We measured the tension in the interosseous membrane in six cadaveric forearms using an in vitro forearm testing system with the native radial head, after excision of the radial head and after metallic radial head replacement. The tension almost doubled after excision of the radial head during simulated rotation of the forearm (p = 0.007). There was no significant difference in tension in the interosseous membrane between the native and radial head replacement states (p = 0.09). Maximal tension occurred in neutral rotation with both the native and the replaced radial head, but in pronation if the radial head was excised. Under an increasing axial load and with the forearm in a fixed position, the rate of increase in tension in the interosseous membrane was greater when the radial head was excised than for the native radial head or replacement states (p = 0.02). As there was no difference in tension between the native and radial head replacement states, a radial head replacement should provide a normal healing environment for the interosseous membrane after injury or following its reconstruction. Load sharing between the radius and ulna becomes normal after radial head Replacement. As excision of the radial head significantly increased the tension in the interosseous membrane it may potentially lead to its attritional failure over time. Cite this article: Bone Joint J 2013;95-B:1383–7

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

Introduction. The distal part of the interosseous membrane (IM) may contribute to ankle joint stability and therefore partly explain the results of a study that reported no difference in outcome in patients with low Weber C fractures treated with or without a syndesmotic screw. The aim of the current study was to compare the strength of the IM to the interosseous ligament (IL). Method. Six paired cadaveric lower extremities were stripped, leaving only the IM and the IL intact. The tibia was fixed and a load was applied via a steel plate to the lateral surface of the fibula to displace it with respect to the tibia along the line of the fibers of the IM and IL. In group one the interosseous ligament was sectioned and the interosseous membrane was mechanically tested until failure. In group two, the interosseous membrane was sectioned and the interosseous ligament was tested. Results. The interosseous membrane was 30% stronger than the interosseous ligament (1040 ± 183 N versus 798 ± 322 N, respectively; mean ± SD). Conclusion. The current biomechanical study found that the IM was 30% stronger than the IL. The interosseous membrane has considerable strength and may play a role in ankle stability

In severe forearm injuries, the diagnosis of disruption of the interosseous membrane is frequently delayed and sometimes missed, giving difficulties in the salvage of forearm stability. We studied the structure and function of the interosseous membrane in 11 cadaver preparations, using mechanical and histological analysis. Seven of the specimens tested in uniaxial tension sustained a mid-substance tear of the central band of the membrane at a mean peak load of 1038 ± 308 N. The axial stiffness was 190 ± 44 N/mm with elongation to failure of 10.34 ± 2.46 mm. These results provide criteria for the evaluation of reconstructive methods. A preliminary clinical investigation of the use of ultrasound suggests that this may be of value in the screening of patients with complex fractures of the forearm, and for investigating the natural history of tears of the interosseous membrane

Purpose of the study: The slightest alteration of the antebrachial anatomic configuration, which constitutes a complex and precise biomechanical system, yields a limitation in pronosupination. Unlike the metaphysical region, little is known about rotational malunion involving the radial shaft. Kasten et all demonstrated in 30 cases that a rotational malunion of the radial shaft leads to significant loss in the pronosupination arc. If the proximal and distal radioulnar joints are intact, the interosseous membrane (IOM) probably plays an important role in this limitation. Material and methods: The purpose of our study was to evaluate the impact of releasing the IOM on the pro-nosupination arc in an experimental model with a rotational malunion of the radial shaft inducing pronation. Results: The study involved eight cadaver forearms free of all muscle structures and devoid of prior trauma. After stabilizing the elbow at 90°, the upper limb was fixed on a metal frame used as the reference to measure pronosupination. For each specimen, motion was measured initially, after osteotomy of the radius shaft to induce pronation then associated with longitudinal section of the IOM. A midshaft transverse osteotomy induced 78±7 pronation on average and was fixed with a DCP. Discussion: The mean pronosupination arc was initially 175 in our population (81 pronation, 94 supination). After the creating the rotational malunion, this arc decreased significantly to 126 (SD. p> 0.05) (99 pronation, 27 supination). Release of the IOM increased this arc significantly from 27 to 153 (SD, p> 0.05) (105 pronation, 48supination). Conclusion: Our study confirms the impact of rotational malunion on the pronosupination arc and shows the positive effect of releasing the IOM. Suppression of the IOM leads to a simpler biomechanics for the antebrachial system, allowing greater mobility of the bone one over the other. There are several clinical applications of this observation for the correction of shaft malunion of the antebrachial bones, but also certain corrective osteotomies for malpositions in the neurological patient

We report the results of performing a pronating osteotomy of the radius, coupled with other soft-tissue procedures, as part of an upper limb functional surgery programme in tetraplegic patients with supination contractures. In total 12 patients were reviewed with a mean follow-up period of 60 months (12 to 109). Pre-operatively, passive movement ranged from a mean of 19.2° pronation (−70° to 80°) to 95.8° supination (80° to 140°). A pronating osteotomy of the radius was then performed with release of the interosseous membrane. Extension of the elbow was restored postoperatively in 11 patients, with key-pinch reconstruction in nine. At the final follow-up every patient could stabilise their hand in pronation, with a mean active range of movement of 79.6° (60° to 90°) in pronation and 50.4° (0° to 90°) in supination. No complications were observed. The mean strength of extension of the elbow was 2.7 (2 to 3) MRC grading. Pronating osteotomy stabilises the hand in pronation while preserving supination, if a complete release of the interosseous membrane is also performed. This technique fits well into surgical programmes for enhancing upper limb function

Purpose of the study: Investigate the longitudinal stability and instability of the forearm. Material and methods: The interosseous membranes of 30 formol-treated forearms were dissected under 4-fold magnification and translumination. The radial and ulnar heads wee resected to eliminate the two radioulnar articulations before performing sequential cuts to identify the different networks of the interosseous membrane. The ulna was maintained in a fixed position allowing proximal and distal displacement of the radius. We studied the medial border of 100 radii, noting the bony eminences and their relations with the configuration of the membrane. Cases of neglected fractures of the radial cup without injury to the distal radioulnar joint and cases of polyarthritis treated by double resection radioulnar and Sauvé-Kapandji) presenting good longitudinal stability were studied. The possiblity of using the extensor indicis for primary reinforcement of the interosseous membrane was studied on cadaver specimens. Applied to an acute case of Essex-Lopresti syndrome, this original technique provided good intraoperative stability. Results: The fibers of the interosseous membrane design two planes, an anterior and a posterior plane. The anterior fibrrs descend distally and medially from the radius. They can be divided into proximal (horizontal) descending fibers, intermediary (short oblique) descending fibers, and distal (long oblique) descending fibers. The posterior fibers rise proximally and medially from the radius to reach the ulna. They form two planes: proximal ascending (short oblique) fibers and distal (long oblique) ascending fibers which are inconstant. These planes are in relation with the origin of the extrinsic wrist extensors. The main fibers are: the intermediary descending fibers and the proximal ascending fibers. They insert on the interosseous tubercle of the radius, a constant eminence situated on the medial border of the radius 8.4 cm from the elbow. The thre groups of descending fibers limit proximal translation of the radius. The proximal fibers can limit excessive distal translation. The proximal and distal ascending fibers limit distal translation of the radius. A full thicknes tear of the anterior plane is necessary to achieve proximal displacement. Longitudinal stability is maintained in neglected fractures of the distal without rupture of the interosseous membrane and in operated polyarthritis with resection of the two radioulnar joints. Conclusion: The fibers of the interosseous membrane describe two planes where the fibers run in opposing directions. Each plane limits radial displacement in a different direction. The ideal reconstruction would restore the two planes, but it is essential to reconstruct at least the intermediary descending fibers and the proximal ascending fibers. However, in routine practice, translation of the radius is generally proximal, so reconstruction of the middle segment appears to be sufficient if it associated with a reinforcement transfer of the extensor indicis to the proximal radius

Introduction. Posterolateral tibial plateau fractures account for 7 % of all proximal tibial fractures. Their fixation often requires posterolateral buttress plating. Approaches for the posterolateral corner are not extensile beyond the perforation of the anterior tibial artery through the interosseous membrane. This study aims to provide accurate data about the inferior limit of dissection by providing measurements of the anterior tibial artery from the lateral joint line as it pierces the interosseous membrane. Materials and Methods. Forty unpaired adult lower limbs cadavers were used. The posterolateral approach to the proximal tibia was performed as described by Frosch et al. Perpendicular measurements were made from the posterior limit of the articular surface of the lateral tibial plateau and fibula head to the perforation of the anterior tibial artery through the interosseous membrane. Results. The anterior tibial artery coursed through the interosseous membrane at 46.3 +/− 9.0 mm (range 27–62 mm) distal to the lateral tibial plateau and 35.7 +/− 9.0 mm (range 17–50 mm) distal to the fibula head. There was no significant difference between right or left sided knees. Discussion. This cadaveric study demonstrates the safe zone (min 27 mm, mean 45mm) up to which distal exposure can be performed for fracture manipulation and safe application of a buttress plate for displaced posterorlateral tibial plateau fractures. Evidence demonstrates quality of reduction correlates with clinical outcome and the surgeon can expect to be able to use a small fragment buttress plate of up to 45mm as this is the mean

In this retrospective cohort study, we analysed the incidence and functional outcome of a distal tibiofibular synostosis. Patients with an isolated AO type 44-B or C fracture of the ankle who underwent surgical treatment between 1995 and 2007 were invited for clinical and radiological review. The American Orthopaedic Foot and Ankle Society score, the American Academy of Orthopaedic Surgeons score and a visual analogue score for pain were used to assess outcome. A total of 274 patients were available; the mean follow-up was 9.7 years (8 to 18). The extent of any calcification or synostosis at the level of the distal interosseous membrane or syndesmosis on the contemporary radiographs was defined as: no or minor calcifications (group 1), severe calcification (group 2), or complete synostosis (group 3). . A total of 222 (81%) patients were in group 1, 37 (14%) in group 2 and 15 (5%) in group 3. There was no significant difference in incidence between AO type 44-B and type 44-C fractures (p = 0.89). Severe calcification or synostosis occurred in 21 patients (19%) in whom a syndesmotic screw was used and in 31 (19%) in whom a syndesmotic screw was not used.(p = 0.70). No significant differences were found between the groups except for a greater reduction in mean dorsiflexion in group 2 (p = 0.004). . This is the largest study on distal tibiofibular synostosis, and we found that a synostosis is a frequent complication of surgery for a fracture of the ankle. Although it theoretically impairs the range of movement of the ankle, it did not affect the outcome. . Our findings suggest that synostosis of the distal tibiofibular syndesmosis in general does not warrant treatment. Cite this article: Bone Joint J 2015;97-B:945–9

Nonunion of the tibia associated with bone loss, previous infection, obliteration of the intramedullary canal or located in the distal metaphysis poses a challenge to the surgeon and significant morbidity to patients. We retrospectively reviewed the records of 24 patients who were treated by central bone grafting and compared them to those of 20 who were treated with a traditional posterolateral graft. Central bone grafting entails a lateral approach, anterior to the fibula and interosseous membrane which is used to create a central space filled with cancellous iliac crest autograft. Upon consolidation, a tibiofibular synostosis is formed that is strong enough for weight-bearing. This procedure has advantages over other methods of treatment for selected nonunions. Of the 24 patients with central bone grafting, 23 went on to radiographic and clinical union without further intervention. All healed within a mean of 20 weeks (10 to 48). No further bone grafts were required, and few complications were encountered. These results were comparable to those of the 20 patients who underwent posterolateral bone grafting who united at a mean of 31.3 weeks (16 to 60) but one of whom required below-knee amputation for intractable sepsis. Central bone grafting is a safe and effective treatment for difficult nonunions of the tibia

The integrity of the periosteum and the interosseous membrane determine the stability of fractures of the distal ulna; this is indicated by the initial displacement. In fractures displaced by less than 50% the periosteum and interosseous membranes are largely intact; these fractures are stable and require only below-elbow immobilisation for protection and relief of pain. In fractures displaced by more than 50% the membranes are disrupted; these fractures are unstable and require above-elbow immobilisation for stability. As most fractures are displaced by less than 50%, immobilisation of the elbow, which significantly increases morbidity, is usually unnecessary. I report the results of a cadaveric study on the pathomechanics of fractures of the distal ulna, and of a prospective clinical trial in which the type of cast used for immobilisation was determined by the stability of the fracture

The Essex-Lopresti injury is rare. It consists of fracture of the head of the radius, rupture of the interosseous membrane and disruption of the distal radioulnar joint. The injury is often missed because attention is directed towards the fracture of the head of the radius. We present a series of 12 patients with a mean age of 44.9 years (26 to 54), 11 of whom were treated surgically at a mean of 4.6 months (1 to 16) after injury and the other after 18 years. They were followed up for a mean of 29.2 months (2 to 69). Ten patients had additional injuries to the forearm or wrist, which made diagnosis more difficult. Replacement of the head of the radius was carried out in ten patients and the Sauve-Kapandji procedure in three. Patients were assessed using standard outcome scores. The mean post-operative Disabilities of the Arm, Shoulder and Hand score was 55 (37 to 83), the mean Morrey Elbow Performance score was 72.2 (39 to 92) and the mean Mayo wrist score was 61.3 (35 to 80). The mean grip strength was 68.5% (39.6% to 91.3%) of the unaffected wrist. Most of the patients (10 of 12) were satisfied with their operation and in 11 the pain was relieved. When treating the chronic Essex-Lopresti injury, we recommend accurate realignment of the radius and ulna and replacement of the head of the radius. If this fails a Sauve-Kapandji procedure to arthrodese the distal radioulnar joint should be undertaken to stabilise the forearm while maintaining mobility

Syndesmotic stability in ankle fractures is usually assessed by pulling on the fibula with a bone hook in the coronal plane (“hook test”). Our clinical observations have suggested that instability may be more marked in the sagittal plane. Our aim was to compare movement at the tibio-fibular syndesmosis in the sagittal and coronal planes after sequential ligament division in a cadaver model. Seven specimens were used. A blinded subject was asked to perform the hook test both in the sagittal and coronal planes. Movement was assessed by measuring the displacement of parallel k-wires three consecutive times. In all specimens, the anterior tibio-fibular, interosseous and posterior tibio-fibular ligaments were sequentially divided and movement tested. In three specimens the deltoid ligament was then divided and the interosseous membrane in another three. After division of all three syndesmosis ligaments the mean displacement was 8.8mm (±3.9) in the sagittal plane and 1.5mm (±0.4) in the coronal plane. When the deltoid ligament was then divided, the displacement increased to 11.7mm (±2.4) and 3.2mm (±0.5) respectively. When the interosseous membrane was divided the measurements were 12.7mm (±4) and 3.1mm (±1.5). We conclude that distal tibio-fibular instability should be assessed in the sagittal plane

This novel modification of the posterior approach allows a low hazard exposure and easier surgery to the radial head. Methods and Materials: The most commonly used approaches are from the lateral aspect. The limitations of this approach in particular for radial head replacement is that it is a tight exposure, there is a risk of damage to the posterior interosseous nerve and there is always a difficulty in dislocation due to the presence of the interosseous membrane. The posterolateral approach to the proximal radius and ulna was described by Boyd, Gordon and Thompson. This approach avoids damage to the posterior interosseous nerve but the annular ligament requires incision and repair. Approach: Position the forearm in pronation aligning the ulnar styloid with lateral epicondyle of the humerus. A tencentimetre long incision is then made on the lateral border of the ulna exposing deep fascia. Following this a 1cm flap of fascia is left on the ulna and anconeus is lifted off the bone. This exposes underlying radial head, annular ligament and interosseous membrane. After identifying the ulnar insertion of annular ligament a 0.5 cm bone is osteotomised with annular ligament attached from the supinator tuberosity. The radial head osteotomy is performed with the radial head in pronation to align it with shaft of radius using specially designed jig. Osteotomy of the radial head has to be at right angles to the axis of the forearm. This is a line between centre of the radial neck to the ulnar styloid process. Radial head can now be subluxed out of the wound and preparing for a replacement. The trial prosthetic radial head is then inserted and reduced. The bone fragment with annular ligament attachment is then reduced back into the original slot. This allows one to judge the size of prosthetic radial head if ligament is too tight a small diameter implant is required. The bone fragment is reattached using especially devised washer with, wire holes and a 2mm AO screw. Results: This approach is easier, safer and reproducible. When compared to lateral approach it provides an easier access and excellent stability in radial head replacement. We recommend this approach for radial head replacements and difficult trauma cases

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. Cite this article: Bone Joint J 2014;96-B:1385–91

The Interosseous Membrane (IOM) of the forearm is made up of ligaments, which are involved in load balancing of the radioulnar joint and the shaft. Motion models of the forearm are necessary for planning orthopedic surgeries, such as osteotomies, which aim at solving limit of the range of motion or instabilities. However, existing models focus on a pure kinematic approach, omitting the physical properties of the ligaments, thus limiting the range of application by missing dynamical effects. We developed a model that takes into account the mechanical properties of the IOM. We simulated the pro-supination by creating an elastic coupling to the desired motion around the standard axis of rotation. We tested our model on a healthy subject, using CT-reconstructed bone models, and literature data for the ligaments. Multiple parameters, including forces of ligaments and positions of landmarks, are output for analysis. The length of the ligaments over pro-supination was in agreement with the literature. Their rest lengths must be recorded in future anatomical studies. The IOM helps in maintaining the contact with cartilage, except in late pronation. Scarring of the central band increases the force generated along the axis of rotation toward the wrist, while scarring of the proximal part does the opposite in pronation. In contrast to kinematic models, the proposed model is helpful to study the effect of physical properties of the IOM, such scarring, on the forearm motion. Future work will be to apply our model to pathological cases, and to compare to clinical observations

M. Soubeyrand, G. Ciais, V. Wassermann, I. Kalouche, D. Biau, C. Dumontier, O. Gagey.The intra-operative radius joystick test to diagnose complete disruption of the interosseous membrane. J Bone Joint Surg Br 2011 93-B: 1389-1394

Background. Ankle fractures are often associated with ligamentous injuries of the distal tibiofibular syndesmosis, the deltoid ligament and are predictive of ankle instability, early joint degeneration and long-term ankle dysfunction. Detection of ligamentous injuries and the need for treatment remain subject of ongoing debate. In the classic article of Boden it was made clear that injuries of the syndesmotic ligaments were of no importance in the absence of a deltoid ligament rupture. Even in the presence of a deltoid ligament rupture, the interosseous membrane withstood lateralization of the fibula in fractures up to 4.5mm above the ankle joint. Generally, syndesmotic ligamentous injuries are treated operatively by temporary fixation performed with positioning screws. But do syndesmotic injuries need to be treated operatively at all?. Methods. The purpose of this biomechanical cadaveric study was to investigate the relative movements of the tibia and fibula, under normal physiological conditions and after sequential sectioning of the syndesmotic ligaments. Ten fresh-frozen below-knee human cadaveric specimens were tested under normal physiological loading conditions. Axial loads of 50 Newton (N) and 700N were provided in an intact state and after sequential sectioning of the following ligaments: anterior-inferior tibiofibular (AITFL), posterior-inferior tibiofibular (PITFL), interosseous (IOL), and whole deltoid (DL). In each condition the specimens were tested in neutral position, 10 degrees of dorsiflexion, 30 degrees of plantar flexion, 10 degrees of inversion, 5 degrees of eversion, and externally rotated up to 10Nm torque. Finally, after sectioning of the deltoid ligament, we triangulated Boden's classic findings with modern instruments. We hypothesized that only after sectioning of the deltoid ligament; the lateralization of the talus will push the fibula away from the tibia. Results. During dorsiflexion and external rotation the ankle syndesmosis widened, and the fibula externally rotated after sequential sectioning of the syndesmotic ligaments. After the AITFL was sectioned the fibula starts rotating externally. However, the external rotation of the fibula significantly reduced when the external rotation torque was combined with axial loading up to 700N as compared to the external rotation torque alone. The most relative moments between the tibia and fibula were observed after the deltoid ligament was sectioned. Conclusion. Significant increases in movements of the fibula relative to the tibia occur when an external rotation torque is provided. However, axial pressure seemed to limit external rotation because of the bony congruence of the tibiotalar surface. The AITFL is necessary to prevent the fibula to rotate externally when the foot is rotating externally. The deltoid ligament is the main stabilizer of the ankle mortise

Nine children with chronic post-traumatic dislocation of the head of the radius were treated by an osteotomy of the ulna with over-correction of the angular deformity and with elongation of the bone. Satisfactory results were obtained in eight cases, the only poor outcome following a three-year delay between the initial injury and the reposition. The interosseous membrane of the forearm appeared to be the most important structure in maintaining the corrected position of the radial head

There are numerous causes of cavovarus feet, the most common of which are the hereditary motor and sensory peripheral neuropathies. Regardless of the underlying aetiology, cavovarus feet are caused by muscle imbalance. Often the imbalance is between a relatively strong tibialis posterior acting against a weaker peroneus brevis, and a relatively weak tibialis anterior being over powered by peroneus longus. Intrinsic muscle weakness and gastro-soleal tightness is common. After the failure of non-operative management, flexible deformity can be corrected with a combination of tendon transfers and osteotomies. Frequently surgical management of cavovarus feet involves a combination of calcaneal and first metatarsal osteotomies, peroneus longus to brevis transfer, transfer of tibialis posterior through the interosseous membrane to the dorsum of the foot, tendo-Achilles and plantar fascia lengthening and correction of toe deformities. The post-operative recovery is slow, but most patients achieve good functional results and report improvements in their activities of daily living