Tarsometatarsal Arthrodesis Research Articles

Biomechanical analysis of a magnesium plantar plate prototype system for the first tarsometatarsal joint fusion: a cadaveric study

BackgroundTitanium plantar plates have proven successful in the fixation of the first tarsometatarsal arthrodesis (TMT). However, a second surgery is typically needed for implant removal, and potential adverse effects, carried by the conventional implantations, are not uncommon. The purpose of this study was to determine whether a novel magnesium-based plantar plate system provides similar fusion stability to a titanium-based plantar plate system under various loading conditions.MethodsSix matched-pair human cadaveric specimens underwent TMT fusions using either a magnesium plantar plate system prototype or a titanium plantar plate system. Specimens were cyclically loaded with a force ranging from 5 N to 50 N for 5,000 cycles, and displacement was recorded. Axial stiffness (N/mm) was calculated from load-displacement curves. Each specimen was loaded to failure at a rate of 5 mm/min, and the ultimate load was recorded.ResultsNo significant difference was found in the vertical displacement between Ti group and Mg group after 100 cycles (2.4 ± 1.0 mm vs. 1.3 ± 1.4 mm, p = 0.196), 500 cycles (3.3 ± 1.3 mm vs. 1.7 ± 1.7 mm, p = 0.142), 1,000 cycles (3.7 ± 1.5 mm vs. 1.9 ± 1.9 mm, p = 0.128), 2,500 cycles (4.2 ± 1.7 mm vs. 2.3 ± 2.2 mm, p = 0.172) and 5,000 cycles (4.5 ± 1.8 mm vs. 2.3 ± 3.3 mm, p = 0.125), Additionally, no significant differences were observed in initial stiffness (53.1 ± 19.2 N/mm vs. 82.2 ± 53.9 N/mm, p = 0.257), final stiffness (90.6 ± 48.9 N/mm vs. 120.0 ± 48.3 N/mm, p = 0.319), or maximum load-to-failure (259.8 ± 98.2 N vs. 323.9 ± 134.9 N, p = 0.369).ConclusionsBased on the performed biomechanical testing, the magnesium plantar plate system provides mechanical stability equivalent to the titanium plantar plate system in fixation for the first TMT joint fusion.

Biomechanical Performance of 4-Leg Sustained Dynamic Compression Staples in First Tarsometatarsal Arthrodesis.

This study investigates the biomechanical efficacy of new 4-leg Sustained Dynamic Compression (SDC) NiTiNOL staples, hypothesized to offer superior stability and resilience to loading before fusion completion, compared with conventional hardware. Twenty sawbones left full foot models were divided into 4 treatment groups: (1) 4-leg Inline Staple, (2) 4-leg Inline Staple + 2-leg Staple, (3) 4-leg Inline Staple + Screw, and (4) Plate + Screw. An osteotomy was performed to simulate a Lapidus procedure, and the respective fixation methods were applied. Mechanical testing was conducted using a servo-hydraulic testing machine to evaluate constructs' load, contact force, contact area, and plantar gap. The 4-leg Inline Staple + Screw group demonstrated significantly increased joint contact force, joint contact area, and decreased plantar gap compared with the Plate + Screw group, both before and after cyclic testing. All SDC-containing constructs exhibited post-cyclic joint contact areas that were 2.36×, 3.87×, and 5.49× greater than the post-cyclic plate + screw group. Most notably, the 4-leg Inline Staple + Screw group maintained a plantar gap of less than 3 mm throughout the testing, unlike other groups. The 4-leg Inline SDC Staple, particularly when combined with a static screw, demonstrated biomechanical superiority over traditional plate and screw constructs in Lapidus procedures. These findings suggest a promising avenue for enhanced post-operative stability, which could translate into quicker patient recovery, improved fusion rates, and potentially lower non-union rates. Further clinical trials are warranted to validate these biomechanical advantages in patient outcomes. Therapeutic, Level V: Bench Testing.

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.

Arthroscopy-assisted Minimally Invasive Tarsometatarsal and Lisfranc Arthrodesis. A Case Series.

First tarsometatarsal arthrodesis is an effective procedure for the correction of hallux valgus deformities. Traditionally, first to third tarsometatarsal and Lisfranc arthrodesis is performed via an open approach. Little is known about the role of combined arthroscopic and minimally invasive techniques. We present a case series of complicated hallux valgus deformities and other conditions managed using arthroscopically assisted minimally invasive arthrodesis. We first performed a minimally invasive surgical procedure that allowed easy and unhindered access for the introduction of an arthroscopic instrument over the joint surface. The mean Visual Analogue Score - Foot and Ankle and Short Form-36 scores indicated satisfactory and acceptable postoperative outcomes, respectively. The mean patient satisfaction score was 94.44 and the mean follow-up duration was approximately 17.7 months. The described procedure has been preliminarily shown to be useful in terms of its minimal invasiveness, reproducibility, safety, and effectiveness.

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.

Determination of the Inter- and Intra-rater Reliability of Fusion Assessment in First Tarsometatarsal Joint Arthrodesis Using CT Scan: An Observational Study.

First tarsometatarsal joint arthrodesis is a common procedure performed by podiatrists and orthopedic surgeons. There remains debate on how useful CT scans are in assessing fusion status in the post-operative patient. The purpose of our study was to determine the reliability among both orthopedic surgeons and radiologists in reviewing both postoperative radiographs and CT in order to determine if fusion had occurred in patients undergoing 1st tarsometatarsal arthrodesis. A secondary purpose of this study was to determine if CT offered improved inter- and intra-rater reliability when compared to plain radiographs. Patients who underwent 1st tarsometatarsal arthrodesis were retrospectively reviewed and those who underwent CT post-operatively for persistent pain were identified. Orthopedic surgeons and radiologists then analyzed the radiographs and CT of these patients for union with a threshold for union being set at 50% of the joint being fused. Imaging was then re-evaluated by the same provider 6months later. 24 patients were identified meeting inclusion criteria. Inter-rater reliability and intra-rater reliability for assessment of 1st tarsometatarsal arthrodesis were better with CT compared to radiographs; however, this association was not deemed reliable. Both imaging modalities were not able to assess union status confidently and reliably across reviewers, although CT scan had better intra-rater reliability. While CT is frequently used to assess fusion in patients who have underwent 1st tarsometatarsal arthrodesis, it was not found to be better than radiographs. Practitioners should reconsider the use CT as the gold standard when assessing fusion in this population.

What Do Patients Report Regarding Their Real-World Function Following Concurrent Arthrodesis of the First Tarsometatarsal and First Metatarsophalangeal Joints

First metatarsal phalangeal joint and the first Tarsometatarsal arthrodesis have both been used for deformity correction and treatment of pain and arthritis. Concomitant arthrodesis of the first metatarsophalangeal and first tarsometatarsal joints (Double First Ray Arthrodesis) has rarely been described. We surveyed 29 patients who underwent double first-ray arthrodesis for primary or revision correction of hallux valgus. A custom questionnaire was used to assess their activities of daily living and sports activity at a mean follow-up of 19.6 months (median 18.4 months). Secondary endpoints were return to activity, deformity correction, and arthrodesis healing rate. The primary outcomes showed an excellent return to activities of daily living with 96.6% of patients capable of walking as much as they liked after surgery at a normal pace. About 96.6% reported they felt that their surgery was successful, they had no pain, and the loss of motion at the joint fusion sites did not affect their ability to perform daily activities. Protected walking in a fracture boot was initiated at a mean (SD) of 9.8 (9.9) days. Return to an athletic shoe occurred at a mean (SD) of 44.2 (11.7) days. Full unrestricted activity was at a mean (SD) of 105.2 (19.3) days with 65% of the patient group reporting that their recovery was easier than expected. There was 1 nonunion and no other complications. This data set supports the hypothesis that patients undergoing double first-ray arthrodesis can return to activities of daily living and sports with and low complication rate.

Comparison of Mini Tightrope Intermetatarsal Fixation and Inter-Cuneiform Screw Fixation in Lapidus

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: First metatarso-cuneiform joint arthrodesis for treatment of metatarsus primus varus was originally introduced by Lapidus in 1934. In his technique, fixation was achieved using heavy chromic sutures between the first and second metatarsals to achieve parallel alignment. Since then, the indications and technique for Lapidus procedure have considerably evolved and many modifications have been introduced to Lapidus’s original description. Despite these modifications, recurrence of hallux valgus remains relatively common, either due to malunion at the TMT arthrodesis or through intercuneiform instability. This has informed the approach for additional fixation between the 1st and 2nd rays. This study aims to compare outcomes of inter-cuneiform screw fixation (ICS) and suspensory intermetatarsal fixation (SIM) using a mini-tightrope in terms of deformity correction and maintaining the correction over time. Methods: This was a retrospective comparative study of prospectively collected data for patients who have underwent a Lapidus procedure for hallux valgus between 2012-2022. The electronic medical records were reviewed for demographics, radiologic parameters, and operative data. Radiographic parameters were intermetatarsal angle (IMA), hallux valgus angle (HVA), and sesamoid station on preoperative, 3 months postoperatively and final follow-up. Hallux valgus station was graded from normal, mild, moderate, and severe based on the method used by Agrawal et al. Using a multivariate regression model, a comparison was conducted between suspensory intermetatarsal fixation(SIM) and inter-cuneiform screw fixation(ICS). Univariate linear regression analysis was conducted with the inclusion of covariates' age, smoking, diabetes, and BMI. Comparison of HVA and IMA was conducted using t-test. Results: 65 patients met the inclusion criteria; 20 had ICS, and 45 had SIM. The pre-op IMA improved from 13.57 (3.84) to 6.14 (2.41) degrees postoperatively in the ICS group (p), and from 13.37(3.84) to 6.16 (2.74) degrees postoperatively in the SIM group (p). The final follow-up IMA was 5.9 (2.1) in the ICS group and 6.84 (2.31) in the SIM group, with no difference from post-op values, p=0.123 and, respectively. There was no statistically significant difference between ICS and SIM groups in IMA at pre-op (p=0.41), post-op (p=0.49), and final follow up (p=0.62). There were no statistically significant differences between SIM and ICS groups in HVA preoperatively [37.47(12.21) vs. 40.38(13.59), p=0.19], postoperatively [18.2(10.82) vs. 18.95(10.1),p=0.36] or at final follow up [20.12(9.72) vs 19.33(9.16) ,p=0.38]. Conclusion: Lapidus procedure remains the procedure of choice for severe hallux valgus with predictable correction. Supplementing the first tarsometatarsal arthrodesis with suspensory intermetatarsal fixation using a mini-tightrope achieved similar deformity correction and preservation of correction to intercuneiform screw fixation.

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.

Radiographic Evaluation of First Tarsometatarsal Joint Arthrodesis for Hallux Valgus Deformity: Does the Fusion of the First to the Second Metatarsal Base Reduce the Radiological Recurrence Rate?

Modified Lapidus arthrodesis (MLA) is a well-established treatment option for symptomatic hallux valgus deformity (HVD). However, recurrence of the deformity remains a concern. The goal of this study was to evaluate the effect of an additional intermetatarsal fusion on the radiographic recurrence rate after first tarsometatarsal (TMT-I) arthrodesis. This is a retrospective evaluation of 56 feet that underwent TMT-I arthrodesis for moderate to severe HVD. Twenty-three feet received an isolated arthrodesis of the TMT-I joint (TMT-I), whereas 33 feet received an additional fusion between the base of the first and the second metatarsal bone (TMT-I/II). Various radiological parameters were determined preoperatively, 6 weeks and at a mean of 2 years postoperatively. The intermetatarsal angle (IMA) and the hallux valgus angle (HVA) were significantly lowered at both follow-up evaluations in both groups. In the TMT-I/II group, the initial reduction of HVA was significantly higher (29.3° vs 21.1°). This difference disappeared by the second follow-up, leaving no significant differences between both techniques at final follow-up. Radiological recurrence rates of HVD were comparable in both groups. Isolated TMT-I arthrodesis provides reliable radiological results in the correction of HVD. Whether additional fusion of the first and second metatarsal base should be routinely performed remains unclear. Level 3.

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°).

Multiple factors contributing to the metatarsal head eversion in hallux valgus deformity. A prospective study using weight-bearing CT

PurposeRecently first tarsometatarsal arthrodesis for hallux abducto valgus (HAV) has been advocated as the sole procedure to correct the multiplanar components of the deformity. However, recent debate suggests other factors such as rearfoot pronation and metatarsal torsion affect frontal plane metatarsal eversion and sesamoid positioning. Using weight-bearing CT, 12 feet (12 subjects) with HAV deformities were placed in positions of maximum rearfoot pronation and supination in order to study the effects on metatarsal eversion, sesamoid rotation/displacement, and secondarily the influence of first metatarsal torsion. Sesamoid displacement was quantified by the novel use of the sesamoid displacement angle. Principle resultsAlthough first metatarsal eversion was nearly double in the pronated versus supinated foot, the difference was not statistically significant. Therefore, the bulk of first metatarsal eversion was not secondary to rearfoot eversion. Conversely, a significant positive correlation was found between metatarsal torsion and metatarsal head eversion angles in both supinated and pronated foot positions, with the strongest correlation with rearfoot pronation. Finally, significant increases in sesamoid displacement angles were noted with pronation. Major conclusionsThe findings of the present study support the contention that multiple factors are associated with frontal plane first metatarsal eversion and sesamoid displacement. Weight-bearing CT scanning can be used to effectively evaluate the frontal plane components in HAV deformities. The sesamoid displacement angle appears to be a useful adjunct to evaluating the hallucal sesamoids. For surgical correction of the deformity, consideration should be given to pre-operative weight-bearing CT evaluation of the foot. This can illuminate the effects of rearfoot/medial column pronation and the potential influence of metatarsal torsion on the frontal plane components of this triplane deformity. In this way the potential for post-operative HAV recurrence can be minimized.

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.

Comparison of Radiographic and Clinical Outcomes of First Tarsometatarsal Arthrodesis with the Lapiplasty System vs Cross-Screw Fixation

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: Hallux valgus (HV) is recognized as a triplanar deformity comprising axial abduction, sagittal hypermobility, and coronal pronation of the first metatarsal. A first tarsometatarsal (TMT) arthrodesis may be used to address all three planes of deformity. The Lapiplasty system (Treace Medical Concepts, Inc., Ponte Vedra, FL) was developed to reproducibly address triplanar deformity. However, the Lapiplasty system is costlier than other fixation constructs. Because healthcare is increasingly value-focused, we sought to determine if the more expensive Lapiplasty system improved radiographic outcomes or decreased complication rates over standard cross-screw fixation. We hypothesized that HV patients undergoing first TMT arthrodesis with the Lapiplasty system would have equivalent radiographic correction and similar complication rates when compared to patients treated with cross-screw fixation. Methods: In this multi-center, IRB-approved retrospective study, consecutive series of patients who underwent 1st TMT arthrodesis for HV, either with cross-screw fixation at Institution A, or Lapiplasty at Institution B, were identified by registry search. Inclusion criteria included age over 18 and preoperative and minimum 6-month postoperative weight-bearing AP and lateral radiographs. Exclusion criteria included primary conditions other than hallux valgus and previous first ray surgeries or ipsilateral arthrodeses. Hallux valgus angle (HVA), intermetatarsal angle (IMA), and tibial sesamoid position (TSP) were measured preoperatively and at final follow-up, and clinic notes were reviewed to identify complications and reoperations. To compare cohorts, Mann-Whitney U tests and Fisher's Exact tests were applied for continuous and discrete variables, respectively. To examine preoperative-postoperative changes, Wilcoxon signed rank tests were used. Multivariable regressions tested the effect of fixation constructs on postoperative radiographic parameters, adjusted for preoperative radiographic measurements, age, sex, and BMI. Results: 65 patients were included in each group, with 121 (93.8%) female patients, mean (SD) age 54.7 (14.8), BMI 25.8 (5.2), and radiographic follow-up time 8.9 (6.7) months. The Lapiplasty cohort had greater BMI (26.8 vs. 24.7, P = .048), and there were no significant differences between groups in age, sex distribution, and radiographic follow-up time. Radiographic measurement data is displayed in Table 1. After adjusting for age, sex, BMI, preoperative HVA, and preoperative IMA, fixation with Lapiplasty was significantly associated with lower postoperative IMA (b=-2.03, 95% CI = [-2.78, -1.37], P &lt; .001) and lower postoperative HVA (b= -7.48; 95% CI = [-9.69, -5.26]; P &lt; .001), but not postoperative sesamoid position. There were no significant differences between cohorts in the incidence of complications or reoperations. Conclusion: We found that use of the Lapiplasty system was associated with better radiographic hallux valgus correction, as evidenced by lower postoperative HVAs and IMAs, compared to standard technique with crossing screws. The clinical significance of these findings is unclear, as complication and reoperation rates were similar between groups. Future research assessing longer- term outcomes, patient-reported outcome data, and cost-benefit analysis will be necessary to further compare techniques and fixation systems.

Results of an Interim Analysis of a Prospective Multicenter Study Assessing Radiographic and Patient Outcomes Following Triplanar Tarsometatarsal Arthrodesis with Early Weightbearing

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: The majority of hallux valgus corrections are performed via a two dimensional approach with 1st metatarsal osteotomy and translation in the transverse plane. This approach has demonstrated high long-term recurrence rates. Recent research demonstrates that 87% of hallux valgus deformities are three-dimensional with abnormal frontal-plane rotation of the metatarsal, which cannot be completely addressed with a two dimensional metatarsal osteotomy alone. While correction at the 1st tarsometatarsal (TMT) joint may provide the optimal surgical approach for 3D anatomic restoration at the apex of the deformity, 1st TMT fusion historically entails an extended period of non-weightbearing. This study evaluated the clinical, radiographic, and patient-reported outcomes in patients undergoing instrumented triplanar 1st TMT arthrodesis (TMTA) with a biplanar plating system and protected near-immediate weightbearing. Methods: This is a prospective multicenter study that will continue for 60 months post-operatively. Patients between 14-58 years old with symptomatic hallux valgus (intermetatarsal and hallux valgus angles between 10.0-22.0° and 16.0-40.0°, respectively) and no prior hallux valgus surgery on the operative foot were eligible for this study. Patients were treated with an instrumented TMTA procedure using a biplanar plating system with protected near-immediate weightbearing. Several outcomes (radiographic, return to weightbearing and activities, pain measured by visual analog scale (VAS), Manchester-Oxford Foot Questionnaire (MOxFQ), and Patient Reported Outcomes Measurement Information System (PROMIS)) were evaluated post-operatively. Two independent fellowship trained musculoskeletal radiologists reviewed all radiographic data. These interim results are limited to patients completing at least 6 months of follow-up. Results: 165 patients underwent TMTA with at least 6 months follow-up (mean (SD): 17.8 (7.7); min, max: 5.8, 37.3). Mean age was 41.0 (range:14-58) years; 91.5% of patients were female. Mean (SD) days to protected weightbearing in CAM boot and return to full work were 8.4 (7.7) and 56.8 (45.6), respectively. Significant improvements from baseline in HVA, IMA, and TSP (Table 1), VAS score, MOxFQ and PROMIS domains were observed as early as 6 weeks post-procedure. At 12 months, mean (95% CI) change in VAS was -3.7(-4.0, -3.3); Walking/Standing (MOxFQ) change was -35.2 (-39.6, -30.8); and Physical Function (PROMIS) change was 8.7 (7.1, 10.3). Fifteen (9.1%) patients experienced hardware complications, yet maintained radiographic correction to date. No patients (0/58) with 24 months follow-up have experienced recurrence. Conclusion: These interim findings support that TMTA with biplanar plating is successful in correcting the 3D hallux valgus deformity with early return to weightbearing while demonstrating favorable clinical and patient-reported outcomes. Patients exhibited meaningful pain reduction after surgery and were able to return to full, unrestricted work and activities in less than two months, on average. Statistically significant improvements in patients' health-related quality of life were observed at 6 and 12 months, post-operatively. Patients will continue to be followed for up to 60 months with additional evaluations for complications, 24-month recurrence, and patient satisfaction.

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.

Intraoperative Technical Tips to Improve Fusion Between the First and Second Metatarsals in the Original Lapidus Procedure.

The modified Lapidus procedure (MLP), which consists of fusion between the first metatarsal (M1) and medial cuneiform, has been widely performed with satisfactory clinical outcomes, but it has a variable nonunion rate ranging between 4% and 10% and loss of correction in up to 5.8% of the cases. Excessive motion around the site of tarsometatarsal arthrodesis, specially at the intercuneiform joint, is probably the reason. The original Lapidus procedure (OLP), which includes fusion of the M1 to second metatarsal (M2), may be beneficial in preventing nonunion and recurrence. The objective of this study was to describe intraoperative technical tips in the OLP to improve M1 to M2 fusion, which may prevent complications. Since the Lapidus procedure continues to gain popularity, it is the authors opinion that the OLP requires special attention because it is a more technically demanding surgery compared to the MLP.Level of Evidence: Level V: Expert opinion.

One- and Two-Year Analysis of a Five-Year Prospective Multicenter Study Assessing Radiographic and Patient-Reported Outcomes Following Triplanar First Tarsometatarsal Arthrodesis With Early Weightbearing for Symptomatic Hallux Valgus

We report one- and 2-year results of a prospective, 5-year, multicenter study of radiographic, clinical, and patient-reported outcomes following triplanar first tarsometatarsal arthrodesis with early weightbearing. One-hundred and seventeen patients were included with a mean (95% confidence interval [CI]) follow-up time of 16.6 (15.5, 17.7) months. Mean (95% CI) time to weightbearing in a boot walker was 7.8 (6.6, 9.1) days, mean time to return to athletic shoes was 45.0 (43.5, 46.6) days, and mean time to return to unrestricted activity was 121.0 (114.5, 127.5) days. There was a significant improvement in radiographic measures with a mean corrective change of -18.0° (-19.6, -16.4) for hallux valgus angle, -8.3° (-8.9, -7.8) for intermetatarsal angle and -2.9 (-3.2, -2.7) for tibial sesamoid position at 12 months (n = 108). Additionally, there was a significant improvement in patient-reported outcomes (Visual Analog Scale, Manchester-Oxford Foot Questionnaire, and Patient-Reported Outcomes Measurement Information System) and changes were maintained at 12 and 24 months postoperatively. There was 1/117 (0.9%) reported recurrence of hallux valgus at 12 months. There were 16/117 (13.7%) subjects who experienced clinical complications of which 10/117 (8.5%) were related to hardware. Of the 7/117 (6.0%) who underwent reoperation, only 1/117 (0.9%) underwent surgery for a nonunion. The results of the interim report of this prospective, multicenter study demonstrate favorable clinical and radiographic improvement of the HV deformity, early return to weightbearing, low recurrence, and low rate of complications.

Results of an Interim Analysis of a Prospective Multicenter Study Assessing Radiographic and Patient Outcomes Following Triplanar Tarsometatarsal Arthrodesis with Early Weightbearing

Category:Bunion; Midfoot/ForefootIntroduction/Purpose:The majority of hallux valgus corrections are performed via a two dimensional approach with 1st metatarsal osteotomy and translation in the transverse plane. This approach has demonstrated high long-term recurrence rates. Recent research demonstrates that 87% of hallux valgus deformities are three-dimensional with abnormal frontal-plane rotation of the metatarsal, which cannot be completely addressed with a two dimensional metatarsal osteotomy alone. While correction at the 1st tarsometatarsal (TMT) joint may provide the optimal surgical approach for 3D anatomic restoration at the apex of the deformity, 1st TMT fusion entails an extended period of non-weightbearing. This study evaluated the clinical, radiographic, and patient-reported outcomes in patients undergoing instrumented triplanar 1st TMT arthrodesis (TMTA) with a biplanar plating system and protected near-immediate weightbearing.Methods:This is a prospective multicenter study that will continue for 60 months post-operatively. Patients between 14-58 years old with symptomatic hallux valgus (intermetatarsal and hallux valgus angles between 10.0-22.0° and 16.0-40.0°, respectively) and no prior hallux valgus surgery on the operative foot are eligible for this study. Patients are treated with an instrumented TMTA procedure using a biplanar plating system with protected near-immediate weightbearing. Several outcomes (radiographic, range of motion (ROM), return to weightbearing and activities, pain measured by visual analog scale (VAS), Manchester-Oxford Foot Questionnaire (MOxFQ), and Patient Reported Outcomes Measurement Information System (PROMIS)) are evaluated post- operatively. Two independent fellowship trained musculoskeletal radiologists reviewed all radiographic data. These interim results are limited to patients completing at least 6 months of follow-up.Results:At time of analysis, 121 patients had undergone TMTA with at least 6 months of follow-up. Mean age was 40.6 (range:15- 58) years, and 91% of patients were female. Mean (SD) days to protected weightbearing in CAM boot, return to work, and return to full work were 8.2 (6.8), 24.0 (29.5), and 51.2 (44.0), respectively. Significant improvements (p<0.05) from baseline in HVA, IMA, and TSP (Table 1), VAS score, MOxFQ and PROMIS domains were observed as early as 6 weeks post-procedure. At 12 months, mean (95% CI) change in VAS score was -4.0 (-4.5, -3.6); Walking/Standing, Pain, and Social Interaction (MOxFQ domains) change was -38.6 (-43.6, -33.5), -41.0 (-45.8, -36.2), and -40.5 (-45.3, -35.7), respectively; and physical function (PROMIS) change was 8.7 (6.6, 10.8).Conclusion:These interim findings support that TMTA with biplanar plating is successful in correcting the 3D hallux valgus deformity with early return to weightbearing while demonstrating favorable clinical and patient-reported outcomes. Patients exhibited meaningful pain reduction after surgery and were able to return to full, unrestricted work and activities in less than two months, on average. Statistically significant improvements in patients' health-related quality of life were observed at 6 and 12 months, post-operatively. Patients will continue to be followed for up to 60 months with additional evaluations for complications, 24-month recurrence, and patient satisfaction.