Mandoukos v Allianz (No. 3): Can Surgery Create a Non-Threshold Injury?

Mr Mandoukos was injured in a motor accident in January 2019. He had also sustained a cervical spine injury in an earlier 2010 accident, but before the 2019 accident he continued to perform heavy construction work involving lifting, grinding, digging and use of a jackhammer.

After the 2019 accident he reported neck, shoulder and arm symptoms, could not return to his former heavy duties and underwent conservative treatment without sufficient relief. An initial medical assessment found a cervical musculoligamentous strain and an aggravation of pre-existing multilevel degenerative cervical spondylosis. Those conditions were assessed under the former statutory expression "minor injury", now called threshold injury.

Mr Mandoukos later underwent a C5/6 foraminotomy on 1 July 2020. The procedure decompressed a nerve root and involved removal of bone from the facet joints. His severe radicular arm pain improved, although some neck pain, headaches, numbness and functional restrictions continued.

The 2026 judgment followed earlier Supreme Court and Court of Appeal proceedings. In those proceedings Mr Mandoukos argued that the operation had caused a consequential injury, but the alleged surgical injury had not formed part of the medical dispute originally referred for assessment. The courts therefore did not finally determine that separate injury question.

A later medical assessment application identified the disputed injury with greater precision: injury to bone in the cervical facet joint due to the foraminotomy performed as a consequence of the 2019 motor accident. That procedural history matters. A medical assessor can only decide the medical dispute properly put before them; calling the condition simply "surgery" or a "post-operative condition" may fail to identify the anatomical injury that needs assessment.

The medical assessor accepted that the 2019 accident significantly aggravated the cervical condition, conservative treatment had failed, the operation was reasonable and necessary, the surgery was connected with the accident and bone had been removed from the cervical facet joints. The assessor treated that removal as an injury to bone and certified it as non-threshold.

Allianz obtained a review. The Review Panel also accepted that the operation was reasonable, necessary and causally related to the accident, and that bone had been removed. It nevertheless concluded that the surgery did not constitute an injury under the Act. Its reasoning placed weight on the planned and therapeutic character of the procedure, Mr Mandoukos' consent, the absence of negligence and the improvement in his symptoms.

The Panel revoked the assessor's certificate. It also recognised, however, that if the removal of bone was an injury, it would fall outside the statutory soft tissue definition and therefore would not be a threshold injury.

Schmidt AJ held that the Review Panel had made an error of law. The Panel had focused on whether the surgery itself could be labelled an injury. The correct question was whether the operation's physical or psychological consequences caused a further personal or bodily injury within section 1.4 of the Motor Accident Injuries Act 2017.

The foraminotomy required an incision, disturbance of soft tissues and blood vessels, access to the cervical spine and permanent removal of healthy bone from the facet joints. Those physical consequences were capable of constituting bodily injuries. On the facts already found by the Panel, the Court concluded that the injury to the facet joints through removal of healthy bone was a further bodily injury and was not a threshold injury.

The Court set aside the Review Panel certificate. The decision and orders were made on 31 July 2026, with the parties directed to confer about the final form of orders, including costs.

A central part of the judgment concerns the comparison used to decide whether bodily injury occurred. The Review Panel effectively compared Mr Mandoukos immediately before surgery with his condition after surgery. Because the operation improved some symptoms, it regarded the result as therapeutic rather than injurious.

The Supreme Court held that the physical comparison had to start with the body immediately before the motor accident and end with its state after the accident-related operation. Before the 2019 accident, the relevant bone was present and the facet joints were anatomically intact. After surgery, healthy bone had been permanently removed and could not regrow. Symptom improvement did not alter that anatomical change.

Consent, a therapeutic purpose and a competent operation were not answers to the statutory injury question. A procedure can successfully relieve one condition and, at the same time, cause a separate physiological change to another anatomical structure.

No. The judgment is not a rule that any operation after a motor accident automatically converts the claim into a non-threshold injury claim. The result depends on what the procedure actually did to the body and whether that consequence falls outside the current statutory definition.

Many operations involve incisions and disturbance to muscles, fascia, blood vessels and other soft tissues. Those consequences may remain within the soft tissue definition. A different analysis may arise where the evidence establishes injury to bone or a nerve, rupture of a tendon, ligament, cartilage or meniscus, permanent removal of an anatomical structure, or another identifiable injury outside the definition. The operative report and current statutory wording must be checked rather than assuming the answer from the procedure name.

A claimant must establish the causal connection between the accident, the need for surgery and the physical consequence relied upon. In Mandoukos, the Review Panel had accepted that the accident significantly aggravated the cervical condition, conservative treatment failed, the operation was reasonable and necessary, and the surgery would not have occurred but for the accident-related condition.

Another case may involve a genuine dispute about whether surgery was required because of pre-existing degeneration, the natural progression of a disease, a later accident, an unrelated condition or treatment that was not reasonably connected to the motor accident. A non-threshold anatomical consequence cannot be separated from proof that the accident caused the chain of events leading to the procedure.

For that reason, the file should distinguish the threshold injury question from the separate issues of treatment approval, causation, work capacity and permanent impairment.

A surgery-related threshold injury dispute should be built from the actual medical records. The operation name alone is rarely enough. Relevant material may include:

• the complete surgeon's operative report, including the level and anatomical structures altered
• pre-operative and post-operative imaging where it assists with the anatomical comparison
• a report identifying whether bone, nerve, tendon, ligament, cartilage or another structure was cut, removed, repaired or otherwise changed
• the treatment history showing why surgery was recommended after conservative care
• medical evidence connecting the need for surgery to the motor accident
• records addressing any pre-existing degeneration, symptoms or earlier injury
• evidence about whether the same operation would probably have occurred without the accident
• post-operative evidence about symptoms, function, work capacity and any permanent consequences

The operative report is often central because it records what the surgeon actually cut, removed, repaired or altered. A carefully framed specialist report can then explain the anatomical consequence and why the operation was required because of the motor accident.

The Supreme Court did not assess Mr Mandoukos' whole person impairment. The judgment concerned whether the surgical removal of bone was an injury and whether it was threshold or non-threshold. It did not assign a WPI percentage.

A non-threshold injury may be significant to access to a common law damages claim, but it does not establish that permanent impairment is greater than 10%. Greater than 10% WPI is specifically significant to non-economic loss. Any WPI assessment must apply the current Motor Accident Guidelines to the permanent accident-related impairment, including causation, pre-existing impairment and the effect of surgery.

Nor does a non-threshold finding establish fault, economic loss or the amount of damages. Those remain separate legal and evidentiary questions under the damages process.