Category: Bunion; Midfoot/Forefoot Introduction/Purpose: The hallux valgus surgery can be associated with first metatarsal shortening increasing the occurrence of postoperative transfer metatarsalgia. There is no consensus regarding the acceptable degree of shortening and it relation with metatarsalgia. Besides shortening, there are other factors that could be associated with metatarsalgia like sagittal alignment, deformity correction and surgical technique. The primary objective of the study was to analyze the relative first metatarsal length variation following hallux valgus surgery and its association with postoperative metatarsalgia. The secondary objective was to analyze de first metatarsal length variation and postoperative metatarsalgia by type of surgical technique. Methods: We performed a retrospective cohort study of all adult patients who underwent hallux valgus corrective surgery between 2017 and 2019 in our clinical center. The inclusion criteria were patients with at least 1 year follow up, without simultaneous lesser metatarsal procedures or referred preoperative metatarsalgia, and that could be contacted for the study. For the analysis we evaluated the incidence of post operative metatarsalgia via phone call and the relation with first metatarsal length variation which was determined by the relative first metatarsal length (RML) measurement according to Nilsonnne/Morton technique. All radiographs were measured by two foot and ankle surgeons. We analyzed the association of postoperative metatarsalgia according to the RML variation. A total of 85 feet were included in the study, with 5 different surgical techniques (16 promo, 19 chevron, 18 scarf, 14 lapidus and 18 MICA) Results: The average preoperative and postoperative RML were + 0.03 mm and -2.92 mm, respectively. The average global postoperative RML shortening variation was -2.98 mm (min -10, max +5), and by surgical technique were -4.09 mm, -3.11 mm, - 3.05 mm, -2.93 mm and -1 mm for lapidus, chevron, scarf, promo and MICA, respectively. Only 9.1% of patients presented postoperative metatarsalgia, and the average postoperative RML shortening in those patients was - 4.63mm (min 0, max -10). There was a statistically significant correlation between RML shortening and postoperative metatarsalgia in patients with shortening higher or equal to 4 mm (p value <0.05). In relation to the 8 patients with metatarsalgia, 3 of them had a postoperative elevated first metatarsal (1 promo, 1 chevron and 1 lapidus) and 1 had recurrence of the deformity associated (lapidus). Conclusion: We found a postoperative RML shortening in hallux valgus correction, regardless of the selected surgical technique. The RML shortening was associated with postoperative metatarsalgia in patients with shortening higher or equal to 4 mm. However, in some of those patients, we found other concomitant factors, such as first metatarsal elevation or recurrence of the deformity. Therefore, even though we consider that shortening of the first metatarsal is an important factor, it seems relevant to assess all other potentials factors in patients with postoperative metatarsalgia.

Category: Bunion; Other Introduction/Purpose: Recently, minimally invasive surgery for hallux valgus correction has regained popularity. The minimally invasive Chevron and Akin (MICA), has been proved to be as satisfactory for patients as conventional open techniques. However, due to its design, it is difficult to correct the coronal plane malalignment, which could lead to the recurrence of the deformity. Instead, a Bösch-type osteotomy allows multiplanar correction, and with an upgrade in its fixation we can create a stable third- generation percutaneous osteotomy. We report our early results using the minimally invasive Bösch and Akin osteotomy (MIBA). Methods: This was a prospective case series of our first 40 patients (41 feet) undergoing MIBA procedure. Outcome measures included the Manchester-Oxford Foot Questionnaire (MOXFQ), the AOFAS Forefoot Score, and the visual analog scale (VAS) for pain assessment. Radiographic measures included the hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA) and the pronation of the metatarsal. All complications and emitted radiation dosage were reported as well. Results: At 12 months MOXFQ and AOFAS improved from 54.8 to 0.66 (p=0) and 39.1 to 99.2 (p=0), respectively. The mean preoperative VAS was 5.8, and improved during the first week to 1.3 (p<0.05). There was also a significant improvement in all radiographic parameters. We had two significant and five minor complications. Conclusion: The MIBA procedure is a safe and effective option to achieve a multiplanar hallux valgus correction.

Category: Lesser Toes; Hindfoot Introduction/Purpose: Distal metatarsal osteotomies for metatarsalgia are one of the most frequent procedures in foot and ankle surgery, however, sometimes their results are not so favorable, with sequelae such as floating toe or loss of toe grip. The open modified Weil osteotomy (OWO) is considered the first alternative in metatarsalgia cases for many surgeons, nevertheless, in recent years, minimally invasive surgery (MIS) has become an attractive alternative for the management of this pathology. To date, there is scarce literature that compares clinical and functional results between both techniques. The objective of this study is to compare the clinical and functional outcomes between OWO and minimally invasive distal metatarsal osteotomy (DMMO), with and without lesser toe procedures. Methods: We performed a retrospective review of 77 patients who underwent OWO or DMMO, with at least 12 month follow up. We excluded patients with incomplete data, previous forefoot surgery, and patients with neuromuscular or rheumatological diseases. Our main outcome was to evaluate the presence of floating toe. Our secondary outcomes were to evaluate toe grip strength (paper pullout test), functional scores (LEFS and AOFAS) and satisfaction. All patients were clinically evaluated by one foot and ankle surgeon who did not participate in any of the surgical procedures. Statistical analysis was performed using Student's t-test, Fisher's test, and Chi-square. Results: 77 patients (188 rays) were included. 120 rays received OWO, and 68 rays DMMO. 95% women, with a mean age of 57 years. The mean follow-up was 39.4 months. The floating toe incidence was 56.7% in the OWO group (67.3% when a DuVries procedure was added), which was significantly higher (p=0.001) than the 25% in the DMMO group (37.9% when P1 MIS osteotomy was added). When comparing lesser toe grip strength between both groups, the DMMO patients had significantly greater grip strength (p=001) Significant differences were obtained between both groups when comparing satisfaction (p=0.04), LEFS (p=0.001), and AOFAS scores (p=0.001), being better in the DMMO group. Conclusion: In our series, the DMMO procedure had significantly lower incidence of floating toe, greater toe grip strength, better functional outcomes and superior satisfaction scores than the OWO. When a bone procedure in the lesser toe is added (MIS osteotomy or DuVries) the floating toe incidence is increased, but not with statistical significance.

Category: Basic Sciences/Biologics; Bunion Introduction/Purpose: Hallux valgus minimally invasive surgery (MIS) is becoming more common due to its good clinical and functional results. Third-generation MIS surgery uses screw fixation that is dependent on the bone density of the first metatarsal head (FMH) for optimal screw purchase. There is no information regarding areas of higher bone density (BMD) in the FMH that suggest a stronger area of fixation, nor has it been described whether it varies between different age groups or with gender. The objective of this study is to determine the BMD within four quadrants of the FMH. This finding could lead to identifying the ideal trajectory for screw placement. In addition, we evaluate BMD variation by age and gender. Methods: Transversal study. From our CT scan database, we obtained 40 patients with no previous history of first metatarsal fractures, pre existing hardware, foot surgery or osteoporosis. We divided the patients into 4 groups, each group containing 5 male and 5 female patients: group 1: <30 years, group 2: 31-45 years, group 3: 46-60 years, group 4: > 60 years. The main outcome is to evaluate the association between BMD in each FMH quadrant. Secondary outcomes are to identify any differences in BMD between gender and age groups. According to what has been previously discussed in the literature, two evaluators measured the Hounsfield units (HU) of each quadrant on a coronal cut located 10 mm proximal to the metatarsophalangeal joint using the Merge PACS system. Measures were averaged. Statistical analysis was performed by measuring normality with the Shapiro-Wilks test, and the ANOVA, Student's t-test, and Mann-Whitney U test. Results: The dorsolateral (DL) quadrant had the highest BMD (353.9hu) of all quadrants, followed by the lateral plantar (LP: 302.4hu), medial plantar (MP: 264.1hu), and dorsomedial (DM: 247.6hu) (p=0.001).When comparing the groups by age, DL (p=0.01) and LP (p=0.01) quadrants had significantly greater BMD in groups 1 and 2 (< 45 years) than groups 3 and 4 (> 45 years).When comparing BMD by gender, differences were only obtained in the group 4, in which mens had greater BMD in the DM (p=0.03), DL (p=0.02), and LP (p=0.01) quadrants.An significant inverse association between age and BMD was obtained for the DL (P=0.004) and MP (P=0.03) quadrants. Conclusion: There are differences in BMD between the quadrants of the first metatarsal head, with the greatest BMD being in the dorsolateral region at any age. BMD decreased proportionally with increasing age in the DL and MP quadrants. At the same age, there are no significant differences between gender, except in patients >60 years, where women have lower BMD in almost all quadrants.

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: Recently, minimally invasive surgery for hallux valgus correction has regained popularity. The minimally invasive Chevron and Akin (MICA), has been proved to be as satisfactory for patients as conventional open techniques. However, due to its design, it is difficult to correct the coronal plane malalignment, which could lead to the recurrence of the deformity. Instead, a Bösch-type osteotomy allows multiplanar correction, and with an upgrade in its fixation we can create a stable third- generation percutaneous osteotomy. We report our first 100 patients results using the minimally invasive Bösch and Akin osteotomy (MIBA). Methods: This was a prospective case series of our first 100 patients (137 feet) undergoing MIBA procedure. Outcome measures included the Manchester-Oxford Foot Questionnaire (MOXFQ), the AOFAS Forefoot Score, and the visual analog scale (VAS) for pain assessment. There was also a significant improvement in all radiographic parameters (p < 0.05). Mean HVA decreased from 30.5° to 7.8°, mean IMA decreased from 13° to 4.5°, and the mean DMAA decreased from 13.8° to 4.0° (p<0.05). All complications and emitted radiation dosage were reported as well. Results: At 12 months MOXFQ and AOFAS improved from 57.3 to 0.73 (p=0.00) and 45.2 to 99.2 (p=0.00), respectively. The mean preoperative VAS was 4.6, and improved during the first week to 1.3 (p<0.05). There was also a significant improvement in all radiographic parameters. We had three significant and 13 minor complications. Conclusion: The MIBA procedure is a safe and effective option to achieve a multiplanar hallux valgus correction.