Anatomical	Humeroradial
	Humero-ulnar
	Radio-ulnar
Aetiological	Class 1 – bone hypoplasia group with synostosis of elbow
	Class 2 – joint maldevelopment group with synostosis of elbow

Proximal radio-ulnar synostosis has also been classified on the basis of the radiological appearance. Mital ⁷ presented a two-group classification system:

• Type I – the proximal radial epiphysis and metaphysis are fused to the ulna.

• Type II – the fusion is distal to the proximal radial epiphysis and the radial head is dislocated.

This was modified by Cleary and Omer ⁸ to a four-group system:

• Type I – clinical evidence of proximal radio-ulnar fusion without radiographic evidence (syndesmosis/synchondrosis)

• Type II – osseous radio-ulnar synostosis, normal radial head

• Type III – osseous radio-ulnar synostosis, posteriorly displaced hypoplastic radial head

• Type IV – osseous radio-ulnar synostosis, anteriorly displaced radial head.

The drawbacks of the above classification systems are that they are based purely on anatomy or radiological appearance and are not useful for evaluating the prognosis or treatment outcome. They do not indicate aetiological factors, inheritance pattern or a syndromic association.

An aetiological classification of elbow synostosis was proposed by McIntyre and Benson.⁹ They divided synostosis around the elbow into two classes:

• Class I – considers synostosis of the elbow in the bone hypoplasia group, where the primary abnormality is an anomaly in bone development (ulnar or radial ray hypoplasia) in the upper limb and the synostosis is a consequence of this.

• Class II – considers it in the ‘joint maldevelopment group’, where the synostosis is the primary anomaly, with bone development being relatively normal.

All the three anatomical types can occur within each class, may be sporadic or familial and, if familial, may be inherited as an autosomal dominant or recessive trait. The class I group is associated with musculoskeletal abnormalities outside the affected limb in 25–55% of cases.¹⁰ Class II familial cases may be syndromic and associated with multiple synostosis syndrome, Pfeiffer syndrome, Apert syndrome and Antley–Bixler syndrome.

Presentation, investigations and treatment options

Another alternative that has been proposed to achieve and maintain motion is the swivel prosthesis designed by Kelikian and Doumanian.¹³ This is a stainless steel implant that is inserted into the intramedullary canal of the radius to restore motion. However, although it has been used in four cases of post-traumatic proximal radio-ulnar synostosis with good results, it has been shown to have poor results in cases of congenital radio-ulnar synostosis.¹⁴

Surgical techniques and rehabilitation

Mobilization procedure ¹¹

Kanaya described this procedure in the following four steps:

1. Separation of the synostosis

2. Shortening angulation osteotomy of the radius to prevent dislocation of radial head

3. Soft tissue reconstruction

4. Vascularized fascio-fat graft interposition.

Separation of the synostosis

This is performed through a combined anterior and posterior approach. The posterior skin incision extends from the lateral epicondyle distally and medially to the posterior crest of the ulna, exposing the anconeus. The anconeus is detached from the ulna with a periosteal sleeve. The synostosis is identified. The proximal and distal borders are delineated. The distal border is usually demarcated by interosseous recurrent vessels that are constantly found at this site. A synchondrosis is usually seen between the radial head and proximal ulna. Both the synostosis and synchondrosis are separated by using a steel burr. The direction of separation is confirmed from the preoperative CT scans. After separation of the synostosis from the ulnar border of the radius, the forearm can be placed in a neutral position. The synostosis is then widely excised after detaching the biceps tendon from its anterior aspect and the radial head is trimmed to the desired shape.

The next stage of the operation is to expose the proximal forearm through a Henry approach. The fibrous extension of the biceps tendon to the proximal ulna is then removed in order to improve forearm rotation.

Radial osteotomy

A shortening angulation osteotomy either in flexion for posterior dislocation or extension for anterior dislocation is required to stabilize the dislocated radial head. This is achieved by removing a wedge of trapezoid bone between the insertion of the supinator and the pronator. The forearm is then placed at 20–30° of supination and the radial osteotomy fixed with a plate and screws.

Soft tissue reconstruction

The radial capsule and the annular ligament are reefed and the detached biceps tendon reattached to the posterior cortex of the radius to make it a strong supinator. The anconeus muscle is pulled anteriorly and attached to the brachialis tendon.

Vascularized fascio-fat graft

A vascularized fascio-fat graft based on the profunda humeri is harvested. This graft is 5–10 mm longer and 5–10 mm wider than the space created by separation of the synostosis. The graft is placed between the separated radius and ulna in an anterior-to-posterior direction and the donor vessels anastomosed to the radial recurrent vessels. Through the anterior approach an alternative vascularized distal radial artery-based fascio-fat graft can also be used without the necessity of reanastomosis, as done in one case by the senior author.

The wounds are closed and an above-elbow cast is applied with the forearm in neutral rotation and the elbow in 90° of flexion. The cast is maintained for 4 weeks (Fig. 15.1).

Figure 15.1 Operative procedure.

Rotational osteotomy

An alternative procedure to mobilize the synostosis is a rotational osteotomy.^15,¹⁶

These have been described at two sites in the diaphysis of the radius and ulna ^17,¹⁸ or at one site in the distal diaphysis of the radius.^19,²⁰ An osteotomy at the synostosis is extremely complex, whereas an osteotomy at two sites in the diaphysis of the radius and ulna is easier, with fewer reported complications.

A single osteotomy of the radius can be performed subperiosteally distal to the synostosis. This has the advantage of a single surgical scar and avoids the need for internal fixation. This osteotomy is recommended in children between the ages of 3 and 6 years and is most commonly performed.

A single osteotomy of the distal radius is performed through a 4 cm skin incision made distally on the radiovolar aspect of the distal forearm. The diaphysis of the radius is exposed and the superficial radial nerve and the radial artery are identified and retracted ulnarward. A sharp longitudinal incision is made on the periosteum and reflected atraumatically from the radius to preserve the longitudinal continuity of the periosteum. Several drill holes are made in the transverse line to the radius using a K-wire and a transverse osteotomy is performed using a chisel (Fig. 15.2A). A meticulous periosteal repair is then performed and the distal forearm maximally supinated and immobilized in an above-elbow plaster cast (Fig. 15.2B).

Figure 15.2 (A) Subperiosteal transverse osteotomy in the radial diaphysis. (B) Above-elbow cast with forearm in maximum supination.

Outcome including literature review

Operative procedures used in the treatment of congenital radio-ulnar synostosis fall into two major groups. Group 1 procedures are designed to restore rotation and remove the synostosis, while group 2 procedures restore the forearm to a fixed functional position. Several authors have reported poor results after separation of the synostosis and interposition of fat, muscle or silicone.^11,²¹^–²³

Kanaya et al performed the mobilization procedure in seven boys (average age 8 years 2 months) who had isolated proximal radio-ulnar synostosis. All seven children had a dislocation of the radial head preoperatively. A shortening-wedge osteotomy of the radius was performed in four patients at the time of the index procedure, while in three patients the radial head was manually reduced without an osteotomy. The radial head subsequently redislocated in the latter three patients and one of them had an osteotomy 2 years and 8 months after the index procedure to reduce and maintain the radial head alignment. At follow-up the total range of forearm rotation achieved averaged 71° with average supination of 26° and average pronation of 45°. There were no cases of reankylosis at an average follow-up of 4 years 4 months.¹² The group who had a radial osteotomy in addition to the index procedure had an average arc of 83° of forearm rotation compared to the second group, who had an average arc of rotation of 40°.

Kamineni et al ²⁴ have described a new technique of restoring forearm rotation in post-traumatic proximal radio-ulnar synostosis. This involves resecting a 1 cm thick section of bone from the proximal radial shaft distal to the synostosis. They performed this surgery on seven patients and reported an improvement in forearm rotation from an average fixed pronation of 5° to an average arc of 98°.

Osteotomies to achieve a more functional forearm position are suitable for patients with marked pronation deformity. Green and Mital ¹⁶ have reported the best results with derotational osteotomies through the fusion mass. This has the advantages of achieving a better correction and rapid healing of the osteotomy owing to the good coaptation of the divided ends. In their series results were excellent in 50%, good in 33%, fair in 6% and poor in 6%. Ogino and Hikino¹ also favoured an osteotomy through the fusion mass, but recommended resection of 0.5 cm of bone at the osteotomy site in order to shorten the forearm. All the patients in their series had complete relief of symptoms.

Goldner and Lipton recommended derotation in the distal forearm to minimize circulatory problems.²⁵ The osteotomy was done in the distal radius alone for younger patients and in both the radius and ulna in older patients.

A single osteotomy technique distal to the synostosis was reported by Kashiwa et al in 1999 ¹⁹ and subsequently modified by Fujimoto et al.²⁰ This osteotomy is performed at the distal radial diaphysis. Fujimoto presented the results of this osteotomy in three patients (four forearms) with congenital radio-ulnar synostosis. Bony union was achieved in all cases. The period of immobilization in plaster varied from 6 to 9 weeks. All patients achieved good correction, with functional improvement in activities of daily living.

Bolano ²⁶ has shown good results with an osteotomy and gradual correction of the rotation using a ring fixator. This technique is useful as there is less risk to the neurovascular structures and it has the added advantage of allowing the patients to choose the most functional position of their forearm.

The ideal position to place the forearm after the osteotomy depends on several factors. If the synostosis is bilateral and both hands are in pronation, Simmons and Waters ²⁷ recommended 20° of pronation in the dominant hand and a neutral position for the non-dominant. In unilateral cases, Green and Mital¹⁶ recommended 20–25° of supination as the supinated forearm can attain some amount of functional pronation by internal rotation, flexion and abduction at the shoulder. Ogino and Hikino¹ from Japan recommend at least 70° of palmar supination, especially in the non-dominant hand, to enable the use of chopsticks by their patients. Hence the amount of angular correction is dependent on customs, dominant hand and bilaterality.

Complications

Following excision of a synostosis and mobilization of the forearm, reankylosis can occur, giving poor results ^21,²² and a risk of radial head dislocation and posterior interosseous nerve palsy.

Complications reported following derotational osteotomies include neurovascular compromise. Green and Mital reported one case of severe Volkmann’s contracture and one case of posterior interosseous nerve palsy from their series of 13 patients. Ogino and Hikino ¹ reported two posterior interosseous nerve palsies in 13 operations, both of which spontaneously recovered.

Simmons and Waters ²⁷ reported a 36% complication rate with loss of correction in three out of 21 children and an 18% incidence of vascular compromise. A decreased range of elbow movement has also been reported.

Conclusions and personal view

In our opinion surgical treatment for congenital radio-ulnar synostosis is rarely required as most children have reasonable function. When this is not the case our preference, based on the literature and our personal experience, is to perform derotational osteotomies. These have a lower morbidity and are technically easier to perform than the mobilization procedure.

If surgery is contemplated it is mandatory for the child to be assessed preoperatively by an occupational therapist in order that a functional evaluation can be performed and the best position of the forearm determined.

Clinical Pearl 15.1

Congenital elbow synostosis is usually an isolated entity, but can be associated with more generalized upper limb deficiency or as part of a syndrome that needs further investigations.

Osteotomy remains the mainstay of treatment for humeroradial synostosis, whereas humero-ulnar synostosis is functional, requiring no treatment. Congenital radio-ulnar synostosis rarely requires treatment. Derotational osteotomy to a functional position is technically easier and has lower morbidity.

Arthrogryposis affecting the elbow

Introduction

Arthrogryposis is a syndrome of unknown cause and should be considered as a symptom complex rather than a disease. This term is used to describe a variety of conditions that have a common aetiological factor of diminished fetal movements with congenital joint stiffness and varying degrees of muscle weakness.

The disorder was first described in 1841 by Otto ²⁸ and was later called multiple congenital contractures by Schanz. The term arthrogryposis was coined by Rosencranz²⁹ and Stern in 1923 proposed the term arthrogryposis multiplex congenita,³⁰ which is the current name for this condition.

The incidence of arthrogryposis is one in 3000 live births. It includes the syndromes classical arthrogryposis or amyoplasia and distal arthrogryposis, characterized by restricted motion of the distal joints of the hands and feet and sometimes the knees.

As it presents a variable clinical picture, classical arthrogryposis or amyoplasia has been defined by criteria proposed by Goldberg which include:

1. a characteristic tubular limb posture with absent flexion creases, adducted and internally rotated shoulders, usually extended elbows, flexed and ulnarly deviated wrists, tapered and flexed fingers, hyperflexed hips, knees fixed in flexion or hyperextension and club feet

2. typical face, which is not dysmorphic

3. normal intelligence and an absence of visceral abnormalities

4. a negative family history.

Background and aetiology

The typical pathological features of arthrogryposis – thin, atrophic extremities without skin creases and fibrosis of joints with fatty accumulations about the joints – can be explained by fetal akinesia, which may result from maternal or fetal abnormalities. There is a direct correlation between the duration of akinesia and the severity of contractures at birth.³¹ The cause of fetal akinesia may be neurological or muscle abnormalities. Hence two pathological forms of arthrogryposis have been identified, namely a neuropathic form and a myopathic form. The neuropathic form is more common, accounting for over 90% of all cases, and is caused by failure of development of the anterior horn cells at the spinal level. The myopathic form is caused by defective myogenic regulatory genes,³² resulting in defective somites and absent myocytes that are replaced by adipose cells.

Classification

Arthrogryposis can be classified into three groups:

• Group 1 – predominant limb involvement, e.g. classical arthrogryposis or amyoplasia

• Group 2 – involvement of limbs with other body parts, e.g. multiple pterygium syndrome, Escobar syndrome, Freeman–Sheldon syndrome

• Group 3 – central nervous system dysfunction with limb involvement, e.g. cerebro-oculo-facio-skeletal syndrome, restrictive dermopathy.

Pathology

The common pathology in all cases of arthrogryposis is a congenital or acquired defect in the motor unit (anterior horn cells, roots, peripheral nerve, motor endplates or muscle), resulting in weakness early enough in fetal life to immobilize joints at various stages in their development.

With the exception of the feet, stiffness in arthrogryposis is due to extra-articular factors and the joint articulation is normal at birth. The muscle may be of normal size and colour or may be small, pale and contracted or completely absent, e.g. biceps and brachialis may be absent at the elbow. The ligaments and capsules of affected joints are always found to be contracted.

Genetics

Arthrogryposis shows several genetic patterns. Most cases of the amyoplasia type are sporadic; however, autosomal dominant, autosomal recessive and X-linked recessive inheritance ³³ have all been noted in arthrogryposis.

Presentation, investigation and treatment options

In arthrogryposis the upper limb is involved in 60–70% of cases. Classic arthrogryposis or amyoplasia presents most frequently with the upper limb in the ‘waiter’s tip’ posture. The elbow at birth is contracted in extension, the shoulder girdle has loss of muscle mass, especially the deltoid, and the arm is internally rotated and forearm pronated. The wrist is often in palmar flexion and ulnar deviation and the fingers are in flexion. The thumb is adducted and flexed in the palm. There are incomplete syndactylies in all web spaces and there may be camptodactyly or symphalangism of the proximal interphalangeal joints. Involvement is usually bilateral. There is limitation of both active and passive movements in all joints. Flexion is usually preserved in the shoulder.

The elbow joint is the key for rehabilitation of the upper extremity.

The elbow in arthrogryposis is either stiff in flexion or stiff in extension. Elbows that are stiff in flexion have a biceps that is stronger than the triceps. They usually have good function and do not require treatment. On the other hand, elbows that are stiff in extension have weak or absent flexor compartment muscles. The elbows show a huge discrepancy in passive and active movement, with passive flexion of up to 90° being common. Movement is markedly reduced in the wrist and fingers.

Treatment options

The management goals of arthrogryposis are directed towards support, alignment and balance of the musculoskeletal system, with the emphasis lying on repositioning the extremities together with preserving and improving joint motion. The ultimate aim of management is to allow the patient to have independence in the activities of daily living, especially with regard to feeding and personal hygiene.

The order of priorities includes:

1. achieving passive elbow flexion

2. correcting humeral rotation

3. repositioning the wrist and correcting the thumb in palm deformity.

Elbows commonly have an extension contracture with a variable amount of passive flexion and some retained active triceps function. The flexor muscles, namely biceps and brachialis, are absent or atrophic.

Upper limb treatment should be initiated only after assessing lower limb function. Elbow stability in extension should not be compromised, especially in patients who use crutches.

Non-operative management

Repetitive gentle passive manipulation improves the passive range of motion. For elbows fixed in extension, treatment should be started soon after birth. The elbow should be carefully bent several times a day and a thermoplastic splint worn at night and nap-time, keeping the arm in a bent position.

Palmer et al ³⁴ recommended stretching and serial splinting from the age of 3 months. They reported an improvement of 38% for elbow mobility and 43% for wrist mobility in their group of 63 patients who had treatment at an age younger than 18 months. Corrective splints and serial casts have been used with variable success.

The goal of physiotherapy is to achieve 90° of passive flexion by 2 years. Aggressive physiotherapy, however, should be avoided as it can cause fractures and dislocations. If physical therapy fails to restore elbow flexion, then several surgical procedures are available to improve elbow flexion and these should be performed at an early age, especially if the child is not dependent on crutches.

The surgical procedures include:

a those that achieve passive elbow flexion

Posterior release with tricepsplasty

b those that achieve active elbow flexion.

Active elbow flexion usually fails to develop as most children lack biceps and brachialis and therefore they require tendon transfers. The principles of tendon transfer state that the muscle transferred should be expendable, appropriately aligned, strong and synergistic with the weaker muscle. Unfortunately these criteria may not be fulfilled in arthrogryposis. It may also be difficult to assess the suitability of a muscle for transfer preoperatively and this decision may have to be done during surgery after exposing the muscles and evaluating their bulk, colour and contractility.

Muscles available for elbow flexorplasty procedures include the pectoralis major, latissimus dorsi, triceps, gracilis and sternomastoid muscles.

Surgical technique and rehabilitation

Posterior release with tricepsplasty

The patient is placed in the lateral or prone position. A midline incision is made in the posterior aspect of the elbow, beginning in the middle half, extending distally and to a point lateral to the olecranon. The incision is extended down to the forearm over the subcutaneous surface of the ulnar shaft for a distance of 4–5 cm. Skin flaps are mobilized by dividing the subcutaneous tissues. The ulnar nerve is identified and protected and subsequently transposed anteriorly by dividing the medial intermuscular septum. The triceps muscle is then elevated from its insertion with a long tail of periosteum. The triceps is further mobilized proximally as far as its nerve supply will permit. The distal part of the detached triceps is tubularized by suturing the muscle to itself. Then another curvilinear incision is made in the antecubital fossa and the interval between brachioradialis and pronator teres is developed. The tubularized triceps tendon is passed anteriorly subcutaneously with a tendon passer superficial to radial nerve.

Then, with the elbow at 90° of flexion and the forearm in supination, the triceps tendon is anchored to the radial tuberosity. Alternatively it can also be sutured to the biceps tendon. The wound is closed and the elbow immobilized in plaster at 90° of flexion and with the forearm in supination for 3–4 weeks. Active elbow flexion and passive range of motion exercises are then started. A resting splint is used for a further 3 weeks.

Elbow flexorplasty procedures

Bipolar pectoralis major transfer

The entire pectoralis major is mobilized on its neurovascular pedicle. It is completely detached, rotated on its two neurovascular pedicles and reattached to the coracoid or the acromion, which serves as the new origin of the muscle. Its broad fascia of origin is then reattached to the biceps tendon or the ulna to provide a new insertion for the muscle.

Operative technique and postoperative management

Surgical anatomy of pectoralis major

The pectoralis major has two parts, namely the sternocostal and the clavicular part. The former is innervated by the lateral pectoral nerves and the latter by the medial pectoral nerve. The length of the sternocostal part and the muscle power are comparable to that of the biceps. The segmental anatomy and neurovascular supply of this muscle make it suitable for segmental splitting.³⁵^–³⁷

The pectoralis major muscle may also be used as a monopolar transfer. Additional length of the muscle can be gained by elevating a segment of the rectus abdominis sheath. The origin may be located at the coracoid process or at the acromion in bipolar fashion. The insertion is at the distal biceps tendon.

Patient position

The patient is positioned supine with a support under the ipsilateral blade of the scapula. The upper limb is draped in order to allow movement of the shoulder and elbow.

Incision

A long curvilinear incision is used starting at the 7th sternocostal joint and extending vertically and proximally to a point 2 inches below the clavicle and then curving upwards and laterally towards the coracoid process. The incision is extended downwards along the anteromedial aspect of the arm to the level of the axilla, with the forearm held in the neutral position. The fascia overlying the entire pectoralis major muscle is raised as a broad inferior-based flap to the nipple line. The deltopectoral groove is identified and the clavipectoral fascia with the shoulder joint capsule is exposed by retracting the deltoid and cephalic vein laterally. Thus the entire pectoralis major is exposed. The biceps tendon at the elbow is exposed through a curvilinear incision over the antecubital fossa, dividing the bicipital aponeurosis and lacertus fibrosis. The pectoralis major muscle is then detached from its origin along the medial half of the clavicle and sternocostal border, and elevated from the pectoralis minor with a wide strip of anterior rectus abdominis fascia, taking care to preserve its neurovascular pedicle.

The humeral insertion of the muscle is detached and the muscle rotated 90° on its neurovascular pedicles. The origins of the clavicular and sternocostal heads, together with the attached anterior rectus abdominis sheath, are rolled into a tube and directed down the arm through an anterior subcutaneous tunnel exiting through the second incision. The rectus fascial tube is sutured to the biceps tendon using a Pulvertaft weave and non-absorbable sutures.

The humeral attachment of the muscle is now directed cephalad and sutured securely to the anterior aspect of the acromion and the lateral end of the clavicle with suture anchors. As this is performed the muscle is placed under appropriate tension with the elbow flexed to 100°. For effective function it is important that the transferred pectoralis major is collinear to the biceps muscle.

Unipolar pectoralis major transfer (Clark procedure)

This is not recommended as it allows active elbow flexion only with the shoulder in abduction. With the shoulder adducted the line of muscle pull results in further adduction and can produce an adduction contracture of the arm.

Bipolar latissimus dorsi transfer

Latissimus dorsi is a good choice for an elbow flexorplasty because of its long neurovascular pedicle and because it can be shaped into a contractile cylindrical motor unit, resembling the biceps brachii muscle.

Gagnon et.al ³⁸ have described in detail the use of the latissimus dorsi muscle to restore elbow flexion in arthrogryposis. It involves the following steps:

1. Mobilization of the muscle

2. Exposing the two ends of the biceps in the arm through two incisions at its proximal and distal ends

3. Transposition of the latissimus dorsi muscle to the arm and anchoring the transposed muscle to the coracoid process and biceps tendon.

Patient position

The patient is placed supine on the operating table. The scapular region and the corresponding hemithorax, shoulder, arm and elbow are included in the operative field.

Incision

An incision is made along the anterolateral aspect of the latissimus dorsi muscle, extending from the posterior border of the axilla down to the last ribs (Fig. 15.3). The entire muscle is exposed and mobilized, proceeding from caudal to cephalad and taking care to free the neurovascular pedicle (thoracodorsal vessels and nerve) up to its origin in the axilla. This is necessary to allow transposition of the muscle to the arm. The latissimus dorsi muscle is detached from its origin and insertion, preserving the dorsolumbar fascia (Fig. 15.4). The coracoid process in the shoulder is then exposed through a deltopectoral incision (Fig. 15.3). The pectoralis major is mobilized to make a channel for the latissimus dorsi muscle. The biceps insertion at the elbow is then exposed through a bayonet incision. Following this, the paralysed biceps muscle is resected between these two incisions, taking care to preserve the neurovascular bundle in the arm along with the musculocutaneous nerve.

Figure 15.3 Skin incisions to expose: (1) latissimus dorsi; (2) coracoid process; (3) biceps tendon.

Figure 15.4 Mobilization of the latissimus dorsi muscle.

The body of the latissimus dorsi is loosely rolled into a cylinder, keeping the contractile fibres relatively parallel to the line of the biceps muscle and taking care to protect the neurovascular bundle.

The latissimus dorsi muscle is then passed under the skin bridge of the axilla into the anterior brachial compartment (Fig. 15.5). The insertional tendon of the latissimus is passed under the pectoralis major tendon and secured to the coracoid process (Fig. 15.6) using non-absorbable interrupted sutures. This simulates the origin of the short head of the biceps brachii. An insertional tendon for the new biceps can be fashioned from the dorsolumbar fascia of the latissimus and secured to the radius (Fig. 15.6). Fixation can be achieved by drilling a 4–5 mm hole through the radial tuberosity (Fig. 15.7). The muscle should be anchored with adequate tension (the elbow should remain spontaneously at 100° of flexion, with the forearm in supination) to avoid laxity in the muscle unit. Laxity will result in limitation of active flexion, necessitating further surgery to shorten the tendon. Gagnon et al suggested that imbricating the tendinous origin at the coracoid process and thus shortening the tendon by approximately 1 cm should retension the muscle.

Figure 15.5 Transposition to the arm: (1) coracoid process; (2) refashioned biceps tendon.

Figure 15.6 Anchoring muscle in the arm.

Figure 15.7 Anchoring muscle in the forearm.

Postoperative management

The elbow is immobilized in maximum flexion for 6 weeks.

Triceps transfer

Complete triceps transfer to restore elbow flexion only works in the short term. Thereafter severe elbow flexion contractures develop due to the unopposed flexion, resulting in functional deterioration. Hence complete triceps transfers to restore elbow flexion should be condemned.

The long head of the triceps, however, has a separate neurovascular pedicle and is independent from the rest of the triceps. As such it can be used to restore elbow flexion. If used, it may require a fascia lata graft to lengthen the tendon and allow insertion into the proximal ulna. This transfer will produce satisfactory elbow flexion without loss of elbow extension.

Steindler flexorplasty

If the flexor pronator mass of the forearm is functional then it can be used to restore elbow flexion. This is done by transferring the flexor pronator origin from the medial epicondyle to the anterior humerus. Strong radial wrist extensors are a prerequisite for this surgery as they are needed to counteract the potential flexion deformity at the wrist that can result from this transfer.

Operative technique and postoperative management

Incision

Through a curvilinear incision on the ulnar aspect of the elbow the medial epicondyle is exposed. The ulnar nerve is identified and traced distally to its entrance into the flexor carpi ulnaris muscle. The median nerve is also identified and traced to its entry under the fibrous arch of the flexor digitorum superficialis. The common flexor origin is then mobilized with a thin wafer of bone (Fig. 15.8) and the brachialis muscle identified and elevated subperiosteally from the anteromedial surface of the distal humerus.

Figure 15.8 Mobilization of common flexor origin to humerus.

The common flexor origin is anchored to the anteromedial surface of the humerus about an inch or more proximal to its original attachment to the epicondyle with the elbow in full flexion. Anchoring can be achieved by drilling a hole in the bone or by suturing the common flexor origin to the soft tissues. Improved mobility, if required, can be achieved by raising the flexor carpi ulnaris from the ulna.

Free gracilis transfer

The gracilis can be used as a free tissue transfer. However, the difficulties with this transfer are that the gracilis is usually fibrotic in arthrogryposis and has a poor source of innervation from the intercostal nerves. Like many other potential transfers that might achieve elbow flexion in arthrogrypotic children, this one is more theoretical than practical.

Outcome including literature review

Williams ³⁹ published his results of surgery on 23 arthrogrypotic elbows. Tricepsplasties were performed on four, while 19 had both tricepsplasty followed by triceps transfer. The average age of the patients at the time of operation was 6 years. The range of elbow motion improved from 7.5–26° before surgery to 42.5–108° after surgery in the four patients who underwent tricepsplasty alone. There was an average increase in the range of forearm rotation of 137° in the19 patients who had both procedures. However, the results of gain in flexor power were variable, with the best results occurring in children aged between 4 and 6 years. Younger children had a higher incidence of weak transfers. All 23 elbows achieved good functional results after the procedure. Subsequent reports, however, have condemned triceps transfers owing to the development of a flexion contracture secondary to unopposed elbow flexion.

Lahoti and Bell ⁴⁰ have reported their long-term results of six pectoralis major transfer in arthrogryposis to restore elbow flexion. They noted good early results in five of the six patients. However, an increase in flexion deformity developed over time in four of the five patients who showed initial good results, resulting in deterioration of elbow flexion. Only one patient had good function 10 years after the transfer. Lahoti and Bell recommend this transfer only for patients who maintain a good passive range of movement in the elbow following triceps lengthening and posterior capsulotomy.

Complications

Complete triceps transfers to restore active elbow flexion may be complicated by flexion contractures at the elbow due to unopposed elbow flexion. The transfer also weakens active elbow extension.

Pectoralis major flexorplasty may be complicated by the development of a flexion deformity of the elbow, resulting in a deterioration of the results.

Steindler’s flexorplasty is a relatively simple procedure but rarely gives more than 90–100° of elbow flexion and frequently causes a flexion contracture of the joint. It can also produce a pronation contracture of the forearm and on occasion produces a flexion contracture of the wrist.

Traction injuries to the neurovascular pedicle can complicate any of the flexorplasties.

Conclusions and personal view

Arthrogryposis can be considered as a symptom complex rather than a disease. The upper limb is involved in 60–70% of cases and the elbow joint is the key for rehabilitation of the upper extremity. Elbows fixed in flexion generally function well. Achieving passive elbow flexion takes priority for elbows stiff in extension. Physiotherapy to maintain a passive range of motion is quite useful, along with the use of splints. Elbow stability in extension should not be compromised, especially in children who use crutches. A posterior capsulotomy and tricepsplasty will increase the passive range of motion. Surgical transfers, including the Steindler flexorplasty, enhance flexor power and perform well in the short term, but deteriorate with time. We recommend the pectoralis major transfer only in patients who can maintain range of motion at the elbow following triceps lengthening and capsulotomy. There is some evidence that the best results are maintained if surgery is performed by the age of 4–6 years.

Congenital radial head dislocation

Introduction

Congenital dislocation of the radial head is the most common congenital anomaly of the elbow.^41,⁴² It can exist as an isolated defect or may be associated with other anomalies or syndromes.

Background, aetiology and classification

Hypoplasia of the capitellum in the developing embryo has been proposed as the cause of congenital radial head dislocation. The cause for capitellar hypoplasia, however, is unknown.⁴³ In addition, it is not clear whether capitellar hypoplasia is the cause or effect of a dislocated radial head since the removal of one bone from a developing joint can result in relative hypoplasia of the other bone. The underlying aetiology of this anomaly has been attributed to a germplasm defect.

Congenital radial head dislocation may be anterior, posterior or lateral. Posterior dislocations constitute 65% of all congenital dislocations, while anterior dislocations account for 18% and lateral for the remaining 17%.⁴² Anterior dislocations exist as an isolated anomaly and show an autosomal dominant inheritance. They can be classified based on aetiology as congenital, dysplastic (osteochondromatosis, fibrous dysplasia) and traumatic. Congenital dislocation of the radial head may be familial, especially on the paternal side, and may be associated with chondro-osteodystrophy. Like other elbow abnormalities, an association between congenital radial head dislocation and sex chromosomal abnormality (XYY syndrome) has been reported.⁴⁴

Presentation, investigations and treatment options

Presentation

Congenital dislocation of the radial head is bilateral in 30–40% of cases.^42,^45,⁴⁶ Bilateral involvement is often associated with other abnormalities^42,⁴⁶ and is usually posterior. Anterior dislocations are more common with isolated congenital radial head dislocation. Although occasionally congenital radial head dislocation may be diagnosed at birth, most cases are identified later during childhood when they present with limitation in the range of elbow movement. Full flexion of the elbow is limited in anterior dislocations and full extension in posterior dislocations. However, forearm rotation is restricted in all cases. The average reduction in forearm rotation reported in one series was 99°.⁴²

Clinical examination may identify a palpable or audible click and may reveal prominence of the radial head. Pain, commonly felt along the posterolateral aspect of the elbow, may be the presenting feature in adolescent children. It may be the result of either mechanical impingement at the elbow joint or stretching of the pericapsular tissues due to abnormal loading of the radiocapitellar joint.

Mardam-Bey and Ger ⁴² suggested additional clinical factors that help differentiate a congenital from a traumatic radial head dislocation: (1) bilateral involvement; (2) associated other congenital anomalies; (3) familial occurrence; (4) lack of a history of trauma; (5) not reducible by closed methods; (6) dislocation seen at birth.

Investigations

The classic article on this condition by McFarland ⁴⁷ in 1936 describes the radiological criteria for diagnosing congenital radial head dislocation and differentiating it from traumatic dislocations. These criteria relate to the shape of the radial head, hypoplasia of the capitellum and the shape of the posterior border of the proximal ulna. They were subsequently confirmed by Almquist et al.⁴⁸

In congenital anterior dislocations the radial head is dome shaped, with absence of the normal central depression. The capitellum is hypoplastic and may be deficient posteriorly, and the posterior proximal ulnar border is concave with apex anterior. The radius is overgrown and is too long compared to the ulna. In congenital posterior dislocations, the radial head is elongated and attenuated and there is an exaggeration of the normal convexity of the ulnar posterior border. Lateral dislocations have similar features to anterior dislocation and in addition exhibit a distinctive separation (divergence) between the proximal radius and the capitellum. Traumatic radial head dislocations are usually anterior and exhibit a normal central depression with a normally developed capitellum.

In a true lateral radiograph of the elbow, a line through the centre of the radial shaft and neck should always bisect the capitellum regardless of the degree of flexion or extension of the elbow. If it does not, a radial head dislocation or subluxation must be suspected.

Arthrography has been used to differentiate traumatic from congenital radial head dislocations.⁴⁹ In congenital dislocations the radial head is displaced from the capitellum but well covered by the capsule of the elbow joint, suggesting that the lesion is an intra-articular dislocation of the head, whereas traumatic dislocations show no capsule covering the radial head suggesting an extra-articular dislocation.

The ossification centre of the radial head appears at age 5 years in girls and 6 years in boys. As a result, ultrasound may occasionally be useful to demonstrate a radial head dislocation below the age of 6.

The classic radiographic features may not be present in all cases of congenital radial head dislocations and in these cases radiographs of the opposite elbow with an ipsilateral arthrogram or MRI is indicated to confirm the diagnosis.

Treatment options

A thorough clinical examination to rule out associated congenital abnormalities is of paramount importance. A skeletal survey may be needed in patients with multiple musculoskeletal anomalies.

The literature on the surgical management of congenital radial head dislocation is very sparse. Most of the studies on surgical intervention are simple case series without control groups and hence do not provide enough data to make firm conclusions. Asymptomatic children with minimal restriction of activities of daily living should be observed. For symptomatic patients either open reduction of the radiocapitellar joint ^41,^45,^50,⁵¹ or radial head excision^42,^45,^52,⁵³ should be considered.

Surgical technique and rehabilitation

Open reduction of the radial head dislocation

Open reduction of the radial head with an ulnar osteotomy and annular ligament reconstruction has been reported in the management of congenital radial head dislocation. However, this technique is associated with a high recurrence rate, due to loss of the bony buttress resulting from the capitellum being hypoplastic or an oblong radial head. It has also been reported to be ineffective at improving the range of motion at the elbow joint.^45,⁵⁴ Improvement in forearm rotation has, however, been noted if the procedure is performed in very young children (younger than 2 years). Sachar and Mih⁴¹ postulated that early reduction of a radial head dislocation resulted in the normal formation of the radiocapitellar joint in a similar way to that seen with developmental hip dysplasia.

Radial head excision

Excision of a dysplastic radial head should be delayed until skeletal maturity. If at that stage the patient complains of pain and undue prominence of the radial head, the symptoms can be successfully treated with radial head excision. However, functional impairment due to loss of motion is not improved by excision. This is due to soft tissue contractures that develop in long-standing dislocations that do not yield even after excision of the bony bar.

Rotational osteotomy of the radius

Since the radial head has its maximum stability with the forearm externally rotated, a rotational osteotomy of the radius may help to maintain the reduction of the radial head. It works by releasing the tension on the biceps, which is the factor responsible for recurrent anterior dislocation and increasing the tension of pronator teres and pronator quadratus. This osteotomy of the radius is usually done at the mid-diaphyseal level. Occasionally radial shortening may have to be done if there is radial overgrowth.⁵⁵ By undertaking a rotational osteotomy of the radius Futami et al achieved anatomical radiographic reduction of the radial head in five patients with congenital radial head dislocation and one post-traumatic dislocation.

Outcome including literature review

The current literature on the surgical management of this congenital anomaly is very sparse. Most of the studies on surgical intervention are simple case series without control groups and hence do not provide enough data on which to make firm conclusions.

There is, however, universal agreement to avoid surgery if there is little or no restriction in activities of daily living.^41,^42,⁵²

Although radial head excision relieves pain, it does not improve the range of forearm rotation. Yamazaki and Kato ⁵¹ have reported good long-term results following open radial head reduction undertaken in a patient with bilateral congenital radial head dislocation. However, their case lacked the typical radial head morphology characteristic of congenital dislocation. Annular ligament reconstruction was performed using the fascia of extensor carpi ulnaris.

Kim et al ⁵⁰ published their results of open reduction and reconstruction of 15 elbows with chronic radial head dislocations. Three of these were congenital and the rest were post-traumatic in aetiology. The average age of the children was 9.5 years. Two of the three congenital cases showed persistent subluxation on the follow-up radiographs.

Excision of the radial head gets rid of pain and undue elbow prominence but functional impairment due to loss of motion is not improved.