Non-functional teres minor, other factors linked with good internal rotation after reverse shoulder arthroplasty
LISBON, Portugal — Preoperative inferior glenoid inclination, a sphere that has a glenoid offset of at least 6 mm and a non-functional teres minor were among the factors that investigators from Tours, France found correlated with good postoperative internal range of motion after reverse shoulder arthroplasty performed for massive cuff tears with or without osteoarthritis.
Luc Favard, MD, and colleagues performed a prospective single-center study of 36 patients to determine factors that would be most helpful for predicting postoperative shoulder internal rotation (IR) after reverse shoulder arthroplasty.
They measured shoulder range of motion parameters preoperatively and then used a deltopectoral surgical approach. Postoperatively, investigators studied patients’ shoulders radiologically. Active IR was defined as a patient who could reach to L3 or higher easily, and difficult or low IR was defined as a patient who was unable to reach to L3.
Patients with good postoperative active IR differed significantly from those with low internal for the factors mentioned, as well as for BMI. Results showed BMI was 25 kg/m2 in the good IR group vs. 29 kg/m2 in the low IR group, which was statistically significantly different.
“Moreover, we have been surprised to see that the teres minor has an effect, because if the teres minor is not functional, meaning a fatty infiltration grade 3 or 4, we have a significantly better internal rotation,” Favard said.
Twenty-three patients underwent subscapularis repair; however, the findings showed the condition of the subscapularis, nor its repair, did not contribute to recovery of good active IR.
Weaknesses of the study were its 6-month follow-up, inclusion of two operating surgeons and limited number of patients. Its strengths are noteworthy, Favard said, “because it is a prospective study with a precise analysis of the mobility and a precise analysis of radiologic parameters.” – by Susan M. Rapp
Favard L, et al. Abstract 904. Presented at: EFORT Annual Congress; June 5-7, 2019; Lisbon, Portugal.
Disclosure: Favard reports he is a paid consultant for Tornier and Wright Medical Technology and received intellectual property royalties from and is a paid presenter or speaker for Wright Medical Technology.