David M. Hirsh

Recurrent infection of a total hip arthroplasty associated with radiation-induced ulcerative colitis: A case report

A case of recurrent sequential infections of a total hip implant in a patient with active radiation colitis is presented. The infections involve two distinctly different organisms, both of normal bowel flora. Though not recognized with orthopaedic implants, cases of bacteremic seeding with bowel flora to prosthetic implants such as heart valves have been reported. Treatment of this patient and the implications regarding management of patients with active bowel disease who plan to have hip arthroplasty are discussed.

Unipolar vs Bipolar Hemostasis in Total Knee Arthroplasty: A Prospective Randomized Trial

The purpose of this study was to investigate whether unipolar or bipolar hemostasis is more effective in reducing blood loss associated with primary total knee arthroplasty. We randomized 113 consecutive patients undergoing primary total knee arthroplasty into unipolar and bipolar hemostasis treatment groups. The mean postoperative drain output in the unipolar group was 776.5 mL compared with 778.7 mL and was not statistically significant (P = .97). There were no statistically significant differences in postoperative day 1 through 3 hemoglobin level (P = .2-.6) or hematocrit (P = .17-.46) values. The transfusion requirement in the unipolar group was 36% and 40% in the bipolar group (P = .67). Use of bipolar sealer compared with standard unipolar electrocauterization showed no significant difference in postoperative drain output, postoperative hemoglobin level and hematocrit values, or transfusion requirements.

Pain after total knee arthroplasty caused by soft tissue impingement

The usual causes of pain after total knee replacement are well known, but there are a small number of patients in whom its aetiology is obscure. We report three patients with a specific pain syndrome caused by hypertrophic fibrous tissue in the intercondylar notch. Excision of this tissue relieved the symptoms completely.

Histologic retrieval analysis of a porous tantalum metal implant in an infected primary total knee arthroplasty.

Porous tantalum (Zimmer, Inc, Warsaw, Ind) has the theoretical advantage of improved biologic fixation because of its high porosity, interconnected pore space, and modulus of elasticity. We present a case report documenting the retrieval and bone ingrowth analysis of a porous tantalum tibial component in an infected total knee arthroplasty. Results demonstrated a significantly larger amount of bone ingrowth present in the tibial posts (36.7%) when compared with the bone ingrowth into the tibial baseplate (4.9%) (P < .001). The data suggest that bone ingrowth seen in the plugs as well as baseplate was suggestive of viable bone tissue with healthy bone marrow, osteocytes, and lamella, resulting in a well-fixed tibial implant even at revision surgery for an infected total knee arthroplasty.

The Use of Dermabond® as an Adjunct to Wound Closure After Total Knee Arthroplasty: Examining Immediate Post-Operative Wound Drainage

Wound drainage after total knee arthroplasty (TKA) can be detrimental to surgical outcome. This IRB-approved randomized, prospective, blinded study examined the use of Dermabond® as an adjunct to wound closure after TKA. We proposed that Dermabond® supplementation to wound closure would result in a significant decrease in wound drainage after TKA. After standardized closure, patients were randomized into experimental or control groups with the experimental group receiving Dermabond® supplementation. Standardized dressings were evaluated postoperatively and drainage units were compared using a Mann-Whitney U Test. The median drainage for the Dermabond group (153) was lower than the drainage for the control group (657) at a statistically significant level (P<0.001).

Optimal Irrigation and Debridement of Infected Total Joint Implants with Chlorhexidine Gluconate

Previous study at our institution demonstrated that scrubbing a methicillin-resistant Staphylococcus aureus (MRSA)-coated titanium disk with chlorhexidine gluconate (CG) solution achieved superior biofilm eradication compared to alternative solutions. The current study aimed to identify the minimum CG concentration for effective bacteria eradication of an in vitro periprosthetic joint infection (PJI) model. MRSA colony-forming units (CFUs) were counted following simulated irrigation and debridement with varying CG solutions before and after a 24-hour reincubation period. Significant decrease was noted on all disks before reincubation. Postreincubation, significant decrease in CFUs was found in the 4% and 2% groups. This study demonstrated that I+D of an infected PJI model with 4% CG solution was effective at treating MRSA biofilm at concentrations as low as 2%.

Knee Arthrotomy Closure With Barbed Suture in Flexion Versus Extension: A Porcine Study

The purpose of this biomechanical study was to evaluate knee arthrotomy closure with a barbed suture in flexion versus extension. 48 porcine knees were randomized into three groups: full extension, 30° flexion, and 60° flexion. Each knee was then flexed to 90° and then 120°, with failures recorded. Arthrotomy closure in extension had significantly higher failure rates (6/16) upon flexion to 90° compared to arthrotomy closure in either 30° or 60° flexion (0/32) (P = 0.032). Upon ranging from 0° to 120°, arthrotomy failure occurred in 50% (8/16) of arthrotomies in the extension group, 6.25% (1/16) in the 30° flexion group and 18.75% (3/16) in the 60° flexion group (P = 0.022). Knee arthrotomy closure in extension compared to flexion had significantly higher rates of failure.

Procyanidins Mitigate Osteoarthritis Pathogenesis by, at Least in Part, Suppressing Vascular Endothelial Growth Factor Signaling

Procyanidins are a family of plant metabolites that have been suggested to mitigate osteoarthritis pathogenesis in mice. However, the underlying mechanism is largely unknown. This study aimed to determine whether procyanidins mitigate traumatic injury-induced osteoarthritis (OA) disease progression, and whether procyanidins exert a chondroprotective effect by, at least in part, suppressing vascular endothelial growth factor signaling. Procyanidins (extracts from pine bark), orally administered to mice subjected to surgery for destabilization of the medial meniscus, significantly slowed OA disease progression. Real-time polymerase chain reaction revealed that procyanidin treatment reduced expression of vascular endothelial growth factor and effectors in OA pathogenesis that are regulated by vascular endothelial growth factor. Procyanidin-suppressed vascular endothelial growth factor expression was correlated with reduced phosphorylation of vascular endothelial growth factor receptor 2 in human OA primary chondrocytes. Moreover, components of procyanidins, procyanidin B2 and procyanidin B3 exerted effects similar to those of total procyanidins in mitigating the OA-related gene expression profile in the primary culture of human OA chondrocytes in the presence of vascular endothelial growth factor. Together, these findings suggest procyanidins mitigate OA pathogenesis, which is mediated, at least in part, by suppressing vascular endothelial growth factor signaling.

Effects of intraoperative use of the topical hemostatic matrix agent, Floseal, in primary unilateral total knee arthroplasty

Background:Total knee arthroplasty can result in blood loss severe enough to require postoperative blood transfusions. Minimizing blood loss perioperatively is therefore essential to minimize morbidity in patients undergoing total knee arthroplasty. Floseal (Baxter International, Inc., Deerfield, IL) is a topical hemostatic matrix agent used for hemostasis during surgical operations. Methods:Patients undergoing routine total knee arthroplasty were randomized into two groups. One group received intraoperative standard hemostatic therapy and another group received intraoperative standard hemostatic therapy as well as Floseal. The groups were compared based on 24-hour postoperative drain output, 3-day postoperative drop in hematocrit and hemoglobin levels, and the incidence of postoperative transfusions. Results:One hundred and forty patients with primary unilateral total knee arthroplasties were recruited and 70 were randomized to the control group and 70 to the Floseal group. The mean 24-hour postoperative drain output for patients in the control group was 457.1 (+/−28.60) mL compared with 405.0 (+/−22.93) mL in the Floseal group. This difference was not significant (P=0.1651). Comparison of 3-day postoperative drops in hemoglobin and hematocrit values between the control and experimental groups also demonstrated no statistical significance (P=0.5422 and P=0.6524, respectively). The incidences of postoperative blood transfusions based on intraoperative use of Floseal were not significantly different (P=0.4389). Perioperative complications and their rates were not found to be changed with the intraoperative use of Floseal. Conclusions:Our data suggest that there is no benefit from the regular use of Floseal in routine total knee arthroplasty. Intraoperative use of Floseal in total knee arthroplasty did not increase complications and can likely be used safely.