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When A Patient Has An Equinovarus Contracture Secondary To A Neglected Distal Tibial Fracture
Here the authors present a challenging case that required a tibiotalar arthrodesis and Dwyer osteotomy to address a post-traumatic deformity.
Distal tibial fractures account for less than 10 percent of all lower extremity injuries.1 A multitude of surgical options can address acute injuries, including temporary spanning external fixators, open reduction and internal fixation with osteosynthesis, intramedullary nailing with screw fixation, minimally invasive osteosynthesis and isolated use of external fixation. Neglected fractures can lead to a variety of both short- and long-term problems including but not limited to: malunion; nonunion; limb length discrepancy; varus and valgus contracture at the ankle; post traumatic arthritis; and residual pain. Here, we present a case of a patient with a neglected distal tibial fracture that led to an equinovarus contracture.
When A Patient Presents 40 Years After A Tibial Fracture
A 63-year-old female presented to our clinic with chief complaint of left foot and ankle pain. She stated that she sustained a distal tibial fracture approximately 40 years ago, which was treated conservatively with cast immobilization. Over the past year, the patient has had significant difficulty ambulating, resulting in multiple falls. Her past medical history was significant for hypertension and non-insulin dependent diabetes with no significant symptoms of peripheral neuropathy. Her social and family history were unremarkable.
On physical examination, she had palpable pulses at the dorsalis pedis and posterior tibial arteries. There was an evident varus deformity along the ankle joint with severe pain along the lateral column of her foot. Gait analysis revealed that the patient primarily ambulated on her lateral column (see first two images above). Ankle joint range of motion was considerably decreased and painful. We ordered and reviewed radiographs (see third through fifth images above) and a computed tomography (CT) scan. Severe degenerative changes at the ankle joint, marked angulation and old deformities of the subtalar joint were noted. Distal tibial and fibular deformity secondary to prior fractures were evident.
Due to malreduction of the remote tibial fracture, the patient was in significant varus contracture. We noted a cavovarus deformity as well as recurvatum adaptation of the tibia and fibula. She had a positive Silfverskiold test for gastrocnemius-led equinus. The varus angulation at the level of the ankle joint was likely the reason for the multiple falls that the patient endured in the months leading up to her visit at our clinic. Normal resting arterial perfusion was noted during an arterial brachial index examination. Due to the significant deformity, our team decided to proceed with surgical correction and reconstruction
Pertinent Points In This Patient’s Surgical Process
A Strayer-type gastrocnemius recession addressed the equinus contracture. Intra operatively, the ankle joint appeared severely arthritic and in a rigid varus position. Due to this varus deformity, the tibialis posterior tendon was severely taut. Therefore, we lengthened this tendon in a ‘V’ fashion, allowing increased eversion of the foot. We performed a Dwyer osteotomy to address the varus deformity of the calcaneus. We reserved the bone wedge from this osteotomy for use as an autologous bone graft for the ankle fusion. Once the calcaneus was out of varus, we decided to decompress the tarsal tunnel to prevent impingement of the posterior tibial nerve and other soft tissue structures. The tarsal tunnel release allowed us to proceed with adequate varus reduction at the ankle joint, followed by an ankle arthrodesis performed with an anterior plate. As previously mentioned, we utilized the calcaneal bone wedge as an autologous graft.
A combination of procedures was necessary to correct the multiple complex deformities resulting from her previously neglected fracture. A gastrocnemius recession and posterior tendon lengthening adequately addressed the soft tissue adaptations that had taken place over the progression of the osseous deformity. A Dwyer osteotomy helped shift the calcaneus out of varus while the ankle fusion helped correct the ankle varum deformity. As the foot had adapted over the course of the patient’s lifetime, we felt it necessary to medially release the tarsal tunnel to prevent compression of the nerve root. Postoperatively, the patient was in a below-knee cast for eight weeks while maintaining non-weightbearing status. She transitioned into a CAM boot at eight weeks and proceeded with full weight bearing at that time. She was able to ambulate in a regular shoe at 12 weeks. Physical therapy also began at 12 weeks postop. Thirteen months after the surgery, the patient continued to ambulate pain-free with the ankle joint aligned at 90 degrees to the tibia (see video below).
Understanding The Surgical Rationale And Support In The Literature
This patient presented with a unique deformity. She had a traumatic fracture of her tibia many years ago, with worsening progression. Prior to surgery, the patient experienced multiple falls over the preceding twelve months. This had led to extensive pain which actively hindered her from ambulating. During her pre-operative gait analysis, we noted excessive load her lateral column due to severe hindfoot varus.
Calcaneal osteotomies are a mainstay for treating various deformities of the foot and ankle. The Dwyer osteotomy provides adequate frontal plane correction for a rigid, rear foot-driven, cavovarus foot type.2 This procedure allows one to avoid arthrodesis at the subtalar joint, preserve joint motion, and correct significant varus deformity of the calcaneus.2 Our patient’s deformity included a varus deformity at the calcaneus and the Dwyer osteotomy provide optimal correction. Additionally, the patient had severe varus tilt of the talus on radiographs and CT examination. Intraoperatively, the severe arthritis of the ankle joint with complete cartilaginous destruction warranted an ankle fusion.
Buck and Chao performed biomechanical gait analysis to determine the optimal positioning of an ankle fusion.3 They generated objective data by including the knee during gait analysis. In order to attain optimal function at the knee and ankle joint, the proper positioning for arthrodesis was set at neutral flexion, zero to five degrees of valgus angulation of the hindfoot and five to 10 degrees of external rotation relative to the leg.3 This allows compensatory motion of the foot and prevents excessive loading of the knee.3 This supported our decision for a tibiotalar arthrodesis.Due to the insidious nature of her deformity, the patient demonstrated soft tissue adaptations during her preoperative clinical exam. We addressed the equinus contracture through a gastrocnemius recession. Secondly, her tibialis posterior tendon was extremely taut, which caused us to consider a tarsal tunnel release. Lamm and colleagues hypothesized that angular corrections with osseous realignment could cause excessive stretching or compression to tethered nerve roots.4 Nogeira and team described two types of nerve injuries: acute nerve injuries secondary to surgical trauma; and nerve injuries secondary to gradual distraction.5 Gradual stretching through either limb lengthening or post-traumatic deformity adaptation can lead to nerve injuries.5 Therefore, acute changes in limb length or deformity correction could cause nerve injuries. Lamm and colleagues concluded that performing prophylactic tarsal tunnel release was an important consideration during deformity correction, which supports our surgical decision making.3
One last point to address is preservation of subtalar joint range of motion. Adjacent joint arthritis is commonly reported with hindfoot and ankle fusion procedures6. Performing an ankle and a subtalar joint fusion concomitantly can severely lock up motion of the hindfoot and the ankle6. From a biomechanical perspective, maintaining range of motion in the hindfoot is important. Sealey et al studied long-term effects on 154 patients who underwent isolated ankle arthrodesis.7 This was a radiographic study that compared pre- and postoperative range of motion about the subtalar joint.7 Findings from this study revealed a significant increase in subtalar and medial column range of motion after ankle arthrodesis.7 Preserving range of motion at the subtalar joint can be advantageous during an isolated ankle fusion.7 We do believe that allowing compensatory range of motion at the subtalar joint is unequivocally important following ankle arthrodesis for significant deformity correction.
In Conclusion
Distal tibial fractures can be challenging surgical cases due to severe angulation at the ankle joint. With rigid fixation, patients can still experience angular deformities and arthritis at the ankle joint which can subsequently lead to periarticular arthritis as well. Considering a lateral calcaneal osteotomy in adjacent to ankle arthrodesis can provide adequate correction. In addition, addressing soft tissue adaptations should be considered vital to deformity correction in these individuals. One must also consider prophylactic tarsal tunnel release and tendon lengthening procedures when indicated. This case report is representative of such decision-making processes.
Dr. Kissel is board-certified by the American Board of Foot and Ankle Surgery and is in practice in Southeast Michigan.
Dr. Shamim is a second-year podiatric resident at Detroit Medical Center in Detroit.
1. Sitnik A, Beletsky A, Schelkun S. Intra-articular fractures of the distal tibia: current concepts of management. EFORT open reviews. 2017;2(8):352-361.
2. Barg A, Hörterer H, Jacxsens M, Wiewiorski M, Paul J, Valderrabano V. Dwyer-osteotomie: laterale verschiebeosteotomie des kalkaneus [Dwyer osteotomy : lateral sliding osteotomy of calcaneus]. Oper Orthop Traumatol. 2015;27(4):283-297.
3. Buck P, Morrey BP, Chao EY. The optimum position of arthrodesis of the ankle. A gait study of the knee and ankle. J Bone Joint Surg Am. 1987;69(7):1052-1062.
4. Lamm BM, Paley D, Testani M, Herzenberg JE. Tarsal tunnel decompression in leg lengthening and deformity correction of the foot and ankle." J Foot Ankle Surg. 2007;46(3):201-206.
5. Nogueira MP, Paley D, Bhave A, Herbert A, Nocente C, Herzenberg JE. Nerve lesions associated with limb-lengthening. J Bone Joint Surg Am. 2003;85:1502–1510.
6. Cho BK, Park KJ, Choi SM, Kang SW, Lee HK. Ankle Fusion Combined With Calcaneal Sliding Osteotomy for Severe Arthritic Ball and Socket Ankle Deformity. Foot Ankle Int. 2016;37(12):1310-1316.
7. Sealey RJ, Myerson MS, Molloy A, Gamba C, Jeng C, Kalesan B. Roger Mann Award 2008: sagittal plane motion of the hindfoot following ankle arthrodesis: a prospective analysis. Foot Ankle Int. 2009;30(3):187-196.
