In the period January-December 2020, we treated five patients (four males and one female) for chronic/misdiagnosed Achilles tendon injuries. Their age ranged from 35 to 78 years.
Three patients were still in work and engaged in leisure-time sports activities. All patients had not recovered functionally and clinically after trauma that occurred at least four-six weeks prior to orthopaedic evaluation. Reduction in function was accompanied by pain in the hindfoot and edema of the calf. In view of the marked deterioration in Quality of Life (QoL) reported by all patients and in absence of absolute contraindications, we placed no age limits on surgical indication.
The surgical procedure involves performing tenorrhaphy with Bunnel technique reinforced using an allograft, in the form of a patch of decellularized dermis, and stimulating the regeneration process by infiltrating the construct with PRP and thrombin homologues.
We planned the intra- and post-operative phase, focusing on some aspects:
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precise pre-operative quantization of pathological tendon anatomy;
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evaluation of mechanical and biological characteristics of available and usable
augmentation systems;
based on the quality of the repair obtained, we customized the post-operative program
trying to apply the modern concepts of optimal loading and neuromiofunctional recovery of the kinetic chains;
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at least 1.5 years follow-up evaluation of clinical/functional and anatomical results obtained.
Pre-operative pathological anatomy quantization. All patients underwent an ultrasound study, a nuclear magnetic resonance imaging and digital X-ray in anterior-posterior and lateral-lateral projection in load. We treated three lesions of the achilles midportion and one pre-insertion lesion with fibers disruption in the axial plane. One lesion involved the tendon midportion with fibers rupture in the coronal plane, configuring a tendon slippage. (Fig. 2c) Mechanical/biological characteristics of the augments used. We performed mechanical (and also biological) augmentation using as biomaterial a decellularized dermis allopatch (provided by the dermis bank of our health institution). Allopatches can be requested in various sizes (width and length in cm) and thickness (< 1 mm->2 mm).
We thought of increasing the regenerative potential by exploiting the growth factors released by thrombin- activated PRP, both homologous. (12) The numerous and well-known growth factors released upon PRP injection are added to those already present in dermal allopatch (PGF Beta). (15) The surgical technique performed involves the following steps: from tenorrhaphy to double one-step augmentation. Patient in prone decubitus and pneumo-ischemic tourniquet at the root of the limb, we approached the tendon lesion with a medial para-tendon incision. After careful dissection of the subcutaneous layers, we attempted to isolate the peritenonium. After removal of the fibrous scar tissue and organized hematoma at the level of the focus of chronic tendon injury, “quantization” of the same was performed by assessing the retraction of the stumps, adherence to the surrounding tissues and the degree of fibrillar degeneration. In complete transverse lesions on axial plane, we performed end-to-end tenorrhaphy by Bunnel technique. In all cases we were able to suture the tendon without leaving a gap between the stumps, seeking, because deemed useful, an “optimal shortening” repair of the tendon.
In order to provide greater resistance to tension/traction stresses of the tenorrhaphy, in light of the severe tendon destructuring, we performed an onlay augmentation. The repaired tendon was wrapped with decellularized dermis allopatch. The suture of the allopatch to the tendon was performed with absorbable #3.0 thread trying to make it as tight as possible to the tendon. Then, an attempt was made to suture the peritenonium, previously isolated, to the allopatch in order to optimize vascular support to the construct.
At the end of tenorrhaphy/onlay augmentation, we performed infiltration of the “tendon repair biological chamber” with one unit (6 cc) of PRP activated with 2 cc of thrombin, both homologous. In lesion with tendon slippage at the midportion we performed tenorrhaphy and simultaneous augmentation, interposing an allopatch “tape” (same width as the Achilles tendon) between the tendon stumps. In addition to this inlay reparative technique (wafer like repair), we performed an onlay augmentation. As described above, we sutured the peritenonium and infiltrated an activated homologous PRP unit. (Fig. 1–6)
In all cases, suture of the skin was performed without excessive tension because the deformation of the anatomical profile of the tendon at the end of the procedure was not such as to represent a skin covering problem. After applying a hydrofiber dressing, we used, in all cases, a boot with a series of wedges inside (3 wedges) to ensure equinization of approximately 30°. Post-operative Protocol. In every patients, we obtained a construct considered solid and able to be solicited according to the most modern rehabilitation concepts like regenerative rehabilitation (14) The post-operative rehabilitation program must be able to combine “respect”' of the tendon healing process and optimal loads, which have proven to be “regenerative” for the tendon. Generally, the re-educational steps follow one after the other, according to the objectives that have been anticipated and achieved, taking into account that joint and muscle work must not trigger pain. Final objectives are recovery of ROM (especially of ankle and knee), strength of all the elements of kinetic chain, normal motor and functional patterns, and at the end return to activity, to play and to sport.
We’ve banned all patients from loading for 10 days. After that, patients can walk with full weight bearing and pain tolerance. Every 7 days, a wedge is removed from the walker. Once all three wedges have been removed, patients begin a dry and in-water functional re-education program. For 15 days after performing exercises, patients reapply the walker. On the 45th day, patients completely remove walker and continue the functional re-education program of the district and kinetic chains. Postoperative instrumental evaluation at least 8 months after surgery was conducted employing the elastosonographic technique and dynamic perfusion MRI study. The elastosonographic technique integrates the classic B-Mode ultrasound study, which is useful for the evaluation of the fibrillar structure of the tendon, with data inherent biomechanical properties (stiffness and elasticity) of the tissues. The elastosogram with gradations of blue to indicate tendon stiffness of the repaired tissue similar to physiological stiffness and red to indicate instead suboptimal stiffness and thus greater tendency for elongation with consequent risk of tendon damage (tissue not yet fully "regenerated"). (16) (Fig. 7)
The dynamic perfusion rmn study was performed by T1 scanning repeated several times over time after intravenous injection of paramagnetic contrast agent (gadolinium), which progressively accumulates in the extracellular space with a rate determined by the phenomena of perfusion and capillary permeability and correlated with vascular surface area. The dynamic rmn study integrates the conventional study with a quantitative analysis of contrast medium uptake after processing through specific models. These analyses are very useful already at the first scheduled checkup by comparing the treated tendon with healthy tissue. They are also useful especially in subsequent checks at a distance of time in order to evaluate the evolution of "regenerative" processes. Dynamic contrastographic MRI study allows an assessment of enhancement that testifies to the extent and degree of granulation tissue maturation related to the reparative and graft integration phenomena. (17) (figure 8)
A good correlation between elastosonographic and rmn data was observed in defining regions of decreased stiffness and increased perfusion indices that were considered representative of a still evolving process of allopatch integration and maturation and "tendon regeneration."