Physeal Sparing Surgery (Anderson’s Technique)
What is Physeal Sparing Surgery?
Surgery may be necessary to reconstruct an irreparable anterior cruciate ligament (torn ACL). In adults, reconstruction of the ACL involves passing a soft tissue graft through tunnels drilled into the shinbone (tibia) and thighbone (femur). In a child or adolescent, such tunnels may damage the physes or growth plates (areas at the ends of long bones where growth is still occurring). A physeal-sparing technique may be recommended where the physes in the tibia and femur are left undisturbed avoiding complications such as growth disturbance or angular deformity.
Anderson’s technique is a type of physeal sparing surgery where the tunnels are created within the epiphyses, the ends of the bones beyond the physes.
What are the Indications for Physeal Sparing Surgery?
ACL reconstruction is recommended for active children who are involved in sports or recreational activities. Severe knee pain and inability to continue activities are the primary indications for ACL reconstruction.
The other indications include:
- Failure to improve or comply with non-operative treatment
- A recurrent feeling of knee instability with daily activities
- Repeated episodes of the knee “giving way”
- Associated meniscal tears and/or severe injuries to other knee ligaments
- Generalized laxity of the ligaments
Knee instability due to an ACL tear can lead to meniscal and cartilage injuries and early onset of arthritis.
Physeal sparing surgery is preferred for children younger than 10-12 years of age with significant skeletal immaturity.
What are the Benefits of Physeal sparing Surgery (Anderson Technique)?
The benefits of the procedure include:
- ACL reconstruction at the native footprint (part of the bone where the ligament is attached) is anatomic having better functional results
- No injury to physes minimizing the risk of growth disturbance, leg length abnormalities and angular deformities
- Cartilage damage is minimized due to improved stability
- Good to exceptional functional results
How do you Prepare for Physeal Sparing Surgery?
The injury can result in swelling and stiffness. Before surgery, you may need to undergo some physical therapy to improve range of motion. If the knee is stiff at the time of surgery, restoring range of motion may be difficult afterwards. Your doctor may recommend using a brace to allow some healing of the ligaments before surgery is performed. You may be given specific instructions on dos and don’ts before and on the day of your surgery. Instructions may include details on food intake, medication, etc. Arrange for someone to drive you home after surgery.
Anderson Technique for Physeal Sparing Surgery
Your surgeon will use a hamstring autograft to reconstruct the ACL. During the procedure, the surgeon will use intraoperative fluoroscopic imaging or CT scanning along with arthroscopic visualization and:
- Make required incisions on the skin over the knee joint
- Expose the ACL ligament attachment
- Remove damaged tissue and debris
- Repair any meniscal injuries
- Drill bone tunnels corresponding to the ACL attachment keeping the tunnels within the epiphysis of the femur and tibia
- Pass the graft through the tunnels and use devices such as screws to secure the graft to the bone.
What are the Risks Associated with Physeal Sparing Surgery (Anderson Technique)?
The risks associated with the procedure include:
- Disturbance of the physis due to technical difficulties that may lead to growth disturbances
- Rupture of reconstructed ACL due to increased stress on the graft
- Scar tissue formation restricting joint movement
Recovery following Physeal Sparing Surgery
Rehabilitation is important to help you return to your regular activities and sports. You will work with a therapist to help you safely achieve these goals. You will have to adhere to certain activity limitations for a while. Therapy is initiated within 1-2 weeks following surgery and will focus on improving range of motion and strength. As you progress with therapy the focus shifts towards improving balance and neuromuscular control. At 3 months, you should be able to jog and sports specific training can safely be introduced after 6 months. Special training to optimize movement patterns during athletics can help prevent ACL injuries.