An inter-transverse process spacer device for placement between two adjacent transverse processes, includes a spacer member with deformable first and second ends and may include a connector. The inter-transverse process spacer device may also include a flexible, fillable container for containing an injectable material that is compressible following implantation. The container is impermeable to the material it will be filled with. A structural mesh, for example, made of PET fabric and interwoven shape-memory alloy wire, provides structure for and containment of the container, as well as shape control of the inter-transverse process spacer device. The material can be injected into the container through a conduit. The inter-transverse process spacer device is sized and configured to allow for placement between adjacent transverse processes to produce a lateral force for correcting a spinal deformity. A method for correcting a spinal deformity using the inter-transverse process spacer device is also disclosed.