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Bone healing of severe acetabular defects after revision arthroplasty.

Ullmark G, Sörensen J, Nilsson O - Acta Orthop (2009)

Bottom Line: The contralateral pelvic bone above the acetabulum was used as reference.Preoperatively, the uptake was raised by 64% compared to the reference. 1 week after surgery it was increased by 77% in segmental regions, while the uptake was at the reference level in cavitary regions.After 4 months the uptake was increased by 91% in cavitary regions and by 117% in segmental regions. 1 year after surgery, the increase in uptake was 20% in both regions.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopedics, Gavle Hospital Center for Research and Development Uppsala University/Gavleborg County Council, Uppsala, Sweden.

ABSTRACT

Background and purpose: Healing of acetabular bone grafts may be difficult to assess in conventional radiographs. We used PET to analyze healing of morselized bone allografts, impacted in large osteolytic acetabular defects at revision arthroplasty.

Patients and methods: 7 cases had a cup revision because of loosening, with repair of a segmental defect using a perforated, wide and thin plate. The osteolytic acetabulum was impacted with morselized bone allograft before cementing a polyethylene cup. [(18)F]-fluoride PET scans were used to monitor bone healing inside the graft bed 1 week, 4 weeks, and 12 months after surgery. The contralateral pelvic bone above the acetabulum was used as reference. A second group of 4 cases was analyzed for bone-forming activity in the state of mechanical loosening of an acetabular component of a THA.

Results: Preoperatively, the uptake was raised by 64% compared to the reference. 1 week after surgery it was increased by 77% in segmental regions, while the uptake was at the reference level in cavitary regions. After 4 months the uptake was increased by 91% in cavitary regions and by 117% in segmental regions. 1 year after surgery, the increase in uptake was 20% in both regions. All implants were stable on radiographs.

Interpretation: We found PET to be a sensitive and useful method for evaluation of the spatial and temporal development of bone formation.

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Related in: MedlinePlus

Combined segmental and cavitary osteolytic bone defects of the acetabulum.
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Figure 0001: Combined segmental and cavitary osteolytic bone defects of the acetabulum.

Mentions: All patients received systemic antibiotic prophylactics during surgery. All were operated using a posterior surgical approach. The loose prosthesis and cement was removed together with any debris and fibrous membrane, to lay bare the cavitary widened acetabulum. All patients also had a segmental defect of the acetabular rim (Figure 1). The rim defects were restored from the outside by a flexible 0.8-mm-thick metal plate fully perforated with 4-mm holes. This Titanium Acetabular Rim Mesh (Waldemar Link GmbH, Hamburg, Germany) was anchored with several small titanium screws (Figure 2). The medial wall defect was restored by a semi-flexible 0.8-mm thick perforated cage: a Titanium Acetabular Graft Cup from the same company (Figure 3). The cage is also perforated with 4-mm holes to allow for screw fixation, and for bone ingrown through the holes. Graft impaction was performed using acetabular impactors from the Lubinus SPII Impaction Instrument Set (Waldemar Link). Those impactors are equipped with a microstructure to enhance hard impaction (Figure 4). There are also several small holes for evacuation of liquid to produce a more stable graft bed (Fosse et al. 2006). This structure of the impactor may enhance the containment of a blood clot within the graft layer. We aimed for the true center of rotation of the hip. An acetabular polyethylene cup of 4-mm smaller diameter than the very hard impacted neo-acetabular diameter was cemented using Palacos cum gentamicin, and thus space for a 2-mm cement mantle was created.


Bone healing of severe acetabular defects after revision arthroplasty.

Ullmark G, Sörensen J, Nilsson O - Acta Orthop (2009)

Combined segmental and cavitary osteolytic bone defects of the acetabulum.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2823168&req=5

Figure 0001: Combined segmental and cavitary osteolytic bone defects of the acetabulum.
Mentions: All patients received systemic antibiotic prophylactics during surgery. All were operated using a posterior surgical approach. The loose prosthesis and cement was removed together with any debris and fibrous membrane, to lay bare the cavitary widened acetabulum. All patients also had a segmental defect of the acetabular rim (Figure 1). The rim defects were restored from the outside by a flexible 0.8-mm-thick metal plate fully perforated with 4-mm holes. This Titanium Acetabular Rim Mesh (Waldemar Link GmbH, Hamburg, Germany) was anchored with several small titanium screws (Figure 2). The medial wall defect was restored by a semi-flexible 0.8-mm thick perforated cage: a Titanium Acetabular Graft Cup from the same company (Figure 3). The cage is also perforated with 4-mm holes to allow for screw fixation, and for bone ingrown through the holes. Graft impaction was performed using acetabular impactors from the Lubinus SPII Impaction Instrument Set (Waldemar Link). Those impactors are equipped with a microstructure to enhance hard impaction (Figure 4). There are also several small holes for evacuation of liquid to produce a more stable graft bed (Fosse et al. 2006). This structure of the impactor may enhance the containment of a blood clot within the graft layer. We aimed for the true center of rotation of the hip. An acetabular polyethylene cup of 4-mm smaller diameter than the very hard impacted neo-acetabular diameter was cemented using Palacos cum gentamicin, and thus space for a 2-mm cement mantle was created.

Bottom Line: The contralateral pelvic bone above the acetabulum was used as reference.Preoperatively, the uptake was raised by 64% compared to the reference. 1 week after surgery it was increased by 77% in segmental regions, while the uptake was at the reference level in cavitary regions.After 4 months the uptake was increased by 91% in cavitary regions and by 117% in segmental regions. 1 year after surgery, the increase in uptake was 20% in both regions.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopedics, Gavle Hospital Center for Research and Development Uppsala University/Gavleborg County Council, Uppsala, Sweden.

ABSTRACT

Background and purpose: Healing of acetabular bone grafts may be difficult to assess in conventional radiographs. We used PET to analyze healing of morselized bone allografts, impacted in large osteolytic acetabular defects at revision arthroplasty.

Patients and methods: 7 cases had a cup revision because of loosening, with repair of a segmental defect using a perforated, wide and thin plate. The osteolytic acetabulum was impacted with morselized bone allograft before cementing a polyethylene cup. [(18)F]-fluoride PET scans were used to monitor bone healing inside the graft bed 1 week, 4 weeks, and 12 months after surgery. The contralateral pelvic bone above the acetabulum was used as reference. A second group of 4 cases was analyzed for bone-forming activity in the state of mechanical loosening of an acetabular component of a THA.

Results: Preoperatively, the uptake was raised by 64% compared to the reference. 1 week after surgery it was increased by 77% in segmental regions, while the uptake was at the reference level in cavitary regions. After 4 months the uptake was increased by 91% in cavitary regions and by 117% in segmental regions. 1 year after surgery, the increase in uptake was 20% in both regions. All implants were stable on radiographs.

Interpretation: We found PET to be a sensitive and useful method for evaluation of the spatial and temporal development of bone formation.

Show MeSH
Related in: MedlinePlus