An interspinous implant kit includes a receiver body and multiple modules. The receiver body is adapted to be implanted between a spinous processes and includes corresponding saddles with an intermediate section therebetween. The intermediate section includes a module-receiving bay. The modules are configured to be interchangeably received in the bay. The first module may have a sensor adapted to generate measurement data indicative of at least one of forces acting on said receiver body and strain when mated to said receiver body. The second and third modules have mechanical material properties that are the of the same type, but different. One of the modules is advantageously mated to the receiver body to form a long-term implant.