Mesenchymal stem cells for chronic knee pain secondary to osteoarthritis: A systematic review and meta-analysis of randomized trials.

OBJECTIVE: To assess the effectiveness of mesenchymal stem cells (MSCs) for chronic knee pain secondary to osteoarthritis (OA). METHODS: We searched MEDLINE, EMBASE, CINAHL, and Cochrane Central to September 2023 for trials that (1) enrolled patients with chronic pain associated with knee OA, and (2) randomized them to MSC therapy vs. placebo or usual care. We performed random-effects meta-analysis and used Grading of Recommendations, Assessment, Development, and Evaluation to assess the certainty of evidence. RESULTS: We included 16 trials (807 participants). At 3-6 months, MSC therapy probably results in little to no difference in pain relief (weighted mean difference [WMD] -0.74 cm on a 10 cm visual analog scale [VAS], 95% confidence interval [95%CI] -1.16 to -0.33; minimally important difference [MID] 1.5 cm) or physical functioning (WMD 2.23 points on 100-point 36-item Short Form Survey (SF-36) physical functioning subscale, 95%CI -0.97 to 5.43; MID 10-points; both moderate certainty). At 12 months, injection of MSCs probably results in little to no difference in pain (WMD -0.73 cm on a 10 cm VAS, 95%CI -1.69 to 0.24; moderate certainty) and may improve physical functioning (WMD 19.36 points on 100-point SF-36 PF subscale, 95%CI -0.19 to 38.9; low certainty). MSC therapy may increase risk of any adverse events (risk ratio [RR] 2.67, 95%CI 1.19 to 5.99; low certainty) and pain and swelling of the knee joint (RR 1.58, 95%CI 1.04 to 2.38; low certainty). CONCLUSIONS: Intra-articular injection of MSCs for chronic knee pain associated with OA probably provides little to no improvement in pain or physical function.

Can ultrasound-guided medial branch blocks be used to select patients for cervical facet joint radiofrequency neurotomy? - A matched retrospective cohort validation study.

BACKGROUND: Medial branch blocks are used to select patients for cervical facet joint radiofrequency neurotomy (CRFN). Blocks are typically performed under fluoroscopic guidance (FLB). The validity of ultrasound guided blocks (USB) is not well established. No prior research has compared cervical USB versus FLB validity using CRFN outcome as the criterion standard. OBJECTIVE: To evaluate cervical USB versus FLB validity using CRFN outcome as the criterion standard. METHODS: Demographic and outcome data were extracted from the EMRs of two affiliated MSK pain management clinics for all patients between 2015 and 2023 inclusive who had cervical USB leading to CRFN. CRFN outcomes of each USB patient were compared to a matched FLB patient from the RFN outcome database of the same clinics. Matching variables included patient age, sex, pain duration, diagnostics/prognostic block paradigm and CRFN number. Each patient completed a NRS pain score and Pain Disability Quality-of-Life Questionnaire (PDQQ) just before and 3-months post-CRFN. At repeat CRFN, patients provided a retrospective estimate of the duration and average magnitude (%) of relief following the CRFN. RESULTS: USB and FLB groups were comprised of 27 patients (58 RFNs) and 38 patients (58 RFNs) respectively. Post RFN NRS pain severity and PDQQ-S scores demonstrated comparable (p > 0.05) absolute improvements, proportion of patients achieving ≥50% improvement, and attainment of MCID. Retrospective estimates of pain relief magnitude and duration were also comparable. CONCLUSIONS: This study finds cervical USB and FLB to be comparably valid as defined by their ability to predict CRFN outcome. Within the limitations of operator competence, USB can be used to select patients for CRFN.

The Effect of Knee Height Asymmetry on Gait Biomechanics.

BACKGROUND: Though the primary goal for limb length discrepancy (LLD) management is to equalize the leg lengths, symmetry between corresponding long bones is usually not achieved, leading to knee height asymmetry (KHA). To date, there is minimal information on what effect KHA has on gait biomechanics and joint loading. Thus, the purpose of this study is to determine the impact of KHA on gait biomechanics. METHODS: Seventeen subjects with KHA after limb equalizing surgery and 10 healthy controls were enrolled. Subjects participated in 3D gait analysis collected using self-selected speed. Lower extremity kinematics, kinetics, work generated/absorbed, and total work were calculated. Standing lower limb x-rays and scanograms were used to measure LLD and calculate the tibia-to-femur (TF) ratio for each limb. Two sample t tests were used to compare differences in standing LLD, TF ratio, and work between groups. Bivariate correlation using Pearson correlation coefficients was conducted between TF ratio and total mechanical work, as well as between knee height asymmetry indices and total work asymmetry (α=0.05). RESULTS: Among participants, there were no differences between LLD; however, there were differences between TF ratio and knee height asymmetry. We found a nonsignificant relationship between TF ratio and total mechanical work for individual lower extremities. Therefore, the length of individual bones (TF ratio) relative to each other within the individual lower extremity was not associated with the amount of work produced. However, when a difference exists between sides (asymmetry, ie, TF ratio asymmetry), there were associated differences in work (work asymmetry) produced between sides (r=0.54, P=0.003). In other words, greater knee height asymmetry between limbs resulted in more asymmetrical mechanical work during walking. CONCLUSIONS: These findings may have implications for the management of LLD. Asymmetrical total mechanical work could lead to atypical joint loading during gait. Surgeons may want to consider prioritizing achieving knee height symmetry as a postoperative goal when correcting limb length discrepancy. LEVEL OF EVIDENCE: Level III, Case Control Study.

Radiofrequency Ablation of the Infrapatellar Branch of the Saphenous Nerve for the Treatment of Chronic Anterior Inferomedial Knee Pain.

INTRO: Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment for chronic knee pain related to osteoarthritis. It is often utilized when conservative management has failed and patients wish to avoid arthroplasty, are poor surgical candidates due to comorbid medical conditions, or in those suffering from persistent pain after arthroplasty. The classic targets for GNRFA include the superior lateral genicular nerve, superior medial genicular nerve, and inferior medial genicular nerve but multiple anatomic studies have demonstrated additional sensory innervation to the knee. OBJECTIVE: In this research article, we propose an image-guided technique that can safely target the infrapatellar branch of the saphenous nerve which also provides sensory innervation to the anterior capsule. PROPOSAL: The proposed technique includes variations for conventional bipolar radiofrequency ablation, cooled radiofrequency ablation, dual-tined bipolar radiofrequency ablation, and monopolar radiofrequency ablation using a long axis approach. The described technique is based on updated anatomic studies and takes into account safety concerns such as thermal risk to the skin and/or pes anserine tendons and breaching of the synovial cavity. CONCLUSION: Future clinical research should be performed to confirm the safety and effectiveness of this specific approach.

Medication management of chronic pain: A comparison of 2 care delivery models.

BACKGROUND: The prevalence of chronic pain is high and increasing. Medication management is an important component of chronic pain management. There is a shortage of physicians who are available and comfortable providing this service. In Alberta, pharmacists have been granted an advanced scope of practice. Given this empowerment, their availability, training and skill set, pharmacists are well positioned to play an expanded role in the medication management of chronic pain sufferers. OBJECTIVE: To compare the effectiveness and cost of a physician-only vs a pharmacist-physician team model of medication management for chronic nonmalignant pain sufferers. METHOD: Data was analyzed for 89 patients who had received exclusively medication management at a rural Alberta multidisciplinary clinic. 56 were managed by a sole physician. 33 were managed by a team (pharmacist + physician). In the team model, the physician did the medical assessment, diagnosis, and established a treatment plan in consultation with the patient and pharmacist. The pharmacist then provided the ongoing follow-up including education, dose titration and side effect management and consulted with the physician as needed. Change in pain (Numerical Rating Scale) and disability (Pain Interference Questionnaire) over the course of treatment were recorded. The treatment duration and number of visits were used to calculate cost of care. RESULTS: Both models of medication management resulted in significant and comparable improvements in pain, disability and patient perception of medication effectiveness. Patients in the physician-only group were seen more frequently and at a greater cost. The pharmacist-physician team approach was markedly more cost-effective, and patients expressed a high level of satisfaction with their medication management. CONCLUSIONS: The pharmacist-physician team model of medication management results in significant reductions of pain and disability for chronic nonmalignant pain sufferers at a reduced cost and is well accepted by patients.

Derivation of a clinical decision rule for a bone marrow aspirate concentrate injection in knee osteoarthritis.

Aim: To develop a simple clinical decision rule (CDR) to identify people with knee osteoarthritis who are likely or unlikely to benefit from bone marrow aspirate concentrate (BMAC) injection. Materials & methods: A total of 92 people with clinical and radiographic evidence of refractory knee osteoarthritis received a single intra-articular (IA) BMAC injection. Multiple logistic regression analysis was used to determine which combination of risk factors predicted BMAC responsiveness. A responder was defined as a person whose knee pain improved more than 15% from baseline 6 months post procedure. Results: The CDR demonstrated that those with lower pain levels, or high pain levels with previous surgery, could be predicted to benefit from a single IA BMAC injection. Conclusion: A simple CDR containing three variables predicted responsiveness to a single IA knee BMAC injection with high accuracy. Further validation of the CDR is required prior to routine use in clinical practice.

People with knee osteoarthritis who do not improve with exercise and medicine lack effective long-term treatment options apart from total knee replacement. Although total knee replacement provides effective outcomes in most people, not all people are candidates and not all people respond. Thus, other safe and effective treatment options are required. Bone marrow aspirate concentrate (BMAC) is a regenerative medicine treatment that has demonstrated success in people with chronic knee osteoarthritis. However, it is unclear which people do or do not respond to BMAC. This study investigated factors that predicted a successful response to a single injection of BMAC 6 months post injection. Those with lower initial pain levels (<7/10), or high pain levels with previous surgery, could be predicted to benefit from a single BMAC injection.

Assessing Leg Length and Offset in Anterior Total Hip Arthroplasty: Overlay Versus AP Pelvis Intraoperative Radiographic Techniques: A Retrospective Cohort Study.

INTRODUCTION: Two intraoperative radiographic techniques to determine leg length and offset during anterior total hip arthroplasty (THA) are the AP pelvis and overlay techniques. The AP pelvis method measures LLDs and offset using AP fluoroscopic images, whereas the overlay method uses printed images of the native and replaced hips. The purpose of this study was to compare these techniques regarding clinical and radiographic LLD and offset discrepancies. METHODS: Patients of a single surgeon at two hospitals from September 2017 to January 2021 were retrospectively reviewed. Clinically detectable LLD was recorded. Radiographic measurements were obtained from preoperative and postoperative radiographs. LLD was determined based on the vertical distance between the lesser trochanters and the ischial tuberosities. Total offset was measured using a combination of femoral and medial offset. The Student t-test, Fisher exact test, and Wilcoxon rank sum tests were used for statistical analysis. RESULTS: Seventy-one procedures were done using the overlay technique and 61 used for the AP pelvis technique. No significant differences were observed in mean postoperative LLD (2.66 versus 2.88 mm, P = 0.66) and mean postoperative offset discrepancy (5.37 versus 4.21 mm, P = 0.143) between the overlay versus AP pelvis groups. The mean preoperative to postoperative absolute difference in offset was less than 5 mm in both groups. Clinically detectable LLD was noted in six of 71 patients in the overlay group and one of 61 in the AP pelvis group (P = 0.123). CONCLUSION: No notable differences were observed in intraoperative leg length and offset discrepancies during direct anterior THA between the AP pelvis and overlay techniques, suggesting they are equally effective in determining LLD and offset intraoperatively. The choice of technique to use anterior THA should be based primarily on the surgeon's preference, comfort, and available resources.

Outcomes of Total Knee and Hip Arthroplasty in Patients With Perioperative Thrombocytopenia.

BACKGROUND: Thrombocytopenia is an abnormally low level of blood platelets (less than 150,000/mL) resulting in an increased risk for bleeding. Typically, patients with platelet levels below 50,000/mL should delay arthroplasty or be transfused with platelets before surgery. However, existing studies are mixed regarding the effects of more moderate thrombocytopenia in terms of total knee and hip arthroplasty outcomes. METHODS: This level III retrospective chart review examined the effects of different severities of preoperative thrombocytopenia on length of hospitalization, readmission, and transfusion rates in 5,617 primary total knee and hip arthroplasties at one tertiary academic medical center. Preoperative platelet levels were sectioned into clinically relevant groups and compared with clinical outcomes using univariable and multivariable models. RESULTS: On univariate analysis, having platelet levels of <100,000/mL and 100 to 149,000/mL was associated with a longer length of stay. However, after controlling individual demographics, there was no association between platelet levels and length of stay, nor with 30-day readmission. Finally, on univariate analysis, patients with platelet levels of <100,000/mL and 100 to 149,000/mL were more likely to have a blood transfusion, which remained true for those with <100,000/mL after controlling for individual demographics. CONCLUSIONS: Total hip and total knee arthroplasty are safe in patients with varying platelet levels and not associated with increased length of stay or 30-day readmission. However, patients with more severe thrombocytopenia are more likely to receive red blood cell transfusions than patients with milder thrombocytopenia.

The Association Between Sleep Disturbance and Health Outcomes in Chronic Whiplash-associated Disorders: A Series of Mediation Analyses.

OBJECTIVES: To investigate the association between sleep disturbance and clinical features of chronic whiplash-associated disorders (WAD). We also aimed to use a bootstrapped mediation analysis approach to systematically examine both direct and indirect pathways by which sleep disturbance may affect chronic pain and functional status. MATERIALS AND METHODS: One hundred sixty-five people (63% female) with chronic WAD and not taking medications for sleep disturbance completed questionnaires evaluating sleep disturbance, pain intensity, pain interference, disability, physical and mental health quality of life, stress, anxiety, depression, pain catastrophizing, and posttraumatic stress severity. RESULTS: Greater sleep disturbance was associated with increased duration of symptoms, higher levels of pain and disability, higher levels of emotional distress and pain catastrophizing, and functional impairment (reduced health-related quality of life). Mediation analyses demonstrated that sleep disturbance influenced chronic pain intensity and interference through both direct and indirect associations inclusive of stress, anxiety, and pain catastrophizing. Similarly, sleep disturbance was associated with higher levels of disability and poor health-related quality of life, both directly and also through its negative association with pain intensity and interference. DISCUSSION: Sleep disturbance in chronic WAD was associated with worse health outcomes and demonstrated both direct and indirect effects on both chronic pain and function.

Prospective Within Subject Comparison of Fluoroscopically Guided Lumbosacral Facet Joint Radiofrequency Ablation Using a Multi-Tined (Trident) Versus Conventional Monopolar Cannula.

BACKGROUND: Radiofrequency ablation (RFA) for the lumbar facet joints has demonstrated efficacy in the management of chronic low back pain. The traditional technique uses a conventional monopolar (CM) cannula placed parallel to the putative nerve to produce a thermal lesion resulting in pain relief of the facet joints. A new multi-tined (MT) cannula has come onto the market that allows targeting the putative nerve using a perpendicular to the nerve approach. OBJECTIVES: This study describes the technique using the MT cannula and compares its efficacy and procedural characteristics to the CM cannula. STUDY DESIGN: This is a pre-post crossover observational study. METHODS: Fifty-one patients were recruited between June 2015 and March 2020. Each patient underwent 2 fluoroscopic guided lumbosacral RFA procedures on 2 separate occasions at the same facet joints, using the CM and MT cannula consecutively. The primary outcome measure was change in pain on the 11-point numeric rating scale (NRS). Secondary outcome measures included change in Pain Disability Quality of Life Questionnaire (PDQQ) score, duration and magnitude of pain relief, local anesthetic use, adverse events, procedural and fluoroscopy exposure time, and radiation dose. RESULTS: There were no statistically significant difference between CM versus MT canula in terms of absolute (4.0 versus 4.3) and relative (52% versus 57%) change in NRS (P = 0.99) and PDQQ (22 versus 22, P = 0.61) at 3 months, or overall pain magnitude (71% versus 72%, P = 0.96) and duration of relief (8.7 months versus 8.4 months, P = 0.68). The procedures using the MT cannula were completed faster (37.6 minutes versus 31.1 minutes, P < 0.001) and required less local anesthetic (15.8 mL versus 11.0 mL, P < 0.001) and radiation dose (41.5 mGy versus 30.2 mGy, P = 0.05). No adverse events were observed with either cannula. LIMITATIONS: This was an observational study at a single center with the proceduralist not blinded to the intervention. CONCLUSION: This study demonstrated that the outcomes in terms of pain, disability, quality of life, adverse events, and fluoroscopy exposure time were equivalent between the 2 cannulae. However, RFA using the MT cannula was faster to perform and involved less local anesthetic and radiation.

Artificial intelligence accurately identifies total hip arthroplasty implants: a tool for revision surgery.

BACKGROUND: A critical part in preoperative planning for revision arthroplasty surgery involves the identification of the failed implant. Using a predictive artificial neural network (ANN) model, the objectives of this study were: (1) to develop a machine-learning algorithm using operative big data to identify an implant from a radiograph; and (2) to compare algorithms that optimise accuracy in a timely fashion. METHODS: Using 2116 postoperative anteroposterior (AP) hip radiographs of total hip arthroplasties from 2002 to 2019, 10 artificial neural networks were modeled and trained to classify the radiograph according to the femoral stem implanted. Stem brand and model was confirmed with 1594 operative reports. Model performance was determined by classification accuracy toward a random 706 AP hip radiographs, and again on a consecutive series of 324 radiographs prospectively collected over 2019. RESULTS: The Dense-Net 201 architecture outperformed all others with 100.00% accuracy in training data, 95.15% accuracy on validation data, and 91.16% accuracy in the unique prospective series of patients. This outperformed all other models on the validation (p < 0.0001) and novel series (p < 0.0001). The convolutional neural network also displayed the probability (confidence) of the femoral stem classification for any input radiograph. This neural network averaged a runtime of 0.96 (SD 0.02) seconds for an iPhone 6 to calculate from a given radiograph when converted to an application. CONCLUSIONS: Neural networks offer a useful adjunct to the surgeon in preoperative identification of the prior implant.

Evaluation of an Ultrasound-Assisted Longitudinal Axis Lateral Crest Approach to Radiofrequency Ablation of the Sacroiliac Joint.

OBJECTIVE: The aim of the study was to evaluate the effectiveness and procedural characteristics of a novel, ultrasound/fluoroscopically guided technique (longitudinal axis sacroiliac joint radiofrequency ablation) for sacroiliac joint denervation. DESIGN: A single-arm cohort with historical cohort comparison was used in this study. METHODS: Thirty-seven participants underwent longitudinal axis sacroiliac joint radiofrequency ablation after 50% or more pain reduction after diagnostic dual-block criterion. Outcomes were the proportion of participants with 50% or more pain reduction and mean Pain Disability Quality of Life Questionnaire change. Subanalysis included longitudinal axis sacroiliac joint radiofrequency ablation procedural and fluoroscopy times compared with participants previously treated with palisade radiofrequency ablation technique. RESULTS: Primary outcome worst case analysis demonstrated a responder rate of 64.9% (95% confidence interval = 48.8%-78.2%) and 59.5% (95% confidence interval = 43.5%-73.7%) at 3 and 6 mos. There was significant decrease in mean Pain Disability Quality of Life Questionnaire at 3 (45.6 ± 9.5 to 21.4 ± 16.0, P < 0.001) and 6 mos (45.6 ± 9.5 to 23.0 ± 16.5, P < 0.001). Longitudinal axis sacroiliac joint radiofrequency ablation required more procedure time than the palisade technique (38.2 ± 7.9 vs. 32.1 ± 6.9 mins, P = 0.031) but less fluoroscopy time (35.0 ± 11.8 vs. 57.6 ± 16.8 secs, P < 0.001). CONCLUSIONS: Longitudinal axis sacroiliac joint radiofrequency ablation resulted in improvement in pain, disability, and quality of life at 3 and 6 mos. Compared with the palisade technique, longitudinal axis sacroiliac joint radiofrequency ablation required greater procedure time but less fluoroscopy time.

Defining the Learning Curve of Anterior Total Hip Arthroplasty After Fellowship-specific Training.

PURPOSE: To investigate the learning curve associated with performing direct anterior total hip arthroplasty (THA) immediately after fellowship training in this approach. METHODS: This was a multicenter, retrospective study that collected data on all direct anterior THAs performed by four fellowship-trained arthroplasty surgeons in their first year of practice. Demographic data, surgical time, blood loss, surgical complications, and medical complications were recorded. Regression models were created to evaluate the outcomes of interest. A generalized linear mixed model was used to estimate the effect of the number of THA procedures performed, a proxy for surgical experience with this procedure, on the variables of interest. RESULTS: A total of 286 patients undergoing direct anterior THA were included in this study. A decrease in surgical complications after approximately 40 cases and a decrease in medical complications at 25 to 50 cases were observed. Both surgical time and blood loss showed no learning curve. CONCLUSION: Extensive training with a direct anterior approach during fellowship minimizes the learning curve for blood loss and surgical time, but it continues to exist regarding perioperative surgical and medical complications. Recent fellowship graduates should be cautious and expect a learning curve of around 40 cases before complication rates begin to normalize.

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.

The safety and effectiveness of bone marrow concentrate injection for knee and hip osteoarthritis: a Canadian cohort.

Aim: Describe the safety and effectiveness of intra-articular bone marrow concentrate (BMC) injection to treat knee and/or hip osteoarthritis (OA) in a Canadian cohort. Materials & methods: A total of 112 patients with refractory OA received a single intra-articular injection of BMC into their knee(s) and/or hip(s). Pain, disability and quality of life were prospectively assessed prior to and 3, 6 and 12 months post-injection. Results: Outcome scores were significantly improved at all time points post-BMC injection with maximal improvement observed at 3-6 months. Improvements were unrelated to patient age, sex or radiographic OA severity. The complication rate was <2%. Interpretation: In this Canadian cohort, knee/hip OA treated with a single BMC injection resulted in significant improvements in pain, disability and quality of life and a low complication rate.

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.

Radiofrequency sensory ablation as a treatment for symptomatic unilateral lumbosacral junction pseudarticulation (Bertolotti's syndrome): a case report.

OBJECTIVE: Describe the clinical presentation, diagnostic evaluation, and successful treatment of a case of symptomatic unilateral lumbosacral junction pseudarticulation using a novel radiofrequency nerve ablation technique. CASE: A 56-year-old female patient who had suffered with low back and right upper buttock pain for 16 years experienced incomplete relief with L4/5 facet joint radiofrequency ablation. She was found to have an elongated right L5 transverse process that articulated with the sacral ala (Bertolotti's syndrome). Fluoroscopically guided local anesthetic/corticosteroid injection into the pseudarthrosis eliminated her residual right buttock pain for the duration of the local anesthetic only. Complete pain relief was achieved by injecting local anesthetic circumferentially around the posterior pseudarthrosis articular margin. Accordingly, bipolar radiofrequency strip thermal lesions were created at the same locations. Complete pain relief and full restoration of function was achieved for 16 months postprocedure. CONCLUSION: This case report describes a novel radiofrequency technique for treating symptomatic lumbosacral junction pseudarticulation that warrants further evaluation.

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.

The effect of repeated zygapophysial joint radiofrequency neurotomy on pain, disability, and improvement duration.

OBJECTIVE: To assess the effectiveness of repeated radiofrequency neurotomy (RFN) on pain, disability, and treatment effect duration. PATIENTS: One hundred-four patients who underwent repeat RFN for chronic neck or back pain were prospectively followed using a Pain Disability Questionnaire-Spine (PDQ-S). Complete data sets were available for 73, 73, and 36 patients for the 1st, 2nd, and 3rd RFN, respectively. RESULTS: Pain intensity, pain frequency, and patient-specific disability measures were significantly improved post-initial, second, and third RFN. Moreover, there was no statistically significant difference among the PDQ-S scores post-RFN 1, 2, and 3. There was no statistical significance between the duration of pain relief post-RFN 1 and pain relief post-RFD 2. CONCLUSION: Repeated cervical and lumbar RFN reduces pain and disability with equal effectiveness for approximately 10 months in patients with facetogenic chronic neck and back pain.