A wealth of clinical and experimental data suggests, that anatomical restoration of the posterior calcaneal facet is a major predictor of outcome after intra-articular calcaneus fractures. The value of subtalar arthroscopy was examined in three clinical study groups (I-III.
Materials and methods: (I) The subtalar joint was inspected arthroscopically in 28 patients during hardware removal one year after open reduction and internal fixation (ORIF). This procedure was accompanied by subtalar arthrolysis in all cases. (II) Open subtalar arthroscopy was performed to evaluate the quality of reduction after ORIF of intra-articular calcaneus fractures in 59 cases. Arthroscopy was performed after seemingly exact reconstruction of the posterior facet as judged visually and fluoroscopically. (III) Arthroscopically assisted percutaneous reduction and screw fixation (PRSF) was performed in 18 patients with Sanders II fractures. Reduction was achieved with a Schanz screw introduced percutaneously into the tuberosity fragment and controlled fluoroscopically, while fine corrections were made under arthroscopic guidance.
Results: (I) Clinical results after ORIF of intra-articular calcaneus fractures were highly correlated to the degree of residual incongruities and chondromalacia of the posterior facet as seen arthroscopically during hardware removal (P < 0.01). (II) In 13 of 59 cases (22.0%) during ORIF despite seemingly accurate reduction, steps between 1-2 mm were detected arthroscopically in the posterior calcaneal facet and reduction was repeated subsequently in these cases. (III) Fifteen patients who underwent arthroscopically guided PRSF were re-evaluated after a minimum of one year with excellent clinical results (94.1 pts. with the AOFAS scales). No wound complications were seen.
Conclusions: Subtalar arthroscopy provides a most precise and thorough view of the posterior facet of the calcaneus both in assessing the quality of initial reduction as well as evaluation during hardware removal after intra-articular calcaneus fractures. It is more precise than intra-operative fluoroscopy and less time consuming than standard Brodén views during surgery. The use of arthroscopy allows anatomical percutaneous reduction and screw fixation of Sanders II fractures. It therefore provides a useful additional tool in treating intra-articular calcaneus fractures.