Computer aided surgery in foot and ankle: applications and perspectives

Robotic-assisted foot and ankle surgery: a review of the present status and the future

The surgical application of robotics has increased significantly since its first application in 1985 for a brain biopsy acquisition. Robotic-assisted surgery has been one of the viable options in various surgical areas, and also in orthopaedic surgery. Robotic-assisted orthopaedic surgery has gained popularity as a mean of improving accuracy, reducing complications and achieving better patient satisfaction. Numerous clinical research studies have demonstrated advantages of robotic-assisted orthopaedic surgery, however, most of that researches were about the total knee arthroplasty, total hip arthroplasty and spine surgery. The application of robotic technology in foot and ankle surgery is in a very nascent stage. Furthermore, there has been little research on intraoperative use of robotics in foot and ankle surgery in literature. A review of previous preclinical studies in foot and ankle robotics and clinical research studies in various fields of robot-assisted orthopaedic surgery shows that its potential application and benefits over conventional techniques, such as total ankle arthroplasty, minimally invasive surgery for foot and ankle trauma or other corrective procedure, and intraoperative biomechanical testing. More studies on practical application of robotic technology to surgical procedure in the field of foot and ankle surgery are needed to confirm its clinical usefulness and cost effectiveness.

Robotic Technology in Foot and Ankle Surgery: A Comprehensive Review

Recent developments in robotic technologies in the field of orthopaedic surgery have largely been focused on higher volume arthroplasty procedures, with a paucity of attention paid to robotic potential for foot and ankle surgery. The aim of this paper is to summarize past and present developments foot and ankle robotics and describe outcomes associated with these interventions, with specific emphasis on the following topics: translational and preclinical utilization of robotics, deep learning and artificial intelligence modeling in foot and ankle, current applications for robotics in foot and ankle surgery, and therapeutic and orthotic-related utilizations of robotics related to the foot and ankle. Herein, we describe numerous recent robotic advancements across foot and ankle surgery, geared towards optimizing intra-operative performance, improving detection of foot and ankle pathology, understanding ankle kinematics, and rehabilitating post-surgically. Future research should work to incorporate robotics specifically into surgical procedures as other specialties within orthopaedics have done, and to further individualize machinery to patients, with the ultimate goal to improve perioperative and post-operative outcomes.

The Assessment of Ankle Osteoarthritis with Weight-Bearing Computed Tomography

The standard for diagnostic radiographic imaging in foot and ankle surgery was until 2012 radiographs with full weight-bearing without any useful alternative. Weight-bearing cone-beam computed tomography (WBCT) was introduced 2012 for foot and ankle use as a new technology that allows 3D imaging with full weight-bearing which should be not influenced by projection and/or foot orientation. The assessment of ankle osteoarthritis with WBCT including the description of healthy status, effect of alignment and7or (in)stability is extensively illustrated in this review article.

Preoperative Guidance With Weight-Bearing Computed Tomography and Patient-Specific Instrumentation in Foot and Ankle Surgery

The use of preoperative and intraoperative guidance in foot and ankle surgery has grown substantially in recent years. Weight-bearing computed tomography (WBCT) and patient-specific instrumentation (PSI) are used in total ankle arthroplasty (TAA) to achieve precise bone cutting and implant positioning, and intraoperative 3-dimensional (3D) imaging has been used to reduce complications and improve clinical outcomes in other foot and ankle surgical procedures. This narrative review of the literature focuses on the evidence supporting the use of WBCT and PSI in TAA and looks at other promising technologies used to guide foot and ankle surgery.

Computer-assisted surgery and navigation in foot and ankle: state of the art and fields of application

Computer-assisted orthopaedic surgery (CAOS) is a real-time navigation guidance system that supports surgeons intraoperatively.Its use is reported to increase precision and facilitate less-invasive surgery.Advanced intraoperative imaging helps confirm that the initial aim of surgery has been achieved and allows for immediate adjustment when required.The complex anatomy of the foot and ankle, and the associated wide range of challenging procedures should benefit from the use of CAOS; however, reports on the topic are scarce.This article explores the fields of applications of real-time navigation and CAOS in foot and ankle surgery. Cite this article: EFORT Open Rev 2021;6:531-538. DOI: 10.1302/2058-5241.6.200024.

A cone beam CT based 3D-assessment of bony forefoot geometry after modified Lapidus arthrodesis

BACKGROUND

Modified Lapidus arthrodesis (MLA) is a well-established treatment modality for hallux valgus deformities (HVD) associated with instability of the first ray. Although the three-dimensional (3D) nature of HVD has long been recognized, diagnostics still focus on plain radiographs. The objective of this study was to validate 3D Cone Beam CT (CBCT) in the perioperative assessment of HVD with focus on the alignment of the forefoot.

METHODS

In a prospective clinical study, MLA was performed on 30 patients (25 females, 5 males; mean age: 63.2 years). Pre- and postoperatively standard radiographs and CBCT with full weight-bearing were acquired. For the CBCT based assessment, reproducible criteria have been defined, measured, and correlated with established radiological indicators.

RESULTS

Evaluation of standard radiographic parameters (hallux-valgus angle [HVA], intermetatarsal angle 1-2 [IMA 1-2], distal metatarsal articular angle [DMAA], tibial sesamoid position [TSP]) showed significant improvement postoperatively. Comparison of measurements obtained from plain radiographs and CBCT were significantly correlated between both measuring techniques, indicating high reliability. Pronation of the first metatarsal and the sesamoids were significantly reduced by the procedure. Due to this repositioning effect, the second metatarsal head was elevated by 3.1mm, and the lateral sesamoid was lowered by 3.8mm. However, there was no correlation between the amount of pronation and conventional radiographic measures.

CONCLUSIONS

Compared to plain radiographs, CBCT allows a more detailed view of the forefoot alignment in the coronal plain after MLA. MLA was able to recenter the sesamoids under der first metatarsal head and conversely led to elevation of the second metatarsal head.

Three-dimensional displacement after a medializing calcaneal osteotomy in relation to the osteotomy angle and hindfoot alignment

BACKGROUND

A medializing calcaneal osteotomy is frequently performed to correct adult-acquired flatfoot deformities, but there is lack of data on the associated three-dimensional variables defining the final correction. The aim of this study was to assess the correlation between the pre-operative hindfoot valgus deformity and calcaneal osteotomy angles and the post-operative calcaneal displacement.

METHODS

Weight-bearing CT scans obtained pre- and post-operatively were retrospectively analyzed for sixteen patients. Corresponding three-dimensional bone models were used to measure valgus deformity pre- and post-operatively, inclination of the osteotomy and displacement of the calcaneus. Linear regression was conducted to assess the relationship between these measurements.

RESULTS

On average, the hindfoot valgus changed from 13.1° (±4.6) pre-operatively to 5.7° (±4.3) post-operatively. A mean inferior displacement of 3.2mm (±1.3) was observed along the osteotomy with a mean inclination of 54.6° (±5.6), 80.5° (±10.7), -13.7° (±15.7) in the axial, sagittal and coronal planes, respectively. A statistically significant positive relationship (p<.05, R²=0.6) was found between the pre-operative valgus, the axial osteotomy inclination, and the inferior displacement.

CONCLUSIONS

This study shows that the degree of pre-operative hindfoot valgus and the axial osteotomy angle are predictive factors for the amount of post-operative inferior displacement of the calcaneus. These findings demonstrate the added value of a computer-based pre-operative planning in clinical practice. Level of evidence II Prospective comparative study.

Evaluation of computed tomography post-processing images in postoperative assessment of Lisfranc injuries compared with plain radiographs

Background

The objective of this study is to evaluate the value of computed tomography (CT) post-processing images in postoperative assessment of Lisfranc injuries compared with plain radiographs.

Methods

A total of 79 cases with closed Lisfranc injuries that were treated with conventional open reduction and internal fixation from January 2010 to June 2016 were analyzed. Postoperative assessment was performed by two independent orthopedic surgeons with both plain radiographs and CT post-processing images. Inter- and intra-observer agreement were analyzed by kappa statistics while the differences between the two postoperative imaging assessments were assessed using the χ² test (McNemar’s test). Significance was assumed when p < 0.05.

Results

Inter- and intra-observer agreement of CT post-processing images was much higher than that of plain radiographs. Non-anatomic reduction was more easily identified in patients with injuries of Myerson classifications A, B1, B2, and C1 using CT post-processing images with overall groups (p < 0.05), and poor internal fixation was also more easily detected in patients with injuries of Myerson classifications A, B1, B2, and C2 using CT post-processing images with overall groups (p < 0.05).

Conclusions

CT post-processing images can be more reliable than plain radiographs in the postoperative assessment of reduction and implant placement for Lisfranc injuries.

Intraoperative 3-Dimensional Computed Tomography and Navigation in Foot and Ankle Surgery

Computer-assisted orthopedic surgery has developed dramatically during the past 2 decades. This article describes the use of intraoperative 3-dimensional computed tomography and navigation in foot and ankle surgery. Traditional imaging based on serial radiography or C-arm-based fluoroscopy does not provide simultaneous real-time 3-dimensional imaging, and thus leads to suboptimal visualization and guidance. Three-dimensional computed tomography allows for accurate intraoperative visualization of the position of bones and/or navigation implants. Such imaging and navigation helps to further reduce intraoperative complications, leads to improved surgical outcomes, and may become the gold standard in foot and ankle surgery. [Orthopedics.2016; 39(5):e1005-e1010.].

Preoperative radiography versus computed tomography for surgical planning for ankle fractures

PURPOSE

To review preoperative radiography and computed tomography (CT) of the ankle in 69 patients who underwent surgery for ankle fractures to determine the value of CT in diagnosis and surgical planning.

METHODS

Preoperative radiography and CT of the ankle of 46 women and 23 men aged 17 to 90 (mean, 48.8) years were reviewed. CT was deemed necessary when radiographs showed the following features: (1) comminuted fracture of the medial malleolus involving the tibial plafond, (2) comminuted fracture of the posterior malleolus, (3) presence of loose bodies, and/or (4) suspected Chaput or Volkman fracture fragment. Two orthopaedic surgeons independently reviewed the radiographs to look for any of the above features for which CT was indicated. In patients whose radiographs did not show any of the above features, each surgeon formulated a surgical plan based on radiographs alone and decided if any modification was needed after reviewing the CT scan.

RESULTS

Based on radiographs of the 69 patients, 19 (28%) patients had features of posterior malleolar comminution (n=7), medial malleolar comminution (n=7), suspected Chaput fracture fragment (n=1), suspected Volkman fracture fragment (n=1), and combination of 2 lesions (n=3), and were deemed to require CT. In 10 (20%) of the remaining 50 patients, the surgical plan was modified after review of the CT scan. The intra- and inter-observer agreement was good to excellent.

CONCLUSION

Radiography alone is not adequate for surgical planning for ankle fractures. More accurate imaging tools such as CT are needed to enable a more accurate diagnosis and surgical planning.

ADVANCED 3D RAPID PROTOTYPING BIOMODELING TECHNIQUE FOR KNEE SURGERY

Advanced three-dimensional (3D) models have played more and more essential roles in orthopedics surgical interventions. In order to improve the clinical outcomes of knee surgery (KS) including minimally invasive knee surgery (MIKS), the melted extrusion modeling (MEM), a rapid prototyping (RP) technique, was used efficiently to fabricate real life-size 3D physical models of interesting knees. The applications and advantages of the tangible RP-constructed 3D models in KS were elucidated in this study. As a result, better preparation including optimal preoperative planning was made so that KS could be performed in an accurate, safe and fast manner for each case. Besides, the surgical skills of MIKS were substantially improved. Therefore, the results suggest that KS can benefit much from the advanced 3D modeling technique.

PedCAT for 3D-imaging in standing position allows for more accurate bone position (angle) measurement than radiographs or CT

BACKGROUND

PedCAT (Curvebeam, Warrington, USA) is a new technology that allows 3D-imaging with full weight bearing which is not influenced by projection and/or foot orientation (as radiographs). The aim of this study was to compare time spent of the image acquisition, and comparison of specific bone position (angle) measurements between three imaging methods (radiographs, CT, pedCAT), and to analyze and compare measurement differences and inter- and intraobserver reliability.

METHODS

In a prospective consecutive controlled study, 30 patients in which standard digital radiographs with full weight bearing in standing position (feet bilateral dorsoplantar and lateral views and Saltzman hindfoot view), CT without weight bearing, and pedCAT scan with full weight bearing in standing position were included, starting July 1, 2013. The following angles were measured for the right foot by three different investigators three times: 1st - 2nd intermetatarsal angle, talo-metatarsal 1-angle (TMT) both dorsoplantar and lateral projection, hindfoot angle, calcaneal pitch. The angles were digitally measured and compared (ANOVA with Post Hoc Scheffe test).

RESULTS

The angles differed between radiographs, CT and pedCAT (ANOVA, all p≤.01). The angles differed between pedCAT and both radiographs and CT (Post Hoc Scheffe test, each p≤.05 except for TMT dorsoplantar and calcaneal pitch angels versus radiographs).

CONCLUSIONS

The angles differed between radiographs, CT and pedCAT, indicating that only pedCAT is able to detect the correct angles. PedCAT includes weight bearing in contrast to CT. PedCAT prevents inaccuracies of projection and foot orientation in contrast to radiographs due to the 3D dataset which is principally independent from projection and foot orientation.