ڈی کیورین کی رہائی

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Anatomy & Pathophysiology¶

First Extensor Compartment Anatomy¶

• A common septum is found between the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons in 80% of patients requiring surgical release for de Quervain tenosynovitis [2].
• The first dorsal compartment of the wrist contains the APL and EPB tendons [7].
• The fibrous and osseous components of the first extensor compartment of the wrist have been characterized in cadaveric studies [1].

Wrist Bony Anatomy¶

• The wrist includes the distal radioulnar, radiocarpal, and ulnocarpal joints, as well as the eight carpal bones and their proximal and distal articulations [3].
• The proximal row of carpal bones consists of the scaphoid, lunate, triquetrum, and pisiform [3].
• The distal row of carpal bones consists of the trapezium, trapezoid, capitate, and hamate [3].
• The distal radius has three articular components: the scaphoid fossa, the lunate fossa, and the sigmoid notch [7].
• The concave elliptical distal radius is oriented in the sagittal plane with an average of 11 degrees of volar tilt [7].
• In the frontal plane, the average radial inclination of the distal radius is 23 degrees [7].
• Radial length is measured from the tip of the radial styloid to the ulnar articular surface and averages 13 mm [7].
• The distal ulnar convexity articulates at the lesser sigmoid notch of the distal radius [3].
• There is about a 20-degree inclination of the distal ulna at its articulation with the radius [3].

Wrist Ligaments and Soft Tissue¶

• Extrinsic carpal ligaments connect the radius or the ulna to the carpus [8].
• In general, volar wrist ligaments are stronger than dorsal ligaments [8].
• The triangular fibrocartilage complex (TFCC) attaches to the ulnar margin of the lunate fossa of the radius and includes the ulnar collateral ligament, dorsal and volar radioulnar ligaments, articular disc, meniscal homologue, extensor carpi ulnaris sheath, and ulnolunate and ulnotriquetral ligaments [3].
• The space of Poirier is a relatively thin area on the palmar side of the carpus situated between the radiolunotriquetral ligament and the radioscapocapitate ligament, overlying the palmar surface of the lunate [3].
• The space of Poirier is a weak area vulnerable to instability where the distal carpal row separates from the lunate during a perilunate dislocation [8].
• The dorsal radiocarpal ligament has a trapezoidal shape and passes from the dorsal rim of the distal radius to the lunate and the triquetrum [8].
• The scapholunate interosseous ligament is C-shaped, consisting of dorsal, palmar, and interosseous portions, with the dorsal portion being the strongest and thickest [8].
• The lunotriquetral interosseous ligament is C-shaped, with the volar portion being the thickest and strongest [8].

Wrist Biomechanics and Kinematics¶

• The radius bears 80% of the axial load transmitted through the radiocarpal joint, while the ulna bears 20% in neutral ulnar variance [8].
• Approximately 62° of wrist extension occurs through the radiocarpal joint [8].
• Approximately 62% of wrist flexion occurs through the midcarpal joint [8].
• The midcarpal joint is mostly responsible for 20° of radial deviation and 40° of ulnar deviation [8].
• The midcarpal joint is responsible for the “dart thrower’s motion,” which involves moving from radial extension into ulnar flexion positioning of the wrist [8].
• During wrist flexion from neutral, the proximal row translates dorsally [8].
• During wrist extension from neutral, the proximal row translates palmarly [8].
• The extensor carpi ulnaris (ECU) ulnarly deviates the wrist when the forearm is in pronation and extends the wrist when the forearm is supinated [2].
• The ECU provides both static and dynamic support to the wrist [2].
• The volar ECU sheath is adjacent to the TFCC, and ECU injury may coexist with concomitant TFCC injury [2].

Pathophysiology and Associated Conditions¶

• Tenosynovitis of the ECU is a common cause of ulnar-sided wrist pain [2].
• Painful dorsal wrist swelling may be the presenting symptom in rheumatoid arthritis, and tenosynovial swelling may contribute to de Quervain disease [11].
• In rheumatoid arthritis, synovitis can spread and cause massive swelling in the shape of an hourglass, with the middle constricted by the extensor retinaculum [11].
• The human wrist is described as the most complex articular system in the human body, with each carpal bone capable of moving in different degrees or directions dependent on hand position, motion, and force generation [4].

Physical Examination¶

• Patients with ECU tenosynovitis present with tenderness over the ECU tendon [2].
• Patients with ECU tenosynovitis present with swelling [2].
• Patients with ECU tenosynovitis present with pain with resisted wrist extension [2].
• Patients with ECU tenosynovitis do not have instability [2].
• The ECU synergy test helps distinguish a TFCC injury from ECU tenosynovitis [2].
• In the ECU synergy test, the patient rests the elbow of the supinated forearm on a table with the digits extended [2].
• In the ECU synergy test, the examiner grasps the patient’s thumb and long finger and asks the patient to deviate the thumb radially against resistance [2].
• In the ECU synergy test, the examiner’s other hand gently palpates the ECU and flexor carpi ulnaris [2].
• The presence of pain during the ECU synergy test suggests pathology in the ECU rather than intra-articular pathology [2].

Imaging¶

• Ultrasonography can be used to distinguish tenosynovitis from ECU subsheath injury in patients whose examination is equivocal [2].
• MRI can be used to distinguish tenosynovitis from ECU subsheath injury in patients whose examination is equivocal [2].

Investigations¶

Magnetic Resonance Imaging¶

• MRI has been an important diagnostic tool for hand and wrist imaging since its first report in 1986 [9].
• The primary advantages of MRI compared with CT and radiography are improved tissue characterization, especially of soft tissues such as ligamentous structures and synovium, and the lack of ionizing radiation [9].
• MRI is the modality of choice for imaging radiographically occult fractures of the hand and wrist [9].
• Early MRI was limited by low magnetic field strength (0.15 T) and limited image options and processing [9].
• Modern MRI is generally performed at 1.5T or 3T with a wide variety of imaging options and powerful image processing [9].
• 3T MRI is much preferred for hand and wrist imaging, especially for imaging small fields of view [9].
• Dedicated extremity magnets have been marketed, but their image quality is poor compared with conventional MR imaging [9].
• 7T MRI has recently become approved for clinical use and has the potential to become a powerful tool for hand and wrist imaging as applications are developed [9].
• MRI with contrast enhancement is most commonly used to determine whether soft-tissue lesions are solid or cystic or to better visualize erosions and synovial burden in rheumatologic imaging [9].
• Dynamic contrast enhancement has been used with inconsistent results to assess for the presence of avascular necrosis in the lunate or scaphoid after injury [9].
• MR angiography of the hand and wrist can be helpful in situations such as the diagnosis of hypothenar hammer syndrome [9].
• MR arthrography can be performed for evaluation of triangular fibrocartilage and intercarpal ligament tears, but this is generally unnecessary with the increasing availability of high-field MRI [9].
• The use of MRI for hand and wrist imaging was first reported in 1986 [9].

Radiography and Computed Tomography¶

• Hybrid SPECT/CT has been used for the diagnosis of radiographically occult fractures of the wrist [5].
• Cone-beam CT has been used in the diagnosis of scaphoid fractures [5].
• CT and MRI have a diagnostic impact on wrist injuries in young adults [5].
• Distal radioulnar joint stress radiography has been used for detecting radioulnar ligament injury [5].
• Cine MRI has been used as a new approach to the diagnosis of scapholunate dissociation [5].
• Radiographic stress views have been compared for scapholunate dynamic instability in a cadaver model [5].
• Cone-beam computed tomography arthrography is an innovative modality for the evaluation of wrist ligament and cartilage injuries [5].
• Simple plain radiographic signs and measures have been evaluated for the accuracy of diagnosing acute scapholunate ligament injuries of the wrist [10].
• Radiographic clues have been used for determining carpal instability and treatment protocols for scaphoid fractures [10].

References¶

[1] Campbell S Operative Orthopaedics 4 Volume Set. ANATOMIC RECONSTRUCTION OF THE DISTAL RADIOULNAR LIGAMENTS > ANATOMY AND BIOMECHANICS.

[2] Aaos Comprehensive Orthopaedic Review 3. Tendinopathy of the Hand and Wrist* > VII. Extensor Carpi Ulnaris Tenosynovitis.

[3] Campbell S Operative Orthopaedics 4 Volume Set. NERVE INJURIES AT THE LEVEL OF THE HAND AND WRIST > ANATOMY.

[4] Green S Operative Hand Surgery. INTRODUCTION.

[5] Campbell S Operative Orthopaedics 4 Volume Set. ANATOMIC RECONSTRUCTION OF THE DISTAL RADIOULNAR LIGAMENTS > RADIOGRAPHIC TECHNIQUES.

[7] A Lange Medical Book Current Diagnosis Treatment In Orthopedics Fifth Edition. 2Musculoskeletal Trauma Surgery > FRACTURES AND DISLOCATIONS OF THE DISTAL AND MID-FOREARM.

[8] Aaos Comprehensive Orthopaedic Review 3. Carpal Instability* > II. Anatomy and Biomechanics (See Chapter 92).

[9] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Anatomy, Evaluation, Clinical Examination, and Imaging > Imaging: Advances in Imaging of the Hand and Upper Extremity > Magnetic Resonance Imaging.

[10] Campbell S Operative Orthopaedics 4 Volume Set. ANATOMIC RECONSTRUCTION OF THE DISTAL RADIOULNAR LIGAMENTS > DIAGNOSIS AND EVALUATION.

[11] Campbell S Operative Orthopaedics 4 Volume Set. THUMB CARPODNETACARPAL ARTHRODESIS WITH KIRSCHNER WIRE OR BLADE-PLATE FIXATION > SYNOVITIS OF THE WRIST.