Abduction causes increased strain gradient compared to forward flexion: Evidence from a cadaver model of simultaneous strain study of the rotator cuff tendons.

BACKGROUND: Various strain studies of the supraspinatus have been done in isolation. Given that rotator cuff muscles function as a group, it may be physiologically representative to measure strain behaviour with the glenohumeral joint intact. Here, we explored a novel method in measuring simultaneous strain behaviour of the rotator cuff tendons and investigated the effect of full-thickness anterior tear of the supraspinatus on the infraspinatus and subscapularis tendons. METHODS: Nine cadaveric shoulders were evaluated on a customized rig. Using linear differential variable transducers to measure strain, each shoulder was subjected to up to 60° of elevation in the coronal, scapular, and sagittal planes. We also assessed 30° of external rotation and up to 60° of internal rotation of the humerus. Full-thickness anterior tear of the supraspinatus was then made before re-assessing strain patterns in the scapular plane. FINDINGS: Strain measurements of the intact tendons revealed a significant strain gradient between the articular and bursal sides of the supraspinatus during increasing degrees of elevation in the coronal and scapular planes. Full thickness anterior tear of the supraspinatus is localised to the tendon and does not affect the surrounding cuff musculature, with a potential shielding effect of the infraspinatus during early glenohumeral abduction. INTERPRETATION: Significant strain gradient exists between the articular and bursal sides of the supraspinatus during abduction but not during forward flexion in an intact glenohumeral joint. Rehabilitation exercises for anterior supraspinatus tears can be appropriately targeted on the remaining intact rotator cuff musculature.

Real-world utilization of PD-1/PD-L1 inhibitors with palliative radiotherapy in patients with metastatic non-small cell lung cancer.

BACKGROUND: Programmed cell death protein 1 (PD-1) blockade plus radiotherapy may be a promising strategy to improve the prognosis of patients with metastatic non-small cell lung cancer (NSCLC). However, the optimum combined scheme, treatment time of radiotherapy, and irradiated lesion have not been fully determined. METHODS: A total of 321 metastatic NSCLC patients treated with immunotherapy were identified. Among them, 107 patients received PD-1/PD-ligand 1 (PD-L1) inhibitors with radiotherapy, while the remaining cases did not receive radiotherapy. Data on overall survival (OS), progression-free survival (PFS), treatment response and adverse events were collected. Comparisons based on type of radiation, timing of radiotherapy and number of irradiated lesions were performed. RESULTS: The median OS in PD-1/PD-L1 inhibitors plus radiotherapy was longer than in nonradiotherapy (22.8 vs. 16.6 months, p = 0.022). The median PFS showed a similar trend in this study (9.4 vs. 6.2 months, p = 0.042). Moreover, the combined strategy demonstrated a superior disease control rate and abscopal control rate versus without radiotherapy (both p ≤ 0.001). Further multivariate analysis in the immunotherapy and radiotherapy groups revealed that age below 65 (p = 0.004), Eastern Cooperative Oncology Group performance scores of 0-1 (p = 0.001), oligometastasis (p = 0.006), concurrent combination (p = 0.002), and treated with SRT (p = 0.013) were associated with longer OS. There was a similar incidence of adverse events between the two groups (both p ≥ 0.05). CONCLUSIONS: The combination of PD-1/PD-L1 inhibitors plus palliative radiotherapy demonstrated favorable survival and good tolerability in metastatic NSCLC patients.