Is the Any Clinical Importance for Separation Congenitally Dislocated Hip in Adults into Types C1 and C2 by Hartofilakidis?

The main questions of the study: 1) is there any difference in anatomical features between subtypes C1 and C2 of high hip dislocation by Hartofolakidis classification; 2) are the conditions for performing the THA different and what are the surgical decisions; 3) what are the THA results in different groups? Materials and Methods. In a single center study the authors retrospectively evaluated the outcomes of 561 THAs performed in 349 patients with a high hip dislocation including 32 men (9.2%) and 317 women (90.8%) with the follow up from 12 to 188 months (average 69,4 months). In 326 cases (58.1%) the dislocation was assessed as type C1, and in 235 cases (41.9%) — as type C2. The average age of the patients at the time of surgery was 47.6 (19 to 74) years, for men — 39.1 years and 48.1 years for women. Results. Paavilainen shortening osteotomy was performed in 100% of patients with type C2 and only in 50.6% of patients with type C1, p<0.001. The cup was implanted into the true acetabulum cavity in 99.1% of cases with type C2, and for type C1 only in 69.0% of cases, p<0.001. Lateral under-coverage of the cup in patients with type C2 required supplementing by femoral head autograft only in three cases, and for type C1 — in 18 patients, p = 0.009. In the group of C2, the mean length of the osteotomized fragment of the proximal femur was 78.6 mm compared to 62.5 mm in patients with type C1. This provided a better contact area between the greater trochanter and the femur and in 92.8% of cases fixation was done by cerclage wires and two screws. In the group of patients with type C1, this option was feasible only in 60.0% of cases. Odds ratio (OR) for fixation of the greater trochanter by a special plate for primary indications in patients with type C1 were 10 367, p = 0.008. Harris Hip score improved averaged from 39.5 points to 83.6, without statistically significant differences between groups of C1 and C2. Early complications included 9 dislocations (1.6%), 8 cases of femoral nerve neuropathy (1.4%) and 3 early infections (0.5%). No cases of sciatic nerve paresis were observed. Non-union of the greater trochanter was observed with almost equal frequency in patients with C1 and C2 types, and revision fixation was needed in 27 patients (6.8%). Revision arthroplasty was performed in 22 cases (3.9%) due to 4 infections, 2 aseptic loosening of the stem, 11 aseptic loosening of the acetabular component and 5 recurrent dislocations. Conclusion. The group of patients with high hip dislocation is very heterogenic in terms of severity of anatomical changes and demands different surgical tactics. Hartofolakidis classification helps the surgeon to select the best type of the surgical procedure, minimize the mistakes and predict treatment outcomes.