Patellar Stabilization

Patellar instability

Patellar instability may be physiological (commonly seen in children with generalised hypermobility) or pathological, most often following trauma.

Traumatic patellar dislocation

A significant injury can cause the kneecap (patella) to dislocate laterally (outwards).
In some children, particularly after a first-time dislocation, the patella may remain displaced and require reduction under anaesthesia.

Initial management

• Reduction of the patella
• Immobilisation in a knee splint
• Structured physiotherapy rehabilitation

Most children regain stability after appropriate treatment.

Recurrent patellar instability

A minority of patients develop repeated episodes of the kneecap “giving way”.
The causes are broadly divided into internal (structural) and external (alignment-related) factors.

Internal causes

• Tear of the medial patellofemoral ligament (MPFL) — MRI diagnostic
• MPFL laxity without complete tear (positive apprehension sign)
• Trochlear dysplasia (shallow groove in the distal femur)

External causes

• Out-toeing gait
• Genu valgum (knock knees)
• Increased Q-angle due to rotational malalignment of the hips/femur
• Flat feet affecting limb alignment

Treatment

First-time dislocation

Usually managed non-operatively:

• Splint or brace
• Physiotherapy focusing on quadriceps strengthening and control

Recurrent instability

Surgical stabilisation is typically required.

Common procedure

• Arthroscopic (keyhole-assisted) MPFL reconstruction

Additional procedures (when required)

• Correction of femoral rotational deformity
• Correction of genu valgum
• Foot alignment procedures for flat feet

Treatment is individualised to address the underlying cause to restore stability and prevent cartilage damage in the knee.