Posterolateral Corner Reconstruction Using Hamstrings Grafts - A Comparative Biomechanical Study Including a Novel Technique
M.B. Mestriner, S. Nejima, P.B. Bartolin, R.D.P.L. Cury, N.R. Severino, A.A. AmisObjective:
To compare three posterolateral corner (PLC) reconstruction techniques - the popliteofibular loop (a recently described technique), the modified LaPrade and modified Arciero - in restoring knee laxity in varus, external rotation and posterior translation.
Methods:
Nine cadaveric knees were subjected to varus (VR), external rotation (ER), posterior tibial translation (PTT) and ER+PTT loads, from 0 o to 100 o degrees of flexion, in different conditions: intact state, then PLC injured, and finally with PLC reconstructed. All specimens were submitted to three PLC reconstruction techniques, in varying order: the popliteofibular loop (MM), the modified LaPrade (LP) and the modified Arciero (AR). Hamstrings tendon grafts (gracilis and semitendinosus) were used in all reconstructions, removed from each specimen.
Results:
With varus loading, LP failed to restore intact laxity across 0 o -20 o flexion; when comparing the three techniques, MM and AR were more effective than LP across 50 o -100 o (p<0.05). With ER loading, the three techniques restored intact knee laxity; the MM technique allowed significantly less ER than the native knee from 30 o to 100 o (p<0,05). Regarding PTT, no difference was observed between techniques. With combined ER + PTT load, no difference was observed among the three techniques regarding PTT, but LP failed to restore ER at 0 o , while MM overconstrained ER across 60 o to 100 o (p<0,05).
Conclusion:
No significant differences were observed between MM and AR in restoring knee laxity in an isolated PLC knee injury, both being more effective than LP, specifically when VR and ER+PTT loads were applied.