Flexor Tendon Research Articles

Comparison of Outcome Between Early and Delayed Repair of Flexor Tendons

Comparison of Outcome Between Early and Delayed Repair of Flexor Tendons

Mesenchymal Stromal Cells for the Enhancement of Surgical Flexor Tendon Repair in Animal Models: A Systematic Review and Meta-Analysis.

Flexor tendon lacerations are primarily treated by surgical repair. Limited intrinsic healing ability means the repair site can remain weak. Furthermore, adhesion formation may reduce range of motion post-operatively. Mesenchymal stromal cells (MSCs) have been trialled for repair and regeneration of multiple musculoskeletal structures. Our goal was to determine the efficacy of MSCs in enhancing the biomechanical properties of surgically repaired flexor tendons. A PRISMA systematic review was conducted using four databases (PubMed, Ovid, Web of Science, and CINAHL) to identify studies using MSCs to augment surgical repair of flexor tendon injuries in animals compared to surgical repair alone. Nine studies were included, which investigated either bone marrow- or adipose-derived MSCs. Results of biomechanical testing were extracted and meta-analyses were performed regarding the maximum load, friction and properties relating to viscoelastic behaviour. There was no significant difference in maximum load at final follow-up. However, friction, a surrogate measure of adhesions, was significantly reduced following the application of MSCs (p = 0.04). Other properties showed variable results and dissipation of the therapeutic benefits of MSCs over time. In conclusion, MSCs reduce adhesion formation following tendon injury. This may result from their immunomodulatory function, dampening the inflammatory response. However, this may come at the cost of favourable healing which will restore the tendon's viscoelastic properties. The short duration of some improvements may reflect MSCs' limited survival or poor retention. Further investigation is needed to clarify the effect of MSC therapy and optimise its duration of action.

The effect of the number of strands and knot throws of core suture techniques on the mechanical properties of the repaired flexor tendon.

Flexor tendon injury is a common hand trauma that requires surgical repair. The objective was to compare the repaired strength and gliding resistance with a varied number of repair strands and of square knots using a two-strand-overhand locking (TSOL) knot. First, isolated suture loops with different number of suture strands and number of closing knots were compared in mechanical strength and failure mode. Then, 90 flexor digitorum profundus (FDP) tendons from turkey digits were used for the tendon repair experiment. Both phases followed a similar 3 × 3 matrix comparing the knot type including TSOL+1SK (square knot), TSOL+2SK, and TSOL+3 SK and repair techniques including two-, four-, and six-strand repairs techniques respectively. The repaired tendons were tested for tendon resistance against pulley (friction), maximum force, force at 2 mm displacement, stiffness, and failure mode. Increasing the number of strands and closing square knots increases the tensile strength and stiffness of flexor tendon repairs and isolated suture loops without a significant effect on tendon friction. An increase in the number of square knots have shown increased strength only in Pennington repair, which correlated with the increased number of knot unraveling, a weak knot failure model. Our data demonstrated that increasing the number of strands is effective for improving the overall strength of tendon repair. When a two-strand repair is chosen, increasing knot number can improve repair strength. However, the number of knots appears not affecting repair strength in six-strand repair technique.

The major league baseball pitch clock: First year analysis of pitcher injuries

Recently, star pitchers in Major League Baseball (MLB) have faced devastating elbow injuries, causing some to question whether implementation of the MLB pitch clock during the 2023 season has led to a higher rate of elbow injuries among pitchers. This study aims to determine if implementation of the MLB pitch clock in the 2023 MLB season affected the injury rate in pitchers. Injury data was collected for the 2021, 2022, and 2023 MLB seasons using the fangraphs.com injury database. Incidence rate ratio was calculated to compare the injury rate for the 2023 season to the 2021 and 2022 seasons. A z-test for proportions was used to determine significance levels. The 2023 season showed a decrease in the rate of the total number of injuries when compared to the 2021 (P=0.01) and 2022 (P=0.02) seasons. There was no statistical difference in the rate of Tommy John Surgery, Flexor Tendon Injuries, or other cause elbow injuries. Following implementation of the MLB pitch clock during the 2023 season, the total number of injuries decreased, but there was no change in the rate of elbow injuries in pitchers compared with the 2021 and 2022 MLB seasons. Future studies are needed to determine if the pitch clock has a longitudinal effect on injuries.

Prognostic value of power doppler ultrasonography for equine superficial digital flexor tendon injury in thoroughbred racehorses

The potential value of hypervascularity detected with power Doppler ultrasonography (PDU) within equine superficial digital flexor tendon (SDFT) as a prognostic factor of SDFT injury is not clear. The purpose of this study was to test the hypothesis that hypervascularity within SDFT is one of the risk factors for subsequent severe SDFT injury and to evaluate the prognostic value. A prospective cohort study of 97 Thoroughbred racehorses without any clinical signs of SDFT injury was conducted. Six variables of age, body weight, sex, the cross-sectional area of SDFT, PDU signal within SDFT and experience of steeplechase were assessed for the possibility of risk factors of subsequent SDFT injury in follow-up period of 1 year. Multivariable logistic regression analyses were used for assessment of the odds ratios (ORs) and 95 % confidence intervals (CIs) of SDFT injury. Multivariable logistic regression analysis revealed that the PDU signal within SDFT was a risk factor for the development of SDFT injury in follow-up period (P = 0.017). The adjusted OR of SDFT injury was significantly higher in PDU positive group than in PDU negative group (OR 3.17, 95 % CIs 1.20–8.35). Although further studies are required, these results would be useful for early detection and/or prevention of development for clinical severe SDFT injury.

Comparison of Treatment Outcomes of Different Immobilized Finger Positions After Repair of Flexor Tendon Rupture in Zones I and II: A Nonrandomized Controlled Trial With Historical Control Group.

Introduction The position of finger immobilization after flexor tendon rupture repair is changed to the extended position to prevent flexion contracture of the interphalangeal (IP) joint. However, in Strickland's assessment, We believe that a reduction in TAF (total active flexion) affects the outcome and that extension fixation is not necessarily the primary focus.For example, there are management methods that swap the fixed position between day and night. It is assumed that some effect is sought by placing the fingers in the flexed position. That is, the method of fixation is currently selected at individual facilities through twists and turns; however,the indications and criteria for selecting finger fixation positions are ambiguous, and they are apparently subject to the experience of therapists. This study aimed to characterize follow-up outcomes of flexion and extension fixation after zones I and II flexor tendon rupture repair. Methods This nonrandomized controlled trial with historical controls included 25 patients with flexor tendon ruptures of 30 fingers. The flexion fixation group consisted of 12 patients (n=16 fingers) and the extension fixation group consisted of 13 patients (n=14 fingers). The group with flexion fixation comprised patients who slept with their injured fingers in the flexed position (intervention group). The group with extension was retrospectively selected between April 2017 and March 2019, who slept with their injured finger in the extended position (historical control group). Strickland assessments of the range of motion (ROM) of each joint at the conclusion of hand therapy, the ratio of total active motion of the repaired, to the healthy finger (%TAF), and IP joint extension limitation angles were compared using Mann-Whitney U tests. Ratios of excellent and good ratings based on the Strickland assessment were compared using Fisher exact tests. Result The results of the Strickland assessment showed excellent or goodoutcomes for 22(73%) of 30 fingers, which was in line with our previous findings. Strickland ratings of excellent were achieved in seven (44%) of 16 fingers and four (28%) of 14 fingers in the groups with flexion and extension fixation, respectively. The outcomes for two (22%) of 16 fingers and seven (78%) of 14 fingers in the groups with flexion and extension fixation were, respectively, rated asgood. The proportion of patients rated as excellent was significantly higher in the group with flexionthan extension fixation (p=0.040). The %TAF and the active flexion angle of the distal interphalangeal (DIP) joint were higher in the group with flexionthan extension fixation (p=0008 and p=0.025, respectively). Furthermore, the total angle of the IP joint limit of extension did not significantly differ between the groups. Conclusion Flexion fixation after flexor tendon rupture achieved an excellent Strickland rating and was more effective than extension fixation, especially in terms of the active flexion ROM of the DIP joint. Flexion fixation might be an alternative to extension fixation because the range of flexion should be greater and might provide a range of finger extension motion equivalent to that of extension fixation.

Health of Polo Horses.

This literature review analyzes the historical development of polo, its organizational structure, the course of the game, as well as the breeding, rearing, and training practices of polo horses. Frequently occurring ailments, such as musculoskeletal injuries, respiratory diseases, and internal illnesses, are highlighted. Lameness is a major problem, with injuries to the superficial digital flexor tendon being the most common cause. Other notable diseases include exercise-induced pulmonary hemorrhage (EIPH), myositis, rhabdomyolysis, and equine infectious anemia (EIA). To ensure the welfare of polo horses, effective prevention and management strategies are crucial. These include proper training, the adaptation of the ground surface, appropriate shoeing, and compliance with animal welfare guidelines and association rules. Collaboration between associations, players, organizers, and veterinarians is crucial. Promoting responsible management practices and raising awareness among stakeholders can help ensure that polo continues to thrive while maintaining high animal welfare standards.

Flexor Tendon Continuity and Negative X-ray: The "Combo" Negative Features in Finger Subamputation.

Background: The subamputation of fingers with vascular compromise presents a surgical challenge. Although tissue continuity may be considered a favourable prognostic element, in our experience, we noticed that there is not always a direct correlation between soft tissue involvement, radiographic appearance and final outcome. Methods: We included, in our study, all cases of vascular pedicle injury in which finger salvage was attempted with microsurgical revascularisation. Exclusion criteria were: integrity of both vascular pedicles, pedicle lesion without global circulatory compromise and patients treated immediately with amputation. Results: Between May 2018 and July 2023, 27 male patients with finger subamputation injuries were treated at our institution. In 11 cases of injured fingers, the only intact tissue was the flexor digitorum profundus (FDP) or flexor pollicis longus (FPL). Our global failure rate was 49%; whereas, in the subgroup of the 11 cases with continuity of the FDP or FPL, the failure rate rose to 73% and when the fingers showed flexor tendon integrity and radiographs demonstrated minimal bone damage, revascularisation failure was observed in all cases (100%). Conclusions: The results of the study show that subamputations with devascularisation, clinically presented with the combination of flexor tendon as the only element of tissue continuity and dislocation or minimal bone/articular injury, have a worse prognosis because of their trauma mechanism. We propose to add them to the Kay-Adani Classification as a subset of the poorest prognostic injuries group (III), to help surgeons to make decisions about the management of subamputation finger injuries.

Computed tomographic evaluation of the proximity of needles placed for perineural anesthesia of the palmar digital nerves to synovial structures in the foot: an ex vivo study.

Potential synovial penetration following palmar digital nerve blocks has not been investigated. To evaluate the proximity of needles placed for palmar digital nerve blocks to nearby synovial structures using computed tomography (CT). Descriptive observational study. In 18 cadaver forelimbs, sequential injection of the navicular bursa (NB), distal interphalangeal joint (DIPJ) and digital flexor tendon sheath (DFTS) was performed using 3, 5 and 10 mL diluted radiodense contrast medium, respectively. After each synovial injection, 25 gage needles were placed over the palmar digital nerves at the proximal aspect of the ungular cartilages (distal injections) and 1 cm further proximally (proximal injections), and CT examination was performed. Subsequently, needles were removed, and the synovial structures further distended with the same volume as for the first injection. Perineural needle placement and image acquisition were repeated. The distance between the needle tip and adjacent synovial structures was measured (mm) in reconstructed images. Results were analyzed in separate general linear mixed models, to determine the effect of needle position and synovial distension on the distance from the tip of the needle to the NB, DFTS and DIPJ. Synovial penetration was confirmed following 12/420 (3%) needle placements (NB n = 5, 1 after proximal and 4 after distal injections; DIPJ n = 2, DFTS n = 2, NB or DIPJ n = 3, all after distal injections). The mean distance from the needle tip to the NB and DIPJ was significantly smaller after the second distension (NB: p = 0.025; DIPJ: p < 0.001) and with the distal needle placements (NB: p < 0.001; DIPJ: p < 0.001). For the DFTS, the distance from the needle tip was significantly smaller with the proximal needle placements (p = 0.001). Ex-vivo study. There is a small risk of synovial penetration when performing palmar digital nerve blocks, especially when distension of adjacent synovial structures is present.

The median nerve´s system of connective tissue distal to the pronator teres to the carpal tunnel

BackgroundConnective tissue serves a role beyond mere spatial filling. Furthermore, there is increasing evidence that connective tissue plays an important role in the pathogenesis of conditions such as carpal tunnel syndrome (CTS). According to our hypothesis, the median nerve (MN) is surrounded by a system of connective tissue distal to the pronator teres and extending up to, and including, the carpal tunnel. MethodsTo visualize the connective tissue surrounding the median nerve, we dissected the forearms of 15 body donors from pronator teres to the carpal tunnel, created plastination slices stained with Periodic Acid-Schiff (PAS), and injected ink into the seen spaces. We verified our findings with a segmentational analysis of radiological data of 10 healthy individuals. ResultsWe macroscopically describe the median nerve´s system of connective tissue (MC) distal to the pronator teres and up to and including the carpal tunnel. This system creates, connects, and separates spaces. At least from the pronator teres to the carpal tunnel it also creates subspaces from proximal to distal. For the MC, we established a mean cross-sectional area of 153.1 mm2 (SD=37.15) in the carpal tunnel. The median nerve consistently resides at the center of this MC, which further connects to flexor muscles of the forearm, and to the radius bone. In the carpal tunnel, the MC creates subspaces inside. There, it also acts as the outermost internal layer enveloping flexor tendons, and the MN. DiscussionThe term MC does not negate but orders the existence of other “connectives”, like subsynovial connective tissue, endo-, epi- or perineuria, epimysia, periostea, or peritendinea, to a hierarchy related to the median nerve. Diseases of the MN are common. Knowing the anatomy of the MC and how it relates to MN function may help clinicians recognize and understand conditions like CTS.

Mapping Origins of Tendons on the Medial Epicondyle to Improve Treatment of Medial Epicondylitis: Anatomical Study

Medial epicondylitis is a tendinosis found commonly in throwing and golfing athletes. Although there are choices for nonsurgical treatments, when these fail, surgical intervention can be considered. When surgical treatment is performed, the objective is to debride the diseased tissue from the epicondyle. The purpose of this study was to clarify the locations and size of the common flexor tendons and medial collateral ligament (MCL) relative to each other and to the posterior ridge of the medial epicondyle. The common flexor tendons and MCL were dissected and reflected their origin on the medial epicondyle in six cadaver elbows. Measurements were taken from the posterior and distal ridges of the medial epicondyle with respect to the humerus. Each origin was also measured for its height and width. The flexor carpi ulnaris origin starts at a mean of 4.2 mm from the posterior ridge of the medial epicondyle and extends anteriorly an average of 4.8 mm. The flexor carpi radialis starts at a mean of 4.2 mm from the posterior ridge and extends anteriorly an average of 7.4 mm. The pronator teres begins at a mean of 4.6 mm from the posterior ridge and extends an average of 5.7 mm anteriorly. The MCL starts at an average of 10.4 mm from the posterior ridge and extends 5.2 mm anteriorly. The measurements found have allowed the creation of a map of the specific common flexor tendon origins and their sizes on the medial epicondyle, as well as their position relative to the MCL. A surgeon may debride 1 cm anteriorly from the posterior ridge of the medial epicondyle to safely address the affected tissues and ensure the safety and integrity of the MCL.

Outcome of tenoscopically guided palmar/plantar annular ligament desmotomy for the treatment of palmar/plantar annular ligament constriction without concurrent intrathecal soft-tissue injury in a UK horse population.

To determine the outcome of tenoscopically guided palmar/plantar annular ligament (PAL) desmotomy to treat PAL constriction without concurrent intrathecal soft-tissue injury, notably of the digital flexor tendons and manica flexoria. Retrospective multicenter cohort study. Sixty-five horses. Horses from four UK equine hospitals, with digital flexor tendon sheath (DFTS) tenosynovitis, which underwent tenoscopically guided PAL desmotomy for treatment of PAL constriction between 2017 and 2022 were included. All horses had lameness isolated to the DFTS/PAL, and PAL constriction was diagnosed tenoscopically when there was difficulty maneuvering the endoscope into or through the fetlock canal. Horses with tearing of the digital flexor tendons and/or manica flexoria, or any other intrathecal pathology, were excluded. Follow up was via structured telephone questionnaire. Follow up (median 25 months) was available for 61 horses with cobs and ponies predominating. Forty-two returned to their previous level of work, or a higher level, postoperatively and 50 owners were satisfied with the outcome of surgery. Eleven horses returned to lower level exercise, and six were retired/euthanized as they did not regain soundness. Fifty-two horses achieved soundness (median 3 months postoperatively). Tenoscopically guided PAL desmotomy for the treatment of PAL constriction in the absence of intrathecal soft tissue injury had a good prognosis for return to previous levels of exercise in a UK horse population. The prognosis for horses undergoing tenoscopically guided PAL desmotomy to treat PAL constriction in the absence of intrathecal injury is better than previously described. Cobs and ponies seem to be predisposed to PAL constrictionin agreement with the previous literature.

Four-Strand Modified Kessler versus Cruciate Technique for Repair of Zone Two Flexor Tendon Injuries: A Randomized Controlled Trial

Four-Strand Modified Kessler versus Cruciate Technique for Repair of Zone Two Flexor Tendon Injuries: A Randomized Controlled Trial

P.059 Weill-Marchesani Syndrome – a rare etiology for bilateral carpal tunnel syndrome in children

Background: Carpal tunnel syndrome (CTS) is less common in children but can be associated with significant disability. Pediatric CTS can be associated with an underlying disorder most commonly storage disorders including mucopolysaccharidoses (MPS). We report a patient with bilateral severe CTS secondary to Weill-Marchesani Syndrome (WMS). Methods: A retrospective chart review was completed. Results: A five-year-old female presented with a three-year history of bilateral thumb weakness and insensate digits two and three. Nerve conduction studies (NCS) revealed severe bilateral CTS. She underwent bilateral carpal tunnel release (CTR). Unfortunately, post-operative NCS was unchanged. Ultrasound showed significant median nerve compression with flexor tendon thickening. Metabolic investigations showed no evidence of a storage disorder. Trio whole exome sequencing showed two de novo likely pathogenic variants in ADAMTS10: c.1174delC, p.H392TfsX9 and a deletion of exons 3-8. Her exam was also noted to show bilateral camptodactyly and brachydactyly, and bilateral cataracts characteristic of WMS. Conclusions: Identifying the etiology of CTS is important for management and prognosis. WMS is a genetic connective tissue disorder that can cause brachydactyly and abnormal tendon thickening, which can have implications on surgical outcomes. Awareness of this diagnosis prior to surgery would allow for better patient counseling and management decisions.

EFFECTS OF RIBOSE-INDUCED GLYCATION ON THE ELASTIC MODULUS OF COLLAGEN FIBRILS OBSERVED BY ATOMIC FORCE MICROSCOPY

The interplay between diabetes mellitus and the structural integrity of collagen has significant implications for tissue functionality and disease progression. The aim of this study was to empirically investigate the effects of ribose-induced glycation on the biomechanical properties of collagen fibrils, using atomic force microscopy for precise measurements. Methodology. We used collagen fibrils from the common digital extensor (CDE) and superficial digital flexor (SDF) tendons of an adult bovine model to mimic the glycation processes that occur in diabetic pathology. The samples underwent controlled glycation by incubation with ribose for 24 hours and 14 days compared to phosphate buffered saline treated controls. A Bioscope Catalyst atomic force microscope (Bruker, USA) was used for all atomic force microscopy imaging in this study. Scientific novelty. Our results show a marked increase in the elastic modulus of collagen fibrils after ribose treatment, indicating stiffening with glycation. Notably, SDF fibrils showed a greater increase in stiffness after 24 hours of ribose exposure compared to CDE fibrils, suggesting variations in glycation rates relative to fibril anatomy. Statistical analyses confirmed the significance of these findings and provided a model for understanding similar processes in human diabetes. Conclusions. The different response to glycation observed between CDE and SDF fibrils prompts further investigation into the role of anatomical and structural factors in glycation susceptibility. Identification of tissues at higher risk of glycation-induced damage could lead to the development of targeted prevention strategies for diabetic complications. In addition, the potential for pharmacological intervention to inhibit glycation processes or enhance advanced glycation end products (AGEs) degradation offers a promising avenue for mitigating the progression of diabetes-related complications. The results of this study highlight the potential of ribose-induced changes in collagen as a model for diabetes-related tissue changes and propose a mechanistic framework that could guide the development of interventions aimed at mitigating the effects of collagen-related diabetic complications.

Current trends in the prevention of adhesions after zone 2 flexor tendon repair.

Treating flexor tendon injuries within the digital flexor sheath (commonly referred to as palmar hand zone 2) presents both technical and logistical challenges. Success hinges on striking a delicate balance between safeguarding the surgical repair for tendon healing and initiating early rehabilitation to mitigate the formation of tendon adhesions. Adhesions between tendon slips and between tendons and the flexor sheath impede tendon movement, leading to postoperative stiffness and functional impairment. While current approaches to flexor tendon repair prioritize maximizing tendon strength for early mobilization and adhesion prevention, factors such as pain, swelling, and patient compliance may impede postoperative rehabilitation efforts. Moreover, premature mobilization could risk repair failure, necessitating additional surgical interventions. Pharmacological agents offer a potential avenue for minimizing inflammation and reducing adhesion formation while still promoting normal tendon healing. Although some systemic and local agents have shown promising results in animal studies, their clinical efficacy remains uncertain. Limitations in these studies include the relevance of chosen animal models to human populations and the adequacy of tools and measurement techniques in accurately assessing the impact of adhesions. This article provides an overview of the clinical challenges associated with flexor tendon injuries, discusses current on- and off-label agents aimed at minimizing adhesion formation, and examines investigational models designed to study adhesion reduction after intra-synovial flexor tendon repair. Understanding the clinical problem and experimental models may serve as a catalyst for future research aimed at addressing intra-synovial tendon adhesions following zone 2 flexor tendon repair.

Percutaneous Surgery for Trigger Finger Treatment Using a Novel Surgical Device: An Experimental Study on Fresh Cadavers

Trigger finger, a stenosing tenosynovitis of the flexor tendon at the A1 pulley, can cause pain and impair daily activities. Despite common surgical interventions, postsurgical complications are frequent, prompting the search for less invasive techniques. An experimental study was conducted on fresh cadavers to compare three techniques: the first using a PulleyCut without ultrasound guidance, the second using a PulleyCut with ultrasound guidance, and the third using a percutaneous needle technique. The complete release of the A1 pulley, integrity of the A2 pulley, flexor tendons, and neurovascular bundles were assessed. The new device group and the ultrasound-guided group demonstrated 100% complete release of the A1 pulley, whereas the needle group achieved only 38% success. There were no A2 pulley injuries in any group. Flexor tendons were injured in 7% of cases in the new device group and 77% in the needle group. A neurovascular injury occurred in the needle group. Compared with the percutaneous needle technique, the new device proved safe and effective for A1 pulley release, minimizing damage to flexor tendons and neurovascular structures. Ultrasound did not provide significant advantages, suggesting that the new device can be confidently used without ultrasound assistance. The PulleyCut represents a promising percutaneous technique for trigger finger treatment, demonstrating superiority over the needle technique in terms of efficacy and safety. These results encourage future clinical investigations to validate its practical application. Therapeutic IIc.

Ultrasound-guided minimally invasive thread release of Guyon’s canal: initial experience in cadaveric specimens

ObjectiveGuyon’s canal syndrome is caused by compression of the ulnar nerve at the wrist, occasionally requiring decompression surgery. In recent times, minimally invasive approaches have gained popularity. The aim of this study was to assess the efficacy and safety of ultrasound-guided thread release for transecting the palmar ligament in Guyon’s canal without harming surrounding structures, in a cadaveric specimen model.MethodsAfter ethical approval, thirteen ultrasound-guided thread releases of Guyon’s canal were performed on the wrists of softly embalmed anatomic specimens. Cadavers showing injuries or prior operations at the hand were excluded. Subsequently, the specimens were dissected, and the outcome of the interventions and potential damage to adjacent anatomical structures as well as ultrasound visibility were evaluated with a score from one to three.ResultsOut of 13 interventions, a complete transection was achieved in ten cases (76.9%), and a partial transection was documented in three cases (23.1%). Irrelevant lesions on the flexor tendons were observed in two cases (15.4%), and an arterial branch was damaged in one (7.7%). Ultrasound visibility varied among specimens, but essential structures were delineated in all cases.ConclusionUltrasound-guided thread release of Guyon’s canal has shown promising first results in anatomic specimens. However, further studies are required to ensure the safety of the procedure.Relevance statementOur study showed that minimally invasive ultrasound-guided thread release of Guyon’s canal is a feasible approach in the anatomical model. The results may provide a basis for further research and refinement of this technique.Key points• In Guyon’s canal syndrome, the ulnar nerve is compressed at the wrist, often requiring surgical release.• We adapted and tested a minimally invasive ultrasound-guided thread release technique in anatomic specimens.• The technique was effective; however, in one specimen, a small anatomic branch was damaged.Graphical

Comparative imaging of septic navicular osteomyelitis caused by a solar penetration injury in a 15‐day‐old Shire foal

SummaryA 15‐day‐old female Shire foal presented for acute lameness after sustaining a solar penetration injury, due to a nail, to the right hind sole 4 days previously. The foal was moderately lame at walk; all vital parameters were within normal limits. Clinical examination of the foot found a 2 mm long slit‐like defect in the plantar third of the lateral body of the frog. Radiographs revealed an ill‐defined rounded radiolucency within the navicular spongiosa that was surrounded by a halo of increased radiopacity. Transcuneal ultrasound corroborated the findings and found the navicular bone lesion to be closely associated with a hypoechogenic region within the lateral lobe of the deep digital flexor tendon (DDFT) all of which was continuous with a hypoechogenic tract extending from the sole. Computed tomographic examination confirmed a tract extending from the solar surface into the lateral portion of the navicular bone and confirmed a suspected impacted bone fragment. A diagnosis of septic navicular osteomyelitis and bursitis was made. The tract, navicular bone and DDFT were surgically debrided and navicular bursa lavage performed. The foal initially recovered well but navicular bursal sepsis recurred 6 days post‐operatively and the foal was euthanised. This report provides comprehensive comparative imaging of septic navicular osteomyelitis and bursitis secondary to a solar penetration in a 15‐day‐old foal and highlights the importance of different imaging modalities in case assessment and management.

Mechanical properties, collagen and glycosaminoglycan content of equine superficial digital flexor tendons are not affected by training.

Physical activity can activate extracellular matrix (ECM) protein synthesis and influence the size and mechanical properties of tendon. In this study, we aimed to investigate whether different training histories of horses would influence the synthesis of collagen and other matrix proteins and alter the mechanical properties of tendon. Samples from superficial digital flexor tendon (SDFT) from horses that were either (a) currently race trained (n = 5), (b) previously race trained (n = 5) or (c) untrained (n = 4) were analysed for matrix protein abundance (mass spectrometry), collagen and glycosaminoglycan (GAG) content, ECM gene expression and mechanical properties. It was found that ECM synthesis by tendon fibroblasts invitro varied depending upon the previous training history. In contrast, fascicle morphology, collagen and GAG content, mechanical properties and ECM gene expression of the tendon did not reveal any significant differences between groups. In conclusion, although we could not identify any direct impact of the physical training history on the mechanical properties or major ECM components of the tendon, it is evident that horse tendon cells are responsive to loading invivo, and the training background may lead to a modification in the composition of newly synthesised matrix.