[Pseudarthrosis after bony avulsion fracture of the posterior cruciate ligament]

Tibial bony avulsion fractures of the posterior cruciate ligament (PCL) are rare injuries and in certain cases a delayed healing or non-union can occur under conservative treatment.

Presentation of the clinical result of patients with pseudarthrosis who were secondarily operated on after bony avulsion of the PCL.

The study included all patients who were operated on since 2010 for reasons of delayed or non-union PCL avulsion fracture in this clinic. Standardized questionnaires and follow-up documentation, e.g. visual analog scale (VAS), International Knee Documentation Committee (IKDC), Lysholm and Tegner scores were used and a magnetic resonance imaging (MRI) monitoring of the injured knee was carried out.

A total of 5 patients aged from 30 to 63 years (3 male, 2 female) were identified with mainly persisting flexion pain and instability under conservative treatment and secondary surgery of the knee. In the follow-up of 4 patients good results could be achieved (IKDC health condition 81/subjective assessment 76) after minimally invasive direct screw reduction with consolidation of the fracture zone; however, there was a slight residual dorsal instability.

The secondary operative treatment of pseudarthrosis of bony PCL injuries led to good clinical results. Due to the detectable residual instability the authors are of the opinion that the indications for primary osteosynthesis in the acute phase should be generously considered. This must still be corroborated in studies with larger case numbers.

The indications for MRI diagnostics should be generously considered, Smoking appears to be associated with an increased risk of pseudarthrosis. Good results can be achieved with a minimally invasive posterior screw approach, even after a delay.