Preliminary Results and Learning Curve of the Minimally Invasive Chevron Akin Operation for Hallux Valgus

The Learning Curve in Hallux Valgus Surgery

For any surgical technique, the learning curve is the number of times a particular procedure must be undertaken in order to complete it repeatedly with high accuracy and proficiency. Scientifically, a difficult task to master is represented by a flat learning curve, as the steep portion of the learning curve would correlate with rapid learning. Today, there's more literature on the learning curve of percutaneous HV surgery than on any other procedure in foot and ankle surgery. Due to the lack of conclusive research on traditional HV techniques, no comparison to modern percutaneous techniques is possible. The current literature suggests that it takes between 30-40 cases to gain sufficient proficiency in 3rd generation percutaneous hallux valgus correction.

Sesamoid correction achieved during the learning curve for Scarf-Akin osteotomy without lateral soft-tissue release: a single-centre prospective observational study

INTRODUCTION

Scarf-Akin osteotomy (with or without lateral soft-tissue release (LSTR)) is commonly performed to treat hallux valgus (HV). An insufficient correction of sesamoids can be a risk factor for early recurrence of the condition. We set out to determine 1) the radiographic correction achieved after Scarf-Akin osteotomy performed without LSTR and 2) the degree of correction of sesamoids obtained during the learning curve of the technique.

MATERIALS AND METHODS

In this prospective single-centre study, the first 25 feet (25 patients, mean age 55.2 years, 14 left) undergone Scarf-Akin osteotomy without LSTR by a single foot and ankle orthopaedic consultant in his first year of activity were enrolled and followed-up at 1-year. On weightbearing standard pre-operative and 1-year follow-up radiographs two independent observers (senior residents) assessed and compared the hallux valgus angle (HVA), 1st and 2nd intermetatarsal Angle (IMA), distal metatarsal articular angle (DMAA) and tibial sesamoid position (SP, according to the Hardy and Clapham system). The inter and intraobserver reliability of measurements along with the correlation between the improvement achieved in different parameters and the number of cases performed were tested. Intra and post-operative complications were compared between the early (first 12) and late learning periods.

RESULTS

The inter and intraobserver agreement for the radiographic parameters investigated was excellent in all cases (ICC always > 0.92). A statistically significant improvement in mean HVA (from 36 ± 9.8 to 16.3 ± 2.8 degrees), mean IMA (from 14.5 ± 2.3 to 9.9 ± 1.5 degrees), mean DMAA (from 19.4 ± 4.4 to 11.4 ± 1.9 degrees) and median SP (from 4 (IQR, 3-6) to 2 (IQR, 1-2) points) was demonstrated in the cohort (p < 0.001 in all cases). There was a strong positive significant correlation between the progression of cases over time and the improvement achieved in terms of SP (R = 0.60, p = 0.003). Conversely, no significant correlation was demonstrated when comparing the improvement obtained in HVA, IMA and DMAA with the number of cases performed (p > 0.05 in all cases). One complication occurred during the first 12 cases (1 transfer metatarsalgia) and 1 during the last 13 (1 intra-operative fracture).

CONCLUSION

In this series, a satisfactory correction of HV after Scarf-Akin osteotomy was obtained without releasing lateral soft-tissues. Beginner surgeons should be aware that restoring sesamoid position may be more challenging as compared to correcting other angles during the first cases.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Learning Curve for Minimally Invasive Surgery (MIS) for the Treatment of Hallux Valgus

IntroductionCorrection of hallux valgus through minimally invasive surgery (MIS) has grown in popularity in recent years. Despite the increase in use, there has been limited research into the learning curve associated with the procedure, which has been documented extensively for other MIS procedures. Our study looked to determine the learning curve associated with MIS hallux valgus surgery.MethodsA retrospective review was conducted of patients who underwent MIS hallux valgus surgery, performed by 2 foot and ankle fellowship-trained orthopaedic surgeons, between November 2021 and April 2023. Demographic information, procedure data, and postoperative data were collected for each patient. A multivariable analysis was conducted for each surgeon to determine the relationship between case number and operative duration, patient-reported outcomes, and complications. Findings were significant if P < .05.ResultsCase number was found to have a significant negative relationship with operative duration for both of our surgeons (β = -0.578, -0.736, R2 = 0.637, 0.426, P < .001, .02). There was no significant relationship between case number and patient-reported outcomes (P = .49, .408) or complications (P = .319, .387) for either surgeon.ConclusionWe established the presence of a learning curve for operative duration, but not for patient-reported outcomes or complications. Overall, our results are conflicting regarding the presence of a learning curve for MIS hallux valgus procedures. Further study with other institutions is needed to further elucidate the presence of a learning curve.Level of Evidence:III.

Short-term results of minimally invasive surgery using a 3D-printed guide for the treatment of hallux valgus

INTRODUCTION

Minimally invasive surgery (MIS) is often used to treat hallux valgus deformities, as it is associated with few wound complications and shorter recovery times. Minimally invasive chevron osteotomy and Akin osteotomy (MICA) is a common minimally invasive treatment for HV. However, effective correction of hallux valgus and precise screw placement during MIS are difficult. The aim of this study was to introduce and evaluate the clinical and radiographic effectiveness of a novel MIS technique involving the use of a 3D-printed guide for hallux valgus.

MATERIALS AND METHODS

We retrospectively studied the results of MIS with a 3D-printed guide plate for symptomatic hallux valgus from May 2022 to December 2023. The preoperative and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), first metatarsal pronation angle (M1PA), tibial sesamoid position (TSP), forefoot width, visual analogue scale (VAS) score, AOFAS Hallux MTP-IP score, and the number of intraoperative fluoroscopy were measured.

RESULTS

A total of 22 feet in 19 patients were included in the study. There were 15 women and 4 men with an average age of 38.0 y (range 16-61). The preoperative HVA, IMA, DMAA and M1PA were 30.3 ± 10.7°, 13.9 ± 2.8°, 8.3 ± 2.9° and 16.3 ± 6.5°, respectively. The postoperative HVA, IMA, DMAA and M1PA were 10.7 ± 4.1°, 5.7 ± 1.8°, 2.3 ± 1.7° and 3.5 ± 2.1°, respectively. The forefoot width decreased from 92.1 ± 5.5 mm to 85.6 ± 5.4 mm on average. The VAS and TSP ranged from 4.4 ± 0.9 and 4.9 ± 0.8 to 0.3 ± 0.6 and 2.0 ± 1.1, respectively. The AOFAS Hallux MTP-IP scores improved from 59.1 ± 10.7 to 94.8 ± 5.7 on average. The average number of fluoroscopy shots during operation were 34 times (range 30 to 38).

CONCLUSIONS

A 3D printed guide technique can be beneficial for precise positioning of the first metatarsal head, enhancing the accuracy of screw placement, and reducing radiation exposure.

The Learning Curve of Reverdin-Isham and Akin Percutaneous Osteotomies for Hallux Valgus Correction: A Bayesian Approach

Background/Objectives: Assessing the learning curve is essential for surgical techniques that require precision and technical adaptation. Although modified Reverdin-Isham and Akin percutaneous osteotomies (RIAOs) are well-established procedures for the treatment of hallux valgus (HV), their percutaneous nature and specific technical demands justify the evaluation of the learning curve. Therefore, this study aimed to assess the learning curve of RIAOs for the HV correction, using for the first time a Bayesian approach. Methods: Modified RIAOs were applied to treat mild-to-moderate HV in patients who were prospectively enrolled. The hallux valgus angle (HVA), inter-metatarsal angle (IMA), distal metatarsal articular angle (DMAA) and tibial sesamoid position were assessed. Clinical outcomes were evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) Scale, Visual Analog Scale (VAS) and Numerical Rating Scale (NRS). Surgery and fluoroscopy times were recorded. To evaluate the learning curve, a Bayesian analysis using a change point model was performed. Results: Analysis of 142 patients revealed three distinct phases in the learning curve, with a plateau reached after 112 procedures. Over time, the mean operation duration decreased from 55 to 27 min, and fluoroscopy time decreased from 60 to 28 s. Conclusions: A flexible change point model was used to model a learning curve, guaranteeing a robust interpretation of the data. The correction of the HV angles showed similar results in the three phases of the curve, demonstrating that the surgeon achieved positive results from the beginning of the surgery.

The causal relationship between hallux valgus and endogenous pathogenic factors: A 2-sample Mendelian randomization

Notably, several factors are associated with hallux valgus (HV); however, their causal relationship remains unclear. In this study, a 2-sample Mendelian randomization (MR) analysis was performed to investigate the casual relationship between 9 endogenous risk factors and HV, aiming to provide a foundation for the clinical management of HV. Exposure factors such as body mass index (BMI), BMI (male), BMI (female), acquired flatfoot, rheumatoid arthritis, gout, knee osteoarthritis, hip osteoarthritis, and Ehlers-Danlos syndrome were considered, with HV as the outcome. Exposure and outcome data were obtained from the IEU Open Genome-wide association study project, UK Biobank, and FinnGen project. Strongly correlated (P < 5×10-08/5×10-06) single nucleotide polymorphisms (SNPs) were selected from the exposure dataset, and those associated with exposure were selected from the HV dataset. The intersection of these SNPs was used as instrumental variables. Five modes were used for the analysis: inverse variance-weighted (IVW), MR-Egger regression, weighted median (WME), simple mode, and weighted mode. MR analysis results of BMI show that except for MR-Egger, the other 4 modes are significant (P < .05), and the β directions are consistent among the 5 methods. For the 4 BMI (male) methods, except for the simple mode, the P- and β-values of the other results all suggest a positive causal relationship between BMI (male) and HV. Flatfoot-IVW and WME results were <.05, indicating statistical significance, whereas MR-Egger, simple mode, and median mode had no statistical significance. However, their β-values were consistent with those of IVW and WME. Further mediation MR analysis suggested that the effect mediated by HV accounts for 13.33% [95% CI (0.03-0.24)] of the total causal effect between the BMI and flatfoot, indicating HV as a mediator of the causal relationship between the BMI and flatfoot. However, the remaining 6 factors had no direct causal association with HV (P < .05). Flatfoot in all patients and elevated BMI in males are directly associated with HV. Therefore, treating acquired flatfoot and controlling the BMI to prevent HV are recommended.

Modified minimally invasive chevron osteotomy versus traditional incision chevron osteotomy

PURPOSE

This study aimed to compare modified minimally invasive chevron osteotomy (MIC group) and traditional incision chevron osteotomy (TIC group) for correction of mild to moderate hallux valgus deformity.

METHODS

This retrospective study enrolled 42 patients (60 feet) with mild to moderate hallux valgus deformities who were treated with modified MIC osteotomy or TIC osteotomy between January 2020 and June 2021. The patients were divided into the MIC and TIC groups according to whether the treatment received was minimally invasive. The MIC group included 20 patients (28 feet), comprising 1 male and 19 female patients; aged 37.15 ± 14.60 years, with mild hallux valgus deformity in 12 cases (14 feet) and moderate hallux valgus deformity in 8 cases (14 feet). In the TIC group comprising 22 patients (32 feet), including 1 male and 21 female patients, aged 40.95 ± 11.60 years, mild and moderate hallux valgus deformities were observed in 10 (18 feet) and 12 cases (14 feet), respectively. Preoperatively and at the last follow-up, the American Orthopedic Foot and Ankle Society (AOFAS) hallux, lesser toe score, and visual analog scale (VAS) pain were used to evaluate clinical efficacy. The hallux valgus angle (HVA), 1-2 metatarsal angle (1-2IMA), and distal metatarsal articular angle (DMAA) were measured and compared on the weight-bearing X-ray film of the foot preoperatively and postoperatively. At the last follow-up, recurrence of hallux valgus deformity, hallux adduction deformity, metatarsal head necrosis, metastatic plantar pain, and other complications were recorded.

RESULTS

All 42 patients were followed up, and the follow-up time of the MIC group was 24.70 ± 6.63 months; The follow-up time of the TIC group was 22.82 ± 6.12 months, and there was no significant difference in follow-up time between the two groups (P > 0.05). One patient in the MIC group experienced pain in the dorsal side of the front foot postoperatively; one patient in the TIC group had a superficial infection of the incision postoperatively. There were no significant differences in age, gender, side classification, course of the disease, degree of hallux valgus deformity, and postoperative complications between the two groups (P > 0.05). The AOFAS scores, VAS, HVA, 1-2IMA, and DMAA in the MIC group improved from 54.61 ± 7.60, 4.50 ± 0.79, 28.38° ± 5.02°, 12.88° ± 1.50°, 12.03° ± 1.88°preoperatively to 89.93 ± 4.96, 2.04 ± 1.10, 10.27° ± 1.68°, 7.49° ± 0.95° and 7.83° ± 1.33° at the last follow-up, the difference was statistically significant (P < 0.05); the AOFAS score, VAS, HVA, 1-2IMA, and DMAA of the TIC group improved from 57.31 ± 7.59, 4.34 ± 0.70, 28.45° ± 4.47°, 12.88° ± 1.50°, 12.16° ± 1.81° preoperatively to 87.97 ± 5.96, 2.00 ± 1.11, 10.99° ± 2.25°, 7.49° ± 0.95°, and 8.25° ± 1.12° at the last follow-up, the difference was statistically significant (P < 0.05), but there was no significant difference in AOFAS score, VAS, HVA, 1-2IMA, and DMAA between the two groups (P > 0.05). The incision length of the MIC group was 2.06 ± 0.20 cm, and the incision length of the TIC group was 5.04 ± 0.54 cm, which was statistically significant (P < 0.05).

CONCLUSION

Whether it is modified minimally invasive chevron osteotomy or traditional incision chevron osteotomy, mild and moderate hallux valgus deformity is effectively treated, and the clinical efficacy and imaging results after surgery are significantly improved. Compared with traditional incision chevron osteotomy, the modified minimally invasive chevron osteotomy has a smaller incision and less trauma for mild to moderate hallux valgus.

Research progress in the etiology and minimally invasive therapy of hallux valgus

Hallux valgus (HV) is the most common foot deformity. It has various pathogenic factors that make its pathogenesis challenging to understand. As the disease progresses, patients experience amplified pain and decreased activities, significantly affecting their quality of life. At present, clinics offer several conservative and surgical treatments that must be selected based on patient condition and disease progression. Surgical treatment is frequently the only method available to patients with HV to delay disease progression and correct the deformity after conservative treatment fails. In recent years, minimally invasive surgical treatments have gained significant attention and developed rapidly due to their well-known advantages, such as safety, efficiency, and quick recovery time. The number of literature that provides a systematic review of the subject must be increased. This review tracks recent advancements, summarizing the etiological mechanism, epidemiology, diagnosis, and treatment of HV. In addition, it emphasizes typical surgical therapies and focuses on the progress of minimally invasive treatment from the first generation to the current fourth generation. This review will serve as a systematic basis for the clinical treatment of HV and provide a reference material for future research.

Radiological safety atlas of minimally invasive midfoot fusion: A cadaver study

PURPOSE

The popularity of minimally invasive (MIS) foot surgery continues to grow. However, it comes with certain limitations that present notable challenges. One significant hurdle is the absence of direct visualization of neurovascular structures and tendons. The objective of this study is to present fluoroscopic heatmaps that illustrate the trajectories of major structures encountered during MIS midfoot procedures.

METHODS

Sequential dissection was performed on nine below-knee cadaveric specimens and critical structures were identified and marked, including anterior tibialis tendon (ATT), extensor hallucis longus tendon (EHL), extensor digitorum longus tendon (EDL), superficial peroneal nerve (SPN) and dorsal neurovascular bundle (DNVB) were dissected. Subsequently, flexible wires were positioned and securely placed adjacent to the medial and/or lateral borders of these structures to visualize their trajectories on X-ray imaging. Anteroposterior (AP) and oblique fluoroscopic images of the foot, featuring a calibration marker, were obtained alongside standard photographs. All fluoroscopy images were adjusted to a uniform scale and standardized to a single foot fluoroscopy. The coordinates of the structures were marked on these standardized foot AP and oblique fluoroscopic views. These coordinates were then utilized to generate heatmaps.

RESULTS

Successfully generated heatmaps encompassed the DNVB, ATT, EDL, EHL, and SPN, on AP and oblique fluoroscopic images of the foot. The color gradient used visually represents varying magnitudes, with red indicating the most frequent locations of the structures and blue signifying lower occurrences. These heatmaps also illustrate the highest-risk areas for iatrogenic injury to the structures during MIS procedures.

CONCLUSION

This study can empower surgical navigation and improve safety in MIS midfoot procedures by providing surgeons with a fluoroscopic heatmap detailing the trajectories of major anatomical structures. The findings from this study present a valuable opportunity to improve surgical accuracy and safety.

Anatomical and Micro-CT Assessment of the First Metatarsal Head Vascularization and Soft Tissue Envelope Following Minimally Invasive Chevron Osteotomy for Hallux Valgus Deformity

BACKGROUND

Minimally invasive surgical (MIS) chevron-type osteotomy for hallux valgus (HV) treatment offers a surgical alternative to open surgery with minimal surgical dissection and a hypothetical decreased risk for soft tissue complications. The objectives of this study were to assess the incidence of injuries to the soft tissue envelope and to the blood supply of the first metatarsal head through gross dissection and, using micro-computed tomography (micro-CT), to identify the safe position to perform the MIS chevron-type osteotomy of the first metatarsal head based on the anatomical data.

METHODS

Twenty cadaveric specimens with HV were used for the study. Seven specimens were perfused with a low-viscosity radiopaque polymer preoperatively. All specimens underwent MIS chevron-type osteotomy executed using a 20 × 2-mm Shannon burr at the metatarsal neck's flare. Anatomical dissection of all specimens was then performed to assess macroscopic injury to the first metatarsal head complex soft tissue structures and blood supply. The 7 specimens that were preinjected then underwent micro-CT assessment to assess the first metatarsal head blood supply.

RESULTS

Two soft tissue injuries in 2 cadavers were identified, including a 2-mm injury to the flexor hallucis brevis in one specimen and a 1-mm injury to the dorsomedial nerve. No arterial injuries were identified in either the gross dissection or micro-CT imaging. Micro-CT has pinpointed a secure location to complete the chevron-type osteotomy. We found that finalizing the dorsal arm of the MIS chevron-type osteotomy at a median distance of 25.6 mm, and the plantar arm at 23.9 mm from the most distal point of the first metatarsal head, ensured safety in the specimens we used.

CONCLUSION

As tested in this cadaveric study on 20 specimens, the MIS chevron-type osteotomy procedure preserved the soft tissue envelope of the first metatarsal head complex and the blood supply of the first metatarsal head, with a low number of injuries. Completing the dorsal arm of the MIS chevron-type osteotomy at a median distance of 25.6 mm, and the plantar arm at 23.9 mm from the furthest point of the first metatarsal head, while ensuring the Shannon burr does not exceed 3.9 mm dorsolaterally and 4.0 mm plantar-laterally from the cortical bone exit point, appeared crucial to avoid vascular damage.

Current concepts of fourth-generation minimally invasive and open hallux valgus surgery

Hallux valgus (HV) presents as a common forefoot deformity that causes problems with pain, mobility, footwear, and quality of life. The most common open correction used in the UK is the Scarf and Akin osteotomy, which has good clinical and radiological outcomes and high levels of patient satisfaction when used to treat a varying degrees of deformity. However, there are concerns regarding recurrence rates and long-term outcomes. Minimally invasive or percutaneous surgery (MIS) has gained popularity, offering the potential for similar clinical and radiological outcomes with reduced postoperative pain and smaller scars. Despite this, MIS techniques vary widely, hindering comparison and standardization. This review evaluates the evidence for both open Scarf and Akin osteotomy and newer-generation MIS techniques. Fourth-generation MIS emphasizes multiplanar rotational deformity correction through stable fixation. While MIS techniques show promise, their evidence mainly comprises single-surgeon case series. Comparative studies between open and MIS techniques suggest similar clinical and radiological outcomes, although MIS may offer advantages in scar length and less early postoperative pain. MIS may afford superior correction in severe deformity and lower recurrence rates due to correcting the bony deformity rather than soft-tissue correction. Recurrence remains a challenge in HV surgery, necessitating long-term follow-up and standardized outcome measures for assessment. Any comparison between the techniques requires comparative studies. Surgeons must weigh the advantages and risks of both open and MIS approaches in collaboration with patients to determine the most suitable treatment.

Results of Modified Minimally Invasive Hallux Valgus Surgery, Factors for the First Metatarsal Shortening, and Patients' Satisfaction

Background: Hallux valgus is a prevalent foot deformity conventionally treated with open surgical techniques, which carry risk of complications due to extensive soft tissue dissection. Minimally invasive surgeries (MISs) as alternatives offer comparable outcomes, reduced pain, and faster recovery; however, their challenges include the risk of shortening of the first metatarsal. This study aimed to assess the efficacy of our modified MIS hallux valgus correction technique and investigate the factors that affect first metatarsal shortening. Methods: Twenty-nine feet treated with modified MIS hallux valgus surgery between 2017 and 2022 were included with an average follow-up of 29 months. Clinical outcomes were evaluated with the Manchester-Oxford Foot Questionnaire (MOXFQ), Foot Function Index (FFI), and visual analog scale for pain. Radiographic evaluations included the intermetatarsal angle (IMA), hallux valgus angle (HVA), distal metatarsal articular angle (DMAA), first metatarsal length, and sesamoid grade. Results: Functional and radiographic outcomes were significantly improved (p < 0.0001 and p < 0.001, respectively). Significant correlations between patient satisfaction and the MOXFQ, FFI, and VAS scores were found, with no significant correlations between patient satisfaction and radiographic outcomes. Non-purchasing of the lateral cortex of the proximal osteotomy site was identified to increase risk of first metatarsal shortening (odds ratio [OR] = 22.09, p = 0.0064). Conclusions: Our modified MIS for hallux valgus correction showed favorable radiographic and functional outcomes. Proximal lateral cortex purchasing should be targeted to reduce postoperative shortening of the first metatarsal.

Correction potential and outcome of various surgical procedures for hallux valgus surgery: a living systematic review and meta-analysis

INTRODUCTION

More than 100 surgical techniques are described for hallux valgus (HV) correction, but the most appropriate technique remains debatable. The aim of this study was to develop and conduct a "living systematic review" for the outcome of surgically treated HV.

MATERIALS AND METHODS

The "living systematic review" was conducted per the PRISMA-P and PICOS guidelines and is the basis for the German AWMF S2e guideline "Hallux valgus" (033-018). Four common databases and the grey-literature were searched. Eligible were studies on adult patients comparing either two different primary surgical interventions or the same primary surgical intervention for different hallux valgus severities. The main outcome parameters were the osseous correction potential and the patient rated outcome.

RESULTS

Out of 3022 studies, 46 studies (100 arms) were included. The meta-analysis included 31 studies (53 arms). The IMA (1933 procedures) improved on average by 7.3°, without significant group differences. The HVA (1883 procedures) improved on average by 18.9°, with significantly better results for third generation MIS (21.2°). The AOFAS (1338 procedures) improved on average by 33.8 points without significant group differences. The meta-regression revealed constant AOFAS scores over time. 69%/39% of the correction potential for the IMA/HVA could be explained by the preoperative values and 82% of the AOFAS improvement by the preoperative AOFAS scores.

CONCLUSION

Open and minimally invasive techniques are powerful tools to correct hallux valgus deformity. Third generation MIS procedures revealed a possible superiority for the correction of the HVA. The AOFAS improvement appeared to be constant over time.

LEVEL OF EVIDENCE

Level I; living systematic review and meta-analysis of prospective comparative studies (level II) and randomized controlled trials (level I).

Patient-reported outcome measures in studies on hallux valgus surgery: what should be assessed

INTRODUCTION

In recent years, there has been an increasing demand for patient-reported outcome measures (PROMs) to assess the outcome following orthopedic surgery. But, we are lacking a standard set of PROMs to assess the outcome of hallux valgus surgery. The aim of this study was to analyze the chosen patient rated outcome scores used in studies reporting on hallux valgus surgery.

MATERIALS AND METHODS

The study was based on a previously published living systematic review. Included were prospective, comparative studies of different surgical procedures or the same procedure for different degrees of deformity. Four common databases were searched for the last decade. Study selection, data extraction, and risk of bias assessment were made by two independent reviewers. Data assessed were the individual PROMs used to assess the outcome of hallux valgus surgery.

RESULTS

46 studies (30 RCTs and 16 non-randomized prospective studies) met the inclusion criteria. The most commonly used clinical outcome measures were the AOFAS (55%) and the VAS (30%). No differences were found between frequency of the individual scores per the level of evidence or the type of osteotomy.

CONCLUSION

Based on a systematic literature review, the AOFAS and VAS are the most frequently used outcome tools in studies assessing the outcome following hallux valgus surgery. Based on the literature available, the MOXFQ is a more valid alternative.

LEVEL OF EVIDENCE

Level I; systematic review of prospective comparative (level II) and randomized controlled trials (level I).

Classification of hallux valgus deformity-is there a standard?

INTRODUCTION

Hallux valgus deformity severity is one determent for the surgical procedure for hallux valgus (HV) correction. HV deformities are usually classified into mild/moderate/severe. The aim was to investigate the cut-off criteria used to classify HV deformity.

MATERIALS AND METHODS

The study was based on a previous living systematic review. Four common databases were searched for the last decade. All review-steps were conducted by two reviewers. Data assessed were the individual cut-off values used to classify HV deformity into mild/moderate/severe, and the referenced classification systems.

RESULTS

46 studies were included. 21/18 studies grade deformity based on the intermetatarsal angle (IMA)/ hallux valgus angle (HVA) with great heterogeneity throughout the different cut-off values. The most referenced classification systems were the Coughlin and Mann's and the Robinson classification.

CONCLUSIONS

The currently used classification systems are heterogenic, and no standard could be defined. The community should define a uniform classification system.

LEVEL OF EVIDENCE

Level I, systematic review of randomized controlled trials and prospective comparative studies.

Evaluating the learning curve of Minimally Invasive Chevron and Akin Osteotomy for correction of hallux valgus deformity: a systematic review

BACKGROUND

One procedure that has gained popularity in the surgical management of hallux valgus is the minimally invasive Chevron and Akin osteotomy (MICA). The purpose of this systematic review was to evaluate the learning curve associated with this technically demanding procedure.

METHODS

A search of the EMBASE and PubMed databases was performed to identify all clinical studies that assessed the learning curve associated with the MICA procedure. Studies where patients were not diagnosed with hallux valgus, did not undergo MICA, or did not report data on operation time, fluoroscopy exposure, or complications were excluded. A risk of bias assessment was conducted to assess the validity of the studies.

RESULTS

The initial literature search yielded 287 studies, and seven studies were included in the final analysis. A quantitative comparative analysis could not be performed as the included studies used different statistical methods to quantify the learning curve. Lewis et al. determined that after 38 operations, there was a decrease in operation time and fluoroscopy exposure (p < .001). Merc et al. found that it took 29 and 30 operations to reach a plateau for operation time and fluoroscopy exposure, respectively (p < .001). Palmanovich et al. found that it took 20 and 26 operations to reach a plateau for operation time and fluoroscopy exposure, respectively (p < .001). Toepfer and Strässle found there was a significant decrease in operation time and fluoroscopy exposure after the first 19 procedures in their series (p < .001). With respect to complications, one study found a significant difference after the 42nd operation (p = .007). However, the remaining studies found that complication rates did not significantly change with increased technical proficiency. All seven studies were deemed to have a moderate risk of bias.

CONCLUSIONS

Surgeons can expect a learning curve of 20 to 40 operations before reaching technical proficiency with the MICA procedure. After the learning curve is achieved, surgeons can expect to see a significant decrease in both operation times and fluoroscopy exposure. No consistent significant difference was found in complications as one becomes more technically proficient with the procedure.

Zigzag tenotomy of the extensor hallucis longus through minimally invasive surgery in cadaveric specimens: description of a new technique

BACKGROUND

Lengthening of the extensor hallucis longus (EHL) is performed to address various forefoot pathologies. The retraction of this tendon is strongly associated with the Hallux Abductus Valgus (HAV) deformity. Minimally Invasive Surgery (MIS) lengthening of the EHL is carried out in combination with other surgical techniques for HAV bone realignment. It is performed without ischemia, using local anesthesia and sedation if required by the patient. One of the advantages of this technique is immediate ambulation with a postoperative shoe without the need for a cast. The objective of the research was to demonstrate the efficacy and safety of the minimally invasive technique for lengthening the tendon in patients with HAV.

MATERIALS AND METHODS

The procedures were performed on 11 fresh cryopreserved cadaveric feet. HAV surgery was performed through dorsomedial and dorsolateral portals for Reverdin-Isham, Akin and adductor tenotomy. In addition, EHL tendon elongation was performed using the Beaver 67 MIS scalpel through an incomplete zigzag tenotomy. The specimens used did not present any type of disease nor had they undergone previous surgeries that could affect the technique. First, the plantar flexion of the metatarsophalangeal joint was measured with a goniometer to establish the degrees of this joint before proceeding with the technique, the tenotomy was performed and remeasured and finally the osteotomy was performed. In addition, an anatomical dissection of cadaveric specimens was performed and various anatomical and surgical relationships were analyzed and measured.

RESULTS

The data indicate that, after performing zigzag tenotomy, there is an average improvement of 13.91 degrees in plantar flexion.

CONCLUSIONS

The study confirms the effectiveness and safety of elongating the extensor hallucis longus tendon of the hallux using minimally invasive surgery. The zigzag technique for tendon elongation may be considered a viable minimally invasive treatment option for addressing tendon hyperextension in patients with HAV.

Surgical Precision of MICA and Reverdin-Isham Using 3D-Printed Guides: A Cadaveric Study

Background/Objectives: Hallux valgus is a common foot deformity that requires surgical correction to restore proper alignment. Precision in the osteotomies performed during these surgeries is critical to avoid complications and improve outcomes. However, variability in surgeon experience can negatively affect precision. In this context, advances in 3D printing have enabled the development of customized surgical guides, which may enhance precision and reduce variability among surgeons with different levels of expertise. This study aims to evaluate the effectiveness of a 3D-printed surgical guide in minimally invasive hallux valgus correction, focusing on the accuracy of osteotomies performed by novice surgeons, experienced surgeons, and theoretically trained consultants. Methods: An ex vivo study was performed with 30 cadaveric feet, divided into three groups according to the level of experience of the surgeons: 3D guide group, Master's students, professionals. All surgeons performed Akin and Reverdin-Isham osteotomies, but the experimental group (the 3D guide group) utilized a customized 3D-printed surgical guide for enhanced precision during these procedures. Radiographic measurements of osteotomy angles and alignment were taken after the interventions, and compared with the planned values. Statistical analyses were conducted to evaluate the variability in the precision of the cuts. Results: The use of the 3D-printed surgical guide significantly reduced angular variability in the experienced group, achieving higher levels of accuracy than experienced surgeons. Effect sizes, which ranged from small to large, indicated a greater impact on angle measurements (η2 = 0.46, p < 0.001); no significant differences were found between the groups in other evaluated parameters. Conclusions: The incorporation of 3D-printed surgical guides in hallux valgus surgery significantly improves osteotomy accuracy, particularly in less experienced surgeons. This suggests that these guides can help standardize procedures, reduce the learning curve, and lower intraoperative complications.

Biomechanical model of minimally invasive hallux valgus surgery

Hallux valgus is a common foot deformity characterized by outward tilting and twisting of the big toe, often accompanied by a medial prominence at the base. Minimally invasive surgical techniques are widely utilized for treating metatarsus adductus due to their advantages of smaller incisions, faster recovery, and early weight-bearing. However, due to individual variations and limited sample size, the biomechanical effects of different Kirschner wire fixation methods and the underlying mechanisms of postoperative metatarsalgia remain unclear. In this study, a finite element method was employed to develop a biomechanical model of metatarsus adductus. The influence of various Kirschner wire entry points and angles on foot loading characteristics was investigated. Six different Kirschner wire fixation models, including two entry methods (along the adjacent fracture line and proximal-biased entry at the midshaft of the metatarsal) with different entry angles, were analyzed. Mechanical parameters such as metatarsal stress distribution, plantar pressure distribution, and displacement of the first metatarsal osteotomy plane were assessed. This research aims to enhance understanding of minimally invasive surgery and its fixation methods for metatarsus adductus. By providing scientific support and reliable evidence, it seeks to contribute to the development of minimally invasive surgical techniques and the improvement of clinical practice in metatarsus adductus surgery. Ultimately, the goal is to reduce complications, increase surgical success rates, and enhance patient satisfaction.

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.

Radiographic and Clinical Results of Minimally Invasive Chevron Akin Osteotomy for Moderate to Severe Hallux Valgus Deformities

BACKGROUND

Few studies have reported results of minimally invasive chevron Akin osteotomy (MICA) for moderate to severe hallux valgus correction. This study aims to evaluate MICA for moderate to severe hallux valgus radiographically and clinically.

METHODS

Forty feet were prospectively reviewed. Twenty-eight feet (70%) had a severe deformity (hallux valgus angle (HVA) ≥40° and/or first intermetatarsal angle (IMA) ≥18°). We measured HVA, IMA, lateral shape of the metatarsal head (round sign), tibial sesamoid position, first metatarsal shortening on anteroposterior weightbearing radiographs, and inclination angle of first metatarsal on lateral weightbearing radiographs. We evaluated the Japanese Society for Surgery of the Foot hallux scale and Self-Administered Foot Evaluation Questionnaire responses preoperatively and at the most recent follow-up.

RESULTS

All measurements except shortening and inclination angle improved significantly. Both clinical scale and all subscores significantly improved.

CONCLUSIONS

MICA improved moderate to severe hallux valgus both radiographically and clinically.Level of Evidence: Level IV: case series.

Minimally Invasive Chevron Akin: Locking The Metatarsal-Cuneiform Joint

INTRODUCTION

Minimally Invasive Chevron Akin (MICA) can be used to treat hallux valgus (HV) associated with a hypermobility of the first metatarsal-cuneiform joint (1MTCJ). The aim of this study was to perform a radiographic analysis of the MICA, focused on evaluating the 1MTCJ.

METHODS

Forty patients (50 feet) with moderate to severe HV underwent a MICA procedure. Radiographic analysis included hallux valgus angle (HVA), intermetatarsal angles between the first and second rays (IMA), the intermetatarsal angle between the proximal fragment of the osteotomy and the second ray (IAPF) and the distance between a point 3 cm distal from the base of the second metatarsal and a point located at the same height for the first metatarsal base (Dist 1-2). The IAPF was compared with the preoperative IMA, and the other parameters were compared preoperatively and postoperatively. The radiographic complications were also recorded.

RESULTS

Most patients were female (92%). The mean age was 50.4 years (SD = 16.1) and the mean follow-up was 16.1 months (SD = 3.5). The average HVA improved from 32.5° to 7.3°, and the average IMA from 14.2° to 4.2°. The IAPF and Dist1-2 values showed an increase of 4.8° and 4.0 mm respectively. There were no radiographic complications. Conclusion. Minimally invasive Chevron Akin promotes a great correction of the moderate to severe HV conventional parameters and increase the transversal stability of the 1MTCJ fixing this joint as medial as possible.

LEVEL OF EVIDENCE

Level IV, case series.

Clinical and radiological outcome of surgical hallux valgus correction: open versus minimally invasive

INTRODUCTION

Hallux valgus (HV) is the most common forefoot deformity. Surgical correction of HV aims to reduce pain, preserve joints, and re-establish foot function while restoring the hallux valgus angle (HVA) and intermetatarsal angle (IMA). Many surgical procedures have been proposed, including open and minimally invasive (MI) techniques. This study aimed to compare the midterm outcomes of open vs. MI procedures and their impact on the duration of surgery, hospital stay, HVA, and IMA post-operatively.

MATERIALS AND METHODS

One hundred and twenty HV patients operated by open or MI surgery between October 2019 and October 2022 were included. One hundred three patients met the inclusion criteria and consented to the study. Patients were prospectively surveyed for foot functionality, post-operative pain, and complications using the AOFAS score. Radiographic measurements of HV angles, length of hospital stay, and surgery duration were analysed.

RESULTS

MI surgery patients had significantly better AOFAS scores (p < 0.001) 12 months post-operatively compared to open surgery. Complication rates were lower in the MI group (3.8% vs. 33.3%, p < 0.001). MI surgery patients also had shorter hospital stays (0.9 ± 0.3 days vs. 2.0 ± 0.0 days) and surgery duration (19.7 ± 2.3 min vs. 80.7 ± 6.8 min). MI surgery was more effective in correcting the IMA but equally effective as open surgery for HVA correction.

CONCLUSION

MI surgery resulted in better patient satisfaction, fewer complications, and more precise correction of IMA values. Moreover, the duration of surgery and hospital stay were significantly lower in patients undergoing MI surgery. Further research is needed to validate these findings in controlled, prospective randomised trials.

The Effect of First Metatarsal Shortening and Sagittal Displacement on Forefoot Pressure in Minimally Invasive Hallux Valgus Correction

BACKGROUND

Minimally invasive (MIS) treatment of hallux valgus (HV) deformity is increasing in popularity. A 2-mm diameter burr is used to create a distal first metatarsal osteotomy prior to capital fragment translation and fixation. The metatarsal will shorten by the burr's diameter (2 mm). Plantar or dorsal capital fragment displacement may also cause load transference and possibly transfer metatarsalgia. The purpose of this study is to examine the effect of MIS HV on forefoot loading mechanics with respect to metatarsal shortening and sagittal plane displacement.

METHODS

Four lower-limb cadaveric specimens were studied. A pedobarography pressure-sensing mat was used to record forefoot plantar pressure in a controlled weight-bearing stance position. Control and postosteotomy measurements were obtained with the capital fragment fixated in 3 possible positions: 0 mm, 5 mm dorsal, and 5 mm plantar displacement. Pedobarography data yielded pressure data within measurable graphical depictions. Raw mean contact pressure measurements were taken under the first and fourth metatarsal heads to establish medial and lateral forefoot loading pressure ratios. An a priori power analysis was performed based on previous peer-reviewed pedobarographic data, and our study was adequately powered.

RESULTS

Around 40 measurements were recorded, and ratios of medial-to-lateral forefoot loading were constructed. Medial forefoot pressure control versus 0 mm displacement, and control versus dorsal displacement were not found to be statistically significant (p = 0.525, p = 0.55, respectively). Medial pressure significantly increased when comparing control versus plantar displacement (P = .006). Lateral pressure significantly increased with dorsal displacement of the osteotomy (P = .013).

CONCLUSION

Our study found that MIS HV correction did not cause an increase in lateral forefoot pressure loading when sagittal plane displacements were controlled. Plantar displacement increased medial loading, and dorsal displacement increased lateral loading. It may be valuable for surgeons to consider metatarsal head position postosteotomy, as a decrease in medial loading and subsequent increase in lateral loading may lead to lateral forefoot pain and transfer metatarsalgia.

LEVELS OF EVIDENCE

IV.

The surgical learning curve for percutaneous Zadek osteotomy for treatment of insertional achilles tendinopathy

INTRODUCTION

The Zadek Osteotomy has been described as an effective technique for the treatment of insertional Achilles tendinopathy. Recently, this strategy has been modified using minimally invasive techniques. A learning curve has been observed in many minimally invasive procedures in foot and ankle surgery. This retrospective study first intended to evaluate if there is a learning curve associated with the percutaneous Zadek Osteotomy. Further, if a learning curve was observed, we planned to assess the data for associated changes in complications and postoperative outcomes.

METHODS

A retrospective analysis of 98 patients who underwent percutaneous Zadek Osteotomy was performed. Patient charts were reviewed for operative times, complications, union rates, and Foot Function Index (FFI) and Visual Analogue Scale (VAS) scores. Analysis of variance was utilized to assess for differences between groups of cases.

RESULTS

Patients included 61 females and 37 males. Mean age was 51.28 ± 11.12 (range 28-81) years. Mean follow-up time was 42.07 ± 12.99 (range 24-65) months. Significant increases in operative times were observed in cases 1-14 when compared to cases 15-98 (p < 0.001). Improvements in FFI and VAS scores were observed at final follow-up within each case group (p < 0.001); there were no differences detected in FFI or VAS scores between groups of cases. There was no difference detected in number of complications between intervals of cases.

CONCLUSION

A learning curve was observed for the percutaneous Zadek Osteotomy, which was overcome around case 14. This learning curve was only observed in terms of procedure length. A surgeon's level of inexperience with the technique does not appear to affect functional outcomes, nonunion, or need for revision.

LEVEL OF EVIDENCE IV

Data will not be deposited in a repository.

A Joy-Stick Assistant Three-Dimensional Modified Technique of Minimally Invasive Surgery for Mild or Moderate Hallux Valgus

BACKGROUND

Minimally invasive surgery (MIS) such as minimally invasive chevron osteotomy and Akin osteotomy (MICA) has become popular in the treatment of hallux valgus. However, how to correct three-dimensional deformities in hallux valgus effectively and simply in MICA is still difficult. Special equipment is required in MICA as has been reported before. It is meaningful and necessary to reduce the reliance on special equipment in MICA.

METHODS

From January 2021 to July 2022, patients with mild or moderate hallux valgus were treated with a joy-stick assistant three-dimensional modified technique (Joy-stick 3D technique) of MIS. VAS, AOFAS Hallux MTP-IP scores, hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA) were measured pre- and postoperatively at the last follow-up of at least 6 months. Scores and radiologic angles were compared using paired sample t-test.

RESULTS

A total of 36 cases were included. HVA, IMA, and DMAA were (22.3 ± 6.1)°, (14.0 ± 3.2)°, and (8.9 ± 3.2)° preoperatively, and decreased to (7.0 ± 1.8)°, (3.7 ± 1.0)°, and (3.3 ± 1.1)° postoperatively. VAS decreased from 4.3 ± 1.7 to 0.7 ± 0.7. AOFAS Hallux MTP-IP scores improved from 68.6 ± 7.6 to 92.9 ± 6.1. Comparing mild and moderate cases, though HVA, IMA, and DMAA were significantly different preoperatively, the angles became statistically similar after surgery.

CONCLUSIONS

A joy-stick assistant three-dimensional modified technique is proposed to control the three-dimensional position of the metatarsal head and to reduce dependence on special tools. Mild and moderate hallux valgus deformities are effectively corrected using Joy-stick 3D technique.

Radiographic Comparison of Open and Minimally Invasive Distal Chevron Metatarsal Osteotomy in Patients With Hallux Valgus

This study aimed to compare radiographic outcomes of open and minimally invasive surgery (MIS) in patients with hallux valgus. We reviewed data of patients with hallux valgus who underwent open or minimally invasive distal chevron osteotomy at our institution. Radiographic assessment was completed preoperatively, immediate postoperatively, and one year postoperatively using eight weight bearing parameters . The classic distal chevron osteotomy method was used for open surgery and a modified method that added percutaneous K-wire fixation to the minimal invasive Chevron-Akin (third-generation MIS) was used for correction of the distal metatarsal articular angle (DMAA). A total of 65 feet (33 open surgeries and 32 MIS) were included. The HVA, IMA, and DMAA improved significantly following surgery regardless of surgical method (p<0.001). Other radiographic indicators showed no statistically significant differences after surgery. DMAA improved by 71.0±14.2% after surgery, and the open surgery group showed less significant reduction in DMAA (49.7±25.7%, p<0.001). Other parameters showed no difference between the two groups regarding relative postoperative changes. The MIS group showed shorter operation time (p<0.001) and hospitalization period (p=0.034) than did the open surgery group. Therefore, the MIS group is expected to be cost-effective. Radiographic measurements revealed comparable outcomes of MIS compared with open surgery. Additionally, adding percutaneous K-wire fixation during MIS had an advantage in correcting DMAA compared with open surgery. Furthermore, the correction of DMAA could reduce recurrence of valgus deformity of the hallux.

Variability in Surgical Case Volume Performed During ACGME-Accredited Orthopaedic Foot and Ankle Fellowship Training

INTRODUCTION

Previous studies have demonstrated a positive correlation between case volume and outcomes in foot and ankle surgery. This study elucidates surgical case volume benchmarks for Accreditation Council for Graduate Medical Education (ACGME)-accredited orthopaedic foot and ankle fellowship training in the United States.

METHODS

The ACGME provided case logs for orthopaedic residents and foot and ankle fellows (2018-2021). Variabilities in reported fellowship case volumes were defined as the fold-difference between 90th and 10th percentiles. Reported case volumes were compared between training cohorts with parametric tests.

RESULTS

Case logs from 65 orthopaedic foot and ankle fellows and 3146 orthopaedic residents were included. Fellows reported 1.3- to 1.5-fold more foot and ankle cases during fellowship training than during residency training (P < .001). On average, orthopaedic foot and ankle fellows reported 405.4 cases and most were arthrodesis (17%), forefoot reconstruction (17%), mid/hindfoot reconstruction (13%), tendon repair/transfer (12%), and trauma ankle hindfoot (11%). Case categories with the highest variabilities were amputation (14.8-fold difference), infection/tumor (11.6-fold difference), arthroscopy (9.2-fold difference), and calcaneus (8.7-fold difference).

DISCUSSION

Case volume benchmarks can assist trainees and faculty during orthopaedic foot and ankle training. More research is needed to determine case minimum requirements needed for autonomous practice in foot and ankle surgery.

LEVEL OF EVIDENCE

Level III.

Clinical guideline on the third generation minimally invasive surgery for hallux valgus

Minimally invasive surgery for hallux valgus correction, has been attracting great interests in the recent decades, due to the potential benefits of less pain, decreased recovery times, smaller scars with better cosmesis, and improved early post-operative range of motion. The most recent developments in minimally invasive surgery have evolved into the third generation with modifications of the chevron-type osteotomy. This evidence-based clinical guideline of the third generation minimally invasive surgery for hallux valgus is initiated and developed collectively by the Foot and Ankle Committee of Orthopedic Branch of Chinese Medical Doctor Association, Foot and Ankle Committee of Sports Medicine Branch of Chinese Medical Doctor Association, and Foot and Ankle Expert Committee of Orthopedic Branch of the Chinese Association of the Integrative Medicine. This clinical guideline provides recommendations for indications, contraindications, operative planning and techniques, post-operative management, management of complications, and prognosis of the third generation minimally invasive surgery for hallux valgus. The Translational Potential of this Article This comprehensive guideline aims to establish standardized recommendations for the indications, contraindications, operative techniques, and post-operative management of the third generation minimally invasive surgery for hallux valgus. By adhering to this guideline, the success rate of the procedure could be maximized. This comprehensive guideline serves as a valuable reference for practitioners interested in or preparing to perform minimally invasive surgery for hallux valgus.

Learning curve associated with minimally invasive surgery for hallux valgus: A systematic review

BACKGROUND

The purpose of this systematic review is to examine the learning curve associated with minimally invasive surgery (MIS) for the treatment of hallux valgus (HV).

METHODS

A systematic review was performed using PubMed, ScienceDirect, Web of Science, CINAHL and MEDLINE databases from database inception to February 16th, 2023. Inclusion criteria was articles with level of evidence I-III, any outcomes associated with learning curve, minimally invasive surgery, and diagnosis of hallux valgus' in adult patients.

RESULTS

Six articles out of 165 articles meet inclusion criteria. For all six articles, 368 total patients (422 total feet) were included in the study with an average age of 55.69 years. Three studies reported the number of surgeries needed to reach the plateau phase of the learning curve of MIS for HV, with a frequency weighted mean of 35.5 surgeries (range 27 - 40). In the selected articles, significant results were found for increased operating room (OR) time and fluoroscopy shots in the learning phase. There was no significant increase in complications in the learning phase. There was no significant decrease in patient outcomes, or the quality of correction performed during the learning phase.

CONCLUSION

An average of 35.5 surgeries (range 27 - 40) are needed to reach the plateau phase for MIS for HV. The learning phase of the learning curve of MIS for HV has a significant increase in OR time and fluoroscopy usage. However, the learning phase of the learning curve of MIS for HV is not associated with decreased outcomes or higher complication rates based on the small sample size in this study.

LEVEL OF EVIDENCE

Level III, Systematic Review.

Minimally Invasive Transverse Distal Metatarsal Osteotomy (MITO) for Hallux Valgus Correction: Early Outcomes of Mild to Moderate vs Severe Deformities

BACKGROUND

We compared the radiological and clinical outcomes of mild to moderate and severe hallux valgus (HV) treated with minimally invasive distal metatarsal transverse osteotomy (MITO) performed by a single surgeon.

METHODS

Eighty-four patients who underwent MITO between May 2018 and March 2020 were recruited and followed for at least 24 months. The severe group was defined as having a preoperative hallux valgus angle (HVA) >40 degrees or preoperative first-to-second intermetatarsal angle (1-2 IMA) >16 degrees; the mild to moderate group was defined as having an HVA <40 degrees and a 1-2 IMA <16 degrees. Pre- and postoperative measurements of the HVA, 1-2 IMA, distal metatarsal articular angle, and tibial sesamoid position were obtained. The visual analog scale for pain, the Foot and Ankle Outcome Score, and the Medical Outcomes Study Short Form Health Survey-36 physical component summary were used to assess clinical outcomes.

RESULTS

A total of 116 feet were included in this study and median follow-up period of 29.0 months (range, 24-52 months). Both groups showed significant improvements in all radiologic parameters postoperatively, with the degrees of correction greater in the severe group than in the mild to moderate group. All clinical scores improved significantly from the preoperative to the last follow-up visit. Final clinical outcomes and degrees of improvement were comparable in both groups.

CONCLUSION

This study showed that short-term radiographic results for patients with either mild to moderate or severe HV treated with MITO were favorable. Overall clinical outcomes were comparable to those of conventional treatments. In this series, we found MITO with screw fixation to be a satisfactory surgical option for patients with mild to severe HV deformities.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Minimally invasive Chevron Akin (MICA) osteotomy for severe hallux valgus

INTRODUCTION

The minimally invasive Chevron Akin (MICA) osteotomy has been widely used to treat hallux valgus (HV). The purpose of this study was to present a case series of patients with severe HV undergoing surgical treatment using the MICA procedure and to evaluate the clinical and radiographic outcomes.

MATERIALS AND METHODS

Retrospective study including 60 consecutive feet (52 patients) undergoing MICA for severe HV. The data were collected pre- and post-operatively at the last follow-up. Patients were clinically evaluated by the visual analog pain scale (VAS) and AOFAS hallux MTP-IP score. Radiographic assessments included measurements of hallux valgus angle (HVA), intermetatarsal angle (IMA), metatarsal (MT) length, distal metatarsal articular angle (DMAA), and plantar translation of MT head. The complications were recorded during the follow-up.

RESULTS

The mean age was 59.9 years, and the mean follow-up was 20.5 months. The average AOFAS increased from 41.2 to 90.9 points, and the VAS from 8.1 to 1.3 at the last follow-up. The average HVA decreased from 41.2º to 11.6º, the IMA from 17.1º to 6.9º, and the DMAA from 17.9º to 7.8º. The average shortening of the first metatarsal and the plantar translation of the MT head was 5.1 mm and 2.8 mm, respectively. The most observed complication was hardware discomfort, observed in 5 feet (8.3%). There were two cases of recurrence (3.3%).

CONCLUSION

MICA technique was demonstrated in this series of cases to be an effective procedure for severe HV, with a low rate of recurrence and an acceptable rate of complications.

LEVEL OF EVIDENCE

IV; case series.

Learning curve in relation to radiation exposure, procedure duration and complications rate for Minimally Invasive Chevron Akin (MICA) osteotomy

BACKGROUND

Minimally invasive chevron Akin osteotomy (MICA) has become increasingly common and is compatible with the traditional open approaches for hallux valgus correction. However, it is impeded by concerns regarding the steep learning curve, increased radiation exposure and some specific complications. No standardized method for identifying a learning curve exists. We used a reproducible mathematical model to accurately define the learning curve of MICA with a focus on fluoroscopy time, procedure duration and complications rate.

METHODS

We conducted a retrospective study of MICA procedure performed by a single surgeon during his initial experience with this procedure. The chronologic case number was plotted against variables of interest and learning was identified as the point at which instantaneous rate of change of a curve fit to the data set equalled the average rate of change of the data set.

RESULTS

One hundred cases have been analysed. Learning plateau in operation time was achieved after 29 cases, with the first 29 cases requiring a median of 60 min compared to 40 min for the latter 71 cases. Proficiency in fluoroscopy application occurred in case 30. The median fluoroscopy time for the first 30 cases was 86 seconds compared to 70 seconds in another 70 cases. The complication rate plateau was reached after 42 cases, with 15 of 22 complications occurring in the group operated first.

CONCLUSION

Results demonstrate surgeon's comfort with MICA to minimize operative time and radiation exposure after 30 cases. The plateau is achieved later for complications. Findings impose lag between surgeon feeling comfortable with procedure and a decrease in complications. Further research is reasonable to analyse several surgeons learning curve and to generate a potential reference learning curve that could serve as a normative.

TRIAL REGISTRATION

UKC-MB-KME-33/19, retrospectively registered.

Third-Generation Minimally Invasive Chevron Akin Osteotomy for Hallux Valgus: Three-Year Outcomes

Introduction

Numerous minimally invasive techniques have been developed for Hallux Valgus in recent years. Third-generation Minimally Invasive Chevron Akin (MICA) osteotomy has shown promising early results, but longer-term follow-up is required to assess whether patient clinical and radiological improvement is sustained. This cohort study presents three-year follow-up outcomes for patients of a single surgeon case series.

Methods

Thirty-three patients underwent third-generation MICA surgery between 2017 and 2018. Patient clinical-reported outcome measures included American Orthopaedic Foot & Ankle Society (AOFAS), Manchester-Oxford Foot Questionnaire (MOXFQ) scores, and Coughlin satisfaction. Radiographic outcomes were evaluated after a period of three years using hallux valgus angle (HVA) and inter-metatarsal angle (IMA), and compared to pre- and early post-operative outcomes.

Results

At 36 months, mean AOFAS scores improved from 48.2 to 95.6, mean MOXFQ scores improved from 57.6 to 6.7. Using the Coughlin scale, 81.8% of patients rated their outcome as 'Excellent' and 18.2% as 'Good'. Radiographic outcomes showed HVA and mean IMA decreased from 34.6 degrees to 16.0 degrees and from 13.1 to 6.1, respectively at 36 months.

Conclusion

Third-generation MICA demonstrates promising patient satisfaction scores post-operatively, and we have shown these improvements are sustained over a minimum three-year follow-up period.

Level of Evidence

Level IV, case series.

Does Minimally Invasive Surgery Provide Better Clinical or Radiographic Outcomes Than Open Surgery in the Treatment of Hallux Valgus Deformity? A Systematic Review and Meta-analysis

BACKGROUND

Hallux valgus is the most common foot deformity and affects 23% to 35% of the general population. More than 150 different techniques have been described for surgical correction. Recently, there has been increasing interest in the use of minimally invasive surgery to correct hallux valgus deformities. A variety of studies have been published with differing outcomes regarding minimally invasive surgery. However, most studies lack sufficient power and are small, making it difficult to draw adequate conclusions. A meta-analysis can therefore be helpful to evaluate and compare minimally invasive and open surgery.

QUESTIONS/PURPOSES

We performed a systematic review and meta-analysis of randomized controlled trials and prospective controlled studies to answer the following question: Compared with open surgery, does minimally invasive surgery for hallux valgus result in (1) improved American Orthopaedic Foot and Ankle Society (AOFAS) scores and VAS scores for pain, (2) improved radiologic outcomes, (3) fewer complications, or (4) a shorter duration of surgery?

METHODS

The systematic review and meta-analysis was conducted according to the guidelines of the Cochrane Handbook for Systematic Reviews of Intervention and the Preferred Reporting Items for Systematic Reviews and Meta-analyses. A search was performed in the PubMed, Embase, Scopus, CINAHL, and CENTRAL databases on May 3, 2022. Studies were eligible if they were randomized controlled or prospective controlled studies that compared minimally invasive surgery and open surgery to treat patients with hallux valgus. We defined minimally invasive surgery as surgery performed through the smallest incision required to perform the procedure accurately, with an incision length of approximately 2 cm at maximum. Open surgery, on the other hand, involves a larger incision and direct visualization of deeper structures. Seven studies (395 feet), consisting of six randomized controlled studies and one prospective comparative study, were included in the qualitative and quantitative data synthesis. There were no differences between the minimally invasive and open surgery groups regarding age, gender, or severity of hallux valgus deformity. Each included study was assessed for the risk of bias using the second version of the Cochrane tool for assessing the risk of bias in randomized trials or by using the Newcastle-Ottawa Scale for comparative studies. Most of the included studies had intermediate quality regarding the risk of bias. We excluded one study from our analysis because of its high risk of bias to avoid serious distortions in the meta-analysis. We performed a sensitivity analysis to confirm that our meta-analysis was robust by including only studies with a low risk of bias. The analyzed endpoints included the AOFAS score (range 0 to 100), where higher scores represent less pain and better function; the minimum clinically important difference on this scale was 29 points. In addition, the VAS score was analyzed, which is based on a pain rating scale (range 0 to 10), with higher scores representing greater pain. Radiologic outcomes included the hallux valgus angle, intermetatarsal angle, and distal metatarsal articular angle. Complications were qualitatively assessed and evaluated for differences. A random-effects model was used if substantial heterogeneity (I 2 > 50%) was found; otherwise, a fixed-effects model was used.

RESULTS

We found no clinically important difference between minimally invasive and open surgery in terms of the AOFAS score (88 ± 7 versus 85 ± 8, respectively; mean difference 4 points [95% CI 1 to 6]; p < 0.01). There were no differences between the minimally invasive and open surgery groups in terms of VAS scores (0 ± 0 versus 0 ± 1, respectively; standardized mean difference 0 points [95% CI -1 to 0]; p = 0.08). There were no differences between the minimally invasive and open surgery groups in terms of the hallux valgus angle (12° ± 4° versus 12° ± 4°; mean difference 0 points [95% CI -2 to 2]; p = 0.76). Radiographic measurements of the intermetatarsal angle did not differ between the minimally invasive and open surgery groups (7° ± 2° versus 7° ± 2°; mean difference 0 points [95% CI -1 to 1]; p = 0.69). In addition, there were no differences between the minimally invasive and open surgery groups in terms of the distal metatarsal articular angle (7° ± 4° versus 8° ± 4°; mean difference -1 point [95% CI -4 to 2]; p = 0.28). The qualitative analysis revealed no difference in the frequency or severity of complications between the minimally invasive and the open surgery groups. The minimally invasive and open surgery groups did not differ in terms of the duration of surgery (28 ± 8 minutes versus 40 ± 10 minutes; mean difference -12 minutes [95% CI -25 to 1]; p = 0.06).

CONCLUSION

This meta-analysis found that hallux valgus treated with minimally invasive surgery did not result in improved clinical or radiologic outcomes compared with open surgery. Methodologic shortcomings of the source studies in this meta-analysis likely inflated the apparent benefits of minimally invasive surgery, such that in reality it may be inferior to the traditional approach. Given the associated learning curves-during which patients may be harmed by surgeons who are gaining familiarity with a new technique-we are unable to recommend the minimally invasive approach over traditional approaches, in light of the absence of any clinically important benefits identified in this meta-analysis. Future research should ensure studies are methodologically robust using validated clinical and radiologic parameters, as well as patient-reported outcome measures, to assess the long-term outcomes of minimally invasive surgery.

Global research trends and hotspots analysis of hallux valgus: A bibliometric analysis from 2004 to 2021

Background

Hallux valgus (HV) is a common foot and ankle surgery disease. The correction of HV deformity relies on a highly challenging surgical treatment. Thus, widely adopted evidence-based clinical guidelines are still needed to guide the selection of the most appropriate interventions. Recently, the study of HV has been growing and scholars are increasingly paying particular attention to this area. However, bibliometric literature remains lacking. Therefore, this study aims to reveal the hotspots and future research trends in HV via bibliometric analysis to fill this knowledge gap.

Methods

Literature related to HV from 2004 to 2021 was retrieved from the Science Citation Index Expanded (SCI-expanded) of the Web of Science Core Collection (WoSCC). Quantitative and qualitative analyses of scientific data are performed using software such as CiteSpace, R-bibliometrix, and VOSviewer.

Results

A total of 1,904 records were identified for analysis. The United States had the most number of published articles and total citations. Thus, the United States has made an essential contribution to the field of HV. Meanwhile, La Trobe University in Australia was the most productive institution. Menz HB and Foot &amp; Ankle International were the most influential authors and the most popular journals among researchers, respectively. In addition, “older people,” “chevron osteotomy,” “Lapidus,” and “hallux rigidus” have always been the hotspots of attention. Changes and developments in the surgery of HV have gained researchers' interest. Future research trends are more focused on “radiographic measurement,” “recurrence,” “outcome,” “rotation,” “pronation,” and “minimally invasive surgery.” Thus, focusing on these subject directions can facilitate academic progress and provide the possibility of better treatments for HV.

Conclusion

This study summarizes the hotspots and trends in the field of HV from 2004 to 2021, which will provide researchers with an updated view of essential information and somehow guide future research.

Fourth-Generation Minimally Invasive Hallux Valgus Surgery With Metaphyseal Extra-Articular Transverse and Akin Osteotomy (META): 12 Month Clinical and Radiologic Results

BACKGROUND

Fourth-generation minimally invasive surgery (MIS) includes the multiplanar rotational deformity correction achieved through manipulation of an extra-articular distal first metatarsal osteotomy that is held with rigid fixation using 2 fully threaded screws, of which one must be bicortical to provide rotational and biomechanical stability. The aim of this study is to report the clinical and radiologic outcomes of an evolved fourth-generation MIS hallux valgus technique.

METHODS

A prospective single-surgeon series of consecutive patients undergoing fourth-generation MIS was performed using a distal transverse osteotomy with a minimum 12-month follow-up. The primary outcome was the Manchester-Oxford Foot Questionnaire (MOXFQ), a validated clinical patient-reported outcome measure (PROM). Secondary outcomes included radiographic deformity correction, clinical assessment, and EuroQol-5D-5L PROMs.

RESULTS

Between September 2019 and June 2021, 50 feet underwent fourth-generation MIS. The mean age was 55.8±15.3 years with a mean follow-up of 1.4 years. Preoperative and minimum 12-month primary outcome data were available for 100% of feet. There was a significant improvement in all MOXFQ domain scores, with the index domain improving from 53.4 to 13.1 (P < .001). There was a significant improvement (P < .001) in hallux valgus angle (32.7 to 7.9 degrees), intermetatarsal angle (14.0 to 4.2 degrees) and distal metatarsal articular angle (18.5 to 5.6 degrees). There was a significant improvement in general health-related quality of life EQ-5D-5L index and EQ-VAS scores (P < .05).

CONCLUSION

The fourth-generation MIS technique is a safe and effective approach to hallux valgus deformity correction with significant improvement in clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Level IV, prospective case series.

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

There is rapidly growing interest in minimally invasive surgery (MIS) of the foot and ankle. Technological advances, specifically with the advent of low-speed high-torque burrs, have enabled the expansion of MIS techniques. Accordingly, there is growing literature reporting excellent outcomes of MIS surgery to address many different pathologies of the foot and ankle. MIS techniques are particularly useful for conducting percutaneous osteotomies and bony débridement. These can be used to address bunion deformity, hammertoes, metatarsalgia, bunionette deformity, bone spurs, and hindfoot deformity. A detailed understanding of the technology, equipment, and techniques is crucial to safely conduct MIS of the foot and ankle. When done safely, MIS provides favorable outcomes with an expedited recovery and limited complications.

Five-Year Follow-up of Third-Generation Percutaneous Chevron and Akin Osteotomies (PECA) for Hallux Valgus

BACKGROUND

Recent large studies of third-generation minimally invasive hallux valgus surgery (MIS) have demonstrated significant improvement in clinical and radiologic outcomes. It remains unknown whether these clinical and radiologic outcomes are maintained in the medium to long term. The aim of this study was to investigate the minimum 5-year clinical and radiologic outcomes following third-generation MIS hallux valgus surgery in the hands of a high-volume MIS surgeon.

METHODS

A retrospective observational single highly experienced MIS surgeon case series of consecutive patients undergoing primary isolated third-generation percutaneous chevron and Akin osteotomies (PECA) for hallux valgus with a minimum 60-month clinical and radiographic follow-up. Primary outcome was radiographic assessment of the hallux valgus angle (HVA) and intermetatarsal angle (IMA) preoperatively, 6 months, and ≥60 months following PECA. Secondary outcomes included the Manchester-Oxford Foot Questionnaire, patient satisfaction, EuroQol-5D visual analog scale and the visual analog scale for pain.

RESULTS

Between 2012 and 2014, 126 consecutive feet underwent isolated third-generation PECA, with complete data available for 78 (61.9%) feet. The median follow-up was 65.0 (IQR 64-69; range 60-88) months. There was a significant improvement in radiographic deformity correction; the median IMA improved from 12.0 degrees (interquartile range [IQR]: 10.8-14.2) to 6.0 degrees (IQR: 4.2-7.3) (P < .001), and the median HVA improved from 27.2 degrees (IQR: 20.6-34.4) to 7.2 degrees (IQR: 3.4-11.6). Median MOXFQ Index score at ≥60-month follow-up was 2.3 (IQR: 0.0-7.8). The radiographic recurrence rate (defined as HVA >15 degrees) was 7.7% at final follow-up. The complication rate was 4.8%.

CONCLUSION

Radiologic deformity correction for the 78 feet we were able to follow that had third-generation PECA performed by a single highly experienced MIS surgeon was found to be maintained at a mean follow-up of average 66.8 months, with a radiographic recurrence rate of 7.7%. Clinical PROMs and patient satisfaction levels were high and comparable to other third-generation studies with shorter duration of follow-up.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

First metatarsal single-screw minimally invasive chevron-akin osteotomy: A cost effective and clinically reliable technique

Purpose

The common disease hallux valgus results in foot discomfort and dysfunction. Less soft tissue damage and faster wound healing have made minimally invasive surgery (MIS) more popular. However, little research has compared the fixation results of minimally invasive chevron-akin (MICA) osteotomy thus far. In this study, the clinical and radiographic results of MICA with first metatarsal single- or dual-screw fixation are being examined.

Methods

A total of 107 feet of 103 patients with mild to moderate symptomatic hallux valgus treated MICA from January 2018 to June 2020 were retrospective evaluated, with at least 12-months follow-up. 51 patients underwent single-screw fixation procedures and 52 patients received dual-screw fixation procedures. Patients were assessed preoperatively and at the final follow-up with radiographic measurements [hallux valgus angle (HVA), intermetatarsal angle (IMA) and distal metatarsal articular angle (DMAA)] and clinical scores (american orthopaedic foot and ankle society (AOFAS) forefoot score, visual analog scale (VAS) and Manchester-Oxford Foot Questionnaire (MOxFQ) scores). The coughlin satisfaction scores were also obtained.

Results

Both groups showed significantly improved HVA, IMA and DMAA at the final follow-up (P < 0.001). Regarding clinical outcomes, the AOFAS, VAS and MOxFQ in two categories also significantly improved postoperatively (P < 0.001). There was no obvious difference in the clinical and radiographic outcomes between the two groups (HVA, P = 0.833; IMA, P = 0.073; DMAA, P = 0.35; AOFAS, P = 0.48; VAS, P = 0.86; MOxFQ, P = 0.87). However, the single-screw fixation group showed significantly lower operation time and less number of intraoperative fluoroscopy (P < 0.001). No serious complications were observed in either group. The single-screw fixation technique saves at least $1,086 compared with the dual-screw group.

Conclusion

At the final follow-up, both the single- and dual-screw fixation groups had comparable good to excellent clinical and radiographic outcomes, as well as a similar incidence of complications. Additionally, the single-screw fixation group reduces overall surgical costs, number of intraoperative fluoroscopy and operational time.

Minimally Invasive Surgery Using a Shannon Burr for the Treatment of Hallux Valgus Deformity: A Systematic Review

Background

Recently there has been an increase in minimally invasive surgery (MIS) for the correction of hallux valgus deformity. This systematic review aims to evaluate and present the current literature on MIS hallux valgus correction in studies reporting the use of the Shannon burr with distal metatarsal osteotomies to help establish evidence-based guidelines for surgeons using this technique.

Methods

Two independent authors performed a systematic literature search using the following databases: PubMed, Embase, and the Cochrane library. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol and the Cochrane Handbook guidelines were followed. All studies included were published from 2008 to 2022 and included the use of the Shannon burr during distal metatarsal osteotomies MIS for hallux valgus and at least 12-month follow-up. The MINORS score criteria was used to evaluate the strength and quality of 17 studies by 3 authors. Statistical analysis and meta-analysis were not performed because of the heterogeneity of the included studies and the data being descriptive.

Results

A total of 17 studies were reviewed. A total of 911 subjects were included, and 1088 MIS procedures were performed. The average follow-up was 23.8 (12-59.1) months. American Orthopaedic Foot & Ankle Society scale and visual analog scale scores improved from 52.1 (41-62.5) to 90.3 (83.3-97.1) and 4.9 (3-8.2) to 0.8 (0-1.9). Satisfaction rates were very high among the studies that reported it. The hallux valgus angle, intermetatarsal angle, and distal metatarsal articular angle improved from 31.4 (23.5-44.1) to 11.1 (7-17.2), 13.4 (8.1-18.6) to 7.3 (4.2-10.3), and 12.3 (9-16.3) to 4.1 (1-6.7), respectively. The complication rate was 16.6%, and recurrence was 2.2%. Nonunion comprised 0.4%, infections 1.1%, nerve injury 2.2%, avascular necrosis 0%, hallux varus 0.09%, transfer metatarsalgia 0.1%, and hardware removal 6.2%.

Conclusion

MIS for the treatment of hallux valgus using the Shannon burr appears to be a safe and effective therapy, with appropriate correction of the hallux valgus deformity, improvement in functional outcomes, high patient satisfaction, low recurrence, and acceptable complication rates.

Level of Evidence

Level II, systematic review.

The Learning Curve of Third-Generation Percutaneous Chevron and Akin Osteotomy (PECA) for Hallux Valgus

The learning curve to reach technical proficiency for third-generation percutaneous or minimally invasive chevron and Akin osteotomies (PECA/MICA) is recognized to be steep however it is poorly defined in the literature. This study is a retrospective review of the first 58 consecutive PECA cases of a single surgeon. The primary outcome was the number of cases required to reach technical proficiency as defined by the operation time. Secondary outcomes included radiation exposure, radiographic deformity correction, and complication rates. Between November 2017 and March 2019, 61 consecutive PECA cases were performed with outcome data available for 58 of these (95%). Technical proficiency was reached after 38 cases. Operation time and radiation exposure significantly decreased after this transition point (p < .05). There was no difference in complication rate or radiographic deformity correction regardless of position along the learning curve (p > .05). In conclusion, the mean number of cases required to reach technical proficiency in third-generation PECA is 38 cases. The complication rate does not correlate to the number of cases performed, therefore surgeons interested in learning minimally invasive surgery can be reassured that there is unlikely to be an additional risk of harm to a patient during the learning curve.

The percutaneous learning curve of 3rd generation minimally-invasive Chevron and Akin osteotomy (MICA)

BACKGROUND

Minimally-invasive Chevron and Akin osteotomy (MICA) represents the third-generation percutaneous hallux valgus surgery which is characterized by an extra-articular osteotomy, stable internal fixation and a high potential for correction. Compared to other percutaneous techniques of the foot, MICA is generally regarded as an advanced and demanding surgical procedure with a flat learning curve. The aim of this study is to analyze a single-surgeons experience with his first 50 consecutive MICA procedures.

METHODS

Between May 2018 and February 2021, 50 consecutive MICA procedures performed by the author with the "K-wires-First technique" were prospectively analyzed focusing on surgery duration, number of fluoroscopies, correction results and surgery-associated complications. A modification of the original MICA technique as described by its inaugurators Redfern and Vernois allows the use of a standard-sized C-arm and aims to reduce revison rates and conversion to open surgery by placing the guidewires prior to performing the osteotomy.

RESULTS

The average surgery time for all MICA procedures was 46.8 min (SD 12.1, range 31-90 min). The average amount of fluoro shots required to perform MICA was n = 126.6 (SD 40.8, range 65-231). Comparing the preoperative and 6-week postoperative radiographs, the IMA decreased after MICA by a mean of 10.8° from 16.2° to 5.4° and the HVA by a mean of 22.1° from 30.6° to 8.5°. One case required intraoperative conversion to open hallux correction. There were 4 feet in three patients with secondary screw removal of the Chevron fixation due to prominent proximal screw tips.

CONCLUSIONS

Although the learning curve of 3rd generation MICA is flat and requires specific training and intensive practice, the rate of complications is not elevated compared to other percutaneous hallux valgus techniques. Strict adherence to the principles of 3rd generation MICA with stable fixation and meticulous intraoperative control of each surgical step helps to reduce surgery-associated complications. The learning curve showed a continous improvement in regard to surgery time and use of fluoroscopy. After 40 procedures, the surgery time consistently dropped under 45 min and required less than 100 fluoro-shots. The modified surgical technique may help reduce Chevron screw mal-positioning when using large C-arm fluoroscopy for this procedure.

Time to maximum clinical improvement following minimally invasive chevron and Akin osteotomies (MICA) in hallux valgus surgery

BACKGROUND

There is increasing evidence of positive improvement in clinical and radiological outcomes following minimally invasive hallux valgus deformity correction surgery (MIS). This study investigated the rate of improvement in clinical patient reported outcome measures (PROMs) following MIS as this is not well understood.

METHODS

Between July 2014 and July 2019, data was prospectively collected from consecutive patients pre-operatively and at 6, 12, and 24 months following third-generation minimally invasive chevron and Akin osteotomies (MICA). Radiographic deformity and correction was assessed using weight-bearing radiographs pre-operatively and 6 weeks post-operatively. The primary outcome measure was the change in Manchester Oxford Foot Questionnaire (MOXFQ) score at each time point. Secondary outcomes include radiographic deformity correction, health-related quality of life PROMs and exploration of cases where PROMs did not improve.

RESULTS

There were 202 feet with complete PROM data for every time point. There was a statistically significant improvement in MOXFQ Index score at each time point (p < 0.05) following MICA surgery. The majority of the improvement occurred within the first 6 months. A subgroup of 17 feet (8.4%) were identified which had worse MOXFQ Index scores 6 months following MICA. For 14 feet in this subgroup (82.4%), the MOXFQ Index score subsequently improved over time such that by two years, their score had significantly improved compared to their pre-operative score.

CONCLUSION

The majority of PROM improvement with MICA is gained by 6 months post-operatively but further significant improvement can be seen up to 2 years. Those patients who have not improved at 6 months, are likely to do so with time.

LEVEL OF EVIDENCE

IV.

Minimally Invasive Chevron-Akin for Correction of Moderate and Severe Hallux Valgus Deformities: Clinical and Radiologic Outcomes With a Minimum 2-Year Follow-up

BACKGROUND

The minimally invasive chevron-Akin (MICA) technique has already demonstrated efficacy compared with other known surgical treatments for mild to moderate hallux valgus (HV). MICA combines percutaneous osteotomies with the benefits of modern, rigid internal fixation. The aim of study was to evaluate the radiographic parameters, clinical improvement, and potential complications in moderate to severe HV cases, operated using the MICA technique.

METHODS

Retrospective study including 70 feet with HV operated using the MICA technique. The AOFAS hallux MTP-IP score and radiographics for HV evaluation were applied preoperatively, and after 6 months, 1 year, and 2 years of follow-up. The following radiographic parameters were measured: metatarsophalangeal hallux valgus angle (HVA), distal metatarsal articular angle (DMAA), interphalangeal angle (IPA), and intermetatarsal angle (IMA).

RESULTS

The average preoperative VAS pain score was 8.2 ± 1.5, which improved to 1.2 ± 2.2 at 24 months. The mean preoperative IMA was 14.8 ± 3.6 degrees compared with a mean of 7.5 ± 2.1 degrees (P < .01) at 24 months. The preoperative HVA value averaged 30.4 ± 9.8 degrees and at 6 months postoperatively 11.1 ± 6.8 degrees (P < .01), which remained stable until measured at 24 months. The mean preoperative DMAA was 16.3 ± 8.6 degrees and at the 6-month follow-up was 7.8 ± 5.4 degrees (P < .01). The mean preoperative IPA was 7.63 ± 4.4 degrees compared with a mean of 6.28 ± 3.5 degrees (P > .05) at 24 months. Complications included painful hardware (14.28%), neuropathic pain (2.85%), and loss of correction (4.28%).

CONCLUSION

In this retrospective review from a single center, we found the MICA technique to be an effective procedure for correcting moderate to severe HV, with a low rate of recurrence and an acceptable rate of complications. Patients undergoing the surgical procedure in our series showed a significant reduction in radiographic parameters and a significant improvement in clinical scores, maintaining these results over time.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Minimally invasive surgery for severe hallux valgus in 106 feet

BACKGROUND

There is widespread variation in the optimal procedure for correction of severe hallux valgus deformity defined as hallux valgus angle (HVA) (≥40°) and/or 1-2 intermetatarsal angle (IMA) (≥20°). There is limited evidence investigating the clinical or radiological outcomes following treatment of severe hallux valgus deformity with third-generation minimally invasive chevron and Akin osteotomies (MICA).

METHODS

This was a prospective observational single surgeon series of consecutive patients who underwent primary third-generation MICA with screw fixation for severe hallux valgus. The primary outcome was a validated patient reported outcome measure (PROM), the Manchester-Oxford Foot Questionnaire (MOXFQ), assessed minimum 2 years following MICA. Secondary outcomes were radiographic deformity correction (assessed 6 weeks post-operatively), complication rates and other quality of life PROMs (EQ-5D and Visual Analogue Pain Scale).

RESULTS

Between September 2014 and November 2018, 106 consecutive feet (n = 78 patients; 73 female, 5 male) met the inclusion criteria. Prospectively collected pre-operative and 2 year PROM MOXFQ data was available for 86 feet (81.1%). At two years following surgery, the MOXFQ score significantly improved for the Pain, Walking and Standing and Social Interaction domains from 39.2 to 7.5, 38.2 to 5.9 and 48.6 to 5.5, respectively (p < 0.001). Pre- and 6 week post-operative radiographic data was available for all 106 feet. Mean IMA improved from 18.2° to 6.3° (p < 0.001) whilst mean HVA improved from 45.3° to 10.9° (p < 0.001). The complication rate was 18.8% and the screw removal rate was 5.6%.

CONCLUSION

This study has demonstrated third-generation MICA for the treatment of severe hallux valgus deformity enables substantial deformity correction and is associated with significant improvements in clinical PROMs 2 years following surgery.

Minimally invasive hallux valgus correction with Internal Hallux Fixator® - A comparative cadaver study

BACKGROUND

The Internal Hallux Fixator® (IHF®; Waldemar Link, Hamburg, Germany) was designed for open surgical hallux valgus correction. It allows a defined lateralisation of the first metatarsal head after V-shaped, Chevron-like distal metatarsal osteotomy in order to correct mild to middle hallux valgus deformities. The intramedullary fixation provides dynamic compression of the osteotomy and thus postoperative full weight bearing mobilization is an integral part of the therapy. This comparative cadaver model study investigates the feasibility of implanting the device using a minimally invasive technique and compares its capability of first metatarsal head lateralisation to the established 3rd generation MICA (Minimally Invasive Chevron and Akin osteotomy) technique.

METHODS

16 fresh frozen cadaveric feet (8 left, 8 right) of 8 body donors received either MICA (Group 1), or an IHF® in a minimally invasive technique (Group 2). The achievable first metatarsal head lateralisation and operating time were measured and pitfalls recorded.

RESULTS

This cadaver model study confirmed, the minimally invasive implantation of the Internal Hallux Fixator® can be performed reliably via 10 mm mini incision with V-shaped distal metatarsal osteotomy. The mean first metatarsal head lateralisation was comparable between the groups with no statistically significant difference (7.2 (±1.9) mm in G1, or 8.3 (±0.8) mm in G2; p = 0.09). The IHF® was inserted and fixed in mean 3.7 (±0.6) min, whereas double screw fixation needed 10 (±3.7) min.

LEVEL OF CLINICAL EVIDENCE

5, Cadaver model study.

Minimally Invasive vs. Open Surgery for Hallux Valgus: A Meta-Analysis

Purpose

In recent years, minimally invasive surgery (MIS) for hallux valgus has emerged and gained popularity. To date, evidence on the benefits of MIS for hallux valgus is still controversial. This updated meta-analysis aimed to comprehensively evaluate the efficiency of MIS vs. open surgery for hallux valgus.

Methods

A systematic literature search of PubMed, Embase, and the Cochrane Library was performed. Two independent reviewers conducted data extraction and analyzed data with R software. Data were presented with risk ratio (RR) and standardized mean difference (SMD) along with 95% confidence interval (CI).

Results

A total of 22 studies in which there were 790 ft treated with the MIS procedure and 838 ft treated with an open procedure were included. The correction of sesamoid position was better in the MIS group. The post-operative distal metatarsal articular angle (DMAA) of the MIS group was lower. There was less pain at the early phase in the MIS group. The MIS group had a shorter surgery time and shorter hospitalization time compared with the open group. Our meta-analysis revealed no statistically significant difference in hallux valgus angle (HVA), first intermetatarsal angle (IMA), the first metatarsal shortening, the American Orthopedic Foot and Ankle Society (AOFAS) score, visual analog scale (VAS) score at the final follow-up or complication rate (when all studies were considered). When taking into consideration only randomized controlled trial (RCT), the AOFAS score was higher in the MIS group while HVA, IMA, DMAA, and complication rate remained no significance. Post-operative IMA of the MIS group was significantly lower when only studies reporting the second-generation (2G) MIS were included. When just studies adopting the third-generation (3G) MIS were included, the HVA and DMAA were lower in the MIS group.

Conclusion

The MIS procedures were more effective than open surgeries in the treatment of hallux valgus. Moreover, the MIS group achieved better radiologic and clinical outcomes compared with the open group.

Minimally invasive hallux valgus correction: Is it better than open surgery?

BACKGROUND

The aim was to compare the minimally invasive (MIS) chevron osteotomy to the well-established open chevron osteotomy for the correction of hallux valgus deformity.

METHODS

Two retrospective cohorts of patients treated with MIS or open chevron osteotomy for hallux valgus correction, matched for age and gender with a minimum follow up of six months were reviewed. Functional outcomes were evaluated using pre and post-operative Manchester Oxford Foot and Ankle Questionnaire (MOXFQ), Visual Analog Score (VAS) for pain and the Unified Elective Orthopaedic Score (UnEOS). Two independent, blinded examiners evaluated the radiographic correction of hallux valgus (HV) and intermetatarsal (IM) angle.

RESULTS

A Total of 54 cases (27 per study group) with a mean follow-up of 25.9 months were included in the study. Pre-operatively, VAS (p = 0.76) and MOXFQ (p = 0.46) scores and HV angle (p = 0.1) were comparable in both groups. However, IM angle was significantly larger in the MIS group (p = 0.005). Post-operatively there was significant improvement in VAS and MOXFQ scores as well as significant correction of the HV and IM angles (p < 0.0001) for both groups. Comparing the two procedures, there was no significant difference between groups for VAS (p = 0.34), MOXFQ scores (p = 0.56) and HV angles (p = 0.069) but the MIS technique was significantly better in improving the IM angle (p = 0.016). The post-operative UnEOS score and the Satisfaction UnEOS domain reached excellent levels for the entire cohort with no statistical difference between the two groups (p = 0.2 and 0.28 respectively).

CONCLUSION

Results show MIS chevron osteotomy provides better radiographic correction of the IM angle but functional outcomes for all parameters were comparable to the open technique. It can therefore be considered at least equivalent to standard open surgery when compared using validated Patient Reported Outcome Measures (PROMs).