Joint mobility is dependent on comfort, thus pain is associated with mobility. This study examined the relationship between pain perception and joint mobility in arthritis patients before and after total knee arthroplasty. Pain perception was indicated by pain intensity, pain distress and pain expectation; joint mobility was represented by the degree of knee joint flexion. Visual analogue scales were used for pain intensity, pain distress and pain expectation; knee joint flexion as measured using a goniometer. Data were collected on 24 subjects preoperatively (T1), immediately postoperatively (T2) and forty-eight to seventy-two hours postoperatively (T3). Twenty-four subjects participated in the study. Significant paired t-test resulted for joint flexion at T1 and T3 and pain expectation at T2 and T3. Pearson product-moment correlation coefficients were significant for pain intensity and pain distress at all three times, pain intensity and joint flexion at T1 and pain intensity at T1 and at T2.

Passive knee motion is guided by the interaction of the articular surfaces and the restraining role of the soft-tissue structures. It is defined by characteristic kinematics within an envelope of motion. The main goal of this thesis was to simulate this characteristic motion by developing a subject-specific anatomically based finite element model. CT and MR image stacks were used to develop the geometry model and experimental (mechanical) test data was used as model input. Passive knee flexion was simulated and translational and rotational motion described using the Joint Coordinate System (JCS). The model was validated using clinical flexion and AP drawer tests. An ACL reconstruction model was also developed. Highest AP laxity was found at 30?? of flexion when the graft was positioned in the original native ACL insertion point. ACL tunnel positions were simulated according to surgical techniques. For this case, the highest AP laxity was displayed at 0?? of flexion. Four different graft materials were examined, with the quadriceps tendon graft exhibiting highest laxity, followed by the patellar tendon, braided hamstring and finally unbraided hamstring graft. The effect of malpositioning the graft's femoral attachment point from its central location was also investigated. The proximal femoral attachment point most closely mimicked the central attachment point in terms of AP laxity in the native ACL insertion group. In the ACL tunnel group, the posterior femoral attachment point most closely mimicked the intact knee. In this thesis it was found that changing the femoral insertion point of the graft can highly influence the AP laxity behaviour. Also using the surgical technique to create ACL tunnels may not necessarily produce the same kinematic behaviour as the intact knee. Lastly, this thesis has shown the importance of explicitly defining the local reference coordinate system when describing knee kinematics. Changing the coordinate system markedly alters the calculated kinematics. Ideally, a standardisation of local coordinate systems, similar to the JCS, would be proposed within the biomechanics community.

Passive knee motion is guided by the interaction of the articular surfaces and the restraining role of the soft-tissue structures. It is defined by characteristic kinematics within an envelope of motion. The main goal of this thesis was to simulate this characteristic motion by developing a subject-specific anatomically based finite element model. CT and MR image stacks were used to develop the geometry model and experimental (mechanical) test data was used as model input. Passive knee flexion was simulated and translational and rotational motion described using the Joint Coordinate System (JCS). The model was validated using clinical flexion and AP drawer tests. An ACL reconstruction model was also developed. Highest AP laxity was found at 30?? of flexion when the graft was positioned in the original native ACL insertion point. ACL tunnel positions were simulated according to surgical techniques. For this case, the highest AP laxity was displayed at 0?? of flexion. Four different graft materials were examined, with the quadriceps tendon graft exhibiting highest laxity, followed by the patellar tendon, braided hamstring and finally unbraided hamstring graft. The effect of malpositioning the graft's femoral attachment point from its central location was also investigated. The proximal femoral attachment point most closely mimicked the central attachment point in terms of AP laxity in the native ACL insertion group. In the ACL tunnel group, the posterior femoral attachment point most closely mimicked the intact knee. In this thesis it was found that changing the femoral insertion point of the graft can highly influence the AP laxity behaviour. Also using the surgical technique to create ACL tunnels may not necessarily produce the same kinematic behaviour as the intact knee. Lastly, this thesis has shown the importance of explicitly defining the local reference coordinate system when describing knee kinematics. Changing the coordinate system markedly alters the calculated kinematics. Ideally, a standardisation of local coordinate systems, similar to the JCS, would be proposed within the biomechanics community.

published_or_final_version / abstract / Nursing Studies / Master / Master of Philosophy