Undergoing Revision Total Knee Arthroplasty Research Articles

The oxford knee score minimal clinically important difference for revision total knee arthroplasty

BackgroundMinimal clinically important difference (MCID) is crucial for interpreting meaningful improvements in patient-reported outcome measures (PROMs). No previous study has evaluated the MCID for the Oxford Knee Score (OKS) in revision total knee arthroplasty (TKA). This study aimed to propose the OKS MCID for revision TKA. MethodsProspectively collected data from 191 patients who underwent revision TKA at a single institution was analysed. Clinical assessment was performed preoperatively and at 2 years using OKS and Short-Form 36 Physical Component Score (SF-36 PCS). MCID was evaluated with a three-pronged methodology, using (1) anchor-based method with linear regression, (2) anchor-based method with receiver operating characteristic (ROC) and area under curve (AUC), (3) distribution-based method with standard deviation (SD). The anchors used were improvement in SF-36 PCS ≥ 12, patient satisfaction, and implant survivorship following revision TKA. ResultsThe MCID determined by anchor-based linear regression method using improvements in SF-36 PCS was 4.9 points. The MCID determined by anchor-based ROC was 10.5 points for satisfaction (AUC = 74.8%) and 13.5 points for implant survivorship (AUC = 73.7%). The MCID determined by distribution-based method of 0.5 SD was 4.7. ConclusionThe proposed MCID for OKS following revision TKA is 4.9 points. Patients who achieve an improvement in OKS of at least 10.5–13.5 points by 2 years are likely to be satisfied with their surgery and not require a subsequent re-revision TKA. Patients undergoing revision TKA should aim for an improvement in OKS of at least 10.5–13.5 points as a target score.

Conversion total knee arthroplasty: A case complexity between primary and revision total knee arthroplasty

BackgroundConversion total knee arthroplasty (TKA) may represent a more complex procedure compared with primary TKA. The purpose of this study was to compare 30-day complications between conversion TKA and primary, non-conversion TKA as well as between conversion TKA and revision TKA on a national scale using a multi-center surgical registry. MethodsAdult patients undergoing conversion TKA from 2006 to 2018 were identified in the National Surgical Quality Improvement Program database and were compared with patients who underwent primary TKA and aseptic revision TKA. In this analysis, 30-day complications were assessed. Bivariate analyses, including chi-squared and analysis of variance, and multivariate logistic regressions were performed. ResultsOf 299,065 total patients undergoing knee arthroplasty, 1,310 (0.4%) underwent conversion TKA, 275,470 (92.1%) underwent primary TKA, and 22,285 (7.5%) underwent revision TKA. Following adjustment, patients who underwent conversion TKA were more likely to have increased risks of any complications (P < 0.001), mortality (P = 0.021), wound complications (P < 0.001), cardiac issues (P = 0.018), bleeding requiring transfusion (P < 0.001), and reoperation (P = 0.002) relative to primary TKA patients. Compared with patients who underwent revision TKA, conversion TKA patients were less likely to have septic complications (P = 0.009). ConclusionConversion TKA is associated with significantly higher rates of complications compared with primary, non-conversion TKA, but less risk of sepsis compared with revision TKA. Because current reimbursement classifications do not account for the case complexity of a conversion TKA, new classifications should be implemented with reimbursements for conversion TKA approximating reimbursements for revision TKA.

Defining the minimal clinically important difference for theknee society score following revision total knee arthroplasty.

No previous study has evaluated the MCID for revision total knee arthroplasty (TKA). This study aimed to identify the MCID for the Knee Society Score (KSS), for revision TKA. Prospectively collected data from 270 patients who underwent revision TKA at a single institution was analysed. Clinical assessment was performed preoperatively, at 6months and 2years using Knee Society Function Score (KSFS) and Knee (KSKS) Scores, and Oxford Knee Score (OKS). MCID was evaluated with a three-pronged methodology, using (1) anchor-based method with linear regression, (2) anchor-based method with receiver operating characteristic (ROC) and area under curve (AUC), (3) distribution-based method with standard deviation (SD). The anchors used were improvement in OKS≥5, patient satisfaction, and implant survivorship following revision TKA. The cohort comprised 70% females, with mean age of 69.0years, that underwent unilateral revision TKA. The MCID determined by anchor-based linear regression method using OKS was 6.3 for KSFS, and 6.6 for KSKS. The MCID determined by anchor-based ROC was between 15 and 20 for KSFS (AUC: satisfaction=71.8%, survivorship=61.4%) and between 33 and 34 for KSKS (AUC: satisfaction=76.3%, survivorship=67.1%). The MCID determined by distribution-based method of 0.5 SD was 11.7 for KSFS and 11.9 for KSKS. The MCID of 6.3 points for KSFS, and 6.6 points for KSKS, is a useful benchmark for future studies looking to compare revision against primary TKA outcomes. Clinically, the MCID between 15 and 20 for KSFS and between 33 and 34 for KSKS is a powerful tool for discriminating patients with successful outcomes after revision TKA. Implant survivorship is an objective and naturally dichotomous outcome measure that complements the subjective measure of patient satisfaction, which future MCID studies could consider utilizing as anchors in ROC. II.

Pain associated with cemented and uncemented long-stemmed tibial components in revision total knee arthroplasty.

Stemmed tibial components are frequently used in revision total knee arthroplasty (TKA). The purpose of this study was to evaluate patient satisfaction, overall pain, and diaphyseal tibial pain in patients who underwent revision TKA with cemented or uncemented stemmed tibial components. This is a retrospective cohort study involving 110 patients with revision TKA with cemented versus uncemented stemmed tibial components. Patients who underwent revision TKA with stemmed tibial components over a 15-year period at a single institution with at least two-year follow-up were assessed. Pain was evaluated through postal surveys. There were 63 patients with cemented tibial stems and 47 with uncemented stems. Radiographs and Knee Society Scores were used to evaluate for objective findings associated with pain or patient dissatisfaction. Postal surveys were analyzed using Fisher's exact test and the independent-samples t-test. Logistic regression was used to adjust for age, sex, and preoperative bone loss. No statistically significant differences in stem length, operative side, or indications for revision were found between the two cohorts. Tibial pain at the end of the stem was present in 25.3% (16/63) of cemented stems and 25.5% (12/47) of uncemented stems (p = 1.000); 74.6% (47/63) of cemented patients and 78.7% (37/47) of uncemented patients were satisfied following revision TKA (p = 0.657). There were no differences in patient satisfaction, overall pain, and diaphyseal tibial pain in cemented and uncemented stemmed tibial components in revision TKA. Patient factors, rather than implant selection and surgical technique, likely play a large role in the presence of postoperative pain. Stemmed tibial components have been shown to be a possible source of pain in revision TKA. There is no difference in patient satisfaction or postoperative pain with cemented or uncemented stemmed tibial components in revision TKA. Cite this article: Bone Joint J2021;103-B(6 Supple A):165-170.

Outcomes of Tourniquet-Less Revision Total Knee Arthroplasty: A Matched Cohort Analysis.

A tourniquet is routinely used in total knee arthroplasty (TKA) to limit perioperative blood loss and increase the visibility of the surgeon's field of view. This study aims to evaluate the postoperative clinical outcomes and complications associated with tourniquet use in revision TKA. We conducted a retrospective review of 1,904 consecutive patients who underwent revision TKA. Propensity score-based matching was done to adjust for baseline differences in patient demographics and procedure details. Propensity score matching resulted in a cohort of 548 revision total joint arthroplasty patients, 274 (50.0%) of whom were tourniquet patients matched to 274 (50.0%) tourniquet-less patients. Multivariate regression analyses demonstrated that, compared with the tourniquet-less cohort, the tourniquet cohort had significantly less intraoperative (413.7 to 353.2 mL, P < 0.01) and total perioperative (1,548.7 to 1,417.8 mL, P < 0.01) blood loss. However, no significant differences were present in total perioperative (8.4%, 6.6%, P = 0.43) transfusion rates. The tourniquet cohort had increased length of stay (3.2 to 3.7 days, P < 0.001) and 30-day readmissions (P = 0.04). This study demonstrated that although omitting the tourniquet in revision TKA leads to markedly increased perioperative blood loss, notable differences in perioperative transfusion rates were not observed. Furthermore, revision TKA without tourniquet use was associated with reduced postoperative length of stay, 30-day readmissions, and increased range of flexion.

Impact of Preoperative Opioid Use on Patient-Reported Outcomes after Revision Total Knee Arthroplasty: A Propensity Matched Analysis.

This is a retrospective study. Prior studies have characterized the deleterious effects of narcotic use in patients undergoing primary total knee arthroplasty (TKA). While there is an increasing revision arthroplasty burden, data on the effect of narcotic use in the revision surgery setting remain limited. Our aim was to characterize the effect of active narcotic use at the time of revision TKA on patient-reported outcome measures (PROMs). A total of 330 consecutive patients who underwent revision TKA and completed both pre- and postoperative PROMs was identified. Due to differences in baseline characteristics, 99 opioid users were matched to 198 nonusers using the nearest-neighbor propensity score matching. Pre- and postoperative knee disability and osteoarthritis outcome score physical function (KOOS-PS), patient reported outcomes measurement information system short form (PROMIS SF) physical, PROMIS SF mental, and physical SF 10A scores were evaluated. Opioid use was identified by the medication reconciliation on the day of surgery. Propensity score-matched opioid users had significantly lower preoperative PROMs than the nonuser for KOOS-PS (45.2 vs. 53.8, p < 0.01), PROMIS SF physical (37.2 vs. 42.5, p < 0.01), PROMIS SF mental (44.2 vs. 51.3, p < 0.01), and physical SF 10A (34.1 vs. 36.8, p < 0.01). Postoperatively, opioid-users demonstrated significantly lower scores across all PROMs: KOOS-PS (59.2 vs. 67.2, p < 0.001), PROMIS SF physical (43.2 vs. 52.4, p < 0.001), PROMIS SF mental (47.5 vs. 58.9, p < 0.001), and physical SF 10A (40.5 vs. 49.4, p < 0.001). Propensity score-matched opioid-users demonstrated a significantly smaller absolute increase in scores for PROMIS SF Physical (p = 0.03) and Physical SF 10A (p < 0.01), as well as an increased hospital length of stay (p = 0.04). Patients who are actively taking opioids at the time of revision TKA report significantly lower preoperative and postoperative outcome scores. These patients are more likely to have longer hospital stays. The apparent negative effect on patient reported outcomes after revision TKA provides clinically useful data for surgeons in engaging patients in a preoperative counseling regarding narcotic use prior to revision TKA to optimize outcomes.

Allergy Testing Has No Correlation with Intraoperative Histopathology from Revision Total Knee Arthroplasty for Implant-Related Metal Allergy.

Lymphocyte transformation testing (LTT) is often used in the workup for possible metal allergy after total knee arthroplasty (TKA) but the correlation of this test with other diagnostic metal-allergy findings in patients undergoing revision TKA for suspected metal allergy has not been established. A single-center, single-surgeon cohort of 19 TKAs in which both components were revised for presumed implant-related metal allergy based on history, physical, and LTT testing, to nonnickel-containing implants were retrospectively identified. Histopathologic samples obtained intraoperatively were semiquantitatively analyzed using both the Hospital for Special Surgery (HSS) synovial pathology score and the Campbell aseptic lymphocyte-dominant vasculitis-associated lesion (ALVAL) score. As histopathology control group, we included in the study an additional cohort of 17 patients who received aseptic revision TKA and had no history of reported or tested metal sensitivity. All preoperative LTT results were highly reactive to nickel. However, this did not correlate with local periarticular tissue response in 18 of 19 cases which demonstrated a low HSS synovial score (mean: 3.8 ± 2.8, of a maximum score of 28) and the low Campbell ALVAL scores (mean: 2.5/10 ± 1.3, of a maximum score of 10). There were not any significant differences between the study group (suspected implant-related metal allergy) and the control group (nonsuspected implant-related metal allergy) in regard to (1) the Campbell score and (2) the HSS synovial inflammatory score. Knee Society Clinical Rating System (KSCRS) function score improved significantly after revision (mean postoperative increase: 34.0 ± 17. 2; p < 0.001), as well as mean visual analog scale (VAS) pain (mean postoperative decrease: 33.3 ± 26.4; p < 0.01) score. The short-term survival rate (at mean follow-up of 26.1 months) of this patient cohort was 100%. In this cohort of revised TKA patients with suspected nickel allergy based on clinical presentation and LTT positive results, intraoperative histopathology was essentially normal. However, all patients with suspected nickel allergy showed a significant clinical and functional improvement with excellent short-term survival rates. The clinical significance of a positive LTT needs further study.

Early Aseptic Loosening with Increased Presence and Severity of Backside Burnishing in the Optetrak Logic Posterior-Stabilized Total Knee Arthroplasty Femoral Component.

Concerns persist that the Optetrak Logic posterior-stabilized (PS) total knee arthroplasty (TKA) femoral component might correlate with early failures due to aseptic loosening. The primary aim of this study was to examine if the use of the Optetrak Logic PS femoral component is associated with early (<5 years) and more extensive aseptic loosening compared with other PS femoral components. This is a single-institution retrieval analysis and revision registry study (based on prospectively collected data) of 27 failed primary PS TKA patients with loose femoral components that underwent revision TKAs between 2016 and 2019. Patients were stratified by components type: Group A (n = 16) received the Optetrak Logic PS femoral component, while Group B (n = 11) received other PS femoral components. Burnishing (macroscopic polishing of the component's backside) was observed and graded as a marker for relative motion at the cement-implant interface. No significant differences were found between the two groups regarding the baseline demographic, radiographic, and clinical characteristics. Mean length of implantation for Group A (3.8 ± 2.9 years) was significantly shorter (p < 0.001) than that of Group B (12.0 ± 6.7 years). A significant difference (p = 0.009) was found in presence of backside femoral burnishing between Group A (15 of 16 patients; 93.8%) and group B (5 of 11 patients; 45.6%). Furthermore, we found a significant difference (p < 0.001) in the severity of burnishing between Group A (13 of 16 patients with severe degree of burnishing; 81.3%) and Group B (1 of 11 patients with severe degree of burnishing; 9.1%). In contrast to Group B, a distinctive macroscopic pattern found in Logic retrieved femoral components (Group A) was the total absence of cement in the backside surface. The use of the Optetrak Logic PS TKA femoral component was associated with early aseptic loosening and increased presence and severity of backside burnishing with early cement-implant interface debonding compared with other commercially available types of PS TKA femoral components. The earlier failure rate with this implant is of concern.

Outcomes of Rotating-hinge Total Knee Arthroplasty Following Complex Primary and Revision Total Knee Arthroplasty

In complex primary and revision total knee arthroplasty (TKA), rotating-hinge TKA (RH-TKA) prostheses play an important role. Compared to early fixed-hinge knee designs, new implants that include rotating platforms and improved hinge constructs may offer improvements in both survival and clinical outcomes. We sought to evaluate early survival following complex primary and revision TKA with a rotating-hinge knee prosthesis. We retrospectively reviewed a consecutive series of patients (n=47, 48 knees) who underwent revision TKA using an RH-TKA system. The mean age was 73 years (range, 37 – 86). The mean body mass index was 29 (range, 16.3 – 45.9) and the median ASA score was 3 (IQR, 2 – 3). As mortality was high, we performed a Kaplan-Meier analysis to evaluate survival, with death as failure. The median follow-up was 2.5 years (range, 0.07 – 9.8). Revision-free survival was 97% at a median 2.5 years of follow-up. Overall mortality was 46% (17/37) and survival free from death was 69% (49% - 82%) at a median of 2.5 years. Most reoperations were due to infection (5/12), following by wound-related complications (2/12) and hematomas (2/12). A high postoperative complication rate and mortality are evident in TKA using a hinged knee prosthesis in complex revision TKA. If the indication and surgical technique are matched to the complexity of the case, this type of implant offers a feasible salvage procedure.

Outcomes of the rotating hinge knee in revision total knee arthroplasty with a median follow-up of 6.2\u2009years

BackgroundThe purpose of this study was to determine the mid-term clinical, radiographic and health-related quality of life (HRQoL) outcomes and define the survival rate in patients who had undergone revision total knee arthroplasty (TKA) using the single rotating hinged knee (RHK) design.MethodsBetween January 2004 and December 2013, 125 revision TKAs were performed at our institution using the single RHK implant. We conducted both a retrospective analysis of prospectively collected outcome data of these patients and a prospective follow-up study of all 39 living patients (41 knees). The follow-up phase included an optional extra follow-up visit, PROM questionnaires, and plain radiographs.ResultsThe ten-year Kaplan-Meier survival rate of the revision RHK knees was 81.7% (95% CI 71.9–91.6%) with re-revision for any reason as the endpoint. Overall, 15 knees (12% of the total) underwent re-revision surgery during the follow-up. The median follow-up was 6.2 years (range, 0–12.7 years) post-operatively for the baseline group. One mechanical hinge mechanism-related failure occurred without any history of trauma or infection. At the time of the final follow-up, the majority of patients evinced a fairly good clinical outcome measured with patient-reported outcome measures and none of the components were radiographically loose.ConclusionWe found that in patients undergoing complex revision TKA, fairly good functional outcome and quality of life can be achieved using an RHK implant. Further, it seems that in this type of patient cohort, revision TKA using an RHK implant relieves pain more than it improves ability to function. The NexGen® RHK design can be regarded as a suitable option in complex revision TKA.

Diagnostic Utility of a Novel Point-of-Care Test of Calprotectin for Periprosthetic Joint Infection After Total Knee Arthroplasty: A Prospective Cohort Study.

Despite several synovial fluid biomarkers for the diagnosis of periprosthetic joint infection (PJI) having been investigated, point-of-care (POC) tests using these biomarkers are not widely available. Synovial calprotectin has recently been reported to effectively exclude the diagnosis of PJI. Thus, the objective of this study was to test the value of a calprotectin POC test for PJI diagnosis in patients undergoing total knee arthroplasty (TKA) using the 2013 Musculoskeletal Infection Society (MSIS) PJI diagnosis criteria as the gold standard. Synovial fluid samples were prospectively collected from 123 patients who underwent revision TKA at 2 institutions within the same health-care system from October 2018 to January 2020. The study was conducted under institutional review board approval. Data collection comprised demographic, clinical, and laboratory data in compliance with the MSIS criteria. Synovial fluid samples were analyzed by calprotectin POC tests in accordance with the manufacturer's instructions. Revisions were categorized as septic or aseptic using MSIS criteria by 2 independent reviewers blinded to the calprotectin results. Calprotectin test performance characteristics with sensitivities, specificities, positive predictive values, negative predictive values, and areas under the receiver operating characteristic curve (AUC) were calculated for 2 different PJI diagnosis scenarios: (1) a threshold of ≥50 mg/L, and (2) a threshold of ≥14 mg/L. According to the MSIS criteria, 53 revision TKAs were septic and 70 revision TKAs were aseptic. In the ≥50-mg/mL threshold scenario, the calprotectin POC performance showed a sensitivity of 98.1%, a specificity of 95.7%, a positive predictive value of 94.5%, a negative predictive value of 98.5%, and an AUC of 0.969. In the ≥14-mg/mL threshold scenario, the sensitivity was 98.1%, the specificity was 87.1%, the positive predictive value was 85.2%, the negative predictive value was 98.4%, and the AUC was 0.926. The calprotectin POC test has excellent PJI diagnostic characteristics, including high sensitivity and specificity in patients undergoing revision TKA. This test could be effectively implemented as a rule-out test. However, further investigations with larger cohorts are necessary to validate these results. Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Preoperative Mental Health Influences Patient-Reported Outcome Measures and Satisfaction After Revision Total Knee Arthroplasty

BackgroundA higher prevalence of mental health conditions has been reported in patients undergoing revision total knee arthroplasty (rTKA). This study investigated the effect of preoperative mental health on patient-reported outcome measures (PROMs) and satisfaction after rTKA. MethodsA total of 245 patients who underwent rTKA in 2004-2018 were identified from our institutional joint registry. The most common indications were aseptic loosening (n = 111), infection (n = 70), and instability (n = 35). 36-item Short-Form health survey (SF-36) mental component summary (MCS) was used to stratify the cohort into: Low-MCS (SF-36 MCS <50; n = 112) and control (SF-36 MCS ≥50; n = 133) groups. Knee Society score, Oxford knee score, SF-36 physical score, and a satisfaction questionnaire were used to compare the low-MCS and control at 6 months and 2 years. ResultsAll PROMs were poorer in the low-MCS group at 6 months and 2 years. However, both groups demonstrated a comparable improvement in each PROM and a similar proportion attained the minimal clinically important difference. Fewer patients in the low-MCS group were satisfied at 2 years (72.2% vs 84.5%, P = .045). Lower preoperative SF-36 MCS was independently associated with increased odds of dissatisfaction (OR 1.037, 95% CI 1.004-1.070, P = .027). Although the change in SF-36 MCS was greater in the low-MCS group, the final value remained lower at 2 years. ConclusionWhile patients with poor mental health had inferior PROMs preoperatively and postoperatively, a similar percentage experienced a clinically meaningful improvement at 2 years. Perioperative optimization of psychological factors should still be emphasized as these patients were at a higher risk of dissatisfaction after rTKA.

Heterotopic Ossification Negatively Influences Range of Motion After Revision Total Knee Arthroplasty

BackgroundThe incidence of heterotopic ossification (HO) after total knee arthroplasty (TKA) varies and is of unclear clinical significance. This study aimed to identify the incidence of HO in patients undergoing revision TKA for either stiffness or aseptic loosening/instability and determine if the presence of HO is associated with inferior absolute range of motion (ROM) and ROM gains. MethodsEighty-seven patients were prospectively enrolled and separated into 2 cohorts to evaluate ROM after revision TKA (2017-2019). Group 1 (N = 40) patients were revised for stiffness, while group 2 (N = 47) patients were revised for either aseptic loosening or instability. Goniometer-measured ROM values were obtained preoperatively and at 6 weeks, 6 months, and 1 year postoperatively. Statistical analysis included a Fisher’s exact test to assess for an association between preoperative HO and final ROM at 1 year after revision TKA. ResultsHO was identified on preoperative radiographs in 17 patients (20%). There was a significantly higher rate of preoperative HO in patients revised for stiffness compared to patients revised for instability or loosening (30% vs 11%; P = .03). Five cases of HO qualitatively identified as most clinically severe were associated with lower ROM at each time point compared to the remainder of HO cases in this study cohort (P < .02). ConclusionThe presence of HO is greater in patients undergoing revision TKA for stiffness. Additionally, HO severity appears to have a major effect on preoperative and postoperative ROM trajectory. This information should help guide patient expectations and highlight the need for a comprehensive, standardized classification system for HO.

Early Survivorship of Newly Designed Highly Porous Metaphyseal Tibial Cones in Revision Total Knee Arthroplasty.

BackgroundMetaphyseal cones provide durable fixation in revision total knee arthroplasty (TKA). However, there is a paucity of data on the outcomes of a new porous cone design. As such, the goal of this study was to analyze the early survivorship in patients undergoing revision TKA with this cone.MethodsWe retrospectively reviewed 163 revision TKAs with a newly designed porous tibial cone from 2016 to 2018. Mean age was 67 years, and mean body mass index was 33 kg/m2. Minimum follow-up duration was 2 years. Most patients were revised for aseptic loosening (46%), 2-stage periprosthetic joint infection (PJI) reimplantation (28%), or instability (15%). Most were varus-valgus constrained (65%) or hinged (32%) constructs. The majority had hybrid tibial stem fixation (74%). A multivariate Cox regression analysis was used to identify risk factors for reoperation.ResultsSurvivorship free from re-revision for aseptic loosening, any nonmodular revision, and any reoperation was 100%, 96%, and 86% at 2 years, respectively. No patients were revised for aseptic loosening. Six (4%) tibial cones were removed for PJI, one of which was loose. There were 23 reoperations (14%), most commonly for PJI (10%). Multivariate analysis identified PJI reimplantation (hazard ratios [HR] = 4.2, P = .002), males (HR = 2.9, P = .02), and hinged constructs (HR = 2.7, P = .02) as significant risk factors for reoperation.ConclusionsIn a complex revision TKA cohort with a new highly porous tibial cone, in which most patients received hybrid stem fixation and nonlinked and linked constraint, there was 100% survival free from re-revision for aseptic loosening at 2 years. Longer term follow-up is required.

Knee Arthroscopy Prior to Revision TKA Is Associated with Increased Re-Revision for Stiffness.

This is an experimental study. As knee arthroscopy may be used as a suitable temporizing alternative prior to revision surgery, knee arthroscopy potentially may be a risk factor for subsequent adverse outcomes after revision total knee arthroplasty (TKA). This study aimed to evaluate the impact of prior knee arthroscopy on outcomes of subsequent TKA revision surgery. We identified 1,689 consecutive patients who underwent revision TKA: (1) patients with no prior knee arthroscopy (n = 1,549) and (2) patients with knee arthroscopy prior to revision TKA (n = 140). A control group of matched revision TKA patients who did not undergo prior knee arthroscopy was identified (700 patients), using one-to-five matching. Matched patients with prior knee arthroscopy demonstrated an increased likelihood of requiring re-revision (odds ratio [OR], 2.06, p < 0.001), particularly for stiffness (OR, 2.72, p < 0.02) compared with patients who underwent revision TKA without prior knee arthroscopy. Knee arthroscopy demonstrated a time-dependent impact on revision TKA outcomes, with an increased likelihood of requiring re-revision for patients who underwent knee arthroscopy within 6 months prior to revision TKA compared with patients who underwent knee arthroscopy within 6 to 12 months prior to revision TKA (OR, 3.16, p < 0.04). This cohort matched study shows that patients who had prior knee arthroscopy demonstrated a significantly higher likelihood of requiring re-revision compared with patients who underwent revision TKA without prior knee arthroscopy. Additionally, there was a significant increased likelihood in requiring re-revision for patients who had prior knee arthroscopy within 6 months. This provides clinically useful information for counseling of patients who are considering temporizing their symptoms with knee arthroscopy prior to revision TKA.

Rheumatoid Arthritis Versus Osteoarthritis in Patients Receiving Revision Total Knee Arthroplasty in the United States: Increased Perioperative Risks? A National Database-Based Propensity Score-Matching Study.

The impacts of rheumatoid arthritis (RA) on perioperative risks among patients undergoing revision total knee arthroplasty (rTKA) have not been investigated yet. Thus, we hypothesized that patients with RA sustained increased perioperative risks and higher resource consumption burdens as compared to patients with osteoarthritis (OA) during the perioperative period. The National Inpatient Sample (NIS) database was used to compare the demographic characteristics, major in-hospital complications, resource consumptions, and in-hospitalization mortality between patients with RA and OA after rTKA. A 1:1 propensity score-matching, χ2 test, independence-sample T-test, and logistic regression analysis were done in statistical analyses to answer our hypotheses. 4.3% (6363/132,405) of rTKA patients were diagnosed with RA. They tended to be women and received revision for infection but with similar ages as compared to patients with OA. Except for acute postoperative anemia (odds ratio [OR] = 1.196), blood transfusion (OR = 1.179), prolonged hospitalization (OR = 1.049), and higher total cost (OR = 1.145), patients with RA sustained decreased odds of acute renal failure (OR = 0.804) and urinary complications (OR = 0.467). Besides, the other observed in-hospital complications showed no differences between patients with RA and OA. Despite consuming greater in-hospital resources, patients with RA did not suffer increased odds of most in-hospital complications and in-hospital mortality for a revision TKA during the perioperative period. Compared with patients with OA, patients with RA sustained equivalent perioperative risks in the United States between 2002 and 2014.

Long-term results of revision total knee arthroplasty using a rotating hinge implant

BackgroundRotating hinge implants are commonly used in revision total knee arthroplasty (TKA) in the setting of significant ligamentous instability or bone deficiency. These highly constrained implants have been associated with variable clinical outcomes and uncertain long-term survivorship. The aim of this study is to establish long-term functional outcomes, radiographic results, and survivorship after revision TKA with a rotating hinge implant. MethodThis is a retrospective study of prospectively collected data of 41 consecutive patients undergoing revision TKA with rotating hinge components and minimum 10-years follow-up. The study included 22 females (53.7%) and 19 males (46.3%) with a mean age of 66.6 ± 8.5 years. Clinical outcomes recorded included the Oxford Knee Score (OKS) preoperatively and at latest follow-up. Range of motion, implant survivorship, and complications were also recorded. Predefined radiological outcomes were obtained using plain radiographs. ResultsThere was a significant improvement in OKS after revision TKA with a rotating hinge implant compared to preoperative scores (40.7 ± 4.2 vs. 21.4 ± 4.9 respectively, p < 0.001). At latest follow-up, mean range of motion was 111.5° ± 9.3° and mean overall limb alignment was 0.2° ± 2.0° varus. Implant survivorship at minimum 10-year follow-up was 90.2%. Radiographic lucent lines were observed in 14 patients (34.1%). ConclusionRevision TKA with a rotating hinge implant leads to satisfactory clinical outcomes and very good implant survivorship at long-term follow-up. Surgeons should have a low threshold to use these versatile implants in complex revision knee arthroplasty.

Implant Interface Debonding After Total Knee Arthroplasty: A New Cause for Concern?

BackgroundAseptic loosening has long been an associated etiology for revision total knee arthroplasty (TKA). MethodsThis case series investigates commonalities between 9 patients who underwent revision TKA and were found to have complete debonding at the cement-implant interface of a femoral and/or tibial component within the past 2 years. ResultsOnly 3 preoperative radiographs were indicative of aseptic loosening, and all patients had an infectious etiology ruled out. ConclusionsThis case series and other similar reports suggest that there may be a growing concern for debonding as a modern form of aseptic loosening. Further research through American Joint Replacement Registry and other national databases will need to be conducted to better understand if this is truly a new cause for concern after TKA and how it may be best prevented.

Mid-term lifetime survivals of octogenarians following primary and revision total knee arthroplasties were satisfactory: a retrospective single center study in contemporary period

BackgroundAs life expectancy increases, the number of octogenarians requiring primary and revision total knee arthroplasty (TKA) is increasing. Recently, primary TKA has become a common treatment option in octogenarians. However, surgeons may still be hesitant about performing revision TKA on octogenarians because of concern about risk and cost benefit. The purpose of this study was to investigate clinical outcomes, postoperative complications, and mid-term lifetime survival in octogenarians after primary and revision TKA.Materials and methodsWe retrospectively reviewed 231 primary TKAs and 41 revision TKAs performed on octogenarians between 2000 and 2016. The mean age of patients undergoing primary TKA was 81.9 years and that of patients undergoing revision TKA was 82.3 years (p = 0.310). The age-adjusted Charlson comorbidity index was higher in revision TKA (4.4 vs. 4.8, p = 0.003). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and range of motion (ROM) were evaluated. The incidence of postoperative complications (TKA-related, specific or systemic) and lifetime survival rate (endpoint death determined by telephone or mail communication with patient or family) were investigated.ResultsThe WOMAC and ROM improved significantly after primary and revision TKA, although postoperative results were worse in the revision group (33.1 vs. 47.2; 128.9° vs. 113.6°; p < 0.001, respectively). There were no cases of aseptic or septic component failure in either group. One case of periprosthetic fracture was observed in the revision group (0% vs. 2.4%, p = 0.151), and three cases of deep vein thrombosis (DVT)/pulmonary thromboembolism (PTE) (one case of DVT and two cases of PTE) were observed in the primary group (1.3% vs. 0%, p = 1.000). The most common systemic complication in both groups was delirium (7.4% vs. 14.6%, p = 0.131). There were no differences between the two groups in the other systemic complication rates. The 5-year and 10-year lifetime survival rates were 87.2% and 62.9%, respectively, in primary TKA and 82.1% and 42.2%, respectively, in revision TKA (p = 0.017).ConclusionsBoth primary and revision TKA are viable options for octogenarians, based on the satisfactory clinical outcomes, TKA-related complication rates, and mid-term lifetime survival. Delirium needs to be managed appropriately as the most common systemic complication in both primary and revision TKA in octogenarians.Level of evidenceIV

Outcome of Revision Surgery for the Idiopathic Stiff Total Knee Arthroplasty

BackgroundIdiopathic stiff total knee arthroplasty (TKA) represents one of the most challenging subsets of the stiff TKA, as the etiology is unknown and there is no consensus on the most appropriate surgical treatment modality. Therefore, the aim of this study is to report on postoperative outcomes of revision surgery for idiopathic stiff TKA. MethodsWe retrospectively reviewed 189 consecutive patients (202 knees) who underwent revision TKA for stiffness: (1) 101 knees in the idiopathic stiffness cohort and (2) 88 in the non-idiopathic stiffness cohort. In the idiopathic stiffness cohort, 42 knees underwent isolated tibial insert exchange and 59 knees underwent component revision. Perioperative knee range of movement and complications were analyzed. ResultsThe overall revision surgery outcomes of the idiopathic stiffness cohort were worse than those of the non-idiopathic stiffness cohort with regard to maximum flexion (91.7° vs 100.1°, P = .02) and flexion range of motion (ROM) (87.6° vs 97.1°, P = .01). In the idiopathic stiffness cohort, isolated tibial insert exchange demonstrated greater maximum flexion (96.8° vs 88.4°, P = .06) and flexion ROM (93.2° vs 83.9°, P = .07). In terms of re-revision rates, the isolated tibial insert exchange idiopathic stiffness cohort demonstrated lower re-revision rates compared to the component revision idiopathic stiffness cohort (16.7% vs 31.0%, P = .01). ConclusionThis study demonstrates that the overall revision surgery outcome of idiopathic stiff TKA is worse than non-idiopathic TKA stiffness. In idiopathic stiffness cohorts, isolated tibial insert exchange was associated with lower re-revision rates than component revision, with similar efficacy in improving ROM, suggesting that isolated tibial insert exchange may be a preferred surgical treatment option in TKA patients with idiopathic stiffness.