High tibial osteotomy (HTO) is widely accepted as a treatment option in patients with medial unicompartimental osteoarthritis (OA) and varus morphotype of the knee. We increasingly see younger patients with a chronic anterior instability, an additional varus morphotype and beginning medial OA. Treatment options for these patients are not clear up to now. In this clinical study we compare for the first time three different treatment rationales and introduce a concept of symptom-oriented surgery in young patients with medial OA and chronic anterior instability.
Materials/methods: Between 1984 and 1994 30 patients were treated with a medical unicompartimental OA and chronic anterior instability of the knee. Patients were grouped into three different groups according to treatment. 1) only HTO was performed. 2) HTO and simultaneously an ACL-reconstruction and 3) HTO and 6-12 months later an ACL-reconstruction was performed. 27/30 patients were available for follow-up. All patients had an arthroscopy before surgery. Evaluation was done according to the IKDC-protocol and X-ray documentation.
Results: Pain was a major problem in all patients. None of them was completely pain-free. 8/27 patients had pain even with light activities. This included 1/11 patients of group 1, 3/8 of group 2 and 4/8 of group 3. 9/27 patients had stable knee joints with a Lachman-test of 3-5 mm. No patient had a Lachman test < 3 mm. 3/11 patients of group 1, 3/8 of group 2 and 2/8 of group 3 had a Lachman test of 5-10 mm. A positive pivot-shift could be found in 9/27 patients. 2/11 of group 1, 4/8 in group 2 and 3/8 in group 3. The overall IKDC-score improved in 23/27 patients, one patient remained unchanged, two deteriorated. Radiologically a slight progression of OA could be seen in all patients. Radiological signs of OA and pain did not show any correlation. There was, however, a significant rate of postoperative complications involving 4/11 patients of group 1 and 3/8 of group 3. There were 6 major complications in 5/8 patients in group 2. Nevertheless overall patient satisfaction was high. 25/27 patients would undergo the procedure again.
Conclusion: HTO is a good treatment option for younger patients with medial OA and chronic anterior instability of the knee. These patients pose a high challenge to diagnostic and operative skills of the surgeon. Main symptoms of these patients have to be analysed clearly in terms of instability and pain. In patients aged 40 and older an HTO alone is an excellent treatment option with reproducibly good results. In younger patients we advise an HTO first. If instability persists, an ACL-reconstruction can be done 6-12 months later. One has to be aware that a simultaneous combined procedure has a significant complication rate. Hence if a simultaneous combined treatment is planned the surroundings including surgical technique, rehabilitation and patient compliance have to be ideal. These young patients need an activity counselling in order to realise that their knee joint has suffered significantly from the injury and ongoing high physical demands on their knee joint.