Anthony T. Tokarski

Why Are Total Knee Arthroplasties Failing Today—Has Anything Changed After 10 Years?

The purpose of this study was to determine the frequency and cause of failure after total knee arthroplasty and compare the results with those reported by our similar investigation conducted 10 years ago. A total of 781 revision TKAs performed at our institution over the past 10 years were identified. The most common failure mechanisms were: loosening (39.9%), infection (27.4%), instability (7.5%), periprosthetic fracture (4.7%), and arthrofibrosis (4.5%). Infection was the most common failure mechanism for early revision (<2 years from primary) and aseptic loosening was the most common reason for late revision. Polyethylene (PE) wear was no longer the major cause of failure. Compared to our previous report, the percentage of revisions performed for polyethylene wear, instability, arthrofibrosis, malalignment and extensor mechanism deficiency has decreased.

The Routine Use of Atypical Cultures in Presumed Aseptic Revisions Is Unnecessary

BackgroundIn presumed aseptic hip and knee revisions, it is common practice to send intraoperative cultures to screen for occult infection. Currently no guidelines exist for the routine use of acid-fast bacillus (AFB) and fungal cultures in this setting.Questions/purposesWe established (1) the rate of positive fungal and AFB cultures in aseptic hip and knee revision arthroplasties, (2) factors associated with positive fungal and AFB cultures, (3) the likelihood that positive cultures represent true-positive results, and (4) the hospital charges of sending fungal and AFB cultures routinely.MethodsWe retrospectively evaluated all 1717 presumed aseptic hip and knee revisions performed from January 2006 to November 2011: 1139 patients had at least one intraoperative fungal culture and 1133 patients had at least one intraoperative AFB culture, with 923 and 920, respectively, achieving 1-year followup. The Musculoskeletal Infection Society criteria were used to classify subsequent infections. We attempted to identify risk factors for positive cultures.ResultsWe observed six (0.5%) patients with positive AFB cultures and 19 (1.7%) with positive fungal cultures. Patients undergoing reimplantation procedures were more likely to have a positive fungal culture. The true-positive rate was 0% and 0.1% for AFB and fungal cultures, respectively. The total hospital charges for these cultures over the time frame of our study were USD 1,315,533.ConclusionsGiven the extremely low rate of true-positive AFB and fungal cultures in presumed aseptic revision joint arthroplasty and the charges associated with maintaining these cultures, we believe their routine use is unwarranted.Level of EvidenceLevel III, prognostic study. See the Instructions for Authors for a complete description of evidence.

Revision Total Hip Arthroplasty in Younger Patients: Indications, Reasons for Failure, and Survivorship

Abstract Increasing numbers of total hip arthroplasty (THA) procedures are being performed on younger patients, and the incidence of revision THA in this population is also increasing. The goals of our retrospective study were to survey the surgical indications and reasons for failure and survivorship of revision THA in patients aged < 50 years. We identified 139 cases of revision THA performed over a 6-year period in patients aged < 50 years. The most common reason for revision was aseptic loosening, followed by acetabular liner wear with or without osteolysis. We found an overall 10-year survivorship of 76%. When survivorship was stratified by the indication for revision surgery, revision for wear demonstrated the best 10-year survivorship, while revision for instability or infection exhibited poor survivorship.

Medicare Fails to Compensate Additional Surgical Time and Effort Associated with Revision Arthroplasty

In comparison to primary total knee arthroplasty, surgical time was 1.8 times greater for all knee revisions and 2.4 times greater for complex knee revisions. Knee revisions had an 8.5% higher rate of 90-day repeat procedures. In comparison to primary total hip arthroplasty, surgical time was 1.8 greater for all hip revisions and 2.6 fold greater for complex hip revisions. Hip revisions had a 3.4% higher rate of 90-day repeat procedures. Practices based on revisions or complex revisions alone would see a 32% and 50% decrease in reimbursement respectively compared to the ones based on primary arthroplasty. The projected future increase in primary arthroplasties and the relative incentive to perform primary arthroplasty may soon put patient access to physicians willing to perform revision arthroplasty at risk.

Clostridium difficile is Common in Patients With Postoperative Diarrhea after Hip and Knee Arthroplasty

Clostridium difficile is an antibiotic-associated gastrointestinal infection that has detrimental consequences. We sought to determine the incidence of C. difficile in TJA patients with postoperative diarrhea, to determine risk factors for C. difficile infection, and to establish the incidence of C. difficile-related complications. Our institutional protocol includes screening for C. difficile in all patients with diarrhea after TJA. We identified 121 such patients over four years with twenty-eight (23%) testing positive for C. difficile. Revision arthroplasty and prolonged postoperative antibiotic use were risk factors for C. difficile infection. With our protocol of screening and immediate treatment of C. difficile positive patients, we found no C. difficile-associated complications.

Dental Clearance Prior to Elective Arthroplasty May Not be Needed for Everyone

We investigated the prevalence and risk factors for preoperative dental clearance failure in joint arthroplasty patients. Over a 5-month period, all patients scheduling total joint arthroplasty completed a dental questionnaire. Data collected included demographics, medical and dental history, dental hygiene practices, frequency of dental care, and results of dental clearance. Of the 300 patients, 35 (12%) failed dental clearance. Risk factors included tobacco use, poor flossing habits, history of tooth extraction, age, narcotic use, and lack of a dentist visit within 12 months. Of 189 patients who lacked the 3 least prevalent risk factors (tobacco use, narcotic use, no dental visit within 12 months), 11 (6%) failed dental clearance. Selective dental clearance based on patient risk stratification may be a reasonable approach.

Perioperative skin preparation.

Liaison: Anthony T Tokarski BS Leaders: David Blaha MD (US), Michael A. Mont MD (US), Parag Sancheti MS, DNB, MCh (International) Delegates: Lyssette Cardona MD, MPH, MHA, AAHIVS, FIDSA, Gilberto Lara Cotacio MD, Mark Froimson MD, Bhaveen Kapadia MD, James Kuderna MD, PhD, Juan Carlos López MD, Wadih Y Matar MD, MSc, FRCSC, Joseph McCarthy MD, Rhidian Morgan-Jones MB BCh, FRCS, Michael Patzakis MD, Ran Schwarzkopf MD, Gholam Hossain Shahcheraghi MD, Xifu Shang MD, Petri Virolainen MD, PhD, Montri D. Wongworawat MD, Adolph Yates Jr, MD