Third-Generation Minimally Invasive Chevron-Akin Osteotomy for Hallux Valgus Produces Similar Clinical and Radiological Outcomes as Scarf-Akin Osteotomy at 2 Years: A Matched Cohort Study

Biomechanical Consequences of Proximal Screw Placement in Minimally Invasive Surgery for Hallux Valgus Correction

Hallux valgus is one of the most common surgically corrected forefoot deformities. Studies evaluating clinical outcomes of minimally invasive chevron and akin (MICA) procedure have shown shorter operation time, faster recovery, and smaller scars compared to the open approach. Previous biomechanical cadaveric studies have largely focused on the open approach with minimal on MICA. To our knowledge, no studies have compared different proximal screw placements in MICA which can either be three-point fixation or intramedullary. This study aims to compare the biomechanical properties of fixation between these 2 techniques in MICA. Six matched pairs of human fresh frozen cadaveric feet were randomized to either 3-point fixation or intramedullary groups. Both procedures were performed by a single fellowship-trained orthopedic foot and ankle surgeon. Using a material testing machine, each specimen underwent 1000 cycles of plantar-to-dorsal uniaxial loads from 0 to 31 N in cantilever configuration while monitoring bending stiffness and distal fragment dorsal angulation. They were then subjected to load until failure at a compression rate of 10 mm/min. Specimens from both groups tolerated the walking fatigue test. Mean bending stiffness of 3-point fixation was 84% higher than intramedullary constructs (p = .002). Mean dorsal angulation of intramedullary was thrice that of 3-point fixation constructs (p = .008). Mean load to failure of 3-point fixation was 30% higher than intramedullary constructs (p = .001). Three-point fixation provide superior biomechanical stability compared to intramedullary proximal screw placement. The surgical technique using 3-point proximal screw fixation can offer robust fixation and lead to better clinical outcomes.

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.

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.

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.

Minimally Invasive Chevron Akin (MICA) Osteotomy Corrects Radiographic Parameters but Not Central Metatarsal Loading in Moderate to Severe Hallux Valgus without Metatarsalgia

BACKGROUND

Central metatarsal pressure is increased in patients with hallux valgus, but the pedographic outcomes after hallux valgus (HV) correction are inconclusive. No known literature has reported the pedographic outcomes after HV correction with Minimally Invasive Chevron and Akin Osteotomy (MICA).

METHODS

A prospective cohort of 31 feet from 25 patients with moderate-to-severe symptomatic HV but without metatarsalgia underwent MICA and was evaluated using radiographic parameters and pedographic measurements (Footscan®, RSscan International, Olen, Belgium). Data were collected preoperatively and 3 months after surgery.

RESULTS

The radiographic parameters of the hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle, first metatarsal head lateral shape, and lateral sesamoid grade significantly improved after MICA. The corrected first metatarsal length was significantly shortened by 2.3 mm, with consistent second metatarsal protrusion distance, lateral Meary's angle, and calcaneal pitch angle. Max force, max pressure, cumulative force, and cumulative pressure on the central metatarsals did not show significant changes between pre- and post-operative measurements, while these parameters significantly decreased in the hallux and first metatarsal area.

CONCLUSION

MICA effectively corrects radiographic parameters but does not reduce central metatarsal loading in patients with moderate-to-severe HV without metatarsalgia.

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.

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.

Minimally Invasive Chevron Akin Osteotomy: Preoperative Planning Using the Radiographic First-Ray Squeeze Test

Background

Recognizing preoperative first-ray hypermobility is important to planning hallux valgus (HV) surgery. A recent study showed the minimally invasive chevron Akin (MICA) osteotomy increased varus displacement of the proximal fragment of the first metatarsal osteotomy. The present study aims to evaluate the ability of the radiographic first-ray squeeze test to predict the varus displacement of the proximal fragment of the first metatarsal osteotomy when performing the MICA procedure.

Methods

A prospective case series of patients with moderate to severe HV who underwent MICA was performed. The HV deformity correction was analyzed by comparing the preoperative and 12-week postoperative hallux valgus angle (HVA) and the intermetatarsal angle between the first and second rays (1-2 IMA). The ability of the radiographic first-ray squeeze test to predict the varus displacement of the first metatarsal was done by comparing the preoperative 1-2 IMA measured in the AP radiographic first-ray squeeze test (IMA-ST) with the intermetatarsal angle between the second metatarsal and the axis of the first metatarsal osteotomy proximal fragment (IAPF) taken 12 weeks postoperatively.

Results

Between July 2022 and May 2023, a total of 39 feet in 28 patients underwent MICA. The mean IMA improved from 13.8 (SD = 2.2) to 3.8 degrees (SD = 1.5) (P < .001), and the mean HVA improved from 27.8 (SD = 6.1) to 4.9 degrees (SD = 2.5) (P < .001). A linear regression analysis revealed that IMA-ST is highly associated with the 12 week assessed IAPF (P < .001).

Conclusion

The preoperative radiographic first-ray squeeze test appears to predict with high fidelity the varus displacement of the proximal fragment of the first metatarsal that can occur after the MICA procedure.Level of Evidence: Level III, prospective 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.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

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.

Radiographic Forefoot Width Following Minimally Invasive Chevron Akin Bunionectomy

Background

Hallux valgus (HV) is a common cause of pain and deformity of the forefoot. Minimally invasive chevron Akin (MICA) bunionectomy is a method for HV correction associated with less pain and swelling, with early return to weightbearing in a regular shoe. The purpose of this study was to determine how the MICA procedure affects forefoot width.

Methods

Twenty-eight patients (26 female, 2 male; 9 left, 19 right) at a single institution who underwent primary MICA for HV correction by 3 treating surgeons were retrospectively reviewed. Pre- and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), bony forefoot width, and soft tissue forefoot width were measured by 2 independent observers. Radiographic measurements were calibrated using fifth metatarsal length. Wilcoxon signed rank test compared changes in HVA, IMA, DMAA, and forefoot widths. Pearson correlation coefficient evaluated association between HVA, IMA, DMAA, and changes in forefoot width.

Results

At mean follow-up of 5.4 (range 3-13.7) months, bony forefoot width decreased significantly by 3.7 mm (4%, P < .001) and soft tissue forefoot width decreased by 2.5 mm (2%, P < .01). Decrease in HVA was moderately correlated with change in bony forefoot width (r = .38, P < .05) and change in soft tissue forefoot width (r = .45, P < .05). Decrease in IMA was moderately correlated with change in bony forefoot width (r = .45, P < .05) and change in soft tissue forefoot width (r = .44, P < .05).

Conclusion

The MICA procedure resulted in modest, yet significant, decrease in both bony and soft tissue forefoot width. Decrease in HVA and IMA demonstrated moderate correlation with changes in forefoot width. Patients can be counseled on these changes leading up to, and after, MICA bunionectomy surgery.

Level of Evidence

Level III, retrospective comparative series.

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.

Modified scarf osteotomy for hallux valgus: From a finite element model to clinical results

PURPOSE

Finite element (FE) analysis and clinical follow-up were used to evaluate the efficacy of modified scarf osteotomy for moderate-to-severe hallux valgus (HV).

METHOD

We retrospectively evaluated 42 patients (44 feet) who underwent modified rotational scarf osteotomy for moderate-to-severe HV at our institution between January 2010 and January 2019. Radiological indicators and subjective scores were recorded at different time points. To compare the results and elemental characteristics, a FE model of the metatarsophalangeal (MTP) joint that included anatomically realistic geometrical and structural characteristics was built. The biomechanical features and correction differences in dynamic loads as well as the incidence of troughing were estimated.

RESULTS

Both the hallux valgus angle (HVA) and intermetatarsal angle (IMA) showed significant improvement 6 weeks postoperatively (p < 0.05); additionally, the HVA increased from 6 weeks postoperatively to the last follow-up, while the IMA showed no significant changes (p > 0.05). The subjective scores significantly improved from the preoperative period to the last follow-up. The percentages of troughing and recurrence were remarkably low in our pilot study because of the innate stability of the modified rotated fixation.

CONCLUSION

Our preliminary findings suggest that modified rotational scarf osteotomy offers sufficient stability, correct HV deformity effectively, and good clinical outcomes for moderate to severe HV.

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.

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.

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.