Physical activity levels after limb salvage surgery are not related to clinical scores-objective activity assessment in 22 patients after malignant bone tumor treatment with modular prostheses.

BACKGROUND: The aim of the present study was to objectively assess the physical activity levels of patients after tumor prosthesis implantation with two objective measurement devices. METHODS: The DynaPort ADL monitor permitted up to 24 hr monitoring of lower-extremity physical activities in daily life with respect to posture and locomotion. The step activity monitor (SAM) was worn for a whole week to collect the daily number of gait cycles. The devices were worn during the waking hours by 22 patients with knee prostheses after wide tumor resection. RESULTS: In the MSTS and TESS scores the patients achieved over 80% of the maximum score indicating a good clinical outcome. The most prominent activity was sitting which accounted for 54 +/- 18% of the recorded time, followed by standing (27 +/- 16%), locomotion (10 +/- 6%), and lying (8 +/- 6%). During locomotion, the average walking activity accumulated to 4,786 +/- 1,770 step cycles per day (range 2,045-8,135) corresponding to a yearly 1.75 million steps. There was no significant correlation between clinical scores and step count measures. CONCLUSIONS: Even though this activity level was lower than for a group of healthy adults it was comparable to the activity level for other patients, for example, with hip arthroplasty as reported in the literature.