Gait Assessment of Patients with Spontaneous Osteonecrosis of the Knee. A Retrospective Case Controlled Study

Background: The purpose of this study was to characterize the gait patterns of patients with spontaneous osteonecrosis of the knee (SONK).

Methods: Twenty-eight patients (16 females and 12 males) diagnosed with SONK with a mean (sd) age of 67.3 (8.3) years participated in this study. 27 age-matched healthy controls, mean (ds) age 64.6 (10.7) years, were also evaluated. All patients underwent computerized spatiotemporal gait assessment during level walking at a self-selected speed. Primary outcome measures were gait velocity, cadence, step length and single limb support.

Results: Significant differences were found between patients with SONK and healthy controls in all spatiotemporal gait parameters. Patients with SONK had a significant lower walking speed (66.4 cm/s compared to 107.0 cm/s, a 38% decrease), lower cadence (59.9 steps/min compared to 110.3 steps/min, a 46% decrease), shorter step length (43.5 cm compared to 58.0 cm, a 25% decrease) and lower single limb support values (31.1% of gait cycle compared to 39.6% of gait cycle). Furthermore, patients with SONK presented significant asymmetry between the involved limb and uninvolved limb in SLS (31.1% of gait cycle compared to 38.8% of gait cycle for the involved and uninvolved limbs, respectively).

Conclusions: Patients with SONK present alterations in spatiotemporal gait parameters compared to normal control, suggesting that gait is significantly compromised by the disease. Furthermore, significant asymmetry was found in several gait parameters between the involved limb and uninvolved limb of patients with SONK.