Computer-assisted surgery for correction of skeletal deformities

Abstract

The term «orthopaedics» was originated from the Greek words ortho and «paideia» and has been traditionally used to describe the branch of medicine concerned with the correction or prevention of skeletal deformities. The burden of bone and joint deformities in developing countries is huge due to the prevalence of congenital, posttraumatic, metabolic (rickets), neurological (poliomyelitis) and other underlying conditions. Verma [1] reported that in India, a very large number of infants with genetic disorders are born every year, almost half a million with malformations and 21,000 with Down syndrome. In developed countries, skeletal deformities may have a different distribution and etiology but the burden on health care is still significant. Deformities secondary to Paget's disease and inflammatory arthropathy are relatively more common in developed countries. There is a common association between skeletal deformities and arthritis and in some cases, surgeons may debate which is the cause or the result. In arthritic joints, the location of deformities could be around the joint or in the shafts of long bones. There are different trends for treating arthritis that are associated with deformities particularly, those around the joint. In developing countries, there is a trend to treat osteoarthritis and correct deformities by osteotomies. In developed countries, the trend is to treat arthritis by joint replacement and correct the deformities according to their location. In addition to the location of deformities, there are other factors such as age that can influence the choice of treatment options. Whatever the type of treatment, accuracy and reproducibility are important factors for successful outcome of procedures such as knee replacement [2, 3] or osteotomy [4, 5]. Accuracy and precision are required for pre-operative planning and surgical implementation. Computer-assisted surgery (CAS) is an enabling technology that has the potential to improve accuracy and reproducibility and overcome drawbacks of conventional techniques. Literature is now abundant with reports comparing navigation against conventional techniques, particularly for total knee replacement (TKR). Several randomized trials [6-12] showed superior accuracy of navigation techniques. Other comparative trials [13-18] showed more precise placement of implants with navigation techniques. The elimination of IM rods reduces the risk of blood loss and fat embolism [7, 19]. CAS systems can act as training tools and can measure operative performance and surgical outcome, thus supporting research and documentation. Deformity correction is also well suited for CAS, as corrective procedures require accurate planning and precise performance. CAS systems can also provide real time intra-operative guidance similar to fluoroscopic images and subsequently reduce the screening time and radiation exposure, which is on the rise [20]. There are reports of different CAS techniques used for deformity correction such as robotics, navigation and planning software. The authors present their experience in using different CAS techniques for deformity correction, namely navigation, patient-specific templates and planning software (Taylor Spatial Frame). This chapter also reflects the different CAS approaches applied in both developed and developing countries. © 2007 Springer Medizin Verlag Heidelberg.