Cyclops syndrome following anterior cruciate ligament reconstruction: Can relapse occur after surgery?

Abstract

Symptomatic cyclops lesions are complications that can be seen at rates of up to approximately 10% after anterior cruciate ligament reconstruction. However, recurrent cyclops lesions have rarely been documented. There are case rare series in the literature regarding the treatment of recurrent cyclops lesion. Future large studies are needed to investigate factors contributing to the development of cyclops lesions and syndrome and treatment options.

Key Words: Cyclops lesion; Cyclops syndrome; Anterior cruciate ligament; Knee arthroscopy; Relaps

Core Tip: Although anterior cruciate ligament reconstruction is a surgery with low complication rates, it may sometimes require revision surgery. One of the reasons for this is cyclops syndrome, which can lead to knee extension limitation. However, recurrence after surgery is very rare. Discussion of this rare complication is important for the management of future complications.

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction is a well-defined and common operation with very low complication rates. However, loss of knee extension that can be seen in some patients may require revision surgery. In 1990, Jackson and Schaefer detected a fibrous nodule on the ligament in a patient with loss of extension after ACL surgery. In this entity, which they call Cyclops syndrome, the impact of the nodule on the notch during extension restricts extension. It is known that this nodule develops as a result of a fibrotic process after repeated traumas[1-3]. In fact, cases with similar mechanisms have also been reported in patients who did not undergo ACL reconstruction. There are also patients who are not actually symptomatic but have positive findings on magnetic resonance imaging (MRI). Some studies report rates of up to 50% of asymptomatic MRI findings[4].

The diagnosis of cyclops lesion can be made by evaluating the postoperative clinical examination findings and MRI findings. When a cyclops lesion is detected, early surgery is the recommended method to prevent degeneration and other knee pathologies that may develop. We also know that early surgery is effective in providing range of motion[2].

When the reports published over the years are systematically examined, it is reported that symptomatic cyclops lesions can actually be seen in 2% to 11%. It is known that the use of hamstring or patellar graft does not constitute a risk factor in the development of cyclops lesion. However, there are also studies reporting that bone-tendon-bone graft is a risk factor[2,5]. In fact, the list of risk factors is long and most of time it is difficult to say which factors caused it in a case report.

In fact, the best treatment is to take precautions to prevent it from occurring, but if revision is necessary, it is to be done as soon as possible. However, performing it at least within the first year after surgery may contribute to the results. Additionally, an effective rehabilitation program should be applied after the second surgery. Delcogliano et al[6] and Eckenrode[7] reported that the results were successful in 4 and 3 patients, respectively, who were operated on within the first 1 year due to cyclops lesions. However, the results can sometimes be disappointing after all[2,8].

Although recurrence of the cyclops lesion after surgery is very rare, Kelmer et al[9] reported a case that recurred after bone-tendon-bone ACL reconstruction and required revision surgery twice. This case is a good example that shows all surgeons and physiotherapy teams dealing with ACL reconstruction the importance of precautions that must be taken to prevent this lesion from developing. The fact that full recovery occurred after two surgeries still supports that the best treatment is surgical release.

When comparing interventions performed without anesthesia and with anesthesia after the cyclops lesion, the results after anesthesia are better. This may indicate that compression-related pain also contributes to the etiology[1,10]. While approximately 20% to 35% of cyclops lesions are seen in second-look arthroscopy after anterior cruciate ligament reconstruction, approximately 80% of them are asymptomatic. As a result, it is a fact that asymptomatic lesions do not require intervention, and authors agree that surgery is required for cyclops lesions. However, there is still a need for comparative studies.

CONCLUSION

In conclusion, recurrence may occur after cyclops lesion surgery, although very rarely. future larger studies are needed to better understand what factors contribute to the development of cyclops syndrome and the etiology of recurrent cases. In addition, comparison results of different treatment modalities may contribute to determining the gold standard management method.