Journal of Knee Surgery最新文献

Previous studies reported greater knee extensor muscle weakness in female patients compared with males after anterior cruciate ligament (ACL) reconstruction. However, the mechanisms underlying this sex difference remain unclear. We investigated whether there are sex differences in muscle atrophy after ACL reconstruction. Rats were divided into four groups: Male control, male ACL reconstruction, female control, and female ACL reconstruction. To quantify the amount of weight-bearing, gait analysis was performed during the experimental period. Muscle atrophy was assessed by measuring muscle fiber cross-sectional area (CSA) at 7, 28, and 84 days after starting the experiment. In the rectus femoris, a similar extent of atrophy was observed at 7 days after ACL reconstruction, but atrophy recovered by 28 days in both males and females. However, at 84 days, rectus femoris atrophy occurred again in females only. In the semitendinosus and gastrocnemius, significant atrophy was detected at 7 days after ACL reconstruction in males, but not in females. Both males and females showed a reduction in weight-bearing early after ACL reconstruction, with a more pronounced reduction in males. Early semitendinosus and gastrocnemius atrophy was more severe in males, and this may be explained by differences in weight-bearing. Delayed rectus femoris atrophy, observed exclusively in females, may explain the weakened knee extensor strength observed in female patients.

Tranexamic acid (TXA) and epsilon-aminocaproic acid (EACA) are antifibrinolytic agents commonly used to reduce blood loss in total knee arthroplasty (TKA). Although TXA is widely adopted, EACA offers a potentially more economical alternative. However, head-to-head comparisons using paired designs remain limited. The present randomized controlled trial included 294 patients undergoing bilateral TKA. Each patient received topical TXA in one knee and topical EACA in the contralateral knee in a randomized sequence. Primary outcomes included total perioperative blood loss and total drain output over 3 days. Secondary outcomes included transfusion requirement, postoperative complications, and cost-effectiveness. The statistical analyses included paired t-tests, linear mixed-effects models for effect modification, logistic regression for transfusion and complications, and cost-effectiveness analysis comparing drug costs against blood loss reduction. Data from 294 patients (588 knees) were analyzed. TXA was associated with a statistically significant but modest reduction in total blood loss compared with EACA (mean difference: 10.03 mL, p < 0.001), well below the predefined non-inferiority margin of 200 mL. Similarly, drain output was also found to be lower in TXA-treated knees (mean difference: 10.07 mL; p  =  0.0001), but the difference was not considered clinically significant. The rates of transfusion and postoperative complications were low (2.72 and 3.74% respectively). Cost-effectiveness analysis revealed EACA to be more cost effective as compared with TXA. Topical EACA was found to be non-inferior to TXA in reducing perioperative blood loss in TKA, with equivalent clinical outcomes and greater cost-effectiveness. These findings support the use of EACA as a cost-saving alternative to TXA, particularly in resource-limited settings.

Arthrofibrosis is a debilitating complication following total knee arthroplasty (TKA), affecting 3 to 13% of primary TKA patients and leading to 10% of revision surgeries. This review evaluates the current management strategies for arthrofibrosis, answering key questions on treatment modalities: (1) nonsurgical interventions, (2) arthroscopic and open surgical approaches, (3) revision procedures, and (4) adjunct and emerging therapies. Nonsurgical treatments, including aggressive physical therapy and continuous passive motion devices, show some improvements in range of motion (ROM), but long-term efficacy remains uncertain. Arthroscopic lysis of adhesions improves knee flexion by 26.7 to 51.2 degrees, with a mean final flexion of 100 to 103 degrees, but carries higher infection and revision risks. Open arthrolysis provides ROM improvements up to 43.4 degrees, with higher morbidity and complications. Revision TKA yields better functional outcomes, with mean flexion improvements of 15 to 25 degrees, but 43% of patients require further care. Emerging therapies, such as low-dose irradiation and pharmacologic agents like celecoxib and dexamethasone, show promise but require further validation. Despite advancements, gaps in high-quality data and standardized protocols persist, underscoring the need for more prospective trials.

The Centers for Medicare and Medicaid Services (CMS) recently mandated the collection of Patient-Reported Outcome-Based Performance Measures (PRO-PMs) for Medicare patients undergoing inpatient total knee arthroplasty (TKA). The policy's generalizability remains a concern. Therefore, we aimed to compare PROMs capture rates, patients' characteristics, and achieving the substantial clinical benefit (SCB) threshold between inpatient and outpatient Medicare TKA. A prospective cohort of Medicare patients aged ≥ 65 who underwent primary TKA between 2016 and 2022 at a single health system was analyzed (n = 7,926). Patients were categorized as inpatient (length of stay [LOS] > 24 hours, n = 2,812) or outpatient (LOS ≤ 24 hours, n = 5,114). Capture rates of CMS-mandated variables, baseline characteristics, and 1-year outcomes were compared. SCB was defined as a 20-point improvement in the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) per CMS criteria. Baseline capture rates were similar between groups (approximately 82.8%), but 1-year KOOS-JR completion was lower for inpatients (53.3% vs. 62.4%). Inpatients had higher comorbidity burden (CCI ≥ 2: 40% vs. 33%, p < 0.001), worse KOOS-JR (median 44.9 vs. 47.5, p < 0.001), lower VR-12 MCS scores (50.2 vs. 54.1, p < 0.001), and more frequent nonoperative joint pain (75.1% vs. 68.6%, p < 0.001) and back pain (67.4% vs. 63.8%, p < 0.001). Outpatients trended toward better SCB achievement (OR: 0.89, 95% CI: 0.78-1.00, p = 0.054). Compared to outpatients, inpatient Medicare TKA patients had lower 1-year PROM capture rates, more comorbidities, and worse baseline PROMs, with a trend toward not meeting CMS SCB thresholds. These differences highlight limitations in using inpatient-only data to assess national TKA outcomes, especially as outpatient procedures grow. Nonetheless, future studies with higher power should validate these findings. The level of evidence is III (retrospective).

Alignment strategy in total knee arthroplasty (TKA) remains a subject of debate. Although mechanical alignment (MA) has long been the standard, kinematic alignment (KA) has gained interest for its patient-specific approach aiming to restore native knee kinematics. Comparative evidence from randomized controlled trials (RCTs) on clinical effectiveness and safety remains variable. A systematic search of PubMed, Scopus, Cochrane Library, and Google Scholar through June 2025 identified 21 RCTs comparing KA and MA in primary TKA. Outcomes assessed included functional scores (Knee Society Score [KSS], Oxford Knee Score [OKS], KOOS, WOMAC), quality of life (EQ-5D, Forgotten Joint Score [FJS]), pain (VAS at rest and mobilization), range of motion, satisfaction, and complications rates. KA was associated with modestly better outcomes in early postoperative function and patient satisfaction. Statistically significant advantages were found for knee flexion (MD = 2.49 degrees; p = 0.002), KSS function (MD = 6.39; p < 0.00001), KSS objective score (MD = 2.24; p < 0.00001), KSS satisfaction (MD = 3.11; p = 0.001), FJS (MD = 3.79; p < 0.0001), WOMAC (MD = -6.44; p = 0.01), and VAS pain at rest (MD = -0.39; p < 0.0001). No significant differences were observed in extension, pain during mobilization, length of stay, or complication rates. Kinematic alignment yields clinical outcomes at least equivalent to mechanical alignment, with small but statistically significant improvements in early function, joint awareness, and patient satisfaction, without increased risk of complications or revision. Although the clinical relevance of these differences is modest, KA represents a safe and effective alternative that may enhance patient-perceived recovery. Long-term data remain essential to determine whether KA offers durable advantages in survivorship and late functional outcomes.

The rate of recurrent instability following primary medial patellofemoral ligament (MPFL) reconstruction has been reported to be as high as 6.7%. However, limited studies have reported on clinical outcomes and complications following revision MPFL reconstruction. Furthermore, the role of previously identified risk factors for primary failure (e.g., patella alta and trochlear dysplasia) warrants further study in this patient population. Therefore, the goal of this study was 2-fold. First, to evaluate the prevalence of anatomic risk factors and technical errors among patients presenting for revision patellofemoral surgery. Second, to report early clinical outcomes following revision MPFL reconstruction. A single-surgeon registry was queried for patients who underwent revision MPFL reconstruction (including prior MPFL imbrication, MPFL reconstruction, tibial tubercle osteotomy [TTO]) from November 2015 to June 2022. Preoperative imaging was evaluated for risk factors including (1) misplacement of the femoral tunnel, (2) Caton-Deschamps index, (3) tibial tubercle-trochlear groove distance (TT-TG), (4) patellar tilt, and (5) trochlear dysplasia. Patient-reported outcomes and complications were obtained at final follow-up (minimum 1 year). The study included 32 patients (72% female, age: 23.9 ± 6.6 years). Mean time from index surgery to revision MPFL reconstruction was 4.8 ± 4.7 years (range 0.6 to 17.9 years). The most prevalent anatomic risk factors were patella alta (72%), TT-TG >15 mm (53%), trochlear dysplasia (Dejour type B, C, or D) (50%), and excessive patellar tilt (41%). The median number of risk factors was 3 (range 0-6), and 17 patients (53%) had three or more risk factors. At final follow-up (24.1 ± 14.5 months), no patients experienced recurrent patellofemoral instability or graft failure. Postoperative IKDC (p < 0.001) and SF-12 PCS (p < 0.001) scores improved significantly compared with preoperatively. In conclusion, the majority of patients presenting for revision MPFL reconstruction had three or more risk factors for recurrent dislocation.IV, Case Series.

The purpose of this study was to (1) compare the accuracy and precision of a surgeon's manual soft-tissue balancing compared to the modified pendulum knee drop (PKD) tests and (2) evaluate the generalizability of the modified PKD test across a range of polyethylene thicknesses and surgical plans. Methods Robotic-assisted TKAs were performed on an advanced knee simulator (AKS) model. In the first arm of this study, four high-volume arthroplasty surgeons conducted manual laxity assessments on the AKS, repeated with a knee stocking using the modified PKD test with inserts from nine to 14 millimeters (mm). A total of 15 blinded trials were performed per surgeon. Cohen's kappa statistics were calculated for the manual and modified PKD groups. For the second arm, two independent surgeons developed two surgical plans for the same deformity and the PKD test was used to evaluate tibial inserts ranging from nine to 14 mm to quantify laxity changes. A total of three trials were conducted per tibial insert for each surgical plan, totaling 48 trials. Analyses of variance tests were used to assess the significance between surgical plans based on stiffness values and knee excursion with Tukey post hoc analyses to locate differences. Results Surgeons were able to identify the correct polyethylene thickness 65% of the time and the modified PKD test 96.7% of the time (P < 0.001). The average intra-rater kappa was 0.58 when surgeon-only and 0.95 when the surgeon used the PKD test. There was no improvement in accuracy across the three rounds for each surgeon. Across both surgical plans, smaller inserts exhibited increased laxity, while larger inserts demonstrated increased stiffness. Across both surgical plans, there was a progressive increase in stiffness with larger inserts. Discussion High-volume arthroplasty surgeons have variability in their soft-tissue balancing, which is improved with the use of the PKD test, and 2) the use of a modified PKD test can reproducibly give quantitative data on TKA stiffness across surgical plans.

Periprosthetic patella fractures are a rare complication that can lead to severe disability following total knee arthroplasty (TKA). There are several factors that increase the risk of this injury, including patient comorbidities, anatomic considerations, and surgical technique. With these factors limiting healing ability in the area, periprosthetic patellar fractures can pose a major challenge to treat, with potentially lasting morbidity for affected patients. These fractures can occur at any time following TKA and are classified based on their associated implant stability and disruption of the extensor mechanism using the Ortiguera and Berry classification system. Each of the three types of fractures can be managed in their own unique way; however, outcomes remain poor, and the complication rates remain high regardless of fracture type. This article provides an overview of the current literature and the recommended management of periprosthetic patella fractures.

Osteochondral allograft transplantation (OCAT) is safe and effective for the treatment of large articular defects in the knee. Yet, there are no quantitative methods for predicting OCAT outcomes. This study was designed to analyze serum and urine biomarkers collected prior to OCAT to determine their capabilities for predicting outcomes with respect to functional graft survival. Prospectively collected data for patients undergoing primary multisurface knee OCAT, enrolled in an outcomes registry, were analyzed for graft survival. Blood and urine samples were collected prior to surgery for biomarker analyses. Biomarker concentrations were analyzed for the capability to predict OCAT failures (revision or arthroplasty) that occurred within the first 2 years. Fifty consecutive patients were included for analysis; the 2-year graft survival (success) rate was 80%. In samples obtained prior to OCAT, concentrations of serum hyaluronan (HA) and urine cross-linked C-telopeptide of type II collagen (CTX-II) were significantly higher for failure patients. A urinary biomarker panel containing cross-linked C-telopeptide of type I collagen (CTX-I), CTX-II, HA, IL-8, MMP-2, MMP-3, MMP-13, osteoprotegrin (OPG), and osteopontin (OPN) was able to predict the likelihood of treatment failure with an area under the curve (AUC) of 0.895, sensitivity of 85.3%, and specificity of 93.8%. Preoperative concentrations of urine CTX-II and urine MMP-3 were significantly associated with a higher risk for OCAT treatment failure. Serum and urine protein biomarkers analyzed prior to surgery have the potential to predict functional graft survival at 2 years following complex multisurface OCAT surgery in the knee. With further validation, these biomarkers may be useful as a component of the shared decision-making process for patients and health care teams to evaluate this treatment option. Level of Evidence 2, prospective cohort study.

The impact of preoperative patellofemoral malalignment (PFM) on the prognosis of patients who underwent total knee arthroplasty (TKA) remains unknown. This study aimed to explore the effect of preoperative PFM on the prognosis of patients who underwent TKA. This retrospective observational study included patients who underwent TKA at the Second Hospital Affiliated to Fujian Medical University between February 2018 and July 2020. The primary outcome measure was the Hospital for Special Surgery Knee-Rating Scale (HSS) score. The secondary outcomes included postoperative radiographic parameters (X-rays) and the occurrence of complications. A total of 94 patients (107 knees) who underwent TKA were included in the study. Of these, 37 knees had PFM and 70 had normal patellofemoral alignment (PFA). Patients with preoperative PFM showed a change in patellar outward displacement from 7.01 ± 3.91 mm preoperatively to -0.31 ± 2.86 mm postoperatively (p < 0.001), and the lateral patellar tilt angle changed from 9.45 ± 7.47 degrees to 6.06 ± 3.61 degrees (P = 0.009). Postoperative radiographic parameters between the PFM and PFA groups did not show any significant difference (p > 0.05), but the postoperative HSS score in the PFM group was lower than in the PFA group (total score: 70.35 ± 8.39 vs. 80.47 ± 5.44, p < 0.001). In addition, 13 (35.14%) knees in the PFM group experienced postoperative anterior knee pain compared to 10 (14.29%) knees in the PFA group (P = 0.013). Preoperative PFM may have an impact on the HSS score and the occurrence of anterior knee pain in patients after TKA. These findings suggest that surgeons should carefully evaluate preoperative PFA in patients undergoing TKA. Furthermore, patients with PFM may require additional monitoring and management of postoperative anterior knee pain, as well as special considerations for optimizing functional outcomes.