The hip is the joint that allows the femur to move in relation to the pelvis. It is a spherical joint, capable of a wide excursion but, at the same time it is also very stable thanks to the solid interlocking of the femoral head in the acetabular cavity (or cup) of the pelvis.
Like all the sustaining joints, carrying the body weight, it is subject to extremely high pressure every time it is used. This makes it essential to maintain a perfectly spherical shape, an appropriate cartilage coating (often in some places over 5 mm), and generous lubrication. These are some of the characteristics of a normal hip.
When this delicate balance is broken, the hip becomes painful and stiff, leading almost immediately to claudication and a limitation of movement.
What are the symptoms?
The symptoms of an unhealthy” hip will be essentially three: pain, stiffness and lameness, of various intensity depending on the pathology and the patient.
The pain that originates from the hip, also called coxalgia, is typically localized at the groin, sometimes the buttock, it could also irradiate along the thigh down to the knee. Sometimes – it is good to remember – knee pain is the only disorder caused by a hip disease.
Load and movement trigger joint pain, while palpation in the sore regions normally is not painful since he joints is very deep and cannot̀ be reached, even though sometimes a particularly energetic compression is performed. Coxalgia in the adult can be the alarm bell of coxarthrosis (i.e. hip osteoarthritis), a femoral-acetabular problem, or of a cephalic necrosis.
When palpation allows to identify points of soreness (typically at bony bumps such as the large trochanter), the hip may not be the problem, while the surrounding soft tissues (tendinitis and bursitis) might be. Finally, the high posterior pain, between the buttock and the lumbar area, is more often the sign of a pathology concerning the spine or sacroiliac joint, rather than the hip.
The rigidity, or the limitation of movement, is a typical and rather disabling disorder. Since the first movement that is compromised is bending, the hip condition can be so invalidating to make it difficult, autonomously, to put on socks and shoes. In the most̀ advanced stages, a stiffness in extra rotation can appear, which causes the patient to walk with the tip of his foot pointing "outside”.
Lameness is present whenever you feel a pain in walking. This does not have to be a cause of concern, since it is just a protective mechanism that our body uses to minimize painful issues. Although there are many variants of this clinical sign, the most common ̀ is the so-called "antalgic gait", caused by the attempt to shorten the support on the sick limb (escape from the support).
The rhythm of our walking step thus becomes "asymmetric”, as the emphasis is placed more on one side thar that being equally divided between left and right.
What investigations are useful for diagnosis?
The frontal X-ray of the pelvis associated with the axial x-ray of the sore hip is the first and often only instrumental examination that can help the specialist to formulate the diagnosis.
It is important that the frontal projection is of the entire pelvis, and not just of the hip, to allow a comparative judgment and to ensure the optimal focus of X-rays. If your GP suspects you have a hip disease, arriving at the specialist examination with an X-ray alreadỳ properly performed will allow to speed up treatment and therefore healing time.
Further investigations, such as CT scans, MAGNETIC resonance imaging and ultrasound are expensive and, as in the case of CT scans, can result in considerable irradiation. Their prescription should be left to the orthopedist if felt appropriate.