Platelet Rich Plasma Therapy

Platelet Rich Plasma, or PRP, is a volume of the plasma of autologous blood having a platelet concentration above the baseline. Platelets facilitate healing by stimulating the release of different growth factors. The growth factors recruit stem cells that assist with healing, repair, or regeneration of the injured tissue. PRP is injected directly into the injured tissue, stimulating a healing response in a more powerful form.

Red Blood Cell

In order to understand PRP, you must know that platelets are components of blood cells. The development of PRP focuses on the concentration of the patient’s own blood platelets to create an active mixture of growth factors. The other components of blood are the red and white blood cells. Red blood cells carry oxygen from the lungs and deliver it to the body tissues. White blood cells form our immune system and help the body to fight against infection and foreign materials.



Active Platelet

Platelets aid in hemostasis (stop the bleeding) and in building new tissues—they act as a scaffold for tissue regeneration. Platelets aid in the attraction and binding of stem cells. Platelets act as the directors while stem cells work. Platelets divide, multiply and differentiate to become the healing cells for injured tissue. The platelets become activated by thrombin and other factors which cause a change in their morphology and the release of multiple growth factors. These growth factors bind themselves to the receptors of the cell causing intracellular changes down to the nucleus and affecting its DNA.  The result is a change in the performance and function of the cell.

In order to produce PRP, 30-60mLs of the patient’s own venous blood is drawn from the antecubital vein. The blood is then placed into a device to be centrifuged which separates the blood into platelet poor plasma (PPP), red blood cells (RBC), and platelet rich plasma (PRP). The blood is then placed in a centrifuge for 15 minutes at 3,200 rpm. The centrifuge spins and separates the platelets from the rest of the blood components and increases the concentration of platelets and growth factors. The more platelet concentration, the greater the healing power. After the centrifuge process is complete, the plasma has been separated from the blood producing the PRP and the platelet poor plasma is withdrawn to be discarded. Platelet rich plasma is withdrawn for injection. Sodium Bicarbonate is used to neutralize the acidity of the sample. The more platelet concentration, the more growth factors and healing power the sample has.

Ultrasounds help deliver a concentrated sample of platelets to the injured tissue. Ultrasound increases the accuracy of delivering the sample to the injured tissue. Preferably, injections should be performed with the aid of ultrasound imaging. Needling induced injury releases thrombin which activates the platelets. Platelets help in hemostasis and produce growth factors as well as chemotactic factors. Platelets act as a scaffold for mesenchymal stem cells which start the process of tissue regeneration. Patients will typically experience minimal to moderate discomfort which may last up to one week following the injection. Avoid the use of anti-inflammatory medications for 6 weeks after the injection.

Hangman's Fracture

The hangman’s fracture refers to the bilateral fracture of the pars interarticularis. When this fracture occurs, the spinal canal is widened and there is a low risk for spinal cord injury. This fracture usually occurs due to motor vehicle accidents.

Hyperextension will fracture the pars interarticularis with secondary flexion, injuring the disc and posterior ligament. The patient may have other associated spine fractures.

Hangman’s fractures are identified by types using the Levine and Edwards Classification.

Type I

Type I:

• Stable fracture with less than 3mm displacement

• No angulation

• Treatment: Cervical Orthosis
  

Type II

Type II:

• Most common type

• Significant translation and some angulation

• Unstable fracture

• Treatment: Cervical traction to improve the displacement and immobilization in halo vest

Type IIa

Type IIa:

• Slight translation but severe anglulation seen in flexion distraction injuries with tearing of the posterior longitudinal ligament and the disc.

• The fracture is unstable

• Treatment: reduction in extension and compression in a halo

• Do NOT use traction when there is severe angulation of the fracture  

 

Type III

Type III:

• C2-C3 facet dislocation

• Rare fracture that results from initial anterior facet dislocation of C2 on C3, followed by an extension injury fracturing the neural arch.

• Results in translation with unilateral or bilateral facet dislocation of C2-C3.

• Unstable fracture

• Treatment: surgery for reduction of the facet dislocation and stabilization of the injury

 

Typical and Atypical fractures

A typical hangman’s fracture displaces the vertebral body anteriorly and its posterior element posteriorly. This creates increased space for the spinal cord.

Atypical Hangman's Fracture

An atypical hangman’s fracture line leave the canal circumferentially intact, which puts the spinal cord at risk of injury if displacement occurs.

 

Total Hip Acetabular Screw Placement

Utilizing acetabular screws in total hip arthroplasty is controversial. Screws can compress the cup and close any gap. Screws could be helpful in osteoporotic bone and when the bone coverage is not sufficient. Screws and its holes can be conduit for migration of polyethylene debris that can cause osteolysis (The surgeon should insert the least number of screws).

Many surgeons prefer to use screws in the acetabular cup. The quadrant technique is a safe technique of screw placement. It provides the surgeon with a simple, basic guide during surgery for safe placement of the screws during the primary and revision surgery.

In order to find the safe zone for the placement of acetabular screws and avoid the danger zone, you will need to draw a line from the Anterior Superior Iliac Spine (ASIS). Then you will draw a second line, perpendicular to the first line. Drawing these lines will divide the acetabulum into four quarters. The posterior-superior quarter is considered the safe zone. There is minimal risk to the sciatic nerve, superior gluteal nerve, and vessels. It is important to direct the screws away from the notch. The anterior-superior and anterior-inferior quarters are considered to be the danger zone due to the external iliac artery and vein as well as the obturator nerve, artery, and vein are at risk. The posterior-inferior quarter is considered the caution zone. Placing screws here can be safe if the screws are less than 20mm. There are still several risks when placing screws in this area and these risks include: the sciatic nerve, inferior gluteal nerve and vessels, internal pudendal nerve and vessels.

A retroverted vertical cup will be at most risk for injury to neurovascular structures. The structures can be at risk in a high hip center, which is reamed superiorly ½ the native acetabular diameter. The new hip will have different anatomic zones than what the surgeon might think. The antero-superior and the antero-inferior quadrants are positioned in the postero-superior quadrant (Be aware of the shift in the zones). The insertion of the screws as guided by the quadrant method is based on a study done by Dr. Ray Wasielewski and his colleagues. When in doubt, aim the screws anteriorly to the greater sciatic notch. The bone will be stronger and thicker. Screws longer than 35mm are usually not needed. Avoid drilling eccentrically because it may lift up the liner. The screw must be fully seated and the head of the screw should not be proud. If the screw is proud, the liner may not be seated properly.

Vascular injuries occur more in females and more often in the left hip.

Tibial Plateau Fracture Balloon Osteoplasty

A tibial plateau depression fracture occurs when axial forces from the femoral condyles against the articular surface of the tibia cause the injury. The compression fracture may also be associated with other fractures. Several techniques are used for the treatment of this fracture. Balloon osteoplasty is proposed as a useful tool for reduction and elevation of the tibial plateau depression fracture.

The technique of balloon osteoplasty can be done with or without the supplementation of screws and plate fixation. Trajectory lines are drawn on the medial side of the knee for access to the fracture area. A small incision is made at the point where the lines cross. A cannula and trocar tip stylet is used to access the fractured area under radiographic guidance. The cannula and trocar is advanced under the area of depression using a mallet or drill when needed. Once inserted, the trocar is then removed from the cannula.

 The precision drill is then inserted into the cannula and advanced until it passes under the depressed area of bone. Then, the precision drill is removed from the cannula and the inflatable bone tamp is inserted through the cannula to the area of the depressed fragments. The inflatable bone tamp is centered under the area of depression and then inflated to reduce the depression fracture. Once the depression has been adequately reduced, the inflatable bone tamp can be deflated and removed from the cannula.

The void that has been left by the inflatable bone tamp is now ready to be replaced with bone filler. The device loaded with injectable material is inserted and used until the void is completely filled. Finally, you will remove the injectable material device and the cannula. Plate fixation may be added before or after the injectable material is inserted.