Functioning and Disability
Gabrielle Gour-Provencal, MD
Physiatrist
CHU Sainte-Justine
Montreal, Quebec, Canada
coby Rangsitratkul, MD
MD
Université de Montréal
Montreal, Quebec, Canada
William Vandal, MD
MD
Université de Montréal
Montreal, Quebec, Canada
Peter Glavas, MD
Orthopedist
CHU Sainte-Justine
Montreal, Quebec, Canada
Jean-Philippe Coté, BS
Orthesist/prosthesist
CHU Sainte-Justine
Montreal, Quebec, Canada
Marie Laberge, MD
Physiatrist
CHU Sainte-Justine
Montreal, Quebec, Canada
We report the case of a 9-year-old boy who underwent a modified Ertl transtibial amputation of his right lower limb due to an early-life ischemic complication following a Rashkind procedure.
Case Description:
Prosthetic fitting proved challenging due to bone overgrowth that caused significant pain when weightbearing. Various modifications to the prosthesis were attempted over the years to maximize the patient’s function while minimizing his pain. Around age 9, a custom-made molded laminated silicon liner with extra silicone padding was introduced, which we hypothesize not only alleviated pain and improved the child’s functional abilities but also contributed to remarkable bone remodeling and the resolution of the overgrowth.
Discussions:
In the human body, osteocytes, or bone cells, form lacunae and canaliculi, a structure that responds to mechanosensitive signaling pathways (13). It has been shown that mechanical forces and movement result in fluid shear stress which in turn are translated into biochemical signals that control cell growth, differentiation, apoptosis, and migration. Thus, mechanical forces applied to the body directs cell responses of the osteocyte networks to promote adaptation to the environment (14). We believe this custom-made liner (combined with his custom-made socket) allowed for better mechanical force distribution, which decreased traction at the distal end of the residual limb. By decreasing traction at the residual limb, we believe it induced a morpho-structural bone change of the residual limb resulting in bone overgrowth remodeling.
Conclusions:
This case report demonstrates that an optimal fitting with a custom-made liner and socket, which minimizes traction at the distal end of the residual limb, is an interesting therapeutic option that could potentially decrease occurrence and recurrence of bone overgrowth by altering the mechanosensitive response of the osteocyte networks and thus reduce the need for surgical interventions as well as optimize the patients’ function.
