Three-Dimensional Patient Specific Instrumentation and Cutting Guide for Medial Closing Wedge High Tibial Osteotomy to Correct Valgus Malalignment

Osteotomies of the Knee for Valgus Malalignment

» Osteotomy is an effective treatment strategy for young, active patients with symptomatic valgus malalignment of the knee that has been unresponsive to conservative management.» Osteotomies are also indicated to support joint preservation procedures, such as lateral meniscus allograft transplantation and/or cartilage restoration to the lateral compartment, in the valgus malaligned patient, even if the malalignment is subtle.» Techniques to correct valgus include lateral opening wedge distal femoral osteotomy (LOWDFO), medial closing wedge distal femoral osteotomy (MCWDFO), lateral opening wedge high tibial osteotomy (LOWHTO), or medial closing wedge high tibial osteotomy (MCWHTO). The specific technique chosen depends on surgeon preference, concomitant procedures, and deformity location (femoral, tibial, or both).» Each approach comes with its own advantages and disadvantages. LOWDFO offers easier correction for larger deformities but has a higher risk of nonunion, while MCWDFO facilitates faster time to union but is more technically demanding. For those with a tibial-based deformity, LOWHTO carries a higher risk of nonunion, MCWHTO may lead to medial collateral ligament laxity or patella baja, and both may cause alterations of the tibial slope and may be limited as an isolated procedure in severe deformity correction.» Irrespective of the surgical approach, the outcomes of these procedures are generally favorable, improving patient-reported outcomes and potentially delaying the need for total knee arthroplasty. However, it is crucial to carefully select the appropriate procedure based on the patient's anatomy and the specificities of their valgus deformity to ensure the best possible results.

3D-printed patient-specific instrumentation and the freehand technique in high-tibial osteotomy: A prospective cohort-comparative study in an outpatient setting

Purpose

Tibial valgus osteotomy has shown to be a successful and cost-effective procedure. The advent of image processing and three-dimensional (3D) printing is an interesting tool for achieving more accurate and reproducible results. The aim of our study was to compare the accuracy of the conventional technique and the use of customized guides in the correction of tibial deformities in tibial varus patients, the surgical and clinical benefits, and the impact of treatment in the outpatient setting.

Methods

A prospective cohort of 30 patients who underwent tibial valgus osteotomy were selected and randomized into two groups (3D-printed guidewires and conventional techniques). All patients underwent a complete radiological study to plan the surgical procedure. During the surgical procedure, the surgical time and X-ray exposure were analysed. The following results were evaluated: surgical time and X-ray exposure, the correlation between the planned correction and the correction obtained at 3 post-operative months, pre- and post-operative knee injury and osteoarthritis outcome score (KOOS) value at 3 and 12 months, and differences between the two groups in terms of the correction obtained.

Results

Radiation exposure in the '3D-guide' group was significantly different (8 [±4.51], p < 0.05), whereas surgical time was not significantly different between the control and guide 3D groups (60.69 [±8.89] and 53.43 [±11.69], respectively). At the 3-month follow-up, the post-operative hip-knee-ankle and post-operative mechanical-proximal-tibial angle were not significantly different (p > 0.05). At 3- and 12-month post-surgery, the Knee Injury and Osteoarthritis Outcome Score (KOOS) did not significantly differ between the conventional technique and the 3D-guide technique (p > 0.05). The KOOS at 3 months were 87.86 (±5.64) for the control group and 88.46 (±3.53) for the 3D-guide group, while at 12 months they were 91.5 (±5.72) for the control group and 88.57 (±8.81) for the 3D-guide group.

Conclusion

Customized 3D-printed guides do not permit better correction or functional results than the conventional technique; rather, they reduce surgical time and intraoperative radiation exposure.

Level of Evidence

II.

Progress in Computer-Assisted Navigation for Total Knee Arthroplasty in Treating Knee Osteoarthritis with Extra-Articular Deformity

Total knee arthroplasty (TKA) is a well-established treatment for end-stage knee osteoarthritis. However, in patients with concomitant extra-articular deformities, conventional TKA techniques may lead to unsatisfactory outcomes and higher complication rates. This review summarizes the application of navigated TKA for treating knee osteoarthritis with extra-articular deformities. The principles and potential benefits of computer navigation systems, including improved component alignment, soft tissue balancing, and restoration of mechanical axis, are discussed. Research studies demonstrate that navigated TKA can effectively correct deformities, relieve pain, and improve postoperative joint function and quality of life compared with conventional methods. The advantages of navigated TKA in terms of surgical precision, lower complication rates, and superior functional recovery are highlighted. Despite challenges like the learning curve and costs, navigated TKA is an increasingly indispensable tool for achieving satisfactory outcomes in TKA for knee osteoarthritis patients with extra-articular deformities.

Double-level knee osteotomy accurately corrects lower limb deformity and provides satisfactory functional outcomes in bifocal (femur and tibia) valgus malaligned knees

PURPOSE

Double-level knee osteotomy (DLO) is a challenging procedure that requires precision in preoperative planning and intraoperative execution to achieve the desired correction. It is indicated in cases of severe varus or valgus deformities where a single-level osteotomy would yield significantly tilted joint line obliquity (JLO). This study aimed to evaluate the effectiveness of DLO in achieving accurate correction without compromising JLO, using patient-specific cutting guides (PSCGs), in cases of bifocal valgus maligned knees.

METHODS

A single-centre, retrospective analysis of prospectively collected data for a total of 26 patients, who underwent DLO by PSCGs for valgus malaligned knees, between 2015 and 2020. Post-operative alignment was evaluated and the delta for different lower limb0.05, not statistically significant (ns)). All KOOS subs alignment parameters was calculated; the hip-knee-ankle angle (ΔHKA), medial proximal tibial angle (ΔMPTA), and lateral distal femoral angle (ΔLDFA). At the two-year follow-up, changes in the KOOS sub-scores, UCLA scores, lower limb discrepancy (LLD), and mean time to return to work and sport were recorded. All intraoperative and postoperative complications were recorded. The Mann-Whitney U test with a 95% confidence interval (95% CI) was used to evaluate the differences between two variables; one-way ANOVA between more than two variables and the paired Student's t-test was used to estimate the evolution of functional outcomes.

RESULTS

The postoperative mean ΔHKA was 0.9 ± 0.9°, the mean ΔMPTA was 0.7 ± 0.7°, and the mean ΔLDFA was 0.7 ± 0.8° (all values with p > 0.05, not statistically significant (ns)). All KOOS subscore's mean values were improved to an extent two-fold superior to the reported minimal clinically important difference (MCID) (all with p < 0.0001). There was a significant increase in the UCLA score at the final follow-up (5.4 ± 1.5 preoperatively versus 7.7 ± 1.4, p < 0.01). The mean time to return to sport and work was 4.7 ± 1.1 and 4.3 ± 2.1 months, respectively. There was an improvement in Lower-limb discrepancy preoperative (LLD = 1.3 ± 2 cm) to postoperative measures (LLD = 0.3 ± 0.4 cm), ns. Complications were 2 femoral hinge fractures, 2 deep vein thromboses, 1 delayed tibial healing, and 1 hardware removal for hamstring irritation syndrome.

CONCLUSION

DLO is effective and safe in achieving accurate correction in bifocal valgus malaligned knees with maintained lower limb length and low complication rate with no compromise of JLO.

LEVEL OF EVIDENCE

III.

Custom-Made Devices Represent a Promising Tool to Increase Correction Accuracy of High Tibial Osteotomy: A Systematic Review of the Literature and Presentation of Pilot Cases with a New 3D-Printed System

Background: The accuracy of the coronal alignment corrections using conventional high tibial osteotomy (HTO) falls short, and multiplanar deformities of the tibia require consideration of both the coronal and sagittal planes. Patient-specific instrumentations have been introduced to improve the control of the correction. Clear evidence about customized devices for HTO and their correction accuracy lacks. Methods: The databases PUBMED and EMBASE were systematically screened for human and cadaveric studies about the use of customized devices for high tibial osteotomy and their outcomes concerning correction accuracy. Furthermore, a 3D-printed customized system for valgus HTO with three pilot cases at one-year follow-up was presented. Results: 28 studies were included. The most commonly used custom-made devices for HTO were found to be cutting guides. Reported differences between the achieved and targeted correction of hip-knee-ankle angle and the posterior tibial slope were 3° or under. The three pilot cases that underwent personalized HTO with a new 3D-printed device presented satisfactory alignment and clinical outcomes at one-year follow-up. Conclusion: The available patient-specific devices described in the literature, including the one used in the preliminary cases of the current study, showed promising results in increasing the accuracy of correction in HTO procedure.