications based on specific levels of evidence and various grades of recommendations, drawn from available literature, for the management of osteoporosis and for the diagnosis, prevention, and treatment of fragility fractures. These indications were discussed and formally approved by the delegates of the Italian Scientific Associations involved in the project (SIE, SIGG, SIMFER, SIMG, SIMI, SIOMMMS, SIR, and SIOT).

Percutaneous iliosacral screw fixation after osteoporotic posterior ring fractures of the pelvis reduces pain significantly in elderly patients

INTRODUCTION

Osteoporotic posterior ring fractures of the pelvis are common injuries in the elderly, but the treatment of these fractures still remains controversial. Percutaneous iliosacral screw fixation is one surgical option if conservative treatment cannot provide sufficient pain reduction. The aim of this study is to provide short-term results of elderly patients with percutaneous screw fixation.

METHODS

30 patients with posterior ring fractures were treated between 12/2009 and 01/2014 with percutaneous iliosacral screw fixation. Patients' mean age was 78.4 years. Concerning short-term outcome, we focused on initial pain level and postoperative pain reduction together with intra- and postoperative complications.

RESULTS

The average hospital stay was 23.7 days, with surgical treatment performed after an average of 9.2 days. 90% of our patients were female. All 30 patients had a lower level of pain at discharge compared with admission or immediately prior to surgery. The difference in pain level at admission compared with the pain level upon discharge showed a mean reduction from 6.8 to 1.8 with a statistically significant change (P≤0.001). 24 of 30 patients had no registered complications, one screw malpositioning with postoperative nerve irritation occurred.

DISCUSSION

Conventional percutaneous iliosacral screw fixation is a successful operative treatment for elderly patients with persistent lower back pain after unstable posterior ring fractures of the pelvis. Intra- and postoperative complications are rare, so this treatment can be regarded as a safe procedure.

LEVEL OF EVIDENCE

IV (retrospective study).

Mimickers of lumbar radiculopathy

Orthopaedic surgeons frequently treat patients who report pain that radiates from the back into the lower extremity. Although the most common etiology is either a herniated disk or spinal stenosis, a myriad of pathologies can mimic the symptoms of radiculopathy, resulting in differences in the clinical presentation and the workup. Therefore, the clinician must be able to distinguish the signs and symptoms of lumbar radiculopathy from pathologies that may have a similar presentation. Being cognizant of these other possible conditions enables the physician to consider a breadth of alternative diagnoses when a patient presents with radiating lower extremity pain.

Complex sacral fracture

We reported a case of a patient with suspected cauda equina syndrome secondary to sacral fracture, after sustaining a fall. The difficulty in early diagnosis of complex sacral fractures and the lack of clearly defined guidelines for treatment are highlighted. Thorough clinical examination is mandatory, in order to make an adequate initial assessment and follow symptoms progression and response to treatment. The threshold for performing CT imaging (or MRI, if advised), when suspecting sacral fracture and neurological compromise, should be low. A multidisciplinary approach, with contributions from orthopaedic and/or neurosurgical surgery and physiatry, should be the gold standard of treatment. In this particular case, conservative management and close follow-up led to a significant improvement of problems and a good final outcome, showing that surgical decompression is not the only valid option and that further prospective studies are needed, regarding patient selection and timing of intervention.