RECOVERY. P r o t r u s i o

Transcription

1 RECOVERY P r o t r u s i o TM C a g e

2 RECOVERY P r o t r u s i o TM C a g e Design Features Revision acetabular surgery is a major challenge facing today s total joint revision surgeon. Failed endo/bi-polars, cemented cups, and modular porous coated cups contribute to acetabular bone remodeling and osteolytic cysts. This bone loss is a major concern with regard to achieving stability with the new prosthesis. Revision acetabular surgery requires the skilled surgeon to reconstruct the acetabulum utilizing morselized and/or a bulk allograft. The reconstructed acetabulum must accept an implant that can work with nature to gain and maintain stability. The Recovery Protrusio Cage is a load sharing device used in revision cases for protrusio or large defect situations in the acetabulum. It is not an acetabular component but is designed to protect compromised acetabular bone, either very thin column or bone allograft. Routinely, it is used to provide additional support for morselized and/or a bulk allograft. The Recovery Protrusio Cage is to be cemented into place and augmented with 6.5mm acetabular screws. Host bone, allograft or cement should always be used to fully support the Recovery Protrusio Cage. An all-poly cup is then cemented into the Recovery Protrusio Cage. The Recovery surgical technique was developed in conjunction with Roger H. Emerson, Jr., M.D. Biomet, as the manufacturer of this device, does not practice medicine and does not recommend any particular surgical technique for use on a specific patient. The surgeon who performs any implant procedure is responsible for determining and utilizing the appropriate techniques for implanting the prosthesis in each individual patient. Biomet is not responsible for selection of the appropriate surgical technique to be utilized for an individual patient. For cemented use only in the United States. Large ilium flange allows screw fixation to uncompromised host bone on the ilium. Manufactured from commercially pure titanium which is malleable, allowing the surgeon to intraoperatively customize the device to fit the contours of the host and allograft bone. The anterior cutout allows retroverted positioning of the cage to achieve intimate contact with bone. Neck impingement and dislocation is minimized with anatomic positioning of the cemented all-poly cup. Inferior windows allow for impaction of morselized bone graft through the device and allow for continuous bone graft/cement re-bar type construct. Obturator foramen hook provides easily accessible fixation to host bone and aids in maintaining the normal center of rotation. Grit-blasted finish promotes cement interdigitation. This device is intended to be utilized in conjunction with the Bio-Clad all-poly cup. All screw holes accept the 6.5mm acetabular screws. Sizes are available from 52mm to 73mm in 3mm increments in rights and lefts.

3 Surgical Technique Surgical Approach Excellent ilium exposure is needed when utilizing a protrusio cage. An anterior iliac wing stripping approach, transtrochanteric approach, or a posterior approach affords exceptional exposure for these cases. Component Removal The loose acetabular component can be removed with curved osteotomes. Membrane and granulomatous tissue from the prior arthroplasty should be removed with a curette. Acetabular Preparation The acetabulum should be prepared with acetabular reamers, maintaining as inferior medial and anterior location as possible. Extreme care should be taken when severe compromised bone stock is present. 5 Once the new acetabulum is created, the proper size of the Recovery Protrusio Cage can be determined. A properly sized metal framed shell gauge should fit tightly between the anterior and posterior columns. The Recovery Protrusio Cage is a line-to-line fit. If reaming stops at size 58mm, a size 58mm Recovery Protrusio Cage is selected. Sizing & Component Selection 6 Once the correct size is determined, the Recovery Protrusio Cage is introduced into the acetabulum. The inferior hook is placed first, followed by the ilium flange. Intimate contact of the ilium flange with the host bone of the ilium is desired. Initially, if intimate contact is not achieved, the Recovery Protrusio Cage is extracted from the wound, further contoured and reintroduced into the acetabulum. Once intimate contact is achieved, the cage is impacted with the Delrin impactor ball. Note: If the device is bent more than once in the same location, the device may experience premature failure. Cage Insertion 7 Dome screws should be placed first in the best bone available, maintaining a vertical position of the screws. The ilium flange should then be fixed with at least two screws into the ilium. Once screw placement is completed, the obturator foramen hook is crimped into place. Cage Fixation

4 Case Histories Case Histor Historyy 1 This patient is now 59 years of age. She had her first replacement at age 35, a right cemented total hip replacement in She had a second replacement converting to a bi-polar acetabular in Subsequently, the bi-polar acetabular showed migration, shortening of the leg and pain. Her original femoral stem is in place. Reconstruction of the acetabulum took place with a superior roof allograft and the Recovery Protrusio Cage to restore her leg length and center of rotation. The screws in the graft were in the weight bearing line and additional dome screws were placed through the Recovery Protrusio Cage and ilium. The postoperative X-ray is at the 11/2 year mark. Case 1 Preoperative X-ray Case 1 Postoperative X-ray Case 2 Preoperative X-ray Case 2 Postoperative X-ray Case Histor Historyy 2 At age 16, this patient was diagnosed with avascular necrosis. She was treated with a cup arthroplasty. This was revised to a second cup arthroplasty, followed by a cemented hip replacement, followed by a revision of cemented hip replacement to a bi-polar acetabular replacement. Her bi-polar acetabular, as is shown in the preoperative X-ray, has migrated superiorly. She had a prior roof graft that resorbed. Marked leg length discrepancy was present. She was reconstructed with a structural graft in the weight bearing area with superior screws in the weight bearing line. The screws are designed to secure the graft, as well as to protect the graft from the Recovery Protrusio Cage. The X-ray shows how the Recovery Protrusio Cage conforms to the supporting screws. In addition to screws in the graft, there are two screws in the dome of the cage and two screws on the wing of the ilium. The center of rotation has been restored, as well as the patient s leg lengths. The X-rays shown are at six month post-op, and the patient is currently progressing to a cane.

5 Ordering Information Recovery Protrusio Cage Part No. Size mm LT mm LT mm LT mm LT mm LT mm LT mm LT mm LT mm RT mm RT mm RT mm RT mm RT mm RT mm RT mm RT Bio-Clad Hi-Wall w/peg Part No. Size mm x 39 RM mm x 42 RM mm x 45 RM mm x 48 RM mm x 48 RM mm x 51 RM mm x 54 RM mm x 57 RM mm x 60 RM mm x 63 RM mm x 66 RM mm x 69 RM mm x 51 RM mm x 54 RM mm x 57 RM mm x 60 RM mm x 63 RM mm x 66 RM mm x 69 RM Bio-Clad 10 Degree w/peg Part No. Size mm x 39 RM mm x 42 RM mm x 45 RM mm x 48 RM mm x 48 RM mm x 51 RM mm x 54 RM mm x 57 RM mm x 60 RM mm x 63 RM mm x 66 RM mm x 69 RM mm x 51 RM mm x 54 RM mm x 57 RM mm x 60 RM mm x 63 RM mm x 66 RM mm x 69 RM Recovery Templates Bio-Clad All-Poly Cup X-Ray Template Set Recovery, Bio-Clad and Delrin are trademarks of Biomet, Inc. P.O. Box 587, Warsaw, IN Biomet, Inc. All Rights Reserved web site: biomet@biomet.com Form No. Y-BMT-636/123199/H

6 4 Grafting Defects Morselized cortical cancellous graft is placed in the cavitary defects and reverse reaming is performed to impact the graft. If larger structural defects are present, a bulk allograft can be contoured to fit the defect and held with superior screws into the ilium. The posterior column is critical for structural support and may require plating of the posterior column. Note: The Recovery Protrusio Cage must always be fully supported on host bone, allograft, or cement. Use in the presence of pelvic discontinuity will cause insufficient support for the device and lead to premature failure. 8 All-Poly Cup Insertion Once the Recovery Protrusio Cage is implanted, additional morselized graft may be impacted through the windows in the inferior portion of the device. Cement is then packed into the dry Recovery Protrusio Cage and pressurized with an obturating instrument that is slightly larger than the opening of the shell. A Bio-Clad all-poly cup is cemented into the device with approximately 10 to 15 degrees of forward flexion and 35 to 50 degrees of abduction. Extra cement should be cleared and the polyethylene component held in the desired position until the cement has set up. If a size 58mm Recovery Protrusio Cage is implanted, then a 54mm Bio-Clad all-poly cup is utilized. The pegs of the cup will provide a 3mm cement mantle (6mm circumferentially). Cage Size 52mm 55mm 58mm 61mm 64mm 67mm 70mm 73mm Cup Size 48mm 51mm 54mm 57mm 60mm 63mm 66mm 69mm 9 Trial Reduction When the hip is reduced, the stability should be checked, watching especially for impingement of the anterior neck of the femoral component on the anterior portion of the reinforcement shell.