Nicotine Dependence and Rates of Postoperative Complications in Achilles Tendon Repair.

BACKGROUND: Nicotine is a modifiable risk factor that is well demonstrated to cause deleterious effects on tendon healing and overall health. Individuals that have a dependence on nicotine may be at an elevated risk for numerous postoperative complications when compared to nondependent patients. The purpose of this study is to evaluate the complications postoperatively between nicotine- and non-nicotine-dependent Achilles tendon repairs. METHODS: The global health network database, TriNetX, was used to access and analyze deidentified patient information. Two cohorts were identified for the purposes of this study. Cohort A was defined as patients who had an Achilles tendon repair (Current Procedural Terminology [CPT]: 27650 or CPT: 27654) and had a dependence to nicotine (International Classification of Diseases, Tenth Revision, code: F17). Cohort B was defined as patients who had an Achilles tendon repair but did not have a dependence to nicotine. Data were gathered from health care organizations from August 21, 2000, to August 21, 2023. All postoperative complications were analyzed between 1 and 90 days after the Achilles tendon repair. RESULTS: A total of 2117 nicotine-dependent patients were matched with 18 102 non-nicotine-dependent patients. After propensity matching for age at event, ethnicity, race, sex, and type 2 diabetes mellitus, nicotine-dependent patients who underwent Achilles tendon repair experienced higher associated risk for numerous postoperative complications. When compared to nondependent patients, nicotine-dependent patients had increased risk for wound disruption (risk ratio [RR] 1.55, 95% CI 1.11-2.16) and infection following a procedure (RR 1.64, 95% CI 1.09-2.47) within 90 days post Achilles tendon repair. CONCLUSION: In this database study using propensity matching, nicotine-dependent patients who underwent Achilles tendon repair were correlated with an increased associated risk for wound disruption and infection after a procedure than their non-nicotine-dependent counterpart. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Radiographic Anatomy of the Lateral Ankle Ligament Complex: A Cadaveric Study.

BACKGROUND: When lateral ankle sprains progress into chronic lateral ankle instability (CLAI), restoring precise anatomic relationships of the lateral ankle ligament complex (LALC) surgically is complex. This study quantifies the radiographic relationships between the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and prominent osseous landmarks visible under fluoroscopy to assist in perioperative practices for minimally invasive surgery for CLAI. METHODS: Ten fresh frozen ankle specimens were dissected to expose the LALC and prepared by threading a radiopaque filament through the ligamentous footprints of the ATFL and CFL. Fluoroscopic images were digitally analyzed to define dimensional characteristics of the ATFL and CFL. Directional measurements of the ligamentous footprints relative to the lateral process of the talus and the apex of the posterior facet of the calcaneus were calculated. RESULTS: Dimensional measurements of the ATFL were a mean length of 9.3 mm, fibular footprint of 9.4 mm, and talar footprint of 9.1 mm. Dimensional measurements of the CFL were a mean length of 19.4 mm, fibular footprint of 8.2 mm, and calcaneal footprint of 7.3 mm. From the radiographic apparent tip of the lateral process of the talus, the fibular attachment of the ATFL was found 13.3 mm superior and 4.4 mm posterior, whereas the talar attachment was found 11.5 mm superior and 4.8 mm anterior. From the radiographic apparent posterior apex of the posterior facet of the calcaneus, the fibular attachment of the CFL was found 0.2 mm inferior and 6.8 mm anterior, whereas the calcaneal attachment was found 14.3 mm inferior and 5.9 mm posterior. CONCLUSION: The ATFL and CFL were radiographically analyzed using radiopaque filaments to outline the ligamentous footprints in their native locations. These ligaments were also localized with reference to 2 prominent osseous landmarks. These findings may assist in perioperative practices for keyhole incision placement and arthroscopic guidance. Perfect lateral ankle joint imaging with talar domes superimposed is required to be able to do this. CLINICAL RELEVANCE: Radiographic evaluation of the ATFL and CFL with reference to prominent osseous landmarks identified under fluoroscopy may assist in perioperative practices for minimally invasive surgery to address CLAI for keyhole incision placement and arthroscopic guidance.

Safe driving recommendations following lower extremity orthopedic surgery: a systematic review.

PURPOSE: We analyzed the published literature on return-to-driving (RTD) recommendations following lower extremity orthopedic surgery, including knee and hip arthroplasty and ankle and foot surgery. METHODS: We conducted a PubMed MEDLINE database search for the relevant literature spanning from 1988 to 2022. Data were extracted from the selected articles independently by six investigators, and the mean, standard deviation, and range of RTD recommendations for each surgical region and procedure were calculated. RESULTS: The 34 studies included in our review evaluated brake response time, reaction time, movement time, braking force, and other parameters. Average RTD recommendations in weeks were: hip surgeries, 4.1 (± 2.7); foot surgeries, 6.67 (± 0.94); Achilles surgeries, 6.67 (± 0.25); ankle surgeries, 4 (± 2); knee surgeries, 5.42 (± 0.77); and multiple lower extremity surgeries, 3.85 (± 0.15). CONCLUSION: Our findings can assist physicians in providing informed recommendations to patients, promoting safe driving practices, and optimizing postoperative recovery. LEVEL OF EVIDENCE: Therapeutic, Level III: Retrospective comparative study.

Return to Play Rates Following Operative Ankle Fractures Differ Between High- and Low-Performing National Football League Athletes.

This study investigated predictive factors for return to play among National Football League athletes after operative treatment of ankle fractures and the impacts of these injuries on career longevity and player performance. Athletes who underwent surgery to repair ankle fractures from the 2013 to 2017 seasons were identified from injury reserve lists and press releases. Demographics and season metrics were collected before and after the injury. Statistical analysis assessed for differences in recorded variables between injured and uninjured players. Thirty-one players met study inclusion criteria. Twenty-two (71%) athletes successfully returned to play. Players who did not return showed no significant differences (P>.05) in position, age, body mass index, number of games or seasons played preinjury, or snaps per game the season prior to injury and had a significantly lower (42.6%, P=.013) preinjury season approximate value (SAV) compared with returning players. Returning athletes showed no significant differences (P>.05) in SAV or snaps per game compared with their preinjury season or with uninjured controls. A high preinjury SAV is associated with successful return to play. No difference in game time or performance metrics was detectable between returning players and uninjured controls, or between preinjury and postinjury seasons. [Orthopedics. 2024;47(1):22-27.].

Current concepts in ankle fractures.

Ankle fractures are among the most common orthopaedic injuries. Operative management is performed in unstable ankle fracture patterns to restore the stability and native kinematics of the ankle mortise and minimize the risk of post-traumatic degenerative changes. In this study, we review current concepts in ankle fracture management, including posterior malleolus fixation, syndesmosis fixation, deltoid ligament repair, fibular nailing, and early weightbearing, from both a biomechanical and clinical perspective.

Republication of "Peroneus Brevis Tenodesis: Side-to-Side or Weave?"

Background: Inversion ankle injuries are extremely common, sometimes causing injury to the peroneus brevis tendon. If more than 50% of the tendon is injured, it oftentimes requires tenodesis to the adjacent peroneus longus tendon. Both Pulvertaft (PT) and side-to-side (SS) techniques have been used for joining the 2 tendons. The purpose of this study was to compare the strength and stiffness of these 2 techniques. Methods: Five matched pairs of cadaver ankle specimens were randomized to receive either an SS or PT tenodesis of the peroneus brevis to longus tendons. Following the tenodesis, the specimens were tested for failure load, displacement, energy absorbed at failure, and peak load. Stiffness was also calculated. Paired t tests were performed to detect differences between the 2 conditions. Results: There were no statistically significant differences between the SS and PT tenodesis for any of the metrics measured. For stiffness, the techniques were very similar (SS = 10.14 [4.35], PT = 12.85 [1.72]). Conclusion: There is no difference in failure load, displacement, energy absorbed at failure, peak load or stiffness between the PT and SS techniques for peroneal tenodesis. Level of Evidence: Level V, cadaver study.

Patient Perceptions of Surgeon Reimbursement in Total Ankle Arthroplasty.

INTRODUCTION: The incidence of total ankle arthroplasty (TAA) for ankle osteoarthritis has increased in the Medicare population by approximately 16.37% each year. This study examines the patient perception of orthopedic surgeon reimbursement for TAA by Medicare. METHODS: A total of 78 patients were surveyed anonymously at 2 foot and ankle clinics within an academic health care setting. The surveys were given anonymously before the patients were seen by an orthopedic surgeon. Surveys were returned to office staff who placed them in a collection box to ensure confidentiality. RESULTS: The average estimate of how much orthopedic surgeons should be reimbursed for TAA was $19 506 and the average estimate of how much orthopedic surgeons were actually reimbursed was $20 772. Fifty patients believed that orthopedic surgeons were under reimbursed, 9 believed that they were reimbursed appropriately, and 19 were unsure. Demographic variables such as age, sex, education level, income, and insurance status had no significant effect on the results. CONCLUSIONS: Most patients believed orthopedic surgeons are under reimbursed for TAA and that there is a lack of health care transparency regarding orthopedic reimbursement for TAA by Medicare.Levels of Evidence: Level V: Expert opinion.

Five-Factor Modified Frailty Index as a Predictor of Complications Following Total Ankle Arthroplasty.

INTRODUCTION: Ankle arthritis adversely affects patients' function and quality of life. Treatment options for end-stage ankle arthritis include total ankle arthroplasty (TAA). A 5-item modified frailty index (mFI-5) has predicted adverse outcomes following multiple orthopaedic procedures; this study evaluated its suitability as a risk-stratification tool in patients undergoing TAA. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was retrospectively reviewed for patients undergoing TAA between 2011 and 2017. Bivariate and multivariate statistical analyses were performed to investigate frailty as a possible predictor of postoperative complications. RESULTS: In total, 1035 patients were identified. When comparing patients with an mFI-5 score of 0 versus ≥2, overall complication rates significantly increased from 5.24% to 19.38%, 30-day readmission rate increased from 0.24% to 3.1%, adverse discharge rate increased from 3.81% to 15.5%, and wound complications increased from 0.24% to 1.55%. After multivariate analysis, mFI-5 score remained significantly associated with patients' risk of developing any complication (P = .03) and 30-day readmission rate (P = .005). CONCLUSIONS: Frailty is associated with adverse outcomes following TAA. The mFI-5 can help identify patients who are at an elevated risk of sustaining a complication, allowing for improved decision-making and perioperative care when considering TAA. LEVELS OF EVIDENCE: III, Prognostic.

The Effects of COVID-19 on Orthopaedic Surgery Training Programs in the United States.

INTRODUCTION: This study investigates the effects of the COVID-19 pandemic on medical education, research opportunities, and mental health in orthopaedic surgical training programs. METHODS: A survey was sent to the 177 Electronic Residency Application Service-participating orthopaedic surgery training programs. The survey contained 26 questions covering demographics, examinations, research, academic activities, work settings, mental health, and educational communication. Participants were asked to assess their difficulty in performing activities relative to COVID-19. RESULTS: One hundred twenty-two responses were used for data analysis. Difficulties were experienced in collaborating with others (49%), learning through online web platforms (49%), maintaining the attention span of others through online web platforms (75%), and in gaining knowledge as a presenter or participating through online web platforms (56%). Eighty percent reported that managing time to study was the same or easier. There was no reported change in difficulty for performing activities in the clinic, emergency department, or operating room. Most respondents reported greater difficulty in socializing with others (74%), participating in social activities with coresidents (82%), and seeing their family (66%). Coronavirus disease 2019 has had a significant effect on the socialization of orthopaedic surgery trainees. DISCUSSION: Clinical exposure and engagement were marginally affected for most respondents, whereas academic and research activities were more greatly affected by the transition from in-person to online web platforms. These conclusions merit investigation of support systems for trainees and evaluating best practices moving forward.

Squamous Cell Carcinoma of the Foot Occurring in a Wart.

Verrucous carcinoma is a rare form squamous cell carcinoma which appears similar to a wart. When it occurs in the feet, it can be easily misdiagnosed. It rarely metastasizes or recurs posttreatment. We report a case of a septuagenarian with recurrence of verrucous carcinoma diagnosed within 6 months at the site of previous treatment. Unique features in our patient's clinical presentation include his advanced age, being nondiabetic, and the rapid recurrence of carcinoma.Level of Evidence: Level IV: Case report.

Quality and Readability of Information Regarding Total Ankle Arthroplasty Available to Patients on the Internet.

This study sought to evaluate the reliability, comprehensiveness, and readability of ankle arthroplasty information available on the Internet. We evaluated websites based on category, Journal of the American Medical Association (JAMA) criteria, Health on the Net (HON) code, DISCERN score, an author-created Ankle Replacement Index (ARI), and readability metrics. Based on the ARI, 80 (62.5%) websites provided poor information. The mean reading level was 8.96 ± 2.66, which is above the recommended sixth-grade reading level for patient information. Academic websites had the highest mean DISCERN, ARI, and JAMA scores, and a midrange reading level. The government category had high DISCERN and JAMA scores, a fair ARI score, and the lowest reading level. We found significant correlation between website class and DISCERN score, as well as HON code and DISCERN score. Our results suggest that academic and government websites provide more reliable, complete information than other categories and that websites with an HON code contain more reliable information than those without. We recommend that physicians create handouts to point patients to reliable resources and encourage them to critically evaluate information they read online. We also encourage physicians to take part in evaluating and updating information on their practice websites.Level of Clinical Evidence: N/A.

Assessing the Utility of Deltoid Ligament Repair in Ankle Fracture: A Systematic Review.

Ankle fractures are common injuries treated by orthopedists. Indications for operative repair of deltoid ligament (DL) injuries in ankle fracture patients are debated. The purpose of this review is to determine the indications for operative DL repair. Ovid MEDLINE, CINAHL, and Scopus were searched up to December 2019. Web of Science was searched up to August 2018. Search terms included "Deltoid" and "Ligament" or "Ligaments." Comparative studies assessing conservative vs operative DL repair were searched for. Articles meeting inclusion criteria were screened in two stages to determine eligibility. Out of 1,542 articles, nine were included in our qualitative synthesis. These nine studies included 449 patients, of which 233 were treated with open reduction internal fixation (ORIF) with or without trans-syndesmotic (TS) screw fixation, and 205 of which were treated with ORIF with DL repair. The remaining 21 patients were managed nonoperatively, had no evidence of DL injury, or were lost to follow-up. There is a lower rate of malreduction associated with DL repair compared to TS screw fixation. Moreover, DL repair may be useful in treating patients with Weber Type C fractures, concomitant DL-syndesmotic disruption, or residual valgus instability following ORIF in isolated lateral malleolar fractures.

Comparative Analysis of Secondary Outcomes in Treatment of Charcot Neuropathy: A Systematic Review.

BACKGROUND: Charcot neuroarthropathy (CN) is commonly associated with diabetic neuropathy and can predispose patients to amputations. Management remains a challenge, with no definitive treatment. This study examines major postoperative complications associated with open reduction with internal (intramedullary) nails, fixation, external fixation, or combined internal and external fixation for correction of the deformity. METHODS: We reviewed available literature using PubMed, OvidSP, Scopus, and Cochrane and searched bibliographies of the included studies to identify additional pertinent references. After review and agreement among 4 raters, a total of 15 studies were included in this analysis. RESULTS: Hardware removal rates were 0.133 for intramedullary nails, 0.007 for external fixators, and 0.050 for combined fixation. Rates of hardware complication were 0.182 for intramedullary nails and 0.007 for external fixators. Wound dehiscence occurred at rates of 0.059 for intramedullary nails and 0.216 for combined fixation. The rate of deep infections was 0.031 for intramedullary nails, 0.032 for external fixators, and 0.113 for combined fixation. The rate of irrigation and debridement was 0.007 for external fixators. CONCLUSION: Rates of hardware removal (13.3%) and complications (18.2%) were high with intramedullary nails. Dehiscence (21.6%) and deep infection (11.3%) were high in combined fixation. Other complications occurred relatively rarely. LEVEL OF EVIDENCE: Level III.

Management of Insertional Achilles Tendinopathy.

Insertional Achilles tendinopathy is a common condition that can lead to chronic, debilitating heel pain in athletes and nonathletes alike. Conservative treatment options include activity and shoe wear modification, physical therapy, injections, and extracorporeal shock wave therapy. When nonsurgical treatment fails, surgical treatment is recommended. Although there are options aimed at preserving the tendon and débriding the retrocalcaneal bursa and excess bone formation, others are aimed at detaching the Achilles tendon to perform a thorough débridement and subsequent reattachment. Additional or alternate procedures may include a calcaneal closing wedge osteotomy, gastrocnemius lengthening, and flexor hallucis longus tendon transfer. Recent advances in suture anchor techniques further add to the complexity of available options. This review discusses the relevant anatomy, biomechanics, and pathophysiology as well as the recent available evidence for nonsurgical and surgical management of this condition to guide surgeons in selecting the most appropriate treatment for their patients.

Primary Arthrodesis Versus Open Reduction and Internal Fixation Outcomes for Lisfranc Injuries: An Analysis of Conflicting Meta-analyses Results.

INTRODUCTION: The superiority of primary arthrodesis (PA) versus open reduction and internal fixation (ORIF) in Lisfranc injuries has been debated. Meta-analyses comparing these surgical options have reached contradicting conclusions. The goal of this article is to determine why different conclusions were reached and provide clarity on the comparable outcomes of PA and ORIF in Lisfranc injuries. METHODS: A systematic literature review was conducted by searching for "meta-analysis" AND "Lisfranc" with keywords such as "ORIF" OR "open reduction" OR "arthrodesis" OR "fusion." Five meta-analysis articles discussing PA and ORIF in Lisfranc injuries were identified. Study outcomes were extracted from each article, and contradicting conclusions were identified for analysis. RESULTS: PA had lower rates of hardware removal. There was no difference between PA and ORIF when considering revision surgery, anatomic reduction, postoperative infection, total complications, and patient satisfaction. However, contradicting conclusions were reached for return to duty, the American Orthopaedic Foot and Ankle Society (AOFAS) score, and visual analogue scale (VAS) score. Conclusions. There was no difference in PA and ORIF for return to work and VAS score. Repeat meta-analysis with truly equivocal outcomes would be necessary to reach a valid conclusion for return to full activity and AOFAS midfoot scores. LEVELS OF EVIDENCE: Level II: Therapeutic studies.

Techniques and complications of popliteal nerve blocks.

BACKGROUND: Use of popliteal nerve blocks (PNBs) as an alternative or adjunctive therapy to traditional methods of pain control (e.g., systemic or spinal anesthesia and opioids) is increasingly popular in foot and ankle surgery. METHODS: We reviewed online databases for literature on PNBs in foot and ankle surgery to analyze the various techniques and positioning used, the influence of drugs on their efficacy, and possible complications associated with their use. Thirty articles were identified with a predefined search criteria, followed by a review process for relevance. RESULTS: Patient demographics, procedure specifics, and block techniques, such as anesthetic used, can impact the duration and success of a PNB. Administration with ultrasound guidance proved superior to nerve stimulation, and preoperative administration was superior to postoperative administration. CONCLUSIONS: PNBs are an effective method to control postoperative pain with minimal complications, leading to decreased analgesic use, earlier discharge, and higher patient satisfaction. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Biomechanical Comparison of a Novel Method of Tricortical Kirschner Wire Fixation of Distal Chevron Osteotomies of the First Metatarsal Versus Traditional Kirschner Wire and Versus Screw Fixation.

INTRODUCTION: Traditional Kirschner wire (K-wire) stabilization of first metatarsal distal chevron osteotomy involves 1 cortex of fixation; however, unicortical fixation is associated with a high complication rate, including pin migration. A method of K-wire fixation utilizing 3 cortices may be biomechanically superior and potentially equivalent to single-screw fixation. METHODS: Cadaveric specimens fixed with tricortical K-wires were tested in both the physiologic and cantilever conditions against specimens fixed with unicortical K-wires (N = 8) and single screws (N = 9) utilizing matched-pair comparison groups. Differences in physiologic and cantilever fixed/intact stiffness ratio and cantilever failure load were determined. RESULTS: The tricortical fixation specimens had a significantly higher stiffness ratio in cantilever loading than the unicortical fixation specimens (60.50% tricortical, 34.17% unicortical, P = .02) but not in physiologic load (15.34% tricortical, 25.75% unicortical, P = .23). In cantilever failure loading, the tricortical fixation specimens had a significantly higher load to failure than the unicortical fixation specimens (132.81 N tricortical, 58.58 N unicortical, P < .01). Stiffness ratio under physiologic load, cantilever load, and ultimate load to failure were not significantly different between tricortical K-wire and screw-fixation groups. CONCLUSION: Tricortical K-wire fixation for distal chevron osteotomies is biomechanically superior to traditional unicortical K-wire fixation, and equivalent to single-screw fixation. LEVELS OF EVIDENCE: Level V: Cadaver study.

Distribution of High-Volume Ankle Replacement Surgeons in United States Metropolitan Areas.

BACKGROUND: Ankle osteoarthritis is increasing, thus creating greater demand for high-volume total ankle arthroplasty (TAA) surgeons. The Medicare Provider Utilization and Payment Data Public Use File (MPUPD-PUF) provides volume and reimbursement data for procedures performed by physicians participating in Medicare. This study analyzes surgeon prevalence, surgeon distribution, and factors affecting surgeon prevalence in metropolitan areas. METHODS: The MPUPD-PUF was reviewed from 2012 to 2015, and data were extracted for physicians performing ≥11 TAA procedures. Physicians in metropolitan areas (population >1 million) were grouped together, and reimbursement, number of high-volume surgeons, and procedures were calculated. Presence of an American Orthopaedic Foot and Ankle Society (AOFAS) fellowship program was analyzed for associations with high-volume TAA surgeons. RESULTS: Fifty-three surgeons performed ≥11 TAA procedures (1,960 total) covered by Medicare. Of these surgeons, 66% practice in metropolitan areas with a population >1 million. Fifty-one percent of US major metropolitan areas contained no surgeon who submitted >10 traditional Medicare claims for TAA. Areas with an AOFAS fellowship had nominally more TAA claims submitted. CONCLUSIONS: The distribution of high-volume TAA surgeons among major metropolitan areas in the United States is highly unequal. Analyzing the data with this method aids in targeting TAA surgeons to currently underserved areas. LEVELS OF EVIDENCE: Level IV: Retrospective-comparative study.

Differences in cancer amputee survival based on marital status: an analysis of the Surveillance, Epidemiology, and End Results (SEER) database.

PURPOSE: Limb amputation is a life-altering procedure used to treat certain cancer patients. The influence of psychosocial factors (such as marital status) on outcomes is poorly understood, hindering the development of targeted resources for the specific needs of these patients. This study was conducted to characterize the influence of marital status on survival after cancer-related amputation. DESIGN/RESEARCH APPROACH: Retrospective cohort study. SAMPLE: 1,516 patients with cancer-related amputation were studied from the Surveillance, Epidemiology and End Results database. METHODS: Patients were grouped by marital status as single, married or divorced/separated/widowed and survival was compared using multivariate cox regression adjusted for demographic, tumor and treatment factors. FINDINGS: Adjusted analysis showed that single (HR, 1.213; p = .044) patients had a significantly higher overall mortality-risk, while divorced/separated/widowed patients had both a significantly higher overall (HR, 1.397; p < .001) and cause-specific mortality-risk (HR, 1.381; p = .003) compared to married patients. CONCLUSION: We posit that the increased psychosocial support available to married cancer patients may play a key role in improving survival. IMPLICATIONS FOR PSYCHOSOCIAL PROVIDERS: These findings provide new insight about the psychosocial needs of cancer amputees and the prognostic implications for those lacking social support of a spouse.

Inappropriate antibiotic administration in the setting of Charcot arthropathy: A case series and literature review.

AIMS: Differentiating Charcot neuropathic osteoarthropathy (CN) from infection is challenging. The diagnosis of CN is often missed or delayed, resulting in inappropriate and delayed treatment. We hypothesized that the misdiagnosis of CN results in inappropriate antibiotic prescriptions and explore the sequelae of unnecessary antibiotic use. METHODS: A retrospective review of patient electronic medical records from January 2010 to December 2017 was conducted for those diagnosed with CN after being referred to an orthopaedic foot and ankle specialist. RESULTS: Our review showed 58 of 103 (56%) patients received antibiotics on the date, or within the next 7 days, of referral to foot and ankle orthopaedic specialist. The antibiotic of choice given on referral were as follows: Sulfamethoxazole/Trimethoprim 18 of 58 (31%), doxycycline 13 of 58 (22%), clindamycin 13 of 58 (22%), cephalexin 9 of 58 (16%), minocycline 5 of 58 (9%). CONCLUSION: Missed diagnoses for CN are common and result in complications stemming from inappropriate treatment, delays in appropriate therapy, and may accelerate antibiotic resistance. Misdiagnosis of CN contributes to the inappropriate use of prescription antibiotics.