Physical examination of wrist instabilities

Christian Dumontier

Institut de la Main, 6 square Jouvenet, 75016 Paris, France
& Consultant, Upper limb surgery Dpt, hôpital St-Antoine,
184 rue du Faubourg St-Antoine, 75012 Paris, France

This version is an update of the original version as Lou A. Gilula was very kind to correct the grammatical as well as the orthographic mistakes of the text. He also took of his time to partly rewrite this text. His advices and comments were very useful and I want to deeply thank him for his contributions. Some remarks have also been made by David M. Lichtman who sent me more details on the performance of the midcarpal shift test that he described. His drawings were not included in the original version of this work published in French in the number 49 of Maîtrise Orthopédique.


Although 35 years ago McLaughlin stated that wrist sprains were rare injuries, Linscheid and Dobyns's publication of 1972 [1] was the beginning of an enormous number of publications reporting either experimental or clinical work on wrist ligamentous injuries. Most of these injuries are diagnosed late, as early clinical signs are not specific, and plain X-rays are usually considered normal. Late radiographic deformations are no longer a problem for the orthopedic surgeon, but are indicative of advanced lesions whose treatment is still controversial. The main difficulty remains the chronically painful wrist despite normal X-rays. To deal with this problem, as frequent as it is frustrating, the surgeon must be aware that there may be a ligamentous wrist injury needing surgical treatment. Although all authors stress the importance of physical examination of the wrist, precise clinical details are seldom available. In this paper we will only deal with the clinical examination of ligamentous wrist injuries and will not discuss imaging techniques or therapeutic indications. Neither will we discuss soft tissue injuries of the wrist, which are much more frequent and may lead to a differential diagnosis in each case.

Ligamentous wrist injuries may arise in four joints: distal radioulnar, radiocarpal, midcarpal and carpometacarpal joint. Here we will the keep Anglo-Saxon term of wrist instability because it accurately describes the abnormal motion or alignment between the bones, although the correct term is "severe sprain". Wrist instability may appear after multiple microtraumas as in athletes, but it usually appears after a single trauma.
Physical examination is fundamental, as it focuses attention on ligamentous lesions which if left untreated, we believe will lead to degenerative arthritis. The surgical alternatives for degenerative arthritis carry high morbidity, and long-term follow-up is not yet available. Early surgical treatment allows "conservative" treatment, with lower morbidity, and satisfactory results. However, as pointed out by Gilula, this is still debatable as indications for surgery are not clear, and may lead to unsatisfactory results. It is a belief that early surgery may be easier to perform and will give better results.
Physical examination of an unstable wrist includes two types of evaluation: firstly, an objective evaluation of wrist function by measuring mobility and strength and conducting functional tests, and secondly, an attempt to delimit the painful zone and/or to detect abnormal motion between the carpal bones, in order to determine the diagnosis. Knowledge of wrist instability mechanisms and of bone and ligamentous wrist anatomy is a prerequisite for clinical examination, but will not be discussed here.


FUNCTIONAL EVALUATION OF THE WRIST

Mobility :

To test pronosupination, the patient is asked to keep his or her elbows close to the body and to turn the palm up and down alternatively. One arm of the goniometer is placed parallel to the axis of the humerus, and the other along the distal part of the forearm (Figure 1 & 2). One should avoid measuring pronosupination with a stick in the patient's hands, as the pronosupination mobility is increased by the passive rotatory mobility of the carpus, which may be as high as 40°. If the neutral prono-supination position is defined as zero (with the elbow flexed and maintained against the chest, the thumb must be raised up), normal pronation varies between 60 and 90°, and normal supination, between 45 and 80°. Flexion-extension mobility is measured by placing the goniometer on the palm for wrist extension, and along the dorsum of the hand for wrist flexion, over the axis of the third metacarpal bone (figure 3 & 4). Normal values vary among individuals and may reach 85° of flexion or extension. Ulnar inclination varies between 30 and 45°, and radial inclination, between 15 and 25°. Both inclinations are measured with one arm of the goniometer along the axis of the forearm, and the other along the axis of the third metacarpal, with the wrist in the neutral position of flexion or extension. These methods are simple and reproducible [2]

fig1

Figure 1:
Measurement of pronation: The vertical arm of the goniometer is placed in the axis of the arm and the horizontal arm on the dorsal surface of the wrist, but not the hand.

fig2

Figure 2:
Measurement of supination. The horizontal arm is placed on the volar surface of the wrist.

fig4

Figure 4:
Masurement of extension: The goniometer is placed anteriorly on the wrist.

Measurement of strength :

This should be done with a Jamar dynamometer, which is considered an international reference. Measurements should be done, either using each of the five handle positions, which is time-consuming, or using only one handle position, with three successive measurements. There are no standard values, and the contralateral hand serves as reference. The mean of three different measurements with maximum muscular contraction is noted. Usually, the curve for a single handle position is horizontal or slightly descending. Rapid alternating measurements changing from one hand to the other prevent patients from controlling their contraction and may reveal the absence of maximum contraction [3,4]. The dominant hand is usually 5 to 10% stronger than the non-dominant hand. The principles of key-pinch measurements are identical, but the measurements are less revealing for wrist instability. The functional tests will not be described in detail here as they are not conducted by French surgeons. Functional tests are usually performed by physical therapists who, in France, usually have a private practice. They are rarely done in practice, and never appear in scientific papers made by surgeons.


CLINICAL EXAMINATION OF THE WRIST

The normal wrist :

The key to correct examination of the wrist is precise location of the symptoms relating to the underlying anatomical structures, i.e., bones, articular spaces, ligaments or tendons. As in all clinical examinations, the most painful area is examined last. Comparative wrist examination is the rule, as there are no criteria of normality.

Conditions of examination :

The wrist must be examined with the forearm free of clothing and jewelry. For a satisfactory examination, the patient and the examiner should be comfortably seated. The ideal solution is to place the patient's forearm on a narrow examination table whose height may vary. In clinical practice, the easiest solution is to sit very close to the patient so that his or her hand rests on the examiner's knee, with the patient's elbow resting on his thigh (Figure 5). As pointed out by Lou Gilula, this may be a problem for potential sexual accusations in the USA. Buying a narrow table is probably less expensive than lawyer`s fees. Physical examination usually begins on the dorsal surface of the wrist, with pronation of the forearm and wrist flexion, whereas the ulnar surface of the wrist is examined during maximum elbow flexion. To move the wrist, the proximal hand of the examiner stabilizes the forearm while the distal hand moves the wrist. For palpation, the examiner stabilizes the wrist with both hands and uses his (her) thumbs to palpate the anatomical structures.

fig5

Figure 5:
A "practical" position for wrist examination.

Cutaneous projection of the anatomical structures

A beauty (the richness) of wrist examination is due to the fact that almost all bony, articular, tendinous or vascular structures may be palpated through the skin that covers it. To be compete, the physical examination should be methodical and whichever structure is examined first, the examination should cover the entire wrist.

Dorsal surface: Proximal to the wrist, proceding from the radius to the ulna it is easy to identify the radial styloid. One cm proximal you will palpate the sharp bony ridge which limits the first extensor compartment. More ulnar is a dorsal bump on the distal radius which is Lister's tubercle, around which passes ulnarly the extensor pollicis longus tendon (figure 6 & 7). Closer to the ulna and ulnar to Lister`s tubercle, one can feel the flat dorsal surface of the radius and the ulnar head which protrudes in pronation. On the ulnar side of the wrist, the ulnar styloid can be palpated dorsally in supination, at the ulnar and volar surfaces in pronation and on the ulnar side of the wrist in neutral rotation [4-6].

fig6

Figure 6:
To examine a wrist correctly, one should mentally project the bones onto the skin.

fig7

Figure 7:
Main palpable bony structures on the dorsal surface of the wrist (redrawn after [4].

At the level of the carpus, the anatomical snuffbox is easy to locate radially: it is limited radially by the extensor pollicis brevis and the abductor pollicis longus and ulnarly by the extensor pollicis longus. The scaphoid lies at the bottom of the snuffbox, with the radial artery crossing over it. In radial deviation the scaphoid disappears dorsally and one can palpate the scaphotrapezial joint palmarly (figures 8 & 9). Dorsally, at the distal end of the scaphoid there is a groove in which the examiner can place an index finger to palpate the trapezoid along the axis of the second metacarpal, and the trapezium along the axis of the first metacarpal [4]. The radial part of this groove, just ulnar to the extensor pollicis longus tendon, is what is termed the STT entry point (scaphotrapeziotrapezoidal) for mid-carpal arthroscopy (Figure 10). In the middle of the dorsal surface of the carpus, one centimeter distal to Lister's tubercle, lies the scapholunate interval. As pointed out by Lou Gilula, the scapholunate interval cannot be palpated unless the wrist is flexed. It would be usually better to say that the scapholunate interval can be palpated just distal to the dorsal rim of the radius at the level of Lister`s tubercle, with flexion of the wrist. Flexion moves the lunate dorsally out of the lunate fossa as shown figure 5. Just radial to that point, the proximal pole of the scaphoid can be palpated if the wrist is in flexion. Ulnar and distal to the scapholunate space lies a concavity which corresponds to the neck of the capitate (Figure 11). (French anatomists use the term “the crucifixion groove” as it represents the place where you should place your nails if you plan to crucify somebody...) When the wrist is flexed, the lunate and the head of the capitate are more easily palpable (Figure 12). Slightly radial to the neck of the capitate and one cm distal to the scapholunate interval is the radial entry point of the midcarpal space. The prominence of the third metacarpal base, the third metacarpal styloid, is located one to one and a half cm distal to that point, between the capitate and the trapezoid. It is more or less developed depending on the individual and may sometimes be hidden by the insertion of the extensor carpi radialis brevis tendon. When the wrist is in neutral position, with the third metacarpal in the axis of the radius i.e. without flexion or extension or radial or ulnar deviation, the ulnar head, triquetrum, hamate and fifth metacarpal form a continuous line on the ulnar side of the wrist

fig8

Figure 8:
The scaphoid lies at the bottom of the anatomical snuffbox and distal to it lies the scaphotrapezial joint. Palpation of bony structures varies during radial and ulnar deviation.

fig9

Figure 9:
The cutaneous projection of the anatomical snuffbox.

fig10 fig11

Figure 11: The posterior surface of the waist of the capitate is palpable through a depression easily found in the midportion of the dorsal surface of the wrist.




Figure 10:
The midcarpal joint can be palpated through the groove between the scaphoid and the trapezium and trapezoid bones.

fig12


Figure 12:
Wrist flexion allows palpation of the head of the capitate and the posterior horn of the lunate.

The triquetrolunate joint and triquetrum may be palpated during radial deviation of the wrist. The triquetrum is palpated just distal to the ulnar head and disappears with ulnar deviation. The triquetrohamate space whose mobility can be appreciated lies distal to the dorsal tubercle of the triquetrum (Figure 13). On the ulnar side of the wrist lies the "ulnar snuffbox" between the extensor and the flexor carpi ulnaris tendons. At the base of this snuffbox one can palpate the triquetrum during radial inclination, as well as the triquetrohamate joint distal to it, which is a drainage portal for mid-carpal arthroscopy (Figure 14).

fig13 fig14

Figure 14:
The posterior side of the triquetrum is easily found as one can palpate the insertional crest of the posterior radiotriquetral ligament. Just distal to the crest lies the triquetrohamate space.

Figure 13: The ulnar "anatomical snuffbox".

The palmar surface : The bony structures on this surface are too deep to be palpated. However, it is possible to palpate not only the radial and ulnar styloid processes but also, radially, the trapezial ridge which lies at the base of the thenar eminence, as well as the scaphotrapezial space and proximal to the distal tuberosity of the scaphoid [5,6] , when the wrist is in extension (Figure 15). Ulnarly, the pisiform is easily palpated, just distal to the distal wrist crease. The hamate hook (hamulus ossi hamatum) lies just along the radial edge of the pisiform, on a line from the pisiform to the second metacarpal head [7] (Figure 16). The articular spaces of the carpus are not accessible to palpation, but the radiocarpal joint is located at the level of the middle part of the proximal wrist flexion crease, while the midcarpal joint is located at the level of the middle of the distal flexion wrist crease [8].

fig15

Figure15:
Main palpable bony structures on the anterior side of the wrist (redrawn after [4].

fig16

Figure 16:
The hamulus ossi hamatum (hook of the hamate) is palpated deeply, 2 cm below the pisiform bone, on a line joining the pisiform to the head of the second metacarpal bone.

Soft tissues :

Using the bony structures as landmarks, almost all the tendinous, vascular and neural structures can be palpated. Their palpation is part of the normal examination of the wrist but will not be described in detail here. A complete examination is also performed as needed.

CLINICAL EXAMINATION OF THE UNSTABLE WRIST:

Most patients consult because of wrist pain, weakness or instability. These symptoms correspond to a wide pathological spectrum, from mild wrist sprain to chronic dissociative instability. Clinical instability varies greatly from one individual to another [9]. Examination of normal structures may sometimes be painful which explains why wrist examination should be compared to the opposite wrist. This examination must be rigorous, methodical, and systematic and includes five steps:

The first step is the description by the patient of the circumstances of the injury because knowledge of the impact point and exact wrist position during the impact may be indicative of the type of injury. Unfortunately, however, most patients are unable to recall the precise position of their wrist at the time of injury.

The second step is the patient's description of symptoms. Pain is the most frequent complaint and its characteristics, times of occurrence and alleviating or aggravating factors should be defined. Dynamic instability is painful during effort and may cause pain and/or synovitis which usually resolves in one or two days [9]]. With dynamic instability pain is generally of the same intensity from one day to another and may never completely disappear [7]]. Most authors consider that the exact location of pain is the most precise and specific sign for diagnosis. The clinician should ask the patient to localize the pain with one finger. The correlation between arthrographic radial perforation and radial pain is weak (49%) but is better for ulnar pain (88%) [10,11]]. This correlation is weaker still with bilateral wrist arthrograms, as almost 75% of the arthrographic perforations are bilateral and symmetric [12]]. During this part of the examination a simple test for pain can be conducted, like vigorously shaking patient's hand, but this is only of interest if the result is negative [13]. It is also a good sign if pain is induced by passive movements performed with slight traction, or by provocative maneuvers, or if pain disappears after injection of local anesthetics [3,14].
Loss of strength is usually the second most frequent complaint. It is often caused by fear of pain but if the pain is moderate, loss of strength is a good sign of wrist instability.

The third step in wrist examination is palpation and testing of each articulation and will be discussed in detail later. This step comprises a search for pain, abnormal motion, crepitus or swelling of the palpated zone.

The fourth step is an attempt to define any click or clunks reported by the patient. Benign wrist popping must be eliminated first. It is a frequent symptom consisting of a sharp noise which occurs during active movements. It is transient, with a period of latency, and reflects variations in the saturation of intra-articular gases. When a joint is stressed in certain positions gas in normal solution in the body can “pop” in the joint, causing a “pop” sound, much like some people produce when they “pop” or “crack” their fingers [Lou A. Gilula, personal communication]. Clicks or snaps are visible, audible and usually palpable, but there is a wide range of clinical signs which include a sensation of internal derangement and instability, and clicks, snaps or clunks. The patient is asked to reproduce the triggering movement, and the examiner then tries to reproduce the symptoms. With the patient's elbow resting on the table, the examiner holds the patient's hand, and by exerting axial pressure, realizes movements of flexion, extension, radial and ulnar inclination, and rotation. The so-called specific maneuvers described in the literature are designed to increase the mechanical constraints on ligaments in order to reveal pain, snaps or abnormal motion between bones. However, most of these maneuvers have not been validated for specificity or sensitivity and are only indicative of a potential pathology. During this stage of the examination the patient's laxity should be evaluated. This includes general laxity, i.e. elbow recurvatum and elbow valgus, the possibility of touching the forearm with the thumb during maximum flexion of the wrist, hyperextension of the MP joints, and also wrist laxity including:

(1) palmar sag of the wrist that you can see on the ulnar side which disappears if dorsal directed pressure is applied to the pisiform (Figures 17 a & b),

fig17a fig17b

Figure 17a,b: Spontaneous ulnar sag of the wrist in a lax young girl. By pushing on the pisiform this ulnar sag will be reduced. This test differentiates laxity from a posterior radioulnar dislocation.

(2) the anterior and posterior drawer tests in which the examiner exerts axial traction while holding the patient's forearm with one hand and the metacarpal heads with the other. In that position, anterior (palmar) or posterior (dorsal) displacement is usually of little amplitude. Lax patients display true subluxation which is usually located in the mid-carpal joint and is associated with a flexion deformity of the first row (VISI) during the anterior drawer test and a dorsal (DISI) deformity during the posterior drawer test [15]Jeanneret has shown that in slight ulnar deviation, most patients exhibit a positive anterior drawer test, which disappears in neutral, radial or full ulnar deviation [16]. As pointed out by Gilula, the lunate tilts more dorsally in full ulnar deviation, however the anterior drawer test disappears in that position .

fig18a fig18b

An anterior drawer test (18a). Usually the posterior drawer test is always more important than the anterior. The first row is placed in flexion during the anterior drawer test (18b, left side) and in extension during the posterior drawer test (18c, right side). In lax patients the distal carpal row subluxes palmar to the proximal carpal row.

(3) A mid-carpal, painless snap is present in one out of four individuals. This snap occurs when a wrist in slight flexion subjected to axial compression, is moved from radial to ulnar deviation. This movement places the first row in flexion and anterior translation. The mid-carpal snap occurs with the sudden displacement of the first row from the flexion position to the extension position (which also includes a posterior translation) that it should have in ulnar deviation. Some patients can reproduce this snap with active movements. The Lichtman's test or midcarpal shift test has been described by Lichtman [34]. To perform this test on the right wrist, the forearm is stabilized with the examiner's left hand and held in pronated position (figure 35a). With the patient's wrist in about 15° of ulnar deviation, the examiner's right hand grasps the patient's right hand and, with the thumb, exerts palmarly directed pressure at the level of the distal capitate (figure 35b). The distal row then palmarly translates and the proximal row assumes a VISI position (figure 35c). The wrist is then simultaneously axially loaded and ulnarly deviated resultng in sudden reduction of the midcarpal joint (figure 35d). A similar test exists for ulnar to radial deviation but its results are not usually as clear [8]. As pointed out by Lichtman, the midcarpal shift test is subjective and often difficult to quantify. Therefore he proposed a grading system based on 3 criteria; the force required to produce palmar translation, the quality of wrist clunk, and whether or not the patient can reproduce the clunk spontaneously. Grade I means no palmar translation and no clunk, grade II minimal palmar translation and minimal clunk, grade III moderate palmar translation and moderate clunck, grade IV maximum palmar translation and significant clunk, grade V self-induced palmar translation and self-induced clunk. Grade I-IV are considered to be increasing degrees of "normal" midcarpal laxity and can only be reproduced by the examiner. A grade v score represents the pathologic condition of midcarpal instability (Lichtman, personal communication). Hyperlaxity is common in patients with wrist instability and is considered an aggravating factor. If the radiographs are normal, the fifth step is to repeat the entire examination after an infiltration of local anesthetics in the painful zone. As in all clinical examinations, it may be necessary to trick a distressed or uncooperative patient. What are known as substitution maneuvers and distraction techniques are very helpful. They include simultaneous testing of multiple or bilateral muscles, and simultaneous exploration of different areas [13].

Before making a diagnosis, one should remember that although many lesions cause wrist pain, the frequency of ligamentous injury is small. Jones has shown that the frequency of scapholunate lesions was not more than 5% after wrist trauma [17]. Even after a single trauma, many painful wrists are due to a dorsal ganglion or to a dorsal impaction syndrome without instability [18]. On the other hand, although intracarpal injuries are only asymptomatic in 2% of cases, suggestive symptomatology was only correlated to anatomical lesions in half the cases reported by Truong et al. [10], and exhibited no statistical correlation according to Cantor [12]. Thus, out of 87 wrist arthroscopies for pain suggestive of wrist instability, 51 had an intra-articular ligamentous tear and 18, a TFCC defect. However, more than 70% of these defects were partial and involved no instability [19]. Others have found with arthroscopy that patients presenting with carpal instability symptoms had 2.7 ligamentous defects in the wrist, suggesting that our actual classification of lesions is inadequate [20]. However it is still uncertain which ligamentous defects are significant for symptoms or are just attritional due to age, prior injury, or degeneration. Lou A. Gilula suggests that we should not use the term “tear” as that implies traumatic incident , which is not always the case..

Scapholunate instability:

The mechanism of scapholunate injury includes a fall onto a hyperextended wrist with the forearm in pronation and the impact point on the thenar eminence [7,21]. Radial pain and progressive loss of strength are usual [21]. Loss of mobility appears much later. Patients may sometimes complain of a snapping wrist which usually occurs during the passage from radial deviation to neutral with the wrist in flexion. In ulnar deviation, the snap represents the action of the scaphoid on the lunate bone and the sudden correction of the proximal carpal row into dorsiflexion. With wrist flexion, a snap may represent penetration of the capitate into the scapholunate interval (rare), or the dorsal subluxation of the scaphoid on the posterior margin of the radius [ [5,6]. ]. Capitate popping is rare in Gilula's experience, and Gilula also pointed out that in the great majority of the cases with popping that he sees, fluoroscopic exam is normal and he does not know what ligaments or anatomic structures cause the popping. The popping seems to be related to moving of tendons or other soft tissue structures. Ulnar inclination combined with anterior translation places a load on the dorsal part of the scapholunate ligament and a snap may suggest partial tears [Masquelet, personal communication]. The snap may be reproduced during ulnar deviation combined with axial compression [22]. The various provocative maneuvers reported in the literature include the following:

(1) The synovial irritation sign of the scaphoid. To elicit this sign, pain is induced by exerting pressure on the scaphoid through the anatomical snuffbox [7,23] (Figure 19). This sign is usually positive in patients with scaphoid instability, but its specificity is very low.

fig19

Figure 19:
The synovial irritation test is performed by palpating the bottom of the anatomical snuffbox.

fig20

Figure 20:
The scapholunate ballottement test.

(2) The scaphoid bell sign. This is performed by palpation of the scaphoid tuberosity anteriorly through the radial groove while placing the index finger in the anatomical snuffbox. With ulnar deviation of the wrist, the anterior protrusion of the distal scaphoid tuberosity disappears and the proximal pole appears in the snuffbox. With radial deviation, the proximal pole disappears in the snuffbox and the protrusion of the distal scaphoid tuberosity reappears in the radial groove. Any disruption of this normal mechanism is suggestive of instability, but the sensitivity of this test seems very low [8].

(3) The scapholunate ballottement test. This test is designed to highlight any abnormal motion between the scaphoid and lunate bones. With one hand the examiner holds the scaphoid between his thumb (placed distally over the scaphoid tuberosity on the palmar side) and index finger (placed posteriorly and proximally over the proximal pole of the scaphoid). The other hand holds the lunate (Figure 20). The hands then move in opposite directions and appreciate the ballotement between the two bones. It may be difficult to appreciate instability as the normal laxity of the scapholunate joint varies greatly among individuals [5,6]. However, if the test induces pain, this is a good sign. This test, as all tests, may be compared to the opposite wrist to appreciate normal variations. Scapholunate ballottement is more marked when the wrist is in slight flexion, and, in this position, dorsal protrusion of the second row is sometimes visible [4,22]. Flexing the wrist also brings the lunate more dorsal and distal to the dorsal rim of the radius making it easier to palpate the lunate. Another technique to palpate the scapholunate interval is to place the index finger on the dorsal and distal pole of the lunate and then move the index finger radially while moving the wrist in flexion and extension. One can sometimes feel a groove corresponding to the scapholunate interval, or more often a slight protrusion of the proximal pole of the scaphoid [7]. The limitations of these tests are connected with the difficulty to hold the lunate bone correctly.

(4) The wrist-flexion finger-extension maneuver was described by Watson. With the elbow resting on the table, the wrist is placed in flexion and the patient is asked to extend the fingers. Application of pressure on the nails may reveal pain in the scapholunate interval [10,13] (Figure 21).

Figure 21:
The wrist-flexion finger-extension maneuver. This maneuver induces loads into the carpus that arouses pain at the scapholunate space.

(5) Watson's test or the scaphoid shear test [9,24]. The examiner and patient face each other as for arm wrestling. The examiner's fingers are placed dorsally on the distal radius, while the thumb is placed on the palmar distal tuberosity of the scaphoid. The other hand holds the metacarpals. Firm pressure is applied to the palmar tuberosity of the scaphoid while the wrist is moved in ulnar deviation which places the scaphoid in extension. While the wrist is moved in radial deviation the scaphoid cannot flex, as it is blocked from flexing by the examiner's thumb. In case of scapholunate tear, or in lax wrist patients, the scaphoid will move dorsally under the posterior margin of the radius and will reach the examiner's index finger, thus inducing pain (Figure 22). Sometimes this test may only be painful, without any perception of dorsal scaphoid displacement. When pressure on the scaphoid is removed, the scaphoid goes back into position with what Watson described as a "thunk" (a clunk) [24]. In certain patients, the absence of normal mobility compared to the uninjured wrist may be due to swelling and/or synovitis [9]. To avoid false-positive testing, the examiner should first place his fingers on the posterior surface of the scaphoid to detect spontaneous pain. Even though the Watson's test is the best known for scaphoid subluxation, its sensitivity and specificity are low. In two studies, this test proved positive in 20% of normal individuals [23,24]. In another study, the prevalence of a painless snap when removing thumb pressure was 32%, thus showing patient laxity. However, 14% of these lax patients were positive only in one wrist [25]. Lane suggested modifying the Watson's test by moving the scaphoid only from an anterior to a posterior position (he called it the Scaphoid shift test). This modification would enhance the test's sensitivity by using simple movements [26].

Figure 22: The Watson's test.

Lunotriquetral instability:

Lunotriquetral instability may appear after a hyperpronation injury [27,28], but more often after a hyperextension injury with an impact on the ulnar side [7,29,30]. Ninety per cent of patients complain of ulnar pain, and lunotriquetral joint palpation is usually painful [14,29,30]. Active prono-supination movements against resistance are painful if the resistance causes twisting of the carpus [29]. A feeling of instability or loss of strength is present in rare cases. A snap or clunk may be observed in half of the patients during ulnar deviation or extension [4-6,14,28,30]. The following tests are considered "specific":

The lunotriquetral ballottement test or Reagan's test (also called the Shuck or shear test, depending on the authors): as in the scapholunate ballottement test, the clinician holds the lunate bone between his thumb and index finger with one hand, and moves the triquetrum with the pisiform dorsal and palmar (Figure 23). The aim is to appreciate instability (very difficult) and above all the arousal of pain [30-32]. The sensitivity of this test varies from 33 to 100%, depending on the authors, and its specificity is still unknown.

Kleinman's shear test (which some authors call the shuck test!) (Figure 24): ): With the patient's forearm in a vertical position, the examiner places one finger on the posterior part of the lunate and with his contralateral thumb placed palmar, pushes the pisiform dorsal which arouses pain in the lunotriquetral joint [31,32]. This test might be more sensitive and more specific than the Reagan's test [32].

fig23

Figure 23:
The lunotriquetral ballottement test (Reagan's test)

fig24

Figure 24:
The Kleinman's test.

fig24

Figure 25:
The ulnar snuffbox compression test (Linscheid's test)

The ulnar snuff box compression test or Linscheid's test. This test may be the least specific according to Kleinman (Figure 25). The thumb placed on the ulnar side of the triquetrum exerts an axial pressure directed toward the lunate, which arouses pain [31 ].

The raised triquetrum test was recently proposed by Zradkovic and Sennwald (personal communication). The examiner holds the patient's hand proximal to the wrist and places his thumb on the triquetrum. From the neutral position, without flexion or extension, he performs radial and ulnar deviation movements and appreciates the dorsal and palmar movements of the triquetrum, which should be compared to those of the other wrist (Figures 26 a,b,c). The sensitivity and specificity of this test are still unknown, as are the anatomical lesions which cause the test to be positive. As pointed out by Gilula, the triquetrum is very prominent or dorsal with radial deviation, and moves palmarly and may even disapear with ulnar deviation. On plain radiographs, the triquetrum is located "onto" or proximal on the hamate with radial deviation (superposed), and "lateral" or ulnar to it with ulnar deviation (juxtaposed) [Laredo, personal communication].

fig26a fig26b fig26c
Figure 26: The raised triquetrum test (Photos G. Sennwald). In Fig 26a, the examiner places the wrist in radial deviation while palpating the triquetrum. He then moves the wrist in neutral (26b) and ulnar (26c) deviation to appreciate the depression of the triquetrum with ulnar deviation and prominence of the triquetrum with radial deviation that should be compared to the contralateral wrist.
Global first row instability:

This might reflect the spontaneous resolution of intra-carpal dislocations, thanks to the persistent efficacy of certain extrinsic ligaments [33]. Clinical examination reveals scapholunate and lunotriquetral signs of instability together with pain, loss of strength and mobility, and pain during extreme movements of the wrist [33]. Associated lesions of the TFCC are frequent [33].

Midcarpal instability:

The classification of these lesions is still controversial and they probably include distinct entities. According to some authors, the main lesion is ulnar and located on the hamatotriquetral joint [20,31,34,35]. Others believe that the lesion is located in the lunocapitate space [36,37]. Lastly Schernberg and Masquelet both reported ligamentous lesions [8,15,38]. The mechanism of such injuries is still unknown, but it seems that the radial, traumatic lesions are distinct from the central or ulnar lesions which are the most frequent, but do not seem to be triggered by trauma [31,34]. Hyperflexion or hyperpronation with extension constitute an aggravating mechanism [15,39]

Ulnar or central mid-carpal instability :
Most patients present with bilateral laxity, and one out of three has a painless mid-carpal snap in the healthy wrist [34]. Pain is located on the ulnar side and leads to functional impairment, loss of strength and loss of mobility [15,39]. The mid-carpal snap is the most revealing sign. It appears when patients make wrist movements with axial compression and is usually visible and audible (figure 27 a & b).

fig27a fig27b Figure 27a,b :
Radiographs of a midcarpal instability in which the proximal row suddenly moves from a flexed (27a) to an extended position (27b). The proximal carpal row is flexed in Fig 27a as demonstrated by the ring sign of the scaphoid; the lunate with its posterior, small and sharp horn is clearly visible; and the triquetrum is superposed to the hamate. In Fig 27b, the entire length of the scaphoid is visible in extension and the lunate presents its anterior, large horn. The triquetrum is juxtaposed on the hamate.

It is the same snap as the one found in patients with wrist laxity, but it is pathologic because it is painful [5,6,35]. This snap disappears if one places dorsally directed stress on the palmar surface of the pisiform, as this maneuver places the first row in extension. It also disappears during contraction of the hypothenar muscles. Other maneuvers have been described and they all provoke a snap, with shifting of one row onto the other and a zigzag deformity of the carpus. According to Johson et al., such maneuvers cause pain with dorsal translation of the capitate. They used fluoroscopy to verify the dorsal subluxation of the capitate [36]. ]. According to these authors, there is a traumatic lesion of the radiocapitate ligament. Louis placed the wrist in slight flexion while he exerted a traction. He then pressed on the distal tuberosity of the scaphoid and checked the results by fluoroscopy [37]. Louis reported that the 11 cases in his series displayed a double dorsal subluxation of the proximal carpus over the radius, and of the capitate over the lunate [37]. As only one patient was operated, the ligamentous lesion responsible was not clear, but Louis attributed it to weakening of the dorsal lunocapitate ligaments [37]. A triquetrohamate shear test has been described, in which the triquetrum is held between the thumb and index finger and pressure is applied dorsally on the palmar surface of the hook of the hamate [13] (Figure 28)

fig28

Figure 28: The triquetrohamate shear test.

Scaphotrapezial instability :
This rare injury is due to hyperextension of the wrist and thumb column, sometimes with an associated rotational injury [38,40]. The pain, located on the anterior side of the scaphotrapezial joint, is increased by forced extension of the thumb column. Pinch weakness, limited rotational movements of the thumb, and fatigue during writing have been reported [40]. Schernberg reported one case in which the mechanism of injury was a forced flexion with traction loading [15,39]. A ballottement test combined with compression can be applied to the scaphotrapezial joint. The examiner holds the trapezium and trapezoid with one hand and moves the scaphoid with the other [13]. This test is different, but close to, the scaphoid compression test described by S.C. Chen to detect scaphoid fractures (J.Hand.Surg.Br. 1989;14:323) and its sensibility is probably rather low for Scaphotrapezial instability .

Distal radioulnar joint (DRUJ) instability :

As the ulna is fixed, the radius is the dislocated bone, but we have kept the usual convention which describes "dislocation of the ulna". A traumatic movement in supination is responsible for anterior DRUJ instability, while posterior DRUJ instability follows a pronation injury. Dorsal ulnar dislocation is responsible for loss of supination and protrusion of the ulnar head. In case of dorsal ulna subluxation, the protrusion of the ulnar head may be clearly visible when viewed laterally, and unlike what occurs in the normal wrist, does not disappear if the injured wrist is flexed [8]. Anterior ulnar dislocation makes the dorsal skin depress and limits pronation. In anterior subluxation, the usual protrusion of the ulnar head is reduced or disappears [8]. Pain secondary to DRUJ instability is located on the ulnar side of the wrist and is intensified by pronation or supination. In such cases the examiner stabilizes the patient's forearm with one hand while with the other hand, he grasps the patient's hand as if for a vigorous handshake. When the patient resists forced passive rotation, or when there is active rotation against resistance, pain usually is elicited. If the pain is caused by compressing the ulna against the radius, it is mostly suggestive of chondromalacia [3,15]. Patients may also complain of a snap which occurs during pronation or supination and corresponds to either dislocation of the ulnar head or to its reduction. Radioulnar instability is tested by the radioulnar ballottement test, in which the patient's elbow is flexed, and the examiner uses his thumb and index finger to stabilize the radius radially and the ulnar head ulnarly (Figure 29). Normally, there is no mobility in the anterior or posterior direction in maximum pronation or supination. Pain or mobility is very suggestive of radioulnar instability. The ballottement test must not only be done during extreme motions of pronation and supination, but also in various intermediate pronation and supination positions, because instability may only appear in some of these positions. It is sometimes possible to mobilize the ulnar head medially with two fingers [13]. As for other tests it is useful to compare with the opposite wrist to help detect normal variation.

TFCC lesions are usually of degenerative origin, but may also constitute the first stage of radioulnar instability. Pain is always ulnar and is intensified by wrist movements but not necessarily by pronation or supination. It is usually aggravated by ulnar inclination or rotational loads: thus, in the screwdriver test, the examiner holds the patient's hand while performing screwing and unscrewing movements [13,15]. Extensor carpi ulnaris tendon dislocation is not a ligamentous injury but occurs after combined hypersupination and ulnar inclination [15]. Passive pronation and supination are usually painful and may be accompanied by a visible and palpable snap which can be reproduced by placing the wrist in flexion and supination [7] (Figure 30).

fig29

Figure 29:
The radioulnar ballottement test.

fig30

Figure 30:
Displacement of the extensor carpi ulnaris is more visible when the wrist is placed in flexion and supination.

Radiocarpal instability:

This very rare condition usually seems to follow an injury associating hyperextension, ulnar deviation and a rotational torque [41]. The most severe lesions are sequelae of radiocarpal dislocation. Patients present with a positive ulnar drawer test and/or a positive anterior drawer test [42,43] (Figure 31). Schernberg reported radiocarpal instability following less severe injuries caused by stretching of the posterior radiotriquetral ligament. Patients presented with an ulnar radiocarpal drawer test which was sometimes painful [8]. For the anterior drawer test, the examiner's thumb pushes on the dorsal surface of the triquetrum in a volar direction and then, for the posterior drawer test, the thumb pushes dorsally on the anterior surface of the pisiform. Counter-pressure is exerted by the pulp of the index and long fingers of the same hand, which are placed on the anterior then the posterior surface of the radius. In patients with radiocarpal instability there is also an increased ulnocarpal sag, which is reduced during the posterior drawer test, thus confirming its radiocarpal origin. A click may sometimes occur during ulnar deviation but it disappears if a posterior drawer test is applied [8].

fig31

Figure 31:
Spontaneously reduced radiocarpal dislocation. Major ulnar translation is present.

fig32

Figure 32:
Pisiform grinding test. This maneuver is painful in pisiform instability but also in pisotriquetral arthritis which is more frequent.

Pisotriquetral instability:

Pisotriquetral pain is usually of degenerative origin. A fall with the wrist in extension and ulnar deviation may induce acute instability [44]. Chronic pisotriquetral instability is rare and is usually seen in racket players. Pain is increased by the pisiform ballottement test: With the wrist in slight flexion and ulnar deviation to relax the flexor carpi ulnaris tendon, the pisiform is mobilized over the triquetrum [45,46] (Figure 32).

fig35

Figure 35: The midcarpal shift test or Lichtman's test:

To perform this test on the right wrist, the forearm is stabilized with the examiner's left hand and held in pronated position (figure 35a). With the patient's wrist in about 15° of ulnar deviation, the examiner's right hand grasps the patient's right hand and, with the thumb, exerts palmarly directed pressure at the level of the distal capitate (figure 35b). The distal row then palmarly translates and the proximal row assumes a VISI position (figure 35c). The wrist is then simultaneously axially loaded and ulnarly deviated resultng in sudden reduction of the midcarpal joint (figure 35d). This test is only positive if a painful clunk occurs with passive ulnar deviation that reproduces the patient's symptoms.

Carpometacarpal instability:

This usually follows a fall with the wrist in hyperflexion. Pain is usually located at the base of the metacarpals. It is revealed or increased if the examiner squeezes the metacarpals [13] (Figure 33). Linscheid's test also increases pain [7]: in this test the examiner stabilizes the second row of the carpus with one hand, while he pushes up and down on the metacarpals with the other [4] (Figure 34). For the mobile 4th and 5th metacarpals, compression and/or translation testing can also be performed to reveal pain [13].



Acknowledgements:
To Eric Lenoble, M.D. and Pr. Alain Charles Masquelet, M.D. who reviewed the first versions and to Angèle Travadel for her drawings.


References

1.Linscheid R.L., Dobyns J.H., Beabout J.W., Bryan R.S. Traumatic instability of the wrist: diagnosis, classification, and pathomechanics: J Bone Joint Surg Am 1972; 54-A:1612-1632.

2.Solgaard S., Carlsen A., Kramhoft M., Petersen V.S. Reproducibility of goniometry of the wrist: Scand J Rehab Med 1986; 18:5-7.

3.Lister G. The Hand:Diagnosis and indications. 3ème Ed. Edinburgh: Churchill Livingstone, 1993.

4.Linscheid R.L., Dobyns J.H. Physical examination of the Wrist. In: Post M. ed. Physical examination of the musculoskeletal system. Chicago: Year Book Medical publishers; 1987: 80-94.

5. Masquelet AC: [Clinical examination of the wrist]. Ann Chir Main. 1989; 8: 159-175.

6.Masquelet A.C. Examen clinique du poignet: Cahiers d’enseignement de la société Française de chirurgie de la main 1994; 6:101-121.

7.Beckenbaugh R.D. Accurate evaluation and management of the painful wrist following injury. An approach to carpal instability: Orthop Clin North Am 1984; 15:289-306.

8.Schernberg F. Le poignet-anatomie radiologique et chirurgie. Paris: Masson, 1992.

9.Watson H.K., Black D.M. Instabilities of the wrist: Hand Clin 1987; 3:103-111.

10.Truong N.P., Mann F.A., Gilula L.A., Kang S.W. Wrist instability series: increased yield with clinical-radiologic screening criteria: Radiology 1994; 192:481-484.

11.Manaster B.J., Mann R.J., Rubenstein S. Wrist pain: correlation of clinical and plain film findings with arthrographic results: J Hand Surg Am 1989; 14:466-473.

12.Cantor R.M., Stern P.J., Wyrick J.D., Michaels S.E. The relevance of ligament tears or perforations in the diagnosis of wrist pain: an arthrographic study: J Hand Surg Am 1994; 19:945-953.

13.Gilula LA, Yin Y. Imaging of the Wrist and Hand. Philadelphia: W.B. Saunders, 1996.

14. Green DP: The sore wrist without a fracture. Instr Course Lect. 1985; 34: 300-313.

15.Taleisnik J. Pain on the ulnar side of the wrist: Hand Clin 1987; 3:51-68.

16.Jeanneret B., Buchler U. Snapping palmar drawer phenomenon of the wrist: a physiologic or pathologic study finding? Handchir Mikrochir Plast Chir 1988; 20:111-112.

17.Jones W.A. Beware the sprained wrist. The incidence and diagnosis of scapholunate instability: J Bone Joint Surg Br 1988; 70:293-297.

18. Dauphine RT, Linscheid RL Unrecognized sprain patterns of the wrist. J Bone Joint Surg Am. 1975; 57-A: 727.

19. Ruch DS, Siegel D, Chabon SJ, Koman LA, Poehling GG Arthroscopic categorization of intercarpal ligamentous injuries of the wrist. Orthopedics. 1993; 16: 1051-1056.

20. Fischer M, Sennwald G [Value of arthroscopy in diagnosis of carpal instability]. Handchir Mikrochir Plast Chir. 1993; 25: 39-41.

21. Taleisnik J The Wrist. Churchill Livingstone, New York, 1985

22. Linscheid RL: Scapholunate ligamentous instabilities (dissociations, subluxations, dislocations). Annales de Chirurgie de la Main. 1984; 3: 323-330.

23. Tiel van Buul MM, Bos KE, Dijkstra PF, van Beek EJ, Broekhuizen AH: Carpal instability, the missed diagnosis in patients with clinically suspected scaphoid fracture. Injury. 1993; 24: 257-262.

24. Watson HK, Ashmead D4, Makhlouf MV: Examination of the scaphoid. J Hand Surg Am. 1988; 13: 657-660.

25. Easterling KJ, Wolfe SW: Scaphoid shift in the uninjured wrist. J Hand Surg Am. 1994; 19: 604-606.

26. Lane LB: The scaphoid shift test. J Hand Surg Am. 1993; 18: 366-368.

27. Taleisnik J: Current concepts review. Carpal instability. J Bone Joint Surg Am. 1988; 70: 1262-1268.

28. Lichtman DM, Noble WH, Alexander CE: Dynamic triquetrolunate instability: case report. J Hand Surg Am. 1984; 9: 185-188.

29. Pin PG, Young VL, Gilula LA, Weeks PM: Management of chronic lunotriquetral ligament tears. J Hand Surg Am. 1989; 14: 77-83.

30.Reagan D.S., Linscheid R.L., Dobyns J.H. Lunotriquetral sprains: J Hand Surg Am 1984; 9:502-514.

31.Ambrose L., Posner M.A. Lunate-triquetral and midcarpal joint instability: Hand Clin 1992; 8:653-668.

32. Kleinman WB. Wrist reconstruction: pitfalls. 1993;1-13.(Abstract)

33. Pin P.G., Nowak M., Logan S.E., Young V.L., Gilula L.A., Weeks P.M. Coincident rupture of the scapholunate and lunotriquetral ligaments without perilunate dislocation: pathomechanics and management: J Hand Surg Am 1990; 15:110-119.

34.Lichtman D.M., Bruckner J.D., Culp R.W., Alexander C.E. Palmar midcarpal instability: results of surgical reconstruction: J Hand Surg Am 1993; 18:307-315.

35.Lichtman D.M., Schneider J.R., Swafford A.R., Mack G.R. Ulnar midcarpal instability-clinical and laboratory analysis: J Hand Surg Am 1981; 6:515-523.

36.Johnson R.P., Carrera G.F. Chronic capitolunate instability: J Bone Joint Surg Am 1986; 68-A:1164-1176.

37.Louis D.S., Hankin F.M., Greene T.L., Braunstein E.M., White S.J. Central carpal instability-capitate lunate instability pattern: Orthopedics 1984; 7:1693-1696.

38.Masquelet A.C., Strube F., Nordin J.Y. The isolated scapho-trapezio-trapezoid ligament injury. Diagnosis and surgical treatment in four cases: J Hand Surg Br 1993; 18:730-735.

39. Schernberg F: [Mediocarpal instability]. [French]. Annales de Chirurgie de la Main. 1984; 3: 344-348.

40.Kuhlmann J.N., Mimoun M., Fahed I., Boabighi A., Baux S. [Severe and inveterate internal scapho-trapezial ligament sprain. Apropos of an unusual case]: Ann Chir Main Memb Super 1992; 11:62-65.

41.Dumontier C., Lenoble E., Saffar P. Radiocarpal dislocations and fracture-dislocations. In: Saffar P., Cooney W.P.3. eds. Fractures of the distal radius. London: Martin DUNITZ; 1995: 267-278.

42.Bellinghausen H.W., Gilula L.A., Young L.V., Weeks P.M. Post-traumatic palmar carpal subluxation. Report of two cases: J Bone Joint Surg Am 1983; 65:998-1006.

43.Rayhack J.M., Linscheid R.L., Dobyns J.H., Smith J.H. Posttraumatic ulnar translation of the carpus: J Hand Surg Am 1987; 12:180-189.

44.McEwen Smith A. Sprain of the pisiform-triquetral joint: J Bone Joint Surg Br 1954; 36B:618-621.

45.Helal B. Racquet player’s pisiform: The Hand 1978; 10:87-90.

46.Nüesch B., Sennwald G., Segmüller G. Pisiformexstirpation: indikation und resultate: Handchir Mikrochir Plast Chir 1993; 25:42-45.