Brian P. Jacob, David C. Chen, Bruce Ramshaw, Shirin Towfigh (eds.) - The SAGES Manual of Groin Pain-Springer International Publishing (2016)

8. Groin Pain Etiology: Hip- Referred Groin Pain
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destructive enzymes are released by immune cells in response to the
infection, thereby causing irreversible damage to articular cartilage.
Failure to intervene early in the process leads to cartilage destruction and
may lead to chronic osteomyelitis if the infection spreads into the
adjacent bone. As such, should cell counts be diagnostic or cultures be
positive, urgent irrigation and debridement of the joint, either
arthroscopically or open, should be performed .
Stress Fracture and Pathological Fracture
Presentation Stress fractures are most common among running
athletes. Typically, patients present with pain of insidious onset, often
associated with increases or changes in training. The pain is worse with
weight bearing and with increased activity. Stress fractures are more
common among female athletes, especially those with low body weight
and amenorrhea. A stress fracture forms when the body is unable to
remodel at the rate necessary to deal with the increased repetitive stresses
imposed on it. These can occur in the sacrum, pubic rami, and femoral
neck. Although only 10 % of stress fractures occur at the femoral neck,
they require immediate attention. There is a risk of fracture displacement
which may lead to complications such as a vascular necrosis (AVN)
[ 10 ]. Another subset of patients who may present with groin or thigh pain
are elderly patients with known osteoporosis who have been on
bisphosphonate therapy for several years. These patients, ironically, may
also have stress fractures. Bisphosphonates have become extremely
common for the treatment of osteoporosis, as they have been shown to
decrease the rate of hip fracture by up to 51 % in some series [ 11 ].
Bisphosphonates function by incorporating into the mineral content of
bone, consequently decreasing osteoclastic activity. However, due to the
coupling of osteoclastic (bone resorbing) and osteoblastic (bone building)
cell activities, this leads to the decreased ability of the bone to remodel.
Whereas this is helpful in decreasing the rate of bone resorption in
patients with osteoporosis, the reduced rate of bone turnover does not
allow for adequate remodeling of bones with high stresses. The
subtrochanteric femur is particularly prone to this process. These patients
present with thigh or groin pain of insidious onset that is worse with
activity and on rising from a seated position. Patients with this process
are prone to fractures of the subtrochanteric femur with very minimal
trauma, often as little as a twisting moment while walking.