Kneecap Instability
Patellar Instability & Kneecap Dislocation in Glendale, AZ
The kneecap, or patella, rides in a groove at the end of the thigh bone. When it slips partly or fully out of that groove, the knee gives way, swells, and often tears the ligament that holds the kneecap in place. A first dislocation is painful; repeated dislocations damage cartilage and erode confidence in the knee. Dr. James MacKenzie treats patellar instability in Glendale, Arizona, from bracing and therapy after a first dislocation to MPFL reconstruction for patients whose kneecap keeps slipping.
Why patients choose Dr. MacKenzie
- Board-certified orthopedic surgeon
- Fellow, American Academy of Orthopaedic Surgeons (FAAOS)
- Johns Hopkins residency, sports medicine fellowship
- Former assistant team physician, Miami Dolphins & Miami Heat
- Nonsurgical options first, surgery only when needed
- Se habla español
Why Kneecaps Dislocate
A dislocation usually happens with a twist on a planted foot or a direct blow to the inside of the knee. Some people are more prone because of a shallow groove, a high-riding kneecap, or alignment that pulls the patella outward. Teenagers and young adults, particularly female athletes, are most often affected. The medial patellofemoral ligament (MPFL), the main restraint on the inside of the knee, tears in most first-time dislocations.
After a First Dislocation
Most first-time dislocations are treated without surgery: a short period in a brace, then physical therapy focused on the quadriceps and hip. Dr. MacKenzie orders an MRI after a first dislocation to check for a loose piece of cartilage or bone, because a loose fragment usually needs to be removed or fixed promptly even if the ligament is treated with therapy.
When Surgery Makes Sense
Surgery is considered when the kneecap dislocates again despite therapy, when a cartilage fragment is loose in the joint, or when the knee feels so unstable that the patient avoids activity. Each additional dislocation raises the risk of cartilage damage, so Dr. MacKenzie discusses stabilization sooner for athletes and for patients with the anatomy that makes repeat dislocations likely.
MPFL Reconstruction
MPFL reconstruction rebuilds the torn ligament with a tendon graft, anchored to the kneecap and the thigh bone, so the patella is held in its groove through the full range of motion. It is performed through small incisions as outpatient surgery. For patients whose alignment or bone shape contributes to the problem, Dr. MacKenzie may combine it with a procedure that repositions the attachment of the patellar tendon.
Recovery After Stabilization
Most patients walk with a brace and crutches for the first few weeks, then progress through therapy to restore motion, quad strength, and hip control. Straight-line running typically begins around three months, and return to cutting and jumping sports usually takes five to six months, guided by strength and functional testing rather than the calendar.
Protecting the Cartilage
The undersurface of the kneecap takes the brunt of every dislocation. During stabilization, Dr. MacKenzie inspects the cartilage and treats any damage he finds. Over the long term, a stable kneecap and strong quadriceps are the best defense against kneecap arthritis.
Risks
Risks of patellar stabilization surgery include infection, blood clots, stiffness, persistent pain, recurrent instability, over-tightening that limits bending, and the need for additional surgery. Dr. MacKenzie reviews these risks and how they apply to your knee before surgery.
Questions
Frequently Asked Questions
Don’t see your question here? Our team is happy to help.
Will my kneecap dislocate again?
After a first dislocation, a significant number of patients, especially younger athletes, experience another. Risk depends on age, anatomy, and activity, which is why an evaluation after the first event matters.
Do I need surgery after one dislocation?
Usually not, unless there is a loose fragment of bone or cartilage. Most first dislocations are treated with a brace and therapy.
How long does MPFL reconstruction take?
The procedure usually takes about an hour and is performed as outpatient surgery.
Can I play sports again after MPFL reconstruction?
Most athletes return to their sport, typically five to six months after surgery once strength and functional tests are passed.
Does a knee brace prevent dislocations?
A patellar stabilizing brace can help during the recovery period and for some activities, but it does not substitute for a strong quadriceps or, when needed, surgical stabilization.
Schedule a Consultation with Dr. MacKenzie
Call the office or request an appointment online and our team will help you take the next step.