- See:
-
Surgical Technique:
-
Anterior Approach to Shoulder
- Discussion:
- indicated for end stage DJD or RA shoulder involvement;
- contra-indications to shoulder arthroplasty include combined rotator cuff / deltoid paralysis and recent joint infection;
- in these rare circumstances,
arthrodesis may be considered;
- may occur as a consequence of recurrent shoulder instability;
- references:
-
Shoulder Arthroplasty in Patients with a Prior Anterior Shoulder Dislocation.
Results of a Multicenter Study.
-
Dislocation arthropathy of the shoulder
- Exam:
- note the degree both preoperatively and postoperatively of scapulothoracic to glenohumeral motion;
- as noted by RJ Friedman 1998, patients with DJD of the shoulder reverse the normal 1:2 ratio of scapulothoracic to glenohumeral motion
ratio (and in most cases this is not changed w/ arthroplasty);
- excessive external rotation:
- may indicated deficiency of the subscapularis in which case, the subscapularis may have to be augmented w/ an Achilles tendon allograft;
- restricted external rotation:
- may indicated severe wear of the posterior glenoid, in which case the glenoid may have to be reamed to a more neutral version;
- Radiographs:
- AP radiograph in internal and external rotation
-
axillary view to assess glenoid deficiencies;
- even if glenoid appears normal on the axillary view, any posterior subluxation may
indicate excessive poserior glenoid wear;
- CT scan:
- may allow better assesment of the glenoid version and possible posterior glenoid erosion;
- ref:
The use of computerized tomography in the measurement of glenoid version.
-
osteoarthritic changes:
- prominent osteophyte at the inferior margin of the humeral head or glenoid is characteristic;
- mild arthrosis: inferior osteophyte less than 3 mm in length;
- moderate arthrosis: inferior osteophyte between 3-5 mm in length, irregularity of the joint line and subchondral sclerosis;
- severe arthrosis: inferior osteophyte measuring more than 5 mm or if there is joint incongruity;
- Operative Considerations: hemiarthroplasty vs
total shoulder arthroplasty:
- preoperative planning must take the following in consideration: status of rotator cuff, bone stock, asymmetric wear, and type and extent of soft tissue contractures;
-
expectations:
- patients should not generally expect to achieve elevation above 130 deg;
- patients should also understand that improvements in function will continue for upto 18 months postoperatively;
-
poor prognositic indicators:
- osseous deficiency of the humeral head or glenoid;
- non-functioning rotator cuff or deltoid;
- shoulder instability;
- previous anterior acromioplasty and excision of the CA ligament;
- may allow antero-superior dislocation;
- consider reconstruction of the CA ligament and pectoralis transfer during the arthroplasty;
-
examination findings:
- excessive external rotation:
- may indicated deficiency of the subscapularis in which case, the subscapularis may have to be augmented w/ an Achilles tendon allograft;
- restricted external rotation:
- may indicated severe wear of the posterior glenoid, in which case the glenoid may have to be reamed to a more neutral version;
-
glenoid bone loss: (see
glenoid component);
- many pts w/ OA have posterior glenoid bone loss, & pts w/
RA may have central or medial erosion;
- if posterior glenoid bone loss is present, consider altering amount of humeral retroversion from the normal 35 deg to a less retroverted position;
- this should prevent posterior instability and eccentric glenoid loosening;
- references:
-
Glenoid bone-grafting in total shoulder arthroplasty.
-
The Effect of Humeral Component Anteversion on Shoulder Stability with Glenoid Component Retroversion.
-
massive rotator cuff tear:
- see
hemiarthroplasty in the rotator cuff deficient patient
- references:
-
Replacement arthroplasty of the rotator cuff deficient shoulder.
-
Prosthetic replacement of the shoulder for the treatment of defects in the rotator cuff and the surface of the glenohumeral joint.
- Surgical Technique:
-
hemiarthroplasty
-
total shoulder arthroplasty:
- Complications of Shoulder Arthroplasty:
The use of computerized tomography in the measurement of glenoid version.
Unconstrained shoulder arthroplasty. A five-year average follow-up study.
The effect of articular conformity and the size of the humeral head component on laxity and motion after glenohumeral arthroplasty. A study in cadavera.
Neer hemiarthroplasty and Neer total shoulder arthroplasty in patients fifty years old or less.
Long Term Results.
JW Sperling et al.
JBJS Vol 80-A. No 4. Apr 1988.
Prospective analysis of total shoulder arthroplasty biomechanics.
RJ Friedman MD.
The American Journal of Orthopaedics. Apr 1997. p 265.
Shoulder Arthroplasty with or without Resurfacing of the Glenoid in Patients Who Have Osteoarthritis.
GM Gartsman MD
JBJS Vol 82-A. No 1. Jan 2000. p 26.
Primary Hemiarthroplasty for Treatment of Proximal Humeral Fractures.
Copeland Surface Replacement Arthroplasty of the Shoulder in Rheumatoid Arthritis.
Preoperative Factors Associated with Improvements in Shoulder Function After Humeral Hemiarthroplasty.
A Comparison of Pain, Strength, Range of Motion, and Functional Outcomes After Hemiarthroplasty and Total Shoulder Arthroplasty in Patients with Osteoarthritis of the Shoulder.
Compaction Bone-Grafting in Prosthetic Shoulder Arthroplasty.
