Prótesis de Bryan: 10 años de seguimiento

Complejo Hospitalario Universitario de Albacete

Introducción y objetivos:

La artrodesis cervical es el gold standard en el tratamiento de la patología discal, habiendo demostrado su seguridad y efectividad. Sin embargo, no está exenta de complicaciones.

-Pseudoartrosis-Relacionadas con el injerto-Degeneración espacio adyacente

Se han buscado alternativas entre ellas la artroplastia tipo Bryan. Vamos a ver los resultados de la Prótesis de Bryan a 10 años.

Juan Campos García, Vicente Calatayud Pérez, Arántzazu Alcázar Parra

• Sistema de estabilización.• Preparación de platillos. • Lecho labrado por fresado.

– Estabilidad.– Ajuste

Material y métodos

Resultados

Revisión de los casos intervenidos en el Complejo Hospitalario Universitario de Albacete en el año 2002

32 pacientes intervenidos

ESTUDIO RETROSPECTIVO OBSERVACIONAL

VARIABLES A ESTUDIO-EDAD-NIVEL-IDC-EVA-EVALUACIÓN RADIOLÓGICA CALCIFICACIÓN HETEROTÓPICA-COMPLICACIONES

Edad media 43 añosMujeres 20

Hombres 12 38%

63%

Distribución por sexo

Hombres Mujeres

1 nivel 25

2 niveles 7

De los 32 pacientes, se han continuado el seguimiento de 30.

Los dos pacientes que se han perdido el seguimiento:

• fallecimiento (sin relación con pat. cervical)

• desaparición durante el seguimiento

Niveles

Resultados

Niveles

1 nivel 25

2 niveles 7

C3-C4 1

C4-C5 4

C5-C6 14

C6-C7 6

1 Nivel

C4-C5-C6 2

C5-C6-C7 5

2 niveles

domingo, 5 de mayo de 13

Resultados

Niveles

1 nivel 25

2 niveles 7

C3-C4 1

C4-C5 4

C5-C6 14

C6-C7 6

1 Nivel

C4-C5-C6 2

C5-C6-C7 5

2 niveles

domingo, 5 de mayo de 13

ResultadosTamaño

0 2 4 6 8

14mm

15mm

16mm

17mm

Mujeres (n=20)

Nº pacientes

Tamaño Nº

14 8

15 7

16 4

17 1

Mujeres

Tamaño Nº

15 1

16 6

17 3

18 2

Hombres

0 1,5 3,0 4,5 6,0

15mm

16mm

17mm

18mm

Hombres (n=12)

domingo, 5 de mayo de 13

Resultados

Indice de discapacidad cervical (IDC)

Pre-operatorio=52,3

Post-operatorio=23,4

P<0,01

0

15

30

45

60

Pre-operatorioPost-operatorio

Indice discapacidad cervical (IDC)

Diferencia=23,4

domingo, 5 de mayo de 13

Resultados

Escala Visual Analógica (cervical) EVA

Pre-operatorio=6,8

Post-operatorio=3,3

P<0,01

0

1,75

3,50

5,25

7,00

Pre-operatorioPost-operatorio

ESCALA VISULA ALNALÓGICA (CERVICAL)

Diferencia=3,5

domingo, 5 de mayo de 13

Resultados

Escala Visual Analógica (MMSS) EVA

Pre-operatorio=8,2

Post-operatorio=3,5

P<0,01

0

2,25

4,50

6,75

9,00

Pre-operatorioPost-operatorio

ESCALA VISUAL ANALÓGICA (MMSS)

Diferencia=4,7

domingo, 5 de mayo de 13

Resultados

CALCIFICACIÓN HETEROTÓPICA

clinical relevance (visual analog scale [VAS] and theNeck Disability Index [NDI]) preoperatively and 1 yearpostoperatively.

Materials and Methods

Device Description. The ProDisc C prosthesis manufacturedby Synthes, Inc. (Paoli, PA), is a cervical intervertebral discprosthesis designed to permit motion comparable to the nor-mal cervical functional spinal unit. It is constructed of 2 cobalt-chrome metal endplates and a fixed ultra-high molecularweight polyethylene core that provides motion in all axes witha semi-constrained principle for flexion/extension and lateralbending (Figure 1). The ProDisc C has a fixed center of rotationclose to the superior endplate of the lower vertebral body. Pri-mary stability is provided by keels in the endplates, which fit ina chiselled slot in the cranial and caudal vertebral bodies. Theimplant comes in 6 sizes of footprints and 3 different heights (5,6, and 7 mm).27–29

Surgical Technique.30 After a standard microsurgical ante-rior approach, the midline is marked under fluoroscopic con-trol. Discectomy and decompression are performed, and thesegment is distracted and held in distraction by retaining

screws. A trial implant is inserted, and the appropriate size,height, and position of the implant are determined. The slotsfor the keels are chiselled, guided by the trial implant followedby the impaction of the implant into the prepared disc space.Bone wax to seal open bony surfaces is not used routinely.

Patients. Two centers enrolled patients for this prospectivestudy as part of a prospective European multicenter study withProDisc C: Spine Center Orthozentrum Munchen, Germany,and Department of Neurosurgery, Neurocenter Liberec, CzechRepublic.

Inclusion criteria were disc herniations or other degenera-tive changes at the levels C3/4–C6/7, which led to neurologicdeficits, and/or arm and/or neck pain. Exclusion criteria arementioned in Table 1. Surgeons with at least 5 years experiencein anterior cervical fusion performed all interventions. All pa-tients received a soft neck collar for 1–2 days after surgery.There was no specific treatment for the neck, however, patientswith neurologic deficits started with physiotherapy and electro-therapy immediately postoperatively. Patients were allowed tomove their C-Spine within a painless range. Clinical (VAS;NDI) as well as radiologic (plain radiographs, flexion/extension) controls were performed at intervals of 6 weeks, and3, 6, and 12 months postoperatively. Two of the authors (C. M.and P. B.) who had not been involved in preoperative surgicaldecision making performed all analysis.

Statistical analysis was performed using t tests and Wilcoxontests. High significance was defined as P ! 0.0001.

Classification of Heterotopic Ossification. We adapted theclassification for heterotopic ossification published by McAfeeet al23 for the lumbar spine. Table 2 presents the 5-grade scaleof severity of heterotopic ossification: grade 0 " no heterotopicossification present; grade 1 " heterotopic ossification present,

Figure 1. Original ProDisc C implant.

Figure 2. Grade 1: Heterotopic ossification is detectable, but notin the intervertebral space (in inclination).

Table 1. Exclusion Criteria for Total Cervical ArtificialDisc Replacement

- Postlaminectomy with kyphotic deformity- Translational instability- Ankylosing spondylitis, rheumatoid arthritis- Ossification of the posterior longitudinal ligament or diffuse

hyperostosis- Infection- Pregnancy- Metabolic bone diseases- Insulin-requiring diabetes mellitus- Severe osteoarthritis with lost of high of the intervertebral space of

more than 80%

Table 2. Characterisation of the Different Grades ofHeterotopic Ossification (HO) in Total Cervical DiscReplacement (modified from McAfee et al.23)

Grade 0 No HO presentGrade I HO is detectable in front of the vertebral body but not in the

anatomic interdiscal spaceGrade II HO is growing into the disc space. Possible affection of the

function of the prosthesisGrade III Bridging ossifications which still allow movement of the

prosthesisGrade IV Complete fusion of the treated segment without movement

in flexion/extension

HO indicates heterotopic ossification.

2803Heterotopic Ossification in Total Cervical Artificial Disc Replacement • Mehren et al

domingo, 5 de mayo de 13

Resultados

CALCIFICACIÓN HETEROTÓPICA

clinical relevance (visual analog scale [VAS] and theNeck Disability Index [NDI]) preoperatively and 1 yearpostoperatively.

Materials and Methods

Device Description. The ProDisc C prosthesis manufacturedby Synthes, Inc. (Paoli, PA), is a cervical intervertebral discprosthesis designed to permit motion comparable to the nor-mal cervical functional spinal unit. It is constructed of 2 cobalt-chrome metal endplates and a fixed ultra-high molecularweight polyethylene core that provides motion in all axes witha semi-constrained principle for flexion/extension and lateralbending (Figure 1). The ProDisc C has a fixed center of rotationclose to the superior endplate of the lower vertebral body. Pri-mary stability is provided by keels in the endplates, which fit ina chiselled slot in the cranial and caudal vertebral bodies. Theimplant comes in 6 sizes of footprints and 3 different heights (5,6, and 7 mm).27–29

Surgical Technique.30 After a standard microsurgical ante-rior approach, the midline is marked under fluoroscopic con-trol. Discectomy and decompression are performed, and thesegment is distracted and held in distraction by retaining

screws. A trial implant is inserted, and the appropriate size,height, and position of the implant are determined. The slotsfor the keels are chiselled, guided by the trial implant followedby the impaction of the implant into the prepared disc space.Bone wax to seal open bony surfaces is not used routinely.

Patients. Two centers enrolled patients for this prospectivestudy as part of a prospective European multicenter study withProDisc C: Spine Center Orthozentrum Munchen, Germany,and Department of Neurosurgery, Neurocenter Liberec, CzechRepublic.

Inclusion criteria were disc herniations or other degenera-tive changes at the levels C3/4–C6/7, which led to neurologicdeficits, and/or arm and/or neck pain. Exclusion criteria arementioned in Table 1. Surgeons with at least 5 years experiencein anterior cervical fusion performed all interventions. All pa-tients received a soft neck collar for 1–2 days after surgery.There was no specific treatment for the neck, however, patientswith neurologic deficits started with physiotherapy and electro-therapy immediately postoperatively. Patients were allowed tomove their C-Spine within a painless range. Clinical (VAS;NDI) as well as radiologic (plain radiographs, flexion/extension) controls were performed at intervals of 6 weeks, and3, 6, and 12 months postoperatively. Two of the authors (C. M.and P. B.) who had not been involved in preoperative surgicaldecision making performed all analysis.

Statistical analysis was performed using t tests and Wilcoxontests. High significance was defined as P ! 0.0001.

Classification of Heterotopic Ossification. We adapted theclassification for heterotopic ossification published by McAfeeet al23 for the lumbar spine. Table 2 presents the 5-grade scaleof severity of heterotopic ossification: grade 0 " no heterotopicossification present; grade 1 " heterotopic ossification present,

Figure 1. Original ProDisc C implant.

Figure 2. Grade 1: Heterotopic ossification is detectable, but notin the intervertebral space (in inclination).

Table 1. Exclusion Criteria for Total Cervical ArtificialDisc Replacement

- Postlaminectomy with kyphotic deformity- Translational instability- Ankylosing spondylitis, rheumatoid arthritis- Ossification of the posterior longitudinal ligament or diffuse

hyperostosis- Infection- Pregnancy- Metabolic bone diseases- Insulin-requiring diabetes mellitus- Severe osteoarthritis with lost of high of the intervertebral space of

more than 80%

Table 2. Characterisation of the Different Grades ofHeterotopic Ossification (HO) in Total Cervical DiscReplacement (modified from McAfee et al.23)

Grade 0 No HO presentGrade I HO is detectable in front of the vertebral body but not in the

anatomic interdiscal spaceGrade II HO is growing into the disc space. Possible affection of the

function of the prosthesisGrade III Bridging ossifications which still allow movement of the

prosthesisGrade IV Complete fusion of the treated segment without movement

in flexion/extension

HO indicates heterotopic ossification.

2803Heterotopic Ossification in Total Cervical Artificial Disc Replacement • Mehren et al

domingo, 5 de mayo de 13

Resultados

CALCIFICACIÓN HETEROTÓPICA

clinical relevance (visual analog scale [VAS] and theNeck Disability Index [NDI]) preoperatively and 1 yearpostoperatively.

Materials and Methods

Device Description. The ProDisc C prosthesis manufacturedby Synthes, Inc. (Paoli, PA), is a cervical intervertebral discprosthesis designed to permit motion comparable to the nor-mal cervical functional spinal unit. It is constructed of 2 cobalt-chrome metal endplates and a fixed ultra-high molecularweight polyethylene core that provides motion in all axes witha semi-constrained principle for flexion/extension and lateralbending (Figure 1). The ProDisc C has a fixed center of rotationclose to the superior endplate of the lower vertebral body. Pri-mary stability is provided by keels in the endplates, which fit ina chiselled slot in the cranial and caudal vertebral bodies. Theimplant comes in 6 sizes of footprints and 3 different heights (5,6, and 7 mm).27–29

Surgical Technique.30 After a standard microsurgical ante-rior approach, the midline is marked under fluoroscopic con-trol. Discectomy and decompression are performed, and thesegment is distracted and held in distraction by retaining

screws. A trial implant is inserted, and the appropriate size,height, and position of the implant are determined. The slotsfor the keels are chiselled, guided by the trial implant followedby the impaction of the implant into the prepared disc space.Bone wax to seal open bony surfaces is not used routinely.

Patients. Two centers enrolled patients for this prospectivestudy as part of a prospective European multicenter study withProDisc C: Spine Center Orthozentrum Munchen, Germany,and Department of Neurosurgery, Neurocenter Liberec, CzechRepublic.

Inclusion criteria were disc herniations or other degenera-tive changes at the levels C3/4–C6/7, which led to neurologicdeficits, and/or arm and/or neck pain. Exclusion criteria arementioned in Table 1. Surgeons with at least 5 years experiencein anterior cervical fusion performed all interventions. All pa-tients received a soft neck collar for 1–2 days after surgery.There was no specific treatment for the neck, however, patientswith neurologic deficits started with physiotherapy and electro-therapy immediately postoperatively. Patients were allowed tomove their C-Spine within a painless range. Clinical (VAS;NDI) as well as radiologic (plain radiographs, flexion/extension) controls were performed at intervals of 6 weeks, and3, 6, and 12 months postoperatively. Two of the authors (C. M.and P. B.) who had not been involved in preoperative surgicaldecision making performed all analysis.

Statistical analysis was performed using t tests and Wilcoxontests. High significance was defined as P ! 0.0001.

Classification of Heterotopic Ossification. We adapted theclassification for heterotopic ossification published by McAfeeet al23 for the lumbar spine. Table 2 presents the 5-grade scaleof severity of heterotopic ossification: grade 0 " no heterotopicossification present; grade 1 " heterotopic ossification present,

Figure 1. Original ProDisc C implant.

Figure 2. Grade 1: Heterotopic ossification is detectable, but notin the intervertebral space (in inclination).

Table 1. Exclusion Criteria for Total Cervical ArtificialDisc Replacement

- Postlaminectomy with kyphotic deformity- Translational instability- Ankylosing spondylitis, rheumatoid arthritis- Ossification of the posterior longitudinal ligament or diffuse

hyperostosis- Infection- Pregnancy- Metabolic bone diseases- Insulin-requiring diabetes mellitus- Severe osteoarthritis with lost of high of the intervertebral space of

more than 80%

Table 2. Characterisation of the Different Grades ofHeterotopic Ossification (HO) in Total Cervical DiscReplacement (modified from McAfee et al.23)

Grade 0 No HO presentGrade I HO is detectable in front of the vertebral body but not in the

anatomic interdiscal spaceGrade II HO is growing into the disc space. Possible affection of the

function of the prosthesisGrade III Bridging ossifications which still allow movement of the

prosthesisGrade IV Complete fusion of the treated segment without movement

in flexion/extension

HO indicates heterotopic ossification.

2803Heterotopic Ossification in Total Cervical Artificial Disc Replacement • Mehren et al

domingo, 5 de mayo de 13

Resultados

CALCIFICACIÓN HETEROTÓPICA

clinical relevance (visual analog scale [VAS] and theNeck Disability Index [NDI]) preoperatively and 1 yearpostoperatively.

Materials and Methods

Device Description. The ProDisc C prosthesis manufacturedby Synthes, Inc. (Paoli, PA), is a cervical intervertebral discprosthesis designed to permit motion comparable to the nor-mal cervical functional spinal unit. It is constructed of 2 cobalt-chrome metal endplates and a fixed ultra-high molecularweight polyethylene core that provides motion in all axes witha semi-constrained principle for flexion/extension and lateralbending (Figure 1). The ProDisc C has a fixed center of rotationclose to the superior endplate of the lower vertebral body. Pri-mary stability is provided by keels in the endplates, which fit ina chiselled slot in the cranial and caudal vertebral bodies. Theimplant comes in 6 sizes of footprints and 3 different heights (5,6, and 7 mm).27–29

Surgical Technique.30 After a standard microsurgical ante-rior approach, the midline is marked under fluoroscopic con-trol. Discectomy and decompression are performed, and thesegment is distracted and held in distraction by retaining

screws. A trial implant is inserted, and the appropriate size,height, and position of the implant are determined. The slotsfor the keels are chiselled, guided by the trial implant followedby the impaction of the implant into the prepared disc space.Bone wax to seal open bony surfaces is not used routinely.

Patients. Two centers enrolled patients for this prospectivestudy as part of a prospective European multicenter study withProDisc C: Spine Center Orthozentrum Munchen, Germany,and Department of Neurosurgery, Neurocenter Liberec, CzechRepublic.

Inclusion criteria were disc herniations or other degenera-tive changes at the levels C3/4–C6/7, which led to neurologicdeficits, and/or arm and/or neck pain. Exclusion criteria arementioned in Table 1. Surgeons with at least 5 years experiencein anterior cervical fusion performed all interventions. All pa-tients received a soft neck collar for 1–2 days after surgery.There was no specific treatment for the neck, however, patientswith neurologic deficits started with physiotherapy and electro-therapy immediately postoperatively. Patients were allowed tomove their C-Spine within a painless range. Clinical (VAS;NDI) as well as radiologic (plain radiographs, flexion/extension) controls were performed at intervals of 6 weeks, and3, 6, and 12 months postoperatively. Two of the authors (C. M.and P. B.) who had not been involved in preoperative surgicaldecision making performed all analysis.

Statistical analysis was performed using t tests and Wilcoxontests. High significance was defined as P ! 0.0001.

Classification of Heterotopic Ossification. We adapted theclassification for heterotopic ossification published by McAfeeet al23 for the lumbar spine. Table 2 presents the 5-grade scaleof severity of heterotopic ossification: grade 0 " no heterotopicossification present; grade 1 " heterotopic ossification present,

Figure 1. Original ProDisc C implant.

Figure 2. Grade 1: Heterotopic ossification is detectable, but notin the intervertebral space (in inclination).

Table 1. Exclusion Criteria for Total Cervical ArtificialDisc Replacement

- Postlaminectomy with kyphotic deformity- Translational instability- Ankylosing spondylitis, rheumatoid arthritis- Ossification of the posterior longitudinal ligament or diffuse

hyperostosis- Infection- Pregnancy- Metabolic bone diseases- Insulin-requiring diabetes mellitus- Severe osteoarthritis with lost of high of the intervertebral space of

more than 80%

Table 2. Characterisation of the Different Grades ofHeterotopic Ossification (HO) in Total Cervical DiscReplacement (modified from McAfee et al.23)

Grade 0 No HO presentGrade I HO is detectable in front of the vertebral body but not in the

anatomic interdiscal spaceGrade II HO is growing into the disc space. Possible affection of the

function of the prosthesisGrade III Bridging ossifications which still allow movement of the

prosthesisGrade IV Complete fusion of the treated segment without movement

in flexion/extension

HO indicates heterotopic ossification.

2803Heterotopic Ossification in Total Cervical Artificial Disc Replacement • Mehren et al

domingo, 5 de mayo de 13

CONCLUSIONES

Las últimas series de la literatura, la artroplastia tipo Bryan de un nivel tiene mejores resultados que la artrodesis cervical anterior

Resultados

CALCIFICACIÓN HETEROTÓPICA

0 8

1 6

2 7

3 4

4 3

CLASIFICACIÓN MEHREN

21=75% MÓVILES

7=25% MOVILIDAD10%

INMOVIL

domingo, 5 de mayo de 13

ResultadosComplicaciones

-2 retiradas de prótesis-Infección-Retirada al intervenir un nivel superior

domingo, 5 de mayo de 13

ResultadosComplicaciones

-2 retiradas de prótesis-Infección-Retirada al intervenir un nivel superior

domingo, 5 de mayo de 13

Conclusiones

• La artroplastia cervical es una alternativa consolidada a la artrodesis cervical anterior en el tratamiento de la patología discal cervical

domingo, 5 de mayo de 13

Conclusiones

• Los resutados de la serie son comparables a los resultadados de la literatura, tanto desde el punto de vista clínico como funcional, pero en series con menor seguimiento (2 y 4 años)

“Clinical results and development of heterotopic ossification in total cervical disc replacement during a 4-year follow-up”; Petr Suchomel et all. Eur Spine J (2010) 19:307–315

domingo, 5 de mayo de 13

Conclusiones

0

15

30

45

60

Pre-op 3 6 10

Evolución clínica (IDC)

domingo, 5 de mayo de 13

Conclusiones

74

76

78

80

82

1 3 5 7 10

Movilidad (%)

domingo, 5 de mayo de 13

LOS RESULTADOS CLÍNICOS Y LA MOVILIDAD SE MANTIENEN A PARTIR DEL PRIMER