a.
Description/Definition. Prosthetic replacement of the articulating surfaces of
the shoulder joint. There are three types of procedures commonly performed. The
total shoulder component in which the glenoid and humeral head are replaced
anatomically. The hemiarthroplasty which involves replacement of the humeral
head only. The reverse arthroplasty where the head of the humerus is replaced
by a prosthesis forming a socket and the glenoid is replaced with a ball
prosthesis.
b. Occupational
Relationship. Usually from post-traumatic arthritis, or from trauma resulting
in severe humeral head fractures.
c. Specific Physical Exam Findings. Stiff,
painful shoulder with limited function.
d. Diagnostic Testing Procedures: Radiographs
or CTs demonstrating humeral head fracture. CTs or diagnostic arthroscopy to
explore the status of rotator cuff and associated muscles and tendons, the
presence of arthritis or subluxation, or superior migration of the humeral
head. For revision procedures, a non-MRI arthrography or sonogram may be
important to better visualize associated pathology.
e. Surgical Indications. The decision of
whether a patient receives a total arthroplasty or a hemiarthroplasty depends
on the surgeon's discretion. Factors to consider are the presence of glenoid
erosions, humeral head subluxation and rotator cuff strength. There is good
evidence that total arthroplasties compared to hemi-arthroplasties results in
improved function in primary osteoarthritis of the shoulder, and relief of pain
two years post-operatively. Longer-term results are unknown.
i. Hemiarthroplasty may utilize a long stem
humeral head replacement or a resurfacing device. It may also be performed for
humeral head fractures. It has been used for severe arthritis unresponsive to
other treatments; however, there is some evidence that total shoulder
arthroplasty may yield a better functional outcome. In younger active patients
the eventual wear on the glenoid cartilage may cause decreased function over
time. Total arthroplasty may therefore be preferred in many cases. Partial
humeral head prosthesis may be useful in some cases. Cementless surface humeral
head replacement may be indicated in young patients with glenohumeral arthritis
and retained glenoid cartilage.
ii.
Total shoulder arthroplasty is usually performed in cases of severe arthritis
when all reasonable conservative measures have been exhausted without
sufficient return to activities of daily living. Arthroscopic surgery may be
considered in selected patients with a milder degree of arthritis. Arthroscopic
SLAP repair is usually not recommended in cases of severe arthritis. The
rotator cuff should generally be intact or repairable.
iii. Reverse arthroplasty is generally
considered a salvage procedure for patients over 70 with severe osteoarthritis,
massive rotator cuff tears and pseudo paralysis with integrity of the deltoid.
Complications rates may be in the vicinity of 10 percent of patients within the
first year following surgery. The long-term success of the prosthesis is not
known at this time.
iv. Reverse
prosthesis may also be the treatment for failed hemiarthroplasty with extensive
cuff tears and/or instability. Most literature confirms that the complication
rate is higher and the success rate lower when reverse arthroplasty is
performed on a previously operated joint, however, many patients demonstrate
good improvement with elevation, but not necessarily rotation. Bone loss may
increase the complication rate.
v.
Procedural complications may include humeral head subluxation or dislocation,
humeral and/or glenoid loosening, rotator cuff tear, fractures, stiffness,
painful glenoid erosion, transient nerve palsies, heterotopic ossification,
bone loss, and component mal-positioning.
vi. Revision surgery may be performed by an
orthopedic surgeon in cases with chronic pain and stiffness, painful glenoid
erosion, or difficulty with activities of daily living. Prior authorization is
required and a second opinion by a surgeon with special expertise in shoulder
surgery should usually be performed. In the case of a total failure of the
prosthesis, arthrodesis is the salvage procedure.
f. Operative Treatment: Prosthetic
replacement of the articular surfaces of the shoulder.
g. Post-operative Treatment:
i. Individualized rehabilitation program
based on communication between the surgeon and the therapist. Timing of passive
motion and active rehabilitation is dependent on the type of procedures
performed.
(a). Pool exercise initially under
therapists or surgeon's direction then progressed to independent pool
program.
(b). Progression to a home
exercise is essential. Therapy should continue for at least 10 weeks with
transition to home exercises at the beginning of each new phase of
therapy.
(c). Gradual resistive
exercise from 3 to 12 months, with gradual return to full activity at 6 to 12
months.
(i). Time frames for therapy
(excluding pool therapy).
(ii).
Optimum: 12 to 24 sessions.
(iii).
Maximum: 36 sessions. If functional gains are being achieved additional visits
may be authorized for the patient to achieve their functional goal.
ii. Reverse
arthroplasty patients may have a more rapid rehabilitation in some cases. Per
the recommendation of the surgeon the following therapies may take place: Sling
use for the first three weeks, ADLs at three to six weeks, and then gentle
strengthening.
iii. Should progress
plateau the provider should reevaluate the patient's condition and make
appropriate adjustments to the treatment plan. Other therapies may be employed
in individual cases.
iv. Gradual
return to full activity can occur between 6 to 12 months, depending on the
procedure.
v. Return to work and
restrictions after surgery may be made by an experienced primary occupational
medicine physician in consultation with the surgeon or by the
surgeon.