Characteristics and outcomes of L-shaped and reverse L-shaped rotator cuff tears.

The aim of this study was to compare the characteristics and outcomes of L-shaped and reverse L-shaped rotator cuff tears.A total of 82 shoulders (81 patients) after arthroscopic rotator cuff repair were retrospectively enrolled. The mean age of the patients was 62 years (SD 6), 33 shoulders (40.2%) were in male patients, and 57 shoulders (69.5%) were the right shoulder. Of these, 36 shoulders had an L-shaped tear (group L) and 46 had a reverse L-shaped tear (group RL). Both groups were compared regarding characteristics, pre- and postoperative pain, and functional outcomes. Muscle status was assessed by preoperative MRI, and re-tear rates by postoperative ultrasonography or MRI.Patients in group RL were significantly older than in group L (p = 0.008), and group RL was significantly associated with female sex (odds ratio 2.5 (95% confidence interval 1.03 to 6.32); p = 0.041). Mean postoperative pain visual analogue scale (VAS) score was significantly greater (group L = 0.8 (SD 1.5), group RL = 1.7 (SD 2.2); p = 0.033) and mean postoperative American Shoulder and Elbow Surgeons (ASES) score was significantly lower in group RL than group L (group L = 91.4 (SD 13.1), group RL = 83.8 (SD 17.9); p = 0.028). However, postoperative mean VAS for pain and ASES score were not lower than the patient-acceptable symptom state scores. Mean retracted tear length was significantly larger in group L (group L = 24.6 mm (SD 6.5), group RL = 20.0 mm (SD 6.8); p = 0.003). Overall re-tear rate for 82 tears was 11.0% (nine shoulders), and re-tear rates in group L and RL were similar at 11.1% (four shoulders) and 10.9% (five shoulders), respectively (p = 1.000). No significant intergroup difference was found for fatty degeneration (FD) or muscle atrophy. Within group L, postoperative FD grades of supraspinatus and subscapularis worsened significantly (p = 0.034 and p = 0.008, respectively). Mean postoperative pain VAS (male = 1.2 (SD 1.8), female = 1.3 (SD 2.0)) and ASES scores (male = 88.7 (SD 15.5), female = 86.0 (SD 16.8)) were similar in male and female patients (p = 0.700 and p = 0.475, respectively). Regression analysis showed age was not a prognostic factor of postoperative pain VAS or ASES scores (p = 0.188 and p = 0.150, respectively).Older age and female sex were associated with reverse L-shaped tears. Although the postoperative functional outcomes of patients with reverse L-shaped tears were satisfactory, the clinical scores were poorer than those of patients with L-shaped tears. Surgeons should be aware of the differences in clinical outcome between L-shaped and reverse L-shaped rotator cuff tears. Cite this article: Bone Joint J 2022;104-B(3):394-400.