Forearm Fracture PDF
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Middle East University
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This document provides a detailed overview of forearm fractures. It covers various aspects of the condition, including its classification and treatment options.
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Forearm Fractur es Proximal Radioulnar joint (PRUJ) consists of the bony articulation between the radial head and the proximal ulna (lesser sigmoid notch). The annular ligament links the radius and ulna proximally; it is a circumferential band that arises and inserts on the...
Forearm Fractur es Proximal Radioulnar joint (PRUJ) consists of the bony articulation between the radial head and the proximal ulna (lesser sigmoid notch). The annular ligament links the radius and ulna proximally; it is a circumferential band that arises and inserts on the lesser sigmoid notch and wraps circumferentially around the radial head and neck, forming a strong ring. The radial head serves an important role as the primary constraint to longitudinal stability of the forearm. Distal Radioulnar joint (DRUJ) consists of the sigmoid notch on the radius with articular surface of the ulnar head articulates. Little bony stability exists between the distal radius and ulna; so, the soft tissues about the joint play a role. The main stabilizers of the DRUJ are the distal radioulnar ligaments (volar and dorsal radioulnar ligaments) and the triangular fibrocartilage complex (TFCC). TFCC is a soft-tissue made up of several structures which provide additional stability. The TFCC complex consists of the triangulofibrocartilage, extensor carpi ulnaris subsheath, the ulnar extrinsic ligaments. TFCC contributes 8% to the forearm’s overall mechanical stiffness. Interosseous membrane (IOM) The IOM consists of oblique fibrous tissue running from the radius to the ulna. Function of IOM 1. to link the bones (Radius and Ulna) 2. origin for musculature in the forearm 3. transferring load from the radius to the ulna. (from Radiocapal ---- humeroulnar). It is the primary stabilizer of longitudinal stability when the radial head is fractured or resected. Radius and Ulna Relation The radius rotates around a fixed ulna to allow forearm rotation, although this relationship —the ulnar head rotates distally. An intact radius reveals a gentle curvature or “bowing” of the radius which is critical to allow full pronation and supination of the forearm. Disorders of the shape of the radius, either congenital or acquired, will lead to limitations in the pronation and supination of the forearm. Ulnar variance The position of the apparent length of the ulnar head changes based on the position of the forearm. In neutral, ulnar head is equivalent length of the distal radius. Full pronation ulna appears longest (ulnar positive) Full supination in and shortest (ulnar negative). neutral wrist, 80% of the axial load is transmitted across the radiocarpal joint and 20% through the ulnocarpal joint. At the elbow the load is equilibrated via load transmission across t60% radiocapitellar he IOM from the radius to the ulna. Forces borne at the elbow are and 40% ulnohumeral. +ve Ulnar variance Positive ulnar variance increases the load transmitted through the distal ulnocarpal joint. Positive ulnar variance of 2 mm will increase the load transmission of the distal ulna from a normal 20% to 40% which may ultimately lead to ulnocarpal impaction and wrist pain Definition and classification Forearm fractures include fractures of the shaft of the radius, ulna, or combined fracture to the radius and ulna, typically called a “both-bone” fracture. Forearm fractures are classified according to Location (proximal third, middle third, or distal third), Fracture pattern (transverse, oblique, spiral, comminuted), segmental), Displacement (displaced or nondisplaced), Angulation (volar or dorsal and radial or ulnar) Angulation references the direction the distal segment moves in comparison to the proximal segment. Ulna fracture Midshaft ulnar fracture Minimally displaced treated with compression oblique middle 1/3 ulnar plate fixation shaft fracture Radius fracture Midshaft radius fracture Displaced oblique treated with compression fracture of the midshaft plate fixation. of the radius Both bone fracture Both-bone fracture of the Oblique displaced forearm treated with midshaft fractures of the compression plate radius and ulna both-bone fixation of both the forearm fracture radius and the ulna. Nightstick fracture Is isolated midshaft ulnar fracture. Mechanism of injury is typically a direct blow to the ulnar shaft, often while the patient is protecting the face or body from injury using the forearm. The term comes from the historical “nightstick” club carried as a compliance tool or defensive weapon by police or military personnel and associated injury caused by this device. Bony segments displaced by working muscles A proximal 1/3 radius fracture, between the insertion of the supinator and pronator teres muscles, leads to supination of the proximal fragment by the action of the supinator muscle and pronation of the distal fragment caused by the action of the pronator teres and pronator quadratus muscles. A distal 1/3 radius fracture leads to a proximal fragment held in neutral by the counteracting forces of the supinator and pronator teres. The distal fragment will pronate due to the pull of the pronator quadratus muscle. Special considerations Fractures of the ulna and radius require evaluation of the elbow and wrist,. AP and lateral radiographs of both joints should be obtained for all forearm fractures. Careful examination of the ulnar styloid and DRUJ should be performed. Ulnar styloid fractures + widening of the DRUJ are suggestive of DRUJ injury and help in diagnosing Galeazzi fractures. Distal radial shortening of ≥ 5 mm is associated with Galeazzi fractures. Prominence of the radial head, pain on radial head palpation, and ulnar shortening without a radius fracture are all associated with radial head subluxation or dislocation and indicate a Monteggia fracture. Treatment Nonoperative Nightstick fractures, nondisplaced fractures, or displaced fractures. splinting, bracing, or casting. immobilized for a period of 6 to 12 weeks based on clinical and radiographic progress. Operative Most forearm fractures will require surgical stabilization with open reduction and internal fixation. adult both-bone forearm fracture requires operative stabilization and is called a “fracture of necessity.” This is due to the divergent pull of the forearm musculature which makes maintaining a closed reduction almost impossible. Monteggia fracture/dislocation proximal or middle third ulnar fracture with dislocation of the radial head. The radial head may dislocate anteriorly, posteriorly, or laterally. In some instances, both the radius and the ulna may be fractured. Mechanism of injury: Injury is usually a result of fall onto an outstretched hand or a direct blow sustained in motor vehicle accident. One has to suspect for a Monteggia fracture when isolated ulnar fractures are seen, as they represent a higher degree of injury and may require prolonged recovery and rehabilitation. Monteggia fracture/dislocation classification Type Ⅰ Type Ⅱ Type Ⅲ Type Ⅳ anterior dislocation of posterior dislocation of lateral dislocation of the proximal or middle third the radial head the radial head radial head of both the ulna and radius with dislocation of the radial head in any direction. The posterior interosseous nerve (PIN) The posterior interosseous nerve (PIN) crossing the radial head on average between 3 and 5 cm from the radiocapitellar joint. With radial head dislocation, PIN may be injured from pull of the bone on the nerve. This leads to a neuropraxia resolves in 6 to 8 weeks. A Galeazzi fracture/dislocation is a radius fracture with disruption of the DRUJ. Fracture is in the middle to distal one-third of the radius as this location is more likely to cause disruption to the DRUJ. Mechanism of injury: Injury is typically a result of axial load with a torsional force. In order for DRUJ dislocation to occur, severe disruption of the TFCC is required. The Galeazzi is called a “fracture of necessity” because in this injury it is necessary to provide surgical intervention because of loss of correction and loss of bowing of the radius. Misdiagnosis or inadequate management can lead to complications DRUJ instability, malunion, limited forearm ROM, chronic wrist pain, posttraumatic arthritis. A Galeazzi fracture/dislocation Operative TTT Rehabilitation goals are improvement in swelling, pain, ROM, strength, return to preinjury function. most functional activities require 30° of elbow extension, 130° of elbow flexion, 50° of supination and pronation. Operat Precautions (ROM) ive TTT limit forearm rotation during the healing period. (4- 6 weeks) The most stable position for associated injuries of the forearm is with the forearm in supination. Monteggia fracture is immobilized in a long arm cast for 6 weeks. Newer protocols are treating with 2 weeks in splint while the wounds heal followed by active early flexion-extension of the arm at 2 weeks avoid Pronation and supination 6 weeks. Galeazzi injury is immobilized in an above-elbow cast with the forearm in supination for 6 weeks. New protocols use a protective splint for the first 1 to 2 weeks while wounds are healing and then start early motion including flexion/extension and pronation and supination at 2 weeks postoperatively Operat Week 0 to 2 ive TTT Rehabilitation goals: Rest surgical wound and repair site. Edema control and pain relief. Full digit and shoulder motion [AROM/AAROM/PROM]). Very gentle motion of forearm and elbow (AAROM only). Operat Week 2 to 4 ive TTT Rehabilitation goals: Edema control, scar mobilization by 2 weeks post suture removal. Light putty exercises by week 2 to 3. Full digit and shoulder motion (AROM/AAROM/PROM). Progress gentle motion of forearm and elbow, gentle isometrics by week 2 to 3. Operat Week 4 to 8 ive TTT Rehabilitation goals: Edema control, scar desensitization. Light use of operative arm for activities of daily living (ADLs). Full digit and shoulder motion (AROM/AAROM/PROM). Progress gentle motion of forearm and elbow focusing on pronation / supination, elbow and wrist flexion/extension, advancing gentle isometrics. Operat Week 8 to 12 ive TTT Rehabilitation goals: Full active and passive ROM exercises to all joints of the extremity while focusing on pronation and supination of the forearm. Putty and ball-squeezing exercises improve grip strength. Introduce gentle resistive exercises using weights in gradation Week 0 to 4 Conserva tive TTT Rehabilitation goals: Immobilized in cast/splint. Edema control of digits. Full digit and shoulder motion in all planes (AROM/AAROM/PROM). Very gentle motion of elbow if short arm cast flexion/extension only. No supination or pronation. Week 4 to 8 Conservat ive TTT Rehabilitation goals: Edema control. Once cast removed, desensitization. Light use of affected arm for ADLs. Full digit and shoulder motion (AROM/AAROM/PROM). Progress gentle motion of forearm and elbow focusing on pronation / supination, elbow and wrist flexion/extension, advancing gentle isometrics. Light putty and ball-squeezing exercises. Week 8 to 12 Conserva tive TTT Rehabilitation goals: Edema control. Full active and passive ROM exercises to all joints of the extremity while focusing on pronation and supination of the forearm. Putty and ball-squeezing exercises improve grip strength. Introduce gentle resistive exercises using weights in gradation.