A rare cause of lower back pain due to a congenital anomaly in the lower spine. It occurs when the last lumbar vertebra (L5) has an abnormal connection (partial or complete fusion) to the pelvic bone.

This condition can alter the biomechanics of the pelvis leading to uneven stress through the abnormal joint causing degeneration and inflammation. The connection or pseudo joint at the often-called transitional vertebra, can cause irritation or compression of the surrounding nerves, leading to chronic low back and leg pain. The symptoms can get worst with prolonged standing or sitting on the affected side and can cause debilitating spasms and stiffness.

The diagnosis can be difficult due to other degenerative joints in close surrounding and needs thorough clinical discussion and examination. Investigations like Xray, MRI and CT are needed to confirm the diagnosis and identify other possible source of pain. Image guided (Xray/CT) is often needed towards the working diagnosis and helps in delineating the symptoms.

The treatment options vary from conservative non-operative to operative and needs to be tailored during clinical discussion. Non-operative options such as lifestyle modification, physical therapy and anti-inflammatory medication is helpful in majority of cases. However, failing to these options like targeted steroid injection and radiofrequency ablation can be used to facilitate pain relief and rehabilitation.

The operative option is reserved for sever cases where all the non-operative treatments have failed. These include spinal fusion and minimally invasive KEYHOLE resection of the offending pseudo joint followed by focused rehabilitation