The absence of a positive family history (PFH) in 10%-25% of patients poses a diagnostic challenge for autosomal dominant polycystic kidney disease (ADPKD). In the Toronto Genetic Epidemiology Study of Polycystic Kidney Disease, 210 affected probands underwent renal function testing, abdominal imaging, and comprehensive and mutation screening. From this cohort, we reviewed all patients with and without an apparent family history, examined their parental medical records, and performed renal imaging in all available parents of unknown disease status. Subsequent reclassification of 209 analyzed patients revealed 72.2% (151 of 209) with a PFH, 15.3% (32 of 209) with disease, 10.5% (22 of 209) with an indeterminate family history, and 1.9% (four of 209) with PFH in retrospect. Among the patients with cases, we found two families with germline mosaicism and one family with somatic mosaicism. Additionally, analysis of renal imaging revealed that 16.3% (34 of 209) of patients displayed atypical PKD, most of which followed one of three patterns: asymmetric or focal PKD with PFH and an identified or mutation (15 of 34), asymmetric and PKD with proven or suspected somatic mosaicism (seven of 34), or focal PKD without any identifiable or mutation (eight of 34). In conclusion, PKD without an apparent family history may be due to disease, missing parental medical records, germline or somatic mosaicism, or mild disease from hypomorphic and mutations. Furthermore, mutations of a newly identified gene for ADPKD, , and somatic mosaicism need to be considered in the mutation-negative patients with focal disease.

Background: It is undetermined which factors predict return to work after arthroscopic rotator cuff repair. Purpose: To identify which factors predicted return to work at any level and return to preinjury levels of work 6 months after arthroscopic rotator cuff repair. Study Design: Case-control study; Level of evidence, 3. Methods: Multiple logistic regression analysis of prospectively collected descriptive, preinjury, preoperative, and intraoperative data from 1502 consecutive primary arthroscopic rotator cuff repairs, performed by a single surgeon, was performed to identify independent predictors of return to work at 6 months postoperatively. Results: Six months after arthroscopic rotator cuff repair, 76% of patients had returned to work, and 40% had returned to preinjury levels of work. Return to work at 6 months was likely if patients were still working after their injuries but before surgery (Wald statistic [W] = 55, P < .0001), were stronger in internal rotation preoperatively (W = 8, P = .004), had full-thickness tears (W = 9, P = .002), and were female (W = 5, P = .030). Patients who continued working postinjury but presurgery were 1.6 times more likely to return to work at any level at 6 months compared to patients who were not working ( P < .0001). Patients who had a less strenuous preinjury level of work (W = 173, P < .0001), worked at a mild to moderate level post injury but presurgery, had greater preoperative behind-the-back lift-off strength (W = 8, P = .004), and had less preoperative passive external rotation range of motion (W = 5, P = .034) were more likely to return to preinjury levels of work at 6 months postoperatively. Specifically, patients who worked at a mild to moderate level postinjury but presurgery were 2.5 times more likely to return to work than patients who were not working, or who were working strenuously postinjury but presurgery ( p < 0.0001). Patients who nominated their preinjury level of work as “light” were 11 times more likely to return to preinjury levels of work at 6 months compared to those who nominated it as “strenuous” ( P < .0001). Conclusion: Six months after rotator cuff repair, patients who continued to work after injury but presurgery were the most likely to return to work at any level, and patients who had less strenuous preinjury levels of work were the most likely to return to their preinjury levels of work. Greater preoperative subscapularis strength independently predicted return to work at any level and to preinjury levels.

Objectives-How the material properties of the human supraspinatus tendon change following arthroscopic rotator cuff repair is undetermined. Shear wave elastography ultrasound is a relatively new, noninvasive measure of tissue stiffness. We aimed to evaluate any temporal changes in stiffness and/or thickness of supraspinatus tendons in humans following primary arthroscopic rotator cuff repair.Methods-Shear wave elastography was performed at three predetermined regions by a single sonographer at 1-, 6-, 12-, 24-, and 52 weeks postoperatively in 50 consecutive single-row inverted mattress primary arthroscopic rotator cuff repairs. One-way ANOVA with Tukey's correction and Spearman's correlation tests was performed.Results-Of 50 patients, two retore by 1-week and were excluded. Two patients retore at 6 weeks, two at 12 weeks, and one at 24 weeks. The mean tendon stiffness in 48 patients at the tendon footprint increased by 21% (1.32 m/s) at 6 months (P < .001), with the lateral tendon stiffening before the medial tendon. Tendon thickness decreased by 11% (0.6 mm) at 6 weeks (P = .008), then stabilized to 24 weeks. Tendons that were less elastographically stiff at 1 week were more likely to be thinner at 6-weeks (r = .38, P = .010).Conclusions-The data supports the hypothesis that rotator cuff tendons repaired using the single-row inverted-mattress technique take 6 weeks to heal to bone. Unlike in other tendons, there was no hypertrophic healing response. Prior to 6 weeks, the tendon may stretch/thin-out, particularly if its material properties, as assessed by shear wave elastography, are inferior. The material properties of the tendon improved at the tendon insertion site first, then medially out to 12 months post-repair.