Hyaluronic acid injections for osteoarthritis of the knee: predictors of successful treatment.

PURPOSE: This study aimed to identify patient and treatment factors that predict a favourable response to intra-articular hyaluronic acid (HA) treatment to better guide patient and treatment selection. METHODS: This prospective, observational study evaluated patients with mild-to-moderate (Kellgren-Lawrence grades 1-3) primary knee osteoarthritis treated between March 2013 and May 2016. Patient function and pain scores were assessed by the Western Ontario and McMaster Universities Arthritis Index/Knee Injury and Osteoarthritis Outcome Score (WOMAC/KOOS) and visual analogue scale (VAS) surveys, with response to treatment defined according to the Osteoarthritis Research Society International (OARSI) 2004 criteria. Surveys were completed at each injection and three months post-treatment. Patients were followed an average of 27 months. RESULTS: Of 102 patients, 57% had a positive response. Those at least twice as likely to respond were patients with grades 1-2 osteoarthritis or a positive response to the first injection and those who were ≥60 years. Gender, race, body mass index (BMI), smoking status, HA brand, and initial VAS and WOMAC/KOOS scores were not significant predictors of success. Mean time to arthroplasty following injection series was 11 months (30% of nonresponders, 12% of responders). The VAS strongly correlated with KOOS pain scores and successful outcomes. CONCLUSION: Patients with mild-to-moderate osteoarthritis (grades 1-2) and those responding positively to the first injection were twice as likely to respond positively to the injection series, as were patients ≥60 years. Patients who did not respond positively were more likely to proceed to arthroplasty. The VAS appears to be a reliable method of defining and monitoring treatment success. Judicious patient selection and counseling may improve outcomes associated with intra-articular HA injections.

Partial Rotator Cuff Repair for Massive Tears Rarely Require Revision Surgery.

PURPOSE: To determine the significance of initial and residual rotator cuff tear defect size on the need for revision surgery or additional nonsurgical therapy, in a consecutive group of patients undergoing partial repair of massive rotator cuff tears. METHODS: A retrospective chart review was carried out for all arthroscopic rotator cuff repairs performed by a single surgeon between January of 2013 and December of 2016. All patients with massive rotator cuff tears (>30 cm2) who underwent partial repair were included in the study. Outcomes for the surgical procedure were measured based on the necessity for revision surgery or adjunct therapy, including steroid injections or additional physical therapy after initial release from care. RESULTS: In total, 1954 patients who underwent arthroscopic rotator cuff repair were identified. Thirty-eight of these met the inclusion criteria. Those patients undergoing revision surgery represented 5.2% (2/38) of the series and had an average initial/residual tear defect area of 45.0/7.0 cm2. Patients requiring adjunct therapy represented 7.9% (3/38) of the series and possessed an average initial/residual tear defect size of 40.0/16.0 cm2. The remaining 33 (86.9%) patients did not require revision surgery or adjunct therapy at a minimum follow-up of 2 years. There was no significance between initial and/or residual rotator cuff tear defect size and the need for revision surgery. However, there was a significant difference in the mean residual defect size in the patients requiring additional nonoperative treatment after initial release from care (P = .012). CONCLUSIONS: There was no relationship between residual defect size after partial repair and the need for revision surgery. Patients who returned for additional nonoperative treatment after being released from care were noted to have a statistically larger residual defect size at the time of index surgical intervention. Only 5% of patients underwent subsequent surgery at an average of more than 4 years' follow-up, suggesting that partial repair of massive rotator cuff tears can provide a durable, joint-preserving intervention. LEVEL OF EVIDENCE: Level IV, Therapeutic Case Series.

Preoperative Narcotic Use and Inferior Outcomes After Anatomic Total Shoulder Arthroplasty: A Clinical and Radiographic Analysis.

INTRODUCTION: Our purpose was to determine whether the chronic use of preoperative narcotics adversely affected clinical and/or radiographic outcomes. METHODS: Seventy-three patients (79 shoulders) with primary total shoulder arthroplasty for osteoarthritis were evaluated clinically and radiographically at preoperative visits and postoperatively at a minimum follow-up of 2 years: 26 patients (28 shoulders) taking chronic narcotic pain medication for at least 3 months before surgery and 47 patients (51 shoulders) who were not taking narcotics preoperatively. RESULTS: Postoperatively, significant differences were noted between the narcotic and nonnarcotic groups regarding American Shoulder and Elbow Surgeons scores and visual analog scale scores, as well as forward elevation, external rotation, and all strength measurements (P < 0.01). The nonnarcotic group had markedly higher American Shoulder and Elbow Surgeons scores, better overall range of motion and strength, and markedly lower visual analog scale scores than the narcotic group. CONCLUSION: Chronic preoperative narcotic use seems to be a notable indicator of poor outcomes of anatomic total shoulder arthroplasty for glenohumeral osteoarthritis.

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.

Ligaments of the craniocervical junction.

The specialized ligaments of the craniocervical junction must allow for stability yet functional movement. Because injury to these important structures usually results in death or morbidity, the neurosurgeon should possess a thorough understanding of the anatomy and function of these ligaments. To the authors' knowledge, a comprehensive review of these structures is not available in the medical literature. The aim of the current study was to distill the available literature on each of these structures into one offering.