HIP MICROINSTABILITY

DESCRIPTION

This is a situation where the upper thigh bone (femoral head) moves excessively in relation to its normal position in the center of the socket (acetabulum). We have shown that the femoral head does normally move relative to the acetabulum. However, in some people, that motion is excessive, and puts extra stress on other structures that usually help with the stability of the hip.  A few of the many factors that provide hip stability include the cartilage rim (labrum) that helps provide depth to the socket, the capsule with thickenings which are the ligaments of the hip, and the muscles around the hip. With excessive motion of the ball, the labrum can get torn, and the ligaments can stretch out further, resulting in even greater movement of the ball within the socket. The muscles around the hip work harder to keep the ball in the joint, and they can get inflamed and overused, making it harder to keep the ball centered in the socket. That is further compounded by the fact that if the hip hurts, and you favor your hip, it can get weaker, making it less effective at keeping the ball centered in the socket, and thus resulting in even more motion of the ball within the socket. This is not a true hip dislocation.

FREQUENT SIGNS AND SYMPTOMS

  • Rarely does it feel like the hip is “coming out of the socket” or “slip out of place”

  • Pain or aching (usually located at the inner hip, or groin area), particularly when walking and your leg is behind you

  • A “locking”, “clicking” or “catching” sensation within the joint

  • Pain sitting for long periods of time, like in a car

  • Low back pain

  • Pain at the SI (sacroiliac joint on back of pelvis), the buttock, or greater trochanter (side of hip)

  • It is often confused with other sources of pain, such as hipflexor or pain from the back

CAUSES OF MICROINSTABILITY

  • May occur without any injury

  • Direct blow forcing hip hyperextension or fall onto a bent knee

  • Usually microtraumatic or atraumatic onset

  • Congenital (born with) abnormality, such as a shallow or malformed joint surface or ligament disorder

  • Repetitive activities that force range of motion (such as turn out in ballet, forces stretching of a main hip ligament)

  • Cutting of hip ligaments or capsule with prior surgery that is not repaired or did not heal

RISKS INCREASE WITH…

  • Sports that stress range of motion / laxity such as dance, ballet, synchronized swimming, and gymnastics

  • Previous hip dislocations or sprains

  • Shallow hip socket (hip dysplasia)

  • Loose jointed / double jointed (benign hypermobility, Ehlers Danlos syndrome)

  • Poor physical conditioning (strength/flexibility)

  • Prior hip arthroscopy

EXPECTED OUTCOME

With appropriate management, including rehabilitation or surgery, this problem can be sufficiently treated to return to activities.  Early data suggests that 50% of patients that present with hip instability can be adequately treated with just rehabilitation. Surgery, when necessary is very effective.

POSSIBLE COMPLICATIONS

  • Damage to the labrum or joint cartilage injury due to the increased stresses to this structures

  • Prolonged healing or recurrent dislocation if activity if activity is resumed too soon

  • Inability to return to activities

  • Unstable or arthritic shoulder following repeated injury, or if there is associated fracture

GENERAL TREATMENT CONSIDERATIONS

Initial treatment consists of medication and ice to relieve the pain, and strengthening exercises of the hip and core while modifying activities which cause symptoms. This is to maximize the dynamic stabilizers of the hip – those that are modifiable – your muscles. These exercises all can be carried out at home, though referral to a physical therapist or athletic trainer for further evaluation and treatment may be helpful. Usually, you go to physical therapy 1-2 times a week, but do exercises on your own, at home 5 -6 days a week. Rarely, an injection of cortisone into the joint or iliopsoas bursa may be needed to reduce the pain to allow you to perform the rehabilitation with sufficient intensity. For those with persistent pain after full return of strength (usually at least 6 – 12 weeks), surgery may be needed to tighten the hip ligaments. If surgery is necessary, you will be on crutches and may need a brace initially after surgery. It will take 4-6 months after surgery before you will be able to return to full activity, though you will only feel about 80% of normal. It will take nearly a year to fully recover (be at least 90%).

MEDICATION

  • Non-steroidal anti-inflammatory medications, such as aspirin and ibuprofen (do not take if surgery planned within 7 days), or other minor pain relievers, such as acetaminophen, are often recommended. Take these as directed by your physician - contact your MD immediately if any bleeding, stomach upset or an allergic reaction occurs

  • Pain relievers are usually not prescribed for this condition.  If your physician does prescribe pain medication, use only as directed

  • Cortisone injections to reduce inflammation to allow for rehabilitation, and anesthetics temporarily relieve pain to confirm the location of the pain

APPLICATION OF HEAT AND COLD

  • Cold is used to relieve pain and reduce inflammation. Cold should be applied for 10-15 minutes every 2-3 hours for inflammation and pain, and immediately after any activity which aggravates your symptoms.  Use ice packs or an ice massage

  • Heat may be used prior to performing stretching and strengthening activities prescribed by your physician, physical therapist or athletic trainer.  Use heat pack or a warm soak