Computer-assisted corrective osteotomy for malunited diaphyseal forearm fractures

Near-anatomical correction using a CT-guided technique of a forearm malunion in a 15-year-old girl: A case report including surgical technique

BACKGROUND

In this case report, we describe a left-arm both-bone forearm fracture in a 15-year-old girl who fell off a swing. Conservative treatment with an above-elbow cast failed, resulting in a malunion with functional impairment. The pro- and supination were 90/0/10, respectively. The patient complained of difficulties performing daily activities. For this pediatric case, a corrective osteotomy was proposed using a CT-guided technique aiming for maximum anatomical and functional outcome. It was the first time this technique was used in our hospital.

METHODS

A corrective osteotomy of the patient's left arm was performed using 3D printed templates to guide the osteotomy orientation. These templates were produced using specialized software in which CT images of her malunited left forearm were overlaid with the mirrored images of her healthy right forearm.

RESULTS

The postoperative CT-scan showed a near-anatomical reduction with close to 1° correction in all three planes, as compared to the preoperative planning. Three months after surgery, the patient had regained full function of her left forearm.

CONCLUSION

Although this was the first time this technique was used in our hospital, it resulted in excellent anatomical and functional outcomes making it a safe, reliable and precise treatment option that may be useful for even more complex corrections.

LEVEL OF EVIDENCE

Level V.

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

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

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.

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.

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.

Rapid prototyping for patient-specific surgical orthopaedics guides: A systematic literature review

There has been a lot of hype surrounding the advantages to be gained from rapid prototyping processes in a number of fields, including medicine. Our literature review aims objectively to assess how effective patient-specific surgical guides manufactured using rapid prototyping are in a number of orthopaedic surgical applications. To this end, we carried out a systematic review to identify and analyse clinical and experimental literature studies in which rapid prototyping patient-specific surgical guides are used, focusing especially on those that entail quantifiable outcomes and, at the same time, providing details on the guides’ design and type of manufacturing process. Here, it should be mentioned that in this field there are not yet medium- or long-term data, and no information on revisions. In the reviewed studies, the reported positive opinions on the use of rapid prototyping patient-specific surgical guides relate to the following main advantages: reduction in operating times, low costs and improvements in the accuracy of surgical interventions thanks to guides’ personalisation. However, disadvantages and sources of errors which can cause patient-specific surgical guide failures are as well discussed by authors. Stereolithography is the main rapid prototyping process employed in these applications although fused deposition modelling or selective laser sintering processes can also satisfy the requirements of these applications in terms of material properties, manufacturing accuracy and construction time. Another of our findings was that individualised drill guides for spinal surgery are currently the favourite candidates for manufacture using rapid prototyping. Other emerging applications relate to complex orthopaedic surgery of the extremities: the forearm and foot. Several procedures such as osteotomies for radius malunions or tarsal coalition could become standard, thanks to the significant assistance provided by rapid prototyping patient-specific surgical guides in planning and performing such operations.

Three-dimensional printing in orthopaedic surgery: review of current and future applications

Three-dimensional (3D) printing is a rapidly evolving technology with the potential for significant contributions to surgical practice. There are many current applications for 3D printing technology with future applications being explored. This technology has applications in preoperative planning, education, custom manufacturing (implants, prosthetics and surgical guides) and exciting potential for biological applications. This article reviews the current and future applications of 3D technology in orthopaedic surgery.

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.

Complex forearm deformities: operative strategy in posttraumatic pathology

Complex posttraumatic forearm deformities have a significant impact on the integrity of the upper extremity leading to pain, instability in both the proximal and/or distal radioulnar articulation, and reduced range of forearm motion. Corrective osteotomy or more advanced procedures for malunited fractures or other posttraumatic deformities of the upper extremity, especially in the forearm are challenging procedures. In this review we will discuss the essential aspects of anatomy and pathomechanics, clinical and radiological assessment and the pathway from preoperative planning to the actual deformity correction surgery, either with one-stage correction or using gradual lengthening with external fixation (“callotasis techniques”) and finally the functional outcome we can expect for our patients. In addition we will analyze the modern computer-assisted techniques available to date.

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.

Three-Dimensional Assessment of Bilateral Symmetry of the Scaphoid: An Anatomic Study

Preoperative 3D CT imaging techniques provide displacement analysis of the distal scaphoid fragment in 3D space, using the matched opposite scaphoid as reference. Its accuracy depends on the presence of anatomical bilateral symmetry, which has not been investigated yet using similar techniques. Our purpose was to investigate symmetry by comparing the relative positions of distal and proximal poles between sides. We used bilateral CT scans of 19 adult healthy volunteers to obtain 3D scaphoid models. Left proximal and distal poles were matched to corresponding mirrored right sides. The left-to-right positional differences between poles were quantified in terms of three translational and three rotational parameters. The mean (SD) of ulnar, dorsal, and distal translational differences of distal poles relative to proximal poles was 0.1 (0.6); 0.4 (1.2); 0.2 (0.6) mm and that of palmar rotation, ulnar deviation, and pronation differences was −1.1 (4.9); −1.5 (3.3); 1.0 (3.7)°, respectively. These differences did not significantly differ from zero and thus were not biased to left or right side. We proved that, on average, the articular surfaces of scaphoid poles were symmetrically aligned in 3D space. This suggests that the contralateral scaphoid can serve as reference in corrective surgery. No level of evidence is available.

Complex Osteotomies of Tibial Plateau Malunions Using Computer-Assisted Planning and Patient-Specific Surgical Guides

The accurate reduction of tibial plateau malunions can be challenging without guidance. In this work, we report on a novel technique that combines 3-dimensional computer-assisted planning with patient-specific surgical guides for improving reliability and accuracy of complex intraarticular corrective osteotomies. Preoperative planning based on 3-dimensional bone models was performed to simulate fragment mobilization and reduction in 3 cases. Surgical implementation of the preoperative plan using patient-specific cutting and reduction guides was evaluated; benefits and limitations of the approach were identified and discussed. The preliminary results are encouraging and show that complex, intraarticular corrective osteotomies can be accurately performed with this technique. For selective patients with complex malunions around the tibia plateau, this method might be an attractive option, with the potential to facilitate achieving the most accurate correction possible.

The use of computer-aided design and 3-dimensional models in the treatment of forearm malunions in children

Computer-aided design has several orthopedic applications. In this article we propose the use of computer-aided design to address the problem of forearm malunions in children. Traditional methods of planning forearm osteotomies utilize 2-dimensional radiographs, however, this is not a reliable method to address rotational deformities. Our method involves collaboration with clinical engineers at Materialise (Leuven, Belgium) to produce patient-specific cutting jigs using preoperative computed tomographic scans and 3-dimensional printing technology. This method allows for precise planning of complex and multiple osteotomies while decreasing the need for intraoperative decision making. Our initial results with this technique demonstrate improvements in forearm rotation and distal radioulnar joint stability.

Postoperative accuracy analysis of three-dimensional corrective osteotomy for cubitus varus deformity with a custom-made surgical guide based on computer simulation

BACKGROUND

For correction of cubitus varus deformity resulting from supracondylar fracture of the humerus, we developed an operative method with use of a custom-made surgical guide, designed on the basis of 3-dimensional (3D) computer simulation with computed tomography data. The purpose of this study was to investigate the postoperative accuracy of this system in clinical cases.

METHODS

Subjects included 17 consecutive patients (13 males and 4 females) with cubitus varus deformity after supracondylar fracture. Patients underwent 3D corrective osteotomy with use of a custom-made surgical guide. Postoperative computed tomography scan was performed after bone union diagnosis on plain radiographs, and postoperative 3D bone models were compared with preoperative simulation by surface registration technique. In addition, we evaluated radiographic parameters (humerus-elbow-wrist angle and tilting angle) and range of elbow motion at the most recent follow-up.

RESULTS

Mean errors in 3D corrective osteotomy were 0.6° ± 0.7° in varus-valgus rotation, 0.8° ± 1.3° in flexion-extension rotation, 2.9° ± 2.8° in internal-external rotation, 1.7 ± 1.8 mm in anterior-posterior translation, 1.3 ± 1.8 mm in lateral-medial translation, and 7.1 ± 6.3 mm in proximal-distal translation. The mean humerus-elbow-wrist angle on plain radiographs of the affected side was 15° in varus before surgery and improved to 6° in valgus after surgery. The mean tilting angle of the affected side was 31° before surgery and improved to 40° after surgery.

CONCLUSION

The 3D correction of cubitus varus deformity was performed accurately within the allowable error limits.

Reconstruction of malunited diaphyseal fractures of the forearm

The forearm is a complex anatomical and functional unit with unique osseous, soft tissue and articular relationships. Disruption of these important relations can have a significant impact, leading to pain, instability of the radio-ulnar articulation and reduced range of motion. The gold standard for treating forearm fractures in adults remains anatomic reduction, stable plate fixation and preservation of the surrounding blood supply. Failure to achieve these goals may lead to malunion, requiring reconstructive surgery, which can be technically challenging. In this review, we discuss the essential aspects of anatomy and pathomechanics, clinical and radiological assessment and the state of the art in pre-operative planning and deformity correction surgery.

Comparison of acetabular shell position using patient specific instruments vs. standard surgical instruments: a randomized clinical trial

Total hip arthroplasty (THA) survivorship relies largely upon appropriate acetabular cup placement. The purpose of this prospective randomized controlled trial was to determine whether the use of a preoperative 3D planning software in combination with patient specific instrumentation (PSI) results in improved cup placement compared with traditional techniques. Thirty-six THA patients were randomized into standard (STD) or PSI technique. Standard approach was completed using traditional techniques, while PSI cases were planned and customized surgical instruments were manufactured. Postoperative CT scans were used to compare planned to actual results. Differences found between planned and actual anteversion were -0.2° ± 6.9° (PSI) and -6.9°±8.9° (STD) (P = 0.018). Use of 3D preoperative planning along with PSIs resulted in significantly greater anteversion accuracy than traditional planning and instrumentation.

Three-Dimensional Corrective Osteotomy for Cubitus Varus Deformity with Use of Custom-Made Surgical Guides

Introduction

We present a detailed description of our preoperative planning and surgical technique for three-dimensional (3-D) corrective osteotomy with use of custom-made surgical guides for cubitus varus deformity after supracondylar fracture.

Step 1 Create Computer Bone Models from CT Data

Obtain CT data of both upper extremities and create computer bone models from these data.

Step 2 Evaluate the 3-D Deformity

Evaluate the deformity in three dimensions by comparing the affected humerus with the mirror image of the contralateral, normal humerus.

Step 3 Plan the 3-D Corrective Osteotomy

Simulate a 3-D corrective osteotomy on the basis of information obtained from the deformity evaluation.

Step 4 Operative Setup

Order the custom-made surgical guides that will assist you in reproducing the preoperative simulation during the actual surgery.

Step 5 Perform the 3-D Osteotomy Using the Custom-Made Surgical Guides

Perform the osteotomy using the custom-made surgical guides and achieve anatomical correction using the reduction guides.

Step 6 Postoperative Care

Apply a removable splint and have the patient start active and passive range-of-motion exercise after the splinting period has been completed.

Results

In our series of thirty patients, the mean humerus-elbow-wrist angle and tilting angle of the affected side were 18° (varus) and 25°, respectively, before surgery, which significantly improved to 6° (valgus) and 38°, respectively, after surgery.IndicationsContraindicationsPitfalls & Challenges.

Radial head dislocation during proximal radial shaft osteotomy

The following case report describes a 48-year-old female patient with a longstanding both-bone forearm malunion, who underwent osteotomies of both the radius and ulna to improve symptoms of pain and lack of rotation at the wrist. The osteotomies were templated preoperatively. During surgery, after performing the planned radial shaft osteotomy, the authors recognized that the radial head was subluxated. The osteotomy was then revised from an opening wedge to a closing wedge with improvement of alignment and rotation. The case report discusses the details of the operation, as well as ways in which to avoid similar shortcomings in the future.

Cylindrical corrective osteotomy for Madelung deformity using a computer simulation: case report

We report an adolescent patient with Madelung deformity that we successfully treated by cylindrical corrective osteotomy of the distal radius. We used customized surgical guides, which were designed based on preoperative 3-dimensional computer simulation.

Three-dimensional corrective osteotomy using a patient-specific osteotomy guide and bone plate based on a computer simulation system: accuracy analysis in a cadaver study

BACKGROUND

The accuracy of three-dimensional (3-D) corrective osteotomy using a patient-specific osteotomy guide and bone plate based on computer simulation was investigated.

METHODS

Six fresh-frozen cadaver upper limbs were used. A patient-specific osteotomy guide designed to realize a preplanned osteotomy was set on the distal humerus and distal radius, and the error in the setting location was evaluated. After the osteotomy, the surgical site was fixed using a patient-specific bone plate designed to exactly fit the anatomical shape of the postoperative bone model. The postoperative results were compared with the preoperative simulation.

RESULTS

The errors in the guide location on the humerus and radius were <1.5° and 1.0 mm and <1.0° and 1.0 mm, respectively. The plate fixation errors of the humerus and radius were <2.0° and 1.5 mm and <1.0° and 1.0 mm, respectively.

CONCLUSIONS

The system is sufficiently feasible to realize precise 3-D deformity correction of a limb.

Three-Dimensional Corrective Osteotomy for Malunited Diaphyseal Forearm Fractures Using Custom-Made Surgical Guides Based on Computer Simulation

Introduction

Three-dimensional corrective osteotomy with use of custom-made surgical guides based on computer simulation can provide a good outcome for patients with a malunited diaphyseal forearm fracture.

Step 1 Create Computer Bone Models from CT Data

Obtain CT data of both forearms, and create computer models of the bones from CT data.

Step 2 Evaluate 3D Deformity

Evaluate the 3D deformity by comparing the affected bone with the mirror image of the contralateral, normal bone.

Step 3 Plan 3D Corrective Osteotomy

Simulate the 3D corrective osteotomy on the basis of information obtained from the deformity evaluation.

Step 4 Design Custom-Made Surgical Guides

Design custom-made surgical guides to reproduce the preoperative simulation during the actual surgery.

Step 5 Operative Setup

Manufacture custom-made surgical guides to reproduce the preoperative simulation during the actual surgery.

Step 6 Perform 3D Osteotomy Using Custom-Made Osteotomy Guides

Perform the osteotomy using the custom-made osteotomy guides and achieve anatomical correction using the reduction guides.

Results

In our series of twenty patients, the average radiographic deformity angle preoperatively was 21° (range, 12° to 35°) compared with that of the normal arm; this improved to 1° (range, 0° to 4°) postoperatively.

What to Watch For

IndicationsContraindicationsPitfalls & Challenges.