The prevalence of fracture extension in displaced femoral neck fractures in the elderly: A pilot study.

Objective: Arthroplasty is the common treatment for intracapsular femoral neck fractures in the elderly. Recent studies have shown that there may be more overall complications related to uncemented hemiarthroplasty compared to cemented, including more subsidence, intraoperative fractures, and postoperative fractures. Uncemented femoral components rely on a press fit, and the risk of these complications would be expected to increase in patients with unrecognized distal extension of femoral neck fractures.

Mortality During Total Hip Periprosthetic Joint Infection.

Background: We sought to understand the mortality rate of periprosthetic joint infection (PJI) of the hip undergoing 2-stage revision for infection.

Methods: Database search, yielding 23 relevant studies, totaled 19,169 patients who underwent revision for total hip PJI.

Results: One-year weighted mortality rate was 4.

Mortality During Total Knee Periprosthetic Joint Infection.

Background: Periprosthetic joint infections (PJIs) are fraught with multiple complications including poor patient-reported outcomes, disability, reinfection, disarticulation, and even death. We sought to perform a systematic review asking the question: (1) What is the mortality rate of a PJI of the knee undergoing 2-stage revision for infection? (2) Has this rate improved over time? (3) How does this compare to a normal cohort of individuals?

Methods: We performed a database search in MEDLINE/EMBASE, PubMed, and all relevant reference studies using the following keywords: "periprosthetic joint infection," "mortality rates," "total knee arthroplasty," and "outcomes after two stage revision." Two hundred forty-two relevant studies and citations were identified, and 14 studies were extracted and included in the review.

Perivascular Stem Cells Diminish Muscle Atrophy Following Massive Rotator Cuff Tears in a Small Animal Model.

Background: Rotator cuff tears are a common cause of shoulder pain and often necessitate operative repair. Muscle atrophy, fibrosis, and fatty infiltration can develop after rotator cuff tears, which may compromise surgical outcomes. This study investigated the regenerative potential of 2 human adipose-derived progenitor cell lineages in a murine model of massive rotator cuff tears.

What is the frequency of vascular injury after knee dislocation?

Background: Vascular injury secondary to an acute knee dislocation is a known complication. However, there exist wide discrepancies in the reported rate of vascular injury in this setting.

Questions/purposes: Using a large private insurance database, we determined the frequency of vascular injury in knee dislocations across year of diagnosis, age, sex, and US geographic region and the proportion of these injuries requiring surgical repair.

MRI quantification of fatty infiltration and muscle atrophy in a mouse model of rotator cuff tears.

Rotator cuff pathology is the most common shoulder problem seen by orthopedic surgeons. Rotator cuff muscle fatty infiltration and muscle atrophy are common in larger tears and are considered predicting factors for the prognosis of cuff repair. Clinically, MRI is the gold standard in determining fatty infiltration and muscle atrophy; however, analysis for MRI imaging is primarily qualitative in nature with the results lacking further validation.

A mouse model of massive rotator cuff tears.

Background: Rotator cuff tears are the most common tendon injury seen in orthopaedic patients. Muscle atrophy and fatty infiltration in rotator cuff muscles are considered among the key factors responsible for the failure of attempted repair of a massive rotator cuff tear. However, the pathophysiology of rotator cuff muscle atrophy and fatty infiltration remains largely unknown, partly because of the lack of appropriate small animal models.

Loss of Pten causes tumor initiation following differentiation of murine pluripotent stem cells due to failed repression of Nanog.

Pluripotent stem cells (PSCs) hold significant promise in regenerative medicine due to their unlimited capacity for self-renewal and potential to differentiate into every cell type in the body. One major barrier to the use of PSCs is their potential risk for tumor initiation following differentiation and transplantation in vivo. In the current study we sought to evaluate the role of the tumor suppressor Pten in murine PSC neoplastic progression.

Role of gelatinases in disuse-induced skeletal muscle atrophy.

Gelatinases are a subgroup of the family of matrix metalloproteinases, which contains two members-gelatinase A and B. These enzymes play an important role in basement membrane homeostasis. Previous studies have associated basement membrane degradation with skeletal muscle atrophy.