Fracture rate after conventional external beam radiation therapy to the spine in multiple myeloma patients

BACKGROUND CONTEXT

Conventional external beam radiation therapy (cEBRT) is used in multiple myeloma (MM) to treat severe pain, spinal cord compression, and disease-related bone disease. However, radiation may be associated with an increased risk of vertebral compression fractures (VCFs), which could substantially impair survival and quality of life. Additionally, the use of the Spinal Instability Neoplastic Score (SINS) in MM is debated in MM.

PURPOSE

To determine the incidence of VCFs after cEBRT in patients with MM and to assess the applicability of the SINS score in the prediction of VCFs in MM.

STUDY DESIGN

Retrospective multicenter cohort study.

PATIENT SAMPLE

MM patients with spinal myeloma lesions who underwent cEBRT between January 2010 and December 2021.

OUTCOME MEASURES

Frequency of new or progressed VCFs and subdistribution hazard ratios for potentially associated factors.

METHODS

Patient and treatment characteristics were manually collected from the patients' electronic medical records. Computed tomography (CT) scans from before and up to 3 years after the start of radiation were used to score radiographic variables at baseline and at follow-up. Multivariable Fine and Gray competing risk analyses were performed to evaluate the diagnostic value of the SINS score to predict the postradiation VCF rate.

RESULTS

A total of 127 patients with 427 eligible radiated vertebrae were included in this study. The mean age at radiation was 64 years, and 66.1% of them were male. At the start of radiation, 57 patients (44.9%) had at least one VCF. There were 89 preexisting VCFs (18.4% of 483 vertebrae). Overall, 39 of 127 patients (30.7%) reported new fractures (number of vertebrae (n)=12) or showed progression of existing fractures (n=36). This number represented 11.2% of all radiated vertebrae. Five of the 39 (12.8%) patients with new or worsened VCFs received an unplanned secondary treatment (augmentation [n=2] or open surgery [n=3]) within 3 years. Both the total SINS score (SHR 1.77; 95% confidence interval (CI) 1.54-2.03; p<.001) and categorical SINS score (SHR 10.83; 95% CI 4.20-27.94; p<.001) showed an independent association with higher rates of new or progressed VCFs in adjusted analyses. The use of bisphosphonates was independently associated with a lower rate of new or progressed VCFs (SHR 0.47 [95% CI 0.24-0.92; p=.027]).

CONCLUSIONS

This study demonstrated that new or progressed VCFs occurred in 30.7% of patients within 3 years, in a total of 11.2% of vertebrae. The SINS score was found to be independently associated with the development or progression of VCFs and could thus be applied in MM for fracture prediction and possibly prevention.

Analysis of complications and revisions after spine surgery in 270 multiple myeloma patients with spinal involvement

BACKGROUND CONTEXT

Patients with multiple myeloma (MM) are at increased risk of infections and suffer from poor bone quality due to their disseminated malignant bone disease. Therefore, postoperative complications may occur following surgical treatment of MM lesions.

PURPOSE

In this study, we aimed to determine the incidence of postoperative complications and retreatments after spinal surgery in MM patients. Additionally, we sought to identify risk factors associated with complications and retreatments.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

In total, 270 patients with MM who received surgical treatment for spinal involvement between 2008 and 2021 were included.

OUTCOME MEASURES

The incidence of perioperative complications within 6 weeks and reoperations within 2.5 years and individual odds ratios for factors associated with these complications and reoperations.

METHODS

Data were collected through manual chart review. Hosmer and Lemeshow's purposeful regression method was used to identify risk factors for complications and reoperations.

RESULTS

The median age of our cohort was 65 years (SD = 10.8), and 58% were male (n = 57). Intraoperative complications were present in 24 patients (8.9%). The overall 6-week complication rate after surgery was 35% (n = 95). The following variables were independently associated with 6-week complications: higher Genant grading of a present vertebral fracture (OR 1.41; 95% CI 1.04-1.95; p = .031), receiving intramuscular or intravenous steroids within a week prior to surgery (OR 3.97; 95% CI 1.79-9.06; p = .001), decompression surgery without fusion (OR 6.53; 95% CI 1.30-36.86; p = .026), higher creatinine levels (OR 2.18; 95% CI 1.19-5.60; p = .014), and lower calcium levels (OR 0.58; 95% CI 0.37-0.88; p = .013). A secondary surgery was indicated for 53 patients (20%), of which 13 (4.8%) took place within two weeks after the initial surgery. We additionally discovered factors associated with retreatments, which are elucidated within the manuscript.

CONCLUSION

The goal of surgical treatment for MM bone disease is to enhance patient quality of life and reduce symptom burden. However, postoperative complication rates remain relatively high after spine surgery in patients with MM, likely attributable to both inherent characteristics of the disease and patient comorbidities. The risk for complications and secondary surgeries should be explored and a multidisciplinary approach is crucial.

Neurologic Outcomes After Radiation Therapy for Severe Spinal Cord Compression in Multiple Myeloma: A Study of 162 Patients

BACKGROUND

Bone destruction is the most frequent disease-defining clinical feature of multiple myeloma (MM), resulting in skeletal-related events such as back pain, pathological fractures, or neurologic compromise including epidural spinal cord compression (ESCC). Up to 24% of patients with MM will be affected by ESCC. Radiation therapy has been proven to be highly effective in pain relief in patients with MM. However, a critical knowledge gap remains with regard to neurologic outcomes in patients with high-grade ESCC treated with radiation.

METHODS

We retrospectively included 162 patients with MM and high-grade ESCC (grade 2 or 3) who underwent radiation therapy of the spine between January 2010 and July 2021. The primary outcome was the American Spinal Injury Association (ASIA) score after 12 to 24 months, or the last known ASIA score if the patient had had a repeat treatment or died. Multivariable logistic regression was used to assess factors associated with poor neurologic outcomes after radiation, defined as neurologic deterioration or lack of improvement.

RESULTS

After radiation therapy, 34 patients (21%) had no improvement in their impaired neurologic function and 27 (17%) deteriorated neurologically. Thirty-six patients (22%) underwent either surgery or repeat irradiation after the initial radiation therapy. There were 100 patients who were neurologically intact at baseline (ASIA score of E), of whom 16 (16%) had neurologic deterioration. Four variables were independently associated with poor neurologic outcomes: baseline ASIA (odds ratio [OR] = 6.50; 95% confidence interval [CI] = 2.70 to 17.38; p < 0.001), Eastern Cooperative Oncology Group (ECOG) performance status (OR = 6.19; 95% CI = 1.49 to 29.49; p = 0.015), number of levels affected by ESCC (OR = 4.02; 95% CI = 1.19 to 14.18; p = 0.026), and receiving steroids prior to radiation (OR = 4.42; 95% CI = 1.41 to 16.10; p = 0.015).

CONCLUSIONS

Our study showed that 38% of patients deteriorated or did not improve neurologically after radiation therapy for high-grade ESCC. The results highlight the need for multidisciplinary input and efforts in the treatment of high-grade ESCC in patients with MM. Future studies will help to improve patient selection for specific and standardized treatments and to clearly delineate which patients are likely to benefit from radiation therapy.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Neurological Outcomes and the Need for Retreatments Among Multiple Myeloma Patients With High-Grade Spinal Cord Compression: Radiotherapy vs Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Up to 30% of Multiple Myeloma (MM) patients are expected to experience Epidural Spinal Cord Compression (ESCC) during the course of their disease. To prevent irreversible neurological damage, timely diagnosis and treatment are important. However, debate remains regarding the optimal treatment regimen. The aim of this study was to investigate the neurological outcomes and frequency of retreatments for MM patients undergoing isolated radiotherapy and surgical interventions for high-grade (grade 2-3) ESCC.

METHODS

This study included patients with MM and high-grade ESCC treated with isolated radiotherapy or surgery. Pre- and post-treatment American Spinal Injury Association (ASIA) impairment scale and retreatment rate were compared between the 2 groups. Adjusted multivariable logistic regression was utilized to examine differences in neurologic compromise, pain, and retreatments.

RESULTS

A total of 247 patients were included (Radiotherapy: n = 154; Surgery: n = 93). After radiotherapy, 82 patients (53%) achieved full neurologic function (ASIA E) at the end of follow-up. Of the surgically treated patients, 67 (64%) achieved full neurologic function. In adjusted analyses, patients treated with surgery were less likely to experience neurologic deterioration within 2 years (OR = .15; 95%CI .05-.44; P = .001) and had less pain (OR = .29; 95%CI .11-.74; P = .010). Surgical treatment was not associated with an increased risk of retreatments (OR = .64; 95%CI .28-1.47; P = .29) or death (HR = .62, 95%CI .28-1.38; P = .24).

CONCLUSIONS

After adjusting for baseline differences, surgically treated patients with high-grade ESCC showed better neurologic outcomes compared to patients treated with radiotherapy. There were no differences in risk of retreatment or death.

Stereotactic Body radiotherapy and pedicLE screw fixatioN During one hospital visit for patients with symptomatic unstable spinal metastases: a randomized trial (BLEND RCT) using the Trials within Cohorts (TwiCs) design

BACKGROUND

Spinal metastases can lead to unremitting pain and neurological deficits, which substantially impair daily functioning and quality of life. Patients with unstable spinal metastases receive surgical stabilization followed by palliative radiotherapy as soon as wound healing allows. The time between surgery and radiotherapy delays improvement of mobility, radiotherapy-induced pain relief, local tumor control, and restart of systemic oncological therapy. Stereotactic body radiotherapy (SBRT) enables delivery of preoperative high-dose radiotherapy while dose-sparing the surgical field, allowing stabilizing surgery within only hours. Patients may experience earlier recovery of mobility, regression of pain, and return to systemic oncological therapy. The BLEND RCT evaluates the effectiveness of SBRT followed by surgery within 24 h for the treatment of symptomatic, unstable spinal metastases.

METHODS

This phase III randomized controlled trial is embedded within the PRospective Evaluation of interventional StudiEs on boNe meTastases (PRESENT) cohort. Patients with symptomatic, unstable spinal metastases requiring stabilizing surgery and radiotherapy will be randomized (1:1). The intervention group (n = 50) will be offered same-day SBRT and surgery, which they can accept or refuse. According to the Trial within Cohorts (TwiCs) design, the control group (n = 50) will not be informed and receive standard treatment (surgery followed by conventional radiotherapy after 1-2 weeks when wound healing allows). Baseline characteristics and outcome measures will be captured within PRESENT. The primary outcome is physical functioning (EORTC-QLQ-C15-PAL) 4 weeks after start of treatment. Secondary endpoints include pain response, time until return to systemic oncological therapy, quality of life, local tumor control, and adverse events up to 3 months post-treatment.

DISCUSSION

The BLEND RCT evaluates the effect of same-day SBRT and stabilizing surgery for the treatment of symptomatic, unstable spinal metastases compared with standard of care. We expect better functional outcomes, faster pain relief, and continuation of systemic oncological therapy. The TwiCs design enables efficient recruitment within an ongoing cohort, as well as prevention of disappointment bias and drop-out as control patients will not be informed about the trial.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05575323. Registered on October 11, 2022.

The incidence of vertebral compression fractures and spinal instability in newly diagnosed multiple myeloma patients

Background

Multiple myeloma (MM) is a hematologic malignancy, characterized by clonal proliferation of plasma cells in the bone marrow. These plasma cell proliferations frequently result in scattered osteolytic bone lesions and extensive skeletal destruction. Myeloma bone lesions are frequently located in the spine, and are associated with debilitating bone pain and an increased rate of pathologic fractures and mortality. The aim of this study was to investigate the incidence of vertebral compression fractures (VCFs) and spinal instability in patients with MM.

Patients and methods

Newly diagnosed patients with MM with computed tomography (CT) scans of the spine within three months of diagnosis were identified through an electronic patient database. Clinical baseline data were manually extracted from the patient charts. Fractured levels were graded on CT scans following the Genant grading system, and spinal instability was assessed through the Spinal Instability Neoplastic Score (SINS).

Results

A total of 385 patients with 6289 eligible vertebrae were eligible for inclusion. The mean age at diagnosis was 67 years, and 60% were male. At least one VCF was present in 180 patients (47%). A quarter of fractures were classified as severe. The incidence of fractures increased with more advanced disease stages, and men were more likely to have a fracture than women.

Conclusions

Our data show that 47% of MM patients present with one or more VCFs at the onset of their disease, of which 20% were classified as unstable, meaning a surgical consultation is recommended.

Long-term quality of life outcome after spondylodiscitis treatment

BACKGROUND CONTEXT

Spondylodiscitis is the most common spinal infection of which the incidence has increased and the peak prevalence is between 50 and 70 years of age. Spondylodiscitis is often a complication of a distant infection. Early diagnosis can be challenging, and although improvements in diagnostic techniques and modern therapy have diminished the mortality of the disease, current literature about the outcome of spondylodiscitis is scarce.

PURPOSE

To evaluate the long-term clinical outcome of patients who suffered from spondylodiscitis.

STUDY DESIGN

A two-center cross-sectional study.

PATIENT SAMPLE

Patients with spondylodiscitis in two large teaching hospitals in the Netherlands between 2003 and 2017.

OUTCOME MEASURES

Visual Analogue Scale (VAS) for back pain, Oswestry Disability Index (ODI) for function, and Short Form 36 (SF-36) for general quality of life of spondylodiscitis patients.

METHOD

Eligible patients were identified from electronic patient databases and completed multiple patient reported outcome measures after obtaining informed consent. General demographic and clinical information (age, sex, medical history) were extracted from the patient records. SF-36 domain scores of spondylodiscitis patients were compared with a nationwide population sample.

RESULTS

183 patients were treated for spondylodiscitis; additional questionnaires were received from 82 patients. After a median follow-up of 63 months, the overall mortality was 28%. The mean VAS for back pain was 3.5, and the mean ODI score was 22. In all SF-36 domains a significantly lower score was found in the spondylodiscitis group compared with a normative national Dutch cohort. There was a strong correlation between back pain and ODI scores (ρ=0.81, p<.05).

CONCLUSIONS

Our study confirms that spondylodiscitis is a disease causing a profound impact on back pain, function and quality of life. The results suggest that chronic back pain is a debilitating problem, as it has an extensive influence on daily activities and social and psychological well-being, causing significant disability.

Resident training does not influence the complication risk in total knee and hip arthroplasty

Background and purpose - Gaining experience in the surgery room during residency is an important part of learning the skills needed to perform arthroplasties. However, in practice, patients are often not fully comfortable with trainee involvement in their own surgery. Therefore, we investigated complications, revision rates, mortality, and operative time of orthopedic surgeons and residents as primary surgeon performing total knee arthroplasties (TKAs) or total hip arthroplasties (THAs).Patients and methods - In this multi-center retrospective cohort study, 3,098 TKAs and 4,027 THAs performed between 2007 and 2013 were analyzed. Complications, revisions, mortality, and operative time were compared for patients operated on by the orthopedic surgeon or a resident as primary surgeon. An additional analysis was performed to determine whether the complication risk was affected by the postgraduate year of the resident.Results - Orthopedic complication rates were similar (TKA: orthopedic surgeon: 10%, resident: 11%; THA: 9% and 8%), revision rates (TKA: 3% and 2%, THA: 3% and 2%), or mortality rates (TKA: 0.1% and 0.3%, THA: 0.2% and 0.3%). For both procedures a higher non-orthopedic complication rate was found in the resident group (TKA: 8% and 10%; p = 0.03, THA: 8% and 10%; p = 0.01) and a slightly longer operative time (TKA: mean difference 9.0 minutes (8%); THA: 11.3 minutes (11%)).Interpretation - Complications, revisions, and mortality were similar in TKAs or THAs performed by the resident as primary surgeon compared with surgeries performed by an orthopedic surgeon. This data can be used in teaching hospitals and may help to reassure patients.

Long-term (> 10 years) clinical outcomes of instrumented posterolateral fusion for spondylolisthesis

PURPOSE

Despite the rapid increase in instrumented spinal fusions for a variety of indications, most studies focus on short-term fusion rates. Long-term clinical outcomes are still scarce and inconclusive. This study investigated clinical outcomes > 10 years after single-level instrumented posterolateral spinal fusion for lumbar degenerative or isthmic spondylolisthesis with neurological symptoms.

METHODS

Cross-sectional long-term follow-up among the Dutch participants of an international multicenter randomized controlled trial comparing osteogenic protein-1 with autograft. Clinical outcomes were assessed using the Oswestry Disability Index (ODI), EQ-5D-3L and visual analogue scale (VAS) for leg and back pain, as well as questions on satisfaction with treatment and additional surgery.

RESULTS

The follow-up rate was 73% (41 patients). At mean 11.8 (range 10.1-13.7) years after surgery, a non-significant deterioration of clinical outcomes compared to 1-year follow-up was observed. The mean ODI was 20 ± 19, mean EQ-5D-3L index score 0.784 ± 0.251 and mean VAS for leg and back pain, respectively, 34 ± 33 and 31 ± 28. Multiple regression showed that diagnosis (degenerative vs. isthmic spondylolisthesis), graft type (OP-1 vs. autograft) and 1-year fusion status (fusion vs. no fusion) were not predictive for the ODI at long-term follow-up (p = 0.389). Satisfaction with treatment was excellent and over 70% of the patients reported lasting improvement in back and/or leg pain. No revision surgeries for non-union were reported.

CONCLUSION

This study showed favourable clinical outcomes > 10 years after instrumented posterolateral spinal fusion and supports spondylolisthesis with neurological symptoms as indication for fusion surgery.

Identifying predictive factors for vertebral collapse fractures in multiple myeloma patients

BACKGROUND CONTEXT

Vertebral compression fractures (VCFs) are a common complication for patients with multiple myeloma. These fractures are associated with significant morbidity and mortality due to severe back pain, spinal instability, increased risk of new fractures, neurologic dysfunction, and other physical symptoms.

PURPOSE

To identify risk factors associated with the development of VCFs which may help to predict them in future patients.

STUDY DESIGN

A retrospective multicenter cohort study.

PATIENT SAMPLE

Patients with multiple myeloma diagnosed between 2012 and 2018 and appropriate baseline- and follow-up imaging studies (>6 months after diagnosis) were included.

OUTCOME MEASURES

Individual odds ratios for each of the fifteen potential risk factors including patient factors and radiographical characteristics.

METHODS

Relevant clinical baseline data were extracted from the patient charts. Computed tomography (CT) scans were used to score all radiographic variables. VCFs were graded following the Genant grading system. General Linear Mixed Models were used to analyze risk factors associated with vertebral fractures.

RESULTS

A total of 143 patients with 1,605 eligible vertebrae were included in the study with a mean follow-up time of 25 months. Mean age at diagnosis was 65 years and 39% were female. Among 1,605 vertebrae, there were 192 (12%) VCFs (Genant grade 1 or higher) at the time of diagnosis and 111 (7%) occurred during follow-up. In a General Linear Mixed Model, significant predictors were gender (odds ratio [OR]=1.5), International Staging System stage 2 and 3 (OR=3.6 and OR=4.1 respectively), and back pain (OR=2.7). Furthermore, lower Hounsfield Unit score, lytic lesions and abnormal alignment were risk factors for (the development of) VCFs.

CONCLUSIONS

This study investigated both patient characteristics and vertebra-specific risk factors for VFCs in multiple myeloma patients. The factors found in this study might be useful for identifying patients at higher risk of VFCs to help clinical management to prevent vertebral collapse and the development of spinal deformities.

Neurological Outcome After Traumatic Transverse Sacral Fractures: A Systematic Review of 521 Patients Reported in the Literature

BACKGROUND

The purpose of this study was to determine the neurological outcome after transverse sacral fractures in patients with neurological impairment.

METHODS

A systematic review of the English, French, German, and Dutch literature was conducted. All study designs, including retrospective cohort studies and case reports, describing transverse sacral fractures were included. Two authors independently extracted the predefined data and scored the neurological impairment according to the Gibbons classification after the trauma and at the time of follow-up. The neurological outcomes were pooled according to the Gibbons classification.

RESULTS

No randomized controlled trials or prospective case series were found. A total of 139 articles were included, consisting of 81 case reports and 58 retrospective case series involving 521 patients. Regardless of the type of management, neurological recovery of at least 1 Gibbons category was reported in 62% of these patients. A comparison of the neurological outcome of nonoperatively treated patients and surgically treated patients showed similar neurological recovery rates. For the surgically treated patients, fixation of the fracture resulted in a better neurological improvement compared with an isolated decompression.

CONCLUSIONS

This review could not provide evidence of improved neurological recovery after surgical treatment compared with nonoperative treatment. When surgical treatment was considered, there was a low level of evidence that fixation of the fracture results in better neurological improvement compared with isolated decompression.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The lateral femoral notch sign: a reliable diagnostic measurement in acute anterior cruciate ligament injury

PURPOSE

To describe the validity and inter- and intra-observer reliability of the lateral femoral notch sign (LFNS) as measured on conventional radiographs for diagnosing acute anterior cruciate ligament (ACL) injury.

METHODS

Patients (≤ 45 years) with a traumatic knee injury who underwent knee arthroscopy and had preoperative radiographs were retrospectively screened for this case-control study. Included patients were assigned to the ACL injury group (n = 65) or the control group (n = 53) based on the arthroscopic findings. All radiographs were evaluated for the presence, depth and location of the LFNS by four physicians who were blind to the conditions. To calculate intra-observer reliability, each observer re-assessed 25% of the radiographs at a 4-week interval.

RESULTS

The depth of the LFNS was significantly greater in ACL-injured patients than in controls [median 0.8 mm (0-3.1 mm) versus 0.0 mm (0-1.4 mm), respectively; p = 0.008]. The inter- and intra-observer reliabilities of the LFNS depth were 0.93 and 0.96, respectively. Secondary knee pathology (i.e., lateral meniscal injury) in ACL-injured patients was correlated with a deeper LFNS [median 1.1 mm (0-2.6 mm) versus 0.6 mm (0-3.1 mm), p = 0.012]. Using a cut-off value of 1 mm for the LFNS depth, a positive predictive value of 96% was found.

CONCLUSION

This was the first study to investigate the inter- and intra-observer agreement of the depth and location of the LFNS. The depth of the LFNS had a very high predictive value for ACL-injured patients and could be used in the emergency department without any additional cost. A depth of > 1.0 mm was a good predictor for ACL injury. Measuring the depth of the LFNS is a simple and clinically relevant tool for diagnosing ACL injury in the acute setting and should be used by clinicians in patients with acute knee trauma.

LEVEL OF EVIDENCE

Diagnostic study, level II.

OP-1 Compared with Iliac Crest Autograft in Instrumented Posterolateral Fusion: A Randomized, Multicenter Non-Inferiority Trial

BACKGROUND

Spinal fusion with the use of autograft is a commonly performed procedure. However, harvesting of bone from the iliac crest is associated with complications. Bone morphogenetic proteins (BMPs) are extensively used as alternatives, often without sufficient evidence of safety and efficacy. The purpose of this study was to investigate non-inferiority of osteogenic protein-1 (OP-1, also known as BMP-7) in comparison with iliac crest bone graft in posterolateral fusions.

METHODS

This study was a randomized, controlled multicenter trial. Patients who underwent a single-level instrumented posterolateral fusion of the lumbar spine for degenerative or isthmic spondylolisthesis with symptoms of neurological compression were randomized to receive OP-1 combined with local bone (OP-1 group) or autologous bone graft from the iliac crest combined with local bone (autograft group). The primary outcome was overall success, defined as a combination of clinical success and evidence of fusion on computed tomography (CT) scans, at one year postoperatively.

RESULTS

One hundred and nineteen patients were included in the study, and analysis of the overall outcome was performed for 113. Non-inferiority of OP-1 compared with iliac crest autograft was not found at one year, with a success rate of 40% in the OP-1 group versus 54% in the autograft group (risk difference = -13.3%, 90% confidence interval [CI] = -28.6% to +2.10%). This was due to the lower rate of fusion (the primary aim of OP-1 application) seen on the CT scans in the OP-1 group (54% versus 74% in the autograft group, p = 0.03). There were no adverse events that could be directly related to the use of OP-1.

CONCLUSIONS

OP-1 with a collagen carrier was not as effective as autologous iliac crest bone for achieving fusion and cannot be recommended in instrumented posterolateral lumbar fusion procedures.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Extension type fracture of the ankylotic thoracic spine with gross displacement causing esophageal rupture

PURPOSE

This study aimed at discussing the relevance of the type B3 fracture of the new AOSpine classification.

METHODS

Hyperextension fractures of the spine are rare in the general population, but common in the ankylotic spine. We present a case of a severe spinal fracture with concomitant esophageal rupture, which was diagnosed early and could be treated during the initial trauma care.

RESULTS

The spinal column was stabilized using a percutaneous technique after which the perforated esophagus was sutured through a thoracotomy. The spinal injury was classified a type B3 fracture using the new AOSpine classification.

CONCLUSION

The B3 typification raised a lot of discussion during the development of the new classification system and may be controversial. This case, however, nicely illustrates the relevance of an intact posterior hinge as compared to C-type injuries where complete dissociation is present with inherent spinal cord damage.

No correlation between slip reduction in low-grade spondylolisthesis or change in neuroforaminal morphology and clinical outcome

Background

In instrumented posterolateral fusion reduction of a spondylolisthesis is appealing on theoretical grounds since this may lead to indirect decompression of the entrapped nerve roots. However, there is no consensus in the literature whether a beneficial effect of reduction on outcome can be expected. The objective of the current study was to evaluate whether a correlation between the extent of listhesis reduction and clinical improvement could be established.

Methods

From two ongoing prospective studies 72 patients with a single-level instrumented posterolateral lumbar fusion for low-grade spondylolisthesis (isthmic/degenerative 51/21) were evaluated. Radiographs and clinical outcome scores were available at baseline, 6 weeks and 1 year after surgery. Changes in neuroforaminal morphology were measured on calibrated radiographs. These changes in radiographic parameters were correlated to clinical outcome (Visual Analogue Score (VAS) leg pain, Oswestry Disability Index (ODI)). Fusion status was assessed on Computed Tomography-scan at one year.

Results

A mean spondylolisthesis of 25 percent was reduced to 15 percent at 6 weeks with some loss of reduction to 17 percent at one year. The VAS and ODI significantly improved at both time intervals after surgery (p < 0.001). No significant correlations could be established between the extent of slip reduction and improvement in VAS or ODI (Pearson’s correlation −0.2 and 0.07 respectively at one year); this also accounted for the other radiographic parameters. A fusion rate of 64 percent was seen on CT-scan.

Conclusions

Clinical outcome was not related to the obtained radiographic reduction of the slipped vertebra in patients with a lumbar fusion for low grade spondylolisthesis. Loss of reduction or non-union on CT-scans had no effect on the clinical outcome. Reduction of a low-grade spondylolisthesis in spinal fusion is appealing, however, there is no evidence that it positively affects clinical outcome on the short term.

Trial registration

ISRCTN43648350

Natural antibodies against bone morphogenic proteins and interferons in healthy donors and in patients with infections linked to type-1 cytokine responses

In patients receiving recombinant therapeutic proteins, the production of antibodies against the therapeutics is a rising problem. The antibodies can neutralize and interfere with the efficacy and safety of drugs and even cause severe side effects if they cross-react against the natural, endogenous protein. Various factors have been identified to influence the immunogenic potential of recombinant human therapeutics, including several patients' characteristics. In recent years, so-called naturally occurring antibodies against cytokines and growth factors have been detected in naive patients before start of treatment with recombinant human therapeutics. The role of naturally occurring antibodies is not well understood and their influence on production of anti-drug antibodies is not known. One might speculate that the presence of naturally occurring antibodies increases the likelihood of eliciting anti-drug antibodies once treatment with the corresponding recombinant therapeutic protein is started. We screened serum samples from 410 healthy controls and patients for auto-antibodies against bone morphogenetic proteins (BMPs) 2 and 7 and interferon (IFN)-α, -β, and -γ in a new 3-step approach: rough initial screening, followed by competition and protein A/G depletion. Naturally occurring antibodies against these proteins were detected in 2% to 4% of the tested sera. Individuals who are 65 years or older had a slightly higher occurrence of naturally occurring antibodies. Auto-antibodies against BMP-7 and IFN-α were mainly comprised of IgM isotypes, and natural antibodies against BMP-2, IFN-β, and -γ were mainly IgG. To ensure assay specificity, assays were also used to detect antibodies against BMP-7 in patients being treated with rhBMP-7 before and after surgical procedure. Fifty percent of the treated patients had persistent anti-BMP-7 antibodies over time. The 3-step approach provides an attractive tool to identify naturally occurring antibodies in naive patients.

Relevance of bone graft viability in a goat transverse process model

Little is known about the mechanism by which autologous bone grafts are so successful. The relevance of viable osteogenic cells, which is a prominent difference between autologous bone graft and conventional alternatives, is especially controversial. With the emergence of bone tissue engineering, knowledge of the exact role of these cells has become crucial. The most obvious question to answer is whether viability of the graft has an effect on bone formation. In the current study, we investigated this effect of bone graft viability in a transverse process model that represents the initial bone formation in posterolateral spinal fusion. Eight goats received viable and devitalized autologous bone grafts in chambers mounted on the decorticated lumbar transverse processes. In addition, five goats received empty chambers. Histology and histomorphometry were performed after a 12-week implantation, and the dynamics of bone formation was monitored by sequential fluorochrome labeling. An obvious qualitative effect of viability was demonstrated by the presence of early onset osteogenesis distant from the transverse process bone in the viable grafts only. Quantitative analysis indicated about 30% more bone in the viable grafts, however, this difference was not statistically significant. In the empty chambers, bone was found in comparable quantities. We conclude that there is a qualitative advantage of graft viability in terms of early graft-derived osteogenesis. However, this advantage did not lead to significantly more bone formation in the viable bone grafts.

Platelet leukocyte gel facilitates bone substitute growth and autologous bone growth in a goat model

The aim of this study is to evaluate multiple conditions on the formation of bone growth in a goat model. We prepared from a unit of whole blood, platelet-leukocyte gel (PLG) to stimulate bone formation, based on the release of platelet growth factors. Two 3-compartment cages containing autologous bone, calcium phosphate, and trabecular metal were implanted onto goat spinal transverse processes. One cage was treated with PLG, prepared according to a standardized protocol. An untreated cage served as a control. To monitor bone formation overtime, fluorochrome markers were administered at 2, 3, and 5 weeks. Animals were sacrificed at 9 weeks after implantation. Bone growth in these 3-compartments cages was examined by histology and histomorphometry of nondecalcified sections using traditional light and epifluorescent microscopy. Compared to the control samples, bone growth in the PLG-treated autologous bone and calcium phosphate samples was significantly more. Fairly little bone growth was seen in PLG treated or untreated trabecular metal scaffolds. The results obtained from this goat model suggest a potential role for the application of autologous PLG during surgeries in which autologous bone grafts or calcium phosphate scaffolds are used.

The incidence of donor site pain after bone graft harvesting from the posterior iliac crest may be overestimated: a study on spine fracture patients

STUDY DESIGN

A retrospective cohort study on patients with traumatic vertebral fractures who underwent fusion with iliac crest bone.

OBJECTIVE

To evaluate the influence of low back surgery on donor site attributed pain, we compared donor site pain between patients who underwent high and low level fusions.

SUMMARY OF BACKGROUND DATA

The most common complication of posterior iliac crest bone graft harvesting is postoperative pain at the donor site. The incidence of donor site pain after bone graft harvesting from the posterior iliac crest is mainly reported from studies in patients who underwent low lumbar or lumbosacral surgery. The close proximity of the primary surgery to the iliac crest could interfere with the reported incidence of donor site pain.

METHODS

Questionnaires regarding the iliac crest morbidity were sent to patients who underwent instrumented posterolateral fusion after traumatic spinal fractures. The incidence of donor site attributed pain was compared between patients whose fusion was between T2 and L2, with patients whose fusion extended to L3 or more caudally.

RESULTS

In patients with a fusion of high levels, the donor site pain was significantly lower compared with patients with fusion of low levels (14.3% vs. 40.9%).

CONCLUSION

Patients probably cannot differentiate between donor site pain and residual low back pain. The reported incidence of pain related to posterior iliac crest bone graft harvesting may therefore be overestimated.

Intra-individual variations of fasting plasma lipids, apolipoproteins and postprandial lipemia in familial combined hyperlipidemia compared to controls

BACKGROUND

The intra-individual variability of plasma lipids and apolipoproteins has not been studied systematically in familial combined hyperlipidemia (FCHL).

METHODS

Intra-individual changes in fasting plasma lipids and apolipoproteins B and AI were determined in 18 untreated FCHL subjects and 16 unrelated, normolipidemic subjects. Participants were matched for gender, age and body mass index. The mean follow-up period of fasting plasma lipids was 48.91 +/- 35.46 (mean +/- S.D.) days. Postprandial lipemia was determined on 3 different days in 1 week in 90 healthy controls and 17 untreated FCHL subjects by the area under the diurnal capillary triglyceride curve (TGc-AUC).

RESULTS

The coefficients of variation (CVs) for fasting plasma TG were similar between FCHL (23.2 +/- 10.2%) and controls (20.4 +/- 8.2%). The CVs for HDL-C, apo B and apo AI were the lowest of all fasting plasma measurements in both groups and there was no significant difference between FCHL (12.8 +/- 8.2%, 13.2 +/- 15.8% and 6.4 +/- 5.2%, respectively) and controls (11.4 +/- 4.3%, 11.3 +/- 10.6% and 7.8 +/- 4.6%, respectively). The CVs for postprandial lipemia were not different between FCHL (15.9 +/- 11.3%) and controls (15.1 +/- 11.0%), and were significantly lower than the CV of fasting capillary TG (TGc) in the same period (36.3 +/- 24.7% and 24.9 +/- 17.2%, respectively).

CONCLUSIONS

Our study does not provide evidence for short-term major changes in fasting or postprandial lipemia or apolipoproteins in FCHL when systematically compared to healthy controls.