In de literatuur zijn al diverse studies gedaan. Het huisartsengenootschap heeft een gedegen samenvatting gemaakt van de bestaande onderzoeksliteratuur. kijk hiervoor op NHG-standaard

Als u bij een therapeut, huisarts of specialist komt kan het klinisch onderzoek van uw tennisarm soms worden uitgebreid met ultrasound-onderzoek, een MRI, röntgenfoto of CT-scan. Indien er aantoonbare pathologie kan worden aangetoond van het peesweefsel moet u er rekening mee houden dat deze afwijkingen niet per se uw tennisarmklachten verklaren. Vaak worden deze afwijkingen ook gezien aan de andere elleboog waar u geen klachten heeft. Aanvullende onderzoeken zoals deze kunnen hoogstens iets zeggen over het stadium waarin de pathologie zich mogelijk bevindt en deze onderzoeken kunnen waardevol zijn om andere pathologie van de elleboog uit te sluiten. De diagnose tenniselleboog kan betrouwbaar gesteld worden middels bewegingstesten waardoor aanvullende onderzoeken niet nodig zijn. Uit wetenschappelijk onderzoek blijkt dat er zelden een relatie gevonden wordt tussen wat men ziet en de mogelijke symptomen die men ervaart. Een diagnose puur gebaseerd op beelden (imaging) moet niet altijd als betrouwbaar worden aangemerkt. Bewegingsonderzoek en anamnese zijn daarnaast van groot belang.

Bij het bewegingsonderzoek van de tenniselleboog is nauwelijks onderscheidt te maken tussen de diverse spieren die de klachten zouden kunnen verklaren. Er is een gemeenschappelijke peesaanhechting en elke aanspanning van een polsstrekker heeft direct gevolgen voor de andere strekkers. Onderscheid is door palpatie of bewegingsonderzoek niet te maken en zeker niet betrouwbaar. Fysiotherapeuten hebben de neiging om peesletsels van de tennisarm in te delen in type 1 t/m 4. Deze differentiaal diagnose is ook niet betrouwbaar en heeft geen enkel belang bij een mogelijke behandeling. Pathologie van een tennisarm is alleen te vinden in zone van pees-bot-overgang. De plaats van de pijn is niet altijd de plaats van de pathologie.

The elbow complex is made  up of three separate articulations, the humero-ulnar joint, the humeroradial  (radiocapitellar) joint, and the superior radio-ulnar joint. These joints are  covered by the same capsule. The elbow allows flexion and extension, as well  as pronation and supination, and thus enables the hand to be placed in a  variety of positions in space. Elbow flexion brings the hand to the chest, the  mouth, or the face, thereby allowing the performance of most of the activities  associated with feeding, dressing,
and body care; elbow extension, on the  other hand, takes the hand away from the body, and enables it to grasp  objects.Elbow injuries are rare; however, they may be difficult to diagnose. This  problem may be resolved to some extent or simplified by a full and systematic  clinical examination. The joint is superficial, and hence readily accessible  to clinical examination. As with other structures in the body, the examiner  must be thoroughly familiar with the anatomy of the joint and with the  abnormal
conditions that may be encountered. This article deals with the broad principles of clinical examination, and  will highlight only some of the disorders of the elbow.

ANATOMY AND  PATHOPHYSIOLOGY

ANATOMICAL STRUCTURES
The anatomy of the elbow joint and the surrounding structures has been the  subject of much research. In this article, only the main points that have  emerged from recent studies will be summarized.

The bones (Figs. 1-4 )

Figure 1 Diagrammatic AP view of elbow joint
Figure  2 Diagrammatic lateral view of elbow joint.
Note that the elbow is  slightly twisted in respect of the axis of the  ulna.

The trochlea is shaped like a pulley; its medial lip is more prominent than  the lateral one. The groove of the pulley runs obliquely downwards and  outwards; it courses in a helical manner, forming an arch of about 330°. The  distal joint surface of the humerus is in about 30° anterior rotation with  respect to the long axis of the humerus, in the sagittal plane; the condyles  have 3-8° of internal rotation with respect to a line joining the epicondyles,  in the axial plane; while, in the frontal plane there is a 6-8° valgus tilt of  the condyles with respect to the long axis of the humerus (32, 34, 42). Elbow rotation is virtually around a single  centre, which coincides with the condylotrochlear axis (48). On a true lateral radiograph of the elbow, the  flexion-extension axis is at the centre of three concentric circles formed,  respectively, by the projection of the edges of the condyles, the ulnar groove  at the back of the medial epicondyle, and the medial lip of the trochlea (Fig.  4b). This flexion-extension axis is on a vertical line drawn down from the  anterior cortex of the humeral shaft. It is an essential landmark for the  implantation of a total elbow joint replacement

 

Figure 3 AP radiograph of the elbow

Figure 4a: Radiograph of the elbow taken at right angles  to the axis of the forearm.
Note medial rotation of the humerus, as  shown in the diagram in Figure 2.

Figure 4b: True lateral radiograph of the humerus.
The  centres of the three circles formed by the edge of the condyle, the  ulnar groove, and the medial lip of the trochlea coincide; this point is  the flexion-extension axis of the elbow.The axis is on a vertical line  drawn down from the anterior cortex of the humeral  shaft. There is a valgus angle of about 4° between the trochlear (greater sigmoid)  notch of the ulna and the ulnar shaft (32,  34). The opening of the trochlear notch is angled ca. 30° posteriorly  with respect to the long axis of the ulna; this allows better approximation in  flexion to the 30° anterior rotation of the humeral articular condyles (34). The joint surface of the trochlear notch forms an arc of about 180°; however, it is not entirely covered with  cartilage: in over 90% of individuals, a bare area covered by fibro-adipose  tissue extends transversely across the mid-portion of the trochlear notch;  this feature accounts for the frequency of fractures at this site, and permits  a trans-olecranon approach to the joint (34). The radial head is covered with cartilage over four fifths of its  circumference. The 15° angulation between the neck and the shaft of the radius  leaves an excursion of 180° for forearm rotation (34).

The joint capsule
The capsule is attached around the articular surfaces, and blends with the  annular ligament. It covers the tip of the olecranon, the coronoid process,  and the radial fossa. The fibres are arranged in such a way as to provide  stabilization in flexion and in full extension (23). When the elbow is stiff, the capsular capacity will be  reduced by more than 50%; equally, the capsular compliance of the stiff elbow  will be very poor, which shows that the capsule itself has been  compromised (14). The position of minimum intracapsular pressure (“resting position”) is around 60-70° of flexion, which  means that prolonged immobilization of the elbow in this position – as  practised since the days of Ambroise Paré – will increase the risk of capsular  contraction (14).

The ligaments
The medial collateral ligament is a strong and well-demarcated structure  that consists of three bundles Fig. 5):

Figure 5 Diagrammatic view  of the medial collateral ligament, with its three bundles. The anterior  bundle is the most important functionally, since it provides valgus and  anteroposterior stability.
Figure  6 Diagrammatic view of the lateral ligament complex. It would appear  that the most import structure is the lateral collateral ligament, which  blends with the annular ligament. The lateral ulnar collateral ligament  is indissociable from the lateral collateral ligament, at its attachment  to the lateral epicondyle. Distally, it branches off, and attaches to  the supinator crest. The role of the accessory lateral collateral  ligament is poorly understood.
Figure 7 Diagrammatic view of the origin and insertion of anconeus, which covers  the capsule and collateral ligaments on the lateral side.

The oblique anterior bundle is wide (5 mm) and thick. Its apex is  attached to the front and the medial aspect of the medial epicondyle, of  which it covers two thirds, and its base to the medial aspect of the  ulna, just below the coronoid process(9,  32). This bundle is taut in flexion and in extension; its mean  length is 27 mm(31, 32).

The oblique posterior bundle is less well defined. This broader  structure is also attached low on the medial epicondyle, and inserts in  a fan-shaped pattern over virtually the entire margin of the trochlear  notch of the olecranon. It is one of the structures that make up the  cubital tunnel floor(9). This bundle  is taut in flexion only; it is absent in many primates, which suggests  that it is not a main stabilizer of the elbow(31, 53). The two bundles of the medial collateral  ligament insert slightly posterior to the centre of rotation, which  accounts for the fact that they are tauter in flexion than in  extension(23).

The oblique transverse ligament (sometimes referred to as the  ligament of Cooper) is short, and does not appear to have a stabilizing  role(31, 32). It extends from the  posterosuperior portion of the trochlear notch to the coronoid process;  its origin blends together with that of the anterior bundle(9). Like the posterior bundle, it  contributes to the floor of the cubital tunnel. On the lateral side, there is no discrete collateral ligament in the strict  sense of the term. Anatomical patterns vary widely, which is why the  description of the structures involved has been difficult, and why disorders  of the lateral collateral complex may be hard to understand (31, 32, 42, 43). There are five ligamentous structures  involved in the lateral stabilization of the elbow joint (Figs. 6, 7):

The lateral (radial) collateral ligament attaches to the medial  aspect of the lateral epicondyle and inserts into the annular  ligament(31). Its origin overlies the  centre of rotation of the elbow, which means that the ligament will be  taut throughout flexion and extension(23,  32). Its mean length is 21 mm(31). The fan-shaped base of the ligament blends with the  fibres of the annular ligament(43).

The annular ligament is a thick structure that attaches to the  anterior and posterior margin of the radial (lesser sigmoid) notch. It  makes up four fifths of the fibro-osseous ring that encircles the head  of the radius(32).

The lateral ulnar collateral ligament is difficult to distinguish as  a discrete structure. It attaches to the lateral epicondyle, like the  lateral collateral ligament, with which it blends at this site; it  inserts into the superficial and posterior fibres of the annular  ligament, but attaches to the supinator crest of the ulna(31, 42, 43). It forms, roughly, the  posterior part of the lateral collateral ligament complex.

The accessory lateral collateral ligament has its origin in the  distal fibres of the annular ligament, and attaches distal to the  attachment of the lateral ulnar collateral ligament. It is an inconstant  structure. Since it is taut only with varus stress, it may act as a  stabilizer of the annular ligament when a varus stress is imposed upon  the joint(32, 42).

The anconeus muscle, whose physiological role is still the subject of  controversy, appears to be chiefly a joint stabilizer, serving as an  active collateral ligament(7, 53).  This would account for the fact that it is often torn when the lateral  collateral ligament complex is ruptured as a result of elbow  dislocation.

BIOMECHANICAL IMPLICATIONS
About 60% of the axial loads imposed on the elbow will be transmitted  through the humeroradial joint, as compared with only 40% through The  humero-ulnar articulation (34). The stresses  imposed on the elbow vary; they depend on the load applied, the resultant force vector, and the length of the lever arm. The loads may amount to 2-3  times the body weight, and to 8-10 times the lifted weight. This accounts for  the compressive loads observed during simple activities such as dressing or  feeding (48, 51). The use of crutches will  transfer between 40% and 50% of the body weight onto the upper limb (51). The elbow is a very congruous joint, and, hence, inherently very stable. In  flexion, the coronoid process locks into the coronoid fossa, while the medial  rim of the radial head engages in the trochleocapitellar groove
(23). In extension, the apex of the olecranon is  held in the olecranon fossa. Elbow stability is enhanced by the perfect  congruency between the radial head and the radial notch of the ulna. Roughly  speaking, the bony surfaces contribute 50% of the mediolateral stability of  the elbow, while the other 50% comes from the ligaments (34). One important thing to bear in mind is that the role of  each of these structures varies with the degree of flexion or extension of the  elbow. Seventy-eight per cent of the valgus stability of the elbow is contributed  by the medial collateral ligament; the bony surfaces, including the  humeroradial joint, have only an accessory function in the constraint to  valgus stress of the elbow, although experimental studies have not as yet  provided unequivocal evidence (19, 29, 33, 42,  48). In experiments, the insertion of a Silastic implant was seen to leave valgus stability unaltered (19). By  and large, valgus stability comes from the bony structures below 20° and above  120° of flexion, and from the anterior bundle of the medial collateral  ligament over the in-between range (11). The  flexor-pronator group is bulky, but does not appear to provide dynamic support  of the medial aspect of the elbow
(16). The  radial head has only a secondary role, providing about 30% of the stability on  the lateral side
(19, 23, 33). The minor  importance of the radial head as a lateral stabilizer is illustrated by the  fact that radial head excision will not adversely affect the joint, providing  that the medial collateral ligament is intact. However, a distinction must be  made between elbow valgus stress, which is checked by the medial collateral  ligament, and external rotation (or supination) stress, which is checked by  the lateral collateral ligament (43). There is much less agreement concerning the roles of the different  ligamentous structures in varus stability. Initially, it was thought that the  annular ligament was chiefly responsible for resistance to varus stress  between 40° and 60° of elbow flexion (49).  According to this author, the lateral collateral ligament serves to stabilize  the annular ligament. This idea was contested by several authors (48), which prompted Søjbjerg et al. to  reinvestigate this subject. They showed that the isolated division of the  lateral collateral ligament resulted in 15° of varus (at 110° of flexion), and  that the division of the lateral ulnar collateral ligament had little  influence on the instability observed (43).  Thus, it is the lateral collateral ligament complex, and in particular the  lateral collateral ligament, that stabilizes to varus and extension loads (34, 43, 49). The sole function of the annular  ligament appears to be the stabilization of the radio-ulnar joint. The anterior joint capsule resists distraction, and, under those  conditions, provides 85% of the resistance observed (33). In the sagittal plane, stability also depends on the medial collateral  ligament
(33). Loss of less than 50% of the  olecranon will not interfere with function, providing that the collaterals are  intact (4). Valgus stability is provided  largely by the proximal portion of the trochlear notch of the ulna (85%),  while varus stability is chiefly a function of the distal part of this notch  (65%) (4, 23). In the sagittal plane, bony  stability in extension comes from the coronoid process (23, 47). This bony and  igamentous stability is enhanced, in  the sagittal plane, by the powerful action of the muscles around the elbow.

CLINICAL  EXAMINATION
HISTORY
In addition to the standard orthopaedic history, the following items of  information should be obtained from patients presenting with elbow  dysfunction: age, duration of the complaint, or time since onset of the  elbow-related symptoms. The dominant side needs to be ascertained;  specifically, it must be established whether there has been a recent reversal  of the natural dominance, which would show
that function has been severely  impaired. The severity of the patient s pain is assessed using a visual analogue  scale. The site of the pain may provide valuable clues. Conditions involving  the lateral compartment (radiocapitellar joint) provoke pain that extends over  the lateral aspect of the elbow, with radiation proximally to the midhumerus  and distally over the forearm; this pain may be deep. Diffuse pathological  conditions, on the other hand, cause pain that is described as periarticular  in distribution(55) The patient should be questioned about locking, pain and/or instability  during throwing movements, joint swelling, or fleeting inability to extend the  elbow, which would suggest a joint effusion.
Paraesthesiae of the hand may, in some cases, be related to ulnar nerve  compromise at the level of the elbow. A note should also be made of any previous treatments of the elbow  (synoviorthesis, intra-articular injections, surgery).

INSPECTION
Since the elbow is a superficial joint, many of its disorders can be  readily detected by simple inspection. The patient should be suitably undressed to the waist for examination. Since, at the front, the muscle masses  obscure the joint, much of the examination will need to be conducted with the  examiner sitting or standing behind the patient. The patient should be  standing, with shoulders slightly braced back, to display the elbow. When the forearm is in full extension and supination, there will be a  physiological valgus (“carrying angle”) of 9-14°; in women, the angle will be  2-3° greater (8, 18, 35, 55). This angle  has been found to be 10-15° greater in the dominant arm of throwing athletes (5). This angle allows the elbow to be  tucked into the waist depression above the iliac crest; it increases when a  heavy object is being
lifted (Fig. 8). Any increase in, or loss of, this  physiological angle is indicative either of major elbow instability or of  malunion. However, the angle varies from valgus in extension to varus in  flexion, and its measurement is not of any practical importance(48).

Figure 8 The physiological  valgus ( carrying angle ) of the elbow is increased when a load is being  carried. Normally, the angle is between 9 and 14° when the elbow is  extended and the forearm is  supinated.
Sometimes, on the side of the elbow, bulging in the para-olecranon groove  will be seen; such a swelling is produced by an effusion or by synovial tissue  proliferation
(55). On the back, prominence  of the olecranon is a sign of posterior subluxation of the elbow, a feature  commonly found in RA (55).

Rheumatoid nodules are extremely common; they are usually found on the  posterior aspect of the elbow, mainly on the medial aspect of the extensor  surface. The nodules should be counted and their volume noted: large nodules  may cause skin ulceration and harbour infection. A note should also be made of  their site, since they may cause problems if they are over an intended  surgical approach to the elbow. Bursitis is also a frequently encountered pathology, especially in RA  patients. As with nodules, the volume of the lesion and the quality of the  overlying skin should be noted Inspection may also show skin atrophy at steroid injection sites, or scars  from previous surgery. These features must be noted, since they may affect the  surgical approach to be employed.

PALPATION
Palpation starts at the posterior aspect, with the patient standing with  his or her shoulder braced backwards. The three palpation landmarks – the two  epicondyles and the apex of the olecranon – form an equilateral triangle when  the elbow is flexed 90°, and a straight line when the elbow is in extension  (Figs. 9, 10).

Figures 9, 10 Three bony landmarks – the medial  epicondyle, the lateral epicondyle, and the apex of the olecranon – form  an equilateral triangle when the elbow is flexed 90°, and a straight  line when the elbow is in extension Since the elbow is a very superficial joint, it can be readily palpated  from behind and from the sides. The posterior aspect has the olecranon mid-way  between the medial and the lateral condyle. Slight elbow flexion will bring  the olecranon out of the olecranon fossa, in which it lodges in extension; in  this position, the proximal portion of the fossa on either side of the triceps  tendon may be palpated
(Fig. 11).

Figure 11 Flexing the elbow allows palpation of the  olecranon fossa on either side of the triceps tendon.
Figure 12 Anatomical landmarks on the lateral aspect of  the elbow: The lateral epicondyle continues proximally in the  supracondylar ridge. Two centimetres distally, the main landmark is  formed by the radial head. The olecranon bursa is not in communication with the synovial cavity. This  is why the elbow may be mobilized in bursitis, and why even massive bursitis  will not be tender. In chronic bursitis, a boggy globular mass may be  palpated; the overlying skin will be thickened. Flat, hard nodules may be felt  under the palpating fingertips (12). In  infected bursitis, the skin will be tight and shiny; streaks of lymphangitis  will be commonly seen; while in 25% of the cases, the axillary lymph nodes  will be enlarged
(12). On the lateral side, the main landmarks are the lateral epicondyle  proximally and the radial head distally. The supracondylar ridge is also very  accessible to palpation; its chief value is that of a landmark for surgical  approaches (Fig. 12). Sometimes, palpation may be carried out all the way up  to the deltoid tuberosity. The radial head is palpated with the examiner s  thumb, while the other hand is used to pronate and supinate the forearm (Fig.  13). The head is about 2 cm distal to the lateral epicondyle (5). Inside the triangle formed by the bony  prominences of the lateral epicondyle, the radial head and the olecranon, the  joint itself is palpated, to detect even very minor effusions or low-grade  synovitis (Fig. 14).

Figure 13 Anatomical landmarks on the lateral aspect of  the elbow: The radial head is palpated with the thumb, while the  examiner s other hand is used to pronate and supinate the forearm.

Figure 14 The elbow joint may be palpated inside a triangle  formed by the bony prominences of the lateral epicondyle, the radial  head, and the olecranon. This palpation will reveal even minor effusions  or mild synovitis. Puncture for joint aspiration is performed inside  this triangle. Similarly, an arthroscopy portal may be placed there  (posterolateral portal). The muscles on the lateral side may be palpated individually. For the  palpation of brachioradialis, the patient is asked to clench his or  her fist  and flex the elbow with the forearm in neutral position (mid-way between  pronation and supination) and with the fist blocked under a table (Fig. 15).  The wrist extensors are palpated by asking the patient to extend the forearm  at the elbow against resistance (Fig. 16). Extensor carpi radialis longus  produces both flexion and abduction of the wrist. Anconeus may be palpated  behind the radial head, on the side of the olecranon; it increases in bulk  when the forearm is extended against resistance (35).

Figure 15 Palpation and testing of brachioradialis, a  forearm flexor.
Figure 16 Palpation and testing of the wrist  extensors From the medial side, the joint is not very accessible to palpation, and  the small amount of synovial tissue on the medial border of the olecranon  makes joint palpation difficult (35).  Palpation of the ridge that provides insertion for the intermuscular septum is  useful mainly as a guide for surgical approaches. Also, the supracondylar  lymph nodes may be palpated at this site (Fig. 17). Over, and slightly  anterior to, the supracondylar ridge, a bony excrescence may be palpated; this  outgrowth may irritate the median nerve (5). This supracondylar process is present in 1-3% of the population, and is seen  at a distance of 5-7 cm above the joint line (32). Behind the septum, the ulnar nerve may be palpated; in  patients with a very mobile nerve, it may be seen to roll on the medial  condyle (10) (Fig. 18). Ulnar nerve  instability is more easily tested with the arm in slight abduction and  external rotation, with the elbow flexed between 20 and 70°.

Figure 17 Palpation of the medial aspect of the elbow.  Above the medial epicondyle is the ridge on which the intermuscular  septum inserts. Two centimetres above the epicondyle is the site used  for lymph node palpation.
Figure 18 The ulnar nerve is palpated behind the  intermuscular septum. It may sometimes sublux or roll on the epicondyle.  Ulnar nerve instability is more readily demonstrated if the elbow is  flexed 60° and the upper limb is abducted and externally  rotated. Anteriorly, the bulk of the flexor-pronator group restricts the extent of  joint palpation. The flexor-pronator muscles must be tested as a unit, by  asking the patient to perform wrist adduction and flexion against resistance  (Fig. 19). Next, each one of these muscles should be tested individually. The  anterior aspect does not lend itself to palpation, since it is tucked away  behind the muscles. Laterally, brachioradialis will be felt; and in the  middle, the biceps tendon is readily accessible if the patient is made to flex the forearm against resistance. Lacertus fibrosus is palpated medial to the  biceps tendon; the pulse of the brachial artery will be felt deep to this  aponeurosis (Fig. 20). Sometimes anterior protrusion cysts produced by  herniated synovial membrane may be felt (52).

Figure 20 Palpation of the  medial biceps expansion (lacertus fibrosus), which courses over the  brachial vessels and the median nerve.
Figure 19 Diagrammatic view  of the pattern of the flexor-pronator group: The thumb represents  pronator teres; the index, flexor carpi radialis; the middle finger,  palmaris longus; and the ring finger, flexor carpi  ulnaris.

MOBILITY
The main function of the elbow is to bring the hand to the mouth; this is  why the investigation of the elbow range of movement (ROM) is an important  part of the examination process. Any difference between passive and active  mobility is usually due to reflex inhibition from pain (55). The end-feel – the feeling transmitted to the examiner s  hands at the extreme range of passive motion – must also be assessed

(Table  1). If the feel is abnormal, there is usually something wrong with the  joint

Bony Two hard surfaces meeting, bone to bone (elbow extension)
Capsular Leathery feel, further motion available (forearm pronation and  supination)
Soft tissue approximation Soft tissue contact (elbow flexion)
Spasm Muscle contraction limits motion
Springy block Intra-articular block; rebound is felt
Empty Movement causes pain, pain limits movement

forearm; the  measurement thus obtained will be reliable to within 5° of accuracyBony Two hard surfaces meeting, bone to bone (elbow extension) Capsular Leathery feel, further motion available (forearm  ronation and  supination) Soft tissue approximation Soft tissue contact (elbow flexion) Spasm Muscle contraction limits motion Springy block Intra-articular block; rebound is felt Empty Movement causes pain, pain limits movement Table 1 Classification and description of end-feels (modified from TS Ellenbecker  & AJ Mattalino)(12a) Flexion-extension The normal flexion-extension range is 0 to 140° (
+ 10°). Mobility is  measured with a goniometer placed on the side of the arm and (35) (Fig. 21). This ROM is well in excess of  what is needed for the majority of activities of daily living (ADLs). The  useful arc of motion is between 30° and 130° of elbow flexion; most ADLs  require an arc of only 60-120
°(30, 33, 55) (Fig. 22).
Figure 21a-b Flexion-extension is measured with a goniometer applied to the lateral  aspect of the elbow. The normal range is 0-140° (+  10°).

 

 

Figure 22 Arcs of flexion required for some activities of  daily living (adapted from Morrey, 1981)
Door / Chair / Fork /  Telephone Loss of extension provides a very sensitive clue to intra-articular elbow  pathology, since extension is the first sector of the ROM to be affected, and  the last to recover
(55). However, since the  extension deficit shortens the lever arm, it is well tolerated up to a loss of  45°
(55). At the end of flexion, there will  be a soft-tissue approximation end-feel as the movement is blocked by the bulk  of the arm and forearm muscles. At the end of the normal extension movement,  there will be a bony end-feel, as the olecranon locks into the olecranon  fossa (5).

Pronation and supination
Pronation and supination cannot be complete unless the proximal and distal  radio-ulnar joints are in correct anatomical relationship, the two bones are  of normal length relative to each other, and the interosseous membrane is  intact (55). The arc of motion varies widely  in different individuals; the mean values are 70° pronation, and 85°  supination (Figs. 23, 24). However, with only 50° pronation as well as  supination, most ADLs can be readily performed (30,  55). At the end of pronation and supination, there will be a capsular  end-feel (5).

Figure 23 Measuring pronation: The vertical limb of the  goniometer is placed parallel to the long axis of the humerus, while the  horizontal limb is placed on the back of the wrist (to eliminate  additional motion at the radiocarpal joint). The mean value is  70°.
Figure 24 Measuring supination: The horizontal limb is  placed on the anterior aspect of the wrist. The mean value is  85°.

STABILITY
Mediolateral stability Stability testing is performed with the patient standing, shoulder braced  backwards; the examiner is behind the patient. The elbow is slightly flexed,  to bring the apex of the olecranon out of the fossa. Varus stability is  checked with the humerus in full internal rotation, while valgus stability is  tested in full external rotation (Figs. 25, 26). The physiological laxity of  the elbow between 10 and 20° of flexion, in varus and in valgus, does not  exceed 5°. In rotation (pronation and supination), it does not exceed 3° (49).

 

 

 

 

Figure 25a-b Testing mediolateral elbow  stability
25a: To eliminate interfering movements during varus  instability testing, the humerus is placed in full internal rotation and  the forearm in pronation. 25b: To eliminate interfering movements during valgus  instability testing, the humerus is placed in full external rotation.  Valgus testing is done with the forearm pronated, to test the medial  collateral ligament, followed by testing in supination, to check the  lateral collateral complex. Figure 26 Testing  mediolateral stability in an RA patient with a TEJR . 26a: Varus  instability . 26b: Valgus instability.  The physiological mediolateral instability is <  5°.
Patients may also be examined lying supine. In this case, the humerus is  held with one hand, while the examiner s other hand places the forearm in  valgus (or in varus), with the elbow flexed 20-30° (to remove the olecranon  from the fossa) (5, 39) (Fig. 27). With the  patient s abducted and externally rotated arm tucked under the examiner s  shoulder, the medial collateral ligament may be palpated at the same time (11) (Fig. 28). As we shall see in the section on  instability, it is important for mediolateral stability to be tested in pronation and in supination.

Figure 27 Assessing mediolateral stability with the  patient lying supine. The elbow should be slightly flexed, to disengage  the olecranon from the fossa. Testing must be done in pronation and in  supination.
Figure 28 With the abducted and externally rotated arm  tucked under the examiner s shoulder, the medial collateral ligament may  be palpated.

Anteroposterior stability
Anteroposterior stability is controlled exclusively by the collaterals.  Removal of the olecranon will not result in instability if the collaterals,  and above all the medial collateral ligament, are intact. In RA patients, a  search should be made for anteroposterior translation, which shows the extent  of joint destruction. The forearm is flexed to 90° and held by the examiner  with one hand, while the other hand holds the humerus, as anteroposterior  stress is applied to the joint.

NEUROLOGICAL EXAMINATION
This examination forms part of the examination of the elbow; depending on  the patient s symptoms, a rough screen or a more detailed investigation will  have to be performed.
Ulnar nerve
At the elbow, the ulnar nerve may be damaged at several different levels:  at the arcade of Struthers; in the ulnar groove behind the medial epicondyle;  under the fascial band bridging the two heads of flexor carpi ulnaris (arcade  of Osborne); and even under the deep aponeurosis of flexor carpi ulnaris
(3) (Figs. 29, 30). Tinel s sign, elicited at  different levels, will give a clue as to the site of the compression (Fig.  31).

 

 

 

 

 

 

 

 

 

Figure 29 Diagrammatic view  of the four zones around the elbow in which the ulnar nerve may be  compressed
1 – Under the deep aponeurosis of flexor carpi  ulnaris
2 – Under the fibrous arcade formed by the two heads  of flexor carpi ulnaris (arcade of Osborne). This is the most frequently  encountered entrapment site.
3 – Behind the medial  epicondyle
4 – At the arcade of Struthers

Figure 30a-b Ulnar nerve compression in an RA patient.
30a: Ulnar nerve (on loop) flattened by synovial  proliferation, and destruction of the joint.
30b: With the nerve pulled out of the way, the inflamed  synovia is seen at the bottom of the tunnel.

Figure 31
Eliciting Tinel’s sign: Paraestesiae in the territory of
the ulna nerve allow an assessment of the likely
site of compression In the ulnar groove, the ulnar nerve may be affected by synovial proliferations herniating on the medial side of the joint; by bony lesions  with spicules causing irritation along the course of the nerve behind the  epicondyle; or by ischaemic events. Paraesthesiae of the ulnar border of the  hand and the fingers are usually the first signs of ulnar neuropathy. Pain is  a less frequent complaint; where it is encountered, it is usually localized to  the elbow or along the medial edge of the forearm. These symptoms are commonly  triggered or exacerbated by attempts to flex the elbow. Prolonged elbow  flexion may produce the paraesthesiae reported by the patient. This test –  known as the elbow flexion test, and analogous to Phalen s test for carpal  tunnel syndrome – can be made more discriminating by putting the wrist  in  extension, so as not to perform a Phalen test at the same time. In the more  advanced stages, there will be ulnar nerve palsy as well.

Posterior interosseous nerve
The posterior interosseous nerve is the motor branch of the radial nerve.  It can be found, at the back of the arm, using the three-finger method  described by Henry: the index, middle, and ring fingers of the examiner s hand  opposite the examined side are placed on the posterior aspect of the radius,  with the ring finger at the junction between the neck and the head of the  radius. The nerve will then be under the tip of the index finger.

Anterior interosseous nerve.  This motor branch of median nerve origin may be compressed where it courses  between the two heads of pronator teres (17). Compression of this nerve will lead to weakness and even  paralysis of the flexor digitorum profundus muscle of the index finger and the  flexor pollicis longus muscle of the thumb. The patient will be unable to  create an OK sign (pinching the tips of the index finger and the thumb  together).

Global muscle evaluation Testing the different muscles around the elbow forms part of the standard  workup of patients with elbow complaints. Each muscle must be tested  separately. Details of the technique to be employed will be found in the  standard textbooks, such as Kendall s (22).  The global evaluation gives a picture of the extent of a nerve trunk or plexus  lesion.
Table 2 lists the actions, nerve supply, and nerve root  derivations of the different muscles.

Movement Muscles Nerve Supply Nerve Root
Brachialis Musculocutaneou s C5 C6 (C7)
Biceps brachii Musculocutaneou s C5 C6
Elbow flexion Brachioradia lis Radial C5 C6 (C7)
Pronator teres Median C6 C7
Flexor carpi ulnaris Ulnar C7 C8
Elbow Triceps Radial C6 C7 C8
extension Anconeus Radial C7 C8 (T1)
Forearm Supinator Posterior interosseous (radial) C5 C6
supination Biceps brachii Musculocutaneou s C5 C6
Forearm Pronator quadratus Anterior interosseous (median) C8 T1
pronation Pronator teres Median C6 C7
Flexor carpi radialis Median C6 C7
Wrist flexion Flexor carpi radialis Median C6 C7
Flexor carpi ulnaris Ulnar C7 C8
Extensor carpi radialis longus Radial C6 C7
Wrist extension Extensor carpi radialis brevis Posterior interosseous (radial) C7 C8
Extensor carpi ulnaris Posterior interosseous (radial) C7 C8

Table 2 Action and innervation of the muscles around the elbow

Reflexes
Testing the reflexes forms part of the neurological examination of the  elbow. The biceps reflex is a C5 function (although the muscle is supplied by  C5 and C6); the brachioradialis reflex is C6; and the triceps reflex, C7  (Figs. 32, 33, 34).

Figures 32, 33, 34 Testing  the biceps reflex (Fig. 32 – C5 root), brachioradialis reflex (Fig. 33 –  C6 root), and triceps reflex (Fig. 34 – C7  root)

FUNCTIONAL TESTING
Functional investigation of the elbow Pronator, supinator, and extensor strength is largely the same on the  dominant and the non -dominant side; this is why a comparison with the  unaffected side is the best test(13).  However, flexor strength is always greater on the dominant side. A manual  assessment of elbow strength, at 90° of flexion and with the forearm in  neutral position, may appear somewhat crude. However, this isometric  measurement is very reliable, yielding values close to the results of isotonic  measurements, which are much more difficult to perform(6). Male subjects are about twice as strong as females, and  the dominant limb is about 6% stronger than the non-dominant one(6). Extensor strength is about 60-70% of flexor  strength(6, 35, 55). Supinator strength  usually exceeds pronator strength by 15%(6, 35,  55). Strength must be assessed, especially in RA, because of the  magnitude of mechanical
stresses: a 1 kg weight at the hand produces a  reactive force, at the 90° flexed elbow, of the order of 10 kg(55). Functional investigation of the upper limb. The elbow is situated between two highly mobile joints – the shoulder and  the wrist. It can compensate only for flexion-extension deficits. As regards  flexion, the overall capability for feeding (hand to mouth), body care (hand  to face), and hair care (hand to back of head) should be examined. The  activities looked at with regard to extension are opening doors, and reaching  to grasp objects. Global functional investigation: the lower limbs – walking aids
A search must be made for coexisting conditions affecting the lower limbs.  The use of walking aids puts increased functional loads on the elbow, and may  rule out elbow joint replacement. On the other hand, a hip or knee condition  may have to be treated with surgery first, before doing elbow replacement, so  as not to jeopardize the outcome of the elbow arthroplasty.