Lateral Meniscus Hypermobility: Current Concepts in Pathoanatomy, Diagnosis, and Evolving Treatment Strategies

Hypermobility of the lateral meniscus (HLM) is an under-recognised yet clinically important source of knee pain and mechanical symptoms. It differs from conventional meniscal tears in that the meniscus itself remains structurally intact, while insufficiency of stabilising structures such as the popliteomeniscal fascicles, posterior capsule, and meniscotibial ligament permits abnormal translation. The distinctive anatomy of the lateral meniscus explains its greater vulnerability to instability compared with the medial side, particularly in young and athletic individuals. Patients commonly report episodic locking, catching, or giving way, but imaging findings are often inconspicuous, making arthroscopy the diagnostic gold standard. Dynamic arthroscopic manoeuvres, including probing, aspiration, and the figure-of-four test, reliably demonstrate pathological translation. Conservative measures may provide transient relief but are rarely curative, as the pathology reflects structural instability rather than degenerative change. Contemporary surgical management emphasises meniscal preservation through repair and reinforcement of meniscocapsular attachments, using techniques such as inside-out or all-inside sutures, fascicular plication, or capsulodesis. In cases of fascicular deficiency, reconstruction with grafts or anchors has been described, while anterior horn hypermobility, though less common, can be effectively treated with outside-in fixation. Meniscectomy, once widely performed, is now reserved for irreparable cases given its strong association with lateral compartment degeneration. Reported outcomes following meniscus-preserving repair are consistently favourable, with high rates of symptom resolution, return to sport, and joint preservation. Therefore, HLM should be regarded as a pathology of dynamic instability that requires careful diagnostic evaluation and a surgical approach focused on stabilisation rather than resection.