Non-operative
Results
90% respond
- very important
- 6 - 12 months minimum before offering surgery
Physiotherapy
1. Stretches
- quads stretches
- ITB
- lateral retinaculum
2. Quads strengthening
- avoid pain
- PFJ contact pressures lowest from 0-30o
- short arc quads extension
- closed chain VMO exercises
3. Taping / bracing
- patella cut out brace
- little hard evidence
- may provide proprioceptive feedback
Operative
Indications
For failure of non-operative treatment
- patella tilt with lateral patella pain
- recurrent instability
Options
Depends on pathology
- assessment and investigation critical for deciding treatment
1. Isolated Patella tilt
Indications
- clinical and xray patella tilt
- no instability / malalignment
- excessive lateral pressure syndrome
Techniques
1. Arthroscopic lateral release
- knee in extension
- camera in AM portal
- hook diathermy in AL portal
- 5mm lateral to patella / 1cm superior to patella / down to anterolateral portal
- release retinaculum under vision
- must ensure SLGA coagulated / can visualise
- let down tourniquet at end of procedure
- ensure can evert patella 90o at end
2. Smiley knife release
- arthroscopy
- insert in AL portal
- divide retinaculum by feel
Post op
- drain 24 hours
- protect for 1 week
Results
McGinty et al Clin Orthop 1981
- 32/39 G/E results
Complications
A. Haemarthrosis
- can be major / problematic
- insert drain, splint and minimise activities first few weeks
- manage via early washout / insertion drain
B. Medial subluxation
- extending release too far into VL
- performing lateral release when have ligamentous laxity and instability
Patella subluxation / recurrent dislocation
Issues
- must have had long non operative period
- treatment depends on cause
- different treatment options in skeletally immature
Treatment algorithm
1. Recurrent subluxation + normal alignment (TTTG < 15 - 20)
- lateral release (only do if patella tilt / tight laterally or will dislocate medially)
- MPFL reconstruction / VMO advancement / medial reefing
2. Recurrent subluxation + malalignment (TTTG > 20)
- above + add TTT (tibial tuberosity transfer)
- Roux-Goldthwaite instead of TTT if physis open
3. Above + Excessive femoral anteversion
- consider DRFO (derotation femoral osteotomy)
4. Above + Excessive external tibial torsion (> 45 degrees)
- consider tibial derotation osteotomy
5. Trochlea dysplasia
- trochleoplasty
5. Patella alta
- distalise TT
Surgical Algorithm
1. Perform lateral release
- rarely needed
- most patients are ligamentous lax / hypermobile patella
- may be needed in chronic setting or if congenital
2. Perform TTT (if TTTG > 20)
- incision over TTT
- medialise at least 1 cm
- ensure some element of Fulkerson / anteriorise
- can distalise if patella alta
- secure with screws (2 x small fragment usually sufficient)
- reassess stability
3. MPFL reconstruction (with TTT, or if TTTG < 20)
- acts as checkrein to lateral displacement
- usually harvest hamstring autograft
- medial incision
- beware overtightening (will give pain) / patella fracture (drill holes in patella)
- reassess for stability
4. Lateral Trochlea Elevation
- still unstable after above operations
- small lateral incision
- beware fracturing lateral femoral condyle
- need to be able to take bone graft from iliac crest
Tibial Tuberosity Transfer
Contraindication
Open Physis
Theory
A. Medial displacement corrects Q angle
- must correct Q angle < 10o
- at least 1 cm
B. Anterior displacement unloads PJF
C. Distal displacement corrects patella alta
Types
Hauser distalisation
- for patella alta
- operation in isolation had disappointing results
- get posteriorisation tubercle and increased forces across PFJ
Fulkerson
- anteromedial transfer
- osteotomy lateral to medial
- direct osteotomy anteriorly
- unloads PJF
Elmslie-Trillat
- medialisation
- no posterisation
Surgical Technique of TTT
Technique 1
- direct osteotomy with oscillating saw lateral to medial
- initial incision slightly lateral of midline over Tibial tuberosity
- lateral incision in periosteum
- osteotomy 1.5 cm deep, 6 cm long
- angle osteotomy 45 degrees / use k wires to guide
- attempt to leave medial and distal periosteum intact for stability
- minimum medial transfer is 1 cm, usually 18 - 20 mm
- fix with two screws
- if want to distalise for patella alta, performing distal step cut, and distalise 6 mm
- never make transfer posterior
Technique 2
- use reciprocating saw
- cut down from the top, behind the PT
- 4 cm long
- leave intact distally
- use 3.5 mm drill to perforate distal attachment laterally
- can then swing the TT medially on distal / medial pivot
- secure with singe 4.5 mm bi-cortical lag screw
Consider patella cartilage
- combine with cartilage procedure
- microfracture / MACI / de novo
Results
Caton and Dejour Int Orthop 2010
- TTT in 61 knees
- 76.8% stability
Cossey et al Knee 2005
- 19 patients with TTT / MPFL reconstruction
- no redislocations
Skeletally Immature
Roux-Goldthwaite
Indications
- skeletally immature with malalignment
Technique
- lateral half PT rerouted
- under medial PT
- stitched to MCL / sartorius
Technique Modification
Take medial half patella tendon
- suture to MCL
PT transfer + MPFL
- incision midway between PT and MCL
- identify patella tendon
- divide in two
- sharp dissection of medial half off bone
- dissect medially
- divide fascia and retinaculum to expose MCL
- suture to MCL with 2.0 non absorbable sutures
- through same incision can harvest hamstrings for MPFL reconstruction
Results
Fondren et al JBJS Am 1985
- 43/47 G/E results
Medial Operations
1. MPFL reconstruction
Indication
- patient with history initial traumatic dislocation
- also indicated in patient with laxity to act as a check rein
Grafts
1. Y Graft
- double ST autograft into Y
2. Single limb free semitendinosus autograft
- limb to patella via endobutton
Schottle's Point
Schottle AJSM 2007
- cadaveric study
- 1 mm anterior posterior cortex
- 2 mm distal to MFC origin
- above blumensaats
Technique
A. Patella fixation
- incision along medial patella
- 2 drill holes in patella
- attach ends of graft, pass into patella, secure with anchor of choice
- pass graft superficial to capsule
B. Femoral fixaiton
- best to use II to find point
- stem between medial epicondyle and adductor tubercle
- Schottle's Point
- drill wire across femur, drill hole for fixation screw
- pass doubled graft into tunnel
- set at 30o flexion
- ensure doesn't dislocation laterallly
- don't overtighten
- secure with screw
Xrays 1
Tunnel too anterior / tight in flexion
Xray 2
Finding Schottles Point
Results
Nomura et al J Arthroscopy 2006
- recurrent dislocation, no malalignment
- 83% G/E results
- no redislocation at 2 year follow up
Howells JBJB Br 2012
- 211 procedures in 193 knees
- all TTTG < 18
- most moderate trochlea dysplasia
- no redislocations at 16 months
Shah et al AJSM 2012
- Systematic review MPFL
- 26% complication rate
- 4/629 (0.6%) fractures
- 26/629 (4%) stiffness
- 23/629 (3.7%) failure rate
2. Medial imbrication
Indications
- MPFL needs to be intact or won't work
- laxity / stretched / attenuated structures
Technique
Insall procedure
- medial flap sutured 1 cm over lateral flap
Results
Scuderi et al JBJS Am 1988
- combined with lateral release
- normal and abnormal Q angle
- 42/52 G/E 81%
Barber et al Arthroscopy 2008
- TTT + medical plication in 34 knees
- 91.4% stability
Zhao AJSM 2012
- RCT MPFL v medial plicaiton
- 100 patients
- recurrent instability 7% v 16%
- better Kujala scores in MPFL
3. VMO advancement
Madigan procedure
- VMO detached and advanced laterally and distally
- sutured to fascia on patella
Trochleoplasty
Indication
- trochlea dysplasia
- if after MPFL and TTT the patella still unstable at end of case
Techniques
1. Dejour Trochleoplasty
- lift up anterior aspect femoral condyles
- deepening of trochlea
- replacement of LFC
- risk of chondral fracture / AVN / non union / displacement
Utting et al JBJS Br 2008
- 50/54 92%
- combined with other procedures as required
2. Elevate lateral edge of lateral femoral condyle
- insert osteotome
- gently elevate without fracturing chondral surface
- insert 2 - 3 mm of iliac crest bone graft
- no need for stabilisation
Results
Nelitz et al AJSM 2013
- trochleoplasty + MPFL in 26 knees
- no redislocation, no complications
- 96% statisfied
Tibial Derotation Osteotomy
Indication
- excessive external tibial torsion > 45 degrees
- 1 / 5000 people
Results
Drexler et al KSSTA 2013
- good outcome for 15/17 knees
Chronic Dislocation
Chronic / congenital
- patella subluxed out of joint
- patella alta
- treat with identical principles
- lateral release / TTT / MPFL reconstruction