Aims. The first metatarsal pronation deformity of hallux valgus feet is widely recognized. However, its assessment relies mostly on 3D standing CT scans. Two radiological signs, the first metatarsal round head (RH) and inferior tuberosity position (ITP), have been described, but are seldom used to aid in diagnosis. This study was undertaken to determine the reliability and validity of these two signs for a more convenient and affordable preoperative assessment and postoperative comparison. Methods. A total of 200 feet were randomly selected from the radiograph archives of a foot and ankle clinic. An anteroposterior view of both feet was taken while standing on the same x-ray platform. The intermetatarsal angle (IMA), metatarsophalangeal angle (MPA), medial sesamoid position, RH, and ITP signs were assessed for statistical analysis. Results. There were 127 feet with an IMA > 9°. Both RH and ITP severities correlated significantly with IMA severity. RH and ITP were also significantly associated with each other, and the pronation deformities of these feet are probably related to extrinsic factors. There were also feet with discrepancies between their RH and ITP severities, possibly due to intrinsic torsion of the first metatarsal. Conclusion. Both RH and ITP are reliable first metatarsal pronation signs correlating to the metatarsus primus varus deformity of hallux valgus feet. They should be used more for preoperative and postoperative assessment. Cite this article: Bone Jt Open 2024;5(11):1037–1040

Aims. The purpose of this study is to examine the adductus impact on the second metatarsal by the nonosteotomy nonarthrodesis syndesmosis procedure for the hallux valgus deformity correction, and how it would affect the mechanical function of the forefoot in walking. For correcting the metatarsus primus varus deformity of hallux valgus feet, the syndesmosis procedure binds first metatarsal to the second metatarsal with intermetatarsal cerclage sutures. Methods. We reviewed clinical records of a single surgical practice from its entire 2014 calendar year. In total, 71 patients (121 surgical feet) qualified for the study with a mean follow-up of 20.3 months (SD 6.2). We measured their metatarsus adductus angle with the Sgarlato’s method (SMAA), and the intermetatarsal angle (IMA) and metatarsophalangeal angle (MPA) with Hardy’s mid axial method. We also assessed their American Orthopaedic Foot & Ankle Society (AOFAS) clinical scale score, and photographic and pedobarographic images for clinical function results. Results. SMAA increased from preoperative 15.9° (SD 4.9°) to 17.2° (5.0°) (p < 0.001). IMA and MPA corrected from 14.6° (SD 3.3°) and 31.9° (SD 8.0°) to 7.2° (SD 2.2°) and 18.8° (SD 6.4°) (p < 0.001), respectively. AOFAS score improved from 66.8 (SD 12.0) to 96.1 (SD 8.0) points (p < 0.001). Overall, 98% (119/121) of feet with preoperative plantar calluses had them disappeared or noticeably subsided, and 93% (113/121) of feet demonstrated pedobarographic medialization of forefoot force in walking. We reported all complications. Conclusion. This study, for the first time, reported the previously unknown metatarsus adductus side-effect of the syndesmosis procedure. However, it did not compromise function restoration of the forefoot by evidence of our patients' plantar callus and pedobarographic findings. Level of Clinical Evidence: III. Cite this article: Bone Jt Open 2021;2(3):174–180

Hallux varus is a rare cause of pain in the foot mostly occurring after failed hallux valgus surgery. We reviewed 12 patients with unilateral hallux varus treated with soft tissue techniques (4x), arthrodesis of the first metatarso-phalangeal joint (3x) or with a distal chevron osteotomy (5x) with medial transposition of the first metatarsal head and reconstruction of the soft tissues on the lateral side of the metatarsophalangeal joint. 10 patients had previous hallux valgus surgery, in 2 cases the deformities were of unknown origin. 1 male and 11 female patients were followed up on average 26.4 months postoperatively. AOFAS hallux score improved from 46 (range 10–75) to 86 (range 72–95) points. The metatarsophalangeal angle measured with the center-head to center-base method was reduced from −16.1° (range −35° to −8°) to 5.1° (range −15° to 21°). The intermetatarsal angle increased from 5.8° (0–11°) t o 10.5° (0–19°). All patients were subjectively satisfied with the procedure. Our results indicate that joint preserving operation techniques are viable methods in the correction of mild and moderate symptomatic hallux varus deformities. Mild remaining varus deformities are well tolerated. In case of severe varus deformity or major signs of osteoarthritis in the first metatarsophalangeal joint MTP arthrodesis provides good results

Purpose of the study: Basimetatarsal osteotomy to correct hallux valgus deformity by subtraction of a lateral wedge does not take into account the distal angle of the first metatarsal (DMMA). The purpose of this study was to demonstrate that the preoperative DMMA has an effect on the correction of the metatarsophalangeal angle and the duration of the result. Material and methods: This retrospective study included 76 patients, mean age 58 years (84 feet). The M1P1 angle of the first ray was 34 on average, the DMMA 10 (two-thirds of the patients had a DMAA > 10. The same operator used the same technique for all procedures: lateral wedge osteotomy of the base of the first metatarsal with metatarsophalangeal release. Basal osteotomy of the first phalanx was performed for severe deformity. Radiographic measures were made on the dorsoplantar anteroposterior images in the weight-bearing condition preoperatively, at four weeks and at last follow-up. All images were read by an independent observer. Mean follow-up was 11 months. The DMMA measurement was the angle between the distal joint surface of the first metatarsal and the alignment of its diaphysis. Results: Mean postoperative correction of the hallux valgus was 25 with a mean M1P1 of 9. This result remained stable without loss of correction at last follow-up. The mean postoperative DMAA was 10 and remained unchanged. Discussion: Determination of the DMAA can be difficult because of preoperative pronation of the forefoot, compromising the reliability of the measurement. The literature also reports intraobserver and interobserver variability of this angle. Mean follow-up was not greater than one year, but the loss of correction generally occurred during the first six postoperative months. The operative technique enabled sufficient and stable correction over time. A pathological value for DMAA, even if large and uncorrected, does not prevent a good correction of the M1P1 angle and to maintain that correction. The clinical result is also the same irrespective of the preoperative DMMA. Conclusion: Wedge osteotomy of the base of the first metatarsal is a reliable procedure for the treatment of hallux valgus. The value of the DMAA has no effect, in our experience, on the quality of the correction, or on the duration of the result

Introduction and Objectives: The technique modified by Regnauld makes it possible to correct the MTP angle and the DASA, shorten the first phalange preserving the MTP joint, and its articular congruence and functionality. Assessment of results at 2 years follow-up of 147 cases treated with this technique. Materials and Methods: Causes: Hallux Valgus 111; Hallux Rigidus 36. Sex: Women 114, men 33. mean age 70 years. Associated surgery: Proximal chevron-type osteotomy of the first MTT: 23; Scarft-type diaphyseal osteotomy: 1; osteotomy of the base of the first MTT: 11; double osteotomy: 5; subcapital Weils-type osteotomy: 15. Preoperative AOFAS test score 39.6. Mean follow-up 2.3 years. Pre and postoperative measurement of metatarsophalangeal angles. Postoperative assessment at 1 month, 6 m, 1 year and 2 years with X-ray, AOFAS scale. Results: Postoperative assessment using the AOFAS scale: < 1 month: 65, < 6 months: 78, < 1 year: 89, < 2 year: 82. AOFAS scale at 2 years: Moderate pain 2%. Narrow shoes 11%. Moderate MTP restriction 35%. Severe MTP restriction 2%. Infrequent mobility with severe IP restriction 9%. Asymptomatic malalignment 5%. Subjective assessment: Very satisfied 25%. Satisfied 68%. Not very satisfied 5% (occasional pain). Unsatisfied 2% (daily pain). The evolution of the values of the MTP angle were: preoperative MTP angle 34.7°, MTP angle 4 weeks postoperatively 8.1°, MTP angle at 1 year 14.7°, MTP angle at 2 years18.1°. Discussion and Conclusions: Satisfactory results (93%). This technique corrects the MTP angle, preserves the MTF joint and makes it possible to associate with it other surgical techniques to modify the intermetatarsal angle. By preserving the MTP joint we prevent early evolution of hallux rigidus. Very little loss of MTP correction at 2 years (10°), with no clinical correlation

Purpose: We present a new basilar osteotomy we have called TRADE. This osteotomy uses a single flat-oblique cut to achieve lateral basimetatarsal translation with lowering and derotation. Material: The ATLAS system was used. This system includes a four point axial staple for the phalanx and a staple plate for the metatarsus. The staple plaque was designed around the tibial osteotomy plates. It is composed of a straight plate screwed to the diaphysis. It carries two spikes at variable angles that penetrate the epiphysis perpendicularly. The desired angle is measured peroperatively and the plate is bent appropriately using a graduated template. Application of the staple plate then imposes the exact correction. Method: We tested the basal osteotomy on five anatomic hallux valgus specimens, including one fresh specimen. We also reviewed 125 files of patients who underwent double flat-oblique osteotomy fixed with the system. Each type of hallux valgus was defined pre- and postoperatively, clinically and radiologically: four views, three to determine the orientation of the deformity in the three planes and a fourth one to assess reducibility. The operative technique involved four times. The first was often not necessary: lateral release, depending on the degree of retraction on the reduction view. The second time, the medial chevron osteotomy of the first phalanx, was almost always needed. The third time was the basimetatarsal ostetomy; the flat-oblique direction was determined from an abacus taking into account three variables: varus, rotation, lowering. The fourth time, exostosectomy with capsule retention, was not always needed. The patients experienced little pain postoperatively when the procedure was limited to the two osteotomies without affecting the soft tissues. For the 125 cases, intermetatarsal deviation was improved from 18°67 to 6°86, metatarsophalangeal angle from 33°59 to 11° and pronation from 13°42 to 0°72. Conclusion: The TRADE osteotomy allows correction in all three planes. Correction is particularly precise in the frontal plane where the risk of undercorrection and recurrence is high. The procedure can be modulated according to the radiological presentation and can be limited to two osteotomies using short skin incisions without opening the joint

Purpose: All displacements can be described with x, y, z coordinates. We propose an anterior view of the first metatarsal associated with a peroperative test to determine the precise position in the frontal plane, both statically and dynamically. Lateral release is an important step in surgical treatment of hallux valgus. Both the extent of release and the potential benefit of no release must be carefully evaluated. We propose a view allowing an assessment of the metatarsophalangeal reducibility. Material and method: Peroperative test. This test explores cuneometatarsal laxity. We conducted a prospective study in 100 cases. A 12/100 pin was used to immobilise the first cuneiform and a 20/100 pin was placed in the base of the first metatarsal. A third distal pin in the neck was used to pivot the bone on its axis. A small protractor was used to measure the angle by projection with ±2.5° precision. Modified Guntz view. This is a weight-bearing anterior view of the first metatarsal. The cassette is positioned posteriorly. The patient stands with the heal raised 40 mm on a 20mmx20mm plexiglass bar. The metatarsal diaphysis must appear perfectly vertical. An isosceles triangle is constructed on the articular facets; the base of the triangle is perfectly horizontal and defines the pronation-supination angle. We made 100 measurements and checked correlation with the peroperative test. Reduction view. A Zimmer brace was used to reduce the varus metatarsus and adduct the toe. The metatarsophalangeal angle and the position of the sesamoids were used to assess reducibility. Results: Pronation and/or pronation instability was = 10° in 96% of the patients. The reduction view enabled classifiation by three grades of reducibility. Discussion: Our contribution is determining for correction of displacements taking into account the frontal plane. No other study has shown so clearly the existence of metatarsal pronation. We also confirmed the presence of a large proportion of cuneometatarsal instability. The extent of lateral release or the potential benefit of no release can now be assessed. Conclusion: A certain number of failures have undoubtedly been related to neglect of the parameters studied here. It is indispensable to explore the frontal plane and the dynamic parameters before establishing indications for new flat-oblique metatarsal osteotomies using conventional or minimally invasive techniques

Introduction. Osteoarthritis commonly affects the first metatarsophalangeal joint. Stress across this joint has been postulated to increase the incidence of osteoarthritis. Certain foot structures have been associated with a higher incidence of osteoarthritis of the big toe. Utilizing finite elemental analysis, bone stress across the first metatarsophalangeal joint was calculated during mid stance phase of gait and compared in different foot structures. Method. A geometrically accurate three dimensional model of the first metatarsophalangeal joint was created utilising a high resolution 7 tesla MRI and Mimics v14 imaging software. Planus, rectus and cavus feet were simulated by varying the metatarsophalangeal declination angle to 10.1, 20.2 and 30.7 degrees, respectively. A non-manfold computer aided design technique in Mimics v14.2 and finite element method in ANSYS v12 FE were utilised to create the boundary conditions, representing the double support stance phase of gait. Using information from 61 asymptomatic patients with different foot types walking over a Novel emed-x plantar pressure measuring system, plantar loading conditions were applied. Finite elemental analysis was used to predict stress in the first metatarsophalangeal joint in the different foot types. Results. The peak stresses in the distal first metatarsophalangeal joint cartilage were 1.1×10(6) Pa, 6.0×10(5) Pa and 9.7×10(5) Pa for planus, rectus and cavus foot types, respectively. This corresponds to 83.3 percent and 61.6 percent increases in first metatarsophalangeal joint contact stress for the planus and cavus feet relative to the rectus foot. Conclusion. The results suggest there is a higher contact stress of the first metatarsophalangeal joint in patients with pes planus and pes cavus compared to the rectus foot. This may account for the increase risk of first metatarsophalangeal joint osteoarthritis in patients with pes planus. Further work has been initiated utilising this model to measure first metatarsophalangeal joint stress with different hindfoot loading