For severe hallux valgus , surgery can be the last resort to correct the deviation of the toe.
This article doesn’t detail all the surgical techniques used to treat a bunion. In 1952, McBride already counted more than 50 techniques, whereas nowadays, there are over 180! However, here is an approach of the more frequent ones.
If there are as many techniques, it is mainly for the purpose of being able to provide a solution for all the different cases. By the way, it is rare to perform only one technique to correct a bunion. A global approach is usually preferred and includes several complementary techniques in order to adapt to the patient situation.
The choice of performing surgery to treat a bunion or the choice of the procedure depend on many factors:
• The foot architecture;
• The age and gender of the patient;
• The severity of the condition;
• The speed and type of evolution;
• The potential reluctance of the patient;
• The patient capacity to adapt his/her behaviour (shoes habits, weight...);
• The intensity and ambitions linked with sports activity;
• The risks entailed and the potential complications specific to each case;
• The season (spring/summer favour the aftermath of surgery due to the possibility of wearing open-toe or light shoes).
Main surgical techniques for a bunion correction
Two types of surgical interventions exist and can be associated:
• The first one targets the soft parts (tendons, ligaments) and aim to correct a moderate deformity in the metatarsophalangeal joint
• The second one concerns the bones:
o The cutting of a bone (osteotomy) allows to modify the axis of the bone;
o The fixation of two parts of a bone (osteosynthesis) by screws, pins or staples is the most frequent technique.
Several associated interventions, performed during one surgical procedure, are generally necessary to correct the complex and local deformity called hallux valgus .
Metatarsophalangeal arthrolysis of the big toe
This surgery is often part of a set of complementary corrective processes realised during one surgery. Cutting or lengthening of the joint capsule and peripheral ligaments allow a correction of the joint deformity.
This surgery combines a bunionectomy (bone abrasion) with the cutting of the adductor hallucis tendon at the base of the phalanx. Before, it was also combined with the removal of the lateral sesamoid bone. Cutting the tendon stops its aggravating effect on the valgus deviation of the toe; the transfer of this tendon on the head of the first metatarsal then contributes to correcting the metatarsus varus .
Nowadays, the procedure described above is almost no longer used. Indeed, removing the lateral sesamoid frequently resulted in the unforeseen varus deviation of the hallux , that is to say in the opposite direction. Because the toe is deviated outwards, it becomes extremely complicated to wear shoes.
Simple abrasion of the exostosis
The bunionectomy does not correct the misalignment. It involves the abrasion of the medial part of the metatarsal head (the prominent part of the bone is sawed or milled) that reduces the medial bony protrusion and makes the wearing of shoes easier. However, since the hallux has not return to its normal axis, the deformity will continue its progression.
Proximal phalangeal osteotomy of the big toe
This procedure consists of a double V-shape cut (chevron osteotomy) or the use of a rotatory burr to remove a part of the bone in the medial base, then allowing to correct the valgus deviation of the hallux . This part removed can be trapezoidal, thicker on the inner side (medial). It allows to shorten the big toe when it is necessary according to the patient’s morphotype (‘Egyptian foot’). A fixation (osteosynthesis) can be realised, either temporarily with a pin (metal rod removed after bone consolidation) or definitively with a screw or staple.
Chevron distal metatarsal osteotomy
A V-shaped cut (chevron) of the first metatarsal neck corrects the metatarsus varus . This technique can often be used during a minimally invasive-percutaneous surgery. The incision, which is only a few millimetres long, soothes pain and facilitates recovery. A fixation with a pin or staple can be necessary.
Scarf osteotomy of the first metatarsal
The term scarf comes from the vocabulary of carpentry ‘hook scarf” which is a Z-shaped cut that allows to join two pieces of wood together.
The scarf procedure is one of the most common osteotomies to treat hallux valgus . A Z-shaped cut of the first metatarsal bone is performed in the horizontal plane with an oscillating micro-saw. Its inferior and distal part is moved towards the other toes (up to 50% of its width), what corrects the varus deformity. An osteosynthesis with 2 vertical screws is often realised. This procedure is generally performed by open surgery.
Wide and flexible shoes with thick soles are recommended for the postoperative period. Then, weight-bearing walking rehabilitation is necessary depending on the pain experienced. Two to three months after surgery, resuming physical activities normally and wearing normal shoes can be considered.
Arthrodesis of the first metatarsophalangeal joint
This procedure consists of a fusion of the proximal phalanx of the great toe with the first metatarsal after removing the cartilaginous articular surfaces of these two bones. Bone fixation (osteosynthesis) with screws or screw plate is the most often required.
It is especially used for the treatment of hallux rigidus but rarely for hallux valgus .
Implant arthroplasty of the first metatarsophalangeal joint
In some cases, using a prosthesis to keep the mobility of the joint is an alternative. Several types of prostheses exist for diverse functions (resurfacing implant of the phalanx or metatarsal bone, or interposition implant).
This kind of surgical procedure is extremely rare to correct hallux valgus .
None of these procedures is exempt from risks of complications. Information about the risks incurred should be given by the surgeon.
It remains crucial to wear shoes depending on one’s morphology and to wear adapted silicone protections to prevent and relieve pain. In this way, EPITACT® offers a wide range of bunion supports to daily protect the forefoot* or to realign the big toe during the day* or at night*. Actually, surgery corrects the double deviation associated with hallux valgus , but without real change of habits, recurrence remains possible. Hallux valgus is a deformity that cannot disappear over time. To avoid it, read our article to get some practical advice that have been proven to be effective.
*These products are class I medical devices that bear the CE marking under this regulation. Carefully read the instructions before use. Manufacturer: Millet Innovation. 09/2021