Mel S. Lee

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

Vascularized Iliac Bone-Grafting for Osteonecrosis with Segmental Collapse of the Femoral Head

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.

Soft-tissue injury management and flap reconstruction for mangled lower extremities

BACKGROUND Vascularized iliac bone-grafting has been reported to be successful for patients with osteonecrosis of the femoral head. However, its benefit in patients with segmental collapse of the femoral head has not been determined. The purpose of this study was to analyze the results of vascularized iliac grafting in osteonecrotic femoral heads with segmental collapse. METHODS We retrospectively analyzed thirty-three hips in thirty-two patients in whom an osteonecrotic femoral head with segmental collapse (Association Research Circulation Osseous [ARCO] stage IIIA [<2-mm collapse] or stage IIIB [2 to 4-mm collapse]) had been treated with vascularized iliac bone-grafting between 1994 and 1999. The average age of the patients at the time of surgery was thirty-seven years. Twenty-six patients (twenty-seven hips) overused alcohol, five patients (five hips) had no known risk factor, and one patient (one hip) used corticosteroids for refractory bronchial asthma. Clinical outcomes were evaluated with the Harris hip score. We defined clinical failure as conversion to total hip replacement for any reason and radiographic failure as progressive femoral head collapse or secondary osteoarthritis of the involved hip. RESULTS At the conclusion of the study, only eight (24%) of the thirty-three hips were preserved. The mean survival time for the series as a whole was seventy-four months (95% confidence interval, fifty-four to ninety-five months) after the surgery. Eighteen of the twenty-six ARCO stage-IIIA hips were converted to a total hip replacement, and the mean survival time for the stage-IIIA hips was eighty-five months (95% confidence interval, sixty-one to 108 months). All of the seven ARCO stage-IIIB hips were converted to a total hip replacement, and the mean survival time for the stage-IIIB hips was thirty-five months (95% confidence interval, eleven to fifty-eight months). The mean Harris hip score for the eight hips that still survived at the time of follow-up had improved from 62 points to 80 points. However, all of them had progressive collapse of the femoral head-i.e., radiographic failure-at the time of final follow-up. CONCLUSIONS Vascularized iliac bone-grafting with use of the technique described in this study is not indicated for the treatment of osteonecrotic femoral heads with segmental collapse.

Elevated intraosseous pressure in the intertrochanteric region is associated with poorer results in osteonecrosis of the femoral head treated by multiple drilling

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

SUMMARY The treatment for mangled lower extremities poses a clinical challenge for orthopaedic surgeons. The complexities of soft-tissue injury combined with open fractures and osteomyelitis have frequently resulted in amputation of the lower extremity. The current advances in soft-tissue flap reconstruction techniques have significantly improved the results of limb-salvage attempts. Understanding the reconstructive ladders around the zone of injury, debridement, timing and nuances of techniques regarding skin graft, local and distant flaps and microsurgical reconstruction is necessary to complete limb salvage in a timely and appropriate fashion. Various soft-tissue flap applications have been described, including emergent flow-through flap, acute soft-tissue flap, acute combined soft-tissue and bone flap, pedicle gastrocnemius/soleus flap, pedicle sural artery flap, soft-tissue flap for chronic osteomyelitis, composite osseous-myocutaneous flap for chronic osteomyelitis and free functioning muscle flap for functional reconstruction of mangled lower limbs. Clinical experience of 850 flaps reconstructions for mangled lower limbs in both acute and chronic stages has revealed that adequate application of flap technique was able to achieve quite acceptable results. This article provides a comprehensive review of the soft-tissue injury management and flap reconstruction for mangled lower limbs.

Liquid antibiotics in bone cement: an effective way to improve the efficiency of antibiotic release in antibiotic loaded bone cement.

Multiple drilling is reported to be an effective treatment for osteonecrosis of the head of femur, but its effect on intra-osseous pressure has not been described. We undertook multiple drilling and recorded the intra-osseous pressure in 75 osteonecrotic hips in 60 patients with a mean age of 42 years (19 to 67). At a mean follow-up of 37.1 months (24 to 60), 42 hips (56%) had a clinically successful outcome. The procedure was effective in reducing the mean intra-osseous pressure from 57 mmHg (SD 22) to 16 mmHg (SD 9). Hips with a successful outcome had a mean pressure of 26 mmHg (SD 19). It was less effective in preventing progression of osteonecrosis in hips with considerable involvement and in those with a high intra-osseous pressure in the intertrochanteric region (mean 45 mmHg (SD 25)). This study is not able to answer whether a return of the intra-osseous pressure to normal levels is required for satisfactory healing.