The Use of 18F-Fluoride Positron Emission Tomography/Computed Tomography Scanning to Identify Sources of Pain after Posterior Lumbar Interbody Fusion-An Analysis in Patients with and without Symptoms.

BACKGROUND: Identifying the cause of recurrent or persisting pain after posterior lumbar interbody fusion (PLIF) is essential for establishing optimal treatment. In this study, we evaluate patients after PLIF surgery by 18F-fluoride PET/CT scans and patient-reported outcome measures (PROMs). METHODS: A total of 36 PLIF patients were included. Sixty minutes after intravenous injection of 18F-fluoride, PET/CT scanning was performed. Bone graft ingrowth, subsidence, screw loosening and damage of facet joints were scored by quantifying the level of bone metabolism of the vertebral endplates in the disc spaces, around screws and around the facet joints on the PET scans. RESULTS: In contrast to asymptomatic patients, symptomatic patients showed abnormal PET values around pedicle screws and/or facet joints and at the lower endplates of the disc spaces, identifying a possible source of pain. On CT, no significant differences between these two groups were found. CONCLUSION: The PET/CT findings appeared to correlate better with symptoms on PROMs compared to CT findings alone. When interpreting 18F-fluoride PET/CT findings after PLIF surgery, one should realize bone metabolism in the disc spaces of the operated segments and around pedicle screws or facet joint changes during follow-up, reflecting natural recovery.

Multiplanar reformation computed tomography for carpal malalignment.

Correct interpretation of scaphoid axial length and carpal malalignment is difficult owing to the complex geometry of the scaphoid. Traditional measurements, such as the scapholunate angle and radiolunate angle, have shown limited reproducibility. To improve the assessment of these measurements, we used multiplanar reformation computed tomography with added average intensity projection. Four measurements for scaphoid morphology and carpal alignment were independently measured by four observers on computed tomography scans of 39 consecutive patients who were treated conservatively for scaphoid fracture. Fleiss's kappa for categorical results showed substantial agreement for the measurements of the scapholunate and radiolunate angles. Intraclass correlation coefficients were significant for measurements of the axial length, scapholunate angle and radiolunate angle. Our results suggest that multiplanar reformation computed tomography with added average intensity projection is a reliable technique for assessment of scaphoid morphology and carpal alignment. Level of evidence: II.

The diagnostic accuracy of imaging modalities to detect pseudarthrosis after spinal fusion-a systematic review and meta-analysis of the literature.

OBJECTIVE: The aim of the study was to determine the diagnostic accuracy of imaging modalities to detect pseudarthrosis after thoracolumbar spinal fusion, with surgical exploration as reference standard. MATERIALS AND METHODS: A systematic literature search for original studies was performed on the diagnostic accuracy of imaging as index test compared to surgical exploration as reference standard to diagnose pseudarthrosis after thoracolumbar spinal fusion. Diagnostic accuracy values were extracted and methodologic quality of studies was evaluated by the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Per modality, clinically comparable studies were included in subgroup meta-analysis and weighted odds ratios (ORs) were calculated using the random effects model. RESULTS: Fifteen studies were included. Risk of bias was classified as high/unclear in 58% of the studies. Concerns of applicability was classified as high/unclear in 40% of the studies. Four scintigraphy studies including 93 patients in total were pooled to OR = 2.91 (95% confidence interval [CI]: 0.93-9.13). Five studies on plain radiography with 398 patients in total were pooled into OR = 7.07 (95% CI: 2.97-16.86). Two studies evaluating flexion-extension radiography of 75 patients in total were pooled into OR = 4.00 (95% CI: 0.15-105.96). Two studies of 68 patients in total were pooled for CT and yielded OR = 17.02 (95% CI: 6.42-45.10). A single study reporting on polytomography, OR = 10.15 (95% CI 5.49-18.78), was also considered to be an accurate study. CONCLUSIONS: With a pooled OR of 17.02, CT can be considered the most accurate imaging modality for the detection of pseudarthrosis after thoracolumbar spinal fusion from this review.

Added value of 18F-FDG PET/CT in diagnosing infected hip prosthesis.

Background The diagnosis of infected hip prosthesis is frequently not straightforward yet very important as it changes treatment. Purpose To retrospectively investigate the added value of 18F-FDG PET/CT to conventional tests including radiography, erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP) testing, and joint aspiration, in diagnosing infected hip prosthesis. Material and Methods Seventy-eight hip prostheses of 78 patients (55% men; mean age = 66.5 years; age range = 30-85 years) with non-specific clinical presentation, i.e. no abscess or sinus tract communicating with the joint space at clinical examination, were analyzed. Cultures of intra-articular fluid and peri-implant tissues after revision surgery or clinical follow-up ≥6 months served as gold standard. Areas under the receiver operating characteristic curves (AUCs) of radiography, ESR/CRP testing, aspiration culture, and white blood cell (WBC) count without and with the addition of 18F-FDG PET/CT were compared. Results The addition of 18F-FDG PET/CT increased AUCs: for radiography with 0.212, P = 0.001; for ESR/CRP testing with 0.076, P = 0.072; for aspiration culture with 0.126, P = 0.032; and for aspiration WBC count with 0.191, P = 0.035. Conclusion This study shows that 18F-FDG PET/CT adds to individual conventional tests in diagnosing infected hip prosthesis. It may improve the preoperative planning and should therefore be considered in the diagnostic work-up. Future studies should define the exact place of 18F-FDG PET/CT in the diagnostic work-up of periprosthetic joint infection.

Ultrasound imaging to tailor the treatment of acute shoulder pain: a randomised controlled trial in general practice.

OBJECTIVE: To determine the clinical effectiveness of ultrasound tailored treatment in patients with acute subacromial disorders. DESIGN: Pragmatic randomised controlled trial. SETTING: Dutch general practice. PARTICIPANTS: Patients aged 18-65 years with acute (duration <3 months) unilateral shoulder pain and no previous treatment, in whom the general practitioner suspected a subacromial disorder was enrolled. INTERVENTIONS: All patients underwent ultrasound imaging of the affected shoulder. Patients who were still symptomatic after a qualification period of 2 weeks with standard treatment were randomised to treatment tailored to ultrasound diagnosis (disclosure of the ultrasound diagnosis) or usual care (non-disclosure of the ultrasound diagnosis). PRIMARY OUTCOME MEASURE: Patient-perceived recovery using the Global Perceived Effect questionnaire at 1 year. RESULTS: 129 patients were included. 18 patients recovered during the 2-week qualification period, resulting in 111 randomised patients; 56 were allocated to ultrasound tailored treatment and 55 to usual care. After 1 year, no statistically significant differences in recovery were found between the ultrasound tailored treatment group (72.5% (37/51)) and the usual care group (60% (30/50), OR 2.24 (95% CI 0.72 to 6.89; p=0.16)). Also, healthcare use was similar. CONCLUSIONS: This study has shown no clinically significant difference in the primary outcome measure between the ultrasound tailored treatment and usual care groups. Furthermore, there was no overall difference in healthcare resources used between groups. Although no formal cost data are included, one can only assume that the ultrasound examinations are additional costs for the intervention group, which cannot be justified in routine practice based on this trial. Based on this study, no change in current pragmatic guidelines to incorporate early ultrasound imaging can be recommended. TRIAL REGISTRATION NUMBER: NTR2403; Results.

F-18 FDG PET/CT for detecting bone and bone marrow involvement in sarcoidosis patients.

BACKGROUND: The prevalence of bone involvement in sarcoidosis has been estimated to be 3% to 5%, mostly affecting the phalanges. The aim of this study was to assess the prevalence and distribution pattern of bone and bone marrow involvement as detected by positron emission tomography/computed tomography (PET/CT) in sarcoidosis patients. METHODS: Between June 2006 and September 2010, 122 patients suffering from severe sarcoidosis who underwent a PET/CT and met the inclusion criteria were studied. In 94 (77%) patients, the PET/CT demonstrated positive findings associated with sarcoidosis. The 94 PET/CTs were screened for the presence of bone/bone marrow localizations. Additionally, low-dose CT scans were screened for other causes of increased bone uptake. Relevant clinical data were gathered retrospectively. RESULTS: Evidence for bone/bone marrow localizations was found in 34% of the 94 patients with PET/CT-positive findings. Of these patients, 60% showed obvious focal bone lesions at various localizations: axial skeleton (47%), pelvis (40%), extremities (34%), and skull (2%). In 40% of patients, diffuse increased uptake in both axial and peripheral bone marrow, without focal lesions, was found. Both diffuse and focal uptake were seen in 34%, whereas only focal lesions were observed in 25%. In all but 2 (6%) patients, no bone abnormalities on low-dose CT were found. CONCLUSIONS: More than one-third of PET/CT-positive sarcoidosis patients had osseous abnormalities on PET/CT. The majority of these lesions (94%) could not be detected on low-dose CT. No single localization of preference was found. These preliminary results stress the value of PET/CT imaging in the assessment of bone/bone marrow involvement in sarcoidosis patients.

The Maastricht Ultrasound Shoulder pain trial (MUST): ultrasound imaging as a diagnostic triage tool to improve management of patients with non-chronic shoulder pain in primary care.

BACKGROUND: Subacromial disorders are considered to be one of the most common pathologies affecting the shoulder. Optimal therapy for shoulder pain (SP) in primary care is yet unknown, since clinical history and physical examination do not provide decisive evidence as to the patho-anatomical origin of the symptoms. Optimal decision strategies can be furthered by applying ultrasound imaging (US), an accurate method in diagnosing SP, demonstrating a clear relationship between diagnosis and available therapies. Yet, the clinical cost-effectiveness of applying US in the management of SP in primary care has not been studied. The aim of this paper is to describe the design and methods of a trial assessing the cost-effectiveness of ultrasound imaging as a diagnostic triage tool to improve management of primary care patients with non-chronic shoulder pain. METHODS/DESIGN: This randomised controlled trial (RCT) will involve 226 adult patients with suspected subacromial disorders recruited by general practitioners. During a Qualification period of two weeks, patients receive care as usual as advised by the Dutch College of General Practitioners, and patients are referred for US. Patients with insufficient improvement qualify for the RCT. These patients are then randomly assigned to the intervention or the control group. The therapies used in both groups are the same (corticosteroid injections, referral to a physiotherapist or orthopedic surgeon) except that therapies used in the intervention group will be tailored based on the US results. Ultrasound diagnosed disorders include tendinopathy, calcific tendinitis, partial and full thickness tears, and subacromial bursitis. The primary outcome is patient-perceived recovery at 52 weeks, using the Global Perceived Effect questionnaire. Secondary outcomes are disease specific and generic quality of life, cost-effectiveness, and the adherence to the initial applied treatment. Outcome measures will be assessed at baseline, 13, 26, 39 and 52 weeks after inclusion. An economic evaluation will be performed from both a health care and societal perspective with a time horizon of 52 weeks. DISCUSSION: The results of this trial will give unique evidence regarding the cost-effectiveness of US as a diagnostic triage tool in the management of SP in primary care.

F-18 FDG PET/CT scanning in Charcot disease: a brief report.

PURPOSE: because of the increasing prevalence of diabetes, complications of diabetes will also become more prevalent. The pathophysiology of Charcot neuro-osteoarthropathy (Charcot disease) as a complication of diabetes is still enigmatic. As a consequence, the optimal diagnostic, follow-up, and therapeutic strategies are unclear. To obtain more insight into the relation between bony abnormalities and the (concurrent) inflammatory response in acute Charcot disease, thereby creating more insight into the pathophysiology of this disease, we performed F-18 FDG PET/CT scanning. RESEARCH DESIGN AND METHODS: We performed F-18 FDG PET/CT and Tc-99m bone scintigraphy in 10 patients with Charcot disease. Bony abnormalities on CT-scan and areas of increased uptake on F-18 FDG PET and Tc-99m bone scintigraphy were assessed independently. Subsequently, fused PET/CT images were evaluated for number and location of PET lesions. RESULTS: nine patients had increased uptake of F-18 FDG, indicating inflammation, in 25 areas of soft tissue and/or bone without concurrent bony abnormalities on CT. CONCLUSIONS: presented F-18 FDG PET/CT data may indicate an inflammatory origin of Charcot disease, with secondary bone resorption, possibly due to decreased inhibitory neurogenic inflammatory responses as a result of small fiber neuropathy. If these findings can be confirmed in future studies, F-18 FDG PET/CT scanning may be added to the diagnostic arsenal in Charcot disease, and anti-inflammatory drugs may be added to the therapeutic arsenal.

Accuracy of diagnostic ultrasound in patients with suspected subacromial disorders: a systematic review and meta-analysis.

OBJECTIVE: To determine the diagnostic accuracy of ultrasound for detecting subacromial disorders in patients presenting in primary and secondary care settings. DATA SOURCES: Medline and Embase were searched on June 9, 2010. In addition, the reference list of 1 systematic review and all included articles were searched to identify relevant studies. STUDY SELECTION: Two reviewers independently selected the articles evaluating the accuracy of ultrasound for detecting subacromial disorders from the title and abstracts retrieved by the literature search. Selection criteria were ultrasound frequency greater than or equal to 7.5MHz as index test, surgery, magnetic resonance imaging and/or radiography as reference standards, and subacromial disorders as target conditions. DATA EXTRACTION: Two reviewers independently extracted the data on study characteristics and results to construct 2 by 2 tables and performed a methodologic quality assessment. DATA SYNTHESIS: Twenty-three studies were included: 22 reported on full-thickness rotator cuff tears, 15 on partial-thickness tears, 3 on subacromial bursitis, 2 on tendinopathy, and 2 on calcifying tendonitis, respectively. For full-thickness tears, pooled sensitivity of ultrasound was .95 (95% confidence interval, .90-.97), and specificity .96 (.93-.98). For partial-thickness tears, pooled sensitivity was .72 (.58-.83), and specificity .93 (.89-.96). Statistical pooling was not possible for the other disorders. For subacromial bursitis, sensitivity ranged from .79 to .81, and specificity from .94 to .98. For tendinopathy, sensitivity ranged from .67 to .93, specificity from .88 to 1.00. Sensitivity for calcifying tendonitis was 1.00 in both studies, with specificity ranging from .85 to .98. CONCLUSIONS: We strongly recommend ultrasound in patients for whom conservative treatment fails, to rule in or out full-thickness tears, to rule in partial-thickness tears, and to a lesser extent to diagnose tendinopathy, subacromial bursitis, and calcifying tendonitis. These results can help physicians tailor treatment.

The damping properties of the venous plexus of the heel region of the foot during simulated heelstrike.

The damping mechanisms that are operational in the heel pad during the impact phase of locomotion have the important function to protect the musculo-skeletal system from injuries. How this is achieved is still not fully understood, as is for instance illustrated by the 'heel pad paradox', the observation that in vivo and in vitro experiments yielded widely different results. This paradox could so far only partially be explained. In the light of this paradox, and a previous study by our group, we conjectured that the venous plexus might contribute as a hydraulic shock absorber to the damping properties of the heel pad. To investigate this hypothesis in vivo, heel pads of 11 volunteers were subjected to pendulum impact tests, using velocities of 0.2, 0.4, and 0.6 m/s, and three physiologically different, consecutive conditions: (i) a relatively empty venous plexus, (ii) a congested venous plexus, and (iii) a decongested venous plexus. At congestion, the maximum impact force decreased slightly but significantly by 2.6% at 0.2 m/s and 1.8% at 0.4 m/s. This effect was no longer found at 0.6 m/s. Although these effects are rather small, they confirm the fundamental hypothesis that the venous plexus contributes to the damping properties of the heel pad during walking. It is likely that some underestimation of the effect has occurred.

Effect of tube angulation on the measurement of intermetatarsal angles.

We systematically investigated the effect of tube angulation on angular distortion of the anteroposterior radiograph of the foot. Three-dimensional data from the metatarsals originating from computed tomographic scans of ten healthy volunteers were projected onto the supporting surface at various tube angulations to simulate radiography. The distortion of the intermetatarsal angles decreased from 1.2 degrees to 3.5 degrees at 20 degrees tube angulation to 0.4 degrees to 2.7 degrees at 0 degrees tube angulation. The relatively small improvement in angular measurement using 0 degrees instead of 15 degrees tube angulation would not outweigh the adverse effects of changing the standard radiographic technique. Physician awareness of this source of error when planning surgical therapy seems more important.

Three-dimensional reconstruction of magnetic resonance images of a displaced flexor hallucis longus tendon in hallux valgus.

By using three-dimensional magnetic resonance image reconstruction, lateral displacement of the flexor hallucis longus tendon and sesamoid bones was made clearly visible in a living patient. This finding supports a biomechanical model related to disturbed muscle balance at the first metatarsophalangeal joint, which could play an important role in the pathogenesis of hallux valgus and metatarsus primus varus.

Plantar pressure and sole thickness of the forefoot.

BACKGROUND: Based on earlier observations that the forefoot bears the highest plantar pressure at its center, the existence of a functional distal transverse arch in normal feet was denied, and plantar pressure was defined as merely the outcome of loading, surface area, and soft tissue. Although plantar pressure drives the changes in the foot, neither the position nor the behavior of the metatarsals during loading can be derived from plantar pressure alone. In light of this, our goal was to describe the changes in thickness in the sole and the corresponding plantar pressure during loading of the foot. METHODS: We used CT to image the foot of 10 subjects in four postures that were chosen to imitate four phases in the walking cycle. Before imaging we also recorded the plantar pressure with a pressure measuring insole on which the subjects were standing. From the data, the minimal thickness of the sole and the corresponding plantar pressure were derived. RESULTS: With the exception of the sesamoids, the thickness of the sole under the bones of the forefoot increased from lateral to medial. This persisted in all postures. Our pressure readings matched previously reported distributions. CONCLUSIONS: Depending on the point of view concerning the sesamoids, the bony prominences were placed in a geometrical arch; but they did not form a functional arch. The soft tissue underneath the heads kept the metatarsals in place; the soft-tissue thickness reflected the principle of adequate cushioning.

The relationship of the position of the metatarsal heads and peak plantar pressure.

We test the premise that peak plantar pressure is located directly under the bony prominences in the forefoot region. The right foot of standing volunteers was examined in three different postures by a CT-scanner. The plantar pressure distribution was simultaneously recorded. The position of the metatarsal heads and the sesamoids could be related to the corresponding local peak plantar pressures. The metatarsal heads 1, 4, and 5 had a significantly different position than the local peak plantar pressures. The average difference in distance between the position of the metatarsal heads and the peak plantar pressure showed a significant correlation: on the medial side the head was located more distally to the local peak plantar pressure, on the lateral side more proximally. The findings suggest that normal plantar soft tissue is able to deflect a load. The observations might improve insight into the function of the normal forefoot and might direct further research on the pathological forefoot and on the design of footwear.