Tibiofibular joints

Articular surfaces

The superior tibiofibular joint is an articulation between articular facets on the proximal ends of the tibia and fibula respectively. The tibial articular facet is located on the lateral tibial condyle and it faces posteriorly, inferiorly and laterally.

The oval fibular articular facet is found on the head of fibula, facing anteriorly, superiorly and medially. The surfaces are flat and covered with hyaline cartilage, classifying this joint as a plane synovial joint.

Ligaments and joint capsule

Being a plane joint, there is no bony stability within the proximal tibiofibular articulation. Instead, stability is provided by the strong fibrous capsule and a pair of ligaments.

The fibrous capsule is attached to the margins of the articular surfaces. The internal surface of the capsule is lined by a synovial membrane which is sometimes continuous with that of the knee joint. In this case, the distal prolongation of the knee joint cavity called the popliteal bursa communicates with the tibiofibular joint through an aperture on the upper part of its capsule.

The superior tibiofibular joint is reinforced by the anterior and posterior tibiofibular ligaments.

• The anterior ligament of fibular head is short, wide and thick. It traverses the anterior aspect of the joint. The ligament consists of two to three fascicles that arise from the anterior aspect of the fibular head. The fascicles then take an oblique, superomedial, course and attach to the anterior surface of the lateral tibial condyle.
• The posterior ligament of fibular head is also short and wide in structure. It is formed by a single band which arises from the posterior surface of the fibular head, passes obliquely in a superomedially direction, to attach to the posterior aspect of the lateral tibial condyle. The posterior surface of the ligament is crossed by the tendon of the popliteus muscle.

Innervation

The superior tibiofibular joint is innervated by the common fibular nerve (recurrent branch) and the nerve to popliteus muscle.

The former is a branch of the sciatic nerve, while the latter stems from the tibial nerve.

Blood supply

Blood supply to the superior tibiofibular joint comes from two branches of the anterior tibial artery; anterior and posterior tibial recurrent arteries.

Movements

As a plane synovial joint, the superior tibiofibular joint allows slight gliding movements. More specifically, this joint allows the accessory movement of anteroposterior gliding of the fibula against the tibia. These movements occur in a superior-inferior direction, and range to only a few degrees. They are not produced actively by any muscles, but rather follow the movements of the inferior tibiofibular and ankle (talocrural) joints. 

Articular surfaces

The inferior tibiofibular joint is a fibrous joint, precisely a syndesmosis. The articular surfaces of this joint are the triangular convex surface on the medial aspect of the distal end of the fibula and the reciprocally concave fibular notch on the distal end of tibia.

Ligaments and joint capsule

As a fibrous joint, the inferior tibiofibular joint does not have an articular capsule, or its own synovial membrane. Instead, the synovial membrane of the talocrural joint projects approximately 4 millimeters superiorly to enter this joint.

The articular surfaces of the distal tibiofibular joint are held together by the interosseous ligament, and the anterior, posterior and transverse tibiofibular ligaments.

• The interosseous tibiofibular ligament connects the facing surfaces of the bones and it is continuous with the interosseous membrane of the leg. It strongly connects the bones and it is the principal stabilizer of this joint.
• The anterior and posterior tibiofibular ligaments extend between the anterior and posterior surfaces of the tibia and fibula, respectively. They both course inferiorly and laterally, with the posterior ligament being thicker and wider than the anterior. These ligaments cover the trochlear surface of talus interchangeably during the foot movements; the anterior during dorsiflexion and the posterior during the plantar flexion of the foot.
• The inferior transverse ligament is found deep to the posterior tibiofibular ligament. It is considered by many authors to be the deep part of the posterior tibiofibular ligament. It is made of yellow ligamentous fibers which contain much more elastic fibers than the white ligaments which are seen in most of the body’s joints. This feature makes this ligament far more stretchy than other ligaments of this joint.

Innervation

Branches of the deep fibular and sural nerves innervate the inferior tibiofibular joint.

Blood supply

The inferior tibiofibular joint is vascularized by the perforating branch of fibular artery and by the lateral malleolar branches of both the anterior and posterior tibial arteries.

Movements

Although heavily stabilized by the strong set of ligaments, the inferior tibiofibular joint allows discrete superior-inferior gliding of the bones and stretching of the interval between them. The purpose of these movements is to accommodate motion of the talocrural joint. 

During dorsiflexion of the foot, the fibula externally rotates and consequentially slightly widens the interval between the tibia and fibula at the inferior tibiofibular joint. The fibula is also translated superiorly in this movement, which is followed by a superior gliding movement within both the inferior and superior tibiofibular joints. Conversely, plantarflexion of the foot is followed by inferior gliding of the fibula at both tibiofibular joints, as well as narrowing the interval between the tibia and fibula at the inferior tibiofibular joint. 

The capsular pattern of the tibiofibular joint is described as pain when the joint is stressed. The joint is in a close packed position at maximum dorsiflexion of the foot, while it is loosely packed in plantar flexion. The accessory movement within this joint is the anteroposterior gliding of the fibula against the tibia.

Test your knowledge on the tibia and fibula with this quiz.