Massive rotator cuff tears in patients younger than 65 years. What treatment options are available?

Management of massive rotator cuff tears is a therapeutic challenge in patients younger than 65 years, particularly if still working. According to our hypothesis, choice of the most appropriate treatment option mainly depends on the patient's functional status and on two predictive factors: height of the subacromial space and fatty muscle infiltration. This is a retrospective, multicenter study of a series of 296 patients younger than 65 years, including 176 males and 120 females with extensive or massive cuff tear. Patients had loss of elevation or external rotation or both in 162 cases. Four types of management of massive rotator cuff tear were performed in this study: anatomical watertight repairs, palliative treatments and partial repairs, watertight repairs using flaps or cuff prostheses and reverse shoulder prostheses. At follow-up, the Constant score (65.6+/-3.4) and active elevation (147.7 degrees +/-32 degrees) had significantly improved. Active external rotation with elbow at the side, and acromiohumeral interval (AHI) were unchanged. Work-related injuries, previous surgeries and complications were correlated with a poorer Constant score. At follow-up, the anatomical repair sub-group had a significantly better Constant score than the three other treatment groups but involved patients with unchanged AHI and a low degree of fatty infiltration of the infraspinatus muscle. The reverse shoulder prostheses sub-group showed better outcomes in terms of function benefits. The presence of a long biceps was correlated with the use of a palliative treatment. In the light of the results and literature, an approach to treatment is suggested related to the functional capacity of patients, the AHI and the degree of fatty infiltration of the infraspinatus and subscapularis muscles.

Three-level systems as amplifiers and attenuators: a thermodynamic analysis.

Thermodynamics of a three-level maser was studied in the pioneering work of Scovil-Schulz-DuBois [Phys. Rev. Lett. 2, 262 (1959)10.1103/PhysRevLett.2.262]. In this Letter we consider the same three-level model, but we give a full thermodynamic analysis based on Hamiltonian and dissipative Lindblad superoperators. The first law of thermodynamics is obtained using a recently developed alternative [Phys. Rev. A 74, 063823 (2006)10.1103/PhysRevA.74.063823] to Alicki's definitions for heat flux and power [J. Phys. A 12, L103 (1979)10.1088/0305-4470/12/5/007]. Using a novel variation on Spohn's entropy production function [J. Math. Phys. (N.Y.) 19, 1227 (1978)10.1063/1.523789], we obtain Carnot's efficiency inequality and the Scovil-Schulz-DuBois maser efficiency formula when the three-level system is operated as a heat engine (amplifier). Finally, we show that the three-level system has two other modes of operation--a refrigerator mode and a squanderer mode--both of which attenuate the electric field.

Transverse beam spin asymmetries in forward-angle elastic electron-proton scattering.

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2=0.15, 0.25 (GeV/c)2. The results are inconsistent with calculations solely using the elastic nucleon intermediate state and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A(n) provides a direct probe of the imaginary component of the 2gamma exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

Strange-quark contributions to parity-violating asymmetries in the forward g0 electron-proton scattering experiment.

We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < or =Q2 < or =1.0 GeV2. These asymmetries, arising from interference of the electromagnetic and neutral weak interactions, are sensitive to strange-quark contributions to the currents of the proton. The measurements were made at Jefferson Laboratory using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate nonzero, Q2 dependent, strange-quark contributions and provide new information beyond that obtained in previous experiments.

Prediction of rotator cuff repair results by magnetic resonance imaging.

Thirty chronic rotator cuff tears were repaired consecutively and evaluated prospectively using a precise anatomic description of the tear that included the rotator interval, the Constant functional score, and an assessment of the tendon state and the atrophy of the supraspinatus muscle by preoperative and postoperative magnetic resonance imaging. Early correlations (mean followup, 21.1 months) attempted to define predictive factors of the final outcome of the repair, physical factors indicative of final tendon state, and postoperative evolution of supraspinatus atrophy. Magnetic resonance imaging oblique sagittal views showed that supraspinatus atrophy correlated with the sagittal and coronal extent of the tear and represented a strong predictive factor of postoperative retearing. At followup, 15 (50%) cuffs were continuous and thick, seven (23%) were continuous but thin, and six (20%) were retorn. Two (7%) cuffs had been repaired only partly. In the group with a persistent tear, flexion strength and differential Constant score were correlated with the final tendon state with no excellent or good results, and with less than 4 kg of strength. Supraspinatus atrophy improved in 18 of the 22 postoperative continuous cuffs, but never decreased in persistent tears, although there was pain relief and functional gain.