Overview
Knee arthroscopy combines direct inspection with probing of intraarticular structures. It complements the history, physical examination and imaging; it does not replace them. With accurate clinical assessment and MRI, arthroscopy solely to establish a diagnosis is rarely necessary. A complete diagnostic survey remains the essential first stage of an indicated operative arthroscopy (Campbell, Chapter 56).
The priorities are reproducible positioning, accurately located portals, clear visualization and a systematic examination of every compartment. Poor access should be corrected before instruments are forced into a tight joint (Campbell, Chapters 54 and 56).
Indications and Contraindications
Indications: assessment and treatment of a clinically established intraarticular problem, with a diagnostic survey before the planned intervention. The anticipated procedure and the surgeon's experience determine whether an arthroscopic or open approach is appropriate (Campbell, Chapters 54 and 56).
Complete the noninvasive assessment first: review the history, perform a thorough examination and obtain appropriate radiographs and other indicated imaging. Minor abnormalities likely to respond to conservative treatment are not, by themselves, an indication for arthroscopy (Campbell, Chapter 54).
Infection risk: local skin disease that risks joint contamination, or a remote infection that may seed the operative site, contraindicates elective arthroscopy (Campbell, Chapter 54).
Relative contraindications: marked ankylosis and major collateral ligament or capsular disruption. A disrupted capsule permits fluid to escape into the soft tissues; Campbell describes allowing early capsular healing, usually 1–2 weeks, or repairing the capsule before arthroscopy. In this setting, gravity inflow and maintained outflow help limit excessive fluid pressure (Campbell, Chapter 54).
Equipment and Operating Room Setup
A 4-mm, 30-degree arthroscope is the principal viewing instrument. A 70-degree arthroscope can improve views around corners, but orientation is more demanding and a blind area may exist directly ahead of the lens (Campbell, Chapters 54 and 56).
Have a probe available for examination of cartilage, meniscal stability and cruciate ligament tension. The rounded elbow of the probe is useful for palpation; the sharp tip should not be driven into cartilage (Campbell, Chapter 54).
Prepare irrigation, suction, the light source, camera and instruments before starting. Arrange the equipment to permit compartment opening and unrestricted movement of the operative leg (Campbell, Chapter 56).
Use full operating-room sterility, waterproof gowns and waterproof drapes that isolate the unprepared proximal thigh and foot. Small incisions do not reduce the consequences of an intraarticular infection (Campbell, Chapter 56).
Document the examination with representative photographs or video clips. Systematic image capture supports the operative record and later review (Campbell, Chapter 54).
Anesthesia and Tourniquet
Local, regional or general anesthesia can be used. General anesthesia is often preferred for acute painful injuries, substantial intraarticular surgery or patients unlikely to tolerate an awake procedure (Campbell, Chapters 54 and 56).
A thigh tourniquet may be applied and reserved for bleeding that impairs visualization. Inflation blanches the synovium and can interfere with assessment of synovial disease and meniscal vascularity (Campbell, Chapter 56).
Evaluate meniscal vascularity with the tourniquet deflated and joint pressure reduced. Keep tourniquet time as short as possible; Campbell advises avoiding more than 90 minutes in routine procedures and prolonged inflation beyond 2 hours in complex procedures (Campbell, Chapter 56).
Chapter 54 cautions about the chondrotoxicity of intraarticular local anesthetics and advises against continuous intraarticular pain-pump catheters. Its analgesia discussion should be considered alongside the local-anesthetic techniques described in Chapter 56.
Positioning and Setup
Supine, Table-Flat Position
Position the patient supine and prepare the limb from the ankle to the tourniquet. A padded lateral post or thigh holder provides a counterforce for controlled compartment opening.
With the leg abducted, the surgeon can support the foot and ankle against the hip while applying gentle valgus stress against the post or holder to open the medial compartment.
For the lateral compartment, place the leg in a figure-four position with assistance as needed. Confirm that the drapes and equipment permit this movement.
(Campbell, Chapter 56.)
Leg-Dangling Position
Place the knee just beyond the distal break of the operating table, then lower the foot section so that the knee can flex to approximately 90 degrees.
Pad and support the opposite limb carefully. Hip flexion and a padded bolster can reduce femoral nerve tension and flatten the lumbar spine.
Before preparation and draping, confirm that the holder permits the flexion required for the intended procedure. A rigid holder limits available positions; excessive force against it can injure ligaments or cause a fracture.
(Campbell, Chapters 54 and 56.)
Portal Planning
Mark the patella, patellar tendon, joint lines and posterior contours of the femoral condyles before joint distention. Recheck the landmarks after distention. Portal measurements are starting landmarks; final placement must suit the individual knee and the target pathology (Campbell, Chapter 56).
Portal | Landmarks described by Campbell | Main role and cautions |
|---|---|---|
Anterolateral | Approximately 1 cm above the lateral joint line, 1 cm lateral to the patellar tendon and 1 cm below the patella | Principal viewing portal. A low portal may injure or pass beneath the anterior horn of the lateral meniscus; a high portal limits posterior access. Placement against the tendon may enter the fat pad. |
Anteromedial | Approximately 1 cm above the medial joint line, 1 cm medial to the patellar tendon and 1 cm below the patellar tip | Probing, instrumentation and additional viewing. Confirm the trajectory with a spinal needle under anterolateral arthroscopic vision. |
Posteromedial | Soft interval behind the medial femoral condyle; approximately 1 cm above the posteromedial joint line and 1 cm posterior to the condylar margin | Selected posterior meniscal lesions, loose bodies and PCL procedures. Mark before distention; establish with the knee near 90 degrees and the posteromedial recess distended. |
Superolateral | Just lateral to the quadriceps tendon, approximately 2.5 cm above the superolateral patellar corner | Dynamic assessment of patellofemoral tracking and congruity with a 30- or 70-degree arthroscope. |
(Campbell, Chapter 56, pp. 2334–2335.)
Accessory Portals
Far medial or lateral portals: use a spinal needle to demonstrate access to the target above the meniscus before making the incision. Adjust the needle entry if the planned instrument trajectory is blocked. These portals have less margin for error around the meniscus, collateral ligaments and articular surface.
Posterolateral portal: reserve for a defined need when anterior viewing is inadequate or posterior instrumentation is required. Posterior access carries a risk of cartilage injury and injury to structures in the popliteal space; uncontrolled advancement through the capsule must be avoided.
Central transpatellar tendon portal: Campbell does not recommend routine use because the incision and instrumentation can damage the patellar tendon.
(Campbell, Chapter 56.)
Surgical Technique
Establish Viewing and Working Access
Confirm joint landmarks, establish the planned viewing access and obtain adequate illumination and distention. Maintain a clear irrigation medium.
From the anterolateral viewing portal, introduce a spinal needle at the intended anteromedial site. Check that the trajectory reaches the target without passing through a meniscus.
Create the anteromedial portal under vision, directing the cutting edge away from the meniscus. Use protective sheaths for sharp instruments where appropriate.
Bring the probe into view before advancing toward the target. If access is poor, correct portal trajectory or positioning rather than forcing the instrument against cartilage.
(Campbell, Chapters 54 and 56.)
Triangulation and Fluid Management
Begin with the scope far enough from the target to provide a broad field of view. Advance the scope and instrument together only after orientation is clear.
If triangulation is lost, contact the arthroscope sheath with the accessory instrument and follow it toward the scope tip to bring the instrument back into view.
Use irrigation pressure appropriate to the pump and patient. Chapter 54 describes 40–60 mm Hg for the knee, with variation between pump systems. Monitor soft-tissue swelling and compartment tightness rather than relying on a pressure setting alone.
Keep any motorized cutting tip and its window visible before activation. Excess fluid pressure, capsular disruption and prolonged surgery increase the concern for extravasation.
(Campbell, Chapter 54.)
Systematic Diagnostic Examination
Use the same sequence in every knee. Campbell divides the examination into seven compartments; consistency matters more than the precise order. Inspection should be combined with probing where indicated, rather than relying on appearance alone (Campbell, Chapters 54 and 56).
Suprapatellar pouch and patellofemoral joint: inspect the pouch and patellofemoral surfaces. A superolateral view can supplement assessment of patellar tracking through flexion and extension.
Medial gutter: inspect the medial parapatellar recess before proceeding to the tibiofemoral compartment.
Medial compartment: apply controlled valgus stress to improve access. Inspect cartilage and examine the medial meniscus with the probe, including its undersurface when accessible. A tight knee may conceal the posterior horn.
Intercondylar notch: examine the cruciate ligaments and use the probe to assess tension and continuity where appropriate.
Posteromedial compartment: obtain a view through the notch or use a separate posteromedial portal when necessary. An incomplete anterior view should not be accepted as exclusion of a posterior lesion. In ACL-injured knees, Campbell highlights the need to consider a medial meniscal ramp lesion.
Lateral compartment: use the figure-four position to improve access; inspect cartilage and probe the lateral meniscus. Include the posterior horn and popliteal hiatus in the survey.
Lateral gutter and posterolateral compartment: complete the lateral recess examination. If the posterior compartment cannot be adequately assessed from an anterior portal, consider additional access appropriate to the pathology and the surgeon's experience.
(Campbell, Chapter 56, pp. 2336–2337; Chapter 54, probe examination.)
Pearls and Pitfalls
Mark before distention: swelling changes palpable landmarks and makes accurate posterior portal localization more difficult.
Balance portal height: a high anterior portal avoids some fat-pad interference but may restrict posterior access; a low portal improves the trajectory posteriorly at the expense of tighter instrumentation.
Do not force the view: improve positioning, fluid clarity or portal placement before advancing against resistance.
Inspect posterior blind spots: anterior inspection alone may miss posterior meniscal pathology, particularly in a tight knee.
Preserve orientation: moving the scope too close too early removes the wider field needed for safe triangulation.
Complete and record the survey: do not let an obvious lesion distract from examination of the remaining compartments.
(Campbell, Chapters 54 and 56.)
Complications
Iatrogenic cartilage or meniscal injury: associated with inaccurate portals, forced manipulation and instruments advanced outside the field of view.
Fluid extravasation and compartment syndrome: particular concerns when the capsule is disrupted or irrigation pressure and fluid escape are poorly controlled.
Neurovascular injury: posterior access and complex reconstruction require particular attention to local anatomy.
Hemarthrosis, infection, venous thromboembolism and tourniquet injury: remain relevant despite small skin incisions.
Stiffness and arthrofibrosis: depend in part on the underlying injury and the procedure performed.
Reported rates depend strongly on procedure complexity and the dataset. Chapter 56 cites 0.6% complications in four large series totaling 191,584 knee arthroscopies, but also reports an almost 5% rate in American Board of Orthopaedic Surgery data. These estimates should not be treated as a single risk applicable to every diagnostic survey, meniscal procedure or ligament reconstruction (Campbell, Chapters 54 and 56).
Postoperative Care
Aftercare follows the procedure actually performed. A diagnostic survey is commonly followed by meniscal, ligament or cartilage surgery, so the restrictions for that intervention determine rehabilitation. Campbell describes faster recovery after simple arthroscopic procedures than after open arthrotomy; that observation does not establish a universal weight-bearing or return-to-sport schedule for all knee arthroscopy (Campbell, Chapters 54 and 56).
References
Bernholt DL. General principles of arthroscopy. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Elsevier; 2026. Chapter 54, pp. 2300–2310.
Bernholt DL, Mihalko MJ. Arthroscopy of the lower extremity. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Elsevier; 2026. Chapter 56. Knee setup, portals and examination: pp. 2332–2337; complications: pp. 2397–2398.