Multi-omics analysis of human tendon adhesion reveals that ACKR1-regulated macrophage migration is involved in regeneration.

Tendon adhesion is a common complication after tendon injury with the development of accumulated fibrotic tissues without effective anti-fibrotic therapies, resulting in severe disability. Macrophages are widely recognized as a fibrotic trigger during peritendinous adhesion formation. However, different clusters of macrophages have various functions and receive multiple regulation, which are both still unknown. In our current study, multi-omics analysis including single-cell RNA sequencing and proteomics was performed on both human and mouse tendon adhesion tissue at different stages after tendon injury. The transcriptomes of over 74 000 human single cells were profiled. As results, we found that SPP1+ macrophages, RGCC+ endothelial cells, ACKR1+ endothelial cells and ADAM12+ fibroblasts participated in tendon adhesion formation. Interestingly, despite specific fibrotic clusters in tendon adhesion, FOLR2+ macrophages were identified as an antifibrotic cluster by in vitro experiments using human cells. Furthermore, ACKR1 was verified to regulate FOLR2+ macrophages migration at the injured peritendinous site by transplantation of bone marrow from Lysm-Cre;R26RtdTomato mice to lethally irradiated Ackr1-/- mice (Ackr1-/- chimeras; deficient in ACKR1) and control mice (WT chimeras). Compared with WT chimeras, the decline of FOLR2+ macrophages was also observed, indicating that ACKR1 was specifically involved in FOLR2+ macrophages migration. Taken together, our study not only characterized the fibrosis microenvironment landscape of tendon adhesion by multi-omics analysis, but also uncovered a novel antifibrotic cluster of macrophages and their origin. These results provide potential therapeutic targets against human tendon adhesion.

The current status of various preclinical therapeutic approaches for tendon repair.

Tendons are fibroblastic structures that link muscle and bone. There are two kinds of tendon injuries, including acute and chronic. Each form of injury or deterioration can result in significant pain and loss of tendon function. The recovery of tendon damage is a complex and time-consuming recovery process. Depending on the anatomical location of the tendon tissue, the clinical outcomes are not the same. The healing of the wound process is divided into three stages that overlap: inflammation, proliferation, and tissue remodeling. Furthermore, the curing tendon has a high re-tear rate. Faced with the challenges, tendon injury management is still a clinical issue that must be resolved as soon as possible. Several newer directions and breakthroughs in tendon recovery have emerged in recent years. This article describes tendon injury and summarizes recent advances in tendon recovery, along with stem cell therapy, gene therapy, Platelet-rich plasma remedy, growth factors, drug treatment, and tissue engineering. Despite the recent fast-growing research in tendon recovery treatment, still, none of them translated to the clinical setting. This review provides a detailed overview of tendon injuries and potential preclinical approaches for treating tendon injuries.

In vivo study on the repair of rat Achilles tendon injury treated with non-thermal atmospheric-pressure helium microplasma jet.

Non-thermal atmospheric-pressure plasma (NTAPP) has been widely studied for clinical applications, e.g., disinfection, wound healing, cancer therapy, hemostasis, and bone regeneration. It is being revealed that the physical and chemical actions of plasma have enabled these clinical applications. Based on our previous report regarding plasma-stimulated bone regeneration, this study focused on Achilles tendon repair by NTAPP. This is the first study to reveal that exposure to NTAPP can accelerate Achilles tendon repair using a well-established Achilles tendon injury rat model. Histological evaluation using the Stoll's and histological scores showed a significant improvement at 2 and 4 weeks, with type I collagen content being substantial at the early time point of 2 weeks post-surgery. Notably, the replacement of type III collagen with type I collagen occurred more frequently in the plasma-treated groups at the early stage of repair. Tensile strength test results showed that the maximum breaking strength in the plasma-treated group at two weeks was significantly higher than that in the untreated group. Overall, our results indicate that a single event of NTAPP treatment during the surgery can contribute to an early recovery of an injured tendon.

[Effectiveness of Kirschner wire fixation for proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of flexor digitorum tendon].

Objective: To explore the mechanism, surgical method, and effectiveness of proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of the flexor digitorum tendon. Methods: A retrospective analysis was conducted on the clinical data of 4 patients with proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of flexor digitorum tendon admitted between May 2018 and September 2022. The patients were all male, the age ranged from 26 to 52 years, with an average of 33 years. The injured fingers included 1 case of middle finger and 3 cases of ring finger. The causes of injury were rock climbing of 2 cases and carrying heavy objects of 2 cases. Preoperative anteroposterior and lateral X-ray films and CT examination of the fingers showed a lateral avulsion fracture of the proximal phalanx, with a fracture block length of 15-22 mm and a width of 3-5 mm. The total active range of motion (TAM) of the injured finger before operation was (148.75±10.11)°. The grip strength of the middle and ring fingers was (15.50±2.88) kg, which was significantly lower than that of the healthy side (50.50±7.93) kg ( t=-8.280, P<0.001). The time from injury to operation was 2-7 days, with an average of 3.5 days. One Kirschner wire with a diameter of 1.0 mm was used for direct fixation through the fracture block, while two Kirschner wires with a diameter of 1.0 mm were used for compression fixation against the fracture block. The fracture healing was observed, and the TAM of the injured finger and the grip strength of the middle and ring fingers were measured. The finger function was evaluated according to the upper limb functional assessment trial standards of the Chinese Medical Association Hand Surgery Society. Results: The incisions all healed by first intention after operation. All patients were followed up 6-28 months, with an average of 19 months. X-ray films showed that all avulsion fractures of proximal phalanx reached bony union, and the healing time ranged from 4 to 8 weeks, with an average of 4.6 weeks. At last follow-up, the grip strength of the middle and ring fingers was (50.50±7.76) kg, which significantly improved when compared with preoperative one ( t=-8.440, P<0.001). The TAM of the injured finger reached (265.50±2.08)°, and there was a significant difference when compared with preoperative one ( t=-21.235, P<0.001). According to the upper limb functional assessment trial standards of the Chinese Medical Association Hand Surgery Society, the finger function was all evaluated as excellent in 4 cases. Conclusion: Using Kirschner wire fixation through bone blocks and external compression fixation of bone blocks for treating proximal phalangeal bone avulsion fracture caused by A2 circular trochlear injury of the flexor digitorum tendon can achieve good effectiveness.

The learning curve for minimally invasive Achilles repair using the "lumbar puncture needle and oval forceps" technique.

INTRODUCTION: An acute Achilles tendon rupture represents a common tendon injury, and its operative methods have been developed over the years. This study aimed to quantify the learning curve for the minimally invasive acute Achilles tendon rupture repair. METHODS: From May 2020 to June 2022, sixty-seven patient cases who received minimally invasive tendon repair were reviewed. Baseline data and operative details were collected. The cumulative summation (CUSUM) control chart was used for the learning curve analyses. Achilles tendon rupture score (ATRS), American Orthopedic Foot and Ankle Society (AOFAS) ankle/hindfoot score, and visual analog scale (VAS) at 3/6/9/12 months were calculated to assess the clinical outcomes. RESULTS: Thirty-six cases underwent at least a year of follow up and were enrolled in this study. The gender ratio and average age were 80.5% and 32.5 years. The linear equation fitted well (R2 = 0.95), and CUSUM for operative time peaked in the 12th case, which was divided into the learning phase (n = 12) and master phase (n = 24). No significant difference was detected between the two groups in clinical variables, except for the operative time (71.1 ± 13.2 min vs 45.8 ± 7.2 min, p = 0.004). Moreover, we detected one case with a suture reaction and treated it properly. CONCLUSION: Minimally invasive Achilles repair provides an opportunity for early rehabilitation. Notably, the learning curve showed that the "lumbar puncture needle and oval forceps" technique was accessible to surgeons.

Extensor tendon rupture and preoperative mri confirmations of suture anchor prolapse: a case report and literature review.

BACKGROUND: While suture anchors are widely used in medical procedures for their advantages, they can sometimes lead to complications, including anchor prolapse. This article presents a unique case of suture anchor prolapse at the base of the distal phalanx of the little finger after extensor tendon rupture reconstruction surgery. CASE PRESENTATION: A 35-year-old male, underwent extensor tendon rupture reconstruction using a non-absorbable suture anchor. After seven years the patient visited our outpatients complaining of stiffness, pain, and protrusion at the surgical site. Initial X-ray imaging suggested suggesting either a fracture of the distal phalanx or tendon adhesion but lacked a definitive diagnosis. Subsequent magnetic resonance imaging (MRI) revealed bone connectivity between the middle and distal phalanges with irregular signal shadow and unclear boundaries while maintaining a regular finger shape. MRI proved superior in diagnosing prolapsed suture anchors, marking the first reported case of its kind. Surgical intervention confirmed MRI findings. CONCLUSIONS: Suture anchor complications, such as prolapse, are a concern in medical practice. This case underscores the significance of MRI for accurate diagnosis and the importance of tailored surgical management in addressing this uncommon complication.

Achilles Tendon Rupture.

There are many high-level studies comparing nonoperative treatment, open repair, and minimally invasive repair for Achilles tendon ruptures. This article summarizes the most up-to-date literature comparing these treatment options. The authors' preferred protocol for nonoperative treatment is discussed. Preferred techniques for open repair and chronic Achilles repair are discussed with reference to the literature.

The effect of papaverine on tendon healing and adhesion in rats following Achilles tendon repair.

OBJECTIVES: The study aimed to examine the histopathological and biomechanical effects of papaverine administered intraperitoneally and locally on Achilles tendon healing in a rat model. MATERIALS AND METHODS: Forty-eight adult male Sprague-Dawley rats (range, 300 to 400 g) were used in this study conducted between October and November 2022. The rats were divided into three groups, with each group further subdivided into two for sacrifice on either the 15th (early period) or 30th (late period) day after surgery. The first (control) group received no treatment following Achilles tendon repair, while papaverine was intraperitoneally administered every other day for 10 days in the second group and locally in the third group after surgery. On the 15th and 30th days, the rats were sacrificed, and their Achilles tendons were subjected to biomechanical testing and histopathological evaluation. RESULTS: Histopathologically, there were no significant differences among the groups on the 15th day. However, on the 30th day, the locally applied papaverine group exhibited superior histopathological outcomes compared to the control group (p<0.05). Concerning the highest tensile strength values before rupture, the biomechanical assessment showed that the group receiving local papaverine treatment in the early period and both the group with systemic papaverine treatment and the one with local papaverine treatment in the late period displayed a statistically significant advantage compared to the control group (p<0.05). CONCLUSION: Locally administered papaverine has positive biomechanical effects in the early period and exhibits a positive correlation both histopathologically and biomechanically in the late period. Novel therapeutic options may be provided for patients through these findings.

Biomechanical strength of triceps tendon repairs: systematic review and meta-regression analysis of human cadaveric studies.

PURPOSE: It is unclear which triceps tendon repair constructs and techniques produce the strongest biomechanical performance while minimizing the risk of gap formation and repair failure. We aimed to determine associations of construct and technique variables with the biomechanical strength of triceps tendon repairs. PubMed, Embase, Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov were systematically searched for peer-reviewed studies on biomechanical strength of triceps tendon repairs in human cadavers. 6 articles met the search criteria. Meta-regression was performed on the pooled dataset (123 specimens). Outcomes of interest included gap formation, failure mode, and ultimate failure load. Covariates were fixation type; number of implants; and number of sutures. Stratification by covariates was performed. We found no association between fixation type and ultimate failure load; however, suture anchor fixation was associated with less gap formation compared with transosseous direct repair (ß = - 1.1; 95% confidence interval [CI]:- 2.2, - 0.04). A greater number of implants was associated with smaller gap formation (ß = - 0.77; 95% CI: - 1.3, - 0.28) while a greater number of sutures was associated with higher ultimate failure load ( ß= 3; 95% CI: 21, 125). In human cadaveric models, the number of sutures used in triceps tendon repairs may be more important than the fixation type or number of implants for overall strength. If using a transosseous direct repair approach to repair triceps tendon tears, surgeons may choose to use more sutures in their repair in order to balance the risk of larger gap formation when compared to indirect repair techniques. LEVEL OF EVIDENCE: Level III.

[Clinical effects of early rehabilitation treatment after repair surgery of skin and soft tissue defects accompanied by extensor tendon injury on the back of hand].

Objective: To explore the clinical effects of early rehabilitation treatment after repair surgery of skin and soft tissue defects accompanied by extensor tendon injury on the back of hand. Methods: This study was a retrospective non-randomized controlled study. From February 2015 to February 2023, 24 patients (15 males and 9 females, aged 12-55 years) with skin and soft tissue defects accompanied by extensor tendon injury on the back of hand, who met the inclusion criteria and were repaired with flap transplantation and tendon grafting or tendon anastomosis, were admitted to the First Affiliated Hospital of Air Force Medical University. According to different intervention time for postoperative rehabilitation treatment of patients, the patients were divided into conventional rehabilitation group and early rehabilitation group, with 12 cases in each group. Patients in early rehabilitation group received rehabilitation treatment immediately after surgery under the rehabilitation guidance of specialized rehabilitation physicians based on the characteristics of different postoperative periods. Patients in conventional rehabilitation group began rehabilitation treatment from the third week after surgery, and their rehabilitation treatment was the same as that of patients in early rehabilitation group from the second week after surgery. The patients in 2 groups were treated in the hospital until the sixth week after surgery. The occurrence of flap vascular crisis and tendon rupture were observed within 6 weeks after surgery. After 6 weeks of surgery, the manual muscle test was used to measure the pinching force between the index finger and thumb, lateral pinching force, three-point pinching force, and grip force of the affected hand; the total action motion method was used to evaluate the finger joint range of motion of the affected hand, and the excellent and good ratio was calculated; the Carroll upper extremity function test was used to score and rate the function of the affected hand. Results: Within 6 weeks after surgery, only 1 patient in conventional rehabilitation group suffered from venous crisis, and the flap survived after the second surgical exploration and anastomosis of blood vessels; there was no occurrence of tendon rupture in patients of 2 groups. After 6 weeks of surgery, there were no statistically significant differences in pinching force between the index finger and thumb, lateral pinching force, three-point pinching force, or grip force of the affected hand between the two groups of patients (P>0.05); the excellent and good ratio of the finger joint range of motion of the affected hand of patients in early rehabilitation group was 11/12, which was higher than 7/12 in conventional rehabilitation group, but there was no statistically significant difference (P>0.05); the affected hand function score of patients in early rehabilitation group was 90±6, which was significantly higher than 83±8 in conventional rehabilitation group (t=2.41, P<0.05); the function rating of the affected hand of patients in early rehabilitation group was obviously better than that in conventional rehabilitation group (Z=2.04, P<0.05). Conclusions: Early rehabilitation treatment for patients with skin and soft tissue defects accompanied by extensor tendon injury on the back of hand after repair surgery can improve hand function, but it would not increase surgery related complications, which is worthy of clinical promotion and application.

Surgical treatment of patellar tendon rupture after total knee arthroplasty with a double-row repair method using the hamstring tendons: A novel technique with functional results.

BACKGROUND: Patellar tendon rupture (PTR) is extremely rare but serious complication after primary or revision total knee arthroplasty. Due to the serious failure rates of end-to-end repair techniques, various augmentation techniques have been described. In this study, the results of patients with PTR after reconstruction using our own technique with semitendinosus (ST) and gracilis tendons taken from the affected side were evaluated retrospectively. METHODS: A total of 14 patients, whose diagnosis was made based on physical examination and clinical findings, and supported radiologically (ultrasonography), were included in the study. In these patients, reconstruction was performed using double-row repair technique with the ST and gracilis tendons. Active-passive knee joint range of motion, active knee extension loss, and the Caton-Deschamps index at preoperative and final follow-up visits were compared. Tegner-Lysholm knee score and Kujala score were used to evaluate functional results. RESULTS: In 14 patients (8 women and 6 men) with a mean age of 68.1 years, the median time between injury and surgery was 6.6 weeks. In all patients, the rupture was in the distal part of the patellar tendon. While the median preoperative Caton-Deschamps index was 1.8, the postoperative median value was found to be 1.25 after an average follow-up of 3.8 years (P = .014). The median preoperative knee extension loss decreased from 25° to 5° postoperatively. Tegner-Lysholm knee score and Kujala score of the patients at their last follow-up were significantly increased (P < .01). CONCLUSION: For PTR developing after total knee arthroplasty, the double-row reconstruction technique with ST and gracilis tendons is effective.

Recent Advances in the Use of Stem Cells in Tissue Engineering and Adjunct Therapies for Tendon Reconstruction and Future Perspectives.

Due to their function, tendons are exposed to acute injuries. This type of damage to the musculoskeletal system represents a challenge for clinicians when natural regeneration and treatment methods do not produce the expected results. Currently, treatment is long and associated with long-term complications. In this review, we discuss the use of stem cells in the treatment of tendons, including how to induce appropriate cell differentiation based on gene therapy, growth factors, tissue engineering, proteins involved in regenerative process, drugs and three-dimensional (3D) structures. A multidirectional approach as well as the incorporation of novel components of the therapy will improve the techniques used and benefit patients with tendon injuries in the future.

Acute Patellar Tendon Ruptures: An Update on Management.

Patellar tendon ruptures can be debilitating injuries. When incomplete, partial tears can be managed nonsurgically with immobilization and progressive rehabilitation. Although complete ruptures remain a relatively uncommon injury, they portend a high level of morbidity. Ruptures typically result from an acute mechanical overload to the extensor mechanism, such as with forced quadriceps contraction and knee flexion. However, chronically degenerated tendons are also predisposed to failure from low-energy injuries. Diagnosis can often be made clinically with recognition of a palpable defect to the tendon, localized patellar tendon tenderness, and inability to actively extend the knee. Diagnosis and surgical planning can be established with radiograph, ultrasonography, or magnetic resonance imaging. Surgical repair is the mainstay of treatment, and there have been many recent advances in repair technique, optimal reconstruction strategies, and supplemental fixation. Time to surgery for complete tears remains the most important prognosticator for success. Direct primary repair can be completed with transosseous tunnels, suture anchor repair, or end-to-end repair. Tendon reconstruction can be achieved with or without mechanical or biologic augments. Rehabilitation programs vary in specifics, but return to sport can be expected by 6 months postoperatively.

Engineering Tendon Assembloids to Probe Cellular Crosstalk in Disease and Repair.

Tendons enable locomotion by transferring muscle forces to bones. They rely on a tough tendon core comprising collagen fibers and stromal cell populations. This load-bearing core is encompassed, nourished, and repaired by a synovial-like tissue layer comprising the extrinsic tendon compartment. Despite this sophisticated design, tendon injuries are common, and clinical treatment still relies on physiotherapy and surgery. The limitations of available experimental model systems have slowed the development of novel disease-modifying treatments and relapse-preventing clinical regimes. In vivo human studies are limited to comparing healthy tendons to end-stage diseased or ruptured tissues sampled during repair surgery and do not allow the longitudinal study of the underlying tendon disease. In vivo animal models also present important limits regarding opaque physiological complexity, the ethical burden on the animals, and large economic costs associated with their use. Further, in vivo animal models are poorly suited to systematic probing of drugs and multicellular, multi-tissue interaction pathways. Simpler in vitro model systems have also fallen short. One major reason is a failure to adequately replicate the three-dimensional mechanical loading necessary to meaningfully study tendon cells and their function. The new 3D model system presented here alleviates some of these issues by exploiting murine tail tendon core explants. Importantly, these explants are easily accessible in large numbers from a single mouse, retain 3D in situ loading patterns at the cellular level, and feature an in vivo-like extracellular matrix. In this protocol, step-by-step instructions are given on how to augment tendon core explants with collagen hydrogels laden with muscle-derived endothelial cells, tendon-derived fibroblasts, and bone marrow-derived macrophages to substitute disease- and injury-activated cell populations within the extrinsic tendon compartment. It is demonstrated how the resulting tendon assembloids can be challenged mechanically or through defined microenvironmental stimuli to investigate emerging multicellular crosstalk during disease and injury.

Effects of evidence-based nursing care interventions on wound pain and wound complications following surgery for finger tendon injury.

We conducted this study aimed to examine the impact of evidence-based nursing interventions on postoperative wound pain and complications after surgery for finger tendon injury. A total of 86 patients treated for finger tendon injuries at our hospital from January 2021 to October 2023 were selected and randomly divided into an experimental group and a control group. The control group received conventional nursing care, while the experimental group received evidence-based nursing interventions. The study compared the postoperative wound pain intensity, incidence of complications and patient satisfaction with nursing care between the two groups. The analysis revealed that compared with conventional care, evidence-based nursing interventions significantly reduced the level of wound pain (p = 0.034) and the incidence of complications (4.65% vs. 18.60%, p = 0.043). It also increased patient satisfaction with the nursing care (97.67% vs. 83.72%, p = 0.026). The study indicates that the application of evidence-based nursing interventions for patients with finger tendon injuries can reduce postoperative wound pain, decrease the incidence of complications and enhance patient satisfaction with nursing care.

Comparison of Clinical Efficacy between Arthroscopic and Open Surgery for Ogden Type 1-2 Peroneal Tendon Dislocation.

OBJECTIVE: While the incidence of peroneal tendon dislocation (PTD) is relatively low, it is frequently underdiagnosed in clinical practice, and the misdiagnosis or improper treatment of this condition may lead to a decline in patients' quality of life. Currently, the surgical treatment options for PTD mainly include open and arthroscopic surgery. However, in order to evaluate the advantages and disadvantages of these two surgical approaches, further comparative research is needed. Therefore, the aim of this study is to investigate the early clinical outcomes of arthroscopic and open surgery in the treatment of Ogden type 1-2 PTD. METHODS: We conducted a comprehensive analysis of 46 patients diagnosed with PTD who underwent surgery at our institution between January 2017 and January 2023. The patients were divided into two groups: the open surgery group, consisting of 26 cases, and the arthroscopic surgery group, consisting of 20 cases. To compare the effectiveness of the surgical approach, we evaluated several parameters, including the integrity of the superior peroneal retinaculum on MRI images, functional scores, pain interference scores, and ankle eversion muscle strength. These assessments are conducted respectively before the surgery, 1 month after the surgery, 3 months after the surgery, and at the final follow-up for each group of patients (at least 6 months post-surgery). Demographics and intergroup comparisons of the two groups of data were analyzed by t-test or the Mann-Whitney U test. Intragroup comparisons of the two groups of data were analyzed by one-way analysis of variance (ANOVA) or the Kruskal-Wallis test, followed by post hoc multiple comparisons. RESULTS: In the intragroup comparisons, both the arthroscopic surgery and the open surgery group demonstrated significant improvement in functional scores, pain interference scores, muscle strength, and MRI findings at the final follow-up postoperatively (p < 0.01). However, the open surgery group exhibited significant improvements in these outcomes at the final follow-up, while the arthroscopic surgery group showed significant improvement at 3 months postoperatively. In intergroup comparisons, the arthroscopic surgery group outperformed the open surgery group in functional scores, pain interference scores, and muscle strength 3 months after the surgery, with statistically significant differences (p < 0.01). CONCLUSION: Arthroscopic surgery offers advantages in early clinical outcomes, such as pain relief, function, and muscle strength improvement. However, over time, both approaches provide similar results regarding effectiveness.

No difference in operative time, outcomes, cosmesis, or return to activity and/or sport after minimally invasive versus open repair of primary Achilles ruptures: a retrospective review.

PURPOSE: To compare clinical outcomes and the rate of return to sport among patients that have undergone minimally invasive repair versus open approach of an acute Achilles tendon rupture. METHODS: Patients who underwent surgical repair of acute Achilles tendon rupture at a single urban academic institution from 2017 to 2020 with minimum 2-year follow-up were reviewed retrospectively. Preinjury sport participation and preinjury work activity information, the Achilles tendon Total Rupture Score (ATRS), the Tegner Activity Scale, Patient-Reported Outcomes Measurement Information System for mobility and pain interference were collected. RESULTS: In total, 144 patients were initially included in the study. Of these, 63 patients were followed with a mean follow-up of 45.3 ± 29.2 months. The mean operative time did not significantly differ between groups (p = 0.938). Patients who underwent minimally invasive repair returned to sport at a rate of 88.9% at a mean of 10.6 ± 5.8 months, compared to return rate of open procedures of 83.7% at 9.5 ± 5.5 months. There were no significant differences in ATRS (p = 0.246), Tegner (p = 0.137) or VAS pain (p = 0.317) scores between groups. There was no difference in cosmetic satisfaction between PARS and open repair groups (88.4 vs. 76.0; p = 0.244). CONCLUSION: Patients who underwent minimally invasive repair of acute Achilles tendon ruptures demonstrate no significant differences with respect to cosmesis, operative time, patient-reported outcomes and the rate and level of return to activities when compared to an open approach. LEVEL OF EVIDENCE: III.

Construct validation of a novel synthetic tendon model used for assessing surgeon performance in a simulated core suture tendon repair technique.

BACKGROUND: The strength of tendon repair is dependent on the quality of the core suture. Organic and synthetic materials have been used to simulate tendon repair for training; however, no model has undergone construct validation. OBJECTIVES: To determine the construct validity of a novel synthetic tendon repair model. METHODS: Synthetic silicone tendon models were used to simulate adult Achilles tendon (AT) and digital flexor tendon (FT). Participants were categorised into novice, intermediate, and advanced groups based on prior surgical experience. Participants repaired tendons using the modified Kessler technique. A validated motion analysis system was used to measure the duration, path length, and movement count during the simulated task. A global rating score was also used to assess the performance. RESULTS: All participants in the novice (n = 12), intermediate (n = 8) and advanced (n = 11) groups completed the tasks. The results (mean±standard deviation) were duration (872 ± 335, 492 ± 257 and 357 ± 40 s), path length (9493 ± 3173, 6668 ± 1740 and 4672 ± 1228 cm), movement count (4974 ± 673, 4228 ± 259 and 3962 ± 69) and global rating (39 ± 13, 61 ± 14, 81 ± 5), respectively. The Kruskal-Wallis test was significant for all outcome measures (p < 0.01). Significant differences in duration and movement count were identified post-hoc in the AT model for each experience group (p < 0.05), and between novice and intermediate participants for FT repair (p < 0.04). Global rating was significantly different between all groups and was highly correlated with motion metrics (p < 0.01). CONCLUSION: The results support construct validity of this novel simulated tendon repair model. The global rating scores may allow wide utility of this simulation. This model provides a valid and safe environment for surgical trainees to practice tendon repair with several cost, ethical and logistical benefits over animal tendon use. 248/250.

Stem cells and platelet-rich plasma for the treatment of naturally occurring equine tendon and ligament injuries: a systematic review and meta-analysis.

BACKGROUND: Platelet-rich plasma (PRP) and mesenchymal stromal or stem cells (MSCs) have been investigated as treatments for equine tendon and ligament injuries, but little consensus exists on the efficacy of these treatments. The study sought to evaluate the efficacy of PRP and MSC treatments by systematic review and meta-analysis. METHODS: A systematic review was performed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Inclusion criteria required an original, peer-reviewed study where horses were administered MSCs or PRP (or both), and a comparator group was described. Studies were assessed for risk of bias and study quality. Random effects meta-analysis with inverse variance weighting was used to calculate pooled estimates of the ORs for the primary outcomes of return to performance and reinjury. RESULTS: The search criteria identified 764 unique studies, and 21 studies met the inclusion criteria for the systematic review. Seventeen studies were further assessed for the primary outcomes of return to performance and reinjury rate within a meta-analysis. Meta-analyses revealed no increase in the likelihood of a return to performance with any of the biologic treatments. However, MSCs and MSCs administered concurrently with PRP provide a reduced risk of reinjury. CLINICAL RELEVANCE: The current study identified a decrease in reinjury rate in horses administered MSCs or a combination of MSCs and PRP for tendinopathy and desmopathy. However, results should be interpreted with consideration of the heterogeneity of findings, poor study quality, and high risk of bias in the majority of studies.

Modified gastro-soleus turn-down flap for chronic or neglected achilles tendon ruptures.

BACKGROUND: Achilles' tendon chronic rupture is a common entity that is usually misdiagnosed or mistreated. Hence, she was presented to us later or with complications affecting her gait. Surgical resection is needed to either bridge the gap or reinforce the strength of the tendon repair. OBJECTIVES: Our study's goal was to assess the clinical results of repairing chronic Achilles' tendon lesions employing the middle segment of the proximal portion of the tendon (gastro-soleus), as a turn-down flap. METHODS: Our prospective interventional single arm study included 18 patients with chronic Achilles' tendon rupture attending at Al-Azhar university hospitals in Cairo, Egypt from May 2020 to April 2023. Diagnosis of the patients was confirmed by radiographic and clinical investigations. They were all treated with the same open reconstruction procedure using a modified GSF. The average follow-up was 12 months. The results of this study were assessed by the Achilles tendon rupture score (ATRS), American Orthopedic Foot and Ankle Society (AOFAS) score, and capacity to perform repeated heel raises on the affected side. RESULTS: The mean operative time was 72.77 min. The median (IQR) time of reconstruction was 10 (8-12) after the injury. The median (IQR) length of flab was 4.5 (4.3-5) 9 (Table 2). No intraoperative complications occurred. The typical follow-up period was 12 months (6-18 months). In terms of the ATRS, we found a significant reduction from 82.8 ± 3 preoperatively to 20.8 ± 6.7 at 12 months postoperatively (P value = 0.001). As regards the AOFAS score, it was increased from 49.5 ± 10 preoperatively to 83.8 ± 8.5 12 months postoperatively (P = 0.001). In terms of the post operative complications, there was no re-rupture. Two patients experienced superficial wound infection which improved with daily dressing and antibiotics. Additionally, two patients had slight ankle stiffness four months after the operation, which improved after programmed rehabilitation at the sixth month. CONCLUSION: The modified GSTF is a simple, safe, well-tolerated and effective method of treatment with excellent functional results and greater patient content.