Tarsometatarsal Research Articles

First Tarsometatarsal Alignment May Self-Correct After Triple Arthrodesis in Progressive Collapsing Foot Deformity.

Triple arthrodesis is commonly used to correct rigid progressive collapsing foot deformity (PCFD). These patients often have associated first tarsometatarsal (TMT) instability on lateral weightbearing radiographs. It has not been well established if it is necessary to add first TMT arthrodesis to adequately correct the overall deformity. This study retrospectively examined pre- and postoperative radiographs of PCFD patients with first TMT instability that were managed by triple arthrodesis alone. All triple arthrodesis cases were searched for a single surgeon between 2013 and 2021. Inclusion criteria were patients with PCFD who underwent triple arthrodesis without first TMT joint fusion. Preoperative radiographs were examined for first TMT joint instability, demonstrated by plantar gapping of the first metatarsal-medial cuneiform angle or first metatarsal dorsal subluxation at the TMT joint. Measurement of sagittal first metatarsal-medial cuneiform angle and first metatarsal subluxation as described by King and Toolan was performed. Twenty patients satisfied the inclusion criteria. Six patients did not demonstrate at least 30% improvement of one or both measurements of first TMT instability postoperatively and were considered failures. Fourteen patients demonstrated correction of their first TMT joint instability. Average follow-up was 5.0 (range, 1.8-9.4) years. The first metatarsal-medial cuneiform angle improved from 3.8 to 1.1 degrees (P < .05). The first metatarsal subluxation corrected from 4.1 to 1.5 mm (P < .05). One patient showed radiographic evidence of arthritis in the first TMT joint at final follow-up. Seventy percent of patients with PCFD with asymptomatic first TMT joint instability demonstrated correction of first TMT radiographic instability with isolated triple arthrodesis. This was maintained at 5-year mean follow-up. In cases of PCFD with medial column instability, triple arthrodesis alone may be adequate to restore overall alignment.

Total Ankle Arthroplasty as a Correction Tool for Foot Deformities: Analyzing the Impact on Medial Column Alignment Adaptation Through Weightbearing Computed Tomography.

While weightbearing computed tomography (WBCT) has been instrumental in analyzing total ankle arthroplasty (TAA) positioning, there is a notable gap in the literature regarding adaptive changes in the foot's medial column after TAA. This study aims to bridge this gap by comparing preoperative and postoperative alignments of the foot's medial column and analyzing if a correlation exists between TAA coronal alignment correction and medial column alignment adaptation. Sixty patients who underwent a lateral approach TAA for end-stage osteoarthritis (OA) between January 2021 and April 2023 were included in this retrospective study. Patients were divided into varus (n = 30) and valgus (n = 30) groups. Preoperative and postoperative WBCT scans were analyzed to measure medial column alignment. Statistical analysis evaluated alignment corrections and correlations. Both groups showed significant plantarflexion of the second tarsometatarsal (TMT) angle, with a median adaptation of -1 degree (IQR -3, 0; P < .01) in the valgus group and -1 degree (IQR -3, 0; P = .03) in the varus group. The varus group exhibited increased plantarflexion of the first TMT angle (median -1 degree, IQR -1, -2; P = .03). Both groups demonstrated increased adduction of the medial column. The talonavicular coverage angle adaptation averaged 7.2 ± 14 degrees (P < .01) in the valgus and 9 ± 12 degrees (P < .01) in the varus group. The talo-first metatarsal axial angle adaptation was 5 ± 13 degrees (P = .03) in the valgus group and 9.5 ± 15 degrees (P = .08) in the varus group. WBCT analysis revealed significant medial column adaptation post-TAA in varus and valgus alignments. However, no correlation was found between hindfoot correction and forefoot adaptation, making it challenging to predict the need for additional realignment surgeries. Future studies should explore the relationship between tibiotalar correction and medial column alignment to improve outcomes and the influence of total ankle design on medial column adaptation. Level III, retrospective case control study.

The vertical mobility of the first tarsometatarsal joint during demi-plié with forced turnout in ballet dancers

The forced turnout has a perceived risk of development of hallux valgus (HV) in ballet dancers. We determined how the forced turnout affects the sagittal mobility of the first tarsometatarsal (TMT) joint, which is one of the pathogenic factors of HV development. Seventeen female ballet dancers (body mass index: 18.2 ± 1.8 kg/m2) were included and performed demi-plié in control, functional turnout, and forced turnout conditions. Ultrasound imaging synchronized with a three-dimensional motion analysis system was used for measuring the vertical locations of the first metatarsal and medial cuneiform (MC) to evaluate the first TMT joint mobility. Plantar displacement of MC and the first TMT joint mobility in the forced turnout were the greatest among the 3 conditions. Multiple regression analysis indicated that the greater extent of the forcing angle might increase the displacement of MC and the first TMT joint mobility. Evaluating the sagittal mobility of the first TMT joint in the forced turnout can assist in understanding the association between inappropriate techniques including the forced turnout and HV development in ballet dancers. Since the excessive mobility of the first TMT joint is a factor in HV development, the acquirement of adequate active turnout may have the potential to prevent HV development in ballet dancers.

Radiological Heatmap of Tarsometatarsal Capsule Locations: A Cadaveric Study

Introduction/Purpose: Minimal invasive proximal metatarsal osteotomy (PMO) offers a successful approach for addressing metatarsus adductus while avoiding exposure of all metatarsals, thereby reducing the risk of complications such as wound infections and non-unions. An important hurdle is the absence of direct visualization for precise osteotomy placement. Staying within the tarsometatarsal (TMT) capsule enhances the chances of better union due to improved blood supply, although operating outside the capsule can aid in correcting more significant deformities. Despite having a macroscopic understanding of anatomical locations through specimens, there has been a lack of prior reports on their mapping in fluoroscopic images. Developing such maps could significantly improve the navigational skills of surgeons. This study aims to present heatmaps that illustrate the positions of distal attachments of TMT capsules. Methods: A total of nine specimens below the knee, devoid of any prior bone or joint abnormalities, were thawed a day prior to the experiments. After dissecting the dorsal skin, neurovascular structures, and tendons, only the bones and capsules remained. Flexible wires were placed alongside the distal edges of TMT capsules, encompassing the 1st, 2nd, 3rd, and 4th tarsometatarsal joints. This arrangement aimed to make the paths of these capsules visible when observed through X-ray imaging. The wires were then securely attached to the structures using a soft tissue adhesive. Fluoroscopy images were captured, including a calibration marker of a known diameter, in addition to taking macroscopic photographs. The specific coordinates of these structures were marked in a three-dimensional space within specialized 3D software. Subsequently, these coordinates were imported into a custom-designed Python script crafted for the purpose of generating heatmaps. Results: The heatmaps were successfully produced encompassing all TMT capsules spanning from the 1st to the 4th, and these were overlaid onto an anteroposterior fluoroscopy image of the foot (refer to Figure 1). This gradient of colors serves as a visual representation of differing magnitudes, with red denoting the most prevalent areas of the distal attachment of the TMT capsule, while blue corresponds to lower occurrences. Conclusion: These heatmaps not only showcase the predominantly observed sites of distal TMT attachments, depicted in red, but also signify diverse deviations, identifiable by the presence of less frequent zones indicated in blue. Consequently, surgeons are advised to consider these findings while planning their osteotomies based on their preferred positions. By furnishing surgeons with an extensive heatmap that outlines potential tarsometatarsal capsule insertions, this research not only furnishes them with a dependable guiding resource but also establishes a foundation for more assured and prosperous minimally invasive midfoot fusion procedures. Figure 1: The heatmap of 1st to 4th tarsometatarsal capsules on AP fluoroscopy.

Surgical planning for staple fixation of the first tarsometatarsal joint: An anatomic study

First tarsometatarsal (TMT) arthrodesis is a common procedure utilized by foot and ankle surgeons for the management of a variety of first TMT pathology including hallux valgus and arthritis. The present study was undertaken to determine the average staple leg depth that allows for adequate purchase within the medial cuneiform and first metatarsal base at 2 different staple bridge lengths for dorsal compression across the 1st TMT joint. A cadaveric study was performed using 20 fresh-frozen below knee specimens. After TMT dissection was performed, drill holes were then created from dorsal to plantar and parallel to the first TMT joint at the distances utilized for 20 mm and 25 mm staple bridge lengths. The depths of each drill hole were measured and recorded. The mean medial cuneiform depth corresponding to a 20 mm and 25 mm staple bridge was 31.9 mm +/- 2.8 mm and 31.1 mm +/- 2.1 mm respectively (P-value = 0.38). The mean first metatarsal depth corresponding to a 20 mm and 25 mm staple bridge was 27.9 mm +/- 2.2 mm and 25.4 mm +/- 3.4 mm respectively (P-value = 0.04), showing statistical significance. Based on our anatomic data it is suggested that a 20 mm staple leg depth is consistently a safe depth when using 20×20 and 25×20 mm dorsal compression staples. However, further studies must be conducted to compare the amount of compression between the two respective staples.

1st to 2nd metatarsal base cross-screw in the modified Lapidus proc

First tarsometatarsal (TMT) arthrodesis or the modified Lapidus (ML) is a common procedure utilized by foot and ankle surgeons for the management large bunion deformities, particularly in the presence of medial column instability. The purpose of the present anatomic study was to assist surgeons in preoperative planning for ML procedure utilizing the first metatarsal to second metatarsal cross-screw technique by assessing the average length of screw guidewire placed bi-cortically through the first metatarsal and second metatarsal at a location specific to the ML procedure with metatarsal to second metatarsal cross-screw technique. This was a cadaveric study utilizing 20 fresh-frozen below-the-knee specimens. After dissection, joint preparation, and stabilization, a cannulated 4.0 screw was then placed across the first and second metatarsal bases from medial to lateral starting 1 cm distal to the 1st TMT joint. Once appropriate length and orientation was achieved the guidewire was measured using a cannulated depth gage and values were then recorded on a spreadsheet and analyzed. Amongst the 20 specimens the mean guidewire length was found to be 34 mm +/- 3.2 mm. The median guidewire length was found to be 34 mm (range: 29 – 41 mm). The present anatomic study defined the mean and median lengths of a first metatarsal to second metatarsal screw utilized for medial column stabilization and spot weld arthrodesis in the ML procedure.

Effects of plantar fascia stiffness on the internal mechanics of idiopathic pes cavus by finite element analysis: implications for metatarsalgia

Metatarsalgia occurring in individuals with pes cavus is typically associated with abnormal loading patterns in the forefoot resulting from structural alterations. Simultaneously, the frequent overstress of the plantar fascia (PF) caused by the persistence of this foot deformity may further exacerbate the chronic pain induced by metatarsal overload. We aimed to investigate and quantify the effects of PF stiffness on the internal biomechanics of pes cavus using a computational modelling approach. A patient-specific finite element model of the foot-ankle complex using the actual three-dimensional geometry of idiopathic pes cavus bones and soft tissues was reconstructed. A sensitivity study was conducted to evaluate the effects of varying elastic modulus (0–700 MPa) of the PF on the metatarsal stress distribution, and force transmission through the metatarsophalangeal (MTP) and tarsometatarsal (TMT) joints in the pes cavus. The results indicated that variations in PF stiffness led to stress redistribution in the metatarsal region. Peak stress gradually reduced with decreasing stiffness until the PF was released, eventually resulting in a reduction of 22.39% compared to the reference value of 350 MPa. Furthermore, adjusting the PF stiffness to twice the reference value (700 MPa) increased the contact forces through the TMT and MTP joints by up to 23% and 116%, respectively. The reduction of PF stiffness alleviated focal metatarsal loading, and therefore, surgical fascia release can be considered to alleviate metatarsalgia in patients with pes cavus.

Adjacent Joint Arthritis Incidence Rate Following Fusion of the First Tarsometatarsal Joint as Treatment for a Forefoot Deformity

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: Nontraumatic forefoot deformities such as hallux valgus (HV) are common causes for patients seeking reconstructive surgery. Known as a “bunion,” HV is characterized by 1-2 intermetatarsal angle widening and first metatarsal head medial drift, resulting in the great toe pointing laterally. Surgery is indicated for patients who fail to find relief with conservative management. However, there is no consensus among orthopedic surgeons on whether osteotomy or first tarsometatarsal (TMT) arthrodesis is the better surgical treatment method. Additionally, no known studies have explored the development of adjacent joint arthritis in patients who have received a first TMT fusion. This study aims to investigate the rate of arthritis development in the adjacent joints following arthrodesis of the first TMT joint. Methods: A retrospective chart review at a tertiary foot and ankle clinic was performed on subjects who received a first TMT fusion between January 2004 and December 2017. This included subjects who received concomitant gastrocnemius recession, tendo-achilles lengthening, 1-2 intermetatarsal arthrodesis, 1-2 intercuneiform arthrodesis, hammertoe corrections, and other soft tissue releases deemed by the senior authors to be inconsequential in the case of adjacent joint arthritis development. Pre- operative, operative, and post-operative indications will be evaluated throughout this thorough chart review, and charts will be continually reviewed for inclusion and exclusion criteria. Patient information gathered includes age, sex, height, weight, BMI, activity level, smoking history, medications, time spent with hardware retained, the method of arthritis diagnosis (x-ray alone, CT, MRI, bone scan), relevant additional diagnoses, and operative data. Pre- and post-operative pain levels and satisfaction scores will follow the AOFAS Score Criteria. Results: Preliminary Results: 899 subjects (148 males, 751 females) are included in this study. The age range was 67 years (18 - 85), with an average age of 56.6 at surgery. Patient BMI varied from 12.7 to 53.1. Concurrent operative soft tissue procedures: gastrocnemius recession (749), tendo-Achilles lengthening (13), and a combination of the two (1). Concomitant fusions: isolated 1- 2 intermetatarsal arthrodesis (799) and combined with 1-2 intercuneiform arthrodesis (695). Clinical follow-up ranged from three to 186 months, averaging 34 (2 years, ten months). Presently, radiographic assessment has been performed for 154 of the 899 patients included in this study. Of these, 11 had developed adjacent joint arthritis at last radiographic follow-up (7.1%); two with naviculocuneiform arthritis, eight with talonavicular arthritis, and one with both. Conclusion: Based on preliminary data, a successful fusion of the first TMT joint, as treatment of a forefoot deformity such as HV, does not appear to accelerate the development of arthritis in the adjacent joints.

First Ray Mobility in Hallux Rigidus, Hallux Valgus, and Normal Feet Based on Weightbearing Computed Tomography and Three-Dimensional Analysis

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: Both hallux rigidus (HR) and hallux valgus (HV) are conditions that occur in the first ray. Although both are believed to originate from hypermobility of the first ray, they each ultimately result in different clinical feature. Hypermobility of the first ray is strongly involved in the pathogenesis of HV. In contrast, several studies have reported an association between HR and hypermobility of the first ray but few have actually analyzed the nature of that association. We hypothesized that in HR, there would be little rotational movement despite the presence of hypermobility of the first ray. The purpose of this study was to evaluate the first ray mobility in feet with HR, HV, and in healthy feet by using weightbearing and non-weightbearing CT and 3D analysis. Methods: In this case-control study, we examined 17 feet of 11 healthy volunteers with no history of foot disorders and no symptoms such as pain in the foot (control group), 16 feet of 16 patients with HV and 16 feet of 11 patients with HR. First, non- weightbearing foot CT imaging was performed with the participant supine on our original loading device, with the legs extended and the ankle in a neutral position, and then weightbearing CT imaging was performed by applying a load equivalent to body weight. Using an iterative closest point algorithm, each joint in the first ray—the talonavicular joint, the medial cuneonavicular joint, and the first tarsometatarsal (TMT) joint—was aligned using its respective proximal bone. Displacement of the distal bone relative to the proximal bone was quantified in 3D under both weightbearing and non-weightbearing conditions. Results: In the talonavicular joint, the HV group showed significantly greater eversion (p = 0.011) than the control group, and greater dorsiflexion (p = 0.027) and eversion (p &lt; 0.01) than the HR group. In the medial cuneiform joint, the HV group showed significantly greater eversion (p &lt; 0.01) and abduction (p = 0.011) than the control group. In the first TMTl joint, the HV group showed significantly greater dorsiflexion (p = 0.014), inversion (p = 0.028), and adduction (p &lt; 0.01) than the control group, and greater inversion (p &lt; 0.01) and adduction (p &lt; 0.01) than the HR group. The HR group showed significantly greater dorsiflexion (p = 0.026) than the control group. Conclusion: In the present study, hypermobility was observed at the first TMT in both HV and HR. However, the changes in HR were mainly in the sagittal plane, whereas those in HV were in all three planes. This difference may explain the different clinical feature ultimately observed in each condition. Future studies involving comparison of various severity levels and postoperative analysis should elucidate the pathophysiology and contribute to selection of appropriate treatment as well as the development of new treatments for HV and HR.

Development and functional validation of tarsometatarsal prosthesis

Assistive Technology (AT) plays a crucial role in providing aid products, including prostheses to persons with disabilities. Tarsometatarsal (TMT) disarticulation, a type of partial foot amputation, is associated with complex gait disorders. However, there is limited research on the functional impact of TMT prostheses on gait. This study aims to develop and functionally validate a 3D-printed TMT prosthesis using finite element analysis and human motion laboratory studies. A 65-year-old patient with TMT amputation participated. Digital models of the amputated and healthy feet were obtained through 3D scanning. The prosthesis design was created using Fusion 360 software. Finite element analysis validated the prosthesis design. The prosthesis was manufactured using thermofusion printing with a biocompatible thermoplastic elastomer material. Functional validation included walking, running, and the Timed Up and Go test using motion analysis technologies. Finite element analysis demonstrated the structural integrity and safety of the TMT prosthesis during propulsion. The manufacturing process resulted in an adjustable and cost-effective prosthesis. Functional validation revealed improvements in gait quality, symmetry, and spatiotemporal parameters with the prosthesis. Vertical ground reaction forces during walking resembled the normal range, and running performance showed increased symmetry and propulsion velocity. The Timed Up and Go test showed that prostheses reduce time and improve efficiency. The development and functional validation of the 3D-printed TMT prosthesis offer a promising solution for individuals with TMT disarticulation. This approach addresses the need for assistive technologies in low-income countries with limited access to prostheses. Advanced technologies and a patient-centred approach contribute to improving mobility, gait patterns, and overall quality of life for individuals with partial foot amputations. Future research will focus on exploring additional parameters and developing new prostheses to further enhance gait improvements.

Simulated Weightbearing and Articular Injury From Transarticular Screws in a Ligamentous Lisfranc Injury Model.

Transarticular screw fixation is a common surgical treatment for tarsometatarsal ligamentous (Lisfranc) injuries. Iatrogenic damage to articular cartilage from screw placement, however, has been thought to potentially lead to increased risk of tarsometatarsal (TMT) joint arthritis after initial injury. To date, no study has evaluated the effect of weightbearing on articular cartilage after screw fixation. The aim of this study was to create a Lisfranc injury and quantify and compare articular damage due to screw fixation before and after simulated weightbearing. A ligamentous Lisfranc injury was created in 10 cadaveric specimens and treated with transarticular screws. Specimens were cycled for 1000 cycles at 250 N to simulate 2 weeks of physiologic weightbearing. Rotation and diastasis across the Lisfranc complex were measured. Articular injury as a percentage of total articular surface was measured using digital imaging of the first and second TMT joint before and after simulated weightbearing. Comparisons between articular damage were made and statistical analysis was performed. Simulated partial weightbearing increased articular injury 1.44-fold (P < .001). The second metatarsal (M2) showed the greatest increase (1.54-fold, P = .0047), whereas the first (M1) showed the least (1.35-fold, P = .0083). Increases seen at the medial (1.43-fold, P = .0387) and middle cuneiform (1.44-fold, P = .0292) were intermediate between the values seen at M2 and M1. Articular damage from transarticular screw fixation significantly increased after simulated partial weightbearing. This may increase the risk of arthritis and future morbidity when using transarticular screws for the treatment of ligamentous Lisfranc injuries. Iatrogenic damage to articular cartilage due to screw fixation of ligamentous Lisfranc injuries may be increased with weightbearing.

Biomechanical Evaluation of Fourth Generation Minimally Invasive Distal First Metatarsal Osteotomy-Akin Osteotomy Technique on First Ray Articular Contact Properties.

Hallux valgus is a common deformity encountered but remains a complex clinical entity. Fourth-generation minimally invasive surgery (MIS) techniques consisting of a percutaneous distal metatarsal transverse osteotomy combined with an Akin osteotomy have been used to address mild to severe hallux valgus deformities. The benefits of an MIS approach include improved cosmesis, faster recovery, lower opiate requirement, immediate weightbearing, and favorable outcomes relative to a traditional, open procedure. An understudied area with respect to hallux valgus correction is the effect that osteotomies can have on the articular contact properties of the first ray following correction. Sixteen paired cadaveric specimens were dissected to include the first ray and tested in a customized apparatus. Specimens were randomized to receive a distal transverse osteotomy translated either 50% or 100% of the width of the first metatarsal shaft. The osteotomy was performed with either a 0° or 20° distal angulation of the burr relative to the shaft in the axial plane. Specimens were tested in the intact state and following the distal first metatarsal osteotomy for peak pressure, contact area, contact force and center of pressure at the first metatarsophalangeal (MTP) and first tarsometatarsal (TMT) joints. An Akin osteotomy was then performed on each specimen, and peak pressure, contact area, contact force, and center of pressure were recalculated. There was a notable decrease in peak pressure, contact area, and contact force across the TMT joint with greater shifts of the capital fragment. However, at 100% translation of the capital fragment, distal angulation of the osteotomy by 20° appears to improve loading across the TMT joint. Addition of the Akin osteotomy at 100% translation also aids in increasing the contact force across the TMT joint. The MTP joint is less sensitive to changes in shifts and angulation of the capital fragment. The Akin osteotomy also leads to increased contact force across the MTP joint when the capital fragment is translated 100%. While the clinical significance is unknown, larger shifts of the capital fragment lead to greater load alterations at the level of the TMT joint than the MTP joint. Distal angulation of the capital fragment and the addition of an Akin osteotomy can aid in reducing the size of those changes. The Akin can lead to increased contact forces at the MTP joint with 100% translation of the capital fragment. Not applicable, Biomechanical study.

Differential contribution of lateral plantar foot ligaments to lateral column stability – A cadaver based sectioning analysis

Lateral column (LC) instability occurs in adult acquired flatfoot deformity (AAFD). Differential ligament contribution to LC stability is unknown. The primary aim was to quantify this by using cadaver sectioning of lateral plantar ligaments. We also determined the relative contribution of each ligament to dorsal translation of the metatarsal head in the sagittal plane.17 below-knee cadaveric specimens, preserved by vascular embalming method, were dissected to expose plantar fascia, long/short plantar ligaments (L/SPL), calcaneocuboid (CC) capsule and inferior 4th/5th tarsometatarsal (TMT) capsule. Dorsal forces of 0 N, 20 N and 40 N were applied to the plantar 5th metatarsal head after sequential ligament sectioning in different orders. Pins provided linear axes on each bone, allowing relative angular bone displacements to be calculated. Photography and ImageJ processing software were then used for analysis.The LPL (and CC capsule) had the greatest contribution to metatarsal head motion (107 mm) after isolated sectioning. In the absence of other ligaments, sectioning these resulted in significantly increased hindfoot-forefoot angulation (p ≤ 0.0003). Isolated TMT capsule sectioning demonstrated significant angular displacement even when other ligaments remained intact (with intact L/SPL, p = 0.0005). CC joint instability required both LPL and capsular sectioning for significant angulation to occur, whilst TMT joint stability was largely dependent on its capsule.The relative contribution of static restraints to the lateral arch has not yet been quantified. This study provides useful information on relative ligament contribution to both CC and TMT joint stability, which may in turn improve understanding of surgical interventions used to restore arch stability.

Maintenance of Correction of the Modified Lapidus Procedure With a First Metatarsal to Second Metatarsal Screw With “Spot Weld” Technique: A Retrospective and Radiographic Analysis

Lapidus first tarsometatarsal (TMT) arthrodesis gained popularity for its ability to correct large deformities especially in cases of medial column instability. Despite solid first TMT fusion, instability between the first and second columns can result in loss of intermetatarsal (IM) angle correction over time. A "spot weld" or fusion between the first and second metatarsal may improve maintenance of correction. This retrospective study reviewed cases of Lapidus arthrodesis with first to second metatarsal base screw fixation for maintenance of IM correction and determine whether a "spot weld" is predictive of maintenance. A total of 90 cases (77 patients) performed by a single surgeon met inclusion with average follow-up of 309 days. First TMT fusion occurred in 87/90 (96.7%) cases with 76 dorsal plate, 10 dorsal staple, and 4 all screws. No incidence of complications related to the 1-2 screw was noted. Mean preoperative IM 1-2 angle 14.90°, mean correction to 6.22° post-operative and final maintained correction at 7.10°, mean loss of correction 0.87°. There were "spot welds" in 65/90 (72.2%) with mean loss of 0.48° versus loss of 1.88° in "no spot weld" subgroup (p < .001). Cases with no spot weld and screw lucency lost 2.25° (p < .001). Loss of IM 1-2 correction can occur due to first and second ray intra-column instability even in cases of solid first TMT arthrodesis. Incorporating a completed "spot weld" with bone grafting and first to second metatarsal screw was found to maintain correction with minimal loss (0.87°).

Investigation on the site of coronal deformities in Hallux valgus

Hallux valgus (HV) is a common foot deformity that is more prevalent in females, characterised by abnormal adduction of the first metatarsal (MT) and valgus deviation of the phalanx on the transverse plane. Increasing evidence indicates that HV is more than a 2D deformity but a 3D one with rotational malalignment. Pronation deformity is seen during clinical examination for HV patients, but the exact origin of this rotational deformity is still unknown. Some attribute it to first tarsometatarsal (TMT) joint rotation, while others attribute it to intra-metatarsal bony torsion. In addition, the correlation between the rotational and transverse plane deformity is inconclusive. Identifying the origin of the rotational deformity will help surgeons choose the optimal surgical procedure while also enhancing our understanding of the pathophysiology of HV. This study aims to (1) develop an objective method for measuring the first MT torsion and first TMT joint rotation; (2) investigate the exact location of the coronal deformity in HV; (3) investigate the relationship between the severity of deformity on the transverse and coronal planes as well as the correlation between deformity severity and foot function/symptoms in HV. Age-matched females with and without HV were recruited at the Foot and Ankle Clinic of the Department of Orthopaedics and Traumatology. Computed tomography was conducted for all subjects with additional weight-bearing dorsal-plantar X-ray examination for HV subjects. Demographic information of all subjects was recorded, with symptoms and functions related to HV evaluated. The intra-class correlation was used to explore the relationship between deformities on different planes and the deformity severity and functional outcomes, respectively. An Independent t-test was used to compare joint rotation and bone torsion degrees. TMT joint rotation is significantly correlated with foot function. HV patients had more TMT joint rotation but not MT torsion compared to normal controls. No relationship was found between the coronal rotation and the 1,2-intermetatarsal angle (IMA) or Hallux valgus angle (HVA) on the transverse plane. Our results indicate that coronal deformities in HV may originate from TMT joint rotation. In addition, the severity of the TMT joint coronal rotation correlates with worse foot function; thus, multi-plane assessment and examination will be necessary for more precise surgical correction.

Analysis of segmental coordination in the lower extremity using vector coding: a pilot return-to-play study of acute ankle sprain.

Purpose: Acute ankle sprain may affect ankle function during sport and daily activities. This study aimed to use vector coding technique to analyze the difference over time between injured and healthy lower limb during the first week of acute ankle sprain phase (P1) and post a 1-month recovery phase (P2) to understand the return-to-play coordination strategy in the lower extremity. Methods: Six females attended the gait experiments with attached 40 reflective markers using eight-camera Vicon motion capture system. All participants walked barefoot while turning in four directions (T0°, T45°, T90°, T135°) at their self-selected speed. Coordination patterns were classified as in-phase, anti-phase, proximal or distal dominancy between lower limb joints involving hip, knee, ankle, subtalar, metatarsophalangeal (MTP) joint and tarsometatarsal (TMT) joint. Results: P1 showed more proximal joint dominant in Hip-Knee coupling angles but P2 displayed more distal joint dominant in Knee-Ankle joint coordination pattern and mainly distal joint dominant in Ankle-MTP coupling angle mapping. The Ankle-TMT1 and Ankle-TMT5 coordination patterns matched best in straight walking but worst in T135 walking. Conclusions: Investigating inter-segmental coordination in different turning movements could provide insights into gait changes from acute ankle sprain from one-month return-to-play recovery. Knowledge of lower limb coordination pattern may provide clinical implications to improve dynamic balance and gait stability for individuals with acute ankle sprain.

Does temporary bridge plate fixation preserve joint motion after an unstable Lisfranc injury?

BackgroundRecently, temporary bridge plate fixation has gained popularity in the treatment of unstable Lisfranc injuries. The technique aims to reduce the risk of posttraumatic osteoarthritis, and after plate removal, the goal is to regain joint mobility. Here we explore marker-based radiostereometric analysis (RSA) to measure motion in the 1st tarsometatarsal (TMT) joint and asses the radiological outcome in patients treated with this surgical technique. MethodTen patients with an unstable Lisfranc injury were included. All were treated with a dorsal bridge plate over the 1st TMT joint and primary arthrodesis of the 2nd and 3rd TMT joints. The plate was removed four months postoperatively. Non- and weight-bearing RSA images were obtained one and five years postinjury to assess joint mobility and signs of osteoarthritis. ResultsDetectable 1st TMT joint motion was observed in 2/10 patients after one year, and 6/9 patients after five years. At the final follow-up, mean 1st TMT dorsiflexion was 2.0°. Radiologically, the incidence of posttraumatic osteoarthritis was present in 4/10 patients after one year, and 5/9 patients after five years. All patients had observed TMT joint stability throughout the follow-up period. ConclusionPreservation of joint motion can be achieved with a temporary bridge plate fixation over the 1st TMT joint. Type of study/level of evidenceProspective cohort study/Therapeutically level IV.

Kinematic Analysis of Sequential Partial-Midfoot Arthrodesis in Simulated Gait Cadaver Model.

Primary tarsometatarsal (TMT) arthrodesis is gaining popularity in the surgical treatment of Lisfranc injuries. However, few studies have evaluated biomechanical effects of TMT arthrodesis. The purpose of this study was to compare the kinematics of joints adjacent to the midfoot during simulations of stance before and after sequential arthrodesis of the first, second, and third TMT joints. Ten midtibia cadaveric specimens were loaded on a 6-degree-of-freedom robotic gait simulator. Motion capture cameras were used to collect joint kinematics throughout simulations of the stance phase. Simulations were performed for the intact and sequential arthrodesis conditions of the first, second, and third TMT joints. The sagittal, coronal, and transverse plane rotational kinematics of the intact condition were compared to kinematics after each sequential arthrodesis condition. Sequential arthrodesis of the first and second TMT joints had no significant effect on ankle, subtalar, talonavicular, and first metatarsophalangeal joint motion during simulated stance when compared to the intact condition. In contrast, inclusion of the third TMT joint into the sequential arthrodesis significantly increased subtalar inversion (P = .032) in late stance and increased range of motion values in the ankle and subtalar joints by 2.1 degrees (P = .009) and 2.8 degrees (P = .014), respectively. Sequential primary arthrodesis induced changes to ankle and adjacent joint kinematics during stance phase simulations, although not until the third TMT joint was included into the primary arthrodesis. The significant changes to kinematics due to arthrodesis of the first, second, and third TMT joints were small. The minimal changes in sagittal, coronal, and transverse plane rotational kinematics support the positive clinical outcomes reported in the literature for primary partial arthrodesis of Lisfranc injuries. The inclusion of the third TMT joint should be done judiciously.

Tarsometatarsal Joint Preparation using a Modified Dorsal Approach vs Standard Approach: A Cadaver Study

Category: Midfoot/Forefoot Introduction/Purpose: Lisfranc injuries are a relatively common midfoot injury involving the tarsometatarsal (TMT) joint. Surgical fixation typically involves open reduction with internal fixation or primary arthrodesis of the joint(s). The standard surgical approach to the TMT joint involves two dorsal incisions however, a recent study has suggested the use of a modified single dorsal incision approach. The goal of this paper is to compare the total surface area of the joint that can be prepared for primary arthrodesis of the TMT using the standard vs modified single dorsal approach. Methods: Ten fresh frozen below-the-knee cadaver specimens were randomly assigned to receive either the standard or modified dorsal single incision operative approach to the TMT joint. Prior to initiating the study, specimens were inspected with fluoroscopic radiographs for preexisting pathology or prior surgical intervention. The joint surface was visualized and then underwent articular preparation as for a joint fusion. After adequate joint preparation, the TMT joint was disarticulated and the surface was photographed for image analysis. Using ImageJ, articular joint surface preparation areas were measured by two blinded reviewers. to assess the joint surface preparation and this was compared by surgical approach. Results: After ImageJ and Mann-Whitney U statistical analysis, there was no significant difference in the amount of joint prepared when comparing the standard versus modified dorsal approach for the first three TMT joints (p= 0.548, p=0.310, p= 0.548). The percentage of joint preparation utilizing the standard dorsal approach versus the modified dorsal approach for TMT joints one through three are as follows (percentages utilized are listed as the median value with its correlating range): First TMT- 67.6% (range 26%) by the standard approach versus 71.7% (range 9%) by the modified dorsal approach, second TMT- 67.9% (range 24%) versus 65.7% (range 12%), and third TMT- 65.9% (range 42%) versus 59.6% (range 24%). Table 1 summarizes our results between each operative approach. Conclusion: With our findings, we demonstrate that a modified single dorsal approach to the Lisfranc joint provided comparable joint preparation for primary arthrodesis as the standard dual incision approach. However, the modified dorsal approach may be beneficial in that it avoids creating a skin bridge which has potential for necrosis with the standard two incision approach. The authors believe the comparable joint preparation combined with its potential to alleviate soft tissue complications make the modified dorsal approach a viable surgical approach for a TMT arthrodesis.

Functional Outcomes of Primary Arthrodesis vs Open Reduction and Internal Fixation in the Treatment of Lisfranc Injuries

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: The lack of data regarding functional outcomes of midfoot primary arthrodesis (PA) and open reduction and internal fixation (ORIF) contributes to significant debate regarding the optimal method of treatment for Lisfranc injuries. Although PA is associated with lower rates of secondary procedure and posttraumatic arthritis, its impact on foot functionality has come into question due to sacrifice of tarsometatarsal (TMT) mobility. The authors hypothesize that there is no significant difference between patient recorded outcome measures (PROMs) among patients receiving PA and ORIF for the treatment of Lisfranc injuries. Methods: A retrospective cohort study of patients surgically treated for Lisfranc injuries between January 2010 and January 2019 at a Level I trauma center was undertaken. Retrospective chart review was utilized to obtain patient demographics, comorbidities, procedural information, complications, and additional treatments. Responding by survey, patients reported their functional competency in performing daily and sports-related activities via the validated Foot and Ankle Ability Measure (FAAM) instrument. For each patient, scores for the Activities of Daily Living (ADL) and Sports sections were calculated. Patients also reported their perceived current level of function on a percent scale with respect to functionality prior to TMT injury. Results: Twenty-four patients underwent PA, and 27 patients underwent ORIF. There were no significant differences between age (P=0.55), incidence of high energy injury mechanisms (P=0.14), comorbidities, or time to surgical intervention from injury (P=0.25) among PA and ORIF groups. There were no significant differences in FAAM scores among PA and ORIF groups. The average ADL scores for PA (72.42 +- 17.53) and ORIF (68.11 +- 28.24) were not significantly different (P=0.52), nor were the average Sports scores for PA (47.92 +- 25.48) and ORIF (48.56 +- 29.44) groups (P=0.94). However, patients in the PA group reported a significantly higher level of perceived ADL function (77.96% +- 17.97%) compared to patients in the ORIF group (60.04% +- 35.47%, P=0.03); this was not the case for perceived Sports functionality (P=0.67). Conclusion: This analysis of PROMs revealed no significant difference in the ability to participate in ADLs and sports between PA and ORIF groups. These results align with our hypothesis and suggest that despite sacrificing TMT joint mobility, functional outcomes of patients receiving PA were not significantly different from those receiving ORIF for Lisfranc injuries.