Contrast-Enhanced Ultrasound: A Viable Diagnostic Tool in Predicting Treatment Failure after Non-union Revision Surgery for Upper- and Lower-Limb Non-unions.

Non-unions remain a major complication in the treatment of long-bone fractures and affect quality of life considerably. Both early detection and treatment of non-unions are essential to secure subsequent fracture union. Sufficient vascularization plays a key role in the healing process. The aim of this prospective study was to quantify the microperfusion within non-unions by means of contrast-enhanced ultrasound (CEUS) as early as 12 wk after non-union surgery and to examine the prognostic capability of CEUS in predicting treatment failure. Among 112 patients who had undergone non-union surgery, consolidation within 36 mo was achieved in 89 patients ("responders"), whereas 23 patients showed persistent non-unions ("non-responders") and required further surgery. CEUS quantification parameters such as peak enhancement, wash-in area under the curve and wash-in perfusion index revealed significantly higher perfusion levels in "responders" compared with "non-responders" (p < 0.05). Receiver operator characteristic curve analysis revealed that persistent fracture non-unions could be predicted with a sensitivity/specificity of 88.7%/72.2% in lower-limb non-unions and a sensitivity/specificity of 66.7%/100.0% in upper-limb non-unions. CEUS is a suitable diagnostic tool in predicting treatment failure as early as 12 wk after non-union surgery and should be integrated into the clinical routine when deciding on revision surgery at an early stage.

Differences in gait analysis and clinical outcome after TightRope® or screw fixation in acute syndesmosis rupture: study protocol for a prospective randomized pilot study.

BACKGROUND: Ankle sprains and fractures are most common injuries in orthopedic and trauma surgery. The concurrent occurrence of syndesmosis ruptures in these injuries represents a more complex problem, as they often remain undetected. A proper and accurate treatment of injuries of the syndesmosis, both isolated and combined with fractures, is necessary to avoid long-term consequences (chronic instability, cartilage damage, and post-traumatic osteoarthritis). The most popular treatment option is a static screw fixation and the newly developed dynamic TightRope® (Arthrex, Naples, FL, USA). The aim of this pilot study is to compare monitor ankle range of motion and maximum ankle power in gait as functional outcome parameters of instrumented gait analysis, as well as clinical and radiographic outcome for assessing the stabilization of acute syndesmosis rupture with either a static implant (a 3.5 mm metallic screw) or a dynamic device (TightRope®). METHODS: This prospective, randomized, controlled, clinical trial will be carried out at the Center for Orthopedics, Trauma Surgery and Spinal Cord Injury of the University Hospital Heidelberg. Adult patients, who suffer from an acute syndesmosis rupture, both isolated and in combination with fractures of the lateral malleolus (Weber C and Maisonneuve fractures) and who are undergoing surgery at our trauma center will be included in our study. The patients will be randomized to the different treatment options (screw fixation or "TightRope®"). Subsequent to the surgical treatment, all patients will receive the same standardized follow-up procedures including a gait analysis and MRI of the ankle at 6 months follow-up. The primary endpoint of the study is the successful healing of the syndesmosis and biomechanical investigation with gait analysis. DISCUSSION: The results of the gait analysis from the current study will help to impartially and reliably evaluate the clinical and biomechanical outcome of both treatment options of acute syndesmosis ruptures. We hypothesize that the dynamic fixation provides an equivalent or better biomechanical, clinical, and radiographic outcome in comparison to the screw fixation. TRIAL REGISTRATION: German Clinical Trials Register (DRKS) DRKS00013562 . Registered on July, 12, 2017.