2015 ISAKOS Biennial Congress ePoster #1704

Does Patellofemoral Osteoarthritis Influence on Functional Outcomes After Opening Wedge HTO?

Jong-Keun Seon, MD, PhD, Hwasun, Jeonnam KOREA, REPUBLIC OF
Eun-Kyoo Song, MD, PhD, Prof., Gwangju KOREA, REPUBLIC OF
Seung-Hun Lee, MD, Sun-Cheon KOREA, REPUBLIC OF

Chonnam National Uinversity Hwasun Hospital, Hwasun, KOREA

FDA Status Cleared

Summary: The opening wedge HTO can provide good clinical outcomes in patient combined medial compartment OA with PF joint OA.

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Abstract:

Background

The high tibial osteotomy (HTO) has been one of the gold standard treatments for medial unicompartmental osteoarthritis (OA) of the knee in middle aged patients. However, medial unicompartmetnal OA is often accompanied by patellofemoral OA. Moreover, the patellofemoral contact pressure can be increased after HTO, especially after opening wedge HTO. Therefore, the opening wedge HTO has been considered as relative contraindication for patients with medial unicompartmental OA associated with patellofemoral OA. There is controversy on whether OA of the patellofemoral joint influence the clinical outcomes after high tibial osteotomy in the clinical study. The aim of this study is to evaluate the effect of patellofemoral OA on the clinical and radiological outcomes after opening wedge HTO in patients with medial unicompartmental OA. Also we evaluate whether the anterior knee pain is aggravated after opening wedge HTO in medial compartmental OA patients who had concurrent OA of the PF joint at the time of surgery.

Methods

A total 81 patients who underwent opening wedge HTO for medial compartmental OA were included for this study. Among them, 40 patients (OA group) had ICRS grade IV OA in the patellofemoral joint at the time of surgery. And rest of them (n=41, non-OA group) did not have more than grade II OA in the patellofemoral joint. After minimum of 2 year follow-up, we evaluated and compared the anterior knee pain using visual analogue scale (VAS), Knee Society Score (KSS), and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score between two groups. The radiologic outcomes were also compared in terms of congruence angle and progression of OA on the PF joint. In PF OA group, we evaluated the anterior knee pain using visual analogue scale (VAS) during stair climbing or rising from the chair compared with those before surgery.

Results

After the surgery, KSS and WOMAC scores were significantly improved in both groups without statistical intergroup difference. The KSS scores were 121.46 and 125 points, and WOMAC scores were 14.1 and 13.9 points in groups with or without OA of the PF joint, respectively. In terms of anterior knee pain, the number of patients with more than 3 in VAS scale was more in PF OA group (17%, 7/41) than in PF non-OA group (7.5%, 3/40) at the final follow-up (p=0.04). However, the mean value of anterior knee pain was similar in both groups (2.5 in OA vs. 1.7 in non-OA group, p=0.72). In terms of radiologic outcomes, there was no change in congruence angle after surgery in both groups. 4 patients in OA group and 2 patients in non-OA groups showed progression of OA compared with preoperative condition on the Merchant view. In the OA group, although average anterior knee pain were not significantly aggravated after surgery, 6 out of 41 patients complained worse anterior knee pain compared with the preoperative values during stair climbing or rising from the chair.

Conclusion

Overall opening wedge high tibial osteotomy can provide good clinical outcomes in patient combined medial compartment OA including anterior knee pain regardless of the presence of OA in the PF joint. However, the surgeon should be cautious when they are doing HTO in patient with medial and patellofemoral OA because anterior knee pain developed or patellofemoral OA progression was found after surgery in some patients.