|
Percutaneous cementoplasty of acetabular bony metastasis
J.A. Harty
D. Brennan
S. Eustace
J.O’Byrne
Department of Orthopaedic Surgery,
Department of Radiology, Mater
Misericordiae Hospital, Ireland
Correspondence to: Paul-na-curra, Glanmire Cork, Ireland
Keywords: Cementoplasty, acetabulum, metastases,
percutaneous, methylmethacrylate
Surg J R Coll Surg Edinb Irel., 1 February 2003, 48-50
The development of malignant lesions in the acetabulum can lead to painful and disabling bone destruction. Lytic metastases of the acetabulum are frequent, causing pathologic fractures, pain and disability. The literature is sparse in relation to the exact indications and technique for this procedure. Percutaneous injection of methylmethacrylate or ethanol may provide marked pain relief or bone strengthening in patients, with malignant acetabular destruction, who are unable to tolerate surgery. Injection of methylmethacrylate is usually indicated when the weight-bearing part of the acetabulum is involved. The goals of treatment are pain relief and mechanical strengthening of the acetabulum. Radiography and computed tomography must be performed prior to therapeutic percutaneous injection to assess the location and extent of the lytic process, the presence of cortical destruction or fracture, and the presence of soft-tissue involvement. We report a case of a 39-year-old woman with a secondary acetabular lesion, which was treated successfully with percutaneous acetabular cementoplasty. We describe a novel technique used to inject cement into the lesion, allowing for greater cement volume and pressurisation within the lesion
CASE REPORT
A 39-year-old woman presented with a two-week history of inability to weight
bear on her left hip, with severe
associated pain. On examination the patient was unable to weight bear on the left side. Passive
movement of her left hip revealed marked pain on movement in all directions. The patient was
unable to perform an active range of
movement due to pain limitations. There was no evidence of a shortened or abnormally rotated
limb. Peripheral neuro-vascular examination was normal. Systemic examination was also
normal. There was no past medical history of note. Plain radiography revealed a lytic lesion
in the superior surface of the left acetabulum. A full blood count, erythrocyte sedimentation
rate, and serum biochemistry were normal.
A total-body nuclear bone scan revealed an isolated focal hot spot in the left acetabulum (Figure 1). Computed tomography (CT) of the left acetabulum and pelvis demonstrated a lytic lesion in the left acetabulum measuring 3 x 2.5cm (Figure 2). A large 6.5 x 5cm adnexal mass arising from the left ovary was also seen in the pelvic cavity. There was evidence of metastases within the pelvic cavity. This was biopsied under CT guidance. Ultrasound of the liver revealed evidence of distant metastasis. In consultation between the Orthopaedic, Gynaecology and Oncology services, minimally invasive management of the acetabular lesion was decided upon.
Figure 1: Bone scan showing increased uptake in the left acetabulum
Figure 2: CT scan showing lesion involving posterior acetabular column, fracture easily visible
Following failed pain relief with radiotherapy to the acetabular lesion, the patient was brought to theatre where a general anaesthetic was administered. The patient was placed supine on a radiolucent table. A 1.5cm longitudinal incision was made over the supero-lateral margin of the acetabulum. A wire was passed into the lesion under fluoroscopic guidance (Figure 3). Following this, a cannulated drill was used to widen the opening into the superolateral wall of the acetabulum. A large bone cannulated tube (similar to that used for injection of cement into the femur in a total hip replacement) was passed over the guide wire (Figure 4). Polymethylmethacrylate cement (palacos) was mixed with phenol and injected into the lesion. The wide bore of the cement gun allowed for larger volume of cement to be injected into the lesion and for a significantly greater pressurisation of the cement, thus, increasing the structural support of the polymethylmethacrylate. There was no evidence of intra-articular leakage of the cement. The wound was closed with 3/0 nylon, and the patient was commenced on prophylactic antibiotics for 48 hours.
Figure 3: Lytic lesion in the left acetabulum
Figure 4: Cement injected lesion
Figure 5: Post-operative radiograph of hip; cement in situ
Post-operatively, the patient was pain free at 48 hours, and began partial weight bearing at 72 hours. The patient was discharged at one week post-operatively, and she began walking unaided at 10 days. Outpatient follow-up revealed further aggressive pelvic metastases, however, the patient remained pain-free and was able to perform all her activities of daily living.
DISCUSSION
Acetabular lytic lesions may be extremely painful entities which severely limit patients.
Traditional treatments involve high dose
opiates, chemotherapy and radiotherapy.2,3
In some instances radical resection of the lesion, acetabular reconstruction and total hip
replacement have been performed. In cases where poor outcome prognosis is expected, a less severe
alternative is acetabular cementoplasty.
Percutaneous injection of methylmethacrylate or phenol may provide marked pain relief or bone strengthening in patients with malignant acetabular osteolysis who are unable to tolerate surgery. Injection of methylmethacrylate is usually indicated when osteolysis involves the weight-bearing part of the acetabulum.1,2 Phenol and methylmethacrylate injections may be performed together if both weight-bearing and nonweight-bearing parts of the acetabulum are involved or extensive soft-tissue involvement is present.1,4 Moreover, these injections may be performed prior to radiation therapy, which complements their action due to similar but delayed effects on pain, or after radiation therapy that failed to relieve pain or in cases of local recurrence.4 Fever and transitory worsening in pain may occur secondary to inflammatory reaction in the hours following injection; however, these side-effects usually resolve spontaneously within one to three days. Exacerbation of pain may occur due to leakage of cement into the joint surface, and pre-operative arthrography may help to delineate any communication in the joint. Extrusion of the cement posteriorly may lead to irritation of the sciatic nerve.
The decision to perform therapeutic percutaneous injections should be made by a multidisciplinary team, because the choice between this option and alternative methods of treatment depends on several factors including the location of the lesion, the local and general extent of the disease, the pain and functional disability experienced by the patient, and the patient’s state of health and life expectancy. In carefully selected patients where the cortex still provides a sufficient barrier protecting the joint, percutaneous injection of cement (10-15mls.) can be a successful means of countering both pain and functional impairment. This easy-to-perform technique requires only local anaesthesia and can be highly cost-effective. The analgesic effect is rapid. In this case, we inserted a guide wire into the lesion under fluoroscopic control, which allowed us to drill over the wire using a cannulated drill piece. This enlarged the original aperture and permitted the insertion of a standard cement gun (approx. 1cm in diameter). The use of this technique permits injection of far greater volumes of cement in comparison with standard techniques. In previously described series, a wide bore needle was used and cement injected using standard syringes. However, the viscosity of polymethylmethacrylate precludes injection of large volumes of cement. Furthermore, the narrow diameter of the needle and the poor pressurisation properties of a standard syringe technique inhibit the cement from adequate pressurisation within the acetabular wall. The wider bore of the standard femoral cement gun easily surmounts these problems. The greater pressurisation increases the interdigitisation of the cement within the bony architecture and improves the mechanical integrity of the lesion. Most patients are able to walk again within one to five days (an effect which is particularly spectacular in bedridden subjects) probably due to the reduced pain and to better distribution of the mechanical forces. Hospitalisation is usually shortened.
REFERENCES
1. Cotten, A, Demondion, X, Boutry, N, Corter, B, Chastanet, P, Duquesnoy, B,
Leblond D. Therapeutic percutaneous injections in the treatment of malignant acetabular osteolyses. Radiographics
1999; 19 (3): 647-53
2. Cotten, A, Deprez, X, Migaud, H, Chabanne, B, Duquesnoy, B,
Chastanet, P. Malignant acetabular
osteolyses: percutaneous injection of acrylic bone cement. Radiology 1995;
197(1): 307-10
3. Cotten, A, Duquesnoy, B.
Percutaneous cementoplasty for malignant
osteolysis of the acetabulum. Presse Med 1995; 24(28): 1308-10
4. Weill, A, Kobaiter, H, Chiras, J. Acetabulum malignancies: technique and impact on pain of percutaneous
injection of acrylic surgical cement. Eur Radiol 1998; 8(1): 23-129
Copyright: 26 February 2002