Cutibacterium acnes (formerly Proprionibacterium acnes) and Shoulder Surgery

Infection is a rare but serious complication of shoulder arthroplasty. The most prevalent cause of patient infections is Cutibacterium acnes (formerly Proprionibacterium acnes), a commensal skin bacterial species. Its presentation is often non-specific and can occur long after shoulder arthroplasty, leading to delay in diagnosis. This bacterium is difficult to culture, typically taking 14 to 17 days for a positive culture and often does not exhibit abnormal results on a standard laboratory workup for infection (eg, ESR, CRP, and synovial WBC count). Male patients are at particularly high-risk due to having a greater number of sebaceous follicles than females. While it is difficult to diagnose, early diagnosis can lead to decreased morbidity, appropriate treatment, and improved clinical outcomes. Current options for treatment include antibiotics, one stage implant exchange, or two stage implant exchange, although success rates of each are not currently well described. A better understanding of the prevention, diagnosis, and treatment of C. acnes infection could lead to better patient outcomes from shoulder arthroplasty.

Denosumab-Associated Peri-Implant Atypical Femur Fracture: A Case Report

Bisphosphonate use has been associated with atypical pathologic fracture and slowed bone turnover. We present a case of a bisphosphonate-associated peri-implant atypical femur fracture following use of a recon nail for treatment of a prior bisphosphonate-associated atypical femur fracture.

A Comparison of Skeletal Injuries Arising from Moped and Motorcycle Collisions

Motorcycle and moped injuries remain a significant cause of motor-vehicle related morbidity and mortality. There is a paucity of literature describing the skeletal injuries of moped riders and how these compare to those of motorcyclists, however. This study seeks to examine the skeletal injuries sustained in such incidents and determine if there are significant differences. Hospitalized riders injured on powered two-wheeled vehicles (PTW) between 2004 and 2007 were entered into a registry along with their presentation and clinical course. This registry was sorted by PTW type. Riders with injuries of the appendicular skeleton, bony pelvis, and spine were extracted. Injuries were categorized by bone location. Demographic data, helmet use, head injury, facial fracture, Injury Severity Score (ISS), and mortality were extracted. Overall, 406/578 motorcyclists, 197/357 moped riders, and 62/92 dirt-bike riders sustained fractures of the appendicular skeleton, pelvis and/or spine. Motorcyclists had a significantly higher ISS upon presentation and had increased first-hospital day mortality in addition to more skeletal injuries, more fractures of the upper extremity, and more fractures of the spine, pelvis, and foot. Moped riders had a significantly lower rate of helmet use and higher rate of head injuries and facial fractures. In summary, while both moped and motorcycle riders share a risk for injuries of the lower extremity, their overall pattern of injury differs. Motorcyclists appear to be at increased risk for more severe injuries and injuries of the upper extremity, spine, and pelvis, while moped riders are at increased risk for significant head and facial injury.