Computer-assisted 3D planned corrective osteotomies in eight malunited radius fractures

Evaluation of a 3D-Printed Reduction Guide for Minimally Invasive Plate Osteosynthesis of Short Oblique Radial Diaphyseal Fracture in Dogs: A Cadaveric Study

This study aims to evaluate the clinical application of three-dimensional (3D)-printed custom reduction guides (3DRG) for minimally invasive plate osteosynthesis (MIPO) of short oblique radial diaphyseal fractures. Canine forelimb specimens (n = 24) were prepared and a diaphyseal short oblique fracture was simulated in the distal radius and ulna. Bone fragments were stabilized with the MIPO technique using a 3DRG (Group A), open reduction (Group B), or closed reduction with circular external skeletal fixation (ESF) (Group C). The diaphyseal short oblique fractures were created in each radius at one-third of the radial length from the distal radial articular surface. Surgical stabilization of the fractures was performed in each group. Pre and postoperative radiographic images were obtained to measure frontal angulation (FA), sagittal angulation (SA), frontal joint reference line angulation (fJRLA), sagittal joint reference line angulation (sJRLA), translational malalignment and fracture gap width. Surgical time was also measured. In the homogeneity test, differences in SA, sJRLA, craniocaudal translation and fracture gap before and after surgery had no significant difference among the three groups. On the other hand, differences in FA, fJRLA, mediolateral translation and surgical time before and after surgery had significant differences among the three groups. In the post hoc test, only surgical time showed a significant difference between the three groups, and group A showed the shortest surgical time. The use of 3DRG for MIPO of short oblique radial diaphyseal fractures in dogs is reliable for the alignment and apposition of fractures and reduces surgical time.

Role of Three-Dimensional Guides in Management of Forearm and Wrist Malunions

Although its precise added value and cost-effectiveness need to be determined, three-dimensional (3D) planning and intraoperative guidance facilitate restoration of normal anatomy. The use of 3D computer planning and patient-specific intraoperative guides leads to more accurate and reproducible correction of forearm and wrist malunion. Its value augments with increasing complexity of deformities. Combined deformities and complex intra-articular malunions of the forearm and wrist benefit the most from the use of 3D techniques. New technical developments, including lower-dose scanning technology, software improvement, artificial intelligence, and in-hospital printing, may lower the associated costs and make its application more accessible.

Current Concepts: Corrective Osteotomy for Extra-Articular Deformity Following a Distal Radius Fracture

Fracture malunion alters wrist and distal radioulnar joint (DRUJ) biomechanics, resulting in incongruence and instability of the DRUJ. Selected patients with painful functional limitation and significant deformity of the radius, but without advanced degenerative joint disease, may benefit from corrective distal radial osteotomy. Non-union and complications arising from metalwork are the most common reasons for reoperation. Surgeons should have a good understanding of risks and complications in order to fully inform their patients and manage expectations. This article reviews the biomechanical effects of radial malunion and the current concepts for treatment. Distal radial osteotomy is suitable for symptomatic patients with angular radial deformity and shortening. Evidence supports a volar approach without bone grafts for modest corrections. Bone grafts or synthetic bone substitutes are appropriate for larger corrections. Functional improvements are reported regardless of technique. Despite a high complication rate, patient satisfaction with the corrective radial osteotomy is high.

Malunion deformity of the forearm: Three-dimensional length variation of interosseous membrane and bone collision

It remains unclear to what extent the interosseous membrane (IOM) is affected through the whole range of motion (ROM) in posttraumatic deformities of the forearm. The purpose of this study is to describe the ligament- and bone-related factors involved in rotational deficit of the forearm. Through three-dimensional (3D) kinematic simulations on one cadaveric forearm, angular deformities of 5° in four directions (flexion, extension, valgus, varus) were produced at two locations of the radius and the ulna (proximal and distal third). The occurrence of bone collision in pronation and the linear length variation of six parts of the IOM through the whole ROM were compared between the 32 types of forearm deformities. Similar patterns could be observed among four groups: 12 types of deformity presented increased bone collision in pronation, 8 presented an improvement of bone collision with an increase of the mean linear lengthening of the IOM in neutral rotation, 6 had an increased linear lengthening of the IOM in supination with nearly unchanged bone collision in pronation and 6 types presented nearly unchanged bone collision in pronation with a shortening of the mean linear length of IOM in supination or neutral rotation. This kinematic analysis provides a better understanding of the ligament- and bone-related factors expected to cause rotational deficit in forearm deformity and may help to refine the surgical indications of patient-specific corrective osteotomy.

The Flipping-Wedge Osteotomy: How 3D Virtual Surgical Planning (VSP) Suggested a Simple and Promising Type of Osteotomy in Pediatric Post-Traumatic Forearm Deformity

(1) Background: The application of computer-aided planning in the surgical treatment of post-traumatic forearm deformities has been increasingly widening the range of techniques over the last two decades. We present the “flipping-wedge osteotomy”, a promising geometrical approach to correct uniapical deformities defined during our experience with virtual surgical planning (VSP); (2) Methods: a case of post-traumatic distal radius deformity (magnitude 43°) treated with a flipping-wedge osteotomy in an 11-year-old girl is reported, presenting the planning rationale, its geometrical demonstration, and the outcome of the procedure; (3) Results: surgery achieved correction of both the angular and rotational deformities with a neutral ulnar variance; (4) Conclusions: flipping-wedge osteotomy may be a viable option to achieve correction in forearm deformities, and it deserves further clinical investigation.

Malunion of Pediatric Forearm Shaft Fractures: Management Principles and Techniques

PURPOSE OF REVIEW

Clinically significant malunion of forearm diaphyseal fractures is an uncommon but potentially disabling condition amongst children and adolescents. We present the preoperative evaluation, including imaging, and discuss surgical indications and contemporary approaches to manage such patients, including an illustrative case.

RECENT FINDINGS

While advances in three-dimensional (3D) simulation, modeling, and patient-specific instrumentation have expanded the surgical armamentarium, their impact on long-term outcomes compared to traditional methods remains unknown. Successful outcome following surgical correction of malunion following a both-bone forearm fracture can be achieved with careful patient selection, appropriate indications, and a well-planned surgical execution.

Outcomes of 3-D corrective osteotomies for paediatric malunited both-bone forearm fractures

Closed treatment of paediatric diaphyseal forearm fractures carries the risk of re-displacement, which can lead to symptomatic malunions. This is because growth will not correct angulation deformity as it does in metaphyseal fractures. The purpose of this prospective cohort study was to evaluate the outcomes after 3-D-planned corrective osteotomy with patient-specific surgical guides for paediatric malunited forearm fractures causing impaired pro-supination. Our primary outcome measure was the gain in pro-supination at 12 months follow-up. Fifteen patients with a mean age at trauma of 9.6 years and time until osteotomy of 5.9 years were included. Preoperatively, patients displayed a mean pro-supination of 67° corresponding to 44% of the contralateral forearm. At final follow-up, this improved to 128°, achieving 85% of the contralateral side. Multivariate linear regression analysis revealed that predictors of greater functional gain after 3-D corrective osteotomy are severe preoperative impairment in pro-supination, shorter interval until 3-D corrective osteotomy and greater angulation of the radius.Level of evidence: III.

Patient-Specific Guided Osteotomy to Correct a Symptomatic Malunion of the Left Forearm

We present a case report of a 12-year old female with a midshaft forearm fracture. Initial conservative treatment with a cast failed, resulting in a malunion. The malunion resulted in functional impairment for which surgery was indicated. A corrective osteotomy was planned using 3D analyses of the preoperative CT-scan. Subsequently, patient-specific guides were printed and used during the procedure to precisely correct the malunion. Three months after surgery, the radiographs showed full consolidation and the patient was pain-free with full range of motion and comparable strength in both forearms. The current case report shows that a corrective osteotomy with patient-specific guides based on preoperative 3D analyses can help surgeons to plan and precisely correct complex malunions resulting in improved functional outcomes.

The malunion of distal radius fracture: Corrective osteotomy through planning with prototyping in 3D printing

INTRODUCTION

Distal radius fractures (DRF) are among the most frequent in the body. About one third of these fractures can result in malunion with restriction of movement and pain in the wrist, the treatment in these cases consists of corrective osteotomy of the deformity. Due to its three-dimensional (3D) complexity, careful preoperative planning is a fundamental step in correction. The prototyping from the 3D reconstruction of the computed tomography of the affected wrist, allows the real understanding of the deformity.

METHODS

Patients with malunion of the distal radius with indication for surgical treatment, from December 2019, were included in the group of corrective osteotomies through planning with prototyping in 3D printing. The postoperative functional outcome was assessed by the Disabilities of the Arm, Shoulder and Hand Score (DASH) and visual analogue scale (VAS). Radiographic data including radial inclination, volar tilt and joint step were recorded from standard posteroanterior and lateral radiographic views.

RESULTS

A total of 9 patients were included. The mean age was 47 years. The average postoperative DASH value of the patients was 24.9 and VAS was 3.6. Radiographically, the palmar tilt had an average improvement of 25.22°, and the radial inclination had an average improvement of 2°.

CONCLUSION

Corrective osteotomy through planning with prototyping in 3D printing is an effective method of treating symptomatic distal radius malunions. The possibility of performing the osteotomy in a 3D model, simulating the surgery, making the procedure more predictable.

An image fusion system for corrective osteotomy of distal radius malunion

Background

To provide surgical support for corrective osteotomy, we developed an image fusion system for three-dimensional (3D) preoperative planning and fluoroscopy. To assess the utility of this image fusion system, we evaluated the reproducibility of preoperative planning for corrective osteotomy of dorsally angulated distal radius malunion using the system and compared reproducibility without using the system.

Methods

Ten wrists from 10 distal radius malunion patients who underwent corrective osteotomy were evaluated. 3D preoperative planning and the image fusion system were used for the image fusion group (n = 5). Only 3D preoperative planning was used for the control group (n = 5). 3D preoperative planning was performed for both groups in order to assess reduction, placement, and the choice of implants. In the image fusion group, the outline of the planned image was displayed on a monitor and overlapped with fluoroscopy images during surgery. Reproducibility was evaluated using preoperative plan and postoperative 3D images. Images were compared with the 3D coordinates of the radial styloid process (1), the volar and dorsal edges of the sigmoid notch (2) (3), and the barycentric coordinates of the three reference points. The reproducibility of the preoperative plan was evaluated by the distance of the coordinates between the plan and postoperative images for the reference points.

Results

The distances between preoperative planning and postoperative reduction in the image fusion group were 2.1 ± 1.1 mm, 1.8 ± 0.7 mm, 1.9 ± 0.9 mm, and 1.4 ± 0.7 mm for reference points (1), (2), (3), and the barycenter, respectively. The distances between preoperative planning and postoperative reduction in the control group were 3.7 ± 1.0 mm, 2.8 ± 2.0 mm, 1.7 ± 0.8 mm, and 1.8 ± 1.2 mm for reference points (1), (2), (3), and the barycenter, respectively. The difference in reference point (1) was significantly smaller in the image fusion group than in the control group (P < 0.05).

Conclusion

Corrective osteotomy using an image fusion system will become a new surgical support method for fracture malunion.

Trial registration Registered as NCT03764501 at ClinicalTrials.gov.

Treatment of Distal Radio Vicious Consolidation: Corrective Osteotomy Through 3D Printing Prototyping

Distal radial fractures are very common. Vicious consolidation can occur in up to one third of these fractures, resulting in wrist pain, restricted movement, and, eventually, physical limitation or disability. The treatment of this condition consists in corrective osteotomy, which requires careful preoperative planning due to its three-dimensional complexity, especially in injuries with joint involvement. Recently, prototyping based on three-dimensional (3D) reconstruction of computed tomography (CT) scans has been used for osteotomy planning in a 3D anatomical model. It allows a better understanding of the deformity in a realistic surgical approach, leading to safer, faster, and more predictable procedures. The aim of the present study is to present this technique and show its use in two clinical cases.

A 3D printed cast for minimally invasive transfer of distal radius osteotomy: a cadaver study

Purpose

In corrective osteotomy of the distal radius, patient-specific 3D printed surgical guides or optical navigation systems are often used to navigate the surgical saw. The purpose of this cadaver study is to present and evaluate a novel cast-based guiding system to transfer the virtually planned corrective osteotomy of the distal radius.

Methods

We developed a cast-based guiding system composed of a cast featuring two drilling slots as well as an external cutting guide that was used to orient the surgical saw for osteotomy in the preoperatively planned position. The device was tested on five cadaver specimens with different body fat percentages. A repositioning experiment was performed to assess the precision of replacing an arm in the cast. Accuracy and precision of drilling and cutting using the proposed cast-based guiding system were evaluated using the same five cadaver arms. CT imaging was used to quantify the positioning errors in 3D.

Results

For normal-weight cadavers, the resulting total translation and rotation repositioning errors were ± 2 mm and ± 2°. Across the five performed surgeries, the median accuracy and Inter Quartile Ranges (IQR) of pre-operatively planned drilling trajectories were 4.3° (IQR = 2.4°) and 3.1 mm (IQR = 4.9 mm). Median rotational and translational errors in transferring the pre-operatively planned osteotomy plane were and 3.9° (IQR = 4.5°) and 2.6 mm (IQR = 4.2 mm), respectively.

Conclusion

For normal weight arm specimens, navigation of corrective osteotomy via a cast-based guide resulted in transfer errors comparable to those using invasive surgical guides. The promising positioning capabilities justify further investigating whether the method could ultimately be used in a clinical setting, which could especially be of interest when used with less invasive osteosynthesis material.

Three-Dimensional Versus Radiographic Measurements for Analyzing Extra-Articular Distal Radius Malunion

PURPOSE

To compare the accuracy of evaluating deformity in distal radius malunions using plain radiographic measurements compared with a 3-dimensional method involving 3-dimensional computer bone models.

METHODS

Consecutive patients who had an extra-articular distal radius malunion were included. Standard radiographs and computed tomography scans of both wrists were performed. Palmar tilt, radial tilt, and ulnar variance were measured on radiographs. The computed tomography scan data were sent to a workstation and 3-dimensional bone surface models of the radius were created. The 3-dimensional palmar tilt, 3-dimensional radial tilt, 3-dimensional ulnar variance, and axial rotational deformity were calculated.

RESULTS

Thirteen patients, mean age 40 years (range, 22-57 years) were included. The 3 3-dimensional values were positively correlated with their corresponding radiographic values. Nevertheless, the 3-dimesional palmar tilt and 3-dimensional radial tilt values were slightly smaller than the radiographic palmar tilt and radial tilt. The quantitative difference between the 3-dimensional method and plain radiographs was on average 2° for the dorsal deformity group and 3° for the palmar deformity group. The 3-dimensional ulnar variance was significantly higher than the radiographic ulnar variance by an average of +1.3 mm for malunions with dorsal tilt and +0.6 mm for malunions with palmar tilt. The 3-dimensional method allowed us to measure the extent of the axial rotational deformity, which was 9° on average (range, 2° to 21°).

CONCLUSIONS

Despite small differences, measurements made on both plain radiographs and 3-dimensional computer bone models are accurate for evaluating the deformity in extra-articular distal radius malunions. Our 3-dimensional method seems to provide a more accurate measurement of ulnar variance, particularly for dorsally angulated cases, and is helpful for measuring rotational malalignment.

CLINICAL RELEVANCE

In this study, we found that either a 3-dimensional computer bone model or plain radiographs can be used as a benchmark to evaluate the deformity of extra-articular distal radius malunion. The 3-dimensional method can also be used to define axial rotational deformity.

Computer-assisted 3D preoperative planning of corrective osteotomy for extra-articular distal radius malunion: A 16-patient case series

The aim of this prospective study was to describe the surgical procedure and to report outcomes of computer-assisted 3D preoperative planning of corrective osteotomy for extra-articular distal radius malunions. Sixteen consecutive patients were enrolled. CT scans of both wrists were performed, and 3D bone surface models of the radii were created. Software was used to simulate the osteotomy and the reorientation of the distal radial articular surface. Patient-specific cutting and drilling guides for intraoperative guidance of the osteotomy as well as bone graft templates were also simulated. At a mean follow-up of 12 months (range 6-27) after surgery, pain was reduced from 3 to 0.3 at rest and 6.8 to 1.5 during effort according to a visual analog scale. The average wrist flexion-extension was 145° and pronation-supination was 155°. Grip strength was 91% of the contralateral side. All patients achieved primary bone union in a mean of 10 weeks (range, 7-18). Using our 3D analysis method, preoperative 3D values showed no significant difference with radiographic measurement. Moreover, there was no significant difference between the postoperative radiographic values in term of correction. This procedure provides satisfactory clinical and radiological results with minimal residual malalignment. LEVEL OF EVIDENCE: III.

Madelung's deformity: capitate-related versus ulna-related measurement methods

Several investigators have defined measurements for Madelung's deformity based on the distal radius or on the longitudinal ulnar axis to avoid the distorted distal radius and its lunate fossa. However, errors may occur in severe cases because of ulnar deformity and displacement. We quantified seven established measurements for Madelung's deformity relying on the central axis of the capitate. The inter- and intrarater reliability of the capitate-related and the ulna-related techniques were compared. We observed a higher inter- and intrarater reliability for the capitate-related method than for the ulna-related method. Better agreement was also observed for measurements of distance than for measurements of angles. However, the palmar tilt angle measurement method was neither reliable nor reproducible. The capitate-related technique can help to accurately determine the severity of Madelung's deformity, assist in surgical planning and identify the prognosis. Level of evidence: III.

Corrective osteotomy in symptomatic clavicular malunion using computer-assisted 3-D planning and patient-specific surgical guides

Surgical correction of a symptomatic clavicular malunion requires simultaneous adjustment of the translation as well as the rotation in multiple planes. We describe a corrective osteotomy for a clavicle malunion using 3-D computer assisted preoperative-planning combined with patient-specific surgical guides, along with the benefits and disadvantages of this approach. This method enabled quantifying the malunion by comparing the malunited bone with the normal contralateral clavicle as a template. The postoperative results were encouraging with symmetrical shoulder anatomy and functional improvement. Therefore, we recommend this technique in patients with a symptomatic clavicle malunion, as it allows successful correction of the deformity.

Accuracy and Early Clinical Outcome of 3-Dimensional Planned and Guided Single-Cut Osteotomies of Malunited Forearm Bones

PURPOSE

To investigate the reduction accuracy of 3-dimensional planned single-cut osteotomies (SCOTs) of the forearm that were performed using patient-specific guides.

METHODS

A retrospective analysis of SCOTs performed between 2012 and 2014 was performed. Ten patients (age, 15-59 years) with 6 malunions of the ulna and 6 malunions of the radius were identified. The reduction accuracy was assessed by comparing the 3-dimensional preoperative plan of each osteotomy with the superimposed bone model extracted from postoperative computed tomography data. The difference was assessed by 3-dimensional angle and in all 6 degrees of freedom (3 translations, 3 rotations) with respect to an anatomical coordinate system. Wrist range of motion and grip strength was assessed after a mean of 16.7 months and compared with the preoperative measurements.

RESULTS

On average, the 12 SCOTs demonstrated excellent accuracy of the reduction with respect to rotation (ie, pronation/supination, 4.9°; flexion/extension, 1.7°; ulnar/radial angulation, 2.0°) and translation (ie, proximal/distal, 0.8 mm; radial/ulnar, 0.8 mm; dorsal/palmar, 0.8 mm). A mean residual 3-dimensional angle of 5.8° (SD, 3.6°) was measured after surgery. All 6 patients operated on for reasons of a reduced range of motion demonstrated improved symptoms and increased movement (from 20° to 80°). In the patients with unstable/painful distal radioulnar joint, 3 were totally free of complaints and 1 patient showed residual pain during sports.

CONCLUSIONS

A SCOT combined with patient-specific guides is an accurate and reliable technique to restore normal anatomy in multiplanar deformities of the forearm.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Prediction of normal bone anatomy for the planning of corrective osteotomies of malunited forearm bones using a three-dimensional statistical shape model

Corrective osteotomies of the forearm based on 3D computer simulation using contralateral anatomy as a reconstruction template is an approved method. Limitations are existing considerable differences between left and right forearms, and that a healthy contralateral anatomy is required. We evaluated if a computer model, not relying on the contralateral anatomy, may replace the current method by predicting the pre-traumatic healthy shape. A statistical shape model (SSM) was generated from a set of 59 CT scans of healthy forearms, encoding the normal anatomical variations. Three different configurations were simulated to predict the pre-traumatic shape with the SSM (cross-validation). In the first two, only the distal or proximal 50% of the radius were considered as pathological. In a third configuration, the entire radius was assumed to be pathological, only the ulna being intact. Corresponding experiments were performed with the ulna. Accuracy of the prediction was assessed by comparing the predicted bone with the healthy model. For the radius, mean rotation accuracy of the prediction between 2.9 ± 2.2° and 4.0 ± 3.1° in pronation/supination, 0.4 ± 0.3° and 0.6 ± 0.5° in flexion/extension, between 0.5 ± 0.3° and 0.5 ± 0.4° in radial-/ulnarduction. Mean translation accuracy along the same axes between 0.8 ± 0.7 and 1.0 ± 0.8 mm, 0.5 ± 0.4 and 0.6 ± 0.4 mm, 0.6 ± 0.4 and 0.6 ± 0.5 mm, respectively. For the ulna, mean rotation accuracy between 2.4 ± 1.9° and 4.7 ± 3.8° in pronation/supination, 0.3 ± 0.3° and 0.8 ± 0.6° in flexion/extension, 0.3 ± 0.2° and 0.7 ± 0.6° in radial-/ulnarduction. Mean translation accuracy between 0.6 ± 0.4 mm and 1.3 ± 0.9 mm, 0.4 ± 0.4 mm and 0.7 ± 0.5 mm, 0.5 ± 0.4 mm and 0.8 ± 0.6 mm, respectively. This technique provided high accuracy, and may replace the current method, if validated in clinical studies. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2630-2636, 2017.

Factors determining outcome of corrective osteotomy for malunited paediatric forearm fractures: a systematic review and meta-analysis

The aim of this study was to identify predictors of a superior functional outcome after corrective osteotomy for paediatric malunited radius and both-bone forearm fractures. We performed a systematic review and meta-analysis of individual participant data, searching databases up to 1 October 2016. Our primary outcome was the gain in pronosupination seen after corrective osteotomy. Individual participant data of 11 cohort studies were included, concerning 71 participants with a median age of 11 years at trauma. Corrective osteotomy was performed after a median of 12 months after trauma, leading to a mean gain of 77° in pronosupination after a median follow-up of 29 months. Analysis of variance and multiple regression analysis revealed that predictors of superior functional outcome after corrective osteotomy are: an interval between trauma and corrective osteotomy of less than 1 year, an angular deformity of greater than 20° and the use of three-dimensional computer-assisted techniques.

LEVEL OF EVIDENCE

II.

Patient specific pointer tool for corrective osteotomy: Quality of symmetry based planning and case study of ulnar reconstruction surgery

Malunion after forearm fractures are described to appear in 2% to 10% of cases. Reconstructive surgeries ensure adequate anatomical repositioning. Their importance derives from the fact that malunion can often lead to severe pain as well as deformities causing loss of function and aesthetic issues not only in the forearm, but also the wrist and elbow joint. In this paper a clinical case will be presented using a Patient Specific Instrument (PSI) as navigational aid for reconstructive surgery after malunion of a proximal ulnar fracture combined with allograft surgery of the radial head and radial condyle due to chronic traumatic radial head luxation (Monteggia fracture). A planning method based on symmetry is described and evaluated on twelve Computed Tomographic (CT) data sets of intact forearms. The absolute point to point deviation at distal end of the ulnar styloid process was used as a characteristic value for accuracy evaluation. It is 7.9±4.9mm when using only the proximal end of the ulna for registration. The simulated change of ulnar variance is -1.4±1.9mm. Design and concept of the PSI are proven in a clinical trial.

Accuracy assessment of surgical planning and three-dimensional-printed patient-specific guides for orthopaedic osteotomies

This study analyses the accuracy of three-dimensional pre-operative planning and patient-specific guides for orthopaedic osteotomies. To this end, patient-specific guides were compared to the classical freehand method in an experimental setup with saw bones in two phases. In the first phase, the effect of guide design and oscillating versus reciprocating saws was analysed. The difference between target and performed cuts was quantified by the average distance deviation and average angular deviations in the sagittal and coronal planes for the different osteotomies. The results indicated that for one model osteotomy, the use of guides resulted in a more accurate cut when compared to the freehand technique. Reciprocating saws and slot guides improved accuracy in all planes, while oscillating saws and open guides lead to larger deviations from the planned cut. In the second phase, the accuracy of transfer of the planning to the surgical field with slot guides and a reciprocating saw was assessed and compared to the classical planning and freehand cutting method. The pre-operative plan was transferred with high accuracy. Three-dimensional-printed patient-specific guides improve the accuracy of osteotomies and bony resections in an experimental setup compared to conventional freehand methods. The improved accuracy is related to (1) a detailed and qualitative pre-operative plan and (2) an accurate transfer of the planning to the operation room with patient-specific guides by an accurate guidance of the surgical tools to perform the desired cuts.

Three-dimensional virtual planning of corrective osteotomies of distal radius malunions: a systematic review and meta-analysis

The purpose of this study was to summarize and evaluate results of three-dimensional (3D-) planned corrective osteotomies of malunited distal radius fractures. 3D-planning techniques provide the possibility to address 3D-deformity that conventional planning methods might not address. We systematically searched PubMed, EMBASE and the Cochrane library for studies that performed a 3D-planned corrective osteotomy on patients with a malunited distal radius fracture. Fifteen studies with a total of 68 patients were included in the analysis. In 96% of cases, the preoperatively present palmar tilt, radial inclination and ulnar variance showed statistically significant improvement postoperatively with restoration to within 5° or 2 mm of their normal values. Mean flexion–extension, pro-supination and grip strength showed statistically significant improvement (p < 0.05). Complications were reported in 11 out of 68 patients (16%). With the current advances in 3D printing technology, 3D-planned corrective osteotomies seem a promising technique in the treatment of complex distal radius malunions.

Level of evidence IV Systematic review of case series, Level IV.