Managing Bone Loss Revision Knee surgery

Worse than you think

Anderson Orthopaedic Research Institute (AORI) Type-1 - Intact metaphyseal bone with minor defects which will not compromise the stability of a revision component. Type-1 - Intact metaphyseal bone with minor defects which will not compromise the stability of a revision component.

Anderson Orthopaedic Research Institute (AORI) Type-2 - Damaged metaphyseal bone. Loss of cancellous bone in the metaphyseal segment Type-2 - Damaged metaphyseal bone. Loss of cancellous bone in the metaphyseal segment Defects can occur in one femoral condyle or tibial plateau (2A) or in both condyles or plateaux (2B). Defects can occur in one femoral condyle or tibial plateau (2A) or in both condyles or plateaux (2B).

T2 and F2

Anderson Orthopaedic Research Institute (AORI) Type-3 - Deficient metaphyseal bone. Bone loss which comprises a major portion of either condyle or plateau. Type-3 - Deficient metaphyseal bone. Bone loss which comprises a major portion of either condyle or plateau. These defects are occasionally associated with detachment of the collateral or patellar ligaments These defects are occasionally associated with detachment of the collateral or patellar ligaments

Type 3

Options a) the use of cement, either alone or combined with screws and mesh a) the use of cement, either alone or combined with screws and mesh b) bone grafting b) bone grafting with structural or morsellised graft. with structural or morsellised graft. c) modular augmentation of the components with wedges or blocks of metal c) modular augmentation of the components with wedges or blocks of metal d) Metaphyseal Sleeves d) Metaphyseal Sleeves d) the use of custom-made, tumour or hinge implants d) the use of custom-made, tumour or hinge implants

Radnay CS, Scuderi GR. Management of bone loss: augments, cones, offset stems. Clin Orthop 2006;446:83–92

Cement Performs poorly in the long term. Performs poorly in the long term. In isolation should be reserved for AORI type-1 defects, small type-2 defects of less than 5 mm or those which involve less than a quarter of the cortical rim. In isolation should be reserved for AORI type-1 defects, small type-2 defects of less than 5 mm or those which involve less than a quarter of the cortical rim. It remains a good option in the short term and may be suitable for elderly or infirm patients It remains a good option in the short term and may be suitable for elderly or infirm patients

Cement and screws For bone defects of more than 5 mm has given excellent results at 13 years with no failures. For bone defects of more than 5 mm has given excellent results at 13 years with no failures. Ritter MA, Keating EM, Faris PM. Screw and cement fixation of large defects in total knee arthroplasty: a sequel. J Arthroplasty 1993;8:63–5 Ritter MA, Keating EM, Faris PM. Screw and cement fixation of large defects in total knee arthroplasty: a sequel. J Arthroplasty 1993;8:63–5

Bone Graft Allows the augmentation of the residual bone stock. Allows the augmentation of the residual bone stock. contour the graft at operation contour the graft at operation capacity of the graft to transfer load in a physiological manner are significant advantages. capacity of the graft to transfer load in a physiological manner are significant advantages. The disadvantages The disadvantages unpredictable union, the theoretical transmission of viral, bacterial and prion disease unpredictable union, the theoretical transmission of viral, bacterial and prion disease Delloye C, Cornu O, Druez V, Barbier O. Bone allografts: what they can offer and what they cannot. J Bone Joint Joint Surg [Br] 2007;89-B:574–80.

Bone Graft Structural Structural Success has been achieved with smaller bone defects, whether centrally contained or peripherally uncontained Success has been achieved with smaller bone defects, whether centrally contained or peripherally uncontained For large defects, has shown variable early results, with reports of nonunion and collapse of the graft because of resorption. For large defects, has shown variable early results, with reports of nonunion and collapse of the graft because of resorption. The management of bone loss in revision total knee replacement J. P. Whittaker, R. Dharmarajan, A. D. Toms JBJS Vol 90-B, Issue 8,

Bone Graft Morsellised Morsellised

Whiteside 2006 CORR 446, May 2006, pp Excellent results using morsellised graft, even in the presence of type-3 cortical defects 105 patients with a follow-up of between five and ten years, with uncemented long- stemmed implants.

The combination of morsellised graft and a long stem engaging the distal cortex Causes a decrease in loading of the graft by up to 38%. Causes a decrease in loading of the graft by up to 38%. Stern et al in a biomechanical study, Stern et al in a biomechanical study, longer stem tibial implants were associated with increased micro-movement of the tibial tray. longer stem tibial implants were associated with increased micro-movement of the tibial tray. Stern SH, Wills RD, Gilbert JL. The effect of tibial stem design on component micromotion in knee arthroplasty. Clin Orthop 1997;345:44–52

Metal Augments The advantages include ready availability and quick application Brand MG, et al. Tibial tray augmentation with modular metal wedges for tibial bone stock deficiency. Clin Orthop 1989;248:71–9.

Indications for Metal Augments Inability to achieve stability of the trial implants at the time of trial reduction. Inability to achieve stability of the trial implants at the time of trial reduction. 40% or more of the bone-implant interface is unsupported by host bone. 40% or more of the bone-implant interface is unsupported by host bone. Bone loss in total knee arthroplasty Graft augment and options1 John M. Cuckler MD J Arthroplasty Jun;19(4 Suppl 1):56-8.

Sleeves

29/1/09 Done 2004 Coag –ve Staph

5/3/10 stage revision

14/8/06 5/2/07 15/01/08

1/4/09 20/5/10

Hinges

21/4/11 3/5/11

12/5/11

Custom Made Prosthesis