Efficacy and Cost-effectiveness of Topical Vancomycin Powder in Primary Cementless Total Hip Arthroplasty.

Topical vancomycin has been shown to effectively reduce infections after spinal surgery while remaining safe and cost-effective; however, there are few studies evaluating topical vancomycin in total hip arthroplasty. The authors hypothesized that the incidence of periprosthetic joint infection would decrease with the use of topical vancomycin in total hip arthroplasty and that topical vancomycin would be cost-effective. A retrospective patient chart review was performed to evaluate consecutive primary cementless total hip arthroplasties performed in the authors' hospital system between April 2015 and December 2016. Demographic data were collected. Periprosthetic joint infection was defined by Musculoskeletal Infection Society criteria. Statistical analysis included t test, Fisher's exact test, and logistic regression. The costs of vancomycin and postoperative infection were used to determine the absolute risk reduction (1/number needed to treat) threshold needed for topical vancomycin to be cost-effective. In this study, 309 patients (55.7%) undergoing total hip arthroplasty were treated with topical vancomycin, and 246 patients (44.3%) did not receive treatment. There were 2 infections in the vancomycin group (0.6% incidence), and 4 in the no vancomycin group (1.6% incidence). There was no statistical difference in infection rate between the 2 cohorts (P=.414). The absolute risk reduction was 0.98%, and the number needed to treat with topical vancomycin was 102 patients to prevent 1 periprosthetic joint infection. Topical vancomycin ($12 per vial) resulted in an expected cost savings of $904 per patient. Topical vancomycin is inexpensive and cost-effective. Although not statistically significant, the topical vancomycin group had a 60% lower incidence of infection. Further research regarding appropriate prophylactic topical and intravenous antibiotic use is needed prior to widespread adoption. [Orthopedics. 2019; 42(5):e430-e436.].

Cobalt toxicity after revision to a metal-on-polyethylene total hip arthroplasty for fracture of ceramic acetabular component.

Cobalt metallosis after revision metal-on-polyethylene total hip arthroplasty for catastrophic failure of ceramic components is uncommon but a potentially devastating complication. Common findings associated with heavy metal toxicity include cardiomyopathy, hypothyroidism, skin rashes, visual disturbances, hearing changes, polycythemia, weakness, fatigue, cognitive deterioration, and neuropathy. We report a case of a 57-year-old woman who presented with complaints of progressively worsening hip pain, fatigue, memory loss, lower extremity sensory loss, persistent tachycardia, and ocular changes 5 years after synovectomy and revision of a failed ceramic-on-ceramic total hip arthroplasty to metal-on-polyethylene components. A cobalt level of 788.1 ppb and chromium level of 140 ppb were found on presentation and subsequently decreased to 468.8 ppb and 105.9 ppb, respectively, 2 weeks after revision to a ceramic-on-polyethylene total hip arthroplasty. Improvement of symptoms accompanied this decrease in cobalt and chromium levels. Revision of failed ceramic arthroplasties with later-generation ceramics to avoid this potential complication is recommended.

Early catastrophic failure of trochanteric fixation with the Dall-Miles Cable Grip System.

Multi-filament orthopaedic cerclage cables have been used in clinical practice for several decades, and are commonly utilized to provide greater trochanteric fixation following an osteotomy or fracture. We present the first known report of patients who experienced early catastrophic failure following use of the Dall-Miles Cable Grip System (DMCGS). A root cause analysis determined that the jaws of one crimper had an increased distance at closure, resulting in inadequate ultimate fixation strength. It was discovered that operating room staff had not been trained to perform regular calibration checks and the required calibration tool was not included in any of the institution's DMCGS sets. Surgeons should be aware that these surgical instruments require regular maintenance and should be gauge tested prior to every use.

An improved method for cable grip fixation of the greater trochanter after trochanteric slide osteotomy.

This study proposes a novel method for reattachment of the trochanteric slide osteotomy. The strength of this new fixation system was compared to established configurations. Fifteen sawbone femurs were used. Our configuration used cables above and below the lesser trochanter with a third cable around the shaft of the femur while passing the loose ends through the inferior hole of the cable grip. Displacement of the trochanter was measured with increasing load. Force required for catastrophic failure was also measured. The 3-cable construct resulted in significantly less displacement with increasing load and required a larger force to cause failure (1 cm and 2 cm). We theorize that our configuration produces a biomechanically stronger construct than previously used methods.

Modular femoral stem-sleeve junction failure after primary total hip arthroplasty.

The total hip prosthesis has evolved from the initial monoblock system developed by Charnley. Modularity of both the femoral and acetabular components, which allows the surgeon to assemble the prostheses just before or during the course of implantation, has now become standard. Modularity increases the number of implant parameter variables, allowing semicustom devices to be constructed. Component interfaces, however, are subject to significant stresses, micromotion manifesting as fretting, may produce wear debris, and at times may experience macromotion leading to catastrophic failure. We report 3 cases of stem-sleeve junction failure in otherwise uncomplicated primary total hip arthroplasties. Two of the failures occurred in the S-ROM (Joint Medical Products, Stamford, Conn) femoral stem design and the other in an Apex stem (Omni Life Science, Raynham, Mass). To our knowledge, there have been no previous reports of clinical failures at femoral stem-sleeve junction.

Massive retroperitoneal hematoma during enoxaparin treatment of pulmonary embolism after primary total hip arthroplasty: case reports and review of the literature.

In light of the increasing use of enoxaparin for both prophylaxis and treatment of thromboembolic disease, the number of potential complications from this anticoagulant will also continue to increase. This article presents the first case of massive retroperitoneal hematoma during enoxaparin treatment of pulmonary embolism after a primary total hip arthroplasty and discusses several unique sequelae of the retroperitoneal hematoma. Retroperitoneal hematomas are often fatal, and treatment involves aggressive fluid resuscitation with possible surgical decompression.