Risk of Subsequent Joint Arthroplasty in Contralateral or Different Joint After Index Shoulder, Hip, or Knee Arthroplasty: Association with Index Joint, Demographics, and Patient-Specific Factors

Multiple Joint Arthroplasty in Hip and Knee Osteoarthritis Patients: A National Longitudinal Cohort Study

BACKGROUND

Many patients suffer from osteoarthritis (OA) in multiple joints, possibly resulting in multiple joint arthroplasties (MJAs). Primarily, we determined the cumulative incidence (Cin) of MJA in hip and knee joints up to 10 years. Secondly, we calculated the mean time between the first and subsequent joint arthroplasty, and evaluated the different MJA trajectories. Lastly, we compared patient characteristics and outcomes (functionality and pain) after surgery between MJA patients and single hip arthroplasty or knee arthroplasty (HA and KA) patients.

METHODS

Primary index (first) HA or KA for OA were extracted from the Dutch Arthroplasty Register. The 1, 2, 5, and 10-year Cin (including competing risk death) of MJA, mean time intervals, and MJA-trajectories were calculated and stratified for primary index HA or KA. Sex, preoperative age, and body mass index were compared using ordinal logistic regression. Outcomes, measured preoperatively, 3, 6, and 12 months postoperatively (function: Hip Disability or Knee Injury and OA Outcome Score; Pain: Numerical Rating Scale), were compared using linear regression.

RESULTS

A total of 140,406 HA-patients and 140,268 KA-patients were included. One, 2, 5, and 10-year Cin for a second arthroplasty were respectively 8.9% [95% confidence interval (CI): 8.7 to 9.0], 14.3% [95% CI: 14.1 to 14.5], 24.0% [95% CI: 23.7 to 24.2], and 32.7% [95% CI: 32.2 to 33.1] after index HA, and 9.5% [95% CI: 9.4 to 9.7], 16.0% [95% CI: 15.9 to 16.2], 26.4% [95% CI: 26.1 to 26.6], and 35.8% [95% CI: 35.4 to 36.3] after index KA. The 10-year Cin for > 2 arthroplasties were small in both the index HA and KA groups. Time-intervals from first to second, third, and fourth arthroplasty were 26 [95% CI: 26.1 to 26.7], 47 [95% CI: 46.4 to 48.4], and 58 [95% CI: 55.4 to 61.1] months after index HA, and 26 [95% CI: 25.9 to 26.3], 52 [95% CI: 50.8 to 52.7], and 61 [95% CI: 58.3 to 63.4] months after index KA. There were 83% of the second arthroplasties placed in the contralateral cognate joint (ie, knee or hip). Differences in postoperative functionality and pain between MJAs and single HAs and KAs were small.

CONCLUSIONS

The 10-year Cin showed that about one-third of patients received a second arthroplasty after approximately 2 years, with the majority in the contralateral cognate joint. Few patients received > 2 arthroplasties within 10 years. Being a women, having a higher body mass index, and being younger increased the odds of MJA. Postoperative outcomes were slightly negatively affected by MJA.

Joint replacement risk is markedly increased in alkaptonuria (AKU) in those with prior arthroplasty

Background

Increased homogentisic acid (HGA) in alkaptonuria (AKU) causes severe arthritis. Nitisinone reduces the production of HGA, but whether it also decreases arthroplasty was examined in 237 AKU patients.

Patients and methods

Patients attending the United Kingdom National Alkaptonuria Centre (NAC) and the Suitability of Nitisinone in Alkaptonuria 2 (SONIA 2) study were studied. Assessments included questionnaires eliciting details of arthroplasty. Nitisinone was administered from baseline, 2 mg in the NAC and 10 mg in SONIA 2. In SONIA 2, subgroups consisted of those with baseline arthroplasty on and not on nitisinone (BR + N+, BR + N-), as well as those without baseline arthroplasty on and not on nitisinone (BR-N+, BR-N-).

Results

In the SONIA2 subgroups, new joint replacement (JR) probabilities after baseline were significantly different (BR + N+, BR + N-, BR-N+, BR-N-) (χ2 = 23.3, p < 0.001); mean (SD) was 3.8 (0.1) years in BR-N-, 3.7 (0.1) years in BR-N+, 3.4 (0.3) years in BR + N-, and 3.0 (0.3) years in BR + N+. Further, the BR + N- showed more JR than the BR-N- subgroup (p < 0.01), while BR + N+ similarly showed more JR than the BR-N+ subgroup (p < 0.001).In the NAC, the BR- group had a mean age of 51.6 (7.0) years at baseline but 57.7 (8.7) years at final follow up during nitisinone therapy and showed only 7 incident JR. The BR+ group had an age at baseline of 57.4 (8.5) years and had undergone 94 JRs at baseline.

Conclusion

The incidence of arthroplasty was earlier and more frequent after the first JR and was not affected by nitisinone.

Performing Revision Arthroplasty Increases Surgeon and Practice Volumes Through the Generation of Subsequent Cases: A Retrospective Study

Background

Revision total knee (TKR) and hip (THR) arthroplasty surgeries are disincentivized due to unfavorable reimbursement rates, surgical times, and complication rates. Our study investigates secondary benefits of performing these surgeries by generating subsequent cases for surgeons and practices.

Methods

Patients undergoing TKR and THR between April 1, 2011, and January 1, 2019, at our tertiary academic institution were analyzed. Patients were identified with Current Procedural Terminology codes for TKR and THR. We calculated a subsequent surgery rate on the same or different joint by the initial surgeon or another surgeon within the practice to determine the procedure yield after initial revision arthroplasty.

Results

One thousand six hundred twenty-five patients met inclusion criteria. Six hundred forty-nine (39.9%) patients received at least one subsequent procedure on any joint by any orthopaedic surgeon in the practice. Four hundred five patients (24.9%) underwent another procedure on any joint by the same surgeon. Two hundred sixty patients (16.0%) underwent another procedure on the same joint by the same surgeon, with 109 cases (41.9%) being a planned second stage of a 2-stage revision for infection. Two hundred eighty-five patients (17.5%) underwent another procedure on a different joint by the same surgeon, with 122 of these patients (42.8%) undergoing at least one primary total hip or knee arthroplasty.

Conclusions

TKRs and THRs can increase surgeon and practice volumes through the generation of future cases, which are primarily the second stage of a 2-stage revision or primary joint arthroplasties on other joints.

Early outcomes after first reverse total shoulder arthroplasty better prognosticate contralateral success compared with early outcomes after anatomic total shoulder arthroplasty

BACKGROUND

The ideal timing between bilateral total shoulder arthroplasty (TSA) is unclear. The purpose of this study is to determine whether early outcomes after first TSA can be used to predict clinical outcomes after TSA of the contralateral shoulder and to evaluate the ideal time after TSA to perform the contralateral shoulder.

METHODS

A single-institution prospectively collected shoulder arthroplasty database was reviewed. Patients who underwent bilateral primary anatomic or reverse TSA (aTSA + rTSA) without an indication of fracture, tumor, or infection were identified. Included patients had minimum 2-year follow-up on their second TSA and postoperative follow-up after their first TSA at 3 months, 6 months, 1 year, or 2 years. Our primary outcome was whether outcome scores and motion at 3-month, 6-month, 1-year, and 2-year follow-up after first TSA predicted clinical success after second TSA at final follow-up, defined as achieving the patient acceptable symptomatic state (PASS = the highest level of symptoms beyond which patients consider themselves well). Outcomes included the American Shoulder and Elbow Surgeons and Constant scores, abduction, forward elevation, and external/internal-rotation. Multivariable logistic regression determined whether postoperative outcomes after first TSA were predictive of achieving the PASS after second TSA independent of age, sex, and body mass index. Receiver operating characteristic analysis determined cutoffs of postoperative outcomes after first TSA at each time point that best predicted achieving the prosthesis-specific PASS after second TSA.

RESULTS

One hundred thirty-four patients were included in the final analysis (110 aTSA and 158 rTSA). Range of motion and outcome scores at late (1- or 2-year) follow-up after first aTSA were more predictive of achieving the second TSA PASS compared with early (3- or 6-month) outcomes. In contrast, outcomes after early and late follow-up after first rTSA were similarly predictive of achieving the second TSA PASS. Specifically, the Constant score threshold at 2 years after first aTSA (79.4; area under the curve [AUC] = 0.804) better differentiated achieving the second TSA PASS vs. the 6-month threshold (72.0; AUC = 0.600). In contrast, the Constant score threshold at 2 years after first rTSA (76.4; AUC = 0.703) was similarly discriminant of achieving the second TSA PASS compared with the 6-month threshold (65.8; AUC = 0.711).

CONCLUSIONS

Patients with good outcomes after first rTSA can be counseled on contralateral TSA as early as 3 months postoperatively with confidence of a similar result on the contralateral side. In contrast, success after first aTSA does not reliably predict contralateral success until ≥1 year.

No Difference in 30-day Mortality Between Patients Undergoing Bilateral Simultaneous Total Knee Arthroplasty With Technology Assistance Compared to Conventional Instrumentation

Background: Bilateral simultaneous total knee arthroplasty (BSTKA) has decreased in frequency due to concerns about higher rates of early mortality and complications than unilateral or staged surgeries. Purpose: We sought to evaluate whether technology assistance (encompassing robotics and computer assistance) decreases early mortality following BSTKA. Methods: We conducted a retrospective cohort study using a national all-payer claims database. Patients who underwent BSTKA from October 2015 to December 2020 were identified. Univariate and multivariable analyses were conducted to compare outcomes in patients who underwent BSTKA with technology assistance compared to conventional instrumentation. The primary outcome was 30-day postoperative mortality. Secondary outcomes were respiratory failure and fat embolism. A post-hoc analysis was performed to evaluate length of stay, readmission, and other medical complications. Results: A total of 14,870 patients who underwent BSTKA were included in this study. Of these, 860 patients underwent technology-assisted BSTKA, and 14,010 patients underwent BSTKA without technology assistance. After a multivariable analysis, patients who underwent technology-assisted BSTKA had equivalent odds of 30-day mortality compared to those who underwent BSTKA without technology assistance. Technology assistance was not protective against the development of acute respiratory failure or fat embolism. Conclusion: This retrospective cohort study found no differences in the rates of 30-day mortality, respiratory failure, or fat embolism after technology-assisted BSTKA compared to conventional BSTKA. On the post-hoc analysis, technology use was associated with a decreased length of stay, lower readmission risk, and decreased rates of deep vein thrombosis, pulmonary embolism, and blood transfusion.

Risk factors for contralateral total knee arthroplasty after unilateral total knee arthroplasty

BACKGROUND

Little attention has been focused on risk factors for undergoing bilateral total knee arthroplasty (TKA) after primary unilateral TKA among patients with knee osteoarthritis (OA). This study investigated the differences in characteristics between groups with and without additional TKA for the contralateral knee among patients with knee OA who underwent primary unilateral TKA.

METHODS

Seventy-six patients who underwent primary unilateral TKA were included in this study. We defined patients who underwent additional TKA for the contralateral knee within one year of the primary TKA as a bilateral TKA group, and patients who did not undergo bilateral TKA as a unilateral TKA group. Femorotibial angle (FTA), percentage of mechanical axis (%MA), Kellgren-Lawrence (KL) grade, range of motion, Japan Orthopaedic Association (JOA) score, 10 m-walking time, C-reactive protein, estimated glomerular filtration rate, and serum albumin levels were selected as independent variables including covariates of age, sex, and body mass index for predicting bilateral TKA. We compared differences in variables between the two groups using the t-test or Mann-Whitney U-test and general linear models. A multivariate stepwise logistic regression model was also used to determine which variables correlated with bailateral TKA.

RESULTS

In pairwise comparisons, the KL grade, FTA, %MA, JOA score, and knee flexion angle in the contralateral knee were significantly worse in the bilateral TKA group than in the unilateral TKA group after controlling for covariates (P < 0.01, respectively). A stepwise logistic regression revealed that significant contributors to undergoing the contralateral TKA were FTA (OR = 1.47, P < 0.001) and knee flexion angle (OR = 0.96, P = 0.022) of the contralateral knee.

CONCLUSIONS

Severe varus deformity and limitations of flexion in the contralateral knee were found to be risk factors for undergoing additional TKA within one year of primary unilateral TKA among patients with knee OA.

Does Aseptic Revision Risk Differ for Primary Total Knee Arthroplasty Patients Who Have and Do not Have a Prior Primary or Revision Arthroplasty?

BACKGROUND

We sought to evaluate the risk of aseptic revision in total knee arthroplasty (TKA) patients who have and do not have a history of primary or revision arthroplasty of a different major joint.

METHODS

We conducted a matched cohort study using data from Kaiser Permanente's arthroplasty registries. Patients who underwent primary unilateral TKA (index knee) were identified (2009-2018). Two matches based on exposure history were performed: (1) 33,714 TKAs with a history of primary arthroplasty of a different joint (contralateral knee, either hip, and/or either shoulder) were matched to 67,121 TKAs without an arthroplasty history and (2) 597 TKAs with a history of aseptic revision in a different joint were matched to 1,190 TKAs with a history of a prior arthroplasty in a different joint, but without any revision. After the matches were performed, Cox regressions were used to evaluate aseptic revision risk of the index knee using the no history groups as the reference in regression models.

RESULTS

No difference in aseptic revision risk for the index knee was observed when comparing patients who had a prior primary arthroplasty in a different joint to those who did not have an arthroplasty history (hazard ratio = 0.95, 95% CI = 0.86-1.06). Those patients who did not have any prior aseptic revision history in a different joint had higher risk of aseptic revision in the index knee (hazard ratio = 2.06, 95% CI = 1.17-3.63).

CONCLUSION

Patients who had a prior revision history had over a 2-fold higher risk of aseptic revision in the index knee, warranting close surveillance of these patients.

LEVEL OF EVIDENCE

Level III.

Linkage Between Databases in Joint Arthroplasty and Orthopaedics: The Way Forward?

Each large observational database contains specific data elements. The number of data elements are chosen carefully to cover the essential needs of the database as well as to avoid excessive burden of collection. Frequently, an important study question cannot be answered because one database does not contain some essential data elements. This deficiency may be present because the proposed study is cross-disciplinary, because the study requires more granular information on a specific topic than is practical to collect in a broad-based registry, or because the relevant questions, and hence essential data elements, have changed over time. An obvious way to overcome some such challenges, when one database contains some of the information and another contains the further needed data, is to link different databases. While the prospect of linking databases is appealing, the practicalities of doing so often are daunting. Challenges may be practical (information-technology barriers to crosstalk between the registries), legal, and financial. In the first section of this paper, Dr. Nathanael Heckmann discusses linking large orthopaedic databases, focusing on linking databases with detailed, short-term data to those with longer-term longitudinal data. In the second part of this paper, Nathan Glusenkamp discusses efforts to link the American Joint Replacement Registry (AJRR) to other data sources, an ambition not yet fully realized but one that will bear fruit in the near future.

Total Knee Arthroplasty Assessments Should Include Strength and Performance-Based Functional Tests to Complement Range-of-Motion and Patient-Reported Outcome Measures

Range of motion (ROM) and pain often define successful recovery after total knee arthroplasty (TKA), but these routine clinical outcomes correlate poorly or not at all to functional capacity after TKA. The purpose of this Perspective is to underscore the importance of muscle strength and performance-based functional tests in addition to knee ROM and patient-reported outcome (PRO) measures to evaluate outcomes after TKA. Specifically: (1) muscle strength is the rate-limiting step for recovery of function after TKA; (2) progressive rehabilitation targeting early quadriceps muscle strengthening improves outcomes and does not compromise ROM after TKA; (3) ROM and PROs fail to fully capture functional limitations after TKA; and (4) performance-based functional tests are critical to evaluate function objectively after TKA. This Perspective also addresses studies that question the need for or benefit of physical therapy after TKA because their conclusions focus only on ROM and PRO measures. Future research is needed to determine the optimal timing, delivery, intensity, and content of physical therapy.

3D Geometric Shape Reconstruction for Revision TKA and UKA Knees Using Gaussian Process Regression

Revision knee surgery is complicated by distortion of previous components and removal of additional bone, potentially causing misalignment and inappropriate selection of implants. In this study, we reconstructed the native femoral and tibial surface shapes in simulated total/unicompartmental knee arthroplasty (TKA/UKA) for 20 femurs and 20 tibias using a statistical inference method based on Gaussian Process regression. Compared to the true geometry, the average absolute errors (mean absolute distances) in the prediction of resected femur bones in TKA, medial UKA, and lateral UKA were 1.0 ± 0.3 mm, 1.0 ± 0.3 mm, and 0.8 ± 0.2 mm, respectively, while those in the prediction of tibia resections in the corresponding surgeries were 1.0 ± 0.4 mm, 0.8 ± 0.2 mm, and 0.7 ± 0.2 mm, respectively. Furthermore, it was found that the prediction accuracy depends on the size and gender of the resected bone. For example, the prediction accuracy for UKA cuts was significantly better than that for TKA cuts (p < 0.05). The female and male cuts were often overfit and underfit, respectively. The data indicated that this reconstruction approach can be a viable option for planning of revision surgeries, especially when contralateral anatomy is pathological or cannot be available.

Impact of Smoking and Drinking on Complications After Revision Total Joint Arthroplasty: A Matched Cohort Analysis

INTRODUCTION

Smoking and drinking have been shown to impair postoperative outcomes in primary hip and knee total joint arthroplasty (TJA). This study aimed to evaluate the potential impact of smoking and drinking on complications after revision TJA.

METHODS

We retrospectively evaluated a total of 4,302 consecutive patients who underwent revision TJA. Patient demographics and complications were compared between four cohorts based on smoking and drinking status: (1) nonusers (nonsmokers and nondrinkers), (2) smokers, (3) drinkers, and (4) concurrent users.

RESULTS

A total of 1,924 patients were matched using propensity score analysis: 808 nonusers (42.0%), 421 smokers (21.9%), 483 drinkers (25.0%), and 212 concurrent users (11.1%). When compared with nonusers, smokers, drinkers, and concurrent users (simultaneous smokers and drinkers) exhibited higher odds for both inhospital complications (odds ratios, smokers: 2.40, drinkers: 1.55, and concurrent users: 5.13, P < 0.01). Among the user cohorts, although smokers and drinkers showed similar rates of 90-day postdischarge complications (smokers: 14.95% and drinkers: 14.80%, P = 0.95), concurrent users demonstrated the highest significant odds for these complications (odds ratio, 1.64, P = 0.02).

DISCUSSION

Our propensity-score-matched cohort study results demonstrate that although the smokers and drinkers groups shared similarly poor outcomes after discharge, concurrent users were found to have the worst outcomes compared with either single user group.

Robotics Versus Navigation Versus Conventional Total Hip Arthroplasty: Does the Use of Technology Yield Superior Outcomes?

BACKGROUND

The use of technology such as navigation and robotic systems may improve the accuracy of component positioning in total hip arthroplasty (THA), but its impact on patient-reported outcome measures (PROMs) remains unclear. This study aims to elucidate the association between the use of intraoperative technology and PROMs in patients who underwent primary THA.

METHODS

We retrospectively reviewed a consecutive series of patients who underwent primary THA between 2016 and 2020 and answered PROM questionnaires. Patients were separated into 3 groups depending on intraoperative technology utilization: computer-assisted navigation, robotic-assisted, or no technology (conventional) THA. Forgotten Joint Score-12 and Hip disability and Osteoarthritis Outcome Score, Joint Replacemen scores were collected at various time points. Demographic differences were assessed with chi-square and analysis of variance. Mean scores between groups were compared using univariate analysis of covariance, controlling for all significant demographic differences.

RESULTS

Of the 1960 cases identified, 896 used navigation, 135 used robotics, and 929 used no technology. There were significant statistical differences in one-year Hip disability and Osteoarthritis Outcome Score, Joint Replacement scores (85.23 vs 85.95 vs 86.76, respectively; P = .014) and two-year Forgotten Joint Score-12 scores (64.72 vs 73.35 vs 74.63, respectively; P = .004) between the 3 groups. However, these differences did not exceed the mean clinically important differences. Length of stay was statistically longest for patients who underwent conventionally performed THA versus navigation and robotics (2.22 vs 1.46 vs 1.91, respectively; P < .001). Surgical time was significantly longer for cases performed using robotics versus navigation and conventionally (119.61 vs 90.35 vs 95.35, respectively; P < .001).

CONCLUSION

Statistical differences observed between all modalities are not likely to be clinically meaningful with regard to early patient-reported outcomes. Although intraoperative use of technology may improve the accuracy of implant placement, these modalities have not yet translated into improved early reported functional outcomes.

LEVEL III EVIDENCE

Retrospective cohort.

Influence of preoperative factors on timing for bilateral shoulder arthroplasty

INTRODUCTION

In bilateral shoulder arthroplasty patients, it is unclear what features are responsible for the timing of their contralateral shoulder arthroplasty. This study hypothesized that patient factors (age, gender, and hand dominance), disease factors (diagnosis and radiographic severity of contralateral shoulder), and surgical factors (type of arthroplasty) impact the timing to contralateral surgery.

METHODS

A retrospective review of 332 patients treated with bilateral anatomic (TSA) or reverse (RSA) shoulder arthroplasty (172 TSA/TSA, 107 RSA/RSA, or 53 TSA/RSA) were divided into groups depending on the interval timing between arthroplasty surgeries: group 1, n = 142 (≤1 year); group 2, n = 62 (1-2 years); and group 3, n = 128 (≥2 years). Preoperative factors were analyzed to determine associations between different time groups, including age, gender, hand dominance, diagnosis, radiographic severity of contralateral shoulder, and type of surgery. Bilateral diagnoses included 211 osteoarthritis (OA), 36 cuff tear arthropathy (CTA), 13 inflammatory arthritis, 12 massive cuff tears without OA, and 4 avascular necrosis.

RESULTS

OA patients had their contralateral shoulder arthroplasty sooner than CTA patients (P = .035). OA patients with arthritic changes on contralateral radiographs before the first arthroplasty had their contralateral arthroplasty sooner than those without contralateral radiographs (P < .0001). Patients who had TSA first had their contralateral arthroplasty sooner than patients who had RSA first (P = .037).

DISCUSSION

This study confirmed our hypothesis identifying preoperative variables associated with different time intervals between arthroplasties. The preoperative factors associated with the highest likelihood of having contralateral shoulder arthroplasty within 1 year included OA, radiographic bilateral shoulder disease, and TSA for the first surgery.

Lower-extremity total joint arthroplasty in shoulder arthroplasty patients: does the order of the lower-extremity total joint arthroplasty matter?

BACKGROUND

As total joint arthroplasty (TJA) utilization increases, arthroplasties of multiple joints in a patient are more common. An understanding of the success of shoulder arthroplasty patients also requiring a lower-extremity (hip or knee) TJA is lacking. We evaluated the following questions: (1) Is there a difference in the revision risk following shoulder arthroplasty in patients who also undergo a lower-extremity TJA compared with those who do not? (2) Does the revision risk differ depending on the sequence of the procedures?

METHODS

Patients who underwent elective primary shoulder arthroplasty from 2009 through 2015 were identified using Kaiser Permanente's shoulder arthroplasty registry. Patients with a lower-extremity TJA were identified using the institution's total joint replacement registry. Revision related to the index shoulder was modeled via Cox regression stratified by procedure type and adjusted for confounders.

RESULTS

Of the 4751 shoulder arthroplasties identified, 1285 (27.0%) underwent a prior hip and/or knee arthroplasty and 483 (10.2%) underwent a hip and/or knee arthroplasty following the index shoulder arthroplasty. No difference was found in all-cause shoulder revision risk with lower-extremity TJA before (hazard ratio, 1.38; 95% confidence interval, 0.97-1.96) or after (hazard ratio, 1.30; 95% confidence interval, 0.82-2.06) the index shoulder arthroplasty compared with patients who underwent a shoulder arthroplasty only.

CONCLUSION

In our study sample, we did not observe shoulder revision surgery risk to be different in patients who also underwent a lower-extremity TJA, regardless of the sequence of the 2 procedures. Future prospective studies should investigate whether the timing of the lower-extremity TJA in relation to the shoulder procedure impacts the latter's success.

Complication Rates in Total Knee Arthroplasty Performed for Osteoarthritis and Post-Traumatic Arthritis: A Comparison Study

BACKGROUND

The number of total knee arthroplasty (TKA) procedures performed in the United States has been increasing. Increased complication rates have been demonstrated in patients with post-traumatic arthritis (PTA) undergoing TKA. However, there remains limited data directly comparing outcomes of TKA performed for osteoarthritis (OA) and PTA.

METHODS

The National Inpatient Sample was utilized to identify patients undergoing elective TKA between 2006 and 2015 for OA and PTA. The prevalence of preoperative comorbidities and the incidence of postoperative complications including superficial wound infection, deep joint infection, acute deep venous thrombosis, and pulmonary embolus were analyzed.

RESULTS

Between 2006 and 2015, the National Inpatient Sample database accounted for 1,301,394 patients diagnosed with either PTA (14,206) or OA (1,287,188) undergoing TKA. The incidence of superficial wound infection, deep joint infection, and acute deep venous thrombosis was found to occur at a higher rate in patients with a diagnosis of PTA compared to OA. The incidence of pulmonary embolus was not found to be statistically different between the 2 groups. Patients with PTA had a higher prevalence of drug and alcohol abuse, psychosis, and liver disease, whereas patients with OA had a higher prevalence of obesity, diabetes, heart disease, and lung disease.

CONCLUSION

This study demonstrates an increased risk of complications in patients undergoing TKA for PTA compared to OA. Surgeons can use this information to help aid in counseling patients preoperatively. Furthermore, these data provide objective evidence that could have implications with regards to establishing bundled payment reimbursement in this patient population.