Influence of subscapularis tendon reattachment after reverse shoulder arthroplasty: clinical findings and ultrasonographic evaluation of the subscapularis at 89 months mean follow-up.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is commonly used to treat rotator cuff arthropathy. In the deltopectoral approach for RSA, the subscapularis tendon is (partly) detached. The clinical effects of subscapularis reattachment are still under debate. An observational study was performed to evaluate the clinical effects of subscapularis tendon reattachment on the mid- to long-term following RSA. METHODS: In this study, 40 patients for a total of 46 shoulders with a reverse shoulder prosthesis participated. Constant Murley Score (CMS), Oxford Shoulder Score (OSS), Range of Motion (ROM) and abduction and internal rotation strength were measured. The integrity of the subscapularis tendon at follow-up was assessed using ultrasound. Outcomes were compared between three groups: repair and intact at follow-up, repair and not intact, and no repair. RESULTS: Mean follow-up was 89 months with a minimum of three years. CMS, OSS, ROM and strength did not differ between groups. One-third of the initially reattached subscapularis tendons were still present at follow-up. No dislocations were reported. CONCLUSION: This study showed no clinical effects of subscapularis reattachment after reverse shoulder arthroplasty on the mid- to long-term.

Is there any influence of humeral component retroversion on range of motion and clinical outcome in reverse shoulder arthroplasty? A clinical study.

PURPOSE: Reverse shoulder arthroplasty becomes more widely used as treatment for patients with complex cuff arthropathy. Theoretically, a higher retroversion of the humeral component leads to an increase in external rotation ROM and a decrease in internal rotation ROM. There is no consensus in optimal retroversion orientation. We retrospectively describe the effect of retroversion of the humeral component. We hypothesize that 20° humeral retroversion improves postoperative ROM, strength or clinical outcome scores compared to neutral retroversion. METHODS: A retrospective clinical study is performed. An Aequalis reverse shoulder prosthesis was placed in 65 shoulders from 58 patients with a mean age of 73.8 years (95% CI 72.0-75.6). Between October 2006 and May 2012, the humeral component was placed in neutral retroversion in 36 shoulders (55%). From June 2012 to June 2014, it was placed in 20° retroversion in 29 shoulders (45%). After a mean follow-up of 36 months with a minimum of 12 months, patients were invited for a study visit. ROM, strength, Constant-Murley and Oxford Scores were measured. RESULTS: ROM, strength and Constant-Murley and Oxford Scores did not differ significantly between both groups. CONCLUSIONS: With the Aequalis prosthesis, no significant effect of 0° or 20° retroversion on external and internal rotation ROM, strength or functional outcome scores was found.

The influence of subscapularis tendon reattachment on range of motion in reversed shoulder arthroplasty: a clinical study.

PURPOSE: Reverse shoulder arthroplasty becomes more widely used as a treatment for patients with painful cuff arthropathy. As a part of the deltopectoral approach, the subscapularis tendon, if present, is (partly) detached. There is no consensus on repair of the tendon after placement of the prosthesis. We retrospectively describe the clinical effects of subscapularis tendon reattachment. Our hypothesis was that subscapularis repair has no clinical effects on range of motion and functional outcome scores. METHODS: A retrospective clinical study is performed. An Aequalis reverse shoulder prosthesis (Tornier, Montbonnot, France) was placed in 65 patients with a mean age of 73.8 years (range 47-90). In 40 patients (61.5 %), the quality of the tendon was initially insufficient for repair. The subscapularis was repaired in 25 patients (38.5 %). After a mean follow-up of 36 months with a minimum of 12 months, an ultrasound examination of the subscapularis was performed in patients with a repaired tendon. Range of motion, strength, Constant-Murley and Oxford scores were measured. RESULTS: On ultrasound examination, 10 (40 %) out of 25 repaired subscapularis tendons were still sufficient. Postoperatively, range of motion, strength, Constant-Murley and Oxford scores did not differ significantly between repair with present tendon, repair with absent tendon or no repair. CONCLUSION: In reverse shoulder arthroplasty, no significant differences on range of motion, functional outcome scores or strength were found between subscapularis repair or no repair, whether the tendon healed at follow-up or not.

An estimation of the size distribution of amalgam particles in dental treatment waste.

Regulations have been adopted in several countries of the European Union which prescribe that dental treatment waste water must be discharged via an amalgam separator device. Since the effectivity of the device strongly depends on the size of the amalgam waste particles, this size was evaluated in waste water samples from eight dental offices. Per sample, all solid particles were separated from the waste water by pressure filtration, then dried and divided into six fractions by being sieved over five sieves with decreasing mesh width. Of the particles in each fraction, the density was determined by picnometry, the mass by weighing, and the area and width by image analysis. For this analysis, width was defined as the dimension perpendicular to the length of the particles. By combining the density, area, and width determinations of all fractions, we obtained mass distributions per waste particle width of the samples. The proportional amalgam mass of the distributions was estimated with the measured density of the particle fractions and with a number of assumptions for the density of amalgam particles only and of other waste particles only. Each waste sample has its own characteristics with respect to the mass and density of the particle fractions. The size distribution of waste particles has a bimodal shape and consists of a distribution of small (width, 2 to 90 microns) and large particles (width, 160 to 5500 microns). For small particles with a width up to 60 microns, the influence of the assumptions on the estimation of the proportion amalgam of the waste mass distribution is minor when compared with the sampling error. By averaging the estimations over the samples, one can estimate the weight of amalgam particles with a width < 10 microns and < 50 microns, respectively, between 4 and 15% and between 15 and 30%. The smallest particles comprising 5% of the amalgam mass have an estimated width of up to 15 microns.