Knee - Patella Instability
Description
The patella (aka-kneecap) is a floating bone above the knee joint that is held in place by tendons, a ligament (medial patellofemoral ligament/MPFL) and soft tissue surrounding the joint (aka- capsule) when the knee is straight.
What are the causes?
Patella instability is usually caused by a combination of factors, including trauma, forceful quadriceps muscle contraction and/or anatomical and genetic factors that increase the risk of dislocation (females>males due to greater Q-angle, shallow groove, collagen tissue disorders resulting in hyperflexibility).
What are the symptoms?
Patella instability may cause the patient to feel like the knee is giving out. Patella dislocation causes immediate pain and obvious deformity with the patella located on the outside of the groove (typically towards the outside of the leg). Motion and function are not possible with patella dislocation.
How is it diagnosed?
Dr. Liu will perform a thorough history and physical exam, aided by X-rays. In cases of patella instability, your surgeon may be able to move the patella out of the groove in a controlled manner. The patella may move in a J pattern when extending the knee, but full range of motion and strength are preserved.
In cases of patella dislocation, range of motion will be minimal and the knee will have a visible deformity. X-rays will show the dislocated patella. After reduction, MRI may be helpful to evaluate the ligament that holds the patella in the groove (MPFL) and the cartilage around the knee to ensure it wasn’t damaged during the dislocation.
Non-operative
For patella instability/subluxation, physical therapy will be prescribed to strengthen the inner quadriceps muscle. A brace will provide additional support and keep the kneecap in its groove.
Initial treatment of patella dislocation should be non-operative. Your surgeon may prescribe anti-inflammatory medication, cryotherapy and rest. The leg may be placed in a brace designed to hold the kneecap firmly in the groove and allow the injured ligaments to heal. An initial period of immobilization is followed by physical therapy, initiated at your surgeon’s discretion. The patient may return to sports when strength and range of motion are equal to the opposite knee.
Operative
Surgical treatment is indicated in cases of dislocation if the patient fails non-operative treatment (continued pain, instability) or other structures (MPFL, joint cartilage) were injured at the time of dislocation. If fragments of joint cartilage (aka- loose bodies) are identified, minimally-invasive arthroscopic surgery can be performed to repair or remove the fragments. If a patient suffers two or more dislocations, then the surgeon may recommend a procedure to stabilize the kneecap (MPFL plication/reconstruction/repair). Other anatomic causes of instability can also be addressed through an open incision at the time of surgery (shallow groove=Trochleoplasty, poor alignment=Tibial Tubercle Osteotomy).
MPFL plication
Can I shower after surgery?
If you have a bulky dry dressing you can remove it on postop day #3; you may then shower allowing water to run over steri-strips or sutures; towel pat dry and keep clean; NO soaking or submerging operative body part. If you have a waterproof dressing, please leave it on until you follow up in the office. You can shower over the dressing, no soaking or submerging the shoulder
How long do I need to wear the compression stockings?
Dr. Liu wants you to keep the compression stockings on for 3 weeks. Compression stockings are the best way to help the swelling to go down after surgery.
Should I use ice or heat?
Ice can provide analgesic effects and control swelling for the first 3-5 days; after that we recommend ice after exercises or PT.
How do I use an ice machine or CPM?
if either device is part of your recovery, treat this as an assistance to your recovery. Use either as directed, allowing only the machine to move or do the work. Remember, you should not be doing the work or moving the operative body part on your own.
How do I decrease my pain after surgery?
You may take your pain medication as prescribed; if pain continues, you may add ibuprofen or naproxen in between pain medication doses: (8am pain med, 10am ibuprofen 600-800mg or naproxen 500mg, 12p pain med).
Who schedules my first post operative appointment?
You are responsible for scheduling this appointment. This can be done prior to your surgery or within 1-3 days following. Please call the office, at 702-740-5327, provide your date of surgery, and you will be provided your appointment time and date.
When can I drive?
This depends on your surgery. Please wait until your first post op visit to discuss with your provider.
When can I go swimming?
Please wait at least 4 weeks until you submerge your incision into baths or pools. When your incision is submerged, it can open up and increase risk of infection. We ask that you wait 4 weeks when the incision is healed to soak in tubs or pools.
When do I start Physical Therapy?
Physical Therapy will be discussed at your first postoperative visit 10-14 days after surgery.
I have questions that have not been answered.
Please re-read your postoperative instructions handout. If questions remain, please contact the surgery line that has been provided to you on your post surgical handout.