Differential patient responses to spinal manipulative therapy and their relation to spinal degeneration and post-treatment changes in disc diffusion.

PURPOSE: Our prior study revealed that people with non-specific low back pain (LBP) who self-reported a > 30% improvement in disability after SMT demonstrated significant post-treatment improvements in spinal stiffness, dynamic muscle thickness and disc diffusion, while those not having self-reported improvement did not have these objective changes. The mechanism underlying this differential post-SMT response remains unknown. This exploratory secondary analysis aimed to determine whether persons with non-specific LBP who respond to spinal SMT have unique lumbar magnetic resonance imaging (MRI) findings compared to SMT non-responders. METHODS: Thirty-two participants with non-specific LBP received lumbar MRI before and after SMT on Day 1. Resulting images were assessed for facet degeneration, disc degeneration, Modic changes and apparent diffusion coefficient (ADC). SMT was provided again on Day 4 without imaging. SMT responders were classified as having a ≥ 30% reduction in their modified Oswestry disability index at Day 7. Baseline MRI findings between responders and non-responders were compared. The associations between SMT responder status and the presence/absence of post-SMT increases in ADC values of discs associated with painful/non-painful segments as determined by palpation were calculated. In this secondary analysis, a statistical trend was considered as a P value between 0.05 and 0.10. RESULTS: Although there was no significant between-group difference in all spinal degenerative features (e.g. Modic changes), SMT responders tended to have a lower prevalence of severely degenerated facets (P = 0.05) and higher baseline ADC values at the L4-5 disc when compared to SMT non-responders (P = 0.09). Post hoc analyses revealed that 180 patients per group should have been recruited to find significant between-group differences in the two features. SMT responders were also characterized by significant increases in post-SMT ADC values at discs associated with painful segments identified by palpation (P < 0.01). CONCLUSIONS: The current secondary analysis suggests that the spines of SMT responders appear to differ from non-responders with respect to degeneration changes in posterior joints and disc diffusion. Although this analysis was preliminary, it provides a new direction to investigate the mechanisms underlying SMT and the existence of discrete forms of treatment-specific LBP. These slides can be retrieved under Electronic Supplementary Material.

Radiation Exposure to the Sacroiliac Joint From Low-Dose CT Compared With Radiography.

OBJECTIVE: The primary objective of this study was to estimate the effective dose delivered to the sacroiliac joint (SIJ) from low-dose (LD) CT compared with that from radiography. Secondary objectives included evaluation of diagnostic quality of LD CT of the SIJ and development of a clinical protocol for LD CT of the SIJ. MATERIALS AND METHODS: Data from 36 patients (19 women, 17 men) undergoing LD CT for suspected renal colic were analyzed. Two effective dose estimates were calculated: one for the SIJ and another for an extended region from the iliac crest to 1 cm below the SIJ. Thirty-six anteroposterior pelvic and 36 SIJ view radiographs were age-, sex-, and body width-matched to CT scans. Effective dose from radiography was estimated using the method described in International Commission on Radiologic Protection Publication 60. RESULTS: Maximum effective dose to the SIJ from LD CT was less than 1 mSv in all cases, with a mean ± SD of 0.42 ± 0.18 mSv (range, 0.14-0.83 mSv), whereas mean dose to the extended region was 0.57 ± 0.24 mSv (range, 0.19-1.11 mSv). Mean dose from SIJ radiographs was 0.15 ± 0.10 mSv (range, 0.07-1.38 mSv), and mean dose from a single pelvic radiograph was 0.09 ± 0.06 mSv (range, 0.04-0.37 mSv). All CT studies were of diagnostic quality for assessment of the SIJ. CONCLUSION: LD CT of the SIJ can be consistently performed with an effective radiation dose of less than 1 mSv. Because reliability and sensitivity of radiography for sacroiliitis is poor, we recommend that LD CT replace radiography for dedicated evaluation of the SIJ.

Analysis of a generic talar prosthetic with a biological talus: A cadaver study.

Treatment for talar avascular necrosis is challenging. This study evaluates the feasibility of a generic talar implant by cadaveric assessment. Ten cadaveric ankles were CT-scanned to determine talar implant size. The opposite ankles were CT-scanned with the biological talus and then with the implant. 3D ankle geometry was reconstructed and implant position was compared to the biological talus position. The averages among specimens' positive and negative average-deviations were 0.91 mm and 0.70 mm. Seventy percent of talar dome deviations between the biological talus and implant were within an acceptable range. This study yields promising results to support a generic talus bone prosthetic.

Do participants with low back pain who respond to spinal manipulative therapy differ biomechanically from nonresponders, untreated controls or asymptomatic controls?

STUDY DESIGN: Nonrandomized controlled study. OBJECTIVE: To determine whether patients with low back pain (LBP) who respond to spinal manipulative therapy (SMT) differ biomechanically from nonresponders, untreated controls or asymptomatic controls. SUMMARY OF BACKGROUND DATA: Some but not all patients with LBP report improvement in function after SMT. When compared with nonresponders, studies suggest that SMT responders demonstrate significant changes in spinal stiffness, muscle contraction, and disc diffusion. Unfortunately, the significance of these observations remains uncertain given methodological differences between studies including a lack of controls. METHODS: Participants with LBP and asymptomatic controls attended 3 sessions for 7 days. On sessions 1 and 2, participants with LBP received SMT (+LBP/+SMT, n = 32) whereas asymptomatic controls did not (-LBP/-SMT, n = 57). In these sessions, spinal stiffness and multifidus thickness ratios were obtained before and after SMT and on day 7. Apparent diffusion coefficients from lumbar discs were obtained from +LBP/+SMT participants before and after SMT on session 1 and from an LBP control group that did not receive SMT (+LBP/-SMT, n = 16). +LBP/+SMT participants were dichotomized as responders/nonresponders on the basis of self-reported disability on day 7. A repeated measures analysis of covariance was used to compare apparent diffusion coefficients among responders, nonresponders, and +LBP/-SMT subjects, as well as spinal stiffness or multifidus thickness ratio among responders, nonresponders, and -LBP/-SMT subjects. RESULTS: After the first SMT, SMT responders displayed statistically significant decreases in spinal stiffness and increases in multifidus thickness ratio sustained for more than 7 days; these findings were not observed in other groups. Similarly, only SMT responders displayed significant post-SMT improvement in apparent diffusion coefficients. CONCLUSION: Those reporting post-SMT improvement in disability demonstrated simultaneous changes between self-reported and objective measures of spinal function. This coherence did not exist for asymptomatic controls or no-treatment controls. These data imply that SMT impacts biomechanical characteristics within SMT responders not present in all patients with LBP. This work provides a foundation to investigate the heterogeneous nature of LBP, mechanisms underlying differential therapeutic response, and the biomechanical and imaging characteristics defining responders at baseline. LEVEL OF EVIDENCE: 3.

Percutaneous vertebroplasty for osteoporotic vertebral compression fracture.

BACKGROUND: Percutaneous vertebroplasty is widely used to treat acute and subacute painful osteoporotic vertebral fractures although recent placebo-controlled trials have questioned its value. OBJECTIVES: To synthesise the available evidence regarding the benefits and harms of vertebroplasty for treatment of osteoporotic vertebral fractures. SEARCH METHODS: We searched CENTRAL, MEDLINE and EMBASE up to November 2014. We also reviewed reference lists of review articles, trials and trial registries to identify any other potentially relevant trials. SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials (RCTs) including adults with painful osteoporotic vertebral fractures of any duration and comparing vertebroplasty with placebo (sham), usual care, or any other intervention. As it is least prone to bias, vertebroplasty compared with placebo was the primary comparison. Major outcomes were mean overall pain, disability, disease-specific and overall health-related quality of life, patient-reported treatment success, new symptomatic vertebral fractures and number of other serious adverse events. DATA COLLECTION AND ANALYSIS: At least two review authors independently selected trials for inclusion, extracted data, performed 'Risk of bias' assessment and assessed the quality of the body of evidence for the main outcomes using GRADE. MAIN RESULTS: Eleven RCTs and one quasi-RCT conducted in various countries were included. Two trials compared vertebroplasty with placebo (209 randomised participants), six compared vertebroplasty with usual care (566 randomised participants) and four compared vertebroplasty with kyphoplasty (545 randomised participants). Trial size varied from 34 to 404 participants, most participants were female, mean age ranged between 63.3 and 80 years, and mean symptom duration varied from a week to more than six months.Both placebo-controlled trials were judged to be at low overall risk of bias while other included trials were generally considered to be at high risk of bias across a range of criteria, most seriously due to lack of participant and study personnel blinding.Compared with placebo, there was moderate quality evidence based upon two trials that vertebroplasty provides no demonstrable benefits with respect to pain, disability, disease-specific or overall quality of life or treatment success. At one month, mean pain (on a scale 0 to 10, higher scores indicate more pain) was 5 points with placebo and 0.7 points better (1.5 better to 0.15 worse) with vertebroplasty, an absolute pain reduction of 7% (15% better to 1.5% worse) and relative reduction of 10% (21% better to 2% worse) (two trials, 201 participants). At one month, mean disability measured by the Roland Morris Disability Questionnaire (scale range 0 to 23, higher scores indicate worse disability) was 13.6 points in the placebo group and 1.1 points better (2.9 better to 0.8 worse) in the vertebroplasty group, absolute improvement in disability 4.8% (12.8% better to 3.3% worse), relative change 6.3% better (17.0% better to 4.4% worse) (two trials, 201 participants).At one month, disease-specific quality of life measured by the QUALEFFO (scale 0 to 100, higher scores indicating worse quality of life) was 2.4 points in the placebo group and 0.40 points worse (4.58 better to 5.38 worse) in the vertebroplasty group, absolute change: 0.4% worse (5% worse to 5% better), relative change 0.7% worse (9% worse to 8% better (based upon one trial, 73 participants). At one month overall quality of life measured by the EQ5D (0 = death to 1 = perfect health, higher scores indicate greater quality of life at one month was 0.27 points in the placebo group and 0.05 points better (0.01 worse to 0.11 better) in the vertebroplasty group, absolute improvement in quality of life 5% (1% worse to 11% better), relative change 18% better (4% worse to 39% better) (two trials, 201 participants). Based upon one trial (78 participants) at one month, 9/40 (or 225 per 1000) people perceived that treatment was successful in the placebo group compared with 12/38 (or 315 per 1000; range 150 to 664) in the vertebroplasty group, RR 1.40 (95% CI 0.67 to 2.95), absolute risk difference 9% more reported success (11% fewer to 29% more); relative change 40% more reported success (33% fewer to 195% more).Based upon moderate quality evidence from three trials (one placebo, two usual care, 281 participants) with up to 12 months follow-up, we are uncertain whether or not vertebroplasty increases the risk of new symptomatic vertebral fractures (28/143 observed in the vertebroplasty group compared with 19/138 in the control group; RR 1.47 (95% CI 0.39 to 5.50).Similary, based upon moderate quality evidence from two placebo-controlled trials (209 participants), we are uncertain about the exact risk of other adverse events (3/106 were observed in the vertebroplasty group compared with 3/103 in the placebo group; RR 1.01 (95% CI 0.21 to 4.85)). Notably, serious adverse events reported with vertebroplasty included osteomyelitis, cord compression, thecal sac injury and respiratory failure.Our subgroup analyses provided limited evidence that the effects did not differ according to duration of pain ≤ 6 weeks versus > 6 weeks. Including data from the six trials that compared vertebroplasty with usual care in a sensitivity analyses inconsistently altered the primary results, with all combined analyses displaying substantial to considerable heterogeneity. AUTHORS' CONCLUSIONS: Based upon moderate quality evidence, our review does not support a role for vertebroplasty for treating osteoporotic vertebral fractures in routine practice. We found no demonstrable clinically important benefits compared with a sham procedure and subgroup analyses indicated that results did not differ according to duration of pain ≤ 6 weeks versus > 6 weeks. Sensitivity analyses confirmed that open trials comparing vertebroplasty with usual care are likely to have overestimated any benefit of vertebroplasty. Correcting for these biases would likely drive any benefits observed with vertebroplasty towards the null, in keeping with findings from the placebo-controlled trials.Numerous serious adverse events have been observed following vertebroplasty. However due to the small number of events, we cannot be certain about whether or not vertebroplasty results in a clinically important increased risk of new symptomatic vertebral fractures and/or other serious adverse events. Patients should be informed about both the lack of high quality evidence supporting benefit of vertebroplasty and its potential for harm.

Meniscal injury after adolescent anterior cruciate ligament injury: how long are patients at risk?

BACKGROUND: Delay of as much as 5 months between ACL injury and surgery is known to be associated with increased risk of a medial meniscal tear, but the risk of additional meniscal tear progression with a longer delay to surgery is unclear. QUESTIONS/PURPOSES: We determined the (1) times of injury, MRI, and surgery in adolescents with ACL tears, and whether (2) timing of surgery, or (3) initial integrity of the meniscus seen on MR images predicted development of meniscal tears. METHODS: We reviewed 112 adolescents who were 15 ± 1 years old (mean ± SD) (range, 11-16 years) with a torn ACL. These patients underwent surgical repair from 2005 to 2011 in a Canadian city. We compared dates of injury, MRI, and surgery. A pediatric and musculoskeletal fellowship-trained radiologist reread the MR images, and meniscal injuries were graded according to severity. This was compared with surgical findings described in the operative report. RESULTS: Time after injury to MRI and surgery averaged 77 days (range, 1-377 days) and 342 days (range, 42-1637 days), respectively. Patients with new or worsened medial meniscal tears had waited longer for surgery (445 versus 290 days; p = 0.002). Bucket handle medial meniscal tears were more common in patients with surgery more than 1 year after injury than others (15 of 34 versus 14 of 75; p = 0.013). A medial meniscal tear observed on MR images was a significant covariate for a torn meniscus at surgery (relative risk, 5.7; 95% CI, 2.8-11.6). Medial meniscal survival continued to decline sharply greater than 1 year after injury. CONCLUSIONS: Medial meniscal tears, especially bucket handle tears, increased steadily in frequency more than 1 year after ACL injury. Timely ACL reconstruction may be warranted to reduce the risk of further medial meniscal damage even in patients whose original injury occurred more than 1 year before. LEVEL OF EVIDENCE: Level IV, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

Advanced imaging of the axial skeleton in spondyloarthropathy: techniques, interpretation, and utility.

The development of available treatments for spondyloarthritis increases the need for accurate diagnosis and objective monitoring of response to therapy. Advances in MRI technology are improving the effectiveness of imaging of the sacroiliac joints and spine in spondyloarthritis. We discuss best practice techniques for MR image acquisition and interpretation with a view to optimizing the diagnostic utility of MRI in spondyloarthritis.

Accuracy and reliability of MRI vs. laboratory measurements in an ex vivo porcine model of arthritic cartilage loss.

PURPOSE: To quantify the accuracy of magnetic resonance imaging (MRI) measurement of change in cartilage volume due to thin linear excisions, simulating arthritic cartilage losses, by comparison with laboratory volume measurements in an ex vivo porcine model. MATERIALS AND METHODS: We scanned 15 porcine patellae by T1-weighted spoiled gradient echo (SPGR) MRI at baseline and after excision of up to three thin layers of articular cartilage. Excised fragment volume was determined from density and weight. Postexcision scans were "fused" to the baseline scan by three-dimensional (3D) registration. This allowed automated recalculation of the remaining cartilage volume within a baseline region of interest (ROI) following each excision. We compared MRI estimates of change in cartilage volume to direct laboratory measurement of fragment volume. RESULTS: Our 38 excised fragments averaged 0.16 mL, or approximately 7% of cartilage volume. MRI and laboratory estimates of total cartilage volume loss differed by 1.6% +/- 13.2% (mean, coefficient of variation [CV]). Accuracy was +/-0.1 mL for 95% of scans. CONCLUSION: MRI estimates of small changes in porcine patellar cartilage volume were unbiased, reliable, and accurate to 0.1 mL. Despite a proportionately high error in the very thin fragments tested, achievement of similar accuracy in vivo would be adequate to detect approximately two years of osteoarthritic cartilage loss.

Humeral head cysts and rotator cuff tears: an MR arthrographic study.

OBJECTIVE: Humeral tuberosity cysts are a common finding, with previous reports suggesting they are related to rotator cuff tear or aging. The aim of this study was to investigate the characteristics of cysts in the tuberosities of the humeral head and their relationship with rotator cuff tear and age. DESIGN AND PATIENTS: Shoulder MR arthrograms were reviewed in 120 consecutive patients-83 males (mean age 38.0, range 19-59 years) and 37 females (mean age 41.2, range 15-59 years). Patients were referred for investigation of a variety of conditions, and instability was suspected in only a minority of cases. MR was performed before and after direct arthrography with 0.01% solution of gadolinium. Cysts were defined as well-demarcated circular/ovoid foci in two planes that demonstrated high signal on pre-arthrographic T2W sequences. Location, size and numbers of cysts and post-arthrographic enhancement were documented, along with the location of rotator cuff tears, if present. RESULTS: Cysts in the tuberosities of the humerus were identified in 84 patients (70%), and were seen seven times more frequently in the posterior aspect of the greater tuberosity than anteriorly. Most cysts (94%) demonstrated communication with the joint post-arthrogram. Rotator cuff tears were present in 36 patients, and 79% of all tears occurred in supraspinatus tendon. There was no significant difference in the occurrence of cysts between patients older or younger than age 40 or between genders, but rotator cuff tears were seen significantly more often in the older age group (p<0.01). Tuberosity cysts and rotator cuff tears did not appear to be related (p=0.55). However, whilst this lack of association was quite obvious posteriorly (p=0.84), the trend in the anterior aspect of the greater tuberosity is not as clear (p=0.14). CONCLUSIONS: Humeral cysts are most often located in the posterior aspect of the greater tuberosity, communicate with the joint space and, in this location, are not related to aging or rotator cuff tear.

High prevalence of symptomatic enthesopathy of the shoulder in ankylosing spondylitis: deltoid origin involvement constitutes a hallmark of disease.

OBJECTIVE: To examine the prevalence and characteristics of shoulder involvement in ankylosing spondylitis (AS). To analyze the sensitivity and specificity of shoulder lesions defined by magnetic resonance imaging (MRI) in patients with AS. METHODS: Prevalence of shoulder involvement was ascertained by chart review of 400 AS patients. One hundred of these patients and 285 controls were selected for clinical evaluation. AS patients with a clinically defined shoulder disorder (n = 15) and a control group of 91 patients (94 shoulders) with nonspecific shoulder pain were studied with MRI. Fifty-four MRI-defined variables per shoulder were analyzed by 2 observers. A third cohort of patients with AS (n = 76) was prospectively evaluated by clinical exam for AS-specific shoulder lesions identified on MRI. RESULTS: Shoulder pain was recorded in 3.5% of patients by chart review. Shoulder involvement by clinical evaluation was noted in 24.7% of patients versus 14.2% of controls (odds ratio [OR] 8.17, 95% confidence interval [95% CI] 3.14-21.28, P < 0.001). Rotator cuff tendinitis was significantly more prevalent in patients (15.1%) than controls (3.5%; OR 8.17, 95% CI 2.66-25.14, P < 0.001). Acromioclavicular joint arthrosis was the most common lesion observed in AS shoulders (94%), although specificity was low (32%). Bone marrow edema at any entheseal site was noted in significantly more AS shoulders (70.6%) than in control (19.1%) shoulders (P < 0.001, corrected P = 0.02). Erosion of the greater tuberosity with or without adjacent bone edema had the best combination of sensitivity (58-65%) and specificity (86-92%). Intense acromial entheseal edema at the deltoid origin was observed only in AS shoulders (41.2%; P < 0.001). Evaluation of a prospective cohort of patients with AS showed that 22.4% had rotator cuff enthesopathy. CONCLUSION: Shoulder lesions in AS are common and characterized clinically by rotator cuff tendinitis and on MRI by intense bone edema localized to the supraspinatus/greater tuberosity and deltoid/acromial entheses. Intense acromial bone edema at the deltoid origin is a hitherto undescribed and highly specific feature of AS. Enthesopathy of the rotator cuff is underrecognized in AS and should be incorporated into instruments measuring enthesitis.