The morbidity associated with bone-graft harvesting is an important determinant of the indications for its use as well as for the use of bone-graft substitutes. The number of bone-grafting procedures performed annually is estimated to be 1.5 million in the U.S.1,2 and 2.2 million worldwide3,4. Bone-grafting procedures are performed for a wide variety of indications including fusion of the spine and other joints; bone replacement for tumor; infection; periprosthetic bone loss; pediatric bone deficiency; and trauma reconstruction including fracture, nonunion, and traumatic bone loss. Bone autograft provides osteoconductive scaffolding, osteoinductive growth factors, and osteogenic progenitor cells. Autograft has been used for over 100 years to effectively fill bone voids and stimulate desirable bone formation. A variety of sources of bone autograft have been reported but the iliac crest is the most common source, with good quality and quantity of bone graft readily available. Although complications associated with bone-graft harvesting have been reported for years, it was generally considered a safe and reliable procedure until the 1990s, when higher rates of complications began to be reported (as discussed by Loeffler et al.). Younger and Chapman reported a 9% rate of major complications and a 21% rate of minor complications4. Concomitantly, bone-autograft substitutes were developed, including allografts, scaffolds, and growth factors. The availability of effective alternatives and the perceived high rate of donor-site morbidity that could be avoided by use of bone-autograft substitutes led to a huge expansion in the use of these substitutes in orthopaedic procedures5. The number of allograft procedures performed in the U.S. is estimated to have increased from 5000 in 1985 to over 1.5 million in 20062. Bone-grafting (including allografts, other bone-graft substitutes, bone morphogenetic proteins [BMPs], and growth factors) is now a $2.5 billion-a-year industry in the U.S.2,6.
It is very important to determine whether the true rate of morbidity associated with iliac bone-graft harvesting is so high that more expensive alternatives should be preferred. The article by Loeffler et al. specifically includes use of anterior iliac crest cancellous or corticocancellous autografts for trauma reconstruction patients. It specifically excludes use of grafts from other donor sites (such as the posterior iliac crest), structural grafts, and grafts obtained for other indications (tumor, spine fusion, etc.). The specific inclusion and exclusion criteria are a major strength of the report. Other strengths are the adequate number of patients (ninety-two consecutive patients at a single center), appropriate control group for comparison, and reasonable methods for detecting morbidity (visual analog scale [VAS] pain scores at two, six, twelve, and fifty-two weeks; Short Form-36 [SF-36]; and specific surveillance for other complications). The results were statistically and clinically significant. They demonstrated that the average VAS pain score at the donor site was 3.9 (on a scale of 0 to 10) at two weeks, decreased rapidly to 1.4 at six weeks, and reached 0.3 at one year (p < 0.001); only 2% reported a VAS pain score of >3 at one year. The rate of other complications was 3% (all infections), no patients had a permanent sensory deficit in the lateral femoral cutaneous nerve distribution, only 10% reported any degree of alteration in skin sensation at one year, and cosmetic disturbance was minimal. The two specific techniques utilized (trap door cancellous and inner table corticocancellous harvesting) gave equivalent results. The SF-36 results indicated better results in the patients treated with bone autograft compared with the controls, indicating the efficacy of the procedure as well as its low morbidity.
The 2% rate of moderate pain is markedly less than those in many other reports on pain after iliac autograft use that have been published in the past twenty years, which often ranged from 15% to 25%. The authors appropriately limit their discussion to the efficacy and low morbidity of their anterior iliac crest bone-graft harvesting site and technique used for trauma reconstruction indications. Harvesting of autograft from other sites (posterior iliac crest or other) or by other methods (structural or tricortical grafts) was not studied and might give different results. Grafts obtained for other indications (spine fusion in particular) might give different results.
This article reports such a low rate of substantial pain (2% at one year) after anterior iliac crest bone-graft harvesting for trauma reconstruction that the indications for use of allograft and other bone-graft substitutes must be seriously reconsidered and perhaps limited to special situations. If this rate is substantiated by other surgeons, the anterior iliac bone-autograft donor site may regain its position as the gold standard for stimulating bone formation in trauma reconstruction cases. This has implications for and applicability to a wide range of orthopaedic subspecialists and their patients.