[Achilles tendon rupture-Part 1: etiology and diagnostics]

Effects of Knee Joint Angle and Contraction Intensity on the Triceps Surae Stiffness

Purpose: Monitoring the contractility of muscles assists the clinician in understanding how muscle functions as part of the kinetic system. This study investigated the effect of knee joint angles under different resistance on the stiffness of the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) muscles using the shear wave elastography (SWE) technique.

Methods: A total of 22 females were recruited. During isometric plantar flexion, at knee 0-degree (fully extended) and knee 90-degree (flexed 90°), the shear modulus on the MG, LG, and SOL was measured by shear wave elastography at no contraction and two intensities (40% and 80%) of maximal voluntary contraction (MVC). Shear modulus is a mechanical parameter to describe stiffness, and stiffness is a proxy for muscle contractility.

Results: There were moderate-to high-positive correlations between the active stiffness of triceps surae muscles and isometric contraction intensity (r: 0.57–0.91, p＜0.001). The active stiffness in MG and LG with extended knees was higher than that with flexed knees (p＜0.001). The active stiffness in SOL with flexed knee was higher than that with extended knee (p＜0.001).

Conclusion: Active stiffness can be considered a quantitative indicator generated by the force output of the triceps surae. Different knee joint angles cause three triceps surae muscles to exhibit non-uniform mechanical properties, which may explain part of the mechanism of soft tissue injury during physical exercise.

Higher pyruvate levels after Achilles tendon rupture surgery could be used as a prognostic biomarker of an improved patient outcome

PURPOSE

The primary aim of this study was to assess the relationship between the metabolites lactate and pyruvate in the healing tendon after Achilles tendon rupture (ATR) and patient-reported outcome at 6 and 12 months. A secondary aim was to evaluate which underlying factors regulate lactate and pyruvate concentrations.

METHODS

Lactate and pyruvate concentrations were measured two weeks post-operatively in both the healing- and healthy Achilles tendon in 109 patients (90 men, 19 women; mean age 40 ± 7.9 years). Patient demographics, degree of physical activity, timing of surgery, operation time, patient-reported loading and step counts were investigated in relation to metabolite concentrations. At 6 and 12 months, the Achilles tendon Total Rupture Score (ATRS) questionnaire was used to assess patient outcome.

RESULTS

The mean number of steps taken during the post-operative days 1-10 was the only factor significantly related to the mean concentration of lactate (R² = 0.34, p = 0.038), and pyruvate (R² = 0.46, p = 0.006). Pyruvate was demonstrated as the only factor significantly associated with ATRS at both 6 months (R² = 0.32, p = 0.003) and at 12 months (R² = 0.37, p = 0.004) using multiple linear regression.

CONCLUSION

The mean concentration of pyruvate during early ATR healing may predict patient outcome at 6 and 12 months post-operatively and possibly be used as a biomarker of healing. Early mobilization with an increased number of steps taken is an important clinical strategy to improve the metabolite concentrations during healing.

LEVEL OF EVIDENCE

III.

[Clinical analysis of autogenous tendon reconstruction under total arthroscopy in treatment of chronic Achilles tendon rupture]

Objective

To investigate the effectiveness of autogenous tendon reconstruction under total arthroscopy in the treatment of chronic Achilles tendon rupture.

Methods

Between June 2015 and June 2018, 16 patients with chronic Achilles tendon ruptures were treated by autogenous tendon reconstruction under total arthroscopy. Of the 16 patients, 11 were males and 5 were females. Their mean age was 40.7 years (range, 21-55 years). The disease duration was 14-20 months (mean, 16.4 months). Preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score was 41.2±2.2 and the pain visual analogue scale (VAS) score was 7.9±1.2. MRI and B-ultrasonography examinations showed that the Achilles tendon was not continuous. The length of Achilles tendon defect was 5.0-10.3 cm, with an average of 5.8 cm. The rupture of the Achilles tendon happened on top of the insertion of the tendon in 4 cases and at the tendon-muscle belly connection in 12 cases. The operation time, intraoperative blood loss, hospital stay, and related complications were recorded. The AOFAS score and VAS score were used to evaluate the improvement of ankle joint function and pain.

Results

The average operation time was 77.2 minutes (range, 60-90 minutes). The average intraoperative blood loss was 20.5 mL (range, 15-30 mL). The average hospital stay was 7.2 days (range, 5-10 days). All incisions healed by first intention. There was no skin necrosis, infection, or deep vein thrombosis. All the patients were followed up 8-18 months, with an average of 12 months; and 10 cases were followed up more than 12 months. During the follow-up, there was no Achilles tendon re-rupture, and the symptoms of pain and heel lifting failure significantly improved. MRI reexamination showed that the continuity of Achilles tendon recovered. At 1, 3, 6, and 12 months postoperatively, AOFAS scores significantly improved and VAS scores significantly reduced, except for 1 month postoperatively, the scores at other time points were superior to that before operation, the differences were significant ( P<0.05).

Conclusion

Autogenous tendon reconstruction under total arthroscopy in the treatment of chronic Achilles tendon rupture has the advantages of small trauma, rapid functional recovery, and satisfactory surgical efficacy.