The Impact of Patellar Resurfacing in Two-Stage Revision of the Infected Total Knee Arthroplasty

Evidence for optimal management of the patellofemoral joint in revision surgery for the infected TKA is limited. We reviewed 69 infected TKAs undergoing two-stage revision. Fifty four patellae were resurfaced, 11 had patelloplasty performed, two were augmented with trabecular metal, one had impaction grafting, and one knee underwent patellectomy. Average follow-up was 4.5 years. The patients that received patellar resurfacing at re-implantation experienced statistically significant improvements in KSS pain score, functional KSS, and patellar score (P < 0.03). One further patient treated with impaction grafting improved significantly in terms of pain and function. Patients treated with patelloplasty, trabecular metal augmentation, or patellectomy did not have significant improvements in clinical or functional outcome. Patient age, use of dynamic vs. static spacer, use of extensor mechanism release, and differences in Charlson index did not seem to statistically affect outcome. We recommend that every effort should be made to minimize patellar bone loss in first stage resection, as inability to resurface the patella at time of reimplantation may adversely affect patient outcome.     

Management of Chronically Infected Total Knee Arthroplasty With Severe Bone Loss Using Static Spacers With Intramedullary Rods

BackgroundTwo-stage revision with static antibiotic spacers is the preferred treatment for chronically infected total knee arthroplasty (TKA) associated with severe bone loss. Intramedullary rods to reinforce static spacers have been described. On those, however, bacterial colonization may occur and hamper infection control. This study reports the microbiological findings on the spacer rods and the treatment outcome among these patients.MethodsWe reviewed 97 infected TKA with extensive bone loss treated with antibiotic-loaded cement spacers reinforced with intramedullary rods. Mean interim period with the spacer in situ was 9 weeks (range: 6-24 weeks). Intraoperative cultures and sonicated spacer rods were analyzed. Mean follow-up after TKA reimplantation was 41 months (range: 27-56 months). Treatment success was defined using the modified Delphi consensus criteria.ResultsTwenty-two patients (23%) had treatment failure, including 3 reinfections caused by the same organism, 9 reinfections caused by a different organism, 9 patients required interim spacer exchange, and 1 patient died in the early postoperative course. Sonication cultures of the spacer rods were positive in 2 cases (2%), and none of them failed. Host and limb status was significantly worse in patients who sustained reinfection. At the latest follow-up, all patients had a TKA in place, and 2 patients received chronic antibiotic suppression.ConclusionTwo-stage revision with the use of intramedullary rods is a safe and efficient treatment for chronically infected TKA with severe bone loss. Most reinfections grew different organisms compared with initial infection. Compromised hosts and extremities may be subjected to chronic antibiotic suppression.     

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.     

The Fate and Relevance of the Patella in Two-Stage Revision Total Knee Arthroplasty for Periprosthetic Joint Infection

BackgroundIt remains unclear whether reimplantation of a patellar component during a two-stage revision for periprosthetic total knee arthroplasty infection (PJI) affects patient reported outcome measures (PROMs) or implant survivorship. The purpose of this study was to evaluate whether patellar resurfacing during reimplantation confers a functional benefit or increases implant survivorship after two-stage treatment for PJI.MethodsTwo-stage revisions for knee PJI performed by three surgeons at a single tertiary care center were reviewed retrospectively. All original patellar components and cement were removed during resection and the patella was resurfaced whenever feasible during reimplantation. PROMs, implant survivorship, and radiographic measurements (patellar tilt and displacement) were compared between knees reimplanted with a patellar component versus those without a patellar component.ResultsA total of 103 patients met the inclusion criteria. Forty-three patients (41.7%) underwent reimplantation with, and 60 patients (58.3%) without a patellar component. At a mean follow-up of 33.5 months, there were no significant differences in patient demographics or PROMs between groups (P ≥ .156). No significant differences were found in the estimated Kaplan-Meier all-cause, aseptic, or septic survivorship between groups (P ≥ .342) at a maximum of 75 months follow-up. There was no significant difference in the change (pre-resection to post-reimplant) of patellar tilt (P = .504) or displacement (P = .097) between the groups.ConclusionPatellar resurfacing during knee reimplantation does not appear to meaningfully impact postoperative PROMs or survivorship. Given the risk of potential extensor mechanism complications with patellar resurfacing, surgeons may choose to leave the patella without an implant during total knee reimplantation and expect similar clinical outcomes.Level of EvidenceLevel III.     

Removed Antibiotic-Impregnated Cement Spacers in Two-Stage Revision Joint Arthroplasty Do Not Show Biofilm Formation In Vivo

Use of antibiotic-impregnated spacers is common in the two-stage approach to treatment of periprosthetic joint infection despite the lack of information regarding in vivo performance of these implants. Antibiotic elution levels likely often fall below the minimal inhibitory concentration need to inhibit bacterial growth, raising concern that the spacers themselves may provide a potential attachment site for biofilm formation. Advanced microscopy was used in this study to evaluate the surface characteristics of antibiotic-eluting spacers collected at the time of prosthesis reimplantation from 6 patients undergoing two-stage treatment for an infected total joint arthroplasty. Scanning electron microscopy and confocal scanning microscopy of the removed spacers revealed modest fibrous matrix formation and inflammatory cells with no biofilm or bacteria detected. This study supports the continued use of antibiotic spacers in the treatment of periprosthetic joint infection.     

Vancomycin-Gentamicin Prefabricated Spacers in 2-Stage Revision Arthroplasty for Chronic Hip and Knee Periprosthetic Joint Infection: Insights Into Reimplantation Microbiology and Outcomes

BackgroundSecond-stage positive cultures in 2-stage revision arthroplasty are a matter of concern, as their influence in outcomes is not clearly defined. We sought to study reimplantation microbiology when using vancomycin-gentamicin prefabricated cement spacers in hip and knee periprosthetic joint infection. The associations of second-stage positive cultures with treatment failures and patient-associated factors were analyzed.MethodsWe conducted a retrospective cohort study, examining patients managed with 2-stage revision arthroplasty due to knee or hip chronic periprosthetic joint infection between 2010 and 2017. Prefabricated vancomycin-gentamicin cement spacers were used during the spacer stage. Intraoperative microbiological culture results after the first and second stages were evaluated. The primary end point was infection eradication or relapse.ResultsA total of 108 cases were included (61 hips and 47 knees). And 22.2% of patients had ≥1 second-stage positive culture, while 9.3% had ≥2 positive samples. Overall success, at an average follow-up of 46.4 months, was 77.8%. Treatment failure was higher among cases with positive cultures (15.5% vs 45.8%, P < .01) regardless of the number of positive samples. Diabetes was identified as a risk factor for second-stage positive cultures (P = .03); use of cement loaded with extra antibiotics for spacer fixation showed a protective effect (P < .01).ConclusionSecond-stage positive cultures were related to a higher failure rate when using vancomycin-gentamicin cement spacers. Diabetes increased the likelihood of second-stage positive cultures. The use of extra-antibiotic-loaded cement for spacer fixation during the first stage showed a protective effect.     

Outcome and Predictors of Septic Failure Following Total Joint Arthroplasty for Prior Septic Arthritis of Hip and Knee Joint

BackgroundArthroplasty patients with prior septic arthritis are at a high risk of developing periprosthetic joint infection (PJI). The aims of this study are to investigate the outcome and predictors of septic failure following total joint arthroplasty (TJA) for prior septic arthritis. In addition, the optimal timing of TJA is also discussed.MethodsA retrospective review of 105 TJA patients with prior septic arthritis between January 2000 and December 2019 was performed. Patient-specific and surgery-related factors, organism profiles, and other relevant variables were recorded.ResultsAt a mean follow-up of 10.3 years, the PJI rate was 16.2%. The adjusted Cox proportional hazards model showed that male gender (HR, 9.95; P < .01), end-stage renal disease (HR, 37.34; P < .01), debridement surgery ≥3 times (HR,4.75; P = .04) and polymicrobial infection in primary septic arthritis (HR, 10.02; P = .02) were independent risk factors for PJI. Neither the types of initial debridement, nor one-stage vs two-stage arthroplasty was related to the risk of PJI. While delaying the timing of TJA did not correlate with a reduction of PJI rate, there was a higher risk of PJI re-infection by the same microorganisms isolated in prior septic arthritis if TJA was performed within 6 months after septic arthritis.ConclusionsOur study demonstrated that male gender, end-stage renal disease (ESRD), multiple debridement surgeries and polymicrobial septic arthritis predisposed septic failure of TJA following prior septic arthritis. Surgeons should counsel patients with the potential complications, and be cognizant about the risk factors pertaining to septic failure when considering TJA.     

Randomized Trial of Static and Articulating Spacers for Treatment of the Infected Total Hip Arthroplasty

BackgroundThe purpose of this randomized clinical trial is to compare perioperative and postoperative variables between static and articulating spacers for the treatment of chronic periprosthetic joint infection (PJI) complicating total hip arthroplasty (THA).MethodsFifty-two patients undergoing resection arthroplasty as part of a 2-stage exchange for PJI at 3 centers were randomized to either a static (n = 23) or articulating spacer (n = 29). The primary endpoint was operative time of the second-stage reimplantation and power analysis determined that 22 patients per cohort were necessary to detect a 20-minute difference. Seven patients were lost to follow-up, 4 were never reimplanted, and one died before discharge after reimplantation. Forty patients were followed for a mean 3.2 years (range 2.0-7.1).ResultsThere were no differences in operative time at second-stage reimplantation (143 minutes static vs 145 minutes articulating, P = .499). Length of hospital stay was longer in the static cohort after stage 1 (8.6 vs 5.4 days, P = .006) and stage 2 (6.3 vs 3.6 days, P < .001). Although it did not reach statistical significance with the numbers available for study, nearly twice as many patients in the static cohort were discharged to an extended care facility after stage 1 (65% vs 30%, P = .056).ConclusionThis randomized trial demonstrated that the outcomes of static and articulating spacers are similar in the treatment of THA PJI undergoing 2-stage exchange arthroplasty. The significantly longer length of hospital stay associated with the use of static spacers may have important economic implications for the health care system.     

The Influence of Spacer Design on the Rate of Complications in Two-Stage Revision Hip Arthroplasty

BackgroundAntibiotic cement spacers are used during 2-stage revision total hip arthroplasty for prosthetic joint infection. Complications including dislocation and periprosthetic fracture have been reported but a large cohort comparing spacer design features is lacking. We aimed to determine if spacer design is associated with perioperative complications.MethodsWe performed a retrospective review of antibiotic cement spacers implanted between 2004 and 2014. Radiographic assessment included leg length, offset, and bone loss (Paprosky classification). Clinical outcomes included dislocation, periprosthetic fracture, spacer fracture, infection cure, and overall reoperation rate. Univariate analysis, Student’s t-test, chi-squared test, or Kruskal-Wallis test was employed (P < .05).ResultsOne hundred eighty-five patients were treated: 42% were female and mean age was 64 years (range 24-93, standard deviation 13.6). Spacer types were (1) molded (53%), (2) antibiotic-coated prosthesis (30%), (3) handmade (12%); and (4) prefabricated (4%). Cemented acetabular liners were used in 3% (6/185). There was no loss to follow-up during the interstage period. Spacer complications occurred in 26% (48/185). Dislocation occurred in 9% (17/185) and was associated with reduced femoral offset of >5 mm (P = .033) and increased bone loss (P = .01). Spacer fracture occurred in 8% (14/185); 12% (12/97) molded versus 8% (2/23) handmade (P = .02). Periprosthetic femur fracture was associated with increased offset >5 mm (P = .01) and extended trochanteric osteotomy (P = .001).ConclusionDuring 2-stage total hip arthroplasty, antibiotic-loaded cement spacers had an overall complication rate of 26%. Spacer design, acetabular and femoral bone loss, and offset restoration were significantly associated with perioperative complications. We recommend the optimization of antibiotic-loaded cement spacer placement to minimize potential complications by focusing on restoration of leg-length and offset, ensuring adequate femoral fixation and paying attention to selection of an appropriate head/neck ratio.     

Two-Stage Revision Total Hip Arthroplasty With a Specific Articulating Antibiotic Spacer Design: Reliable Periprosthetic Joint Infection Eradication and Functional Improvement

Background

Two-stage revision utilizing spacers loaded with high-dose antibiotic cement prior to reimplantation remains the gold standard for treatment of periprosthetic joint infections (PJI) in total hip arthroplasty (THA) in North America, but there is a paucity of data on mid-term outcomes. We sought to analyze the survivorship free of infection, clinical outcomes, and complications of a specific articulating spacer utilized during 2-stage revision.

Two-Stage Revision Total Hip Arthroplasty Without Spacer Placement: A Viable Option to Manage Infection in Patients With Severe Bone Loss or Abductor Deficiency

BackgroundHigh rates of spacer-related complications in two-stage exchange total hip arthroplasty (THA) have been reported. Patients with advanced bone defects and abductor deficiency may benefit from a nonspacer two-stage revision. This study reports on the clinical course of a contemporary two-stage exchange for periprosthetic hip infection without spacer insertion.MethodsWe reviewed 141 infected THAs with extensive bone loss or abductor damage who underwent two-stage exchange without spacer placement. The mean duration from resection arthroplasty to reimplantation was 9 weeks (2-29). Clinical outcomes included interim revision, reinfection, and aseptic revision rates. Restoration of leg-length and offset was assessed radiographically. Modified Harris hip scores were calculated. Mean follow-up was 5 years (3-7). Treatment success was defined using the modified Delphi consensus criteria.ResultsThirty-four patients (24%) had treatment failure, including 13 reinfections, 16 interim redebridements for persistent infection, 2 antibiotic suppressive therapies, and 3 prosthetic joint infection–related deaths. Aseptic rerevision after reimplantation was necessary in 14 patients (10%). Dislocation accounted for most aseptic complications, with 20 dislocations occurring in 15 patients (11%). Leg-length and offset were restored to preoperative measures. Mean modified Harris hip scores significantly improved from 35 points to 67 points.ConclusionA nonspacer two-stage exchange is a viable option for managing chronically infected THA with severe bone loss or abductor deficiency, showing comparable rates of interim revision and recurrence of infection. Cementless reimplantation demonstrates good midterm survivorship with comparable functional outcomes and leg-length restoration. However, dislocation continues to be a major concern.     

Time Required for Planned and Unplanned Episodes of Care in Septic Two-Stage Revision Hip and Knee Arthroplasty

BackgroundSeptic revision total hip (rTHA) and knee (rTKA) arthroplasty requires more effort but is reimbursed less than primary procedures per minute of intraoperative time. This study quantified planned and unplanned work performed by the surgical team for septic 2-stage revision surgeries during the entire episode-of-care “reimbursement window” and compared that time to allowable reimbursement amounts.MethodsBetween October 2010 and December 2020 all unilateral septic 2-stage rTHA and rTKA procedures performed by a single surgeon at a single institution were retrospectively reviewed. Time dedicated to planned work was calculated over each episode of care, from surgery scheduling to 90 days postoperatively. Impromptu patient inquiries and treatments after discharge, but within the episode of care, involving the surgeon/surgeon team constituted unplanned work. Planned and unplanned work minutes were summed and divided by the number of patients reviewed to obtain average minutes of work per patient.ResultsSixty-eight hips and 64 knees were included. For 2-stage rTHA and rTKA the average time per patient for planned care was 1728 and 1716 minutes and for unplanned care was 339 and 237 minutes. Compared to the Centers for Medicare and Medicaid Services’ allowable reimbursement times, an additional 799 and 887 minutes of uncompensated time was required to care for 2-stage rTHA and rTKA patients.ConclusionTwo-stage revision procedures are substantially more complex than primary procedures. Financially disincentivizing surgeons to care for these patients reduces access to care when high-quality care is most needed. These findings support increasing the allowable times for 2-stage septic revision cases.     

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.     

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.     

Reduced Infection Rate After Aseptic Revision Total Knee Arthroplasty With Extended Oral Antibiotic Protocol

BackgroundThe optimal postoperative antibiotic duration has not been determined for aseptic revision total knee arthroplasty (R-TKA) where the risk of periprosthetic joint infection (PJI) is 3%-7.5%. This study compared PJI rates in aseptic R-TKA performed with extended oral antibiotic prophylaxis (EOAP) to published rates.MethodsAseptic R-TKAs consecutively performed between 2013 and 2017 at a tertiary care referral center in the American Midwest were retrospectively reviewed. All patients were administered intravenous antibiotics while hospitalized and discharged on 7-day oral antibiotic prophylaxis. Infection rates and antibiotic-related complications were assessed.ResultsSixty-seven percent of the 176 analysis patients were female, with an average age of 64 years and body mass index of 35 kg/m². Instability and aseptic loosening comprised 86% of revision diagnoses. Overall, 87.5% of intraoperative cultures were negative, and the remainder were single positive cultures considered contaminants. PJI rates were 0% at 90 days, 1.8% (95% confidence interval 0.4%-5.3%) at 1 year, and 2.2% (95% confidence interval 0.6%-5.7%) at mean follow-up of approximately 3 years (range, 7-65 months).ConclusionEOAP after aseptic R-TKA resulted in a PJI rate equivalent to primary TKA, representing a 2- to-4-fold decrease compared with published aseptic R-TKA infection rates. Further study on the benefits and costs of EOAP after aseptic R-TKA is encouraged.     

High Rate of Intramedullary Canal Culture Positivity in Total Knee Arthroplasty Resection for Prosthetic Joint Infection

BackgroundPeriprosthetic infection is a devastating complication following total knee arthroplasty. A 2-stage protocol often includes an interim antibiotic spacer with intramedullary (IM) dowels. However, the necessity of IM dowels has recently been challenged. Specifically, the data supporting bacterial colonization of the IM canal are limited and controversial. The purpose of this study was to identify the rate of positive IM cultures during resection arthroplasty in periprosthetic knee infection.MethodsA total of 66 IM diaphyseal cultures were taken during resection arthroplasty from 34 patients diagnosed with periprosthetic knee infection. These IM cultures were taken from the femoral and tibial canals using separate sterile instruments. All patients had infected primary total knee arthroplasty implants at the time of resection.ResultsThirty one percent (n = 21) of IM canal cultures in this study were positive from either the tibial or the femoral diaphysis at the time of resection arthroplasty. There were 18 of 21 (86%) of the positive IM canal cultures with concordant intraoperative joint cultures where the IM cultures matched the intraarticular cultures.ConclusionWith a 31% positive IM canal culture rate, this study confirms the logic of using IM dowels with an antibiotic spacer to treat periprosthetic knee infection. Since the failure of a 2-stage reimplantation is catastrophic, any attempt to provide additional local antibiotic delivery seems warranted. Since nearly one-third of our patients had positive IM cultures, this simple addition to an antibiotic spacer has the potential to improve 2-stage results. Claims supporting the elimination of IM dowels during resection arthroplasty seem ill-advised.     

Hypoalbuminemia Predicts Failure of Two-Stage Exchange for Chronic Periprosthetic Joint Infection of the Hip and Knee

BackgroundNutritionally compromized patients, with preoperative serum albumin (SAB) < 3.5g/dL, are at higher risk for periprosthetic joint infection (PJI) in total joint arthroplasty. The relationship between nutritional and PJI treatment success is unknown. The purpose of this study was to examine the relationship between preresection nutrition and success after first-stage resection in planned two-stage exchange for PJI.MethodsA retrospective review was performed on 418 patients who had first-stage resection of a planned two-stage exchange for chronic hip or knee PJI between 2014 and 2018. A total of 157 patients (58 hips and 99 knees) were included who completed first stage, had available preop SAB and had a 2-year follow-up. Failure was defined as persistent infection or repeat surgery for infection after resection. Demographic and surgical data were abstracted and analyzed.ResultsAmong knee patients with preop SAB >3.5 g/dL, the failure rate was 32% (15 of 47) versus a 48% (25 of 40) failure rate when SAB <3.5 g/dL (P = .10). Similarly, the failure rate among hip patients with preop SAB >3.5 g/dL versus 12.5% (3 of 24) versus 44% (15 of 34) for hip patients with SAB <3.5 g/dL (P = .01). Multivariable regression results indicated that patients with SAB< 3.5 g/dL (P = .0143) and Musculoskeletal Infection Society host type C (P = .0316) were at an increased risk of failure.ConclusionLow preoperative SAB and Musculoskeletal Infection Societyhost type-C are independent risk factors for failure following first-stage resection in planned two-stage exchange for PJI. Efforts to nutritionally optimize PJI patients, when possible, may improve the outcome of two-stage exchange.     

Retained Antibiotic Spacers After Total Hip and Knee Arthroplasty Resections: High Complication Rates

Background

Prolonged retention of an antibiotic spacer is occasionally chosen during treatment of periprosthetic joint infections after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of our study was to evaluate the outcome of extended spacer retention.

Selected Heat-Sensitive Antibiotics Are Not Inactivated During Polymethylmethacrylate Curing and Can Be Used in Cement Spacers for Periprosthetic Joint Infection

Background

Antibiotic use in polymethylmethacrylate (PMMA) spacers has historically been limited to those which are “heat-stable” and thus retain their antimicrobial properties after exposure to the high temperatures which occur during PMMA curing.

Survivorship of Extensor Mechanism Allograft Reconstruction After Total Knee Arthroplasty

Background

Extensor mechanism disruption remains a devastating complication after total knee arthroplasty. The purpose of this study is to describe the outcomes of extensor mechanism allograft (EMA) reconstruction in a large single-center case series.