Current Options and Emerging Biomaterials for Periprosthetic Joint Infection

Purpose of Review

Infection in the setting of total joint arthroplasty, referred to as periprosthetic joint infection (PJI), is a devastating complication requiring prolonged and costly treatment. The unique environment around an artificial joint and ability of surrounding tissues to sequester bacteria collectively make prevention, diagnosis, and treatment of this condition challenging. In light of the unique pathogenesis of PJI, this review explores the limitations of contemporary treatments and discusses novel treatment options.

Recent Findings

Recent advancements in local antibiotic delivery platforms for preventing and treating PJI include titanium nanotube arrays, synthetic polymers, resorbable hydrogels, and cyclodextrin-based drug delivery options. In particular, cyclodextrins have facilitated great advancements in other clinical disorders and have demonstrated early promise as a future option in the arena of PJI.

Summary

Novel treatment modalities for PJI optimize the implant surfaces to prevent bacterial biofilm formation or provide prolonged intra-articular antibiotic dosing to eradicate bacteria.

     

Trochlear Inclination Angles in Normal and Dysplastic Knees

Trochlear morphology impacts component position in patellofemoral arthroplasty. We devised a measurement of the trochlear inclination angle (TIA) and determined the average TIA in normal and dysplastic knees. Three hundred twenty-nine consecutive magnetic resonance imagings of normal and dysplastic knees were evaluated. The TIA was measured by 2 reviewers. The Student t test was used, and intraobserver reliability measurements were made. The mean TIA in normal and dysplastic knees was internally rotated 11.4° (range, 6°-20°) and 9.4° (range, 4°-15°), respectively. The mean TIA did not differ significantly by sex or age. Trochlear inclination angles in both normal and dysplastic knees tend toward internal rotation. Positioning a trochlear patellofemoral arthroplasty component flush with the articular surface of the native trochlea would result in internal rotation malposition.     

Presence of macrophages at the bone-cement interface of stable hip arthroplasty components

The bone cement interface of four clinically stable hip-joint prosthetic components was examined histologically for the presence of macrophages using routine staining and a histochemical technique for acid phosphatase. Macrophages were found in the absence of wear debris in all four cases. Because these cells are capable of bone resorption, their presence at a well-fixed interface must give cause for concern.     

Carotid artery thrombosis and delayed stroke associated with the use of a shoulder belt in a teenager

Blunt carotid artery injury caused by shoulder belts is rare and requires a high index of suspicion to diagnose before the onset of neurologic sequelae. Neurologic abnormalities may be erroneously attributed to concomitant head trauma, and the onset of neurologic abnormalities may be delayed for hours or days. The case of a young, teenaged driver with a “seatbelt sign” and presentation of signs and symptoms of carotid artery thrombosis 13 days after injury is described. Occult vascular injury should be suspected if neurologic deterioration occurs after a lucid interval and/or computed tomography of the head is inconsistent with neurologic findings. Screening criteria and possible screening modalities are discussed.