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Background: Precise indications for medial unicondylar knee arthroplasty (UKA) continue to be defined. It is unclear if patients who have proximal tibia vara should be considered candidates for UKA. The purpose of this study was to evaluate the impact of proximal tibial varus alignment on outcomes after UKA., Methods: A retrospective review identified 2,416 patients (3,029 knees) who underwent mobile-bearing medial UKA with 2-year minimum follow-up or revision. Preoperative radiographs were evaluated, and medial proximal tibial angle (mPTA) was measured. Patients were grouped into two groups as follows: mPTA <80 degrees and mPTA ≥80 degrees. Analyses were performed on the impact of mPTA on clinical outcomes, all-cause revisions, and tibial failures., Results: At a mean follow-up of 5 years (range, 0.5 years to 12.8 years), there was not a statistically significant difference in clinical outcomes nor increased risk for all-cause revision or tibial failure in patients who had an mPTA <80°. Mean mPTA in patients who had tibial failures was 82.5° and not significantly different than those who did not have a tibial failure (82.9°) (P = .289). Tibial failure rate in knees with an mPTA <80° was 2.2% and not significantly different than knees with an mPTA ≥80° at 1.4% (P = .211). The all-cause revision rate in knees with an mPTA <80° was 5.8% and was not significantly different than knees with an mPTA ≥80° at 4.9% (P = .492)., Conclusion: Patients who have tibia vara are not at increased risk for tibial related or all-cause failure in medial UKA. This data may allow surgeons to increase their indications for medial UKA., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Some of today's tough questions surrounding hip and knee arthroplasty involve modifiable risks, bilateral staging, physiotherapy, postoperative activity, venous thromboembolism and infection prophylaxis, pain management, and outpatient settings. The available literature is reviewed to provide answers to difficult questions facing the orthopaedic surgeon. Preoperative questions focus on patient selection, medical optimization, and appropriateness for outpatient surgery. Modifiable risk factors for undergoing lower extremity arthroplasty include obesity, smoking, and diabetic control. Guidelines are presented to advise which patients are suitable candidates to undergo the procedure in an outpatient setting. Perioperative questions arise regarding the use of first-generation cephalosporins for prophylaxis, topical vancomycin powder, tranexamic acid, negative-pressure dressings, local intra-articular injections, and optimal timing of staged bilateral procedures. Postoperative questions are often raised about the necessity of formal postoperative physical therapy, when can patients resume driving after arthroplasty, should patients return to high-level sporting activity, and how long should patients be advised to take antibiotic prophylaxis for dental procedures.

Aims: A limited number of investigations with conflicting results have described perivascular lymphocytic infiltration (PVLI) in the setting of total knee arthroplasty (TKA). The purpose of this study was to determine if PVLI found in TKAs at the time of aseptic revision surgery was associated with worse clinical outcomes and survivorship., Methods: A retrospective review was conducted on 617 patients who underwent aseptic TKA revision who had histological analysis for PVLI at the time of surgery. Clinical and radiological data were obtained pre- and postoperatively, six weeks postoperatively, and then every year thereafter., Results: Within this cohort, 118 patients (19.1%) were found to have PVLI on histological analysis. Re-revision was performed on 83 patients (13.4%) with no significant differences in all-cause or aseptic revisions between groups. A higher incidence of PVLI was noted in female patients (p = 0.037). There was no significant difference in improvement in the range of motion (p = 0.536), or improvement of KSC (p = 0.66), KSP (p = 0.61), or KSF (p = 0.3) clinical outcome scores between PVLI and no PVLI sub-groups. There was a higher incidence of a preoperative diagnosis of pain in the PVLI group compared with patients without PVLI (p = 0.002) present., Conclusion: PVLI found on large-scale histological analysis in TKAs at aseptic revision surgery was not associated with worse clinical outcomes or rates of re-revision. Cite this article: Bone Joint J  2021;103-B(6 Supple A):145-149.

The literature is mixed on the long-term fate of knees that undergo manipulation under anesthesia (MUA). The purpose of this study is to evaluate the long-term outcomes and survivorship of patients who required a MUA after primary total knee arthroplasty (TKA) compared with a cohort of patients who did not undergo a MUA. Between 2003 and 2007, 2,193 patients (2,783 knees) underwent primary TKA with 2-year minimum follow-up; 182 knees (6.5%) had a MUA. Patients who had a manipulation were younger ( p  < 0.001) and had worse preoperative range of motion (ROM) ( p  < 0.001). Postoperative ROM, Knee Society clinical (KSC), functional, and pain (KSP) scores, revisions, and survivorship were compared between MUA and no MUA. Mean follow-up was 9.7 years. MUA patients had lower postoperative ROM ( p  < 0.001), change in ROM ( p  < 0.001), KSC ( p  < 0.001), KSP ( p  < 0.001), and change in KSP scores (0.013). Revisions occurred in 18 knees (9.9%) in the MUA group compared with 77 knees (3%) without a MUA ( p  < 0.001). Most common reason for revision after MUA was continued stiffness (50%). Relative risk for revision after one MUA was 2.01 (95% confidence interval [CI], 1.1-3.8, p  < 0.001) and after three or more MUAs were 27.02 (95% CI, 16.5-44.1, p  < 0.001). Ten-year survival after MUA was 89.4% (95% CI, 87.1-91.7%) compared with 97.2% (95% CI, 96.9-97.5%) without a MUA ( p  < 0.001). Patients who undergo a MUA after primary TKA may have a knee at risk with higher revision rates, worse long-term clinical scores, ROM and survivorship., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: The purpose of this study is to evaluate early postoperative surgical and medical complications in patients undergoing staged bilateral total knee arthroplasty (TKA) and determine if the interval to the second stage influences the risk of complications., Methods: A retrospective review was performed from 2016 through 2018 of all staged bilateral primary TKA procedures, yielding a cohort of 1005 patients (2010 TKAs). Four groups were created based on the timing of the second stage: 3 to 6 weeks, 7 to 12 weeks, 13 to 24 weeks, and >24 weeks. Clinical data compared between groups included demographics, knee range of motion, University of California, Los Angeles (UCLA) activity score, Knee Society pain score, Knee Society clinical score, and Knee Society functional score. Postoperative complications within 90 days were evaluated, with complications after the second knee being the primary outcome., Results: The mean follow-up after second stage was 10.7 months (range, 3 to 37 months). No significant differences were found between groups in the range of motion, Knee Society pain, Knee Society clinical score, Knee Society functional score, or University of California Los Angeles activity score in either the first or second knee. After the first knee surgery, medical complications were highest in the >24-week group. After the second knee, there were no significant difference in manipulation (P = .9), wound complications (P = .7), venous thromboembolism (P = .8), or other medical complications (P = 1) based on the interval duration., Conclusion: The interval between staged TKA did not affect early medical or surgical complications after the second stage. Early clinical and function results were not different based on timing of the second surgery., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: With the growing demand for total knee arthroplasty (TKA), the burden of revision surgery will continue to rise. Revision knee arthroplasty has historically had worse survivorship than primary knee arthroplasty. The purpose of this study is to review the 10-year outcomes and survivorship of a modular revision knee system., Materials and Methods: A retrospective review was conducted on 109 patients (117 knees) who underwent a revision knee arthroplasty with the Vanguard® Super Stabilized Knee (SSK) Revision System (Zimmer Biomet; Warsaw, Indiana) who were eligible for 10-year minimum follow up. Clinical and radiographic data was obtained pre- and postoperatively, six weeks postoperatively, and then every year thereafter., Results: With an average follow up of 10.7 years (range, 2.3 to 14.1 years), the SSK revision system exhibited a notable improvement in both clinical and functional outcomes. Average knee range of motion improvement was 4.2 degrees (SD ±18). Manipulations under anesthesia were performed in six knees (5%). Re-revisions occurred in 27 knees (23%). Ten of the re-revisions were for aseptic loosening (37%), eight for periprosthetic infection (30%), five for instability (19%), and the remainder for other aseptic causes. Mean time to failure was 4.6 years (range, 1 to 9.1 years). The 10-year all-cause survival was 77% (95% confidence interval [CI], 73 to 81%). The 10-year aseptic survival was 83% (95% CI, 79 to 87%)., Conclusion: The findings of this study show an 83% 10-year aseptic survivorship with the Vanguard® SSK knee revision system. These results are comparable to long-term follow up of other revision knee systems.

Background: As total knee arthroplasty (TKA) continues moving to the outpatient arena, the demand for revision surgery will subsequently increase which draws into question the feasibility for some revision scenarios as an outpatient. The purpose of this study is to report on the safety of outpatient revision knee arthroplasty., Methods: From June 2013 through December 2018, 102 patients (106 knees) underwent revision knee arthroplasty at a free-standing ambulatory surgery center. Mean patient age was 58.0 years, and 43% of patients were male. Procedures included the following: 45 cases of unicompartmental arthroplasty to TKA, 54 TKA revisions, and 52 cases involved a full exchange of components., Results: Ninety-three patients (88%) were discharged the same day without incident, none required transfer to acute facility, and 13 required overnight stay with 4 of these for convenience and 9 for medical reasons. There were no major complications within the first 48 hours postoperative. One patient required readmission for treatment of ileus 11 days postoperative. There were no other readmissions, no subsequent surgeries, and no deaths within 90 days. One or more major comorbidities were present in 66 patients., Conclusion: Outpatient revision knee arthroplasty was found to be safe in carefully selected patients and case scenarios. Presence of medical comorbidities was not associated with risk of complications. The paradigm changes of patient education, medical optimization, and a multimodal program to mitigate the risk of blood loss and reduce need for narcotics facilitates performing some revision arthroplasties safely in an outpatient setting., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: The primary purpose of this study is to report the incidence of complications associated with outpatient total knee arthroplasty (TKA). Secondarily, 2-year minimum outcomes are reported., Methods: Between 2013 and 2016, 928 patients underwent 1143 outpatient TKAs with the Vanguard Complete Knee System (Zimmer Biomet, Warsaw, IN). Patients were selected for outpatient surgery if they were medically optimized without a failing organ system and had sufficient support at home. Overnight stays, medical complications and early perioperative complications were assessed in this entire cohort. Two-year minimum follow-up was available on 793 patients (978 knees). Patient records were analyzed for outcome measures and revisions., Results: In 124 procedures, the patient stayed overnight for 23-h observation. Thirty-seven (3.2%) were for convenience reasons and 87 (7.6%) for medical observation. Heart disease and chronic obstructive pulmonary disease were associated with increased risk of overnight stay. Excluding manipulations, reoperation within 90 days occurred in eight (0.7%) knees. Patients with 2-year minimum follow-up had significant improvements in ROM, Knee Society Clinical, Functional and Pain scores (p < 0.005). Nine (0.8%) patients required revision. Manipulations were performed on 118 (10.3%) patients. The overall deep infection rate was 0.17% (2/1143)., Conclusions: Outpatient TKA is safe for a large proportion of patients. Certain medical co-morbidities increase the risk of overnight stay. Patients had significant improvement in ROM and outcome scores with low revision rate., Level of Evidence: III.

Background: The impact of a patient's activity level following total knee arthroplasty (TKA) remains controversial, with some surgeons concerned about increased polyethylene wear, aseptic loosening, and revisions. The purpose of this study is to report on implant survivorship and outcomes of high activity patients compared to low activity patients after TKA., Methods: A retrospective review identified 1611 patients (2038 knees) that underwent TKA with 5-year minimum follow-up. Patients were divided in 2 groups based on their University of California Los Angeles (UCLA) activity level: low activity (LA) (UCLA ≤5) and high activity (HA) (UCLA ≥6). Outcomes included range of motion, Knee Society scores, complications, and reoperations. Parametric survival analysis was performed to evaluate the significance of activity level on survivorship while controlling for age, gender, preoperative pain, Knee Society clinical scores, Knee Society functional scores, and body mass index (BMI)., Results: Mean follow-up was 11.4 years (range 5.1-15.9). The LA group had significantly more female patients, were older, had higher BMI, and had lower functional scores preoperatively (all with P < .001). The HA group had significantly higher improvements in Knee Society scores (P < .001) and pain postoperatively (P < .001). Revisions were performed in 4% of the LA group and 1.7% knees of the HA group (P = .003). After controlling for age, gender, preoperative pain, Knee Society clinical scores, Knee Society functional scores, and BMI, a higher postoperative activity level remained a significant factor for improved survivorship with an odds ratio of 2.4 (95% confidence interval 1.2-4.7, P = .011). The all-cause 12-year survivorship was 98% for the HA group and 95.3% for the LA group (P = .003). The aseptic 12-year survivorship was 98.4% for the HA group and 96.3% for the LA group (P = .02)., Conclusion: Highly active patients had increased survivorship at 5-year minimum follow-up compared to lower activity patients after TKA. Patient activity level after TKA may not need to be limited with modern implants., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The purpose of this study is to report the long-term outcomes and survivorship of a high flexion knee system., Methods: We identified 1312 patients (1664 knees) who underwent primary total knee arthroplasty with the Vanguard Complete Knee System with 10-year minimum follow-up. Preoperative and postoperative range of motion, Knee Society scores, complications, and reoperations were evaluated., Results: At an average of 11.9 years of follow-up, 88 knees were revised (5.3%). The deep infection rate was 1.4%. There was an average range of motion improvement of 3.9°, pain level decreased by 35.8, Knee Society clinical scores improved by 48, and Knee Society functional scores improved by 15.1 (all P < .001). Survival was 96.4% at 10 years for aseptic causes and 95.5% for all causes., Conclusion: At a 10-year minimum follow-up, this high flexion knee system demonstrates excellent survivorship., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Patients are often cautioned against a high level of activity after knee arthroplasty. The purpose of this study was to report on implant survivorship and outcomes of high-activity patients compared with low-activity patients after unicondylar knee arthroplasty (UKA)., Methods: We identified 487 patients (576 knees) who underwent UKA with the Oxford mobile bearing knee (Zimmer Biomet, Warsaw, IN) with a 5-year minimum follow-up. Patients were divided into 2 groups: low activity (LA) (University of California Los Angeles ≤6) and high activity (HA) (University of California Los Angeles ≥7). Preoperative and postoperative range of motion, Knee Society scores, complications, and reoperations were evaluated., Results: Mean follow-up was 9 years (range, 4 to 13.1). The HA group had significantly more male patients, were younger, and had higher knee society clinical scores and knee society functional scores preoperatively. The HA group had significantly higher improvements in Knee Society scores and pain postoperatively. Revisions were performed in 8.4% of the LA group and 6.2% of the HA group (P = .43). At our mean of 9-year follow-up, there was 94.0% survival for the HA group and 92.1% for the LA group (P = .6085)., Conclusions: Highly active patients had no increased risk of revision after UKA with the Oxford mobile bearing knee at 5-year minimum follow-up., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Treatment of isolated lateral compartment arthritic disease with partial knee arthroplasty remains underutilized in comparison to medial unicompartmental arthroplasty. This study examines the survival and outcome of lateral unicompartmental arthroplasty utilizing the first implant specifically developed for the lateral compartment., Materials and Methods: A retrospective review was performed to detect lateral unicompartmental arthroplasty procedures performed in our practice between January 2013 and May 2016. Patients indicated for surgery met specific preoperative clinical and radiographic criteria confirming lateral compartment arthritic disease with a correctable deformity, intact full-thickness medial cartilage, competent anterior cruciate ligament, and minimal disease in the patellofemoral compartment. A single implant design was used in all cases which consisted of a fixed-bearing tibial component specifically adapted to lateral compartment anatomy. Unicompartmental arthroplasty surgical technique was adjusted to attempt to recreate lateral compartment kinematics., Results: Fifty-two consecutive patients (56 knees) with lateral unicompartmental arthroplasty procedures meeting minimum two-year follow up were included in the study. Thirty-nine patients were female, and 93% of cases were performed for treatment of osteoarthritis. At a mean follow up of nearly three years, Knee Society clinical and functional scores improved postoperatively by a mean difference of 41 and 21, respectively. There were two reoperations, one medial unicompartmental arthroplasty for osteoarthritis progression and a superficial debridement for a non-healing wound. Thus, failure of lateral unicondylar knee arthroplasty (UKA) was less than 2% in this study. There were no other component revisions, radiographic evidence of loosening, or clinical failures., Conclusions: At early follow up, lateral unicompartmental arthroplasty using a modified surgical technique and an implant specifically designed for the lateral compartment is a reliable treatment for isolated lateral femorotibial arthritis when meeting defined indications.

Background: Persistent pain after medial unicompartmental knee arthroplasty (UKA) is a prevailing reason for revision to total knee arthroplasty (TKA). Many of these pathologies can be addressed arthroscopically. The purpose of this study is to examine the outcomes of patients who undergo an arthroscopy for any reason after medial UKA., Methods: A query of our practice registry revealed 58 patients who had undergone medial UKA between October 2003 and June 2015 with subsequent arthroscopy. Mean interval from medial UKA to arthroscopy was 22 months (range 1-101 months). Indications for arthroscopy were acute anterior cruciate ligament tear (1), arthrofibrosis (7), synovitis (12), recurrent hemarthrosis (2), lateral compartment degeneration including isolated lateral meniscus tears (11), and loose cement fragments (25)., Results: Mean follow-up after arthroscopy was 49 months (range 1-143 months). Twelve patients have been revised from UKA to TKA. Relative risk of revision after arthroscopy for lateral compartment degeneration was 4.27 (6 of 11; 55%; P = .002) and for retrieval of loose cement fragments was 0.05 (0 of 25; 0%; P = .03). Relative risk for revision after arthroscopy for anterior cruciate ligament tear, arthrofibrosis, synovitis, or recurrent hemarthrosis did not meet clinical significance secondary to the low number of patients in these categories., Conclusion: The results of this study suggest that arthroscopic retrieval of cement fragments does not compromise UKA longevity. However, arthroscopy for lateral compartment degradation after UKA, while not the cause of revision, appears to be an ineffective treatment and predicts a high risk of revision to TKA regardless of its relative radiographic insignificance., (Copyright © 2018. Published by Elsevier Inc.)

Background: Despite improvements in polyethylene bearing surface properties, only 1 previous study has examined the results of larger thickness bearings. The purpose of this study was to determine whether polyethylene thickness influenced patient outcomes and implant survival following modular total knee arthroplasty., Methods: A retrospective review was performed of patients undergoing primary total knee arthroplasty from 2003 to 2014 in a single practice database. Patients were separated into "thin" and "thick" polyethylene groups based on manufacturer polyethylene bearing sizes of 14 mm or less compared to those greater than 14 mm, respectively. Patient clinical outcomes, need for revision surgery, and overall implant survival rates were evaluated., Results: A total of 6698 primary knee arthroplasties were included, and a thin bearing was used in 96.5% of these cases. Preoperatively, patients with a thick bearing had significantly lower Knee Society clinical scores (P < .01), a trend toward lower functional scores (P = .06), and more significant coronal plane deformity. Postoperatively, patients with thick bearings exhibited better Knee Society clinical and pain scores as well as similar functional scores and University of California at Los Angeles activity scores. The overall reoperation rate and 10-year survivorship free of revision were similar between thick and thin bearings (1.7% vs 2.3%; 98.2% vs 96.1%). Patients with thin bearings were twice as likely to require a manipulation under anesthesia postoperatively (P = .02), while there were no failures in the thick bearing group due to aseptic loosening or instability., Conclusion: Patients with thick polyethylene bearings performed similarly or better in multiple clinical outcomes and survivorship compared to those with thin bearings., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Unicompartmental knee arthroplasty (UKA) is touted as a more conservative, bone- and tissue-sparing procedure than total knee arthroplasty (TKA). Similarly, revision of UKA to TKA is generally a simpler procedure than revision of TKA to TKA and can be accomplished with primary TKA components in most cases. The purpose of this study was to review a consecutive series of patients undergoing revision of failed UKA to TKA to determine if etiology is similar to that reported in recent literature and evaluate if the results align more with primary TKA vs revision of TKA to TKA., Methods: A query of our private practice registry from 1996 to 2015 revealed 184 patients (193 knees) who underwent revisions of failed UKA with minimum 2-year follow-up. The mean age was 63.5 (37-84) years, body mass index was 32.3 (19-57) kg/m 2 , and interval after UKA was 4.8 (0-35) years. The most prevalent indications for UKA revision were aseptic loosening (42%) arthritic progression (20%), and tibial collapse (14%)., Results: At 6.1-year mean follow-up (2-20), 8 knees (4.1%) required re-revision, which is similar to what we reported at 5.5 years in a group of primary TKA patients (6 of 189; 3.2%) and much lower than what we observed at 6.0 years in a recent study of aseptic revision TKA patients (35 of 278; 12.6%). In the study group, Knee Society clinical and function scores improved from 50.8 and 52.1 preoperatively to 83.4 and 67.6 at the most recent evaluation. Re-revisions were for aseptic loosening (3), instability (2), arthrofibrosis (2), and infection (1)., Conclusions: Compared to published individual institution and national registry data, re-revision rates of failed UKA are equivalent to revision rates of primary TKA and substantially better than re-revision rates of revision TKA. These data should be used to counsel patients undergoing revision UKA to TKA., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Medial unicompartmental knee arthroplasty (UKA) may have advantages over total knee arthroplasty (TKA) in the setting of obesity. There has been no direct comparison between the two cohorts. This study compares outcomes and complications of severely obese patients undergoing medial UKA versus TKA., Methods: Six hundred and fifty medial UKA and 1300 TKA were performed in patients with BMI >35kg/m 2 (mean 41kg/m 2 ) between 2007 and 2012. Pre- and postoperative ROM, Knee Society scores, perioperative factors, complications and reoperations were compared., Results: UKA patients had higher preoperative ROM, and Knee Society pain (KSP), functional (KSF), and clinical (KSC) scores (p<0.001, p=0.0008, p=0.0003, p=0.051 respectively). Mean tourniquet times, operative times, and lengths of stay were lower after UKA. Four TKA patients required transfusion. Mean follow-up was 2.3years. The frequency of manipulation under anesthesia was higher in TKA patients (p<0.001), while the rate of component revision was similar between the two groups (1.2% vs. 1.7%, p=0.328). Frequency of deep infection was lower in the UKA group (p=0.016). Postoperative KSF, change in KSF, and ROM were higher (p<0.0001) after UKA, but KSP and KSC were equivalent., Conclusions: Severely obese patients who underwent medial UKA demonstrated equal survivorship with substantially fewer reoperations, reduced deep infection, and less perioperative complications at short term follow-up. Severely obese patients had improved KSF scores and maintenance of ROM after UKA compared with TKA., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Total knee arthroplasty is overall a very successful surgery, but complications do occur. These complications include aseptic loosening of the tibial component, and obese patients are among the highest risk group. High-viscosity cement (HVC) has been implicated as a possible cause for aseptic loosening of the tibial component. The purpose of this study was to evaluate the incidence of aseptic loosening of the tibial component in obese patients with the use of HVC and standard tibial tray., Methods: We identified 1366 obese patients (1851 knees) with a body mass index >35 kg/m 2 and 2-year minimum follow-up who underwent primary total knee arthroplasty using HVC and a symmetrical, grit-blasted, cobalt-chrome tibial component with 40-mm stem. Preoperative and postoperative range of motion, Knee Society (KS) scores, complications, and reoperations were evaluated. Specifically, we assessed the rate of tibial aseptic loosening., Results: At a mean 5.4 years follow-up, only 1 in 1851 knees had aseptic loosening of the tibial component for an incidence of 0.054%. There was a mean increase of 3.3 degrees of knee range of motion. KS pain level decreased by 38.6 points (50 point scale). KS clinical scores improved by 52.2, Knee Society functional scores improved by 19.5, University of California, Los Angeles, activity score improved by 0.9, and Oxford Knee Score by 15.7. All these improvements were statistically significant with P < .001., Conclusion: Standard tibial components and HVC can be used in most patients, including the high-risk obese group, with low rates of tibial aseptic loosening., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Revision total knee arthroplasty (TKA) poses unique challenges compared with primary TKA such as bone loss, deformity, and ligament instability. Modular component options allow flexibility to deal with these complexities. The purpose of this study was to evaluate midterm outcomes for revision TKA using a modular revision knee system with complete interchangeability and multiple options for augmentation, offset, constraint, and stem extensions., Methods: A query of our practice registry revealed 257 consented patients (274 knees and 278 TKA) with minimum 2-year follow-up who underwent aseptic revision TKA with a modular system (Vanguard Super Stabilized Knee; Zimmer Biomet, Warsaw, IN) between 2005 and 2013. Four patients were rerevised to a second Vanguard Super Stabilized Knee within the study period. Mean age was 68 years, and mean number of previous surgeries was 2 (1-14)., Results: At mean follow-up of 6.0 years (range, 2-11 years), there have been 25 aseptic revisions involving one or more components (9.0%): 15 aseptic loosening with concomitant instability in 2, 8 others with instability, 1 with hypersensitivity, and 1 revised elsewhere for unknown cause. Ten knees were revised for infection. Range of motion improved from 100° preoperatively to 105° most recently. Knee Society clinical scores improved from 45 to 79, and function scores from 46 to 56. Radiographic evaluation revealed satisfactory position, fixation, and alignment in 97% and abnormal findings in 7 knees: 4 limited to the patella, 1 tibial radiolucency, 1 femoral and tibial radiolucency, and 1 tibial subsidence., Conclusion: The results of this modular TKA revision system at 6 years mean follow-up are promising for use in complex scenarios, with a low frequency of aseptic rerevision, good knee stability, and substantial improvements in range of motion and clinical and functional outcomes., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Introduction: The gender-specific total knee arthroplasty (TKA) debate focuses on differences in distal femoral mediolateral to anteroposterior aspect ratio between males and females. However, randomized studies have been unable to demonstrate significant differences in outcomes utilizing gender-specific implants. No studies have examined the effect of intermediate femoral component sizes on outcome. We compared outcomes before and after intermediate sizing availability., Materials and Methods: We identified 331 patients (413 knees) who underwent primary TKA between 2003 and 2004 with a single complete knee system. There were 121 males and 210 females. Three intermediate femoral sizes were added in March 2004 to the six initial options. Patients before March 2004 were assigned to group 1 (n=178), and after to group 2 (n=235)., Results: Follow-up averaged 8.5 years. Preoperative demographics and clinical scores were similar between groups. Knee Society (KS) clinical and functional scores improved in females in both groups, but there was no significant difference. Male patients in group 2 had a significant improvement in KS clinical scores compared to male patients in group 1 (group 1: 33.9, group 2: 41.1; p=0.01). Females in group 2 had significantly less need for manipulation, 1.9%, versus females in group 1, 8.7% (p=0.01). MUA rates were similar for men between groups. Overall, there were 19 revisions (4.6%) with no differences between groups or by genders. Once intermediate sizes were available, they were used in 48% of females and 13% of males. The average femoral component size for females in group 1 was 65 mm and decreased in group 2 to 62.5 mm. The average size of femoral components in males was 70 mm in both groups., Conclusions: Availability of intermediate size femoral component sizes was associated with a lower rate of manipulation in female patients. Greater KS clinical score improvement was observed in men after availability of additional femoral sizes.

Background: In past decades, polyethylene wear was a major cause of failure in total knee arthroplasty (TKA). Polyethylene for use in arthroplasty has been vastly improved in recent years, with improved materials as well as manufacturing and sterilization processes. Testing has shown that infusion of vitamin E prevents oxidative degradation of polyethylene without remelting, allowing the material to maintain mechanical properties and wear resistance over time. The purpose of this study is to review the early result of patients undergoing primary TKA with vitamin E antioxidant-infused polyethylene inserts., Materials and Methods: A query of our practice registry revealed 148 patients (163 knees) who underwent primary cemented TKA using the Vanguard® Complete Knee System and E1® Antioxidant Infused polyethylene bearings (Zimmer Biomet, Warsaw, Indiana) between May 2009 and May 2013. Indications for E1® bearings were younger, more active patients. There were 65 males (44%) and 82 females (56%). Mean age was 50.6 years and mean BMI was 37.3 kg/m2., Results: At mean follow-up of 3.2 years (range 6 weeks to 6.4 years), there have been seven revisions (4.3%): three two-staged exchanges for infection, two for arthrofibrosis (one insert only, one femoral and tibial), and two (insert only) for late instability with imbalanced tight posteromedial and loose lateral structures. No aseptic loosening has occurred. Mean range of motion improved from 108° preoperatively to 112°, Knee Society clinical scores improved from 36 to 84 and function scores from 56 to 66. Postoperative radiographs, available for 160 TKA, revealed lateral patellar tilt in one knee, and satisfactory position, alignment, and fixation in all others., Conclusion: At up to 6.4 years' follow-up, two mechanical failures of the device have occurred and no aseptic loosening. Survival was 100% with aseptic loosening as the endpoint, and 95.7% with revision for any reason as the endpoint.

Aims: An evidence-based radiographic Decision Aid for meniscal-bearing unicompartmental knee arthroplasty (UKA) has been developed and this study investigates its performance at an independent centre., Patients and Methods: Pre-operative radiographs, including stress views, from a consecutive cohort of 550 knees undergoing arthroplasty (UKA or total knee arthroplasty; TKA) by a single-surgeon were assessed. Suitability for UKA was determined using the Decision Aid, with the assessor blinded to treatment received, and compared with actual treatment received, which was determined by an experienced UKA surgeon based on history, examination, radiographic assessment including stress radiographs, and intra-operative assessment in line with the recommended indications as described in the literature., Results: The sensitivity and specificity of the Decision Aid was 92% and 88%, respectively. Excluding knees where a clear pre-operative plan was made to perform TKA, i.e. patient request, the sensitivity was 93% and specificity 96%. The false-positive rate was low (2.4%) with all affected patients readily identifiable during joint inspection at surgery. In patients meeting Decision Aid criteria and receiving UKA, the five-year survival was 99% (95% confidence intervals (CI) 97 to 100). The false negatives (3.5%), who received UKA but did not meet the criteria, had significantly worse functional outcomes (flexion p < 0.001, American Knee Society Score - Functional p < 0.001, University of California Los Angeles score p = 0.04), and lower implant survival of 93.1% (95% CI 77.6 to 100)., Conclusion: The radiographic Decision Aid safely and reliably identifies appropriate patients for meniscal-bearing UKA and achieves good results in this population. The widespread use of the Decision Aid should improve the results of UKA. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):3-10., (©2016 Murray et al.)

Aims: Since redesign of the Oxford phase III mobile-bearing unicompartmental knee arthroplasty (UKA) femoral component to a twin-peg design, there has not been a direct comparison to total knee arthroplasty (TKA). Thus, we explored differences between the two cohorts., Patients and Methods: A total of 168 patients (201 knees) underwent medial UKA with the Oxford Partial Knee Twin-Peg. These patients were compared with a randomly selected group of 177 patients (189 knees) with primary Vanguard TKA. Patient demographics, Knee Society (KS) scores and range of movement (ROM) were compared between the two cohorts. Additionally, revision, re-operation and manipulation under anaesthesia rates were analysed., Results: The mean follow-up for UKA and TKA groups was 5.4 and 5.5 years, respectively. Six TKA (3.2%) versus three UKAs (1.5%) were revised which was not significant (p = 0.269). Manipulation was more frequent after TKA (16; 8.5%) versus none in the UKA group (p < 0.001). UKA patients had higher post-operative KS function scores versus TKA patients (78 versus 66, p < 0.001) with a trend toward greater improvement, but there was no difference in ROM and KS clinical improvement (p = 0.382 and 0.420, respectively)., Conclusion: We found fewer manipulations, and higher functional outcomes for patients treated with medial mobile-bearing UKA compared with TKA. TKA had twice the revision rate as UKA although this did not reach statistical significance with the numbers available. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):28-33., (©2016 Berend et al.)

Previous reports have stated that MRI is less accurate than CT for patient specific guide creation in total knee arthroplasty (TKA). Twenty-three TKAs were performed with CT-based guides and 27 with MRI-based guides. A mechanical axis through the central third of the knee was achieved in 88.9% of MRI-guided TKA versus 69.6% of CT-guided TKA (p=0.07). There were nine component outliers in the CT group (39.1%) and two in the MRI group (7.4%, p=0.00768). The relative risk of having an outlier using a CT-based guide was 5.28 times that of an MRI-based guide. Superior overall alignment and fewer outliers were achieved with the use of MRI compared with CT. MRI is the best imaging modality for surgeons wishing to utilize patient specific guides for TKA., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Articulating spacers have been reported to promote greater range of motion, preserve bone, facilitate reimplantation, and enhance functional recovery, as well as provide a vehicle for local administration of antibiotics. The purpose of this study was to review patients treated at our center for deep hip and knee infection with two-staged exchange using molded, articulating antibiotic-laden cement spacers following debridement. A query of our practice registry revealed 84 patients (84 hips) and 177 patients (182 knees) diagnosed with deep infection after THA and TKA respectively, and treated with two-staged exchange using molded articulating cement spacers. Mean follow-up was three years in both groups. Second-stage reimplantation was accomplished in 81 hips, and reinfection occurred in 11 of those (14%), with three responding to a single irrigation and debridement (I&D) procedure, one undergoing two I&Ds, one chronically infected diabetic patient treated with one-stage exchange to cemented components, five patients undergoing multiple procedures including repeat two-staged exchange in four, and one patient declining further treatment. Harris hip score at most recent averaged 69. Second-stage reimplantation was accomplished in 177 knees, and reinfection occurred in 28 of those (16%). Range of motion improved from 93° preoperatively to 101° at most recent, Knee Society clinical scores improved from 46 to 76, and functional scores improved from 32 to 47. Treatment of deep infection after total joint arthroplasty using molded, articulating antibiotic-laden acrylic cement spacers was successful in eradicating infection in 83% of hips (70 of 84) and 82% of knees (149 of 182) at an average of three years after reimplantation.

The femoral component and proprietary instrumentation of a mobile-bearing unicompartmental knee arthroplasty (UKA) was redesigned with an additional peg for enhanced fixation, 15° of extra femoral surface for contact in deep flexion, more rounded profile, better fit into the milled surface, and redesigned intramedullary based instrumentation. To assess the benefit of these changes, we compared postoperative radiographs of 219 single-peg and 186 twin-peg UKAs done in 2008-2011. All surviving knees demonstrated satisfactory position and alignment with no radiolucencies observed. Radiographic analysis showed improved and consistent component positioning with the twin-peg design implanted with updated instrumentation compared with the single-peg. The radiographic benefits of improved implant positioning using the twin-peg component and updated instrumentation are clear and carry tremendous potential. More robust follow-up is imperative., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Previous studies of failure mechanisms leading to revision total knee replacement (TKR) performed between 1986 and 2000 determined that many failed early, with a disproportionate amount accounted for by infection and implant-associated factors including wear, loosening and instability. Since then, efforts have been made to improve implant performance and instruct surgeons in best practice. Recently our centre participated in a multi-centre evaluation of 844 revision TKRs from 2010 to 2011. The purpose was to report a detailed analysis of failure mechanisms over time and to see if failure modes have changed over the past 10 to 15 years. Aseptic loosening was the predominant mechanism of failure (31.2%), followed by instability (18.7%), infection (16.2%), polyethylene wear (10.0%), arthrofibrosis (6.9%) and malalignment (6.6%). The mean time to failure was 5.9 years (ten days to 31 years), 35.3% of all revisions occurred at less than two years, and 60.2% in the first five years. With improvements in implant and polyethylene manufacture, polyethylene wear is no longer a leading cause of failure. Early mechanisms of failure are primarily technical errors. In addition to improving implant longevity, industry and surgeons must work together to decrease these technical errors. All reports on failure of TKR contain patients with unexplained pain who not infrequently have unmet expectations. Surgeons must work to achieve realistic patient expectations pre-operatively, and therefore, improve patient satisfaction post-operatively., (©2014 The British Editorial Society of Bone & Joint Surgery.)

Debate has raged over whether a cruciate retaining (CR) or a posterior stabilised (PS) total knee replacement (TKR) provides a better range of movement (ROM) for patients. Various sub-sets of CR design are frequently lumped together when comparing outcomes. Additionally, multiple factors have been proven to influence the rate of manipulation under anaesthetic (MUA) following TKR. The purpose of this study was to determine whether different CR bearing insert designs provide better ROM or different MUA rates. All primary TKRs performed by two surgeons between March 2006 and March 2009 were reviewed and 2449 CR-TKRs were identified. The same CR femoral component, instrumentation, and tibial base plate were consistently used. In 1334 TKRs a CR tibial insert with 3° posterior slope and no posterior lip was used (CR-S). In 803 there was an insert with no slope and a small posterior lip (CR-L) and in 312 knees the posterior cruciate ligament (PCL) was either resected or lax and a deep-dish, anterior stabilised insert was used (CR-AS). More CR-AS inserts were used in patients with less pre-operative ROM and greater pre-operative tibiofemoral deformity and flexion contracture (p < 0.05). The mean improvement in ROM was highest for the CR-AS inserts (5.9° (-40° to 55°) vs CR-S 3.1° (-45° to 70°) vs CR-L 3.0° (-45° to 65°); p = 0.004). There was a significantly higher MUA rate with the CR-S and CR-L inserts than CR-AS (Pearson rank 6.51; p = 0.04). Despite sacrificing or not substituting for the PCL, ROM improvement was highest, and the MUA rate was lowest in TKRs with a deep-dish, anterior-stabilised insert. Substitution for the posterior cruciate ligament (PCL) in the form of a PS design may not be necessary even when the PCL is deficient.

Isolated patellofemoral arthritis can be a disabling condition that can be challenging to treat. Patients with symptoms recalcitrant to conservative measures are considered for total or partial knee arthroplasty. This retrospective study reports the results of patellofemoral arthroplasty at a single center using a variety of implant designs. Thirty patients (37 knees) with isolated patellofemoral disease treated with patellofemoral arthroplasty with a minimum of one year follow-up were evaluated. The majority of patients were female (83%) and the underlying diagnosis was osteoarthritis in 98% of knees. Reported follow-up averaged 31 months. Average Knee Society Pain, Functional, and Clinical Scores improved from pre-op to most recent follow-up. Two complications (5.4%) required intervention. One patient was converted to a total knee arthroplasty secondary to patella instability., (Copyright © 2013. Published by Elsevier Inc.)

Background: The complication risk of staged versus simultaneous total knee arthroplasty continues to be debated in the literature. Previous reports suggest unicompartmental knee arthroplasty provides a more rapid functional recovery than total knee arthroplasty. However, little data exist on whether simultaneous unicompartmental knee arthroplasty can be performed without increasing the perioperative risk compared with staged unicompartmental knee arthroplasty., Questions/purposes: We therefore asked if there is an increased risk of perioperative complications with bilateral simultaneous unicompartmental knee arthroplasty., Methods: We retrospectively compared 141 patients (282 knees) treated with staged unicompartmental knee arthroplasty with 35 patients (70 knees) treated with simultaneous unicompartmental knee arthroplasty to evaluate perioperative complications and short-term results assessed by Knee Society function scores and the Lower Extremity Activity Scale., Results: Patients who underwent simultaneous unicompartmental knee arthroplasty had a shorter cumulative operative time (109 versus 122 minutes), a shorter cumulative length of hospital stay (1.7 versus 2.5 days), higher Knee Society function scores at most recent followup (88 versus 73), and higher Lower Extremity Activity Scale (12.0 versus 10.2) without a difference in perioperative complications. The simultaneous cohort was younger (59 versus 63 years of age) and less obese (body mass index 31 versus 33 kg/m(2)) than the staged group., Conclusions: Although we found a substantial bias for performing simultaneous unicompartmental knee arthroplasty in younger and less obese patients, these data suggest it can be performed without increasing perioperative morbidity or mortality in this patient population., Level of Evidence: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Enhancement of our perioperative pain management protocols has resulted in accelerated rehabilitation. At our facility, the majority of patients undergoing total and partial knee arthroplasty are treated with a single-shot spinal anesthetic consisting of a combination of bupivacaine and duramorph. The bupivacaine affords the immediate perioperative anesthetic while the duramorph results in sustained analgesia for a period of 12 to 24 hours. We use intra-articular injections delivered directly into the soft tissue of the knee. Our current intra-articular injection is 60 mL of 0.5% ropivacaine with 0.5 mg of epinephrine. In patients with a normal renal function, 30 mg of ketorolac is added. The injection is administered throughout all of the soft tissues in and around the knee. Prophylactic antiemetics are administered in the form of dexamethasone, ondansetron, and a scopolamine patch. The use of this perioperative anesthesia provides effective pain relief with no motor blockade. Patients are able to participate in physiotherapy within several hours of the operative procedure, performing active range of motion and ambulating with assistive devices. Patients with no significant cardiovascular history are given celecoxib preoperatively, which is continued for approximately 2 weeks postoperatively. Additionally, all patients are treated with oxycodone, either preoperatively or within 2 hours of arrival to the floor postoperatively. Patients younger than 70 years are given 20 mg of oxycodone while those older than 70 years are given 10 mg of oxycodone. The oxycodone is continued for the first 24 hours of the hospital stay. Patients are then managed with oxycodone and hydrocodone. Length of stay has decreased and currently averages <2 days., (Copyright 2010, SLACK Incorporated.)

Bone deficiency represents a common theme in revision total knee arthroplasty (TKA). The etiology of bone deficiency may be aseptic loosening resulting in direct mechanical bone loss, osteolysis, stress shielding, septic loosening, or iatrogenic resulting from implant removal. Not all revisions are created equal. The surgeon must assess the degree of complexity and have a broad armamentarium available. Principles to consider in bone loss management are defect size and location and patient demographics, including body mass index, activity level, age, and life expectancy. Treatment options include polymethylmethacrylate (PMMA) with or without reinforcing screws; modular TKA systems including optional stems, wedges, and metal augments; orthopedic salvage systems such as mega- or tumor prostheses; autograft; and morselized or structural allograft. Morselized allograft is better suited for reconstitution of contained deficits and may be associated with a higher rate of incorporation. Disadvantages of allograft include late resorption, fracture or nonunion of structural allograft, and risk of disease transmission. A recent innovation has been a variety of augments and cones fabricated in the new ultraporous metals to address structural defects in revision TKA. Recommendations for bony reconstruction include: for deficits <5 mm, PMMA fill; for deficits 5 to 10 mm and <50% of the femoral condyle or tibial plateau, PMMA with reinforcing screws; for contained deficits >5 mm, morselized allograft; for noncontained deficits 5 to 15 mm and >50% of the femoral condyle and tibial plateau, TKA modular systems with stems and augments; and for noncontained deficits >15 mm, structural allografts, megaprostheses, and ultraporous metal augments., (Copyright 2010, SLACK Incorporated.)

Obstructive sleep apnea (OSA) may be a risk factor for complications after total joint arthroplasty (TJA). We sought to determine the prevalence of OSA in patients undergoing TJA, and the safety and effectiveness of intrathecal narcotic (IN) in these patients. We retrospectively reviewed 1255 consecutive patients undergoing 1463 TJA at one hospital. All patients underwent routine screening for OSA and IN anesthesia, with 109 patients (134 TJA) identified with OSA (8.7%). Compared with 127 randomly selected patients (141 TJA) without OSA, OSA patients were significantly heavier and had higher American Society of Anesthesiologists scores, more comorbidities, longer length of stay, more transient hypoxia, more transfusions, and more medical variances. Despite more minor variances, with appropriate screening and management, OSA patients did not have a higher rate of significant or major complications. Length of stay, although longer, was only 2.3 days in OSA patients, demonstrating the safety and efficacy of IN anesthesia in these patients., (Copyright 2010 Elsevier Inc. All rights reserved.)

Comparisons in the literature of static and articulating spacers have shown average eradication rates of approximately 90% and 92%, respectively. Therefore, we can conclude that static and articulating spacers are both effective for eradication of infection. The benefits of articulating spacers are prevention of soft-tissue contracture, promotion of range of motion, and facilitation of antibiotic delivery.

Standard surgical criteria for unicondylar knee arthroplasty exclude patients who weigh >82 kg (187 lbs), patients aged <60 years, and patients with more than minimal erosive changes in the patellofemoral articulation, indicated clinically by anterior knee pain. In April 2004, the US Food and Drug Administration approved the Oxford phase 3 unicondylar prosthesis for implantation during unicompartmental knee arthroplasty. Since this broader indication was adopted, the implant has proven to be a bone- and ligament- conservative yet long-lasting intervention for anteromedial arthritis of the knee. The purpose of this study is to investigate the early outcomes of unicompartmental medial knee arthroplasty using the Oxford prosthesis in US patients who do not meet the standard inclusion criteria. Specifically, the current study investigates the impact of obesity, young age, patellofemoral arthritis, and isolated medial knee pain on the early outcomes of this device. In this large series of 318 unicompartmental knee arthroplasties performed in 270 patients, these standard preoperative contraindications had no influence on the successful outcome of the procedure using the Oxford phase 3 device.

Inability to achieve adequate range of motion (ROM) after total knee arthroplasty (TKA) represents a frustrating complication for both patient and surgeon. Manipulation under anesthesia is indicated in TKA having less than 90 degrees ROM after six weeks, with no progression or regression in ROM. A modified technique has evolved for patients with chronic regional pain syndrome (CRPS) symptoms or persistent stiffness after standard manipulation. A retrospective review was conducted to determine the efficacy of the modified technique, which uses epidural anesthesia continued for postoperative analgesia, hospital stay of one to three days, continuous passive motion (CPM) for two to three days, and daily physical therapy (PT). Between 1997 and 2003, 5714 TKAs were performed in 4106 patients. Manipulation using a standard technique was performed on 334 (5.8%) knees in 273 patients. Manipulation using a modified technique was performed on 65 (1%) knees in 60 patients. Age averaged 58 years and body mass index (BMI) averaged 34.39. Follow up averaged 18.4 months. ROM improved significantly from 71 degrees to 102 degrees (p < 0.0001). Knee Society pain, function, and total clinical scores all improved significantly (all p < 0.0001). Successful results were observed in 48 (74%) knees. Four (6%) additional knees achieved a successful result after a subsequent manipulation. Nine (14%) knees required component revision for treatment of persistent arthrofibrosis, which included one full revision, five polyethylene exchanges, and three revisions of femoral component and polyethylene. Two significant complications occurred: one subdural hematoma and one death due to pulmonary embolism. Although not without complications, manipulation under epidural anesthesia represents a viable option for treatment of persistent stiffness after TKA; 80% of these difficult cases achieved successful results.

Unlabelled: There has been increasing use of and expanding indications for unicompartmental knee arthroplasty using minimally invasive techniques. We sought to define contraindications by examining failures. We retrospectively reviewed the early results of a consecutive series of minimally invasive medial unicompartmental knee arthroplasty using two implant designs. Seventy-nine consecutive unicompartmental knee arthroplasty cases (48 instrumented and 31 noninstrumented) with minimum 2-year followup were reviewed. Patients with radiographic involvement with or without pain referable to the lateral compartment or to the patellofemoral joint were not considered candidates. Failure was defined as revision or pending revision. The average followup was 40.2 months. There were 16 failures (six tibial loosening, three plateau fracture, four persistent medial pain, one progressive arthritis, and two sepsis). Age, gender, disease severity and implant design did not predict failure. Body mass index greater than 32 did predict failure and was associated with a reduction in survivorship by log-rank and Wilcoxon analyses. These results show reliable success if obesity is considered a contraindication and technical errors resulting in fracture are eliminated. Better defining the ideal candidate for unicompartmental knee arthroplasty, with obesity remaining a contraindication, will make this a more predictable and reliable procedure., Level of Evidence: Prognostic study, Level IV-2 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

The purpose of this study was to determine if an intraoperative intraarticular and soft-tissue injection of local anaesthetic, epinephrine, and morphine has a beneficial effect for total knee arthroplasty. A control group of 138 patients (181 knees) received no intraoperative injection. The study group of 171 patients (197 knees) received intraoperative injection of 0.25% bupivacaine with epinephrine and morphine with 2/3 injected into the soft tissues and 1/3 injected into the joint. Patients having bilateral simultaneous procedures received a divided dose. The pain treatment protocol otherwise was identical. Pain, sedation, rescue narcotic usage, narcotic reversal and blood loss were examined. Pain levels during the immediate postoperative period, blood loss, and bleeding indices were reduced with injection. Considerably more control patients required rescue doses of narcotics. Preemptive analgesia with soft tissue and intra-articular injection of long-acting local anesthetic with epinephrine and morphine provides better pain control in the immediate postoperative period, decreases blood loss, and decreases the need for rescue narcotics and reversal agents. This simple, inexpensive method provides an effective adjunct to a multimodal approach in improving the postoperative course of primary total knee arthroplasty.

Venous thromboembolic disease (VTD), deep venous thrombosis and pulmonary embolism, causes morbidity and mortality following total hip and total knee arthroplasties, while ileus complicates up to 4.0%. The clinical courses of 2,949 patients undergoing 3,364 consecutive primary and revision total hip and total knee arthroplasties, radical debridements, and reimplantations at one institution over a 2-year period were reviewed to examine the relationship between ileus and VTD. VTD prophylaxis consisted of aspirin and intermittent plantar pulse boots for all patients except those at high risk, who received parenteral chemical prophylaxis and boots. Ileus occurred in 62 patients (2.1%) and symptomatic DVT in 51 (1.7%). With ileus, the incidence of DVT was 8.1%: odds ratio 5.5 (P =.0036). Symptomatic pulmonary embolism occurred in 7 patients (0.24%); with ileus the incidence was 3.2%: odds ratio 19.6 (P =.0082). A significant increase was observed in rates of VTD with ileus. We recommend using parenteral chemical and mechanical prophylaxis in patients with ileus following total hip and total knee arthroplasties.

A total of 242 knees in 198 patients undergoing total knee arthroplasty were reviewed to evaluate the effect of tourniquet deflation on lateral release rates, possible variables associated with the need for lateral release, and adequacy of intraoperative evaluation on final radiographs. The need for lateral release was determined using the "no-thumbs" and "full contact" rules and visual evaluation. Lateral release was performed after tourniquet deflation. A total of 171 (71%) knees needed a lateral release before tourniquet deflation. After tourniquet deflation, only 53 (22%) required lateral release, representing a 69% reduction. Obesity was the only other significant factor in lateral release requirement. Based on the observations of this study, it is recommended that the need for lateral release be evaluated after tourniquet deflation. A 69% reduction in lateral release supports the hypothesis that tourniquet pressure has an effect on patellar tracking. Lateral release appears to be effective in restoring normal patellar tilt, and obesity increases its need.

The fate of the posterior cruciate ligament in primary total knee arthroplasty is controversial. An algorithmic approach is presented that is based on pathologic criteria for evaluating and treating patients with primary total knee arthroplasty that will aid in the posterior cruciate ligament decision-making process, producing more predictable procedures and outcomes. A consecutive series of the first 120 patients (171 knees) who had primary posterior cruciate-retaining arthroplasty and the first 120 patients (180 knees) who had primary posterior-stabilized arthroplasty with a minimum 5-year followup in which the Maxim Complete Total Knee System and the algorithmic approach were used were compared. No statistically significant differences in outcome between the groups were observed. Among the patients who had posterior cruciate-retaining arthroplasty, no revisions attributable to aseptic loosening have been reported at an average followup of 6.39 years. The average followup Knee Society total score was 162.16 points, with 91 (54.8%) knees having excellent outcome ratings. No revisions attributable to aseptic loosening have been reported among the patients who had posterior-stabilized arthroplasty at an average followup of 5.98 years. The average followup Knee Society total score was 158.05 points, with excellent outcome ratings reported in 96 (54.9%) knees. The use of a standardized algorithm has streamlined the treatment of patients having primary total knee arthroplasty, consistently providing excellent clinical results when either retaining or sacrificing the posterior cruciate ligament.

The purpose of the current retrospective review was to compare the results of 1498 patients having 1090 simultaneous bilateral total knee arthroplasties and 958 unilateral total knee arthroplasties in a 3-year period, focusing on perioperative complications, length of hospital stay, and discharge disposition. Gender, age, diagnosis, and weight were similar between the groups. Patients undergoing simultaneous bilateral total knee arthroplasties had statistically significant higher amounts of intraoperative blood loss, with more patients requiring blood transfusion, and a higher average number of units of blood transfused compared with patients undergoing unilateral total knee arthroplasty. Overall, a significantly higher incidence of gastrointestinal complications was reported in patients who had simultaneous bilateral knee arthroplasties compared with patients who had unilateral knee arthroplasty. Comparing age subgroups within the unilateral group revealed significantly higher incidences of pulmonary, neurologic, cardiac, and genitourinary complications among patients 80 years or older versus patients younger than 80 years. Patients having simultaneous bilateral arthroplasties who were 80 years or older had significantly higher incidences of pulmonary, neurologic, and cardiac complications than patients younger than 80 years in that same group. These results suggest that age, not procedure, has a more significant role in the perioperative morbidity of total knee arthroplasty. Based on the results from the current study and previous literature documenting patient preference, patient satisfaction, efficacy, and outcomes comparable with those of patients having unilateral total knee arthroplasty, the authors continue to offer patients the option of simultaneous bilateral total knee arthroplasties.