Muscle strength characteristics following megaprosthetic knee reconstruction for bone sarcoma
Merethe Lia Johansen1, Ola Eriksrud2, Joachim Thorkildsen3
1Division of Cancer Medicine, Department of Clinical Service, Section for Cancer Rehabilitation, Oslo University Hospital, Oslo, Norway.
Surgical Oncology
|April 16, 2023
Summary
Patients with knee bone sarcoma reconstruction have significantly reduced muscle strength, especially in knee extension. Despite good functional scores, they exhibit impaired force development compared to controls.
Area of Science:
- Orthopedic Surgery
- Musculoskeletal Oncology
- Rehabilitation Medicine
Background:
- Bone sarcoma resection and megaprosthetic reconstruction of the knee present significant challenges.
- Assessing long-term functional outcomes, particularly muscle strength, is crucial for patient recovery and quality of life.
Purpose of the Study:
- To quantitatively assess muscle strength characteristics in patients who underwent knee resection and megaprosthetic reconstruction for bone sarcoma.
- To compare these strength metrics against age- and sex-matched healthy controls.
Main Methods:
- A cross-sectional, case-control study design was employed.
- Isokinetic dynamometry was used to measure knee extension and flexion torque at 60, 120, and 180°/s.
- Rate of force development (RDFmax) in knee extension was assessed, alongside the Toronto Extremity Salvage Score (TESS) in patients.
Main Results:
- Patients demonstrated significantly lower maximal knee extension torque (19-23% of controls) and knee flexion torque (53-60% of controls).
- The rate of force development was markedly impaired in the operated leg compared to controls.
- Despite functional deficits, patients achieved a mean TESS score of 84.0.
Conclusions:
- Patients with knee megaprosthetic reconstruction exhibit substantial deficits in knee extensor strength, achieving only about 20% of control values.
- Impaired force generation capacity persists long-term, even with good functional scores, highlighting the need for targeted rehabilitation.
