Joseph King, MD
Improvement in external rotation following Reverse Shoulder Arthroplasty (RSA) is an important topic. Now I educate my patients preoperatively as I am not very good at predicting post-operative external rotation (ER). This study adds significantly to the literature regarding expected improvement in external rotation following RSA and has helped me educate my patients better prior to RSA.
Carofino et al. examined 608 RSA patients performed for cuff tear arthropathy or arthritis with cuff deficiency and stratified them by preoperative external rotation into three groups: normal active external rotation (ER ≥ 30°), weak external rotation with a ≥ 20° lag, and stiffness with external rotation (ER ≤ 20°).1 All implants used a medial glenoid and lateral onlay humeral design (Exactech Equinoxe®, Gainesville, FL).
Patients with external rotation stiffness showed the best improvements in all functional outcome scores (Constant, ASES, SST, UCLA and SPADI); and active ROM parameters tested as all being statistically significant except for the ASES and SPADI scores.
In addition, all groups had improvements in all outcome scores and active ROM except for similar pre and post-operative external rotation in the patients with normal preoperative external rotation. This shows that those with preoperative external rotation weakness had significant improvement in active external rotation (mean 16° improvement in this study). Those with preoperative external rotation had the best improvements in external rotation of 35°.
This study has improved my preoperative education for RSA patients; now I tell my patients that are weak and stiff that their active external rotation will likely improve after RSA (stiff patients more so than weak patients). On the other hand, the patients with good active preoperative external rotation will unlikely gain much external rotation. This is an important notation for preoperative patient counseling in patients with limited external rotation who often complain of some problems with ADLs, such as washing or combing their hair.
I think it is equally important for patient counseling to let the patients know that if they have good preoperative external rotation, their rotation will unlikely improve and could actually be worse. In my personal experience with patient counseling, I have found that telling the patients these expectations ahead of time has greatly reduced post-operative patient complaints relating to rotation.
This study excluded latissimus dorsi transfer patients, which raises the question of how the rotation improvement of this implant design compares to patients with a latissimus dorsi transfer. One systematic review of RSA with latissiums dorsi transfer showed an average external rotation improvement from -7.4° to 22.9° (30° improvement), which included 98 RSAs, but this study did not mention the types of RSA designs used.2
The external rotation improvement seen in their study was less compared to the patients with stiff external rotation using a medial glenoid and lateralized humeral implant design in Carofino et al.1, but it was better compared to those who had external rotation weakness with a lag of over 20°.
One randomized controlled study of 28 RSA patients with a combined loss of elevation and external rotation (CLEER) showed no difference in external rotation, including activities of daily living requiring external rotation score between patients with and without latissimus dorsi transfer, although two different implants were used in this study.3 In addition, one study reported on a total of 26 RSA patients that while a latissimus dorsi transfer did improve active external compared to controls, it also led to a higher chance of an internal rotation deficit.4
Implant design has also been considered to be a factor in the ability to improve external rotation. Berglund et al. showed that when using a lateralized glenoid and medial humerus RSA design, external rotation improvement was not affected by preoperative CLEER.5 All of these studies suggest that implant design, as well as preoperative external rotation, will ultimately affect the patient’s post-operative active external rotation improvement and that latissimus dorsi transfer is not necessary to restore functional external rotation in RSA.
- Carofino B, Routman H, Roche C. The influence of preoperative external rotation weakness or stiffness on reverse total shoulder arthroplasty. JSES Int. 2020 May 6;4(2):382-387. doi: 10.1016/j.jseint.2020.02.006.
- Wey A, Dunn JC, Kusnezov N, Waterman BR, Kilcoyne KG. Improved external rotation with concomitant reverse total shoulder arthroplasty and latissimus dorsi tendon transfer: A systematic review. J Orthop Surg (Hong Kong). 2017 May-Aug;25(2):2309499017718398. doi: 10.1177/2309499017718398.
- Young BL, Connor PM, Schiffern SC, Roberts KM, Hamid N. Reverse shoulder arthroplasty with and without latissimus and teres major transfer for patients with combined loss of elevation and external rotation: a prospective, randomized investigation. J Shoulder Elbow Surg. 2020 May;29(5):874-881. doi: 10.1016/j.jse.2019.12.024.
- Flury M, Kwisda S, Kolling C, Audigé L. Latissimus dorsi muscle transfer reduces external rotation deficit at the cost of internal rotation in reverse shoulder arthroplasty patients: a cohort study. J Shoulder Elbow Surg. 2019 Jan;28(1):56-64. doi: 10.1016/j.jse.2018.06.032. Epub 2018 Sep 14.
- Berglund DD, Rosas S, Triplet JJ, Kurowicki J, Horn B, Levy JC. Restoration of External Rotation Following Reverse Shoulder Arthroplasty without Latissimus Dorsi Transfer. JB JS Open Access. 2018 Apr 19;3(2):e0054. doi: 10.2106/JBJS.OA.17.00054. PMID: 30280137.
Jay J. King, MD, is an assistant professor at the University of Florida College of Medicine Department of Orthopaedics for general orthopaedics, shoulder and elbow surgery. He earned his medical degree at Drexel University in 2006 before completing his residency in orthopaedic surgery there, followed by a clinical research fellowship in orthopaedic oncology at the University of Pennsylvania in Philadelphia. He has published various works in national and international journals and is a member of various national and state orthopaedic organizations. He currently practices at the UF Health Orthopaedics and Sports Medicine Institute.