Congenital or acquired recurvatum genu might be caused by bone and/or soft tissue disorders. In bone recurvation, tibial deformity is more common; femoral deformity has clinical and X-ray features that are less important and often unidentified. We found this type of deformity in only four of 40 cases of bone recurvation. Bone recurvation can follow a tibial or femoral fracture as well as injury with no X-ray signs. Some months later an anterior epiphysiolisis might be recognised on X-ray. This fact allows a retrospective diagnosis of fifth type Salter-Harris epiphysiolisis. Clinically a harmonious recurvatum genu would be recognised, which is difficult to distinguish from a capsulo-ligamentous disorder. According to a subjective profile, it is featured with no objective laxity. On X-rays there are no peculiarities in the anterior view, but on the lateral view femoral condylar flattening with anterior rotation, in particular in the lateral one, can be observed. It might be useful to compare the X-ray findings to define a geometrical point termed the femoral diaphysealintercondylar angle. This has been already described and is measured between two lines, one which represents the axes of the femoral shaft, the other one the Blumensaat line; in a normal knee this angle measures 33° (±3). In knees with femoral recurvation this is higher: in our four patients the range of the angle was 45°–58°. Procurving femoral osteotomy is the gold standard; in fact femoral closed wedge osteotomy allows a complete correction. Surgeons must avoid an overcorrection with subsequent femoral trochlear rotation and at the same time a tibial osteotomy must be avoided, which would lead to a double articular deformity, wherever it would fit with a capsulo-ligamentous recurvation.
Recurvatum genu can develop as a results of both chronic diseases “maladie des enfants alités” (Lefort), though rarely, and after trauma, which occurs more often. Surgical treatment might consist either in a de-epiphysiodesis according to Langenskield, when a bone bridge is present, or by Ilizarov technique, which allows a correction of segmentary shortening. This kind of trauma often occurs after bone growth has ceased and this is why in our study we performed osteotomies. Femoral osteotomies are all closed wedge procedures with medial access and 90° angle blade-plate fixation. This allows early mobilisation and avoids overcorrection. Without performing this kind of procedure posteriorisation of the trochlea might occur and, consequently, over time, patellofemoral arthritis could develop. For the tibia we applied an anterior open wedge osteotomy with ATT avulsion, according to Lecuire, with which secondary low patella can be avoided. As fixation we first used screws, actually a plate to correct the co-existing valgus. The good results of this kind of surgery justify autologus bone graft. We have not employed the the procedure described by Bowen.
Tibial and femoral deformities might cause patellofemoral problems, but they do not have to be modified every time to obtain good results. We have evaluated external tibial rotation characterised by an external tibial deformity in varus, worsening in parallel feet position. In these patients the only surgical treatment is tibial osteotomy, justified by a positive effect on the knee joint mechanics. From 1990 to 2002 we performed 25 derotation tibial osteotomies as an isolated procedure or associated with a closed wedge osteotomy. We reviewed 15 patients (16–28 years old at surgery) with special reference to pain, aesthetic criteria and functional assessments, and we reported possible negative effects of derotation (recurvation and external tibial rotation). In all the patients we found an external rotation higher than standard range and moderate varus. All patients had remission of pain; this was complete in five and partial in six. Ten patients showed an increased tibial rotation and eight of those showed even recurvation without functional sequelae. At 2–12 years of follow-up, our results are satisfactory.
