What Risks are Associated with Primary THA in Recipients of Hematopoietic Stem Cell Transplantation?

introductionAs patients who receive hematopoietic stem cell transplantation are at increased risk of avascular necrosis (AVN) and subsequent degenerative arthritis, THA may be considered in some of these patients, particularly as overall patient survival improves for patients undergoing stem-cell transplants. Patients receiving hematopoietic stem cell transplantation theoretically are at increased risk of experiencing complications, infection, and poorer implant survivorship owing to the high prevalence of comorbid conditions, immunosuppressive therapy regimens including corticosteroids, and often low circulating hematopoietic cell lines; however, there is a paucity of studies elucidating these risks. QUESTIONS/PURPOSES: We asked: (1) What is the overall mortality of patients with hematopoietic stem cell transplantation who have undergone THA? (2) What is the complication rate for these patients? (3) What are the revision and reoperation rates and implant survivorship for these patients? PATIENTS AND

methodsBetween 1999 and 2013, we performed 42 THAs in 36 patients who underwent stem-cell transplants. Other than those who died, all were available for followup at a minimum of 2 years; of the patients whose procedures were done more than 10 years ago and who are not known to have died, two (5%) had not been seen in the last 5 years and so are considered lost to followup. All patients underwent thorough evaluation by the transplant team before arthroplasty; general contraindications included active medical comorbidities or evidence of unstable end-organ damage, active rejection, and critically low circulating hematopoietic cell lines. Underlying primary diseases leading to hematopoietic stem cell transplantation included lymphoma (14/42; 33%), plasma cell disorders (10/42; 24%), leukemia (9/42; 21%), and amyloidosis (3/42; 7%). Complications, reoperations, revisions, and implant and patient survivorship, were recorded from chart review and data from the institutional total joint registry. Mean followup was 5 years (range, 2-15 years).

resultsPatient survivorship free of mortality was 91% (95% CI, 81%-100%) and 82% (95% CI, 68%-96%) at 2 and 5 years, respectively. Complications occurred in four of 42 THAs (10%); these complications included an intraoperative fracture and a venous thromboembolism. Revisions occurred in two of 42 (5%) THAs; there were no reoperations. Implant survivorship free of component revision for any reason or implant removal accounting for death as a competing risk was 93% (95% CI, 83%-100%) at 5 years.

conclusionWith appropriate medical evaluation and comanagement by transplant specialists, carefully selected patients with hematopoietic stem cell transplants may undergo elective primary THA, although complications do occur in this relatively fragile patient population. Although implant survivorship was modest at 93% at 5 years, there was not a high risk of revision for infection. Improved outcomes for these patients may be expected as their medical management advances and additional comparative studies may clarify other important patient factors. LEVEL OF EVIDENCE: Level IV, therapeutic study.