Plantar fasciitis is the commonest cause of heel pain. We see about 50 new patients per year in a population of 260,000 or 193/million/year. However, this is only the tip of the iceberg as many people probably never consult a practitioner about this condition, or are treated by a GP, podiatrist, rheumatologist or sports medicine practitioner.
Anatomy and pathology
The plantar fascia is the principal soft tissue support of the longitudinal arch (Kitaoka 1992). Degenerative changes are present in the plantar fascia of asymptomatic older people (Tountas and Fornasier 1996). Similar but more severe changes are seen in resected specimens at heel surgery (but as patients who come to surgery represent the most resistant group their histology may not be representative of the plantar fascitis population as a whole). Clinically apparent rupture is rare, but ultrasound and MR studies suggest partial tears may be reasonably common. Rupture may be precipitated by steroid injection. Ankle dorsiflexion is usually limited and calf power is reduced (Kibler et al 1991, Riddle et al 2003)
Baxter has emphasised compression of the nerve to quadratus plantae as a source of plantar heel pain. Rose et al (2003) found abnormalities of sensory testing in the medial calcaneal nerve distribution of three-quarters of patients with heel pain; half also had abnormalities in the medial plantar nerve distribution.
Labib et al (2002) described the “heel pain triad” of plantar fasciitis, posterior tibial tendonopathy and tarsal tunnel syndrome. They viewed it as a combined failure of the static (plantar fascia) and dynamic (tibialis posterior) supports of the arch.
Epidemiology
Most series looking at a general population have a mean age in the late 50s. The mean age in series concentrating on athletes is about 10 years younger. The condition is rarely seen under the age of 20 or in extreme old age. Male:female ratio is about 1:2. It is commoner in the obese, in those standing for prolonged periods at work and working on a hard surface (Gill et al 1996, Riddle 2003).
Plantar fasciitis is often said to be commoner in overpronators, but most studies which have looked have found a large majority have neutral feet. As the incidence of overpronation in the general population is unknown this is impossible to interpret. Even in athletes Kibler et al (1991) found only 10/43 with overpronation. However Prichasuk (1994) found mean calcaneal pitch to be significantly lower (16º versus 20.5º) in patients with symptomatic heel pain than in normal feet, and Huang et al (2004) found ultrasonographic changes in 43% of people with flatfoot but 9% in those with normal arches. All of these studies have potential for selection bias.
Riddle et al (2004) found that plantar fasciitis mainly affected work, hobbies and running rather than non-weightbearing and light physical activities. Obesity was the main predictor of the degree of disability.
Clinical features
The characteristic complaint is of pain under the medial aspect of the heel, typically worst on the first step in the morning, improving as the day goes on then often getting more painful towards evening. Some patients have more weightbearing pain than first step pain. The pain may radiate across the heel or down the plantar fascia.
Tingling, electric shocks, altered sensation and rest pain should suggest nerve entrapment - tarsal tunnel syndrome, nerve to quadratus plantae, medial calcaneal nerves.
All patients should be asked about symptoms suggestive of a spondyloarthropathy such as ankylosing spondylitis: other inflamed joints or tendon attachments, inflammatory back pain, iritis, blood or mucus per rectum, urethritis, skin problems especially psoriasis.
A history of trauma or recent increase in physical activity should suggest acute or stress fracture of the calcaneum.
Many patients have had the problem for a long time - over a year is not unusual - and may have had a variety of treatments. However, it is rare to see a patient who has had plantar fascitis for over 3 years at presentation - whether the conditions resolves or patients adjust to it is unknown. Patients have often had their symptoms explained to them in terms of a "spur" and may assume that they just need the spur removed and all will be well.
Typical physical findings are localised tenderness under the medial calcaneal tubercle and sometimes in the proximal plantar fascia, sometimes worse on toe dorsiflexion (the windlass test). There is usually reduced ankle dorsiflexion due to a tight Achilles tendon - this may only be relatively reduce compared with the other side. The patient is often obese.
The patient's hindfoot position and general foot shape and mobility should be noted.
Generalised heel tenderness is not typical of plantar fascitis and should usually exclude the diagnosis - the usual causes of this are plantar fat pad atrophy, previous calcaneal fracture and nonspecific pain.
Patients with Achilles tendon pathology may be referred as "heel pain" but the different site of pain and tenderness is usually obvious. Achilles tendonopathy and plantar fascitis coexist more often than would be expected by chance (Gibbon and Long 1999).Tenderness, hypersensitivity and a positive Tinel test should be sought over the tarsal tunnel, the nerve to quadratus plantae and the medial calcaneal nerves. Tenderness over the calcaneum itself may indicate a stress fracture. The ankle and subtalar joints should be examined - occasionally referred pain from an arthritic joint is felt under the heel. The tibialis posterior tendon should be examined. The local skin should also be searched for evidence of penetrating trauma.
Investigations
The diagnosis of plantar fascitis is usually a clinical one and investigations contribute little. They are of most use in elucidating a suspected inflammatory arthropathy or stress fracture.
Blood investigations
If an inflammatory condition is suspected a full blood count, ESR, CRP, rheumatoid screen, antibody screen and HLA serotype may be helpful. We have found these tend to be non-specific and an isotope bone scan is often more helpful. There are no publications on the value of these or other blood tests in plantar fascitis.
Imaging
A standing lateral hindfoot view will show calcaneal pathology including stress fractures, erosions at the plantar fascial attachments, subtalar arthritis and calcaneal spurs. An oblique view has been suggested to show stress fractures and erosive changes. An isotope bone scan may show increased uptake at the medial calcaneal tubercle: the sensitivity is about 60% and specificity 100% (Williams et al 1987, Ozdemir 2002). Both ultrasound and MR scanning show plantar fascia thickening, perifascial oedema and areas of disruption. (Gibbon and Long 1999, Yu 2000, Kane 2001).
Plantar calcaneal spurs are seen in 60-90% of patients with plantar fascitis and 10-30% of the normal population. Therefore, as there are many more people without plantar fascitis than with, the vast majority of spurs are asymptomatic. Contrary to common belief, the "spur" is actually a shelf of bone seen end on and lies in the attachment of flexor digitorum brevis rather than the plantar fascia. As spurs may be asymptomatic and removal of the spur seems no better than plantar fascial release alone in surgically treated patients, the spur should probably be seen as a marker of plantar fascitis but not the cause of symptoms.
Few studies of imaging consider the impact of the results of imaging investigations on the diagnostic process, treatment plan or prognosis. Williams et al found that 55% of patients with plantar fascitis and increased uptake on isotope scanning had persistent symptoms requiring injection compared to 28% of those without increased uptake. However, those with increased uptake were more likely to respond to injection than those without increase (76% versus 16%). Their diagnostic criteria and treatment protocol may not have been standardised so it is difficult to draw conclusions. In any case, it is unlikely that a clinician would perform an expensive test involving radiation dosage to predict the need for, or response to, an injection.
Imaging is probably only of value in elucidating clinically borderline cases or identifying a systemic inflammatory condition. We usually use isotope bone scanning for both indications although are increasingly using as sufficient expertise becomes available locally. Routine Xrays of patients with plantar fascitis are probably not worthwhile.
Other investigations
The only other investigation which is likely to be of value in the occasional patient is nerve conduction testing in suspected tarsal tunnel syndrome. However, the sensitivity of this is probably 90% at most.
Non-surgical management
The majority of patients will resolve on non-surgical management. Sammarco and Helfrey (1996) found that only 3% of 870 patients with plantar fascitis required surgery. In Blackburn we have operated on four of about 400 patients.
Initial management is aimed at symptom control and patient understanding of the problem and includes
- explanation - usually includes disabusing people of the significance of “heel spurs”
- simple advice about obesity and shoewear
- simple analgesia
A number of other treatment methods have been described. Some have been examined in RCTs, although these are often of relatively low quality.
Stretching exercises. Most series assume these as part of general management. Stretching of the Achilles tendon is aimed to improve the range of ankle dorsiflexion, which is often deficient in patients with plantar fascitis. A large multi-centre trial by Pfeffer et al (1999) found that other mechanical treatment added little in effectiveness to stretching. DiGiovanni et al (2003) found that plantar fascial stretching exercises were more effective than Achilles exercises.
Heel cups are intended to reduce forces on the heel and also relax the Achilles tendon.
Dorsiflexion night splint. The rationale is that the Achilles tendon and plantar fascia normally contract at night in the relaxed equinus position, resulting in first-step pain when the tight foot hits the floor. If the ankle and toes are splinted in dorsiflexion this tightening is prevented. Some patients find the splint uncomfortable and stop using it.
Batt (1996) and Powell (1998) reported cross-over studies which offer some support for the use of night splintage, but Probe, in a RCT with longer follow-up and SF-36 generic health outcome measures, found that night splintage offered no advantage over Achilles stretching, NSAIDs and shoe advice. Probe’s patients had a much shorter duration of symptoms before entry into the trial and the natural history of improvement may be more significant in this group of patients than in the chronic patients in Powell’s trial. The place of the night splint requires further study.
Biomechanical treatment. The use of custom moulded orthoses derives from the concept, particularly prevalent in sports medicine and podiatry circles, that plantar fascitis is caused by overpronation, which stretches the plantar fascia. The evidence for this is equivocal, particularly as general populations with plantar fascitis (as distinct from selected athletic populations) have relatively few overpronators. Some practitioners use taping of the heel as an initial or independent step in this biomechanical approach to treatment.
Lynch (1998) found biomechanical treatment to be superior to "anti-inflammatory" treatment with NSAIDs and steroid injections or "accommodative" treatment with a heel cup. Pfeffer (1999), however, found no advantage for biomechanical treatment over stretching or silicone heel cups, although this study has been criticised for its methods of orthotic prescription.
Steroid injections into the origin of the plantar fascia are intended to help resolve inflammation, although plantar fascitis is a non-inflammatory degenerative process. Blockley (1956) found no difference between lignocaine and lignocaine plus steroid, and Lynch (1998) found NSAIDs plus steroid injections inferior to biomechanical treatment, although both trials have significant methodological weaknesses. More recent studies have examined the use of ultrasonography to guide steroid injection. Only one small RCT (Kane et al 2001) has compared ultrasound with palpation guidance of injection, without showing any difference. Steroid injection carries a small risk of plantar fascial rupture or infection. We use it only for resistant cases. If injections are carried out, the medial approach is less unpleasant for the patient than an approach through the heel.
Casting. The concept is of “resting” the plantar fascia; although there is only anecdotal evidence of efficacy, some resistant patients start to settle after a month in a below-knee walking cast. Whether a walker boot would be equally effective, or whether the “effect” is simply the natural history of resolution, can only be answered by trials which have not been done.
Extracorporeal shockwave treatment. This has been used in a number of degenerative soft-tissue conditions for its effects in stimulating tissue repair. Shockwave therapy appears to have different effects at different intensities and doses. High-energy shockwaves require local anaesthesia. There have been many reports of this treatment, mostly of poor methodological quality. Many studies have potential commercial bias.
In summary, the available evidence does not clearly support any particular form of non-surgical treatment. Indeed, as none of these studies included a group which received no treatment or a placebo we do not really know whether any of these other treatments are better than the natural history. Pfeffer et al stated that they felt it unethical not to treat a group and gave their control group stretching exercises. However, as the natural history is not really known and the condition is essentially benign, it does not seem unethical to have an untreated control group in future studies - perhaps the opposite.
Recommendations
There is no clearly superior method of non-surgical treatment. We therefore recommend that first line management be simple and cheap, reserving more expensive treatments for those who fail to respond to simple measures. We recognise that this stance may change if further evidence becomes available.
We recommend that:
- all patients should have a full clinical assessment by a member of a specialist multidisciplinary foot and ankle team
- diagnosis should normally be clinical and investigations should be performed only where there is a reasonable likelihood they will influence management
- inflammatory disease should be considered in every case and investigated where appropriate
- all patients should receive an explanation of the condition and likely treatment which should emphasise its chronic self-limiting nature, self-help, the irrelevance of the spur and the low probability of needing surgery
- initial management should include
- attention to footwear, occupational factors and obesity
- simple analgesia
- stretching
- silicone heel seat where necessary
- patients who remain symptomatic despite compliance with the above should be re-evaluated for underlying disease. If none is found, second line treatment may include:
- a dorsiflexion night splint, especially if morning pain is a prominent symptom
- a customised orthosis in subtalar neutral, especially if the patient overpronates
- anti-inflammatory medication
- patients at any stage who have very severe symptoms, or patients who remain symptomatic after the above treatment, and who still do not have evidence of underlying disease, may be considered for
- a steroid injection into the plantar fascial origin from the medial approach
- a BKW cast or walker boot
- patients who remain symptomatic after the above, who have no evidence of underlying disease and who are within the normal range of weight for height, should be considered for surgery
Surgical management
Surgery is rarely necessary for plantar fascitis. Sammarco and Helfrey (1996) found that only 3% of 870 patients with plantar fascitis required surgery. In Blackburn we have operated on four of 400 patients.
The usual indication for surgery is typical plantar fascitis unresolved after adequate conservative treatment. Most papers which express a view suggest that 6 months' conservative treatment is the minimum before embarking on surgery, although it may also be considered in a few patients with very severe symptoms at an earlier stage. We also require patients to be an appropriate weight for their height.
Procedures proposed
Most recent articles have described release or resection of the plantar fascial insertion from the calcaneum with removal of any spur that may be present. In view of biomechanical studies (Sharkey 1999), showing that partial plantar fascial release has less effect on arch stability than complete release, some surgeons have emphasised partial preservation of the attachment (Sammarco and Helfrey 1996, Davies et al 1999, Conflitti and Tarquinnio 2004); others carry out a full release (Brown et al 1999) or do not specify the extent of release (Daly et al 1992, Schepsis et al 1991). Spurs are often resected but no study has demonstrated that this makes a difference to the result. Indeed, 8 of 16 spurs excised by Tountas and Fornasier reformed without affecting outcome.
In what is perhaps the most realistic report of the results of surgery, Davies et al (1999) found that a combined 50% plantar fascial release and neurolysis of the first branch of the lateral plantar nerve reduced mean visual analogue pain score from 8.5 to 2.5/10, but half still had noticeable pain and restriction of activities at 1-5y follow-up. It took a mean of 8 months to reach the final outcome.
Baxter has claimed that much "plantar fascitis" is actually due to entrapment of the nerve to quadratus plantae, which arises from the lateral plantar nerve in or just below the tarsal tunnel. We believe that this is sometimes discernible as a distinct clinical entity. Baxter recommends nerve decompression alone or with fasciotomy and/or spur resection, reporting complete relief of pain in 83% of patients with a 3-month recovery period. Several series (Davies et al 1999, Conflitti and Tarquinnio 2004) report a similar combined procedure with varied results.
Most studies describe open surgical approaches, usually medial. Brown et al described a transverse plantar approach which they claim reduces post-operative scar problems. Series of endoscopic plantar fasciotomy have been reported with increasing frequency. This is claimed to have a lower morbidity and shorter recovery time. A number of series of endoscopic release have been published (Ogilvie-Harris + Lobo 2000, Blanc et al 2001, Saxena 2004) which seem to be reporting similar results to open procedures. Saxena found that athletic activity and low BMI predicted a better result.
Post-operatively most surgeons appear to have advised non-weightbearing for up to three weeks. However, Tountas and Fornasier allowed free weightbearing from the beginning and produced results comparable to other studies.
Plantar fascial release leads to slight flattening of the arch (Sharkey et al 1998, Jarde et al 2003) and may produce pain in the lateral column of the foot, which is commoner after a release of over 50% of the fascia (Brugh et al 2002).
Historical papers also describe other techniques:
- rotational or countersinking calcaneal osteotomies
- calcaneal drilling
- medial calcaneal neurectomy
Although the papers describing these procedures are of little use in assessing the value of the operations, it is possible that further study of the biology of plantar fascitis may re-awaken interest in them and it is as well to be aware of their existence.
Unfortunately, there are no meaningful studies comparing surgical techniques or post-op management protocols. It would be particularly useful to compare:
- open with arthroscopic surgery
- plantar fascial release and nerve decompression with release alone
- early weightbearing and activity with restricted post-op protocols
Recommendations
We recommend a stringent approach to patient selection for surgery. Patients must have complied with non-surgical treatment and be of appropriate weight for height. We advise patients that surgery has about a 80% success rate and that recovery takes 6 months. We have operated on four patients out of 400, refused two on grounds of severe obesity and had six decline surgery after discussion.
Currently we advocate open surgery through a short medial approach. The nerve to quadratus plantae is sought and decompressed. The medial half of the plantar fascial attachment is released from the calcaneum and any obviously abnormal areas are resected. We do not resect spurs. Post-operatively we allow weight bearing as tolerated and go for early range of motion exercises and desensitisation by massage and careful scar care.
References
- Batt ME et al. Plantar fasciitis: a prospective randomised clinical trial of the tension night splint. Clin J Sports Med 1996;6:158-62
- Gibbon WW, Long G. Ultrasound of the plantar aponeurosis. Skel Radiol 1999;28:21-6
- Pfeffer G et al. Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis. Foot Ankle Int 1999;20:14-21
- Brown JN et al. Plantar fascial release through a transverse plantar incision. Foot Ankle Int 1999;20:364-7
- Powell M et al Effective treatment of chronic plantar fasciitis with dorsiflexion night splints. Foot Ankle Int 1998;19:10-18
- Martin RL et al. Outcome study of subjects with insertional plantar fasciitis. Foot Ankle Int 1998;19:803-11
- Sammarco GJ, Helfrey RB Surgical treatment of recalcritant plantar fasciitis. Foot Ankle Int 1996;17:520-6
- Mizel MS et al. Treatment of plantar fasciitis with a night splint and shoe modification consisting of a steel shank and anterior rocker bottom. Foot Ankle Int 1996;17:732-5
- Daly PD et al. Plantar fasciotomy for intractable plantar fasciitis. Foot Ankle 1992;13:188-95
- Lynch DM et al. Conservative treatment of plantar fasciitis. A prospective study. JAPMA 1998;88:375-80
- Kibler WB et al. Functional biomechanical deficits in runners. AJSM 1991;19:66-71
- Warren BL, Jones CJ. Predicting plantar fascitis in runners. Med Sci Sponts Exerc 1987;19:71-3
- Schepsis AA et al. Plantar fascitis: etiology, treatment, surgical results and review of the literature. CORR 1991;266:185-96
- Tountas AA, Fornasier VL. Operative treatment of subcalcaneal pain. CORR 1996;332:170-8
- Prichasuk S, Subhadrabandhu T. The relationship of pes planus and calcaneal spur to plantar heel pain. CORR 1994;306:192-6
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