AAOS Comprehensive Orthopaedic Review

Section 6 - Trauma

Chapter 52. Fractures of the Humeral Shaft and Distal Humerus

I. Fractures of the Humeral Shaft

A. Epidemiology


1. Humerus fractures account for 3% of all fractures and most commonly occur in the middle third of the bone.


2. They exhibit a bimodal age distribution with peak incidence in the third decade of life for males and the seventh decade for females.


3. In the younger age group, high-energy trauma is more frequently the cause. Lower energy mechanisms are more common in the elderly.


B. Anatomy


1. The anatomy of the humerus varies throughout its length (

Figure 1).


a. The shaft is generally cylindrical and provides origin and insertion points for the pectoralis, deltoid, biceps, coracobrachialis, brachialis, and triceps.


b. These origins and insertions determine the displacement of the major fracture fragments.


c. Distally, the humerus becomes triangular, and its intramedullary canal terminates approximately 2 to 3 cm proximal to the olecranon fossa.


d. Medial and lateral septae delineate the posterior and anterior compartments of the arm.


2. The main neurovascular structures of the arm and forearm traverse the soft tissues overlying the humerus. Posteriorly, the spiral groove houses the radial nerve. Its location is approximately 14 cm proximal to the lateral-distal articular surface and 20 cm proximal to the medial-distal articular surface.


C. Surgical approaches


1. Anterolateral approach—May be considered for proximal third to middle third shaft fractures.


a. The radial nerve can be identified between the brachialis and brachioradialis and traced proximally.


b. Alternatively, for more proximal fractures, the brachialis (innervated by the radial and musculocutaneous nerves) can be split to spare its innervation and protect the radial nerve during retraction.


2. Posterior approach—Effective for most of the humerus, from the deltoid insertion and distally. The deltoid prevents extension of this approach proximally to the shoulder.


[Figure 1. The shaft of the humerus, showing the division into three surfaces.]

a. The radial and ulnar nerves can be identified through this approach. The interval between the lateral and long heads of the triceps is used, with elevation of the medial (deep) head off the posterior aspect of the shaft.


b. The ulnar nerve emerges medially from deep to the medial head of the triceps. It courses distally through the cubital tunnel. It can be palpated along the medial aspect of the triceps along the distal third of the humerus.


3. Anterior, anteromedial, and direct lateral approaches—These have been described and may be used based on wound considerations, other injuries (ie, need for associated vascular repair), or the need for other approaches based on concomitant injuries.


D. Mechanism of injury and associated injuries


1. Distal humerus fractures may be due to high- or low-energy trauma. In patients with osteoporosis or osteopenia, the bone mineral density is decreased, so less force is required for injury (eg, a fall from a standing position).


2. Torsional, bending, axial, or a combination of these forces can be responsible for humerus fractures. Direct impact or blast injury (eg, gunshot wounds) can cause these fractures as well.


3. With any long-bone injury, associated proximal or distal articular fractures or dislocations may be present, necessitating a complete radiographic examination of the bone, including the joints above and joint below.


4. With high-energy situations, forearm and wrist radiographs are warranted to rule out a "floating elbow" (humeral fracture with associated both-bone forearm fracture).


5. Many neurovascular structures course the upper arm, so associated neurovascular injury may occur.


E. Clinical evaluation


1. Patients typically present with pain, swelling, and deformity (most frequently shortening and varus).


2. Fracture pattern is related to mechanism of injury and bone quality. Therefore, a careful history is imperative to match these factors in cases in which pathologic processes are suspected and would require further workup.


3. Careful neurovascular examination is important because radial nerve injury is a common associated finding.


F. Radiographic studies


1. Standard radiographic series of AP and lateral radiographs should be acquired.


2. When obtaining the transthoracic lateral view, rotating the patient will prevent rotation of the distal fragment and avoid risk of further soft-tissue or nerve injury.


3. Radiographic series should include the shoulder and elbow ("joint above and joint below") to rule out further associated injuries.


4. Traction views may aid in preoperative planning for severely comminuted fractures that meet surgical indications.


5. Advanced imaging studies need be considered only when concomitant intra-articular injury is present or a pathologic process is suspected based on history and initial radiographic evaluation.


G. Classification—Several different systems have been used to classify humeral shaft fractures.


1. OTA classification system—Uses a combination of numbers and letters to describe the fracture: bone number (humerus = 1); location (diaphysis = 2); fracture pattern (simple = A, wedge = B, complex = C); and severity (1 through 3) (

Figure 2).


2. Descriptive classification system—Based on relative location to the pectoralis and deltoid. This provides information as to the relative direction and displacement of the main fracture fragments.


3. Classification system based on the fracture characteristics (transverse, oblique, spiral, segmental, comminuted)—can aid in determining treatment.


H. Nonsurgical treatment


1. This is the treatment of choice for most humeral shaft fractures. A recent review of 922 patients showed that closed treatment with a functional brace resulted in a fracture union rate >98% in closed fractures and >94% in open fractures; 98% exhibited <25° of angulation and had <25° of restricted shoulder motion at the time of brace removal.


2. Closed treatment may involve initial coaptation splinting followed by a functional brace or a hanging arm cast.


a. The coaptation splint is used for 7 to 10 days, followed by application of a fracture brace in the office.


b. Weekly radiographs are obtained for 3 weeks to ensure appropriate maintenance of reduction; thereafter, they are obtained at 3- to 4-week intervals.


c. Immediately upon fracture brace application, the patient is encouraged to do pendulum exercises for shoulder mobility. Elbow, wrist, and hand exercises also are encouraged.


d. The patient is instructed to adjust the tension of the fracture brace twice per week and to sleep in a semi-erect position until 4 to 6 weeks postinjury.


[Figure 2. The OTA classification of humeral shaft fractures.]

e. The fracture brace is worn for 10 to 12 weeks, until there is no pain with palpation at the fracture site, >90° of painless shoulder and elbow motion, and bridging callus is seen radiographically on 3 of 4 cortices.


3. Hanging arm casts may be considered for shortened oblique, spiral, and transverse fractures. The cast should extend from 2 cm proximal to the fracture, across the 90° flexed elbow, and to the wrist; the forearm should be in neutral rotation.



Table 1. Indications for Surgical Treatment of Humeral Shaft Fractures]

   Suspension straps are attached to loops on the forearm aspect of the cast to aid in alignment.


4. No consensus exists on acceptable alignment, but it has been proposed that 20° apex anterior or posterior angulation and 30° varus/valgus, 15° malrotation, and 3 cm shortening are acceptable.


I. Surgical treatment


1. Absolute and relative indications for surgical treatment are listed in Table 1.


2. Outcomes—Open fractures have been shown to have a 12% infection rate without fixation and a 10.8% infection rate with fixation.


3. Surgical procedures


a. Open reduction and plate fixation


i. This is the most common surgical treatment of humeral shaft fractures.


ii. Plate and screw constructs offer union rates ≥94%, with low infection rates (0% to 6%), low incidence of iatrogenic nerve injury (0% to 5%), and the ability for the multiply injured patient to weight bear through the injured extremity.


iii. Conventional plating is traditionally done with a broad 4.5-mm plate with three or four screws per side for axial and torsional stability.


iv. For bending stability when using a long plate, screw placement should include "near-near" and "far-far" relative to the limits of the fracture.


v. In osteoporotic bone, locked plating has been shown to improve stability and resistance to torsional stresses.


b. Intramedullary nailing


i. Advocated by some as an alternative to plate fixation


ii. Originally, nonlocking flexible nails were used and inserted in either an antegrade or retrograde fashion, but the newer interlocking nails have become more common and allow for better rotational control.


iii. Intramedullary nails can be useful in the medically unstable patient to avoid a large exposure, with segmental fractures, with the multiply injured patient to limit positioning changes, and with pathologic fractures.


iv. Intramedullary nails have been shown to withstand higher axial and bending loads than plates, although plated humerus fractures have been shown to clinically allow for full weight bearing and have not shown a higher incidence of malunion or nonunion.


v. Intramedullary nailing of humerus fractures has been shown to result in a higher incidence of shoulder pain.


vi. A recent meta-analysis comparing plating and nailing of humeral shaft fractures has shown that plating results in less need for revision, a lower nonunion rate, and fewer shoulder problems.


c. External fixation


i. Indications—Staged external fixation is indicated with severe soft-tissue injury, bone defects, vascular injury with acute repair, the medically unstable patient, and infected nonunions.


ii. When applying external fixation, care must be taken with respect to neurovascular structures in the arm.


iii. Typically, the elbow joint is spanned with two lateral pins placed proximal to the fracture in the humeral diaphysis and two pins in the ulna or radius, depending on whether a forearm injury is present.


iv. The ulna is the preferred location for pin placement when possible because of its subcutaneous location, limited risk to neurovascular structures, and ability to maintain pronation-supination during the period of external fixation.


v. An open approach is recommended for the humeral pins because of the variability of nerve course in the region. An open approach also should be used if the distal pins are applied to the radius.


4. Surgical pearls


a. To decrease shoulder pain, an anterior starting point for antegrade intramedullary nailing has been suggested.


i. The interval between the anterior and middle third of the deltoid is split and an inline-splitting incision of the rotator cuff is made. This allows a direct path to the intramedullary canal and an easier side-to-side tendon closure.


ii. The surgeon must be aware that the humeral canal ends 2 to 3 cm proximal to the olecranon fossa and it narrows distally, which can result in a risk for fracture distraction when impacting the nail.


b. When plating from a posterior approach, the radial nerve must be identified.


i. The radial nerve can be located by bluntly dissecting deep to bone at a point approximately 2 cm superior to the proximal aspect of the triceps fascia.


ii. The ulnar nerve can be located if necessary by finding the intermuscular septum that separates the posterior and anterior compartments approximately 2 to 3 cm proximal to the flare of the medial epicondyle.


J. Rehabilitation


1. Humeral shaft fractures treated nonsurgically should undergo rehabilitation as described previously in the nonsurgical treatment section (section I.H).


2. Surgically treated fractures can be splinted for 3 to 7 days to rest the soft tissues. Subsequently, active and passive range of motion (ROM) of the shoulder, elbow, wrist, and hand can progress.


3. Resistive strengthening exercises may begin at 6 weeks postoperatively or if nonsurgical treatment is done, when callus with no motion or pain at the fracture sight is evident.


K. Complications


1. Radial nerve palsy


a. Humeral fractures are often associated with radial nerve palsies, whether from the time of injury, attempted closed reduction, or during surgical intervention.


b. A recent meta-analysis of 4,517 fractures found an overall 11.8% incidence of concomitant radial nerve palsies in transverse and spiral fractures, with the middle and mid-distal third most frequently involved.


i. Overall, the recovery rate was 88.1%, whether the palsy was primary or secondary to iatrogenic intervention.


ii. Statistically different rates of recovery were reported for complete (77.6%) versus incomplete (98.2%) and closed (97.1%) versus open (85.7%) injuries.


iii. The onset of spontaneous recovery was evident at an average of 7.3 weeks, with full recovery at an average of 6.1 months.


iv. When nerve exploration was required, it was conducted at an average of 4.3 months.


v. Barring open injury, vascular injury, segmental fracture, or floating elbow, no difference in recovery between early and late exploration could be deduced.


c. With a concomitant nerve injury, in patients who do not require surgical treatment of the fracture, electromyography/nerve conduction velocity studies should be acquired 6 weeks postinjury. In patients who require surgical treatment, exploration is done at the time of surgery.


d. With secondary palsies that occur during fracture reduction, it has not been clearly established that surgery will improve the ultimate recovery rate when compared with results of nonsurgical management. Delayed surgical exploration should be done after 3 to 4 months if no evidence of recovery is apparent using electromyography or nerve conduction velocity studies.


2. Vascular injury is rare with humeral shaft fractures and may be the result of a penetrating injury (eg, industrial accident, gunshot wound). Revascularization should be attempted within 6 hours.


3. Interlocking with humeral nails can place the axillary nerve at risk proximally and the lateral antebrachial cutaneous nerve, median nerve, or brachial artery at risk distally. This risk can be minimized by using a limited open approach with careful blunt dissection to bone when applying interlocking screws for intramedullary humeral nails.


4. With intramedullary nailing, when passing the reamer through an area of comminution, consider turning off the reamer and pushing it through this area manually to avoid damage to the radial nerve.


5. When radial nerve dysfunction is present preoperatively and intramedullary nailing is chosen, consideration should be given to a limited open approach to ensure that the fracture is clear of neurovascular structures.


6. Nonunions—Although union rates are relatively high with humeral shaft fractures, nonunions do occur.


a. Motion, avascularity, gap, and infection are all potential causes of nonunion.


b. With osteopenia and osteoporosis, stability can be difficult to achieve with standard compression plating.


7. Infected nonunions


a. Eradication of the infection is important to help achieve union.



Figure 3. Anterior and posterior views of the anatomy of the distal articular surface of the humerus. The capitellotrochlear sulcus divides the capitellar and trochlear articular surfaces. The lateral trochlear ridge is the key to analyzing humeral condyle fractures. In type I fractures, the lateral trochlear ridge remains with the intact condyle, providing medial-to-lateral elbow stability. In type II fractures, the lateral trochlear ridge is a part of the fractured condyle, which may allow the radius and ulna to translocate in a medial-to-lateral direction with respect to the long axis of the humerus.]

b. In select cases of severe infection, temporary or definitive external fixation along with resection of affected tissue and antibiotic treatment may be required.


c. Whether required by atrophic nonunion or infection, resection and shortening of up to 4 cm can be tolerated.


8. Nerve conduction velocity studies can be considered after 6 weeks to help determine a baseline for prognosis and severity of nerve injury.


9. Ultrasound has also been suggested as a modality for nerve evaluation but is very dependent on the quality of the technician, radiologist, and ultrasound machine.

II. Distal Humerus Fractures

A. Epidemiology


1. Intercondylar fractures are the most common distal humerus fracture pattern.


2. Extension supracondylar fractures account for >80% of all supracondylar fractures.


3. Fractures of the capitellum constitute approximately 1% of all elbow injuries.


4. Fractures of a single condyle (lateral more common than medial) account for 5% of all distal humerus fractures.


B. Anatomy (Figure 3)


1. The elbow is a constrained, hinged joint. The ulna rotates around the axis of the trochlea, which is positioned in relative valgus and external rotation.


2. The capitellum articulates with the proximal radius and is involved with forearm rotation, not elbow flexion/extension. Posteriorly, the capitellum is nonarticular and allows for distal posterolateral hardware placement.


3. Medially, the medial collateral ligament originates on the distal surface of the medial epicondyle. The ulnar nerve resides in the cubital tunnel in a subcutaneous location.


4. Laterally, the lateral collateral ligament originates on the lateral epicondyle, deep to the common extensor tendon.


C. Classification


1. Classifications of fractures of the distal humerus were traditionally descriptive and based on the number of columns involved and the location of the fracture (ie, supracondylar, transcondylar, condylar, and bicondylar)(

Table 2).


2. The OTA classification system divides these fractures into type A (extra-articular), type B (partial articular), and type C (complete articular).



Each category is subclassified based on the degree and location of fracture comminution.


[Table 2. Descriptive and Anatomic Classifications of Distal Humerus Fractures]


It has been shown that the OTA classification has substantial agreement with regard to fracture type (A, B, and C) but is less reliable with regard to subtype.


D. Surgical approaches


1. Extra-articular and partial articular fractures are typically approached through a posterior triceps-splitting or triceps-sparing approach.


a. With a triceps-splitting approach, a posterior incision is made and carried deep to the triceps, which is subsequently split between the long and lateral heads and distally at its ulnar insertion.


b. The triceps-sparing approach involves mobilization of the ulnar nerve and subsequent elevation of the entire extensor mechanism in continuity, progressing from medial to lateral. Upon completion of the procedure, reattachment of the extensor mechanism through drill holes in the ulna and to the flexor carpi ulnaris fascia is required.


c. An alternative approach is the posterior triceps-preserving approach. It involves mobilization of the triceps off the posterior humerus from the medial and lateral aspects of the intermuscular septum. The ulnar nerve (medially) and the radial nerve (laterally and proximally) need to be identified and preserved.


2. Simple fractures often can be stabilized through one of these approaches with either lag screws alone or screws and an antiglide plate.


3. With an isolated lateral column or capitellar fracture, a Kocher approach may be considered.


a. Either a posterior skin incision or an incision going from the lateral epicondyle to a point 6 cm distal to the olecranon tip can be used. The incision can be extended proximally as needed.


b. For capitellar exposure, the interval of the anconeus and extensor carpi ulnaris can be opened.


4. Complete articular fractures can be repaired using one of the above approaches if adequate articular reduction and fixation can be achieved. With increasing complexity of the articular injury, they may require direct visualization through a transolecranon osteotomy.


a. It is necessary to find and free the ulnar nerve before performing an olecranon osteotomy. A chevron-style osteotomy pointing distally is made at the level of the nidus of the olecranon.


b. Some believe in drilling and tapping the proximal ulna for larger screw insertion before osteotomizing the olecranon to facilitate later fixation.


c. Once the osteotomy is complete, the entire extensor mechanism can be reflected proximally to allow visualization of the entire distal humerus.


d. Fixation of the osteotomy can be performed using Kirschner wires and a tension band, long large-fragment intramedullary screw fixation with a tension band, a plate, or two small-fragment lag screws that penetrate the anterior ulnar cortex distal to the site of the osteotomy.


e. An olecranon osteotomy is a potential site for nonunion, hardware discomfort, and need for future procedures.


5. Patients with open distal humerus injuries have been shown to have worse functional and ROM scores.


6. Regardless of the approach used for fixation, the goals of fixation are anatomic articular reduction, stable internal fixation, and early range of elbow motion.


a. In patients with irreconstructible or missing segments of the articular surface, care must be taken to avoid decreasing the dimensions of the trochlea and limiting the ability for flexion and extension.


b. Once articular reduction is accomplished, stable fixation of the distal end to the metadiaphyseal component with restoration of the mechanical axis is performed.


E. Mechanism of injury


1. Distal humerus fractures can result from low-energy falls (common in the elderly) or high-energy trauma with extensive comminution and intra-articular involvement (eg, gunshot wounds, motor vehicle accidents, falls from a height).


2. The amount of elbow flexion at the time of impact can affect fracture pattern.


3. A transcolumnar fracture results from an axial load directed through the forearm with the elbow flexed 90°.


4. With the elbow in a similar position but with direct impact on the olecranon, an olecranon fracture with or without distal humerus fracture may result.


5. With the elbow in >90° of flexion, an intercondylar fracture may result.


6. Potential associated injuries include elbow dislocation, floating elbow (humerus and forearm fracture), and concomitant "terrible triad" injuries (olecranon, coronoid, radial head/neck fractures).


F. Clinical evaluation


1. Patients typically present with elbow pain and swelling. Crepitus and/or gross instability with attempted range of elbow motion is often observed.


2. Excessive motion testing should not be done because of the risk of further neurovascular injury.


3. A careful neurovascular examination should be performed because all neurovascular structures to the forearm and hand cross the area of injury and sharp bone fragments can cause damage, especially to the radial nerve, ulnar nerve, and brachial artery.


4. Serial compartment examinations may be required because of extreme cubital fossa swelling or in the obtunded patient to avoid missing a volar forearm compartment syndrome with resultant Volkmann contracture.


G. Radiographic evaluation


1. AP and lateral radiographs of the humerus and elbow are required.


2. When concomitant elbow injuries are present, forearm and wrist radiographs may be needed.


3. To aid in preoperative planning, traction radiographs, oblique radiographs, and CT scans may be of value.


4. Recently, a blinded study comparing evaluation of distal humerus fractures based on two-dimensional CT scans and plain radiographs versus three-dimensional CT scans showed that three-dimensional CT scans improved the intraobserver and interobserver reliability of two commonly used classification systems.


H. Supracondylar fractures—These are OTA type A fractures that are distal metaphyseal and extra-articular.


1. Nonsurgical treatment is reserved for nondisplaced or minimally displaced fractures or for comminuted fractures in elderly low-demand patients.


a. A splint is applied for 1 to 2 weeks before initiation of ROM exercises.


b. At 6 weeks, with progressive evidence of healing, immobilization may be discontinued completely.


c. Up to 20° loss of condylar-shaft angle may be acceptable.


2. Surgical treatment is indicated for most displaced fractures as well as those associated with an open injury or vascular injury.


a. Open reduction and internal fixation (ORIF) is typically done, with plates placed on the medial and lateral columns.


b. Biomechanically, 90-90 plating (medial and posterolateral), bicolumnar plating (medial and lateral), and locked plating constructs have been shown to be effective in supplying adequate stability.


3. ROM exercises may be initiated once the soft tissues allow.


I. Transcondylar fractures


1. Epidemiology—Transcondylar fractures traverse both columns, reside within the joint capsule, and are typically seen in elderly patients.


2. Mechanism of injury—These fractures occur with a flexed elbow or a fall on an outstretched hand with the arm in abduction or adduction.


3. Clinical evaluation—The examiner must be wary of a Posadas fracture, which is a transcondylar



Figure 4. Intercondylar fractures. A, Type I undisplaced condylar fracture of the elbow. B, Type II displaced but not rotated T-condylar fracture. C, Type III displaced and rotated T-condylar fracture. D,Type IV displaced, rotated, and comminuted condylar fracture.]


Table 3. Two-column Intercondylar Distal Humerus Fractures]

   fracture with anterior displacement of the distal fragment with concomitant dislocation of the radial head and proximal ulna from the fragment.


4. Treatment


a. Nonsurgical and surgical management follow recommendations and principles similar to those for supracondylar fractures.


b. Total elbow arthroplasty may be considered in the elderly with very distal fractures and poor bone quality.


J. Intercondylar fractures (Figure 4)


1. Epidemiology—Intercondylar fractures are the most common distal humerus fracture; frequently they are comminuted.


2. Classification


a. According to the OTA classification, these are type C fractures.


b. Table 3 lists the descriptive types.


3. Pathoanatomy—The medial flexor mass and lateral extensor mass are responsible for rotation and proximal migration of the articular surface.


4. Treatment


a. Treatment is primarily surgical, using medial and lateral plate fixation according to the principles and fixation types described previously.


b. In some bicondylar fractures with simple fracture lines and adequate bone quality, lag screw or columnar screw fixation may be used alone



Figure 5. Milch lateral column fractures. Type I fractures: the lateral trochlear ridge remains attached, preventing dislocation of the radius and ulna; Type II fractures: the lateral trochlear ridge is a part of the fractured lateral condyle, resulting in dislocation of the radius and ulna.]

   or in concert with plate constructs if fracture morphology or osteopenia dictates.


c. The goal is stable fixation to allow early range of elbow motion.


d. In younger patients with extremely comminuted, distal, intra-articular fractures, mini-fragment fixation can help stabilize smaller fragments.


e. With older, medically unfit, or demented patients, "bag of bones" nonsurgical treatment has been described. This involves approximately 2 weeks of immobilization in 90° of elbow flexion followed by gentle ROM to ultimately achieve a minimally painful, functional pseudarthrosis.


f. Total elbow arthroplasty may be used in elderly patients. In a recent review of 49 elderly patients with distal humerus fractures treated with total elbow arthroplasty, the average flexion arc was 24° to 131° and the Mayo elbow performance score averaged 93 out of a possible 100.


K. Condylar fractures


1. Classification


a. These represent OTA type B (partial articular) fractures of the distal humerus.


b. They can be divided into low or high medial/lateral column fractures.


i. The following characteristics make a condylar fracture "high": the involved column includes most of the trochlea; the forearm follows the displacement of the fractured column.



Figure 6. Fractures of the capitellum. Type I: Hahn-Steinhal fragment; type II: Kocher-Lorenz fragment; type III: comminuted and multifragmented.]

ii. Because of the larger size of "high" column fractures, internal fixation is more straightforward and can frequently be achieved using lag screws with or without unilateral plating.


iii. Lateral column fractures are more common.


iv. Milch tried to determine fracture stability based on pattern (Figure 5). It was suggested that type I fractures (lateral wall of trochlea attached to main mass of humerus) were "stable" relative to type II fractures (lateral wall of trochlea attached to displaced fracture fragment).


2. Treatment


a. Surgical treatment is recommended for all but nondisplaced fractures.


b. Nonsurgical—The elbow is positioned in 90° of flexion with the forearm in supination or pronation for lateral or medial column fractures, respectively.


L. Capitellum fractures


1. Classification—Capitellum fractures can be classified into three types (Figure 6).


a. Type I (Hahn-Steinhal fragment): These involve a large osseous component of the capitellum that can include some involvement of the trochlea.


b. Type II (Kocher-Lorenz fragment): These are separations of articular cartilage with minimal attached subchondral bone.


c. Type III: These are severely comminuted multifragmentary fractures.


2. Treatment


a. Type I fractures usually require ORIF. Mini-fragment screw fixation from posterior to anterior or countersunk minifragment screws from anterior to posterior can be used. Alternatively, headless screws may be used.


b. Typically, type II fractures and irreconstructible parts of type III fractures are excised.


3. Complications—If instability is present or creeping substitution of devascularized fragments is unsuccessful, arthritis, osteonecrosis, decreased motion, cubital valgus, and tardy ulnar nerve palsy can result.


M. Trochlear fractures


1. Epidemiology—These fractures in isolation are extremely rare. When they occur, a high index of suspicion for an associated elbow dislocation that caused a shearing of the articular surface is warranted.


2. Treatment


a. Nondisplaced fractures may be treated with 3 weeks of immobilization followed by ROM exercises.


b. Displaced fractures require ORIF or excision if not reconstructible.


N. Epicondylar fractures


1. Epicondylar fractures may occur on the medial or lateral aspect of the elbow.


2. Treatment


a. Epicondylar fractures that are nondisplaced and have a stable elbow joint to ROM may be treated nonsurgically.


b. In children, medial epicondyle fractures with up to 5 mm of displacement may be treated nonsurgically if no concomitant instability or nerve deficits exist.


c. If significantly displaced or with concomitant elbow instability or ulnar nerve symptoms, ORIF with screws or Kirschner wires is recommended.


d. Consider excision in patients who present late with a painful nonunion or fragment that cannot be reconstructed.


O. Fracture of the supracondylar process


1. Anatomy


a. The supracondylar process is a bony protrusion on the anteromedial surface of the distal humerus and represents a congenital variant.


b. The ligament of Struthers courses a path from the supracondylar process to the medial epicondyle.


c. Fibers of the pronator teres or the corachobrachialis may arise from this ligament.


2. Treatment


a. Fracture of the supracondylar process is most frequently treated nonsurgically.


b. Excision is required only if there is an associated brachial artery injury or median nerve compression.


P. Surgical pearls


1. When approaching the distal humerus from a posterior location, the ulnar nerve should be identified. Approximately 2 cm proximal to the superior aspect of the medial epicondyle, the nerve can be palpated as it emerges in the area of the intermuscular septum. Subsequently, it can be dissected to the first motor branch to the flexor carpi ulnaris.


2. If surgical dissection must be carried proximally or laterally, the radial nerve can be found in one of two ways.


a. Blunt deep dissection approximately 2 cm proximal to the fascia of the confluence of the triceps mechanism will allow the radial nerve to be palpated in the spiral groove.


b. Posterolaterally, the radial nerve can be found by retracting the triceps medially to expose the lateral brachial cutaneous nerve that branches off the radial nerve on the posterior aspect of the lateral intermuscular septum. This can be traced proximally to identify the radial nerve proper.


3. When performing an olecranon osteotomy, one should make sure that the apex of the chevron points distally to ensure a larger proximal fragment. This minimizes the risk of its fracture with later osteotomy repair.


4. The olecranon osteotomy can be initiated with an oscillating saw but should be completed with an osteotome to avoid taking a curf that would result in decreasing the olecranon arc upon repair of the osteotomy.


5. Transient sensory ulnar nerve symptoms may occur. Patients should be warned of this preoperatively.


6. Although the ulnar nerve may be transposed, some return it to its native location providing there is no tethering or abrasive hardware in its path.


7. When operating on a severely comminuted distal humerus fracture in an elderly individual, with the possibility of poor bone quality or a very distal fracture, one should be prepared to perform a total elbow arthroplasty. If attempting internal fixation, choose a surgical exposure that will not negatively affect arthroplasty placement if the fracture cannot be reconstructed.


Q. Rehabilitation


1. Postoperatively, the elbow should be immobilized at 90° of flexion, with a wound check at 2 to 3 days.


2. Active and passive ROM of the shoulder, elbow, wrist, and hand is usually initiated within a few days of surgery. If the soft tissue is tenuous, the elbow motion is deferred until 7 to 10 days postoperatively, but the other therapy is initiated.


3. Typically, with a posterior approach, resistive exercises, especially extension, are delayed for 6 weeks.


R. Outcomes—Closed injuries treated with ORIF can ultimately expect approximately 105° arc of motion and the return of approximately 75% of flexion and extension strength. Loss of elbow extension is typically greater than loss of flexion.


S. Complications


1. Fixation failure and malunion are more common with inadequate fixation.


2. Nonunion can occur at either the distal humerus fracture or the olecranon osteotomy. When appropriate principles are followed, the incidence is relatively low. With higher energy trauma and greater soft-tissue injury, the risk is higher.


3. Infection is a relatively uncommon complication (0% to 6%) and has been described most commonly with grade 3 open fractures.


4. Ulnar nerve palsy can be very debilitating. Iatrogenic injury, inadequate release, impingement due to bony causes or hardware, and postoperative fibrosis may all be causes.


5. Posttraumatic arthritis can result from inappropriate articular reduction or a devastating initial injury. Revision surgery, allograft, or total elbow arthroplasty may all be considered in such instances.

Top Testing Facts

1. Most humeral shaft fractures can be treated nonsurgically.


2. Indications for surgical management of humeral shaft fractures include vascular injury, severe soft-tissue injury, open fracture, floating elbow, concomitant intraarticular elbow injury, and pathologic fractures.


3. Extension-type supracondylar fractures account for most supracondylar fractures


4. Intramedullary nailing of humeral shaft fractures is associated with a higher rate of shoulder pain.


5. The "terrible triad" of elbow injuries involves fractures of the olecranon, coronoid, and radial head/neck.

6. For patients with a concomitant radial nerve injury who do not require surgical treatment, electromyography/nerve conduction velocity studies should be performed 6 weeks postinjury. For those who require surgical treatment, exploration is done at the time of surgery.


7. Total elbow arthroplasty should be considered in low-demand elderly individuals who sustain a complex distal humerus fracture.


8. The ligament of Struthers extends from the supracondylar process to the medial epicondyle.


9. In general, intercondylar fractures are managed surgically with medial and lateral plate fixation.


10. The chevron-type olecranon osteotomy should be pointed distal to minimize fracturing of the olecranon fragment.


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