Ligamentoplasty of the forearm interosseous membrane using the semitendinosus tendon: anatomical study and surgical procedure

Missed Essex-Lopresti Injury-Development of a Combined Proximal and Distal Radio-Ulnar Joint Prosthesis as a Treatment Option and Proof of Concept

Essex-Lopresti injuries are characterized by injuries to the proximal radio-ulnar joint, the distal radio-ulnar joint, and the interosseous membrane. This can lead to osteoarthritis, impaction syndrome, or instability. If all three structures are injured and lead to instability, the situation is almost unmanageable and many times ends in a one-bone forearm. In this article, we demonstrate a new way to reconstruct the proximal and distal radio-ulnar joint with two patient-specific coupled prostheses. These have been developed with the biomechanical conditions of the forearm in mind, where there are very large forces between the bones. As a result, we are able to present a patient previously severely restricted in the use of his hand and arm via a splint that compressed the forearm, who is now able to perform everyday activities and even light sports, such as badminton, without pain.

The interosseous tuberosities of the forearm exist from 1-year-old: a pediatric radiological study describing the ages of appearance of the different forearm reliefs

PURPOSE

Interosseous tuberosities have been described in adults on the radial and ulnar sides. However, their presence at birth and their development during growth is still unknown. The objective of this work is to establish the age of onset of this tuberosity among a cohort of children aged 1-year-old or older.

METHODS

All anterior-posterior and lateral radiographs performed in our hospital during a consecutive period of 6 months were retrospectively analyzed. Exclusion criteria were: presence of a fracture, a tumor, an age higher than 16 years, radiograph not performed strictly from the front with supination or from the side. On the anterior-posterior radiograph, the presence of the following structures was sought: radial interosseous tuberosity and determination of its length and width; the appearance of the epiphyseal nucleus of the radial head, of the bicipital tuberosity, and of the distal epiphysis. On the lateral views, the presence of the following structures was sought: ulnar interosseous tuberosity and determination of its length and width; the appearance of the olecranon epiphyseal nucleus, and the distal epiphysis.

RESULTS

Over the review period, anterior-posterior and lateral radiographs were performed on 368 consecutive children. Finally, 179 patients were included in the radiographic analysis. The radial and ulnar interosseous tuberosities and bicipital tuberosity were present in all cases, from 1-year-old. Only the distal radial epiphysis began to appear at the age of one year, the others ossifying progressively during growth.

CONCLUSION

Tuberositas interossea ulnarii and radii exists, are present from 1-year-old and continue to develop during growth.

Acute Essex-Lopresti Syndrome: About a Case of Brachioradialis Tendon Transfer

Background  The classic treatment for acute Essex-Lopresti syndrome is closed reduction percutaneous pinning (CRPP) of the distal radioulnar joint (DRUJ). This work aimed to verify whether it was possible to add a transfer of the brachioradialis tendon to the pinning. Case Description  The patient was a 39-year-old right-handed man, climbing instructor, who sustained the Mason II fracture and disjunction of the DRUJ. A transfer of the brachioradialis tendon severed from its muscle attach that was made through a bone tunnel passing through the radius and the neck of the ulna. The clinical and radiological result at the 6-month follow-up was satisfactory. Literature Review and Clinical Relevance  Our results in a single case showed that the brachioradialis tendon transfer was useful in acute Essex-Lopresti syndrome.

The ulnar interosseous tuberosity exists: a radiological and descriptive cadaveric study

PURPOSE

The anatomy of the ulna seems to have already been described exhaustively, particularly at its extremities, but very little in its middle third. We report the existence of an interosseous tuberosity on the interosseous border of the ulnar shaft that we have named the "tuberositas interossea ulnarii" (TIU).

METHODS

First, we analyzed all side view X-rays of the forearm in neutral rotation, as well as forearm CT scans carried out during a 1-year period in our hospital. On these radiographic examinations, we evaluated the presence or absence of the TIU, its length, the thickness of the interosseous cortex at its level, above and below compared with anterior, posterior, and lateral bone cortices. In the second part of the study, we dissected cadaveric forearms to determine which ligaments and muscles were attached to it.

RESULTS

A total of 91 standard forearm radiographs and 13 CT scans were analyzed. In all cases, the ulnar interosseous tuberosity was present. The mean tuberosity length was 107.5 mm (± 18.2), without any significant gender influence. It corresponded to a thickening (6.9 mm then 4.6 mm above and 3.9 mm below; p < 0.0001) of the ulnar interosseous cortex. Then, ten anatomic subjects (six females, four males) were dissected. We observed that this tuberosity served as an attachment for the central band of the interosseous membrane, for the deep flexor and extensor muscles for the long fingers, and for the abductor pollicis longus muscle's inner attachment.

CONCLUSION

Tuberositas interossea ulnarii exists besides the tuberositas interossea radii, corresponds to thickening of the cortex and may play a role in the stability of the forearm and the function of the long fingers.

Contribution of a distal radioulnar joint stabilizer on forearm stability: A modeling study

Instability of the forearm is a complex problem that leads to pain and limited motions. Up to this time, no universal consensus has yet been reached as regards the optimal treatment for forearm instability. In some cases, conservative treatments are recommended for forearm instability injuries. However, quantitative studies on the conservative treatment of forearm instability are lacking. The present study developed a finite element model of the forearm to investigate the contribution of the distal radioulnar joint stabilizer on forearm stability. The stabilizer was designed to provide stability between the radius and ulna. The forearm model with and without the stabilizer was tested using the pure transverse separation and radial pull test for the different ligament sectioned models. The percentage contribution of the stabilizer and ligament structures resisting the load on the forearm was estimated. For the transverse stability of the forearm, the central band resisted approximately 50% of the total transverse load. In the longitudinal instability, the interosseous membrane resisted approximately 70% of the axial load. With the stabilizer, models showed that the stabilizer provided the transverse stability and resisted almost 1/4 of the total transverse load in the ligament sectioned models. The stabilizer provided transverse stability and reduced the loading on the ligaments. We suggested that a stabilizer can be applied in the conservative management of patients who do not have the gross longitudinal instability with the interosseous membrane and the triangular fibrocartilage complex disruption.

Use of Gracile and semi-tendinosus tendons (GRAST) for the reconstruction of irreparable rotator cuff tears

Background

Irreparable rotator cuff tears are common and difficult to treat. Techniques for “filling the loss of substance” require fixation to the rotator cuff stump (tendon augmentation) or to the glenoid (superior capsular reconstruction), which are complicated by the narrow working zone of the subacromial space. The main objective of this study was to determine whether a braided graft of gracilis (GR) and semitendinosus (ST) could fill a loss of tendon substance from an irreparable rupture of the supra- and infraspinatus, by fixing the graft to the greater tuberosity and the spine of the scapula.

Methods

This was a cadaveric study with the use of ten specimens. The GRA and ST tendons were harvested, braided and reinforced with suture. An experimental tear of the supraspinatus (SS) and upper infraspinatus (IS) retracted at the glenoid was made. The GRAST transplant was positioned over the tear. The transplant was attached to the greater tuberosity by two anchors and then attached to the medial third of the scapular spine by trans-osseous stitching. The percentage of filling obtained was then measured and passive mobility of the shoulder was assessed. We proceeded to the same technique under arthroscopy for a 73 years old patient whom we treated for a painful shoulder with irreparable cuff tear. We inserted a GRAST graft using arthroscopy.

Results

The Braided-GRAST allowed a 100% filling of the loss of tendon substance. Mobility was complete in all cases.

Conclusion

This technique simplifies the medial fixation and restores the musculo-tendinous chain where current grafting techniques only fill a tendinous defect. The transplant could have a subacromial “spacer” effect and lower the humeral head. The donor site morbidity and the fate of the transplant in-vivo are two limits to be discussed. This anatomical study paves the way for clinical experimentation.

Structural topography of the interosseous membrane of the human forearm

The aim of this study was to evaluate the morphology of the six different parts of the interosseous membrane (IOM) in 11 human cadaver forearms, including the distal oblique bundle (DOB), the distal accessory band (DAB), the central band (CB), the proximal accessory band (PAB), the dorsal oblique accessory cord (DOAC), and the proximal oblique cord (POC). Hematoxylin-eosin and Elastica van Gieson stained slices were used to investigate the tissue morphology. The DOB and DOAC were absent in one IOM and the POB in two IOMs, respectively. The CB and DAB were longer than all other structures except for each other. The DOAC was longer than the DOB. The DAB, CB, and PAB, were broader than the DOB, DOAC, and POC. No significant differences were observed regarding structure thickness. All structures were found to consist of densely packed parallel collagen fiber arrangement. The DOB and POC had a higher amount of elastic fibers in the fascicular collagen tissue than the other structures. Elastic fibers were more often equally distributed throughout the structures than condensed epifascicular or at the insertion into bone. The tight parallel collagen composition within the different structures reflects the central stabilizing role of the IOM in the forearm. The higher amount of elastic fibers within the DOB and POC can be attributed to their location close to the distal and proximal radioulnar joints, respectively. Here elastic fibers allow adaption to forearm rotation, whereas the structures of the central part of IOM have less elasticity reflecting the predominant stabilizing function.

Immunofluorescence analysis of sensory nerve endings in the interosseous membrane of the forearm

The human interosseous membrane (IOM) is a fundamental stabilizer during forearm rotation. To investigate the dynamic aspects of forearm stability, we analyzed sensory nerve endings in the IOM. The distal oblique bundle (DOB), the distal accessory band (DAB), the central band (CB), the proximal accessory band (PAB), the dorsal oblique accessory cord (DOAC) and the proximal oblique cord (POC) were dissected from 11 human cadaver forearms. Sensory nerve endings were analyzed at two levels per specimen as total cell amount/mm² after immunofluorescence staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, S-100 protein and 4',6-diamidino-2-phenylindole on an Apotome microscope, according to Freeman and Wyke's classification. Sensory nerve endings were significantly more commonly found to be equally distributed throughout the structures, rather than being epifascicular, interstitial, or close to the insertion into bone (P ≤ 0.001, respectively). Free nerve endings were the predominant mechanoreceptor in all six structures, with highest density in the DOB, followed by the POC (P ≤ 0.0001, respectively). The DOB had the highest density of Pacini corpuscles. The DOAC and CB had the lowest amounts of sensory innervation. The high density of sensory corpuscles in the DOB, PAB and POC indicate that proprioceptive control of the compressive and directional muscular forces acting on the distal and proximal radioulnar joints is monitored by the DOB, PAB and POC, respectively, due to their closed proximity to both joints, whereas the central parts of the IOM act as structures of passive restraint.

Interosseous Membrane Reconstruction Utilizing Flexor Digitorum Superficialis Autograft

Interosseous membrane (IOM) deficiency results in longitudinal radioulnar instability, and may result in proximal radial migration, increased radiocapitellar contact, limitations in forearm rotation, ulnocarpal instability, and ulna-sided pain. A number of reconstruction methods have been posited-however, few have been implemented in vivo. We describe a 2-bundle method of IOM reconstruction, utilizing flexor digitorum superficialis autograft. This technique has the benefits of utilizing a locally available and robust autograft with minimal donor-site morbidity, obviating the concerns associated with synthetic grafts or bone-patella tendon-bone constructs. It also replicates the nonisometric nature of the native IOM. We also present long-term results of a patient who underwent IOM reconstruction utilizing this method, following a cadaveric feasibility study.

Chronic Essex-Lopresti injury: a systematic review of current treatment options

INTRODUCTION

Essex-Lopresti lesion (ELL) is a severe injury. Most of ELL is recognized in chronic phase representing a therapeutic challenge for orthopaedic surgeons. The aim of this systematic review is to highlight and criticize current concepts in the surgical treatment.

MATERIALS AND METHODS

The search was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline. A comprehensive research of Pubmed database was made using the following Mesh term: ((Essex-Lopresti injury) OR (Essex Lopresti) OR (distal radio ulnar dissociation) OR (distal radio ulnar dislocation) OR (longitudinal forearm instability)). Quality assessment of each article was performed according to Coleman score by two authors.

RESULTS

Eight full articles were included to the systematic review. Surgical treatment was differentiated in five categories according to the most common procedure reported in clinical series. The mean Coleman Score was 51.13 ± 9.76.

DISCUSSION

Case series reported in the literature include a limited number of patients with chronic ELL. Currently, salvage procedure devoted to treat a wrong diagnosis and an incorrect treatment is used. Radial head replacement together with ulnar shortening osteotomy and interosseous membrane reconstruction are the most common treatments of choice, but at present, there is not yet a shared scheme of management for patients with chronic ELL.

CONCLUSIONS

According to current literature, a case-by-case treatment must always be considered. Further investigations, with higher level of evidence, quality of study design, and number of patients, are needed to better assess clinical results and complication of each technique.

LEVEL OF EVIDENCE

IV.

Essex-Lopresti injuries: an update

Reconstruction of the central band of the interosseous membrane is an emerging procedure implemented in the treatment of longitudinal radioulnar dissociation (LRUD), usually in its chronic setting, after Essex-Lopresti injuries of the forearm.

There are no sufficient clinical data to support reconstruction of the central band of the interosseous membrane in acute LRUD injuries.

Clinical and cadaveric studies comparing autografts (palmaris longus, flexor carpi radialis and bone-patellar-bone), allografts (Achilles tendon) and synthetic ligaments have not shown superiority of one technique versus another; however, they have shown special concerns with respect to the use of synthetic grafts.

Latrogenic fracture, decrease of rotational range of movement, iatrogenic nerve injury (superficial radial and median nerve), donor site morbidity with autografts and recurrent instability are the complications reported in literature after interosseous membrane reconstruction.

Cite this article: EFORT Open Rev 2019;4:143-150. DOI: 10.1302/2058-5241.4.180072

Diagnosis and treatment of acute Essex-Lopresti injury: focus on terminology and review of literature

Background

Acute Essex-Lopresti injury is a rare and disabling condition of longitudinal instability of the forearm. When early diagnosed, patients report better outcomes with higher functional recovery. Aim of this study is to focus on the different lesion patterns causing forearm instability, reviewing literature and the cases treated by the Authors and to propose a new terminology for their identification.

Methods

Five patients affected by acute Essex-Lopresti injury have been enrolled for this study. ELI was caused in two patients by bike fall, two cases by road traffic accident and one patient by fall while walking. A literature search was performed using Ovid Medline, Ovid Embase, Scopus and Cochrane Library and the Medical Subject Headings vocabulary. The search was limited to English language literature. 42 articles were evaluated, and finally four papers were considered for the review.

Results

All patients were operated in acute setting with radial head replacement and different combinations of interosseous membrane reconstruction and distal radio-ulnar joint stabilization. Patients were followed for a mean of 15 months: a consistent improvement of clinical results were observed, reporting a mean MEPS of 92 and a mean MMWS of 90.8. One case complained persistent wrist pain associated to DRUJ discrepancy of 3 mm and underwent ulnar shortening osteotomy nine months after surgery, with good results.

Discussion

The clinical studies present in literature reported similar results, highlighting as patients properly diagnosed and treated in acute setting report better results than patients operated after four weeks. In this study, the definitions of “Acute Engaged” and “Undetected at Imminent Evolution” Essex-Lopresti injury are proposed, in order to underline the necessity to carefully investigate the anatomical and radiological features in order to perform an early and proper surgical treatment.

Conclusions

Following the observations, the definitions of “Acute Engaged” and “Undetected at Imminent Evolution” injuries are proposed to distinguish between evident cases and more insidious settings, with necessity of carefully investigate the anatomical and radiological features in order to address patients to an early and proper surgical treatment.

Late Reconstruction of the Interosseous Membrane with Bone-Patellar Tendon-Bone Graft for Chronic Essex-Lopresti Injuries: Outcomes with a Mean Follow-up of Over 10 Years

BACKGROUND

The purpose of this study was to report our long-term outcomes following reconstruction of the forearm interosseous membrane (IOM) with bone-patellar tendon-bone (BPTB) graft for treatment of chronic Essex-Lopresti injuries.

METHODS

We identified 33 patients who underwent IOM reconstruction with BPTB graft for chronic Essex-Lopresti injuries over a 20-year treatment interval. Twenty male and 13 female patients, with a mean age of 42.1 years (range, 19 to 73 years) and a minimum follow-up interval of 5 years, were included. Preinjury clinical examination and radiographic measurements were obtained from records for comparison with prospectively collected data. Additional functional outcome data collected postoperatively included QuickDASH (an abbreviated version of the Disabilities of the Arm, Shoulder and Hand [DASH]), modified Mayo wrist (MMW), and Broberg-Morrey elbow function scores.

RESULTS

IOM reconstruction was performed at a mean interval (and standard deviation) of 44.9 ± 60.0 months (range, 6.4 to 208 months) from the time of the initial injury. At a mean follow-up of 10.9 ± 4.4 years (range, 5.5 to 24.2 years), significant improvements were observed in mean elbow flexion-extension arc (+13° [95% confidence interval (CI), 4° to 22°]; p = 0.005), wrist flexion-extension arc (+19° [95% CI, 4° to 34°]; p = 0.016), forearm pronation-supination (+23° [95% CI, 8° to 39°]; p = 0.004), and grip strength (+25% of that of the contralateral side [95% CI, 18% to 32% of contralateral side]; p < 0.001). Improvements in ulnar variance were sustained over the long term from +3.9 mm (95% CI, 3.2 to 4.6 mm) preoperatively to -1.6 mm (95% CI, -2.3 to -0.9 mm) immediately postoperatively and -1.1 mm (95% CI, -1.8 to -0.4 mm) at the time of the final follow-up (p < 0.001). The mean QuickDASH, MMW, and Broberg-Morrey scores were 29.8 (range, 5 to 61), 82.7 (range, 60 to 100), and 91.6 (range, 64 to 100), respectively.

CONCLUSIONS

IOM reconstruction with a BPTB graft is an effective treatment option for chronic Essex-Lopresti injuries, with satisfactory clinical and functional outcomes over the long term.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Role of the Interosseous Membrane in Preventing Distal Radioulnar Gapping

Background Damage to the interosseous membrane (IOM) can alter load transmission between the radius and ulna and decrease their axial stability. Less is known about the effect of IOM sectioning on the transverse stability between the radius and ulna. Purpose The purpose of this study was to quantify the radioulnar gapping at the distal radioulnar joint (DRUJ) during forearm rotation when the IOM was experimentally sectioned while maintaining the integrity of the distal radioulnar ligaments. Methods In 12 fresh-frozen cadaver forearms tested in a combined wrist-forearm simulator, the increase in gap between the radius and ulna, at the level of the DRUJ, was determined during cyclic forearm rotation following IOM sectioning. Results IOM sectioning caused a significant increase in dorsal gapping at the DRUJ by 2.1 mm in supination and 0.6 mm in pronation. It also caused an increase in palmar gapping by 1.3 mm in supination and 0.5 mm in pronation. Conclusion This experiment has shown that the IOM has an important role in stabilizing the DRUJ, especially in supination, and that IOM sectioning caused greater loads on the palmar and dorsal radioulnar ligaments. Since DRUJ instability is primarily treated by fixing the laxity at the dorsal radioulnar ligament (DRUL) and palmar radioulnar ligament (PRUL), untreated IOM damage could permit additional injury and instability to the radioulnar ligaments or their reconstruction. Clinical Relevance Reconstruction of a torn IOM should be considered in the presence of persistent DRUJ instability following DRUJ reconstruction.

Wrist denervation of the posterior interosseous nerve through a volar approach: a new technique with anatomical considerations

PURPOSE

Full or selective wrist denervation is an effective treatment for chronic wrist pain. In this cadaveric study, a volar approach for prophylactic denervation of the posterior interosseous nerve (PIN) and the anterior interosseous nerve (AIN) was assessed, which can simultaneously be performed during volar approaches for distal radius fracture fixation or in combination with metalwork removal.

MATERIALS AND METHODS

In total 40 adult upper limbs, embalmed using Thiel's method, were investigated. Group 1 included 20 limbs of which the distances between AIN and PIN to the ulnar margin of radius were measured at levels 6, 8 and 10 cm proximal to the styloid process and the distance radial styloid process to proximal border of pronator quadratus which might be useful as an intraoperative landmark. Subsequently further additional 20 adult limbs (group 2) were used. Transection of the PIN via this volar approach at the evaluated best level of step 1 was performed and evaluated by dissection via a dorsal approach.

RESULTS

In group 1, the PIN runs within the interosseous membrane, from the ulnar border of the radius, 6.4 mm (SD 2.66) at 6 cm, 8.4 mm (SD 2.28) at 8 cm and 3.75 mm (SD 5.46) at 10 cm proximal to the radial styloid. The AIN runs within the interosseous membrane, from the ulna edge of the radius, 7.5 mm (SD 2.4) at 6 cm, 7.3 mm (SD 1.95) at 8 cm and 2.35 mm (3.42) at 10 cm proximal to the radial styloid. AIN and PIN were in close proximity at the 8-cm level which equals a 1-cm distance proximal to the pronator quadratus border. Group 2 showed a successful transection of the PIN through a single volar surgical approach in additional 18 out of 20 adult upper limbs.

CONCLUSIONS

This study shows the local anatomy of the PIN, allowing denervation via a volar approach.

Interosseous membrane reconstruction with a suture-button construct for treatment of chronic forearm instability

BACKGROUND

The purpose of this study was to report outcomes of interosseous membrane (IOM) reconstruction with a suture-button construct for treatment of chronic longitudinal forearm instability.

METHODS

We performed a retrospective review with prospective follow-up of patients who underwent ulnar shortening osteotomy and IOM reconstruction with the Mini TightRope device from 2011 through 2014. Bivariate statistical analysis was used for comparison of preoperative and postoperative Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores, range of motion, grip strength, and ulnar variance. Complications and patient satisfaction were also recorded.

RESULTS

Ten patients (mean age, 45.3 years) satisfied inclusion criteria: 8 treated for post-traumatic sequelae of Essex-Lopresti-type injuries, 1 for forearm instability secondary to previous elbow surgery, and 1 for instability secondary to trauma and multiple elbow surgeries. Surgeries were performed an average of 28.6 months from initial injury. At mean follow-up of 34.6 months after surgery, significant improvement was observed in elbow flexion-extension arc (+23° vs. preoperatively; P = .007), wrist flexion-extension arc (+22°; P = .016), QuickDASH score (-48; P = .000), and ulnar variance (-3.3 mm; P = .006). Three patients required additional surgery: 1 revision ulnar shortening osteotomy for persistent impingement, 1 revision ulnar osteotomy and Mini TightRope removal for lost forearm supination, and 1 fixation of a radial shaft fracture after a fall.

CONCLUSION

IOM reconstruction using a suture-button construct is an effective treatment option for chronic forearm instability.

Management of the Essex-Lopresti Injury

Essex-Lopresti injuries (ELIs) are characterized by fracture of the radial head, disruption of the forearm interosseous membrane, and dislocation of the distal radioulnar joint. This injury pattern results in axial and longitudinal instability of the forearm. Initial radiographs may fail to reveal the full extent of the injury, and therefore diagnosis in the acute setting requires a high index of suspicion. Early recognition and treatment are preferred as failure to fully treat the problem may result in chronic wrist pain from ulnar abutment or chronic elbow pain from radiocapitellar arthrosis. In this article the presentation, relevant anatomy, and management options for ELIs are overviewed, and a summary of outcomes reported in the literature is provided. Additionally, the preferred surgical technique of the senior author is presented, which involves reconstruction of the interosseous membrane with a local pronator rerouting autograft.

Squared ligament of the elbow: anatomy and contribution to forearm stability

OBJECTIVE

The present study describes the macroscopic and microscopic features of the squared ligament of the elbow (SLE). In addition, the SLE biomechanical behavior and contribution to the forearm stability were also examined.

MATERIALS AND METHODS

Ten forearms from freshly frozen cadavers were used for this work. Each forearm was mounted in an experimental frame for quantification of longitudinal and transverse stability. Macroscopic features and biomechanical behavior were analyzed on dynamic videos obtained during forearm rotation. Then, the SLE was harvested from the 10 forearms for microscopic analysis on histological slices stained with hematoxylin-eosin-saffron.

RESULTS

Two main SLE configurations were identified. One in which the SLE had three distinct bundles (anterior, middle, posterior) and another in which it was homogeneous. The anterior part of the SLE had a mean length of 11.2 mm (±2.4 mm) and a mean width of 1.2 mm (±0.2 mm) while the posterior part had a mean length of 9.9 mm (±2.2 mm) and a mean width of 1 mm (±0.2 mm). Microscopic examination showed that the SLE is composed of a thin layer of arranged collagen fibers. During forearm rotation, the SLE progressively tightens upon pronation and supination by wrapping around the radial neck. Tightening of the SLE during forearm rotation provides transverse and longitudinal stability to the forearm, mainly in maximal pronation and supination.

CONCLUSION

The SLE is a true ligament and provides forearm stability when it is stretched in pronation and supination.

Anatomy and biomechanics of the forearm interosseous membrane

PURPOSE

To examine the anatomy and function of the forearm interosseous membrane by exploring the anatomical insertions of the central band (CB) on the radius and the ulna and by quantifying the length of the intact ligament and replacement grafts located at the original CB attachment sites and alternative locations.

METHODS

Eight fresh cadaver forearms were supinated and pronated and the wrist was extended and flexed while the motion between the distal radius and ulna were recorded. The length of the CB was computed for the intact CB as well for several alternative graft orientations and positions.

RESULTS

The maximum length of the CB did not significantly change among different wrist motions. However, with the wrist in a static neutral position, the CB length was significantly shorter in forearm supination than in neutral. During active forearm rotation when CB replacement grafts were positioned distal or proximal to the original CB site, yet still parallel to it, each had a similar trend to be longer in neutral than in supination. If a graft was more transversely oriented, the computed CB length would be 1.6 mm shorter in supination than in neutral.

CONCLUSIONS

These results support tensioning a CB graft with the forearm in supination if the goal is to maximize graft tension and to maintain the native 22° angle for a CB graft between the radius and ulna. The results also suggest that the CB graft can probably be located slightly distal or slightly proximal to its original attachment sites.

CLINICAL RELEVANCE

Reconstruction of the interosseous membrane has been hampered by a lack of understanding of its length changes with forearm or wrist motion. These results provide a starting point in helping clinicians understand how to more precisely reconstruct this ligament in an anatomical manner.

Management of complications of forearm fractures

Forearm fractures may be complicated by the disruption of the distal radioulnar, proximal radioulnar, or radiocapitellar joints. The key principles in treating this unique subset of fractures include early recognition and management of the injury and restoration and maintenance of the anatomic alignment. This articles addresses radial diaphyseal fractures with distal radioulnar joint disruption, proximal ulnar fractures with radiocapitellar disruption, and disruption of the forearm longitudinal axis and how to properly recognize and manage these forearm fracture-dislocations.

Sequence of the Essex-Lopresti lesion--a high-speed video documentation and kinematic analysis

BACKGROUND AND PURPOSE

The pathomechanics of the Essex-Lopresti lesion are not fully understood. We used human cadavers and documented the genesis of the injury with high-speed cameras.

METHODS

4 formalin-fixed cadaveric specimens of human upper extremities were tested in a prototype, custom-made, drop-weight test bench. An axial high-energy impulse was applied and the development of the lesion was documented with 3 high-speed cameras.

RESULTS

The high-speed images showed a transversal movement of the radius and ulna, which moved away from each other in the transversal plane during the impact. This resulted into a transversal rupture of the interosseous membrane, starting in its central portion, and only then did the radius migrate proximally and fracture. The lesion proceeded to the dislocation of the distal radio-ulnar joint and then to a full-blown Essex-Lopresti lesion.

INTERPRETATION

Our findings indicate that fracture of the radial head may be preceded by at least partial lesions of the interosseous membrane in the course of high-energy axial trauma.

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.

Comparative morphometry of the antebrachial and crural interosseous membranes: preliminary study for the use of the crural interosseous membrane in the surgical repair of the antebrachial interosseous membrane tears

INTRODUCTION

Traumatic tears of the antebrachial interosseous membrane (AIOM) on its whole length are difficult to treat, particularly in the Essex-Lopresti syndrome. The number of ligamentoplasty techniques described in the literature witnesses the difficulty of its reconstruction and the absence of reliable and satisfying procedure. The aim of this study was to explore a new way of treatment, which consists in replacing the AIOM by the crural interosseous membrane (CIOM), harvested from the same patient.

MATERIALS AND METHODS

A morphometric study of the AIOM and CIOM has been conducted on both sides of 15 formalin preserved corpses (i.e. 30 AIOM and 30 CIOM). Studied data were: length of forearms and legs, length and width (at different locations) of the membranes, in situ and after harvesting, and orientation of their fibers. The thickness of membrane was also measured but only after harvesting.

RESULTS

Concerning the AIOM, the mean length was 13.3 cm in situ and 12.8 cm after harvesting. Its width was maximal at the union of middle and distal thirds with an average value of 1.7 cm in situ and 1.45 cm after harvesting. Mean thickness was 1 mm. Anterior fibers were oblique distally and medially (20.5° ± 0.95°), and posterior fibers were oblique distally and laterally (40° ± 3.4°). Concerning the CIOM, the mean length was 24.75 cm in situ and 23.9 cm after harvesting. Its width was maximal at the union of proximal and middle thirds with an average value of 2.3 cm in situ and 1.85 cm after harvesting. Mean thickness was 0.5 mm. Obliquity of its fibers was reverse of that of the AIOM: the anterior fibers were quite oblique distally and laterally (13° ± 2.6°), and the posterior fibers oblique were oblique distally and medially (24.2° ± 2.48°).

DISCUSSION

From these results, one may conclude that the largest length and width of the CIOM allow its use as substitute for the injured AIOM. The orientation of its fibers should necessitate either its reversal while using the same side or the use of the CIOM of the opposite side; its relative sharpness could signify that its biomechanical properties could be worse. A biomechanical study is necessary to evaluate how this new way of replacing the AIOM could resist to the strains imposed on the forearm.

The sequelae of a missed Essex-Lopresti lesion

Radial head fractures are the most common type of elbow fracture in adults. Unrecognised disruption of the intraosseous membrane at the time of injury can lead to severe wrist pain from proximal radial migration especially if the radial head is excised. In this case, despite anatomical reduction and internal fixation of the radial head fracture, longitudinal forearm instability developed after delayed radial head resection was performed 7 months post-injury. A Suave-Kapandji procedure was performed due to ongoing wrist pain. Because of the previous radial head resection, this led to a floating forearm that could only be solved by creating a one-bone forearm, sacrificing all forearm rotation to achieve a stable lever arm between the elbow and wrist joint.

Structural properties of 6 forearm ligaments

PURPOSE

To first determine the structural properties of 6 forearm ligaments and then to create linear and nonlinear analytical models of each ligament from these properties.

METHODS

We nondestructively tested the annular ligament, dorsal and palmar radioulnar ligaments, and the distal, central, and proximal bands of the interosseous ligament from 7 fresh cadaver forearms in a servohydraulic testing apparatus. We performed testing with the bone-ligament-bone constructs positioned corresponding to neutral forearm rotation as well as in 45° of supination and 45° of pronation. Based on a mechanical creep test of each ligament, we computed a linear and nonlinear ligament stiffness value for each ligament. We then compared these computed analytical responses to loading with loading data when each ligament was tested at 1.0 and 0.05 mm/s. We analyzed differences among ligaments and forearm positions using 1-way and 2-way analyses of variance.

RESULTS

The stiffnesses for the distal band and the dorsal radioulnar ligament were statistically less when the constructs were positioned in supination compared with neutral forearm rotation. At all forearm positions, the linear stiffness of the central band was greater than that for the distal band of the interosseous ligament, the proximal band of the interosseous ligament, and the dorsal radioulnar and palmar radioulnar ligaments. In neutral forearm rotation, the linear stiffness of the central band was statistically greater than the annular ligament. The experimental loading behavior of each ligament was better modeled by a nonlinear stiffness than a linear one.

CONCLUSIONS

The central band of the interosseous membrane is the stiffest stabilizing structure of the forearm. Any structure used to replace the central band or other forearm ligaments should demonstrate a nonlinear response to loading.

CLINICAL RELEVANCE

In considering a reconstruction for the forearm, the graft used should have a nonlinear response to loading and be one that is similar to the normal, original ligament.

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.

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.

[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.

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".