title: Minimally invasive plate osteosynthesis with PHILOS plate for proximal humerus fractures.
abstract: OBJECTIVE
  The aim of the present study was to evaluate results, including clinical and radiological outcomes and number of complications, following minimally invasive plate osteosynthesis (MIPO) of proximal humerus fractures, using the PHILOS® proximal humerus internal locking system (Synthes Holding AG, Solothurn, Switzerland).
  
  
  METHODS
  Retrospectively evaluated were 31 patients treated with MIPO (12 male, 19 female; average age: 58.4 years). Four patients had 2-part fractures, 14 patients had 3-part fractures, and 13 patients had 4-part fractures, according to Neer classification. Healing, complications, and head-shaft angle (HSA) were radiographically evaluated. Clinical outcomes were assessed at 1-year follow-up with Constant score.
  
  
  RESULTS
  Average Constant scores for fractured and normal shoulders were 73.2 ± 10.9 and 84.8 ± 5.1, respectively. Varus progression, fracture type, and age had no significant effect on functional outcome. Average postoperative and follow-up HSA's were 130.80 ± 7.70 and 128.80 ± 10.00, respectively. Significant varus progression was observed during follow-up (p = 0.01). Varus progression was more prominent in patients with postoperative HSA < 130° (p < 0.001). Inferomedial calcar screw usage, fracture type, and age had no significant effect on varus progression. Complications included 2 implant failures, 1 case of avascular necrosis (AVN), 1 primary screw cut-out, 1 axillary nerve injury, and 1 radial nerve injury (22.6% overall).
  
  
  CONCLUSIONS
  MIPO is a safe and effective option for the treatment of proximal humerus fractures, with good functional recovery and fewer complications, which are typically technique dependent. Reduction may be difficult, resulting in varus progression. Another disadvantage is risk of axillary nerve injury. Careful surgical technique and correct implant selection is important in the prevention of nerve injury.
  
  
  METHODS
  Level IV, Therapeutic study.
authors.affiliation: Private Çankaya Hospital, Ankara, Turkey. Electronic address: ugurgonc@hotmail.com.
authors.forename: Uğur
authors.initials: U
authors.lastname: Gönç
authors.affiliation: Private Çankaya Hospital, Ankara, Turkey. Electronic address: mesutatabek@yahoo.com.
authors.forename: Mesut
authors.initials: M
authors.lastname: Atabek
authors.affiliation: Private Çankaya Hospital, Ankara, Turkey. Electronic address: kursatteker@gmail.com.
authors.forename: Kürşat
authors.initials: K
authors.lastname: Teker
authors.affiliation: Private Çankaya Hospital, Ankara, Turkey. Electronic address: altugtanriover@gmail.com.
authors.forename: Altuğ
authors.initials: A
authors.lastname: Tanrıöver
mesh_terms: D001860:Bone Plates; D001863:Bone Screws; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D017102:Fracture Healing; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D011859:Radiography / Q000379:methods; D020127:Recovery of Function; D012189:Retrospective Studies; D012784:Shoulder Fractures / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D014421:Turkey
keywords: Complication; Minimally invasive plate osteosynthesis; Proximal humerus fracture