Leptin, an adipocyte‐derived cytokine associated with bone metabolism, is believed to play a critical role in the pathogenesis of heterotopic ossification (HO). The effect and underlying action ...mechanism of leptin were investigated on osteogenic differentiation of tendon‐derived stem cells (TDSCs) in vitro and the HO formation in rat tendons. Isolated rat TDSCs were treated with various concentrations of leptin in the presence or absence of mTORC1 signaling specific inhibitor rapamycin in vitro. A rat model with Achilles tenotomy was employed to evaluate the effect of leptin on HO formation together with or without rapamycin treatment. In vitro studies with TDSCs showed that leptin increased the expression of osteogenic biomarkers (alkaline phosphatase, runt‐related transcription factor 2, osterix, osteocalcin) and enhanced mineralization of TDSCs via activating the mTORC1 signal pathway (as indicated by phosphorylation of p70 ribosomal S6 kinase 1 and p70 ribosomal S6). However, mTORC1 signaling blockade with rapamycin treatment suppressed leptin‐induced osteogenic differentiation and mineralization. In vivo studies showed that leptin promoted HO formation in the Achilles tendon after tenotomy, and rapamycin treatment blocked leptin‐induced HO formation. In conclusion, leptin can promote TDSC osteogenic differentiation and heterotopic bone formation via mTORC1 signaling in both vitro and vivo model, which provides a new potential therapeutic target for HO prevention.
Leptin promotes the osteogenic differentiation of tendon‐derived stem cells (TDSCs) in heterotopic ossification (HO). mTORC1 signaling favors differentiation of TDSCs into osteoblasts and promotes expression of Runx2 and OSX in HO of Achilles tendon.
Background
Current clinical treatment after tendon repairs often includes prescribing NSAIDs to limit pain and inflammation. The negative influence of NSAIDs on bone repair is well documented, but ...their effects on tendon healing are less clear. While NSAIDs may be detrimental to early tendon healing, some evidence suggests that they may improve healing if administered later in the repair process.
Questions/purposes
We asked whether the biomechanical and histologic effects of systemic ibuprofen administration on tendon healing are influenced by either immediate or delayed drug administration.
Methods
After bilateral supraspinatus detachment and repair surgeries, rats were divided into groups and given ibuprofen orally for either Days 0 to 7 (early) or Days 8 to 14 (delayed) after surgery; a control group did not receive ibuprofen. Healing was evaluated at 1, 2, and 4 weeks postsurgery through biomechanical testing and histologic assessment.
Results
Biomechanical evaluation resulted in decreased stiffness and modulus at 4 weeks postsurgery for early ibuprofen delivery (mean ± SD 95% CI: 10.8 ± 6.4 N/mm 6.7–14.8 and 8.9 ± 5.9 MPa 5.4–12.3) when compared to control repair (20.4 ± 8.6 N/mm 16.3–24.5 and 15.7 ± 7.5 MPa 12.3–19.2) (p = 0.003 and 0.013); however, there were no differences between the delayed ibuprofen group (18.1 ± 7.4 N/mm 14.2–22.1 and 11.5 ± 5.6 MPa 8.2–14.9) and the control group. Histology confirmed mechanical results with reduced fiber reorganization over time in the early ibuprofen group.
Conclusions
Early administration of ibuprofen in the postoperative period was detrimental to tendon healing, while delayed administration did not affect tendon healing.
Clinical Relevance
Historically, clinicians have often prescribed ibuprofen after tendon repair, but this study suggests that the timing of ibuprofen administration is critical to adequate tendon healing. This research necessitates future clinical studies investigating the use of ibuprofen for pain control after rotator cuff repair and other tendon injuries.
Introduction and hypothesisThe use of synthetic mesh for prolapse and incontinence surgery is discussed controversially and in several countries is either no longer used or permissible. Previous ...approaches with autologous tissue did not show from a patient´s perspective convincing long-term results. As there have been repeatedly significant complications with synthetic mesh, a new approach is urgently needed.During orthopedics and trauma surgeries, tendons from the thigh have been used for decades to replace cruciate ligament. The procedure of tendon removal from the thigh is fast, easy to learn and morbidity is low. In addition, a long-term durability of the transplant ought to be expected. The objective of this investigation was to show our experience with a semitendinosus tendon instead of a mesh for genital prolapse repair.MethodAfter the first successful attempts using such tendons in cervicosacropexy and pectopexy in patients with genital prolapse, we initiated a national multicenter study in 2020. Five German hospitals participated in order to determine the feasibility of cervicosacropexy with tendon tissue instead of mesh.ResultUp until now, we have operated and observed 113 patients for at least 6 months and have seen stable results in terms of fixation of the apical compartment. The expected low morbidity at the donor site was also confirmed through subjective assessment of the patients (Knee and Osteoarthritis Outcome Score). Improvement of quality of life was confirmed after the procedure with the Short Form Health Survey 12, Version 2.0. The results of this multicenter study showed that the desired elevation of the apical compartment with tendon tissue can be achieved with low morbidity and without a synthetic mesh.ConclusionWomen with uterine prolapse can be treated minimally invasively and with very low morbidity by using the semitendinosus tendon. The involvement of multiple (five) medical centers confirms that the technique is easy to learn and be transferred to other clinical centers.
Category:
Ankle, Basic Sciences/Biologics, Trauma
Introduction/Purpose:
The extensile lateral approach (EL) has been associated with increased wound complications such as apical necrosis which may be ...due partially from violation of the lateral calcaneal artery (LCA). Traditionally, the vertical limb has been placed half-way between the fibula and Achilles tendon, which may be suboptimal given the proximity to the LCA. We hypothesized that placing the vertical limb further posterior (ie, modified EL MEL) would increase the distance from the LCA. The purposes of this study were to quantify the location of the LCA in relation to the vertical limb of the traditional EL approach and to determine if utilizing the MEL approach endangered the LCA to a lesser extent.
Methods:
20 cadavers were used. For the EL approach, the fibula and Achilles tendon were palpated and a line parallel to the plantar foot was drawn between the two. A vertical line (VL), representing the vertical limb of the approach, was drawn at the midway point as a perpendicular extending proximally from the junction of the glabrous/non-glabrous skin (JGNG). For the MEL approach, the anterior border of the Achilles tendon was palpated and a similar vertical line (MVL) was drawn 0.75 cm anterior. Dissection was performed and if the LCA was identified crossing the line VL/MVL, the distance from the JGNG was documented.
Results:
For the EL approach, the LCA was identified in 17/20 (85%) cadavers at an average distance of 5.0 cm (range 3-7 cm, SD = 1.3 cm) from JGNG. For the ML approach, the LCA was identified in 4/20 (20%) cadavers at an average distance of 5.9 cm (range 3-6.5 cm, SD = 1.7 cm) from the JGNG (P < .001).
Conclusion:
The LCA was encountered 4 times more often during the EL approach as compared to the MEL approach.
Rates of Acute and Delayed Achilles Repair Younger, Alastair; Park, Sam Si-Hyeong; Veljkovic, Andrea ...
Foot & ankle orthopaedics,
09/2017, Letnik:
2, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Category: Sports, Trauma Introduction/Purpose: The need for repair of the ruptured achilles tendon has been discussed extensively in recent literature. A landmark paper in 2010 (Willits JBJS) ...outlined that the re-rupture rates were similar in surgical and non surgically treated Achilles tendon ruptures. However concern has to be raised as to the strength of the muscle tendon complex if the tendon is too long, potentially increasing the rate of late repair. This paper analyses the rate of acute achilles tendon repair and delayed repair before and after the 2010 publication of the Willits paper. Methods: Using the published billings from the Province of British Columbia, the rates per year of surgical repair of achilles tendon and delayed repair were determined. The population of British Columbia has increased over the years from 3.9 million in 1997 to 4.7 million in 2016. The rates of acute and chronic surgery were plotted prior to 2010, and since 2010. The rates were fitted against time using a linear and binomial plot. The rates in the years before and after 2010 were compared with ANOVA and the change of rate in time compared with Pearson’s correlation. Results: The rate of acute repair increased from 271 repairs in 1997 to over 400 repairs per year in 2009. The rate of acute repair has since dropped to just over 300 repairs per year. This is reflected in the enclosed binomial plot. There was a significant increase until 2010 (p<0.001), and a significant decrease since 2010 p<0.05). An average of 374 repairs per year (95% CI 349 to 398) were performed before 2010, decreasing to 328 since (95% CI 294 to 360), p<0.05. The rate of late repair has increased from 48 per year (CI 40 to 56) to 80 (CI 70 to 91) since 2010. The rate of late repair increased both prior to (r2 prior to 2010 .5, p<0.01) and since 2010. Conclusion: The landmark 2010 paper has resulted in a reduction of acute repair. However the increase in late repair is concerning and indicates that the muscle tendon weakness observed in the 2010 paper on strength testing at 1 year review in the non surgical group may be causing an increased rate of late repair. Further evaluation and development of both surgical and non surgical technique is required if the need for late repair is going to be avoided that likely reflects poor patient outcomes.
Category:
Basic Sciences/Biologics, Sports
Introduction/Purpose:
The drive to reduce soft tissue complications after Achilles tendon repair has led to increased interest in less invasive techniques. ...The PARS Achilles Jig System is one option that has gained popularity as an alternative to open repair. For many surgeons, standard open repair consists of a Krackow locking-loop technique. We compared the load to failure of a limited open and open Krackow technique for repair of Achilles tendon ruptures.
Methods:
Nine pairs of human cadaver lower limbs were randomized to undergo either a Krackow locking loop repair with epitendinous weave or a PARS Achilles Jig System Repair. Specimen were loaded to failure on a servo-hydraulic material testing machine. From load- displacement curves, initial linear stiffness, load to failure, and work to failure were calculated.
Results:
The average load to failure for Krackow repair (353.8 ± 88.8 N) and PARS repair (313.3 ± 99.9 N) was not statistically different (p = .38). The average work to failure for open repair (6.4 ± 2.3 J) and PARS repair (6.3 ± 3.5 J) was also not statistically different (p = .904). Mean initial linear stiffness of the Krackow repair (17.8 ± 5.4 N/mm) was significantly greater than the PARS repair (11.8 ± 2.5 N/mm) (p = .011). The predominant location of failure for Krackow repair was at the suture itself. In contrast, the PARS repair predominantly failed at the suture-tendon interface.
Conclusion:
The results suggest no difference between the Krackow and PARS repairs in terms of ultimate strength or work to failure. The Krackow repair demonstrated a higher initial linear stiffness than the PARS, which may imply a greater ability to withstand gap formation. With less devitalization to surrounding soft tissue and equal repair strength, the PARS system should be considered a favourable option for repair of ruptured Achilles tendons.
Purpose
The pes anserinus (PA) is characterized by high morphological diversity. As the semitendinosus and gracilis muscle tendons are routinely harvested for the reconstruction of other tendons, ...especially the anterior cruciate ligament (ACL), it is of clinical importance. The presence of accessory bands within PA tendons can handicap the harvesting process. Therefore, the purpose of the study was to suggest a new morphological classification of the PA morphology.
Methods
Classical anatomical dissection was performed on 102 lower limbs (56 right, 46 left) fixed in 10% formalin solution. The morphology and insertion of the PA (including accessory bands) were assessed, and morphometric measurements were taken.
Results
In all cases, the PA was present and composed of the sartorius, gracilis and semitendinosus tendons. Six types of PA were distinguished based on the presence of accessory bands. The most common composed of monotendinous sartorius, gracilis and semitendinosus—54 limbs (52.9%). Additionally, three types of insertion were noted (short, band-shaped and fan-shaped). The mean length between the insertion and the origin of the accessory bands to the fascia of the gastrocnemius muscle was 63.5 mm.
Conclusion
The morphology of the PA was highly variable. The gracilis and semitendinosus tendons often had accessory bands that would complicate the harvesting process. The planning of surgical procedures may be improved by our proposed classification.
Category: Hindfoot Introduction/Purpose: Assessment of hindfoot alignment in adult acquired flatfoot deformity (AAFD) can be challenging. Clinical judgment and radiograph studies while important may ...not represent the accurate valgus alignment of the affected patients. Weightbearing (WB) ConeBeam CT (CBCT) is an emerging imaging modality that may potentially better demonstrate the three-dimensional (3D) deformity, facilitating visualization of important soft-tissue and bony landmarks and helping in surgical planning. Based on the relative position of bone and soft-tissue axes, different measurements of hindfoot alignment can be obtained with CT images. Therefore, we compared clinical assessment of hindfoot valgus alignment in AAFD patients with different possible measurements performed on WB CBCT images. Methods: In this prospective, IRB-approved study, 20 patients (20 feet, 15 right and 5 left) with clinical diagnosis of flexible AAFD were included. There were 12 males and 8 females, with a mean age of 52.2 years (range, 20 – 88 years of age), and average BMI of 30.35 kg/m2 (range, 19.00 – 46.09 kg/m2). Patients underwent clinical assessment of hindfoot alignment as well as WB CBCT. Two independent and blinded foot and ankle board-certified surgeons performed different hindfoot alignment measurements on the WB CBCT images that included: 3D “clinical” alignment; Achilles tendon axis/calcaneal tuberosity angle; angles formed between the tibial axis and the calcaneal tuberosity, calcaneal axis and line connecting midpoint of subtalar joint and most inferior part of calcaneal tuberosity. Positive values were considered valgus alignment. Mean differences between the measurements modalities were compared by paired T-test. Intra- and Inter-observer reliability for the WB CBCT measurements were calculated using Pearson correlation. Results: The mean clinical hindfoot valgus measured was 15.15o (SD 7.7o). It was found to be significantly different from the mean values of all WB CBCT angles modalities: 3D “clinical” alignment (10.42o, p < 0.015); Achilles tendon/calcaneal tuberosity angle (2.96o, p < 0.0001); tibial axis/calcaneal tuberosity angle (5.42o, p < 0.0001); tibial axis/subtalar joint angle (7.52o, p < 0.0001) and tibial axis/calcaneal axis angle (20.39o, p < 0.017). We found an excellent intra-observer agreement for all WB CBCT 3D measurements (range, 0.8863 – 0.9713, p < 0.0001). There was also good to excellent inter-observer reliability, with the exception of the 3D “clinical” alignment (r=0.450, p < 0.04), that showed moderate correlation. Conclusion: The use of 3D WB CBCT imaging can help characterize the valgus hindfoot alignment in patients with adult acquired flatfoot deformity. We found the different CBCT measurements modalities to be reliable and repeatable, and to significantly differ from the clinical evaluation of hindfoot valgus alignment.
It is reported that decellularized collagen matrices derived from dermal skin and bone have been clinically used for tendon repair. However, the varying biological and physical properties of matrices ...originating from different tissues may influence the differentiation of tendon stem cells, which has not been systematically evaluated. In this study, the effects of collagenous matrices derived from different tissues (tendon, bone and dermis) on the cell differentiation of human tendon stem/progenitor cells (hTSPCs) were investigated, in the context of tendon repair. It was found that all three matrices supported the adhesion and proliferation of hTSPCs despite differences in topography. Interestingly, tendon-derived decellularized matrix promoted the tendinous phenotype in hTSPCs and inhibited their osteogenesis, even under osteogenic induction conditions, through modulation of the teno- and osteolineage-specific transcription factors Scleraxis and Runx2. Bone-derived decellularized matrix robustly induced osteogenic differentiation of hTSPCs, whereas dermal skin-derived collagen matrix had no apparent effect on hTSPC differentiation. Based on the specific biological function of the tendon-derived decellularized matrix, a tissue-engineered tendon comprising TSPCs and tendon-derived matrix was successfully fabricated for Achilles tendon reconstruction. Implantation of this cell–scaffold construct led to a more mature structure (histology score: 4.08±0.61 vs. 8.51±1.66), larger collagen fibrils (52.2±1.6nm vs. 47.5±2.8nm) and stronger mechanical properties (stiffness: 21.68±7.1Nmm−1 vs.13.2±5.9Nmm−1) of repaired tendons compared to the control group. The results suggest that stem cells promote the rate of repair of Achilles tendon in the presence of a tendinous matrix. This study thus highlights the potential of decellularized matrix for future tissue engineering applications, as well as developing a practical strategy for functional tendon regeneration by utilizing TSPCs combined with tendon-derived decellularized matrix.
PDF
