Arthroscopic Posterior Capsular Releases for Recalcitrant Arthrofibrosis

Video Transcript

In the following video, we demonstrate our technique for performing arthroscopic posterior capsular releases for recalcitrant arthrofibrosis of the knee to correct a persisting extension deficit. This is a brief overview of the video. Of note, the technique video was performed on a cadaveric model.

Background

The rate of persisting arthrofibrosis after knee surgery can be as high as 38%, depending on the nature of the injury and procedure performed.^2,4,5,7 Factors that may increase the arthrofibrosis risk include, but are not limited to, prolonged periods of immobilization, the timing between the initial injury and surgery, preoperative knee inflammation contributing to decreased range of motion, and the initial traumatic injury itself.^4,9 Symptoms and deficits typically seen include decreased range of motion, increased pain and stiffness, and decreased knee function. ¹¹ We will be highlighting a technique aimed at correcting persistent extension deficits.

This is a case of an 18-year-old male who presented with right knee pain and stiffness. He underwent an anterior cruciate ligament (ACL) reconstruction (ACLR) 2 years prior at another institution. Since the initial ACLR, the patient demonstrated a persistent extension deficit, which failed both nonoperative and operative management. Physical examination demonstrated a 15° flexion contracture, with full knee flexion. The remainder of the physical examination was unremarkable.

Preoperative magnetic resonance imaging demonstrated an intact ACL graft. However, diffuse synovitis was noted throughout the knee joint with signs of fat pad fibrosis. Furthermore, the popliteal artery was noted to be situated approximately 3 mm posterior to the posterior horn of the lateral meniscus, just superficial to the posterolateral capsule.

Indications

Arthrofibrosis is initially treated conservatively with increased weekly physical therapy, dynamic extension splinting, and the use of corticosteroids.^4,6,8 If conservative management fails, arthrofibrosis can be operatively treated with an arthroscopic lysis of adhesions and synovectomy, as well as a manipulation under anesthesia.^1,3,4,8,10 In cases with severe flexion contractures of greater than 10°, additional posterior capsular releases can be performed to restore full knee extension. ⁸

Technique Description

With the camera in the anterolateral portal and the knee flexed to 90°, a switching stick is placed in the anteromedial portal and advanced right under the posterior cruciate ligament (PCL), just above the posterior horn of the medial meniscus, and carefully advanced into the posteromedial gutter. The camera is then removed, and the camera sleeve is inserted over the switching stick and slid just past the condyle. Once the sheath is in the appropriate position, the 30° scope is then placed in the anteromedial portal.

Using blunt palpation, the posteromedial aspect of the knee is palpated until movement of the capsule is visualized. A spinal needle is first used to mark the posteromedial portal. A small incision is then made with an 11-blade directly over top the needle and followed into the joint. Next, the posterior aspect of the posterior horn of the medial meniscus is identified. Care must be taken not to detach any of the meniscal attachments on the back of the tibia. Therefore, the posteromedial capsule release should be performed approximately 5 to 10 mm posterior to the posterior border of the posterior horn of the medial meniscus.

Starting at the portal, the capsule is slowly released medial to lateral, going from superficial to deep until the entire capsule is released. Once the capsule is released, the semimembranosus and sometimes the semitendinosus can be visualized. The scope is pulled back until the edge of the PCL fibers can be visualized, where the release continues.

In some cases, there may be a high takeoff of the popliteal artery, resulting in an aberrant anterior tibial artery. The artery here can be seen running deep to the popliteus along the PCL facet. Care must be taken not to transect the artery when performing the release posterior to the PCL. Thorough assessment of preoperative imaging is crucial to avoid iatrogenic vascular injuries.

The 30° scope is then exchanged for a 70° scope to improve visualization behind the PCL. Of note, in cases of arthrofibrosis where the entire back of the femur is immobile, the 70° scope is necessary for the superior release. Once the femoral attachment of the medial head of the gastrocnemius is identified, the superior release is started medially and proceeds laterally. If necessary, it is acceptable to detach a small portion of the gastrocnemius tendon, as it has a broad attachment point.

Next, the attention is directed to the posterolateral capsule release. Oftentimes, the anterolateral portal can be used to position the scope optimally for posterolateral visualization. However, an accessory transpatellar tendon portal may be necessary to allow for better positioning right next to the ACL, just above the posterior horn of the lateral meniscus.

With the same steps as before, the scope is advanced just passed the condyle. Extreme caution must be taken not to place the switching stick or the sleeve past the capsule, as the popliteal artery sits right behind the posterior horn of the lateral meniscus. Once the camera is positioned in the posterolateral aspect of the knee, a posterolateral portal is established. The “soft spot” can be easily palpated between the anterior border of the biceps femoris and the posterior border of the iliotibial band with the knee in flexion. Care must be taken not to transect the biceps femoris tendon when establishing this portal.

Starting 5 to 10 mm posterior to the posterior aspect of the posterior horn of the lateral meniscus, the release begins at the portal. The popliteus tendon can be visualized wrapping around the femur laterally. Sometimes, the musculotendinous junction of the popliteus can be appreciated here. Therefore, care must be taken not to release directly over the tibia to remain superficial to the popliteus tendon and muscle belly. Capsular dissection is taken laterally, proceeding medially. Of note, a transseptal approach can be done. However, in the setting of arthrofibrosis, where the capsule is extremely scarred, it may be too dangerous to dissect posterior to the PCL when the capsule and popliteal artery are extremely close.

With the use of the 70° scope turned upward, superior capsular release off the femur can be achieved until the lateral head of the gastrocnemius is uncovered. Like the medial side, it is acceptable to detach a small amount of the lateral gastrocnemius. At this point, arthroscopy is terminated, and the manipulation under anesthesia is safely performed.

Here are some intraoperative photos from our case. In severe arthrofibrosis, as seen here, the back of the knee is typically extremely tight. This may make overall maneuverability challenging. Furthermore, given the proximity of the popliteal artery to the posterior horn of the lateral meniscus, the decision was made to perform the lateral release first.

This is following the lateral posterosuperior release. The gastrocnemius tendon was partially released as seen here. This was done initially to allow for more room for the inferior release.

The photo here on the left demonstrates the radiofrequency (RF) wand just posterior to the popliteus tendon. The excessive amount of scar tissue is noted to be posterior to the lateral meniscus. The photo on the right demonstrates complete release of the inferior posterolateral capsule all the way distal to the popliteus musculotendinous junction. Given the proximity of the arthrofibrosis to the popliteus muscle and tendon, care must be taken not to ablate too anteriorly as not to compromise the popliteus.

Here we can see the before-and-after images of the inferior posteromedial release. The semimembranosus tendon can be appreciated just inferomedially to the RF wand on the photo on the right.

Here we can see the extent of the inferior posteromedial release with the 70° scope viewing just posterolateral to the PCL.

This is an example of the extent of the superior posteromedial release, with some intentional detachment of the medial gastrocnemius tendon, as seen on the right.

Preoperatively, the patient had a 15° extension deficit measured on a goniometer. After the posterior capsular releases, the patient gained 20° of terminal extension, resulting in 5° of hyperextension.

Results and Discussion

This table summarizes the advantages and disadvantages. This technique is minimally invasive and provides direct visualization of the posterior gutters, ensuring complete release. However, this technique is challenging with a steep learning curve and requires strong knowledge of the regional anatomy to decrease the risk of iatrogenic injury. Additionally, failure to completely visualize the entirety of the posterior capsule may result in an incomplete release. Lastly, new RF technology assists in mitigating the risk of articular cartilage damage.

Physical therapy begins immediately after surgery with the addition of daily exercises to be performed at home. Physical therapy includes extension bracing, active and passive range of motion, and quadriceps activation. A continuous passive motion machine may also be used in the postoperative period for the first 2 weeks. Complete return to sport is typically achieved by postoperative month 6.

Postoperatively, the patient has full knee range of motion, with no signs of a persisting extension deficit. Furthermore, we can see the patient ambulating with full extension and no evidence of a flexion contracture gait.

We have reported patient outcomes with this specific technique in 22 patients with a median age of 37 years following posterior capsular release. ⁸ The most common initial procedure performed in this patient cohort was ACLR. Patients were included if they had failed 3 months’ worth of conservative management consisting of extension splinting, an increase in their physical therapy regimen, and, in some cases, use of corticosteroids. Before posterior capsular release, patients lacked a median of 15° of knee extension. Full knee extension was achieved postoperatively and maintained at final follow-up. Knee function, as well as activity and pain levels, significantly improved at final follow-up.

Additional studies have shown that performing arthroscopic posterior capsular releases within 6 months of the primary surgery has led to improved subjective and objective outcome measures. ³ Furthermore, Brinkman et al ¹ found that arthroscopic posterior capsular releases were beneficial in competitive athletes. Overall, performing this procedure in patients with persistent extension deficits has improved patient outcomes.^1,3,8,10