Search

Objective: This study sought to validate alternative pain management strategies that can reduce reliance on opioids for postoperative pain management in otology. Study Design: Prospective cohort study. Setting: Single tertiary‐care facility. Methods: Adult patients who underwent outpatient otologic surgery from September 2021 to July 2022 were randomized into treatment cohorts. The opioid monotherapy cohort received a standard opioid prescription. The multimodal analgesia cohort received the same opioid prescription, prescriptions for acetaminophen and naproxen, and additional pain management education with a flyer on discharge. All patients completed a questionnaire 1 week after surgery to evaluate opioid usage and pain scores. Results: Eighty‐six patients completed the study. The opioid monotherapy cohort (n = 42) and multimodal analgesia cohort (n = 44) were prescribed an average of 42.1 ± 20.4 morphine milligram equivalents (MME) and 38.4 ± 5.7 MME, respectively (p = 0.373). Four patients (9.52%) in the opioid monotherapy cohort required opioid refills compared to 1 patient (2.27%) in the multimodal analgesia cohort (p = 0.156). Multivariate analysis demonstrated that the multimodal analgesia cohort consumed significantly fewer opioids on average than the opioid monotherapy cohort (11.9 ± 15.9 MME vs 22.8 ± 28.0 MME, respectively). There were no significant differences in postoperative rehospitalizations (p = 0.317) or Emergency Department visits (p = 0.150). Pain scores on the day of surgery, postoperative day (POD) 1, POD3, and POD7 were not significantly different between cohorts (p = 0.395, 0.896, 0.844, 0.765, respectively). Conclusion: The addition of patient education, acetaminophen, and naproxen to postoperative opioid prescriptions significantly reduced opioid consumption without affecting pain scores, refill rates, or complication rates after otologic surgery. [ABSTRACT FROM AUTHOR]

Objective: Specific guidelines regarding an optimal general anesthesia (GA) approach to obstructive sleep apnea (OSA) patients remain undefined. Literature comparing the efficacy of total intravenous anesthesia (TIVA) and inhalational anesthesia in this population is sparse. We hypothesize that OSA patients receiving TIVA will experience reduced recovery times and other improved post‐surgical outcomes. Study Design: Randomized controlled trial. Methods: Adult OSA patients undergoing upper airway surgery (hypoglossal nerve stimulation [HNS], nasal, or palate surgery) from February 2020–December 2020 were included. A post‐anesthesia care unit (PACU) nursing survey documented patients' alertness, pain, oxygen supplementation, and postoperative nausea and vomiting from PACU arrival to 2 hours. Perioperative timepoints from the electronic medical record (EMR) and a nurse‐estimated Phase I recovery time were collected. Results: One hundred eleven patients were included (46 TIVA and 65 inhalational anesthesia). Per EMR‐recorded timepoints, TIVA patients undergoing HNS and palate surgery experienced Phase I Time reductions of 12.5 min (p = 0.042) and 27.5 min (p = 0.016), respectively. Per the PACU survey, TIVA patients undergoing any surgery, HNS, or palate surgery experienced nurse‐estimated Phase I Time reductions of 16.5 min (p = 0.004), 12.5 min (p = 0.031), and 38.5 min (p = 0.024), respectively. Overall, TIVA patients experienced higher alertness and pain ratings, and lower oxygen supplementation requirements from PACU arrival to 30 min (p < 0.05). Conclusion: Patients with OSA receiving TIVA for GA maintenance during upper airway procedures experienced reduced recovery times and oxygen supplementation requirements, and a more rapid return to alertness. Future work toward developing optimized anesthetic guidelines for OSA patients is merited. Level of Evidence: 3 Laryngoscope, 133:984–992, 2023 [ABSTRACT FROM AUTHOR]

Objectives: To compare cost and time spent in surgical and postoperative courses in patients with obstructive sleep apnea (OSA) undergoing surgery with either total intravenous anesthesia (TIVA) or inhalational anesthesia. Study Design: Retrospective chart review. Methods: Retrospective review on patients undergoing surgery for OSA under general anesthesia from January 2019 to October 2020. Cost per service was acquired for the day of surgery. Results: A total of 230 patients were included: 95 received TIVA; 135 received inhalation anesthesia. Total cost was significantly higher in the TIVA nasal surgery group by $286 (P =.035). TIVA produced significantly higher pharmacy and operating room costs across all surgeries and OSA severities. These increased costs were offset by significantly lower supply costs in upper airway stimulator (UAS, −$419.50; P =.007) and uvulopalatopharyngoplasty (UPPP, −$115.16; P =.015) patients receiving TIVA. In the TIVA cohort, there was a trend toward lower recovery room costs after UAS (−$111.09; P =.063) and nasal surgery (−$64.45; P =.096) and anesthesia costs after nasal surgery (−$36.67; P =.054). Total recovery time was reduced by 18 minutes (P =.004) for nasal surgery, 25 minutes (P =.043) for UAS, and 27 minutes (P =.147) for UPPP patients receiving TIVA. Conclusion: When used in an outpatient setting for patients with OSA, TIVA adds to pharmacy and operating room costs, but this is usually offset by lower supply, anesthesia, and recovery room costs. We found decreased recovery times in the TIVA cohort. TIVA has proven benefits in patient outcomes and can be cost‐effective in OSA surgery. Level of Evidence: 3 Laryngoscope, 132:1487–1494, 2022 [ABSTRACT FROM AUTHOR]

Objectives: Mid and upper face free flaps frequently are associated with challenges due to pedicle length. We sought to evaluate the frequency at which alternative pedicle maneuvers were required for these reconstructions and determine if there was any association with flap survival or postoperative complications. Study Design: Retrospective review at three tertiary care institutions. Methods: Database review. Results: Free flap reconstruction of the upper and midface was performed in 295 patients (108 bony, 187 soft tissue). In 82% of cases, the vessels reached the ipsilateral neck for anastomosis to traditional target vessels. Arterial grafts were required in 2% of reconstructions (4% bony and 1% soft tissue). Venous grafting was required in 7% of reconstructions (21% fibula, 16% scapula, and 3% soft tissue) and was associated with an increase in flap failure rate (19% vs 3%, P =.003). The most common recipient artery for revascularization was the cervical facial artery (78%). Alternate recipient vessels were selected in 13% of cases, including the superficial temporal vessels (7%), distal facial branches through a separate facial incision (4%), and angular vessels (2%). Vein grafting was associated with a higher flap failure rate. Alternative maneuvers did not affect need for intraoperative pedicle revision or complications. Conclusions: In upper and midface reconstruction, vascular grafting, targeting more distal branches of the facial system, or additional maneuvers to optimize pedicle orientation is often required to secure revascularization. Vein grafting is associated with a higher free flap failure rate. Scapular border flaps often require vascular grafting or atypical anastomotic locations. Level of Evidence: 3—Non randomized cohort study 4 Laryngoscope, 131:2465–2470, 2021 [ABSTRACT FROM AUTHOR]

Background: Head and neck surgical oncology and reconstruction are uniquely suited to address burdens of disease in underserved areas. Since these efforts are not well known in our specialty, we sought to understand global outreach throughout our society of surgeons. Methods: Survey distributed to members of the American Head and Neck Surgery involved in international humanitarian head and neck surgical outreach trips. Results: Thirty surgeons reported an average of seven trips to over 70 destinations. Identification of candidates, finances, on‐site patient care, complications, long‐term post‐surgical care, ethics, and educational goals are reported. We report a success rate of 90% on 125 free flaps performed in these settings. Conclusions: The effort to answer the call for alleviating the global burden of surgical disease is strong within our specialty. There is a shared focus on humanitarian effort and teaching. Ethics of high resource surgeries such as free flap reconstruction remains controversial. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: The literature on outcomes of end‐to‐side (ETS) anastomoses for microvascular reconstruction of the head and neck is limited. This series reviews ETS in free tissue transfer (FTT) across multiple institutions to better understand their usage and associated outcomes. Study Design: Retrospective review of 2482 consecutive patients across three tertiary institutions. Methods: Adult patients (> 18) who received a FTT from 2006 to 2019 were included. Results: Two hundred and twenty‐one FTT were identified as requiring at least one ETS anastomosis. These ETS cases had a failure rate of 11.2% in comparison to 3.8% in a cohort of end‐to‐end (ETE) cases (P <.001). ETS cases were significantly more likely to have a prior neck dissection (P <.001), suggesting the ETS method was utilized in select circumstances. A second ETS anastomosis improved survival of the FTT (P =.006), as did utilization of a coupler over suture (P =.002). Failure due to venous thrombosis was significantly more common with one ETS anastomosis instead of two ETS anastomoses (P =.042). Conclusions: ETS is effective but is often used as a secondary technique when ETE is not feasible; as such, in this series, ETS was associated with higher failure. A second anastomosis and the use of the coupler for completing the anastomoses were associated with lower rates of failure. Level of Evidence: 3 Laryngoscope, 131:1286–1290, 2021 [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: Predictors of free tissue transfer (FTT) failure and the need for postoperative revision (POR) have been extensively studied; however, there are little data evaluating outcomes when intraoperative revision (IOR) at initial surgery is required. This study seeks to better understand the impact IOR of the pedicle has on FTT outcomes. Study Design: Retrospective review of 2482 consecutive patients across three tertiary institutions. Methods: Adult patients (>18) who received a FTT and underwent anastomotic revision from 2006 to 2019 were included. Logistic regression was performed to predict revision, and recursive partitioning was performed to classify risk of failure based on type of revision and vessels revised. Results: Failure rates for IOR (19%) and POR (27%) were higher compared to a nonrevised failure rate of 2% (P <.01 and P <.01, respectively). Intraoperative venous revision (IORv, n = 13), arterial (IORa, n = 114), and both (IORb, n = 11) were associated with failure rates of 8% (odds ratio [OR] 3.5, P =.23), 18% (OR = 9.0, P <.01), 45% (OR = 35.3, P = <.01), respectively. Arterial revision was most common among IOR (83%, P <.01). Postoperative venous revision (PORv, n = 35), arterial (PORa, n = 36), and both (PORb, n = 11) were associated with failure rates of 20% (OR = 15.7, P <.01), 27% (OR = 10.6, P <.01), and 39% (OR = 27.0, P <.01), respectively. Failure rate for flaps that had POR after IOR (PORi, n = 11) was 45% (OR = 18.2, P <.01). Diabetes predicted IOR (P =.006); tobacco use, heavy alcohol use, and prior radiation predicted POR (P =.01, P =.05, and P =.01, respectively). Conclusion: Both IOR and POR were associated with increased failure compared to nonrevised flaps. The risk of failure increases sequentially with intraoperative or POR of the vein, artery, or both vessels. Revision of both vessels and POR after IOR are strongly predictive of failure. Level of Evidence: 3 Laryngoscope, 131:1035–1041, 2021 [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: There is currently no standard of care in terms of anesthesia modality for patients receiving upper airway surgery with comorbid obstructive sleep apnea (OSA). Although both total intravenous anesthesia (TIVA) and volatile gas anesthesia are commonly utilized in ambulatory otolaryngology surgery, it is currently unclear if there are any advantages with one modality over the other. We hypothesize that patients receiving upper airway surgery with comorbid OSA will have quicker recovery times with TIVA. Study Design: Retrospective chart review from January 2019 to December 2019. Methods: All patients aged 18 and older receiving upper airway surgery (upper airway stimulation, nasal surgery, modified uvulopalatopharyngoplasty) were included. Patients were excluded when there was incomplete or missing data in the electronic medical record. Results: Eighty‐six patients received gas anesthesia and 62 patients received TIVA. Phase I recovery times were significantly reduced by surgery and by severity of OSA: nasal surgery, upper airway stimulation, and modified uvulopalatopharyngoplasty had a reduction of 35.5 minutes (P <.001), 42.5 minutes (P <.001), and 36 minutes (P =.022), respectively. In terms of severity, mild, moderate, and severe OSA had reductions of 23.5 minutes (P =.004), 52 minutes (P =.004), and 47 minutes (P <.001), respectively. The severity of OSA generally correlated with increased time spent in Phase I: as severity increased, Phase I time increased by 16.8 minutes for the gas cohort (P <.001), whereas in the TIVA cohort, it increased only 4.3 minutes (P =.489). Conclusion: Patients having upper airway surgery with comorbid OSA that received TIVA (propofol and remifentanil) spent significantly less time in Phase I and the recovery room overall compared to those receiving volatile gas anesthesia in the form of sevoflurane, and this correlated with the severity of OSA. Level of Evidence: 3. Laryngoscope, 131:925–931, 2021 [ABSTRACT FROM AUTHOR]

Background: Recent studies have shown that fluoroquinolones, specifically, enrofloxacin and its active metabolite (ciprofloxacin), cross the equine placenta without causing gross or histological lesions in the first and third trimester fetuses or resulting foal. However, it is possible that in utero exposure to fluoroquinolones may cause subtle lesions not detectable by standard means; thus, a more in‐depth assessment of potential toxicity is warranted. Objectives: To use quantitative magnetic resonance imaging (qMRI), biomechanical testing, and chondrocyte gene expression to evaluate the limbs of foals exposed to enrofloxacin during the third trimester of pregnancy. Study design: In vivo and control terminal experiment. Methods: Healthy mares at 280 days gestation were assigned into three groups: untreated (n = 5), recommended therapeutic (7.5 mg/kg enrofloxacin, PO, SID, n = 6) or supratherapeutic (15 mg/kg, PO, SID, n = 6) doses for 14 days. Mares carried and delivered to term and nursed their foals for ~30 days. Two additional healthy foals born from untreated mares were treated post‐natally with enrofloxacin (10 mg/kg PO, SID, for 5 days). By 30 days, foal stifles, hocks, elbows, and shoulders were radiographed, foals were subjected to euthanasia, and foal limbs were analysed by quantitative MRI, structural MRI, biomechanical testing and chondrocyte gene expression. Results: Osteochondral lesions were detected with both radiography and structural MRI in foals from both enrofloxacin‐treated and untreated mares. Severe cartilage erosions, synovitis and joint capsular thickening were identified in foals treated with enrofloxacin post‐natally. Median cartilage T2 relaxation times differed between joints but did not differ between treatment groups. Main limitations: A small sample size was assessed and there was no long‐term follow‐up. Conclusion: While further research is needed to address long‐term foal outcomes, no differences were seen in advanced imaging, biomechanical testing or gene expression by 30 days of age, suggesting that enrofloxacin may be a safe and useful antibiotic for select bacterial infections in pregnant mares. [ABSTRACT FROM AUTHOR]

Background: Understanding factors impacting successful salvage of a compromised free flap. Methods: Multi‐institutional review of free flap reconstructions for head and neck defects (n = 1764). Results: Free flap compromise rate: 9% (n = 162); 46% salvaged (n = 74). Higher salvage rates in initial 48 hours (64%) vs after (30%; P <.001). Greater compromise (14%) and failure (8%) if inset challenging vs straightforward (6% compromise, 4% failure; P =.035). Greater compromise (23%) and failure (17%) following intraoperative anastomosis revision vs no revision (7% compromise, 4% failure; P <.0001). Success following arterial insufficiency was lower (60% failed, 40% salvaged) vs venous congestion (23% failed, 77% salvaged) (P <.0001). Greater flap salvage following thrombectomy (66%) vs no thrombectomy (34%; P <.0001). Greater flap salvage if operative duration ≤8 hours (57%), vs >8 hours (40%) (P =.04). Conclusions: There were higher rates of free flap salvage if the vascular compromise occurred within 48 hours, if due to venous congestion, if operative duration ≤8 hours, and if the anastomosis did not require intraoperative revision. [ABSTRACT FROM AUTHOR]

Considerable support exists for both the phonological core deficit and the naming speed deficit models of dyslexia. The double deficit model proposed that many students with dyslexia might also be impaired in both underlying processes. Employing either performance thresholds (i.e., scores below the 16th or 25th percentile) or k-means clustering as classification methods, the current study investigated whether 154 young adolescents with dyslexia could be categorized into subtypes according to the presence or absence of phonological deficits alone, naming speed deficits alone, or a combination of the two and whether group composition changed depending on classification method. Results support the existence of both single and double deficit groups and confirm that those with both deficits are the most severely impaired across multiple measures. Contrary to previous research, most adolescents were classified as either naming speed only (about a third of the group) or double deficit when defining impairment using performance thresholds to classify groups. This may suggest that although early phonological deficits are amenable to remediation, identification of language symbols fails to become automatized in most individuals with dyslexia and may require more targeted intervention. Classification differences reported in the literature may depend on age and methods employed for classification. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Pulsed‐electromagnetic field (PEMF) devices are marketed and utilized for the non‐chemical management of biofouling, with little scientific validation of their effectiveness. Proof‐of‐principle studies were carried out previously to systematically investigate the effect of two such commercial devices on the culturability of bacteria under controlled static (i.e. non‐flowing) conditions and anti‐microbial effects were demonstrated. However, such effects were small and an expanded investigation, using these devices and including the effect of flow, was deemed necessary. RESULTS: The effect of the electromagnetic fields generated by the same two commercial devices on the bacterial culturability of Escherichia coli and Pseudomonas fluorescens under flow conditions has been contrasted with previous static results. It has been found that the effectiveness of PEMF exposure depends on waveform, extent of flow, type of bacteria and PEMF exposure duration. CONCLUSION: Both stimulatory and inhibitory effects are observed that are uniquely dependent upon device type (i.e. a range of parameters including waveform), species of microorganism, presence and degree of flow and PEMF exposure time. For both devices and both microorganisms, stimulatory effects are uniformly observed for one device under static conditions and inhibitory effects are uniformly observed for the other device at low flow and for the former at high flow. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Accessibility to health care, especially complex surgical care, represents one of the major health care disparities in developing countries. While surgical teams may be willing to travel to these areas to help address these needs, there are many logistical and ethical dilemmas inherent in this pursuit. We reviewed our approach to the establishment of the team-based surgical outreach program, wherein we perform head and neck free tissue transfer surgery in Haiti. We describe the challenges encountered in the delivery of surgical care as well as ethical dilemmas relevant to surgical outreach trips, highlighting an approach reliant on strong local cooperation. Despite the obstacles in place, our experience shows that free flap surgery can be successfully and ethically performed in these areas of great need. [ABSTRACT FROM AUTHOR]

Long-term depression (LTD), a widely studied form of activity-dependent synaptic plasticity, is typically induced by prolonged low-frequency stimulation (LFS). Interestingly, LFS is highly effective in eliciting LTD in vitro, but much less so under in vivo conditions; the reasons for the resistance of the intact brain to express LTD are not well understood. We examined if levels of background electrocorticographic (ECoG) activity influence LTD induction in the thalamocortical visual system of rats under very deep urethane anesthesia, inducing a brain state of reduced spontaneous cortical activity. Under these conditions, LFS applied to the lateral geniculate nucleus resulted in LTD of field postsynaptic potentials (fPSPs) recorded in the primary visual cortex (V1). Pairing LFS with stimulation of the brainstem (pedunculopontine) reticular formation resulted in the appearance of faster, more complex activity in V1 and prevented LTD induction, an effect that did not require muscarinic or nicotinic receptors. Reticular stimulation alone (without LFS) had no effect on cortical fPSPs. These results show that excitation of the brainstem activating system blocks the induction of LTD in V1. Thus, higher levels of neural activity may inhibit depression at cortical synapses, a hypothesis that could explain discrepancies regarding LTD induction in previous in vivo and in vitro work. [ABSTRACT FROM AUTHOR]

ABSTRACT Tendinitis is a common and a performance-limiting injury in athletes. This study describes the value of intralesional tendon-derived progenitor cell (TDPC) injections in equine flexor tendinitis. Collagenase-induced tendinitis was created in both front superficial digital flexor (SDF) tendons. Four weeks later, the forelimb tendon lesions were treated with 1 × 107 autogenous TDPCs or saline. Tendinitis was also induced by collagenase in one hind SDF tendon, to study the survival and distribution of DiI-labeled TDPCs 1, 2, 4, and 6 weeks after injection. The remaining normal tendon was used as a 'control.' Twelve weeks after forelimb TDPC injections, tendons were harvested for assessment of matrix gene expression, biochemical, biomechanical, and histological characteristics. DiI-labeled TDPCs were abundant 1 week after injection but gradually declined over time and were undetectable after 6 weeks. Twelve weeks after TDPC injection, collagens I and III, COMP and tenomodulin mRNA levels were similar ( p = 0.3) in both TDPC and saline groups and higher ( p < 0.05) than normal tendon. Yield and maximal stresses of the TDPC group were significantly greater ( p = 0.005) than the saline group's and similar ( p = 0.6) to normal tendon. However, the elastic modulus of the TDPC and saline groups were not significantly different ( p = 0.32). Histological assessment of the repair tissues with Fourier transform-second harmonic generation imaging demonstrated that collagen alignment was significantly better ( p = 0.02) in TDPC group than in the saline controls. In summary, treating collagenase-induced flexor tendon lesions with TDPCs improved the tensile strength and collagen fiber alignment of the repair tissue. Study Design © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2162-2171, 2016. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells have been identified in the synovial fluid of several species. This study was conducted to characterize chondroprogenitor (CP) cells in equine synovial fluid (SF) and to determine the effect of fibroblast growth factor 2 (FGF-2) on SF-CP monolayer proliferation and subsequent chondrogenesis. We hypothesized that FGF-2 would stimulate SF-CP proliferation and postexpansion chondrogenesis. SF aspirates were collected from adult equine joints. Colony-forming unit (CFU) assays were performed during primary cultures. At first passage, SF-cells were seeded at low density, with or without FGF-2. Following monolayer expansion and serial immunophenotyping, cells were transferred to chondrogenic pellet cultures. Pellets were analyzed for chondrogenic mRNA expression and cartilage matrix secretion. There was a mean of 59.2 CFU/mL of SF. FGF-2 increased the number of population doublings during two monolayer passages and halved the population doubling times. FGF-2 did not alter the immunophenotype of SF-CPs during monolayer expansion, nor did FGF-2 compromise chondrogenesis. Hypertrophic phenotypic markers were not expressed in control or FGF-2 groups. FGF-2 did prevent the development of a “fibroblastic” cell layer around pellet periphery. FGF-2 significantly accelerates in vitro SF-CP expansion, the major hurdle to clinical application of this cell population, without detrimentally affecting subsequent chondrogenic capacity. [ABSTRACT FROM AUTHOR]

Equine carpal sheath effusion has multiple etiologies. The purpose of this retrospective study was to describe the prevalence of distinct musculoskeletal lesions lameness in a sample of horses with a clinical diagnosis of carpal sheath effusion. A total of 121 horses met inclusion criteria. Seventy-four percent (89/121) of horses were lame at presentation; middle-aged (9-18 years, 80%) and older (> 18 years, 85%) horses were lame more frequently than young horses (< 9 years, 44%). Ninety-three percent (113/121) were diagnosed with osseous and/or soft tissue abnormalities. Of these 113 horses, 10 exhibited osseous abnormalities, whereas 111 were diagnosed with soft tissue lesions. Eighty-four percent (93/111) of the soft tissue injuries extended from the caudodistal antebrachium to the palmar metacarpus. The superficial digital flexor tendon (98/111; 88%) and accessory ligament of the superficial digital flexor tendon (64/111; 58%) were the most commonly injured structures, with both structures affected in 41 (41/111; 37%) horses. Injuries within the caudodistal antebrachium included the superficial digital flexor musculotendinous junction (66), the accessory ligament of the superficial digital flexor tendon (64), and deep digital flexor muscle (21), in isolation or in combination with other structures. Increased echogenicity in the medial superficial digital flexor musculotendinous junction was detected in 40 horses and was significantly associated with increasing age (middle-aged, 19/40; old, 18/40). Findings from this study indicated that age should be taken into consideration for horses presented with carpal sheath effusion and that adjacent structures within the caudodistal antebrachium should be included in evaluations. [ABSTRACT FROM AUTHOR]

Bacterial endotoxin may contribute to aseptic loosening of orthopedic implants even in the absence of clinical or microbiological evidence of infection. One potential source of endotoxin during aseptic loosening is systemically circulating endotoxin, derived from intestinal flora, minor infections, or dental procedures, that may bind to wear particles. The current study demonstrates that systemically derived endotoxin accumulates when 'endotoxin-free' titanium and polyethylene particles are implanted on murine calvaria. Time-course experiments and experiments using germ-free mice rule out the possibility that the observed endotoxin accumulation may be due to bacterial contamination. In contrast, endotoxin is cleared from titanium particles that originally carry high amounts of adherent endotoxin. The mechanism of endotoxin clearance is not dependent on induction of a respiratory burst. Taken together, these results indicate that a balance between endotoxin accumulation and endotoxin clearance controls the steady-state level of endotoxin surrounding orthopedic wear particles implanted on murine calvaria. This balance may regulate the rate of osteolysis in the murine calvaria model as well as in patients with aseptic loosening. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007 [ABSTRACT FROM AUTHOR]