“a controlled randomized outcome study of femoral ring allograft versus bak instrumentation in...
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“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in
Anterior Interbody Fusion”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in
Anterior Interbody Fusion”
Dr. Donald W. Kucharzyk Dr. Michael Trainor
Crown Point, Indiana, USA
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
Originally described for Pott’s diseaseCloward was the first to show its use in
the treatment of low back painLumbar interbody arthrodesis has
become the treatment of choice for disabling low back pain
Graft placement is favorable for fusion being placed in compression and having a good vascular disc space
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
Anterior lumbar interbody fusion’s have been performed for many years
The goals have been to re-establish disc space height,the correction of malalignment, re-establish normal neuroforaminae, and achieve a solid arthrodesis
Autograft as well as allograft have been used in the past to achieve these goals
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
Graft material available include both allograft and autograft
Forms of allograft graft material include: rings, wedges, and cortical dowels
Autograft exists in the form of iliac crest wedges
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
Autograft was the gold standard for interbody fusion with favorable outcome studies
Allograft in the form of wedges, rings or dowels have also performed well with decreased complications
“Kanayama et al”: reported the superiority of allograft versus autograft in terms of strength and stability
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
Recent advancements in spine fusion technology has lead to the development of titanium cages
These new devices have shown biomechanical stability via reduced spinal segmental motion with arthrodesis
“Tsantrizos et al”: revealed in a study of ALIF constructs that cages reduced spinal motion similar to auto or allografts
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
A review of the published orthopaedic literature has revealed no study directly comparing allograft versus metallic interbody cages
A study was undertaken to randomly assess the results comparing anterior interbody fusion via femoral ring allograft versus a metallic interbody cage
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
Twenty patients with the diagnosis of one level spondylotic herniated nucleus pulposis with instability and radiculopathy were randomized
Two study groups were developed in which one received a femoral ring allograft (GROUP 1) and the other a BAK titanium metal cage (GROUP 2) with both receiving autogenous iliac crest graft
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
Patients were evaluated for average age, gender, average follow-up, risk factors, preoperative instability, operative time, blood loss, radiographic fusion, reconstruction of the disc height, migration of the graft, segmental lordosis, and revision rates
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
INDICATIONS Internal Disc DisruptionPost-Laminectomy SyndromeDiscogenic InstabilityHNP with Instability (similar to the study pool indications
of Kuslich et al and Ray et al)
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
FUSION CRITERIA Severe, disabling, intratable back pain Symptoms for at least a year Failure of conservative treatment No previous arthrodesis at target level Absence of degeneration at next level Loss of disc height and instability (similar to criteria of Ray et al)
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTSAverage age : 52.3 yrs (range 32 to 58)Gender: males: 8 females: 12Average Follow-up: 4 yrs (3yrs to 5yrs)Operative Time: GROUP 1: 63 minutes GROUP 2: 73 minutes range of time: 45-85 minutes
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTSAverage Blood Loss: 50cc (range 25-
100)Risk factors: 10 patients were smokersPreoperative Pain Levels: Disabling: 8 Marked: 8 Moderate: 4
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTSPreoperative Instability: assessed on lateral flexion/extension radiograph to compare motion of the individual segment Average Motion: 12 degrees range was from 10 to 24 degrees
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS PREOPERATIVE AND POSTOPERATIVE SEGMENTAL LORDOSIS (measured on a standing lateral) GROUP 1 GROUP 2 Preop: 3 deg. Preop: 5 deg. Postop: 16 deg. Postop: 11 deg.
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS RESTORATION OF DISC HEIGHT (measured preop, postop, and at follow-up) GROUP 1 GROUP 2 Preop: 2mm 5mm Postop: 8mm 9mm FU (2yrs) 7mm 6mm lost hgt. 4/11 4/9 maintained 7/11 5/9
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS DEPTH OF GRAFT PLACEMENT (measured posterior vertebral body to
graft)
GROUP 1 GROUP 2 6.2mm 7.7mm
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS GRAFT MIGRATION(measured posterior vertebral body to
graft)
GROUP 1 GROUP 2 1mm in 4 of 11 2mm in 4 of 9
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS SUBSIDENCE OF GRAFT (comparision preop and postop
placement)
GROUP 1 GROUP 2 1mm in 3 of 11 3mm in 4 of 9
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS POSTOPERATIVE MOTION (flexion/extension lateral radiograph) GROUP 1 GROUP 2no change 7 of 11 no change in 5 of
94 deg. In 4 of 11 8 deg. In 4 of 9
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTSRadiographic Fusion Criteria -range of motion on flexion/extension lateral of less than 2 degrees -postoperative migration of 1mm or
less -no radiolucent lines
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTSMcAfee et al IMAST 2001 reported
in the original BAK study of motion 7 degrees or less, migration of 2mm or less, and a 2mm lucent line as acceptable for fusion
Later the criteria was changed to 3 degrees, still 2mm migration and 2mm lucent line
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
Criteria for fusion was reviewed recently by McAfee et al “Critical Discrepancy: A Criteria for Successful Arthodesis following Interbody fusion”
Discrepancies exist in criteria for fusionBAK Study: 5 degree’sRay et al (1997): 7 degree’sBAK article Spine 1998: 3 degree’s
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
Zdeblick et al: “ A Prospective Randomized Study of Lumbar Fusion” Spine 1993 established the criteria that should be applied to all fusions whether anterior, posterior, or 360 degree approach
Criteria was: 2 degree’s of motion on F/E
This was the criteria we adapted in our review of the data for this study
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTSFusion criteria was much more
stringent in our study poolFusion failure was therefore
defined as motion on F/E lateral radiograph, lucent line, collapse and subsidence, migration of the graft, and severe pain with functional limitations
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS RADIOGRAPHIC FUSION RESULTS
GROUP 1 GROUP 2Our Criteria 73% 56%BAK Study 93% 86%
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL RESULTS REVISION RATES
GROUP 1 GROUP 2 3 of 11 4 of 9 27% 44%
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL CASE
FEMORAL RING ALLOGRAFT
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL CASE
BAK CAGE
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL CASE
FEMORAL RING FAILURE
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CLINICAL CASE
BAK FAILURE
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CONCLUSIONFemoral ring allograft group re-
established disc heights better than the BAK group
Segmental lordosis was better re-established in the femoral ring allograft group than the BAK group
Subsidence was less in the femoral ring allograft group than the BAK group
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CONCLUSIONMotion was seen in both groups but
was greater in the BAK groupGraft migration was seen in both
groups but was greater in the BAK group
Revision rates were higher in the BAK group than the femoral ring allograft group
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
CONCLUSIONSDifference in fusion rates Femoral
Ring versus BAK stems from the fact that the Femoral Ring pool was a complete discectomy versus the BAK which was partial reamed channel discectomy
Similar to a study by McAfee et al IMAST 2001
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
““A Controlled Randomized Outcome Study of A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Femoral Ring Allograft versus BAK Instrumentation in Anterior Lumbar Fusions”Instrumentation in Anterior Lumbar Fusions”
CONCLUSIONSComplete discectomy offer higher fusions
rates than partial reamed channel discectomy due to more surface area, less avascular disc material remaining, better orientation, and restoration of disc height
Complete discectomy should be performed when utilizing any interbody device
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
“A Controlled Randomized Outcome Study of Femoral Ring Allograft versus BAK Instrumentation in Anterior Interbody Fusions”
CONCLUSIONFinally, based upon the results of
this study, the traditional more cost effective femoral ring allograft technique of interbody lumbar fusion performed comparably well next to the newer BAK technology
THANK YOUTHANK YOU THANK YOUTHANK YOU
Dr. Donald W. KucharzykDr. Donald W. Kucharzyk
The Orthopeadic, Pediatric & The Orthopeadic, Pediatric & Spine InstituteSpine Institute