Treatment of Patellar Subluxation vs. Patellar Dislocation
For first-time patellar dislocation without osteochondral fracture, initiate nonoperative treatment with physical therapy starting within the first month, allowing return to sport at 2-4 months with bracing; surgical intervention is reserved for recurrent instability after 6 months of failed conservative management or when a concomitant osteochondral fracture is present. 1
Initial Management Distinction
The treatment approach differs primarily based on whether there is a complete dislocation versus subluxation, and whether this is a first-time or recurrent event:
First-Time Patellar Dislocation (Complete)
Nonoperative management is indicated in 99% of cases when there is no osteochondral fracture 1. This consensus reflects that randomized trials show no significant difference between surgical and conservative treatment after first-time dislocation in children, adolescents, and adults 2.
Initial imaging protocol:
- Obtain knee radiographs immediately (99% consensus) 1
- MRI should be standard practice to detect MPFL rupture, osteochondral lesions, and risk factors for redislocation 3
Conservative treatment protocol:
- Immobilization phase (0-4 weeks): Use rigid strapping tape to tilt and center the patella in the trochlea, shortening medial soft tissues to enhance healing 4. Cryotherapy and compression manage effusion while early ROM exercises prevent stiffness 5
- Physical therapy initiation: Start within the first month post-injury (99% consensus) 1
- Intermediate phase (4-6 weeks): Focus on strengthening dynamic knee stabilizers with progressive open- and closed-chain exercises 5
- Late phase (6-8 weeks): Restore full strength through sports-specific drills and higher-intensity exercises 5
- Return to sport: 2-4 months post-injury (68% consensus) with bracing (75% consensus) 1
- Follow-up: As needed basis (75% consensus) 1
Patellar Subluxation (Recurrent or Chronic)
For recurrent subluxation or subacute phase (after 6 weeks), apply firm tape across the vastus lateralis to minimize lateral patellar displacement while facilitating vastus medialis oblique contraction 4. This differs from acute dislocation taping by focusing on dynamic control rather than rigid immobilization.
Surgical Indications
Surgery is indicated in three specific scenarios:
First-time dislocation WITH osteochondral fracture: Patellar stabilization should be considered (81.5% consensus) 1. The presence of a 2cm or larger osteochondral fragment warrants surgical intervention 1
Failed conservative management: If patellar subluxation episodes occur after 6 months of nonoperative treatment, surgical intervention is recommended (84% consensus) 1
Recurrent dislocations: Up to 35% of individuals experience recurrent dislocations after nonoperative treatment 6. MPFL reconstruction is the most effective surgical treatment, yielding a redislocation rate of only 5% 3
Evidence-Based Rehabilitation Components
The rehabilitation program should incorporate:
Exercise therapy priorities:
- Combined hip and knee exercises are superior to knee exercises alone for reducing pain and improving function in short, medium, and long term 7
- Knee-targeted exercise therapy with supportive interventions tailored to patient needs 8
- Education should underpin all interventions 8
Adjunctive interventions with evidence:
- Prefabricated foot orthoses for short-term pain relief 7
- Patellar taping/bracing provides immediate stability and relief, promoting muscle preservation 5
- Combined interventions (exercise plus foot orthoses, patellar taping, or manual therapy) reduce pain in short and medium term 7
Not recommended:
- Patellofemoral, knee, or lumbar mobilizations in isolation 7
- Electrophysical agents 7
- Lateral release (can increase patellar instability) 3
Critical Risk Factors Requiring Assessment
Evaluate these anatomical abnormalities that increase redislocation risk:
- Trochlear dysplasia
- Patella alta
- Increased tibial tuberosity-trochlear groove (TT-TG) distance
- Torsional abnormalities
- Vastus medialis obliquus weakness
- MPFL rupture 2, 3
Common Pitfalls to Avoid
Immobilization without early ROM: Avoid prolonged immobilization as systematic reviews show no difference in redislocation rates between partial and full weightbearing protocols 5
Premature return to sport: Ensure complete healing, neuromuscular training, core strength, and psychological readiness before clearance 5. Use functional assessments like Y-balance and triple-hop tests to evaluate limb symmetry 5
Surgery for first-time dislocation without osteochondral injury: While surgery reduces redislocation rates, it does not clearly produce greater functional outcomes than conservative management and is more expensive and invasive 4
Ignoring MPFL pathology: The MPFL is the most significant passive stabilizer of the patella and ruptures in 90% of dislocations 2. When surgery is needed, MPFL reconstruction is the procedure of choice 3