Objectives. Local corticosteroid infiltration is a common practice of treatment for lateral epicondylitis. In recent studies no statistically significant or clinically relevant results in favour of corticosteroid injections were found. The injection of autologous blood has been reported to be effective for both intermediate and long-term outcomes. It is hypothesised that blood contains growth factors, which induce the healing cascade. Methods. A total of 60 patients were included in this prospective randomised study: 30 patients received 2 ml autologous blood drawn from contralateral upper limb vein + 1 ml 0.5% bupivacaine, and 30 patients received 2 ml local corticosteroid + 1 ml 0.5% bupivacaine at the lateral epicondyle. Outcome was measured using a pain score and Nirschl staging of lateral epicondylitis. Follow-up was continued for total of six months, with assessment at one week, four weeks, 12 weeks and six months. Results. The corticosteroid injection group showed a statistically significant decrease in pain compared with autologous blood injection group in both visual analogue scale (VAS) and Nirschl stage at one week (both p < 0.001) and at four weeks (p = 0.002 and p = 0.018, respectively). At the 12-week and six-month follow-up, autologous blood injection group showed statistically significant decrease in pain compared with corticosteroid injection group (12 weeks: VAS p = 0.013 and Nirschl stage p = 0.018; six months: VAS p = 0.006 and Nirschl p = 0.006). At the six-month final follow-up, a total of 14 patients (47%) in the corticosteroid injection group and 27 patients (90%) in autologous blood injection group were completely relieved of pain. Conclusions. Autologous blood injection is efficient compared with corticosteroid injection, with less side-effects and minimum recurrence rate

Aims. Steroid injections are used for subacromial pain syndrome and can be administered via the anterolateral or posterior approach to the subacromial space. It is not currently known which approach is superior in terms of improving clinical symptoms and function. This is the protocol for a randomized controlled trial (RCT) to compare the clinical effectiveness of a steroid injection given via the anterolateral or the posterior approach to the subacromial space. Methods. The Subacromial Approach Injection Trial (SAInT) study is a single-centre, parallel, two-arm RCT. Participants will be allocated on a 1:1 basis to a subacromial steroid injection via either the anterolateral or the posterior approach to the subacromial space. Participants in both trial arms will then receive physiotherapy as standard of care for subacromial pain syndrome. The primary analysis will compare the change in Oxford Shoulder Score (OSS) at three months after injection. Secondary outcomes include the change in OSS at six and 12 months, as well as the Pain Numeric Rating Scale (0 = no pain, 10 = worst pain), Disabilities of Arm, Shoulder and Hand questionnaire (DASH), and 36-Item Short-Form Health Survey (SF-36) (RAND) at three months, six months, and one year after injection. Assessment of pain experienced during the injection will also be determined. A minimum of 86 patients will be recruited to obtain an 80% power to detect a minimally important difference of six points on the OSS change between the groups at three months after injection. Conclusion. The results of this trial will demonstrate if there is a difference in shoulder pain and function after a subacromial space steroid injection between the anterolateral versus posterior approach in patients with subacromial pain syndrome. This will help to guide treatment for patients with subacromial pain syndrome. Cite this article: Bone Jt Open 2024;5(9):729–735

Aims. Frozen shoulder is a common, painful condition that results in impairment of function. Corticosteroid injections are commonly used for frozen shoulder and can be given as glenohumeral joint (GHJ) injection or suprascapular nerve block (SSNB). Both injection types have been shown to significantly improve shoulder pain and range of motion. It is not currently known which is superior in terms of relieving patients’ symptoms. This is the protocol for a randomized clinical trial to investigate the clinical effectiveness of corticosteroid injection given as either a GHJ injection or SSNB. Methods. The Therapeutic Injections For Frozen Shoulder (TIFFS) study is a single centre, parallel, two-arm, randomized clinical trial. Participants will be allocated on a 1:1 basis to either a GHJ corticosteroid injection or SSNB. Participants in both trial arms will then receive physiotherapy as normal for frozen shoulder. The primary analysis will compare the Oxford Shoulder Score (OSS) at three months after injection. Secondary outcomes include OSS at six and 12 months, range of shoulder movement at three months, and Numeric Pain Rating Scale, abbreviated Disabilities of Arm, Shoulder and Hand score, and EuroQol five-level five-dimension health index at three months, six months, and one year after injection. A minimum of 40 patients will be recruited to obtain 80% power to detect a minimally important difference of ten points on the OSS between the groups at three months after injection. The study is registered under ClinicalTrials.gov with the identifier NCT04965376. Conclusion. The results of this trial will demonstrate if there is a difference in shoulder pain and function after GHJ injection or SSNB in patients with frozen shoulder. This will help provide effective treatment to patients with frozen shoulder. Cite this article: Bone Jt Open 2023;4(3):205–209

Aims. To describe the incidence of adverse clinical outcomes related to COVID-19 infection following corticosteroid injections (CSI) during the COVID-19 pandemic. To describe the incidence of positive SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) testing, positive SARS-COV2 IgG antibody testing or positive imaging findings following CSI at our institution during the COVID-19 pandemic. Methods. A retrospective observational study was undertaken of consecutive patients who had CSI in our local hospitals between 1 February and 30June 2020. Electronic patient medical records (EPR) and radiology information system (RIS) database were reviewed. SARS-CoV-2 RT-PCR testing, SARS-COV2 IgG antibody testing, radiological investigations, patient management, and clinical outcomes were recorded. Lung findings were categorized according to the British Society of Thoracic Imaging (BSTI) guidelines. Reference was made to the incidence of lab-confirmed COVID-19 cases in our region. Results. Overall, 1,656 lab-confirmed COVID-19 cases were identified in our upper tier local authority (UTLA), a rate of 306.6 per 100,000, as of 30June 2020. A total of 504 CSI injections were performed on 443 patients between 1 February and 30June 2020. A total of 11 RT-PCR tests were performed on nine patients (2% of those who had CSI), all of which were negative for SARS-CoV-2 RNA, and five patients (1.1%) received an SARS-CoV-2 IgG antibody test, of which 2 (0.5%) were positive consistent with prior COVID-19 infection, however both patients were asymptomatic. Seven patients (1.6%) had radiological investigations for respiratory symptoms. One patient with indeterminate ground glass change was identified. Conclusion. The incidence of positive COVID-19 infection following corticosteroid injections was very low in our cohort and no adverse clinical outcomes related to COVID-19 infection following CSI were identified. Our findings are consistent with CSI likely being low risk during the COVID-19 pandemic. The results of this small observational study are supportive of the current multi-society guidelines regarding the judicious use of CSI. Cite this article: Bone Joint Open 2020;1-9:605–611

Aims. The primary aim of this study was to assess the feasibility of recruiting and retaining patients to a patient-blinded randomized controlled trial comparing corticosteroid injection (CSI) to autologous protein solution (APS) injection for the treatment of subacromial shoulder pain in a community care setting. The study focused on recruitment rates and retention of participants throughout, and collected data on the interventions’ safety and efficacy. Methods. Participants were recruited from two community musculoskeletal treatment centres in the UK. Patients were eligible if aged 18 years or older, and had a clinical diagnosis of subacromial impingement syndrome which the treating clinician thought was suitable for treatment with a subacromial injection. Consenting patients were randomly allocated 1:1 to a patient-blinded subacromial injection of CSI (standard care) or APS. The primary outcome measures of this study relate to rates of recruitment, retention, and compliance with intervention and follow-up to determine feasibility. Secondary outcome measures relate to the safety and efficacy of the interventions. Results. A total of 53 patients were deemed eligible, and 50 patients (94%) recruited between April 2022 and October 2022. Overall, 49 patients (98%) complied with treatment. Outcome data were collected in 100% of participants at three months and 94% at six months. There were no significant adverse events. Both groups demonstrated improvement in patient-reported outcome measures over the six-month period. Conclusion. Our study shows that it is feasible to recruit to a patient-blinded randomized controlled trial comparing APS and CSI for subacromial pain in terms of clinical outcomes and health-resource use in the UK. Safety and efficacy data are presented. Cite this article: Bone Jt Open 2024;5(7):534–542

Total Knee Arthroplasty (TKA) improves the quality of life of osteoarthritic and rheumatoid arthritis patients, however, is associated with moderate to severe postoperative pain. There are multiple methods of managing postoperative pain that include epidural anesthesia but it prevents early mobilization and results in postoperative hypotension and spinal infection. Controlling local pain pathways through intra-articular administration of analgesics is a novel method and is inexpensive and simple. Hence, we assess the effects of postoperative epidural bupivacaine injection along with intra-articular injection in total knee replacement patients. The methodology included 100 patients undergoing TKA randomly divided into two groups, one administered with only epidural bupivacaine injection and the other with intra-articular cocktail injection. The results were measured based on a 10-point pain assessment scale, knee's range of motion (ROM), and Lysholm knee score. The VAS score was lower in the intra-articular cocktail group compared to the bupivacaine injection group until the end of 1-week post-administration (p<0.01). Among inter-group comparisons, we observed that the range of motion was significantly more in cocktail injection as compared to the bupivacaine group till the end of one week (p<0.05). Lysholm's score was significantly more in cocktail injection as compared to the bupivacaine group till the end of one week (p<0.05). Our study showed that both epidural bupivacaine injection and intra-articular injection were effective in reducing pain after TKA and have a comparable functional outcome at the end of 4 weeks follow up. However, the pain relief was faster in cases with intra-articular injection, providing the opportunity for early rehabilitation. Thus, we recommend the use of intra-articular cocktail injection for postoperative management of pain after total knee arthroplasty, which enables early rehabilitation and faster functional recovery of these patients

Interstitial supraspinatus tears can cause persistent subacromial impingement symptoms despite non operative treatment. Autologous tendon cell injection (ATI) is a non-surgical treatment for tendinopathies and tear. We report a randomised controlled study of ATI compared to corticosteroid injection (CS) as treatment for interstitial supraspinatus tears and tendinopathy. Inclusion criteria were patients with symptom duration > 6 months, MRI confirmed intrasubstance supraspinatus tear, and prior treatment with physiotherapy and ≥ one CS or PRP injection. Participants were randomised to receive ATI to the interstitial tear or corticosteroid injection to the subacromial bursa in a 2:1 ratio, under ultrasound guidance. Assessments of pain (VAS) and function (ASES) were performed at baseline, and 1, 3, 6 and 12 months post treatment. 30 participants (19 randomised to ATI) with a mean age of 50.5 years (10 females) and a mean duration of symptoms of 23.5 months. Baseline VAS pain and ASES scores were comparable between groups. While mean VAS pain scores improved in both groups at 3 months after treatment, pain scores were superior with ATI at 6 months (p=0.01). Mean ASES scores in the ATI group were superior to the CS group at 3 months (p=0.026) and 6 months (p=0.012). Seven participants in the CS group withdrew prior to 12 months due to lack of improvement. At 12 months, mean VAS pain in the ATI group was 1.6 ± 1.3. The improvements in mean ASES scores in the ATI group at 6 and 12 months were greater than the MCID (12.0 points). At 12 months, 95% of ATI participants had an ASES score > the PASS (patient acceptable symptom state). This is the first level one study using ATI to treat interstitial supraspinatus tear. ATI results in a significant reduction in pain and improvement in shoulder function

Aims. Intra-articular (IA) injection may be used when treating hip osteoarthritis (OA). Common injections include steroids, hyaluronic acid (HA), local anaesthetic, and platelet-rich plasma (PRP). Network meta-analysis allows for comparisons between two or more treatment groups and uses direct and indirect comparisons between interventions. This network meta-analysis aims to compare the efficacy of various IA injections used in the management of hip OA with a follow-up of up to six months. Methods. This systematic review and network meta-analysis used a Bayesian random-effects model to evaluate the direct and indirect comparisons among all treatment options. PubMed, Web of Science, Clinicaltrial.gov, EMBASE, MEDLINE, and the Cochrane Library were searched from inception to February 2023. Randomized controlled trials (RCTs) which evaluate the efficacy of HA, PRP, local anaesthetic, steroid, steroid+anaesthetic, HA+PRP, and physiological saline injection as a placebo, for patients with hip OA were included. Results. In this meta-analysis of 16 RCTs with a total of 1,735 participants, steroid injection was found to be significantly more effective than placebo injection on reported pain at three months, but no significant difference was observed at six months. Furthermore, steroid injection was considerably more effective than placebo injection for functional outcomes at three months, while the combination of HA+PRP injection was substantially more effective at six months. Conclusion. Evidence suggests that steroid injection is more effective than saline injection for the treatment of hip joint pain, and restoration of functional outcomes. Cite this article: Bone Joint J 2024;106-B(6):532–539

Aims. We aimed to establish the short- and long-term efficacy of corticosteroid injection for coccydynia, and to determine if betamethasone or triamcinolone has the best effect. Methods. During 2009 to 2016, we treated 277 patients with chronic coccydynia with either one 6 mg betamethasone or one 20 mg triamcinolone cortisone injection. A susequent injection was given to 62 (26%) of the patients. All were reviewed three to four months after injection, and 241 replied to a questionnaire a mean of 36 months (12 to 88) after the last injection. No pain at the early review was considered early success. When the patient had not been subsequently operated on, and indicated on the questionnaire that they were either well or much better, it was considered a long-term success. Results. At the three- to four-month review, 22 (9%) reported that they had no pain. The long-term success of one injection was 15% and rose to 29% after a second injection. Logistic regression tests showed that both early success (odds ratio (OR) 5.5, 95% confidence interval (CI) 2.1 to 14.4; p = 0.001) and late success (OR 3.7, 95% CI 1.7 to 8.3; p = 0.001) was greater with triamcinolone than with betamethasone. Late success was greater for patients with symptoms for less than 12 months (OR 3.0, 95% CI 1.4 to 6.7; p = 0.006). We saw no complications of the injections. Conclusion. We conclude that the effect of corticosteroid injection for coccygodynia is moderate, possibly because we used modest doses of the drugs. Even so, they seem worthwhile as they are easily and quickly performed, and complications are rare. If the choice is between injections of betamethasone or triamcinolone, the latter should be selected. Cite this article: Bone Joint Open 2020;1-11:709–714

Introduction. Liposomal bupivacaine has been shown to be effective in managing post-operative pain in hallux valgus and hemorrhoid surgery. However, non-industry-supported and well-powered randomized studies evaluating its efficacy in Total Knee Arthroplasty (TKA) are lacking. Our hypothesis was that liposomal bupivacaine would not decrease post-operative visual analog pain scores (VAS) or narcotic consumption in the acute post-operative period. Methodology. Two hundred seven consecutive patients were enrolled into a single-blinded prospective randomized study. We included patients undergoing unilateral TKA by five fellowship-trained surgeons with a diagnosis of osteoarthritis, rheumatoid arthritis, or post-traumatic arthritis. Patients were excluded for any other diagnosis necessitating TKA, allergy to the medications, or pre-operative opiate use. Participants received standardized pain management, anesthesia, and physical therapy. Patients were randomized intra-operatively to one of three groups: an intra-articular (IA) injection of bupivacaine and morphine at the conclusion of the procedure, a peri-articular (PA) injection of a bupivacaine and morphine, or a PA injection of liposomal bupivacaine. Post-operative pain VAS and mean morphine equivalents (MME) consumed were recorded and compared utilizing analysis of variance (ANOVA). A power analysis demonstrated that 159 patients were needed for 80% power to detect a 25% difference in VAS or MME. Results. Patients in each study group had a mean VAS score of 3.95 (SD 2.1), 3.97 (SD 1.9). and 3.86 (SD 1.8) (p=0.94), respectively. MME consumed per day in each group was 100.7 (SD 48.4), 100.1 (SD 42.2), and 98.9 (SD 41.6) (p=0.97). Conclusion. Liposomal bupivacaine does not alter mean pain scores or post-operative narcotic consumption in patients undergoing unilateral TKA. Further, no difference was noted in comparing patients who received a single IA injection versus a PA injection. To our knowledge, this is the first reported study to evaluate post-operative pain control between identical IA and PA injections in patients undergoing unilateral TKA

Aims. There is conflicting evidence on the safety of intra-articular injections of hyaluronic acid (HA) or corticosteroids (CSs) before total knee arthroplasty (TKA). We performed a meta-analysis of the relationship between intra-articular injections and subsequent infection rates after TKA. Methods. We searched PubMed, EMBASE, and the Cochrane Library for cohort studies that assessed the effect of preoperative injection of drugs into the joint cavity on the infection rate after TKA. The outcomes analyzed included the total infection rate, as well as those for different preoperative injection time periods and different drugs. Results. Eight studies, including 73,880 in the injection group and 126,187 in the control group, met the inclusion criteria. The injection group had a significantly higher postoperative infection rate than the control group (risk ratio (RR) 1.16; 95% confidence interval (CI) 1.07 to 1.27; p < 0.001; I. 2. = 32%). For patients who received injections up to three months preoperatively, the postoperative infection risk was significantly higher than that in the control group (RR 1.26; 95% CI 1.18 to 1.35; p＜0.001; I. 2. = 0%). There was no significant difference in the infection rates between the four-to-six-month injection and control groups (RR 1.12; 95% CI 0.93 to 1.35; p = 0.240; I. 2. = 75%) or between the seven-to-12-month injection and control groups (RR 1.02; 95% CI 0.94 to 1.12; p = 0.600; I. 2. = 0%). Conclusion. Current evidence suggests that intra-articular injections of CSs or HA before TKA increase the risk of postoperative infection. Injections administered more than three months before TKA do not significantly increase the risk of infection. Cite this article: Bone Joint Res 2022;11(3):171–179

A promising application of Mesenchymal stem cells (MSCs) is the treatment of non-unions. Substituting bone grafts, MSCs are directly injected into the fracture gap. High cell viability seems to be a prerequisite for therapeutic success. Administration of the MSCs via injection creates shear stresses possibly damaging or destroying the cells. Aim of this study was to investigate the effect of the injection process on cell viability. MSCs were isolated and cultivated from femoral tissue of five subjects undergoing arthroplasty. Prior to injection, the cells were identified as MSCs. After dissolving to a concentration of 1 Million cells/ml, 1 ml of the suspension was injected through a cannula of 200 mm length and 2 mm diameter (14 G) with flow rates of 38 and 100 ml/min. The viability of the MSCs at different flow rates was evaluated by staining to detect the healthy cell fraction. It was analyzed statistically against a control group via the Kruskal-Wallis-test and for equivalence via the TOST procedure. Significance level was set to 5 %, equivalence margin to 20 %. The healthy cell fraction of the control group was 85.88 ± 2.98 %, 86.04 ± 2.53 % at 38 ml/min and 85.48 ± 1.64 % at 100 ml/min. There was no significant difference between the fraction of healthy cells (p = 0.99) for different volume flows, but a significant equivalence between the control group and the two volume flows (38 ml/min: p = 0.002, 100 ml/min: p = 0.001). When injecting MSC solutions, e.g. into a non-union, the viability of the injected cells does not deterioriate significant. The injecting technique is therefore feasible

Introduction and Objective. Total shoulder replacement is a common elective procedure offered to patients with end stage arthritis. While most patients experience significant pain relief and improved function within months of surgery, some remain unsatisfied because of residual pain or dissatisfaction with their functional status. Among these patients, when laboratory workup eliminates infection as a possibility, corticosteroid injection (CSI) into the joint space, or on the periprosthetic anatomic structures, is a common procedure used for symptom management. However, the efficacy and safety of this procedure has not been previously reported in shoulder literature. Materials and Methods. A retrospective chart review identified primary TSA patients who subsequently received a CSI into a replaced shoulder from 2011 – 2018 by multiple surgeons. Patients receiving an injection underwent clinical exam, laboratory analysis to rule out infection, and radiographic evaluation prior to CSI. Demographic variables were recorded, and a patient satisfaction survey assessed the efficacy of the injection. Results. Of the 43 responders, 48.8% remembered the injection. The average time from index arthroplasty to injection was median 16.8 months. Overall, 61.9% reported decreased pain, 28.6% reported increased motion, and 28.6% reported long term decreased swelling. Improvement lasted greater than one month for 42.9% of patients, and overall 52.4% reported improvement (slight to great) in the shoulder following CSI. No patient developed a periprosthetic joint infection (PJI) within 2 years of injection. Conclusions. This study suggests that certain patients following TSA may benefit from a CSI. However, this should only be performed once clinical, radiographic, and laboratory examination has ruled out conditions unlikely to improve long term from a CSI. Given these findings, further study in a large, prospective trial is warranted to fully evaluate the benefits of CSI following TSA

Purpose. Intra-articular corticosteroid injection is widely used for symptomatic relief of knee osteoarthritis. However, if pain is not improved which consequences a total knee arthroplasty (TKA), there is a potential risk of post-operative periprosthetic joint infection (PJI). The aim of this study is to investigate whether the use of preoperative intra-articular corticosteroid injection increases the risk of PJI and to investigate a time frame in which the risk of subsequent infection is significantly increased. Methods. A systematic search was performed in PubMed (Medline), Scopus, and the Cochrane Library. Inclusion criteria were original studies investigating the rate of PJI in patients receiving pre-operative intra-articular corticosteroid injection compared to controls. Results. A total of 380 unique articles were screened. Six studies met the inclusion criteria with 255,627 patients in total. Overall, no statistical significance was observed in the intra-articular infection rate in corticosteroid compared to controls groups. However, intra-articular corticosteroid injections within 3 months prior to TKA were associated with a significantly increased risk of infection (OR: 1.52, 95% CI 1.37–1.67, p < 0.01); this was not observed in the 6-month period (OR: 1.05, 95% CI 0.80–1.39, p = 0.72). Conclusions. Performing an intra-articular corticosteroid injection within 3 months prior to TKA is associated with a significantly increased risk of PJI. The current evidence supports the safe use of intra-articular corticosteroid injection more than 6 months before TKA. However, additional studies are needed to clarify the risk of PJI after TKA implantation between 3 and 6 months after the last corticoid injection

Lumbar steroid injection can be endorsed as a treatment component for lumbrosacral radicular pain syndrome resulting from disc herniation. The facet joint steroid injection seems to be beneficial for patients with chronic backache due to the facet joint arthritis and in the lumbar Spondylosis. We did a retrospective review of 31 patients whom we treated between 2004 and 2005 with follow up of 6 months to 24 months. There were 19 females and 12 males, aged between 29–81 years. Five patients had previous surgery for simple discectomy to posterior spinal fusion. Four patients had multiple disc prolapse at 3–4 levels, 2 patients had a severe lumbar spondylosis and spinal stenosis. The remaining 20 patients had a single level disc prolapse. All these patients were given caudal and facet joint blocks. The pre and post steroid injection Oswestry score was done. After steroid injection the Oswestry score improved by 30%. Majority of the patients had pain relief for 2–18 months. The pain relief was much better in the non operative group with single level disc pro-lapse and those patients with lumbar spondylosis. In patients with chronic back pain there is an inflammatory basis for pain generation. Lumbar steroid injection seems to be beneficial in patients with disc prolapse and lumbar spondylosis. In the literature various randomized trials have been done and their results are controversial. Our study showed definitive improvement in terms of pain and function of our patient

Surgical debridement for medial epicondylitis (ME) is indicated for patients with refractory ME. The clinical efficacy of simple debridement has not been studied sufficiently. Moreover, authors experienced surgical outcome of ME was not as good as lateral epicondylitis. In this regard, authors have combined the atelocollagen injection in the debridement surgery of ME. The purpose of study was to compare clinical outcomes between simple debridement and debridement combined with atelocollagen injection in the ME. Twenty-five patients with refractory ME and underwent surgical debridement were included in the study. Group A (n=13) was treated with isolated debridement surgery, and group B (n=12) was treated with debridement combined with 1.0 mL of type I atelocollagen. Pain and functional improvements were assessed using visual analogue scale, Mayo Elbow Performance Score (MEPS) and quick Disabilities of the Arm, Shoulder and Hand (DASH) scale respectively before surgery, at 3, 6 months after surgery and at the final follow-up. Demographic data did not show significant difference between two groups before surgical procedures. Both groups showed improvement in pain and functional score postoperatively. However, at the 3 months after surgery, group B showed significantly better improvement as compared to group A(VAS 3.1 / 2.0, MEPS 71/82 qDASH 29/23). At the 6 months after surgery and final follow-up, both groups did not show any difference. Surgical debridement combined with atelocollagen is effective treatment option in refractory ME and showed better short-term outcomes compared to isolated surgery

As the intervertebral disc is largely avascular, needle injection is the most practical method for delivery of therapeutic agents used in treatments for degenerative disc disease. Intradiscal pressure increases during injection, and insufficient recovery time prior to needle retraction may result in injectate leakage. In order to determine the maximum pressure and post-injection recovery time for a given injection volume and rate, an analytical model of intradiscal injection was developed and calibrated experimentally. A governing equation was derived defining intradiscal pressure as a function of effective permeability, initial elastic stiffness, nonlinear stiffness term, and injection rate. The equation was solved using a fourth order Runge-Kutta routine with a 0.05s time step and a ramp-dwell injection. The model was calibrated by performing controlled intradiscal injections on five bovine caudal intervertebral discs. Three had adjacent vertebrae intact, while two were separated from vertebrae and constrained between porous stainless steel platens. A syringe driven by a linear actuator was used to inject phosphate buffered saline through a 21g hypodermic needle inserted radially into the disc to a depth of one half of the disc diameter. Injection was performed at a rate of 75μL/s to a volume of 250μL followed by a 240s dwell. Fluid pressure was recorded during both the injection phase and subsequent recovery phase. For each experimental pressure vs time trace, model parameters were varied in order to obtain an optimal fit. The model was run with the average parameter values across a grid of possible injection protocols, with injection volume ranging from 30 to 300μL and injection time ranging from 0.1 to 5s. For each case, peak pressure and time required to reach a 1kPa threshold were recorded. Experimentally measured peak pressure ranged from 68 to 88kPa. Pressure at the end of the 240s dwell ranged from 49 to 69kPa. There was no apparent difference between discs with and without endplates. Leakage of fluid following needle retraction was observed in all specimens. Experimental data were well fit by the analytical model, which predicted higher peak pressure and longer recovery time with increasing volume, from approximately 1500s at 30μL to nearly 3000s at 300μL. The model was nearly insensitive to injection rate. The experimental data confirm pressurization of the disc during injection and injectate leakage resulting from insufficient recovery time. The model predicts that the time required to recover to below threshold leakage pressure is impractically long for both laboratory and clinical injection protocols. Similar behavior with and without endplates confirms that fluid flow is limited by permeability of the tissue itself, not the boundary conditions. Slow recovery is likely attributable to the fact that peak injection pressures were lower than the hydraulic swelling pressure of the nucleus pulposus, which has been reported to be approximately 140kPa. Due to the high swelling pressure of the nucleus pulposus, it is unlikely that intradiscal injection procedures can be performed without substantial injectate leakage following needle retraction

Background. Guidelines recommend epidural steroid injections (ESI) for treating severe disc-related sciatica based on trial data showing modest reductions in leg pain, disability and surgery avoidance. Despite their widespread use, there is no clear evidence about which patients are more likely to benefit from ESI. The aim of this study was to generate consensus on potential predictors of outcome following ESI for disc-related sciatica to include in data collection in a future cohort study. Methods. A list of potential predictors of outcome following ESI was generated from existing literature and a consensus meeting with seven experts. Items were subsequently presented in a two-round on-line modified Delphi study to generate consensus among experts on which items are agreed as potential predictors of outcome from ESI (consensus defined as 70% agreement with ranking of remaining items). Results. An initial list of 53 items was generated and 90 experts were invited from seven countries to participate in the on-line Delphi study. Response rates were 48% (n=44) and 73% (n=33) for round 1 and 2 respectively. Twenty-eight additional items suggested by participants in round 1 were included in round 2. Of the 81 items, 14 reached consensus; across domains of medication use, previous surgery, pain intensity, psychosocial factors, imaging findings and type of injection. Highest ranked of remaining items included work-related and clinical assessment items. Conclusion. Based on expert consensus, items that can be routinely collected in clinical practice were identified as potential predictors of outcomes following ESI. These will be tested in a future multicentre cohort study. Conflicts of interest: No conflicts of interest. Sources of funding: This study is supported by Health Education England and the National Institute for Health Research (HEE/ NIHR ICA Programme Clinical Lectureship, Dr Siobhan Stynes, NIHR300441). The views expressed are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Care

Surgeon-performed periarticular injection and anesthesiologist-performed femoral nerve or adductor canal block with local anesthetic have been used in multimodal pain management for total knee arthroplasty (TKA) patients. Anesthesiologist-performed adductor canal blocks are costly, time consuming, and may be unreliable. We investigated the feasibility of a surgeon-performed saphenous nerve (“adductor-canal”) block from within the knee joint. A retrospective analysis of 94 thigh-knee MRI studies was performed to determine the relationship between the width of the distal femur at the epicondylar axis and the proximal location of the saphenous nerve after its exit from the adductor canal and separation from the superficial femoral artery. After obtaining these data, TKA resections and trial component implantation were performed, using a medial parapatellar approach, in 11 fresh cadaveric lower extremity specimens. Using a blunt tip 1.5cm needle, we injected 10 ml each of two different colored solutions at two different intra-articular medial injection locations, and after 30 minutes, dissected the femoral and saphenous nerve and femoral artery from the hip to the knee to determine the location of the injections. Based upon the MRI analysis, the saphenous nerve was located (and had exited the adductor canal) at a mean of 1.5 times the epicondylar width in females, and mean 1.3 times the epicondylar width in males, proximal to the medial epicondyle. After placement of TKA trial components and injection, the proximal injection site solution bathed the saphenous nerve in 8 of 11 specimens. The proximal blunt needle and solution was adjacent, but did not puncture, the femoral artery and vein in only one specimen. This study suggests that a surgeon-performed injection of the saphenous nerve from within the knee is a feasible procedure. This technique may be a useful alternative to ultrasound guided block. A trial comparing surgeon and anesthesiologist-performed nerve block should be considered to determine the clinical efficacy of this procedure. Our anecdotal use of this intra-articular injection over the past year has been favorable. Newer, extended release anesthetic agents should be investigated with this technique

Interscalene brachial plexus block is the standard regional analgesic technique for shoulder surgery. Given its adverse effects, alternative techniques have been explored. Reports suggest that the erector spinae plane block may potentially provide effective analgesia following shoulder surgery. However, its analgesic efficacy for shoulder surgery compared with placebo or local anaesthetic infiltration has never been established. We conducted a randomised controlled trial to compare the analgesic efficacy of pre-operative T2 erector spinae plane block with peri-articular infiltration at the end of surgery. Sixty-two patients undergoing arthroscopic shoulder repair were randomly assigned to receive active erector spinae plane block with saline peri-articular injection (n = 31) or active peri-articular injection with saline erector spinae plane block (n = 31) in a blinded double-dummy design. Primary outcome was resting pain score in recovery. Secondary outcomes included pain scores with movement; opioid use; patient satisfaction; adverse effects in hospital; and outcomes at 24 h and 1 month. There was no difference in pain scores in recovery, with a median difference (95%CI) of 0.6 (-1.9-3.1), p = 0.65. Median postoperative oral morphine equivalent utilisation was significantly higher in the erector spinae plane group (21 mg vs. 12 mg; p = 0.028). Itching was observed in 10% of patients who received erector spinae plane block and there was no difference in the incidence of significant nausea and vomiting. Patient satisfaction scores, and pain scores and opioid use at 24 h were similar. At 1 month, six (peri-articular injection) and eight (erector spinae plane block) patients reported persistent pain. Erector spinae plane block was not superior to peri-articular injection for arthroscopic shoulder surgery