Forearm interosseous membrane trauma: MRI diagnostic criteria and injury patterns

Radiographic Comparison of Forearm Symmetry in Healthy Individuals and its Importance in the Diagnosis of Longitudinal Radioulnar Dissociation

PURPOSE

Longitudinal radioulnar dissociation (LRD) is an injury often missed upon initial presentation. A recent study examined a radiographic screening test in cadavers that showed increased interosseous distance when the interosseous ligament (IOL) was divided. For this test to be clinically useful, it is necessary for uninjured forearms to have similar interosseous spaces. The purpose of this study was to determine the typical differences between right and left interosseous spaces of healthy individuals.

METHODS

Anterior-posterior x-rays of bilateral forearms in maximum supination of 28 surgical residents with no history of injury were obtained. These images were uploaded into a picture archiving and communication system and then digitized. The length of the radius was measured (Xr). The maximum interosseous distance (Dmax) between the radius and ulna as well as the interosseous distance at a location 0.3 Xr from the distal radioulnar joint was measured. The right and left arm distances were compared. Also, an outlier analysis was used to evaluate forearm rotational asymmetry between right and left arms.

RESULTS

The outlier analysis revealed two sets of forearm x-rays were rotationally different compared to the rest of the group due to asymmetric arm positioning; these data were excluded from the analysis. The average difference in Dmax was 1.7 mm (standard deviation [SD] 1.5) between right and left arms, and this was found at a position of 0.28 Xr on average. The difference in interosseous distance measured at a fixed location 0.3 Xr was 1.6 mm (SD 1.5). No significant difference was found between the paired right and left arms for Dmax or at 0.3 Xr.

CONCLUSIONS

There does not appear to be any significant difference between the maximum interosseous distance of right and left arms in healthy individuals. Therefore, analyzing bilateral forearm x-rays may be a simple LRD screening test.

CLINICAL RELEVANCE

Understanding the degree of normal variation in the forearm bone spacing might inform evaluation of abnormal forearm bone alignment resulting from LRD.

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.

Ultrasound-guided transection of the interosseous membrane of the forearm

We sought to evaluate the feasibility of ultrasound-guided transection of the interosseous membrane of the forearm. The study involved ten forearms from five fresh cadavers. An ultrasound scanner (Toshiba™ Aplio V®, Toshigi, Japan) with a linear probe (Toshiba™ PLT-805AT 8Mhz) and a 25-cm long Kemis® knife (NewClip Technics™, Cholet, France), which was specially created for this study, were used. An approach to the distal and proximal radioulnar joint was made before the transection. The induced muscle hernia sign and the radius joystick test were performed to confirm the effectiveness of the ultrasound-guided transection. Complete dissection of the posterior surface of the forearm was done to check for complications and evaluate the quality of the transection. We registered nine complete transections of the interosseous membrane. The muscular hernia sign was present in all the cases performed. The joystick test was positive in eight cases. One forearm had a vascular complication. This ultrasound-guided interosseous membrane transection technique is feasible and effective with limited vascular and nerve risks. A prospective clinical study is required to validate this anatomical work.

Evolution of the Ring Concept for the Forearm and Its Implication on Treatment: From Galeazzi, Monteggia, Essex-Lopresti, and Darrach to the Current Era

Geometrically, rings distribute their stress along their arc instead of concentrating at any one point. The forearm ring is composed of the radius, ulna, proximal radioulnar joint, and distal radioulnar joint. The annular ligament, interosseous membrane, and triangular fibrocartilage complex link and stabilize the ring. Injuries to the forearm occur along a continuum with recognized patterns of ring disruption, including Galeazzi, Monteggia, and Essex-Lopresti injuries. The Darrach procedure causes a disruption to the forearm ring and can lead to painful convergence between the radius and distal ulnar stump. Injuries to the forearm ring are unstable. Management of forearm injuries is centered on the restoration of the anatomy and stability of the forearm ring. Forearm ring injuries and their treatment are discussed in this article.

Magnetic resonance imaging evaluation of the distal oblique bundle in the distal interosseous membrane of the forearm

Background

Some cadaveric studies have reported the role of the distal oblique bundle (DOB) in the distal radioulnar joint stability. We aimed to determine whether the presence of the DOB can be identified and its thickness can be measured in magnetic resonance imaging (MRI) examinations.

Methods

We retrospectively reviewed 468 wrist and forearm MRIs. Inclusion criteria were wrist or forearm MRIs taken in patients older than 18 years of age, and exclusion criteria were patients with acute wrist or forearm fractures, infections, or malignant tumors. We selected 80 MRIs that provided adequate coverage of the distal interosseous membrane (DIOM). The thickness of the DIOM in the T2-weighted transverse plane was measured on the picture archiving and communicating system. We used a model-based clustering method to determine whether some individuals have thicker DIOMs that can be considered as the DOB.

Results

The thickness of the DIOM demonstrated a bimodal distribution, indicating the presence of patients with a thick DIOM (DOB). The model-based clustering method indicated that the optimal cutoff point was 1.0 mm. Twenty-six individuals (32.5%) had thick DIOMs with a mean thickness of 1.4 mm (standard deviation, 0.2 mm), while 54 individuals (67.5%) had thin DIOMs with a mean thickness of 0.6 mm (standard deviation, 0.2 mm).

Conclusion

Our study demonstrates that it is possible to identify the DOB and measure its thickness using MRI. Future in-vivo studies of the DOB using MRI in patients with distal radioulnar joint pathologies may reveal its role in the distal radioulnar joint stability.

Longitudinal instability of the forearm

The Essex Lopresti lesion is a rare triad of injury to the radial head, interosseous membrane of the forearm and distal radio-ulnar joint, which results in longitudinal instability of the radius. If unrecognized this leads to chronic pain and disability which is difficult to salvage. Early recognition and appropriate treatment is therefore desirable to prevent long-term problems. The aim of this article is to review the pathoanatomy of longitudinal radius instability and use the existing literature and authors' experience to provide recommendations for recognition and treatment of acute and chronic forearm instability, including description of the author's technique for interosseous membrane reconstruction.

The treatment of the acute Essex-Lopresti injury

The Essex-Lopresti injury (ELI) of the forearm is a rare and serious condition which is often overlooked, leading to a poor outcome. The purpose of this retrospective case study was to establish whether early surgery can give good medium-term results. From a group of 295 patients with a fracture of the radial head, 12 patients were diagnosed with ELI on MRI which confirmed injury to the interosseous membrane (IOM) and ligament (IOL). They were treated by reduction and temporary Kirschner (K)-wire stabilisation of the distal radioulnar joint (DRUJ). In addition, eight patients had a radial head replacement, and two a radial head reconstruction. All patients were examined clinically and radiologically 59 months (25 to 90) after surgery when the mean Mayo Modified Wrist Score (MMWS) was 88.4 (78 to 94), the mean Mayo Elbow Performance Scores (MEPS) 86.7 (77 to 95) and the mean disabilities of arm, shoulder and hand (DASH) score 20.5 (16 to 31): all of these indicate a good outcome. In case of a high index of suspicion for ELI in patients with a radial head fracture, we recommend the following: confirmation of IOM and IOL injury with an early MRI scan; early surgery with reduction and temporary K-wire stabilisation of the DRUJ; preservation of the radial head if at all possible or replacement if not, and functional bracing in supination. This will increase the prospect of a good result, and avoid the complications of a missed diagnosis and the difficulties of late treatment.

MRI detection of forearm soft tissue injuries with radial head fractures

BACKGROUND

This study aims to evaluate the incidence of forearm soft tissue abnormalities associated with radial head fracture severity based on the Mason classification system.

METHODS

Eighteen patients (age 18-45 years) were prospectively evaluated with elbow radiographs and magnetic resonance imaging (MRI) following longitudinal forearm trauma. MRI was performed within 10 days of the initial injury. Radiographs and MR images were evaluated in a blinded fashion by two musculoskeletal radiologists.

RESULTS

Thirteen of 18 patients presented with Mason type I radial head fractures. In all patients with Mason type I fractures, the interosseous membrane (IOM) was intact. Two patients had Mason type II fractures with associated partial and compete tearing of the IOM and three patients had Mason type III fractures with complete tearing of the IOM. Edema was noted in the pronator quadratus in six of 13 type I injuries and seen in all type II and III injuries. No structural forearm soft tissue abnormalities were present in patients with Mason type I injuries. The presence of edema within the pronator quadratus correlated with distal forearm pain.

CONCLUSIONS

The severity of radial head fracture correlates with longitudinal forearm injury evidenced by the presence of IOM tearing. The findings suggest patients with Mason type II or III fractures of the radial head should undergo further evaluation of the forearm for associated soft tissue injuries. Edema within the pronator quadratus was present following forearm trauma regardless of the severity of fracture and was related to symptomatic forearm pain.

Forearm instability

Forearm instability results from trauma, which disrupts the radial head, the interosseous membrane, and the triangular fibrocartilage complex. Inadequate treatment of injuries to these forearm stabilizers may result in the complex problem of chronic longitudinal forearm instability. Delayed recognition and/or treatment of injuries producing forearm dissociation has led to poor patient outcomes, which makes timely recognition of the injury pattern imperative. This article discusses relevant aspects of forearm anatomy and current concepts in the diagnosis and treatment options for this complex injury pattern.

Fractures of the radial head

Most fractures of the radial head are stable undisplaced or minimally displaced partial fractures without an associated fracture of the elbow or forearm or ligament injury, where stiffness following non-operative management is the primary concern. Displaced unstable fractures of the radial head are usually associated with other fractures or ligament injuries, and restoration of radiocapitellar contact by reconstruction or prosthetic replacement of the fractured head is necessary to prevent subluxation or dislocation of the elbow and forearm. In fractures with three or fewer fragments (two articular fragments and the neck) and little or no metaphyseal comminution, open reduction and internal fixation may give good results. However, fragmented unstable fractures of the radial head are prone to early failure of fixation and nonunion when fixed. Excision of the radial head is associated with good long-term results, but in patients with instability of the elbow or forearm, prosthetic replacement is preferred. This review considers the characteristics of stable and unstable fractures of the radial head, as well as discussing the debatable aspects of management, in light of the current best evidence.

The Essex-Lopresti lesion

The Essex-Lopresti lesion represents a severe injury of the forearm unit. In the 1940s, it’s pathology and consequences have already been mentioned by several authors. Over the course of time, the pathophysiology of the lesion was displayed in more detail. Therefore, an intensive analysis of the involved anatomic structures was done. The interosseous membrane was shown to play a major role in stabilising the forearm unit, in the situation of a fractured radial head, which is the primary stabiliser of the longitudinal forearm stability. Moreover, biomechanical analyses showed a relevant attribution of the distal radio-ulnar joint to the forearm stability. If, in the case of a full-blown Essex-Lopresti lesion, the radial head, the interosseous membrane and the distal radio-ulnar joint are injured, proximalisation of the radius will take place and will come along with secondary symptoms at the elbow joint and the wrist. According to actual studies, the lesion seems to occur more often than realised up to now. Thus, to avoid missing the complex injury, subtle clinical diagnosis combined with adequate imaging has to be undertaken. If the lesion is confirmed, several operative treatment options are available, yet not proofed to be sufficient.

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 intra-operative radius joystick test to diagnose complete disruption of the interosseous membrane

Disruption of the interosseous membrane is easily missed in patients with Essex-Lopresti syndrome. None of the imaging techniques available for diagnosing disruption of the interosseous membrane are completely dependable. We undertook an investigation to identify whether a simple intra-operative test could be used to diagnose disruption of the interosseous membrane during surgery for fracture of the radial head and to see if the test was reproducible. We studied 20 cadaveric forearms after excision of the radial head, ten with and ten without disruption of the interosseous membrane. On each forearm, we performed the radius joystick test: moderate lateral traction was applied to the radial neck with the forearm in maximal pronation, to look for lateral displacement of the proximal radius indicating that the interosseous membrane had been disrupted. Each of six surgeons (three junior and three senior) performed the test on two consecutive days. Intra-observer agreement was 77% (95% confidence interval (CI) 67 to 85) and interobserver agreement was 97% (95% CI 92 to 100). Sensitivity was 100% (95% CI 97 to 100), specificity 88% (95% CI 81 to 93), positive predictive value 90% (95% CI 83 to 94), and negative predictive value 100%). This cadaveric study suggests that the radius joystick test may be useful for detecting disruption of the interosseous membrane in patients undergoing open surgery for fracture of the radial head and is reproducible. A confirmatory study in vivo is now required.

UNUSUAL PATTERN OF ESSEX-LOPRESTI INJURY WITH NEGATIVE PLAIN RADIOGRAPHS OF THE WRIST: A CASE REPORT AND LITERATURE REVIEW

The Essex-Lopresti injury consists of a fracture of the radial head, rupture of the interosseous membrane and disruption of the distal radioulnar joint. The greatest challenge with this injury pattern is the diagnosis, because it is frequently missed and the attention usually focused on the elbow joint. In this paper we report an unusual pattern of Essex-Lopresti injury with a radial neck fracture, a tear of the interosseous membrane and a disruption of the distal radioulnar joint in which initial wrist radiographs did not show significative abnormalities. Open reduction and internal fixation for the radial head fracture was performed. Forearm rotation was locked with two Kirschner wires from ulna to radius to allow interosseous membrane to heal.

This case is even more difficult to diagnose than classic Essex-Lopresti pattern because of the absence of radius shortening, due to this specific radius fracture pattern, and also the absence of distal radioulnar joint dislocation. When treating a radial head fracture but also a radial neck fracture, interosseous membrane injury should be suspected to avoid misleading in diagnosis.

Galeazzi fracture

Galeazzi fracture is a fracture of the radial diaphysis with disruption at the distal radioulnar joint (DRUJ). Typically, the mechanism of injury is forceful axial loading and torsion of the forearm. Diagnosis is established on radiographic evaluation. Underdiagnosis is common because disruption of the ligamentous restraints of the DRUJ may be overlooked. Nonsurgical management with anatomic reduction and immobilization in a long-arm cast has been successful in children. In adults, nonsurgical treatment typically fails because of deforming forces acting on the distal radius and DRUJ. Open reduction and internal fixation is the preferred surgical option. Anatomic reduction and rigid fixation should be followed by intraoperative assessment of the DRUJ. Further intraoperative interventions are based on the reducibility and postreduction stability of the DRUJ. Misdiagnosis or inadequate management of Galeazzi fracture may result in disabling complications, such as DRUJ instability, malunion, limited forearm range of motion, chronic wrist pain, and osteoarthritis.

Forearm instability

Forearm instability is a complex problem resulting from traumatic disruption of the forearm stabilizers: the radial head, the interosseous membrane, and the triangular fibrocartilage complex. Dissociation of the forearm unit is often underrecognized and therefore inadequately treated, leading to poor patient outcomes. The goals of this article are to impart an understanding of the forearm anatomy and the current concepts in the diagnosis and treatment options for this complicated problem.

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.

Radial head fractures--an update

Radial head fractures are the most common fractures occurring around the elbow. Although radial head fractures can occur in isolation, associated fractures and ligament injuries are common. Assembling the clinical presentation, physical examination, and imaging into an effective treatment plan can be challenging. The characteristics of the radial head fracture influence the technique used to optimize the outcome. Fragment number, displacement, impaction, and bone quality are considered when deciding between early motion, fragment excision, and radial head excision, repair, or replacement. Isolated, minimally displaced fractures without evidence of mechanical block can be treated nonsurgically with early active range of motion (ROM). Partial, displaced radial head fractures without evidence of mechanical block can be treated either nonsurgically or with open reduction internal fixation (ORIF), as current evidence does not prove superiority of either strategy. For displaced fractures with greater than 3 fragments, radial head replacement is recommended. Radial head arthroplasty may be preferred over tenuous fracture fixation in the setting of associated ligament injuries when maintenance of joint stability could be compromised by ineffective fracture fixation.

Essex-lopresti injuries

The Essex-Lopresti injury results from a high energy trauma to the upper extremity causing significant instability to the forearm joint. The radial head is fractured, the interosseous membrane is torn, and the distal radioulnar joint is disrupted. Frequently, the greatest challenge with this specific injury pattern is the diagnosis, because it is often missed in the emergency room. Once the diagnosis has been established, surgical treatment focuses on the elbow (radial head fracture) and the wrist (distal radioulnar joint disruption) to restore forearm length and stability. Chronic or untreated Essex-Lopresti lesions continue to challenge treating physicians and often require salvage or reconstructive procedures to minimize pain and return function.

[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.

Longitudinal radioulnar dissociation: identification and treatment of acute and chronic injuries

In this article we describe the fundamental concepts that were established by Essex-Lopresti over 50 years ago and explore the current concepts in anatomy, biomechanics, diagnosis, and treatment for longitudinal radioulnar dissociation. Moreover, we present encouraging results for treating chronic injuries to the IOM achieved by bone-ligament-bone (BLB) reconstruction using a patellar tendon graft, giving hope for this seemingly unforgiving injury. A treatment algorithm is also provided to aid in the management of acute and chronic longitudinal radioulnar dissociation.