Ho-Rim Choi

Periprosthetic Joint Infection with Negative Culture Results: Clinical Characteristics and Treatment Outcome

Negative culture result is frequently encountered in periprosthetic joint infection, but its clinical feature has not been well studied. In this study, clinical characteristics and treatment outcome were compared in two patient groups: (1) 40 periprosthetic joint infections with negative culture results (culture-negative group) and (2) 135 patients with positive culture results (culture-positive group). In comparison of two groups, the culture-negative group showed significantly higher incidence of prior antibiotic use (p=0.005), higher incidence of prior resection surgery (p<0.001) and lower ESR (p=0.02) than the culture-positive group. The success rate of infection control was higher in the culture-negative group (p=0.006), which suggests that culture negativity may not necessarily be a negative prognostic factor for periprosthetic joint infection.

Are prosthetic spacers safe to use in 2-stage treatment for infected total knee arthroplasty?

This retrospective study compares treatment results of infected total knee arthroplasty with 2-stage exchange technique using 14 articulating spacers using metallic and polyethylene components (prosthetic group) and 33 static all-cement spacer (static group). For the prosthetic and static groups, treatment success rate was 71% and 67% at 58 months of follow-up, respectively, and not significantly different. The prosthetic group required less frequent extensile surgical approaches at the second-stage reimplantation. Range of motion was significantly improved in both groups, but there was no difference at latest follow-up between the groups. Of 14 in the prosthetic group, 4 (28%) did not undergo second-stage procedure. Antibiotic spacers consisting of prosthetic components can be a safe and effective treatment option for 2-stage revision total knee arthroplasty with equivalent infection control rates.

Comparison of One-Stage Revision With Antibiotic Cement Versus Two-Stage Revision Results for Infected Total Hip Arthroplasty

Eighty three patients of infected total hip arthroplasty (THA) treated by implant removal and staged revision were retrospectively analyzed. Clinical characteristics and treatment outcomes were compared between three groups: 17 one-stage revisions (one-stage group), 44 two-stage revisions with second stage reimplantation (two-stage reimplanted group), and 22 planned two-stage but no reimplantation (two-stage non-reimplanted group). The rate of infection control was 82% (14/17) in the one-stage group, 75% (33/44) in the two-stage reimplanted group, and 68% (15/22) in the two-stage non-reimplanted group (P=0.60). The mean of latest Harris hip score was 77, 60, and 58 (P=0.14), and the UCLA activity score was 4.0, 4.2, and 3.6 (P=0.74) for each group, respectively. Results of this study suggest that one-stage revision arthroplasty can be a treatment option in selected cases of infected THA with a satisfactory infection control rate and functional outcomes comparable to those of two-stage revision.

Retention treatment after periprosthetic total hip arthroplasty infection

PurposeThe purpose of this study was to compare infection control rates between implant retention and two-stage revision and assess the effectiveness of retention treatment in THA.MethodsTwenty-eight debridements with implant retention (retention group) and 65 staged revisions (removal group) were retrospectively analysed and risk factors that can contribute to failure of infection control were explored.ResultsFor the retention and removal groups, infection control rates were 50% and 78% after initial treatment, and 68% and 82% at latest follow-up, respectively. There were no significant differences in the number of additional operative procedures, total length of hospital stay, and duration of treatment between groups. Infection of revision THA, polybacterial and S. aureus infection were identified as risk factors for infection control.ConclusionsRetention treatment can be considered an initial treatment option in selected cases of primary THA, with a single organism, non-S. aureus infection with 50% chance of infection control and no disadvantages in terms of additional procedure, hospital stay, and treatment duration.

The Fate of Unplanned Retention of Prosthetic Articulating Spacers for Infected Total Hip and Total Knee Arthroplasty

Eighteen patients with periprosthetic joint infection (11 hips and 7 knees) treated by prosthetic articulating spacers retained their spacers and were followed up at an average of 43.8 months(range, 13-78 months). Fifteen patients maintained well-functioning spacers for an average of 42.7 months, of which 4 patients died with the spacers in situ at an average of 48.7 months. The mean Harris Hip Score and Knee Society knee and function scores of survivors were 92, 92, 88, respectively. Spacers were revised in 3 patients because of recurrent infection (n = 1) at 24 months and mechanical loosening (n = 2) at 74 and 50 months. Findings of this study suggest that a proportion of patients with unplanned retention of prosthetic spacers appear to function well up to 6 years without necessarily requiring further surgical intervention.

Mortality After Septic Versus Aseptic Revision Total Hip Arthroplasty: A Matched-Cohort Study

Mortality rates after revision total hip arthroplasty (THA) for periprosthetic sepsis were investigated in 93 patients and compared to 93 patients, matched for age, gender, year of surgery, who underwent revision for aseptic failures. The mortality rate was 33% (31/93) in the septic group and 22% (20/93) in the aseptic group at 5 and 6 year follow-up, respectively (P=0.10). Patients in the septic group died on average 6 years earlier (74 versus 80 yrs; P<0.05) than those in the aseptic group. Charlson Comorbidity Index (CCI) was an independent predictor of mortality among the both groups (P<0.05), while age (P<0.01) was a predictor of mortality only in the aseptic group. While revision THA for sepsis alone did not predict increased mortality, a 33% mortality rate at five years in patients with an average age of 66 years and earlier death by 6 years compared to aseptic revisions is alarming.

Mortality Following Revision Total Knee Arthroplasty: A Matched Cohort Study of Septic versus Aseptic Revisions

We report the medium-term mortality after septic versus aseptic revision total knee arthroplasty (TKA) and factors that can contribute to mortality in revision TKA. Mortality rates of 88 patients undergoing septic revision (septic group) were compared with age- and year of surgery-matched 88 patients of aseptic revision (aseptic group). The overall mortality after revision TKA was 10.7% at a median of 4 years of follow-up (range, 2-7 years). However, the mortality after septic revision (18%, 16/88) was six times higher than that of aseptic revision (3%, 3/88) (P = 0.003). Infections with Staphylococcus aureus and/or methicillin resistance was not associated with higher mortality rates. Multivariate analysis indicated that increased age (P < 0.001), higher ASA class (P = 0.002), and septic revision (P < 0.001) were identified as independent predictors of increased mortality after revision TKA.

Is There a Benefit to Modularity in ‘Simpler’ Femoral Revisions?

BackgroundModular revision femoral components allow the surgeon to make more precise intraoperative adjustments in anteversion and sizing, which may afford lower dislocation rates and improved osseointegration, but may not offer distinct advantages when compared with less expensive monoblock revision stems.Questions/purposesWe compared modular and monoblock femoral components for revision of Paprosky Type I to IIIA femoral defects to determine (1) survivorship of the stems; and (2) complications denoted as intraoperative fracture, dislocation, or failure of osseointegration.MethodsBetween 2004 and 2010, participating surgeons at three centers revised 416 total hip arthroplasties (THAs) with Paprosky Type I to IIIA femoral defects. Of those with minimum 2-year followup (343 THAs, mean followup 51 ± 13 months), 150 (44%) were treated with modular stems and 193 (56%) were treated with monoblock, cylindrical, fully porous-coated stems. During this time, modular stems were generally chosen when there was remodeling of the proximal femur into retroversion and/or larger canal diameters (usually > 18 mm). A total of 27 patients died (6%) with stems intact before 2 years, 46 THAs (13%) were lost to followup before 2 years for reasons other than death, and there was no differential loss to followup between the study groups. The modular stems included 101 with a cylindrical distal geometry (67%) and 49 with a tapered geometry (33%). Mean age (64 versus 68 years), percentage of women (53% versus 47%), and body mass index (31 versus 30 kg/m2) were not different between the two cohorts, whereas there was trend toward a slightly greater case complexity in the modular group (55% versus 65% Type 3a femoral defects, p = 0.06). Kaplan-Meier survivorship was calculated for the endpoint of aseptic revision. Proportions of complications in each cohort (dislocation, intraoperative fracture, and failure of osseointegration) were compared.ResultsFemoral component rerevision for any reason (including infection) was greater (OR, 2.01; 95% CI, 1.63–2.57; p = 0.03) in the monoblock group (27 of 193 [14%]) compared with the modular cohort (10 of 150 [7%]). Femoral component survival free from aseptic rerevision was greater in the modular group with 91% survival (95% CI, 89%–95%) at 9 years compared with 86% survival (95% CI, 83%–88%) for the monoblock group in the same timeframe. There was no difference in the proportion of mechanically relevant aseptic complications (30 of 193 [16%] in the monoblock group versus 34 of 150 [23%] in the modular group, p = 0.10; OR, 1.47; 95% CI, 0.86–2.53). There were more intraoperative fractures in the modular group (17 of 150 [11%] versus nine of 193 [5%]; OR, 2.2; 95% CI, 1.68–2.73; p = 0.02). There were no differences in the proportions of dislocation (13 of 193 [7%] monoblock versus 14 of 150 [9%] modular; OR, 0.96; 95% CI, 0.67–1.16; p = 0.48) or failure of osseointegration (eight of 193 [4%] monoblock versus three of 150 [2%] modular; OR, 1.92; 95% CI, 0.88–2.84; p = 0.19) between the two groups with the number of hips available for study.ConclusionsAlthough rerevisions were less common in patients treated with modular stems, aseptic complications such as intraoperative fractures were more common in that group, and the sample was too small to evaluate corrosion-related or fatigue concerns associated with modularity. We cannot therefore conclude from this that one design is superior to the other. Larger studies and pooled analyses will need to be performed to answer this question, but we believe modularity should be avoided in more straightforward cases if possible.Level of EvidenceLevel III, therapeutic study.

The Outcome of Sequential Repeated Tibial Tubercle Osteotomy Performed in 2-Stage Revision Arthroplasty for Infected Total Knee Arthroplasty

Thirteen patients with infected total knee arthroplasty treated by 2-stage revision requiring tibial tubercle osteotomy in both stages for extensile exposure were retrospectively analyzed. The preoperative mean range of knee motion improved from 60° (range, 30°-90°) to 94° (range, 70°-120°) at latest follow-up. The Knee Society knee scores and function scores were 39 and 18 preoperatively and 78 and 67 at latest follow-up, respectively. Although proximal migration occurred in 3 cases and a partial proximal avulsion fracture of the osteotomy segment occurred in 1 case after the second-stage reimplantation, radiographic bony union was observed in all cases. Sequential repeated tibial tubercle osteotomy can be a useful extensile surgical approach in staged revision for infected total knee arthroplasty with satisfactory clinical and radiographic outcomes.

Transfer of patient care during two-stage exchange for periprosthetic joint infection leads to inferior outcomes.

The two-stage exchange algorithm is the gold standard for managing chronic periprosthetic joint infection (PJI); this study evaluated the impact of having the stages performed at different institutions. Patients with a chronically infected total joint arthroplasty (hip or knee) with initial resection at an outside hospital and subsequent care at our institution (transferred group) were identified then matched with a similar cohort that received both stages at our institution (continuous group). Eighteen patients (transferred group) were compared to 36 matched controls. There were significantly lower rates of successful reimplantation and retention, longer duration of treatment and more procedures in the transferred group compared to the continuous group. Patients transferred during their care for chronic PJI underwent more surgeries, longer treatment times, and less favorable outcomes.