Preliminary Application Of Gait Analysis Plantar Pressure System In End-Stage Osteonecrosis Of Femoral Head

Objective: Osteonecrosis of the femoral head(ONFH)is a progressive disease with a complex etiology and unknown pathogenesis.Patients often suffer from hip pain and walking dysfunction due to interruption of blood supply to the femoral head,subchondral bone necrosis,and collapse of the femoral head.Gait analysis is an examination tool that uses physical means to study walking patterns,which can objectively assess the functional behavior of the foot and thus reveal the key aspects and influencing factors of gait abnormalities,and is considered to be an effective complement to clinical and imaging assessments.The purpose of this study was to use the gait analysis plantar pressure system to assess the differences in spatiotemporal parameters,static and dynamic plantar pressure parameters,and symmetry indices between patients with ONFH and healthy individuals,in the hope of providing sensitive quantitative parameters for the diagnosis and subsequent treatment and rehabilitation of ONFH.Methods: The study population consisted of 31 patients with ONFH and 31 healthy subjects.Gait parameters were obtained from the plantar pressure analysis system for both the ONFH and healthy groups,including spatiotemporal parameters,static and dynamic plantar pressure distribution in each plantar region,percentage of regional impulse and percentage of the restricted contact area,and the symmetry index was calculated according to the formula.The differences between ONFH patients and healthy subjects in the above gait parameters were observed in comparison.Results: Compared with healthy controls,patients with ONFH had slower walking speed,shorter step length and stride length,and increased stride time,stance time,and percentage of stance.patients with ONFH had lower plantar static pressure on the affected side and higher contralateral plantar static pressure during stance than controls.During walking,the peak pressures in all regions on the affected side and the peak pressure in the toe 1 and metatarsal 3 regions on the healthy side were lower in ONFH patients than in controls.The percentage of contact area and regional impulse in the heel of both limbs were higher in ONFH patients than in the control group.The symmetry indexes of stride time,stance time,step length,maximum force,impulse and contacted area were significantly increased in ONFH patients compared to controls,with decreased symmetry.Conclusion:Osteonecrosis of the femoral head leads to characteristic changes in plantar pressure distribution.These changes may be interpreted as an attempt by patients with ONFH to reduce the load on the affected limb.Plantar pressure analysis may assist in the diagnosis of ONFH and can provide an objective quantitative indicator for the assessment of subsequent treatment outcomes.