Please select the eligibility criteria that correspond to the clinical trial below.
Title: Focal Cartilage Defects in the Knee - A Randomized Controlled Trial Comparing Arthroscopic Microfracture With Arthroscopic Debridement
Brief Summary: 114 patients between 18 and 50 years with an isolated focal cartilage defect in the knee will be randomized to either receive arthroscopic microfracture or arthroscopic debridement. Both groups will then undergo a systematic physiotherapy training regime for 6-9 months. The groups will then be compared for results, after 3, 6, 12 and 24 months, by using validated patient reported outcome scores (Lysholm, KOOS, Tegner) and EQ5D as well as clinical examination and radiological findings at 2 years (MRI).


Options:
A: inclusion Criteria:

* degenerative knee pain
* age: \> 18 years
* informed consent
* none to moderate comorbidity
* arthroscopy under general anaesthesia indicated

exclusion Criteria:

* trauma of the knee within the last 6 weeks before surgery
* circumscribed cartilage lesion with possibility of repair microfracture or autologous chondrocyte transplantation - procedures
* contraindications against PRP. application
* malignancies
* severe comorbidities
* age \<18 years
* physically or mentally not able to provide informed consent
* severe knee instability
* corticosteroid injections within the last 6 weeks before surgery
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:

* Single symptomatic lesion of the trochlea, medial or lateral femoral condyle of the knee less than 2 cm2
* Cartilage lesion ICRS grade 3 or 4
* More than 50 % of the menisci intact
* Ligamentous stable knee
* Lysholm Score \< 75
* Acceptable range of motion (5-105 degrees)

Exclusion Criteria:

* Osteoarthritis
* Malalignment \> 5 degrees measured clinically, and if uncertainty on HKA radiographs
* Systemic arthritis
* Previous cartilage surgery except OCD fixation
* Obesity BMI \> 30
* Serious drig or alcohol abuse
* Inability to answer questionnaires or partake in rehabilitation
* Comorbidity that may influence surgery or rehabilitation
* Pregnancy
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: C