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Severe Metallosis Owing to Intraprosthetic Dislocation in a Failed Dual-Mobility Cup Primary Total Hip Arthroplasty
The Journal of Arthroplasty Vol. 27 No. 3 2012
Case Report
Severe Metallosis Owing to Intraprosthetic Dislocation in a Failed Dual-Mobility Cup Primary Total Hip Arthroplasty Riazuddin Mohammed, MS Ortho, MRCS, and Peter Cnudde, MD
Abstract: We report a case of extensive metallosis owing to an intraprosthetic dislocation of a dual-mobility cup after a primary total hip arthroplasty. A 70-year-old man was referred to us from another center with a painful right hip 3 years after the arthroplasty. Initial investigations were suspicious of osteolysis secondary to metallosis with the characteristic “bubble sign” visualized on plain radiographs. At the revision procedure, widespread black staining of soft tissues and bone was noted. The polyethylene liner had dislodged leading to erosion of the metal socket by the prosthetic head. Histopathology examination of periprosthetic tissue confirmed metallosis. To our knowledge, this is the first reported case of severe metallosis owing to a known complication of dual-mobility sockets. Keywords: dual-mobility socket, metallosis, intraprosthetic dislocation, bubble sign. © 2012 Elsevier Inc. All rights reserved.
The dual-mobility cup incorporates a prosthetic head mobile within a retentive polyethylene liner, which itself is free to move in a metal-backed cup. Bosquet, in 1976, is first credited to have developed the concept of dual mobility [1]. The main advantage seems to be its usefulness in patients with high risk of postoperative instability. The dislocation rates in primary arthroplasty range from 0% to 0.22% [2-5], and in revision arthroplasty, from 1.1% to 3.7% [6-8]. One of the common medium-term complications of the dualmobility system is “intraprosthetic” dislocation. The head comes out of the polyethylene insert and lodges itself in the metal shell. Direct articulation between the prosthetic head with the metal socket can generate significant amounts of metal debris to cause metallosis. We describe a case of intraprosthetic dislocation of a dual-mobility cup, leading to extensive metallosis,
From the Hywel Dda NHS Trust, West Wales General Hospital, Carmarthen, United Kingdom. Submitted March 7, 2010; accepted April 11, 2011. The Conflict of Interest statement associated with this article can be found at doi:10.1016/j.arth.2010.11.019. Reprint requests: Riazuddin Mohammed, SpR Trauma and Orthopaedics, Hywel Dda NHS Trust, West Wales General Hospital, Carmarthen, SA31 2AF, United Kingdom. © 2012 Elsevier Inc. All rights reserved. 0883-5403/2703-0026$36.00/0 doi:10.1016/j.arth.2010.11.019
which to our knowledge has not been reported so far in English literature.
Case Report A 70-year-old man had a dual-mobility right primary hybrid total hip arthroplasty performed minimally invasive through modified lateral approach 3 years ago in France. A fully polished cemented modular stem (Wright Medical Technology, Arlington, Tenn) size 3, with a 28-mm cobalt chromium alloy head, and an uncemented Apogee dualmobility titanium alloy cup (Biotechni®, La Ciotat, France) measuring 52 mm were used. After an asymptomatic period for the initial 18 months, he started to develop insidious onset right hip pain. The patient then presented with sudden hip pain, give away sensation, and followed up a few weeks later with redness in the groin. The hematology and biochemistry profile was normal. Plain anteroposterior (Fig. 1) and lateral radiographs revealed an eccentric location of his prosthetic head in the metal socket, abnormal position of the polyethylene liner, osteolysis, and presence of Brooker grade 3 heterotopic ossifications. Despite the marked ectopic bone formation, the patient was not troubled with any significantly reduced range of motion. The flexion of the hip with the knee joint flexed was 90°, and there was no fixed flexion deformity in the hip. Rotation movements were present but limited because of pain. Abduction was restricted to 30°, and adduction was possible up to 30°.
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493.e2 The Journal of Arthroplasty Vol. 27 No. 3 March 2012
Fig. 3. Retrieved prosthesis showing full-thickness erosion of the metal socket and scuffing of the polyethylene liner. Fig. 1. Anteroposterior radiograph of pelvis showing eccentric position of prosthetic head and abnormal position of polyethylene liner.
Computed tomographic images (Fig. 2) revealed a large cyst measuring 71 mm by 36 mm and extending in the region of the iliopsoas muscle. Under ultrasound guidance, aspiration of the cyst yielded 70 mL of black fluid, which was negative for organisms. It was at this stage that further management options were sought from us. After thorough workup, a single-stage revision arthroplasty was planned and carried out. On the operative table, massive black staining of all periprosthetic soft tissues including the proximal femur was noted. There was no macroscopic evidence of infection. The metal head had dislodged from the polyethylene liner and had completely eroded through
Fig. 2. Computed tomographic image with the cyst lying in front of the hip.
the metal socket. The prosthetic head was relatively unscuffed, and minor wear was noted on the convexity of the polyethylene liner (Fig. 3). All the components were loose and easily extracted. Preparation of the acetabular socket opened the cyst revealing copious
Fig. 4. (A) Histopathology slide with chronic inflammatory tissue, foreign body giant cells, and abundant extracellular pigment material. (B) Polarized microscopy image showing positively birefringent polyethylene particles.
Severe Metallosis Owing to Intraprosthetic Dislocation Mohammed and Cnudde
amount of tar-colored fluid. A long-stem modular cemented femoral component and an uncemented metal-backed polyethylene liner were implanted. The patient made uneventful recovery. All the samples sent for microbiology were negative for infection. Histopathology examination confirmed metallosis revealing granulomatous tissue with extensive pigmented deposits and foreign body giant cells (Fig. 4A and B).
Discussion Although intended for patients with high risk of instability, dual-mobility cups seem to fail because of intraprosthetic dislocation rather than because of prosthetic joint dislocation. A high index of clinical suspicion is needed to diagnose it early and institute appropriate management to avoid complications like metallosis.
References 1. Farizon F, de Lavison R, Azoulai JJ, et al. Results with a cementless alumina-coated cup wear mobility. Int Orthop 1998;22:219.
493.e3
2. Philippot R, Farizon F, Camilleri JP, et al. Survival of dual mobility socket with a mean 17 years follow-up. Rev Chir Orthop 2008;94:43. 3. Bauchu P, Bonnard O, Cyprès A, et al. The dual-mobility POLARCUP: first results from a multicenter study. Orthopedics 2008;31(12 Suppl 2). 4. Fiquet A, Noyer D. “Polarsystem” dual mobility hip prosthesis and “minimally invasive surgery” (MIS). Int Surg 2006;22:1. 5. Lautridou C, Lebel B, Burdin G, et al. [Survival of the cementless Bousquet dual mobility cup: minimum 15-year follow-up of 437 total hip arthroplasties] Revue de chirurgie orthopédique et réparatrice de l'appareil moteur, December 2008, vol./is. 94/8(731-9), 1776. 6. Philippot R, Adam P, Reckhaus M, et al. Prevention of dislocation in total hip revision surgery using a dual mobility design. Orthop Traumatol Surg Res: OTSR 2009; 95/6:1877. 7. Guyen O, Pibarot V, Vaz G, et al. Use of a dual mobility socket to manage total hip arthroplasty instability. Clin Orthop Relat Res 2009;467/2:1528. 8. Langlais FL, Ropars M, Gaucher F, et al. Dual mobility cemented cups have low dislocation rats in THA revisions. Clin Orthop Relat Res 2008;466:389.
Case Report
Severe Metallosis Owing to Intraprosthetic Dislocation in a Failed Dual-Mobility Cup Primary Total Hip Arthroplasty Riazuddin Mohammed, MS Ortho, MRCS, and Peter Cnudde, MD
Abstract: We report a case of extensive metallosis owing to an intraprosthetic dislocation of a dual-mobility cup after a primary total hip arthroplasty. A 70-year-old man was referred to us from another center with a painful right hip 3 years after the arthroplasty. Initial investigations were suspicious of osteolysis secondary to metallosis with the characteristic “bubble sign” visualized on plain radiographs. At the revision procedure, widespread black staining of soft tissues and bone was noted. The polyethylene liner had dislodged leading to erosion of the metal socket by the prosthetic head. Histopathology examination of periprosthetic tissue confirmed metallosis. To our knowledge, this is the first reported case of severe metallosis owing to a known complication of dual-mobility sockets. Keywords: dual-mobility socket, metallosis, intraprosthetic dislocation, bubble sign. © 2012 Elsevier Inc. All rights reserved.
The dual-mobility cup incorporates a prosthetic head mobile within a retentive polyethylene liner, which itself is free to move in a metal-backed cup. Bosquet, in 1976, is first credited to have developed the concept of dual mobility [1]. The main advantage seems to be its usefulness in patients with high risk of postoperative instability. The dislocation rates in primary arthroplasty range from 0% to 0.22% [2-5], and in revision arthroplasty, from 1.1% to 3.7% [6-8]. One of the common medium-term complications of the dualmobility system is “intraprosthetic” dislocation. The head comes out of the polyethylene insert and lodges itself in the metal shell. Direct articulation between the prosthetic head with the metal socket can generate significant amounts of metal debris to cause metallosis. We describe a case of intraprosthetic dislocation of a dual-mobility cup, leading to extensive metallosis,
From the Hywel Dda NHS Trust, West Wales General Hospital, Carmarthen, United Kingdom. Submitted March 7, 2010; accepted April 11, 2011. The Conflict of Interest statement associated with this article can be found at doi:10.1016/j.arth.2010.11.019. Reprint requests: Riazuddin Mohammed, SpR Trauma and Orthopaedics, Hywel Dda NHS Trust, West Wales General Hospital, Carmarthen, SA31 2AF, United Kingdom. © 2012 Elsevier Inc. All rights reserved. 0883-5403/2703-0026$36.00/0 doi:10.1016/j.arth.2010.11.019
which to our knowledge has not been reported so far in English literature.
Case Report A 70-year-old man had a dual-mobility right primary hybrid total hip arthroplasty performed minimally invasive through modified lateral approach 3 years ago in France. A fully polished cemented modular stem (Wright Medical Technology, Arlington, Tenn) size 3, with a 28-mm cobalt chromium alloy head, and an uncemented Apogee dualmobility titanium alloy cup (Biotechni®, La Ciotat, France) measuring 52 mm were used. After an asymptomatic period for the initial 18 months, he started to develop insidious onset right hip pain. The patient then presented with sudden hip pain, give away sensation, and followed up a few weeks later with redness in the groin. The hematology and biochemistry profile was normal. Plain anteroposterior (Fig. 1) and lateral radiographs revealed an eccentric location of his prosthetic head in the metal socket, abnormal position of the polyethylene liner, osteolysis, and presence of Brooker grade 3 heterotopic ossifications. Despite the marked ectopic bone formation, the patient was not troubled with any significantly reduced range of motion. The flexion of the hip with the knee joint flexed was 90°, and there was no fixed flexion deformity in the hip. Rotation movements were present but limited because of pain. Abduction was restricted to 30°, and adduction was possible up to 30°.
493.e1
493.e2 The Journal of Arthroplasty Vol. 27 No. 3 March 2012
Fig. 3. Retrieved prosthesis showing full-thickness erosion of the metal socket and scuffing of the polyethylene liner. Fig. 1. Anteroposterior radiograph of pelvis showing eccentric position of prosthetic head and abnormal position of polyethylene liner.
Computed tomographic images (Fig. 2) revealed a large cyst measuring 71 mm by 36 mm and extending in the region of the iliopsoas muscle. Under ultrasound guidance, aspiration of the cyst yielded 70 mL of black fluid, which was negative for organisms. It was at this stage that further management options were sought from us. After thorough workup, a single-stage revision arthroplasty was planned and carried out. On the operative table, massive black staining of all periprosthetic soft tissues including the proximal femur was noted. There was no macroscopic evidence of infection. The metal head had dislodged from the polyethylene liner and had completely eroded through
Fig. 2. Computed tomographic image with the cyst lying in front of the hip.
the metal socket. The prosthetic head was relatively unscuffed, and minor wear was noted on the convexity of the polyethylene liner (Fig. 3). All the components were loose and easily extracted. Preparation of the acetabular socket opened the cyst revealing copious
Fig. 4. (A) Histopathology slide with chronic inflammatory tissue, foreign body giant cells, and abundant extracellular pigment material. (B) Polarized microscopy image showing positively birefringent polyethylene particles.
Severe Metallosis Owing to Intraprosthetic Dislocation Mohammed and Cnudde
amount of tar-colored fluid. A long-stem modular cemented femoral component and an uncemented metal-backed polyethylene liner were implanted. The patient made uneventful recovery. All the samples sent for microbiology were negative for infection. Histopathology examination confirmed metallosis revealing granulomatous tissue with extensive pigmented deposits and foreign body giant cells (Fig. 4A and B).
Discussion Although intended for patients with high risk of instability, dual-mobility cups seem to fail because of intraprosthetic dislocation rather than because of prosthetic joint dislocation. A high index of clinical suspicion is needed to diagnose it early and institute appropriate management to avoid complications like metallosis.
References 1. Farizon F, de Lavison R, Azoulai JJ, et al. Results with a cementless alumina-coated cup wear mobility. Int Orthop 1998;22:219.
493.e3
2. Philippot R, Farizon F, Camilleri JP, et al. Survival of dual mobility socket with a mean 17 years follow-up. Rev Chir Orthop 2008;94:43. 3. Bauchu P, Bonnard O, Cyprès A, et al. The dual-mobility POLARCUP: first results from a multicenter study. Orthopedics 2008;31(12 Suppl 2). 4. Fiquet A, Noyer D. “Polarsystem” dual mobility hip prosthesis and “minimally invasive surgery” (MIS). Int Surg 2006;22:1. 5. Lautridou C, Lebel B, Burdin G, et al. [Survival of the cementless Bousquet dual mobility cup: minimum 15-year follow-up of 437 total hip arthroplasties] Revue de chirurgie orthopédique et réparatrice de l'appareil moteur, December 2008, vol./is. 94/8(731-9), 1776. 6. Philippot R, Adam P, Reckhaus M, et al. Prevention of dislocation in total hip revision surgery using a dual mobility design. Orthop Traumatol Surg Res: OTSR 2009; 95/6:1877. 7. Guyen O, Pibarot V, Vaz G, et al. Use of a dual mobility socket to manage total hip arthroplasty instability. Clin Orthop Relat Res 2009;467/2:1528. 8. Langlais FL, Ropars M, Gaucher F, et al. Dual mobility cemented cups have low dislocation rats in THA revisions. Clin Orthop Relat Res 2008;466:389.