2015 ISAKOS Biennial Congress ePoster #1723

Second-Look Arthroscopic Assessment of Articular Cartilage Change After Medial Opening-Wedge High Tibial Osteotomy and Operative Complication Rate

Kazumasa Inoue, MD, Toyohama-Cho, Kanonji, Kagawa JAPAN
Masatoshi Morimoto, MD, Kanonji, JAPAN
Keisuke Adachi, MD, Kanonji, Kagawa Pref. JAPAN
Akihiro Nagamachi, MD, Mitoyo, Kagawa JAPAN
Satoshi Endo, MD, Kanonji JAPAN
Mitoyo General hospital, Kanonji, JAPAN

FDA Status Not Applicable

Summary: ICRS grading of the medial femoral condyle and medial tibial plateau has improved after medial opening-wedge HTO in 97% of patients , but ICRS grading of the patellofermoral joint has got worse in 25% of patients after HTO.

Abstract:

Purpose

The aim of this study is to assess articular cartilage regeneration or degeneration after medial opening-wedge high tibial osteotomy (HTO) in medial femorotibial joint and patellofemoral joint, and to record the rate of operative complications

Methods

Sixty-eight knees in 65 consecutive patients who were underwent medial opening-wedge HTO with an internal plate fixator (TomoFix; Synthes, Solothurn, Switzerland) were assessed. Tegner Lysholm score and Oxford 12-item Knee Score were used to evaluate functional results. Radiological parameters consisted of femorotibial angle (aFTA), posterior tibial slope angle, mechanical axis deviation (%MA) and Caton-index for checking patella height. Articular cartilage in medial femorotibial joint and patellofemoral joint was evaluated by arthroscopy before and about 15months after HTO according to ICRS grading system. In all cases operative complications were recorded.

Results

Duration of follow-up was 15.5±3.8 months. Mean aFTA was corrected 182.5±2.8° pre-operatively to 170.0±2.2° post-operatively (P<0.001). Mean %MA was corrected 26.0±8.8% pre-operatively to 64.7±5.8% post –operatively (P<0.001). Mean posterior tibial slope did not change significantly 6.6±3.8° pre-operatively to 6.4±4.0° post-operatively (p=0.21). Mean Caton-index was decreased 0.89±0.14 to 0.76±0.14 post- operatively(P<0.001). Mean Tegner Lysholm score improved 28.0 ±3.4 to 88.3 ±6.8 points (P<0.001).Mean Oxford 12-item Knee Score improved 28.0 ±5.3 to 42.6 ±4.4 points (P<0.001).ICRS grade in medial femorotibial joint improved in 66 of 68cases (97.0%) , 2 cases no change , averaged 3.99±0.6 pre-operatively to 2.2±0.4 post- operatively. ICRS grade in patellofemoral joint got worse in 17 of 68cases (25.0%) , other 51cases no change , averaged 1.06±0.23 pre-operatively to 1.28±0.45 post-operatively, and worst grading was grade 2.Operative complications are lateral tibial cortex fracture 6 cases (8.8%: Takeuchi classification type 1:4cases,Type 2:0case,Type 3:2cases)
, surgical site infection 2cases(3.0%); superficial infection 1cases(post op 3W),deep infection(post op 1year),CRPS 1case (1.5%), revision surgery 0case , and correction loss 0 case. No significant difference of clinical result was seen between the group in which ICRS grade had no change and the group in which ICRS grade got worse.

Conclusions

From the result of this study , opening-wedge HTO leads to significant improvements in radiographic parameters and knee function. Opening-wedge HTO is thought to be a reliable procedure, but the cartilage in patellofemoral joint showed the progress of degeneration (25.0%) after surgery. Medial opening-wedge HTO should be applied cautiously for patients with patellofemoral joint degeneration.