Remplissage Using Tendon Graft Can Improve Impaired Suction Seal Caused by Over-resection During Femoroplasty in an Ovine Model.

Purpose: To evaluate the effect of depth and location of femoral osteoplasty or the use of remplissage on the suction seal in a sheep hip model.

Methods: The hips of 32 twelve-month-old sheep were used as a cam-type femoroacetabular impingement model. The subjects were divided into 4 groups, each undergoing a distinct surgical procedure: group I underwent a 5% cam resection at the head/neck junction, group II had a 10% cam resection at the head/neck junction, group III received a 5% cam resection from 5 mm proximal to the head/neck junction, and group IV underwent remplissage to replace the loss of the suction seal with an extensor tendon graft in the defected area after a 10% cam resection at the head-neck junction. Each specimen was subjected to a compression force of 200 N before the surgical procedure, followed by distraction. After surgery, the same biomechanical test was conducted on each sample, and the average peak force was calculated.

Results: Suction seal force was statistically significantly lower in all groups compared with the intact state before the surgical procedure. The maximum decrease in suction seal force after the surgical procedure was observed in the 10% resection group. However, in the remplissage procedure after 10% resection, the suction seal force exceeded the value in the 5% resection group and even reached the value in the intact state. Although proximal over-resection affects suction seal force, we found that an increase in depth had a more significant impact on suction seal force than proximal over-resection.

Conclusions: The most significant decrease in the suction seal was observed in the group with 10% cam resection compared with the 5% cam resection and proximal over-resection groups. Remplissage using tendon grafts significantly enhanced the suction seal in the 10% resection group in the ovine model. CLINICAL RELEVANCE: This study offers experimental evidence on how femoral osteoplasty depth affects the suction seal, building on previous research on the labrum. Remplissage may provide an alternative solution to the irreversible effects of excessive resection by reversing the suction seal effect.