Redefining Indications for Modern Cementless Total Knee Arthroplasty: Clinical Outcomes and Survivorship in Patients >75 Years Old

BackgroundMost studies on cementless total knee arthroplasty (TKA) have excluded patients >75 years due to concerns that older patients have poorer bone mineral density and osteogenic activity. This study compared the midterm outcomes and survivorship of cemented and cementless TKA of the same modern design performed in patients >75 years.MethodsWe identified a consecutive series of 120 primary cementless TKA performed in patients >75 years. Each case was propensity score matched 1:3 with 360 cemented TKA of the same modern design based on age, sex, body mass index, Charlson Comorbidity Index, bilateral procedures, liner type, and year of surgery. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and Short Form-12 (SF-12) were collected preoperatively, at 6 months and 2 years. Implant survivorship was recorded at mean 4.2 years (range, 2.0-7.9).ResultsMean age was 79.0 ± 3.4 years (range, 75-92) in the cemented cohort and 78.9 ± 3.5 (range, 75-91) in the cementless cohort (P = .769). There was no difference in final postoperative scores or improvement in scores at 2 years. The percentage of patients that met the minimal clinically important difference was also similar (KOOS-JR, 68.9% vs 69.2%, P = .955; SF-12 Physical, 71.7% vs 66.7%, P = .299). Seven-year survivorship free from aseptic revision was 99.4% for cemented knees and 100% for cementless knees (log-rank, P = .453).ConclusionPatients over 75 years undergoing cementless or cemented TKA of the same modern design had comparable outcomes and survivorship in the midterm. The theoretical risks of cementless fixation in this age group were not realized in this study.     

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.     

Perioperative and Early Postoperative Comparison of a Modern Cemented and Cementless Total Knee Arthroplasty of the Same Design

Background

Cementless total knee arthroplasty (TKA) designs that incorporate a highly porous, titanium surface have the potential to achieve biologic fixation and improve component survivorship. This study's purpose was to compare perioperative and early postoperative outcomes of a cemented vs cementless TKA of the same design.

Cemented Total Knee Arthroplasty Shows Less Blood Loss but a Higher Rate of Aseptic Loosening Compared With Cementless Fixation: An Updated Meta-Analysis of Comparative Studies

BackgroundThe aim of this study was to update the current evidence on functional outcomes, complications, and reoperation rates between cemented and cementless total knee arthroplasty (TKA) by evaluating comparative studies published over the past 15 years.MethodsThe PubMed, MEDLINE, Scopus, and the Cochrane Central databases were used to search keywords and a total of 18 studies were included. Random and fixed effect models were used for the meta-analysis of pooled mean differences (MDs) and odds ratios (ORs).ResultsA total of 5,222 patients were identified with a mean age of 64.4 ± 9.4 and 63 ± 8.6 years for the cemented and cementless TKA groups, respectively. The mean follow-up was 107.9 ± 30 and 104.3 ± 10 months for the cemented and cementless TKA groups, respectively. Cemented TKA showed a significantly greater postoperative Knee Society Score (MD = ?0.95, 95% CI [?1.57, 0.33], P = .003) and range of motion (MD = ?1.09, 95% CI [?1.88, ?0.29], P = .0007), but no differences in other outcome scores were found. The incidence of periprosthetic joint infection, radiolucent lines, instability, and polyethylene wear was also comparable. Cemented TKA showed less perioperative blood loss (SMD = ?438.41, 95% CI [?541.69, ?35.14], P < .0001) but a higher rate of manipulation under anesthesia (OR = 3.39, 95% CI [1.64, 6.99], P = .001) and aseptic loosening (OR = 1.62, 95% CI [1.09, 2.41], P = .02) than cementless TKA. No differences were found in terms of the reoperation rate.ConclusionWhen cemented and cementless fixations are compared in primary TKA, comparable functional outcomes and reoperation rates can be achieved. Cemented TKA showed less blood loss but a higher rate of manipulation under anesthesia and aseptic loosening.     

Results of Cemented vs Cementless Primary Total Knee Arthroplasty Using the Same Implant Design

Background

Although cemented total knee arthroplasty (TKA) continues to be the gold standard, there are patient populations with higher failure rates with cemented TKAs such as the obese, morbidly obese, and younger active males. Cementless TKA usage continues to increase because of the potential benefits of long-term biologic fixation similar to the rise in cementless total hip arthroplasty. The purpose of this study was to evaluate the clinical and radiographic results of cementless TKA using a novel highly porous cementless tibial baseplate.

A Systematic Review and Meta-Analysis of Non-database Comparative Studies on Cemented Versus Uncemented Femoral Stems in Primary Elective Total Hip Arthroplasty

BackgroundCemented and uncemented femoral stems have shown excellent survivorship and outcomes in primary total hip arthroplasty (THA). Cementless stems have become increasingly common in the United States; however, multiple large database studies have suggested that elderly patients may have fewer complications with a cemented stem. As conclusions from large databases may be limited due to variations in data collection, this study investigated femoral stem survivorship and complication rates based on cement status in non-database studies.MethodsPreferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were utilized to identify articles for inclusion up until June 2021. Included articles directly compared outcomes and complications between patients undergoing primary THA without femoral stem cementing to those with cementing. Studies were excluded if they utilized large databases or consisted of patients with a preoperative diagnosis of trauma.ResultsOf the 1700 studies, 309 were selected for abstract review and nineteen for full-text review. A total of seven studies were selected. Meta-analyses indicated substantial heterogeneity between studies. There were no differences in revision rates (cementless: 5.53% vs. cemented 8.91%, P = .543), infection rates (cementless: 0.60% vs. cemented: 0.90%, P = .692), or periprosthetic fracture rates (cementless: 0.52% vs. cemented: 0.51%, P = .973) between groups.ConclusionThere is scarce literature comparing outcomes and complications between cemented and cementless femoral stems in primary elective THA without utilizing a database methodology. In our study, there were no differences in complications detected on meta-analyses. Given previous findings in database studies, additional high-quality cohort studies are required to determine if selected patients may benefit from a cemented femoral stem.     

Does Body Mass Index Influence the Outcomes and Survivorship of Modern Cementless Total Knee Arthroplasty?

BackgroundHigher body mass index (BMI) has been associated with higher rates of aseptic loosening following cemented total knee arthroplasty (TKA). However, there is a paucity of evidence on the effect of BMI on the durability of modern cementless TKA. We aimed to assess the association between BMI and clinical outcomes following cementless TKA and to determine if there was a BMI threshold beyond which the risk of revision significantly increased.MethodsWe identified 1,408 cementless TKAs of a modern design from an institutional registry. Patients were classified into BMI categories: normal (n = 136), overweight (n = 476), obese class I (n = 423), II (n = 258), and III (n = 115). The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and 12-item Short Form Health Survey scores were collected preoperatively and 2 years postoperatively. Survivorship was recorded at minimum 2 years (range, 24 to 88 months). BMI was analyzed as a continuous and categorical variable.ResultsThe improvement in patient-reported outcomes was similar across the groups. Thirty four knees (2.4%) were revised and 14 (1.0%) were for aseptic failure. Mean time-to-revision was 1.2 ± 1.3 years and did not differ across BMI categories (P = .455). Survivorship free from all-cause and aseptic revision was 97.1% and 99.0% at mean 4 years, respectively. Using Cox regression to control for demographics and bilateral procedures, BMI had no association with all-cause revision (P = .612) or aseptic revision (P = .186). Receiver operating characteristic curve analysis found no relationship between BMI and revision risk (c-statistic = 0.51).ConclusionBMI did not influence functional outcomes and survivorship of modern cementless TKA, possibly due to improved biological fixation at the bone-implant interface. Longer follow-up is necessary to confirm these findings.     

Survivorship of 500 Cementless Total Knee Arthroplasties in Patients Under 55 Years of Age

BackgroundWith respect to survivorship following total knee arthroplasty (TKA), joint registries consistently demonstrate higher revision rates for both genders in those aged less than 55 years. The present study analyzed the survivorship of 500 cementless TKAs performed in this age group in a high-volume primary joint unit where cementless TKA has traditionally been used for the majority of patients.MethodsThis was a retrospective review of 500 consecutive TKAs performed in patients aged less than 55 years between March 1994 and April 2017. The primary outcome measures for the study were survivorship and all-cause revisions. Secondary outcome measures included nonrevision procedures, clinical, functional, and radiological outcomes.ResultsAn all-cause survival rate of 98.4% and an aseptic survival rate of 99.2% at a median time of 10.7 years (interquartile range 7.3-14.9, range 0.2-27.7) were found. Four patents were revised for infection, 2 for stiffness, 1 for aseptic loosening of the tibial component, and 1 for a patella that was resurfaced for anterior knee pain. Thirty four patients (6.8%) had a nonrevision procedure with manipulation under anesthetic accounting for 27. On a multivariate analysis, preoperative range of motion and female gender were negatively associated with postoperative range of motion (P < .001 and P = .003, respectively). Sixty seven patients (17.3%) had radioluscent lines and on a multivariate analysis, there were no significant predictors of radiolucent lines.ConclusionCementless TKA in the young patient can achieve excellent clinical and functional outcomes. At a median of 10.7 years, aseptic revision rates are exceptionally low at 0.8% for the entire cohort.     

Functional Outcomes are Comparable Between Posterior Stabilized and Cruciate-Substituting Total Knee Arthroplasty Designs at Short-Term Follow-up

BackgroundPosterior stabilized (PS) polyethylene inserts have been shown to have excellent long-term functional results following total knee arthroplasty (TKA). A cruciate-substituting (CS) design has been introduced to minimize bony resection and eliminate concerns regarding wear on the PS post. The purpose of this study is to compare the outcomes of patients who underwent TKA using either a PS or CS insert.MethodsWe reviewed a consecutive series of 5970 patients who underwent a cruciate-sacrificing TKA and received either a PS (3,314) or CS (2,656) polyethylene liner. We compared demographics, Knee Injury and Osteoarthritis Outcome Score Jr (KOOS Jr), Short-Form 12 (SF-12) scores, and revision rates between the groups at a minimum 2 years followup. A multivariate regression was performed to identify the independent effect of design on functional outcomes.ResultsRevision rates between the groups were comparably low (0.35% for PS vs 0.51% for CS, P = .466) at an overall mean follow-up of 43 months. Patients in the PS cohort had statistically higher KOOS Jr scores at 2 years (69.8 vs 72.9, P < .001). Multivariate regression analysis found CS patients to have lower postoperative KOOS Jr scores (estimate ?2.26, P = .003), and less overall improvement in KOOS Jr scores (estimate ?2.42, P = .024) than PS patients, but neither was a clinically significant difference.ConclusionPatients who undergo TKA with a CS polyethylene insert have comparable functional outcomes and revision rates to those with a PS design at short-term follow-up. Longer follow-up is needed to determine whether CS can match the outstanding track record of PS TKA.     

Increased Survivorship of Cementless versus Cemented TKA in the Morbidly Obese. A Minimum 5-Year Follow-Up

Background

Total knee arthroplasty (TKA) in the morbidly obese patients can be challenging with an increased risk of complications. Studies have shown increased aseptic failures with well-aligned cemented TKAs in the obese patient. The purpose of this study is to determine if TKA in the morbidly obese (body mass index [BMI] ≥ 40) using cementless implants would demonstrate improved results and survivorship compared to cemented TKA at a minimum 5-year follow-up.

Comparison of Expectations and Outcomes in Rheumatoid Arthritis Versus Osteoarthritis Patients Undergoing Total Knee Arthroplasty

BackgroundWe hypothesized that patients undergoing primary total knee arthroplasty (TKA) for rheumatoid arthritis (RA) would have different preoperative expectations compared to osteoarthritis (OA) patients, and that postoperative satisfaction would correlate with specific postoperative pain and functional domains.MethodsThis is a retrospective cohort study of RA patients matched based on age, gender, American Society of Anesthesiologists score, and Charlson Comorbidity Index score 1:2 with OA patients (76 RA, 152 OA) who underwent primary TKA. The Hospital for Special Surgery Knee Replacement Expectations Survey, Visual Analogue Scale for Pain (VAS), Knee injury and Osteoarthritis Outcome Score (KOOS), and the Short Form-12 (SF-12) were compared at baseline and at 2 years postoperatively. Minimum clinically important differences (MCIDs) were calculated for KOOS and SF-12 subdomains.ResultsPreoperatively, RA patients had lower expectations, worse VAS Pain, and worse KOOS Pain, Symptoms, and Activities of Daily Living (P < .05). However, at 2 years, RA patients had significantly larger improvements in VAS (P = .01) and these 3 KOOS subdomains (P < .05), achieving comparable absolute scores to OA patients. Overall, 86.1% of RA and 87.1% of OA patients were either somewhat or very satisfied with their TKA. Patient satisfaction correlated with VAS Pain and KOOS outcome scores in both groups. RA and OA patients had high rates of achieving MCID in SF-12 physical component scores and all 5 KOOS subdomains. A higher proportion of RA patients achieved MCID in KOOS Symptoms (98.4% vs 77.2%, P < .001).ConclusionRA patients had lower baseline expectations compared to OA patients. However, RA patients had greater improvements in KOOS and SF-12 subdomains, and there was no difference in satisfaction compared to OA patients after TKA.     

Despite Improved Survivorship of Uncemented Fixation in Total Knee Arthroplasty for Osteoarthritis,Cemented Fixation Remains the Gold Standard: An Analysis of a National Joint Registry

BackgroundTotal knee arthroplasty (TKA) numbers are increasing worldwide. While cement fixation for both femoral and tibial components is commonly used, alternatives include hybrid and uncemented TKAs. This study aimed to evaluate survivorship, revision rates, and patient-reported outcomes for cemented, hybrid, and uncemented TKAs using New Zealand Joint Registry (NZJR) data.MethodsNZJR data relating to all TKAs performed during the 19 years up to the end of December 2017 were analyzed. Outcomes were assessed using prosthesis survivorship data (including reasons for revision) and Oxford scores at 6 months, 5 years, and 10 years postoperatively.ResultsA total 96,519 primary TKAs were performed during the period examined. Most (91.5%) were fully cemented with 4.8% hybrid and 3.7% uncemented. Mean Oxford scores at 6 months were highest in cemented and lowest in uncemented TKAs (P < .001). However, this was not clinically significant. There was no difference at 5 or 10 years. Ten-year survival rates were 97%, 94.5%, and 95.8% for cemented, uncemented, and hybrid TKAs, respectively. Revision rates were 0.47, 0.74, and 0.52 per 100 component years for cemented, uncemented, and hybrid prostheses, respectively. The revision rate for uncemented prostheses compared with cemented was higher (P < .001). When stratified by age group, there were differences in survival rates between cemented and uncemented groups (P = .001) and hybrid and uncemented groups (P = .038) in patients aged <55 years; between cemented and uncemented groups in those aged 55-64 years (P = .031); and between cemented and hybrid groups in those aged >75 years (P = .004).ConclusionUncemented TKAs had similar patient-reported outcomes but higher revision rates and worse survivorship compared with hybrid or fully cemented TKAs.     

What are the Outcomes After Primary Total Hip and Knee Arthroplasty in Patients With Prior Cerebrovascular Accidents?

BackgroundFor patients who have a history of cerebrovascular accident (CVA) with neurological sequelae undergoing primary total hip arthroplasty (THA) and total knee arthroplasty (TKA), we sought to determine mortality rate, implant survivorship, complications, and clinical outcomes.MethodsOur total joint registry identified CVA sequelae patients undergoing primary THA (n = 42 with 25 on affected hip) and TKA (n = 56 with 34 on affected knee). Patients were 1:2 matched based upon age, sex, body mass index, and surgical year to a non-CVA cohort. Mortality and implant survivorship were evaluated via Kaplan-Meier methods. Clinical outcomes were assessed via Harris Hip scores or Knee Society scores . Mean follow-up was 5 years (range, 2-12).ResultsFor CVA sequelae and non-CVA patients, respectively, the 5-year patient survivorship was 69 versus 89% after THA (HR = 2.5; P = .006) and 56 versus 90% after TKA (HR = 2.4, P = .003). No significant difference was noted between groups in implant survivorship free from any reoperation after THA (P > .2) and TKA (P > .6). Postoperative CVA occurred at an equal rate in CVA sequelae and non-CVA patients after TKA (1.8%); none after THA in either group. The magnitude of change in Harris Hip scores (P = .7) and Knee Society scores (P = .7) were similar for CVA sequelae and non-CVA patients.ConclusionComplications, including the risk of postoperative CVA, implant survivorship, and outcome score improvement are similar for CVA sequelae and non-CVA patients. A 2.5-fold increased risk of death at a mean of 5 years after primary THA or TKA exist for CVA sequelae patients.     

Prior Manipulation under Anesthesia is a Predictor of Contralateral Manipulation in Staged Bilateral Total Knee Arthroplasty

BackgroundThere are many risk factors for arthrofibrosis and manipulation under anesthesia (MUA) following total knee arthroplasty (TKA). However, no study has elucidated whether a history of MUA increases the risk of contralateral MUA in patients undergoing staged bilateral TKA.MethodsA retrospective review of an institutional database of TKAs was performed. All patients aged ≥18 years who underwent primary staged bilateral TKAs were screened for inclusion. Staged bilateral TKAs were viewed as 2 distinct events based on the temporal order in which they occurred: TKA#1 (occurred first) and TKA#2 (occurred second). Following TKA#1, patients were split into 2 groups: those who underwent MUA (Group MANIP) and those who did not (Group NO MANIP). The subsequent risk of undergoing MUA following TKA#2 was then assessed and compared between the 2 groups. Chi-squared tests were used for comparison.ResultsA total of 5,330 patients who underwent primary uncomplicated staged bilateral TKAs (10,660 knees) during the study period were identified. Overall, 2.1% of patients underwent MUA following TKA#1 and 1.9% of patients underwent MUA following TKA#2. In the MANIP group, 21.4% of patients underwent MUA following TKA#2, while only 1.5% underwent MUA in the NO MANIP group. This 14.3-fold increase in the risk of MUA in the MANIP group following TKA#2 was statistically significant (21.4% vs 1.5%, absolute risk reduction = 19.9%, relative risk reduction = 93.0%, P < .0001).ConclusionPatients who undergo MUA during the first TKA of a staged bilateral TKA are 14.3 times more likely to undergo a subsequent MUA than those who did not undergo MUA following their first TKA.     

Hybrid fixation versus full-cemented or full-cementless fixation in total knee arthroplasty: Systematic review and meta-analysis of comparative studies

ObjectiveHybrid fixation is one alternative to full-cemented fixation in total knee arthroplasty (TKA) with theoretical advantages. Hybrid fixation may offer the advantages of cementless femoral fixation, while also avoiding the problem of tibial loosening in full-cementless TKA. The purpose of the study is to determine whether hybrid TKA may perform comparably to or better than full-cemented and full-cementless TKA.MethodsWe searched the MEDLINE, EMBASE and Cochrane Library databases through September 2018 for randomized controlled trials and observational studies comparing outcomes of hybrid versus full-cemented or full-cementless fixation techniques. Outcomes of interest included aseptic loosening, overall reoperation rate, infection, radiolucent lines and operating time. Data were pooled with the Mantel–Haenszel random effects model.ResultsWe included 14 studies with follow-up ranging from 2.7 to 9.6 years in our quantitative analysis, of which 7 studies compared hybrid fixation with full-cemented TKA and another 7 compared hybrid fixation with full-cementless TKA. Combined data revealed that the hybrid fixation group had a similar rate of aseptic loosening compared with cemented (P = 0.19) and cementless (P = 0.49) groups. There was no difference with respect to other outcomes, including overall reoperation rate, infection, radiolucent lines and operating time between groups.ConclusionHybrid, cementless and cemented TKAs have comparable mid-term results as it pertains to aseptic loosening, overall reoperation, infection, radiolucent lines and operating time. Further comparative studies are needed to investigate these potential effects over the long-term.     

Impact of Component Alignment and Soft Tissue Release on 2-Year Outcomes in Total Knee Arthroplasty

BackgroundThe objective of this study was to investigate the impact of alignment and soft tissue release on patient outcomes following total knee arthroplasty (TKA).MethodsIn a multicenter study, soft tissue releases during TKA were prospectively documented in 330 robotic-assisted TKAs. Knee Injury and Osteoarthritis Outcome Scores (KOOS) were captured postoperatively. Delphi analysis was used to determine inlier and outlier component alignment boundaries: Tibia Coronal (TC): ±3°, Femur Coronal (FC): ±3°, Femoral Axial (FA): 3°Int-6°Ext, Hip-Knee-Ankle (HKA): 3°Val-4°Var, and Tibiofemoral Axial (TFA): 3°Int-6°Ext. Kruskal–Wallis analysis of variance tests were used to compare groups.ResultsNo significant differences were found between any individual or grouped inlier and outlier alignment criterion and KOOS at any timepoint. Outlier alignment frequencies were: TC: 0%, FC: 12%, FA: 8%, HKA: 9%, TFA: 8%, and Any: 23%. Soft tissue releases were performed in 18% of cases. Knees with soft tissue releases reported significantly worse KOOS scores at: 6M: Symptoms (80.0 versus 75.3, P = .03), activities of daily living (ADL) (86.2 versus 80.8, P = .030), quality of life (70.1 versus 60.9, P = .008), 12M ADL (90.0 versus 85.1, P = .023), and 24M ADL (91.9 versus 87.2, P = .016). A higher proportion of patients achieved Minimal Clinically Important Difference for pain at 6 months for those having no releases versus released (92.3% versus 81.0%, P = .021). No significant associations were found between preoperative deformity and preoperative or postoperative KOOS.ConclusionThe addition of soft tissue releases after bony cuts is associated with worse KOOS scores out to 2 years and was more prevalent in knees with worse deformity, while no such association was found for alignment.     

Do Knee Osteoarthritis Patterns Affect Patient-Reported Outcomes in Total Knee Arthroplasty? Results From an International Multicenter Prospective Study With 3-Year Follow-Up

BackgroundThe aim of this multicenter study is to answer (1) Does patellofemoral osteoarthritis (OA) affect preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) scores in total knee arthroplasty (TKA)? and (2) Do different OA patterns affect preoperative and postoperative KOOS scores in TKA?MethodsThis international, multicenter prospective study examined 384 TKA patients. Compartmental OA was divided into (1) medial, (2) medial + patellofemoral, (3) lateral, (4) lateral + patellofemoral, (5) medial + lateral (bicompartmental), and (6) medial + lateral + patellofemoral (tricompartmental), based on preoperative anterior-posterior and lateral ± skyline radiographs with Kellgren-Lawrence grade III-IV and joint space width <2.5 mm. KOOS was collected preoperatively, 1 year postoperatively, and 3 years postoperatively. Higher KOOS score represented better clinical state, for example, higher KOOS Pain score indicated less pain.ResultsPatellofemoral OA had no effect on preoperative KOOS scores (P > .15). Compared to medial ± patellofemoral OA patients, bicompartmental/tricompartmental OA patients had less preoperative pain (KOOS Pain 7.4, P = .03) and higher daily function (KOOS-ADL [Activities of Daily Living] 7.1, P = .05), and higher 1-year postoperative daily function (KOOS-ADL 9.2, P = .03) and sports activity (KOOS Sports & Recreation Function 15.0, P = .04), while lateral ± patellofemoral OA patients had more symptoms (KOOS-Symptoms 7.0, P < .01), more pain (KOOS-Pain 7.5, P = .01), lower daily function (KOOS-ADL 9.3, P < .01), and lower quality of life (KOOS-QOL 9.0, P = .04), at 3 years postoperatively.ConclusionPatellofemoral OA does not affect medial ± lateral OA patients’ preoperative KOOS scores, challenging the importance of patellofemoral OA in TKA. Lateral ± patellofemoral OA patients have lower postoperative KOOS scores than medial/more progressed compartmental OA patients, indicating that patients with less common OA patterns present with unique surgical challenges. Further development of indications for and correct timing of TKA surgery in different patient subgroups is needed.     

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.     

The Influence of Dorr Type and Femoral Fixation on Outcomes Following Total Hip Arthroplasty for Acute Femoral Neck Fractures: A Multicenter Study

BackgroundThe American Academy of Orthopaedic Surgeons guidelines report moderate evidence for cementing femoral stems for hip fractures, mainly derived from hemiarthroplasty literature. This is the first large, nonregistry study examining the influence of femoral fixation, implant type, patient characteristics, and radiographic factors on outcomes after total hip arthroplasty (THA) for acute femoral neck fractures.MethodsA multicenter retrospective study was performed of 709 THA cases (199 cemented, 510 cementless) for femoral neck fractures from 2006 to 2020 at three large academic institutions. Demographics, perioperative characteristics, and radiographs were reviewed. Kaplan-Meier survivorship curves were generated for multiple outcomes. Univariate and multivariate analyses were performed with P ≤ .05 denoting significance.ResultsCementless stems had a higher all-cause aseptic femoral revision rate (5.1 versus 0.5%, P = .002) and periprosthetic femoral fracture rate (4.3 versus 0%, P = .001). Each successive Dorr type had a higher fracture rate with cementless implants: 2.3%, 3.7%, and 15.9% in Dorr A, B, and C, respectively (P < .001). Logistic regression analyses confirmed that cementless stems (P = .02) and Dorr C bone (P = .001) are associated with periprosthetic fractures; collared implants and prophylactic cables did not protect against fractures. There was no difference in rates of dislocation, septic revision, or mortality between groups.ConclusionCementless stems during THA for femoral neck fractures have a higher aseptic femoral revision rate, specifically for periprosthetic fractures. Dorr C bone was particularly prone with an alarmingly high fracture rate. All fractures occurred in cementless cases, suggesting that cemented stems may minimize this complication.Level of EvidenceIII.     

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.