Rates of Return to Manual Labor After Arthroscopic Rotator Cuff Repair.

BACKGROUND: Rotator cuff tears represent a significant cause of shoulder pain and dysfunction in the United States. The development of these injuries is associated with older patient age and higher levels of physical activity; however, data regarding the rate of return to work after arthroscopic rotator cuff repair in patients older than 50 years of age who have physically strenuous jobs is inconclusive. PURPOSE/HYPOTHESIS: The purpose of this study was to report short term outcomes and return to work rates after arthroscopic rotator cuff repair in a cohort of patients aged 50 to 60 years working in manual labor jobs. It was hypothesized that arthroscopic rotator cuff repair would result in good functional outcomes for these patients and allow for return to work rates in excess of 80%. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Preoperative and final evaluations including the pain visual analog scale (VAS), the Single Assessment Numeric Evaluation (SANE), and the American Shoulder and Elbow Surgeons (ASES) Shoulder Score were collected. A total of 73 patients were screened for inclusion. Nineteen patients were outside of the inclusion age range, 2 underwent exclusionary concomitant procedures, and 4 patients were lost to follow up, leaving a total of 48 patients with a mean follow up of 34.02 months (range, 24-67 months) available for analysis. None of the patients were involved in a workers' compensation claim. Subgroup analysis was performed to determine if arm dominance or tear size affected surgical outcomes or return to work rates. RESULTS: After arthroscopic rotator cuff repair, 43 of 48 patients (89.6%) were able to return to manual labor positions. Tears were classified using the Southern California Orthopaedic Institute Classification at the time of repair as massive (C4) in 9 patients (18.75%), large (C3) in 13 patients (27.08%), medium (C2) in 21 patients (43.75%), and small (C1) in 5 patients (10.42%). At latest follow up, the mean VAS decreased from 8.0 ± 1.81 to 0.46 ± 1.20, the average SANE increased from 47.50 ± 18.59 to 91.88 ± 12.30, and the average ASES score improved from 39.58 ± 10.71 to 93.44 ± 11.97 (P < .0001). Outcomes did not differ between patients who underwent surgery on their dominant shoulder and those who underwent surgery on their nondominant shoulder. The overall postoperative complication rate was 8.33%. CONCLUSION: Arthroscopic rotator cuff repair portended favorable outcomes and high rates of return to work in this cohort of manual laborers, with 89.6% of patients able to return to work.

Bacteriophage T4-encoded Stp can be replaced as activator of anticodon nuclease by a normal host cell metabolite.

The bacterial tRNALys-specific anticodon nuclease is known as a phage T4 exclusion system. In the uninfected host cell anticodon nuclease is kept latent due to the association of its core protein PrrC with the DNA restriction-modification endonuclease EcoprrI. Stp, the T4-encoded peptide inhibitor of EcoprrI activates the latent enzyme. Previous in vitro work indicated that the activation by Stp is sensitive to DNase and requires added nucleotides. Biochemical and mutational data reported here suggest that Stp activates the latent holoenzyme when its EcoprrI component is tethered to a cognate DNA substrate. Moreover, the activation is driven by GTP hydrolysis, possibly mediated by the NTPase domain of PrrC. The data also reveal that Stp can be replaced as the activator of latent anticodon nuclease by certain pyrimidine nucleotides, the most potent of which is dTTP. The activation by dTTP likewise requires an EcoprrI DNA substrate and GTP hydrolysis but involves a different form of the latent holoenzyme/DNA complex. Moreover, whereas Stp relays its activating effect through EcoprrI, dTTP targets PrrC. The activation of the latent enzyme by a normal cell constituent hints that anticodon nuclease plays additional roles, other than warding off phage T4 infection.