New hallux valgus techniques mean effective day surgery and 95 per cent patient satisfaction, says Dr Jason Hargrave
Hallux valgus, or bunion deformity of the first metatarsal-phalangeal joint, has previously produced varied outcomes from surgical treatment.
This has undoubtedly given surgical treatment a bad name, with many GPs still being left in the dark as to whether or not referral for correction is appropriate for their patients.
This is hardly surprising – the development of more than 130 different surgical techniques surely reflects dissatisfaction among specialists too.
Hallux valgus deformity itself is not correctable by conservative measures, although occasionally patients may gain short-term pain relief from corticosteroid injections or orthoses. Caution is advisable: in one large study, juvenile hallux valgus was made worse by the use of orthoses.
The good news, however, for sufferers of this often painful, unsightly and dominant hereditary deformity is that new techniques developed by podiatric surgeons in the US and UK are yielding consistently good results with few complications.
Is day surgery a safe option?
In the UK there are now more than 50 NHS podiatric departments, in which hallux valgus surgery is one of the most common conditions treated. Podiatric surgeons in the UK have pioneered effective local anaesthetic techniques, usually performed at the level of the ankle or knee (popliteal blocks). These give excellent post-operative pain control, allowing patients to take oral analgesics immediately post-op and permitting return home on the same day.
This has greatly expanded the scope of foot and ankle cases, which traditionally meant patients remained in hospital; these are now undertaken safely as day-cases. Across two podiatric departments in two major London teaching hospitals over an eight-year period, fewer than 10 cases were re-admitted for in-stay, proving that patient safety is not compromised with day surgery. The less time a patient remains in hospital the less chance there is of exposure to pathogens such as MRSA.
Audit figures produced from an ongoing national multi-centred study reveal 95 per cent of patients are satisfied with their pain control following podiatric surgery. This, coupled with out-of-hours on-call provided by most podiatric teams, means there is no great burden placed on GPs when patients are discharged after day-case procedures.
The advent of new osteotomies utilising low-profile titanium screws produces very stable bone fixation allowing for early post-op ambulation; this in itself reduces the complication rate. Previously reported post-operative DVT rates for lower limb surgery of 30-70 per cent have been reduced to less than 0.5 per cent with podiatric techniques and tailored post-op regimens.
Where more traditional techniques have caused over-shortening of the first metatarsal – leading to painful overloading of the central metatarsal-phalangeal joints, prolonged periods in non-weight-bearing casts with muscle wasting and stiff joints – new techniques have overcome these difficulties. Previous evidence-based studies of 'traditional' hallux valgus techniques were never able to raise the patient satisfaction rates much above 70 per cent.
Rotation scarf osteotomy
The scarf, or z-osteotomy of the first metatarsal, was first reported as an effective technique for the correction of mild-moderate hallux valgus deformity in 1989. But this excellent and stable osteotomy still left the problem of having to deal with large deformities with significant splaying between the first and second metatarsals. This meant that unstable base osteotomies, or fusion of the fusion metatarsal-cuneiform joint, were the only effective solution, ruling out elderly patients, patients with osteoporosis or other significant organic disease.
In recent years a consultant podiatric surgeon and his team at Ilkeston Hospital, Nottinghamshire, took the scarf osteotomy and modified it by rotating the first metatarsal fragments, as opposed to pure transverse displacement. The modification, subsequently used on more than 900 of his
patients, has meant severe deformities can now be treated effectively.
In a recent prospective study of the first 35 patients who underwent the new rotation scarf osteotomy, at two years post-op all patients were pain-free, no revisions were necessary and no serious complications were encountered; 92 per cent of the group were totally satisfied without reservation, although two cases had mild recurrence but remained pain-free.
With the scarf osteotomy the bone cuts will ensure the bone fragments are pushed together by weight-bearing forces, rather than being distracted apart. Even with severe deformity and moderate osteoporosis, the large surface area of bone-bone contact encourages good primary bone
healing and the structural integrity of the cuts
held by screw fixation allows for the commencement of full weight-bearing after two or three days of relative rest.
As mentioned previously, this greatly reduces the risk of vascular complications, without compromising the surgical outcome. Patients in relatively sedentary occupations can often return to work at four weeks post-op, reducing the need for extended periods off work in below-knee casts, previously required for other hallux valgus techniques.
The adaptability of the technique has also proven a bonus by allowing its biomechanical application. Thus not just the transverse plane correction but also shortening, lengthening, elevating or plantar-flexing of the metatarsal can be adjusted to address the pathomechanical dysfunction often seen in hallux valgus deformity.
As with all surgeries, the scarf has had its critics, mainly from non-podiatric specialists. Initially varied outcomes and technically demanding, the scarf's success will be governed by the training, experience and skill of the operating surgeon. In the hands of the author, this procedure can be undertaken from start to finish in under 20 minutes, although on average the procedure will take around 35 minutes.
This is felt to be a further bonus as studies have proven that post-operative infections mainly occur at the time of operation so that reduction in operating time will reduce exposure to pathogens.
Contemporary podiatric specialists regard GP surgeries as an important and amiable supporter of the ever-increasing number of podiatric departments.
Hopefully, as the success of modern-day treatment for hallux valgus and other foot deformities becomes apparent the poor reputation associated with foot surgeries will be dissolved.
Assessment for surgical intervention
When assessing hallux valgus deformity one needs to look at several clinical and radiographic parameters. These include length of the metatarsal, the splay or intermetatarsal angle between the first and second metatarsals including the amount of sesamoid displacement, the degree of lateral
drift of the hallux, the sagittal plane position of the first metatarsal and the degree of degenerative joint disease in the first MTP joint.
Some well-established osteotomies, such as the chevron (distal metatarsal) osteotomy, are proven to give excellent results when correcting mild-moderate deformity. When pain and instability occurs at the first metatarsal-cuneiform joint, the modified Lapidus (MCJ1 fusion) still enjoys great success when the patient is carefully selected, but should not be used on more elderly patients due to the prolonged post-op recovery requiring six-eight weeks non-weight bearing. In the elderly patient group, osteoporosis is much more prevalent, making bone fixation techniques less stable and increasing the chances of intra-operative complications and fixation migration in the post-op period.
As hallux valgus is by its nature a progressive condition, the prognosis for good correction will reduce with the severity of the deformity and the age of the patient. It is also worth
noting that increasing lateral drift of the hallux often causes lesser toe problems, such as hammertoe deformity. Coupled with secondary degenerative (osteoarthritic) disease produced by the subluxation of the joint, the case is
made for early surgical intervention, where results are better with fewer complications.
Jason Hargrave is consultant podiatric surgeon at Charing Cross Hospital, London