Distal radius osteotomy with volar locking plates based on computer simulation

Intra-Articular Corrective Osteotomy for Distal Radial Intra-Articular Malunion Using Patient-Matched Instruments: A Prospective, Multicenter, Open-Label, Single-Arm Trial

Background

Corrective osteotomy for intra-articular malunion is a challenging procedure. However, recent advancements, including patient-matched instruments created on the basis of preoperative computer simulation, enable accurate intra-articular correction. We hypothesized that intra-articular corrective osteotomy using patient-matched instruments for the treatment of distal radial intra-articular malunion would reduce intra-articular deformity and restore wrist function at 12 months of follow-up.

Methods

This prospective study included 12 patients with distal radial intra-articular malunion who underwent intra-articular corrective osteotomy external to the joint using patient-matched instruments. The primary end point was the maximum step-off on the articular surface of the distal radius, measured with use of computed tomography (CT), with an expected postoperative value of ≤1.5 mm. The secondary end points included the gap of the articular surface; range of motion; grip strength; pain evaluated using a visual analog scale (VAS); patient satisfaction; Disabilities of the Arm, Shoulder and Hand (DASH) score; and Patient-Rated Wrist Evaluation (PRWE) score. A mean postoperative step-off of ≤1.5 mm for the primary end point was assessed with use of the 1-sample t test. The secondary end points were assessed with use of the Dunnett multiple comparison test.

Results

The average step-off significantly improved from 3.75 ± 1.04 mm preoperatively to 0.51 ± 0.40 mm at the 52-week postoperative follow-up and was maintained within 1.5 mm. The average wrist and forearm range of motion, VAS score, grip strength, DASH score, and PRWE score significantly improved. Eleven patients were either very satisfied or satisfied with their outcomes.

Conclusions

The use of patient-matched instruments could contribute to improving postoperative outcomes of intra-articular corrective osteotomy procedures involving the distal radius.

Level of Evidence

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

Functional outcome of 2-D- and 3-D-guided corrective forearm osteotomies: a systematic review

We performed a systematic review to compare conventional (2-D) versus 3-D-guided corrective osteotomies regarding intraoperative results, patient-reported outcome measures, range of motion, incidence of complications and pain score. PubMed (MEDLINE), Embase and Cochrane CENTRAL were searched, and 53 articles were included, reporting 1257 patients undergoing forearm corrective osteotomies between 2010 and 2022. 3-D-guided surgery resulted in a greater improvement in median Disabilities of the Arm, Shoulder and Hand (DASH) score (28, SD 7 vs. 35, SD 5) and fewer complications (12% vs. 6%). Pain scores and range of motion were similar between 3-D-guided and conventional surgery. 3-D-guided corrective osteotomy surgery appears to improve patient-reported outcomes and reduce complications compared to conventional methods. However, due to the limited number of comparative studies and the heterogeneity of the studies, a large randomized controlled trial is needed to draw definitive conclusions.Level of evidence: III.

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.

Pediatric Forearm Malunions

The aim of this article is to review the evaluation and management of pediatric forearm malunions. Acceptable parameters for nonoperative management of pediatric forearm fractures are reviewed, followed by clinical and imaging workups of malunions and decision-making points for treatment. The landscape of available technology for planning and execution of corrective osteotomy is discussed. Several cases of pediatric forearm malunion are presented, along with surgical and functional outcomes. Recommendations are given regarding the authors' preferred approach for management of pediatric forearm malunions.

3D-assisted corrective osteotomies of the distal radius: a comparison of pre-contoured conventional implants versus patient-specific implants

PURPOSE

There is a debate whether corrective osteotomies of the distal radius should be performed using a 3D work-up with pre-contoured conventional implants (i.e., of-the-shelf) or patient-specific implants (i.e., custom-made). This study aims to assess the postoperative accuracy of 3D-assisted correction osteotomy of the distal radius using either implant.

METHODS

Twenty corrective osteotomies of the distal radius were planned using 3D technologies and performed on Thiel embalmed human cadavers. Our workflow consisted of virtual surgical planning and 3D printed guides for osteotomy and repositioning. Subsequently, left radii were fixated with patient-specific implants, and right radii were fixated with pre-contoured conventional implants. The accuracy of the corrections was assessed through measurement of rotation, dorsal and radial angulation and translations with postoperative CT scans in comparison to their preoperative virtual plan.

RESULTS

Twenty corrective osteotomies were executed according to their plan. The median differences between the preoperative plan and postoperative results were 2.6° (IQR: 1.6-3.9°) for rotation, 1.4° (IQR: 0.6-2.9°) for dorsal angulation, 4.7° (IQR: 2.9-5.7°) for radial angulation, and 2.4 mm (IQR: 1.3-2.9 mm) for translation of the distal radius, thus sufficient for application in clinical practice. There was no significant difference in accuracy of correction when comparing pre-contoured conventional implants with patient-specific implants.

CONCLUSION

3D-assisted corrective osteotomy of the distal radius with either pre-contoured conventional implants or patient-specific implants results in accurate corrections. The choice of implant type should not solely depend on accuracy of the correction, but also be based on other considerations like the availability of resources and the preoperative assessment of implant fitting.

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.

The presence of 3D printing in orthopedics: A clinical and material review

The field of additive manufacturing, 3D printing (3DP), has experienced an exponential growth over the past four decades, in part due to increased accessibility. Developments including computer-aided design and manufacturing, incorporation of more versatile materials, and improved printing techniques/equipment have stimulated growth of 3DP technologies within various industries, but most specifically the medical field. Alternatives to metals including ceramics and polymers have been garnering popularity due to their resorbable properties and physiologic similarity to extracellular matrix. 3DP has the capacity to utilize an assortment of materials and printing techniques for a multitude of indications, each with their own associated benefits. Within the field of medicine, advances in medical imaging have facilitated the integration of 3DP. In particular, the field of orthopedics has been one of the earliest medical specialties to implement 3DP. Current indications include education for patients, providers, and trainees, in addition to surgical planning. Moreover, further possibilities within orthopedic surgery continue to be explored, including the development of patient-specific implants. This review aims to highlight the use of current 3DP technology and materials by the orthopedic community, and includes comments on current trends and future direction(s) within the field.

Clinical Applications of Three-Dimensional Printing in Upper Extremity Surgery: A Systematic Review

Three-dimensional printing for medical applications in surgery of the upper extremity has gained in popularity as reflected by the increasing number of publications. This systematic review aims to provide an overview of the clinical use of 3D printing in upper extremity surgery.

METHODS

We searched the databases PubMed and Web of Science for clinical studies that described clinical application of 3D printing for upper extremity surgery including trauma and malformations. We evaluated study characteristics, clinical entity, type of clinical application, concerned anatomical structures, reported outcomes, and evidence level.

RESULTS

We finally included 51 publications with a total of 355 patients, of which 12 were clinical studies (evidence level II/III) and 39 case series (evidence level IV/V). The types of clinical applications were for intraoperative templates (33% of a total of 51 studies), body implants (29%), preoperative planning (27%), prostheses (15%), and orthoses (1%). Over two third of studies were linked to trauma-related injuries (67%).

CONCLUSION

The clinical application of 3D printing in upper extremity surgery offers great potential for personalized approaches to aid in individualized perioperative management, improvement of function, and ultimately help to benefit certain aspects in the quality of life.

3D-printed patient specific instruments for corrective osteotomies of the lower extremity

3D-printing has become a promising adjunct in orthopedic surgery over the past years. A significant drop in costs and increased availability of the required hardware and software needed for using the technique, have resulted in a relatively fast adaptation of 3D-printing techniques for various indications. In this review, the role of 3D-printing for deformity corrections of the lower extremity is described.

Corrective Osteotomy with Volar and Dorsal Fixation for Malunion of Intra-Articular Fracture of the Distal Radius: A Retrospective Study

OBJECTIVES

Although corrective osteotomy with volar or dorsal plate fixation can treat malunion of distal radius fractures, each has its own disadvantages. Little is currently known on whether dorsal fixation combined with volar fixation may further improve recovery. This study aimed to evaluate the clinical value of corrective osteotomy combined with volar and dorsal plate fixation in patients with malunion of intra-articular fractures of the distal radius.

METHODS

Seventeen patients with malunion of intra-articular fractures of the distal radius treated with corrective osteotomy with volar and dorsal plate fixation from 1 January 2016 to 31 November 2018 were retrospectively analyzed. The enrolled patients included seven males and 10 females with an average age of 54.9 years (range: 36-70 years). The radiographic parameters, including the radial length, the radial inclination angle, the ulnar variance, and the volar tilt, as well as clinical outcomes, including wrist and forearm range of motion (ROM), grip strength, the Mayo Modified Wrist Score (MMWS), and the disabilities of the Arm, Shoulder, and Hand (DASH) score, were examined at 3 months and 18 months after operation and compared with the preoperative state. The paired t-test was used for statistical analysis.

RESULTS

After corrective osteotomy combined with volar and dorsal plate fixation, all included patients were followed up for 18 months, and there was no surgical site infection. Patients reported postoperative pain due to the irritation of extensor tendon (two cases) and wrist arthritis (two cases). The radial length increased from 1.34 ± 2.34 mm to 9.25 ± 2.65 mm and 9.03 ± 2.47 mm at 3 months and 18 months postoperatively (t = 8.257, 7.954, all p < 0.05). The radial inclination angle increased from 6.45° ± 0.76° to 19.35° ± 3.43° and 19.03° ± 3.63° at 3 and 18 months (t = 12.517, 12.122, all p < 0.05). The ulnar variance decreased from 5.11 ± 0.23 mm to 1.32 ± 0.31 mm and 1.54 ± 0.62 mm at 3 and 18 months (t = 4.214, 4.895, all p < 0.05). The volar tilt was corrected from 4.47° ± 3.46° to 15.51° ± 2.72° and 14.12° ± 2.41°, respectively (t = 11.247, 10.432, all p < 0.05). Moreover, wrist ROM increased from 42.53° ± 8.99° to 98.70° ± 7.61° and 101.24° ± 7.66° (t = 41.433, 46.627, all p < 0.05), while forearm ROM was increased from 94.82° ± 6.54° to 134.47° ± 5.06° and 137.24° ± 5.52°, respectively (t = 31.507, 32.584, all p < 0.05). Similarly, grip strength, MMWS, and DASH were also remarkably improved. There were no significant differences in the wrist and forearm ROM, grip strength, MMWS, and DASH scores between follow-up at 3 and 18 months (all p > 0.05).

CONCLUSIONS

Corrective osteotomy with volar and dorsal fixation can improve recovery of volar tilt, relieve wrist pain, restore wrist and forearm function, and increase grip strength of patients with malunion of intra-articular fractures of the distal radius.

Corrective Osteotomy of Malunited Fractures of the Distal Radius Using a Combined Surgical Approach

Background: Malunited distal radius (DR) fractures following conservative treatment range from 6% to 80% of clinical observations. Surgical treatment is used to return the articular surface of the radius to original anatomical position and to restore the natural transfer of strength, wrist kinematics, and function of the entire hand. The aim of this research was to study and analyze the results of corrective osteotomy of malunited distal radius fractures using a combined approach. Methods: From 2008 to 2018, 43 patients with malunited DR fractures who underwent surgery using a combined approach were followed up. Long-term results (1 year after surgery) were studied in detail in 32 patients. Indications for surgery were determined taking into account, first, complaints of severe pain in the wrist during exertion, decreased hand strength, and limited mobility of the wrist. Results: Five patients (15.6%) reported a number of minor complications: intra-articular screw placement (2), incorrect reposition (1), transient neuropathy of the superficial branch of the radial nerve (1), and delayed fracture consolidation (1). In addition, another 5 patients reported the progression of wrist arthritis. Suppurations of the surgical wound and malunited fragments were not reported. Conclusions: During reconstructive interventions, a combined approach with palmar plating provides optimal conditions for corrective osteotomy, adequate reposition and plastic repair of the bone defect, and minimization of the number of complications.

Three-Dimensional Planning and Patient-Specific Instrumentation for the Fixation of Distal Radius Fractures

Background and Objectives: Three-dimensional planning and guided osteotomy utilizing patient-specific instrumentation (PSI) with the contralateral side used as a reference have been proven as effective in the treatment of malunions following complex fractures of the distal radius. However, this approach has not yet been described in relation to fracture reduction of the distal radius. The aim of this study was to assess the technical and logistical feasibility of computer-assisted surgery in a clinical setting using PSI for fracture reduction and fixation. Materials and Methods: Five patients with varied fracture patterns of the distal radius underwent operative treatment with using PSI. The first applied PSI guide allowed specific and accurate placement of Kirschner wires inside the multiple fragments, with subsequent concurrent reduction using a second guide. Results: Planning, printing of the guides, and operations were performed within 5.6 days on average (range of 1–10 days). All patients could be treated within a reasonable period of time, demonstrating good outcomes, and were able to return to work after a follow-up of three months. Mean wrist movements (°) were 58 (standard deviation (SD) 21) in flexion, 62 (SD 15) in extension, 73 (SD 4) in pronation and 74 (SD 10) in supination at a minimum follow-up of 6 months. Conclusions: Three-dimensional planned osteosynthesis using PSI for treatment of distal radius fractures is feasible and facilitates reduction of multiple fracture fragments. However, higher costs must be taken into consideration for this treatment.

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.

Bone healing of distal radius nonunion treated with bridge plating with bone graft substitutes in combination with systemic romosozumab administration: A case report

Romosozumab is a humanized, anti-sclerostin monoclonal antibody used to treat osteoporosis, which increases bone formation and decreases bone resorption. It enhances fracture healing and systemic romosozumab administration may have therapeutic potentials for accelerating bone healing of even nonunion. Herein, a 61-year-old heavy smoker male with distal radius nonunion who achieved successful bone union by combination therapy of romosozumab and spanning distraction plate fixation with bone graft substitutes was presented. Through the dorsal approach, atrophic comminuted nonunion of the distal radius was sufficiently debrided. Reduction of the distal radius was performed using indirect ligamentotaxis, and a 14-hole locking plate was fixed from the third metacarpal to the radial shaft. A beta (β) tricalcium phosphate block was mainly packed into the substantial metaphyseal bone defect with additional bone graft from the resected ulnar head. Postoperatively, systemic administration of monthly romosozumab was continued for six months. Complete bone union was achieved 20 weeks postoperatively and the plate was, then, removed. Wrist extension and flexion improved to 75o and 55o, respectively, without pain, and grip strength increased 52 weeks postoperatively from 5.5 kg to 22.4 kg. During romosozumab treatment, bone formation marker levels increased rapidly and finally returned to baseline, and bone resorption marker levels remained low. In conclusion, combination of systemic romosozumab administration and grafting β-tricalcium phosphate with bridge plating provides an effective treatment option for difficult cases of comminuted distal radius nonunion with risk factors such as smoking, diabetes, and fragility.

Inter-rater variability of three-dimensional fracture reduction planning according to the educational background

Background

Computer-assisted three-dimensional (3D) planning is increasingly delegated to biomedical engineers. So far, the described fracture reduction approaches rely strongly on the performance of the users. The goal of our study was to analyze the influence of the two different professional backgrounds (technical and medical) and skill levels regarding the reliability of the proposed planning method. Finally, a new fragment displacement measurement method was introduced due to the lack of consistent methods in the literature.

Methods

3D bone models of 20 distal radius fractures were presented to nine raters with different educational backgrounds (medical and technical) and various levels of experience in 3D operation planning (0 to 10 years) and clinical experience (1.5 to 24 years). Each rater was asked to perform the fracture reduction on 3D planning software.

Results

No difference was demonstrated in reduction accuracy regarding rotational (p = 1.000) and translational (p = 0.263) misalignment of the fragments between biomedical engineers and senior orthopedic residents. However, a significantly more accurate planning was performed in these two groups compared with junior orthopedic residents with less clinical experience and no 3D planning experience (p < 0.05).

Conclusion

Experience in 3D operation planning and clinical experience are relevant factors to plan an intra-articular fragment reduction of the distal radius. However, no difference was observed regarding the educational background (medical vs. technical) between biomedical engineers and senior orthopedic residents. Therefore, our results support the further development of computer-assisted surgery planning by biomedical engineers. Additionally, the introduced fragment displacement measure proves to be a feasible and reliable method.

Level of Evidence

Diagnostic Level II

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.

Understanding the Patterns of Deformity of Wrist Fractures Using Computer Analysis

Computer modeling of the wrist has followed other fields in the search for descriptive methods to understand the biomechanics of injury. Using patient-specific 3D computer models, we may better understand the biomechanics of wrist fractures in order to plan better care. We may better estimate fracture morphology and stability and evaluate surgical indications, design more adequate or effective surgical approaches and develop novel methods of therapy. The purpose of this review is to question the actual advances made in the understanding of wrist fractures using computer models.

Patient-Specific Three-Dimensional-printed Instrumentation for Radius Lengthening Osteotomy by a Volar Approach in Epiphysiodesis Sequelae: A Case Report

Introduction:

Patient-specific guides are used in the correction of malunion sequelae in adult distal radius fractures. They allow a tridimensional correction of radial glenoid orientation. However, lengthening is small in those indications. Distal radius epiphysiodesis correction is much rarer and patient-specific guide after three-dimensional (3D) planning has never been reported for this indication in the literature.

Case Report:

We report the case of a 16-year-old teenager with a chronic painful wrist and an ulnar positive variance after a post-traumatic epiphysiodesis sequela of the radius. The radius was 11mm shorter than the ulna. An anatomic reconstruction was decided with a lengthening of the radius. Pre-operative planning and patient-specific guide allowed to control an important radial lengthening, to limit the morbidity of the iliac crest bone graft harvesting, to shape the graft precisely, and to maintain a correct radial glenoid orientation despite the important soft tissue tension. Clinical and radiological results at 6 months showed a complete disappearance of pain, optimal objective and subjective functional scores, and an improvement in the distal ulnar variance (7mm). The teenager went back to sport without limitation or pain.

Conclusion:

3Dplanning and intraoperative patient-specific guides in radial epiphysiodesis sequelae allow achieving 3D accurate measures of the graft and of the deformation, guiding the position and the orientation of the distal metaphysis cut of the radius, and limiting the morbidity of the iliac graft harvesting. In that case, it allowed restoring the full function of the wrist without remaining pain.

Intra-articular corrective osteotomy for intra-articular malunion of distal radius fracture using three-dimensional surgical computer simulation and patient-matched instrument

BACKGROUND

Corrective osteotomy of malunited intra-articular distal radius fracture is challenging. In this study, we investigated the results in patients with malunited intra-articular distal radius fracture who underwent intra-articular corrective osteotomy through an extra-articular approach using three-dimensional (3-D) computer simulation and a patient-matched instrument (PMI).

METHODS

We retrospectively studied five consecutive patients with symptomatic malunited intra-articular distal radius fracture who underwent corrective osteotomy using a PMI. The maximal step-off on computed tomography and the deformity angle on plain radiographs were evaluated. The clinical examination parameters included range of motion (ROM), grip strength, pain according to visual analog scale (VAS), and Patient-Rated Wrist Evaluation (PRWE) score.

RESULTS

The maximal step-off was significantly reduced from 4.9 ± 1.8 to 1.0 ± 0.2 mm (p = 0.008). The absolute differences between the affected side and the normal contralateral side in radial inclination were significantly reduced from 5.4° ± 3.4°-1.2° ± 1.1° (p = 0.043). These differences were not significantly reduced postoperatively in the volar tilt and ulnar variance. VAS was significantly reduced from 4.1 ± 1.6 to 0.9 ± 0.7 cm (p = 0.006). The PRWE score significantly improved from 41.6 ± 22.0 to 15.7 ± 19.5 (p = 0.043). Grip strength was significantly increased from 54.0% ± 14.8%-85.8% ± 18.8% (p = 0.003). The preoperative and postoperative total arc of the wrist and forearm ROM were not significantly different.

CONCLUSIONS

Intra-articular corrective osteotomy using PMI could be one of the reliable treatment options for intra-articular malunion. PMI has exceptionally high precision performance, and it is also anticipated to yield superior surgical results.

Three-dimensional analysis of displacement characteristics of dorsally angulated intra-articular distal radial fractures

Understanding the complex fragmentation of intra-articular distal radial fractures contributes to achieving anatomical reduction during surgery. This study aimed to clarify three-dimensional displacement patterns of intra-articular fragmentation in dorsally angulated, intra-articular distal radial fractures. We identified five characteristic intra-articular fragments: a key fragment, dorsal ulnar corner, dorsal wall, radial column and anterior radial column. The key fragment was displaced with radial deviation, pronation and extension and with dorsal, proximal and radial translations. The dorsal ulnar corner displacement resulted in a gap, a step-off and a deepened concavity for the lunate facet and sigmoid notch. The dorsal wall displacement resulted in a deepened concavity, a gap and a step-off of the dorsal scaphoid facet. The displacements of the radial column and anterior radial column caused a step-off between the scaphoid and lunate facets. The five characteristic intra-articular fragments each created a characteristic gap and step-off in the articular surface. Level of evidence: IV.

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.

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.

Three-Dimensional In Vivo Analysis of Malunited Distal Radius Fractures With Restricted Forearm Rotation

Malunited distal radius fractures (DRFs) occasionally restrict forearm rotation, but the underlying pathology remains unclear. We aimed to elucidate the mechanism of rotational restriction by retrospective analysis of 23 patients with unilateral malunited DRFs who presented restricted forearm rotation. We conducted computed tomography during forearm rotation on both sides. Three-dimensional (3D) bone surface models of the forearm were created, and 3D deformity of the distal radius, translation of the distal radius relative to the ulna, distal radioulnar joint (DRUJ) contact area, and estimated path length (EPL) of distal radioulnar ligaments (DRUL) during forearm rotation were evaluated. In total, 18 patients had dorsal angular deformities (DA group) and five had volar angular deformities (VA group). In the DA group, the closest point between the distal radius and ulna on DRUJ was displaced to the volar side during supination and pronation (p < 0.001); DRUJ contact area was not significantly different between the DA and normal groups. In bone-ligament model simulation, the EPL of dorsal DRUL was longer in the DA group than in the normal group (p < 0.001); opposite phenomena were observed in the VA group. In the DA group, translation of the distal radius in a volar direction relative to the ulna during pronation was impaired presumably due to dorsal DRUL tightness. Anatomical normal reduction of the distal radius by corrective osteotomy may improve forearm rotation by improving triangular fibrocartilage complex tightness and normalizing translation of the distal radius relative to the ulna. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1881-1891, 2019.

Open Wedge Osteotomy with Ulnar Shortening for Madelung Deformity Using a Computer-Generated Template

A variety of osteotomies have been reported to correct Madelung deformity using plain radiographs. However, evaluation of the deformity using 2-dimensional plain radiography is difficult because of its complex 3-dimensional nature. Therefore, we performed corrective osteotomy using recently developed 3D simulation technology on an adult woman with Madelung deformity, and achieved an excellent outcome. In this study, we calculated the amount of parallel displacement as well as the rotational angle for more precise correction, and performed open wedge osteotomy. Furthermore, we performed concurrent ulnar shortening. An exaggerated radial inclination was observed in the posteroanterior radiograph. A palmar shift of the carpus and dorsal dislocation of the ulnar head were observed in the lateral radiograph. In the preoperative findings, radial inclination (RI), volar tilt (VT), and ulnar variance (UV) were 35°, 40°, and 12 mm, respectively. The wrist showed improvement, with an RI of 25°, VT of 14°, and UV of 0 mm. At present, 14 months after surgery, there has been no loss of correction, instability of the ulnar head, or pain on the ulnar side. The procedure resulted in improvements in the protrusion and pain in the ulnar portion of the patient's wrist. Based on this result, we believe that accurate corrective osteotomy with ulnar shortening should be performed for Madelung deformity.

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.

Implementation of a semiautomatic method to design patient-specific instruments for corrective osteotomy of the radius

PURPOSE

3D-printed patient-specific instruments (PSIs), such as surgical guides and implants, show great promise for accurate navigation in surgical correction of post-traumatic deformities of the distal radius. However, existing costs of computer-aided design and manufacturing process prevent everyday surgical use. In this paper, we propose an innovative semiautomatic methodology to streamline the PSIs design.

METHODS

The new method was implemented as an extension of our existing 3D planning software. It facilitates the design of a regular and smooth implant and a companion guide starting from a user-selected surface on the affected bone. We evaluated the software by designing PSIs starting from preoperative virtual 3D plans of five patients previously treated at our institute for corrective osteotomy. We repeated the design for the same cases also with commercially available software, with and without dedicated customization. We measured design time and tracked user activity during the design process of implants, guides and subsequent modifications.

RESULTS

All the designed shapes were considered valid. Median design times ([Formula: see text]) were reduced for implants (([Formula: see text]) = 2.2 min) and guides (([Formula: see text]) = 1.0 min) compared to the standard (([Formula: see text]) = 13 min and ([Formula: see text]) = 8 min) and the partially customized (([Formula: see text]) = 6.5 min and ([Formula: see text]) = 6.0 min) commercially available alternatives. Mouse and keyboard activities were reduced (median count of strokes and clicks during implant design (([Formula: see text]) = 53, and guide design (([Formula: see text]) = 27) compared to using standard software (([Formula: see text]) = 559 and ([Formula: see text]) = 380) and customized commercial software (([Formula: see text]) = 217 and ([Formula: see text]) = 180).

CONCLUSION

Our software solution efficiently streamlines the design of PSIs for distal radius malunion. It represents a first step in making 3D-printed PSIs technology more accessible.

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.

Morphology and kinematics studies of the upper extremity and its clinical application in deformity correction

Morphological and kinetic studies using computer-generated bone models are helpful for determining normal articular movements and various pathological conditions of the wrist joints, forearms, and elbow joints. Previous studies consisted of kinetic analyses that were carried out by superimposing three-dimensional bone models created on a computer on the basis of CT data obtained by scanning the limbs in several different positions. We applied the techniques used in such studies and have discovered a method for carrying out surgical procedure simulations aimed at correcting upper limb deformities. In addition, we have developed a system aimed at assisting surgical procedures conducted in accordance with simulations by using patient-matched guides (patient-matched instruments, PMI) and custom-made osteosynthesis plates. Our system has allowed for accurate anatomical corrections to be carried out three-dimensionally during a simple surgical procedure. The system was clinically used in the treatment of cubitus varus as well as malunited distal radial fractures and forearm fractures. As a result, accurate correction and favorable clinical outcomes have been achieved. Together with the development of therapeutic techniques, we have also simultaneously developed the related technological system, which consists of imaging protocols aimed at reducing the amount of radiation exposure and creating statistical shape models, as well as web-based tools for communication between physicians and engineers.

Corrective osteotomy of distal radius malunions using three-dimensional computer simulation and patient-specific guides to achieve anatomic reduction

Malunion is a common complication of distal radius fractures, especially those treated conservatively. In clinical studies, a significant correlation between anatomic reduction and wrist function has been shown. Corrective osteotomy is the preferred treatment for symptomatic cases, notwithstanding the technical challenges. The use of computer simulation improves pre-operative understanding of the three-dimensional deformity. Patient-specific surgical guides, based on precise pre-operative planning, lead to superior perioperative accuracy and reproducibility. The pre-operative planning and surgical technique of distal radius corrective surgery using three-dimensional computer technology are described in detail. The preliminary results demonstrate the excellent clinical and radiographic outcome of this technique.

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.

A novel surgical approach for treating distal radial extraarticular malunion: Oblique osteotomy with buttress plate stabilization

PURPOSE

Distal radial extraarticular malunions are not uncommon. However, requirements of surgical correction depend on multiple conditions. Traditionally, surgical techniques include closing or opening wedge osteotomies. Each has unique advantages and disadvantages. An oblique osteotomy was developed to simplify the revision surgery.

METHODS

Forty-eight consecutive adult patients with 48 malunions were surgically treated. An oblique osteotomy of 45° vertical to the radial longitudinal axis was performed from medio-distally to latero-proximally. Consequently, the osteotomized fragments were compressed with a bone clamp. The proximal part of the distal fragment was pushed backward to correct the dorsal tilt. A 7-hole buttress plate was inserted volarly and cancellous bone graft was packed. Postoperatively, a short-arm splint or brace without restriction of all five metacarpophalangeal joints was applied for 6 weeks.

RESULTS

Forty-one patients were followed for an average of 2.8 years (range, 1.1-5.8 years). All malunions healed within 6 weeks. The union rate was 100% and no complications occurred. Radiographically, ulnar variance, volar tilt of radial articulation, and radial inclination restored to acceptable criteria in all patients. Patients with Modified Mayo Wrist Score (MMWS) improved from 17% to 80% ( p < 0.001) and Disability of Arm, Shoulder and Hand (DASH) Score improved from 0% to 80% ( p < 0.001). The relationship between MMWS and DASH Score was highly correlated (correlation coefficient = -0.90).

CONCLUSION

The described approach may be an excellent alternative for treating distal radial extraarticular malunions. The technique is not difficult but the satisfactory rate is high.

Corticocancellous bone graft vs cancellous bone graft for the management of unstable scaphoid nonunion

INTRODUCTION

This study was undertaken to determine whether corticocancellous bone grafting and cancellous bone grafting differ in terms of bone union rate, restoration of scaphoid anatomy, and wrist function when unstable scaphoid nonunions are concomitantly treated by screw fixation.

MATERIALS AND METHODS

This is retrospective cohort study. In Group A (17 patients), unstable scaphoid nonunion was treated with corticocancellous graft harvested from the iliac crest and headless compression screw using volar approach. In Group B (18 patients), unstable scaphoid nonunion was treated with cancellous graft harvested from the distal radius or iliac crest and headless compression screw using volar approach Mean time to union was measured using CT image. Scaphoid deformity was also measured using lateral intrascaphoid angle and height to length ratio using CT images. Wrist functional status was assessed by measuring grip strength, wrist range of motion, and DASH score at 1 year postoperatively.

RESULTS

Mean time to union was significantly greater in Group A (15 weeks vs. 11 weeks). No significant intergroup difference was observed for lateral intrascaphoid angle and height to length ratio after treatment of scaphoid nonunion. No significant intergroup difference was observed for grip strength, wrist range of motion, or DASH scores at 1 year postoperatively.

CONCLUSIONS

Cancellous bone grafting was found to lead to earlier bone union than corticocancellous bone grafting and to similar restorations of scaphoid deformity and wrist function when scaphoid nonunion was treated by headless compression screw fixation and bone grafting.

LEVEL OF EVIDENCE

Prognostic, III.

Physeal bar resection using a patient-specific guide with intramedullary endoscopic assistance for partial physeal arrest of the distal radius

The partial physeal arrest of the distal radius could result in progressive deformities and functional problems of the wrist. Despite being the most preferred surgical intervention, physeal bar resection (Langenskiöld procedure) is technically demanding. This manuscript aims to illustrate the technical tricks and present an illustrative case of premature physeal arrest of the distal radius managed with a novel method for the Langenskiöld procedure, involving complete removal of the bar using a patient-specific guide in combination with an intramedullary endoscopy technique that facilitated direct observation.

Positioning error of custom 3D-printed surgical guides for the radius: influence of fitting location and guide design

PURPOSE

Utilization of 3D-printed patient-specific surgical guides is a promising navigation approach for orthopedic surgery. However, navigation errors can arise if the guide is not correctly positioned at the planned bone location, compromising the surgical outcome. Quantitative measurements of guide positioning errors are rarely reported and have never been related to guide design and underlying bone anatomy. In this study, the positioning accuracy of a standard and an extended guide design with lateral extension is evaluated at different fitting locations (distal, mid-shaft and proximal) on the volar side of the radius.

METHODS

Four operators placed the surgical guides on 3D-printed radius models obtained from the CT scans of six patients. For each radius model, every operator positioned two guide designs on the three fitting locations. The residual positioning error was quantified with a CT-based image analysis method in terms of the mean target registration error (mTRE), total translation error ([Formula: see text]) and total rotation error ([Formula: see text]) by comparing the actual guide position with the preoperatively planned position. Three generalized linear regression models were constructed to evaluate if the fitting location and the guide design affected mTRE, [Formula: see text] and [Formula: see text].

RESULTS

mTRE, [Formula: see text] and [Formula: see text] were significantly higher for mid-shaft guides ([Formula: see text]) compared to distal guides. The guide extension significantly improved the target registration and translational accuracy in all the volar radius locations ([Formula: see text]). However, in the mid-shaft region, the guide extension yielded an increased total rotational error ([Formula: see text]).

CONCLUSION

Our study demonstrates that positioning accuracy depends on the fitting location and on the guide design. In distal and proximal radial regions, the accuracy of guides with lateral extension is higher than standard guides and is therefore recommended for future use.

Computer-assisted planning and patient-specific guides for the treatment of midshaft clavicle malunions

BACKGROUND

The surgical treatment of malunions after midshaft clavicle fractures is associated with a number of potential complications and the surgical procedure is challenging. However, with appropriate and meticulous preoperative surgical planning, the surgical correction yields satisfactory results. The purpose of this study was to provide a guideline and detailed overview for the computer-assisted planning and 3-dimensional (3D) correction of malunions of the clavicle.

METHODS

The 3D bone surface models of the pathologic and contralateral sides were created on the basis of computed tomography data. The computer-assisted assessment of the deformity, the preoperative plan, and the design of patient-specific guides enabling compression plating are described.

RESULTS

We demonstrate the benefit and versatility of computer-assisted planning for corrective osteotomies of malunions of the midshaft clavicle. In combination with patient-specific guides and compression plating technique, the correction can be performed in a more standardized fashion. We describe the determination of the contact-optimized osteotomy plane. An osteotomy along this plane facilitates the correction and enlarges the contact between the fragments at once. We further developed a technique of a stepped osteotomy that is based on the calculation of the contact-optimized osteotomy plane. The stepped osteotomy enables the length to be restored without the need of structural bone graft. The application of the stepped osteotomy is presented for malunions of the clavicle with shortening and excessive callus formation.

CONCLUSIONS

The 3D preoperative planning and patient-specific guides for corrective osteotomies of the clavicle may help reduce the number of potential complications and yield results that are more predictable.

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.

Bilateral shoulder arthrodesis in a Pekinese using three-dimensional printed patient-specific osteotomy and reduction guides

OBJECTIVE

To report the use of computer-aided design software for virtual surgical planning and design of three-dimensional printed patient-specific osteotomy and reduction guides for facilitation of bilateral shoulder arthrodesis in a dog.

METHODS

A three-year-old male entire Pekinese was presented unable to walk due to bilateral severe medial shoulder instability. Computed tomographic data was processed to yield three-dimensional mesh representations of the humeri and scapulae which could be manipulated in computer-aided design software. Key virtual surgical planning steps included joint realignment, osteotomies of the glenoid and humeral head, and reduction. Virtual osteotomy and reduction guides were designed, three-dimensionally printed, and used intra-operatively.

RESULTS

Appropriate alignment, reduction and fixation of the humeri and scapulae were achieved bilaterally. The patient regained the ability to walk unassisted after two weeks and was subsequently able to exercise normally without lameness.

CLINICAL SIGNIFICANCE

Patient-specific, three-dimensional printed osteotomy and reduction guides facilitated accurate bilateral shoulder arthrodeses.

A Graphic Overlay Method for Selection of Osteotomy Site in Chronic Radial Head Dislocation: An Evaluation of 3D-printed Bone Models

PURPOSE

Three-dimensional (3D) computed tomography imaging is now being used to generate 3D models for planning orthopaedic surgery, but the process remains time consuming and expensive. For chronic radial head dislocation, we have designed a graphic overlay approach that employs selected 3D computer images and widely available software to simplify the process of osteotomy site selection.

METHODS

We studied 5 patients (2 traumatic and 3 congenital) with unilateral radial head dislocation. These patients were treated with surgery based on traditional radiographs, but they also had full sets of 3D CT imaging done both before and after their surgery: these 3D CT images form the basis for this study. From the 3D CT images, each patient generated 3 sets of 3D-printed bone models: 2 copies of the preoperative condition, and 1 copy of the postoperative condition. One set of the preoperative models was then actually osteotomized and fixed in the manner suggested by our graphic technique. Arcs of rotation of the 3 sets of 3D-printed bone models were then compared.

RESULTS

Arcs of rotation of the 3 groups of bone models were significantly different, with the models osteotomized accordingly to our graphic technique having the widest arcs.

CONCLUSIONS

For chronic radial head dislocation, our graphic overlay approach simplifies the selection of the osteotomy site(s). Three-dimensional-printed bone models suggest that this approach could improve range of motion of the forearm in actual surgical practice.

LEVEL OF EVIDENCE

Level IV-therapeutic study.

Putting 3D modelling and 3D printing into practice: virtual surgery and preoperative planning to reconstruct complex post-traumatic skeletal deformities and defects

3D printing technology has revolutionized and gradually transformed manufacturing across a broad spectrum of industries, including healthcare. Nowhere is this more apparent than in orthopaedics with many surgeons already incorporating aspects of 3D modelling and virtual procedures into their routine clinical practice. As a more extreme application, patient-specific 3D printed titanium truss cages represent a novel approach for managing the challenge of segmental bone defects. This review illustrates the potential indications of this innovative technique using 3D printed titanium truss cages in conjunction with the Masquelet technique. These implants are custom designed during a virtual surgical planning session with the combined input of an orthopaedic surgeon, an orthopaedic engineering professional and a biomedical design engineer. The ability to 3D model an identical replica of the original intact bone in a virtual procedure is of vital importance when attempting to precisely reconstruct normal anatomy during the actual procedure. Additionally, other important factors must be considered during the planning procedure, such as the three-dimensional configuration of the implant. Meticulous design is necessary to allow for successful implantation through the planned surgical exposure, while being aware of the constraints imposed by local anatomy and prior implants. This review will attempt to synthesize the current state of the art as well as discuss our personal experience using this promising technique. It will address implant design considerations including the mechanical, anatomical and functional aspects unique to each case.

Prediction of forearm bone shape based on partial least squares regression from partial shape

BACKGROUND

Computer-assisted corrective osteotomy using a mirror image of the normal contralateral shape as reference is increasingly used. Instead, we propose to use the shape predicted by statistical learning to deal with cases demonstrating bilateral abnormality, such as bilateral trauma, congenital disease, and metabolic disease.

METHODS

Computed tomography (CT) scans of 100 normal forearms were used in this study. The whole bone shape was predicted from its partial shape based on statistical learning of the other 99 bones. Accuracy was evaluated by average symmetric surface distance (ASD), and translational and rotational errors.

RESULTS

ASDs for predicted shapes were 0.71-1.03 mm. Mean absolute translational and rotational errors were 0.48-1.76 mm and 0.99-6.08°, respectively.

CONCLUSION

Normal bone shape was predicted with an acceptable accuracy from its partial shape using statistical learning. Predicted shape can be an alternative to a mirror image, which may enable reduced radiation exposure and examination costs.

Three-dimensional corrective osteotomies of complex malunited humeral fractures using patient-specific guides

BACKGROUND

Corrective osteotomies of malunited fractures of the proximal and distal humerus are among the most demanding orthopedic procedures. Whereas the restoration of the normal humeral anatomy is the ultimate goal, the quantification of the deformity as well as the transfer of the preoperative plan is challenging. The purpose of this study was to provide a guideline for 3-dimensional (3D) corrective osteotomies of malunited intra-articular fractures of the humerus and a detailed overview of existing and novel instruments to enlarge the toolkit for 3D preoperative planning and intraoperative realization using patient-specific guides.

METHODS

We describe the preoperative 3D deformity analysis, relevant considerations for the preoperative plan, design of the patient-specific guides, and surgical technique of corrective osteotomies of the humerus.

RESULTS

The presented technique demonstrates the benefit of computer-assisted surgery for complex osteotomies of the humerus from a preoperative deformity analysis to the creation of feasible surgical procedures and the generation of patient-specific guides.

CONCLUSIONS

A 3D analysis of a post-traumatic deformity of the humerus, 3D preoperative planning, and use of patient-specific guides facilitate corrective osteotomies of complex malunited humeral fractures.