Development of a machine-learning based model for predicting multidimensional outcome after surgery for degenerative disorders of the spine.

BACKGROUND: It is clear that individual outcomes of spine surgery can be quite heterogeneous. When consenting a patient for surgery, it is important to be able to offer an individualized prediction regarding the likely outcome. This study used a comprehensive set of data collected over 12 years in an in-house registry to develop a parsimonious model to predict the multidimensional outcome of patients undergoing surgery for degenerative pathologies of the thoracic, lumbar or cervical spine. METHODS: Data from 8374 patients (mean age 63.9 (14.9-96.3) y, 53.4% female) were used to develop a model to predict the 12-month scores for the Core Outcome Measures Index (COMI) and its subdomain scores. The data were split 80:20 into a training and test set. The top predictors were selected by applying recursive feature elimination based on LASSO cross validation models. Based on the 111 top predictors (contained within 20 variables), Ridge cross validation models were trained, validated, and tested for each of 9 outcome domains, for patients with either "Back" (thoracic/lumbar spine) or "Neck" (cervical spine) problems (total 18 models). RESULTS: Among the strongest outcome predictors in most models were: preoperative scores for almost all COMI items (especially axial pain (back or neck) and peripheral pain (leg/buttock or arm/shoulder)), catastrophizing, fear avoidance beliefs, comorbidity, age, BMI, nationality, previous spine surgery, type and spinal level of intervention, number of affected levels, and surgeon seniority. The R2 of the models on the validation/test sets averaged 0.16/0.13. A preliminary online tool was programmed to present the predicted outcomes for individual patients, based on their presenting characteristics. https://linkup.kws.ch/prognostictool . CONCLUSION: The models provided estimates to enable a bespoke prediction of the outcome of surgery for individual patients with varying degenerative pathologies and baseline characteristics. The models form the basis of a simple, freely-available online prognostic tool developed to improve access to and usability of prognostic information in clinical practice. It is hoped that, following confirmation of its validity and practical utility, the tool will ultimately serve to facilitate decision-making and the management of patients' expectations.

Development of a mapping function ("crosswalk") for the conversion of scores between the Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI).

INTRODUCTION: The Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI) are two commonly used self-rating outcome instruments in patients with lumbar spinal disorders. No formal crosswalk between them exists that would otherwise allow the scores of one to be interpreted in terms of the other. We aimed to create such a mapping function. METHODS: We performed a secondary analysis of ODI and COMI data previously collected from 3324 patients (57 ± 17y; 60.3% female) at baseline and 1y after surgical or conservative treatment. Correlations between scores and Cohen's kappa for agreement (κ) regarding achievement of the minimal clinically important change (MCIC) score on each instrument (ODI, 12.8 points; COMI, 2.2 points) were calculated, and regression models were built. The latter were tested for accuracy in an independent set of registry data from 634 patients (60 ± 15y; 56.8% female). RESULTS: All pairs of measures were significantly positively correlated (baseline, 0.73; 1y follow-up (FU), 0.84; change-scores, 0.73). MCIC for COMI was achieved in 53.9% patients and for ODI, in 52.4%, with 78% agreement on an individual basis (κ = 0.56). Standard errors for the regression slopes and intercepts were low, indicating excellent prediction at the group level, but root mean square residuals (reflecting individual error) were relatively high. ODI was predicted as COMI × 7.13-4.20 (at baseline), COMI × 6.34 + 2.67 (at FU) and COMI × 5.18 + 1.92 (for change-score); COMI was predicted as ODI × 0.075 + 3.64 (baseline), ODI × 0.113 + 0.96 (FU), and ODI × 0.102 + 1.10 (change-score). ICCs were 0.63-0.87 for derived versus actual scores. CONCLUSION: Predictions at the group level were very good and met standards justifying the pooling of data. However, we caution against using individual values for treatment decisions, e.g. attempting to monitor patients over time, first with one instrument and then with the other, due to the lower statistical precision at the individual level. The ability to convert scores via the developed mapping function should open up more centres/registries for collaboration and facilitate the combining of data in meta-analyses.

Patient-rated outcome after atlantoaxial (C1-C2) fusion: more than a decade of evaluation of 2-year outcomes in 126 patients.

INTRODUCTION: Various surgical techniques have been introduced for atlantoaxial (C1-C2) fusion, the most common being Magerl's (transarticular) or the Harms/Goel screw fixation. Common indications include degenerative osteoarthritis (OA), trauma or rheumatoid arthritis (RA). Only few, small studies have evaluated patient-reported outcomes after C1-C2 fusion. We investigated 2-year outcomes in a large series of consecutive patients undergoing isolated C1-C2 fusion. METHODS: We analysed prospectively collected data (2005-2016) from our Spine outcomes database, collected within the framework of EUROSPINE's Spine Tango Registry. It included 126 patients (34 (27%) men, 92 (73%) women; mean (SD) age 67 ± 19 y) who had undergone first-time isolated C1-C2 fusion (61% Magerl, 39% Harms(-Goel)) at least 2 years ago for OA (83 (66%)), RA (20 (16%)), fracture (15 (12%)) or other (8 (6%)). Patients completed the multidimensional Core Outcome Measures Index (COMI; 0-10) and various single item outcomes. RESULTS: Questionnaires were returned by 118/126 (94%) patients, 2 years post-operative. Mean COMI scores showed a significant reduction from baseline: 6.9 ± 2.4 to 2.7 ± 2.5 (p < 0.0001). Overall, 75% patients achieved the MCIC of ≥ 2.2 points reduction in COMI and 88% reported a good global outcome. 91% patients were satisfied/very satisfied with their care. Self-reported complications were declared by 16% patients and further surgery at the same segment, by 2.5%. CONCLUSION: In this large series with almost complete follow-up, C1-C2 fusion showed extremely good results. Despite the complexity of the intervention, outcomes surpassed those typically reported for simple procedures such as ACDF and lumbar discectomy, suggesting reservations about the procedure should perhaps be reviewed.

What level of symptoms are patients with adult spinal deformity prepared to live with? A cross-sectional analysis of the 12-month follow-up data from 1043 patients.

INTRODUCTION: Previous studies suggest that a meaningful and easily understood measure of treatment outcome may be the proportion of patients who are in a "patient acceptable symptom state" (PASS). We sought to quantify the score equivalent to PASS for different outcome instruments, in patients with adult spinal deformity (ASD). METHODS: We analysed the following 12-month questionnaire data from the European Spine Study Group (ESSG): Oswestry Disability Index (ODI; 0-100); Numeric Rating Scales (NRS; 0-10) for back/leg pain; Scoliosis Research Society (SRS) questionnaire; and an item "if you had to spend the rest of your life with the symptoms you have now, how would you feel about it?" (5-point scale, dichotomised with top 2 responses "somewhat satisfied/very satisfied" being considered PASS+, everything else PASS-). Receiver operating characteristics (ROC) analyses indicated the cut-off scores equivalent to PASS+. RESULTS: Out of 1043 patients (599 operative, 444 non-operative; 51 ± 19 years; 84% women), 42% reported being PASS+ at 12 months' follow-up. The ROC areas under the curve were 0.71-0.84 (highest for SRS subscore), suggesting the questionnaire scores discriminated well between PASS+ and PASS-. The scores corresponding to PASS+ were > 3.5 for the SRS subscore (> 3.3-3.8 for SRS subdomains); ≤ 18 for ODI; and ≤ 3 for NRS pain. There were slight differences in cut-offs for subgroups of age, treatment type, aetiology, baseline symptoms, and sex. CONCLUSION: Most interventions for ASD improve patients' complaints but do not totally eliminate them. Reporting the percentage achieving a score equivalent to an "acceptable state" may represent a more stringent and discerning target for denoting treatment success in ASD. These slides can be retrieved under Electronic Supplementary Material.

How does patient-rated outcome change over time following the surgical treatment of degenerative disorders of the thoracolumbar spine?

PURPOSE: Patient-rated measures are considered the gold standard for assessing the outcome of spine surgery, but there is no consensus on the appropriate timing of follow-up. Journals often demand a minimum 2-year follow-up, but the indiscriminate application of this principle may not be warranted. We examined the course of change in patient outcomes up to 5 years after surgery for degenerative spinal disorders. METHODS: The data were evaluated from 4287 consecutive patients (2287 women, 2000 men; aged 62 ± 15 years) with degenerative disorders of the thoracolumbar spine, undergoing first-time surgery at the given level between 01/01/2005 and 31/12/2011. The Core Outcome Measures Index (COMI; scored 0-10) was completed by 4012 (94%) patients preoperatively, 4008 (93%) at 3-month follow-up, 3897 (91%) at 1-year follow-up, 3736 (87%) at 2-year follow-up, and 3387 (79%) at 5-year follow-up. 2959 (69%) completed the COMI at all five time-points. RESULTS: The individual COMI change scores from preoperatively to the various follow-up time-points showed significant correlations ranging from r = 0.50 (for change scores at the earliest vs the latest follow-up) to r = 0.75 (for change scores after 12- vs 24-month follow-up). Concordance with respect to whether the minimum clinically important change score was achieved at consecutive time-points was also good (70-82%). COMI decreased significantly (p < 0.05) from preop to 3 months (by 3.6 ± 2.8 points) and from 3 to 12 months (by 0.3 ± 2.4 points), then levelled off up to 5 years (0.04-0.05 point change; p > 0.05). The course of change up to 12 months differed slightly (p < 0.05) depending on pathology/whether fusion was carried out. For patients undergoing simple decompression, 3-month follow-up was sufficient; those undergoing fusion continued to show further slight but significant change up to 12 months. CONCLUSIONS: Stable group mean COMI scores were observed for all patients from 12 months postoperatively onwards. The early postoperative results appeared to herald the longer term outcome. As such, a 'wait and see policy' in patients with a poor initial outcome at 3 months is not advocated. The insistence on a 2-year follow-up could result in a failure to intervene early to achieve better long-term outcomes.

Adult degenerative scoliosis: comparison of patient-rated outcome after three different surgical treatments.

PURPOSE: Few studies have examined the effectiveness of surgical treatment for adult degenerative scoliosis (ADS) using validated patient-orientated outcome instruments. This study reports patient outcomes in a large, consecutive series of patients being treated for ADS by simple decompression (D), short fusion (SF), or long fusion (LF). METHODS: Our local spine surgery database (part of the Eurospine Spine Tango Registry) was used to acquire the data from patients with ADS undergoing D, SF or LF. Preoperatively and at 12 and 24 months follow-up (FU), patients completed the multidimensional Core Outcome Measures Index (COMI; 0-10); at FU, satisfaction and global outcome were rated on a five-point Likert scale and dichotomised as "good" and "poor", and patient-rated complications were recorded. RESULTS: 173 patients took part (81 D, 53 SF, 39 LF). Compared with the two fusion groups, the D group was significantly older, had more comorbidity, and had more leg pain than back pain (each p < 0.05). There were significant differences among the groups for operation duration, blood loss and general complications (each p < 0.05), in each case with the LF group showing the greatest values and the D group the lowest values. However, patient-rated complications were not significantly different between the groups (p > 0.89). Further surgery within the 2-year follow-up was required in 7 % of the D group, 15 % in SF and 28 % in LF. All groups benefited significantly from surgery with no significant differences (p > 0.05) between them: improvement in COMI after 24 months was 2.9 ± 2.8 points for D, 3.1 ± 3.3 points for SF and 3.2 ± 3.1 points for LF; a "good global outcome" was recorded for 69, 74 and 76 % patients, respectively. CONCLUSIONS: Despite the complexity of the disease, patient-orientated outcomes after surgery for ADS were similar to those previously reported using the same outcome instruments in patients with lumbar stenosis and degenerative spondylolisthesis. The use of D, SF and LF for ADS yielded similarly good results from the patient's perspective. This most likely reflects careful and appropriate patient selection. Further analyses are warranted to identify baseline variables predicting the 26-31 % cases in each group with a poor outcome.

[Chronic recurrent multifocal osteomyelitis of the spine : Children and adolescent]. / Chronische rekurrierende multifokale Osteomyelitis der Wirbelsäule : Kindes- und Jugendalter.

Chronic non-bacterial osteomyelitis (CNO) in childhood and adolescence is a non-infectious autoinflammatory disease of the bone with partial involvement of adjacent joints and soft tissue. The etiology is unknown. The disease can occur singular or recurrent. Individual bones can be affected and multiple lesions can occur. Chronic recurrent multifocal osteomyelitis (CRMO) shows the whole picture of CNO. Accompanying but temporally independent of the bouts of osteomyelitis, some patients show manifestations in the skin, eyes, lungs and the gastrointestinal tract. The article gives an overview of the clinical manifestations, diagnostic procedures, and treatment options for CRMO involvement of the spine based on the current literature and our own cases.

[Congenital malformations of the growing spine : When should treatment be conservative and when should it be surgical?]. / Kongenitale Fehlbildungen der Wirbelsäule im Wachstum : Wann konservativ behandeln, wann operativ?

Congenital malformations of the spine are caused by genetic and teratogenic factors. By means of asymmetrical longitudinal growth of the spine they can lead to deformity, most commonly to scoliosis. The malformations can be classified as failure of formation, failure of segmentation and mixed-type malformations. The extent of the deformity and its progression are determined by the remaining growth potential and the location and type of malformation. Up to one third of such deformities are associated with some sort of cardiac or urogenital malformation. The treatment concept is typically determined on an individual basis. Mild deformities often remain undetected. Conservative treatment using a brace has no substantial effect on the primary curve but might be helpful in the treatment of long sweeping, flexible, secondary curves. If rapid progression is documented or expected, surgical intervention as early as possible is warranted to prevent secondary structural changes. The surgical treatment should be focused on and limited to the site of malformation. The aim of surgery is the correction of the deformity at the site of asymmetrical growth. This can be achieved either by resection of a hemivertebra or by performing a vertebral column resection or other type of osteotomy. If notable compensatory, secondary curves are present, these can be corrected with growing rod constructs. The aim of all types of treatment is the correction of existing deformity or the prevention of its progression, in order to ensure balanced growth of the healthy regions of the spine. The present paper discusses the conservative and surgical treatment modalities available to achieve these aims.

Higher fibrinogen concentrations for reduction of transfusion requirements during major paediatric surgery: A prospective randomised controlled trial.

BACKGROUND: Hypofibrinogenaemia is one of the main reasons for development of perioperative coagulopathy during major paediatric surgery. The aim of this study was to assess whether prophylactic maintenance of higher fibrinogen concentrations through administration of fibrinogen concentrate would decrease the volume of transfused red blood cell (RBCs). METHODS: In this prospective, randomised, clinical trial, patients aged 6 months to 17 yr undergoing craniosynostosis and scoliosis surgery received fibrinogen concentrate (30 mg kg(-1)) at two predefined intraoperative fibrinogen concentrations [ROTEM(®) FIBTEM maximum clot firmness (MCF) of <8 mm (conventional) or <13 mm (early substitution)]. Total volume of transfused RBCs was recorded over 24 h after start of surgery. RESULTS: Thirty children who underwent craniosynostosis surgery and 19 children who underwent scoliosis surgery were treated per protocol. During craniosynostosis surgery, children in the early substitution group received significantly less RBCs (median, 28 ml kg(-1); IQR, 21 to 50 ml kg(-1)) compared with the conventional fibrinogen trigger of <8 mm (median, 56 ml kg(-1); IQR, 28 to 62 ml kg(-1)) (P=0.03). Calculated blood loss as per cent of estimated total blood volume decreased from a median of 160% (IQR, 110-190%) to a median of 90% (IQR, 78-110%) (P=0.017). No significant changes were observed in the scoliosis surgery population. No bleeding events requiring surgical intervention, postoperative transfusions of RBCs, or treatment-related adverse events were observed. CONCLUSIONS: Intraoperative administration of fibrinogen concentrate using a FIBTEM MCF trigger level of <13 mm can be successfully used to significantly decrease bleeding, and transfusion requirements in the setting of craniosynostosis surgery, but not scoliosis. CLINICAL TRIAL REGISTRY NUMBER: ClinicalTrials.gov NCT01487837.

Posterior vertebral column resection in early onset spinal deformities.

PURPOSE: Early onset spinal deformities (EOSD) can be life-threatening in very young children. In the growing spine, surgical intervention is often unavoidable and should be carried out as soon as possible. A deformed section of the spine not only affects the development of the remaining healthy spine, but also that of the chest wall (which influences pulmonary function), the extremities and body balance. Posterior vertebral column resection (PVCR) represents an effective surgical solution to address such problems. However, reports in the literature concerning PVCR are mostly limited to its use in adolescents or adults. The purpose of this study was to illustrate our experience with PVCR in EOSD and to describe the surgical technique with respect to the unique anatomy of young children. MATERIALS AND METHODS: Four children [mean age 3.7 (range 2.5-5.2) years] with severe spinal deformity underwent PVCR through a single approach. Multimodal intraoperative monitoring was used in all cases. Surgery included one stage posterior circumferential resection of one vertebral body along with the adjoining intervertebral discs and removal of all posterior elements. A transpedicular screw-rod system was used for correction and stabilisation. Fusion was strictly limited to the resection site, allowing for later conversion into a growing rod construct at the remaining spine, if necessary. Relevant data were extracted retrospectively from patient charts and long spine radiographs. RESULTS: The mean operation time was 500 (range 463-541) min, with an estimated blood loss of 762 (range 600-1,050) ml. Mean follow-up time was 6.3 (range 3.5-12.4) years. After PVCR, the mean Cobb angle for scoliosis was reduced from 69° (range 50-99°) to 29° (5-44°) and the sagittal curvature (kyphosis) from 126° (87-151°) to 61° (47-75°). The mean correction of scoliosis was 57 % (18-92°) and of kyphosis, 51 % (44-62°). There were no spinal cord-related complications. In three patients, spinal instrumentation for growth guidance (fusion less growing rod technique) was applied. Two patients had complications: one patient had a complication of anesthesia, halo pin failure, and revision surgery with extension of the instrumentation cranially due to loss of correction; the second patient had a postoperative infection, which required plastic reconstructive measures. CONCLUSION: PVCR appears to be an effective technique to treat severe EOSD. There are important differences in its use in young children when compared with older patients. In patients with EOSD, additional surgical procedures are often necessary during growth, and hence non-fusion instrumentation beyond the vertebral resection site is advantageous, as it permits spinal growth and the later addition of fusion.

Validity of a single-item measure to assess leg or back pain as the predominant symptom in patients with degenerative disorders of the lumbar spine.

PURPOSE: Recent studies suggest that the location of predominant pain (back or leg) can be a significant predictor of the outcome of surgery for degenerative spinal disorders. However, others challenge the notion that the predominant symptom can be reliably identified. This study examined the validity of a single item used to determine the most troublesome symptom. METHODS: A total of 2,778 patients with degenerative disorders of the lumbar spine scheduled for surgery with the goal of pain relief completed a questionnaire enquiring as to their most troublesome symptom ["main symptom"; back pain (BACK) or leg/buttock pain (LEG)]. They also completed separate 0-10 graphic rating scales for back pain (LBP) and leg/buttock pain (LP) intensity. Receiver operating characteristics (ROC) analysis was used to determine the accuracy with which the "LP minus LBP" score was able to classify patients into their declared "main symptom" group. Sub-studies evaluated the test-retest reliability of the patients' self-rated pain scores (N = 45) and the agreement between the main symptom declared by the patient in the questionnaire and that documented by the surgeon after the clinical consultation (N = 118). RESULTS: Test-retest reliability of the back and leg pain scores was good (ICC2,1 of 0.8 for each), as was patient-surgeon agreement regarding the main symptom (BACK or LEG) (κ value 0.79). In the BACK group, the mean values for pain intensity were 7.3 ± 2.0 (LBP) and 5.2 ± 2.9 (LP); in the LEG group, they were 4.3 ± 2.9 (LBP) and 7.5 ± 1.9 (LP). The area under the curve for the ROC was 0.95 (95 % CI 0.94-0.95), indicating excellent discrimination between the BACK and LEG groups based on the "LP minus LBP" scores. A cutoff score >0.0 for "LP minus LBP" score gave optimal sensitivity and specificity for indicating membership of the LEG group (sensitivity 79.1%, specificity 95.7%). CONCLUSIONS: The responses on the single item for the "main symptom" were in good agreement with the differential ratings on the 0-10 pain scales for LBP and LP intensity. The cutoff >0 for "LP minus LBP" for classifying patients as LEG pain predominant seemed appropriate and suggests good concurrent validity for the single-item measure. The single item may be of use in sub-grouping patients with the same disorder (e.g. spondylolisthesis) or as an indication in surgical decision-making.

The influence of comorbidity on the risks and benefits of spine surgery for degenerative lumbar disorders.

PURPOSE: The ageing of the population will see a growing number of patients presenting for spine surgery with appropriate indications but numerous medical comorbidities. This complicates decision-making, requiring that the likely benefit of surgery (outcome) be carefully weighed up against the potential risk (complications). We assessed the influence of comorbidity on the risks and benefits of spine surgery. METHODS: 3,549/4,053 patients with degenerative lumbar disorders, undergoing surgery with the goal of pain relief, completed the multidimensional Core Outcome Measures Index (COMI; scored 0-10) before and 12 months after surgery. At 12 months postoperatively, they also rated the global treatment outcome and their satisfaction with care. Using the Eurospine Spine Tango Registry, surgeons documented surgical details, American Society of Anesthesiologists comorbidity (ASA) grades and perioperative surgical and general complications. RESULTS: 29.0% patients were rated as ASA1 (normal healthy), 45.7% as ASA2 (mild/moderate systemic disease), 24.9% as ASA3 (severe), and just 0.4% as ASA4 (life-threatening). In going from ASA1 to ASA3 (ASA4 group too small), surgical complications increased significantly from 5.0 to 14.5% and general complications increased from 2.9 to 15.7%; 12-month outcomes showed a corresponding decline, with a good global outcome being reported by 79% ASA1 patients, 76% ASA2, and 68% ASA3. Satisfaction with treatment was 87, 85, and 79%, respectively, and reduction in COMI was 4.2 ± 2.9, 3.7 ± 3.0, and 3.4 ± 3.0 points, respectively. Multiple regression analysis revealed a significant (p < 0.0001) independent effect of ASA grade on both complications and outcome. CONCLUSION: The negative impact of comorbidity on the outcome of spine surgery has not been well investigated/quantified to date. The ASA grade may be helpful in producing algorithms for decision-making and preoperative counselling regarding the corresponding risks and benefits of surgery.

[Results-adapted operative treatment options for spinal metastases]. / Befundadaptierte operative Versorgungsmöglichkeiten bei Wirbelsäulenmetastasen.

The current operative approaches and technical possibilities in the operative treatment of spinal metastases are manifold which enables an individual operative strategy adapted to the patient's condition. Maintaining quality of life is the primary goal in the treatment of these patients. The therapeutic goals, such as pain control, avoidance of neurological deficits and the achievement of spinal stability have to be attained with as little morbidity as possible. From this perspective the available operative techniques ranging from minimally invasive approaches to complex reconstructive surgery will be addressed and discussed in this article.

[Tumors and metastases of the upper cervical spine (C0-2). A special challenge]. / Tumoren und Metastasen der oberen Halswirbelsäule (C0-2). Eine besondere Herausforderung.

Tumors of the upper cervical spine are rare and represent less than 0.5 % of all spinal tumors. The types of tumor and the clinical presentation are as varied as the modalities used for treatment. The unique anatomy of the upper cervical spine with its high physical mobility means that biomechanical considerations and neighboring anatomical structures (e.g. vertebral artery, medulla oblongata, lower cranial nerves and pharynx) must be considered when creating a treatment plan. Finding a balance between complete tumor removal, the preservation and reestablishment of stability and function and the possible necessity for postoperative radiotherapy is of utmost importance and must be assessed on an individual basis. In this review paper some important points will be presented concerning the preparation of the patient, the planning of the operation and the surgical approach used in treating tumors of the craniocervical junction.

Fusionless posterior hemivertebra resection in a 2-year-old child with 16 years follow-up.

PURPOSE: We present the case of a 2-year-old patient with congenital scoliosis due to a lumbar hemivertebra. The current gold standard treatment of such an abnormality would be hemivertebra resection and short level posterior spinal fusion. However, due to the young age of the patient, we considered that application of a fusionless solution might offer advantages in terms of retaining normal segmental motion and the potential for growth. METHODS: The incarcerated hemivertebra was resected and the facet joints of the neighbouring vertebrae were joined to create a new functional motion segment and correct the kyphoscoliotic deformity. Transpedicular screws were inserted on the convex side in L2 and L3 and a tension band was applied. RESULTS: 16 years after the surgery, the patient was completely pain-free, motion of the lumbar spine was preserved and the physiological curvatures were maintained. CONCLUSION: To our knowledge a fusionless surgical solution for the treatment of a hemivertebra has never been described before. Although this is only a single case, the good result with a long follow-up suggests the technique is worthwhile considering when planning the treatment of a lumbar hemivertebra in very young children.

To fuse or not to fuse in lumbar degenerative spondylolisthesis: do baseline symptoms help provide the answer?

INTRODUCTION: Clinical symptoms in lumbar degenerative spondylolisthesis (LDS) vary from predominantly radiating pain to severe mechanical low back pain. We examined whether the outcome of surgery for LDS varied depending on the predominant baseline symptom and the treatment administered [decompression with fusion (D&F) or decompression alone (D)]. METHODS: 213 consecutive patients (69 ± 9 years; 155f, 58 m) participated. Inclusion criteria were LDS, maximum three affected levels, no previous surgery at the affected level, and D (N = 56) or D&F (N = 157) as the operative procedure. Pre-op and at 12 months' follow-up (FU), patients completed the multidimensional Core Outcome Measures Index (COMI) including 0-10 leg-pain (LP) and LBP scales. At 12 months' FU, patients rated global outcome which was then dichotomised into "good" and "poor". RESULTS: Pre-operatively, LBP and COMI scores were significantly worse (p < 0.05) in the D&F group than in the D group. The improvement in COMI at 12 months' FU was significantly greater for D&F than for D (p < 0.001) and was not influenced by the patient's declared "main problem" at baseline (back pain, leg pain, or neurological disturbances) (p > 0.05). There was a higher proportion (p = 0.01) of "good" outcomes at 12 months' FU in D&F (86%) than in D (70%). Multiple regression analysis, controlling for possible confounders, revealed treatment group to be the only significant predictor of outcome (adding fusion = better outcome). DISCUSSION: Our study indicated that LDS patients showed better patient-based outcome with instrumented fusion and decompression than with decompression alone, regardless of baseline symptoms. This may be due to the fact that the underlying slippage as the cause of the stenosis is better addressed with fusion.

The bothersomeness of patient self-rated "complications" reported 1 year after spine surgery.

PURPOSE: The last few decades have witnessed a paradigm shift in the assessment of outcome in spine surgery, with patient-centred questionnaires superseding traditional surgeon-based assessments. The assessment of complications after surgery and their impact on the patient has not enjoyed this same enlightened approach. This study sought to quantify the incidence and bothersomeness of patient-rated complications 1 year after surgery. METHODS: Patients with lumbar degenerative disorders, operated with the goal of pain relief between October 2006 and September 2010, completed a questionnaire 1 year postoperatively enquiring about complications arising as a consequence of their operation. They rated the bothersomeness of any such complications on a 5-point scale. Global outcome of surgery and satisfaction at the 12-month follow-up were also rated on 5-point Likert scales. The multidimensional Core Outcome Measures Index (COMI) was completed preoperatively and at the 12-month follow-up. RESULTS: Of 2,282 patients completing the questionnaire (92% completion rate), 687 (30.1%) reported complications, most commonly sensory disturbances (36% of those with complications) or ongoing/new pain (26%), followed by motor problems (8%), pain plus neurological disturbances (11%), and problems with wound healing (6%). The corresponding "bothersomeness" ratings for these were: 1% not at all, 23% slightly, 27% moderately, 31% very, and 18% extremely bothersome. The greater the bothersomeness, the worse the global outcome (Rho = 0.51, p < 0.0001), patient satisfaction (Rho = 0.44, p < 0.0001) and change in COMI score (Rho = 0.52, p < 0.0001). CONCLUSION: Most complications reported by the patient are perceived to be at least moderately bothersome and hence are not inconsequential. Complications and their severity should be assessed from both the patient's and the surgeon's perspectives--not least to better understand the reasons for poor outcome and dissatisfaction with treatment.

The outcome of decompression surgery for lumbar herniated disc is influenced by the level of concomitant preoperative low back pain.

Decompression surgery is a common and generally successful treatment for lumbar disc herniation (LDH). However, clinical practice raises some concern that the presence of concomitant low back pain (LBP) may have a negative influence on the overall outcome of treatment. This prospective study sought to examine on how the relative severity of LBP influences the outcome of decompression surgery for LDH. The SSE Spine Tango System was used to acquire the data from 308 patients. Inclusion criteria were LDH, first-time surgery, maximum 1 affected level, and decompression as the only procedure. Before and 12 months after surgery, patients completed the multidimensional Core Outcome Measures Index (COMI; includes 0-10 leg/buttock pain (LP) and LBP scales); at 12 months, global outcome was rated on a Likert scale and dichotomised into "good" and "poor" groups. In the "good" outcome group, mean baseline LP was 2.8 (SD 3.1) points higher than LBP; in the "poor" group, the corresponding value was 1.1 (SD 2.9) (p < 0.001 between groups). Significantly fewer patients with back pain as their "main problem" had a good outcome (69% good) when compared with those who reported leg/buttock pain (84% good) as the main problem (p = 0.04). In multivariate regression analyses (controlling for age, gender, co-morbidity), baseline LBP intensity was a significant predictor of the 12-month COMI score, and of the global outcome (each p < 0.05) (higher LBP, worse outcome). In conclusion, patients with more back pain showed significantly worse outcomes after decompression surgery for LDH. This finding fits with general clinical experience, but has rarely been quantified in the many predictor studies conducted to date. Consideration of the severity of concomitant LBP in LDH may assist in establishing realistic patient expectations before the surgery.

The quality of spine surgery from the patient's perspective: part 2. Minimal clinically important difference for improvement and deterioration as measured with the Core Outcome Measures Index.

The Core Outcome Measures Index (COMI) is a reliable and valid instrument for assessing multidimensional outcome in spine surgery. The minimal clinically important score-difference (MCID) for improvement (MCID(imp)) was determined in one of the original research studies validating the instrument, but has never been confirmed in routine clinical practice. Further, the MCID for deterioration (MCID(det)) has never been investigated; indeed, this needs very large sample sizes to obtain sufficient cases with worsening. This study examined the MCIDs of the COMI in routine clinical practice. All patients undergoing surgery in our Spine Center since February 2004 were asked to complete the COMI before and 12 months after surgery. The COMI has one question each on back (neck) pain intensity, leg/buttock (arm/shoulder) pain intensity, function, symptom-specific well-being, general quality of life, work disability, and social disability, scored as a 0-10 index. At follow-up, patients also rated the global effectiveness of surgery, on a 5-point Likert scale. This was used as the external criterion ("anchor") in receiver operating characteristics (ROC) analyses to derive cut-off scores for individual improvement and deterioration. Twelve-month follow-up questionnaires were returned by 3,056 (92%) patients. The group mean COMI score change for patients declaring that the "operation helped" was a reduction of 3.1 points; the corresponding value for those whom it "did not help" was a reduction of 0.5 points. The group MCID(imp) was hence 2.6 points reduction; the corresponding group MCID(det) was 1.2 points increase (0.5 minus -0.7). The area under the ROC curve was 0.88 for MCID(imp) and 0.89 for MCID(det) (both P < 0.0001), indicating that the COMI had good discriminative ability. The cut-offs for individual improvement and deterioration, respectively, were > or =2.2 points decrease (sensitivity 81%, specificity 83%) and > or =0.3 points increase (sensitivity 83%, specificity 88%). The MCID(imp) score of 2.2 points was similar to that reported in the original study (2-3 points, depending on external criterion used). The MCID(det) suggested that the COMI is less responsive to deterioration than to improvement, a phenomenon also reported for other spine outcome instruments. This needs further investigation in even larger patient groups. The MCIDs provide essential information for both the planning (sample size) and interpretation of the results (clinical relevance) of future clinical studies using the COMI.