Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effect of Arthroscopic Partial Resection of Degenerative Meniscus Tear on Development of Knee Osteoarthritis: Which is the Chicken and the Egg?
Brief Summary: It has been previously demonstrated that the risk for the development of knee osteoarthritis is increased after both meniscus tear and meniscectomy. However, it is still unclear whether this is due to the meniscus tear per se, the surgery, or whether the development of knee osteoarthritis is completely independent of the two. Accordingly, the aim of the study is to investigate the effect of arthroscopic partial meniscectomy on the development of knee osteoarthritis 2 to 10 years after the procedure.


Options:
A: Inclusion Criteria:

* Patients between 45 and 70 years of age at presentation.
* A meniscal tear visualized on MRI. The meniscal tear can either be isolated or combined with a partial asymptomatic Anterior Cruciate Ligament (ACL) injury or an asymptomatic degenerative ACL shown on MRI with no abnormal clinical findings (a negative Lachman test and Pivot Shift).
* Mental Competence.
* Willingness to comply with follow up schedule.
* Written informed consent.

Exclusion Criteria:

* Knee locking or trauma leading to acute surgery.
* One of the following associated injuries on the index knee:

  1. A symptomatic partial ACL rupture or any total ACL rupture determined by clinical examination (positive Lachman test and/or positive Pivot Shift) and shown on MRI;
  2. A complete Posterior Cruciate Ligament (PCL) injury;
  3. Cartilage change down to bone; grade 4 of the Kellgren Lawrence Grading Scale for Osteoarthritis visualized on X-ray;
  4. An injury to the lateral/posterolateral ligament complex with significantly increased laxity.
* A history of knee surgery other than diagnostic arthroscopy on the index knee.
* Tumors on MRI suspected for a malignancy.
* Obese patients with Body Mass Index (BMI) \> 35.
* ASA 4-5 patients which can severely interfere with rehabilitation.
* General disease that effects physical function or systemic medication/abuse of steroids (e.g., rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus, gout, pseudogout)
* Any other medical condition or treatment interfering with the completion or assessment of the trial, e.g. contraindications to MRI or surgery.
* Drugs or alcohol abuse.
* Patients unable to speak or read Dutch.
B: Inclusion Criteria:

1. Age: 35 to 65 years of age.
2. A pain located on the medial joint line of the knee that has persistent at least for 3 months.
3. Pain that can be provoked by palpation or compression of the joint line or a positive McMurray sign.
4. Tear of the medial meniscus on MRI.
5. Degenerative rupture of the medial meniscus confirmed at arthroscopy.

Exclusion Criteria:

1. Acute, trauma-induced onset of symptoms.
2. Locking or painful snapping of the knee joint.
3. A surgical operation performed on the affected knee.
4. Osteoarthritis of the medial compartment of the knee (determined by clinical criteria of the ACR).
5. Osteoarthritis on knee radiographs (Kellgren-Lawrence \> 1).
6. Acute (within the previous year) fractures of the knee.
7. Decreased range of motion of the knee.
8. Instability of the knee.
9. MRI assessment showing a tumor or any other complaint requiring surgical or other means of treatment.
10. Arthroscopic assessment showing anything other than a degenerative tear of the medial meniscus requiring surgical intervention.
C: Inclusion Criteria:

* Adults aged 18 to 40 years with knee pain
* Clinical history and symptoms consistent with meniscal tear and meniscal tear verified on magnetic resonance imaging (MRI)
* Deemed eligible for meniscal surgery (i.e. repair or resection) by the examining orthopedic surgeon
* Willing to participate in 12 weeks of supervised exercise twice a week or undergo surgery for the meniscal tear as soon as possible

Exclusion Criteria:

* Previous knee surgery on the affected knee
* Clinical suspicion (acute locking of knee AND/OR extension deficit) of displaced bucket-handle tear confirmed by MRI
* Fracture of the affected extremity within the previous 12 months
* Complete rupture of one or more knee ligaments.
* Participation in supervised systematic exercise for knee problems within the last 3 months prior to recruitment
* Other reasons for exclusion (Unable to understand Danish, mentally unable to participate, etc.)
D: Inclusion Criteria:

1. Idiopathic or secondary osteoarthritis of the knee as diagnosed by Altman et al 2 classification tree -83 percent sensitivity, 93percent specificity
2. Grades 2 to 4 severity of OA by radiographic evaluation- modified Kellgren and Lawrence grading system
3. Age greater than 18.

Exclusion Criteria:

1. Inflammatory or post-infection arthritis of the knee
2. Previous arthroscopy for treatment of knee OA
3. Isolated medial compartment OA Grade 3-4 with greater than 5 degrees mechanical varus -ideal candidate for high tibial osteotomy
4. Isolated lateral compartment OA Grade III-IV with greater than 5 degrees mechanical valgus -ideal candidate for high tibial osteotomy or distal femoral osteotomy
5. Grade 4 OA in at least 2 compartments and over 60 years of age -ideal candidate for total knee arthroplasty
6. Cortico-steroid injection within the last three months.
7. Major neurological deficit
8. Major medical illness -life expectancy less than 2 years or with unacceptably high operative risk.
9. Pregnant
10. Unable to speak or read English
11. Psychiatric illness that limits informed consent
12. Unwilling to be followed for 2 years

Answer: B