Higher Activity Level Following Total Knee Arthroplasty Is Not Deleterious to Mid-Term Implant Survivorship

BackgroundThe 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.MethodsA 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).ResultsMean 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).ConclusionHighly 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.     

Anterior Knee Pain Following Primary Unilateral Total Knee Arthroplasty With Posterior-Stabilized Prosthesis and Patellar Resurfacing: Prevalence and Clinical Implications

BackgroundAnterior knee pain following total knee arthroplasty (TKA) is associated with patient dissatisfaction. Factors related to postoperative anterior knee pain and its impact on patient outcomes are poorly understood. The following are the aims of this study: (1) to report the prevalence of anterior knee pain before and after TKA using a posterior-stabilized prosthesis with routine patellar resurfacing; (2) to investigate the association of preoperative clinical factors with the presence of anterior knee pain after TKA; and (3) to explore the association of postoperative anterior knee pain with postoperative self-reported function and quality of life.MethodsThis retrospective study included 506 patients who had undergone elective primary unilateral TKA with a posterior-stabilized prosthesis and patellar resurfacing. Outcome measures prior to and 12 months after TKA included self-reported anterior knee pain, knee function, and quality of life.ResultsPrevalence of anterior knee pain was 72% prior to and 15% following TKA. Patients who had preoperative anterior knee pain had twice the risk of experiencing anterior knee pain after TKA than patients who did not have preoperative anterior knee pain (risk ratio: 2.37, 95% CI 1.73-2.96). Greater severity of preoperative anterior knee pain and worse self-reported function were associated with the presence of postoperative anterior knee pain (rho = 0.15, P < .01; rho = 0.13, P < .01, respectively). Preoperative age, gender, and quality of life were not associated with postoperative anterior knee pain. Greater severity of postoperative anterior knee pain was associated with worse knee function at 12 months postoperative (rho = 0.49, P < .01).ConclusionOne in 7 patients reported anterior knee pain 12 months following posterior-stabilized and patella-resurfaced TKA. The presence of preoperative anterior knee pain and worse self-reported function are associated with postoperative anterior knee pain.     

Comparison of Modular Conventional and High-Flexion Posterior-Stabilized Total Knee Arthroplasties in the Same Patients at a Mean Follow-Up of 15 Years

BackgroundAs previous studies are limited to short-term clinical data on conventional and high-flexion total knee arthroplasties (TKAs), long-term clinical data on these TKAs remain unclear. Therefore, we evaluated long-term functional outcome, range of knee motion, revision rate, implant survival, and the prevalence of osteolysis after conventional and high-flexion TKAs in the same patients.MethodsThe authors evaluated a cohort of 1206 patients with a mean age of 65.3 ± 7 years (range: 22-70) who underwent bilateral simultaneous sequential TKAs. One knee received a conventional TKA and the other received a high-flexion TKA. The mean duration of follow-up was 15.6 years (range: 14-17).ResultsNo significant differences were found between the 2 groups at the latest follow-up with respect to Knee Society score (93 vs 92 points, P = .765), pain score (45 vs 44 points, P = .641), range of knee motion (125° vs 126°, P = .712), and radiographic and computed tomography scan results. Furthermore, no significant revision rate differences were found between the 2 groups (1.3% for conventional TKA vs 1.6% for high-flexion TKA; P = .137). There was no osteolysis recorded in either group. The rate of survivorship free of implant revision or aseptic loosening was 98.7% (95% CI = 91-100) for conventional TKA and 98.4% (95% CI = 91-100) for high-flexion TKA at 17 years.ConclusionAt the latest follow-up, we were not able to demonstrate any significant difference between conventional and high-flexion TKAs with respect to functional outcome scores, range of knee motion, revision rate, implant survival, and prevalence of osteolysis.     

Does Unicompartmental Knee Replacement Offer Improved Clinical Advantages Over Total Knee Replacement in the Treatment of Isolated Lateral Osteoarthritis? A Matched Cohort Analysis From an Independent Center

BackgroundThe purpose of this study is to compare the functional and radiographic results, perioperative complications, satisfaction rate, and mid-term survivorship after unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) for the treatment of lateral compartmental knee osteoarthritis (LCKO).MethodsBetween March 2007 and September 2017, we identified 35 patients with primary TKAs and 121 patients with lateral UKAs (LUKAs) for LCKO with a minimum follow-up of 2 years (mean 5.3 years, range 2-12.4). The matched variables were age, gender, operation side, body mass index, American Society of Anesthesiologist grade, initial diagnosis, osteoarthritis grade in lateral compartment, and follow-up time. All patients were assessed using the Oxford Knee Score, Hospital for Special Surgery score, range of motion, length of hospital stay, satisfaction, and complications. Survivorship of UKA and TKA implants was also compared.ResultsAt last follow-up, LUKA had a significantly better postoperative Oxford Knee Score, Hospital for Special Surgery score, range of motion, shorter length of hospital time, and higher satisfaction rate than matched TKA group. There were significant differences regarding patellar tendon injury (P = .043), superficial wound infection (P = .028), patellar snapping or impingement (P = .047), and stiffness (P < .001). Five-year survivorships free from revision were similar in both groups (99.2% vs 97.1%, P = .347).ConclusionLUKA for LCKO demonstrated more favorable 5-year results in comparison with TKA. Furthermore, LUKA achieved comparable mid-term survivorship and was less likely to suffer from wound infection and knee stiffness, although not overall surgical complications.     

Interval Between Staged Bilateral Total Knee Arthroplasties Does Not Affect Early Medical or Surgical Complications

BackgroundThe 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.MethodsA 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.ResultsThe 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.ConclusionThe 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.     

Effect of Tourniquet Use on Patient Outcomes After Cementless Total Knee Arthroplasty: A Randomized Controlled Trial

BackgroundTourniquet use is common in total knee arthroplasty (TKA), but debate exists regarding its use and effect on patient outcomes. The study purpose was to compare the effect of short tourniquet (ST) time vs long tourniquet (LT) time on pain, opioid consumption, and patient outcomes.MethodsPatients were prospectively randomized to an ST time of 10 min vs LT time. A total of 100 consecutive patients undergoing primary cementless robotic-assisted TKA underwent randomization, with 5 patients unable to complete follow-up, leaving 49 in the ST group and 46 in the LT cohort. Visual analog scale pain scores, morphine equivalent, serum creatine kinase, distance walked, range of motion, length of stay (LOS), surgical time, hemoglobin (Hgb), and Knee Society Scores (KSS) were prospectively collected.ResultsVisual analog scale pain was statistically equivalent at 24, 48, and 72 hours and at 2 and 6 weeks postoperatively. Morphine equivalent consumption was 36 vs 44 (P = .03), 48 vs 50 (P = .72), 31 vs 28 (P = .57), and 4.7 vs 5.5 (P = .75) in the LT vs ST cohorts at 24 hours, 48 hours, 2weeks, and 6weeks postoperatively. Change in Hgb postoperative day 1 was 2.7 in both groups (P = .975). Postoperative day 1 creatine kinase-MB was 3.7 and 3.0 (P = .30) in LT and ST cohorts. Six-week postoperative KSS Knee and Function scores were 82.4 and 70.5 in LT group vs 80.8 and 72.3 in ST group (P = .61 and P = .63). Postoperative range of motion, LOS, and surgical time were equivalent.ConclusionThis study demonstrates no significant advantage of ST use in primary TKA with respect to opioid consumption, patient-reported pain, KSS scores, LOS, or postoperative Hgb level.     

Comparison of Cruciate-Sacrificing vs Posterior-Stabilized Total Knee Replacement Using a Contemporary Total Knee System

BackgroundThe use of highly conforming polyethylene tibial inserts in cruciate-retaining total knee arthroplasty (TKA) often requires posterior cruciate ligament (PCL) release/sacrifice for balancing (CS TKA). The CS TKA relies on the posterior capsule, collateral ligaments, and articular conformity without a cam or post to achieve stability. Using prospectively collected data we compared clinical outcomes of CS TKA to posterior-stabilized (PS) TKA utilizing a contemporary TKA system.MethodsSixty-nine consecutive CS TKAs were compared to 45 consecutive PS TKAs at 2-year minimum follow-up. CS knees were balanced with the PCL released. Preoperative/postoperative range of motion (ROM), Knee Society Scores (KSS), stair function, and squatting ROM were analyzed.ResultsAt minimum 2-year follow up, CS and PS TKA demonstrated significant improvement in ROM (P < .001), KSS (Pain, P < .001; Function, P < .001), and KSS stair function (P < .001), with no revisions. There was no difference in preoperative to postoperative improvements for passive knee ROM (10° (0°-20°) vs 13° (5°-25°); P = .16), KSS Pain (34 (21-42) vs 38 (24-46); P = .22), KSS Function (35 (30-50) vs 35 (18-50); P = .34), and KSS stair function (10 (10-20) vs 10 (0-20); P = .37) for CS and PS TKA, respectively. CS TKA had higher squatting ROM (P = .02) at minimum 2-year follow-up compared to PS TKA.ConclusionBoth PS and CS TKA provided significant improvement in clinical outcomes, with no differences in passive ROM, KSS, or stair function postoperatively. Our data support that with proper articular conformity and balancing, cruciate-retaining TKA in a PCL-deficient knee (CS TKA) is appropriate. This may be design specific and further prospective randomized studies are needed to corroborate these findings.     

A Prospective Randomized Controlled Trial Comparing Medial-Pivot versus Posterior-Stabilized Total Knee Arthroplasty

BackgroundThe medial-pivot (MP) design for total knee arthroplasty (TKA) aims to restore more natural “ball-and-socket” knee kinematics compared to the traditional posterior-stabilized (PS) implants for TKA. The objective of this study is to determine if there was any difference in functional outcomes between patients undergoing MP-TKA vs PS-TKA.MethodsThis prospective randomized controlled trial consisted of 43 patients undergoing MP-TKA vs 45 patients receiving a single-radius PS-TKA design. The primary outcome was postoperative range of motion (ROM). Secondary outcomes included the Western Ontario and McMaster Universities Arthritis Index, Oxford Knee Score, Knee Society Score (KSS), and radiological outcomes. All study patients were followed-up for 2 years after surgery.ResultsPatients undergoing MP-TKA had comparable ROM at 1 year (114.6° ± 16.3° vs 111.3° ± 17.8° respectively, P = .88) and 2 years after surgery (114.9° ± 15.5° vs 114.9° ± 16.4° respectively, P = .92) compared to PS-TKA. There were also no differences in Western Ontario and McMaster Universities Arthritis Index (26.8 ± 19.84 vs 22.0 ± 12.03 respectively, P = .14), Oxford Knee Score (42.7 ± 8.1 vs 42.3 ± 6.7 respectively, P = .18), KSS clinical scores (82.9 ± 16.96 vs 81.42 ± 10.45 respectively, P = .12) and KSS functional scores (76.2 ± 18.81 vs 73.93 ± 8.53 respectively, P = .62) at 2-year follow-up. There was no difference in postoperative limb alignment or complications.ConclusionThis study demonstrated excellent results in both the single-radius PS-TKA design and MP-TKA design. No differences were identified at 2-year follow-up with respect to postoperative ROM and patient-reported outcome measures.     

Patellar Denervation Reduces Postoperative Anterior Knee Pain After Patellar Resurfacing Total Knee Arthroplasty: A Randomized Controlled Trial

BackgroundThe benefit of patellar denervation (PD) in patellar resurfacing total knee arthroplasty (TKA) is still debatable. This prospective, randomized controlled trial investigated whether circumferential PD should be performed in patellar resurfacing TKA.MethodsA total of 241 patients who underwent unilateral TKA were randomized into PD or non-PD groups. Incidence, intensity, and presentation time of anterior knee pain (AKP) and clinical outcomes were evaluated at 3, 6, 9, 12, 18, and 24 months postoperatively.ResultsThe incidence of AKP was significantly lower in the PD group (6.4% vs 16.2%, P = .032). The intensity of AKP and patient satisfaction scores were significantly better in the PD group at 3 months but not after 3 months. The presentation time of AKP mostly occurs at 3 months after surgery. The Knee Society score, range of motion, Oxford score, patellar score, activity of daily living score, and visual analog scale of overall knee pain were not significantly different between the two groups during the follow-up period.ConclusionGiven that PD can improve AKP and patient satisfaction at an early period postoperatively without jeopardizing clinical outcomes at no additional cost, this inexpensive procedure readily available in nearly every operation room is strongly recommended during primary TKA with patellar resurfacing.     

Unicompartmental Knee Arthroplasty Patients Have Lower Joint Awareness and Higher Function at 5 Years Compared to Total Knee Arthroplasties: A Matched Comparison

BackgroundThe purpose of this study was to evaluate postoperative outcomes at minimum 5-year follow-up in patients following unicompartmental knee arthroplasty (UKA) compared to a matched cohort of total knee arthroplasty (TKA) patients.MethodsPatients who had primarily medial compartment osteoarthritis (OA) who met criteria for medial UKA underwent TKA or medial UKA between 2014 and 2015 at a single institution, matched for age, sex, and body mass index. There were 127 UKAs in 120 patients and 118 TKAs in 116 patients included with minimum 5-year follow-up (range, 6 to 8). Mean age was 69 years (range, 59 to 79) and 71 years (range, 62 to 80) in the UKA and TKA groups, respectively (P = .049).ResultsPatients who underwent UKA had significantly higher mean (±SD) Forgotten Joint Scores (87 ± 20 versus 59 ± 34, P < .001); higher Knee Society Scores (88 ± 14 versus 75 ± 21, P < .001); and lower Numeric Pain Rating Scores (0.8 ± 1.6 versus 1.9 ± 2.2, P < .001). Survivorship free from all-cause revision was 96% (95% CI = 93%-99%) and 99% (95% CI = 97%-100%) at 5 years for TKA and UKA, respectively (P = .52). There were 8 both component revisions in the TKA group within 5 years from the date of surgery and 2 UKA conversions to TKA after 5-year follow-up.ConclusionPatients who have medial compartment OA and underwent UKA had significantly lower joint awareness, decreased pain, improved function, and higher satisfaction compared to matched TKA patients at minimum 5-year follow-up while maintaining excellent survivorship.     

Midterm Outcomes and Survivorship of Anterior Stabilized Versus Cruciate Retaining Bearing in Primary Total Knee Arthroplasty

BackgroundThere has been increasing utilization of ultracongruent bearings with a cruciate retaining (CR) femoral component in primary total knee arthroplasty. The purpose of this study is to compare outcomes and survivorship between an ultracongruent anterior stabilized (AS) and CR bearing.MethodsA retrospective review was performed from 2010 through 2014 of all primary total knee arthroplasties with a single knee systems identical CR femur and AS or CR bearing with minimum 2-year follow-up yielding a study cohort of 3323 patients (4164 knees). Knee range of motion, Knee Society pain scores, Knee Society clinical scores, Knee Society functional scores, and University of California Los Angeles activity scores were evaluated. The need for manipulation under anesthesia (MUA), nonrevision surgery and revisions were assessed.ResultsAS bearing was used in 1471 knees (35%) and CR bearing used in 2693 knees (65%). Mean follow-up was 5.4 years. The AS group had significantly higher improvements in knee range of motion, Knee Society clinical, Knee Society functional, and Knee Society pain scores. MUAs were performed on 120 knees (8.2%) in the AS group compared with 158 knees (5.9%) in the CR group (P = .005). The AS group had significantly less all-cause failure, aseptic failures, revisions for instability, and revisions for isolated polyethylene wear. The 10-year aseptic survival for AS was 98.3% and for 92.3% for the CR group (P = .002).ConclusionThese mid-term results demonstrate the AS bearing had significantly higher improvements in clinical and functional outcomes as well as greater survivorship. Knees in which an AS bearing was used did have a higher incidence of MUA.     

Foot Pain is Common,But Frequently Improves 1 Year After Total Knee Arthroplasty

BackgroundOsteoarthritis frequently affects multiple joints through the lower limbs. This study sought to examine the incidence of foot pain in subjects undergoing total knee arthroplasty (TKA) and determine if foot symptoms improved following surgery.MethodsSix hundred ten subjects undergoing TKA completed patient-reported outcome measures preoperatively, and at 6 and/or 12 months after surgery including the incidence and severity of foot or ankle pain, Knee Injury and Osteoarthritis Outcome Scores (KOOS) Joint Replacement, Oxford Knee Scores (OKS), EQ5D, and satisfaction.ResultsFoot or ankle pain was reported in 45% before, 32% at 6 months, and 36% at 12 months after TKA. Of those with preoperative foot pain, 42% at 6 months and 50% at 12 months reported no foot pain after TKA, and the Visual Analog Scale severity reduced from a mean of 4.0 before to 1.7 after surgery. Those with preoperative foot pain had lower baseline KOOS (P = .001), OKS (P = .001), and more depression/anxiety (P = .010), but experienced equivalent postoperative KOOS, OKS, and satisfaction with surgery, compared to those without foot pain.ConclusionFoot or ankle pain was reported by nearly half of TKA subjects, but resolved after surgery in 50%. Those with preoperative foot pain experienced at least equivalent improvement in knee-related symptoms and mobility compared to those without foot pain. The presence of foot pain should not be a deterrent to TKA.     

Long-Term Functional Outcomes and Quality of Life at Minimum 10-Year Follow-Up After Fixed-Bearing Unicompartmental Knee Arthroplasty and Total Knee Arthroplasty for Isolated Medial Compartment Osteoarthritis

BackgroundThe aim of this study is to compare the long-term functional outcome and quality of life between total knee arthroplasty (TKA) and fixed-bearing unicompartmental knee arthroplasty (UKA) for the treatment of isolated medial compartment osteoarthritis.MethodsBetween 2000 and 2008, a total of 218 patients underwent primary UKA at our tertiary hospital. A TKA group was matched through 1:1 propensity score matching and adjusted for age, gender, body mass index, preoperative knee flexion, and function scores. All patients had medial compartment osteoarthritis. The patients were assessed with the range of motion, Knee Society Knee Score and Knee Society Function Score, Oxford Knee Score, Short Form-36 physical component score (PCS) and mental component score preoperatively, at 6 months, 2 years, and 10 years. Patients’ satisfaction, expectation fulfillment, and minimal clinically important difference were analyzed.ResultsThere were no differences in baseline characteristics between groups after propensity score matching (P > .05). UKA had greater knee flexion at all time points. Although the Knee Society Function Score was superior in UKA by 5.5, 3, and 4.3 points at 6 months, 2 years, and 10 years, respectively (P < .001), these differences did not exceed the minimal clinically important difference (Knee Society Knee Score 6.1). There were no significant differences in the Oxford Knee Score and Short Form-36 physical component score/mental component score. At 10 years, similar proportions of UKA and TKA were satisfied (90.8% vs 89.9%, P = .44) and had expectation fulfillment (89.4% vs 88.5%, P = .46). Between 2 and 10 years, all function scores deteriorated significantly for both groups (P < .01).ConclusionUKA and TKA are excellent treatment modalities for isolated medial compartment osteoarthritis, with similar functional outcomes, quality of life, and satisfaction at 10 years.     

Comparison of Anterior-Stabilized and Posterior-Stabilized Total Knee Arthroplasty in the Same Patients: A Prospective Randomized Study

BackgroundA highly conforming, anterior-stabilized (AS) insert is designed to provide anteroposterior (AP) stability of the posterior-stabilized (PS) insert without a post. The purpose of this study was to compare the static and dynamic stability and function of AS and PS total knee arthroplasty (TKA) in the same patients.MethodsA prospective, randomized controlled trial was performed in 45 patients scheduled to undergo same-day bilateral TKA. One knee was randomly assigned to receive an AS TKA, and the other knee was scheduled for a PS TKA from the same knee system. At 2 years postoperatively, the static AP stability was compared using anterior and posterior drawer stress radiographs at 90° knee flexion. Dynamic AP stability was evaluated using one-leg standing lateral fluoroscopic images throughout the range of motion. Knee function was compared using the Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index score.ResultsAt 2 years postoperatively, there was a significant difference in knee AP laxity at 90° of flexion between the two groups (7.6 ± 3.9 mm in the AS group vs 2.2 ± 2.3 in the PS group, P < .001). However, there were no differences in dynamic AP stability under one-leg standing fluoroscopic lateral images at 30°, 60°, and 90° knee flexion (P = .732, P = .764, and P = .679, respectively). The Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index scores were not significantly different between the two groups (P = .641 and P = .582, respectively).ConclusionDespite the fact that the AS TKA group showed significantly more static posterior displacement than the PS TKA group at 90° of knee flexion, both the AS and PS TKA groups showed similar dynamic stability under weight-bearing conditions and knee function at 2 years postoperatively.     

Evaluating the “Patella-Friendly” Concept in Total Knee Arthroplasty: A Minimum 15-Year Follow-Up Outcome Study Comparing Constant Radius,Multiradius Cruciate-Retaining,and Nonanatomical Cruciate-Retaining Implants

BackgroundPatella-friendly femoral components were developed in order to reduce anterior knee pain and patellofemoral complications in total knee arthroplasty (TKA), but their effect on long-term outcome is still unclear.MethodsWe retrospectively evaluated prospectively collected data from 3 groups consisting of 100 patients (100 knees in each). In group A, the constant radius a-MP, in group B the multiradius cruciate-retaining Genesis II, and in group C the nonanatomic, multiradius, cruciate-retaining AGC TKA was implanted. Patients of all groups were matched for age, gender, side, body mass index, and length of follow-up. Preoperative and postoperative clinical outcome data in the form of Knee Society System (KSS), Short Form-12, Western Ontario and McMaster University Osteoarthritis Index, and Oxford Knee Score were available at regular intervals for groups A and B. For patients of group C, KSS score data were available at the same time intervals. In all groups, the patellofemoral compartment was assessed using the Clinical Patella Score scale. Anterior knee pain, secondary patella resurfacing, implant failure, and radiological outcome were assessed in patients of all groups.ResultsAt 10-year and 15-year follow-up, patients of group A showed statistically significant (s.s.) higher (all P = .000) KSS values as compared to those of groups B and C. At 15-year follow-up, patients of group B showed s.s. higher (P = .001) KSS values as compared to those of group C. At 10-year and 15-year follow up, patients of group A showed s.s. higher (all P = .00) Western Ontario and McMaster University Osteoarthritis Index and Oxford Knee Score values as compared to those of group B. At 15-year follow-up only, patients of group A showed s.s. higher (P = .00) Short Form-12 (physical) values as compared to those of group B. In terms of Clinical Patella Score, patients in group A had s.s. higher values (P = .05) when compared to those of groups B and C. Anterior knee pain was recorded in 4.4% of TKAs in group A, 7.5% in group B, and 17.2% in group C. One (1.1%) patient in group A, 3 (3.25%) in group B, and 7 (8%) in group C underwent secondary resurfacing.ConclusionAnatomical, patella-friendly, constant radius femoral components outperform others in reducing anterior knee pain and patella complications in TKA in which the patellae are left nonresurfaced.     

Impact of Perioperative Pain Control on Knee Range of Motion and Development of Arthrofibrosis Following Primary Total Knee Arthroplasty

BackgroundInadequate pain control following total knee arthroplasty (TKA) has been postulated to negatively impact knee range of motion (ROM). We sought to determine the association between perioperative pain levels and knee ROM at 3-month follow-up or need for manipulation under anesthesia (MUA).MethodsWe retrospectively reviewed 2243 primary TKAs performed from 2002 to 2019 at a single academic center using an institutional total joint registry. Mean age was 68, mean body mass index was 32.8, and 59% were female. Knee ROM was measured preoperatively and 3 months postoperatively. Change in knee ROM, rates of soft tissue contracture, and MUA were assessed in relation to in-hospital 10-point pain visual analog scale (VAS) measurements.ResultsOverall, 44% had improved ROM at 3-month follow-up, 29% had no change in ROM, and 27% had worsened ROM. There was no significant difference in mean VAS scores of patients with improved, unchanged, or worsened ROM postoperatively (3.0 vs 2.8 vs 3.0; P = .068). There was no significant difference in mean VAS scores of patients who developed a soft tissue contracture or required MUA vs those who did not develop these complications (2.7 vs 2.9; P = .24). Similarly, no significant relationship with these outcomes was identified when maximum and discharge VAS scores were analyzed.ConclusionComparable ROM and rates of MUA based on in-hospital pain levels were observed in this large series of primary TKA patients. While significant early pain may limit participation in ROM exercises initially, this does not appear to have a marked impact on ROM-related complications for most patients.Level of EvidenceIII, Therapeutic.     

Combination Effect of High-Dose Preoperative and Periarticular Steroid Injection in Total Knee Arthroplasty. A Randomized Controlled Study

BackgroundPostoperative pain remains a major barrier to a patient’s recovery after total knee arthroplasty (TKA). Periarticular corticosteroids in local infiltration analgesics (LIA) and high-dose intravenous corticosteroids have individually shown to improve pain control after TKA. However, potential interactions between them have not been investigated.This study aims to evaluate any combination effect of both routes of corticosteroids in TKA.MethodsThis is a double-blinded, paired, randomized controlled trial involving 1-stage bilateral TKAs. All received 16 mg of dexamethasone intravenously. One knee was randomized to receive LIA with 40 mg of triamcinolone, while the other knee receives LIA without corticosteroids.For each patient, one knee was affected by intravenous steroids only, while the other was under the combined effect of intravenous and periarticular steroids (IVPAS).Knee pain, Southampton wound scores, and functional knee scores (Knee Society Knee Score and Oxford Knee Scores) were compared between knees of the same patient.ResultsForty-six patients (92 TKAs) were included. IVPAS knees showed significantly lower visual analog scale scores from day 1 to 6 weeks (P < .05) and a larger range of movement from day 2 to 4 (P < .05). IVPAS knees achieved active straight leg raise earlier than intravenous steroids (1.6 vs 2.3 days, P < .05).No differences in Southampton wound scores and functional knee scores for up to 1 year.ConclusionCombining intravenous and periarticular corticosteroids improved pain control and recovery after TKA with no increase in wound complications up to 1 year.     

Cemented Versus Cementless Total Knee Arthroplasty in Obese Patients With Body Mass Index ≥35 kg/m2: A Contemporary Analysis of 812 Patients

BackgroundCemented total knee arthroplasty (TKA) has been shown to have higher failure rates in obese patients, and cementless TKA may provide more durable fixation. This study compared outcomes and survivorship of obese patients undergoing cemented and cementless TKA of the same modern design.MethodsWe identified a consecutive series of 406 primary cementless TKA performed in obese patients with body mass index (BMI) ≥35 kg/m² in 2013-2018. Each case was matched 1:1 with 406 cemented TKA based on age, sex, BMI, bearing surface, and year of surgery. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and Short Form-12 were collected preoperatively, at 6 months and 2 years. Implant survivorship was recorded at mean 4.0 years (range 2.0-7.8).ResultsThere was no difference in mean BMI between the cemented (38.6 ± 3.4 kg/m²; range, 35-60) and cementless cohorts (38.7 ± 3.3 kg/m²; range, 35-54; P = .706). Both groups had similar final postoperative scores and improvement in scores at 2 years. Furthermore, a similar percentage met the minimal clinically important difference (Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, 70.0% vs 71.2%, P = .700; Short Form-12 Physical, 74.1% vs 70.4%, P = .240). Both groups demonstrated high 7-year survivorship free from aseptic revision (99.0% vs 99.5%, P = .665).ConclusionObese patients with BMI ≥35 kg/m² undergoing cementless and cemented TKA of the same modern design had similar outcomes and survivorship at early to mid-term follow-up. Continued surveillance of this high-risk population is necessary.     

Primitive Results After Medial-Pivot Knee Arthroplasties : A Minimum 5-Year Follow-Up Study

Paradoxical anterior movement of the femoral condyles after total knee arthroplasty (TKA) often attenuates the extension mechanism and causes a suboptimal outcome. The medial-pivot implant design aimed to confine anterior movement and emulate physiologic knee kinematics. In our study, a consecutive series of 58 medial-pivot TKA were enrolled with a minimum 5-year follow-up. The Knee Society score improved from 30.5 to 91.1 in objective and from 36.7 to 82.3 in functional scale. The average range of motion was 115.4°. The medial-pivot TKA provided significant improvement in the postoperative range of motion, objective Knee Society score, pain scale, and functional score (P < .05) statistically. A larger sample and longer follow-up are recommended to draw definitive conclusions of this new implant design.     

Coronal Alignment of Fixed-Bearing Unicompartmental Knee Arthroplasty Femoral Component May Affect Long-Term Clinical Outcomes

BackgroundThis study aims to investigate the clinical effects of femoral component coronal alignment in a cohort of fixed-bearing unicompartmental knee arthroplasty with clinical and radiological follow-up of 10 years.MethodsProspectively collected registry data of 264 consecutive, cemented, primary fixed-bearing medial unicompartmental knee arthroplasties performed at a single institution from 2004 to 2007 were reviewed. Femoral component coronal angle (FCCA), tibial component coronal angle, and hip-knee-ankle angle were measured on postoperative radiographs. Patients were grouped into acceptable (AG ≤ 3°) and outlier (OG > 3°) groups according to absolute FCCA. Clinical assessment at 6-month, 2-year, and 10-year follow-up was performed using Knee Society Knee and Function Scores, Oxford Knee Score (OKS), and Short Form-36. Fulfillment of expectations, satisfaction, and implant survivorship was recorded.ResultsThere was no significant difference in demographics, tibial component coronal angle, hip-knee-ankle angle, and sagittal parameters in both groups. The OG had poorer OKS at 10 years and a larger deterioration from 2 to 10 years compared to AG (P = .02). Increase in FCCA was associated with deterioration in 2-year OKS (adjusted ß = 0.23, P = .01), 10-year OKS (adjusted ß = 0.26, P = .03), and 2-year Short Form-36 physical component score (adjusted ß = ?0.44, P = .01). Expectation fulfillment at 2 years was lower in the OG vs the AG (88% vs 100%, P = .03). Both groups had similar 10-year survivorship (99% vs 98%, P = .65).ConclusionsFCCA may affect long-term clinical outcomes, but not short-term clinical outcomes nor 10-year survivorship. Given similar limb alignment, coronal and sagittal component positioning, a larger FCCA was associated with poorer outcomes at 10-year follow-up.