AOAO News

The Orthopod

The Official Publication of the
American Osteopathic Academy of Orthopedics

Abstracts

Dynamic Extension Deformity of the Extensor Hallucis Tendon: A Case Report
Authors: KJ Holmberg1, P Vyas2, AD Bitterman3

Affiliations: Allegheny Health Network Department of Orthopaedic Surgery1, Washington University-Barnes Jewish Hospital2, Zucker School of Medicine at Hofstra / Northwell Health3

Introduction: We report a case of an acquired dynamic extension deformity of the hallux presenting several months after a closed right tibial shaft fracture. This is a rare condition with few reports documented in the literature. The goal of this report is to review the literature and discuss the surgical treatment of an acquired dynamic deformity of the EHL tendon.

Methods: A 19-year-old male sustained a closed right tibial shaft fracture while playing soccer. The patient underwent intramedullary nailing of the tibia. His postoperative course was complicated by a dorsiflexion deformity of the hallux. The physical exam consisted of a dynamic cock-up deformity of the hallux with plantarflexion of the ankle. The patient failed a trial physical therapy and shoe modifications and was referred to the Foot and Ankle Service where surgical correction was recommended. A dorsal approach to the first metatarsal was utilized with a 6-centimeter incision centered over the extensor hallucis longus (EHL) tendon. Significant adhesions were noted around the EHL tendon preventing it from gliding in its sheath. Additionally, there was significant contracture of the tendon. At this point, we released all the adhesions and proceeded with Z-plasty and lengthening.

Results: Upon completion, the toe was immediately able to achieve normal posture. The hallux and the foot were taken through passive plantarflexion and dorsiflexion intraoperatively, which demonstrated resolution of the deformity and the hallux had good resting tone.

Discussion: Tethering of the EHL, causing what has been referred to as dynamic positional deformity of the hallux, is a rare cause of hallux pathology1. Several surgical treatment options for the correction of such deformities have been described in the literature, including the release of adhesions, tenolysis, tendon transfer, and lengthening with Z-plasty1,2,3. Our patient was treated with Z-plasty of the EHL at the level of the midfoot with pinning of the first interphalangeal joint to protect our repair and allow healing. This provided immediate correction of the deformity confirmed by intraoperative examination. While further follow up is needed, our approach of lengthening with Z-plasty seems to have achieved good clinical results and is consistent with published reports1,2,3.

References:

  1. Cho BK, Kim YM, Kim DM, Choi ES, Park JK, Oh JW. Dynamic Positional Deformity of the Hallux. Journal of Foot & Ankle Surgery. 2014; 53:791 – 793.
  2. Heo YM, Roh JY, Kim SB, Kim JY, Lee JB, Kim KK.   Contracture of Extensor Hallucis Longus Tendon Occurring after Intramedullary Nailing for a Tibial Fracture.   J Korean Orthop Assoc. 2010 Oct;45(5):399-403.
  3. Lee H. S., Kim J. S., Park S.-S., Lee D.-H., Park J. M., and Wapner K. L. Treatment of checkrein deformity of the hallux. The Journal of Bone and Joint Surgery. British volume 2008 90-B:8, 1055-1058