Treatment of Medial Compartmental Osteoarthritis Grade 1-4 With TomoFix™ Small or Conservatively

Study Overview
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Brief Summary
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The primary objective of this prospective multicenter study is to assess whether the functional outcome measured with the Knee Injury and Osteoarthritis Outcome Score (KOOS) for patients with medial unicompartmental osteoarthritis and osteonecrosis of the knee treated with open wedge high tibial osteotomy (HTO) using the TomoFix™ Small is better than the functional outcome after conservative treatment.

Detailed Description
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Osteoarthritis (OA) of the knee (gonarthrosis) is a common medical condition and causes pain and disability. By 65 years of age, the majority of the US population has radiographic evidence of OA and 11% have symptomatic OA of the knee. In Japan, OA of the knee is more common due to the common sitting style with maximally flexed knees and parallel position of both legs. High Tibial Osteotomy (HTO) for knee OA is a standard procedure in orthopedic surgery. Six years ago, HTO using TomoFix™ was introduced. Because Asian people have different geometric dimensions of the tibiae, an adaptation of size and shape was necessary, and the new TomoFix™ Small was developed. Although there is widespread literature concerning osteotomy for treating knee OA, literature assessing patient outcome after open wedge HTO using TomoFix™ is rare and for TomoFix™ Small, this data is still nonexistent. Therefore, the primary aim of the present multicenter study is to evaluate patient functional outcome using the KOOS. Since a proportion of patients with the indication for HTO refuse surgery and opt to receive conservative treatment, the functional results of patients treated with HTO using TomoFix™ Small will be compared with these patients.

Official Title
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Treatment of Medial Compartmental Osteoarthritis Grade 1-4 (Kellgren-Lawrence) or Osteonecrosis With TomoFix™ Small or Conservatively

Conditions
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Osteoarthritis, Knee, Osteonecrosis

Intervention / Treatment
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* Other: No intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 40 years of age and older Patients with OA Grade 1-4 (Kellgren-Lawrence) or osteonecrosis (ON) Stage 2-4 (according to the Koshino classification) Indication for open wedge HTO with the TomoFix™ Small No ligamental laxity Signed written informed consent (by the subjects or legal guardian) and agreement to attend all planned follow-ups Willing and able to comply with the postoperative management program Able to understand and read country national language at an elementary level Exclusion Criteria: Femoro-tibial angle (FTA) > 185o (standing view x-ray) Flexion contracture > 15o Total knee replacement or unicompartmental knee on the contralateral side Infections located between the middle of the femur and the ankle Systemic bacterial infections Severe osteoarthritis or surgery of the hip joint Smoking of more than 20 cigarettes per day Immunodeficiency or compromised host Patients who have participated in any other device or drug related clinical trial within the previous month ACL/PCL reconstruction of the same knee Severe osteoarthritis of the ipsilateral ankle joint For conservative group only: HTO on the contralateral side Major surgery on both knees (minor surgery as arthroscopic meniscectomy and synovectomy is allowed)

Ages Eligible for Study
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Minimum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Tomofix_small<br>Surgical treatment using TomoFix TM Small | Other: No intervention<br> <br> |
| Conservative treatment<br>In the control group, patients who refused to have surgery will be allowed to be treated using different options of conservative treatment. The frequency of applications depends on the hospital and will therefore be documented in the study. An arthroscopy is not obligatory under this treatment group, but is permitted. The following conservative treatment methods are allowed: Physical therapy Specific exercises for the muscles Injections into the knee joint Brace Medication No therapy | Other: No intervention<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee Injury and Osteoarthritis Outcome Score (KOOS) |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient-evaluated function of the knee and quality of life, a. assessed with the Oxford-12-item knee score b. assessed with the WOMAC (as calculated from the KOOS) |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 
| Clinician-evaluated function of the knee, assessed with the Japanese Orthopaedic Association (JOA) score |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 
| Health-related quality of life assessed by the generic Short Form-36 (SF-36) instrument |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 
| Range of motion (ROM) |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 
| Local and general pain, assessed with the Visual Analogue Scale (VAS) |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 
| Possibility and duration of the Japanese sitting style |  | 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 
| Surgery details, Postoperative treatment, Postoperative rehabilitation, Utilization |  | postoperative period | 
| Evaluation of degenerated and regenerated cartilage (arthroscopic findings assessed according to ICRS and Outerbridge / Koshino) |  | intraoperative and after 2 years | 
| Radiological parameters (e.g. union, delayed union, Kellgren-Lawrence classification, joint space narrowing, tibial slope, tibia vara, patella height according to Blackburne-Peel, modified Insall-Salvati ratio, subluxation of patella) |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 
| Complications and mortality |  | 1 month, 3 months, 6 months, 12 months, 24 months, 3 years, 4 years, and 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Knee osteoarthritis, knee osteonecrosis, osteotomy