Computer-assisted distal radius osteotomy

Management of Extra-Articular and Intra-Articular Distal Radius Malunion

This article presents a comprehensive overview of managing extra-articular and intra-articular distal radius malunions (DRM), discussing the pathoanatomy, clinical, and radiologic evaluation, conservative treatment, and surgical strategies. Corrective osteotomy remains the primary surgical intervention for symptomatic DRM. Surgical planning should consider factors such as timing, approach, correction technique, implant, graft, and associated injuries. The correction of extra-articular malunion necessitates brachioradialis tenotomy, circumferential periosteum release, and intrafocal elevation with grafting to facilitate distal radius realignment following osteotomy. Computer-assisted planning with 3D-printed patient-specific instrumentation (PSI) could help execute extra-articular osteotomy with high precision. As for the management of intra-articular malunion, it may require wrist arthrotomy, arthroscopy, or PSI assistance for precise articular osteotomy and reduction of the joint surface. This review highlights the importance of early intervention, thorough preoperative planning, and appropriate surgical techniques to optimize outcomes and minimize complications. Future research should focus on large-scale randomized controlled trials to compare different surgical methods, particularly for intra-articular DRM.

Corrective osteotomy of the distal radius with palmar locking plate osteosynthesis without bone grafting and without cortical contact

The aim of this study was to assess bone healing and secondary fracture displacement after corrective osteotomy of the distal radius without any cortical contact using palmar locking plates without bone grafting. Between 2009 and 2021, 11 palmar corrective osteotomies of extra-articular malunited distal radius fractures and palmar plate fixations without the use of bone grafts and without cortical contact, were assessed. All patients showed complete osseous restoration and significant improvement in all radiographic parameters. Except for one patient, there were no secondary dislocations or loss of reduction in the postoperative follow-up. Bone grafts may not be mandatory for bone healing and prevention of secondary fracture displacement after palmar corrective osteotomy without cortical contact and fixation with palmar locking plate.Level of evidence: IV.

Three cases of posttraumatic wrist problems solved with 3D-printed patient-specific guides

Symptomatic malunion of the wrist is one of the most common posttraumatic wrist problems. This study demonstrates three patients with complex malunions of the wrist who benefited from a corrective osteotomy using preplanned 3D-printed patient-specific guides, by experiencing improvement in their wrist function, grip strength and a reduction in pain.

Locked Wire Fixator for a Distal Radius Fracture With Malunion: A Case Report

Surgical treatment for a distal radius fracture using a volar locking plate is difficult if the distal radius malunion remains. Therefore, a different surgical method from volar locking plate fixation should be required. We report the case of an 83-year-old woman with a left dorsal displaced distal radius fracture. However, the deformity of the volar cortex of the radius was recognized because of a previous distal radius fracture. Therefore, osteosynthesis with a locked wire fixator was performed. At 12 months after surgery, the patient has returned to daily activities without difficulty. A locked wire fixator can be useful for treating a distal radius fracture with malunion of the volar cortex of the distal radius.

3D planning and patient specific instrumentation for intraarticular corrective osteotomy of trapeziometacarpal-, metacarpal and finger joints

Background

Intra-articular malunions of the finger can lead to deformity and loss of function and can be treated with intra-articular corrective osteotomies. The aim of this study was to evaluate radiographic joint congruency, feasibility and functional outcome of three-dimensional (3D) printed patient-specific instrumentation (PSI) for corrective osteotomies at the trapeziometacarpal and finger joints.

Methods

Computer-tomography (CT) scans were acquired preoperatively for standard 3D planning, which was followed by calculation of cutting planes and the design of individualized bone surface contact drilling, sawing and reposition guides. Follow-up CT scans and clinical examinations (range of motion, grip strength) were performed. Postoperative complications were documented and patient-reported outcome measurements were assessed (Single Assessment Numeric Evaluation (SANE) score, brief Michigan Hand Questionnaire (MHQ)).

Results

Ten patients (mean age 28.4 ± 12.8,range 13.8–51.3) years) were included with a mean follow-up of 21 ± 18 (3–59) months including seven osteotomies at the trapeziometacarpal or metacarpophalangeal joints and three at the proximal interphalangeal joint (PIP). All radiographic follow-up examinations showed the planned correction with good joint congruency and regular osseous consolidation. At the latest follow-up, the range of motion (ROM) increased and the average grip strength recovered to the level of the contralateral side. No postoperative complication was detected. The mean SANE score improved from 44 ± 23 (0–70) to 82 ± 12 (60–90) after a mean of 72 ± 20 (44–114) months. The mean postoperative brief MHQ was 92 ± 8 (71–98).

Conclusion

The use of 3D PSI in treating intra-articular malunions at the trapeziometacarpal and finger joints restored articular congruency accurately. ROM and grip strength improved postoperatively comparable to the healthy contralateral side and patient-reported outcome measures improved after medium-term follow-up.

Intermediate-Term Outcome of 3-Dimensional Corrective Osteotomy for Malunited Distal Radius Fractures With a Mean Follow-Up of 6 Years

PURPOSE

Our study aimed to analyze the functional and radiological intermediate-term outcome of 3-dimensional-guided corrective osteotomies for malunited distal radius fractures and to evaluate the progression of osteoarthritis after this intervention.

METHODS

All patients with malunited distal radius fractures who underwent 3-dimensional-guided corrective osteotomies from October 2008 to January 2015 were included. Pre- and postoperative range of motion, grip strength, and postoperative patient-reported outcomes were assessed. Pre- and postoperative osteoarthritis grading was performed using conventional radiographs and the osteoarthritis grading system described by Knirk and Jupiter. Additionally, the evaluation of articular stepoff was performed using pre- and postoperative computed tomography.

RESULTS

Fifteen patients, with a mean follow-up of 6 years (range, 4.1-10.4 years), were included. According to rater 1, 8 cases had no postoperative osteoarthritis progression, 6 cases had progression of 1 grade, and 1 case had progression of 2 grades. According to rater 2, there was no progression in 11 cases, and there was progression of 1 grade in 2 cases and progression of 2 grades in 2 cases. Compared with before the surgery, the patients demonstrated a mean improvement of 14.8 kg (±12.6 kg) in grip strength after the surgery. At the last follow-up, the mean Patient-Rated Wrist Evaluation score was 11.8 (±12.0), the mean Disabilities of the Arm, Shoulder and Hand score was 11.1 (±11.4), and the mean residual pain score on the visual analog scale was 0.8 (±1.0).

CONCLUSIONS

The intermediate-term outcome of 3-dimensional-guided corrective osteotomies for distal radius intra-articular malunions showed excellent patient-reported outcomes and no clinically relevant progression of osteoarthritis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Comparison of an oblique single cut rotation osteotomy with a novel 3D computer-assisted oblique double cut alignment approach

An oblique double-cut rotation osteotomy (ODCRO) enables correcting a complex bone deformation by aligning, in 3D, the distal, middle and proximal bone segments with a target bone, without intersegmental gaps. We propose virtual preoperative planning of an ODCRO. To minimize a residual translation error, we use an optimization algorithm and optimize towards bone length, alignment in the transverse direction, or a balanced reconstruction. We compare the residual alignment error with an oblique single-cut rotation osteotomy using 15 complex bone deformations. The single-cut approach was not feasible in 5 cases, whereas the ODCRO procedure was feasible in all cases. The residual alignment error was smaller for the ODCRO than for the single-cut approach except for one case. In a subset for length reconstruction, the length error of 7.3-21.3 mm was restored to 0.0 mm in 4 of 5 cases, although at the cost of an increased transverse translation. The proposed method renders planning an ODCRO feasible and helps restoring bone alignment and lengthening better than an oblique single-cut rotation osteotomy. Awareness of the challenges and possibilities in preoperative planning of an ODCRO will be of value for future alignment surgery and for patients.

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.

Patient-specific plate for navigation and fixation of the distal radius: a case series

Purpose

Corrective osteotomy of a malunited distal radius conventionally relies on 2D imaging techniques for alignment planning and evaluation. However, this approach results in suboptimal bone repositioning, which is associated with poor patient outcomes. In this case series, we evaluate the use of novel patient-specific plates (PSPs), which feature navigation and fixation of bone segments as preoperatively planned in 3D.

Methods

Ten participants with distal radius malunion underwent CT scans for preoperative alignment planning. Patient-specific guides and plates were designed, 3D-printed, and sterilized for use in corrective surgery of the distal radius. Pre- and postoperative results were compared in regard to clinical, functional, and radiographic outcomes.

Results

The application of a PSP was successful in 7 of the 10 cases. After treatment, the residual alignment error was reduced by approximately 50% compared with conventional treatment. The use of PSPs reduced pain significantly. Pre- and postoperative results were pooled and demonstrated significant correlations between: (1) pain and malpositioning, (2) the range of pro- and supination motion, the MHOQ score, the EQ-5D-5L score and dorsovolar angulation, and (3) MHOQ score and proximodistal translation.

Conclusion

The correlation between malalignment and MHOQ score, EQ-5D-5L score, pain, and range of motion shows that alignment should be restored as well as possible. Compared to the conventional approach, which relies on 2D imaging techniques, corrective osteotomy based on 3D preoperative planning and intraoperative fixation with a PSP has been shown to improve bone alignment and reduce pain.

Level of evidence

IV.

Corrective Osteotomy of Upper Extremity Malunions Using Three-Dimensional Planning and Patient-Specific Surgical Guides: Recent Advances and Perspectives

Malunions of the upper extremity can result in severe functional problems and increase the risk of osteoarthritis. The surgical reconstruction of complex malunions can be technically challenging. Recent advances in computer-assisted orthopedic surgery provide an innovative solution for complex three-dimensional (3-D) reconstructions. This study aims to evaluate the clinical applicability of 3-D computer-assisted planning and surgery for upper extremity malunions. Hence, we provide a summary of evidence on this topic and highlight recent advances in this field. Further, we provide a practical implementation of this therapeutic approach based on three cases of malunited forearm fractures treated with corrective osteotomy using preoperative three-dimensional simulation and patient-specific surgical guides. All three cases, one female (56 years old) and two males (18 and 26 years old), had painful restrictions in range of motion (ROM) due to forearm malunions and took part in clinical and radiologic assessments. Postoperative evaluation of patient outcomes showed a substantial increase in range of motion, reduction of preoperatively reported pain, and an overall improvement of patients' satisfaction. The therapeutic approach used in these cases resulted in an excellent anatomical and functional reconstruction and was assessed as precise, safe, and reliable. Based on current evidence and our results, the 3-D preoperative planning technique could be the new gold standard in the treatment of complex upper extremity malunions in the future.

Three-Dimensional Automated Assessment of the Distal Radioulnar Joint Morphology According to Sigmoid Notch Surface Orientation

PURPOSE

To develop reproducible 3-dimensional measurements for quantification of the distal radioulnar joint (DRUJ) morphology. We hypothesized that automated 3-dimensional measurement of the ulnar variance (UV) and the sigmoid notch (SN) angle would be comparable to those of the reference standard while overcoming some drawbacks of conventional 2-dimensional measurements.

METHODS

Radiological data of healthy forearm bones (radiographs and computed tomography) of 53 adult subjects were included in the study. Automated measurements were developed for assessment of the SN morphology based on 3-dimensional landmarks, incorporating subject-specific estimation of cartilage surface orientation. A common anatomical reference was defined among the different imaging modalities and a comparison of the SN angle and UV measurements was performed in radiographs, computed tomography scans, and 3-dimensional models. Finally, the 3-dimensional UV measurements were evaluated in an experimental setup using 3-dimensional printed bone models.

RESULTS

The automated 3-dimensional measurements of SN subtypes showed a notably larger notch radius (18.9 mm) for negative SN angles compared with positive SN angles in subjects (16.9 mm). Similar UV measurements were obtained in healthy DRUJ morphologies, with a high correlation between radiographs and 3-dimensional measurements for the SN angle (0.77) and UV (0.85). In the experimental setup with pathological radial inclinations, UV was on average 1.13 mm larger in the radiographs compared with the 3-dimensional measurements, and 1.30 mm larger in the cases with pathological palmar tilts. Furthermore, UV radiograph measurements on the modified palmar tilt deviated from the 3-dimensional measurements.

CONCLUSIONS

The developed 3-dimensional automated measurements were able to quantify morphological differences among sigmoid notch subtypes and were comparable to those of the reference standard.

CLINICAL RELEVANCE

The developed methods do not depend on the forearm position or orientation of the distal radius and can be used for 3-dimensional quantification of DRUJ pathologies in 3-dimensional surgical planning.

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.

[3D analysis and computer assisted reconstruction for scaphoid non-union]

The odd shape of the scaphoid is a challenge to our spatial sense. Computer assistance is of an unmatched value when reconstructing a non-united scaphoid: From CT data a true 3-D-model can be generated, fully interactive; thus it can be moved, manipulated and of course also printed for hands-on experience. Comparing the virtual 3-D-models of the nonunion with the healthy contralateral scaphoid, the exact amount of the deformity is calculated which allows for the planning of an anatomically precise reconstruction of the scaphoid shape. Finally, computer generated patient specific instruments will facilitate the implementation of this planning intraoperatively. This proceeding enables us to reconstruct the non-united scaphoid markedly more accurately and with this reliably normalize wrist kinematics. Meanwhile we have applied this technique successfully in more than 50 cases of scaphoid-nonunions presenting with significant deformity.

An Easy and Economical Way to Produce a Three-Dimensional Bone Phantom in a Dog with Antebrachial Deformities

Simple Summary

Accurate planning, for corrective surgeries in case of bone cutting, is necessary to obtain a precise coordination of the skeleton and to achieve the owner’s satisfaction. The present experiment displays a simple and cost-effective technique for surgical planning, utilizing a 3-D bone phantom model in a dog with foreleg deformity.

Abstract

3-D surgical planning for restorative osteotomy is costly and time-consuming because surgeons need to be helped from commercial companies to get 3-D printed bones. However, practitioners can save time and keep the cost to a minimum by utilizing free software and establishing their 3-D printers locally. Surgical planning for the corrective osteotomy of antebrachial growth deformities (AGD) is challenging for several reasons (the nature of the biapical or multiapical conformational abnormalities and lack of a reference value for the specific breed). Pre-operative planning challenges include: a definite description of the position of the center of rotation of angulation (CORA) and proper positioning of the osteotomies applicable to the CORA. In the present study, we demonstrated an accurate and reproducible bone-cutting technique using patient-specific instrumentations (PSI) 3-D technology. The results of the location precision showed that, by using PSIs, the surgeons were able to accurately replicate preoperative resection planning. PSI results also indicate that PSI technology provides a smaller standard deviation than the freehand method. PSI technology performed in the distal radial angular deformity may provide good cutting accuracy. In conclusion, the PSI technology may improve bone-cutting accuracy during corrective osteotomy by providing clinically acceptable margins.

The Use of Virtual Planning and Patient-specific Guides to Correct Complex Deformities of the Foot and Ankle

This article provides an overview regarding the virtual planning and precise execution of corrective osteotomies around the foot and ankle. Based on 3-dimensional data obtained from CT scans, surgeons are able to create a virtual plan of how to correct a complex deformity. This plan is transferred into the production of true patient-specific guides, designed to perform a specific surgical intervention. The authors have extensive experience with this technique and were involved in the development of the method. The current article provides an overview regarding the virtual planning and precise execution of corrective osteotomies around the foot and ankle.

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.

Early Correction of Distal Radius Partial Articular Malunion Leads to Good Long-term Functional Recovery at Mean Follow-up of 4 Years

Background: Distal radius articular step-off or deformity may cause posttraumatic arthritis and poor functional outcome. The purpose of this study was to evaluate pain and functional outcomes in patients with malunited partial articular distal radius fractures who underwent corrective osteotomy. We hypothesized that anatomic restoration of distal radius articular surface after a malunited partial articular distal radius fracture results in improvement in pain and functional measures and delays the development of posttraumatic arthritis. Methods: Seven consecutive patients with mean age of 38 years underwent corrective osteotomy via either a standard dorsal approach or combined dorsal and volar approach. Mean time from injury to corrective osteotomy was 10 weeks. Patients were assessed with respect to Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), forearm and wrist range of motion, pain, and grip strength. Results: At mean follow-up of 44 months, significant improvements in pain scores (7.1-0.9, P < .001), QuickDASH (38.7-11.6, P < .001), grip strength (21.4-30.0 kg, P = .01) were achieved. All range of motion measurements demonstrated significant improvements except forearm pronation. One patient demonstrated radiographic evidence of osteoarthritis but had no pain at final follow-up. No patients required secondary surgery for removal of symptomatic hardware. Conclusions: Based on these findings, we recommend that early corrective osteotomies should be considered in young patients with intra-articular distal radius malunions before considering salvage procedures such as partial or complete wrist arthrodesis.

Incidence of Corrective Procedures After Nonoperatively Managed Distal Radius Fractures in the Elderly

Although the majority distal radius fractures in the elderly are initially managed nonoperatively, the true incidence of subsequent corrective surgery is unknown. The purpose of this study was to determine the incidence and predictors of corrective surgery after conservative management.

Methods

ICD-9 and Current Procedural Terminology codes were queried from the Medicare 5% sample to select patients aged 65 years and older undergoing nonsurgical treatment of distal radius fractures with a minimum 5-year follow-up. Rates of subsequent ipsilateral wrist surgery were correlated against patient age, sex, geographic region, and initial closed reduction.

Results

Five thousand eighty patients with a mean age of 78.3 years were included. Fifty-five patients (1.1%) had undergone subsequent wrist surgery at a median time of 182 days after injury. The youngest cohort (65 to 69 years) had a significantly higher operation rate (1.9%, P = 0.007) than the oldest cohort (80+ years) (0.5%, P = 0.004). There was no notable difference in corrective procedures between sex, geographic region, and initial closed reduction.

Discussion

Once surgical intervention is deemed unnecessary per standard guidelines, the data support successful nonsurgical management in a large majority of patients but highlight a small subset of younger patients who remain at increased risk of requiring additional surgery.

An automatic genetic algorithm framework for the optimization of three-dimensional surgical plans of forearm corrective osteotomies

Three-dimensional (3D) computer-assisted corrective osteotomy has become the state-of-the-art for surgical treatment of complex bone deformities. Despite available technologies, the automatic generation of clinically acceptable, ready-to-use preoperative planning solutions is currently not possible for such pathologies. Multiple contradicting and mutually dependent objectives have to be considered, as well as clinical and technical constraints, which generally require iterative manual adjustments. This leads to unnecessary surgeon efforts and unbearable clinical costs, hindering also the quality of patient treatment due to the reduced number of solutions that can be investigated in a clinically acceptable timeframe. In this paper, we propose an optimization framework for the generation of ready-to-use preoperative planning solutions in a fully automatic fashion. An automatic diagnostic assessment using patient-specific 3D models is performed for 3D malunion quantification and definition of the optimization parameters' range. Afterward, clinical objectives are translated into the optimization module, and controlled through tailored fitness functions based on a weighted and multi-staged optimization approach. The optimization is based on a genetic algorithm capable of solving multi-objective optimization problems with non-linear constraints. The framework outputs a complete preoperative planning solution including position and orientation of the osteotomy plane, transformation to achieve the bone reduction, and position and orientation of the fixation plate and screws. A qualitative validation was performed on 36 consecutive cases of radius osteotomy where solutions generated by the optimization algorithm (OA) were compared against the gold standard solutions generated by experienced surgeons (Gold Standard; GS). Solutions were blinded and presented to 6 readers (4 surgeons, 2 planning engineers), who voted OA solutions to be better in 55% of the time. The quantitative evaluation was based on different error measurements, showing average improvements with respect to the GS from 20% for the reduction alignment and up to 106% for the position of the fixation screws. Notably, our algorithm was able to generate feasible clinical solutions which were not possible to obtain with the current state-of-the-art method.

Intramedullary nailing and plating osteosynthesis in the correction of post-traumatic deformity in late-diagnosed distal radius fractures: a retrospective comparison study

Background

Various surgical modalities are available for correction of deformity in late-diagnosed distal radius fractures. This study compared surgical outcomes between intramedullary nailing and plating osteosynthesis in open-wedge osteotomy.

Methods

We retrospectively reviewed 47 unilateral distal radius fractures that underwent open-wedge osteotomy at more than 4 weeks after injury between 2006 and 2011. A locally resected exuberant callus was used as the bone graft. Two types of fixation were used: intramedullary nail in 22 patients (group A) and locking plate in 25 patients (group B). Radiographic analysis including radial height, radial inclination, and volar tilt were performed preoperatively and 2-year postoperatively. The Modified Mayo Wrist Score (MMWS) was used for functional evaluation and a 10-point visual analog scale (VAS) for residual pain assessment. Patient satisfaction was self-reported as a 5-point scale. Radiographic data, functional outcomes, and surgical complications were compared between the two groups.

Results

All fractures achieved bone union without major complications. The MMWS averaged 84.8 ± 9.7 in group A and 85.2 ± 8.4 in group B, without significant differences (p = 0.436). Instead, significant differences were found in mean wrist flexion (73.6 ± 7.9 vs. 69.6 ± 7.8 degrees; p = 0.042), patient satisfaction (3.6 ± 1.1 vs. 2.9 ± 1.2; p = 0.034), postoperative radial height (11.6 ± 2.6 vs. 10.2 ± 3 mm; p = 0.039) and inclination (20.8 ± 2.8 vs. 17.7 ± 4.1 degrees; p = 0.004), and implant-related complications (9% vs. 36%; p = 0.03). There were no significant differences in other assessment items including postoperative grip strength, pain scale, supination/pronation/extension, volar tilt, correction angles of all three parameters, and general complication rate. Four patients in group A (18%) and 2 in group B (8%) experienced postoperative paresthesia of the surgical hand; no significant difference was noted. All except one patient in group B had full recovery of neurological symptoms.

Conclusions

Open-wedge osteotomy with either an intramedullary nail or locking plate fixation yielded encouraging radiographic and functional outcomes. Intramedullary nail fixation may facilitate restoration of radial height and inclination with better wrist flexion, less implant-related complications, and greater patient satisfaction.

Three-Dimensional Corrective Osteotomy for Malunited Fractures of the Upper Extremity Using Patient-Matched Instruments: A Prospective, Multicenter, Open-Label, Single-Arm Trial

BACKGROUND

Medical image processing has facilitated simulation of 3-dimensional (3-D) corrective osteotomy, and 3-D rapid prototyping technology has further enabled the manufacturing of patient-matched surgical guides and implants (patient-matched instruments, or PMIs). However, 3-D corrective osteotomy using these technologies has not been the standard procedure. We aimed to prospectively verify the efficacy and safety of PMIs in corrective osteotomy for deformities of the upper extremity.

METHODS

We enrolled 16 patients with a total of 17 bone deformities in the upper extremity. Eight patients had distal radial malunion; 5, distal humeral malunion; and 3, forearm diaphyseal malunion. All cases underwent 3-D corrective osteotomy with PMIs. The primary end point was the residual maximum deformity angle (MDA), which was calculated from 2 deformity angles-1 on the anteroposterior and 1 on the lateral postoperative radiograph. Secondary end points included the deformity angle on radiographs, 3-D error between the preoperative planning model and the postoperative result, range of motion, grip strength, pain measured with a visual analog scale (VAS), patient satisfaction, and Disabilities of the Arm, Shoulder and Hand (DASH) score.

RESULTS

The average MDA significantly improved from 25.5° preoperatively to 3.3° at the final follow-up (p < 0.001). The angular deformity was within 5° in all cases, except for 1 with distal radial malunion who had a higher angle on the anteroposterior radiograph. The error between the correction seen on the postoperative 3-D bone model and the planned correction was <1° and <1 mm. Flexion and extension of the wrist and pronation of the forearm of the patients treated for distal radial malunion improved significantly, and pronation improved for those treated for forearm diaphyseal malunion. The average VAS score, grip strength, and DASH score significantly improved as well. Of the 16 patients, 15 were very satisfied or satisfied with the outcomes.

CONCLUSIONS

Corrective osteotomy using PMIs achieved accurate correction and good functional recovery in the upper extremity. Although our study was limited to cases without any deformity on the contralateral side, 3-D corrective osteotomy using PMIs resolved treatment challenges for complex deformities in upper extremities.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Computer-Assisted Three-Dimensional Corrective Osteotomy for Malunited Fractures of the Distal Radius Using Prefabricated Bone Graft Substitute

BACKGROUND

Three-dimensional computed tomography (3D-CT) imaging has enabled more accurate preoperative planning. The purpose of this study was to investigate the results of a novel, computer-assisted, 3D corrective osteotomy using prefabricated bone graft substitute to treat malunited fractures of the distal radius.

METHODS

We investigated 19 patients who underwent the computer-assisted 3D corrective osteotomy for a malunited fracture of the distal radius after the operation was stimulated with CT data. A prefabricated bone graft substitute corresponding to the patient's bone defect was implanted and internal fixation was performed using a plate and screws. We compared postoperative radiographic parameters of the patient's operated side with their sound side and analyzed clinical outcomes using Mayo wrist score.

RESULTS

All patients achieved bone union on X-ray imaging at final follow-up. The mean differences of palmar tilt, radial inclination and ulnar variance between the operation side and the sound side were 4.3°, 2.3° and 1.2 mm, respectively. The Mayo wrist score was fair in 4 patients and poor in 15 patients before surgery. At the final follow-up after surgery, the scores improved to excellent in 3 patients, good in 11 patients and fair in 5 patients. There were two patients with correction loss at the final follow-up, but no patient complained of hand joint pain.

CONCLUSIONS

We believe that computer-assisted 3D corrective osteotomy using prefabricated bone graft substitute achieved good results because it worked as a guide to the accurate angle.

Corrective Osteotomies of Phalangeal and Metacarpal Malunions Using Patient-Specific Guides: CT-Based Evaluation of the Reduction Accuracy

BACKGROUND

Surgical planning of corrective osteotomies is traditionally based on conventional radiographs and clinical findings. In the past 10 years, 3-dimensional (3D) preoperative planning approaches with patient-specific guides have been developed. However, the application of this technology to posttraumatic deformities of the metacarpals and phalangeal bones has not yet been investigated. Our goal was to evaluate the feasibility of the surgical application to the latter and to evaluate the extent and precision of correction.

METHODS

We present results of 6 patients (8 osteotomies) treated with phalangeal or metacarpal corrective osteotomy. Deformities were located in the third ray in 1, fourth ray in 3, and fifth ray in 4 cases. Six malunited metacarpal bones (1 intra-articular) and 2 deformed proximal phalanges were treated. Computer-based 3D preoperative planning using the contralateral hand as a template allowed the production of 3D-printed patient-specific guides that were used intraoperatively for navigation. The precision of the reduction was assessed using pre- and postoperative computed tomography by comparing the postoperative bone model with the preoperatively simulated osteotomy. Range of motion and grip strength were documented pre- and postoperatively.

RESULTS

The mean follow-up time was 6 months (range: 5-11 months). Rotational deformity was reduced from a mean of 10.0° (range: 7.2°-19.3°) preoperatively to 2.3° (range: 0.7°-3.7°) postoperatively, and translational incongruency decreased from a mean of 1.4 mm (range: 0.7-2.8 mm) to 0.4 mm (range: 0.1-0.9 mm).

CONCLUSION

Preliminary results indicate that a precise reduction for corrective osteotomies of metacarpal and phalangeal bones can be achieved by using 3D planning and patient-specific guides.

Surgical Technique of Corrective Osteotomy for Malunited Distal Radius Fracture Using the Computer-Simulated Patient Matched Instrument

The conventional corrective osteotomy for malunited distal radius fracture that employs dorsal approach and insertion of a trapezoidal bone graft does not always lead to precise correction or result in a satisfactory surgical outcome. Corrective osteotomy using a volar locking plate has recently become an alternative technique. In addition, the use of patient-matched instrument (PMI) via computed tomography simulation has been developed and is expected to simplify surgical procedures and improve surgical precision. The use of PMI makes it possible to accurately position screw holes prior to the osteotomy and simultaneously perform the correction and place the volar locking plate once the osteotomy is completed. The bone graft does not necessarily require a precise block form, and the problem of the extensor tendon contacting the dorsal plate is avoided. Although PMI placement and soft tissue release technique require some degree of specialized skill, they comprise a very useful surgical procedure. On the other hand, because patients with osteoporosis are at risk of peri-implant fracture, tandem ulnar shortening surgery should be considered to avoid excessive lengthening of the radius.

Improving accuracy of opening-wedge osteotomies of distal radius using a patient-specific ramp-guide technique

BACKGROUND

Opening-wedge osteotomies of the distal radius, performed with three-dimensional printed patient-specific instruments, are a promising technique for accurate correction of malunions. Nevertheless, reports of residual malalignments and discrepancies in the plate and screw position from the planned fixation exist. Consequently, we developed a patient-specific ramp-guide technique, combining navigation of plate positioning, osteotomy cutting, and reduction. The aim of this study is to compare the accuracy of navigation of three-dimensional planned opening-wedge osteotomies, using a ramp-guide, over state-of-the-art guide techniques relying solely on pre-drilled holes.

METHODS

A retrospective analysis was carried out on opening-wedge osteotomies of the distal radius, performed between May 2016 and April 2017, with patient-specific instruments. Eight patients were identified in which a ramp-guide for the distal plate fixation was used. We compared the reduction accuracy with a control group of seven patients, where the reduction was performed with pre-drilled screw holes placed with the patient-specific instruments. The navigation accuracy was assessed by comparing the preoperative plans with the postoperative segmented, computed tomography scans. The accuracy was expressed using a 3D angle and in measurements of all six degrees of freedom (3 translations, 3 rotations), with respect to an anatomical coordinate system.

RESULTS

The duration of the surgery of the ramp-guide group was significantly shorter compared to the control group. Significantly less rotational and translational residual malalignment error was observed in the open-wedged osteotomies, where patient-specific instruments with ramp-guides were used. On average, a residual rotational malalignment error of 2.0° (± 2.2°) and a translational malalignment error of 0.6 mm (± 0.2 mm) was observed in the ramp-guide group, as compared to the 4.2° (± 15.0°) and 1.0 mm (± 0.4 mm) error in the control group. The used plate was not significantly positioned more accurately, but significantly fewer screws (15.6%) were misaligned in the distal fragment compared to the control group (51.9%).

CONCLUSION

The use of the presented ramp-guide technique in opening-wedge osteotomies is improving reduction accuracy, screw position, and surgical duration, compared to the existing patient-specific instrument based navigation methods.

Positioning accuracy of a patient-tailored rimmed wedge implant for corrective osteotomy of the distal radius

Conventional corrective osteotomy surgery is based on 2-D imaging for planning and evaluation of bone positioning. In this feasibility study we propose and evaluate the use of 3-D preoperative planning and design of a custom rimmed wedge to be inserted into the osteotomy gap. The shape of the wedge provides 3-D bone positioning as planned, while the rims keep the bone segments in place. The method is evaluated experimentally using 3-D printed radii specimens of five different malunion patients, as well as in a human cadaver specimen. Positioning was accurate and reproducible showing residual displacements along the x-, y- and z-axes of (mean ± SD): (-0.19 ± 0.75, 0.38 ± 1.09, and 0.47 ± 0.48) mm and residual rotations about these axes of (mean ± SD): (-1.22 ± 1.66, -0.40 ± 0.93, and -0.33 ± 1.50)° for artificial bone specimens. The cadaver experiment showed similar displacements along the x-, y- and z-axes (-0.17, 1.11, and -0.35) mm and residual rotations about these axes (-2.93, -1.53, and 2.31)°. Positioning by inserting a rimmed wedge in corrective osteotomy surgery is accurate with residual errors comparable to bilateral differences. The method seems promising for future utilization in corrective osteotomy surgery and may ultimately render the procedure minimally invasive.

Preoperative Computer Simulation and Patient-specific Guides are Safe and Effective to Correct Forearm Deformity in Children

BACKGROUND

Posttraumatic and congenital forearm deformities in children can be difficult to appreciate in all planes. In cases of distal radioulnar joint instability and loss of forearm rotation, surgical correction is challenging. Advances in 3-dimensional printing allow creation of custom guides at a reasonable cost, enabling precise correction of the deformity in all planes.

METHODS

Nineteen children with deformity of the forearm had corrective osteotomies performed using preoperative 3-dimensional computer modeling and patient-specific surgical guides. Surgicase software was used for 3-dimensional planning of the corrective osteotomy, by superimposing a mirror image of the unaffected side as a template. Based upon this planning, patient-specific surgical guides were manufactured. Radiographic and clinical outcomes were assessed.

RESULTS

Three patients had a diagnosis of multiple hereditary exostoses, and one of Madelung's deformity. The remaining 15 patients had a diagnosis of fracture malunion. Average preoperative angulation of both the radius and ulna was 23 degrees. For the patients with fracture malunions, the time from injury to surgery ranged from 6 months to 8 years. Twelve patients underwent osteotomies of both the radius and ulna, 5 had osteotomies of the radius alone, and 2 had a single osteotomy of the ulna only. All osteotomies went on to unite and no patient lost range of motion. Preoperative arc of forearm rotation averaged 101 degrees (range 0 to 180 degrees). Postoperatively, this improved to 133 degrees (range 85 to 180 degrees). Eight patients had distal radioulnar instability preoperatively, all of which normalized after surgery. There were 4 complications: 1 hypertrophic scar, 1 subject with extensor pollicis longus weakness, and 2 transient sensory losses in the superficial radial nerve distribution.

CONCLUSIONS

This case series demonstrates that 3-dimensional computer modeling permits complex and multiple osteotomies to be done safely to achieve deformity correction in children. Limitations in forearm rotation and distal radioulnar malalignment can be reliably improved using this technique.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

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.

Three-dimensional full-scale bone modeling for preoperative simulation of surgery in patients with elbow contractures due to bone deformities

It is often difficult to treat for elbow contractures by malformation of bones. We planned a mobilization of elbow with using three‐dimensional full‐scale bone modeling. We found it was effective to use it in preoperative planning because we could recognize the elements of contractures in every deformity.

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.

Patient-Specific Orthopaedic Implants

Patient-specific orthopaedic implants are emerging as a clinically promising treatment option for a growing number of conditions to better match an individual's anatomy. Patient-specific implant (PSI) technology aims to reduce overall procedural costs, minimize surgical time, and maximize patient outcomes by achieving better biomechanical implant fit. With this commercially-available technology, computed tomography or magnetic resonance images can be used in conjunction with specialized computer programs to create preoperative patient-specific surgical plans and to develop custom cutting guides from 3-D reconstructed images of patient anatomy. Surgeons can then place these temporary guides or "jigs" during the procedure, allowing them to better recreate the exact resections of the computer-generated surgical plan. Over the past decade, patient-specific implants have seen increased use in orthopaedics and they have been widely indicated in total knee arthroplasty, total hip arthroplasty, and corrective osteotomies. Patient-specific implants have also been explored for use in total shoulder arthroplasty and spinal surgery. Despite their increasing popularity, significant support for PSI use in orthopaedics has been lacking in the literature and it is currently uncertain whether the theoretical biomechanical advantages of patient-specific orthopaedic implants carry true advantages in surgical outcomes when compared to standard procedures. The purpose of this review was to assess the current status of patient-specific orthopaedic implants, to explore their future direction, and to summarize any comparative published studies that measure definitive surgical characteristics of patient-specific orthopaedic implant use such as patient outcomes, biomechanical implant alignment, surgical cost, patient blood loss, or patient recovery.

Three-dimensional postoperative accuracy of extra-articular forearm osteotomies using CT-scan based patient-specific surgical guides

BACKGROUND

Computer assisted corrective osteotomy of the diaphyseal forearm and the distal radius based on computer simulation and patient-specific guides has been described as a promising technique for accurate reconstruction of forearm deformities. Thereby, the intraoperative use of patient-specific drill and cutting guides facilitate the transfer of the preoperative plan to the surgery. However, the difference between planned and performed reduction is difficult to assess with conventional radiographs. The aim of this study was to evaluate the accuracy of this surgical technique based on postoperative three-dimensional (3D) computed tomography (CT) data.

METHODS

Fourteen patients (mean age 23.2 (range, 12-58) years) with an extra-articular deformity of the forearm had undergone computer assisted corrective osteotomy with the healthy anatomy of the contralateral uninjured side as a reconstruction template. 3D bone surface models of the pathological and contralateral side were created from CT data for the computer simulation. Patient-specific drill and cutting guides including the preoperative planned screw direction of the angular-stable locking plates and the osteotomy planes were used for the intraoperative realization of the preoperative plan. There were seven opening wedge osteotomies and nine closing wedge (or single-cut) osteotomies performed. Eight-ten weeks postoperatively CT scans were obtained to assess bony consolidation and additionally used to generate a 3D model of the forearm. The simulated osteotomies- preoperative bone models with simulated correction - and the performed osteotomies - postoperative bone models - were analyzed for residual differences in 3D alignment.

RESULTS

On average, a significant higher residual rotational deformity was observed in opening wedge osteotomies (8.30° ± 5.35°) compared to closing wedge osteotomies (3.47° ± 1.09°). The average residual translation was comparable small in both groups, i.e., below 1.5 mm and 1.1 mm for opening and closing wedge osteotomies, respectively.

CONCLUSIONS

The technique demonstrated high accuracy in performing closing wedge (or single-cut) osteotomies. However, for opening wedge osteotomies with extensive lengthening, probably due to the fact that precise reduction was difficult to achieve or maintain, the final corrections were less accurate.

A less invasive distal osteotomy of the radius for malunited dorsally displaced extra-articular fractures

A less invasive corrective osteotomy for symptomatic post-traumatic deformity of the distal radius was done in 12 patients. They were followed up for an average of 3.7 years. The indications for correction were based on the patients' level of activities, pain, functional limitations, loss of grip strength or deformity occurring with an extra-articular rotational malunion of the distal end of the radius. The procedure included a dorsal open wedge osteotomy through a dorsal incision in which the fulcrum of rotation, or hinge, was located at the palmar cortex, and stabilized with an extra- and intramedullary fixed angle device. The bone defect was replaced with autologous morsellized iliac bone graft. The final outcome was graded as very good in eight patients, good in two and fair in two. Level of evidence: IV.

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

In corrective osteotomy of the radius, detailed preoperative planning is essential to optimising functional outcome. However, complex malunions are not completely addressed with conventional preoperative planning. Computer-assisted preoperative planning may optimise the results of corrective osteotomy of the radius. We analysed the pre- and postoperative radiological result of computer-assisted 3D planned corrective osteotomy in a series of patients with a malunited radius and assessed postoperative function. We included eight patients aged 13–64 who underwent a computer-assisted 3D planned corrective osteotomy of the radius for the treatment of a symptomatic radius malunion. We evaluated pre- and postoperative residual malpositioning on 3D reconstructions as expressed in six positioning parameters (three displacements along and three rotations about the axes of a 3D anatomical coordinate system) and assessed postoperative wrist range of motion. In this small case series, dorsopalmar tilt was significantly improved (p = 0.05). Ulnoradial shift, however, increased by the correction osteotomy (6 of 8 cases, 75 %). Postoperative 3D evaluation revealed improved positioning parameters for patients in axial rotational alignment (62.5 %), radial inclination (75 %), proximodistal shift (83 %) and volodorsal shift (88 %), although the cohort was not large enough to confirm this by statistical significance. All but one patient experienced improved range of motion (88 %). Computer-assisted 3D planning ameliorates alignment of radial malunions and improves functional results in patients with a symptomatic malunion of the radius. Further development is required to improve transfer of the planned position to the intra-operative bone.

Level of evidence IV.

Is Bone Grafting Necessary in the Treatment of Malunited Distal Radius Fractures?

Background Open wedge osteotomy with bone grafting and plate fixation is the standard procedure for the correction of malunited distal radius fractures. Bone grafts are used to increase structural stability and to enhance new bone formation. However, bone grafts are also associated with donor site morbidity, delayed union at bone-graft interfaces, size mismatch between graft and osteotomy defect, and additional operation time. Purpose The goal of this study was to assess bone healing and secondary fracture displacement in the treatment of malunited distal radius fractures without the use of bone grafting. Methods Between January 1993 and December 2013, 132 corrective osteotomies and plate fixations without bone grafting were performed for malunited distal radius fractures. The minimum follow-up time was 12 months. Primary study outcomes were time to complete bone healing and secondary fracture displacement. Preoperative and postoperative radiographs during follow-up were compared with each other, as well as with radiographs of the uninjured side. Results All 132 osteotomies healed. In two cases (1.5%), healing took more than 4 months, but reinterventions were not necessary. No cases of secondary fracture displacement or hardware failure were observed. Significant improvements in all radiographic parameters were shown after corrective osteotomy and plate fixation. Conclusion This study shows that bone grafts are not required for bone healing and prevention of secondary fracture displacement after corrective osteotomy and plate fixation of malunited distal radius fractures. Level of evidence Therapeutic, level IV, case series with no comparison group.

Management of complications of distal radius fractures

Treating a fracture of the distal radius may require the surgeon to make a difficult decision between surgical treatment and nonsurgical management. The use of surgical fixation has recently increased because of complications associated with conservative treatment. However, conservative action may be necessary depending on certain patient factors. The treating surgeon must be aware of the possible complications associated with distal radius fracture treatments to prevent their occurrence. Prevention can be achieved with a proper understanding of the mechanism of these complications. This article discusses the most recent evidence on how to manage and prevent complications following a fracture of the distal radius.

Precision of image-based registration for intraoperative navigation in the presence of metal artifacts: Application to corrective osteotomy surgery

Navigation for corrective osteotomy surgery requires patient-to-image registration. When registration is based on intraoperative 3-D cone-beam CT (CBCT) imaging, metal landmarks may be used that deteriorate image quality. This study investigates whether metal artifacts influence the precision of image-to-patient registration, either with or without intermediate user intervention during the registration procedure, in an application for corrective osteotomy of the distal radius. A series of 3-D CBCT scans is made of a cadaver arm with and without metal landmarks. Metal artifact reduction (MAR) based on inpainting techniques is used to improve 3-D CBCT images hampered by metal artifacts. This provides three sets of images (with metal, with MAR, and without metal), which enable investigating the differences in precision of intraoperative registration. Gray-level based point-to-image registration showed a better correlation coefficient if intraoperative images with MAR are used, indicating a better image similarity. The precision of registration without intermediate user intervention during the registration procedure, expressed as the residual angulation and displacement error after repetitive registration was very low and showed no improvement when MAR was used. By adding intermediate user intervention to the registration procedure however, precision was very high but was not affected by the presence of metal artifacts in the specific application.

Load transfer at the distal ulna following simulated distal radius fracture malalignment

PURPOSE

To measure the effects of distal radius malalignment on loading at the distal ulna.

METHODS

Using an adjustable mechanism to simulate angulated and translated malalignments, clinically relevant distal radius deformities were simulated in a cadaveric model. A custom-built load cell was inserted just proximal to the native ulna head to measure the resultant force and torque in the distal ulna. Loads were measured before and after transecting the triangular fibrocartilage complex (TFCC).

RESULTS

There was an increase in distal ulna load and torque with increasing dorsal translation and angulation. Combined conditions of angulation and translation increased force and torque in the distal ulna to a greater extent than with either condition in isolation. Transecting the TFCC resulted in a reduction in distal ulna load and torque.

CONCLUSIONS

A progressive increase in load at the distal ulna was observed with increasing severity of malalignment, which may be an important contributor to residual ulnar wrist pain and dysfunction. However, no clear-cut threshold of malalignment of a dorsally angulated and translated distal radius fracture was identified. These observations suggest that radius deformities cause articular incongruity, which increases TFCC tension and distal radioulnar joint load. Cutting of the TFCC decreased distal ulna loading, likely by releasing the articular constraining effect of the TFCC on the distal radioulnar joint, allowing the radius to rotate more freely with respect to the ulna.

CLINICAL RELEVANCE

Anatomical reduction of a distal radius fracture minimizes the forces in the distal ulna and may reduce residual ulnar wrist pain and dysfunction.

Patient-specific distal radius locking plate for fixation and accurate 3D positioning in corrective osteotomy

Preoperative three-dimensional planning methods have been described extensively. However, transferring the virtual plan to the patient is often challenging. In this report, we describe the management of a severely malunited distal radius fracture using a patient-specific plate for accurate spatial positioning and fixation. Twenty months postoperatively the patient shows almost painless reconstruction and a nearly normal range of motion.

A laboratory comparison of computer navigation and individualized guides for distal radius osteotomy

PURPOSE

This article presents the results of a multiuser, randomized laboratory trial comparing the accuracy and precision of image-based navigation against individualized guides for distal radius osteotomy (DRO).

METHODS

Six surgeons each performed four DROs using image-based navigation and four DROs using individualized guides in a laboratory setting with plastic phantom replicas of radii from patients who had received DRO as treatment for radial deformity. Time required and correction errors of ulnar variance, radial inclination, and volar tilt were measured.

RESULTS

There were no statistically significant differences in the average correction errors. There was a statistically significant difference in the standard deviation of ulnar variance error (2.0 mm for navigation vs. 0.6 mm for guides). There was a statistically significant difference in the standard deviation of radial inclination error ([Formula: see text] for navigation vs. [Formula: see text] for guides). There were statistically significant differences in the times required (705 s for navigation vs. 214 s for guides) and their standard deviations (144 s for navigation vs. 98 s for guides).

CONCLUSIONS

Compared to navigated DRO, individualized guides were easier to use, faster, and produced more precise correction of ulnar variance and radial inclination. The combination of true three-dimensional planning, ease of use, and accurate and precise corrective guidance makes the individualized guide technique a promising approach for performing corrective osteotomy of the distal radius.

Three-dimensional correction of distal radius intra-articular malunions using patient-specific drill guides

PURPOSE

To analyze the feasibility of combining computer-assisted 3-dimensional planning with patient-specific drill guides and to evaluate this technology's surgical outcomes for distal radius intra-articular malunions.

METHODS

Six symptomatic patients with intra-articular malunions of the distal radius with a stepoff of more than 2 mm were treated with an outside-in corrective osteotomy. The described cases consist of 2 malunited volar Barton fractures, 2 radial styloid fractures, 1 AO-type C1 fracture, and 1 die-punch fracture. The osteotomies were guided by 3-dimensionally generated aiming guides that allowed precise cutting and the reduction of up to 2 fragments. All 6 patients were examined clinically and radiologically after 1 year. The surgical outcomes were quantitatively analyzed by comparing the preoperative and postoperative computed tomographic data.

RESULTS

In all 6 cases, the osteotomies were consolidated 8 weeks postoperatively. After 1 year, 4 patients were pain-free, 1 had mild pain, and 1 experienced moderate pain during heavy work. Wrist motion and grip strength were improved in all patients. The postoperative radiographs showed no articular stepoff or degenerative changes.

CONCLUSIONS

Patient-specific aiming guides provided a reliable method to correct intra-articular malunions of the distal radius. This technique allows the surgeon to safely perform difficult intra-articular osteotomies and may help limit the need for salvage procedures such as partial or complete wrist arthrodesis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Accuracy of 3D Virtual Planning of Corrective Osteotomies of the Distal Radius

Corrective osteotomies of the distal radius for symptomatic malunion are time-tested procedures that rely on accurate corrections. Patients with combined intra- and extra-articular malunions present a challenging deformity. Virtual planning and patient-specific instruments (PSIs) to transfer the planning into the operating room have been used both to simplify the surgery and to make it more accurate. This report focuses on the clinically achieved accuracy in four patients treated between 2008 and 2012 with virtual planning and PSIs for a combined intra- and extraarticular malunion of the distal radius. The accuracy of the correction is quantified by comparing the virtual three-dimensional (3D) planning model with the postoperative 3D bone model. For the extraarticular malunion the 3D volar tilt, 3D radial inclination and 3D ulnar variance are measured. The volar tilt is undercorrected in all cases with an average of -6 ± 6°. The average difference between the postoperative and planned 3D radial inclination was -1 ± 5°. The average difference between the postoperative and planned 3D ulnar variances is 0 ± 1 mm. For the evaluation of the intraarticular malunion, both the arc method of measurement and distance map measurement are used. The average postoperative maximum gap is 2.1 ± 0.9 mm. The average maximum postoperative step-off is 1.3 ± 0.4 mm. The average distance between the postoperative and planned articular surfaces is 1.1 ± 0.6 mm as determined in the distance map measurement. There is a tendency to achieve higher accuracy as experience builds up, both on the surgeon's side and on the design engineering side. We believe this technology holds the potential to achieve consistent accuracy of very complex corrections.

Computer-assisted percutaneous scaphoid fixation: concepts and evolution

Background The treatment for undisplaced scaphoid waist fractures has evolved from conventional cast immobilization to percutaneous screw insertion. Percutaneous fixation reduces some of the risks of open surgery, but can be technically demanding and carries the risk of radiation exposure. Recently, computer-assisted percutaneous scaphoid fixation (CAPSF) has been gaining interest. Materials and Methods Conventional percutaneous scaphoid fixation is performed under fluoroscopic guidance and involves insertion of a guide wire along the length of the scaphoid to facilitate placement of a cannulated screw. Adapting computer-assisted techniques for scaphoid fixation poses several unique challenges including patient tracking and registration. Results To date, five groups have successfully implemented systems for CAPSF. These systems have implemented wrist immobilization strategies to resolve the issue of patient tracking and have developed unique guidance techniques incorporating 2D fluoroscope, cone-beam CT, and ultrasound, to circumvent patient-based registration. Conclusions Computer-aided percutaneous pinning of scaphoid waist fractures can significantly reduce radiation exposure and has the potential to improve the accuracy of this procedure. This article reviews the rationale for, and the evolution of, CAPSF and describes the key principles of computer-assisted technology.