Ankle Arthritis & Fusion:Open, Mini, Arthroscopic

Selene G. Parekh, MD, MBAAssociate Professor of Surgery

Partner, North Carolina Orthopaedic ClinicDepartment of Orthopaedic Surgery

Adjunct Faculty Fuqua Business SchoolDuke University

Durham, NC919.471.9622

http://seleneparekhmd.comTwitter: @seleneparekhmd

Ankle Arthritis• Ankle is more commonly injured than any other joint in

the body

• Subject to more WB force per cm2 than any other joint

• Prevalence of ankle arthritis is 9 x’s lower than at the hip or knee

• Trauma is the most common cause• Ankle sprains, ankle fx, pilon fx …

Indications

• Arthrosis

• Pain

• Deformity

• Failed TAR

• Charcot ankle

• Degenerative Arthritis• Rheumatoid Arthritis• Post Traumatic/ Acquired Deformity• Instability from Paralytic Disorders• Neuropathic Joint• Failed Total Ankle Replacement

Goals

• To create a painless, stable, plantigrade foot

Surgical Considerations

• Minimal periosteal stripping

• Rigid internal fixation• Screws• Plates

• External fixation

• Attention to alignment and position• Plantigrade foot• 5-7 deg valgus• Neutral to 5 degrees DF• Rotation equal to other side• Posterior displacement: anterior-anterior

Preoperative Planning

• R/O subtalar DJD• May require CT scan

• May need combined fusion of both joints

Preoperative Planning

• R/O AVN talus• May require MRI

• May require bone graft

• May require tibio-calcaneal fusion

Preoperative Planning

• R/O fixed equinus

• Achilles contracture• TAL• Gastroc recession

• Anterior osteophytes• Excision of osteophytes• +/- tendoachilles lengthening

Preoperative Planning

• Varus or Valgus deformity• Plafond fracture• Talar collapse

• Bone grafting

• Osteotomy

Problems

• Nonunion rate – 0 – 40%

• Initial pain relief can be elusive

• Functional limitations• Uneven surfaces>stairs>objects from floor=driving

• Shoe modifications• SACH heel/rocker-bottom sole

• Adjacent joint degeneration• 50% arthroses within 7 yrs

Concepts

• Technical considerations– In-situ fusion

• Usually no deformity

– Deformity-correcting fusion

Concepts

• Soft tissue considerations– Avoid placing tension on skin edges

– Utilize full-thickness flaps

– Cognizant of cutaneous nerves

Surgical Principles

• Create broad, congruent cancellous surfaces• Remove all cartilage• Feather and penetrate into subchondral bone

• Use bone graft or substitutes to fill defects

• Stabilize w/ rigid fixation

• Appropriate alignment to create a plantigrade foot

Complications

• Infections– Careful soft tissue handling, removal of devitalized

tissue, prevention of hematoma

• Nerve disruption/entrapment

• Nonunion– Prepare joint, adequate fixation

• Malalignment

Ankle Arthrodeses

• Open

• Mini-open

• Arthroscopic-assisted

Ankle Fusions - Open

• Advantages• Easier visualization

• Ability to address deformity

• Better opposition of joint surfaces

• Disadvantages• More soft tissue dissection

Open

• Lateral/Transfibular approach• Never a TAR candidate

• Posterior• Poor anterior or lateral skin

• Anterior• All others

Open: Lateral

• Position: supine• Incision

• 10cm prox to tip of fibula base of 4th MT

• Structure at risk• Anterior branch sural n.• Peroneals

Open: Lateral

• Full thickness flaps• Periosteum of fibula stripped anteriorly and

posteriorly• Protect peroneals

Open: Lateral

• Fibular osteotomy 2cm proximal to level of joint• Proximal-lateral• Distal-medial

Open: Lateral

• Morcellize for bone graft

• Use for lateral onlay graft

Open: Lateral

• Remove osteophytes

• Remove cartilage and subchondral bone

• Feather cancellous surfaces

Open: Posterior

• Position: prone• Incision

• 10-12cm from glabourous skin

• Structure at risk• Sural n.• Tibial n.• Achilles • FHL tendon

Open: Posterior

• Split Achilles

• Maintain full thickness flaps

Open: Posterior

• Open deep posterior compartment• Find FHL muscle belly• Retract medially

Open: Posterior

• Enter joint

• Prepare joint

• Position and fixation with screws

Open: Anterior

• Position: supine• Incision

• 1 fingerbreadth lateral to ant tibial spine• 10cm (2/3 prox, 1/3 distal)

• Structure at risk• Medial branch SPN• EHL, TA

Open: Anterior

• Find EHL distally and remove from sheath

Open: Anterior

• Enter joint• Prepare joint• Position and fixation with screws or plates

• Position: supine• Extended scope portals• Use lamina spreaders• Debride joint• Only do if no deformity• Minimally invasive and good

results

Mini-Open

Mini-Open

Mini-Open

• Place laminar spreader in one wound and prepare from the other

• Posterior 1/3 ankle difficult to visualize

• Prepare joint

• Position and fixation with screws

Mini-Open Results

• Early radiographic evidence on healing @ 6wks

Paremain, 1996.

• Clinical fusion = 100%

Ankle Fusions - Arthroscopic

• Advantages• Minimal dissection

• Decreased wound healing

• Minimal interference with surrounding tissue

• Disadvantages• Technically challenging

• Less optimal fusion surface

• Inability to correct deformity

Ankle Arthrodeses: SAA

• Indications

– Similar to open

– Minimal deformity of ankle• Limited ability to correct varus/valgus tilt

Ankle Arthrodeses: SAA

• Prepare room for ankle arthroscopy

• Distract• Non/invasive

• Aggressive shaver for anterior synovectomy

Surgical Armamentarium

• Small joint arthroscope 2.7 30 degree• Currette small joint (need long narrow shaft and

curved if available)• Large joint shaver

• 4.0 round burr• 5.5 shaver aggressive• Yankauer suction tip

• Noninvasive ankle distractor

Ankle Arthrodeses: SAA

• Residual cartilage removed

• Shaver/currettes

• Burr used to make pockmarks• Fluid on/off

Ankle Arthrodeses: SAA

• Average 2.5 hours Ogilvie-Harris ,1993

• Complication rate 9.8% Ferkel, 1993

• 50% nerve injury

• Union rate of 100% Myerson, 1989

• 34/35 overall fusion rate Ferkel, 2005

• 31/35 solid fusion arthroscopically Jerosch ,2005

Ankle Arthrodeses: Open vs. SAA

• SAA– Less morbidity– Decreased time to fusion

• 4 – 8 wks less

• Open– Can address deformities

Ankle Arthrodeses: Open

• Alignment & fixation• Ant aspect of talus aligns ant cortex of tibia

• Screws• W/in sinus tarsi, above lat process• Aim screws medially & as proximal as possible• Ensure all threads are in proximal piece

Fixation Options

• Screws• Size

• Large: 6.5, 7.0, 7.3• Cannulated vs solid

• Orientation

Ankle Fusions - Internal Fixation Options

• 2 Parallel Screws - optimal compression

• 2 Crossed Screws - optimal stability

• 2 Parallel and one Cross Screw

• 2 Parallel and one P-A screw

Ankle Arthrodeses: Open

Open: Lateral

Fixation Options

• Plates• Anterior

• Solid arthrodesis 12 weeks (no BG), 14 wks (BG)

• AOFAS from 37 to 68. • 93% were satisfied. No complications .• CONCLUSION: The anterior double plating

system: Reliable method to achieve solid tibiotalar arthrodesis, even with loss of bone , e.g. failed TAA

Anterior double plating for rigid fixation of isolated tibiotalar arthrodesis.

Plaass C, Knupp M, Barg A, Hintermann B. Foot Ankle Int. 2009 Jul;30(7):631-9.

Fixation Options

• Plates• Anterior

Fixation Options

• Plates• Anterior

Fixation Options

• Plates• Lateral

External Fixation

• Advantages• Avoid metal in infected bone• Better control in poor quality bone• May lengthen and fuse at some time - Ilizarov

• Disadvantage• Pin tract infections• Patient acceptance of fixator• Pin breakage

Ankle Arthrodeses: Open

• Post-op– Dressings for 10-12d

– SL-NWB cast

– WB CAM boot

RE ECT

the ankle

the foot