What is femur and femoral neck

Hip is a ball and socket joint where upper leg meets the pelvis. Femur is the longest, strongest bone of the body and is also called “thighbone”. At the top of the femur is the femoral head. This is the ball that sits in the socket. Just below the femoral head is the femoral neck. Because femur is a weight bearing structure and femoral neck is the narrow part, stress fractures occur in this area. The importance of femoral neck stress fractures is that if detected early, and the injury is un-displaced, management and outcome have much higher success rates, when compared to displaced fractures.

HOW IT OCCURS

When bone is subjected to repetitive daily subthreshold loading, micro-cracks may occur within cement lines. The normal re-modelling a process repairs these cracks.

However, if the bone continues to be subjected to high stresses, then crack propagation occurs. If crack progression is faster than the repair, it will become a stress fracture. Stress fractures occur when normal bone is exposed to abnormal stress.

 

RISK FACTORS

They are seen in professional athletes and in military personnel.

Activities like long distance running, abrupt increase in training without adequate rest may predispose to stress fractures.

Women are at increased risk of stress fractures because of narrower bones and lower bone mineral density, especially in postmenopausal women with osteoporosis.

Calcium deficiency and vitamin D deficiency.

Smokers are prone for more these fractures

NSAIDs use, overweight, muscle weakness or imbalance predispose to stress fractures.

PRESENTATION

Most common symptom is gradual onset hip or groin pain that is aggravated by activity and weight bearing and ceases with rest.

Patients often notice a recent increase in intensity or duration of exercise, such as preparation for a marathon or a sports event. Initially, pain is noted late in an activity, eventually pain is noted at rest and at night.

On examination pain on extremes of hip range of motion, especially with internal rotation. Tenderness over front of thigh and the inguinal area. Pain can be increased by doing straight leg raise test.

DIAGNOSIS

X-RAY can be useful if a stress fractures are seen, then further imaging is rarely necessary.

However, x-ray may be false negative for up to 3 months after symptoms onset

Scintigrams (isolated bone scans) are very sensitive, but not specific.

MRI is both specific and sensitive for a stress fracture and involves no radiation exposure.

TREATMENT

There are nonoperative and operative treatment plans are available.

Nonoperative treatment includes non weight bearing, crutches and activity restriction. Majority of stress fractures can be successfully treated non-operatively by avoiding stress activity.

Operative techniques include percutaneous screw fixation. Operative techniques are used for cases of delayed union or failed non-operative treatment.

 

 

Frequently Asked Questions 

Regardless of the grading, all patients with a FNSF should cease all impact activities (running and jumping sports) for a minimum of 6 weeks. If there is any pain with walking, standing or the development of night pain, crutches will be required for a minimum of 3 weeks.
Bone generally takes 6-8 weeks to heal and this is the period of time where crutches and non-weight bearing are required. A period of progressive partial weight bearing (still with crutches) and can follow this period hopefully crutches can be discarded at approx. 12 weeks.
Can you walk with a hairline hip fracture?
You may be unable to walk. Your skin around the injury may also swell, get red or bruise. Some people with hip fractures can still walk. They might just complain of vague pain in their hips, butt, thighs, groin or back.
Does a hairline hip fracture require surgery?
A hip fracture is a break in the upper part of the thigh bone (femur), which is the bone that fits into the socket of the hip joint. Severe fractures are usually treated with surgery. Stress fractures, which are tiny hairline cracks in the bone, may or may not require surgery.
Can you stress fracture your femur?
The highest incidence of femoral stress fracture occurs at the femoral neck, where the top of the thighbone joins the hip and pelvis. Deep thigh or groin pain, particularly while doing activity, is the most common and noticeable symptom of femoral stress fracture.
Can a stress fracture turn into a break?
The real risk of a stress fracture is that it could become a full break, increasing the severity of your injury and the intensity of your pain.