Muscle Strength and Power Improve Despite Small Increase in Quadriceps Cross-Sectional Area in Massive Knee Joint Destruction: A Two-Year Follow-Up Case Report

Joint damage may result from different conditions, including osteoarthritis, rheumatoid arthritis, infection, and haemophilic arthropathy. Long-term effects of resistance training in individuals with massive joint destruction remain poorly documented. We report a case of a patient with haemophilia and massive joint destruction who completed a two-year home-based knee-extension programme. Training was performed twice weekly and included biofeedback-guided isometric knee extension at 80% of maximal voluntary isometric strength, followed by a closed-chain exercise using elastic resistance. Structural knee damage and quadriceps cross-sectional area (CSA) were assessed using computed tomography (CT). Pain, knee-extension strength, quadriceps CSA, and 30-s sit-to-stand performance were assessed at baseline and at two-year follow-up. Pain during active knee extension decreased from 6/10 to 2/10, and pain during daily activities decreased from 6/10 to 4/10. Knee-extension strength increased from 7 kgf to 20 kgf, representing a 186% increase. The 30-s sit-to-stand performance improved from 14 to 22 repetitions and estimated relative sit-to-stand muscle power increased from 3.4 to 5.3 W/kg, representing a 57% increase. Notably, quadriceps CSA increased by only 6% (from 1954.9 to 2078.6 mm2). No bleeding episodes or other adverse events were reported. After two years of strength training, marked gains in muscle strength and power were observed despite a small increase in quadriceps cross-sectional area. This case report highlights the need for future long-term follow-up studies of strength training in individuals with advanced joint damage.