High tibial osteotomy with virtual planning and patient specific instrumentation: a narrative review

High tibial osteotomy (HTO), particularly through a medial opening-wedge technique [medial opening-wedge high tibial osteotomy (MOWHTO)], is a well-established surgical intervention for correcting varus malalignment and unloading the medial compartment in younger patients with early osteoarthritis or secondary ligamentous or chondral deficiency. However, conventional methods pose high technical demands for accurate alignment, often requiring repeat intraoperative fluoroscopy. Patient-specific instrumentation (PSI), developed through three-dimensional (3D) imaging and printing technologies, offers a promising solution by enabling precise preoperative planning and intraoperative execution via customized cutting guides. This narrative review aims to explore the inception and current data surrounding PSI in HTO, specifically in regards to radiation, cost effectiveness, hinge fractures, surgical accuracy, and multiplanar osteotomies.

A comprehensive literature review was conducted using PubMed, incorporating studies related to "high tibial osteotomy", "virtual planning", "patient-specific instrumentation", and "3D planning" published up to March 1st, 2025. Relevant English-language studies were included to summarize the use and outcomes associated with PSI in HTO.

The literature consistently demonstrates that PSI significantly enhances the precision and reproducibility of HTO. PSI is associated with a marked reduction in intraoperative fluoroscopy use and operative time, supporting its role in improving surgical efficiency and radiation safety. The costs of PSI vs. traditional osteotomy are nearly identical, with potential for even further monetary savings in revision rates, survivorship, and downstream healthcare utilization. Current evidence on hinge fracture prevention remains inconclusive, but PSI offers theoretical benefits through controlled cutting depths, hinge-pin technology, and anatomically tailored guides. Studies report alignment deviations typically within 2° of the preoperative plan in both coronal and sagittal planes, surpassing traditional and navigation-assisted techniques.

PSI represents a significant advancement in the execution of high tibial osteotomies, offering increased surgical accuracy, reduced radiation exposure, and enhanced procedural efficiency. It holds particular value in complex or multiplanar deformities where traditional techniques are limited. Although cost and hinge fracture data remain areas for further investigation, the growing body of evidence supports PSI's clinical utility and reproducibility. As 3D planning technologies and guided manufacturing become more accessible, PSI is well-positioned to become a standard adjunct in knee realignment procedures.