Knee Arthroscopy

Knee arthroscopy is minimally invasive surgery in which a small camera and instruments are passed through incisions about a centimeter long to look inside the knee and treat problems in the joint. It is one of the most common orthopedic operations, and for the right problem, such as a repairable meniscus tear, a torn ACL, a loose piece of cartilage or bone, or certain cartilage injuries, it can restore function with a quick outpatient recovery. Research over the past two decades has also shown clearly where it does not help: for most knees with arthritis or wear-related (degenerative) meniscus tears, arthroscopy gives little or no lasting benefit over physical therapy. This page explains both sides so you can make an informed decision.

What is knee arthroscopy?

During arthroscopy, the knee is filled with sterile fluid and a pencil-sized camera (the arthroscope) is inserted through a small incision at the front of the knee. The image appears on a monitor, and instruments are passed through one or two other small incisions to trim, repair or reconstruct damaged tissue. Because the incisions are small, most patients go home the same day.

Arthroscopy is a technique, not a single operation. What matters most is the problem being treated, and the evidence differs greatly from one problem to the next.

Problems knee arthroscopy can treat

• Meniscus tears in younger, active knees, especially tears that can be stitched back together (meniscus repair), bucket-handle tears that lock the knee, and root tears. Learn more on our meniscus tears page.
• ACL and other ligament reconstruction, which is performed with arthroscopic assistance. See our ACL injury page.
• Cartilage injuries and osteochondritis dissecans, including fixation of loose fragments, microfracture, osteochondral grafting and implant-based repair. See cartilage defects and OCD and CartiHeal Agili-C.
• Loose bodies, pieces of cartilage or bone floating in the joint that can catch or lock the knee
• Plica syndrome that has not improved with therapy. See our plica syndrome page.
• Discoid meniscus causing symptoms. See our discoid meniscus page.
• Inflamed joint lining (synovitis) and, in selected cases, joint infection washout

When arthroscopy usually does not help: arthritis and degenerative meniscus tears

Many adults over about 40 have meniscus tears on MRI that formed gradually as the knee aged, often along with early arthritis. For years these were commonly “cleaned up” arthroscopically. High-quality research has changed that practice:

• In a placebo-controlled trial, arthroscopic lavage or debridement for knee osteoarthritis was no better than a simulated (placebo) procedure.
• A randomized trial found that adding arthroscopic surgery to physical and medical therapy for knee arthritis gave no additional benefit.
• In a sham-controlled trial of degenerative medial meniscus tears without arthritis, partial meniscectomy was no better than sham surgery, and later analyses found no extra benefit for patients with catching or locking symptoms.
• Trials comparing physical therapy with partial meniscectomy for degenerative tears found similar function over 2 to 10 years, with comparable rates of arthritis development. A meta-analysis found only a small, short-lived benefit from surgery that was gone by one to two years.
• A BMJ clinical practice guideline made a strong recommendation against arthroscopy for nearly all patients with degenerative knee disease.

This does not mean surgery is never appropriate. Crossover data show that some patients do not improve with a structured exercise program and later do well after arthroscopy. In the METEOR trial, about 30% of patients assigned to physical therapy had surgery within six months, and delaying surgery to try therapy first did not worsen their outcomes. Dr. Dold’s approach for degenerative tears is to start with a structured rehabilitation program and reserve surgery for patients with persistent symptoms that match a structural problem. For arthritis, see our knee osteoarthritis page and knee osteotomy.

Traumatic meniscus tears in younger patients: save the meniscus

The meniscus is the knee’s shock absorber, and removing it increases the long-term risk of arthritis. European consensus statements on meniscus tears summarize the goal as preserving meniscus tissue whenever possible. A systematic review found that meniscus repair has a higher reoperation rate than partial meniscectomy, but is associated with better long-term function scores and less arthritis on X-ray. Tear types once thought unrepairable, such as horizontal cleavage and radial tears, have reported repair success rates similar to other tear patterns.

Even in young adults, surgery is not automatic. In the DREAM trial of patients aged 18 to 40 with meniscus tears, early surgery was not better than exercise and education with the option of later surgery at 12 months, although early surgery did relieve self-reported mechanical symptoms more. Tears that block motion (a locked knee), large unstable tears and tears occurring with an ACL injury are generally treated surgically.

ACL reconstruction and cartilage procedures

ACL reconstruction is performed arthroscopically. In the KANON trial of young active adults, early reconstruction plus rehabilitation and rehabilitation with optional later reconstruction produced similar patient-reported outcomes at 2 and 11 years, while the delayed strategy reduced the number of reconstructions. Patients who return to cutting and pivoting sports or whose knees give way are generally treated with reconstruction.

For cartilage injuries, options range from microfracture to osteochondral grafts and cell-based or scaffold repair. Randomized trials have reported better results with matrix-applied chondrocyte implantation than microfracture for larger defects, and better results with osteochondral autograft transfer than microfracture in athletes. The right option depends on the size and depth of the defect, your age, alignment and activity goals.

Before surgery

Your evaluation includes a history and exam, standing X-rays to look for arthritis and alignment problems, and usually an MRI. Imaging findings are interpreted alongside your symptoms: a meniscus tear seen on MRI in a knee with arthritis is often not the cause of pain. If surgery is recommended, Dr. Dold will explain what he expects to find and do, and which procedures may be needed depending on what is seen during the arthroscopy.

The procedure and recovery

Arthroscopy is performed as an outpatient procedure, typically under general anesthesia, a spinal or a nerve block. Most procedures take under an hour. Recovery depends on what is done:

• Partial meniscectomy, loose body removal, plica excision: weight-bearing as tolerated, often with crutches for a few days; return to desk work in days and to sport in roughly 4–6 weeks.
• Meniscus repair: a brace and a period of protected weight-bearing and limited bending, often about 4–6 weeks, with return to sport commonly around 4–6 months.
• ACL reconstruction: a structured rehabilitation program, with return to cutting and pivoting sport usually no earlier than about 9 months.
• Cartilage procedures: often several weeks of protected weight-bearing, with recovery depending on the technique.

An international consensus on rehabilitation after meniscus surgery provides structured guidance that surgeons and physical therapists use to plan your program. Compression stockings for a few days after surgery have been shown in a randomized trial to reduce swelling.

Risks

Serious complications after knee arthroscopy are uncommon. Risks include:

• Infection (septic arthritis), which is rare but serious and usually requires another operation and antibiotics. Risk factors reported in a systematic review include steroid injection around the time of surgery, smoking, obesity, diabetes and longer procedures. Preoperative antibiotics have been associated with lower infection rates.
• Blood clots (DVT/PE). Symptomatic clots are uncommon. In the POT-KAST trial, routine low-molecular-weight heparin after knee arthroscopy did not prevent symptomatic clots, so blood thinners are used selectively according to your personal risk factors.
• Stiffness, persistent swelling, numbness near the incisions, and failure of a repair that may need further surgery.

Why see Dr. Dold

Dr. Dold is a fellowship-trained orthopedic sports medicine surgeon who performs knee arthroscopy, meniscus repair, ligament reconstruction and cartilage procedures. Because the evidence shows arthroscopy helps some knee problems and not others, his evaluation focuses on matching your symptoms and imaging to the treatment most likely to help, including non-surgical care when the research supports it.

Frequently asked questions

Research cited on this page

1. Moseley JB, O’Malley K, Petersen NJ, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med. 2002;347(2):81-8. PubMed
   Placebo-controlled trial: arthroscopic lavage or debridement for knee osteoarthritis was no better than a placebo procedure.
2. Kirkley A, Birmingham TB, Litchfield RB, et al. A randomized trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med. 2008;359(11):1097-107. PubMed
   Randomized trial: arthroscopic surgery for knee osteoarthritis added no benefit to optimized physical and medical therapy.
3. Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear. N Engl J Med. 2013;369(26):2515-24. PubMed
   Sham-controlled trial: partial meniscectomy for a degenerative medial meniscus tear without arthritis was no better than sham surgery at 12 months.
4. Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic partial meniscectomy versus placebo surgery for a degenerative meniscus tear: a 2-year follow-up of the randomised controlled trial. Ann Rheum Dis. 2018;77(2):188-195. PubMed
   Secondary analysis: no evidence that patients with mechanical symptoms, particular tear types or failed conservative care benefited more from partial meniscectomy than placebo surgery.
5. Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic partial meniscectomy for a degenerative meniscus tear: a 5 year follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trial. Br J Sports Med. 2020;54(22):1332-1339. PubMed
   Five-year follow-up: partial meniscectomy gave no benefit over placebo surgery and was associated with a slightly higher risk of radiographic arthritis.
6. Katz JN, Brophy RH, Chaisson CE, et al. Surgery versus physical therapy for a meniscal tear and osteoarthritis. N Engl J Med. 2013;368(18):1675-84. PubMed
   METEOR trial: surgery and physical therapy gave similar function at 6 months; 30% of the therapy group crossed over to surgery.
7. Kise NJ, Risberg MA, Stensrud S, et al. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients: randomised controlled trial with two year follow-up. BMJ. 2016;354:i3740. PubMed
   Randomized trial in middle-aged patients: supervised exercise therapy gave outcomes similar to partial meniscectomy at 2 years.
8. Stensrud S, Risberg MA, Roos EM. Effect of exercise therapy compared with arthroscopic surgery on knee muscle strength and functional performance in middle-aged patients with degenerative meniscus tears: a 3-mo follow-up of a randomized controlled trial. Am J Phys Med Rehabil. 2015;94(6):460-73. PubMed
   Randomized trial: 12 weeks of supervised exercise improved quadriceps strength more than partial meniscectomy.
9. van de Graaf VA, Noorduyn JCA, Willigenburg NW, et al. Effect of Early Surgery vs Physical Therapy on Knee Function Among Patients With Nonobstructive Meniscal Tears: The ESCAPE Randomized Clinical Trial. JAMA. 2018;320(13):1328-1337. PubMed
   ESCAPE trial: physical therapy was non-inferior to partial meniscectomy for non-obstructive meniscus tears over 24 months.
10. Noorduyn JCA, van de Graaf VA, Willigenburg NW, et al. Effect of Physical Therapy vs Arthroscopic Partial Meniscectomy in People With Degenerative Meniscal Tears: Five-Year Follow-up of the ESCAPE Randomized Clinical Trial. JAMA Netw Open. 2022;5(7):e2220394. PubMed
    Five-year ESCAPE follow-up: physical therapy remained non-inferior to partial meniscectomy for degenerative tears.
11. Berg B, Roos EM, Englund M, et al. Arthroscopic partial meniscectomy versus exercise therapy for degenerative meniscal tears: 10-year follow-up of the OMEX randomised controlled trial. Br J Sports Med. 2025;59(2):91-98. PubMed
    Ten-year follow-up: no difference in arthritis progression or development between partial meniscectomy and exercise therapy; both improved.
12. Thorlund JB, Juhl CB, Roos EM, et al. Arthroscopic surgery for degenerative knee: systematic review and meta-analysis of benefits and harms. BMJ. 2015;350:h2747. PubMed
    Meta-analysis: benefit of arthroscopy for the degenerative knee is small, limited in time and absent at one to two years; arthroscopy is associated with harms.
13. Brignardello-Petersen R, Guyatt GH, Buchbinder R, et al. Knee arthroscopy versus conservative management in patients with degenerative knee disease: a systematic review. BMJ Open. 2017;7(5):e016114. PubMed
    Systematic review: knee arthroscopy gave very small or no improvement in pain and function at up to 2 years compared with conservative care; serious complications were very uncommon.
14. Siemieniuk RAC, Harris IA, Agoritsas T, et al. Arthroscopic surgery for degenerative knee arthritis and meniscal tears: a clinical practice guideline. BMJ. 2017;357:j1982. PubMed
    BMJ clinical practice guideline: strong recommendation against arthroscopic surgery for nearly all patients with degenerative knee disease.
15. van de Graaf VA, Wolterbeek N, Mutsaerts EL, et al. Arthroscopic Partial Meniscectomy or Conservative Treatment for Nonobstructive Meniscal Tears: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Arthroscopy. 2016;32(9):1855-1865.e4. PubMed
    Meta-analysis: small benefit of partial meniscectomy for pain and function up to 6 months, no difference at 12 and 24 months.
16. Lee SH, Lee OS, Kim ST, et al. Revisiting Arthroscopic Partial Meniscectomy for Degenerative Tears in Knees With Mild or No Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Clin J Sport Med. 2020;30(3):195-202. PubMed
    Meta-analysis: partial meniscectomy did not improve function or pain compared with conservative care or sham surgery in knees with mild or no arthritis.
17. Herrlin SV, Wange PO, Lapidus G, et al. Is arthroscopic surgery beneficial in treating non-traumatic, degenerative medial meniscal tears? A five year follow-up. Knee Surg Sports Traumatol Arthrosc. 2013;21(2):358-64. PubMed
    Randomized trial: exercise was recommended as initial treatment; one-third of the exercise group with persistent symptoms improved after later arthroscopy.
18. Gauffin H, Tagesson S, Meunier A, et al. Knee arthroscopic surgery is beneficial to middle-aged patients with meniscal symptoms: a prospective, randomised, single-blinded study. Osteoarthritis Cartilage. 2014;22(11):1808-16. PubMed
    Randomized trial: middle-aged patients with meniscal symptoms gained additional benefit from arthroscopy added to structured exercise.
19. Rotini M, Papalia G, Setaro N, et al. Arthroscopic surgery or exercise therapy for degenerative meniscal lesions: a systematic review of systematic reviews. Musculoskelet Surg. 2023;107(2):127-141. PubMed
    Umbrella review: most reviews favor exercise first, while identifying subgroups who fail conservative care and improve with surgery.
20. Petersen W, Achtnich A, Lattermann C, et al. The Treatment of Non-Traumatic Meniscus Lesions. Dtsch Arztebl Int. 2015;112(42):705-13. PubMed
    Systematic review: non-surgical treatment fails for some patients with non-traumatic meniscus tears, who may benefit from partial meniscectomy.
21. Skou ST, Hölmich P, Lind M, et al. Early Surgery or Exercise and Education for Meniscal Tears in Young Adults. NEJM Evid. 2022;1(2):EVIDoa2100038. PubMed
    DREAM trial (ages 18–40): early meniscal surgery was not better than exercise and education with optional later surgery at 12 months; one in four in the exercise group eventually had surgery.
22. Damsted C, Thorlund JB, Hölmich P, et al. Effect of exercise therapy versus surgery on mechanical symptoms in young patients with a meniscal tear: a secondary analysis of the DREAM trial. Br J Sports Med. 2023;57(9):521-527. PubMed
    DREAM secondary analysis: early surgery relieved self-reported mechanical symptoms more than exercise, without better pain or function.
23. Clausen SH, Skou ST, Boesen MP, et al. Two-year MRI-defined structural damage and patient-reported outcomes following surgery or exercise for meniscal tears in young adults. Br J Sports Med. 2023;57(24):1566-1572. PubMed
    DREAM MRI follow-up: similar structural knee changes at 2 years with early surgery or exercise with optional delayed surgery.
24. Kopf S, Beaufils P, Hirschmann MT, et al. Management of traumatic meniscus tears: the 2019 ESSKA meniscus consensus. Knee Surg Sports Traumatol Arthrosc. 2020;28(4):1177-1194. PubMed
    ESSKA consensus on traumatic meniscus tears: long-term outcomes are worse after partial meniscectomy than after meniscus preservation; many tears once considered irreparable should be repaired.
25. Beaufils P, Pujol N. Management of traumatic meniscal tear and degenerative meniscal lesions. Save the meniscus. Orthop Traumatol Surg Res. 2017;103(8S):S237-S244. PubMed
    Review of ESSKA recommendations: “save the meniscus”; horizontal tears in young athletes call for repair rather than meniscectomy.
26. Paxton ES, Stock MV, Brophy RH. Meniscal repair versus partial meniscectomy: a systematic review comparing reoperation rates and clinical outcomes. Arthroscopy. 2011;27(9):1275-88. PubMed
    Systematic review: meniscus repair had a higher reoperation rate than partial meniscectomy but better long-term function scores and less radiographic degeneration.
27. Magnussen RA, Mansour AA, Carey JL, et al. Meniscus status at anterior cruciate ligament reconstruction associated with radiographic signs of osteoarthritis at 5- to 10-year follow-up: a systematic review. J Knee Surg. 2009;22(4):347-57. PubMed
    Systematic review: complete meniscectomy at the time of ACL reconstruction was followed by radiographic arthritis in virtually all patients.
28. Kurzweil PR, Lynch NM, Coleman S, et al. Repair of horizontal meniscus tears: a systematic review. Arthroscopy. 2014;30(11):1513-9. PubMed
    Systematic review: repaired horizontal cleavage tears had a 77.8% success rate, similar to other repaired tear types.
29. Moulton SG, Bhatia S, Civitarese DM, et al. Surgical Techniques and Outcomes of Repairing Meniscal Radial Tears: A Systematic Review. Arthroscopy. 2016;32(9):1919-25. PubMed
    Systematic review: repair of radial meniscus tears improved short-term outcomes; long-term results remain unknown.
30. Fillingham YA, Riboh JC, Erickson BJ, et al. Inside-Out Versus All-Inside Repair of Isolated Meniscal Tears: An Updated Systematic Review. Am J Sports Med. 2017;45(1):234-242. PubMed
    Systematic review: no differences in failure, function or complications between all-inside and inside-out meniscus repair.
31. Frobell RB, Roos EM, Roos HP, et al. A randomized trial of treatment for acute anterior cruciate ligament tears. N Engl J Med. 2010;363(4):331-42. PubMed
    KANON trial: early ACL reconstruction and rehabilitation with optional delayed reconstruction gave similar 2-year outcomes; the delayed strategy reduced reconstructions.
32. Lohmander LS, Roemer FW, Frobell RB, et al. Treatment for Acute Anterior Cruciate Ligament Tear in Young Active Adults. NEJM Evid. 2023;2(8):EVIDoa2200287. PubMed
    KANON 11-year follow-up: no differences in patient-reported outcomes between early reconstruction and initial rehabilitation with optional later reconstruction.
33. Saris D, Price A, Widuchowski W, et al. Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Two-Year Follow-up of a Prospective Randomized Trial. Am J Sports Med. 2014;42(6):1384-94. PubMed
    Randomized trial: matrix-applied chondrocyte implantation (MACI) gave better clinical results than microfracture for knee cartilage defects, with similar safety.
34. Brittberg M, Recker D, Ilgenfritz J, et al. Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Five-Year Follow-up of a Prospective Randomized Trial. Am J Sports Med. 2018;46(6):1343-1351. PubMed
    Five-year follow-up: MACI remained significantly better than microfracture for defects 3 cm² or larger.
35. Gudas R, Stankevicius E, Monastyreckiene E, et al. Osteochondral autologous transplantation versus microfracture for the treatment of articular cartilage defects in the knee joint in athletes. Knee Surg Sports Traumatol Arthrosc. 2006;14(9):834-42. PubMed
    Randomized trial in athletes: osteochondral autograft transfer gave better results than microfracture for knee cartilage defects.
36. Chahal J, Gross AE, Gross C, et al. Outcomes of osteochondral allograft transplantation in the knee. Arthroscopy. 2013;29(3):575-88. PubMed
    Systematic review: osteochondral allograft transplantation outcomes are more favorable in younger patients with single lesions and short symptom duration.
37. van Adrichem RA, Nemeth B, Algra A, et al. Thromboprophylaxis after Knee Arthroscopy and Lower-Leg Casting. N Engl J Med. 2017;376(6):515-525. PubMed
    POT-KAST trial: routine low-molecular-weight heparin after knee arthroscopy did not prevent symptomatic venous thromboembolism.
38. Perrotta C, Chahla J, Badariotti G, et al. Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy. Cochrane Database Syst Rev. 2020;5(5):CD005259. PubMed
    Cochrane review: pulmonary embolism was rare after knee arthroscopy (7 of 3,818 patients); routine prophylaxis evidence in low-risk patients is limited.
39. Balato G, Di Donato SL, Ascione T, et al. Knee Septic Arthritis after Arthroscopy: Incidence, Risk Factors, Functional Outcome, and Infection Eradication Rate. Joints. 2017;5(2):107-113. PubMed
    Systematic review: septic arthritis after arthroscopy causes significant morbidity; risk factors include peri-operative steroids, smoking, obesity, diabetes and longer surgery.
40. Carney J, Heckmann N, Mayer EN, et al. Should antibiotics be administered before arthroscopic knee surgery? A systematic review of the literature. World J Orthop. 2018;9(11):262-270. PubMed
    Study: prophylactic antibiotics were effective in preventing septic arthritis after simple knee arthroscopy; graft soaking reduced infection in graft procedures.
41. Kirkley A, Rampersaud R, Griffin S, et al. Tourniquet versus no tourniquet use in routine knee arthroscopy: a prospective, double-blind, randomized clinical trial. Arthroscopy. 2000;16(2):121-6. PubMed
    Randomized trial: tourniquet use did not affect quality of life or function after routine knee arthroscopy.
42. Tischer TS, Oye S, Lenz R, et al. Impact of compression stockings on leg swelling after arthroscopy – a prospective randomised pilot study. BMC Musculoskelet Disord. 2019;20(1):161. PubMed
    Randomized trial: compression stockings in the early post-operative period reduced swelling after knee arthroscopy.
43. Prill R, Ma CB, Wong SE, et al. The formal EU-US Meniscus Rehabilitation 2024 Consensus: An ESSKA-AOSSM-AASPT initiative. Part II-Prevention, non-operative treatment and return to sport. Knee Surg Sports Traumatol Arthrosc. 2025;33(8):3014-3024. PubMed
    EU-US formal consensus on rehabilitation after meniscus surgery, including partial meniscectomy, repair and return-to-sport criteria.

Medically reviewed by Andrew P. Dold, MD, FAOA, FAAOS, FACS, FRCSC. Last reviewed October 2026. This page is general information, not medical advice. Your own diagnosis and treatment plan depend on your exam and imaging.