گالفر کی کوہنی 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¶

Bony Anatomy¶

• The elbow is a trocho-ginglymoid joint consisting of medial and lateral articulations that provide bony stability [3].
• The medial articulation involves the trochlea and the ulna within the greater sigmoid notch, forming the ulnohumeral hinged portion [3].
• The ulnohumeral joint exhibits highly congruent anatomy through almost 180° of articular contact, with the exception of a bare area on the greater sigmoid notch devoid of cartilage [3].
• The coronoid process possesses medial and lateral facets that buttress the trochlea anteriorly [3].
• The sublime tubercle is located just distal and medial to the coronoid and serves as the attachment site for the anterior bundle of the medial ulnar collateral ligament [3].
• The medial epicondyle serves as the attachment site for the origins of the flexor pronator mass and is larger and more posteriorly oriented than the lateral epicondyle [3].
• The lateral articulation involves the capitellum and radial head, forming the radiocapitellar joint [3].
• The radius is held in close approximation to the ulna at the proximal radioulnar joint by the annular ligament [3].
• The area of the ulna that articulates with the margin of the radial head at the proximal radioulnar joint is known as the lesser sigmoid notch [3].
• The radial head is a concave elliptical structure covered with articular cartilage along the radiocapitellar joint and approximately 270° of the articular margin [3].
• The radial head articulates with both the capitellum and the lesser sigmoid notch [3].
• The lateral epicondyle is the origin of the lateral extensor musculature [3].
• The origin of the lateral ulnar collateral ligamentous complex is located just distal to the lateral epicondyle at the geometric center of the radiocapitellar articulation [3].
• The distal humeral articulation is angled 30° from the longitudinal axis [3].
• The anterior humeral line should pass through the center of the axis of rotation [3].
• The axis of rotation is angulated 5° to 7° in the coronal plane relative to the epicondylar axis, with the medial side more distal than the lateral side [3].
• The angulation of the distal humeral articulation accounts for the change from a valgus carrying angle to a more varus position as the elbow is flexed [3].
• There is a high correlation between the size of the radius and capitellum on the left and right sides within the same individual [3].
• The olecranon provides a broad attachment site for the triceps [3].
• The ulna bends approximately 8° medially at 8 cm from the tip of the olecranon [3].
• The articulation to the tip of the coronoid is approximately 30° from the long axis of the ulna in the sagittal plane [3].

Ligaments & Stability¶

• Elbow stability is determined by primary and secondary stabilizers [1].
• The three primary stabilizers of the elbow are the ulnohumeral articulation, the medial ulnar collateral ligament, and the lateral ulnar collateral ligament complex [1].
• Secondary stabilizers include the radiocapitellar articulation, the common flexor tendon, the common extensor tendon, and the joint capsule [1].
• The medial ulnar collateral ligament is the primary valgus stabilizer of the elbow [4].
• The anterior bundle of the medial ulnar collateral ligament is the most important component for stability [4].
• The posterior bundle of the medial ulnar collateral ligament exhibits the greatest change in length and becomes taut at flexion beyond 120 degrees [4].
• The lateral ulnar collateral ligament acts as a posterolateral stabilizer [4].
• Osborne’s ligament stabilizes the ulnar nerve in the cubital tunnel [4].
• The ligament of Struthers is a variant anatomy arising from the supracondylar process to attach to the medial epicondyle and is a potential site of median nerve compression [4].
• Tensile forces are present at the medial elbow, while compressive forces are present at the lateral elbow [4].
• The joint capsule allows maximum distension at approximately 70 to 80 degrees of flexion [4].
• The anterior capsule attaches at a point approximately 6 mm distal to the tip of the coronoid [4].
• The coronoid tip is an intraarticular structure that is visualized during elbow arthroscopy [4].

Muscles & Tendons¶

• The brachialis is the strongest elbow flexor and attaches to the coronoid 11 mm distal to the tip [4].
• The biceps brachii inserts at the ulnar margin of the radial tuberosity, with the long head inserting proximally and the short head distally [4].
• The biceps brachii is a powerful supinator of the forearm [4].
• The triceps is the primary elbow extensor and inserts on the olecranon process [4].
• The mobile wad consists of the brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis [4].
• The flexor-pronator mass consists of the pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis [4].
• The common origin of the extensor muscles is attached to the lateral condylar fragment [6].
• The common origin of the extensor muscles can be separated from the lateral epicondyle with a thin flake of bone or divided just distal to the lateral epicondyle [6].

Biomechanics & Motion¶

• The normal elbow has a range of motion from 0° to 140° from extension to flexion [1].
• The normal elbow has a range of motion of 75° in pronation and 85° in supination [1].
• A functional arc for the elbow is 100° for flexion and extension [1].
• A functional arc for the elbow is 100° for forearm rotation [1].

Investigations¶

History and Physical Examination¶

• The physical examination of the elbow is directed by the history and the location of the patient's pain in the anterior, posterior, medial, or lateral aspect of the elbow [1].
• The normal elbow has a range of motion of 75° and 85° in pronation and supination, respectively [1].
• A functional arc for the elbow is 100° for flexion and extension and forearm rotation [1].
• Elbow stability is determined by primary stabilizers, which include the ulnohumeral articulation, the medial ulnar collateral ligament (MUCL), and the lateral ulnar collateral ligament (LUCL) complex [1].
• Secondary stabilizers of the elbow include the radiocapitellar articulation, the common flexor tendon, the common extensor tendon, and the joint capsule [1].
• The ulnar nerve is of utmost importance in the physical examination due to its anatomic proximity to the elbow [9].
• The posterior bundle of the medial collateral ligament (MCL) forms the floor of the cubital tunnel along the course of the ulnar nerve [9].
• Electromyography and nerve conduction velocity studies should be performed if there is any question about neurologic dysfunction [9].
• An assessment for ulnar nerve subluxation should be performed during the physical examination [9].
• Subluxation of the ulnar nerve is a relative contraindication for an arthroscopic procedure secondary to possible iatrogenic nerve injury [9].
• If the elbow has less than 90° to 100° of flexion, the posterior bundle of the medial collateral ligament (MCL) is contracted and must be released to restore flexion [9].
• Pain during the mid-arc of range of motion is more common with intrinsic disease and may not improve with contracture release alone [9].

Imaging¶

• Plain radiographs remain the hallmark and the best screening test for elbow evaluation [1].
• Standard radiographic views for the elbow include AP, lateral, and oblique views [9].
• Serial radiography is used as follow-up when heterotopic ossification is present [9].
• Primary bony landmarks identified on radiographs include the ulnohumeral joint, coronoid process, radial head, capitellum, radiocapitellar joint, olecranon tip, coronoid/olecranon fossae, and trochlear ridge [9].
• CT is helpful when assessing for malunion architecture and the location and pattern of osteophytes and/or loose bodies [9].
• Three-dimensional CT is used to check for heterotopic ossification [9].
• CT is not necessary when the stiffness is entirely soft-tissue related [9].
• CT is beneficial if any joint incongruity or abnormal bony anatomy is present [9].
• MRI can be used to evaluate ligaments and tendons, but it is rarely indicated for elbow stiffness [9].
• AP, lateral, oblique, and axillary views of the elbow may reveal posteromedial olecranon osteophytes and/or loose bodies in valgus extension overload syndrome [11].
• CT with two-dimensional reconstruction and three-dimensional surface rendering best visualizes the pathology of valgus extension overload syndrome [11].
• MRI may be most helpful in evaluating associated injuries including partial or complete tears of the medial collateral ligament (MCL) in valgus extension overload syndrome [11].
• Radiographic evaluations are essential when diagnosing an osteochondritis dissecans (OCD) lesion of the elbow [12].
• Important aspects of OCD lesions may be better seen with MRI [12].
• Standard AP and lateral radiographs should be obtained for the evaluation of elbow osteoarthritis [13].
• Radiographs for elbow osteoarthritis typically show osteophyte formation at the coronoid process, coronoid fossa, radial fossa, radial head, olecranon tip, and olecranon fossa [13].
• Joint spaces at the ulnohumeral joint are usually preserved in elbow osteoarthritis [13].
• Joint spaces at the radiocapitellar joint are mildly narrowed in elbow osteoarthritis [13].
• Loose bodies may be evident on radiographs, which typically underestimate the number present [13].
• CT may be useful for surgical planning of elbow osteoarthritis, allowing a detailed assessment of osteophytes and the presence of loose bodies [13].

References¶

[1] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Anatomy, Biomechanics, Physical Examination, and Imaging of the Elbow > Summary and Conclusions.

[3] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Anatomy, Biomechanics, Physical Examination, and Imaging of the Elbow > Anatomy > Bony Anatomy.

[4] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > TABLE 2.3 Shoulder Spaces.

[6] Campbell S Operative Orthopaedics 4 Volume Set. LATERAL APPROACHES.

[9] Aaos Comprehensive Orthopaedic Review 3. Elbow Stiffness* > IV. Evaluation.

[11] Aaos Comprehensive Orthopaedic Review 3. Elbow Injuries in the Athlete* > III. Valgus Extension Overload Syndrome and Posterior Impingement.

[12] Orthopaedic Knowledge Update. Osteochondritis Dissecans of the Knee and Elbow* > Summary.

[13] Aaos Comprehensive Orthopaedic Review 3. Arthritis and Arthroplasty of the Elbow > I. Osteoarthritis.