function this_is_the_function_with_the_code{
  //call the normal function
  $output = theme_views_handle_field($fields, $field, $data);
  params: length, wordsafe?, dots?
  return 'truncate_utf8($output, 60, FALSE, TRUE)';
}

function theme_views_handle_field_clinical_node_title($fields, $field, $data) {
  return this_is_the_function_with_the_code($fields, $field, $data)
}