Isokinetic knee strength deficit in patients with moderate haemophilia

Abstract

Introduction Knee joint bleedings are responsible for quadriceps atrophy and strength deficit in patients with severe haemophilia. Little is known about patients with moderate haemophilia (PWMH). Aim To evaluate isokinetic quadriceps and hamstrings strength in PWMH and to assess correlation with radiological and clinical parameter. Methods 18 PWMH aged 37.1 ± 11.4 and 18 healthy age‐, weight‐ and height‐matched controls performed a knee isokinetic test at 180°/s to assess quadriceps and hamstrings strength. In the PWMH group, knee Pettersson's score was pursued and Haemophilia Joint Health Score 2.1 (HJHS) was performed to determine unaffected knees (knee HJHS = 0) and affected ones (knee HJHS >0). Results Affected knees had a decrease of quadriceps strength compared to controls, 1.26 ± 0.47 vs 1.64 ± 0.27 Nm/kg and a decrease of hamstring strength, 0.60 ± 0.29 vs 1.03 ± 0.21 Nm/kg, (P < 0.001). Unaffected knees also had a decrease of quadriceps strength compared to controls, 1.36 ± 0.31 vs 1.64 ± 0.27 Nm/kg and a decrease of hamstring strength, 0.69 ± 0.18 vs 1.03 ± 0.21 Nm/kg, (P < 0.001). The conventional hamstring‐to‐quadriceps ratio was significantly decreased in affected knees compared to controls, 0.46 ± 0.15 vs 0.64 ± 0.13 (P < 0.001) but also in unaffected knees, 0.53 ± 0.16 vs 0.64 ± 0.13 (P = 0.02).No correlation was found between strength and HJHS or Pettersson's score. Conclusion PWMH have a significant knee strength deficit, both on the quadriceps and the hamstrings, which is responsible for an important muscle imbalance.