Deep Ligament Research Articles

Ulnar footprints of the distal radioulnar ligaments: a detailed topographical study in 21 cadaveric wrists.

Understanding of the exact topography of the distal radioulnar ligaments insertions remains limited. An anatomical study was performed in 21 fresh frozen cadaveric wrists, where the superficial and deep ligaments were sequentially transected sharply at their ulnar insertions. The relationships between the distal radioulnar ligament footprints relative to the bony landmarks of the ulnar styloid were digitized. Our study demonstrated that in the coronal plane, the superficial distal radioulnar ligaments inserted at an average of 87% of the styloid height proximally to the styloid tip distally. The deep distal radioulnar ligaments inserted at an average of 81% of the styloid height distally to the fovea proximally. The superficial footprint had an area of 10.6 mm2 on the ulnar styloid. The deep distal radioulnar ligaments attachment was asymmetric and generally had two separate footprints. This study adds important topographical knowledge about the footprint of the distal radioulnar ligaments and may contribute to understanding the consequences of ulnar styloid fractures and distal radioulnar ligaments lesions.

The preliminary outcomes of percutaneously looped thread transection in the surgical treatment of carpal tunnel syndrome

Objective To study the preliminary effects of percutaneously looped thread transection on the surgical treatment of carpal tunnel syndrome (CTS). Methods A total of 72 cases (103 sides) were treated from January 2012 to December 2014 (27 males and 45 females, aged 22-94 years, with an average of 51.3 years). Among all the cases, 21 cases (30 sides) were treated with open decompression and 51 cases (73 sides) were treated with percutaneously looped thread transection. We did the incision in the ulnaris hypothenar pattern, revealed and cut off the transverse carpal ligament to decompress the carpal tunnel in the open surgery. Percutaneously looped thread transection was under the guidance of ultrasound, threading from the deep and shallow transverse carpal ligament, respectively, forming loops to cut off and decompressed the carpal tunnel. We observed the median nerve aspect ratio (the ratio of length to width of the uncinatum median nerve on transverse section) and swelling ratio (the ratio of area of median nerve on transverse section of pisiform and distal radius) under ultrasound before, during and 3 months after operation. Telephone follow-up was conducted in postoperative 3 months according to the Boston Carpal Tunnel Questionnaire (BCTQ) to evaluate the symptoms of carpal tunnel syndrome and wrist joint function. Results There were 11 cases lost in the follow-up, and 61 cases were followed up for 3 to 27 months, with an average of 11.6 months. The preoperative BCTQ scores of open decompression group and looped thread transection group were 28.5±4.6 and 29.4±5.3, respectively. There was no statistically significant difference between two groups (t=1.34, P=0.528). The postoperative 3 months BCTQ scores were 16.3±5.7 and 15.7±4.9. There was no statistically significant difference between two groups (t=1.12, P=0.674). The median nerve aspect ratios measured under ultrasound of open decompression group before and 3 months after operation were 3.8±0.7 and 2.6±0.4, respectively. The swelling ratios were 2.3±0.4 and 1.2±0.3. The difference of preoperative and postoperative changes was statistically significant (P< 0.05). The median nerve aspect ratios measured under ultrasound of looped thread transection group before and 3 months after operation were 3.9±0.6 and 2.7±0.5, respectively. The swelling ratios were 2.1±0.3 and 1.4±0.4. The difference of preoperative and postoperative changes was statistically significant (P<0.05). There were no infection, poor healing, blood vessel and nerve damage after operation in both two groups. Conclusion Percutaneously looped thread transaction under ultrasound for the surgical treatment of CTS has less trauma and rapid recovery. It can improve the symptoms of median nerve stimulation, restore the morphology and function of the median nerve and reach the same effects as the open decompression surgery. Key words: Carpal tunnel syndrome; Surgical procedures, minimally invasive; Ultrasonography; Decompression, surgical

How does wrist position affect the length of the distal radioulnar ligament: a three-dimensional image study in vivo?

This study was designed to investigate the length changes of the distal radioulnar ligament at different wrist positions and to determine the effect of hyperextension on the distal radioulnar ligament and to find out the most vulnerable position where the distal radioulnar ligament rupture and foveal avulsion. We obtained computed tomography scans of the wrists for 12 volunteers including two groups: hyperextension group and hyperextension with maximal rotation group. The images were reconstructed to the three-dimensional bone structures with customized software. The four portions of the distal radioulnar ligament were measured and analyzed statistically. No significant differences were noted in the lengths of the each portion of the distal radioulnar ligament among neutral position, wrist hyperextension, and hyper-radial extension. From neutral position to hyperextension with maximal pronation, the lengths of the palmar superficial radioulnar ligament (psRU) and dorsal deep radioulnar ligament (ddRU) decreased significantly, whereas the dorsal superficial radioulnar ligaments (dsRU) and palmar deep radioulnar ligament (pdRU) increased significantly. From neutral position to hyperextension with maximal supination, the lengths of the pdRU and dsRU ligaments decreased significantly, and the lengths of psRU and ddRU ligaments changed little. The factor of hyperextension has little effect on the length of the distal radioulnar ligament and the distal radioulnar ligament may be under great tension at the position of hyperextension with maximal pronation. These findings can provide more information to understand the pathomechanics of the triangular fibrocartilage complex injury caused by a fall on the outstretched hand and can provide information relevant to the distal radioulnar ligament restoration.

Deltoid Ligament and Tibiofibular Syndesmosis Injury in Chronic Lateral Ankle Instability: Magnetic Resonance Imaging Evaluation at 3T and Comparison with Arthroscopy.

ObjectiveTo evaluate the prevalence of deltoid ligament and distal tibiofibular syndesmosis injury on 3T magnetic resonance imaging (MRI) in patients with chronic lateral ankle instability (CLAI).Materials and MethodsFifty patients (mean age, 35 years) who had undergone preoperative 3T MRI and surgical treatment for CLAI were enrolled. The prevalence of deltoid ligament and syndesmosis injury were assessed. The complexity of lateral collateral ligament complex (LCLC) injury was correlated with prevalence of deltoid or syndesmosis injuries. The diagnostic accuracy of ankle ligament imaging at 3T MRI was analyzed using arthroscopy as a reference standard.ResultsOn MRI, deltoid ligament injury was identified in 18 (36%) patients as follows: superficial ligament alone, 9 (50%); deep ligament alone 2 (11%); and both ligaments 7 (39%). Syndesmosis abnormality was found in 21 (42%) patients as follows: anterior inferior tibiofibular ligament (AITFL) alone, 19 (90%); and AITFL and interosseous ligament, 2 (10%). There was no correlation between LCLC injury complexity and the prevalence of an accompanying deltoid or syndesmosis injury on both MRI and arthroscopic findings. MRI sensitivity and specificity for detection of deltoid ligament injury were 84% and 93.5%, and those for detection of syndesmosis injury were 91% and 100%, respectively.ConclusionDeltoid ligament or syndesmosis injuries were common in patients undergoing surgery for CLAI, regardless of the LCLC injury complexity. 3T MRI is helpful for the detection of all types of ankle ligament injury. Therefore, careful interpretation of pre-operative MRI is essential.

A new type of stalk articulation in the sea lily genus Vityazicrinus (Echinodermata, Crinoidea) and its ontogeny

A new stalk articulation named pseudo-synarthry is here described from the mesistele of Vityazicrinus petrachenkoi, a rare deep-sea crinoid from the Central Pacific Ocean. Pseudo-synarthries have an articulation facet displaying a general structure closely resembling the morphology of the true synarthry, i.e., with a strong bilateral symmetry and deep ligament depressions. Pseudo-synarthries differ from synarthries in lacking a hinge-like fulcral ridge and developing two additional depressions bordered by prominent crescent ridges at opposite sides of the bilateral symmetry axis. Pseudo-synarthries develop in the mesistele below a proxistele articulated by symplexies of 6–8 crenular units. Distally, subsidiary radial ridges appear on the outer edge of ligamentary depressions and tend to multiply, transforming pseudo-synarthries into multiradiate syzygies, as previously observed in the genus Guillecrinus. A chaotic polymeric pattern locally appears in the proxistele and mesistele, which tends to develop into a holomeric pattern during growth, devoid of any visible trace of ossicle fusion. Both early columnal ontogeny in comatulid larvae and the transition from a polymeric to a holomeric pattern in the guillecrinid stalk lead to the rejection of the hypothesis that the monomeric columnal results from the fusion of pre-existing ossicles. Among Guillecrinidae, pseudo-synarthries constitute derived characters that are unique to the Vityazicrinus mesistele. The development of radial subsidiary ridges in the distal stalk corresponds to a synapomorphy shared by Vityazicrinus and Guillecrinus, the two only genera currently attributed to this family. Pseudo-synarthries in Vityazicrinus appear as advanced stalk articulations adapted to the deep-sea environment, which are unknown from the fossil record.

Deltoid ligament in acute ankle injury: MR imaging analysis

To identify the pattern of deltoid ligament injury after acute ankle injury and the relationship between ankle fracture and deltoid ligament tear by magnetic resonance imaging (MRI). Thirty-six patients (32 male, and 4 female; mean age, 29.8years) with acute deltoid ligament injury who had undergone MRI participated in this study. The deltoid ligament was classified as having 3 superficial and 2 deep components. An image analysis included the integrity and tear site of the deltoid ligament, and other associated injuries. Association between ankle fracture and deltoid ligament tear was assessed using Fisher's exact test (P < 0.05). Of the 36 patients, 21 (58.3%) had tears in the superficial and deep deltoid ligaments, 6 (16.7%) in the superficial ligaments only, and 4 (11.1%) in the deep ligaments only. The most common tear site of the three components of the superficial deltoid and deep anterior tibiotalar ligaments was their proximal attachments (94% and 91.7% respectively), and that of the deep posterior tibiotalar ligament (pTTL) was its distal attachment (82.6%). The common associated injuries were ankle fracture (63.9%), syndesmosis tear (55.6%), and lateral collateral ligament complex tear (44.4%). All the components of the deltoid ligament were frequently torn in patients with ankle fractures (tibionavicular ligament, P = 0.009). The observed injury pattern of the deltoid ligament was complex and frequently associated with concomitant ankle pathology. The most common tear site of the superficial deltoid ligament was the medial malleolar attachment, whereas that of the deep pTTL was near its medial talar insertion.

REMODELING OF DISTAL ULNA AFTER EXCISION ARTHROPLASTY FOR ACUTE COMMINUTED DISTAL ULNAR FRACTURE: A CASE REPORT

Bone adaptation after excision arthroplasty of distal radioulnar joint in an acute traumatic distal ulna fracture has never been reported. A case of irreparable and comminuted distal ulnar head fracture was managed by excising the ulna head and repairing the fovea (deep ligament) attachments of distal radioulnar ligaments, and then an unexpected remodeling of the distal ulna with the shape of pole and seat was noted. The anatomy of deep fibers of distal radioulnar ligament is important not only in biomechanics about the stability of distal radioulnar joint but it is also possible in the morphology about the shape of the distal radioulnar joint.

Effect of toe and heel elevation on calculated tendon strains in the horse and the influence of the proximal interphalangeal joint

The sagittal alteration of hoof balance is a common intervention in horses, with corrective shoeing being one of the most frequently applied methods of managing tendonitis. However, the effect of toe or heel elevation on tendon strains is poorly understood. This study aimed to examine the effect of toe and heel wedges on the superficial digital flexor tendon, deep digital flexor tendon, and the third interosseous muscle or suspensory ligament strains using in vivo data and an accurate subject-specific model. Kinematic data were recorded using invasive markers at the walk and trot. Computerized tomography was then used to create a subject-specific model of an equine distal forelimb and strains were calculated for the superficial digital flexor tendon, the deep digital flexor tendon accessory ligament and the suspensory ligament for seven trials each of normal shoes, and toe and heel elevation. As the proximal interphalangeal joint is often ignored in strain calculations, its influence on the strain calculations was also tested. The deep ligament showed the same results for walk and trot with the heel wedge decreasing peak strain and the toe wedge increasing it. The opposite results were seen in the suspensory ligament and the superficial digital flexor tendon with the heel wedge increasing peak strain and the toe wedge decreasing it. The proximal interphalangeal joint was shown to be influential on the strains calculated with normal shoes and the calculated effect of the wedges. Our results imply that corrective shoeing appears to decrease strain in the tendon being targeted; the possibility of increases in strain in other structures should also be considered.

THE CLASSIC: Surgical Treatment of Fresh Injuries to the Major Ligaments of the Knee

THE CLASSIC: Surgical Treatment of Fresh Injuries to the Major Ligaments of the Knee

Laparoscopic vaginal vault suspension and enterocele repair

The anatomical goal in the treatment of vaginal vault prolapse is basically bto correct the deviated vaginal axis and to provide normal vaginal lengthQ [1]. In this retrospective study, laparoscopic deep uterosacral ligament suspension technique for treating vaginal vault prolapse and enterocele together with its effectiveness in maintaining normal anatomy has been investigated. Of the 17 patients who underwent operations, 6 and 11 had stage IIIc, and IVc prolapse, respectively, according to the Pelvic Organ Prolapse Quantitation.

Environmental control versus phylogenic fingerprint in ontogeny: The example of the development of the stalk in the genus Guillecrinus (stalked crinoids, Echinodermata)

The stalk morphology of the deep‐sea stalked crinoid Guillecrinus changes a lot from juvenile to adult. As a result of its unusual morphology among the extant crinoids, its taxonomic and phylogenetic affinities remain unsettled. Distinctive morphological changes characterize the various growth stages in stalked crinoids. We conduct and discuss a detailed ontogenetic analysis of the stalk of the two species (Guillecrinus neocaledonicus and G. reunionensis) of this Indo‐Pacific genus, which was observed in its environment during submersible dives off New Caledonia. Analyses examined (1) morphological changes, (2) the degree of change in morphology, (3) architectural constraints, and (4) the functional constraints related to environmental factors. The relations between three levels of integration were examined: the ossicle (columnal), the stalk, and the complete individual. The changes in level of organization were estimated. The analysis reveals that the external stalk morphology of Guillecrinus goes from a pronounced xenomorphic type in juveniles, characterized by diversified columnal articulations, which provide the proximal and distal part of the stalk with a considerable degree of flexibility, to a dominant homeomorphic type in adults, characterized by columnal articulations which allow little or no movement. This ontogenetic change through a mosaic of heterochronic developments corresponds with a change in the hydrodynamic environment, from a turbulent to a laminar water flow, and from nutritional contraints. The extensive development of deep ligament fossae in adults and in the distal stalk of juveniles corresponds to a relatively low allocation of energy to the skeleton, rather than a functional necessity. Proximal columnals in juvenile Guillecrinus display characteristics of adult Hyocrinidae. Distal columnals exhibit the typical morphology observed in Bourgueticrinina. Juveniles stages of both proximal and distal columnals show a high degree of specialization (derived characters). Well‐supported classifications have typically placed the Bourgueticrinina and the Hyocrinidae in two very dissimilar groups. Specific characteristics from the three very different families Bathycrinidae, Guillecrinidae and Hyocrinidae appear to be expressed either separately (Hyocrinus or Bathycrinus) or together (Guillecrinus). Their expression appears to depend on functional and environmental constraints. The transformation of columnals from juvenile to adult shows the important role of hypermorphic processes. However, no evidence of phylogenetic recapitulation was observed. Does the evidence presented here support or disprove current taxonomic interrelationships? How does morphology relate to ontogeny? Is heterochrony involved?

Is Posttraumatic First Web Contracture Avoidable? Prophylactic Guidelines and Treatment-Oriented Classification

The first web is a complex, multilayered anatomic region spanning the first and second metacarpals. It has a triangular shape, with its vertex located at the base of the first and second metacarpals; the skin web that joins the metacarpophalangeal joints of the index finger and thumb corresponds to its base. It is covered by glabrous skin on the palmar side and minimally hairy skin on the dorsum. It harbors the radial extension of the superficial palmar (natatory and transverse) and deep ligaments and the bellies of the adductor pollicis and first dorsal interosseous muscles with their investing fascia. The radial artery deepens from dorsal to palmar at its most proximal aspect. Suppleness and strength are the main characteristics of the web and can be highlighted during grasping and pinching. In grasping, the web has to be supple to allow maximal opening of the thumb for grabbing large objects. Once the object is held, power is needed to keep it in the hand; the muscles of the web are responsible for 80 percent of pinch strength.1 First web contracture is common after trauma to the hand, particularly the radial part, and has a tremendous negative effect on hand function. Even minor contractures will limit the ability to grab large objects. Because of its triangular shape, small limitations of aperture at its base have a major effect on the extremes of the triangle (the thumb and index pulps). First web contracture is an ongoing process, and the amount of time elapsed since the injury, independent of the severity, worsens the prognosis in two ways. First and more important, the web reduction initially is elastic (or reversible) but soon becomes irreversibly fixed (except with an operation). Second, there is a phenomenon of progressive involvement of formerly healthy layers2–4 in such a way that the problem may start in one structure (e.g., deficient skin) but in time it becomes widespread on the web (i.e., affects muscle, fascia, ligaments). The surgeon will have to divide structures that were formerly healthy and functional to open the web. Much of the interest has been focused on the surgical treatment of fixed first web contracture. In those articles, systematic release of skin, fascia, muscles from their origins or insertions, and trapeziometacarpal ligaments and even resection of the trapezium itself are recommended for the sake of placing the thumb in an abducted position,2–14 and several types of flaps have been presented to cover the resulting defect.15–21 Regrettably, it has been our experience that although an operation can restore the span of the web, the function of the web (e.g., pinch strength, allowance of thumb pronation, pinch dexterity) often will never be restored. Most of us have been educated as if first web contracture were an unavoidable bad companion (collateral damage) of some forms of trauma to the hand, and the surgeon’s role was limited to releasing the contracture. Taking into account the fact that once established, the damage is irreversible, we challenged this passive attitude more than 10 years ago and set the hypothesis that fixed first web contracture could be prevented. In this editorial, we

Incidence of Associated Knee Lesions with Torn Anterior Cruciate Ligament: Retrospective Cohort Assessment

The records of 141 consecutive patients with confirmed complete anterior cruciate ligament injuries were reviewed retrospectively. One hundred and sixty-two associated injuries were divided into 25 injury complexes. Isolated injuries to the anterior cruciate ligament occurred in 40 cases (28.4%). Injuries of the medial meniscus occurred in 62 cases (38.2%), while injuries of the lateral meniscus occurred in 37 cases (22.8%). Injuries to the medial collateral ligament complex occurred in 42 cases (25.9%). Injuries to the lateral collateral ligament, posterior deep popliteus-arcuate ligament complex, and posterior cruciate ligament were found to be positively correlated (rho = .81, p = .001, and rho = .77, p = .001, N = 141, respectively). Injuries to the medial collateral ligament and the posterior oblique ligament were likewise positively correlated (rho = .45, p = .001, N = 141).

Normal patellar retinaculum: MR and sonographic imaging with cadaveric correlation.

The purpose of our study was to define retinacular anatomy with MR imaging and sonography. Five cadaveric knee specimens underwent sonography and MR imaging using the following sequences: T1-weighted axial, sagittal, coronal, and five oblique planes and axial three-dimensional gradient-echo imaging. Three knees were injected with gelatin gadolinium solution before imaging. All five specimens were sectioned. Correlation was made between findings derived from MR imaging, sonography, and cadaveric sections. T1-weighted axial images without intraarticular gadolinium were most useful for revealing the superficial layer and deep ligaments of the retinacula; however, the oblique sagittal and oblique coronal planes showed the deep ligaments more clearly in their craniocaudal dimensions. Sonography revealed the retinacula as bilaminar structures with discrete superficial and deep layers but failed to distinguish the deep ligaments from one another. Conventional T1-weighted axial MR images showed the various components of the retinacula including the medial patellofemoral ligament, which is an important stabilizing structure. Oblique imaging planes may be a helpful adjunct to axial imaging planes. Sonography can consistently identify the retinacula and may be useful in their assessment.

The capitohamate ligaments: A comparison of biomechanical properties

The physical attributes of the three capitohamate interosseous ligaments were tested in a computer-controlled multi-axis testing machine using 12 human cadaver specimens. After an intact test run, selected ligaments were cut in random sequence and the test repeated. The remaining ligaments were tested to failure with servohydrolic stress at 5 mm/second. In the intact joint complex, the average dorsopalmar rotational displacement was approximately 9 degrees in each direction. Under the load limit, the dorsopalmar translational displacement averaged 0.9 mm and 0.5 mm respectively, proximal-distal translational displacement averaged 0.8 mm and 0.4 mm respectively, and distractional displacement averaged 0.3 mm. Based on the sequential sectioning it was found that the dorsal ligament provided 76% (SD 14) of the rotational resistance with palmar rotation of the capitate and 44% (SD 19) of translational constraint with palmar translation of the capitate. The deep ligament provided 51% (SD 15) of the rotational resistance with dorsal rotation of the capitate and 63% (SD 24) of translational resistance with dorsal translation of the capitate. With proximal-distal translation, the dorsal ligament was the most important constraint in each direction. In resisting distraction, each of the three ligaments was equally effective. Failure testing showed the deep ligament was strongest at 289 N, followed by the palmar at 171 N and the dorsal at 133 N.

Freeze-Dried Fascia Lata Allografts in the Reconstruction of Anterior Cruciate Ligament Defects

A study of 70 arthroscopic anterior cruciate ligament reconstructions with nonaugmented human freeze-dried fascia lata grafts is reported. The overall results are based on subjective, objective, and radiologic examinations as well as second-look arthroscopies at the one-year, four-year, and five-year follow-up evaluations. The average follow-up time was 4.5 years (range, two to seven years). Mention is made of pertinent points from patient histories, and an account is given of associated lesions that had been previously operated on or which were treated concomitantly. The subjective results show 82% excellent and good results, and the objective results show 95% excellent and good results. This difference may be explained by the subjective residual pain reported by every patient who suffered a work compensation injury; residual pain was not reported very often by those whose injuries were sports related. Forty-seven patients underwent second-look arthroscopies at one year, and seven underwent arthroscopy at four and five years after operation. These examinations provided very interesting clues as to the graft's future status. It was possible to identify zones of neovascularization, tissue invasion, and unraveling of the graft as well as to test for stability with a probe. Biopsies and histologic studies confirmed superficial and deep ligament revascularization as early as four months after operation. Results of arthroscopy at one year confirmed the results of physical examination and the prognosis for the graft.

Results of the surgical treatment of Morton's neuralgia in 58 operated intermetatarsal spaces followed over 6 (2-12) years.

In 45 patients (52 feet), 58 intermetatarsal spaces were operated on for Morton's neuralgia. The procedure included dorsal incision, division of the deep intermetatarsal ligament, and resection of the common digital nerve including the neuroma. The outcome of the operation was excellent in 13 clefts good in 20, fair in 14, and poor in 11 after a mean follow-up period of 6 years. Five clefts were reoperated, with improvement in four. The feet with Morton's neuralgia displayed a significantly higher rate of other foot pathologies than feet in a randomly selected control group. The results show the efficacy of the surgical treatment of Morton's neuralgia over a long follow-up period, with an improvement in 80% of cases.

The role of the posterolateral and cruciate ligaments in the stability of the human knee. A biomechanical study.

Injury to the posterolateral structures of the knee, including the popliteus tendon and arcuate complex, frequently results in poorly understood patterns of instability. To evaluate the static function of these tissues, we used a mechanical testing apparatus that allowed five degrees of freedom to test seventeen specimens from human cadavera at angles of flexion that ranged from zero to 90 degrees. Selective section of the lateral collateral ligament, popliteus-arcuate (deep) ligament complex, anterior cruciate ligament, and posterior cruciate ligament was performed. At all angles of flexion, the lateral collateral ligament and deep ligament complex functioned together as the principal structures preventing varus rotation and external rotation of the tibia, while the posterior cruciate ligament was the principal structure preventing posterior translation. However, at angles of flexion of 30 degrees or less, the amount of posterior translation after section of only the lateral collateral ligament and the deep structures was similar to that noted after isolated section of the posterior cruciate ligament. Isolated section of the posterior cruciate ligament did not affect varus or external rotation of the tibia at any position of flexion of the knee. When the posterior cruciate ligament was sectioned after the lateral collateral ligament and deep ligament complex had been cut, a large increase in posterior translation and varus rotation resulted at all angles of flexion. In addition, at angles of flexion of more than 30 degrees, external rotation of the tibia also increased. The application of internal tibial torque resulted in no increase in tibial rotation after isolated section of the anterior cruciate ligament or combined section of the lateral collateral ligament and deep ligament complex. However, combined section of all three structures increased internal rotation at 30 and 60 degrees of flexion. The increases in external rotation that were produced by section of the lateral collateral ligament and deep ligament complex were not changed by the addition of the section of the anterior cruciate ligament.

Irreducible Dislocation of the Metatarsophalangeal Joints of the Foot

An unusual dislocation of the metatarsophalangeal joints of the third, fourth, and fifth toes with fractures of the neck of the second metatarsal bone occurred in a 23-year-old man. Hyperextension of the metatarsophalangeal joints is the mechanism of injury and is substantiated by the anatomic investigation. The metatarsal head is trapped between the fibrocartilaginous plate on the plantar surface of the foot, the dorsal capsule and deep transverse metatarsal ligament on the dorsal surface, the flexor tendons on the lateral aspect and the lumbrical tendons on the medial aspect. Division of the fibrocartilaginous plate, the deep transverse ligament and the dorsal capsule facilitates reduction of dislocation.