|Beitragstitel||Z-lengthening Plasty of the Extensor Hallucis Longus (EHL) Tendon Proximal to the Retinaculum Extensorum to Repair a Chronic Rupture of the Distal EHL Tendon.|
Background: Extensor hallucis longus (EHL) tendon injuries are rare. End-to-end suture is used in acute lacerations or in chronic cases when the tendon stumps are close enough to be attached without excessive tension. If a non-reducible gap exists between the tendon edges, a reconstruction with a graft or a transfer may be necessary to restore the hallux alignment and active dorsiflexion. We present the surgical technique and the post-operative follow up of our method to repair a traumatic EHL rupture with a non-reducible gap by using a Z-lengthening of the EHL tendon proximal to the superior retinaculum of the extensors.
Method: We used two incisions, one at the level of the rupture and the other proximal to the retinaculum of the extensors. After the preparation, we measured the distal gap between the stumps. We then identified the EHL tendon through the proximal approach and lengthened it with a Z-shaped incision to gain the needed length distally. End-to-end suture could then be performed at the level of the rupture, without tension. Full weight bearing in a lower leg cast was allowed 24 hours after surgery. After two weeks, the patient received a dynamic splint with a dorsiflexion counter spring for another 4 weeks. After 6 weeks, normal shoes were allowed and physical therapy was started consisting in sessions with progressive active training twice a week for another 6 weeks. The muscle strength was estimated clinically at 6 weeks and 3 months in comparison to the healthy side. AOFAS, FAAM and EQ 5D 5L scores were administered at 3 months postoperatively.
Results: At 3 months, our patient recovered an active hallux extension of 50° at the metatarsophalangeal joint (60° on the healthy side). There was no loss of active or passive plantarflexion in the metatarsophalangeal or interphalangeal joint. There were no wound complications. We observed no dysfunction and no secondary deformities of the foot at follow up. The FAAM score was 83/84 (activities of daily living) and 12/12 (sports). The AOFAS was 90/100 and the EQ-5D was 0.8.
Discussion: This repair of the EHL using a Z-lengthening plasty of the tendon proximal to the retinaculum has not been previously described. Based on our case this technique appears safe, simple and affordable to treat the EHL ruptures if the end-to-end direct suture is not possible, thus eliminating the need for an allograft or the risk of secondary dysfunctions potentially associated with tendon transfer procedures.