Skeletal Radiol (2015) 44:1453–1459 DOI 10.1007/s00256-015-2189-2
SCIENTIFIC ARTICLE
Unexpected radiographic lucency following grafting of bone defects with calcium sulfate/tricalcium phosphate bone substitute Darryl A. Auston 1 & Matthew Feibert 2 & Tina Craig 3 & Timothy A. Damron 3
Received: 19 January 2015 / Revised: 27 May 2015 / Accepted: 2 June 2015 / Published online: 17 June 2015 # ISS 2015
Abstract Objective To report the development of unexpected radiographic lucency (URL) corresponding to the use of a commercially available calcium sulfate/tricalcium phosphate composite used to treat benign osseous lesions. Materials and Methods This is a retrospective comparative study of patients with and without URL after treatment with curettage and grafting with calcium sulfate/tricalcium phosphate. The charts of 87 patients meeting the inclusion criteria were reviewed for demographic, clinical, and radiographic data. The group with URL was compared to those with more typical patterns of graft incorporation. Results Thirteen of 87 cases (15 %) showed URL. There was no difference with respect to the pathologic subtype, anatomic location, or specific bone for the presence of URL. Of patients with URL, one (7.7 %) required reoperation and regrafting, whereas among patients without URL, five (6.7 %) had clinical complications, with one requiring reoperation and regrafting, and one requiring radiofrequency ablation. Conclusions The majority of patients treated with calcium sulfate/tricalcium phosphate cementing after curettage of low-grade bone lesions go on to uneventful healing in our series. In a minority of patients, URL occurs in lieu of the more typical pattern of centripetal incorporation. However, there is no increase in complications associated with URL. Based on these findings, patients should be informed of the possibility of * Timothy A. Damron [email protected] 1
Department of Orthopedic Surgery, State University New York Upstate Medical University, Syracuse, NY, USA
2
Syracuse University, Syracuse, NY, USA
3
Upstate Orthopedics, East Syracuse, NY, USA
this risk, although there appears to be little risk of clinically relevant adverse consequences. Physicians should be aware of this complication in order to avoid mistaking it for recurrence of the primary lesion. Keywords Synthetic bone graft . ProDense . Calcium sulfate . Tricalcium phosphate . Curettage and grafting . Complications of synthetic bone graft
Introduction Low-grade osseous lesions can be treated with intralesional resection with bone grafting of the resulting cavitary defect. Autologous bone is the gold standard material for grafting of these cavitary lesions. However, donor site morbidity is a side effect not uncommon to these procedures [1–4]. Allograft bone can be used, but disease transmission is a risk that must be considered [5–7]. Synthetic bone graft substitutes have been developed to obviate the risks and complications associated with auto- and allograft bone. Synthetic materials do not represent a panacea for complications related to bone grafting of cavitary defects. Some materials, such as calcium sulfate, are known to resorb more quickly than bony ingrowth can occur [8–12], whereas materials such as calcium hydroxyapatite can remain indefinitely [13, 14]. We have previously reported on the efficacy of bony incorporation of an ultraporous beta-tricalcium phosphate graft that appears related to lesion size, with some synthetic graft material persisting up to a year in larger lesions [15]. Another available synthetic bone graft substitute is a combination of calcium sulfate and beta-tricalcium phosphate (Pro-Dense, Wright Medical Technology, Inc., Memphis, TN). The rationale for the use of this product has been that the relatively rapid dissolution of the calcium sulfate within
1454
the composite would leave a more porous tricalcium phosphate, which would potentially allow for more optimal bone ingrowth. Studies have shown that graft resorption occurs in a typical centripetal pattern with osseous replacement of the graft proceeding beginning at the outer rim of the graft and continuing inward [16, 17]. Currently underway is an ongoing prospective clinical study comparing the results of this calcium sulfate/tricalcium phosphate graft and ultraporous betatricalcium phosphate in treating cavitary defects created in the treatment of low-grade neoplasms and other benign bone lesions (for the purposes of this study Bbenign osseous lesions^ is used for simplicity). Over the course of this study we have observed in some patients a deviation in the expected radiographic appearance of the calcium sulfate/tricalcium phosphate graft during the postoperative phase. Rather than the typical centripetal resolution of the graft, we have observed the appearance of an unexpected radiographic lucency (URL) in the area of the graft that seemed unrelated to recurrence of the original lesion. To date, this observation has not been reported. This work is intended to describe URLs in patients treated with the calcium sulfate/tricalcium phosphate bone graft substitute and analyze patient and primary lesion factors associated with their occurrence.
Materials and Methods This work is a retrospective comparative study of patients treated by the senior author with curettage and grafting using calcium sulfate/tricalcium phosphate during a 5-year period from December 2007 to December 2012 for benign osseous lesions. Patients with URL after treatment are compared to patients without these changes. This study was approved by the Institutional Review Board. One hundred eight consecutive patients received curettage and grafting with calcium sulfate/tricalcium phosphate during this time period and were eligible for inclusion in the study (Fig. 1). Of these, 21 were excluded for the following reasons: receiving graft for osteolysis related to prosthetic joints (11 patients), receiving a graft for a lesion other than a benign osseous lesion or cyst (1 patient), or inability to locate any radiographs (9 patients). Patients with radiographic evidence of an osseous lesion were evaluated by the senior author. Evaluation included patient history and clinical examination followed by review of relevant diagnostic imaging. Initial presumptive clinical diagnosis was made based on the history and appearance of the lesion on imaging. The clinical diagnosis was further evaluated by biopsy in all of the reported cases. Biopsy material in many cases was reviewed immediately at the time of surgery by frozen section by the senior author and pathologists and later confirmed by review of permanent sections by the pathology department. Most lesions underwent curettage and
Skeletal Radiol (2015) 44:1453–1459
grafting by the senior author. After open curettage of the lesion, the graft material was prepared according to the manufacturer’s instructions, delivered via syringe and a large bore bone marrow aspiration needle, and packed digitally to completely fill the defect. Excess graft material was removed from the surrounding soft tissues. In the case of simple bone cysts (SBCs), a percutaneous technique was used in two of the cases. An open technique was used for the other SBCs for the following reasons: when biopsy was required to confirm diagnosis, when prophylactic fracture fixation was deemed necessary, or when previous means of injection had failed. Prophylactic stabilization was accomplished in selected cases with either plate and screw constructs or intramedullary devices as deemed necessary by the senior author. Typically for upper extremity lesions, the patient was restricted from sports, upper extremity weights, and throwing (for the dominant extremity) for at least 6 weeks postoperatively and then allowed to progress as tolerated to full activities thereafter. For lower extremity lesions, we recommended crutches and partial weight bearing for 4 to 6 weeks postoperatively, and then the patient was allowed to progress as tolerated gradually to return to full activities over the ensuing several weeks. However, impact activities such as running, jumping, and contact sports were generally not recommended until 3 months postoperatively. Charts of the 87 patients meeting the inclusion criteria were reviewed for demographic and clinical data including lesion type, size, and location, volume of the graft used, type of stabilization if used, recurrence of disease, and reoperation. Radiographs were reviewed for URL and perilesional fracture. Unexpected radiographic lucencies were defined as deviation from the expected centripetal absorption of the calcium sulfate/tricalcium phosphate graft. When available, computed tomography (CT) scans were reviewed to confirm the deviation from expected behavior. Clinical relevance in either group was determined to be recurrence of disease, perilesional fracture, or reoperation. Patients were typically followed up with clinical examinations and postoperative surveillance radiographs at approximately 6 weeks, 3 months, 6 months, and 1 year routinely. Average follow-up for patients in the normal centripetal resolution group was 59.5 weeks (range of 7–171). Patients with evidence of URL were followed more closely once changes were identified. Patients from the group with URLs had their time of follow-up divided up into time to appearance of the lucency, with a mean 26.9 weeks (range 9–52 weeks), and time following identification of the lucency, with a mean 51 weeks (range 0–111 weeks). Overall mean length of follow-up post-surgery in the URL group was 77.46 weeks (range 19–163 weeks). Of those 74 patients who had undergone curettage and grafting with normal radiographic progression, 38 (51 %) were followed for at least 1 year, the latest time point at which the unexpected lucency occurred.
Skeletal Radiol (2015) 44:1453–1459
1455 Treated with calcium sulfate/tricalcium phosphate (n=108)
Excluded (n=21) Received gra for osteolysis related to prosthec joints (n=11) Inability to locate radiographs (n=9) Received gra for other than low grade lesion (n=1)
Included in study (n=87)
No nexpected radiographic lucency (n=74)
No complicaon (n=69)
Unexpected radiographic lucency (n=13)
Complicaon (n=5) Fracture (n=1) Recurrence of disease (n=4)
No complicaon (n=12)
Complicaon (n=1) reoperaon
Fig. 1 Flow chart showing the study design
For gender, anatomic location, and underlying pathological diagnosis, a Fisher exact test was used to test for statistical significance at p
SCIENTIFIC ARTICLE
Unexpected radiographic lucency following grafting of bone defects with calcium sulfate/tricalcium phosphate bone substitute Darryl A. Auston 1 & Matthew Feibert 2 & Tina Craig 3 & Timothy A. Damron 3
Received: 19 January 2015 / Revised: 27 May 2015 / Accepted: 2 June 2015 / Published online: 17 June 2015 # ISS 2015
Abstract Objective To report the development of unexpected radiographic lucency (URL) corresponding to the use of a commercially available calcium sulfate/tricalcium phosphate composite used to treat benign osseous lesions. Materials and Methods This is a retrospective comparative study of patients with and without URL after treatment with curettage and grafting with calcium sulfate/tricalcium phosphate. The charts of 87 patients meeting the inclusion criteria were reviewed for demographic, clinical, and radiographic data. The group with URL was compared to those with more typical patterns of graft incorporation. Results Thirteen of 87 cases (15 %) showed URL. There was no difference with respect to the pathologic subtype, anatomic location, or specific bone for the presence of URL. Of patients with URL, one (7.7 %) required reoperation and regrafting, whereas among patients without URL, five (6.7 %) had clinical complications, with one requiring reoperation and regrafting, and one requiring radiofrequency ablation. Conclusions The majority of patients treated with calcium sulfate/tricalcium phosphate cementing after curettage of low-grade bone lesions go on to uneventful healing in our series. In a minority of patients, URL occurs in lieu of the more typical pattern of centripetal incorporation. However, there is no increase in complications associated with URL. Based on these findings, patients should be informed of the possibility of * Timothy A. Damron [email protected] 1
Department of Orthopedic Surgery, State University New York Upstate Medical University, Syracuse, NY, USA
2
Syracuse University, Syracuse, NY, USA
3
Upstate Orthopedics, East Syracuse, NY, USA
this risk, although there appears to be little risk of clinically relevant adverse consequences. Physicians should be aware of this complication in order to avoid mistaking it for recurrence of the primary lesion. Keywords Synthetic bone graft . ProDense . Calcium sulfate . Tricalcium phosphate . Curettage and grafting . Complications of synthetic bone graft
Introduction Low-grade osseous lesions can be treated with intralesional resection with bone grafting of the resulting cavitary defect. Autologous bone is the gold standard material for grafting of these cavitary lesions. However, donor site morbidity is a side effect not uncommon to these procedures [1–4]. Allograft bone can be used, but disease transmission is a risk that must be considered [5–7]. Synthetic bone graft substitutes have been developed to obviate the risks and complications associated with auto- and allograft bone. Synthetic materials do not represent a panacea for complications related to bone grafting of cavitary defects. Some materials, such as calcium sulfate, are known to resorb more quickly than bony ingrowth can occur [8–12], whereas materials such as calcium hydroxyapatite can remain indefinitely [13, 14]. We have previously reported on the efficacy of bony incorporation of an ultraporous beta-tricalcium phosphate graft that appears related to lesion size, with some synthetic graft material persisting up to a year in larger lesions [15]. Another available synthetic bone graft substitute is a combination of calcium sulfate and beta-tricalcium phosphate (Pro-Dense, Wright Medical Technology, Inc., Memphis, TN). The rationale for the use of this product has been that the relatively rapid dissolution of the calcium sulfate within
1454
the composite would leave a more porous tricalcium phosphate, which would potentially allow for more optimal bone ingrowth. Studies have shown that graft resorption occurs in a typical centripetal pattern with osseous replacement of the graft proceeding beginning at the outer rim of the graft and continuing inward [16, 17]. Currently underway is an ongoing prospective clinical study comparing the results of this calcium sulfate/tricalcium phosphate graft and ultraporous betatricalcium phosphate in treating cavitary defects created in the treatment of low-grade neoplasms and other benign bone lesions (for the purposes of this study Bbenign osseous lesions^ is used for simplicity). Over the course of this study we have observed in some patients a deviation in the expected radiographic appearance of the calcium sulfate/tricalcium phosphate graft during the postoperative phase. Rather than the typical centripetal resolution of the graft, we have observed the appearance of an unexpected radiographic lucency (URL) in the area of the graft that seemed unrelated to recurrence of the original lesion. To date, this observation has not been reported. This work is intended to describe URLs in patients treated with the calcium sulfate/tricalcium phosphate bone graft substitute and analyze patient and primary lesion factors associated with their occurrence.
Materials and Methods This work is a retrospective comparative study of patients treated by the senior author with curettage and grafting using calcium sulfate/tricalcium phosphate during a 5-year period from December 2007 to December 2012 for benign osseous lesions. Patients with URL after treatment are compared to patients without these changes. This study was approved by the Institutional Review Board. One hundred eight consecutive patients received curettage and grafting with calcium sulfate/tricalcium phosphate during this time period and were eligible for inclusion in the study (Fig. 1). Of these, 21 were excluded for the following reasons: receiving graft for osteolysis related to prosthetic joints (11 patients), receiving a graft for a lesion other than a benign osseous lesion or cyst (1 patient), or inability to locate any radiographs (9 patients). Patients with radiographic evidence of an osseous lesion were evaluated by the senior author. Evaluation included patient history and clinical examination followed by review of relevant diagnostic imaging. Initial presumptive clinical diagnosis was made based on the history and appearance of the lesion on imaging. The clinical diagnosis was further evaluated by biopsy in all of the reported cases. Biopsy material in many cases was reviewed immediately at the time of surgery by frozen section by the senior author and pathologists and later confirmed by review of permanent sections by the pathology department. Most lesions underwent curettage and
Skeletal Radiol (2015) 44:1453–1459
grafting by the senior author. After open curettage of the lesion, the graft material was prepared according to the manufacturer’s instructions, delivered via syringe and a large bore bone marrow aspiration needle, and packed digitally to completely fill the defect. Excess graft material was removed from the surrounding soft tissues. In the case of simple bone cysts (SBCs), a percutaneous technique was used in two of the cases. An open technique was used for the other SBCs for the following reasons: when biopsy was required to confirm diagnosis, when prophylactic fracture fixation was deemed necessary, or when previous means of injection had failed. Prophylactic stabilization was accomplished in selected cases with either plate and screw constructs or intramedullary devices as deemed necessary by the senior author. Typically for upper extremity lesions, the patient was restricted from sports, upper extremity weights, and throwing (for the dominant extremity) for at least 6 weeks postoperatively and then allowed to progress as tolerated to full activities thereafter. For lower extremity lesions, we recommended crutches and partial weight bearing for 4 to 6 weeks postoperatively, and then the patient was allowed to progress as tolerated gradually to return to full activities over the ensuing several weeks. However, impact activities such as running, jumping, and contact sports were generally not recommended until 3 months postoperatively. Charts of the 87 patients meeting the inclusion criteria were reviewed for demographic and clinical data including lesion type, size, and location, volume of the graft used, type of stabilization if used, recurrence of disease, and reoperation. Radiographs were reviewed for URL and perilesional fracture. Unexpected radiographic lucencies were defined as deviation from the expected centripetal absorption of the calcium sulfate/tricalcium phosphate graft. When available, computed tomography (CT) scans were reviewed to confirm the deviation from expected behavior. Clinical relevance in either group was determined to be recurrence of disease, perilesional fracture, or reoperation. Patients were typically followed up with clinical examinations and postoperative surveillance radiographs at approximately 6 weeks, 3 months, 6 months, and 1 year routinely. Average follow-up for patients in the normal centripetal resolution group was 59.5 weeks (range of 7–171). Patients with evidence of URL were followed more closely once changes were identified. Patients from the group with URLs had their time of follow-up divided up into time to appearance of the lucency, with a mean 26.9 weeks (range 9–52 weeks), and time following identification of the lucency, with a mean 51 weeks (range 0–111 weeks). Overall mean length of follow-up post-surgery in the URL group was 77.46 weeks (range 19–163 weeks). Of those 74 patients who had undergone curettage and grafting with normal radiographic progression, 38 (51 %) were followed for at least 1 year, the latest time point at which the unexpected lucency occurred.
Skeletal Radiol (2015) 44:1453–1459
1455 Treated with calcium sulfate/tricalcium phosphate (n=108)
Excluded (n=21) Received gra for osteolysis related to prosthec joints (n=11) Inability to locate radiographs (n=9) Received gra for other than low grade lesion (n=1)
Included in study (n=87)
No nexpected radiographic lucency (n=74)
No complicaon (n=69)
Unexpected radiographic lucency (n=13)
Complicaon (n=5) Fracture (n=1) Recurrence of disease (n=4)
No complicaon (n=12)
Complicaon (n=1) reoperaon
Fig. 1 Flow chart showing the study design
For gender, anatomic location, and underlying pathological diagnosis, a Fisher exact test was used to test for statistical significance at p
