The Possibilities of Ultrasound in Monitoring Wound Healing of the Donor Site after Plasty of the Anterior Cruciate Ligament

Purpose: To monitor with ultrasound the healing of the donor site after the formation of an anterior cruciate ligament (ACL) graft of the middle third patellar ligament (bone-tendon-bone [BTB]) and the semitendinosus (ST) tendon of the thigh muscle.

Methods and Materials: A total of 40 patients (BTB: 20; ST: 20) were examined 1, 3, and 6 months after arthroscopic reconstruction of the ACL performed at the Institute R. R. Vredena from 2005 to 2009. Ultrasound was performed on the Siemens apparatus, a linear converter (7.5–10 MHz) in real time. In the first group, the structural state of the patellar ligament and the degree of defect closure were assessed. In the second group, the presence or absence of regeneration was assessed at the anatomical site of the hamstring.

Results: In the BTB group in all patients after 1 month, the thickening of the lateral segments of the patellar ligament with the preservation of the defect in the place of the graft intake was visualized. After 3 months, the ligament was visualized with the restoration of the external and internal contour. The defect was identified by the formed scar tissue with signs of linear structure (three patients had incomplete closure of the defect). Transverse scanning showed ligament deformation, the so-called butterfly effect, due to edema and heterogeneity of the echo structure of the lateral parts of the ligament (18%: had tendinitis). After 6 months, the deformation of ligaments was preserved, due to the reduction of the width of the defect and moderate edema of the lateral fragments; the regeneration was represented by a site of reduced echogenicity with a clear linear structure of collagen fibers. Three patients (15%) had defects in the regeneration itself.

In the ST group, retraction and violation of the tendon muscle pattern was apparent in all patients 1 month after surgery. At the anatomical site of the tendon, taken between the sheets of superficial and deep fascia, 87% of patients had a hypoechogenic structure with fuzzy contours (organized hematoma). After 3 months, the donor site was represented by regeneration (“neo-tendon”), a wide thread of immature scar tissue reaching the articular slit of the knee joint. Scar tissue was not visualized in two patients. After 6 months in 87% of patients, the defect from the tendon-muscular part to the level of the articular slit was filled with mature scar tissue, resembling a tendon structurally.

Conclusion: The healing processes of the maternal bed in both groups were similar to the replacement of defects in 6 months after surgery with scar tissue with a clear linear structure, but 15% of patients in the BTB and 13% in the ST group did not achieve a complete recovery. The ultrasound results showed the possibility of monitoring the healing of the donor area after autoplasty to optimize the rehabilitation protocol.