Interosseous membrane reconstruction for forearm longitudinal instability

Forearm longitudinal instability results from an axial load to the forearm with fracture or dislocation of the radial head and disruption of the interosseous membrane and that of the distal radioulnar joint. Patients may present in the acute or chronic setting with radioulnar instability as manifested by persistent or new forearm discomfort and wrist and elbow pain. Reconstruction of the interosseous membrane has been described to restore longitudinal forearm stability. We describe reconstruction of the central band of the interosseous membrane with a bone-patellar tendon-bone graft. This procedure may be carried out in conjunction with radial head fixation or replacement and TFCC repair in the acute setting or ulnar shortening osteotomy in late presenting cases.     

Effects of radial head excision and distal radial shortening on load-sharing in cadaver forearms

BACKGROUND: The present study was performed to measure changes in radioulnar load-sharing in the cadaveric forearm following two orthopaedic surgical procedures that often have varying results: radial head excision and distal radial shortening. A better understanding of the biomechanical consequences of those procedures could aid surgeons in obtaining a more satisfactory clinical outcome. METHODS: Miniature load-cells were inserted into the proximal part of the radius and the distal part of the ulna in twenty fresh-frozen cadaveric forearms. Load-cell forces, radial head displacement relative to the capitellum, and local tension within the central band of the interosseous membrane were measured simultaneously as the wrist was loaded to 133.5 N in neutral pronation-supination and neutral radioulnar deviation. Testing was repeated after incremental distal radial shortening and after removal of the radial head. RESULTS: With the elbow flexed to 90 degrees and in valgus alignment (the radial head in contact with the capitellum), the mean force in the distal part of the ulna was 7.1% of the applied wrist force and the mean force in the interosseous membrane was 4.0%. With the elbow in varus alignment (a mean initial gap of 1.97 mm between the radial head and the capitellum), the respective mean values were 27.9% and 51.2%. After excision of the radial head, the mean force in the distal part of the ulna increased to 42.4% of the applied wrist force and the mean force in the interosseous membrane increased to 58.8%, in both varus and valgus elbow alignment. The mean distal ulnar force increased with progressive distal radial shortening in both varus and valgus elbow alignment; after 6 mm of radial shortening, the distal ulnar force averaged 92.4% (in varus alignment) and 60.9% (in valgus alignment). Equal distal load-sharing between the radius and ulna occurred after approximately 5 mm of radial shortening with the elbow in valgus alignment and after approximately 2 mm of radial shortening with the elbow in varus alignment. In valgus alignment, the force in the interosseous membrane was negligible after all degrees of radial shortening; in varus alignment, the mean force in the interosseous membrane decreased from 51.2% (0 mm of distal radial shortening) to 0% (6 mm of distal radial shortening) because of progressive slackening of the interosseous membrane. CONCLUSIONS: Radial head excision shifted the applied wrist force that normally would be transmitted to the elbow, through radial head-capitellar contact, to the interosseous membrane. The resulting proximal radial displacement created an ulnar-positive wrist and increased distal ulnar loading. Radial shortening and ulnar lengthening procedures have been designed to shift the applied wrist force from the distal part of the radius to the distal part of the ulna; it is commonly assumed that these procedures have equivalent biomechanical effects. We found that radial shortening resulted in slackening of the interosseous membrane, thereby negating its ability to transmit load through the forearm. Slackening of the interosseous membrane would not be expected with distal ulnar lengthening procedures. CLINICAL RELEVANCE: When the radial head has been fractured or excised, the mechanical status of the interosseous membrane is critical to the load-sharing process. If the interosseous membrane remains intact, distal ulnar loads will be limited to less than half of the applied wrist force; if the interosseous membrane has been damaged, nearly the entire applied wrist force will be shifted to the ulna. The amount of radial shortening or ulnar lengthening performed at the time of surgery during joint-leveling procedures has been largely empirical. We found that distal ulnar load increased by approximately 10% for each millimeter of radial shortening.     

Diagnosis and treatment of longitudinal instability of the forearm

Radio-ulnar dissociation can result from high-injury trauma that the compressive forces traverse the wrist forearm and elbow. This injury can be thought of as an "unhappy triad" of radial head fracture, triangular fibrocartilage complex failure, and a tear of the interosseous membrane. The radius is the primary stabilizer of the forearm with the forearm interosseous membrane enabling load sharing between the radius and the ulna. The central one-third of the interosseous membrane is 3 times stronger than the membranous portion and approaches the strength of the anterior cruciate ligament for determining interosseous membrane injury. Imaging studies with proven diagnostic efficacy include magnetic resonance imaging and ultrasound. Surgical treatment should be considered when circumstances imply longitudinal instability of the forearm. Surgical treatment includes open reduction/internal fixation or prosthetic replacement of the radial head as well as repair of the disrupted triangular fibrocartilage complex. Successful treatment of radioulnar dissociation is predicated on early diagnosis of the condition.     

Reconstruction of essex-lopresti injury of the forearm: technical note

Longitudinal instability of the forearm resulting from an Essex-Lopresti injury is a surgical challenge, and no technique has yet met universal success. A new technique is presented here consisting of reconstruction of the radial head, leveling of the distal radioulnar joint, reconstruction of the central band of the interosseous membrane by using a pronator teres rerouting technique, and finally repair of the triangular fibrocartilage complex. It is hoped that by addressing all of the contributing longitudinal stabilizing structures, the longitudinal instability of the forearm will be controlled. The technique is challenging and requires much surgical experience.     

MRI在桡骨头骨折合并前臂骨间膜损伤中的诊断价值

目的：探讨MRI在桡骨头骨折合并前臂骨间膜损伤中的诊断价值。方法：收集2011年12月至2012年12月间所有桡骨头骨折患者26例,其中男15例,女11例;年龄21～53岁,平均37.6岁。所有患者于伤后72 h内就诊,伤后1周内行伤侧尺桡骨全长X线片、伤侧CT（必要时加三维重建）及MRI检查（包括肘及腕关节）.观察前臂骨间膜在磁共振上的表现（有无损伤、损伤的部位及损伤的程度）,桡骨头骨折的损伤程度,比较两者的相关性。结果：桡骨头骨折Mason Ⅰ-Ⅲ型均可伴有前臂骨间膜损伤,桡骨头骨折程度与前臂骨间膜损伤程度成正相关（P〈0.05）.结论：桡骨头骨折伴前臂骨间膜可疑损伤时,有必要进行前臂MRI检查,明确骨间膜有无损伤及损伤程度,根据骨间膜损伤的情况对桡骨小头骨折选择正确的治疗方法,只有这样才能有利于肘关节和前臂功能的恢复。     

Radius pull test: predictor of longitudinal forearm instability

BACKGROUND: Longitudinal instability of the forearm (the Essex-Lopresti lesion) following radial head excision may be difficult to detect. This cadaveric study examines a stress test that can be performed in the operating room to identify injury to the ligamentous structures of the forearm. METHODS: Twelve cadaveric upper extremities were randomized into two groups and underwent radial head resection. Group 1 underwent sequential transection of the triangular fibrocartilage complex and the interosseous membrane. Group 2 underwent sequential transection of the interosseous membrane and the triangular fibrocartilage complex. Ulnar variance and radial migration were examined with use of fluoroscopy of the wrist before, during, and after the application of a 9.1-kg load via longitudinal traction on the proximal part of the radius. RESULTS: Group 1 demonstrated no significant changes in proximal radial migration with load (compared with the findings after radial head resection alone) after transection of the triangular fibrocartilage complex. However, Group 2 demonstrated significant changes in proximal radial migration with load after transection of the interosseous membrane (p = 0.03; median, 3.5 mm). In both groups, transection of both the triangular fibrocartilage complex and the interosseous membrane resulted in significant changes in proximal radial migration with load (p = 0.001; median, 9.5 mm). When the load was removed, specimens were ulnar positive (median, 3.0 mm), with no specimen returning to the preload position of ulnar variance (p = 0.001). CONCLUSION: After radial head resection, 3 mm of proximal radial migration with longitudinal traction indicated disruption of the interosseous membrane. In all specimens, proximal radial migration of > or =6 mm with load indicated gross longitudinal instability with disruption of all ligamentous structures of the forearm.     

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.     

Mechanisms of load transfer in the cadaver forearm: role of the interosseous membrane

Forces transmitted through the distal ulna and proximal radius, relative motion between the radial head and capitellum, and measurements of tissue strain and local fiber tension within the central band of the interosseous membrane were recorded as cadaveric forearms were loaded axially through the wrist. With the elbow in valgus alignment (the radial head in direct contact with the capitellum), an average of 93% of force applied to the wrist was transferred directly through the radius to the elbow with no appreciable load transfer through the interosseous membrane. With varus alignment (initial gap between the radial head and capitellum) load applied to the wrist displaced the radius proximally an average of 1.1 mm until radial head contact occurred at a mean applied wrist force of 89.0 N. Proximal displacement of the radius generated strain in the central band of the interosseous membrane and created a more ulnar positive wrist, which in turn increased distal ulnar loading; distal ulnar force averaged 19% and interosseous membrane averaged 54% of applied wrist force. Distal ulnar loading was unaffected by 25 degrees wrist flexion-extension or by 20 degrees of radioulnar deviation. With 40 degrees ulnar deviation, mean distal ulnar forces were 18% and 48% of applied wrist force for valgus and varus elbow alignments, respectively. Mean load-sharing percentages at the wrist and elbow were not significantly different between 222. 5 N and 133.5 N of applied force for any wrist position and were unaffected by the angle of elbow flexion.     

Ultrasonography for the evaluation of forearm interosseous membrane disruption in a cadaver model

Recognition of interosseous membrane disruption associated with radial head injury and Essex-Lopresti injury is important, especially if radial head excision is contemplated. Because a widely accepted method to diagnose interosseous membrane disruption does not exist, we evaluated the accuracy of ultrasonography to diagnose this injury in a cadaver model. Nine pairs of cadaver forearms were randomized into 2 groups. The central third of the interosseous membrane of forearms of group 1 was cut, whereas it was visualized but not cut in group 2. A dynamic ultrasound examination was performed to determine interosseous membrane integrity, and static images were made. The static images were evaluated by 2 other radiologists and interpretations were recorded. One radiologist incorrectly interpreted 1 pair of forearms; the other 2 radiologists were 100% accurate. The accuracy of ultrasonography in detecting interosseous injuries was 96% with our methods.     

Reconstruction of Posterior Interosseous Nerve Injury Following Biceps Tendon Repair: Case Report and Cadaveric Study

Surgical repair of distal biceps tendon rupture is a technically challenging procedure that has the potential for devastating and permanently disabling complications. We report two cases of posterior interosseous nerve (PIN) injury following successful biceps tendon repair utilizing both the single-incision and two-incision approaches. We also describe our technique of posterior interosseous nerve repair using a medial antebrachial cutaneous nerve graft (MABC) and a new approach to the terminal branches of the posterior interosseous nerve that makes this reconstruction possible. Finally, we advocate consideration for identification of the posterior interosseous nerve prior to reattachment of the biceps tendon to the radial tuberosity.     

Chronic post-traumatic radial head dislocation associated with dissociation of distal radio-ulnar joint: a case report

We present an unusual case of an isolated interosseous membrane disruption of the forearm without any fracture pattern. Dislocation of both radial head and distal radio-ulnar joint was presented. Open reduction of the radial head with radial neck shortening osteotomy was performed.     

Ultrasound diagnosis and surgical pathology of the torn interosseous membrane in forearm fractures/dislocations

Ultrasound was used to effectively diagnose and precisely locate a torn interosseous membrane in 2 forearm fracture/dislocations. The ultrasound appearance of the torn interosseous membrane in cadavers and in the fractures/dislocations shows disruption of the anterior and posterior layers in midsubstance or adjacent to the radius or ulna. The surgical pathology in 3 forearm fractures/dislocations (2 Galeazzi injuries and 1 Essex-Lopresti injury) shows a longitudinal oblique tear of the interosseous membrane, parallel to its major palmar fibers, oriented from proximal radial to the distal ulnar. After ultrasound diagnosis, we demonstrated the feasibility of direct primary repair of the torn interosseous membrane associated with the Essex-Lopresti injury in a clinical case.     

Essex-Lopresti损伤的生物力学研究

目的 探讨Essex-Lopresti损伤的生物力学机制,为诊治Essex-Lopresti损伤提供生物力学依据.方法 取12具成人新鲜冰冻上肢标本予以处理,先将12具标本("完整状态组")分别在旋前位、旋后位及中立位三种状态下把标本夹持固定于MTS 858生物材料试验机上进行力学测试,恒定加载100 N的压力负荷,每种状态持续30 s后减载.随后将12具标本随机分为2组,6具切除桡骨头为"切头留膜组";另6具切断前臂骨间膜(interosseous membrane,IOM)中间腱性部分为"留头切膜组".每组按上述方法进行生物力学测试.最后将所有标本均切除桡骨头并切断IOM("切头切膜组")按上述方法进行生物力学测试.结果 前臂旋转状态或单纯切断IOM对桡骨纵向位移无影响.单纯切除桡骨头或联合切断IOM和切除桡骨头增加了桡骨的纵向位移.前臂中立位时的桡骨刚度比前臂旋前位大,但比前臂旋后位小.单纯切断IOM对桡骨刚度没有影响,单纯切除桡骨头或联合切断IOM和切除桡骨头则会使桡骨刚度下降.结论 桡骨头骨折合并IOM损伤可能是Essex-Lopresti损伤产生并发症的重要原因,其中桡骨头骨折是Essex-Lopresti损伤主要原因,而IOM损伤是次要原因.桡骨头切除后IOM是维持前臂纵向稳定的主要结构.     

Essex-Lopresti损伤的生物力学研究

目的 探讨Essex-Lopresti损伤的生物力学机制,为诊治Essex-Lopresti损伤提供生物力学依据.方法 取12具成人新鲜冰冻上肢标本予以处理,先将12具标本("完整状态组")分别在旋前位、旋后位及中立位三种状态下把标本夹持固定于MTS 858生物材料试验机上进行力学测试,恒定加载100 N的压力负荷,每种状态持续30 s后减载.随后将12具标本随机分为2组,6具切除桡骨头为"切头留膜组";另6具切断前臂骨间膜(interosseous membrane,IOM)中间腱性部分为"留头切膜组".每组按上述方法进行生物力学测试.最后将所有标本均切除桡骨头并切断IOM("切头切膜组")按上述方法进行生物力学测试.结果 前臂旋转状态或单纯切断IOM对桡骨纵向位移无影响.单纯切除桡骨头或联合切断IOM和切除桡骨头增加了桡骨的纵向位移.前臂中立位时的桡骨刚度比前臂旋前位大,但比前臂旋后位小.单纯切断IOM对桡骨刚度没有影响,单纯切除桡骨头或联合切断IOM和切除桡骨头则会使桡骨刚度下降.结论 桡骨头骨折合并IOM损伤可能是Essex-Lopresti损伤产生并发症的重要原因,其中桡骨头骨折是Essex-Lopresti损伤主要原因,而IOM损伤是次要原因.桡骨头切除后IOM是维持前臂纵向稳定的主要结构.

Abstract：

Objective To study the biomechanical mechanism of Essex-Lopresti injury, and provide biomechanical basis for diagnosis and treatment of Essex-Lopresti injury. Methods Twelve fresh frozen adult upper limbs were addressed. Firstly, 12 samples ("complete state group") were loaded 100 N of a compressive force lasting 30 seconds in pronation, supination and neutral position on the mechanical testing machine. Secondly, 12 specimens were randomly divided into 2 groups. In the group named resection of radial head, the radial head was removed and interosseous membrane (IOM)was intact. In the group named the section of interosseous membrane, IOM was cut off. Finally, the radial head were removed and IOM was cut off in all specimens. The group was named as resection of radial head and IOM. Each sample was tested according to the method as described. Results The forearm rotation or single excision of the IOM had no effect on radial longitudinal displacement. Simple radial head excision or resection of the IOM and the radial head increased the vertical displacement of the radius. The radial stiffness had a gradual decline in forearm supination, neutral position and pronation. Simple excision IOM has no effect on the radial stiffness. The radial stiffness had decreased under the condition of excision of radial head or resection of the IOM and the radial head. Conclusion These in vitro measurements validate that the radial head fracture with IOM injury may be important reason for complications of the Essex-Lopresti injury. Radial head fracture play a key role for Essex-Lopresti injury and the injury of IOM is secondary cause. IOM is responsible for maintaining the vertical stability of the forearm after radial head resection.     

Experimental study on rotation of the forearm--functional anatomy of the interosseous membrane

In an attempt to elucidate the function of the interosseous membrane of the forearm, the anatomy of the interosseous membrane and the kinematics of the forearm during pro-supine movement were studied. Results and Conclusions; The rotation axis coincides with the line drawn from the ulnar head to the radial head. The motion of the radius is an arc of a circle about it. At one-fourth the length of the forearm from the distal end, the axis coincides with the edge of the interosseous border of the ulna. The most prominent fibers of the interosseous membrane are those being attached to this part. Therefore, tension of these most prominent fibers is constant. The interosseous membrane of the forearm apparently shows a structure meeting the needs for stabilizing two bones, transmitting thrusts and giving the origin to the muscles without interfering with the pro-supine movement of the forearm.     

The Essex-Lopresti lesion: a variant with a bony distal radioulnar joint injury

The Essex-Lopresti lesion is an unusual injury, consisting of a radial head or neck fracture, distal radioulnar joint (DRUJ) injury and interosseous membrane rupture. To date, all reported Essex-Lopresti lesions have consisted of soft tissue injuries at the DRUJ. We present a case of an Essex-Lopresti lesion with a bony variant, in which the DRUJ injury consisted of an ulnar head fracture associated with radial head fracture and acute proximal migration of the radius. The management involved plating of the ulnar head fracture and titanium replacement of the radial head.     

Elbow Biomechanics,Radiocapitellar Joint Pressure,and Interosseous Membrane Strain Before and After Radial Head Arthroplasty

Complex radial head fracture and elbow instability can be treated with radial head arthroplasty. Good clinical results have been described after this surgical treatment. However, the revision and complication rate reported in the literature is concerning. This might be due to altered kinematics after radial head arthroplasty. Eight human native elbows were examined with dynamic radiostereometric analysis and compared with a radial head arthroplasty. Translations of the radial head in the x-, y-, and z-directions relative to the humerus and the ulna were measured. The radiocapitellar joint pressure was measured using a pressure sensor. The tension within the interosseous membrane was measured using a custom-made strain gauge. After radial head arthroplasty, the radial head was displaced approximately 1.8 mm medially and 1.4 mm distally at the starting point. During unloaded flexion motion the difference in all translations between the native radial head and the radial head arthroplasty was less than 1 mm (95% confidence interval [CI] ± 0.5 mm) (p = 0.001). With loading the difference was less than 1.5 mm (95% CI ± 1.5 mm) (p = 0.001). The mean difference in radiocapitellar joint contact pressure was less than 0.30 MPa (95% CI ± 0.40 MPa) (p = 0.001) during unloaded flexion motion. There were only submillimetre kinematic changes and small changes in joint pressure and interosseous membrane tension after the insertion of a radial head arthroplasty in an experimental setting. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:510–522, 2020     

The anatomy of the proximal radioulnar joint

This study is an anatomic investigation to define the architecture of and the stabilizing structures for the proximal radioulnar joint. Ten fresh-frozen cadaver elbows were dissected. Measurements of the radial head, annular ligament, radial fossa of the ulna, and interosseous membrane were made and were correlated to clinical observations of elbow stability. Sequential transection of the soft tissue constraints of the proximal radioulnar joint demonstrated the annular ligament and the central band of the interosseous membrane to be the main stabilizers in pronation and the central band to be the significant stabilizer in supination. Eccentric loading of the joint was noted on anterior-posterior shifting of the radial head during forearm rotation. The clinical relevance of these observations in relation to radial head dislocation, fracture pattern, and elbow stability is discussed.