Endoscopic Bertolotti Syndrome Resection

At the base of the spine, some people are born with a transitional vertebra: the lowest lumbar vertebra is partly "sacralised", with one or both transverse processes enlarged. When an enlarged transverse process meets the wing of the sacrum, it can form a false joint — a pseudoarticulation — rather than fusing solidly, and in a proportion of people that false joint becomes painful, typically producing low back pain felt to one side and often worse on bending or twisting. This is Bertolotti syndrome. It is frequently missed because the anatomy is dismissed as an incidental scan finding, so the single most important step before any surgery is confirming that the false joint is genuinely the source of the pain — most reliably with a targeted diagnostic injection into it.

Where the false joint is confirmed as the pain generator and non-operative measures have not helped, the operation resects it: the enlarged transverse process and the abnormal pseudoarticulation are removed, so that the painful joint no longer exists. Done endoscopically, this is a focused keyhole procedure. The endoscope is docked directly onto the pseudoarticulation through a small portal, and the abnormal bony bridge is taken down with a fine burr under continuous irrigation and magnified vision, with care to protect the nearby L5 nerve, which runs close by. The aim is to free the painful joint completely while disturbing as little of the surrounding muscle and bone as possible.

The pseudoarticulation is a small, deep, out-of-the-way target, and reaching it through open surgery means a fair amount of muscle dissection. A targeted endoscopic approach goes straight to the spot with far less collateral disturbance, which suits what is essentially a focused bone-resection task in a young, otherwise healthy patient. I am careful, though, to be candid about selection, because it is everything in this condition: the anatomy is common and not always the cause of a person's pain. Thorough assessment, imaging and a confirmatory injection guide the decision, and in some cases — particularly where there is associated instability — a fusion rather than a simple resection may be the better option. Making that judgement openly with each patient is central to good care.

The evidence on Bertolotti syndrome comprises reviews, classification systems and surgical series rather than large trials. Classification work relating the exact anatomy of the transitional vertebra to the best treatment has helped guide whether resecting the pseudoarticulation or fusing is more appropriate. Surgical series of resection — including minimally invasive tubular and microendoscopic approaches, and more recently full-endoscopic resection of the pseudoarticulation — report meaningful improvements in pain and quality of life in well-selected patients, while consistently emphasising the importance of confirming the false joint as the pain source first. Longer-term comparative work using anatomical classification to choose between resection and fusion supports individualising the operation to each person's anatomy, which is exactly my approach.

Because the endoscopic approach is a targeted keyhole, recovery is generally quicker and more comfortable than an equivalent open resection, with relief of the localised back pain expected as the false joint is removed. It is honest to say that outcomes depend heavily on correct selection — on the pseudoarticulation genuinely being the source of the pain. Activity is built back up over the following weeks, and the spine is followed up over the longer term.

• —Endoscopic resection of the pseudoarticulation as a treatment for Bertolotti's syndrome. (PMID 36751158 / PMC9897682)
• —A review of symptomatic lumbosacral transitional vertebrae: Bertolotti's syndrome. (PMID 26484005)
• —Redefining the classification for Bertolotti syndrome: anatomical findings guide treatment selection. (PMID 36965661)
• —Minimally invasive tubular resection of the anomalous transverse process in Bertolotti's syndrome. (PMID 24358999)
• —Quality-of-life and satisfaction following pseudoarthrectomy in Bertolotti syndrome. (PMID 35189349)
• —Long-term outcomes using the Jenkins classification to determine treatment of transitional vertebrae in Bertolotti syndrome. (PMID 36898630)