An 81-year-old from Bricket Wood said she was left in agony for two and a half years after surgeons misdiagnosed her.

Tessa Alexander, of Jenkins Avenue, underwent back surgery at St Albans City Hospital in November 2011, after being diagnosed with degenerative spondylolisthesis - a condition associated with the weakening of the spine as a result of ageing.

Following the operation Mrs Alexander said she couldn't move and her had shooting pains down her legs, which the surgeons told was the result of nerve damage caused by the operation - but what made the situation worse initially was her "horrible experience" of how the hospital treated her afterwards.

Mrs Alexander said she was asked to wash herself despite not being able to move and the freezing temperatures in the ward at the time.

She said because the hospital apologised for their treatment she didn't do anything else.

However, her pain in her legs continued and she struggled to walk.

Mrs Alexander said the doctors still believed that the pain was due to the operation and she started to have spinal injections.

She said: "I was put on a cocktail of painkillers.

“The surgeons even did another X-ray and said to me 'it doesn't look like there is anything wrong with your back but we can do another operation' - but I didn't see the point of that."

After being advised by her dentist to try pilates, Mrs Alexander found out it was her hip that was causing her so much agony.

She said: "Within the first session, the instructor told me that there was nothing wrong with my back, I needed a new hip. My pilates instructor recommended Neil Davies."

Mrs Alexander phoned the hospital asking for a consultation and X-ray with Mr Davies and they told her she had to go back to her doctors and get a referral.

She added: "I got the letter to see Mr Davies and went back to Watford General, who told me I couldn't have the operation in the near future and may have to wait up to 18 weeks.

"I had been suffering from a misdiagnoses of it for two and half years. Mr Davies said he could do the operation both on the NHS or privately and in the end I couldn't wait."

In a letter to Mrs Alexander, Jacqueline Kelly, chief executive of West Herts Hospitals, which runs St Albans City and Watford General Hospitals, said: "When you [Mrs Alexander] suffered recurrent left leg pain it was reasonably presumed that this was due to irritability of the spinal nerves.

"Your symptoms settled for extended periods of up to six months consequent to three spinal injections. It is very likely that symptoms during this time were consequent to a combination of factors, and that there was a progression of symptoms from osteoarthritis of your left hip.

"In July 2014, it is likely that your hip symptoms had become dominant, but we did not appreciate this, and the diagnosis was correctly made by a physiotherapist in October 2014."

Mrs Alexander, who volunteered for the NHS Public Patient Initiative Forum at Watford General, paid nearly £11,000 for her hip replacement operation.

She continued: "I hoped to get better support, especially considering they had misdiagnosed me in the first place."

Dr Mike van der Watt, the trust medical director, said: "Our aim for every patient would be to follow national guidelines, and accordingly Mrs Alexander should have had her operation within 18 weeks – the standard ‘referral to treatment’ target for this procedure.

"She would have had access to the choose and book system via her GP. This is not determined by the hospital."

Mrs Alexander said staff had not told her about this booking system or how to access it.

Dr van der Watt also stated that Mrs Alexander requested to have the operation within two weeks, which she denies.

He added: "Unfortunately there were other patients waiting in similar or more pressing circumstances, and this was impossible. Mrs Alexander decided to have the operation privately. The NHS cannot reimburse patients in these cases."

Mrs Alexander has complained to the Ombudsman.