SYSTEM AND METHOD FOR ORTHOPEDIC DYNAMIC DISTRACTION
At least one embodiment is directed to a dynamic distractor ( 100 ) for distracting bones of a muscular-skeletal system. The dynamic distractor ( 100 ) comprises at least one sensor ( 108, 110 ), a handle ( 112, 804 ), a lift mechanism ( 302 ), and one or more alignment aids ( 502, 802 ). The position and measurement sensors ( 108, 110 ) are in communication with the processing unit ( 406 ) to display, process, and store measured data. The process of distraction separates two components such as bones of the muscular-skeletal system. A gap created by dynamic distractor ( 100 ) is adjustable under load. The at least one sensor ( 108, 110 ) can provide loading, loading differential, and position information as well as other measured parameters. Dynamic distractor ( 100 ) can aid in the alignment of the skeletal systems and to verify that alignment is correct. Soft tissue release can be performed with dynamic distractor ( 100 ) in place over a full range of motion.
1 . A distractor system comprising:
a first support structure having a superior surface;
a second support structure having an inferior surface;
a lift mechanism coupled to the first and second support structures to adjustably separate the first support structure from the second support structure; and
a sensor overlying one of the superior surface or the inferior surface to measure a parameter of the muscular-skeletal system.
2 . The system of claim 1 further including:
a first cavity in the superior surface of the first support structure;
a second cavity in the superior surface of the first support structure;
a first sensor fitted in the first cavity having a surface for receiving a medial condyle; and
a second sensor fitted in the second cavity having a surface for receiving a lateral condyle.
3 . The system of claim 1 further including a handle operatively coupled to the lift mechanism.
4 . The system of claim 1 further including a rod operatively coupled to the handle.
5 . The system of claim 4 where the rod is used to align one or more bones of the muscular skeletal system.
6 . The system of claim 4 further including a cutting block coupled to the rod.
7 . The system of claim 1 where the lift mechanism comprises:
a scissor mechanism coupled to an interior surface of the first and second support structures; and
a threaded shaft operatively coupled to the scissor mechanism where rotation of the threaded shaft raises and lowers the scissor mechanism thereby increasing or decreasing a gap between the first and second support structures.
8 . The system of claim 1 further including a handle operatively coupled to the lift mechanism where at least one laser pointer is coupled to the handle and directed to at least one target to aid in alignment.
9 . The system of claim 1 further including
a processing unit;
a communication circuit coupled to the processing unit; and
a display operatively coupled to the processor for displaying information received wired or wirelessly from the sensor.
10 . The system of claim 1 where the sensor measures one of force, pressure, or load.
11 . A method of distracting a muscular-skeletal system comprising the steps of:
placing a sensor in the dynamic distractor;
inserting a dynamic distractor between a first surface and a second surface of the muscular-skeletal system;
expanding the dynamic distractor to create a gap of a predetermined height;
measuring a parameter of the muscular-skeletal system at the predetermined height; and
removing the sensor from the dynamic distractor.
12 . The method of claim 11 where the step of expanding the dynamic distractor further includes the steps of:
expanding the dynamic distractor until the loading is within a predetermined range;
measuring the distance from the superior surface to the inferior surface of the dynamic distractor when the loading on the dynamic distractor is within the predetermined range; and
selecting an insert thickness.
13 . The method of claim 11 further including the steps of:
transmitting measurement data from the sensor to a processing unit;
adjusting the loading applied by the first and second surfaces of the muscular-skeletal system using soft tissue release with the dynamic distractor in place.
14 . The method of claim 11 further including the steps of:
measuring loading on at least two regions of the first or second surfaces of the muscular-skeletal system; and
adjusting the differential loading using soft tissue release to modify a balance between the at least two regions with the dynamic distractor in place.
15 . The method of claim 11 further including the steps of:
generating relational positioning information using one or more accelerometers;
transmitting the relational positioning information to a processing unit;
emitting a signal from the dynamic distractor to a first target;
emitting a signal from the dynamic distractor to a second target where a position of the first target, the dynamic distractor, and the second target correspond to a mechanical axis of the muscular-skeletal system; and
measuring misalignment of the first and second surfaces to the mechanical axis.
16 . A distractor system comprising:
a first support structure having a superior surface;
a second support structure having an inferior surface;
a lift mechanism coupled to the first and second support structures to adjustably separate the first support structure from the second support structure;
at least one cavity in either the superior or inferior surfaces; and
a sensor in the at least one cavity to measure a parameter coupled thereto.
17 . The system of claim 16 further including:
a handle coupled to the lift mechanism; and
a cutting block;
an uprod coupled between the handle and the cutting block to align and stabilize the cutting block along a mechanical axis.
18 . The system of claim 16 where the cutting block and uprod are removed from the distractor system and where a rod is coupled to the handle to aid in alignment verification.
19 . The system of claim 16 further including a handle operatively coupled to the lift mechanism where at least one laser pointer is coupled to the handle and directed to at least one target to aid in alignment.
20 . The system of claim 16 further including
a processing unit;
a communication circuit coupled to the processing unit; and
a display operatively coupled to the processor for displaying information received wired or wirelessly from the sensor.
21 . The system of claim 16 where the lift mechanism comprises:
a scissor mechanism coupled to an interior surface of the first and second support structures; and
a threaded shaft operatively coupled to the scissor mechanism where rotation of the threaded shaft raises and lowers the scissor mechanism thereby increasing or decreasing a gap between the first and second support structures.