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

Introduction. Recurrence after surgical correction of hallux valgus may be related to coronal rotation of the first metatarsal. The scarf osteotomy is a commonly used procedure for correcting hallux valgus but has limited ability to correct rotation. Using weightbearing computed tomography (WBCT), we aimed to measure the coronal rotation of the first metatarsal before and after a scarf osteotomy, and correlate these to clinical outcome scores. Methods. We retrospectively analyzed 16 feet (15 patients) who had a WBCT before and after scarf osteotomy for hallux valgus correction. On both scans, hallux valgus angle (HVA), intermetatarsal angle, and anteroposterior/lateral talus-first metatarsal angle were measured using digitally reconstructed radiographs. Metatarsal pronation (MPA), alpha angle, sesamoid rotation angle and sesamoid position was measured on standardized coronal CT slices. Preoperative and postoperative(12 months) clinical outcome scores(MOxFQ and VAS) were captured. Results. Mean HVA was 28.6±10.1 degrees preoperatively and 12.1±7.7 degrees postoperatively. Mean IMA was 13.7±3.8 degrees preoperatively and 7.5±3.0 degrees postoperatively. Before and after surgery, there were no significant differences in MPA (11.4±7.7 and 11.4±9.9 degrees, respectively; p = 0.75) or alpha angle (10.9±8.0 and 10.7±13.1 degrees, respectively; p = 0.83). There were significant improvements in SRA (26.4±10.2 and 15.7±10.2 degrees, respectively; p = 0.03) and sesamoid position (1.4±1.0 and 0.6±0.6, respectively; p = 0.04) after a scarf osteotomy. There were significant improvements in all outcome scores after surgery. Poorer outcome scores correlated with greater postoperative MPA and alpha angles (r= 0.76 (p = 0.02) and 0.67 (p = 0.03), respectively). Conclusion. A scarf osteotomy does not correct first metatarsal coronal rotation, and worse outcomes are linked to greater metatarsal rotation. Rotation of the metatarsal needs to be measured and considered when planning hallux valgus surgery. Further work is needed to compare postoperative outcomes with rotational osteotomies and modified Lapidus procedures when addressing rotation

Metatarsalgia is a recognised complication following iatrogenic shortening of the first metatarsal in the management of hallux valgus. The traditional surgical treatment is by shortening osteotomies of the lesser metatarsals. We describe the results of lengthening of iatrogenic first brachymetatarsia in 16 females. A Scarf-type osteotomy was used in the first four cases and a step-cut of equal thicknesses along the axis of the first metatarsal was performed in the others. The mean follow-up was 21 months (19 to 26). Relief of metatarsalgia was obtained in the six patients in whom 10 mm of lengthening had been achieved, compared to only 50% relief in those where less than 8 mm of lengthening had been gained. One-stage step-cut lengthening osteotomy of the first metatarsal may be preferable to shortening osteotomies of the lesser metatarsals in the treatment of metatarsalgia following surgical shortening of the first metatarsal

We studied a cohort of 26 diabetic patients with chronic ulceration under the first metatarsal head treated by a modified Jones extensor hallucis longus and a flexor hallucis longus transfer. If the first metatarsal was still plantar flexed following these two transfers, a peroneus longus to the peroneus brevis tendon transfer was also performed. Finally, if ankle dorsiflexion was < 5° with the knee extended, a Strayer-type gastrocnemius recession was performed. The mean duration of chronic ulceration despite a minimum of six months’ conservative care was 16.2 months (6 to 31). A total of 23 of the 26 patients were available for follow-up at a mean of 39.6 months (12 to 61) after surgery. All except one achieved complete ulcer healing at a mean of 4.4 weeks (2 to 8) after surgery, and there was no recurrence of ulceration under the first metatarsal. We believe that tendon balancing using modified Jones extensor hallucis longus and flexor hallucis longus transfers, associated in selected cases with a peroneus longus to brevis transfer and/or Strayer procedure, can promote rapid and sustained healing of chronic diabetic ulcers under the first metatarsal head

Introduction. Hallux valgus is a common orthopaedic complaint with multiple surgical options. There are many methods available for assessing whether sufficient translation of the first metatarsal can be achieved with a metatarsal translational osteotomy alone. None of the current methods take into account the breadth of the metatarsal. With current PACS technology a radiograph can be zoomed to any size and we postulate that by using the surgeon's thumb (or any suitable digit), as a sizing tool, a safe clinical decision can be made concerning whether a translational metatarsal osteotomy alone will provide sufficient correction. Method. We reviewed the preoperative radiographs (weightbearing AP) of twenty patients who had scarf and akin osteotomies and twenty patients with a deformity too great for scarf and akin osteotomies. The senior author (CC) taught the rule of thumb to one consultant and two registrars (total two registrars and two consultants). The radiographs were blindly randomised and the participants assessed each radiograph and decided whether sufficient translation could be achieved with a translational metatarsal osteotomy alone. The process was repeated three months later. Twenty patients were deemed sufficient for intra-user variability and significance based on a recent JBJS(A) article concerning radiographic measurements post proximal crescentic osteotomy (Shima et al. 2009). Results. Good inter- and intra- user variability was demonstrated and using the rule of thumb is a safe way of determining whether a distal osteotomy alone will provide sufficient correction

When performing scarf osteotomies some surgeons use intraoperative radiography and others do not. Our experience is that when using intraoperative radiography we often change the osteotomy position to improve the correction of the hallux valgus angle and sesamoid position.

We report the results of a single surgeon series of 62 consecutive patients who underwent a scarf osteotomy for hallux valgus. The first 31 patients underwent surgery without the use of intraoperative radiographs and the subsequent 31 patients underwent surgery with the use of intraoperative radiographs, this reflects a change in the surgeons practice. Hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle and sesamoid position using the Hardy Clapham grading system were recorded. All patients had measurements recorded from weight baring radiographs taken pre operatively as well as at 6 and 12 weeks post operatively. Intraoperative measurements were also recorded for all patients in the intraoperative radiography group.

The mean hallux valgus angle preoperatively was 28.5° in the control group and 30.5° in the intraoperative radiography group. The mean hallux valgus angle in the control group at 6 weeks was 12.4° and at 12 weeks was 12.6°. The mean hallux valgus angle in the intraoperative radiography group at 6 weeks was 10.5° and at 12 weeks was 9.8°.

The median sesamoid position pre operatively was 4 for both groups. At 6 and 12 weeks the sesamoid position improved by a median of 1 position in the control group and 2 positions in the intraoperative radiography group (p<0.05).

We recommend that surgeons who do not routinely use intraoperative radiography undertake a trial of this. We have found that the use of intraoperative radiography improves the correction of hallux valgus angle and sesamoid position. These have been shown to increase patient satisfaction and reduce recurrence.

Introduction

Arthroplasty for treatment of end stage hallux rigidus is controversial. Arthrodesis remains the gold-standard, but this procedure is not without complications, with up to 10% non-union, 14% re-operation and 10% transfer metatarsalgia rates reported.

The aim of this study was to analyse the outcome of the double-stemmed silastic implant (Wright-Medical) for end stage hallux rigidus.

Background

Patient reported outcome and experience measures have been a fundamental part of the NHS. We used PROMS2.0, a semi-automated web-based system, which allows collection and analysis of outcome data, to assess the patient reported outcome/experience measures for scarf+/− akin osteotomy for hallux valgus.

Background. The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to classify the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction. Methods. We included 20 cavovarus feet from adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, 14 males). Patients included had flexible deformities, with no previous surgery. Previous work established majority of rotational deformity in cavovarus feet occurs at the talonavicular joint, which is often reduced during surgery. Using specialised software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using data from normal feet as a guide, the talonavicular joint of the cavovarus feet was digitally reduced to a ‘normal’ position. Models of the corrected position were exported and geometrically analysed using Blender 3.6 to identify anatomical trends. Results. We identified 3 types of cavovarus forefoot morphotypes. Type 1 was seen in 13 cases (65%) and was defined as a foot where only the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular correction. Type 2 was seen in 4 cases (20%) and was defined as a foot where the second and first metatarsals were progressively plantarflexed, with no significant adduction. Type 3 was seen in 3 cases (15%) and was defined as a foot where the metatarsals were still adducted after talonavicular de-rotation. Conclusion. We classify 3 forefoot morphotypes in cavovarus feet. It is important to recognise and anticipate the residual forefoot deformities after hindfoot correction as different treatment strategies may be required for different morphotypes to achieve balanced correction

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

Purpose. To explore the relationship in terms of time scale between pre-operative expectations and postoperative outcomes and satisfaction after Hallux valgus surgery. Methods. A patient derived questionnaire was developed and 30 patients aged 19 to 67 were included undergoing primary hallux valgus correction with a first metatarsal osteotomy and distal soft tissue release. Patients were asked pre-operatively to quantify their expected time scale for improvement in pain, ability to walk unaided, ability to drive, routine foot wear and foot feeling normal at 6 weeks, 3 and 6 months following surgery, and to indicate their confidence in achieving this result. Patients recorded postoperative outcomes achieved at number of weeks. Ordinal logistic regression multivariate modelling was used to examine predictors of postoperative satisfaction. Results. 90% of the patients were able to walk unaided and drive before or around the expected time scale at an average of five weeks' time. Persistent pain subsided at an average of two weeks post operatively which led to high satisfaction Although differences between patients' expectation and achievement were minimal at 6 weeks post-operatively, there was some discrepancy at 3 months, with patient expectations far exceeding achievement. The least satisfactory outcome was normal feeling of foot at six months follow up. There were significant correlations between failure to achieve expectations and the importance patients attached to recovery. Conclusions. This study underlines the importance of taking preoperative expectations into account to obtain an informed choice on the basis of the patient's preferences. Patients' pre-operative expectations of surgical outcome exceed their functional achievement but satisfaction remains high if pain control and ability to walk unaided is achieved early after hallux valgus corrective surgery

Background. Treatment of arthrogrypotic clubfoot (AC) presents a challenging problem. Over time many different methods have been proposed, with variable rates of success, recurrence and other complications. In this study we describe our 20-year experience in treatment of AC. Materials and methods. Between 1996 and 2016, 165 AC in 90 children (51 males and 39 females) were treated in our department. Their mean age was 7.6 years (3 months-16 years). Ponseti casting and Achilles tendon release (PCATR) was performed on 38 children (68 feet) and soft tissue release and casting (STRC) on 35 children (67 feet). The remaining 17 children (30 feet) underwent wide soft tissue release and correction using the Ilizarov method (STRIL). The results of each subgroup were graded according to clinical (pain, foot appearance, residual deformities, walking and standing status and shoe modifications) and radiological (anteroposterior and lateral talocalcanear angles, the angle between longitudinal axes of talus and the first metatarsal and the position of talus in the lateral view) criteria. Results. The average follow up was 6.4 (2–10) years. Results were excellent (plantigrade, painless, properly loaded feet, without deformities, adapted to common shoes) in 56 PCATR group feet, 59 STRC group feet and 23 STRIL group feet. Good results (required orthopaedic shoes) were obtained in 10 PCATR group feet, 6 STRC group feet and 7 STRIL group feet. Fair results (residual temporary pain and/or mild deformity) presented 2 PCATR group feet and 1 STRC group foot, while bad results (reoccurrence of clubfoot) were found in 1 STRC group foot. Conclusions. On the basis of our 20-year clinical experience we believe that pediatric AC can be successfully treated with PCATR in the age of less than 1 year old (y.o), with STRC between 1–5 y.o. and with STRIL in children over the age of 5 y.o

One of the complications of hallux valgus surgery is shortening of the first metatarsal and this becomes particularly symptomatic in patients with a pre existing short metatarsal (Morton's foot or Greek foot). Initial treatment consists of appropriate insoles which incorporate not only relief of pain due to pressure metatarsalgia under the lesser metatarsal heads but also a Morton type extension under the big toe. Insoles with metatarsal relief are, however, not always well tolerated and surgery becomes necessary. The options are to shorten the lesser metatarsal heads or lengthen the previously shortened first metatarsal. Arthrodesis of the great toe metatarso-phalangeal joint can provide functional length to the first metatarsal. We have achieved good results in lengthening of the first metatarsal and believe that it is a safe option which avoids trauma to the lesser metatarso-phalangeal joints. The technique is presented and depends on whether there is a residual hallux valgus or whether the toe is well aligned. The operation should address the plane of the deformity and reverse the cause of the lengthening. Emphasis should however be placed in not getting the complication in the first instance and the incidence of the problematic short first metatarsal has significantly reduced since the decrease in popularity of the Wilson osteotomy

Diagnostic and operative codes are routinely collected for every patient admitted to hospital in the English NHS. Data on post-operative complications following foot and ankle surgery have not previously been available in large numbers. Data on symptomatic venous thromboembolism events and mortality within 90 days were extracted for patients undergoing fixation of an ankle fracture, first metatarsal osteotomy, hindfoot fusions and total ankle replacement over a period of 42 months. For ankle fracture surgery (45 949 patients), the rates of deep-vein thrombosis (DVT), pulmonary embolism and mortality were 0.12%, 0.17% and 0.37%, respectively. For first metatarsal osteotomy (33 626 patients), DVT, pulmonary embolism and mortality rates were 0.01%, 0.02% and 0.04%, and for hindfoot fusions (7033 patients) the rates were 0.03%, 0.11% and 0.11%, respectively. The rate of pulmonary embolism in 1633 total ankle replacement patients was 0.06%, and there were no recorded DVTs and no deaths. Statistical analysis could only identify risk factors for venous thromboembolic events of increasing age and multiple comorbidities following fracture surgery. Venous thromboembolism following foot and ankle surgery is extremely rare, but this subset of fracture patients is at a higher risk. However, there is no evidence that thromboprophylaxis reduces this risk, and these national data suggest that prophylaxis is not required in most of these patients

Introduction. Metatarsus adductus (MA) increases the risk of recurrence following surgery for hallux valgus (HV). The goal of this study was to analyze patients with severe MA and identify clinical/surgical factors that are associated with a lower rate of recurrent deformity. Methods. 587 patients underwent correction of HV deformity. The rate of recurrence of HV was 15% (63 out of 414 patients) in patients without MA (MA angle < 20°) and 29.6% (50 out of 173 patients) in patients with MA. 19 patients with severe MA (>31°) were identified; 8 of 19 had associated tarsometatarsal arthritis, and two patients had a skew foot deformity. Ten patients had severe valgus lesser toe deformities. Clinical information collected included associated diagnoses, the presence of arthritis of the tarsometatarsal joints, the presence and degree of lesser toe valgus deformities and surgical procedures performed. Radiographic recurrence was defined as a postoperative HVA > 20°. Results. 9/19 patients were treated with a modified Lapidus procedure and 10 patients underwent a distal first metatarsal osteotomy. Of the 9 patients who were treated with a modified Lapidus procedure, 6 patients underwent simultaneous realignment lesser metatarsal osteotomy or arthrodesis of the 2. nd. /3. rd. TMT joints. 1/9 of these patients had radiographic recurrence of deformity. Of the 10 patients who underwent a distal first metatarsal osteotomy without realignment proximal osteotomy or arthrodesis, 5 had recurrence of deformity. Of the 11 patients with severe valgus lesser toe deformity, those who were treated with simultaneous additional distal lesser metatarsal osteotomies, did not have recurrence of hallux valgus. Conclusion. The use of a modified Lapidus procedure led to a lower rate of HV deformity recurrence in comparison to isolated distal first metatarsal osteotomies. Treatment of lesser toe deformity with distal osteotomy should be included as part of the treatment algorithm

Introduction. Hallux valgus surgical correction has a variable but significant risk of recurrence. Symptoms result from an iatrogenic first brachymetatarsia following the index surgical procedure. First metatarsal shortening has been shown to correlate with the onset of transfer metatarsalgia. We describe the use of the scarf osteotomy to both correct the recurrent deformity and lengthen the shortened first metatarsal. Methods. 36 lengthening scarf osteotomies were undertaken in 31 patients. Clinical (AOFAS and SF12 scores) and radiographic measures (IMA, HVA) were taken pre- and post-operatively. The maximum theoretical lengthening was 10mm, to prevent first MTP joint stiffness post-operatively. The actual lengthening was determined and measured intra-operatively. Results. There were 28 female and three male patients, with mean age at presentation 53.4 years. The mean follow-up was 3.9 years. Four cases were lost to follow-up. The mean first metatarsal lengthening achieved was 4.9mm (range 1–8mm). All of the osteotomies united without complication. The mean IMA reduction was 4.0° (p<0.001) and HVA 13.0° (p<0.001). The mean AOFAS score increase was 33.8 (p<0.001). There was no correlation between change in IMA and AOFAS score (r=−0.13) or between improvement in HVA and AOFAS score (r=−0.02). There was a positive trend but no correlation (r=0.28) between amount of metatarsal lengthening and change in AOFAS score. The inter- and intra-observer correlation was excellent. The SF12 physical sub-domains improved more than the mental sub-domains. Conclusion. We describe the largest series of lengthening scarf osteotomies for recurrent hallux valgus and symptomatic iatrogenic first brachymetatarsia. The significant improvement in both clinical and radiographical measures suggests the procedure is successful, with a low complication rate. Lengthening did not reduce the MTPJ range of movement. We hypothesise that restoring both the length and alignment enables greater weight-bearing under the first metatarsal head, reducing biomechanical transfer metatarsalgia

Introduction. The exact action of the Peroneus Longus muscle on the foot is not fully understood. It is involved in a number of pathological processes like tendonitis, tenosynovitis, chronic rupture and neurological conditions. It is described as having a consistent insertion to the base of the first metatarsal, but there have also been reports of significant variations and additional slips. Our aim was to further clarify the anatomy of the main insertion of the Peroneus Longus tendon and to describe the site and frequency of other variable insertion slips. Methods and Materials. The course of the distal peroneus longus tendon and its variable insertion was dissected in 12 embalmed, cadaveric specimens. The surface area of the main insertion footprint and angle of insertion was measured using an Immersion Digital Microscribe and 3D mapping software. The site and frequency of the other insertion slips is also presented. Results. There was a consistent, main insertion to the infero-lateral aspect of the first metatarsal in all specimens. The only additional slip was to the medial cuneiform. This did not increase the total footprint. Discussion. The main footprint of the Peroneus Longus tendon is on the first metatarsal. There was an additional slip to the medial cuneiform in 33% of our specimens. Although we are unsure about the significance of this additional slip, we hope it will lead to a better understanding of the mechanism of action of this muscle and its role both in the normal and pathological foot

Aims. The mainstay of surgical correction of hallux valgus is first metatarsal osteotomy, either proximally or distally. We present a technique of combining a distal chevron osteotomy with a proximal opening wedge osteotomy, for the correction of moderate to severe hallux valgus. Patients and Methods. We reviewed 45 patients (49 feet) who had undergone double osteotomy. Outcome was assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) and the Short Form (SF) -36 Health Survey scores. Radiological measurements were undertaken to assess the correction. The mean age of the patients was 60.8 years (44.2 to 75.3). The mean follow-up was 35.4 months (24 to 51). Results. The mean AOFAS score improved from 54.7 to 92.3 (p < 0.001) and the mean SF-36 score from 59 to 86 (p < 0.001). The mean hallux valgus and intermetatarsal angles were improved from 41.6. o. to 12.8. o. (p < 0.001) and from 22.1. o. to 7.1. o. , respectively (p < 0.001). The mean distal metatarsal articular angle improved from 23. o. to 9.7. o. The mean sesamoid position, as described by Hardy and Clapham, improved from 6.8 to 3.5. The mean length of the first metatarsal was unchanged. The overall rate of complications was 4.1% (two patients). Conclusion. These results suggest that a double osteotomy of the first metatarsal is a reliable, safe technique which, when compared with other metatarsal osteotomies, provides strong angular correction and excellent outcomes with a low rate of complications. Cite this article: Bone Joint J 2016;98-B:1202–7

The purpose of this study was to compare the results of proximal and distal chevron osteotomy in patients with moderate hallux valgus. We retrospectively reviewed 34 proximal chevron osteotomies without lateral release (PCO group) and 33 distal chevron osteotomies (DCO group) performed sequentially by a single surgeon. There were no differences between the groups with regard to age, length of follow-up, demographic or radiological parameters. The clinical results were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system and the radiological results were compared between the groups. At a mean follow-up of 14.6 months (14 to 32) there were no significant differences in the mean AOFAS scores between the DCO and PCO groups (93.9 (82 to 100) and 91.8 (77 to 100), respectively; p = 0.176). The mean hallux valgus angle, intermetatarsal angle and sesamoid position were the same in both groups. The metatarsal declination angle decreased significantly in the PCO group (p = 0.005) and the mean shortening of the first metatarsal was significantly greater in the DCO group (p < 0.001). We conclude that the clinical and radiological outcome after a DCO is comparable with that after a PCO; longer follow-up would be needed to assess the risk of avascular necrosis. Cite this article: Bone Joint J 2013;95-B:649–56

Introduction. The aetiology of hallux valgus is almost certainly multifactoral. The biomechanics of the first ray is a common factor to most. There is very little literature examining the anatomy of the proximal metatarsal articular surface and its relationship to hallux valgus deformity. Methods. We examined 42 feet from 23 specimens in this anatomical dissection study. Results. This analysis revealed three distinct articular subtypes. Type 1 had one single facet, type 2 had two distinct articular facets, and type 3 had three articular facets one of which was a lateral inferior facet elevated from the first. Type 1 joints occurred exclusively in the hallux valgus specimens, while type 3 joints occurred exclusively in normal specimens. Type 2 joints occurred in both hallux valgus and normal specimens. Another consistent finding in regards to the proximal articular surface of the first metatarsal was the lateral plantar prominence. This prominence possessed its own articular surface in type 3 joints and was significantly flatter in specimens with hallux valgus (p < 0.001) and the angle with the joint was significantly more obtuse (p < 0.001). Conclusions. We believe the size and acute angle of this prominence gives structural mechanical impedance to movement at the tarsometatarsal joint and thus improves the stability