INTRODUCTION

This chapter presents an overview of podiatric surgery. There are many facets to the subject and the intention is to cover most of these, providing enough information to enable the practitioner to make informed decisions regarding surgery and communicate these to patients and colleagues alike. Podiatric surgery has undergone considerable development in recent years, with the recognition that podiatric surgeons are fulfilling the role of specialists within the broader field of healthcare.

With the expansion of podiatric surgery has come the increasing responsibility for the welfare of the patients being treated. This responsibility starts from the first contact with the patient and finishes at discharge at the conclusion of a treatment programme or episode. Patient management begins at the point of referral and covers many aspects, and ends at discharge. Skill is required to allow communication with all patients, ensuring that they have the required information. This will enable them to take an active role in determining their regimen of care and to give informed consent to treatment. Therefore, it is important to understand the concepts of what is required to fulfil the role and deal responsibly with each stage.

Responsibility is an issue that can weigh heavily when dealing with the patient presenting with a difficult complication after the surgery. The patient holds the surgeon responsible for the outcome and demands a solution to any complications. Careful management of the patient is required if the patient–practitioner relationship is not to break down. Poor communication and surgical result are perhaps the quickest routes to litigation.

Miller and Boegel (1992) summarise the process of surgical principles, as shown in Table 23.1. These headings indicate the stages required in undertaking surgical practice, and at all stages good communication with the patient and colleagues is a vital aspect of surgical management. Good communication is the only way of making patients understand their problems, their management and how they are involved in the decision-making process. Being responsive to the needs of the patient also means that the surgeon needs to be able to understand what they are trying to communicate, and clarity at all stages will help to avoid any misconceptions. Many patients are better informed than previously because information is now widely available and no longer the sole preserve of medical professionals. Only by adapting practices to fit around the need for good communication at all levels will the professionals be able to deliver the type of service demanded of them.

Table 23.1 Summary of the process of surgical principles

PATIENT SELECTION FOR SURGERY

The basis of patient selection is deciding when to operate and when not by balancing risks against benefits. It is pointless undertaking complex multiple procedures on a patient who is unlikely to reap the benefits due to extreme age or infirmity or because they are wheelchair-bound. Likewise, to deprive a healthy 80-year-old a simple procedure because of age is equally wrong. It is essential to make an assessment of what the likely outcome might be and how the risks of the procedure are likely to affect the patient should they occur.

The decision-making process is multifactorial and needs to be based on the patient’s physiological, medical, psychological and podiatric status, as well as their personal circumstances.

Physiological age is an important factor in patient selection. Often a fit 70 year old may make a more suitable surgical candidate than a 50 year old with multisystem pathologies, because the 70 year old may well be physiologically ‘younger’ than the 50 year old. However, the notion of physiological age is a difficult one to quantify, and the surgeon needs to make an estimate.

A patient’s medical status needs to be considered carefully and this becomes increasingly difficult if there are several problems. A single pathology such as diabetes is something that can be assessed and quantified as a risk. However, if that diabetic also has hypertension and a history of renal problems the risk factors begin to accumulate. Where patients have multiple pathologies affecting different body systems the risk is much more difficult to quantify. Specialist opinion should be sought to clarify the decision-making process where this is complex or if there is any uncertainty.

Psychological assessment is a difficult area, and most practitioners rely on making an assessment based on their interaction with the patient during the consultation. Patients who present with a psychological history may be open and able to discuss and rationalise it. Very young and very old patients may show more overt signs of their psychological status. However, some patients appear calm and measured at consultation but develop more overt signs of psychological abnormalities when under the stress of the surgery and during the subsequent stages in follow-up treatments. These patients pose a potential management problem and may cause problems in the follow-up clinics in that they need more time and input during recovery and rehabilitation.

Podiatric status is more straightforward. This being the practitioner’s main area of expertise it should be possible to assess the risks of a particular procedure and the incidence of complications associated with it.

Personal circumstances are important. The patient’s expectations as to how they will cope with the enforced rest after surgery and how quickly they will be able to return to work and other activities need to be addressed. Patients who live alone without any support from family or friends are not good candidates for day surgery. There is a strong case for these patients to be managed as inpatients or in some sort of intermediate care facility. Self-employed manual workers often pose difficulties when they are under pressure to return to work as quickly as possible. Incorporating the requirement to be off work for a certain period into the consent form is a good way to protect the practitioner against a claim for damages related to this. People’s home environment, job, dependants and hobbies need to be included in assessing the patient’s suitability for the proposed surgery.

All these factors must be carefully considered, and the patient informed as to the surgeon’s opinion in language that they understand. With elective surgery the final decision to proceed rests with the patient. The decision not to operate lies with the surgeon.

PATIENT CONSENT

Patient consent (see also Chs 16 and 28) is an important part of the surgical management of any patient. The need to communicate what a procedure will entail and its possible outcomes is paramount in keeping the process running smoothly without ‘hidden surprises’. There is always debate as to how much a patient needs to know regarding complications, and how common a complication needs to be before it becomes mandatory for patients to know (for the purposes of informed consent) is not clear. The NHS consent forms use the phrase ‘commonly occurring or serious’ when referring to complications. The gravity of a particular complication is another consideration as to how important it is for a patient to be appropriately advised. A complication with only a minor risk, such as a stitch abscess, has much less impact than, for example, chronic regional pain syndrome (CRPS), which is likely to have a much more lasting and serious impact on the patient’s life.

The situation with regard to consent is not universal, and in different countries the law differs. The interpretation of ‘informed consent’ in the USA is quite different, and complications of a much lower risk are included in the group ‘need to know’ prior to surgery.

As a standard for podiatric surgery it would be best to advise patients regarding the risks of infection, swelling, thrombosis, loss of function/stiffness, recurrence of deformity (where appropriate), delayed healing, non-union and the potential to be worse off after surgery. These cover most eventualities, but risks specific to the procedure need also to be communicated to the patient. There are no set guidelines for this and the practitioner needs to judge how much to tell the patient and how far to go in advising of risks prior to surgery (Department of Health 2001).

The consent process also needs to prepare the patient for what they should expect from their surgical episode, beginning with their arrival at the hospital/surgery centre, to the theatre and home again. They need to have a good idea of what the normal postoperative course is for their procedure and how that might be modified according to their progress. If they are going to need to keep the foot non-weight bearing they need to be prepared and have crutch-walking training and practise prior to the day of surgery. If the surgical episode unfolds exactly as they were told, then they feel reassured.

Consent needs to be documented, and the final consent form signed by the surgeon and the patient. Consent should be supplemented with written information for the patient to take away so that they can read it thoroughly. The consent form should record what written information has been supplied to the patient for future reference in any dispute.

Consent by minors (patients under 16 years of age) must be made in conjunction with their parents or guardians. Minors can give consent in special circumstances (usually in emergency situations) but as podiatric surgery is elective surgery this question will not arise (see also Ch. 28). The use of written information is of considerable help in the process of gaining informed consent (see Ch. 27). It allows a patient, and their relatives, to digest information at leisure, away from the stresses of the hospital or clinic visit. Information giving detail of qualifications held, scope of practice, range of experience and status is also beneficial, plus it lets the patient know exactly who you are and your practice. It also removes the likelihood of a claim for misleading the patient if litigation should arise where the patient says that they believed you were an orthopaedic surgeon or other registered medical practitioner rather than a podiatrist.

In the UK, the Department of Health produces guides to advise practitioners with regard to consent ‘best practice’. These are vital documents to help you shape your practice and can be ordered from the Department of Health or downloaded from their website.

DIGITAL DEFORMITIES

Toe deformities may occur due to several factors. Some people are born with deformed toes, the overlapping fifth toe being one of the commoner congenital types of deformity. The majority of toe deformities are acquired and may be secondary to other forefoot problems such as hallux valgus, or secondary to injuries such as plantar plate rupture (Yao et al 1996), often leading to a hammered second toe. Generalised toe deformities, affecting all or most of the lesser toes, are more likely to be related to biomechanical dysfunction. Flexor stabilisation, flexor substitution and extensor substitution are possible causes in these instances (McGlamry 1992).

HALLUX VALGUS

Hallux valgus is one of the commonest problems that the podiatric surgeon meets on a regular basis. While its aetiology remains obscure, advances in surgical technique have offered patients a high level of satisfaction with surgery. However, there is still a failure rate of surgery leading to a dissatisfaction rate of about 5–10%, possibly due to the many forces operating around the first metatarsophalangeal joint. Continued research and audit will help to reduce the failure rate further.

Procedures

Simple bunionectomy

This is indicated where a large medial eminence is causing the patient’s symptoms. It does not address the metatarsus primus varus or the position on the hallux. However, with careful patient selection it can relieve ‘bump pain’ without the need for osteotomies and the subsequent bone healing. There are, however, few patients where this is adequate as the sole procedure.

Distal metaphyseal procedures

The distal metaphyseal procedures (DMOs) are perhaps the most widely used procedures for hallux valgus correction, and there are many variations (Figs 23.1 to 23.4). Straight osteotomies, such as the Wilson procedure, and angled osteotomies, such as the Austin and curved osteotomies, all have their advocates. The angled osteotomies offer more stability than the straight osteotomy. Fixation techniques also vary, and range from multiple screw fixation to K-wires. Generally, distal procedures offer a relatively rapid rate of recovery and earlier weight bearing postoperatively than do more proximal procedures, but this is also dependent on the fixation methods and postoperative regimen. One of the main criticisms of DMOs is the incidence of avascular necrosis. Reports vary as to its incidence, ranging from 50% to less than 1% (Wallace et al 1994, Wilkinson et al 1992). Much depends on how it is detected and, in the authors’ experience, the incidence of symptomatic avascular necrosis is very low.

Figure 23.1 Preoperative photograph of a patient who will undergo a distal metaphyseal/Akin procedure.

Figure 23.2 Postoperative photograph of the same patient as in Fig. 23.1.

Figure 23.3 Postoperative radiograph of a patient who has undergone a distal metaphyseal/Akin procedure.

Figure 23.4 Detail of the distal metaphyseal/Akin procedure.

Midshaft procedures

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These are a good compromise between basal and distal procedures as they are capable of better degrees of correction than distal procedures but without the need to keep patients non-weight bearing for as long as with basal procedures. The most popular mid-shaft procedure is the Scarf osteotomy (Fig. 23.5), which gives a stable osteotomy when adequately fixed and will provide early return to weight-bearing activities, similar to the distal procedures. It is a versatile procedure that enables good control of the metatarsal head position. By judicious angulation of the cuts, the metatarsal can be lengthened or shortened, plantar flexed, dorsiflexed, as well as achieving good correction of moderate to severe intermetatarsal angles. The use of two screws giving solid fixation allows patients to begin limited weight bearing 2 weeks following surgery. The Scarf procedure (Figs 23.5 to 23.7) comprises a long Z-shaped cut (Fig. 23.6). The medial eminence is resected first by cutting the metatarsal head. Using an axis guide wire helps to decide on the degree of plantar displacement required, prior to making the bone cuts. Angling the axis guide wire towards the plantar aspect of the second metatarsal head gives a good amount of plantar displacement, with lateral rotation or transposition of the first metatarsal head. The wire should enter the metatarsal head in the dorsal half to one-third. The dorsal cut in the metatarsal head is made vertically, from the axis wire dorsally. The long cut is then made along the metatarsal. This should run from a more dorsal aspect distally to a more plantar aspect proximally, and is usually to about one-third of the metatarsal thickness from the plantar aspect. The plantar arm of the cut is then made by angling the blade forward to make an angled shelf. The direction of cut is varied depending on whether the aim is to displace the distal metatarsal or to rotate it. Transposition dictates that the distal and proximal cuts should be parallel to allow for sliding over of the metatarsal head, and for rotation angling the lateral side of the cut distally allows the metatarsal to pivot and rotate. Once positioned, the osteotomy can be fixed with two screws. The length of the osteotomy lends itself to easy placement of the screws; however, the screws need to catch the plantar shelf of bone adequately, so need to be placed where the two fragments overlap maximally. Once fixed in place, the medial side of the metatarsal can be cut to remove the overhang.

Figure 23.5 Scarf procedure: intraoperative view.

Figure 23.6 Detail of the Scarf procedure, dorsal view.

Figure 23.7 Detail of the Scarf procedure, lateral view.

Basal procedures

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For severe hallux valgus deformity the procedure needs to be carried out more proximally along the metatarsal shaft or at the metatarsocuneiform joint. A closing base wedge osteotomy can be used to close a severe metatarsus primus varus. This can be performed transversely or obliquely. A long oblique osteotomy borders on being a midshaft procedure. However, this is an unstable procedure and the patient needs to be maintained in a non-weight-bearing cast for 6 weeks. Weight bearing too soon on a base wedge osteotomy may lead to a potentially disastrous elevatus deformity of the first ray, which forces the first MTPJ into dorsiflexion and leads to transfer metatarsalgia. The Lapidus procedure or metatarsocuneiform joint fusion is an alternative (Fig. 23.8). This adds a degree of rearfoot stability by stiffening the medial column and thus reducing subtalar joint pronation. The Lapidus procedure (Fig. 23.8) also requires a non-weight-bearing cast for 6 weeks. There is a 10% incidence of non-union reported for the Lapidus procedure. Failure of a metatarsocuneiform fusion to unite is a difficult problem to manage. Re-fusing the joint leads to further shortening. This can be dealt with using a bone graft, but an autogenous graft is required to minimise the risk of further non-union. This means another surgical site to harvest the graft. However, it is a procedure capable of correcting the most severe degrees of hallux valgus. The level of rehabilitation following these procedures exceeds those of the more distal procedures.

Figure 23.8 The Lapidus procedure: intraoperative view.

Hallux procedures

It is increasingly common for metatarsal correction to be accompanied by a closing wedge procedure on the proximal phalanx (Akin procedure) (Figs 23.1 and 23.2). The rationale is that the hallux needs to be straight, postoperatively, for the tendons to be exerting force in a straight line. Any residual deformity of the hallux will allow bow stringing of the extensor tendon, thus exerting a deforming force that may contribute to recurrence of the hallux valgus. The term ‘cheater Akin’ has been used to describe the use of the Akin procedure where there is no obvious deformity within the proximal phalanx preoperatively. However, if the hallux is not straight after the metatarsal position is corrected and the soft tissue releases are performed, then the Akin procedure is the best way to render the hallux straight. A straight toe is something that patients expect after undergoing bunion surgery and is a question commonly asked preoperatively. If a patient has residual deformity they are more likely to be unhappy with the appearance of their foot. This said, cosmesis is not the main priority in hallux valgus surgery; however, in the minds of many patients it is still very important, and if they believe it to be important then it is necessary to address this as well as relieving their pain. The Akin procedure is described in orthopaedic texts as being for the correction of hallux interphalangeus, an integral part of hallux valgus deformity and more often than not seen radiographically (Figs 23.3 and 23.4).

HALLUX VALGUS SYNDROME

Hallux valgus is described as being a disorder of the first ray, the components of the deformity being a metatarsus primus varus and hallux abductus or valgus. However, the deformity tends to be progressive and the effects of this spread to other structures, and eventually may affect the whole foot.

The association between hallux valgus and flat foot has been documented previously (Kalen & Brecher 1988). Exactly how the mechanisms join the two problems is not clear. It is possible that the hypermobility in the first ray leads to medial instability and subsequent collapse of the foot into a pronated position. Or it could be that the excessive pronation leads to first-ray dysfunction and subsequent hallux valgus. However, these two conditions often lead to a transfer of load to the second metatarsal. The foot pronates and the first ray elevates, leaving the second metatarsal to compensate with the consequent overloading of the second metatarsal head and a build up of hyperkeratosis over the area and capsulitis of the joint. The latter can progress to chronic fatigue in the capsule, leading to weakening of the capsule or plantar plate rupture. This is often a more acute condition and may in turn lead to elevation of the second toe and the formation of a hammer toe deformity. This is further progressed by the hallux moving laterally and exerting pressure against the second toe. The hammer toe adds to the problems that the patient is experiencing. Footwear is already difficult because of the hallux valgus, and now the hammered second toe is adding to the requirement for extra width and depth, which are not readily available in a normal shoe.

At this stage the patient may be walking on the lateral side of the foot to avoid the painful first and second rays. This is turn leads to pain on the lateral side of the foot and often to associated strain within the leg muscles. The midtarsus joint complex may also be starting to show early signs of degeneration due to the changes taking place in the forefoot and the overpronation in the rearfoot.

All these problems add up to a foot that is chronically painful and difficult to accommodate in a shoe. For the podiatric surgeon the question is where to start and how best to manage this type of foot.

Control of the pronation with orthoses may give some relief, although it is rare to find a patient that can accommodate orthoses in their shoes as they are already having great difficulty obtaining a shoe.

Correction of the hallux valgus surgically is often a good starting point, accompanied by correction of the hammer toe and also possibly a metatarsal osteotomy to relieve the transfer metatarsalgia.

There is also a dilemma with hallux valgus syndrome that can pose a difficult surgical choice. Should the patient, who has all the signs of but a pain-free hallux valgus/bunion, be offered the hallux valgus correction or should one simply deal with the painful areas and advise the patient that this may compromise the result? Surgery on a non-symptomatic problem may be seen as controversial, and would be harder to defend if a complication ended in litigation. However, as these problems are intertwined, a good case can be made for hallux valgus correction in conjunction with surgery to address second toe deformity and transfer metatarsalgia.

A recent unpublished departmental audit (M. Graham, 2002) indicated that the results from second-toe corrections, both arthroplasty and arthrodesis, were compromised when there was concurrent hallux valgus that was not addressed.

CASE STUDY 23.1 REVISION SURGERY IN THE MANAGEMENT OF HALLUX VALGUS

This patient was referred for a second opinion, having previously undergone surgery for a painful bunion deformity and metatarsalgia. She had presented originally complaining of pain in the ball of her foot, at the base of the second toe. She also had a painful bunion that was severely restricting her choice of footwear and had been advised that correcting her bunion and dealing with the metatarsalgia by correcting her hammered second toe would cure the problem. Following the surgery she continued to have a painful bunion as well as the metatarsalgia.

The postoperative radiographs from the first procedure showed that she had undergone a simple bunionectomy, but the amount of bone resected from the medial aspect of the metatarsal was excessive (Fig. 1). She had also had an excisional arthroplasty to the proximal interphalangeal (PIP) joint of the second toe. This had left her with a distorted proximal phalanx and the hallux valgus deformity was still exerting a lateral deformity force onto the second toe. Her metatarsalgia was unchanged.

Figure 1 Radiograph showing the Silver bunionectomy.

From the radiograph it was clear that she had significant hallux valgus deformity. She had an intermetatarsal angle of 18°, which would suggest that she might be a good candidate for a Scarf procedure. However, as she had already lost a reasonable section of her metatarsal head it was considered that this would be likely to compromise any further surgery around the metatarsal head. The patient’s proximal phalanx showed angulation, with the medial side longer than the lateral side, and the second metatarsal was longer than adjacent metatarsals. However, her metatarsalgia was probably made worse as a consequence of her poor first-ray function.

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The patient’s second metatarsal head was tender and prominent on the plantar surface, with a degree of hyperkeratosis. Her second toe was deviated laterally at the level of the PIP joint surface and her hallux valgus was evident and the wounds had healed well. On weight-bearing examination her forefoot splayed and the foot was tending to overpronate.

Initially she was given an insole to redistribute weight to unload the second metatarsal head. An intra-articular steroid injection was also used to settle the inflammation in the second metatarsophalangeal joint. Unfortunately, neither of these actions brought much improvement and, after talking through the options with the patient, she considered that her symptoms were severe enough to go through additional surgery.

A Lapidus procedure for her hallux valgus was decided on, with an Akin procedure for the proximal phalanx. The excisional arthroplasty was re-done, to square off the end of the proximal phalanx, and a stabilising K-wire was used to hold the second toe while it was healing and to attempt to control overshortening. A Weil-type osteotomy was also carried out to address the metatarsalgia.

The surgery was carried out as a day case using a popliteal nerve block with an ankle tourniquet. The postoperative radiographs (Figs 2 and 3) showed the correction at 4 weeks, taken through a fibreglass cast. The views were not directly comparable to the initial radiographs as they were non-weight-bearing views; however, it could be seen that good correction of the hallux valgus deformity had been achieved, with the sesamoids being returned to a good anatomical position. On the postoperative views, the degree of previous resection of the medial first metatarsal is apparent, bearing in mind no further bone was removed from the metatarsal head.

Figure 2 Postoperative radiograph.

Figure 3 Postoperative radiograph.

The postoperative regimen was that she was kept non-weight bearing in a cast for 6 weeks. The cast was changed at her first visit at 2 weeks. At 6 weeks the cast was removed along with the percutaneous K-wire in the second toe. She was then allowed protected weight bearing in a removable Aircast boot and was encouraged to do daily range-of-motion exercises to mobilise her first metatarsophalangeal joint and to help resolve her postoperative swelling. At 3 months following surgery she had a course of low-level laser therapy to help the swelling resolve.

She did well after surgery, returning to normal footwear and activities by about 5 months, and she was discharged from the podiatric service 18 months following the surgery. However, she did return 3 years after the surgery complaining of a degree of metatarsalgia under her third metatarsal head. This has responded reasonably well to conservative treatment, and she was pleased with this result. She also had some prominence of her internal fixation, so an operation was performed to remove it.

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This case history highlights the need to make a thorough assessment of the patient’s complaint. The choice of surgery needs to address the symptoms as well as having to deal with the degree of deformity present. The initial choice of surgery was never going to correct the severity of the hallux valgus deformity present, and also the metatarsalgia was not managed. Had the decision been made to correct the hallux valgus with a realigning procedure, it is possible that the metatarsalgia may have resolved by placing the first metatarsal into a better functional position.

CASE STUDY 23.2 MANAGEMENT OF SYNDACTYLE

A young lady presented with a congenital syndactylisation between her second and third toes. This was a problem for her psychologically rather than physically. She would never take her shoes off in public places as she found it too embarrassing. On two preoperative consultations she was advised against having surgery as there was a real potential for making the situation worse. I counselled her regarding the risks of skin-flap necrosis and failure of a skin graft to ‘take’. However, she considered it would be worth the risk as the condition caused her much bother.

The desyndactylisaton procedure was carried out using a free skin graft taken from the lateral aspect of her ankle (Weinstock 1989). The incision was made around the syndactylisation to the base of the toes. From this incision, a paper template was made then opened out and the incision marked in the skin folds on the lateral side of her ankle. The midpoint of the incision was also marked to make identification easier once the graft was removed. The skin flap was then taken at full thickness. The graft was then sutured into place, using simple interrupted sutures. These were selected as they give the easiest way of adjusting the position and tension on the graft. After this was sutured, the ankle wound was closed. The toes were dressed using a saline-soaked gauze placed between the toes with a standard postoperative dressing placed over the top. Healing progressed uneventfully and the wounds settled down well. A small section of the plantar aspect healed over the skin flap. However, as this did not show too much the patient was not too concerned (Fig. 1). She was very pleased with the outcome of this and was happy to proceed with similar surgery to her other foot.

Figure 1 Postoperative view after desyndactlylisation.

The subject of cosmetic foot surgery raises a wide range of opinions, and some surgeons will not carry out any form of cosmetic foot surgery. At what point does surgery become cosmetic? When the problem affects the patient psychologically so that it restricts their activity? If someone has a deformity that prevents them from wearing a normal shoe, but is otherwise pain free, does this offer grounds for them to undergo surgery? This is a controversial area and one where a patient’s needs must be assessed on an individual basis and a suitable care programme agreed. It should be borne in mind that a patient’s expectations of the outcomes of cosmetic surgery may well be higher than when the surgery is for correction of function or the relief of pain.

MORTON’S NEUROMA

This is a common problem presenting with pain in the forefoot, usually described as burning and intermittent in nature (see also Ch. 4). Patients often describe the need to remove their shoe when the pain occurs. The pain often radiates into the toes, and the classic site for this is the third and fourth toes; usually, patients will have been suffering with the problem for some months before seeking advice. In most instances this is due to the fact that there is little to see and the fact that the pain is of an intermittent nature.

Treatment comprises insole therapy, steroid injections or surgical excision. The choice with regard to excision is with regard to where to place the incision. A dorsal approach avoids the problem of plantar scarring, while a plantar incision is more direct and places the incision directly over the nerve, allowing better exposure and an easier procedure. The plantar incision requires that the foot remain non-weight bearing for 3 weeks to allow healing to progress and to avoid problems with the scar. Either way the enlarged section of nerve is resected back to where it is a normal size and preferably far enough back in the foot to be off the main weight-bearing area. This helps to avoid the problem of recurrence or stump neuroma formation.

LESSER METATARSAL OSTEOTOMIES

Lesser metatarsalgia is a problem that in many instances responds well to conservative treatment; however, when conservative treatment fails there are surgical options. A long metatarsal can be shortened or a plantar flexed, and a displaced metatarsal can be elevated. Radiographs can guide the surgeon to identify these situations; however, there are instances where the radiographs appear normal but the foot is painful and the clinical signs point to mechanical overloading. The presence of corns and callus as well as pain in the MTPJ all suggest mechanical causes. In these instances computerised pressure-measurement systems can be employed to confirm that the affected metatarsal is indeed overloaded (see Ch. 15). Other skin pathologies, such as verrucae over the metatarsal heads, can be ruled out, but this may be particularly difficult when patients have had a long history of treatment for suspected verrucae. If in doubt, a punch biopsy may be performed.

Many metatarsal osteotomies have been described over the years; however, the Weil osteotomy, and variations on this, have overcome many of the pitfalls of previous techniques, allowing for accurate control of the metatarsal position, with good internal fixation and a low incidence of non-union.

The proximal displacement osteotomy, or Weil-type osteotomy, is a valuable technique for the treatment of metatarsalgia. The metatarsal is cut just at the margin of the dorsal joint surface, with the saw as parallel to the weight-bearing surface as possible. Once the cut has been made the metatarsal head can be displaced proximally, so shortening the metatarsal. The osteotomy has a relatively large area for healing, and weight bearing tends to push the opposing bony surfaces together, allowing early weight bearing. The osteotomy can be fixed with K-wires or screws to hold it in position. One of the problems associated with the Weil-type osteotomy is a floating toe. This may occur due to scar contracture or the altered biomechanics of the joint or a combination of both. The fact that the osteotomy is never completely parallel to the weight-bearing surface means that the proximal displacement does tend to lower the metatarsal head slightly as it is displaced proximally. This has the effect of weakening the lumbrical function and so produces loss of lumbrical function on the proximal phalanx. Making a second cut into the metatarsal, to remove a thin section of the metatarsal allows the metatarsal head to elevate – countering the plantar displacement, and thus producing a good toe position and allowing it to function postoperatively.

Where a purely dorsiflexory procedure is required, in the case of a plantar-flexed metatarsal, a Schwartz osteotomy can be used. This is a dorsal, oblique closing-wedge osteotomy, leaving the plantar hinge intact. This gives a stable osteotomy with an additional point of fixation.

All metatarsal osteotomies carry the risk of either under- or overcorrection, and unfortunately there is no precise way of determining the degree of correction required preoperatively. How well the pressure is redistributed will not be known until the patient is walking again. Undercorrection may not resolve the metatarsalgia, and overcorrection will result in transferring the load to an adjacent metatarsal. Because of these factors, the patient must be advised of the risks prior to undergoing surgery.

The possibility of plantar plate rupture also needs to be taken into account. Where present, the surgeon needs to decide whether repair of this is required in isolation or in conjunction with structural realignment (Powless & Elze 2001).

HALLUX RIGIDUS

This is a condition that ranges from the early stages of slight loss of motion at the MTPJ (hallux limitus) to a completely rigid joint. Pain is related to activity and the encroachment of footwear on the dorsal enlargement of the joint. A long metatarsal or a dorsiflexed metatarsal are thought to be aetiological factors in the development of hallux rigidus (see also Ch. 4).

Surgical treatment in the early stages is a choice between a simple cheilectomy, where the dorsal osteophytic lipping is resected, through to a metatarsal decompression osteotomy or a proximal phalangeal osteotomy. All these are carried out in conjunction with ensuring that the sesamoids are mobilised, as these will certainly contribute to loss of motion at the joint if they have become fixed to the metatarsal head. Metatarsal osteotomies have fallen from favour due to the risk of transfer metatarsalgia. Proximal phalangeal osteotomies, such as the Bonney Kessel procedure, redirect the motion at the joint into a more dorsal direction.

Once the joint range of motion has deteriorated, in conjunction with reduction of the joint space, then joint-destructive procedures are the only way to resolve the painful joint. The choices are an arthrodesis, a joint-replacement implant or a Keller procedure. The choice is determined based on the patient’s age and activity levels. In a patient under the age of 60 years, a Silastic joint replacement or Keller arthroplasty are rarely advisable as primary procedures. The risks of Silastic joint failure and problems associated with a dysfunctional hallux, in the case of the Keller procedure, make them more suitable for older patients or in a salvage situation. An arthrodesis is a tried and tested approach in patients under 60 years of age. However, the restriction this places on the wearing of heeled shoes makes this a less than ideal solution for women. Joint replacements other than Silastic joints may be an option. However, metal and ceramic joints have still to be shown to be efficacious over a long period of time.

SESAMOID PROBLEMS

Sesamoid pathology is another cause of pain around the first MTPJ. An enlarged sesamoid may well give rise to a localised hyperkeratotic lesion. The sesamoid may be enlarged secondary to being bipartite or tripartite, or as a result of trauma or degenerative changes. The medial sesamoid is the most commonly affected.

Another factor to consider is how the sesamoid position alters with the progression of a hallux valgus deformity. As the first metatarsal moves into varus and the toe into valgus, the sesamoids move laterally in relation to the metatarsal head. The lateral sesamoid is able to move into the intermetatarsal space and move into a more dorsal position, thus becoming less weight bearing. The medial sesamoid tends to become more prominent on the plantar surface as it rides over the intersesamoidal ridge.

Evaluation of the sesamoid position can be made radiographically, from an anteroposterior view and an axial or sesamoid view. The options for surgical treatment of sesamoid problems are to remove a part, or the whole, of the sesamoid, or to reposition it into a better anatomical position. This latter option would be chosen where the sesamoid symptoms are part of a wider hallux valgus symptom complex (Fig. 23.9).

Figure 23.9 Sesamoidectomy: intraoperative view.

Partial removal of a sesamoid, or a sesamoid planing procedure, involves taking off approximately one-third to one-half of the sesamoid, cutting the plantar aspect off the sesamoid in a plane parallel to the weight-bearing surface. Removing too much increases the risk of the remaining bone of the sesamoid fracturing. Total sesamoidectomy is a straightforward procedure, but it is possible that removing the sesamoid may add to instability of the medial ligaments of the first MTPJ, leading to an increased risk of hallux valgus progression. Tight suturing of the capsular incision may go some way to preventing this.

SKIN PLASTIES

The use of skin plasties is widespread in podiatric surgery. In their simplest form, a lenticular incision over a mallet-toe correction aids in correcting the deformity by removing redundant skin. As well as removing redundant skin, the skin plasty is useful in lengthening the skin. An overlapping fifth toe is a situation where lengthening the skin aids correction of the toe position, usually in conjunction with an extensor tendon lengthening procedure. Two common techniques for this are the V-to-Y skin plasty and the Z skin plasty (Fig. 23.10). Rotational skin flaps can also be used to help close defects after skin-lesion excision. There are several variations on these approaches.

Figure 23.10 Skin plasties.

REARFOOT SURGERY

The scope of rearfoot surgery undertaken by podiatric surgeons in the UK has increased in recent years. Rearfoot surgery is always going to be in less demand than the forefoot procedures that make up the majority of podiatric procedures. However, the realm of flat-foot reconstruction, tibialis posterior dysfunction repair and rearfoot fusions is an expanding one (McGlamry 1992).

SUTURE MATERIALS

These can be divided into absorbable and non-absorbable, and monofilament or braided. Monofilaments are smooth, single-stranded sutures, which slide through the tissues easily and provoke less tissue reaction. The disadvantages are that knots are less secure and they tend to be springier as the suture tends to have a degree of ‘memory’. Braided sutures are woven fibres and are good for tying knots as they grip well; they are more flexible but may produce more tissue reaction.

Absorbable sutures will break down in contact with body fluids and enzymes and normally are about 30% weaker after 14 days. However, they take 90–120 days to absorb fully. A small percentage of patients will have some suture reaction, especially when absorbable sutures are used to close skin. This manifests itself as a small pustule, often with suture material expressed from it when debrided.

Non-absorbable sutures will maintain strength for much longer. However, they do need to be removed and this is often uncomfortable for the patient. Sutures are usually removed at about 10–14 days postoperatively or after 3 weeks with incisions on the plantar aspect of the foot.

Sutures come in a range of sizes and these are expressed in 0 grades. Most podiatric procedures utilise sutures in the range 2-0 (thick) to 5-0 (thin). Obviously, the thicker the suture the stronger it is. Thinner sutures produce less tissue reaction and a finer scar; however, a balance needs to be struck between the two and so a compromise is made.

The other choice to be made when selecting a suture for any given application is the needle design. The needle can be straight or curved and the point can be ground in one of several ways. Curved needles are used most commonly in foot surgery (Fig. 23.11). This is usually expressed as part of a circle, e.g. a 2/3 round needle is two-thirds of the circumference of a circle. A cutting needle is commonly used for skin suturing and in podiatric procedures. The cutting needle is ground into a triangular shape so that there are three separate sharpened edges to help the needle pass through tough tissues. The cutting needle has one of the apices of the triangular shape running around the inside circumference of the needle. This can more easily cut through the tissue and enlarge the needle hole, as the needle is pushed into the tissue. Therefore, a reverse cutting needle is to be preferred, as the apex of the triangle runs around the outside circumference and so the needle is less inclined to cut though to the edge of the wound.

Figure 23.11 Types of suture technique and suture needles.

The choice of sutures for different procedures is mainly dependent on preference, but within a range of possibilities. The strength of the suture combined with the type of needle needs to be matched to the purpose for which they are going to be used.

SUTURE TECHNIQUES

Sutures are used to appose structures. How best to achieve this depends on choosing an appropriate suture material and then selecting a technique for inserting it into position (Fig. 23.11).

TISSUE HANDLING

The surgeon should always be aware of the damage that any given procedure is causing to the healthy cells within the foot. Every time an instrument grabs a piece of tissue, retracts a tendon or makes a cut, cells are being damaged. Just because this is at a cellular level and not readily visible at the time of surgery does not mean that it does not happen. The amount of swelling and inflammation postoperatively will always be greater if a procedure is carried out roughly. Thinking physiologically, at a cellular level, will help the surgeon to visualise what is going on and appreciate how every interaction made will affect the foot. The surgeon must respect tissue and be gentle, taking care not to overstress the wound edges and the structures being retracted.

Making incisions the right size for the procedure is important – too small, and the wound needs to be stretched too much to gain access; too large, and unnecessary tissue damage occurs. Excessive undermining of the skin and dissection of the layers is likewise best avoided. The more that the inflammatory process is initiated by surgery, the more swelling will occur, placing pressure on the wound, and with it subsequent fibrosis that will bind the tissue layers together.

‘Atraumatic technique’ is the term used to describe careful surgical technique, and no more damage should be caused than is necessary. The concept is wide reaching in its philosophy and encompasses everything that the surgeon will do during the procedure.

Attention to positioning the foot will allow for exposure without pulling on the tissues. Incision planning is also important, and time spent accurately locating the anatomical landmarks and drawing the incision preoperatively is valuable, ensuring that the incision is located correctly. Time should be taken to do this, rather than wasting time once the clock is ticking with the tourniquet in place. A detailed knowledge of the anatomy is needed to be able to place the incision so as to locate the structures that are the focus of the procedure while avoiding structures that need to be preserved.

In summary, attention to detail and an appreciation of what is being done to the patient at a cellular level make for a better understanding of the whole process of surgery. Good tissue handling is rewarded by better outcomes from surgery and patients suffer less pain, less swelling and gain better function.

POSTOPERATIVE DRESSINGS

The postoperative dressing (see also Ch. 10) has the following roles:

These objectives can be met using a combination of layers: the inner (contact), middle, outer and surface layers.

POSTOPERATIVE COMPLICATIONS

Complications are a fact of life; therefore, it needs to be accepted that they occur and the surgeon needs to learn how to deal with them and how to learn from them. Trying to understand complications and why they occur can help to further refine techniques to reduce their incidence to a minimum.

Infection

This is a complication that affects any type of surgery (Figs 23.12 and 23.13). The incidence of infection in podiatric surgery is quoted at anything from 10% to less than 1%. Many factors affect infection rates, and good technique helps to reduce the risk. Good tissue handling and copious wound lavage prior to closure helps to minimise infection. The environment is also very important. Where operating theatres are used by other specialities, the rates of infection are often higher than when sole-purpose facilities are used. A high number of air changes per hour also helps to reduce the airborne transmission of bacteria to a low level. Other factors include the number of operating personnel in the theatre, as well as the length of the procedure (the longer the wound is open the greater the risk of infection).

Figure 23.12 Postoperative infections.

Figure 23.13 Postoperative infections.

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Aspects of the patient’s health may render them at a higher risk of infection. Poorly controlled diabetes, obesity, anaemia and treatment with immunosuppressive drugs such as steroids all need to be considered.

Infection usually becomes apparent from about 5 days postoperatively onwards, the commonest symptom of which is pain. Increased localised swelling, redness and heat are then followed by proximal spreading of the signs, with lymph-gland enlargement posterior to the knee and in the groin. Pyrexia may also develop. Discharge may be evident, striking through the dressing, and this may be malodorous.

Examination of the wound will show an acute inflammatory process, with redness and swelling beyond that which would be expected with normal wound inflammation. The wound may well be dehiscing and discharging. The discharge may be a yellow tissue fluid or pus.

Management of infection should encompass appropriate antibiosis, lavage of the wound to remove debris and pus and debridement of necrotic tissue. Frequent dressing changes are required, along with close monitoring to check for deterioration of or improvement in the infection. Microbiological analysis of a wound swab will be essential for culture of the infecting organism, with a sensitivity test to choose an appropriate antibiotic. However, immediate broad-spectrum antimicrobial therapy should be started prior to the swab result being received, and the therapy then altered as required in the light of the results.

Localised wound infection may not need a wound swab. A 5-day course of a broad-spectrum antibiotic such as amoxicillin may be all that is required.

Blood tests to measure the white blood cell count are useful to monitor infection and aid diagnosis. The white blood cell count is raised in infection, although that is not the sole reason why it might be elevated. Blood culture can also be used to detect bacteria.

The surgeon must be alert to the possibility of infection extending to bone; some infections that may be extending to bone or are otherwise severe in nature will need urgent treatment with intravenous antibiotics.

Confirmed osteomyelitis will need treatment with appropriate antibiotics for a prolonged period. Traditionally, intravenous antibiotics have been used. However, some of the newer drugs are efficacious orally. Debridement of the infected bone is usually required. In these circumstances the debrided area may need further reconstruction in the future. This should be delayed for at least 6 months after the infection has cleared to reduce the risk of reinfection and allow optimum healing.

Avascular necrosis

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Avascular necrosis is the death of bone following vascular compromise (Fig. 23.14). This is a particular problem with osteotomies. Many articles have been published on the incidence of avascular necrosis following distal metaphyseal osteotomies. The incidence seems to vary widely and much seems to depend on the sensitivity of the investigating technique. Clinically, the incidence is very low, but the use of sophisticated techniques, such as MRI, shows the incidence of avascular necrosis to be much more common. However, if the avascular necrosis is subclinical, one might question its relevance to the outcome of the procedure (Wilkinson et al 1992). Where it does occur, it can be devastating to the outcome of the procedure, with collapse of the metatarsal head. Avascular necrosis may appear several months after the procedure, and the early radiographic signs are minimal or totally absent. An increase in bone density may then occur as the bone starts to collapse inwards and distortion follows. Once detected, keeping the foot non-weight bearing will help to reduce the forces on the weakened area until such time as revascularisation occurs. Physical therapies may help to speed this along.

Figure 23.14 Radiograph showing avascular necrosis in the head of the first metatarsal. There is also a stress fracture in the second metatarsal shaft.