PERIPROSTHETIC HUMERAL FRACTURES - MECHANISMS OF FRACTURE AND TREATMENT OPTIONS

In 20 patients, 21 periprosthetic humeral fractures were reviewed retr ospectively. The mean follow-up time was 27.1 months. Mild osteopenia was present in 45% of the patients, whereas 30% had severe osteopenia. Five mechanisms of fracture were identified including 3 intraoperativ e causes that are avoidable. Treatment with stable intramedullary fixa tion utilizing the humeral stem and cerclage wiring provided superior results in terms of time to union, adverse effect on rehabilitation, a nd occurrence and severity of surgical complications. Diaphyseal fract ures that were treated with standard stem arthroplasty with or without supplemental fixation had a longer time to fracture union, a higher c omplication rate, and prolonged rehabilitation. Fractures of the proxi mal humeral metaphysis can be created with standard stem arthroplasty and cerclage wiring if the stem extends distal to the fracture site by at least 3 cortical diameters. Anatomic reduction of fractures treate d by surgical means results in shorter healing times. Cast or brace im mobilization can be used For management of postoperative fractures tha t occur distal to a well-fixed and stable prosthetic stem. Cast or bra ce immobilization results in fracture union but rehabilitation may be greatly impaired, and there is an increased risk of complications asso ciated with immobilization of the extremity long-stem intramedullary f ixation with cerclage wiring is the preferred surgical option for trea tment of unstable humeral shaft fractures.