Complications associated with the use of the recombinant human bone morphogenetic proteins for posterior interbody fusions of the lumbar spine.

STUDY DESIGN: Systematic review. OBJECTIVE: The objectives of this review are to examine the spectrum of complications that have been reported in the literature after posterior interbody fusions of the lumbar spine augmented with bone morphogenetic proteins (BMPs) and discuss potential methods for their prevention. SUMMARY OF BACKGROUND DATA: The use of BMPs for spinal arthrodesis procedures has increased dramatically during the past decade. These products are commonly used in "off-label" fashion in posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) constructs. Recently, a number of adverse events have been attributed to the use of BMP for PLIF and TLIF surgical procedure, including heterotopic ossification within the epidural space or neuroforamina, postoperative radiculitis, and endplate osteolysis with interbody device subsidence. METHODS: A computer aided literature search was performed on the electronic databases PubMed, MEDLINE, EMBASE, CINAHL, and Cochrane Database of Systematic Reviews. Key words of interest included BMPs, PLIF, TLIF, complications, heterotopic ossification, radiculitis, and osteolysis. All articles, in the English language, between 1990 and 2011 were considered relating to the use of BMPs in PLIF and TLIF constructs. RESULTS: Seventeen articles discussing the use and potential complications of BMPs in PLIF and TLIF constructs were identified and reviewed. The studies were in the range of a level I prospective randomized trial to case reports of complications. There is a wide variation of published complications associated with BMP-augmented PLIF and TLIF constructs. CONCLUSION: Despite high fusion rates there is a growing body of evidence that the use of BMP in PLIF and TLIF constructs does not come without potential complication. There are appreciable rates of BMP-specific complications, which include heterotopic ossification within the epidural space or neuroforamina, postoperative radiculitis, and endplate osteolysis with interbody device subsidence.

ProDisc-L learning curve: 24-Month clinical and radiographic outcomes in 44 consecutive cases.

BACKGROUND: Total disc replacement (TDR) promises preservation of spine biomechanics in the treatment of degenerative disc disease but requires more careful device placement than tradition fusion and potentially has a more challenging learning curve. METHODS: A cohort of 44 consecutive patients had 1-level lumbar disc replacement surgery at a single institution by a single surgeon. Patients were followed up clinically and radiographically for 24 months. Patients were divided into 2 groups of 22 sequential cases each. Clinically, preoperative and postoperative Oswestry Disability Index, visual analog scale, Short Form 12 (SF-12) Mental and Physical Components, and postoperative satisfaction were measured. Radiographically, preoperative and postoperative range of motion (ROM) dimensions, prosthesis deviation from the midline, and disc height were measured. TDR-related complications were noted. Logarithmic curve-fit regression analysis was used to assess the learning curve. RESULTS: Operative time decreased as cases progressed, with an asymptote after 22 cases. The operative time for the later group was significantly lower (P < .0005), but hospital stay was significantly longer (P = .03). There was no significant difference in amount of blood loss (P = .10) or prosthesis midline deviation (P = .86). Clinically, there was no significant difference in postoperative scores between groups in Oswestry Disability Index (P = .63), visual analog scale (P = .45), SF-12 Mental Component (P = .66), SF-12 Physical Component (P = .75), or postoperative satisfaction (P = .92) at 24 months. Radiographically, there was no significant difference in improvement between groups in ROM (P = .67) or disc height (P = .87 for anterior and P = .13 for posterior) at 24 months. For both groups, there was significant improvement for all clinical outcomes and disc height over preoperative values. One patient in the later group had device failure with subluxation of the polyethylene, which required revision. CONCLUSIONS/LEVEL OF EVIDENCE: Early experience can quickly reduce operative time but does not affect clinical outcomes or ROM significantly (level IV case series). CLINICAL RELEVANCE: Lumbar TDR is a rapidly learnable technique in treatment of degenerative disc disease.