Wrist Injuries. Part 1: Pinpointing Pathology in a Complex Joint
Eric W. Honing, MD
The Recreational Athlete
THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 9 - SEPTEMBER 2021
This is the first in a series of articles discussing the problems of adult recreational athletes. The second, on spotting and treating injuries, appears in October.
In Brief: The wrist is a complex joint and a common site for injury in virtually every type of recreational activity. This article describes a workup that will lay the groundwork for a diagnosis more specific than wrist sprain or strain. Instructions are given for taking a detailed history, palpating the five zones of the wrist, performing provocative maneuvers, giving diagnostic injections, and obtaining imaging studies. Plain x-rays of both wrists may be sufficient to diagnose a fracture or subluxation, but if x-rays are negative and a fracture is still suspected, other imaging studies may be needed. Diagnosis and management of wrist injuries will be described in part 2.
The wrist is one of the most complex and least understood joints in the body (see "Anatomy of the Wrist," below). Its complexity can produce a sense of despair when a patient presents with wrist pain; in fact, it has been called the "'back' of the upper extremity (1)."
The wrist and hand are the most common sites for upper-extremity injuries in sporting activities (2), which can include common leisure sports such as basketball, soccer, mountain biking, skiing, golf, and racket sports. Because of this, primary care physicians working with these active patients need a thorough, up-to-date understanding of the wrist and must be able to take a good history and perform a comprehensive exam of the wrist. This will allow the physician to determine the exact cause of injury and the active patient to return to sports activity as quickly as possible.
To reach the specific diagnosis of a wrist injury, the clinician should use a systematic and detailed approach. The ability to correlate the history with the physical exam will enable the examiner to formulate a differential diagnosis and to begin a treatment plan or select further investigative studies.
Taking the History
A detailed history is the cornerstone of a specific diagnosis or a focused differential. The history should include information regarding the patient's age, handedness, chief complaint, occupation, previous wrist injury or surgery, exact onset of symptoms and their relationship to specific activities, factors that exacerbate or improve symptoms, frequency and duration of postactivity pain, and subjective loss of wrist motion.
Four principal mechanisms of injury have been described: throwing, weight bearing, twisting, and impact (3). Any of these mechanisms can cause either traumatic or overuse injuries involving bones or soft tissue, including nerves and vasculature.
Acute injuries. With an acute wrist injury, it is important to determine the position of the wrist at the time of injury. Was the wrist flexed or extended? Did rotation occur?
In addition, the location, intensity and duration of pain should be determined. Information should be obtained about the presence of swelling, decreased motion, and burning or tingling sensations.
Chronic injuries. Chronic injuries are frequently caused by throwing and racket activities, as well as weight-bearing events such as gymnastics.
The frequency with which pain occurs and any particular movements or activities that aggravate or alleviate the pain must be determined. Also, information regarding amount of practice time and use of any splinting or taping should be sought. The efficacy of prior treatments helps guide future treatment alternatives.
The patient should also be questioned about any abnormal sounds or sensations associated with wrist motion. These are usually described by the patient as "grinding," "snaps," "clicks," or "clunks." Typically, grinding represents synovitis, while clunking and clicks signal carpal instability. A snap usually represents a subluxing tendon or plica.
General history. After completing a thorough history of the patient's wrist problem, the clinician should complete a thorough general history, including other orthopedic or rheumatologic disorders. Diabetes or thyroid dysfunction may play a role in wrist pain.
After the history, the next step is a thorough physical examination of the wrist.
It is important to obtain complete relaxation of the patient's forearm, wrist, and hand while performing the exam. This can be accomplished by having the patient rest the wrist and elbow on a thigh or a low table. With an acute injury, the patient's involved extremity should be positioned flat on a soft examining table. The exam should consist of inspection, range-of-motion testing, palpation, provocative maneuvers, and differential injections.
It is important to use the opposite wrist as a control for assessing range of motion, swelling, and any subtle losses. Any asymmetry between the injured wrist and the normal wrist should be noted. The presence of swelling, nodules, masses, erythema, abrasions, lacerations, and deformities should be recorded.
Passive and active range of motion, including extension, flexion, and radial and ulnar deviation of both wrists, should be evaluated. The difference between passive and active motion will become important when assessing the patient's response to therapy. Evaluation of elbow, shoulder, and neck range of motion may also be necessary to rule out other injuries. Any abnormal noises or pain that occur during the motion testing will help localize the site of the pathology.
Systematic palpation. Palpation of the wrist should be done in an organized and systematic manner. This is achieved by dividing the wrist into five zones: radial dorsal, central dorsal, ulnar dorsal, radial volar, and ulnar volar (1).
Radial dorsal zone. The first zone to be palpated is the radial dorsal zone (figure 1: not shown). This zone is composed of both bone and soft tissues.
The palpable bony features are the radial styloid, the scaphoid, the scaphotrapezial joint, the trapezium, the base of the first metacarpal, and the first carpometacarpal (CMC) joint. The waist of the scaphoid is palpable deep in the anatomic snuffbox, and tenderness here may be caused by an occult scaphoid fracture or a scaphoid nonunion.
Distal to the scaphoid is the scaphotrapezial joint and the trapezium. Farther distally, the first CMC joint is easily identified. Pain and crepitation are present with arthrosis of this joint. The grind test, performed by applying axial pressure to the thumb while palpating the first CMC joint, is positive when there is CMC arthrosis.
The soft-tissue structures in the radial dorsal zone are the tendons of the first dorsal compartment, which is composed of the abductor pollicis longus and extensor pollicis brevis tendons. Inflammation of these tendons is known as de Quervain's tenosynovitis.
The other soft-tissue structures in this zone are the extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB) tendons, which make up the second compartment. The junction of the first and second compartments can be the site of a peritendinous inflammation; this condition is called intersection syndrome.
Central dorsal zone. The second zone is called the central dorsal zone (figure 2: not shown). The bony structures here include Lister's tubercle, the scapholunate joint, the lunate, the capitate, and the base of the second and third metacarpals and their CMC joints.
The lunate, found distal and ulnar to Lister's tubercle, becomes more prominent when the wrist is held in flexion. When this is painful in the absence of any specific trauma, one should think of Kienböck's disease, which is also called idiopathic osteonecrosis.
The scapholunate joint is marked by a depression between the lunate and the scaphoid. Tenderness, clicking, or an increase in the size of the scapholunate depression may indicate a scapholunate dissociation. Tenderness may also be secondary to an occult ganglion, which is a common cause of chronic wrist pain.
The capitate is found just distal to the lunate. The second and third metacarpals and their respective carpometacarpal joints can be identified as well.
The soft-tissue structures in the central dorsal zone are the distal aspects of the extensor carpi radialis longus (ECRL) and brevis (ECRB), the extensor pollicis longus, and extensor digitorum communis tendons. The ECRL and ECRB tendons are located immediately radial and distal to Lister's tubercle. Just ulnar to the tubercle is the extensor pollicis longus tendon, which becomes more prominent when the thumb metacarpophalangeal and interphalangeal joints are extended. The extensor digitorum communis tendons are located ulnar to the extensor pollicis longus, and tenderness in any of these tendons may be due to inflammation.
Ulnar dorsal zone. The bony structures in the ulnar dorsal zone (figure 3: not shown) are the ulnar styloid, the distal radioulnar joint, the triquetrum, the hamate, and the bases of the fourth and fifth metacarpals. The distal radioulnar joint can become painful with forearm rotation and squeezing of the radius and ulna together, indicative of disease.
The hamate is proximal to the base of the fifth metacarpal. With the wrist in radial deviation, the triquetrum can be found in the sulcus between the hamate and the ulnar styloid. In a patient with midcarpal instability, localized pain, swelling, and tenderness are most noticeable in this area.
The important soft-tissue structures located in the ulnar dorsal zone are the triangular fibrocartilage complex (TFCC) and the extensor carpi ulnaris (ECU) tendon. The TFCC lies immediately distal to the ulnar head; acute tears of the TFCC cause exquisite tenderness in this area. The ECU tendon is located ulnar to the ulnar styloid, and becomes quite prominent in supination and active ulnar deviation.
Radial volar zone. Volarly, there are two zones. In the radial volar zone (figure 4: not shown), bony structures that should be palpated are the scaphoid tuberosity and the tubercle of the trapezium. The scaphoid tuberosity can be palpated just distal to the radial styloid, and becomes prominent when the wrist is radially deviated. Distal to the scaphoid is the trapezial ridge and tubercle.
The soft-tissue structures in the radial volar zone are the flexor carpi radialis (FCR), the palmaris longus, the long finger flexors, and the median nerve.
The FCR tendon is located ulnar to the scaphoid tuberosity, and with FCR tendinitis, pain can be elicited with resisted flexion or radial deviation. The palmaris longus tendon lies ulnar to the FCR, and is present in 87% of upper limbs (4).
The median nerve is located deep and radial to the palmaris longus tendon, and is involved in the well-known carpal tunnel syndrome. A positive Tinel's sign occurs when light percussion over this area results in a tingling sensation.
Ulnar volar zone. The last zone is the ulnar volar zone (figure 5: not shown). The pisiform, the hook of the hamate, the ulnar nerve and artery, and the tendon of the flexor carpi ulnaris are located within this zone.
The bony prominence located at the base of the hypothenar eminence is the pisiform, which is mobile when the wrist is relaxed. The hook of the hamate can be palpated slightly radial to the pisiform. If the hook of the hamate is tender in a patient who participates in a sport that involves a club, bat, or racket, a fracture should be suspected.
Alongside the pisiform and the hook of the hamate radially lie the ulnar nerve and artery, located within Guyon's canal. A small ganglion in the canal can cause neurologic symptoms in a distal ulnar nerve distribution.
The flexor carpi ulnaris tendon is identified by having the patient flex and ulnarly deviate the clenched fist.
Provocative maneuvers. Several provocative maneuvers have been described to help identify certain conditions (figures 6-11).
Grip testing with the hand dynamometer will also help gauge injury severity when the injured hand is compared with the uninjured hand. Keep in mind that the dominant hand is about 10% stronger than the nondominant hand.
A short-acting local anesthetic such as lidocaine hydrochloride, with or without corticosteroids, can be injected to confirm the location and source of the patient's pain. Injection into the first dorsal compartment can help distinguish de Quervain's tenosynovitis from an occult scaphoid fracture, with pain relief pointing to de Quervain's tenosynovitis. Injection into the ulnar carpal joint or TFCC will help distinguish a TFCC tear from ECU tendinitis. Pain relief indicates a TFCC injury. The pisotriquetral joint can also be injected to distinguish pisotriquetral arthrosis from flexor carpi ulnaris tendinitis. Pain relief points to pisotriquetral arthrosis.
Imaging studies of the wrist should always start with plain radiographs, including anteroposterior (AP), oblique, lateral, and AP ulnar deviation views. Comparison x-ray views of the uninjured wrist are beneficial when assessment of rotation or instability patterns is needed. If a fracture of the hook of the hamate is suspected, a carpal tunnel or supinated oblique view is indicated.
When plain films appear normal but a fracture or dislocation is still strongly suspected, the next step is a three-phase bone scan. This imaging study is especially important for diagnosing subtle scaphoid fractures. Other methods for evaluating acute fractures are computed tomography and magnetic resonance imaging (MRI).
If a tear of the TFCC is strongly suspected, a three-compartment wrist arthrogram should be considered; however, MRI has increasingly been used in place of wrist arthrography to evaluate the integrity of the TFCC. Several cadaver studies have supported the use of MRI (1).
As with other studies, the MRI findings must be interpreted with care, and clinical correlation is a must.
Wrapping Up the Diagnosis
Although wrist injuries may still seem a black box, most cases of wrist pain will yield a diagnosis after review of a careful medical history, thorough physical examination, and appropriately selected plain radiographs. Further testing can be helpful, although it is important to remember that not all abnormal findings are clinically significant, and they must be correlated with the results of the medical history and physical exam.
Anatomy of the Wrist
The wrist is a complex joint that biomechanically transmits forces generated or applied through the hand to the forearm (1). The radial side of the wrist carries 80% of the actual load, the ulnar side the remaining 20%.
The wrist is composed of the distal radius and ulna, the distal radioulnar joint, the radiocarpal and ulnocarpal joints, the carpometacarpal joints, and the rows of carpal bones (figure A: not shown). In all, there are eight carpal bones, seven of which are assigned into proximal and distal rows. The scaphoid is the bridge between the two carpal rows on the radial side.
The stability of the wrist depends on multiple ligaments that help guide the excursion of the carpal bones.
Dr Honing is the head team physician at Utah State University and director of sports medicine and occupational medicine at Western Orthopaedics and Sports Medicine, both in Logan, Utah. He is a member of the American College of Sports Medicine (ACSM) and the American Medical Society for Sports Medicine (AMSSM). Dr Moeller is an assistant residency director and director of sports medicine in the William Beaumont Hospital Family Practice Residency Program in Troy, Michigan, a member of the ACSM and AMSSM, and a member of the editorial board of The Physician and Sportsmedicine. Address correspondence to Eric W. Honing, MD, Western Orthopedics and Sportsmedicine, 850 E 1200 N, Logan, UT 84341; e-mail to [email protected].
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