A needle knife device and system for cutting soft tissue under skin of a patient are provided. The needle knife can include an elongated needle including a lumen and a beveled point configured to allow the elongated needle to be inserted transcutaneously into the skin of the patient. The needle knife can also include a blade that is capable of being oscillated within the lumen of the elongated needle between a retracted position where the blade is disposed within the needle and a deployed position where the blade is disposed outside the needle beyond the beveled point. A motor unit can be operatively arranged with the blade and configured to oscillate the blade.