NONSURGICAL MANAGEMENT

Nonoperative options of soft sling or plaster cast are traditionally used in cases in which reconstruction is not an option, by virtue of patient or surgical factors. Although widely propagated as an acceptable methodology, it is documented that such a strategy does not yield consistent pain relief or consistent joint stability, with unsatisfactory results in approximately 40% of cases.¹⁷

FRACTURE FIXATION

A prerequisite for reconstruction is to fix the fracture fragments with some form of rigid fixation construct that then synchronously allows stable fixation and joint motion. However, there are three main fracture factors that adversely affect the ability to reconstruct the distal humeral fracture: (1) Comminution: If the distal humeral articular surface is significantly comminuted (Fig. 56-1A), not only is it not possible to fix all the bony fragments, but the cartilage surface would also have undergone considerable injury, leading to a suboptimal bearing surface. (2) Size of fracture fragments: It is straightforward to understand the issues with a large number of small bony fragments, with a significant number made up of small osteochondral fragments. Additionally a transcondylar or very low supracondylar fracture also poses the same problem of the ability to hold the fracture sufficiently rigidly while allowing joint motion (see Fig. 56-1B). (3) Quality of bone stock: Good quality young bone stock allows better fixation than does osteopenic/osteoporotic older bone.^26,31 In a young population with an average age of 35 years, distal humeral articular surface fractures treated with internal fixation achieved good and sustainable results, although 40% required secondary procedures: an average flexion arc of 106 degrees, average foream rotational arc of 165 degrees, and a Mayo Elbow Performance Score (MEPS) of 91.² A choronologically older group of patients with distal humeral fracture fixation, but without objective proof of osteoporosis, resulted in a 75% good/excellent range of motion and 80% satisfaction,¹⁵ although other studies of the older age group found less satisfactory results.²⁷ Helfet et al⁸ demonstrated that despite good surgical technique and adequate internal fixation, 2-10% of such patients develop non-unions. Furthermore, if early motion is sacrificed, a compromise made for the quality of bone stock, the prediction is a better rate of union with a stiff joint. Pajarinen and Bjorkenheim²⁶ correlated that immobilization greater than 3 weeks was a poor prognostic factor, after open reduction and internal fixation (ORIF), for achieving a good functional score. Thereby, when the principle of rigid internal fixation with early joint mobilization cannot be adhered to, then fracture fixation, joint immobilization to union, and a secondary motion gaining procedure may have to be considered.

FIGURE 56-1 A, Distal humeral fracture showing, with a radiograph, computed tomography scan, and intraoperative findings, the extent of comminution and osteopenic state of the bone. Low osteoporotic transcondylar fractures (B, C) have little bone of quality for fixation. This is an example of such a fracture that is malrotated when immobilized in a plaster cast (D, E).

ACUTE TOTAL ELBOW ARTHROPLASTY

An alternative strategy that has gained a wider acceptance is the acute total elbow replacement, when the fracture is judged to be unreconstructable or reconstructable without the predictability desired to allow early motion. However, the replacement of an unreconstructable fracture involving a joint is not a new concept. Hip⁷ and shoulder,^6,25 and less commonly knee,^7,14 surgeons, have an established body of literature regarding the relevance and successful outcomes of this concept.

Total elbow replacements have been proven effective in the treatment of distal humeral nonunions,²² post-traumatic arthritis,^16,24,30 rheumatoid arthritis,²³ and chronic fracture dislocations.²⁰ More recently, a growing literature appears to be favorable regarding this concept in the treatment of the difficult-to-reconstruct distal humeral fracture in the older age group of patients (Table 56-1). The first large series, which was reported by Cobb and Morrey,¹ was a retrospective study of 21 distal humeral fractures in patients with an average age of 72 years. Ten of the cases had pre-existing rheumatoid arthritis, and the follow-up period was an average of 3.3 years (Table 56-2). The outcomes, based on the MEPS, were 15 excellent and five good results, with inadequate data in one case. Only one patient required revision arthroplasty due to a fractured ulna component (Table 56-3).

TABLE 56-1 Indications and Contraindications for Acute Elbow Arthroplasty

OPERATING ROOM PREPARATION

The relevant imaging of the fracture should be displayed for the operating surgeon to reference during the procedure. A torniquet is positioned on the upper arm, and its size should allow surgical access to a minimum of 10 centimeters proximal to the olecranon process for distal humeral fractures (Fig. 56-2). The torniquet should be inflated only when the whole limb is prepared and draped after the limb is elevated for 5 minutes.

FIGURE 56-2 The arm is cleaned and prepared with a tourniquet placed to allow access to a minimum of 10 cm proximal to the olecranon process. Identify and mark all the bony points and the ulna nerve.

PATIENT POSITIONING

The patient is placed supine on the operating table with no other supports to restrict arm motion. The arm is placed across the chest, and rested on a bolster or roll of towels. The towel roll should be sterile in order to reposition during different parts of the procedure (Fig. 56-3).

FIGURE 56-3 Supine positioning of the patient allows the arm to be draped over a towel roll, which, in turn, allows easy maneuvering of the arm during the procedure, with little restriction to access.

SKIN INCISION

A straight skin incision 5 cm distal to and 10 cm proximal to the olecranon tip is employed (Fig. 56-4). The incision should be just medial or lateral to the tip of the olecranon in order to avoid the discomfort of a scar on a weight-bearing part of the elbow, when resting on the arm, with a potential for wound breakdown. Deepen the incision to define the superficial surface of the triceps central tendon, without breaching its surface (Fig. 56-5).

FIGURE 56-4 The initial skin incision is 5 cm distal to and up to 10 cm proximal to the olecranon process.

FIGURE 56-5 The skin incision is deepened to the level of the triceps central tendon without breaching its surface.

APPROACH

A full-thickness skin flap should be first raised up to the level of the border of the triceps muscle belly, which can often be achieved with simple finger dissection (Fig. 56-6). A method of raising the skin flaps, which are more adherent, is the flat blade technique, in which the blade is pressed against the deeper plane but angled at 45 degrees toward the superficial plane (Fig. 56-7). Because bruising and blood clots may obscure normal anatomy, at this point, the ulna nerve should be palpated gently by digital probing. The nerve should be dissected free of the cubital tunnel and released up to the first motor branch, freeing it from the medial epicondyle fragment. A vessel loop should be placed around the nerve, knotted loosely to allow easy control without an attached artery clip (Fig. 56-8). Once the nerve is protected, the remainder of the medial skin flap can be raised to allow access to the anterior aspect of the medial fragment. Once the fragments are freed, they can be removed either posterior or anterior to the nerve, depending on which situation places the nerve under least tension (Fig. 56-9). The lateral full-thickness skin flap should also be raised. Continuing the dissection distal to the epicondyle allows the anconeus–extensor carpi ulnaris interval to be identified, which will be the continuation for the lateral triceps border mobilization (Fig. 56-10). The lateral epicondyle is then enucleated of all soft-tissue attachments, and then removed through the lateral exposure (Fig. 56-11). When the fracture is a low supracondylar or transcondylar configuration, the fragment may be more easily removed, once freed medially and laterally, through the TS approach (Fig. 56-12).

FIGURE 56-6 In the trauma setting, raising a skin flap can often be performed with simple finger dissection, which also allows a tactile assessment of the underlying fracture.

FIGURE 56-7 Raising the medial and lateral skin flaps can be performed with a flat blade technique, where the planes are adherent.

FIGURE 56-8 Once the medial border of the triceps muscle belly has been defined, palpate and dissect the ulnar nerve. Release it from the cubital tunnel, and control the position of the nerve during the remainder of the procedure with a vessel loop, without a clip, but simply knotted loosely.

FIGURE 56-9 A, Brian-Morrey approach. The medial fragment is enucleated of its attachments, notably the flexor-pronator mass and medial collateral ligament. B, The medial triceps is elevated and the medial fragments removed. C, Triceps split approach. The ulnar nerve, having been dissected and protected, the medial fragment is enucleated and removed, with assistance of a pushing probe through the triceps split. ME, medial epicondyle. D, The triceps is freed from the underlying humerus by sliding a periosteal elevator in a proximal to distal direction.

FIGURE 56-10 The anconeus–extensor carpi ulnaris interval is often identified by a fat streak that exits between the two muscles. Extending this interval proximally will allow the lateral border of the triceps to be mobilized for lateral fragment and radial head removal.

FIGURE 56-11 The lateral fragment is enucleated from its extensor mass and lateral collateral ligament attachments, and can be removed. A, Comminuted fragments are easily removed from the lateral approach. B, Lateral dissection. C, If the fracture fragment is large, then enucleation is the option via the lateral approach, in preparation for central removal of the fragment.

FIGURE 56-12 When the fracture fragment is a low transcondylar, or requires a larger dissection through the medial or lateral dissection, it can be easily removed through the central triceps spilt approach.

With the modified B-M approach, the forearm is now rotated toward the head of the patient in order to better expose the implantation surfaces of the humerus and ulna. The triceps, with the ulna nerve, is displaced medially. In order to improve exposure, the triceps is elevated from the medial and lateral aspects of the ulna but not from the posterior aspect. Using a triceps-sparing approach, a split is made from the apex of the olecranon, in line with the central triceps tendon fibers, for 5 to 7 cm proximally. The triceps is elevated from the posterior olecranon, sufficient to allow ulna preparation and implantation. The amount of triceps generally required to be elevated, by Sharpey fiber dissection, is 1 to 2 cm², but no elevation is required from the medial and lateral aspects of the ulna. The humerus is then exposed through the triceps split, as is the olecranon tip (Fig. 56-13).

FIGURE 56-13 The triceps split approach commences at the apex of the olecranon process and splits the triceps, in line with its central tendon fibers between 5 to 7 cm proximally. The triceps footprint is elevated off the olecranon posteriorly only, with the medial and lateral ulna triceps insertions remaining intact.

Humeral Preparation

No additional bony cuts are usually required once the fracture fragments are removed, with no real detriment to forearm/wrist power expected (Fig. 56-14).¹⁹ The canal is simply rasped to the correct size, and the flange of the Coonrad-Morrey humeral component should seat at the level of the coronoid fossa apex. A 6-inch humeral stem is the optimal length, but this also has to take into account the possibility of a pre-existing shoulder prosthesis. Additionally, if the patient has pre-existing shoulder pathology, with the possibility of requiring a prosthesis in the future, it is prudent to implant a 4-inch humeral stem, If the humeral fracture does not allow adequate seating of a trial implant, following canal preparation, resect additional bone.

FIGURE 56-14 Following fracture fragment removal, no bony cuts are usually necessary. The humeral canal preparation will commence by accessing the humeral intramedullary canal with a rongeur at the apex of the olecranon fossa (triangle). T, triceps insertion.

Ulna Preparation

In the B-M approach, adequate exposure of the ulna is achieved by dissecting and protecting the ulnar nerve in an anteriorly displaced position and then by elevating the medial 25% of the triceps attachment. The forearm is rotated to help in exposing the medial olecranon and coronoid, and the tip of the olecranon is resected. In the TS approach, the posterior flat area of the olecranon is exposed without elevating the medial and lateral aspects of the triceps insertion. The tip of the olecranon is resected, and a clear view is achieved of the base of the coronoid and radial head when the elbow is hyperflexed (Fig. 56-15). The tip of the coronoid is also commonly resected to avoid anterior flange impingement in flexed positions (Fig. 56-16).

FIGURE 56-15 The humeral shaft is prepared in the standard manner, with rasps, and the radial head is resected to prevent abutment with the humeral yolk. With the olecranon tip resected, and the elbow hyperflexed, the coronoid base is easily accessible for ulna canal preparation.

FIGURE 56-16 Once the humerus and ulna are fully prepared, the ulna and humeral canal trajectory of insertion should be readily accessible; this is an example of the triceps split approach. (1) Triceps insertions site of olecranon, (2) resected olecranon tip surface, (3) ulna medullary canal, (4) humeral medullary canal, and (5) resected distal humeral surface.

A high-speed olive-tipped burr is used to open the base of the coronoid process (Fig. 56-17). Extreme care should be exercised during this procedure to avoid the inadvertent injury to the ulna nerve. Tip: Hold the medial and lateral borders of the ulna between two fingers, which automatically displaces and protects the ulna nerve. When the coronoid base is sufficiently opened, ulna shaft rasping can begin. When rasping the canal, always orient the rasp parallel to the flat spot of the ulna; with the Coonrad-Morrey system, the rasp handle will be perpendicular to the flat spot. Because there is a risk of penetrating the cortices during rasping, a useful habit is to grasp or palpate the ulnar shaft with the nonrasping hand to help orient the direction of rasping in line with the rasp/burr (see Fig. 56-17).

FIGURE 56-17 The coronoid base is opened with a burr, and once the ulna canal is accessible for rasping, the burr is used to fashion a furrow, exiting the olecranon posteriorly.

Trial Implantation

In the B-M approach, both trial components are inserted and then the components are reduced. Often, gentle distraction of the joint is prudent to avoid levering the components during the reduction. With the TS approach, the humeral component is inserted first and then, with the elbow flexed to 90 degrees, the ulnar component is inserted through the yolk of the humeral component, without the need for a reduction maneuver. The ulnar component center of rotation should coincide with the center of the greater sigmoid notch of the ulna. Once the components are inserted to the correct depth, the elbow should be examined through a full range of extension and flexion. If there is any suggestion that there is bony abutment of the olecranon process posteriorly or coronoid process anteriorly, these should be sufficiently trimmed. Any radial head abutment can also be visualized and an appropriate depth of radial head can be resected. The bone resected from the radius is useful for creating the posterior flange bone graft, and should be stored in a damp swab until humeral component insertion. Once the trials are satisfactory, they are removed and the bony canals are pulse lavaged, a cement restrictor is inserted into the humeral canal to the correct level, and the canal kept dry until cementation commences.

In situations in which distal humeral bone loss is greater than that would allow standard seating of the standard flange design, an extended flange may be used to regain humeral length (Fig. 56-18). However, triceps power is well maintained with humeral loss of up to 2 cm.⁹

FIGURE 56-18 When bone loss is encountered, of distal humeral length, 2 cm of loss can be tolerated. With greater losses, length can be restored with a longer stem and a longer anterior flange.

Implant Insertion

A single mix of polymethylmethacylate cement with 1 g of vancomycin is vacuum mixed. Good cementing technique is of great importance.³ The cement is loaded into a cement gun, the nozzle of which was pretrimmed to 1 cm beyond the humeral stem length (Fig. 56-19), and the cement inserted into the humerus followed by the ulna. As the humerus is inserted, the bone graft, which should be gently wedge shaped (2 mm thick at the distal and 4 mm at the proximal ends), should be held on the anterior humeral cortex as the flange engages this region. With the B-M approach, the ulna is inserted first (Fig. 56-20), followed by the humerus. Once inserted to the correct depth, a reduction maneuver is performed and the locking pins are articulated. With the TS approach, the humeral component is inserted first, followed by the ulnar component through the yolk. Once the articulating pin is secure, the humeral component is finally tapped into its final position, and the elbow is extended and maintained in this position until the cement is cured (Fig. 56-21). Before setting, excess cement should be diligently removed to avoid cement particles in the articulation.

FIGURE 56-19 The cementation of the humeral and ulna canals should be approximately 1 cm distal to the prosthesis tip.

FIGURE 56-20 The depth of ulna insertion should not exceed the center of the projected center of the greater sigmoid notch of the ulna.

FIGURE 56-21 Following final implantation, the implant balance should be assessed by simply supporting the forearm at 90 degrees of elbow flexion (A). The prosthesis should be balanced with a parallel gap between the yolk and liner on both sides (B). If the implant is imbalanced (C), closure of the soft tissues can be modified, with differential tension, in order to help improve the balance.

Wound Closure

The B-M approach closure consists of anteriorly isolating the ulnar nerve in the plane between the flexor muscle mass and the skin. Care to adequately resect the medial intermuscular septum should be taken, and the pocket is created with a Vicryl suture across the plane, making sure that the ulna nerve is free to mobilize during elbow motion. The flexor mass is then sutured to the medial triceps and the lateral mass to the lateral triceps margin (Fig. 56-22). With the TS approach, No. 2 ethibond is used to close the triceps tendon split with a running locking stitch, which then secures this central triceps to the olecranon through bone tunnels. The elbow is dressed with a nonadherent dressing, and a volar thermoplastic removable splint in full extension.

FIGURE 56-22 Muscle closure. A, With the Brian-Morrey approach, the flexor and extensor masses are reattached to the triceps. B, If the muscle belly is of good quality, the triceps split can be simply closed with a continuous crossed suture, into olecranon cruciate bone tunnels. C, If the muscle belly is of poorer quality, a running locking stitch offers greater security.

Postoperative Management

The arm is elevated for 24 hours, and the patient is typically discharged on the second or third postoperative day following evaluation of the patient’s radiographs (Fig. 56-23). A night-time volar splint is used for the first 4 weeks to encourage the maintainence of full extension. Active elbow flexion is commenced with gravity extension only for the first 4 weeks. Routine physical therapy is not needed. Normal use of the elbow can be encouraged at week 4 after operation (Fig. 56-24).

FIGURE 56-23 Postoperative radiographs at 1 week (A, anteroposterior [AP]; B, lateral) and 5 years (C, AP; D, lateral) after an acute total elbow replacement. The latter views demonstrate heterotopic ossification but no evidence of implant loosening or bushing wear. Note the well-maintained balance of the implant.

FIGURE 56-24 Postoperative motion following a triceps split approach, including an arc of flexion greater than 100 degrees and active antigravity power with overhead extension.