Judet T, Massin P, Bayeh P J
Service de Chirurgie Orthopédique et Traumatologique, Hôpital Tenon, Paris.
Rev Chir Orthop Reparatrice Appar Mot. 1994;80(2):123-30.
In recent traumatology (complex radial head fractures with severe sprain of the medial collateral ligament), as well as in sequellae (extensive release for severe elbow stiffness), the implantation of a radial head prosthesis may be necessary to stabilize the humero-ulnar joint and the radial shaft. Its major advantage consists of allowing immediate postoperative mobilization. Swanson first proposed a silastic replacement of the radial head which turned out to have serious mechanical and biological disadvantages.
We propose a new Titanium implant, which is stiffer, and made of 2 parts connected by a spherical joint, thus maintaining an optimum congruence between the prosthetic component and the humeral condyle in any position of the joint (flexion/extension or pronosupination). This prosthesis was implanted in 4 recent fractures and reviewed after an average follow-up of 23 months [12-36].
Results were excellent in 2 cases, and good in 1 case: functional assessment was fair in the last case, in which the initial lesion consisted of a complex ulnar fracture associated with a Mason 3 fracture of the radial head. An osteosynthesis of the ulnar shaft and olecranon had preceeded implantation of the radial head prosthesis. In 5 additional cases with severe posttraumatic elbow stiffness, the prosthesis was implanted during elbow release, regularly allowing durable stabilization of the joint in an anatomic position, and in 2 of these cases, permanent correction of the radio-ulnar index. In these last cases, proximal migration of the radial shaft had occurred after resection of the radial head. In one case, this migration had resulted in ulnar fusion complicating a Sauve-Kapandji procedure. In the other case, proximal migration of the radius had resulted in painful distal radio-ulnar dislocation. In this second group, patients were followed-up an average of 31 months [12-46]. No complication has yet been recorded (no osteolysis, no stem breakage, no wear, no loosening).
Indications for implantation of a radial head prosthesis were deduced from these observations: in recent trauma, implantation of the prosthesis should only be indicated in those fractures, in which osteosynthesis appears not to be possible (Mason 3 or 4), with the following associations: radial head fracture with severe sprain of the medical collateral ligament--patients with positive radio-ulnar index--extensive lesions of the interosseous membrane (Essex-Lopresti, or Monteggia affecting the ulnar shaft)--associated fracture of the proximal ulna (olecranon, coronoid process...). In sequellae, we propose the following indications: extensive elbow release compromising elbow stability--painful inferior radio-ulnar dislocation complicating resection of the radial head--valgus instability complicating radial head resection.
在近期创伤学领域（伴有内侧副韧带严重扭伤的复杂桡骨头骨折）以及后遗症方面（为严重肘关节僵硬进行广泛松解时），可能需要植入桡骨头假体以稳定肱尺关节和桡骨干。其主要优点是允许术后立即活动。斯旺森首先提出用硅橡胶替代桡骨头，但结果显示存在严重的机械和生物学缺陷。
我们提出一种新型钛植入物，其硬度更高，由通过球形关节连接的两部分组成，从而在关节的任何位置（屈伸或旋前旋后）都能使假体部件与肱骨髁保持最佳的一致性。该假体植入了4例近期骨折患者体内，并在平均随访23个月[12 - 36个月]后进行评估。
2例结果优秀，1例良好：最后1例功能评估为尚可，其初始损伤为复杂尺骨骨折合并桡骨头梅森3型骨折。在植入桡骨头假体之前已对尺骨干和鹰嘴进行了骨接合术。另外5例严重创伤后肘关节僵硬患者，在肘关节松解时植入了假体，通常能使关节在解剖位置持久稳定，其中2例桡尺指数得到永久性矫正。在这些最后病例中，桡骨头切除后桡骨干发生了近端移位。1例中，这种移位导致尺骨融合，使Sauve - Kapandji手术复杂化。另1例中，桡骨近端移位导致疼痛性下尺桡关节脱位。在这第二组患者中，平均随访31个月[12 - 46个月]。尚未记录到并发症（无骨质溶解、无柄部断裂、无磨损、无松动）。
从这些观察结果中得出了桡骨头假体植入的指征：在近期创伤中，假体植入仅适用于那些似乎无法进行骨接合术的骨折（梅森3型或4型），伴有以下情况：桡骨头骨折合并内侧副韧带严重扭伤——桡尺指数阳性的患者——骨间膜广泛损伤（埃塞克斯 - 洛普雷斯蒂损伤，或影响尺骨干的孟氏骨折）——近端尺骨相关骨折（鹰嘴、冠状突……）。在后遗症方面，我们提出以下指征：广泛的肘关节松解影响肘关节稳定性——桡骨头切除术后疼痛性下尺桡关节脱位——桡骨头切除术后外翻不稳定。
