72 - Arthrodesis of Rearfoot and Ankle Flashcards
Triple arthrodesis
- “The essential aim of this kind of reconstructive surgery is the improvement of the function of the foot” - Ryerson 1923
- Triple arthrodesis: STJ, talonavicular and calcaneocuboid joint fusions
- Many procedures offered: Ryerson (first choice on boards), Hoke (second choice on boards), Lambrinudi, Brewster, Dunn, Seiffert or beak
- Each with their own advantages and disadvantages
- The indications have always remained the same
- I WILL NOT TEST YOU ON MODIFICATIONS
Indications for arthrodesis
- Pain
- Deformity
- Instability
- Progression of any of the above
McGlamry’s list of indications for triple arthrodesis
- Valgus foot deformity
- Varus foot deformities
- Miscellaneous
Valgus deformity indivations for triple arthrodesis
o Collapsing pes planovalgus
o Ruptured tibialis posterior tendon
o Tarsal coalition and arthritic deformities (congenital, rheumatoid, degenerative, post-traumatic)
Varus deformity indications for triple arthrodesis
o Cavus
o Cavovarus
o Talipes equinovarus
Miscellaneous indications for triple arthrodesis
o Lateral ankle instability and ankle equinus
o Neuromuscular disease (hereditary familial sensorimotor neuropathies, paralytic deformities, Charcot joint deformities, other diseases affecting spinal cord and brain)
McGlamry’s list of conditions requiring triple arthrodesis
- Idiopathic collapsing pes planovalgus deformity
- Peroneal spastic flatfoot
- Tarsal coalition
- Congenital vertical talus
- Rheumatoid arthritis
- Degenerative arthritis
- Posttraumatic degenerative arthritis
- Ruptured tibialis posterior tendon
- Idiopathic cavus and cavovarus deformities
- Congenital clubfoot (uncorrected)
- Poliomyelitis
- Spina bifida
- Friedreich’s ataxia
- Charcot-Marie-Tooth disease
- Muscular dystrophy
- Cerebral palsy
- Myelodysplasia
- Arthrogryposis
Complications of triple arthrodesis
- Pseudoarthrosis/non-union (occurs 7-23% of the time)
- Development of DJD in adjacent joints
- AVN
- Ankle instability (kind of related to DJD)
Triple arthrodesis rate of non-union
o Hoke 7% o Ryerson 16% o Brewster 20% o Lambrinudi 33% o ***Usually at talonavicular joint***
Triple arthrodesis positioning
o May accommodate deformity in all three body planes by resection of bone at the joints
o Arthrodesis position of rearfoot should be 0-5 degrees of VALGUS
o Arthrodesis position of forefoot should be PARALLEL to the ground and PERPENDICULAR to the heel
NOTE: YOU CAN CORRECT DEFORMITIES IN MULTIPLE PLANES WITH A TRIPLE ARTHRODESIS PROCEDURE – THIS IS A MAJOR TAKEHOME MESSAGE
o There are images on the slides regarding all the different modifications you can make to fix deformities in different planes
“Thou shall not varus”
- This is something you will hear again and again
- You never want the fusion position to be in varus
- This is the one thing that you need to make sure when you permanently fixate the subtalar joint
- You CANNOT accommodate for this fixed position
- Varus deformity in a foot (even if it naturally occurs as an uncompensated varus deformity), but you get ankle instability, sprains and many other pathologies occur
- This is essentially what we will do if we fixate the STJ in a varus position
- You will see patients who come into your clinic with a previous triple arthrodesis and they have been fixated in varus, it is an automatic need for a revision surgery
Lateral incision
- Ollier’s incision” is a lateral approach to a triple arthrodesis from the tip of lateral malleolus to the base of the metatarsals
- Can be modified (swing under fibula) and go down a little bit further for better exposure of the posterior facet of the STJ
Medial incision
- Similar to lateral incision, but on medial aspect of the foot
- Start below the medial malleolus (or slightly further back) and go down to at least the naviculocuneiform joint
Cartilage removal then fixation
- First you always resect the cartilage from the midtarsal joint (MTJ), which includes both the calcaneocuboid joint (CC joint) and the talonavicular joint (TN joint)
- This often “slacks up” the soft tissues and allows easier access to the subtalar joint (STJ)
- After resecting the cartilage from the STJ, we fuse in the reverse order, meaning we then fuse the STJ first
- When fusing the joint you will first temporarily fixate the STJ with a cannulated guidewire to assure appropriate positioning before inserting the screw for permanent fixation
- AVOID varus when positing the STJ for fixation
Fixation for triple arthrodesis
- Three 6.5 mm partially threaded cancellous screws (lag by design)
- May use smaller screws or staples across midtarsal joint
- May staple all three arthrodesis sites
- Steinmann pins
Post-operative care for triple arthrodesis
- Short leg cast for 12 weeks non-weightbearing
- Partial weightbearing for additional 4 weeks
Now we are moving onto ANKLE arthrodesis
FYI
Indications for ankle arthrodesis
- Severe pain and/or deformity
- DJD: S/P ankle fracture
- RA
- Talar collapse
- Infection
- Drop foot
- Congenital deformities
- Ankle implant revision
Pre-operative evaluation for triple ankle arthrodesis
- Evaluate adjacent joints
- Neuropathy
- Bone stock
- Patient expectations (patients are fearful of losing ankle motion, but they don’t have it now and what they do have is painful – also, can’t wear high heels after procedure)
Surgical approaches to ankle arthrodesis
- Transverse anterior
- Longitudinal anterior
- Lateral (with fibular osteotomy)
- Medial (with tibial osteotomy)
- Combination
Ankle arthrodesis procedures
- Articular resection with or without bone grafting
- Anterior arthrodesis with inlay grafting
- Articular resection with malleolar osteotomy
- Dowel arthrodesis
- Compression arthrodesis
- Arthroscopic
Arthrodesis positioning
- Right angle to leg (0° dorsiflexion***)
- Body can tolerate 5 degrees of plantarflexion
- External rotation of 13-15 degrees (line up tibial tuberosity with the 2nd toe to achieve this***)
Fixation for ankle arthrodesis
- Two 6.5 mm partially threaded cancellous screws
- External fixation device (can be used)
Post-operative care for ankle arthrodesis
- Short leg cast for 12 weeks non-weightbearing
- Partial weight bearing for 4 weeks
Complications of ankle arthrodesis
- Non-union (15-50%)
- Degenerative changes in adjacent joints
STUDY: Open vs arthroscopic ankle arthrodesis: Comparison of subsequent procedures in large database
- Level 3 retrospective study from 2005 to 2011 in JFS 2016
- 7,322 open technique and 1,152 arthroscopically – Open technique is MORE popular
- They compared two approaches, but what they are really looking at is “subsequent procedures” which really means arthritis in adjacent joints needing surgery
- Example: you do an ankle arthrodesis and therefore put more demand on the STJ, leading to arthritis of the STJ
- In open arthrodesis, 5.6% needed a subsequent procedure compared to arthroscopic arthrodesis in which only 2.6% of patients needed a subsequent arthrodesis
- By doing an open approach, there are more issues with adjacent joints, but still overall a low complication rate
- If you are going to do an ankle arthrodesis, you need to discuss this with your patients
Other arthrodesis procedures
- Pan-talar arthrodesis = ankle arthrodesis PLUS triple arthrodesis (LONG SURGERY – 4+ hours)
- Isolated subtalar arthrodesis (if this is the only arthritic joint)
- MTJ arthrodesis
