Pang-Hsin Hsieh

Two-Stage Revision Hip Arthroplasty for Infection: Comparison Between the Interim Use of Antibiotic-Loaded Cement Beads and a Spacer Prosthesis

BACKGROUND A two-stage revision is a well-accepted method for the treatment of a deep infection of a hip with a joint implant. In the present study, the results associated with the interim use of antibiotic-loaded cement beads were compared with those associated with the interim use of an antibiotic-loaded cement prosthesis. METHODS One hundred and twenty-eight consecutive patients who were managed with a two-stage revision hip arthroplasty for the treatment of an infection were followed clinically and radiographically for an average of 4.9 years. Cement beads were implanted following resection arthroplasty in the first seventy hips, and a custom cement prosthesis was implanted in the subsequent fifty-eight hips. RESULTS There was no evidence of recurrent infection in 122 patients (95.3%); the infection-free rates in both groups were similar. The use of a spacer prosthesis was associated with a higher hip score, a shorter hospital stay, and better walking capacity in the interim period; a decreased operative time, less blood loss, and a lower transfusion requirement at the time of reimplantation; and fewer postoperative dislocations. CONCLUSIONS The present study supports the safety and efficacy of the routine use of an antibiotic-loaded cement prosthesis in the interim between the stages of a two-stage revision procedure for the treatment of an infection at the site of a hip arthroplasty.

Gram-negative Prosthetic Joint Infections: Risk Factors and Outcome of Treatment

BACKGROUND Little information is available regarding the demographic characteristics and outcomes of patients with prosthetic joint infection (PJI) resulting from gram-negative (GN) organisms, compared with patients with PJI resulting from gram-positive (GP) organisms. METHODS We performed a retrospective cohort analysis of all cases of PJI that were treated at our institution during the period from 2000 through 2006. RESULTS GN microorganisms were involved in 53 (15%) of 346 first-time episodes of PJI, and Pseudomonas aeruginosa was the most commonly isolated pathogen (21 [40%] of the 53 episodes). Patients with GN PJI were older (median age, 68 vs. 59 years; P<.001) and developed infection earlier (median joint age, 74 vs. 109 days; P<.001) than those with GP PJI. Of the 53 episodes of GN PJI, 27 (51%) were treated with debridement, 16 (30%) with 2-stage exchange arthroplasty, and 10 (19%) with resection arthroplasty. Treating GN PJI with debridement was associated with a lower 2-year cumulative probability of success than treating GP PJI with debridement (27% vs. 47% of episodes were successfully treated; P=.002); no difference was found when a PJI was treated with 2-stage exchange or resection arthroplasty. A longer duration of symptoms before treatment with debridement was associated with treatment failure for GN PJI, compared with for GP PJI (median duration of symptoms, 11 vs. 5 days; P=.02). CONCLUSIONS GN PJI represents a substantial proportion of all occurrences of PJI. Debridement alone has a high failure rate and should not be attempted when the duration of symptoms is long. Resection of the prosthesis, with or without subsequent reimplantation, as a result of GN PJI is associated with a favorable outcome rate that is comparable to that associated with PJI due to GP pathogens.

Two-stage revision of infected hip arthroplasty using an antibiotic-loaded spacer: retrospective comparison between short-term and prolonged antibiotic therapy.

OBJECTIVES The optimal duration of systemic antibiotic therapy in patients with prosthetic hip infection (PHI) undergoing staged exchange arthroplasty (SEA) has not been determined. We hypothesized that with an antibiotic-loaded cement spacer (ALCS), in the interim, short-term antibiotic therapy is as effective as a conventional prolonged treatment course. PATIENTS AND METHODS We reviewed 99 patients with PHI who were managed with SEA using an ALCS from February 2002 to October 2005. A standard (4-6 week) antibiotic treatment course was administered in the first 46 patients and a short-term (1 week) therapy was adopted in the subsequent 53 patients. RESULTS Eight patients (four in each group) had persistent infection following the first attempt of surgery and antibiotic treatment; in three of them the infection was cured by additional debridement prior to re-implantation. Forty-two (91%) patients in the long-term group and 47 (89%) patients in the short-term group were free of infection (P = 0.67) at an average follow-up of 43 months (range, 24-60 months). Five (11%) patients developed complications related to prolonged antibiotic therapy. The short-term treatment resulted in a shorter hospital stay (18 versus 43 days, P < 0.001) and a lower direct medical cost (US

In Vitro Activities of Daptomycin-, Vancomycin-, and Teicoplanin-Loaded Polymethylmethacrylate against Methicillin-Susceptible, Methicillin-Resistant, and Vancomycin-Intermediate Strains of Staphylococcus aureus

13 732 versus US

Liquid Gentamicin and Vancomycin in Bone Cement A Potentially More Cost-Effective Regimen

21 756, P < 0.001). CONCLUSIONS Short-term antibiotic therapy was not associated with a higher rate of treatment failure. Given the higher costs and incidence of complications, protracted courses of antibiotic administration may not necessarily be routine practice in patients with PHI undergoing SEA, provided that an ALCS is used.

Hip arthroplasty in patients with cirrhosis of the liver

ABSTRACT The objective of this study was to evaluate the antibacterial effects of polymethylmethacrylate (PMMA) bone cements loaded with daptomycin, vancomycin, and teicoplanin against methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-intermediate Staphylococcus aureus (VISA) strains. Standardized cement specimens made from 40 g PMMA loaded with 1 g (low-dose), 4 g (middle-dose) or 8 g (high-dose) antibiotics were tested for elution characteristics and antibacterial activities. The patterns of release of antibiotics from the cement specimens were evaluated using in vitro broth elution assay with high-performance liquid chromatography. The activities of broth elution fluid against different Staphylococcus aureus strains (MSSA, MRSA, and VISA) were then determined. The antibacterial activities of all the tested antibiotics were maintained after being mixed with PMMA. The cements loaded with higher dosages of antibiotics showed longer elution periods. Regardless of the antibiotic loading dose, the teicoplanin-loaded cements showed better elution efficacy and provided longer inhibitory periods against MSSA, MRSA, and VISA than cements loaded with the same dose of vancomycin or daptomycin. Regarding the choice of antibiotics for cement loading in the treatment of Staphylococcus aureus infection, teicoplanin was superior in terms of antibacterial effects.

Liquid gentamicin in bone cement spacers: in vivo antibiotic release and systemic safety in two-stage revision of infected hip arthroplasty.

This study investigated the use of liquid gentamicin, a much less costly antibiotic (<1/20 the price of tobramycin) with a broad antimicrobial spectrum, alone and in combination with vancomycin in bone cement. Standardized cement specimens loaded with 480 mg of liquid gentamicin, 4 g of powdered vancomycin, or both antibiotics were tested for elution characteristics, bioactivity, compressive strength, and porosity. Vancomycin elution was enhanced by 146% with the addition of gentamicin liquid, and gentamicin elution was enhanced by 45% when combined with vancomycin. Bioassay confirmed the bactericidal activity of the released antibiotics. Adding liquid gentamicin increased porosity, whereas adding vancomycin did not. Compressive strength decreased by 13%, 37%, and 45% in specimens containing vancomycin, liquid gentamicin, and both antibiotics, respectively. Despite inferior mechanical properties, the temporary nature of cement beads and spacers makes the liquid gentamicin-vancomycin mixture a potentially more cost-effective regimen in bone cement to treat musculoskeletal infections.

Periprosthetic fractures of the greater trochanter through osteolytic cysts with uncemented MicroStructured Omnifit prosthesis: Retrospective analyses of 23 fractures in 887 hips after 5–14 years

We retrospectively reviewed 45 hip arthroplasties which were performed over a period of 20 years in 38 patients with cirrhosis of the liver. There was a high perioperative 30-day complication rate (26.7%). Advanced cirrhosis was associated with a higher risk of complications (p = 0.004) as also was increased age, a high level of creatinine, a low level of albumin, a low platelet count, ascites, encephalopathy and an increased operative blood loss. The survival of the prosthesis at five years was 77.8% and infection was a major cause of failure. In view of the high rate of early complications and the limited longevity of the prosthesis, surgeons who perform hip arthroplasty on such patients should counsel them appropriately preoperatively.

Continuous intra-articular infusion of bupivacaine for post-operative pain relief after total hip arthroplasty: A randomized, placebo-controlled, double-blind study

BACKGROUND Powdered antibiotics are widely used in acrylic bone cement. Liquid antibiotics, however, have rarely been employed. This study investigated the application of liquid gentamicin, a much less costly antibiotic with a broad antimicrobial spectrum, in bone cement to treat musculoskeletal infections. METHODS Forty-two patients undergoing two-stage revision hip arthroplasty for periprosthetic infection were managed with an interim cement spacer loaded with liquid gentamicin (480 mg per 20 mL pack of cement monomer) with or without vancomycin (3.0 g per 40 g pack cement polymer). Serum and aliquots of drainage collected after the first-stage surgery; joint fluid obtained at the time of the second-stage surgery were analyzed for antibiotic concentrations and bioactivity. Antibiotic levels in the peripheral blood and renal function were also monitored. RESULTS Antibiotic levels in joint fluid peaked on the first day after implantation of the spacer and then gradually declined during the first week, with levels of gentamicin and vancomycin reached 43.6 mg/L +/- 12.3 mg/L and 485.5 mg/L +/- 103.5 mg/L, respectively. Bioassay confirmed the antimicrobial activity of the released antibiotics. The systemic antibiotic concentrations were below detectable levels in the majority of patients, and no nephrotoxicity was noted. At a mean 87 days after implantation, antibiotic concentrations in joint fluid remained clinically effective (gentamicin, 5.1 mg/L +/- 2.2 mg/L and vancomycin, 21.6 mg/L +/- 8.5 mg/L). CONCLUSIONS Incorporation of liquid gentamicin in bone cement spacers led to effective drug delivery with systemic safety. Substantial health care dollars could be saved by the use of liquid gentamicin in bone cement to treat musculoskeletal infections.

Prosthetic Joint Infection in Patients with Rheumatoid Arthritis: An Outcome Analysis Compared with Controls

Background Periprosthetic fractures of the greater trochanter through osteolytic cysts are rare. The proper treatment and its influence on the prosthetic survival remains unknown. Patients and methods We retrospectively evaluated 887 hips with uncemented MicroStructured Omnifit total hip prostheses at a mean follow-up time of 11 (5–14) years. We found 23 (2.6%) fractures of the greater trochanter through a cystic lesion, occurring 4–11 years postoperatively. Results Nonoperative treatment healed 15 of the 17 fractures that were minimally displaced. At a mean follow-up of 3 (2–5) years after the fracture, 16 had had revision of the components because of excessive wear, loosening, or nonunion. Interpretation We conclude that a periprosthetic fracture of the greater trochanter through an osteolytic lesion is usually stable and heals without treatment. However, it is associated with poor prosthetic survival because of excessive polyethylene wear.