Radiographic and special studies: recent advances in imaging of the elbow

Does malpositioning of the arm influence radiographic range of motion measurement?

PURPOSE

Radiographic range of motion measurement of the elbow has been shown to be both precise and reliable. For this method to be used routinely in research studies, it is important to describe its limits regarding: (1) rotation of the arm from the perfect lateral position and (2) the length of humerus and ulna visible on the radiograph.

MATERIAL AND METHODS

A 3D bone reconstruction was performed from an upper limb CT scan. Planar radiographs were simulated for rotations of the elbow within a range of ±30o from the perfect lateral position. The field of view was modified, ranging from five visible centimeters of diaphysis on the radiograph to full visibility of the upper limb.

RESULTS

The disparity was less than 2.5° (mean=0.68°, SD=0.43°) when the flexed arm was rotated between -30.0° (external rotation, ER) and + 18.0° (internal rotation, IR). When considering the extended arm, measured angles differed by less than 2.5° (mean=0.79°, SD=0.57°) within a range of -15.0° (ER) to +30.0° (IR). When a minimum of 12 cm of humerus and ulna, from the capitellum, were visible on the radiograph measured angles varied very slightly (mean disparity of 0.71°, SD= 0.71°). Finally a qualitative description of the appearance of the radiographs was included to help surgeons estimate acceptable degrees of rotation.

CONCLUSION

Range of motion (ROM) measurement shows consistent results, despite 15 to 30 degrees of internal or external rotation. The middle third of the humeral and ulnar diaphyses should be visible on the radiographs to ensure the validity of measurement. Radiographic ROM measurement is still recommended over the goniometer for research purposes because of its high reliability and precision. Moreover, malpositioning of the elbow should not jeopardize results since it will most likely be an angle measurement variation of less than 2.5°.

New mechanism of the posterior elbow dislocation

PURPOSE

To suggest a new model on the most common kind of posterior elbow dislocation using MRI findings on acute elbow injuries.

METHODS

Fifteen patients with simple elbow dislocation (Group A) and 19 patients sustaining pure ligament injuries (Group B) were enrolled in this study. Using MRI scans, bony contusion at radial head and posterior capitellum (lateral bone contusion) and medial aspect of the ulnohumeral joint (medial bone contusion) were investigated with the injury patterns of the collateral ligament and overlying muscles. In Group A, the injury patterns of the ulnar and lateral ulnar collateral ligaments were classified into distraction or stripping type; in Group B, into rupture or strain. Based on these findings, we speculated the injury mechanism of the elbow dislocation.

RESULTS

In Group A, posterolateral (PL) dislocation was found in 12 cases of distractive ulnar collateral ligament type and stripping lateral ulnar collateral ligament type, where lateral bone contusion was found in 11 cases. Posteromedial (PM) dislocation was observed in only two cases of distraction type of the LUCL, where medial bone contusion was seen in two cases. In PL dislocation of the elbow joint, we always found more severe damage of soft tissue at the medial side of the elbow joint compared to the lateral side. Lateral bone contusion was speculated to be caused by bony abutment under pathologic forearm external rotation (PFER) and medial bone contusion, by bony abutment under varus stress. In Group B, the ulnar collateral ligament was more commonly injured than the lateral ulnar collateral ligament, and lateral bone contusion accompanied most cases.

CONCLUSION

PL dislocation is thought to start from the medial side in contrary to PM dislocation beginning at the lateral side. If the disengagement of the coronoid process is not completed due to the insufficient valgus/varus distraction, a coronoid fracture will develop at the same time as the elbow dislocation during PFER.

Posteromedial elbow impingement: magnetic resonance imaging findings in overhead throwing athletes and results of arthroscopic treatment

PURPOSE

The purpose of this study was to define the magnetic resonance imaging (MRI) pattern and assess the results of arthroscopic treatment of posteromedial elbow impingement in overhead throwers.

METHODS

Over an 8-year period, 9 throwing athletes diagnosed with posteromedial elbow impingement were retrospectively identified. All patients had either a noncontrast or direct arthrogram-MRI study that was reviewed by a single, fellowship-trained musculoskeletal radiologist blinded to the clinical diagnosis. Arthroscopic treatment included debridement of posteromedial synovitis, loose body removal, and excision of the olecranon spur. All patients underwent a physical examination and completion of the Andrews-Carson scale at a mean of 68 months (range, 25 to 112 months).

RESULTS

All patients were male, with a mean age of 21.0 years (range, 17 to 34 years). The dominant arm was affected in all patients. The mean length of symptoms before surgery was 9 months (range, 5 to 24 months). At MRI, a reproducible pattern of pathology was noted. All patients had pathology at the articular surfaces of the posterior trochlea and the anterior, medial olecranon. The findings ranged from abnormal edema-like signal in the hyaline cartilage to cartilage defects and subjacent, subchondral bone marrow edema. Findings at surgery included posteromedial synovitis and olecranon spurring in all patients and loose bodies in 3 patients. On the basis of the Andrews-Carson scale, the subjective and objective outcome was considered excellent in 7 patients and good in 2.

CONCLUSIONS

Posteromedial elbow impingement is a source of disability in the overhead throwing athlete. Correlation of history and physical examination with imaging findings is essential to confirm the diagnosis. This study indicates that MRI identifies a reproducible pattern of pathology in throwing athletes with this disorder. These MRI findings correlate highly with arthroscopic evaluation. Arthroscopic debridement, olecranon spur excision, and loose body removal allow return to throwing sports and reliable subjective and objective results in carefully selected patients.

Office-based ultrasound in sports medicine practice

Increasing knowledge, interest, and visibility in the field of sports medicine has equipped clinicians in the field with a novel array of diagnostic and therapeutic options but has also provided a higher level of complexity in patient care. True understanding of the vast spectrum of radiographic technology available to the sports clinician has become more critical than ever. Advances particularly in the areas of magnetic resonance imaging, diagnostic office ultrasound, and 3-dimensional reconstruction computed tomography, as well as nuclear medicine, offer the clinician a myriad of diagnostic options in patient evaluation. As these advances accumulate, the challenge to optimize care, contain cost, and interpret the extensive data generated becomes even more difficult to manage. Improving technology, education, and application of office ultrasound offers an interesting new tool for the bedside evaluation in real time of dynamic motion and pathology of sports-related injuries. As studies continue to validate ultrasound's effectiveness in diagnosing injuries to the upper and lower extremities compared with more costly magnetic resonance imaging and more invasive exploratory surgery, its promise as a cost-effective diagnostic tool is growing. A particularly promising development in the care of sports injuries is the expansion of injection therapies, and in-office ultrasound provides assurance that prolotherapy, platelet-rich plasma, dry needling, corticosteroid, and viscosupplementation are delivered accurately and safely. Communication with patients continues to increase in complexity because a greater understanding of the presence of radiographic abnormalities irrelevant to the current complaint is gained. All the accumulated data must then be interpreted and communicated to the patient with a firm understanding of not only the patient history and physical examination but also the availability, indications, contraindications, sensitivity, specificity, and even the cost implications of the spectrum of diagnostic options.

Imaging in sports medicine: an overview

Increasing sports participation, and the inevitable sports injury, is a significant contributor to total healthcare expenditure in the United States. With sports-related injury ever increasing, and technology rapidly expanding in the areas of diagnosis and treatment of musculoskeletal trauma, a continual revisiting of the latest in technology is critical for the sports physician. Advances particularly in the areas of magnetic resonance imaging, diagnostic office ultrasound, and 3-dimensional reconstruction computed tomography, offer the clinician a myriad of diagnostic options in patient evaluation. Care must be exercised, however, as one pursues additional radiographic data in the patient care arena. The information must be interpreted with a firm foundation and understanding of not only the patient history and physical examination, but also the availability, indications, contraindications, sensitivity, specificity, and even the cost implications of the great spectrum of diagnostic options.

Reprint of imaging of the elbow: a review of imaging findings in acute and chronic traumatic disorders of the elbow

Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.

Imaging of the elbow: a review of imaging findings in acute and chronic traumatic disorders of the elbow

Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.

Magnetic resonance imaging of the elbow: update on current techniques and indications

The utility of magnetic resonance imaging of the elbow has noticeably improved over the past decade. Advances in equipment and refinement of pulse sequences has allowed for superior visualization of many pathologic processes involving the elbow joint and its surrounding structures. At this time, magnetic resonance imaging is most valuable in detecting occult fractures, osteochondritis dissecans, collateral ligament tears, nonossified intra-articular loose bodies, and soft tissue masses. It may also aid in the diagnosis of tendinous injuries, compression neuropathies, and synovial disorders. This article serves as an educational update for hand surgeons and illustrates the features of normal anatomy and specific disorders of the elbow.