Initial results of anterior interbody fusion achieved with a less invasive bone harvesting technique

Selective Anterior Lumbar Interbody Fusion for Low Back Pain Associated With Degenerative Disc Disease Versus Nonsurgical Management

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

To evaluate the long-term outcomes of selective one- to two-level anterior lumbar interbody fusions (ALIFs) in the lower lumbar spine versus continued nonsurgical management.

SUMMARY OF BACKGROUND DATA

Low back pain associated with lumbar intervertebral disc degeneration is common with substantial economic impact, yet treatment remains controversial. Surgical fusion has previously provided mixed results with limited durable improvement of pain and function.

METHODS

Seventy-five patients with one or two levels of symptomatic Pfirrmann grades 3 to 5 disc degeneration from L3-S1 were identified. All patients had failed at least 6 months of nonsurgical treatment. Forty-two patients underwent one- or two-level ALIFs; 33 continued multimodal nonsurgical care. Patients were evaluated radiographically and the visual analog pain scale (VAS), Oswestry Disability Index (ODI), EuroQol five dimensions (EQ-5D), and Patient-Reported Outcomes Measurement Information System scores for pain interference, pain intensity, and anxiety. As-treated analysis was performed to evaluate outcomes at a mean follow-up of 7.4 years (range: 2.5-12).

RESULTS

There were no differences in pretreatment demographics or nonsurgical therapy utilization between study arms. At final follow-up, the surgical arm demonstrated lower VAS, ODI, EQ-5D, and Patient-Reported Outcomes Measurement Information System pain intensity scores versus the nonsurgical arm. VAS and ODI scores improved 52.3% and 51.1% in the surgical arm, respectively, versus 15.8% and -0.8% in the nonsurgical arm. Single-level fusions demonstrated improved outcomes versus two-level fusions. The pseudarthrosis rate was 6.5%, with one patient undergoing reoperation. Asymptomatic adjacent segment degeneration was identified in 11.9% of patients.

CONCLUSION

Selective ALIF limited to one or two levels in the lower lumbar spine provided improved pain and function when compared with continued nonsurgical care. ALIF may be a safe and effective treatment for low back pain associated with disc degeneration in select patients who fail nonsurgical management.

LEVEL OF EVIDENCE

3.

Bone graft substitutes for anterior lumbar interbody fusion

The procedure of anterior lumbar interbody fusion (ALIF) is commonly performed on patients suffering from pain and/or neurological symptoms associated with disorders of the lumbar spine caused by disc degeneration and trauma. Surgery is indicated when prolonged conservative management proves ineffective. Because an important objective of the ALIF procedure is solid arthrodesis of the degenerative spinal segment, bone graft selection is critical. Iliac crest bone grafts (ICBG) remain the "gold standard" for achieving lumbar fusion. However, patient dissatisfaction stemming from donor site morbidity, lengthier operating times and finite supply of ICBG has prompted a search for better alternatives. Here presented is a literature review evaluating available bone graft options assessed within the clinical setting. These options include autografts, allograft-based, synthetic and cell-based technologies. The emphasis is on the contentious use of recombinant human bone morphogenetic proteins, which is in widespread use and has demonstrated both significant osteogenic potential and risk of complications.

Injury of the right and left inferior epigastric artery during the implantation of a stand-alone ALIF cage through a left retroperitoneal approach: a case report

Various perioperative vascular complications of anterior lumbar spine procedures have been described in orthopaedic literature. We report the unusual case of a perioperative bleeding from the right and left epigastric inferior artery occurring when using a stand-alone ALIF device (Synfix, Synthes, Oberdorf, Switzerland) at the L5/S1 level through an anterior left retroperitoneal approach. The primary stability of the Synfix is achieved by four divergent screws which are inserted through the anteriorly located plate into the neighbouring vertebral endplates. For the screw insertion the surrounding structures have to be mobilized more extensively than during a “standard” anterior lumbar interbody fusion (ALIF) procedure. The epigastric inferior arteries were embolized by applying polyvinyl alcohol particles and metal coils. The retroperitoneal haematoma caused herniation of the external rectus sheath. Hence revision surgery with removal of the haematoma and resuturing of the rectus sheath were performed. Insertion of divergent screws of the Synfix device may cause severe distension and rupture of the epigastric vessels. This case shows that a lesion of the right epigastric artery may be a hazard even in left retroperitoneal approaches. To the author’s knowledge this is the first case describing a lesion of the right epigastric artery during an ALIF procedure through a left retroperitoneal approach.

Effect of bone marrow cell collection techniques and donor site locations on in-vitro growth of bone forming cells

Purpose

This study evaluated the influence of bone marrow cell collection techniques and donor site locations on the in-vitro growth of bone-forming cells.

Methods

Sixty six samples of bone marrow cell collections (BMCC) or bone marrow aspirates (BMA) from 15 patients were obtained. Thirty eight samples for culture were composed of 23 BMA from 7 tibial condyles and 16 ilia, with the other 15 BMCC from the contralateral ilia. The other 28 samples were used for the analysis of alkaline phosphatase activities. After counting total cell number, mesenchymal stem cells (MSC) obtained from samples were incubated for 14 days. Alkaline phosphatase staining was used to count the number of stained colonies to show osteogenic differentiation.

Results

The average MSC counts of BMA from tibial condyles and ilia were 1.42×10⁶ and 7.35×10⁶ respectively, with 4.80×10⁶ from ilial BMCC (p=0.010). MSC cultures could not be produced from tibial condyles in all 7 samples. However, 9 of 15 BMCC samples and 9 of 16 ilial BMA samples were successfully cultured (p=0.018). The average of cell counts in the successful cultures was 7.92×10⁶, whereas that in the failed cultures was 2.85×10⁶ (p=0.000). Multiple regression analysis showed that colony count was associated with the patient's age and total cell numbers, but not with collection methods such as BMCC or BMA (p=0.000, R=0.648, beta; age=-0.405, cell number=0.356). The discriminating formula indicated that more than 5.25×10⁶ cells were needed for successful culture.

Conclusions

For successful cultures in vitro and for grafts, the total number of collected bone forming cells is more important than donor sites or collection methods. For young patients, grafting of bone-marrow-derived osteoprogenitor cells is promising.