Journal of Knee Surgery最新文献

Modern highly porous surfaces have increased confidence and use of cementless total knee arthroplasty (TKA) in the United States. As cementless TKA use increases, there remains a paucity of literature regarding associated risk of revision in patients aged ≥65 years. We analyzed the American Joint Replacement Registry (AJRR) data from January 2012 to March 2020 identifying patients aged ≥65 years undergoing primary TKA with linked cases to supplemental centers for Medicare and Medicaid data. Patients with hybrid fixation, reverse hybrid fixation, missing component data, highly constrained implants, and stem extension/augmentation were excluded. We identified 442,745 cemented TKAs and 19,841 modern cementless TKAs with a minimum of 2-year follow-up. Cumulative incident function (CIF) curves and cause-specific Cox models evaluated the risk of all-cause revision and revision for mechanical loosening, adjusting for body mass index (BMI), sex, age, cruciate retaining (CR) versus posterior stabilized (PS) femoral design, patellar resurfacing, and Charlson's comorbidity index (CCI). Patients with cementless compared with cemented TKA were younger (mean age: 71.9 vs. 73.2 years, p < 0.001), more likely to be male sex (48.8 vs. 39.0%, p < 0.001), more likely to have a CR femoral design (81.1 vs. 45.7%, p < 0.001), less likely to have patellar resurfacing (92.7 vs. 95.0%, p < 0.001), and had a lower CCI (mean: 2.9 vs. 3.1, p < 0.001). Adjusted hazard ratios (HRs) showed no difference in associated risk for all-cause revision (HR: 1.07; 95% confidence interval [CI]: 0.92-1.24; p = 0.382) or revision for mechanical loosening (HR: 1.38; 95% CI: 0.9-2.12; p = 0.14) for cementless versus cemented TKA. Our results suggest that current selective use of cementless fixation for TKA in patients aged ≥65 years in the United States is not associated with an increased risk of revision. While encouraging, further study is necessary to establish indications for use in this age group prior to broader adoption in this patient population. LEVEL OF EVIDENCE:  Therapeutic Level III.

Mechanical loosening is a leading cause of failure of total knee arthroplasties (TKAs) for which obesity may be a risk factor. With rising rates of obesity and increasing incidence of TKA, the identification of factors to mitigate this cause of failure is necessary. The purpose of this study is to determine if the use of a tibial stem extender (TSE) decreases the risk of mechanical loosening in patients with obesity undergoing TKA. The American Joint Replacement Registry and linked Centers for Medicare & Medicaid Services claims database were utilized to identify a patient cohort with a body mass index (BMI) of 30 kg/m² or greater and age 65 years or older who underwent primary elective TKA between 2012 and 2021. Patients were divided into cohorts based on obesity class and TSE utilization. The estimated association of TSE use, BMI categories, and covariates with the risk of revisions for mechanical loosening in both unadjusted and adjusted settings was determined. Hazard ratios and their 95% confidence intervals for the risk of mechanical loosening were calculated. A total of 258,775 TKA cases were identified. A total of 538 of 257,194 (0.21%) patients who did not receive a TSE and one patient out of 1,581 (0.06%) with a TSE were revised for mechanical loosening. In adjusted analysis, TSE use was not protective against mechanical loosening and BMI > 40 was not a significant risk factor. Use of a TSE was not found to be protective against mechanical loosening in patients with obesity; however, analysis was limited by the small number of outcome events in the cohort. Further analysis with a larger cohort of patients with TSE and a longer follow-up time is necessary to corroborate this finding.

The benefit of patellar resurfacing in total knee arthroplasty (TKA) remains uncertain, with conflicting evidence regarding associated revision rates and clinical outcomes. Although initial studies have reported higher revision rates associated with unresurfaced patellae, recent evidence questions the necessity of routine patellar resurfacing. This study aimed to evaluate the risk of revision following TKA performed with and without patellar resurfacing using data from the American Joint Replacement Registry (AJRR).The AJRR was queried for all patients aged 65 years and older undergoing elective TKA between January 2012 and March 2020 with a minimum 2-year follow-up. Cases were linked using supplemental Centers for Medicare and Medicaid data. Cases with hybrid fixation, highly constrained implants, and revision components were excluded. Patients were categorized into two groups: those with a resurfaced patella and those without. Cumulative incidence function (CIF) curves and cause-specific Cox models were utilized to assess all-cause revision risk, adjusting for sex, age, femoral design (cruciate retaining vs. posterior stabilized), fixation type (cemented vs. cementless), and Charlson Comorbidity Index.Of the 390,304 TKAs with minimum 2-year follow-up in our cohort, 22,829 had no patellar resurfacing performed. Adjusted hazard ratios (HRs) revealed no significant difference in all-cause revision (HR = 0.96, 95% confidence interval [CI]: 0.81-1.13, p = 0.656), revision for mechanical loosening (HR = 1.61 [0.88, 2.93], p = 0.122), or revision for infection (HR = 1.02 [0.79, 1.33], p = 0.860) associated with patellar resurfacing status.Our study found that patients with an unresurfaced patella do not face an increased short-term revision risk following TKA. These findings challenge the necessity of routine patellar resurfacing and underscore the importance of considering other factors, such as femoral design, patient comorbidities, and implant-related variables in revision risk stratification.

The current literature lacks data regarding perioperative complications after medial patellofemoral ligament reconstruction (MPFLr). The objective of this study was to identify the incidence and predictors of adverse events in the first 90 days after MPFLr. Patients undergoing primary MPFLr between January 1, 2010, and December 31, 2019, were included. Predictors of readmission for any reason were identified using a multivariable logistic regression analysis. A total of 140 MPFLrs were included in the final analysis. Of these, 17 patients (12.1%) were admitted in the first 90 days after MPFLr. The most common reason for readmission was pain (7/140, 5%), followed by cellulitis (5/140, 3.5%). The only major complication was pulmonary embolism experienced by one patient (1/140, 0.7%). Univariate logistic regression analysis demonstrated that patients who ever smoked were 4.5 times (p = 0.005) more likely to be readmitted in the first 90 days. Although additional soft-tissue procedures increased the readmission rated by 21% (p = 0.810) and additional chondral procedure increased by 35% (p = 0.568), the multivariable analysis did not reveal a significant difference. Surgeons can use this information to counsel patients on what to expect following MPFLr.

This study compared the outcomes of tibial tubercle osteotomy (TTO) and trochleoplasty for the treatment of patellar instability associated with trochlear dysplasia. This was a systematic review of the literature including published articles that describe either trochleoplasty or TTO in addition to medial patellofemoral ligament reconstruction for the surgical treatment of patellar instability associated with trochleoplasty. Main outcomes assessed were Kujala and International Knee Documentation Committee (IKDC) scores, in addition to recurrent instability and complications. Outcome measures reported were provided in a table format and a subjective analysis was performed. Ten studies were included with a total of 362 knees including 132 in the trochleoplasty group and 230 in the TTO group. Mean follow-up ranged from 27.6 to 61.3 months. At the final follow-up, both Kujala and IKDC scores improved significantly in all studies that reported both preoperative and postoperative scores in both groups. There was a total of three instability events in the trochleoplasty group as opposed to 21 in the TTO group. Both procedures, trochleoplasty and TTO, may provide satisfactory functional improvement in patients with patellar instability associated with trochlear dysplasia. However, trochleoplasty may be a better option to minimize the risk of recurrent instability. Level of evidence: level IV, systematic review of level III and level IV studies.

Traditional research on total knee arthroplasty (TKA) relies on preoperative patient-reported outcome measures (PROMs) to predict postoperative satisfaction. We aim to identify distinct patient phenotypes among TKA candidates, and investigate their correlations with patient characteristics. Between 2017 and 2021, patients with primary knee cases at a metropolitan public hospital were enrolled in a clinical quality registry. Demographics, clinical data, and the Veterans Rand 12 and Oxford Knee Score were collected. Imputed data were utilized for the primary analysis, employing k-means clustering to identify four phenotypes. Analysis of variance assessed differences in scores between clusters, and nominal logistic regression determined relationships between phenotypes and patient age, sex, body mass index (BMI), and laterality. The sample comprised 389 patients with 450 primary knees. Phenotype 4 (mild symptoms with good mental health) exhibited superior physical function and overall health. In contrast, patients in phenotype 2 (severe symptoms with poor mental health) experienced the most knee pain and health issues. Phenotype 1 (moderate symptoms with good mental health) reported high mental health scores despite knee pain and physical impairment. Patient characteristics significantly correlated with phenotypes; those in the severe symptoms with poor mental health phenotype were more likely to be younger, female, have a higher BMI, and bilateral osteoarthritis (p < 0.05). This multidimensional analysis identified TKA patient phenotypes based on common PROMs, revealing associations with patient demographics. This approach has the potential to inform prognostic models, enhancing clinical decision-making and patient outcomes in joint replacement.

Historically, cementless patellar implants were fraught with issues of fixation and polyethylene wear. However, contemporary cementless patellar implants incorporate modern technologies for implant design and offer the potential for improved biological fixation and longevity. As such, an evaluation of the performance of modern cementless patellae is needed. The purpose of this study was to perform a systematic review and meta-analysis of contemporary cementless patellar implants used during primary total knee arthroplasty (TKA), with a particular focus on aseptic loosening of the patellar component.A systematic review of the literature was performed from January 2000 to February 22, 2024. We included all peer-reviewed studies that reported the number of revisions in patients who had cementless patellae placed in 2000 or later during primary TKA. Reviews and case reports were excluded. Out of 639 studies, 13 were included with a total of 3,005 cementless patellae analyzed. The mean patient age was 64 years and the mean body mass index (BMI) was 31 kg/m². Meta-analyses were performed to calculate the pooled revision rate per person-year of revision for aseptic loosening of the patellar component and revision for any patellar failure.Upon analysis of 13 studies involving a total of 3,005 cementless patellae, the revision rate for aseptic loosening of the patella was 0.2 per 1,000 person-years and the revision rate for any patellar failure was 1 per 1,000 person-years.Contemporary cementless patellar implants showed an overall revision rate of 1 per 1,000 person-years, demonstrating excellent longevity. The high survivorship, together with a low rate of loosening, show the utility and effectiveness of these implants. Given the nature of biologic fixation, these results are promising for long-term implant stability but additional follow-up is warranted.

Stiffness after total knee arthroplasty (TKA) can lead to decreased function and patient dissatisfaction. Manipulation under anesthesia (MUA) is often performed to improve range of motion (ROM); however, there is no consensus on indications or timing. The purpose of this study was to compare clinical results and patient-reported outcome measures (PROMs) between patients who underwent MUA versus those with an uncomplicated postoperative course following primary TKA. This was an institutional review board-approved retrospective review of 116 consecutive patients who underwent MUA from 2013 to 2019 following primary TKA due to stiffness. Indication for MUA was failure to achieve 105 degrees of knee flexion at 6 weeks following surgery. Five patients underwent revision surgery and 15 patients from the MUA group were excluded: 12 lost to follow-up and 3 deaths. The remaining 96 MUA patients were matched to 288 TKAs who did not require MUA or revision, all with a minimum 2-year follow-up. Patients who underwent MUA were younger (60.7 vs. 66.3 years, p < 0.001) and had less preoperative knee flexion (105.4 vs. 110.7 degrees, p < 0.001). There were five (4.9%) revisions in the MUA group: two instability, two chronic pain, and one arthrofibrosis. There were no differences between the groups with respect to postoperative Knee Society Knee Score, Western Ontario and McMaster Universities Osteoarthritis, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Forgotten Joint Score-12, satisfaction, or complications. Satisfaction rates were 88.5% among MUA patients and 89.6% among non-MUA patients (p = 1.0). Patients undergoing MUA following TKA, using the criteria of failure to achieve 105 degrees of flexion by 6 weeks postoperatively, were able to achieve similar PROMs and satisfaction compared with a control group with a low incidence of revision due to persistent arthrofibrosis.

Patellar tendon rupture (PTR) is a rare and severe postoperative complication of total knee arthroplasty (TKA). Even rarer is the intraoperative occurrence of PTR during TKA. PTR is a major complication as it can lead to chronic disability, functional limitations, and postoperative morbidity. Therefore, surgical repair of the intraoperative PTR is typically pursued through one of the following three methods: (i) primary repair with direct suturing; (ii) direct suturing with cerclage augmentation, and (iii) direct suturing with either autograft or synthetic graft augmentation. In the case of an incomplete tear, direct repair with suture anchors for distal tears, and end-to-end repair with/without synthetic graft augmentation for mid-substance and proximal tears, is recommended. In the case of complete tears, if adequate tissue is present, direct repair with extensor mechanism reconstruction should be performed, regardless of the location of the tear. Furthermore, for complete tears with defective tissue, extensor mechanism reconstruction should be performed using mesh or allograft augmentation, regardless of the location of the tear. This review aims to provide a comprehensive and thorough overview of the prevention, diagnosis, management, and outcomes of intraoperative extensor mechanism injuries during TKA.