Chapter 14 Lower Limb Conditions - Boston Brace

507Lower Limb Conditions

Chapter 14Lower LimbConditions

Aetiological classificationAnatomical classification

Hip and femur Knee and tibia Ankle and hindfoot

Forefoot and toes

508 A Simple Guide to Orthopaedics

Classification

AetiologicalClassificationCongenital abnormalities

Dwarfism - achondroplasiacretinismgargoylism

Amelia and phocomeliaCDH and protrusio acetabuliCoxa vara and valgaGenu varum, valgum and recurvatumTalipesCongenital vertical talusTalocalcaneal - navicular barPes planus and cavusMetatarsus primus varusMacrodactylySyndactyly and webbing

NeoplasiaBenign - bony

cartilaginoussoft tissue

Malignant - primary - bonycartilaginoussoft tissue

secondary

TraumaSoft tissue injuries - tendons and

ligamentsnervesvessels

Subluxation and dislocationFractures


InfectionSoft tissueBoneJoint

ArthritisDegenerative (primary or secondary oste-

oarthritis)AutoimmuneMetabolicHaemophilic arthropathy

ParalysisCerebral

cerebral palsyneoplasiavascular conditionstrauma

Spinaldisc protrusionfracturesspina bifidasyringomyeliapoliomyelitis

Peripheral nervesperipheral neuritis and toxinsdiabetic neuropathy

Anatomical ClassificationHip and femur

Knee and tibia

Ankle and hindfoot

Forefoot and toes


AetiologicalClassificationMost conditions of the lower limb are dis-cussed in detail in the relevant sections ofthis book. It is the purpose of this chapterto discuss other conditions which do notfall into any of the other categories. Con-ditions discussed in other chapters are givenbelow.

Congenital abnormalitiesDevelopmental abnormalities include limbdefects, such as overgrowth and fusion, aswell as congenital dislocation of the hipand bilateral coxa and genu vara and valga.

They also include ankle and foot condi-tions such as talipes equino varus, congenitalvertical talus, metatarsus primus varus andother foot deformities.

Generalised developmental conditionsinclude achondroplasia and polyostoticfibrous dysplasia.

NeoplasiaDevelopmental tumours include multiple os-teochondroma (diaphyseal aclasis) and be-nign bone cysts as well as multipleneurofibroma. Most tumours, however, are ofunknown origin and develop in childhood oradult life. They range from benign tumourssuch as aneurysmal bone cysts, eosinophilicgranuloma and non-ossifying fibromata, tomalignant tumours such as osteogenic


Genu valgum Osteogenic sarcoma

Aetiological Classification

Trauma Infection

Neoplasia

X-ray appearanceof osteomyelitis

Deformity due totibial trauma

Congenitalabnormalities

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sarcoma, chondrosarcoma and Ewing’ssarcoma.

TraumaVarious chapters discuss both recentand old injuries to bones, ligaments,tendons and other structures. It is es-pecially important to consider traumaas an aetiological factor when dealingwith swellings associated with the bone,as the differential diagnosis includesboth inflammatory and neoplasticconditions.

InfectionA low grade osteomyelitis of the femuror tibia, or a pyogenic arthritis ofthe hip or knee sometimes is difficultto differentiate from tumours or otherinflammatory conditions such asrheumatoid arthritis.

ArthritisOsteoarthritis of the hip and knee iscommon and rheum-atoid arthritis canoccur in major joints as well as in thehands and feet. Arthritis may also bedue to gout, haemophilia and other non-infective conditions.

ParalysisParalysis of the lower limb may be causedby cerebral, spinal cord or peripheralnerve lesions or a combination of these.They include cerebral palsy, head inju-ries, spina bifida and poliomyelitis.

Miscellaneous conditionsA miscellaneous group of conditionsincludes Paget’s disease, hallux valgusand plantar fasciitis.


Aetiological Classification

Poliomyelitis Hallux valgus

X-ray appearance ofosteoarthritis

Rheumatoid arthritis

Miscellaneousconditions

Paralysis

Arthritis

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Anatomical Classification

Hip and femoral conditions

Paget’s diseasePaget’s disease affecting the femur is fairlycommon and may cause overgrowth, bowing,pathological fractures and, rarely, osteogenicsarcoma.

InfectionSecondary osteomyelitis is more common thanprimary osteomyelitis and usually followsoperative internal fixa-tion of hip or femuror open femoral fractures. Pyogenic arthritisof the hip is still fairly common, particu-larly in children and is usually due to bloodborne spread.

Snapping hipThis is a fairly common condition resultingfrom the ilio-tibial band catching over thegreater trochanter. It may be due to unac-customed exercise and can cause inflamma-tion of the bursa over the greater trochan-ter.

This condition will usually respond torest and anti-inflammatory drugs. Itoccasionally requires division of the ilio-tibial band in the mid thigh.

Tom Smith’s disease and Girdlestone’sarthroplastyTom Smith’s disease is a septic arthritis ofa major joint occurring in the first year of


X-ray appearanceof osteomyelitis

X-ray appearanceof an infected hip

Hip and Femoral Conditions

X-ray appearance ofPaget’s disease

Trochantericbursitis

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life and leading to complete destruction ofthe joint. It is now uncommon except indeveloping countries.

A similar, but more common situation, occursfollowing Girdlestone’s procedure. This isan excision arthroplasty of the hip which isperformed following an unresolved infectioncomplicating total hip arthroplasty.

Both arthroplasties may present as atelescoping unstable hip requiring later hipreplacement.

Avascular hip conditionsPerthes’ disease is due to avascular changesin the head of the femur. It occurs mostcommonly between the ages of 5 and 10 years.It is discussed in more detail in Chapter 7.Avascular changes of the head of the femuralso occur in sickle cell disease and inslipped epiphyses in children. In adults,avascular changes may follow hip disloca-tion or subcapital fractures of the femur.

These changes also occur in chronic alco-holism and following prolongedglucocorticosteroid therapy, espec-ially inpatients who have undergone renal or otherorgan transplantation.

Slipped capital femoral epiphysisSlipped epiphysis is discussed in more detailin chapter 7 and occurs most commonly betweenthe ages of 10 and 15 years. Although traumaplays a part in some cases, in many childrenan imbalance of sex and growth hormones isthought to be responsible.


Hip and Femoral Conditions

X-ray appearance of TomSmith’s disease and

Girdlestone’sarthroplasty

X-ray appearance ofslipped capital femoral

epiphysis

X-ray appearance ofPerthes’ disease

X-ray appearance ofavascular necrosis

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Knee and tibial conditions

Baker’s cyst and semimembranosusbursaThis is a cystic swelling in the poplitealfossa usually due to synovial outpouchingfrom an osteoarthritic knee. Other causes ofchronic arthritis with effusion in the kneecan also lead to a Baker’s cyst.

The differential diagnosis of poplitealswellings includes lymph nodes, a poplitealaneurysm and a semimembranosus bursa.

Treatment is of the underlying conditionand occas-ionally excision of the cyst.

BursitisPrepatellar bursitis (housemaid’s knee) isdue to traumatic or infective inflammationof the prepatellar bursa, that is, the bursain front of the knee.

Infrapatellar bursitis (clergyman’s knee)has similar causes.

A suprapatellar bursa is an outpouchingof synovial fluid and synovia in the kneeitself. It is particularly prominent inchronic osteoarthritis, and also occurs withany knee effusion.

Osgood-Schlatter’s diseaseThis is a traction osteochondritis of thetibial tubercle and is most common in boysof about 14 years of age. Such tractioninjuries often result from kicking footballsor jumping.

There is tenderness and bony swelling overthe insertion of the ligamentum patellae andX-ray often shows elevation and sometimesfragmentation of the tibial tub-ercle.

Treatment is rest from sport and sometimesa detachable splint behind the knee.


X-ray arthrogram ofa Baker’s cyst

Enlarged prepatellarbursa

Knee and Tibial Conditions

Genu varum Paget’s disease

Osgood–Schlatter’sdisease

Lateral meniscalcyst

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Cyst of the lateral meniscusThis is probably a degeneration of the lateralmeniscus following trauma rather than acongenital cyst. There is a tender cysticswelling, usually situated over the middleof the lateral meniscus.

Treatment used to be a total meniscectomybut local excision of the cyst alone isadequate.

Deformities of the kneePremature fusion of the medial femoral ortibial epiphysis will produce a genu varuswhile early fusion of the lateral femoral ortibial epiphysis will lead to a genu valgum(Chapter 7). Unbalanced paralysis of the kneeextensors or flexors may lead to flexiondeformity or genu recurvatum.

Degenerative changes in the medial andlateral joint of the knee may lead to narrowingof the joint and a small degree of genuvarum or valgum. Swelling of the knee inarthritis of any cause will lead to limita-tion of full extension and often flexion aswell.

Paget’s disease of the tibiaPaget’s disease is discussed in further detailin Chapter 11. There is usually bowing andthickening of the tibia and pathologicalfractures may occur. Osteogenic sarcoma isa rare complication. High-output cardiacfailure may occur in extensive Paget’sdisease, as the affected bone is highlyvascular.


Osteochondritis dissecansOsteochondritis dissecans usually involvesthe lateral side of the medial femoral condyleand occurs most commonly in adolescent boys.It usually results from trauma to the carti-lage with avascular changes in the underlyingbone. As a result an area of cartilage about5-10 mm in diameter, together with the un-derlying bone becomes avascular. This areamay detach and form a loose body in thejoint, which may catch in the joint and causeit to lock.

The usual treatment is to re-attach thepartially loose fragment with a recessed screwbefore it detaches, or excise it once it isfree in the joint.

Avascular necrosis of one or both femoralcondyles may occur after steroid therapy,such as in chronic asthma and renaltransplantation.

Treatment is excision of the avascularsegment and drilling and revascularising theremainder of the condyle. Occasionally totalknee replacement is required.

Meniscal and ligamentous injuriesThese may cause pain and swelling of theknee with instability and eventuallyosteoarthritis. Early arthroscopic excisionof detached fragments or open repair is oftenindicated.


Ankle and hind foot conditionsTendonitisTendonitis on the medial side of the ankleis usually due to inflammation of the tibialisposterior tendon sheath and on the lateralside to inflammation of the sheaths of theperoneal tendons.

Posteriorly the sheath of the tendocalcaneus may become inflamed by overuse ofthe tendon, by rubbing on the back of a shoeor by minor tears of the fibres of the tendonitself. Partial or complete rupture of thetendon may also occur.

Clinically there is tenderness and oftenswelling over the sheath of the relevanttendon and usually pain on stressing thetendon.

Treatment includes ‘resting the tendon’with an elevated heel on both shoes, theapplication of ice packs and elevation ofthe leg in the acute stage.In chronic tendon-itis deep heat, massage and sometimes injec-tions of hydrocortisone and local anaestheticinto the tendon sheath (not the tendon) maybe necessary. Occasionally incision of thetendon sheath may be required. Rupture ofthe plantaris tendon may also occur and leadto a sudden sharp pain in the mid calf. Thetreatment is the same as for a tendonitis ofthe tendo Achillis.

Painful heelPain under the heel is usually due to aplantar fasciitis, possibly following bruisingof the heel. It may be associated with acalcaneal spur seen on X-ray but this isoften unrelated to the pain. The heelsometimes becomes painful in chronic infec-tions, in rheumatoid arthritis and in otherinflammatory diseases.


X-ray appearanceof a calcaneal

spurTendinitis

Ankle and Hind FootConditions

X-ray appearance ofosteoarthritis

X-ray appearance ofrheumatoid arthritis

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On examination there is usually localisedtenderness under the point of the heel justin front of the calcaneal tuberosity.

Treatment involves treating the cause, ifobvious, as well as a heel pad to reduce thepressure. Occasionally physiotherapy or aninjection of hydrocortisone may be neces-sary. The differential diagnosis includes afracture of the calcaneus and osteomyelitis.

Longitudinal arch conditionsClawing or cavus of the foot may be associatedwith a neurological condition such aspoliomyelitis, spina bifida or Friedreich'sataxia. More commonly, however, it is idio-pathic. The treatment of cavus feet is thetreatment of the underlying cause andoccasionally operative correction of the de-formity.

Flattening of the longitudinal arch maybe idiopathic in young patients or secondaryto poor intrinsic muscles in elderly andoverweight patients. Spasmodic flat feet withperoneal muscle spasm occur occasionally,with a congenital calocalcaneo-navicular bar.

The treatment of painful flat feet due topoor intrinsic muscles is intrinsic reductionand adequate footwear as well as a longitudinalarch support. Spasmodic flat feet maysometimes require operative fusion of thesubtaloid joints.

Paralysed footParalysis of the foot, such as inpoliomyelitis or common peroneal or sciaticnerve damage, may lead to a ‘foot drop’ andalso to a fixed equinus of the ankle. Thismay necessitate elongation of the tendoAchillis followed by a below knee caliper oralternatively an arthrodesis of the subta-loid joints may be needed.


Ankle and Hind FootConditions

Pes planus Arch support

Pes cavus andclawed toes

Paralysed foot

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Spastic paralysis from an upper motorneurone lesion may also require a below kneecaliper, again sometimes preceded by elon-gation of the tendo Achillis.

Forefoot and toe conditionsClassification of forefoot conditions canbe divided into those affecting the plantarsurface, the dorsum and the sides of thefeet. Deformities of the toes are often as-sociated with these conditions.

Plantar surface of foot

Anterior metatarsalgiaThis is a painful area under the metatarsalheads, commonly the 2nd, 3rd, and 4th. It isusually due to weakening of the dynamicmuscular structure of the foot. It is oftenassociated with obesity, poor muscle tone,clawing of the toes and sometimes variousneurological conditions such aspoliomyelitis, leading to weakness of theintrinsic muscles.

Morton’s metatarsalgia (plantarneuroma)This is due to irritation followed byenlargement of a plantar digital nerve,usually between the 2nd and 3rd or 3rd and4th metatarsal heads. The patient complainsof pain in the forefoot, often at night whenthe feet are warm, and also while walking.The condition is often associated with ananterior metatarsalgia. During exam-inationthe main tender area can usually be pinpo-inted to lie between the metatarsal headsrather than under them as is the case inanterior metatarsalgia. The pain is usuallyworse on lateral compression of the forefootwhich compresses an enlarged neuroma betweenthe metatarsal heads. There may also be numb-ness between the toes supplied by the relevantcutaneous nerve.


Plantarfasciitis

Chroniclongitudinalarch strain

Morton'smetatarsalgia- plantarneuroma

Anteriormetatarsalgia2nd & 3rdmetatarsalheads

Forefoot and Toe Conditions

Plantar surface of the foot

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Treatment of both anterior metatarsalgiaand a digital neuroma is an anterior meta-tarsal pad or button placed just behind themetatarsal heads, plus good footwear andintensive muscle reduction. If this is notsuccessful the plantar neuroma should beexcised. In the case of anterior metatarsalgiacorrection of claw toes by subcutaneous te-notomy of the extensor tendons, transfer offlexor tendons to the extensor or arthrode-sis of the proximal interphalangeal jointsof the clawed toes may be carried out.Occasionally excision of a prominent 2nd or3rd metatarsal head may be neccessary.

Dorsum of foot and toes

March fractureThis condition is often missed. It is astress fracture, usually of the necks of the2nd and 3rd metatarsals, due to unaccustomedwalking, sometimes seen in new army recruits.The tender area, however, is over the dorsumrather than the plantar aspect of the meta-tarsals. X-rays show a fine crack in thebone which may be difficult to see at thetime of injury. Three to four weeks latercallus formation around the fracture con-firms the diagnosis, much to the embarass-ment of the treating doctor if the initialfracture was overlooked. The initialtreatment is rest followed by gradually in-creased weight-bearing, graded exercises andwalking.

Hallux valgusThis is a valgus deformity of the big toewhich may be combined with or due to a varusdeformity of the first metatarsal (metatarsusprimus varus). The cause is often acombination of a genetic predisposition to-gether with tight shoes. This causes a promi-nence of the first metatarsal head on the


Dorsum of the foot

Forefoot and Toe Conditions

1

Bunionette

Clawing of toes

"Hammer" toes"corn" over

proximal I.P.joint

Hallux valguswith "bunion"

Ganglion

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medial side of the foot which gradually leadsto an exostosis. Overlying this prominenceis a bursa which may become enlarged andinflamed to form a ‘bunion’.

Treatment initially should be a trial ofwider shoes and small pads to relieve thepressure over the prominent metatarsal headplus exercises for the intinsic muscles ofthe feet. Operative treatment can includeosteotomy of the first metatarsal to correctthe valgus deformity, intrinsic muscletransfer, excision of the proximal part ofthe proximal phalanx (Keller’s operation),or arthrodesis of the first metatarso-phalageal joint.

Hallus rigidusThis is due to osteoarthritis of the firstmetatarso-phalangeal joint. It is oftensecondary to trauma and leads to a fairlystiff joint which causes pain, particularlyon dorsiflexion. X-rays usually show a dim-inution of the joint space and osteophyteformation. If attempts at conservative treat-ment, including firm soled shoes, a rockersole or a metatarsal bar on the sole of theshoe fail to prevent excessive movement ofthe joint, an arthrodesis of the first met-atarsophalangeal joint may be necessary.

ExostosesAn exostosis of the head of the 5th metatar-sal is referred to as a bunionette. Thiscondition may be associated with valgus orother foot deformities and may require exci-sion if conservative measures fail. Otherexostoses, including those over the base ofthe 5th metatarsal, are treated with betterfootwear, pads, and occasionally operativeexcision.

Clawing of toesClawing or overriding of the 2nd to 5th toesis common and is often associated with otherfoot deformities, or weakness of the intrinsicmuscles of the feet. The 2nd toe may over-


ride a hallux valgus while the 5th toe mayoverride the 4th. In the latter case thismay be due to a symmetrical, congenitaldeformity. A neurological basis for clawingmust always be eliminated, such as polio-myelitis, peripheral neuritis or spina bifida(especially if associated with a cavus footand sensory deficit or motor weakness). Manycases, however, occur in elderly, over-weight women with poor intrinsic muscles.

Flexed proximal and distal interphalangealjoints may cause pressure and tenderness overthe end of the flexed toes which press onthe shoe or ground. Correction of thiscondition includes appropriate footwear,intrinsic muscle reduction, ‘corn’ pads andoccasionally operation, as discussed underanterior metatarsalgia. Other foot condi-tions, including exostoses, may occur else-where due to rubbing of shoes.

GanglionThis is a cystic swelling filled with glairyfluid and associated with a joint. Excisionof an exostosis or ganglion may be necessaryif conservative measures fail and if thecondition is symptomatic.

Miscellaneous conditionsThe differential diagnosis of foot

conditions includes congenital deformitiessuch as talipes equino varus and spasmodicflat feet (often associated with a talocal-caneonavicular bar), tumours, trauma, in-fections and arthritis. All these conditions,as well as osteoarthritis, rheumatoidarthritis, gout and paralytic conditions arediscussed elsewhere in this book.


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Chapter 14 Lower Limb Conditions - Boston Brace