Blinded Outcome Assessment Versus Operating Surgeon's Evaluation of Chronic Iliac Donor Site Pain

Robert F. Heary, MD
Richard P. Schlenk, MD
Theresa Sacchieri, BS
Dean Barone, PA–C

A common criticism against the use of autologous iliac bone is the morbidity associated with pain from the donor site. The purpose of this study is to define the true incidence of donor site pain following iliac bone harvesting. The presence of long term donor pain, when specifically addressed by a single neurosurgeon's evaluation, was compared with a blinded assessment obtained by a structured telephone questionnaire interview. Over a four–year period, 105 patients met inclusion criteria who had both operating surgeon and blinded interviewer follow–up. The senior neurosurgeon personally harvested all iliac grafts and performed all postoperative evaluations of iliac pain. In the telephone questionnaire, pain was classified into 3 categories: no pain, acceptable pain, or unacceptable pain (as defined by the patient).

One hundred–five patients (males–55, females–50, mean age–46) were evaluated, of which 66 had anterior, 18 posterior, and 21 combined AP approaches. At a mean duration of 12 months follow–up, the operating surgeon documented no pain in 97 patients (92%), acceptable pain in 7 patients (6.6%), and unacceptable pain in 1 patient (0.9%). At a mean duration of follow–up of 19 months, the blinded interviewer recorded no pain in 70 (67%), acceptable pain in 32 (30%), and unacceptable pain in 3 patients (3%). This difference was found to be statistically significant (P> 0.0001). When evaluated at a time remote from their surgery, the true incidence of iliac donor site pain following graft harvest procedures (33%) was significantly greater than previously appreciated by their neurosurgeon (6%). While occasional or mild pain, deemed to be acceptable by patients, occurred in 30% of patients, only 3% of all patients had unacceptable pain. The blinded outcome assessment figures should be quoted to patients in preoperative discussions regarding donor site morbidity. In conclusion, objective outcome analysis by blinded observation is crucial in determining the most accurate interpretation of the perception of iliac pain.