Polyethylene liner fracture in dual mobility trapeziometacarpal total joint replacement: how to make a timely diagnosis?

We present a case of fracture of the polyethylene liner of a dual-mobility trapeziometacarpal total joint arthroplasty. Standard radiographic imaging was normal. This case highlights the importance of dynamic radiographic imaging to make a timely diagnosis.

Evaluation of MRI Signal Changes of the Distal Biceps Tendon in Asymptomatic Patients.

PURPOSE: Magnetic resonance imaging (MRI) is used widely for complete ruptures of the distal biceps tendon. The validity of this investigation for bicipital bursitis and tendinosis is unknown. The purpose of present study was to assess the prevalence of incidental (asymptomatic) signal changes in the distal biceps tendon in patients who underwent MRI including the elbow. Our null hypothesis was that signal changes of the distal biceps tendon do not occur in asymptomatic patients. This would empower MRI as a diagnostic tool for bicipital bursitis and tendinosis as well as complete and partial distal biceps tendon ruptures. METHODS: We evaluated 1,191 elbow MRI scans including the distal biceps tendon insertion. The prevalence of incidental findings was calculated and sensitivity, specificity, positive predictive value, negative predictive value, false positive probability, and false negative probability were calculated. RESULTS: Signal changes of the distal biceps tendon or bursitis were identified in 8 of 1,191 asymptomatic patients (prevalence 0.6%). The sensitivity of MRI for distal biceps pathology was 97% (95% confidence interval [CI], 93%-99%), specificity 99% (95% CI, 98%-99%), positive predictive value 94% (95% CI, 89%-97%), negative predictive value 99% (95% CI, 99%-99%), false positive probability 6% (95% CI, 3%-10%), and false negative probability 0.3% (95% CI, 0.1%-0.9%). There was no correlation between explanatory variables, including age, sex, race, occupation, and inflammatory disease and incidental distal biceps tendon signal changes. CONCLUSIONS: The prevalence of distal biceps tendon signal changes on MRI in asymptomatic patients is very low. CLINICAL RELEVANCE: The negative predictive value of 99% shows that patients without signal changes on MRI may be assumed to have no distal biceps tendon pathology. MRI investigation of distal biceps tendon is a valuable tool in the diagnosis of tendinosis and bicipital bursitis.