Assessment of kinematic and kinetic patterns following limb salvage procedures for bone sarcoma

Bone sarcomas are the fourth most common cancer in individuals under 25 years. Limb salvage procedures have become increasingly popular for the treatment of osteosarcomas as they have functional and psychological benefits over traditional amputative procedures. The purpose of this paper was to evaluate kinematic and kinetic characteristics of patient's post-limb salvage and examine key predictive factors of gait dysfunction. A retrospective outcome study was undertaken on 20 limb salvage patients (10 females, 10 males) recruited from the Queensland Bone Tumour Registry. Kinematic and kinetic data were collected using a 3D motional analysis system and three force platforms. Loading response knee flexion in the affected lower limb was reduced compared to the unaffected lower limb (P<0.001) and the control group (P<0.001), although, closer examination of results showed two contrasting patterns of knee flexion during loading. Multiple regression analysis showed that muscular integrity (i.e. strength, ROM and residual mass) was the most predictive factor of function following limb salvage surgery. ANOVA showed that patients treated with the Stanmore SIMLES prostheses exhibited superior torque and power production at the ankle during late stance compared to those treated with the Stryker HMRS. In summary, the results showed that limb salvage patients adopted a gait pattern that reduced the moment demand at the knee and hip, suggesting a compensation for pain, reduced stability and/or muscle weakness.