Perioperative periprosthetic femur fracture associated with direct anterior total hip arthroplasty using metaphyseal fit and fill stem

INTRODUCTION

This study aims to identify radiographic and clinical risk factors of perioperative periprosthetic femur fracture associated with the direct anterior approach (DAA) using a metaphyseal fit and fill stem. We hypothesize stem malalignment with this femoral implant places increased stress on the medial calcar region, which leads to an increased risk of periprosthetic fracture.

METHODS

We compared patients with periprosthetic femur fractures following DAA total hip arthroplasty (THA) utilizing the Echo Bi-Metric Microplasty Stem (Zimmer Biomet, Warsaw, IN) to a cohort of patients who did not sustain a periprosthetic fracture from five orthopedic surgeons over four years. Postoperative radiographs were evaluated for stem alignment, neck cut level, Dorr classification, and the presence of radiographic pannus. Univariate and logistic regression analyses were performed. Demographic and categorical variables were also analyzed.

RESULTS

Fourteen hips sustained femur fractures, including nine Vancouver B2 and five AG fractures. Valgus stem malalignment, proud stems, extended offset, and patients with enlarged radiographic pannus reached statistical significance for increased fracture risk. Low femoral neck cut showed a trend toward statistical significance.

CONCLUSION

Patients undergoing DAA THA using a metaphyseal fit and fill stem may be at increased risk of perioperative periprosthetic fracture when the femoral stem sits proudly in valgus malalignment with extended offset and when an enlarged pannus is seen radiographically. This study identifies a specific pattern in the Vancouver B2 fracture cohort with regard to injury mechanism, time of injury, and fracture pattern, which may be attributed to coronal malalignment of the implant.

Utilization of minimally invasive burr for surgical correction of calcaneus fracture malunion: A case report describing a novel technique

INTRODUCTION

Calcaneus fractures pose a significant treatment challenge to orthopaedic surgeons. Nonoperative treatment frequently leads to malunion, persistent pain, and development of subtalar arthritis, while operative treatment increases the risk of surgical-related complications, such as surgical site infection, without demonstrating superior outcomes.

PRESENTATION OF CASE

A 58-year-old male laborer presented three months after sustaining a left joint-depression type calcaneus fracture. He was initially treated nonoperatively but suffered from significant pain and dysfunction interfering with activities of daily living and inability to return to work. The patient was treated with a novel technique utilizing a minimally invasive burr to correct calcaneus fracture malunion. There were no reported post-operative complications, including infection or additional malunion, patient has returned to normal shoewear and his physically demanding career.

DISCUSSION

This is one of few studies documenting utilization of a minimally invasive burr for surgical correction of calcaneus fracture malunion. Restoration of calcaneal height and hindfoot alignment were achieved without evidence of subtalar arthritis on postoperative radiographs. Minimally invasive surgical procedures, especially with smaller incisions, have been found to be just as effective as open, though with significantly fewer wound and nerve complications.

CONCLUSION

Minimally invasive correction of calcaneus fracture malunion may be a viable option for surgical intervention, even in patients who are at higher risk of surgical complications such as infection. The indications for minimally invasive techniques are rapidly expanding and further studies are warranted to evaluate the use of minimally invasive techniques in foot and ankle surgery.

A Rare Case of Prosthetic Joint Infection with Streptococcus gordonii

BACKGROUND Chronic prosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty, resulting in significant morbidity and mortality. The criterion standard of treatment for chronic PJI is two-stage revision arthroplasty consisting of complete hardware removal, thorough irrigation and debridement, placement of an antibiotic spacer, prolonged intravenous antibiotics based on culture sensitivities, and revision total knee arthroplasty once the infection resolves. The most common organism implicated in chronic PJI is Staphylococcus aureus. CASE REPORT In this report, we have summarized the case of a 75-year-old woman who developed chronic PJI caused by an unusual organism, Streptococcus gordonii, 1 year after a right total knee arthroplasty. S. gordonii is a gram-positive organism that is an oral flora and a colonizer of human teeth. This organism is known to create biofilm on the human teeth, more commonly known as dental plaque. S. gordonii has the ability to travel to extraoral sites and cause infection. It has been found to be a cause of subacute bacterial endocarditis, but it has been rarely described in the literature as a cause of prosthetic joint infection. Treatment of S. gordonii requires a tailored approach. CONCLUSIONS This case report highlights the clinical presentation, diagnosis, and treatment of chronic prosthetic joint infection caused by S. gordonii and identifies a rare cause of PJI that is not well documented in the literature. Streptococcal PJI portends a poorer prognosis, and identification of this organism is crucial for prompt treatment and improved outcomes for PJI.

Occult clavicle osteomyelitis caused by Cutibacterium acnes (C. acnes) after coracoclavicular ligament reconstruction: A case report and review of the literature

INTRODUCTION

Clavicle osteomyelitis is a rare, but serious complication following operative repair of acromioclavicular (AC) joint separations. Cutibacterium Acnes (C. acnes) is rarely a causative pathogen in clavicle osteomyelitis and diagnosis can be challenging due to the indolent nature of this organism.

CASE PRESENTATION

A 45-50 year old female with a chronic AC joint separation underwent an open coracoclavicular reconstruction using semitendinosus allograft and FiberTape (Arthrex, Naples, FL). At the six month follow up, the patient complained of mild persistent pain. Imaging demonstrated widening of the medial suture tunnel with distal clavicle osteolysis, which was concerning for osteomyelitis. This was successfully treated with implant removal revision surgery and additional intravenous antibiotics. Cultures of the graft material were positive for C. acnes. The patient continued to have osteolysis of the distal left clavicle for a period of time despite resolution of osteomyelitis.

DISCUSSION

C. acnes osteomyelitis of the clavicle is difficult to diagnose because of its vague associated symptoms when implicated in infections. There are no known obvious predisposing factors for C. acnes clavicle osteomyelitis. Literature suggests management should include aggressive irrigation and debridement, removal of any hardware, and extended intravenous antibiotic administration.

CONCLUSION

C. acnes clavicular osteomyelitis is uncommon, thus established treatment guidelines have not yet been formed. Revision surgery to remove graft material, irrigate, and debride in addition to antibiotic treatment was successful for our patient. Additional pathologic manifestations of C. acnes infections could include continued clavicular erosion post-clearance of infection, although further investigation is necessary.

Dogs Entering the United States from Rabies-Endemic Countries, 2011-2012

International dog imports pose a risk because of the potential movement of disease agents, including the canine rabies virus variant which has been eliminated from the United States since 2007. US regulations require a rabies vaccination certificate for dogs arriving from rabies-endemic countries, but permit the importation of dogs that have not been adequately immunized against rabies, provided that the dogs are confined under conditions that restrict their contact with humans and other animals until they have been immunized. CDC Form 75.37, 'Notice to Owners and Importers of Dogs', explains the confinement requirements and serves as a binding confinement agreement with the importer. In this evaluation, we describe the characteristics of unimmunized dogs imported into the United States over a 1-year period based upon dog confinement agreements recorded at the Centers for Disease Control and Prevention (CDC) quarantine stations. Confinement agreements were issued for nearly 2800 unimmunized dogs that entered the United States during 1 June 2011-31 May 2012, the majority of which travelled to the United States by air and without any seasonal pattern in import volume. Over 60% of these animals were puppies <3 months of age and included a wide variety of breeds. The dogs arrived from 81 countries, with the majority arriving from North America or Europe. Dogs placed on confinement agreements had final destinations in 49 states. California, New York, Texas, Washington and Florida received the largest number of dogs on confinement agreements. These results (which do not reflect human travel or US dog ownership data) suggest that a large portion of unimmunized dogs arrive from rabies-endemic countries for commercial, shelter and rescue purposes. Further evaluation and key stakeholder involvement are needed to assess whether the current dog importation regulations are an adequate compromise between the benefits and risks of dog importation.

Two-year report of sealant effect on bacteria in dental caries

Teeth in which caries had penetrated the pits and fissures were sealed with an ultraviolet-light-polymerized sealant. Samples of carious dentin were taken from teeth that were not sealed and from teeth that were sealed, up to two years after the sealant had been placed. The major reduction in viable microorganisms occurred during the first two weeks, and there was a gradual reduction in the total count thereafter. At the end of two years, there was a 2,000-fold decrease in the number of cultivable microorganisms. Preliminary clinical and radiographic findings suggest that there was no progression of the carious lesions, but further studies are needed before this technique can be considered an alternative to conventional procedures.