Subscapularis Repair in Reverse Total Shoulder Arthroplasty: Differences in Outcomes Based on Preoperative Quality of Subscapularis Tendon.

Purpose: This study examines the influence of preoperative fatty infiltration (FI) of the subscapularis tendon (SBS) on outcomes following reverse total shoulder arthroplasty (rTSA) with SBS repair. Methods: A cohort of 161 rTSA patients with SBS repair, followed for a mean of 45.3 months, was divided into three groups based on FI: Group A (intact upper and lower portions, n = 85), Group B (intact lower portions, n = 44), and Group C (fatty infiltrated in both portions, n = 32). The mean age was 74.5 years (range: 65-95). Results: Preoperative FI displayed significant disparity among the groups: Group A (1.18 ± 0.60), Group B (2.95 ± 0.56), and Group C (4.0 ± 0.00) (p < .001). Group A exhibited a more positive trend in activities of daily living, particularly in toileting ability (81% in Group A, 68% in Group B, and 72% in Group C), although without statistical significance (p = 0.220). Complication rates varied: Group A had seven acromial fractures (8%), three cases of instability (3%), and six instances of scapular notching (7%). Group B experienced four acromial fractures (9%) and four cases of scapular notching (9%), while Group C had only one case of scapular notching (3%) (p = 0.733). Conclusion: In cases characterized by favorable preoperative SBS quality, there was an elevation in functional internal rotation (IR) post-surgery, accompanied by an increased incidence of postoperative complications. Hence, careful consideration is advised when determining the necessity for SBS repair. Level of Evidence: Level III, retrospective comparative study.

Posterior Compression Test: a Provocative Test for Detecting Posterior Labral Tears.

Purpose: The purpose is to assess the diagnostic accuracy of a provocative test coined as the 'posterior compression test' (PCT) in those with the suspected posterior labral tear or lesion. Methods: A total of 515 'arthroscopic labral repairs' were identified between April 2013 and September 2020. Excluding those with concomitant shoulder pathologies, and only including those with pre-operative documentation of the PCT and/or the Jerk test, 191 patients were included. For the purposes of the analyses, the patients were divided into 'non-posterior' labral tear group which included the anterior labral tears and/or the superior labral anterior-to-posterior (SLAP) tears, versus 'any posterior' labral tear group which included the isolated posterior labral tears, the SLAP tears with posterior extension and the pan-labral tears. Results: When the PCT was performed for the isolated posterior labral tears, the sensitivity was 92.6% with the specificity of 86.5%. The positive predictive value and negative predictive value were 71.4-97%, respectively. The Jerk test's sensitivity was 77.8% but when the two tests were combined, the sensitivity increased up to 96.3%. The combined sensitivity with the Jerk test was still up to 94.6% with the AUC (area under curve) /ROC (receiver operator characteristic) at 0.855. Low 'false-positive' rate with the PCT was observed when the test was performed for the 'non-posterior' labral group, with the sensitivity of 13.5%. Conclusions: The posterior compression test correlated well with the arthroscopic diagnoses in a subset of patients with suspected posterior labral pathology, possibly by means of direct stimulation. Level of Evidence: III; Diagnostic Study.

Arthroscopic decompression of calcific tendinitis without cuff repair.

Aims: The aim of this study was to investigate the outcomes of arthroscopic decompression of calcific tendinitis performed without repairing the rotator cuff defect. Methods: A total of 99 patients who underwent treatment between December 2013 and August 2019 were retrospectively reviewed. Visual analogue scale (VAS) and American Shoulder and Elbow Surgeons (ASES) scores were reviewed pre- and postoperatively according to the location, size, physical characteristics, and radiological features of the calcific deposits. Additionally, the influence of any residual calcific deposits shown on postoperative radiographs was explored. The healing rate of the unrepaired cuff defect was determined by reviewing the 29 patients who had follow-up MRIs. Results: Statistically significant improvement from pre- to postoperation was seen in all VAS and ASES scores for each group, but no statistical differences were seen between the postoperative scores according to the differences in the features of the calcific deposits. When residual calcification was observed postoperatively, the mean ASES and VAS (rest) scores improved significantly to 95.0 (SD 5.6) and 0.0 (SD 0.0), respectively (p = 0.006 and p < 0.001), and did not differ from those who had the complete removal. Of 29 patients who had follow-up MRIs, six (20.7%) showed signs of an interstitial tear. This group's mean postoperative ASES and VAS (rest) scores improved to excellent levels of 96.0 (SD 3.7) and 0.0 (SD 0.0), respectively, and were similar to those of the 23 patients with normal MRI appearances. Conclusion: Arthroscopic removal of calcific deposits without repairing the rotator cuff defect resulted in significant improvement in function and pain level, regardless of the deposit's location, size, type, and whether or not complete excision was achieved. Despite leaving the defects unrepaired, in the limited number of patients with follow-up MRIs, 23 of 29 patients (79.3%) showed good healing, and the rest, who had persistent signs of interstitial defects on the MRIs, still had excellent outcomes. The removal of calcific deposits without repairing the cuff defects provided excellent outcomes.

Assembly and alignment method for optimized spatial resolution of off-axis three-mirror fore optics of hyperspectral imager.

A fore optics for the hyperspectral spectrometer is designed, manufactured, assembled, and aligned. The optics has a telecentric off-axis three-mirror configuration with a field of view wider than 14 degrees and an f-number as small as 2.3. The primary mirror (M1) and the secondary mirror (M2) are axially symmetric aspheric surfaces to minimize the sensitivity. The tertiary mirror (M3) is a decentered aspheric surface to minimize the coma and astigmatism aberration. The M2 also has a hole for the slit to maintain the optical performance while maximizing the telecentricity. To ensure the spatial resolution performance of the optical system, an alignment procedure is established to assemble and align the entrance slit of the spectrometer to the rear end of the fore optics. It has a great advantage to confirm and maintain the alignment integrity of the fore optics module throughout the alignment procedure. To perform the alignment procedure successfully, the precision movement control requirements are calculated and applied. As a result, the alignment goal of the RMS wave front error (WFE) to be smaller than 90 nm at all fields is achieved.

Design and construction of an Offner spectrometer based on geometrical analysis of ring fields.

A method to obtain an aberration-corrected Offner spectrometer without ray obstruction is proposed. A new, more efficient spectrometer optics design is suggested in order to increase its spectral resolution. The derivation of a new ring equation to eliminate ray obstruction is based on geometrical analysis of the ring fields for various numerical apertures. The analytical design applying this equation was demonstrated using the optical design software Code V in order to manufacture a spectrometer working in wavelengths of 900-1700 nm. The simulation results show that the new concept offers an analytical initial design taking the least time of calculation. The simulated spectrometer exhibited a modulation transfer function over 80% at Nyquist frequency, root-mean-square spot diameters under 8.6 µm, and a spectral resolution of 3.2 nm. The final design and its realization of a high resolution Offner spectrometer was demonstrated based on the simulation result. The equation and analytical design procedure shown here can be applied to most Offner systems regardless of the wavelength range.

Initial design method based on an iterative calculation of aberration and its application to an objective lens for imaging spectrometer.

An initial optical design method based on an iterative calculation of third-order aberration is presented to overcome the problems of the conventional method. The aberrations of each lens group in the optical system are calculated individually and iteratively under the constraint that aberrations of one group compensate for those of the other groups. The stabilities of initial design results have been confirmed and the iterative design method has been applied for the design of optical system with an external entrance pupil for imaging spectrometer. The designed lens corresponds to an objective lens with the aperture of F/1.5 and the focal length of 30 mm.

Zoom lens design for a novel imaging spectrometer that controls spatial and spectral resolution individually.

A novel imaging spectrometer can individually control spatial and spectral resolution by using zoom lenses as the foreoptics of the system and a focusing lens. By varying the focal length we can use the focusing lens to change the spatial and spectral dimensions; with the foreoptics, however, we can change only the spatial dimension. Therefore the spectral resolution and the spectral range are affected by the zoom ratio of the focusing lens, whereas the spatial resolution and the field of view are affected by the multiplication of the zoom ratios of the foreoptics and the focusing lens. By properly combining two zoom ratios, we can control the spectral resolution with a fixed spatial resolution or the spatial resolution with a fixed spectral resolution. For an imaging spectrometer with this novel zooming function, we used the lens module method and third-order aberration theory to design an initial four-group zoom system with an external entrance pupil for the focusing lens. Furthermore, using the optical design software CODE V, we obtained an optimized zoom lens with a focal-length range of 50 to 150 mm. Finally, the zoom system with its transmission grating in the Littrow configuration performs satisfactorily as the focusing lens of an imaging spectrometer in the wavelength range 450-900 nm.