The applications of 3D printing technology in health care, particularly orthopedics, continue to broaden as the technology becomes more advanced, accessible, and affordable worldwide. 3D printed models of computed tomography (CT) and magnetic resonance image (MRI) scans can reproduce a replica of anatomical parts that enable surgeons to get a detailed understanding of the underlying anatomy that he/she experiences intraoperatively. The 3D printed anatomic models are particularly useful for preoperative planning, simulation of complex orthopedic procedures, development of patient‐specific instruments, and implants that can be used intraoperatively. This paper reviews the role of 3D printing technology in orthopedic surgery, specifically focusing on the role it plays in assisting surgeons to have a better preoperative evaluation and surgical planning.

Lateral patellar dislocation (LPD) is a musculoskeletal condition characterized by a complex etiology. Despite significant advancements in management strategies, it continues to pose considerable challenges. Critical anatomic risk factors previously identified include trochlear dysplasia (TD), patella alta, and elevated tibial tubercle–trochlear groove (TT‐TG) distance, with TD being the most significant. A thorough risk assessment using predictive models is primarily recommended to assist in patient counseling and to identify high‐risk cases, for whom early surgical intervention may be considered. Controversies persist regarding the indications for combined surgical procedures, including tibial tubercle osteotomy (TTO), derotational distal femoral osteotomy (DDFO), and lateral retinacular release (LRR) with medial patellofemoral reconstruction (MPFLR). Moreover, emerging evidence suggests that a deeper understanding of the interplay between anatomic factors may optimize surgical prioritization and improve clinical outcomes. The combined surgical approach should be reserved for meticulously selected cases with substantial anatomic risk factors, while isolated MPFLR may prove adequate for cases with milder grade risk factors. To enhance individualized treatment strategies and improve outcomes for patients with LPD, deeper insights into the interaction of anatomical factors, supported by higher‐quality clinical research and advancements in biomechanical modeling, are essential.

Objective: This study analyzed the effects of medial patellofemoral ligament (MPFL) injury and varying degrees of lateral retinacular release (LRR) on patellofemoral joint (PFJ) contact pressure using finite element analysis (FEA).Methods: A PFJ FE model was developed and validated at four knee flexion angles (0°, 30°, 60°, and 90°) using imaging data from a patient with A-B trochlear dysplasia and critical abnormalities of patella alta and tubercle-trochlear groove (TT-TG) value. MPFL injury was simulated by inhibiting its function, while LRR was modeled by adjusting the stiffness of the lateral retinaculum. Changes in PFJ contact pressure were systematically analyzed.Results: At 0° flexion, LRR led to increased PFJ pressure with an intact MPFL, whereas it resulted in a reduction with a ruptured MPFL. At 30° flexion, partial LRR didn’t elevate PFJ pressure when MPFL was intact, while complete LRR did with both intact and ruptured MPFL. At 60° flexion, partial LRR effectively reduced PFJ pressure, but complete release reversed this effect. At 90° flexion, PFJ pressure increased with the extent of LRR, irrespective of MPFL integrity. Specifically, complete LRR led to an increase in medial pressure, resulting in a shift of the pressure center from lateral to medial at 30° and 60° flexion.Clinical Implications: This study provides new theoretical basis for the expected outcomes of varying degrees of LRR, which helps clinicians better conduct preoperative planning, especially in avoiding over - aggressive LRR procedures which may not yield improved outcomes.Conclusion: In patients with A- B trochlear dysplasia and critical abnormalities, excessive LRR does not consistently lower PFJ pressure but rather increases medial compartment pressure, suggesting that partial release may be a more effective and precise surgical approach in these patients.

Objective: 3D joint space width (JSW) mapping quantifies structural narrowing in knee osteoarthritis (OA), but the effect of surface mesh resolution on measurement reliability and precision remains unclear. This study assessed how mesh resolution influences 3D JSW measurements, whether effects differ by metric and OA severity, and which resolutions best preserve OA group‐level discrimination and subject‐level agreement. Methods: Knees with medial knee OA (KL grades 0–4) were analyzed. For each knee, 3D JSW maps were generated on a 0.1 mm reference mesh and seven coarser meshes (0.3, 0.5, 0.7, 1.0, 2.0, 3.0, and 4.0 mm). Minimum and median JSW (minJSW, medJSW) were calculated within a standardized medial region and compared to the reference. Systematic error, agreement (Bland–Altman), and subject‐level interchangeability were evaluated across resolutions for the overall cohort and early versus advanced OA subgroups. Absolute‐error thresholds were set at 0.2 mm (sensitivity) and 0.5 mm (clinical significance). Mesh‐by‐severity interactions were analyzed using mixed‐effects models, and group‐level discrimination was assessed at each resolution. Results: Seventy‐two knees from 54 patients (mean age 65 ± 10.4 years; 48.6% advanced OA) were included. The 0.1 mm reference mesh had excellent geometric fidelity (RMS deviation 0.0011 ± 0.0010 mm) and high vertex density (median 118,300 vertices), which dropped to 14,848 at 0.3 mm, 5033 at 0.5 mm, and 72 at 4.0 mm. From 0.1 to 4.0 mm, medJSW increased from 4.07 ± 0.77 mm to 5.14 ± 0.96 mm and minJSW from 1.98 ± 0.81 to 2.34 ± 0.81 mm, converging at 0.3 mm. Subject‐level agreement for medJSW declined beyond 0.3 mm: at 0.5 mm and coarser meshes, ≥ 44.4% of knees exceeded the 0.2 mm error threshold; at 0.7 mm and coarser meshes, ≥ 12.5% exceeded the 0.5 mm threshold. In contrast, minJSW remained within the 0.5 mm clinical threshold through 1.0 mm. Early OA showed a larger absolute medJSW inflation ( p = 0.023), whereas advanced OA had greater relative minJSW error ( p < 0.05). Group‐level OA discrimination remained preserved at all resolutions ( p < 0.001), while subject‐level agreement deteriorated at coarser meshes. Conclusions: Mesh resolution significantly influences 3D JSW measurements, with effects modulated by selected metric, disease stage, and level of analysis. Using a rigorous 0.1‐mm reference mesh, specific thresholds were established: a 0.3‐mm mesh provided the most consistent performance across all conditions; a 0.5‐mm mesh may be acceptable for medJSW under a less stringent error tolerance; and up to 1.0 mm sufficed only for identifying the narrowest point (minJSW). At coarser resolutions, baseline JSW overestimation can be large enough to alter perceived structural severity of medial compartment narrowing, carrying risks for clinical misinterpretation and treatment decisions.