[Acetabular revision with impacted irradiated frozen allografts].

Objective: To analyze the clinical and radiographical result of acetabular revisions with wire mesh, impacted irradiated frozen allografts and cemented cups.

Methods: From February 2006 to January 2009, a total of 20 patients with 21 acetabular revisions were performed with wire mesh, impacted irradiated frozen allografts and cemented cups. Eighteen cases (19 hips) were followed up. There were 5 hips in 4 males and 14 hips in 14 females. The average age of patients was 64.4 years (43 to 81 years). Acetabular bone defects were classified according to Paprosky classification. There were Paprosky II B in 4 hips, Paprosky II C in 8 hips, Paprosky IIIA in 5 hips and Paprosky IIIB in 2 hips. Wire mesh was used to converted segmental defects into cavity defects. Irradiated frozen allografts were impacted and cemented cup was inserted to complete the revision. Patients were followed up regularly with clinical and radiographical assessment. Harris score, migration and loosening of prosthesis grafts integration and complications were observed.

Results: The average follow-up time was 22.4 months (12 - 48 months). Harris score improved from 42.5 points (31 - 56 points) pre-operation to 88.6 points (82 - 96 points) at the final follow up. Pain score was 14.4 point (10 - 20 point) before revision and 42.3 points (40 - 44 point) at the final follow up.

Complications: there was 1 infection and healing after debridement. One patient had weakness of quadriceps and returned to normal after 1 year. Greater trochanter fracture occurred in 1 patient. Cup migration and loosening were observed in 1 Paprosky IIIB patients. There was no cup migration more than 1 mm or change of abduction angle in the remaining 18 hips. Grafts incorporation defined as the presence of trabecular bone crossing the graft-host bond could also be seen in these 18 hips.

Conclusions: Impacted bone grafting technique combined with wire mesh and cemented cup is an effective method for biological acetabular revision. Irradiated frozen allografts implanted with impaction bone grafting technique can integrate with the surrounding host bone.