Introduction: A femoropatellar syndrome may be caused by a deformity in the torsional axis of the femur or the tibia. The two cardinal symptoms are anterior knee pain and patellar instability.
Methods: We retrospectively evaluated 32 torsional osteotomies. The aim of the study was to prove that a torsional osteotomy could bring about significant pain relief and create a stable femoropatellar joint. Besides clinical and radiographic analysis of leg geometry, a computed-tomography-based measurement of the torsional angle was performed. The mean duration of follow-up was 37 months.
Results: The follow-up examination included VAS, the Japanese Knee Society score, the Tegner activity score, and the Lysholm score. 11 patients underwent femoral supracondylar external torsional osteotomy [(11° (5-20)], 19 a tibial osteotomy with internal torsional correction [(9.3° (5-15)] and 2, a bifocal osteotomy. The Tegner activity score increased from 3.6 before surgery to 4.4 post-surgery. The Lysholm score was improved from 56.7 to 83.7, and the Japanese Knee Society score from 65.7 to 86.8 points. VAS was significantly reduced from 7.3 to 2.6, indicating marked pain relief. 12 patients with patellar dislocation experienced no recurrence of dislocation. 88% (28 joints) of the patients were willing to undergo the procedure again.
Conclusion: We introduce a torsional index for validation and quantification of torsional deformities, and can clearly show that torsional osteotomy is the treatment of choice for a torsional deformity.