There is no consensus regarding the best treatment method for displaced intra-articular calcaneal fractures—operative or conservative—nor the best surgical method. However, it is now widely agreed that the consequences of inadequately treated intra-articular calcaneal fractures can be disabling, including common persistent pain, a distorted hind foot morphology and a delayed return to work [5, 17, 20].
The dilemma of balancing soft tissue compromise with the need for anatomic reduction of the articular surface under direct vision is the whole problem. Several approaches and fixation methods have been described: lateral, medial, double-incision medial and lateral, sinus tarsi and extensile lateral approaches. Fixation modalities have included screws, locked anatomical plates and a specific nail, and some studies have reported using only Kirschner wires [1, 11, 20].
The extensile lateral approach has gained popularity in the last few decades; nevertheless, it has gained a bad reputation owing to wound complications at rates that reached up to 25% in some studies. Wound complications included deep infection, osteomyelitis, wound dehiscence and even amputation. Similar problems have been reported in studies that used double incision, but with a decreased (but still high) rate of wound compromise: 6%. Thus, trends towards minimally invasive approaches have gained some preference recently .
In a systemic review by Dingemans et al., it was revealed that different methods of fixation did not differ greatly, and that all methods used have similar rigidities and stabilities. Moreover, they stated that anatomical locked plates that need an extensile approach and maximum soft tissue compromise have no advantage over the other methods described .
Although there is no consensus regarding the best fixation method for comminuted intra-articular calcaneal fractures, we have favored using only KWs, owing to some factors. Rigid fixation using screws to compress the articular surface has always been sought. Unfortunately, this is not always achievable in such complex and challenging fractures.
Most of our cases were high-energy traumas caused by a fall from height (40/46), with the majority being Sanders type 3 or 4 (32/56). Comminuted calcaneal fractures were commonly associated with rupture of the lateral cortical wall, alongside a lack of structural support of the subchondral cancellous bone, which was usually impacted, rendering a big cavity underneath a small articular fragment. We had concerns that using screws in such comminuted unsupported small fragments would not only lead to weak and doubtful purchase but might also split those fragments into more comminuted ones.
On the other hand, using KWs gave us the advantage of supporting each individual fragment, which might not be possible with screws. Using KWs allowed us to transfix those small articular fragments to the talus, giving more support. In addition to a shorter operative time, this avoids the problem of prominent metal, which is not uncommon after calcaneal fixation, and allows easy removal as part of the outpatient follow-up.
The ideal treatment method seems to have minimal soft tissue compromise, restores the general hind foot morphology, reduces the calcaneal articular surface under direct vision, and has stable fixation. In our study, we used a limited sinus tarsi approach to reduce the articular surface of the posterior facet under direct vision. Even articular fragments of the medial part of the posterior facet were accessed and reduced using the same incision. We used KWs to transfix the articular surface to the talus. This was stable, with no cases of a loss of reduction observed in the follow-up.
The operative time ranged from 30 to 45 min, which was much less than the 120 min needed in the extensile approach  and the 60 min needed in a study that used a minimally invasive approach .
At the final follow-up, the mean AOFAS score was 78.4, which was comparable to results achieved by open reduction through the extensile lateral approach or double-incision approach, in addition to previous studies using minimally invasive fixation through the sinus tarsi approach [11, 15, 26]. It should also be taken into consideration that we treated all Sanders groups, including high-risk diabetic and smoker patients, unlike other studies that treated specific Sanders groups and excluded high-risk patients . Moreover, it was found that there is no statistically significant relationship between the Sanders classification and the overall AOFAS score. The lowest AOFAS scores were attributed to some factors: smoking and delay before surgery. Bilateral cases also scored less than unilateral cases, but it should be noted that bilateral fractures are caused by higher-energy trauma, so they are commonly accompanied by spinal or other fractures; also, the lack of a healthy contralateral calcaneus can augment the functional loss in comparison to unilateral cases.
We adopted the AOFAS score in addition to radiographic evaluation as the study then included different types of clinical assessment. Depending solely on radiographic evaluations of Bohler’s angle and the angle of Gissane did not seem to be a fair evaluation . We emphasized that restoration of the general hind foot morphology is as important as the reduction of the calcaneal articular surface and angles . Clearly, this can explain the fact that many patients have radiographic evidence of subtalar degenerative joint disease yet are clinically asymptomatic. This can explain our results: at the final follow-up, 19 patients had radiographic evidence of degenerative joint disease, but only 9 patients were symptomatic.
We had eight cases of infection: a rate of 14%, which is still lower than in studies which used the extensile lateral approach and the double-incision approach, where the infection rates reached up to 40% .
Our decision not to use a bone graft is supported by many previous studies. A previous cadaveric study of 14 cadaveric calcanei revealed that there was physiological cavitation under the thalamic portion, which corresponded to the neutral triangle, in 40% of the specimens. In 60% of the specimens, there were sparse bone trabeculae [24, 25].
Unlike other studies that used the same technique, we supported the evaluation of our results by performing CT at the 1-year follow-up. We also treated all fracture types and all patients using the same technique. Nonetheless, this study has some limitations, as we lacked a control group, and this is a technically demanding surgery with a high learning curve.
Considering our results, we believe that the limited sinus tarsi approach for open reduction and percutaneous KW fixation expands the indications of surgery for displaced intra-articular calcaneal fractures with fewer treatment-related complications. This approach allows reduction under direct vision while maximally preserving the soft tissue envelope.
Clinical and radiological assessment seems to be promising and can be used for future randomized controlled trials or prospective cohort studies that focus on the same or similar conditions.