title: Influence of surgical approach on heterotopic ossification after total hip arthroplasty - is minimal invasive better? A case control study.
abstract: Heterotopic ossification (HO) is a well-known complication after total hip arthroplasty (THA). Recently, the trend is to operate THA minimally invasive being less traumatic than standard approaches and promising a faster return to activity. The purpose of the study was to investigate if minimal invasive surgery (MIS), leads also to less HO after THA.
  
  
  
  This retrospective study included 134 consecutive patients undergoing THA. In 42 (31.3%) patients a standard modified anterolateral (STD-Watson-Jones), in 28 (20.9%) patients a standard transgluteal Bauer approach (STD-Bauer), in 39 (29.1%) a MIS direct anterior approach (AMIS) and in 25 (18.7%) patients a MIS anterolateral (MIS-AL) approach was used. Standard preoperative anterior-posterior and lateral radiographs were assessed for occurrence of HO. HO was classified according to Brooker. In addition, short- and long-term adverse events were noted. Data was statistically analyzed using Chi-square tests, analysis of variance, multivariate data analysis and Pearson's correlation (p < 0.05).
  
  
  
  Overall, HO was found in 38 caucasian patients (28.4%) after THA. The STD-Watson-Jones group showed the highest HO rate (45.2% n = 19) with a significant difference to the AMIS (23.1% n = 9) and STD-Bauer approach (14.3% n = 4). No statistical difference was found to the MIS-AL approach (24.0% n = 6). Postoperative complications did not differ significantly except for a higher incidence of Trendelenburg`s sign in STD-Bauer.
  
  
  
  The rate and degree of HO after THA were significantly different with regards to the surgical approach. The standard modified anterolateral approach resulted in the highest HO rate, however, MIS approaches showed higher HO rates than the STD-Bauer.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland (Bruderholz, Liestal, Laufen), CH-4101, Bruderholz, Switzerland.|University of Basel, Basel, Switzerland.
authors.forename: Maya
authors.initials: M
authors.lastname: Hürlimann
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland (Bruderholz, Liestal, Laufen), CH-4101, Bruderholz, Switzerland.|University of Basel, Basel, Switzerland.
authors.forename: Filippo-Franco
authors.initials: FF
authors.lastname: Schiapparelli
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland (Bruderholz, Liestal, Laufen), CH-4101, Bruderholz, Switzerland.|University of Basel, Basel, Switzerland.
authors.forename: Niccolo
authors.initials: N
authors.lastname: Rotigliano
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland (Bruderholz, Liestal, Laufen), CH-4101, Bruderholz, Switzerland.
authors.forename: Enrique
authors.initials: E
authors.lastname: Testa
authors.affiliation: Amsler Consulting, CH-4059, Basel, Switzerland.
authors.forename: Felix
authors.initials: F
authors.lastname: Amsler
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland (Bruderholz, Liestal, Laufen), CH-4101, Bruderholz, Switzerland. michael.hirschmann@ksbl.ch.|University of Basel, Basel, Switzerland. michael.hirschmann@ksbl.ch.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Hirschmann
mesh_terms: D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D009999:Ossification, Heterotopic / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology*; D012189:Retrospective Studies
keywords: Anterolateral minimal invasive approach; Direct anterior approach; Heterotopic ossification; Periarticular ossification; THA; Total hip arthroplasty; Transgluteal Bauer; Watson-Jones