THE KNEE

This blog will focus on the general anatomy of the knee joint, the muscles surrounding the area, and possible problems that arise in the clinic.

The knee joint is also known as the Tibiofemoral joint. Above the knee, there is the femur, and below is the Tibia. Lateral (to the outer side) to the Tibia is the Fibula, which supports the Tibia. The patella (commonly known as the kneecap) is connected to the Tibia by the patellar ligament. Beneath the patella is the Infrapatellar fat pad. At the end of each bone (Femur and Tibia), there is a rubbery surface that acts as a shock absorber and allows movement; this material is called the Articular Cartilage.

The meniscus is known as the knee cartilage, which helps spread the body's weight.

These small "ropes" around the knee are called ligaments. The ACL (Anterior cruciate ligament) and the PCL (Posterior cruciate ligament) are within the joint. The ACL stops the forward motion of the Tibia, and the PCL prevents the backward movement of the Tibia.

The MCL (Medial collateral ligament) (inner side of the knee) connects the femur to the Tibia, which resists valgus force. The LCL (Lateral collateral ligament) (outer side of the knee) resists varus force.

Healthy, functional muscles are essential for everyday activities. At the front of the leg, there are the muscles that allow you to straighten your knee.

Four quadriceps muscles are:

➢ Rectus Femoris

➢ Vastus Medialis

➢ Vastus Lateralis

➢ Vastus Intermedialis

The muscles behind your thigh are called the Hamstring muscles.

The group consists of the following:

➢ Bicep Femoris

➢ Semitendinosus

➢ Semimembranosus

If you place your hand on the side of your thigh, you can find the Iliotibial band. The muscles located on the inner thigh are known as the adductors. The Tricep Surea is the medical term for calve muscles. In the future, the lower limb muscles will be discussed.

Nerves:

The essential nerves around the knees are the tibial nerve and the common peroneal nerve, which supply sensation and muscle control. The majority know of the Sciatica nerve, the Sciatica nerve splits (at the back, above the knee) into the tibial nerve and the common peroneal nerve.

Blood Supply:

Keeping it simple and to the point, the popliteal artery (has come from the femoral artery) and the popliteal vein are the most significant blood supply to the leg and foot.

Common/ Potential problems:

➢ ACL Injury

➢ PCL Injury

➢ MCL Sprain

➢ LCL Sprain

➢ Meniscus Tear

➢ Patella dislocation

➢ Fat Pad Syndrome

➢ Patellofemoral Pain Syndrome (Runner's Knee)

➢ Osgood Schlatter's

➢ Knee Osteoarthritis

➢ Tendinopathy

➢ Popliteus Tendinitis

➢ ITB syndrome

➢ Muscle Strain

➢ DOMS (Delayed Onset Muscle Soreness)

➢ Hamstring Strain

Case Study: Post Meniscus (Cartilage) Surgery

During the surgery: the lateral meniscus was "cleaned up and smoothed out", and the medial was not touched during the operation. The patient presented with pain medially and posterior to the knee, some pain located at the pes ansinerus site, pinch felt and locking sensation when extending the leg. On palpation, the popliteus is tense, and the hamstrings are taut and short. For clinical reasoning, we want to know why the popliteus is locking. Looking back at the anatomy of the knee, can you understand why?

The insertion of two of the hamstring muscles in detail, they insert to the proximal Tibia, pes anserinus (Semitendinosus) and posterior medial condyle of the Tibia (Semimembranosus); from extensive research, they also slightly insert to the medial part of the meniscus/cartilage. The hamstrings are short and tense, the cartilage on one side of the meniscus was cleaned, and the opposite was not touched. The hamstrings may pull the cartilage, which may lead to a pinch.

Ripon Physio Co.

Orla O Regan