Weight-bearing recommendations after first metatarsophalangeal joint arthrodesis fixation: a biomechanical comparison

Comparative analysis of mechanical conditions in bone union following first metatarsophalangeal joint arthrodesis with varied locking plate positions: A finite element analysis

BACKGROUND

First metatarsophalangeal joint arthrodesis is a typical medical treatment performed in cases of arthritis or joint deformity. The gold standard for this procedure is arthrodesis stabilisation with the dorsally positioned plate. However, according to the authors' previous studies, medially positioned plate provides greater bending stiffness. It is worth to compare the mechanical conditions for bone formation in the fracture callus for both placements of the locking plate.

METHODS

Two finite element models of the first metatarsophalangeal joint with the dorsally and medially positioned plate were defined in the Abaqus software to simulate differentiation of the fracture callus. A simplified load application, i.e. one single step per each day and the diffusion of the mesenchymal stem cells into the fracture region were assumed in an iterative hardening process. The changes of the mesenchymal stem cells into different phenotypes during the callus stiffening were governed by the octahedral shear strain and interstitial fluid velocity according to Prendergast mechanoregulation theory. Basing on the obtained results the progress of the cartilage and bone tissues formation and their distribution within the callus were compared between two models.

FINDINGS

The obtained results suggest that after 6 weeks of simulation the healing progress is in general comparable for both plates. However, earlier closing of external callus was observed for the medially positioned plate which had greater vertical bending stiffness. This process enables faster internal callus hardening and promotes symmetrical bridging.

Plantar pressure analysis of different orthoses in patients after first metatarsophalangeal joint arthrodesis

BACKGROUND

There is no gold standard for a walking orthosis after first metatarsophalangeal joint (MTPJ) arthrodesis surgery. Evaluation of plantar pressure measures and patient perceptions for different orthoses may assist surgeons to choose a postsurgery orthotic. The purpose of this study was to measure plantar pressure under the distal first ray during walking and patient perceptions of comfort, stability, and preference with 4 different orthoses in patients with a history of first MTPJ arthrodesis.

METHODS

Crossover study in a university laboratory. Eleven patients volunteered (8 female, 3 male, age = 59.4 ± 9.1 years, 21.9 ± 17.5 months since surgery) who had a unilateral first MTPJ arthrodesis procedure more than 6 months before study participation. Four orthosis conditions were evaluated in all participants: patient's shoe, carbon fiber insert, OrthoWedge, and Post-Op Shoe. We analyzed peak plantar pressure and pressure-time integral under the whole foot and the distal first ray as well as recorded subjective rating for comfort and stability. Rank ordered for preferred orthosis.

RESULTS

OrthoWedge had significantly lower whole-foot and distal first ray peak pressure than the other conditions. The pressure-time integral for the OrthoWedge was significantly less than the Carbon Fiber Insert and Post-Op Shoe. For stability, comfort, and condition preference, the OrthoWedge was ranked lowest among the 4 conditions.

CONCLUSIONS

The OrthoWedge generated the lowest peak plantar pressure but was subjectively ranked as the least preferred orthosis. This discrepancy between objective biomechanical and subjective comfort measures must be weighed as surgeons prescribe an orthosis to patients after first MTPJ arthrodesis.

Effect of lag screw on stability of first metatarsophalangeal joint arthrodesis with medial plate

Background

First metatarsophalangeal joint (MTP-1) arthrodesis is a commonly performed procedure in the treatment of disorders of the great toe. Since the incidence of revision after MTP-1 joint arthrodesis is not insignificant, a medial approach with a medially positioned locking plate has been proposed as a new technique. The aim of the study was to investigate the effect of the application of a lag screw on the stability and strength of first metatarsophalangeal joint arthrodesis with medial plate.

Methods

The bending tests in a testing machine were performed for models of the first metatarsal bone and the proximal phalanx printed on a 3D printer from polylactide material. The bones were joined using the locking titanium plate and six locking screws. The specimens were divided into three groups of seven each: medial plate and no lag screw, medial plate with a lag screw, dorsal plate with a lag screw. The tests were carried out quasi-static until the samples failure.

Results

The addition of the lag screw to the medial plate significantly increased flexural stiffness (41.45 N/mm vs 23.84 N/mm, p = 0.002), which was lower than that of the dorsal plate with a lag screw (81.29 N/mm, p < 0.001). The similar maximum force greater than 700 N (p > 0.50) and the relative bone displacements lower than 0.5 mm for a force of 50 N were obtained for all fixation techniques.

Conclusions

The lag screw significantly increased the shear stiffness in particular and reduced relative transverse displacements to the level that should not delay the healing process for the full load of the MTP-1 joint arthrodesis with the medial plate. It is recommended to use the locking screws with a larger cross-sectional area of the head to minimize rotation of the medial plate relative to the metatarsal bone.

Immediate Weightbearing Following First Metatarsal Phalangeal Joint Arthrodesis With 2 Nickel Titanium Alloy Staples

The use of staples has been shown to be a reasonable fixation technique to achieve stability of a first MTPJ arthrodesis. Although it has been shown to be a weaker construct than crossed screws or plate and screw combinations, their ease of insertion, low profile, and stability make them a desirable choice for first MTPJ arthrodesis fixation. However, because of this relative weakness, the question remains whether immediate weightbearing when using staples is advisable. The aim of this study is to determine whether the use of 2 nickel-titanium alloy (NITINOL) staples, placed at 90 degrees to one another is a stable enough construct to support full, immediate weightbearing following first MTPJ arthrodesis. We performed a retrospective chart review of patients undergoing first MTPJ arthrodesis by a single surgeon utilizing 2 NITINOL staples placed at 90 degrees to one another. Patients were allowed to be fully weightbearing immediately postoperatively. Forty-seven of 50 (94%) patients achieved complete radiologic consolidation of fusion at 12 weeks, with only 3 requiring revision surgery for nonunion. All of the patients requiring revision surgery for nonunion, had preoperative diagnosis of hallux abducto valgus. We concluded that the use of 2 NITINOL staples placed at 90 degrees to one another is a viable option for first MTPJ arthrodesis, and immediate weightbearing does not increase rate of nonunion or incidence of revision surgery when compared to other fixation techniques.

Evaluating the Biomechanical Integrity of Various Constructs Utilized for First Metatarsophalangeal Joint Arthrodesis: A Systematic Review

The first metatarsophalangeal (MTP) joint is a frequently loaded joint, handling loads up to 90% of bodyweight. First MTP arthrodesis is a frequently performed procedure designed to improve pain in patients with degenerative MTP joint disease. There are a wide variety of fixation constructs for this procedure without consensus on the most effective method. The purpose of this study was to compare the biomechanical integrity of various constructs utilized for first MTP arthrodesis. A systematic review of the literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, CINAHL, MEDLINE, and Web of Science databases were searched from inception to 18 June 2023. Articles discussing the biomechanics of first MTP arthrodesis constructs were included. A total of 168 articles were retrieved. A total of 20 articles involving 446 cadaveric and synthetic bone constructs were included in the final review. Of the six articles comparing dorsal plating with compression screws to crossed interfragmentary screws, five found that dorsal plating had significantly higher stiffness. All three studies assessing shape-memory staples found them to be significantly less stable than crossed screws or dorsal plates alone. Both studies evaluating fully threaded screws found them to be stronger than crossed cancellous screws. Wedge resections have been shown to be 10 times stronger than standard planar or conical excision. Dorsal plating with compression screws is the gold standard for MTP arthrodesis. However, more research into newer methods such as fully threaded screws and wedge resections with an increased focus on translation to clinical outcomes is needed.

Canine ex vivo tarsal arthrodesis: fixation by using a new bone tissue glue

Introduction

Arthrodesis, performed as a salvage surgical procedure to treat intractable joint conditions in dogs and cats, is associated with a high incidence of complications intra and postoperative, proving the need for improved and new techniques in arthrodesis surgery. Adding a new resorbable bone glue to the arthrodesis could potentially add fixation strength and lower complications. The objectives of this experimental ex vivo biomechanical study were therefore to develop a biomechanical test model of partial tarsal arthrodesis and to determine whether the new resorbable bone glue (phosphoserine modified cement) produced measurable fixation strength in canine calcaneoquartal arthrodesis, without orthopedic implants.

Methods

Four biomechanical test models with a total of 35 canine tarsal joints were used. Soft tissues were dissected to 4 different test models with variable contributions from soft tissues. The calcaneoquartal joint was prepared as in vivo arthrodesis and the glue was applied to joint surfaces as a liquid/putty (0.4 cc). After curing for 24 h, a shear force was applied to the joint (1 mm per minute) and the failure strength was recorded.

Results

Calcaneoquartal joints, where all soft tissues had been completely resected and fixated with glue (1-1.5 cm2 joint surface), withstood 2-5 mm of displacement and an average of 100 ± 58 N/cm2 of shear force (Model 1). Similar adhesive fixation strengths were obtained in Model 2 and 3 with increasing contributions from soft tissues (80 ± 44 and 63 ± 23 N/cm2, p = 0.39, ANOVA).

Conclusion

The developed biomechanical model was sensitive enough to measure differences in fixation strengths between different glue formulations. The average fixation strength (60-100 N/cm2) should be strong enough to support short-term load bearing in medium sized canines (20 kg). The developed cadaver biomechanical test model is of potential use for other arthrodesis studies. The new resorbable glue can potentially contribute to stability at arthrodesis surgery, acting as a complement to today's standard fixation, metal implants.

Factors Associated With Nonunion in Arthrodesis of the First Metatarsophalangeal Joint: A Multicenter Retrospective Cohort Study

BACKGROUND

Arthrodesis of the first metatarsophalangeal joint is the current treatment of choice for symptomatic advanced hallux rigidus and moderate-to-severe hallux valgus. There are different methods to perform arthrodesis, yet no consensus on the best approach. Therefore, this study aimed to determine the effects of preoperative and postoperative hallux valgus angle (HVA), joint preparation and fixation technique, and postoperative immobilization on the incidence of nonunion.

METHODS

A retrospective multicenter cohort study was performed that included 794 patients. Univariate and multiple logistic regression was conducted to determine associations between joint preparation, fixation techniques, postoperative immobilization, weightbearing, and pre- and postoperative HVA with nonunion.

RESULTS

Nonunion incidence was 15.2%, with 11.1% symptomatic and revised. Joint preparation using hand instruments (OR 3.75, CI 1.90-7.42) and convex/concave reamers (OR 2.80, CI 1.52-5.16) were associated with greater odds of a nonunion compared to planar cuts. Joint fixation with crossed screws was associated with greater odds of nonunion (OR 2.00, CI 1.11-3.42), as was greater preoperative HVA (OR 1.02, CI 1.00-1.03). However, the latter effect disappeared after inclusion of postoperative HVA in the model, with a small association identified between residual postoperative HVA and nonunion (OR 1.04, CI 1.01-1.08). Similarly, we found an association between odds of nonunion and higher body weight (OR 1.02, CI 1.01-1.04) but not of body mass index.

CONCLUSION

Based on our results, first metatarsophalangeal joint arthrodesis with planar cuts and fixation with a plate and interfragmentary screw is associated with the lowest odds of resulting in a nonunion. Higher body weight and greater preoperative HVA were associated with slight increase in rates of nonunion. It is crucial to properly correct the hallux valgus deformity during surgery.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Non-union incidence of different joint preparation types, joint fixation techniques, and postoperative weightbearing protocols for arthrodesis of the first metatarsophalangeal joint in moderate-to-severe hallux valgus: a systematic review

Purpose

A systematic review to determine the effect of different types of joint preparation, joint fixation, and postoperative weight-bearing protocols on non-union frequency in first metatarsophalangeal joint (MTPJ) arthrodesis in patients with moderate-to-severe hallux valgus.

Material and methods

A systematic literature search (PubMed and EMBASE), adhering to PRISMA guidelines. Data on MTPJ preparation, fixation, weight-bearing, and non-union in patients with moderate-to-severe hallux valgus were collected. Quality assessment was performed using the Coleman Methodology Score.

Results

Sixteen studies (934 feet) were included, generally of medium quality. Overall non-union rate was 7.7%. At 6.3%, convex/concave joint preparation had the lowest non-union rate vs 12.2% for hand instruments and 22.2% for planar cuts. Non-union of 2.8% was found for joint fixation with a plate combined with a lag screw vs 6.5% for plate fixation, 11.1% for crossed screw fixation, and 12.5% for a plate with a cross plate compression screw. A 5.1% non-union frequency was found following postoperative full weight-bearing on a flat shoe vs 9.3% for full weight-bearing on a heel weight-bearing shoe and 0% for a partial weight-bearing regimen.

Conclusion

Based on medium-quality papers, joint preparation with convex/concave reamers and joint fixation with a plate using a lag screw show the lowest non-union rate. Full postoperative weight-bearing in a stiff-soled postoperative shoe is safe and not associated with non-union vs a more protective load-bearing regimen. Further research should focus on larger sample sizes, longer follow-ups, and stronger study designs.

First Metatarsophalangeal Arthrodesis for the Failed Hallux

Hallux metatarsophalangeal joint (MTPJ) arthrodesis was first described in 1894 by Clutton, who recommended ankylosing the MTPJ to treat painful hallux valgus (HV). He used ivory pegs to stabilize the MTP joint. Surgeons over the last century have modified the procedure and added indications, including hallux rigidus, rheumatoid arthritis, and revision of failed surgeries. This article addresses many common yet challenging clinical scenarios, and a few hot topics, related to hallux MTPJ arthrodesis, including matarsus primus elevatus, severe hallux valgus, avascular necrosis, and infections. The article provides a condensed evidence-based discussion on how to manage these challenges using MTPJ arthrodesis.

Is the magnesium screw as stable as the titanium screw in the fixation of first metatarsal distal chevron osteotomy? A comparative biomechanical study on sawbones models

Background: Distal chevron osteotomy (DCO) is commonly performed in hallux valgus surgery. The fixation of the osteotomy is provided by various implants. The usage of biodegradable implants such as magnesium is gradually increasing due to the advantages they provide. In this study, we aimed to compare the fixation of DCO with magnesium or titanium screw biomechanically. Methods: Twenty sawbones were used. The samples were divided into two equal groups, including ten sawbones for fixation with single headless titanium (group-1) or magnesium screw (group-2). DCO and screw fixations were performed on all samples using the same technique. Biomechanical testing was applied to five samples in each group in cantilever and the other five in a physiological configuration using a computer connected to the electromechanical test machine. The obtained data were evaluated using the Shapiro-Wilk test, Student's t-test and Mann-Whitney U test on the IBM® SPSS (Statistical Package for the Social Sciences) V22.0 software. Significance was accepted at the p < 0.05 level. Results: There was no statistically significant difference between the magnesium screw and the titanium screw in terms of maximum force, maximum displacement and stiffness measurements in cantilever and physiological loadings (p > 0.05 for all). Conclusion: This study found no significant difference in biomechanical stability between the magnesium and titanium screws in DCO fixation on sawbones. Further studies with real bones are needed.

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.

Different fixation constructs and the risk of non-union following first metatarsophalangeal joint arthrodesis

BACKGROUND

The aim of this study was to determine if a single or separate construct with interfragmentary screw was associated with higher rates non-union following first metatarsophalangeal joint (MTPJ) arthrodesis.

METHODS

A retrospective analysis of patients undergoing first MTPJ arthrodesis between April 2010 and June 2017 was performed. Patients who received either a single (Stryker Anchorage 1 MTP Cross Plate) or separate (Stryker Anchorage 1 MTP locking plate with one Asnis partially threaded compression screw) construct locking plate and interfragmentary compression screw were reviewed. Descriptive statistics were generated for sample demographics and between-group differences were calculated. Multivariable regressions explored internal fixation type and association with non-union.

RESULTS

A total of 280 first MTPJ arthrodesis met the inclusion criteria and were reviewed. The incidence of non-union was 7.9% of procedures (22 joints). Following multivariable binary logistic regression, the single construct locking plate with interfragmentary compression screw was associated with an increased risk of non-union (OR 3.43, 95% CI 1.26-9.33), adjusting for age, gender and comorbidity.

CONCLUSIONS

A single construct interfragmentary screw and locking plate (Stryker Anchorage 1 MTP Cross Plate) was associated with an increased incidence of non-union following first MTPJ arthrodesis.

Severe Hallux Valgus Angle Attended With High Incidence of Nonunion in Arthrodesis of the First Metatarsophalangeal Joint: A Follow-Up Study

The incidence of nonunion after first metatarsophalangeal joint (MTP-1) arthrodesis was found to be high in our clinic. By raising awareness for the problem, making a uniform surgical treatment protocol, banning the commonly used convex-concave reamers, and promoting solely the use of hand instruments to prepare the joint for arthrodesis, we tried to decrease the numbers of nonunion. This prospective cohort study included all patients who underwent MTP-1 fusion between January 2018 and March 2019. Patients were treated according to a standardized protocol, using hand instruments to prepare the joint for fusion. Anthropometric and therapy-related data were collected and compared with an earlier 2015-2016 cohort that was retrospectively assessed. Furthermore, the frequency of nonunion between convex-concave reamers and hand instruments was compared. A total of 53 patients underwent MTP-1 fusion surgery. The incidence of nonunion was 3.8%, significantly lower than the 24.1% in 2015 to 2016 (p = .002). Multivariate regression analysis showed a 7.11 times higher risk of nonunion in 2015 to 2016 compared with 2018 to 2019 (95% confidence interval [CI] 1.55 to 32.55) (p = .012). Furthermore, an increase of 10° in HVA showed a 1.52 risk of occurrence of nonunion (95% CI 1.07 to 2.17) (p = .021). The use of convex/concave reamers was univariately associated with a 3.61 times higher risk of nonunion (95% CI 1.14 to 11.43) (p = .029); however, after correction for preoperative HVA, the preparation method was no longer associated with the occurrence of nonunion (p = .108). Patients suffering from severe hallux valgus had nonunion in 32.1% of cases. Incidence of nonunion after MTP-1 arthrodesis was significantly reduced by raising awareness and by standardizing the treatment protocol. There was no significant difference in nonunion frequency between the methods of joint surface preparation. Severe hallux valgus is prone to nonunion, and more research into this indication for MTP-1 fusion and outcome is needed.

Intrinsic Fixation of the Tibial Sesamoid in First Metatarsophalangeal Joint Arthrodesis: A Cadaveric Study

Nonunion rate of first metatarsophalangeal joint (MTP) joint arthrodesis is reportedly less than 6%, regardless of fixation type. Robust modern plating constructs aim to decrease incidence of nonunion while also allowing early postoperative weight-bearing. Quicker transition to weight-bearing postoperatively increases patient adherence, decreases adjacent joint stiffness, and reduces risk of deep vein thrombosis in the postoperative period. The purpose of this study was to investigate the effect tibial sesamoid fixation has on first MTP joint arthrodesis.

Complications after Metatarsal Osteotomies for Hallux Valgus: Malunion, Nonunion, Avascular Necrosis, and Metatarsophalangeal Osteoarthritis

Avascular necrosis (AVN), nonunion, malunion, and metatarsophalangeal (MTP) osteoarthritis following hallux valgus osteotomies, as well as pathophysiology, diagnosis, prevention strategies, and treatment are discussed in this article. AVN and nonunion are very infrequent, and they can be effectively prevented taking into consideration local anatomy preservation, biomechanics, and patient comorbidities. Shortening, elevation, plantarflexion, varus/valgus, and rotational of the first metatarsal are the most common types of malunion. They can lead to pain, stiffness, deformity recurrence, and transfer metatarsalgia. MTP osteoarthritis can develop after metatarsal malunion or AVN. Treatment options include cheilectomy, osteotomies to correct malunions, and MTP arthrodesis.

Management of high-grade hallux rigidus: a narrative review of the literature

Hallux rigidus is a disease characterized by an osteoarthritic degeneration of the first metatarsophalangeal joint. Aetiology of hallux rigidus is not clear in the literature. History of trauma is considered one of the most common causes of unilateral hallux rigidus. Also, repetitive microtraumas or inflammatory and metabolic causes such as gout, rheumatoid arthritis and seronegative arthropathy can cause degeneration of the joint. The aim of this literature narrative overview is to summarize and expose the great amount of management concepts and information, including the well-codified main operative procedures to treat of hallux rigidus. This may provide current information for med-school students, researchers and physicians. A comprehensive literature search using PubMed database has been performed. The management for hallux rigidus can involve a variety of therapeutic interventions, conservative or operative. High-grade hallux rigidus represents a complex disease characterized by several clinical and pathological findings, and to achieve optimal results, surgical treatment should be chosen between several surgical techniques depending on the degree of arthritis and other different clinical conditions.

Biomechanical Comparison of First Tarsometatarsal Arthrodesis Constructs Over Prolonged Cyclic Testing

Background:

Traditionally, a lengthy period of nonweightbearing is required following arthrodesis of the first tarsometatarsal (TMT) joint in order to provide a stable healing environment for the bones. The goal of this research was to determine the resistance to plantar gapping of 2 locked intramedullary devices and a medial plate with crossing screw, all specifically designed for hallux valgus correction, and compare them to traditional 2–crossing screw fixation under a cyclic testing protocol. We hypothesized the locked intramedullary devices and the medial plate with crossing screw would better resist plantar gapping.

Methods:

Forty cadaver specimens received 1 of 4 operative treatments: a locked intramedullary device with 2 points of fixation in the cuneiform, a locked intramedullary device with 1 point of fixation in the cuneiform, a medial plate with crossing screw, or 2 crossing screws. We applied dorsiflexion bending forces to the first TMT joint using a cadaveric fatigue model for 20 000 cycles. The plantar gap between the metatarsal and cuneiform was measured at the beginning and end of cyclic testing. Thirty-six specimens were included in the final data set.

Results:

Both locked intramedullary device groups and the medial plate with crossing screw group exhibited significantly less gap widening compared to the 2–crossing screw group (vs 3-hole intramedullary device, P = .014; vs 4-hole intramedullary device, P = .010; and vs medial plate with crossing screw, P = .044). The intramedullary device groups were the most stable during the cyclic fatigue test, exhibiting the smallest gap widening. The medial plate with crossing screw fixation was also more stable than crossing screws in the cyclic fatigue model.

Conclusions:

The locked intramedullary devices and medial plate with crossing screw resisted plantar gapping better than 2 crossing screws when used for first TMT arthrodesis.

Clinical Relevance:

These results indicate that locked intramedullary devices and medial plates with crossing screws may promote superior bone healing and may better tolerate early weightbearing compared with 2 crossing screws.

First Metatarsophalangeal Joint Arthrodesis Using an Intraosseous Post and Lag Screw With Immediate Bearing of Weight

Arthrodesis is the gold standard procedure for advanced arthrosis of the first metatarsophalangeal joint. Having a strong construct is preferable for allowing immediate bearing of weight, which facilitates patient rehabilitation. Plate and screw fixation is currently in favor but can lead to prominent metalware necessitating removal. The aim of this study is to report the results of a series of 54 first metatarsophalangeal joint arthrodeses performed in 52 patients treated with an implant composed of an intraosseous post and lag screw. All of the patients had a minimum follow-up of 1 year, and the indication for the surgery was end-stage hallux rigidus in 44 (81.5%) feet, severe hallux valgus in 8 (14.8%) feet, and rheumatoid arthritis in 2 (3.7%) feet. Arthrodesis was achieved in 52 (96.3%) feet at a mean of 61 ± 16 (range 39 to 201) days with nonunion observed in 2 (3.7%) feet; neither of the 2 patients had known risk factors. Metalware impinging on soft tissues necessitating removal was observed in 3 (5.6%) feet, and there were no cases of loss of position or implant breakage. The mean Manchester-Oxford Foot Questionnaire score improved from 46.4 ± 13.3 to 18.4 ± 9.4 (p < .001) at latest follow-up. In conclusion, our results suggest the intraosseous post and lag screw device was safe and effective, and it can be considered an alternative method of stabilizing the first metatarsophalangeal joint when undertaking arthrodesis surgery.

Clinical and Radiological Outcomes of Forefoot Offloading Versus Rigid Flat Shoes in Patients Undergoing Surgery of the First Ray

BACKGROUND

It is common clinical practice to use either flat or reverse camber shoes to protect the foot for up to 6 weeks after surgery for hallux valgus or hallux rigidus. To date there is a paucity of evidence as to whether there is any difference between these 2 postoperative shoes, in either patient satisfaction or clinical outcomes.

METHODS

One hundred consecutive patients undergoing scarf/Akin osteotomies or first metatarsophalangeal joint (MTPJ) arthrodesis were recruited. Patients were randomized 50:50 to either flat or reverse camber postoperative shoes. Patients undergoing ancillary lesser toe procedures were not excluded. Patient satisfaction was assessed by visual analog scale (VAS) pain score and Likert satisfaction survey. Radiographic outcomes were reviewed at 1 year observing differences in fusion rates or deformity recurrence. There were 47 patients in the reverse cam and 43 in the flat shoe group. No difference in primary forefoot operation, additional operation, age at surgery, or preop VAS pain score was seen.

RESULTS

At 6 weeks, there was no significant difference in postop VAS pain score. The flat shoe group was significantly more likely to be satisfied with their general mobility (86.0% vs 61.7%; P = .01) and with their stability in the shoe (90.7% vs 69.6%; P = .03). No significant difference was seen between groups for nonunion or hallux valgus recurrence rates.

CONCLUSION

Both forms of postoperative footwear were effective in enabling patients to mobilize and in preventing adverse outcomes. Patients were more likely to be satisfied with a flat postoperative shoe due to improved stability and ease of mobilizing. The results of this study aid surgeon decision making for postoperative footwear in forefoot surgery.

LEVEL OF EVIDENCE

Level II, prospective randomized controlled trial.

Biomechanical Comparison of Low-Profile Contoured Locking Plate With Single Compression Screw to Fully Threaded Compression Screws for First MTP Fusion

BACKGROUND

Open metatarsophalangeal (MTP) arthrodesis using locked plates produces good clinical outcomes. However, arthroscopic fusion with new-generation fully threaded compression screws is emerging as an alternative. The purpose of this study was to compare low-profile contoured locked plates with fully threaded compression screws for first MTP fusion, in a biomechanical cadaveric model.

METHODS

The first rays of 8 matched pairs of fresh frozen cadaveric feet underwent dissection and dual-energy x-ray absorptiometry (DEXA) scanning to measure bone mineral density (BMD). The "plate" group was prepared with cup-and-cone reamers, and fixation of the MTP joint with 1 compression screw and low-profile dorsal locked plate. The matched-pair "screws" group was prepared through a simulated arthroscopic technique, achieving fixation with 2 new-generation fully threaded compression screws. The plantar MTP gap was recorded with an extensometer during 250 000 90-N cyclic loads followed by a single load to failure.

RESULTS

The screw group demonstrated significantly greater stiffness, 31.6 N/mm (plates) and 51.7 N/mm (screws) (P = .0045). There was no significant difference in plantar gapping or load to failure, 198.6 N (plates) and 290.1 N (screws) (P = .2226). Stiffness and load to failure were highly correlated to BMD for the screw group, r =0.79 and r = 0.94, respectively, but less so for the plate group, r = 0.36 and r = 0.62, respectively. The maximum metatarsal head height measured on the lateral view was strongly correlated with load to failure for both the plate- and screw-only groups (r > 0.9).

CONCLUSION

These data demonstrate that hallux MTP arthrodesis utilizing fully threaded compression screws had similar plantar gapping and load to failure when compared with the low-profile locking plate, but with significantly more stiffness. These results support an increased role of fully threaded screws for MTP arthrodesis using either the arthroscopic or open technique. However, with decreased BMD plate fixation may remain the better fixation choice.

CLINICAL RELEVANCE

Our data suggest that with regard to construct stability, fully threaded headless compression screws may be just as effective as low-profile locking plates, but BMD and MTP joint fluoroscopic measurements should be considered in the decision-making process for fixation.

Allograft Tendon Interposition Arthroplasty of the Hallux Metatarsophalangeal Joint: A Technique Guide and Literature Review

The "anchovy" interpositional arthroplasty technique can be used as a salvage option for failed hallux rigidus procedures. The operative technique utilized by the senior author is described. Careful soft-tissue handling, meticulous joint space and graft preparation, and interposition graft stabilization using a bone tunnel and suture anchors are unique aspects of this technique, which in the authors' experience have contributed to improved outcomes. Current literature regarding indications and outcomes is limited and controversial. The proposed benefits of soft-tissue interposition arthroplasty of the hallux metatarsophalangeal joint for patients with prior failed implant arthroplasty are improved pain scores and preservation of range of motion. Level of Evidence: Level V, technique guide.

Long-Term Results of Hemiarthroplasty Compared With Arthrodesis for Osteoarthritis of the First Metatarsophalangeal Joint

If operative treatment is opted for grade 3 and 4 osteoarthritis of the first metatarsophalangeal joint, arthrodesis is considered the standard of care. However, if preservation of joint mobility is preferred, implant arthroplasty could be favored. Previous studies have suggested hemiarthroplasty might result in less pain, better function, and greater patient satisfaction compared with arthrodesis. However, these studies only evaluated short-term results (range 2.2 to 6.6 years). The aim of our study was to determine whether patients treated with hemiarthroplasty would show better postoperative outcomes compared with those treated with arthrodesis after ≥5 years after surgery. The American Orthopaedic Foot and Ankle Society hallux metatarsophalangeal interphalangeal (AOFAS-HMI) scale score was used as the primary outcome measure. Secondary outcomes addressed satisfaction rates, patient procedure recommendation, and number of unplanned repeat surgical procedures. We also addressed the influence of the procedures on daily activities (work and sports), the influence of smoking on the postoperative results, and the costs for both procedures. A total of 47 primary arthrodeses and 31 hemiarthroplasties performed between January 2005 and December 2011 were evaluated. After a mean follow-up period of 8.3 (range 5 to 11.8) years, the mean AOFAS-HMI scale score after arthrodesis and hemiarthroplasty was 72.8 ± 14.5 and 89.7 ± 6.6, respectively (p = .001). The patients were significantly more pleased after hemiarthroplasty (p < .001), and this procedure was recommended more often (p < .001). The number of unplanned repeat surgical procedures did not differ between the 2 groups. Patients resumed sports activities significantly sooner after hemiarthroplasty (p = .002). The overall crude costs were similar for both procedures. Our results have shown more favorable postoperative outcomes for hemiarthroplasty compared with arthrodesis as operative treatment of osteoarthritis of the first metatarsophalangeal joint after a mean follow-up period of 8.3 years.