1. Total Artificial Hip Joints Hassanain Ali M.Sc. in Medical Engineering

3. Hip Joint is one of the most joints in the Human Body. It connects the trunk to the lower limbs and it is capable of support the entire weight of the body and transfer this weight in stable condition during different modes of movement in many directions. Hip Joint is a multi axial ball and socket synovial joint. This property will allow free degrees of movement in all the three planes with marked degree of interlocking. 1) Sagittal Plane : Flexion / Extension. 2) Frontal Plane : Abduction / Adduction. 3) Transverse Plane : Medial / Lateral Rotation.

7. Hip Joint is one of the major weight bearing joint in the Human Body. Following list gives the maximum typical hip joint forces multiple of the body weight for different modes of movement : Standing 0.3 Standing on one Limb 2.6 Normal Walking 4.9 Down-stairs Climbing 5.1 Up-stairs Climbing 5.9 Jogging 7.6 Stumbling 8.7

13. (Above) Normal Hips with normal joint spaces. Osteoarthritis of the right hip (red arrow). Notice the joint space is thinned because of loss of cartilage.  The bony margins are white or sclerotic form bone reaction.  The left hip (large white hip)  has already been replaced with a hip prosthesis.

16. The basic idea of total hip replacement based on resurfacing the diseased hip joint through replacing it with another one made of synthetic material. The major design issues of artificial hip joint are : 1) The geometric and material design of the articulating surfaces. 2) Interface design between the artificial joint and the surrounding bone. Typical total artificial hip joints are comprised of the same basic parts as the natural hip joint involved with, as well as to provide more natural shape and function.

17. It consists of a CUP, a HEAD and a STEM that made of several materials selected due to their mechanical properties and biocompatibilty.

19. Design Considerations # Head Size a configuration and size that fits the anatomical shape of the femur head. # Neck Length a length that allows adequate fixation of the acrylic cement. # Shaft Length and Shape dimensions that do not exceed narrowest segments of the shaft. # Stem Tapering Angle a degree of tapering that facilitates the long-term fixation.

45. The hip joint replacement for human body is a complex and dynamic field, thus engineers and orthopedics co-operate to make the patient's life a normal and painless as possible.

46. Total Artificial Hip Joints Hassanain Ali M.Sc. in Medical Engineering