In vivo three-dimensional motion analysis of chronic radial head dislocations

Chronic isolated radial head dislocation in adults: Technical note and literature review

Isolated traumatic radial head dislocation is exceedingly rare in adults, usually diagnosed on an emergency basis, and reduced by external manoeuvres. If the diagnosis is not made immediately, external reduction is no longer feasible. Various options have been described for treating these chronic forms, including therapeutic abstention, radial head resection and annular ligamentoplasty combined, if appropriate, with osteotomy of the ulna. In patients with incapacitating symptoms, proposing a surgical option makes sense. Here, we describe the technique developed by PM Grammont, which combines ligamentoplasty and an oblique flat osteotomy of the ulna. We used this technique in a 31-year-old male with isolated anterior dislocation of the radial head of 3 months' duration. One year after surgery, he had fully recovered range of motion in all planes. He returned to work 5 months after surgery. The promising clinical and radiological outcomes in our patient support the use of this technique in adults with chronic isolated radial head dislocation. LEVEL OF EVIDENCE: IV.

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

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

An automatic genetic algorithm framework for the optimization of three-dimensional surgical plans of forearm corrective osteotomies

Three-dimensional (3D) computer-assisted corrective osteotomy has become the state-of-the-art for surgical treatment of complex bone deformities. Despite available technologies, the automatic generation of clinically acceptable, ready-to-use preoperative planning solutions is currently not possible for such pathologies. Multiple contradicting and mutually dependent objectives have to be considered, as well as clinical and technical constraints, which generally require iterative manual adjustments. This leads to unnecessary surgeon efforts and unbearable clinical costs, hindering also the quality of patient treatment due to the reduced number of solutions that can be investigated in a clinically acceptable timeframe. In this paper, we propose an optimization framework for the generation of ready-to-use preoperative planning solutions in a fully automatic fashion. An automatic diagnostic assessment using patient-specific 3D models is performed for 3D malunion quantification and definition of the optimization parameters' range. Afterward, clinical objectives are translated into the optimization module, and controlled through tailored fitness functions based on a weighted and multi-staged optimization approach. The optimization is based on a genetic algorithm capable of solving multi-objective optimization problems with non-linear constraints. The framework outputs a complete preoperative planning solution including position and orientation of the osteotomy plane, transformation to achieve the bone reduction, and position and orientation of the fixation plate and screws. A qualitative validation was performed on 36 consecutive cases of radius osteotomy where solutions generated by the optimization algorithm (OA) were compared against the gold standard solutions generated by experienced surgeons (Gold Standard; GS). Solutions were blinded and presented to 6 readers (4 surgeons, 2 planning engineers), who voted OA solutions to be better in 55% of the time. The quantitative evaluation was based on different error measurements, showing average improvements with respect to the GS from 20% for the reduction alignment and up to 106% for the position of the fixation screws. Notably, our algorithm was able to generate feasible clinical solutions which were not possible to obtain with the current state-of-the-art method.

Effect of soft tissue injury and ulnar angulation on radial head instability in a Bado type I Monteggia fracture model

The effects of soft tissue damage and ulnar angulation deformity on radial head instability in Monteggia fractures are unclear. We tested the hypothesis that radial head instability correlates with the magnitude of ulnar angular deformity and the degree of proximal forearm soft tissue injury in Bado type I Monteggia fractures.We performed a biomechanical study in 6 fresh-frozen cadaveric upper extremities. Monteggia fractures were simulated by anterior ulnar angulation osteotomy and sequential sectioning of ligamentous structures. We measured radial head displacement during passive mobility testing in pronation, supination, and neutral rotation using an electromagnetic tracking device. Measurements at various ligament sectioning stages and ulnar angulation substages were statistically compared with those in the intact elbow.Radial head displacement increased with sequential ligament sectioning and increased proportionally with the degree of anterior ulnar angulation. Annular ligament sectioning resulted in a significant increase in displacement only in pronation (P < .05). When the anterior ulnar deformity was reproduced, the radial head displaced least in supination. The addition of proximal interosseous membrane sectioning significantly increased the radial head displacement in supination (P < .05), regardless of the degree of anterior ulnar angulation.Our Monteggia fracture model showed that radial head instability is influenced by the degree of soft tissue damage and ulnar angulation. Annular ligament injury combined with a minimal (5°) ulnar deformity may cause elbow instability, especially in pronation. The proximal interosseous membrane contributes to radial head stability in supination, regardless of ulnar angulation, and proximal interosseous membrane injury led to significant radial head instability in supination.

Analysis of forearm rotational motion using biplane fluoroscopic intensity-based 2D-3D matching

Measuring three-dimensional (3D) forearm rotational motion is difficult. We aimed to develop and validate a new method for analyzing 3D forearm rotational motion. We proposed biplane fluoroscopic intensity-based 2D-3D matching, which employs automatic registration processing using the evolutionary optimization strategy. Biplane fluoroscopy was conducted for forearm rotation at 12.5 frames per second along with computed tomography (CT) at one static position. An arm phantom was embedded with eight stainless steel spheres (diameter, 1.5 mm), and forearm rotational motion measurements using the proposed method were compared with those using radiostereometric analysis, which is considered the ground truth. As for the time resolution analysis, we measured radiohumeral joint motion in a patient with posterolateral rotatory instability and compared the 2D-3D matching method with the simulated multiple CT method, which uses CTs at multiple positions and interpolates between the positions. Rotation errors of the radius and ulna between these two methods were 0.31 ± 0.35° and 0.32 ± 0.33°, respectively, translation errors were 0.43 ± 0.35 mm and 0.29 ± 0.25 mm, respectively. Although the 2D-3D method could detect joint dislocation, the multiple CT method could not detect quick motion during joint dislocation. The proposed method enabled high temporal- and spatial-resolution motion analyses with low radiation exposure. Moreover, it enabled the detection of a sudden motion, such as joint dislocation, and may contribute to 3D motion analysis, including joint dislocation, which currently cannot be analyzed using conventional methods.

The relationship between the morphological axis and the kinematic axis of the proximal radius

PURPOSE

Surgical procedures for impaired forearm rotation such as for chronic radial head dislocation remain controversial. We hypothesized that the morphological axis of the proximal radius is important for stable forearm rotation, and we aimed to clarify the relationship between the morphological axis and the kinematic axis of the proximal radius using four-dimensional computed tomography (4DCT).

METHODS

Ten healthy volunteers were enrolled. Four-dimensional CT of the dominant forearm during supination and pronation was obtained. The rotation axis of forearm rotation was calculated from all frames during supination and pronation. The principle axis of inertia, which represents the most stable rotation axis of a rigid body, was calculated for the proximal radius by extending its surface data incrementally by 1% from the proximal end. The angle between the kinematic rotation axis and the morphological rotation axis of each length was calculated.

RESULTS

The rotation axis of the forearm was positioned on the radial head 0.0 mm radial and 0.4 mm posterior to the center of the radial head proximally and 2.0 mm radial and 1.2 mm volar to the fovea of the ulnar head distally. The principle axis at 15.9% of the length of the proximal radius coincided with the forearm rotation axis (kinematic axis). Individual differences were very small (SD 1.4%).

CONCLUSION

Forearm rotation was based on the axis at 16% of the length of the proximal radius. This portion should be aligned in cases of severe morphological deformity of the radial head that cause "rattling motion" of the radial head after reduction procedures.

Annular ligament reconstruction in chronic Monteggia fracture-dislocations in the adult population: indications and surgical technique

Chronic Monteggia fracture is defined as dislocation of the radial head that is still present 4 weeks after injury. The cause may reside in residual ulnar deformity after internal fixation, in failure of annular ligament healing, or both. This situation may lead to elbow pain, decreased motion, neurologic problems and valgus deformity. The aim of the present study is to investigate indications and surgical technique for annular ligament reconstruction (ALR) in chronic Monteggia fractures. Relevant articles on annular ligament anatomy and biomechanics, clinical-radiographic evaluation of chronic Monteggia lesions and surgical techniques for ALR were reviewed. A case of an ALR in chronic Monteggia injury using a modified Bell Tawse surgical technique with triceps tendon autograft is presented. Little data exist on chronic Monteggia injury in the adult population. The annular ligament has a critical role in radial head stability. Nonetheless, bony alignment of the ulna is confirmed to be the most relevant feature to address in chronic Monteggia fractures. ALR has been advocated to address radial head instability both combined with ulna osteotomy and as a single procedure, with several surgical techniques described and controversial results reported. A modified Bell Tawse surgical technique resulted to be effective in the presented case. ALR seems to be indicated in chronic Monteggia fractures with normal bony alignment, without conclusive evidence on a preferable surgical technique.

Ligamentous reconstruction of the interosseous membrane of the forearm in the treatment of instability of the distal radioulnar joint

Objectives

To measure the quality of life and clinical outcomes of patients treated with interosseous membrane (IOM) ligament reconstruction of the forearm, using the brachioradialis (BR), and describe a new surgical technique for the treatment of joint instability of the distal radioulnar joint (DRUJ).

Methods

From January 2013 to September 2016, 24 patients with longitudinal injury of the distal radioulnar joint DRUJ were submitted to surgical treatment with a reconstruction procedure of the distal portion of the interosseous membrane or distal oblique band (DOB). The clinical-functional and radiographic parameters were analyzed and complications and time of return to work were described.

Results

The follow-up time was 20 months (6-36). The ROM averaged 167.92° (93.29% of the normal side). VAS was 2/10 (1-6). DASH was 5.63/100 (1-18). The time to return to work was 7.37 months (3-12). As to complications, one patient had an unstable DRUJ, and was submitted to a new reconstruction by the Brian-Adams technique months. Currently, he has evolved with improved function, and has returned to his professional activities. Three other patients developed problems around the transverse K-wire and were treated with its removal, all of whom are doing well.

Conclusion

The new approach presented in this study is safe and effective in the treatment of longitudinal instability of the DRUJ, since it has low rate of complications, as well as satisfactory radiographic, clinical, and functional results. It allows return to social and professional activities, and increases the quality of life of these patients.

Role of the interosseous membrane and annular ligament in stabilizing the proximal radial head

HYPOTHESIS

The purpose of our study was to determine the relative contributions of the annular ligament, proximal band, central band, and distal band of the interosseous membrane in preventing dislocation of the proximal radius.

METHODS

In part 1 of the study, 8 forearms were loaded transversely with the forearm intact, and the central band, proximal band, and annular ligament were sequentially sectioned to determine the percentage contribution of each structure in preventing transverse radial displacement. In part 2, 12 forearms were cyclically supinated and pronated while optical sensors measured radial and ulnar motion. Transverse radial head motion was computed as the distal band, central band, and proximal band (and annular ligament) were sequentially sectioned.

RESULTS

In part 1, there was no significant difference in the percentage contribution of each structure in preventing radial transverse displacement. In part 2, only after sectioning of the central band did significant radial head displacement occur. Greater displacements occurred in supination than in pronation. Dislocation of the proximal radius occurred in 2 arms after sectioning of all 3 structures.

DISCUSSION

Under pure transverse displacement, the central band, annular ligament, and proximal band equally contributed to stabilizing the radius. However, during forearm rotation, the central band contributed more to radial head stability than the annular ligament and proximal band. Our study contributes to our knowledge of forearm biomechanics, demonstrating the importance of the central band in providing proximal radial head stability. Forceful supination should be avoided after surgical procedures designed to stabilize the radial head.

Kinematic changes in elbow osteoarthritis: in vivo and 3-dimensional analysis using computed tomographic data

PURPOSE

To investigate in vivo 3-dimensional kinematics in elbow osteoarthritis. We hypothesized that normal kinematics is preserved in an osteoarthritic elbow with a normal radiocapitellar joint (OAN). Conversely, we hypothesized that an osteoarthritic elbow with radiocapitellar degenerative changes (OAD) would show an abnormal kinematics pattern. Furthermore, the differences in osteophyte formation between groups may affect elbow kinematics.

METHODS

We examined 7 normal elbows, 7 OAN elbows, and 9 OAD elbows. We investigated 3-dimensional kinematics using computed tomography registration techniques. The osteophyte location was determined using 3-dimensional bone models generated from computed tomography data.

RESULTS

The kinematics is different in OAN and OAD elbows. In the OAN group, the ulna changed by 11° from a valgus to a varus position during elbow flexion and demonstrated a 4° change in the axis of elbow motion, similar to that in normal elbows. Osteophytes formed medially on the olecranon fossa. In the OAD group, the ulna changed by 4° varus during flexion from the 90° position, but only by 2° valgus during elbow extension from 90°. The change in the axis of elbow motion was 9°. Additional osteophytes formed on the anteromedial and lateral trochlea, lateral olecranon fossa, and medial olecranon of the ulnotrochlear joint, and on the radiocapitellar joint.

CONCLUSIONS

Normal kinematics was preserved in the OAN group. The OAD group demonstrated marked changes in the direction of elbow motion in the extension range, and the valgus motion pattern during extension was decreased.

CLINICAL RELEVANCE

The results of the current study provide a good starting point for further research into the nature of arthritic progression in the elbow joint and the role of debridement arthroplasty.