Stemless Humeral Implants in Total Shoulder Arthroplasty.

Through an iteration of various advancements, both short stem and stemless options for humeral fixation have been proposed and have shown clinical promise. The proposed benefits of a stemless humeral implant include greater bone preservation, less stress shielding, less risk of a diaphyseal stress riser, decreased surgical time, and less intraoperative blood loss. Potential downsides include the dependence on proximal bone quality for fixation, increased cost, the dependence on the strength of subscapularis fixation, and pending FDA approval for multiple implants. The purpose of this article is to review the evidence behind stemless implants including the biomechanical advantages and disadvantages, surgical technique, and clinical outcomes.

Prevention, Reduction, and Stabilization of Dog-Ear Deformities During Arthroscopic Rotator Cuff Repair.

Arthroscopic rotator cuff repairs (ARCRs) are common procedures that have been increasing in incidence. When performing ARCR, the surgeon often identifies an undesirable flap or fold, referred to as a "dog-ear" deformity, between sutures or knots. The height and/or thickness of a dog-ear deformity may decrease the rotator cuff-to-acromion distance, resulting in possible impingement and repair compromise. Furthermore, the goal of ARCR is to achieve complete restoration of the tendon-to-footprint relation. To restore the entire footprint, this lesion must be reduced and stabilized. We present a technique using looped sutures to augment the rotator cuff repair and prevent dog-ear formation.

Technique for Double Row Superior Capsule Reconstruction with Dermal Allograft.

Superior capsular reconstruction (SCR) is increasingly being used as a procedure for addressing irreparable rotator cuff tears. The procedure was initially described for failed rotator cuff repairs where the retears are severely retracted and when grade 3-4 fatty infiltration and atrophy exist. The SCR procedure can also be considered for irreparable rotator cuff tears in patients that are either too young or too high demand to be appropriate candidates for arthroplasty. Early short and medium term follow up studies support SCR with favorable outcomes compared with other salvage procedures.

Intraoperative Topical Antibiotics for Infection Prophylaxis in Pelvic and Acetabular Surgery.

OBJECTIVES: To determine if topical vancomycin and tobramycin powder reduces the incidence of surgical site infection after pelvic ring and acetabulum fracture surgery. DESIGN: Retrospective cohort study. SETTING: University of Alabama at Birmingham, Academic Level I Trauma Center. PATIENTS/PARTICIPANTS: Two hundred nineteen patients (140 meeting inclusion criteria) with pelvic and acetabular fractures who underwent open reduction and internal fixation from March 2012 to November 2013. INTERVENTION: One gram vancomycin and 1.2 g tobramycin powder applied deep in the surgical wound of the treatment group. MAIN OUTCOME MEASUREMENTS: Postoperative infection rate. RESULTS: One hundred forty patients were included. Control group (n = 69) and treatment group (n = 71) were similar for sex, age, ethnicity, and body mass index. There was no difference between groups with regards to renal function postoperative day 2 (P = 0.24). The risk of infection was 14.5% and 4.2% (P = 0.04) for the control and treatment groups, respectively. No significant effect of antibiotic treatment was observed overall after adjusting for EBL (odds ratio 0.20, 95% confidence interval, 0.02-1.06). Of note, a nonsignificant 71% increase was observed among those with ≥1 L EBL (odds ratio 1.71, 95% confidence interval, 0.02-147.02). CONCLUSIONS: Topical antibiotics possibly reduce the incidence of surgical site infection after open pelvic and acetabulum fixation without increasing risk of renal impairment. The protective effect of topical antibiotics may be limited to patients with minimal intraoperative blood loss. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

AB5075, a Highly Virulent Isolate of Acinetobacter baumannii, as a Model Strain for the Evaluation of Pathogenesis and Antimicrobial Treatments.

UNLABELLED: Acinetobacter baumannii is recognized as an emerging bacterial pathogen because of traits such as prolonged survival in a desiccated state, effective nosocomial transmission, and an inherent ability to acquire antibiotic resistance genes. A pressing need in the field of A. baumannii research is a suitable model strain that is representative of current clinical isolates, is highly virulent in established animal models, and can be genetically manipulated. To identify a suitable strain, a genetically diverse set of recent U.S. military clinical isolates was assessed. Pulsed-field gel electrophoresis and multiplex PCR determined the genetic diversity of 33 A. baumannii isolates. Subsequently, five representative isolates were tested in murine pulmonary and Galleria mellonella models of infection. Infections with one strain, AB5075, were considerably more severe in both animal models than those with other isolates, as there was a significant decrease in survival rates. AB5075 also caused osteomyelitis in a rat open fracture model, while another isolate did not. Additionally, a Tn5 transposon library was successfully generated in AB5075, and the insertion of exogenous genes into the AB5075 chromosome via Tn7 was completed, suggesting that this isolate may be genetically amenable for research purposes. Finally, proof-of-concept experiments with the antibiotic rifampin showed that this strain can be used in animal models to assess therapies under numerous parameters, including survival rates and lung bacterial burden. We propose that AB5075 can serve as a model strain for A. baumannii pathogenesis due to its relatively recent isolation, multidrug resistance, reproducible virulence in animal models, and genetic tractability. IMPORTANCE: The incidence of A. baumannii infections has increased over the last decade, and unfortunately, so has antibiotic resistance in this bacterial species. A. baumannii is now responsible for more than 10% of all hospital-acquired infections in the United States and has a >50% mortality rate in patients with sepsis and pneumonia. Most research on the pathogenicity of A. baumannii focused on isolates that are not truly representative of current multidrug-resistant strains isolated from patients. After screening of a panel of isolates in different in vitro and in vivo assays, the strain AB5075 was selected as more suitable for research because of its antibiotic resistance profile and increased virulence in animal models. Moreover, AB5075 is susceptible to tetracycline and hygromycin, which makes it amenable to genetic manipulation. Taken together, these traits make AB5075 a good candidate for use in studying virulence and pathogenicity of this species and testing novel antimicrobials.

Failure and salvage of "INFIX" instrumentation for pelvic ring disruption in a morbidly obese patient.

Open-book pelvic fractures in the obese patient are accompanied by an increased risk of fixation failure. We report on the use of a recently described anterior subcutaneous pelvic internal fixator, the "INFIX" technique, in a morbidly obese patient. In this case, single and double rod constructs alone did not maintain adequate fixation due to the extreme forces in a morbidly obese patient. Successful salvage of the construct and satisfactory healing was achieved with the addition of 2 cross-links between the double rods of the INFIX.