summary Shoulder Periprosthetic Fractures are intraoperative or postoperative complications associated with shoulder arthroplasty that can lead to loosening and migration of the prosthesis. Diagnosis can be made with plain radiographs of the shoulder and humerus. CT scan can help identify loosening of the prosthesis. Treatment involves ORIF or revision shoulder arthroplasty depending on location of the fracture and stability of the prosthesis. Epidemiology Incidence 0.6-3% of patients with TSA Demographics typically occurs in patients 50-85 years of age Timing of onset most fractures often occur intraoperative at the time of the original implant consists of 20% of all complications Anatomic location adjacent to the prosthetic stem tip greater tuberosity most commonly occurs during revision total shoulder arthroplasty Risk factors soft tissue contractures osteoporosis endosteal notching aggressive reaming incorrect entry reaming site ideal entry reaming site is 9 mm lateral from anatomic center of rotation use of press fit humeral stems compared to cemented stems revision arthroplasty cases history of instability female sex post-traumatic arthritis increased comorbidity index osteonecrosis corticosteroid-induced > alcohol and post-traumatic Etiology Pathophysiology intraoperative fractures occur most often during revision total shoulder arthroplasty greater exposure required during these procedures increased scarring in the subacromial space and around the rotator cuff login to view 1 more bullet removing previous implant (up to 81% of intraoperative fractures) login to view 9 more bullets other mechanisms of intraoperative fractures: login to view 4 more bullets primary total shoulder arthroplasty has a lower risk for intraoperative fracture login to view 5 more bullets post-operative fractures can occur as a result of a fall or fatigue fracture through a stress riser fall on outstretched hand login to view 2 more bullets atraumatic due to prosthetic loosening login to view 1 more bullet high risk of nonunion prosthesis disrupts endosteal blood supply impairing fracture revascularization and healing prosthetic stem distracts the two fragments preventing end-to-end healing Associated conditions nonunion osteoporosis RA female sex displacement >2 mm presence of cement at fracture site Classification Wright and Cofield Classification Type A Fracture centered near the tip of the stem and extends proximally Type B Fracture centered near the tip of the stem and extends distally Type C Fracture located distal to the tip of the stem. Presentation History mechanical fall fall on out-stretched hand worsening arm pain present with mechanical loosening of the prosthesis Symptoms common symptoms acute pain in the upper arm login to view 1 more bullet gross deformity Physical exam inspection varus or valgus deformity ecchymosis & swelling shortening of the affected arm diffuse tenderness of the upper arm motion patient may not be able to move affected elbow or shoulder login to view 1 more bullet neurovascular examine for radial nerve status login to view 2 more bullets document full neurological and vascular findings Imaging Radiographs orthogonal radiographs of the affected humerus AP, axillary lateral, Grashey, scapular Y views findings fracture involving the prosthetic stem tip login to view 1 more bullet criteria dictating treatment appearance of stem stability zones of lucency around stem login to view 1 more bullet CT indications concern for loose prosthesis login to view 2 more bullets comminution perform with metal suppression protocol decreased artifact from prosthesis assessment: determine fracture morphology assess remaining bone stock quality of the rotator cuff muscle version of the glenoid if revision is determined necessary Treatments Nonnoperative treatment immobilization indications login to view 2 more bullets outcomes: login to view 1 more bullet Operative treatment conversion to prosthetic stem spanning fracture site by two cortical diameters indications login to view 1 more bullet conversion to proximally porous coated long stem prosethesis spanning fracture site by two to three cortical diameters indications login to view 2 more bullets open reduction and internal fixation indications login to view 6 more bullets revision arthroplasty with supplementary fixation indications login to view 1 more bullet long stem prosthesis login to view 2 more bullets short stem prosthesis login to view 2 more bullets Techniques Immobilization coaptation splint followed by functional bracing hydrostatic pressure created by brace stabilizes fracture site higher risk of nonunion with type A and B fractures Conversion to prosthetic stem spanning fracture site by two cortical diameters removal or original stem placement of longer stem engages distal fragment and improves fracture alignment +/- supplementary fixation depending on fracture stability Conversion to proximally porous coated long stem prosethesis spanning fracture site by two to three cortical diameters proximal porous coating allows for metaphyseal stability distal fragment cemented to stem tip techniques: pack cement into the distal canal to allow for distal stem fixation avoid proximal cement extrusion into fracture site use cortical strut grafting with cerclage cables in cases of bone deficiency olecranon fossa may prevent successful treatment with this method Open reduction and internal fixation techniques: approaches: login to view 16 more bullets greater tuberosity and calcar fractures suture or cable fixation hydbrid locking plates with cerclage cables have been used for postoperative fractures plate placed eccentrically on humerus to allow locking screws to miss humeral stem login to view 1 more bullet use of cerclage cables for added stability alternatively can use dual plate constuct or 3.5 mm attachment plates for bicortical fixation can combine with allograft augmentation for fractures with deficient cortices can use cortical strut allograft and fix with cerclage cables login to view 1 more bullet Revision arthroplasty with supplementary fixation type of revision prosethesis is dependent on the quality of bone stock poor bone stock login to view 3 more bullets good bone stock login to view 4 more bullets Complications Nonunion Delayed union Glenohumeral stiffness Radial nerve injury can be secondary from the fracture iatrogenic from fixation with cerclage cables instrumentation proximal to the inferior edge of the latissimus dorsi insertion may reduce the risk of iatrogenic radial nerve injury Prognosis High union rates when appropriately treated time to union 2-8 months Significant decrease in shoulder ROM