Ultrasound-Guided Percutaneous Cryoneurolysis for Perioperative Analgesia Following Major Lower Extremity Amputation: A Randomized, Participant- and Observer-Masked, Sham-Controlled Pilot Study.

BACKGROUND: Extremity amputations are associated with pain in both the residual limb and the phantom limb. This pain, which is often debilitating, may be prevented by excellent perioperative pain control. Ultrasound-guided percutaneous cryoneurolysis is an analgesic modality offering pain control for weeks or months following surgery. This treatment has not been compared to the sham procedure for large nerves (e.g., femoral and sciatic) to provide preoperative analgesia. We therefore conducted a randomized, controlled pilot study to evaluate the use of this modality for the treatment of pain following amputation to (1) determine the feasibility of and optimize the study protocol for a subsequent definitive clinical trial; and (2) estimate analgesia and opioid reduction within the first postoperative weeks. METHODS: A convenience sample of seven patients undergoing lower extremity amputation were randomized to receive either active cryoneurolysis or a sham procedure targeting the sciatic and femoral nerves in a participant-masked fashion. This was a pilot study with a relatively small number of participants, and therefore the resulting data were not analyzed statistically. RESULTS: Compared to the participants who received sham treatment (n=3), those who underwent active cryoneurolysis (n=4) reported lower pain scores and decreased opioid consumption at nearly all time points between days one and 21 following amputation. CONCLUSIONS: Ultrasound-guided percutaneous cryoneurolysis of the femoral and sciatic nerves prior to lower extremity amputation appears feasible and potentially effective. The data from this pilot study may be used to power a definitive randomized clinical trial.

Fracture blisters: predictors for time to definitive fixation in pilon fractures.

PURPOSE: Fracture blisters, a common soft-tissue complication of pilon fractures, are associated with post-operative wound infections, delays in definitive fixation, and alterations in surgical plan. The purpose of this study was to (1) identify the delay in surgery attributable to the presence fracture blisters and (2) investigate the relationship of fracture blisters to comorbidities and fracture severity. METHODS: Patients with pilon fractures at an urban level 1 Trauma center from 2010 to 2021 were identified. The presence or absence of fracture blisters was noted, along with location. Demographic information, time from injury to external fixator placement, and time to definitive open reduction internal fixation (ORIF) were collected. Pilon fractures were classified according to AO/OTA guidelines using CT imaging and plain radiographs. RESULTS: 314 patients with pilon fractures were available for analysis, eighty (25%) of whom were found to have fracture blisters. Patients with fracture blisters had longer time to surgery compared to those without fracture blisters (14.2 days vs 7.9 days, p < 0.001). A greater proportion of patients with fracture blisters had AO/OTA 43C fracture patterns, compared with those without fracture blisters (71.3% vs 53.8%, p = 0.03). Fractures blisters were less likely to be localized over the posterior ankle (12%, p = 0.007). CONCLUSION: The presence of fracture blisters in pilon fractures are associated with significant delays in time to definitive fixation and higher energy fracture patterns. Fracture blisters are less commonly located over the posterior ankle which may support the implementation of a staged posterolateral approach when managing these injures.

Reduction of Opioid Consumption After Outpatient Orthopaedic Trauma Surgeries Using a Multimodal Pain Protocol.

INTRODUCTION: Because of the dearth of literature in the orthopaedic trauma population, we aimed to analyze how a multimodal pain protocol after outpatient surgery affects opioid consumption, pain scores, and patient satisfaction. METHODS: This was a cohort study with a historical control at an urban level 1 trauma center. Forty consecutive outpatients were given a peripheral nerve block and a multimodal pain protocol between September 2019 and March 2020 and compared with 70 consecutive preprotocol patients who received a peripheral nerve block and hydrocodone-acetaminophen. The primary outcome was morphine milligram equivalents (MMEs) consumed. Our secondary aims were pain scores and satisfaction. RESULTS: Patients in the protocol were younger (36.45 versus 45.09 years, P = 0.007), butthere was no difference in sex, body mass index, American Society of Anesthesiologists, or surgical duration. There was a 59% reduction in opioids consumed in the first 4 days after surgery (3.83 MME versus 9.29 MME, P < 0.001). At the postoperative day-14 time point, protocol patients consumed a total of 5.59 MMEs, which is 40% less than just the first 4 days of the preprotocol (P = 0.02). Protocol patients assigned a higher rating of "least pain" on postoperative day 1 (1.24 versus 0.52, P = 0.04) but had higher satisfaction scores on day 1 (9.68 versus 8.54, P < 0.001) and day 2 (9.66 versus 8.61, P < 0.001). CONCLUSION: Implementation of a multimodal pain management protocol after outpatient orthopaedic trauma surgeries reduced opioid consumption by >50% in the first 4 days postoperatively. Additional studies are needed to refine the multimodal pain protocol used in this study. LEVEL OF EVIDENCE: II.

Characterization of electric scooter injuries over 27 months at an urban level 1 trauma center.

BACKGROUND: Electric scooters (e-scooters) have become a widespread method of transportation. The purpose of this study is to provide risk stratification tools for modifiable risk factors associated with e-scooter injury morbidity. METHODS: Patients at an urban Level 1 Trauma center sustaining e-scooter injuries between November 2017 through March 2020 were identified. Primary outcomes of interest were major trauma, as defined by an Injury Severity Score (ISS) >15, or hospital admission. RESULTS: A total of 442 patients sustained orthopaedic (51%), facial (31%), cranial (13%), and chest/abdominal injuries (4.5%). Rate of helmet use was 2.5%, hospital admission was 40.7%, and intensive care was 3%. Patients with facial injuries were half as likely to sustain major trauma as compared to orthopaedic injuries (p < 0.05). Factors with higher likelihood of hospital admission included age > 40 years (OR 4.20, p < 0.01), alcohol or other substance intoxication (OR 4.14 and 9.87, p < 0.001), loss of consciousness (OR 2.72, p < 0.003), or transport to the hospital by ambulance (OR 4.47, p < 0.001). CONCLUSIONS: There is a substantial proportion of major trauma within e-scooter injuries. Modifiable risk factors for hospital admission include use of head protection and substance use while riding e-scooters.

Financial impact of electric scooters: a review of injuries over 27 months at an urban level 1 trauma center (cost of e-scooter injuries at an urban level 1 trauma center).

BACKGROUND: Electric scooters (e-scooters) have become a widespread method of transportation due to convenience and affordability. However, the financial impact of medical care for sustained injuries is currently unknown. The purpose of this study is to characterize total billing charges associated with medical care of e-scooter injuries. METHODS: A retrospective review of patients with e-scooter injuries presenting to the trauma bay, emergency department or outpatient clinics at an urban level 1 trauma center was conducted from November 2017 to March 2020. Demographic and clinical data were collected. Primary outcomes of interest were total billing charges and billing to insurance (hospital and professional). Multivariable models were used to identify preventable risk factors associated with higher total billing charges. RESULTS: A total of 63 patients were identified consisting of 42 (66.7%) males, average age 40.19 (SD 13.29) years and 3.2% rate of helmet use. Patients sustained orthopedic (29%, n=18), facial (48%, n=30) and cranial (23%, n=15) injuries. The average total billing charges for e-scooter clinical encounters was $95 710 (SD $138 215). Average billing to insurance was $86 376 (SD $125 438) for hospital charges and $9 334 (SD $14 711) for professional charges. There were no significant differences in charges between injury categories. On multivariable regression, modifiable risk factors independently associated with higher total billing charges included any intoxication prior to injury ($231 377 increase, p=0.02), intracranial bleeds ($75 528, p=0.04) and TBI ($360 898, p=0.006). DISCUSSION: Many patients sustain high-energy injuries during e-scooter accidents with significant medical and financial consequences. Further studies may continue expanding the financial impact of e-scooter injuries on both patients and the healthcare system. LEVEL OF EVIDENCE: III.

Electric Scooter Orthopaedic Injury Demographics at an Urban Level I Trauma Center.

OBJECTIVES: This study highlights demographics and orthopaedic injuries of electric scooter-related trauma that presented to our institution over a 27-month period. DESIGN: Retrospective review. SETTING: Urban Level 1 trauma center. PATIENTS: Patients presenting to the emergency department, trauma bay, or outpatient clinic after electric scooter injury were identified from November 2017 through January 2020 using ICD-10 diagnosis codes. MAIN OUTCOMES: Patient charts were reviewed for demographics, injury characteristics, imaging, treatment, perioperative data, and Injury Severity Scores. RESULTS: Four hundred eighty-five patients presented during the study period. Of these, 44% had orthopaedic injuries, including 30% with pelvis or extremity fractures. There were 21 (10%) polytraumatized patients in the orthopaedic cohort. The age ranged from 16 to 79 years (average 36 years), with 58% men, and 18% were visitors from out of town. Of 49 patients requiring orthopaedic surgery, 8 underwent surgery on an urgent basis. The average Injury Severity Score for orthopaedic patients was 8.4 with a median of 5.0 for nonoperative injuries versus a significantly higher median of 16.0 for operative injuries. Twenty-nine percent of patients were intoxicated and only 2% wore a helmet. CONCLUSIONS: Electric scooter injuries are increasing, and many patients sustain high-energy injuries. As electric scooter use continues to increase, the prevalence of orthopaedic injuries is also likely to rise. Further studies are needed to fully understand the impact scooter-related injuries have on individual patients and the health care system. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

What Was the Change in Telehealth Usage and Proportion of No-show Visits for an Orthopaedic Trauma Clinic During the COVID-19 Pandemic?

BACKGROUND: In response to the coronavirus disease 2019 (COVID-19) pandemic, the Centers for Medicare and Medicaid Services pledged payment for telehealth visits for the duration of this public health emergency in an effort to decrease COVID-19 transmission and allow for deployment of residents and attending physicians to support critical-care services. Although the COVID-19 pandemic has vastly expanded telehealth use, no studies to our knowledge have analyzed the implementation and success of telehealth for orthopaedic trauma. This population is unique in that patients who have experienced orthopaedic trauma range in age from early childhood to late adulthood, they vary across the socioeconomic spectrum, may need to undergo emergent or urgent surgery, often have impaired mobility, and, historically, do not always follow-up consistently with healthcare providers. QUESTIONS/PURPOSES: (1) To what extent did telehealth usage increase for an outpatient orthopaedic trauma clinic at a Level 1 trauma center from the month before the COVID-19 stay-at-home order compared with the month immediately following the order? (2) What is the proportion of no-show visits before and after the implementation of telehealth? METHODS: After nonurgent clinic visits were postponed, telehealth visits were offered to all patients due to the COVID-19 stay-at-home order. Patients with internet access who had the ability to download the MyChart application on their mobile device and agreed to a telehealth visit were seen virtually between March 16, 2020 and April 10, 2020 (COVID-19) by three attending orthopaedic trauma surgeons at a large, urban, Level 1 trauma center. Clinic schedules and patient charts were reviewed to determine clinical volumes and no-show proportions. The COVID-19 period was compared with the 4 weeks before March 16, 2020 (pre-COVID-19), when all visits were conducted in-person. The overall clinic volume decreased from 340 to 233 (31%) between the two periods. The median (range) age of telehealth patients was 46 years (20 to 89). Eighty-four percent (72 of 86) of telehealth visits were postoperative and established nonoperative patient visits, and 16% (14 of 86) were new-patient visits. To avoid in-person suture or staple removal, patients seen for their 2-week postoperative visit had either absorbable closures, staples, or nonabsorbable sutures removed by a home health registered nurse or skilled nursing facility registered nurse. If radiographs were indicated, they were obtained at outside facilities or our institution before patients returned home for their telehealth visit. RESULTS: There was an increase in the percentage of office visits conducted via telehealth between the pre-COVID-19 and COVID-19 periods (0% [0 of 340] versus 37% [86 of 233]; p < 0.001), and by the third week of implementation, telehealth comprised approximately half of all clinic visits (57%; [30 of 53]). There was no difference in the no-show proportion between the two periods (13% [53 of 393] for the pre-COVID-19 period and 14% [37 of 270] for the COVID-19 period; p = 0.91). CONCLUSIONS: Clinicians should consider implementing telehealth strategies to provide high-quality care for patients and protect the workforce during a pandemic. In a previously telehealth-naïve clinic, we show successful implementation of telehealth for a diverse orthopaedic trauma population that historically has issues with mobility and follow-up. Our strategies include postponing long-term follow-up visits, having sutures or staples removed by a home health or skilled nursing facility registered nurse, having patients obtain pertinent imaging before the visit, and ensuring that patients have access to mobile devices and internet connectivity. Future studies should evaluate the incidence of missed infections or stiffness as a result of telehealth, analyze the subset of patients who may be more vulnerable to no-shows or technological failures, and conduct patient surveys to determine the factors that contribute to patient preferences for or against the use of telehealth. LEVEL OF EVIDENCE: Level III, therapeutic study.

Antibiotic-Impregnated Intramedullary Cement Nail-Induced Acute Generalized Exanthematous Pustulosis and Septic Shock: A Case Report.

CASE: A 28-year-old woman with an infected proximal femur nonunion was treated with an antibiotic-coated intramedullary nail. Shortly after discharge, the patient presented to the emergency department and was readmitted with a morbilliform rash sparing the left lower extremity. She became hemodynamically unstable, despite cessation of intravenous antibiotics, requiring transfer to the intensive care unit and urgent removal of her antibiotic nail. She improved after surgery, and biopsy results from the rash confirmed acute generalized examthematous pustulosis. CONCLUSION: Acute generalized exanthematous pustulosis is a rare, dermatologic crisis that can be precipitated by antibiotics, even in the form of antibiotic cement.

Stiff muscle fibers in calf muscles of patients with cerebral palsy lead to high passive muscle stiffness.

Cerebral palsy (CP), caused by an injury to the developing brain, can lead to alterations in muscle function. Subsequently, increased muscle stiffness and decreased joint range of motion are often seen in patients with CP. We examined mechanical and biochemical properties of the gastrocnemius and soleus muscles, which are involved in equinus muscle contracture. Passive mechanical testing of single muscle fibers from gastrocnemius and soleus muscle of patients with CP undergoing surgery for equinus deformity showed a significant increase in fiber stiffness (p<0.01). Bundles of fibers that included their surrounding connective tissues showed no stiffness difference (p=0.28).). When in vivo sarcomere lengths were measured and fiber and bundle stiffness compared at these lengths, both fibers and bundles of patients with CP were predicted to be much stiffer in vivo compared to typically developing (TD) individuals. Interestingly, differences in fiber and bundle stiffness were not explained by typical biochemical measures such as titin molecular weight (a giant protein thought to impact fiber stiffness) or collagen content (a proxy for extracellular matrix amount). We suggest that the passive mechanical properties of fibers and bundles are thus poorly understood.

Using a triggered endocrinology service consultation to improve the evaluation, management, and follow-up of osteoporosis in hip-fracture patients.

BACKGROUND: Nearly 2 million osteoporosis-related fractures occur yearly in the United States, with more than 400,000 requiring hospital admissions. Fewer than 30% receive proper evaluation and care for osteoporosis, representing a large opportunity to enhance secondary prevention of fractures. Methods to improve identification and triage of hospitalized fragility-fracture patients are desirable. METHODS: A multidisciplinary team was created, and definitions were established for an evidence-based best-practice protocol to assess, treat, and document an osteoporosis diagnosis and triage patients with hip-fragility fractures on the basis of the best-practice recommendations from The Joint Commission and the National Osteoporosis Foundation. The team initiated a preauthorized osteoporosis consultation from the endocrinology service for hip-fracture patients, "triggered" via a brief query in admission orders or by the orthopedic service nurse practitioner. Osteoporosis consultations used a consultation template reflecting the protocol. RESULTS: Data were analyzed for 71 baseline patients and 61 intervention patients. The groups possessed similar age, gender, race, and body mass index characteristics. The baseline (on-demand consultation) group suffered from poor performance, with only 3%-21% of patients receiving the desired evaluation, documentation, treatment, or outpatient follow-up. Intervention (triggered-consultation) patients improved markedly postintervention, With performance increasing by 52%-76% on all parameters except outpatient follow-up, which changed insignificantly (6%-15%). CONCLUSION: Although triggered consultation was effective, multimodal layered interventions may achieve even better results and address several identified barriers.

Bone transport combined with locking bridge plate fixation for the treatment of tibial segmental defects: a report of 2 cases.

Segmental tibial bone loss, specifically in the setting of high-energy trauma, presents a challenging problem to the treating orthopaedic surgeon. These injuries are often complicated by tissue loss, poor wound healing, and infection. Many techniques of reconstruction have been advocated from bone grafting to bone transport. Transport can accomplished using Ilizarov frames, monolateral external fixators, and intramedullary devices. Although transport over an intramedullary device offers the advantage of rigidity and controlled alignment, many authors consider prolonged external fixation and history of pin tract infection to be contraindications to this technique. To our knowledge, bone segment transport used in combination with locking plate fixation has not been described for the treatment of tibial bone defects. We describe two cases of bone transport using a combination of locked plate fixation and a monolateral external fixation frame for large tibial bone defects. This technique allows for easy correction of length and alignment, stable fixation, facilitates quicker, and easier frame removal and also allows for compression of transported segment at the time of docking.

Effect of tibial plateau fracture on lubrication function and composition of synovial fluid.

BACKGROUND: Intra-articular fractures may hasten posttraumatic arthritis in patients who are typically too active and too young for joint replacement. Current orthopaedic treatment principles, including recreating anatomic alignment and establishing articular congruity, have not eliminated posttraumatic arthritis. Additional biomechanical and biological factors may contribute to the development of arthritis. The objective of the present study was to evaluate human synovial fluid for friction-lowering function and the concentrations of putative lubricant molecules following tibial plateau fractures. METHODS: Synovial fluid specimens were obtained from the knees of eight patients (twenty-five to fifty-seven years old) with a tibial plateau fracture, with five specimens from the injured knee as plateau fracture synovial fluid and six specimens from the contralateral knee as control synovial fluid. Each specimen was centrifuged to obtain a fluid sample, separated from a cell pellet, for further analysis. For each fluid sample, the start-up (static) and steady-state (kinetic) friction coefficients in the boundary mode of lubrication were determined from a cartilage-on-cartilage biomechanical test of friction. Also, concentrations of the putative lubricants, hyaluronan and proteoglycan-4, as well as total protein, were determined for fluid samples. RESULTS: The group of experimental samples were obtained at a mean (and standard deviation) of 11 ± 9 days after injury from patients with a mean age of 45 ± 13 years. Start-up and kinetic friction coefficients demonstrated similar trends and dependencies. The kinetic friction coefficients for human plateau fracture synovial fluid were approximately 100% higher than those for control human synovial fluid. Hyaluronan concentrations were ninefold lower for plateau fracture synovial fluid compared with the control synovial fluid, whereas proteoglycan-4 concentrations were more than twofold higher in plateau fracture synovial fluid compared with the control synovial fluid. Univariate and multivariate regression analysis indicated that kinetic friction coefficient increased as hyaluronan concentration decreased. CONCLUSIONS: Knees afflicted with a tibial plateau fracture have synovial fluid with decreased lubrication properties in association with a decreased concentration of hyaluronan.

Injuries sustained in noncombat motor vehicle accidents during Operation Iraqi Freedom.

OBJECTIVE: To examine injuries sustained in noncombat motor vehicle accidents (MVAs) during Operation Iraqi Freedom by injury type, site, and severity. METHODS: Three hundred and forty-eight military personnel injured in noncombat MVAs from March 2004-June 2007 were identified from clinical records completed near the point of injury. RESULTS: On average, personnel suffered two injuries per accident. The most frequent MVA mechanism was non-collision due to loss of control (30%). Overall, 16% were injured in a collision accident and 19% in a rollover accident. Rollovers were associated with more severe injuries. A greater proportion of drivers sustained head/neck/face injuries, whereas gunners and pedestrians had higher percents of extremity injuries. CONCLUSIONS: This analysis provides a thorough overview of injuries incurred in nonbattle MVAs in the combat environment. Future research should combine injury data with accident reports to elucidate areas for improvements in vehicle safety.

Long-term pain, stiffness, and functional disability after total knee arthroplasty with and without an extended ambulatory continuous femoral nerve block: a prospective, 1-year follow-up of a multicenter, randomized, triple-masked, placebo-controlled trial.

BACKGROUND: Previously, we have demonstrated that extending a continuous femoral nerve block (cFNB) from overnight to 4 days after total knee arthroplasty (TKA) provides clear benefits during the infusion, but not subsequent to catheter removal. However, there were major limitations in generalizing the results of that investigation, and we subsequently performed a very similar study using a multicenter format, with many health care providers, in patients on general orthopedic wards, thus greatly improving inference of the results to the general population. Not surprisingly, the perioperative/short-term outcomes differed greatly from the first, more limited study. We now present a prospective follow-up study of the previously published, multicenter, randomized controlled clinical trial to investigate the possibility that an extended ambulatory cFNB decreases long-term pain, stiffness, and functional disability after TKA, which greatly improves inference of the results to the general population. METHODS: Subjects undergoing TKA received a cFNB with ropivacaine 0.2% from surgery until the following morning, at which time patients were randomized to continue either perineural ropivacaine (n=28) or normal saline (n=26). Patients were discharged with their catheter and a portable infusion pump, and catheters were removed on postoperative day 4. Health-related quality of life was measured using the Western Ontario and McMaster Universities Osteoarthritis Index preoperatively and then at 7 days, as well as 1, 2, 3, 6, and 12 months after surgery. This index evaluates pain, stiffness, and physical functional disability. For inclusion in the analysis, we required a minimum of 4 of the 6 time points, including day 7 and at least 2 of months 3, 6, and 12. RESULTS: The 2 treatment groups had similar Western Ontario and McMaster Universities Osteoarthritis scores for the mean area-under-the-curve calculations (point estimate for the difference in mean area under the curve for the 2 groups [overnight infusion group - extended infusion group]=3.8; 95% confidence interval, -3.8 to +11.3; P=0.32) and at all individual time points (P>0.05). CONCLUSIONS: This investigation found no evidence that extending an overnight cFNB to 4 days improves (or worsens) subsequent pain, stiffness, or physical function after TKA in patients of multiple centers convalescing on general orthopedic wards.

Comparative efficacy of ultrasound-guided and stimulating popliteal-sciatic perineural catheters for postoperative analgesia.

PURPOSE: Perineural catheter insertion using ultrasound guidance alone is a relatively new approach. Previous studies have shown that ultrasound-guided catheters take less time to place with high placement success rates, but the analgesic efficacy compared with the established stimulating catheter technique remains unknown. We tested the hypothesis that popliteal-sciatic perineural catheter insertion relying exclusively on ultrasound guidance results in superior postoperative analgesia compared with stimulating catheters. METHODS: Preoperatively, subjects receiving a popliteal-sciatic perineural catheter for foot or ankle surgery were assigned randomly to either ultrasound guidance (bolus via needle with non-stimulating catheter insertion) or electrical stimulation (bolus via catheter). We used 1.5% mepivacaine 40 mL for the primary surgical nerve block and 0.2% ropivacaine (basal 8 mL·hr(-1); bolus 4 mL; 30 min lockout) was infused postoperatively. The primary outcome was average surgical pain on postoperative day one. RESULTS: Forty of the 80 subjects enrolled were randomized to each treatment group. One of 40 subjects (2.5%) in the ultrasound group failed catheter placement per protocol vs nine of 40 (22.5%) in the stimulating catheter group (P = 0.014). The difference in procedural duration (mean [95% confidence interval (CI)]) was -6.48 (-9.90 - -3.05) min, with ultrasound requiring 7.0 (4.0-14.1) min vs stimulation requiring 11.0 (5.0-30.0) min (P < 0.001). The average pain scores of subjects who provided data on postoperative day one were somewhat higher for the 33 ultrasound subjects than for the 26 stimulation subjects (5.0 [1.0-7.8] vs 3.0 [0.0-6.5], respectively; P = 0.032), a difference (mean [95%CI]) of 1.37 (0.03-2.71). CONCLUSION: For popliteal-sciatic perineural catheters, ultrasound guidance takes less time and results in fewer placement failures compared with stimulating catheters. However, analgesia may be mildly improved with successfully placed stimulating catheters. Clinical trial registration number NCT00876681.

A multicenter, randomized, triple-masked, placebo-controlled trial of the effect of ambulatory continuous femoral nerve blocks on discharge-readiness following total knee arthroplasty in patients on general orthopaedic wards.

A continuous femoral nerve block (cFNB) involves the percutaneous insertion of a catheter adjacent to the femoral nerve, followed by a local anesthetic infusion, improving analgesia following total knee arthroplasty (TKA). Portable infusion pumps allow infusion continuation following hospital discharge, raising the possibility of decreasing hospitalization duration. We therefore used a multicenter, randomized, triple-masked, placebo-controlled study design to test the primary hypothesis that a 4-day ambulatory cFNB decreases the time until each of three predefined readiness-for-discharge criteria (adequate analgesia, independence from intravenous opioids, and ambulation 30m) are met following TKA compared with an overnight inpatient-only cFNB. Preoperatively, all patients received a cFNB with perineural ropivacaine 0.2% from surgery until the following morning, at which time they were randomized to either continue perineural ropivacaine (n=39) or switch to normal saline (n=38). Patients were discharged with their cFNB and portable infusion pump as early as postoperative day 3. Patients who were given 4 days of perineural ropivacaine attained all three criteria in a median (25th-75th percentiles) of 47 (29-69)h, compared with 62 (45-79)h for those of the control group (Estimated ratio=0.80, 95% confidence interval: 0.66-1.00; p=0.028). Compared with controls, patients randomized to ropivacaine met the discharge criterion for analgesia in 20 (0-38) versus 38 (15-64)h (p=0.009), and intravenous opioid independence in 21 (0-37) versus 33 (11-50)h (p=0.061). We conclude that a 4-day ambulatory cFNB decreases the time to reach three important discharge criteria by an estimated 20% following TKA compared with an overnight cFNB, primarily by improving analgesia.

Plantar flexion influences radiographic measurements of the ankle mortise.

BACKGROUND: The treatment of ankle fractures often depends on the integrity of the deltoid ligament. Diagnosis of a deltoid ligament tear depends on the measurement of the medial clear space. We sought to evaluate the impact of ankle plantar flexion on the medial clear space. METHODS: Mortise radiographs were made for twenty-five healthy volunteers, with the ankle in four positions of plantar flexion (0 degrees, 15 degrees, 30 degrees, and 45 degrees). Four observers measured the medial clear space and the superior clear space on each radiograph. The mean medial clear space at 0 degrees was defined as the control, and the deviation of the medial clear space from the control value was calculated at 15 degrees, 30 degrees, and 45 degrees of plantar flexion. The ratio of the medial clear space to the superior clear space was determined on all radiographs, and ratios that were false-positive for a deltoid ligament injury were identified. RESULTS: Fourteen male and eleven female volunteers were evaluated. The average increase in the medial clear space when ankle plantar flexion was increased from 0 degrees to 45 degrees was 0.38 mm (95% confidence interval, 0.18 to 0.58 mm). This increase was significant (p = 0.005). The average increase in the medial clear space was 0.04 mm when ankle plantar flexion was increased from 0 degrees to 15 degrees and 0.22 mm when it was increased from 0 degrees to 30 degrees. Neither of these changes was significant (p = 0.99 and 0.20). The prevalence of false-positive findings of deltoid injury based on the ratio of the medial clear space to the superior clear space increased as ankle plantar flexion increased, but this increase did not reach significance in our study group (p = 0.18). CONCLUSIONS: Plantar flexion of the ankle produces changes in radiographic measurements of the medial clear space. The potential for false-positive findings of deltoid disruption increases with increasing ankle plantar flexion.

Continuous peripheral nerve blocks: is local anesthetic dose the only factor, or do concentration and volume influence infusion effects as well?

BACKGROUND: The main determinant of continuous peripheral nerve block effects--local anesthetic concentration and volume or simply total drug dose--remains unknown. METHODS: We compared two different concentrations and basal rates of ropivacaine--but at equivalent total doses--for continuous posterior lumbar plexus blocks after hip arthroplasty. Preoperatively, a psoas compartment perineural catheter was inserted. Postoperatively, patients were randomly assigned to receive perineural ropivacaine of either 0.1% (basal 12 ml/h, bolus 4 ml) or 0.4% (basal 3 ml/h, bolus 1 ml) for at least 48 h. Therefore, both groups received 12 mg of ropivacaine each hour with a possible addition of 4 mg every 30 min via a patient-controlled bolus dose. The primary endpoint was the difference in maximum voluntary isometric contraction (MVIC) of the ipsilateral quadriceps the morning after surgery, compared with the preoperative MVIC, expressed as a percentage of the preoperative MVIC. Secondary endpoints included hip adductor and hip flexor MVIC, sensory levels in the femoral nerve distribution, hip range-of-motion, ambulatory ability, pain scores, and ropivacaine consumption. RESULTS: Quadriceps MVIC for patients receiving 0.1% ropivacaine (n = 26) declined by a mean (SE) of 64.1% (6.4) versus 68.0% (5.4) for patients receiving 0.4% ropivacaine (n = 24) between the preoperative period and the day after surgery (95% CI for group difference: -8.0-14.4%; P = 0.70). Similarly, the groups were found to be equivalent with respect to secondary endpoints. CONCLUSIONS: For continuous posterior lumbar plexus blocks, local anesthetic concentration and volume do not influence nerve block characteristics, suggesting that local anesthetic dose (mass) is the primary determinant of perineural infusion effects.