A retrospective study of iliac crest bone grafting techniques with allograft reconstruction: do patients even know which iliac crest was harvested? Clinical article

Reconstruction After En Bloc Resection of a Distal Radius Tumor. An Updated and Concise Review

The distal radius is rarely affected by either primary or metastatic bone cancers. The most frequent tumors of the distal radius are giant cell tumors, which are benign tumors with the propensity to invade. En bloc excision of giant cell tumors of the distal radius achieves a low recurrence rate but compromises the wrist joint, necessitates a significant reconstruction, and has functional consequences. Reconstruction after en bloc resection of a distal radius bone tumor is challenging. Furthermore, orthopedic oncologists disagree on treating such long bone anomalies most effectively. The present article summarizes the various biological and non-biological reconstruction techniques performed after en bloc resection of a distal radius tumor, discusses the advantages and disadvantages of each reconstruction strategy, and summarizes several case studies and case reports.

Scaphoid Bone Nonunions: Clinical and Functional Outcomes of Collagen/PGA Scaffolds and Cell-Based Therapy

In this study, the procedure for treating the nonunion complication of scaphoid fractures using collagen/poly glycolic acid (CPGA) scaffolds with bone marrow mesenchymal stem cell (BM-MSC) therapy was adopted and compared with the commonly employed autologous bone tissue graft. With conducting a two-armed clinical trial, 10 patients with scaphoid nonunions were enrolled in this investigation. Patients were randomly assigned to two groups treated with (1) CPGA + cell therapy and (2) autologous iliac crest bone graft standard therapy. Treatment outcomes were evaluated three months after surgery, measuring the grip and pinch strengths and wrist range of motion, with two questionnaires: Patient-Rated Wrist Evaluation (PRWE) and Quick form of Disabilities of the Arm, Shoulder, and Hand (QDASH). We have also assessed the union rate using clinical and radiologic healing criteria one and three months post-operatively. Restorative effects of CPGA + cell therapy were similar to those of the autologous bone graft standard therapy, except for the grip strength (P = 0.048) and QDASH score (P = 0.044) changes, which were higher in the CPGA + cell therapy group. Three months following the surgery, radiographic images and computed tomography (CT) scans also demonstrated that the scaphoid union rate in the test group was comparable to that of scaphoids treated with the standard autograft method. Our findings demonstrate that the CPGA + cell therapy is a potential alternative for bone grafting in the treatment of bone nonunions.

Evaluation of Topology Optimization Using 3D Printing for Bioresorbable Fusion Cages: A Biomechanical Study in a Porcine Model

STUDY DESIGN

Preclinical biomechanical study of topology optimization versus standard ring design for bioresorbable poly-ε-caprolactone (PCL) cervical spine fusion cages delivering bone morphogenetic protein-2 (BMP-2) using a porcine model.

OBJECTIVE

The aim was to evaluate range of motion (ROM) and bone fusion, as a function of topology optimization and BMP-2 delivery method.

SUMMARY OF BACKGROUND DATA

3D printing technology enables fabrication of topology-optimized cages using bioresorbable materials, offering several advantages including customization, and lower stiffness. Delivery of BMP-2 using topology optimization may enhance the quality of fusion.

METHODS

Twenty-two 6-month-old pigs underwent anterior cervical discectomy fusion at one level using 3D printed PCL cages. Experimental groups (N=6 each) included: Group 1: ring design with surface adsorbed BMP-2, Group 2: topology-optimized rectangular design with surface adsorbed BMP-2, and Group 3: ring design with BMP-2 delivery via collagen sponge. Additional specimens, two of each design, were implanted without BMP-2, as controls. Complete cervical segments were harvested six months postoperatively. Nanocomputed tomography was performed to assess complete bony bridging. Pure moment biomechanical testing was conducted in all three planes, separately. Continuous 3D motions were recorded and analyzed.

RESULTS

Three subjects suffered early surgical complications and were not evaluated. Overall, ROM for experimental specimens, regardless of design or BMP-2 delivery method, was comparable, with no clinically significant differences among groups. Among experimental specimens at the level of the fusion, ROM was <1.0° in flexion and extension, indicative of fusion, based on clinically applied criteria for fusion of <2 to 4°. Despite the measured biomechanical stability, using computed tomography evaluation, complete bony bridging was observed in 40% of the specimens in Group 1, 50% of Group 2, 100% of Group 3, and none of the control specimens.

CONCLUSION

A topology-optimized PCL cage with BMP-2 is capable of resulting in an intervertebral fusion, similar to a conventional ring-based design of the same bioresorbable material.

Structural Bicortical Autologous Iliac Crest Bone Graft Combined with the Tunnel Bone Tamping Method for the Depressed Tibial Plateau Fractures

BACKGROUND

Clinically, autologous iliac crest bone grafts (ICBG) and bone tamping methods are often applied to manage depressed tibial plateau fractures (DTPFs). The purpose of this study was to describe and evaluate the technique of using structural bicortical autologous ICBG combined with the tunnel bone tamping method (TBTM) for treating DTPFs.

METHODS

All patients with DTPFs who underwent structural bicortical autologous ICBG combined with TBTM from January 2016 to February 2018 were prospectively analysed. Demographics, injury, surgery, postoperative complications, and clinical outcomes were recorded. All patients were followed up for more than 30 months. Postoperative radiography and CT were employed to assess fracture healing and the reduction quality.

RESULTS

Forty-three of the included patients completed the follow-up. No malreduction was observed. Based on the immediate postoperative imaging, the intra-articular step-off was significantly reduced (8.19 mm preoperatively vs. 1.30 mm immediate postoperatively, P < 0.001). From the immediate operation to the latest follow-up, the reduction was maintained significantly well, with a nonnegligible absolute difference (0.18 mm, P = 0.108). A remarkable secondary loss of reduction (intra-articular step off > 3 mm) was found in two elderly patients (2/43, 4.65%). The incidence of complications related to the bone-graft donor and bone-graft site was 2.33% and 4.65%, respectively. At the final follow-up, the mean Hospital for Special Surgery (HSS) score of the knee was 98.19 ± 2.89, and the mean 36-Item Short-Form Health Survey (SF-36) score was 95.65 ± 4.59.

CONCLUSION

Structural bicortical autologous ICBG combined with TBTM is radiologically effective and stable in terms of complications for the DTPFs.

Novel cell sources for bone regeneration

A plethora of both acute and chronic conditions, including traumatic, degenerative, malignant, or congenital disorders, commonly induce bone disorders often associated with severe persisting pain and limited mobility. Over 1 million surgical procedures involving bone excision, bone grafting, and fracture repair are performed each year in the U.S. alone, resulting in immense levels of public health challenges and corresponding financial burdens. Unfortunately, the innate self-healing capacity of bone is often inadequate for larger defects over a critical size. Moreover, as direct transplantation of committed osteoblasts is hindered by deficient cell availability, limited cell spreading, and poor survivability, an urgent need for novel cell sources for bone regeneration is concurrent. Thanks to the development in stem cell biology and cell reprogramming technology, many multipotent and pluripotent cells that manifest promising osteogenic potential are considered the regenerative remedy for bone defects. Considering these cells' investigation is still in its relative infancy, each of them offers their own particular challenges that must be conquered before the large-scale clinical application.

Lumbar Erector Spinae Plane Block for Posterior-Superior Iliac Spine Bone Graft Site Pain in Patients Undergoing Occipitocervical and C1-C2 Fusion for Atlantoaxial Dislocation/Odontoid Fracture-A Case Series

Pain at the autologous bone graft site from the posterior–superior iliac spine (PSIS) is severe enough to affect the postoperative ambulation. It adds to the morbidity of the surgical procedure. Inadequate pain management at the graft site not only affects the postoperative recovery but also can lead to chronic pain. We report the use of ultrasound (US)-guided lumbar erector spinae plane block (ESPB), to deliver effective analgesia for this pain. Patients who underwent occipitocervical fusion (OCF) and C1–C2 fusion using PSIS for atlantoaxial dislocation (AAD)/odontoid fracture from January to March 2020 and who received US-guided lumbar ESPB were retrospectively studied. All the necessary data were collected from the inpatient hospital, anesthesia, and the acute pain service records. A total of six patients received lumbar ESPB, of which one received a single shot injection, and the rest five had a catheter placement for postoperative analgesia. The average volume of intraoperative and postoperative bolus was 27(range: 15–30) and 21 (range: 15–30) mL of 0.2% ropivacaine, respectively. All patients achieved a unilateral sensory blockade ranging from L1 to L3 dermatomes. None of our patients had a numerical rating scale of > 4 on movement at any time point during the first 48 hours except in one, in whom only a single shot bolus was given. No complications related to ESPB were noted. All were ambulated on the second postoperative day except one. The average length of hospital stay was 6 (range: 4–10) days. US-guided lumbar ESPB provides excellent analgesia for PSIS bone graft site pain and promotes early ambulation.

[Acute appendicitis after bone grafting from the right anterior iliac crest-difficult differential diagnosis]

To fill bony defects, an iliac crest bone graft is often used. Typical complications are hematoma, nerve injuries, infection or donor site related pain. This article reports the case of a young patient with acute appendicitis after bone grafting from the right iliac crest. Because of the preceding operation, the correct diagnosis was difficult and was only possible by a differentiated clinical examination followed by machine-aided diagnosis.

Iliac Bone Harvesting Techniques for Bone Reconstruction. Comparative Study Between Tricortical Bone Harvesting vs Trapdoor Technique

Objective

To investigate the effects of trapdoor-procedure-based bone harvesting and tricortical iliac bone harvesting on the iliac bone-graft donor site pain experienced by patients and their clinical effects.

Methods

A retrospective analysis was performed using the clinical data of 65 patients with tibial plateau fractures who received autologous iliac bone-supporting grafts in two hospitals between January 2014 and January 2019. The patients who received trapdoor-procedure-based bone harvesting (34 cases) were in the experimental group, and those who received tricortical iliac bone harvesting (31 cases) were in the control group. This study compared differences in iliac bone-graft donor site incision length, intraoperative blood loss, amount of bones harvested, operation time, and postoperative complications between the two bone-harvesting methods. Subsequently, it evaluated the pain experienced by the two patient groups in their iliac bone-graft donor sites and their clinical effects.

Results

One week after surgery, the differences between the iliac bone-graft donor site pain score (measured using SF-MPQ-2) of the experimental group and the control group were not statistically different. However, 3 weeks, 5 weeks, and 3 months after surgery, the iliac bone-graft donor site pain scores of the experimental group were significantly lower than those of the control group. The iliac bone-graft donor site incision length and operation time of the experimental group were not significantly different from those of the control group. However, the iliac bone-graft donor site intraoperative blood loss, amount of bones harvested and the incidence of complications of the experimental group were significantly lower than those of the control group.

Conclusion

Trapdoor-procedure-based bone harvesting has lower donor site pain, intraoperative blood loss, and postoperative complications. However, for bone grafting in regions with significant bone loss, tricortical iliac bone harvesting remains the optimal option.

Patient Perceptions of Iliac Crest Bone Grafting in Minimally Invasive Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The objective of this study was to determine patients' perception of iliac crest bone graft (ICBG) harvesting and donor site pain following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

SUMMARY OF BACKGROUND DATA

The incidence of donor site pain has been debated in the literature because of the varying techniques associated with its harvest.

METHODS

Patients undergoing primary, single-level MIS TLIF with ICBG were retrospectively identified. ICBG harvesting was performed using a percutaneous technique with a tubular retractor. A survey was administered to assess if patients could accurately describe which side of their iliac crest they believed was harvested, and if they were experiencing any pain perceived to be originating from the donor site. Patient characteristics were compared using χ analysis and independent t test.

RESULTS

In total, 82 patients were included. The majority of patients had the ICBG harvested from the left iliac crest (97.5%). Approximately half of the patients correctly identified the side of harvest (50.6%). 48.1% of patients reported they were not confident or had guessed on their response. Patients that reported pain from the ICBG were more likely to feel confident or somewhat confident in their harvest site identification (57.9% vs. 46.3%) but less likely to be correct (36.8% vs. 63.4%) than patients without pain. 22 patients (27.8%) correctly identified the side of harvest without guessing. Of these, 11 (13.9%) reported pain.

CONCLUSIONS

Approximately half of patients undergoing MIS TLIF with ICBG are able to correctly identify which side of their iliac crest was harvested. However, the majority of patients reporting pain were unable to correctly identify the side of harvest. This suggests that most patients are likely attributing other sources of pain to their ICBG. Therefore, rates of donor site pain may be over-reported in the current literature with contemporary harvesting techniques.

Impact of Iliac Crest Bone Grafting on Postoperative Outcomes and Complication Rates Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

The relationship between bone graft technique and postoperative outcomes for minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has not been well-defined. This study aims to determine the effect of iliac crest bone grafting (ICBG) on patient-reported outcomes (PROs) and complication rates following MIS TLIF.

METHODS

Primary, single-level MIS TLIF patients were consecutively analyzed. Patients that prospectively received a percutaneous technique of ICBG were compared to patients that retrospectively received bone morphogenetic protein-2 (BMP-2). Complication rates were assessed perioperatively and up to 1 year postoperatively. Changes in Oswestry Disability Index (ODI), visual analogue scale (VAS) back, and VAS leg pain were compared. Rates of minimum clinically important difference (MCID) achievement at final follow-up for ODI, VAS back, and VAS leg scores were compared.

RESULTS

One hundred forty-nine patients were included: 101 in the BMP-2 cohort and 48 in the ICBG cohort. The ICBG cohort demonstrated increases in intraoperative blood loss and shorter lengths of stay. ICBG patients also experienced longer operative times, though this did not reach statistical significance. No significant differences in complication or reoperation rates were identified. The ICBG cohort demonstrated greater improvements in VAS leg pain at 6-week and 12-week follow-up. No other significant differences in PROs or MCID achievement rates were identified.

CONCLUSION

Patients undergoing MIS TLIF with ICBG experienced clinically insignificant increases in intraoperative blood loss and did not experience increases in postoperative pain or disability. Complication and reoperation rates were similar between groups. These results suggest that ICBG is a safe option for MIS TLIF.

Harvest of Iliac Crest Autograft Not Associated With Localized Pain

Background

There exists a wide variety of bone grafts, substitutes, and extenders, which are utilized in spinal arthrodesis surgery. While iliac crest autograft is the traditional gold standard for use in spinal arthrodesis, there is considerable discrepancy in the literature regarding its associated complications. Primarily among these is the perception that the procedure is painful and has a high infection rate. The purpose of this study is to determine if patients experience more pain postoperatively on the iliac crest autograft donor side of the pelvis than the contralateral side.

Methods

This study was a retrospective chart analysis of prospectively collected data on 76 patients who underwent elective lumbar arthrodesis with iliac crest autograft performed by one surgeon. The patients filled out a pain diagram with a five-region visual analogue scale, including each iliac crest, at the preoperative and each postoperative visit. Patient-reported pain data at various time points was compared from donor and contralateral sides and analysis included trends over time. Additionally, complications were noted when they occurred. The surgical approach involved a midline skin incision in all patients with epifascial and subperiosteal dissection to the posterior superior iliac spine.

Results

There were no significant differences in reported pain between donor and nondonor side. There was no significant main effect of side of measurement (P = .75) and no significant side by time of measurement interaction effect (P = .95). There was a significant main effect of time of measurement for both sides (P < .001). There were no cases of donor site complications.

Conclusions

Iliac crest harvest and reconstruction utilizing this technique does not result in increased pain on the side of the harvest. This study supports a low morbidity rate for iliac crest autograft harvest as no complications were seen in this series.

Level of Evidence

3.

Patients Cannot Reliably Distinguish the Iliac Crest Bone Graft Donor Site From the Contralateral Side After Lumbar Spine Fusion: A Patient-blinded Randomized Controlled Trial

STUDY DESIGN

A multicenter, randomized, intrapatient controlled trial.

OBJECTIVE

This study investigated whether lumbar fusion patients blinded to the harvest site (A) can identify the iliac crest used for bone harvesting and (B) whether this iliac crest is more painful than the contralateral side.

SUMMARY OF BACKGROUND DATA

Spinal fusion with iliac crest autograft is a frequently performed surgical procedure. A widely reported disadvantage of the harvesting procedure is potential donor site morbidity. This has driven the development of many bone graft substitutes. However, more recently the incidence and severity of donor site pain is debated, especially in lumbar fusion surgery.

METHODS

Ninety-two nontraumatic adult patients underwent a posterolateral (thoraco)lumbar fusion. Iliac crest bone graft was harvested unilaterally through the primary midline incision. At 6 weeks, 3 months, 6 months, and 1 year follow-up, patients were asked to identify the donor site and to rate pain in their back, left iliac crest and right iliac crest on a Visual Analogue Scale (VAS).

RESULTS

Ninety patients, 44 males and 46 females with a mean age of 54 years, were analyzed. The left/right distribution of the iliac crest donor site was 50/50 and 89% of the patients underwent a lumbar fusion below L3. Only 24% patients identified the harvest site correctly. Moreover, the VAS pain scores for the donor site and contralateral iliac crest did not differ and were at each timepoint lower than the scores for back pain.

CONCLUSION

This study showed that, during the first year after lumbar fusion surgery via a single midline incision approach, patients could not reliably identify the iliac crest used for bone graft harvesting and this iliac crest was not more painful than the untouched contralateral iliac crest. Therefore, donor site pain should not be the main reason to use bone graft alternatives for lumbar spinal fusion.

LEVEL OF EVIDENCE

2.

Escherichia coli BMP-2 showed comparable osteoinductivity with Chinese hamster ovary derived BMP-2 with demineralized bone matrix as carrier

Escherichia coli bone morphogenetic protein-2 (ErhBMP-2) had a larger yield but less osteoinductivity than Chinese hamster ovary cell bone morphogenetic protein-2 (CrhBMP-2). Since the release profile of rhBMP-2 affects its osteoinductivity, an appropriate carrier could improve the effect of ErhBMP-2. Demineralized bone matrix (DBM) was one of the most widely used bone substitutes, but few studies evaluated the osteoinductivity of ErhBMP-2 while it was carried by DBM. Therefore, we compared the osteoinductivity of ErhBMP-2 with CrhBMP-2 with DBM as the carrier of each. In vitro results showed ErhBMP-2 had slightly less osteoinductivity than CrhBMP-2. However, with DBM as the carrier, ErhBMP-2 induced significantly more bone regeneration in rat calvaria defects. Therefore, ErhBMP-2 might have comparable osteoinductivity with CrhBMP-2 while carried by DBM.

Iliac Crest Bone Graft for Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Prospective Analysis of Inpatient Pain, Narcotics Consumption, and Costs

STUDY DESIGN

Retrospective Analysis OBJECTIVE.: The aim of this study was to determine whether an association between increased acute pain, postoperative time, and direct hospital costs exists between the use of iliac crest bone grafting (ICBG) and bone morphogenic protein (BMP)-2 following a primary, single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

SUMMARY OF BACKGROUND DATA

ICBG has been associated with enhanced fusion rates. Concerns have been raised in regards to increased operative time and postoperative pain. The advantages of ICBG compared to other spinal fusion adjuncts have been debated.

METHODS

Prospective, consecutive analysis of patients undergoing primary, single-level MIS TLIF with ICBG was compared to a historical cohort of consecutive patients that received BMP-2. Operative characteristics were compared between groups using χ analysis or independent t test for categorical and continuous variables, respectively. Postoperative inpatient pain was measured using the Visual Analog Scale, and inpatient narcotics consumption was quantified as oral morphine equivalents. Outcomes were compared between groups using multivariate regression controlling for preoperative characteristics.

RESULTS

A total of 98 patients were included in this analysis, 49 in each cohort. No significant differences were noted between cohorts with exception to sex (Females: ICBG, 53.06% vs. BMP-2, 32.65%, P = 0.041). There was a significant increase in operative time (14.53 minutes, P = 0.006) and estimated blood loss (16.64 mL, P = 0.014) in the ICBG cohort. Narcotics consumption was similar between groups on postoperative days 0 and 1. ICBG was associated with decreased total direct costs ($19,315 vs. $21,645, P < 0.001) as compared to BMP-2.

CONCLUSION

Patients undergoing MIS TLIF with ICBG experienced increases in operative time and estimated blood loss that were not clinically significant. Furthermore, iliac crest harvesting did not result in an increase in acute pain or narcotics consumption. Further follow-up is necessary to determine the associated arthrodesis rates and long-term outcomes between each cohort.

LEVEL OF EVIDENCE

3.

Reconstruction of iliac crest defect after autogenous harvest with bone cement and screws reduces donor site pain

Background

The iliac crest is the most common autogenous bone graft donor site, although associated with postoperative pain, functional disability, cosmesis, morphology and surgical satisfaction. We assessed each aspect above by comparing iliac crest reconstruction with bone cement and screws following harvest with no reconstruction.

Methods

We evaluated patients who underwent large iliac crest harvesting, including ten patients who underwent iliac crest defect reconstruction with bone cement and cancellous screws (R group) and ten randomly matched patients without reconstruction (NR group) were evaluated prospectively in the same period. Local pain, cosmesis and other complications were assessed postoperatively at 1 week, 6 weeks, 3 months and 6 months.

Results

Pain, cosmesis and satisfaction of patients significantly differed between the two groups. The R group exhibited less complications and lower pain visual analogue scores at postoperative 1 week (p < 0.001), 6 weeks (p < 0.001) and 3 months (p < 0.01) but not at 6 months, at which time patients reported almost no pain. One patient reported pain for more than 1 year in the NR group. The R group exhibited better cosmesis, morphology and satisfaction than the NR group. In the NR group, one patient suffered pain when sitting up and another when wearing a belt.

Conclusion

Postoperative pain can be reduced and cosmesis can be improved through reconstructing the iliac crest defects after autogenous harvesting with bone cement and cancellous screws. The technique is simple, safe and easy to implement.

Postoperative pain following posterior iliac crest bone graft harvesting in spine surgery: a prospective, randomized trial

BACKGROUND CONTEXT

Postoperative pain at the site of bone graft harvest for posterior spine fusion is reported to occur in 6%-39% of cases. However, the area around the posterior, superior iliac spine is a frequent site of referred pain for many structures. Therefore, many postoperative spine patients may have pain in the vicinity of the posterior iliac crest that may not in fact be caused by bone graft harvesting. The literature may then overestimate the true incidence of postoperative iliac crest pain.

PURPOSE

We performed a prospective study testing the hypothesis that patients will not report significantly higher visual analog scores over the graft harvest site when compared with the contralateral, non-harvested side.

STUDY DESIGN/SETTING

This is a prospective, randomized cohort study.

PATIENT SAMPLE

Patients aged 18-75 years undergoing elective spinal fusion of one to two levels between L4 and S1 for spinal stenosis and spondylolisthesis were randomized to left-sided or right-sided iliac crest bone graft (ICBG) donor sites and blinded to the side of harvest.

OUTCOME MEASURES

Primary outcome was a 10-point visual analog scale (VAS) for pain over the left and right posterior superior iliac spine.

METHODS

Bone graft was harvested via spinal access incisions without making a separate skin incision over the crest. Each patient's non-harvested side served as an internal control. Data points were recorded by patients on their study visit sheets preoperatively and at 6 weeks, 3 months, 6 months, and 1 year postoperatively.

RESULTS

Forty patients were enrolled in the study (23 females) with an average follow-up of 8.1 months (1.5-12 months). Mean age was 51.7 years (23-77 years). Left- and right-side ICBG harvesting was performed equally between the 40 patients. The average volume of graft harvested from the left was 35.3 mL (15-70 mL) and 36.1 mL (15-60 mL) from the right. There was no statistical difference between preoperative VAS score on the harvested side compared with the non-harvested side (p=.415). Postoperatively, there were consistently higher VAS scores on the operative side; however, these differences were not statistically significant at 6 weeks (p=.111), 3 months (p=.440), 6 months (p=.887), or 12 months (p=.240). Both groups did, however, show statistically significant improvements in VAS scores over time within the operative and nonoperative sides (p<.05). Graft volume had no effect on the VAS scores (p=.382).

CONCLUSIONS

The current literature does not adequately illuminate the incidence of postoperative pain at the site of harvest and the relative magnitude of this pain in comparison with the patient's residual low back pain. This is the first study to blind the patient to the laterality of bone graft harvesting. Our randomized investigation showed that although pain on the surgical side was slightly higher, it was neither clinically nor statistically different from the nonsurgical side. Our conclusion supports surgeons' use of autologous bone graft, which offers a cost-effective, efficacious spinal fusion supplement.

A novel noninstrumented surgical approach for foramen reconstruction for isthmic spondylolisthesis in patients with radiculopathy: preliminary clinical and radiographic outcomes

OBJECTIVE The health care costs for instrumented spine surgery have increased dramatically in the last few decades. The authors present a novel noninstrumented surgical approach for patients with isthmic spondylolisthesis, with clinical and radiographic results. METHODS Charts of patients who underwent this technique were reviewed. The procedure consisted of nerve root decompression by reconstruction of the intervertebral foramen. This was achieved by removal of the pedicle followed by noninstrumented posterolateral fusion in which autologous bone graft from the right iliac crest was used. Outcomes regarding radicular complaints, bony fusion, progression of the slip, and complications were evaluated using patient history and radiographs obtained at follow-up intervals of 3-18 months after surgery. RESULTS A total of 58 patients with a mean age of 47 years were treated with this method. Partial removal of the pedicle was performed in 93.1% of the cases, whereas in 6.9% of the cases the entire pedicle was removed. The mean duration of surgery was 216.5 ± 54.5 minutes (range 91-340 minutes). The mean (± SD) duration of hospitalization was 10.1 ± 2.9 days (range 5-18 days). After 3 months of follow-up, 86% of the patients reported no leg pain, and this dropped to 81% at last follow-up. Radiographic follow-up showed bony fusion in 87.7% of the patients. At 1 year, 5 patients showed progression of the slip, which in 1 patient prompted a second operation within 1 year. No major complications occurred. CONCLUSIONS Treatment of isthmic spondylolisthesis by reconstruction of the intervertebral neuroforamen and posterolateral fusion in situ is a safe procedure and has comparable results with the existing techniques. Cost-effectiveness research comparing this technique to conventional instrumented fusion techniques is necessary to evaluate the merits for both patients and society.

Autograft versus Allograft for Cervical Spinal Fusion: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To compare the effectiveness and safety between iliac crest bone graft (ICBG), non-ICBG autologous bone, and allograft in cervical spine fusion. To avoid problems at the donor site, various allograft materials have been used as a substitute for autograft. However, there are still questions as to the comparative effectiveness and safety of cadaver allograft compared with autologous ICBG.

METHODS

A systematic search of multiple major medical reference databases was conducted to identify studies evaluating spinal fusion in patients with cervical degenerative disk disease using ICBG compared with non-ICBG autograft or allograft or non-ICBG autograft compared with allograft in the cervical spine. Radiographic fusion, patient-reported outcomes, and functional outcomes were the primary outcomes of interest. Adverse events were evaluated for safety.

RESULTS

The search identified 13 comparative studies that met our inclusion criteria: 2 prospective cohort studies and 11 retrospective cohort studies. Twelve cohort studies compared allograft with ICBG autograft during anterior cervical fusion and demonstrated with a low evidence level of support that there are no differences in fusion percentages, pain scores, or functional results. There was insufficient evidence comparing patients receiving allograft with non-ICBG autograft for fusion, pain, revision, and functional and safety outcomes. No publications directly comparing non-ICBG autograft with ICBG were found.

CONCLUSION

Although the available literature suggests ICBG and allograft may have similar effectiveness in terms of fusion rates, pain scores, and functional outcomes following anterior cervical fusion, there are too many limitations in the available literature to draw any significant conclusions. No individual study provided greater than class III evidence, and when evaluating the overall body of literature, no conclusion had better than low evidence support. A prospective randomized trial with adequate sample size to compare fusion rates, efficacy measures, costs, and safety is warranted.

Mesenchymal stromal cells in spinal fusion: Current and future applications

Mesenchymal stromal cells (MSCs) have been a promising area of study for regenerative medicine. These cells can be harvested from bone marrow, adipose tissue, and other areas allowing for autologous transplantation of these cells into the area of degeneration or injury. With the proper signals, these cells may be able to regenerate healthy tissue. Recent studies have yielded promising evidence supporting translational mesenchymal stromal cell applications particularly in spinal fusion surgery.

Betulinic acid synergically enhances BMP2-induced bone formation via stimulating Smad 1/5/8 and p38 pathways

BACKGROUND

Healing of bone defects is a dynamic and orchestrated process that relies on multiple growth factors and cell types. Bone morphogenetic protein 2 (BMP2) is a key growth factor for bone healing, which stimulates mesenchymal stem cells to differentiate into osteoblasts. Betulinic acid (BetA) is a natural pentacyclic triterpenoid from plants. This study aimed to examine combinatory effects of BetA and BMP2 on ectopic bone generation in mice.

RESULTS

In MC3T3-E1 preosteoblast culture, 10-15 μM of BetA increased the alkaline phosphatase (ALP) activity and expression levels of osteogenic marker genes without the decreased cell viability. In addition, BetA synergistically enhanced BMP2-induced gene expressions and mineralization with the enhancement of phosphorylation of Smad1/5/8 and p38. In an in vivo ectopic bone formation model, combination of BetA (50 μg) and BMP2 (3 μg) resulted in increases in the amount of new bone generation, compared with treatment with BMP2 alone. Histological studies showed that bone generation with cortical and trabecular structures was resulted from the combination of BetA and BMP2.

CONCLUSION

BetA can enhance in vivo osteogenic potentials of BMP2, possibly via stimulating Smad 1/5/8 and p38 pathways, and combination of both agents can be considered as a therapeutic strategy for bone diseases.

Efficacy of Postoperative Pain Management Using Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site in Patients with Adolescent Idiopathic Scoliosis: A Parallel, Double-Blinded, Randomized Controlled Pilot Trial

Study Design Randomized controlled trial. Objective Adolescent idiopathic scoliosis (AIS) is a common spinal deformity that affects every population. In severe deformity, surgical intervention is performed. Autogenous iliac crest bone graft (ICBG) harvesting remains a common procedure worldwide for scoliosis surgery. Postoperative pain at the ICBG donor site is a major concern in patients undergoing spine surgery that affects postoperative functional outcome and consumes health care resources. Previous studies have noted a decrease in pain and postoperative analgesic use with the application of continuous infusion of anesthetic at the ICBG site in comparison with placebo. However, there is lack of evidence addressing the efficacy of continuous anesthetic infusion at the ICBG site in young patients and in particular those with spinal deformity, such as AIS. As such, this parallel, double-blinded, randomized controlled trial addressed the pain management efficacy of continuous anesthetic infusion versus saline at the ICBG site in patients with AIS during the immediate postoperative period. Methods Participants were randomized into two groups. Group A (control subjects) received 3 mL per hour of saline locally at the ICBG site, and group B (treatment subjects) received a constant rate of infusion of 3 mL per hour of 0.25% levobupivacaine. Both groups received their postoperative intervention for 47 hours. All subjects and outcome assessors were blinded to the type of intervention. Utilizing the visual analog pain scale, pain was assessed at the primary spine surgical site, ICBG site, and contralateral ICBG site. Overall physical pain was assessed by the McGill Pain Questionnaire. The degree of analgesic use and complications were also evaluated. All outcomes were assessed up until the fourth day of the patients' hospitalization following surgery. Results Twelve subjects were recruited (five in group A; seven in group B). No difference was noted at baseline regarding age, weight, height, arm span, sex, curve type, instrumented and fused levels, length of hospitalization, and pain scores between groups. Postoperatively, no difference was noted in surgical site pain between groups (p > 0.05). However, decreased ICBG and contralateral ICBG pain decreased twofold in group B patients in comparison with group A. Similarly, group B subjects had notably decreased postoperative overall pain scores (group A, mean 15.3; group B, mean 3.8). No significant differences were noted for the pain scores due to the small sample size. Conclusions This study is the first with a robust level I study design to assess the efficacy of continuous infusion of analgesia into the ICBG site in young patients with AIS. This pilot study noted a trend that continuous anesthetic infusion reduces pain at the ICBG site and may further decrease overall physical bodily pain. This study further established a sample size calculation to facilitate large-scale studies addressing these parameters. This study provides further support of postoperative pain management options for children with spinal deformities.

Inflammation, fracture and bone repair

The reconstitution of lost bone is a subject that is germane to many orthopedic conditions including fractures and non-unions, infection, inflammatory arthritis, osteoporosis, osteonecrosis, metabolic bone disease, tumors, and periprosthetic particle-associated osteolysis. In this regard, the processes of acute and chronic inflammation play an integral role. Acute inflammation is initiated by endogenous or exogenous adverse stimuli, and can become chronic in nature if not resolved by normal homeostatic mechanisms. Dysregulated inflammation leads to increased bone resorption and suppressed bone formation. Crosstalk among inflammatory cells (polymorphonuclear leukocytes and cells of the monocyte-macrophage-osteoclast lineage) and cells related to bone healing (cells of the mesenchymal stem cell-osteoblast lineage and vascular lineage) is essential to the formation, repair and remodeling of bone. In this review, the authors provide a comprehensive summary of the literature related to inflammation and bone repair. Special emphasis is placed on the underlying cellular and molecular mechanisms, and potential interventions that can favorably modulate the outcome of clinical conditions that involve bone repair.

Iliac Crest Bone Graft in Lumbar Fusion: The Effectiveness and Safety Compared with Local Bone Graft, and Graft Site Morbidity Comparing a Single-Incision Midline Approach with a Two-Incision Traditional Approach

Study Design Systematic review. Clinical Questions (1) Is autologous local bone (LB) graft as safe and effective as iliac crest bone graft (ICBG) in lumbar spine fusion? (2) In lumbar fusion using ICBG, does a single-incision midline approach reduce postoperative iliac crest pain compared with a two-incision traditional approach? Methods Electronic databases and reference lists of key articles were searched up to October 2014 to identify studies reporting the comparative efficacy and safety of ICBG versus LB graft or comparing ICBG harvest site for use in lumbar spine surgery. Studies including allograft, synthetic bone, or growth factors in addition to ICBG and those with less than 80% of patients with degenerative disease in the lumbar spine were excluded. Two independent reviewers assessed the level of the evidence quality using the Grades of Recommendation Assessment, Development and Evaluation criteria, and disagreements were resolved by consensus. Results Seven studies were identified as using ICBG fusion for degenerative disease in the lumbar spine. There were no differences in the fusion, leg pain, low back pain, or functional outcomes between patients receiving LB versus ICBG. There was a higher incidence of donor site pain and sensory loss in patients receiving ICBG, with no donor site complications attributed to LB. Compared with patients with the graft harvested through the two-incision traditional approach, patients with the graft harvested through the single-incision midline approach had lower mean pain scores over the iliac crest, with a higher proportion reporting no iliac crest tenderness. In patients with ICBG harvested through the single-incision midline approach on either the right or the left side of the ilium, only 36% of the patients were able to correctly identify the side when asked whether they knew which iliac crest was harvested. Only 19% of the patients with ICBG harvested through the single-incision midline approach on either the right or the left side of the ilium reported pain that was concordant with the side that was actually harvested. Conclusions LB is as safe and efficacious as ICBG for instrumented fusion in the lumbar spine to treat degenerative disease. When ICBG is used, graft harvest through the single-incision midline approach reduces postoperative iliac crest pain compared with a two-incision approach.