Sind höhere Preise für größere Kopfdurchmesser in der Hüftendoprothetik medizinökonomisch vertretbar? Eine Analyse der Kosten und Effekte in Deutschland

Abstract

In total hip arthroplasty (THA), femoral head diameter has not been regarded as a key parameter which should be restored when reconstructing joint biomechanics and geometry. Apart from the controversial discussion on the advantages and disadvantages of using larger diameter heads, their higher cost is another important reason that they have only been used to a limited extent. The goal of this study was to analyse the price structure of prosthetic heads in comparison to other components used in THA. A large group of patients with hip endoprostheses were evaluated with respect to the implanted socket diameter and thus the theoretically attainable head diameter. The relative prices of various THA components (cups, inserts, stems and ball heads) distributed by two leading German manufacturers were determined and analysed. Special attention was paid to different sizes and varieties in a series of components. A large patient population treated with THA was evaluated with respect to the implanted cup diameter and therefore the theoretically attainable head diameter. The pricing analysis of the THA components of two manufacturers showed identical prices for cups, inserts and stems in a series. In contrast to this, the prices for prosthetic heads with a diameter of 36-44 mm were 11-50 % higher than for 28 mm heads. Identical prices for larger heads were the exception. The distribution of the head diameter in 2719 THA cases showed significant differences between the actually implanted and the theoretically attainable heads. There are proven advantages in using larger diameter ball heads in THA and the remaining problems can be solved. It is therefore desirable to correct the current pricing practice of charging higher prices for larger components. Instead, identical prices should be charged for all head diameters in a series, as is currently established practice for all other THA components. Thus when reconstructing biomechanics and joint geometry in THA, it should be possible to recover not only leg length, femoral offset and antetorsion of the femoral neck, but also to approximately restore the diameter of the femoral head and thereby optimise the functional outcome.

The impact of capsular repair on the risk for dislocation after revision total hip arthroplasty – a retrospective cohort-study of 259 cases

“…This mechanism seems to be one of the main factors, maybe even the leading factor, in the avoidance of THA dislocation [13, 35, 37–39]. This phenomenon has been described in detail by Prietzel et al [35, 38].…”

“…A combination of capsular repair and using a larger head size may restore physical joint stability on a larger scale, provided by the permanent hip-stabilizing effects of atmospheric pressure, which continuously acts on the cross-sectional area of the prosthetic head, if the joint is hermetically sealed by either the hip capsule or connective tissues in the plane of the hip joint capsule [13, 35, 37–39]. …”

Editorial für die Zeitschrift für Orthopädie und Unfallchirurgie

“…In der Arbeit von Grunert et al [4] wird der Einfluss der Preisgestaltung auf den Einsatz der verschiedenen Kopfgrößen bei der Implantation von Hüftendoprothesen untersucht. Da es erhebliche Abweichungen zwischen den real eingesetzten und den theoretisch bestmöglichen Köpfen gibt, empfehlen die Autoren, identische Preise für die unterschiedlichen Größen anzustreben.…”