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.

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.

Hallux valgus is a common condition. There is a consensus that distal metatarsal osteotomies have positive outcomes for the correction of mild-to-moderate deformities, and that proximal osteotomies are preferable for more severe ones. The well-known scarf osteotomy technique is considered powerful enough for both types of deformation and is described without internal fixation. We aimed to describe a new surgical technique for hallux valgus percutaneous scarf like osteotomy (PSLO) without internal fixation, and to report the medium-term radiological and clinical outcomes.

A combination of a PSLO without internal fixation will lead to optimal results.

This retrospective case series reports on 126 cases involving 106 patients who underwent hallux valgus surgery with the PSLO technique +/- Akin, +/- lateral release. The osteotomy was stabilized by a bandage, and immediate weight bearing was allowed. The surgeries took place in 3 clinics in France from March 2016 to July 2017.

All radiological parameters: hallux valgus angle (HVA), the 1-2 intermetatarsal angle (IMA) and the distal metatarsal articular angle (DMAA) showed statistically significant improvement. The mean preoperative HVA, IMA and DMAA were 27.7 °, 14.2 ° and 12.7 ° respectively. The mean postoperative HVA, IMA and DMAA were 8.23 °, 8.1 ° and 3.8 °, respectively. Clinically, 97% were satisfied or very satisfied with the results, 92% could wear "normal" shoes (45 days - 6 months), 99% returned to the same athletic activities after surgery (3-5 months), and the average time to return to work was 4 weeks (1 day - 51 days).

The combination of scarf -like osteotomy and the percutaneous technique provide sufficient initial stabilization through the large horizontal area of contact between the fragments and the preservation of the attachment of the soft tissue. The lack of internal fixation significantly shortens the surgery time, cost, and reduces x-ray exposure without compromising the results.

III, retrospective comparative study.

Hallux valgus (HV) deformity, which is characterized by lateral deviation and pronation of the metatarsophalangeal joint, demonstrates complex 3-dimensional challenges, thus prompting the development of various surgical approaches, including traditional Chevron osteotomy (CO) and novel triplanar Chevron osteotomy (TCO). The objective of this study is to determine TCO at various tilt angles by employing 3D printing for ex vivo osteotomy angle simulations and computer modeling to correct deformities across 3 planes, thus aiming to enhance surgical outcomes by preserving or even increasing the length of the first metatarsal and thereby overcoming the limitations of CO. In this study, we collected and analyzed non-weight-bearing CT data from 55 patients (61 feet) with mild-to-moderate hallux valgus, plantar callosities and metatarsalgia from June 2019 to June 2020. The study utilized Mimics software for 3D digital reconstructions and simulation osteotomy of both TCO and CO. For both procedures, the apex was centered at the first metatarsal head, with CO specifically oriented towards the fourth metatarsal head at a 60° angle. The plantar-oblique Chevron osteotomy (POCO) was defined by a 15° plantar tilt, whereas TCO involved a further 9° tilt towards the metatarsal head. The key metrics that were measured included the hallux valgus angle (HVA), 1-2 intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA) and first metatarsal length (FML). Our study aged between 30 and 71 years, with an average age of 47.37 years. Postoperative assessments using Mimics software showed significant improvements in reducing the HVA, IMA, and DMAA after CO and TCO. However, when comparing both techniques, their corrective capacities were roughly equivalent, with no significant differences observed in these metrics. Notably, compared with CO, TCO significantly increased the FML (P < .001), thus suggesting that TCO has greater potential to effectively prevent transfer metatarsalgia. This study underscores the ability of TCO to significantly extend the first metatarsal, with precise adjustments to its distal tilt to tailor deformity corrections. In computational simulation experiments, TCO offers a superior alternative to CO for treating hallux valgus by addressing 3-dimensional deformities and preserving or even increasing FML, thereby preventing transfer metatarsalgia.

Background/Objectives: Reverdin-Isham osteotomy is effective in correcting moderate hallux valgus deformity but has certain limitations when correcting a deformity in the sagittal plane. This study aimed to evaluate the impact on pain, functionality, and radiological measures of angular corrections, and the safety of the Reverdin-Isham lateral translation technique through minimally invasive surgery in the treatment of a moderate hallux valgus compared to Reverdin-Isham standard osteotomy. Methods: A pilot 6-month prospective cohort study was conducted on adults over 18 years old with a hallux valgus in at least one foot. The study exposure was the use of the Reverdin-Isham lateral translation technique. The outcome variables were pain and functionality through VAS and AOFAS scales, respectively, and radiological measurements of the first toe metatarsophalangeal angle (MPA), first space intermetatarsal angle (IMA), proximal articular set angle (PASA), distal articular set angle (DASA), metatarsal formula, and position of sesamoids in the AP projection. Results: The study involved 60 participants. Results indicate significant reductions in pain and radiological measures in both cohorts: MPA improved by 23.13 degrees, IMA by 5.93 degrees, and sesamoid position by 4.23 degrees in patients who underwent the lateral translation technique versus 13.20, 3.30, and 1.57 degrees, respectively, in patients who experienced the standard Reverdin-Isham technique. The lateral translation method showed greater reductions in these metrics compared to the standard Reverdin-Isham technique (p < 0.05). Conclusions: Percutaneous Reverdin-Isham techniques, both standard and with lateral translations, effectively corrected moderate hallux valguses. However, the lateral translation method provided greater reductions in MPA, IMA, and sesamoid positions, making it more suitable for deformities with IMAs over 15 degrees.

The expression "learning curve" indicates the relation between the time needed to learn a new technique and the technique-related outcome. Percutaneous surgery (also called "minimally invasive surgery") has experienced sustained and respectable growth, especially in forefoot deformities. The main purpose was to assess the number of feet necessary to become skilled in a specific minimally invasive surgery (MIS) procedure.

From January 2015 to June 2018, 46 consecutive patients were evaluated and included in the study. Patients were divided into 2 groups according to the surgery period: first 30 feet (Group 1), and subsequent 30 feet (Group 2) from the whole population evaluated. Age, body mass index, and operative time were evaluated. Hallux valgus angle and the 1 to 2 intermetatarsal angle were also measured. Patients were assessed according to the American Orthopedic Foot and Ankle Society (AOFAS) forefoot scale, the Foot and Ankle Ability Measure activities of daily living (FAAM ADL) subscale and the visual analog scale (VAS).

The comparison of the 2 groups showed statistically significant differences in hallux valgus angle (HVA) but not in intermetatarsal angle (IMA). The mean improvement between pre- and postoperative FAAM ADL, VAS, and AOFAS score in Group 1 were 12.83, 3.93, and 24.77 points, respectively. In Group 2, the mean improvement between pre- and postoperative FAAM ADL, VAS, and AOFAS scores were 15.19, 4.3, and 24.5 points, respectively. The differences between groups in FAAM ADL score was statistically significant (P = 0.0364). Group 1 showed a global complication rate of 16.67% (n = 5) while group 2 showed 3,3% (n = 1).

After the first 30 cases, radiographic, clinical, and functional outcomes substantially improved, and the level of the perioperative complications decreased. The results suggest that the learning curve plateau for performing a percutaneous subcapital osteotomy can be reached after 30 surgeries.

Level III.

In the field of minimally invasive surgery (MIS) for the treatment of hallux valgus (HV), different techniques have begun to emerge in the literature concerning the distal osteotomy of the first metatarsal bone, the synthesis or not of the metatarsal head, the possible association with lateral soft tissues release (LSTR) and osteotomy of the base of the first phalanx.

To evaluate the role of LSTR on percutaneous HV correction, evaluating functional and radiographical results.

From January 2012 to May 2016 a total of 396 patients with mild to moderate symptomatic HV treated with the MIS technique were included in this retrospective study. The technique provides no internal fixation (WOS). Patients were divided into the LSTR group and no LSTR group (LSTR N). This surgical procedure (LSTR) was reserved for insufficient HV angle (HVA) correction during fluoroscopic control. Patients were evaluated at each follow-up by two other authors after appropriate training by senior authors (first practitioners). Clinical evaluation was performed before surgery, 6 mo after surgery, and 48 mo follow-up. American Orthopaedic Foot and Ankle Society (AOFAS) and visual analog scale (VAS) score was used to evaluate pain and function, and complications were recorded. In addition, the incidence of relapses and the degree of joint range of motion (ROM) with the association with the LSTR (capsule, adductor tendon, phalanx-sesamoid ligament, and the deep transverse metatarsal ligament) were evaluated. Radiological parameters included HVA and intermetatarsal angle (IMA). Patient satisfaction was assessed. Student t-test and Fisher exact test were used to assess statistical analysis.

From our study it is clear that no differences in term of HVA, VAS, IMA correction, rate of complications, and AOFAS score were found between groups, while a significant improvement of the same variables was found in each group between pre and postoperative values. A significant improvement in ROM at 6 mo (P = 0.018) and 48 mo (P = 0.02) of follow-up was found in LSTR N group. Complications were rare in both groups.

LSTR procedure on percutaneous HV correction seems to increase postoperative joint stiffness with a comparable incidence of relapse and a low incidence of complications.

Although percutaneous hallux valgus surgery is increasing in popularity, concerns about safety regarding neurovascular and tendinous structures remain. The first aim of this body-donor study was to evaluate the safety of three common percutaneous portals. Secondly, to evaluate percutaneous surgery effectiveness in completing adductor tendon release and first ray osteotomies.

Twenty body-donor feet were included and underwent three percutaneous procedures, which are commonly performed in combination: distal metatarsal osteotomy, proximal phalanx osteotomy and adductor tendon release. After surgery, the distance between surgical portals and relevant neurovascular structures was measured. Damage to this neurovascular structures, tendons or articular cartilage was noted. Completion of adductor tendon release and osteotomies was verified.

The medial dorsal digital nerve of the hallux was damaged in two specimens. Mild peritendon damage was observed in two feet. The rest of neurovascular and tendinous structures were intact. No cartilage damage was observed. The distance between the adductor tenotomy portal and the lateral dorsal digital nerve of the hallux and the first dorsal metatarsal artery was 3.3mm (SD 1.4) and 2.4mm (SD 1.8), respectively. Complete adductor tenotomy was achieved in 14 feet.

The structure with the highest risk of damage during percutaneous hallux valgus surgery is the medial dorsal digital nerve. The lateral dorsal digital nerve and the first dorsal metatarsal artery might be at risk due to the small distance to the adductor tendon release portal. A deep anatomical knowledge and a meticulous surgical technique are required to avoid lesions to neurovascular and tendinous structures.

V, Cadaveric study.

Minimally invasive surgery (MIS) is currently used to correct hallux valgus deformities. Most studies reporting on MIS techniques to correct hallux valgus deformities included patients with postoperative complications. These reported complications, with an average rate of 23%, had significant negative effects on the clinical outcomes in this patient population. In the present study, a cohort of 63 women who underwent MIS hallux valgus correction was assessed preoperatively and at a mean follow-up of 1.0, 4.7, and 6.5 years using the American Orthopaedic Foot and Ankle Society (AOFAS) scale and the Manchester Oxford Foot Questionnaire (MOXFQ). The main criterion for inclusion in this cohort was a lack of complications during the entire follow-up period. The results showed significant improvements in both AOFAS and MOXFQ scores between the preoperative and 1-year follow-up assessments. By contrast, clinically small and nonsignificant changes were observed among postoperative follow-up values. The number of enrolled patients needs to be increased in future studies, with different surgeons and techniques included. Nevertheless, our study findings will inform patients about the outcomes they can expect over the years if no complications occur.

Distal first metatarsal osteotomy is used to correct mild or moderate hallux valgus (HV). We designed a cadaveric study to compare the resistance to axial load between two percutaneous distal first metatarsal osteotomies: Bösch osteotomy and percutaneous chevron. The first aim of this study was to develop a systematic technique for measuring the sagittal displacement on lateral foot X-rays. Our second objective was to measure the resistance to axial load for both of these osteotomies.

Ten pairs of freshly frozen cadaveric feet were randomly assigned to one of the two techniques investigated. Pre- and post-operative lateral X-rays were obtained. After surgery, the feet were placed under progressive axial loads up to 60 kg. Metaphyseo-diaphyseal angle (MDA) and the distance between bone fragments were measured, and the differences between the two techniques were statistically assessed.

The MDA decreased in both surgical techniques. The mean plantar tilt was -6.90 degrees (SD = 10.251) for chevron osteotomy and -5.34 degrees (SD = 16.621) for Bösch osteotomy. There was no significant difference between the techniques (p = 0.41). Regarding the distance between the bone fragments, the Bösch osteotomy produced more plantar displacement than the chevron osteotomy, which was statistically significant for the 10 and 20 kg loads (p = 0.031 and 0.04, respectively). At loads ≥ 30 kg, the bone fragment distance did not differ significantly between the techniques (p = 0.114).

Although the chevron technique confers higher stability regarding fragment displacement during axial loading, both techniques increase the plantar angulation of the metatarsal head.

Cadaveric study.

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.

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.

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).

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 IV, prospective case series.

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.

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.

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.

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.

IV.

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.

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).

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%).

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 IV, retrospective study.

To estimate the comparative effect of open and percutaneous hallux valgus (HV) surgery on patients' quality of life (QoL) using the American Orthopedic Foot and Ankle Society (AOFAS) scale including total score and individual domains (pain, function, and alignment).

MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were systematically searched from inception to March 2020 for studies on the effect of HV surgery on patients' QoL using the AOFAS score. A standardized mean difference score was calculated on the total AOFAS score and on each AOFAS domain (pain, function, and alignment) using Cohen's d index.

Considering the 53 published studies included, the pooled effect size (ES) estimates for the AOFAS total score were 3.69 (95% CI 3.37-4.01; I² = 95.5%) for open surgery and 3.40 (95% CI 2.99-3.80, I² = 88.2%) for percutaneous surgery. The total pooled ES estimate was 3.61 (95% CI 3.35-3.87, I² = 94.5%). Considering the pain domain, the pooled ES estimates were 2.21 (95% CI 1.98-2.43, I² = 64%) for open surgery and 2.52 (95% CI 1.83-3.20, I² = 92.6%) for percutaneous surgery. For the function domain, the pooled ES estimates were 1.37 (95% CI 0.93-1.81, I² = 91%) for open surgery and 2.28 (95% CI 1.10-3.47, I² = 96.8%) for percutaneous surgery. Finally, the pooled ES estimates for the alignment domain were 3.99 (95% CI 3.51-4.47, I² = 85.7%) for open surgery and 2.66 (95% CI 2.23-3.09, I² = 78.5%) for percutaneous surgery.

Our data support that HV surgery increases the total AOFAS score as well as the AOFAS scores by domain (pain, function, and alignment). Furthermore, our data show that HV surgery increases patients' QoL, after both open and percutaneous surgery, without differences between them.

Minimally invasive techniques in the treatment of hallux valgus deformity have seen growing popularity since the 1990s. The purpose of this article is to assess the existing body of literature as to the safety and efficacy of minimally invasive techniques and identify areas for further development. The appeal of minimizing soft tissue damage, reducing surgical time, and faster recovery is currently offset by the initial learning curve and a lack of high-quality studies regarding minimally invasive techniques. There is currently insufficient evidence to recommend one minimally invasive technique over another and further high-level evidence studies are warranted.

The objective of the study was evaluation of the clinical and radiologic outcomes and complications following the minimally invasive chevron procedure employing the Akin osteotomy with percutaneous transosseous suture as compared to screw fixation.

Between 2018 and 2019, the authors performed 103 minimally invasive chevron (MIC) with Akin osteotomies. In 54 patients, the Akin osteotomy was performed with screw stabilization (group A), and in 49 with percutaneous transosseous suture (group B). Preoperatively and 1 year later, the authors employed anteroposterior and lateral weightbearing radiographs of the feet to evaluate interphalangeal angle (IPA), distal phalangeal articular angle (DPAA), proximal phalangeal articular angle (PPAA), intermetatarsal angle (IMA), hallux valgus angle (HVA), and functional result using the American Orthopaedic Foot & Ankle Society (AOFAS) hallux-metatarsophalangeal-interphalangeal scale. Furthermore, all additional procedures and complications were recorded.

Both groups demonstrated a statistically significant decrease of the value of HVA (group A: from 34.1° to 14.0°, group B: from 33.6° to 13.0°), DPAA (group A: from 12.1° to 4.0°, group B: from 11.5° to 3.4°), PPAA (group A: from 4.6° to 1.7°, group B: from 4.3° to 1.5°), IMA (group A: from 15.1° to 8.0°, group B: from 14.7° to 7.5°) and IPA (group A: from 14.1° to 6.3°, group B: from 12.9° to 5.1°). Functional improvement as measured using the AOFAS scale was achieved in both groups (group A: from 42 to 90 points, group B: from 40 to 89 points). No cases of bone nonunion or delayed union and permanent damage to the medial dorsal cutaneous nerve were seen. Two group B patients underwent conversion of the fixation of the Akin osteotomy to screws, 3 patients had their MICA screws and 1 Akin screw removed in the outpatient setting.

The minimally invasive chevron osteotomy with transosseous suture stabilization of the Akin osteotomy was a safe method with good functional results that were comparable to the outcomes achieved when using screw fixation.

Level III, retrospective comparative study.

Minimally invasive (MIS) or percutaneous surgery has evolved rapidly through the development of novel techniques with precise description, correct indications, and the incorporation of modifications of safe and effective techniques described in open surgery. The correct term to describe these procedures should be percutaneous and MIS should be reserved for procedures between percutaneous and open surgery (eg, osteosynthesis). According to results, third-generation techniques are useful, effective, and easier than open procedures. It seems that MIS surgery has an extensive learning curve, and therefore it may be difficult to duplicate the results shown on already-published data.

Numerous publications of the late 20th century have presented the radiological outcome of open technique for distal metatarsal osteotomy for mild to moderate hallux valgus and the clinical outcomes by means of well-established scoring systems which have been published and make these open techniques today's benchmark and gold standard. Minimally invasive procedures reduce surgical trauma because they are performed without large incisions, and injury to the soft tissues is limited. This has the theoretical advantages of improved recovery and decreased rehabilitation times. There is however limited literature to prove the same for minimally invasive surgery for hallux valgus.Our aim was thus to pool all available comparative literature on minimally invasive hallux valgus surgery done for mild to moderate hallux valgus versus open surgical approaches.

A PubMed, Embase and Scopus search was performed using the keywords ('hallux valgus' OR bunion) AND ('minimally invasive' OR percutaneous) AND osteotomy. A total of 473 records were identified and out of which nine studies were included in the final review.

Most available studies are either randomized control trials, or prospective cohort studies providing good level of evidence. Radiological analysis showed similar correction with both MIS and open osteotomies. In functional analysis results were different with open techniques providing better results in terms of AOFAS score. (p < 0.0001). VAS score and complication rate were similar in both groups.

We conclude that based on available literature MIS provides equivalent radiological outcomes with respect to open surgery but functionally despite the promising results (good to excellent in most series), the outcomes in terms of function are not as good as open surgery. MIS techniques provide satisfactory outcomes for mild-to-moderate severity of hallux valgus though not as good as open surgery. There is evolving literature for this relatively new procedure. Longer duration of follow up and bigger numbers would allow for more meaningful data analysis and conclusions to be drawn as more studies come forward.

Percutaneous surgery is experiencing sustained growth based on third-generation techniques. This cadaveric study was designed with the main goal of exploring the risk of iatrogenic tendon and neurovascular lesions and defining the safe zones in a percutaneous, intra-articular, chevron osteotomy (PeICO) procedure, as well as assessing the accuracy of the osteotomy itself.

Eight feet from below-knee fresh-frozen specimens were selected. After the procedure, the specimens were dissected, and structures were inspected for damage.

The results of the safety measurements were as follows: (1) distance between portal 1 (P1) and the lateral border of the extensor hallucis longus (EHL) tendon: average 17.6 mm (range 12.7-21.3); (2) distance between P1 and the dorsomedial digital nerve (DMDN): average 7.2 mm (range 1.6-10.4); (3) distance between P1 and the metatarsophalangeal joint: average 15.7 mm (range 9.4-20.5); distance between portal 2 (P2), or the osteosynthesis portal, and the metatarsophalangeal joint: average 25.5 mm (range 22-30.4); distance between P2 and the lateral border of the EHL tendon: average 12.7 mm (range 8-16.7); and distance between P2 and the DMDN: average 4.1 mm (range 1.7-8.2). There were no iatrogenic injuries. The osteotomy angulation in the sagittal plane (reproducibility) average was 85.6 degrees.

There were no iatrogenic injuries on this cadaveric study of PeICO.

This study will help orthopedic surgeons understand the risks of performing percutaneous surgery by mimicking an accepted open technique (chevron).

In the last decade, interests in minimal incision surgery have been growing. Theoretically, this kind of procedure could decrease time to recovery and rehabilitation, with a reduction in morbidity. The present study assessed clinical and radiological outcomes and complications of percutaneous surgery for mild-to-moderate hallux valgus using Reverdin-Isham and Akin osteotomies without fixation after 60 months of follow-up.

A series of 48 patients (57 cases) with medium-to-moderate hallux valgus underwent the same percutaneous surgery, between 2003 and 2011. Data collection involved preoperative dorsal flexion, plantar flexion, M1P1, M1M2, DMAA angles, AOFAS scale score, and subjective satisfaction.

AOFAS scale score rose from a preoperative median of 55.9-89.2/100 postoperatively (p < 0.001); 51 surgical procedures (89.5%) were considered as satisfactory or very satisfactory by patients at the end of follow-up. Hallux valgus and distal metatarsal articular angle (DMAA) were significantly reduced (29.3° and 14.1°-15.4° and 7.7°, p < 0.001, respectively). There was a significant increase in MTPJ 1 stiffness (p < 0.001).

Percutaneous correction by Reverdin-Isham and Akin osteotomies seems to be effective in isolated medium-to-moderate hallux valgus. Stiffness observed is comparable to other percutaneous and open procedures but needs to be compared in a randomized controlled clinical trial to extra-articular percutaneous procedures without capsule detachment in association with an internal fixation which allows an early mobilization.

IV.