Hallux Interphalangeal Joint Arthrodesis
1. Indications
a. As a component part of a Jones transfer of the extensor hallucis longus (EHL) to the 1st MT neck (see Chapter 7) for claw deformity of the hallux in a skeletally mature adolescent, if tenodesis of the distal stump of the EHL to the EHB is unsuccessful or not possible
i. Usually performed during the second stage of a two-stage reconstruction for cavovarus deformity with clawing of the hallux (see Chapter 5)
b. Degenerative arthritis of the hallux IP joint.
2. Technique (Figure 8-37)
a. If this is an isolated procedure, perform a percutaneous tenotomy of the FHL (see Chapter 7)
b. If this procedure is being performed in conjunction with other procedures during the second-stage reconstruction of a cavovarus foot, the FHL was already released in stage 1.
c. Make a longitudinal incision dorsal to the EHL starting just distal to the hallux interphalangeal joint (avoiding injury to the germinal cells of the toe nail) and extending proximally to the base of the proximal phalanx or, if performed in conjunction with a Jones transfer, to the base of the 1st MT.
i. see Jones transfer of EHL to 1st MT neck, Technique d–g, Chapter 7.
d. Make a Z-lengthening type cut in the EHL for later tendon plication.
e. Release the interphalangeal joint capsule transversely on the dorsal, medial, and lateral surfaces, and elevate the volar capsule off the adjacent ends of the phalanges with a Freer elevator
f. Using a microsagittal saw, remove the condyles of the proximal phalanx by cutting perpendicular to the dorsal cortex of the bone and to the longitudinal axis of the phalanx.
g. Sharply elevate the capsule from the proximal end of the distal phalanx to expose the articular surface
h. Using a microsagittal saw, remove the articular cartilage surface of the distal phalanx perpendicular to the dorsal cortex of the bone
i. Drill the guide pin for a 4.0- to 4.5-mm cannulated screw antegrade from the center of the cut surface of the distal phalanx out the end of the toe
j. Cut the proximal end of the pin obliquely to make a point
k. Bring the cut surfaces of the bones into apposition and drill the guide pin retrograde into the proximal phalanx
l. Insert a partially threaded 4.0- to 4.5-mm cannulated screw and countersink the head of the screw into the tuft of the distal phalanx
m. Confirm alignment of the bones and position of the screw with mini-fluoroscopy
Figure 8-37. A. Intraoperative AP x-ray of a hallux interphalangeal joint arthrodesis with a cannulated screw and guide wire in place. There is straight axial alignment of the phalanges. All of the screw threads are in the proximal phalanx which helps with compression at the fusion site. B. Intraoperative lateral x-ray shows the ideal position of the phalanges and the screw. The screw head is countersunk in the tuft of the distal phalanx to prevent a painful prominence at the tip of the toe.
n. With the ankle and the hallux MTP joints at neutral dorsiflexion, plicate the overlapping ends of the EHL side-to-side with figure-of-8 2-0 absorbable sutures.
i. When performed as part of a Jones transfer, tenodese the distal EHL stump to the EHB (see Jones transfer, Chapter 7)
o. Approximate the skin edges with interrupted subcutaneous 3-0 absorbable sutures and a running subcuticular 4-0 absorbable suture
p. Complete any other procedures being performed concurrently
3. Pitfalls
a. Difficulty in finding the proper axial alignment for the screw. Inserting the guide pin antegrade from the cut surface of the distal phalanx and then retrograde into the proximal phalanx diminishes this challenge
4. Complications
a. Injury to the neurovascular bundles
i. Avoid by staying central with the dissection and maintaining extracapsular retractors
b. Injury to the germinal cells of the nail plate
i. Avoid by limiting distal dissection to only that required to see the proximal end of the distal phalanx
c. Pain distal to the screw head resulting in the need to remove it
i. Avoid by countersinking the screw head
Hallux Metatarsophalangeal Joint Arthrodesis
1. Indications
a. Hallux valgus in a child with cerebral palsy
Figure 8-38. A. Severe, painful hallux valgus (without metatarsus primus varus or flatfoot) in a teenage girl with cerebral palsy, Gross Motor Function Classification System (GMFCS) level II. B. Standing AP x-ray of her foot. C. Standing AP photograph of her foot taken 6 weeks postoperatively. D. Standing AP x-ray taken 6 months postoperatively. E. Standing lateral photograph of her foot at 6 weeks post-op. F. Standing lateral x-ray at 6 months.
2. Technique (Figure 8-38)
a. Correct other foot deformities, which usually include valgus deformity of the hindfoot (see Calcaneal Lengthening Osteotomy, Chapter 8), gastrocnemius contracture (see Gastrocnemius Recession, Chapter 7), and metatarsus primus varus (see 1st MT Base Osteotomy, or MC-Medial-OWO, Chapter 8)
b. Make a longitudinal incision dorsal to the hallux proximal phalanx and the distal half of the 1st MT
c. Release or retract the EHL
d. Incise the 1st MTP joint capsule on the medial, dorsal, and lateral sides
e. Using a microsagittal saw, resect the proximal articular surface of the proximal phalanx of the hallux perpendicular to the shaft of the bone
f. Using a microsagittal saw, remove the distal articular cartilage and a portion of the epiphysis of the 1st MT with an osteotomy that is approximately 10° valgus from the long axis of the 1st MT in the frontal plane and angled approximately 15° to 20° extended from the long axis of the 1st MT in the sagittal plane. This will create a 10° hallux valgus angle and 15° to 20° of fixed dorsiflexion at the arthrodesis site of the MTP joint. This assumes an average height longitudinal arch. Less dorsiflexion is required in a flatfoot that is not undergoing reconstruction, and more dorsiflexion is required in a cavus foot that is not undergoing reconstruction.
g. Fixation can be with crossed smooth Steinmann pins, staples, a mini-fragment plate and screws, or a retrograde large diameter screw inserted from the plantar flair of the proximal phalanx across the fusion site and up the 1st MT medullary cavity.
h. Approximate the skin edges with interrupted subcutaneous 3-0 absorbable sutures and a running subcuticular 4-0 absorbable suture
i. Apply a short-leg non–weight-bearing cast
j. Maintain cast immobilization for at least 6 weeks, based on the other concurrent procedures performed
3. Pitfalls
a. Failure to correct the other foot deformities concurrently
b. Failure to create the appropriate dorsiflexion at the arthrodesis site
4. Complications
a. Wound dehiscence over the plate
i. Avoid by careful tissue handling
Midfoot Wedge Resection/Arthrodesis
1. Indications
a. Severe, rigid, long-standing cavovarus foot deformity (see Chapter 5) in an older adolescent or young adult, as an alternative to a triple arthrodesis
2. Technique (Figure 8-39)
a. Perform a plantar release (see Chapter 7)
b. Make a longitudinal incision over the dorsum of the midfoot from the ankle to the 3rd MT shaft
c. For a very severe deformity, it will be easier to use parallel dorsomedial and dorsolateral longitudinal incisions
d. Isolate and retract the superficial peroneal and sural nerves
e. Bluntly elevate all soft tissues off the dorsum of the midtarsal bones
f. Insert a 0.062″ smooth Steinmann pin from medial to lateral through the proximal bodies of the navicular and cuboid perpendicular to the long axis of the hindfoot in the frontal plane
g. Insert a second 0.062″ smooth Steinmann pin from medial to lateral through the distal bodies of the 3 cuneiform bones and the cuboid perpendicular to the long axis of the forefoot in the frontal plane
h. Insert a third 0.062″ smooth Steinmann pin from dorsal to plantar in the proximal body of the cuboid perpendicular to the desired plantar surface of the hindfoot
i. Insert a fourth 0.062″ smooth Steinmann pin from dorsal to plantar in the distal body of the cuboid perpendicular to the desired plantar surface of the forefoot
j. With retractors dorsal and plantar to the midfoot bones and using a sagittal saw, make one osteotomy immediately proximal to the two anterior pins and a second osteotomy immediately distal to the two posterior pins
k. Remove the large wedge of bone
l. Bring the cut surfaces together and rotate the forefoot and hindfoot until the rotational deformities are corrected. The small joints of the midtarsal bones will not align anatomically, but will be sacrificed as an alternative to sacrificing the more important subtalar joint (which takes place in a triple arthrodesis)
m. Fix the forefoot on the hindfoot with large gauge, smooth, crossed Steinmann pin inserted retrograde and left exposed distally for removal in clinic
n. Apply a very well-padded short-leg non–weight-bearing fiberglass cast that is immediately bivalved
o. Overwrap the cast with fiberglass before hospital discharge
p. Change the cast and remove the wires in clinic at 6 weeks and apply a final partial weight-bearing cast for 4 to 6 weeks
3. Pitfalls
a. Failure to improve the severe and rigid deformity with a first-stage D-PMR (see Chapter 7)
b. Failure to use the Steinmann pins as guides for the complex bone cuts
4. Complications
a. PT neurapraxia
i. Avoid by gentle serial stretching casts after the D-PMR and before the wedge resection/arthrodesis in very severe, rigid deformities
b. Wound edge necrosis
i. Avoid by gentle serial stretching casts after the D-PMR and before the wedge resection/arthrodesis in very severe, rigid deformities
c. Pin tract infection
i. Avoid by relieving skin tension at the insertion site before applying the felt pledget around the pin
Calcaneocuboid Joint Arthrodesis
See earlier in this Chapter.
Subtalar Arthrodesis
1. Indications (see Management Principle #13, Chapter 4)
a. Painful degenerative arthrosis in the talocalcaneal joint associated with severe, rigid, long-standing plano-valgus foot deformity in an older child or adolescent, typically one with an underlying severe neuromuscular disorder. The talonavicular and calcaneocuboid joints should be free of degenerative arthrosis.
2. Technique (Figure 8-40)
a. Make a modified Ollier incision in a Langer’s skin line from the superficial peroneal nerve to the sural nerve half way between the beak of the calcaneus and the tip of the lateral malleolus (Figure 8-17A).
b. Elevate the soft tissues from the dorsal surface of the anterior calcaneus in the sinus tarsi. Avoid exposure of, or injury to, the capsule of the calcaneocuboid joint
Figure 8-39. A. The midfoot osteotomy operation may be performed through either one long midline incision or two separate incisions, one over the dorsomedial aspect of the navicular and first cuneiform bone and the second over the cuboid bone in line with the 4th MT. In the severe cavus foot, the single incision makes it difficult to reach the lateral extent of the cuboid bone. The incision must extend from the dorsal aspect of the talar neck distally as far as the middle of the MTs. Through this incision the entire area of the osteotomy can be exposed extraperiosteally without interference from the anterior or PT tendons. It is also easier to see the osteotomy through this single incision. It is important that the operation be preceded by a plantar release. B. After the skin and subcutaneous tissues are divided, the interval between the extensor tendons to the second and third toes is developed. The neurovascular bundle lies between the extensor tendons to the second and great toes. In developing this interval, care should be taken to interrupt as few vessels as possible. The arcuate artery coming off the dorsalis pedis artery runs laterally at the level of the tarsal–MT joints. If this is identified, an effort to preserve it should be made. C. After this interval is developed, the midtarsal bones should be exposed extraperiosteally between Chopart joints proximally and Lisfranc joints distally, while preserving and protecting those joint capsules. Medially, the dissection should go completely around the navicular first cuneiform joint; laterally, it should go completely around the cuboid bone. Most of the cuboid bone should be exposed, but the joints proximal and distal to it do not need to be entered. Steinmann pins can be used as guide wires to mark the proximal and distal limits of the bone wedge that is to be removed. Insert one from medial to lateral parallel with, and immediately distal to, Chopart joints through the navicular and cuboid. Insert another one from dorsal to plantar at the level of this transverse pin perpendicular to the desired longitudinal axis of the hindfoot. Insert a third pin parallel with, and immediately proximal to, Lisfranc joints through the three cuneiforms and the cuboid. A fourth pin is inserted from dorsal to plantar at the level of the third pin perpendicular to the desired longitudinal axis of the forefoot. D. The osteotomy is performed using a large half-inch osteotome, chisel, or sagittal saw. The plantar soft tissues are protected with wide, curved Crego retractors. The proximal cut is made immediately distal to, and parallel with, the plane created by the two proximal guide pins. It passes through the mid-body of the navicular and the proximal end of the cuboid. This cut is estimated to be perpendicular to the hindfoot axis. The distal osteotomy is made immediately proximal to, and parallel with, the plane created by the two distal guide pins. It passes through the mid-body of each of the three cuneiform bones and the distal end of the cuboid. It is made perpendicular to the axis of the forefoot. It is to be noted that unlike the medial half of the osteotomy, the joints on either side of the cuboid bone are not entered. Rather, the wedge is removed entirely from the cuboid bone. To avoid excessive shortening of the foot, the osteotomies should be fashioned so that no gap of bone is present at the plantar apex of the wedge. The osteotomy is closed by elevating the forefoot (E). (E). It is possible to rotate the distal segment, if needed, to correct pronation deformity of the fore foot. Often the 1st MT will be more depressed than the others. This can be corrected by supinating the forefoot; however, care should be taken not to produce an unintended malrotation. Much depends on the angulation and flexibility of the hindfoot. The osteotomy can be fixed with either two Steinmann pins or multiple staples. The dorsal surface of the cuneiform bones is usually higher than the navicular, and this may make staple fixation more difficult. Secure fixation with Steinmann pins is not as easy as it may first appear (F) as the medial pin may pass too far plantarward. The medial pin is inserted first. It must start in the 1st MT at an oblique angle directed dorsally and laterally. This pin should engage the 1st MT, the first cuneiform bone, the navicular, and the talus. The lateral pin is started distal to the flare at the base of the 5th MT and is aimed medially and slightly dorsally, crossing the cuboid bone and entering the calcaneus. The ends of the pins are left protruding outside the skin. A well-padded, non–weight-bearing short-leg cast is applied. The foot is kept elevated for the first few days. The patient is then ambulated with a three-point, non–weight-bearing crutch gait for 6 weeks. After 6 weeks the cast and the pins are removed in the office. A short-leg walking cast is applied, and the patient is permitted partial weight-bearing for an additional 4 to 6 weeks, at which time healing should be complete. (From Mosca VS. The Foot. In: Weinstein S, Flynn J, eds. Lovell and Winter’s Pediatric Orthopaedics. 7th ed. Philadelphia, PA: Lippincott Williams& Wilkins; 2013.)
c. Partially decorticate the exposed non-articular surfaces of the talus and the calcaneus in the sinus tarsi with a high speed burr
d. Invert the subtalar joint to neutral alignment, and never to varus
Figure 8-40. Subtalar Arthrodesis.
e. Insert a fully threaded 4.5 mm cannulated screw percutaneously in an oblique trajectory from the antero-dorso-medial head/neck of the talus to the posteroplantar-lateral calcaneus using mini-fluoroscopic guidance
f. Insert and impact morselized cancellous bone graft into the sinus tarsi until the cavity is filled
g. Lengthen the tendo-Achilles or the gastrocnemius tendon (see Chapter 7) if contracted, based on the Silfverskiold test (see Assessment Principle #12, Chapter 3).
h. Assess the forefoot for structural supination deformity by cupping the heel in one hand, while maintaining neutral ankle dorsiflexion, and visually sighting down the long axis of the foot from toes to heel. If the plane of the metatarsal heads is supinated in relation to the long axis of the tibia or there is dorsal-plantar hypermobility of the first metatarsal-medial cuneiform joint, a plantar flexion plantar-based closing wedge osteotomy of the medial cuneiform is needed (see this Chapter) (Figure 8-19).
i. Approximate the skin edges of all incisions with interrupted subcutaneous 3-0 absorbable sutures and a running subcuticular 4-0 absorbable suture
j. Apply a well-padded short leg fiberglass non-weight-bearing cast and immediately bivalve it to allow for swelling overnight. Obtain final radiographs of the foot in the cast in the recovery room
k. Over-wrap the cast with fiberglass the following day before hospital discharge
l. At 6 weeks, the cast is removed to obtain simulated standing AP, lateral, and oblique radiographs of the foot.
i. An AFO mold is obtained in most cases.
ii. A below the knee weightbearing cast is applied.
m. Upon removal of this cast 6 weeks later, final simulated standing AP, lateral, and oblique radiographs of the foot are obtained. The AFO is fitted.
3. Pitfalls
a. Failure to fully correct the deformity
b. Failure to identify and concurrently correct rigid forefoot supination deformity
c. Failure to identify and concurrently correct equinus deformity
4. Complications
a. Over-correction to varus
i. Avoid by confirming appropriate correction intraoperatively with minifluoroscopy
b. Non-union
i. Avoid by adequate decortication of the exposed non-articular surfaces of the talus and the calcaneus in the sinus tarsi with a high speed burr
• complete filling of the sinus tarsi with morselized cancellous bone graft
• stable fixation with the trans-articular screw
• adequate immobilization based on post-operative radiographs
c. Persistent equinus
i. Avoid by lengthening the Achilles or gastrocnemius tendon, based on the Silfverskiold test, and confirming adequacy of ankle dorsiflexion with the knee extended after subtalar joint stabilization
d. Persistent forefoot supination
i. Avoid by assessing forefoot supination intraoperatively after the subtalar joint has been stabilized and the heel cord has been lengthened. Correct it with a medial cuneiform osteotomy if identified
Triple Arthrodesis
1. Indications (see Management Principle #13, Chapter 4)
a. Painful degenerative arthrosis in the talocalcaneal and talonavicular joints associated with severe, rigid, long-standing cavovarus foot deformity in an older adolescent or young adult
b. Painful degenerative arthrosis in the talocalcaneal and talonavicular joints associated with severe, rigid, long-standing plano-valgus foot deformity in an older adolescent or young adult, typically one with an underlying severe neuromuscular disorder
2. Technique (Figure 8-41)
a. Because of intentional and gratifying inexperience with this technique, I am not expert and have no “tricks of the trade” (see Management Principle #13, Chapter 4). Therefore, the technique is not discussed in detail, but images and legends from Mosca VS. The Foot. In: Weinstein SL and Flynn JM, editors. Lovell and Winter’s Pediatric Orthopaedics, 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:1441–45 have been borrowed for this chapter.
3. Pitfalls
a. Failure to fully correct the hindfoot deformity
b. Failure to identify and concurrently correct rigid forefoot supination or pronation deformity
c. Failure to identify and concurrently correct equinus deformity
4. Complications
a. Over-correction to varus in a valgus hindfoot or persistence of varus in a varus hindfoot
i. Avoid by confirming appropriate correction intraoperatively with minifluoroscopy
b. Non-union
i. Avoid by
• adequate resection of all articular surfaces and subchondral bone
• stable fixation with trans-articular screws, staples, wires, etc.
• adequate immobilization based on post-operative radiographs
b. Persistent equinus
i. Avoid by lengthening the Achilles or gastrocnemius tendon, based on the Silfverskiold test, and confirming adequacy of ankle dorsiflexion with the knee extended after joint stabilizations
c. Persistent forefoot supination or pronation
i. Avoid by assessing forefoot supination or pronation intraoperatively after the joints have been stabilized and the heel cord has been lengthened. Correct it with a medial cuneiform osteotomy if identified
Figure 8-41. Before beginning the triple arthrodesis operation, the surgeon should give some thought and planning regarding the wedges of bone to be removed and, in particular, the amount of bone to be removed. Simplify the cuts to parallel and perpendicular in relation to obvious large bony landmarks. It is not particularly beneficial to preoperatively plan precise wedges with cutouts, since the three-dimensional nature of the deformities makes such planning imprecise. Visualizing the foot at surgery and making the osteotomy cuts to create the wedges, as described in the subsequent discussion, seems much more practical and accurate. The most common deformity for which triple arthrodesis is performed is fixed cavovarus deformity. To correct this deformity, a laterally-based wedge of bone is removed from each of the joints to be resected. Conceptually, two wedges of bone at right angles to each other are removed. The wedge that will allow correction of the forefoot will excise the TN and calcaneocuboid joints. To achieve correction to a neutral position, the distal cut is perpendicular to the long axis of the forefoot and the proximal cut is perpendicular to the longitudinal axis of the calcaneus (A). When these two surfaces are opposed, the forefoot should be straight. To correct the varus of the hindfoot, a laterally based wedge must be removed from the subtalar joint. To correct the heel to a neutral position, the proximal cut from the undersurface of the talus should be perpendicular to the long axis of the tibia (or parallel with the ankle mortise), whereas the distal cut from the superior surface of the calcaneus should be parallel to the bottom of the heel (B). When these two surfaces are apposed, the heel should be in neutral. A triple arthrodesis for fixed valgus deformity is extremely difficult. This is because the medially-based wedges that are created using the espoused principles must be removed from the lateral side (C). This task is simplified if all the joints are widely released by extensive capsulotomies and the interosseous ligament of the subtalar joint is sectioned. A laminar spreader can be used to hold the joints open. Calcaneocavus deformity is the most uncommon indication for triple arthrodesis. In this circumstance a posteriorly based wedge is removed from the subtalar joint, which allows correction of the calcaneus deformity. A dorsal wedge is removed from the TN and calcaneocuboid joints to allow the forefoot to be dorsiflexed (D). (continued) A slightly different technique is used for mild deformities. The joint surfaces are simply removed with osteotomes and curettes until there is sufficient resection to gain the desired correction (E). The triple arthrodesis operation is illustrated for the most common deformity: cavovarus. The patient is placed on the operating table with a sandbag under the hip on the side to be operated, thus bringing the lateral side of the foot into better position. The incision is a straight lateral incision that crosses the lateral side of the TN joint and the distal end of the calcaneus. It should extend from just medial to the most lateral extensor tendons dorsally to just past the peroneal tendons volarly. There should be no undermining of the skin edges. The superficial peroneal and sural nerves are retracted and protected. After the fascia over the extensor brevis muscle is incised, the proximal insertion of this muscle is identified and the muscle is elevated to expose the lateral capsules of the calcaneocuboid and TN joints. The fibrofatty tissue is removed from the sinus tarsi, exposing the lateral aspect of the subtalar joint (F). The TN and calcaneocuboid joint capsules are incised circumferentially, exposing the joint surfaces. It will assist removal of the bone wedges from the subtalar joint if the capsule of the subtalar joint is also nearly circumferentially released. This can be done by sliding a curved periosteal elevator (e.g., a Crego elevator) around the posterior and then medial aspect of the subtalar joint until it rests along the medial side of the joint. At this point, almost the entire capsule of the subtalar joint can be visualized and incised, the interosseous ligament can be divided, and a large bone skid can be used to pry the joint open. This will give the surgeon an excellent view of the two bony surfaces of the subtalar joint that are to be excised. The wedges of bone are now excised. The subtalar joint is resected first. Most of the bone for the correction should be removed from the calcaneus. It is better to use a chisel than an osteotome for these cuts. The chisel, with its flat surface as opposed to the double-beveled surface of an osteotome, is easier to keep on a straight course (G). The cut in the bottom of the talus should be parallel with the ankle mortise from lateral to medial (H). The cut into the dorsal surface of the calcaneus should be parallel to the bottom of the heel (I). It is best to make the most proximal and distal aspects of these cuts first and the middle portion in between them last. This is because the middle part will be the most difficult to remove with remaining capsule attached to the prominent sustentaculum tali and the most worrisome to cut through with the neurovascular bundle in close proximity. If these cuts are made correctly, the heel will be in neutral alignment regarding varus and valgus when the two cut surfaces are apposed. The same principle is used in aligning the forefoot. The cuts in the navicular and the cuboid should be perpendicular to the longitudinal axis of the forefoot (J, K), whereas the cuts in the distal talus and calcaneus should be perpendicular to the longitudinal axis of the hindfoot or calcaneus (L). When the wedges are removed, the foot is placed in the corrected position and the surfaces are inspected. Good coaptation should be present to ensure prompt healing. Trim additional bone as needed. The external contour of the foot should be inspected to ascertain that the desired three-dimensional alignment of the foot has been achieved. If so, the resected joint surfaces are held together with staples, screws, wires, or combinations of these internal fixation devices. A well-padded short-leg non–weight-bearing cast is applied and bivalved to allow for the expected significant swelling that will occur over the next few days. Radiographs are obtained, and the cast is changed to a weight-bearing cast at 6 weeks. At 12 weeks, healing is usually complete, and no further cast protection is needed (M). (From Mosca VS. The Foot. In: Weinstein S, Flynn J, eds. Lovell and Winter’s Pediatric Orthopaedics. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013.)