ڈی آئی پی مشترکہ فیوژن

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 and Articular Anatomy¶

• The hand consists of 19 bones, 17 articulations, and 19 muscles situated entirely within the hand [2].
• Each finger ray is a polyarticular chain composed of a metacarpal and three phalanges [2].
• The distal interphalangeal (DIP) joint is the most distal articulation in the finger ray [2].
• The dorsal integument of the distal phalanx is characterized by the presence of the nail bed and its matrix [3].
• The MCP joint contributes 77% of the total arc of finger flexion [18].
• Studies indicate that 5 to 10 degrees of flexion and 30 to 35 degrees of extension are needed for most activities of daily living [18].

Soft Tissue Anatomy¶

• The terminal tendon inserts at the base of the distal phalanx to extend it [4].
• The two conjoined lateral bands to each finger unite at the distal third of the middle phalanx to form the terminal tendon [4].
• The dorsal covering of the interphalangeal articulations forms a unique cutaneous unit characterized by a considerable excess of skin when the digits are in extension [3].
• The fine tight skin of the dorsal aspect of the middle phalanx forms a distinct functional cutaneous unit [3].
• The skin covering each finger is 7 cm by 10 cm on both the palmar and dorsal aspects [6].
• The necessary skin to cover the thumb distal to the metacarpophalangeal joint is about 9 cm wide and 8 cm long [6].

Extensor Mechanism and Pathomechanics¶

• The deep head of each dorsal interosseous muscle extends the middle and distal phalanges [4].
• The superficial head of the dorsal interosseous muscle has no direct effect on the middle or distal phalanges [4].
• Boutonnière deformities primarily arise at the PIP joint when stretching of the extensor tendon over the joint induces hyperextension of the DIP and MCP joints [17].
• Acute boutonnière deformity results from central slip disruption and volar subluxation of the lateral bands, resulting in DIP hyperextension [15].
• In boutonnière deformity, attenuation of the central slip results in unopposed flexion at the PIP joint [16].
• With PIP joint flexion in boutonnière deformity, the lateral bands drift volar to the axis of rotation at the PIP joint [16].
• The lateral bands stay in the volar position owing to loss of dorsal support from the attenuated triangular ligament and contracture of the transverse retinacular ligament [16].
• Swan neck deformities can occur at the DIP, PIP, and MCP joints as a result of multiple etiologies [13].
• Synovitis can cause a flexion deformity at the DIP joint [13].
• A zigzag deformity propagates proximally because there is stretching of the terminal tendon [13].
• In type I swan neck deformity, the deformity can originate at the DIP joint with stretching or rupture of the terminal extensor tendon attachment, resulting in a mallet deformity [14].
• Imbalance of the extensor mechanism secondary to DIP joint flexion coupled with laxity of the PIP joint volar plate allows the PIP joint to assume a posture of hyperextension [14].

Functional Considerations¶

• DIP fusion of the digits is generally tolerated well with limited loss of function [18].
• PIP joint motion is much more important to preserve than DIP joint motion [18].
• Fingers with fused PIP joints are of little use for grip or grasp and frequently get in the way [18].
• The quadriga effect can occur when profundus excursion is impaired with arthrodesis [18].
• Even with a successful DIP fusion, the fine motor skills of a finger may be compromised [14].

Clinical Presentation¶

Physical Examination¶

• Inspection of the dorsal and palmar surfaces of the hand is the initial step in physical examination [19].
• Swelling and volar subluxation may be present at the metacarpophalangeal (MCP) joints in osteoarthritis [19].
• Flexion contracture or extension lag may be associated with MCP joint swelling and volar subluxation [19].
• Proximal interphalangeal (PIP) joints may display flexion contractures in osteoarthritis [19].
• The Bouchard node is a distinguishing characteristic of osteoarthritic PIP joints [19].
• The presence of Heberden nodes heralds inspection of the osteoarthritic distal interphalangeal (DIP) joint [19].
• Heberden nodes signify swelling and periarticular osteophyte formation at the DIP joint [19].
• Mucous cyst formation may occur in relation to an osteoarthritic DIP joint [19].
• Palpation of an acutely inflamed osteoarthritic DIP joint elicits tenderness [19].
• Palpation of an acutely inflamed osteoarthritic DIP joint elicits a sensation of fullness about the joint [19].
• Palpation of an acutely inflamed osteoarthritic DIP joint reveals loss of the normal bony contour of the joint [19].
• The examiner can detect tenderness and synovitis by applying small pressure while holding the joint between the dominant thumb and index finger [19].
• Range of motion of each joint may be limited due to a superimposed flexion contracture [19].
• Digital range of motion is often expressed in terms of total active range of motion, approximately 250 degrees [19].
• Normal DIP joint range of motion is 0 to 60 degrees [19].
• Tendon integrity may be compromised in the osteoarthritic hand [19].
• Chronic tenosynovitis of the flexor tendon uncommonly coexists with a zone 2 flexor digitorum superficialis (FDS) or flexor digitorum profundus (FDP) tendon rupture [19].
• Extensor tendons are more commonly involved in osteoarthritic hands [19].
• Ulnar subluxation of extensor tendons at the level of the MCP joints occurs secondary to failure of the sagittal bands [19].
• Ulnar drift and flexion positioning of the digits at the level of the MCP joints result from extensor tendon subluxation [19].
• In the acute phase, extensor tendon subluxation and ulnar drift/MCP flexion may be passively correctable [19].
• In the acute phase, extensor tendon subluxation and ulnar drift/MCP flexion are amenable to individual MCP extension splinting for 3 weeks [19].
• In the chronic situation, the only treatment option is surgical release of the tight sagittal bands [19].
• Surgical release of tight sagittal bands in chronic cases may be performed with or without intrinsic releases [19].
• Surgical release of tight sagittal bands in chronic cases may be performed with extensor tendon realignment [19].

Erosive or Inflammatory Osteoarthritis¶

• Erosive or inflammatory osteoarthritis is an uncommon variant of osteoarthritis first described in 1966 by Peter and coworkers [19].
• Erosive or inflammatory osteoarthritis is more common in women [19].
• Symptoms of erosive or inflammatory osteoarthritis appear abruptly [19].
• Erosive or inflammatory osteoarthritis involves the joints on the radial aspect of the hand [19].
• Erosive or inflammatory osteoarthritis spares the joints on the ulnar side [19].
• The DIP joint is the most commonly affected joint in erosive or inflammatory osteoarthritis [19].
• The PIP joint is the most commonly symptomatic joint in erosive or inflammatory osteoarthritis [19].
• In some patients, erosive osteoarthritis will seroconvert to rheumatoid arthritis at a later time [19].

Diagnostic Imaging¶

• Plain posteroanterior (PA), lateral, and oblique radiographic views can adequately image the osteoarthritic hand [19].
• Further detail can be obtained by directly imaging the individual digit [19].
• Direct imaging of the individual digit involves an attempt to center the radiograph beam over the joint in question [19].

Investigations¶

• Clinical evaluation of the injured or dysfunctional hand and wrist requires combining patient history with a careful physical examination to pinpoint or narrow the scope of possible pathologic processes [1].
• Diagnostic tests such as imaging and serum laboratory studies are useful in determining pathology but can be expensive, time consuming, and often nonspecific [1].
• A careful physical examination is essential to direct care and future testing if indicated [1].
• The skeleton of the hand and wrist consists of 27 bones, of which 19 are long bones [12].
• The skeleton is divided into five rays, each ray making up a polyarticulated chain comprising the metacarpals and phalanges [12].
• The base of each metacarpal articulates with the distal row of the carpus [12].
• The carpus articulates with the skeleton of the forearm through its proximal row [12].
• The radioulnocarpal articulation has two axes of movement to which is added a third—pronation and supination from the forearm [12].
• The wrist has three axes of movement, permitting the hand to be positioned in any spatial configuration and allowing it to be placed as needed for grasping [12].
• The radial ray or first ray is the shortest and is made up of only three bones—a metacarpal and two phalanges [12].
• The other four digital rays are formed by four skeletal segments—a metacarpal and three phalanges [12].
• The thumb metacarpal is the shortest, the index finger metacarpal is the longest, and the others decrease in length from the third to the fifth digits [12].
• The proximal and particularly the middle phalanges of the middle and ring fingers are longer than those of the index finger [12].
• The long finger, and usually the ring finger, are longer than the index finger [12].
• The epiphyseal plates are located at the proximal ends of the phalanges and the first metacarpal [12].
• The epiphyseal plates are located at the distal ends of the other metacarpals [12].

References¶

[1] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Anatomy, Evaluation, Clinical Examination, and Imaging > Evaluation and Clinical Examination: Current Concepts.

[2] Exam Of The Hand Wrist 2Ed. INTRODUCTION.

[3] Exam Of The Hand Wrist 2Ed. Functional cutaneous units.

[4] Green S Operative Hand Surgery. Interosseous and Hypothenar Muscles.

[6] Exam Of The Hand Wrist 2Ed. Planning skin cover of the hand and forearm.

[12] Exam Of The Hand Wrist 2Ed. 1.1 SKELETON OF THE HAND > The osseous skeleton.

[13] Green S Operative Hand Surgery. Swan Neck Deformities.

[14] Green S Operative Hand Surgery. Swan Neck Deformities > Postoperative Care.

[15] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > TENDON INJURIES AND OVERUSE SYNDROMES > Zone III injury (boutonnière).

[16] Miller S Review Of Orthopaedics. TENDON INJURIES AND OVERUSE SYNDROMES > Zone III injury (boutonnière).

[17] Green S Operative Hand Surgery. Boutonnière Deformities.

[18] Green S Operative Hand Surgery. EVOLUTION IN THE TREATMENT OF MANGLING INJURIES > Joints.

[19] Green S Operative Hand Surgery. Treatment of the Osteoarthritic Hand and Thumb > OSTEOARTHRITIS OF THE SMALL JOINTS OF THE HAND.