Evaluation and treatment of recurrent instability after anterior cruciate ligament reconstruction.

Revision ACL surgery has become increasingly common. Successful revision surgery requires a thorough preoperative evaluation, including a detailed history and a physical and radiographic examination. Preoperative planning is imperative for a successful outcome, as it limits the potential for repeating the errors that led to the failure of the primary procedure. This begins with a determination of the mechanism of failure. Often, a primary as well as a secondary cause of failure can be identified. Determination of the etiology of failure is the first step in a carefully constructed treatment plan, which includes the type of revision and skin incision, graft and hardware removal, tunnel placement, graft selection and fixation, and the rehabilitation protocol. The preoperative plan should have enough flexibility to accommodate unanticipated findings in the operating room. Finally, the importance of counseling the patient preoperatively regarding potential results must be emphasized. Given the complexity of revision ACL reconstruction, the patient's expectations must be adjusted to realistically match the potential for success. The goal of successful revision surgery may be only to return the patient to activities of daily living or work, especially if there is evidence of degenerative joint disease. With proper planning and attention to detail, revision ACL surgery can provide a satisfying solution to difficult cases of knee instability.

Internal derotation osteotomy of the tibia: pre- and postoperative gait analysis in persons with high sacral myelomeningocele.

Rotational deformities of the lower extremities are common in patients with myelomeningocele. In these situations, surgical correction is often necessary. We conducted a retrospective review of eight ambulatory patients with high sacral myelomeningocele and external tibial torsion who underwent 10 distal tibia and fibular internal derotation osteotomies. All patients had an increased valgus knee stress preoperatively. Pre- and postoperative three-dimensional gait analysis was used to evaluate coronal plane knee moments and dynamic sagittal plane knee motion. Postoperatively, a significant improvement in the abnormal internal knee varus moment (p < 0.005) as well as a significant increase in the stance phase knee extension (p < 0.01) was seen. Three patients had resolution of preoperative knee pain. We believe that patients with increased knee stress secondary to excessive external tibial torsion will benefit from a tibial derotation osteotomy that could delay or prevent the onset of late degenerative changes about the knee.