Arthroscopic Patellar Lateral Facetectomy

Abstract

Isolated patellofemoral osteoarthritis is relatively prevalent, with the lateral facet of the patella being the most commonly affected portion. This pathology can be a result of a patellar maltracking syndrome, patella instability, or idiopathic degenerative changes. A thorough diagnostic work-up with a physical examination and imaging studies are mandatory for a proper diagnosis and to rule out other causes of patellofemoral knee pain. These patients are often treated nonoperatively with exercises for patella mobility, intra-articular injections, braces, patellar tracking, quadriceps balance and strength, and activity modification. Patients with lateral patellar pain that is refractory to nonoperative management, and who have a clear bony deformity on the patella overriding the lateral aspect of the trochlea, can benefit from surgical intervention. We recommend an arthroscopic lateral patellar facetectomy because the joint can be dynamically assessed, treated, and re-evaluated intraoperatively to ensure that normal bony contact has been restored.

Figures

Fig 1

Physical examination of patellar mobility performed in a right knee. After the induction of general anesthesia and before the tourniquet inflation, a bilateral knee examination is performed to evaluate for any concurrent pathology and to assess for knee range of motion, patellar mobility in 45° of flexion (A) and extension (B), and instability and patellar crepitus during knee flexion.

Fig 2

The surgical limb is placed in a leg holder, whereas the nonoperative leg is flexed and held in an abduction holder to avoid undesirable obstruction during the surgical procedure. A well-padded thigh tourniquet is placed on the upper thigh of the operative leg to maintain a bloodless field. The surgical leg is prepared and draped in a sterile fashion, the leg exsanguinated, and the tourniquet inflated.

Fig 3

Image showing an arthroscopic patellar facetectomy in a right knee. After preparation of the surgical limb is complete, the knee is put in 90° flexion. A standard anterolateral portal is created (A) adjacent to the patellar tendon; a 30° arthroscope is then inserted through this portal and under arthroscopic visualization of the medial femorotibial compartment an anteromedial portal (B) is created to perform the resection of the lateral facet.

Fig 4

Arthroscopic image of the right knee showing delineation of the patellar surface to be resected with the use of a radiofrequency probe on the lateral aspect of the patella (viewed through the anteromedial portal) on a right knee. On the right, an intraoperative view of the portal setup is shown. (P, patella; RF, radiofrequency probe.)

Fig 5

Arthroscopic image of the right side showing lateral patellar facetectomy using a 5.5-mm burr. Of note, progressive resection should be performed throughout the whole surface to allow for a final smooth surface after resection. On the right-hand side, the arthroscope is shown being introduced through the anteromedial portal and the burr through the anterolateral portal.

Fig 6

Arthroscopic patellar lateral facetectomy performed in a right knee. Once the bony resection is complete, the knee is dynamically re-evaluated through flexion (A) and extension (B) for residual impingement and to assess for improvements in patellar mobility under arthroscopic visualization using a 30° arthroscope through the anteromedial portal. Patellar tracking is assessed to verify that there is no catching in flexion and that patellar mobility is improved. If any impingement does remain, it is addressed at this point.