Microvasculature of the Plantar Plate Using Nano–Computed Tomography

Background: Lesser toe plantar plate attenuation or disruption is being increasingly implicated in a variety of common clinical conditions. A multitude of surgical techniques and devices have been recently developed to facilitate surgical repair of the plantar plate. However, the microvascular anatomy, and therefore the healing potential in large part, has not been defined. We investigated the microvasculature of the plantar plate by employing a novel technique involving microvascular perfusion and nano–computed tomography (nano-CT) imaging. Methods: Twelve human adult cadaveric lower extremities were amputated distal to the knee. The anterior and posterior tibial arteries were perfused with a barium solution. The soft tissues of each foot were then counterstained with phosphomolybdic acid (PMA). The second through fourth toe metatarsophalangeal (MTP) joints of 12 feet were imaged with nano-CT at 14-micron resolution. Images were then reconstructed for analysis of the plantar plate microvasculature and calculation of the vascular density along the length of the plantar plate. Results: A microvascular network extends from the surrounding soft tissues at the attachments of the plantar plate on both the metatarsal and proximal phalanx. The midsubstance of the plantar plate appears to be relatively hypovascular. Analysis of the vascular density along the length of the plantar plate demonstrated a consistent trend with increased vascular density at approximately the proximal 29% and distal 22% of the plantar plate. Conclusion: There is a vascular network extending from the surrounding soft tissues into the proximal and distal attachments of the plantar plate. Clinical relevance: The hypovascular midportion of the plantar plate may play an important role in the underlying pathoanatomy and pathophysiology of this area. These findings may have significant clinical implications for the reparative potential of this region and the surgical procedures currently described to accomplish anatomic plantar plate repair.

Download Full-text

Microvasculature of the Plantar Plate Using Nano-Computed Tomography

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00006 ◽

2018 ◽

Vol 3 (2) ◽

pp. 2473011418S0000

Author(s):

Fred Finney ◽

Jaron Scott ◽

Karl Jepsen ◽

James Holmes ◽

Paul Talusan

Keyword(s):

Computed Tomography ◽

Soft Tissues ◽

Proximal Phalanx ◽

Three Dimensional ◽

Surgical Techniques ◽

Phosphomolybdic Acid ◽

Vascular Density ◽

Plantar Plate ◽

Tibial Arteries ◽

Mtp Joints

Category: Basic Sciences/Biologics, Lesser Toes, Midfoot/Forefoot Introduction/Purpose: Lesser toe plantar plate attenuation or disruption is being increasingly implicated in a variety of very common clinical complaints including metatarsalgia, metatarsal-phalangeal (MTP) joint subluxation and dislocation, hammertoe, crossover toe, etc. A multitude of surgical techniques and devices have been recently developed to facilitate surgical repair of the plantar plate. However, the microvascular anatomy, and therefore the healing potential in large part, has not been addressed. We sought to answer this question by employing a novel technique involving microvascular perfusion and nano-computed tomography (Nano-CT) imaging. Methods: 12 human adult cadaveric lower extremities were amputated distal to the knee. The anterior and posterior tibial arteries were dissected and cannulated proximal to the ankle joint and were perfused with a barium solution. The soft tissues of each foot were then counterstained with phosphomolybdic acid (PMA). The 2nd through 4th toe MTP joints of 12 feet were imaged with Nano-CT at 14-micron resolution. Images were then reconstructed for three-dimensional analysis of the plantar plate microvasculature and calculation of the vascular density along the length of the plantar plate. Results: A microvascular network extends from the surrounding soft tissues at the attachments of the plantar plate on both the metatarsal and proximal phalanx. The mid-substance of the plantar plate appears to be relatively hypovascular. Analysis of the vascular density along the length of the plantar plate demonstrated a consistent trend with increased vascular density at approximately the proximal 30% and distal 20% of the plantar plate (Figure 1). Conclusion: There is a vascular network extending from the surrounding soft tissues into approximately the proximal 30% and the distal 20% of the plantar plate. The hypovascular mid-portion of the plantar plate may play an important role in the underlying patho-anatomy and pathophysiology of this area. We believe our findings likely have significant clinical implications for the reparative potential of this region, and therefore the surgical procedures currently described to accomplish anatomic plantar plate repair.

Download Full-text

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

Foot & Ankle International ◽

10.1177/1071100721990038 ◽

2021 ◽

pp. 107110072199003

Author(s):

Natalie V. Singer ◽

Noah E. Saunders ◽

James R. Holmes ◽

David M. Walton ◽

Fred T. Finney ◽

...

Keyword(s):

Soft Tissues ◽

Proximal Phalanx ◽

Surgical Techniques ◽

Phosphomolybdic Acid ◽

Ct Imaging ◽

Control Group ◽

Vascular Density ◽

Computed Tomographic ◽

Plantar Plate ◽

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.

Download Full-text

A Comparison of Microvasculature of Normal versus Torn Lesser Toe Metatarsophalangeal Joint Plantar Plates Using Nano-CT Imaging

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00450 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0045

Author(s):

Natalie Singer ◽

David M. Walton ◽

James R. Holmes ◽

Paul G. Talusan

Keyword(s):

Soft Tissues ◽

Proximal Phalanx ◽

Surgical Techniques ◽

Metatarsophalangeal Joint ◽

Phosphomolybdic Acid ◽

Ct Imaging ◽

Control Group ◽

Vascular Density ◽

Plantar Plate ◽

Plate Length

Category: Lesser Toes Introduction/Purpose: Recent surgical techniques have focused on anatomic repair of lesser toe metatarsophalangeal (MTP) plantar plate tears. MTP instability has been implicated in a number of common toe deformities as well as metatarsalgia. 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-CT imaging methods. Methods: Eight 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 8 feet were imaged. These images were then reconstructed, plantar plate tears were identified, and eleven toes remained. The plantar plate microvasculature for these eleven toes was analyzed and calculation of vascular density along the plantar plate was performed. Using ANOVA analysis 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. Results: Demonstrated in Figure 1, of the torn plantar plates the average percent vascular density (vascular volume/tissue volume) in the first quartile of length (proximal to distal) is 0.365 (SD 0.058) compared to 0.281 (SD 0.036) for intact plantar plates; in the second quartile it is 0.300 (SD 0.044) vs 0.175 (SD 0.025); third quartile it is 0.326 (SD 0.051) vs 0.117 (SD 0.015); and fourth (most distal) quartile is 0.600 (SD 0.183) vs 0.319 (SD 0.082) respectively. Using ANOVA testing all differences were found to be significant to p<0.001. Conclusion: Torn plantar plates demonstrate 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. 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.

Download Full-text

Angiology of the Plantar Plate

Foot & Ankle Orthopaedics ◽

10.1177/2473011417s000168 ◽

2017 ◽

Vol 2 (3) ◽

pp. 2473011417S0001

Author(s):

Fred Finney ◽

Basma Khoury ◽

Jaron Scott ◽

Ken Kozloff ◽

Todd Irwin ◽

...

Keyword(s):

Blood Supply ◽

Perfusion Imaging ◽

Surgical Techniques ◽

Vascular Supply ◽

Micro Ct ◽

Ct Scanner ◽

Micro Computed Tomography ◽

Surgical Interventions ◽

Plantar Plate ◽

Mtp Joints

Category: Basic Sciences/Biologics, Lesser Toes, Midfoot/Forefoot Introduction/Purpose: Hammertoes, crossover toes, and claw toes are common deformities and can be a major source of pain and dysfunction. These deformities result from instability of the metatarsophalangeal (MTP) joint due to incompetence of the plantar plate and/or collateral ligaments. Non-operative management is the first line of treatment. When non-operative treatment is unsuccessful, surgical interventions have been described. Newer surgical techniques focus on performing anatomic repairs of plantar plates. The vasculature of the foot has been well studied, but the vascular supply of the plantar plate has not been described. This study presents a new technique for imaging the microvasculature of the lesser toe plantar plates through micro- computed tomography (micro-CT) in order to better understand tear pathology and the capacity of healing with plantar plate repairs. Methods: The posterior tibial and dorsalis pedis arteries of a fresh frozen human cadaver foot were dissected and cannulated at the ankle for perfusion distally. After administration of an anticoagulant, each artery was perfused with Microfil® Silicone Rubber, a contrast agent. The compound was then allowed to cure, and the foot was fixed in formalin. The foot was sectioned through the metatarsal shafts for imaging, and imaging of the lesser toe MTP joints was performed using a Bruker Skyscan 1176 micro-CT scanner at 18 micron slices. Computerized reconstruction of the images was performed for three dimensional visualization of the vasculature. Results: Post-perfusion imaging of the lesser toe MTP joints using micro-CT allows for visualization of the plantar plate microvasculature. Preliminary imaging suggests that micro-CT is a useful modality for analysis of the blood supply of the plantar plate. Conclusion: Anatomic repair of the plantar plate has become a viable treatment option for MTP joint instability. One important question that remains to be answered is whether plantar plate tears have the capacity to heal. We present a novel technique for imaging of lesser toe plantar plate microvascularity using micro-CT. Preliminary results of post-perfusion imaging of the plantar plate are promising for developing a better understanding of its blood supply. Further definition of the plantar plate vascular supply will help clinicians understand the capacity for healing after repairs and may provide some insight to the biological causes plantar plate tears.

Download Full-text

Effect of McGlamry Elevator Placement on the Plantar Plate Origin

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00452 ◽

2018 ◽

Vol 3 (3) ◽

pp. 2473011418S0045

Author(s):

Natalie Singer ◽

Fred Finney ◽

Paul Talusan

Keyword(s):

Soft Tissues ◽

Surgical Techniques ◽

Collateral Ligaments ◽

Collateral Ligament ◽

Dorsal Approach ◽

Deep Placement ◽

Plantar Plate ◽

Significant Difference ◽

Fresh Frozen ◽

Relationship Of

Category: Lesser Toes Introduction/Purpose: Lesser metatarsal phalangeal (MTP) joint plantar plate tears have been implicated in a variety of lesser toe pathologies, and plantar plate repair (PPR) through a dorsal approach has become increasingly popular as a treatment of lesser toe deformities and lesser MTP instability. With the aid of a McGlamry elevator, releasing the collateral ligaments and micro-suture passing techniques, the plantar plate is repaired under direct visualization. While this approach is seen as a reliable alternative, the consequence of this technique on local MTP joint anatomy is not yet well understood. The purpose of this study is to describe the proximal plantar plate attachment and to quantify the amount of soft tissue disruption of the lesser toe MTP joint anatomy with insertion of a McGlamry elevator. Methods: Fresh frozen human cadaveric feet were dissected, and the proximal plantar plate attachment of the second, third, and fourth toe MTP joints (n=6) were examined, focusing on the relationship of structures connecting the distal metatarsal shaft and head to the plantar plate. The accessory collateral ligament insertions and proximal plantar plate attachments were measured using digital calipers. Next, the second, third, and fourth rays (n=12) of separate fresh frozen cadaveric specimens were isolated. An 11mm McGlamry elevator was then inserted in standard surgical fashion in both a more shallow (limited exposure) and deeper (greater exposure) position. Using mini C-arm fluoroscopy, radiographs were taken in both positions, and the depth of insertion along the metatarsal was measured. Results: The proximal plantar plate attachment to the metatarsal is most robust just proximal to the lateral articular margin and this attachment extends an average of 10.42mm (SD= 2.71mm) proximally along the metatarsal neck and shaft. In addition there are stout proximal plantar plate attachments at the bilateral insertion sites of the accessory collateral ligament (ACL) which are thick and broad with an average insertion length of 9.01mm (SD=1.35mm). Insertion of a McGlamry elevator resulted in stripping of the distal plantar soft tissues over an average of 21.58% of the total metatarsal length (SD=4.43%) for shallow placement and 34.87% (SD=4.40%) for deep placement with a significant difference of 7.96% between the two positions (p<.00001). Conclusion: Current techniques of plantar plate repair through a dorsal approach require releasing collateral ligaments and proximal stripping of the plantar plate from the metatarsal for adequate visualization. We suggest that this significantly destabilizes the metatarsal from the plantar plate as it strips approximately the distal most one third of the metatarsal including all major proximal plantar plate attachments to the metatarsal. As surgical techniques continue to evolve and improve, surgeons should consider avoiding the placement of a McGlamry elevator as this can destabilize the proximal attachment of the plantar plate to the metatarsal.

Download Full-text

Facial Feminization Surgery Review: Diagnosis, Preoperative Planning, Surgical Techniques, and Outcomes

FACE ◽

10.1177/27325016211057299 ◽

2021 ◽

pp. 273250162110572

Author(s):

Joshua Choe ◽

Sajni Parikh ◽

Sarah L. Barnett ◽

Sabrina Sam ◽

Kevin Chen ◽

...

Keyword(s):

Computed Tomography ◽

Patient Satisfaction ◽

Surgical Procedures ◽

Soft Tissues ◽

Preoperative Planning ◽

Surgical Techniques ◽

Facial Features ◽

Virtual Planning ◽

Objective Outcome ◽

Aesthetic Preferences

Facial Feminization Surgery (FFS) broadly encompasses a series of surgical procedures offered by craniomaxillofacial surgeons designed to modify facial features and transform both skeletal and soft tissues to create a more feminine appearance. Techniques, initially pioneered by Dr. Douglas Ousterhout, have been modified to include preoperative virtual planning and evolving aesthetic preferences. Computed Tomography (CT) imaging assists with morphologic typing of the brow, supraorbital, chin, and lateral mandible regions. Advancements in instrumentation increase the efficiency and accuracy of FFS procedures. More recently, trends in transgender acceptance have led to improved insurance authorization for FFS procedures. Objective outcome studies have shown success in achieving goals of (1) minimizing mis-gendering in public (appropriately identifying trans-women as female) and (2) reduction in dysphoric feelings (improved patient satisfaction).

Download Full-text

Cross-sectional anatomy, computed tomography, and magnetic resonance imaging of the banded houndshark (Triakis scyllium)

Scientific Reports ◽

10.1038/s41598-020-80823-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sang Wha Kim ◽

Adams Hei Long Yuen ◽

Cherry Tsz Ching Poon ◽

Joon Oh Hwang ◽

Chang Jun Lee ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Computed Tomography ◽

Magnetic Resonance ◽

Soft Tissues ◽

Imaging Techniques ◽

Evolutionary Developmental Biology ◽

Phylogenetic Position ◽

Ct Scanner ◽

Resonance Imaging ◽

Cross Sectional

AbstractDue to their important phylogenetic position among extant vertebrates, sharks are an invaluable group in evolutionary developmental biology studies. A thorough understanding of shark anatomy is essential to facilitate these studies and documentation of this iconic taxon. With the increasing availability of cross-sectional imaging techniques, the complicated anatomy of both cartilaginous and soft tissues can be analyzed non-invasively, quickly, and accurately. The aim of this study is to provide a detailed anatomical description of the normal banded houndshark (Triakis scyllium) using computed tomography (CT) and magnetic resonance imaging (MRI) along with cryosection images. Three banded houndsharks were scanned using a 64-detector row spiral CT scanner and a 3 T MRI scanner. All images were digitally stored and assessed using open-source Digital Imaging and Communications in Medicine viewer software in the transverse, sagittal, and dorsal dimensions. The banded houndshark cadavers were then cryosectioned at approximately 1-cm intervals. Corresponding transverse cryosection images were chosen to identify the best anatomical correlations for transverse CT and MRI images. The resulting images provided excellent detail of the major anatomical structures of the banded houndshark. The illustrations in the present study could be considered as a useful reference for interpretation of normal and pathological imaging studies of sharks.

Download Full-text