Osteotomy Action

We still do not understand the reason for the often-dramatic beneficial effects of osteotomy. Evidence suggests that venous tension is raised in the long bones adjacent to arthritic joints and that the venous network is altered (Benjamin et. al 1993 p.69 Fig. 7.8). Osteotomy reduces intraosseous pressure (Brookes and Helal 1968; Arnoldi et al. 1971). Operations have been devised to reduce intraosseous pressure without osteotomy, including the forage operation for the hip (K.I. Nissen, personal communication 1956) and drilling with the insertion of tubes at the knee as described by Arden and Hirschowitz (1976). Long-term results of these limited procedures are disappointing.

The effect of osteotomy is due not merely to the alteration of weight-bearing forces; there are indications of a biological rather than a purely mechanical effect. (Nissen 1971) Immediately on awakening from anaesthesia after osteotomy, the patient frequently exclaims, 'the pain has gone'. Division of the autonomic afferent nerves present in the arteries may play a part. Following successful osteotomy, there is both clinical and radiological improvement continuing for 18 months this improvement occurs in the relatively non weight-bearing joints of the upper limb as well as those of the lower. A hot, swollen, rheumatoid metacarpophalangeal joint rapidly subsides to normal size following osteotomies proximal and distal to the joint; within 10 days skin normal wrinkles not seen for years reappear. A similar regression of synovium follows double osteotomy at the rheumatoid knee.

Fibrocartilage regeneration occurs after osteotomy as it does after procedures such, as arthroscopic abrasion chondroplasty (Dandy 1986; Rand and Ritts 1989), Pridie's procedure, which involves the removal of small circles of bare bone with a trephine (Pridie 1959), and the Ilizarov technique. There is hope that in the future we may be able to encourage regenerative potential, perhaps of fibrocartilage. Pluripotential stem cells occur at the osteotomy sites and there is evidence that they are capable of homing to damaged tissue. (Science 294: 1933, 2001 Wright et al).