CASE REPORT S. Koe¨ter Æ C. J. M. van Loon Æ J. L. C. van Susante Lateral femoral condyle osteochondral fracture caused by a patella luxation: advantages and disadvantages of PLA fixation Received: 12 June 2005 / Accepted: 17 October 2005 / Published online: 19 November 2005 Ó Springer-Verlag 2005 Abstract A lateral patella luxation is occasionally com- plicated by an (osteo)chondral fracture. These fractures are usually located at the inferomedial part of the pa- tella. In this case report we describe an osteochondral fracture of the lateral femoral condyle after a dislocation of the patella. The latter is a more severe injury because it involves an important weight bearing part of the knee joint. Refixation of the osteochondral fracture should be pursued. Various surgical techniques using nonresorb- able materials have been described. We describe the advantages and disadvantages of refixation with biode- gradable pin fixation for an osteochondral fracture caused by a patellaluxation. Keywords Osteosynthesis Æ Fracture Æ Knee injuries Æ Patella Æ Surgery Æ Luxation Fracture oste´ochondrale du condyle femoral late´ral par luxation de la rotule Re´ sume´ Une luxation externe de la rotule est parfois complique´e par une fracture oste´ochondrale. Ces frac- tures sont habituellement localise´es dans la partie infe´ro- me´diale de la rotule. Dans notre cas clinique, nous de´ crivons une fracture oste´ ochondrale du condyle fe´moral externe apre`s luxation comple`te de la rotule. Cette dernie`re constitue un traumatisme plus se´ve`re car implique une importante composante de charge au ni- veau de l’articulation du genou. La refixation de la fracture oste´ochondrale devrait eˆtre re´alise´e. Diffe´rentes techniques chirurgicales utilisant des mate´riaux nonre´- sorbables ont e´te´ de´crites. Nous de´crivons les avantages et les inconve´ nients d’une technique utilisant une cheville biode´ gradable. Mots cle´s Oste´ osynthe` se Æ Fracture Æ Traumatismes du genou Æ Rotule Æ Patella Æ Chirurgie Æ Luxation Introduction Traumatic luxation of the patella is the most common cause of chondral and osteochondral fractures of the knee joint. The incidence of a chondral or osteochondral fracture after a patellaluxation has been estimated to be as high as 8.4% [12]. Three fracture types have been described: an inferomedial fracture, a lateral femoral condyle fracture and a combined ‘‘kissing’’ lesion [5]. Chondral and osteochondral fractures in the weight bearing part of the knee joint (i.e. the lateral femoral condyle) are relatively rare and can lead to the devel- opment of arthritis and disabling pain [11]. Isolated chondral fractures show no regeneration tendency due to the absence of vascularisation of the articular cartilage [4, 8, 9]. Osteochondral lesions show some regeneration capacity due to the perforation of the subchondral plate permitting bone marrow contact and pluripotent stem cells migration [11]. These cells induce repair of the articular surface with mechanically inferior fibrocartilaginous tissue [14]. Because this cartilage is mechanically inferior it will degenerate over time and can cause symptomatic osteoarthritis [14]. Patients pre- senting with a patella dislocation and a concomitant osteochondral fracture are often relatively young. To prevent the complications associated with chondral and osteochondral fractures, various surgical therapies have been described. If only the patellar cartilage is impaired surgical therapy can consist of a simple resection of the lose fragment. Osteochondral fractures of the lateral femoral condyle are more severe lesions. They require a more aggressive surgical approach because refixation must be pursued. There are no recent publications on the S. Koe¨ter (&) Æ C. J. M. van Loon Æ J. L. C. van Susante Department of Orthopaedic Surgery, Rijnstate Hospital Arnhem, Arnhem, The Netherlands Present address: S. Koe¨ter Department of Orthopaedic Surgery, St. Maartenskliniek, PO box 9011, 6500 GM Nijmegen, The Netherlands E-mail: s.koeter@maartenskliniek.nl Eur J Orthop Surg Traumatol (2006) 16: 268–270 DOI 10.1007/s00590-005-0053-0