Incidence
10%
Requirements
70o swing phase
80o climb up stairs
90o climb down stairs + sit down in chair
100o low chair
NHx
Stiffness usually subsides at 6-8/52
- generally improves out to 3/12
- slow improvement for up to next 9/12
Preoperative flexion is predictive of outcome
- <75° preoperative gain average 16°
- 95o preoperative lose average 6°
Causes
1. Post-op pain
Number one cause
- Causes quads and HS guarding
- making passive flexion and extension difficult to perform
- need adequate analgesia
- CPM not shown to shorten hospital stay or increase ROM
Analgesia
Continuous epidural infusion best, but prohibits anticoagulation
Combination of
- regular paracetamol
- femoral nerve catheter
- PCA / slow release opiates (oxycontin)
NSAIDS
- risk of renal impairment in elderly
- even COX 2
2. Infection
Always consider with loss of ROM
3. Surgical Technique
FFD
- may indicate too little bone resection off Distal Femur
Lack of Flexion
1. Anterior tibial Slope / previous HTO
2. Tight PCL if CR
3. Use of oversized femoral component
- narrow flexion gap / overstuffs PFJ
4. Posterior osteophytes / tight posterior capsule
Poor Ligament Balancing
- important cause
- result in flex and ext problems
Component Malrotation
- internal rotation of tibia / femoral component
- check with CT
PFJ dysfunction
Maltracking
Non resurfacing and pain
Joint line elevation - patella baja
4. Poor Patient Motivation
5. Arthrofibrosis
Management
A. Exclude infection
B. Aggressive physiotherapy and adequate analgesia
C. MUA
Indications
- ROM < 90o at 6/52
- doesn't work for FFD
- FFD will usually resolve with time
Technique
- epidural catheter
- aspirate for infection
- manipulate
- post operative epidural and CPM
Risks
- supracondylar fracture
- patella tendon avulsion
- quadriceps tendon tears
- hematoma formation
- wound dehiscence
Technique MUA
- don't lever down on tibia
- hold femur
- bounce tibia up and down
- passive rather than active MUA
- be patient
Results
- variable in literature
- may be done up to 3/12
D. Debridement
Open or Arthroscopic
- clear suprapatellar pouch / medial and lateral gutters
Judet quadricepsplasty
- above +
- release / removal of rectus femoris
- mobilisation of quadriceps from femur
E. Revision
If mechanical problem with implant
- debride all scar tissue
- PS implant
- consider full revision if component malrotation
- resurface patella