2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress Paper


Influence of Soft Tissue Status and Repairability on Recuperation of Internal Rotation and Internal Rotation Strength After Shoulder Arthroplasty

Olivier Verborgt, MD, PhD, Antwerpen BELGIUM
Anke Claes, PT, antwerp BELGIUM
Annelien De Mesel, PT, antwerp BELGIUM
Alexander Vervaecke, MD, Antwerpen BELGIUM

Orthopaedic Center Antwerp and University Hospital Antwerp, Antwerp, Antwerp, BELGIUM

FDA Status Cleared

Summary

Previous open surgery affected the speed of the recovery process but not the final result for either aTSA or RSA while subscapularis repairability did not affect the recuperation of internal rotation, internal rotation strength or functional outcome in RSA.

Abstract

Background

Pre-operative internal rotation and internal rotation strength of the shoulder is frequently limited in patients with arthritis and it remains difficult to predict the post-operative improvement after a shoulder replacement. Patients’ factors and modifications in implant design and implant position have been shown to affect this, but the influence of the pre-operative status or repairability of the soft tissues are not clear.

Aim

The objective of this study was to analyze the influence of previous open surgery and subscapularis repairability in anatomic (aTSA) and reverse arthroplasty (RSA) on the post-operative recuperation of internal rotation and internal rotation strength.

Methods

A prospective cohort study of 109 shoulder arthroplasty patients (76 men, 33 female; mean age 69 yr) with a consistent surgical technique and component implantation was done. There were 46 aTSA and 63 RSA, 81 were primary arthroplasties and 28 patients had previous open surgery (ORIF or open soft tissue repairs, no revision arthroplasties); the subscapularis was irreparable in 21 patients. Internal rotation range of motion (ROMendo), internal rotation strength (Fendo), SPADI and Constant-Murley score were measured pre-operatively, and post-operatively at 6 weeks, 3 months, 6 months and 12 months.

Results

Overall, the mean ROMendo gradually improved from 21° to 34° (P<0.05), Fendo increased from 11 lbs to 14 lbs (p<0.05). For aTSA, the improvement was faster and significantly better for ROMendo (18° to 33°) and Fendo (14,7 lbs to 16.8 lbs)(P=0.01) than for RSA (ROMendo: 23° to 28° and Fendo: 9.7 lbs to 12.6 lbs). Previous open surgery affected the recovery (P<0.001) but not the end-result for ROMendo or Fendo for both aTSA (p=0.78) and RSA (p>0.05). In RSA, subscap repairability did not affect post-operative ROMendo or Fendo. Overall, post-operative SPADI was significantly better in aTSA than in RSA (P=0.01) but there was no difference in post-operative Constant-Murley score (p>0.05). Post-operative SPADI and Constant-Murley scores were not affected by previous open surgery or subscap repairability in RSA (p>0.05).

Conclusion

Internal rotation and internal rotation strength increased during rehabilitation after shoulder arthroplasty. The improvement is faster and better after aTSA than after RSA, and this results in better overall functional outcome scores in aTSA. Previous open surgery affected the speed of the recovery process but not the final result for either aTSA or RSA. Subscapularis repairability did not affect the recuperation of internal rotation, internal rotation strength or functional outcome in RSA.