Summary Proximal humerus fractures are common fractures often seen in older patients with osteoporotic bone following a ground-level fall on an outstretched arm. Diagnosis is made with orthogonal radiographs of the shoulder. Treatment with sling immobilization is indicated for minimally displaced fractures with surgical fixation versus arthroplasty indicated in more complex and displaced fractures. Epidemiology Incidence common 4-6% of all fractures third most common non-vertebral fracture pattern seen in the elderly (>65 years old) two-part surgical neck fractures are most common Demographics 2:1 female to male ratio increasing age associated with more complex fracture types Anatomic location may occur at the surgical neck, anatomic neck, greater tuberosity, and lesser tuberosity two-part surgical neck fractures are most common Risk factors osteoporosis diabetes epilepsy female gender Etiology Pathophysiology mechanism low-energy falls elderly with osteoporotic bone high-energy trauma young individuals concomitant soft tissue and neurovascular injuries pathoanatomy vascularity of articular segment is more likely to be preserved if ≥ 8mm of calcar is attached to articular segment predictors of humeral head ischemia (Hertel criteria) <8 mm of calcar length attached to articular segment disrupted medial hinge increasing fracture complexity displacement >10mm angulation >45° predictors of humeral head ischemia does not necessarily predict subsequent avascular necrosis Associated conditions nerve injury axillary nerve injury most common arterial injury uncommon (incidence 5-6%), higher likelihood in older patients most often occur at level of surgical neck or with subcoracoid dislocation of the head Anatomy Osteology anatomic neck represents the old epiphyseal plate surgical neck represents the weakened area below head more often involved in fractures than anatomic neck average neck-shaft angle is 135 degrees Muscles pectoralis major displaces shaft anteriorly and medially deltoid displaces proximal fragment laterally supraspinatus, infraspinatus, and teres minor externally rotate greater tuberosity subscapularis internally rotates articular segment or lesser tuberosity Ligaments Coracohumeral ligament attaches to coracoid and greater tuberosity and strengthens the rotator interval SGHL restraint to inferior translation at 0° degrees of abduction (neutral rotation) MGHL resists AP translation in the midrange (~45°) of abduction IGHL restraint to AP translation at 90° degrees of abduction Blood Supply anterior humeral circumflex artery large number of anastomosis with other vessels in the proximal humerus branches anterolateral ascending branch arcuate artery is the terminal branch and main supply to greater tuberosity posterior humeral circumflex artery recent studies suggest it is the main blood supply to humeral head Classification AO/OTA organizes fractures into 3 main groups and additional subgroups based on fracture location status of the surgical neck presence/absence of dislocation Neer classification based on anatomic relationship of 4 segments greater tuberosity lesser tuberosity articular surface shaft considered a separate part if displacement of > 1 cm 45° angulation Neer Classification Minimally displaced Two-part Three-part Four-part Anatomical neck Surgical Neck Greater Tuberosity Lesser Tuberosity Fracture-Dislocation Head Split Presentation Symptoms pain and swelling decreased motion Physical exam inspection extensive ecchymosis of chest, arm, and forearm neurovascular exam axillary nerve injury most common determine function of deltoid muscle and lateral shoulder sensation arterial injury may be masked by extensive collateral circulation preserving distal pulses examine for concomitant chest wall injuries Imaging Radiographs recommended views complete trauma series true AP (Grashey) scapular Y axillary additional views apical oblique Velpeau West Point axillary findings combined cortical thickness (medial + lateral thickness >4 mm) studies suggest correlation with increased lateral plate pullout strength pseudosubluxation (inferior humeral head subluxation) caused by blood in the capsule and muscular atony CT scan indications preoperative planning humeral head or greater tuberosity position uncertain intra-articular comminution concern for head-split fracture MRI indications rarely indicated useful to identify associated rotator cuff injury Treatment Nonoperative sling immobilization followed by progressive rehabilitation indications most proximal humerus fractures can be treated nonoperatively including minimally displaced surgical and anatomic neck fractures greater tuberosity fracture displaced < 5mm >5mm displacement will result in impingement with loss of abduction and external rotation fractures in patients who are not surgical candidates additional variables to consider age fracture type fracture displacement bone quality dominance general medical condition concurrent injuries outcomes immediate physical therapy results in faster recover Operative closed reduction percutaneous pinning (CRPP) indications 2-part surgical neck fractures 3-part and valgus-impacted 4-part fractures in patients with good bone quality, minimal metaphyseal comminution, and intact medial calcar outcomes considerably higher complication rate compared to ORIF, HA, and RSA axillary nerve at risk with lateral pins musculocutaneous nerve, cephalic vein, and bicep tendon at risk with anterior pins ORIF indications greater tuberosity displaced > 5mm displaced 2-part fractures 3-, and 4-part fractures in younger patients head-splitting fractures in younger patients outcomes medial support necessary for fractures with posteromedial comminution consider use of a fibula strut if concerned about medial support or bone quality calcar screw placement critical to decrease varus collapse of head Intramedullary nailing indications surgical neck fractures or 3-part greater tuberosity fractures in younger patients combined proximal humerus and humeral shaft fractures outcomes biomechanically inferior with torsional stress compared to plates favorable rates of fracture healing and ROM compared to ORIF Arthroplasty indications hemiarthroplasty in younger patients (40-65 years old) with complex fracture-dislocations or head-splitting components that may fail fixation recommended use of convertible stems to permit easier conversion to RSA if necessary in future reverse total shoulder low-demand elderly individuals with non-reconstructible tuberosities and poor bone stock older patients with fracture-dislocation reverse total shoulder arthroplasty following failed nonoperative management is associated with better functional outcomes than reverse total shoulder arthroplasty following failed open reduction and internal fixation outcomes improved results if anatomic tuberosity reduction and healing restoration of humeral height and version humeral height is best judged from the superior border of the pectoralis major insertion poor results with tuberosity nonunion or malunion retroversion of humeral component > 40° Treatment by Fracture Type Two-part fractures Surgical Neck Most common fx pattern Deforming forces: 1) pectoralis pulls shaft anterior and medial2) head and attached tuberosities stay neutral Nonoperative Closed reduction often possible Sling Operative -indications controversial -technique --- CRPP --- Plate fixation --- IM nail Greater tuberosity Often missed Deforming forces: GT pulled superior and posterior by SS, IS, and TM Can only accept minimal displacement (<5mm) or else it will block ER and ABD Nonoperative indicated for GT displaced < 5 mm Operative indicated for GT displacement > 5 mm - isolated screw fixation only in young with good bone stock - non-absorbable suture technique for osteoporotic bone (avoid hardware due to impingement) -tension band wiring Lesser tuberosity Assume posterior dislocation until proven otherwise Nonoperative Minimally or non-displaced Operative ORIF if large fragment excision with RCR if small Anatomic neck Rare Nonoperative Minimally or non-displaced Operative ORIF in young ORIF v. hemiarthroplasty v. reverse total shoulder arthroplasty in elderly Three-part fracture Surgical neck and GT Subscap will internally rotate articular segment Often associated with longitudinal RCT Nonoperative if: Minimally displaced (GT<5 mm; articular segment <1 cm and <45 degrees) Poor surgical candidate Operative: Young patient - percutaneous pinning (good results, protect axillary nerve) - IM fixation (violates cuff) - locking plate (poor results with high rate of AVN, impingement, infection, and malunion) Elderly patient - hemiarthroplasty with RCR or tuberosity repair vs. reverse total shoulder arthroplasty Surgical neck and LT Unopposed pull of posterior cuff musculature leads articular surface to point anterior Often associated with longitudinal RCT Trend towards nonoperative management given high complications with ORIF Young patient - percutaneous pinning (good results, protect axillary nerve) - IM fixation (violates cuff) - locking plate (poor results with high rate of AVN, impingement, infection, and malunion) Elderly patient - hemiarthroplasty with RCR or tuberosity repair vs. reverse total shoulder arthroplasty Four-Part Fracture Valgus impacted fracture Radiographically will see alignment between medial shaft and head segments Low rate of AVN if posteromedial component intact thus preserving intraosseous blood supply Surgical technique 1. raise articular surface and fill defects 2. repair tuberosities 4-part with head-splitting fracture Characterized by high risk of AVN (21-75%) Deforming forces:1) shaft pulled medially by pectoralis Young patient - ORIF vs. hemiarthroplasty (hemiarthroplasty favored for non-reconstructible articular surface, severe head split, extruded anatomic neck fracture) Elderly patient - hemiarthroplasty v. reverse total shoulder arthroplasty Techniques Sling immobilization followed by progressive rehabilitation technique sling for comfort x2-3wks, immediate physical therapy for early ROM CRPP (closed reduction percutaneous pinning) approach percutaneous technique use threaded pins but do not cross cartilage externally rotate shoulder during pin placement engage cortex 2 cm inferior to inferior border of humeral head complications with lateral pins risk of injury to axillary nerve with anterior pins risk of injury to biceps tendon, musculocutaneous n., cephalic vein possible pin migration ORIF approach anterior (deltopectoral) lateral (deltoid-splitting) increased risk of axillary nerve injury technique heavy nonabsorbable sutures figure-of-8 technique should be used for isolated greater tuberosity fx reduction and fixation (avoid hardware due to impingement) isolated screw may be used for greater tuberosity fx reduction and fixation in young patients with good bone stock locking plate screw cut-out (up to 14%) is the most common complication following ORIF with a periarticular locking plates more elastic than blade plate making it a better option in osteoporotic bone place plate lateral to the bicipital groove and pectoralis major tendon to avoid injury to the ascending branch of anterior humeral circumflex artery placement of an inferomedial calcar screw(s) can prevent postoperative varus collapse, especially in osteoporotic bone fibular strut allograft augmentation has been shown to reduce rates of humeral head height loss and varus collapse postoperative Rehabilitation important part of management best results with guided protocols (3-phase programs) early passive ROM active ROM and progressive resistance advanced stretching and strengthening program prolonged immobilization leads to stiffness Intramedullary nailing approach superior deltoid-splitting approach technique lock nail with trauma or pathologic fractures straight nails are placed through the superior articular cartilage (more central entry point) nails with proximal bend are placed through an entry point just medial to rotator cuff insertion complications rod migration in older patients with osteoporotic bone is a concern shoulder pain from violating rotator cuff nerve injury with interlocking screw placement radial nerve at risk with lateral to medial distal screw musculocutaneous nerve at risk with anterior to posterior distal screw Hemiarthroplasty approach anterior (deltopectoral) technique for fractures cerclage wire or suture passed through hole in prosthesis and tuberosities improves fracture stability place greater tuberosity ~8 mm below articular surface of humeral head (HTD = head to tuberosity distance) nonanatomic placement of tuberosities results in impairment in external rotation kinematics with an 8-fold increase in torque requirements height of the prosthesis best determined off the superior edge of the pectoralis major tendon 5.6cm between top of humeral head and superior edge of tendon post-operative passive external rotation places the most stress on the lesser tuberosity fragment Reverse shoulder arthroplasty approach anterior (deltopectoral) anterolateral deltoid split technique for fractures ensure adequate glenoid bone stock ensure functioning deltoid muscle repair of the greater tuberosity is always recommended despite ability of RSA design to compensate for non-functioning tuberosities/rotator cuff improves range of motion Complications Screw cut-out incidence most common complication following periarticular locking plating fixation (up to 14%) Avascular necrosis risk factors risk factors for humeral head ischemia are not the same for developing subsequent avascular necrosis better tolerated than in lower extremity no relationship to type of fixation (plate or cerclage wires) Nerve injury incidence axillary nerve injury most common (up to 58% with studies using EMG) increased risk with lateral (deltoid-splitting) approach axillary nerve is usually found ~5-7cm distal to the tip of the acromion at risk with lateral pins in CRPP suprascapular nerve (up to 48%) musculocutaneous nerve at risk with anterior pins in CRPP Malunion usually varus apex-anterior or malunion of GT results inferior if converting from varus malunited fracture to TSA use reverse shoulder arthroplasty instead Nonunion most common after two-part surgical neck fracture treatment of chronic nonunion/malunion in the elderly should include arthroplasty lesser tuberosity nonunion leads to weakness with lift-off testing greater tuberosity nonunion after arthroplasty leads to lack of external rotation and, to a lesser degree, active shoulder elevation greatest risk factors for nonunion are age and smoking Rotator cuff injuries and dysfunction Long head of biceps tendon injuries also at risk with anterior pin in CRPP Missed posterior dislocation consider in all patients with lesser tuberosity fracture Adhesive capsulitis and scar tissue Posttraumatic arthritis Infection