Aims. The efficacy of saline irrigation for treatment of implant-associated infections is limited in the presence of porous metallic implants. This study evaluated the therapeutic efficacy of antibiotic doped bioceramic (vancomycin/tobramycin-doped polyvinyl alcohol composite (PVA-VAN/TOB-P)) after saline wash in a mouse infection model implanted with titanium cylinders. Methods. Air pouches created in female BalBc mice by subcutaneous injection of air. In the first of two independent studies, pouches were implanted with titanium cylinders (400, 700, and 100 µm pore sizes) and inoculated with Staphylococcus aureus (1 × 10. 3. or 1 × 10. 6. colony-forming units (CFU)/pouch) to establish infection and biofilm formation. Mice were killed after one week for microbiological analysis. In the second study, pouches were implanted with 400 µm titanium cylinders and inoculated with S. aureus (1 × 10. 3. or 1 × 10. 6. CFU/pouch). Four groups were tested: 1) no bacteria; 2) bacteria without saline wash; 3) saline wash only; and 4) saline wash plus PVA-VAN/TOB-P. After seven days, the pouches were opened and washed with saline alone, or had an additional injection of PVA-VAN/TOB-P. Mice were killed 14 days after pouch wash. Results. The first part of the study showed that low-grade infection was more significant in 400 µm cylinders than cylinders with larger pore sizes (p < 0.05). The second part of the study showed that saline wash alone was ineffective in eradicating both low- and high-grade infections. Saline plus PVA-VAN/TOB-P eradicated the titanium cylinder-associated infections, as manifested by negative cultures of the washouts and supported by scanning electron microscopy and histology. Conclusion. Porous titanium cylinders were vulnerable to bacterial infection and biofilm formation that could not be treated by saline irrigation alone. Application of PVA-VAN/TOB-P directly into the surgical site alone or after saline wash represents a feasible approach for prevention and/or treatment of porous implant-related infections. Cite this article: Bone Joint Res 2024;13(11):622–631

Background. Open fracture wounds are well known to be associated with infection & prolonged healing. Activity in scientific research to improve wound healing has often provided variable results. This study was done to question the de facto nature of Normal Saline as best irrigant in management of such wounds and to find out a better irrigant, if so, that does exist with due consideration to the mechanism by which saline dressings act. Material and methods. 30 patients with Grade 3 open fracture wounds were assessed over a period of three months according to Ganga Hospital Injury severity Score and were divided equally in study and control groups after adequate matching. A standard dressing protocol consisting of debridement and external fixation within 6 hours, avoidance of any antiseptic or surfactant agent, high-volume low-pressure pulsatile lavage irrigation and saline soaked gamgee pad packings with concerned solutions changed twice daily was done in respective groups. Follow-up was done by colour of healing granulation tissue, pus culture and soft tissue biopsy at Day 1, 3,7,10 & 14. Results. 6 out of 15(40%) wounds in study group were observed to have reached pink healthy granulation with low exudate by Day 14 as compared to only 3 out of 15(20%) in control group. The time taken to traverse from each stage of healing granulation was also observed to be smaller with 3% NaCl as compared to 0.9% NaCl. Although once healthy granulation stage was reached, further dressing with 3% NaCl in study group was shown to have worsening of granulation in about 33% of cases with none such observed in control. Conclusion. 3% NaCl is a better irrigant than 0.9% NaCl for dressing of Open trauma wounds during initial stages of dressing. Their effectivity in maintaining advanced granulation is although questionable, probably owing to its desiccative action

The efficacy of saline irrigation for the treatment of periprosthetic infection (PJI) is limited in the presence of infected implants. This study evaluated the efficacy of vancomycin/tobramycin-doped polyvinyl alcohol (PVA)/ceramic composites (PVA-VAN/TOB-P) after saline irrigation in a mouse pouch infection model. 3D printed porous titanium (Ti) cylinders (400, 700 and 100 µm in pore size) were implanted into mice pouches, then inoculated with S. aureus at the amounts of 1X10. 3. CFU and 1X10. 6. CFU per pouch, respectively. Mice were randomized into 4 groups (n=6 for each group): (1) no bacteria; (2) bacteria without saline wash; 3) saline wash only, and (4) saline wash+PVA-VAN/TOB-P. After seven days, pouches were washed out alone or with additional injection of 0.2 ml of PVA-VAN/TOB-P. Mice were sacrificed 14 days after pouch wash. Bacteria cultures of collected Ti cylinders and washout fluid and histology of pouch tissues were performed. The low-grade infection (1X10. 3. CFU) was more significant in 400 µm Ti cylinders than that in Ti cylinders with larger pore sizes (700 and 1000 µm (p<0.05). A similar pattern of high-grade infection (1X10. 6. CFU) was observed (p<0.05). For the end wash, the bacteria burden (0.49±0.02) in saline wash group was completely eradicated by the addition of PVA-VAN/TOB-P (0.005±0.001, p<0.05). We noticed that 400 µm Ti cylinders have the highest risk of implant infection. Our data supported that the effect of saline irrigation was very limited in the presence of contaminated porous Ti cylinders. PVA-VAN/TOB-P was biodegradable, biocompatible, and was effective in eradicating bacteria retention after saline irrigation in a mouse model of low grade and high-grade infection. We believe that PVA-VAN/TOB-P represents an alternative to reduce the risk of PJI by providing a sustained local delivery of antibiotics

Background. In the setting of a “dry” aspiration, saline lavage is commonly used to obtain a sample for analysis. The purpose of this study is to prospectively determine the impact of saline lavage on synovial fluid markers in revision arthroplasty. Methods. 79 patients undergoing revision hip (19) and knee (60) arthroplasty were enrolled. Intraoperatively, prior to arthrotomy, the maximum amount of fluid possible was aspirated to simulate a dry-tap (“pre-lavage”) followed by subsequent injection with 20 mL of normal saline and re-aspiration (“post-lavage”). Pre and post-lavage synovial white blood cell (WBC) count, percent polymorphonuclear cells (%PMN), and cultures were compared. Statistical analyses utilized the Wilcoxon signed-rank test. Results. Nine patients met modified MSIS criteria for prosthetic joint infection (PJI). Pre and post-lavage %PMN were similar in septic patients (90.1% vs. 88.2%, p=0.40 for septic). Pre and post-lavage WBC counts were different in both cohorts (69,432 vs. 6,547 WBCs, p=0.008 for septic; 1,850 vs. 449 WBCs for aseptic, p<0.001). Using a pre-lavage cutoff of >80% PMN, the post-lavage aspirate correctly identified 84.6% of true positives (sensitivity) and 98.5% of true negatives (specificity). Using a pre-lavage cutoff of >3000 WBCs, the post-lavage aspirate correctly identified only 38.1% of true positives (sensitivity). As the synovial fluid WBC count increased, the correlation between pre and post-lavage %PMN was stronger (mean difference of 7.0% PMN in WBC <3000 vs. mean difference −2.9% PMN in WBC >3000, p=0.002). Of seven positive pre-lavage fluid cultures, 4 remained positive post-lavage. Conclusion. While saline lavage aspiration significantly lowers the synovial WBC count, the %PMN is well maintained, particularly at WBC counts >3000. Our findings suggest that in the setting of a dry tap where saline lavage is required to obtain a sample, the %PMN has reasonable sensitivity and specificity for the detection of PJI. For figures, tables, or references, please contact authors directly

Introduction. Pre-operative aspiration and culture is the gold standard for the diagnosis of peri-prosthetic infection. This study aimed to ascertain the diagnostic accuracy of culture of joint aspiration with or without saline re-aspiration in the event of a dry-tap. Patients/Materials & Methods. Retrospective analysis of 343 hip aspirations in patients deemed to have moderate-high risk of infection and ultimately proceeded to revision arthroplasty over 12 years at a large quaternary referral centre where pre-operative aspiration is routine. Results. Fluid was aspirated in 141(41%) cases and dry taps in which saline injection-re-aspiration was performed occurred in 202 (59%) cases. Overall sensitivity and specificity of diagnostic aspirate were 82% (74–88%) and 79% (74–84%) respectively. Sensitivity and specificity of saline injection-re-aspiration after dry tap were 79% (64–87%) and 86% (78–92%) compared to 84% (74–91%) and 74% (66–81%) for direct aspiration. Discussion. Pre-operative joint aspiration and culture is a sensitive and specific test for the confirmation of diagnosis in patients at a moderate to high risk of prosthetic joint infection. Culture of saline injection-re-aspiration also provides accurate diagnostic information in the event of a dry tap. Both methods allow susceptibility testing of relevant organisms and are therefore able to guide peri-operative and cement instilled antibiotic therapy. Conclusions. Culture of pre-operative joint aspirates provides sensitive and specific diagnostic information, including antimicrobial susceptibility results. Saline injection-re-aspiration is a useful additional technique in those patients in whom fluid cannot be aspirated

No single test is 100% sensitive and specific for the diagnosis of prosthetic joint infection. Joint aspiration is currently the only preoperative investigation that can establish the identity of the infecting organism and its antibiotic susceptibilities. Frequently when attempting to aspirate a joint a ‘dry tap occurs as fluid cannot be aspirated. In this situation, normal saline may be injected into the joint and then reaspirated to provide fluid for culture. The aim of this study was to ascertain the diagnostic accuracy of culture of joint aspiratie with or without saline reaspiration in the event of a dry tap. A retrospective analysis of 580 hip and knee aspirations in patients deemed to have moderate-high risk of infection and ultimately proceeded to revision arthroplasty over 12 years at a large quaternary referral centre where pre operative aspiration is routine. Fluid was aspirated in 313 (54%) cases and dry taps in which saline injection reaspiration was performed occurred in 267 (46%) cases. Overall sensitivity and specificity of diagnostic aspiration were 84% (78–89%) and 85% (81–88%) respectively. Sensitivity and specificity of saline injection-reaspiration after dry tap were 87% (79–82%) and 79% (72–84%) compared to 81% (71–88%) and 90% (85–93%) for direct aspiration. Pre operative joint aspiration and culture is a sensitive and specific test for the confirmation of diagnosis in patients at a moderate to high risk of prosthetic joint infection. Culture of saline injection-reaspiration also provides accurate diagnostic information in the event of a dry tap. Both methods allow susceptibility testing of relevant organisms and are therefore able to guide peri-operative and cement instilled antibiotic therapy. Culture of pre operative joint aspirates provides sensitive and specific diagnostic information including antimicrobial susceptibility results. Saline injection-reaspiration is a useful additional technique in those patients in whom fluid cannot be aspirated

Platelet rich plasma has been advocated for the treatment of plantar fasciitis but there are few good quality clinical trials to support its use. We report a pilot double blind randomised controlled trial of platelet rich plasma versus normal saline. Methods. Patients with more than 6 months of MRI proven plantar fasciitis who had failed conservative management were invited to participate in this study. Patients were block randomised to either platelet rich plasma injection (intervention) or equivalent volume of normal saline (control). The techniques used for the injection and rehabilitation were standardised for both groups. The patient and independent assessor were blinded. Visual analogue scale for pain (VAS) and painDETECT were recorded pre-op and at 6 months. Results. Twenty-eight patients (19 females, mean age 50 years) were recruited, with 14 randomised to each arm. At 6 month follow-up, 8 patients (28.6%) were lost to follow-up. There was a significant change in VAS score from baseline to follow-up in both intervention (mean change 37.2, p = 0.008) and control (mean change 42.2, p = 0.003) groups. However there was no difference between the arms in terms of the change in VAS score from baseline to follow-up (p = 0.183). There was no correlation between pre-op PainDETECT score and change in VAS. Conclusion. This pilot study has failed to show a significant benefit of platelet rich plasma compared to saline injection, although both treatments have shown a significant improvement in symptoms. This may be due to the needling effect of injections. A larger study is required to demonstrate a meaningful change. Loss to follow in this patient group should be considered

Aims: Pharmacological modulation of skeletal muscle reperfusion injury after trauma associated ischaemia may improve limb salvage rates and prevent the associated systemic sequelae. Resuscitation with hypertonic saline restores the circulating volume and has favourable effects on tissue perfusion and blood pressure. The purpose of our study was to evaluate the effects of hypertonic saline on skeletal muscle ischaemia reperfusion (I/R) injury and the associated endorgan injury. Methods: Adult male Sprague Dawley rats (n=24) were randomised into three groups: control group, I/R group treated with normal saline and I/R group treated with hypertonic saline. Bilateral hind-limb ischaemia was induced by rubber band application proximal to the level of the greater trochanters for 2.5 hours. Treatment groups received either normal saline or hypertonic saline prior to tourniquet release. Following twelve hours reperfusion, the tibialis anterior muscle was dissected and muscle function assessed electrophysiologically by electrical field stimulation. The animals were then sacrificed and skeletal muscle harvested for evaluation. Lung tissue was also harvested for measurement of wet-to-dry ratio, myeloperoxidase content and histological analysis. Results: Hypertonic saline significantly attenuated skeletal muscle reperfusion injury as shown by reduced twitch and tetanic contractions of the skeletal muscle (Table). There was also a significant reduction in lung injury as demonstrated by differences in wet-to-dry ratio, myeloperoxidase content and histological analysis. Conclusion: Resuscitation with hypertonic saline may have a protective role in attenuating skeletal muscle ischaemia reperfusion injury and its associated systemic sequelae

Objectives: During the past decade, acetabular labrum injury has been increasingly recognized as a cause of hip joint pain. Currently, T1-weited MR arthrography (MRa) with gadolinium is the most popular diagnostic imaging technique used for direct detection of acetabular labrum injury. However, the intra-articular injection of gadolinium is not a procedure approved in Japan. We have conducted radial MRa using T2*-weighted images with saline instead. The purpose of this report was to evaluate the sensitivity, specificity, and accuracy of T2*-weighted MRa with saline for the diagnosis of acetabular labrum injury. Methods: Between November 2005 and March 2007, thirty-two hip joints of 30 patients (8 joints of 7 males and 24 joints of 23 females) aged between 13 and 81 (mean; 58) years at the time of study, who underwent MR arthrogram and hip arthroscopy were studied. Prior to performing T2*-weighted MRa, a mixture of 5ml of 2% lidocaine chloride, 5ml of 64% iotrolan, and 15ml of saline was injected under fluoroscopy guidance injected into the hip joint. T2*-weighted MRa was conducted using a 1.5-tesla magnet and local surface coil in radial slices perpendicular to the labral rim, at 15-degree intervals. Radial sequences were operated at T2*-weighted images, Gradient echo method, TR of500ms, TE of 20ms, flip angle of 30 degrees, slice thickness of 5 mm, and FOV of 180 mm. On the MRa, acetabular labrum tear was diagnosed when inflow of contrast medium (high intensity) was observed continuous with the joint space at the base of acetabular labrum. Hip arthroscopy was conducted in the supine position by the standard three portal methods. The results of T2*-weighted MRa were compared with arthroscopic findings to calculate the sensitivity, specificity and accuracy of T2*-weighted MRa. Results: On T2*-weighted MRa, acetabular labrum tear was observed in 17 joints, and no abnormalities in 15 joints. From arthroscopic findings, acetabular labrum tear was observed in 20 joints, and no acetabular labrum abnormalities in 12 joints. Comparing the two methods, the T2*-weighted MRa results were true positive in 17 joints, true negative in 12 joints, and false negative in 3 joints. Therefore, MRa had a sensitivity of 85%, specificity of 100%, and accuracy of 90.6%. Discussion: MRa has become the standard imaging technique for the diagnosis of acetabular labrum tear. The sensitivity was reported to range from 63 to 100%, specificity from 44 to 75%, and precision from 63 to 94%. Our results showed that this method provides sensitivity, specificity and accuracy that approach conventional MRa, demonstrating that radial T2* weighted MRa is a useful imaging technique for the diagnosis of acetabular labrum pathology. Conclusions: We recommend T2*-weighted MRa with saline for the diagnosis of acetabular labrum injury

Elderly patients are at risk of developing cardiopulmonary and cognitive impairment following major orthopaedic surgery. One of the mechanisms believed to be responsible for such complications after total knee arthroplasty (TKA) is the release of embolic debris that may travel from the surgical site, through the lungs, and into the brain following tourniquet release. Removal of fat globules and marrow particulates from bone surfaces prior to pressurization and cementation of prosthetic components may reduce the number and size of embolic particles. We conducted a prospective, randomized clinical trial to compare the effect of carbon dioxide (CO2) gas versus saline lavage on the number and size of embolic particles observed during cemented TKA. Twenty patients undergoing elective TKA were randomly assigned to one of two groups. In group A, standard high-pressure pulsatile saline lavage was used to clean the resected bone surfaces. In group B, the femoral canal was cleaned using CO2 lavage techniques and the resected bone surfaces were cleaned with a manual saline wash followed by CO2 lavage. All patients received the same TKA implant design. The presence of embolic particles in the heart and brain was intraoperatively monitored using transesophageal echocardiography (TEE) and transcranial Doppler (TCD) techniques, respectively. For each patient, TEE images were analyzed at tourniquet release and during the final range of motion (ROM) assessment prior to wound closure using the following five point cardiac echogenic scoring system: Grade 0: no emboli; Grade I: a few fine emboli; Grade II: a cascade of many fine emboli; Grade III: a cascade of fine emboli mixed with at least one embolus > 1 cm in diameter; and Grade IV: large embolic masses > 3 cm in diameter. The highest grade observed during either tourniquet release or ROM assessment was assigned to each patient. Cardiac emboli were then categorized according to embolic grade as follows: Grade 0 or I = Low; Grade II, III, or IV = High. For analysis of cerebral emboli, the total number of positive counts measured using TCD was recorded for each patient. TEE data were available for nine patients in group A and eight patients in group B. Comparative TCD data were available for seven patients in group A and six patients in group B. Fischer’s Exact Test was used to check for differences between groups. For cardiac emboli, nine of nine (100%) patients in group A were in the High category based on their TEE grade, with eight patients being Grade II and one Grade III. In contrast, three of eight (37.5%) patients in group B were in the Low category, leaving only five (62.5%) in the High category (p = 0.08). All five group B patients in the High category were Grade II. No patients in group A had cerebral emboli detected using TCD. In group B, three of six patients had one cerebral embolus and the remaining three had none. Three patients in group B were excluded from the comparative TCD analysis due to the presence of a patent foramen ovale (PFO). These three patients with a PFO had one, three, and four cerebral emboli, respectively. No patients in group A had a PFO. This study examines the effect of pulsatile saline versus CO2 gas lavage on intraoperative embolic events during TKA. Thirty-seven percent of patients in the CO2 lavage group had a Low cardiac echogenic score compared with 0% of patients in the standard pulsatile saline lavage group. A single cerebral embolus was detected in three of six patients in the CO2 lavage group compared with none in the seven patients in the standard pulsatile saline lavage group. Compared to published studies on cerebral emboli in TKA, the overall incidence of cerebral emboli in the current study was very low across both groups. The results of this study suggest that CO2 gas, as compared to pulsatile saline, lavage reduces the number of intraoperative cardiac emboli during total knee arthroplasty

Aims. Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI). Methods. A total of 56 male Sprague-Dawley rats were established in acute PJI models by intra-articular injection of bacteria. The rats were divided into four groups: a Control group, a 0.35% PI group, a LIPUS and saline group, and a LIPUS and 0.35% PI group. All rats underwent DAIR, except for Control, which underwent a sham procedure. General status, serum biochemical markers, weightbearing analysis, radiographs, micro-CT analysis, scanning electron microscopy of the prostheses, microbiological analysis, macroscope, and histopathology evaluation were performed 14 days after DAIR. Results. The group with LIPUS and 0.35% PI exhibited decreased levels of serum biochemical markers, improved weightbearing scores, reduced reactive bone changes, absence of viable bacteria, and decreased inflammation compared to the Control group. Despite the greater antibiofilm activity observed in the PI group compared to the LIPUS and saline group, none of the monotherapies were successful in preventing reactive bone changes or eliminating the infection. Conclusion. In the rat model of PJI treated with DAIR, LIPUS combined with 0.35% PI demonstrated stronger antibiofilm potential than monotherapy, without impairing any local soft-tissue. Cite this article: Bone Joint Res 2024;13(7):332–341

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

Background: Animal studies have shown that 0.9% NaCl causes inhibition of proteoglycan metabolism in articular cartilage yet it continues to be the most commonly used irrigation fluid for arthroscopic surgery. Ringer’s solution and non ionic fluids have been shown to cause less damage. There is currently no such comparison in human articular cartilage. The aim of this study was to assess the effect of different irrigation fluids on arthritic and non arthritic human articular cartilage. Materials and Methods: Non arthritic cartilage specimens were obtained from femoral heads of hip fracture patients undergoing hemiarthroplasty where there were no radiological or macroscopic signs of osteoarthritis. Arthritic articular cartilage was obtained from tibial plateau of total knee arthroplasty patients or femoral heads with macroscopic signs of osteoarthritis. Cartilage explants were exposed to either 0.9% normal saline or Ringer’s solution, 1.5% Glycine, 10% Mannitol or a control solution of M199 culture medium. 0.5% bupivacaine, which has been shown to be toxic to chondrocytes, was used as a second control solution. The specimens were then incubated in culture medium containing radiolabelled 35-SO4 for 16 hours and uptake was measured as counts per gram per minute. Results: In non arthritic cartilage, the inhibition of proteoglycan synthesis was 0% with Ringer’s solution (p> 0.05), 3% with Glycine and Mannitol (p> 0.05), 12% with 0.9% NaCl (p> 0.05) and 75% with 0.5% bupivacaine (p< 0.001). In arthritic cartilage, the inhibition was 15% with Ringer’s solution (p> 0.05), 20% with Mannitol (p> 0.05), 30% with 0.9% NaCl and Glycine (p=0.04) and 85% with 0.5% bupivacaine (p< 0.001). Conclusion: Normal saline was most harmful to human articular cartilage. Ringer’s solution was the best solution for joint irrigation. We have provided yet more evidence to suggest that 0.5% bupivacaine is severely toxic to articular cartilage

Aims. Orthopaedic surgery uses many varied instruments with high-speed, high-impact, thermal energy and sometimes heavy instruments, all of which potentially result in aerosolization of contaminated blood, tissue, and bone, raising concerns for clinicians’ health. This study quantifies the aerosol exposure by measuring the number and size distribution of the particles reaching the lead surgeon during key orthopaedic operations. Methods. The aerosol yield from 17 orthopaedic open surgeries (on the knee, hip, and shoulder) was recorded at the position of the lead surgeon using an Aerodynamic Particle Sizer (APS; 0.5 to 20 μm diameter particles) sampling at 1 s time resolution. Through timestamping, detected aerosol was attributed to specific procedures. Results. Diathermy (electrocautery) and oscillating bone saw use had a high aerosol yield (> 100 particles detected per s) consistent with high exposure to aerosol in the respirable range (< 5 µm) for the lead surgeon. Pulsed lavage, reaming, osteotome use, and jig application/removal were medium aerosol yield (10 to 100 particles s. -1. ). However, pulsed lavage aerosol was largely attributed to the saline jet, osteotome use was always brief, and jig application/removal had a large variability in the associated aerosol yield. Suctioning (with/without saline irrigation) had a low aerosol yield (< 10 particles s. -1. ). Most surprisingly, other high-speed procedures, such as drilling and screwing, had low aerosol yields. Conclusion. This work suggests that additional precautions should be recommended for diathermy and bone sawing, such as enhanced personal protective equipment or the use of suction devices to reduce exposure. Cite this article: Bone Joint Res 2023;12(10):636–643

Introduction and Aims: Achieving bloodless surgical field is vital for any arthroscopy surgery. Olszewski et al showed that dilute adrenaline saline irrigation (1mg/l) improves the clarity of operative field by reducing the bleeding. Jensen et al also showed that dilute adrenaline saline irrigation (0.33mg/l) is beneficial in achieving bloodless field in shoulder arthroscopy. Method: A prospective, randomised, double blind, control trial was carried out to determine the effect of adrenaline (epinephrine) in knee arthroscopy without tourniquet. Ethics Committee approval was obtained for this study. A Doctors/Dentists Exemption Certificate (DDX) was obtained from Medicines Control Agency (UK govt) for use of adrenaline (epinephrine) in this trial. All patients undergoing knee arthroscopy were randomised into two groups: 1) to have dilute adrenaline (1 mg of adrenaline into three-litre bags of normal saline (0.33mg/l) for irrigation); and 2) not to have dilute adrenaline in normal saline irrigation. Results: A total of 40 patients (24 male and 16 female) were included in the trial. All operations were performed using pressure-controlled pump system (75 mm Hg). No tourniquets were used. A visual analogue score (VAS) of zero to 10 (worst to best) was used by the surgeon to determine the clarity of surgical field at the end of operation. Mean age was 46.5 years (IQR 27–63 years). Twenty patients had dilute adrenaline saline irrigation and 20 had normal saline irrigation. Mean VAS was 8.5 (IQR 6 – 10). Mean VAS for group 1 was 8.4 and for group 2 was 8.7 (p= 0.59). There were no intra-operative or immediate post-operative complications noted in either group. Conclusion: The study failed to identify any benefit of using adrenaline (epinephrine) in normal saline irrigation fluid in terms of achieving bloodless surgical field in knee arthroscopy. The study also conclude that pressure controlled pump system provides excellent bloodless surgical field in knee arthroscopy without tourniquet

Aims. To achieve expert clinical consensus in the delivery of hydrodilatation for the treatment of primary frozen shoulder to inform clinical practice and the design of an intervention for evaluation. Methods. We conducted a two-stage, electronic questionnaire-based, modified Delphi survey of shoulder experts in the UK NHS. Round one required positive, negative, or neutral ratings about hydrodilatation. In round two, each participant was reminded of their round one responses and the modal (or ‘group’) response from all participants. This allowed participants to modify their responses in round two. We proposed respectively mandating or encouraging elements of hydrodilatation with 100% and 90% positive consensus, and respectively disallowing or discouraging with 90% and 80% negative consensus. Other elements would be optional. Results. Between 4 August 2020 and 4 August 2021, shoulder experts from 47 hospitals in the UK completed the study. There were 106 participants (consultant upper limb orthopaedic surgeons, n = 50; consultant radiologists, n = 52; consultant physiotherapist, n = 1; extended scope physiotherapists, n = 3) who completed round one, of whom 97 (92%) completed round two. No elements of hydrodilatation were “mandated” (100% positive rating). Elements that were “encouraged” (≥ 80% positive rating) were the use of image guidance, local anaesthetic, normal saline, and steroids to deliver the injection. Injecting according to patient tolerance, physiotherapy, and home exercises were also “encouraged”. No elements were “discouraged” (≥ 80% negative rating) although using hypertonic saline was rated as being “disallowed” (≥ 90% negative rating). Conclusion. In the absence of rigorous evidence, our Delphi study allowed us to achieve expert consensus about positive, negative, and neutral ratings of hydrodilatation in the management of frozen shoulder in a hospital setting. This should inform clinical practice and the design of an intervention for evaluation. Cite this article: Bone Jt Open 2022;3(9):701–709

Aims. Glucose-insulin-potassium (GIK) is protective following cardiac myocyte ischaemia-reperfusion (IR) injury, however the role of GIK in protecting skeletal muscle from IR injury has not been evaluated. Given the similar mechanisms by which cardiac and skeletal muscle sustain an IR injury, we hypothesized that GIK would similarly protect skeletal muscle viability. Methods. A total of 20 C57BL/6 male mice (10 control, 10 GIK) sustained a hindlimb IR injury using a 2.5-hour rubber band tourniquet. Immediately prior to tourniquet placement, a subcutaneous osmotic pump was placed which infused control mice with saline (0.9% sodium chloride) and treated mice with GIK (40% glucose, 50 U/l insulin, 80 mEq/L KCl, pH 4.5) at a rate of 16 µl/hr for 26.5 hours. At 24 hours following tourniquet removal, bilateral (tourniqueted and non-tourniqueted) gastrocnemius muscles were triphenyltetrazolium chloride (TTC)-stained to quantify percentage muscle viability. Bilateral peroneal muscles were used for gene expression analysis, serum creatinine and creatine kinase activity were measured, and a validated murine ethogram was used to quantify pain before euthanasia. Results. GIK treatment resulted in a significant protection of skeletal muscle with increased viability (GIK 22.07% (SD 15.48%)) compared to saline control (control 3.14% (SD 3.29%)) (p = 0.005). Additionally, GIK led to a statistically significant reduction in gene expression markers of cell death (CASP3, p < 0.001) and inflammation (NOS2, p < 0.001; IGF1, p = 0.007; IL-1β, p = 0.002; TNFα, p = 0.012), and a significant reduction in serum creatine kinase (p = 0.004) and creatinine (p < 0.001). GIK led to a significant reduction in IR-related pain (p = 0.030). Conclusion. Systemic GIK infusion during and after limb ischaemia protects murine skeletal muscle from cell death, kidneys from reperfusion metabolites, and reduces pain by reducing post-ischaemic inflammation. Cite this article: Bone Joint Res 2023;12(3):212–218

Aim: To determine the need for caudal epidural steroid injections to be administered with a mixture containing local anaesthetic. Patients: 100 consecutive patients listed for caudal epidural by two spinal orthopaedic consultants with lum-bosacral radiculopathic pain. 19 patients did not fulfil the criteria for the trial. Methods: Subjects randomised to either steroid injection (80mg triamcinolone) with 18mls 0.25% bupivicaine or steroid injection with 18mls Normal saline. Pre-injection maximal (Pmax) and average (Pav) pain scores and Oswestry Disability Index (ODI) scores were obtained for each patient. Pain scores were repeated at 48 hours, 2 weeks and 8 weeks with a second ODI. Results: A significant improvement in both Pav and Pmax were seen over the study period for both groups. There was no significant difference in either group for ΔPav. or ΔPmax at any stage of the study. Those patients who received a mixture containing bupivicaine underwent a significant improvement in their ODI in contrast to those who were injected with the saline mixture. There was also a significant difference in the ΔODI between groups. Conclusion: Epidural bupivicaine injection appears to enhance the effect of epidural steroid injection with adequate levels of monitoring and access to specialist support. There may be a beneficial effect on the local pain pathways by the local anaeasthetic that outlasts the direct pharmacolgical effect

Aims. To investigate the efficacy of ethylenediaminetetraacetic acid-normal saline (EDTA-NS) in dispersing biofilms and reducing bacterial infections. Methods. EDTA-NS solutions were irrigated at different durations (1, 5, 10, and 30 minutes) and concentrations (1, 2, 5, 10, and 50 mM) to disrupt Staphylococcus aureus biofilms on Matrigel-coated glass and two materials widely used in orthopaedic implants (Ti-6Al-4V and highly cross-linked polyethylene (HXLPE)). To assess the efficacy of biofilm dispersion, crystal violet staining biofilm assay and colony counting after sonification and culturing were performed. The results were further confirmed and visualized by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). We then investigated the efficacies of EDTA-NS irrigation in vivo in rat and pig models of biofilm-associated infection. Results. When 10 mM or higher EDTA-NS concentrations were used for ten minutes, over 99% of S. aureus biofilm formed on all three types of materials was eradicated in terms of absorbance measured at 595 nm and colony-forming units (CFUs) after culturing. Consistently, SEM and CSLM scanning demonstrated that less adherence of S. aureus could be observed on all three types of materials after 10 mM EDTA-NS irrigation for ten minutes. In the rat model, compared with NS irrigation combined with rifampin (Ti-6Al-4V wire-implanted rats: 60% bacteria survived; HXLPE particle-implanted rats: 63.3% bacteria survived), EDTA-NS irrigation combined with rifampin produced the highest removal rate (Ti-6Al-4V wire-implanted rats: 3.33% bacteria survived; HXLPE particle-implanted rats: 6.67% bacteria survived). In the pig model, compared with NS irrigation combined with rifampin (Ti-6Al-4V plates: 75% bacteria survived; HXLPE bearings: 87.5% bacteria survived), we observed a similar level of biofilm disruption on Ti-6Al-4V plates (25% bacteria survived) and HXLPE bearings (37.5% bacteria survived) after EDTA-NS irrigation combined with rifampin. The in vivo study revealed that the biomass of S. aureus biofilm was significantly reduced when treated with rifampin following irrigation and debridement, as indicated by both the biofilm bacterial burden and crystal violet staining. EDTA-NS irrigation (10 mM/10 min) combined with rifampin effectively removes S. aureus biofilm-associated infections both in vitro and in vivo. Conclusion. EDTA-NS irrigation with or without antibiotics is effective in eradicating S. aureus biofilm-associated infection both ex and in vivo. Cite this article: Bone Joint Res 2024;13(1):40–51

The aim was to demonstrate that day case Anterior Cruciate Ligament (ACL) reconstruction, without the use of a tourniquet, is clinically effective, cost effective, safe and “patient choice” procedure. Fifty patients who underwent day case, arthroscopic, ACL reconstruction without the use of a tourniquet, but using saline and epinephrine, pump regulated, irrigation. The same surgeon performed each case for the period May 2003 to April 2005. Seven patients had their tendons reconstructed with the use of patellar tendon grafts, the remainder, 43 patients, had hamstring tendon grafts. The study included 6 women and 44 men. This prospective study assessed cost effectiveness, clinical efficacy by measuring post-operative pain and postoperative results and finally whether this procedure remained the “patient choice”. The mean age was 30.6 years, (range 16 – 46). In addition to assessing level of immediate post operative pain the patients were also assessed at two weeks and six weeks for pain, range of movement, swelling and for the occurrence of any early post-operative complications. We were able to show that there was a significant cost benefit, approximately one third to a half in comparison to other local surgeons; that the study was clinically effective and that there were no reported early complications; and that all 50 patients would choose to have the surgery again as a day case procedure with this technique. We would like to present day case ACL reconstruction without the use of a tourniquet, as a safe option for the carefully selected patient