Second metatarsophalangeal joint arthrography: a cadaveric correlation study

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.

Plantar Plate Repair for Metatarsophalangeal Joint Instability of the Lesser Toes

The plantar plate is a known stabilizer of the lesser toe metatarsophalangeal (MTP) joint. MTP instability is a known common cause of metatarsalgia, most commonly in the second toe. In the last decade, clinical staging and anatomic grading mechanisms have been published to guide the surgeons on the treatment of MTP instability; this has also led to an understanding of how plantar plate tears relate to MTP joint instability. Direct surgical repair of the plantar plate has been described, short-term outcomes have been published, and the results are not perfect, but promising with respect to patient satisfaction and pain relief.

Use of Metatarsophalangeal Joint Dorsal Subluxation in the Diagnosis of Plantar Plate Rupture

A dorsal drawer exam, also known as a modified Lachman's test, is a common clinical test for plantar plate insufficiency. This disorder presents as a dislocated metatarsophalangeal joint. The aim of this cadaveric case study was to quantify the degree of the plantar plate pathology necessary to correlate with a positive Lachman's test. The second metatarsophalangeal joint was tested on 18 cadaveric lower extremities. Limbs with previous digital surgery or with an obvious digital deformity were excluded from this study. A plantar linear incision over the plantar aspect of the second metatarsophalangeal joint was performed, and the flexor tendons were retracted to expose the plantar plate. After evaluating the plantar plate's integrity and measuring its width, a Lachman's test was then performed under fluoroscopy. The plantar plate was subsequently severed in a serial manner in 2-mm increments. A modified Lachman's test was performed with the different levels of rupture to assess the degree of dislocation. We found that a tear as small as 2 mm, detected in 12 (66.7%) of 18 specimens, produced gross instability in the second metatarsophalangeal joint. We also showed that a simulated plantar plate tear ≥4 mm but <6 mm resulted in joint subluxation (positive modified Lachman's test) with a sensitivity of 90.3%. This study reinforces the finding that a modified Lachman's test is a clinical exam that demonstrates high sensitivity in diagnosing plantar plate insufficiency.

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.

Extensor apparatus of the lesser toes: anatomy with clinical implications--topical review

Lesser toe deformities are one of the most common conditions faced by orthopedic surgeons. Knowledge of the anatomy of the lesser toes is important for ensuring correct diagnosis and treatment of deformities, which are caused by factors such as muscle imbalance between the extensor apparatus and flexor tendons. However, this apparatus has not received sufficient attention in the literature. In addition, the large number of inaccurate and erroneous descriptions means that gaining an understanding of these structures is problematic. The objective of the present article is to clarify the anatomy of the extensor apparatus by means of a pictorial essay, in which the structures involved will be grouped and discussed in detail. The most relevant clinical implications will be addressed.

LEVEL OF EVIDENCE

Level V, expert opinion.

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.

Technique using interference fixation repair for plantar plate ligament disruption of lesser metatarsophalangeal joints

Lesser metatarsophalangeal joint instability is a challenging disorder for the foot and ankle surgeon to repair. We believe that disruption of the plantar plate is common, and its repair should be carefully considered. However, we believe that most current techniques inadequately address repair of the complete plantar plate ligament tear, and, thus, instability and pain commonly persist after disruption of the plantar plate. In the present report, we present a technique we have found useful for repair of a complete plantar plate ligament rupture. The method we have described uses interference screw fixation through a dorsal incision to stabilize the lesser metatarsophalangeal joint.

Metatarsophalangeal joint instability of the lesser toes and plantar plate deficiency

Our understanding of lesser toe metatarsophalangeal joint instability has increased substantially over the past few decades. Some recent articles on the subject have provided detailed anatomic descriptions that help to characterize the primary stabilizing structures of the joint. Some surgeons now advocate the incorporation of a primary repair of the plantar plate into the surgical plan for correction of metatarsophalangeal joint deviation in the sagittal and transverse planes. New surgical techniques have been developed to expose, inspect, and reliably repair the plantar plate, if necessary. Dorsal and plantar approaches have both been used successfully to repair the plantar plate. Tears of the plantar plate can be repaired primarily or advanced on the base of the proximal phalanx through bone tunnels. Outcomes of these procedures are promising, with improvements in pain and function reported along with sustained deformity correction.

The direct plantar plate repair technique

Lesser metatarsophalangeal (MTP) joint instability is a common and painful condition that can severely limit activity and recreation. Synovitis and joint effusion may be seen early on with progression of instability to encompass predislocation and eventual complete dislocation of the MTP joint. Various surgical techniques have been described to treat lesser MTP joint instability and associated hammertoe deformities. Many surgeons experience frustration with the surgical outcome of metatarsal osteotomies and flexor transfers commonly used for this condition. The plantar plate apparatus is felt to be at the heart of the pathomechanics of this condition in many instances and is often misunderstood or even overlooked. Indirect dorsal approaches to plantar plate repair often require reliance on complex instrumentation and provide a limited view of the involved structures. The authors describe a direct plantar approach technique for plantar plate repair with realignment of the lesser MTP joint and hammertoe pathologies.

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.

Metatarsophalangeal joint instability of the lesser toes

Metatarsophalangeal joint instability of the lesser toes is a common finding and a common cause of metatarsalgia. The clinical presentation can include swelling without digital deformity; however, often, this can progress to the development of coronal and transverse plane malalignment. In some cases, frank metatarsophalangeal joint dislocation can develop. The treatment regimen has historically focused on indirect surgical realignment using soft tissue release, soft tissue reefing, tendon transfers, and periarticular osteotomies. An improved understanding of the plantar plate has recently led to the development of a clinical staging system and surgical grading system of plantar plate attenuation. A dorsal surgical approach, using a Weil osteotomy, allows the surgeon to directly access and repair or advance the plantar plate to the base of the proximal phalanx. The addition of direct plantar plate repair could be a significant advancement in the reconstruction and realignment of metatarsophalangeal joint instability.

Flouroscopic arthrography versus MR arthrography of the lesser metatarsophalangeal joints for the detection of tears of the plantar plate and joint capsule: a prospective comparative study

BACKGROUND

Derangements of the plantar plate and joint capsule are an underrecognized cause of lesser metatarsalgia. Fluoroscopic arthrography and magnetic resonance (MR) arthrography are both used for diagnosis. Currently there are no studies comparing the effectiveness of these two modalities.

METHODS

Patients suspected of having plantar plate or capsular tears underwent both fluoroscopic arthrography and MR arthrography; the imaging findings were then compared and correlated with intraoperative findings, when available, to evaluate the effectiveness of the different imaging modalities. Forty consecutive patients underwent both fluoroscopic and MR arthrography.

RESULTS

Thirty-two of 40 patients (80%) were found to have tears of the plantar plate, joint capsule, or both. MR arthrography identified all 32 tears. Four cases in the first 29 patients, 13.8%, demonstrated discrepancy where a tear was identified only on the MR arthrogram. A midpoint review of the data was performed. Of the 4 missed tears they were all noted to be plantar lateral in location. Four other patients in this group had plantar lateral tears that were not missed. These patients had an additional steep lateral oblique image on fluoroscopic arthrography, which showed the plantar lateral tear. Therefore an additional steep lateral oblique image was performed routinely capturing these small tears in the last 11 patients.

CONCLUSION

MR arthrography was more accurate in identifying tears of the plantar plate and capsule than fluoroscopic arthrography. Fluoroscopic arthrography with additional views, like a steep lateral oblique view, was found to be as reliable, and more cost-effective, than MR arthrography.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

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.

Hammertoe surgery: arthroplasty, arthrodesis or plantar plate repair?

In cases of painful complex hammertoe deformity, there is no single approach that can be used in all circumstances. If conservative care fails, surgical management may include interphalangeal joint arthroplasty, arthrodesis, and/or plantar plate repair. The best and most pragmatic surgical plan must be patient-centered, taking the age, activity level, expectations of the patient, and precise etiology of the hammertoe deformity into account.

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.

Metatarsophalangeal joint pathology in crossover second toe deformity: a cadaveric study

BACKGROUND

Ligamentous and capsular insufficiency of the second metatarsophalangeal joint has been surgically treated for over two decades, mainly with indirect surgical repairs, which stabilize adjacent soft tissue and shorten or decompress the osseous structures. While ligamentous insufficiency has been described and recognized, degeneration of the plantar plate and tears of the capsule have rarely been documented. The purpose of this study was to document and describe the presence and pattern of plantar plate tears in specimens with crossover second toe deformities, and based on this, to develop an anatomical grading system to assist in the assessment and treatment of this condition.

METHODS

Sixteen below-knee cadaveric specimens with a clinical diagnosis of a second crossover toe deformity were examined, and dissected by removing the metatarsal head. The pathologic findings of plantar plate and capsular pathology, as well as ligamentous disruption, were observed and recorded. Demographics of the specimens were recorded, and simulated weightbearing radiographs were obtained prior to dissection so that pertinent angular measurements could be obtained.

RESULTS

Demographics demonstrated a high percentage of female specimens, and a typically older population that has been reported for this condition. Radiographic findings documented a high percentage of hallux valgus and hallux rigidus deformities. The MTP-2 and MTP-3 angles were divergent consistent with a crossover toe deformity. We consistently found transverse tears in the plantar plate region immediately proximal to the capsular insertion on the base of the proximal phalanx. With increasing deformity, wider distal transverse tears extending from lateral to medial were found. Midsubstance tears, collateral ligament tears, and complete disruption of the plantar plate were found in more severe deformities.

CONCLUSION

In this largest series of cadaveric dissections of crossover second toe deformities, we describe the types and extent of plantar plate tears associated with increasing deformity of the second ray. We present, based on these findings, an anatomic grading system to describe the progressive anatomic changes in the plantar plate.

Anatomic plantar plate repair using the Weil metatarsal osteotomy approach

The purpose of this study was to analyze the early results of a new technique for anatomic plantar plate repair and advancement using a Weil metatarsal osteotomy of the second metatarsal. The authors retrospectively reviewed medical records of 13 consecutive adult patients (15 feet) who underwent this procedure by a single surgeon. The authors recorded visual analog pain scale scores preoperatively and postoperatively and patient-reported clinical outcome measurement surveys during their final follow-up visit. At an average of 22.5 months (range, 13 to 33 months) follow-up, 11 of 13 patients (85%) reported improved function whereas 10 of 13 (77%) were either satisfied or very satisfied with the outcome. Postoperative scores on the American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal- Interphalangeal Scale averaged 85.7 on a scale of 100 (SD = 13.1, 95% CI = 79.1-91.5). Patients reported an average preoperative visual analog pain scale of 7.3 (SD = 1.6, 95% CI = 6.4-8.1) versus an average of 1.7 (SD = 1.8, 95% CI = 0.7-2.7) postoperatively. This was a significant reduction in pain rating (P < .0001, t = 8.9, df = 27). Complications included painful hardware and metatarsalgia. There were no cases of dehiscence, malunion, nonunion, or recurrent metatarsophalangeal joint subluxation. This unique surgical technique addresses metatarsal overload and the instability of the second metatarsophalangeal joint while allowing for anatomic repair of the plantar plate pathology.

Combined plantar plate and hammertoe repair with flexor digitorum longus tendon transfer for chronic, severe sagittal plane instability of the lesser metatarsophalangeal joints: preliminary observations

The plantar plate provides a substantial static support for the lesser metatarsophalangeal joints. Insufficiency involving tear, attenuation, or absence of this structure can result in significant sagittal plane instability and deformity. When a plantar plate tear is established and is unresponsive to conservative treatment, plantar plate repair is indicated to address symptoms and reestablish static joint stability. The authors hypothesized that combined plantar plate and hammertoe repair with flexor digitorum longus tendon transfer provides a viable surgical option to address chronic plantar plate tears with secondary joint instability and digital deformity. The authors retrospectively evaluated a case series of 18 consecutive patients (20 feet) who underwent this combined surgical strategy as the primary procedure to address severe, chronic sagittal plane instability of the lesser metatarsophalangeal joints. Other procedures were performed concurrently in all cases to address predisposing factors and concomitant deformities. Method of evaluation included a subjective, objective, and radiologic evaluation performed at least 1 year after their surgical procedure. Two rating systems were used: the Lesser Metatarsophalangeal-Interphalangeal Scale from the American Orthopedic Foot and Ankle Society, and another designed by the authors. The average postoperative American Orthopedic Foot and Ankle Society score was 83.2/100 and the average postoperative score with the authors' rating system was 87.7/100. All patients were satisfied with their postoperative result. Study results suggest combined plantar plate and hammertoe repair with flexor digitorum longus tendon transfer to be a viable option to address severe, chronic sagittal plane instability of the internal lesser metatarsophalangeal joints. ACFAS Level of Clinical Evidence: 4.

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

The purpose of this study was to establish the accuracy of ultrasound in the examination of the plantar plate by comparing it with MRI, or if available, surgical findings. The lesser metatarsophalangeal joint plantar plates of 40 symptomatic and 40 asymptomatic feet (160 asymptomatic and 160 symptomatic plantar plates) were examined with ultrasound and MRI. Patients treated with surgery were chosen on a clinical basis and provided surgical correlation for the imaging techniques. Symptomatic patients with metatatarsalgia and suspected metatarsophalangeal joint instability were referred by an orthopedic foot specialist; asymptomatic feet were obtained either through examination of the contralateral foot of the symptomatic patients or volunteers. Ultrasound detected 75/160 and 139/160 plantar plates torn in the asymptomatic and symptomatic groups, respectively. MRI detected 56/160 and 142/160 tears in the symptomatic and asymptomatic groups, respectively. The sensitivity of MRI and ultrasound with surgical correlation was calculated to be 87 and 96%, respectively, with poor specificity. Ultrasound correlates moderately with MRI in the evaluation of the plantar plate. Surgical correlations, although limited (n = 10), indicate ultrasound is superior to MRI with more accurate detection of tears.