[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/) › Lateral retinaculum

[Muscular system](https://durgical.com/en/anatomy/system/muscular-system/) · [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/)

# Lateral retinaculum

The lateral retinaculum is a strong fibrous sheet on the outer side of the kneecap; it helps hold the kneecap in its groove.

Official name: Lateral patellar retinaculum

[See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=lower_limb&select=retinaculum_lat&side=r)

Opens in the Durgical app, no sign-up needed.

## What it is

A fibrous sheet on the outer side of the kneecap.

## What it does

Helps keep the kneecap centred; if too tight it can pull the kneecap outward.

## Key points

- Thicker and stronger than the [medial retinaculum](https://durgical.com/en/anatomy/medial-patellar-retinaculum/), in two layers: a superficial oblique layer from the IT band (iliotibial band) and a deep transverse layer
- A tight lateral retinaculum tilts the [patella](https://durgical.com/en/anatomy/patella/) and overloads its lateral facet (excessive lateral pressure syndrome)
- Lateral release eases a tight retinaculum; overdone, it can cause medial patellar instability

## Key facts

**Attaches**
Expansions of vastus lateralis and iliotibial tract: lateral patellar border to lateral tibial condyle

**Function**
Lateral patellar stabilizer; when tight it tilts the patella laterally

**Tight in**
Knee flexion; medial glide of patella

## Relations

**Superficial**
[IT band](https://durgical.com/en/anatomy/iliotibial-tract/) fibres (superficial oblique retinaculum) and [skin](https://durgical.com/en/anatomy/skin/)

**Deep**
[Joint capsule](https://durgical.com/en/anatomy/articular-capsule-of-knee-joint/) and synovium over the lateral femoral condyle and the lateral trochlea

**Above**
[Vastus lateralis](https://durgical.com/en/anatomy/vastus-lateralis-muscle/), whose aponeurosis forms part of it

**Below**
Lateral border of the [patellar tendon](https://durgical.com/en/anatomy/patellar-ligament/) and the lateral tibial condyle near Gerdy tubercle

## How to find it

With the knee straight and the quadriceps relaxed, it is the firm sheet felt between the outer edge of the patella and the IT band; a tight one resists lifting the lateral edge of the patella and pushing the patella medially. Tenderness along the lateral facet goes with lateral overload.

## Examination

- Patellar tilt test: knee straight, the lateral edge of the patella is lifted; failure to raise it to horizontal means a tight lateral retinaculum
- Medial patellar glide: movement of a quarter of the patellar width or less suggests tight lateral restraints

## On imaging

Axial (skyline) X-ray, CT or MRI shows patellar tilt, lateral facet narrowing and, after a dislocation, the retinacular tear. A lateral release is visible on MRI as a gap in the retinaculum.

## Clinical notes

- Lateral release can be combined with medial stabilization; on its own it does not treat lateral instability
- Iatrogenic medial patellar instability after an excessive release is a classic complication

## Related conditions

- [Patellar Dislocation](https://durgical.com/en/conditions/patellar-dislocation/)
- [Patellar fracture](https://durgical.com/en/conditions/patellar-fracture/)

## Test yourself

Think of the answer, then tap the question to see it.

## How does the lateral retinaculum compare with the medial retinaculum?

It is thicker and stronger, in two layers: a superficial oblique layer from the IT band and a deep transverse layer.

## What does a tight lateral retinaculum cause?

It tilts the patella and overloads its lateral facet (excessive lateral pressure syndrome).

## What is the classic complication of an excessive lateral release?

Iatrogenic medial patellar instability.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/anatomy/lateral-patellar-retinaculum/)

Educational information, not medical advice. For any symptom, see a health professional.

## Its names

**Official Latin (TA2)**
retinaculum laterale patellae TA2 2624

**Official Spanish (DeCS)**
Retináculo lateral de la rótula

**English (TA2)**
Lateral patellar retinaculum

**Also called**
retinaculum fibulare patellae

## Related

- [Patella](https://durgical.com/en/anatomy/patella/)
- [Femur](https://durgical.com/en/anatomy/femur/)

Sources: Terminologia Anatomica (TA2); [Anatomy, Bony Pelvis and Lower Limb, Knee Patella](https://www.ncbi.nlm.nih.gov/books/NBK519534/); Anatomy of the Human Body (20th ed.): Surface Anatomy of the Lower Extremity (Lea & Febiger (Gray's Anatomy, 1918), 1918) · adapted, Public domain.

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/anatomy/lateral-patellar-retinaculum/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/lateral-patellar-retinaculum/