title: Contra-lateral hip fracture in the elderly: are decreased body mass index and skin thickness predictive factors?
abstract: A correlation between soft tissue thickness and osteoporosis has been suggested. We aimed to estimate if a low body mass index (BMI) and/or a decrease of skin thickness could estimate the risk of contra-lateral hip fracture.
  
  
  
  First, we performed a retrospective analysis of 1268 patients treated for a hip fracture. The 146 patients who had a contra-lateral hip fractures-study group-were compared with the 1078 patients who did not-control group. Four BMI categories were considered: obese, overweight, normal weight and low weight. Second, we enrolled prospectively 1000 consecutive patients in the emergency department. History of fractures, BMI, and skin aspect on the dorsum of both hands-classified as severe decrease thickness, moderate decrease thickness or normal-were recorded.
  
  
  
  pt?>In the first part, we found that patients with contra-lateral fractures had a significantly lower BMI than those in the control group (22.2 Vs 26.5 kg/m2, p = 0.01). In the second part, 48 on 1000 patients had a hip fracture. Among them, six had a contra-lateral fracture. BMI was 23.4 kg/m2in bilateral hip fractures, 33.68 kg/m2in the unilateral fracture group, and 28.04 kg/m2in the non-fracture group (p = 0.04). Finally, patients with contra-lateral hip fractures had a severe decrease thickness of the skin.
  
  
  
  A low BMI and a decreased skin thickness increase independently the risk of fractures by three times. When associated, they increase the risk of fracture risk by five times. This combination had a sensitivity at 71 % and a specificity at 90 % for predicting hip fracture.
authors: Department of Orthopedic, Trauma and Reconstructive Surgery, Antoine Béclère Hospital, AP-HP, Paris Sud University, 157 rue de la Porte de Trivaux, 92140, Clamart, France. aureganjc@yahoo.fr.|Laboratory of Tribology and System Dynamics (LTDS - UMR CNRS 5513), Ecole Centrale Lyon, 36 avenue Guy de Collongues, 69134, Ecully, France. aureganjc@yahoo.fr.|Laboratory of Bioengineering and Bioimaging for Bone and Articulation (B2OA - UMR CNRS 7052), Paris-Diderot University, 10 avenue de Verdun, 75010, Paris, France. aureganjc@yahoo.fr.
authors: Jean-Charles
authors: JC
authors: Aurégan
authors: Department of Orthopedic, Trauma and Reconstructive Surgery, Antoine Béclère Hospital, AP-HP, Paris Sud University, 157 rue de la Porte de Trivaux, 92140, Clamart, France.
authors: Aurélien
authors: A
authors: Frison
authors: Department of Orthopedic, Trauma and Reconstructive Surgery, Antoine Béclère Hospital, AP-HP, Paris Sud University, 157 rue de la Porte de Trivaux, 92140, Clamart, France.
authors: Thierry
authors: T
authors: Bégué
authors: Laboratory of Bioengineering and Bioimaging for Bone and Articulation (B2OA - UMR CNRS 7052), Paris-Diderot University, 10 avenue de Verdun, 75010, Paris, France.|Department of Orthopedic Surgery and Traumatology, Lariboisière Hospital, AP-HP, Paris-Diderot University, 2 Rue Ambroise Paré, 75010, Paris, France.
authors: Didier
authors: D
authors: Hannouche
authors: Laboratory of Tribology and System Dynamics (LTDS - UMR CNRS 5513), Ecole Centrale Lyon, 36 avenue Guy de Collongues, 69134, Ecully, France.
authors: Catherine
authors: C
authors: Bosser
authors: Laboratory of Bioengineering and Bioimaging for Bone and Articulation (B2OA - UMR CNRS 7052), Paris-Diderot University, 10 avenue de Verdun, 75010, Paris, France.
authors: Morad
authors: M
authors: Bensidhoum
authors: Laboratory of Tribology and System Dynamics (LTDS - UMR CNRS 5513), Ecole Centrale Lyon, 36 avenue Guy de Collongues, 69134, Ecully, France.
authors: Thierry
authors: T
authors: Hoc
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D006620:Hip Fractures / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D010024:Osteoporosis; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D013851:Thinness / Q000150:complications*
keywords: Body mass index; Contra-lateral hip fracture; Skin thickness; Soft tissue thickness