Abstract
Surgical treatment of recalcitrant patellar tendinopathy includes both the open surgical approach and minimally invasive arthroscopic debridement. A variety of arthroscopic techniques have been described that involve the use of a standard 30° arthroscope and standard anterolateral and anteromedial portals. As a result, visualization of the infrapatellar region can be variable, and it may be necessary to create additional portals. A 70° arthroscope provides the advantage of a wider field of view to the surgeon. By placing a 70° arthroscope through a superolaterally created portal around the knee joint, the surgeon acquires a complete view of the infrapatellar region and patellar tendon. Thus, debridement of the pathologic area can be accomplished just by the use of an additional working portal, typically the anterolateral one. This technical note describes a technique that involves the use of a 70° arthroscope for the treatment of patellar tendinopathy.
Patellar tendinopathy presents with typical features of overuse tendinopathy. Almost universally, it is manifested at the inferior pole of the patella and involves the superior, posterior part of the patellar tendon and the surrounding tissues. It is especially predominant in jumping athletes such as basketball players; its prevalence has been previously reported to be as high as 45%, particularly in sports involving high degrees of jumping. This has led to the widely used pseudonym “jumper's knee.”1 Infrapatellar synovitis, hypertrophy of the infrapatellar fat pad of Hoffa, and neovascularization constitute the pathognomonic findings of this clinical entity. The inflammatory and hypertrophic changes affect the tissues surrounding the patellar tendon. The affected tendon itself presents with mucoid generation and under light microscopy demonstrates abnormal collagen, tenocytes, and vasculature.2, 3, 4, 5, 6
Treatment modalities for this usually recalcitrant tendinopathy involve a range of approaches, from physiotherapy and platelet-rich plasma injections to surgical treatment. As far as surgical treatment is concerned, both open debridement of the patellar tendon and minimally invasive arthroscopic treatment have been described. Clinical results for both procedures for treatment of chronic patellar tendinosis have been good, ranging from 87% to 91%.7 Postoperatively, patients were free of complaints or had minor discomfort not affecting their level of activity. However, there is evidence to suggest that arthroscopic debridement may lead to a significantly faster return to sports and preinjury levels of activity.7 There is significant controversy regarding the extent of debridement and whether this should involve a bony resection of the inferior patella (osteoplasty) as well. The arthroscopic approach for the treatment of chronic patellar tendinopathy provides rates of symptomatic pain relief varying from 60% to 100%. The differences reported in outcomes may be associated with different approaches and philosophy regarding the extent of peripatellar tendon debridement and osteoplasty.8, 9, 10, 11, 12
In 2 separates studies, Lorbach and associates have tried to resolve the debate regarding the necessity for inferior patellar osteoplasty and have concluded that it may actually benefit outcomes, as far as patient symptoms are concerned.9, 13 In other studies, the arthroscopic osteoplasty of the lower patellar pole has produced favorable clinical results, allowing a fast return to sporting activities in cases presenting with chronic patellar tendinopathy.14, 15
A variety of arthroscopic techniques have been described with regard to the extent of debridement and the associated outcomes. To our knowledge, all reported techniques involve the use of a standard 30° arthroscope in conjunction with standard anterolateral (AL) and anteromedial portals and a number of accessory portals. In this study we describe a technique that involves the use of a 70° arthroscope. The arthroscope is placed through a superolateral (SL) portal 2.5 cm from the superior lateral corner of the patella. This provides a bird's-eye view of the patellofemoral joint and clear viewing of the entire inferior pole of the patella and the proximal patellar tendon. All the instrumentation used for decompressing the inflamed infrapatellar area is subsequently inserted through an AL working portal, in typical fashion. Although the senior author (V.M.) has previously described the advantages regarding the use of the 70° arthroscope for correct placement of the femoral tunnel in anterior cruciate ligament reconstruction,16 we believe that its application can also provide an excellent view of the infrapatellar area when it is combined with an SL portal.
Surgical Technique
The key points of the technique are summarized in Table 1, and the technique is demonstrated in Video 1.
Table 1.
Summary of Procedural Steps: Main Technical Points
| Preoperative imaging with x-rays and magnetic resonance in order to assess the extent of tendon involvement |
| Use of a 30° arthroscope through a standard anterolateral (AL) portal for initial assessment of the knee joint |
| Creation of superolateral (SL) portal with needle technique under direct arthroscopic visualization |
| Switch to 70° arthroscope through SL portal, which allows detailed assessment of infrapatellar pathology |
| Demarcation of pathologic area around proximal patellar tendon with needle technique under direct arthroscopic visualization |
| Use of AL portal for the insertion of instruments required for debridement of pathologic area |
| Superior, clear view of the entire width and depth of the infrapatellar region by using the 70° arthroscope from the SL portal |
| No need for additional accessory portals, anteromedial or low anterior portals |
Patient Positioning
The patient lies in supine position. The limb is prepared and draped after application of a thigh high tourniquet.
Preoperative Equipment Setup
The initial intra-articular assessment can be performed with a standard 30° arthroscope through an AL viewing portal. We typically use a Stryker arthroscopy stack (Kalamazoo, MI). Rapid switching between the 30° and 70° arthroscopes is facilitated with the use of Clinicon quick-change camera drape (P3 Medical, Bristol, England), which can be mounted to a 4.0-mm, 30° or 70° arthroscope (Olympus, Center Valley, PA). The use of the quick-change camera drape means that only one camera is needed. For pathologic tissue debridement, a straight 4.5-mm shaver blade (Smith & Nephew, Dyonics) is typically used. Additionally, debridement with a 90° bipolar radiofrequency (RF) ablation probe can be performed, particularly in those cases where there is excessive neovascularization of the pathologic, inflamed tissue.
Creation of AL Portal and Intra-articular Inspection
A standard AL portal is created, and the entire intra-articular space is inspected for any pathology. In this stage a 30° arthroscope is used.
SL Portal and 70° Arthroscope
After visualization of the entire joint with the 30° degree arthroscope, an accessory SL portal is created. In typical fashion, an outside-to-inside needle technique is used under direct arthroscopic inspection to obtain optimal portal placing.
At this stage, the 30° arthroscope is exchanged for the 70° arthroscope by using the quick-change camera drape. The proximal part of the patellar tendon is identified and visualized throughout its entire width. Figure 1 demonstrates the view obtained with a 70° arthroscope from the SL portal. This bird's-eye view allows for clear identification of the inflamed, pathologic tissue and facilitates its removal up to healthy tendon margins. Furthermore, by palpating the patellar tendon from the outside and inserting a needle at its lateral and medial borders, it is easier to demarcate and define the exact width of the tendon, which can sometimes be obscured by the inflamed synovial tissue and the fat pad (Fig 2).
Fig 1.
(A) Left knee arthroscopic view. The patellofemoral joint is viewed through the superolateral portal with a 70° arthroscope. The proximal patellar tendon pathology is visible (black arrow). (B) The T1 weighted image reveals marked thickening and increased signal intensity in the patellar tendon (red arrow).
Fig 2.
The surgeon is demarcating the coronal width of the left patellar tendon under direct visualization, with the 70° arthroscope placed in the superolateral portal. This is achieved by means of direct palpation of the tendon by the surgeon and inserting a needle at the most lateral and medial border of the tendon. Thus, the working area is recognized (left-right arrow) and the surgeon can proceed to debridement. This step is often advantageous because the inflamed tissue blocks the direct view to healthy patellar tendon.
Decompression and Debridement
Debridement of the degenerative tissue at the proximal border of the patellar tendon can then be accomplished through introduction of arthroscopic shavers through the AL portal. The extent and depth of debridement can be safely controlled by the wide, SL view of the 70° arthroscope. The pathologic synovium is debrided with a steady, swiping movement of the shaver from the proximal to distal direction (Fig 3). The surgeon controls repeatedly the depth of resection in order to avoid accidental removal of healthy tendon material (Fig 4). The limits of the coronal width of the resection can be recognized by using the aforementioned needle technique. Removal of the inferior border of the most distal pole of the patella (osteoplasty) depends on surgeon's preference. Furthermore, an RF wand can additionally be used to debride and coagulate inflamed tissue with neovascularization.
Fig 3.
Debridement of left proximal patellar tendon with straight arthroscopic shaver. This is achieved through the working anterolateral portal. (A) The procedure is performed under visualization with a 70° arthroscope placed in the superolateral viewing portal. The targeted, pathologic infrapatellar region is visible. The arthroscopic shaver is introduced through the working portal. (B) Debriding with swiping movements of the arthroscopic shaver from proximal to distal causes the healthy proximal patellar tendon to become visible. Viewing and working portals remain unchanged throughout the procedure.
Fig 4.
Superolateral view of left patellar tendon through a 70° arthroscope. After decompression and removal of degenerative tissue, the healthy patellar tendon is visible (arrow).
Discussion
Although there are a number of studies describing the application of arthroscopic techniques for the treatment of patellar tendinopathy, this technical note describes such a technique with the combined use of an SL portal and a 70° arthroscope. In other studies, the use of an SL portal has been reported; however, it has been used in conjunction with multiple other portals, including accessory anterior-inferior and standard anterior portals, along with a 30° arthroscope, in order to achieve satisfactory viewing angles.14
As described previously by the senior author (V.M.), there are advantages in the use of a 70° arthroscope, in order to achieve a clear view for the anatomic placement of the femoral tunnel.16 In the currently described technique, the use of a 70° arthroscope through an SL portal provides, in addition, an excellent view of the entire length and width of the proximal patellar tendon and better definition of the associated infrapatellar pathology.
Correct placement of the SL portal is important in order to achieve a complete, wide view of the entire infrapatellar region and ablates the need for additional portals. Palpation of the patellar tendon and insertion of a needle at its most lateral and medial portal can help demarcate its width in cases of particularly inflamed synovial tissue and/or hypertrophic Hoffa's fat pad.
Healthy patellar tendon constitutes the landmark for the extent of our debridement technique. Typically an arthroscopic shaver is used to remove the inflamed tissue. We do not habitually resect bony tissue at the inferior pole of the patella (osteoplasty) unless there is evidence of reactive bone formation at the area of chronic inflammation. Key concepts and technical recommendations of the procedure are illustrated in Table 2.
Table 2.
Important Technical Pearls
| The use of a 70° arthroscope as well as correct placement of the superolateral (SL) portal are pivotal for obtaining good views. |
| The SL portal is located lateral to quadriceps tendon, approximately 2 cm superior to the SL corner of the patella. |
| Determine the coronal width of the proximal patellar tendon by palpating the tendon and inserting a needle at the most lateral and medial edge of the tendon. |
| Avoid aggressive tissue resection in order not to traumatize the healthy tendon. |
The advantages of the described technique are that it is technically nondemanding and allows the surgeon to obtain a complete view of infrapatellar anatomy through a unique viewing portal. There is no need to switch between viewing and working portals or to create additional accessory portals. The potential disadvantages of the technique are the requirement for additional new equipment and the need to switch from a 30° arthroscope to a 70° arthroscope after initial joint inspection and assessment. Also, the routine use of the 70° arthroscope may be associated, initially, with a short learning curve. The advantages and disadvantages of the technique are summarized in Table 3.
Table 3.
Advantages and Disadvantages of the Technique
| Advantages | Disadvantages |
|---|---|
| Comprehensive, wide view of the pathology of the proximal patellar tendon | Additional equipment is needed (70° arthroscope) |
| No need for additional portals (one viewing and one working portal are needed) | There is a short learning curve associated with the use of a 70° arthroscope |
| No need to switch between viewing and working portals | Correct placement of superolateral portal is needed in order to obtain good views |
| Technically nondemanding |
Overall, the use of a 70° arthroscope with an SL portal provides a complete, clear view of the entire infrapatellar pathology that is necessary for the comprehensive debridement of the inflamed tissue involved in patellar tendinopathy.
Footnotes
The authors report that they have no conflicts of interest in the authorship and publication of this article.
Supplementary Data
Arthroscopic debridement of left proximal patellar tendon with a 70° arthroscope. The patient is in the supine position under general anesthesia, and a high thigh tourniquet is applied. Description of the setup and arthroscopic equipment required to perform the procedure is included. The 70° arthroscope is viewing through the superolateral, portal while a standard anterolateral portal is the working portal. The coronal width of the patellar tendon is visualized with the use of tendon palpation and needle insertion technique. Debridement is carried out by the use of arthroscopic shaver through the working portal. The whole procedure is performed under viewing through the superolateral portal, and there is no switching between working and viewing portals. This technique provides superior visualization of the pathologic area and is fast and safe by avoiding instrument crowding through the standard portals.
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Associated Data
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Supplementary Materials
Arthroscopic debridement of left proximal patellar tendon with a 70° arthroscope. The patient is in the supine position under general anesthesia, and a high thigh tourniquet is applied. Description of the setup and arthroscopic equipment required to perform the procedure is included. The 70° arthroscope is viewing through the superolateral, portal while a standard anterolateral portal is the working portal. The coronal width of the patellar tendon is visualized with the use of tendon palpation and needle insertion technique. Debridement is carried out by the use of arthroscopic shaver through the working portal. The whole procedure is performed under viewing through the superolateral portal, and there is no switching between working and viewing portals. This technique provides superior visualization of the pathologic area and is fast and safe by avoiding instrument crowding through the standard portals.