Open Surgery - details
There are several types of open surgery, including the following:
Open Surgery by means of a dorsal approach
This remains our preferred technique when conservative care and less invasive procedures like cryosurgery and radiofrequency have been unsuccessful. By making the incision on top of the foot, there is far less chance of a painful scar forming. We have relatively low complication rates with this procedure, although these are higher than cryosurgery and radiofrequency. The local anaesthetic is no more painful than a dental injection and is administered under ultrasound to ensure the best accuracy. The foot will generally stay numb for a minimum of six hours after surgery. However, most patients find that the local anaesthetic will last much longer. The procedure typically takes about half an hour and we remove the stitches at two weeks. After this time, patients can go back to work, however returning to sport activities is not advised for about two months. For patients who have previously had surgery, an incision at the bottom of the foot may be required to access the nerve. In these cases, the patient will not be able to weight bear for three weeks, which will help a smooth, fine scar to form that is unlikely to irritate. We use various specialised dressings to minimise the chance of painful scar formation. Our success rate from open surgery is high and none of our patients have encountered complications such as stump neuroma. However, there is a recognised increased risk with open surgery compared to less invasive treatments such as cryosurgery and radiofrequency. Recovery from open surgery also takes longer than these other treatments. For this reason, we would generally only recommend open surgery when cryosurgery and radiofrequency have been unsuccessful. Please bear in mind that at least 70 per cent of our patients have a successful outcome from cryosurgery and those who don't have a very good chance of responding to ablative radiofrequency. Therefore, very few of our patients require an open procedure.
Open surgery with a plantar approach
This procedure involves removing the nerve (and often releasing the intermetatarsal ligament) through an incision underneath the foot. It is usually performed under local anaesthetic. Some surgeons prefer this procedure because the neuroma is closer to the underside of the foot and can therefore be located more easily. Also, a larger section of nerve can be removed as the nerve can be traced further back into the foot. Despite this, we will only perform a plantar incision during revision surgery if a dorsal surgical approach has previously failed. This is because a plantar incision can result in a painful scar that can often be more painful than the original neuroma. Such a scar can be very challenging to fix, although we use a number of specialist techniques to minimise the risk. This includes specific forms of plastic surgery suturing (stitching) and anti-scar dressings.
Releasing the intermetatarsal ligament
With this technique, a small incision allows us to release the intermetatarsal ligament. A Morton's neuroma forms because it is compressed against this ligament as the toes bend. We sometimes carry out a ligament release with the help of a small surgical camera. In some cases, we make a small incision by "feel" whilst in others we open the foot in order to see the ligament. Whilst positive results have been reported, we have some reservations about this procedure. Nerve decompressions are common in other parts of the body, but those parts are not compressed by a shoe and are therefore more likely to respond. The procedure involves cutting deeper tissue, which causes some scar formation. If unsuccessful, further surgery would increase scarring. In our opinion, performing a release in combination with excising the nerve maximises the chance of success. It is important to bear in mind that an open surgery procedure is only suitable for patients who have failed to respond to cryosurgery and radiofrequency, which suggests their problem is particularly resistant to treatment.
Metatarsal osteotomyMetatarsal osteotomy
This operation involves cutting the metatarsal bone to reduce pressure on the neuroma. This type of surgery could be considered for patients who have a very narrow intermetatarsal space as confirmed by x-rays. However, we do not believe it should be used as a standard treatment for all forms of Morton's neuroma regardless of cause. A metatarsal osteotomy may be suited to patients who have suffered metatarsal bone fractures with secondary nerve compression. We tend to avoid performing lesser metatarsal osteotomies for Morton’s neuroma because they can be associated with an increased risk of transferring pain onto other metatarsals (transfer metatarsalgia) as well as other complications. This operation would not stop the transverse ligament from putting pressure on the nerve. It should therefore be considered in combination with a ligament release.