Second MTP joint instability: grading of the deformity and description of surgical repair of capsular insufficiency

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.

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.

Toes Deformities in Cavovarus: How to Approach Them

Sagittal lesser toe deformities (LTD) are the most common in cavus foot. They are mainly the result of muscular imbalance between intrinsic and extrinsic muscles. Surgery is the second-line treatment if medical treatment fails. The aim of the present study was to provide an update on classification and surgical management of LTD in cavus foot including percutaneous procedures with a special focus on sagittal deformities. Joint sparing procedures are preferred for reducible LTD, whereas lesser toe fusions are used for rigid one in association with tendon transfer or percutaneous procedures depending of surgeon's experience and patient's clinical examination.

Turf Toe Injuries in the Athlete: an Updated Review of Treatment Options, Rehabilitation Protocols, and Return-to-Play Outcomes

PURPOSE OF REVIEW

First metatarsophalangeal joint sprains or turf toe (TT) injuries occur secondary to forceful hyperextension of the great toe. TT injuries are common among athletes, especially those participating in football, soccer, basketball, dancing, and wrestling. This review summarizes the current treatment modalities, rehabilitation protocols, and return-to-play criteria, as well as performance outcomes of patients who have sustained TT injuries.

RECENT FINDINGS

Less than 2% of TT injuries require surgery, but those that do are typically grade III injuries with damage to the MTP joint, evidence of bony injury, or severe instability. Rehabilitation protocols following non-operative management consist of 3 phases lasting up to 10 weeks, whereas protocols following operative management consist of 4 phases lasting up 20 weeks. Athletes with low-grade injuries typically achieve their prior level of performance. However, among athletes with higher grade injuries, treated both non-operatively and operatively, about 70% are expected to maintain their level of performance. The treatment protocol, return-to-play criteria, and overall performance outcomes for TT injuries depend on the severity and classification of the initial sprain. For grade I injuries, players may return to play once they experience minimal to no pain with normal weightbearing, traditionally after 3-5 days. For grade II injuries, or partial tears, players typically lose 2-4 weeks of play and may need additional support with taping when returning to play. For grade III injuries, or complete disruption of the plantar plate, athletes lose 4-6 weeks or more depending upon treatment strategy.

Republication of "Congenital Dislocation of the Fifth Metatarsophalangeal Joint in Adults: Operative Technique"

Congenital dislocation of the fifth metatarsophalangeal (MTP) joint can cause significant limitations in a patient's ability to wear a closed shoe. Historic treatment has involved amputation of the digit or attempts at reconstruction. These techniques have had limited success with unreliable correction and/or unacceptable cosmesis. The authors present a detailed, methodical approach to reconstruction of this deformity with a stepwise algorithm that addresses both the bony and soft tissue components of the deformity. With this modern technique, reliable and satisfactory results can be expected.

Lesser-toe deformity

Lesser-toe deformity is frequent and varied, with severe functional impact. In elderly subjects, it leads to loss of autonomy and increases the risk of falls. The aim of the present study was to provide an update on management, addressing 5 questions. What are the normal anatomy and pathophysiology? These acquired deformities mainly result from imbalance between the intrinsic and extrinsic muscles of the foot or from capsule-ligament stabilizer failure. How to analyze the deformity? It is important to identify the cause, site, reducibility and metatarsophalangeal joint stability. What are the main deformities and how should they be classified? Classifications used to be based on confusing terminology as the deformities were poorly defined. The French Foot Surgery Association (AFCP) therefore validated a classification with standardized, exhaustive and reproducible morphologic descriptions. What treatments are there? Treatment needs to take account of the cause. Footwear adaptation, physiotherapy and podologic measures are in first line, with surgery in second line. Surgery concerns soft tissues (tendon lengthening, tendon transfer, arthrolysis, plantar plate repair), bone (metatarsal and phalangeal osteotomy) and joints (replacement and fusion), with percutaneous and open approaches. What are the treatment strategies? Surgery is performed sequentially, from proximal to distal, if necessary. Options are set out in the decision-trees included in this article. LEVEL OF EVIDENCE: V, expert opinion.

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.

Direct Plantar Approach to Plantar Plate Repair and Associated Wound Complications

BACKGROUND

Lesser toe metatarsophalangeal joint (MTPJ) instability, secondary to plantar plate tear, has been the focus of numerous recent publications, the majority reporting on repair through a dorsal approach. A plantar approach has been described with the advantage of direct ligamentous repair or repair to bone, which follows conventional techniques employed throughout the body. Previous clinical studies have shown success in deformity correction and the longevity of both approaches. The proponents of the dorsal approach advocate that indirect repair of the plantar plate avoids perceived risks of complications with a plantar incision without evidence of superior outcomes. The purpose of this study was to investigate the safety and efficacy of the direct plantar approach to plantar plate repairs (PPRs) by reporting the rate of specific complications in a large clinical series.

METHODS

This was the institutional review board (IRB) approved retrospective study of 204 PPRs in 185 patients (194 lesser MTP, 10 hallux MTP) with an average age of 56 and a mean body mass index (BMI) of 28. Surgical technique involved repair with absorbable braided suture (88%) versus suture anchor (12%) with or without MTPJ pinning (80%). Mean follow up was 53 weeks (range 5-170). Patients were screened for associated risk factors, including diabetes mellitus (8%), tobacco use (5%), neuropathy (1%), and additional concurrent procedures (96%). Complications were defined as superficial or deep infection, painful scars, and reoperation. Analysis was conducted using the Wilcoxon-Mann-Whitney test or Fisher's exact tests for continuous and categorical variables, respectively. Risk factors were analyzed using univariate logistic analysis to produce odds ratios (OR) with a 95% confidence interval (CI) and an inclusion criterion of a P-value, P > .2 for multivariate analysis as determined by Wald tests (significance at P < .05 for final modeling).

RESULTS

Overall, there were 31 total complications (15%) demonstrated by 14 superficial infections (6.8%) and 17 painful scars (8.3%) along with three reoperations (1.4%). All reoperations were performed for deformity or instability, not scar revision. There were no deep infections. No increased odds of complications were found with suture anchor repair, MTPJ pinning, neuropathy, or diabetes. Patients that used tobacco had 7.5 (CI 1.66, 34.06) the odds of developing any wound complication compared with nonsmokers. Tobacco use was also found to significantly increase the odds of superficial infection by 9.8 (CI 2.08, 46.15). There was no increase in painful scars or reoperation in tobacco users. This study did not find an increased complication rate with additional ipsilateral procedures performed at the time of surgery.

CONCLUSION

To our knowledge, this is the largest study evaluating the direct plantar approach to PPR as well as the evaluation of associated complications with the plantar incision. With low complication and minimal reoperation rates, the results of this study have demonstrated the clinical viability of plantar-based incisions. Previous studies have demonstrated the success of PPR and correction of deformity with a direct approach. This case series further demonstrates the safety and efficacy of plantar-based incisions, particularly for direct PPRs.

LEVEL OF EVIDENCE

IV Retrospective Case Series.

CATEGORY

Lesser Toes.

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.

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.

Misdiagnosis of Extraskeletal Osteochondroma in the Foot: A Report of 3 Cases

CASES

Two women presented with newly growing callosities beneath the first and second metatarsal heads, initially believed to reflect gastrocnemius tightness and plantar plate pathology. In another man, swelling at the posterolateral aspect of the heel was mistaken for a Haglund deformity. Subsequent imaging of each patient led to delayed diagnosis of extraskeletal osteochondroma (ESO). Surgical excision resolved symptoms in all 3 with no recurrence over 12 months later.

CONCLUSIONS

Whenever bony prominences newly develop in soft tissues of the foot, ESO should be suspected and appropriate imaging obtained. We describe physical features to help differentiate ESO from other common causes of foot overload.

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.

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 versatile method for dorsal-approach plantar plate repair using standard operative instruments

Background

The plantar plate is an important static stabilizer of the lesser metatarsophalangeal joints, and disruptions of the plantar plate can lead to significant instability and lesser toe deformities. In recent years, direct plantar plate repair has been proposed. Although direct repair via a dorsal approach is attractive, a torn plantar plate is small and difficult to access using regular instruments in a restricted operative field.

Methods

In this report, a unique method for plantar plate repairs was used to repair various configurations of plantar plate tears with standard operative instruments that are available in most operating rooms.

Results

Using this method, 10 patients underwent plantar plate repairs, and the mean follow-up period was 24 (range, 14–38) months. The mean visual analog scale score for pain preoperatively was 4.1 (range, 0–6) and decreased to 0.6 (range, 0–3) at last follow-up. Postoperatively, the mean visual analog scale score for satisfaction was 9.6 (range, 8–10) and the mean American Orthopedic Foot and Ankle Society forefoot score was 88.8 (range, 75–100).

Conclusions

Our study proposes an inexpensive and versatile method for plantar plate repair via a dorsal approach that uses standard operative instruments.

Trial registration

ClinicalTrials.gov, NCT04949685. July 2, 2021 - Retrospectively registered,

Level of clinical evidence

4

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04951-w.

Flexor tenodesis procedure in the treatment of lesser toe deformities

In this technical report study, we describe the use of a flexor tenodesis procedure in the treatment of lesser toe deformities (LTD). Using a specific implant, both the flexor digitorum longus and brevis tendons are attached to the plantar aspect of the proximal phalanx, allowing dynamic correction of flexible deformities of metatarsophalangeal and interphalangeal joints. Good clinical results and absence of complications were observed in a series of 3 patients, with considerable correction of the LTD, and absence of substantial residual floating toe or metatarsophalangeal joint stiffness. LEVEL OF EVIDENCE: V - Technical Report/Case Report/Expert Opinion.

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.

Presence of Neovascularization in Torn Plantar Plates of the Lesser Metatarsophalangeal Joints

BACKGROUND

Recent surgical techniques have focused on anatomic repair of lesser toe metatarsophalangeal (MTP) plantar plate tears, yet it remains unknown whether the plantar plate has the biological capacity to heal these repairs. Therefore, a better understanding of the plantar plate vasculature in response to injury may provide further insight into the potential for healing after anatomic plantar plate repair. Recently, a study demonstrated that the microvasculature of the normal plantar plate is densest at the proximal and distal attachments. The purpose of this study was to compare the intact plantar plate microvasculature network to the microvasculature network of plantar plates in the presence of toe deformity using similar perfusion and nano-computed tomographic (CT) imaging methods.

METHODS

Seven fresh-frozen human cadaveric lower extremities with lesser toe deformities including hammertoe or crossover toe were perfused using a barium solution. The soft tissues of each foot were counterstained with phosphomolybdic acid (PMA). Then using nano-CT imaging, the second through fourth toe metatarsophalangeal joints of 7 feet were imaged. These images were then reconstructed, plantar plate tears were identified, and 11 toes remained. The plantar plate microvasculature for these 11 toes was analyzed, and calculation of vascular density along the plantar plate was performed. Using analysis of variance (ANOVA), this experimental group was compared to a control group of 35 toes from cadaveric feet without deformity and the vascular density compared between quartiles of plantar plate length proximal to distal. A power analysis was performed, determining that 11 experimental toes and 35 control toes would be adequate to provide 80% power with an alpha of 0.05.

RESULTS

Significantly greater vascular density (vascular volume/tissue volume) was found along the entire length of the plantar plate for the torn plantar plates compared to intact plantar plates (ANOVA, P < .001). For the first quartile of length (proximal to distal), the vascular density for the torn plantar plates was 0.365 (SD 0.058) compared to 0.281 (SD 0.036) for intact plantar plates; in the second quartile it was 0.300 (SD 0.044) vs 0.175 (SD 0.025); third quartile it was 0.326 (SD 0.051) vs 0.117 (SD 0.015); and fourth (most distal) quartile was 0.600 (SD 0.183) vs 0.319 (SD 0.082).

CONCLUSION

Torn plantar plates showed increased vascular density throughout the length of the plantar plate with an increase in density most notable in the region at or just proximal to the attachment to the proximal phalanx. Our analysis revealed that torn plantar plates exhibit neovascularization around the site of a plantar plate tear that does not exist in normal plantar plates.

CLINICAL RELEVANCE

The clinical significance of the increased vascularity of torn plantar plates is unknown at this time. However, the increase in vasculature may suggest that the plantar plate is a structure that is attempting to heal.

[Reconstruction of the plantar plate of the metatarsophalangeal joint using a dorsal transarticular approach]

OBJECTIVE

Reconstruction of the plantar plate to stabilize a dislocated or instable lesser metatarsophalangeal joint using a dorsal approach in combination with a Weil osteotomy.

INDICATIONS

Dislocated or instable lesser metatarsophalangeal joint with rupture of the plantar plate.

CONTRAINDICATIONS

Infection, circulatory disorders, symptomatic degenerative arthritis lesser metatarsophalangeal joint.

SURGICAL TECHNIQUE

Weil osteotomy using a dorsal approach. Temporary dislocation of the metatarsal head as proximal as possible. Inspection of the plantar plate. Assessment and classification of type and extent of the rupture. Suturing of the plantar plate to the plantar bases of the proximal phalanx. Fixation of the Weil osteotomy with correction of the metatarsal alignment.

POSTOPERATIVE MANAGEMENT

Weight bearing in a postoperative shoe as tolerated. X‑ray control 6 weeks postoperative. Full weight bearing in a conventional shoe after bony consolidation.

RESULTS

A total of 23 surgical reconstructions of the plantar plate (complete plantar plate repair) between 12/2012 and 10/2014 were performed. The mean follow-up was 18.6 (12-30) months. Five secondary dislocations were observed: one deep postoperative infection, one early dislocation of unknown cause, one secondary dislocation caused by severe hallux valgus recurrence, one massive foreign body reaction to the non-resorbable sutures, and one late secondary dislocation occurred between 6 weeks and 1 year postoperative. Normal function of the reconstructed joint was achieved in 13 of the 23 reconstructions (57%). A reduced toe purchase was observed in 3 reconstructions (13%). A floating-toe resulted after 7 reconstructions (30%).

Distal Metatarsal Segmental Shortening for the Treatment of Chronic Metatarsophalangeal Dislocation of Lesser Toes

BACKGROUND

This retrospective study aimed to describe the techniques and results of distal metatarsal segmental shortening (DMSS) for the treatment of chronic irreducible metatarsophalangeal (MTP) dislocation of lesser toes.

METHODS

We retrospectively reviewed patients who underwent DMSS for chronic dislocation of MTP joints of lesser toes between January 2010 and December 2017 with follow-up of at least 24 months. Demographic data, radiographic measurements, functional outcomes, and complications were analyzed. Furthermore, the results of patients with short segment of shortening (group I, <10 mm) were compared to those with long segment of shortening (group II, ≥10 mm). A total of 43 MTP joints of 30 patients with an average age of 70.4 years were included.

RESULTS

Union was observed in 42 metatarsals (97.7%). Mean American Orthopaedic Foot & Ankle Society scale scores improved significantly from 42.2 (range, 15-65) preoperatively to 79.1 (range, 52-90) (P < .001). Mean visual analog scale pain score improved significantly from 5.0 (range, 1-9) preoperatively to 1.8 (range, 0-6) (P < .001). Complications included 1 nonunion, 1 osteonecrosis, 3 metatarsal angulation, 4 recurrent instability, 4 symptomatic osteoarthritis, 3 transfer metatarsalgia, and 1 floating toe. Group I included 23 MTP joints and group II included 20 MTP joints. There was no significant difference in clinical outcomes and complications between the 2 groups.

CONCLUSION

DMSS was a reliable procedure for the treatment of chronic irreducible dislocated MTP joint of lesser toes. It provided satisfactory surgical outcomes and a low rate of postoperative complications, regardless of length of metatarsal shortening.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Is Second Metatarsal Protrusion Related to Metatarsophalangeal Plantar Plate Rupture?

OBJECTIVE. The purpose of this study was to determine whether the relative length of protrusion of the second metatarsal, measured on MRI and weight-bearing foot radiography, predicts the diagnosis of second metatarsophalangeal (MTP) joint plantar plate (PP) tear on MRI. MATERIALS AND METHODS. We retrospectively evaluated 166 consecutive patients (211 feet). Patients had undergone weight-bearing foot radiography and forefoot MRI. Using the Coughlin method, two independent observers measured second meta-tarsal protrusion length on radiography and MRI. MRI findings were classified as normal PP, complete PP tear, or degenerative or partial PP tear. RESULTS. Patients had a mean age of 47 ± 14.6 (SD) years, and 131 (78.9%) were women. MRI measurements were highly correlated with radiographic measurements (r = 0.882; 95% CI, 0.866-0.898; p < 0.001). A significant correlation was found between length of protrusion and cases classified as either normal PP or PP tear. Patients with a normal PP had a mean protrusion length of 4.11 ± 1.35 mm on radiographs and 2.61 ± 1.31 mm on MR images, whereas those with a PP tear had a mean protrusion length of 4.75 ± 1.53 and 3.05 ± 1.34 mm, respectively. ROC curve analysis showed that protrusion length cutoff values of 5.47 mm measured on radiographs and 3.17 mm on MR images were correlated with MTP PP tear. CONCLUSION. We identified a linear correlation between second metatarsal protrusion measured on MRI and that measured on radiography, with values about 35% higher for the latter. Our study showed an association between length of protrusion of the second metatarsal and PP rupture and identified a cutoff value for the second meta-tarsal overlength that is associated with these tears.

Lesser Metatarsophalangeal Instability: Diagnosis and Conservative Management of a Common Cause of Metatarsalgia

CONTEXT

Lesser metatarsophalangeal (MTP) instability is a common condition that can become debilitating and require surgery.

EVIDENCE ACQUISITION

An extensive literature review was performed through MEDLINE and Google Scholar for publications relating to the etiology, diagnosis, and treatment of lesser MTP instability using the keywords metatarsophalangeal instability, athlete, forefoot pain, and metatarsalgia from database inception to 2019.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Lesser MTP instability is a common condition, especially in the active and aging populations. It is frequently misdiagnosed, causing delays in treatment that allow for progressive pain and deformity, which prevents an active lifestyle. Fortunately, MTP instability can be diagnosed easily with the drawer test. Magnetic resonance imaging is helpful when still in doubt. Conservative treatment entails joint immobilization and gradual return to play with taping and offloading metatarsal pads.

CONCLUSION

Lesser MTP instability is a common diagnosis. Its early detection and conservative treatment can help the patient regain their previous level of activity and avoid surgery.

Mallet Toes, Hammertoes, Neuromas, and Metatarsophalangeal Joint Instability: 40 Years of Development in Forefoot Surgery

BACKGROUND

Today's foot and ankle surgeon has an enhanced understanding of forefoot pathology and treatment options compared to surgeons who practiced in previous decades. This paper summarizes developments in forefoot surgery in the past 40 years, specifically in treatments for mallet toe, hammertoe, neuroma, and metatarsophalangeal joint instability.

MATERIALS AND METHODS

A review of the literature was conducted using the PubMed search engine, with key terms including, "mallet toe," "hammertoe," "neuroma," "metatarsophalangeal joint instability," "plantar plate," and "forefoot surgery." Chapters in major orthopaedic textbooks covering these topics were also reviewed. We then chronicled the history of the diagnosis and treatment of these pathologies, with a focus on the past 40 years.

CONCLUSIONS

There have been major advances in understanding and treating forefoot pathologies in the past four decades; however, there remain areas for improvement both in the diagnosis and treatment of these problems.

LEVEL OF EVIDENCE

Level V, meta-synthesis.

An Innovative Method for Plantar Plate Repair: Technique Guide and Case Report

Disruption of the plantar plate is a common cause of forefoot pain, metatarsalgia, and metatarsophalangeal joint malalignment. Although surgical repair of the plantar plate has improved, there has been no consensus on the clinical superiority of any single technique, or combination of techniques, described in the literature to date. In this publication, we report a case of plantar plate injury treated with an innovative new technique with 20-month follow-up.

Lesser Metatarsophalangeal Joint Pathology Addressed With Arthrodesis: A Case Series

Lesser metatarsophalangeal joint pathology is a common condition facing the foot and ankle surgeon, often beginning as a mild subluxation of the toe and progressing to a full dislocation of the metatarsophalangeal joint. In severe or recalcitrant deformities, traditional conservative and surgical methods can fail to resolve the issue. We report on 4 patients with 5 severely dislocated lesser metatarsophalangeal joints with varied etiologies and comorbidities who underwent arthrodesis of these joints using screw and plate fixation. All patients achieved radiographic and clinical signs of union at an average of 16.4 weeks.

Overview of Metatarsalgia

Metatarsalgia can be viewed as more of a symptom rather than a distinct diagnosis. Timing of forefoot pain during the gait cycle and evaluation of whether the pain is from anatomic abnormalities, indirect overloading, or iatrogenic causes can suggest a specific metatarsalgia etiology. A thorough physical examination of the lower extremity, especially evaluation of the plantar foot, and weight-bearing radiographs are critical for diagnosis and treatment. Nonoperative treatment consists of physical therapy, orthotics, shoe wear modification, and injections. If conservative treatment fails, surgical options may be considered. [Orthopedics. 2019; 42(1):e138-e143.].

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.

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.

Congenital Dislocation of the Fifth Metatarsophalangeal Joint in Adults

Congenital dislocation of the fifth metatarsophalangeal (MTP) joint can cause significant limitations in a patient’s ability to wear a closed shoe. Historic treatment has involved amputation of the digit or attempts at reconstruction. These techniques have had limited success with unreliable correction and/or unacceptable cosmesis. The authors present a detailed, methodical approach to reconstruction of this deformity with a stepwise algorithm that addresses both the bony and soft tissue components of the deformity. With this modern technique, reliable and satisfactory results can be expected.

Lesser Metatarsophalangeal Joint Instability: Treatment with Tendon Transfers

Complex digital deformities and metatarsophalangeal joint instability encompass a wide range of pathology, and we must identify the different degrees of ligamentous disruption. It is important to address a combination of procedures to treat gross deformities of the lesser toes. Surgical treatment should be individualized and requires a sequential process for adequate reduction and deformity correction. There is no gold standard procedure for every deformity. Although residual stiffness can result from tendon transfer, overall patient satisfaction levels remain high when it is performed under the proper indications and concomitantly with other procedures to gain full correction of these challenging deformities.

Radiographic Shape of Foot With Second Metatarsophalangeal Joint Dislocation Associated With Hallux Valgus

BACKGROUND

Second metatarsophalangeal (MTP) joint dislocation is associated with hallux valgus, and the treatment of complete dislocation can be difficult. The purpose of this study was to radiographically clarify the characteristic foot shape in the presence of second MTP joint dislocation.

METHODS

Weight-bearing foot radiographs of the 268 patients (358 feet) with hallux valgus were examined. They were divided into 2 groups: those with second MTP joint dislocation (study group = 179 feet) and those without dislocation (control group = 179 feet). Parameters measured included the hallux valgus angle (HVA), first-second intermetatarsal angle (IMA), second MTP joint angle, hallux interphalangeal angle (IPA), second metatarsal protrusion distance (MPD), metatarsus adductus angle (MAA), and the second metatarsal declination angle (2MDA). Furthermore, the dislocation group was divided into 3 subgroups according to second toe deviation direction: group M (medial type), group N (neutral type), and group L (lateral type).

RESULTS

The IPA and the 2MDA were significantly greater in the study group than in the control group. By multiple comparison analysis, the IMA was greatest in group M and smallest in group L. The IPA was smaller and 2MDA greater in group N than in group L. The HVA and MAA in group L were greatest, and MPD in group L was smallest.

CONCLUSIONS

The patients with second MTP joint dislocation associated with hallux valgus had greater hallux interphalangeal joint varus and a second metatarsal more inclined than with hallux valgus alone. The second toe deviated in a different direction according to the foot shape.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Nonoperative Treatment of a Lesser Toe Plantar Plate Tear with Serial MRI Follow-up: A Case Report

With the current data concentrating on different operative treatment options for plantar plate tears, few data can be found on possible nonoperative treatment strategies for this entity and the specifics of such treatment. In the present case report, the successful nonoperative treatment of a patient with a rupture of the plantar plate in a lesser toe metatarsophalangeal joint is presented. The patient was followed up using repeat clinical examinations and high-resolution magnetic resonance imaging scans for 1 year after the imitation of therapy to provide information on the different stages of the healing process.

Cadaveric Evaluation of Dorsal Intermetatarsal Approach for Plantar Plate and Lateral Collateral Ligament Repair of the Lesser Metatarsophalangeal Joints

BACKGROUND

Access to the plantar plate has been described using either a plantar approach or an extensive dorsal approach that required complete joint destabilization and often a metatarsal osteotomy. Clinical scenarios related to plantar plate tear vary and the pathologies in early stages are frequently limited to unilateral soft tissue structures; a less invasive operative approach may be possible. A novel approach requiring a release of only the lateral collateral ligament and the lateral half of the plantar plate is presented in this cadaver model; the extent of joint exposure possible is described. The ability to place a secure suture through the lateral collateral ligament and the plantar plate was analyzed.

METHODS

Nine fresh-frozen cadaveric specimens were dissected in a randomized fashion across the second to fourth metatarsophalangeal joints through the intermetatarsal space dorsally. Under distraction, soft tissue was sequentially released, including dorsal capsule, lateral collateral ligament, and the lateral half of the plantar plate. Integrity of the extensor tendons, deep transverse intermetatarsal ligament, proximal attachment of the plantar plate, and osseous structures was carefully preserved. The joint exposure was quantified after each step with sizing rods. Using a suture passer, 2-0 nonabsorbable braided sutures were passed into the lateral collateral ligament and the plantar plate, and the construct strength was measured using a tensiometer.

RESULTS

Progressive increase in mean joint exposure was noted after each step of soft tissue release with the final exposure of 6 mm after release of the lateral half of the plantar plate. Joint exposures after a capsulotomy and a lateral collateral release were 3 mm and 4 mm, respectively. Under distraction, the unilateral release of soft tissue created a lateral opening of the joint while the proximal phalangeal base adducted and medially deviated. Successful suture passage was noted in all specimens that could sustain a minimum tension of 25 N without a catastrophic failure. There was no statistically significant correlation with age, sex, foot length, and rays of the specimens when joint exposure was considered.

CONCLUSION

The dorsal intermetatarsal approach appeared to be feasible for access to the lateral collateral ligament and the lateral half of the plantar plate. The average joint exposure of 6 mm allowed a quality suture passage by a suture passer in both structures in all specimens without the need of a metatarsal osteotomy.

CLINICAL RELEVANCE

This operative approach may be appropriate for early stages plantar plate tear when only lateral soft tissue repair is needed. This technique should not preclude conversion to a more extensile operative approach or an additional metatarsal osteotomy if needed. Applicability of this operative approach in cases with more advanced pathologies or involving only medial soft tissue structures requires further studies.

Association of Abnormal Metatarsal Parabola With Second Metatarsophalangeal Joint Plantar Plate Pathology

BACKGROUND

Plantar plate pathology is common, yet it is unclear whether, and to what extent, the length of the second metatarsal contributes to this problem.

METHODS

We conducted a retrospective case-control (1:2) study to examine radiographic risk factors for plantar plate tears. One hundred patients (age 55.7 ± 12.3 years) with plantar plate injuries and 200 healthy controls (age 56.3 ± 11.3 years) were included. Cases were defined as patients with nonacute, isolated, plantar plate pathology of the second metatarsophalangeal joint confirmed by intraoperative inspection at a single foot and ankle specialty practice from June 1, 2007, to January 31, 2014. Patients presenting for pain outside of the forefoot served as the control group. Controls were matched on age (±2 years), gender, and year of presentation. Weight-bearing foot x-rays were assessed for several predetermined angular relationships by a single rater. Conditional logistic regression was used to identify risk factors for plantar plate injury.

RESULTS

A long second metatarsal, defined as a metatarsal protrusion index less than -4 mm, was the only significant risk factor for plantar plate pathology in both the univariate and multivariable analyses (multivariate odds ratio 2.5 [95% confidence interval 1.8 to 3.3], P = .002).

CONCLUSION

We found that a long second metatarsal was a risk factor for developing second metatarsophalangeal joint plantar plate tears. This knowledge may aid foot and ankle surgeons when contemplating the need for second metatarsal shortening osteotomies (eg, Weil osteotomy) during plantar plate surgery and when deciding on the amount of shortening for second metatarsal osteotomies.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Plantar Plate Repair for Lesser Metatarsophalangeal Joint Instability

BACKGROUND

Lesser metatarsophalangeal (MTP) joint instability is a common cause of forefoot pain. Advances in operative technique and instrumentation have made it possible to anatomically treat plantar plate tears through a dorsal approach. Our goal was to evaluate the subjective, functional, and radiographic outcomes of plantar plate repair (PPR) from a dorsal approach.

METHODS

A prospective case series was performed evaluating the results of PPR in 97 feet with 138 plantar plate tears. Patients underwent PPR from a dorsal approach with a Weil osteotomy. We followed patients at regular intervals for 12 months and collected data preoperatively and postoperatively with respect to visual analog scale (VAS) scores, MTP range of motion (ROM), paper pull-out test, American Orthopaedic Foot & Ankle Society (AOFAS) scores, satisfaction, and radiographic measures.

RESULTS

Eighty percent of patients scored "good" to "excellent" satisfaction scores at 12 months. The mean VAS pain score preoperatively was 5.4/10, and postoperatively was 1.5/10. The mean AOFAS scores increased from 49 to 81 points following surgery. The mean MTP ROM preoperatively was 43 degrees and postoperatively 31 degrees. Forty-two percent of toes passed the paper pull out test prior to surgery and 54% at 12 months. Mean metatarsal shortening was 2.4/3.1/1.2 mm for the second, third, and fourth metatarsals, respectively. The mean MTP joint angles preoperatively were 2/4.9/-1.3 degrees and postoperatively were 7.4/9.6/0.2 degrees, respectively, for the second, third, and fourth MTP joints.

CONCLUSION

We found that the plantar plate could be repaired through a dorsal approach with reliable outcomes. PPR was a viable option to anatomically restore the ligamentous support in the unstable lesser MTP joint.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Metatarsalgia

The causes of metatarsalgia are classified as primary, secondary, and iatrogenic. Anatomical and biomechanical considerations separate "static" from "propulsive" forms of metatarsalgia. The physical examination should be combined with an assessment of weight-bearing radiographs and, if needed, of ultrasound or magnetic resonance imaging scans. The first-line treatment is conservative (stretching exercises, footwear modification, insoles, and lesion debridement). Soft-tissue surgical procedures (gastrocnemius muscle recession, tendon transfer, and plantar plate repair) should also be considered. Among the various types of metatarsal osteotomy, the Weil procedure is reliable. Percutaneous methods are being developed but require evaluation. A treatment algorithm can be developed based on whether the hallux is normal or abnormal. Metatarsalgia due to inflammatory disease requires a specific treatment strategy.

Metatarsophalangeal Hyperextension Movement Pattern Related to Diabetic Forefoot Deformity

BACKGROUND

Metatarsophalangeal joint (MTPJ) hyperextension deformity is common in people with diabetic neuropathy and a known risk factor for ulceration and amputation. An MTPJ hyperextension movement pattern may contribute to the development of this acquired deformity.

OBJECTIVE

The purpose of this study was to determine, in people with diabetes mellitus and peripheral neuropathy (DM+PN), the ankle and MTPJ ranges of motion that characterize an MTPJ hyperextension movement pattern and its relationship to MTPJ deformity severity. It was hypothesized that severity of MTPJ deformity would be related to limitations in maximum ankle dorsiflexion and increased MTPJ extension during active ankle dorsiflexion movement tasks.

DESIGN

A cross-sectional study design was used that included 34 people with DM+PN (mean age=59 years, SD=9).

METHODS

Computed tomography and 3-dimensional motion capture analysis were used to measure resting MTPJ angle and intersegmental foot motion during the tasks of ankle dorsiflexion and plantar flexion with the knee extended and flexed to 90 degrees, walking, and sit-to/from-stand.

RESULTS

The MTPJ extension movement pattern during all tasks was directly correlated with severity of MTPJ deformity: maximum ankle dorsiflexion with knee extended (r=.35; 95% confidence interval [CI]=.02, .62), with knee flexed (r=.35; 95% CI=0.01, 0.61), during the swing phase of gait (r=.47; 95% CI=0.16, 0.70), during standing up (r=.48; 95% CI=0.17, 0.71), and during sitting down (r=.38; 95% CI=0.05, 0.64). All correlations were statistically significant.

LIMITATIONS

This study was cross-sectional, and causal relationships cannot be made.

CONCLUSIONS

A hyperextension MTPJ movement pattern associated with limited ankle dorsiflexion has been characterized in people with diabetic neuropathy. Increased MTPJ extension during movement and functional tasks was correlated with severity of resting MTPJ alignment. Repetition of this movement pattern could be an important factor in the etiology of MTPJ deformity and future risk of ulceration.

How to classify plantar plate injuries: parameters from history and physical examination

Objective

To find the best clinical parameters for defining and classifying the degree of plantar plate injuries.

Method

Sixty-eight patients (100 metatarsophalangeal joints) were classified in accordance with the Arthroscopic Anatomical Classification for plantar plate injuries and were divided into five groups (0 to IV). Their medical files were reviewed and the incidence of each parameter for the respective group was correlated. These parameters were: use of high heels, sports, acute pain, local edema, Mulder's sign, widening of the interdigital space, pain in the head of the corresponding metatarsal, touching the ground, “drawer test”, toe grip and toe deformities (in the sagittal, coronal and transversal planes).

Results

There were no statistically significant associations between the degree of injury and use of high-heel shoes, sports trauma, pain at the head of the metatarsal, Mulder's sign, deformity in pronation or displacement in the transversal and sagittal planes (although their combination, i.e. “cross toe”, showed a statistically significant correlation). Positive correlations with the severity of the injuries were found in relation to initial acute pain, progressive widening of the interdigital space, loss of “touching the ground”, positive results from the “drawer test” on the metatarsophalangeal joint, diminished grip strength and toe deformity in supination.

Conclusions

The “drawer test” was seen to be the more reliable and precise tool for classifying the degree of plantar plate injury, followed by “touching the ground” and rotational deformities. It is possible to improve the precision of the diagnosis and the predictions of the anatomical classification for plantar plate injuries through combining the clinical history and data from the physical examination.

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.

Plantar plate radiofrequency and Weil osteotomy for subtle metatarsophalangeal joint instablity

Background

To the present day, literature has only discussed how to treat extensive plantar plate and collateral ligament lesions, with gross joint subluxation and obvious clinical instability. The treatment options for early stages of the disease with minor injuries and subtle instabilities have not been described. The main purpose of this prospective study is to evaluate the efficacy of the combination of the arthroscopic radiofrequency shrinkage and distal Weil osteotomy in the treatment of subtle metatarsophalangeal joint instability.

Method

Prospective data (clinical, radiological, and arthroscopic findings) of 19 patients, with a total of 35 slightly unstable joints, was collected. The physical examination defined the hypothesis for plantar plate lesions (grades 0 and 1), which was confirmed during the diagnostic step of the arthroscopic procedure.

Results

Among our patients, 73 % were females and 63 % reported wearing high heels. The average age was 59 years and post-operative follow-up was 20 months. In the initial sample frame, 62 % of joints showed spread-out toes with increased interdigital spacing. The mean American Orthopedic Foot and Ankle Society score rose from 53 points pre-operatively to 92 points post-operatively and a visual-analog pain scale average value of eight points pre-operatively decreased to zero post-operatively. During the pre-operative evaluation, none of the patients had stable joints and over 97 % were classified as having grade 1 instability (<50 % subluxation). After treatment, 83 % of the joints became stable (degree of instability 0) and over 97 % were congruent. All studied parameters showed statistically significant improvements in the post-operative period (p < 0.001) showing the efficiency of the treatment in pain relief, while restoring the joint stability and congruity.

Conclusion

Arthroscopic radiofrequency shrinkage in combination with distal Weil osteotomy promotes functional improvement, pain relief, and restores the joint stability in the plantar plate lesion grades 0 and 1.

Technique Tip: The Use of McGlamry Elevator to Assist Suture Passing in the Dorsal Technique of Plantar Plate Repair With Weil Osteotomy for Lesser Metatarsophalangeal Joint Instability

The combination of a dorsal approach to the plantar plate with a Weil's metatarsal osteotomy has been shown to provide an adequate exposure for plantar plate repair. However, soft tissues in a restricted area of the metatarsophalangeal joint could present as a technical difficulty during suture retrieval during repair of the plantar plate. The purpose of this article is to describe the use of the McGlamry elevator for assistance in the retrieval of sutures through the proximal phalanx.

LEVEL OF EVIDENCE

Level V: Expert opinion.

Prospective evaluation of protocol for surgical treatment of lesser MTP joint plantar plate tears

BACKGROUND

Instability of the lesser metatarsophalangeal (MTP) joints is a common cause of deformity and pain. The purpose of this study was to prospectively evaluate the surgical outcomes for the different grades of plantar plate tears and propose a treatment protocol.

METHODS

Sixty-eight patients (100 MTP joints) were prospectively enrolled and graded according to the anatomical grade system for plantar plate tears. Based on this classification, the appropriate surgical procedure was chosen as follows: grades 0 and I, thermal shrinkage with radiofrequency; grades II and III, direct reinsertion of the plantar plate; and grade IV, flexor-to-extensor tendon transfer. All surgical procedures were associated with a Weil metatarsal osteotomy. Evaluations were performed before and after surgical treatment with a mean follow-up of 2 years (12-36 months), using clinical and radiological parameters: American Orthopaedic Foot and Ankle Society (AOFAS) Lesser MTP-IF Scale, visual analog scale (VAS), ground touch, joint stability, and toe purchase.

RESULTS

The analysis of the clinical parameters demonstrated a significant improvement of all groups (P < .0001) after surgical treatment, but grade IV had less VAS improvement and a fair AOFAS average score (72 points). All groups improved regarding physical examination parameters, but grade I, III, and IV tears had proportionally less stable MTP joints following surgery, as well as a lower proportion of normal postoperative toe purchase and ground touch. All groups showed a significant improvement regarding radiographic parameters.

CONCLUSION

All groups of operatively treated patients had significant improvement with regard to subjective and objective parameters. Grades I, III, and IV presented inferior results compared with grades 0 and II.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Lesser metatarsal phalangeal joint arthroscopy: anatomic description and comparative dissection

PURPOSE

The aim of this article is to describe the normal arthroscopic anatomy of the lesser metatarsophalangeal (MTP) joints and compare it with that seen in open dissection in cadaveric models.

METHODS

We performed arthroscopic examination of 18 MTP joints of 6 normal fresh frozen feet. The second, third, and fourth MTP joints were studied because of the higher incidence of pathologic conditions found in these joints. During arthroscopy, each anatomic structure identified was named and marked with different colored sutures using straight suture needles. After the arthroscopic procedure of identification and marking, each MTP joint was dissected, and all the anatomic structures were grossly identified. With these data, the correlation between the arthroscopic and the direct visualization of a normal MTP joint was established.

RESULTS

Considering the joint regions, we found that the examination accuracy of the medial gutter was 91%, whereas the central joint accuracy reached 100% and the accuracy of the lateral gutter was 98%. The overall arthroscopic accuracy for the lesser MTP joints was 96%.

CONCLUSIONS

There is a high level of anatomic accuracy at the lesser MTP joint with arthroscopy.

CLINICAL RELEVANCE

The high overall level of anatomic accuracy of lesser MTP joint arthroscopy (96%) allows us to consider this resource as a valuable tool in the diagnosis and treatment of these joints, expanding the spectrum of indications using this method.