Joint Replacement
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Procedures
(Information is obtained from BIOMET Inc.)
First, the patient is given either a general endotracheal or interscalene block anesthesia, and an incision is made slantwise across the shoulder, starting from the distal third of the clavicle. Next, the tendons and muscle in the region are moved aside with blunt retractors. To facilitate ease of mobilization of the humerus, the subscapularis tendon is divided by electrocautery and marked with a non-absorbable suture for later identification and repair.
The capsule is then divided superiorly, and the desired amount of the humeral head is removed, while making sure that the rotator cuff is not injured. Next, the resistance from the cortical bone is measured using six different diameters, and the humeral inserter handle is attached to the chosen humeral stem. The humeral component is then carefully driven into the humeral canal, and the humeral inserter is removed.
Bi-Polar Hemi Arthroplasty:
For a bi-polar hemi arthroplasty, the next step is to size the head and shell and position them on the stem. The subscapularis is then repaired with non-absorbable sutures. The arm is then experimentally rotated to see the range of rotation, and to examine the suture line tension. The shoulder is then closed, and a sling is applied.
http://www.centerpulseorthopedics.com/us/patients/knee/arthritis/index
Total Shoulder Arthroplasty:
For total shoulder arthroplasty, the next step is to size and position the modular head components on the stem. Once a particular head size is selected, it is removed by dislocating the shoulder. The condition of the glenoid is inspected, and if replacement is necessary, then the patient's glenoid is removed and replaced with either a polyethylene or metal glenoid. A small drill perforates the bone surface for cement fixation of the glenoid. The bone is cleaned and dried before the cement is applied. The glenoid is then inserted and impacted into place, and excess cement is removed and allowed to dry. The modular head is then inserted into place with light hammer strikes. Finally, the subscapularis is repaired with non-absorbable sutures. The subcutaneous tissue is repaired with absorbable sutures. The skin is closed with staples, and the arm is placed in a sling.
Postoperative Care :
The first day after the surgery, depending on comfort, the patient is permitted to rotate the arm out of the sling. On the second day after surgery, rotation is assisted by passive and active flexion and rotational exercises. Pulley exercises start on the third day. The patient can be discharged after at least 120 degrees of active-assisted forward elevation has been achieved. Exercises are then continued on an outpatient basis.
In terms of rehabilitation of the shoulder, it is important to first attain range of motion before strength. A warm moist towel may be applied to the shoulder before exercising to help relax the muscles and increase circulation. The shoulder must be exercised five times each day. The condition of the patient should be monitored by the physician to achieve optimal rehabilitation of the shoulder.
For a more detailed explanation of the surgical procedure, please refer to these sites:
http://www.biomet.com/products/filedownload.cfm?d=0A03 http://www.biomet.com/products/filedownload.cfm?d=0907060D
Created by: Blair Smith, Connie Lee, Daniel Solomon, Matthew Whitson and Stephanie Chang
Date last modified: 5/2/2004