Qais Naziri

Advance pre-operative chlorhexidine reduces the incidence of surgical site infections in knee arthroplasty

Surgical site infections following elective knee arthroplasties occur most commonly as a result of colonisation by the patient’s native skin flora. The purpose of this study was to evaluate the incidence of deep surgical site infections in knee arthroplasty patients who used an advance cutaneous disinfection protocol and who were compared to patients who had peri-operative preparation only. All adult reconstruction surgeons at a single institution were approached to voluntarily provide patients with chlorhexidine gluconate-impregnated cloths and a printed sheet instructing their use the night before and morning of surgery. Records for all knee arthroplasties performed between January 2007 and December 2008 were reviewed to determine the incidence of deep incisional and periprosthetic surgical site infections. Overall, the advance pre-operative protocol was used in 136 of 912 total knee arthroplasties (15%). A lower incidence of surgical site infection was found in patients who used the advance cutaneous preparation protocol as compared to patients who used the in-hospital protocol alone. These findings were maintained when patients were stratified by surgical infection risk category. No surgical site infections occurred in the 136 patients who completed the protocol as compared to 21 infections in 711 procedures (3.0%) performed in patients who did not. Patient-directed skin disinfection using chlorhexidine gluconate-impregnated cloths the evening before, and the morning of, elective knee arthroplasty appeared to effectively reduce the incidence of surgical site infection when compared to patients who underwent in-hospital skin preparation only.

Increased Revision Rates After Total Knee Arthroplasty in Patients Who Smoke

The purpose of this study was to compare the clinical outcomes of total knee arthroplasty in patients who reported a history of tobacco use with those who were nonsmokers. Between 2006 and 2009, there were 131 total knee arthroplasties performed in patients who were smokers and 490 in patients who did not smoke. At a mean follow-up of 47 months (range, 24-79 months), the patients who were smokers had a statistically decreased overall survivorship of 90% (13 revisions) compared with 99% (5 revisions) in the nonsmokers. Surgical complication rates were not significantly different between the 2 groups; however, there was a significant difference in medical complications. Total knee arthroplasty in smokers has a higher risk of negative clinical outcomes compared with nonsmokers.

Risk Factors for Periprosthetic Joint Infection Following Primary Total Hip Arthroplasty: A Case Control Study

The purpose of this study was to identify the specific comorbidities and demographic factors that are independently associated with an increased risk of periprosthetic joint infection (PJI) in total hip arthroplasty (THA) patients. A case-control study design was used to compare 88 patients who underwent unilateral primary THA and developed PJI with 499 unilateral primary THA patients who did not develop PJI. The impact of 18 comorbid conditions and other demographic factors on PJI was examined. Depression, obesity, cardiac arrhythmia, and male gender were found to be independently associated with an increased risk of PJI in THA patients. This information is important to consider when counseling patients on the risks associated with elective THA, and for risk-adjusting publicly reported THA outcomes.

Patellofemoral arthroplasty: 7-year mean follow-up.

Patellofemoral arthroplasty has had renewed interest with the purpose of this study to evaluate its outcomes. Between 2001 and 2006, 43 were performed in 37 patients who had a mean follow-up of 7 years (range, 4-8 years). Patient outcomes were determined using Knee Society objective and function scores, revision rates, and complication rates. The 5-year Kaplan-Meier survivorship was 95%. Knee Society objective scores improved from a mean of 64 points (range, 57-68 points) to 87 points (range, 50-100 points), and functional scores improved from a mean of 48 points (range, 45-50 points) to 82 points (range, 20-100 points). This study shows maintained successful clinical and radiographic results at mean 7-year follow-up for patellofemoral arthroplasty.

Systematic review comparing static and articulating spacers used for revision of infected total knee arthroplasty.

The purpose of this systematic review was to compare the outcomes of static to articulating antibiotic spacers used in two-stage revision total knee arthroplasty. 48 reports with a total of 962 articulating spacers (949 patients) and 707 static spacers (688 patients) with a mean 4 year follow-up were identified for this review. Data on clinical function scores, range-of-motion, complications, and re-infection rates were collected on static and articulating spacers. Both groups had similar improvement in Knee Society Scores (83 versus 82 points), however, the articulating spacer groups had significantly higher range-of-motion (100° versus 92°). There was no difference in the re-infection rates, complication rates, or re-operation rates between the two groups. Currently no specific recommendation can be made about the superiority of one type of spacer over the other.

Bariatric Orthopaedics: Total Knee Arthroplasty in Super-obese Patients (BMI > 50 kg/m2). Survivorship and Complications

BackgroundSome studies have suggested that patients who are super obese (BMI > 50 kg/m2) may have poorer outcomes and more frequent complications when undergoing TKA compared with those who have lower BMI, however, the literature on this is scant.Questions/purposesThe purpose of this study was to compare a group of super-obese patients undergoing TKA with a matched group of patients with BMI less than 30 kg/m2 in terms of (1) implant survivorship, (2) complications, (3) functional parameters, and (4) intraoperative variables (including operative time and estimated blood loss).MethodsOne-hundred one knees in 95 patients (21 men, 74 women) who had a minimum BMI of 50 kg/m2 and who had undergone a primary TKA at one of the four high-volume institutions were compared with a group of patients who had a BMI less than 30 kg/m2 who were matched by age, gender, preoperative clinical scores, and mean followup. End points evaluated by chart review included implant survivorship, medical and surgical complications, functional parameters (The Knee Society outcome scores and ROM), and intraoperative variables at a mean followup of 62 months (range, 36–85 months).ResultsWith the numbers available, there were no differences in aseptic implant survivorship (94% versus 98%, p = 0.28), however, medical and surgical complication rates (14% versus 5%, OR: 3.1, 95% CI=1.07–8.9; p = 0.037) were significantly higher in the super-obese patients compared with the nonobese matching group, respectively. Super-obese patients also achieved lower mean Knee Society functional scores (82 versus 90 points, p = 0.004) and smaller gains in flexion arc ROM (14° versus 21°, p = 0.009); they also lost more blood during surgery and experienced longer surgical anesthesia times compared with the matched group, respectively.ConclusionsWith the numbers available, we could not identify what might have been modest differences in implant survivorship, however, complications were more frequent and functional outcomes were significantly lower in super-obese patients. Other studies similarly have found inferior outcomes in this challenging group of patients. Our data may be considered pilot data for future prospective studies with longer followup.Level of EvidenceLevel III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Dual-mobility bearings: a review of the literature

Dislocation after total hip arthroplasty remains a major problem and hip instability is the most common reason for revision. These complications are costly to both patients and the healthcare system, and efforts to reduce them have had varied degrees of success. Although there are well documented patient and surgical risk factors for dislocation, the typical surgical solutions offered (constrained liners, large femoral heads) have the drawbacks of reduced range-of-motion and high rates of revision. Dual-mobility prostheses (unconstrained tripolar prostheses) are hip design solutions to dislocation that aim to provide a greater stability with an increased range-of-motion, along with potentially reduced wear. The mean overall dislocation rate from multiple combined studies using dual-mobility prostheses was 0.1% for primary total hip arthroplasty and 3.5% for revisions, compared with 2–7% for standard primary total hip arthroplasties and up to 16% for revisions. Dual-mobility prostheses offer a viable option for treating recurrent dislocation as well as for primary and revision arthroplasty.

Minimizing Dynamic Knee Spacer Complications in Infected Revision Arthroplasty

BackgroundDeep infections are devastating complications of TKA often treated with component explantation, intravenous antibiotics, and antibiotic-impregnated cement spacers. Historically, the spacers have been static, which may limit patients’ ROM and ability to walk. Several recent reports describe dynamic spacers, which may allow for improved ROM and make later reimplantation easier. However, because of several dynamic spacer problems noted at our institution, we wanted to assess their associated failures, reinfection rates, and functionality.Questions/purposesWe therefore asked whether there were differences between static and dynamic spacers in (1) reinfection rates, (2) complications directly related to the spacer, and (3) final patient functionality as measured by Knee Society objective scores and ROM.Patients and MethodsWe retrospectively identified 111 patients (115 knees) with 34 dynamic spacers (30%) and 81 static spacers (70%). Reinfection rates, complications requiring additional surgery, and final Knee Society scores and ROM were collected for all patients.ResultsReinfection rates were comparable between groups. In the dynamic spacer cohort, there were four complications; however, these could all be explained by surgical technical errors or patient weightbearing compliance. All patients with failed results eventually underwent successful two-stage exchange arthroplasty. Final Knee Society scores and ROM were also similar between groups.ConclusionsReinfection rates, Knee Society scores, and ROM were comparable between the static and dynamic spacer groups. Meticulous surgical technique and proper patient selection should be used to avoid any complications with any spacers.Level of Evidence Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Outcomes of Cementless Primary THA for Osteonecrosis in HIV-Infected Patients

BACKGROUND Symptomatic osteonecrosis of the joint is a frequent debilitating complication in patients who have been infected with the human immunodeficiency virus (HIV). In earlier reports, outcomes of primary total joint arthroplasty in such patients have been poor due to early failures, high infection rates, and increased complication rates. We report on the clinical and radiographic outcomes of primary total hip arthroplasty (THA) in nonhemophilic, HIV-infected patients as compared with the outcomes in a cohort of osteonecrosis patients who did not have this disease. METHODS Thirty-four HIV-infected patients (forty-four hips) who underwent primary THA for the treatment of osteonecrosis during the period of 2001 through 2008 were compared with a control cohort of seventy patients (seventy-eight hips) who also underwent THA for the treatment of osteonecrosis but did not have HIV or other high-risk factors for revision. The patients in the HIV study group (eleven women and twenty-three men) had a mean age of forty-eight years (range, thirty-four to eighty years) and were followed for a mean of seven years (range, four to eleven years). Evaluated outcomes included implant survivorship, Harris hip score, infection rate, activity score, postoperative Short-Form 36 (SF-36) health survey score, and radiographic outcome. RESULTS Kaplan-Meier survival analysis demonstrated no significant difference in aseptic implant survivorship between the HIV and comparison cohorts at the five-year (100% vs. 98%, respectively) and ten-year (95% vs. 96.5%, respectively) follow-up times. In addition, at the time of final follow-up, the mean postoperative Harris hip scores (85 points in the HIV group vs. 87 points in the comparison group), activity scores (5.7 points in the HIV group vs. 6.1 points in the comparison group), and SF-36 physical (43 points in the HIV group versus 46 points in the comparison group) and mental component summary scores (54 points in the HIV group versus 57 points in the comparison group) were statistically similar between the two cohorts. There were two late infections in the HIV cohort as compared with none in the comparison cohort. CONCLUSIONS Our results demonstrated excellent implant survivorship, clinical and radiographic outcomes, and minimal complications at the time of midterm follow-up in the HIV-infected patient group. We believe that the outcomes associated with primary THA are improving in this patient population as a result of better medical management; however, late infections are potential complications.

Hip osteonecrosis: does prior hip surgery alter outcomes compared to an initial primary total hip arthroplasty?

The purpose of this study was to assess the clinical and radiographic outcomes of total hip arthroplasty (THA) in patients who had osteonecrosis to see if prior hip preserving surgery affected outcomes. Implant survivorship, Harris hip scores, and radiographic outcomes were compared between 87 patients (92 hips) who had undergone prior hip preserving procedures and 105 patients (121 hips) who had only undergone THA. Patients were also sub-stratified into low- and high-risk groups for osteonecrosis. At a mean follow-up of 75 months, there were no significant differences in survivorship, clinical, and radiographic outcomes among the cohorts. Higher revision rates were associated with patients who were in the high-risk group. The authors believe that hip joint preserving procedures may not adversely affect the outcomes of later THA in patients with osteonecrosis.