Medially positioned plate in first metatarsophalangeal joint arthrodesis

Objective The purpose of this study was to biomechanically compare the stability of first metatarsophalangeal (MTP1) joint arthrodesis with dorsally and medially positioned plates. Methods A physical model of the MTP1 joint consists of printed synthetic bones, a titanium locking plate and screws. In the experiments, samples with dorsally and medially positioned plates were subjected to loading of ground load character in a universal testing machine. Force-displacement relations and relative displacements of bones were recorded. The obtained results were used to validate the corresponding finite element models of the MTP1 joint. Nonlinear finite element simulations of the toe-off phase of gait were performed to determine the deformation and stress state in the MTP1 joint for two positions of the plate. Results In numerical simulations, the maximum displacement in the dorsal direction was noticed at the tip of the distal phalanx and was equal to 19.6 mm for the dorsal plate and 9.63 mm for the medial plate for a resultant force of 150 N. Lower relative bone displacements and smaller plastic deformation in the plate were observed in the model with the medial plate. Stress values were also smaller in the medially positioned plate and locking screws compared to fixation with the dorsal plate. Conclusions A medially positioned locking plate provides better stability of the MTP1 joint than a dorsally positioned plate due to greater vertical bending stiffness of the medial plate. Smaller relative bone displacements observed in fixation with the medial plate may be beneficial for the bone healing process. Moreover, lower stress values may decrease the risk of complications associated with hardware failure.

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First metatarsophalangeal fusion with dorsal plate: clinical outcomes

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02453-y ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Giuseppe Restuccia ◽

Fabio Cosseddu ◽

Andrea del Chiaro ◽

Matteo Ceccoli ◽

Alessandro Lippi ◽

...

Keyword(s):

Weight Bearing ◽

Metatarsophalangeal Joint ◽

Wound Dehiscence ◽

Dorsal Plate ◽

First Metatarsophalangeal Joint ◽

Low Profile ◽

Significant Difference ◽

The Stability ◽

Dorsal Plating

Abstract Background First metatarsophalangeal joint (MTPJ) fusion is the most effective technique for the treatment of MTPJ primary arthritis, severe hallux valgus and failure of primary corrective surgery of these conditions. It can be achieved through different techniques. We evaluated the outcomes in a cohort of patients treated with dorsal plate arthrodesis. Materials and methods We treated 30 feet for 28 patients; the mean follow-up was 35 months. For each foot, we collected radiological and clinical assessment, with the visual analogue scale (VAS) for pain and the Manchester and Oxford Foot questionnaire (MOFQ). The technique consisted in a cup and cone arthrodesis with the application of a low profile dorsal plate. Patients were allowed for immediate weight bearing. Results Consolidation was achieved in all cases; in 29 cases, radiographic union was recorded within 6 months from surgery, in one case after 9 months. Comparison between the preoperative and postoperative of VAS and MOXFQ values showed a statistically significant difference (p < 0.05). Only one case developed wound dehiscence as complication. Conclusions Even if there is still a debate regarding the best system for MTPJ fusion, we believe cup and cone fusion with dorsal plating is an effective method. Moreover, the stability of the osteosynthesis obtained allows for immediate post-operative weight bearing, making patients able to return soon to their normal life. Trial registration We present a retrospective study; all patients enrolled were retrospectively registered.

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Outcomes of First Metatarsophalangeal Joint Fusion in Patients with Greater Than Fifteen Percent Intermetatarsal Angle. Is Lag Screw Essential?

Foot & Ankle Orthopaedics ◽

10.1177/2473011417s000361 ◽

2017 ◽

Vol 2 (3) ◽

pp. 2473011417S0003

Author(s):

Ashish Shah ◽

Parke Hudson ◽

Ibukunoluwa Araoye ◽

Zachariah Pinter ◽

Girish Motwani ◽

...

Keyword(s):

Locking Plate ◽

Screw Fixation ◽

Metatarsophalangeal Joint ◽

Dorsal Plate ◽

Chi Square ◽

First Metatarsophalangeal Joint ◽

Lag Screw ◽

Wide Range ◽

Significant Difference ◽

Student’S T

Category: Midfoot/Forefoot Introduction/Purpose: Metatarsophalangeal arthrodesis has usually been performed using a dorsal plate to immobilize the MTP joint with or without lag screw fixation. Data in the literature is sparse on outcomes of dorsal plate plus lag screw fixation, especially in patients with IMA greater than 15 percent. Our objective was to compare IMA correction outcomes and union rates between dorsal plate only fusions and dorsal plate plus lag screw fixation in patients with IMA greater than 15 percent. Methods: We retrospectively reviewed the charts of 36 patients (39 feet) who underwent first MTP joint arthrodesis for moderate to severe HV deformity between 2011 and 2015. Average age was 61 (range, 39 to 84) years. There were 24 females and 12 males. A single surgeon performed all operations. Joints were immobilized postoperatively using either dorsal locking plate alone or dorsal locking plate with a lag screw. Union (at least 3 bridging cortices) was determined radiographically at 6 weeks, 3 months, 6 months and yearly. All suspect nonunions were examined with CT. Other radiographic parameters examined included preoperative and postoperative hallux valgus, intermetatarsal, and dorsiflexion angles (HVA, IMA, and DFA respectively). Student’s t test was used to compare group means while Pearson’s Chi square test was used to compare group rates. Results: Overall union rate was 82.1% (32/39). There was no significant difference in union rates between the two groups (dorsal plate only = 81.5% (22/27), dorsal plate plus lag screw group = 83.3% (10/12)) (P > 0.05). Average follow-up was 9 (range 7 to 35) months. Overall, the average IMA correction was 4.7 (preoperative = 17.8, postoperative = 13.1) degrees. Average IMA corrections were 4.7 and 4.54 degrees in the dorsal plate only group and dorsal plate plus lag screw groups respectively. Overall, average HVA correction was 21 (preoperative = 39.5, postoperative = 18.5) degrees. Conclusion: Our findings indicate that there is no difference in the fusion rates between both patient groups with IMA greater than fifteen percent. Because other published studies have a wide range of IMAs preoperatively, our study represents more attainable goals in patients with severe (IMA greater than 15%) deformities. In addition, our findings suggest that in such patients, MTP arthrodesis may not be sufficient as a standalone procedure for correction of IMA. Additional proximal osteotomy may be required for correction of the IMA.

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Arthrodesis of the First Metatarsophalangeal Joint: A Biomechanical Study of Internal Fixation Techniques

Foot & Ankle ◽

10.1177/107110079301400705 ◽

1993 ◽

Vol 14 (7) ◽

pp. 395-399 ◽

Cited By ~ 84

Author(s):

Mark J. Curtis ◽

Mark Myerson ◽

Riyaz H. Jinnah ◽

Quentin G.N. Cox ◽

Ian Alexander

Keyword(s):

Internal Fixation ◽

Testing Machine ◽

Biomechanical Testing ◽

Metatarsophalangeal Joint ◽

Biomechanical Study ◽

Materials Testing ◽

Dorsal Plate ◽

First Metatarsophalangeal Joint ◽

Joint Surfaces ◽

Fixation Techniques

This study compares the strength and rigidity of four methods of internal fixation for arthrodesis of the first metatarsophalangeal joint. Ten matched pairs of cadaveric first rays were harvested and arthrodesis performed by one of four techniques: (1) planar excision of joint surfaces and fixation with crossed Kirschner wires, (2) planar excision of joint surfaces and internal fixation with a dorsal plate and screws, (3) planar excision of joint surfaces and internal fixation with an interfragmentary screw, or (4) excision of the joint surfaces using powered conical reamers and fixation with an interfragmentary lag screw. Biomechanical testing with a Bionix 858 materials testing machine was carried out, applying a plantar force utilizing principles of cantilever loading. Force applied and displacement of the arthrodesis were recorded. Of the four methods tested, bony preparation with power conical reamers and supplementary interfragmentary screw fixation was the most stable.

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Risk Factors for Non-union in First MTPJ Arthrodesis

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00356 ◽

2018 ◽

Vol 3 (3) ◽

pp. 2473011418S0035 ◽

Cited By ~ 1

Author(s):

Andrew Molloy ◽

Clifford Butcher ◽

Lyndon Mason

Keyword(s):

Risk Factors ◽

Relative Risk ◽

Hallux Valgus ◽

Locking Plate ◽

Univariate Analysis ◽

Dorsal Plate ◽

First Metatarsophalangeal Joint ◽

Non Union ◽

Severe Hallux Valgus

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus occurs in up to 1 in 40 adults with 1st MTPJ arthrodesis being the gold standard operation for advanced disease. Our aim was to retrospectively identify risk factors for delayed / non-union of first metatarsophalangeal joint arthrodesis using a dorsal plate with cross screw. Methods: Case note and radiograph analysis was performed for operations between April 2014 and April 2016 with at least 6 months post-operative follow up. Union was defined as bridging bone across the fusion site on AP and lateral radiographic views with no movement or pain at the MTPJ on examination. All patients operations were performed or directly supervised by one of three fellowship trained consultant foot surgeons. Surgery was performed through a dorsal approach using a dorsal locking plate with compression screw. Blinded preoperative AP radiographs were analysed for the presence of a severe hallux valgus angle equal to or above 40 degrees. Intra-observer reliability was acceptable (95% CI: 1.6-2.3 degrees). Smoking and co-morbidities underwent univariate analysis for significance. Following initial result results, surgery in patients with arthritic hallux valgus were fixed using a separate plantar to dorsal / medial to lateral lag screw and dorsal locking plate Results: 71 patients with a mean age of 61 years (range, 29 to 81) comprised the initial patient group. Mean follow up time was 13 months for both union and nonunion groups (range 6 to 30 months). 7 patients were identified as delayed or nonunion (9.9%). All had hallux valgus angles of >25%. Age, diabetes, COPD and rheumatoid arthritis did not show significant associations with non-union. All smokers progressed to union (n = 17). Moderate to severe hallux valgus (relative risk: 1.29, p < 0.005) and under correction of >25 valgus at the MTPJ (relative risk: 14.44, p < 0.001) were significantly associated with non/delayed union. In the second group, 18 patients of similar demographics, there were no failure of reductions and 100% union rate Conclusion: Preoperative moderate to severe hallux valgus and under-correction of deformity are the most significant risk factors for non-union. The construct used for fixation needs to be chosen on the basis of the deforming forces. If so, excellent union rates can be achieved

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First Metatarsophalangeal Joint Arthrodesis

Foot & Ankle Orthopaedics ◽

10.1177/2473011417752674 ◽

2018 ◽

Vol 3 (3) ◽

pp. 247301141775267 ◽

Cited By ~ 1

Author(s):

Paola Filomeno ◽

Julio López

Keyword(s):

Patient Satisfaction ◽

Plate Fixation ◽

Metatarsophalangeal Joint ◽

Functional Improvement ◽

Dorsal Plate ◽

Level Of Evidence ◽

First Metatarsophalangeal Joint ◽

Joint Fusion ◽

Vas Scores ◽

Satisfaction Rates

Background: First metatarsophalangeal (MTP) joint arthrodesis can be fixed using either a dorsal plate or crossed screws. However, there is considerable difference in the cost of these implants, and it is not known if there is sufficient difference in outcome that might justify this cost difference. Our aim was to compare the functional results and patient satisfaction rates after first MTP joint arthrodesis in a group of patients using the same surgical technique except for the fixation devices. Methods: A prospective cohort of 27 patients who underwent first MTP joint fusion by the same surgeon using 2 crossed screws or a single screw with a dorsal plate was recruited over a 3-year period. Demographic information, patient satisfaction rates, complications, and union rates were evaluated. American Orthopaedic Foot & Ankle Society (AOFAS) and visual analog scale (VAS) scoring systems were used pre- and postoperatively to compare the functional outcomes. Thirty consecutive procedures (screws, n = 15; plate, n = 15) were performed. Age (55.8 ± 11.1 vs 63.3 ± 12.4 years for screws and plate respectively; P = .091) and female gender percentages (80% and 73%, P = .666) were similar between groups. Results: The overall union rate was 93% with no differences between groups. AOFAS and VAS scores improved significantly postoperatively for each technique, and no differences were found between the two in the improvement in AOFAS (42.4 ± 8.0 vs 44.3 ± 8.2, screws and plate respectively; P = .520) and VAS scores (66.0 ± 5.4 vs 69.0 ± 6.9; P = .195). The implant cost for screws was $40 and for dorsal plate, $328. Conclusions: First MTP joint fusion using either screws or plate fixation results in an improvement in AOFAS and VAS scores. Functional improvement and patient satisfaction did not differ between the 2 techniques, despite a considerable difference in cost between the two methods of fixation. Level of Evidence: Level III, prospective comparative study.

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Design, Modeling and Finite Element Static Analysis of a New Two Axis Solar Tracker Using SolidWorks/COSMOSWorks

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.446-447.738 ◽

2013 ◽

Vol 446-447 ◽

pp. 738-743 ◽

Cited By ~ 4

Author(s):

Fateh Ferroudji ◽

Toufik Ouattas ◽

Chérif Khélifi

Keyword(s):

Finite Element ◽

Static Analysis ◽

Safety Factor ◽

Equivalent Stress ◽

Maximum Displacement ◽

3D Cad ◽

Optimum Position ◽

Maximum Equivalent Stress ◽

Solar Tracker ◽

The Stability

This paper presents the now design, modeling and static analysis of a new two-axis solar tracker (Azimuth and Altitude). The tracker is an electro-hydraulic device that keeps photovoltaic panels in an optimum position perpendicularly to the solar radiation during daylight hours. The tracker of 24 m² panel’s size was designed using the SolidWorks 3D CAD software. The finite element method (FEM) is adopted to ensure the stability and the reliability of the tracker. COSMOSWorks was used to determine displacement, equivalent stress and safety factor of the tracker under its own weight and wind load critical, namely wind speed of 130 km/h. Simulation results show that the maximum displacement of the structure is 1.18 mm, the level of the maximum equivalent stress is 74.43 MPa and the safety factor is about 3. The tracker structure completely satisfies the design requirements.

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Biomechanical Effects of Various Bone-Implant Interfaces on the Stability of Orthodontic Miniscrews: A Finite Element Study

Journal of Healthcare Engineering ◽

10.1155/2017/7495606 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Fabing Tan ◽

Chao Wang ◽

Chongshi Yang ◽

Yuanding Huang ◽

Yubo Fan

Keyword(s):

Finite Element ◽

Surrounding Tissue ◽

Homogeneous Distribution ◽

Loss Of Stability ◽

Stress Strain ◽

Maximum Displacement ◽

Element Analysis ◽

Bone Implant ◽

Prosthetic Implant ◽

The Stability

Introduction. Osseointegration is required for prosthetic implant, but the various bone-implant interfaces of orthodontic miniscrews would be a great interest for the orthodontist. There is no clear consensus regarding the minimum amount of bone-implant osseointegration required for a stable miniscrew. The objective of this study was to investigate the influence of different bone-implant interfaces on the miniscrew and its surrounding tissue. Methods. Using finite element analysis, an advanced approach representing the bone-implant interface is adopted herein, and different degrees of bone-implant osseointegration were implemented in the FE models. A total of 26 different FE analyses were performed. The stress/strain patterns were calculated and compared, and the displacement of miniscrews was also evaluated. Results. The stress/strain distributions are changing with the various bone-implant interfaces. In the scenario of 0% osseointegration, a rather homogeneous distribution was predicted. After 15% osseointegration, the stress/strains were gradually concentrated on the cortical bone region. The miniscrew experienced the largest displacement under the no osseointegra condition. The maximum displacement decreases sharply from 0% to 3% and tends to become stable. Conclusion. From a biomechanical perspective, it can be suggested that orthodontic loading could be applied on miniscrews after about 15% osseointegration without any loss of stability.

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A Rare Combination of Brachymetatarsia and Congenital Hallux Varus:

Journal of the American Podiatric Medical Association ◽

10.7547/0003-0538-104.1.85 ◽

2014 ◽

Vol 104 (1) ◽

pp. 85-89 ◽

Cited By ~ 3

Author(s):

Vanessa Froehlich ◽

Markus Wuenschel

Keyword(s):

Locking Plate ◽

Callus Formation ◽

Metatarsophalangeal Joint ◽

Metatarsal Bone ◽

First Metatarsophalangeal Joint ◽

First Metatarsal ◽

Hallux Varus ◽

Metatarsal Bones ◽

Patient Reported ◽

Surgery First

Hallux varus is defined as a medial deviation of the phalanx at the first metatarsophalangeal joint and can be congenital or acquired. Brachymetatarsia is defined as shortening of the metatarsal bones. A combination of hallux varus and brachymetatarsia is rare. A 15-year-old girl presented to our outpatient clinic complaining of problems with her feet. A distinctive hallux varus was present bilaterally combined with a brachymetatarsia of the first metatarsals. The patient reported discomfort. She was restricted in her activities and had severe psychological strain owing to the deformity. We decided on surgery. First, a Pennig MiniFixator for callus distraction of the first metatarsal bone was applied. Owing to the increased plantar subluxation of the phalanx during distraction, an extension of the external fixator was administered so that the hallux could be repositioned to a physiologically satisfying position. After sufficient callus formation, the hardware was removed 14 weeks after surgery. Thereafter, the phalanx moved back to the subluxed position. Finally, an arthrodesis of the first metatarsophalangeal joint was performed with a locking plate. Surgery should not be made only for cosmesis and associated psychological aspects; but, discomfort should be the deciding factor. The postoperative clinical and cosmetic results in our case were good, and the patient was quite satisfied. There was no longer any preoperative discomfort and pain.

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Effect of Dorsal Plate Positioning on Dorsiflexion Angle in Arthrodesis of the First Metatarsophalangeal Joint

Foot & Ankle International ◽

10.1177/1071100714534419 ◽

2014 ◽

Vol 35 (8) ◽

pp. 802-808 ◽

Cited By ~ 6

Author(s):

Jesse T. Lewis ◽

Andrew E. Hanselman ◽

Trapper A. J. Lalli ◽

Justin L. Daigre ◽

Robert D. Santrock

Keyword(s):

Metatarsophalangeal Joint ◽

Dorsal Plate ◽

First Metatarsophalangeal Joint

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Comparison of two different screw trajectories in the treatment of oblique scaphoid fractures: A mechanical study on composite bone models

Joint Diseases and Related Surgery ◽

10.52312/jdrs.2021.15 ◽

2021 ◽

Vol 32 (2) ◽

pp. 377-382

Author(s):

Bülent Kılıç ◽

Mustafa Çalışkan ◽

Anıl Agar ◽

Bora Uzun ◽

Fatih Ertem ◽

...

Keyword(s):

Testing Machine ◽

Axial Loading ◽

Scaphoid Bone ◽

Maximum Displacement ◽

Bone Model ◽

Scaphoid Fractures ◽

Significant Difference ◽

Mechanical Study ◽

The Stability ◽

Composite Bone

Objectives: In this mechanical study, we aimed to compare two different screw trajectories in terms of durability against axial loads on oblique scaphoid fractures using composite bone models. Materials and methods: Oblique osteotomies were made along the dorsal sulcus of 14 composite scaphoid bone models. Following this, all bone models were randomly classified. One group of bones were fixed with a screw placed perpendicular to the osteotomy line and the other group was fixed with a screw placed centrally down the long axis of the scaphoid bone. Each scaphoid bone model was positioned on a mechanical testing machine. Subsequently, axial loading tests were applied on each bone model to measure the amount of loading required to cause 2-mm displacement and failure on the osteotomy side and maximum displacement at the time of failure on scaphoid bone models. Results: There was no statistically significant difference in load to 2-mm displacement and failure between the two groups (p>0.05). Also, there was no statistically significant difference between the two groups in terms of maximum displacement seen on failure (p>0.05). Conclusion: In our study, we found that the stability of the screws which laid perpendicular to the fracture line and parallel to the long axis of the scaphoid was the same in fixing oblique scaphoid fractures.

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