There are questions regarding the rehabilitation after a reverse total shoulder (rTSA).
(1) Does early postoperative motion affect bone ingrowth into the implants, glenohumeral stability, healing of the subscapularis, or the risk of acromial / spine stress fractures?
(2) Does postoperative sling immobilization contribute to loss of strength, increased risk of falling, and the patient's lack of independence in performing activities of daily living?
(3) If there is a concern for postoperative instability, is it better to immobilize the shoulder to encourage soft tissue healing or - recognizing that most rTSA dislocations are anterior - would it be better to improve stabilization by early strengthening of the anterior deltoid and the remaining cuff musculature along with passive external rotation to avoid internal rotation tightness?
The evidence needed to definitively answer these questions is lacking.
Here's what we think we know:
Traditionally surgeons have immobilized patients after rTSA for six weeks with the intent of protecting the deltoid and the repaired subscapularis, minimizing the risk of dislocation, and minimizing the risk of acromial/spine fracture. They then progressed motion, strength and use of the arm, cautioning patients about pushing up with the arm in extension (as in getting up from bed or chair) and alerting them to the symptoms of acromion and spine fracture.
Recently, however, there is interest in reducing or eliminating the immobilization after the first few postoperative days. Here are some reasons why early mobilization might be considered
(1) Early mobilization enables the patient to be more functional and independent; avoidance of a sling may help with balance and reduction of fall risk.
(2) Early use and gentle strengthening may increase the tone in the deltoid and residual cuff muscles leading to increased stability of the rTSA through concavity compression.
(3) The rTSA is at greatest risk for dislocation when the arm is extended, adducted and internally rotated. The shoulder is typically stable with active use of the arm in flexion, abduction and moderate external rotation. These positions allow many activities of daily living.
(4) The risk of acromial/spine fractures is driven primarily by diagnosis (cuff deficiency), inflammatory arthropathy, bone density, and female sex with some theoretical considerations regarding component position. The relationship of rehabilitation protocol to the risk of these fractures is unclear. It is furthermore unclear whether 6 weeks of immobilization makes the acromion and spine less likely to fracture. In patients at high risk for these fractures, an early gradual increase in activities that load the acromion might be the safest route.
(5) There may be a concern that early rehabilitation could result in micromotion between the implants and the bone that predisposes to loosening. However, modern fixation methods with secure compression of the properly positioned baseplate into well prepared glenoid bone seems to minimize baseplate failure. Again it's unclear whether 6 weeks of immobilization improves bone ingrowth.
When looking for Level I evidence on the effect of post rTSA rehabilation on rTSA outcome I found only two studies, each concluding that early mobilization (including no immobilization) is safe and does not increase complication rates, with comparable or superior outcomes to traditional immobilization protocols.
Three-week immobilization vs. no immobilization in primary reverse total shoulder arthroplasty: a randomized controlled trial. Patients with cuff deficient shoulders having rTSA were randomized to either 3 weeks in a sling or to have no immobilzation after surgery and freedom to use their shoulder for "personal hygiene and simple household tasks." When a subscapularis repair was performed there was no attempt to protect it. No specific rehabilitation program was described. Patients were followed for two years. No complications were noted in either group. There were no significant differences in VAS or Constant scores between the groups. The authors point out that avoidance of sling immobilzation enhanced patients' ability to care for themselves without relying on the assistance required when sling immobilization was used.
A randomized single-blinded trial of early rehabilitation versus immobilization after reverse total shoulder arthroplasty randomly assigned patients to either a delayed-rehabilitation group (no passive or active motion for 6 weeks) or early-rehabilitation group (immediate physical therapy with passive and active motion and weaning of sling use as tolerated, but no resistance training for 6 weeks). At a minimum of 1 year, no clinically significant differences were found between groups for any postoperative measure. No differences in rate of complications, notching, or narcotic use were noted between groups. Regarding complications, the immediate-therapy group
had 1 glenosphere dissociation requiring surgery, 1 acromial stress fracture managed
nonoperatively, and 1 postoperative pulmonary embolism.
The delayed-therapy group had 1 prosthetic shoulder
dislocation requiring surgery, 1
periprosthetic fracture, 1 deep
venous thromboembolism, and 1 case of lymphedema. As in the forgoing article, these authors point out that early initiation of postoperative rehabilitation may benefit the elderly population by avoiding the limitations of prolonged immobilization postoperatively.
Another article, not a randomized controlled trial, is of interest.
Accelerated rehabilitation following reverse total shoulder arthroplasty was a comparison of three different rehabilitation programs used by the surgeon over different time periods. Between July 2005 and October 2017, a total of 357 consecutive rTSA in 320 patients underwent a
primary rTSA and were included in the study. Patients were divided into 3 groups depending on rehabilitation protocol being used at three different time periods. These protocols were changed from (1) 6 weeks of immobilization prior to 2013, (2) shortening of the immobilization period
from 6 to 3 weeks in 2013, and (3) change from 3 weeks of immobilization to no immobilization at all in 2015.
In the "no immobilization" program, pendulums, assisted elevation and external rotation, and passive internal rotation in abduction were started a few days after surgery. Assisted elevation was progressed to active elevation as tolerated.
No statistically significance differences were observed in Constant score, subjective shoulder value, patient satisfaction, pain, or range of motion between the 3 groups. The complications are shown below.
The authors call attention to the periprosthetic fractures that may be due to falls or scapular spine fractures and suggest that without a sling, patients may have better
proprioception, balance and less tendency to fall. It is also possible that the surgeon became more skilled and that this was reflected in the lower complication rate seen in the more recently performed surgeries.Comment: For each patient having a rTSA the surgeon has the opportunity to decide what rehab approach is best suited to that patient. Here are some questions the surgeon needs to consider:
If there is a concern about instability, is it preferable to immobilize the shoulder to optimize healing or is it better to get the tone and strength back in the compressing musculature?
If there is a concern about acromion/spine fracture, is it preferable to dedicate 6 weeks of rest, letting the bone get used to its new environmnent, or is it better to start gently progressing the loads experienced by the acromion and spine soon after surgery, giving them a chance to adapt?
If there is a concern about baseplate loosening, is it preferable to dedicate 6 weeks to allow for bone ingrowth or are current fixation methods and implants sufficient to allow for early motion?
If there is a concern about fall risk, is it preferable to keep the arm in a "protective sling" for 6 weeks or is it better to allow the arm to be free to optimize balance?
If there is a concern for optimizing the patient's independence in activities of daily living, is it safe to allow them to start using the arm soon after surgery?
And finally, if there is early evidence of feelings of instability or acromial/spine stress reaction, what modifications in rehabilitation should be considered?
When is it time to get moving?
Red tailed hawk taking off
October 2021
