Introduction Hallux valgus is a common disorder of the foot. The chevron osteotomy is among the most common methods of surgically correcting mild to moderate hallux valgus, though it has been associated with inadequate distal metatarsal articular angle (DMAA) correction and a risk of hallux valgus recurrence. This study aimed to compare the effectiveness of the triplanar and biplanar chevron osteotomies in correcting mild to moderate hallux valgus. Specifically, we aimed to determine if the triplanar chevron osteotomy results in superior correction of the DMAA compared to the biplanar chevron osteotomy. Methods A retrospective review of patient medical charts and preoperative and postoperative radiographs was performed. A total of 55 patients were included, with 28 patients in the biplanar chevron group and 27 patients in the triplanar chevron group. The DMAA and intermetatarsal (IM) angles were measured on preoperative and postoperative radiographs. Statistical analysis was carried out on SPSS. Results The DMAA and IM angles improved significantly in both groups (p = <0.001). There was no significant difference in the mean postoperative IM angle in the biplanar versus triplanar groups (9.58 degrees versus 9.19 degrees, respectively, p = 0.279). However, there was a significant difference in the mean postoperative DMMA in the triplanar versus biplanar groups (7.88 degrees versus 8.79 degrees, respectively, p = 0.026). Conclusions The biplanar and triplanar chevron osteotomies are equally effective in reducing IM angle in mild to moderate hallux valgus. The triplanar chevron osteotomy significantly increases DMAA correction when compared to the biplanar chevron osteotomy and may therefore reduce hallux valgus recurrence.
Hallux valgus (HV) is a prevalent foot deformity with complex pathogenesis. This study aims to compare distal minimally invasive osteotomy and open chevron osteotomy for HV treatment. A Network Meta-Analysis METHODS: The meta-analysis consisted of 14 studies (842 patients) from PubMed, Web of Science, Embase, and Cochrane Library (until April 2026). The retrieval strategies comprised the terms 'hallux valgus', 'percutaneous', 'minimally invasive surgery', 'mica' and 'chevron'. Outcomes included hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), and AOFAS scores, which were calculated leveraging a 95 % credible interval (CI). Study quality was evaluated adopting NIH tools, and statistical analysis was carried out utilizing R (version 4.4.1). A total of 14 articles involving 842 participants were included in this study. The results indicated that, compared with open chevron osteotomy, minimally invasive transverse osteotomy showed a more effective therapeutic effect in improving the HVA ([SD: -1.5, 95 % CI (-2.5, -0.39)] (SUCRA = 98.17 %) and IMA ([SD: -0.76, 95 % CI (-1.3, -0.20)] (SUCRA=98.82 %). In terms of improving the DMAA, minimally invasive chevron osteotomy (SD: -5.8, 95 % CI: -8 to -3.7; SUCRA = 98.80 %) and minimally invasive transverse osteotomy (SD: -2.6, 95 % CI: -3.9 to -1.4; SUCRA = 54.18 %) were both more effective. Minimally invasive chevron osteotomy ranked highest in terms of AOFAS score (SUCRA=81.53 %). However, This estimate was associated with a wide CI [SMD:2.4, 95 %CI(0.48,4.3)]. Minimally invasive transverse osteotomy is more effective for radiographic correction (HVA/IMA), whereas minimally invasive chevron osteotomy appears to improve functional outcomes. These findings suggest potential differences between the techniques but should be interpreted in light of indirect comparisons and study heterogeneity.
The Mitchell and Chevron osteotomies are two widely performed surgical techniques for the correction of hallux valgus deformities. While both approaches are commonly used, there remains limited biomechanical evidence comparing their structural stability, particularly when paired with advanced fixation techniques. This study aims to evaluate and compare the biomechanical properties of these procedures when utilizing the third-generation minimally invasive (MIS) screw fixation technique. Sixteen synthetic first metatarsal (Sawbones Pacific Research Laboratories, Vashon, WA) were divided into two groups. The Mitchell osteotomy (n = 8) and the Chevron osteotomy (n = 8) were performed to simulate hallux valgus correction surgery. Both osteotomy groups were fixed using an identical technique. Two parallel, fully threaded, headless screws were positioned separately: one in a three-points fixation and the other in an intramedullary pattern. Each specimen was tested using a cantilever bending model. Following a 20-N preload, 500 cycles loading test was applied with the force ranging from 20 to 200 N (valley to peak). Interfragmentary displacement was recorded after the cyclic loading test. Finally, all specimens were subjected to destructive loading until catastrophic failure occurred. In terms of construct stiffness, there were no significant differences (p = 0.12). The value was 321.8 ± 91.4 N/mm in the Mitchell osteotomy group and 224.3 ± 95.2 N/mm in the Chevron osteotomy group. All specimens completed the whole cyclic loading test without catastrophic failure, and the fragment displacement after 500 cycles was 1.2 ± 0.7 mm for the Mitchell osteotomy and 1.9 ± 1.1 mm for the Chevron osteotomy group (p = 0.20). No significant differences were observed between the groups regarding the ultimate failure load and failure mode. The third generation MIS screw fixation technique provides comparable construct stability in both Mitchell and Chevron osteotomies, particularly in conditions requiring substantial correction. The current study offers biomechanical evidence supporting its clinical application.
Distal Chevron osteotomy is commonly used for mild-to-moderate hallux valgus, but long-term loss of correction and radiographic recurrence remain concerns, particularly when distal articular alignment and sesamoid position are not adequately restored. We compared long-term radiographic and clinical outcomes of a modified rotational wedge distal metatarsal osteotomy versus standard distal Chevron osteotomy in adults with mild-to-moderate symptomatic hallux valgus. In this single-center retrospective cohort study, 100 feet (100 patients) treated between 2010 and 2019 were analyzed (Modified, n = 46; Chevron, n = 54) at a mean follow-up of 101.2 ± 11.5 months. Soft-tissue balancing was standardized, with an intra-articular lateral release performed in both groups. Outcomes included radiographic measures (hallux valgus angle [HVA], intermetatarsal angle [IMA], distal metatarsal articular angle [DMAA], and medial sesamoid position), clinical scores (AOFAS, VAS), recurrence, and complications. Radiographic recurrence was defined as final HVA > 15°. Final AOFAS scores were similar between groups (p = 0.621), and the between-group difference in final VAS pain scores did not remain significant after Benjamini-Hochberg false discovery rate (BH-FDR) adjustment (q = 0.057). Compared with the Chevron group, the Modified group demonstrated superior final radiographic alignment, with lower HVA and IMA (both p < 0.001) and lower DMAA (p = 0.002). Despite worse baseline sesamoid subluxation, the Modified group achieved a more central final sesamoid position (p = 0.010). Radiographic recurrence was less frequent in the Modified group (4.3% vs. 27.8%), representing a relative risk of 0.16 (95% CI 0.04–0.65; p = 0.003); this association persisted after inverse probability of treatment weighting (adjusted odds ratio [aOR] 0.09, 95% CI 0.01–0.60; p = 0.013). Complication rates were low and comparable. At long-term follow-up, the modified rotational wedge distal osteotomy yielded superior radiographic alignment and a lower recurrence rate than distal Chevron osteotomy, without higher complication rates, while functional outcomes were similar. The online version contains supplementary material available at 10.1007/s00402-026-06315-2.
Usually affecting the medial prominence of the first metatarsophalangeal (MTP) joint, hallux valgus is a complicated malformation of the first ray that causes deformed joint structure, dysfunction, and increasing stiffness. The most common methods for treating hallux valgus malformation are scarf osteotomy and chevron osteotomy. Due to the inconsistent and contradictory findings among the studies, we conducted this systematic review and meta-analysis to compare chevron and scarf osteotomies in the management of hallux valgus deformity. Using the following search strategy: "Chevron" AND "Scarf" AND "Osteotomy" AND "Hallux Valgus", and from inception until October 2024, we searched PubMed, Web of Science, and Scopus for relevant publications that needed to be screened to see if they could be included in our study. We performed a meta-analysis of the articles included using Review Manager version 5.4 software, pooling the mean difference (MD) of various outcomes at 95% confidence intervals (CI) and a p-value of 0.05. Chevron osteotomy was observed to lower the hallux valgus angle (HVA) with a significant difference compared with scarf osteotomy, showing a MD = -2.44 (95% CI: -4.57, -0.31, p = 0.03). However, no significant difference was observed between both osteotomies regarding the reduction of intermetatarsal angle (IMA), showing a MD = -0.33 (95% CI: -1.32, 0.66, p = 0.52). Chevron osteotomy was observed to be associated with higher American Orthopedic Foot and Ankle Society (AOFAS) compared with scarf osteotomy with MD = 2.21 (95% CI: 0.7, 3.71, p = 0.004) and I2 = 0%, however, no significant difference was observed regarding their effect on pain with SMD = -0.07 (95% CI: -0.44, 0.31, p = 0.73). Chevron osteotomy was observed to be superior to scarf osteotomy in lowering the HVA and improving functional outcomes presented by AOFAS measurements. However, they were comparable in their effect on IMA and pain measurements.
Distal metatarsal chevron osteotomy is widely used in hallux valgus surgery, and many different osteotomy methods have been described in the literature because of its complications, such as nonunion, loss of reduction, and osteolysis. This study aimed to biomechanically compare the newly defined Parmaksızoğlu osteotomy and the distal chevron osteotomy. A total of 14 sawbone models were divided into two groups, and Parmaksızoğlu and distal chevron osteotomies were performed with the created incision guides. For biomechanical tests, fatigue testing was performed on the samples with 1,000 cycles of axial loading up to 10 N at a 15° angle. Rigidity, dorsal angulation, and deforming force values were recorded. In the chevron osteotomy group, the average rigidity value of the 1,000th cycle was measured as 3.69 N/mm, the dorsal angulation value was 1.95°, and the average deforming force value was 20.14 N. In the Parmaksızoğlu osteotomy group, the average rigidity value of the 1,000th cycle was measured as 2.28 N/mm, the dorsal angulation value was 2.12°, and the average deforming force value was 26.72 N. In this study, Parmaksızoğlu osteotomy and chevron osteotomy were compared in terms of rigidity, dorsal angulation, and deforming force, and no statistically significant superiority of one technique over the other was observed. It has been statistically shown that the Parmaksızoğlu osteotomy, which has demonstrated a lower complication rate and a higher American Orthopaedic Foot & Ankle Society score in previous studies, has biomechanically similar features to the distal chevron osteotomy.
The optimal osteotomy technique for severe hallux valgus deformity using minimally invasive surgery remains unknown. This study aimed to explore the clinical and radiographic outcomes between chevron and transverse osteotomies in patients with severe hallux valgus deformity. A retrospective cohort study was conducted including 131 feet (109 patients) with complete radiographic follow-up who underwent hallux valgus correction using either percutaneous chevron and Akin osteotomy (PECA) (n = 43 patients, 50 feet) or metaphyseal extra-articular transverse and Akin osteotomy (META) (n = 66 patients, 81 feet) techniques. Radiographic parameters including hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured at baseline, 6 weeks, and final follow-up. Patient-reported outcome measures were assessed using the Manchester-Oxford Foot Questionnaire (MOXFQ), visual analog scale (VAS) for pain, and EuroQol 5 dimension-5 level questionnaire. Recurrence was defined as a final HVA exceeding 20°. Complication rates and passive correctability were also analyzed. Baseline characteristics were similar between groups, except for significantly higher initial IMA in the PECA group (17.8° vs 15.8°, P = .001). Both techniques achieved significant deformity correction. At final follow-up, the PECA group demonstrated a significantly lower HVA compared to the META group (11.7° vs 14.5°, P = .045), whereas final IMA measurements were similar (5.2° vs 4.9°, P = .642). Recurrence rates were significantly lower in the PECA group (10.0% [95% CI: 4.3%-21.4%] vs 27.2% [95% CI: 18.7%-37.7%], P = .025). Pre-operative passive correctability was significantly higher in the PECA group (68.0% vs 46.9%, P = .020), particularly amongst recurrent cases (80.0% vs 27.3%, P = .047). No significant differences were observed in MOXFQ scores between groups, although VAS pain favored the META group (6.2 [SD 12.3] vs 11.9 [SD 17.5], P = .046). Complication rates were comparable (PECA: 13.2% vs META: 8.6%, P = .40). Complication rates were comparable (PECA: 13.2% vs META: 8.6%, P = .40), with different complication profiles noted between techniques. Both PECA and META techniques provide effective correction of hallux valgus deformity. The higher recurrence rate observed in the META group was associated with a significantly lower rate of pre-operative passive correctability in that cohort. Level III, retrospective comparative study.
To evaluate the efficacy of modified cocktail analgesia in relieving pain after minimally invasive chevron osteotomy for hallux valgus. A retrospective cohort study was conducted to analyze the clinical data of 90 patients with moderate to severe hallux valgus admitted to our hospital from January 2020 to December 2023. Based on the treatment method and the number of affected limbs, the patients were divided into three groups: the modified group (Imp) treated with minimally invasive chevron and Akin (MICA) osteotomy combined with modified cocktail therapy, the traditional group (Tro) treated with MICA osteotomy combined with conventional cocktail therapy, and the control group (NC) treated with MICA osteotomy alone without cocktail therapy. The visual analog scale (VAS) scores for ankle-foot pain from 6 hours preoperatively to 14 days postoperatively, the need for postoperative rescue analgesia, adverse reactions, and complications were observed and compared among the three groups. There were no significant differences in basic conditions such as age and BMI among the three groups. It is in line with the epidemiological statistics of hallux valgus in terms of gender. The VAS scores at 6 hours and 1 day postoperatively were significantly lower in the modified group [(0.67±0.60), (0.68±0.59) respectively] compared to the traditional group [(0.82±0.50), (0.78±0.90) respectively] (P < 0.05). There were no statistically significant differences in VAS scores between groups at 6 hours preoperatively and 7 days and 14 days postoperatively (P > 0.05). Five patients (5.56%) in the modified group required postoperative rescue analgesia, which was significantly fewer than the 12 patients (13.33%) in the traditional group (P < 0.05). Based on the comprehensive statistical results and clinical significance, the modified cocktail therapy has certain clinical reference value in the short-term analgesia management after MICA. It is beneficial for the early postoperative rehabilitation functional exercise of patients and has a good safety effect. It can be used as an optional option for early postoperative pain control. However, it is necessary to objectively recognize the timeliness of its therapeutic advantages. Its long-term analgesic effect shows no significant clinical difference from the traditional cocktail therapy and the simple MICA procedure.
Hallux rigidus is a degenerative condition affecting the first metatarsophalangeal joint. Depending on symptoms, treatment options for symptomatic hallux rigidus include joint resection (such as arthrodesis or arthroplasty) or joint-preserving procedures (like cheilectomy or osteotomies). We present a shortening percutaneous, intra-articular, chevron osteotomy (S-PeICO) technique, which is a modification of the percutaneous intra-articular chevron osteotomy (PeICO) technique previously used to treat hallux valgus. The purpose is to evaluate iatrogenic neurovascular and tendon damage, as well as the accuracy of the osteotomy, including angulation and completion. Twelve fresh-frozen below-the-knee cadaveric specimens were used in this study and diagnosed with Coughlin grade I to III hallux rigidus and mild hallux valgus. To evaluate the procedure's safety, the following data were collected: (1) distance between portal 1 and dorsomedial digital nerve, (2) distance between portal 2 and the medial border of the extensor hallucis longus tendon, (3) distance between portal 2 and the dorsomedial digital nerve, (4) distance between portal 2 and the extensor hallucis capsularis, (5) distance between portal 1 and the metatarsophalangeal joint, and (6) distance between portal 2 and the metatarsophalangeal joint. Additionally, the angulation and completion of the osteotomy in the sagittal plane were evaluated. No significant iatrogenic injuries were detected. The occurrence of minor lesions was 16.6% (2 specimens): one showed a 50% extensor hallucis brevis lesion, and another experienced a complete rupture of the extensor hallucis capsularis tendon. The smallest average distances were observed between portal 1 and dorsomedial digital nerve (3.5 mm) and portal 2 and extensor hallucis capsularis (1.37 mm). This cadaveric study suggests that S-PeICO is anatomically feasible when performed by experienced surgeons, but narrow safety margins and the potential of tendon lesions should be considered.
Mountainous freeways generally deploy safety countermeasures on crash-prone sections to mitigate crash risks from complex combined horizontal-vertical alignments, highlighting the importance of countermeasure evaluation in enhancing traffic safety. While international practices regarding safety improvements for crash-prone roadways have developed quantitative evaluation for implemented countermeasures, the specific design schemes of proposed countermeasures in the design stage usually rely on engineers combining engineering experience to make reasonable inferences based on design specifications, supplemented by crash features and cost-effectiveness. However, it is essential to validate the rationality of such proposed countermeasure design configurations (specifically for countermeasures involving complex driver-geometry interactions) before implementation, to provide quantitative references for engineers to refine their schemes. Driving simulation is a powerful tool for this purpose, as it complements engineering inferences with behavioral-level quantification to validate and refine design schemes. Hence, this study developed a driving simulation-based framework for pre-implementation evaluation of chevron alignment markers and longitudinal speed reduction markings on seven combined alignment types within a 35 km crash-prone section of an operational mountainous freeway in China. Using the high-fidelity Tongji University Driving Simulator, experiments involving 30 participants were conducted to collect vehicle operational data. Paired Wilcoxon signed-rank tests quantitatively evaluated effectiveness using five surrogate safety measures. Results revealed significant section-specific effectiveness: (1) Both countermeasures were most effective on curve-downgrade sections; (2) Neither significantly improved safety on curve-crest or curve-upgrade sections; (3) Both countermeasures were particularly effective for sections with RH < 2500 m, G < |2.0| %, and ΔG ≥ |2.0| %. These findings provide quantitative guidance for engineers to refine section-specific design schemes and resource allocation during the planning stage, ensuring safety countermeasures customized for the unique demands of different combined sections.
Hallux valgus (HV) is a common forefoot deformity. The ideal surgical technique for treating moderate-to-severe hallux valgus (HV) is unclear. Surgical methods that effectively restore the balance of soft tissues around the first metatarsophalangeal (MTP1) joint are necessary. This study compared osteotomy combined with either all-suture anchor-enhanced capsulorrhaphy (AEC) or simple longitudinal capsulorrhaphy (SLC). Due to the different surgical methods from October 2018 to November 2024, ninety-five patients with moderate-to-severe HV were assigned into the AEC group or the SLC group. Demographic data, clinical scores (Manchester-Oxford Foot Questionnaire, American Orthopaedic Foot & Ankle Society Hallux MTP-IP Scoring Scale, Visual Analogue Scale), and radiological parameters(Hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA)) collected before surgery, at 3 months after surgery and at the last follow-up (minimum 6 months, mean 12.41 ± 6.04 months) were retrospectively analyzed, and complications and recurrence were monitored. All patients showed significant improvement in clinical scores and radiological parameters after surgery (p < 0.001). IMA, MOXFQ, AOFAS, and VAS scores were not significantly different between the two groups. At 3 months after the operation, the AEC group showed significantly lower HVA (AEC: 4.7°±3.2°, SLC: 8.5°±2.6°, p < 0.001) and DMAA (AEC: 3.4°±2.8°, SLC: 5.5°±2.1°, p < 0.001) compared to the SLC group. At the last follow-up, the AEC group also showed significantly lower HVA (6.8°±3.8° vs. 11.9°±3.6°, p < 0.001) and DMAA (4.8°±3.3° vs. 7.3°±2.2°, p < 0.001). The AEC group showed a numerically higher rate of normal joint congruency (44/49, 89.8% vs. 34/46, 73.9%, p = 0.044). Both AEC and SLC combined with Chevron-Akin osteotomy were safe and effective techniques for correcting moderate-to-severe HV, although AEC exhibited a greater corrective of HVA and DMAA. Additionally, the joint congruency rate in the AEC group at the last follow-up was nominally higher. Level IV.
Minimally invasive surgery (MIS) for hallux valgus, particularly the minimally invasive chevron and Akin (MICA) technique, is gaining popularity. However, comparative studies between open scarf-Akin osteotomy (SA) and MICA remain limited, particularly for severe cases (ie, hallux valgus angle [HVA] ≥ 40° or intermetatarsal angle [IMA] ≥ 16°). This study aimed to compare the clinical and radiographic outcomes between SA and MICA for severe hallux valgus. We retrospectively reviewed 56 consecutive feet (SA = 33; MICA = 23) treated between January 2019 and January 2023 at a single institution in Hong Kong. Clinical outcomes were evaluated using the American Orthopaedic Foot & Ankle Society (AOFAS) score, Self-Reported Foot and Ankle Score (SEFAS), and visual analog scale (VAS) for pain. Radiographic parameters included the HVA, IMA, distal metatarsal articular angle (DMAA), first metatarsal pronation, and first metatarsal length. Baseline characteristics were broadly comparable, with deformity severity trending higher in MICA. MICA had shorter total operative time and hospital stay (P = .002 and P < .001), although the SA group had a higher frequency of concomitant lesser-toe procedures (85% vs 61%, P = .056), and MICA showed greater improvements in AOFAS and SEFAS (P = .006 and P = .032). In exploratory 2-predictor sensitivity regression adjusting for concomitant lesser-toe procedure, MICA remained associated with shorter operative time (beta = -40.0 min, 95% CI -66.3 to -13.7; P = .003) and shorter length of stay (beta = -2.35 days, 95% CI -3.52 to -1.17; P < .001). After this adjustment, AOFAS improvement was greater in MICA (beta = +6.40, P = .008), whereas SEFAS and VAS improvements were not statistically different. For pronation, SA achieved superior apparent correction: severe postoperative pronation (Wagner 3) was 0% after SA vs 48% after MICA, and baseline-adjusted ordered logistic regression similarly favored SA (MICA vs SA OR 3.75, 95% CI 1.08-13.03; P = .037). Both procedures reliably corrected severe HV deformity. MICA was associated with shorter total operative time and reduced length of stay. In exploratory covariate-adjusted sensitivity models, MICA maintained advantages in operative time and AOFAS scores, whereas between-group differences in SEFAS and angular radiographic outcomes were attenuated or nonsignificant. In contrast, SA demonstrated stronger correction of apparent first-metatarsal pronation, with no apparent residual severe pronation at follow-up compared with MICA. Level III, retrospective cohort study.
Most foot surgeons recognize the difficulties to define each patient's hallux valgus (HV) deformity and to select the most appropriate surgical treatment to achieve the best long term outcome. The goal of this study was to analyze radiologic outcomes after distal chevron metatarsal osteotomy and to identify specific preoperative radiological parameters correlating with radiological recurrence. One hundred twenty patients (134 feet) in patients with symptomatic moderate or severe HV deformity who underwent distal chevron metatarsal osteotomy at our hospital between 2014 and 2019 were included in the present study. Each patient was evaluated preoperatively, postoperatively and at final follow-up by means of radiographs lateral and dorsoplantar views. We examined fourteen radiographic measurements. Data were collected retrospectively. The mean follow-up time was 23.65months (range 6-69.4months). The recurrence rate was 76.1%. Radiologic HV recurrence was defined by a final hallux valgus angle (HVA) equal or greater than 20 degrees. Greater age at time of surgical treatment and preoperative noncongruentI metatarsophalangeal joint were identified as predictors for HV recurrence.
The choice of surgical technique for treating hallux valgus remains debated. Previous studies show favorable outcomes for both open and percutaneous techniques but do not conclude on their superiority. This study compares the functional outcomes of two groups of patients undergoing the minimally invasive Chevron-Akin (MICA) technique and the conventional technique, in short- and mid-term follow-up, using patient-reported outcome scores. A prospective study was conducted on patients with moderate hallux valgus, divided into two groups: conventional Chevron-Akin osteotomy and MICA with fixation using three screws. Pre- and postoperative records were evaluated at 4 weeks, 6 months, and 12 months using the Manchester-Oxford Foot Questionnaire (MOxFQ), the AOFAS scale, and the visual analog scale (VAS). Complications were recorded. Subjective aspects such as surgical technique recommendation and time to return to normal footwear were also assessed. Thirty patients were included in each group. Significant improvements were observed in functional scales post-surgery, but no differences were found between techniques. All patients recommended the surgery performed and returned to wearing normal footwear between the third and fourth postoperative weeks. Both techniques show similar short- and mid-term outcomes and are effective in treating moderate hallux valgus. The choice of technique should depend on the surgeon's skills and experience.
The choice of surgical technique for treating hallux valgus remains debated. Previous studies show favorable outcomes for both open and percutaneous techniques but do not conclude on their superiority. This study compares the functional outcomes of two groups of patients undergoing the minimally invasive Chevron-Akin (MICA) technique and the conventional technique, in short- and mid-term follow-up, using patient-reported outcome scores. A prospective study was conducted on patients with moderate hallux valgus, divided into two groups: conventional Chevron-Akin osteotomy and MICA with fixation using three screws. Pre- and postoperative records were evaluated at 4weeks, 6months, and 12months using the Manchester-Oxford Foot Questionnaire (MOxFQ), the AOFAS scale, and the visual analog scale (VAS). Complications were recorded. Subjective aspects such as surgical technique recommendation and time to return to normal footwear were also assessed. Thirty patients were included in each group. Significant improvements were observed in functional scales post-surgery, but no differences were found between techniques. All patients recommended the surgery performed and returned to wearing normal footwear between the third and fourth postoperative weeks. Both techniques show similar short- and mid-term outcomes and are effective in treating moderate hallux valgus. The choice of technique should depend on the surgeon's skills and experience.
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Graphene nanoribbons (GNRs) are highly versatile materials due to their unique electronic, magnetic, and optical properties, which can be precisely tuned by controlling their width, edge structure, and topology. We report the on-surface synthesis and characterization of a straight N = 15 armchair GNR with periodic [18]annulene nanopores (15-pGNR). It serves as a structural link between two well-established GNRs: the pristine N = 15 armchair GNR without pores (15-AGNR) and the chevron GNR (cGNR). With the addition of the 15-pGNR reported in this study, these three GNRs form a rare experimentally accessible series of ribbons, in which the evolution of electronic properties can be tracked upon progressive carving of a basic 15-AGNR: first, by creating periodic nanopores to form 15-pGNR and then by extending the pore area and producing meandering cGNR. We have designed a molecular precursor for the 15-pGNR and grown the nanoribbons on single-crystal gold substrates by on-surface synthesis in ultra-high vacuum (UHV) conditions. The atomically precise structure of 15-pGNR was confirmed by scanning tunneling microscopy (STM) and non-contact atomic force microscopy (nc-AFM). The band gap of 15-pGNR was studied by scanning tunneling spectroscopy (STS) and dI/dV mapping, and the occupied electronic levels were investigated by angle-resolved photoemission spectroscopy (ARPES). A theoretical and experimental comparison of 15-pGNRs, 15-AGNRs, and cGNRs demonstrates that the introduction of periodic nanopores into 15-AGNR leads to a more than 2-fold increase in its band gap. In contrast, the band gaps of 15-pGNR and cGNR differ only by about 15%. Such band gap increase can be qualitatively understood to arise from two combined effects, the periodic perforation of the graphene lattice and the confinement effect induced by the GNR width.
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Hallux valgus is a common forefoot deformity that alters forefoot loading and often leads to secondary complications such as intractable plantar keratosis beneath the second metatarsal head. Although the link between hallux valgus and intractable plantar keratosis is recognized, whether two procedures that correct intractable plantar keratosis through different mechanisms-minimally invasive chevron Akin osteotomy (MICA) with first metatarsal head lowering and conventional MICA combined with second distal metatarsal minimally invasive osteotomy (DMMO)-have differential effects on symptom improvement has not, to our knowledge, been assessed. (1) Do patients with hallux valgus and intractable plantar keratosis beneath the second metatarsal head have distinctive radiographic features compared with those with hallux valgus alone? (2) How do the two different surgical strategies (MICA with first metatarsal head lowering versus MICA with second DMMO) differ in terms of lesser metatarsal head height and intractable plantar keratosis resolution? (3) What are the differences in the Foot and Ankle Ability Measure (FAAM), including the subscales for activities of daily living (ADL) and sports, and other complications between these techniques? Between January 2017 and June 2024, two surgeons treated 194 feet with hallux valgus using MICA after predefined exclusions. Of these, 113 feet did not have preoperative intractable plantar keratosis beneath the second metatarsal head; after excluding 13 feet without a minimum 1-year follow-up, 100 feet were included as a reference cohort. The remaining 81 feet had preoperative intractable plantar keratosis beneath the second metatarsal head and constituted the primary study cohort. Within this group, 34 feet underwent MICA with first metatarsal head lowering and 47 feet underwent MICA with second DMMO. From 2017 to 2020, MICA with second DMMO was routinely used for patients with intractable plantar keratosis beneath the second metatarsal head. Beginning in 2021, we gradually incorporated first metatarsal head lowering, and both procedures were used thereafter based on first-ray sagittal alignment, intraoperative loading patterns, and patient preference. After excluding feet without a minimum 1-year follow-up, 30 feet in the MICA with first metatarsal head lowering group and 42 feet in the MICA with second DMMO group were available for comparative analysis. There was no differential loss to follow-up between study groups for analysis in this retrospective study (12% [4 of 34] and 11% [5 of 47]). Follow-up completeness was comparable between groups, with similar mean ± SD follow-up durations (15 ± 3 months versus 17 ± 4 months). The study population had a mean age of 57 years and was predominantly female (approximately 90%), with comparable demographic characteristics between groups. To answer our first study question, we compared preoperative radiographic characteristics-including hallux valgus angle, first-to-second intermetatarsal angle, and the relative length and height of the lesser metatarsals-between patients with and without intractable plantar keratosis beneath the second metatarsal head. To address our second study question, we evaluated the changes in the relative height of the lesser metatarsals and postoperative resolution of intractable plantar keratosis following two different techniques. To answer our third study question, we compared the FAAM-ADL and sports scores and procedure-related complications between the two surgical techniques. All p values were adjusted using the Holm-Bonferroni method. Because some patients contributed bilateral feet, analyses were adjusted for the nonindependence of observations using a mixed-effects model with patient as a random effect; within-patient correlation was negligible, supporting inclusion of both feet in the analysis. Patients with hallux valgus and intractable plantar keratosis beneath the second metatarsal head had a larger hallux valgus angle (mean ± SD 35° ± 8° versus 31° ± 8°, mean difference 4° [95% confidence interval (CI) 1° to 5°]; p < 0.001) and lower second (3 ± 2 mm versus 1 ± 2 mm, mean difference 2 mm [95% CI 1.5 to 2.7]; p < 0.001) and third metatarsal heads (4 ± 2 mm versus 2 ± 1 mm, mean difference 2 mm [95% CI 1.3 to 2.5]; p < 0.001) than those without intractable plantar keratosis. Both procedures resolved intractable plantar keratosis at similar percentages (87% [26 of 30] versus 91% [38 of 42], OR 0.7 [95% CI 0.2 to 3.0]; p = 0.71). However, MICA with first metatarsal head lowering elevated both the second (-2 mm [95% CI -4.2 to 0]) and third metatarsal heads (-2 mm [95% CI -3.8 to 0]), whereas MICA with second DMMO elevated the second (-2 mm [95% CI -4.7 to -0.1]) but lowered the third (1 mm [95% CI -0.4 to 2.4]), producing a between-group difference of 3 mm (95% CI 1.9 to 3.9; p < 0.001). Functional outcomes improved in both groups, but MICA with first metatarsal head lowering showed greater improvement in FAAM-sports scores (24% versus 21%, mean difference 3% [95% CI 2% to 7%]; p = 0.04). Postoperatively, MICA with second DMMO resulted in new intractable plantar keratosis beneath the third metatarsal head (10% [4 of 42]). In contrast, first metatarsal head lowering more frequently caused plantar discomfort beneath the first metatarsal head (17% [5 of 30]). Accurate assessment of metatarsal height in the axial plane is essential when surgically treating hallux valgus with intractable plantar keratosis. Although both adjunctive procedures-first metatarsal head lowering and second DMMO-effectively improved intractable plantar keratosis, they differ in their corrective mechanisms and associated risks: adding only second DMMO may predispose patients to new keratosis beneath the third metatarsal head, whereas lowering the first metatarsal head may result in postoperative plantar discomfort beneath the first metatarsal head. Level III, therapeutic study.
The medial malleolar osteotomy is required in some cases of osteochondral lesions, bone tumors, and fractures of the medial talar dome for surgical access. The literature is uncertain about which type of osteotomy and fixation is best. The objective of this study was to compare, in cadaveric specimens, the oblique and chevron medial malleolar osteotomies and their fixation with either 2 or 3 screws, evaluating the possibility of articular displacement. We hypothesize that the chevron osteotomy results in a lower chance of articular displacement at the end of the procedure than the oblique osteotomy. Our second hypothesis is that fixation with 3 screws also reduces the risk of articular displacement compared with 2 screws. Forty anatomical fresh‑frozen specimens were analyzed and divided into 4 groups (10 per group): oblique osteotomy fixed with 2 or 3 screws and chevron osteotomy fixed with 2 or 3 screws. One fracture occurred in the chevron osteotomy group with 3 screws, leaving 39 specimens for analysis. After osteotomies and fixation, the talus was removed, and articular displacement (step‑off) of the distal tibia was assessed using a digital caliper. The results indicated a lower incidence of articular displacement in chevron osteotomy (21.1%) compared with oblique osteotomy (50%). Fixation with 3 screws showed a lower rate of incongruence (21.1%) compared with 2 screws (50%). When the type of osteotomy and fixation were combined the chevron osteotomy fixed with 3 screws had no measurable articular displacement in this cadaveric model. In this cadaveric surgical technique model, a chevron medial malleolar osteotomy fixed with 3 screws showed no measurable articular displacement and overall had a lower risk of articular step‑off compared with oblique osteotomy and 2‑screw fixation.