LF is the favorite option, independent of the Tubiana stage. PNF is being chosen mainly in stages I and II. “Other” summarizes all other treatments that are not CCH, PNF, or LF, e.g., dermofasciectomy. More than 40 % of the surgeons are not treating patients with stage I at all (Fig. 3.1).

One surgeon stated that he treats only 2 cases per year; another one reported treating 400 cases per year. Since this represents a widespread of patient numbers, we defined a coefficient, derived from the number of patients in relation to the whole number of treatments (9,761), and calculated “weighted” treatment numbers.

Figure 3.2 indicates that surgeons treating larger numbers of patients prefer using PNF to a higher degree.

Interestingly, there is a homogenous distribution of case numbers within a subgroup of surgeons that treat up to 100 cases per year, while this is not true for the rest of the responders: those treating more than 100 cases form a heterogeneous group (Fig. 3.3). We therefore performed a subgroup analysis and compared a subset of 5,154 treatments performed by 86 surgeons, doing up to 100 treatments per year, with 4,607 treatments, performed by the remaining 24 surgeons.

The most impressive difference between both groups is in the comparison of preferred treatment options in Tubiana stage II: those performing more procedures favor PNF to a higher degree (Fig. 3.4). In other stages, preferences are very similar. Probably the higher number of PNF is among the reasons why the percentage of one-day cases is significantly higher in the group with more than 100 treatments per year (30.1 %) than in the other one (19.9 %).