Annals of the Royal College of Surgeons of England (1992) vol. 74, 13-18
Endoprosthetic replacement for bony metastases D Chan FRCSEd Orthopaedic Registrar
S R Carter
FRCS
Senior Orthopaedic Registrar
R J Grimer
FRCS FRCSEd(Orth)
Consultant Orthopaedic Surgeon
R S Sneath
FRCS
Director, Bone Tumour Treatment Service
The Bone Tumour Treatment Service, Royal Orthopaedic Hospital, Birmingham
Key words: Bone neoplasm; Bone metastasis; Pathological fractures; Endoprosthesis
A series of 38 patients with long bone metastases treated at the Birmingham Bone Tumour Treatment Service with resection of the metastatic lesion and replacement of the bone defect with an endoprosthesis was reviewed. The majority of cases had pathological fractures due to a massive destructive lesion. Two-thirds of the patients had a solitary metastasis. Metastases from hypernephroma and breast carcinoma accounted for the majority of cases. All the patients were independently mobile after the endoprosthetic replacement and were pain free. The average survival rate after the endoprosthetic replacement was 14.7 months and this varies with the primary tumour. The indications for endoprosthetic replacement for the treatment of long bone metastases are outlined and the results and complications are discussed. It is concluded that endoprosthetic replacement for bony metastases is an effective palliative procedure for a selected group of patients.
within the patient's expected lifespan. There have been numerous methods described for achieving these aims (4-7). These involve the use of internal fixation with or without methyl methacrylate augmentation or the use of conventional prostheses. In selected cases, resection and endoprosthetic replacement of part of the involved bone may fulful these aims and may have advantages over other methods of fixation or stabilisation of a bony defect. Endoprosthetic replacement with custom made prostheses have been described in a number of papers (8-9). These have been performed mainly for proximal femoral lesions. The role of endoprosthetic replacement has not been clearly defined. The purpose of this paper is to present our experience in the use of endoprosthetic replacement for the treatment of metastatic bone disease.
Patients and method Since the 1950s there has been an increasing trend for the aggressive and early surgical stabilisation of pathological and impending fractures (1-3). The aim of the orthopaedic surgeon is to maintain or improve the patient's quality of life by the relief of pain, the control of the local disease and the restoration of normal function to the affected limb. Chemotherapy, radiotherapy and hormonal manipulation, where applicable, may be administered to control the primary disease. The onus upon the orthopaedic surgeon is to perform procedures which will achieve these aims and allow rapid rehabilitation. Whatever surgery is contemplated should not prejudice the patient's survival or disseminate disease and it should be of sufficient durability not to fail
Correspondence to: S R Carter FRCS, Royal Orthopaedic Hospital, Woodlands, Northfield, Birmingham B31 2AP
Over the 17 years from 1972 to 1989, 131 patients were referred to the Birmingham Bone Tumour Treatment Service for advice about metastatic disease. Of this group, 42 were considered suitable for an endoprosthetic replacement. Full information was available for 38 patients. The indications for endoprosthetic replacement for long bone metastatic disease were: 1 Those patients with an anticipated survival of greater than 6 months; 2 Inability to achieve the goals of long-standing stability and good function by other methods; 3 Patient prepared to co-operate with the proposed surgical programme. 4 Failure of previous attempts at stabilisation of bone by other methods.
14
D Chan et al.
Table I. Distribution of the primary tumours Primary
Hypernephroma Breast Bronchogenic carcinoma Thyroid carcinoma Prostatic carcinoma Medulloblastoma Unknown Total
Number 15 14 3 2 1 1 2 38
Contraindications were: 1 The presence of infection at the operative site; 2 Previous radiotherapy in a dosage likely to prejudice soft tissue and wound healing; 3 The results of endoprosthetic replacement unlikely to be better than other methods of reconstruction. The age range of this group of patients was from 23 to 76.7 years, with 11 males and 27 females. The average age was 54 years. A total of 25 patients presented with a pathological fracture, ten of whom had previous internal fixation or implants which failed. Three patients subsequently developed a pathological fracture after referral to the Bone Tumour Treatment Service. The remainder presented with a painful bony lesion, seven of whom did not have a diagnosis of the primary lesion. There were 25 solitary lesions as assessed by bone scintigraphy and 13 multiple lesions. On referral, patients were assessed using staging studies to confirm the extent of the metastatic disease and the general condition of the patient. Those patients presenting with an apparently solitary lesion of bone with no obvious primary had a biopsy performed in an attempt to identify the primary malignancy. In those patients with an untreated primary, advice was sought from appropriate colleagues. Those patients who were thought to be suitable for endoprosthetic replacement had a custom made endoprosthesis manufactured at the Department of Biomedical Engineering of the Royal National Orthopaedic Hospital in London according to previously described methods (10).
Table II. Distribution of the sites of endoprosthetic replacements Site Proximal femur Distal femur Proximal humerus Distal humerus Proximal tibia Total One patient had three endoprostheses Three patients had two endoprostheses
Surgery was performed using oncological principles, the tumour was resected with the aim of achieving a wide margin with a layer of healthy tissue covering the tumour (11). The resected bone was then replaced by the custom made endoprosthesis. All the prostheses were cemented. The knee and elbow joints were constrained hinge joints. Appropriate adjuvant therapy for metastases from breast, prostate and follicular carcinoma of the thyroid was used as appropriate, but local radiotherapy was not required after the resection. The sites of the primary tumour are shown in Table I, and the sites of the endoprosthetic replacements are shown in Table II. A total of 43 endoprostheses were inserted in these 38 patients. One patient received three endoprostheses and three patients received two endoprostheses. The cumulative survival curves were constructed using the method described by Kaplan and Meier (12).
Results of the method for treatment of metajust by assessing the survival of the patients but by determining that the endoprosthetic replacement achieved its aims of maintaining function and providing pain relief while allowing the patient to lead as normal a lifestyle as possible. The patients were able to have reasonable function of their limb, but such a retrospective study does not allow a functional score to be determined. All patients were able to regain independent mobility. It is recognised that endoprosthetic function improves after surgery for a considerable period, some patients did not achieve maximum function or benefit due to their shortened lifespan. In all patients pain was reduced or completely relieved by the insertion of an endoprosthetic replacement.
The
assessment stases was not
Survival rates The survival rate of the 22 patients who have died after endoprosthetic replacement is shown in Table III. One patient who died perioperatively from bronchopneumonia was excluded from the calculations.
Table III. Survival rates after endoprosthetic ment (months)
replace-
Number
Primary
Mean
Median
Range
SD
28
Overall Kidney
14.7 20.7 14.2 3.9 13.3 10.3 19.5 8.7
7.9 13.1 5.9 3.6
2.5-70.2 6.9-70.2 2.7-56.1 2.5- 5.7
17.4 20.8 17.4 1.3
10.3 6.3
2.5-70.2 2.7-25.7
21.5
S 7 2 1 43
Breast
Lung Prostate Brain
Solitary Multiple
7.0
Endoprosthetic replacement for bony metastases At the time of writing, 16 patients were still alive. Four patients with breast metastases are still alive at an average of 7.1 months (range 1.5-16.3 months) after the procedure. Eight patients with hypernephroma metastases are still alive at an average 25.8 months (range 3.5-53.4 months) after the procedure. The two patients with thyroid metastases are both alive at 32.4 months and 84.1 months. The two patients with metastases from an unknown primary are alive at 4.6 and 8.5 months. The cumulative survival curves showing the survival time from surgery in these patients are shown in Fig. 1, with cumulative survival curves of the main primary groups superimposed. A separate cumulative survival graph is constructed for solitary and multiple lesions in Fig. 2.
Complications None of the patients had significant loosening of the endoprosthetic replacement requiring a revision procedure. Two patients developed wound infections and one a lateral popliteal nerve palsy. There was no evidence
All patients *
15
of deep infection. The implant failed in two patients and dislocated in four patients. One of the implant failures occurred in a patient treated early in the series. He had a long-stem Charnley prosthesis inserted for a proximal femoral metastasis from a prostatic primary. This bent into varus and had to be replaced by a custom made endoprosthesis. Since this experience, all the patients have received a custom made endoprosthetic replacement. The other patient with an implant failure had a distal humeral replacement for a hypernephroma metastasis. The polyethylene bearings of the elbow hinge became worn out after 4 years, these were replaced. Shortly afterwards the patient sustained a fracture of the ulnar component of the prosthesis which required further revision surgery. Dislocation of the endoprosthetic replacement occurred in four patients, all of whom had proximal femoral replacements. The dislocations were recurrent in three patients. The patient with the long-stem Charnley prosthesis dislocated this prosthesis three times. One patient dislocated his endoprosthesis twice, while the remaining patient dislocated his endoprosthesis three times. This was almost invariably due to generalised debility and weak muscle tone restricting the ability of the patient to contain their artificial hip joint. The dislocations were all reduced by closed methods and revision surgery was not carried out as the dislocations had been infrequent.
lung
---*.. Hypernephroma O----0-- Breast
Months
Figure 1. Cumulative survival curves according to the primary tumours.
1001
Percentage Survival
90
II II
80
II
II
70
---
II
60-
.W--
Multiple
Solitary
8I II II
II
50
II
II
40
II
L
11
30 1.11
U-1811
20
II
I
10
11I
0I
A
0
20
40
60
80
100
Months Figure 2. Cumulative survival curves of solitary versus multiple
metastases.
( a)
(') Figure 3. (a) A large lytic lesion of the distal femur. (b) Treatment by replacement with a distal femoral endoprosthesis.
16
D Chan et al.
Discussion We have reviewed endoprosthetic replacements of bone in a group of patients with bony metastases where conservative methods of stabilising the skeleton with conventional implants with or without cement would not have provided local tumour control whilst maintaining function. This was particularly the case where the metastatic lesion was extensive (Fig. 3) or when it extended up to a joint surface (Fig. 4). Gross destructive lesions in the trochanteric and cervical regions of the femur make conventional prosthetic replacement impossible. It is in these situations where complex osteosynthesis, even with cement augmentation, is unlikely to lead to long-lasting stability and where an endoprosthetic replacement finds its true role. Complex osteosynthesis after intralesional excision of the metastasis requires adjuvant local treatment such as radiotherapy to prevent local recurrence. The inadequately fixed pathological fracture remains painful and often will not unite after radiotherapy. Some patients, notably those with hypernephroma metastases and breast, do survive for a long time after the development of bony metastases. This likelihood of a prolonged survival is often unpredictable for the individual patient and as a result the patient may have a life span greater than the internal fixation device inserted, particularly if
non-union or local recurrence occurs (Fig. 5). Metastases with poor response rate to radiotherapy are better treated with endoprosthetic replacement (Fig. 6). Endoprosthetic replacement allows complete local resection of the tumour and obviates the need for postoperative radiotherapy. In the patient with a compromised life expectancy, the use of a cemented endoprosthesis allows immediate stable fixation and rapid postoperative mobilisation. Osseous integration of an uncemented prosthesis may be compromised by the catabolic state of the patient. We have made use of custom made endoprostheses in this series but the current availability of modular systems commercially (8) which can be obtained at very short notice may make this type of implant more appropriate for these patients. There is no doubt that an endoprosthesis is more expensive than other possible methods of treatment but the short period of hospitalisation and the stability and durability of the fixation with the lack of major complications should mitigate against this.
I. (a)
JJ)
Figure 4. (a) A distal humeral pathological fracture from a breast carcinoma extending to the articular surface. (b) Resection of the pathological fracture and replacement with a distal humeral endoprosthesis.
(b) (a) Figure 5. (a) A pathological mid-shaft femoral fracture due to a metastasis from a hypernephroma treated with an interlocking intramedullary nail and acrylic cement augmentation failed after 2 years due to local recurrence. (b) Treatment with resection and proximal femoral endoprosthetic replacement.
Endoprosthetic replacement for bony metastases
(a)
(b)
4._
(c)
(d)
Figure 6. (a) A lytic hypernephroma metastasis of the humeral shaft. (b) Treated with Rush nailing and radiotherapy. (c) The tumour was not sensitive to radiotherapy; (d) had to be resected and replaced with a proximal humeral endoprosthesis.
Our results confirm that patients with bony metastases have a capacity to survive a relatively long time. It is our impression, and others have confirmed (13-15), that some patients with metastatic hypernephroma enjoy prolonged survival and indeed some may be considered free of disease. Patients with solitary bony lesions at diagnosis also have longer survival than patients with multiple lesions. At presentation, 26 patients had a solitary bony metastasis and nine patients had evidence of more than one bony metastasis. The average survival of these patients with multiple metastases was 8.7 months, while the average survival for those with a solitary metastasis was 19.5 months. Although it is attractive to entertain the idea of a curative resection for patients with a solitary metastasis it seems that these patients may simply be selected at an earlier stage in their disease. In the group of patients who presented with a solitary metastasis, 11 eventually died with further metastases. Of the remaining patients, five patients had subsequently developed further metastases. It is possible that a patient presenting with a solitary bony metastasis may have multiple undetected micrometastases.
Our patients with metastases from a bronchogenic carcinoma had uniformly low survival rates. This has also been noted by other authors (2,5). It is possible that these tumours are much more aggressive and are at a more advanced stage when they metastasise. We consider that most patients with bony metastases from bronchogenic carcinomas will not be suitable candidates for endoprosthetic replacement. In conclusion, many patients with bony metastatic disease survive a reasonable length of time if given adequate treatment, both for the primary and for the secondary tumour. The mere discovery of a bony metastasis should not be considered a preterminal event. The bony secondaries should be dealt with on their own merit. For the patient with a life expectancy of less than 6 months, internal fixation may be an adequate procedure, but for the patient with a potential of longer survival endoprosthetic replacement may prove more longlasting. For patients with massive destructive lesions and periarticular lesions, endoprosthetic replacement may be the only alternative for limb salvage, the far from ideal alternative being an amputation. For patients with tumours with a poor response rate to radiotherapy, such
18
D Chan et al.
as hypernephroma, endoprosthetic replacement with complete resection of the tumour is more reliable than complex osteosynthesis.
8 9
References 10 I Bremner RA, Jelliffe AM. The management of pathological fracture of the major long bones from metastatic cancer. J Bone joint Surg 1958;40B:652-9. 2 Parrish FF, Murray JA. Surgical treatment for secondary neoplastic fractures. A retrospective study of ninety-six patients. J Bone joint Surg 1970;52A:665-86. 3 Galasko CSB. Pathological fractures secondary to metastatic cancer. J R Coll Surg Edinb 1974;19:351-62. 4 Harrington KD. New trends in the management of lower extremity metastases. Clin Orthop 1982;169:53-61. 5 Habermann ET, Sachs R, Stern RE, Hirsh DM, Anderson WJ. The pathology and treatment of metastatic disease of the femur. Clin Orthop 1982;169:70-82. 6 Habermann ET, Lopez RA. Metastatic disease of bone and treatment of pathological fractures. Orthop Clin North Am
1989;20:469-86. 7 Harrington KD, Sim FH, Enis JE, Johnston JO, Dick HM, Gristina AG. Methylmethacrylate as an adjunct in
11
12
13 14
15
internal fixation of pathological fractures. J Bone joint Surg 1976;58A: 1047-55. Ritschl P, Kotz R. Prosthetic implants in bone metastases of the lower limb. Ann Chir Gynaecol 1987;76: 159-62. Keating JF, Burke T, Macauley P. Proximal femoral replacement for pathological fracture. Injury 1990;21: 231-3. Burrows HJ, Wilson JN, Scales JT. Excision of tumours of humerus and femur, with restoration by internal prostheses. J Bone joint Surg 1975;57B: 148-59. Enneking WF, Spanier SS, Goodman MA. A system for the surgical staging of musculoskeletal sarcoma. Clin Orthop 1980;153: 106-20. Kaplan EL, Meier P. Non-parametric estimation from incomplete observations. J Am Stat Assoc 1958;53 :457-86. Swanson DA, Orovan WL, Johnson DE, Giacco G. Osseous metastases secondary to renal cell carcinoma. Urology 1981;18:556-61. Pongracz N, Zimmerman R, Kotz R. Orthopaedic management of bony metastases of renal cancer. Semin Surg Oncol 1988;4: 139-42. Ljungberg B, Roos G, Toolanen G. Tumour DNA content and skeletal metastases in renal cell carcinoma. J Bone Joint Surg 1990;72B: 111-15.
Received 3 May 1991
Assessor's comment This is a timely paper describing 38 patients who have undergone resection and endoprosthetic replacement for metastases of the appendicular skeleton. There are several indications for endoprosthetic replacement in patients with multiple skeletal metastases. This is indicated in patients with a solitary metastasis, usually secondary to a hypernephroma. The solitary metastasis is resected with the aim of achieving a wide margin of healthy tissue around the tumour. Endoprosthetic replacement is also indicated in patients with transcervical femoral fractures secondary to skeletal metastases. These fractures do not unite, irrespective of the degree of displacement or the type of treatment, presumably because of the effect of irradiation on an area that already has a poor blood supply. The type
of endoprosthesis depends on the extent of metastatic spread. Endoprosthetic replacement is also required where surgical fixation of the pathological fracture is not feasible; for example pathological fractures of the humeral neck are best treated by endoprosthetic replacement, the type of prosthesis depending on the extent of local tumour dissemination. Finally, endoprosthetic replacement may be indicated where previous fixation of a fracture, or impending fracture has failed. C S B GALASKO ChM FRCS Professor of Orthopaedic Surgery Hope Hospital Salford
Endoprosthetic replacement for bony metastases D Chan FRCSEd Orthopaedic Registrar
S R Carter
FRCS
Senior Orthopaedic Registrar
R J Grimer
FRCS FRCSEd(Orth)
Consultant Orthopaedic Surgeon
R S Sneath
FRCS
Director, Bone Tumour Treatment Service
The Bone Tumour Treatment Service, Royal Orthopaedic Hospital, Birmingham
Key words: Bone neoplasm; Bone metastasis; Pathological fractures; Endoprosthesis
A series of 38 patients with long bone metastases treated at the Birmingham Bone Tumour Treatment Service with resection of the metastatic lesion and replacement of the bone defect with an endoprosthesis was reviewed. The majority of cases had pathological fractures due to a massive destructive lesion. Two-thirds of the patients had a solitary metastasis. Metastases from hypernephroma and breast carcinoma accounted for the majority of cases. All the patients were independently mobile after the endoprosthetic replacement and were pain free. The average survival rate after the endoprosthetic replacement was 14.7 months and this varies with the primary tumour. The indications for endoprosthetic replacement for the treatment of long bone metastases are outlined and the results and complications are discussed. It is concluded that endoprosthetic replacement for bony metastases is an effective palliative procedure for a selected group of patients.
within the patient's expected lifespan. There have been numerous methods described for achieving these aims (4-7). These involve the use of internal fixation with or without methyl methacrylate augmentation or the use of conventional prostheses. In selected cases, resection and endoprosthetic replacement of part of the involved bone may fulful these aims and may have advantages over other methods of fixation or stabilisation of a bony defect. Endoprosthetic replacement with custom made prostheses have been described in a number of papers (8-9). These have been performed mainly for proximal femoral lesions. The role of endoprosthetic replacement has not been clearly defined. The purpose of this paper is to present our experience in the use of endoprosthetic replacement for the treatment of metastatic bone disease.
Patients and method Since the 1950s there has been an increasing trend for the aggressive and early surgical stabilisation of pathological and impending fractures (1-3). The aim of the orthopaedic surgeon is to maintain or improve the patient's quality of life by the relief of pain, the control of the local disease and the restoration of normal function to the affected limb. Chemotherapy, radiotherapy and hormonal manipulation, where applicable, may be administered to control the primary disease. The onus upon the orthopaedic surgeon is to perform procedures which will achieve these aims and allow rapid rehabilitation. Whatever surgery is contemplated should not prejudice the patient's survival or disseminate disease and it should be of sufficient durability not to fail
Correspondence to: S R Carter FRCS, Royal Orthopaedic Hospital, Woodlands, Northfield, Birmingham B31 2AP
Over the 17 years from 1972 to 1989, 131 patients were referred to the Birmingham Bone Tumour Treatment Service for advice about metastatic disease. Of this group, 42 were considered suitable for an endoprosthetic replacement. Full information was available for 38 patients. The indications for endoprosthetic replacement for long bone metastatic disease were: 1 Those patients with an anticipated survival of greater than 6 months; 2 Inability to achieve the goals of long-standing stability and good function by other methods; 3 Patient prepared to co-operate with the proposed surgical programme. 4 Failure of previous attempts at stabilisation of bone by other methods.
14
D Chan et al.
Table I. Distribution of the primary tumours Primary
Hypernephroma Breast Bronchogenic carcinoma Thyroid carcinoma Prostatic carcinoma Medulloblastoma Unknown Total
Number 15 14 3 2 1 1 2 38
Contraindications were: 1 The presence of infection at the operative site; 2 Previous radiotherapy in a dosage likely to prejudice soft tissue and wound healing; 3 The results of endoprosthetic replacement unlikely to be better than other methods of reconstruction. The age range of this group of patients was from 23 to 76.7 years, with 11 males and 27 females. The average age was 54 years. A total of 25 patients presented with a pathological fracture, ten of whom had previous internal fixation or implants which failed. Three patients subsequently developed a pathological fracture after referral to the Bone Tumour Treatment Service. The remainder presented with a painful bony lesion, seven of whom did not have a diagnosis of the primary lesion. There were 25 solitary lesions as assessed by bone scintigraphy and 13 multiple lesions. On referral, patients were assessed using staging studies to confirm the extent of the metastatic disease and the general condition of the patient. Those patients presenting with an apparently solitary lesion of bone with no obvious primary had a biopsy performed in an attempt to identify the primary malignancy. In those patients with an untreated primary, advice was sought from appropriate colleagues. Those patients who were thought to be suitable for endoprosthetic replacement had a custom made endoprosthesis manufactured at the Department of Biomedical Engineering of the Royal National Orthopaedic Hospital in London according to previously described methods (10).
Table II. Distribution of the sites of endoprosthetic replacements Site Proximal femur Distal femur Proximal humerus Distal humerus Proximal tibia Total One patient had three endoprostheses Three patients had two endoprostheses
Surgery was performed using oncological principles, the tumour was resected with the aim of achieving a wide margin with a layer of healthy tissue covering the tumour (11). The resected bone was then replaced by the custom made endoprosthesis. All the prostheses were cemented. The knee and elbow joints were constrained hinge joints. Appropriate adjuvant therapy for metastases from breast, prostate and follicular carcinoma of the thyroid was used as appropriate, but local radiotherapy was not required after the resection. The sites of the primary tumour are shown in Table I, and the sites of the endoprosthetic replacements are shown in Table II. A total of 43 endoprostheses were inserted in these 38 patients. One patient received three endoprostheses and three patients received two endoprostheses. The cumulative survival curves were constructed using the method described by Kaplan and Meier (12).
Results of the method for treatment of metajust by assessing the survival of the patients but by determining that the endoprosthetic replacement achieved its aims of maintaining function and providing pain relief while allowing the patient to lead as normal a lifestyle as possible. The patients were able to have reasonable function of their limb, but such a retrospective study does not allow a functional score to be determined. All patients were able to regain independent mobility. It is recognised that endoprosthetic function improves after surgery for a considerable period, some patients did not achieve maximum function or benefit due to their shortened lifespan. In all patients pain was reduced or completely relieved by the insertion of an endoprosthetic replacement.
The
assessment stases was not
Survival rates The survival rate of the 22 patients who have died after endoprosthetic replacement is shown in Table III. One patient who died perioperatively from bronchopneumonia was excluded from the calculations.
Table III. Survival rates after endoprosthetic ment (months)
replace-
Number
Primary
Mean
Median
Range
SD
28
Overall Kidney
14.7 20.7 14.2 3.9 13.3 10.3 19.5 8.7
7.9 13.1 5.9 3.6
2.5-70.2 6.9-70.2 2.7-56.1 2.5- 5.7
17.4 20.8 17.4 1.3
10.3 6.3
2.5-70.2 2.7-25.7
21.5
S 7 2 1 43
Breast
Lung Prostate Brain
Solitary Multiple
7.0
Endoprosthetic replacement for bony metastases At the time of writing, 16 patients were still alive. Four patients with breast metastases are still alive at an average of 7.1 months (range 1.5-16.3 months) after the procedure. Eight patients with hypernephroma metastases are still alive at an average 25.8 months (range 3.5-53.4 months) after the procedure. The two patients with thyroid metastases are both alive at 32.4 months and 84.1 months. The two patients with metastases from an unknown primary are alive at 4.6 and 8.5 months. The cumulative survival curves showing the survival time from surgery in these patients are shown in Fig. 1, with cumulative survival curves of the main primary groups superimposed. A separate cumulative survival graph is constructed for solitary and multiple lesions in Fig. 2.
Complications None of the patients had significant loosening of the endoprosthetic replacement requiring a revision procedure. Two patients developed wound infections and one a lateral popliteal nerve palsy. There was no evidence
All patients *
15
of deep infection. The implant failed in two patients and dislocated in four patients. One of the implant failures occurred in a patient treated early in the series. He had a long-stem Charnley prosthesis inserted for a proximal femoral metastasis from a prostatic primary. This bent into varus and had to be replaced by a custom made endoprosthesis. Since this experience, all the patients have received a custom made endoprosthetic replacement. The other patient with an implant failure had a distal humeral replacement for a hypernephroma metastasis. The polyethylene bearings of the elbow hinge became worn out after 4 years, these were replaced. Shortly afterwards the patient sustained a fracture of the ulnar component of the prosthesis which required further revision surgery. Dislocation of the endoprosthetic replacement occurred in four patients, all of whom had proximal femoral replacements. The dislocations were recurrent in three patients. The patient with the long-stem Charnley prosthesis dislocated this prosthesis three times. One patient dislocated his endoprosthesis twice, while the remaining patient dislocated his endoprosthesis three times. This was almost invariably due to generalised debility and weak muscle tone restricting the ability of the patient to contain their artificial hip joint. The dislocations were all reduced by closed methods and revision surgery was not carried out as the dislocations had been infrequent.
lung
---*.. Hypernephroma O----0-- Breast
Months
Figure 1. Cumulative survival curves according to the primary tumours.
1001
Percentage Survival
90
II II
80
II
II
70
---
II
60-
.W--
Multiple
Solitary
8I II II
II
50
II
II
40
II
L
11
30 1.11
U-1811
20
II
I
10
11I
0I
A
0
20
40
60
80
100
Months Figure 2. Cumulative survival curves of solitary versus multiple
metastases.
( a)
(') Figure 3. (a) A large lytic lesion of the distal femur. (b) Treatment by replacement with a distal femoral endoprosthesis.
16
D Chan et al.
Discussion We have reviewed endoprosthetic replacements of bone in a group of patients with bony metastases where conservative methods of stabilising the skeleton with conventional implants with or without cement would not have provided local tumour control whilst maintaining function. This was particularly the case where the metastatic lesion was extensive (Fig. 3) or when it extended up to a joint surface (Fig. 4). Gross destructive lesions in the trochanteric and cervical regions of the femur make conventional prosthetic replacement impossible. It is in these situations where complex osteosynthesis, even with cement augmentation, is unlikely to lead to long-lasting stability and where an endoprosthetic replacement finds its true role. Complex osteosynthesis after intralesional excision of the metastasis requires adjuvant local treatment such as radiotherapy to prevent local recurrence. The inadequately fixed pathological fracture remains painful and often will not unite after radiotherapy. Some patients, notably those with hypernephroma metastases and breast, do survive for a long time after the development of bony metastases. This likelihood of a prolonged survival is often unpredictable for the individual patient and as a result the patient may have a life span greater than the internal fixation device inserted, particularly if
non-union or local recurrence occurs (Fig. 5). Metastases with poor response rate to radiotherapy are better treated with endoprosthetic replacement (Fig. 6). Endoprosthetic replacement allows complete local resection of the tumour and obviates the need for postoperative radiotherapy. In the patient with a compromised life expectancy, the use of a cemented endoprosthesis allows immediate stable fixation and rapid postoperative mobilisation. Osseous integration of an uncemented prosthesis may be compromised by the catabolic state of the patient. We have made use of custom made endoprostheses in this series but the current availability of modular systems commercially (8) which can be obtained at very short notice may make this type of implant more appropriate for these patients. There is no doubt that an endoprosthesis is more expensive than other possible methods of treatment but the short period of hospitalisation and the stability and durability of the fixation with the lack of major complications should mitigate against this.
I. (a)
JJ)
Figure 4. (a) A distal humeral pathological fracture from a breast carcinoma extending to the articular surface. (b) Resection of the pathological fracture and replacement with a distal humeral endoprosthesis.
(b) (a) Figure 5. (a) A pathological mid-shaft femoral fracture due to a metastasis from a hypernephroma treated with an interlocking intramedullary nail and acrylic cement augmentation failed after 2 years due to local recurrence. (b) Treatment with resection and proximal femoral endoprosthetic replacement.
Endoprosthetic replacement for bony metastases
(a)
(b)
4._
(c)
(d)
Figure 6. (a) A lytic hypernephroma metastasis of the humeral shaft. (b) Treated with Rush nailing and radiotherapy. (c) The tumour was not sensitive to radiotherapy; (d) had to be resected and replaced with a proximal humeral endoprosthesis.
Our results confirm that patients with bony metastases have a capacity to survive a relatively long time. It is our impression, and others have confirmed (13-15), that some patients with metastatic hypernephroma enjoy prolonged survival and indeed some may be considered free of disease. Patients with solitary bony lesions at diagnosis also have longer survival than patients with multiple lesions. At presentation, 26 patients had a solitary bony metastasis and nine patients had evidence of more than one bony metastasis. The average survival of these patients with multiple metastases was 8.7 months, while the average survival for those with a solitary metastasis was 19.5 months. Although it is attractive to entertain the idea of a curative resection for patients with a solitary metastasis it seems that these patients may simply be selected at an earlier stage in their disease. In the group of patients who presented with a solitary metastasis, 11 eventually died with further metastases. Of the remaining patients, five patients had subsequently developed further metastases. It is possible that a patient presenting with a solitary bony metastasis may have multiple undetected micrometastases.
Our patients with metastases from a bronchogenic carcinoma had uniformly low survival rates. This has also been noted by other authors (2,5). It is possible that these tumours are much more aggressive and are at a more advanced stage when they metastasise. We consider that most patients with bony metastases from bronchogenic carcinomas will not be suitable candidates for endoprosthetic replacement. In conclusion, many patients with bony metastatic disease survive a reasonable length of time if given adequate treatment, both for the primary and for the secondary tumour. The mere discovery of a bony metastasis should not be considered a preterminal event. The bony secondaries should be dealt with on their own merit. For the patient with a life expectancy of less than 6 months, internal fixation may be an adequate procedure, but for the patient with a potential of longer survival endoprosthetic replacement may prove more longlasting. For patients with massive destructive lesions and periarticular lesions, endoprosthetic replacement may be the only alternative for limb salvage, the far from ideal alternative being an amputation. For patients with tumours with a poor response rate to radiotherapy, such
18
D Chan et al.
as hypernephroma, endoprosthetic replacement with complete resection of the tumour is more reliable than complex osteosynthesis.
8 9
References 10 I Bremner RA, Jelliffe AM. The management of pathological fracture of the major long bones from metastatic cancer. J Bone joint Surg 1958;40B:652-9. 2 Parrish FF, Murray JA. Surgical treatment for secondary neoplastic fractures. A retrospective study of ninety-six patients. J Bone joint Surg 1970;52A:665-86. 3 Galasko CSB. Pathological fractures secondary to metastatic cancer. J R Coll Surg Edinb 1974;19:351-62. 4 Harrington KD. New trends in the management of lower extremity metastases. Clin Orthop 1982;169:53-61. 5 Habermann ET, Sachs R, Stern RE, Hirsh DM, Anderson WJ. The pathology and treatment of metastatic disease of the femur. Clin Orthop 1982;169:70-82. 6 Habermann ET, Lopez RA. Metastatic disease of bone and treatment of pathological fractures. Orthop Clin North Am
1989;20:469-86. 7 Harrington KD, Sim FH, Enis JE, Johnston JO, Dick HM, Gristina AG. Methylmethacrylate as an adjunct in
11
12
13 14
15
internal fixation of pathological fractures. J Bone joint Surg 1976;58A: 1047-55. Ritschl P, Kotz R. Prosthetic implants in bone metastases of the lower limb. Ann Chir Gynaecol 1987;76: 159-62. Keating JF, Burke T, Macauley P. Proximal femoral replacement for pathological fracture. Injury 1990;21: 231-3. Burrows HJ, Wilson JN, Scales JT. Excision of tumours of humerus and femur, with restoration by internal prostheses. J Bone joint Surg 1975;57B: 148-59. Enneking WF, Spanier SS, Goodman MA. A system for the surgical staging of musculoskeletal sarcoma. Clin Orthop 1980;153: 106-20. Kaplan EL, Meier P. Non-parametric estimation from incomplete observations. J Am Stat Assoc 1958;53 :457-86. Swanson DA, Orovan WL, Johnson DE, Giacco G. Osseous metastases secondary to renal cell carcinoma. Urology 1981;18:556-61. Pongracz N, Zimmerman R, Kotz R. Orthopaedic management of bony metastases of renal cancer. Semin Surg Oncol 1988;4: 139-42. Ljungberg B, Roos G, Toolanen G. Tumour DNA content and skeletal metastases in renal cell carcinoma. J Bone Joint Surg 1990;72B: 111-15.
Received 3 May 1991
Assessor's comment This is a timely paper describing 38 patients who have undergone resection and endoprosthetic replacement for metastases of the appendicular skeleton. There are several indications for endoprosthetic replacement in patients with multiple skeletal metastases. This is indicated in patients with a solitary metastasis, usually secondary to a hypernephroma. The solitary metastasis is resected with the aim of achieving a wide margin of healthy tissue around the tumour. Endoprosthetic replacement is also indicated in patients with transcervical femoral fractures secondary to skeletal metastases. These fractures do not unite, irrespective of the degree of displacement or the type of treatment, presumably because of the effect of irradiation on an area that already has a poor blood supply. The type
of endoprosthesis depends on the extent of metastatic spread. Endoprosthetic replacement is also required where surgical fixation of the pathological fracture is not feasible; for example pathological fractures of the humeral neck are best treated by endoprosthetic replacement, the type of prosthesis depending on the extent of local tumour dissemination. Finally, endoprosthetic replacement may be indicated where previous fixation of a fracture, or impending fracture has failed. C S B GALASKO ChM FRCS Professor of Orthopaedic Surgery Hope Hospital Salford
