| 主权项 |
1. An apparatus comprising:
a cannula having a first end, a second end, and a channel extending between the first end and the second end, the cannula having a primary portion and a distal portion between the primary portion and the second end, the distal portion configured such that a second end of the channel is disposed at an angle relative to a first end of the channel; a penetrator having an enlarged head and a monolithic wire extending from the enlarged head to a pointed distal end, a first transverse dimension of less than 1.2 millimeters (mm), and a second transverse dimension that is larger than the first transverse dimension, the penetrator including a primary portion extending from the enlarged head toward the distal end, and a penetration portion extending from the primary portion to the distal end, where the first transverse dimension is in the penetration portion and the second transverse dimension is in the primary portion, the penetrator configured to be disposed in the channel of the cannula such that the penetrator is movable between a retracted position and an extended position in which the distal end extends beyond the second end of the cannula by a penetration distance of at least 5 mm that is limited by the enlarged head contacting the cannula; where the penetrator is configured to be moved from the retracted position to the extended position substantially without rotation of the penetrator to form in subchondral bone a microfracture having a depth of at least 5 mm. |
