CHAPTER l7COMPLICATIONS ASSOCIATED WITFI SURGICALTREATMENT OF PLANTAR FIBROMATOSIS

Roberl Goecke4 DPM

INTRODUCTION

Plantar fibromatosis is defined as a rare benign fibro-proliferative disorder involving the plantar aponeurosis(fascia). Although benign, the condition is locallyaggressive. Tieatment is indicated for pain, feeling of themass in the foot, shoe-fit problems and functional gaitabnormalities. Symptomatic lesions that require surgicalintervention have been historically addressed by localexcision, wide excision, or complete (subtotal) piantarfasciectomy.' There is a high recurrence rate after localsurgical excision. Recurrence rates have ranged from 60-100o/o with simple excision.2 fleatment of this conditioncan be problematic due to its propensiry for complicationsand recurrence.t'" Several possible complications associatedwith surgical excision including recurrence, wound healingproblems, scarring, and nerve injury create a challenge tothe foot and ankle surgeon. Various attempts to lessenrecurrence have included use of Marlex mesh,t free dermalfat grafts," and split thickness skin grafting,' whichunfortunately have not been universally successful. Mostnow agree that subtotal fasciectomy decreases the risk ofrecurrence in primary and recurrent lesions.2'3'7''1 The idealoutcome would preserve anatomic structure, have minimalscarring and maintain a supple functional foot for weightbearing. This article will review the methods of treatmentthat decrease the potential complications associated withrecurrence, nerve entrapment, and wound healing.

REVIE\T

Plantar fibromatosis is defined as a benign process offibrous proliferation that replaces the normal cellulararchitecture of the plantar fascia (Figure 1). It is aisoknown as Ledderhose's disease.' It tends to have a benignclinical behavior with an insidious onset and a slowlyprogressive course. It can manifest as either multiplenodules or a solitary nodule (lesion). The lesions canoccur at any age including childhood, although mostreports describe the 4th to 6th decade of life as the mostcommon time period. The lesions are more common inCaucasian male patients.6''

Fibromatoses are divided into 2 subrypes dependingon their location (whether they involve superficial or deeptissues). Deep fibromatosis (desmoid tumors) includeintra-abdominal rypes, abdominal, and extra-abdominalrypes. The superficial lesions include palmar fibromatosis(Dupuytren contracture), plantar fibromatosis(Ledderhose's disease), penile fibromatosis (Peyronie'sdisease), and knuckle pads. Manv times plantar fibro-matosis coexists with other fibrous diseases such asDupuytrent contracture and Peyronie's disease.'3 Theselesions usually occur in regions of stress. The etiology ofplantar fibromatosis is unknown. There is researchdocumenting familial tendencies. Fetsch et al questioned25 pre-adolescent and adolescent fibromatosis patientsand identified that 11 had a family history of palmar orplantar fibromatosis." A simple mutation usuallydescribed as primary trisomies of chromosomes 7 and 8in superficial fibromatosis have been described. Recentlya case ofclonal reciprocal translocation identified in a caseof plantar fibromatosis may represent a early neoplastic-relevant mutation.'3 Other associated causes describedinclude trauma, neuropathy, gout, naturopathies,alcoholism, metabolic disorders, infection, geneticdiseases, and autoimmune diseases.ta

Ledderhose was the first to describe the histologicfeatures of the disease in 1897.n Plantar fibromatoses are

Figure 1. Clinical appearmce of multiple, recurrent plmtm flbromatoses affectingthe medial abductor fmcia ald the distal medial extension of the plantar fmcia.

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Figurc 2A. Surgical arppearance olr plantar tibromatosis afier surgical exposLrre. Figure 2B. P;rthology specimen of an excised plantar fibromatosis

Figure 3A. Magnetic resonance imaging of recurrent plantar fibromatosis.

usually irregular, rubbery to firm, off-white fibrous tissuemassesl5 (Figure 2). Microscopically, plantar fibromatoseshave been shown to be very similar to palmarfibromatoses. Fibromatosis have been classified into 3phases: proliferative, active (evaluative), and maturarion(residual).'o In the first phase fibroblasts proliferate in anintracellular substance, resulting in the formation of thenodule. In the active phase the nodule further develops.The cells in this phase have the characteristics offibroblasts and of smooth muscle (myofibroblasts).Finally in the third phase, there is a prevalence of collagenfibers in an abundant matrix with scattered fibroblastsand inflammatory cells. r3 rt

Microscopic evaluation usually shows uniform,spindle shaped multinodular fibroblast cells in aninterwoven pattern with perivascular inflammatory cells,which are peripherally arranged including lymphocytes,neutrophils and multinucleated giant cells. Cellularatypical is usually mild." These lesions all have an

Figure 3B. Magnetic rcsonance imaging of recurrent plantar fibromatosis.

infiltrative growth pattern and involve dense regularconnective tissue. Within this tissue there is also aproliferation of spindled myofibroblasts with a tendency toform intersecting fascicles. The evidence of a cytoskeletonand an extra cellular filamentous system suppofts theability for the myofibroblasts to generate and exert theintracellular forces that contribute to the contraction oftheaponeurosis. Fiexion contracture of the toes associated withplantar fibromatosis has been described although this isusually more common in the hands (Dupuytren'scontracture) than the feet.''''t Plantar fibromatosis canusually be easily recognized by those who specialize in thelower extremity although with any soft tissue mass it iscritical to exclude a potendal malignancy with appropriatediagnostic modalities including radiographs, ultrasound,and magnetic lesonance imaging (MRI). Radiographsrarely will reveal any abnormality other than some softtissue fullness, edema and increased density. Thesonographic appearance of the plantar fascia in plantar

CHAPTER I7 9t

Figure 4. Z-l1ap skin incision.

fibromatosis is most commonly described as hypoechoic,weli defined, without acousric enhancement or intrinsicvasculariqr.l' More commonly MRIs are udlized ro confirmthe clinical diagnosis. MRI characterisrics in plantarfibromatosis show a relativeiy low signal intensiry on bothT1 and T2 images compared with sarcomas that rendto have moderate increase signal in T1 and increased T2signal (Figure 3).'0 "

TREAIMENT/RESULIS

The decision to treat these lesions depends on the size andlocation of the lesion and patient sympromatology. Oncesurgical intervention is planned, it is critical to consider theplantar neurovascular anatomy to decrease the potentialcomplications associated with plantar fasciectomy. As ageneral rule the deep arterial flow into the foot follows aproximal to distal orientation into the distal extensions ofthe medial and lateral plantar arteries. The blood flowthrough the plantar skin within the subdermal plexusfollows a different orientation. The vessels reach the skinthrough a perforating system from the larger lateral plantarartery and the smaller medial plantar artery deep in rhecentral compartment of the foot. The perforating vesselsmove from deep to superficial on either side of the cenrralband of the plantar fascia through the medial and lateralplantar sulci. Once the blood moves through theperforating arteries to the skin, the blood flow then changesto a more transverse orientation toward the central aspectofthe arch. Venous flow is exacdy opposite, heading fromcentral to medial and lateral.

Skin viability is critical to the successful woundhealing in any plantar arch incision. Successful incisionplacement will consider both the superficial and deeparterial flow. Incision placement that considers the skin

Fieure 5. Wouncl healing problems can occur with necrosis :rnd dehiscence espe-ciallv in revisional cases with cxtensivc involvcment to skin and deep structures.

arterial flow is critical to avoid complications associatedwith plantar fasciectomy. Longitudinal parallel incisionsmust be avoided. Large flaps that may cross blood flowfrom the opposite direction may lead to apical necrosis." ta

Subtotal plantar fasciectomy requires preciseanatomic dissection. It is critical to maintain viable skinmargins with enough exposure to ensure adequate visual-ization of the entire exrent of the plantar fascia including anadequate excision margin as well as identification andavoidance of the neurovascular structures. Therefore, skinincision placement is an important consideration. Ifpossible, the incision should be centrally located in the archproviding access for the transverse flow of blood towardthe center of the foot but still allowing for adequatevisualization of the underlying mass.

Historically, Curtin proposed an incision that curvedfrom the plantar medial first metatarsal in a lazy S fashionin a medial to lateral direction to the iateral weight bearingsurface then ending back medially just distal to thecalcaneal tuberosity.' This approach crosses the midlineand places a large portion of the incision directly over thesuperficial branch of the medial plantar nerve increases thepotential for postoperative neuroma. Another incisionalapproach utilizes a longitudinal incision, which providesless disruption to the blood supply but is perpendicular toreiaxed skin tension lines. Others have tried to followrela-xed skin tension lines more by modi!.ing surgicalapproaches with transverse, lazy S or Z-flaps (Figure 4).Maintaining a wide base with an adequate apical angle iscritical with the use of skin flaps. Gentle handling of theapex of the skin flaps is critical. The author will utilizesuture to retract the skin flaps to avoid apical necrosis. Theauthor prefers the Z-flap to provide adequate exposurewhile maintaining transverse blood flow into the flaps. Allincisions have a risk of wound healing complications.

92 CHAPTER 17

Figure 6. Anatomic appearance after excision of plantar fibromatosis. Note theabductor hallucis, flexor hallucis Iongus, medial plantar nerue and the flexordigitorun brevis.

Necrosis and dehiscence are probiems that can occur. Manytimes recurrent lesions with multiple nodules andepidermal adhesions are prone to these problems (Figure 5).

Avoiding postoperative nerve entrapment andassociated chronic pain is probably the most importantsurgical consideration. The medial plantar neurovascularbundle tends to run between the flexor digitorum brevisand abductor hallucis muscle belly (Figure 6). Often thefibromatosis may impinge on this neurovascular bundle."Dissection of plantar fibromatoses requires anatomicprecision from the underlying muscle/tendon,surrounding fat, neurovascular tissue and overlying skinare essential. The fibromatosis should be removedwithout injury to the surrounding tissue, excising onlythe fascia and associated fibrosis tissue. Entrapment of theplantar nerves with postoperative cutaneous neuromaformation is not uncommon due to the close proximiry ofthe fibromatosis to the neurovascular structures.r'e''1\Tapner et al described 2 severe cases of intractable painout ofa series of 12 patients after revisional cases due toneuroma formation that have contemplated amputation.'Sammarco had 1 case of 21 who developed a plantarcutaneous neuroma.tt Aluisio et al reported 2 cases oflateral plantar nerve laceration and 1 case of medialplantar nerve entrapment.e

One must avoid adhesion of the musculotendinousstructures including the flexor hallucis longus tendon andavoid direct scarring of the epithelial layer to deeperstructures. Sammarco et al described a staging system(I-IV), which depends on the extent of plantar fasciainvolvement, the presence of skin adherence, and thedepth of the tumor. Stage I was described as focal diseaseisolated to a small area on either the medial or centralband of the plantar fascia with no adherence to the skin

or deep extension to the flexor sheath. Stage II is alsofree from skin and deep flexor sheath extension althoughit is described as multifocal. Stage III lesions are alsomultifocal but exhibit either deep extension to the flexorsheath or adherence to skin. Finally, Stage IV lesions aremultifocal, have extension to the flexor sheath and alsoare adhered to the skin. The stage of the tumor has beenshown to correlate well with postoperative woundhealing, skin necrosis and recurrence. In 1 1 ofthe 2l {eet(52o/o) presented by Sammarco wound healing tooklonger than 4 weeks and 4 of them required splitthickness skin grafting. T.. of the eleven patientswith wound complications had either a Stage III or StageIV lesion."

The most-recognized complication is the likelihoodof recurrence. Several authors have described decreasedrecurrence rates with subtotal plantar fasciectomy inrevisional and in primary cases of plantar fibromatosis.z'3'7-e'11Durr et al proposed a decreased chance of recurrence withaggressive initial surgical resection. Despite their findingsthey still had a high rate of recurrence. In 1 1 patients,24 procedures were performed and there were 16recurrences. Two primary fasciectomies did not recur. Threeof 6 revisional procedures that had complete fasciectomiesrecurred. This was compared with recurrences in 7 of 9 wideexcisions and 6 of7 local excisions.'

Similarly, Aluisio et al identified an increasedchance of recurrence with multiple nodules, bilaterallesions and a positive family history. Seventeen patients intheir study had primary surgery, 4 of 10 local excisions, 1of 3 wide excisions and 2 of 4 subtotal fasciectomiesdeveloped recurrence. Twenry-one patients had revisional

surgery. In the treatment of recurrent lesions subtotalfasciotomy was superior to local or wide excision. Threeof 4 had recurrence with local or wide excision. Only 4 of17 patients had recurrence with subtotal fasciotomy. A11patients with recurrences developed the problem within1 4 months postoperative.' Utilizing subtotal fasciectomy,Sammarco et al had only 2 recurrences in 23 cases with an86% satisfaction rate.r'\Tapner et al had only 1recurrence in 12 cases.' DeBree et al had a 90o/orecurrence rate in primary excisions followed by a 50o/orecurrence in subsequent surgies.'a

In order to decrease recurrence, adjuvant radio-therapy has been attempted. Postoperative radiotherapydecreases the recurrence rate although it has led to seriousside effects. Therefore, its use has been significantlylimited.'a Other attempts to lessen recurrence haveincluded use of Marlex mesh' and free dermal fatgraftsn although these modalities have not beenimplemented routinely.

CHAPTER 17 93

Biomechanical effects also are an important consider-ations for long-term positive ourcomes. Under tension, theplantar fascia functions to support the longitudinal arch,supinate the rearfoot, and stabilize the digits to the ground.Pontious et al described hammertoes as a postoperarivecomplication associated with plantar fasciectomy.'6Sammarco et al also showed that plantar fasciectomy leadto a slight decrease in calcaneal inclination, navicularheight, and medial cuneiform height demonstrating theloss of medial longitudinai arch height secondary to seftlingphenomenon.'1 In order to dissipate these potentialproblems after planrar fasciectomy the author recommendspostoperative use of custom molded orthoses to decreasethe subsequent strain in the arch after plantar fasciectomy.

CONCLUSION

Plantar fibromatosis is a rare, benign, Iocally-aggressivefibroproliferative disorder involving the plantar fascia.Symptomatic lesions that require surgical interventionneed to be addressed with complete (subtotal) plantarfasciectomy with particular attention to incision place-ment, exposure/visualization, and anatomic dissection toavoid potential complications that can occur frequently.

REFERENCES

1. Mahan KT. Plantar fibromatosis: surgical considerations. In McGIamryED, editor. Reconstrucriye Surgery of the Foot and Leg, Update '86.Tucker, GA: Podiatry Institute. p. 161-4.

2. \flapner KL, Ververelli PA, Moore JH, Hecht PJ, Becker CE, LackmanRD. Plantar fibromatosis: a review of primary and recurrent surgicaltreatment. Foot Anhle Int 1995r16:548-51.

3. Landers PA, Yu GV, rX4rite JM, Farrer AK. Recurrent plantar fibro-matosis. J Foot Anhle Surg 1993; 32:85-93.

4. Curtin J\fl. Surgical therapy for dupuytren's disease of the foot: properplacement and design ofskin incision. PLxt Reconsn Surg 1962;30:568-76.

5. OsterJA, Miller AE. Resection of plantar fibromatosis with interpositionof Marlex mesh. J Foot Surg 1986:25:217 -25..

6. Lauf E, Freedman BM, Steinberg JS. Autogenous free dermal fat graftsin the surgical approach to plantar fibromatosis. J Foot Ankle Surg199837:227-34.

Zgonis T, Jolly GP, Polyzois V, Kanuck DM, Stamatis ED. Plantarfibromarosi.. Clin Pnd Mcd Surg )00\:)):l l-\.Durr HR, Krodel A, Trouillier H, Lienemann A, Refior HJ.Fibromatosis ofthe plantar fascia: diagnosis and indications for surgicaltreatment. Foot Ankle Int l