- Email: [email protected]
Giant cell tumour around the foot and ankle
Foot and Ankle Surgery 12 (2006) 99–102 www.elsevier.com/locate/fas
Giant cell tumour around the foot and ankle S. Kamath a,b,*, M. Jane a, R. Reid a a
Western Infirmary, Glasgow G11 6NT, United Kingdom Whiston Hospital, Prescot L45 5DR, United Kingdom
b
Received 13 April 2005; received in revised form 6 December 2005; accepted 13 February 2006
Abstract Giant cell tumour (GCT) has been known to behave unpredictably when located in the foot and ankle bones. Involvement of foot and ankle bones is rare and comprises of less than 4% of all the GCTs. Out of 175 cases of GCT documented in the Scottish Bone Tumour Registry, 8 cases arose from foot and ankle. The mean age was 28.8 years (13–47). These included six males and two females. Pain and swelling was the common mode of presentation. All the cases had minimum follow-up of 36 months (36–180) and had definitive treatment within the first 3 months of initial presentation. The Campannacci radiographic staging system was used in grading the tumours. Seven of eight cases had intralesional procedure, while the remaining one had primary below knee amputation. One case had local recurrence within 2 years of the initial treatment requiring further surgery. Five out of seven cases with curettage involved the distal tibia or fibula. We had one recurrence of the three cases involving the tarsal bones, which reflects the difficulty in achieving thorough curettage in small bone tumours. Thorough curettage and bone grafting with adjuvant therapy has a low recurrence rate and should be considered when possible particularly in the long bones. Use of bone cement may be a better option in small bone involvement in view of difficulty in achieving thorough curettage. Regular follow-up helps detect early recurrence. # 2006 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved. Keywords: Giant cell tumour; GCT; Foot; Ankle; Recurrence
1. Introduction Giant cell tumour (GCT) is a primary bone tumour occurring in young adults accounting for 5–8% of primary bone tumours [1], the typical sites of involvement being long bones around the knee, proximal femur and wrist joint. Foot and ankle bone involvement is rare and comprises less than 4% of all GCTs [2]. Unni [3] reports an incidence of 1.2% and Mirra et al. [4] of less than 2% incidence of GCT in the foot. Though GCT are known to possess limited capacity to metastasize, local aggressiveness with high local recurrence rates have been well-documented [2,5]. GCT around the foot and ankle are known to be unpredictable in their behaviour. O’Keefe et al. [2] suggest that tumours affecting the distal extremities behave in a less aggressive way than those centrally located, while Biscaglia * Correspondence to: 4 Dakota Drive, Great Sankey, Warrington WA5 8GA, United Kingdom. Tel.: +44 1925 234 736. E-mail address: [email protected] (S. Kamath).
et al. [6] mention that GCT of hand and foot are more aggressive and recommend aggressive treatment. We retrospectively reviewed the GCTs around the foot and ankle region documented in the Scottish Bone Tumour Registry to analyse the tumour behaviour and the outcome of surgical management. 2. Material and methods The study includes 8 cases involving the bones around foot and ankle of the 175 cases coded as GCT in the Scottish Bone Tumour Registry from 1954 to 2000. The Tumour Registry is a prospective database, which updates follow-up data of patients by obtaining information from oncology and surgical clinics and family physicians. All cases of malignant and locally aggressive tumours are followed up until discharge from clinic; death or follow-up is irretrievably lost. All the available clinical data was evaluated and the histology and radiographs reviewed. The study comprised six males and two
1268-7731/$ – see front matter # 2006 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.fas.2006.02.001
100
S. Kamath et al. / Foot and Ankle Surgery 12 (2006) 99–102
Table 1
1 2 3 4 5 6 7 8
Sex
Duration of symptom (months)
Bone
Site
X-ray classn [7]
Treatment
Recurrence
Further treatment
M F F M M M M M
1–3 9–12 9–12 <1 fracture 6–9 1–3 3–6 <1 fracture
Os calcis Talus Tibia Tibia Tibia Tibia Cuneiform Fibula
Body Neck Distal epimetaphysis Distal epimetaphysis Distal epimetaphysis Distal epimetaphysis Body Malleoli
1 1 2 3 2 2 3 3
C&BG (burr + H2O2) B/K amp C&BG (H2O2) C&BG (H2O2) C&BG (5% phenol) C&BG (H2O2) C&BG (burr + H2O2) C&BG (H2O2)
n n n n n n y n
n n n n n n C&cement n
C&BG, curettage and bone grafting; B/K amp, below knee amputation; n, no; y, yes.
Table 2 Campanacci radiographic classification [7] Grading
Description
I II
Well-marginated border of a thin rim of mature bone, and the cortex was intact or slightly thinned but not deformed Relatively well-defined margins but no radio-paque rim; the combined cortex and rim of reactive bone were rather thin and moderately expanded but still present As above with fracture Fuzzy border; the tumour bulged in to the soft tissues, but the soft tissue mass did not follow the contour of the bone and was not limited by an apparent shell of reactive bone
II with fracture III
females and the mean age at presentation was 28.8 years (13– 47). The clinical features are summarized in Table 1. The minimum follow-up was 36 months (36–180 months). The plain radiographs were available in all eight cases. Few had further investigations such as tomograms and MRI
and these when available were reviewed. The lesions were staged radiographically based on the Campanacci classification [7]. This classification is summarized in Table 2. All the histology slides were reviewed by one of the authors (RR) to confirm the diagnosis (Figs. 1 and 2).
Fig. 1. Patient 7: recurrence within 2 years following primary curettage and bone grafting involving the intermediate cuneiform bone.
Fig. 2. Patient 7: 4 years following recurettage and cement.
S. Kamath et al. / Foot and Ankle Surgery 12 (2006) 99–102
Fig. 3. Patient 4: pre-operative radiograph showing eccentric osteolytic lesion in distal tibial epimetaphysis.
3. Treatment and outcome All cases had a histological diagnosis (needle or open biopsy) before definitive surgery. Surgery was the method of treatment in all the cases. Initial treatment comprised thorough curettage and bone grafting in seven cases and one patient had a primary below knee amputation. The below
101
Fig. 5. Patient 4: 4 years post-operative radiograph.
knee amputation was chosen by the patient after the alternative options and the likely recurrence rate was discussed. In the remaining seven cases intraregional curettage was performed along with adjuvant therapy in the form of chemical cautery with 5% phenol in one case and hydrogen peroxide in four cases. High-speed burrs were used in the remaining two along with chemical therapy (H2O2) (Table 1). Four cases had autologous iliac crest grafts and the remaining had synthetic graft to fill the cavity. All the cases were followed up at 2 weeks, 6 weeks and 3 monthly intervals for the first 2 years. X-rays were performed at 3 monthly intervals, and MRI scan were done only in cases with clinical or radiographic suspicion of recurrence. One case had local recurrence within the first 2 years of primary treatment, treated by re-curettage and bone cement. All the cases had a minimum of 3 years follow-up postsurgery and none showed signs of recurrence at the time of latest follow-up (Figs. 3–5).
4. Discussion
Fig. 4. Patient 4: axial CT section confirming breach in posterolateral cortex.
Most GCTs occur in skeletally mature patients. In our series the mean age was 28.8 years, consistent with most other series [1,2,5]. The majority of tumours in other series [1,2,7] arose in the ankle region with the metatarsals and phalanges less commonly involved. Histological grading is controversial and is said to be unreliable in predicting tumour recurrence [4,8,10]. Campanacci et al. [7] and other studies [2,9] have correlated the radiological destruction with the propensity for recurrence. The typical findings of an eccentric expansile osteolytic lesion are not usually seen in GCT of the foot and ankle bones [1]. The usual findings are
102
S. Kamath et al. / Foot and Ankle Surgery 12 (2006) 99–102
areas of bone destruction with expansion or erosion of cortex and it is recognized that radiographic staging can be difficult with tumours around foot and ankle. GCT of bone is a locally aggressive tumour with a high tendency to recur after removal. Treatment protocols have varied from curettage and bone graft with adjuncts such as liquid nitrogen, phenol or bone cement to partial or complete excision, amputation and radiotherapy in some cases [1,10]. The rates of recurrence after simple curettage ranged from 10 to 47% as compared with 10% after curettage and adjuvant treatment [5]. The overall recurrence rate for GCT involving bones of the hand and foot is higher in comparison with GCT in more conventional sites [6], which might suggest greater biologic aggressiveness when small bones are involved or may simply reflect the difficulty in achieving thorough curettage especially if there is extra osseous extension. McDonald et al. [11] found that the incidence of recurrence correlated with the method of removal and not the histologic or radiographic grading. Biscaglia et al. [6] in their series noted 50% recurrence rate after curettage and bone grafting and lesser recurrence following use of adjuncts like phenol or after resection. Richardson et al. [8] in their series preferred vigorous curettage and use of burrs followed by bone grafting in grade 1 and 2 lesions with no local recurrence at 5 years follow-up. In our series, five out of seven cases involved the distal tibia or fibula. We had one recurrence of the three cases involving the tarsal bones, which reflects the difficulty in achieving thorough curettage in small bone tumours. Use of bone cement (PMMA) has been suggested as an alternative to bone grafting to reduce the recurrence rate. The heat given off by the hardening PMMA is thought to lead to thermal necrosis of the remaining tumour cells in the curetted cavity [12]. The PMMA technique, compared with bone grafting, offers the advantages of lack of donor-site morbidity, an unlimited supply, immediate structural stability, low cost, and ease of use. In addition, the barium contained in the methylmethacrylate results in a radiopaque substance that sharply contrasts with the surrounding bone. Local recurrences are more readily apparent than in cases in which bone graft is used. The disadvantages of using cement include difficulty in removing it when revision is needed and the possibility that subchondral cement may predispose the joint to early degenerative osteoarthritis [13]. Frassica et al. [14] showed
that subchondral bone grafts are superior to cement for restoration of the normal subchondral anatomy. Thorough curettage and bone grafting with adjuvant therapy has a low recurrence rate and should be considered when possible particularly in the long bones. Use of bone cement may be a better option in small bone involvement in view of difficulty in achieving thorough curettage. Regular follow-up particularly in the first 2 years of initial surgery helps in detecting recurrence at an early stage. GCTs around foot and ankle are relatively rare and, while our series of eight cases is small and insufficient to draw any definite conclusions, should add further information in managing tumours in this region. References [1] Dhillon MS, Singh B, Gill SS, et al. Management of giant cell tumor of the tarsal bones: a report of nine cases and a review of the literature. Foot Ankle 1993;14(5):265–72. [2] O’Keefe RJ, O’Donnell RJ, Temple HT, et al. Giant cell tumor of bone in the foot and ankle. Foot Ankle Int 1995;16(10):617–23. [3] Unni KK, editor. Dahlin’s bone tumours: general aspects and data on 11087 cases. 5th ed., Philadelphia: Lippincott–Raven; 1996. p. 263– 83. [4] Mirra JM, Picci P, Gold RH, editors. Bone tumors: clinical, radiologic and pathologic correlations. Philadelphia: Lea & Febiger; 1989 . p. 941–1020. [5] Yip KMH, Leung PC. Giant cell tumor of bone. Clin Orthop 1996;323:60–4. [6] Biscaglia R, Bacchini P, Bertoni F. Giant cell tumor of the bones of the hand and foot. Cancer 2000;88(9):2022–32. [7] Campanacci M, Baldini N, Boriani S, Sudanese A. Giant cell tumor of bone. J Bone Jt Surg 1987;69A(1):106–14. [8] Richardson MJ, Dickinson IC. Giant cell tumor of bone. Bull Hosp Jt Dis 1998;57(1):6–10. [9] Eckhardt JJ, Grogan TJ. Giant cell tumor of the bone. Clin Orthop Rel Res 1986;204:45–58. [10] Schajowicz F. Tumors and tumorlike lesions of bone: pathology, radiology and treatment, 2nd ed., Springer–Verlag; 1994. p. 257–294. [11] McDonald DJ, Sim FH, McLeod RA, et al. Giant cell tumor of bone. J Bone Jt Surg 1986;68A:235–42. [12] Leeson MC, Lippitt SB. Thermal aspects of the use of polymethylmethacrylate in large metaphyseal defects in bone. A clinical review and laboratory study. Clin Orthop 1993;295:239–45. [13] Persson BM, Wouters HW. Curettage and acrylic cementation in surgery of giant cell tumors of bone. Clin Orthop 1976;120: 125–33. [14] Frassica FJ, Sim FH, Pritchard DJ. Subchondral replacement: a comparative analysis of reconstruction with methyl methacrylate or autogenous bone graft. Chir Org Mov 1990;75(Suppl. 1):189–90.
Giant cell tumour around the foot and ankle S. Kamath a,b,*, M. Jane a, R. Reid a a
Western Infirmary, Glasgow G11 6NT, United Kingdom Whiston Hospital, Prescot L45 5DR, United Kingdom
b
Received 13 April 2005; received in revised form 6 December 2005; accepted 13 February 2006
Abstract Giant cell tumour (GCT) has been known to behave unpredictably when located in the foot and ankle bones. Involvement of foot and ankle bones is rare and comprises of less than 4% of all the GCTs. Out of 175 cases of GCT documented in the Scottish Bone Tumour Registry, 8 cases arose from foot and ankle. The mean age was 28.8 years (13–47). These included six males and two females. Pain and swelling was the common mode of presentation. All the cases had minimum follow-up of 36 months (36–180) and had definitive treatment within the first 3 months of initial presentation. The Campannacci radiographic staging system was used in grading the tumours. Seven of eight cases had intralesional procedure, while the remaining one had primary below knee amputation. One case had local recurrence within 2 years of the initial treatment requiring further surgery. Five out of seven cases with curettage involved the distal tibia or fibula. We had one recurrence of the three cases involving the tarsal bones, which reflects the difficulty in achieving thorough curettage in small bone tumours. Thorough curettage and bone grafting with adjuvant therapy has a low recurrence rate and should be considered when possible particularly in the long bones. Use of bone cement may be a better option in small bone involvement in view of difficulty in achieving thorough curettage. Regular follow-up helps detect early recurrence. # 2006 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved. Keywords: Giant cell tumour; GCT; Foot; Ankle; Recurrence
1. Introduction Giant cell tumour (GCT) is a primary bone tumour occurring in young adults accounting for 5–8% of primary bone tumours [1], the typical sites of involvement being long bones around the knee, proximal femur and wrist joint. Foot and ankle bone involvement is rare and comprises less than 4% of all GCTs [2]. Unni [3] reports an incidence of 1.2% and Mirra et al. [4] of less than 2% incidence of GCT in the foot. Though GCT are known to possess limited capacity to metastasize, local aggressiveness with high local recurrence rates have been well-documented [2,5]. GCT around the foot and ankle are known to be unpredictable in their behaviour. O’Keefe et al. [2] suggest that tumours affecting the distal extremities behave in a less aggressive way than those centrally located, while Biscaglia * Correspondence to: 4 Dakota Drive, Great Sankey, Warrington WA5 8GA, United Kingdom. Tel.: +44 1925 234 736. E-mail address: [email protected] (S. Kamath).
et al. [6] mention that GCT of hand and foot are more aggressive and recommend aggressive treatment. We retrospectively reviewed the GCTs around the foot and ankle region documented in the Scottish Bone Tumour Registry to analyse the tumour behaviour and the outcome of surgical management. 2. Material and methods The study includes 8 cases involving the bones around foot and ankle of the 175 cases coded as GCT in the Scottish Bone Tumour Registry from 1954 to 2000. The Tumour Registry is a prospective database, which updates follow-up data of patients by obtaining information from oncology and surgical clinics and family physicians. All cases of malignant and locally aggressive tumours are followed up until discharge from clinic; death or follow-up is irretrievably lost. All the available clinical data was evaluated and the histology and radiographs reviewed. The study comprised six males and two
1268-7731/$ – see front matter # 2006 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.fas.2006.02.001
100
S. Kamath et al. / Foot and Ankle Surgery 12 (2006) 99–102
Table 1
1 2 3 4 5 6 7 8
Sex
Duration of symptom (months)
Bone
Site
X-ray classn [7]
Treatment
Recurrence
Further treatment
M F F M M M M M
1–3 9–12 9–12 <1 fracture 6–9 1–3 3–6 <1 fracture
Os calcis Talus Tibia Tibia Tibia Tibia Cuneiform Fibula
Body Neck Distal epimetaphysis Distal epimetaphysis Distal epimetaphysis Distal epimetaphysis Body Malleoli
1 1 2 3 2 2 3 3
C&BG (burr + H2O2) B/K amp C&BG (H2O2) C&BG (H2O2) C&BG (5% phenol) C&BG (H2O2) C&BG (burr + H2O2) C&BG (H2O2)
n n n n n n y n
n n n n n n C&cement n
C&BG, curettage and bone grafting; B/K amp, below knee amputation; n, no; y, yes.
Table 2 Campanacci radiographic classification [7] Grading
Description
I II
Well-marginated border of a thin rim of mature bone, and the cortex was intact or slightly thinned but not deformed Relatively well-defined margins but no radio-paque rim; the combined cortex and rim of reactive bone were rather thin and moderately expanded but still present As above with fracture Fuzzy border; the tumour bulged in to the soft tissues, but the soft tissue mass did not follow the contour of the bone and was not limited by an apparent shell of reactive bone
II with fracture III
females and the mean age at presentation was 28.8 years (13– 47). The clinical features are summarized in Table 1. The minimum follow-up was 36 months (36–180 months). The plain radiographs were available in all eight cases. Few had further investigations such as tomograms and MRI
and these when available were reviewed. The lesions were staged radiographically based on the Campanacci classification [7]. This classification is summarized in Table 2. All the histology slides were reviewed by one of the authors (RR) to confirm the diagnosis (Figs. 1 and 2).
Fig. 1. Patient 7: recurrence within 2 years following primary curettage and bone grafting involving the intermediate cuneiform bone.
Fig. 2. Patient 7: 4 years following recurettage and cement.
S. Kamath et al. / Foot and Ankle Surgery 12 (2006) 99–102
Fig. 3. Patient 4: pre-operative radiograph showing eccentric osteolytic lesion in distal tibial epimetaphysis.
3. Treatment and outcome All cases had a histological diagnosis (needle or open biopsy) before definitive surgery. Surgery was the method of treatment in all the cases. Initial treatment comprised thorough curettage and bone grafting in seven cases and one patient had a primary below knee amputation. The below
101
Fig. 5. Patient 4: 4 years post-operative radiograph.
knee amputation was chosen by the patient after the alternative options and the likely recurrence rate was discussed. In the remaining seven cases intraregional curettage was performed along with adjuvant therapy in the form of chemical cautery with 5% phenol in one case and hydrogen peroxide in four cases. High-speed burrs were used in the remaining two along with chemical therapy (H2O2) (Table 1). Four cases had autologous iliac crest grafts and the remaining had synthetic graft to fill the cavity. All the cases were followed up at 2 weeks, 6 weeks and 3 monthly intervals for the first 2 years. X-rays were performed at 3 monthly intervals, and MRI scan were done only in cases with clinical or radiographic suspicion of recurrence. One case had local recurrence within the first 2 years of primary treatment, treated by re-curettage and bone cement. All the cases had a minimum of 3 years follow-up postsurgery and none showed signs of recurrence at the time of latest follow-up (Figs. 3–5).
4. Discussion
Fig. 4. Patient 4: axial CT section confirming breach in posterolateral cortex.
Most GCTs occur in skeletally mature patients. In our series the mean age was 28.8 years, consistent with most other series [1,2,5]. The majority of tumours in other series [1,2,7] arose in the ankle region with the metatarsals and phalanges less commonly involved. Histological grading is controversial and is said to be unreliable in predicting tumour recurrence [4,8,10]. Campanacci et al. [7] and other studies [2,9] have correlated the radiological destruction with the propensity for recurrence. The typical findings of an eccentric expansile osteolytic lesion are not usually seen in GCT of the foot and ankle bones [1]. The usual findings are
102
S. Kamath et al. / Foot and Ankle Surgery 12 (2006) 99–102
areas of bone destruction with expansion or erosion of cortex and it is recognized that radiographic staging can be difficult with tumours around foot and ankle. GCT of bone is a locally aggressive tumour with a high tendency to recur after removal. Treatment protocols have varied from curettage and bone graft with adjuncts such as liquid nitrogen, phenol or bone cement to partial or complete excision, amputation and radiotherapy in some cases [1,10]. The rates of recurrence after simple curettage ranged from 10 to 47% as compared with 10% after curettage and adjuvant treatment [5]. The overall recurrence rate for GCT involving bones of the hand and foot is higher in comparison with GCT in more conventional sites [6], which might suggest greater biologic aggressiveness when small bones are involved or may simply reflect the difficulty in achieving thorough curettage especially if there is extra osseous extension. McDonald et al. [11] found that the incidence of recurrence correlated with the method of removal and not the histologic or radiographic grading. Biscaglia et al. [6] in their series noted 50% recurrence rate after curettage and bone grafting and lesser recurrence following use of adjuncts like phenol or after resection. Richardson et al. [8] in their series preferred vigorous curettage and use of burrs followed by bone grafting in grade 1 and 2 lesions with no local recurrence at 5 years follow-up. In our series, five out of seven cases involved the distal tibia or fibula. We had one recurrence of the three cases involving the tarsal bones, which reflects the difficulty in achieving thorough curettage in small bone tumours. Use of bone cement (PMMA) has been suggested as an alternative to bone grafting to reduce the recurrence rate. The heat given off by the hardening PMMA is thought to lead to thermal necrosis of the remaining tumour cells in the curetted cavity [12]. The PMMA technique, compared with bone grafting, offers the advantages of lack of donor-site morbidity, an unlimited supply, immediate structural stability, low cost, and ease of use. In addition, the barium contained in the methylmethacrylate results in a radiopaque substance that sharply contrasts with the surrounding bone. Local recurrences are more readily apparent than in cases in which bone graft is used. The disadvantages of using cement include difficulty in removing it when revision is needed and the possibility that subchondral cement may predispose the joint to early degenerative osteoarthritis [13]. Frassica et al. [14] showed
that subchondral bone grafts are superior to cement for restoration of the normal subchondral anatomy. Thorough curettage and bone grafting with adjuvant therapy has a low recurrence rate and should be considered when possible particularly in the long bones. Use of bone cement may be a better option in small bone involvement in view of difficulty in achieving thorough curettage. Regular follow-up particularly in the first 2 years of initial surgery helps in detecting recurrence at an early stage. GCTs around foot and ankle are relatively rare and, while our series of eight cases is small and insufficient to draw any definite conclusions, should add further information in managing tumours in this region. References [1] Dhillon MS, Singh B, Gill SS, et al. Management of giant cell tumor of the tarsal bones: a report of nine cases and a review of the literature. Foot Ankle 1993;14(5):265–72. [2] O’Keefe RJ, O’Donnell RJ, Temple HT, et al. Giant cell tumor of bone in the foot and ankle. Foot Ankle Int 1995;16(10):617–23. [3] Unni KK, editor. Dahlin’s bone tumours: general aspects and data on 11087 cases. 5th ed., Philadelphia: Lippincott–Raven; 1996. p. 263– 83. [4] Mirra JM, Picci P, Gold RH, editors. Bone tumors: clinical, radiologic and pathologic correlations. Philadelphia: Lea & Febiger; 1989 . p. 941–1020. [5] Yip KMH, Leung PC. Giant cell tumor of bone. Clin Orthop 1996;323:60–4. [6] Biscaglia R, Bacchini P, Bertoni F. Giant cell tumor of the bones of the hand and foot. Cancer 2000;88(9):2022–32. [7] Campanacci M, Baldini N, Boriani S, Sudanese A. Giant cell tumor of bone. J Bone Jt Surg 1987;69A(1):106–14. [8] Richardson MJ, Dickinson IC. Giant cell tumor of bone. Bull Hosp Jt Dis 1998;57(1):6–10. [9] Eckhardt JJ, Grogan TJ. Giant cell tumor of the bone. Clin Orthop Rel Res 1986;204:45–58. [10] Schajowicz F. Tumors and tumorlike lesions of bone: pathology, radiology and treatment, 2nd ed., Springer–Verlag; 1994. p. 257–294. [11] McDonald DJ, Sim FH, McLeod RA, et al. Giant cell tumor of bone. J Bone Jt Surg 1986;68A:235–42. [12] Leeson MC, Lippitt SB. Thermal aspects of the use of polymethylmethacrylate in large metaphyseal defects in bone. A clinical review and laboratory study. Clin Orthop 1993;295:239–45. [13] Persson BM, Wouters HW. Curettage and acrylic cementation in surgery of giant cell tumors of bone. Clin Orthop 1976;120: 125–33. [14] Frassica FJ, Sim FH, Pritchard DJ. Subchondral replacement: a comparative analysis of reconstruction with methyl methacrylate or autogenous bone graft. Chir Org Mov 1990;75(Suppl. 1):189–90.