Fulkerson Technique

synonyms: anteromedial tibial tubercle transfer, AMZ, Fulkerson

CPT

• 27418 Anterior tibial tubercleplasty (eg, Maquet type procedure)

Anatomy

Indications

• Lateral patellar tilt / subluxation with Grade III or IV chondromalacia on the distal medial and/or lateral patellar facets.
• Patellofemoral arthritis.
• Failed lateral release.

Contraindications

• Normal patellar articular cartilage: in this case there is no need to anteriorize the tibial turbercle and a straight medial transfer (Tillat) is inidcated.
• Absence of patellar malalignment
• Diffuse patellar Grade III/IV Chondromalacia
• Obesity
• Smoker
• Diabetic

Alternatives

• Non-op treatment: brace, VMO strengthenging, activity modifications
• Lateral release
• Patellofemoral arthroplasty

Planning / Special Considerations

• Councel patients on expected outcomes of improved symptoms, not completely normal knee.
• Moving tibial tubercle anteriorly shifts the more proximal patellar articular cartilage into contact earlier in the flexion arc. This unloads distal patellar articular lesions.
• Lateral and distal lesions with lateral patellar tracking (most common)= anteromedial tibial tubercle transfer via and oblique osteotomy. (Fulkerson JP, Am J Sports Med 1990;18:490)
• Lateral lesion with lateral tracking = Trillat tibial tubercle transfer
• Distal lesion with normal proximal cartilage (uncommon) = anterioriation of tubercle
• consider concomitent autologous or allograft osteochondral core transfer especially if articular lesion is on trochlear side.

Technique

• Sign operative site.
• Pre-operative antibiotics, +/- regional block.
• General endotracheal anesthesia
• Supine position. All bony prominences well padded.
• Examination under anesthesia.
• Tourniquet placed high on the thigh.
• Prep and drape in standard sterile fashion.
• Perform knee arthroscopy documenting condition of patellar cartilage and location of lesions. Patients should have near normal proximal medial facet cartilage for a successful anteromedial transfer. Perform chondroplasty as indicated.
• Exsanguinant leg the Eschmar bandage. Inflate tourniquet.
• Anterolateral longitudinal incision extending from the lateral patella to 5-6cm distal to the tibial tubercle.
• Expose patellar tendon and lateral retinaculum.
• Perform lateral release to the superior pole of the patella.
• Expose tibial tubercle both medially and laterally by subperiosteal sharp dissection. Expose the distal patellar tendon medial and laterally.
• Place custom anterior retractor on the proximal lateral tibia.
• Place Mitek Tracker guide and pin in place with slope determined based on pre-operative plan. Osteotomy should taper anteriorly distally.
• Begin osteotomy with multiple drill holes and saw.
• Complete osteotomy with osteotome. Two cuts are needed proximally ensure tibial tubercle remains intact
• Displace the tibial tubercle fragment anteromedially along the osteotomy plane. @15mm anteriorization.
• Secure tibial tuberlce with bone clamp and place knee through ROM ensure central tracting in the trochlear groove.
• Place two 4.5mm cortical lag screws for fixation. Proximal screw is placed 1-2cm distal to the patellar tendon insertion.
• Assess patellar tracking.
• Irrigate.
• Close in layers.

Complications

• nonunion
• tibia fracture (avoid creating stress-riser in tibia with osteotomy cut)
• Compartment syndrome
• Skin slough
• Continued symptoms
• Painful hardware: generally screws are removed at 8-12 months post-op.
• Infection
• DVT/PE
• Neurovascular injury
• Overcorrection . patellar instability
• Undercorrection
• Neuroma
• Stiffness

Follow-up care

• Post-op: knee immobilizer or hinged brace locked in extention. Active and passive ROM exercises are start early 1-2 x per day. Toe-touch weight bearing.
• 7-10 Days: wound check, Continue knee immobilizer, daily ROM exercises. 25% Weight-bearing with crutches.
• 6 Weeks: Check xrays. wean out of immobilizer, Start active strengthening at 8 weeks. Gradually increase weight bearing to full-weight bearing provided xrays show evidence of union.
• 3 Months:
• 6 Months:
• 1Yr:

Outcomes

Review References

• Fulkerson JP, in Masters Techniques in Orthopaedic Surgery: The Knee, 2nd ed.
• °