PCL is the primary restraint to posterior drawer and secondary restraint to external rotation. This information is critical for diagnostic purposes, as well as for the restoration of normal knee stability after PCL injury.
Posterior cruciate ligament injuries may be classified with respect to timing (acute versus chronic) and severity of injury (isolated or combined), and both variables will directly affect the treatment and prognosis. Generally speaking, isolated PCL injuries may be treated nonoperatively and have an excellent prognosis. Combined ligament injuries involving the PCL, however, have a more guarded prognosis. In general, surgical repair or reconstruction in combined injuries within the first 3 weeks has superior results to conservative management.
Hyperflexion of the knee, the most common mechanism for an isolated PCL injury. A patient who is seen with a swollen, painful knee after a traumatic incident in which one cannot perform a complete examination should have a PCL injury ruled out by other diagnostic techniques (for example, MRI). The patient will usually also have discomfort with flexion and the posterior drawer examination will be relatively straightforward with a positive posterior tibial subluxation of various degrees.
A key point from the initial examination is that involvement of the posterolateral corner must be ruled out. Making the diagnosis of a so-called isolated PCL injury, when in fact the posterolateral corner is involved, will lead the clinician down the wrong path. If the surgeon only reconstructs the PCL in the presence of an involvement of the posterolateral corner, increased forces may be experienced by the PCL graft and subsequent graft failure may occur.
Surgical approach to the PCL is usually guided by arthroscopy
A variety of graft choices exist for PCL surgery. With respect to autologous tissue, the most popular graft choice is bone-patellar tendon-bone. Quadruple hamstring tendons offer an alternative graft choice with less graft site morbidity. However, graft fixation is inferior to bone-patellar tendon-bone and Achilles tendon. Autologous quadriceps tendon offers another option that has less graft site morbidity than bone-patellar tendon-bone.