Sonographic and MRI evaluation of the plantar plate: a prospective study

Ultrasonography-Based Quantitative Evaluation of Second Metatarsophalangeal Joint Instability in Female Patients With Hallux Valgus

BACKGROUND

Patients with moderate to severe hallux valgus (HV) sometimes exhibit second metatarsophalangeal (MTP) joint dislocation. Second MTP joint instability due to plantar plate (PP) injury has been suggested as one of the causes. However, there have been no reports that quantitatively evaluate this instability. This study aimed to evaluate second MTP joint instability in patients with HV without dislocation via ultrasonography and investigate its relationship with the presence of PP injury or foot form.

METHODS

Between May 2018 and July 2023, symptomatic female patients with HV without any lesser toe deformity were included in this study. Second MTP joint instability was defined as the dorsal displacement ratio (DDR) of the passively subluxated proximal phalangeal articular surface on the metatarsal head articular surface. The presence of PP injury was assessed using ultrasonography. Foot "form" was determined by measuring standard foot bony angles on weight-bearing foot-ankle radiographs. The relationship between DDR or PP injury and radiographic measurements was investigated.

RESULTS

Sixty-four patients (100 feet) were included. The average DDR of the second MTP joint in patients with HV without dislocation was 35.7%. There was an increase in the probability of PP injury, above a cutoff DDR value r of 35.4% (area under the curve = 0.712). The sensitivity, specificity, positive predictive value, and negative predictive value for the presence of PP injury based on this cutoff level were 63.9%, 74.4%, 79.6%, and 56.9%, respectively. Metatarsalgia was reported in 21 feet (21.0%), of which 15 feet (71.4%) showed PP injury. An increase in DDR was weakly associated with increased metatarsus adductus angle and decreased second metatarsal height.

CONCLUSION

In female patients with HV without second MTP dislocation, we found ultrasonographic evidence of second MTP plantar plate injury and joint instability to be a relatively common finding with a high prevalence in those with localized metatarsalgia.

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria based on consecutive patients.

Differential Diagnosis of Metatarsalgia

Lesser (or central) metatarsalgia is defined as pain in the forefoot under or around the lesser metatarsals and their respective metatarsophalangeal joints. Two common causes of central metatarsalgia are Morton's neuroma (MN) and plantar plate (PP) injury. Because both clinical and imaging features overlap, establishing the correct differential diagnosis may be challenging. Imaging has a pivotal role in the detection and characterization of metatarsalgia. Different radiologic modalities are available to assess the common causes of forefoot pain, so the strengths and weakness of these imaging tools should be kept in mind. It is crucial to be aware of the pitfalls that can be encountered in daily clinical practice when dealing with these disorders. This review describes two main causes of lesser metatarsalgia, MN and PP injury, and their differential diagnoses.

Particularities on Anatomy and Normal Postsurgical Appearances of the Ankle and Foot

The anatomy of the ankle and foot is complex, allowing for a wide range of functionality. The movements of the joints represent a complex dynamic interaction. A solid understanding of the characteristics and actions of the anatomic elements helps explain the mechanisms and patterns of injury. This article reviews the anatomy, with special focus on concepts that are the object of recent study and the features that favor the development of symptoms. Good understanding of the surgical procedures helps in providing information to guarantee a favorable outcome. We review the commonly expected postsurgical appearances and the most common postsurgical complications.

Presurgical Perspective and Postsurgical Evaluation of Plantar Plate and Turf Toe

Capsuloligamentous injury of the first metatarsophalangeal (MTP) joint (eponymously called "turf toe") mostly occurs in athletes and involves acute trauma, whereas tears of the lesser MTP joint plantar plate typically are an attritional-degenerative condition. This article reviews the anatomy, pathophysiology, mechanism and patterns of injury, grading and classification of injury, imaging appearances (pre- and postoperative), and management of first MTP joint capsuloligamentous injuries and lesser MTP joint plantar plate tears. These two distinct pathologies are discussed in separate sections.

The Utility of Ultrasound in the Evaluation of Traumatic Hallux Valgus

Isolated disruption of the medial collateral ligament of the great toe is rare and often misdiagnosed as turf toe. It may progress to acquired traumatic hallux valgus, often requiring operative intervention and a longer return to play. This case of a grade II medial collateral ligament injury highlights the importance of a thorough physical examination and consideration of the mechanism of injury. It demonstrates the utility of diagnostic musculoskeletal ultrasound in establishing a specific diagnosis upon initial patient presentation with great toe pain. It is an example of the use of ultrasound in guiding treatment and monitoring interval healing. In this case, differentiation of the injury from the classic "turf toe" led to proper stabilization with a toe spacer and activity modification, thus preventing progression of traumatic hallux valgus and leading to successful nonoperative treatment with full return to sport.

LEVEL OF EVIDENCE

Level V.

Incidental Finding of Plantar Plate Pathology on Routine Magnetic Resonance Imaging of the Foot and Ankle

BACKGROUND

We hypothesized that there would be a comparable and high incidence of an incidental torn plantar plate on routine magnetic resonance imaging (MRI) in asymptomatic patients.

METHODS

We included adult patients undergoing a foot MRI from 2019 to 2020. Based on the documented reason for MRI, patients were divided into symptomatic and asymptomatic. A separate musculoskeletal radiologist re-evaluated MRI images. Findings were categorized as "torn vs intact." We also used the anatomical grading system (AGS).

RESULTS

We reviewed 218 records, including 165 asymptomatic and 53 symptomatic patients. The chance of finding a plantar plate (PP) tear on MRI of symptomatic patients was 28% (21% in PP2, 5.7% in PP3, 5.7% in PP4, and 2% in PP5), while PP tear in asymptomatic patients was only apparent in 2% of MRIs (1.5% in PP2, 0 in PP3, 0 in PP4, and 0.6% in PP5). Cohen's kappa coefficient was 0.92, showing excellent agreement between the radiologists. Odds calculation revealed that the chance of finding a torn PP in an asymptomatic patient is 2.5%. In comparison, the chance of finding an intact PP in a symptomatic patient is 72%, showing 2.5 times more likely to find an intact PP than a torn PP in symptomatic individuals.

CONCLUSION

Interestingly, there was a low rate of abnormal PP appearance on MRI in both symptomatic and asymptomatic patients, which suggests that the chance of finding a false-positive PP tear in an asymptomatic patient is minimal and probably negligible.

LEVEL OF EVIDENCE

Level IV diagnostic.

Normal and Diseased Imaging: Ultrasound/MRI

The lesser metatarsophalangeal joint plantar plate and calcaneonavicular (spring) ligament are highly specialized soft tissue structures within the foot, consisting partly of fibrocartilage and capable of withstanding high compressive and tensile loads. Preoperative advanced imaging, in the form of point-of-care ultrasound and MRI, has become indispensable for surgeons hoping to confirm, quantify, and better localize injuries to these structures before surgery. This article describes the technical considerations of ultrasound and MRI and provides examples of the normal and abnormal appearances of these structures. The pros and cons of each imaging modality are also discussed.

Degenerative injuries of the metatarsophalangeal plantar plate on magnetic resonance imaging: a new perspective

Objective

The magnetic resonance imaging diagnostic criteria for a complete tear of metatarsophalangeal plantar plate are well-established. However, more subtle abnormalities can also occur and be a source of pain. The objective of this study is to determine the prevalence of degenerative plantar plate injuries in patients with metatarsalgia who underwent forefoot magnetic resonance imaging and describe the main abnormalities found. The hypothesis is that mild capsular fibrosis will have high sensitivity but low specificity for plantar plate degenerative injuries.

Methods

A retrospective cross-sectional study was conducted with 85 patients (105 feet) with metatarsalgia who underwent forefoot magnetic resonance imaging using a specific protocol to study metatarsophalangeal plantar plate. The experiment observer classified second toe plantar plate as normal, complete rupture or degenerative lesion and described the main magnetic resonance imaging findings.

Results

A normal plantar plate was observed in 75 (71.4%) of the 105 feet assessed, in 25 (24%) feet there were degenerative plantar lesions, and in 5 (4.6%) feet there were complete ruptures. Degenerative injury of the plantar plate was best identified in coronal short axis intermediate-weighted images, with high sensitivity (92%). Pericapsular fibrosis below the intermetatarsal ligament was identified in 96% of cases, with high sensitivity (96%) for diagnosis of degenerative plantar plate injury.

Conclusion

Degenerative lesions of the metatarsophalangeal plantar plate were more prevalent than complete ruptures and were best viewed in coronal short axis intermediate-weighted sequences. Pericapsular fibrosis below the intermetatarsal ligament was the indirect finding most strongly associated with degenerative plantar plate injury.

A problem-based approach in musculoskeletal ultrasonography: central metatarsalgia

Ultrasonography (US) is a useful diagnostic method that can be easily applied to identify the cause of metatarsalgia. The superficial location of structures in the foot, dynamic capability of US, and the ability to perform direct real-time evaluations of the pain site are also strong advantages of US as a modality for examining the foot. Moreover, knowing the possible pain sources to investigate when a patient has a specific site of pain will enhance the diagnostic quality of US, and will help radiologists to perform US efficiently and effectively. The purpose of this article is to review the common etiologies of metatarsalgia including Morton’s neuroma, plantar plate injury, synovitis, tenosynovitis, bursitis, and metatarsal fractures, and to discuss their US features.

Diagnostic Musculoskeletal Ultrasound for the Acute Evaluation and Management of Soccer Players

ABSTRACT

Musculoskeletal ultrasound (US) has many applications in the care of athletes. This article reviews the current literature and identifies research gaps regarding musculoskeletal US in the athletic training room setting to evaluate and manage soccer players. The best evidence for US in the training room setting is for diagnosis and prognosis of muscle injuries, where studies show that it is equivalent to other imaging modalities. US also has been used for injury risk prediction, although the data are mixed. Many applications of US are described in other sport settings and may have crossover applications to soccer.

Ultrasound findings of plantar plate tears of the lesser metatarsophalangeal joints

Lesser metatarsophalangeal (MTP) joint plantar plate tears are a common and increasingly recognised cause of metatarsalgia, MTP joint instability and forefoot deformity. Increased interest in early accurate diagnosis of plantar plate tears follows recent surgical innovations allowing direct plantar plate repair. The purpose of this review is to describe the ultrasound features of normal lesser MTP joint plantar plates and to characterise and illustrate the direct and indirect ultrasound findings of plantar plate tears. Lesser MTP joint plantar plate tears are most commonly located at the 2nd MTP joint, involving the lateral distal plantar plate insertion with variable propagation medially and proximally. The most common ultrasound appearance of a plantar plate tear is a discrete partial or full thickness hypoechoic defect in the plate substance. Flattening and attenuation or non-visualisation of the plantar plate represent more extensive tears. Dynamic imaging with toe dorsiflexion improves visualisation of tears and augments MTP joint subluxation. A common indirect finding is pericapsular fibrosis along the MTP joint capsule adjacent to a plantar plate tear, which requires differentiation from Morton's neuroma, and key distinguishing features at ultrasound are described. Other indirect findings include the cartilage interface sign, flexor tendon subluxation onto the metatarsal head or medial to the midline, flexor tenosynovitis, proximal phalangeal enthesophytes or avulsion and MTP joint synovitis. Ultrasound offers several advantages over MR imaging but requires a meticulous ultrasound examination, and optimisation of scanning technique is described.

ACR Appropriateness Criteria® Chronic Foot Pain

Chronic foot pain is a frequent clinical complaint, which can significantly impact the quality of live in some individuals. These guidelines define best practices with regards to requisition of imaging studies based on specific clinical scenarios, which have been grouped into different variants. Each variant is accompanied by a brief description of the usefulness, advantages, and limitations of different imaging modalities. The present narrative is the result of an exhaustive assessment of the available literature and a thorough review process by a panel of experts on Musculoskeletal Imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Acute Trauma to the Foot

Acute injuries to the foot are frequently encountered in the emergency room and in general practice settings. This publication defines best practices for imaging evaluations for several variants of patients presenting with acute foot trauma. The variants include scenarios when the Ottawa rules can be evaluated, when there are exclusionary criteria, and when suspected pathology is in anatomic areas not addressed by the Ottawa rules. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Plantar Plate Injury and Angular Toe Deformity

Lesser toe plantar plate injuries at the metatarsophalangeal (MTP) joint are a common source of metatarsalgia. The second MTP joint is the most commonly affected digit. The fibrocartilaginous plantar plate is the most important static stabilizer of the MTP joint; high loading with weight bearing can lead to attritional plantar plate injuries. Chronic pain with weight bearing is the common presentation of lesser toe instability. Untreated plantar plate instability can lead to hammer toe and mallet toe deformities. Combined Weil osteotomy and plantar plate repair yields favorable pain relief and angular deformity correction for patients who fail conservative treatment.

Musculoskeletal ultrasound: athletic injuries of the lower extremity

Athletic injuries of the lower extremities are commonly encountered in clinical practice. While some pathology can be diagnosed on physical exam, others are a clinical dilemma with nonspecific symptomatology. In these situations, ultrasound imaging can be utilized as an exceptional diagnostic tool, offering unique advantages over other imaging modalities. This article will review the imaging characteristics of commonly encountered athletic injuries of the lower extremity.

Lesser Metatarsophalangeal Joint Instability: Advancements in Plantar Plate Reconstruction

The plantar plate and associated collateral ligaments are the main stabilizers of each of the lesser metatarsophalangeal joints. Although clinical examination and plain radiographs are usually sufficient to establish the diagnosis of a plantar plate tear, MRI or fluoroscopic arthrograms may help in specific cases. Recent results with a dorsal approach to plantar plate repair are promising with respect to pain relief and patient satisfaction.

Plantar plate pathology is associated with erosive disease in the painful forefoot of patients with rheumatoid arthritis

Background

Disease-related foot pathology is recognised to have a significant impact on mobility and functional capacity in the majority of patients with rheumatoid arthritis (RA). The forefoot is widely affected and the metatarsophalangeal (MTP) joints are the most common site of symptoms. The plantar plates are the fibrocartilaginous distal attachments of the plantar fascia inserting into the five proximal phalanges. Together with the transverse metatarsal ligament they prevent splaying of the forefoot and subluxation of the MTP joints. Damage to the plantar plates is a plausible mechanism therefore, through which the forefoot presentation, commonly described as ‘walking on pebbles’, may develop in patients with RA.

The aims of this study were to investigate the relationship between plantar plate pathology and clinical, biomechanical and plain radiography findings in the painful forefoot of patients with RA. Secondly, to compare plantar plate pathology at the symptomatic lesser (2nd-5th) MTP joints in patients with RA, with a group of healthy age and gender matched control subjects without foot pain.

Methods

In 41 patients with RA and ten control subjects the forefoot was imaged using 3T MRI. Intermediate weighted fat-suppressed sagittal and short axis sequences were acquired through the lesser MTP joints. Images were read prospectively by two radiologists and consensus reached. Plantar plate pathology in patients with RA was compared with control subjects. Multivariable multilevel modelling was used to assess the association between plantar plate pathology and the clinical, biomechanical and plain radiography findings.

Results

There were significant differences between control subjects and patients with RA in the presence of plantar plate pathology at the lesser MTP joints. No substantive or statistically significant associations were found between plantar plate pathology and clinical and biomechanical findings. The presence of plantar plate pathology was independently associated with an increase in the odds of erosion (OR = 52.50 [8.38–326.97], p < 0.001).

Conclusion

The distribution of plantar plate pathology at the lesser MTP joints in healthy control subjects differs to that seen in patients with RA who have the consequence of inflammatory disease in the forefoot. Longitudinal follow-up is required to determine the mechanism and presentation of plantar plate pathology in the painful forefoot of patients with RA.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1668-0) contains supplementary material, which is available to authorized users.

Accuracy of Sonography in Plantar Plate Tears in Cadavers

OBJECTIVES

Sonography is often used in the evaluation of forefoot disorders, and its use has been suggested in the diagnosis of plantar plate tears. This study aimed to assess the accuracy of sonography in the diagnosis of plantar plate tears of the lesser digits using gross dissection as the reference standard.

METHODS

The second through fifth digits of 6 cadavers were examined with sonography to evaluate for plantar plate tears. The examination was performed by a single musculoskeletal radiologist in longitudinal and short axes, and plates were graded as torn or intact. The digits were then dissected by a single podiatrist blinded to the prior sonographic results to assess the integrity of the plates.

RESULTS

Ten plantar plates were graded as torn by sonography, all occurring in the distal plate near the phalangeal insertion. Seven of these plates were identified as torn on direct inspection. Fourteen plantar plates were found to be intact on sonography, 12 of which were intact on gross inspection. Overall, the accuracy, sensitivity, and specificity of sonography were 79.2%, 77.8%, and 80.0%, respectively. No correlation was seen between the accuracy of sonography and plate size, using plate number as a surrogate marker for plate size (P = .822).

CONCLUSIONS

Sonography is an appropriate modality in the setting of suspected plantar plate tears, with acceptable accuracy, sensitivity, and specificity. No decline in accuracy was seen with smaller plates. Thus, sonography may be especially useful when small anatomy or technical factors make magnetic resonance imaging challenging to perform and interpret.

Comparing Magnetic Resonance Imaging and High-Resolution Dynamic Ultrasonography for Diagnosis of Plantar Plate Pathology: A Case Series

Plantar plate pathology has gained noticeable attention in recent years as an etiology of lesser metatarsophalangeal joint pain. The heightened clinical awareness has led to the need for more effective diagnostic imaging accuracy. Numerous reports have established the accuracy of both magnetic resonance imaging and ultrasonography for the diagnosis of plantar plate pathology. However, no conclusions have been made regarding which is the superior imaging modality. The present study reports a case series directly comparing high-resolution dynamic ultrasonography and magnetic resonance imaging. A multicenter retrospective comparison of magnetic resonance imaging versus high-resolution dynamic ultrasonography to evaluate plantar plate pathology with surgical confirmation was conducted. The sensitivity, specificity, and positive and negative predictive values for magnetic resonance imaging were 60%, 100%, 100%, and 33%, respectively. The overall diagnostic accuracy compared with the intraoperative findings was 66%. The sensitivity, specificity, and positive and negative predictive values for high-resolution dynamic ultrasound imaging were 100%, 100%, 100%, and 100%, respectively. The overall diagnostic accuracy compared with the intraoperative findings was 100%. The p value using Fisher's exact test for magnetic resonance imaging and high-resolution dynamic ultrasonography was p = .45, a difference that was not statistically significant. High-resolution dynamic ultrasonography had greater accuracy than magnetic resonance imaging in diagnosing lesser metatarsophalangeal joint plantar plate pathology, although the difference was not statistically significant. The present case series suggests that high-resolution dynamic ultrasonography can be considered an equally accurate imaging modality for plantar plate pathology at a potential cost savings compared with magnetic resonance imaging. Therefore, high-resolution dynamic ultrasonography warrants further investigation in a prospective study.

Role of magnetic resonance imaging versus ultrasound for detection of plantar plate tear

BACKGROUND

Plantar plate tears could be the reason of forefoot pain, affecting foot function. Magnetic resonance imaging (MRI) and ultrasound (US) were commonly used for the diagnosis of plantar plate tears. The decision of whether to use MRI or US carried some controversy. Our study aimed to find out the diagnostic accuracy of MRI versus US for plantar plate tears.

METHODS

The database of the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, and relative orthopedic meetings until May 2016 were searched. Studies involved in the diagnostic detection of MRI or ultrasound for plantar plate tears with surgical criteria as the reference test were included. Data was analyzed by meta-analysis. We compared sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and summary receiver operating characteristic (sROC) plot of both MRI and US.

RESULTS

Seven studies involving 246 plantar plate tears were included. The MRI showed more diagnostic accuracy than US for the detection of plantar plate tears. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of MRI were 95%, 54%, 2.08, and 0.08, respectively, while the same values for US were 93%, 33%, 1.20, and 0.35, respectively. And the sROC showed more superior diagnostic accuracy than the US.

CONCLUSION

The current result suggests that MRI has better accuracy than US for detection of plantar plate tears.

Evaluation of lesser metatarsophalangeal joint plantar plate tears with contrast-enhanced and fat-suppressed MRI

OBJECTIVE

To present findings of plantar plate (PP) lesions from MRI with administration of gadolinium and to differentiate PP lesions from others causes of metatarsalgia.

MATERIALS AND METHODS

Two musculoskeletal radiologists reviewed 249 contrast-enhanced forefoot MRI scans from patients with metatarsalgia between June 2012 and June 2013. Evaluations focused on hyper-vascularized/fibrous tissue and other findings associated with PP tears.

RESULTS

Fifty-nine patients had PP tears, 59 % were female. Most of these patients, 48/59 (81.4 %), had a single metatarsophalangeal (MTP) PP lesion in one foot, although 7/59 patients had one lesion in each foot, 3/59 (5.1 %) had two in one foot, and 1/59 (1.7 %) had three lesions in one foot. The second MTP joint was the most common location for PP tears (n = 56), followed by the third (n = 12) and fourth (n = 3) MTP joints. Lateral (n = 33) and full thickness (n = 28) PP lesions were the most frequent, and central (n = 3) and lateral/central (n = 7) tears were less prevalent. Fifty (70.5 %) PP lesions showed pericapsular fibrosis in pre-contrast sequences, and 21 (29.5 %) were visible only after administration of gadolinium. All PP lesions had collateral ligament involvement. Others findings included interosseous tendon lesions (n = 29), interosseous tendon rupture (n = 29), synovitis (n = 49), flexor tenosynovitis (n = 28), crossover toe (n = 2), hammertoe (n = 1), intermetatarsal space (IS) neuromas (n = 11), and third IS neuromas (n = 12).

CONCLUSION

PP tears are a common cause of metatarsalgia, accounting for more than 20 % of cases in our sample. A substantial portion of the lesions (29.5 %) became visible only after the administration of gadolinium.

Conservative Management of Second Metatarsophalangeal Joint Instability in a Professional Dancer: A Case Report

STUDY DESIGN

Case report.

BACKGROUND

Professional ballet and modern dancers spend an inordinate amount of time on demi pointe (rising onto their forefeet), placing excessive force on the metatarsophalangeal joints and putting them at risk of instability. Surgical treatment of this condition is well described in the literature. However, studies describing conservative management, particularly in dance populations, are lacking.

CASE DESCRIPTION

A 33-year-old dancer presented with insidious onset of medial arch and second and third metatarsophalangeal joint pain. Functional deficits included the inability to walk barefoot, perform demi relevé, or balance on demi pointe. Imaging studies revealed osteoarthritis of the first metatarsophalangeal joint, second metatarsophalangeal joint calcification, capsulitis, and plantar plate rupture, leading to a diagnosis of instability. The dancer underwent a treatment program that included taping, padding, physical therapy, a series of prolotherapy injections, and activity modification.

OUTCOMES

The dancer was seen for a total of 37 physical therapy sessions over the 16-week rehabilitation period. At the time of discharge, the patient had returned to full duty and performed all choreography with taping and padding. Repeated single-leg jumps and turns on the right foot, however, still caused discomfort. At her 6-month follow-up, the dancer's total Dance Functional Outcome Survey (DFOS) score had improved from 16% to 86%, and her Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) physical scores improved from 24 to 47. One year after discharge, the dancer reported pain-free dancing with no taping or padding.

DISCUSSION

This case report describes early diagnosis and a multimodal treatment approach in a professional dancer with significant disability secondary to metatarsophalangeal joint instability.

LEVEL OF EVIDENCE

Therapy, level 4.

Tendon Transfers for Management of Digital and Lesser Metatarsophalangeal Joint Deformities

Managing digital and metatarsophalangeal joint (MTPJ) deformities can range from simple to complex and uniplanar to triplanar. Because of the complexity and variability of digital and MTPJ deformities, there are many procedures, and no 1 procedure has become the gold standard. Tendon transfers for digital and MTPJ deformities are just 1 treatment option, and usually they are not stand-alone procedures. Typically, a combination of procedures needs to be performed. This article describes the surgical technique and provides a review of the literature, including clinical results for tendon transfers of the central rays.

The accuracy of diagnostic ultrasound imaging for musculoskeletal soft tissue pathology of the extremities: a comprehensive review of the literature

Musculoskeletal diagnostic ultrasound imaging (MSK-DUSI) has been growing outside the traditional radiology speciality. Increased use of this technology has been reported in several healthcare settings, however an apparent gap in the knowledge of the accuracy of this diagnostic technology indicated a review was warranted. We undertook a structured review of the literature to assess the accuracy of MSK-DUSI for the diagnosis of musculoskeletal soft tissue pathology of the extremities. An electronic search of the National Library of Medicine’s PubMed database (1972 to mid-2014) was conducted. All relevant systematic reviews of diagnostic studies, all diagnostic studies published after the date of the latest systematic reviews and relevant diagnostic studies outside the scope the systematic reviews that directly compared the accuracy of MSK-DUSI (the index test) to an appropriate reference standard for the target condition were included. A fundamental appraisal of the methodological quality of studies was completed. The individual sensitivity, specificity and likelihood ratio data were extracted and entered into diagnostic accuracy tables. A total of 207 individual studies were included. The results show that MSK-DUSI has acceptable diagnostic accuracy for a wide spectrum of musculoskeletal conditions of the extremities. However, there is a lack of high quality prospective experimental studies in this area and as such clinicians should interpret the results with some caution due to the potential for overestimation of diagnostic accuracy.

Can ultrasound of plantar plate have normal appearance with a positive drawer test?

OBJECTIVES

The aims of this study were (1) to evaluate the reliability of ultrasound (US) examination in the identification and measurement of the metatarsophalangeal plantar plate (MTP-PP) in asymptomatic subjects and (2) to establish the correlation of US findings with those of physical examination and magnetic resonance imaging (MRI), once it is an important tool in the evaluation of the instability syndrome of the second and third rays.

MATERIALS AND METHODS

US examinations of the second and third MTP-PPs were performed in eight asymptomatic volunteers, totaling 32 MTP joints, by three examiners with different levels of experience in musculoskeletal US. Plantar plate dimensions, integrity and echogenicity, the presence of ruptures, and confidence level in terms of structure identification were determined using conventional US. Vascular flow was assessed using power Doppler. US data were correlated with data from physical examination and MRI.

RESULTS

MTP-PPs were ultrasonographically identified in 100% of cases, always showing homogeneous hyperechoic features and no detectable vascular flow on power Doppler, with 100% certainty in identification for all examiners. There was excellent US inter-observer agreement for longitudinal measures of second and third toe MTP-PPs and for transverse measures of the second toe MTP-PP. The MTP drawer test was positive for grade 1 MTP instability in 34.4% of joints with normal US results. Transverse MTP-PP measures were significantly higher in individuals with positive MTP drawer test. US measures and characteristics of MPT-PPs were positively correlated with those of MRI.

CONCLUSIONS

US is efficient in identifying and measuring MPT-PPs and may complement physical examination. A grade 1 positive MTP drawer test may be found in asymptomatic individuals with normal MPT-PPs, as assessed by imaging.

Positive drawer test combined with radiographic deviation of the third metatarsophalangeal joint suggests high grade tear of the second metatarsophalangeal joint plantar plate

There is uncertainty regarding the most accurate and cost-effective method for diagnosing plantar plate injuries within the foot. The purpose of this study was to examine the combined value of using clinical and radiographic findings to diagnose high grade tears (> 50% disruption) within the second metatarsophalangeal (MTP) joint. Ninety-eight consecutive patients (117 feet) who underwent corrective surgery for plantar forefoot pain at a single foot and ankle specialty clinic were included in this retrospective analysis. All patients received a structured intraoperative assessment of the second MTP joint plantar plate by a single trained observer. Twenty-five clinical and plain film radiographic variables obtained prior to surgery were tested for their association with a high grade plantar plate tear using multiple logistic regression techniques. A positive drawer sign was the most informative individual test for differentiating high from low grade tears (odds ratio [OR] = 2.9; 95% confidence interval [CI], 0.92-9.5; sensitivity 91.5%; specificity 22%). Patients with longstanding forefoot symptoms (> 2 years) tended to be more likely to have low grade tears only (OR = 2.1; 95% CI, 0.98-4.5; sensitivity 61.7%; specificity 58.1%). Most radiographic measurements did little to distinguish high from low grade tears; however, the addition of ipsilateral third MTP joint transverse deviation angle showed a trend toward improving upon the diagnostic accuracy of strategies that used clinical findings alone (area under the curve [AUC] improved from 0.63 to 0.67; P = .11). A third MTP joint deviation angle greater than 15° in either direction combined with drawer testing and duration of symptoms achieved the highest specificities of any combination of variables examined in the study (specificities 82.4% [95% CI, 73.7%-91.1%] and 89.1 [95% CI, 82.1-96.3], respectively). The combination of a positive drawer test coupled with transverse deviation of the third MTP joint (> 15°) on plain films strongly suggests an underlying high grade plantar plate tear of the second MTP joint. However, this study highlights the need for using advanced imaging to distinguish between high and low grade tears in many instances (eg, positive drawer test and normal or near-normal alignment of the third MTP joint).

LEVEL OF EVIDENCE

Diagnostic, Level II.

MRI of lesser metatarsophalangeal joint plantar plate tears and associated adjacent interspace lesions

OBJECTIVE

To identify the variety of second and third intermetatarsal space (IS) lesions that may coexist with and without adjacent metatarsophalangeal joint (MTP) plantar plate (PP) tears.

MATERIALS AND METHODS

One hundred forefoot MRIs in 96 patients with metatarsalgia obtained between 30 September 2011 and 21 July 2012 using 1.5- or 3-T MRI were retrospectively reviewed in consensus by two MSK radiologists and one podiatrist (DPM). MRI was evaluated for second and third MTP PP tear and the presence/nature of second and third IS lesions. Second and third IS neuromas were measured in transverse (trans) dimension.

RESULTS

A total of 40 PP tears were identified: 36 at the second and 4 at the third MTP. Second MTP PP tear was identified in 33% of females and 40.5% of males. In the 63 female feet there were 21 second MTP PP tears, all of which also had second IS lesions: pericapsular fibrosis (16), bursitis (4), and ganglion (1). In the 37 male feet there were 15 second MTP PP tears, 14 of which had second IS lesions: pericapsular fibrosis (8), bursitis (5), and ganglion (1). There was no definite second IS neuroma adjacent to any second MTP PP tear. In females without PP tear, there were 24 second (3 mm trans average) and 43 third IS neuromas (4.1 mm trans average). In males without PP tear, there were 9 second (3.4 mm trans average) and 16 third IS neuromas (4.1 mm trans average).

CONCLUSIONS

MTP PP tears occurred in 40% of our cases, 90% of which occurred at the second MTP. Almost all coexisted with non-neuromatous second IS lesions.

Static Versus Dynamic Musculoskeletal Ultrasound for Detection of Plantar Plate Pathology

Musculoskeletal ultrasound (US) is a common modality used to examine plantar plate pathology. Comparison of the diagnostic accuracy of static versus dynamic ultrasound has not been previously published. The objective of this study was to prospectively compare the value of using preoperative static and dynamic ultrasound findings to diagnose plantar plate pathology using intraoperative inspection as the standard of reference. Patients attending a single foot and ankle specialty clinic from August 2012 to June 2013 with clinically suspected plantar plate pathology that was unresponsive to conservative care served as the study population. Static and dynamic ultrasound exams were performed by a single experienced rater and compared to intraoperative findings. The overall accuracy, sensitivity, specificity, positive predictive value and negative predictive value were determined for static and dynamic ultrasound exams. Thirty-six patients (45 lesser metatarsophalangeal joints) were included in this analysis. Of the 36 patients, 29 were females and 7 were males with average age of 57.9 ± 7.8 years (range, 38-73). There were 38 plantar plate tears (84.4%) noted on intraoperative examination. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for the static US exam were 80.0%, 81.6%, 71.4%, 93.9%, and 41.7%, respectively. The same values for the dynamic US exam were 88.9%, 100%, 28.6%, 88.3%, and 100%, respectively. Static and dynamic ultrasound techniques are each highly sensitive methods for assessing plantar plate pathology. However, the sensitivity and accuracy of the exam is best when dynamic assessment of the plantar plate is employed. Caution should be used when relying solely on static images to diagnose subtle injuries in this area of the foot.

LEVELS OF EVIDENCE

Diagnostic Level II, Prospective.

The plantar plate of the first metatarsophalangeal joint: an anatomical study

The plantar plate of the first metatarsophalangeal (MP) joint is a critical structure of the forefoot that has been identified as a major stabilizer within the capsuloligamentous complex. Many studies have clarified and documented the anatomy of the lesser toe MP plantar plates, but few have looked closely at the anatomy of the first MP joint. Ten cadaveric specimens were examined to identify and document the objective anatomic relationship of the plantar plate, tibial sesamoid, and surrounding osseus structures. The average distance of the plantar plate distal insertion from the joint line into the proximal phalanx was 0.33 mm. The plantar plate was inserted into the metatarsal head on average 17.29 mm proximal from the joint line. The proximal aspect of the sesamoid was 18.55 mm proximal to the distal attachment of the plantar plate to the phalanx. The distal aspect of the sesamoid averaged 4.69 mm away from the distal attachment into the proximal phalanx. The footprint of the distal plate insertion was on average 6.33 mm in length in the sagittal plane. The authors hope that these objective data measures can aid in the understanding and subsequent surgical repair of this important forefoot structure.

Practical US of the forefoot

Disorders affecting the forefoot are common in the clinical practice. Accurate history and physical examination are the mainstays of diagnosis but imaging modalities are frequently obtained to confirm the clinical suspicion and plan appropriate treatment. In this article we will present the ultrasound (US) technique of examination of the forefoot followed by a brief description of the normal US anatomy and of US appearance of the most frequent forefoot disorders; rheumatoid arthritis, osteoarthritis, overuse arthropathy, Morton neuromas, bursitis, mucoid cysts, foreign bodies, bone disorders.

Forefoot: a basic integrated imaging perspective for radiologists

Imaging of the forefoot is increasingly requested for patients with metatarsalgia. Awareness with specific anatomic arrangements exclusive for the forefoot and widely variable pathologic entities associated with metatarsalgia helps the radiologist to tailor a cost-effective imaging approach. This will enable reaching a specific diagnosis as much as possible with subsequent proper patient management. This pictorial review aims to provide basic understanding for the different imaging modalities used in studying the forefoot. After that, certain anatomic arrangements exclusive for the forefoot are discussed. The final section of this review describes the imaging findings of some common forefoot problems.

Ultrasound imaging for diagnosis of plantar plate ruptures of the lesser metatarsophalangeal joints: a retrospective case series

Tears of the plantar plate can be a source of significant forefoot pain, leading to alterations of foot function and gait. The objective of the present retrospective study was to further determine the value of ultrasound imaging in diagnosing plantar plate tears after clinical evaluation through a comparison of the ultrasound and intraoperative examination findings. Eight patients were identified who had undergone surgical intervention for a painful lesser metatarsophalangeal joint after ultrasound examination to diagnose a plantar plate pathologic entity. The intraoperative examination findings were used to calculate the sensitivity, specificity, and positive and negative predictive values of ultrasound in the diagnosis of plantar plate tears. The sensitivity and specificity of the ultrasound examination was 1 and 0.6, respectively. The positive and negative predictive value was 0.6 and 1, respectively. An ultrasound examination in the diagnosis of lesser metatarsophalangeal joint plantar plate tears displayed comparable sensitivity in identifying the pathologic features when compared with magnetic resonance imaging, with considerably less financial cost for the examination.

Musculoskeletal ultrasound for preoperative imaging of the plantar plate: a prospective analysis

The purpose of this study was to prospectively compare preoperative findings on musculoskeletal ultrasound evaluation to observed intraoperative findings for patients undergoing surgical correction of plantar plate tears. Fifty consecutive patients with forefoot pain and a suspected unilateral plantar plate tear at the second metatarsophalangeal (MTP) joint were identified. The same examiner performed a 2-plane (longitudinal and transverse) musculoskeletal ultrasound on the painful second MTP joint. The contralateral second MTP joint was used for comparison. Longitudinal ultrasound images were graded as "torn" or "intact." Transverse ultrasound images were used to localize the suspected pathology. Results of the ultrasound were compared with observed intraoperative pathology. Forty-five plantar plate tears were identified intraoperatively. Longitudinal ultrasound images correctly identified 40 plantar plate tears. The longitudinal ultrasound had a sensitivity of 91.1%, a specificity of 25%, a positive predictive value of 91.1%, and a negative predictive value of 25%. Transverse ultrasound images identified 36 plantar plate tears correctly localizing only 19 tears. Musculoskeletal ultrasound has been widely used to identify and localize pathology in many soft tissue structures. Whereas the longitudinal ultrasound images were useful in identifying plantar plate tears, the same cannot be said about the ability to localize the tear on the transverse ultrasound images. Therefore, ultrasound may not be as good an imaging modality as magnetic resonance imaging for identification and localization of plantar plate pathology.

The underlying osseous deformity in plantar plate tears: a radiographic analysis

PURPOSE

Plantar plate tears can cause pain and deformity of the forefoot. The purpose of this study is to correlate common radiographic findings with observed intra-operative pathology in patients with plantar plate pathology.

METHODS

Bilateral weight-bearing radiographs were reviewed for 88 patients (106 feet) who underwent surgical repair of suspected plantar plate pathology. Parameters reviewed included the first intermetatarsal angle, the metatarsus adductus angle, the second and third metatarsophalangeal angles, splaying of the second and third toes, evaluation of the metatarsal parabola by 3 different methods, the first and second lateral declination angles, and the second lateral metatarsophalangeal angle.

RESULTS

Of 106 feet, 97 had intra-operative plantar plate tears. The radiographs of patients with plantar plate tears had an increased amount of digital splay on the anteroposterior radiograph compared to patients without pathology. For patients with unilateral plantar plate pathology, the metatarsal parabola of the symptomatic foot was compared with that of the asymptomatic foot. A significantly increased second metatarsal protrusion distance as measured by 2 different methods was noted in the symptomatic foot. Odds ratios revealed that patients with an intermetatarsal angle >12, medial deviation of the second toe, and splaying of the digits were more likely to be diagnosed with a plantar plate tear intra-operatively.

CONCLUSION

Although radiographs do not definitively diagnose plantar plate tears, understanding osseous forefoot architecture will aid with diagnosis in the absence of other osseous pathology. Furthermore, these data suggest that parabola should be corrected to maintain long-term correction of plantar plate pathology.

LEVEL OF EVIDENCE

Prognostic, Level II.

MRI evaluation of the MTP plantar plates compared with arthroscopic findings: a prospective study

BACKGROUND

Instability of the lesser metatarsophalangeal (MTP) joints has been widely reported and plantar plate insufficiency is a key part of this pathologic process. The diagnosis is made clinically but can be aided by imaging studies, particularly magnetic resonance imaging (MRI); however, the sensitivity and accuracy of this method compared to direct visualization of these lesions has not yet been established, nor has interobserver accuracy of MRI been assessed for evaluation of plantar plate pathology. In this study, our goals were to identify the accuracy of the MRI in describing plantar plate tears when compared to direct arthroscopic visualization using an anatomic grading system and to test the influence of an anatomic grading system in the accuracy of the MRI readings.

METHODS

We evaluated the clinical exam, MRI scans, and arthroscopic findings of 35 patients with lesser MTP instability.

RESULTS

Using an anatomic grading system, a distinct improvement in the radiological evaluation and interpretation occurred. Knowledge of the pattern of plantar plate tears by a radiologist enabled them to locate and describe the type of tears of the plantar plate on the MRI. The amount of training and the experience of the radiologist were also important factors in our study. The senior radiologists had much better levels of accuracy (Group A, 77.0%; Group B, 88.5%) than less experienced radiologists.

CONCLUSION

Prior knowledge of the pathophysiology and morphological types of lesions of the plantar plates was helpful for accurate identification and description of the tears by the radiologist.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Magnetic resonance imaging versus musculoskeletal ultrasound for identification and localization of plantar plate tears

PURPOSE

Plantar plate injuries have been identified as a cause of forefoot pain and deformity. Magnetic resonance imaging (MRI) and musculoskeletal ultrasound (US) have been suggested as appropriate imaging modalities for this pathology. A comparison of these two modalities utilizing intra-operatively pathology as the reference standard has not been published.

METHODOLOGY

51 feet of 42 consecutive patients presenting to clinic with forefoot pain and a suspected unilateral plantar plate tear at the 2nd metatarsophalangeal (MTP) joint were identified. A two plane (longitudinal and transverse) US was performed on the painful second MTP joint. Longitudinal ultrasound images were graded as 'torn' or 'intact'. Transverse ultrasound images were used to localize pathology. All ultrasound exams were performed by the same reconstructive foot & ankle fellow. A pre-operative MRI was performed on these patients and read by a Fellowship Trained Musculoskeletal Radiologist. The physicians reading US and the MRI were blinded to each other's findings.

RESULTS

All 51 feet were examined intra-operatively. 46 plantar plate tears were identified. The sensitivity, specificity, positive predictive value and negative value of MRI were 73.9%, 100%, 100%, 29.4% respectively while the same values for US were 91.5%, 25%, 91.5%, 25% respectively. MRI identified 4 collateral ligaments tears not identified on ultrasound. Discussion &

CONCLUSIONS

Both MRI and US are appropriate modalities for imaging of the plantar plate. While US is a highly sensitive exam, MRI is a more specific exam. Overall these results do not suggest that MR should be replaced by US in all cases.

LEVEL OF EVIDENCE

Diagnostic, Level I.

Role of collateral ligaments in metatarsophalangeal stability: a cadaver study

BACKGROUND

Lesser metatarsophalangeal joint (MTPJ) instability is a common complaint. The role each of the collateral structures play in maintaining joint stability is unknown.

METHODS

Twenty-six fresh-frozen cadaver lesser MTPJ's were tested for instability with the amount of force necessary to translate the joint 3 mm dorsally. Specimens were tested with 1) intact collateral ligaments, 2) transected accessory collateral or proper collateral ligaments (ACL or PCL), 3) repaired ACL or PCL, 4) transected ACL and PCL, 5) repaired ACL and PCL, and 6) transferred interosseous (IO) tendon. Student t-tests were performed to test for statistical significance (p value less than 0.05).

RESULTS

The mean force required for 3 mm of dorsal displacement was 25 ± 13 N (range, 11 to 52 N) in the 26 specimens. Transecting either the ACL alone or the ACL and PCL led to the most instability versus transecting the PCL alone. Repairing both ligaments improved stability. The IO tendon transfer was comparable to the direct repair of the PCL but was inferior to the direct repair of the ACL.

CONCLUSION

Both ACL and PCL have a stabilizing effect on the MTPJ. However, the ACL was more important since primary transection of the ACL led to more instability and additional transection of the PCL in an ACL deficient model did not lead to significantly more instability.

CLINICAL RELEVANCE

Direct repairs of both structures improved the stability of the joint but not back to normal. IO tendon transfer is a possible adjunct to collateral ligament repairs, but in itself is not sufficient to restore stability.

Magnetic resonance arthrography of lesser metatarsophalangeal joints in patients with rheumatoid arthritis: relationship to clinical, biomechanical, and radiographic variables

OBJECTIVE

Our exploratory study of painful lesser metatarsophalangeal (MTP) joints in patients with rheumatoid arthritis (RA) primarily aimed to compare the clinical, biomechanical, and plain radiography findings with magnetic resonance (MR) arthrography findings. Our secondary aim was to compare standard unenhanced MR with MR arthrography in imaging the lesser MTP joints in RA.

METHODS

In 15 patients with RA, the more symptomatic forefoot was imaged using 3T MR imaging. Proton density fat-suppressed images were acquired through the lesser MTP joints prior to arthrography. Under ultrasound guidance, contrast agent was injected into 2 lesser MTP joints. T1-weighted fat-suppressed sequences were subsequently acquired. The MR images were read by 2 musculoskeletal radiologists and consensus was reached. Spearman's correlation coefficient was used to assess the association between abnormalities seen on MR arthrography and the clinical, biomechanical, and plain radiography findings.

RESULTS

MR arthrography demonstrated pathology at 18 of 28 lesser MTP joints (64%) examined in patients with RA. MR arthrography abnormalities were associated with RA disease duration, forefoot deformity, Larsen score, subluxation, and peak plantar pressure. Unenhanced MR had a sensitivity of 78% and specificity of 90% for detecting pathology compared to MR arthrography.

CONCLUSION

Capsule and plantar plate pathology occurs in the painful forefoot of patients with RA and is associated with features of disease and deformity at the lesser MTP joints. Compared with MR arthrography, standard MR imaging was highly specific and moderately sensitive for diagnosing lesser MTP joint pathology in patients with RA.

Diagnosis of plantar plate injury by magnetic resonance imaging with reference to intraoperative findings

The objective of the present study was to assess the utility of magnetic resonance imaging in evaluating injury to the plantar plate and to determine whether conventional low-field magnetic resonance imaging is a valid tool for diagnostic evaluation. Magnetic resonance imaging scans of 45 feet in 41 patients (38 females and 3 males, with an average age of 52.1 years) were prospectively evaluated to assess the integrity of the plantar plate ligament and compared with a reference standard of intraoperative findings. The concordance of tear severity observed on magnetic resonance imaging with the intraoperative findings was also assessed using a newly proposed grading scheme for plantar plate injuries. Intraoperatively, 41 plantar plate tears and 4 intact ligaments were found. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value was 96%, 95%, 100%, 100%, and 67%, respectively. The clinical diagnosis of plantar plate injury was also highly accurate in our study population (41/45, 91%). Finally, we observed moderate concordance between the magnetic resonance imaging grade and surgical grade of plantar plate tear (28/45, 62%), with greater concordance occurring at higher grades. Our results have demonstrated that magnetic resonance imaging is an accurate and valid test for the diagnosing injuries of the plantar plate ligament. Given the high accuracy of the clinical findings, magnetic resonance imaging is most useful when the decision to operate will be sufficiently influenced by either a normal magnetic resonance imaging appearance of the plantar plate or the presence of a high-grade tear.

Lesser metatarsophalangeal joint instability: prospective evaluation and repair of plantar plate and capsular insufficiency

BACKGROUND

Anatomical dissection of the second metatarsophalangeal (MTP) joint suggests that the plantar plate is the major stabilizing structure of the joint due to its central location and multiple important attachments. Many surgical procedures have been recommended when conservative treatment has failed, but some have had limited clinical success. The aim of our prospective study was to show the results obtained in the treatment of a group of patients with plantar plate tears by direct repair through a dorsal approach combined with a Weil metatarsal osteotomy with a minimum followup of 12 months.

METHODS

We prospectively treated 28 patients (55 MTP joints) with lesser MTP joint instability, but only 22 patients (40 MTP joints) were treated by the direct repair of the plantar plate and were included in the study. All of them had initial complaints of acute forefoot pain with the subsequent development of deformity and instability of the MTP joints. All patients were evaluated clinically, radiographically, (plain radiographs and MRI exam), and by MTP joint arthroscopy. With this data, a direct correlation between the clinical staging and the anatomical grading for plantar plate dysfunction of each patient was determined

RESULTS

The plantar plate of the second MTP joint was the most commonly affected joint (63%), and Grade III type tear (transverse and/or longitudinal extension tear) was the most frequent type. With the surgical treatment, we were able to markedly improve the parameters studied (pain, medial or dorsomedial deviation of the toe, joint stability, muscle balance, and joint congruence) to acceptable levels, The AOFAS score improved substantially from an average of 52 points preoperatively to 92 points postoperatively.

CONCLUSION

The direct plantar plate repair combined with a Weil osteotomy and lateral soft tissue reefing can restore the normal alignment of the MTP joint. We have demonstrated that the anatomic repair of the plantar plate can correct the deviation of the affected toe (medial, dorsal, dorsomedial or dorsolateral), which lead to diminished pain with improved functional scores.

MRI identifies plantar plate pathology in the forefoot of patients with rheumatoid arthritis

Previous cadaveric studies have suggested that forefoot deformities at the metatarsophalangeal (MTP) joints in patients with rheumatoid arthritis (RA) might result from the failure of the ligamentous system and displacement of the plantar plates. This study aimed to examine the relationship between plantar plate pathology and the rheumatoid arthritis magnetic resonance imaging score (RAMRIS) of the lesser (second to fifth) MTP joints in patients with RA using high-resolution 3 T magnetic resonance imaging (MRI). In 24 patients with RA, the forefoot was imaged using 3 T MRI. Proton density fat-suppressed, T2-weighted fat-suppressed and T1-weighted post gadolinium sequences were acquired through 96 lesser MTP joints. Images were scored for synovitis, bone marrow oedema and bone erosion using the RAMRIS system and the plantar plates were assessed for pathology. Seventeen females and 7 males with a mean age of 55.5 years (range 37–71) and disease duration of 10.6 years (range 0.6–36) took part in the study. Plantar plate pathology was most frequently demonstrated on MRI at the fifth MTP joint. An association was demonstrated between plantar plate pathology and RAMRIS-reported synovitis, bone marrow oedema and bone erosion at the fourth and fifth MTP joints. In patients with RA, 3 T MRI demonstrates that plantar plate pathology at the lesser MTP joints is associated with features of disease severity. Plantar plate pathology is more common at the fourth and fifth MTP joints in subjects with RA in contrast to the predilection for the second MTP reported previously in subjects without RA.