Given the task definition and input, reply with output. Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Abstract: Early mobilisation after arthroplasty of the knee sometimes results in wound breakdown. The two commonly used incisions, the anterior midline and the medial parapatellar incisions, were compared in order to determine which had the best potential for wound healing. Study of the cleavage lines around the knee demonstrated that the medial parapatellar incision lies parallel to the lines, whilst the anterior midline incision lies perpendicular to them. In addition, the medial parapatellar wound was found to be subjected to significantly less tension during flexion; after arthroplasty it can be expected to heal faster and to be less liable to disruption during early mobilisation.
Biomechanics