Problems affecting the patellofemoral joint most frequently include pain, instability (subluxations or dislocations of the patella – when the kneecap moves partially or fully out of the groove in the femur) and arthritis.

Arthroscopy and debridement
Lateral release
Vastus medialis plasty
Trochleoplasty
Lateral Facet Resection
Mosiac Plasty

Tibial tubercle osteotomy:

• Elmslie-trillat
• Hauser
• Maquet
• Fulkerson (DMZ)

Patellofemoral arthroplasty
Total Knee Replacement

There may be need for surgical intervention on the patella for a number of reasons such as:

1. Patella Dislocation
2. Patella Fracture
3. Patella Alta & Baja
4. Maltracking

There are number of surgical options on the kneecap and the method and procedure differs depending on the condition.

1. Realignment Surgery

• Lateral Release
• Quad Transfer
• Patella Tendon Transfer
• Tibial Tubercle Transfer
• Osteotomies to correct dysplasia

2. Patellectomy

The first artificial knees were little more than crude hinges. Now, you and your doctor can choose from a wide variety of designs that take into account your age, weight, activity level and overall health. Most knee replacement joints attempt to replicate your knee’s natural ability to roll and glide as it bends.

Your knee is divided into three major compartments: The medial compartment (the inside part of the knee), the lateral compartment (the outside part), and the patellofemoral compartment (the front of the knee between the kneecap and thighbone).

In a unicompartmental knee replacement, only the damaged compartment is replaced with metal and plastic. The healthy cartilage and bone in the rest of the knee is left alone.

Knee osteotomy is most commonly performed on people who may be considered too young for a total knee replacement. Total knee replacements wear out much more quickly in people under the age of 55 than in people over the age of 70.

Many people who undergo knee osteotomy will eventually need a total knee replacement — usually about 10 to 15 years after the knee osteotomy.

Arthroscopy allows the surgeon to see inside your joint without having to make a large incision. Surgeons can even repair some types of joint damage during arthroscopy, with pencil-thin surgical instruments inserted through additional small incisions.

Tearing of the ACL is the most common knee ligament injury. Sports and fitness routines that involve running, pivoting, turning and jumping lead to many torn ACLS.

The ACL is one of the main stabilizing ligaments of your knee. It prevents the lower leg bone (tibia) from going too far forward. Once torn, the ACL won’t heal, so fusing the torn ends is not an option. With ACL reconstruction, the torn ligament’s function is not restored. ACL reconstruction involves creating a new ACL from grafted tissue.

There are four different grades of classification in which medical doctors classify a PCL injury:

• Grade I, the PCL has a slight tear.
• Grade II, the PCL ligament is minimally torn and becomes loose.
• Grade III, the PCL is torn completely and the knee can now be categorized as unstable.
• Grade IV, the ligament is damaged along with another ligament housed in the knee (i.e. ACL).

With these grades of PCL injuries, there are different treatments available for such injuries

1. 1. Arthroscopic lavage / debridement
   2. Marrow stimulation techniques (microfracture surgery and others)
   3. Marrow stimulation augmented with hydrogel implant
   4. Marrow stimulation augmented with peripheral blood stem cells
   5. Osteochondral autografts and allografts
   6. Cell-based repairs
   7. Autologous mesenchymal stem cell transplant

Treatment of surface chondral lesions with ACI
Following diagnostic arthroscopy and defect evaluation, chondrocyte harvest can be undertaken. Biopsy 2 large, “tic-tac”-sized, full-thickness samples (5 x 8 mm) from an area of minimal weight-bearing articular cartilage, usually the intercondylar notch. Harvest approximately 200 to 300 mg of chondrocytes and send them to the lab to be cultured and processed in preparation for reimplantation. The remainder of the knee, including both menisci must also be evaluated arthroscopically.

If after arthroscopic evaluation, it was determined that the patient should undergo a autologous chondrocyte implantation procedure the chondrocyte harvest can be undertaken. Biopsy a large, “tic-tac”-sized, full-thickness sample (5 x 8 mm) from an area of minimal weight-bearing articular cartilage, usually the intercondylar notch. Harvest approximately 200 to 300 mg of chondrocytes and send them to the lab to be cultured and processed in preparation for reimplantation.

During the second, implantation stage, make a mini-arthrotomy, taking care to protect the native articular cartilage and meniscus. After exposure, prepare the defect to a stable vertical rim. Size the defect with a ruler and outline it using sterile glove paper. Use this tracing as a template to create a correctly sized collagen membrane patch to cover the defect. Use of a collagen patch (Biogide; Geistlich, Germany) currently represents an FDA of-label use. Cut this patch to size using the previously made template and then allow the patch to soak in a vial of harvested cartilage cells, mimicking “3rd generation” ACI technique. Then sew this collagen membrane over the defect using 6-0 vicryl suture. Ensure a watertight seal with a saline injection trial: Use a sterile angiocath to introduce a small amount of sterile saline underneath the patch. Reinforce any leaks with additional suture. Remove the saline from the defect and inject the chondrocytes underneath the patch. Use the 6-0 vicryl suture to sew shut the injection site underneath the patch and then reinforce the entire patch with fibringlue around the periphery.

Postoperative Care
Immediately following the procedure, place the patient in a hinged knee brace locked in extension for 24 hours to allow the implanted cells to adhere and remain underneath the patch. The patient should be made non-weight-bearing during this time period. After 24 hours, gentle range of motion (ROM) with a continuous passive motion (CPM) machine is initiated from 0° to 30°. CPM use is encouraged for roughly 6 hours per day for the first 6 weeks,with a 5° to 10° increase in range of motion daily. By 4 weeks, there should be at least 90° of flexion and 120° to 130° by week 6. Gentle passive ROM promotes difusion and movement of synovial fluid.

Discussion
Several studies in the orthopaedic literature have demonstrated successful results, both short- and long-term, using ACI. Peterson et al demonstrated roughly 80% good to excellent results at both 2-year and long-term (5 to 11 years) follow up. Minas et al similarly demonstrated an 87% success rate in 169 patients with a minimum of 1 year of follow-up. An additional study in Sweden had long-term follow-up of 10 to 20 years and showed patient satisfaction rates as high as 92%, with over 75% of patients saying they would undergo the procedure again.

Although the studies mentioned above were done in the general population, the results of ACI appear to be just as promising in athletes. A more recent study comparing ACI with microfracture, another common cartilage repair procedure, confirmed the durability and positive long-term results of ACI, versus microfracturing even in athletes.