Srinath Kamineni
DEFINITION
Most comminuted elbow fractures have significant associated soft tissue injuries, which are often of equal or greater importance to the bony element.
The key point in determining how to treat acute elbow fractures is to assume that all fractures will be anatomically reduced and fixed.
An acute elbow replacement should be considered only if it is felt that open reduction and internal fixation is unlikely to achieve a predictably good functional outcome.
In the vast majority of cases, elbow replacements for the treatment of acute fractures should be limited to the physiologically elderly patient with low demands and osteoporotic bone stock.
ANATOMY
The bony anatomy of the elbow consists of the distal humerus, proximal ulna, and proximal radius.
Important soft tissue stabilizers include the medial and lateral ligamentous complexes and surrounding musculature, especially the brachialis, common flexor and common extensor masses, and triceps.
The ulnar nerve is tethered to the medial condylar– epicondylar fragment by the cubital tunnel retinaculum distally and the arcade of Struthers proximally.
PATHOGENESIS
Elbow injuries are often the result of direct impact—for example, a direct blow on the elbow during a fall.
Knowing the energy of the fracture is important to gauge the likelihood of associated injuries.
Less energy is required to create a comminuted fracture in elderly and osteoporotic individuals, but muscular injuries of the triceps and brachialis are common, with a subsequent influence on the functional outcome.
The ulnar nerve displaces with the medial fragment. As a consequence, the nerve may kink, leading to a local nerve injury. Nerve lacerations are an uncommon consequence of comminuted distal humeral fractures.
NATURAL HISTORY
Most distal humeral fractures are treatable with either open reduction and internal fixation (ORIF) or nonoperative management. The challenging fracture subgroups are those that involve the articular surfaces and are comminuted.
Many direct and indirect soft tissue complications may ensue, including neurovascular entrapment,2,6 muscle tears leading to myositis ossificans,6,11,15 and soft tissue contracture with joint stiffness.
There is some evidence to suggest that congruently reducing and fixing a comminuted intra-articular distal humeral fracture does not eliminate the risk of posttraumatic arthritis,7 although, where possible, ORIF should remain the primary goal.
PATIENT HISTORY AND PHYSICAL FINDINGS
The physical examination (FIG 1) should be performed gently in the presence of fractures, especially when comminution suggests the possibility of neurovascular injury if the examination is too vigorous.
A complete examination of the elbow should also include evaluation of associated injuries. It should begin away from the elbow, progressing toward it.
The following associated injuries should be ruled out.
Distal radial and scaphoid fractures: Since the most common mechanism of injury is a fall onto an outstretched hand, the energy transfer of the fall begins in the extended wrist, through the distal radius and scaphoid. Direct palpation of the distal radius should be done and anatomic snuffbox tenderness should be elicited. Palpation of the scaphoid tubercle and ulnar and radial deviation of the wrist may also identify a scaphoid injury.
Distal radioulnar joint disruption: Ballottement of the ulnar head should be done in the volar and dorsal directions, in pronation and supination. A disrupted joint is often painful with such ballottement, and the ulnar head may be prominent with the forearm in pronation.
Fracture extension beyond the elbow: The examiner should palpate the ulna shaft, along its subcutaneous border, from the wrist to the olecranon.
Interosseous membrane injury: Palpating the interval between the bones of the forearm is not a sensitive examination but can raise suspicion for an Essex-Lopresti injury,
FIG 1 • Typical appearance of an elbow with an underlying fracture with extensive swelling and bruising.
FIG 2 • Standard AP and lateral plain radiographs.
leading to further imaging. If an interosseous membrane disruption is present, this will influence the type of implant used for elbow replacement (one with a radial head replacement), but the pathology is not commonly described.
IMAGING AND DIAGNOSTIC STUDIES
Plain radiographs, including anteroposterior (AP) and lateral views (FIG 2) of the elbow and both wrists, should be obtained. The elbow view may have to be taken in a protective splint or plaster back-slab for patient comfort.
Elbow radiographs will allow initial assessment of the degree of comminution and may indicate the presence of decreased bone mineral density.
Bilateral wrist views will indicate the presence of an axial (interosseous membrane) injury if the ulnar head is in positive variance compared to the contralateral uninjured wrist.
Plain tomograms are of use in improving the understanding of the fracture configuration, but an alternative would be a computed tomography (CT) scan. With the latter the surgeon can view a three-dimensional reconstruction, which is a useful surgical planning tool.
If there is evidence on physical examination of a neurologic injury, it is prudent to document its extent with a carefully performed neurologic examination.
DIFFERENTIAL DIAGNOSIS
Nonunion
Ligamentous disruption
Fracture-dislocation
NONOPERATIVE MANAGEMENT
The “bag-of-bones” technique is a nonoperative method of treatment described by Eastwood that encourages the compressive molding of the comminuted distal humeral fracture fragments.
Subsequent rehabilitation with collar and cuff support achieves substandard but acceptable results only in the elderly and debilitated group of patients who have almost no demand on elbow function.
This type of treatment does not achieve acceptable results with respect to stability and strength in younger patients.
SURGICAL MANAGEMENT
Open Reduction and Internal Fixation
ORIF has been widely documented for comminuted fractures of the distal humerus.
Some reported series demonstrate good results with fixation of such challenging fractures, with better results predominantly in the younger age groups.12,16 Rarely are good results achieved in the elderly, osteoporotic group.7
Many series report less-than-satisfactory outcomes in the elderly treated by operative fixation.12
A direct comparison of internal fixation to primary total elbow replacement in the elderly osteoporotic group revealed that replacement produced no poor results and no need for revision surgery at 2 years of follow-up. The internal fixation group produced three poor results requiring revision to a total elbow replacement.4
Elbow Arthroplasty
When a distal humerus fracture is not reconstructable, arthroplasty becomes a valid treatment option.
Elbow replacement following a failed attempt at fixation has proven to have a significantly worse outcome than if the arthroplasty was performed initially.3
There are a number of studies that support the concept of an acute total elbow arthroplasty in select patients with comminuted fractures of the distal humerus.1,3,9
The more traditional form of replacement for the elderly and low-demand population with an unreconstructable distal humerus fracture is the total elbow arthroplasty.
A more recent innovation has been the replacement of the distal humerus (hemiarthroplasty) to preserve an intact ulna and radial head.13 This procedure is not FDA approved and so should be considered experimental and not for general consideration, especially since the elbow joint is variable and highly congruent in its topography, which differs from many of the standard implants used for acute fractures.
Indications and Contraindications
Indications for acute total elbow arthroplast.
Comminuted, unreconstructable distal humerus fracture
Physiologically elderly patient
Low-demand patient
Indications for acute elbow hemiarthroplast.
Unreconstructable distal humeral fracture (C3)
Unreconstructable combined fractures of capitellum and trochlea
Very low bicondylar T fracture of distal humeru.
Young patient
Active patient
Repairable or intact collateral ligaments (may require reconstruction of the medial and lateral supracondylar columns)
Repairable or intact radial head
Absolute contraindications for acute joint replacemen.
Infection (overt)
Lack of soft tissue coverage (skin, muscle)
Relative contraindications for acute joint replacemen.
Infection in distant body part
Contaminated wound
Neurologic injury involving the elbow flexors
Preoperative Planning
Standard radiographs should be obtained (AP and lateral).
If doubt exists regarding the ability to anatomically repair the fracture, then a CT scan should be requested to assess the degree of comminution and the fracture line orientation.
An assessment of humeral shaft bone loss is important in planning the implant design that might be considered. If the degree of loss is greater than the articular condylar fragments, an implant that has the ability to restore humeral length will be more appropriate. If an unreconstructable fracture of the humeral articular surfaces without humeral shaft bone loss is encountered, an implant with the ability to resurface the articular surfaces as a hemiarthroplasty or a resurfacing ulnotrochlear replacement can be considered, but the former implantation technique should be regarded as an off-label and experimental procedure.
Humeral shaft length loss of 2 cm can be tolerated and standard implants used.
Humeral shaft length loss of greater than 2 cm can be restored with implant designs with anterior flanges, especially those with extended flanges that allow restoration of humeral length.
The surgeon should assess the intramedullary canal dimensions of the humerus and ulna. This will help to plan the requirement of extra-small diameter.
Neurovascular status of the limb should be fully assessed and documented in the clinical notes.
Patient Positioning
Two methods of patient positioning can be used, depending on surgeon comfort and the access required:
Supine: The arm is draped for maximum maneuverability. During the procedure the arm is supported on a large rolled towel placed on the patient's upper thorax, carefully avoiding the endotracheal tube, stabilized by an assistant. In this position the surgeon stands on the side of the patient's injured limb (FIG 3A).
Lateral decubitus: The arm is positioned on an arm support, thereby minimizing the need for an assistant, but this set-up is less maneuverable. In this position the surgeon stands on the opposite side of the patient's injured limb (FIG 3B).
Surgical Approach
Two main surgical approaches are useful for acute total elbow arthroplasty:
Triceps-splitting approach
Bryan-Morrey approach
The triceps should be carefully managed in either approach, and it often has a thin tendon, especially in older patients and those with rheumatoid arthritis. The triceps tendon should be dissected from the olecranon with a small curved scalpel blade, maintained perpendicular to the interface between the tendon and bone.
FIG 3 • A. Patient positioned in a supine position. The elbow is isolated and placed on a roll of towel placed on the patient's chest, and stabilized by an assistant. The surgeon must take care to avoid the neck and anesthetic equipment. B. Patient positioned in a lateral decubitus position with the elbow draped over an arm support.
TECHNIQUES
INCISION AND DISSECTION
Make a midline longitudinal skin incision (TECH FIG 1A), with a gentle curve to avoid the olecranon weight-bearing prominence. Extend the incision 5 cm distal to and proximal to the prominence of the olecranon tip.
Develop the full-thickness medial and lateral skin flaps (TECH FIG 1B) and define the medial and lateral borders of the triceps (TECH FIG 1C,D).
At the medial border, define and partially neurolyse the ulnar nerve, and mark and handle it with a tied vessel loop (without an attached hemostat, since its constant weight may cause inadvertent nerve injury) (TECH FIG 1E).
With the nerve visualized and handled to safety, remain in the medial gutter to extend the dissection distally to define the medial fracture fragment. Transect the medial collateral ligament in its entirety, and remove all soft tissue from this bony fragment and remove the latter (TECH FIG 1F).
TECH FIG 1 • A. Skin incision is posterior longitudinal, with or without a small diversion to avoid the “point” of the olecranon. B. Raising the skin should aim to maintain the full thickness of the flaps by using the “flat knife” technique. C. The medial and lateral borders of the triceps are defined (arrows). D. This patient had an anconeus epitrochlearis (star) in relation to the ulna nerve (UN). E. A vessel loop is used to maneuver the nerve without an attached clip. F. The medial fragment of the fracture is removed once all the soft tissues are released from it, and the nerve is gently retracted to ensure tension-free removal.
TRICEPS MANAGEMENT
Triceps Preserving
With the ulnar nerve gently medially retracted, use a periosteal elevator to define the plane between the triceps and the posterior humerus, from the medial to the lateral border, exiting posterior to the lateral intermuscular septum. Use this elevator to lift the triceps, with blunt dissection, by sliding the shaft of the elevator proximal and distal in the interface (TECH FIG 2A).
Develop the lateral triceps–lateral intermuscular septum margin and resect the lateral fracture fragments, having firstly cleared them of soft tissue attachments (TECH FIG 2B).
While in the lateral corridor, visualize the radial head and resect sufficient head to prevent abutment on the prosthesis.
From the lateral margin of the humeral shaft, raise the brachialis from 2 to 3 cm of the anterior surface.
Modified Bryan-Morrey Approach
Preserving the integrity of the triceps insertion makes component insertion more difficult. An alternative approach for managing the triceps is to reflect it from the tip of the olecranon from medial to lateral, thereby improving exposure (TECH FIG 3).
Define the medial triceps border and dissect the ulna nerve free from its connections, while protecting it in a vessel loop. The nerve is transposed into a subcutaneous pocket.
The medial triceps is dissected to its ulna attachment. Release the triceps from the medial condylar fragments and transect the medial collateral ligament. Free the medial fragments from soft tissue attachments and remove the medial fragments between the triceps and a gently anteriorly retracted ulnar nerve.
TECH FIG 2 • A. A periosteal elevator is introduced between the triceps and the humeral shaft and the two structures are separated by sliding the elevator proximally and then distally to the level of the triceps insertion. B.The lateral corridor is defined and lateral fragments are removed.
Develop the interval between the anconeus and flexor carpi ulnaris along the subcutaneous border of the ulna.
The triceps tendon is sharply elevated from the olecranon, in continuity with the anconeus, and subluxed laterally. Take care to release the Sharpey fibers adjacent to the bone in order to retain the flap thickness. Further access is afforded by raising the anconeus from its ulnar attachment while maintaining its attachment distally.
As the triceps is reflected laterally, the lateral condylar fragments are identified and removed by releasing the lateral collateral ligament and common extensor tendon.
TECH FIG 3 • A. The triceps is split through its central tendon, in line with the fibers. The tendinous portion is dissected from the olecranon to gain access to the ulna. B,C. To dissect the Sharpey fibers off the ulna, the surgeon uses the scalpel parallel to the ulna surface and maintains the release directly adjacent to the bone. D. Comminuted distal humeral fracture in an osteoporotic elderly woman, with CT imaging confirming significant articular comminution. This is the view through the triceps split.
BONE PREPARATION
Identify the olecranon fossa (if any part of it still exists). This landmark is the seating point for the base of the anterior flange of the Coonrad-Morrey humeral component (TECH FIG 4A). If the olecranon fossa is not present owing to a greater degree of comminution, an extended-flange humeral component can be used.
Release the anterior capsule and any soft tissue from the anterior surface of the distal humerus. This provides a site for the anterior humeral bone graft.
The posterior flat surface of the humerus is identified since this plane approximates the axis of rotation of the distal humerus (TECH FIG 4B). Humeral canal preparation is completed with the canal broaches provided with the implant system being used.
The ulnar canal preparation commences with removal of the tip of the olecranon. The intramedullary canal is entered at the base of the coronoid (TECH FIG 4C,D).
The entry point is enlarged up toward the coronoid with a burr to allow easier component insertion without cortical abutment, which leads to malalignment (TECH FIG 4E).
TECH FIG 4 • A. The humeral component entry point, the apex of the olecranon fossa, is identified and humeral canal preparation is commenced by opening the canal with a bone nibbler or burr. B. The posterior flat surface of the humeral shaft is identified and the component is aligned. C,D. Ulnar canal preparation is commenced by opening the canal at the base of the coronoid process with a drill or burr. E.The trajectory of the ulnar component (black ring) is prepared by rasping the entry track posteriorly into the ulna with a rasp or bone nibbler (gray crescent). F,G. The tip of the coronoid should be resected sufficiently to prevent abutment on the humeral flange during full flexion. Also shown are the resections of the olecranon and the entry point for the ulnar stem insertion. H. The partially resected radial head is used as a bone graft for incorporation behind the humeral flange.
During intramedullary preparation, the broaches must parallel the subcutaneous border of the ulna. This ensures that the track of insertion of the ulna parallels the intramedullary canal.
The tip of the coronoid is removed to avoid impingement during terminal flexion (TECH FIG 4F,G).
The radial head does not need to be resected if there is no disease of the proximal radioulnar joint (TECH FIG 4H).
IMPLANT INSERTION AND TENSIONING
With the canal preparation completed (TECH FIG 5A), including pulse lavage of the medullary canals and cement restrictor placement, implant insertion can commence (TECH FIG 5B,C).
Humeral insertion
When bone loss is at or below the level of the olecranon fossa, standard humeral insertion can occur. If bone loss occurs above the olecranon fossa (greater than 2 cm), then humeral length must be restored.
Prepare a wedge-shaped bone “cookie” for placement behind the humeral flange.
Inject antibiotic cement into the humerus.
When inserting the humeral component, place the bone graft behind the anterior flange. Because the humeral condyles have been resected, the implant can be completely seated and coupled once the cement has hardened.
TECH FIG 5 • A. The prepared bony surfaces, with the fracture fragments removed, and just before implantation. B. The linked Coonrad-Morrey replacement is cemented and linked in situ. C. If in terminal extension there is abutment of the tip of the olecranon on the implant, the surgeon resects the olecranon tip (OT) but should not approach the triceps insertion footprint.
Maintain the component orientation relative to the posterior flat surface of the distal humerus.
Seat the component and flange until the flange is completely engaged with the anterior cortex.
Ulnar component insertio.
Inject antibiotic cement into the ulnar canal.
The ulnar component is inserted such that the axis of rotation is recreated and the implant is perpendicular to the dorsal flat surface of the olecranon.
TRICEPS REATTACHMENT
The triceps is reattached using a nonabsorbable suture in a running locking mode (eg, running Krakow stitch) to achieve predictable purchase (TECH FIG 6A,B).
Avoid capturing large amounts of triceps muscle fibers within the locking loops.
The triceps tendon should be reattached to the flat of the olecranon process, not to the tip (TECH FIG 6C,D). Pass the sutures through bone tunnels (oblique crossing) that begin on the periphery of the flat reattachment area of the olecranon (TECH FIG 6E).
Avoid tying the sutures directly over the midline of the proximal ulna, which is a source of painful symptoms and may require knot removal. Place the knot under the anconeus.
When tensioning the triceps at reattachment, place the elbow at 30 to 45 degrees of flexion while tying the knot.
Use a separate absorbable suture to “cinch” the triceps footprint onto the reattachment area (TECH FIG 6F).
TECH FIG 6 • A,B. A running locking stitch is used to improve triceps purchase when reattaching the muscle to the ulna. A. An example of a running locking stitch on either side of the split tendon. B. A locking stitch that locks both sides of the split together with one continuous locking suture. It is then reinforced with a reversed across-split locking suture. C,D. The triceps footprint to which reattachment should be attempted is predominantly on the flat part of the ulna or olecranon process, and not the tip, which is resected to prevent posterior abutment. E. Drill holes (1.5 to 2 mm) are oriented in a crossing fashion to secure the triceps to the footprint area. F. A separate “cinch” suture is used to increase the security and the area of contact between the triceps and the ulna, thereby improving healing potential.
WOUND CLOSURE
The ulnar nerve is transposed into an anterior subcutaneous location.
Reapproximate the triceps to the flexor and extensor masses with absorbable suture. Do not overtighten this repair, as it will restrict motion.
The use of a subcutaneous drain is a matter of surgeon preference. However, there is no literature demonstrating the efficacy of a postoperative drain in preventing hematoma.
PEARLS AND PITFALLS
POSTOPERATIVE CARE
A volar plaster or thermoplastic splint is used to maintain the elbow in full extension for the first several days. This avoids tension on the incision and on the triceps reattachment.
The arm is elevated on pillows or with a Bradford sling overnight to prevent edema.
Nonsteroidal anti-inflammatories are avoided because of their detrimental effects on tissue healing (bone to tendon and bone to bone).
On the second day after surgery the dressing is removed and the compliant patient should commence gentle active antigravity flexion, with passive gravity-assisted extension.
Graduated and targeted motion is prescribed, with greater than 90 degrees of elbow flexion attempted after 5 weeks. This allows sufficient time for the triceps to adhere and heal (incompletely) to the ulna. Aggressive flexion too early may result in triceps avulsion or pull-out. Triceps antigravity exercises can commence after 5 weeks.
Always, at each patient interaction, the surgeon should reiterate the restrictions of use with an elbow arthroplasty: limited internal (varus) and external (valgus) rotatory torques, 2-pound repetitive and 10-pound single-event lifting.
COMPLICATIONS
Triceps avulsion
Stiffnes.
Overlengthened implantation
Overtensioned triceps reattachment
Overzealous closure of triceps to flexor–extensor compartments
Inadequate soft tissue release
Impingemen.
Radial head on humeral component (distal yolk)
Coronoid on humeral component (anterior yolk)
Olecranon process on posterior humerus
Deep venous thrombosis
Infection
Periprosthetic fractur.
Osteoporotic bone
Stem–canal mismatched sizes
Stem–canal mismatched curvature
Inadequate opening for ulna component at coronoid base
Ulna nerve neuropathy or injury
OUTCOMES
Cobb and Morrey1 reported 15 excellent and 5 good results, with one patient with inadequate data, in a cohort of patients with acute distal humeral fractures (average age 72 years) at 3.3 years of follow-up.
Ray et al14 reported 5 excellent and 2 good functional results in a group of patients with an average age of 81 years at 2 to 4 years of follow-up.
Gambirasio et al5 reported excellent functional results in a cohort of 10 elderly patients with osteoporotic intra-articular fractures.
Frankle et al4 compared the outcomes of patients over age 65 with comminuted intra-articular distal humeral fractures treated with ORIF versus acute total elbow replacements. The ORIF group had 8 excellent results, 12 good results, 1 fair result, and 3 poor results, with 3 patients requiring conversion to elbow replacement. All 12 acute primary elbow replacements achieved excellent (n = 11) or good (n = 1) results.
Kamineni and Morrey8 reported an average Mayo Elbow Performance Score (MEPS) of 93/100 in a series of 49 acute distal humeral fractures (average patient age 67 years) at 7 years of follow-up. The average arc of motion was 107 degrees.
Lee et al10 reported seven acute elbow replacements for distal humeral fractures in patients with an average age of 73 years. The average arc of motion was 89 degrees and the average MEPS was 94/100 at an average follow-up of 25 months.
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