Bone grafting is a commonly used surgical procedure, particularly in reconstructive orthopaedic surgery. Bone graft may be used to fill skeletal defects created by tumors, infections, trauma, or congenital malformations; to bridge joints for arthrodesis; to provide a bony block to joint motion (arthrodesis); or to promote union at the site of delayed union, nonunion, fracture, or osteotomy.1,13,17,26,27,30,47 Options for graft include autograft, cadaveric allograft, xenograft, and synthetic substitutes.1,13,17-19,26,27,34,47 Although the other options have some advantages, autologous cortical and cancellous bone are the most commonly used graft materials.17
The advantages of autologous bone include its osteoinductive and osteoconductive properties.17,21,26,42,47,51 Additionally, autologous bone is histocompatible and nonimmunogenic,2,25,26,34,42,49 and is usually well incorporated into the graft site. The use of autograft bone also eliminates the potential risk of transplanting infectious disease, as has occurred with allografts.4,7,17,19 The disadvantages of autogenous bone graft include limited volume of cancellous bone,22,25 increased operative time,1,26 increased blood loss,1,26 temporary disruption of normal donor site bone structure,26 and donor site morbidity.9,20,31-33,35,54
Although autologous bone can be harvested from the tibia, fibula, olecranon, distal radius, and ribs, the iliac crest remains the most common donor site.8,17,19,22,26,35 Bone graft can be obtained from the anterior or posterior aspect of the iliac crest, making it accessible from virtually any patient position.22 In general, after harvesting of autogenous bone from the iliac crest, iliac wing structure and patient function are not significantly impaired. In addition, significant amounts of bone graft are available with cancellous volume averaging 12.87 ml anteriorly and 30.31 ml posteriorly.22
Despite the frequent use of the iliac crest site, there are few reports of complications from this procedure. The purpose of this study was to review 414 consecutive iliac crest bone graft harvesting procedures performed at Brooke Army Medical Center, Fort Sam Houston, Texas.
MATERIALS AND METHODS
The purpose of this study was to retrospectively review 414 consecutive cases of iliac crest bone graft harvesting procedures performed at Brooke Army Medical Center from 1983 to 1993. Procedures were performed by either the Orthopaedic Surgery or the Oral-Maxillofacial Reconstructive Surgery Services. Inpatient and outpatient records were available for all patients from this period and were reviewed for minor and major complications associated with the harvesting of the iliac crest bone graft. Radiographs of all identified complications also were reviewed. Minor complications were defined as those events that did not necessitate a return to the operating room and that responded to nonoperative intervention, including aspiration, dressing changes, and oral antibiotics. Minor complications resolved with aggressive nonoperative treatment in a timely manner. Major complications were defined as those events that required a major change in treatment or return to the operating room and that subsequently necessitated an unexpectedly prolonged hospital stay. Chronic donor site pain lasting for more than 6 months could not be reliably identified in the retrospective review and was, therefore, not addressed in the present series.
Minor complications were defined as those events that responded to aggressive nonoperative intervention, including aspiration, dressing changes, and oral antibiotics. There were 41 (10%) minor complications identified during the study period. These minor complications included 5 superficial infections, 20 superficial seromas, and 16 minor hematomas. (Table 1) All 5 patients with superficial infections were appropriately treated as outpatients with oral antibiotics and local wound care. The 20 patients with superficial seromas and 16 patients with minor hematomas were treated with aspiration and drainage or local wound care and did not require operative intervention for resolution.
There were 24 (5.8%) major complications identified during the study period. These major complications needed either a major change in treatment, prolonged hospitalization, or a return to the operating room. These major complications included 2 donor defect hernias, 3 vascular injuries, 6 nerve injuries, 7 deep infections, 4 deep hematomas, and 2 iliac wing fractures (Table 2). Detailed analysis of each of the major complications was performed, including reviews of inpatient and outpatient records, operative reports, and radiographs.
Two patients had similar postoperative courses after undergoing massive anterior tricortical bone graft harvesting for facial reconstructive surgery. Both patients did well initially after operation, but subsequently complained of vague lower abdominal pain. Physical examination showed a fullness over the bone graft site, and bowel sounds were auscultated. Plain radiographs suggested, and computed axial tomographic scans confirmed, small bowel herniation through the donor defect (Fig 1). Both patients underwent manual reduction of the hernia without reconstruction of the defect. No evidence of bowel incarceration or episodes of bowel obstruction has developed in either patient.
Three cases of injury to vascular structures were identified. All 3 cases occurred secondary to harvesting of posterior iliac crest bone grafts. In 2 cases, injury to the superior gluteal artery was identified intraoperatively. In a third case, arteriographic proof of a superior gluteal artery laceration was obtained after operation (Fig 2). A retractor in the sciatic notch was used on each of these 3 cases.
In the first case, a 14-year-old boy was undergoing posterior iliac crest bone graft harvesting for treatment of a bone cyst. An arterial laceration was identified intraoperatively in the sciatic notch. The laceration was localized and ligated after a blood loss of approximately 700 cc. The patient required a transfusion of 2 units of blood, but had no other sequela from this episode.
In the second case, a 45-year-old obese man had sustained a lumbar burst fracture in the crash of an ultralight airplane. The patient had an uncontrollable and significant recurrent bleeding episode from the bone graft site immediately after operation, which required reoperation to isolate and then to ligate the bleeding vessel. The patient required a transfusion of 4 units of blood after this event, but died 1 week later of complications from a gangrenous gallbladder.
In the third case, a posterior iliac crest bone graft was harvested to supplement a posterior cervical fusion. After operation, the patient was noted to have an enlarging hematoma at the graft site. An arteriogram was obtained, which identified the superior gluteal artery laceration (Fig 2). Embolization with gelfoam was unsuccessful, and reoperation was necessary to ligate the vessel. A deep infection subsequently developed in the patient, who responded to evacuation, debridement, and intravenous antibiotics.
There were 6 cases of neurologic injuries diagnosed in this series. Three patients had constant burning pain, hypersensitivity along the anterolateral thigh, and discomfort wearing a belt after anterior iliac crest harvest (Fig 3). Infiltration about the lateral femoral cutaneous nerve with local anesthetic resulted in temporary relief, confirming the diagnosis of meralgia paresthetica. Additionally, there was no noted association between the location of the surgical incision and the development of postoperative lateral femoral cutaneous nerve symptoms. These patients required no further operative treatment, because desensitization modalities resulted in moderate pain relief. No association was noted between the surgical site and the lateral femoral cutaneous nerve symptoms.
Three patients complained of tenderness and burning pain in the buttocks, especially pronounced with sitting, after posterior iliac crest bone graft harvest for posterior spinal fusion. Radiating pain into the buttocks was reproduced with percussion about the graft site. Desensitization modalities were unsuccessful, and after local anesthetic localization, repeat surgical explorations showed neuromas of the superior cluneal nerves. All 3 superior cluneal nerve neuromas were noted in cases where postiliac crest bone graft harvesting was performed greater than 8 cm from the posterior superior iliac spine (Fig 4). These 3 neuromas were excised, allowing the nerve stump to retract into the lumbosacral dorsal fascia. All 3 patients improved, but 1 patient has continued to complain of mild persistent pain and burning symptoms.
Infection and Hematoma
There were 7 deep infections and 4 deep hematomas that required reoperation. The deep infections all responded to operative debridement and irrigation and to a culture directed course of intravenous and oral antibiotics. There was no correlation noted between operative technique, hosts, and the development of a deep postoperative infection. There were no cases of osteomyelitis identified.
There were 4 deep hematomas that required reoperation. Initially, none of these 4 cases of deep hematoma formation had bone wax applied to the exposed cancellous surface, and none were closed over suction drains. The deep hematomas eventually resolved with surgical evacuation, irrigation, debridement, and postoperative suction drainage. Intraoperative cultures in these cases during the hematoma evacuation were negative.
Two cases of pelvic iliac wing fracture after anterior iliac crest harvest were identified. The first case involved a 71-year-old woman with significant persistent postoperative pain about her anterior iliac crest graft site. No intraoperative complications were noted. Postoperative radiographs showed a nondisplaced fracture of the iliac wing. The patient was treated nonoperatively, and the fracture site healed without sequela.
The second case involved a 57-year-old woman with severe rheumatoid arthritis who required autogenous bone grafting during a wrist fusion. During the anterior iliac bone graft harvesting, an audible crack was heard, but initial radiographs did not show a fracture. After operation, however, the patient continued to complain of pain about the iliac crest bone graft site, and repeat radiographs showed a displaced fracture of the anterior superior iliac spine. The fracture was treated nonoperatively, and although the patient had considerable pain with ambulation at first, she has progressed to a painless fibrous union (Fig 5). Harvesting of anterior iliac crest bone grafts in both cases was noted to be too close to the anterior superior iliac spine, thereby causing the fracture of the anterior superior iliac spine from the iliac wing.
The use of bone graft dates back to the work of Ollier and Barth in the 1800s, although in the early 1900s, Axhausen was the first to study its use scientifically.8,19 Urist51 most effectively shows the utility of autologous bone, describing its osteoinductive and osteoconductive properties. With inherent advantages over other options, the use of autologous bone from the iliac crest has been commonly used since the turn of the century.2,7,8,17-19,21,22,25,34,42,47,49,51 However, although documented complications in the literature are scant, there is significant morbidity associated with the harvest of bone from the iliac crest.1,9,15,20,31-33,35,55
Cockin9 reviewed 118 cases of iliac crest bone grafts and found minor complaints such as wound pain, wound hypersensitivity, and buttock anesthesia in 6% of cases. He reported a 3.4% incidence of major complications, including meralgia paresthetica, subluxation of the hip after extensive removal of the iliac crest, and 1 case of herniation through the bone graft donor site (the contents of the hernia were not specified). Younger and Chapman55 reported an overall major complication rate of 8.6% after 243 bone grafts from various sites, although 90% were from the iliac crest. Other authors have compared the morbidity of iliac crest harvest with rib grafts35 or spinous process grafts.30
Perhaps the most dramatic complication associated with harvesting of iliac crest bone graft is herniation of abdominal contents through the donor defect. This is a rare complication, however, with more than 20 cases reported in several small series and case reports3,5,6,12,16,23,24,29,37,40,41,43,50 in the literature. Hernias are associated exclusively with tricortical harvests.33 Full thickness grafts require detachment of the abdominal wall musculature from the inner and outer tables of the ilium, and this detachment may cause weakness in the wall, thereby increasing the chance of small bowel herniation through the defect.33 Symptoms usually include abdominal pain and a mass with bowel sounds, and the diagnosis is confirmed with a computed tomography scan.29 Incarceration, volvulus, and strangulation of the small bowel have been reported.6,12 In addition, presentation has even been reported as late as 15 years after the graft harvest.12
Historically, the treatment of these hernias has been surgical. Repair with the local soft tissues, with or without supplementation using soft tissue or synthetic material, has been advocated.3,5,7,16,29,40,41,43 Avoiding massive tricortical iliac crest bone grafts, harvesting the bone through a trap door or subcrestal window, and preserving the attachment of the abdominal musculature by obliquely sectioning the top of the crest and then carefully repairing it are techniques that have been advocated to prevent herniation.26,41 No hernias have been reported with subcrestal windows. Hochschuler et al24 recommended prophylactic reconstruction of the crest defect with a synthetic substitute at the time of harvest (Proplast-Vitek, Inc, Houston, TX). Methylmethacrylate has been suggested for use to fill these defects.6 Others advocate avoiding full thickness grafts altogether, especially in the region of the inferior lumbar triangle (Pettit's triangle), because this area is particularly prone to hernia formation.5,12,26,37
Vascular injury involving the superior gluteal artery or 1 of its branches is preventable. The superior gluteal artery is a branch of the internal iliac artery and is in danger as it exits the pelvis to enter the gluteal region through the superior aspect of the sciatic notch.1,26,33 Injury typically results from an improperly placed retractor or an uncontrolled plunge with a periosteal elevator or osteotome.28 If lacerated completely, the artery may retract into the pelvis and may not be apparent until significant blood loss has occurred.26 Kurz et al32,33 reported 3 cases of superior gluteal artery injury that necessitated bone removal from the sciatic notch to expose the retracted arterial stump. Escalas and Dewald14 reported the creation of a traumatic arteriovenous fistula and ureteral injury after the inadvertent placement of a Taylor retractor. The 3 vascular injuries in the present series are similar to these reports in that all were the result of technical errors secondary to the placement of a Taylor retractor in the sciatic notch.
Nerve injuries have been associated with harvesting both anterior and posterior iliac crest bones. The lateral femoral cutaneous nerve is a sensory branch of the lumbar plexus, supplying sensation to the lateral aspect of the thigh. It usually passes into the thigh below the inguinal ligament just medial to the anterior superior iliac spine (Fig 3). However, it may pass over the crest as much as 2 cm lateral to the anterior superior iliac spine, placing it at risk during anterior iliac crest bone harvest, either from a poorly placed incision or overzealous retraction.32,33,38,46 Once established, the treatment of meralgia paresthetica is difficult,38,54 although the present cases partially responded to conservative nonoperative measures.
The cluneal nerves, branches of the L1, L2, and L3 dorsal rami, supply sensation to the buttocks.1,26,32,33 These superficial sensory nerves pass over the iliac crest posteriorly 8 cm from the posterior superior iliac spine. The cluneal nerves may be lacerated or stretched during posterior iliac crest bone graft harvests1,26,32,33(Fig 4). If injured, transient paresthesias ensue, which usually resolve spontaneously.10,32,33 Injury to these nerves can be avoided if dissection remains within 8 cm of the posterior superior iliac spine along the posterior iliac crest.10,13,22,26,32,33 Initial treatment should be conservative. However, if symptoms persist, consideration should be given to exploration and excision of the neuromas.1,10,32,33 Despite aggressive nonoperative intervention and desensitization modalities, the present cases remained symptomatic and required neuroma excision.
The ilioinguinal, sciatic, superior gluteal, and femoral nerves are potentially at risk during iliac crest bone graft harvest.33 Ilioinguinal neuralgia has been reported, although the authors have no experience with this syndrome of pain and paresthesias in the distribution of the ilioinguinal nerve.45 There are no reported cases of sciatic nerve injury from posterior iliac crest bone graft harvest, but the sciatic nerve is at potential risk as it exits the pelvis to enter the gluteal region through the inferior sciatic notch.33 There are no reported cases of superior gluteal nerve injury, but it also is at risk as it exits the pelvis in the superior aspect of the sciatic notch adjacent to the superior gluteal artery.33 In addition, although there are no reported cases of femoral nerve injury, its position overlying the iliacus muscle in the iliac fossa places it at risk during harvesting of bone graft from the inner table of the anterior ilium.33
Postoperative deep infection requiring surgical intervention has been reported to occur in less than 1% of cases.1,26,27,33,39 Infection usually results from improper technique, particularly in immunocompromised or nutritionally depleted hosts.1,33 Treatment of postoperative deep infections requires incision, drainage, irrigation, debridement, and a course of culture-directed intravenous and oral antibiotics.33
Hematoma formation results from inadequate intraoperative hemostasis, improper subperiosteal dissection, or cancellous bone bleeding.33 The incidence of deep hematoma formation after iliac crest bone graft harvest has been reported to range from 2% to 9%.33 Watkins52 recommends the use of a thin layer of bone wax on the cut surface of the iliac crest donor site to decrease postoperative cancellous bone ooze. The use of a closed suction drain has long been advocated in orthopaedic procedures.53 Although Younger and Chapman55 found a higher complication rate after the use of a suction drain after iliac crest bone graft harvest, the authors still recommended its use. Including all identified major and minor infections and hematomas, the present infection rate of 2.90% and hematoma rate of 4.83% are consistent with the reported complication rates. In addition, there was no noted or increased incidence of complications secondary to the use of suction drains.
Disruptions of the pelvic ring and fractures after iliac crest bone graft harvesting are rare.33 Coventry and Tapper11 reported a series of 6 patients in whom sacroiliac instability developed after bone graft harvesting of the posterior iliac crest. Likewise, Lichtblau36 reported a case of sacroiliac joint disruption secondary to posterior iliac crest bone graft harvest. Both authors postulate that the sacroiliac ligaments were probably inadvertently damaged during posterior iliac crest bone graft harvesting, resulting in the instability. There were no identified cases of posterior pelvic instability after posterior iliac crest bone graft harvest in the present series. Reynolds et al44 and Ubhi and Morris50 have reported pelvic iliac wing fractures after anterior iliac crest bone graft harvest. Both of the present fractures followed anterior iliac crest bone graft harvest, and although 1 healed with a fibrous union, both patients have had no other unfavorable results. A review of both cases documented anterior iliac crest bone graft harvesting too close to the anterior superior iliac spine, predisposing the patients to a fracture of the anterior superior iliac spine from the iliac wing.
Finally, chronic pain at the bone graft donor site has been reported by several authors as a complication of iliac bone graft harvesting.9,15,31-33,35,48,55 The incidence of chronic donor site pain is reported to range from 6% to 39% in a subgroup of patients who underwent bone grafting as part of a spinal reconstructive procedure.9,48 Controversy persists as to whether the use of the primary surgical incision or a secondary incision for the bone graft harvest results in a higher rate48 or no difference in the rate15 of chronic pain. Chronic donor site pain lasting for more than 6 months could not be reliably identified in this retrospective review and was, therefore, not addressed in the present series.
The use of autologous iliac crest bone graft is common in trauma and reconstructive orthopaedic surgeries. It is both efficacious and available in quantities sufficient for most applications. However, there can be significant associated morbidity. Until suitable proven alternatives are found, it is imperative that surgeons remain aware of the regional anatomy and use proper techniques to minimize this morbidity.
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