Knee Information

Background 

The anterior cruciate ligament (ACL) is important for both anterior-posterior and rotational stability in the knee. The ACL is most commonly torn during a non-contact pivoting mechanism, and ACL injuries may be associated with meniscal tears, cartilage injury and injury to other ligaments. 

ACL injuries are one of the most common conditions treated by sports surgeons. In my experience, ACL injuries may be overlooked in the urgent care or emergency room setting because x-rays are typically normal and physical exam is often inaccurate after an acute injury. If you injured your knee acutely, experience significant knee swelling, and have any sensation of instability/giving way of your knee, particularly with twisting and pivoting, then an ACL injury should be considered. 

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Management

In cases of partial ACL tear with a stable knee exam, or complete tears in patients with lower athletic demands, non-operative management may be considered. Non-operative treatment does not mean “no treatment”, and significant rehabilitation guided by a skilled physical therapist, and bracing may be necessary. 

Complete tears of the ACL in active patients and athletes are typically treated surgically to restore stability of the knee, prevent future meniscal and cartilage injury and restore active lifestyle and function. The standard of care for surgical treatment of ACL tears is ACL reconstruction, where a tissue graft (typically from your own knee, sometimes from a cadaver) is used to reconstruct the structure and function of the ACL. In some cases, ACL repair may be considered. There are various graft options, and no one-size-fits-all approach in my hands. This will be discussed in detail at your visit. 

Unfortunately, it is possible to re-tear your ACL even after a successful and technically well-done surgery. If this is the case, surgical revision may be offered. Revision surgery may require a more extensive diagnostic workup, and may require multiple surgeries (i.e. staged procedures). 

Recovery and Prognosis 

Most patients are able to ultimately return to sports, some at very high levels, after ACL injury and reconstruction. Typically return to competition or high risk sports occurs at 9-12 months minimum after surgery, and depends on progress with physical therapy. It is critical to allow adequate time for graft healing and incorporation, and also to regain full strength, agility and muscle coordination prior to return. This will minimize the chance of re-injury in the future. 

Background 

The meniscus is a wedge-shaped fibrocartilage structure that sits between the cartilage of your femur and tibia in the knee joint. Each knee has a medial and lateral meniscus. The meniscus is important for force distribution (i.e. shock absorption) in the knee joint as well as knee stability. Meniscus tears are very common, and may occur acutely or chronically with wear and tear. Patients with knee arthritis (even mild arthritis) very commonly have degenerative meniscal tears. A meniscus tear is associated with pain along the joint line, clicking/catching/popping, knee swelling, and sometimes locking or loss of range of motion in larger displaced tears. Meniscal tears are commonly associated with ACL and other knee ligament injuries. 

Historically, the meniscus was thought to be a vestigial structure that was not important for the health of your knee joint. This led to the meniscus being aggressively treated and often removed either partially or completely when tears were present. Unfortunately this practice led to development of early arthritis in many patients. This paradigm has changed, and the importance of the meniscus in knee joint function and cartilage health has been increasingly recognized, leading surgeons to strive for meniscal preservation when possible.

Management

Small meniscal tears and degenerative tears associated with arthritis can often be treated non-surgically. This may involve a period of rest from high impact exercise and sports, physical therapy and sometimes injections. 

Larger meniscal tears, bucket handle tears, meniscal root  tears and flap tears causing painful mechanical symptoms (i.e. locking/catching) may benefit from surgery. Surgery is performed arthroscopically in most cases and involves re-aligning the meniscus and securing the tear with sutures to allow the meniscus to heal (arthroscopic meniscus repair). 

In the case of chronic degenerative tears, or tears with a very low chance of healing, then partial meniscectomy (removal of the torn part of the meniscus) may still be performed. This is commonly referred to as a knee “clean up” or “scope” type procedure. 

There are various meniscal repair techniques (all-inside, inside-out, outside-in, meniscal root repair) that may be utilized. I use a combination of these techniques depending on the specific tear. 

In rare instances where the majority of the meniscus is absent or not repairable in an otherwise healthy knee, meniscal allograft transplantation (meniscal replacement) may be considered. This is typically performed as a staged procedure, and may sometimes be combined with an osteotomy to realign the knee joint and offload the transplanted meniscus.

Recovery and prognosis 

Most patients return to sports and an active lifestyle after meniscus surgery. If a simple knee scope with partial meniscectomy, full return to activity may be possible within 4-6 weeks.

In the case of meniscal repair, recovery is a much lengthier process. The meniscus has a somewhat limited blood supply and takes several months to fully heal after successful repair. Strength, agility and coordination must also be regained in order to minimize risk of repeat injury in the future. 

Specific timeline for return to sports is determined on an individual basis, but may be 4-6 months or longer depending on the extent of the injury. I will work with you and your skilled physical therapist to guide your rehab and recovery.

References 

1. Orthoinfo
2. Patel, H., Skalski, M. R., Patel, D. B., White, E. A., Tomasian, A., Gross, J. S., ... & Matcuk Jr, G. R. (2021). Illustrative review of knee meniscal tear patterns, repair and replacement options, and imaging evaluation. Clinical Imaging, 69, 4-16.

Background

Patellar instability refers to subluxation (i.e. partial dislocation) or complete dislocation of the patella (kneecap). Patellar instability events occur most commonly during sports by a non-contact mechanism.

There are various anatomic risk factors for patellar instability including knee alignment, ligamentous laxity, patellar tendon length and trochlear groove shape, all of which must be considered in treating patellar instability.

The medial patellofemoral ligament (MPFL) is a thick band of tissue that spans between the medial aspect of the patella and the medial aspect of the distal femur. When the patella dislocates, the MPFL is sprained or torn. Injury to this ligament increases the risk of recurrent instability events in the future.

Additionally, cartilage injury is common during a patellar instability event. Sometimes a piece of cartilage can be fractured or dislodged from the kneecap or femur, which may require surgery to fix or remove.

It is common for the patella to spontaneously reduce back into place after a subluxation or dislocation event, which can happen very quickly. In some cases, the kneecap remains dislocated and requires formal reduction by a trained medical provider. 

Management

In most patients with a suspected or confirmed patellar instability event, I will obtain both complete x-rays and an MRI. X-rays are often negative, and MRI is necessary to rule out other injuries, assess risk factors for recurrence and to assist with surgical planning in some cases. 

Initially, most patellar instability events can be managed without surgery. This involves a brief period of immobilization, pain and swelling control, followed by gradual progression of range of motion and strengthening with physical therapy. I typically recommend use of a patellar stabilizing knee brace during rehab and future sports participation. 

In cases of cartilage fracture or loose body in the knee, surgery may be indicated more urgently. 

In cases of recurrent patellar instability, surgery may be offered. This typically involves reconstruction of the medial patellofemoral ligament with cadaver tissue. Sometimes additional bone realignment such as tibial tubercle osteotomy is necessary to minimize risk of recurrence.

Recovery and Prognosis 

When managed without surgery, patients usually require 6-8 weeks of skilled physical therapy prior to gradual return to sports and activities. 

If surgery is performed, the healing and rehab process is more involved. Return to competitive sports is similar to an ACL reconstruction, and may take up to 9 months to fully regain strength, agility and coordination necessary to safely compete.

If a tibial tubercle osteotomy is performed as part of your procedure, there will be an approximately 6 week period of non-weight bearing on the operative limb after surgery.