Effect of Exercise Using an Exoskeletal Hip-Assist Robot on Physical Function and Walking Efficiency in Older Adults.

Robotic technology has developed rapidly in recent years, and several robotic devices have been applied to improve physical, sensory, intellectual, psychological, and social functioning in the elderly and people with disabilities. In this study, we investigated the effects of EX1-assisted exercise in various environments on physical function, muscle strength, and walking efficiency in older adults. We designated four experimental conditions and randomly assigned participants to one of four groups: A (overground walking without an EX1), B (overground walking using the resistance mode of EX1), C (stair ascent using the assistance mode of EX1), and Group D (inclined treadmill walking using the assistance mode of EX1). A total of 60 community-dwelling elderly persons participated in 10 exercise intervention sessions for 4 weeks, and all participants were assessed before and after the exercise intervention. Physical function was measured by the 10-meter walk test for self-selected velocity (10MWT-SSV), short physical performance battery (SPPB), Berg balance scale (BBS), timed up and go (TUG), functional reach test (FRT), geriatric depression scale-short form (GDS-SF), and muscle strength of trunk and lower extremity. Cardiopulmonary metabolic energy efficiency was measured using a portable telemetric gas analyzer system. A significant increase in the 10MWT-SSV and TUG test was observed in groups B, C, and D. A statistically significant improvement in the SPPB and FRT was seen only in group D, and GDS-SF scores decreased significantly after exercise with an EX1 in groups B and D. Trunk and lower limb muscle strength increased more in the groups that exercised with EX1 assistance than those without an EX1, particularly in group B. The net metabolic energy costs and energy expenditure measurement during walking significantly improved in exercise groups C and D. The findings in this study support the application of the EX1 to physical activity and exercise to improve age-related changes in physical function, muscle strength, and walking efficiency among older adults. In addition, personalized exercise programs using different modes and training environments with an EX1 can enhance physical performance and walking efficiency in the elderly.

Results and Factors Affecting Clinical Efficacy of Medial Patellofemoral Ligament Reconstruction Using a Gracilis Tendon Suture Technique.

Background: This study evaluated the outcomes of medial patellofemoral ligament (MPFL) reconstruction using a gracilis tendon suture technique for patients with patellar instability. Potential factors affecting clinical efficacy were also evaluated. Methods: This study included 22 patients diagnosed with patellar instability, who underwent MPFL reconstruction using a gracilis tendon. Their mean age was 21.5 years (range, 15-48 years), and the mean follow-up period was 26.8 months (range, 12-66 months). Clinical evaluation included the determination of Kujala, Lysholm, and Tegner scores. Radiographic evaluation included changes in congruence angle and arthritic changes in the patellofemoral joint. Additionally, patients were examined for any complications, including recurrent dislocation. Factors affecting clinical efficacy were also evaluated. Results: All clinical scores improved at final follow-up. The mean congruence angle improved from 23.6° before surgery to -6.5° at final follow-up. Two of 15 patients developed osteoarthritic changes in the patellofemoral joint. Dislocation recurred in 2 patients with type C trochlear dysplasia, which showed a statistically significant association with recurrent dislocation when compared to type A and B dysplasia (p = 0.026). Kujala scores were significantly lower among patients with abnormal patellar tilts (p = 0.038), and Lysholm scores were significantly lower among patients with femoral internal rotation deformity (p = 0.024). Conclusions: Satisfactory results were obtained after MPFL reconstruction using a gracilis tendon suture technique for patients with patellar instability. However, dislocation recurred in patients with type C trochlear dysplasia, and clinical efficacy was lower among patients with femoral internal rotation and patellar tilt.

Comparison of the Characteristics of Rotator Cuff Tissue in a Diabetic Rat Model.

This study evaluated the biomechanical and histologic characteristics of the rotator cuff tendon and muscle tissue with rat models with diabetes mellitus (DM) (group 1) and 30 male rats without DM (group 2). We conducted a time zero study without any additional procedures or external variables at 9 weeks after induction of the diabetic rat model. Thereafter, quantitative evaluation of advanced glycation end products (AGEs) was accomplished via enzyme-linked immunosorbent assay and immunohistochemistry (IHC). Fatty infiltration was investigated with Oil Red O staining, and the peroxisome proliferator activated receptor-gamma (PPAR-gamma) value was studied with IHC. Grossly, the supraspinatus tendons of the group 1 rats were more friable and discolored (yellowish) than those of group 2. In the biomechanical analysis, group 1 rats showed significantly inferior ultimate failure load (P=.001) and ultimate stress (P=.02). Group 1 was significantly inferior to group 2 in terms of total histologic scoring (P<.001). Mean AGE levels were significantly higher in group 1 (P<.001), as determined by IHC. In evaluating fatty infiltration, the degree of Oil Red O staining was significantly higher in group 1 (P<.001), but there was no significant difference in PPAR-gamma value between the 2 groups (P=.14). The intact rotator cuffs of rats with DM were associated with inferior biomechanics in association with AGE accumulation and increased fatty infiltration, as confirmed by histologic examination The hyperglycemic state caused by DM is associated with rotator cuff tendon degeneration. [Orthopedics. 2022;45(3):e154-e161.].

Comparison of Outcomes of Spinal Accessory to Suprascapular Nerve Transfer Versus Nerve Grafting for Neonatal Brachial Plexus Injury.

Neonatal brachial plexus injuries may cause critical limitations of upper extremity function. The optimal surgical approach to address neonatal brachial plexus injuries has not been defined. In this systematic review, we compare clinical results after spinal accessory to suprascapular nerve transfer and nerve graft techniques among patients with neonatal brachial plexus injury. [Orthopedics. 2022;45(1):7-12.].

Effect of a Porous Suture Containing Transforming Growth Factor Beta 1 on Healing After Rotator Cuff Repair in a Rat Model.

BACKGROUND: The healing failure rate after rotator cuff repair is considerably high. PURPOSE: To evaluate the effect of a porous suture containing transforming growth factor beta 1 (TGF-ß1) on the sustained release of TGF-ß1 and rotator cuff healing in a rat model. STUDY DESIGN: Controlled laboratory study. METHODS: A porous suture was developed, and its tensile strength was measured. TGF-ß1 was delivered using the porous suture, and a TGF-ß1 release test and human fibroblast proliferation assay were performed. For the animal experiment, 30 rats were randomly allocated into 3 groups (n = 10 each). A bilateral supraspinatus tendon tear was made in all the rats, and repair was performed. Group 1 received repair only; group 2, repair and a single injection of TGF-ß1; and group 3, repair using the porous suture containing TGF-ß1. Eight weeks after repair, biomechanical and histological analyses were performed. RESULTS: The porous suture was successfully developed with mechanical properties compatible with the conventional suture, and the sustained release of TGF-ß1 from the porous suture was confirmed. In addition, the cell proliferation assay confirmed the biological safety of the porous suture. In the animal experiment, group 3 biomechanically exhibited the largest cross-sectional area and the highest ultimate failure load and ultimate stress (all P < .05). Histological examination revealed that group 3 showed significantly better collagen fiber density and tendon-to-bone maturation than did groups 1 and 2 (all P < .05). CONCLUSION: The porous suture containing TGF-ß1 could sustainedly and safely release TGF-ß1, and its use during rotator cuff repair could improve rotator cuff healing, as assessed on the basis of the biomechanical and histological changes in the rat model in this study. Considering the effectiveness, safety, and convenience of the porous suture without extra effort in surgery, the findings of the present study will have a far-reaching effect on the treatment of rotator cuff tears. CLINICAL RELEVANCE: The porous suture containing TGF-ß1 might improve healing after rotator cuff repair.

The best options in superior capsular reconstruction.

Irreparable massive rotator cuff tears cause pain, loss of function, and a decrease in range of motion, which cause serious disturbances in daily life. Young patients, in particular, are active and have relatively high functional requirements, and their surgical options are limited. Superior capsular reconstruction (SCR) was first proposed for irreparable massive rotator cuff tears, good clinical results have been reported in short-term follow up. Since then, SCR has been used increasingly worldwide for irreparable massive rotator cuff tears, and various studies have been published on clinical outcomes, biomechanical outcomes, surgical techniques, and graft types. This article reviews the optimal graft and surgical options for improving clinical outcomes in SCR.

Effects of assistance timing on metabolic cost, assistance power, and gait parameters for a hip-type exoskeleton.

There are many important factors in developing an exoskeleton for assisting human locomotion. For example, the weight should be sufficiently light, the assist torque should be high enough to assist joint motion, and the assistance timing should be just right. Understanding how these design parameters affect overall performance of a complex human-machine system is critical for the development of these types of systems. The present study introduces an assistance timing controller that regulates assistance timing such that peak joint velocity and peak assistance power are offset by a reference value for our hip-type exoskeleton. This is followed by measuring the manner in which various assistance timing references affect an important metric for performance, namely metabolic cost. The results indicate that net metabolic cost exhibits a concave up pattern with the most reduction of 21%, when compared to walking without the exoskeleton, at 0% assistance timing reference. The study also examines assistance timing's effect on gait parameters; increase in assistance timing reference increases step length, decreases cadence, and increases walk ratio (i.e. step length/cadence ratio) during treadmill walking.