To investigate the association of preoperative serum secreted phosphoprotein 1 (SPON1) and apolipoprotein E (APOE) with chronic postsurgical pain (CPSP) following total knee arthroplasty (TKA), providing a hypothetical basis for validation studies. This retrospective study included 218 patients who underwent unilateral TKA between March 2023 and February 2025 with 6-month follow-up. CPSP was defined as a knee pain score > 3 on the visual analog scale (VAS) during movement at 6 months postoperatively. Demographic and clinical data, preoperative and postoperative pain scores, painDETECT questionnaire (PD-Q), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Hospital Anxiety and Depression Scale (HADS) scores, and preoperative serum SPON1 and APOE levels were collected. ROC curve was performed to evaluate the performance of serum SPON1 and APOE in discriminating CPSP-positive from CPSP-negative patients after TKA. Multivariable logistic regression analysis was performed to explore risk factors for CPSP following TKA. Fifty-five patients were CPSP-positive and 163 were CPSP-negative. The CPSP-positive group had fewer years of education, higher prevalence of diabetes mellitus, longer duration of preoperative pain and knee osteoarthritis (KOA), and higher preoperative VAS, PD-Q, WOMAC, and HADS scores (all p < 0.05). Serum SPON1 and APOE levels were significantly higher in the CPSP-positive group (both p < 0.05), and positively correlated ( r = 0.253, p < 0.05). The combination of SPON1 and APOE had an area under the curve (AUC) of 0.908 (95% CI: 0.864-0.951), indicating good discriminative ability between CPSP-positive and CPSP-negative patients, superior to SPON1 alone ( Z = - 3.144, p = 0.002) and APOE alone ( Z = - 3.078, p = 0.002). Multivariable analysis showed more years of education was a protective factor, whereas higher preoperative PD-Q and WOMAC scores and elevated serum SPON1 and APOE levels were risk factors for CPSP. Serum SPON1 and APOE levels were associated with CPSP after TKA, and their combination showed favorable discriminative ability. Because the model was not validated, these results represent preliminary evidence of an association; the clinical value of these markers as potential biomarkers requires confirmation in prospective studies.
Tibial plateau fractures (TPFs) are complex intra-articular injuries frequently accompanied by significant soft tissue injury. Existing medical literature has shown that TPFs resulting from a flexion-varus injury mechanism, affecting the posteromedial column primarily, are associated with worse clinical outcome scores and a higher risk of conversion to total knee arthroplasty. This narrative review aims to explain why this specific subgroup has a poorer prognosis compared with other TPFs subtypes. Four key factors are examined in this review: fracture morphology, biomechanics, soft tissue involvement, and surgical management. The complex fracture morphology of flexion-varus TPFs can be most accurately assessed using three-dimensional computed tomography-based reconstructions. The mechanism of injury helps to better understand fracture morphology and potential soft tissue injury. Soft tissue injuries are frequent in these type of fractures, such as anterior cruciate ligament (ACL) avulsion fracture, lateral meniscus tears, and entrapment. These three elements are important for better understanding TPFs and adequately planning surgical strategy. The severity of the fracture and the involvement of the posterolateral depression complicate surgical treatment. Visualization of the posteromedial compartment is essential but remains challenging. Anatomical reduction and stable fixation of the posteromedial and posterolaterocentral tibial plateau, with consideration of any meniscal injury, should be performed with care. An ACL avulsion fracture should ideally be fixed. Although preoperative magnetic resonance imaging (MRI) provides valuable information about the soft tissue involved, this examination is not yet routinely performed. Given the high incidence of ACL and (lateral) meniscal injury, an MRI is highly recommended.
The prevalence of knee osteoarthritis and the annual incidence of total knee arthroplasty (TKA) continue to rise. A substantial proportion of TKA candidates have diabetes mellitus, which is associated with increased perioperative risk. Prior studies have largely focused on preoperative hemoglobin A1c (HbA1c), while the effect of postoperative glycemic control on complication rates remains less well-defined. This study evaluated the relationship between late postoperative HbA1c levels and postoperative complications following TKA. A propensity score-matched retrospective cohort study was performed using the TriNetX multi-institutional database. Adults aged 18 to 90 years who underwent primary TKA with documented HbA1c > 8% for 3 months preoperatively, who were able to decrease it to under 7.5% for < 3 months preoperatively. HbA1c values obtained 1 to 2 years postoperatively were used to define cohorts: Cohort 1 (HbA1c < 7.5%) and Cohort 2 (HbA1c >= 8.0%). Outcomes included early medical complications (30 and 90 days) and arthroplasty-specific complications within 5 years, including periprosthetic joint infection, revision surgery, mechanical loosening, and periprosthetic fracture. After matching, a total of 3,200 patients met the inclusion criteria, with 1,600 patients in each cohort after matching. There were no significant differences in 30-or 90-day medical complications between groups. At 5 years, rates of periprosthetic joint infection, revision surgery, mechanical loosening, and periprosthetic fracture were also similar. Elevated postoperative HbA1c at 1 to 2 years following TKA was not independently associated with increased risk of complications or implant failure when perioperative glycemic control was optimized. These findings suggest that once early healing occurs under adequate glycemic conditions, later deterioration in glycemic control may have a limited impact on arthroplasty outcomes.
Conventional intraoperative gap assessment is performed in standardized reference positions that do not replicate many functional postures patients assume during daily activities. Physiologic lateral compartment opening becomes most apparent in postures combining flexion, hip external rotation, and relative varus alignment, such as sitting cross-legged, and shoe or sock application. The figure-of-4 position reproduces this combination intraoperatively. The purpose of this study was to describe the figure-of-4 maneuver as an intraoperative positional assessment during robotic total knee arthroplasty (rTKA) and quantitatively characterize compartment behavior during its execution using standardized robotic measurements. Eightythree consecutive primary rTKAs performed by a single surgeon were retrospectively analyzed. After bone preparation and balancing, with trial components in situ, each knee underwent conventional and figure-of-4 assessment. The VELYS standardized robotic measurement framework was used for both conditions; only limb posture differed. Compartment behavior was expressed as the medial-to-lateral gap difference (Delta ML; medial minus lateral) in flexion and extension. Conventional and figure-of-4 Delta ML were compared within each knee using paired t-tests and Wilcoxon signed-rank tests. Preoperative hip-knee-ankle (HKA) angle was correlated with the change in Delta ML using Pearson and Spearman coefficients. Figure-of-4 assessment produced consistently more negative flexion Delta ML than conventional assessment (mean difference-2.181 mm; 95% CI:-2.414 to-1.947; p < 0.001; Cohen's d= 2.039). Extension Delta ML did not differ significantly (mean difference 0.080 mm; 95% CI:- 0.019 to 0.178; p= 0.113). Preoperative HKA angle did not correlate with the change in flexion Delta ML (r= 0.091, p= 0.416) or extension Delta ML (r=-0.111, p= 0.318). Figure-of-4 assessment consistently demonstrated greater lateral compartment opening in flexion than conventional assessment, while extension measurements remained essentially unchanged. The standardized robotic measurement framework enabled objective quantification of compartment behavior in a positional condition not evaluated during routine assessment. The maneuver characterizes behavior of the prepared knee in a posture associated with common activities of daily living and provides information complementary to conventional assessment.
Clinical studies suggest a role for the keel of the tibial component in preventing aseptic loosening in total knee arthroplasty (TKA). To analyze the role of a central stem within the keel, we compared two designs of tibial components for the Triathlon TKA (Stryker): standard keel components that have a central stem and fins (Triathlon universal tibial baseplate) and finned components that have fins alone and lack a central stem (Triathlon primary tibial baseplate). Questions: (1) is there a difference in all-cause revision rate or revision rates for loosening? (2) Is there a difference in revision rates when stratified by sex, body mass index (BMI) or insert conformity? We used retrospective data from the Australian Orthopaedic Association National Joint Replacement Registry of 76,710 minimally stabilized cemented TKAs performed without stem extensions for primary osteoarthritis from September 1999 to December 2023. The mean age of patients was 69.3 +/- 8.9 years, and 59.6% were females. The mean follow-up was 5.6 years. Cumulative percent revision from Kaplan-Meier estimates was used to compare the revision rates between finned and standard keel tibial components. Hazard ratios (HR), adjusted for sex and age, were used for comparison. There was no difference in the overall revision rate between standard and finned tibial components (HR: 1.05, 95% confidence interval [CI]: 0.74-1.48, p = 0.779) or in revision rates for loosening with the numbers available for the study. Stratification by sex, BMI, and insert conformity (cruciate-retaining and condylar-stabilizing) did not show a difference between the groups. Females had a marginally higher risk of revision than males when finned components were used (HR: 1.33, 95% CI: 1.01-1.75, p = 0.045). Central stems within the keel of cemented tibial components do not alter the survivorship of minimally stabilized TKA.
