A Randomized Trial Comparing High Tibial Osteotomy Plus Non-Surgical Treatment and Non-Surgical Treatment Alone

The purpose of this study is to compare patients with knee osteoarthritis (OA) receiving optimized non-surgical treatment plus surgical realignment of the tibia, or optimized non-surgical treatment only. We hypothesize that outcomes assessed at 12 and 24 months follow-up will suggest favourable changes in patients undergoing surgical realignment when compared to patients receiving non-surgical treatment only.

This two groups, parallel design randomized controlled trial will compare patients with medial compartment knee OA and varus alignment receiving optimized non-surgical treatment plus High Tibial Osteotomy (HTO) to similar patients receiving optimized non-surgical treatment only. All participants will receive non-surgical treatment that will be individualized to the patient and include medications, physiotherapy and nutritional seminars. The non-surgical treatment will include supervised physiotherapy and nutritional seminars once per week for 12 weeks, will be accompanied and followed by a home program, and follow-up appointments for potential modification every three months for the duration of the study. Participants randomized to surgery will also undergo medial opening wedge HTO after 12 weeks of optimized non-surgical treatment. Both groups will follow the same schedule of clinic visits throughout the 24 month follow-up period. MRI-derived measures of articular cartilage morphology, biological markers of articular cartilage degradation and synthesis, gait biomechanics and patient-reported outcomes will be assessed at baseline, 12 and 24 months follow-up.

Eligibility Criteria:
Inclusion Criteria:

1. Is the subject either:

   1. 25-55 years old?
   2. Older than 55 but still active (ex. physical labour, regular recreational activities)?
2. Does this subject present with varus alignment? (Based on hip to ankle x-rays).
3. Does this subject have clinical Knee OA? (MAA \<-2° on full limb standing AP) according to the Altman classification primarily involving the medial compartment of the knee?
4. Patient is a good candidate for high tibial osteotomy and will be receiving a PEEK plate, or if receiving an alternate plate, agrees to have the plate removed prior to 1 year postoperative.

Exclusion Criteria:

1. Has this subject had a previous HTO or joint replacement in either limb?
2. Is this subject likely to undergo bilateral HTO within the 2 year follow up period?
3. Does this subject have an unstable knee or ligament?
4. Does this subject have inflammatory or infectious arthritis of the knee?
5. Radiographic disease too advanced for HTO (ie. diffuse lateral compartment, patellofemoral joint OA and/or severe enough disease to suggest that joint replacement is the better surgical option) and/or Kellgren and Lawrence grade 4.
6. The subject's disease is not advanced enough (symptomatically or radiographically) to warrant HTO.
7. Does this subject have a major medical illness with life expectancy \<2 years or with an unacceptably high operative risk?
8. Does this subject have a major neurological deficit that would affect gait?
9. Is this subject possibly pregnant or planning pregnancy?
10. Is this subject unable to read English?
11. Does this subject have a psychiatric illness that limits informed consent?
12. Is the subject unlikely to comply with study protocol?