Aims. It has been established that mechanical stimulation benefits tendon-bone (T-B) healing, and macrophage phenotype can be regulated by mechanical cues; moreover, the interaction between macrophages and mesenchymal stem cells (MSCs) plays a fundamental role in tissue repair. This study aimed to investigate the role of macrophage-mediated MSC chondrogenesis in load-induced T-B healing in depth. Methods. C57BL/6 mice rotator cuff (RC) repair model was established to explore the effects of mechanical stimulation on macrophage polarization, transforming growth factor (TGF)-β1 generation, and MSC chondrogenesis within T-B
The
Despite extensive research aimed at improving surgical outcomes of
Obesity is associated with poor outcomes and increased risk of failure after rotator cuff (RC) repair surgery. The effect of diet-induced obesity (DIO) on
We hypothesised that diet-induced obesity (DIO) would result in inferior
The
Tendons and tendon-to-bone entheses don't usually regenerate after injury, and the hierarchical organization of such tissues makes them challenging sites of study for tissue engineers. In this study, we have tried a novel approach using miRNA and a bioactive bioink to stimulate the regeneration of the
Objectives. Rotator cuff tears are among the most frequent upper extremity injuries. Current treatment strategies do not address the poor quality of the muscle and tendon following chronic rotator cuff tears. Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor that activates many genes that are important in skeletal muscle regeneration. HIF-1α is inhibited under normal physiological conditions by the HIF prolyl 4-hydroxylases (PHDs). In this study, we used a pharmacological PHD inhibitor, GSK1120360A, to enhance the activity of HIF-1α following the repair of a chronic cuff tear, and measured muscle fibre contractility, fibrosis, gene expression, and
Re-rupture rates after rotator cuff repair remain high because of inadequate biological healing at the tendon-bone interface. Single-growth factor therapies to augment healing at the
Successful anterior cruciate ligament (ACL) reconstructions strive a firm ligament-bone integration. Therefore, the aim of this study was to address in more detail the
Abstract. Objectives. The scapholunate interosseous ligament (SLIL) has a unique C-shape following the arc of the scaphoid and lunate surfaces from distal dorsal around to distal volar. This ligament comprises of three subregions: dorsal, proximal and volar. The SLIL
Abstract. Objectives. The
Abstract. The lateral ligaments of the ankle composed of the anterior talofibular (ATFL), calcaneofibular (CFL) and posterior talofibular ligaments (PTFL), are amongst the most commonly injured ligaments of the human body. Although treatment methods have been explored exhaustively, healing outcomes remain poor with high rates of re-injury, chronic ankle instability and pain persisting. The introduction and application of tissue engineering methods may target poor healing outcomes and eliminate long-term complications, improving the overall quality of life of affected individuals. For any surgical procedure or tissue-engineered replacement to be successful, a comprehensive understanding of the complete anatomy of the native structure is essential. Knowledge of the dimensions of ligament footprints is vitally important for surgeons as it guides the placement of bone tunnels during repair. It is also imperative in tissue-engineered design as the creation of a successful replacement relies on a thorough understanding of the native anatomy and microanatomical structure. Several studies explore techniques to describe ligament footprints around the body, with limited studies describing in-depth footprint dimensions of the ATFL, CFL and PTFL. Techniques currently used to measure ligament footprints are complex and require resources which may not be readily available, therefore a new methodology may prove beneficial. Objectives. This study explores the application of a novel technique to assess the footprint of ankle ligaments through a straightforward inking method. This method aims to enhance surgical technique and contribute to the development of a tissue-engineered analogue based on real anatomical morphometric data. Methods. Cadaveric dissection of the ATFL, CFL and PTFL was performed on 12 unpaired fresh frozen ankles adhering to regulations of the Human Tissue (Scotland) Act. The ankle complex with attaching ligaments was immersed in methylene blue. Dissection of the proximal and distal entheses of each ligament was carried out to reveal the unstained ligament footprint. Images of each ligament footprint were taken, and the area, length and width of each footprint were assessed digitally. Results. The collective area of the proximal entheses of the ATFL, CFL and PTFL measures 142.11 ± 12.41mm2. The mean areas of the superior (SB) and inferior band (IB) of the distal
Objectives. After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the
The fibrocartilaginous
After surgical tendon repair, the tendon-to-bone
This study documents the gross and histologic structure of the infrapatellar plica, and fat pad, and adds to an earlier report to the COA. The important new findings are that the femoral attachment of the plica is an
Background. Re-attachment of tendon to bone is challenging with surgical repair failing in up to 90% of cases. Poor biological healing is common and characterised by the formation of weak scar tissue. Previous work has demonstrated that decellularised allogenic demineralised bone matrix (DBM) regenerates a physiologic
Tendons mainly consist of collagen in order to withstand high tensile forces. Compared to other, high turnover tissues, cellularity and vascularity in tendons are low. Thus, the natural healing process of tendons takes long and can be problematic. In case of injury to the
Rotator cuff tears are common, with failure rates of up to 94% for large and massive tears. 1. For such tears, reattachment of the musculotendinous unit back to bone is problematic, and any possible tendon-bone repair heals through scar tissue rather than the specially adapted native
Introduction: The intricate biomechanical function of the alar ligaments in the craniocervical articular complex has received considerable scientific attention. While allowing the greatest range of axial rotation of the entire spine with 40° to each side, definitive restraint at the extremes of motion by the alar ligaments is of vital importance. Detailed knowledge of the function of these ligaments is essential for comprehending the factors leading to potentially devastating instability. Methods: Bilateral alar ligaments including the bony entheses were removed from six adult cadavers aged 65–89 years within 48 hours of death. All specimens were judged to be free of abnormalities with the exception of non-specific degenerative changes. Dimensions of the alar ligaments were measured. Schematic multipla-nar reconstruction of axial atlanto-axial rotation was done in the transverse and frontal planes for the neutral position and for rotation to 30° and 40° in the neutral plane to assess schematic fibre elongation during axial rotation and to determine the change in the angle of insertion at the odontoid and condylar entheses. This was repeated with a 1mm descending translation of the occipital condyles at 30° and 3mm descending translation of the occipital condyles at 40° rotation. Results: The average diameter of the odontoid process measured in the sagittal plane was 10.6 mm (SD 1.1). The longest fibre length was measured from the posterior border of the odontoid
Surgical reattachment of torn rotator cuff tendons can lead to satisfactory clinical outcome but failures remain common. Ortho-R product is a freeze-dried formulation of chitosan (CS) that is solubilized in platelet-rich plasma (PRP) to form injectable implants. The purpose of the current pilot study was to determine Ortho-R implant acute residency, test safety of different implant doses, and assess efficacy over standard of care in a sheep model. The infraspinatus tendon (ISP) was detached and immediately repaired in 22 skeletally mature ewes. Repair was done with four suture anchors in a suture bridge configuration (n = 6 controls). Freeze-dried formulations containing 1% w/v chitosan (number average molar mass 35 kDa and degree of deacetylation 83%) with 1% w/v trehalose (as lyoprotectant) and 42.2 mM calcium chloride (as clot activator) were solubilized with autologous leukocyte-rich PRP and injected at the tendon-bone interface and on top of the repaired site (n = 6 with a 1 mL dose and n = 6 with a 2 mL dose). Acute implant residency was assessed histologically at 1 day (n = 2 with a 1 mL dose and n = 2 with a 2 mL dose). Outcome measures included MRI assessment at baseline, 6 weeks and 12 weeks, histopathology at 12 weeks and clinical pathology. MRI images and histological slides were scored by 2 blinded readers (veterinarian and human radiologist, and veterinarian pathologist) and averaged. The Generalized Linear Model task (SAS Enterprise Guide 7.1 and SAS 9.4) was used to compare the different groups with post-hoc analysis to test for pairwise differences. Ortho-R implants were detected near the
Aim. To determine the influence of tendo achilles (TA) rupture gap distance and location on clinical outcome managed with accelerated functional rehabilitation. Methods. Twenty six patients with acute complete TA ruptures underwent ultrasound (US) within a week of injury. Measurements included the distance of the rupture from the
The structure and extracellular matrix composition of the interface are complex and allow for a gradual mechanical stress transfer between tendons and bone. In this study, biphasic silk fibroin scaffolds designed to mimic the gradient in collagen molecule alignment present at the interface. The scaffolds had two different pore alignments: anisotropic at the tendon side and isotropic at the bone side. Total porosity ranged from 50–80% and the majority of pores were <100–300 µm. Young's modulus varied from 689–1322 kPa. In addition, human adMSC were cultured on the scaffolds to evaluate the effect of pore morphology on cell proliferation and gene expression. Biphasic scaffolds supported cell attachment and influenced cytoskeleton organization depending on pore alignment. In addition, the gene expression of tendon,
The
Purpose of the study: Irrespective of the technique used, the average rate of bone-tendon healing after rotator cuff repair is about 50% One of the reasons is the poor vitality of the tissues implicated in repair, particularly progressive destruction of the
Summary Statement. Demineralised bone matrix augmented tendon-bone fixations in the animal model show less scar tissue and an
We used demineralised bone matrix (DBM) to augment re-attachment of tendon to a metal prosthesis in an in vivo ovine model of reconstruction of the extensor mechanism at the knee. We hypothesised that augmentation of the tendon-implant interface with DBM would enhance the functional and histological outcomes as compared with previously reported control reconstructions without DBM. Function was assessed at six and 12 weeks postoperatively, and histological examination was undertaken at 12 weeks. A significant increase of 23.5% was observed in functional weight-bearing at six weeks in the DBM-augmented group compared with non-augmented controls (p = 0.004). By 12 weeks augmentation with DBM resulted in regeneration of a more direct-type
Cell sheets are manufactured from a high-density cell layer stabilized by its own freshly produced extracellular matrix (ECM). They could serve as versatile scaffolds for tissue repair. Unfortunately, their production often remains time-consuming requiring weeks of culturing. Ligament cell sheets are so far barely available. Regarding musculoskeletal tissues exposed to high repetitive biomechanical forces, the stability of cell sheets is insufficient. It could help to combine them with a biomechanical competent scaffold e.g. produced by an embroidering technique. Hence, we wanted to (1) develop a very rapid strategy to produce ACL ligamentocyte sheets within 24 h by using a thermoresponsive polymer surface, (2) use the sheets for scaffold seeding and (3) reflect the fibrocartilaginous transition zone of an ACL
We used an in vivo model to assess the use of an autogenous cancellous bone block and marrow graft for augmenting tendon reattachment to metallic implants. We hypothesised that augmentation of the tendon-implant interface with a bone block would enable retention of the graft on the implant surface, enhance biological integration, and result in more consistent functional outcomes compared with previously reported morcellised graft augmentation techniques. A significant improvement in functional weight-bearing was observed between six and 12 weeks. The significant increase in ground reaction force through the operated limb between six and 12 weeks was greater than that reported previously with morcellised graft augmented reconstructions. Histological appearance and collagen fibre orientation with bone block augmentation more closely resembled that of an intact
Research in to tendon-bone healing techniques focus on increasing bone growth at the interface such as cell or growth factor (e.g. BMP-2) augmentation. Demineralised bone matrix (DBM) is osseoinductive and is in use clinically. Hypothesis: DBM augmentation of a healing tendon-bone interface will result in improved function at 3, 6, 9 and 12 weeks, and a morphology that more closely resembles that of a normal
Due to unsatisfactory results and reported drawbacks of anterior cruciate ligament (ACL) reconstruction new regenerative approaches based on tissue-engineering strategies are currently under investigation. It was the purpose of this study to determine if a novel silk fiber-based ACL scaffold is able to initiate osteointegration in the femoral and tibial bone tunnels under in vivo conditions. Furthermore we tested if the osteointegration process will be improved by intraoperatively seeding the scaffolds with the autologous stromal vascular fraction, an adipose-derived, stem cell-rich isolate from knee fat pads. In this controlled laboratory study, 33 sheep underwent ACL resection and were then randomly assigned to 2 experimental groups: ACL reconstruction with a scaffold alone and ACL reconstruction with a cell-seeded scaffold. Half of the sheep in each group were randomly chosen and euthanized 6 months after surgery and the other half at 12 months. To analyze the integration of the silk-based scaffold in the femoral and tibial bone tunnels, hard tissue histology and micro-computed tomography measurements were performed. The histological workup showed that in all treatment groups, with or without the application of the autologous stromal vascular fraction, an interzone of collagen fibers had formed between bone and silk-based graft. This collagen-fiber continuity partly consisted of Sharpey fibers, comparable with tendon-bone healing known for autografts and allografts. Insertion sites were more broad based at 6 months and more concentrated on the slightly protruding, bony knoblike structures at 12 months. Histologically, no differences between the treatment groups were detectable. Analysis of micro-computed tomography measurements revealed a significantly higher tissue density for the cell-seeded scaffold group as compared with the scaffold-alone group in the tibial but not femoral bone tunnel after 12 months of implantation. The novel silk fiber-based scaffold for ACL regeneration demonstrated integration into the bone tunnels via the formation of a fibrous interzone similar to allografts and autografts. Histologically, additional cell seeding did not enhance osteointegration. No significant differences between 6 and 12 months could be detected. After 12 months, there was still a considerable amount of silk present, and a longer observation period is necessary to see if a true ligament-bone
Introduction: Functional outcome following proximal tibial replacement can be impaired by extensor mechanism inefficiency. Current methods used to re-attach the patellar tendon result in varied levels of extensor function. Successful attachment of the patellar tendon requires initial mechanical stability and long-term biological fixation. We have employed a prosthesis, to model patellar tendon re-attachment, to test the hypothesis that biological augmentation of an implant which can provide sufficient mechanical integrity will allow a tendon-implant interface to develop that is similar in function and morphology to a normal tendon-bone interface. Methods: The right patellar tendon in 24 Skeletally mature Friesland ewes was transfixed between the interlocking spikes of a hydroxyapatite-coated, customized tendon clamp to simulate patellar tendon re-attachment to a proximal tibial replacement. In 12 animals (Autograft group) the clamp attachment was augmented with autologous cancellous bone and marrow graft harvested from the ipsilateral iliac crest at the time of surgery, whilst the remaining animals (HA group) served as un-supplemented controls. Functional outcome was assessed using force plate measurements and two-dimensional optical kinematic gait analysis. Animals were euthanised at 6 and 12 weeks. The specimens were harvested, processed for histology and examined using light microscopy. Results: The clamp device provided sufficient mechanical fixation of the patellar tendon to allow immediate weight bearing. Gait analysis showed that the range of movement of the stifle (knee) joint was not compromised by the surgical intervention at 6 or 12 weeks post-operation. An extensor lag observed at 6 weeks in both the Autograft and HA group was seen to fully recover by 12 weeks post-operation. There was a significant increase in functional weight bearing through the operated limb of the Autograft group animals between 6 and 12 weeks, which was not observed in the HA group. The tendon-implant interface in the HA group animals showed a fibrous tissue encapsulation of the HA coated surface, with collagen fibrils running parallel to the implant surface. In the Autograft group at 6 weeks post-operation a soft tissue – bone – HA interface had developed, similar in morphology to that of an indirect-type
We developed an in vivo model of the attachment of a patellar tendon to a metal implant to simulate the reconstruction of an extensor mechanism after replacement of the proximal tibia. In 24 ewes, the patellar tendon was attached to a hydroxyapatite (HA)-coated titanium prosthesis. In 12, the interface was augmented with autograft containing cancellous bone and marrow. In the remaining ewes, the interface was not grafted. Kinematic gait analysis showed nearly normal function of the joint by 12 weeks. Force-plate assessment showed a significant increase in functional weight-bearing in the grafted animals (p = 0.043). The tendon-implant interface showed that without graft, encapsulation of fibrous tissue occurred. With autograft, a developing tendon-bone-HA-implant interface was observed at six weeks and by 12 weeks a layered tendon-fibrocartilage-bone interface was seen which was similar to a direct-type
This study aimed to explore the relationship between the geometry of the tuberosity located superior to the Achilles tendon
Summary. Our study shows that a tendon rupture can be successfully augmented with Demineralised Cortical Bone (DCB) giving initial appropriate mechanical strength suitable for in vivo use providing the biological reactions to the graft are favourable. Introduction. Treatment of tendon and ligament injuries remains challenging; the aim is to find a biocompatible substance with mechanical and structural properties that replicate those of normal tendon and ligament. Because of its structural and mechanical properties, we proposed that DCB can be used in repair of tendon and ligament as well as regeneration of the
Tendon is a bradytrophic and hypovascular tissue, hence, healing remains a major challenge. The molecular key events involved in successful repair have to be unravelled to develop novel strategies that reduce the risk of unfavourable outcomes such as non-healing, adhesion formation, and scarring. This review will consider the diverse pathophysiological features of tendon-derived cells that lead to failed healing, including misrouted differentiation (e.g. de- or transdifferentiation) and premature cell senescence, as well as the loss of functional progenitors. Many of these features can be attributed to disturbed cell-extracellular matrix (ECM) or unbalanced soluble mediators involving not only resident tendon cells, but also the cross-talk with immigrating immune cell populations. Unrestrained post-traumatic inflammation could hinder successful healing. Pro-angiogenic mediators trigger hypervascularization and lead to persistence of an immature repair tissue, which does not provide sufficient mechano-competence. Tendon repair tissue needs to achieve an ECM composition, structure, strength, and stiffness that resembles the undamaged highly hierarchically ordered tendon ECM. Adequate mechano-sensation and -transduction by tendon cells orchestrate ECM synthesis, stabilization by cross-linking, and remodelling as a prerequisite for the adaptation to the increased mechanical challenges during healing. Lastly, this review will discuss, from the cell biological point of view, possible optimization strategies for augmenting Achilles tendon (AT) healing outcomes, including adapted mechanostimulation and novel approaches by restraining neoangiogenesis, modifying stem cell niche parameters, tissue engineering, the modulation of the inflammatory cells, and the application of stimulatory factors. Cite this article:
Hypertrophy of lumbar articular facets and dorsal joint capsule are well documented in degenerative instability, the molecular changes occurring in the extracellular matrix (ECM) are however unknown. The L4/L5 posterior articular complex was removed from seven individuals undergoing fusion for degenerative instability. After methanol fixation and decalcification in EDTA, specimens were cryosectioned at 12 μm and immunolabelled with monoclonal antibodies for collagen types I, II, III, V and VI; chondroitin-4 and 6 sulphates; dermatan and keratan sulphate; versican, tenascin, aggrecan and link-protein. Antibody binding was detected using the Vectastain ABC ‘Elite’ kit. Labelling patterns were compared to corresponding healthy specimens examined previously. In comparison, the degenerative capsule was more dense and hypertrophied and the
Introduction. Kager's fat pad (KFP) is located in Kager's triangle between the Achilles tendon (AT), the superior cortex of the calcaneus and Flexor Hallucis Longus (FHL) muscle & tendon. Although the biomechanical functions of KFP are not yet fully understood, a number of studies suggested that KFP performs important biomechanical roles including assisting in the dynamic lubrication of the AT subtendinous area, protection of AT vascular supply, and load and stress distribution within the retrocalcaneal bursa space. Similar to the knee meniscus, KFP has become under increasing investigations since strong indications were found that it serves more than just a space filler. Both KFP and the knee meniscus are anchored to their surrounding tissues via fibrous attachments, they can be found in encapsulated (or ‘air tight’) regions, lined by synovial membranes, and they both slide within their motion ranges. The protruding wedge (PW) of KFP was observed to slide in and out of the retrocalcaneal bursal space during ankle plantarflexion and dorsiflexion, respectively. In-vitro studies of KFP suggest that it reduces the load by 39%, which is similar to that of the knee meniscus (30%-70% of the load applied on the knee joint). This study investigated the in-vivo load bearing functionality of KFP. Materials and Methods. The ankles of 5 volunteers (3 males, 2 females, Age 20-28, BMI 21-26) were scanned using a 0.2T MRI scanner at ankle plantarflexion and neutral positions. The ankles of 2 of those volunteers were later scanned using a 3T MRI scanner for higher accuracy. The areas and volumes of KFP were measured using Reconstruct¯ 3D modelling software. The hind foot of the volunteers were scanned using dynamic ultrasound to measure in-vivo real time shape changes of PW. Results. The cross sectional area of KFP in the AT midline saggital plane increased on average by 10% when ankles were changed from neutral to plantarflexion positions. The volume of KFP showed less variation than cross sectional areas (3.9% variation in volume). Previous studies showed the cross sectional area of the knee meniscus changes by 9.8% during loading, or flexing the knee by 90°, and its volume was reduced by 3.5%-5.9% (medial and lateral menisci respectively). Ultrasound imaging showed that PW's thickness decreased during dorsiflexion compared to plantarflexion by an average of 1mm and a hysteresis was found between the location of PW's tip and the insertion angle of AT, suggesting the fibrous tip of PW bears load during dorsiflexion. Discussions and conclusions. The similarities in results between the knee meniscus (literature review) and KFP supports hypotheses that KFP assists in reducing the load applied at the AT
Adenosine, lidocaine, and Mg2+ (ALM) therapy exerts differential immuno-inflammatory responses in males and females early after anterior cruciate ligament (ACL) reconstruction (ACLR). Our aim was to investigate sex-specific effects of ALM therapy on joint tissue repair and recovery 28 days after surgery. Male (n = 21) and female (n = 21) adult Sprague-Dawley rats were randomly divided into ALM or Saline control treatment groups. Three days after ACL rupture, animals underwent ACLR. An ALM or saline intravenous infusion was commenced prior to skin incision, and continued for one hour. An intra-articular bolus of ALM or saline was also administered prior to skin closure. Animals were monitored to 28 days, and joint function, pain, inflammatory markers, histopathology, and tissue repair markers were assessed.Aims
Methods
Mechanical stimulation is a key factor in the development and healing of tendon-bone insertion. Treadmill training is an important rehabilitation treatment. This study aims to investigate the benefits of treadmill training initiated on postoperative day 7 for tendon-bone insertion healing. A tendon-bone insertion injury healing model was established in 92 C57BL/6 male mice. All mice were divided into control and training groups by random digital table method. The control group mice had full free activity in the cage, and the training group mice started the treadmill training on postoperative day 7. The quality of tendon-bone insertion healing was evaluated by histology, immunohistochemistry, reverse transcription quantitative polymerase chain reaction, Western blotting, micro-CT, micro-MRI, open field tests, and CatWalk gait and biomechanical assessments.Aims
Methods
Tendon detachment from its bony insertion is one of the most frequent injuries occurring in the musculoskeletal interface, constituting an unmet challenge in orthopaedics. Tendon-to-bone integration occurs at the
Subscapularis repair and integrity after a primary total shoulder arthroplasty is critical for successful outcomes. One should be familiar with the 3 basic takedown and repair techniques commonly utilised. Subscapularis repair after reverse shoulder arthroplasty is not as critical and in some cases may be detrimental to return of external rotation strength and motion. Subscapularis tenotomy: The tendon is incised approximately 1 cm from the lesser tuberosity and an oblique incision is created from proximal lateral to distal medial stopping at the sentinel vessels. A combination of tendon-to-tendon figure of 8 sutures. Lesser tuberosity osteotomy: This approach is helpful not only in obtaining a bone-to-bone healing, but also in the exposure. Osteotomies range from a fleck of bone in patients with minimal deformity, to a C-shaped osteotomy including part of the head which facilitates exposure of the posterior glenoid. Despite an ability to document radiographic healing of the lesser tuberosity fragment, this technique does not prevent fatty infiltration of the subscapularis. Subscapularis Peel: This repair requires tendon healing to bone and probably incomplete, in most cases, reconstitution of a normal
Injuries to the quadriceps muscle group are common in athletes performing high-speed running and kicking sports. The complex anatomy of the rectus femoris puts it at greatest risk of injury. There is variability in prognosis in the literature, with reinjury rates as high as 67% in the severe graded proximal tear. Studies have highlighted that athletes can reinjure after nonoperative management, and some benefit may be derived from surgical repair to restore function and return to sport (RTS). This injury is potentially career-threatening in the elite-level athlete, and we aim to highlight the key recent literature on interventions to restore strength and function to allow early RTS while reducing the risk of injury recurrence. This article reviews the optimal diagnostic strategies and classification of quadriceps injuries. We highlight the unique anatomy of each injury on MRI and the outcomes of both nonoperative and operative treatment, providing an evidence-based management framework for athletes. Cite this article:
In this histological study, the canine infraspinatus tendons were repaired to different bone surfaces: 1, a tendon end adjacent to the insertion: 2, a calcified fibro-cartilage layer; 3, a cancellous surface. Tendon repair to tendon ends restored the four-layered
Introduction. Tendon injuries remain challenging, secondary healing and prolonged immobilisation result in suboptimal outcome. Previous study by our group showed that demineralised bone matrix (DBM) can result in faster healing of a tendon
Aim. To determine the effects of knee and ankle position on tendo Achilles (TA) gap distance in patients with acute rupture using ultrasound. Methods. Twenty seven patients with twenty-eight acute complete TA ruptures confirmed on ultrasound were recruited within a week of injury. The mean age at presentation was 42 years (range 23-80 years). Ultrasound measurements included location of the rupture and the gap distance between the superficial tendon edges with the ankle in neutral and knee extended. The gap distance was sequentially measured with the foot in maximum equinus and 0°, 30°, 60° and 90° of knee flexion. Results. The mean distance of the rupture from the
Introduction: In a previous study (. Hayes et al., 2007. )we reported that novel chondroitin sulphate (CS) sulphation motifs on cell-associated proteoglycans (PGs) may be putative biomarkers of progenitor/stem cell sub-populations resident within the superficial zone of articular cartilage (. Dowthwaite et al., 2005. ). In this study, using the same panel of antibodies, we examine the distribution of novel CS sulphation epitopes in a more clinically relevant model – the developing human knee joint. Methods: Twelve-14 week human foetal knee joint rudiments were processed into paraffin wax then de-waxed and immunoperoxidase-stained with mAbs 3B3(−), 7D4 and 4C3 using the Vector Universal Elite kit with Nova Red, Mayers Haematoxylin, mounted under coverslips and then photographed. Results: All three CS sulphation motif epitopes localised prominently at sites of incipient articular cartilage formation at a stage before there was any histological evidence of secondary ossification at the epiphysis. Interestingly, these CS epitopes were also detectable in very defined regions within the perichondrium; growth plate; the fibrocartilage of both meniscus and
In the treatment of ligament injuries there has been much interest in the restoration of the actual ligament anatomy, and the extent to which the original
In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading. Torque-rotation curves were obtained from nine cadaveric hips to define the rotational restraint contributions of the capsular ligaments in 36 positions. A ligament model was developed to determine the line-of-action and effective moment arms of the medial/lateral iliofemoral, ischiofemoral, and pubofemoral ligaments in all positions. The functioning ligament forces and stiffness were determined at 5 Nm rotational restraint. In each position, the contribution of engaged capsular ligaments to the joint reaction force was used to evaluate the net force vector generated by the capsule.Aims
Methods