2015 ISAKOS Biennial Congress ePoster #2427

The Effect of Myotendinous Retraction on Arthroscopic Repairability and Repair Integrity After Arthroscopic Rotator Cuff Repair

Katsutoshi Miyatake, MD, PhD, Yoshinogawa, Tokushima JAPAN
Yoshitsugu Takeda, MD, PhD, Komatsushima, Tokushima JAPAN
Koji Fujii, MD, PhD, Komatsushima, Tokushima JAPAN
Tokushima Red Cross Hospital, Komatsushima, Tokushima, JAPAN

FDA Status Not Applicable

Summary: This study showed the muscle retraction (MR) measured on MRI before ARCR had more effect on intraoperative repairability and postoperative cuff integrity compared with tendon shortening, and the combination of MR and Gouatallier grading appears to be a more powerful predictor for the intraoperative repairability and postoperative cuff integrity.

Abstract:

Purpose

Myotendinous retraction consisted by shortening of muscle and tendon fiber affects magnification of cuff tear size. Therefore, myotendinous retraction could be a limiting factor for successful rotator cuff repair in chronic cases. However, what extent the shortening of muscle and tendon contribute to the intraoperative repairability and repair integrity after arthroscopic rotator cuff repair (ARCR) has not been well documented. The purpose of this study was to investigate the effect of myotendinous retraction on intraoperative repairability and repair integrity after ARCR.

Methods

Ninty-nine patients (100 shoulders) (65male, 34female, mean age: 63.6 years) with medium or larger tears who underwent ARCR were recruited. To evaluate the myotendinous retraction of the suprasupinatus (SSP), distance from the myotendinous junction to footprint (MuR) and tendon length (TL) of SSP were measured on the preoperative MRI (coronal T2-weighted images) according to Meyer. The intraoperative repairability was classified into 3 groups according to the modification of Yoo’s classification. Type1 was complete repair with complete coverage of the footprint. Type2 was complete repair with exposure of lateral one-half of the footprint. Type3 was incomplete repair. On postoperative MRI, repair integrity was determined as repaired or retear based on the Sugaya’s classification. MuR and TL were compared among 3 groups for repairability and between repaired and retear groups. To analyze the data quantitatively, cut off value (COV) and area under curve (AUC) determined by Receiver Operating Characteristic (ROC) curve for repairability and cuff integrity were calculated. We also investigated whether MuR/TL plus SSP muscle fatty infiltration (FI) (Goutallier) can increase the predictive value of intraoperative repairability and postoperative cuff integrity. Unpaired t-test, one-way ANOVA with Turkey –Kramer as post-hoc test and Chi square test were used for statistical analysis, and level of significance was set at p <.05.

Results

Sixty-nine tears were repaired completely (Type 1), type 2 was in 20 and type 3 was in 11 shoulders. Mean MuR in 3 types was significantly different each other (p<0.01), but TL was not different among types. COV of the MuR from type 1+2 to type 3 was 39.5mm (AUC: 0.88). Regarding repair integrity, retear was identified in 30 shoulders (30%). The MuR was significantly greater (p<0.01) and the TL was significantly smaller (p=0.04) in the retear group than those in repaired group. COV of the MUR and TL from repair to retear were 33.5 mm (AUC: 0.87) and 15.5mm (AUC: 0.71), respectively. When the MuR was greater than the COV and the FI was grade 3 or 4, 7 of 16 shoulders (43.8%) resulted in type 3 and retear rate was 42.1%. By contrast, when the MuR was shorter than the COV and the FI was grade 2 or less, only one shoulder of 63 shoulders (1.6%) resulted in type 3 repair and retear rate was 10.7% (p<0.001)

Conclusions

Compared with TL, MuR had more effect on intraoperative repairability and postoperative cuff integrity. The combination of MuR and Gouatallier grading appears to be a more powerful predictor for the intraoperative repairability and postoperative cuff integrity.