PJI is a devastating complication following total joint arthroplasty. In this study, we explore the efficacy of a bacteriophage-derived lysin, PlySs2, against
Introduction
Methods
Inflammation has been associated with immunological dysfunctions and chronic inflammatory diseases but is important for normal repair processes like bone healing. Macrophages (mØ) are important for bone growth, maintenance, and regeneration. MØ are distinct from other bone cells and play an important role in the inflammatory stage of bone healing. Previous data has shown that ablation of mØs during the inflammatory stage can severely impair bone healing and exacerbate bone loss in osteoporotic models. However, little research has focused on characterizing the mØ subtypes found during the inflammatory stage. We hypothesized that different mØ subtypes are activated during inflammation and release factors to regulate bone repair. Therefore, bone marrow was collected from mice femurs at days 0, 1, 2, 4, and 7 after fracture and mØ were isolated using established methods. MØ subtypes were identified using anti-F4/80, anti-CD80, and anti-CD86 antibodies via flow cytometry and cytokine expression was quantified using Luminex. When compared to unfractured controls, a 40–50% increase in MHC class II+/CD80+ double positive mØs and MHC class II+/CD86+ double positive mØs were found on day 2 post-fracture, which remained elevated through day 4 or 7, respectively. No differences were found in mØ populations between femurs in naïve (unfractured) mice. mØs of the fractured limbs expressed higher levels of cytokines overtime. Our results suggest that different subtypes of mØs are present during the inflammatory stage and may support diverse functions such as effertocytosis, chemotaxis, and tissue anabolism or catabolism, which provides insight into their contribution in normal or uncontrolled inflammatory related processes and conditions.
Version abnormalities of the femur, either retroversion or excessive anteversion, cause pain and hip joint damage due to impingement or instability respectively. A retrospective clinical review was conducted on patients undergoing a subtrochanteric derotation osteotomy for either excessive anteversion or retroversion of the femur. A total of 49 derotation osteotomies were performed in 39 patients. There were 32 females and 7 males. Average age was 29 years (range 14 to 59 years). Osteotomies were performed closed with an intramedullary saw (Figure 1). Fixation was performed with a variety of intramedullary nails. Patients requiring a varus or valgus intertrochanteric osteotomy were excluded. Pure rotational corrections only were performed. Twenty-four percent of patients had a retroversion deformity (average −8° retroversion, range +1 to −23°), 76% had excessive anteversion of the femur (average +36° anteversion, range +22° to +53°). Etiology was post-traumatic in 5 (10%), diplegic cerebral palsy in 4 (8%), fibrous dysplasia in 2 (4%), Prader-Willi Syndrome in 1 (2%) and idiopathic in 37 (76%). Previous surgery had been performed in 51% of hips. Fifty-seven percent underwent concomitant surgery with the index femoral derotation osteotomy, including hip arthroscopy in 39% (labral debridement alone or with femoral neck osteochondroplasty), a tibial derotation osteotomy in 12% and periacetabular osteotomy in 6%. Concomitant tibial osteotomies were performed to correct a compensatory excessive external tibial torsion that would be exacerbated in the correction of excessive femoral anteversion. The modified Harris Hip Score was used to assess the results in patients with a minimum of 24 months follow-up.Introduction
Methods
