Three-dimensional magnetic resonance imaging of the interosseous membrane of forearm: a new method using fuzzy reasoning

Biomechanical assessment of the central band of the interosseous membrane using shear wave elastography: reliability and reproducibility

The interosseous membrane of the forearm is an essential structure for the stability of the forearm skeleton, the most important part being the central band. The purpose of this study was to determine if shear wave elastography, a non-invasive ultrasound technique, can be used to measure shear wave speed in the central band and quantify stiffness. Fifteen healthy adult subjects were included (30 forearms). The participants forearms were positioned on an articulated plate, with their hand in neutral, pronated and then supinated positions of 30°, 60° and 90°. The shear wave speed was highest in 90° pronation (4.4 m/s (SD 0.3)) and 90° supination (4.4 m/s (SD 0.27)) indicating maximum stiffness in these positions. Its minimum value was in the neutral position, and either in 30° pronation or supination (3.5 m/s (SD 0.3)). Intra- and interobserver agreement was excellent, regardless of probe positioning or forearm mobilization. This study presents a reliable shear wave elastography measurement protocol to describe the physiological function of the central band of the interosseous membrane in healthy adults.Level of evidence: IV.

Isolated Proximal Radioulnar Joint Instability: Anatomy, Clinical Presentation, and Current Treatment Options

Isolated proximal radioulnar joint instability is an uncommon and often challenging problem that may manifest as recurrent instability of the proximal aspect of the radius, usually during forearm pronation and supination. Instability is due to deficiency of the stabilizing structures around the proximal aspect of the radius, and biomechanical studies have highlighted the importance of the annular ligament and the interosseous membrane in both transverse and longitudinal plane stability. Reconstruction of the stabilizing structures around the radial head often is indicated in cases of recurrent instability and includes joint-preserving procedures such as annular ligament reconstruction, proximal ulnar osteotomy, and interosseous membrane reconstruction. Rarely, salvage procedures such as interpositional arthroplasty or 1-bone forearm reconstruction are necessary. A thorough understanding of the anatomic structures that stabilize the proximal aspect of the radius and the complexities of forearm biomechanics is required in order to successfully diagnose and manage this condition.

Digitalization of the IOM: A comprehensive cadaveric study for obtaining three-dimensional models and morphological properties of the forearm's interosseous membrane

State-of-the-art of preoperative planning for forearm orthopaedic surgeries is currently limited to simple bone procedures. The increasing interest of clinicians for more comprehensive analysis of complex pathologies often requires dynamic models, able to include the soft tissue influence into the preoperative process. Previous studies have shown that the interosseous membrane (IOM) influences forearm motion and stability, but due to the lack of morphological and biomechanical data, existing simulation models of the IOM are either too simple or clinically unreliable. This work aims to address this problematic by generating 3D morphological and tensile properties of the individual IOM structures. First, micro- and standard-CT acquisitions were performed on five fresh-frozen annotated cadaveric forearms for the generation of 3D models of the radius, ulna and each of the individual ligaments of the IOM. Afterwards, novel 3D methods were developed for the measurement of common morphological features, which were validated against established optical ex-vivo measurements. Finally, we investigated the individual tensile properties of each IOM ligament. The generated 3D morphological features can provide the basis for the future development of functional planning simulation of the forearm.

Procedure Oriented Torsional Anatomy of the Forearm for Spasticity Injection

: This is the second in a series of articles related to the concept of "torsional" anatomy. The objective of this article is to provide musculoskeletal ultrasound (MSKUS) anatomy of the forearm in the position of hemispastic flexion as a reference relevant to needle procedures.

METHODS

The MSKUS images were obtained in a healthy human subject. Marker dots were placed over common injection sites in the forearm for spasticity. The MSKUS probe was centered over each dot to obtain a cross-sectional view. A pair of MSKUS images was recorded for each site: the first in anatomic neutral and second in hemiparetic spastic position. The images were compared side to side. In addition, a video recording was made at each site to track the movement of the muscles and nerves during internal rotation.

RESULTS

The pronator teres (PT) rotated medially and the brachialis and biceps tendon rotated in view. In addition, the median nerve became more superficial. The flexor carpi radialis rotated medially and was replaced by PT and the median nerve. The flexor carpi ulnaris and flexor digitorum profundus rotated medially and were replaced by the flexor carpi radialis, PT and median nerve. The flexor digitorum superficialis was replaced by the brachioradialis, extensor carpi radialis brevis, and radial nerve. The brachioradialis was replaced by the extensor carpi radialis brevis and extensor digitorum communis.

DISCUSSION

Intended muscle targets rotate out of view and injection range. These are replaced by other muscles and nerves that could inadvertently be injected. This potentially could result in both increased complications and decreased efficacy of the procedure.

CONCLUSIONS

It is hoped that this series of images will increase the accuracy and safety of needle placement for spasticity injections in the forearm.

The role of ultrasound and magnetic resonance imaging in the evaluation of the forearm interosseous membrane. A review

The interosseous membrane of the forearm is an important structure to consider in cases of elbow and forearm trauma; it can be injured after elbow or forearm fractures, leading to longitudinal forearm instability. Diagnosis of interosseous membrane injuries is challenging, and failure in diagnosis may result in poor clinical outcomes and complications. Magnetic resonance imaging and ultrasound have shown to be valuable methods for the evaluation of this important structure. Both techniques have advantages and limitations, and its use should be adapted to each specific clinical scenario. This article presents an up-to-date literature review regarding the use of ultrasound and magnetic resonance imaging in the forearm interosseous membrane evaluation.

The middle radioulnar joint and triarticular forearm complex

The forearm is composed of the radial and ulnar shafts, which are linked by the interosseous membrane and intercalated between the elbow and wrist. The radius and ulna are connected by three joints, the proximal, middle, and distal radioulnar joints. The forearm ensures pronation/supination and longitudinal load transfer. The biomechanical and clinical relevance of the proximal and distal radioulnar joints is well established. In contrast, the middle radioulnar joint was considered relatively unimportant until studies published in the last decade showed that it fulfils crucial biomechanical functions and is of considerable clinical significance. We believe the conventional concept in which the forearm is viewed as part of either the elbow or the wrist is outdated and that a more relevant concept describes the forearm as a triarticular complex that functions as a full-fledged entity. In this concept, the three forearm radioulnar joints (proximal, middle, distal) work together to provide stability, mobility and load transfer. Here, we will argue for the relevance of the triarticular complex concept based on published data about forearm biomechanics and pathological conditions.

Interosseous membrane of the forearm: length change of ligaments during forearm rotation

PURPOSE

An earlier anatomic study described five ligamentous components in the interosseous membrane of the forearm (central band, accessory band, distal oblique bundle, proximal oblique cord, and dorsal oblique accessory cord) and provided their precise location of attachment. In the present study, we investigated in vivo length changes of these five ligaments during forearm rotation to understand the function of each ligament.

METHODS

We acquired computed tomographies of nine forearms from seven healthy volunteers for 3 rotation positions: maximum pronation, neutral position, and maximum supination. We created 3-dimensional models of the radius, ulna, and the 5 ligaments by combining osseous images and anatomic data of ligament attachment. We calculated 3-dimensional ligament lengths between attachments during forearm rotation using a markerless bone registration technique. We also examined relationships between the axis of forearm rotation and each ligament.

RESULTS

The distal 3 ligaments (central band, accessory band, and distal oblique bundle) had little change in length during forearm rotation, with their ulnar attachments located almost on the axis of forearm rotation. The 2 proximal ligaments (proximal oblique cord and dorsal oblique accessory cord) changed substantially in length, with their attachments out of the course of the axis.

CONCLUSIONS

The distal 3 ligaments of the interosseous membrane are essentially isometric stabilizers of the forearm. The distal oblique bundle in the distal membranous portion may stabilize the distal radioulnar joint in 40% of human subjects who have this ligament.

Interosseous membrane of the forearm: an anatomical study of ligament attachment locations

PURPOSE

The interosseous membrane (IOM) of the forearm is a stout ligamentous complex that reportedly comprises several ligamentous components. The purpose of this cadaveric study was to define all IOM ligaments and to clarify the precise attachment locations.

METHODS

Thirty forearms from 15 embalmed cadavers were used. After dissection, all IOM ligaments were identified, and attachments were measured from the tip of the radial styloid or the ulnar head. Attachment locations were represented as a percentage of total bone length from the distal end of the radius or ulna.

RESULTS

The IOM included 5 kinds of ligaments: central band, accessory band, distal oblique bundle, proximal oblique cord, and dorsal oblique accessory cord. The most distal and proximal ends of the radial origin of the central band were 53% and 64% of total radial length from the tip of the radial styloid, whereas those of the ulnar insertion were 29% and 44% of total ulnar length from the ulnar head. The center point of the radial origin and ulnar insertion of the accessory band were 37% and 23%, respectively. The center points of the ulnar origins and radial insertions were 15% and 10% for the distal oblique bundle; 80% and 79% for the proximal oblique cord; and 64% and 62% for the dorsal oblique accessory cord, respectively.

CONCLUSIONS

The present study clarified precise attachment locations of all representative IOM ligaments. This information will be useful in planning proper graft placement in ligament reconstruction surgery and for future biomechanics research into the function of the IOM ligaments.

[Traumatic pathology of antibrachial interosseous membrane of forearm]

The antibrachial interosseous membrane (IOM) is taught over an average length of 10.6cm between the diaphyses of the radius and ulna bone. It looks like a stitch with fibers running from the ulna to the radius and from proximal to distal and fibers running from distal to proximal. The central band, which is the middle part of the fibers directed from distal to proximal has mechanical properties similar to those of a ligament and act as a ligamentous structure embedded in the larger membranous complex of the IOM. The interosseous membrane has a double function: it stabilizes transversally the forearm's two bones and stabilizes longitudinally the two bones by transferring loads from the radius to the ulna. Load transmission varies according to the prono-supination position, the varus-valgus constraints on the elbow and the inclination of the wrist, making interpretation of the experimental data difficult. One should consider the forearm as a whole and the interosseous membrane with the two diaphyses should be regarded as a middle radio-ulnar joint, intercalated between the proximal and distal radio-ulnar joint. Those three articulations or links between radius and ulna act synergistically to stabilize and optimize repartition of loads. Functional loss of one of these links, and of course of more than one, will severely modify the forearm function. Essex-Lopresti lesion, which represents the functional loss of all three links, is the most destabilizing forearm lesion. Imaging of the interosseous membrane is difficult. MRI allows for static imaging of the interosseous membrane but there are often artifacts due to previous trauma or surgical procedures. Dynamic sonography helps to visualize all the lesions and will probably be part of the evaluation of every severe forearm injury. Surgical treatment depends on the gravity of the lesions of the different links. Interosseous membrane reconstruction is still the most difficult technique and most of the previously reported ligamentoplasties cannot answer all the biomechanical constraints. We describe a ligamentoplasty based on the biomechanics whose technique has been validated by cadaveric experiments. First surgical cases are promising.

Pronation contracture of the forearm due to iatrogenic scar formation of the distal membranous part of the forearm interosseous membrane

A case of successful treatment of pronation contracture of the forearm due to iatrogenic scar formation in the distal membranous part of the interosseous membrane of the forearm is presented and the management of this problem is discussed.

The “muscular hernia sign”: an original ultrasonographic sign to detect lesions of the forearm’s interosseous membrane

The total disruption of the forearm's interosseous membrane can lead to an Essex-Lopresti syndrome. The diagnosis must be done early for a better prognostic. Incomplete lesions can aggravate and an early diagnosis of incomplete lesions is a challenging problem. Magnetic resonance imaging is the gold standard but remains expensive, and is hard to obtain in an emergency. On the contrary, ultrasonography is cheap, accessible in an emergency, and dynamical tests can be performed easily. Twelve fresh frozen forearms were randomized in four groups. The membrane was divided into three parts (proximal, middle, and distal thirds). Each group was prepared with variable patterns of lesions. Two radiologists performed an ultrasonographic (US) examination of these forearms. They were blinded with respect to the lesional status of the forearms. Each examination consisted of two stages: static and dynamic. During the dynamic examination, the radiologist looked for the "muscular hernia sign". The results of their examinations were compared with the real lesional status. The static examination was very efficient in the proximal and middle parts of the membrane, and less reliable in the distal third. With the dynamical examination, no mistake occurred at the proximal and middle parts of the forearm, and there was only one at the distal part. The US examination of the interosseous membrane is very efficient to detect incomplete lesions, mostly, if dynamical tests are performed looking for a "muscular hernia sign".

Forearm interosseous membrane trauma: MRI diagnostic criteria and injury patterns

OBJECTIVE

Define criteria for interosseous membrane (IOM) injury diagnosis using MRI, and characterize patterns of IOM disruption following forearm trauma. Our hypothesis is that most IOM injuries occur along the ulnar insertion, and MRI should be obtained following forearm trauma to assess IOM competency.

DESIGN

Sixteen cadaver forearms were subjected to longitudinal impact trauma. Prior to and following injury, MR images were examined by a board-certified musculoskeletal radiologist using pre-defined criteria for determining IOM integrity. Each specimen was dissected and the viability/pattern of injury examined. The MRI and dissection results were compared using a double-blinded methodology.

RESULTS

Eight of the 16 specimens demonstrated IOM trauma. Seven specimens demonstrated complete IOM disruption from the ulnar insertion, and one revealed a mid-substance tear with intact origin and insertion. The dorsal oblique bundle was disrupted in four specimens. MRI analysis identified IOM injury in seven of the eight forearms. The injury location was correctly identified in six specimens when compared to dissection observations. MRI determination of IOM injury demonstrated a positive predictive value of 100%, a negative predictive value of 89%, a sensitivity of 87.5% and a specificity of 100%.

CONCLUSION

Our findings demonstrate the accuracy of MRI in identifying IOM disruption, and its ability to localize specific injuries in a clinically relevant model of forearm trauma. The injury patterns demonstrated most lesions occurred along the IOM's ulnar insertion, and in half of the injured specimens there was concomitant dorsal oblique bundle disruption.

Contribution of the interosseous membrane to distal radioulnar joint constraint

PURPOSE

Although forearm injuries are accompanied frequently by rupture to the interosseous membrane (IOM) diagnosis of the extent of IOM injury is difficult. In this study we evaluated distal radioulnar joint (DRUJ) laxity caused by both partial and complete IOM disruption and compared these quantitative measurements with the common clinical manual evaluation of DRUJ laxity and dislocatability.

METHODS

Human cadaveric forearms (n = 8) were used in this study. Skin, muscles, and tendons were removed. The specimens were mounted on an experimental apparatus that allowed the radius to move freely about the fixed ulna. Tests were performed in neutral rotation, 60 degrees pronation, and 60 degrees supination. Under various conditions of IOM sectioning testing was performed by volary and dorsally translating the radius relative to the ulna in the coronal plane of the radius. Testing was performed both qualitatively as would be performed in the clinic and quantitatively with an instrumented probe.

RESULTS

Our results show that dorsal dislocation of the radius relative to the ulna strongly suggests distal IOM rupture. Disengagement of the radius from the DRUJ indicated injury to the distal and middle IOM. The distal IOM constrained volar and dorsal laxity of the radius at the DRUJ in all forearm rotation positions. The midportion of the IOM constrained laxity except in the volar direction of the pronated forearm. The proximal IOM did not constrain the proximal radius except dorsally for the pronated forearm position.

CONCLUSIONS

The IOM, in particular the distal IOM, plays an important role in constraining dorsal dislocation of the radius at the DRUJ.

Forearm interosseous membrane imaging and anatomy

OBJECTIVE

To determine the regional thickness variation of the interosseous membrane (IOM) along the forearm and validate magnetic resonance imaging of the IOM with laser micrometry.

DESIGN AND PATIENTS

Axial thickness measurements of 12 cadaver forearms were obtained using magnetic resonance imaging (MRI) at radial, central, and ulnar locations. The specimens were dissected, and IOM thickness measured using a laser micrometer. MRI and laser measurements of the main and oblique IOM bundles were compared. An axial thickness profile was plotted versus forearm length, and radial, central, and ulnar positions were compared.

RESULTS

The main bundle thickness was 2.18+/-0.20 mm using laser micrometry, which was not significantly different from MRI measurements (1.86+/-0.25 mm, p=0.11, power = 0.84). The dorsal oblique bundle thickness was not significantly different between measurement methods (2.93+/-0.77 mm and 3.30+/-1.64 mm using laser micrometry and MRI respectively, p=0.75, power = 0.04). Both methods demonstrated a progressive increase in thickness proximally within the forearm. MRI measurements demonstrated a significantly greater thickness increase in the radial location compared to the central location (slope = 2.26 and 1.05, r(2)=0.31 and 0.12 respectively, p<0.05). The ulnar slope was not significantly different from zero ( r(2)=0.02, p>0.05).

CONCLUSION

Our findings describe the varying IOM anatomy using MRI, and determined the location of the clinically important IOM fiber bundles. This study confirms the accuracy of MR imaging of the IOM by comparison with a laser micrometer, and demonstrates the thickness variation along the forearm. This information may be used to identify changes in IOM anatomy with both acute IOM injury and chronic fiber attenuation.

Passive strain distribution in the interosseous ligament of the forearm: implications for injury reconstruction

PURPOSE

For severe forearm injuries such as an Essex-Lopresti fracture-dislocation, functional reconstruction necessitates repair of the interosseous ligament (IOL) to restore normal load sharing between the radius and ulna. Locating or tensioning such a reconstruction improperly can lead to abnormal load sharing and/or restriction of forearm rotation. The normal IOL strains should indicate the proper location of reconstruction grafts and the proper forearm rotation for tensioning the grafts. The objective of this study was to quantify the passive strain distribution of the IOL of the forearm with passive rotation of the forearm throughout the range of motion.

METHODS

The 3-dimensional motions of the radius with respect to the ulna were measured throughout forearm rotation in 10 cadaveric forearms by using an instrumented spatial linkage. From the bone motions and ligament insertion site geometry from dissection and computed tomographic scanning, insertion site motions were determined and used to calculate changes in ligament fiber lengths.

RESULTS

The measured strain distribution in the IOL was nonuniform and varied with forearm rotation. The overall magnitude of IOL strain was found to be greatest in supination and smallest in pronation. In supination the strains varied across fibers with strains being greatest in the distal fibers and lowest in the proximal fibers. Strains in neutral rotation were uniform across fibers. Although fibers were generally slack in pronation proximal fibers were less slack than distal fibers.

CONCLUSIONS

The results of this study indicate that fiber strains in the IOL vary from proximal to distal and depend on forearm rotation. Our data suggest that to prevent restriction of forearm rotation all grafts should be tensioned in supination, where measured strains were generally highest. Our data also suggest that a 2-bundle IOL reconstruction may be necessary for proper load transfer between the radius and ulna in both supination and pronation.

The role of surgery and resection margins in the treatment of Ewing's sarcoma

Because of the enormous progress in surgery in the treatment of patients with tumors, the current study analyzed the influence of wide surgical resection margins on the outcome of patients with Ewing's sarcoma. Between 1980 and 1994, 86 patients were treated with systemic therapy and surgery (biopsy in six patients, tumor resection in 80 patients). Forty-four patients also had radiation therapy. The 5-year overall survival was 56.8% (5-year disease-free survival, 59.4%). The 5-year overall survival after radical or wide resection was 60.2% (5-year disease-free survival, 58.2%), in comparison with 40.1% (46.7%) after marginal or intralesional resection. Two patients with inadequate resection margins had local recurrences. In addition to the influence of neoadjuvant chemotherapy for higher survival rates (5-year overall survival with a good response was 80.2% versus 41.7% with a poor response), adequate surgical margins significantly affect the outcome for patients with Ewing's sarcoma.

Magnetic resonance imaging of the interosseous membrane of the forearm

BACKGROUND

Diagnosis of damage to the interosseous membrane of the forearm after trauma is difficult. Patients with a proximal radial fracture and associated damage to the interosseous membrane may have wrist pain in association with subluxation or dislocation of the distal radioulnar joint. Accurate identification of injury to the interosseous membrane may allow better planning of surgical treatment.

METHODS

T1 and T2-weighted magnetic resonance images that were made in the axial, sagittal, and coronal planes were used to evaluate the interosseous membrane in the forearms of cadavera, volunteers, and patients. The images were evaluated subjectively by two orthopaedic surgeons and a musculoskeletal radiologist.

RESULTS

The interosseous membrane was most consistently visualized on the axial images. Axial T2-weighted images showed the interosseous membrane clearly. The addition of fat-suppression techniques allowed abnormalities to be identified more accurately. Fast-spin-echo techniques were used to obtain data quickly and accurately.

CONCLUSIONS

The intact and disrupted interosseous membrane can be evaluated with use of magnetic resonance imaging. Axial T2-weighted fast-spin-echo images with fat suppression in the middle one-third of the forearm provide the most accurate information.

Normal kinematics of the interosseous membrane during forearm pronation-supination--a three-dimensional MRI study

We studied in vivo dynamic shape changes of the interosseous membrane (IOM) during forearm rotation using three-dimensional magnetic resonance imaging (3D-MRI), and simultaneously analysed 3D-motion of the forearm rotation. Wavy deformities were seen in the IOM in the pronated position, and similar small changes were also seen at maximum supination (average 82 degrees ) and in the neutral position. These dynamic changes mainly occurred in the membranous part of the IOM, whereas the tendinous part demonstrated minimal dynamic changes during rotation in all subjects. On the dorsal aspect, deformity around the dorsal oblique cord was seen at maximum pronation. From this 3D-MRI observation, the tendinous part is considered to be taut during rotation to provide stability between the radius and ulna, because of its straightness and less dynamic changes. The more deformable membranous part is important to allow for smooth rotation, since it lies at a distance from the rotation axis. Inelasticity developing in the membranous part from trauma may pre-dispose to pronation-supination contracture. The radius rotated around the ulna from maximum supination to 45 degrees pronation. At maximum pronation (average 75 degrees ), the radius translated average 1.8 mm palmarly and rotated average 4.0 degrees ulnarward on the ulna. Incongruity of the distal radioulnar joint, contraction of the pronator quadratus and torsion between the radius and ulna at maximum pronation may produce this irregular motion of the radius and cause the dynamic changes of the IOM.