Core decompression with bone marrow injection : Preliminary results of a prospective randomized study assessing the effect of Rh-BMP7 MIGAUD MIGAUD H, BOCQUET D, PINOIT Y, MAY O, COTTEN A, HERENT S, LAFFARGUE P Services dOrthopédie C et de Radiologie Ostéo- Articulaire, CHRU de Lille

Introduction (1) Disappointing results after core decompressionDisappointing results after core decompression Frequent failuresFrequent failures –Evolutive femoral head deformity –Sub-trochanteric fractures Long delay before weight bearingLong delay before weight bearing Unpredictable results even at early stages of AVNUnpredictable results even at early stages of AVN

Introduction (2) Core decompression improvementCore decompression improvement –Percutaneous surgery –Autologus bone marrow injection (but variable activity according to AVN etiology) –Rh-BMP7 injection PurposePurpose –To asses this new method –To asses efficacy and tolerance of BMP7 injection with bone marrow

Patients and Methods (1) Prospective randomizedProspective randomized Two armsTwo arms 1) Decomp. + bone marrow 2) Decomp. + bone marrow + Rh-BMP7 Randomization according to Rh-BMP7 (OP1) availabilityRandomization according to Rh-BMP7 (OP1) availability Stages I to IIIA Ficat enrolled (Head deformity < 3mm)Stages I to IIIA Ficat enrolled (Head deformity < 3mm) Main criteria of results = rate of conversion to THRMain criteria of results = rate of conversion to THR +/- BMP7

Patients and Methods (2) One surgeonOne surgeon 24 hips included24 hips included Mean Follow-up = 12 months (6 to 30)Mean Follow-up = 12 months (6 to 30) 12 hips in group BMP- and 12 in group BMP+12 hips in group BMP- and 12 in group BMP+ Etiology of AVN

Results (1) No infectionNo infection All treated as outpatient except for 2 patients who had controlateral THR at the same timeAll treated as outpatient except for 2 patients who had controlateral THR at the same time Immediate full weight bearingImmediate full weight bearing No sub-trochanteric fractureNo sub-trochanteric fracture 4 heterotopic ossifications in vastus lateralis (all in BMP+ arm) Spontaneous favorable healing4 heterotopic ossifications in vastus lateralis (all in BMP+ arm) Spontaneous favorable healing

Results (2) Seven failures (THR conversion)Seven failures (THR conversion) 4 in BMP+ and 3 in BMP- arms4 in BMP+ and 3 in BMP- arms 3 already converted3 already converted – All in BMP+ arm –All were stages III before core decompression, one bilateral and one controlateral to THR 4 were impending failures4 were impending failures –1 Stage III (BMP+ arm) –2 Stages II (2 in BMP- arms) –1 Stage I (in BMP- arm) revised by a new core decompression + bone marrow + Rh-BMP7 3b3a 3b3a 3a -> 3b

Results (3) Seven clinical failuresSeven clinical failures No significant difference according to :No significant difference according to : –AVN Ficat stages –Rh-BMP7 use –Etiology of AVN (steroids) J0 30 Months J0 12 Months

Conclusions (1) Simple technique, allowing outpatient procedure and early recovery of full weight bearingSimple technique, allowing outpatient procedure and early recovery of full weight bearing No adverse effect of using BMP7, but no advantage in terms of preventing THR conversionNo adverse effect of using BMP7, but no advantage in terms of preventing THR conversion But there was no assessment of bone marrow activity (confounding factor)But there was no assessment of bone marrow activity (confounding factor) Incorrect randomization related to OP1 availability (cost)Incorrect randomization related to OP1 availability (cost)

Conclusions (2) BMP+ group had a higher rate of Stage III (but NS). BMP prevented from a higher rate of failure ?BMP+ group had a higher rate of Stage III (but NS). BMP prevented from a higher rate of failure ? MRI bone healing only in BMP+ armMRI bone healing only in BMP+ arm The procedure does not worsen a subsequent THRThe procedure does not worsen a subsequent THR –no skin, muscular, bone scars –no ossification after THR conversion in BMP+ arm 24 M J0

The future (3) Starting a double blind randomized study comparing Core decompression versus Core decompression + bone marrow + BMP7Starting a double blind randomized study comparing Core decompression versus Core decompression + bone marrow + BMP7 Assessment of bone marrow activity (CFU-F, ….)Assessment of bone marrow activity (CFU-F, ….) Results according to AVN volume on MRIResults according to AVN volume on MRI 80 hips followed 5 years (40 BMP+ / 40 BMP-)80 hips followed 5 years (40 BMP+ / 40 BMP-)

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NS

P = 0,02

Results (3) Seven clinical failuresSeven clinical failures No significant difference according to :No significant difference according to : –AVN Ficat stages –Rh-BMP7 use –Etiology of AVN (steroids) J0 30 Months J0 12 Months