Incidence and Risk Factors for Acid-fast Bacillus/Fungal Culture Positivity in Primary, Conversion, and Revision Hip and Knee Arthroplasty.

INTRODUCTION: Previous literature has reported minimal incidences of positive fungal/AFB cultures, questioning the routine use of these tests. With growing concern for excessive use, predictive factors for patients at higher risk for intraoperative AFB/fungal infections would help surgeons limit unnecessary testing. This study evaluates the positivity rate and predictive factors of positive fungal and/or acid-fast bacillus (AFB) cultures after primary, conversion, or revision hip and knee arthroplasty. METHOD: Two hundred thirty-eight knee and hip procedures were done between January 2007 and 2022 where intraoperative AFB/fungal cultures were obtained. Procedures included primary total knee arthroplasty, primary total hip arthroplasty, conversion, first of two-stage, second of two-stage, irrigation and débridement polyexchange, and aseptic revision. Positivity rates of intraoperative AFB/fungal cultures were calculated as binomial exact proportions with 95% confidence intervals and are displayed as percentages. Univariable generalized linear mixed models estimated the unadjusted effects of demographics, individual comorbid conditions, and procedural characteristics on the logit of positive AFB/fungal cultures. RESULTS: Two hundred thirty-eight knee and hip procedures recorded an overall positivity rate of 5.8% for intraoperative AFB/fungal cultures. Aseptic revisions showed the lowest rates of positivity at 3.6%, while conversions showed the highest rates of positivity at 14.3%. The positivity rates are highest among patients who are male (9.0%), of Hispanic origin (12.0%), with body mass index <30 (6.4%), and a Charlson Comorbidity Index <5 (6.1%). History of a prior infection in the same surgical joint showed statistically significant influence of odds of culture positivity with an odds ratio of 3.47 ( P -value: 0.039). Other demographic factors that we investigated including age, sex, race, ethnicity, body mass index, and Charlson Comorbidity Index did not show any notable influence on AFB/fungal positivity rates. CONCLUSION: These results suggest utility in obtaining routine intraoperative AFB/fungal cultures, given the relatively high positivity and poor predictive factors.

Accuracy of intraoperative approximation of pelvic tilt using preoperative standing radiographs.

Background: Anterior approach surgeons who utilize intraoperative fluoroscopy often try to match a preoperative radiograph as a reference for intraoperative cup position. Every degree of inaccuracy in tilt leads to a roughly 0.7° change in anteversion. This study aimed to determine how closely pelvic tilt (PT) is approximated intraoperatively when compared to preoperative anteroposterior (AP) radiographs. Methods: This was a retrospective review of 193 primary THA's done by 2 surgeons at an academic tertiary referral center between September 2021-January 2023. There were 24 patients excluded for distorted anatomy, post-traumatic arthritis, insufficient x-rays, or a sacroiliac joint that could not be visualized on film. Data collected included age and BMI. PT was calculated using the formula, Tilt = -(ln((B/A) x (1/0.483)))/0.051. Value A is the distance from the base of the SI joint to the superior margin of the obturator foramen; value B is the height of the obturator foramen. Results: Mean preoperative PT was 0.2° versus intraoperative PT was 3.4° (p < 0.001). Mean absolute difference was 6.5°. 48% of patients (n = 81) had an absolute difference less than 5°, 31% (n = 52) between 5° and 10°, 14% (n = 24) between 10° and 15°, and 7% (n = 12) greater than 15°. There was no correlation between BMI or age and PT discrepancy. Conclusion: Of the patients, 21% had a discrepancy of 10° or greater between their preoperative radiographs and intraoperative fluoroscopic images. Surgeons should be aware of potential errors in cup positioning and be particularly diligent in high-risk cases.

Treatment of tegmen dehiscence using a middle fossa approach and autologous temporalis fascia graft: Outcomes from a single center.

INTRODUCTION: Although bony defects of the tegmen surface are relatively common, the majority of dehiscences are asymptomatic. For those who experience symptoms, there is a wide spectrum of relatively benign manifestations such as hearing loss and otorrhea to potentially more serious but rare sequelae such as epilepsy and meningitis. Surgical management of tegmen dehiscences (TDs) can help prevent these symptoms. In this manuscript, we present one of the largest reported single team experiences of using a temporal craniotomy with middle cranial fossa approach and temporalis fascia graft in the treatment of tegmen defects. METHODS: We retrospectively reviewed every case of a TD surgically repaired by the same neurosurgeon/otolaryngologist team at Loyola University Medical Center from May 2015 to January 2022. In our chart review, we identified 44 patients with 48 cases of tegmen defect repair. We analyzed patient characteristics, operative details, and postoperative outcomes. RESULTS: 44 patients met inclusion criteria for the presence of TD (mean age 55 years, 55% male, and average body mass index 35.6). 89% of these patients had no clear etiology for the dehiscence. Commonly reported symptoms were hearing loss (89%) and CSF otorrhea (82%). The least reported presenting signs and symptoms were seizures (5%) and meningitis (2%). Most defects were repaired with both temporalis fascial and calvarial bone grafts (63%), while a minority were treated with temporalis fascia only (33%), temporalis fascia with muscle (2%), or fascia lata (2%). Every patient in our sample experienced resolution of CSF otorrhea after tegmen repair and 81% of the sample reported subjective hearing improvements after surgery. 6% of our sample had post-operative infections and 8% of patients underwent repeat unilateral surgery for a surgical complication. CONCLUSION: Craniotomy for middle fossa approach using autologous temporalis fascial grafts is a safe and effective method for the treatment of TD. These procedures should be performed by experienced and multidisciplinary teams.