Modified Frailty Index bests other tools at predicting outcomes after rotator cuff repair

The Modified Frailty Index (MFI) is better than the Clinical Frailty Scale (CFS) and Charlson Comorbidity Index (CCI) at predicting postoperative functional outcomes in patients undergoing arthroscopic rotator cuff repair, according to a recent Singapore study.

“Patients with higher MFI scores had slower functional improvement postoperatively but eventually attained functional outcome scores comparable with those of their counterparts with lower MFI scores at 24 months postoperatively,” the researchers said.

The researchers conducted a retrospective analysis of 340 patients who had undergone unilateral cuff repair, whose frailty was assessed using the MFI, CFS, and CCI. Functional outcomes were evaluated using the Oxford Shoulder Score (OSS), Constant Shoulder Score (CSS), and University of California Los Angeles (UCLA) Shoulder Score. A visual analogue scale was used for pain measurement at 3, 5, 12, and 24 months postoperatively.

Outcomes differed according to frailty scores. OSS (p=0.003) and VAS (p<0.001) increased significantly with increasing MFI scores, while CSS (p=0.001) and UCLA shoulder scores (p<0.001) decreased progressively. Only OSS (p<0.001) and UCLA shoulder scores (p=0.001) differed significantly across the CFS ratings. None of the outcome measures were associated with CCI. [Orthop J Sports Med 2021;9:23259671211005091]

Multiple linear regression analysis showed that MFS was consistently significantly correlated with postoperative outcomes. For instance, MFI could predict OSS at 6 (B, 23.230), 12 (B, 19.267), and 24 months (B, 12.962), as well as CSS at 6 (B, –55.198) and 12 months (B, –33.688; p<0.05 for all).

Similarly, MFI shared significant correlation with UCLA shoulder scores at 3 (B, –7.106), 6 (B, –11.445), and 12 months (B, –11.596), as well as with VAS at 6 (B, 4.730) and 12 months (B, 5.413). In comparison, CFS was significantly associated with CSS, UCLA shoulder score, and VAS only at 12 months, while no such interactions were detected for CCI at any time point.

Further stratifying analysis according to MFI scores revealed that across all tested inventories, higher MFI scores correlated with poorer outcomes.

Notably, a significant sex effect was also reported for OSS, CSS, and the UCLA shoulder score, with men reporting better functional outcomes. Such an effect persisted until 24 months after the procedure.

“One explanation for the main finding in this study is the difference in the approaches among the MFI, CFS, and CCI in quantifying the frailty status of a patient,” the researchers explained, pointing out that MFI is a holistic and multidimensional tool that takes into account both a patient’s comorbidities and functional independence.

“The findings from our study suggest that a multidimensional assessment of frailty (including both functional status and comorbidities) is important in determining functional outcomes after arthroscopic rotator cuff repair,” they added.