Conversion Total Knee Arthroplasty Research Articles

Conversion Total Knee Arthroplasty After Failed Osteochondral Allograft Reconstruction: Similar Functional Performance With Lower Patient Satisfaction

BackgroundThis study presents surgical techniques used in conversion total knee arthroplasty (cTKA) following early failure of large osteochondral allograft joint replacement and compares postoperative patient reported outcomes measures (PROMs) and satisfaction scores with a contemporary primary total knee arthroplasty (pTKA) cohort. MethodsWe retrospectively evaluated 25 consecutive cTKA patients (26 procedures) to define the utilized surgical techniques, radiographic disease severity, preoperative and postoperative PROMs (visual analog scale [VAS] pain, knee injury and osteoarthritis outcome score for joint replacement [KOOS-JR], University of California Los Angeles Activity), expected improvement and postoperative satisfaction (5-point Likert), and reoperations in comparison with an age and body mass index propensity matched cohort of 50 pTKA performed for osteoarthritis (52 procedures). ResultsRevision components were used in 12 cTKA cases (46.1%), with 4 cases requiring augmentation (15.4%), and 3 cases utilizing varus-valgus constraint (11.5%). While no significant differences were noted in expectation level or in other PROMs, mean patient reported satisfaction was lower in the conversion group (4.4 ± 1.1 versus 4.8 ± 0.5 points, P = .02). High cTKA satisfaction was associated with a higher postoperative KOOS-JR (84.4 versus 64.2 points, P = .01) and a trend towards higher University of California Los Angeles activity (6.9 versus 5.7 points, P = .08). Four patients in each group underwent manipulation (15.3 versus 7.6%, P = .42), and 1 pTKA patient was treated for early postoperative infection (0 versus 1.9%, P = 1.0). ConclusioncTKA following failed biological replacement was associated with similar postoperative improvement as in pTKA. Lower patient-reported cTKA satisfaction was associated with lower postoperative KOOS-JR scores.

Complications, Implant Survivorships, and Functional Outcomes of Conversion Total Knee Arthroplasty With Prior Hardware

BackgroundEnd-stage knee osteoarthritis with retained periarticular hardware is a frequent scenario. Conversion total knee arthroplasty (TKA) leads to excellent outcomes, but poses unique challenges. The evidence supporting retention versus removal of hardware during TKA is controversial. MethodsPatients who underwent TKA with prior hardware between January 2009 and December 2019 were identified. A total of 148 patients underwent TKA with prior hardware. The mean follow-up was 60 months (range, 24-223). Univariate and multivariable analyses were used to study correlations among factors and surgical-related complications, prosthesis failures, and functional outcomes. ResultsThe complication rate was 28 of 148 (18.9%). The use of a quadriceps snips in addition to a medial parapatellar arthrotomy was associated with a higher complication (odds ratio: 20.7, P < .05), implant failures (odds ratio: 13.9, P < .05), and lower the Veterans Rand 12 Mental Score (VR-12 MS) (−14.8, P < .05). Hardware removal versus retention and use of single versus multiple incisions were not associated with complications or prosthesis failures. Removal of all hardware was associated with significantly higher (+7.3, P < .05) VR-12 MS compared to retention of all hardware. ConclusionsTKA with prior hardware was associated with more complications, implant failures, and lower VR-12 MS when a more constrained construct or quadriceps snip was performed. This probably reflects the level of difficulty of the procedure rather than the surgical approach used. Hardware removal or retention was not associated with complications or implant failures; however, removal rather than retention of all prior hardware is associated with increased general health outcomes. Level of evidenceIV, cohort without control.

Concurrent Hardware Removal is Associated With Increased Odds of Infection Following Conversion Total Knee Arthroplasty

BackgroundThe optimal timing of removal of periarticular implants prior to conversion total knee arthroplasty (TKA) remains to be determined. The purpose of this study was to compare infection rates in conversion TKA when hardware removal was performed in either a staged or concurrent manner. MethodsWe performed a retrospective study using a national insurance claims database of patients who underwent removal of hardware on the same day or within 1 year before their TKA. A total of 16,099 patients met the criteria. After matching, both final cohorts consisted of 4,502 patients. The 90-day and 1-year rates of prosthetic joint infection were calculated. ResultsThe rates of infection were 1.64% and 3.00% in the staged group and 2.62% and 3.95% in the concurrent group at 90 days and 1 year postoperatively, respectively (P = .001, P = .01). Logistic regression analyses demonstrated that patients who had hardware removal greater than 3 months prior to TKA had significantly lower odds of infection at 1-year postop (Odds Ratio 0.61 95% Confidence Interval 0.45-0.84; P = .003). ConclusionRemoval of hardware performed concurrently or within 3 months of a TKA is associated with increased odds of prosthetic joint infection at 1 year postoperatively. Surgeons should consider removing periarticular hardware prior to TKA when possible.

Same-Day Discharge Following Aseptic Revision and Conversion Total Joint Arthroplasty: A Single-Institution Experience

BackgroundWith hospital inpatient capacity increasingly limited and primary total joint arthroplasty (TJA) rapidly transitioning to outpatient settings, the feasibility of outpatient aseptic revision and conversion TJA (rTJA) has been considered. Before the widespread adoption of outpatient rTJA, guidelines must be established to prevent patient harm. To this end, this study describes our initial experience with same-day-discharge (SDD) aseptic rTJA. MethodsAll aseptic rTJAs performed between May 8, 2015, and December 30, 2021, were retrospectively reviewed. Revision indications, patient selection criteria, and outcomes including SDD success rate, predischarge complications, all-cause emergency department visits, inpatient readmissions, and unplanned clinic encounters within 90 days of surgery were recorded. ResultsThirty-five SDD aseptic rTJAs were performed. Conversion total hip arthroplasty (55.0%) and instability (27.3%) were the most common indications for hip revision. Instability (50%) and conversion total knee arthroplasty (20.8%) were most common for knee revision. SDD was achieved in 97% (34/35) of cases. One hip patient failed SDD due to persistent hypoxia requiring an overnight hospital stay and also underwent closed reduction for dislocation in the emergency department within 90 days of discharge. Two additional patients had unplanned clinic encounters within 90 days of the index procedure. There were no hospital readmissions or reoperations within 90 days. ConclusionsOur initial experience suggests SDD aseptic rTJA can be safe and effective when modern perioperative outpatient protocols and surgical techniques are implemented. Future studies should further define patient selection criteria to optimize outcomes and minimize complications in this population.

Risk Factors for Wound Complications Following Conversion TKA after Tibial Plateau Fracture.

The purpose is to investigate the incidence of wound complications for total knee arthroplasty (TKA) following tibial plateau open reduction and internal fixation (ORIF). A prospective arthroplasty registry was queried for patients with CPT codes for primary TKA, tibial plateau ORIF, removal of hardware (ROH), and diagnosis of post-traumatic arthritis. Patients were included if they had undergone tibial plateau ORIF and subsequent TKA. Chart review was performed to obtain demographic, clinical and post-operative information. Twenty-one patients were identified, with average age of 56.23 ± 13.2years at time of tibial plateau ORIF and 62.91 ± 10.8years at time of TKA. Seven (33.3%) patients had a tibial plateau fracture-related infection (FRI). Eight (38.1%) patients underwent ROH prior to TKA. Seven (33.3%) patients' TKA incision incorporated the prior plateau incisions. Eight (36.4%) patients developed wound complications following TKA and 5 (23.8%) developed an acute periprosthetic joint infection (PJI) following TKA and had the plateau incision incorporated into the TKA incision. FRI history did not increase the rate of wound complications but did increase the rate of ROH prior to TKA. Previous FRI involving tibial plateau repair surgery doesn't correlate with PJI after conversion TKA for post traumatic OA. Surgeon-controlled factors such as staged ROH and incision placement can help reduce the rate of wound complications following TKA performed after tibial plateau ORIF. Prognostic Level IV. The online version contains supplementary material available at 10.1007/s43465-022-00709-1.

Is Conversion Total Knee Arthroplasty a Distinct Surgical Procedure? A Comparison to Primary and Revision Total Knee Arthroplasty.

Conversion total knee arthroplasty (TKA) is suggested to incur similar complication rates to revision arthroplasties. However, current billing codes do not allow for the differentiation between this operation and primary TKAs. Therefore, the purpose of this study was to compare outcomes of these two surgeries, as well as revision TKAs. Specifically, we analyzed (1) medical complications, (2) surgical complications, and (3) revision rates at 90 days and 1 year. We queried a national, all-payer database to identify patients who underwent TKA without prior implants (n = 1,358,767), required conversion TKA (n = 15,378), and who underwent revision TKA (n = 33,966) between January 1, 2010, and April 30, 2020. Conversion TKA patients (prior implant removal) were identified using the Current Procedural Terminology (CPT) codes. Outcomes studied included 30-day readmission rates and 90-day, as well as 1-year, medical and surgical complications. Conversion TKAs had greater 30-day readmission rates and incidences of most of the complications studied when compared with primary TKAs. The majority of outcomes when comparing between primary, conversion, and revision TKAs were significantly different (p < 0.01). In contrast, conversion TKA complications were similar to revision TKA. Conversion TKAs have higher postoperative complications than primary TKAs and share more similarities with revision TKAs. Thus, the lack of billing codes differentiating conversion and primary TKAs creates a challenge for orthopaedic surgeons.

Conversion Total Knee Arthroplasty After Tibial Plateau Fixation Is Associated With Lower Reimbursement, Greater Complication Rates, and Similar Opioid Use.

ObjectiveTotal knee replacement after previous open reduction and internal fixation for tibial plateau fracture (conversion total knee) increases the complexity of the procedure and the complication rate. However, very little research exists to report on opioid use and cost associated with total knee arthroplasty (TKA) following tibial plateau fracture fixation as compared to primary TKA patients with no history of tibial plateau fracture. The aim of this study is to compare the differences in opioid use, reimbursements, and complication rates between patients with and without a history of tibial plateau fracture undergoing TKA.Methods and materialsThis is a retrospective large database review study. The study included patients across the country and in various clinical settings including, but not limited to, institutions, primary and tertiary care centers, and private practice. The PearlDiver database was reviewed for patients undergoing TKA between 2010 and 2019. Patients who underwent TKA following surgical repair of a tibial plateau fracture were identified using Common Procedural Terminology (CPT) codes and the appropriate International Classification of Diseases Ninth and Tenth Revision (ICD-9, ICD-10) codes. This group was then matched by age, gender, Charleston Comorbidity Index (CCI) score, Elixhauser Comorbidity Index (ECI) score, obesity, tobacco use, and diabetes to a group of similar patients who underwent TKA with no history of tibial plateau fracture. Opioid use over the episode of care, evaluated by morphine milligram equivalents (MME), and 30-day reimbursed cost were compared between groups using an unequal variance t-test. Complication rates at 30 days, 90 days, and one year postoperatively, and revision rates at one and two years postoperatively were compared using the odd’s ratio (OR) with 95% confidence intervals (95%CI).ResultsThe episode of care cost for TKA was significantly lower for patients with a history of tibial plateau fracture ($11,615 ± $15,704) than it was for patients without a history of tibial plateau fracture ($16,088 ± $18,573) (p = 3.56E-14). At 30 days after knee arthroplasty, patients with a history of tibial plateau fracture had significantly more episodes of dehiscence (OR 2.665 [95% CI 1.327-5.351]; p = 0.006) and surgical site infection (SSI) (OR 1.698 [95% CI 1.058-2.724]; p = 0.028), which was significant at 90 days postop for both dehiscence (OR 1.358 [95% CI 0.723-2.551]; p = 0.001) and SSI (OR 1.634 [95% CI 1.100-1.802]; p = 0.015), as well as mechanical complications of the implant device (OR 2.420 [95% CI 1.154-5.076]; p = 0.019). There was no significant difference in the number of opioids prescribed postoperatively to patients with a history of tibial plateau fracture (2218 ± 3255 MME) compared to those without prior tibial plateau fracture (2400 ± 4843 MME) (p = 0.258). However, there was a small but statistically significant increase in the number of days postoperatively patients with a history of tibial plateau fracture were prescribed opioids (11.99 ± 7.73 days) compared to non-tibial plateau fracture patients (11.15 ± 7.18 days) (p = 0.004).ConclusionPatients with a history of tibial plateau fracture who then underwent conversion TKA have a lower reimbursed cost of TKA but a higher postoperative risk for dehiscence, mechanical complications, and surgical site infections. There is no significant difference in postoperative opioid use between the two groups.

Conversion Total Knee Arthroplasty.

Conversion total knee arthroplasty (TKA) represents a heterogeneous group of procedures and most commonly includes TKA performed after ligamentous reconstruction, periarticular open reduction and internal fixation (ORIF), high tibial osteotomy (HTO), and unicompartmental knee arthroplasty (UKA). Relative to patients undergoing primary TKA, patients undergoing conversion TKA often have longer operative times and higher surgical complexity, which may translate into higher postoperative complication rates. There is mixed evidence on implant survivorship and patient-reported outcome measures when comparing conversion TKA and primary TKA, with some studies noting no differences between the procedures and others finding decreased survivorship and outcome scores for conversion TKA. By gaining an improved understanding of the unique challenges facing patients undergoing conversion TKA, clinicians may better set patient expectations, make intraoperative adjustments, and guide postoperative care.

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.

Increased Revisions in Conversion Total Knee Arthroplasty After Periarticular Open Reduction Internal Fixation Compared With Primary Total Knee Arthroplasty: A Matched Cohort Analysis

BackgroundPrior studies on conversion total knee arthroplasty (cTKA) have reported increased technical challenges and risk of complications compared with primary knee arthroplasty. The purpose of this study was to compare two-year postoperative complication/revision rates between patients undergoing cTKA after prior periarticular open reduction and internal fixation (ORIF) and those undergoing primary TKA. MethodsPatients who underwent cTKA after prior periarticular ORIF of the ipsilateral knee were identified in a national all-payer claims database from 2010 to 2018. This ORIF-cTKA cohort was propensity matched to participants undergoing primary TKA based on age, gender, Charlson comorbidity index, and obesity status. Univariate analysis was performed to analyze differences in two-year complication and revision rates. ResultsAfter propensity matching, 823 patients were included in the ORIF-cTKA cohort and 1640 patients in the primary TKA cohort. No differences in demographics or comorbidities existed between cohorts. Relative to the primary TKA cohort, the ORIF-cTKA cohort had significantly higher incidences of all-cause revision (5.47% vs 2.47%, P = .001), periprosthetic joint infection (PJI; 4.74% vs 1.34%, P < .001), and intraoperative or postoperative periprosthetic fracture (1.58% vs 0.55%, P = .01) at two years postoperatively. There was also a nonsignificant trend toward increased rates of aseptic loosening (1.82% vs 0.91%, P = .052) in the ORIF-cTKA. ConclusionRelative to primary TKA, cTKA after periarticular ORIF is associated with significantly increased rates of all-cause revision, PJI, and periprosthetic fracture at two years postoperatively. Surgeons should counsel these patients about the increased risks of these postoperative complications and consider treating them as high risk for PJI in the perioperative period.

Management of failed UKA to TKA: conventional versus robotic-assisted conversion technique

BackgroundFailure of unicompartmental knee arthroplasty (UKA) is a distressing and technically challenging complication. Conventional conversion techniques (CCT) with rods and jigs have produced varying results. A robotic-assisted conversion technique (RCT) is an unexplored, though possibly advantageous, alternative. We compare our reconstructive outcomes between conventional and robotic methods in the management of failed UKA.MethodsThirty-four patients with a failed UKA were retrospectively reviewed. Patients underwent conversion total knee arthroplasty (TKA) with either a CCT or RCT. Seventeen patients were included in each group. All procedures were done by a single surgeon at a single institution, with a mean time to follow-up of 3.6 years (range, 1 to 12). The primary outcome measures were the need for augments and polyethylene thickness. Secondary outcome measures were complications, need for revision, estimated blood loss (EBL), length of stay, and operative time.ResultsThe mean polyethylene thickness was 12 mm (range, 9 to 15) in the CCT group and 10 mm (range, 9 to 14) in the RCT groups, with no statistical difference between the two groups (P = 0.07). A statistically significant difference, however, was present in the use of augments. In the CCT group, five out of 17 knees required augments, whereas none of the 17 knees in the RCT group required augments (P = 0.04). Procedurally, robotic-assisted surgery progressed uneventfully, even with metal artifact noted on the preoperative computerized tomography (CT) scans. Computer mapping of the residual bone surface after implant removal was a helpful guide in minimizing resection depth. No further revisions or reoperations were performed in either group.ConclusionsRobotic-assisted conversion TKA is technically feasible and potentially advantageous. In the absence of normal anatomic landmarks to guide conventional methods, the preoperative CT scans were unexpectedly helpful in establishing mechanical alignment and resection depth. In this limited series, RCT does not seem to be inferior to CCT. Further investigation of outcomes is warranted.

Staged vs Concurrent Hardware Removal During Conversion Total Knee Arthroplasty

BackgroundConversion total knee arthroplasty (TKA) in the presence of periarticular hardware can be associated with increased resource utilization, complications, and revisions. However, little guidance exists on the optimal approach to hardware removal. The purpose of this study is to compare outcomes of conversion TKA with hardware removal performed in either a staged or concurrent manner. MethodsThis is a retrospective study of 155 TKA operations performed with staged (45) or concurrent (110) removal of hardware at the time of TKA. Differences in patient data, case data, complications, reoperations, and revisions were evaluated. Subgroup comparisons of cases involving major hardware (plates, nails, rods), minor hardware (screws, buttons, wires), and tibial plates were performed. ResultsThere were no differences in age, sex, body mass index, or comorbidities between patients who underwent staged or concurrent hardware removal. Rates of complications, reoperations, and revisions did not differ at multiple time points (90 days, 1 year, 2 years, 4 years). Patients who underwent staged hardware removal were more likely to have had prior surgery for fracture reconstruction (68% vs 33%, P < .001), to have had major hardware removed (84% vs 59%, P = .03), and were less likely to have had hardware removal performed through a single incision with TKA (50% vs 92%, P < .001). Subgroup analysis of major and minor hardware cases demonstrated comparable outcomes. ConclusionThere remains no established benefit to either a staged or concurrent approach to hardware removal at the time of TKA. This is true regardless of hardware burden. At this time, a case-by-case approach should be taken to conversion TKA in the presence of periarticular hardware.

Conversion Total Knee Arthroplasty: Prior Fracture or Osteotomy Around the Knee Leads to Increased Resource Utilization

BackgroundPrior knee surgery before total knee arthroplasty (TKA) puts patients at higher risk of inferior outcomes and increased care cost. This study compares intraoperative and postoperative variables including procedure duration, components, length of stay, readmission, complications, and reoperations among patients undergoing conversion TKA. MethodsPrimary TKA from a single-surgeon database identified 130 patients with prior knee surgery to form a “conversion” cohort. One-to-one matching identified 130 patients of similar age, American Society of Anesthesiologists score, body mass index, and gender without prior knee surgery for comparison. Perioperative and 90-day postoperative variables were compared between patients with and without prior surgery, within the conversion group based on the type of prior surgery, and whether the prior surgery was bony or soft tissue. ResultsThe conversion group had longer mean operative time (96.1 vs 90.0 minutes, P = .01), higher revision component utilization (8.5% vs 0.8%, P = .005), and higher calculated blood loss (1440 vs 1249 mL, P = .004). Thirty-eight patients with prior fracture or osteotomy were compared to the remaining 92 patients in the conversion group and showed longer operative time (107.1 vs 91.3 minutes, P < .001), higher 90-day readmissions (18.4% vs 3.3%, P = .003), more complications (23.7% vs 8.7%, P = .021), and greater utilization of revision components (26.3% vs 1.1%, P < .001). ConclusionPatients undergoing conversion TKA required increased resource utilization, particularly patients with a prior osteotomy or fracture. Policymakers should consider these variables, as they did in conversion THA, in adding a code to account for increased case complexity and resource utilization.

Conversion Total Knee Arthroplasty is Associated with Increased Post-Acute Care Costs

BackgroundAlternative payment models have been viewed as successfully decreasing costs following primary total knee arthroplasty (TKA) while maintaining quality. Concerns exist regarding access to care for patients who may utilize more resources in a bundled payment arrangement. The purpose of this study is to determine if patients undergoing conversion of prior surgery to TKA have increased costs compared to primary TKA patients. MethodsClaims from Medicare and a single private insurer were queried for all primary TKA patients at our institution from 2015 to 2016. Ninety-day post-acute care costs were compared between primary and conversion TKA. Secondary endpoints included discharge disposition, complications, and readmissions. A multivariate regression analysis was performed to identify independent risk factors for increased post-acute care costs and short-term outcome metrics. ResultsOf 3999 primary TKA procedures, 948 patients (23%) underwent conversion TKA. Conversion TKA was associated with greater post-acute care costs in patients with commercial insurance ($4714 vs $3759, P = .034). Among Medicare beneficiaries, prior ligament reconstruction was associated with increased post-acute care costs ($1917 increase, P = .036), while prior fracture fixation approached statistical significance ($2402 increase, P = .055). Conversion TKA was an independent risk factor for readmissions (odds ratio 1.46, 95% confidence interval 1.00-2.17, P = .050), while patients with a prior open knee procedure had higher rates of complications (odds ratio 2.41, 95% confidence interval 1.004-5.778, P = .049). ConclusionOur data suggest that conversion from prior knee surgery to TKA is associated with increased 90-day post-acute care costs and resource utilization, particularly prior open procedures. Without appropriate risk adjustment in alternative payment models, surgeons may be financially deterred from providing quality arthroplasty care given the reduced net payment and surgical complexity of such cases.

Conversion Total Knee Arthroplasty Needs Its Own Diagnosis-Related Group Code

BackgroundConversion from a prior knee procedure has been demonstrated to require greater operative times and resources, but still lacks a separate procedural or facility code from primary total knee arthroplasty (TKA). The purpose of this study is to determine differences in facility costs between patients who underwent primary TKA and those who underwent conversion TKA. MethodsWe retrospectively reviewed a consecutive series of patients undergoing primary TKA at 2 hospitals from 2015 to 2017, comparing itemized facility costs between primary and conversion TKA patients. A multivariate regression analysis was performed to identify independent risk factors for increased facility costs, the need for additional implants, length of stay, and discharge disposition. ResultsOf 2447 TKA procedures, 678 (27.7%) underwent conversion TKA, which was associated with greater implant costs ($3931.47 vs $2864.67, P = .0120) and total facility costs in a multivariate regression ($94.30 increase, P = .0316). When controlling for confounding variables, patients with a prior ligament reconstruction ($402 increase, P = .0002) and prior open reduction and internal fixation ($847 increase, P = .0020) had higher costs and were more likely to require stemmed implants (P < .05). There was an increase in TKA implant cost by $538 in patients with implants from a prior procedure (P < .0001). ConclusionConversion TKA is associated with greater implant and inpatient facility costs than primary TKA, particularly those who had a history of an open knee procedure. A separate diagnosis-related group should be created for conversion TKA given the increased cost and complexity of these procedures compared to primary TKA.

Antibiotic-impregnated articulating cement spacer maintained for 7 years in situ for two-stage primary total knee arthroplasty: a case report

BackgroundAntibiotic-impregnated articulating cement spacers can maintain interim joint motion with the potential to enhance functional status and improve patient satisfaction. Articular surfaces with cement against cement have raised concerns regarding mechanical complications and cement debris during knee motion. However, long-term clinical conditions regarding these concerns are not well addressed.Case presentationWe report a case in which articulating cement spacers were maintained in situ for 7 years. The patient had severe left knee pain with an ankylosing knee and severe tricompartmental arthritis due to tuberculous infection. We planned to perform one- or two-stage primary total knee arthroplasty (TKA), depending on the presence of infection. Persistent osteomyelitis was found intraoperatively. The second-stage TKA was delayed on the patient’s request. As the patient was satisfied with the improved knee function and pain relief after using articulating cement spacers. No symptom or sign that suggested recurrent infection or systemic toxicity was found during the 7-year follow-up. However, it seemed that the bone loss progressed insidiously. At the 7-year follow-up, a broken articulating cement spacer and medial femoral condylar fracture were found. The second-stage TKA was performed, and a considerable amount of bone loss surrounded by dense granulation tissue was observed intraoperatively. Excisional biopsy of the tissue revealed chronic foreign body reaction with infiltration of giant cells and macrophages.ConclusionAlthough the articular spacers were maintained for 7 years without major complications, regular observation of the development and progress of bone loss was required. Surgeons should take considerable bone loss into account during conversion TKA in patients with a prolonged retention of articulating cement spacers.

Conversion Total Knee Arthroplasty: A Distinct Surgical Procedure With Increased Resource Utilization

BackgroundCurrent Procedural Terminology coding currently makes no distinction between primary total knee arthroplasty (TKA) and conversion TKA, in which periarticular hardware components must be removed prior to or during TKA. We hypothesize that conversion TKA will carry increased operative time, blood loss, postoperative complications, and 90-day emergency department/readmission rate compared to primary TKA. MethodsPatients undergoing conversion TKA from 2005 to 2017 were identified from an institutional database and matched to primary TKA patients by age, gender, American Society of Anesthesiologists score, body mass index, and procedure date (±1 year). Intraoperative data and 90-day postoperative complications were compared between groups. ResultsOne hundred nine conversion TKA patients with periarticular hardware were removed prior to (n = 51) or during (n = 58) TKA and 109 primary TKA control patients were included. Conversion TKA was associated with increased tourniquet time (91 vs 71 minutes, P < .001), operative time (147 vs 113 minutes, P < .001), blood loss (225 vs 176 mL, P = .010), 90-day readmissions (14.6% vs 4.2%, P = .020), wound complication (5.6% vs 0.0%, P = .025), periprosthetic joint infection (7.9% vs 0.0%, P = .005), irrigation/debridement (9.0% vs 1.1%, P = .016), and a trend toward increased mechanical complication (6.7% vs 1.1%, P = .058). Timing of hardware removal did not affect intraoperative or postoperative outcomes. ConclusionConversion TKA is associated with higher operative time, blood loss, readmission rate, and postoperative complications compared to primary TKA. Without a proper billing code and appropriate reimbursement level to match the expected operative and postacute resource utilization by these cases, physicians may be disincentivized to perform these operations.

Conversion total knee arthroplasty after arthrodesis using rotatory hinge revision system

Objective Patients with knee arthrodesis experience many daily activities and limitations affecting their life quality. The purpose of this study was to report and discuss the outcome of our cases of knee arthrodesis converted to total knee arthroplasty. Patients and methods In the period from August 2015 to December 2017, the authors conducted a prospective study that included six patients (one female and five males) with sound knee arthrodesis. All patients underwent conversion total knee arthroplasty using rotatory hinge revision system. Patients’ ages ranged from 35 to 66 years. Patients were evaluated using Knee Society Clinical Score and Knee Injury and Osteoarthritis Outcome Score. Results The average follow-up period was 24.5 months (18–36 months). At the final follow-up, average knee flexion was 87.5° (70°–100°). Knee Society Clinical Score and Knee Injury and Osteoarthritis Outcome Score score increased form an average of 31.8 (28.4–34.8) preoperatively to 66.6 (58.6–74.4) at the final follow-up. The authors had an average final Knee society score of 67.6, ranging from 53 to 78. Three cases experienced postoperative complications, representing 50% of the study group, two cases had superficial wound infection, and a case had skin edge necrosis; all were successfully managed, with no long-term complications. Conclusion Conversion total knee arthroplasty is a hope for patients who cannot tolerate the effect of knee arthrodesis in their lives. Awareness of the risks, proper patient selection, good preoperative planning, and adequate management of complications can help the patients to have satisfactory results.

Periprosthetic Fracture following Partial Knee Arthroplasty.

Partial knee arthroplasty is a procedure with long-term successful outcomes. However, there are several potential complications including retained cement fragments, bearing dislocation, infection, component loosening, medial collateral ligament injury, and overcorrection, leading to progressive arthritis. Periprosthetic fracture is an uncommon complication, with multiple reports showing an incidence of less than 1%. Hence, there are no established algorithms to guide treatment. A consecutive series of 2,464 patients who underwent partial knee arthroplasty between January 2009 and April 2017 was reviewed. We identified 16 patients with early periprosthetic fracture, with an incidence of 0.6%. All of these were tibial fractures, which occurred at a mean of 35 days postoperatively. There were 5 males and 11 females, with an average age of 70 years at the time of surgery. Average follow-up was 62 months. Two patients had contralateral compartment insufficiency fractures that were successfully treated nonoperatively, five patients immediately underwent total knee arthroplasty (TKA), and nine patients underwent open reduction internal fixation (ORIF). Two of these cases had a failed ORIF and required conversion to TKA. Seven patients were successfully treated with a medial buttress plate in compression. Average Knee Society Score at final follow-up was 81, and average flexion was 115 degrees, with no patients having greater than 5-degree flexion contracture. Periprosthetic fracture following partial knee arthroplasty resulted in a high rate of conversion TKA. However, ORIF in select patients resulted in fracture healing and retention of the partial knee replacement. All patients were successfully treated with low complication rates, excellent range of motion, and acceptable knee scores at final follow-up.

Similar Outcome, but Different Surgical Requirement in Conversion Total Knee Arthroplasty following High Tibial Osteotomy and Unicompartmental Knee Arthroplasty: A Meta-Analysis.

The present systematic review and meta-analysis were conducted to find out how effective any subsequent conversion total knee arthroplasty (TKA) would be after unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) and which is better in outcomes. A rigorous and systematic approach was used. Each of the selected studies was evaluated for methodological quality. Data were extracted by the following standardized protocol: study design, level of evidence, cases enrolled, age, sex ratio, follow-up, kind of index surgery, type of index surgery, average time to failure, mode of failure, surgical data, preclinical score, post-clinical score, and major related complications. Nineteen articles were included in the final analysis. In conversion TKA following UKA, revision components (metal augment, bone graft, and stem) were frequently used, and thicker polyethylene was used comparing to the primary TKA. In the conversion TKA following HTO, only stem was more common (relative risk of revision component UKA:HTO = 0.57:0.07). The estimated range of motions (ROM) of conversion TKA following HTO and UKA was 107.75° (101.93-113.58°) and 111.84° (108.41-115.26°), respectively (p > 0.05). The knee scores of conversion TKA following HTO and UKA were 89.10 (86.45, 91.75) and 85.48 (79.82, 91.14), respectively (p > 0.05). The function scores were 78.60 (72.44, 84.76) and 75.60 (69.85, 81.35), respectively (p > 0.05). Clinical outcome was similar between conversion TKA following HTO and UKA. However, conversion TKA after UKA required more revision components and thicker polyethylene, while conversion TKA after HTO sometimes required a stem to bypass the osteotomy gap.