Migration Patterns for Revision Total Hip Arthroplasty in the United States as Reported in the American Joint Replacement Registry

BackgroundRevision total hip arthroplasty (revTHA) is associated with higher rates of complications and greater costs than primary procedures. The aim of this study is to evaluate the effect of hospital size, teaching status, and indication for revTHA, on migration patterns in patients older than 65 years old.MethodsAll THAs and revTHAs reported to the American Joint Replacement Registry from 2012 to 2018 were included and merged with the Centers for Medicare and Medicaid Services database. Migration rate was defined as a patient’s THA and revTHA procedures that were performed at separate institutions by different surgeons. Migratory patterns were recorded based on hospital size, teaching status, and indication for revTHA. Analyses were performed by statisticians.ResultsThe number of linked procedures included was 11,906. Migration rates in revTHA due to infection were higher for small hospitals than large hospitals (46.6% vs 28.6%, P < .0001). Migration rates were higher comparing non-teaching with teaching hospitals (55% vs 34%, P < .0001). This difference was significant for periprosthetic fractures (70.6% vs 37.2%, P = .005), instability (56.5% vs 35.5%, P = .04), and mechanical complications (88.9% vs 34.7%, P < .05). Most patients migrated to medium or large hospitals rather than small hospitals (89% vs 11%, P < .0001) and to teaching rather than non-teaching institutions (82% vs 18%, P < .0001).ConclusionHospital size and teaching status significantly affected migration patterns for revTHA. Migration rates were significantly higher in small non-teaching hospitals in revTHA due to infection, periprosthetic fracture, instability, and mechanical complications. Over 80% of patients migrated to larger teaching hospitals.     

Current Epidemiology of Revision Total Knee Arthroplasty in the United States

Background

Revision surgery for failed total knee arthroplasty (TKA) continues to pose a substantial burden for the United States healthcare system. The predominant etiology of TKA failure has changed over time and may vary between studies. This report aims to update the current literature on this topic by using a large national database. Specifically, we analyzed: (1) etiologies for revision TKA; (2) frequencies of revision TKA procedures; (3) various demographics including payer type and region; and (4) the length of stay (LOS) and total charges based on type of revision TKA procedure.

The Utility of Serum d-Dimer for the Diagnosis of Periprosthetic Joint Infection in Revision Total Hip and Knee Arthroplasty

BackgroundThere is scarce and contradicting evidence supporting the use of serum d-dimer for the diagnosis of periprosthetic joint infection in revision total hip (THA) and knee (TKA) arthroplasty. Therefore, the purpose of this study is to test the accuracy of serum d-dimer against the 2013 International Consensus Meeting (ICM) criteria.MethodsA retrospective review was performed on a consecutive series of 172 revision THA/TKA surgeries performed by 3 fellowship-trained surgeons at a single institution (August 2017 to May 2019) and that had d-dimer performed during their preoperative workup. Of this cohort, 111 (42 THAs/69 TKAs) cases had complete 2013 ICM criteria tests and were included in the final analysis. Septic and aseptic revisions were categorized per 2013 ICM criteria (“gold standard”) and compared against serum d-dimer using an established threshold (850 ng/mL). Sensitivity, specificity, likelihood ratios, and positive/negative predictive values were determined. Independent t-tests, Fisher’s exact tests, chi-squared tests, and receiver operating characteristic curve analysis were performed.ResultsThere was no statistically significant difference in baseline demographics between septic and aseptic cases per 2013 ICM criteria. When compared to ICM criteria, d-dimer demonstrated high sensitivity (95.9%) and negative predictive value (90.9%) but low specificity (32.3%), positive predictive value (52.8%), and overall, poor accuracy (61%) to diagnose periprosthetic joint infection. Positive likelihood ratio was 1.42 while negative likelihood ratio was 0.13. The area under the curve (AUC) was 0.742.ConclusionSerum d-dimer has poor accuracy to discriminate between septic and aseptic cases using a described threshold in the setting of revision THA and TKA.     

Stiffness After Revision Total Knee Arthroplasty

Stiffness after a revision total knee arthroplasty (TKA) is a disabling complication that has largely been overlooked in the literature. This study attempts to define the prevalence of stiffness after revision TKA and to determine the risk factors that may lead to its development. Thirty-two knees (4.0%) presented with stiffness that we defined as a range of motion less than 90°. Risk factors were found to be poor preoperative range of motion, stiffness as primary indication for revision, younger age, shorter interval between index primary and revision TKA, presence of well-fixed components at the time of revision, postoperative wound drainage, and lower Charlson index. Because of the challenges of treating stiffness, efforts should be invested in preventing this complication.     

Use of Cementless Metaphyseal Fixation in Revision Total Knee Arthroplasty in the United States

BackgroundFixation options for revision total knee arthroplasty (rTKA) have expanded and now include cementless metaphyseal fixation. The utilization rates of these implants in the United States are not well known. The purpose of this study was to analyze trends in cementless metaphyseal fixation for rTKA within the American Joint Replacement Registry (AJRR).MethodsThe AJRR was queried for the years 2015-2019 to identify all rTKA with implant data. Trends in the use of cementless sleeves, metaphyseal cones, and any cementless metaphyseal fixation (sleeves + cones) were examined over the study period using logistic regression analysis.ResultsTwenty thousand two hundred and eighty rTKA were analyzed. Cementless metaphyseal fixation was used in 16% of rTKA and significantly increased over the study period (14% to 19%, P < .0001). Cementless metaphyseal fixation was more frequently utilized during revision for aseptic loosening than other diagnoses (OR 1.014, 95% CI 1.001-1.027). Cementless sleeve utilization decreased over time (11% to 9%, P = .004), driven by decreased use on the femur (4% to 2%, P < .0001). The use of cones increased significantly over time (3% to 9%, P < .0001), driven by increased use on the tibia (2% to 9%, P < .0001). Cones were 22 times more likely to be utilized on the tibia relative to the femur (P < .0001) and were more likely to be used in revisions for infection (OR 1.103, 95% CI 1.089-1.117) and aseptic loosening (OR 1.764, 95% CI 1.728-1.800).ConclusionCementless metaphyseal fixation has grown in popularity yet, still comprised only 16% of rTKA over a 5-year period. Most of the increase was due to the utilization of tibial metaphyseal cones.     

1.5-Stage Exchange Arthroplasty for Total Knee Arthroplasty Periprosthetic Joint Infections

BackgroundPeriprosthetic joint infection (PJI) in total knee arthroplasty (TKA) is a challenging problem. The purpose of this study was to outline a novel technique to treat TKA PJI. We define 1.5-stage exchange arthroplasty as placing an articulating spacer with the intent to last for a prolonged time.MethodsA retrospective review was performed from 2007 to 2019 to evaluate patients treated with 1.5-stage exchange arthroplasty for TKA PJI. Inclusion criteria included: articulating knee spacer(s) remaining in situ for 12 months and the patient deferring a second-stage reimplantation because the patient had acceptable function with the spacer (28 knees) or not being a surgical candidate (three knees). Thirty-one knees were included with a mean age of 63 years, mean BMI 34.4 kg/m², 12 were female, with a mean clinical follow-up of 2.7 years. Cobalt-chrome femoral and polyethylene tibial components were used. We evaluated progression to second-stage reimplantation, reinfection, and radiographic outcomes.ResultsAt a mean follow-up of 2.7 years, 25 initial spacers were in situ (81%). Five knees retained their spacer(s) for some time (mean 1.5 years) and then underwent a second-stage reimplantation; one of the five had progressive radiolucent lines but no evidence of component migration. Three knees (10%) had PJI reoccurrence. Four had progressive radiolucent lines, but there was no evidence of component migration in any knees.Conclusions1.5-stage exchange arthroplasty may be a reasonable method to treat TKA PJI. At a mean follow-up of 2.7 years, there was an acceptable rate of infection recurrence and implant durability.     

Aseptic Reoperations Within 1 Year of Primary Total Knee Arthroplasty Markedly Increase the Risk of Later Periprosthetic Joint Infection

BackgroundDespite the high rate of success of primary total knee arthroplasty (TKA), some patients are candidates for early aseptic reoperation. The goal of this study is to evaluate the risk of subsequent periprosthetic joint infection (PJI) in patients treated with an aseptic reoperation within 1 year of primary TKA.MethodsA retrospective review of our total joint registry compared 249 primary TKAs requiring an aseptic reoperation within 1 year following index arthroplasty to a control group of 17,867 TKAs not requiring reoperation within 1 year. Patients were divided into groups based on time from index TKA: (1) 90 days or less (114 TKAs) and (2) 91 to 365 days (135 TKAs). Mean age was 68 years with 57% female. Mean follow-up was 7 years.ResultsAt 2 years postoperatively, patients undergoing an aseptic reoperation within 90 days subsequently had a 9% PJI rate, while patients undergoing an aseptic reoperation between 91 and 365 days subsequently had a 3% PJI rate. The control group had a 0.4% PJI rate. Compared to the control group, patients undergoing an aseptic reoperation within 90 days had an elevated risk of PJI (hazard ratio, 9; P < .0001), as did patients who had a reoperation between 91 and 365 days (hazard ratio, 4; P < .0001).ConclusionAseptic reoperation within 1 year of primary TKA was associated with a notably increased risk of subsequent PJI.     

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.     

High Mortality After Total Knee Arthroplasty Periprosthetic Joint Infection is Related to Preoperative Morbidity and the Disease Process but Not Treatment

BackgroundPeriprosthetic joint infection (PJI) mortality rate is approximately 20%. The etiology for high mortality remains unknown. The objective of this study was to determine whether mortality was associated with preoperative morbidity (frailty), sequalae of treatment, or the PJI disease process itself.MethodsA multicenter observational study was completed comparing 184 patients treated with septic revision total knee arthroplasty (TKA) to a control group of 38 patients treated with aseptic revision TKA. Primary outcomes included time and the cause of death. Secondary outcomes included preoperative comorbidities and Charlson Comorbidity Index (CCMI) measured preoperatively and at various postoperative timepoints.ResultsThe septic revision TKA cohort experienced earlier mortality compared to the aseptic cohort, with a higher mortality rate at 90 days, 1, 2, and 3 years after index revision surgery (P = .01). There was no significant difference for any single cause of death (P > .05 for each). The mean preoperative CCMI was higher (P = .005) in the septic revision TKA cohort. Both septic and aseptic cohorts experienced a significant increase in CCMI from the preoperative to 3 years postoperative (P < .0001 and P = .002) and time of death (P < .0001 both) timepoints. The septic revision TKA cohort had a higher CCMI 3 years postoperatively (P = .001) and at time of death (P = .046), but not one year postoperatively (P = .119).ConclusionCompared to mortality from aseptic revision surgery, septic revision TKA is associated with earlier mortality, but there is no single specific etiology. As quantified by changes in CCMI, PJI mortality was associated with both frailty and the PJI disease process, but not treatment.     

Femoral Bow Predicts Postoperative Malalignment in Revision Total Knee Arthroplasty

Diaphyseal bowing may compromise axial alignment in revision total knee arthroplasty (TKA). 277 patients undergoing revision TKA were evaluated for coronal bowing and hip–knee–ankle (HKA) axis. The mean femoral bow was 1.52° ± 0.18° varus (− 10.1° to + 8.4°). The mean tibial bow was 1.25° ± 0.13° valgus (− 5.9° to + 10°). HKA axis averaged 3.08° ± 0.35° varus preoperatively compared to 0.86° ± 0.25° varus postoperatively. Inter-rater and intra-rater reliability was high. Femoral bow greater than 4° significantly correlated with postoperative HKA axis malalignment (r = 0.402, P = 0.008). 39.7% of patients deviated 3° or greater from a neutral mechanical axis with a significant difference in femoral bow (0.94° ± 0.31°, P = 0.003). Diaphyseal bowing clearly has an important effect on postoperative limb alignment in revision TKA.     

Acetic Acid as Part of a Debridement Protocol During Revision Total Knee Arthroplasty

Background

Thorough debridement is mandatory in revision for infected total knee arthroplasties (TKA). We investigated a novel adjuvant chemical debridement strategy using acetic acid (AA) that seeks to create a hostile environment for microorganisms. We report the first orthopedic in vivo series using an AA soak in infected TKAs. We also investigated the in vitro efficacy of AA against bacteria isolated from these knees.

Rotating Hinge Implants for Complex Primary and Revision Total Knee Arthroplasty

Background

Contemporary rotating hinge knee (RHK) prosthesis has shown improved survival rates over earlier generations. However, reports of high complication and mechanical failure rates highlight the need for more clinical outcome data in the complex primary and revision setting. The purpose of this study is to report our results of using a contemporary rotating hinge for complex primary and revision total knee arthroplasty.

Long-Term Survival of Semi-Constrained Total Knee Arthroplasty for Revision Surgery

Semi-constrained implants provide stability in the setting of soft-tissue deficiency in revision total knee arthroplasty (TKA). This study evaluated our institution’s long-term survival results with a semi-constrained implant used in the revision TKA setting. 234 semi-constrained revision total knee arthroplasties were performed in 209 patients. The average follow-up was 9 years. Forty repeat revisions were performed. 5-year survival was 91% and 10-year survival was 81%. Male gender significantly increased the risk of revision. At 10 years the average range of motion, pain level, and Knee Society score improved significantly (P < 0.001). Ninety percent of patients reported an improvement in their knee. The semi-constrained implant used in revision knee arthroplasty has acceptable implant survival and functional outcomes in the long-term follow-up period.     

Risk Factors and Costs Associated With Clostridium difficile Colitis in Patients With Prosthetic Joint Infection Undergoing Revision Total Hip Arthroplasty

Background

With the increased demand for primary total hip arthroplasty (THA) and corresponding rise in revision procedures, it is imperative to understand the factors contributing to the development of Clostridium difficile colitis. We aimed to provide a detailed analysis of: (1) the incidence of; (2) the demographics, lengths of stay, and total costs for; and (3) the risk factors and mortality associated with the development of C. difficile colitis after revision THA.

Patellar Rebar Augmentation in Revision Total Knee Arthroplasty

BackgroundIn revision total knee arthroplasty, osteolysis, mechanical abrasion, and infection may leave patellar bone stock severely attenuated with cavitary and/or segmental rim deficiencies that compromise fixation of patellar implant pegs. The purpose of this study was to retrospectively review the use of cortical “rebar” screws to augment cement fixation in revision patelloplasty.MethodsFrom 2006 to 2018, dorsal patellar rebar technique was used for patellar reconstruction in 128 of 1037 revision total knee arthroplasty cases (12.3%). Follow-up was achieved with serial radiographs and prospective comparison of Knee Society Scores (KSSs) for clinical outcome. Complications and implant failures requiring reoperation or modified rehabilitation were also assessed.ResultsOf the 128 patellar revisions performed using the rebar technique, 69 patients were women and 59 patients were men. The average age of the group was 69.5 years (range, 32-83 years). The mean follow-up of the cohort was 37 months (range, 13-109 months). The most common causes for revision were kinematic conflict, periprosthetic joint infection, and aseptic loosening. The median number of rebar screws used was 5 (range, 1-13). Preoperative KSSs for the study cohort averaged 50 (range, 0-90) At latest follow-up, mean KSS was 85 (range, 54-100). There were 4 patellar-related complications (3.1%) with no implant failures at study conclusion. Retrieval analysis revealed rigid fixation of the reconstructed patellar component in all cases.ConclusionsPatellar rebar screw augmentation is a useful technique when there are significant cavitary deficiencies and limited segmental rim deficiencies. This technique allows the surgeon to extend indications for patellar revision arthroplasty.     

Revision Total Knee Arthroplasty for Periprosthetic Joint Infection Is Associated With Increased Postoperative Morbidity and Mortality Relative to Noninfectious Revisions

Background

Periprosthetic joint infection (PJI) after primary total knee arthroplasty (TKA) is a devastating complication. The short-term morbidity profile of revision TKA performed for PJI relative to non-PJI revisions is poorly characterized. The purpose of this study is to determine 30-day postoperative outcomes after revision TKA for PJI, relative to primary TKA and aseptic revision TKA.

The Clinical Outcome of Different Total Knee Arthroplasty Designs in One-Stage Revision for Periprosthetic Infection

BackgroundDespite the growing number of studies reporting on the best surgical treatment in the management of periprosthetic joint infection, there are no robust data regarding the type of infected prosthesis before any kind of exchange arthroplasty. To overcome these shortcomings, we asked the following questions: (1) What is the survivorship of nonhinged and hinged knee implants after one-stage exchange arthroplasty and (2) what is the functional outcome after one-stage exchange procedure focusing on knee prostheses and the type of prior infected knee implant. In a secondary radiographic analysis, we also investigated if (3) the type of femoral bone morphology measured by the inner femoral diameter influences the rate of aseptic failures also in patients with periprosthetic joint infection.MethodsBetween January 2011 and December 2017, we performed a retrospective designed study including 211 patients with infected knee prostheses. After all, seventy-six percent (161 of 211 patients) were available for final data analysis. These patients were divided into four groups as per the performed implant revision: (1) bicondylar total knee arthroplasty to rotating hinge implant, (2) rotating hinge to rotating hinge implant, (3) rotating hinge to full hinge implant, and (4) full hinge to full hinge implant. The mean follow-up (FU) was six years (range 3 to 9; standard deviation = 1.9), whereas a minimum FU of three years was required for inclusion. Survivorship and group analysis were performed, and the functional outcome was assessed using postoperative Oxford Knee Scores at the latest FU (60-point scale with lower scores representing less pain and greater function). Furthermore, in all cases, femoral bone morphology was determined as per the Citak classification system.ResultsAt the final FU, the overall surgical revision rate was 23% (37/161 patients) with nine percent (15/161 patients) suffering a periprosthetic joint infection relapse. Group 1 consisted of 51, group 2 consisted of 67, group 3 consisted of 24, and group 4 consisted of 19 patients. The lowest overall revision rate was found in group 2 (16%, n = 11), compared with 28% (n = 14) in group 1, 29% (n = 7) in group 3, and 26% (n = 5) in group 4; however, no significant differences were found (P = .902). The functional outcome (Oxford Knee Score) was clinically constant in all groups, with 32 points in group 1, 37 points in group 2, 33 points in group 3, and 35 points in group 4 (P = .107).Concerning the number of patients with aseptic loosening as per bone morphology, 74% (14/19) of all aseptic loosening cases appeared in femoral bone type C morphologies according to Citak (75% in group 1, 56% in group 2, 100% in group 3, and 100% in group 4).ConclusionsThe results obtained suggest a generally high overall revision rate (25%) with a good infection control rate (91%). Although we were unable to work out a specific group of patients with a statistically significant differing outcome, it is interesting to see that hinged implants can reach more or less the same functional outcome and revision rates as nonhinged implants, when it comes to revision surgeries. In this study, a relatively high number of aseptic failures contributed to a high overall revision rate. In this context, the bone morphology, measured as per the Citak classification system, could be confirmed as a risk factor for aseptic failures also in septic patients. Therefore, further research might focus on revision knee implant design.     

Short Term Outcomes of Revision Total Knee Arthroplasty

Few studies have assessed postoperative complications in revision total knee arthroplasty (rTKA). The aim of this study was to assess which preoperative factors are associated with postoperative complications in rTKA. Using the National Surgical Quality Improvement (NSQIP) database, we identified patients undergoing rTKA from 2010 to 2012. Patient demographics, comorbidities, and complications within thirty days of surgery were analyzed. A total of 3421 patients underwent rTKA. After adjusted analysis, dialysis (P = 0.016) was associated with minor complications. Male gender (P = 0.03), older age (P = 0.029), ASA class > 2 (P = 0.017), wound class > 2 (P < 0.0001), emergency operation (P = 0.038), and pulmonary comorbidity (P = 0.047) were associated with major complications.     

Intraoperative Fracture During Aseptic Revision Total Knee Arthroplasty

Bone encountered during revision knee arthroplasty is compromised and predisposed to fracture. This study reports the rate, location, timing, treatment, and outcome of intraoperative fractures occurring during revision knee arthroplasty. Between 1997 and 2011, 2836 aseptic revisions were performed. Ninety-seven fractures were identified in 89 patients (3%). Fifty occurred in femora, 42 in tibiae, and 5 in patellae. Forty-six occurred during exposure, 21 during bony preparation, 17 during trialing, and 13 during final component placement. Treatment included fixation (n = 43), observation (n = 21), component build-up (n = 17), bone grafting (n = 6), and a combination (n = 3). Ninety-four percent of fractures united. Fifteen patients required a re-revision (17%), of which infection was the leading cause (n = 5).