Sacroiliac Joint Diagnostic Block and Radiofrequency Ablation Techniques.

Radiofrequency ablation (RFA) is a potential treatment for those with sacroiliac joint (SIJ) pain. There is no consensus on the optimal procedural techniques for SIJ diagnostic blocks, or RFA. This article describes different techniques for SIJ diagnostic blocks and RFA, including the relevant innervation that underlies these techniques. SIJ RFA techniques differ in important ways, including lesioning techniques, needle placements, and type of RFA cannula used. Clinicians utilize a variety of image guidance modalities for SIJ RFA; fluoroscopic guidance is standard, although endoscopic and ultrasound-guided techniques are described. Additional studies are necessary to delineate potential differences between SIJ RFA techniques.

A Controlled Trial Evaluating the Safety and Effectiveness of Ultrasound-Guided Looped Thread Carpal Tunnel Release.

Background: Open carpal tunnel release typically requires several weeks of recovery. A less invasive, ultrasound-guided percutaneous technique of releasing the transverse carpal ligament using a thread (thread carpal tunnel release [TCTR]) has been described. To date, its clinical effectiveness and safety have been evaluated exclusively by the group that developed the technique, using a single outcome measure without a control comparison. The objective of this study was to independently evaluate the safety and effectiveness of TCTR using multiple outcome measures and a control comparison. Methods: A convenience sample of 20 participants with refractory moderate or severe carpal tunnel syndrome underwent TCTR of their most symptomatic hand. Outcome measures included pre-TCTR and 1-, 3-, and 6-month post-TCTR Boston questionnaire; pre-, 3-, and 6-month post-TCTR monofilament sensibility, strength, ultrasound, and electrodiagnostic testing; weekly post-TCTR phone interviews for 1 month; and satisfaction surveys at 3 and 6 months post-TCTR. Results: No complications were reported. During the month post-TCTR, significant prompt improvements in hand pain and dysfunction occurred. The following significant improvements were demonstrated in the treated versus control hand: Boston Questionnaire scores, median nerve distal motor latency, transcarpal tunnel motor and sensory conduction velocities and sensory nerve action potential amplitudes. No significant differences in sensibility, pinch or grip strength, median nerve cross-sectional area (CSA) at the carpal tunnel inlet, or wrist: forearm median nerve CSA ratio were documented between TCTR and control sides. Satisfaction with the TCTR procedure was high (85%-90%). Conclusions: This study supports previous reports that the TCTR procedure is safe and effective.

A Cadaveric Study Evaluating the Feasibility of an Ultrasound-Guided Diagnostic Block and Radiofrequency Ablation Technique for Sacroiliac Joint Pain.

BACKGROUND AND OBJECTIVES: Ultrasound (US)-guided diagnostic block/radiofrequency ablation (RFA) along the lateral sacral crest (LSC) has been proposed for managing sacroiliac joint (SIJ) pain. We sought to investigate (1) ease of visualization of bony landmarks using US; (2) consistency of US-guided needle placement along the LSC; and (3) percentage of the posterior sacral network (PSN) innervating the SIJ complex that would be captured if an RFA strip lesion were created between the needles. METHODS: In 10 cadaveric specimens, 3 needles were placed bilaterally along the LSC from the first to third transverse sacral tubercles (TSTs) using US guidance. The PSN, SIJ, and needles were exposed, digitized, and modeled 3-dimensionally. Ease of visualization of bony landmarks, frequency of needle placement along the LSC, and percentage of the PSN that would be captured if an RFA strip lesion were created between the needles were determined. RESULTS: The LSC, TST2, TST3, and first to third posterior sacral foramina were easily visualized using US; TST1 was somewhat obscured by the iliac crest in some specimens. Needles were placed along the LSC in 18 of 20 specimens; in the first 2 of 20 specimens, needle 1 was placed at the L5/S1 facet joint. On average, 93% (95% confidence interval, 87%-98%) of the PSN would be captured if an RFA strip lesion were created between the needles. CONCLUSIONS: The findings suggest that US-guided needle placement along the LSC is consistent and could capture most or all of the PSN. A clinical study evaluating the outcomes of this technique is in progress.

Sacro-Iliac Joint Sensory Block and Radiofrequency Ablation: Assessment of Bony Landmarks Relevant for Image-Guided Procedures.

Image-guided sensory block and radiofrequency ablation of the nerves innervating the sacro-iliac joint require readily identifiable bony landmarks for accurate needle/electrode placement. Understanding the relative locations of the transverse sacral tubercles along the lateral sacral crest is important for ultrasound guidance, as they demarcate the position of the posterior sacral network (S1-S3 ± L5/S4) innervating the posterior sacro-iliac joint. No studies were found that investigated the spatial relationships of these bony landmarks. The purpose of this study was to visualize and quantify the interrelationships of the transverse sacral tubercles and posterior sacral foramina to inform image-guided block and radiofrequency ablation of the sacro-iliac joint. The posterior and lateral surfaces of 30 dry sacra (15 M/15 F) were digitized and modeled in 3D and the distances between bony landmarks quantified. The relationships of bony landmarks (S1-S4) were not uniform. The mean intertubercular and interforaminal distances decreased from S1 to S4, whereas the distance from the lateral margin of the posterior sacral foramina to the transverse sacral tubercles increased from S1 to S3. The mean intertubercular distance from S1 to S3 was significantly (p < 0.05) larger in males. The interrelationships of the sacral bony landmarks should be taken into consideration when estimating the site and length of an image-guided strip lesion targeting the posterior sacral network.

A Rapid Method for Refolding Cell Surface Receptors and Ligands.

Production of membrane-associated cell surface receptors and their ligands is often a cumbersome, expensive, and time-consuming process that limits detailed structural and functional characterization of this important class of proteins. Here we report a rapid method for refolding inclusion-body-based, recombinant cell surface receptors and ligands in one day, a speed equivalent to that of soluble protein production. This method efficiently couples modular on-column immobilized metal ion affinity purification and solid-phase protein refolding. We demonstrated the general utility of this method for producing multiple functionally active immunoreceptors, ligands, and viral decoys, including challenging cell surface proteins that cannot be produced using typical dialysis- or dilution-based refolding approaches.

Effectiveness of osteopathic manipulative treatment for carpal tunnel syndrome: a pilot project.

CONTEXT: Osteopathic manipulative treatment (OMT) has been recognized as a management option for carpal tunnel syndrome (CTS), although limited research exists to substantiate its effectiveness. OBJECTIVE: To evaluate the effectiveness of OMT in the management of CTS. METHODS: This single-blinded quasi-controlled trial was conducted at an academic institution. Participants with CTS underwent weekly OMT sessions for 6 consecutive weeks. The main outcome measures were the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ), a sensory symptom diagram (SSD), patient estimate of overall change, electrophysiologic testing of the median nerve (trans-carpal tunnel motor and sensory nerve conduction velocity and amplitude ratio), and carpal tunnel ultrasound imaging of the cross-sectional area of the median nerve and transverse carpal ligament length and bowing. All outcome measures were administered to participants before the first OMT session. Immediately after the first session, electrophysiologic testing of the median nerve and ultrasound imaging of the carpal tunnel were repeated. After 6 weeks of OMT, all outcome measures were readministered. RESULTS: Results of the BCTQ revealed statistically significant improvements in symptoms and function after 6 weeks of OMT (F=11.0; P=.004), and the improvements tended to be more pronounced on the treated side. The drop in SSD scores after 6 weeks of treatment was statistically significant (F=4.19; P=.0002). Patient estimate of overall improvement of symptoms was statistically significant for the treated side. No statistically significant changes in electrophysiologic function of the median nerve, cross-sectional area of the median nerve, or transverse carpal ligament bowing were observed. After treatment, the increase in transverse carpal ligament length was statistically significant, but no side-to-side difference was detected. CONCLUSION: Osteopathic manipulative treatment resulted in patient-perceived improvement in symptoms and function associated with CTS. However, median nerve function and morphology at the carpal tunnel did not change, possibly indicating a different mechanism by which OMT acted, such as central nervous system processes.

Cadaveric study of sacroiliac joint innervation: implications for diagnostic blocks and radiofrequency ablation.

BACKGROUND AND OBJECTIVES: Optimization of clinical outcomes of lateral branch radiofrequency ablation or blocks for sacroiliac joint (SIJ) pain requires precise nerve localization; however, there is a lack of comprehensive morphological studies. The objectives of this cadaveric study were to document SIJ innervation relative to bony landmarks in 3 dimensions and to identify reference points visible under ultrasound and fluoroscopy for optimal needle placement. METHODS: In 25 cadaveric hemipelves, L5-S4 lateral branches were exposed, digitized, and modeled in 3 dimensions. The models were used to compare innervation patterns between specimens and to quantify the distances of the nerves innervating the SIJ relative to the transverse sacral tubercles (TSTs) and posterior sacral foramina. Quadrants of origin of the nerves were recorded. RESULTS: The SIJ was innervated by the posterior sacral network: S1-S2 contributed in all specimens, S3 in 88%, L5 in 8%, and S4 in 4%. Most frequently, the lateral branch(es) emerged from the inferolateral S1, superolateral and inferolateral S2, and superolateral S3 quadrants. All TSTs were easily identifiable elevations that were used to landmark the nerves innervating the SIJ. The majority of branches of the posterior sacral network crossed the lateral sacral crest between TST1-3, with the greatest concentration between TST2-3. Only 3 specimens had a branch superior or inferior to these landmarks. CONCLUSIONS: Based on the innervation pattern and using bony landmarks identifiable under ultrasound and fluoroscopy, 2 radiofrequency ablation techniques were proposed. Further research is required to determine the accuracy and reliability of needle placement and to evaluate clinical outcomes.

Is it useful to repeat sacroiliac joint provocative tests post-block?

OBJECTIVE: To evaluate the diagnostic usefulness of repeating sacroiliac joint (SIJ) provocative tests post-block. DESIGN: Thirty-four patients with suspected unilateral mechanical SIJ pain participated. Eleven had confirmed SIJ origin pain (>79% pain relief with fluoroscopically guided comparative local anesthetic intra-articular blocks), whereas 23 were confirmed not to have SIJ origin pain (<80% pain relief with a single local anesthetic intra-articular block). Six SIJ provocative tests were performed 30 minutes prior to and following the blocks. Sensitivity, specificity, and likelihood ratios were calculated for subjects who had three or more positive pre-block SIJ provocative tests and for subjects in whom the majority of the SIJ provocative tests converted from positive to negative (normalized) post-block. RESULTS: The sensitivity, specificity, and likelihood ratios for subjects with three or more positive pre-block SIJ provocative tests were 0.82, 0.57, and 1.9, respectively (P=0.04). For subjects in whom the majority of the SIJ provocative tests normalized, the sensitivity was 0.89, specificity 0.30, and likelihood ratio 1.3 (P=0.3). CONCLUSION: Multiple positive pre-block SIJ provocative tests have diagnostic utility however post-block normalization of SIJ provocative tests does not.

Effect of hand warming on electrodiagnostic testing results and diagnosis in patients with suspected carpal tunnel syndrome.

UNLABELLED: Burnham RS, Burnham TR. Effect of hand warming on electrodiagnostic testing results and diagnosis in patients with suspected carpal tunnel syndrome. OBJECTIVES: To evaluate the effects of hand warming on electrodiagnostic (EDX) parameters of carpal tunnel syndrome (CTS). Specifically, to evaluate the type and magnitude of change in EDX values; to determine whether warming can change the EDX diagnosis of CTS and, if so, to determine whether specific EDX tests are more vulnerable to the effects of warming. DESIGN: Interventional before-after trial. SETTING: Community EDX laboratory. PARTICIPANTS: Consecutive patients (N=33) referred for EDX evaluation of suspected CTS. INTERVENTION: Each upper limb was tested at room temperature (average hand temperature, 31.9 degrees C) and retested after 20 minutes of heating pad warming (average hand temperature, 33.5 degrees C). MAIN OUTCOME MEASURES: Median and ulnar nerve motor and sensory latency, conduction velocity, and amplitude. RESULTS: Warming resulted in significantly faster transcarpal tunnel sensory and motor conduction (6%-10%), reduced median: ulnar sensory latency to digit 4 difference (23%), and reduced sensory nerve and compound motor action potential amplitude (10% and 13%, respectively). The changes resulted in 15% fewer limbs meeting the EDX conduction velocity criteria of CTS and 9% fewer by median: ulnar sensory latency to digit 4 difference. Waveform amplitudes became abnormally low after warming in 12% of limbs. CONCLUSIONS: Hand warming using a heating pad for 20 minutes increases median nerve transcarpal tunnel conduction velocity and reduces amplitude. These phenomena introduce potential sources of diagnostic error, particularly in borderline cases. Generally, within hand, between nerve, and within nerve comparison techniques are less susceptible to the conduction velocity effects of warming.

A prospective outcome study on the effects of facet joint radiofrequency denervation on pain, analgesic intake, disability, satisfaction, cost, and employment.

OBJECTIVE: To assess the effect of radiofrequency denervation (RFD) on patients with chronic low back pain (LBP) of facet joint origin. DESIGN: Prospective cohort study. SETTING: Interventional pain management program. PARTICIPANTS: Consecutive subjects (N=44; 101 facet joints) over 2 years with chronic refractory mechanical LBP of facet origin established by 2 local anesthetic blocks (medial branch +/- intra-articular) resulting in more than 50% pain relief. INTERVENTION: RFD of the symptomatic lumbar facet joints. MAIN OUTCOME MEASURES: Self-reported pain intensity, frequency, bothersomeness, analgesic intake, satisfaction, disability, back pain-related costs, and employment twice prior to and at 1, 3, 6, 9, and 12 months post-RFD. RESULTS: Post-RFD, significant improvements in pain, analgesic requirement, satisfaction, disability, and direct costs occurred. They peaked at 3 to 6 months and gradually diminished thereafter. Satisfaction with medical care and living with current symptoms improved similarly. Overall, satisfaction with the RFD procedure was high, and no complications were reported. CONCLUSIONS: RFD provides safe and significant short-term improvement in pain, analgesic requirements, function, satisfaction, and direct costs in patients with chronic LBP of facet origin.

Can topical anesthetic reduce the pain associated with diagnostic blocks of the lumbosacral spine?

OBJECTIVE: To evaluate the effectiveness of a topical local anesthetic cream (5% liposomal lidocaine) in reducing needle-induced pain in patients investigated for suspected zygapophysial (z-joint) or sacroiliac (SI) joint pain. DESIGN: Triple-blinded randomized controlled trial. Setting. Interventional fluoroscopy suite. STUDY POPULATION: Eighteen patients presenting with chronic mechanical low back pain. INTERVENTIONS: Thirty minutes prior to diagnostic z- or SI joint blocks, equivalent amounts of topical 5% liposomal lidocaine cream was applied to one side of the low back and a placebo cream to the other. The treatment side and injection order were randomized and the patient, injectionist, and data recorder were blinded. OUTCOME MEASURES: The subjects provided numerical rating scores of pain intensity immediately following each phase of the injection (skin penetration, deep, overall). Scores were analyzed with dependent t-tests. RESULTS: The injection associated pain was significantly less during the skin penetration phase on the side of the local anesthetic vs the placebo cream (3.0/10 vs 4.2/10; P = 0.002). No significant differences were found during the deep phase or for the injection procedure overall. CONCLUSIONS: Five percent liposomal lidocaine cream significantly reduces the pain associated with the skin penetration phase of lumbosacral diagnostic blocks but does not change the pain associated with the deep phase or the injection procedure overall. Its usefulness for this application is questionable.

A clinical tool for office assessment of lumbar spine stabilization endurance: prone and supine bridge maneuvers.

OBJECTIVE: : To assess the validity and reliability of an office-based surrogate measure of lumbar spine-stabilization endurance capability; to establish norms and reliability in an asymptomatic group; and to compare their measures with those from a group of chronic mechanical low-back pain patients. DESIGN: : Eight healthy subjects participated in the tool-validation portion of the study that consisted of surface electromyographic (EMG) measurements of core muscle activation during prone and supine bridging. Subsequently, normative and test-retest reliability measures of prone and supine bridging duration were recorded from 43 subjects without back pain and were compared with those of 32 subjects with chronic mechanical low-back pain. RESULTS: : Surface EMG indicated significantly preferential activation of anterior core muscles during prone bridging and posterior core muscles during supine bridging. Mean bridge durations for subjects without back pain were 72.5 +/- 32.6 (mean +/- SD) secs in prone and 170.4 +/- 42.5 secs in supine. They were significantly less in subjects with back pain: 28.3 +/- 26.8 secs in prone and 76.7 +/- 48.9 secs in supine. Test-retest reliability using Pearson's correlation for prone and supine bridging was 0.78 and 0.84, respectively. CONCLUSIONS: : Bridging maneuvers seem to be practical, reliable, and valid methods of reflecting lumbar spine-stabilization endurance capability. Prone bridging preferentially challenges core flexors, whereas supine bridging recruits primarily the core extensors; both are compromised in patients with low-back pain.

An alternate method of radiofrequency neurotomy of the sacroiliac joint: a pilot study of the effect on pain, function, and satisfaction.

BACKGROUND AND OBJECTIVES: The sacroiliac joint (SIJ) can be a source of chronic refractory mechanical spine pain. Few previous studies have described radiofrequency (RF) sensory denervation of the SIJ; results have been inconsistent and technically demanding. This uncontrolled, prospective, cohort study evaluates the effects of an innovative method of RF ablation of the posterior sensory nerves of the SIJ on pain, analgesic use, disability, and satisfaction of patients suffering with chronic mechanical SIJ pain. METHODS: Nine subjects with SIJ pain, confirmed by a local anesthetic joint block, were studied. Subjects were treated with a series of RF strip lesions performed adjacent to the lateral dorsal foraminal aperture plus conventional monopolar lesioning at the L5 dorsal ramus. Each subject completed a questionnaire twice before and at 1, 3, 6, 9, and 12 months after the procedure. The questionnaire evaluated pain intensity and frequency, analgesic intake, disability, satisfaction (with current pain level and the RF procedure), and procedure complications. Data were analyzed by using linear mixed model analysis. RESULTS: After the procedure, significant reductions of back and leg pain frequency and severity, analgesic intake, and dissatisfaction with their current level of pain occurred. Complications were minimal. Overall, 8 of 9 subjects were satisfied with the procedure. CONCLUSIONS: RF sensory ablation of the SIJ using bipolar strip lesions is a technically uncomplicated and low-risk procedure. The resulting effects on pain, disability, and satisfaction are promising. Further evaluation of this technique, including randomized controlled trials, is recommended.

Three types of skin-surface thermometers: a comparison of reliability, validity, and responsiveness.

OBJECTIVE: To compare the reliability, validity, and responsiveness of a thermistor thermometer (thermistor) and two different infrared thermometers (one designed to measure tympanic temperature and one for skin temperature). DESIGN: Reliability and validity were evaluated by making two separate measurements from the skin at identical spots of each hand, forearm, shoulder, thigh, shin, and foot in 17 healthy subjects. Intramuscular temperature was recorded at the hand and shin sites. Test-retest reliability was calculated using intraclass correlation for each instrument. Pearson correlation assessed the relationship between the skin and intramuscular temperatures at the hand and shin sites (validity). Each instrument's ability to measure temperature change (responsiveness) was assessed by measuring skin temperatures serially from 17 limbs of ten patients with complex regional pain syndrome undergoing intravenous regional sympathetic blockade. Responsiveness index values were calculated. RESULTS: Reliability was strong and similar for each device (intraclass correlation: thermistor = 0.96, tympanic = 0.96, skin = 0.97), as was validity (r: thermistor = 0.90, tympanic = 0.92, skin = 0.92). Responsiveness was marginally better for the infrared skin device (responsiveness index: skin = 4.2, tympanic = 3.6, thermistor = 3.6). CONCLUSIONS: For the purposes of clinical electrodiagnostic laboratory and other physiatry applications, the performance of the infrared thermometers is equal to or superior to that of the traditionally used thermistor. All three devices are highly reliable and valid, whereas the infrared skin device is slightly more responsive. Infrared thermometers have the advantage of being quicker to operate and more portable.

Botulinum toxin A versus bupivacaine trigger point injections for the treatment of myofascial pain syndrome: a randomised double blind crossover study.

The treatment of myofascial pain syndrome (MPS) is diverse and includes trigger point injections of various substances including local anesthetics, steroids and Botulinum toxin A (BTX A). The purpose of this study was to compare the effectiveness of trigger point injections using BTX A versus bupivacaine, both in combination with a home-based rehabilitation program. To be enrolled, subjects first had to demonstrate responsiveness to bupivacaine trigger point injection. In this single center, double blind, randomized, cross-over trial, 18 patients with MPS received trigger point injections of either 25 units Botulinum toxin A or 0.5 ml of 0.5% bupivacaine per trigger point. A maximum of eight trigger points were injected per subject. Subjects were followed until their pain returned to 75% or more of their pre-injection pain for two consecutive weeks, after which there was a 2 week wash-out period. The subjects then crossed over and had the same trigger points injected with the other agent. All subjects participated in a home exercise program involving static stretches of the affected muscles. Both treatments were effective in reducing pain when compared to baseline (P=0.0067). There was, however, no significant difference between the BTX A and 0.5% bupivacaine groups in duration or magnitude of pain relief, function, satisfaction or cost of care (cost of injectate excluded). Considering the high cost of BTX A, bupivacaine is deemed a more cost-effective injectate for MPS.

An assessment of wrist splint and glove use on wheeling kinematics.

OBJECTIVE: The purpose of this investigation was to assess whether glove and/or splint use could effectively reduce hyperextension at the wrist during wheelchair propulsion, thus potentially reducing the conditions predisposing to median nerve dysfunction, and to evaluate the overall effects of these interventions on wheeling mechanics. DESIGN: This investigation used a randomized experimental design. BACKGROUND: The upper extremities are used for weight bearing and propulsion by individuals who are wheelchair dependent. High intracarpal pressures created by hyper-extension of the wrist and repetitive high force stresses of the hands against the wheel are suggested causes of median nerve dysfunction. METHODS: The wheeling performances of 13 subjects were recorded using two SVHS video-cameras under four different glove/splint conditions. Each subject was analysed on two wheeling cycles under all four conditions. Wrist and elbow angles, joint range of motions and wheeling speed were determined. Data were analysed using a one-way analysis of variance (ANOVA), followed by Scheffé post-hoc comparisons at the 0.05 level of significance. RESULTS: The splint and the glove/splint combination significantly reduced wrist extension during wheeling, but did not alter elbow motion or maximal wheeling speed. CONCLUSIONS: Hand and wrist protection in the form of a splint or glove/splint combination can reduce hyperextension of the wrist, and therefore may be of functional value for wheelchair users. This form of protection may therefore be useful in various orthopedic conditions of the wrist or hand commonly seen in wheelchair-dependent individuals without seriously interfering with wheeling quality.