Original Article With Video Illustration
Second-Look Arthroscopic Assessment of Cartilage Regeneration After Medial Opening-Wedge High Tibial Osteotomy

https://doi.org/10.1016/j.arthro.2013.10.008Get rights and content

Purpose

The purposes of this study were to evaluate regeneration of the articular cartilage after medial opening-wedge high tibial osteotomy for knees with medial-compartment osteoarthritis and to assess the clinical outcome and cartilage regeneration according to the postoperative limb alignment at 2 years postoperatively.

Methods

The study involved 159 knees in 159 patients. For evaluation of cartilage degeneration, the International Cartilage Repair Society grading system was used for arthroscopic grading on initial arthroscopy during high tibial osteotomy. The patients underwent a second-look arthroscopic evaluation of the articular cartilage at the time of removal of the plate, an average of 2 years after the initial osteotomy. For evaluation of cartilage regeneration, the articular cartilage was classified into 2 stages as no regenerative change (grade 1) or white scattering with fibrocartilage, partial coverage with fibrocartilage, or even coverage with fibrocartilage (grade 2) on second-look arthroscopy. Maturation of the cartilage regeneration was defined as even coverage with fibrocartilage. “Immaturation” of the cartilage regeneration was defined as white scattering with fibrocartilage or partial coverage with fibrocartilage. Clinical evaluations were performed by use of Knee Society scores preoperatively and at 2 years postoperatively. We divided the knees into 3 groups according to the postoperative limb alignment. Group A comprised knees with a mechanical tibiofemoral angle of 0° or less. Group B comprised knees with a mechanical tibiofemoral angle greater than 0° and less than 6°. Group C comprised knees with a mechanical tibiofemoral angle of 6° or greater.

Results

Grade 2 regeneration was achieved in the medial femoral condyle articular cartilage in 92% of knees and in the medial tibial plateau articular cartilage in 69% of knees. Maturation of the cartilage regeneration was found in the medial femoral condyle articular cartilage in 4% of knees and in the medial tibial plateau articular cartilage in 1% of knees. At follow-up, no significant differences were seen between clinical outcomes and initial cartilage degeneration (P = .338) or cartilage regeneration (P = .699). Regeneration of the medial femoral condyle articular cartilage was found in 75% of group A knees, 95% of group B knees, and 92% of group C knees. Significant differences were seen between cartilage regeneration and clinical outcomes (P = .001), as well as postoperative limb alignment (P = .018). Clinical and regeneration results were better in group B than in groups A and C.

Conclusions

The degenerated cartilage of the medial femoral condyle and medial tibial plateau could be partially or entirely covered by newly regenerated cartilage at 2 years after adequate correction of varus deformity by medial opening-wedge high tibial osteotomy without cartilage regeneration strategies.

Level of Evidence

Level IV, therapeutic case series.

Section snippets

Methods

This study was a retrospective, nonrandomized, sequential review. Between January 2009 and January 2010, 182 patients underwent HTO for medial-compartment osteoarthritis of the knee at the Department of Orthopedic Surgery, Murup Hospital, Gyeongnam, South Korea. Inclusion criteria for HTO were as follows: symptomatic medial osteoarthritis or articular cartilage lesions of the knee joint in active patients, varus malalignment (minimum of 10 mm of medialization of the weight-bearing axis from the

Clinical and Radiographic Results

We evaluated 14 knees in 14 men and 145 knees in 145 women, comprising 159 knees in 159 patients. Approximately 24.9 months after surgery (range, 22 to 26 months), the patients underwent second-look arthroscopic examinations. The mean age (± standard deviation) of the patients at the time of second-look arthroscopy was 60.2 ± 6.8 years (range, 41 to 75 years). The mean Knee Society knee score improved significantly from 68.5 ± 11.9 before the operation to 92.5 ± 7.1 at follow-up 2 years

Discussion

The principal findings of this study showed that the degenerative cartilage was partially regenerated in almost all cases and fully regenerated in only some cases after medial opening-wedge HTO, and postoperative limb alignment influenced the clinical outcome and regeneration of the cartilage after medial opening-wedge HTO. This study evaluated regeneration of the articular cartilage after a medial opening-wedge HTO for knees with medial-compartment osteoarthritis and assessed the clinical

Conclusions

The degenerated cartilage of the medial femoral condyle and medial tibial plateau could be partially or entirely covered by newly regenerated cartilage at 2 years after adequate correction of varus deformity by medial opening-wedge HTO without cartilage regeneration strategies.

References (34)

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The authors report that they have no conflicts of interest in the authorship and publication of this article.

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