THE IPK - The Podiatry Institute

LESSER METATARSALTECHNIQL]ES FOR RELIEF OFTHE IPKStepben J. Miller, DPI,IINTRODUCTIONLesser metatarsal osteotomies have very specificindications, and are used primarily to alleviatefocal metatarsalgia secondary to intractable plantarkeratoses (IPK's), which are unresponsive toconseruative care. Frequently the metatarsal headis plantarflexed, as evidenced on an axialsesamoid x-ray t however, this is not necessarilythe case in the presence of a thick, sensitive, andnucleated IPK. The goal of surgery is to relievefocal plantar pressure by elevating the metatarsalhead.Metatarsal elevating osteotomies are performedin the metaphyseal section of bone,where there is a rich blood supply and amplecancellous bone, both of which augment healing.Surgical planning requires attention to the directionand placement of the osteotomy, as well asits apex or hinge.Execution of the osteotomy requires the delicateuse of a power saw. The instrument mustproduce high-torque with little cross-vibration.One must also use a thin, sharp, saw blade tomake the cut as exact as possible. The amount ofbone removed depends on the relativeprominence of the metatarsal head and thelength of the lever arm. Reciprocal planing willhelp to make an exact cut, while keeping thehinge intact. Frequent irrigation with cool salineduring the cutting will help prevent thermalosteonecrosis.LESSER METATARSAI OSTEOTOMIESThere are five osteotomy techniques currently recommendedfor the relief of lesser metatarsalgiasecondary to an intractable plantar keratosis.These will be presented individually with clinicalillustrations.Plantar CondylectomyThis procedure is indicated in o1der, more sedentarypatients, and when osteoporosis prevents utilizaltonof an osteotomy which requires bonehealing. It can also be used when previousmetatarsal elevation procedures have failed. Complicationsinclude flexor pad adhesions and "floatingtoes".Figure 1. Orientation of plantar cond,vlectomy on a lateral vie$B4

Figure 2. Resection of plantar condl,leFigure l. An osteotome or po\\'er sar\,- may be utilized for theosteotom\r.Figure 4. Removal of resected plantar condyleFigure 5. Mechanical changes following resection of plantarcondyles leading to digital instability.B5

Distal V-OsteotomyA distal, sagittal plane, "V" osteotomy allows themetatarsal head to be maneuvered either dorsaliyor plantarly. Stable fixation is recommended, asmotion at the osteotomy site can lead to callusformation and delayed healing. In addition, transferlesions are potential complications. The techniquecan also be adapted to shorten or lengthena lesser metatarsal.DistalphalanxMiddlephalanxExtensorwingExtensorslingMedial and lateralCentral slipMetatarsalLumbricalisTransversemetatarsalligamentJExtensordigitorumbrevisExtensordigitorumbrevislnterosseimuscleFlgure 6. Incisional approach to the distal lesser metatarsalosteotom,v,Figure 7. Exposure of the metatarsal head bet$,-een the long andshort extensor tenclons.Figure !. The metatarsal head is elevated and impacted on themetatarsal shaft.Flgure 8. The oste

a\[[$oFigure 10. The capital fragment is repositioned dorsally.Plantarflexory orDorsiflexory "V"Osteotomy0.045" K-Wire-Figure L1. The "V" osteotomy is stabilized with a 0,045" K-wire, andadvanced into subchondral bone.0.045",K-WireOsteotomyFigure 12. The capital fragment can also be displaced and stabilizedin a more plantar position,Figure lf. The "V" osteotomy can be utilized to shorten a lessermetatarsal by resecting a wedge of bone.87

Distal Oblique OsteotomyThis osteotomy allows for a controliecl elevationof the metatarsal head in conjunction with rigidinternal fixation.Ftgure 14. Angulating the osteotomy for maximum stabilityFigure 15. Screq- fixation is utilized to stabilize the osteotoml'.Proximal Oblique OsteotomyThis osteotomy avoids periarticttlar dissection atthe metatarsophzrlangeal joint 1evel, and alsoallows for rigid internal fixation.Ftgure 16. The proximal osteotomy requires less bone removal dueto the lever arm eff'ect.Figure 17. The obliquiry of the osteotomy allon's for rigid intedragmentaqrcomplessive fixation,8B

OsteoarthrotomyWhen the goal of surgery is to mobilize a lessermetatarsal to relieve pressllre at the head, thearticular base of the metatarsal can be removed.This technique does not rely on bone healing forits success. It cannot be used to relieve deepIPK's or severely plantarflexed lesser metatarsals.Figure 1!. Postoperative oblique x-ray followinEaosteoarthrotomy of the metatarsal base,Figure 18. An osteoarthrotomy (pictured at the base of the secondmetatarsal) removes the base of t1're lesser metatarsal at its tarsomctatarsalarticulation.Postoperative Weight BearingThe principles of rigid internal fixation, as well asthe conditions necessary for bone healing (eg.immobilization), indicate that non-weight bearingfor six weeks postoperatively provides the mostoptimal environment for healing. However, judiciousapplication of technical factor may allow forweight bearing while the bone heals. These factorsinclude: osteotomy placement, direction ofthe cut and preservation of the hinge, andmethod of fixation. The final decision should bebased upon the judgement and experience of thesurgeon.Excision of the Plantar LesionThe decision to excise the plantar skin lesionclepends on the lesion's characteristics. If thelesion is somewhat diffuse but well-localtzedunder a metatarsal head, then an osteotomy aloneshould result in its resolution.If the lesion is thick, nucleated and extremelypainful, then an osteotomy alone is less likelyto provide sufficient relief. To test for this, onecan apply lateral compression over the lesion. Ifthis causes exquisite pain, then cutaneous nelveentrapment is likely, and the lesion must be extricatedfor complete resolution of symptoms.When a broad diffuse tyloma is observedbeneath several metatarsal heads (2, 3, and 4'),one should become suspicious of either a gastrocnemiusor triceps equinus. Metatarsal surgeryalone, in the face of such a deforming force, iscontraindicated and the equinus must beaddressed.The plantar lesion can be excised using adouble-elliptical incision technique. The ellipseshould be planned and marked prior to makingthe incision. The ellipse should be 3 to 4 times aslong as it is wide. A vertical mattress type sutureis recommended.In order to achieve minimal scar formationfollowing the excision of a plantar lesion, thepatient must be non-weight bearing for threeweeks. The sutures are alternately removed overthe next week as the patient begins gradualweight-bearing.B9

Flgure 2O. Planing the elliptical incisionsFigure 21. Suturing of the plantar wound under minimal tensionBIBLIOGRAPHYFiglute 22. Appearance of the plantar scar three months postexcision.Banel PF: Lesser metatarsal osteotomy. J Am Padidttj-,4ssoc 671 3i8-360, 1977.Bayliss NC, Klenerman L; Avascular necrosis of lesser metatarsall-reads following forefoot sur€]ery. Foat Ankle 101 724-128, 1989.DuVries HL: New approaches to the treatment of intractable verrucaplantaris (plantar wafi). .J,LM4 15211202-7203, 7953.DtrVries HL. Mann RA: Intractabie plantar keratosis. Ortbetp C'linNor.tb Am 4,67-73. 1973.Graver H: Angular metatarsal osteotomyi A Preliminary Report. J AmPodiatry Assoc 63:95-98, 19t3.Hatcher Rlvl. Guller 'WL, Weil LS: Intractable plantar keratoses: Areview of surgical corrections. J Am Podidtry-,4-s-soc 68: 377 386,1978.Heilal B: Nletatarsal osteotomy for metatarsalgi^. J Bone Joint Sltrg57It: 787-792.1977.Jacoby RP: V-Osteoplasty for correction of intractable plantar keratosts. J F.)at Surg 1,2:8-70, 79f 3.Kus,-acla GT, Dockery GL, Schuberth JM: The resistant, painful, plantarlesion: A surgical Approach. /Fo ot Surg 22: 29-32, 1983.le\renten EO, Pearson S\X': Distal metatarsal osteotomy for intractableplantar keratoses. Foot Ankle. l0: 217 521,,1,990.Loretz L, Gerbert J, N{oss K: Significance of the suspensory ancl collateralligaments in lesser metatal:sal neck surgery, J Foot Surg2J:723 728,1984.Pedowitz 1i({: Distal oblique osteoton}r for intractable plantar keratosisof the middle three metatarsals. Fctot Ankle 9:7-9, 1988.Rr"rtherforcl RLr lv{etatarsal shortening for the relief of symptomaticplantar keratoses. J Foot Surg 9: 73-76. 1970.Schlamberg EL, Lorenz X4-A: A dorsal wedge V Osteotomy for painfttlplantar callosities. Fctot Ankle 4:30-32, 1983.Schneitzer DA, Len,H, SkukenJ, MorganJ: Central meiatarsal shorteningfollowing osteotomy and its significance. ,/ Am PodiatryAssocT2:6-10, 1982.Valley BA. Reese H$fl: Guiclelines for restructuring the metatarsalparabola with tl-re shortening osteotomy. J Am Podian'ic Med,,lssoc 81: 106-113, 1991.\Winston IG. Raniinson J, tsroughton NS: Treatment of metatalsalgiab1, s1i,ltrr* distal metatarsal osteotomy. l-oot Ankle.09: 1-6, 1988.Woolf \XrH: Eradication of the problem plantar hematoma. J Am Poclidtt!AssocTlt 163-167, 1981.Young DE, Hugaf D\W: Evaluation of the V-osteotomy as a procedureto alleviate intractable plantar keratoma. J Foot Surg 19: 187.1980.90