summary Distal Humerus Fractures are traumatic injuries to the elbow that comprise of supracondylar fractures, single column fractures, column fractures or coronal shear fractures. Diagnosis is made with plain radiographs of the humerus and elbow. CT scan is helpful for intra-articular assessment and operative planning. Treatment is usually open reduction and internal fixation. Epidemiology Incidence accounts for 0.5-7% of all fractures accounts for 30% of elbow fractures Demographics most common in young males and older females Anatomic location distal intercondylar fractures are the most common fracture pattern Etiology Forms distal humerus fractures are traumatic injuries that include supracondylar fractures single column (condyle) fractures bicolumn fractures coronal shear fractures Pathophysiology mechanism low energy falls in elderly high energy impact in younger population pathoanatomy elbow position affects fracture type elbow flexed < 90° axial load leads to transcolumnar fracture direct posterior blow leads to olecranon fracture with or without distal humerus involvement elbow flexed > 90° may lead to intercondylar fracture Associated injuries elbow dislocation terrible triad injury floating elbow Volkmann contracture results from missed forearm compartment syndrome Anatomy Osteology elbow is a hinged joint trochlea articulates with sigmoid notch allows for flexion and extension capitellum articulates with proximal radius allows for forearm rotation Muscles common flexors (originate from medial epicondyle) pronator teres flexor carpi radialis palmaris longus FDS FCU common extensors (originate from lateral epicondyle) anconeus ECRL ECRB extensor digitorum comminus EDM ECU Ligaments medial collateral ligament anterior bundle originates from distal medial epicondyle inserts on sublime tubercle primary restraint to valgus stress at the elbow from 30-120° tight in pronation lateral collateral ligament originates from distal lateral epicondyle inserts on crista supinatorus stabilizer against posterolateral rotational instability tight in supination Nerves ulnar nerve resides in the cubital tunnel in a subcutaneous position below the medial condyle radial nerve resides in the spiral groove 15cm proximal to distal humeral articular surface also can be reliable found 3.9 cm (two finger-breadths) proximal to the triceps aponeurosis. runs between brachioradialis and brachialis proximal to elbow divides into PIN and superficial radial nerve at the level of the radial head Classification Can be classified as supracondylar fractures distal single column fractures subclassified using Milch classification system (see table) lateral condyle more common than medial distal bicolumnar fractures classified using Jupiter classification system (see table) 5 major articular fragments have been identified capitellum/lateral trochlea lateral epicondyle posterolateral epicondyle posterior trochlea medial trochlea/epicondyle AO/OTA Classification of Distal Humerus Fractures Type A Extra-articular (supracondylar fracture), 80% are extension type; epicondyle Type B Intraarticular- Single column (partial articular-isolated condylar, coronal shear, epicondyle with articular extension) Type C Intraarticular- Both columns fractured and no portion of the joint contiguous with the shaft (complete articular) Each type further divided by degree and location of fracture comminution Milch Classification of Single Column Condyle Fractures Milch Type I Lateral trochlear ridge intact Milch Type II Fracture through lateral trochlear ridge Jupiter Classification of Two-Column Distal Humerus Fractures High-T Transverse fx proximal to or at upper olecranon fossa Low-T Transverse fx just proximal to trochlea (common) Y Oblique fx line through both columns with distal vertical fx line H Trochlea is a free fragment (risk of AVN) Medial lambda Proximal fx line exists medially Lateral lambda Proximal fx line exists laterally Multiplane T (not pictured) T type with an additional fracture in coronal plane Presentation Symptoms elbow pain and swelling Physical exam gross instability often present avoid ROM due to risk of neurovascular damage neurovascular exam check function of radial, ulnar, and median nerves check distal pulses brachial artery may be injured if pulse decreased, obtain noninvasive vascular studies and consult vascular surgery if abnormal monitor carefully for forearm compartment syndrome Imaging Radiographs recommended views AP lateral additional views obtain wrist radiographs if elbow injury present or distal tenderness on exam oblique and traction radiographs may assist with surgical planning specifically used to evaluate if there is continuity of the trochlear fragment with the medial epicondylar fragment, this can influence hardware choice CT often obtained for surgical planning especially helpful when shear fractures of the capitellum and trochlea are suspected MRI usually not indicated in acute injury Treatment Nonoperative cast immobilization indications nondisplaced Milch Type I fractures Operative closed reduction and percutaneous pinning (CRPP) indications displaced Mich Type I fractures ORIF indications supracondylar fractures intercondylar / bicolumnar fractures Milch Type II fractures total elbow arthroplasty indications distal bicolumnar fractures in elderly patients Techniques Cast Immobilization technique immobilize in supination for lateral condyle fractures immobilize in pronation for medial condyle fractures ORIF approach posterior superficial approach exposures triceps-splitting (Campbell) technique split triceps tendon in midline down to olecranon triceps-sparing (paratricipital, Alonso-Llames, medial and lateral windows) indications extra-articular fractures fractures with a simple articular split technique elevate triceps from the humerus using medial and lateral windows can be converted to olecranon osteotomy if needed olecranon osteotomy indications complex intra-articular fractures fractures with a coronal splint contraindications total elbow arthroplasty is planned/may be required technique perform chevron (apex distal) osteotomy fixation of osteotomy performed using a combination of screws, K wires, tension band or plate complications AIN nerve injury check ability to flex thumb interphalangeal joint in recovery symptomatic hardware triceps-reflecting (Bryan-Morrey) technique reflect triceps tendon, forearm fascia, and periosteum off the olecranon from medial to lateral repair through transosseous drill holes immobilize to protect triceps repair for 4-6 weeks postoperatively triceps-reflecting anconeous pedicle (O'Driscoll) technique elevate anconeous subperiosteally from proximal ulna lateral muscles interval technique elevate the ECRB and part of the ECRL off of the supracondylar ridge fixation perform provisional reduction with k-wires if metaphyseal injury is not comminuted, reducing one column to the metaphysis first may be beneficial perform fixation of articular fragments with countersunk/headless screws consider using positional screws when reducing trochlea to avoid narrowing it with compression perform fixation of condyles and epitrochlear ridge fix the lateral epicondyle using a tension band wire or plate fix the articular segment to the shaft using two plates in orthogonal planes new literature supports parallel plates if the ulnar nerve contacts medial hardware during flexion/extension, can perform an ulnar nerve transposition no difference between rates of post-operative ulnar neuritis with in situ release compared to transposition no difference in patient-reported outcomes between transposition and in-situ release postoperative splint elbow in 70° of flexion remove splint at 48 hours post-operatively and initiate ROM exercises if osteotomy performed active and active-assisted flexion and extension for 6 weeks no active extension against gravity or resistance no restrictions to rotation if osteotomy not performed active motion against gravity without restrictions no restrictions to rotation start gentle strengthening program at 6 weeks and full strengthening program at 3 months Total Elbow Arthroplasty indications communited articular fractures in osteoporotic bone inflammatory conditions (e.g. RA) complications specific to this treatment activity restrictions (e.g. can not lift more than 5 pounds) implant loosening polyethylene wear periprosthetic fracture functional outcomes similar with salvage arthroplasty following failed ORIF Complications Elbow stiffness most common Heterotopic ossification seen in 8% routine prophylaxis is not warranted due to increased rate of nonunion in patients treated with indomethacin Nonunion low incidence avoid excessive soft-tissue stripping Malunion avoided by proper surgical technique cubitus valgus (lateral column fractures) cubitus varus (medial column fractures) AIN injury can be seen with olecranon osteotomy Ulnar nerve injury Postoperative ulnar nerve palsies are most often secondary due to traction during open reduction and internal fixation DJD Prognosis Majority of patients regain 75% of elbow motion and strength goal is to restore elbow ROM 30-130° of flexion Total elbow arthroplasty has rates of implant survival >75% at 10 years if used with appropriate indications Unsatisfactory outcomes in up to 25% treatment of these fractures is complex due to low fracture line of one or both columns metaphyseal fragmentation of one or both columns articular comminution poor bone quality