Arthroscopic Reconstruction of the Anterior Cruciate Ligament of the Knee: Is There a Difference in Single Bundle or Double Bundle?
The anterior cruciate ligament in the knee joint is an important structure for knee stability. It serves to prevent excessive forward translation and internal rotation of the tibia during activities. Injury to the anterior cruciate ligament is the most common ligament injury. It often occurs in sports like soccer, basketball and skating, or activities that demand agility, speed, frequent cutting and turning. Patient often hears a pop sound from the injured knee at the time of injury, sudden severe knee pain and usually cannot continue with the game. Swelling of the knee follows and the patient experiences weakness, instability and easily giving way on the knee.
Arthroscopic reconstruction of the Anterior Cruciate Ligament is the current standard and is replacing open ligament reconstruction. The surgery is to take some dispensable tendon segments from around the knee, fixing one end to the distal femur and the other end to the proximal tibia inside the knee joint with the help of the knee arthroscope.
Most of the patients can return to sport activities after the procedure. There are however, about 10 to 15 % of patients experienced some degree of instability after the procedure. Current literature suggested that the functional anatomy of the anterior cruciate ligament might be separable into 2 components, the anteromedial band, responsible for holding the tibia back and the posterolateral band for preventing excessive tibial internal rotation. Most reconstruction is in tended to reconstruct the anteromedial band (Single Bundle) only. For some indicated patients, now we may consider reconstructing both anteromedial and posterolateral bands (Double Bundle) in order to similate the natural anterior cruciate ligament in anatomy and function.
However, it is not certain whether double bundle reconstruction of the ligament is the only definitive answer for all the knee instability after anterior cruciate ligament injury. Further refinement of anterior cruciate ligament reconstruction may be achievable with the advance and development of arthroscopic surgery.
Dr. CHAN, Wai-lam