Background Stiffness after knee arthroplasty is commonly treated with manipulation under anesthesia (MUA). Previously identified predictors of MUA include younger age, Black race, low body mass index, diabetes, tobacco use, and prior nonarthroplasty knee surgery. Whether these factors persist in a healthcare system with minimal financial barriers remains unclear. We evaluated rates and predictors of MUA in the U.S. Military Health System (MHS). Methods This retrospective cohort study queried the MHS Data Repository for patients undergoing primary total knee arthroplasty, revision total knee arthroplasty (rTKA), or unicompartmental knee arthroplasty (UKA) from 2016 to 2022 using Current Procedural Terminology. Minimum follow-up was 6 months. Logistic regression evaluated associations between patient factors and MUA. Results A total of 8223 knee arthroplasties were identified in 7164 patients. Mean age was 62 ± 9 years; active-duty patients (n = 502) averaged 48 ± 7 years. MUA rates were 4.6% after TKA (315/6833), 2.1% after rTKA (19/885), and 1.4% after UKA (7/505). Protective factors included older age (odds ratio [OR] 0.96/year, P < .0001), UKA (OR 0.23, P = .0002), and rTKA (OR 0.41, P = .0002). Risk factors included Black race (OR 1.90, P < .0001), prior nonarthroplasty knee surgery (OR 1.56, P = .04), and diabetes (OR 1.40, P = .01). Tobacco use and active-duty status were not significant predictors. Mean follow-up was 3 years. No statistically significant association between MUA and revision arthroplasty was detected. Conclusions Previously identified risk factors, including younger age, Black race, diabetes, and prior knee surgery, remained associated with MUA within the MHS. Active-duty status was not associated with increased MUA risk.
Background Prior authorization (PA) in total joint arthroplasty (TJA) can challenge patients and providers. This study examines how site-of-care decisions impact outcomes by comparing patients approved for inpatient vs outpatient surgery, with the goal of improving PA processes and guiding best practices. Methods PA data from primary TJA (n = 1030) cases were retrospectively collected at a tertiary academic center from June to December 2022. Variables included demographics, comorbidities, American Society of Anesthesiologists (ASA) score, insurance type, submission method, and site-of-care request. Cohorts were analyzed by site-of-care determination, time to decision, length of stay, and complications. Statistical analysis used Chi-square and t-tests. Results PA was required for 81% (n = 736) of inpatient TJA cases, with a 90% (n = 661) approval rate. Approved inpatient cases were associated with older age (64.3 ± 10, P = .04), women (n = 464, 74%, P < .01), ASA class 3-4 (n = 334, 53%, P < .01), and higher body mass index (33.2 ± 6.7 kg/m2, P < .01). Thirty percent of requests used noninternet methods, with Managed Medicare patients accounting for 53% (n = 343). Median time to decision was 4 days (range 0-37). Only 30% of patients denied inpatient admission achieved same-day discharge. No significant differences in postoperative complications were observed. Conclusions PA significantly influences TJA patients and providers, with most cases requiring PA. Approval was influenced by site-of-care request, age, sex, health status, and insurance type. Frequent noninternet submissions and prolonged decision times identify areas for improvement overall.
Background Prosthetic joint infection (PJI) involves a significant mortality risk, with 26-30% of patients dying within 5 years. Current risk assessment tools offer limited prognostic accuracy for PJI patients. This study aimed to develop a prognostic model for 5-year all-cause mortality after PJI using age and frailty assessments. Methods We conducted a retrospective cohort study using TriNetX electronic health record data from 13,371 PJI patients diagnosed before 2021. We developed a 30-item Accumulated Frailty Index (AFI-Core30) that incorporates comorbidities, physiologic deficits, medications, and functional status. Generalized additive modeling was used to predict 5-year mortality, with 80% of data allocated for training and 20% for validation. Model performance was assessed using discrimination metrics and calibration techniques. Results The mean patient age was 63.1 ± 11.4 years, with an overall 5-year mortality rate of 13.1%. Both AFI-Core30 and age independently predicted mortality (odds ratio per 0.1 AFI increase = 1.84, 95% confidence interval: 1.74-1.95, P < .001; odds ratio per 10-year increase in age = 1.65, 95% confidence interval: 1.56-1.74, P < .001). The model demonstrated good discrimination (validation area under the receiver operating characteristic curve 0.712) and excellent calibration (Brier score 0.103). Mortality risk ranged from 2.6% in young, nonfrail patients to 50.4% in older, frail individuals. Conclusions This validated prognostic model offers the first large-scale, frailty-based tool for predicting mortality in PJI patients. The framework allows for evidence-based risk assessment and personalized treatment planning, shifting PJI prognostication from subjective judgment to objective risk measurement for better clinical decision-making.
Background A hearing conservation program is recommended by the Occupational Safety and Health Administration for prolonged exposure exceeding 85 dB. Arthroplasty surgeons often experience levels above this threshold. There is a paucity of literature regarding sound exposure for all arthroplasty operating room (OR) personnel. This study directly assesses and compares sound exposure levels for all OR personnel in total joint arthroplasty. Methods Sound data were recorded for 20 total hip arthroplasty (THA) and 20 total knee arthroplasty (TKA) cases. Recording devices collected sound data for the 5 primary OR roles—primary surgeon, first assistant, surgical technologist, anesthesia staff, and circulating nurse. T-test and analysis of variance were completed to compare between case type and OR personnel, respectively. Results Average sound level exceeded 85 dB for the primary physician in hip and knee arthroplasty. Sound exposure in THA commonly exceeded that of TKA. The primary surgeon experienced significantly higher average sound level than all other OR personnel in TKA and THA (P < .01). The primary surgeon also experienced a significantly higher percentage of total time with sound exceeding 90 dB relative to other OR personnel (P < .0001). Conclusions All total joint arthroplasty OR personnel, including anesthesia and nursing, may be exposed to some degree of potentially dangerous sound. This risk is most notable for direct operative staff, and significantly higher for the primary surgeon. Our data suggests hearing protection is indicated by the Occupational Safety and Health Administration standards for the primary surgeon; however, all OR personnel would likely benefit based on our measured exposures.
Background There have been several reports of metaphyseal debonding of hydroxyapatite (HA)-coated cementless quadrangular taper femoral stems leading to revisions for aseptic loosening. This study aimed to assess the characteristics and risk factors of this type of revision. Methods A single-center cohort of total hip arthroplasty patients who received a cementless HA-coated Corail stem between 2006-2023 was identified. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and confidence intervals (CIs) of the association between implant/patient characteristics and revision for aseptic loosening. Dorr type and canal fill was assessed for all patients undergoing revision. Results The study identified 3876 patients leading to 27 aseptic loosening revisions and 91 other revisions. Stem size <10 was associated with aseptic loosening, HR = 9.1 (95% CI 3.4-24.2). Taller patients, metal-on-metal bearings, and collarless stems were all associated with higher risk. Half of patients with aseptic loosening had Dorr type A femurs and half had undersized stems. Initial radiographs showed little to no radiolucency for these patients. Radiolucency increased after several postoperative years. Only 20% of patients with other reasons for revision had undersized stems and these patients exhibited less radiolucency. Conclusions Smaller, undersized HA-coated cementless quadrangular taper stems appear to be at significantly increased risk of aseptic loosening in midterm follow-up. Surgeons using quadrangle tapered cementless stems should be cautious when broaching suggests a stem size smaller than preoperative templating recommended, especially in patients with narrow femoral canals and should consider using a collar whenever possible with this stem design.
A 62-year-old man underwent a right total hip arthroplasty in 2006, during which the trial femoral head dislocated intraoperatively and migrated into the pelvis. Retrieval of the trial component was attempted during the index surgery but was unsuccessful. After disclosure to patient and family and extensive discussion regarding all possible management options, the decision was made to leave the component in situ with careful monitoring of the patient. After nearly 20 years, the patient reports no symptoms and shows no adverse effects of the retained trial head. To our knowledge, this is the longest follow-up reported on a patient with retained intrapelvic trial femoral head after total hip arthroplasty and suggests that retention may be a viable option if this unfortunate complication occurs.
Background This study determined the prevalence of glucagon-like peptide-1 (GLP-1) use before total joint arthroplasty (TJA), measured weight loss of patients on GLP-1s, and evaluated if GLP-1s were associated with outcomes. Methods We identified 6482 patients (2990 hips; 3492 knees) who had primary TJAs between 2019 and February 2023. The mean age was 67 years, 50% were female, and 12% had a body mass index ≥40 kg/m2. Univariable and multivariable models evaluated outcomes. Mean follow-up was 3 years. Results The prevalence of GLP-1s before TJA was 3%, increasing from 2% in 2019 to 5% in 2022. The mean preoperative weight change on GLP-1s was −9 pounds (range, −110 to +36 pounds). Among patients taking GLP-1s, 19% lost ≥20 pounds prior to surgery, and the mean body mass index change was −1.4 kg/m2 (range, −16.3 to 6.2 kg/m2). In univariable analyses, GLP-1 use was not associated with revisions (P = .35), reoperations (P = .09), or complications (P = .23). In multivariable analyses, GLP-1s were not associated with revisions (P = .66), reoperations (P = .34), or complications (P = .85). There was no difference in the risk of a 90-day postoperative emergency department visit between those on GLP-1s vs not on those medications (odds ratio, 1.5; P = .07). Conclusions The prevalence of preoperative GLP-1s before TJA increased from 2% in 2019 to 5% in 2022, and preoperative weight change on GLP-1s varied considerably. GLP-1s were not associated with decreased postoperative risks but investigational GLP-1s before TJA require further study. Level of Evidence Level III.
Background Although corrective osteotomies, hip resurfacing, or custom implants can be used to treat patients with femoral shaft deformity (FSD), these have some limitations. This study aims to assess the clinical and radiological results of a short-stem design in patients with and without FSD. Methods A retrospective analysis of a prospectively collected database of patients with FSD treated with a short femoral stem was conducted over a minimum follow-up period of 1-year. Data were collected for 16 patients with FSD. From a cohort of 451 patients without deformity, propensity score matching was used to form a 32-patient control group. Clinical results were evaluated with the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and the Harris Hip Score preoperatively, and at 1 month, 3 months, 1-year, and every 2 years thereafter. The stability of the fixation was evaluated using Engh’s criteria. Results The mean follow-up was 6.87 years. Surgical time was longer in the deformity group (98.7 vs 79.3 minutes; P = .012). There was no intraoperative complication related to the femoral stem, and no aseptic loosening was identified at the time of the latest follow-up. One failure was observed in the deformity group, related to a broken stem at 7 years of follow-up. At 1 year, considerable improvements in Harris Hip Score and WOMAC scores were obtained, but no statistically significant differences were detected between the groups. Conclusions The short-stem design analyzed can be considered a viable option in patients with FSD, with similar results as in patients without deformity. However, longer-term follow-up is required.
Background:Contemporary performance of revision hemispherical shells in acetabular revision total hip arthroplasty (rTHA) remains limited. This study evaluated survivorship free from revision for aseptic acetabular loosening, all-cause revision, and all-cause reoperation, as well as dislocation rate and patient-reported outcomes (PROMs) following aseptic rTHA with modern, highly-porous, revision acetabular components. Methods:We identified 127 patients (mean age 66, mean body mass index 27, 57% female) who underwent aseptic rTHA with hemispherical shells from 2016 to 2022 with minimum 2-year potential follow-up. Paprosky defects type was I in 20%, II in 70%, and III in 10%. Cases using augments or cages were excluded. A posterolateral approach was used in 98% of patients, and 21% of patients underwent concomitant femoral revision. A mean of 3 (range, 0-5) screws were used. Liners included dual mobility (n = 94), elevated (n = 15), neutral (n = 12), constrained (n = 4), and offset (n = 2). Kaplan-Meier survivorship analysis assessed time-to-event outcomes. Results:At 2 years, survivorship free from revision for aseptic acetabular loosening was 97%, and free from all-cause revision was 94%. Revision indications included dislocation (n = 4), aseptic loosening (n = 2), periprosthetic joint infection (n = 1), and metallosis (n = 1). Dislocation occurred in 7 patients (6%). At 2 years, there was a median 21.4-point increase in the Hip Injury and Osteoarthritis Outcome Score for Joint Replacement (P < .001). Conclusions:Modern, highly-porous revision hemispherical shells with multiple screw fixation have excellent 2-year survivorship free from aseptic loosening (97%) but modest dislocation rate (6%). These results support the use of contemporary hemispherical shells but highlight the need for instability prevention.
Highly cross-linked polyethylene (HXLPE) is commonly used in knee arthroplasty due to its improved wear resistance. However, increased crosslinking reduces the tensile strength and fatigue resistance of polyethylene, which may be detrimental in high shear environments such as a cemented patellar button. In patellofemoral arthroplasty (PFA), patellar components are exposed to substantial shear stresses, which may predispose polyethylene components to fatigue-related failure and peg shear. We report a case series of patellar component failures in PFA, including several HXLPE patellar buttons demonstrating peg fracture and loosening, as well as 1 ultra-high molecular weight polyethylene patellar button with a similar failure pattern. To our knowledge, these represent the first reported cases of HXLPE patellar component peg shear in PFA, a complication previously described only in the setting of total knee arthroplasty.
Intrapelvic migration of the acetabular component following hip arthroplasty is a rare but challenging complication with significant risks, including adjacent organs and vascular injury. In the current literature, managing this complication has focused on removing the migrated failed implant first, followed by revision of the prosthesis. We present the case of a patient who sustained an early intrapelvic migration of the acetabular cup and screws following total hip arthroplasty. A unique two-stage approach was employed: acetabular reconstruction using bone graft, a Kerboull cross-plate, and a dual-mobility cup was performed first; the migrated cup and screws were safely removed subsequently through a retroperitoneal approach. The described technique highlights the efficacy of a staged surgical intervention, starting with the acetabular reconstruction, followed by delayed removal of the retained intrapelvic implant.
Background:Hip-specific patient-reported outcome measures (PROMs) are used to assess patient recovery after total hip arthroplasty (THA), but their efficacy in patients with prior lumbar spinal fusion (LSF) remains less clear. This study evaluated the discordance between improvements in hip-specific PROMs and persistent lumbar-related symptoms in patients with prior LSF who underwent THA. Methods:We performed a single-center retrospective study of patients with prior LSF who underwent THA from January 2015 to October 2025. Multiple PROMs, including PROMIS-10, HOOS Jr., University of California Los Angeles Activity Score, and EQ-5D, were analyzed using paired Wilcoxon signed-rank tests. Lumbar-related symptoms were assessed by structured chart review and treated as binary variables. Results:Overall, 54 total cases from 47 unique patients were identified, including 41 total cases in the primary cohort. Paired baseline and 3-month PROMs were available for 18 total cases. Significant improvements occurred in HOOS Jr. (+27.66, P < .001), PROMIS pain (-3.06, P < .01), PROMIS physical (+6.06, P < .01), and EQ-5D overall health (+17.0, P = .012). However, despite these improvements in multiple PROMs, lumbar-related symptoms still persisted at baseline, 3 months, 6 months, 1 year, and 2 years in 20.0%, 14.3%, 13.3%, 33.3%, and 25.0% of patients, respectively. Conclusions:THA was associated with significant and meaningful early hip-specific functional improvements in patients with prior LSF. However, lumbar-related symptoms frequently persisted in many patients. This discordance suggests that hip-specific PROMs may incompletely capture postoperative recovery with hip-spine syndrome. However, these findings should be interpreted as exploratory and hypothesis-generating. Level of Evidence:Level IV, Therapeutic study.
Background This study introduces the obturator externus tendon femoral origin, termed “E-spot,” as a landmark during “off-table” anterior approach total hip arthroplasty (THA). Aims were to determine whether the E-spot could (1) be identified reliably in all cases and (2) help as a reference during femoral preparation to determine the extent of capsular release and femoral implant position. Methods A retrospective analysis of 306 consecutive patients who underwent primary THA by the senior author via an anterior approach between October 2022 and October 2024 was conducted. We attempted to visualize and preserve the obturator externus tendon in all cases and then use it as a reference to determine the extent/completion of capsular release and femoral implant position. Clinical outcomes and complications were assessed at a minimum of 6 months postoperatively to up to 2 years. Results E-spot could (1) be reliably identified as well as (2) the stem to E-spot distance measured in every case (306 out of 306 or 100% reproducibility). There was 1 periprosthetic fracture (Vancouver B2) requiring revision surgery at 2 months postoperatively and 1 dislocation at 3 months postoperatively (0.65% overall early complication rate). No other surgical complications were observed. Conclusions Identifying E-spot in a systematic way is a safe and reliable method of enabling femoral exposure and referencing femoral component position. Based on these results, we now routinely use E-spot to determine the completion of femoral capsular release, assess femoral component position, assure hip stability, and protect the trochanter from injury during off-table anterior THA.
Background:The modular cup-in-cup technique, in which a modular primary acetabular component is cemented into a highly porous monobloc tantalum revision shell, provides the intraoperative flexibility to change bearings if subsequent re-revision is required. This study seeks to characterize the early outcomes of this technique. Methods:A single-center retrospective review was performed of all patients who underwent revision total hip arthroplasty (rTHA) utilizing a modular acetabular component cemented into a highly porous monobloc tantalum revision shell. Preoperative and postoperative radiographs were assessed to quantify bone loss, cup position, and aseptic loosening. All-cause reoperation, revision for aseptic loosening, and revision for instability were estimated using the Kaplan-Meier method. Results:In total, 27 hips were identified with a mean follow-up of 21.6 months. The most common indication for revision was aseptic loosening (48.1%). Preoperatively, 16 (59.3%) hips had Paprosky 3A defects, 7 (25.9%) had Paprosky 3B, 2 (7.4%) had Paprosky 2C defects, and 1 (3.7%) had a Paprosky 2A defect. In total, 4 (14.8%) patients underwent reoperation, 3 (11.1%) for instability and 1 (3.7%) for irrigation and debridement. All patients revised for instability were converted from a dual mobility articulation to a constrained liner. No radiographic loosening was observed at final follow-up. Estimated 3-year survivorships for all-cause reoperation and revision for instability were 84.6% (95% confidence interval: 46.6-95.6%) and 88.5% (95% confidence interval, 48.8-97.6%), respectively. Conclusions:The modular cup-in-cup technique is a viable option for rTHA patients at increased risk of instability. This technique provides surgeons the flexibility to exchange the articulation if recurrent instability occurs.
Background:The relationship between hospital case volume and postoperative morbidity following revision arthroplasty for periprosthetic joint infection (PJI) has not been defined. As such, we sought to compare 90-day postoperative mortality rates among patients undergoing antibiotic spacer placement for PJI of the hip or knee between high- vs low-volume hospitals. Materials and methods:The Premier Healthcare Database was queried from 2016 to 2023 for adult patients undergoing antibiotic spacer placement for PJI. Using the Metropolis-Hastings algorithm, a single hospital volume threshold, below which mortality increased, was identified. Patients were divided by those operated on by high- vs low-volume hospitals. Multivariable logistic regression was conducted to assess odds of 90-day mortality and sepsis. Results:In a cohort of 55,670 PJIs, postoperative mortality was decreased in patients who were operated on by hospitals performing ≥35 antibiotic spacers annually (high volume). The adjusted odds of mortality (adjusted odds ratio = 0.76; 95% confidence interval = 0.65-0.88, P < .001) and sepsis (adjusted odds ratio = 0.69; 95% confidence interval = 0.66-0.73, P < .001) were significantly lower among patients operating at high-volume hospitals. Conclusions:Patients receiving PJI care at hospitals performing greater than 35 antibiotic spacers annually died less frequently and had improved outcomes than those presenting to lower volume centers. These findings reinforce emerging evidence in support of centralized PJI care centers to improve patient survival.
Background The direct anterior approach (DAA) has become the most frequently utilized surgical approach for total hip arthroplasty (THA) in the United States. There is a growing need to clarify the differential risk of complications associated with the DAA compared to other surgical approaches. Heterotopic ossification (HO) is a well-recognized complication following THA that may result in pain and stiffness. Despite its clinical relevance, the risk of HO in DAA patients remains poorly described. In this review, we provide a comprehensive overview of HO following THA, with a particular focus on the DAA. Methods A comprehensive literature search of the PubMed/Medline database was performed using search terms “total hip arthroplasty,” “heterotopic ossification,” and “approach.” Article titles and abstracts were reviewed to determine relevance. Randomized controlled trials, systematic reviews, meta-analyses, comparative studies, and case series were included. Articles not published in the English language were excluded. Results HO results from trauma-induced differentiation of osteoprogenitor cells in soft tissue surrounding the hip joint. Surgical approach is a determinant of HO risk after THA, with the DAA producing the lowest incidence of HO. Other risk factors for the development of HO have been identified, including male gender and advanced age. Prophylaxis against HO includes perioperative nonsteroidal anti-inflammatory drugs, tranexamic acid, and local radiation therapy, while management involves surgical resection of ectopic bone in symptomatic patients. Conclusions This review synthesizes data from recent systematic reviews and case series to provide arthroplasty surgeons with an understanding of postoperative HO risk, stratified by surgical approach.
The medial patellofemoral ligament (MPFL) is vital for patellar stability and tracking within the trochlear groove in early flexion. Although MPFL reconstruction is a well-established treatment for patellar instability in native knees, its role during primary total knee arthroplasty (TKA) remains incompletely defined. This manuscript describes a technique for concurrent MPFL reconstruction during primary TKA in select group of patients with a documented history of chronic patellar instability and persistent intraoperative maltracking despite appropriate component positioning and soft tissue balancing. Key surgical steps include individualized patellar fixation based on bone stock and resurfacing status, isometric femoral tunnel placement, graft tensioning, and selective lateral retinacular lengthening. The described technique provides a reproducible option for addressing persistent patellar instability during primary TKA in highly selected patients with longstanding instability and appropriate implant positioning. Given the risks of arthrofibrosis and the limited available evidence, the procedure should be reserved for very select cases.
Dual mobility (DM) constructs reduce dislocation risk in total hip arthroplasty. The Trident II system accepts a cobalt-chromium liner to create a DM bearing. However, dissimilar metal at the cup-liner interface raises concerns for corrosion. This case series describes six cementless primary Trident II DM total hip arthroplasty patients who experienced gradual onset of hip pain with low-grade inflammatory symptoms and elevated serum cobalt. All patients underwent revision surgery for metallic debris reaction. Preoperative magnetic resonance imaging revealed local tissue reaction, and intraoperative findings confirmed corrosion at the cup-liner interface. Surviellance through serum metal ion testing and magnetic resonance imaging may prevent soft tissue damage and facilitate timely revision. As DM systems evolve, further investigation is warranted to evaluate safety.
Background Distal femoral replacement (DFR) is a standard reconstruction technique following malignant bone tumor resection, yet long-term outcomes and implant-related complications remain insufficiently reviewed. Methods We retrospectively analyzed 88 patients who underwent DFR for malignant or aggressive benign tumors from 1990 to 2023. The cumulative incidences of implant revision, removal, or amputation were estimated using competing risk analysis with death as a competing event. Risk factors for major reoperation were identified through univariate and multivariate analyses. Results Over a median follow-up of 8.0 years, 71 reoperations were performed in 41 patients (30 major and 41 minor). The cumulative incidence of implant removal or revision was 19.8% at 5 years, 36.8% at 10 years, and 52.2% at 20 years. Type 4 complications (infection) were the most common cause of failure, including late-onset infections occurring more than 10 years postoperatively. In multivariate analysis, the presence of a residual epiphyseal plate (hazard ratio: 4.17, P = .012) and use of fixed hinge (hazard ratio: 2.63, P = .042) were significantly associated with increased risk of implant failure. Complex surgical procedures (eg, extra-articular resection or vascular reconstruction) did not significantly increase the risk of implant failure. Conclusions DFR provides durable long-term outcomes, though the risk of revision persists beyond 10 years, primarily due to infection. Residual epiphyseal plate presence is a significant risk factor for implant failure. Complex surgical procedures were not independently associated with implant failure in the adjusted analysis.
Background The medially stabilized (MS) knee concept has gained wider acceptance in recent years. However, to date, there is inconsistent evidence for its merits over traditional total knee arthroplasty (TKA) designs. The aim of this study was to assess the clinical performance of a second-generation medially stabilized knee obtainable by multiple, independent surgeons in a general TKA population. Methods Fifteen surgeons (16 hospitals) participated in this prospective nonrandomized cohort study of 568 patients (608 knees). Demographics represented a standard primary TKA population. Data were collected for baseline characteristics and outcome measures at 6, 12, and 24 months postoperatively for range of motion, the Knee injury and Osteoarthritis Outcome Score, Oxford Knee Score, EuroQol 5-Dimension visual analog scale, University of California Los Angeles activity score, Forgotten Joint Score, patient satisfaction scores, and complications. Results Overall, 548 TKAs were included in the final 2-year follow-up (90.8% follow-up). The revision rate at 2 years was 0.99% (6 knees revised). All measures reported significant improvement from preoperative to 24 months (P < .0001), with good range of motion (119°) and high mean scores, including Oxford Knee Score 42 and Forgotten Joint Score 70. At 2 years, the median satisfaction score was 9.3, 95.7% of patients reported that their problems were better and 94.5% of patients responding that the results of their operation were good, very good, or excellent. Conclusions We found that use of a second-generation MS knee design by multiple surgeons can produce excellent outcomes, with low complication rates and higher levels of patient satisfaction, than those reported in the literature for traditional TKAs. This study represents the largest cohort, multisurgeon, prospective study reported in the literature for the introduction of a new generation MS TKA and supports its wider adoption.
