Designing suitable sizes of hip implants for Indian patients.
A large number of orthopaedically handicapped patients in India require treatment with suitable low-cost implants of varied sizes and shapes, which has become a crucial problem today. Out of these patients, the case of degenerative hip joints is around one-half million every year, the majority of which are total hip replacements. For most of these cases, the surgery is done with imported implants, which may not be in keeping with the osteological dimensions of Indian patients. To explore this area, a study was done at CMERI on computed tomographic (CT) scan data of the proximal region of the femur bone of patients from different regions of India. Since the problem is prominent with the elderly populations who are above 50 years of age, the CT scan data was collected for patients with age of 50-78 years. In this study, 23 selected osteological dimensions of each femur were measured in a CAD environment from CT scan data of around 100 elderly Indian patients. The measured parameters were statistically analyzed to find out the variations and stepping of dimensions. Depending on these data, the stem of hip implant was designed with different sizes, suitable for Indian patients. The devices were then analyzed in finite element analysis packages individually, as well as by putting the device inside the femur bone, as an actual case. After this analysis, some modifications were required and it was found that after implantation the stress induced in the implant and bone would be well within permissible limits.
Maji
Palash Kumar
PK
Central Mechanical Engineering Research Institute, Durgapur. palash_maji@hotmail.com
Banerjee
Partha Sarathi
PS
Sinha
Anupam
A
D019644:Arthroplasty, Replacement, Hip / Q000592:standards*; D006801:Humans; D007194:India / Q000453:epidemiology; D015207:Osteoarthritis, Hip / Q000453:epidemiology* / Q000601:surgery; D011474:Prosthesis Design