Hamstring Muscle-Tendon Geometric Adaptations to Resistance Training Using the Hip Extension and Nordic Hamstring Exercises.

Targeted resistance training stimulates hamstring muscle hypertrophy, but its effect on tendon-aponeurosis geometry is unknown. This study examined changes in hamstring muscle, free tendon, and aponeurosis geometry following a 10 week Nordic or hip extension exercise intervention. Thirty recreationally active males were randomly allocated (n = 10 per group) to a Nordic, hip extension, or control group. Magnetic resonance imaging of both thighs was acquired pre- and post-intervention. Changes in free tendon and aponeurosis volume for each hamstring muscle, biceps femoris long head (BFlh) aponeurosis interface area and muscle volume-to-interface area ratio were compared between groups. Regional changes in muscle CSA were examined via statistical parametric mapping. The change in semimembranosus free tendon volume was greater for the Nordic than control group (mean difference = 0.06 cm3, 95% CI = 0.02-0.11 cm3). No significant between-group differences existed for other hamstring free tendons or aponeuroses. There were no between-group differences in change in BFlh interface area. Change in BFlh muscle volume-to-interface area ratio was greater in the hip extension than Nordic (mean difference = 0.10, 95% CI = 0.007-0.19, p = 0.03) and control (mean difference = 0.12, 95% CI = 0.03-0.22, p = 0.009) groups. Change in muscle CSA following training was greatest in the mid-portion of semitendinosus for both intervention groups, and the mid-portion of BFlh for the hip extension group. There was limited evidence for tendon-aponeurosis hypertrophy after 10 weeks of training with the Nordic or hip extension exercises. For the BFlh, neither intervention altered the interface area although hip extension training stimulated an increase in the muscle volume-to-interface area ratio, which may have implications for localized tissue strains. Alternative muscle-tendon loading strategies appear necessary to stimulate hamstring tendon adaptations.

A Surgical Approach to a Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament Injury without Dividing the Adductor Aponeurosis.

An injury to the ulnar collateral ligament (UCL) of the metacarpophalangeal joint (MCPJ) of the thumb is a common injury, widely referred to as a skier's thumb. The rupture usually occurs at the distal insertion. In the classical technique, the adductor aponeurosis is divided to access the torn UCL and the MCPJ and repaired after ligament repair/reinsertion. We describe a surgical approach to the UCL that does not require division of the adductor aponeurosis. Level of Evidence: Level V (Therapeutic).

Biochemical and Histological Differences between Longitudinal and Vertical Fibres of Dupuytren's Palmar Aponeurosis and Innovative Clinical Implications.

Dupuytren's disease, a chronic and progressive fibroproliferative lesion of the hand, which affects the palmar fascia, has a recurrence rate after selective aponeurotomy of 20-40% at 5 years. This study focused, for the first time, on the microanatomical and histopathological characteristics of the longitudinal and vertical fibres (usually spared during surgery) in the aponeurosis with Dupuytren's disease, in different stages of the Tubiana's classification. Twelve human samples were collected and analysed by immunostaining, Total Collagen Assay, ELISA Immunoassay, and immunoblotting for the Von Willebrand factor, α-Sma, D2-40, CD-68, Total Collagen, Collagen-I and III, IL1ß, TNF-α to analyse the blood and lymphatic vascularization, the amount and distribution of collagen, and the inflammation. The results show a progressive increase in the arterial vascularization in the vertical fibres (from 8.8/mm2 in the early stage to 21.4/mm2 in stage 3/4), and a parallel progressive decrease in the lymphatic drainage (from 6.2/mm2 to 2.8/mm2), correlated with a local inflammatory context (increase in IL-1ß and TNF-α until the stage 2) in both the longitudinal and vertical fibres. The acute inflammation after stage 2 decreased, in favour of a fibrotic action, with the clear synthesis of new collagen (up to ~83 µg/mg), especially Collagen-I. These results clearly demonstrate the involvement of the septa of Legueu and Juvara in the disease pathology and the modifications with the disease's progression. A greater understanding of the pathology becomes fundamental for staging and the adequate therapeutic timing, to obtain the best morpho-functional result and the lowest risk of complications.

Reconstruction of the extensor tendon on the dorsal pedis with a chimeric skin-aponeurosis flap from the groin region.

BACKGROUND: Complex defects involving the extensor tendon on the dorsal pedis have been reconstructed using multiple procedures. Skin coverage and tendon transfers have also been performed. This study aimed to present our experience using a chimeric skin-aponeurosis flap for one-stage reconstruction of composite soft-tissue defects on the dorsal pedis. METHODS: Between May 2017 and September 2020, 12 patients with these defects received total treatment using a chimeric groin flap. Based on the superficial circumflex iliac vessels, the skin paddle resurfaced the cutaneous defect, and the vascularised external oblique aponeurosis was rolled to form a tendon-like structure to simultaneously replace the absent segment of the extensor tendons. A suitable "Y" bifurcation was dissected to enlarge the vessel diameter. Single-stage reconstruction was performed using a set of vascular anastomoses at the recipient site. RESULTS: Flap survival was achieved without significant complications. The hammertoe deformity was completely removed. The average dimension of the skin paddle was 8.0 × 13.0 cm (range, 6.5 × 11.0-10.0 × 14.0 cm), and the mean size of the aponeurosis was 8.0 × 4.0 cm (range, 6.0 × 3.0-10.0 × 5.0 cm). At the last follow-up visit, no morbidity was observed at the donor site. Natural shapes and walking functions were successfully achieved with a protective sensation. CONCLUSION: The chimeric groin flap with sheets of external oblique aponeurosis is a great candidate for one-stage reconstruction of composite soft tissue loss on the dorsal pedis. This approach provides cosmetic coverage, allowing faster wound healing and reduced tendon adhesions.

Long-term results of the Malingue technique in the surgical treatment of Dupuytren's disease.

OBJECTIVES: The choice of surgical technique for aponeurectomy in Dupuytren's disease is controversial due to varying outcomes and complication rates. The Malingue plasty has shown mathematical and mechanical advantages, but long-term efficacy and results compared to other techniques have never been reported. This study aimed to evaluate the long-term functional, esthetic and recurrence outcomes of Malingue plasty in Dupuytren's disease. MATERIAL AND METHODS: The study included patients who underwent aponeurectomy with Malingue plasty performed by a highly experienced surgeon between January 2014 and December 2016, with a minimum follow-up of 5 years. Preoperative records were analyzed. At follow-up, extension lag was analyzed in each joint (metacarpophalangeal, proximal interphalangeal and distal interphalangeal) in each operated finger, as well as signs of recurrence or extension of the disease. Function and esthetics were assessed using the QuickDASH (Disabilities of the Arm, Shoulder and Hand) questionnaire and the Michigan Hand Outcomes Questionnaire. RESULTS: Out of 107 eligible patients, 55 were included in the study after exclusions and loss to follow-up. Three patients required revision surgery for recurrence during follow-up. All preoperative deformities of the proximal interphalangeal and metacarpophalangeal joints were corrected postoperatively, and no intraoperative or postoperative complications occurred. Mean extension deficit at follow-up was 18.1 °. Only the little finger showed significant loss of correction (p = 0.02). Mean QuickDASH score was 13.2 and the overall Michigan Hand Outcomes Questionnaire score was 91.8%. Recurrence affected 50% of patients according to the Leclercq criteria and 27.5% according to the Felici criteria. CONCLUSION: Although Malingue plasty did not improve the recurrence rate in Dupuytren's disease compared with other techniques, its advantages in terms of functional improvement and complications make it an interesting surgical option.

Hamstrings Hypertrophy Is Specific to the Training Exercise: Nordic Hamstring versus Lengthened State Eccentric Training.

INTRODUCTION: The hamstring muscles play a crucial role in sprint running but are also highly susceptible to strain injuries, particularly within the biceps femoris long head (BFlh). This study compared the adaptations in muscle size and strength of the knee flexors, as well as BFlh muscle and aponeurosis size, after two eccentrically focused knee flexion training regimes: Nordic hamstring training (NHT) vs lengthened state eccentric training (LSET, isoinertial weight stack resistance in an accentuated hip-flexed position) vs habitual activity (no training controls: CON). METHODS: Forty-two healthy young males completed 34 sessions of NHT or LSET over 12 wk or served as CON ( n = 14/group). Magnetic resonance imaging-measured muscle volume of seven individual knee flexors and BFlh aponeurosis area, and maximum knee flexion torque during eccentric, concentric, and isometric contractions were assessed pre- and post-training. RESULTS: LSET induced greater increases in hamstrings (+18% vs +11%) and BFlh (+19% vs +5%) muscle volumes and BFlh aponeurosis area (+9% vs +3%) than NHT (all P ≤ 0.001), with no changes after CON. There were distinctly different patterns of hypertrophy between the two training regimes, largely due to the functional role of the muscles; LSET was more effective for increasing the size of knee flexors that also extend the hip (2.2-fold vs NHT), whereas NHT increased the size of knee flexors that do not extend the hip (1.9-fold vs LSET; both P ≤ 0.001). Changes in maximum eccentric torque differed only between LSET and CON (+17% vs +4%; P = 0.009), with NHT (+11%) inbetween. CONCLUSIONS: These results suggest that LSET is superior to NHT in inducing overall hamstrings and BFlh hypertrophy, potentially contributing to better sprint performance improvements and protection against hamstring strain injuries than NHT.

Transconjunctival Levator Aponeurosis-Müller Muscle Complex Plication to Correct the Acquired Ptosis Following Double-Eyelid Surgery.

One of the most common adverse outcomes of an upper blepharoplasty involving double-eyelid surgery is asymmetric upper eyelids due to unbalanced supratarsal folds or a difference in the palpebral fissure height. This study aimed to evaluate the efficacy and safety of transconjunctival levator aponeurosis-Müller muscle complex plication for correcting acquired ptosis following double-eyelid surgery. This retrospective study evaluated 18 patients who underwent transconjunctival levator aponeurosis-Müller muscle complex plication between June 2016 and June 2019 to correct acquired ptosis. On the basis of the main area of eyelid drooping, ptosis was categorized as central (mid-pupillary), medial (medial limbus), or lateral (lateral limbus). Preoperative and postoperative palpebral fissure heights were measured and compared. Three months postsurgery, the mean difference in palpebral fissure height between bilateral eyes decreased from 0.96 to 0.04 mm in the medial ( P <0.001), from 0.93 to 0.00 mm in central ( P =0.003), and from 1.30 to -0.03 mm in lateral ptosis ( P =0.079). In 13 patients who underwent unilateral correction, the amount of plication was significantly associated with increased palpebral fissure height at the medial limbus ( P =0.043) and mid-pupillary line ( P =0.035). All patients reported a significant improvement in satisfaction. Five patients experienced acute postoperative complications, including chemosis, conjunctival injection, and foreign body sensation, all of which were resolved after a month of observation. No asymmetries or recurrences were observed. Transconjunctival levator aponeurosis-Müller muscle complex plication is a minimally invasive, safe, and effective technique for correcting acquired ptosis following upper eyelid surgery.

A methodological approach for collecting simultaneous measures of muscle, aponeurosis, and tendon behaviour during dynamic contractions.

Skeletal muscles and the tendons that attach them to bone are structurally complex and deform non-uniformly during contraction. While these tissue deformations dictate force production during movement, our understanding of this behaviour is limited due to challenges in obtaining complete measures of the constituent structures. To address these challenges, we present an approach for simultaneously measuring muscle, fascicle, aponeurosis, and tendon behaviour using sonomicrometry. To evaluate this methodology, we conducted isometric and dynamic contractions in in situ rabbit medial gastrocnemius. We found comparable patterns of strain in the muscle belly, fascicle, aponeurosis, and tendon during the isometric trials to those published in the literature. For the dynamic contractions, we found that our measures using this method were consistent across all animals and aligned well with our theoretical understanding of muscle-tendon unit behaviour. Thus, this method provides a means to fully capture the complex behaviour of muscle-tendon units across contraction types.

Cause Analysis and Surgical Treatment of Aponeurotic Ptosis With Upper Eyelid Depression.

BACKGROUND: Ptosis and upper eyelid depression were previously diagnosed as 2 separate diseases. The authors found that in patients with aponeurotic ptosis accompanied by upper eyelid depression, the main cause of upper eyelid depression was impaired dynamic transmission of the levator aponeurosis. OBJECTIVE: To analyze the causes of upper eyelid depression in patients with aponeurotic ptosis accompanied by upper eyelid depression and to introduce the best treatment methods. METHODS: The authors enrolled 15 eyes (11 patients) with aponeurotic ptosis accompanied by upper eyelid depression from October 2021 to August 2022. The authors analyzed the causes of upper eyelid depression in those patients and performed aponeurotic ptosis correction surgery and orbital septum fat release surgery. After 6 to 12 months of follow-up, the authors reviewed the patient's medical records and photographs to evaluate the treatment outcomes. RESULTS: After surgery, ptosis was corrected and upper eyelid depression significantly improved in all the patients. One patient had poor eyelid morphology and upper eyelid depression due to habitual brow lifting, which was relieved after an injection of botulinum toxin into the frontalis muscle. One patient had overcorrection of the upper eyelid depression on the affected side and no other complications. CONCLUSION: The main cause of upper eyelid depression in patients with aponeurotic ptosis is impaired dynamic transmission of the levator aponeurosis. Aponeurotic ptosis repair surgery and orbital septum fat release surgery are simple surgical procedures that restore the normal anatomy and physiology of the upper eyelid and maintain the normal structure of the eyelid, with good post-operative outcomes.

A Modified Algorithm-Based Levator Aponeurectomy in Mild to Moderate Congenital Blepharoptosis.

BACKGROUND: Levator aponeurectomy is a common operation for mild to moderate blepharoptosis. The accuracy of ptosis correction relied on intraoperative judgement when patients were under local anesthesia. For patients who must receive the operation under general anesthesia, it would be an issue to determine how much length of levator aponeurosis to shorten. To solve this issue, we collected data from patients who underwent the operation under local anesthesia and concluded an algorithm. METHODS: This single-center, prospective bivariate regression study allocated patients of mild to moderate congenital blepharoptosis who received levator aponeurectomy under local anesthesia. Preoperative MRD1 and levator function, intraoperative amount of levator aponeurotic shortening, and postoperative MRD1 were measured. The follow-up period was right after the operation. RESULTS: Twenty-nine patients were included in this trial. Two subjects exited because of not receiving allocated operation and data of the other 27 subjects (including 34 eyelids) were analyzed. A scatter diagram was drawn where x axis referred to levator function and y axis referred to the ratio of the amount of shortening of levator aponeurosis over the height of MRD1 correction. Linear regression showed y = - 0.2717*x + 5.026, R2 = 0.8553. CONCLUSION: A modified algorithm to predict the amount of shortening of levator aponeurosis based on levator function and height of ptosis correction was concluded with better accuracy and clinical feasibility. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Variation in the origin of the plantar aponeurosis and its relationship to the origin of the abductor hallucis muscle.

The plantar aponeurosis comprises medial, central, and lateral bands, which arise from the calcaneal tuberosity. Descriptions of the origin of the abductor hallucis vary among different textbooks. The central band and abductor hallucis muscles are related to the windlass mechanism. Given the uncertainties regarding the details of the origins of the central band and the abductor hallucis muscle, we examined those origins in 100 feet of 50 cadavers (25 males and 25 females) by dissection. There were three central band patterns, depending on the attachment sites of the origins of the central and lateral bands: Pattern Ia, the central band covers the lateral band completely; Pattern Ib, the central band covers part of the lateral band; Pattern II, the lateral band covers part of the central band. The origin of the abductor hallucis muscle was confirmed. It showed two types of variation: attachment type, originating from the central band; non-attachment type, not originating from the central band. Central band Patterns Ia, Ib, and II were found in 23 feet (17 males, 6 females), 24 feet (25 males, 28 females), and 24 feet (eight males, 16 females), respectively. Pattern Ia predominated in males and Pattern II in females. The attachment and non-attachment types of abductor hallucis muscle were observed in 28 feet (28%) and 72 feet (72%), respectively. The attachment type with Patterns Ia, Ib, and II was shown in 17 feet, 10 feet, and one foot, respectively. Thus, we revealed variation and sex differences in the central band, which could affect foot morphology and the efficacy of the windlass mechanism.

Release of fibrous web bands between the preaponeurotic fat pad and Levator aponeurosis in subclinical blepharoptosis correction during double-eyelid blepharoplasty.

BACKGROUND: Double-eyelid blepharoplasty is a popular cosmetic procedure in Asia; however, there are some drawbacks to this procedure for mild blepharoptosis. Enhancing movement of the levator aponeurosis can correct blepharoptosis through the release of fibrous web bands present between the preaponeurotic fat pad and levator aponeurosis. AIM: To improve our understanding of the anatomical link between the levator aponeurosis and orbital septum fat and to introduce that the release of the link can provide favorable results in double-eyelid blepharoplasty. PATIENTS/METHODS: We included patients with latent ptosis or subclinical blepharoptosis who underwent double-eyelid blepharoplasty with the release of fibrous web bands between June 2021 and March 2023. Mild ptosis was corrected following complete release of the fibrous bands beneath the preaponeurotic fat pad. Patients were followed up for 4-12 months postoperatively, and surgical outcomes were evaluated. Patient demographic variables and photographs were collected pre- and postoperatively. Patients, surgeons, and laypersons were asked to evaluate the outcomes postoperatively. The Friedman's nonparametric (for repeated measures) two-way analysis of variance was used for statistical analyses. RESULTS: Outcomes were assessed in 45 individuals with an average monitoring period of 6.9 months. There were no cases of incomplete eyelid closure or upper eyelid ectropion. Over 50% of the surgical outcomes were deemed "satisfactory" by each of the three groups in relation to the widening of the eyelid fissure. Most of the examined patients demonstrated favorable long-term results. CONCLUSIONS: Fibrous web bands are implicated in subclinical or mild blepharoptosis. The release of fibrous web bands between the preaponeurotic fat pad and levator aponeurosis can provide favorable results in double-eyelid blepharoplasty.

Biceps femoris long head muscle and aponeurosis geometry in males with and without a history of hamstring strain injury.

OBJECTIVES: Hamstring strain injuries (HSIs) commonly affect the proximal biceps femoris long head (BFlh) musculotendinous junction. Biomechanical modeling suggests narrow proximal BFlh aponeuroses and large muscle-to-aponeurosis width ratios increase localized tissue strains and presumably risk of HSI. This study aimed to determine if BFlh muscle and proximal aponeurosis geometry differed between limbs with and without a history of HSI. METHODS: Twenty-six recreationally active males with (n = 13) and without (n = 13) a history of unilateral HSI in the last 24 months underwent magnetic resonance imaging of both thighs. BFlh muscle and proximal aponeurosis cross-sectional areas, length, volume, and interface area between muscle and aponeurosis were extracted. Previously injured limbs were compared to uninjured contralateral and control limbs for discrete variables and ratios, and along the relative length of tissues using statistical parametric mapping. RESULTS: Previously injured limbs displayed significantly smaller muscle-to-aponeurosis volume ratios (p = 0.029, Wilcoxon effect size (ES) = 0.43) and larger proximal BFlh aponeurosis volumes (p = 0.019, ES = 0.46) than control limbs with no history of HSI. No significant differences were found between previously injured and uninjured contralateral limbs for any outcome measure (p = 0.216-1.000, ES = 0.01-0.36). CONCLUSIONS: Aponeurosis geometry differed between limbs with and without a history of HSI. The significantly larger BFlh proximal aponeuroses and smaller muscle-to-aponeurosis volume ratios in previously injured limbs could alter the strain experienced in muscle adjacent to the musculotendinous junction during active lengthening. Future research is required to determine if geometric differences influence the risk of re-injury and whether they can be altered via targeted training.

Congenital ptosis with aponeurotic maldevelopment: clinical and surgical perspectives : Aponeurotic maldevelopment in congenital ptosis.

PURPOSE: Levator muscle dystrophy has been commonly accused being the main pathology of congenital ptosis, nevertheless, few reports drew attention to the existence of congenital aponeurotic defects. This study aims at highlighting the detailed clinical and surgical features of aponeurotic maldevelopment together with the efficacy of simple aponeurosis repair. METHODS: This is a retrospective nonrandomised study including patients with congenital ptosis who underwent levator muscle surgery throughout 4 years. Patients' records were reviewed for the preoperative clinical assessment and photographs, intraoperative recorded data, and videos as well as postoperative data and photographs. RESULTS: Twenty-seven eyes of 22 patients (9.4%) out of 287 eyes were recorded to have absent levator muscle at its typical anatomical insertion site intraoperatively. The mean preoperative MRD1 was (0.44 ± 1.17 mm). The mean levator function was 8.56 ± 3.89 mm, with higher-than-normal crease position (mean value 10.07 ± 1.62 mm). 25 eyes of included cases (92.6%) showed total absence of the levator aponeurosis edge which only was revealed after cutting through the orbital septal covering of the preaponeurotic fat. CONCLUSION: Congenital aponeurotic defect is an established yet under reported entity of congenital ptosis with reproducible characteristic intraoperative findings. Simple aponeurosis repair could achieve ptosis correction in such cases.

Assessing site-specificity of the biomechanical properties of hamstring aponeuroses using MyotonPRO: A cadaveric study.

BACKGROUND: Hamstring muscles are the most frequently reported sites of muscle strain injuries, especially near the bi-articular muscles' myotendinous junction, where aponeurosis provides a connective tissue network linking muscle fibers to the tendon. This study aimed to investigate the reliability and site-specific differences of hamstring aponeuroses under different conditions (formalin and urea) using MyotonPRO. METHODS: Eight hamstring muscle groups were dissected from four human cadavers (two males and two females) aged 83-93 years. Measurements of the mechanical properties of the aponeuroses from the superficial and deep regions of biceps femoris long head, semitendinosus, and semimembranosus (after formalin solution immersion) were done using MyotonPRO (intra-rater reliability was examined within a 24-h interval), following which the hamstring aponeuroses were measured using a similar procedure after urea solution immersion. FINDINGS: Test-retest (intra-rater) results revealed that the MyotonPRO measurement of tone, stiffness, relaxation, and creep of cadaveric aponeuroses presented good to excellent reliability (ICC: 0.86 to 0.98). There were no significant differences in tone, stiffness, elasticity, relaxation, and creep among the six sites of hamstring aponeuroses under both formalin and urea conditions. Significant differences between formalin and urea conditions were found in the tone, stiffness, relaxation, and creep of hamstring aponeuroses (P < 0.05). INTERPRETATION: These results suggested that the biomechanical properties of hamstring aponeuroses showed homogeneity between the sites using MyotonPRO. Urea solution could potentially neutralize the effect of formalin on the biomechanical properties of cadaveric muscle-aponeurosis-tendon units. The present findings might influence the design of subsequent cadaveric studies on hamstring muscle strains.

Musculoaponeurotic architecture of the human masseter muscle: an in vivo ultrasonographic study of architectural changes during mandibular protrusion and lateral excursions.

OBJECTIVE: The present study evaluated the in vivo musculoaponeurotic architecture of the superficial head (SH) of the masseter muscle (MM) of asymptomatic participants in excursive mandibular movements compared to the relaxed state as examined with ultrasonography. It was hypothesized that the mean fiber bundle length (FBL) and mean height of the aponeurosis (HA) of the laminae of the SH would differ significantly between the relaxed state and protrusion, ipsilateral excursion, and contralateral excursion. STUDY DESIGN: The MM was studied volumetrically in 12 female and 12 male asymptomatic participants bilaterally by using ultrasound imaging. Mean FBL and HA in protrusion and ipsilateral and contralateral excursion were compared to these values in the relaxed state using paired t tests (P < .05). The intraclass correlation coefficient was used to assess intraexaminer reliability. RESULTS: The SH exhibited multiple laminae. Fiber bundles were found to attach to bone and the superior and inferior aponeuroses. Mean FBL was significantly shorter and mean HA significantly longer in protrusion and the excursions than in the relaxed state although the pattern of altered laminae and aponeuroses differed among the mandibular movements. Intraexaminer reliability was excellent. CONCLUSION: Specific changes in mean FBL and mean HA suggest differential contraction of the SH of the MM based on laminar morphology. These findings provide a baseline to investigate musculoaponeurotic changes in patients with myogenic masseter muscle pain.

Influence of muscle length on the three-dimensional architecture and aponeurosis dimensions of rabbit calf muscles.

The function of a muscle is highly dependent on its architecture, which is characterized by the length, pennation, and curvature of the fascicles, and the geometry of the aponeuroses. During in vivo function, muscles regularly undergo changes in length, thereby altering their architecture. During passive muscle lengthening, fascicle length (FL) generally increases and the angle of fascicle pennation (FP) and the fascicle curvature (FC) decrease, while the aponeuroses increase in length but decrease in width. Muscles are differently structured, making their change during muscle lengthening complex and multifaceted. To obtain comprehensive data on architectural changes in muscles during passive length, the present study determined the three-dimensional fascicle geometry of rabbit M. gastrocnemius medialis (GM), M. gastrocnemius lateralis (GL), and M. plantaris (PLA). For this purpose, the left and right legs of three rabbits were histologically fixed at targeted ankle joint angles of 95° (short muscle length [SML]) and 60° (long muscle length [LML]), respectively, and the fascicles were tracked by manual three-dimensional digitization. In a second set of experiments, the GM aponeurosis dimensions of ten legs from five rabbits were determined at varying muscle lengths via optical marker tracking. The GM consisted of a uni-pennated compartment, whereas the GL and PLA contained multiple compartments of differently pennated fascicles. In the LML compared to the SML, the GM, GL, and PLA had on average a 41%, 29%, and 41% increased fascicle length, and a 30%, 25%, and 33% decrease in fascicle pennation and a 32%, 11%, and 35% decrease in fascicle curvature, respectively. Architectural properties were also differentiated among the different compartments of the PLA and GL, allowing for a more detailed description of their fascicle structure and changes. It was shown that the compartments change differently with muscle length. It was also shown that for each degree of ankle joint angle reduction, the proximal GM aponeurosis length increased by 0.11%, the aponeurosis width decreased by 0.22%, and the area was decreased by 0.20%. The data provided improve our understanding of muscles and can be used to develop and validate muscle models.

Mechanical Ptosis by Medial Upper Eyelid Fat Prolapse.

Common symptoms of medial fat pad prolapse may include a noticeable bulge in the inner corner of the upper eyelid, puffiness, and a tired or aged appearance. In some cases, this condition may contribute to mechanical ptosis. However, mechanical ptosis caused by medial upper eyelid fat prolapse has not been reported previously. The purpose of the current study is to report the author's experience of successful treatment of ptosis caused by medial upper eyelid fat prolapse in a 67-year-old woman. The patient complained of slowly aggravating asymmetric upper eyelids starting from 5 years ago. At the time of her visit, she had to use her left forehead to open her eyes, making her left eyebrow upwardly positioned. This condition might be related to medial upper eyelid fat prolapse-related mechanical ptosis. The author explored her left upper eyelid with a 9 mm height incision. The author found a substantial amount of medial fat herniation and levator aponeurosis tear. After fat pad removal, the author fixed the levator aponeurosis tear with nylon 6-0, and transdermal sutures were done. The patient was happy with esthetically pleasing results 2 months after the initial surgery. The author successfully treated this rare condition with basic principles, such as fat removal, levator aponeurosis repair, and transdermal sutures.

Orbital septum attachment site on the levator aponeurosis sling for mild congenital blepharoptosis.

PURPOSE: This study aimed to investigate the value of the orbital septum attachment site on the levator aponeurosis (OSASLA) sling in correcting mild congenital blepharoptosis. METHODS: A total of 60 patients (92 eyes) with mild congenital blepharoptosis (levator function ≥ 8 mm) were treated in our hospital from January to October 2021, and relevant data of these patients were collected. All patients underwent OSASLA sling for ptosis correction. The distances from the superior tarsal border to the OSASLA were measured. The primary outcome was the number of postoperative changes in the marginal reflex distance 1 (MRD1). Pearson's correlation coefficient between the distance from the superior tarsal border to the OSASLA and the height of the upper eyelid elevated was analyzed. RESULTS: Fifty-eight patients (89 eyes) successfully underwent OSASLA sling surgery. The preoperative MRD1 was 1.4-3.6 mm (mean 2.1 ± 0.5 mm), and the postoperative MRD1 was 3.4-5.0 mm (mean 3.7 ± 0.6 mm). The distance from the superior tarsal border to the OSASLA sling was significantly and positively correlated with the height of the upper eyelid elevation (r = 0.7328, P < 0.0001). The eyelid margin positions of the patients did not regress substantially during 6-18 months of follow-up. CONCLUSIONS: Compared with the shortening of levator palpebrae superioris (LPS) and pleating of LPS, the OSASLA sling is a less invasive, more effective, and easy-operating surgery for mild congenital blepharoptosis.

Tarsal Buckling and Entropion after Levator Aponeurosis Advancement in Patients with Floppy Eyelid Syndrome.

Two patients with floppy eyelid syndrome presented with severe eye pain and foreign body sensation after recent levator aponeurosis advancement. The examination in both patients was notable for entropion of the upper eyelid, and upper lid eversion revealed deformity of the tarsus in both patients. Surgical revision with full-thickness horizontal tarsotomy and limited excision of the abnormal tarsus corrected the deformity. The authors propose a mechanism for this phenomenon and a modification of surgical technique that may prevent this complication.