First Metatarsophalangeal Joint Motion in Homo sapiens

2012 ◽  
Vol 102 (5) ◽  
pp. 374-389 ◽  
Author(s):  
Michael N. Durrant ◽  
Tucker McElroy ◽  
Lara Durrant

Background: The metatarsal head and proximal phalanx exhibit considerable asymmetry in their shape and geometry, but there is little documentation in the literature regarding the prevalence of structural characteristics that occur in a given population. Although there is a considerable volume of in vivo and in vitro experiments demonstrating first metatarsal inversion around its longitudinal axis with dorsiflexion, little is known regarding the applicability of specific morphometrics to these motions. Methods: Nine distinctive osseous characteristics in the metatarsal head and phalanx were selected based on their location, geometry, and perceived functional relationship to previous studies describing metatarsal motion as inversion with dorsiflexion. The prevalences of the chosen characteristics were determined in a cohort of 21 randomly selected skeletal specimens, 19 of which were provided by the anatomical preparation office at the University of California, San Diego, and two of which were in the possession of one of us (M.D.). Results: The frequency of occurrence of each selected morphological characteristic in this sample and the relevant summary statistics confirm a strong association between the selected features and a conceptual two-axis kinematic model of the metatarsophalangeal joint. Conclusions: The selected morphometrics are consistent with inversion of the metatarsal around its longitudinal axis as it dorsiflexes. (J Am Podiatr Med Assoc 102(5): 374–389, 2012)

1997 ◽  
Vol 18 (12) ◽  
pp. 803-808 ◽  
Author(s):  
William A. Heller ◽  
Michael E. Brage

Our purpose in this study was to determine the effects of cheilectomy on the mechanics of dorsiflexion of the first metatarsophalangeal (MTP) joint. Ten fresh-frozen cadaver feet were utilized, of which two demonstrated radiographic evidence of hallux rigidus. Each specimen was rigidly mounted on a custom-made slide tray that was articulated with a hinge mechanism designed to dorsiflex the first MTP joint. Range-of-motion measurements were made on the first MTP joint. Cheilectomy of 30% of the metatarsal head diameter was performed. Lateral radiographs with the beam centered on the MTP joint were taken with the joint at neutral, 20°, 40°, and at the limits of dorsiflexion. This process was repeated after a 50% cheilectomy was performed. The radiographs were examined for changes in joint congruence and in patterns of surface motion as the hallux moved from neutral to full dorsiflexion. Instant centers of rotation were determined by a method first described by Rouleaux. We constructed surface velocity vectors to describe patterns of motion of the first MTP joint. The mean dorsiflexion of the first MTP joint was 67.9° and increased to 78.3° after 30% cheilectomy. The increase in dorsiflexion was significantly greater in the two specimens with hallux rigidus (33%) than in the other specimens (12.1%). After both levels of cheilectomy, the proximal phalanx demonstrated pivoting at the resection site on the metatarsal head. This pivoting resulted in abnormal motion patterns across the MTP joint. Normal sliding motion predominated in early dorsiflexion, with compression peaking at the end stage of dorsiflexion, producing jamming of the articular surfaces. Cheilectomy significantly increased dorsiflexion of the MTP joint, but resulted in abnormal motion patterns. The increase in dorsiflexion resulted from pivoting of the proximal phalanx on the metatarsal head, resulting in anomalous velocity vectors and compression across the MTP joint.


2014 ◽  
Vol 7 (2) ◽  
pp. 108-112 ◽  
Author(s):  
Douglas E. Lucas ◽  
Terrence Philbin ◽  
Safet Hatic

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


Foot & Ankle ◽  
1992 ◽  
Vol 13 (7) ◽  
pp. 391-395 ◽  
Author(s):  
Jonathan T. Deland ◽  
Mark Sobel ◽  
Steven P. Arnoczky ◽  
Francesca M. Thompson

Anatomic reconstruction of the collateral ligaments of the lesser metatarsophalangeal joints is proposed for certain cases of metatarsophalangeal instability. The suggested reconstruction involves replication of the attachments of the collateral ligaments. As an example of such a reconstruction, the interosseous tendon was used in this study as a graft for anatomic replacement of the collateral ligaments. The tendon was left attached distally where its attachments include the volar plate and proximal phalanx, thereby resembling the distal attachment of the collateral ligament. The proximal portion of the tendon was inserted into the metatarsal head, replicating the attachment of the collateral ligament at that location. Preliminary testing of such a reconstruction shows that it can re-establish stability caused by loss of the collateral ligaments. Such a procedure may be applicable in select cases of crossover toe deformity and straight vertical instability.


2008 ◽  
Vol 98 (4) ◽  
pp. 326-329 ◽  
Author(s):  
Ricardo Becerro de Bengoa Vallejo ◽  
Marta Elena Losa Iglesias ◽  
Fermin Viejo Tirado ◽  
Juan Carlos Prados Frutos ◽  
Kevin T. Jules

We describe a simplified capsular interpositional technique for the Keller bunionectomy that uses a Kirschner wire to interpose the capsule into the first metatarsophalangeal joint without requiring sutures. The capsule acts as a biologic spacer in the first metatarsophalangeal joint, allowing for fibrosis to fill the void created, with the Kirschner wire maintaining the distance between the metatarsal head and the stump of the proximal phalanx. This creation of a nonpainful pseudarthrosis prevents shortening of the hallux and retraction of the base of the proximal phalanx on the metatarsal head.


Foot & Ankle ◽  
1986 ◽  
Vol 7 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Alan Sykes ◽  
Angus W. Hughes

Arthrodesis of the first metatarsophalangeal joint of 15 pairs of cadaveric big toes were performed. The arthrodesis site was shaped with either a dome and socket or planar surface contact between the metatarsal head and proximal phalanx. A template was used to standardize the position of arthrodesis in 20° of valgus and 20° dorsiflexion. Various fixation devices were used to hold this position in corresponding pairs of specimens, and these fixation devices were tested to determine their relative effectiveness to prevent displacement on loading. Force-deflection curves were obtained for the various techniques tested, and by comparing these curves, the stability of the metatarsophalangeal arthrodesis site was found to be maintained most effectively using the cancellous screw fixation device with planar metatarsophalangeal surfaces.


Author(s):  
Christopher Viney

Light microscopy is a convenient technique for characterizing molecular order in fluid liquid crystalline materials. Microstructures can usually be observed under the actual conditions that promote the formation of liquid crystalline phases, whether or not a solvent is required, and at temperatures that can range from the boiling point of nitrogen to 600°C. It is relatively easy to produce specimens that are sufficiently thin and flat, simply by confining a droplet between glass cover slides. Specimens do not need to be conducting, and they do not have to be maintained in a vacuum. Drybox or other controlled environmental conditions can be maintained in a sealed chamber equipped with transparent windows; some heating/ freezing stages can be used for this purpose. It is relatively easy to construct a modified stage so that the generation and relaxation of global molecular order can be observed while specimens are being sheared, simulating flow conditions that exist during processing. Also, light only rarely affects the chemical composition or molecular weight distribution of the sample. Because little or no processing is required after collecting the sample, one can be confident that biologically derived materials will reveal many of their in vivo structural characteristics, even though microscopy is performed in vitro.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1441
Author(s):  
Yangpeng Lu ◽  
Yanan Jia ◽  
Zihan Xue ◽  
Nannan Li ◽  
Junyu Liu ◽  
...  

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.


1997 ◽  
Vol 18 (3) ◽  
pp. 119-127 ◽  
Author(s):  
Hans-Jörg Trnka ◽  
Alexander Zembsch ◽  
Hermann Wiesauer ◽  
Marc Hungerford ◽  
Martin Salzer ◽  
...  

The Austin osteotomy is a widely accepted method for correction of mild and moderate hallux valgus. In view of publications by Kitaoka et al. in 1991 and by Mann and colleagues, a more radical lateral soft tissue procedure was added to the originally described procedure. From September 1992 to January 1994, 85 patients underwent an Austin osteotomy combined with a lateral soft tissue procedure to correct their hallux valgus deformities. Seventy-nine patients (94 feet) were available for follow-up. The average patient age at the time of the operation was 47.1 years, and the average follow-up was 16.2 months. The average preoperative intermetatarsal angle was 13.9°, and the average hallux valgus angle was 29.7°. After surgery, the feet were corrected to an average intermetatarsal angle of 5.8° and an average hallux valgus angle of 11.9°. Sesamoid position was corrected from 2.1 before surgery to 0.5 after surgery. The results were also graded according to the Hallux Metatarsophalangeal Interphalangeal Score, and the functional and cosmetic outcomes were graded by the patient. Dissection of the plantar transverse ligament and release of the lateral capsule repositioned the tibial sesamoid and restored the biomechanics around the first metatarsophalangeal joint. There was no increased incidence of avascular necrosis of the first metatarsal head compared with the original technique.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1357
Author(s):  
Andreea-Mariana Negrescu ◽  
Anisoara Cimpean

The critical role of the immune system in host defense against foreign bodies and pathogens has been long recognized. With the introduction of a new field of research called osteoimmunology, the crosstalk between the immune and bone-forming cells has been studied more thoroughly, leading to the conclusion that the two systems are intimately connected through various cytokines, signaling molecules, transcription factors and receptors. The host immune reaction triggered by biomaterial implantation determines the in vivo fate of the implant, either in new bone formation or in fibrous tissue encapsulation. The traditional biomaterial design consisted in fabricating inert biomaterials capable of stimulating osteogenesis; however, inconsistencies between the in vitro and in vivo results were reported. This led to a shift in the development of biomaterials towards implants with osteoimmunomodulatory properties. By endowing the orthopedic biomaterials with favorable osteoimmunomodulatory properties, a desired immune response can be triggered in order to obtain a proper bone regeneration process. In this context, various approaches, such as the modification of chemical/structural characteristics or the incorporation of bioactive molecules, have been employed in order to modulate the crosstalk with the immune cells. The current review provides an overview of recent developments in such applied strategies.


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