The origin of osteoprogenitor cells responsible for heterotopic ossification following hip surgery: An animal model in the rabbit

Abstract

Purpose. To investigate the source of osteoprogenitor cells responsible for heterotopic ossification (HO) following total hip arthroplasty in an animal model.Methods. New Zealand White (NZW) rabbits ( n = 20) received a radiation treatment 24 h preoperatively to the hip joint of one hindquarter and to the femoral shaft of the contralateral side. Subjects underwent bilateral hip surgery 24 h after treatment. Subjects were euthanized and radiographed 4 months postoperatively. Heterotopic ossification was graded according to a modified Brooker scale. Mean grade, intra-observer reliability, and statistical significance 0, < 0.05) were evaluated to compare the severity of heterotopic ossification between hindquarters treated with hip irradiation versus those treated with femoral shaft irradiation.Results. The Fleiss Weighted Kappa Statistic indicated "almost perfect" (0.872) intra-rater reliability of radiographic heterotopic ossification grading. The average heterotopic ossification grade for the group receiving radiation to the hip was significantly greuter than that for the group receiving radiation to the femoral shaft (2.575 versus 2.0, p < 0.02).C~inclusion. Although both have some beneficial effect, our results demonstrate that irradiation of the femoral canal is significantly more effective than irradiation of the hip joint and abductor musculature for heterotopic ossification prophylaxis. This suggests that osteoprogenitor cells responsible for heterotopic ossification originate from both the hip abductors and the femoral canal, but the data provide indirect evidence that the femoral canal may be a more dominant source of these cells in the rabbit model.

The regeneration and augmentation of bone with injectable osteogenic cell sheet in a rat critical fracture healing model

“…Furthermore, the circulation and vasculature [26,27], as well as the surrounding local tissues [28], offer an additional source of osteoprogenitor cells that has been implicated in bone formation and healing. Because clinical patients often exhibit delayed healing with compromised host bone tissue at fracture sites with reduced numbers of osteoprogenitor cells in their bone marrow [29], we used a rat critical bone healing model involving bone marrow ablation and the removal of femora periosteum, as previously reported by Kaspers et al [30].…”

Does a Plastic Drape Reduce Incidence of Heterotopic Ossification After Hip Resurfacing?

“…This correlates to the location of HO we found. Rumi et al [46] suggest osteoprogenitor cells responsible for HO originate from both the hip abductors and the femoral canal and the efficacy of local radiation indicates the osteogenic precursor cells are derived from local tissue rather than blood-borne cell lines. The femoral canal is not violated in hip resurfacings, but reaming and shaping the femoral head leave a substantial amount of bone debris that may supply the osteoprogenitor cells needed to stimulate bone growth within the soft tissues.…”

Early Detection of Heterotopic Ossification for Effective Prevention and Treatment

“…The purpose of this pilot study was to familiarize the hip topographic anatomy of rats and test the animal tolerance to the proposed surgery. A commonly used HO model is to induce ossification by ischemic muscle injury [28] . Under anesthesia, both rat hips were prepared for surgery.…”