metatarsat osteotomy for the correction of metatarsus adductus

More documents

Recommendations

Info

$closure of deep fascia in ankle fracture surgery - The Podiatry Institute$

tarsometatarsal joint, as evidenced by the disparity in themedial and lateral foot borders (Fig. 1). The presentationof a convex lateral border and a concave medial borderwill be evident but depends on the degree of compensation.ln the uncompensated foot the convexity of theIateral border will be most marked with the styloid processof the fifth metatarsal very prominent. The medialarch may exhibit more height than expected for a childin his/her particular age group. ln contrast the totallycompensated deformity may reveal only a mild amountof convexity to the lateral border, a rather low or evenflattened medial arch and even some abduction of thedigits. Many authors have observed the separation of thehallux and the second digit and have suggested that thisseems more prevalent in the uncompensated and partiallycompensated foot types.During a thorough biomechanical evaluation, determinationof the presence of sagittal and frontal planeabnormalities must be made. This will affect the surgicalstrategy. The presence of a gastrocnemius orgastrocnemius-soleus equinus must be addressed toinsure the success of a metatarsus adductus repair.Evaluation of subtalar joint motion is also of greatimportance. Finally, the presence of an uncompensatedrearfoot varus if present must also be addressed.The forefoot should be examined in the standardfashion, the subtalar joint should be in its neutral position,the midtarsal joint should be locked. This willpermit an accurate appraisal of the metatarsal alignmentin all three planes. If a true transverse plane deformityexists, the metatarsal heads will all be aligned on thesame transverse plane. Any difference in elevation betweenmetatarsals can be compensated at the time ofsurgery. Careful preoperative planning will help to ensurea successful outcome. A gross frontal plane deformitymay exist in the form of a rigid forefoot varus. Actualdetermination of inversion of the metatarsals is notclinically possible.A common radiographic finding that is difficult toquantify clinically is the degree of adduction of eachmetatarsal. There may be an actual increase in the degreeof adduction of each metatarsal from lateral to medialwith the greatest amount being present in the firstmetatarsal. This can be considered as the domino effect.Another parameter to consider is the degree of flexibilitypresent in the deformity. A rigid metatarsus adductusdeformity will require more aggressive treatmentthan a flexible deformity. Postoperative casting andsplinting will be of assistance in reducing the adductusin the flexible deformity.Fig. 't. Clinical representation of resistant metatarsus adductus.Consideration of the presence of functional halluxlimitus must be made. Functional hallux Iimitus is theinability of the great toe to extend over the first metatarsalwhen the heel is lifting off the ground. This createsa sagittal plane motion blockade at the first metatarsophalangealjoint which must be compensated for atthe level of the midtarsal joint or ankle joint. The endresult is an accentuation of the deformity through anadductory twist at heeloff. This can be corrected at thetime of surgery by plantarflexing the first metatarsal andincreasing the declination and stability of the first ray.RADIOGRAPHIC EVATUATIONSThe diagnosis of metatarsus adductus is generallymade by clinical evaluation. Radiographic studies do contributeto determining the extent of the deformity as wellas providing greater insight to the osseous relationships.Full weight-bearing dorsoplantar and lateral views areperformed and used not only for determination ofangular relationships but to evaluate the osseous maturityof the foot (Fig. 2).The dorsoplantar view is of primary importance fordetermination of the metatarsus adductus angle. Thereare two methods currently used. The first depends ondefining the longitudinal axis of the lesser tarsus. Thisis accomplished by plotting a series of points beginningwith the medial most aspect of the first metatarsalcuneiform joint followed by the medial most aspect ofthe talonavicular joint, the lateral most aspect of the fifthmetatarsal cuboid joint, lastly the lateral most aspect ofthe calcaneocuboid joint. Two lines are then drawn, oneconnecting the medial points and one connecting thelateral points. Each of these lines is then bisected anda third line is drawn connecting the bisect points acrossthe midfoot. A fourth line is then constructed perpen-243
Fig. 2. Preoperative radiographs, A & B, of symptomatic metatarsusadductus.dicular to the third Iine and represents the longitudinalaxis of the midfoot.The bisection of the second metatarsal will serve as thelongitudinal axis of the metatarsals. The angular relationshipbetween the longitudinal axis of the lesser tarsusand the longitudinal axis of the second metatarsal willrepresent the metatarsus adductus angle (Fig. 3).A second method of defining the metatarsus adductusangle has been proposed. In this method the longitudinalaxis of the metatarsals remains the longitudinal bisectorof the second metatarsal. The angle is def ined utilizingthe longitudinal bisector of the second cuneiform(Fig. a). The authors found that their method resulted inan increase of three degrees over an accepted normalmeasurement of twenty-one degrees.There is much controversy over a strict definition ofmetatarsus adductus. Some authors define pathologicalmetatarsus adductus as being greater than twenty-onedegrees. Others have liberally defined normal as ten totwenty degrees. The faculty and staff at the Podiatrylnstitute use the following guidelines for definingmetatarsus adductus.Classification of Metatarsus AdductusNormalMitdModerateSevere< 15 degrees16-25 degrees26-35 degrees> 35 degreesThese numbers are guidelines and are to be used inquantifying the deformity. Keep in mind the irnportanceo{ angle and base of gait radiographs. The patient mustbe positioned carefully because supination of the subtalarjoint can result in an apparent increase in theamount of metatarsus adductus.As the child matures the appearance of the bases ofthe metatarsals will also change. Recall that the epiphysisof the first metatarsal is at its base and f inal ossificationdoes not take place until 16 to 20 years of age and canvary substantially. The epiphyses of the lesser metatarsalsare at the neck. They close at approximately the sameage. In early childhood the bases are rather round inappearance. As the child reaches adolescence the baseand neck will square themselves off and resemble adultmetatarsals. The majority of procedures will be performedat the proximal one-third to one-fourth of themetatarsal.OSSEOUS SURGERYMetatarsal osteotomy has been advocated for the correctionof metatarsus adductus alone or in combinationwith other procedures. Berman and Gartland introducedosteotomies of all five metatarsals for the correction ofmetatarsus adductus in 1971. Since that time the procedurehas undergone several refinements. lt serves asthe foundation for the correction of resistant metatarsusadductus in children age six to eight or older.The original Berman and Cartland procedure useddome-shaped osteotomies of the base of the metatarsals.ln severe cases the removal of laterally based wedges ofbone from the metatarsal base facilitated the correction.Initially the metatarsal osteotomies were not fixated, buteventually unthreaded Steinmann pins were used for fixationof the first and fifth metatarsals.244
Page 1: METATARSAT OSTEOTOMY FOR THE CORREC
Page 5 and 6: Fig.5. Preoperative and postoperati
Page 7 and 8: Fig. 9. Diagrammatic representation
Page 9: pression fixation resulting in prim

metatarsat osteotomy for the correction of metatarsus adductus

Create successful ePaper yourself

Delete template?

Save as template?