Ultrasonographic Evaluation of the Early Healing Process After Achilles Tendon Repair

Overexpression of CGRP receptor attenuates tendon graft degeneration in anterior cruciate ligament reconstruction

Cell apoptosis or necrosis, extracellular matrix loss, and excessive inflammation may induce tendon graft degeneration. The impairment in the regeneration capability of nerve fibers and blood vessels may be the critical cause. Calcitonin gene-related peptide (CGRP), exhibiting a short half-life, favors cell proliferation, nerve fiber regeneration and angiogenesis. We aimed to investigate the effects of CGRP receptor-mediated signaling on tendon graft integrity and study if the modulation pathways are ascribed to cell proliferation, nerve fiber and blood vessel regeneration. A total of three groups in mice with ACL reconstruction were established: the control group (PBS treatment), the adenovirus vectors expressing CGRP receptor (CALCRL) treated group (Adv-Calcrl treatment), and the adenovirus vectors carrying shRNA targeting Calcrl treated group (Adv-shCalcrl treatment). The histological assessment indicated the Adv-Calcrl treatment was favored while the Adv-shCalcrl significantly impaired tendon graft integrity. TUNEL staining revealed a significant decreased number of apoptotic cells in the Adv-Calcrl group relative to the control group and the adv-shCalcrl group. Compared to the control group and the Adv-shCalcrl group, the Adv-Calcrl group showed significantly enhanced proliferation of nestin positive cells. Of note, the Adv-Calcrl treatment significantly increased EMCN expression at the tendon graft relative to the control and the Adv-shCalcrl groups, which may be ascribed to attenuation of the Hippo signaling pathway. Importantly, the Adv-Calcrl treatment significantly increased sensory nerve fibers and also PIEZO2 levels. Our results demonstrate the activation of CGRP receptor-mediated signaling attenuated tendon graft degeneration, which was ascribed to enhanced proliferation of Nestin positive cells, angiogenesis, and nerve fiber outgrowth.

Conservative treatment outcome for Achilles tendon re-rupture occurring in the subacute phase after primary repair

INTRODUCTION

Until now, a treatment protocol for Achilles tendon re-rupture (ATRR) occurring in the postoperative period 5-12 weeks following primary Achilles tendon repair has not been established. We refer to this time frame as the subacute postoperative phase, and the objective of this study was to assess the efficacy of conservative treatment for subacute ATRR in this phase.

MATERIALS AND METHODS

We conducted a retrospective review of 390 cases (385 patients) who had undergone primary Achilles tendon repair using the 4-strand Krachow method between January 2010 and August 2021. All patients were subjected to more than 12 months of follow-up and were categorized into two groups based on the presence of subacute ATRR: Group 1 comprised 370 cases without ATRR, while Group 2 comprised 20 cases with ATRR. Following confirmation of ATRR, we immediately applied a below-knee cast in an ankle plantar flexed position (25°-30°), followed by bracing according to the same rehabilitation plan used for the primary repair. After administering conservative treatment to the patients with ATRR, we compared several outcome parameters between the two groups, including isokinetic plantar flexion power measured using a dynamometer, time required for a single heel raise (t-SHR), time needed for ten repetitive SHRs (t-SHR10), Achilles Tendon Total Rupture Score (ATRS), and Foot and Ankle Ability Measure (FAAM) scores. The baseline timepoints for Groups 1 and 2 were the dates of the primary repair and the re-injury event.

RESULTS

After primary Achilles tendon repair, subacute ATRR occurred in 5.1% of patients. There were no significant differences between the groups in terms of t-SHR and t-SHR10 (P = 0.281, 0.486). Similarly, the isokinetic dynamometer measurements revealed no significant differences in peak torque for plantar flexion at angular velocities of 30°/s and 120°/s, both in absolute values and as a percentage of the contralateral side, between the groups (P > 0.05 for each). However, ATRSs were significantly lower in Group 2 compared to Group 1 before 6 months (P < 0.05), as were FAAM-Activities of Daily Living scores at 6 months (P < 0.05). After 12 months, there were no significant differences in these scores between the two groups (both P > 0.05).

CONCLUSION

Conservative treatment for subacute ATRR following primary Achilles tendon repair yields clinical outcomes comparable to those without ATRR. Therefore, we recommend that surgeons consider relying on the patient's natural healing capabilities rather than opting for aggressive surgical interventions, as expediting such operations may be unnecessary for subacute injuries.

Early Tendon Morphology as a Biomarker of Long-term Patient Outcomes After Surgical Repair of Achilles Tendon Rupture: A Prospective Cohort Study

Background

Patient outcome after acute Achilles tendon rupture (ATR) varies and is difficult to predict. Whether early variations in healing, visualized with ultrasonography, can predict long-term patient outcome is unclear.

Purpose

To (1) examine the associations of Achilles tendon cross-sectional area (CSA) and elongation (TE) during healing of ATR repair with patient outcomes at 12 months postoperatively and (2) investigate the predictive or diagnostic capacity of the morphological biomarkers.

Study Design

Cohort study; Level of evidence, 2.

Methods

This study was based on previously collected data from 86 patients who underwent acute standardized ATR repair between 2013 and 2018 and who were included in a prior randomized trial investigating early functional mobilization (EFM). In the EFM group, loading was allowed immediately after surgery, while in the comparison group, loading was allowed first at 2 weeks postoperatively. Achilles tendon CSA and length were measured with ultrasound at 6 weeks, 6 months, and 12 months postoperatively. CSA ratio and absolute difference in the length of the healthy and injured tendons were calculated. Patient-reported outcome was registered with the validated Achilles tendon Total Rupture Score and functional outcome with the heel-rise endurance test at 12 months postoperatively. The limb symmetry index (LSI) was calculated for maximum heel-rise height (HRHmax) and total concentric work. Multiple linear regression adjusted for age was used, and the area under the receiver operating characteristic curve (AUC) was calculated to evaluate predictive capacity.

Results

A larger CSA ratio at 6 weeks was associated with higher LSI HRHmax at 12 months (R2, 0.35; P < .001) and exhibited good predictive capacity (AUC, 0.82). More TE at 12 months was associated with lower LSI total concentric work at 12 months (R2, 0.21; P = .001) and exhibited acceptable predictive capacity (AUC, 0.71).

Conclusion

Greater Achilles tendon CSA seen on ultrasound 6 weeks after surgical repair had good clinical prediction for long-term functional outcome. TE at 12 months was predictive of inferior functional outcome.

Registration

NCT02318472 (ClinicalTrials.gov identifier).

Poly (trimethylene carbonate)/doxycycline hydrochloride films in the treatment of Achilles tendon defect in rats

Introduction: In this study, Poly (trimethylene carbonate)/Doxycycline hydrochloride (PTMC/DH) films were introduced to repair the Achilles tendon defects for the first time. Methods: (PTMC/DH) films with different DH content of 10, 20, and 30% (w/w) were prepared by solvent casting. The in vitro and in vivo drug release of the prepared PTMC/DH films was investigated. Results: The results of drug release experiments showed that the PTMC/DH films released effective concentrations of doxycycline for more than 7 and 28 days in vitro and in vivo, respectively. The results of antibacterial activity experiments showed diameters of 25.00 ± 1.00 mm, 29.33 ± 1.15 mm, and 34.67 ± 1.53 mm, respectively, for the inhibition zones produced by the release solutions of PTMC/DH films with 10, 20 and 30% (w/w) DH at 2 h, indicating that the drug-loaded films could inhibit Staphylococcus aureus well. After treatment, the Achilles tendon defects have recovered well, as indicated by the more robust biomechanical properties and the lower fibroblast density of the repaired Achilles tendons. Pathology revealed that the pro-inflammatory cytokine, IL-1β, and the anti-inflammatory factor, TGF-β1, peaked in the first three days and gradually decreased as the drug was released more slowly. Discussion: These results demonstrated that the PTMC/DH films have great potential for regenerating Achilles tendon defects.

Repair of acute Achilles tears with plantaris augmentation

PURPOSE

To determine the benefits associated with using the fanned out plantaris tendon as a membrane to cover and augment the acute Achilles tendon midportion end-to-end suture repair.

METHODS

Between 2014 and 2018, 31 (67.4%) patients had plantaris augmented reconstruction and 15 simple end-to-end suture. The clinician filled out the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale and the patient the Achilles tendon total rupture score (ATRS). Examination included clinical examination, limb symmetry index (LSI) using the heel rise test, and ultrasound determination of cross-sectional area (CSA).

RESULTS

80.4% were males, mean age 41 (SD 6.7, range 29-57), of which 82.6% were sports accidents. 39/46 were operated in less than two weeks from injury. 82.6% were available at the two year follow-up. Duration of surgery (62.3 min vs 58, p = 0.45), AOFAS (89.6 vs 88.4, p = 0.61 and 97.2 vs 96.8, p = 0.72), ATRS (86.3 vs 83.8, p = 0.33 and 95.6 vs 93.6, p = 0.12), LSI (60.8% vs 58.75, p = 0.24 and 80.5 vs 79, p = 0.29), CSA (3.39cm² vs 3.36, p = 0.82 and 2.57 vs 2.59, p = 0.87), return to sport (80% vs 57, p = 0.15 and 84.6 vs 85.7, p = 1.00), and complications at six months and two years were comparable between the two techniques.

CONCLUSION

Fanned out plantaris augmentation of acute Achilles tendon tears yields excellent and comparable clinical and ultrasonographic results to end-to-end suture at mid-term follow-up.

Serial Ultrasonographic and Real-Time Elastosonographic Assessment of the Ovine Common Calcaneal Tendon, after an Experimentally Induced Tendinopathy

Real-time elastosonography (RTE) is a recently described, non-invasive, ultrasonographic technique developed to assess tissue elasticity. The main aim of this study was to investigate the ultrasonographic and elastosonographic appearance of the common calcaneal tendon (CCT) in an ovine model, and to monitor the progression of tendon healing after an experimentally-induced tendinopathy. Sound tendons were initially evaluated (T₀) with a caliper and by a single operator with ultrasound. Ultrasonographic and elastosonographic images were then acquired. Subsequently, ultrasound-guided tendon lesions were induced by injecting 500 IU of Type IA collagenases proximally to the calcaneal tuberosity. Caliper measurement, ultrasonography and elastosonography were then repeated at 15 (T₁), 30 (T₂) and 60 (T₃) days. Clinically measured width of the tendon, ultrasonographic thickness and width and percentage of hard (Elx-t%hrd) and soft (Elx-t%sft) tissue were recorded. Statistical analysis was performed on the data collected; statistical significance was set at p < 0.05. Intra-class correlation coefficient (ICC) revealed good (0.68) repeatability of elastosonographic evaluation of the CCT. The tendon width was significantly increased when comparing T₀ with T_1–2 and decreased when comparing T_1–2 with T₃. Ultrasound-assessed thickness was significantly increased between T₀–T₁ and decreased between T₁-T_2–3. Elx-t%hrd was significantly decreased at T_1–2–3 and Elx-t%sft was significantly increased at T_1–2–3. In conclusion, the ovine CCT is a highly stiff structure that undergoes a severe loss of stiffness during the healing process. Thickness and width of the tendon increased during the first 30 days and then reduced progressively along the subsequent 30 days. Ultrasonographic appearance of the tendon remained severely abnormal and the tendon showed severely reduced elastic proprieties 60 days after lesion induction.

Changes in Tendon Elongation and Muscle Atrophy Over Time After Achilles Tendon Rupture Repair: A Prospective Cohort Study on the Effects of Early Functional Mobilization

BACKGROUND

Early functional mobilization (EFM) may improve patient outcome after Achilles tendon rupture (ATR). However, whether EFM affects patient outcome via changes in tendon elongation, thickening, or calf muscle atrophy is unknown.

PURPOSE

To analyze differences in tendon and muscle morphology recovery over time between groups treated with EFM or standard treatment after ATR repair.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This prospective cohort study included 86 patients (20 women) with ATR repair who had a mean (SD) age of 39.3 (8.2) years and were part of a larger prospective randomized controlled trial. Patients were postoperatively randomized to immediate postoperative weightbearing and ankle motion (EFM group) or to immobilization in a below-knee plaster cast for 2 weeks (control group). Patient-reported and functional outcomes were assessed at 6 and 12 months with the Achilles Tendon Total Rupture Score and the heel-rise test for endurance. At 2 and 6 weeks and 6 and 12 months postoperatively, B-mode ultrasound imaging was performed to assess the length and cross-sectional area (CSA) of the Achilles tendon, the gastrocnemius CSA, as well as the thickness of soleus.

RESULTS

The Achilles Tendon Total Rupture Score for the EFM and control groups were 65.8 (18.7) and 56.8 (20.1; P = .045), respectively, at 6 months and 79.6 (15.8) and 78.9 (17.2; P = .87), respectively, at 12 months. At 2 weeks, tendon elongation was significantly more pronounced in the EFM group as compared with the control group (mean side-to-side difference, 1.88 cm vs 0.71 cm; P = .005). Subsequently, tendon elongation increased in the control group while it decreased in the EFM group so that at 6 and 12 months no significant differences between groups were found. Mean Achilles tendon elongation at 1 year was 1.73 (1.07) cm for the EFM group (n = 55) and 1.67 (0.92) cm for the control group (n = 27), with a mean difference of 0.06 cm (95% CI, 0.54 to -0.42; P = .80). Achilles tendon CSA and calf muscle atrophy displayed no significant differences between the groups; however, significant changes were demonstrated over time (P ≤ .001) in both groups.

CONCLUSION

EFM results in more Achilles tendon elongation at early healing, but this difference subsides over time. EFM does not seem to affect patient outcome via changes in tendon elongation, thickening, or calf muscle atrophy.

REGISTRATION

NCT02318472 (ClinicalTrials.gov identifier).