Closed Reduction and Percutaneous Pinning (CRPP) is an orthopedic technique used to stabilize certain bone fractures without a large surgical incision. This minimally invasive procedure restores the bone’s alignment while minimizing disruption to surrounding soft tissues. CRPP combines external manipulation of the bone fragments with the placement of metal pins to hold the fracture securely during healing. This method is a common alternative to open surgery for specific injury patterns, particularly in the elbow, wrist, and ankle.
When is CRPP Used?
CRPP is reserved for unstable fractures that can be successfully realigned through external manipulation, meaning the bone fragments are not severely displaced or fragmented. It is often the preferred choice for pediatric fractures, such as displaced supracondylar humerus fractures, because it preserves growth plates and minimizes soft tissue damage. CRPP is considered the standard treatment for many displaced fractures in the pediatric elbow.
The procedure aims to achieve strong, anatomical stability without a large open incision, which can risk the blood supply to the bone fragments. In adults, CRPP is utilized for select injuries like certain distal radius (wrist) and ankle fractures. This method is most effective when the bone quality is adequate and the fracture fragments are few and large enough to be controlled by the pins. The ability to perform a successful closed reduction determines if the surgeon can proceed with the percutaneous pinning.
The Procedure Explained
The CRPP procedure begins with the “closed reduction” phase, performed while the patient is under anesthesia. The surgeon manually manipulates the fractured limb from the outside to bring the bone fragments back into their correct anatomical position. This realignment relies on specialized X-ray equipment called a fluoroscope, as the bone is not directly viewed. The fluoroscope provides real-time images, allowing the surgeon to precisely monitor the bone fragments’ position during manipulation.
Once the fracture is reduced, the “percutaneous pinning” phase begins, using small, smooth metal wires known as Kirschner wires (K-wires). The surgeon uses the fluoroscope to guide these wires across the fracture site to hold the fragments firmly in place. The wires are driven into the bone using a specialized drill or driver, typically placed to cross the fracture line. Multiple K-wires are often inserted in diverging patterns to maximize stability at the fracture site. After fixation, the ends of the wires are bent and cut just beneath or left protruding slightly outside the skin for easy removal later, and the limb is then immobilized.
Recovery and Pin Removal
Immediately following the procedure, the patient’s limb is immobilized with a cast or splint to protect the fracture site and the pins. Patients are typically monitored for a few hours and often discharged home the same day, as the procedure is outpatient. Post-operative care involves careful monitoring of the pin sites to prevent infection, and patients are instructed on how to check for adequate circulation.
The pins remain in place until initial bone healing is confirmed, which usually takes about three to six weeks. Follow-up X-rays assess the progress of the bone union before the hardware is removed. The removal of the K-wires is a fast and simple procedure generally performed in the doctor’s office or clinic, not the operating room.
For pin removal, the surgeon or physician assistant uses a special tool to grasp the exposed end of the wire and gently pull it out. This process is quick and may cause brief, minor discomfort, often managed with over-the-counter pain medication. After the pins are removed, the patient may continue with splinting or casting, and physical therapy may be prescribed to restore the joint’s full range of motion and strength.