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Talectomy and tibio-calcaneal fusion using Wright Ortholoc posterior TTC fusion plate

    Overview

    Learn the Talectomy and tibio-calcaneal fusion using Wright Ortholoc posterior TTC fusion plate surgical technique with step by step instructions on OrthOracle. Our e-learning platform contains high resolution images and a certified CME of the Talectomy and tibio-calcaneal fusion using Wright Ortholoc posterior TTC fusion plate surgical procedure.
    Pes planus is the deformity of the foot characterised by loss of the medial longitudinal arch with the foot under loading. More often than not, the hindfoot also lies in valgus deriving the term pes planovalgus. Secondary features of this deformity are that there may be a compensatory supination deformity of the midfoot and the Achilles tendon tightens and effectively becomes shorter in length.
    There are multiple causes of pes planovalgus that can broadly be separated into congenital (eg tarsal coalition, hypermobility syndromes) and acquired groups. In adults, acquired pes planovalgus is most often seen with posterior tibial tendon dysfunction or with inflammatory arthopathies. Careful assessment of the patient’s symptoms and signs is necessary to guide the treatment options available for each individual patient.
    Talectomy and tibiocalcaneal fusion is not a common procedure for pes planovalgus. Historically, it is more often associated with the management of fixed equinovarus deformities in childhood (eg arthrogryposis, post CTEV), Charcot arthropathy or post-traumatic deformity (invariably secondary to the loss of the talus). In this particular case, a 65 year old lady with rheumatoid arthritis presented with a stiff, painful flat foot. All footwear modifications had failed to relieve her symptoms.

    Indications

    INDICATIONS
    The principle symptom that patients present with is pain. However, patients also complain of deformity and swelling which can be difficult to cater for in standard footwear. The indications for surgery are when non-operative measures have failed or been exhausted.
    SYMPTOMS & EXAMINATION
    Pain is the foremost symptom. Quite often the pain is located along the medial hindfoot and radiating into the medial longitudinal arch. This pain may be from frank arthrosis of affected joints or from the load of weight bearing stressing abnormally aligned bony and soft tissue structures such as the posterior tibial tendon, spring ligament or plantar fascia. Not infrequently, the patient complains of pain located laterally in the hindfoot, especially along the fibula. This pain is due to the calcaneus impinging on the tip of the fibula. This chronic impingement can even be severe enough to cause a secondary stress fracture of the fibula. Besides the location of the pain, another features of the pain is that it is invariably aggravated by bearing weight and eased by rest. Relief may be provided by analgesics but is more likely to occur with supportive shoes and orthoses. In my experience, patients often volunteer that their foot has deformed or acknowledge this if you specifically ask them. It is important to take a detailed history exploring what footwear modifications have been tried to alleviate pain and control deformity as non-operative management forms a large part of any foot ankle surgeon’s practice.
    There are other salient areas of the history that need to be explored. For example, in rheumatoid disease, it is important to know which other joints are effected by the disease including the upper limb as this has ramifications in the post-operative weight bearing regime. Equally, knowledge of the patient’s drug history is paramount as steroid use affects bone quality and may interfere with union. It is important to appropriately manage DMARDs in the peri-operative period. A full history of the patient’s social set-up at home is really important if you are considering significant hindfoot fusion surgery in any elderly patient but especially in the presence of systemic disease.
    Examination should include alignment of the whole of both lower limbs and should include gait and standing assessments. A full neuromuscular examination is mandatory.
    The soft tissue envelope needs to be inspected not only for previous surgical scars but also for the health and suppleness of the skin especially in the foot and ankle. The inspection should include the sole of the foot. Palpation often reveals tender areas, but it is the assessment of motion that is the key to decision making. As is always the case, in assessing deformity, it is important to determine flexibility and fixity of the foot. For me, this means starting with the ankle joint and assessing each joint in turn working proximally to distally looking for range of motion and reduction of the deformity. This is important because flexible planovalgus deformities can be managed with osteotomies and tendon transfers whereas fixed deformities require arthrodesis. Any tightness in the Achilles tendon does not affect the surgical approach as the tendon can be percutaneously released using a Hoke technique.

    IMAGING
    Plain radiographic imaging should be performed with the patient standing. The whole of the foot and ankle should be assessed when dealing with a planovalgus deformity. Usually this provides enough information especially in lesser deformities. However, if there is gross deformity or there is concern about the health of certain joint that cannot be determined from plain radiographic imaging, then a CT adds valuable information. In the following case, the deformity was so great that I felt I needed an even higher degree of imaging. In Sheffield, I am fortunate to have access to a 3D printing service which takes the CT images and can construct a 3D model of the foot to aid in my decision making (see operative technique).
    In the case I am going to take you through, the patient had a severe, fixed planovalgus deformity with limited ankle dorsiflexion and stiff soft tissues over the lateral hindfoot. I was certain that any lateral approach would stretch with deformity correction and the 3D model allowed me to plan a medial approach and give me options about whether I needed to resect some or all of the talus in order to achieve a stable, plantigrade foot.
    ALTERNATIVE OPERATIVE TREATMENT
    In a fixed planovalgus foot deformity in a patient with rheumatoid arthritis, my usual operative plan would be to perform a triple fusion. In most cases, the deformity is not gross and this can be achieved with both a medial and lateral approach. Having corrected the deformity, it may also allow future total ankle replacement if the ankle becomes symptomatic. In this case, I did not know how easy it would be to mobilise the hindfoot to make it lie back under the tibial plafond but I was sure that the body of the talus needed excision in order to attempt to do so. Therefore, my initial operative plan was to cut the neck of the talus, resect the body of the talus and see if this was enough to correct the foot position. I intended to perform a tibio-calcaneal fusion and fuse the neck of the talus too the anterior aspect of the tibia.
    NON-OPERATIVE MANAGEMENT
    In flexible planovalgus deformities, orthoses in the form of insoles to restore the medial longitudinal arch can, and should be tried. Occasionally specifically designed ankle braces can also be worn to correct the deformity. In these instances, physiotherapy can also add to the management programme by attempting to strengthen the tibialis posterior tendon.
    In fixed planovalgus deformities, orthoses accommodate for the deformity and try and prevent further joint motion. Frequently, this takes the form of an ankle-foot orthosis that is customised to the patient’s foot shape and allows either off-the-shelf or bespoke shoes to be worn over it.
    CONTRAINDICATIONS
    Be very aware of the red, swollen and unstable planovalgus foot with little pain. This presentation should raise the suspicion of a neuropathic foot undergoing a Charcot process. The management of this condition is very different.
    Open incisions to the ankle in the presence of diabetes, vascular disease or metabolic compromise from steroid treatment are relative contra-indications for surgical intervention. It may be safe practice to obtain a formal vascular assessment in cases of severe deformity planned for significant acute correction.
    Lastly, an operation such as this needs the patient to be fully involved with their post-operative management. Therefore, it is important to gauge their level of compliance and also to be frank about the consequences of the procedure on their day to day living. It is also important for them to understand the possible complications of the procedure. I warn them that there foot will never be “perfect” and that they will, at best, feel better than they were before the surgery. They need to know that they may still require bespoke foot wear because resecting the talus mean that the foot adopts an abnormal shape. I warn about infection, nerve injury, continued pain, deep vein thrombosis, pulmonary embolism and possible limb loss in such major reconstruction surgery.

    Setup

    The patient is positioned supine on the operating table and may benefit from a sandbag placed under the contralateral buttock so that the foot is positioned to allow comfortable medial access to the hindfoot (see operative photographs). In addition, the leg must be manoeuvrable to permit fluoroscopic evaluation. Fluoroscopy should be available with an image intensifier and a trained radiographer.
    Appropriate antibiotics are administered and a thigh tourniquet and exclusion drape are applied. The limb is prepared with Chlorhexidine from toes to tourniquet.

    Operation – 1

    Assess the patient’s deformity especially determining fixity versus flexibility
    It is clear to see from this picture viewing the foot from a medial to lateral aspect that the medial longitudinal arch has been lost even though the image is not taken with the patient standing. The head of the talus [A] is articulating with the ground and is very vertically orientated relative to the medial malleolus [B].

    The heel is clearly lying in a valgus position. As part of my pre-operative assessment, I am careful to inspect the soft tissue envelope and it is clear to see that if I were to incise the lateral skin, I could struggle to achieve skin closure after such a significant deformity has been corrected to neutral.

    This picture clearly shows where the head of the talus is contacting the ground with weight bearing [A]. The rest of the hindfoot has subluxated into valgus but is also externally rotated relative to the tibial tuberosity.

    Standing radiographs are mandatory for initial assessmentThis plain A-P standing radiograph of the ankle shows that the planovalgus deformity lies distal to the ankle joint. Even on this view, the declination angle of the talus can be appreciated because the whole of the head is completely visible. This is not usually the case in a normal foot and ankle.

    The standing lateral view shows the whole of the foot and best demonstrates the planus deformity of the foot.

    The D-P standing view of the foot shows that malalignment of the axis of the talus with the first ray.

    CT information is invaluable in surgical planning and may involve the use of 3D modellingIn the age of additive manufacturing, access to 3D printing is growing. Virtual and printed material can easily be generated that can aid pre-operative planning and even allow surgeons to practice osteotomies. The University of Sheffield offer this service in our practice. The 3D model is constructed from 1mm CT images and demonstrates the loss of the medial longitudinal arch of the foot. It is also accurate enough to determine that an ankylosis exists between the dorsal aspect of the head of the talus and the navicular [A]. I did not appreciate this from the CT images alone.
    The model also shows a very large os trigonum.

    This view of the model shows the posterior aspect of the foot. It is abundantly clear just how much valgus the hindfoot lies in with the talus fully internally rotated off the posterior facet of the subtalar joint.

    This is the equivalent of the A-P view of the ankle. Notice how externally rotated the whole foot is relative to the front of the tibia. Note that the tip of the fibula is almost at the level of the ankle joint. This suggests how much loss of hindfoot height has occurred with the deformity.

    This final view of the model demonstrates the well-established pseudarthrosis between the tip of the fibula and the calcaneus. Due to the poor lateral soft tissues, any lateral incision to dis-impact and mobilise the calcaneus should be avoided.
    The final advantage of this model is its use in the operating theatre. Although not sterilisable, this model can easily be brought to the surgeon to view by the circulating staff.

    The patient is positioned supine on the operating table with the leg in external rotation.Note that the patella [A] is pointing to the ceiling. Therefore, I decided not to use a sandbag to allow the foot to lie on the table because the external rotation of the foot as part of the deformity was sufficient enough to permit access through a medial approach.

    A posteromedial incision is planned according to the access required.With skin prepared, the planned incision allows access to the talo-navicular joint with the incision lying dorsal to the head of the talus [A]. The proximal limb of the incision lies posterior to the posterior border of the distal tibial shaft [B]. The apex of the incision [C] allows a flap to be raised that will allow identification of the neurovascular bundle and access inferior to the talus.
    Ordinarily, the medial approach to the subtalar joint does not require the proximal limb of this incision, but because I had planned to apply posterior fixation, the skin incision is adjusted accordingly.

    Exposure proceeds through the bed of tibialis posteriorSomewhat surprisingly the tendon of the tibialis posterior was intact.
    I did not expect this [A] due to the level of deformity but it can clearly be seen coursing under the head of the talus to insert on the navicular tubercle. Reflecting this tendon usually allows access to the middle facet of the subtalar joint.

    The flexor digitorum longus is identified behind the tibialis posteriorLying immediately posterior to the tendon of tibialis posterior was the tendon of flexor digitorum longus(A).

    With a K-wire inserted into the neck of the talus (and bent back on itself) acting as a retractor of the skin flap and the tibialis posterior and FDL tendons.The subluxated middle facet of the subtalar joint is identified at the tip of the McDonald’s tool. Note the flexor hallucis longus tendon [A] lying deep to the joint before it courses inferior to the sustentaculum tali.
    At this stage of the procedure, it is very apparent that any attempts to mobilise through the subtalar joint would be futile because of the fixity of the tissues. Any levering through the calcaneus could result in fracture or crushing of the posterior facet of the calcaneus.

    The tibialis posterior tendon is detached from its point of insertion and the head of the talus becomes visible [A] which assists access to reduce the deformity.Given my initial intention to preserve the head of the talus and fuse it to the anterior aspect of the tibia, I have placed Hohmann retractors superiorly and inferiorly around the neck of the talus.

    The first step in the talectomy is cutting the neck of the talus with a saw.

    The talar neck cut is completed with an osteotome.

    Using solid osteotomes, the body of the talus is resected piecemeal, initially leaving the head in situ.The fragments of the talus are retained for use as potential bone graft.
    Its soft-tissue attachments are sequentially and carefully dissected off the bone.

    The void left behind after resection of the body of the talus is clearly visible. Unfortunately, mobilisation of the midfoot made me realise that preserving the head and remaining neck of talus was likely to be futile. Therefore, the ankylosis between the head of the talus and the navicular was broken down as evidenced by the osteotomes sitting in the talo-navicular joint.

    The neurovascular bundle [A] is identified and protected with a sloop to allow further safe dissection posterior to the medial malleolusFollowing this resection of the os trigonum, and access to the Achilles tendon [B] (which is then sectioned) can be safely achieved. I sectioned the Achilles tendon to prevent it being one of the constraints to reduction of the foot.
    The neurovascular bundle should lie immediately medial to the tendon of flexor hallucis longs.

    The head of the talus is then resected with osteotomes. Again, the resected bone should be saved in case of requiring bone graft.

    Mobilising the foot to achieve reduction post talectomy may require skeletal distraction to access the lateral aspect of the foot through the medial approach.Having resected the head of the talus, the foot is still insufficiently mobile to reduce the calcaneus onto the tibial plafond. Therefore, a Hintermann’s retractor is applied from the navicular [A] to the medial malleolus [B] and this allows access to the pseudarthrosis between the tip of the fibula and the calcaneus [C].

    The lateral aspect of ankle and hindfoot is carefully mobilised by blunt release of dense soft tissue adhesions through the medial approach.Using chisels and osteotomes, the pseudarthrosis is mobilised and the articular cartilage is removed from the surface of the posterior facet of the calcaneus and the tibial plafond.

    Following mobilisation the foot should sit squarely beneath the tibia.I am finally content that the foot is reducible such that the posterior facet of the calcaneus can contact the tibial plafond with the foot plantigrade.

    Operation – 2

    Preparation of the bone graft from the talusIn the meantime, the resected talus is morcellised in a spinal bone mill.

    Selection of appropriate hardware for fixation. The plate contours may need to be altered to optimise plate postioning.The method of fixation I have chosen is a posterior hindfoot fusion plate by Wright. This plate is designed to be used for tibio-talo-calcaneal fusion. The distal extent of the plate [A] is designed to allow locking screw fixation into the calcaneus. The proximal extent of the plate [B] lies on the posterior aspect of the distal tibia. The other feature is the oval shape hole [C] in the plate that allows placement of a compression screw. Finally, the screw holes [D] in the plate which would ordinarily engage the talus when performing a tibio-talo-calcaneal fusion, can be used to engage the distal tibia. I intended these holes to engage the remaining head of talus, but given that I had resected the whole talus, the screw holes could engage the navicular.
    The plate required a little further contouring in order to cater for the lack of remaining talus. If the plate is left uncontoured, then the fusion mass will adopt the contour of the plate.
    Why choose this method of fixation versus a hindfoot intramedullary nail?
    A nail has the advantage of providing fixation close to the mechanical axis of the hindfoot and ankle. Unfortunately, in soft bone such as in rheumatoid disease, it does not provide sufficiently robust fixation in the calcaneus. Mechanical studies comparing the fixation techniques in tibiocalcaneal fusion suggest that the nail provides superior hold than laterally-applied blade plates. There are no such studies comparing nail fixation with locking plates. Studies do show that posterior ankle fusion plating is exceedingly strong as it is close to the mechanical axis. Hence, the rationale for a posteriorly applied locking plate.

    This shows the locking screw guide in the distal most screw holes.

    Distal fixation of the plate initially into the calcaneus and imaging to check positionThe plate is slid into position on the posterior aspect of the tibia. Using the locking guides, both locking screws are applied into the calcaneus and the position checked with fluoroscopy in both planes. By using locking screws, this gains control of the distal segment of the arthrodesis and solid hold in soft bone.
    Note that I have decorticated the anterior aspect of the distal tibia so that it can fuse with the navicular [A].

    Graft is then applied into the tibiocalcaneal spaceThe graft is then applied into the tibiocalcaneal space.

    Achieving compression across the tibio-calcaneal interface with the plate and proximal screws, followed by a fluoroscopic checkHaving locked control of the calcaneus, use of the oval hole in the plate allows the plate to seat itself onto the posterior aspect of the tibia and allows compression across the tibiocalcaneal surface. Although the screw is long, it can be removed once the other adjacent locking screws are applied.
    It is crucial that the foot is maintained in a plantigrade position. Any compromise of this needs further adjustments to the joint preparation or the attitude of the fixation before completion of the next surgical steps.

    Application of locking screws to the constructGiven the patient is in a supine position, accessing the posterior screw holes is not easy and necessitates assistance and careful observation of the neurovascular bundle.
    Since performing this surgery, I have pondered whether I could have performed all of it with the patient lying prone on the operating table. The compromise would be that the reduction part of the procedure would have been much harder but the fixation would have been easier. The only other option would have been to move the patient into a lateral or prone position midway through the case.
    Note that it is the detached tibialis posterior tendon that is dangling next to the drill sleeve. This was retained in case it would have had any use as a tenodesis, but was resected before closure.

    This lateral image shows the locking screws applied in the proximal limb of the plate having removed the screw from the oval hole. The long screw is engaging the navicular and is locked in the plate.

    Application of independent fixation across the tibio-navicular interfaceIn order to provide some additional fixation and indeed some compression across the interface between the navicular and the anterior distal tibia, I decided to add in a staple for compression. In some of the literature, it is documented that this step of the procedure may not be necessary as non-union is uncommon. However, my belief is that this observation is true when performing a talectomy and tibiocalcaneal fusion in children.
    For this, I use the Arthrex nitinol compression staple system. This allows a range of hindfoot staples with interaxis spans of 10-20mm and tyne lengths of 10-20mm. The guide shown allows you to plot the interaxis span.

    The tyne of the staple is cannulated. Thus, the two guide wires are inserted using the guide shown in the previous slide [A], one in the navicular and the other in the tibia. Here I have selected a 20 x 20mm staple [B] and it is shown here with the staple being held in the delivery handle/tamp [C]. In hard bone, these guide wires can be overdrilled to the correct depth with cannulated drill bits. In this case, the rheumatoid bone is very soft and there was no need to pre-drill.

    The staple is then tamped into position. The span contains a diamond shaped aperture [A] that accepts a tool that, when opened, deforms the aperture to apply compression. This was performed with caution in this case in order to prevent the staple from cutting out from the soft bone.

    Final A-P fluoroscopic view of the tibiocalcaneal fusion.

    Final lateral fluoroscopic view of the tibiocalcaneal fusion.

    Closure in layersClosure of the wound proceed in layers with 2/0 vicryl and 3/0 monocryl to the skin. Note the plantigrade position of the foot.

    Final views of the sole of the foot. Note the correction of the external rotation of the foot relative to the patella. The medial fullness represents the medial malleolus lying closer to the sole of the foot.
    The wounds are dressed with Jelonet, dressing gauzes and orthopaedic wool before application of temporary plaster of Paris slabs secured with crepe bandaging.

    Post Operative

    The patient is placed in a below the knee back slab for the first two weeks after surgery. This is purely to rest the soft tissues after such major surgery. At two weeks, the wounds are inspected and re-dressed and a complete, lightweight below-the-knee cast is applied for a further four weeks. Weight bearing is not permitted for the first six weeks after surgery. Given the patient is elderly and compromised by rheumatoid arthritis, the best way of protecting the surgical site is to ask the patient to mobilise with a Zimmer frame that has arm gutters. In my practice, rivaroxaban is prescribed for this duration to prevent thrombo-embolic events even in the absence of studies to support its use. With the extent of surgery, any leaky wounds may necessitate ceasing thromboprophylaxis.
    At six weeks, the patient can commence weight bearing in a walking cast. An off-the-shelf walker boot may not be well tolerated as it is designed to conform to a foot and ankle with a talus present!
    At twelve weeks, the foot is assessed radiographically with standing views in three planes before abandoning further immobilisation.
    Given that this is a fusion procedure, there is no indication for physiotherapy other than to aid with safety using crutches and regaining confidence in bearing weight using the walker boot.

    Recommended Reading

    Tibiocalcaneal arthrodesis for the management of severe ankle and hindfoot deformities. MS Myerson, RG Alvarez, PWC Lam. Foot Ankle Int 2000; 21(8): 643-650.
    This is the largest series of cases describing this surgical technique. It describes a heterogenous group of pathologies that underwent the procedure, including for pes planovalgus in inflammatory arthropathies. In this era, laterally-applied blade plates were used for fixation. Documented complications included stress fracturing at the proximal tip of the plate and non-union.
    Tibiocalcaneal arthrodesis with posterior blade plate in diabetic neuroarthropathy. M Cinar, A Derincek, S Akpinar. Foot Ankle Int 2010; 31(6): 511-516.
    This small case series demonstrated a 75% union rate with a posteriorly applied blade plate in the poor quality bone and soft tissues associated with diabetic neuroarthropathy.
    Talectomy and tibiocalcaneal arthrodesis with intramedullary nail fixation for treatment of equinus deformity in adults. S Gursu, H Bahar, Y Camurcu et al. Foot Ankle Int 2015; 36(1); 46-50.
    This contemporary paper has excellent fusion rates in the classic causes of fixed equinovarus deformities. They note no post-operative complications by not formally attempting to fuse the tibio-navicular interface.

    Reference

    • orthoracle.com

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