Predicting and Promoting Human Bone Marrow MSC Chondrogenesis by Way of TGFß Receptor Profiles: Toward Personalized Medicine.

The use of human mesenchymal stromal cells (hMSCs) for cartilage regeneration has been hampered by the inherent donor variation of primary monolayer expanded cells. Although CD markers are typically used to characterize cell populations, there is no correlation between CD marker profile and functional outcomes. Therefore, we aimed to discover novel predictive MSC chondrogenesis markers. The chondrogenic potential of primary human bone marrow MSCs (hBMSCs) over multiple passages was assessed by standard pellet culture. We confirmed that the ratio of TGFß-RI/TGFß-RII at the time of cell recovery from the tissue culture plastic reliably predicted chondrogenic potential. Furthermore, it is possible to prospectively characterize any human BMSC cell population as responders or non-responders with respect to chondrogenic differentiation potential. Transient increase of the ratio with siRNA knockdown of TGFß-RII reproducibly recovered the chondrogenic differentiation ability of non-responsive MSCs. Together this offers an opportunity to produce a more functionally characterized cell population for use in autologous cartilage repair therapies.

Preclinical ex-vivo Testing of Anti-inflammatory Drugs in a Bovine Intervertebral Degenerative Disc Model.

Discogenic low back pain (LBP) is a main cause of disability and inflammation is presumed to be a major driver of symptomatic intervertebral disc degeneration (IDD). Anti-inflammatory agents are currently under investigation as they demonstrated to alleviate symptoms in patients having IDD. However, their underlying anti-inflammatory and regenerative activity is poorly explored. The present study sought to investigate the potential of Etanercept and Tofacitinib for maintaining disc homeostasis in a preclinical intervertebral disc (IVD) organ culture model within IVD bioreactors allowing for dynamic loading and nutrient exchange. Bovine caudal IVDs were cultured in a bioreactor system for 4 days to simulate physiological or degenerative conditions: (1) Phy-physiological loading (0.02-0.2 MPa; 0.2 Hz; 2 h/day) and high glucose DMEM medium (4.5 g/L); (2) Deg+Tumor necrosis factor α (TNF-α)-degenerative loading (0.32-0.5 MPa; 5 Hz; 2 h/day) and low glucose DMEM medium (2 g/L), with TNF-α injection. Etanercept was injected intradiscally while Tofacitinib was supplemented into the culture medium. Gene expression in the IVD tissue was measured by RT-qPCR. Release of nitric oxide (NO), interleukin 8 (IL-8) and glycosaminoglycan (GAG) into the IVD conditioned medium were analyzed. Cell viability in the IVD was assessed using lactate dehydrogenase and ethidium homodimer-1 staining. Immunohistochemistry was performed to assess protein expression of IL-1ß, IL-6, IL-8, and collagen type II in the IVD tissue. Etanercept and Tofacitinib downregulated the expression of IL-1ß, IL-6, IL-8, Matrix metalloproteinase 1 (MMP1), and MMP3 in the nucleus pulposus (NP) tissue and IL-1ß, MMP3, Cyclooxygenase-2 (COX2), and Nerve growth factor (NGF) in the annulus fibrosus (AF) tissue. Furthermore, Etanercept significantly reduced the IL-1ß positively stained cells in the outer AF and NP regions. Tofacitinib significantly reduced IL-1ß and IL-8 positively stained cells in the inner AF region. Both, Etanercept and Tofacitinib reduced the GAG loss to the level under physiological culture condition. Etanercept and Tofacitinib are able to neutralize the proinflammatory and catabolic environment in the IDD organ culture model. However, combined anti-inflammatory and anabolic treatment may be required to constrain accelerated IDD and relieving inflammation-induced back pain.

Possible advantages of early stabilization of spinal fractures in multiply injured patients with leading thoracic trauma - analysis based on the TraumaRegister DGU®.

BACKGROUND: Major trauma often comprises fractures of the thoracolumbar spine and these are often accompanied by relevant thoracic trauma. Major complications can be ascribed to substantial simultaneous trauma to the chest and concomitant immobilization due to spinal instability, pain or neurological dysfunction, impairing the respiratory system individually and together. Thus, we proposed that an early stabilization of thoracolumbar spine fractures will result in significant benefits regarding respiratory organ function, multiple organ failure and length of ICU / hospital stay. METHODS: Patients documented in the TraumaRegister DGU®, aged ≥16 years, ISS ≥ 16, AISThorax ≥ 3 with a concomitant thoracic and / or lumbar spine injury severity (AISSpine) ≥ 3 were analyzed. Penetrating injuries and severe injuries to head, abdomen or extremities (AIS ≥ 3) led to patient exclusion. Groups with fractures of the lumbar (LS) or thoracic spine (TS) were formed according to the severity of spinal trauma (AISspine): AISLS = 3, AISLS = 4-5, AISTS = 3 and AISTS = 4-5, respectively. RESULTS: 1740 patients remained for analysis, with 1338 (76.9%) undergoing spinal surgery within their hospital stay. 976 (72.9%) had spine surgery within the first 72 h, 362 (27.1%) later on. Patients with injuries to the thoracic spine (AISTS = 3) or lumbar spine (AISLS = 3) significantly benefit from early surgical intervention concerning ventilation time (AISLS = 3 only), ARDS, multiple organ failure, sepsis rate (AISTS = 3 only), length of stay in the intensive care unit and length of hospital stay. In multiple injured patients with at least severe thoracic spine trauma (AISTS ≥ 4) early surgery showed a significantly shorter ventilation time, decreased sepsis rate as well as shorter time spend in the ICU and in hospital. CONCLUSIONS: Multiply injured patients with at least serious thoracic trauma (AISThorax ≥ 3) and accompanying spine trauma can significantly benefit from early spine stabilization within the first 72 h after hospital admission. Based on the presented data, primary spine surgery within 72 h for fracture stabilization in multiply injured patients with leading thoracic trauma, especially in patients suffering from fractures of the thoracic spine, seems to be beneficial.

Preoperative Assessment of Neural Elements in Lumbar Spinal Stenosis by Upright Magnetic Resonance Imaging: An Implication for Routine Practice?

Introduction Lumbar spinal stenosis (LSS) is a kinetic-dependent disease typically aggravating during spinal loading. To date, assessment of LSS is usually performed with magnetic resonance imaging (MRI). However, conventional supine MRI is associated with significant drawbacks as it does not truly reflect physiological loads, experienced by discoligamentous structures during erect posture. Consequently, supine MRI often fails to reveal the source of pain and/or disability caused by LSS. The present study sought to assess neural dimensions via MRI in supine, upright, and upright-hyperlordotic position in order to evaluate the impact of patient positioning on neural narrowing. Therefore, radiological measures such as neuroforaminal dimensions, central canal volume, sagittal listhesis, and lumbar lordosis at spinal level L4/5 were extracted and stratified according to patient posture. Materials and methods Overall, 10 subjects were enclosed in this experimental study. MRI was performed in three different positions: (1) 0° supine (SP), (2) 80° upright (UP), and (3) 80° upright + hyperlordotic (HY) posture. Upright MRI was conducted utilizing a 0.25T open-configuration scanner equipped with a rotatable examination bed allowing for true standing MRI. Radiographic outcome of upright MRI imaging was extracted and evaluated according to patient positioning. Results Upright MRI-based assessment of neural dimensions was successfully accomplished in all subjects. Overall, radiographic parameters revealed a significant decrease of neural dimensions from supine to upright position: Specifically, mean foraminal area decreased from SP to UP by 13.3% (P ≤ 0.05) as well as from SP to HY position by 21% (P ≤ 0.05). Supplementation of hyperlordosis did not result in additional narrowing of neural elements (P ≥ 0.05). Furthermore, central canal volume revealed a decrease of 7% at HY and 8% at UP compared to SP position (P ≥ 0.05). Assessment of lumbar lordosis yielded in a significant increase when assessed at HY (+22.1%) or UP (+8.7%) compared to SP (P ≤ 0.05). Conclusions Our data suggest that neuroforaminal dimensions assessed by conventional supine MRI are potentially overestimated in patients with LSS. Especially, in patients having occult disease not visualized on conventional imaging modalities, upright MRI allows for a precise, clinically relevant, and at the same time non-invasive evaluation of neural elements in LSS when neural decompression is considered.

An intervertebral disc whole organ culture system to investigate proinflammatory and degenerative disc disease condition.

The aim of this study was to compare the effect of different disease initiators of degenerative disc disease (DDD) within an intervertebral disc (IVD) organ culture system and to understand the interplay between inflammation and degeneration in the early stage of DDD. Bovine caudal IVDs were cultured within a bioreactor for up to 11 days. Control group was cultured under physiological loading (0.02-0.2 MPa; 0.2 Hz; 2 hr/day) and high glucose (4.5 g/L) medium. Detrimental loading (0.32-0.5 MPa, 5 Hz; 2 hr/day) and low glucose (2 g/L) medium were applied to mimic the condition of abnormal mechanical stress and limited nutrition supply. Tumour necrosis factor alpha (TNF-α) was injected into the nucleus pulposus (100 ng per IVD) as a proinflammatory trigger. TNF-α combined with detrimental loading and low glucose medium up-regulated interleukin 1ß (IL-1ß), IL-6, and IL-8 gene expression in disc tissue, nitric oxide, and IL-8 release from IVD, which indicate a proinflammatory effect. The combined initiators up-regulated matrix metalloproteinase 1 gene expression, down-regulated gene expression of Type I collagen in annulus fibrosus and Type II collagen in nucleus pulposus, and reduced the cell viability. Furthermore, the combined initiators induced a degradative effect, as indicated by markedly higher glycosaminoglycan release into conditioned medium. The combination of detrimental dynamic loading, nutrient deficiency, and TNF-α intradiscal injection can synergistically simulate the proinflammatory and degenerative disease condition within DDD. This model will be of high interest to screen therapeutic agents in further preclinical studies for early intervention and treatment of DDD.

The Potential for Synovium-derived Stem Cells in Cartilage Repair.

BACKGROUND: Articular cartilage defects often result in pain, loss of function and finally osteoarthritis. Developing cell-based therapies for cartilage repair is a major goal of orthopaedic research. Autologous chondrocyte implantation is currently the gold standard cell-based surgical procedure for the treatment of large, isolated, full thickness cartilage defects. Several disadvantages such as the need for two surgical procedures or hypertrophic regenerative cartilage, underline the need for alternative cell sources. OBJECTIVE: Mesenchymal stem cells, particularly synovium-derived mesenchymal stem cells, represent a promising cell source. Synovium-derived mesenchymal stem cells have attracted considerable attention since they display great chondrogenic potential and less hypertrophic differentiation than mesenchymal stem cells derived from bone marrow. The aim of this review was to summarize the current knowledge on the chondrogenic potential for synovial stem cells in regard to cartilage repair purposes. RESULTS: A literature search was carried out identifying 260 articles in the databases up to January 2017. Several in vitro and initial animal in vivo studies of cartilage repair using synovia stem cell application showed encouraging results. Since synvoium-derived stem cells are located in the direct vicinity of cartilage and cartilage lesions these cells might even contribute to natural cartilage regeneration. The only one published human in vivo study with 10 patients revealed good results concerning postoperative outcome, MRI, and histologic features after a two-stage implantation of synovial stem cells into an isolated cartilage defect of the femoral condyle. CONCLUSION: Synovium-derived stem cells possess great chondrogenic potential and showed encouraging results for cartilage repair purposes. Furthermore, synovial stem cells play an important role in joint homeostasis and possibly in natural cartilage repair. Further studies are needed to elucidate the interplay of synovial stem cells and chondrocytes, and the promising role of synovium-derived stem cells in cartilage tissue engineering.

Upcoming Paralympic summer games in Rio: what did the German medical team learn from the London Games?

BACKGROUND: Musculoskeletal complaints are frequently diagnosed in Paralympic athletes. Despite the increased professionalism in Paralympic Sports, the documentation of injuries and other health complaints during high-level competition is sparse. With respect to the upcoming Paralympic Summer Games in Rio de Janeiro, the aim of this study was the analysis of all musculoskeletal complaints within the German Paralympic Athletes during the London 2012 Paralympic Games. METHODS: All musculoskeletal complaints (MSC) of the 150 German athletes seeking medical attention, hereby defined as "injury", were recorded during the in-competition period of the London Paralympics Games (22 days), regardless of their severity and consequences. Standardized documentation included the onset of symptoms, the medical diagnoses, the therapeutic measures taken as well as consecutive restrictions in training and competition. Incidence rates and localizations were analyzed by sports discipline. RESULTS: A total of 201 musculoskeletal complaints were recorded for 140 athletes (93.3%), corresponding to 1.4 musculoskeletal complaints per "injured" athlete. The incidence of musculoskeletal complaints in German athletes was 62.9±15.4/1000 athlete-days. High incidence rates (IR) were observed in wheelchair basketball (IR 72/1000 athlete-days, 1.6 injuries per athlete) and equestrian events (IR 72.7, 1.6). Musculoskeletal complaints were mainly located in the upper extremities (37.6%) and the spine (37.6%). The most frequent diagnoses were myalgia (N.=105, 52%). CONCLUSIONS: We noted a high rate of musculoskeletal complaints among German Paralympic athletes across sports and body parts, highlighting the need for prevention programs that focus on the upper extremities and spine.

Clinical outcome and T2 assessment following autologous matrix-induced chondrogenesis in osteochondral lesions of the talus.

PURPOSE: Scientific evidence for the treatment of osteochondral lesions (OCLs) of the talus is limited. The aim of this study was an evaluation of the clinical outcome after a one-step autologous subchondral cancellous bone graft and autologous matrix-induced chondrogenesis (AMIC) in medial OCLs of the talus and the assessment of the repair tissue (RT). METHODS: Seventeen patients (eight women, nine men; mean age, 38.8 ± 15.7 years) with an OCL of the medial talus underwent surgery. Clinical and radiological assessment was performed after a mean follow-up of 39.5 ± 18.4 months, including established scoring systems (American Orthopaedic Foot and Ankle Society [AOFAS] Score, Foot Function Index [FFI], visual analogue scale [VAS]), evaluation of Magnetic Resonance Observation of Cartilage Repair Tissue scoring system (MOCART Score) and T2 mapping. RESULTS: Preoperative pain (7.8 ± 2.1) significantly improved to an average of 3.2 ± 2.4 postoperatively. AOFAS Score averaged 82.6 ± 13.4, MOCART Score 52.7 ± 15.9. Mean T2 relaxation time of the RT was 41.6 ± 6.3 ms and showed no significant differences to the surrounding cartilage (mean, 38.8 ± 8.5; p = 0.58). MOCART Score significantly correlated with the AOFAS Score (rho = 0.574, p = 0.040). T2 relaxation time of the RT significantly correlated with the MOCART Score (rho = 0.593, p = 0.033). CONCLUSIONS: The one-step autologous subchondral cancellous bone grafting and AMIC leads to a significant reduction in postoperative pain and satisfying postoperative functional outcome in mid-term follow-up. Magnetic resonance imaging (MRI) assessment demonstrated a good quality of regenerative tissue similar to the MRI ultrastructure of the surrounding cartilage.

The Lumbar Spine as a Dynamic Structure Depicted in Upright MRI.

Spinal canal stenosis is a dynamic phenomenon that becomes apparent during spinal loading. Current diagnostic procedures have considerable short comings in diagnosing the disease to full extend, as they are performed in supine situation. Upright MRI imaging might overcome this diagnostic gap.This study investigated the lumbar neuroforamenal diameter, spinal canal diameter, vertebral body translation, and vertebral body angles in 3 different body positions using upright MRI imaging.Fifteen subjects were enrolled in this study. A dynamic MRI in 3 different body positions (at 0° supine, 80° upright, and 80° upright + hyperlordosis posture) was taken using a 0.25 T open-configuration scanner equipped with a rotatable examination bed allowing a true standing MRI.The mean diameter of the neuroforamen at L5/S1 in 0° position was 8.4 mm on the right and 8.8 mm on the left, in 80° position 7.3 mm on the right and 7.2 mm on the left, and in 80° position with hyperlordosis 6.6 mm (P < 0.05) on the right and 6.1 mm on the left (P < 0.001).The mean area of the neuroforamen at L5/S1 in 0° position was 103.5 mm on the right and 105.0 mm on the left, in 80° position 92.5 mm on the right and 94.8 mm on the left, and in 80° position with hyperlordosis 81.9 mm on the right and 90.2 mm on the left.The mean volume of the spinal canal at the L5/S1 level in 0° position was 9770 mm, in 80° position 10600 mm, and in 80° position with hyperlordosis 9414 mm.The mean intervertebral translation at level L5/S1 was 8.3 mm in 0° position, 9.9 mm in 80° position, and 10.1 mm in the 80° position with hyperlordosis.The lordosis angle at level L5/S1 was 49.4° in 0° position, 55.8° in 80° position, and 64.7 mm in the 80° position with hyperlordosis.Spinal canal stenosis is subject to a dynamic process, that can be displayed in upright MRI imaging. The range of anomalies is clinically relevant and dynamic positioning of the patient during MRI can provide essential diagnostic information which are not attainable with other methods.

Long-term T2 and Qualitative MRI Morphology After First-Generation Knee Autologous Chondrocyte Implantation: Cartilage Ultrastructure Is Not Correlated to Clinical or Qualitative MRI Outcome.

BACKGROUND: There are several reports on long-term clinical outcomes after autologous chondrocyte implantation (ACI) for knee cartilage defect treatment. Few published articles have evaluated defect quality using quantitative magnetic resonance (MR) imaging techniques. PURPOSE: To evaluate clinical outcomes and the quality of repair tissue (RT) after first-generation periosteum-covered ACI (ACI-P) using qualitative MR outcomes and T2-weighted relaxation times. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: All patients (n = 86) who underwent knee joint ACI-P (from 1997 through 2001) with a postoperative follow-up of at least 10 years were invited for clinical and MR evaluation. Clinical outcomes analysis included pre- and postoperative Lysholm and numeric analog scale (NAS) for pain (10 = worst, 0 = best). Radiographic analysis included postoperative T2-weighted mapping of the RT, RT-associated regions, and healthy control cartilage; MOCART (magnetic resonance observation of cartilage repair tissue) score; a modified Knee Osteoarthritis Scoring System (mKOSS; 0 = best, 15 = worst) score; as well as numeric grading for subjective RT and whole knee joint evaluation (1 = best, 6 = worst). RESULTS: A total of 70 patients (45 male, 25 female; mean age, 33.3 ± 10.2 years; 81% follow-up rate) with 82 defects were available for follow-up at an average 10.9 ± 1.1 years postoperatively, with MR analysis for 59 patients with 71 transplant sites (average defect size, 6.5 ± 4.0 cm(2)). Final Lysholm (71.0 ± 17.4) and NAS (7.2 ± 1.9) scores improved significantly when compared with preoperative scores (Lysholm: 42.0 ± 22.5; NAS: 2.1 ± 2.1; P < .01 for both). Average transplant T2 was 35.2 ± 11.3 ms and thereby significantly lower (P = .005) when compared to the intraknee healthy femur T2 (39.7 ± 6.8 ms). The MOCART was 44.9 ± 23.6 and mKOSS was 4.8 ± 3.2. RT subjective grading was 3.3 ± 1.4, while it was 2.3 ± 0.7 for whole joint evaluation. The RT T2 significantly correlated with postoperative NAS (P = .04; r = -0.28); it also correlated with the healthy femur T2 (P = .004; r = 0.4). The MOCART significantly correlated with the mKOSS (P < .001). CONCLUSION: The MRI outcome is imperfect in this collective of patients. There is only weak correlation of quantitative imaging data and clinical function. Qualitative imaging data are much better correlated to functional outcomes.

The floating shoulder­-clinical and radiological results after intramedullary stabilization of the clavicle in cases with minor displacement of the scapular neck fracture.

BACKGROUND: The aim of this study was to compare the clinical and radiologic results of titanium elastic nail (TEN) and plate osteosynthesis for treatment of clavicle fractures in patients with a floating shoulder injury. PATIENTS AND METHODS: From 2000 to 2008, 16 patients with a floating shoulder injury (ipsilateral clavicle and minor displaced scapular neck fracture) were treated by isolated stabilization of the clavicle. The patients were treated with open reduction and plate osteosynthesis (group 1[G1]) or TEN osteosynthesis (group 2 [G2]). Both procedures were compared with regard to functional and radiologic outcome. RESULTS: Nine patients were treated with a plate osteosynthesis (G1) and seven with a TEN osteosynthesis (G2). The follow-up time was 35.7 months ± 16 months. There was no difference in functional outcome with regard to the intraindividual Constant score 83.9(G1) versus 86.7 (G2) or the American Shoulder and Elbow Surgeons score 79.1 (G1) versus 85.7 (G2). No significant postoperative dislocation of the glenopolar angle appeared. In the TEN-treated group, a clavicle shortening of 2.4 mm was observed. Subgroup analysis revealed significant greater shortening in type B and C compared with type A (OTA) clavicle fractures(4.7 mm vs. 0.8 mm). No clavicle shortening in the plate-treated group appeared. CONCLUSION: The treatment of floating shoulder injuries with TEN and plate osteosynthesis of the clavicle and nonoperative treatment of a minimally displaced glenoid neck fracture provide equal functional results. However, in type B and C (but not in type A) fractures of the clavicle, a shortening of 5 mm can be expected after titanium elastic nailing.

Risk of graft fracture after dorso-ventral thoraco-lumbar spondylodesis: is there a correlation with graft size?

STUDY DESIGN: Retrospective clinical study in patients with dorso-ventral thoraco-lumbar spondylodesis. OBJECTIVE: To investigate whether the ratio between graft cross sectional area and the surface area of the adjacent endplates has any effect on the midterm stability of the spondylodesis. Dorso-ventral spondylodesis in the region of the thoraco-lumbar spine is one of the most frequent operations in orthopaedic surgery. Anterior stabilization with autologous iliac crest graft currently is a standard approach in many hospitals. Although numerous recommendations are given how to perform this technique, no clinical advice is available with regard to minimum graft size. METHODS: Sixty-four-slice CT-scans were obtained from 82 patients 4-12 months after posterior spondylodesis with anterior implantation of iliac crest graft and stabilization with an internal fixator. The scans were analyzed using image analysis software. First, the cross sectional area of the graft was calculated and then the surface area of the adjacent endplates. The ratio between graft cross sectional area and endplate surface area was then calculated from these two values. The grafts were then evaluated in sagittal reconstruction for signs of fracture. RESULTS: The probability for graft fracture in autologous tricortical grafts was >0.1% (p < 0.001) if the graft cross sectional area exceeded 23.9% of the surface area of the adjacent endplates. Patients with lower ratio values had a higher fracture risk and below a value of 10% all grafts fractured. CONCLUSION: The relationship between graft cross sectional area and adjacent endplate area has an important effect on graft midterm stability in ventral spondylodesis of the thoraco-lumbar spine. In our opinion, the risk of graft fractures in dorso-ventral spondylodesis can be reduced by implantation of an appropriately sized graft without any additional procedures or instrumentation.

Effect of graft size on graft fracture rate after anterior lumbar spinal fusion in a sheep model.

STUDY DESIGN: Sheep anterior spinal fusion model with autogenous and xenogenous bone grafts. OBJECTIVE: To investigate whether the relationship between cross-sectional area of the bone graft and area of the adjacent vertebral endplates has an effect on graft fracture rate. SUMMARY OF BACKGROUND DATA: Anterior spondylodesis with autogenous iliac crest transplant is a frequently performed operation to stabilize spinal motion segments but to date no precise recommendations with respect to minimum graft size are available in the literature. METHODS: Anterior spondylodesis using autogenous and xenogenous grafts of constant size in combination with an angular stable plate (Macs TL). Autogenous iliac crest graft was inserted in eight sheep and xenogenic, commercially available bovine graft (Tutobone) in the additional eight animals. The surface areas of the endplates of the fused intervertebral space were calculated using CT scans and contact radiographs of the specimens obtained after 24 weeks. The graft itself was evaluated for fractures and osteolysis. RESULTS: A fracture occurred in tricortical, autogenous grafts if the graft cross-sectional area was less than 21% of the area of the adjacent endplates. All xenogenic grafts fractured and therefore a comparable value could not be determined. CONCLUSION: The results clearly indicate that the relation between graft cross-sectional area and endplate area defines the survival or fracture of the graft in anterior spinal fusion. Although it is difficult to directly apply the results to the clinical situation it is suggested to choose a sufficiently large graft, in order to reduce the risk of autogenous graft fracture in anterior spondylodesis.

Detection of bone graft failure in lumbar spondylodesis: spatial resolution with high-resolution peripheral quantitative CT.

OBJECTIVE: In spinal surgery, anterior spondylodesis is often combined with bone grafting, and graft integration is assessed with CT. High-resolution peripheral quantitative CT offers a resolution of 82 mum. The aim of this study was to compare the outcome of anterior spondylodesis as assessed with three radiologic procedures. MATERIALS AND METHODS: Monosegmental lumbar spondylodesis with autologous iliac crest graft or solvent-preserved bovine cancellous bone was performed on seven sheep. The fused spinal segments were explanted after 24 weeks and examined with clinical 64-MDCT, high-resolution peripheral quantitative CT, and contact radiography. In 2D views, the area of the disk space bridged by bone was assessed, and the grafts were examined for fractures. RESULTS: In three of seven sheep, clinical CT erroneously showed stable consolidation, whereas contact radiography revealed a clearly visible graft fracture, as did high-resolution peripheral quantitative CT. There was a statistically significant difference (p = 0.038) between bone volume assessed with clinical CT and that assessed with contact radiography. There was an almost significant difference (p = 0.053) between volumes assessed with high-resolution peripheral quantitative CT and clinical MDCT. CONCLUSION: High-resolution peripheral quantitative CT, a technique approved for clinical use, has higher resolution in imaging of bone structure than does 64-MDCT. Our results show that high-resolution peripheral quantitative CT is superior to 64-MDCT in assessing osseous implant integration after anterior spondylodesis. The specimen size limit, however, prohibits in vivo use of this method in evaluation of the human spine. Our results suggest that in clinical practice, persisting symptoms despite radiologic findings of consolidated spondylodesis may be related to graft failure, which cannot be detected with clinically available methods.