Individuals with mild-to-moderate hip osteoarthritis walk with lower hip joint contact forces despite higher levels of muscle co-contraction compared to healthy individuals.

OBJECTIVE: To compare hip joint contact forces (HJCF), hip muscle forces, and hip muscle co-contraction levels between individuals with mild-to-moderate hip osteoarthritis (OA) and healthy controls during walking. DESIGN: Eighteen participants with mild-to-moderate hip OA and 23 healthy controls walked at a self-selected speed while motion capture and electromyographic data were synchronously collected. HJCF were computed using a calibrated electromyography-informed neuromusculoskeletal model. Hip joint contact forces, muscle forces, and co-contraction indices for flexor/extensor and adductor/abductor muscle groups were compared between groups using independent sample t-tests (P < 0.05). RESULTS: There was no between-group difference in self-selected walking speed. On average, participants with hip OA walked with 11% lower first peak (mean difference 235 [95% confidence interval (CI) 57-413] N) and 22% lower second peak (mean difference 574 [95%CI 304-844] N) HJCF compared to controls. Hip muscle forces were also significantly lower in the hip OA compared to control group at first (mean difference 224 [95%CI 66-382] N) and second (mean difference 782 [95%CI 399-1164] N) peak HJCF. Participants with hip OA exhibited higher levels of hip muscle co-contraction in both flexor/extensor and adductor/abductor muscle groups. Consistent with existing literature, hip joint angles (extension, adduction) and external moments (flexion, extension, adduction) were lower in hip OA compared to controls. CONCLUSION: Lower HJCF were detected in mild-to-moderate hip OA, primarily due to lower hip muscle force production, and despite higher levels of hip muscle co-contraction. Findings suggest that lower loading of the hip joint during walking is a feature of mild-to-moderate hip OA, which could have implications for the pathogenesis of hip OA and/or disease progression.

Long-term outcomes of dual innervation in functional muscle transfers for facial palsy.

BACKGROUND: This study describes a different approach with a 2-stage facial reanimation in patients with long-standing unilateral facial paralysis using free gracilis muscle transfer, innervated by both cross-facial nerve graft and masseteric nerve. The authors present their rationale, surgical technique, and long-term outcomes. METHODS: Between August 2012 and March 2016, 11 patients (6 female and 5 male patients) underwent a 2-staged dually innervated gracilis muscle transfer. Patients were evaluated with physical examination and needle electromyography. A standardized assessment of preoperative and postoperative photographs and videos was performed using Terzis' smile functional grading system at 48 months following surgery and the Emotrics software to assess improvement in symmetry over a 36-month postoperative period. RESULTS: Voluntary contraction of the gracilis muscle was observed in all patients at a mean of 4 months and 4 days following muscle transfer. A spontaneous smile produced without teeth clenching was developed in all patients by 18 months postoperatively. Six patients achieved excellent and 5 good results. The difference between the averaged pre- and postoperative scores was statistically significant. With Emotrics, there were significant improvements in the smile angle, upper lip elevation, commissural excursion, and commissural height, with continuous improvement over 36 months. The postoperative electromyography (EMG) confirmed dual innervation of the gracilis muscle by the facial and masseteric donor motor neural sources. We present our results at minimum 48 months postoperatively. CONCLUSIONS: Dual innervated two-stage gracilis transfer is an effective method for reanimation in long-standing unilateral facial paralysis, providing both rapid reinnervation of the transferred muscle, together with a powerful, synchronous smile.

Functional Effects of Single Semitendinosus Tendon Harvesting in Anatomic Anterior Cruciate Ligament Reconstruction: Comparison of Single versus Dual Hamstring Harvesting.

BACKGROUND: This study aimed to determine the effects of single semitendinosus tendon (ST) harvesting for anterior cruciate ligament (ACL) reconstruction by comparing outcomes of single ST and semitendinosus-gracilis tendon (ST-G) harvesting. METHODS: ACL reconstruction with ST-G harvesting (D group, n = 60) or single ST harvesting (S group, n = 60) were included according to inclusion criteria. Subjective assessments included subjective International Knee Documentation Committee score, Lysholm score, and Tegner activity scale score. Objective assessments included isokinetic strength and functional tests. These tests were completed at 36 months of follow-up. Magnetic resonance imaging (MRI) and second-look arthroscopy findings were evaluated. In the S group, regeneration properties were assessed by serial ultrasonography (US). RESULTS: The S group showed significantly less deep flexor strength deficit than the D group (p < 0.001). Deep flexor power deficits showed significant correlation with the shift of musculotendinous junction of the ST. There was significant difference in the cocontraction test between the groups (p = 0.012), and the S group tended to show better results in other functional tests at the last follow-up. There were no significant differences in graft tension and synovial coverage on second-look arthroscopy between the groups. In the S group, the regeneration rates assessed by US at the joint line and distal insertion were 81.7% and 80%, respectively at 6 months of follow-up. CONCLUSIONS: The S group showed significantly less deficit in deep flexor strength and tended to show better clinical results at the last follow-up than the D group. In the S group, more than 80% showed good regeneration at the 6-month follow-up. Hence, single ST harvesting is effective in minimizing flexor weakness and functional deficits and shows great potential for regeneration.

Intraoperative experiments combined with gait analyses indicate that active state rather than passive dominates the spastic gracilis muscle's joint movement limiting effect in cerebral palsy.

BACKGROUND: In cerebral palsy, spastic muscle's passive forces are considered to be high but have not been assessed directly. Although activated spastic muscle's force-joint angle relations were studied, this was independent of gait relevant joint positions. The aim was to test the following hypotheses intraoperatively: (i) spastic gracilis passive forces are high even in flexed knee positions, (ii) its active state forces attain high amplitudes within the gait relevant knee angle range, and (iii) increase with added activations of other muscles. METHODS: Isometric forces (seven children with cerebral palsy, gross motor function classification score = II) were measured during surgery from knee flexion to full extension, at hip angles of 45° and 20° and in four conditions: (I) passive state, after gracilis was stimulated (II) alone, (III) simultaneously with its synergists, and (IV) also with an antagonist. FINDINGS: Directly measured peak passive force of spastic gracilis was only a certain fraction of the peak active state forces (maximally 26%) measured in condition II. Conditions III and IV caused gracilis forces to increase (for hip angle = 45°, by 32.8% and 71.9%, and for hip angle = 20°, by 24.5% and 45.1%, respectively). Gait analyses indicated that intraoperative data for knee angles 61-17° and 33-0° (for hip angles 45° and 20°, respectively) are particularly relevant, where active state force approximates its peak values. INTERPRETATION: Active state muscular mechanics, rather than passive, of spastic gracilis present a capacity to limit joint movement. The findings can be highly relevant for diagnosis and orthopaedic surgery in individuals with cerebral palsy.

Two Cases of Duchenne Muscular Dystrophy That Showed Different Reactions to Nerve Stimulation During Peripheral Nerve Block: A Case Report.

In recent years, the technique of combined ultrasound and electrical stimulation-guided nerve block has been recommended. We present 2 patients with Duchenne muscular dystrophy who exhibited different muscle responses to nerve stimulation during the performance of peripheral nerve blocks for surgeries. Whereas a 2-year-old boy without severe disability showed the expected muscle contraction to electrical nerve stimulation, a 14-year-old boy with severe disability showed no muscle response. Our experience suggests that muscle responses to electrical nerve stimulation will vary with the stage of Duchenne muscular dystrophy.

Functioning free gracilis transfer to reconstruct elbow flexion and quality of life in global brachial plexus injured patients.

In the study, the functional recovery and relative comprehensive quality of life of cases of global brachial plexus treated with free functioning muscle transfers were investigated. Patients who received functioning gracilis muscle transfer between August 1999 and October 2014 to reconstruct elbow flexion, wrist and fingers extension were recruited. The mean age of the patients was 26.36 (range, 16-42) years. The mean period of time from gracilis transfer to the last follow-up was 54.5 months (range, 12-185 months). Muscle power, active range of motion of the elbow flexion, wrist extension, and total active fingers extension were recorded. SDS, SAS and DASH questionnaires were given to estimate patients' quality of life. 35.71% reported good elbow flexion and 50.00% reported excellent elbow flexion. The average ROM of the elbow flexion was 106.5° (range, 0-142°) and was 17.00° (range, 0-72°) for wrist extension. The average DASH score was 51.14 (range, 17.5-90.8). The prevalence of anxiety and depression were 42.86% and 45.24%. Thrombosis and bowstringing were the most common short and long-term complications. Based on these findings, free gracilis transfer using accessory nerve as donor nerve is a satisfactory treatment to reconstruct the elbow flexion and wrist extension in global-brachial-plexus-injured patients.