Treatment of Enchondromaof the Hand with Injectable

Calcium Phosphate Bone Cement

Masataka Yasuda, MD, Kazuhiro Masada, MD, Eiji Takeuchi, MD

From the Department of Orthopaedic Surgery, Osaka Saiseikai Nakatsu Hospital, Osaka, Japan; andthe Department of Orthopaedic Surgery, Osaka Rosai Hospital, Osaka, Japan.

Purpose: To report the results of treatment of enchondroma of the hand managed by curettageand calcium phosphate bone cement (CPC) grafting.Methods: Ten patients with digital enchondroma were reviewed. There were 6 proximal pha-langes, 2 middle phalanges, and 2 metacarpal bones. The average patient age at surgery was 31years. The average follow-up period was 41 months. We reviewed the final function and radiographicappearance of the surgically treated digits. We defined the term bony incorporation of CPC as aseamless change of radiographic appearance and no gap between cancellous bone and CPC.Results: At final evaluation the bony incorporation was uneventful in all patients. Radio-graphs showed apparent partial absorption of CPC in only 2 patients. All digits had full rangeof motion after surgery. One digit fixed with multiple pins to treat a pathologic fracturesimultaneously resulted in malunion and needed additional surgeries to correct digitaloverlap. No other complications were encountered.Conclusions: Patients with enchondroma of the hand are good candidates for treatment withCPC. In the case of pathologic fracture before surgery, however, surgery may be delayed untilfracture healing because early corrective osteotomy with CPC might be difficult in a patientwith malunion (J Hand Surg 2006;31A:98–102. Copyright © 2006 by the American Societyfor Surgery of the Hand.)Type of study/level of evidence: Therapeutic, Level IV.Key words: Enchondroma, calcium phosphate bone cement, surgery, pathologic fracture.

In treating enchondromas of the hand, hand sur-geons aim to prevent pathologic fracture andremove the tumor. When the cortex is thin and/or one

intends to stabilize a pathologic fracture simultaneously,internal fixation may be needed. To avoid additional injuryto the patient calcium phosphate bone cement (CPC) canbe used to treat enchondroma of the hand. Joosten et al1

first reported 8 patients with enchondroma who weretreated with CPC (BoneSource; Liebinger Corp., Kalama-zoo, MI) grafting without fixation; however, their reportwas only a 1-year prospective study. We report the resultsof 10 patients with enchondroma who were treated withcurettage and CPC (Biopex; Mitsubishi Materials Corp.,Tokyo, Japan) grafting with a minimum of 2 years offollow-up evaluation.

Materials and MethodsThe study consisted of 6 proximal phalanges, 2 mid-

dle phalanges, and 2 metacarpal bones. There were 7

98 The Journal of Hand Surgery

male and 3 female patients. The enchondromas wereclassified into 5 types according to the classificationsystem of Takigawa2: central, eccentric, associated,polycentric, and giant. No patients had associateddisease such as Ollier’s disease (Table 1). The aver-age preoperative period (time from original diagnosisto surgery) was 14 months (range, 18 d to 9 y). Theaverage age at surgery was 31 years (range, 11–70 y).The average follow-up period was 41 months (range,30–51 mo). Five digits had pathologic fracture be-fore surgery. One digit (patient 1) was fixed withmultiple pins to treat the fracture simultaneously; theother enchondromas with pathologic fracture weretreated after fracture healing.

Calcium phosphate bone cement (Biopex) consistsmainly of a tricalcium phosphate.3 Six grams ofsterile white powder are mixed with 1.7 mL of sterilesolution until a doughy form is obtained. The paste

then is injected into the tumor cavity to fill it. Phys-

10

Yasuda, Masada, and Takeuchi / Enchondroma Treatment With CPC 99

iologic temperature during the setting period pre-vents thermal injury to surrounding soft tissue. Amaximum compressive strength of 80 MPa had beendeveloped in 7 days at the time of the study but nowtakes only 3 days.3

After retraction or splitting of the extensor tendonover the affected bone a small oval cortical windowis made with a 1.0-mm pin and a small chisel.Through this window the tumor is excised meticu-lously and completely with a small curette. The sizeof the cortical window depends on the tumor sizebecause complete curettage cannot be performedthrough too small a window. Calcium phosphatebone cement in its doughy form is injected into thecavity, forming one volume of the CPC mass. Caremust be taken not to let CPC leak out of the cavity.The thin cortex is reduced back to the original win-dow without any internal fixation. No postoperativesplint is used; only a bulky dressing is applied. Oneweek after surgery range of motion exercises arestarted.

We studied the clinical results and complicationsof this procedure. We measured tumor size based onits greatest length and width on the posteroanteriorview. We defined the term bony incorporation ofCPC as a seamless change of radiographic appear-ance and no gap between cancellous bone and CPC.We also defined the term absorption of CPC asreplacement by new bone. We evaluated bony incor-poration and absorption of CPC on serial radio-graphs.

ResultsPatient demographics are summarized in Table 1.Histologic diagnosis in all 10 patients was enchon-droma. Bony incorporation was uneventful in allcases. Incorporation of CPC occurred at an average

Table 1. Demographics of 10 Patients with Endoch

No. GenderAge(y) Side Affected Bone

TakigawaClassification

1 M 16 R Ring proximal Central2 M 11 L Index proximal Central3 M 22 R Index proximal Eccentric4 F 45 L Small

metacarpalEccentric

5 M 17 R Smallmetacarpal

Central

6 M 40 R Ring middle Central7 M 35 L Ring proximal Central8 F 32 R Small proximal Eccentric9 M 17 L Middle proximal Central

10 F 70 L Ring middle Eccentric

of 4.5 months (range, 3–6.1 mo) after surgery. Ra-

diographs showed apparent partial absorption of CPCin only 2 patients (patients 1 and 2). All patients hadfull range of motion after surgery. All patients but 1(patient 1) returned to their ordinary daily activitieswithin 4 weeks after surgery. One digit (patient 1)with pathologic fracture fixed with pins resulted inmalunion and received additional surgeries to correctthe digital overlap (Fig. 1). We performed the cor-rective shortening osteotomy (fixed with screws) atthe distal metaphyseal area 6 months after the initial

Figure 1. Posteroanterior radiograph at 7 weeks after surgeryshowing malunion of the phalanx with ulnar angulation. The

ma

izengthidthm)

PreoperativePeriod (mo)

Follow-Up Period

(mo)PathologicFracture

OtherFindings

� 10 0.6 51 Yes� 11 2.2 48 Yes� 11 10.5 48 No� 9 1.8 31 No

� 9 1.2 38 Yes

� 11 3.3 46 No� 12 6.2 40 No� 9 0.9 32 Yes� 9 3.2 46 Yes� 18 110.0 30 No Protuberans

ondro

S(le

� wm

21251516

35

21251025

CPC did not incorporate into the bone.

100 The Journal of Hand Surgery / Vol. 31A No. 1 January 2006

surgery (Fig. 2). Because the patient still was leftwith a slight digital overlap even after osteotomy weperformed removal of the screws, excision of theulnar osteophyte, and resection of the ulnar collateralligament 4 months after the osteotomy (Fig. 3). Norecurrence of enchondroma occurred and no othercomplications were encountered.

DiscussionThere are several treatments for enchondroma: curet-tage alone,4–6 curettage and autogenous bone graft-ing, and curettage and bone graft substitute such asCPC.1,7 Curettage alone leaves dead space and weakbone. Although Sekiya et al6 did not use a splint aftersurgery, Hasselgren et al5 used a plaster-of-parissplint for 1 to 3 weeks. We did not use any splintafter surgery. Sekiya et al6 stated that the specialinstruments and the slightly longer time required forsurgery could be considered disadvantages. WithCPC we can expect easier and shorter surgeries andearly motion of the digit without concern of postop-erative fracture. Autogenous bone grafting does notleave dead space; however, it has the disadvantages

Figure 2. Radiograph showing postosteotomy appearance.The phalanx was cut obliquely from dorsal/distal to volar/proximal and shortened at the distal metaphyseal area andthe angulation deformity was corrected slightly. The CPCincorporated fully into the host bone.

of injury to the harvested area, prolonged surgery

time, bleeding from the harvested area, and mechan-ical weakness immediately after surgery.5 Many non-biologic materials have been used as orthopedic skel-etal substitutes; however, an ideal material has yet tobe developed. Nonbiologic material such as CPC hasthe advantages of being available in unlimited quan-tity and eliminating donor-site morbidity; however,CPC is very expensive.

An ideal material for use in orthopedic reconstruc-tion would have the following properties: unlimitedavailability, biocompatibility, mechanical strength,low risk for infection, replacement by normal bone,easy incorporation into the defect, and radiopacity.8

Norian SRS (Norian Corp., Cupertino, CA) achievesits maximum compressive strength of approximately50 MPa in approximately 12 hours.9,10 The chemicalreaction of BoneSource is complete within 4 hours,10

during which a maximum compressive strength of 36MPa has been developed. Biopex achieves a greatermaximum compressive strength than Norian andBoneSource3 but its final setting time is the longestof these synthetic materials. The initial setting time isabout 10 minutes in all materials.

Joosten et al1 first reported a 1-year prospectivestudy of 8 patients with enchondroma who weretreated with CPC (BoneSource) grafting without anyfixation. All patients had full functional recovery andthere were no complications. There was little evi-

Figure 3. At final follow-up evaluation the patient had nodigital overlap and radiograph showed partial absorption of

CPC.

Yasuda, Masada, and Takeuchi / Enchondroma Treatment With CPC 101

dence of new bone formation in the cavities over theassessment period.

Bickels et al7 reported 13 patients with enchon-droma who were treated with curettage and cementedinternal fixation with polymethylmethacrylate(PMMA) and followed-up for more than 2 years.They concluded that reconstruction of the tumor cav-ity with cemented hardware provides immediate me-chanical stability, allows early mobilization, and isassociated with good functional outcome. They didnot mention any comparison between PMMA andCPC. Calcium phosphate bone cement offers theadvantages over PMMA of eventual osseous resorp-tion and euthermic consolidation reaction.9,11 Com-parison of the in vitro strengths of CPC and PMMAin subchondral bone defects has shown that CPC isstronger than PMMA.11

One disadvantage of any nonbiologic material isthat it has no blood supply, and if it becomes infectedremoval is required to allow resolution of the infec-tions. We encountered no infections. When an en-chondroma has a pathologic fracture simultaneously,early stabilization and biopsy examination may beindicated to shorten the period of disability. Abloveet al12 recommended delayed surgery, which meanssurgery after fracture healing to avoid complications.In this clinical study 1 patient (patient 1) had a poorclinical course when we tried to treat the tumor andpathologic fracture simultaneously (Figs. 4, 5). If

Figure 4. Radiograph showing the tumorous lesion andpathologic comminuted fracture of the ring middle phalanx.

The finger showed no angulation deformity before surgery.

autogenous bone grafting is used then early correc-tive osteotomy is performed. When CPC is used,however, the indication for corrective osteotomy ispostponed. In the case of pathologic fracture beforesurgery, surgery may be delayed until fracture heal-ing, especially when planning to use CPC.

Calcium phosphate bone cement has the uniquecharacteristics of being a paste and hardening fast;however, these advantages have an adverse effect onsound healing of the surgically treated digit. Careshould be taken not to let CPC leak out of bones.Leakage of CPC may cause soft-tissue complica-tions.13

Received for publication July 14, 2003; accepted in revised form August23, 2005.

No benefits in any form have been received or will be received froma commercial party related directly or indirectly to the subject of thisarticle.

Corresponding author: Dr. Masataka Yasuda, 2-10-39 Shibata, Kita-ku, Osaka 530-0012, Japan; e-mail: hand@gaia.eonet.ne.jp.

Copyright © 2006 by the American Society for Surgery of the Hand0363-5023/06/31A01-0018$32.00/0doi:10.1016/j.jhsa.2005.08.017

References1. Joosten U, Joist A, Frebel T, Walter M, Langer M. The use

of an in situ curing hydroxyapatite cement as an alternativeto bone graft following removal of enchondroma of the

Figure 5. Immediately postoperative radiograph showingmultiple-pin fixation and CPC grafting. The cortex is verythin.

hand. J Hand Surg 2000;25B:288–291.

102 The Journal of Hand Surgery / Vol. 31A No. 1 January 2006

2. Takigawa K. Chondroma of the bones of the hand. J BoneJoint Surg 1971;53A:1591–1600.

3. Asaoka N, Misago M, Hirano M, Takeuchi H. Mechanicaland chemical properties of the injectable calcium phosphatecement. Bioceramics 1999;12:525–528.

4. Tordai P, Hoglund M, Lugnegard H. Is the treatment ofenchondroma in the hand by simple curettage a rewardingmethod? J Hand Surg 1990;15B:331–334.

5. Hasselgren G, Forssblad P, Törnvall A. Bone grafting un-necessary in the treatment of enchondromas in the hand.J Hand Surg 1991;16A:139–142.

6. Sekiya I, Matsui N, Otsuka T, Kobayashi M, Tsuchiya D.The treatment of enchondromas in the hand by endoscopiccurettage without bone grafting. J Hand Surg 1997;22B:230–234.

7. Bickels J, Wittig JC, Kollender Y, Kellar-Graney K, Man-sour KL, Meller I, Malawer MM. Enchondromas of thehand: treatment with curettage and cemented internal fixa-

tion. J Hand Surg 2002;27A:870–875.

8. Frankenburg EP, Goldstein SA, Bauer TW, Harris SA, PoserRD. Biomechanical and histological evaluation of a calciumphosphate cement. J Bone Joint Surg 1998;80A:1112–1124.

9. Constantz BR, Ison IC, Fulmer MT, Poser RD, Smith ST,VanWagoner M, et al. Skeletal repair by in situ formation ofthe mineral phase of bone. Science 1995;267:1796–1799.

10. Schmitz JP, Hollinger JO, Milam SB. Reconstruction ofbone using calcium phosphate bone cement: a critical re-view. J Oral Maxillofac Surg 1999;57:1122–1126.

11. Crawford K, Berrey BH, Pierce WA, Welch RD. In vitrostrength comparison of hydroxyapatite cement and poly-methylmethacrylate in subchondral defects in caprine fem-ora. J Orthop Res 1998;16:715–719.

12. Ablove RH, Moy OJ, Peimer CA, Wheeler DR. Early versusdelayed treatment of enchondroma. Am J Orthop 2000;29:771–772.

13. Yamamoto T, Onga T, Marui T, Mizuno K. Use of hydroxy-apatite to fill cavities after excision of benign bone tumours.

J Bone Joint Surg 2000;82B:1117–1120.