A Critical Review on Factors Affecting the User Adoption of Wearable and Soft Robotics.

In recent years, the advent of soft robotics has changed the landscape of wearable technologies. Soft robots are highly compliant and malleable, thus ensuring safe human-machine interactions. To date, a wide variety of actuation mechanisms have been studied and adopted into a multitude of soft wearables for use in clinical practice, such as assistive devices and rehabilitation modalities. Much research effort has been put into improving their technical performance and establishing the ideal indications for which rigid exoskeletons would play a limited role. However, despite having achieved many feats over the past decade, soft wearable technologies have not been extensively investigated from the perspective of user adoption. Most scholarly reviews of soft wearables have focused on the perspective of service providers such as developers, manufacturers, or clinicians, but few have scrutinized the factors affecting adoption and user experience. Hence, this would pose a good opportunity to gain insight into the current practice of soft robotics from a user's perspective. This review aims to provide a broad overview of the different types of soft wearables and identify the factors that hinder the adoption of soft robotics. In this paper, a systematic literature search using terms such as "soft", "robot", "wearable", and "exoskeleton" was conducted according to PRISMA guidelines to include peer-reviewed publications between 2012 and 2022. The soft robotics were classified according to their actuation mechanisms into motor-driven tendon cables, pneumatics, hydraulics, shape memory alloys, and polyvinyl chloride muscles, and their pros and cons were discussed. The identified factors affecting user adoption include design, availability of materials, durability, modeling and control, artificial intelligence augmentation, standardized evaluation criteria, public perception related to perceived utility, ease of use, and aesthetics. The critical areas for improvement and future research directions to increase adoption of soft wearables have also been highlighted.

A Learning-Based Approach to Sensorize Soft Robots.

Soft actuators and their sensors have always been separate entities with two distinct roles. The omnidirectional compliance of soft robots thus means that multiple sensors have to be used to sense different modalities in the respective planes of motion. With the recent emergence of self-sensing actuators, the two roles have gradually converged to simplify sensing requirements. Self-sensing typically involves embedding a conductive sensing element into the soft actuator and provides multiple state information along the continuum. However, most of these self-sensing actuators are fabricated through manual methods, which results in inconsistent sensing performance. Soft material compliance also imply that both actuator and sensor exhibit nonlinear behaviors during actuation, making sensing more complex. In this regard, machine learning has shown promise in characterizing the nonlinear behavior of soft sensors. Beyond characterization, we show that applying machine learning to soft actuators eliminates the need to implant a sensing element to achieve self-sensing. Fabrication is done using 3D printing, thus ensuring that sensing performance is consistent across the actuators. In addition, our proposed technique is able to estimate the bending curvature of a soft continuum actuator and the external forces applied to the tip of the actuator in real time. Our methodology is generalizable and aims to provide a novel way of multimodal sensing for soft robots across a variety of applications.

Comparing the Predictors of Functional Outcomes After Arthroscopic Rotator Cuff Repair Modified Frailty Index, Clinical Frailty Scale, and Charlson Comorbidity Index.

BACKGROUND: The incidence of rotator cuff tears increases with age, and operative management is usually required in patients with persistent symptoms. Although several studies have analyzed the effect of age and comorbidities on outcomes after rotator cuff repair, no study has specifically examined the consequence of frailty. PURPOSE: To determine the best frailty/comorbidity index for predicting functional outcomes after arthroscopic rotator cuff repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The authors conducted a retrospective cohort study of 340 consecutive patients who underwent unilateral arthroscopic rotator cuff repair at a tertiary hospital between April 2016 and April 2018. All patients had undergone arthroscopic double-row rotator cuff repair with subacromial decompression by a single fellowship-trained shoulder surgeon. Patient frailty was measured using the Modified Frailty Index (MFI), Clinical Frailty Scale (CFS), and Charlson Comorbidity Index (CCI), calculated through retrospective chart review based on case notes made just before surgery; patient age and sex were also noted preoperatively. Functional outcomes using the Oxford Shoulder Score (OSS), Constant Shoulder Score (CSS), University of California Los Angeles (UCLA) Shoulder Score, and visual analog scale for pain were measured preoperatively and at 3, 6, 12, and 24 months postoperatively. RESULTS: The MFI was a consistent significant predictor in all functional outcome scores up to 24 months postoperatively (P < .05), unlike the CFS and CCI. Sex was also a significant predictor of postoperative OSS, CSS, and UCLA Shoulder Score, with male sex being associated with better functional outcomes. Patients with higher MFI scores had slower functional improvement postoperatively, but they eventually attained functional outcome scores comparable with those of their counterparts with lower MFI scores at 24 months postoperatively. CONCLUSION: The MFI was found to be a better tool for predicting postoperative function than was the CFS or CCI in patients undergoing arthroscopic rotator cuff repair. The study findings suggest that a multidimensional assessment of frailty (including both functional status and comorbidities) is important in determining functional outcomes after arthroscopic rotator cuff repair.

Septuagenarians aged 75 years and older do benefit from arthroscopic rotator cuff repair: a propensity matched-pair analysis.

BACKGROUND: Numerous studies show that patients who failed conservative management, benefit from open, mini open and arthroscopic rotator cuff repair (ARCR). However, there is a paucity of literature addressing ARCR and outcomes in patients older than the age of 75 years. The purpose of our study was to compare the outcomes of ARCR in patients older than 75 years and younger than 75 years of age. METHODS: Between January 2010 and December 2016, 397 patients underwent unilateral ARCR; of which, 23 patients were 75 years of age and older. Outcome measures recorded include the Constant Shoulder Score (CSS), University of California, Los Angeles Shoulder Score (UCLASS), Oxford Shoulder Score (OSS), and visual analog scale (VAS) for pain assessment. RESULTS: There were no statistically significant differences in VAS, CSS, and UCLASS between the two groups at all time points of follow-up (all P > .05). At 2 years after surgery, the OSS was 2 ± 5 points better in the <75 group (P = .012). However, the improvement in OSS was comparable between both groups. The improvement in VAS, CSS, and UCLASS at 2 years after surgery compared with baseline was also similar between the two groups (all P < .05). CONCLUSIONS: The improvement in VAS, CSS, and UCLASS was similar in both groups of patients. We conclude that septuagenarians with symptomatic cuff tears, who have failed conservative management, experience significant improvement in pain, and function after surgery and should not be excluded from the benefits of ARCR.

Ultrasonic Percutaneous Tenotomy for Recalcitrant Lateral Elbow Tendinopathy: Clinical and Sonographic Results at 90 Months.

BACKGROUND: In a study from our institution, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon for recalcitrant lateral elbow tendinopathy showed excellent safety profiles, high tolerability, efficiency, sustained pain relief, functional improvement, and sonographic evidence of tissue healing in 20 patients at 3 years' follow-up. PURPOSE: To explore the long-term clinical and sonographic results of ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The same cohort of 20 patients was recalled after 7 years, and visual analog scale (VAS) for pain and Disabilities of the Arm, Shoulder and Hand (DASH) scores, need for secondary intervention, and overall satisfaction were assessed. They were also reassessed using ultrasound imaging of the brevis and the common extensor tendon to evaluate tendon hypervascularity, tendon thickness, and the progress or the recurrence of the hypoechoic scar tissue. RESULTS: We successfully scored 19 patients and performed ultrasound on 16 patients with a median follow-up of 90 months (range, 86-102 months). There were no adverse outcomes and satisfaction remained at 100% (6 patients, satisfied; 13 patients, very satisfied). No patient developed a recurrence of symptoms and signs of lateral elbow tendinopathy, and therefore no secondary intervention was required. The improvement from baseline and early term scores was sustained (P < .001 for all). At 90 months, there was a significant improvement in VAS scores and DASH-Compulsory scores compared with preprocedure scores and all follow-up times until 3 months. There was no difference in VAS scores and DASH-Compulsory scores at 90 months compared with 6 and 36 months. For DASH-Work scores, there was a significant improvement at 90 months compared with preprocedure scores, but there was no difference between DASH-Work scores at 90 months and scores at all other points of follow-up. At 90 months, hypervascularity remained resolved in 79% of patients, while all patients had reduced tendon swelling and sustained resolution or reduction of the hypoechoic lesion. CONCLUSION: At the long-term follow-up of 90 months, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon, previously shown to enhance recovery of lateral elbow tendinopathy, demonstrated good durability of pain relief and functional recovery that was previously achieved. This was accompanied by sustained sonographic tissue healing with no significant deterioration.

The UCLA Shoulder Score Is a Better Predictor of Treatment Success Than the Constant and Oxford Shoulder Scores After Arthroscopic Rotator Cuff Repair: A 2-Year Follow-Up Study.

PURPOSE: The aim of this study was to determine the correlation between functional outcome scores and treatment success after arthroscopic rotator cuff repair. METHODS: We conducted a retrospective cohort study of patients who underwent unilateral rotator cuff repair at a tertiary hospital between 2010 and 2015. University of California at Los Angeles Shoulder Score (UCLASS), Constant Shoulder Score (CSS), and Oxford Shoulder Score (OSS) were measured before and at 6, 12, and 24 months after surgery. Patients were divided into 2 groups at each follow-up: (1) those with successful treatment and (2) those with unsuccessful treatment. Treatment success was defined as simultaneous fulfilment of 3 criteria: clinically significant improvement in pain, expectations for surgery met, and patient satisfied with surgery. RESULTS: A total of 214 subjects met the inclusion criteria. UCLASS was a consistent significant predictor of treatment success at 6 months (odds ratio [OR] 1.192, P = .005, 95% confidence interval [CI] 1.054-1.348), 12 months (OR 1.274, P < .001, 95% CI 1.153-1.406), and 24 months (OR 1.266, P < .001, 95% CI 1.162-1.380). Lower preoperative CSS was significant in predicting treatment success at 6 months (OR 0.952, P = .001, 95% CI 0.926-0.979), while larger tear size was significant in predicting treatment success at 24 months (OR 1.773, P = .043, 95% CI 1.019-3.083). CONCLUSION: UCLASS is a better tool for predicting treatment success than CSS and OSS in patients undergoing arthroscopic rotator cuff repair, up to a minimum of 24 months' follow-up. A holistic assessment of shoulder function, taking into account both subjective and objective evaluation of function, as well as patient-reported satisfaction, is important in determining treatment success after arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: III, retrospective comparative study.

No Difference in Outcome Between Articular-Sided and Bursal-Sided Tears: Comparative Study With Minimum 2-Year Follow-Up of Arthroscopic Repairs in 104 Patients in a Single-Surgeon Series.

PURPOSE: To evaluate and compare the functional outcomes after arthroscopic repair of bursal-sided versus articular-sided partial-thickness rotator cuff tears. METHODS: We conducted a retrospective analysis of patients who had undergone arthroscopic tear completion and subsequent repair of symptomatic partial-thickness rotator cuff tears in a single institution from 2010 to 2015. Range of motion (ROM) (forward flexion and abduction), the pain score as measured on the Numeric Pain Rating Scale, and outcome scores (Constant-Murley score, University of California, Los Angeles shoulder score, and Oxford Shoulder Score) were calculated preoperatively and at 1 year and 2 years postoperatively. The delta difference was calculated for each outcome parameter at the respective follow-up points as the difference from the preoperative baseline score. RESULTS: A total of 104 patients were included. All tears involved the supraspinatus tendon and did not exceed 2 cm. Of the patients, 65 had an articular-sided tear (AST) whereas 39 had a bursal-sided tear (BST). The mean age of the patients was 53.4 years in the AST group and 55.8 years in the BST group. The AST and BST groups did not differ preoperatively in terms of age, sex, and the measured outcome parameters. Postoperatively, the patients in both groups achieved statistically significant improvement in pain relief and functional outcomes at 2 years. No statistically significant difference was observed between the 2 groups in terms of the delta-difference outcomes in ROM in forward flexion (P = .781) or abduction (P = .348), pain score (P = .187), Constant-Murley score (P = .186), University of California, Los Angeles shoulder score (P = .911), and Oxford Shoulder Score (P = .186) at 2 years. CONCLUSIONS: Partial-thickness rotator cuff tears treated with arthroscopic tear completion and subsequent repair achieved good outcomes in terms of ROM, functional outcomes, and pain relief at 2 years. There was no difference in outcomes regardless of whether the location of the tear was articular sided or bursal sided. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Dyslipidemia With Perioperative Statin Usage Is Not Associated With Poorer 24-Month Functional Outcomes After Arthroscopic Rotator Cuff Surgery.

BACKGROUND: Current literature suggests a higher rate of rotator cuff disease development in patients with dyslipidemia (DL). Moderate to high levels of DL are associated with higher rates of retear and revision surgery after arthroscopic rotator cuff repair. Statins protect against development of rotator cuff disease and mitigate the need for rotator cuff repair. PURPOSE: We aimed to investigate the influence of DL and statin use on postoperative functional outcomes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between 2010 and 2016, 266 patients underwent arthroscopic double-row rotator cuff repair for atraumatic full-thickness tears. Evaluation was conducted preoperatively and at 3, 6, 12, and 24 months postoperatively. Three functional outcome measures were used (Constant Shoulder Score [CSS], Oxford Shoulder Score [OXF], and University of California, Los Angeles, Shoulder Rating Scale [UCLASS]), as well as a visual analog scale (VAS) for pain. DL and non-DL were classified through screening of health and assessment of lipid levels within 6 months of surgery (triglycerides, total cholesterol, low-density lipoprotein, and high-density lipoprotein). Patients with DL were divided into statin users and nonusers. Types and dosages of statins were recorded, and intensity and equivalency charts were employed for standardization. Mann-Whitney U test and Pearson chi-square test were used for analysis. Generalized estimating equations and linear mixed models were used to examine the influence of DL and statin dosage, respectively on percentage change of postoperative outcome scores. RESULTS: Increased age was associated with a higher incidence of DL (P < .001), and 86% of the DL group was taking statins. The DL group also exhibited poorer scores preoperatively (CSS, P = .001; OXF, P = .032). No significant difference in scores was elicited between the DL and non-DL groups at 24 months. However, patients with DL experienced greater percentage improvement of CSS and OXF from preoperative baseline than did patients without DL (P = .008 and P = .034, respectively) at 24 months. There was no significant difference in 24-month functional outcomes between statin users and nonusers. No statistically significant change of CSS; OXF; UCLASS; or VAS was noted with increasing statin doses at 24 months. CONCLUSION: Patients with DL with perioperative statin usage did not have poorer 24-month functional outcomes after arthroscopic rotator cuff surgery compared with those in patients without DL.

A Review of the Gillquist Maneuver: Modifications for a Safer and Easily Reproducible Approach for Knee Transintercondylar Notch Posterior Compartment Arthroscopy.

The original Gillquist maneuver is done by passing the arthroscope through a portal in the patella tendon between the medial femoral condyle and posterior cruciate ligament to enter the posterior compartment. This is done blind and has been documented to result in broken cameras and damaged equipment. It is also necessary to do a notchplasty to aid the advancement of the camera in patients. In our paper, we have made modifications to allow the Gillquist maneuver to be done safely under direct visualization, with just the aid of a simple switching stick. Our technique starts with the arthroscope in the anteromedial portal. We insert a long, cannulated switching stick through the anterolateral portal and pass it between the medial femoral condyle and the posterior cruciate ligament. The switching stick, being tapered and narrow, is able to traverse the transcondylar notch with minimal trauma. Once the switching stick enters the posterior compartment, the camera and trocar are removed and the trocar sleeve is guided over the switching stick past the intercondylar notch gently. The switching stick is then replaced by the arthroscope, which is advanced through the trocar sleeve and into the posterior compartment.

Arthroscopic undersurface rotator cuff repair versus conventional arthroscopic double-row rotator cuff repair - Comparable results at 2-year follow-up.

AIM: The aim of our study is to compare the improvement in clinical outcomes after conventional arthroscopic double-row rotator cuff repair and arthroscopic undersurface rotator cuff repair. METHOD: A consecutive series of 120 patients who underwent arthroscopic rotator cuff repair was analysed. Sixty-one patients underwent conventional double-row rotator cuff repair and 59 patients underwent undersurface rotator cuff repair. Several clinical outcomes, including numerical pain rating scale (NPRS), constant shoulder score (CSS), Oxford shoulder score (OSS) and University of California Los Angeles shoulder score (UCLASS), were prospectively recorded by a trained healthcare professional preoperatively and at 3, 6, 12 and 24 months after surgery. RESULT: Comparing both groups, there were no differences in age, gender and preoperative NPRS, CSS, OSS and UCLASS. However, the tear size was 0.7 ± 0.2 (95% confidence interval (CI) 0.3-1.1) cm larger in the conventional group ( p = 0.002). There was no difference in the improvement of NPRS, CSS, OSS and UCLASS at all time points of follow-up, that is, at 3, 6, 12 and 24 months after surgery. The duration of operation was shorter by 35 ± 3 (95% CI 28-42) min in the undersurface group ( p < 0.001). CONCLUSION: Both arthroscopic undersurface rotator cuff repair and conventional arthroscopic double-row rotator cuff repair showed marked improvements in clinical scores when compared preoperatively, and there was no difference in improvements between both groups. Arthroscopic undersurface rotator cuff repair is a faster technique compared to the conventional arthroscopic double-row rotator cuff repair.

Pain Resolution After Hallux Valgus Surgery.

BACKGROUND: Although more than 1500 publications on hallux valgus can be found in the current literature, none of them have reported on the course of pain resolution after hallux valgus surgery. Thus, this study aimed to investigate pain resolution after hallux valgus surgery and to identify predictive factors associated with residual pain at 6 months after surgery. METHODS: We prospectively followed up 308 patients who underwent hallux valgus surgery at a tertiary hospital at 6 months and 2 years after surgery. Multivariate logistic regression analysis was performed to evaluate the risk factors associated with residual pain after surgery. RESULTS: Ninety-four patients (31%) had some degree of residual pain at 6 months after surgery. After excluding 4 patients who developed osteoarthritis of the first metatarsophalangeal joint over the next 18 months, 73 of the remaining 90 (81%) experienced improvement in visual analog scale (VAS) by the 2-years follow-up. Their median VAS improved from 4 (interquartile range [IQR] 3, 5) at 6 months to 0 (IQR 0, 3) at 2 years (P < .001). A higher preoperative VAS increased the risk of having persistent pain at 6 months after sugery (odds ratio [OR] 1.388, 95% confidence interval [CI] 1.092, 1.764, P = .007), whereas a higher preoperative Mental Component Score of SF-36 (MCS) reduced this risk (OR 0.952, 95% CI 0.919, 0.987, P = .007). CONCLUSIONS: As much as 31% of patients will have residual pain at 6 months after surgery. Preoperative VAS and MCS are predictors for residual pain. However, these patients will continue to improve over the next 18 months, with 71% of them being pain free at 2 years after surgery. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Drilling the near cortex with elongated figure-of-8 holes to reduce the stiffness of a locking compression plate construct.

PURPOSE: To compare the stiffness of locking compression plate (LCP) constructs with or without drilling the near cortex with elongated figure-of-8 holes. METHODS: 24 synthetic bones were sawn to create a 10-mm gap and were fixed with a 9-hole 4.5-mm narrow LCP. In 12 bones, the near cortex of the adjacent holes to the LCP holes was drilled to create elongated figure-of-8 holes before screw insertion. The stiffness of LCP constructs under axial loading or 4-point bending was assessed by (1) dynamic quasi-physiological testing for fatigue strength, (2) quasi-static testing for stiffness, and (3) testing for absolute strength to failure. RESULTS: None of the 24 constructs had subcatastrophic or catastrophic failure after 10 000 cycles of fatigue loading (p=1.000). The axial stiffness reduced by 16% from 613±62 to 517±44 N/mm (p=0.012) in the case group, whereas the bending stiffness was 16±1 Nm2 in both groups (p=1.000). The maximum axial load to catastrophic failure was 1596±84 N for the control group and 1627±48 N for the case group (p=0.486), whereas the maximum bending moment to catastrophic failure was 79±12 and 80±10 Nm, respectively (p=0.919). CONCLUSION: Drilling the near cortex with elongated figure-of-8 holes reduces the axial stiffness of the LCP construct, without compromising its bending stiffness or strength.