Minimally Invasive Foot and Ankle Surgery: A Primer for Orthopaedic Surgeons

A Novel Simulation Model and Training Program for Minimally Invasive Surgery of Hallux Valgus

BACKGROUND

Minimally invasive surgery (MIS) for hallux valgus (HV) has gained popularity. However, adopting this technique faces the challenges of a pronounced learning curve. This study aimed to address these challenges by developing and validating an innovative simulation model and training program, targeting enhanced proficiency in HV MIS.

METHODS

A training program and a high-fidelity simulation model for HV MIS were designed based on experts' recommendations. Four foot and ankle surgeons without experience in MIS formed the novice group and took the program that encompassed six-session instructional lessons, hands-on practice on simulated models, and immediate feedback. The program concluded with a cadaveric surgery. Four foot and ankle experienced MIS surgeons formed the expert group and underwent the same procedure with one simulated model. Participants underwent blind assessment, including Objective Structured Assessment of Technical Skills (OSATS), surgical time, and radiograph usage.

RESULTS

Expert evaluation of the simulation model indicated high satisfaction with anatomical representation, handling properties, and utility as a training tool. The expert group consistently outperformed novices at the initial assessment across all outcomes, demonstrating OSATS scores of 24 points (range, 23 to 25) versus 15.5 (range, 12 to 17), median surgical time of 22.75 minutes (range, 12 to 27) versus 48.75 minutes (range, 38 to 60), and median radiograph usage of 70 (range, 53 to 102) versus 232.5 (range, 112 to 280).

DISCUSSION

Novices exhibited a significant improvement in OSATS scores from the fifth session onward (P = 0.01), reaching the desired performance of 20 points. Performance at the final training with the simulated model did not differ from cadaveric surgery outcomes for all parameters.

CONCLUSION

This study validated a simulation model and training program, allowing nonexperienced HV MIS foot and ankle surgeons to enhance their surgical proficiency and effectively complete a substantial portion of the learning curve at the fifth session, and this performance was successfully transferred to a cadaver model.

LEVEL OF EVIDENCE

III.

A comparison of three techniques for the osteosynthesis after minimal invasive osteotomies for hallux valgus

PURPOSE

Third and fourth-generation minimal invasive osteotomies (MIO) for the treatment of hallux valgus (HV) have become popular procedures worldwide with promising results due to the improvement in the fixation method. The tricortical cannulated screw placement remains a complex procedure that is technically challenging and requires a long skill learning curve with high radiation exposure mainly in the form of intensifier shots (IS) required for the MIO fixation. This study aims to compare the number of X-ray IS required using three different techniques for the cannulated guide placement.

METHODS

A retrospective cross-sectional observational and comparative study was conducted to assess the number of X-rays IS required for correct cannulated screw guide placement using three different techniques: traditional perforator, the drill and joystick, and K-wire first techniques.

RESULTS

A total of 53 MIS procedures from thirty-one patients in two different hospitals were included. IS X-rays were 155.1 ± 29.7 in the traditional technique (n = 14), 143.0 ± 43.2 in the drill and joystick technique (n = 22), and 85 ± 18.7 in the K-wires first technique (n = 17), p =  < 0.001 using one-way ANOVA.

CONCLUSIONS

The K-wire first technique statistically significantly decreases X-ray IS numbers p ≤ 0.001. There were no statistically significant differences between the traditional (after osteotomy K-wire placement) and the drill and joystick techniques (p = 0.36).

Minimally Invasive vs Open Approach for First Metatarsophalangeal Joint Arthrodesis: Short Report of Early Results

BACKGROUND

We aim to compare early surgical results between groups who underwent minimally invasive surgery (MIS) vs open first metatarsophalangeal (MTP) arthrodesis to treat end-stage hallux rigidus.

METHODS

We conducted a retrospective cohort review of 65 patients who underwent a first MTP fusion procedure at an academic medical center between 2015 and 2023. Success of fusion was determined radiographically. Postoperative complications were identified through medical record review.

RESULTS

Sixty-seven first MTP fusion surgeries (41 open and 26 MIS) were performed on 65 patients with a primary diagnosis of hallux rigidus. Open surgery and MIS groups had similarly high fusion rates: 95% (39/41) and 96% (25/26), respectively (P = .84). We identified no difference in overall complication rates: 20% for open surgery and 23% for MIS (P = .73).

CONCLUSION

This retrospective analysis of 67 first MTP arthrodesis procedures showed no significant differences in fusion success or complications in the short term when comparing MIS to open surgery. Further studies are needed to elucidate potential differences between MIS vs open surgery.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Comparison of Minimally Invasive Chevron Akin and Open Lapidus Surgery in Older Patients at a Minimum 1-Year Follow-Up

Background

Hallux valgus deformity affects more than 35% of people aged ≥65 years. Surgical correction in this population can be more complicated because of poor bone quality, worse deformity, and postoperative recovery challenges. The purpose of this study was to compare the radiographic and clinical outcomes of patients aged ≥65 years who underwent either open Lapidus or minimally invasive chevron Akin osteotomy for bunion correction.

Methods

A retrospective review identified 62 patients aged ≥65 years who were treated surgically for hallux valgus with at least 1-year postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores (physical function and pain interference). Preoperative and at least 6-month postoperative radiographs were measured for the hallux valgus angle and intermetatarsal angle. PROMIS scores were obtained preoperatively and at 1 and/or 2 years postoperatively. Differences in demographic, clinical, and radiographic outcomes were assessed using the Mann Whitney U test and P values were adjusted for a false discovery rate of 5%.

Results

There was no difference between the MIS and open cohorts in pre- or postoperative radiographic measurements or clinical outcomes at any time point. At 1 year postoperatively, both groups had statistically significant improvements in the PROMIS pain interference domain but only the MIS group had a statistically significant improvement in the PROMIS physical function domain. Clinical significance was equivocal. At 2 years postoperatively, there were clinically and statistically significant improvements in the PROMIS pain interference and physical function domains for the open and MIS groups.

Conclusion

Patients in both surgical groups had improvement in radiographic measurements and 2-year PROMIS scores, although there was no clinical or statistical difference found between groups. MIS and open surgical techniques appear to be safe and effective in correcting hallux valgus in older patients; however, patients may need to be counseled that maximum improvement after surgery may take more than 1 year.

Level of Evidence

Level III, retrospective cohort study.

Effect of sequential burr passes on minimally invasive akin and first metatarsal dorsiflexion osteotomies

BACKGROUND

Minimally invasive surgical (MIS) osteotomies are increasing as a surgical option for treating midfoot and forefoot conditions. This study aimed to evaluate the impact of each burr pass on the degree of correction, gap size, and alignment in MIS Akin and first metatarsal dorsiflexion osteotomies (DFO).

METHODS

MIS Akin and first metatarsal DFO were performed on ten cadaveric specimens. Fluoroscopic measurements included the metatarsal dorsiflexion angle (MDA), dorsal cortical length (MDCL), first phalangeal medial cortical length (PCML) and proximal to distal phalangeal articular angle (PDPAA).

RESULTS

The average decrease in PCML with each burr pass was as follows: 1.53, 1.33, 1.27, 1.23 and 1.13 mm at the 1st to 5th pass, respectively. The MDCL sequentially decreased by 1.80, 1.59, 1.35, 0.75, and 0.60 mm. The MDA consistently decreased, and the PDPAA incrementally became more valgus oriented.

CONCLUSION

On average, a first metatarsal dorsal wedge resection of 4.7 mm and first phalangeal medial wedge resection of 2.9 mm was achieved after 3 and 2 burr passes, respectively. This data may aid surgeons determine the optimal number of burr passes required to achieve the desired patient-specific surgical correction.

Improving the Accuracy of Metatarsal Osteotomies in Minimally Invasive Foot Surgery Using a Digital Inclinometer: Preliminary Study

Minimally invasive foot surgery (MIS) has become a common procedure to treat various pathologies, and accuracy in the angle of metatarsal osteotomies is crucial to ensure optimal results. This randomized controlled trial with 37 patients investigates whether the implementation of a digital inclinometer can improve the accuracy of osteotomies compared to traditional freehand techniques. Patients were randomly allocated to group A (n = 15) receiving inclinometer-assisted surgery or group B (n = 22) receiving conventional surgery. Osteotomies were performed and outcomes were evaluated using an inclinometer. The inclinometer group showed a significant decrease in plantar pressure from 684.1 g/cm2 pretreatment to 449.5 g/cm2 post-treatment (p < 0.001, Cohen's d = 5.477). The control group decreased from 584.5 g/cm2 to 521.5 g/cm2 (p = 0.001, Cohen's d = 0.801). The effect size between groups was large (Cohen's d = -2.572, p < 0.001). The findings indicate a significant improvement in accuracy and reduction in outliers when using an inclinometer, suggesting that this technology has the potential to improve surgical practice and patient outcomes in minimally invasive metatarsal osteotomies.

Perspectives and trends for minimally invasive surgery for hallux valgus deformity in the Asia Pacific region

BACKGROUND

Evolving evidence and improved instrumentation have led to increasing importance of minimally invasive surgery (MIS) surgery in the treatment of hallux valgus deformity. This study aims to investigate the current trends of the practice of MIS hallux valgus surgery in the Asia Pacific region.

METHOD

A survey was sent via email to 30 fellowship-trained foot and ankle surgeons in 11 Asia Pacific countries, all registered with their respective national orthopaedic societies. The survey consisted of 8 questions and was designed to assess surgeon experience with MIS hallux valgus surgery, including common contraindications, satisfaction levels, learning curves and post-operative rehabilitation after MIS hallux valgus surgery.

RESULTS

The vast majority of surgeons (63%) performed MIS hallux valgus surgery. However, only 18% of surgeons performed MIS surgery in more than half of their hallux valgus cases. A severe deformity was the most common contraindication (81%), followed by the instability of the first tarsometatarsal joint (50%), and abnormal DMAA (Distal Metatarsal Articular Angle) (38%). There was no statistically significant difference between the satisfaction score of MIS versus open surgery (p-value 0.1). The median number of cases the surgeons needed to perform before they considered themselves comfortable performing the surgery was 10 cases (range 1-100). Most surgeons allowed full weight bearing at 4-6 weeks after surgery.

CONCLUSIONS

MIS hallux valgus surgery is gaining popularity in the Asia Pacific region, with the majority of surgeons adopting this practice. The fact that severe deformity is seen as the most frequent contraindication and that MIS surgery is still not the most popular alternative demonstrates that surgeons are still circumspect when it comes to MIS surgery. Surgeons can use the findings of this study to guide their adoption of MIS practices in hallux valgus surgery and gauge well they perform in comparison to their counterparts in the Asia Pacific region.