Ribonuclease-A (RNase-A) encapsulated PbS quantum dots (RNase-A@PbS Qdots) which emit in the second near-infrared biological window (NIR-II, ca. 1000–1400 nm) are rapidly synthesized under microwave heating. Photoluminescence (PL) spectra of the Qdots can be tuned across the entire NIR-II range by simply controlling synthesis temperature. The size and morphology of the Qdots are examined by transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic light scattering (DLS). Quantum yield (Φ_f) measurement confirms that the prepared Qdots are one of the brightest water-soluble NIR-II emitters for in vivo imaging. Their high Φ_f (∼17.3%) and peak emission at ∼1300 nm ensure deep optical penetration to muscle tissues (up to 1.5 cm) and excellent imaging contrast at an extremely low threshold dose of ∼5.2 pmol (∼1 μg) per mouse. Importantly, this protein coated Qdot displays no signs of toxicity toward model neuron, normal, and cancer cells in vitro. In addition, the animal’s metabolism results in thorough elimination of intravenously injected Qdots from the body within several days via the reticuloendothelial system (RES), which minimizes potential long-term toxicity in vivo from possible release of lead content. With a combination of attractive properties of high brightness, robust photostability, and excellent biocompatibility, this new NIR-II emitting Qdot is highly promising in accurate disease screening and diagnostic applications.

Currently, there is an ongoing debate regarding the optimal graft choice between autograft and allograft tendons in reconstruction of the anterior cruciate ligament (ACL). It has been reported that allograft tendons have a slower onset and rate of revascularization compared with autograft tendons. Allograft tendons might have inferior graft maturity compared with autograft tendons in ACL reconstruction at 2 years postoperatively. Cohort study; Level of evidence, 3. A total of 52 participants with ACL reconstruction were recruited in this study, including 30 using allograft tendons and 22 using autograft tendons. All of them had unilateral ACL reconstruction and were followed up using 3.0-T magnetic resonance imaging (MRI) at least 2 years postoperatively. Clinical examination was performed on the same day when the MRI examination was performed, including subjective functional examinations (International Knee Documentation Committee [IKDC] and Tegner Lysholm Knee Scoring Scale [TLKS]) and physical examinations (anterior drawer test and Lachman test). Four measurements based on MRI were focused on graft orientation (including tibial tunnel position and graft angles), the edematous condition of the graft, intra-articular graft width at different sites, and signal intensity of the ACL graft using the signal/noise quotient (SNQ) from a region of interest analysis. Differences in each measurement were compared between the allograft group and the autograft group. All the participants returned to normal sports activities at the follow-up time point, as all of them acquired full functional strength and stability. There was no significant difference between the autograft and the allograft group with respect to IKDC or TLKS score. The knees in both of the groups were confirmed stable by physical examination before MRI. On MRI measurements, the allograft group displayed no significant difference in graft orientation compared with the autograft group (P > .05). Moreover, there was also no significant difference between allograft group and autograft group in graft width of the distal site (P > .05), middle site (P > .05), and proximal site (P > .05). However, the mean SNQ value of the allograft group was significantly higher than that of the autograft group in the distal site (6.54 ± 6.58 vs 2.98 ± 5.48; P = .0173), the middle site (7.21 ± 6.31 vs 3.56 ± 4.62; P = .0149), and the proximal site (6.61 ± 8.08 vs 2.45 ± 8.12; P = .0018). The allograft group had a significantly higher SNQ value compared with the autograft group in this study, indicating that allograft tendons might have inferior graft maturity than autograft tendons in ACL reconstruction at 2 years postoperatively.

The optimal graft choice of anterior cruciate ligament (ACL) reconstruction remains controversial. To compare the outcomes, especially the long-term cumulative failure rate, of ACL reconstruction using either synthetics with remnant preservation or hamstring autografts (4-strand semitendinosus and gracilis tendons). Cohort study; Level of evidence, 2. A total of 133 patients who underwent ACL reconstruction (synthetics: n = 43; hamstring autografts: n = 90) between July 2004 and December 2007 were included. Questionnaires (Tegner activity scale, Lysholm knee scale, and International Knee Documentation Committee [IKDC] subjective form) were completed preoperatively and at 6 months, 1 year, 5 years, and 10 years postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was additionally applied at 10 years’ follow-up. The physical examination was based on the 2000 IKDC form. The manual maximum side-to-side difference (KT-1000 arthrometer), single-hop test, thigh muscle atrophy, and joint degeneration (Kellgren and Lawrence classification) were evaluated. The Kaplan-Meier curve and log-rank test (Mantel-Cox, 95% CI) were used to compare graft survivorship. Ten years postoperatively, 111 patients were available, with 38 (88.4%) patients (mean age, 27.6 ± 9.3 years; 28 men) with synthetics and 73 (81.1%) patients (mean age, 28.6 ± 8.8 years; 64 men) with hamstring autografts. Among them, 104 patients (synthetics: n = 35 [81.4%]; hamstring autografts: n = 69 [76.7%]) completed subjective evaluations, and 89 patients (synthetics: n = 30 [69.8%]; hamstring autografts: n = 59 [65.6%]) completed objective evaluations. For hamstring autografts and synthetics, the cumulative failure rates were 8.2% and 7.9%, respectively, and the log-rank test demonstrated no significant difference between the 2 Kaplan-Meier survival curves (P = .910). At 6 months postoperatively, for hamstring autografts and synthetics, the mean Lysholm score was 83.0 ± 7.8 and 88.1 ± 7.5, respectively (P < .001); the mean IKDC score was 83.8 ± 7.8 and 86.9 ± 4.5, respectively (P = .036); and the mean Tegner score was 3.7 ± 1.1 and 5.0 ± 1.5, respectively (P < .001). At 1 year postoperatively, the mean Tegner score was 5.5 ± 1.9 and 6.5 ± 2.0, respectively (P = .011). No statistically significant difference was observed on other subjective evaluation findings, physical examination findings (overall IKDC grade A: 45.8% of hamstring autografts, 50.0% of synthetics), side-to-side difference (1.5 ± 1.5 mm for synthetics, 2.4 ± 2.1 mm for hamstring autografts), single-hop test findings (grade A: 84.7% of hamstring autografts, 93.3% of synthetics), grade A/B thigh muscle atrophy (88.1% of hamstring autografts, 93.3% of synthetics), ipsilateral radiographic osteoarthritis (55.9% of hamstring autografts, 50.0% of synthetics), and graft survivorship. In this prospective cohort study, primary ACL reconstruction using either synthetics with remnant preservation or hamstring autografts showed satisfactory outcomes, especially the long-term cumulative failure rate, at 10 years postoperatively. Patient-reported outcomes suggested that symptom relief and restoration of function might occur earlier in those with synthetics.

The critical shoulder angle (CSA) is the angle created between the superior and inferior bone margins of the glenoid and the most lateral border of the acromion. A few studies recently investigated the relation between CSA and functional outcomes after rotator cuff repair. However, there is a lack of research investigating the effect of CSA on postoperative tendon integrity after rotator cuff repair. To assess the effects of the CSA on postoperative tendon integrity after rotator cuff repair. Cohort study; Level of evidence, 3. All patients who underwent rotator cuff repair for full-thickness supraspinatus tears by 1 senior surgeon between January 2010 and January 2014 were included in this study. All patients had standardized anteroposterior shoulder radiographs the day before surgery. CSA and acromial index (AI) were measured. AI was derived by measuring the distance from the glenoid plane to the lateral border of the acromion and dividing it by the distance from the glenoid plane to the lateral aspect of the humeral head. Functional scores—including American Shoulder and Elbow Surgeons shoulder evaluation form, modified University of California at Los Angeles score, Constant-Murley score, and visual analog scale for pain—were used to evaluate shoulder function at a minimum follow-up of 2 years. Meanwhile, magnetic resonance imaging examinations were performed to evaluate rotator cuff integrity according to the Sugaya method and the signal/noise quotient (SNQ) of the rotator cuff tendon. A total of 90 patients were included in this study: 42 patients with a single-row repair and 48 with a double-row repair. There was a significant positive correlation between CSA or AI and tendon SNQ. On the basis of CSA, the patients were divided into 2 groups: large CSA (>38°) and control (CSA ≤38°). At final follow-up, the large CSA group and the control CSA group demonstrated no significant differences in American Shoulder and Elbow Surgeons, University of California at Los Angeles, Constant, and visual analog scale scores. Postoperative magnetic resonance imaging revealed that the large CSA group had 9 cases of retear, with a significantly higher retear rate than the control group (15% vs 0%, P = .03). Furthermore, the tendon SNQ of the large CSA group was significantly greater than that of the control group. CSA did not appear to influence postoperative functional outcomes, while those in the large CSA group had poor tendon integrity after rotator cuff repair. These findings indicate that a large CSA is associated with an increased risk of rotator cuff tendon retear after repair.