Presence of a fluid filled synovial cavity between the articulating surfaces of the two bones is not required in

Fibrous and cartilaginous joints do not have a synovial cavity between the articulating surfaces, unlike synovial joints.

• Fibrous Joints: In fibrous joints, the bones are held together by dense regular connective tissue, and there is little to no movement between the bones. These joints lack a synovial cavity. Examples of fibrous joints include sutures between skull bones and syndesmoses, such as the connection between the tibia and fibula bones in the lower leg.
• Cartilaginous Joints: Cartilaginous joints, as the name suggests, are connected by cartilage. They also lack a synovial cavity. There are two types of cartilaginous joints: synchondroses and symphyses. Synchondroses are temporary cartilaginous joints found in the growth plates of growing bones, while symphyses are more permanent and found in locations like the intervertebral discs and the pubic symphysis.

In contrast, synovial joints, like the knee and shoulder joints, have a fluid-filled synovial cavity between the articulating surfaces of the bones. This cavity is lined with a synovial membrane that secretes synovial fluid, which lubricates the joint and reduces friction during movement.