Effects of low-dose radiotherapy on fresh osteochondral allografts: an experimental studyin rabbits

Abstract

Objective: The aim of the present study was to investigate effects of low-dose fractionated radiotherapy on distal femoral fresh massive osteochondral allografts (OCAs) in the prevention of cartilage degeneration due to immune response.

Methods: Twenty-four New Zealand White rabbits were divided into 3 groups of 8 rabbits each. All rabbits underwent distal femoral medial condyle fresh massive OCA transplantation. The transplants were obtained from California rabbits. Group 1 underwent transplantation without any preliminary process. Group 2 underwent fractionated local radiotherapy of 100 cGy for 5 days, beginning on the day of transplantation. Group 3 included rabbits that received graft transplants after undergoing in vitro radiation with a single dose of 1500-cGy radiation. The hosts were sacrificed 12 weeks after transplant. Anteroposterior and lateral radiographs were taken. Synovial tissue, cartilaginous tissue, and subchondral bone were histopathologically assessed.

Results: Nonunion was present in 3 rabbits in Group 2 and 1 rabbit in Group 3. Cartilage degeneration was found to be higher in Group 3. Synovial hypertrophy and pannus formation were more obvious in non-radiated rabbits. Hypocellularity and necrosis of the subchondral bone were rare in Group 2. Increased cartilage tissue impairment was observed in Group 3, compared to Group 1.

Conclusion: In osteochondral massive allograft transplantation, immune reaction of the host may be precluded by radiotherapy, and side effects can be prevented with a low-dose fractionated regimen. Total dose of fractionated radiotherapy for immune suppression should be adjusted to prevent damage to cartilage tissue and to avoid articular degeneration in the long term.

 

DOI: 10.3944/AOTT.2016.16.0022
This abstract belongs to the un-edited version of the article and is only for informative purposes. Published version may differ from the current version.

Keywords

• Osteochondral allograft; radiotherapy