Clinical Trial: Dynamic Evaluation of Ankle Joint and Muscle Mechanics in Children With Spastic Equinus Deformity Due to Cerebral Palsy

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: In Vivo Dynamic Evaluation of Ankle Joint and Muscle Mechanics in Children With Spastic Equinus Deformity Due to Cerebral Palsy: Implications for Recurrent Equinus.

Brief Summary: This research will lead to the first evaluation of intrinsic and dynamic joint and muscle mechanics of equinus in cerebral palsy. It would provide a direct cause and effect relationship between equinus and bone deformity. Mechanical insights to the pathophysiology of the targeted muscles will lead to better understanding and, thus, to a better medical and surgical management of equinus deformity. Secondary aim will provide an important insight whether key gait parameters can be exclusively relied upon for surgical treatment planning and evaluation. In a medium-term perspective, depending upon the results of this study, dynamic MRI of the ankle joint may serve as a guiding tool for fixed equinus surgery in case of cerebral palsy.

Detailed Summary: Equinus is the most common deformity in children with cerebral palsy. Spastic equinus is typically defined as the inability to dorsa-flex the foot above plantigrade, with the hindfoot in neutral position and the knee in extended position. Approximately 90% of the deformities in cerebral palsy occur in the ankle and foot region alone with the incidence of equinus being around 75%. Spastic equinus exhibits poor muscle control and muscle weakness around ankle and foot, resulting in bone deformities and gait abnormalities. Non-operative conservative management of equinus is typically undertaken up until 8 years in order to prevent recurrent equinus or overcorrection by avoiding high-growth phase of child's development for surgical intervention. Despite these precautions, long term follow-up studies report up to 48% of recurrence rate post-surgery. Recurrence surgery not only increases the economic burden on the society but also has a debilitating impact on children and their families. Previous research is focused on extrinsic risk factors such as CP type, demographic parameters, and clinical gait parameters for surgical recurrence and none assessed the dynamic impact of intrinsic bone deformity on ankle joint and muscle mechanics. A primary reason for this recurrence could be a lack of understanding of bone deformity that might be forcing the child to adapt altered ankle joint and muscle mechanics (bone kinematics, cartilage contact parameters, muscle strain) during dynamic activities. In fact, the surgical treatment of fixed equinus does not consider any bone corrections and focus on muscle release or lengthening only. Being a dynamic pathology, it is critical to understand the in vivo effect of weak ankle joint musculature on joint mechanics and the resultant bone deformity. However, no such efforts have been made so far in the literature. With the advent of technology, researchers have developed and validated dynamic magnetic resonance imaging techniques to analyze i
Sponsor: University Hospital, Brest

Current Primary Outcome:

• Talocrural joint flexion, pronation, and internal rotations [ Time Frame: One year ]
  Talocrural (talus relative to tibia) joint rotations and translations will be compared between two cohorts.
• Subtalar joint flexion, pronation, and internal rotations [ Time Frame: one year ]
  Subtalar (calcaneus relative to talus) joint rotations and translations will be compared between two cohorts.
• Achilles tendon moment arm (MAAT) [ Time Frame: one year ]
  MAAT is defined as a perpendicular 3D distance between Achilles' tendon line of action and the Medial-lateral Calcaneal axis. Using calcaneal kinematics, MAAT value for each time frame will be quantified and compared between two cohorts.

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Ankle joint kinematics (joint angles) during walking [ Time Frame: one year ]
  Walking gait parameters (ankle, knee, and hip joint angles) will be correlated with primary outcome measures
• Knee joint kinematics (joint angles) during walking [ Time Frame: one year ]
  Walking gait parameters (ankle, knee, and hip joint angles) will be correlated with primary outcome measures
• Hip joint kinematics (joint angles) during walking [ Time Frame: one year ]
  Walking gait parameters (ankle, knee, and hip joint angles) will be correlated with primary outcome measures
• Talocrural joint contact area [ Time Frame: one year ]
  Joint contact mechanics measures and will be compared between cohorts.
• Talocrural joint contact centroid location [ Time Frame: one year ]
  Joint contact mechanics measures and will be compared between cohorts.
• Subtalar joint contact area [ Time Frame: one year ]
  Joint contact mechanics measures and will be compared between cohorts.
• Subtalar joint contact centroid location [ Time Frame: one year ]
  Joint contact mechanics measures and will be compared between cohorts.

Original Secondary Outcome: Same as current

Information By: University Hospital, Brest

Dates:
Date Received: February 10, 2016
Date Started: June 2016
Date Completion: November 2019
Last Updated: November 3, 2016
Last Verified: September 2016