- Email: [email protected]
Posterior tibial tendon pathology: the foot at risk and its treatment by os calcis osteotomy
The Foot (1993) 3. 168-174 0
1993 Longman Group UK Ltd
~_fYzig] Posterior tibia1 tendon pathology: the foot at risk and its treatment by OScalcis osteotomy E. A. Welton, G. K. Rose Orthotic Research and Locomotor Assessment Unit, The Robert Jones & Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire, UK SUMMA R Y. A small number of adult seronegative patients present with crippling pain in one or both feet resulting in serious limitation of walking due to tibialis posterior pathology. It is postulated that this is due to the longstanding effects of the so called ‘pronated foot’. Such feet can be either high or low arched, frequently hypermobile, but have inadequate support under the first metatarsal head. The onset can be gradual, with elongation of the tendon and subsequent failure of the compensatory mechanisms with ageing, or suddenly, with tendon rupture. The logical therapeutic implication is to treat the primary cause by recentring the load line within the support area of the foot by an OScalcis osteotomy. A study of 18 patients has identified the ‘foot at risk’ and the results of surgery on 10 feet are analysed.
Efforts to distinguish the pathological ‘flat foot’ amongst the large numbers of children referred with this label have resulted in the functional criteria of pathology being defined. ’ Such feet can be either ‘high’ or ‘low arched’, frequently hypermobile, have the load line falling medial to the support area, inadequate first metatarsal support, some degree of metatarsal outswing in the tarso-metatarsal region resulting in eversion throughout the length of the foot and maldistribution of pressure on pedobarograph examination. Normal feet are inherently stable, dependent on ligamentous integrity. 2*3 The increased mechanical stresses of walking are normally mitigated by muscle activity4*5 but in the unbalanced foot there is a need for increased compensatory intrinsic and extrinsic muscular activity,6*7,8 in particular of the long flexor of the great toe and more importantly, tibialis posterior. Borderline feet may well remain functionally satisfactory and symptom-free for many years with this compensatory mechanism. The anatomy of the tibialis posterior tendon in the ankle region, the angulation in the coronal plain secondary to the foot posture combined with the poor blood supply in this area,’ mean that the tendon is particularly vulnerable to separation of its fibres, with elongation and/or rupture. The latter is sometimes acute. These changes may be delayed by compensatory overactivity of flexor hallucis longus but, clearly, the efficiency of this is reduced in those patients with a pathological degree of hallux valgus.” Clinical estimation of the extent of the tendon pathology is, in general, extremely difficult and most authors are agreed that, until recently, it could only be ascertained by exploration.” CT and MRI
scanning has however, demonstrated three progressive stages: tendon fissuring followed by tearing, elongation with scarring and, finally, in some cases, separation. There may also be involvement of the adjacent flexor digitorum longus tendon.12 As these scans can give false positives, exploration still remains the only way to be certain. Mann, exploring his cases i3 described a variety of findings, from degeneration’ of the tendon with thinning and decreased bulk, to complete rupture with separation ranging from l-7 cm, and in some patients, complete absence of the tendon. Whilst relief of chronic non-specific tenosynovitis of the tibialis posterior, by simple division of its sheath, has been described,14 Fitton” reported disappointing results with this, noting a granular appearance of the tendon. He labelled these cases ‘pseudo-tenosynovitis’. When, however, the condition was associated with plano-valgus feet and tendon rupture, the results of repair have been reported as only fair. l6 This was partly due to the technical difficulty of avoiding local adherence of the repaired tendon and, more importantly, we believe, because the primary cause - mechanical imbalance - was not addressed. Saillant et al” reported results of surgery in 11 cases, several techniques being used: suturing, resection, plastic transfers, or plastic operations. Although the results were satisfactory in 9 cases, foot shape was not restored and the use of a foot support had to be continued. Jahss18 showed good results after follow-up of up to 3 years where side-to-side anastamosis of proximal and distal tendon ends to the adjacent flexor digitorum longus had been carried out, but there was residual ‘valgus’ deformity. In our view the pathological ‘flat foot’ is the cause 168
Posterior
tibia1 tendon
pathology:
of the excessive stresses on the tendon, but when the latter gives way, the foot posture may worsen considerably. The logical implication is to ignore the tendon pathology and to recentre the loadline within the support area of the foot by a combined rotatiomdisplacement OScalcis osteotomy.* A dramatic reduction of pain in patients treated this way has justified this view. In the very hypermobile foot arthrodesis of the basal joint of the first metatarsal may also be required. Recognition of the aetiology has been recorded previously. lg-*’ It is the purpose of this paper to draw attention to the good results of the relatively simple procedure of OScalcis osteotomy for flat foot deformity associated with dysfunction of the tibialis posterior tendon.
PATIENTS AND METHOD Patients 18 adult patients, all seronegative, presenting with severe disability and evidence of posterior tibia1 tendon disruption associated with a pathological degree of ‘flat foot’ deformity were assessed. All had
Fig. I -(A)
Pedobarograph
at ‘foot flat’, and (B) showing
flattening
the foot at risk and its treatment
by OS calcis osteotomy
169
grossly everted heels and abnormal medial pressure distribution on pedobarograph examination. Because the precise clinical diagnosis of tibialis posterior pathology is considered to be impossible, such pathology was assumed if the first criterion described in the list below was combined with four of the others was present: 1. Crippling pain with marked reduction of walking ability, coming on suddenly or slowly over a period of time. 2. Change in foot shape. 3. Calf wasting. 4. Loss of tibialis posterior power. 5. ‘Too many toes sign’, an indicator of forefoot adduction. The foot when viewed from behind showing ‘too many toes laterally’.** 6. Single limb heel rise test’. When attempting to rise on the ball of the foot with the contralateral foot already raised, the normal foot will assume a stable position but does not do so when the tibialis posterior is dysfunctional.** 7. On dynamic pedobarograph recordings of foot/ ground pressure, flattening of the internal longitudinal arch immediately at ‘heel off’ when the tibialis posterior is not functioning normally (Figs IA and 1B).
of the internal
longitudinal
arch at the moment
of ‘heel off’.
170
The Foot
Of the 18 patients, 9 patients (10 feet) were treated with a combined rotation displacement OS calcis osteotomy (one bilateral). In one patient, this was combined with arthrodesis at the basal joint of the first metatarsal, where this joint was very hypermobile. 3 patients await surgery and 5 are using orthosis and do not want surgery for a variety of reasons, social and personal. One was lost to followup following a myocardial infarction. Method Each subject was assessed subjectively, by a standardised questionnaire and objectively, pre- and postoperatively, as appropriate. Objective assessment included a full history, examination of the spine and lower limbs, a record of the range of all foot movements, estimation of joint laxity, particularly at the basal joint of the first metatarsal as shown in Figure 2, pedobarography, close-up walking video recordings and radiology, including Cobey’s views which give a qualitative estimate of heel eversionZ3 (Fig. 3).
RESULTS AND DISCUSSION The 18 patients, female all but one, ranged in age from 47-72 years (mean 56.5 years). 12 were overweight and had a BMI above 25. 14 patients had experienced an acute onset of pain, 5 of these had had chronic symptoms for a few months prior to this and 4 patients had developed pain slowly over some
Fig. 2-Laxity of the basal joint of the first metatarsal tested in the recumbant patient by pushing the outer 4 metatarsals up as far as they will go, then pushing up the first to determine the relative hypermobility of this.
Fig. 3-Cobey’s views. Right showing N.B. tibia and fibula are outlined.
marked
heel eversion.
months. The site of the pain, which was severe, varied from patient to patient, being either in the region of the tibialis posterior muscle or its tendon, around the ankle joint, medial mid-foot or internal longitudinal arch of the foot. 13 patients had noticed a change in foot shape. On inspection and palpation all painful feet showed eversion of the heel, confirmed by Cobey’s views. Pedobarograph studies showed that the foot with symptoms could have a normal, broad or even high arched outline, but demonstrated an abnormal shift of foot/ground pressure along the entire medial plantar contact area as in Figures 4A and 4B. The symptomless feet showed evidence of inadequate support under the first metatarsal head with high pressure under the second, second and third or, in one case, the third metatarsal head (Fig. 5). We have found this forefoot pattern to be present in 22.5% of the normal adult uncomplaining populationz4 In a follow-up of children treated orthotically for ‘flat feet’, this pattern, with the load-line placed centrally within the support area, was noted in 50% of cases on reaching skeletal maturity. Evidence of prolonged increased weightbearing by the second metatarsal was indicated radiologically by hypertrophy of the shaft and thickening of the cortices.” This feature was present in the majority of subjects. Theoretically, lack of support at the antero-medial section of the foot/stool complex could be produced skeletally, by a relatively short first metatarsal or an increased angle between the first and second rays, or functionally, by a failure of support due to laxity at the basal joint of the first metatarsal and mid-tarsal joints, or to a combination of both factors. 83% of feet showed excessive basal joint laxity and 45% had a high intermetatarsal angle as defined radiologically (normal range 8 + 2”).25 This interrelates with the 44% of feet with a hallux valgus deformity clinically of above 30”. 2 of the 3 patients without joint laxity had high intermetatarsal angles. The other patient
Posterior tibia1 tendon pathology: the foot at risk and its treatment by OScalcis osteotomy
Fie. 4-_(A) Abnormal medial uressure in a ‘broad’ foot on pedobarograph arched’ foot on pedobarograph examination.
had a normal intermetatarsal angle and normal second metatarsal radiologically but did show increased weight bearing beneath the second metatarsal head. The dynamic pedobarograph recordings in all painful feet revealed increased activity of the long toe flexors, particularly at the point of ‘heel off’ with high pressure beneath the toe tips as seen in Figures IA, 1B, 4A and 4B. Close-up video recordings confirmed active clawing of the outer toes with this compensatory muscular activity.
RESULTS OF TREATMENT BY OS CALCIS OSTEOTOMY AND DISCUSSION
The results of 10 operations in 9 patients were assessed. Foilow-up was from 7-42 months (mean 17.9 months). 1. Subjective assessment
Subjective assessment of pain relief is patients’ expectations and lifestyles differ All patients reported complete relief original pain. 3 patients had some minimal
difficult as greatly. from their discomfort
171
examination, (B) Abnormal medial pressure in a ‘high-
after exercise, 1 in the internal longitudinal arch, another around the lateral malleolus and the other in the lower third of tibialis posterior. None were severe enough to cause limitation of activity. 7 patients could walk as far as they wished postoperatively. One patient, a busy farmer’s wife walking on rough ground most of the day, had increased mobility but was still slightly troubled by aching in the internal longitudinal arch, preferring to wear a supportive shoe and arch support. With her extreme joint mobility in the mid-foot she may well have benefited from a fusion at the basal joint of the first metatarsal. A further patient said that he could walk anywhere with the aid of a stick. He had developed metatarsalgia. All patients reported a stable ankle and only one patient was disappointed that there was little change in foot shape, the remainder being pleased with the improvement. Post-operative complications were few, either minor or short-term, apart from 2 patients who developed deep venous thrombosis. The remaining problems were related to the resultant change in the forefoot posture and pressure distribution. 2 patients developed metatarsalgia, 1 with mild discomfort under the second and third metatarsal heads, but the
172 The Foot
Fig. 6-Pre-operative (L) and post-operative (R) pedobarograph recordings of the same foot.
Fig. S-Pedobarograph showing inadequate weight bearing under the 1st metatarasal head.
other developed severe pain under all metatarsal heads and the dorsum of the proximal interphalangeal joints where these were clawed. The dorsum of the second distal interphalangeal joint became painful with clawing in 1 patient and another patient complained that the great toenail now rubbed the upper of the shoe, the only patient to have restriction in choice of footwear post-operatively. Overall assessment of the operation by the patient: 4 - excellent; 3 - good; 2 - better; 1 - better (but objective assessment showed that his mobility was worse due to metatarsalgia). All patients were pleased with improvement and none said that they were worse. Patients volunteered the information that they only felt the full benefit of the operation after a period of 6 months.
still had some degree of pressure under the first metatarsal head. This patient was disappointed that there wasn’t a great change in foot shape and, on inspection, the heel was still somewhat everted. One foot showed the pressure to pass normally down the lateral border of the foot and normally across the metatarsal heads, but still showed a high pressure area beneath the first metatarsal head due, in this instance, to a marked degree of hallux valgus. Improved heel alignment was noted clinically (Figs 7A and B), confirmed by Cobey’s views in 8 cases, with great improvement in foot shape. 2 feet showed little change clinically, but there was improvement in the pedobarograph recordings. In the 2 patients with metatarsalgia, particularly in one, there was marked loss of sub-cutaneous tissue under the metatarsal heads. This had not been present pre-operatively. Other clinical findings were similar pre- and postoperatively. The power of the tibialis posterior was predictably not altered, but (post-operatively) no patient showed collapse of the internal longitudinal arch on pedobarograph examination. Gait studies, in general, showed improvement with an increase in stability, speed and cadence, decreased doublesupport time, increased swing phase and decreased stance phase. There was a reduction in the foot angle in the post-operative foot.
CONCLUSIONS
2. Objective assessment Pedobarograph examination showed that in 9 feet, post-operatively, the pressure had moved laterally to within the support area of the foot to reveal higher pressure areas under the second, second and third metatarsal heads or, in one case, the third metatarsal head, with little support under the first (Fig. 6). One foot, although showing a lateral shift of pressure,
The foot likely to develop posterior tibia1 tendon pathology in later life is the unstable high or low arched foot having inadequate support at the anteromedial border, frequently associated with laxity at the basal joint of the first metatarsal. The patient most at risk is ‘fat, female and over forty’. Results of a rotational/displacement osteotomy in 10 such feet showed, in all, relief from the severe
Posterior tibia1 tendon pathology: the foot at risk and its treatment by OScalcis osteotomy
Fig. 7-Photographs.
173
pre (A) and post (B) bilateral OScalcis osteotomies.
pain, increased level of activity, a stable ankle and improved foot posture. Pedobarograph recordings showed that, in all, the load line had been restored to fall within the support area of the foot. Patients who did not report the end result as excellent were those experiencing minor problems due to the change in posture and pressure of the forefoot. Careful pre-operative evaluation of the forefoot and toes could predict these in many cases and toe deformities could be corrected at the same time as the OS calcis osteotomy to prevent later problems. Where there is increased mobility in the mid-tarsal region a fusion of the basal joint of the first metatarsal should be considered. Although the foot at risk from tibialis posterior pathology is identifiable when symptom-free, it would hardly be practical for the individual to use a protective orthosis all his or her life. Severe problems however. could be avoided by the use of the appropriate orthosis in patients (presenting with minor complaints of pain) with a foot known to be ‘at risk’. Acknowledgements We would like to thank the members of the Naughton Dunn Club, who have shown interest and kindly supplied us with patients for
this study and also the staff of the Orthotic Research and Locomotor Assessment Unit at the Robert Jones & Agnes Hunt Orthopaedic Hospital, Oswestry, for their assistance.
References I. Rose G K, Welton E A, Marshall T. The Diagnosis
2.
3.
4.
5. 6.
7.
8. 9.
of flat foot in the child. J Bone Joint Surg 1985; 67-B: 71-78. Rose G K. Pes Planus. In: Jahss M H, (ed). Disorders of the foot and ankle. Philadelphia, Eastbourne, Toronto: W B Saunders Company, 1991; pp. 892-920. Basmajian J V, Bentzon J W. Electomyographic study of certain muscles of the leg and foot in the standing position. Surg Gynecol Obstet 1954; 98: 662-666. Morton D J. Human locomotion and body form. A study of gravity and man. Baltimore: The Williams & Wilkins Co.. 1952. Basmajian J V, De Luca C J. Muscles Alive. Baltimore: The Williams & Wilkins Co.. 1985. Mann R. Inman V T. Phasic activity of intrinsic muscles of the foot. J Bone Joint Surg 19 64; 46-A: 469-48 I. Gray E R, Basmajian J V. Electromyography and cinematography of the leg and foot (‘normal and flat’) during walking. Anat Ret 1968; 161: l-15. Gray E R. The role of leg muscles in variations of the arches in normal and flat feet. Phys Ther 1969: 49: 1084-1088. Jahss M H. Tendon disorders of the foot and ankle. In: Jahss M H, (ed). Disorders of the foot and ankle. Philadelphia, Eastbourne, Toronto: W B Saunders Company. 1991; 1461-1513.
174 The Foot 10. Hardy R H, Clapham J C H. Observations on Hallux Valgus. J Bone Joint Surg 1951; 33B: 376-391. Il. Funk D A. Cass J R. Johnson K A. Acauired adult flat foot secondary to posterior tibia1 tendon pathology. J Bone Joint Surg 1986; 68A: 95-102. 12. Jahss M H, Rosenberg Z, Cheung Y. The anatomy, pathology and management of degenerative changes of the tibialis aosterior tendon. Proc Brit Orthop Foot Surgery Sot. J Bone Joint Surg 1988; 70-B: 5, 853. 13. Mann R A, Thompson F M. Rupture of the posterior tibia1 tendon causing flat foot. J Bone Joint Surn 1985; 67A: 556-561: 14. Williams R. Chronic non-specific tendovaginitis of tibialis posterior. J Bone Joint Surg 1963; 45B: 542-545. 15. Fitton J M. Non-specific tendo-vaginitis of tibialis posterior: a wrong diagnosis. J Bone Joint Surg 1986; 68B: 843. 16. Kettelcamp D B, Alexander H H. Spontaneous rupture of the posterior tibia1 tendon. J Bone Joint Surg 1969; 51A: 759-764. 17. Saillant G, de Labareyre H, Roy-Camille R. Ruptures of the tibialis posterior tendon. A clinical and therapeutic study apropos of 13 cases. Revue De Chirurgie Orthopedique Et Reparatrice De L’Appareil Moteur. 1990; 76(S): 559-567. 18. Jahss M H. Spontaneous rupture of the tibialis posterior tendon: clinical findings, tenographic studies, and a new technique of repair. Foot Ankle 1982; 3(3): 156-166. 19. Banks A S, McGlamry E D. Tibialis posterior tendon rupture. J Am Pod Med Ass 1987; 77(4): 170-176.
20. Mueller T J. Ruptures and lacerations of the tibialis posterior tendon. J Am Pod Med Ass 1984; 74: 109-119. 21. Muellar T J. Acquired flatfoot secondary to tibialis posterior dysfunction: biomechanical aspects. J Foot Surg 1991; 30(l): 2-l 1. 22. Johnson K A. Tibialis posterior tendon rupture. Clin Orthop 1983; 177: 140-147. 23. Cobey J C. Posterior roentgenogram of the foot. Clin Orthop 1976; 118: 202-207. 24. Welton E A. The Harris and Beath Footprint: Interpretation and clinical use. Foot Ankle 1992; 13: 462468. 25. Gamble F 0, Yale I. Clinical Foot Roentgenology. Huntington, New York: Robert E Krieger Publishing Company, 1975.
The authors E. Ann Welton MB, ChB Clinical Assistant Orthotic Research and Locomotor Assessment Unit Gordon K. Rose OBE, FRCS Honorary Orthopaedic Consultant The Robert Jones & Agnes Hunt Orthopaedic Hospital Oswestry Shropshire SY 10 7AG UK Correspondence
to Dr E. Ann Welton
1993 Longman Group UK Ltd
~_fYzig] Posterior tibia1 tendon pathology: the foot at risk and its treatment by OScalcis osteotomy E. A. Welton, G. K. Rose Orthotic Research and Locomotor Assessment Unit, The Robert Jones & Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire, UK SUMMA R Y. A small number of adult seronegative patients present with crippling pain in one or both feet resulting in serious limitation of walking due to tibialis posterior pathology. It is postulated that this is due to the longstanding effects of the so called ‘pronated foot’. Such feet can be either high or low arched, frequently hypermobile, but have inadequate support under the first metatarsal head. The onset can be gradual, with elongation of the tendon and subsequent failure of the compensatory mechanisms with ageing, or suddenly, with tendon rupture. The logical therapeutic implication is to treat the primary cause by recentring the load line within the support area of the foot by an OScalcis osteotomy. A study of 18 patients has identified the ‘foot at risk’ and the results of surgery on 10 feet are analysed.
Efforts to distinguish the pathological ‘flat foot’ amongst the large numbers of children referred with this label have resulted in the functional criteria of pathology being defined. ’ Such feet can be either ‘high’ or ‘low arched’, frequently hypermobile, have the load line falling medial to the support area, inadequate first metatarsal support, some degree of metatarsal outswing in the tarso-metatarsal region resulting in eversion throughout the length of the foot and maldistribution of pressure on pedobarograph examination. Normal feet are inherently stable, dependent on ligamentous integrity. 2*3 The increased mechanical stresses of walking are normally mitigated by muscle activity4*5 but in the unbalanced foot there is a need for increased compensatory intrinsic and extrinsic muscular activity,6*7,8 in particular of the long flexor of the great toe and more importantly, tibialis posterior. Borderline feet may well remain functionally satisfactory and symptom-free for many years with this compensatory mechanism. The anatomy of the tibialis posterior tendon in the ankle region, the angulation in the coronal plain secondary to the foot posture combined with the poor blood supply in this area,’ mean that the tendon is particularly vulnerable to separation of its fibres, with elongation and/or rupture. The latter is sometimes acute. These changes may be delayed by compensatory overactivity of flexor hallucis longus but, clearly, the efficiency of this is reduced in those patients with a pathological degree of hallux valgus.” Clinical estimation of the extent of the tendon pathology is, in general, extremely difficult and most authors are agreed that, until recently, it could only be ascertained by exploration.” CT and MRI
scanning has however, demonstrated three progressive stages: tendon fissuring followed by tearing, elongation with scarring and, finally, in some cases, separation. There may also be involvement of the adjacent flexor digitorum longus tendon.12 As these scans can give false positives, exploration still remains the only way to be certain. Mann, exploring his cases i3 described a variety of findings, from degeneration’ of the tendon with thinning and decreased bulk, to complete rupture with separation ranging from l-7 cm, and in some patients, complete absence of the tendon. Whilst relief of chronic non-specific tenosynovitis of the tibialis posterior, by simple division of its sheath, has been described,14 Fitton” reported disappointing results with this, noting a granular appearance of the tendon. He labelled these cases ‘pseudo-tenosynovitis’. When, however, the condition was associated with plano-valgus feet and tendon rupture, the results of repair have been reported as only fair. l6 This was partly due to the technical difficulty of avoiding local adherence of the repaired tendon and, more importantly, we believe, because the primary cause - mechanical imbalance - was not addressed. Saillant et al” reported results of surgery in 11 cases, several techniques being used: suturing, resection, plastic transfers, or plastic operations. Although the results were satisfactory in 9 cases, foot shape was not restored and the use of a foot support had to be continued. Jahss18 showed good results after follow-up of up to 3 years where side-to-side anastamosis of proximal and distal tendon ends to the adjacent flexor digitorum longus had been carried out, but there was residual ‘valgus’ deformity. In our view the pathological ‘flat foot’ is the cause 168
Posterior
tibia1 tendon
pathology:
of the excessive stresses on the tendon, but when the latter gives way, the foot posture may worsen considerably. The logical implication is to ignore the tendon pathology and to recentre the loadline within the support area of the foot by a combined rotatiomdisplacement OScalcis osteotomy.* A dramatic reduction of pain in patients treated this way has justified this view. In the very hypermobile foot arthrodesis of the basal joint of the first metatarsal may also be required. Recognition of the aetiology has been recorded previously. lg-*’ It is the purpose of this paper to draw attention to the good results of the relatively simple procedure of OScalcis osteotomy for flat foot deformity associated with dysfunction of the tibialis posterior tendon.
PATIENTS AND METHOD Patients 18 adult patients, all seronegative, presenting with severe disability and evidence of posterior tibia1 tendon disruption associated with a pathological degree of ‘flat foot’ deformity were assessed. All had
Fig. I -(A)
Pedobarograph
at ‘foot flat’, and (B) showing
flattening
the foot at risk and its treatment
by OS calcis osteotomy
169
grossly everted heels and abnormal medial pressure distribution on pedobarograph examination. Because the precise clinical diagnosis of tibialis posterior pathology is considered to be impossible, such pathology was assumed if the first criterion described in the list below was combined with four of the others was present: 1. Crippling pain with marked reduction of walking ability, coming on suddenly or slowly over a period of time. 2. Change in foot shape. 3. Calf wasting. 4. Loss of tibialis posterior power. 5. ‘Too many toes sign’, an indicator of forefoot adduction. The foot when viewed from behind showing ‘too many toes laterally’.** 6. Single limb heel rise test’. When attempting to rise on the ball of the foot with the contralateral foot already raised, the normal foot will assume a stable position but does not do so when the tibialis posterior is dysfunctional.** 7. On dynamic pedobarograph recordings of foot/ ground pressure, flattening of the internal longitudinal arch immediately at ‘heel off’ when the tibialis posterior is not functioning normally (Figs IA and 1B).
of the internal
longitudinal
arch at the moment
of ‘heel off’.
170
The Foot
Of the 18 patients, 9 patients (10 feet) were treated with a combined rotation displacement OS calcis osteotomy (one bilateral). In one patient, this was combined with arthrodesis at the basal joint of the first metatarsal, where this joint was very hypermobile. 3 patients await surgery and 5 are using orthosis and do not want surgery for a variety of reasons, social and personal. One was lost to followup following a myocardial infarction. Method Each subject was assessed subjectively, by a standardised questionnaire and objectively, pre- and postoperatively, as appropriate. Objective assessment included a full history, examination of the spine and lower limbs, a record of the range of all foot movements, estimation of joint laxity, particularly at the basal joint of the first metatarsal as shown in Figure 2, pedobarography, close-up walking video recordings and radiology, including Cobey’s views which give a qualitative estimate of heel eversionZ3 (Fig. 3).
RESULTS AND DISCUSSION The 18 patients, female all but one, ranged in age from 47-72 years (mean 56.5 years). 12 were overweight and had a BMI above 25. 14 patients had experienced an acute onset of pain, 5 of these had had chronic symptoms for a few months prior to this and 4 patients had developed pain slowly over some
Fig. 2-Laxity of the basal joint of the first metatarsal tested in the recumbant patient by pushing the outer 4 metatarsals up as far as they will go, then pushing up the first to determine the relative hypermobility of this.
Fig. 3-Cobey’s views. Right showing N.B. tibia and fibula are outlined.
marked
heel eversion.
months. The site of the pain, which was severe, varied from patient to patient, being either in the region of the tibialis posterior muscle or its tendon, around the ankle joint, medial mid-foot or internal longitudinal arch of the foot. 13 patients had noticed a change in foot shape. On inspection and palpation all painful feet showed eversion of the heel, confirmed by Cobey’s views. Pedobarograph studies showed that the foot with symptoms could have a normal, broad or even high arched outline, but demonstrated an abnormal shift of foot/ground pressure along the entire medial plantar contact area as in Figures 4A and 4B. The symptomless feet showed evidence of inadequate support under the first metatarsal head with high pressure under the second, second and third or, in one case, the third metatarsal head (Fig. 5). We have found this forefoot pattern to be present in 22.5% of the normal adult uncomplaining populationz4 In a follow-up of children treated orthotically for ‘flat feet’, this pattern, with the load-line placed centrally within the support area, was noted in 50% of cases on reaching skeletal maturity. Evidence of prolonged increased weightbearing by the second metatarsal was indicated radiologically by hypertrophy of the shaft and thickening of the cortices.” This feature was present in the majority of subjects. Theoretically, lack of support at the antero-medial section of the foot/stool complex could be produced skeletally, by a relatively short first metatarsal or an increased angle between the first and second rays, or functionally, by a failure of support due to laxity at the basal joint of the first metatarsal and mid-tarsal joints, or to a combination of both factors. 83% of feet showed excessive basal joint laxity and 45% had a high intermetatarsal angle as defined radiologically (normal range 8 + 2”).25 This interrelates with the 44% of feet with a hallux valgus deformity clinically of above 30”. 2 of the 3 patients without joint laxity had high intermetatarsal angles. The other patient
Posterior tibia1 tendon pathology: the foot at risk and its treatment by OScalcis osteotomy
Fie. 4-_(A) Abnormal medial uressure in a ‘broad’ foot on pedobarograph arched’ foot on pedobarograph examination.
had a normal intermetatarsal angle and normal second metatarsal radiologically but did show increased weight bearing beneath the second metatarsal head. The dynamic pedobarograph recordings in all painful feet revealed increased activity of the long toe flexors, particularly at the point of ‘heel off’ with high pressure beneath the toe tips as seen in Figures IA, 1B, 4A and 4B. Close-up video recordings confirmed active clawing of the outer toes with this compensatory muscular activity.
RESULTS OF TREATMENT BY OS CALCIS OSTEOTOMY AND DISCUSSION
The results of 10 operations in 9 patients were assessed. Foilow-up was from 7-42 months (mean 17.9 months). 1. Subjective assessment
Subjective assessment of pain relief is patients’ expectations and lifestyles differ All patients reported complete relief original pain. 3 patients had some minimal
difficult as greatly. from their discomfort
171
examination, (B) Abnormal medial pressure in a ‘high-
after exercise, 1 in the internal longitudinal arch, another around the lateral malleolus and the other in the lower third of tibialis posterior. None were severe enough to cause limitation of activity. 7 patients could walk as far as they wished postoperatively. One patient, a busy farmer’s wife walking on rough ground most of the day, had increased mobility but was still slightly troubled by aching in the internal longitudinal arch, preferring to wear a supportive shoe and arch support. With her extreme joint mobility in the mid-foot she may well have benefited from a fusion at the basal joint of the first metatarsal. A further patient said that he could walk anywhere with the aid of a stick. He had developed metatarsalgia. All patients reported a stable ankle and only one patient was disappointed that there was little change in foot shape, the remainder being pleased with the improvement. Post-operative complications were few, either minor or short-term, apart from 2 patients who developed deep venous thrombosis. The remaining problems were related to the resultant change in the forefoot posture and pressure distribution. 2 patients developed metatarsalgia, 1 with mild discomfort under the second and third metatarsal heads, but the
172 The Foot
Fig. 6-Pre-operative (L) and post-operative (R) pedobarograph recordings of the same foot.
Fig. S-Pedobarograph showing inadequate weight bearing under the 1st metatarasal head.
other developed severe pain under all metatarsal heads and the dorsum of the proximal interphalangeal joints where these were clawed. The dorsum of the second distal interphalangeal joint became painful with clawing in 1 patient and another patient complained that the great toenail now rubbed the upper of the shoe, the only patient to have restriction in choice of footwear post-operatively. Overall assessment of the operation by the patient: 4 - excellent; 3 - good; 2 - better; 1 - better (but objective assessment showed that his mobility was worse due to metatarsalgia). All patients were pleased with improvement and none said that they were worse. Patients volunteered the information that they only felt the full benefit of the operation after a period of 6 months.
still had some degree of pressure under the first metatarsal head. This patient was disappointed that there wasn’t a great change in foot shape and, on inspection, the heel was still somewhat everted. One foot showed the pressure to pass normally down the lateral border of the foot and normally across the metatarsal heads, but still showed a high pressure area beneath the first metatarsal head due, in this instance, to a marked degree of hallux valgus. Improved heel alignment was noted clinically (Figs 7A and B), confirmed by Cobey’s views in 8 cases, with great improvement in foot shape. 2 feet showed little change clinically, but there was improvement in the pedobarograph recordings. In the 2 patients with metatarsalgia, particularly in one, there was marked loss of sub-cutaneous tissue under the metatarsal heads. This had not been present pre-operatively. Other clinical findings were similar pre- and postoperatively. The power of the tibialis posterior was predictably not altered, but (post-operatively) no patient showed collapse of the internal longitudinal arch on pedobarograph examination. Gait studies, in general, showed improvement with an increase in stability, speed and cadence, decreased doublesupport time, increased swing phase and decreased stance phase. There was a reduction in the foot angle in the post-operative foot.
CONCLUSIONS
2. Objective assessment Pedobarograph examination showed that in 9 feet, post-operatively, the pressure had moved laterally to within the support area of the foot to reveal higher pressure areas under the second, second and third metatarsal heads or, in one case, the third metatarsal head, with little support under the first (Fig. 6). One foot, although showing a lateral shift of pressure,
The foot likely to develop posterior tibia1 tendon pathology in later life is the unstable high or low arched foot having inadequate support at the anteromedial border, frequently associated with laxity at the basal joint of the first metatarsal. The patient most at risk is ‘fat, female and over forty’. Results of a rotational/displacement osteotomy in 10 such feet showed, in all, relief from the severe
Posterior tibia1 tendon pathology: the foot at risk and its treatment by OScalcis osteotomy
Fig. 7-Photographs.
173
pre (A) and post (B) bilateral OScalcis osteotomies.
pain, increased level of activity, a stable ankle and improved foot posture. Pedobarograph recordings showed that, in all, the load line had been restored to fall within the support area of the foot. Patients who did not report the end result as excellent were those experiencing minor problems due to the change in posture and pressure of the forefoot. Careful pre-operative evaluation of the forefoot and toes could predict these in many cases and toe deformities could be corrected at the same time as the OS calcis osteotomy to prevent later problems. Where there is increased mobility in the mid-tarsal region a fusion of the basal joint of the first metatarsal should be considered. Although the foot at risk from tibialis posterior pathology is identifiable when symptom-free, it would hardly be practical for the individual to use a protective orthosis all his or her life. Severe problems however. could be avoided by the use of the appropriate orthosis in patients (presenting with minor complaints of pain) with a foot known to be ‘at risk’. Acknowledgements We would like to thank the members of the Naughton Dunn Club, who have shown interest and kindly supplied us with patients for
this study and also the staff of the Orthotic Research and Locomotor Assessment Unit at the Robert Jones & Agnes Hunt Orthopaedic Hospital, Oswestry, for their assistance.
References I. Rose G K, Welton E A, Marshall T. The Diagnosis
2.
3.
4.
5. 6.
7.
8. 9.
of flat foot in the child. J Bone Joint Surg 1985; 67-B: 71-78. Rose G K. Pes Planus. In: Jahss M H, (ed). Disorders of the foot and ankle. Philadelphia, Eastbourne, Toronto: W B Saunders Company, 1991; pp. 892-920. Basmajian J V, Bentzon J W. Electomyographic study of certain muscles of the leg and foot in the standing position. Surg Gynecol Obstet 1954; 98: 662-666. Morton D J. Human locomotion and body form. A study of gravity and man. Baltimore: The Williams & Wilkins Co.. 1952. Basmajian J V, De Luca C J. Muscles Alive. Baltimore: The Williams & Wilkins Co.. 1985. Mann R. Inman V T. Phasic activity of intrinsic muscles of the foot. J Bone Joint Surg 19 64; 46-A: 469-48 I. Gray E R, Basmajian J V. Electromyography and cinematography of the leg and foot (‘normal and flat’) during walking. Anat Ret 1968; 161: l-15. Gray E R. The role of leg muscles in variations of the arches in normal and flat feet. Phys Ther 1969: 49: 1084-1088. Jahss M H. Tendon disorders of the foot and ankle. In: Jahss M H, (ed). Disorders of the foot and ankle. Philadelphia, Eastbourne, Toronto: W B Saunders Company. 1991; 1461-1513.
174 The Foot 10. Hardy R H, Clapham J C H. Observations on Hallux Valgus. J Bone Joint Surg 1951; 33B: 376-391. Il. Funk D A. Cass J R. Johnson K A. Acauired adult flat foot secondary to posterior tibia1 tendon pathology. J Bone Joint Surg 1986; 68A: 95-102. 12. Jahss M H, Rosenberg Z, Cheung Y. The anatomy, pathology and management of degenerative changes of the tibialis aosterior tendon. Proc Brit Orthop Foot Surgery Sot. J Bone Joint Surg 1988; 70-B: 5, 853. 13. Mann R A, Thompson F M. Rupture of the posterior tibia1 tendon causing flat foot. J Bone Joint Surn 1985; 67A: 556-561: 14. Williams R. Chronic non-specific tendovaginitis of tibialis posterior. J Bone Joint Surg 1963; 45B: 542-545. 15. Fitton J M. Non-specific tendo-vaginitis of tibialis posterior: a wrong diagnosis. J Bone Joint Surg 1986; 68B: 843. 16. Kettelcamp D B, Alexander H H. Spontaneous rupture of the posterior tibia1 tendon. J Bone Joint Surg 1969; 51A: 759-764. 17. Saillant G, de Labareyre H, Roy-Camille R. Ruptures of the tibialis posterior tendon. A clinical and therapeutic study apropos of 13 cases. Revue De Chirurgie Orthopedique Et Reparatrice De L’Appareil Moteur. 1990; 76(S): 559-567. 18. Jahss M H. Spontaneous rupture of the tibialis posterior tendon: clinical findings, tenographic studies, and a new technique of repair. Foot Ankle 1982; 3(3): 156-166. 19. Banks A S, McGlamry E D. Tibialis posterior tendon rupture. J Am Pod Med Ass 1987; 77(4): 170-176.
20. Mueller T J. Ruptures and lacerations of the tibialis posterior tendon. J Am Pod Med Ass 1984; 74: 109-119. 21. Muellar T J. Acquired flatfoot secondary to tibialis posterior dysfunction: biomechanical aspects. J Foot Surg 1991; 30(l): 2-l 1. 22. Johnson K A. Tibialis posterior tendon rupture. Clin Orthop 1983; 177: 140-147. 23. Cobey J C. Posterior roentgenogram of the foot. Clin Orthop 1976; 118: 202-207. 24. Welton E A. The Harris and Beath Footprint: Interpretation and clinical use. Foot Ankle 1992; 13: 462468. 25. Gamble F 0, Yale I. Clinical Foot Roentgenology. Huntington, New York: Robert E Krieger Publishing Company, 1975.
The authors E. Ann Welton MB, ChB Clinical Assistant Orthotic Research and Locomotor Assessment Unit Gordon K. Rose OBE, FRCS Honorary Orthopaedic Consultant The Robert Jones & Agnes Hunt Orthopaedic Hospital Oswestry Shropshire SY 10 7AG UK Correspondence
to Dr E. Ann Welton