Aged Tendons Exhibit Altered Mechanisms of Strain-Dependent Extracellular Matrix Remodeling

Aging is a primary risk factor for degenerative tendon injuries, yet the etiology and progression of this degeneration are poorly understood. While aged tendons have innate cellular differences that support a reduced ability to maintain mechanical tissue homeostasis, the response of aged tendons to altered levels of mechanical loading has not yet been studied. To address this question, we subjected young and aged murine flexor tendon explants to various levels of in vitro tensile strain. We first compared the effect of static and cyclic strain on matrix remodeling in young tendons, finding that cyclic strain is optimal for studying remodeling in vitro. We then investigated the remodeling response of young and aged tendon explants after 7 days of varied mechanical stimulus (stress deprivation, 1%, 3%, 5%, or 7% cyclic strain) via assessment of tissue composition, biosynthetic capacity, and degradation profiles. We hypothesized that aged tendons would show muted adaptive responses to changes in tensile strain and exhibit a shifted mechanical setpoint, at which the remodeling balance is optimal. Interestingly, we found that 1% cyclic strain best maintains native physiology while promoting extracellular matrix (ECM) turnover for both age groups. However, aged tendons display fewer strain-dependent changes, suggesting a reduced ability to adapt to altered levels of mechanical loading. This work has a significant impact on understanding the regulation of tissue homeostasis in aged tendons, which can inform clinical rehabilitation strategies for treating elderly patients.

Higher risk of Achilles tendon ruptures at competition than training sites in female collegiate gymnasts

BACKGROUND

Reportedly, 17.2% of collegiate female gymnasts experience Achilles tendon ruptures (ATRs). Cumulative microtraumas resulting in chronic tendinopathy/tendinitis may contribute to this high injury risk. We hypothesized that the risk of ATRs in female collegiate gymnasts increases with years of competitive gymnastics, that non-steroidal anti-inflammatory drug (NSAID) use is associated with less ATRs, and that the risk is larger during competition than training.

METHODS

Female gymnasts from 78 USA collegiate teams completed a survey assessing the prevalence of ATRs, NSAID use, age at which competitive gymnastics started and age at which ATR occurred, and whether ATRs occurred during training or competition.

RESULTS

Twenty-one of 103 gymnasts (20.4%, 95% CI: 13.6% to 29.4%) experienced ATRs. Eighteen of 21 ruptures (85.7%, 95% CI: 61.3% to 95.8%) occurred after more than ten years of competitive gymnastics (mean: 14.0±2.6 years, 95% CI: 12.8 to 15.2 years). ATRs occurred 0.08±0.01 (95% CI: 0.06 to 0.11) times per 1000 hours at training versus 1.85±0.11 (95% CI: 1.60 to 2.10) times per 1000 hours at competition (P<0.05). Prevalence of NSAID use was 27.6% (95% CI: 18.6% to 39.0%) in gymnasts without ATR but only 5.5% (95% CI: 0.6% to 35.5%, P=0.09) in gymnasts with ATR. Multiple regression analysis demonstrated a negative association between NSAID use and incidence of ATRs (P<0.05).

CONCLUSIONS

Female collegiate gymnasts are at high risk for ATRs, especially after more than ten years of competitive gymnastics and during competition.

Establishment of a Mouse Degenerative Model of Patellar Tendinopathy with Upregulation of Inflammation

There is no mouse model of patellar tendinopathy. This study aimed to establish a mouse inflammatory and degenerative patellar tendon injury model, which will facilitate research on patellar tendinopathy using advanced molecular tools including transgenic models. Collagenase at different doses (low dose (LD), medium dose (MD), high dose (HD)) or saline was injected over the mouse patellar tendon. At weeks 1, 2, 4, and 8 post-injection, the tendons were harvested for histology and further examined by micro-computed tomography (microCT) imaging at week 8. The optimal dose group and the saline group were further evaluated by immunohistochemical staining, gait pattern, and biomechanical properties. The histopathological score increased dose-dependently post-collagenase injection. Ectopic mineralization was observed and increased with collagenase dose. The LD group was selected for further analysis. The expression of IL-10, TNF-α, and MMP-1 significantly increased post-injection. The changes of limb idleness index (ΔLII) compared to preinjury state were significantly higher, while the ultimate load, stiffness, ultimate stress, and maximum Young's modulus were significantly lower in the LD group compared to the saline group. A mouse inflammatory degenerative model of patellar tendon injury resembling tendinopathy was established as indicated by the dose-dependent increase in tendon histopathology, ectopic calcification, decrease in biomechanical properties, and pain-associated gait changes.

Local and Systemic Side Effects of Corticosteroid Injections for Musculoskeletal Indications

Corticosteroid injections can be associated with a range of potential side effects, which may be classified as local or systemic and further stratified as immediate or delayed in onset. Radiologists performing image-guided musculoskeletal injections should recognize the potential side effects of corticosteroid medication when counseling patients before injection and consider such side effects in planning individual injections. This Review summarizes the available evidence regarding the local and systemic side effects of corticosteroid injections performed for musculoskeletal indications. Local side effects include postinjection flare, skin hypopigmentation and atrophy, infection, tendon rupture, accelerated progression of osteoarthritis, and osseous injury. Systemic side effects include adrenal suppression or insufficiency, facial flushing, hypertension, hyperglycemia, and osteoporosis. Additional targeted counseling is warranted regarding side effects that are specific to certain patient populations (i.e., premenopausal women, patients with diabetes, athletes, and pediatric patients). Corticosteroid injections are contraindicated in the presence of superficial or deep infection, fracture, or a prosthetic joint. Guidelines on the frequency, duration, and maximal lifetime use of corticosteroid injections are currently lacking. Further research is needed regarding the long-term complications of continuous corticosteroid use, particularly with regard to osseous effects.

Mild untreated hypercholesterolaemia affects mechanical properties of the Achilles tendon but not gastrocnemius muscle

Tendon xanthoma and altered mechanical properties have been demonstrated in people with familial hypercholesterolaemia. However, it is unclear whether mild, untreated hypercholesterolaemia alters musculotendinous mechanical properties and muscle architecture. We conducted a case-control study of adults aged 50 years and over, without lower limb injury or history of statin medication. Based on fasting low-density lipoprotein (LDL) cholesterol levels, 6 participants had borderline high LDL (>3.33 mmol/L) and 6 had optimal LDL cholesterol (<2.56 mmol/L). Using shear wave elastography, shear wave velocity (SWV) of the Achilles tendon and gastrocnemius medialis muscle (a proxy for stiffness), along with muscle fascicle length and pennation angle were measured under four passive tensile loads (0, 0.5, 1.0, 1.5 kg) applied via a pulley system. Differences between groups were found for tendon SWV but not muscle SWV, fascicle length or pennation angle. Participants with hypercholesterolaemia showed greater SWV (mean difference, 95 % CI: 2.4 m/s, 0.9 to 4.0, P = 0.024) compared to the control group across all loads. These findings suggest that adults with mild hypercholesterolaemia have increased tendon stiffness under low passive loads, while muscle was not affected. Future research is needed to confirm findings in a larger cohort and explore the impact of hypercholesterolaemia on tendon fatigue injury and tendinopathy.

Patellar Tendon Load Progression during Rehabilitation Exercises: Implications for the Treatment of Patellar Tendon Injuries

PURPOSE

This study aimed to evaluate patellar tendon loading profiles (loading index, based on loading peak, loading impulse, and loading rate) of rehabilitation exercises to develop clinical guidelines to incrementally increase the rate and magnitude of patellar tendon loading during rehabilitation.

METHODS

Twenty healthy adults (10 females/10 males, 25.9 ± 5.7 yr) performed 35 rehabilitation exercises, including different variations of squats, lunge, jumps, hops, landings, running, and sports specific tasks. Kinematic and kinetic data were collected, and a patellar tendon loading index was determined for each exercise using a weighted sum of loading peak, loading rate, and cumulative loading impulse. Then the exercises were ranked, according to the loading index, into tier 1 (loading index ≤0.33), tier 2 (0.33 < loading index <0.66), and tier 3 (loading index ≥0.66).

RESULTS

The single-leg decline squat showed the highest loading index (0.747). Other tier 3 exercises included single-leg forward hop (0.666), single-leg countermovement jump (0.711), and running cut (0.725). The Spanish squat was categorized as a tier 2 exercise (0.563), as was running (0.612), double-leg countermovement jump (0.610), single-leg drop vertical jump (0.599), single-leg full squat (0.580), double-leg drop vertical jump (0.563), lunge (0.471), double-leg full squat (0.428), single-leg 60° squat (0.411), and Bulgarian squat (0.406). Tier 1 exercises included 20 cm step up (0.187), 20 cm step down (0.288), 30 cm step up (0.321), and double-leg 60° squat (0.224).

CONCLUSIONS

Three patellar tendon loading tiers were established based on a combination of loading peak, loading impulse, and loading rate. Clinicians may use these loading tiers as a guide to progressively increase patellar tendon loading during the rehabilitation of patients with patellar tendon disorders and after anterior cruciate ligament reconstruction using the bone-patellar tendon-bone graft.

Tendon Elongation and Function After Delayed or Standard Loading of Surgically Repaired Achilles Tendon Ruptures: A Randomized Controlled Trial

BACKGROUND

Achilles tendon ruptures often result in long-term functional deficits despite accelerated (standard) rehabilitation.

PURPOSE/HYPOTHESIS

The purpose of this study was to investigate if delayed loading would influence functional, clinical, and structural outcomes of the muscles and tendon 1 year after a surgical repair. It was hypothesized that delaying the loading would reduce the heel-rise height deficit 1 year after Achilles tendon rupture.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

In total, 48 patients with a surgically repaired Achilles tendon rupture were randomized to 2 groups: the standard group received the currently accepted rehabilitation, and the delayed group received the same rehabilitation except that initial loading was delayed by 6 weeks. The primary outcome was the heel-rise height difference between the injured and uninjured sides at 1 year. The secondary outcomes were (1) tendon length measured with magnetic resonance imaging, (2) muscle fascicle length and pennation angle of the gastrocnemius medialis muscle, (3) Doppler activity measured with ultrasonography, (4) Achilles tendon Total Rupture Score (ATRS), and (5) isometric muscle strength.

RESULTS

The mean heel-rise height deficits for the standard and delayed groups were -2.2 cm and -2.1 cm, respectively (P = .719). The soleus part of the tendon was already elongated 1 week after surgery in both groups without a between-group difference (side-to-side difference: standard, 16.3 mm; delayed, 17.5 mm; P = .997) and did not change over 52 weeks. The gastrocnemius tendon length was unchanged at 1 week but elongated over time without a between-group difference (side-to-side difference at 52 weeks: standard, 10.5 mm; delayed, 13.0 mm; P = .899). The delayed group had less Doppler activity at 12 weeks (P = .006) and a better ATRS (standard, 60 points; delayed, 72 points; P = .032) at 52 weeks.

CONCLUSION

Delayed loading was not superior to standard loading in reducing the heel-rise height difference at 1 year. The data indirectly suggested reduced inflammation in the initial months and a better patient-reported outcome at 1 year in the delayed group. The soleus part of the tendon was already markedly elongated (35%) 1 week after surgery, while the length of the gastrocnemius tendon was unchanged at 1 week but was 6% elongated at 1 year. Together, these data indirectly suggest that the delayed group fared better, although this finding needs to be confirmed in future investigations.

REGISTRATION

NCT04263493 (ClinicalTrials.gov identifier).

The trend of allogeneic tendon decellularization: literature review

Tendon injuries repair is a significant burden for orthopaedic surgeons. Finding a proper graft material to repair tendon is one of the main challenges in orthopaedics, for which the requirement of substitute for tendon repair would be different for each clinical application. Among biological scaffolds, the use of decellularized tendon increasingly represents an interesting approach to treat tendon injuries and several articles have investigated the approaches of tendon decellularization. To understand the outcomes of the the approaches of tendon decellularization on effect of tendon transplantation, a literature review was performed. This review was conducted by searching in Pubmed and Embase and 64 studies were included in this study. The findings revealed that the common approaches to decellularize tendon include chemical, physical, and enzymatic decellularization methods or their combination. With the development of tissue engineering, researchers also put forward new theories such as automatic acellular machine, 3D printing technology to manufacture acellular scaffold.

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.

Complications after arthroscopic triangular fibrocartilage complex (TFCC) surgery

Wrist arthroscopy is a valuable and widely utilized tool in the treatment of triangular fibrocartilage complex (TFCC) injuries. These procedures include synovectomy alone, peri-capsular or transosseous repair, and arthroscopic-assisted reconstruction, and each are associated with specific complications. This review describes the types of complications and their rates in different types of arthroscopic TFCC surgery reported in the literature and in our centre. Across the spectrum of arthroscopic TFCC surgery, complication rates and the learning curve increase with surgical complexity. Relevant anatomy, prevention and management of complications including nerve injury and irritation, extensor tendon injury and tendinitis, fracture, stiffness, and persistence of symptoms or instability are discussed. Vigilance to anatomical details and careful dissection can help to reduce complications that may result in disturbing pain and functional loss.

Advancements in 3D-printed artificial tendon

Millions of people have been reported with tendon injuries each year. Unfortunately, Tendon injuries are increasing rapidly due to heavy exercise and a highly aging population. In addition, the introduction of 3D-printing technology in the area of tendon repair and replacement has resolved numerous issues and significantly improved the quality of artificial tendons. This advancement has also enabled us to explore and identify the most effective combinations of biomaterials that can be utilized in this field. This review discusses the recent development of the 3D-printed artificial tendon; where recently, some research investigated the most suitable pore sizes, diameter, and strength for scaffolds to have high tendon cells ingrowth and proliferation, giving a better understanding of the effects of densities and structure patterns on tendon's mechanical properties. In addition, it presents the divergence between 3D-printed tendons and other tissue and how the different 3D-printing techniques and models participated in this development.

Micro- and nanostructure specific X-ray tomography reveals less matrix formation and altered collagen organization following reduced loading during Achilles tendon healing

Recovery of the collagen structure following Achilles tendon rupture is poor, resulting in a high risk for re-ruptures. The loading environment during healing affects the mechanical properties of the tendon, but the relation between loading regime and healing outcome remains unclear. This is partially due to our limited understanding regarding the effects of loading on the micro- and nanostructure of the healing tissue. We addressed this through a combination of synchrotron phase-contrast X-ray microtomography and small-angle X-ray scattering tensor tomography (SASTT) to visualize the 3D organization of microscale fibers and nanoscale fibrils, respectively. The effect of in vivo loading on these structures was characterized in early healing of rat Achilles tendons by comparing full activity with immobilization. Unloading resulted in structural changes that can explain the reported impaired mechanical performance. In particular, unloading led to slower tissue regeneration and maturation, with less and more disorganized collagen, as well as an increased presence of adipose tissue. This study provides the first application of SASTT on soft musculoskeletal tissues and clearly demonstrates its potential to investigate a variety of other collagenous tissues. STATEMENT OF SIGNIFICANCE: Currently our understanding of the mechanobiological effects on the recovery of the structural hierarchical organization of injured Achilles tendons is limited. We provide insight into how loading affects the healing process by using a cutting-edge approach to for the first time characterize the 3D micro- and nanostructure of the regenerating collagen. We uncovered that, during early healing, unloading results in a delayed and more disorganized regeneration of both fibers (microscale) and fibrils (nanoscale), as well as increased presence of adipose tissue. The results set the ground for the development of further specialized protocols for tendon recovery.

Inhibition of CX3CL1 by treadmill training prevents osteoclast-induced fibrocartilage complex resorption during TBI healing

Introduction

The healing of tendon-bone injuries is very difficult, often resulting in poor biomechanical performance and unsatisfactory functional recovery. The tendon-bone insertion has a complex four distinct layers structure, and previous studies have often focused on promoting the regeneration of the fibrocartilage layer, neglecting the role of its bone end repair in tendon-bone healing. This study focuses on the role of treadmill training in promoting bone regeneration at the tendon-bone insertion and its related mechanisms.

Methods

After establishing the tendon-bone insertion injury model, the effect of treadmill training on tendon-bone healing was verified by Micro CT and HE staining; then the effect of CX3CL1 on osteoclast differentiation was verified by TRAP staining and cell culture; and finally the functional recovery of the mice was verified by biomechanical testing and behavioral test.

Results

Treadmill training suppresses the secretion of CX3CL1 and inhibits the differentiation of local osteoclasts after tendon-bone injury, ultimately reducing osteolysis and promoting tendon bone healing.

Discussion

Our research has found the interaction between treadmill training and the CX3CL1-C3CR1 axis, providing a certain theoretical basis for rehabilitation training.

Personalized tendon loading reduces muscle-tendon imbalances in male adolescent elite athletes

An imbalanced adaptation of muscle strength and tendon stiffness in response to training may increase tendon strain (i.e., the mechanical demand on the tendon) and consequently tendon injury risk. This study investigated if personalized tendon loading inducing tendon strain within the effective range for adaptation (4.5%-6.5%) can reduce musculotendinous imbalances in male adolescent handball athletes (15-16 years). At four measurement time points during a competitive season, we assessed knee extensor muscle strength and patellar tendon mechanical properties using dynamometry and ultrasonography and estimated the tendon's structural integrity with a peak spatial frequency (PSF) analysis of proximal tendon ultrasound scans. A control group (n = 13) followed their usual training routine, an intervention group (n = 13) integrated tendon exercises into their training (3x/week for ~31 weeks) with a personalized intensity corresponding to an average of ~6.2% tendon strain. We found a significant time by group interaction (p < 0.005) for knee extensor muscle strength and normalized patellar tendon stiffness with significant increases over time only in the intervention group (p < 0.001). There were no group differences or time-dependent changes in patellar tendon strain during maximum voluntary contractions or PSF. At the individual level, the intervention group demonstrated lower fluctuations of maximum patellar tendon strain during the season (p = 0.005) and a descriptively lower frequency of athletes with high-level tendon strain (≥9%). The findings suggest that the personalized tendon loading program reduced muscle-tendon imbalances in male adolescent athletes, which may provide new opportunities for tendon injury prevention.

TrkA-mediated sensory innervation of injured mouse tendon supports tendon sheath progenitor cell expansion and tendon repair

Peripheral neurons terminate at the surface of tendons partly to relay nociceptive pain signals; however, the role of peripheral nerves in tendon injury and repair remains unclear. Here, we show that after Achilles tendon injury in mice, there is new nerve growth near tendon cells that express nerve growth factor (NGF). Conditional deletion of the Ngf gene in either myeloid or mesenchymal mouse cells limited both innervation and tendon repair. Similarly, inhibition of the NGF receptor tropomyosin receptor kinase A (TrkA) abrogated tendon healing in mouse tendon injury. Sural nerve transection blocked the postinjury increase in tendon sensory innervation and the expansion of tendon sheath progenitor cells (TSPCs) expressing tubulin polymerization promoting protein family member 3. Single cell and spatial transcriptomics revealed that disruption of sensory innervation resulted in dysregulated inflammatory signaling and transforming growth factor-β (TGFβ) signaling in injured mouse tendon. Culture of mouse TSPCs with conditioned medium from dorsal root ganglia neuron further supported a role for neuronal mediators and TGFβ signaling in TSPC proliferation. Transcriptomic and histologic analyses of injured human tendon biopsy samples supported a role for innervation and TGFβ signaling in human tendon regeneration. Last, treating mice after tendon injury systemically with a small-molecule partial agonist of TrkA increased neurovascular response, TGFβ signaling, TSPC expansion, and tendon tissue repair. Although further studies should investigate the potential effects of denervation on mechanical loading of tendon, our results suggest that peripheral innervation is critical for the regenerative response after acute tendon injury.

Quantitative Assessment of Calf Muscle Volume, Strength, and Quality After Achilles Tendon Rupture Repair: A 1-Year Prospective Follow-up Study

BACKGROUND

A number of studies have reported that calf muscle atrophy is a common long-term problem after Achilles tendon repair; however, there is still a lack of data concerning early postoperative morphological changes in the calf muscle after surgery.

PURPOSE

To investigate changes over time in calf muscle volume and fatty degeneration during 1 year after Achilles tendon repair.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A prospective 1-year serial magnetic resonance imaging study was carried out with 20 patients who underwent tendon repair for unilateral acute Achilles tendon rupture. The magnetic resonance imaging assessment in addition to clinical and functional evaluations was performed at 1, 3, 6, and 12 months after surgery. The muscle volume of the medial and lateral gastrocnemius, soleus, and flexor hallucis longus (FHL) and fatty degeneration of the medial and lateral gastrocnemius and soleus were measured for the calf muscles, and the relative volume and fatty degeneration changes in the affected leg compared with the healthy contralateral leg were calculated as a percentage ([injured/healthy control] × 100) to assess structural changes over time.

RESULTS

Muscle volumes of the medial gastrocnemius, lateral gastrocnemius, soleus, and FHL were 92.3%, 92.8%, 84.6%, and 95.9% at 12 months after surgery, respectively. Medial and lateral gastrocnemius and FHL muscle volumes improved over time and recovered to almost equal to that of the healthy side at 12 months after surgery. The soleus muscle volume did not recover significantly over time and was statistically significantly smaller than that of the healthy side at 12 months (P = .029). Fatty degeneration rates of the medial gastrocnemius, lateral gastrocnemius, and soleus were 118.2%, 113.9% and 121.1% at 12 months after surgery, respectively. Fatty degeneration of the medial and lateral gastrocnemius did not change significantly, but there was a statistically significant increase in fatty degeneration of the soleus over time (P < .001).

CONCLUSION

Within the triceps surae muscle, the soleus was the most negatively affected by injury and repair for both muscle volume and fatty degeneration. Postoperative management to recover the soleus muscle function before a return to sporting activities should be considered in the future.

Risk factors for Achilles tendon rupture: an updated systematic review

OBJECTIVE

Identifying risk factors for Achilles Tendon Rupture (ATR) is one of the first necessary steps for its prevention. This systematic review aimed to update the systematic review published in 2014 in ATR etiology.

METHODOLOGY

A systematic review was carried out using PubMed, EBSCO, and ScienceDirect databases. All types of research studies (Randomized Control Trials - RCTs, Cohort studies, Case-control studies and Cross-sectional studies) that considered ATR, were eligible. The inclusion criteria for eligibility of the studies were to be written in the English language, and to include populations of men and/or women, both athletes, and non-athletes, healthy individuals, and patients. Two independent reviewers used the assessment instrument Newcastle-Ottawa Scale independently, to evaluate the quality of each selected study. Further, two reviewers worked independently to extract the study characteristics, and the GRADE methodology was used to assess the level of certainty of each risk factor.

RESULTS

From 9526 studies initially identified, 19 studies were eligible for further analysis to identify risk factors for ATR. Seventeen studies were considered good quality, and two studies fair quality. Low to very low certainty of evidence was found for the following medications: steroids, quinolones, and oral bisphosphonate, as well as for other factors such as chronic tendon inflammation and Achilles' tendinopathy, spring season, diabetes, previous musculoskeletal injury, regular participation in athletic activity, hyperparathyroidism, renal failure, and genetic factors.

CONCLUSIONS

The risk factors found prove that ATR is a multifactorial injury. Appropriate methodologies and well-designed studies are needed to determine the factors and their significance in ATR risk. Finally, the role of biomechanical and psychological aspects in the ATR etiology may be of interest in future studies, as we could not extract relative data in our review.

[Distal radius fracture-tactic and approach]

OBJECTIVE

The aim of surgical treatment is fracture healing with restored alignment, rotation, and joint surface. Stable fixation allows for functional postoperative aftercare.

INDICATIONS

Displaced intra- and extra-articular fractures which either could not be adequately reduced or in which a secondary displacement is to expected due to instability criteria. The following factors are considered instability criteria: age > 60 years, female, initial dorsal displacement > 20°, dorsal comminution, radial shortening > 5 mm, palmar displacement.

CONTRAINDICATIONS

The only absolute contraindication is if the patient is deemed unfit for surgery due to concerns regarding anesthesia. Old age is a relative contraindication, as it is currently debated whether older patients benefit from the operation.

SURGICAL TECHNIQUE

The surgical technique is guided by the fracture pattern. Palmar plating is most commonly performed. If the joint surface needs to be visualized, a dorsal approach (in combination with another approach or alone) or arthroscopically assisted fixation should be chosen.

POSTOPERATIVE MANAGEMENT

In general, a functional postoperative regime can be carried out after plate fixation with mobilization without weightbearing. Short-term splinting can provide pain relief. Concomitant ligamentous injuries and fixations, which are not stable enough for functional aftercare (such as k‑wires) require a longer period of immobilization.

RESULTS

Provided the fracture is reduced correctly, osteosynthesis improves functional outcome. The complication rate ranges between 9 and 15% with the most common complication being tendon irritation/rupture and plate removal. Whether surgical treatment holds the same benefits for patients > 65 years as for younger patients is currently under debate.

Dynamic Tensile Stress Promotes Regeneration of Achilles Tendon in a Panda Rope Bridge Technique Mice Model

Regeneration of ruptured Achilles tendon remains a clinical challenge owing to its limited regenerative capacity. Dynamic tensile stress plays a positive role in the regeneration of tendon, although the specific underlying mechanisms remain unclear. In this study, the Achilles tendon defect-regeneration model was created in male C57BL/6 mice aged 8 weeks. The animals were randomly assigned to four groups-repair, non-repair, repair with fixation, and non-repair with fixation. The repair group and repair with fixation group adopted the panda rope bridge technique (PRBT) repair method. Our results demonstrated the presence of more densely aligned and mature collagen fibers, as well as more tendon-related makers, in the repair group at both 2- and 4-week post-surgery. Furthermore, the biomechanical strength of the regenerated tendon in the repair group was highly improved. Most importantly, the expressions of integrin αv and its downstream and the phosphorylation levels of FAK and ERK were remarkably higher in the repair group than in the other groups. Furthermore, blocking FAK or ERK with selective inhibitors PF573228 and U0126 resulted in obvious adverse effects on the histological structure of the regenerated Achilles tendon. In summary, this study demonstrated that dynamic tensile stress based on the PRBT could effectively promote the regeneration of the Achilles tendon, suggesting that dynamic tensile stress enhances the cell proliferation and tenogenic differentiation via the activation of the integrin/FAK/ERK signaling pathway.

Terminating Corticosteroid Injection in Tendinopathy? Hasta la Vista, Baby

SYNOPSIS: Two recent randomized-controlled trials showed promising results of local corticosteroid injections combined with exercise therapy for Achilles tendinopathy and plantar fasciopathy. Should clinicians go back to using corticosteroid injections to treat tendinopathy? Are corticosteroids back (baby)? In this viewpoint we critically appraise the new evidence and humbly share our clinical reasoning when advising athletes about corticosteroid injections in practice. Our goal is to help clinicians decide what to do and what to recommend to patients. We prioritize the risk for higher recurrence rates and tendon rupture when weighing the reasonable treatment options for tendinopathy, and recommend against using corticosteroid injections. The best systematic review evidence shows that local corticosteroid injections are not effective for tendinopathies after the first few weeks, and produce worse long-term outcomes compared to other treatments. For now, we consider corticosteroid injections remain terminated. J Orthop Sports Phys Ther 2023;53(11):1-4. Epub: 28 July 2023. doi:10.2519/jospt.2023.11875.

Evaluating Risk Factors for Biceps Tendon Injuries in Softball Players: A Systematic Review

OBJECTIVE

Softball players commonly suffer overuse injuries due to the demands of repetitive throwing. The biceps tendon plays an important role in stabilizing the shoulder during the windmill pitch. The purpose of this study was to evaluate the measures used to identify and study biceps tendon pathology in softball players.

DESIGN

This was a systematic review.

SETTING

PubMed MEDLINE, Ovid MEDLINE, and EMBASE were searched.

PARTICIPANTS

Studies that investigated biceps tendon injuries in softball players.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Range of motion (ROM), strength, and visual analog scale data were collected.

RESULTS

Of 152 search results, 18 were included. A total of 536 of 705 athletes (76%) were softball players (average age 14-25 years). Five of 18 articles (27.7%) studied changes in external rotation with the shoulder at 90 degrees of abduction, and 4 of 18 (22.2%) studied internal rotation. Two of 18 studies (11.1%) examined ROM or strength changes in forward flexion.

CONCLUSIONS

While researchers agree that the windmill pitch places significant stress on the biceps tendon, our study finds that the metrics used to evaluate shoulder pathology in these players primarily evaluate the rotator cuff without isolating the biceps tendon. Future studies should include clinical tests and biomechanical metrics more specific to identifying biceps and labral pathology (eg, strength, fatigue, and ROM in glenohumeral forward flexion, elbow flexion, and forearm supination) and attempt to clarify differences in pathology between pitchers and position players to better characterize the frequency and severity of biceps tendon pathology in softball players.

Measurement of Healthy and Injured Triceps Surae Morphology

Achilles tendon injuries occur throughout the lifespan and can negatively affect quality of life and overall health. Achilles tendinopathy is generally classified as an overuse injury associated with fusiform tendon thickening, neovascularization, and interstitial tendon degeneration. Current literature suggests these structural changes are associated with symptoms and lower physical activity levels, as well as symptoms and lower extremity function in the long term. Surgically and non-surgically managed Achilles tendon ruptures result in increased tendon cross-sectional area (CSA) and a lengthened Achilles tendon. Both structural outcomes have clinical implications, as larger CSA positively predicts function, whereas increased tendon lengthening predicts reduced function after Achilles tendon rupture. Given the relationship between structural changes associated with Achilles tendon injuries for both injury severity and injury recovery, it is critical to be able to quantify Achilles tendon structure reliably and accurately. Silbernagel's group has established a valid and reliable method for efficiently evaluating triceps surae muscle and tendon structure. In this protocol, B-mode musculoskeletal ultrasound imaging is used to measure triceps surae structure, including Achilles tendon thickness and CSA, soleus thickness, and the presence of additional findings (calcifications and bursitis). B-mode extended field-of-view is used to measure Achilles tendon length and gastrocnemius anatomical CSA. Finally, power Doppler is used to identify intratendinous neovascularization. Quantification of triceps surae structure allows for comparison between limbs as well as longitudinal changes in response to exercise and treatment for healthy individuals and those with Achilles tendon injuries. This protocol has been used in many research studies to date and proves valuable in understanding the relationship between tendon structure and injury development, severity, and recovery. As ultrasound devices are becoming more affordable and portable, this protocol proves promising as a clinical tool, given its quick and efficient methods.

Aging and injury affect nuclear shape heterogeneity in tendon

Tissue level properties are commonly studied using histological stains assessed with qualitative scoring methods. As qualitative evaluation is typically insensitive, quantitative analysis provides additional information about pathological mechanisms, but cannot capture structural heterogeneity across cell subpopulations. However, molecular analyses of cell and nuclear behavior have identified that cell and more recently also nuclear shape are highly associated with cell function and malfunction. This study combined a Visually Aided Morpho-Phenotyping Image Recognition analysis that automatically segments cells based on their shape with an added capacity to further discriminate between cells in certain protein-rich extracellular matrix regions. We used tendon as a model system given the enormous changes in organization and cell and nuclear shape they undergo during aging and injury. Our results uncover that multiple shape modes of nuclei exist during maturity and aging in rat tendon and that distinct subgroups of cell nuclei shapes exist in proteoglycan-rich regions during aging. With injury, several immunomarkers (αSMA, CD31, CD146) were associated with more rounded shape modes. In human tendons, the cell nuclei at sites of injury were found to be more rounded relative to uninjured tissues. To conclude, the tendon tissue changes occurring during aging and injury could be associated with a variation in cell nuclear morphology and the appearance of various region-specific subpopulations. Thus, the methodologies developed allow for a deeper understanding of cell heterogeneity during tendon aging and injury and may be extended to study further clinical applications.

Passive Ankle Plantarflexion Position and Skin Surface Blood Flow Adjacent to the Achilles Tendon

BACKGROUND

Open repair of the Achilles tendon carries a risk of wound complications and infection. The Achilles tendon is covered by a thin layer of skin and subcutaneous tissue, which has a fragile blood supply. The full plantarflexion position may cause sustained blanching of the skin above the Achilles tendon. However, no reports have described the in vivo blood flow (BF) changes at the skin surface with ankle position. This study aimed to use laser Doppler flowmetry to evaluate the in vivo BF at the skin surface and thereby clarify the changes in BF with ankle position.

METHODS

The study cohort comprised 30 feet in 15 participants with no history of Achilles tendon rupture. Laser Doppler flowmetry was used to measure the BF at the skin surface above the medial Achilles tendon in the natural plantarflexion (NP) and full plantarflexion (FP) positions.

RESULTS

In the NP and FP positions, the BF at 5 cm proximal to the calcaneal insertion (frequent site of Achilles tendon rupture) was 1.50 ± 0.32 and 0.97 ± 0.28 mL/min/100 g, respectively (P < .0001).

CONCLUSION

The BF at the skin surface adjacent to the medial Achilles tendon at 5 cm proximal to the calcaneal insertion was significantly less in the FP position than the NP position.

Surgical treatment of high-grade acute intramuscular hamstring tendon injuries in athletes leads to predictable return to sports and no re-injuries

PURPOSE

The purpose of this study was to assess the post-operative return to sport and re-injury rates following surgical repair of acute, first-time, high-grade intramuscular hamstring tendon injuries in high level athletes.

METHODS

Patients were identified using the databases of two sports surgeons. Once patients were identified their clinical notes and imaging were reviewed to confirm that all patients had injuries to the intramuscular portion of the distal aspect of the proximal biceps femoris tendon. All imaging was reviewed by an experienced musculoskeletal radiologist to confirm diagnosis. Surgery for such injuries was indicated in high-level athletes presenting with acute hamstring injuries. All patients were operated on within 4 weeks. Outcomes included Tegner scores, return to sport, Lower Extremity Functional Score (LEFS), current hamstring symptoms and complications including re-injury.

RESULTS

Eleven injuries (10 patients) were included in the study. All patients were male and Australian Rules Football players. Six patients were professional athletes and 4 semi-professional athletes. Median age was 24.5 (range 21-29) and median follow-up period was 33.7 months (range; 16-65). 91% were British Athletic Muscle Injury Classification (BAMIC) 3c and 9% were BAMIC 4c. 91% were classed as MR2 and 9% as MR3 on the simplified four-grade injury classification. Athletes achieved return to play (RTP) at an average of 3.1 months (SD 1.0) post repair. All but one patient achieved a Tegner score equal to pre-injury levels. Maximum LEFS was achieved by all patients. Minor pain scores (all with VAS < 1/10) on sciatic and functional stretch were recorded in 36% and 27% of patients respectively, with subtle neural symptoms (9%) and subjective tightness (36%) also noted. There were no surgical complications in our patient cohort. No patients had a re-injury or re-operation.

CONCLUSIONS

Surgical repair of high-grade intramuscular tendon injuries of the biceps femoris hamstring muscle in athletes resulted in high levels of return to pre-injury sporting levels and no re-injuries. The intra-muscular tendon should be scrutinized when assessing hamstring injuries in elite sport and offer surgery in high-grade cases.

LEVEL OF EVIDENCE

IV.

Preclinical tendon and ligament models: Beyond the 3Rs (replacement, reduction, and refinement) to 5W1H (why, who, what, where, when, how)

Several tendon and ligament animal models were presented at the 2022 Orthopaedic Research Society Tendon Section Conference held at the University of Pennsylvania, May 5 to 7, 2022. A key objective of the breakout sessions at this meeting was to develop guidelines for the field, including for preclinical tendon and ligament animal models. This review summarizes the perspectives of experts for eight surgical small and large animal models of rotator cuff tear, flexor tendon transection, anterior cruciate ligament tear, and Achilles tendon injury using the framework: "Why, Who, What, Where, When, and How" (5W1H). A notable conclusion is that the perfect tendon model does not exist; there is no single gold standard animal model that represents the totality of tendon and ligament disease. Each model has advantages and disadvantages and should be carefully considered in light of the specific research question. There are also circumstances when an animal model is not the best approach. The wide variety of tendon and ligament pathologies necessitates choices between small and large animal models, different anatomic sites, and a range of factors associated with each model during the planning phase. Attendees agreed on some guiding principles including: providing clear justification for the model selected, providing animal model details at publication, encouraging sharing of protocols and expertise, improving training of research personnel, and considering greater collaboration with veterinarians. A clear path for translating from animal models to clinical practice was also considered as a critical next step for accelerating progress in the tendon and ligament field.

An Extracellular Vesicle-Cloaked Multifaceted Biocatalyst for Ultrasound-Augmented Tendon Matrix Reconstruction and Immune Microenvironment Regulation

The healing of tendon injury is often hindered by peritendinous adhesion and poor regeneration caused by the accumulation of reactive oxygen species (ROS), development of inflammatory responses, and the deposition of type-III collagen. Herein, an extracellular vesicles (EVs)-cloaked enzymatic nanohybrid (ENEV) was constructed to serve as a multifaceted biocatalyst for ultrasound (US)-augmented tendon matrix reconstruction and immune microenvironment regulation. The ENEV-based biocatalyst exhibits integrated merits for treating tendon injury, including the efficient catalase-mimetic scavenging of ROS in the injured tissue, sustainable release of Zn2+ ions, cellular uptake augmented by US, and immunoregulation induced by EVs. Our study suggests that ENEVs can promote tenocyte proliferation and type-I collagen synthesis at an early stage by protecting tenocytes from ROS attack. The ENEVs also prompted efficient immune regulation, as the polarization of macrophages (Mφ) was reversed from M1φ to M2φ. In a rat Achilles tendon defect model, the ENEVs combined with US treatment significantly promoted functional recovery and matrix reconstruction, restored tendon morphology, suppressed intratendinous scarring, and inhibited peritendinous adhesion. Overall, this study offers an efficient nanomedicine for US-augmented tendon regeneration with improved healing outcomes and provides an alternative strategy to design multifaceted artificial biocatalysts for synergetic tissue regenerative therapies.

Primary repair of acute versus chronic ruptures of the distal biceps tendon. Comparison of functional results in a case-control study

BACKGROUND

In the event of a rupture of the distal tendon of the biceps brachii, most authors recommend early reinsertion to recover optimal elbow function. However, these ruptures are not always diagnosed or promptly referred to surgeons, thus creating a delay in treatment. Studies reporting functional results in cases of chronic repair (greater than 21 days) of the distal biceps brachii tendon show an increased rate of complications.

HYPOTHESIS

Primary repairs of chronic ruptures (treatment delayed for more than 21 days) and acute ruptures of the distal biceps give the same functional results and the same rate of complications.

MATERIAL AND METHODS

We conducted a retrospective study between January 2017 and December 2021 comparing chronic primary repair of the distal biceps at the elbow (experimental group, comprising 75 patients) and acute (control group, comprising 135 patients) by endobutton. We analyzed the time between trauma and surgery, and assessed short- and long-term functional recovery by measuring residual pain (VAS), a collection of the following functional scores: Mayo Elbow Performance Score (MEPS), Quick Disabilities of the Arm, Shoulder and Hand (Q-DASH) and Patient-Rated Elbow Evaluation (PREE), as well as a measure of strength (as a percentage of the healthy side). We evaluated the rate of complications and radiographically analyzed the rate of heterotopic ossification.

RESULTS

The mean time between trauma and surgery was 73±66 days (experimental group) versus 11.2±5 days (control group). In the short-term (4.79±2.09 months), there was no significant difference in the MEPS, Q-DASH and PREE functional scores between the two groups (p=0.354, p=0.412 and p=0.958, respectively). In the long-term (28.9±17.9 months), the functional evolution remained similar. The recovery of strength in flexion and supination was 89.19±13.43% and 77.48±16.68%, respectively, and similar in the two cohorts (p=0.476 and p=0.395). There was no difference in the rate of complications; however, the rate of heterotopic ossification was higher in the control group (p=0.006).

DISCUSSION

The functional results and the recovery of strength did not change according to the time until surgery. Although the overall complication rate was similar, repairs of the biceps in less than 21 days led to more heterotopic ossification.

LEVEL OF EVIDENCE

III; retrospective case-control study.

Are commercial genetic injury tests premature?

INTRODUCTION

Several direct-to-consumer (DTC) genetic testing companies have emerged that claim to be able to test for susceptibility for musculoskeletal injuries. Although there are several publications on the emergence of this industry, none have critically evaluated the evidence for the use of genetic polymorphisms in commercial tests. The aim of this review was to identify, where possible, the polymorphisms and to evaluate the current scientific evidence for their inclusion.

RESULTS

The most common polymorphisms included COL1A1 rs1800012, COL5A1 rs12722, and GDF5 rs143383. The current evidence suggests that it is premature or even not viable to include these three polymorphisms as markers of injury risk. A unique set of injury-specific polymorphisms, which do not include COL1A1, COL5A1, or GDF5, identified from genome-wide association studies (GWAS) is used by one company in their tests for 13 sports injuries. However, of the 39 reviewed polymorphisms, 22 effective alleles are rare and absent in African, American, and/or Asian populations. Even when informative in all populations, the sensitivity of many of the genetic markers was low and/or has not been independently validated in follow-up studies.

CONCLUSIONS

The current evidence suggests it is premature to include any of the reviewed polymorphisms identified by GWAS or candidate gene approaches in commercial genetic tests. The association of MMP7 rs1937810 with Achilles tendon injuries, and SAP30BP rs820218 and GLCCI1 rs4725069 with rotator cuff injuries does warrant further investigation. Based on current evidence, it remains premature to market any commercial genetic test to determine susceptibility to musculoskeletal injuries.

Indirect Rectus Femoris Injury Mechanisms in Professional Soccer Players: Video Analysis and Magnetic Resonance Imaging Findings

OBJECTIVE

To describe injury mechanisms and magnetic resonance imaging (MRI) findings in acute rectus femoris (RF) injuries of soccer players using a systematic video analysis.

DESIGN

Descriptive case series study of consecutive RF injuries from November 2017 to July 2022.

SETTING

Two specialized sports medicine hospitals.

PARTICIPANTS

Professional male soccer players aged between 18 and 40 years, referred for injury assessment within 7 days after a RF injury, with an available video footage of the injury and a positive finding on an MRI.

INDEPENDENT VARIABLES

Rectus femoris injury mechanisms (specific scoring based on standardized models) in relation to RF muscle injury MRI findings.

MAIN OUTCOME MEASURES

Rectus femoris injury mechanism (playing situation, player/opponent behavior, movement, and biomechanics), location of injury in MRI.

RESULTS

Twenty videos of RF injuries in 19 professional male soccer players were analyzed. Three different injury mechanisms were seen: kicking (80%), sprinting (10%), and change of direction (10%). Isolated single-tendon injuries were found in 60% of the injuries. Of the kicking injuries, 62.5% included complete tendon ruptures, whereas both running injuries and none of the change of direction injuries were complete ruptures. The direct tendon was involved in 33% of the isolated injuries, and the common tendon was affected in all combined injuries.

CONCLUSIONS

Rectus femoris injuries typically occur during kicking among football players. Most of the RF injuries involve a complete rupture of at least one tendon. Kicking injuries can also affect the supporting leg, and sprinting can cause a complete tendon rupture, whereas change of direction seems not to lead to complete ruptures.

Pain neuroscience education in persistent painful tendinopathies: A scoping review from the Tendon PNE Network

OBJECTIVE

to conduct and report a scoping review of the available evidence of the effects and content of pain neuroscience education for patients with persistent painful tendinopathies.

METHODS

PubMed, Embase, Web of Science, CINAHL, SPORTDiscus, and grey literature databases were searched from database inception to May 2022. Randomised and non-randomised controlled trials, non-controlled clinical trials, cohort studies, case series, case studies including people with persistent painful tendinopathy aged ≥18 years, a pain education intervention, and in English were included. Studies were excluded if they were cross-sectional studies, reviews, editorials, abstracts, or full-text not available or if included heterogeneous study cohorts, patients with tendon rupture, or patients with systemic diseases.

RESULTS

five studies (n = 164) were included. Pain neuroscience education entailed face-to-face discussion sessions or educational materials including videos, brochures, paper drawings, and review questions. All studies used pain neuroscience education in conjunction with other interventions, obtaining significant benefits in outcomes related to pain, physical performance, or self-reported function, among others.

CONCLUSIONS

The application of pain neuroscience education in conjunction with other interventions seemed to improve several outcomes. However, considering the current knowledge about tendon pain and the scarcity of well-designed trials studying pain neuroscience education in tendinopathy, additional research is needed.

First MTP joint injuries: MR imaging findings in surgically managed patients

OBJECTIVES

Determine whether MR imaging findings or demographics predict surgical management in patients with first MTP joint injuries.

MATERIALS AND METHODS

Retrospective study of 161 forefoot MRs for traumatic first MTP injury (M:F 92:69, mean age 33 ± 13 yrs.). Two radiologists reviewed imaging for ligamentous, osseous, and tendinous injuries. Ligaments and tendons were graded as 0:normal, 1:sprain or strain, 2:partial tear, 3:complete tear. Osseous injuries were classified as edema, fracture, or cartilage injury. Clinical data obtained included sex, age, injury acuity, sport participation, level of sport, and treatment. Imaging findings and demographic data were assessed to determine predictive factors for surgical management. Statistics included kappa, chi-squared, Fisher's exact, and logistic regression.

RESULTS

Logistic regression (odds ratio [95% CI], p-value) showed that grade 2 or 3 injuries of the plantar ligamentous complex (2.87, [1.10, 7.48], p = 0.031), grade 2 or 3 injuries of the medial collateral ligament (3.24, [1.16, 9.08], p = 0.025), and participation in collegiate or professional sports (4.34 [1.64, 11.52], p = 0.003) were associated with an increased rate of surgical intervention. k = ligamentous injury (0.71-0.83), osseous trauma (0.88-0.95), and tendon injury (0.78). All other imaging findings and demographic factors were not significant predictors of surgery (p > 0.05).

CONCLUSION

Participation in collegiate or professional sports and tears of the plantar ligamentous complex or medial collateral ligament predicted surgical management in patients with first MTP trauma.

Emerging Quantitative Imaging Techniques in Sports Medicine

This article describes recent advances in quantitative imaging of musculoskeletal extremity sports injuries, citing the existing literature evidence and what additional evidence is needed to make such techniques applicable to clinical practice. Compositional and functional MRI techniques including T2 mapping, diffusion tensor imaging, and sodium imaging as well as contrast-enhanced US have been applied to quantify pathophysiologic processes and biochemical compositions of muscles, tendons, ligaments, and cartilage. Dual-energy and/or spectral CT has shown potential, particularly for the evaluation of osseous and ligamentous injury (eg, creation of quantitative bone marrow edema maps), which is not possible with standard single-energy CT. Recent advances in US technology such as shear-wave elastography or US tissue characterization as well as MR elastography enable the quantification of mechanical, elastic, and physical properties of tissues in muscle and tendon injuries. The future role of novel imaging techniques such as photon-counting CT remains to be established. Eventual prediction of return to play (ie, the time needed for the injury to heal sufficiently so that the athlete can get back to playing their sport) and estimation of risk of repeat injury is desirable to help guide sports physicians in the treatment of their patients. Additional values of quantitative analyses, as opposed to routine qualitative analyses, still must be established using prospective longitudinal studies with larger sample sizes.

MRI anatomy and injuries of the fingers

Magnetic resonance imaging (MRI) diagnosis of underlying finger pathology can be intimidating due to the presence of unique anatomy. The small size of the fingers and the unique orientation of the thumb compared to the fingers also introduce unique demands on the MRI system and the technologists performing the study. This article will review the anatomy pertinent to injuries at the fingers, provide protocol guidance, and discuss pathology encountered at the fingers. Although much of the encountered pathology in the fingers overlaps with adults, unique pathology to children will be highlighted when applicable.

Acute Irreducible Rotational Patellar Dislocation with Patellar Tendon Rupture: A Case Report

CASE

In this report, we present a case of acute patellar dislocation with both vertical and longitudinal rotation of the patella. As a result of rotation in the longitudinal axis, the articular surface of the patella faced outward, and the dorsal surface faced the femoral condyle. The patient underwent open reduction. One year after open reduction and soft-tissue repair, the patient had acceptable knee function and no knee pain.

CONCLUSION

This case shows how similar cases may be treated with an open reduction to properly address the patellar dislocation.

A Research and Clinical Framework for Understanding Achilles Injury in Female Collegiate Gymnasts

ABSTRACT

Gymnastics is a popular sport with a high injury rate, particularly at the collegiate level. Achilles tendon rupture is a catastrophic injury with career-changing impact. Over the last decade, there has been a growing incidence of Achilles tendon ruptures, especially in female gymnasts. Currently, neither the effects of contributing risk factors on Achilles tendon rupture nor the research frameworks to guide future intervention strategies have been well described. This article reviews the functional anatomy and mechanical properties of the Achilles tendon, provides precollegiate and collegiate intrinsic and extrinsic risk factors for Achilles tendon rupture, and proposes a research framework to address this injury from a systemic perspective. Potential clinical interventions to mitigate Achilles tendon injury are proposed based on currently available peer-reviewed evidence.

[Unity is Strength - the Underrated Strength of Tendons in Pseudoarthrosis]

Bei einem Sturz beim Fußballspielen zog sich der gesunde, damals 38 Jahre alte Patient eine skapholunäre (SL-) Bandläsion links zu. In Folge waren innerhalb von sieben Jahren insgesamt 13 operative Eingriffe nötig, bis eine vollständige Konsolidation der zuletzt angestrebten Skapho-Trapezio-Trapezoidal-(STT)-Arthrodese erreicht wurde. 5 Jahre nach der Verletzung auf der linken Seite kam es im Rahmen eines Distorsionstraumas rechts ebenfalls zu einer SL-Bandverletzung bei dem Patienten. Bei einem Stadium Geissler III wurde in einem auswärtigen Spital eine dynamische Stabilisierung mit einer ECRL-Sehnenplastik durchgeführt. Bei zunehmender SL-Dissoziation wurde aufgrund der Erfahrung mit der gleichen Problematik links schlussendlich eine Panarthrodese des rechten Handgelenkes vorgenommen.

Mechanisms of Hamstring Injury in Professional Soccer Players: Video Analysis and Magnetic Resonance Imaging Findings

OBJECTIVE

To describe the injury mechanisms and magnetic resonance imaging (MRI) findings in acute hamstring injuries of male soccer players using a systematic video analysis.

DESIGN

Descriptive case series study of consecutive acute hamstring injuries from September 2017 to January 2022.

SETTING

Two specialized sports medicine hospitals.

PARTICIPANTS

Professional male soccer players aged between 18 and 40 years, referred for injury assessment within 7 days after an acute hamstring injury, with an available video footage of the injury and positive finding on MRI.

INDEPENDENT VARIABLES

Hamstring injury mechanisms (specific scoring based on standardized models) in relation to hamstring muscle injury MRI findings.

MAIN OUTCOME MEASURES

Hamstring injury mechanism (playing situation, player/opponent behavior, movement, and biomechanical body positions) and MRI injury location.

RESULTS

Fourteen videos of acute hamstring injuries in 13 professional male soccer players were analyzed. Three different injury mechanisms were seen: mixed-type (both sprint-related and stretch-related, 43%), stretch-type (36%), and sprint-type (21%). Most common actions during injury moments were change of direction (29%), kicking (29%), and running (21%). Most injuries occurred at high or very high horizontal speed (71%) and affected isolated proximal biceps femoris (BF) (36%). Most frequent body positions at defined injury moments were neutral trunk (43%), hip flexion 45-90 degrees (57%), and knee flexion <45 degrees (93%). Magnetic resonance imaging findings showed that 79% were isolated single-tendon injuries.

CONCLUSIONS

According to a video analysis, most hamstring injuries in soccer occur during high-speed movements. Physicians should suspect proximal and isolated single-tendon-most often BF-hamstring injury, if represented injury mechanisms are seen during game play. In addition to sprinting and stretching, also mixed-type injury mechanisms occur.

A Guide to Indoor Rock Climbing Injuries

ABSTRACT

Rock climbing is an increasingly popular indoor sport with a sizable risk of overuse injuries. Yet, many medical practitioners have little familiarity with evaluating and treating climbing injuries because of the terminology, biomechanical demands, mechanisms of injury, and return to sport counseling needed, unique to the sport. This review seeks to educate practitioners on these aspects. Upper extremity injuries occur more frequently than lower extremity injuries, with finger injuries being most prevalent. Pulley injuries, consisting of rupture of the A2 or A4 annular pulleys are the most common type of injury. Other finger injuries include tenosynovitis of the flexor tendons, as well as lumbrical muscle tears. Elbow injuries occur frequently, with medial epicondylopathy being most common. Brachialis injuries are seldom seen outside of climbing. Lower-extremity injuries are typically more acute in nature, including ankle injuries from falls and knee injuries from strenuous climbing moves.

Anomalous Extensor Indicis Proprius Muscle Extending Beyond the Extensor Retinaculum: A Case Report

CASE

During dissection of the upper limb of a cadaver in preparation for a first-year anatomy course, an extensor indicis proprius (EIP) variant was discovered with its muscle belly extending distal to the extensor retinaculum and beyond what has been previously described in the literature.

CONCLUSION

EIP is commonly used as a tendon transfer for extensor pollicis longus rupture. Few anatomic variants of EIP have been reported in the literature, but such variants should be considered because of their consequences to the success of tendon transfer and potential implications for diagnosis of an otherwise unexplained mass of the wrist.

Incidence of Upper Body Injuries in Amateur Padel Players

The objectives of this study were to analyze the injuries suffered during the previous year by amateur padel players according to the characteristics of the racket, their usual volume of practice and their experience in padel. A total of 950 amateur players (X age: 31.68 years; X weight: 70.84 kg; X height: 170.9 cm) participated voluntarily, completing an ad-hoc questionnaire. The results indicated that the appearance of the injuries and their location was different according to the sex of the amateur padel players. Men had a higher incidence of muscle and ligament injuries in the shoulder, and tendon injuries in the elbow. On the other hand, women had a greater probability of having muscle injuries in the shoulder and arm, ligament injuries in the elbow and bone injuries in the wrist and elbow. In general, tendon injuries were the most common injury in padel and the shoulder and elbow were the most affected areas. Moreover, men tend to use heavy (CSR = 6.0), fiberglass or carbon (CSR = 2.1), diamond-shaped rackets (CSR = 3.2), with a hard core (CSR = 4.4) and with two or more over grips (CSR = 2.7). Women usually use less heavy (CSR = 6.0), round-shaped rackets (CSR = 4.9), with a soft core (CSR = 4.4) and with one or no over grips (CSR = 2.7). In addition, men tend to play padel more often and have been practicing for longer. In conclusion, although the risk of injury depends on many factors, we identified that the characteristics of the racket, the volume of weekly practice, the experience of the player and the gender of the player are fundamental aspects to take into account for the prevention of injuries in amateur padel players.

Efficacy of Platelet-Rich Plasma in Soft Tissue Foot and Ankle Pathology

➢

The preparation methodology for platelet-rich plasma (PRP) may have important clinical implications with varying effectiveness with leukocyte, platelet, and growth factor concentrations.

➢

There is high-quality evidence to support the superiority of PRP over corticosteroids in the case of chronic plantar fasciitis.

➢

There is moderate-quality to high-quality evidence for PRP's ability to increase tendon thickness with no capacity to decrease pain, increase function, or augment percutaneous tenotomy in Achilles tendinopathy.

➢

There is insufficient evidence to support PRP injections in the definitive treatment of Achilles tendon rupture. However, PRP may contribute to postoperative recovery after tendon rupture repair, but this requires further research.

➢

The biochemical theory supporting the clinical use of PRP must be reinforced with high-level evidence research. Based on the current literature, PRP may serve as a viable treatment method in chronic plantar fasciitis. Further high-quality, comparative studies with longer clinical follow-up are required to support recommendations for use of PRP in the treatment of Achilles tendon pathology.

Complications of Single-Incision Versus Dual-Incision Distal Biceps Repair A Systematic Review and Meta-Analysis of Comparative Studies

PURPOSE

The purpose of this study was to systematically review and analyze the current evidence in the literature to determine the relative complication rates of the singleincision versus dual-incision approach to distal biceps tendon repair.

METHODS

The literature search was performed based on the PRISMA guidelines. Cohort studies comparing the single-incision or dual-incision approach to biceps tendon repair alone were included. Clinical outcomes were compared, with all statistical analysis performed using Review Manager Version 5.3. A p-value < 0.05 was considered to be statistically significant.

RESULTS

Twelve clinical studies with varying levels of evidence (LOE I: 1, LOE II: 1, LOE III: 10) with 2,429 patients were included. Overall, there was a significantly lower rate of total complications with the dual-incision approach (16.1% vs. 23.1%, p < 0.01) and a lower rate of neurological injuries (9.1% vs. 24.1%, p < 0.01). There was a lower rate of lateral antebrachial cutaneous nerve injuries with the dual-incision approach (5.2% vs. 19.5%, p < 0.01), and superficial radial nerve injuries (2.5% vs. 4.8%, p < 0.01), but there was no significant difference in the rate of posterior interosseous nerve injuries (2.2% vs. 1.2%, p = 0.20). There was a significantly lower rate of heterotopic bone formation with the single-incision approach (1.3% vs. 2.7%, p = 0.01).

CONCLUSION

The dual-incision approach decreases the risk of total, overall postoperative complications and sensory nerve injuries following distal biceps repair. However, it has a higher risk of heterotopic bone formation.

Evaluation of the plantaris tendon: cadaver anatomy study with ultrasonographic and clinical correlation with tennis leg injury in 759 calves

OBJECTIVE

The role of the plantaris muscle (PM) in the literature is not clear. The objectives of this study were as follows: (1) to study PM at the interface between the medial gastrocnemius and soleus muscle in a cadaveric series, (2) to compare anatomic results with ultrasound (US) in the general population, and (3) to identify the potential role of the PM in the genesis of tennis leg (TL) injury.

METHODS

First, a cadaveric study was undertaken on six cadavers for descriptive and functional PM anatomy. Second, US evaluation was carried out for 670 calves in 335 subjects with no suspicion of a clinical tear in the thigh or calf muscle (group 1) and for 89 calves in 89 patients with tear symptoms (group 2). Study criteria were the presence or absence of PM tendon and the width measurement if present.

RESULTS

The PM was present in all cadavers. Traction on the tendon showed its "limited" mobility due to the connective tissue adherence mentioned with no apparent gliding of PM, promoting TL injury. In US, 37 PM were absent (4.35%) in 23 subjects. PM tendon width measurement of group 1 and group 2 was, respectively, 3.93 + / - 1.10 mm and 3.96 + / - 1.10 mm. No statistically significant differences between width measurements were found according to side (P = 0.74) or group (P = 0.69). Significant differences in width were only found between genders in group 1 (P = 0.014).

CONCLUSION

PM were absent in 4.35% population. The contraction of PM can promote tennis leg injury by increasing the shear forces at the level of the distal inter-aponeurotic region.

A Biomaterial-Based Hedging Immune Strategy for Scarless Tendon Healing

Scarring rather than regeneration, is an inevitable outcome of unbalanced amplifications of inflammation-destructive signals and atresia of the regenerative niche. However, identifying and effectively hedging against the risk of scarring and realizing the conversion of regenerative cues remain difficult. In this work, a hedging immune strategy based microfibrous membrane (Him-MFM), by tethering distearoyl phosphoethanolamine layer-supported copoly(lactic/glycolic acid) electrospun fibers with identified CD11b⁺ /CD68⁺ scarring subpopulation membranes in the immune landscape after tendon injury to counterweigh tissue damage, is reported. Him-MFM, carrying relevant risk receptors is shown to shift high type I biased polarization, alleviate apoptosis and metabolic stress, and mitigate inflammatory tenocyte response. Remarkably, the hedging immune strategy reverses the damaged tendon sheath barrier to the innate IL-33 secretory phenotype by 4.36 times and initiates the mucous-IL-33-Th2 axis, directly supplying a transient but obligate regenerative niche for sheath stem cell proliferation. In murine flexor tendon injury, the wrapping of Him-MFM alleviates pathological responses, protects tenocytes in situ, and restores hierarchically arranged collagen fibers covered with basement membrane, and is structurally and functionally comparable to mature tendons, demonstrating that the hedging immunity is a promising strategy to yield regenerative responses not scarring.

Is a Steroid Injection in Both Compartments More Effective than an Injection in the Extensor Pollicis Brevis Subcompartment Alone in Patients with de Quervain Disease? A Randomized, Controlled Trial

BACKGROUND

Ultrasonography (US)-guided steroid injections can improve the accuracy of injection in patients with de Quervain disease, especially in those with an intracompartmental septum. Although the main lesion of de Quervain disease in patients with a septum is a stenosing tenosynovitis of the extensor pollicis brevis (EPB), no report we know of has compared injection into the EPB subcompartment with an injection into both the abductor pollicis longus (APL) and EPB subcompartments. In this randomized trial, we compared the results of US-guided steroid injections targeting both subcompartments and the EPB subcompartment alone in patients with de Quervain disease.

QUESTIONS/PURPOSES

(1) Do patients who receive a steroid injection in the EPB subcompartment alone have lower pain scores at 6 weeks and at 3 months after US-guided injection compared with patients who receive an injection in both subcompartments? (2) Do patients who receive a steroid injection in the EPB subcompartment alone experience fewer steroid injection-related complications than patients who receive an injection in both subcompartments?

METHODS

A randomized controlled study was performed at a single center between August 2018 and March 2021. Patients with a diagnosis of de Quervain disease and with a complete intracompartmental septum between the APL and the EPB tendons were included. In total, 112 patients had a diagnosis of de Quervain disease during the study period. Definite, complete subcompartmentalization was seen in 50 patients. Patients were randomly assigned to US-guided injections targeting both subcompartments (n = 25) or the EPB subcompartment alone (n = 25). There were no between-group differences in age, gender, affected wrist, or disease duration, and all patients had US evidence of tendinosis of the EPB, with or without tendinosis of the APL. Although 33% of patients (16 of 48) showed tendinosis of the APL, no patient showed tendinosis of the APL alone. In all patients, a dorsal-to-palmar side injection of 0.5 mL of 2% lidocaine and 0.5 mL of triamcinolone acetonide (40 mg/mL) was administered by two experienced hand surgeons. In the both-subcompartments group, US-guided injections were performed in each of the APL and EPB subcompartments. In the EPB subcompartment group, US-guided injections were administered in the EPB subcompartment only. All patients underwent the same protocol after the procedure. Four percent (n = 2, 1 in each group) of patients were excluded after randomization because their pain level was not registered. Pre- and postinjection clinical outcome assessments were completed by orthopaedic surgery residents not involved in patient management. Patients were regularly examined at baseline, 6 weeks, and 3 months to evaluate the intensity of pain. We assessed pain by the VAS score, where 0 indicated no pain and 100 the most pain. At baseline, the VAS score was 67 ± 14 in the both-subcompartment group and 67 ± 16 in the EPB subcompartment group (mean difference 0.17 [95% CI -8.45 to 8.82]; p = 0.97). Complications related to the steroid injection, including numbness, tendon rupture, and skin hypopigmentation, were also recorded at final follow-up examinations. To determine statistical power, the VAS score for pain at 6 weeks after the injection was used as the primary outcome variable. The minimum clinically important difference for the VAS score was deemed to be 20 mm, and we estimated an SD of 23. A sample size calculation indicated that a sample of 21 patients per group would provide 80% power to detect an effect of this size between the groups at the p = 0.05 level using a t-test.

RESULTS

There were no differences in the VAS scores between the both-subcompartment group and the EPB group at 6 weeks (10 ± 6 versus 10 ± 7, mean difference -0.08 [95% CI -4.08 to 3.91]; p = 0.97). The same was true at 12 weeks (12 ± 13 versus 11 ± 15, mean difference 0.38 [95% CI -7.74 to 8.49]; p = 0.09). No adverse events related to treatment (such as tendon rupture, infections, and numbness) occurred in either group. However, skin hypopigmentation occurred at the final follow-up examination in both groups. The proportion of patients experiencing skin hypopigmentation in the EPB subcompartment group was lower than in the both-subcompartment group (33% [8 of 24] versus 67% [16 of 24]; odds ratio 0.25 [95% CI 0.08 to 0.83]; p = 0.02).

CONCLUSION

Our data suggest that a US-guided steroid injection targeting the EPB subcompartment alone is as effective in terms of pain reduction as targeting both subcompartments in patients with de Quervain disease who have complete septation. Furthermore, an injection targeting the EPB subcompartment alone can reduce the dose of steroids used, perhaps thereby decreasing complications related to steroid injections. We recommend using only single-compartment injections in this context, even among patients with an intracompartmental septum.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Biceps tenotomy or tenodesis in association with rotator cuff repair: is there an influence on functional results? A retrospective cohort study

BACKGROUND

Instability or tears of the long head of the biceps tendon (LHBT) may be present in more than 35% of rotator cuff repairs (RCR).

OBJECTIVE

To compare clinical results from patients undergoing arthroscopic RCR, according to the procedure performed at the LHBT.

DESIGN AND SETTING

Retrospective cohort study designed at the shoulder and elbow clinic of Instituto de Ortopedia e Traumatologia, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo, Brazil.

METHODS

Functional results among patients were compared using the American Shoulder and Elbow Surgeons (ASES) and University of California Los Angeles (UCLA) scales, according to the LHBT approach adopted: no procedure, tenotomy or tenodesis.

RESULTS

We evaluated 306 shoulders (289 patients): 133 underwent no procedure at the LHBT, 77 tenotomy and 96 tenodesis. The ASES scale at 24 months showed no difference (P = 0.566) between the groups without LHBT procedure (median 90.0; interquartile range, IQR 29), tenotomy (median 90.0; IQR 32.1) or tenodesis (median 94.4; IQR 22.7); nor did the UCLA scale (median 33; IQR 7 versus median 31; IQR 8 versus median 33; IQR 5, respectively, P = 0.054). The groups differed in the preoperative functional assessment according to the ASES and UCLA scale, such that the tenodesis group started from higher values. However, there was no difference in pre and postoperative scores between the groups.

CONCLUSION

Tenodesis or tenotomy of the LHBT, in the sample analyzed, did not influence the clinical results from RCR, as assessed using the ASES and UCLA scales.