DEFINITION

A surgical procedure in which the ankle and the subtalar joint are arthrodesed simultaneously

 

 

ANATOMY

 

The tibiotalar joint is bound by the medial malleolus, the fibula (lateral malleolus), anterior retinaculum and tendinous structures with the neurovascular bundle, and posteriorly by the flexor hallucis longus (FHL) and Achilles tendon.

 

The posterior tibial nerve lies immediately adjacent to the FHL tendon on the medial side.

 

PATHOGENESIS

 

Any trauma or inflammatory process which affect the ankle and subtalar joint simultaneously can cause pain in both of these joints. So too can the ankle be irreparably damage with a failed total ankle with so much fibrosis in the subtalar joint that it is not feasible to preserve it.

 

Because the rod stabiles both the ankle and subtalar joint, it may be used in paralytic conditions and when the talus is avascular and both the ankle and subtalar joints have been affected.

 

NATURAL HISTORY

 

The natural history is for the pain to increase because of increasing damage and loss of motion in these two joints. The prognosis is poor without surgery.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

The patient complains of generalized pain across the anterior aspect of the ankle (ankle joint) and in the sinus tarsi (subtalar joint).

 

They have a limited range of motion in these joints and they are often painful on attempted manipulation and deep palpation.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Diagnostic imaging consists of standard standing anteroposterior (AP), lateral, and mortise views of the ankle.

 

Additional standing full foot films are necessary, including a calcaneal view to ensure that the patient does indeed have a problem in the ankle and subtalar joints.

 

Frequently, a computed tomography (CT) scan of the ankle is necessary to confirm this fact.

DIFFERENTIAL DIAGNOSIS

Inflammatory arthropathy (rheumatoid arthritis, gout, hemosiderosis, etc.), trauma, failed ankle replacement, avascular necrosis of the talus and/or tibia, spastic paralysis, Charcot arthropathy, failed

 

ankle fusion with subtalar arthritis, and resectable tumor with bone loss

 

 

NONOPERATIVE MANAGEMENT

 

Nonoperative treatment included bracing, orthotics, nonsteroidal anti-inflammatory drugs (NSAIDs), and injections of steroid and narcotic medication.

 

SURGICAL MANAGEMENT

 

The indications for surgery are coexisting painful inflammation in the ankle and subtalar joints simultaneously. This procedure is indicated when it is believed that neither ankle fusion nor subtalar fusion alone would suffice in producing a relatively painless functional limb.

 

It must be discussed with the patient that for whatever reason, they are not a good candidate for ankle replacement and subtalar fusion to deal with this problem (FIG 1).

 

Preoperative physical examination is mandatory to ensure that the approach is appropriate when considering previous incisions, trauma, free flaps, wound healing problems, and deformity.

 

Positioning

 

Although a tibiotalocalcaneal (TTC) arthrodesis may be accomplished in a supine and even lateral position, because insertion of the calcaneal screws is best done posterior to anterior, the prone position of the patient is desired. This position allows the leg to be shifted off the table for easy AP and by rotating the leg, a lateral xray with fluoroscopy. The tibial screws are inserted with the knee flexed 90 degrees.

 

Be careful to avoid the side paddle on the table near the thigh because this will prevent the leg from being shifted off the table.

 

Approach

 

Approach can be anterior, lateral, and posterior.

 

 

The disadvantage of the anterior approach is the need to make a separate incision for preparation of the subtalar joint.

 

The lateral approach is discouraged because of the need to resect the fibula, a technique that is believed to be outmoded and contributes to some subsequent valgus deformities if the ankle or subtalar joint do not heal.1

 

The posterior approach allows preparation of the ankle and subtalar joint simultaneously and has an angiosomic pattern that is ideal for healing.

 

 

55

 

 

 

FIG 1 • AP (A), lateral (B), mortise (C), and Saltzman (D) radiographs of 65-year-old man weighing 270 pounds, who had undergone attempted fusion of right ankle after trauma 10 years earlier. He presented with a nonunion of his ankle joint and severe subtalar arthrosis.

 

TECHNIQUES

• Exposure

Superficial Incision

The incision can be made just lateral to the Achilles but I prefer a midline, longitudinal Achilles tendon approach4 (TECH FIG 1).

It begins 8 cm above the posterosuperior aspect of the calcaneus and extends to the inferior surface of the calcaneus.

The tendon is split down the middle and the attachment on the calcaneus is relieved both medially and laterally. Remember, this is where the posterior to anterior screws are inserted anyway, and this

 

increased release facilitates exposure of the ankle and subtalar joint simultaneously.

 

In extreme cases of equinus, one can do a Z-lengthening of the Achilles or completely remove the attachment onto the calcaneus.

Deep Incision

 

Once through the Achilles tendon, the deep retinaculum is cut and the flexor hallucis muscle bellies are visualized.

 

The muscle belly is followed distally and the FHL tendon is dissected off the calcaneus for mobility. The muscle belly is free and retracted medially. Use of the Henley retractor can assist with the visualization.

Ankle Exposure and Subtalar Exposure

 

Now, the posteroinferior tibial lip is exposed and removed to facilitate entry into the ankle joint. Using a blunt periosteal elevator, the ankle joint and subtalar joint are free from any adhesions. Exposed cartilage is removed from both joint. It helps to use

 

56

a lamina spreader, both medium and extra large to be able to open these joints. A distraction pin separator is usually necessary.

 

 

 

 

TECH FIG 1 • After an anterior exposure to remove his previous hardware, patient is opened straight posteriorly through the Achilles tendon to expose his ankle and subtalar joint.

 

 

If there is a total ankle in place, the polyethylene is removed first. To remove the talar component first and then the tibial component, a small reciprocating and oscillating saw is used to cut free any bony attachment so as to preserve maximum bone continuity.

 

If there is an intramedullary (IM) tibial component, it may be necessary to window the posterior tibial for

exposure. This way, the reciprocating saw can maneuver around the stem and free up most of the ingrowth bone.

 

For the INBONE prosthesis, the base plate can be removed with an impactor and the wrench can be inserted around the last stem piece and then impaction begins on the wrench. A large bone hook placed with in the INBONE stem can help to counteract the posterior impaction force to keep the tibia from breaking at the level of the ankle.

• Débriding the Ankle and Subtalar Joint

   

  Removal of the cartilage and or soft tissue débride can be accomplished with curettes, rongeurs, sharp dissection with a knife, a burr, a saw to cut the talar surface slightly, or even a small acetabular reamer

  (38 mm) to speed up the process.2

   

  The tool is taken in the wound, protecting the posterior tibial nerve and can be used to remove soft tissue and leave a concavity in the tibia into which a femoral head can be inserted if necessary.

   

  If there is complete avascular necrosis of the talus, I like to remove the posterior half of the talus and replace that with a femoral head.

   

  If there is eburnated bone present, drilling the bone extensively with a 4.5-mm drill will break down the bone to allow vascular ingress more easily (TECH FIG 2).

   

   

   

  TECH FIG 2 • Once any remaining cartilage and/or fibrous tissue is removed, the surfaces of the ankle and subtalar joints should be drilled with a 4.5-mm drill bit to break up the subchondral bone.

• Bone Grafting

   

  Once the joint is cleaned and the surface prepared, bone graft is added. I routinely use bone morphogenetic protein (BMP) sheets laid anteriorly, medially, and laterally.3 Onto this is laid up to 40 mL

   

  of thawed frozen cancellous bone. This is followed by a trimmed femoral head to fit the space. I usually trim the sides and the base of the head to make it fit and then impact it into position.

   

  This may also be done after preparing the leg for the rod because the head will want to spit out posteriorly as you prepare leg for the rod.

   

  If it is done now, you can put some posterior Steinmann pins into the head and surrounding bone to get it to stay in place.

• Preparation of the Leg for the Nail

 

Depending on the manufacture's rod you are using, preparation of the leg for the nail may vary. For purposes of detailing the surgical procedure here, I will use the A3 nail.

 

Place a guide pin into the calcaneal fat pad using the pin placement guide (TECH FIG 3A-D) or place it free hand parallel to the calcaneal cuboid (CC) joint, about 20 mm posterior to the joint and in the middle of the calcaneal fat pad.

 

If you aim just slightly laterally and anteriorly, when the rod is placed, you will force the foot into dorsiflexion and valgus and help void plantarflexion and varus.

 

Note that in TECH FIG 3C, you see an osteotomy in the fibula. This was done to reduce the patient into a hindfoot valgus position. Failure to do so would have caused the patient to walk on the side of his foot. However, it has never been necessary to remove the fibula which adds to the support of the final construct.

 

The angulated drill sleeve is used to find the place laterally and posteriorly to place the incision for the reamers.

 

Once the guide pin is in place, ream the guide pin starting with fixed reamers to the tibiotalar joint (TECH FIG 4A-G) and then insert a longer ball-tipped guide rod up the tibia and ream ½ mm larger than the intended rod for the shorter rod 150 to 180 mm and 1 mm larger for the larger rods 210 mm (TECH FIG 4H-K).

 

Add a femoral head allograft and additional cancellous bone, insert the guide pin again, check its position with the fluoroscope (TECH FIG 5), and then reream a hole into the bone graft to accommodate the rod.

 

57

 

 

 

TECH FIG 3 • A. A pin placement guide is now inserted into the ankle joint with its distal tip just anterior and lateral to talar dome center. B. The guide pin is now placed through the guide until it reaches the tibial plafond. It is then sitting in the calcaneus and talus. C,D. Checking the guide pin placement on AP and lateral x-rays, respectively. Note how the guide pin is situated anterolateral to the talar dome. Then, when the foot is brought into dorsiflexion and valgus, the rod will go up the tibia and place the foot in the popper position.

 

 

 

TECH FIG 4 • A. Using the central pin already in place, an additional guide is placed over that pin to provide direction for the posterolateral bend in the A3 nail. B. The guide for the posterolateral pin is set in place. C. The posterolateral guide pin is being placed. D. Axial photo showing how both pins are now sitting in the ankle. The C-arm is brought over the top of the leg to ensure the two pins are in the correct position.

E. The guide pin is directed anteriorly so that when the boot is dorsiflexed, the rod will go into the tibia. The first guide pin is then removed and the posterolateral guide pin is reamed to accommodate the rod. (continued)

 

 

58

 

 

 

TECH FIG 4 • (continued) F,G. AP and lateral x-rays, respectively, showing the extent of the first reaming over the guide rod. H. The reamer has now been removed and a ball-tipped guide is being inserted into the tibia to lie in the calcaneus, talus, and tibia. I,J. AP and lateral x-rays showing the placement of the ball-tipped guide in the ankle and leg. K. Over this rod sequentially ream up to ½ to 1 mm greater than the diameter of the rod intended for shorter or longer rods, respectively.

 

 

 

TECH FIG 5 • A. Cut a femoral head to fill any major defect in the ankle to preserve leg length. B. Add plenty of thawed frozen allograft to fill in any defect. I usually add ¼ g of vancomycin powder per 20 mL bone graft. C. Add enough bone graft to fill the defect while leaving room for the femoral head. D. Impact the femoral head so it stays in place, and add more bone graft to fill in any remaining defects and impact it into position. E. Replace the guide pin through the femoral head and check its position using the C-arm. Then, while holding the femoral head in position, ream over the guide rod to create a hole in the femoral head for the nail.

 

 

59

• Rod Insertion

   

   

  Assemble the rod according to the manufacture's specifications with the inserter. Remove the ball-tipped guide and push the rod into position.

   

  Check the lateral x-ray to ensure that the rod is deep enough but not too deep.

   

   

   

  TECH FIG 6 • A. Now pull out the reamer and the guide pin out and insert the TTC A3 nail. B. The nail is in the hindfoot and leg, coming in from the posterior lateral side of the calcaneus in order to capture as much of the calcaneus as possible. C. The position of the nail is now checked on fluoroscopy to ensure the nail is inserted to its proper depth.

   

   

  Mark the holder so that you can see if this position is changed during insertion of the screws (TECH FIG 6).

   

  If the foot is not in proper position, remove the rod and reream the calcaneus and talus to 13.5 mm to give yourself some leeway to push the rod eccentrically into the hole and get more dorsiflexion or valgus.

• Interlocking Screws

   

  Using the holder, rotate the guide into the C position.

   

  With the rod inserted to the correct depth, drill the calcaneal screw holes, usually in the compression position. Leave a drill in place and check the length of the intended screw on fluoroscopy.

   

   

  Insert the second drill; again, verify its position to ensure it has not gone through the CC joint. Insert the two calcaneal screws (TECH FIG 7A-C).

   

  Rotate the holder to the T position and insert the talar screw in the same manner (TECH FIG 7D,E).

   

   

   

  TECH FIG 7 • A. The calcaneus, talar, and tibial screw guide is now locked in place. B. Drill a hole for the calcaneal screw first and insert that screw. C. Check its position as it goes into the calcaneus. Now, switch the guide to T for the talar screw. (continued)

   

  Rotate the rod to the M position. Make sure the holder is tight and drill one hole through the tibia from medial to lateral, measure its length and insert the screw, and again in the compression mode if you plan on trying to close down the space at the tibiotalar and subtalar joints. Add the second screw (TECH FIG 7F).

   

  Check to ensure correct positioning of the rod and add some compression to the construct (TECH FIG 7G,H).

   

  Let the tourniquet down to ensure return of vascularity to the leg (TECH FIG 7I,J).

   

   

  60

   

   

   

  TECH FIG 7 • (continued) D. Drill the talar screw hole and insert the talar screw. E. Check its position on fluoroscopy. F. Move the guide to the M position, drill one tibial hole, and insert the tibial screw, checking it fluoroscopically. G,H. Final lateral and AP x-rays showing placement of the A3 nail. I. The tourniquet has been let down while the other tibial screw hole is prepared. J. Use screwdriver to exert final compression within the rod.

• Additional Bone Grafting

   

  Add more thawed cancellous chips over the femoral head and pack it into position, being careful not to compress the posterior tibial nerve.

   

   

  Prepare the top of the calcaneus to allow bone ingrowth if not already done. Place BMP sheets posteriorly.

• Closure

   

  Use a running 2-0 absorbable stitch in the Achilles tendon over a drain. Using a drain obviates having the patients and or the nurses to tell you the patient is bleeding out of their cast.

   

  Add some 3-0 absorbable stitches to the subcutaneous tissue.

   

  Close the skin with 3-0 nylon in a vertical mattress fashion.

• Casting

   

  Apply two stacks of 4 × 8 gauze to the anterior ankle transversely, with the crack between them at the level of the ankle. Add two more 4 × 8 gauze packs on the lateral and posterior sides.

   

  Apply soft roll so that there are five sheets proximally and distally.

   

  Apply three 4-inch roles of fiberglass, being careful not to overlap the top of the cast padding.

   

   

  61

• Case Example (Courtesy of Mark E. Easley, MD)

Background and Imaging

 

 

A 65-year-old man with chronic right ankle/hindfoot pain Remote history of severe ankle sprain

 

Failed course of bracing

 

Physical examination

 

 

Hindfoot with neutral position Ankle and hindfoot stiffness

 

 

Pain with ankle and hindfoot stress/motion Radiographs

 

Ankle with early arthritis and irregular lateral talar dome (TECH FIG 8A)

 

 

Hindfoot arthritis and loss of heel height and anterior ankle impingement (TECH FIG 8B) Hindfoot alignment view suggest neutral heel alignment (TECH FIG 8C)

 

CT

 

 

Coronal plane (TECH FIG 8D) Advanced subtalar joint arthritis

 

Chronic anterolateral talar body nonunion

 

 

Subfibular impingement Sagittal plane (TECH FIG 8E)

 

Advanced subtalar joint arthritis

 

 

Undersurface of talar body erosion/fragmentation Anterior ankle impingement suggested

 

 

 

TECH FIG 8 • A 65-year-old man with right ankle and hindfoot pain. A. Weight-bearing AP ankle view suggests irregular lateral talar dome. B. Severe loss of heel height and subtalar arthritis. C. Neutral heel alignment based on hindfoot alignment view. D. Coronal CT suggests severe subtalar arthritis and nonunion of anterolateral talar dome. E. Sagittal CT with severe subtalar arthritis, anterior ankle impingement, and loss of heel height.

Intramedullary Tibiotalocalcaneal Arthrodesis

 

Prone position

 

 

Posterior approach (TECH FIG 9A) Achilles tendon Z-lengthening

 

 

Protect posteromedial neurovascular bundle. Joint distraction

 

 

Joint preparation Joint reduction

 

Improve joint access for joint preparation for arthrodesis.

 

Joint preparation

 

 

Débridement of unhealthy/avascular bone Preparation of residual ankle and subtalar joints

 

Bone grafting

 

Structural allograft: calcar of a femoral head allograft to compensate for loss of heel height (TECH FIG 9B)

 

Cancellous bone (TECH FIG 9C,D): fill voids and augment arthrodesis

 

 

Provisional fixation and confirm satisfactory alignment and bony apposition Clinical evaluation

 

Neutral dorsiflexion/plantarflexion (TECH FIG 9E)

 

 

Second metatarsal aligned with the tibial crest (TECH FIG 9F) Heel valgus: Avoid heel varus.

 

Confirm optimal position fluoroscopically.

 

 

62

 

 

 

 

TECH FIG 9 • A. Posterior approach with Z-lengthening of the Achilles tendon. B. Femoral head allograft. Using the neck portion of the structural graft to reestablish heel height and rebuild débrided avascular portion of talar dome. C. Augmenting structural graft with cancellous graft. D. Impacting the graft fully. E,F. Optimal alignment with provisional fixation. E. Neutral sagittal plane position. F. Neutral rotation. Note second metatarsal aligned with tibial crest. Also assess heel valgus.

Definitive Fixation: Intramedullary Nail

 

 

Properly place and align guide pin From plantar foot

 

Confirm proper position of pin on AP and lateral intraoperative fluoroscopy.

 

Ream over guide pin (TECH FIG 10A)

 

 

Retrograde from calcaneus through talus and structural allograft into center of distal tibia Determine optimal IM nail diameter and length.

 

Place IM nail with guide/insertion device (TECH FIG 10B).

 

Maintain proper ankle and foot alignment.

 

Fluoroscopically confirm proper IM nail position, including appropriate depth to which the nail is inserted.

 

 

Insert distal calcaneal interlocking screws, placed from posterior to anterior. Place provisional dynamic proximal fixation.

 

 

Through the system, apply compression at the arthrodesis sites (TECH FIG 10C). Insert the proximal interlocking screws (TECH FIG 10D).

 

Remove the insertion device.

Supplemental Fixation (at Surgeon's Discretion)

 

 

Screw fixation from medial distal tibia into medial talar body (TECH FIG 11A,B) Posterior plate (TECH FIG 11C)

 

Final intraoperative fluoroscopic views

 

In this case, note 4 to 6 cm of Achilles lengthening suggesting that the heel height improved (TECH FIG 11D).

Postoperative Care

 

Protected weight bearing for 8 weeks in short-leg cast (SLC)

 

After 8 weeks, gradually advance weight bearing in SLC or cam boot.

 

At 12 weeks, gradually transition to stiffer-soled shoe with slight rocker bottom and ankle-foot orthosis (AFO) with a fixed ankle

 

 

Gradual transition to full weight bearing in stiffer-soled shoe with rocker bottom modification Consider CT scan at 12 to 16 weeks to assess incorporation of structural graft (TECH FIG 12).

 

63

 

 

 

TECH FIG 10 • A. Reaming from the calcaneus through talar body and structural graft into the tibia over guidewire. Note supplemental provisional fixation from calcaneus into posterior tibia to maintain reduction during reaming. Fluoroscopic evaluation to ensure optimal reaming. B. IM nail inserted with insertion device. Optimal rotation for the insertion device and IM nail is maintained. C. Once IM nail properly seated and provisional support pin placed proximally, compression is applied. D. Proximal interlocking screws inserted. Note compression through provisional proximal fixation.

 

 

 

TECH FIG 11 • A. Weight-bearing AP ankle view. B. Mortise view. Note supplemental medial screw. C. Lateral view. Note supplemental posterior plate. D. Considerable heel height restoration suggested with Achilles being lengthened approximately 4 to 5 cm.

 

TECH FIG 12 • CT scan coronal view at 12 weeks suggests satisfactory early bridging trabeculation at arthrodesis sites.

 

 

64

PEARLS AND PITFALLS
	Position the rod centrally in the calcaneus ▪ If the rod leaves the leg into too much 20 mm from the joint and aim the guide pin plantarflexion or varus, the patient will not be happy. slightly 3-4 mm medially and anteriorly to Remove the rod and over ream the calcaneus and get the nail in the correct position. talus to shift the foot into more dorsiflexion and valgus.     Avoid compression of the posterior tibial ▪ If the patient has dysesthesias in the foot nerve. postoperatively, obtain an electromyography (EMG) and consider a tarsal tunnel release.     Do not leave the rod sticking out the ▪ Use fluoroscopy and constantly check to make plantar calcaneal cortex. sure the rod end is at the level of the plantar calcaneus.     Ensure the holder is fixed tightly to the rod. ▪ Leaving the holder even a little loose can result in the screw holes missing the rod.

 

 

 

	Insert the calcaneal screws deep enough ▪ Visualize the end of the screw to make sure it is (5 mm past the cortex) so they do not deep enough. bother the patient postoperatively.     If the patient has a severe deformity and is ▪ Removing of the fibula was a technique done in being blocked from correction by the the past to avoid the fibula hitting the counter of the fibula, simply cut the fibula posteriorly so shoes. Now that we add femoral head to the that it can angulate the way you want it to. construct, this is no longer a problem.

 

 

POSTOPERATIVE CARE

 

The patients are usually done with an overnight stay only. They are discharged the next morning with instructions to keep their “toes above their nose” 23 hours per day, get up once an hour during the day, and do not put body weight on their leg.

 

They are seen for the first time at 3 weeks postoperatively, the cast removed, stitches removed, and recasted for another 3 weeks with the same instruction.

 

At 6 weeks, a standing x-ray is obtained and patients are allowed to begin weight bearing in a removable boot.

 

They wear the boot for 4 weeks when up walking and then remove it and advance to shoes and compression hose if needed.

 

Full healing take about 6 months with continued remodeling of the bone graft for 2 years (FIG 2).

OUTCOMES

In a retrospective case series of 32 patients, all of whom required a femoral head bulk allograft, there

were only 50 fusions, albeit a 71% functional salvage rate and a 19% amputation rate.6 All 9 diabetic in this case series developed a nonunion.

 

FIG 2 • Five-month follow-up of the patient in TECH FIGS 8, 9, 10, 11. A. Anterior view. B. Lateral perspective. C. Posterior view.

In another series of 30 cases with less severe diagnoses, the patients experienced an 86% and 74%

 

 

fusion rate of the tibiotalar and subtalar joints, respectively.5

Finally, in Multicenter European Study, the union rate of TTC arthrodesis was 84%, with all 13 of the patients who were working prior to surgery returning to work after surgery.7

Newer articles describing nails which have a more anatomic shape are being studied and the results will soon be available.8

 

 

COMPLICATIONS

Nonunion from inadequate preparation of the bone, not enough bone graft, poor stability

Infection. I use double antibiotics on these big cases, that is, Ancef × 24 hours and one dose gentamicin preoperatively. I use antibiotic irrigation 1 g Ancef in 1 L normal saline (NS) and vancomycin powder 1 g per 80 mL cancellous bone.

Improper positioning. See aforementioned for pin insertion in slight 3 to 4 mm anterior and lateral position to get foot dorsiflexed and in valgus.

Posterior tibial nerve irritation. Always keep in mind the closeness of the posterior tibial nerve by knowing it is just medial to the FHL.

 

 

 

65

REFERENCES

1. Berkowitz MJ, Clare MP, Walling AK, et al. Salvage of failed total ankle arthroplasty with fusion using structural allograft and internal fixation. Foot Ankle Int 2011;32(5):S493-S502.

    

2. Cuttica DJ, Hyer CF. Femoral head allograft for tibiotalocalcaneal fusion using a cup and cone reamer technique. J Foot Ankle Surg 2011;50(1):126-129.

    

3. DeVries JG, Nguyen M, Berlet GC, et al. The effect of recombinant bone morphogenetic protein-2 in revision tibiotalocalcaneal arthrodesis: utilization of the Retrograde Arthrodesis Intramedullary Nail database. J Foot Ankle Surg 2012;51(4):426-432.

    

4. Fetter NL, DeOrio JK. Posterior approach with fibular preservation for tibiotalocalcaneal arthrodesis with an intramedullary nail. Foot Ankle Int 2012;33(9):746-749.

    

5. Gross JB, Belleville R, Nespola A, et al. Influencing factors of functional result and bone union in tibiotalocalcaneal arthrodesis with intramedullary locking nail: a retrospective series of 30 cases. Eur J Orthop Surg Traumatol 2014;24:627-633.

    

6. Jeng CL, Campbell JT, Tang EY, et al. Tibiotalocalcaneal arthrodesis with bulk femoral head allograft for salvage of large defects in the ankle. Foot Ankle Int 2013;34:1256-1266.

    

7. Rammelt S, Pyrc J, Agren PH, et al. Tibiotalocalcaneal fusion using the hindfoot arthrodesis nail: a multicenter study. Foot Ankle Int 2013;34(9):1245-1255.

8. Richter M, Evers J, Waehnert D, et al. Biomechanical comparison of stability of tibiotalocalcaneal arthrodesis with two different intramedullary retrograde nails. Foot Ankle Surg 2014;20:14-19.