Background
Orthopaedic deformity correction is often described as a marriage of science and craftsmanship. While advances in imaging and computer-assisted planning have significantly improved our understanding of complex deformities, translating a meticulously designed plan into precise surgical execution remains one of the greatest challenges in orthopaedic surgery. This challenge was the starting point for our paper, “3D-Printed Patient-Specific Cutting Guides for Multiplanar Long Bone Deformity Correction: Insights from a Narrative Review and Two Case Examples,” recently published in the Indian Journal of Orthopaedics.
The idea
The idea for this review originated from our day-to-day clinical experience. Over the years, we have treated numerous patients with complex long-bone deformities resulting from congenital conditions, trauma, malunions, and previous surgical procedures. In many of these cases, preoperative planning was not the problem. Modern software allows surgeons to calculate deformities with remarkable accuracy. We can determine angular deviations, rotational abnormalities, and changes in mechanical axis to fractions of a degree. Yet, once in the operating room, surgeons often rely on two-dimensional fluoroscopic images, visual estimation, and intraoperative judgment to reproduce a three-dimensional correction.
This disconnect between planning and execution intrigued us.
A particularly memorable patient was a young adult with hereditary skeletal dysplasia who had undergone several surgeries during childhood. He presented with persistent knee pain and a complex distal femoral deformity involving both coronal and rotational malalignment. Conventional planning methods suggested a corrective osteotomy, but the question remained: how could we reliably reproduce the intended correction during surgery? Even a small deviation in osteotomy angle or rotational adjustment could compromise the final outcome.
At around the same time, another patient presented with a severe malunited proximal tibial fracture associated with significant varus deformity and knee instability. The deformity was not merely angular; it involved complex alterations of joint orientation and limb mechanics. These cases highlighted the limitations of conventional techniques and encouraged us to explore emerging technologies that could improve surgical precision.
Patient-specific instrumentation (PSI) offered a compelling solution.
The concept itself is elegant. Using CT-based imaging, a three-dimensional model of the patient's anatomy is created. Surgeons then perform virtual deformity correction using specialized software. Based on this plan, customized cutting guides are manufactured through 3D printing. These guides fit uniquely onto the patient's bone and direct osteotomy cuts and fixation in accordance with the preoperative plan.
Although PSI has been discussed in the literature for several years, its adoption in deformity correction surgery remains variable. We noticed that much of the published work focused on isolated applications or small case series. At the same time, evidence regarding its true advantages and limitations was scattered across different studies. We felt there was a need to synthesize the available knowledge while also sharing practical clinical examples demonstrating how the technology works in real-world settings.
The foundation of our review
The process of preparing the manuscript was itself an educational journey. We reviewed studies evaluating PSI in high tibial osteotomy, distal femoral osteotomy, and complex multiplanar deformity correction. One recurring theme was accuracy. Several studies demonstrated that patient-specific guides could achieve correction parameters with precision exceeding 90%, outperforming conventional techniques in many complex scenarios. We were particularly interested in evidence suggesting improved rotational correction, an area where conventional methods often struggle.
Another striking finding involved radiation exposure. Orthopaedic surgeons routinely depend on fluoroscopy during deformity correction procedures. Recent literature has increasingly highlighted the occupational hazards associated with cumulative radiation exposure. PSI appears capable of significantly reducing fluoroscopy use because many critical surgical decisions are incorporated into the preoperative plan and built directly into the guide design.
The ergonomic benefits were equally noteworthy. Surgeons often spend considerable intraoperative time determining osteotomy orientation, implant position, screw trajectories, and the magnitude of correction. PSI allows many of these decisions to be made before entering the operating theatre. This not only streamlines surgery but may also reduce surgical stress and uncertainty.
However, our review was not intended to be an endorsement of technology for technology’s sake.
During our analysis, we also identified important limitations. Patient-specific guides require high-quality CT imaging, sophisticated software, engineering expertise, and manufacturing resources. They add cost and may require additional surgical exposure for accurate guide placement. Furthermore, in straightforward deformities or in the hands of highly experienced surgeons, the incremental benefit may be relatively modest. We felt it was important to present a balanced perspective rather than portray PSI as a universal solution.
The two clinical cases included in the paper were selected deliberately because they represented situations where precision was particularly important. In both patients, conventional techniques would likely have been more challenging and potentially less reproducible. The ability to visualize the correction virtually, manufacture customized guides, and then execute the plan with confidence provided valuable insights into the practical advantages of PSI.
One of the most rewarding aspects of this project was witnessing how digital technologies are reshaping orthopaedic surgery. When many of us trained, deformity correction depended heavily on manual calculations, paper tracings, and surgeon experience. Today, we are entering an era in which imaging, virtual planning, 3D printing, artificial intelligence, navigation systems, and augmented reality are converging. These technologies do not replace surgical judgment; rather, they augment it.
As we completed the manuscript, we found ourselves thinking less about the current state of PSI and more about its future. Could artificial intelligence automate deformity analysis and surgical planning? Could augmented reality project correction plans directly into the surgeon’s field of view? Could robotic systems execute these plans with even greater precision? While many of these possibilities remain under development, they no longer seem distant.
Ultimately, this paper is about precision—not only in technology but also in patient care. Every deformity is unique, and every patient presents a distinct challenge. The growing ability to personalize surgical planning and execution represents a significant step forward in orthopaedics.
We hope that our review provides clinicians with a practical understanding of where patient-specific instrumentation can be most valuable, while encouraging further research into its clinical effectiveness, accessibility, and integration with future technologies. Most importantly, we hope it stimulates discussion about how digital innovation can help surgeons achieve safer, more predictable, and more personalized outcomes for patients with complex musculoskeletal deformities.
For us, the journey behind this paper reflects a broader transformation occurring across surgery—a transition from approximation toward precision, from standardized solutions toward personalized care, and from conventional planning toward digitally enabled decision-making. It is an exciting time to be involved in orthopaedic innovation, and we are grateful to contribute a small part to that evolving story.