JORT

Introduction

Treatment of intercondylar fractures of the humerus is difficult and controversial. Prior to the last two decades the consensus favoured non-operative management because of the poor operative results. [1] In the last decade there has been advances in the understanding of elbow biomechanics, improvement in surgical techniques, new innovative fixation devices and postoperative rehabilitation protocols [2]. The principles set out by the Association for the Study of Internal Fixation (AO- ASIF), including anatomical articular reduction and rigid internal fixation, allow for healing and early postoperative range of motion. [2] In young patients, open reduction and internal fixation of distal humerus fractures using modern fixation principles are considered the gold standard. [2] In elderly patients, restoration of the anatomy and obtaining rigid internal fixation may be difficult because of poor bone quality and comminution of articular surfaces and metaphysis. In cases in which rigid internal fixation cannot be achieved to allow early range of motion, resultant prolonged immobilization often leads to poor outcome [2].Primary total elbow arthroplasty has evolved to become a treatment option for elderly patients with articular fragmentation, comminution, and osteoporotic bone [3].

Review of Literature

Anatomy

The lower end of the humerus presents articular and non articular portions. The articular portion takes part with the radius and ulna in formation of the elbow joint.The distal humeral shaft is triangular shaped in cross section; with its apex directed anteriorly. As the shaft approaches the distal humerus it bifurcates into two divergent cortical columns, termed the medial and lateral columns [4]. The medial column diverges 45 degrees from the humeral shaft in the coronal plane and termed as medial epicondyle [5]. The lateral column diverges at 20 degrees in the coronal plane from the shaft. As it extends distally it curves anteriorly creating an angle of 35-40 degrees with the shaft in sagittal plane (Figure1-2) [6]. The lower end of the humerus is divided by a faint groove into a lateral convex surface termed the capitellum, and medial pulley shaped surface termed trochlea. In the coronal plane, the trochela is more distal than the capitellum resulting in a valgus alignment of 4 to 8 degrees. At their most distal points, they are joined by the “tiearch,” consisting of the articular segment - the trochlea and the capitellum [6]

Figure 1: Configuration and angulations around distal humerus. [3]

Figure 2: Columns of the distal end of humerus and tie arch [6]

The capitellum is a rounded, convex projection, considerably less than a half of a sphere which covers the anterior and inferior surfaces of the lateral part of the condyle of the humerus but doesn't extend on to its posterior surface. It articulates with the disk-like head of the radius, which lies in contact with its inferior surface in full extension of the elbow, but moves to its anterior surface when the elbow is flexed [7]. The trochela is a pulley shaped surface which covers the anterior, inferior and posterior surfaces of the condyle of the humerus. Its medial margin projectd downwards beyond the rest of the bone. It articulates with the trochlear notch of the ulna (Figure 3) [8].

Figure 3: Bony anatomy of the elbow joint [4].

When the elbow is extended, the posterior and the inferior surfaces of the trochlea are in contact with the ulna, but as the joint is flexed the trochlear notch rolls forwards on to the anterior aspect and then the posterior aspect is then left uncovered [7]. The medial supracondylar crest is concave from behind and straight medially while lateral supracondylar crest is concave from behind and curved laterally. The medial epicondyle projects on the medial portion of the condyle. Its posterior surface is smooth and close to the ulnar nerve, which lies in a shallow groove as it descends down into the forearm. In this situation, the nerve can be felt and rolled against the bone. The lower part of the anterior surface of the medial epicondyle shows an impression which gives attachment to the superficial group of the flexor muscles of the forearm [9,10]. The lateral epicondyle occupies the lateral part of the non-articular portion of the lower humerus, but doesn't project beyond the lateral supracondylar ridge. Its lateral and anterior surfaces show an impression which gives an attachment to the superficial group of extensor muscles of the forearm. Its posterior surface is slightly convex and can easily be felt through the skin at the back of the elbow [6]. The lateral border of the humerus terminates at the lateral epicondyle and its lower portion is termed lateral supracondylar ridge. The medial border of the humerus terminates at the medial epicondyle and its lower portion is termed the medial supracondylar ridge [11]. Immediately above the trochlea on the posterior surface of the bone, a deep hollow is situated and is termed the olecranon fossa which lodges the tip of olecranon when the elbow is extended. A similar, but smaller hollow lies immediately above the trochlea on the anterior surface of the bone and is termed the coronoid fossa which lodges the coronoid process during flexion of the joint. The radial fossa is a very slight depression above the capitellum on the lateral side of the coronoid fossa, it is related to the margin of the radius in full flexion of the elbow [5]. The non-articular portion includes the medial and lateral epicondyles together with the olecranon, coronoid and radial fossae.

The Head of the Radius

It is a disc shaped structure , its upper surface is hollowed out to form a shallow cup for articulation with the capitellum of the humerus. Its circumference is smooth and is deepest on the medial side where it articulates with the radial notch of the ulna [12].

The Upper End of the Ulna

It displays two substantial processes, the olecranon and the coronoid, and two articular areas, the trochlear and radial notches, which articulate with the humerus and radius respectively. The olecranon is the uppermost part of the bone , its anterior surface is smooth and articular and forms the upper part of the trochlear notch, while its posterior surface is triangular in outline. The coronoid process projects from the front of the bone immediately below the olecranon. Its upper surface forms the lower part of the trochlear notch and is therefore smooth and articular. The upper part of the lateral surface presents the shallow radial notch for articulation with the head of the radius. The trochlear notch articulates with the trochlea of the humerus, it is formed by the anterior surface of the olecranon and the superior surface of the coronoid processes. The bone is constricted at the junction of these two areas and they may be separated by a narrow strip. A smooth ridge which corresponds to the groove of the trochlea, divides the notch into a large medial and smaller lateral parts. The medial part conforms to the large flange of the trochlea of the humerus [9,10,13,14]. The synovial membrane is attached to the articular margins of the joint and lines the capsule and annular ligament. The capsule attaches to the articular margin except at the coronoid, radial, and olecranon fossae, where it attaches to the rim of the fossae. The joint capsule does not attach to the radius; it is confluent with the annular ligament that attaches to the anterior and posterior margins of the sigmoid notch and encircles the radius (Figure 4).

Figure 4: Elbow capsule and synovial reflections (A) anterior view (B) posterior view [17].

Haversian fat pads are located in each of these fossae between the capsule and synovial membrane. Distention of the joint by hemarthrosis displaces these fat pads out of their respective fossae and produces the characteristic“fat pad sign” seen on lateral radiographs (Figure5) [15].

Figure 5: Sagittal view of the elbow showing intra-capsular    extra-synovial Haversian fat pad [15].

The anterior capsule becomes taut in extension and is an important stabilizer of the extended elbow. The maximum joint capacity is 25 to 30 ml at approximately 80° of flexion [15].The ligamentous complexes that stabilize the joint are thickenings of the capsule on its medial and lateral aspects. The medial collateral ligament complex consists of three components: the anterior and posterior bundles and the transverse ligament. The anterior bundle is structurally and biomechanically the significant component of the medial collateral ligament complex and has three functional bands. The first band arises from the anterior surface of the medial epicondyle and is taut in extreme joint positions. The second band arises from the tip of the epicondyle and is taut in intermediate joint positions. The third band, which arises from the inferior edge of the epicondyle, is taut throughout the full range of joint motion (isometric). The anterior bundle attaches to the sublime tubercle on the medial aspect of the coronoid process. The posterior bundle (Bardinet’s ligament) of the medial collateral ligament complex is fan shaped and attaches posterior to the axis of rotation on the medial epicondyle. It attaches to the middle of the medial margin of the trochlear notch and is taut during flexion. This ligament is important because it provides stability to the elbow against pronation. The transverse ligament of Cooper (olecranon-coronoid ligament) is not always well defined and does not contribute to joint stability because it is limited only to the ulna. The medial collateral ligament complex lies deep to the prominence of the medial epicondyle (Figure 6) [16,17].

Figure 6: Medial ligament complex of the elbow [16].

The lateral ligament complex consists of four components: the radial collateral, the annular, the lateral ulnar collateral, and the accessory lateral collateral ligaments. The radial collateral ligament attaches to the lateral epicondyle and merges indistinguishably with the annular ligament. The annular ligament attaches to the anterior and posterior margins of the radial notch of the proximal ulna, encircling the radius but not attaching to it. The most distal part of the annular ligament has a smaller diameter that encircles the neck to provide greater stability (Figure 7).

Figure 7: Articular capsule and its relation to annular ligament [15].

The lateral ulnar collateral ligament attaches proximally to the lateral epicondyle and distally to the tubercle of the supinator crest of the ulna. It is the primary lateral stabilizer of the ulnohumeral joint, and its deficiency is the “essential lesion” that produces posterolateral rotatory instability. The capsule posterior to this ligament is also important because it provides resistance against supination (Figure 8).

Figure 8: Lateral ligament complex of the elbow [18,19].

The accessory lateral collateral ligament blends proximally with the fibers of the annular ligament and distally attaches to the tubercle of the supinator crest. The function of the accessory ligament is to stabilize the annular ligament during varus stress [18,19]. The quadrate ligament of Denuce is a thin fibrous layer between the inferior margin of the annular ligament and the ulna. It is a stabilizer of the proximal radioulnar joint during full supination. The oblique ligament is a small and inconstant ligament formed by the fascia overlying the deep head of the supinator between the ulna and radius just below the radial tuberosity. It has no known functional importance, but some authors believe that this ligament is a cause of rotatory contractures of the forearm [19].

Blood Supply to the Elbow

There is a consistent blood supply to the elbow which can be divided into three vascular arcades: medial, lateral and posterior. The lateral arcade is formed by the interosseous recurrent, radial recurrent and radial collateral arteries and supplies the capitellum, radial head, lateral epicondyle and lateral aspect of the trochlea. The medial arcade is formed by the superior and inferior ulnar collateral and anterior and posterior ulnar recurrent arteries and supplies the medial epicondyle and the medial aspect of the trochlea. The posterior arcade is formed by the medial collateral artery and contributions from the medial and lateral arcades and supplies the olecranon fossa and supracondylar area (Figure 9) [20].

Figure 9: Vascular supply of distal end of the humerus (A).anterior view (B).posterior view [20].

SUC: Superior Ulnar Collateral IUC: Inferior Ulnar Collateral PUR: Posterior Ulnar Recurrent RR: Radial Recurrent RC: Radial Collateral IR: Interosseuos Recurrent MC: Medial Collateral

Biomechanics

The elbow-forearm complex represents a link in a mechanical chain of levers which begins at the shoulder and ends at the finger tips. Elbow motion serves to adjust the height and length of the limb to reach any point within the sphere made by shoulder motion [21]. The elbow is a compound joint with two degrees of freedom. The ulno-humeral part of articulation consisting of a hinge permitting one degree of freedom that is flexion-extension motion about the transverse axis of the distal humerus. The second degree of freedom at the elbow is made by radio-humeral and radio-ulnar joints, this articulation allows rotation of the forearm around a second longitudinal axis which is approximately perpendicular to the elbow axis and moves in the plane of flexion-extension. Partly because of the increased depth of the medial lip of the trochlea and partly because of the obliquity of the articular surface of the coronoid process which is not set at right angle to the shaft of ulna, an angle is made between the longitudinal axis of the humerus and the extended fully supinated forearm. This angle is called the "carrying angle" and lies within the range of zero to twenty degrees of valgus with tendency towards the higher side of range in women (Figure10) [22].

Figure 10: Measurement of the carrying angle [22].

Despite the deviation in extension, this angle disappears in flexion as the forearm and humerus become closely aligned and the hand lying in front of the shoulder. Morrey and Chao reported that the long axis of the forearm changes linearly from valgus to slight varus during flexion; they also noted that the ulna and hence the entire forearm rotates about its long axis during flexion extension motion irrespective of the degree of supination or pronation [23]. An internal rotation of five degrees occurs during early flexion and an external rotation of five degrees occurs during terminal flexion, this probably due to the configuration of articular surfaces and ligaments. Flexion-extension capability of the elbow ranges from zero to one hundred and forty six degrees. This range of motion is limited at maximum extension of zero degree by:

1. The geometry of the joint surface and surrounding bones.
2. Passive supporting structures represented by collateral, capsular and other ligaments.
3. Active moving structures represented by muscles and tendons.

However, the limits for flexion depend on whether it is active or passive; the most important limitation for active flexion is the opponens of the contracted muscles of the arm with the forearm while other factors such as tension in the posterior capsular ligament and impact of coronoid process on the humerus are insignificant. As for passive flexion the anterior muscles of the forearm are flattened and other factors become more important i.e. the impact of radial head against the radial fossa, the coronoid process against the coronoid fossa, tension of the posterior capsular ligaments and tension developed passively in the triceps muscles. As regards rotation of the forearm, a movement which is produced by the radio-ulnar joints, it is basically produced by movements of the radius around the immobile ulna. The axis of this movement passes between the centre of the head of the radius and the base of the sytloid process of the ulna and when prolonged it passes near the little finger. It lies in line with the shaft of the humerus but oblique to the shaft of the ulna. Normal pronation is seventy-one degrees and supination is eighty-four degrees [24].

Muscle Function

The major flexors across the elbow joint are the brachialis, biceps brachii, brachioradialis, and extensor carpi radialis. The brachialis has the largest work capacity and potential contractile strength. It is active regardless the elbow position, type of contraction, or rate of movement, and the position of the shoulder does not affect these factors [25]. Major elbow extensors are the triceps, extensor carpi ulnaris, and anconeus. The triceps has the largest work capacity, and its medial head is the primary force producer. The position of the elbow affects the triceps; however, the position of the shoulder (excluding the long head) does not affect it. The anconeus is active in a variety of motions, so it is considered to be the dynamic stabilizer of the joint [26]. The muscles involved in pronation include the pronator quadratus and pronator teres. The primary pronator of the forearm is the pronator quadratus. The position of the elbow does not affect the pronator quadratus. The pronator teres functions as a secondary pronator during rapid pronation or during pronation against resistance [25]. The muscles involved in supination of the forearm are the supinator and the biceps. Supination is achieved primarily by the supinator muscle, with the biceps acting in a secondary role. The supinator acts independently during slow, unrestrained supination. During restrained or rapid supination or resisted supination in any position, the biceps assists the supinator muscle. When the biceps assists supination, the extensors must act antagonistically to cancel any flexion that the activity of the biceps creates, resisting varus stress, valgus stress, and joint distraction in extended and 90° flexed positions. In the flexed position, the medial collateral ligament provides 55% of the varus torque needed to resist the valgus stress.

The soft tissues and capsule provide 11% of the resistance to valgus stress, and osseous articulation provides approximately 34% of this valgus resistance. In the extended position, the medial collateral ligament provides 31% of the resistance to valgus stress, with the capsule and joint articulation providing 38% and 31%, respectively. The lateral collateral ligament, anconeus, and joint capsule provided stability for resisting varus stress. At 90° of flexion, the lateral collateral ligament contributes 10% of the valgus torque needed to resist varus stress, and the joint articulation and joint capsule provide 75%and 15%, respectively. In the extended position, joint articulation provides 55% of the resistance to varus stress, and the lateral collateral ligament and joint capsule provide14% and 31%, respectively. Resistance to joint distraction is dependent on the position of the elbow. At 90° of flexion, the medial collateral ligament primarily provides 78% of the resistance to distraction. The lateral collateral ligament contributes 12%, and the joint capsule provides 10%. In the extended position, the contribution to distraction resistance is reversed; the joint capsule provides 85% of the resistance, and the lateral and medial collateral ligaments provide 7% and 8%, respectively [27].

Classification

Several classification systems for intra- articular both column fractures of the distal humerus have been proposed.

In 1936, Reich first described “T” and “Y” intercondylar fractures [28].

In 1969, Riseborough and Radin (Figure11) [29]described 4 types of intercondylar “T-type” distal humerus fractures:

• Type 1: Non-displaced fracture,
• Type 2: Displaced but without rotation of the fragments,
• Type 3: Includes fragment rotation,
• Type 4: Involves severe comminution.

Although initially relevant for its descriptive value, these classifications proved inadequate in reliably describing the fracture and directing treatment as these injuries were more frequently treated operatively.

Figure 11: Riseborough and Radin classification of the distal humerus fractures [29].

The Orthopaedic Trauma Association’s(OTA) alpha-numeric system [30], based on the comprehensive classification of fractures of long bones, assigned three main types:

• Type A: Extra-articular.
• Type B: Partial articular.
• Type C: Complete articular.

Sub-types were given thereafter for further fracture details. Although useful for cataloging fractures for research purposes, the clinical application of the system is limited and hindered by poor inter-observer reliability beyond identification of the basic three types (Figure 12).

Figure 12: The AO classifications of the distal humerus fractures [30].

Jupiter and Mehne [31], developed a different comprehensive system based on the surgical anatomy and the techniques used for reconstruction. There are three basic categories as follows (Figure 13):

Grade I: Intra-articular fractures subdivided into: A: Single column.  B: Bicolumnar.   C: Capitellar. D: Trochlear.

Grade II: Extra-articular, intra-capsular fractures.

Grade III: Extra-capsular fractures subdivided into: A: Medial epicondylar.   B: Lateral epicondylar.

Figure 13: Summary of the Jupiter and Mehne system for the classification of distal humeral fractures [31].

Epidemiology/Mechanism of Injury

Distal humerus fractures represent 2% of all fractures and approximately 30% of those involving the humerus [32]. A population-based study examining all patients presenting to a single center identified a bimodal distribution with peak occurrences in young males (12-19 years) and elderly females (80 years). Robinson et al, identified an incidence of 5.7 of 100,000 in the population per year with a nearly equivalent male-to-female ratio [33]. Over 25-year period, the incidence of distal humerus fractures among patients older than 60 years of age nearly tripled (11-30%). Furthermore, the incidence in 2030 is projected to be 52 of 100,000 [33] Motorized vehicles and extreme sports contribute to the severity and incidence of distal humerus fractures in the young. By contrast, elderly patients generally present following a low- energy ground level fall [34]. Mechanism of injury of this fracture is probably caused by the impact of the ulna in the trochlear groove, forcing the condyles of the distal humerus apart. The injury may occurs in either flexion or extention. In flexion type injury, Palmar (1961) has speculated that the elbow against the posterior elbow (olecranon) coupled with contraction of the forearm muscles, produce the fracture with less force than expected. In many instances, however, the forces applied to the posterior flexed elbow are violent, as in road traffic accident. In flexion type fracture, the condyles are usually found anterior to the humeral shaft. In the extention type fracture the condyles are usually found to lie posterior the humeral shaft. In the extention type injury, the ulna is directed anteriorly against the posterior aspect of the trochela, separating the condyles at the same time as supracondylar portion is fractured [35].

Modalities of Management

Closed techniques

a) Cast immobilization: this involves closed manipulation and immobilization in cast. This management represents the worst, due to inadequate reduction and prolonged immobilization [36].

b) Traction: Most popular of the closed technique used only in severe comminuted injury. The commonest method is the overhead olecranon pin traction. This method is very cumbersome and requires prolonged stay in the hospital .Accurate reduction is not possible and reported methods are inconsistent. Only very small series are documented supporting this method [37] (Figure14).

Figure 14: Over head olecranon pin traction [37].

c) Bag of bones technique: promoted by Eastwood-Hugh Owen Thomas. The arm is placed in a cuff & collar sling with elbow in as much flexion as possible. The elbow is left hanging free and early mobilization of hand, shoulder and elbow is encouraged [38].

Open Reduction and Internal Fixation:

The goal of operative treatment is to restore elbow function by obtaining anatomic and stable reduction of the articular surface. Central to this goal is rigid fixation of the anatomic surface so that early motion may be instituted. Partial articular fractures with large fragments can be fixed directly using the lag technique to the intact medial or lateral column. Complete articular fractures are managed by converting them to a partial injury by quickly restoring one column. Thereafter, remaining fragments are fixed to the stabilized column. Alternatively or in conjunction with this method of fixation, 1 or 2 screws can be directed along the axis of elbow rotation through the trochlea and capitellum. Whenever possible, these screws should be passed through contoured plates to provide additional stability. Inter-fragmentary compression should be used with caution in the presence of articular comminution where the articular surface may be inadvertently shortened or deformed resulting in restriction of ulno-humeral motion. In addition, osteochondral fragments should be retained whenever possible and secured with buried implants; such as countersunk mini-fragment screws, headless variable pitch screws, or small threaded K-wires. Screw fixation alone is seldom adequate to provide the type of rigid fixation needed to permit early motion. Plate fixation of the distal humerus has traditionally involved two orthogonal plates, as described by the AO-ASIF group [39]. One plate is placed along the posterolateral aspect of the distal humerus along the lateral column and capitellum. The second plate is placed medially and is contoured around the medial column. In cases with significant comminution or osteoporosis a third plate can be applied posteriorly along the lateral column for additional fixation [40]. Locking compression plates offer improved stability in areas where screw purchase may be tenuous. Locked plates have been shown to provide a marked increase in resistance to bending, torsion, and axial compression loading among distal humerus fractures as compared to standard fixation with traditional non- locking plates [41]. O’Driscoll recently defined principles of fixation of distal humerus fractures using parallel locking pre-contoured plates and defined two goals that should be met: First, fixation within the distal fragment must be maximized, and second, all fixation in distal fragments should contribute to stability between the distal fragments and the shaft [42].

In addition, he defined eight technical objectives by which these principles are met:

1. Every screw in the distal fragments should pass through a plate.
2. Every screw should engage a fragment on the opposite side that is also fixed to a plate.
3. As many screws as possible should be placed in the distal fragments.
4. Each screw should be as long as possible.
5. Each screw should engage as many articular fragments as possible.
6. The screws in the distal fragments should lock together by inter-digitation, creating a fixed- angle structure.
7. Plates should be applied such that compression is achieved at the supracondylar level for both columns.
8. The plates must be strong enough and stiff enough to resist breaking or bending before union occurs at the supracondylar level.

These principles can be achieved using parallel plates. Linking the plates together through the bone with screws, thereby creating the architectural equivalent of an arch, offers the greatest biomechanical stability for comminuted distal humeral fractures [43]. The arch is formed by inter-digitation of locking screws passing through the distal fragments from both plates in the sagittal plane. In cases involving significant metaphyseal comminution, two treatment options exist. The first is to resect the comminution and shorten the distal humerus to achieve contact, compression, and union [44]. The second option is to bridge the comminution with longer plates. The rich blood supply around the humerus facilitates healing when stable fixation is achieved proximally and distally to the comminution. The addition of bone graft can also augment healing.

Total Elbow Arthroplasty

In cases of highly comminuted articular fractures in a low demand, osteoporotic elderly patients or fractures occuring in elbow with pre- existing inflammatory joint destruction, the experienced surgeon may decide that the distal humerus is not reconstructable. Total Elbow Arthroplasty (TEA) using a semiconstrained prosthesis has been shown in several studies to be effective primary treatment, at least in the short term. The disadvantages of total elbow arthroplasty for acute fractures include the functional restrictions imposed upon the patient, the risk of serious complications such as infection, and the potential for failure of prosthetic articulations with the possible need for revision. Infirmity and activity level are used rather than age when considering total elbow arthroplasty for fracture treatment [45,46].

Complications

Complications are common in the management of distal humerus fractures and include elbow stiffness, heterotopic ossification, nonunion, neuropathies, and infection. Post-traumatic elbow stiffness can arise from both intrinsic and extrinsic sources. Intrinsic causes of stiffness include joint adhesions, synovitis, articular incongruity, and intra-articular loose bodies. Extrinsic causes include capsular contractures and heterotopic ossification. Loss of some motion is expected after distal humerus fractures, particularly terminal extension. Loss of flexion is less tolerated than loss of extension. Although functional range of motion has been defined as 30 to 130 degrees of flexion, even small decreases in motion can cause functional impairment depending upon the patient’s needs. Post-traumatic elbow stiffness is best managed by avoidance and diligent post-operative rehabilitation. During the early post-operative period motion should be instituted and edema minimized. Also, splinting in full extension will tension the anterior capsule, compress posterior structures, and relax the ulnar nerve. Lack of progression in motion over the first 3 post-operative months warrants more aggressive modalities including serial casting and static progressive splinting. If non-operative methods fail to restore motion, patients can be considered for surgical release. Both open and arthroscopic techniques have proven successful in restoring motion [47]. Heterotopic ossification is common after distal humerus fractures. Susceptible patients include those with brain or spinal cord injury, severe trauma or open injuries, and a history of prior heterotopic ossification. Such patients should receive prophylaxis against heterotopic ossification such as Indomethacine . Up to 3% of patients with local injury to the elbow develop heterotopic ossification but in most cases do not cause functional impairment.

Traditionally, the teaching has been to wait until complete radiographic maturation of the heterotopic bone, typically 12 to 18 months, before attempting excision. However, the recurrence rate after early excision, such as 3 to 6 months post-operatively, combined with external beam radiation has been shown to be no higher than that for delayed excision and as such is becoming the favored approach [48]. Early excision also provides the advantage of minimizing capsular and ligamentous contracture, muscular atrophy, and articular degeneration from restricted motion [47]. Nonunion occurs in 2 to 10% of distal humerus fractures treated with open reduction internal fixation [49]. Risk factors include comminution, bone loss, and inadequate fixation. Treatment options include revision of open reduction and internal fixation with bone graft or total elbow arthroplasty in older low-demand patients with poor bone stock [49,50].Neuropathy, particularly of the ulnar nerve, may occur from the initial injury, iatrogenically during surgery, or secondarily from post-operative scarring. Release and subcutaneous transposition of the ulnar nerve at the time of surgery reduces the risk of future neuropathy. Despite adequate release and transposition, irritation and transient sensory changes have occurred in up to 50% of patients in some series [51-53]. McKee et al, found that neurolysis and transposition resulted in significant symptomatic relief and functional improvement for patients with post-operative ulnar neuropathy [54]. However, improvement in motor strength is often incomplete and may take several years.

Deep infection is uncommon occurring on an average of 3% of patients. Risk factors include open fractures with massive contamination and devascularized segments of bone and soft tissues. Urgent debridement is mandatory. In refractory cases and those with failure of fixation, removal of implant is required [55].

Other significant complications associated with these fractures include joint osteoarthrosis, complications related to olecranon osteotomy including non-union, heterotropic ossification, hardware removal for prominence, avascular necrosis, and elbow instability [47].

Aim of the Work

The aim of this work was to study the results of treatment of displaced intercondylar fractures of the lower end of the humerus in adults by open reduction and internal fixation using double plate technique.

Patients

The study included randomly collected 20 patients with intercondylar fractures of distal end humerus, treated by open reduction and internal fixation by double plate technique in El-Hadara University Hospital from January 2011 to July 2012.

Sex

The study included 12 males (60%) and 8 females (40%). (Figure16)

Figure 16: Distribution of studied cases according to sex.

Full preoperative assessment including clinical and radiological examination with routine investigations were done for every patient.

Age

The age of the patients included in the study ranged from 18 to 70 years with a mean age of 41 years. (Table 1) (Figure 15).

Figure 15: Distribution of studied cases according to age

Table 1: Distribution of the studied cases according to age.

Occupation

Heavy manual workers as farmers, construction workers etc. were 9 patients (45%), while 11 patients (55%) were adopting sedentary work. (Figure17).

Figure 17: Distribution of studied cases according to occupation.

0 <30     < 40       < 50       50 or more Age

Table 2: Distribution of the studied cases according to occupation.

Medical history

One patient was diabetic and hypertensive, one patient was hypertensive and one patient had ischemic heart disease.

Side

The study included 13 patients presented with right side fracture distal humerus, 7 patients presented with left side fracture and no cases presented with bilateral fracture. (Table3) (Figure18).

Table 3: Distribution of the studied cases according to side affected

Figure 18: Distribution of studied cases according to side affected.

Dominant side

18 patient were right handed and only 2 cases were left handed, one of them had fracture in left side distal humerus (Table 4).

Table 4: Distribution of the studied cases according to dominant side

Mechanism of injury

Road Traffic Accident (RTA) was the responsible mechanism in 12 patients (60%), simple fall on elbow in 7 patients (35%) and fall from height in one patient (5%). (Table 5) (Figure 19).

Table 5: Distribution of the studied cases according to mechanism of injury

Figure 19: Distribution of the studied cases according to mechanism of injury.

Fracture Type

Adopting AO classification, there were 3 patients with C1 fracture type, 8 patients presented with C2 fracture type , 9 patients with C3 fracture type (Table 6).

Table 6: Distribution of the studied cases according to fracture classification.

Open Fractures

Only 4 cases were open fractures (20%). Three of them were open grade one (G I) and one was open grade two (G II). (Table 7) (Figure 20).

Table 7: Distribution of the studied cases according to whether open or closed.

Figure 20: Distribution of the studied cases according to whether open or closed.

Associated injuries

We had 4 cases with associated injures (20%). Three patients had head injury (15%), one of them had ribs and patella fractures and was admitted to ICU and another one had calcaneus fracture (5%). One patient had fracture distal end radius (5%).(Table 8) (Figure 21).

Table 8: Distribution of the studied cases according to associated injuries

Figure 21: Distribution of the studied cases according to associated injuries.

Time Lapse between Injury And Operation

It ranged from 1 day to 14 days with a mean time 3± 2.99 days.(Table 9)

Table 9: Distribution of the studied cases according to time lapse before operation

Operative Time

It ranged from 40 till 70 minutes with a mean operative time 50.75± 6.93 minutes.

Table 10: Distribution of the studied cases according to Operative time.

Methods

Patients were be examined according to a special sheet [56]

I. Methods of diagnosis:

(A) History:

• Name
• Sex
• Age
• Address
• Occupation
• Date of admission
• Side affected
• Mechanism of injury
• First aid treatment
• Time elapsed between trauma and admission to the hospital

(B) Clinical Examination:

- General examination: included evaluation of the general condition of the patient.

- Local examination:

- Swelling

- Deformity

- Skin condition

- Tenderness

- Associated injury

- Neurovascular complications

(C) Radiological examination:

1. Plain x-ray anteroposterior and lateral projections of the elbow had been done to assess the type of the intercondylar fractures.
2. CT when indicated.

II. Methods of treatment

(A) First aid management

• Care of the general condition and associated injuries.
• Immediate debridement of wounds in open fractures.
• Above elbow slab was applied initially for immobilization.
• All patients with open fractures received prophylactic antibiotics.
• As soon as their general condition permitted, patients were prepared for internal fixation
• Laboratory investigations:
• Full laboratory investigations were done for every patient including:
• Complete blood picture.
• Fasting blood sugar.
• Bleeding and clotting time.
• Blood urea and creatinine.
• Liver enzymes

(B) Open Reduction and internal Fixation

1. Anesthesia and position of the patient:

Under general anesthesia, with the patient in the prone position, with the elbow was flexed at right angle over an arm board to allow free movement of the elbow. A pneumatic tourniquet was applied in 10 cases and deflated after 60–90 minutes to minimize the chances of tourniquet palsies.

2. Exposure:

The posterior approach (Bryan-Morrey Approach [57] was done.

• A straight posterior incision in the midline of the limb extending from 7 cm distal to the tip of the olecranon to 9 cm proximal to it. the ulnar nerve was identified proximally at the medial border of the medial head of the triceps, and dissected free from its tunnel distally to its first motor branch
• The medial aspect of the triceps was elevated from the humerus, along the intermuscular septum, to the level of the posterior capsule.
• The superficial fascia of the forearm was incised distally for about 6 cm to the periosteum of the medial aspect of the olecranon.
• The periosteum and fascia were carefully reflected as a single unit medially to laterally .The medial part of the junction between the triceps insertion and the superficial fascia and the periosteum of the
• a were the weakest portion of the reflected tissue. Care was taken to maintain continuity of the triceps mechanism at this point; the triceps tendon was carefully dissected from the olecranon when the elbow was extended to 20 to 30 degrees to relieve tension on the tissues, and then the remaining portion of the triceps mechanism was reflected .
• To expose the radial head, the anconeus was reflected subperiosteally from the proximal ulna; the entire joint was widely exposed .
• The posterior capsule usually was reflected with the triceps mechanism, and the tip of the olecranon was be resected to expose the trochlea clearly.
• During closure, the medial collateral ligament was carefully repaired if its release was necessary.
• The triceps was returned to its anatomical position and sutured directly to the bone through holes drilled in the proximal aspect of the ulna.
• The wound was closed in layers, and a radyvac was put in the wound.
• This exposure permited good exposure of the distal humerus by reflecting the triceps tendon and its insertion from medial to lateral. The reflected triceps tendon maintained its attachment to the ulnar periosteum and anconeus thereby preserving its length. The main advantage of this approach was that it avoided the complications associated with an olecranon osteotomy. Identification of ulnar nerve at the time of surgery is important to prevent its injury [58-60].

Figure 22: Bryan-Morrey extended posterior Approach of the elbow [60].

3. Reduction and fixation of the fracture:

Articular Reconstruction

The principles of peri-articular fracture fixation include restoration of the articular segment, column realignment and rigid fixation to allow for early mobilization. Preliminary fixation of the articular segment was performed with Kirschner wires (K- wires) .Several K-wires were required for temporary fixation, therefore, they were placed strategically taken in to consideration final plate and screw position. The main fragments of the articular segment were fixated by 2 methods. The first method was the placement of a central screw down the axis of the trochlea to fixate the 2 main fragments. Another method was provisional fixation of the articular segment with K-wires followed by definitive fixation with screws placed through medial and lateral plates applied in a parallel manner .In cases with articular comminution, the comminuted minor fragments were fixated to the major fragments with threaded K-wires or headless compression screws [61].

Column Reconstruction

Once the articular segment has been provisionally fixed, it was rigidly linked to the humeral diaphysis. Provisional fixation of the articular segment to the diaphysis was performed with K-wires inserted retrograde from distal to proximal. Several different plating techniques exist, including orthogonal plating (90:90) which was used in this study. Following surgery the elbow was placed through a range-of motion to ensure there is no impingement, hardware prominence or instability. Intraoperative fluoroscopy was done to ensure all hardware was extra-articular [62].

Plating Technique

Orthogonal Plating (90:90)

The AO group has recommended an orthogonal (perpendicular or 90/90) plate configuration to maximize stability and allow early mobilization [63,64]. Internal fixation was done using double plates one of them was 3.5mm reconstruction plate medially applied and the other was 3.5mm reconstruction plate posterolaterally applied. The wound was closed and the limb immobilized in a plaster splint and sling, the elbow was flexed at 90 degrees and the forearm in mid-position. for the first two weeks. A check x-ray was done post- operatively. After two weeks the stitches were removed.

Figure 23: Posterior approach is recommended for open reduction and internal fixation of distal humerus fractures. After exposure of the distal humerus,Steps of open reduction and internal fixation [64].

C. Rehabilitation and Outcome

Early postoperative rehabilitation was recommended to avoid the formation of intra- articular adhesions and peri-articular fibrosis that would make the elbow stiff. Aitken et al in their retrospective study concluded that the most important indicator of end result was the starting point of physiotherapy [65]. After the postoperative pain has subsided in about two days except in two cases which had sever comminuted fractures with suboptimal reduction one of them started elbow motion after one week and the other started after 12 days , active and active assisted range of motion for elbow flexion/ extension and supination/pronation started. This is initially started in horizontal plane to eliminate the effect of gravity. No passive flexion was allowed at this time and up to 6 weeks to allow fracture healing and reduce chances of heterotopic bone formation. Passive gravity assisted extension was commenced at the end of 1 week. With stable fixation splint was discarded after 1 week. Strengthening exercises began at 10 weeks. Active range of motion was regained during the first 2 months. Additional flexion and extension were gained for up to 5 months Works requiring strenuous efforts were avoided for 10 weeks [66].

III. Methods of follow up:

All patients were followed up for at least six months. At the end of the period of follow up, the following data were recorded [56]:

1. Clinically:

• Pain
• Local tenderness and its site
• Signs of infection
• Deformity

a- At the elbow

b- At the site of fracture

• Muscle wasting
• Movements

- Flexion

- Extension

- Pronation

- Supination

• Measurements

- Carrying angle

2. Radiologically:

• Degree of union
• Alignment of the distal and proximal fragments
• Degenerative changes of the elbow
• Signs of infection.

IV. Methods of assessment of the results:

- Maintained joint line

- Good alignment of the fragment

- No signs of infection or non union

- Normal carrying angle

ii) Good:

a) Clinical:

- Activity of daily living

- Slight pain with heavy use

- Arc of flexion 75-110°

-  At least 50% of normal supination and pronation.

b) Radiological:

- Maintained joint line

- Good alignment of the fragments

- Minimal degenerative changes

- No signs of infection or non-union

- Changes of the carrying angle of less than 10 degrees.

2 Unsatisfactory results:

i) Fair:

a) Clinical:

- Activities of daily living

-  Occasional pain with normal use

- Arc of flexion 60-75°

- Loss of more than 50 % of normal supination and pronation

b) Radiological:

- Mild loss of joint line

- Fair alignment

- Moderate degenerative changes

- Changes of in the carrying angle of less than 20 degrees

The results were assessed clinically and radiologically according to the method described by Bickel and Perry as follows [56].

1. Satisfactory results :

i. Excellent;

a) Clinical:

- Heavy work performance

- No pain

- Arc of flexion of at least 110°

- Normal supination and pronation.

b) Radiological:

ii) Poor:

a) Clinically:

The elbow shows any of the followings:

-Used only as a prop

-Constant pain

-greatly restricted motion

b) Radiological:

-Loss of joint line

-Poor alignment

-Marked degenerative changes

- Changes in the carrying angle of than 20 degrees

Statistical Analysis

Data were analyzed using SPSS software package version 18.0 (SPSS, Chicago, IL, USA). Quantitative data was expressed using Range, mean and standard deviation while Qualitative data was expressed in frequency and percent. Qualitative data was analyzed using exact tests such Fisher exact and Monte Carlo to compare different groups. Not normally distributed quantitative data analyzed using Mann Whitney test for comparing two groups. p value was assumed to be significant at 0.05.

a- Mean value ; Where X = the sum of all observations.  n = the number of observations.

b- The standard deviation S.D. = ; Where S(Xi – X)² =the sum of squares of differences of observations from the mean.

c- Fisher’s exact test and Monte Carlo test

It is used whenever the expected frequency in any of the cells of 2´2 table falls below 5. This test involves the calculation of the P value directly, without the use of particular test statistic.

P = a + b!c + d!a + c!b + d!

n!a!b!c!d!

a, b, c, d: are the numbers in each cell n: the total sample size.

!: factorial = successive multiplication of the integers in descending order.

In case of an r x c table the “Monte Carlo”. test was used.

It is used for comparing two group medians based on independent samples (by ranking). To test the hypothesis:

• Ho: Mdx = Mdy

d- Mann-Whitney test

• Ha: Mdx > Mdy
• The test statistic U is:

                                                         n2 (n2 +1)

• U = Uy = Sy -  2
• n2 = number of y values.
• To test:
• Ho: Mdx = Mdy
• Ha: Mdx < Mdy
• The test statistic U is:

                                                              n1 (n1 +1)

• U = Ux = Sx - 2
• n1 = number of x values. Find the critical value C for a one-tailed test
• If U £ C, reject Ho

Where                          S (Xi – X)² =the sum of squares of differences of observations from the mean.

Results

Overall score

In this study 11 patients had excellent results (55%), 7 patients had good results (35 %), one had a fair result (5%), and one patient had a poor result (5%) ( Table 11) (Figure 24).

Table 11: Distribution of the studied cases according to overall score

Figure 24: Distribution of the studied cases according to overall score

The excellent and good results were considered satisfactory and the fair and poor results considered unsatisfactory so in this study, 18 patients (90%) had satisfactory results, while 2 patients (10%) had unsatisfactory results (Table 12)(Figure 25).

Table 12: Distribution of the studied cases according to overall results.

Figure 25: Distribution of the studied   cases according to overall results.

(A) Clinical results:

(1) Range of motion

a. Elbow flexion

In 11 patients the range of motion was 110° or more, in 7 patients it ranged between 75°- 109° and in 2 patients it was less than 75° Thus 45% of patients had limitation of elbow flexion motion (Table 13) (Figure 26).

Table 13: Distribution of the studied cases according to elbow flexion.

Figure 26: Distribution of the studied cases according to elbow flexion.

b. Elbow extension lag

There were 10 patients with elbow extension lag (50%), 2 of them had 5 degrees (10%), 3 patients had 10 degrees (15%) , 4 patients had 15 degrees and 1 had 30 degrees extension lag (5%).(Table 14) (Figure 27).

Table 14: Distribution of the studied cases according to elbow extension lag.

Figure 27: Distribution of the studied cases according to elbow extension lag.

c. Supination and pronation

Regarding supination and pronation, there were 12 patients with range of motion 70-85° (60%), one patient with range of motion 60-69° (5%), and 5 patients with range of motion50- 59°(25%) and 2 patients 30-49° (10%). (Table 15) (Figure 28).Thus 40% had variable degrees of limitation of supination and pronation.