Summary

High tibial osteomy showed satisfactory results in patients having constitutional varus with moderate or severe medial cartilage lesion. Cartilage regeneration was achieved more satisfactory with concomitant cartilage repair procedures.

Abstract

Purpose

Generally constitution varus knee deformity is not considered as a good candidate of HTO surgery. However if symptomatic medial cartilage lesion exist in constitutional varus aligned knee, HTO can be one of treatment options. The purpose of this study was evaluate the clinical, arthroscopical and radiological results of HTO performed in patients having constitutional varus with medial cartilage lesion.

Materials and Method

Constitutional varus was defined if preoperative varus deformity was less than 4.5° and non-symptomatic contralateral knee had similar varus deformity (less than ±1° of difference). All patients had symptomatic medial femoral cartilage lesion (more than ICRS grade 3) in initial arthroscopic examination. 40 patients who underwent a second-look arthroscopic evaluation at the time of surgery of plate removal and followed up minimal 2 year were enrolled for this study. Cartilage status of initial arthroscopy and second arthroscopy were evaluated using the International Cartilage repair society (ICRS) grading system. Cartilage repair procedures (microfracture or osteochondral autograft) were performed in 27 patients and isolated HTO without any cartilage repair was performed in 13 patients. Cartilage regeneration was compared depending on concomitant cartilage repair procedure with HTO surgery. KS score and mechanical hip-knee ankle axis and leg length discrepancy at final follow up were assessed for clinical and radiological outcomes.

Results

Except mild squatting difficulty, clinical results were satisfactory (mean KS score was 94.7). The mean alignment changed from varus 3.08° to valgus 2.85°. The contralateral knee had mean 2.89° of varus alignment. Leg length discrepancy was not significant (P> 0.05). Leg length increased in open HTO group (4 mm ) and decreased in closed HTO group (3 mm: P<.05).
Mean ICRS grade of medial femoral condyle was improved from 3.38 to 2.26. In cartilage repair group, cartilage regeneration was more satisfactory at second look arthroscopic evaluation ( P<0.05, Mean ICRS grade 2.09 in cartilage repair group vs 2.62 in isolated HTO group).

Conclusion

High tibial osteomy showed satisfactory results in patients having constitutional varus with moderate or severe medial cartilage lesion. Cartilage regeneration was achieved more satisfactory with concomitant cartilage repair procedures.