The effects of extraperiosteal and subperiosteal dissection. II. On fracture healing.

The effects of subperiosteal and extraperiosteal dissection on the healing of tibial osteotomies were studied in fourteen rabbits killed three weeks after the osteotomy. Of the tibiae exposed subperiosteally, 71 per cent healed; of those exposed extraperiosteally, only 7 per cent had solid union. The first group had a significantly lower level of hydroxyproline in the callus and higher values for breaking load, breaking strength, and absorption of energy to failure. In ten animals that also had muscle transection at the osteotomy site, the rate and type of healing was similar whether no dissection, subperiosteal dissection, or extraperiosteal dissection had been done, but the callus showed lower calcium levels and higher hydroxyproline levels than in either of the groups with muscle trauma. This implies retardation of healing caused by muscle injury. Our data suggest that in the absence of muscle damage, subperiosteal dissection results in earlier healing than does extraperiosteal dissection. Muscle transection markedly retards healing; then, after transection, neither type of dissection appears to retard healing more than the other.