Tendon Repair Research Articles

Effect of Platelet-Rich Plasma at Different Initiation Times on Healing of the Bone-Tendon Interface of the Rotator Cuff in a Mouse Model.

Platelet-rich plasma (PRP) has demonstrated beneficial effects on healing of the bone-tendon interface (BTI). To determine the optimal initiation time for PRP application after rotator cuff repair in an animal model. Controlled laboratory study. A total of 136 C57BL/6 mice were included; 40 mice were used to prepare PRP, while 96 mice underwent acute supraspinatus tendon (SST) repair. The animals were randomly divided into 4 groups: a control group and 3 groups in which PRP was injected into the injury interface immediately after surgery, on the 7th postoperative day (PRP-7d), and on the 14th postoperative day. At 4 and 8 weeks postoperatively, the animals were sacrificed, blood was collected by eyeball removal, and samples of the SST-humerus complex were collected. Histological, imaging, immunological, and biomechanical data were compared among the groups using 1-way analysis of variance with the Bonferroni post hoc test. Histological analysis revealed that the fibrocartilage layer at the BTI was larger in the PRP-7d group compared to the other groups at both 4 and 8 weeks postoperatively. Moreover, the PRP-7d group exhibited improved proteoglycan content and distribution compared to the other groups. Enzyme-linked immunosorbent assay results demonstrated that at 4 weeks postoperatively, higher concentrations of transforming growth factor-β1 and platelet-derived growth factor-BB (PDGF-BB) were seen in the PRP-7d group versus the PRP-14d and control gruops (P < .05), and at 8 weeks postoperatively, the concentration of PDGF-BB was higher in the PRP-7d group versus the control group (P < .05). Biomechanical testing at 4 weeks postoperatively revealed that the failure load and ultimate strength of the SST-humerus complex were superior in the PRP-7d group compared to the other groups (P < .05), at 8 weeks, PRP-7d group was superior to the control group (P < .05). Additionally, at 8 weeks postoperatively, the PRP-7d group exhibited a greater trabecular number and trabecular thickness at the BTI compared to the PRP-14d and control gruops (P < .05). PRP promoted healing of the BTI after a rotator cuff injury at an early stage. A PRP injection on the 7th postoperative day demonstrated superior therapeutic effects compared with injections at other time points.

Reconstruction of Chronic Quadriceps Tendon Rupture: The Quadriceps Advancement and Imbrication Technique

BackgroundChronic extensor mechanism disruption after total knee arthroplasty (TKA) is a rare but challenging condition. There are several surgical approaches for quadriceps tendon repairs. In this report, we present a modified surgical technique for quadriceps tendon repair in chronic extensor mechanism disruption without the use of allografts or mesh augmentation. MethodsWe retrospectively reviewed 12 consecutive cases of chronic extensor mechanism with complete quadriceps tendon ruptures after TKA that underwent the advancement and imbrication technique. Patient outcomes were evaluated using the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the range of motion and extensor lag measurements, and standardized lateral radiographs were reviewed for Insall-Salvati-Ratio preoperatively and at their most recent follow-up visit. ResultsThere were 12 knees from patients who had a mean age of 72 years (range, 62 to 81) and were evaluated with a mean follow-up of 15.9 months (range, 11.4 to 50.9). The extensor lag significantly improved from 40.8 ± 31.9° (range, 10 to 90°) to 2.9 ± 6.9° (P = .014), the Insall-Salvati-Ratio significantly changed from 0.87 to 1.07 (P = .010), and the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement showed a significant difference: a raw score of 13.0 ± 5.8 versus 8.7 ± 5.6 (P = .002) and an interval score of 54.1 ± 14.0 versus 66.2 ± 15.6 (P = .001). ConclusionsReconstruction of extensor mechanism in chronic quadriceps tendon ruptures after TKA with the advancement and imbrication technique showed excellent functional outcomes with no extensor lag and excellent restoration of motion. This technique can be combined with TKA revision surgery or used on its own. To ensure successful outcomes, the authors favor rigid immobilization for 12 weeks before starting mobilization.

Clinical Outcomes and Tendon Healing After Arthroscopic Isolated Subscapularis Tendon Repair: Results at Midterm Follow-up.

Few studies have reported clinical outcomes and tendon healing rates after arthroscopic isolated subscapularis (SSC) repair (AISR). The primary purpose of this study was to evaluate clinical outcomes and tendon healing after AISR. It was hypothesized that AISR would result in satisfactory clinical outcomes along with a high rate of tendon healing at the midterm follow-up. The secondary purpose was to assess the influence of tear size and muscle atrophy on SSC tendon healing and patient-reported outcomes. It was hypothesized that both would be negatively correlated with healing but would have no effect on clinical outcomes . Case series; Level of evidence, 4. A retrospective analysis was conducted on prospectively collected data for 77 patients who underwent primary AISR between 2011 and 2021 at a single institution, with a minimum 2-year postoperative follow-up for all patients. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, the Subjective Shoulder Value (SSV), and the visual analog scale for pain. Repair techniques and concomitant procedures were also collected. SSC tendon healing was evaluated via ultrasound at the final follow-up. Linear regression analysis was performed to determine factors affecting SSC healing. The mean follow-up was 58.1 ± 3.3 months. ASES scores significantly improved from 41.5 to 81.6, and the SSV improved from 38.2 to 80.5 (P < .01 for both). Among the 40 patients (51.9%) who underwent postoperative ultrasound, 87.5% showed complete tendon healing. There were no significant differences in outcome scores between healed and unhealed tendons. Increased muscle atrophy and larger tears were correlated with failure of SSC healing (β = -0.285 [P = .015] and β = -0.157 [P = .045], respectively). Improved clinical outcomes and an overall high rate of tendon healing were seen at the midterm follow-up after AISR. Smaller tear sizes with less muscle atrophy were correlated with improved tendon healing. However, even when the tendon incompletely healed, the procedure improved functional outcomes.

Risk Factors Associated With Poor Outcomes After Quadriceps Tendon Repair.

Ruptures of the quadriceps tendon present most frequently in older adults and individuals with underlying medical conditions. To examine the relationship between patient-specific factors and tear characteristics with outcomes after quadriceps tendon repair. Case-control study; Level of evidence, 3. A retrospective review was conducted on all patients who underwent quadriceps tendon repair between January 1, 2016, and January 1, 2021, at a single institution. Patients <18 years and those with chronic quadriceps tendon tears (>6 weeks to surgery) were excluded. Information was collected regarding patient characteristics, presenting symptoms, tear characteristics, physical examination findings, and postoperative outcomes. Poor outcome was defined as a need for revision surgery, complications, postoperative range of motion of (ROM) <110° of knee flexion, and extensor lag of >5°. A total of 191 patients met the inclusion criteria. Patients were aged 58.5 ± 13.2 years at the time of surgery, were predominantly men (90.6%), and had a mean body mass index (BMI) of 32.2 ± 6.3 kg/m2. Patients underwent repair with either suture anchors (15.2%) or transosseous tunnels (84.8%). Postoperatively, 18.5% of patients experienced knee flexion ROM of <110°, 11.3% experienced extensor lag of >5°, 8.5% had complications, and 3.2% underwent revision. Increasing age (odds ratio [OR], 1.03 [95% CI, 1.004-1.07]) and female sex (OR, 3.82 [95% CI, 1.25-11.28]) were significantly associated with postoperative knee flexion of <110°, and increasing age (OR, 1.08 [95% CI, 1.04-1.14]) and greater BMI (OR, 1.14 [95% CI, 1.05-1.23]) were significantly associated with postoperative extensor lag of >5°. Current smoking status (OR, 15.44 [95% CI, 3.97-65.90]) and concomitant retinacular tears (OR, 9.62 (95% CI, 1.67-184.14]) were associated with postoperative complications, and increasing age (OR, 1.05 [95% CI, 1.02-1.08]) and greater BMI (OR, 1.08 [95% CI, 1.02-1.14]) were associated with risk of acquiring any poor outcome criteria. Patient-specific characteristics-such as increasing age, greater BMI, female sex, retinacular involvement, and current smoking status-were found to be risk factors for poor outcomes after quadriceps tendon repair. Further studies are needed to identify potentially modifiable risk factors that can be used to set patient expectations and improve outcomes.

Open Bankart Repair with Subscapularis Split.

Anterior shoulder dislocations are a common injury, especially in the young, active, male population1. Soft-tissue treatment options for shoulder instability include arthroscopic or open Bankart repair, with open Bankart repair historically having lower rates of recurrence and reoperation, faster return to activity2-4, and a similar quality of life compared with arthroscopic repair5. More recent literature has suggested similar recurrence rates between arthroscopic and open procedures6. However, open Bankart repair may be indicated in cases of recurrent instability, especially if the patient participates in high-risk sports, because open repair can provide more capsular shift through the use of extra-capsular knots7. Performing a subscapularis split decreases the likelihood of subscapularis tendon avulsion following subscapularis tendon tenotomy and subsequent repair, as has been described in the literature8. Indications for open Bankart repair include failure of arthroscopic Bankart repair, multiple dislocations, with subcritical bone loss. This surgical technique is performed via the deltopectoral approach. The subscapularis tendon is exposed and "spared" by splitting the fibers with use of a longitudinal incision between the upper 2/3 and lower 1/3 of the subscapularis. We begin the split medially near the myotendinous junction. Because the subscapularis becomes increasingly difficult to separate from the capsule as it tracks laterally, a RAY-TEC sponge is utilized to bluntly dissect. A T-shaped laterally based capsulotomy is made to expose the glenohumeral joint. The vertical aspect is made first, followed by the horizontal aspect from lateral to medial, extending to the labrum. A Fukuda retractor is placed through the split to hold the humeral head laterally. The labrum is elevated, and the glenoid is prepared with rasp. Then labrum is repaired with knotted suture anchors until it is secure. One anchor is utilized for each "hour" of the clock face, with a minimum of 3 anchors. The anchors are placed on the articular margin of the glenoid. Sutures are passed from the anchor through the capsule and tied outside the capsule. The capsulotomy is then repaired with use of a suture. The suture is utilized to pull the inferior portion superiorly. The inferior portion is taken superiorly, and the superior leaflet is imbricated over the top. Finally, an examination is performed to ensure that the humeral head can be translated to but not over the anterior and posterior glenoid rims. No repair of the subscapularis tendon insertion is required. The incision is closed with deep dermal and subcuticular suture. Nonoperative treatment options include rotator cuff and periscapular strengthening or immobilization. Operative treatment options include open Bankart repair with subscapularis tenotomy and repair, arthroscopic Bankart repair, or bone block augmentation procedures. This procedure is different from the alternative treatments in that it is an open procedure, which allows for a more robust repair because the capsule can be shifted and doubled over, leading to the described decreased recurrence and reoperation rates. Open Bankart repair is better suited for large lesions that would be difficult to repair via arthroscopy. This procedure differs from other open Bankart techniques because the subscapularis is split rather than tenotomized, which removes the need to repair the tendon and decreases the rate of avulsion of the subscapularis tendon repair. Finally, this procedure is less invasive than the Latarjet procedure because it does not require osseous osteotomies and fixation. This procedure provides adequate capsular shift and visualization of the Bankart lesion without the increased risk of postoperative subscapularis tendon injury. If the subscapularis split alone does not provide adequate visualization, portions of the subscapularis tendon can be released from the lesser tuberosity.The location and origin of the upper and lower subscapular nerves can have variable courses, which could theoretically put them at risk for iatrogenic injury; however, studies have shown this subscapularis split technique to be safe from and prevent denervation of the muscle. GBL = glenoid bone lossEUA = examination under anesthesiaMRI = magnetic resonance imagingHSL = Hill-Sachs lesionAHCA = anterior humeral circumflex artery.

Outcomes of Isolated Endoscopic Gluteal Tendon Repair Compared With Concomitant Endoscopic Gluteal Tendon Repair and Arthroscopic Hip Labral Repair: A Propensity-Matched Analysis With Minimum 2-Year Follow-up.

Both gluteal and labral tears are common sources of hip pain, but no studies have evaluated how concomitant arthroscopic labral repair and correction of femoroacetabular impingement syndrome (FAIS) affect outcomes after endoscopic gluteus/minimus repair. (1) To compare patient-reported outcomes (PROs) and clinically significant outcomes achievements between patients who underwent endoscopic gluteus medius/minimus and arthroscopic hip labral repair with correction of FAIS versus endoscopic gluteus medius/minimus repair without labral repair and (2) to define threshold scores required to achieve the minimal clinically important difference (MCID) and the Patient Acceptable Symptom State (PASS) for the Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports Specific, modified Harris Hip Score (mHHS), 12-item international Hip Outcome Tool, and visual analog scale for pain in these patients. Cohort study; Level of evidence, 3. Patients who underwent primary endoscopic gluteus medius/minimus repair between 2012 and 2020 were identified. Those who underwent concomitant arthroscopic labral repair and correction of FAIS with femoroplasty or acetabuloplasty as indicated were propensity matched in a 1 to 1 ratio by sex, age, and body mass index to patients who underwent gluteus medius/minimus repair without labral repair. Patients who completed the study PROs were assessed preoperatively and at 2 years postoperatively. Threshold scores required to achieve the MCID and PASS thresholds were calculated. A total of 32 patients who underwent simultaneous gluteal and labral repair (G+L) were matched to 32 patients who underwent gluteal repair without labral repair (G); 75% of patients in the G cohort underwent labral debridement, while 25% in this cohort received no labral treatment. A significant difference was observed between groups in preoperative mHHS scores (G+L, 54.4 ± 12.9 vs G, 46.3 ± 14; P = .048) but no differences in any other PRO scores (P≥ .207). The MCID/PASS thresholds were as follows: Hip Outcome Score-Activities of Daily Living (11.14/83.82), Hip Outcome Score-Sports Specific (16.07/59.72), mHHS (11.47/70.95), 12-item international Hip Outcome Tool (13.73/45.49), and visual analog scale for pain (14.30/22). There were no significant differences in MCID or PASS achievement rates between the 2 groups (P≥ .108). Patients who underwent combined G+L demonstrated comparable PROs and clinically significant outcomes achievement rates to patients who underwent G, highlighting sustained successful outcomes for patients with gluteal tendon pathology and concomitant FAIS and labral tears.

Factors in Hand Surgery Access for Rheumatoid Arthritis Before vs After the Patient Protection and Affordable Care Act

Rheumatoid arthritis (RA) has severe functional and economic consequences. The implications of the Patient Protection and Affordable Care Act (ACA) and demographic factors for access to surgical treatment are unclear. To investigate factors associated with time to RA hand surgery, surgical incidence, and cost after implementation of the ACA. This cross-sectional study used insurance data from the IBM MarketScan Research Databases from 2009 through 2020 to compare time to surgery, surgical incidence, and treatment cost for RA of the hand before and after ACA implementations. Included patients were 18 years or older with a new diagnosis for RA of the hand and at least 1 procedural code for arthroplasty, arthrodesis, tenolysis, tendon repair, or tendon transfer. Patients with coexisting inflammatory arthritis diagnoses were excluded. Demographic variables analyzed included patient sex, age at index date, residence within or outside a metropolitan statistical area (MSA; hereafter urban or nonurban), insurance and health plan type, Social Deprivation Index, Elixhauser Comorbidity Index score, and Rheumatic Disease Comorbidity Index. Data analysis occurred from October 2022 to April 2023. Surgery for RA of the hand during the pre-ACA (before 2014) vs post-ACA (2014 or later) periods. Time to surgery, surgical incidence, and cost of treating RA in patients undergoing hand surgery for RA. Among 3643 patients (mean [SD] age, 57.6 [12.3] years) who underwent hand surgery for RA, 3046 (83.6%) were women. Post-ACA passage, 595 (86.2%) patients who resided in urban areas had a significantly lower time to surgery than those who did not (-70.5 [95% CI, -112.6 to -28.3] days; P < .001). Among urban patients, the least socially disadvantaged patients experienced the greatest decrease in time to surgery after ACA but the change was not statistically significant. For all patients, greater social disadvantage (ie, a higher SDI score) was associated with a longer time to surgery in the post-ACA period; for example, compared with the least socially disadvantaged group (SDI decile, 0-10), patients in SDI decile 10 to 20 waited an additional 254.0 days (95% CI, 65.2 to 442.9 days; P = .009) before undergoing surgery. Compared with the pre-ACA period, the mean surgical incidence in the post-ACA period was 83.4% lower (162.3 vs 26.9 surgeries per 1000 person-years; P < .001), and surgical incidence was 86.3% lower in nonurban populations (27.2 vs 3.7 surgeries per 1000 person-years; P < .001) but only 82.8% lower in urban populations (135.1 vs 23.2 surgeries per 1000 person-years; P < .001). Per capita total costs of all treatment related to RA of the hand decreased in the post-ACA period but the change was not statistically significant. Insurer-paid costs were lower in the post-ACA period but the change was not statistically significant. Out-of-pocket expenses did not change. Findings of this cross-sectional study suggest that after ACA passage, disparities exist in access to timely, cost-effective hand surgery for RA. Increased access to surgical hand specialists is needed for nonurban residents and those with greater social deprivation, along with insurance policy reforms to further decrease out-of-pocket spending for RA hand surgery.

A Hybrid Electrospun-Extruded Polydioxanone Suture for Tendon Tissue Regeneration.

Many surgical tendon repairs fail despite advances in surgical materials and techniques. Tendon repair failure can be partially attributed to the tendon's poor intrinsic healing capacity and the repurposing of sutures from other clinical applications. Electrospun materials show promise as a biological scaffold to support endogenous tendon repair, but their relatively low tensile strength has limited their clinical translation. It is hypothesized that combining electrospun fibers with a material with increased tensile strength may improve the suture's mechanical properties while retaining biophysical cues necessary to encourage cell-mediated repair. This article describes the production of a hybrid electrospun-extruded suture with a sheath of submicron electrospun fibers and a core of melt-extruded fibers. The porosity and tensile strength of this hybrid suture is compared with an electrospun-only braided suture and clinically used sutures Vicryl and polydioxanone (PDS). Bioactivity is assessed by measuring the adsorbed serum proteins on electrospun and melt-extruded filaments using mass spectrometry. Human hamstring tendon fibroblast attachment and proliferation were quantified and compared between the hybrid and control sutures. Combining an electrospun sheath with melt-extruded cores created a hybrid braid with increased tensile strength (70.1 ± 0.3N) compared with an electrospun only suture (12.9 ± 1 N, p < 0.0001). The hybrid suture had a similar force at break to clinical sutures, but lower stiffness and stress. The Young's modulus was 772.6 ± 32 MPa for the hybrid suture, 1693.0 ± 69 MPa for PDS, and 3838.0 ± 132 MPa for Vicryl, p < 0.0001. Hybrid sutures had lower overall porosity than electrospun-only sutures (40 ± 4% and 60 ± 7%, respectively, p = 0.0018) but had a significantly larger overall porosity and average pore diameter compared with surgical sutures. There were similar clusters of adsorbed proteins on electrospun and melt-extruded filaments, which were distinct from PDS. Tendon fibroblast attachment and cell proliferation on hybrid and electrospun sutures were significantly higher than on clinical sutures. This study demonstrated that a bioactive suture with increased tensile strength and lower stiffness could be produced by adding a core of 10 μm melt-extruded fibers to a sheath of electrospun fibers. In contrast to currently used sutures, the hybrid sutures promoted a bioactive response: serum proteins adsorbed, and fibroblasts attached, survived, grew along the sutures, and adopted appropriate morphologies.

Tuning the properties of all natural polymeric scaffolds for tendon repair with cellulose microfibers

Rotator cuff injuries affect a large percentage of the population worldwide. Surgical repair has rates of failure of up to 70%, and existing materials used in the reinforcement of injuries often lack appropriate mechanical properties and biodegradability. There is a clinical need for tendon biomaterials that enable cell attachment and proliferation, while supporting mechanically the injury site. In this work, we develop a novel all-natural polymeric scaffold for applications in the supraspinatus tendon of the shoulder. The unidirectional freezing technique is applied to a chitosan-gelatine matrix containing varying cellulose concentrations, followed by crosslinking with genipin. The viability of the technique using a custom 3D printed mould is evaluated. The scaffolds' morphology and mechanical properties are extensively characterized: the ultimate tensile strength of the material with 20% cellulose was found to increase 6-fold compared to scaffolds without cellulose; significant effects on the microstructure of the scaffold were evidenced via scanning electron microscopy. Furthermore, the biocompatibility of the materials was characterized with both porcine tendon derived cells and normal human dermal fibroblasts. All scaffolds are highly biocompatible, the incorporation of cellulose results in higher cell metabolic activity values and density of cells on the surface of the material. Scaffolds containing 20% cellulose fibers were found to possess the optimal biomechanical properties for applications in rotator cuff tendon repair.

In Vitro Assessment of Bacterial Adhesion and Biofilm Formation on Novel Bioactive, Biodegradable Electrospun Fiber Meshes Intended to Support Tendon Rupture Repair.

The surgical repair of a ruptured tendon faces two major problems: specifically increased fibrous adhesion to the surrounding tissue and inferior mechanical properties of the scar tissue compared to the native tissue. Bacterial attachment to implant materials is an additional problem as it might lead to severe infections and impaired recovery. To counteract adhesion formation, two novel implant materials were fabricated by electrospinning, namely, a random fiber mesh containing hyaluronic acid (HA) and poly(ethylene oxide) (PEO) in a ratio of 1:1 (HA/PEO 1:1) and 1:4 (HA/PEO 1:4), respectively. Electrospun DegraPol (DP) treated with silver nanoparticles (DP-Ag) was developed to counteract the bacterial attachment. The three novel materials were compared to the previously described DP and DP with incorporated insulin-like growth factor-1 (DP-IGF-1), two implant materials that were also designed to improve tendon repair. To test whether the materials are prone to bacterial adhesion and biofilm formation, we assessed 10 strains of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Enterococcus faecalis, known for causing nosocomial infections. Fiber diameter, pore size, and water contact angle, reflecting different degrees of hydrophobicity, were used to characterize all materials. Generally, we observed higher biofilm formation on the more hydrophobic DP as compared to the more hydrophilic DP-IGF-1 and a trend toward reduced biofilm formation for DP treated with silver nanoparticles. For the two HA/PEO implants, a similar biofilm formation was observed. All tested materials were highly prone to bacterial adherence and biofilm formation, pointing toward the need of further material development, including the optimized incorporation of antibacterial agents such as silver nanoparticles or antibiotics.

Biomechanical evaluation of the ST-knot: A new suture for flexor tendon repair

PurposeAlthough tendon lacerations are common, there is currently no consensus on choice of suture. Easy and fast sutures that impart enough strength to allow mobilization are needed. This study compared the ex vivo biomechanical strength (force required to create a 2 mm tendon gap) of a novel suture (ST-knot) with that of a conventional suture (double Kessler). Materials and methodsForty fresh deep flexor tendons from porcine forelimbs were used. Both repaired tendon ends were mounted on standard traction jaws of an axial traction machine at an initial distance of 40 mm for all tendons. A high-definition camera was used to determine the force forming a 2 mm gap. Ten tendons in group 1 (ST-knot) and 10 in group 2 (double Kessler) were prepared with PDS 4.0 (single thread for Kessler, double thread for ST-knot). Tendons in groups 3 (ST-knot) and 4 (double Kessler) were repaired with PDS 1.0 using the same principle. ResultsThere was no significant difference in the force required to form a 2 mm tendon gap between groups 1 and 2, and this trend was identical when using a stronger thread in groups 3 and 4. The maximum force before rupture, mode of repair failure, stress and stiffness were also comparable, with no significant differences between groups 1 and 2, or between groups 3 and 4. ConclusionsThe ST-knot showed comparable results to the double-Kessler knot, whichever the thread used. Because it involves fewer steps than conventional techniques and is easy to perform, the ST-knot may offer a therapeutic solution, particularly in complex trauma with multiple tendon injury.

Case report: Nonsimultaneous bilateral triceps tendon rupture and surgical repair in a healthy dog

A 7-year-old female spayed Australian shepherd dog was presented for an acute onset of inability to stand. On physical examination, the dog was unable to support weight on the thoracic limbs. On neurological examination, the thoracic limbs had absent hopping and paw placement and reduced withdrawal reflexes bilaterally. The remainder of the neurological examination was normal. The anatomic lesion localized to the C6-T2 spinal nerve roots, spinal nerves, or the named nerves of the thoracic limb, bilaterally. A lesion affecting the ventral gray column of the C6 through T2 spinal cord segments was considered less likely. In an effort to exclude an orthopedic disorder from consideration, radiographs of the shoulders, elbows, and manus were normal. Magnetic resonance imaging of the cervical and cranial thoracic vertebral column was normal. Analysis of synovial fluid from the carpi, elbows, and shoulders were normal. Ultrasonography of the triceps muscle and tendon of insertion revealed bilateral, acute-subacute tears of the tendon at insertion of the triceps muscles, bilaterally. Magnetic resonance imaging of both elbows revealed complete avulsion of the triceps tendons bilaterally. Surgical repair of both tendons was performed using the Arthrex FiberLoop system combined with autologous conditioned plasma soaked in a collagen sponge. Postoperatively, external coaptation was provided using Spica splints for 6 weeks followed by the use of soft padded orthotic braces for an additional 6 weeks. Concurrently, a front support wheelchair was used for 10 weeks postoperative. By 10 weeks postoperative, the dog was able to ambulate without support. To the authors’ knowledge, this is the first report of bilateral triceps tendon avulsion in a dog. Tendon avulsion occurred without a known history of trauma or predisposing metabolic abnormalities. Magnetic resonance imaging provided excellent anatomical detail that aided in surgical repair.

Treatment of Equine Tarsus Long Medial Collateral Ligament Desmitis with Allogenic Synovial Membrane Mesenchymal Stem/Stromal Cells Enhanced by Umbilical Cord Mesenchymal Stem/Stromal Cell-Derived Conditioned Medium: Proof of Concept

Horses are high-performance athletes prone to sportive injuries such as tendonitis and desmitis. The formation of fibrous tissue in tendon repair remains a challenge to overcome. This impels regenerative medicine to develop innovative therapies that enhance regeneration, retrieving original tissue properties. Multipotent Mesenchymal Stem/Stromal Cells (MSCs) have been successfully used to develop therapeutic products, as they secrete a variety of bioactive molecules that play a pivotal role in tissue regeneration. These factors are released in culture media for producing a conditioned medium (CM). The aforementioned assumptions led to the formulation of equine synovial membrane MSCs (eSM-MSCs)—the cellular pool that naturally regenerates joint tissue—combined with a medium enriched in immunomodulatory factors (among other bioactive factors) produced by umbilical cord stroma-derived MSCs (eUC-MSCs) that naturally contribute to suppressing the immune rejection in the maternal–fetal barrier. A description of an equine sport horse diagnosed with acute tarsocrural desmitis and treated with this formulation is presented. Ultrasonographic ligament recovery occurred in a reduced time frame, reducing stoppage time and allowing for the horse’s return to unrestricted competition after the completion of a physical rehabilitation program. This study focused on the description of the therapeutic formulation and potential in an equine desmitis treatment using the cells themselves and their secretomes.

Dual-Targeted Metal Ion Network Hydrogel Scaffold for Promoting the Integrated Repair of Tendon-Bone Interfaces.

The tendon-bone interface has a complex gradient structure vital for stress transmission and pressure buffering during movement. However, injury to the gradient tissue, especially the tendon and cartilage components, often hinders the complete restoration of the original structure. Here, a metal ion network hydrogel scaffold, with the capability of targeting multitissue, was constructed through the photopolymerization of the LHERHLNNN peptide-modified zeolitic imidazolate framework-8 (LZIF-8) and the WYRGRL peptide-modified magnesium metal-organic framework (WMg-MOF) within the hydrogel scaffold, which could facilitate the directional migration of metal ions to form a dynamic gradient, thereby achieving integrated regeneration of gradient tissues. LZIF-8 selectively migrated to the tendon, releasing zinc ions to enhance collagen secretion and promoting tendon repair. Simultaneously, WMg-MOF migrated to cartilage, releasing magnesium ions to induce cell differentiation and facilitating cartilage regeneration. Infrared spectroscopy confirmed successful peptide modification of nano ZIF-8 and Mg-MOF. Fluorescence imaging validated that LZIF-8/WMg-MOF had a longer retention, indirectly confirming their successful targeting of the tendon-bone interface. In summary, this dual-targeted metal ion network hydrogel scaffold has the potential to facilitate synchronized multitissue regeneration at the compromised tendon-bone interface, offering favorable prospects for its application in the integrated reconstruction characterized by the gradient structure.

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.

Induction of macrophage polarization by electrospun nano-yarn containing naproxen sodium to promote tendon repair

Excessive inflammatory response can lead to failure of the tendon repair surgery. Tendon substitutes that can effectively balance inflammatory responses and have sufficient mechanical properties are one of the key factors in promoting repair. In this study, the nanofibers containing the naproxen sodium were attached to polylactic acid micron yarn by electrospinning to obtain double-layer core-spun yarn (DY). The DY was knitted into a tendon tissue engineering scaffold with sufficient mechanical properties. This study confirmed the optimal loading concentration of naproxen sodium. The results in vitro and in vivo indicated that sustained-release naproxen sodium in scaffolds could effectively inhibit the rapid proliferation of foreign fibroblasts, accelerate the polarization of macrophages, reduce the inflammatory response, and promote tendon tissue repair. This study provides a new scaffold for tendon tissue engineering that not only serves as a substitute for tendon repair, but also serves as an anti-inflammatory agent to better promote the repair process.

An Early Functional Unsupervised Rehabilitation Protocol Allows Safe Return to Function After Achilles Tendon Repair.

Acute Achilles tendon tears in young active individuals are often treated surgically with prolonged rehabilitation, with the leg initially immobilized in plantar flexion in serial non-weight bearing casts and gradually progressing to full weight bearing. This study aimed to evaluate the safety of an early functional unsupervised rehabilitation protocol. The medical records of 25 patients treated with open repair were available for follow-up. In 10 patients, an early functional unsupervised rehabilitation protocol was used with a removable cast, active range of motion exercises of the ankle from the first postoperative day, and full weight bearing in a walking boot with the foot plantigrade after the second week. Another 15 patients who followed the classic rehabilitation protocol were used as controls. The patients were evaluated with the Victorian Institute of Sports Assessment-Achilles (VISA-A) and an ultrasound examination-based score. A Wilcoxon test was used to compare the scores between the groups. The mean VISA-A score was 90.1 (SD = 9.87) for the early functional rehabilitation protocol group, while it was 83.8 (SD = 17.06, p = 0.624) for the control group. The mean ultrasound score was 7.75 (SD = 1.71)for the early functional rehabilitation protocol group, while it was 7.60 (SD = 3.05, p = 0.414) for the control group. There were no intra- or early postoperative complications in the groups, and all patients were satisfied with the results of their operation. An early unsupervised functional rehabilitation protocol after open Achilles repair may allow for safe early mobilization and minimize the need for physiotherapy. The small number of participants is a limitation of this study, and further evaluation with more patients is necessary to document the efficacy.

Incidence and Time Course of Symptomatic Thromboembolic Outcomes After Lower Extremity Arthroscopic Surgery, Ankle Fracture Surgery, and Achilles Tendon Repair.

The incidence and time course of acute venous thromboembolism (VTE) after ambulatory surgery for lower extremity orthopaedic conditions is not well-defined. The purpose of this study was to analyze the incidence, the time course, and risk factors associated with clinically diagnosed acute deep vein thrombosis or pulmonary embolism within 3 months of surgery in patients undergoing specific operations for lower extremity injuries. Patients undergoing arthroscopic procedures of the knee, ankle fracture surgery, Achilles tendon repair, and ankle arthroscopy from January 1, 2005, to December 31, 2010, were identified in the California Ambulatory Surgery database with linkage to hospital discharge data, emergency department data, and a death registry. Outcomes were acute VTE and death within 90 days. Time courses were compared using Kaplan-Meier analysis, and risk factors were analyzed using proportional hazard modeling. Analysis of data from 468,699 surgeries showed that the cumulative incidence of acute VTE was significantly higher after Achilles tendon repair (0.72%, P < 0.001) than ankle fracture surgery (0.33%), knee arthroscopy procedures (range, 0.29% to 0.41%), or ankle arthroscopy (0.24%). The time course of diagnosis of VTE was similar for all arthroscopic procedures (median postoperative day for diagnosis = 9 to 10; 80% by 22 to 36 days), whereas for Achilles tendon surgery, the time course was protracted (median postoperative day for diagnosis = 29 days; 80% by 51 days). Ninety-day mortality was low (<0.06%) after all procedures except ankle fracture (0.12%). Predictors of pulmonary embolism included age older than 60 years (HR, 3.1; 95% CI; 2.0 to 4.8, versus younger than 30 years), Achilles tendon repair (HR, 3.8; 95% CI; 2.8 to 5.3), and ankle fracture surgery (Hazard Ratio [HR], 2.1; 95% Confidence Interval [CI]; 1.5 to 2.8); Asian/Pacific Islander (HR, 0.3; 95% CI; 0.1 to 0.6) and Hispanic patients (HR, 0.5; 95% CI; 0.4 to 0.7) had significantly lower risk. The incidence and time course of onset of acute VTE after lower extremity orthopaedic surgeries varies significantly depending on the surgical procedure. These findings have implications regarding the use and duration of pharmacologic thromboprophylaxis.

Does subscapularis tears combined with supraspinatus tears affect postoperative functional outcomes?

Aims: Roughly 50% of rotator cuff tears includes a tear in the subscapularis tendon. We conducted a comparative analysis of the functional outcomes following arthroscopic repair in patients with a tear in both the supraspinatus and subscapularis tendons, as well as those with a rupture solely in the supraspinatus tendon. Our hypothesis posits that the functional outcomes after surgery for rotator cuff tears, specifically those with tears including subscapularis tendon, are inferior compared to tears that only involve the supraspinatus tendon. Methods: We classified patients who had arthroscopic repair for a rotator cuff tear in our clinic from January 2017 to April 2022 into two groups. The study comprised patients who received arthroscopic surgery for a diagnosed rotator cuff injury. The study excluded individuals who were younger than 18, individuals with large tears that could not be repaired, individuals with paralabral cysts, individuals with glenohumeral arthritis, individuals who had undergone labrum tear repair or slap lesion repair, individuals with concomitant neurovascular damage, and individuals who had a follow-up period of less than 6 months, patients who benefit from physiotherapy and medical treatment for 6 months. Following the application of exclusion criteria, a total of 39 patients were selected to participate in the study. The presence of a rotator cuff injury was verified through arthroscopy after being detected using clinical tests such as Jobe, drop arm test, Neer sign, lift-off and belly-press tests, and radiographic evidence such as magnetic resonance imaging. Patients who received subscapularis repair together with a supraspinatus tear were categorised as Group 1 (n=14), while those who just had supraspinatus surgery without any subscapularis tears were categorized as Group 2 (n=25). We recorded the demographic information. At the last postoperative outpatient clinic follow-up, both groups were compared in terms of mortality, laboratory parameters, radiological findings, visual analogue scale (VAS), Constant-Murley score1, American Shoulder and Elbow Surgeons score (ASES)2, and University of California Los Angeles (UCLA) scores.3 Postoperative satisfaction levels were categorised into four groups: very satisfied, satisfied, undecided, and dissatisfied. Results: The groups did not show any significant differences in terms of age, gender distribution, and follow-up periods (p&amp;gt;0.05). There was no statistically significant disparity observed between the groups in relation to VAS, Constant-Murley score, ASES, and UCLA ratings assessed during the final postoperative outpatient clinic follow-up (p&amp;gt;0.05). There were no instances of re-rupture observed in any patient throughout the postoperative follow-up period. The postoperative satisfaction ratings show no significant difference between the two groups (p&amp;gt;0.05). Conclusion: Our findings indicate that the outcomes of patients who received a surgical repair of rotator cuff tendons including subscapularis were at least as successful as those who underwent surgery for just supraspinatus tendon rupture. There is no basis to believe that arthroscopic repair will have a detrimental impact on the functional outcomes of individuals with rotator cuff tears which includes subscapularis tendon tears.

Optimal access for Achilles Tendon Repair

Background. Despite the many accesses described in the literature for open Achilles tendon repair, there is no evidence of the benefits of this or that access confirmed by clinical observations.The aim is to determine and justify optimal access during open Achilles tendon repair.Material and methods. The article shows the result of the analysis of data from a literary search, experimental work on 12 lower limbs of 6 cadavers, a clinical study based on a retro-prospective analysis of the treatment of 128 people in the Department of Emergency Traumatology N.V. Sklifosovsky Research Institute from 2014 to 2022. The comparison group retrospectively included 47 patients (36.7%) with Achilles tendon injury, who underwent suture of the Achilles tendon from S and Z–shaped accesses from 2014 to 2017. The main group prospectively included 81 patients (63.3%) for 2018-2022, who underwent paramedial tendon access.Results. The analysis of a retrospective study showed that 3 patients from the comparison group with Achilles tendon injury in the postoperative period had ischemia of the wound edges with subsequent formation of necrosis and skin defect; 1 patient had a hypertrophic painful scar, which ulcerated from the constant traumatization of his shoe back (the total number of complications was 8.5%). In the patients of the main group, there were no complications in the postoperative period in any case. Conclusion. In our opinion, the paramedial tendon access is optimal, because there are no complications from the skin and leads to improved functional results.