JUNE/JULY 2011 | PODIATRY MANAGEMENT | 1www.podiatrym.com

Editor’s Note: This is the secondin an occasional series in which newData Trace books are introduced toPM readers via selected excerpts. DataTrace Publishing Company has been aleading publisher in the podiatry fieldsince 1989.

The following chapter has beenexcerpted:

Chapter 5Digital and Lesser MTPJ ImplantsJoel R. Clark, DPM, FACFAS

Digital Implants

Introduction:Digital implants have been avail-

able for more than 25 years. Theyhave been used in place of digitalarthroplasties or arthrodesis proce-dures of the proximal interphalangealjoint primarily in the second digit, buton occasion in digits three and four.We have also used an implant in thefifth digit for stability in lieu of a syn-dactylism or for a “floppy digit.” Thischapter will discuss the following dig-ital implants being used by thesurgery department faculty: the WeilDigital Implant™ by Wright, the Sgarla-to Ship Implant™, the Futura FlexibleDigital Implant™ and the InterPhlexImplant Spacer™ by OsteoMed.

The decision to use a digital im-plant rather than perform a traditional

arthroplasty or arthrodesis is often thesurgeon’s preference in the treatmentof a semi rigid or rigid digital deformi-

ty. All of the above implants, with theexception of the Futura Flexible Digi-

Dr. Gerbert’s new book takesa comprehensive look at

the pathomechanics of these pathologies.

Lesser ForefootSurgery

THEDATA TRACE AUTHORS’ SERIES

Continued on page 2

Lesser Forefoot Surgery

Apremier podiatric surgery textbook, LesserForefoot Surgery, edited by Dr. Joshua Ger-

bert of California School of Podiatric Medicineat Samuel Merritt College with contributionsfrom Drs. Burns, Clark and Jenkins, presents acomprehensive look at the pathomechanics ofthe most common lesser forefoot pathologies.

As Dr. Gerbert explains, “This textbook is acompilation of 30 years of experiences by members of the SurgeryDepartment at the California School of Podiatric Medicine in evaluat-ing and determining the most effective surgical therapies for the morecommon problems of the lesser forefoot. While there are a few text-books that cover certain aspects of this subject, none provided an in-depth perspective.”

Lesser Forefoot Surgery guides the podiatric student, podiatric resi-dent or practicing podiatrist through surgical correction of pathologyinvolving the lesser forefoot. Chapters address surgical procedures,deformities, clinical assessments, management options, recommend-ed post operative management and inherent complications associatedwith the procedures. Over 300 illustrations, including clinical pho-tographs, radiographs, magnetic resonance images, and detailed linedrawings compliment each discussion and help to provide a full un-derstanding of the range of pathologies addressed.

For more information about Lesser Forefoot Surgery or to orderyour copy today please call 1-800-342-0454 or visitDataTrace.com.•

Dr. Gerbert

www.podiatrym.com

THEDATA TRACE AUTHORS’ SERIESLESSER FOREFOOT SURGERY

2 | JUNE/JULY 2011 | PODIATRY MANAGEMENT

tal Implant™, are solid spacers with nohinge component. Motion occurs be-tween the implant body and flexiblestems within the modularly canal ofthe phalanx. We have observed thatall provide equal stability in the trans-verse plane but that the hinged sys-tem by Futura does provide slightlymore sagittal plane flexibility at thePIPJ.

Advantages over PIPJ arthroplasty are:1) More intrinsic stability.2) Maintains the length of the

digit.3) Better toe purchase.

Advantages over PIPJ arthrodesis are:1) Immediate postoperative

propulsive ambulation and return toregular foot gear in two to threeweeks.

2) No need for internal or externalfixation devices.

3) Maintain proximal interpha-langeal joint motion.

4) Maintains the length of thedigit.

Disadvantages:1) Possible reaction to the implant

material.2) Need adequate bone stock to

receive the implant stem.3) Reoccurrence of deformity.4) Chronic digital edema.

Clinical Evaluation:The same general criteria is used

for selection of a digital implant as fora digital arthroplasty as discussed inChapter 3 and an arthrodesis as dis-cussed in Chapter 4.

Procedure:A dorsal linear incision is made

centered over the proximal inter-phangeal joint of the digit. If a dor-sal hyperkeratotic lesion is presentit can be excised by two semiellipti-cal incisions (Fig. 5-1).

Dissection is carried down tothe level of the extensor tendonwhich is incised transversely justproximal to the joint, or dividedlongitudinally and retracted to ei-ther side of the joint. Using powerequipment to avoid possible mi-crofractures to the phalangeal shaft,

the head of the proximal is then re-sected. We typically do not resectany bone from the base of the in-termediate phalanx to serve as abetter buttress against the implant(Fig. 5-2).

Therefore, whatever shorteningis required should be taken fromthe proximal phalanx. The digitshould now be evaluated to assurethat no remaining contracturesexist at the metatarsal phalangealjoint and if present refer to Chapter6 for correction of the deformity.Holes are fashioned into themedullary canal of the proximalphalanx and through the articular car-tilage into the base of the intermedi-ate phalanx. The drills and broachesspecific to the implant brand selected

can be used to create the holes. Caremust be taken to avoid fracture orbraking through the cortex of eitherbone. Once the holes are created atrial sizer is used to select the appro-priate implant size. The implantshould rest just beyond the corticalmargins of both phalanxes if possibleand with the foot loaded, maintainthe toe in proper alignment in allthree planes. Any additional proce-dures, such as flexor tendon transfers,should be performed prior to insertingthe actual implant and the toe reeval-uated with the sizer to assure proper

digital alignment and reduction of alldeformities. Once satisfactory correc-tion is achieved, the wound is flushedcopiously and the actual implant is in-

serted. It should be transferred fromthe package into a saline or lactatedringer’s solution to reduce staticcharges on the implant material andinserted in the digit using atraumaticforceps. The extensor tendon is re-paired and the skin approximated.The surgical site is dressed in thesame manner as one would do for anarthroplasty.

Post Operative Management:The patient is placed in a post op-

erative shoe and allowed to ambulate.Bandages are changed at weekly in-tervals and sutures are removed at14 days. X-rays are taken within thefirst postoperative week to accessthe implant position. The patient isallowed to return to regular shoegear and activities as soon as possi-ble following suture removal.

Inherent Complications:1) Dactylitis of the involved digit

which will usually respond to a com-pressive dressing and/or physicaltherapy. If the condition persists, it

The decision to use a digital implant rather thanperform a traditional arthroplasty or arthrodesis

is often the surgeon’s preference in thetreatment of a semi rigid or rigid digital deformity.

Continued on page 3Figure 5-1: Clinical photograph of two semielliptical inci-sions centered over the PIPJ.

Figure 5-2: Clinical photograph of resection of thehead of the proximal phalanx.Typically, no bone is re-moved from the base of the intermediate phalanx.

THEDATA TRACE AUTHORS’ SERIESLESSER FOREFOOT SURGERY

may require an acetate steroid injec-tion after anesthetizing the digit.

2) Excessive fibrosis (encap-sulization) at the joint. This generallywill reduce with time but may requireremoval of the implant and leaving

the toe with an arthroplasty.3) Implant failure has not been a

complication we have seen with digi-tal implants. However, failure of thephalanx to support the implant stemhas occurred when the cortex of theproximal phalanx has been damagedwhile reaming the canal for the im-plant stem. This may require removalof the implant and leaving the toe

with an arthroplasty or performing anarthrodesis.

4) Reoccurrence of the deformity.This generally is a failure to properlyreduce all associated deformities atthe time of the original procedure.

Once those deformities have beenidentified, they should be correctedand the implant should not typicallyneed to be removed.

5) Bone resorption at the im-plant/bone interface which is usuallythe result of insufficient bone removedprior to implant insertion. If symp-tomatic, the implant can be removed,more bone resected and the implant

reinserted or left as an arthroplasty.

Clinical Pearls:1) Make sure that all associated

deformities of the metatarsal pha-langeal joint and associated tendoncontractures have been properly iden-tified and corrected.

2) Select an implant size that isappropriate to that specific toe. Toolarge an implant will increase thebulk around the site of insertion.

3) Have adequate bone stock pre-sent of the involved digit.

4) Allow a few millimeters of pis-toning of the implant to occur afterinsertion.

5) Use a compressive taping ofthe digit following suture removal forone to two weeks to reduce postoper-ative edema.

6) Be sure the patient understandsthat an artificial joint spacer will beused and that it may require removalin the future. PM

Be sure the patient understands thatan artificial joint spacer will be used andthat it may require removal in the future.

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