MusculoSkeletal Exam

EDQ tendinitis

ECU tendinitis, subluxation

EIP syndrome

Lateral epicondylitis

Trigger

finger

EPL tendinitis

Intersection syndrome

Digital flexor tendinitis

FCU tendinitis, calcification

Medial epicondylitis

Pain over the radial styloid process is pathognomonic of de Quervain’s syndrome. Arthritis of the first carpometacarpal joint will also sometimes cause pain with the maneuver.

Tenosynovitis of the hand and wrist is encountered frequently. Tenderness to palpation is noted in characteristic locations (Figure 10.100). Passively stretching the involved muscle will also produce pain.

Tests for Flexibility and Stability of the Joint

Bunnel–Littler Test (Intrinsic Muscles Versus

Contracture)

This test is useful in determining the cause of restricted flexion of the proximal interphalangeal joints of the fingers (Figure 10.101). A limitation in flexion at these joints may be caused by tightness of the intrinsic muscles (interossei and lumbricals) or secondary to contracture of the joint capsule. The purpose of the test is to put the finger in a position of relaxation of the intrinsic muscles by flexing the metacarpophalangeal joint. Attempt to flex the proximal interphalangeal joint (Figure 10.102). If the joint can be flexed then the difficulty in flexion with the metacarpophalangeal joint extended is due to tightness of the intrinsic muscles. If a joint contracture is present, relaxing the intrinsic muscles will have no effect on the restricted mobility of the proximal interphalangeal joint and you will be unable to flex this joint in any position of the finger (Figure 10.103).

Retinacular Test

The retinacular test is used to determine the cause of the patient’s inability to flex the distal interphalangeal joint. This inability may be caused by either joint contracture or tightness of the retinacular ligaments. Hold the patient’s finger so that the proximal interphalangeal and metacarpophalangeal joints are in neutral position. Now support the finger and attempt to flex the distal interphalangeal joint (Figure 10.104). If the distal interphalangeal joint does not flex, perform the retinacular test by initially flexing the proximal interphalangeal joint to relax the retinacular ligaments (Figure 10.105). Now try to flex the distal interphalangeal joint with the ligaments relaxed. If the distal interphalangeal joint still does not flex there is a contracture of the distal interphalangeal joint.

Scaphoid-Lunate Dissociation (Watson’s) Test

This test is used to diagnose abnormal separation of the lunate and scaphoid bones (Figure 10.106). The normal separation should be less than 2 mm. Increased separation due to a fracture displacement causes disruption of the wrist and can lead to arthritis. This test result is difficult to interpret. Stabilize the patient’s radius with one hand while your thumb presses

Chapter 10 The Wrist and Hand

Attempt to flex DIP joint with MCP and PIP in neutral

Figure 10.104 Test for retinacular ligament tightness. Attempt to flex the distal interphalangeal joint (DIP) with the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints in neutral.

Able to flex

DIP joint

Unable to flex

DIP joint

Figure 10.105 Testing for retinacular ligament tightness is performed by first relaxing the proximal interphalangeal joint into flexion. If you can now flex the distal interphalangeal joint, the retinacular ligaments are tight. If the proximal interphalangeal joint is flexed and you still cannot flex the distal interphalangeal joint (DIP), then there is a contracture at the distal interphalangeal joint.

against the scaphoid tubercle. Take the patient’s hand and passively glide the wrist in an ulnar-to-radial direction. The test result is positive if the patient complains of pain or if you note crepitus or an audible click. Ulnar deviation of the wrist brings the tubercle of the scaphoid out from behind the radius.

Allen’s Test

This test is used to check the patency of the radial and ulnar arteries at the level of the wrist (Figure 10.107). The patient is first asked to open and close the hand firmly several times. The hand is then squeezed very tightly to prevent any further arterial flow into the hand. Place your thumb and index finger over the radial and ulnar arteries at the wrist and press firmly. Now ask the patient to open the hand while you maintain pressure over both arteries. Remove your finger from one of the arteries and watch for the hand to turn red. This indicates normal circulation of that artery. Repeat the test, releasing pressure from the other artery. Check both arteries and both hands for comparison.

Grip and Pinch Evaluation

Different types of power grips and pinches are shown in Figures 10.108 and 10.109. Observe the patient’s ability to posture the fingers and hand as illustrated.

Referred Pain Patterns

The patient may complain of wrist and hand pain and in fact have pathology in the neck, shoulder, or elbow (Figure 10.110). Any disease process affecting the sixth, seventh, or eighth cervical nerves or the first thoracic nerve will affect the function of the hand. Damage to the brachial plexus or peripheral nerves higher up in the arm will also affect hand function. Shoulder or elbow joint pathology may also refer pain to the hand.

Radiological Views

Radiological views of the hand and wrist are shown in Figures 10.111 and 10.112.

U = Ulna

R = Radius N = Navicular C = Carpals

M = Metacarpals P = Phalanges W = Wrist joint

CMC = First carpometacarpal joint

Functional Anatomy

The hip is a large, deep ball-and-socket articulation. As such, it is quite stable, while permitting a significant range of motion. To achieve stability, the hip relies on a combination of ligamentous and articular (i.e., acetabular, labrum) structures. The primary ligaments of the hips are the capsular Y ligament and the intraarticular ligamentum teres. Aside from the modest vascular supply to the femoral head the ligamentum provides, the ligamentum teres provides relatively little stability to the hip joint. The capsular Y ligament is, on the other hand, a significant stabilizer for the hip joint. It is important for its ability to shorten and tighten with extension and internal rotation, a fact found to be useful in the reduction of certain fractures. Since the hip is offset laterally from the midline of the body, unassisted it provides little stability to the torso during unilateral stance. During gait, the body’s center of gravity is normally medial to the supporting limb. As such, ligamentous structures of the hip are insufficient to stabilize the body during the unilateral support phase of gait. For stability during gait, the body is critically dependent upon the muscles proximal to the hip joint.

The muscles providing medial–lateral stability are the glutei (minimus, medius, and maximus) and the iliotibial band (with the tensor fasciae latae). These muscles and tissues lie lateral to the hip joint. In general, the hip can be visualized as a fulcrum on which the pelvis and torso are supported (Figure 11.1). The medial aspect of the fulcrum experiences the downward force of the body’s weight (merging at a point in space 1 cm anterior to the first sacral segment in the midline of the body). The other side of the fulcrum is counterbalanced by the muscular contraction effort of

A

Bodyweight

Fulcrum

Knee

Figure 11.1 (A) The classic Koch model depicts the hip as a fulcrum of uneven lengths. Stability against the inward rotation of the pelvis during unilateral stance is provided dynamically by the abductor musculature (gluteus medius, gluteus minimus).

(B) During unilateral support, the body’s center of gravity creates a compression and varus moment deforming force at the hip, knee and ankle of the supporting limb.

The Hip Chapter 11

the abductor muscles. The ratio of the relative lengths over which these two opposing forces work is 2 : 1, respectively. Hence, the glutei must be capable of exerting two times the body weight of contractile effort during unilateral stance in order to maintain the pelvis at equilibrium. A corollary of this is that during unilateral support, the hip will experience a total of three times body weight of compressive load (body weight + [2 × body weight] muscular contractile force across the hip joint). This is a sixfold increase over the force experienced by the hip during bilateral stance.

The glutei are supplemented by the iliotibial band, which is a broad fibrous sheath extending from the iliac crest of the pelvis to its attachment at the distal end of the femur and on across to the anterolateral aspect of the knee joint. As such, it functions as a tension band and has the important task of converting what

Iliotibial band

Figure 11.2 A more complete model of hip mechanics includes the iliotibial band. This inelastic structure extends from the lateral iliac crest to the distal part of the femur and on across the knee joint to the tubercle of gerdy on the anterolateral aspect of the tibia. As such, the iliotibial band acts as a static stabilizer of the hip during the unilateral stance phase of gait. As a tension band, it protects the femur from excessive medial bending deformation. It therefore converts what would otherwise be potentially damaging tension loads on the lateral femur into well-tolerated compression stresses.

Bodyweight

Hip joint

Pelvis

ITB

Femur

Figure 11.3 This is a mechanical model of the situation depicted in Figure 11.2.

would otherwise be a potentially unsustainable tensile load into a moderate and well-tolerated compression load along the lateral femoral cortex (Figures 11.2 and 11.3). The importance of these soft-tissue structures for proper hip function can be greatly appreciated when they are compromised by either pain, injury, or neurological impairment. The result will be a severely compromised and dysfunctional pattern of gait. The most dramatic demonstration of the importance of the iliotibial band soft tissues as stabilizers of the hip can be seen when one compares the functional capacities of subjects who have had a below-knee amputation with those of subjects who have had an above-knee amputation. The below-knee amputee, with the benefit of modern technology, can function with as little as 10% energy inefficiency as compared to a normal, intact individual. In fact, it is possible for a below-knee amputee with a properly fitted prosthesis to run 100 m in 11 seconds. The below-knee amputee also is able to easily sustain unilateral stance on the amputated extremity. The above-knee amputee, however, experiences at least 40% energy deficiency in function as compared to normal individuals. The above-knee amputee is also unable to stand unilaterally on the amputated limb without leaning toward the affected side. This inability to stand erect without listing is termed a positive Trendelenburg sign. In the amputee, this is directly due to the loss of the static stabilizing function of the iliotibial band due to compromise of the iliotibial band insertion with above-knee amputation. The loss of the static stabilizing effect of