Clinical and Radiographic Outcomes of Percutaneous Chevron-Akin Osteotomies for the Correction of Hallux Valgus Deformity

Minimally Invasive Forefoot Surgeries Using the Shannon Burr: A Comprehensive Review

Since the early 2000s, minimally invasive forefoot surgery (MIS), particularly hallux valgus correction, has significantly advanced with the introduction of the Shannon burr. However, despite numerous relevant studies being published, no comprehensive review articles have summarized MIS for various forefoot conditions. Therefore, in this comprehensive review, we examined the relevant studies about the application of MIS (excluding arthroscopy and endoscopy) for various forefoot conditions. Additionally, we discuss the essential considerations for achieving favorable surgical outcomes and preventing complications associated with each technique. We analyzed the characteristics of each surgical procedure and identified areas for future focus. Effective surgical treatment not only requires MIS, but also the appropriate selection of patients based on suitable indications and executing procedures within the surgeon's capabilities. We hope that this review will help readers to enhance their expertise in this field.

Biomechanical Evaluation of Fourth Generation Minimally Invasive Distal First Metatarsal Osteotomy-Akin Osteotomy Technique on First Ray Articular Contact Properties

BACKGROUND

Hallux valgus is a common deformity encountered but remains a complex clinical entity. Fourth-generation minimally invasive surgery (MIS) techniques consisting of a percutaneous distal metatarsal transverse osteotomy combined with an Akin osteotomy have been used to address mild to severe hallux valgus deformities. The benefits of an MIS approach include improved cosmesis, faster recovery, lower opiate requirement, immediate weightbearing, and favorable outcomes relative to a traditional, open procedure. An understudied area with respect to hallux valgus correction is the effect that osteotomies can have on the articular contact properties of the first ray following correction.

METHODS

Sixteen paired cadaveric specimens were dissected to include the first ray and tested in a customized apparatus. Specimens were randomized to receive a distal transverse osteotomy translated either 50% or 100% of the width of the first metatarsal shaft. The osteotomy was performed with either a 0° or 20° distal angulation of the burr relative to the shaft in the axial plane. Specimens were tested in the intact state and following the distal first metatarsal osteotomy for peak pressure, contact area, contact force and center of pressure at the first metatarsophalangeal (MTP) and first tarsometatarsal (TMT) joints. An Akin osteotomy was then performed on each specimen, and peak pressure, contact area, contact force, and center of pressure were recalculated.

RESULTS

There was a notable decrease in peak pressure, contact area, and contact force across the TMT joint with greater shifts of the capital fragment. However, at 100% translation of the capital fragment, distal angulation of the osteotomy by 20° appears to improve loading across the TMT joint. Addition of the Akin osteotomy at 100% translation also aids in increasing the contact force across the TMT joint. The MTP joint is less sensitive to changes in shifts and angulation of the capital fragment. The Akin osteotomy also leads to increased contact force across the MTP joint when the capital fragment is translated 100%.

CONCLUSION

While the clinical significance is unknown, larger shifts of the capital fragment lead to greater load alterations at the level of the TMT joint than the MTP joint. Distal angulation of the capital fragment and the addition of an Akin osteotomy can aid in reducing the size of those changes. The Akin can lead to increased contact forces at the MTP joint with 100% translation of the capital fragment.

LEVEL OF EVIDENCE

Not applicable, Biomechanical study.

Early Outcomes of Third-Generation Minimally Invasive Chevron-Akin (MICA) Osteotomy for Symptomatic Hallux Valgus Deformity

Hallux valgus is a common progressive forefoot deformity. Although open techniques have shown good outcomes, no technique has been shown to be superior to other techniques. The current third generation of minimally invasive Chevron-Akin (MICA) technique features a percutaneous procedure with a stable internal fixation. The technique used in this study resulted in stable internal fixation; however, 1 screw was used in intramedullary fashion in the majority of cases. The purpose of this study is to review the early outcomes of MICA. Electronic Health Records (EHR) were queried for patients who underwent MICA to treat hallux valgus (HV) deformity, by a single surgeon. The primary clinical outcomes assessed were visual analog pain score (VAS), rate of revision surgery, and recurrence. Radiographic outcomes were assessed including pre and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), and bony foot width. The secondary outcomes included postoperative complications. A total of 91 feet underwent MICA to correct symptomatic HV deformity. The mean age of this cohort was 53.63 ± 15.42 years, mean body mass index (BMI) of 26.81 ± 6.21 kg/m2, mean follow-up of 6.33 ± 6.39 months and 87 feet belonged to female patients. Patients showed significant improvement in VAS and radiographic outcomes at final follow-up, with a mean improvement of 10.70° ± 6.42°, 2.39° ± 3.55°, and 5.30 mm ± 4.23 mm for the HVA, IMA, and bony foot width, respectively. Two patients (2.2%) required revision surgery for nonunion and removal of symptomatic hardware. One patient had a second metatarsal fracture treated nonoperatively. No feet had recurrence, hardware loosening, infection, or scar hypersensitivity. The current study reported on early outcomes for MICA. This technique appears to be effective and safe with no failure of fixation in our patients. We showed in our short-term follow-up, MICA led to significant improvement in pain and radiographic scores.Levels of Evidence: III, retrospective study.

Outcome comparison of minimally invasive proximal and distal chevron Akin osteotomies in patients with severe hallux valgus deformity: A randomized prospective study

PURPOSE

To date, the surgical treatment of severe hallux valgus deformity remains challenging despite the various methods presented. This study aimed to compare the effectiveness of minimally invasive distal chevron Akin osteotomies (d-MICA) and minimally invasive proximal chevron Akin osteotomies (p-MICA) in correcting severe hallux valgus deformities.

METHODS

This prospective follow-up study included patients randomly assigned to undergo p-MICA or d-MICA for hallux valgus deformities with a preoperative hallux valgus angle (HVA) ≥ 40° and/or a first to second intermetatarsal angle (IMA) ≥ 16°. After a minimum follow-up period of two years, we compared various clinico-radiographic parameters of patients whose HVA exceeded 15° at the final follow-up.

RESULTS

In the p-MICA and d-MICA groups, seven of 40 cases (17.5%) and 16 of 41 cases (39.0%), respectively, exhibited HVA > 15° at the final follow-up (P = 0.048). The preoperative parameters showed no significant differences. However, at the first weight-bearing assessment, the HVA, IMA, and relative second metatarsal length were significantly smaller, and the distal metatarsal articular angle (DMAA) was greater in the p-MICA group (all P < 0.05) compared with the d-MICA group. Postoperatively, both groups exhibited significant decreases in HVA and IMA at the final follow-up (P < 0.001 for all parameters). The p-MICA group showed no significant changes in DMAA and the relative length of the second metatarsal (P = 0.253 and 0.185, respectively). However, the d-MICA group showed a significant decrease in DMAA (P < 0.001) and an increase in the relative length of the second metatarsal at the final follow-up (P = 0.01).

CONCLUSIONS

p-MICA and d-MICA procedures demonstrated effective correction potential for severe hallux valgus deformities; however, the d-MICA procedure exhibited a notably higher incidence of unsatisfactory correction at the final follow-up than p-MICA. Therefore, d-MICA may be less predictable in achieving successful outcomes than p-MICA in treating severe hallux valgus deformities.

Racial Disparities in Outcomes After Foot and Ankle Surgery: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis delved into the impact of race and ethnicity on outcomes following foot and ankle surgery, an area garnering increasing attention within the medical community. Despite significant literature on postsurgical clinical and functional outcomes, limited research has explored the influence of racial and ethnic factors on postoperative outcomes. In this study, data from 33 relevant studies, involving a total of 557,734 patients, were analyzed to assess outcomes across different racial and ethnic groups. Notably, only 6 studies met the criteria for inclusion in the final meta-analysis due to variations in outcome reporting. Findings revealed disparities in functional scores, pain levels, and resource utilization among different racial and ethnic cohorts. Specifically, non-White and minority patients exhibited higher rates of foot and ankle fractures and lower extremity surgeries, worse functional outcomes, increased pain, longer hospital stays, and a greater incidence of complications compared to their White counterparts. However, some studies presented contradictory results, emphasizing the necessity for further investigation to elucidate these discrepancies fully. This research underscores the importance of considering racial and ethnic factors in foot and ankle surgery outcomes and highlights the need for targeted interventions to address existing disparities.

Minimally invasive Chevron-Akin (MICA) osteotomies without Akin fixation in hallux valgus correction: a case series with 2-year follow-up

PURPOSE

The minimally invasive Chevron-Akin (MICA) is considered the third generation of minimally invasive hallux valgus (HV) surgery, and its original description included fixation of the Akin osteotomy with a screw. The aim of this study is to evaluate a series of patients undergoing HV correction using the MICA technique without screw fixation of the Akin osteotomy.

METHODS

We retrospectively evaluated 58 consecutive patients who underwent surgical correction for HV between August 2018 and March 2020. A total of 69 feet were evaluated with a minimum follow-up of 2 years. Clinical outcomes such as pain (VAS), function (AOFAS), range of movement, criteria personal satisfaction and complications were evaluated.

RESULTS

The AOFAS score (mean ± standard deviation) significantly improved from 57.0 ± 8.6 preoperatively to 93.9 ± 8.7 postoperatively (p < .001) with a minimum follow-up of 2 years. The VAS score improved from 6.0 ± 1.8 preoperatively to 0.6 ± 1.4 at 2-year follow-up (p < .001), and the hallux valgus angle reduced from 39.7 ± 6.9 to 8.9 ± 9.0 (p < .001). The majority of patients (95.6%) reported the result as excellent or good, and the most common complication was the need to remove the screw (7.2%).

CONCLUSIONS

The use of MICA without Akin osteotomy fixation resulted in successful correction of hallux valgus with improvements in clinical and radiographic parameters.

LEVEL OF EVIDENCE

IV, case series.

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

Background

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

Methods

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

Results

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

Conclusion

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

Level of Evidence

Level III, retrospective cohort study.

Fracturing the Lateral Hinge Improves Radiographic Alignment and Does Not Affect Clinical Outcomes of the Minimally Invasive Akin Osteotomy

BACKGROUND

Intraoperative fracture of the lateral cortex is common during Akin osteotomy. In a recent study, lateral cortex fracture did not impede healing or result in loss of correction in a combined cohort of open and percutaneous osteotomies stabilized by K-wire fixation. We hypothesize that undesired lateral cortex fracture will not affect radiographic correction and patient-reported outcomes in a percutaneous cohort stabilized by permanent, rigid screw fixation.

METHODS

Consecutive patients with hallux valgus who underwent first metatarsal osteotomy and percutaneous Akin osteotomy stabilized by permanent, rigid screw fixation between May 2020 and January 2022 were retrospectively reviewed. Patients were stratified based on fractured lateral cortex (FC) or its absence (nonfractured cortex [NFC]). Visual analog scale (VAS) and Foot Function Index (FFI) were used to assess pain and patient-reported outcomes at 1-year follow-up. Patients were polled for satisfaction at 1-year follow-up by yes/no survey.

RESULTS

Ninety-eight patients (89% female) were reviewed (98 feet; 43 NFC, 55 FC). Mean age was 48.3 years (range, 18-83 years). Mean preoperative VAS score was 7.5 and 7.7 in NFC and FC groups, which significantly decreased to 0.6 (P < .01) and 0.6 (P < .01), respectively. Mean total FFI was 53.9 and 54.2 and decreased to 17.9 (P < .01) and 17.2 (P < .01) in the NFC group and FC group, respectively. Overall, 97.8% of the NFC group and 96.4% of the FC group reported satisfaction.Mean HVA improved from 27.2 (16-42) degrees to 10.7 degrees (4-12) postoperatively in the NFC group. And in the FC group, HVA improved from 29.3 (19-39) degrees to 7.1 (4-12) degrees postoperatively. Postoperative HVA was significantly lower in the FC group (P < .05).

CONCLUSION

In an exclusively percutaneous surgical cohort with correction maintained by rigid screw fixation, fracture of the lateral cortex is associated with improved postoperative radiologic alignment without detriment to patient-reported outcomes.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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.

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.

Sesamoid Position Change Over 2 Years After Distal Chevron Osteotomy for Moderate to Severe Hallux Valgus: A Prospective Cohort Study

BACKGROUND

Sesamoid position change after distal chevron osteotomy for moderate to severe hallux valgus is not well known in the literature. The objective of this study was to determine whether the sesamoid position changed over 2 years after distal chevron osteotomy for moderate to severe hallux valgus.

METHODS

Ninety-seven patients who underwent distal chevron osteotomy for moderate to severe hallux valgus were prospectively assessed for 2 years. There were 91 females, and the mean age was 54.9 (SD 10.9) years. The Self-Reported Foot and Ankle Score (SEFAS) was used for functional assessment. Foot pain was assessed by a 0-10 visual analog scale (VAS), and patient satisfaction by a 5-point Likert scale. Radiologically, hallux valgus angle (HVA), first-second intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), metatarsal head displacement, and sesamoid position by the AOFAS criteria were analyzed. Patients were classified according to the medial sesamoid position on the first postoperative weightbearing radiograph (1º-WB-Xray) into the reduced sesamoid group (66 patients) and nonreduced sesamoid group (31 patients).

RESULTS

All patients were assessed preoperatively and postoperatively at 1 month and 2 years. On the 1º-WB-Xray, IMA was significantly lower in the reduced group (P = .038), but HVA (P = .063) and DMAA (P = .246) were not significantly different. At the final follow-up, no patients in the reduced group had sesamoid position change from 1º-WB-Xray, whereas 8 (25.8%) patients in the nonreduced group had change of their sesamoid positions. The SEFAS was not significantly different between groups preoperatively (P = .386) or at 1 month postoperation (P = .064). The final SEFAS, VAS pain, and satisfaction scores were significantly better in the reduced group, although the clinical significance of these changes remains unknown.

CONCLUSION

A nonreduced position of the sesamoids obtained in surgery can cause their increased malposition over 2 postoperative years and statistically less functional outcomes.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

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.

Clinical and Radiographic Outcomes of Percutaneous Third-Generation Double First Metatarsal Osteotomy Combined With Closing-Wedge Proximal Phalangeal Osteotomy for Moderate and Severe Hallux Valgus

BACKGROUND

The treatment for severe hallux valgus deformity presents a challenge with high risk of complications. Third generation MIS techniques have increased their publications in recent years. The aim was to compare clinical and radiologic outcomes in moderate and severe cases and report minor and major complications.

METHODS

Retrospective series of cases with prospective data collection of 156 consecutive feet that underwent percutaneous double first metatarsal osteotomy (PEDO) and first phalanx osteotomy between 2008 and 2019 for moderate (hallux valgus angle [HVA] between ≥20 and <40 degrees and/or intermetatarsal angle [IMA] <16 degrees) and severe (HVA ≥40 degrees and/or IMA ≥16 degrees) hallux valgus deformities. Primary outcomes included radiographic and clinical parameters. Secondary outcomes included minor and major complications.

RESULTS

A total of 156 procedures were performed in 128 patients. Mean age was 54.3 years (SD 14.3) (range, 19-82 years), median follow-up was 22.6 months (range, 12-96 months). Radiographic changes pre- to postoperation were as follows: HVA changed from 38.2 (SD 10.1) degrees to 11.2 (SD 8.3) degrees (P < .001), IMA from 14.7 (SD 3.2) degrees to 7.9 (SD 3.7) degrees (P < .001), and distal articular metatarsal angle from 19.7 (SD 6.3) degrees to 8.8 (SD 5.7) degrees (P < .001) after PEDO technique. Clinical changes pre- to postoperation were as follows: American Orthopaedic Foot & Ankle Society ankle-hindfoot scale scores improved from 47.3 (SD 16.5) to 87 (SD 11.6) (P < .001) and visual analog scale scores from 5 (2.7) to 0.9 (1.3) (P < .001). The satisfaction rate was 97% in the total sample. Recurrence rate (HVA ≥20 degrees) was 7.7%. Hallux varus (HVA <0 degrees) occurred in 5.8%, acute osteomyelitis in 1.3%, partial avascular necrosis in 0.6%, screw removal in 0.6%, and reoperation in 1.9%. No nonunion was observed.

CONCLUSION

Clinical and radiographic parameters improved significantly, with a minimum of 12 months of follow-up in moderate and severe hallux valgus. Long experience in percutaneous surgery and specific instruments are needed for this technique. Recurrence was linked to preoperative HVA ≥40 degrees and postoperative tibial sesamoid position; Hallux varus was linked to lateral soft tissue release.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Valgus Second Toe Deformity Treated With a Percutaneous Extracapsular Closing-Wedge Osteotomy of the Proximal Phalanx

BACKGROUND

Coronal and sagittal plane deformities of the lesser toes are common yet challenging to treat. Traditional open releases and translational Weil osteotomies can be unpredictable and lead to postoperative stiffness. We present the results of a percutaneous closing wedge extracapsular osteotomy of the proximal phalanx to treat valgus deformity of the second toe.

METHODS

Thirty-one patients underwent 40 percutaneous osteotomies at a median age of 58.6±9.4 years. Using a small dorsomedial incision, a percutaneous proximal metaphyseal medial closing-wedge extracapsular osteotomy of the second toe is performed, leaving the dorsolateral cortex intact. An irrigated low-speed, high-torque 2- × 8-mm burr is used under image guidance. The osteotomy is then closed to correct deformity and taped for 2 weeks. Patient-reported outcomes and weightbearing radiographs were obtained.

RESULTS

Questionnaire data was available for 89.7% (n=35) of cases. Most cases (91.4%) were either satisfied or extremely satisfied with the procedure. Radiographs were available for 90.0% of osteotomies, with a median length from surgery to radiographic follow-up of 1.6 years (range 0.5-6.3; SD ±1.5). Median second-toe valgus angle (STVA) decreased from 16.2±10.7 degrees to 5.0±7.0 degrees (P < .001) at final follow-up. All osteotomies united with no delayed union. There were no wound complications or infections. We found 2 cases of radiographic recurrence.

CONCLUSION

Percutaneous proximal phalanx base metaphyseal closing wedge extracapsular osteotomies of lesser toes to correct coronal plane deformity is useful adjunct to first-ray corrective surgery and is associated with high levels of patient satisfaction.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Quality of MIS vs Open Joint Preparations of the Foot and Ankle

BACKGROUND

Minimally invasive surgery (MIS) is growing in the field of foot and ankle, and the MIS burr is an emerging tool. Although commonly used to perform osteotomies, the burr can also be used for arthrodesis joint preparation that traditionally would be performed through open incisions. To date, there is no study comparing the quality of joint preparation between using a fluoroscopy-guided MIS technique compared to traditional open techniques. The goal of this cadaveric study is to compare the percentage of joint surfaces prepared between MIS and open techniques for the most common joints that are fused in foot and ankle surgery.

METHODS

Open joint preparation was performed under direct visualization with open incisions. MIS joint preparation was performed percutaneously using fluoroscopic guidance alone, without arthroscopy. After joint preparation, cadaveric samples were disarticulated, and joint surfaces were analyzed for percentage of cartilaginous surface removed. The percentage of joint surface prepared was compared between the open and MIS techniques.

RESULTS

Ten cadaveric samples were used for the MIS technique and 5 samples for the open technique. Percentage of joint surface prepared was similar for all joint surfaces.

CONCLUSION

The MIS technique in the hands of experienced surgeons was found to provide overall similar percentages of surface area prepared compared to traditional open techniques.

CLINICAL RELEVANCE

MIS joint preparation may be useful for specific patient populations. This study suggests that MIS joint preparation is a reasonable, and possibly advantageous, alternative to open preparation in arthrodesis surgery when performed by experienced MIS surgeons.

Early Radiographic Outcomes of Minimally Invasive Chevron Bunionectomy Compared to the Modified Lapidus Procedure

Background

Minimally invasive (MIS) bunion surgery has become increasingly popular. Although early reports on outcomes have been encouraging, no study to date has compared outcomes from the MIS chevron and Akin procedures to the modified Lapidus procedure. Our primary aim was to compare early radiographic outcomes of the MIS chevron and Akin osteotomies to those of the modified Lapidus procedure in patients with comparable deformities, and secondarily to compare clinical outcomes.

Methods

Patients were retrospectively reviewed for inclusion from a prospectively collected foot and ankle registry. Patients were eligible if they underwent either the MIS bunionectomy or modified Lapidus procedure and had preoperative and minimum 5-month postoperative weightbearing radiographs. Forty-one patients who underwent MIS bunionectomy were matched to 41 patients who underwent Lapidus bunionectomy based on radiographic parameters. Demographics, radiographic parameters, complications, reoperations, and PROMIS scores were compared between groups.

Results

Both groups achieved similar radiographic correction. There was no significant difference in pre- or postoperative PROMIS scores between groups. Procedure duration was significantly faster in the MIS group (P < .001). Bunion recurrence (hallux valgus angle ≥20 degrees) occurred in 1 MIS patient and 2 Lapidus patients, with all patients asymptomatic. The most common reason for reoperation was removal of hardware (4 patients in the MIS group, 2 patients in the Lapidus group).

Conclusion

This is the first study to our knowledge to compare early radiographic outcomes between MIS bunionectomy and the modified Lapidus procedure in patients matched for bunion severity. We found that patients with similar preoperative deformities experience similar radiographic correction following MIS chevron and Akin osteotomies vs modified Lapidus bunionectomy. Further research is needed to investigate satisfaction differences between the procedures, longer-term outcomes, and which deformities are best suited to each procedure.

Level of Evidence

Level III, Retrospective case control study.

Radiographic and clinical outcomes of minimally invasive surgery versus open osteotomies for the correction of hallux valgus

PURPOSE

Hallux valgus is a common disease which causes pain and dysfunction of the foot. Although numerous methods of procedures have been introduced, a single procedure cannot correct all deformities of hallux valgus. The study aims to evaluate the radiographic and clinical effectiveness of a new minimally invasive surgery (MIS) versus open Chevron-Akin procedures.

METHODS

This was a retrospective comparative study. Data were collected from May 2018 to January 2020. A total of 27 patients (31 feet) undergoing MIS for hallux valgus were included in this study. The average age of patients underwent MIS was 59.9 years. The mean follow-up was 25.1 months. Open osteotomies were performed in 30 patients (31 feet) during the same period. The mean age of these patients at the time of surgery was 59.1 years. The mean follow-up was 26.1 months. Pre-operative and post-operative radiographic outcome measures included HVA, IMA, DMAA, the Sgarlato's angle and the length of the first metatarsal, and distance between the dorsal cortex of first and second metatarsal necks. The AOFAS and VAS were used to assess foot function.

RESULTS

The preoperative HVA in MIS group and open group were 34.8° and 33.1° respectively. The post-operative HVA were 20.4° and 13.7°. The pre-operative IMA in MIS group and open group were 13.0° and 12.1°. The post-operative IMA were 11.4° and 5.5° respectively. The pre-operative DMAA were 14.8° and 15.1° respectively. The post-operative DMAA were 6.3° and 8.7°. The AOFAS increased from 44.0 to 90.2 in MIS group and from 47.6 to 89.5 in open group. The VAS decreased from 7.3 to 1.3 in MIS group and from 7.1 to 1.2 in open group.

CONCLUSION

Although open osteotomies were superior than MIS in HVA and IMA, MIS showed advantages in correcting DMAA. MIS provided equivalent functional outcomes compared to open surgery.