Partial Meniscectomy





Introduction


Knee arthroscopy is one of the most commonly performed procedures in the United States, with partial meniscectomy reported as the most frequently performed arthroscopic procedure. Arthroscopy is a minimally invasive procedure with low morbidity; however, complication rates have been reported to range from 1% to 8%. , These complications vary in severity and can lead to significant alterations in a patient’s postoperative course and rehabilitation. Small et al. analyzed the complications of 21 experienced arthroscopists and noted that the most common complications were hemarthrosis, infection, venous thromboembolic disease, and instrument failure, with an overall meniscectomy complication rate of 1.48% to 1.78%.


Preoperative planning is a critical part of a surgical procedure and helps to identify potential intraoperative difficulties and strategies to navigate unexpected intraarticular pathology. Intraoperative and postoperative complications can be divided into minor and major categories based on the morbidity experienced by the patient, and can include complications attributed to technique or patient-specific factors.


Preoperative Complications


Patients undergoing arthroscopic partial meniscectomy should undergo a thorough preoperative workup, including appropriate imaging and physical examination evaluation. Radiographs and magnetic resonance imaging (MRI) are critically evaluated to identify the morphology of meniscus tear, associated ligamentous or chondral injuries, as well as the presence of osteoarthritic changes. Imaging findings should be correlated to physical examination because patients may not be symptomatic from meniscal pathology, and further investigation should be performed to identify the root cause of the symptoms. Knee pain can be referred from the lumbar spine or sacroiliac joint pathology or can be caused by a crystalline or inflammatory arthropathy; therefore, physical examination should be used to confirm that presenting symptoms are the result of meniscus tear. Marzetti et al. found that a positive McMurray test had an 86.4% specificity for meniscus tear, whereas joint line tenderness was of little clinical utility. AV Van der Post, et al. demonstrated that the duck walk was 71% sensitive and 39% specific for medial and lateral meniscus tears (67% and 76%, respectively). Osteoarthritis is a significant contributor to knee pain and is commonly associated with meniscal tears; however, studies have not demonstrated consistent, prolonged symptom improvement with arthroscopic debridement, and most of these patients should be managed initially, and perhaps permanently, with conservative measures. Patients experiencing acute catching or locking symptoms or those with no more than early radiographic changes of degenerative disease can be considered for operative intervention after failing conservative therapies; however, Kirkley et al. reported no improvement in outcomes after arthroscopic intervention in this patient population. Patients with larger meniscal flaps were excluded from the aforementioned study and do benefit from an arthroscopic procedure to address the acute pathology. Additionally, younger patients with symptoms of less than 6 months’ duration and those with normal lower extremity alignment can be considered for operative intervention after failing an appropriate conservative treatment regimen.


Patient expectations can influence postoperative outcomes; therefore, a preoperative discussion should be had to ensure patient understanding of a standard postoperative course and the patient-specific goals for postoperative functional outcomes. Specifically, patients undergoing arthroscopic knee surgery in the setting of osteoarthritis have been shown to have a modest improvement of symptoms and functional outcomes in the immediate postoperative period (<3 months); however, these results become equivalent to conservative management (physical therapy, injections, oral medications) at long-term evaluation. Additionally, patients who receive surgical treatment have a 2- to 6-week recovery with an increased risk of venous thromboembolism (VTE) and postoperative infection. Patients should understand the small likelihood of long-term improvement, as well as the associated risks of surgical intervention. Recent evidence-based clinical guidelines from the American Academy of Orthopaedic Surgeons cannot recommend for or against the use of arthroscopic surgery for patients with knee osteoarthritis; therefore, the surgeon should perform a detailed evaluation of the patient and have a thorough discussion with the patient about his or her treatment goals and desired clinical outcomes, particularly in the setting of meniscal pathology with osteoarthritis.


Intraoperative Complications


Technical Complications


Partial meniscectomy is a minimally invasive and relatively quick procedure; however, intraoperative complications can occur. These events can be related to the arthroscopic set-up, the instrumentation, or the meniscal resection itself. The surgical set-up includes an arthroscopic fluid pump system or gravity set-up, thigh tourniquet, and well-padded lateral post or leg holder. Bomberg et al. described cases of fluid extravasation into the leg and thigh leading to compartment syndrome attributed to the use of an automated arthroscopy fluid pump. This is an uncommon complication, with a historical complication rate of 1.4%; however, careful fluid management during arthroscopy is critical, and use of a gravity inflow system may be required if soft tissue fluid extravasation is noted. Additionally, the development of modern arthroscopic fluid management systems and careful placement of inflow cannulas have further decreased the risks of this complication. Use of a leg holder, instead of a post, has also been found to increase the risk of compartment syndrome during knee arthroscopy. The leg holder should be placed loosely around the mid-thigh, ensuring that the popliteal fossa is free from compression.


Arthroscopic instrumentation has evolved to include a variety of tools that can be used for meniscal resection, including motorized shavers, radiofrequency devices, and handheld instruments. An arthroscopic surgeon must learn to use these tools safely and effectively to prevent iatrogenic damage to the articular cartilage. This can occur during entry into the knee during portal creation or during meniscal resection. Creation of the inferolateral portal should be performed first. This portal is located just lateral to the inferior border of the patella at the level of the joint line. A no. 11 blade, with the blade pointing up, is used to create the portal while the knee is in a flexed position. Initial capsular penetration should be performed in a controlled manner, using a hemostat to open the capsule and permit controlled entry of instrumentation. The inferomedial portal can then be localized with a spinal needle and created in a similar fashion as the inferolateral portal ( Fig. 1.1 ).




• Fig. 1.1


Safe creation of anteromedial portal under direct visualization. The portal is first localized with a spinal needle (A), followed by a knife cutting away from the meniscus (B) and finally a blunt hemostat to enlarge it (C). An arthroscopic probe can then be inserted into the portal and diagnostic arthroscopy performed (D).


Iatrogenic chondral damage is particularly important to avoid when addressing medial meniscus pathology. It is common to find a tight medial compartment that may require significant valgus stress to examine the posterior horn of the medial meniscus. Several techniques have been described to partially release the medial collateral ligament and provide increased access to the medial meniscus. The “pie crust” technique is the most popular and involves using an 18-gauge needle to puncture the medial collateral ligament, starting just superior to the medial joint line, in an anterior to posterior manner. A constant valgus force must be placed on the operative leg, and the surgeon will feel a give that signifies a partial release of the medial collateral ligament. Claret et al. evaluated functional outcomes after partial medial collateral ligament release and noted no detrimental outcomes in these patients. Instrument breakage is an uncommon complication associated with arthroscopic procedures and has been found to affect 0.23% of all procedures. The instrument failure can be the result of worn instruments or inappropriate use of instrumentation. The fragmented instrument should be removed, and the intraarticular piece must be found before the conclusion of the procedure. Reigstad et al. reported two instances of instrument breakage in their evaluation of 876 procedures, with one requiring arthrotomy to remove the fragment. This complication is exceedingly uncommon with newer arthroscopic instrument technology; however, if it does occur, it may lead to increased patient morbidity with longer procedure times or the need for a more invasive exposure.


The most important aspect during arthroscopic partial meniscectomy is the meniscal resection. The surgeon must be able to determine the appropriate amount of tissue that requires resection and select the correct tools to precisely remove the torn meniscal fragment. Inaccurate resection of meniscal pathology can lead to uneven edges, continued symptoms, and poor patient outcomes. Metcalf et al. describe guidelines for appropriate meniscal resection techniques. All fragments that can be pulled past the meniscal inner margin should be removed, with care taken to leave a smooth contour of the meniscal rim after resection and protect the meniscal rim and meniscocapsular junction. Arthroscopic instruments can assist in careful resection. The probe should be used to identify loose areas of tissue that require debridement, and manual resection instruments should be used for controlled resection, whereas motorized instruments can be used to remove debris and create a smooth rim. If uncertain, the meniscal tissue should be left alone to avoid overresection.


Many studies have linked excessive meniscal removal with development of degenerative changes and osteoarthritis. Baratz et al. evaluated the stress seen by the knee joint after meniscectomy and noted that loss of the medial meniscus leads to a 235% increase in peak contact pressure to the medial compartment. Increased contact stresses are associated with macroscopic and microscopic cartilage changes that can lead to surface fissuring and loss of cartilage. These biochemical and histologic changes can lead to radiographic evidence of osteoarthritis, as shown by Roos et al. Meniscal resection should be carefully evaluated in all patients, with particular attention paid to high-level athletes. Smith et al. evaluated participants in the National Football League Combine who had undergone a knee procedure and noted a 27% rate of osteoarthritic changes on MRI studies in patients who had a partial meniscectomy. This highlights the importance of balancing adequate resection and creation of stable meniscal base with overresection and predisposition to arthritic progression.


Recurrent symptoms after knee arthroscopy can be attributed to several factors, such as missed abnormalities and inappropriately or incompletely performed procedures. Performing a thorough and systematic diagnostic arthroscopy can decrease the risk of missed pathology. Kinsella et al. note that posterior meniscal root avulsions can be missed after treating a more pronounced meniscal tear. The use of the Gillquist maneuver can aid in the visualization of the posterior meniscal root and meniscocapsular junction. To perform this maneuver, the knee is flexed to 90 degrees and the arthroscope is gently passed between the medial femoral condyle and the cruciate ligaments. Extension of the knee allows passage of the arthroscope, and the posteromedial and posterolateral menisci can be visualized ( Fig. 1.2 ). Additionally, the surgeon can use techniques described earlier to improve visualization of a tight medial compartment and ensure adequate evaluation of all meniscal tissue. Retained meniscal fragments can also be a source of recurrent symptoms. These loose fragments must be removed after resection to prevent catching or locking symptoms that mimic a loose body. To facilitate fragment removal, Kale et al. suggest turning off the arthroscopic pump to decrease fragment mobility.


Jan 1, 2021 | Posted by in ORTHOPEDIC | Comments Off on Partial Meniscectomy
Premium Wordpress Themes by UFO Themes