The present invention relates to an apparatus for use in effecting relative movement between bones in a body of a patient and, more specifically, to an apparatus for effecting movement of bones in an arm of the patient relative to a shoulder of the patient.
An orthosis for stretching viscoelastic or soft tissue in a human body to regain joint movement and eliminate tissue contracture is disclosed in U.S. Pat. No. 5,285,773. The apparatus disclosed in this patent includes a pair of cuffs which are mounted on cuff arms. A drive assembly interconnects the cuff arms.
Another orthosis is disclosed in U.S. Pat. No. 5,503,619. The orthosis disclosed in this patent includes a pair of cuffs which are connected with cuff arms. A drive assembly interconnects the cuff arms. The orthosis disclosed in the aforementioned U.S. Pat. No. 5,503,619 is particularly well adapted for use in bending a patient""s wrist.
An orthosis for effecting relative movement between bones in an arm of a patient is disclosed in U.S. patent application Ser. No. 08/683,196, filed Jul. 18, 1996 by Peter M. Bonutti et al. and entitled xe2x80x9cOrthosisxe2x80x9d. The orthosis disclosed in the aforementioned U.S. patent application includes a first cuff which grips a wrist portion of the arm of a patient. A second cuff grips an upper portion of the arm of the patient. A drive assembly is provided to rotate the first cuff about an axis which extends along the lower portion of the arm of the patient. Operation of the drive assembly effects pronation and suppination of the hand of the patient.
A new and improved apparatus for effecting relative movement between bones in a body of a patient includes a first cuff which grips a lower portion of an arm of the patient. A second cuff grips an upper portion of the arm of the patient. A drive assembly is operable to rotate the first cuff and a humerus bone in the arm of the patient about a central axis of the humerus bone. This results in a stretching of viscoelastic tissue connected with a head end portion of the humerus bone.
The extent of stretching of the viscoelastic tissue connected with a humerus bone in the arm of the patient may be maximized by interrupting operation of the drive assembly to allow the viscoelastic body tissue to relax. After the viscoelastic body tissue has relaxed, the drive assembly is again operated to further rotate the first cuff and further stretch the viscoelastic body tissue connected with the humerus bone.
A secondary drive assembly is provided to pivot the humerus bone in the arm of the patient about the head end portion of the humerus bone. This moves an arcuate surface on the head end portion of the humerus bone into alignment with an arcuate surface of a glenoid cavity in a scapula bone in the shoulder of the patient. The secondary drive assembly is disposed beneath an axilla between the trunk and arm of the patient.