An Apparatus for Measuring Combined Shear-Tensile Loading in Fibrous Tissues Ex Vivo

Soft tissues such as tendon and ligament undergo a combination of shear and tensile loading in vivo due to their boundary conditions at muscle and/or bone. Current experimental protocols are limited to pure tensile loading, biaxial loading, or simple shear, and thus may not fully characterize the mechanics of these tissues under physiological loading scenarios. Our objective was to create an experimental protocol to determine the shear modulus of fibrous tissues at different tensile loads. We assembled a four-actuator experimental system that facilitated shear deformation to be superimposed on a tissue subjected to an axial preload. We measured shear modulus in axially loaded electrospun nanofiber scaffolds with either randomly oriented or aligned fibers. We found that shear modulus in the nanofiber phantoms was shear-strain stiffening and dependent on both the axial load (p < 0.001) and fiber alignment (p < 0.001) of the scaffold. The proposed system can enhance our understanding of microstructure and functional mechanics in soft tissues, while also providing a platform to investigate the behavior of electrospun scaffolds for tissue regeneration. Our experimental protocol for determining loaded shear modulus would be further useful as a method to gauge tissue mechanics under loading conditions that are more representative of physiological loads applied to tendon and ligament.

Racing performance of Thoroughbred racehorses with suspensory ligament branch desmitis treated with mesenchymal stem cells (2010-2019)

BACKGROUND

Suspensory ligament branch desmitis (SLBD) is a common injury in Thoroughbred racehorses. Orthobiologic treatment of these injuries is a relatively new approach, and there is limited information available on post injury racing performance in racehorses treated with mesenchymal stem cells (MSCs).

OBJECTIVES

To assess racing performance post injury in Thoroughbred racehorses with SLBD treated with MSCs.

STUDY DESIGN

Retrospective case series.

METHODS

Medical records of racehorses with SLBD treated with MSCs from 2010 to 2019 were reviewed. All horses were treated with allogeneic stem cells injected locally at the time of diagnosis and subsequently received 3-4 treatments with autologous bone-marrow derived MSCs. Ultrasonographic and radiographic images were evaluated to determine the degree of suspensory branch injury and sesamoiditis of the associated proximal sesamoid bone. Race performance was assessed by career length, class of races, number of starts and earnings post injury. Race performance of horses that raced pre and post injury were compared.

RESULTS

Of 69 treated horses, 71% (49/69) [95% CI: 59%-81%] raced post injury. Horses that had raced pre injury were more likely to race post injury (90% [18/20]) than horses that did not race pre injury (63% [31/49]; p = 0.03). Females were less likely to race post injury than males (52% [11/21] vs. 79% [38/49], respectively; p = 0.02). In the 18 horses that raced pre and post injury, the number of races, earnings and earnings per start were not significantly different pre and post injury. The average career length of all horses that raced post injury was 29.5 months.

MAIN LIMITATIONS

Retrospective study design and lack of controls.

CONCLUSIONS

Treatment with MSCs resulted in a majority of Thoroughbred racehorses with SLBD racing post treatment. Racing pre injury and being male was positively associated with racing post injury.

Specimen-specific finite element representations of implanted hip capsules

The hip capsule is a ligamentous structure that contributes to hip stability. This article developed specimen-specific finite element models that replicated internal-external (I-E) laxity for ten implanted hip capsules. Capsule properties were calibrated to minimize root mean square error (RMSE) between model and experimental torques. RMSE across specimens was 1.02 ± 0.21 Nm for I-E laxity and 0.78 ± 0.33 Nm and 1.10 ± 0.48 Nm during anterior and posterior dislocation, respectively. RMSE for the same models with average capsule properties was 2.39 ± 0.68 Nm. Specimen-specific models demonstrated the importance of capsule tensioning in hip stability and have relevance for surgical planning and evaluation of implant designs.

Endovascular treatment of chronic ilio-femoral vein obstruction with extension below the inguinal ligament in patients with post-thrombotic syndrome

OBJECTIVE

This study aimed to evaluate postoperative outcomes of patients with chronic iliofemoral venous outflow obstruction and post-thrombotic syndrome (PTS) who underwent endovascular recanalization and stenting across the inguinal ligament.

METHODS

All consecutive patients with chronic iliofemoral venous outflow obstruction and PTS were included in the analysis, from January 2018 and February 2022. Preoperative, intraoperative, and postoperative outcomes were assessed. Primary endpoints analyzed were major adverse events (MAEs) at 30 days and primary patency rate at 2 years of follow-up. Secondary endpoints assessed were secondary patency rate, target vessel revascularization, and clinical improvement evaluated with the Venous Clinical Severity Score (VCSS) classification, Villalta scale, and visual analog scale (VAS), respectively.

RESULTS

A total of 63 patients (mean age, 48.1 ± 15.5 years; female, 61.9%) were evaluated. No intraoperative and 30-day postoperative complications were documented. The technical success rate was achieved at 100%. Overall, one in-stent occlusion and five in-stent restenosis were detected during follow-up. The primary patency rate was 93.7% (95% confidence interval [CI], 87.8%-99.9%) and 92.1% (95% CI, 85.6%-99%), at 1- and 2-year follow-up, respectively (Kaplan-Meier analysis). Target vessel revascularization was conducted in two cases, resulting in a secondary patency of 98.4% (95% CI, 95.4%-100%) at 2 years of follow-up. Stent fracture and/or migration were not observed during follow-up. A significant clinical improvement in the patient's quality of life was documented. The median improvement of VCSS and Villalta scores were 4 (interquartile range, 2-7; P = .001), and 3 (interquartile range, 1.5-5; P = .001) vs baseline at the last follow-up. Overall, pain reduction of 17 mm on the VAS scale was documented at 2 years of follow-up. At multivariate analysis, presence of trabeculation into the femoral vein and deep femoral vein (odds ratio, 1.89; 95% CI, 0.15-6.11; P = .043), and Villalta scale >15 points at admission (odds ratio, 1.89; 95% CI, 0.15-6.11; P = .043) were predictive for in-stent occlusion during the follow-up.

CONCLUSIONS

The use of a dedicated venous stent across the inguinal ligament was safe and effective for the treatment of symptomatic iliofemoral venous disease with acceptable primary and secondary patency rates at 2 years of follow-up.

Severe fibromyalgia alleviated by the unique muscle relaxation method of applying low force: A case report

RATIONALE

Fibromyalgia (FM) is characterized by idiopathic persistent chronic pain in the ligaments or musculoskeletal system, and more than half of the patients with FM might have migraine headaches. Direct musculoskeletal intervention could be a non-pharmacological management to relieve symptoms. However, patients with severe FM often have intense pain from only a soft touch, thereby rendering musculoskeletal intervention challenging.

PATIENT CONCERNS

A 47-year-old man had progressing intense pain, and this affected his everyday life. There were no abnormal physical findings on laboratory examination such as levels of complement, antinuclear antibodies, and C-reactive protein, which were within normal limits. Magnetic resonance imaging did not indicate abnormalities.

DIAGNOSES, INTERVENTIONS, AND OUTCOMES

The patient satisfied the American College of Rheumatology criteria. Finally, we made a final diagnosis of fibromyalgia. The therapeutic intervention of Kanshoho, the unique muscle relaxation technique with low force, relieved his pain.

LESSONS

If Kanshoho is carefully applied in a state of hospitalization under surveillance by an experienced physician, it could be a promising muscle relaxation method. Relaxing the trapezius muscle and reducing its intramuscular pressure might be key in treating patients with severe FM. However, it needs elucidation of its mechanism.

A literature review of biomechanical studies on physiological and pathological sacroiliac joints: Articular surface structure, joint motion, dysfunction and treatments

BACKGROUND

Sacroiliac joints are affected by mechanical environments; the joints are formed under mechanical stimulation, receive impact of walking between the upper and lower parts of the bodies and can be a cause of pain due to non-physiological loads. However, there are so far very few studies that reviewed biomechanics of physiological and pathological sacroiliac joints. This review article aims to describe the current sacroiliac joint biomechanics.

METHODS

Previous original papers have been summarized based on three categories: articular surface structure, sacroiliac joint motion and sacroiliac joint dysfunction and treatments.

FINDINGS

Although the articular surface morphologies vary greatly from individual to individual, many researchers have tried to classify the joints into several types. It has been suggested that the surface morphologies may not change regardless of joint dysfunction, however, the relationship between the joint structure and pain are still unclear. The range of sacroiliac joint motion is demonstrated to be less than 1 mm and there is no difference between physiological and pathological joints. The sacroiliac joint absorbs shock within the pelvis by the joint structures of pelvic morphology, ligaments and fat tissues. The morphology and motion of the sacroiliac joints may be optimized for upright bipedal walking.

INTERPRETATION

There is no doubt that pelvic mechanical environments affect pain induction and treatment; however, no one has yet provided a concrete explanation. Future research could help develop treatments based on sacroiliac joint biomechanics to support joint function.

Long-term outcomes of trapeziectomy with Gore-Tex® ligament reconstruction for trapezio-metacarpal osteoarthritis

BACKGROUND

Trapezio-metacarpal osteoarthritis is a common condition for which the reference standard treatment after failure of non-operative measures is trapeziectomy. Several techniques have been devised to avoid proximal migration of the first metacarpal bone (M1) with impingement on the scaphoid bone. We have developed a Gore-Tex® ligament reconstruction technique that avoids potential complications of tendon harvesting. The objective of this study was to assess the long-term outcomes of this technique.

HYPOTHESIS

Trapeziectomy with Gore-Tex® ligament reconstruction is a reliable option for providing lasting pain relief in patients with trapezio-metacarpal osteoarthritis.

MATERIALS AND METHODS

We conducted an observational, single-centre, single-surgeon, retrospective cohort study in consecutive patients managed by primary trapeziectomy. We excluded patients with revision trapeziectomy or less than 10 years' follow-up. The primary outcome was event-free survival, defined as absence of revision surgery and of a numerical rating scale score for pain above 3/10. The secondary criteria were clinical tolerance of the Gore-Tex® implant and radiological changes. The patients were assessed at last follow-up either in person or during a teleconsultation.

RESULTS

Of 78 included joints, 54 were assessed during patient visits and 24 by teleconsultation. At 10 years, the event-free survival rate was 91.3%, and 60.3% of patients were free of pain. Evidence of osteolysis was visible in 24% of patients. No patient experienced clinical intolerance of the Gore-Tex® implant. The mean Disabilities of Arm, Shoulder and Hand score was 25.5. Metacarpo-phalangeal hyperextension was significantly increased, to 30.6°, and the mean trapezial space ratio was significantly decreased, to 39.1% of the baseline value.

CONCLUSION

Long-term event-free survival was high. Functional outcomes and pain were similar to previous reports. Trapeziectomy with Gore-Tex® ligament reconstruction obviates the need for tendon harvesting. Osteolysis developed in some patients but did not correlate with clinical intolerance. Long-term clinical and radiological monitoring is in order after Gore-Tex® implantation.

LEVEL OF EVIDENCE

IV, Observational, single-centre, single-surgeon, retrospective cohort study.

Regional shear wave speeds track regional axial stress in nonuniformly loaded fibrous soft tissues

Ligaments and tendons undergo nonuniform deformation during movement. While deformations can be imaged, it remains challenging to use such information to infer regional tissue loading. Shear wave tensiometry is a promising noninvasive technique to gauge axial stress and is premised on a tensioned beam model. However, it is unknown whether tensiometry can predict regional stress in a nonuniformly loaded structure. The objectives of this study were to (1) determine whether regional shear wave speed tracks regional axial stress in nonuniformly loaded fibrous soft tissues, and (2) determine the sensitivity of regional axial stress and shear wave speed to nonuniform load distribution and fiber alignment. We created a representative set of 12,000 dynamic finite element models of a fibrous soft tissue with probabilistic variations in fiber alignment, stiffness, and aspect ratio. In each model, we applied a randomly selected nonuniform load distribution, and then excited a shear wave and tracked its regional propagation. We found that regional shear wave speed was an excellent predictor of the regional axial stress (RMSE = 0.57 MPa) and that the nature of the regional shear wave speed-stress relationship was consistent with a tensioned beam model (R2 = 0.99). Variations in nonuniform load distribution and fiber alignment did not substantially alter the wave speed-stress relationship, particularly at higher loads. Thus, these findings suggests that shear wave tensiometry could provide a quantitative estimate of regional tissue stress in ligaments and tendons.

Qualitative and Quantitative Anatomy of the Deep Radioulnar Ligaments' Insertion on Ulna: Cadaveric, Histologic, and MRI Study

PURPOSE

To qualitatively and quantitatively analyze the anatomic features of the insertion of deep radioulnar ligaments (RULs) and provide an anatomic basis for further studies.

METHODS

The anatomic features of deep RUL insertion were observed macroscopically in 26 cadaveric wrists, after which the size of the deep RUL footprint and distance from the center of the footprint to the ulnar-sided margin of articular cartilage of the ulnar head were each measured. Five specimens were analyzed histologically to examine the attachment of the RUL on the ulna. In addition, we evaluated 21 asymptomatic wrists from healthy volunteers using 3.0 T magnetic resonance imaging.

RESULTS

The insertion of the deep RUL was located mainly on the radial aspect of the ulnar fovea from the foveal center to the articular cartilage. The footprint of the deep RUL appeared in 3 different shapes. The maximal width, length, and area of the footprint of the deep RUL were 3.7 (95% confidence interval [CI], 3.3-4.0) mm, 8.4 (95% CI, 7.9-8.9) mm, and 26.3 (95% CI, 23.4-29.1) mm2, respectively. Histologic analyses showed the attachment of the deep RUL on the radial wall of the fovea exhibited a direct insertion with typical 4-layer structures. The deep RUL fibers formed an acute angle with the distal component of the triangular fibrocartilage complex.

CONCLUSIONS

The deep RUL was inserted on the radial side of the ulnar fovea and not the foveal center; it had direct insertion on the radial wall continuous with articular cartilage, and the fibers in the direct insertion formed an acute angle with the distal component of the triangular fibrocartilage complex.

CLINICAL RELEVANCE

Understanding the quantitative anatomy of the deep RUL insertion may help guide surgeons to perform an anatomic foveal repair of the triangular fibrocartilage complex in its native footprint.

Ten-year results from the UK National Ligament Registry: Patient characteristics and factors predicting nonresponders for completion of outcome scores

PURPOSE

The aim of this study was to report the demographic and mechanism of injury data in the UK National Ligament Registry (NLR) at 10 years and determine factors leading to poor compliance with completion of Patient-Reported Outcome Scores (PROMs).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary anterior cruciate ligament reconstruction (ACLR) were included. Patient demographics, mechanism of injury and patient compliance with completing PROMs were analysed. Patient characteristics were further analysed in relation to compliance with completing the different PROMs at the predefined time points. Patients were identified as nonresponders if they had not completed either 1- or 2-year postoperative Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

A total of 17,492 patients were included in this study. The average age for patients undergoing ACLR between 2013 and 2022 was 29.4 (SD, 10.3). Seventy percent were men and 30% women. Football was the most common activity associated with an ACL injury. Patient compliance with recording PROMs was 55% preoperatively and 37%, 32% and 24% at 1-, 2- and 5-year postoperative follow-up, respectively. Nonresponders represented 54% of eligible patients. Multivariate analyses showed that sex, age, smoking, time interval between injury and surgery and low socioeconomic status were associated with low compliance with postoperative PROM completion (p < 0.001).

CONCLUSION

This study reports the demographic characteristics for patients on the NLR since 2013. Male sex, young age, increased waiting time between injury and surgery, smoking and lower socioeconomic class were predictors of low compliance with completion of postoperative PROMs on the UK NLR. Understanding the factors that affect patient compliance with PROMs improves our ability to provide targeted interventions and information to specific patient populations with the aim of enhancing inclusiveness and representation of population in the registry.

LEVEL OF EVIDENCE

Level III.

Anatomical analysis of ligaments surrounding calcaneocuboid joint; implications for role in foot stability

PURPOSE

The calcaneocuboid joint is located in the lateral part of the foot and acts as a major stabilizer for the foot. Injuries to this joint often occur in association with ankle or foot injuries and are frequently overlooked, subsequently causing chronic pain or osteoarthritis. However, the relationship between ligaments surrounding the joint and joint instability remains unclear. Therefore, this study aimed to clarify the morphology and position of the ligaments surrounding the calcaneocuboid joint, and to reveal the relationship between the ligament structure.

METHODS

The position and morphology of the bifurcate ligament (subdivided into calcaneonavicular and calcaneocuboid ligaments), dorsal calcaneocuboid ligament, lateral calcaneocuboid ligament, long plantar ligament, and short plantar ligament were measured (N = 11 feet in 6 Japanese cadavers). The circumference of the joint was quartered, while the ligament-uncovered area and the estimated cross-sectional area of each ligament were compared between the four sides. Furthermore, the estimated cross-sectional area of each ligament was calculated as an index for the ligament strength.

RESULTS

The inferolateral side of the calcaneocuboid joint had the most uncovered area (54.63%) by the ligaments. In addition, the cross-sectional area of the ligaments on the lateral side was considerably smaller than that on the medial side.

CONCLUSION

Our results suggest that ligament weakness on the inferolateral side may cause instability of the calcaneocuboid joint, especially after an inversion sprain injury, and may decrease the lateral longitudinal arch function, which results in chronic foot pain.

Erythropoietin receptor signal is crucial for periodontal ligament stem cell-based tissue reconstruction in periodontal disease

Alveolar bone loss caused by periodontal disease eventually leads to tooth loss. Periodontal ligament stem cells (PDLSCs) are the tissue-specific cells for maintaining and repairing the periodontal ligament, cementum, and alveolar bone. Here, we investigated the role of erythropoietin receptor (EPOR), which regulates the microenvironment-modulating function of mesenchymal stem cells, in PDLSC-based periodontal therapy. We isolated PDLSCs from patients with chronic periodontal disease and healthy donors, referred to as PD-PDLSCs and Cont-PDLSCs, respectively. PD-PDLSCs exhibited reduced potency of periodontal tissue regeneration and lower expression of EPOR compared to Cont-PDLSCs. EPOR-silencing suppressed the potency of Cont-PDLSCs mimicking PD-PDLSCs, whereas EPO-mediated EPOR activation rejuvenated the reduced potency of PD-PDLSCs. Furthermore, we locally transplanted EPOR-silenced and EPOR-activated PDLSCs into the gingiva around the teeth of ligament-induced periodontitis model mice and demonstrated that EPOR in PDLSCs participated in the regeneration of the periodontal ligament, cementum, and alveolar bone in the ligated teeth. The EPOR-mediated paracrine function of PDLSCs maintains periodontal immune suppression and bone metabolic balance via osteoclasts and osteoblasts in the periodontitis model mice. Taken together, these results suggest that EPOR signaling is crucial for PDLSC-based periodontal regeneration and paves the way for the development of novel options for periodontal therapy.

Identical anatomy, different symptoms: a comparative case study of median arcuate ligament syndrome in monozygotic twins

Median arcuate ligament syndrome (MALS) is a rare clinical entity arising from the extrinsic compression of the coeliac axis by the median arcuate ligament. In this report, we detail a unique presentation involving monozygotic twins, both of whom demonstrated anatomical extrinsic compression of the coeliac axis by the median arcuate ligament. Intriguingly, only one twin manifested clinical symptoms consistent with MALS, despite comparable anatomical compression of the coeliac axis observed in both. This case highlights the potential interplay of a genetic or anatomical predisposition to coeliac axis compression and secondary, possibly environmental, factors that lead to the development of clinical symptoms. In this report, we explore various determinants potentially influencing symptomatology in MALS and advocate for the publication of similar case studies to further elucidate this rare condition.

The anatomical relationship between the celiac artery and the median arch ligament in degenerative spinal surgery

BACKGROUND

This study aimed to characterize the anatomical relationship between the spine, the celiac artery (CA), and the median arcuate ligament using preoperative contrast-enhanced computed tomography (CT) images of patients with spinal deformity who underwent surgical correction.

METHODS

This retrospective study included 81 consecutive patients (34 males, 47 females; average age: 70.2 years). The spinal level at which the CA originated, the diameter, extent of stenosis, and calcification were determined using CT sagittal images. Patients were divided into two groups: CA stenosis group and non-stenosis group. Factors associated with stenosis were examined.

RESULTS

CA stenosis was observed in 17 (21%) patients. CA stenosis group had significantly higher body mass index (24.9 ± 3.9 vs. 22.7 ± 3.7, p = 0.03). In the CA stenosis group, J-type CA (upward angling of the course by more than 90° immediately after descending) was more frequently observed (64.7% vs. 18.8%, p < 0.001). The CA stenosis group had lower pelvic tilt (18.6 ± 6.7 vs. 25.1 ± 9.9, p = 0.02) than non-stenosis group.

CONCLUSIONS

High BMI, J-type, and shorter distance between CA and MAL were risk factors for CA stenosis in this study. Patients with high BMI undergoing fixation of multiple intervertebral corrective fusions at the thoracolumbar junction should undergo preoperative CT evaluation of the anatomy of CA to assess the poteitial risk of celiac artery compression syndrome.

Incidence of Medial Deltoid Ligament Instability in 226 Patients With Chronic Ankle Instability

The deltoid ligament is vitally important in the stability of the ankle and preventing excessive medial ankle movement. Historically, the impact of medial ankle instability has not been well understood in the setting of chronic ankle instability. A retrospective review of 226 patients treated for ankle instability between 2017 and 2022 identified 40 patients who required both medial and lateral repair. Decision for medial deltoid repair was based upon patient presentation, MRI findings, intraoperative fluoroscopy and final confirmation via arthroscopic positive "drive-through sign". Preoperative and postoperative American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle scores, Patient-Recorded Outcomes Measurement Information System (PROMIS) scores, and Karlsson-Peterson Ankle Function (K&P) scores were obtained and compared. There were statistically significant improvements found in all 3 scoring systems at a mean follow-up time of 11.7 months postoperatively. In the setting of chronic ankle instability, consideration should be given to the evaluation and potential repair of the deltoid ligament in order to provide sufficient stability to the medial ankle.

A comprehensive morphometric analysis of pterygospinous and pterygoalar bars on computed tomography images

This study is aimed to determine the prevalence and morphometric characteristics of the pterygospinous (Ps) and pterygoalar (Pa) bars using computed tomography (CT) images on an extensive study sample of the Anatolian population. The CT images of 700 patients (350 males, 350 females) were analyzed for morphological characteristics and Pa and Ps bars. Ps and Pa bars were classified as complete or incomplete (partial) depending on the degree of ossification. The complete Ps and Pa bars' anteroposterior diameter and craniocaudal diameter were measured. The closest distance between both bony prominences was measured in incomplete Ps and Pa bars. Sex-dependent statistical analysis of the data was performed by the SPSS package program (version 25.0). The prevalence of Ps was 6.57%, and unilateral incomplete Ps was the most frequent Ps type at 5%. The prevalence of Pa was 16.28%, and unilateral incomplete Pa was the most common Pa type at 6.71%. The prevalence of unilateral Ps, unilateral, and bilateral Pa was more common in males (P = .014, P = .006, and P = .032, respectively). Although Ps were less frequently encountered, both anatomic variations were relatively common within the population. The prevalence and morphometric characteristics of Ps and Pa bars obtained in this study could serve as guiding insights for the practices of surgeons, anesthesiologists, dentists, and radiologists.

Directing ligament-mimetic bi-directional cell organization in scaffolds through zone-specific microarchitecture for ligament tissue engineering

Ligament tissues exhibit zone-specific anisotropic cell organization. The cells in ligament-proper are longitudinally oriented, whereas, the cells in epiligament are circumferentially oriented. Therefore, scaffolds developed to regenerate ligament tissues should possess adequate architectural features to govern ligament-mimetic bi-directional cell organization. The scaffold architectural features along with ligament-mimetic cell organization may ultimately yield neo-tissues with ligament-like extracellular matrix (ECM) structure and biomechanical properties. Towards this goal, we fabricated a silk/gelatin-based core-shell scaffold (csSG) with zone-specific anisotropic architectural features, wherein, the core of the scaffold possessed longitudinally aligned pores while the shell of the scaffold possessed parallel microgrooves that are aligned circumferentially around the surface of the scaffold. The ligament-mimetic architectural features significantly improved the mechanical properties of the scaffold. Moreover, architectural features of the csSG scaffold governed zone-specific anisotropic organization of cells. The cells in the core were longitudinally oriented as observed in the ligament-proper and the cells on the shell were circumferentially oriented as observed in epiligament. This bi-directional cell orientation partially mimicked the complex cellular network in native ligament tissue. Additionally, both the core and the shell individually supported fibrogenic differentiation of stem cells which further improved their potential for ligament tissue engineering. Further, the aligned pores of the core could govern unidirectional organization of ECM deposited by cells which is crucial for regenerating anisotropic tissues like ligaments. Finally, when implanted subcutaneously in mice, the scaffolds retained their anisotropic architecture for at least 2 weeks, were biocompatible, supported cell infiltration and governed anisotropic organization of cells and ECM. Taken together, the fabricated biomimetic csSG scaffold, through its zone-specific architectural features, could govern ligament-mimetic cellular and ECM organization which is ultimately expected to achieve regeneration of ligament tissues with native-like hierarchical structure and biomechanical properties. Consequently, this study introduces bi-directional structural parameters as design criteria for developing scaffolds for ligament tissue engineering.

Correlation between vascular endothelial growth factor A gene polymorphisms and tendon and ligament injury risk: a systematic review and meta-analysis

BACKGROUND

Relevant evidence suggests that angiogenic factors contribute significantly to fibril matrix reconstruction following physical injuries to tendon ligaments. Vascular endothelial growth factor A (VEGFA), with its potent angiogenic effect, has been studied extensively, and its functional polymorphisms, including rs699947, rs1570360, and rs2010963, have been the focus of numerous investigations. Some scholars have explored the association between gene polymorphisms in the VEGFA and the risk of tendon ligament injury, but the findings are not entirely consistent.

OBJECTIVES

The purpose of this study was to investigate the association between rs699947, rs1570360, and rs2010963 gene polymorphisms in VEGFA and the risk of tendon and ligament injuries.

METHODS

After including articles about the association of VEGFA rs699947, rs1570360, and rs2010963 polymorphisms with tendon and ligament injuries according to the search strategy, we assessed their quality and conducted meta-analyses to examine the link between these polymorphisms and the risk of tendon and ligament injuries using odds ratios and 95% confidence intervals.

RESULTS

Of 86 related articles, six were included in the meta-analysis. Some of these suggest an association between VEGFA rs2010963 and the risk of tendon and ligament injury in the population, with the specific C allele being one of the adverse factors for knee injury. Some studies suggest that VEGFA rs699947 and VEGFA rs1570360 single-nucleotide polymorphisms are associated with anterior cruciate ligament rupture. The risk of non-contact anterior cruciate ligament rupture is nearly doubled in individuals with the rs699947 CC genotype compared to the control group. Our analysis did not find any significant relationship between VEGFA gene polymorphisms (rs699947, rs1570360, and rs2010963) and the chance of tendon and ligament injury without consideration of race. However, the European population reveals that the CC genotype of VEGFA rs699947 can result in a greater risk of tendon and ligament injury, whereas the AG genotype for rs1570360 provides some protection. Additionally, rs2010963 was significantly associated with tendon and ligament injury; individuals with the C allele and the CC genotype had higher risk. False-positive report probability confirmed the high credibility of our results.

CONCLUSION

Overall, this study found no significant association between VEGFA rs699947, rs1570360, and rs2010963 polymorphisms and the risk of tendon ligament injury. However, in subgroup analysis, some genotypes of VEGFA rs699947, rs1570360, and rs2010963 were found to increase the risk of tendon ligament injury in European populations.

Enthesis repair - State of play

The fibrocartilaginous enthesis is a highly specialised tissue interface that ensures a smooth mechanical transfer between tendon or ligament and bone through a fibrocartilage area. This tissue is prone to injury and often does not heal, even after surgical intervention. Enthesis augmentation approaches are challenging due to the complexity of the tissue that is characterised by the coexistence of a range of cellular and extracellular components, architectural features and mechanical properties within only hundreds of micrometres. Herein, we discuss enthesis repair and regeneration strategies, with particular focus on elegant interfacial and functionalised scaffold-based designs.

Pudendal Nerve Block With Liposomal Bupivacaine for Sacrospinous Ligament Suspension

IMPORTANCE

Pudendal nerve block has been frequently used as a pain management modality for vaginal prolapse surgery. However, studies investigating its efficacy and the type of anesthetic used have had conflicting results.

OBJECTIVE

This study aimed to evaluate the effect of intraoperative pudendal nerve block with liposomal bupivacaine on postoperative pain after sacrospinous ligament suspension surgery.

STUDY DESIGN

In this single-blinded randomized controlled trial, 83 women undergoing sacrospinous ligament suspension were randomized to receive either intraoperative pudendal nerve block with liposomal bupivacaine or no block. Participants recorded their pain level on postoperative days (PODs) 1-3 and 7, the number of pain medication pills consumed, and the quality of their recovery using a validated questionnaire.

RESULTS

There were no significant differences in pain scores between the groups on POD 1 and POD 3: 5 (2-6.25) versus 5.5 (4-8; P = 0.058) and 4 (1-6) versus 5 (2-7; P = 0.146), respectively. On POD 2, the overall pain score was statistically different between the groups, with the block group having lower interquartile ranges. This difference, however, was not clinically significant: 5 (1.75-5) versus 5 (3.25-7.75; P = 0.023). In the subset of participants who underwent a concomitant midurethral sling procedure, POD 2 and POD3 pain scores were significantly lower in those who received the block: 3 (1-5) versus 6 (5-8; P = 0.006) for POD 2 and 3 (1-5) versus 5 (3.250-7; P = 0.042) for POD 3. There were no significant differences in pain medication consumption or the quality of recovery scores.

CONCLUSION

Pudendal nerve block with liposomal bupivacaine did not result in significant differences in postoperative pain after sacrospinous ligament suspension, except in those participants who underwent a concomitant midurethral sling procedure.

Cell Sheet Technology: An Emerging Approach for Tendon and Ligament Tissue Engineering

Tendon and ligament injuries account for a substantial proportion of disorders in the musculoskeletal system. While non-operative and operative treatment strategies have advanced, the restoration of native tendon and ligament structures after injury is still challenging due to its innate limited regenerative ability. Cell sheet technology is an innovative tool for tissue fabrication and cell transplantation in regenerative medicine. In this review, we first summarize different harvesting procedures and advantages of cell sheet technology, which preserves intact cell-to-cell connections and extracellular matrix. We then describe the recent progress of cell sheet technology from preclinical studies, focusing on the application of stem cell-derived sheets in treating tendon and ligament injuries, as well as highlighting its effects on mitigating inflammation and promoting tendon/graft-bone interface healing. Finally, we discuss several prerequisites for future clinical translation including the selection of appropriate cell source, optimization of preparation process, establishment of suitable animal model, and the fabrication of vascularized complex tissue. We believe this review could potentially provoke new ideas and drive the development of more functional biomimetic tissues using cell sheet technology to meet the needs of clinical patients.

Biomechanical evaluation of the anterior talo-fibular and calcaneo-fibular ligaments using shear wave elastography in young healthy adults

BACKGROUND

The objective of this study was to evaluate the stiffness of the anterior talo-fibular ligament (ATFL) and calcaneo-fibular ligament (CFL) using shear wave elastography (SWE) with the ankle in the neutral position and in varus, in young healthy adult volunteers. We also evaluated the reliability and reproducibility of the SWE measurements.

HYPOTHESIS

The stiffness of both ligaments increases with increasing ankle varus. SWE may be a reliable tool for evaluating the lateral collateral ligament complex of the ankle.

MATERIAL AND METHODS

We used SWE to evaluate both ankles of each of 20 healthy volunteers (10 females and 10 males). For each test, the foot was placed on a hinged plate and tested in the neutral position and in 15° and 30° of varus. Stiffness was evaluated based on shear wave velocity (SWV).

RESULTS

Stiffness of both the ATFL and CFL was minimal in the neutral position (2.06m/s and 3.43m/s, respectively). Stiffness increased significantly for both ligaments in 15° of varus (2.48m/s and 4.11m/s, respectively; p<0.0001) and was greatest in 30° of varus (3.15m/s and 4.57m/s, respectively; p<0.0001). ATFL stiffness was greater in males than in females in 15° (p=0.04) and 30° (p=0.02) of varus. For the CFL, in contrast, stiffness was not different between males and females. Stiffness of the ATFL and CFL was not associated with age, dominant side, height, or foot morphology. No correlations were found between stiffness of the two ligaments in any of the positions. Repeating each measurement three times produced excellent concordance for both ligaments in all three positions.

CONCLUSION

The ATFL and CFL are the main lateral stabilisers of the ankle, and each exerts a specific function. Their stiffness increases with the degree of varus. This study describes a protocol for evaluating ATFL and CFL density by SWE, which is a reliable and reproducible technique that provides a normal range.

LEVEL OF EVIDENCE

IV.

Could medial malleolus fracture be combined with deltoid ligament injury?: A rare case report

RATIONALE

Medial malleolus injuries mainly comprise of fractures and deltoid ligament ruptures. Medial malleolus fractures, as a kind of common ankle fractures, could occur separately or be accompanied by lateral and posterior malleolus fractures. It is generally agreed that medial malleolus fracture and deltoid ligament rupture could not occur simultaneously.

PATIENT CONCERNS

In our study, we report a case of 36 year-old man diagnosed with trimalleolar fracture accompanying ankle dislocation initially. The patient was admitted to our hospital due to traffic accident.

DIAGNOSIS

The patient was diagnosed with trimalleolar fracture accompanying ankle dislocation initially. We missed the diagnosis of accompanied deltoid ligament due to the arthralgia of medial ankle and the widened medial articular space in X-ray after operation.

INTERVENTION

As we missed the diagnosis of accompanied deltoid ligament, we only selected open reduction and internal fixation for trimalleolar fracture at first. After we realized the existence of deltoid ligament rupture, the patient refuse further diagnosis and treatment in our hospital.

OUTCOMES

During the rehabilitation exercise, the patient had medial arthralgia in his right ankle. He complained it and refuse further diagnosis and treatment in our hospital.

LESSONS

The newfound injury pattern, medial malleolus fracture accompanying deltoid ligament rupture, has not been reported in previous studies. The injury pattern needs further researches to explore the mechanism and it should be taken seriously in clinical practice.

[Red flags of cardiac amyloidosis in patients with spinal stenosis and yellow ligament hypertrophy]

INTRODUCTION

Studies addressing the prevalence of cardiac amyloidosis (CA) among patients with spinal stenosis (SS) are lacking. The identification of the red flags (RF) of CA could lead to early detection of cases of CA. The primary objective of this study was to address the prevalence of RF of CA among patients with SS.

METHODS

Transversal study including consecutive cases with SS and yellow ligament hypertrophy (YLH). A clinical assessment that included electrocardiogram, echocardiogram and urine and blood test was performed. A clinical suspicion of CA was defined by the presence of left ventricular hypertrophy plus any RF.

RESULTS

One hundred and three patients with SS and YLH were assessed. The prevalence of RF was high: heart failure: 18.4%; aortic stenosis: 1.9%; carpal tunnel syndrome: 7.8%; bicipital tendon rupture: 1.9%; arterial hypotension: 17.4%; polyneuropathy symptoms: 51.5%; pseudoinfarction pattern: 3.9%; low voltages: 15.5%; conduction abnormalities: 15.5%; decreased longitudinal strain: 25.3%; apical sparing pattern: 3.9%. The 57.3% of the cohort met the CA suspicion criteria.

CONCLUSION

The prevalence of RF of CA is high among patients with SS and YLH. A high proportion of patients met the CA suspicion criteria.

Does robotic-assisted unicompartmental knee arthroplasty restore native joint line more accurately than with conventional instruments?

The study's primary aim is the restoration of native joint line in patients having robotic-assisted unicondylar knee arthroplasty and conventional unicondylar knee arthroplasty. Literature in the past has demonstrated that reducing the joint line can result in greater failure rates. This is a prospective cohort investigation of patients who had medial UKA between March 2017 and March 2022.All patient's pre-operative and post-operative radiological joint line assessments were examined by two observers by Weber's methods. Robotic-assisted UKA performed with hand-held image-free robots was compared to conventional UKA groups. The distal position of the femoral component was higher in Group B utilizing conventional tools than in Group A employing robotic-assisted UKA. This positional difference was statistically significant. The mean difference among the pre-operative and post-operative joint lines in Group A was 1.6 ± 0.49 (range 0.8 mm-2.4 mm), while it was 2.47 ± 0.51 (range 1.6 mm-3.9 mm) (p 0.005) in Group B. In Group A, a greater percentage of the subjects (64%) attained a femoral component position within two millimeters from the joint line, whereas just 18% in Group B did. When compared with the conventional UKA technique, the meticulous attention to detail and planning for ligament rebalancing when using the robotic-assisted UKA technique not solely enhance surgical precision for implant placing but additionally provides excellent native joint line restoration and balancing. For validation of its longevity and survivability, the cohort must be tracked for a longer period of time.

Rational design of viscoelastic hydrogels for periodontal ligament remodeling and repair

The periodontal ligament (PDL) is a distinctive yet critical connective tissue vital for maintaining the integrity and functionality of tooth-supporting structures. However, PDL repair poses significant challenges due to the complexity of its mechanical microenvironment encompassing hard-soft-hard tissues, with the viscoelastic properties of the PDL being of particular interest. This review delves into the significant role of viscoelastic hydrogels in PDL regeneration, underscoring their utility in simulating biomimetic three-dimensional microenvironments. We review the intricate relationship between PDL and viscoelastic mechanical properties, emphasizing the role of tissue viscoelasticity in maintaining mechanical functionality. Moreover, we summarize the techniques for characterizing PDL's viscoelastic behavior. From a chemical bonding perspective, we explore various crosslinking methods and characteristics of viscoelastic hydrogels, along with engineering strategies to construct viscoelastic cell microenvironments. We present a detailed analysis of the influence of the viscoelastic microenvironment on cellular mechanobiological behavior and fate. Furthermore, we review the applications of diverse viscoelastic hydrogels in PDL repair and address current challenges in the field of viscoelastic tissue repair. Lastly, we propose future directions for the development of innovative hydrogels that will facilitate not only PDL but also systemic ligament tissue repair. STATEMENT OF SIGNIFICANCE.

Morphology of Fibular Incisura is a Deciding Factor Between Posterior Malleolus Avulsion Fracture or Syndesmotic Ligament Injury in Ankle Fractures

The bone anatomy of tibiofibular syndesmosis has been a topic of interest. Fibular incisura morphology has been analyzed on cadaver specimens, plain radiographs, or CT images. The aim of this study is to examine the effects of fibula incisura features and fibula morphology in ankle injuries, especially involving posterior malleolus and posteroinferior tibiofibular ligament injuries. From 2017 through 2022, A total of 59 patients with isolated lateral malleolar fracture, Mason-Malloy type 1 posterior malleolar fracture, syndesmosis injury in those without posterior malleolar fracture, supination external rotation type 3 injuries according to Lauge-Hansen classification, and preoperative bilateral ankle computed tomography images were included in the study. Fibula morphologies and syndesmosis measurements were made from preoperative computed tomography images using axial CT images from 1 cm proximal to the tibial plafond. The diagnosis of posterior malleolar fractures was made using the CT classification system of Mason and Malloy, and the diagnosis of syndesmosis injury was made with a cotton test during surgery. Age, gender, fractured side, incisura type, incisor depth, width, anterior and posterior facet lengths, incisor version (antevert-retrovert), the angle between the anterior and posterior facets, and fibula type were recorded. There was a statistically significant difference between the groups in posterior facet length and incisura width. Morphological features of fibular incisura may be the determinant of PITFL injury or PMA injury in fibular fractures caused by an external rotation mechanism.

Plasma pentosidine concentration is associated with ligament ossification and high-grade osteoarthritis: The ROAD study

AIM

No studies have examined the association between plasma pentosidine levels and ossification diseases in large cohorts of Japanese residents. This study aimed to investigate the association between cervical ossification of the posterior longitudinal ligament (OPLL) and other ossification diseases, including diffuse idiopathic skeletal hyperostosis, lumbar spondylosis and knee osteoarthritis (OA), by examining plain radiographs of the knee, and cervical, thoracic and lumbar spine from 1690 participants, and the association between these diseases and plasma pentosidine.

DESIGN

We enrolled 1690 participants (596 men and 1094 women) from mountainous and coastal areas from the study population of the previous Research on Osteoarthritis/Osteoporosis Against Disability study. X-ray examination of the cervical/thoracic/lumbar spine and knee was carried out only in these individuals, and not those from urban areas. Plasma pentosidine concentrations were determined using enzyme-linked immunoassays.

RESULTS

Radiographic OPLL was detected in 30 (17 men, 13 women) of 1562 individuals who underwent X-ray examination of the cervical spine. OPLL, diffuse idiopathic skeletal hyperostosis, lumbar spondylosis Kellgren-Lawrence (KL) grade, and knee OA KL grade were associated with high plasma pentosidine concentrations (all P < 0.05). Furthermore, significant intragroup differences (KL grade 4 vs 3) of plasma pentosidine concentration were observed between the lumbar spondylosis and knee OA groups. The plasma pentosidine concentration was significantly associated with age, OPLL, lumbar spondylosis (KL grade 4) and knee OA (KL grade 4).

CONCLUSIONS

OPLL is significantly associated with other ossification diseases. The development of more severe OA might lead to the accumulation of plasma pentosidine. Plasma pentosidine levels were associated with OPLL and severe OA. Geriatr Gerontol Int 2024; 24: 154-160.

Inhibiting JAK1, not NF-κB, reverses the effect of pro-inflammatory cytokines on engineered human ligament function

The role of inflammation in chronic tendon/ligament injury is hotly debated. There is less debate about inflammation following acute injury. To better understand the effect of acute inflammation, in this study we developed a multi-cytokine model of inflammatory tendinitis. The combined treatment with TNF-α, IL-1β, and IL-6, at dosages well below what are routinely used in vitro, decreased the mechanical properties and collagen content of engineered human ligaments. Treatment with this cytokine mixture resulted in an increase in phospho-NF-κB and MMP-1, did not affect procollagen production, and decreased STAT3 phosphorylation relative to controls. Using this more physiologically relevant model of acute inflammation, we inhibited NF-κB or JAK1 signaling in an attempt to reverse the negative effects of the cytokine mixture. Surprisingly, NF-κB inhibition led to an even greater decrease in mechanical function and collagen content. By contrast, inhibiting JAK1 led to an increase in mechanical properties, collagen content and thermal stability concomitant with a decrease in MMP-1. Our results suggest that inhibition of JAK1, not NF-κB, reverses the negative effects of pro-inflammatory cytokines on collagen content and mechanics in engineered human ligaments.

Outcomes of multiligament knee injury treated with versus without internal brace suture augmentation

PURPOSE

To compare the postoperative outcomes between Internal Brace (IB) and non-IB patients who underwent surgical management of multiple-ligament knee injuries (MLKI).

METHODS

Patients who underwent surgical management of MLKI at two institutions between 2010 and 2020 were identified and offered participation in the study via the collection of postoperative functional outcomes for MLKI; Lysholm Knee score, Multiligament Quality of Life (ML-QOL), Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive testing (CAT), Pain Interference (PI), Physical Function (PF), and Mobility instruments (MI). The postoperative outcomes and reoperation rates were compared between the IB group and non-IB group.

RESULTS

One hundred and twenty-six patients were analyzed; 89 were included in the IB group (31.5% female; age 35.6 ± 1.4 years), and 37 were included in the non-IB group (25.7% female; age 38.8 ± 2.4 years). Mean follow-up time of the entire cohort was 37.9 ± 4.7 months [IB: 21.8 + 1.63; non-IB: 76.4 ± 6.2, p < 0.001). The IB group achieved similar PROMIS CAT [PROMIS Pain (51.8 + 1.1 vs. 52.1 + 1.6, p = 0.8736), Physical Function (46.6 + 1.2 vs. 46.4 + 1.8, p = 0.9168), Mobility (46.0 + 1.0 vs. 43.7 + 1.6, p = 0.2185)], ML-QOL [ML-QOL Physical Impairment (36.6 + 2.5 vs. 43.5 ± 4.2, p = 0.1485), Emotional Impairment (42.5 + 2.9 vs. 48.6 ± 4.6, p = 0.2695), Activity Limitation (34.5 + 2.8 vs. 36.2 ± 4.3, p = 0.7384), Societal Involvement (39.1 + 3.0 vs. 41.7 + 4.2, p = 0.6434)] and Lysholm knee score (64.9 + 2.5 vs. 60.4 + 4.0, p = 0.3397) postoperatively compared the non-IB group, but the differences were not significant.

CONCLUSION

In this cohort of patients with MLKI treated with versus without IB, outcomes and reoperation rates trended toward favoring IB, but the study was not sufficiently powered to reach statistical significance. Internal bracing could be useful in the management of MLKI. In the future, matched patient cohorts with more patients are warranted to further evaluate the clinical impact of the internal brace in MLKI.

Celiac trunk thrombosis in a patient with antiphospholipid syndrome induced by median arcuate ligament compression: a case presentation and literature review

Median arcuate ligament syndrome (MALS) is a rare disorder caused by the compression of the celiac axis by the fibrous structure of the diaphragm called the median arcuate ligament. Patients with MALS are usually undiagnosed unless characteristic symptoms such as nausea and vomiting, postprandial pain, and weight loss are presented. We report a case of a 29-year-old patient diagnosed with MALS and secondary antiphospholipid syndrome (APS) that developed celiac trunk, common hepatic artery and splenic artery thrombosis. There is not enough information on MALS as a trigger of thrombosis in predisposed patients such as those with APS. However, the case gives rise to suspicion and highlights the diagnostic processes, especially for patients with APS presenting postprandial abdominal pain and weight loss. This review likewise aims at the importance of Doppler ultrasonography as a screening tool and computer tomography (CT) or magnetic resonance (MR) both in the angiography variant, especially to diagnose confirmation and underlying treatment options.

Prevalence and Injury Patterns of CFL Injury in Chronic Lateral Ankle Instability: An Observational Cross-Sectional Study Using Ultrasound

The purpose of this paper is to assess the prevalence and injury patterns of the calcaneofibular ligament (CFL) in chronic lateral ankle instability (CAI) patients using ultrasound imaging. This retrospective study included 938 ankle ultrasound images from January 2016 to May 2018. The patients' demographic data and the injury pattern classified by the injury location and the remnant quality were recorded and correlated using t tests, Fisher's exact tests, and post hoc tests accordingly. Of the 938 CAI patients, CFL injury was found in 408/938 (44%). Among the 408 anterior talofibular ligament (ATFL) and CFL complex injury patients, 71/408 (17%) presented with a completely absorbed ATFL, whereas 13/71 (18%) presented with an absorbed CFL. The total CFL absorption proportion in all patients was relatively low (30/938 = 3%). Post hoc tests indicated a negative association between thickened ATFLs and complex injuries. In addition, a positive association existed between absorbed ATFLs and complex injuries as well as absorbed ATFLs and absorbed CFLs. Thus, the results indicated that total tearing and absorption injury patterns of the CFL in CAI are not common. Even when the ATFL is absorbed, only approximately one-fifth (13/71 = 18%) of CFLs require reconstruction, suggesting that it is unnecessary to routinely repair or reconstruct CFLs in all lateral ligament surgeries.

Advancements in scaffold for treating ligament injuries; in vitro evaluation

Tendon/ligament (T/L) injuries are a worldwide health problem that affects millions of people annually. Due to the characteristics of tendons, the natural rehabilitation of their injuries is a very complex and lengthy process. Surgical treatment of a T/L injury frequently necessitates using autologous or allogeneic grafts or synthetic materials. Nonetheless, these alternatives have limitations in terms of mechanical properties and histocompatibility, and they do not permit the restoration of the original biological function of the tissue, which can negatively impact the patient's quality of life. It is crucial to find biological materials that possess the necessary properties for the successful surgical treatment of tissues and organs. In recent years, the in vitro regeneration of tissues and organs from stem cells has emerged as a promising approach for preparing autologous tissue and organs, and cell culture scaffolds play a critical role in this process. However, the biological traits and serviceability of different materials used for cell culture scaffolds vary significantly, which can impact the properties of the cultured tissues. Therefore, this review aims to analyze the differences in the biological properties and suitability of various materials based on scaffold characteristics such as cell compatibility, degradability, textile technologies, fiber arrangement, pore size, and porosity. This comprehensive analysis provides valuable insights to aid in the selection of appropriate scaffolds for in vitro tissue and organ culture.

A Cadaveric Study of the Optimal Isometric Region on the Anterolateral Surface of the Knee in Anterolateral Ligament Reconstruction

OBJECTIVE

Isolated intra-articular anterior cruciate ligament (ACL) reconstruction is not capable of restoring instability in many cases leading some to recommend concomitant anterolateral ligament (ALL) reconstruction. The satisfactory fixation site and graft length change are crucial in ligament reconstruction to restore the ALL function and avoid some unwanted graft behavior. The purpose of this investigation is to determine the optimal isometric region on the anterolateral aspect of the knee for ALL reconstruction using a three-dimensional optical instrument and a suture similar to an intraoperative isometric test.

METHODS

Six freshly frozen cadaveric human knees were used in this study. Data regarding the anterolateral surface were obtained using an optical measurement system to create a three-dimensional model. Nine points were selected on the femur (F1-F9) and tibia (Ta-Ti) respectively. The three-dimensional length change between each pair of tibial and femoral points was measured during passive knee flexion from 0° to 90° in 15° increments. Subsequently, five femoral points (A-E) were selected from the lateral femur, located in different areas relative to the lateral femoral epicondyle, and three tibial reference points (T1-T3) were selected in the isometric test. The changes in the length between each pair of reference points were measured using sutures. The 95% confidence interval for the rate of length change was estimated using the mean and standard deviation of the maximum rate of length change at different flexion angles, and the data were expressed as the mean (95% confidence interval) and compared with the maximum acceptable rate of change (10%).

RESULTS

The maximum acceptable change rate for ligament reconstruction is 10%, and the mean maximum rates and the 95% confidence interval (CI) of length change for the point combinations were calculated. Among all the combined points measured using the optical measurement system and the suture, the qualified point combination for reconstruction was F3 (8mm posterior and 8mm proximal to the lateral femoral epicondyle)-Tb (8mm proximal to the midpoint between the center of Gerdy's tubercle and the fibula head), A (posterior and proximal to the lateral femoral epicondyle)-T2 (10mm below the joint line)and A-T3 (15 mm below the joint line). The position of F3-Tb and A-T2 are close to each other.

CONCLUSION

The most isometric area of the femur for ALL reconstruction was posterior and proximal to the lateral femoral epicondyle. We recommend that the initial location of the femoral point be set at 8 mm posterior and 8 mm proximal to the lateral femoral epicondyle and the tibial point at approximately 10 mm below the joint line, midway between Gerdy's tubercle and fibular head, and subsequently adjusted to the most satisfactory position according to the isometric test.

Kirschner Wire Internal Fixation of the Medial Tibiotalar Joint for Indirect Repair of Deltoid Ligament Injury: A Retrospective Comparative Study

OBJECTIVE

Ankle joint fractures are often accompanied by medial deltoid ligament rupture. There is controversy over whether or how to treat deltoid ligament rupture. This study was aimed to explore the feasibility of repairing the medial deltoid ligament using Kirschner wire internal fixation of the medial tibiotalar joint combined with external fixation.

METHODS

Forty-six patients with ankle fractures involving deltoid ligament rupture, treated between October 2012 and February 2021, were retrospectively evaluated. Twenty-five patients were treated with a Kirschner wire to fix the tibiotalar joint and indirectly repair the deltoid ligament as the repaired group. Twenty-one patients underwent reduction and fixation of internal and external malleolus fractures, and the deltoid ligament was not repaired in the unrepaired group. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analog scale (VAS), Medical Outcomes Short Form 36-item questionnaire score (SF-36), and Medial clear space perpendicular (preoperative, postoperative, final follow-up) were used for functional evaluations and reduction assessments. Mann-Whitney test were used to compare the differences between the groups.

RESULTS

The follow-up time was 13-112 months with a mean of 59.32 months for the repaired group and 11-94 months with a mean of 53.43 months for the unrepaired group. There was no significant difference in the operative time or intraoperative blood loss between the two groups (p > 0.05). At the last follow-up, the AOFAS ankle-hindfoot and SF-36 scores of the repaired group were significantly higher than those of the non-repaired group (p < 0.05). Moreover, the VAS pain score was significantly lower and the Medial clear space perpendicular was significantly narrower in the repaired group than that in the unrepaired group.

CONCLUSION

Tibiotalar joint fixation using Kirschner wires is a simple and effective technique that can indirectly reduce and repair the deltoid ligament and stabilize the ankle.

Application of Nondegradable Synthetic Materials for Tendon and Ligament Injury

Tendon and ligament injuries, prevalent requiring surgical intervention, significantly impact joint stability and function. Owing to excellent mechanical properties and biochemical stability, Nondegradable synthetic materials, including polyethylene terephthalate (PET) and polytetrafluoroethylene (PTFE), have demonstrated significant potential in the treatment of tendon and ligament injuries. These above materials offer substantial mechanical support, joint mobility, and tissue healing promotion of the shoulder, knee, and ankle joint. This review conclude the latest development and application of nondegradable materials such as artificial patches and ligaments in tendon and ligament injuries including rotator cuff tears (RCTs), anterior cruciate ligament (ACL) injuries, and Achilles tendon ruptures.

The major influence of anterior and equatorial zonular fibres on the far-to-near accommodation revealed by a 3D pre-stressed model of the anterior eye

PURPOSE

To explore the synergistic function of the ligaments in eye, the zonular fibres, that mediate change in eye lens shape to allow for focussing over different distances.

METHODS

A set of 3D Finite Element models of the anterior eye together with a custom developed pre-stress modelling approach was proposed to simulate vision for distant objects (the unaccommodated state) to vision for near objects (accommodation). One of the five zonular groups was cut off in sequence creating five models with different zonular arrangements, the contribution of each zonular group was analysed by comparing results of each specific zonular-cut model with those from the all-zonules model in terms of lens shape and zonular tensions.

RESULTS

In the all-zonular model, the anterior and equatorial zonules carry the highest tensions. In the anterior zonular-cut model, the equatorial zonular tension increases while the posterior zonular tension decreases, resulting in an increase in the change in Central Optical Power (COP). In the equatorial zonular-cut model, both the anterior and posterior zonular tensions increase, causing a decreasing change in COP. The change in COP decreases only slightly in the other models. For vitreous zonular-cut models, little change was seen in either the zonular tension or the change in COP.

CONCLUSIONS

The anterior and the equatorial zonular fibres have the major influence on the change in lens optical power, with the anterior zonules having a negative effect and the equatorial zonules contributing a positive effect. The contribution to variations in optical power by the equatorial zonules is much larger than by the posterior zonules.

The Relationship Between Patient-Reported Outcomes and Patient Satisfaction With Ligament Reconstruction Tendon Interposition

PURPOSE

Achieving the minimal clinically important difference (MCID) on an outcomes instrument and reporting satisfaction with surgical outcomes are not equivalent. We hypothesized that improvement exceeding the QuickDASH and PROMIS UE CAT MCID is associated with a greater likelihood of reporting satisfaction with ligament reconstruction tendon interposition (LRTI) treatment. Our secondary hypothesis was that a subset of patients failing to meet MCID would still be satisfied.

METHODS

Patients ≥1 year after LRTI at one academic tertiary institution were included. QuickDASH and UE CAT v1.2 scores were obtained before and after surgery. Postoperative satisfaction and levels of improvement in pain and function were also obtained.

RESULTS

A total of 93 patients completed the QuickDASH, and of those, 90 also completed the UE CAT. At a mean of 2.6 ± 1.0 years after surgery, QuickDASH and UE CAT score improvement exceeded the previously published MCID estimates of 8.8 and 4.8. Although 90% (84/93) of the patients reported satisfaction, only 85% (72/93) and 72% (59/90) achieved MCID on the QuickDASH and UE CAT, respectively. Using the MCID estimate of 8.8, 96% (72/75) of the patients meeting the MCID were satisfied with their treatment. Those failing to achieve MCID reported significantly less physical function and pain improvement; however, most were satisfied nonetheless (68% [13/19] for QuickDASH, 77% [23/30] for UE CAT).

CONCLUSIONS

Achieving published MCID thresholds on the QuickDASH and PROMIS UE CAT v1.2 was predictive of patients reporting general satisfaction with their LRTI outcome ≥1 year after surgery. Most patients failing to achieve MCID still reported satisfaction with their LRTI. Achieving MCID thresholds alone should not be used as a surrogate for patient satisfaction with their treatment. Patient satisfaction is a complicated construct that is potentially very different from that of high-quality care.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Arthroscopic all-inside ligament repair has similar or superior clinical outcomes compared to open repair for chronic ankle instability without concomitant intra-articular pathology at 5 years follow-up

PURPOSE

Open ligament repair is widely considered the gold standard treatment for chronic ankle instability. Nevertheless, arthroscopic treatment of ankle instability has gained popularity becoming the preferred technique for many surgeons. This study aimed to compare the clinical outcomes of all-inside arthroscopic versus open lateral ligament repair for chronic ankle instability at 5 years follow-up.

METHODS

Ninety consecutive patients were surgically treated for chronic ankle instability without concomitant intra-articular pathology observed on MRI: 41 patients [median age 28 (range 15-54) years] underwent an open lateral ligament repair (OLR); 49 patients [median age 30 (range 19-47) years] underwent an all-inside arthroscopic ligament repair (ALR). Functional outcomes using the Foot Functional Index (FFI), the American Orthopaedic Foot and Ankle Society (AOFAS) Hindfoot Score, and the Foot and Ankle Ability Measure-Sports Subscale (FAAM-SS) were assessed preoperatively and at the latest follow-up. At the latest follow-up, the satisfaction rate and complications were also recorded.

RESULTS

The mean follow-up was 58 ± 17.6 (range 47-81) months. In both groups FFI, AOFAS and FAAM-SS score significantly improved compared to preoperative values (p < 0.001). There was no statistically significant difference in postoperative outcomes between groups in the AOFAS (n.s) and FAAM-SS (n.s), but the FFI results were significantly better in the ALR group (p < 0.05). No major complications were reported in either group.

CONCLUSION

Open and arthroscopic ligament repair to treat chronic ankle instability without concomitant intra-articular pathology produced excellent comparable clinical outcomes at 5 years follow-up. The complications were minimal in both study groups with no significant differences in AOFAS and FAAM-SS scores. However, arthroscopic repair showed significantly better results on the FFI. Therefore, when treating chronic lateral ankle instability, surgeons should consider arthroscopic ligament repair.

LEVEL OF EVIDENCE

III.

Enthesis maturation in engineered ligaments is differentially driven by loads that mimic slow growth elongation and rapid cyclic muscle movement

Entheses are complex attachments that translate load between elastic-ligaments and stiff-bone via organizational and compositional gradients. Neither natural healing, repair, nor engineered replacements restore these gradients, contributing to high re-tear rates. Previously, we developed a culture system which guides ligament fibroblasts in high-density collagen gels to develop early postnatal-like entheses, however further maturation is needed. Mechanical cues, including slow growth elongation and cyclic muscle activity, are critical to enthesis development in vivo but these cues have not been widely explored in engineered entheses and their individual contribution to maturation is largely unknown. Our objective here was to investigate how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, individually drive enthesis maturation in our system so to shed light on the cues governing enthesis development, while further developing our tissue engineered replacements. Interestingly, we found these loads differentially drive organizational maturation, with slow stretch driving improvements in the interface/enthesis region, and cyclic load improving the ligament region. However, despite differentially affecting organization, both loads produced improvements to interface mechanics and zonal composition. This study provides insight into how mechanical cues differentially affect enthesis development, while producing some of the most organized engineered enthesis to date. STATEMENT OF SIGNIFICANCE: Entheses attach ligaments to bone and are critical to load transfer; however, entheses do not regenerate with repair or replacement, contributing to high re-tear rates. Mechanical cues are critical to enthesis development in vivo but their individual contribution to maturation is largely unknown and they have not been widely explored in engineered replacements. Here, using a novel culture system, we provide new insight into how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, differentially affect enthesis maturation in engineered ligament-to-bone tissues, ultimately producing some of the most organized entheses to date. This system is a promising platform to explore cues regulating enthesis formation so to produce functional engineered replacements and better drive regeneration following repair.

ATTR- and AFib amyloid - two different types of amyloid in the annular ligament of trigger finger

INTRODUCTION

Histological examination of tissue specimens obtained during surgical treatment of trigger finger frequently encountered unclassifiable amyloid deposits in the annular ligament. We systematically explored this unknown type by a comprehensive analysis using histology, immunohistochemistry, and quantitative mass spectrometry-based proteomics.

METHODS

205 tissue specimens of annular ligaments were obtained from 172 patients. Each specimen was studied by histology and immunohistochemistry. Tissue specimens obtained from ten patients with histology proven amyloid in annular ligament were analysed by label-free quantitative proteomics. Histological and immunohistochemical findings were correlated with patient demographics.

RESULTS

Amyloid was present as band like deposits along the surface of annular ligament, dot like or patchy deposits within the matrix. Immunohistochemistry identified ATTR amyloid in 92 specimens (mostly patchy in the matrix), while the band like deposits of 100 specimens remained unclassifiable. Proteomic profiles identified the unknown amyloid as most likely of fibrinogen origin. The complete cohort was re-examined by immunohistochemistry using a custom-made antibody and confirmed the presence of fibrinogen alpha-chain (FGA) in a hitherto unclassifiable type of amyloid in annular ligament.

CONCLUSION

Our study shows that two different types of amyloid affect the annular ligament, ATTR amyloid and AFib amyloid, with distinct demographic patient characteristics and histomorphological deposition patterns.