3D isotropic MRI of ankle: review of literature with comparison to 2D MRI

The ankle joint has complex anatomy with different tissue structures and is commonly involved in traumatic injuries. Magnetic resonance imaging (MRI) is the primary imaging modality used to assess the soft tissue structures around the ankle joint including the ligaments, tendons, and articular cartilage. Two-dimensional (2D) fast spin echo/turbo spin echo (FSE/TSE) sequences are routinely used for ankle joint imaging. While the 2D sequences provide a good signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) with high spatial resolution, there are some limitations to their use owing to the thick slices, interslice gaps leading to partial volume effects, limited fluid contrast, and the need to acquire separate images in different orthogonal planes. The 3D MR imaging can overcome these limitations and recent advances have led to technical improvements that enable its widespread clinical use in acceptable time periods. The volume imaging renders the advantage of reconstructing into thin continuous slices with isotropic voxels enabling multiplanar reconstructions that helps in visualizing complex anatomy of the structure of interest throughout their course with improved sharpness, definition of anatomic variants, and fluid conspicuity of lesions and injuries. Recent advances have also reduced the acquisition time of the 3D datasets making it more efficient than 2D sequences. This article reviews the recent technical developments in the domain 3D MRI, compares imaging with 3D versus 2D sequences, and demonstrates the use-case scenarios with interesting cases, and benefits of 3D MRI in evaluating various ankle joint components and their lesions.

Indications and possible limitations using medio-plantar plate systems in tarsometatarsal 1 fusions - A cadaveric study

BACKGROUND

The tarsometatarsal 1 arthrodesis is an adequate treatment for moderate to severe hallux valgus deformity and instability of the first ray. Plantar plating arthrodesis has been shown to provide better mechanical stability and fewer postoperative complications than screw fixation or medial plating. The medio-plantar plate is a new plate design for Lapidus arthrodesis. It could combine the biomechanical advantages of the plantar plate and the anatomical overview of a medial plate. However, the implanted material can cause irritation of the tibialis anterior, which in some cases may require removal of the material. The purpose of this study was to examine the possibility of tendon irritation following medio-plantar first tarsometatarsal joint arthrodesis using cadaveric specimens.

METHODS

The study involved the simulated surgical procedure of medio-plantar plate arthrodesis on 30 lower extremities. After the plates were fixed, a thorough examination of the feet was conducted to assess any tendon irritation and to determine a recommendation for placement of the medio-plantar plate based on the Olewnik classification.

RESULTS

Irritation of the tibialis anterior tendon components with the medio-plantar plate depends mainly on the anatomic norm variant, classified according to Olewnik et al. A medio-plantar plate is particularly recommended in TA tendon Olewnik type 3 and type 5. The positioning of a medio-plantar plate in Olewnik type 1 and type 2 tendons depends on the anatomic fit of the medio-plantar plate and the bony configuration of the TMT 1 joint. A large portion of the TA tendon must be detached, so a different plate design may be preferred in these patients.

CONCLUSIONS

TMT 1 arthrodesis with medio-plantar plating of the first tarsometatarsal joint should be performed considering the anatomic TA tendon variations.

LEVEL OF EVIDENCE

Level V, Expert Opinion includes Case Reports and Technique Tips.

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.

Nonoperative Treatment of Plantar Plate Tears

The plantar plate is a critical structure involved in stabilizing the metatarsophalangeal joint. Its disruption can not only be painful for the patient but also may lead to subsequent structural deformities. There are several conservative treatment modalities available to help mitigate symptoms including splinting, offloading, and intraarticular injections. That being said, once the pathology progresses to advanced stages, these treatments are not efficacious. Reported success with conservative treatment modalities is limited to case studies and series with a low level of clinical evidence. As such, this represents an area where further investigation is needed to evaluate the true efficacy of conservative treatment and to allow for development of a more standardized approach.

Update on Fibrocartilaginous Disease Clinical Examination

This article provides an update on fibrocartilaginous disease clinical examination. Lesser metatarsophalangeal joint instability is a challenging entity for the foot and ankle surgeon. A correct diagnosis is crucial to instill an appropriate treatment plan that will result in a successful outcome and a satisfied patient. Insertional Achilles tendon disorders are common among active and inactive patients. There is also a high predilection for Achilles tendon pathology among athletes. In this article demographics and patient history, causative factors, differential diagnosis, physical examination, clinical tests, and radiographic evaluation are discussed for plantar plate disorders and insertional Achilles disorders.

Anatomy: Plantar Plate

The fibrocartilaginous component of the plantar plate offers stability at the metatarsophalangeal joint. In conjunction with the attachments of the deep transverse metatarsal ligaments and collateral ligaments, the plantar plate complex resists tensile forces anchored by the plantar fascia and compression forces under the metatarsal heads.

Operative Management: Plantar Plate

The plantar plate is a vital structure for maintaining lesser metatarsophalangeal joint (MPJ) stability. Its primary role is to provide static stabilization of the MPJs, working in conjunction with the long and short flexor and extensor tendons. When insufficiency or attenuation of the plantar plate occurs, a sagittal plane deformity will slowly develop, eventually leading to a "crossover toe" transverse plane deformity. Coughlin coined this descriptive term to describe the later stages of deformity, most commonly affecting the second MPJ. Shortly after, Yu and Judge elaborated on this condition describing it as "predislocation syndrome," an inflammatory condition affecting the plantar plate causing pain and instability, which could progress to subluxation at the MPJ.

Transverse laxity of the forefoot

BACKGROUND

Splay of the forefoot reflects the loss of tension in the soft tissues and indicates failure of the biomechanics of the tie-bar system. By identifying and quantifying the soft tissue structures involved in the destruction of forefoot stability we could increase the understanding of forefoot pathologies.

METHODS

We investigated the transverse forefoot laxity on healthy feet, feet with forefoot pathology and cadaveric feet undergoing sequential dissection.

RESULTS

Statistical difference in transverse laxity was seen between healthy feet (n = 160) and feet with symptomatic forefoot pathology requiring surgery (n = 29). Presence of lesser ray pathology is associated with increased transverse laxity. For the dissected cadaveric feet (n = 9) sequential sectioning the plantar plate causes a progressive evolution of transverse laxity. The repair of plantar plates greatly improves transverse stability.

CONCLUSIONS

Forefoot pathology causes increased transverse laxity. In case of a major transverse laxity of the forefoot a plantar plate lesion should be suspected.

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.

Imaging of Turf Toe

Turf toe is a common injury of the hallux metatarsophalangeal (MTP) joint in athletes which is the result of hyperdorsiflexion injury. While the term turf toe has been used to describe a variety of first MTP joint injuries, the term is now typically used in imaging to describe tearing or injury to the plantar plate complex. This review article will cover normal anatomy of the first MTP joint, mechanism of injury, typical imaging findings in normal individuals on MRI and ultrasound, as well as the most common patterns of injury.

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.

In-Season Management of Acute and Subacute Sports Foot Injuries

In athletes, foot injuries present with a variety of mechanisms, severity, and implications for return to play. Although potentially given less attention than knee and shoulder injuries by the team physician, foot injuries are common and thus require knowledgeable consideration. In this article, we review the anatomy, presentation, workup, and management of several of the most common athletic foot injuries, including turf toe, Lisfranc injuries, Jones fractures, and navicular stress fractures. The goal is to provide the team physician with the information necessary to evaluate and manage these injuries on the sideline and in the training room.

Assessment and Treatment of Sports Injuries to the First Metatarsophalangeal Joint

Turf toe injuries have been increasing in numbers in recent years. Injury to the plantar restraints of the first metatarsophalangeal joint can lead to significant disability in athletes, affecting their push-off and ability to perform on the athletic field. Most turf toe injuries can be treated conservatively with rest, ice, compression, immobilization if needed, and a dedicated rehabilitation program; however, in some injuries, the plantar restraints are torn and the joint becomes unstable. If necessary, turf toe injury and its many variants can be surgically repaired with the expectation that the athlete will be able to return to play.

Anatomical study of Lapidus arthrodesis using two different plantar plate systems

BACKGROUND

First tarsometatarsal arthrodesis (modified Lapidus procedure) constitutes a sufficient treatment for moderate to severe hallux valgus deformity and first ray instability. The plantar plate arthrodesis was shown to provide superior mechanical stability and less postoperative complications than screw fixation or dorsal plating. Nevertheless, the in-brought hardware may cause irritation of the tibialis anterior or peroneus longus tendon requiring explantation of the material in some cases. The purpose of this study was to investigate the potential of tendon irritation after plantar first tarsometatarsal joint arthrodesis in a cadaver study.

METHODS

Plantar plate arthrodesis was performed as in real surgery on twelve pairs of fresh frozen cadaveric feet. Two different plate systems were randomly allocated to each pair of feet. After plate fixation careful dissection of the feet followed to analyze potential tendon irritation and to determine a "safe zone" for plantar plate placement.

RESULTS

A "safe zone" between the insertion sties of tibialis anterior and peroneus longus tendon was found and proven to be sufficiently exposed using a standard medio-plantar approach. Both plates were fixed in this zone without compromising central tendon parts. Peripheral tendon parts were irritated in 42% using Darco Plantar Lapidus Plating System® (Wright Medical, Memphis, TN) and in 8% using the Plantar Lapidus Plate® (Arthrex, Naples, FL). Bending of the anatomically preshaped plates is often necessary to ensure optimal fit on the bone surface.

CONCLUSIONS

Modified Lapidus procedure with plantar plating of the first tarsometatarsal joint can be performed safely without compromising central tendon parts via standard medio-plantar approach.

LEVEL OF CLINICAL EVIDENCE

5, Cadaver Study.

Outcomes of Chronic Turf Toe Repair in Non-athlete Population: A Retrospective Study

BACKGROUND

Turf toe injuries, though most common in athletes, can also occur in non-athletes. No study exists in the current literature investigating operative outcomes in non-athlete patients with chronic turf toe injury. In this study, we present our outcomes on operatively treated turf toe injuries in non-athletes in the only cohort yet studied.

METHODS

Using ICD-10 codes, we assembled a cohort of 12 patients who underwent operative repair of chronic turf toe injury from January 2012 through January 2018 at the investigating institution. These 12 patients were evaluated to determine demographic information, method of injury, length of time from injury to surgery, clinical and radiologic characteristics of the injury, and operative outcomes including mean preoperative and postoperative VAS (Visual Analog Scale) scores, preoperative and postoperative FFI (Foot Function Index) scores, and postoperative complications.

RESULTS

On initial clinical presentation, all 12 patients had local tenderness with associated painful range of motion. Four patients had restricted range of motion, all patients had a positive Lachman test, two had local edema, and eight had hallux valgus deformity. Mean VAS improved from 4.6 (range 2-9) to 1 (range 0-4). Mean FFI improved from 102.5 (range 56-177) to 61.75 (range 23-144). All patients had a negative Lachman test at final follow-up. No patients developed major complications or required revision surgery.

CONCLUSIONS

Our study is the first to investigate operative outcomes following chronic turf toe injury in non-athlete patients. Based on our study, surgeons and patients can expect significant improvement in overall pain and function following surgery.

First MTP joint instability - Expanding the concept of "Turf-toe" injuries

BACKGROUND

Although the classic definition of the Turf-toe injury refers to a very specific clinical and pathological picture, we think that the concept can be broadened to encompass a wide variety of traumatic lesions of the first metatarsophalangeal joint (MTP1). These are lesions typically difficult to diagnose, with a large variation of outcomes and a potential to impair patients' functional performance on a definitive and perennial basis. The objective of this study is to present the result obtained by treating 24 cases of traumatic injuries to the MTP1 joint in a midterm follow-up time.

METHODS

In the period from 1999 to 2016, 24 patients were treated with MTP1 joint instability - "Expanded Turf-toe" - diagnosis. All patients were performing sports activities when they were injured: soccer (33%); martial arts (17%); running (13%); tennis (8%); olympic gymnastics (8%) and others (basketball, slalom, motorcycling, surfing, and ballet) (21%). Injuries were classified as Grade I (2 patients - 8%), Grade II (8 patients - 33%) and Grade III (14 patients - 59%) lesions. All patients with grades I and II were treated conservatively whereas those classified as grade III were treated surgically.

RESULTS

After an average follow-up of 4.5 years we observed an improvement in the AOFAS hallux score from 42 to 82 points after treatment (p<0.001). The most frequent cause was axial load with various direction of stress at the first MTP. The mechanism of lesion varied among extension with hallux varism (42%), pure hyperextension (25%), extension with hallux valgism (21%), pure hyperflexion (8%) and hyperflexion with hallux valgism (4%). A separate analysis of each group showed a significant improvement in AOFAS Hallux scores after treatment: 51-84 (p<0.001) and 36-81 (p<0.001) for conservative and surgical groups, respectively. Four patients with GIII injuries (29%) and two with GII injuries (20%) did not resume their previous activities. Although pre-treatment AOFAS hallux scores were significantly different between groups, post-treatment scores were similar (p=0.615).

CONCLUSIONS

Turf-toe is a serious injury that may prevent a high percentage of patients from resuming their previous physical activities. Mechanism of lesion might be varied generating a wide range of lesions that fit into the expanded concept of the Turf-toe injury. Both forms of treatment lead to satisfactory results if well conducted. The correct identification, classification, and grading of first metatarsophalangeal joint (MTP) instability helps in decision making and selection of the adequate treatment.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Forefoot Pain in the Lesser Toes: Anatomical Considerations and Magnetic Resonance Imaging Findings

Various conditions may result in forefoot pain. Magnetic resonance (MR) imaging allows accurate assessment of many of these conditions. We provide an overview of forefoot disorders divided into bones, capsule and plantar plate, musculotendinous structures, neurovascular structures, and subcutaneous tissue. We review normal anatomical features as well as MR imaging findings of common disorders.

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.

Turf Toe: An Update and Comprehensive Review

Turf toe is a spectrum of injury involving the first metatarsophalangeal joint originally described in football players on artificial surfaces. A detailed description of the complex anatomy and pathology involved in the turf toe injury is presented. We highlight potential pitfalls of image interpretation and emphasize what the referring physician needs to know.

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.

Anatomy and Physiology of the Lesser Metatarsophalangeal Joints

Knowledge and command of anatomy is paramount to effectively treating disorders of the lesser metatarsophalangeal (MTP) joints. The osseous structures consist of the proximal phalanx of the toe and the metatarsal head. The soft tissues on the dorsum of the MTP joint include the joint capsule and the tendons of extensor digitorum longus and extensor digitorum brevis. The proper and accessory collateral ligaments form the medial and lateral walls and contribute to stability in the coronal and sagittal planes. The plantar plate forms the plantar border of the MTP joint and stabilizes the MTP joint against hyperextension and dorsal translation.

Effectiveness of the Cobb-Stainsby excision arthroplasty

BACKGROUND

Dislocated metatarsophalangeal joints from clawed or hammer toes can be a disabling consequence of several conditions. The Cobb-Stainsby forefoot arthroplasty combines partial phalangectomy (Stainsby) with extensor tendon transfer to the metatarsal head (Cobb). We present a retrospective, three surgeon case series of 215 toes in 126 patients.

METHODS

Early results and complications were gathered from the medical charts of 126 patients who met the inclusion criteria. Seventy-five patients were contactable by phone with a follow up range of 12-82 months (median follow up 45 months). Primary outcome measures were improvement of pain and function, reduction in plantar callosities and cosmetic improvement of the deformity.

RESULTS

Pre-operatively all patients presented with pain and shoe wear problems. Post-operatively seventy-two patients (96%) were satisfied, 72 (96%) reported pain relief, 55 (73%) were happy with toe control, 61 (81%) were pleased with cosmesis and 56 (75%) reported unlimited daily activities. Superficial wound infections were observed in 13 of the 126 patients (10%) and two in 75 patients (2%) developed recurrent clawing.

CONCLUSION

Our case series demonstrates improved outcomes over alternatives such as the Weil's osteotomy.

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.

Modified double plantar plate tenodesis

BACKGROUND

Metatarsophalangeal joint instability of the lesser toe can cause acquired toe deformity. Plantar plate deficiency is the major pathology. Plantar plate repair can stabilize the joint but may result in iatrogenic transverse plane toe deformity in correction of claw toe deformity. Limited toe extension can be resulted after correction of crossover toe deformity by plantar plate tenodesis and extensor digitorum brevis transfer. A modification of the technique is proposed.

MATERIALS AND METHODS

The clinical outcomes of 10 patients with the modified procedure performed were assessed.

RESULTS

The correction was full in all toes with no recurrence.

CONCLUSION

The modified technique can stabilize the metatarsophalangeal joint and correct lesser toe deformity without the need of tendon transfer, osteotomy or sophisticated instrumentation.

Metatarsophalangeal joint stability: a systematic review on the plantar plate of the lesser toes

Background

Instability of the metatarsophalangeal (MTP) joints of the lesser toes (digiti 2–5) is increasingly being treated by repair of the plantar plate (PP). This systematic review examines the anatomy of the plantar plate of the lesser toes, and the relation between the integrity of the plantar plates of the lesser toes and lesser MTP joint stability.

Methods

The databases of Embase.com, Medline (Ovid), Web of Science, Scopus, Cochrane, Pubmed not medline, Cinahl (ebsco), ProQuest, Lilacs, Scielo and Google Scholar were searched in June 2015 from inception. Studies were included if they were in English, contained primary data, and had a focus on plantar plate anatomy of the lesser toes or on the relationship between integrity of the plantar plate and MTP joint (in)stability. Study characteristics were extracted into two main tables and descriptive anatomical and histological data were summarized into one schematic 3D drawing of the plantar plate.

Results

Nine studies were included in this systematic review, of which five addressed plantar plate anatomy as such and four focused directly and indirectly on plantar plate integrity related to MTP joint stability.

Conclusion

This is the first systematic review regarding plantar plate anatomy related to MTP joint stability of the lesser toes. This review iterates the importance of plantar plate anatomy and integrity for MTP joint stability, and it delineates the lack of primary data regarding plantar plate anatomy of the lesser toes and MTP joint stability.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-016-0165-2) contains supplementary material, which is available to authorized users.

Predictive MRI correlates of lesser metatarsophalangeal joint plantar plate tear

PURPOSE

To identify correlated signs on non-enhanced MRI that might improve diagnostic detection of plantar plate (PP) tear.

MATERIALS AND METHODS

We performed an IRB-approved, HIPAA-compliant retrospective analysis of 100 non-contrast MRI (50 PP tear, 50 controls). All were anonymized, randomized, and reviewed; 20 were duplicated to assess consistency. One musculoskeletal radiologist evaluated qualitative variables. A trained non-physician performed measurements. Consistency and concordance were assessed. Pearson's Chi-square test was used to test the correlation between qualitative findings and PP tear status. Correlation between measurements and PP status was assessed using t tests and Wilcoxon's rank-sum test (p values < 0.05 considered significant). Classification and regression trees were utilized to identify attributes that, taken together, would consistently distinguish PP tear from controls.

RESULTS

Quantitative measurements were highly reproducible (concordance 0.88-0.99). Elevated 2nd MT protrusion, lesser MT supination and rotational divergence of >45° between the 1st-2nd MT axis correlated with PP tear. Pericapsular soft tissue thickening correlated most strongly with PP tear, correctly classifying 95 % of cases and controls. Excluding pericapsular soft tissue thickening, sequential assessment of 2nd toe enthesitis, 2nd flexor tendon subluxation, and splaying of the second and third toes accurately classified PP status in 92 %.

CONCLUSIONS

Pericapsular soft tissue thickening most strongly correlated with PP tear. For cases in which it might be difficult to distinguish pericapsular fibrosis from neuroma, sequential assessment of 2nd toe enthesitis, flexor tendon subluxation and splaying of the 2nd and 3rd toe is most helpful for optimizing accurate diagnosis of PP tear.

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.

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.

Lesser Metatarsal Osteotomy

Central metatarsal osteotomy is an effective approach in alleviating pain oriented to the forefoot. The procedures individually are straightforward in the isolated scenario. A working knowledge of the specific and unique pathobiomechanics is imperative when considering surgical intervention for the given pathologic scenario. Treating only the pain focus generally underserves the pathology and does not address the high point of the deformity. The surgeon must be cognizant of the complication potpourri, prepare the patient expectations, and engage a level of proactivity against sequelae to ensure the best possible and most predictable outcome.

Turf toe and sesamoiditis: what the radiologist needs to know

The first metatarsophalangeal (MTP) joint complex is a critical weight-bearing structure important to biomechanics. An acute dorsiflexion injury, named "turf toe," is common among American football and soccer players. "Sesamoiditis" is a name often given for pain arising from the hallux sesamoids in the absence of acute trauma, and may result from a variety of causes. The first MTP joint complex can also be affected by degenerative or inflammatory arthritis, infarct, and infection. This review article will cover the anatomy and biomechanics of the first MTP joint complex, its patterns of injury and pathology, imaging techniques, and management.

Etiology and management of lesser toe metatarsophalangeal joint instability

The terms crossover toe and lesser metatarsophalangeal joint instability both describe a deterioration of the soft tissue structures that give stability to the lesser MTP joints. Initial treatment regimens focused on indirect repair of the instability without addressing the primary pathology. A staging system of the clinical examination and a grading system of the surgical findings are now available to help surgeons classify and treat the plantar plate insufficiency. Improved imaging techniques and direct surgical repair techniques through a dorsal approach have changed the treatment and possibly the results of this difficult condition.

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.