Abstract
Background:
Cyclops lesion after anterior cruciate ligament (ACL) reconstruction can appear on magnetic resonance imaging (MRI) in up to 30% of patients and is symptomatic in up to 9%. Arthroscopic cyclops removal can help restore motion and limit recurrence.
Indications:
Patient is an 18-year-old male high-level collegiate athlete with a mechanical block to full extension. Patient underwent ACL reconstruction with bone–patellar tendon–bone autograft 15 months prior by an outside physician. The patient had a stable Lachman and pivot-shift examination, but there was a palpable clunk when attempting to extend his knee the final 10°. Patient was unable to perform sport due to symptoms. Postoperative MRI demonstrated a large cyclops lesion.
Technique:
Bilateral ligamentous examination under anesthesia was performed prior to draping. Standard arthroscopy portals were used. Diagnostic arthroscopy was performed by assessing all critical structures in the knee (ie, meniscus, cartilage, and ligaments). The cyclops lesion was visualized in the intercondylar notch with clear evidence of superior notch impingement with knee extension. Using a standard shaver and radiofrequency ablation, the cyclops lesion was resected with care not to injure the ACL graft or disrupt its integrity. A small superior soft tissue resection was then performed with resection of scar tissue that had formed within the notch. A repeat examination with an arthroscope in the knee revealed no further impingement.
Results:
Patient was able to return fully to sport at 8 weeks postoperatively with no limitations, with no return of clicking or loss of motion.
Discussion/Conclusion:
Symptomatic cyclops lesion after ACL reconstruction can be effectively treated with arthroscopic debridement. Postoperatively, patients can return to full sport at 6 to 8 weeks.
Patient Consent Disclosure Statement:
The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
This is a visual representation of the abstract.
Video Transcript
In this video, we describe the surgical technique of an arthroscopically assisted excision of a cyclops lesion after anterior cruciate ligament (ACL) reconstruction in an elite college athlete.
The authors have no relevant disclosures for this video. Complete disclosure information can be found on the American Academy of Orthopaedic Surgeons website.
Background and Indications
Cyclops lesion is a known complication of ACL reconstruction and was initially described by Jackson and Schaeffer 4 in 1990. These lesions can occur on magnetic resonance imaging (MRI) in up to 47% of patients and become symptomatic, leading to patellar clunk syndrome in 10% of individuals.1-6 Patellar clunk syndrome demonstrates a mechanical block to extension with or without an audible clunk and decreased range of motion, specifically terminal extension. The literature demonstrates a recurrence rate of less than 1% after arthroscopic excision. 1
In this case report, we present an 18-year-old male collegiate football player who underwent an ACL reconstruction with bone–patellar tendon–bone autograft at an outside facility 15 months prior. The patient demonstrated a mechanical block to full extension with a palpable clunk after forceful extension. The patient was able to perform limited duties but was unable to participate fully in sport. The examination demonstrated a grade 1A Lachman test and negative pivot-shift test. All other ligamentous testing was stable.
This clinical video demonstrates the patient's mechanical block to full extension, and an audible clunk can be heard with forceful extension.
Patients radiographic imaging demonstrated neutral alignment with appropriate tunnel position placement. Of note, the patient underwent femoral nailing as an adolescent for femoral fracture.
A sagittal T2 MRI demonstrates no evidence of medial meniscal tear, an intact ACL graft, large anterior cyclops lesion with stalk, and no lateral meniscal tear.
Given this patient's age and status as an elite athlete, combined with his mechanical block to motion and inability to fully perform his sport, it was our recommendation for him to undergo an arthroscopically assisted procedure for excision of his cyclops.
An extensive discussion was had with both the patient and his family regarding his return to play, prognosis, risks, and benefits.
Technique Description
In the operative suite, the patient was placed in the supine position on a standard operating room table. A lateral side post was used along with a foot bump set to 90° of knee flexion. A thigh tourniquet was placed but not inflated during the case. A full examination under anesthesia was performed. This included evaluation of range of motion, collateral ligament stability, posterior drawer test, Lachman's examination, and pivot shift. The patient's examination demonstrated a ligamentously stable knee.
Using standard medial and lateral portals, a complete diagnostic arthroscopy was then performed with a thorough evaluation of the patellofemoral joint and cartilage, medial and lateral gutters for loose bodies, medial compartment, and lateral compartment. Careful attention was paid to the meniscal roots, and a full run of the medial and lateral condyles was performed.
After completion of the diagnostic arthroscopy, the cyclops lesion was visualized within the intercondylar notch. A probe was used to fully evaluate the extent of the cyclops. The ACL graft was intact posterior to the cyclops lesion. A dynamic examination with the arthroscope in the knee demonstrated a mechanical block to full extension. Using an arthroscopic shaver and electrocautery, the cyclops lesion was excised with care to avoid any injury to the ACL graft. The cyclops tissue was excised, and the intermeniscal ligament was used as a guide for resection anteriorly. After excision of the cyclops lesion, it was noted there was a moderate amount of scar tissue formed within the intercondylar notch. Using a shaver and electrocautery, the scar was resected to avoid any further mechanical block to full extension. A dynamic examination with the arthroscope in the knee after resection demonstrated full extension without any impingement.
Results and Discussion
Potential complications of the procedure include inadequate resection of the lesion and iatrogenic damage to the intact graft, leading to potential rerupture and/or instability. Without adequate resection, the patient can experience the same symptoms postoperatively, including a mechanical block to motion and a clunk. After any arthroscopic procedure, postoperative stiffness is always a risk. For this elite athlete, avoiding quad atrophy in the postoperative period would allow him to return to his sport quicker.
Our initial postoperative rehabilitation includes immediate weightbearing as tolerated with the use of crutches as needed until gait is normalized. We begin immediate physical therapy for range of motion to avoid any stiffness. Initially, our goal is to gain full extension and normalize the gait.
In our athletes, our return to sport criteria are demonstrated here. The athlete should be nearly pain free with no effusion and range of motion nearly equal to the contralateral limb. The athlete's International Knee Documentation Committee score should be greater than the gender-predicted norm. Prior to returning, we require the lower extremity strength of the operative limb to be >90% of the contralateral leg and the hamstring to quad strength ratio >75%. We also require a Functional Lower Extremity Evaluation (FLEE) test composite score >90%.
Our patient was able to compete fully in a collegiate practice at 7 weeks postoperatively. He participated fully during the season with no complications or recurrence of symptoms. The literature supports early return to play and overall positive outcomes after excision of cyclops lesions, with only 1 documented recurrence following resection.7,8
Our references are demonstrated here. Thank you, and please feel free to contact the lead author with any questions or concerns.
Footnotes
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
