Background: Total knee arthroplasty (TKA) has evolved significantly, yet achieving consistently optimal outcomes remains challenging across diverse patient populations. This comprehensive narrative review identifies evidence-based “game changers” that genuinely transform TKA success while distinguishing them from interventions lacking clinical superiority. The analysis organizes findings across three perioperative phases: preoperative optimization, intraoperative techniques, and postoperative management. Preoperative game changers include end-stage bone-on-bone osteoarthritis, preoperative medical optimization of patients performed by dedicated practitioners, cryocompression therapy, and perioperative dexamethasone administration. Intraoperative interventions demonstrating substantial impact encompass reduced surgical time and optimized surgical instrumentation, personalized alignment, medial congruent bearings, cementless implants for high-demanding and high-BMI patients, and perioperative tranexamic acid. Postoperative game changers include early mobilization following surgery, venous thrombo-embolic prophylaxis avoiding high-bleeding-risk pharmaceuticals, and multimodal pain management. The review also identifies those initial promises without established clinical advantages, or “fake game changers”, that consume resources without meaningful benefits. This evidence synthesis demonstrates that TKA optimization requires systematic implementation of validated interventions rather than pursuing technological innovations indiscriminately. The future of TKA lies in evidence-based adoption of proven strategies that translate to genuine patient outcome improvements rather than merely increasing procedural complexity.

Background/Objectives: The ROSA^® Partial Knee System (Zimmer Biomet, Warsaw, IN, USA) is an imageless robotic platform developed to improve the reproducibility of tibial resection and implant positioning in unicompartmental knee arthroplasty (UKA). Evidence on imageless ROSA-assisted medial UKA remains limited. This preliminary single-center study evaluated the early radiographic accuracy of the system in reproducing planned tibial coronal alignment and tibial slope during robotic-assisted medial UKA, while perioperative and short-term clinical findings were assessed as secondary exploratory observations. Methods: A retrospective analysis of a prospectively maintained database was performed on 23 consecutive patients who underwent robotic-assisted medial UKA using the ROSA^® Partial Knee System and Persona^® Partial Knee implant between December 2025 and March 2026. Planned and robot-validated values were compared with postoperative radiographic measurements, which were used as the achieved alignment reference. Deviations >2° and >3° from target were defined as outliers. Paired clinical analyses were restricted to patients with data available at both time points. Results: Mean age was 68.4 ± 8.5 years and mean BMI was 28.2 ± 4.1 kg/m². Preoperative HKA was 5.4 ± 3.4° varus, while final robot-validated and postoperative radiographic HKA values were 2.3 ± 0.7° and 2.6 ± 0.9° varus, respectively (p = 0.08). Robot-validated and postoperative radiographic MPTA values were 2.0 ± 0.5° and 2.1 ± 0.7°, respectively (p = 0.41). Planned, robot-validated, and postoperative radiographic tibial slope values were 4.5 ± 0.6°, 4.6 ± 0.6°, and 4.8 ± 0.8°, respectively (p = 0.27). Mean absolute postoperative deviation from target was 0.42 ± 0.38° for HKA, 0.34 ± 0.29° for MPTA, and 0.46 ± 0.39° for tibial slope. Within 2° of target, accuracy ranged from 91.3% to 95.7%, and all cases were within 3°. Short-term clinical outcomes improved in the available paired subsets (n = 14 for VAS and KSS, n = 12 for ROM, and n = 9 for UCLA activity score). Conclusions: In this preliminary single-center observational series, the ROSA^® Partial Knee System showed high early radiographic accuracy in reproducing planned tibial coronal alignment and tibial slope during robotic-assisted medial UKA, with low outlier rates. Short-term clinical findings were favorable in the available paired subsets but should be interpreted as exploratory. Larger comparative studies with longer follow-up are needed to determine the clinical relevance of this technical accuracy.

Purpose: To evaluate the platform-specific learning curve and early tibial radiographic agreement of imageless ROSA ^® -assisted medial unicompartmental knee arthroplasty (UKA), with short-term clinical findings assessed exploratorily. Methods: This retrospective consecutive case series included 30 patients who underwent ROSA ^® -assisted medial UKA with the Persona ^® Partial Knee implant between January and April 2026 at a high-volume arthroplasty referral centre. A continuous learning-curve cumulative summation (LC-CUSUM) analysis of total surgical duration was performed against an independently defined surgeon-specific historical benchmark derived from institutional operative-register skin-to-skin times for manual UKA performed by the same surgeon (20 ± 4 min). Adequate performance was defined as a mean duration of 25 min, inadequate performance as 30 min, and the reference standard deviation as 4 min. Type I and type II error targets were 0.05 and 0.10, respectively; the decision boundary was calibrated by Monte Carlo simulation over a 30-case monitoring horizon. Robotic time and a supportive comparison of cases 1–5 versus 6–30 were secondary efficiency analyses. Postoperative radiographic measurements were performed by an observer blinded to the planned and robot-validated ROSA ^® values. Agreement was quantified using Bland–Altman bias and 95% limits of agreement. Results: Mean robotic time was 14.5 ± 2.4 min, mean non-robotic time was 8.9 ± 3.1 min (range, 4.1–15.6), and mean total surgical duration was 23.4 ± 2.3 min. The continuous LC-CUSUM score crossed the calibrated decision boundary (h = 4.5895) at case 6. Robotic time was 16.0 ± 3.8 min in cases 1–5 and 14.2 ± 2.0 min in cases 6–30 ( p = 0.787); corresponding total durations were 24.8 ± 3.8 and 23.1 ± 1.9 min ( p = 0.385). Bland–Altman bias for postoperative minus planned measurements was + 0.13° for tibial coronal alignment and + 0.10° for tibial slope; bias for postoperative minus robot-validated HKA was + 0.34°. All 30 postoperative radiographic measurements were within ± 2° of the planned target for both tibial coronal alignment and slope (100%; exact 95% CI, 88.43%–100%). Conclusions: The predefined platform-specific temporal-performance standard was reached after six cases by an experienced high-volume UKA surgeon. Tibial planned-to-postoperative deviations were small in this consecutive series, while the findings remain conditional on the specified benchmark and require external validation.

Background and Objective: Dislocation remains one of the leading causes of failure after total hip arthroplasty (THA). Growing evidence shows that abnormalities in spinopelvic mobility significantly alter functional acetabular orientation during daily activities, predisposing to instability. This narrative review aims to summarize the relationship between spinopelvic mobility and dislocation risk after THA, describe the underlying biomechanical mechanisms, and highlight diagnostic tools and preventive strategies. Methods: This narrative review was conducted according to the SANRA (Scale for the Assessment of Narrative Review Articles) methodological guidelines. A structured literature search was performed in PubMed/MEDLINE, Embase, Web of Science, and the Cochrane Library from inception to June 2024 using keywords related to spinopelvic mobility, sagittal alignment, functional acetabular orientation, and THA instability. Of 152 records identified, 30 studies met predefined inclusion criteria and were included. Key functional parameters extracted included sacral slope change (ΔSS), pelvic tilt, pelvic incidence-lumbar lordosis (PI-LL) mismatch, functional anteversion, and the Combined Sagittal Index (CSI). Key Content and Findings: Three clinically relevant spinopelvic patterns were consistently reported: Spinopelvic stiffness (ΔSS 30°): exaggerated sagittal pelvic motion, causing instability at extremes of flexion or extension depending on cup position. Dynamic parameters (ΔSS, PI-LL mismatch, APPt, CSI) demonstrated greater predictive value than static acetabular angles. Standing and sitting lateral radiographs provided sufficient functional assessment in most clinical settings. Individualized cup positioning based on mobility pattern and selective use of dual-mobility implants were the most consistently reported preventive measures. Conclusions: Spinopelvic mobility is a critical determinant of postoperative stability after THA. Functional assessment with standing and sitting lateral radiographs allows identification of mobility patterns and supports individualized acetabular positioning. Dual-mobility constructs and precision technologies may reduce the risk of instability in high-risk patients. Prospective studies with standardized imaging protocols and validated functional indices are needed to refine functional safe zones.

Purpose: To evaluate early patient‐reported outcome measures (PROMs), radiographic alignment changes, intraoperative laxity changes and complications in a retrospective series of constitutional valgus knees treated with robotic‐assisted total knee arthroplasty (TKA) using an intentional asymmetric balancing strategy and a semi‐personalized (SP) alignment technique. Methods: This retrospective single‐centre cohort included consecutive patients with end‐stage valgus osteoarthritis (OA) and constitutional valgus morphotypes (coronal plane alignment of the knee III/VI) treated with imageless robotic‐assisted TKA and a minimum follow‐up of 12 months. The balancing workflow intentionally accepted mild residual lateral laxity. Medial and lateral compartment laxity (mm) were quantified intraoperatively at 0° and 90°. PROMs (Knee Society Score [KSS] and Forgotten Joint Score [FJS]), range of motion (ROM) and hip–knee–ankle angle (HKA) were assessed preoperatively and at the latest follow‐up. Complications were recorded. Results: Fifty‐eight patients were included at a mean follow‐up of 26.5 ± 15.0 months. KSS Knee improved from 58.3 ± 9.4 to 87.9 ± 11.0 (mean change +29.6 points, 95% confidence interval [CI] = 26.0–33.2; p = 0.00002) and KSS Function from 58.8 ± 15.0 to 82.4 ± 15.7 (mean change +23.6 points, 95% CI = 18.8–28.4; p = 0.00004). Flexion contracture improved from 3.9 ± 4.0° to 0.6 ± 1.2° (mean change −3.3°, 95% CI = −4.3 to −2.3; p = 0.00010), while flexion increased from 101.4 ± 6.0° to 126.8 ± 8.6° (mean change +25.4°, 95% CI = 23.2–27.6; p = 0.00001). HKA improved from 6.2 ± 4.5° valgus to 2.1 ± 1.8° valgus (mean change −4.1°, 95% CI = −5.2 to −3.0; p = 0.00030). Lateral laxity decreased in extension from 4.5 ± 1.7 to 2.5 ± 1.3 mm (mean change −2.0 mm, 95% CI = −2.7 to −1.3; p = 0.001) and at 90° from 5.3 ± 2.0 to 1.9 ± 1.2 mm (mean change −3.4 mm, 95% CI = −4.3 to −2.5; p = 0.0008), with smaller medial reductions. Post‐operative complications occurred in four patients (6.9%) (deep vein thrombosis, transient peroneal neuropraxia, superficial wound issue and one manipulation under anaesthesia); there were no pulmonary emboli, periprosthetic joint infection or revision procedures. Conclusion: In this retrospective single‐surgeon series of constitutional valgus knees treated with robotic‐assisted TKA, intentional asymmetric balancing was associated with good early clinical outcomes, correction towards less valgus alignment, and a reproducible reduction in lateral laxity, with a low complication rate. These findings support the feasibility of this measurable laxity‐guided strategy, but do not establish superiority over alternative balancing philosophies. Level of Evidence: Level III, retrospective cohort.