Methodological aspects of a randomized within-patient concurrent controlled design for clinical trials in spine surgery.

INTRODUCTION: Randomized controlled trials are considered the highest level of evidence, but their feasibility in the surgical field is severely hampered by methodological and practical issues. Concurrent comparison between the experimental and control conditions within the same patient can be an effective strategy to mitigate some of these challenges and improve generalizability, mainly by the elimination of between-patient variability and reduction of the required sample size. This article aims (1) to describe the methodological aspects of a randomized within-patient controlled trial and (2) to quantify the added value of this design, based on a recently completed randomized within-patient controlled trial on bone grafts in instrumented lumbar posterolateral spinal fusion. METHODS: Boundary conditions for the application of the randomized within-patient controlled trial design were identified. Between-patient variability was quantified by the intraclass correlation coefficient and concordance in the primary fusion outcome. Sample size, study duration and costs were compared with a classic randomized controlled trial design. RESULTS: Boundary conditions include the concurrent application of the experimental and control conditions to identical but physically separated sites. Moreover, the outcome of interest should be local, uncorrelated and independently assessable. The spinal fusion outcomes within a patient were found to be more similar than between different patients (intraclass correlation coefficient 32% and concordance 64%), demonstrating a clear effect of patient-related factors. The randomized within-patient controlled trial design allowed a reduction of the sample size to one-third of a parallel-group randomized controlled trial, thereby halving the trial duration and costs. CONCLUSION: When suitable, the randomized within-patient controlled trial is an efficient design that provides a solution to some of the considerable challenges of a classic randomized controlled trial in (spine) surgery. This design holds specific promise for efficacy studies of non-active bone grafts in instrumented posterolateral fusion surgery.

Recurrence Rates Following Reconstruction Strategies After Wide Excision of Hidradenitis Suppurativa: A Systematic Review and Meta-analysis.

BACKGROUND: Wide excision (WE) is generally considered to be the most common treatment for recurrent hidradenitis suppurativa. When performed, excision is followed by decisions regarding best options for management of the surgical defect. Different reconstructive strategies (RSs) have been used, with varying rates of recurrence. OBJECTIVE: To provide an up-to-date systematic review of the complete literature for different RS after WE and their recurrence rates. METHODS: A systematic literature search of the complete available literature and a meta-analysis of proportions were performed on the included studies. RESULTS: Of a total of 1,813 retrieved articles, 79 were included in the analysis. Most were retrospective analyses, with only one randomized controlled trial (RCT) and 7 prospective analyses. The RS described were divided into primary closure (PC), secondary intention healing (SIH), skin graft (SG), and fasciocutaneous flaps (FCF). The average estimated recurrence for PC was 22.0% (95% confidence interval [CI], 8.0%-40.0%), for SIH 11.0% (95% CI, 5.0%-20.0%), for SG 2.0% (95% CI, 0.0%-5.0%), and for FCF 2.0% (95% CI, 1.0%-5.0%) (p < .001). Hidradenitis suppurativa below the umbilicus was significantly associated with overall recurrence (p = .006). Quality of evidence was poor, and the reporting of results was mostly heterogeneous. CONCLUSION: After WE, PC has the highest recurrence rates, whereas SG and FCF have the lowest rates. There is a need for more RCTs and guidelines, to be able to report uniformly on treatment outcomes.

Recurrence Rates Following Excision of Hidradenitis Suppurativa: A Systematic Review and Meta-analysis.

BACKGROUND: Surgery is considered to be the best treatment for recurrent hidradenitis suppurativa (HS). Varying recurrence rates have been reported in the literature. OBJECTIVE: To provide an up-to-date systematic review of the complete literature for different excision strategies and their recurrence rates in HS. METHODS: A systematic literature search of the complete available literature and a meta-analysis of proportions were performed on the included studies. RESULTS: Of a total of 1,593 retrieved articles, 125 were included in the analysis. Most of these studies were retrospective with 8 prospective analyses and one randomized controlled trial (RCT). The techniques described were divided into partial excision (PE) and wide excision (WE), described in 33 and 97 included studies, respectively. The average estimated recurrences were 26.0% (95% confidence interval [CI], 16.0%-37.0%) for PE and 5.0% (95% CI, 3.0%-9.0%) for WE (p < .01). Female sex (p = .016) and HS caudal of the umbilicus (p = .001) were significantly associated with the overall recurrence rate. Quality of evidence was poor, and the reporting of results was mostly heterogeneous. CONCLUSION: This systematic review showed higher recurrence rates when it was not intended to resect affected HS tissue with a radical margin. There is a need for more RCT's and uniformly reported treatment outcomes.

Down-titration and discontinuation strategies of tumour necrosis factor-blocking agents for rheumatoid arthritis in patients with low disease activity.

BACKGROUND: Anti-tumour necrosis factor (TNF) agents are effective in treating people with rheumatoid arthritis (RA), but are associated with (dose-dependent) adverse effects and high costs. To prevent overtreatment, several trials have assessed the effectiveness of down-titration compared with continuation of the standard dose. This is an update of a Cochrane Review published in 2014. OBJECTIVES: To evaluate the benefits and harms of down-titration (dose reduction, discontinuation, or disease activity-guided dose tapering) of anti-TNF agents on disease activity, functioning, costs, safety, and radiographic damage compared with usual care in people with RA and low disease activity. SEARCH METHODS: We searched MEDLINE, Embase, Web of Science and CENTRAL (29 March 2018) and four trial registries (11 April 2018) together with reference checking, citation searching, and contact with study authors to identify additional studies. We screened conference proceedings (American College of Rheumatology and European League Against Rheumatism 2005-2017). SELECTION CRITERIA: Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing down-titration (dose reduction, discontinuation, disease activity-guided dose tapering) of anti-TNF agents (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab) to usual care/no down-titration in people with RA and low disease activity. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology. MAIN RESULTS: One previously included trial was excluded retrospectively in this update because it was not an RCT/CCT. We included eight additional trials, for a total of 14 studies (13 RCTs and one CCT, 3315 participants in total) reporting anti-TNF down-titration. Six studies (1148 participants) reported anti-TNF dose reduction compared with anti-TNF continuation. Eight studies (2111 participants) reported anti-TNF discontinuation compared with anti-TNF continuation (three studies assessed both anti-TNF discontinuation and dose reduction), and three studies assessed disease activity-guided anti-TNF dose tapering (365 participants). These studies included data on all anti-TNF agents, but primarily adalimumab and etanercept. Thirteen studies were available in full text, one was available as abstract. We assessed the included studies generally at low to moderate risk of bias; our main concerns were bias due to open-label treatment and unblinded outcome assessment. Clinical heterogeneity between the trials was high. The included studies were performed at clinical centres around the world and included people with early as well as established RA, the majority of whom were female with mean ages between 47 and 60. Study durations ranged from 6 months to 3.5 years.We found that anti-TNF dose reduction leads to little or no difference in mean disease activity score (DAS28) after 26 to 52 weeks (high-certainty evidence, mean difference (MD) 0.06, 95% confidence interval (CI) -0.11 to 0.24, absolute risk difference (ARD) 1%) compared with continuation. Also, anti-TNF dose reduction does not result in an important deterioration in function after 26 to 52 weeks (Health Assessment Questionnaire Disability Index (HAQ-DI)) (high-certainty evidence, MD 0.09, 95% CI 0.00 to 0.19, ARD 3%). Next to this, anti-TNF dose reduction may slightly reduce the proportion of participants switched to another biologic (low-certainty evidence), but probably slightly increases the proportion of participants with minimal radiographic progression after 52 weeks (moderate-certainty evidence, risk ratio (RR) 1.22, 95% CI 0.76 to 1.95, ARD 2% higher). Anti-TNF dose reduction may cause little or no difference in serious adverse events, withdrawals due to adverse events and proportion of participants with persistent remission (low-certainty evidence).Results show that anti-TNF discontinuation probably slightly increases the mean disease activity score (DAS28) after 28 to 52 weeks (moderate-certainty evidence, MD 0.96, 95% CI 0.67 to 1.25, ARD 14%), and that the RR of persistent remission lies between 0.16 and 0.77 (low-certainty evidence). Anti-TNF discontinuation increases the proportion participants with minimal radiographic progression after 52 weeks (high-certainty evidence, RR 1.69, 95% CI 1.10 to 2.59, ARD 7%) and may lead to a slight deterioration in function (HAQ-DI) (low-certainty evidence). It is uncertain whether anti-TNF discontinuation influences the number of serious adverse events (due to very low-certainty evidence) and the number of withdrawals due to adverse events after 28 to 52 weeks probably increases slightly (moderate-certainty evidence, RR 1.46, 95% CI 0.75 to 2.84, ARD 1% higher).Anti-TNF disease activity-guided dose tapering may result in little or no difference in mean disease activity score (DAS28) after 72 to 78 weeks (low-certainty evidence). Furthermore, anti-TNF disease activity-guided dose tapering results in little or no difference in the proportion of participants with persistent remission after 18 months (high-certainty evidence, RR 0.89, 95% CI 0.75 to 1.06, ARD -9%) and may result in little or no difference in switching to another biologic (low-certainty evidence). Anti-TNF disease activity-guided dose tapering may slightly increase proportion of participants with minimal radiographic progression (low-certainty evidence) and probably leads to a slight deterioration of function after 18 months (moderate-certainty evidence, MD 0.2 higher, 0.02 lower to 0.42 higher, ARD 7% higher), It is uncertain whether anti-TNF disease activity-guided dose tapering influences the number of serious adverse events due to very low-certainty evidence. AUTHORS' CONCLUSIONS: We found that fixed-dose reduction of anti-TNF, after at least three to 12 months of low disease activity, is comparable to continuation of the standard dose regarding disease activity and function, and may be comparable with regards to the proportion of participants with persistent remission. Discontinuation (also without disease activity-guided adaptation) of anti-TNF is probably inferior to continuation of treatment with respect to disease activity, the proportion of participants with persistent remission, function, and minimal radiographic damage. Disease activity-guided dose tapering of anti-TNF is comparable to continuation of treatment with respect to the proportion of participants with persistent remission and may be comparable regarding disease activity.Caveats of this review are that available data are mainly limited to etanercept and adalimumab, the heterogeneity between studies, and the use of superiority instead of non-inferiority designs.Future research should focus on the anti-TNF agents infliximab and golimumab; assessment of disease activity, function, and radiographic outcomes after longer follow-up; and assessment of long-term safety, cost-effectiveness, and predictors for successful down-titration. Also, use of a validated flare criterion, non-inferiority designs, and disease activity-guided tapering instead of fixed-dose reduction or discontinuation would allow researchers to better interpret study findings and generalise to clinical practice.

Effectiveness of surgery for sciatica with disc herniation is not substantially affected by differences in surgical incidences among three countries: results from the Danish, Swedish and Norwegian spine registries.

PURPOSE: Yearly incidence of surgery for symptomatic lumbar disc herniation varies and is 29/100,000 in Sweden, 46/100,000 in Denmark and 58/100,000 in Norway. This variation was used to study whether differences in surgical incidence were associated with differences in preoperative patient characteristics as well as patient-reported outcomes. METHODS: Data from the national spine registers in Sweden, Denmark and Norway during 2011-2013 were pooled, and 9965 individuals, aged 18-65 years, of which 6468 had one-year follow-up data, were included in the study. Both absolute and case-mix-adjusted comparisons of the primary outcome Oswestry Disability Index (ODI) and the secondary outcomes EQ-5D-3L, and Numerical Rating Scale (NRS) for leg and back pain were performed. Case-mix adjustment was done for baseline age, sex, BMI, smoking, co-morbidity, duration of leg pain and preoperative value of the dependent variable. RESULTS: Mean improvement in the outcome variables exceeded previously described minimal clinical important change in all countries. Mean (95% CI) final scores of ODI were 18 (17-18), 19 (18-20) and 15 (15-16) in Sweden, Denmark and Norway, respectively. Corresponding results of EQ-5D-3L were 0.74 (0.73-0.75), 0.73 (0.72-0.75) and 0.75 (0.74-0.76). Results of NRS leg and back pain behaved similarly. Case-mix adjustment did not alter the findings substantially. CONCLUSION: We found no clear association between incidence of surgery for lumbar disc herniation and preoperative patient characteristics as well as outcome, and the differences between the countries were lower than the minimal clinical important difference in all outcomes. These slides can be retrieved under Electronic Supplementary Material.

Incidence and clinical relevance of cage subsidence in anterior cervical discectomy and fusion: a systematic review.

BACKGROUND: The placement of intervertebral cages in anterior cervical discectomy (ACDF) supposedly maintains foraminal height. The most commonly reported cage-related complication is subsidence, although it is unknown whether a correlation between subsidence and clinical outcome exists. AIM: To assess the incidence and relevance of subsidence. METHODS: Literature searches were performed in PubMed, MEDLINE, Embase, Web of Science, COCHRANE, and CENTRAL. The inclusion criteria were as follows: ≥ 20 patients, ADCF with cage, subsidence assessed, and primary data. Risk of bias was assessed using adjusted Cochrane checklists. RESULTS: Seventy-one studies, comprising 4784 patients, were included. Subsidence was generally defined as ≥ 3-mm loss of height comparing postoperative intervertebral heights with heights at last follow-up. Mean incidence of subsidence was 21% (range 0-83%). Of all patients, 46% of patients received polyether-ether-ketone (PEEK) cages, 31% received titanium cages, 18% received cage-screw-combinations, and 5% received polymethyl-methacrylate (PMMA) cages. Patients treated with cage-screw-combinations had significantly less subsidence than patients treated with PEEK, titanium, or PMMA cages (15.1% vs. 23.5% vs. 24.9% vs. 30.2%; p < 0.001). Thirteen studies assessed clinical outcome in relation to subsidence; the majority did not find a significant correlation. Only four studies correlated subsidence to cage size and/or height; no correlation was established. CONCLUSIONS: Subsidence in ACDF with cages occurs in 21% of patients. The risk for subsidence seems lower using PEEK or titanium cages or adding screws. Whether subsidence affects clinical outcome is not satisfactorily evaluated in the available literature. Future studies on this correlation are warranted in order to establish the additional value of the interposition of a cage in ACDF.

Magnetic resonance imaging in follow-up assessment of sciatica.

BACKGROUND: Magnetic resonance imaging (MRI) is frequently performed during follow-up in patients with known lumbar-disk herniation and persistent symptoms of sciatica. The association between findings on MRI and clinical outcome is controversial. METHODS: We studied 283 patients in a randomized trial comparing surgery and prolonged conservative care for sciatica and lumbar-disk herniation. Patients underwent MRI at baseline and after 1 year. We used a 4-point scale to assess disk herniation on MRI, ranging from 1 for "definitely present" to 4 for "definitely absent." A favorable clinical outcome was defined as complete or nearly complete disappearance of symptoms at 1 year. We compared proportions of patients with a favorable outcome among those with a definite absence of disk herniation and those with a definite, probable, or possible presence of disk herniation at 1 year. The area under the receiver-operating-characteristic (ROC) curve was used to assess the prognostic accuracy of the 4-point scores regarding a favorable or unfavorable outcome, with 1 indicating perfect discriminatory value and 0.5 or less indicating no discriminatory value. RESULTS: At 1 year, 84% of the patients reported having a favorable outcome. Disk herniation was visible in 35% with a favorable outcome and in 33% with an unfavorable outcome (P=0.70). A favorable outcome was reported in 85% of patients with disk herniation and 83% without disk herniation (P=0.70). MRI assessment of disk herniation did not distinguish between patients with a favorable outcome and those with an unfavorable outcome (area under ROC curve, 0.48). CONCLUSIONS: MRI performed at 1-year follow-up in patients who had been treated for sciatica and lumbar-disk herniation did not distinguish between those with a favorable outcome and those with an unfavorable outcome. (Funded by the Netherlands Organization for Health Research and Development and the Hoelen Foundation; Controlled Clinical Trials number, ISRCTN26872154.).

Effectiveness of posterior decompression techniques compared with conventional laminectomy for lumbar stenosis.

BACKGROUND: The gold standard treatment for symptomatic lumbar stenosis refractory to conservative management is a facet-preserving laminectomy. New techniques of posterior decompression have been developed to preserve spinal integrity and to minimise tissue damage by limiting bony decompression and avoiding removal of the midline structures (i.e. spinous process, vertebral arch and interspinous and supraspinous ligaments). OBJECTIVES: To compare the effectiveness of techniques of posterior decompression that limit the extent of bony decompression or avoid removal of posterior midline structures of the lumbar spine versus conventional facet-preserving laminectomy for the treatment of patients with degenerative lumbar stenosis. SEARCH METHODS: An experienced librarian conducted a comprehensive electronic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science, and the clinical trials registries ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) for relevant literature up to June 2014. SELECTION CRITERIA: We included prospective controlled studies comparing conventional facet-preserving laminectomy versus a posterior decompressive technique that avoids removal of posterior midline structures or a technique involving only partial resection of the vertebral arch. We excluded studies describing techniques of decompression by means of interspinous process devices or concomitant (instrumented) fusion procedures. Participants included individuals with symptomatic degenerative lumbar stenosis only. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed risk of bias using the Cochrane Back Review Group criteria for randomised controlled trials (RCTs) and the Newcastle-Ottawa Scale for non-randomised studies. We extracted data regarding demographics, intervention details and outcome measures. MAIN RESULTS: A total of four high-quality RCTs and six low-quality RCTs met the search criteria of this review. These studies included a total of 733 participants. Investigators compared three different posterior decompression techniques versus conventional laminectomy. Three studies (173 participants) compared unilateral laminotomy for bilateral decompression versus conventional laminectomy. Four studies (382 participants) compared bilateral laminotomy versus conventional laminectomy (one study included three treatment groups and compared unilateral and bilateral laminotomy vs conventional laminectomy). Finally, four studies (218 participants) compared a split-spinous process laminotomy versus conventional laminectomy.Evidence of low or very low quality suggests that different techniques of posterior decompression and conventional laminectomy have similar effects on functional disability and leg pain. Only perceived recovery at final follow-up was better in people who underwent bilateral laminotomy compared with conventional laminectomy (two RCTs, 223 participants, odds ratio 5.69, 95% confidence interval (CI) 2.55 to 12.71).Among the secondary outcome measures, unilateral laminotomy for bilateral decompression and bilateral laminotomy resulted in numerically fewer cases of iatrogenic instability, although in both cases, the incidence of instability was low (three RCTs, 166 participants, odds ratio 0.28, 95% CI 0.07 to 1.15; three RCTs, 294 participants, odds ratio 0.10, 95% CI 0.02 to 0.55, respectively). The difference in severity of postoperative low back pain following bilateral laminotomy (two RCTs, 223 participants, mean difference -0.51, 95% CI -0.80 to -0.23) and split-spinous process laminotomy compared with conventional laminectomy (two RCTs, 97 participants, mean difference -1.07, 95% CI -2.15 to -0.00) was significantly less, but was too small to be clinically important. A quantitative comparison between unilateral laminotomy and conventional laminectomy was not possible because of different reporting of outcome measures. We found no evidence to show that the incidence of complications, length of the procedure, length of hospital stay and postoperative walking distance differed between techniques of posterior decompression. AUTHORS' CONCLUSIONS: The evidence provided by this systematic review for the effects of unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy compared with conventional laminectomy on functional disability, perceived recovery and leg pain is of low or very low quality. Therefore, further research is necessary to establish whether these techniques provide a safe and effective alternative for conventional laminectomy. Proposed advantages of these techniques regarding the incidence of iatrogenic instability and postoperative back pain are plausible, but definitive conclusions are limited by poor methodology and poor reporting of outcome measures among included studies. Future research is necessary to establish the incidence of iatrogenic instability using standardised definitions of radiological and clinical instability at comparable follow-up intervals. Long-term results with these techniques are currently lacking.

Mobile bearing vs fixed bearing prostheses for posterior cruciate retaining total knee arthroplasty for postoperative functional status in patients with osteoarthritis and rheumatoid arthritis.

BACKGROUND: It is unclear whether there are differences in benefits and harms between mobile and fixed prostheses for total knee arthroplasty (TKA). The previous Cochrane review published in 2004 included two articles. Many more trials have been performed since then; therefore an update is needed. OBJECTIVES: To assess the benefits and harms of mobile bearing compared with fixed bearing cruciate retaining total knee arthroplasty for functional and clinical outcomes in patients with osteoarthritis (OA) or rheumatoid arthritis (RA). SEARCH METHODS: We searched The Cochrane Library, PubMed, EMBASE, CINAHL and Web of Science up to 27 February 2014, and the trial registers ClinicalTrials.gov, Multiregister, Current Controlled Trials and the World Health Organization (WHO) International Clinical Trials Registry Platform for data from unpublished trials, up to 11 February 2014. We also screened the reference lists of selected articles. SELECTION CRITERIA: We selected randomised controlled trials comparing mobile bearing with fixed bearing prostheses in cruciate retaining TKA among patients with osteoarthritis or rheumatoid arthritis, using functional or clinical outcome measures and follow-up of at least six months. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as expected by The Cochrane Collaboration. MAIN RESULTS: We found 19 studies with 1641 participants (1616 with OA (98.5%) and 25 with RA (1.5%)) and 2247 knees. Seventeen new studies were included in this update.Quality of the evidence ranged from moderate (knee pain) to low (other outcomes). Most studies had unclear risk of bias for allocation concealment, blinding of participants and personnel, blinding of outcome assessment and selective reporting, and high risk of bias for incomplete outcome data and other bias. Knee painWe calculated the standardised mean difference (SMD) for pain, using the Knee Society Score (KSS) and visual analogue scale (VAS) in 11 studies (58%) and 1531 knees (68%). No statistically significant differences between groups were reported (SMD 0.09, 95% confidence interval (CI) -0.03 to 0.22, P value 0.15). This represents an absolute risk difference of 2.4% points higher (95% CI 0.8% lower to 5.9% higher) on the KSS pain scale and a relative percent change of 0.22% (95% CI 0.07% lower to 0.53% higher). The results were homogeneous. Clinical and functional scores The KSS clinical score did not differ statistically significantly between groups (14 studies (74%) and 1845 knees (82%)) with a mean difference (MD) of -1.06 points (95% CI -2.87 to 0.74, P value 0.25) and heterogeneous results. KSS function was reported in 14 studies (74%) with 1845 knees (82%) as an MD of -0.10 point (95% CI -1.93 to 1.73, P value 0.91) and homogeneous results. In two studies (11%), the KSS total score was favourable for mobile bearing (159 vs 132 for fixed bearing), with MD of -26.52 points (95% CI -45.03 to -8.01, P value 0.005), but with a wide 95% confidence interval indicating uncertainty about the estimate.Other reported scoring systems did not show statistically significant differences: Hospital for Special Surgery (HSS) score (seven studies (37%) in 1021 knees (45%)) with an MD of -1.36 (95% CI -4.18 to 1.46, P value 0.35); Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score (two studies (11%), 167 knees (7%)) with an MD of -4.46 (95% CI -16.26 to 7.34, P value 0.46); and Oxford total (five studies (26%), 647 knees (29%) with an MD of -0.25 (95% CI -1.41 to 0.91, P value 0.67). Health-related quality of lifeThree studies (16%) with 498 knees (22%) reported on health-related quality of life, and no statistically significant differences were noted between the mobile bearing and fixed bearing groups. The Short Form (SF)-12 Physical Component Summary had an MD of -1.96 (95% CI -4.55 to 0.63, P value 0.14) and heterogeneous results. Revision surgeryTwenty seven revisions (1.3%) were performed in 17 studies (89%) with 2065 knees (92%). In all, 13 knees were revised in the fixed bearing group and 14 knees in the mobile bearing group. No statistically significant differences were found (risk difference 0.00, 95% CI -0.01 to 0.01, P value 0.58), and homogeneous results were reported. MortalityIn seven out of 19 studies, 13 participants (37%) died. Two of these participants had undergone bilateral surgery, and for seven participants, it was unclear which prosthesis they had received; therefore they were excluded from the analyses. Thus our analysis included four out of 191 participants (2.1%) who had died: one in the fixed bearing group and three in the mobile bearing group. No statistically significant differences were found. The risk difference was -0.02 (95% CI -0.06 to 0.03, P value 0.49) and results were homogeneous. Reoperation ratesThirty reoperations were performed in 17 studies (89%) with 2065 knees (92%): 18 knees in the fixed bearing group (of the 1031 knees) and 12 knees in the mobile group (of the 1034 knees). No statistically significant differences were found. The risk difference was -0.01 (95% CI -0.01 to 0.01, P value 0.99) with homogeneous results. Other serious adverse eventsSixteen studies (84%) reported nine other serious adverse events in 1735 knees (77%): four in the fixed bearing group (of the 862 knees) and five in the mobile bearing group (of the 873 knees). No statistically significant differences were found (risk difference 0.00, 95% CI -0.01 to 0.01, P value 0.88), and results were homogeneous. AUTHORS' CONCLUSIONS: Moderate- to low-quality evidence suggests that mobile bearing prostheses may have similar effects on knee pain, clinical and functional scores, health-related quality of life, revision surgery, mortality, reoperation rate and other serious adverse events compared with fixed bearing prostheses in posterior cruciate retaining TKA. Therefore we cannot draw firm conclusions. Most (98.5%) participants had OA, so the findings primarily reflect results reported in participants with OA. Future studies should report in greater detail outcomes such as those presented in this systematic review, with sufficient follow-up time to allow gathering of high-quality evidence and to inform clinical practice. Large registry-based studies may have added value, but they are subject to treatment-by-indication bias. Therefore, this systematic review of RCTs can be viewed as the best available evidence.

Effectiveness of posterior decompression techniques compared with conventional laminectomy for lumbar stenosis.

PURPOSE: To compare the effectiveness of techniques of posterior decompression that limit the extent of bony decompression or to avoid removal of posterior midline structures of the lumbar spine versus conventional facet-preserving laminectomy for the treatment of patients with degenerative lumbar stenosis. METHODS: A comprehensive electronic search of the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Web of Science, and the clinical trials registries ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform was conducted for relevant literature up to June 2014. RESULTS: A total of four high-quality RCTs and six low-quality RCTs met the search criteria of this review. These studies included a total of 733 participants. Three different techniques that avoid removal of posterior midline structures are compared to conventional laminectomy; unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy. Evidence of low or very low quality suggests that different techniques of posterior decompression and conventional laminectomy have similar effects on functional disability and leg pain. Only perceived recovery at final follow-up was better in patients that underwent bilateral laminotomy compared with conventional laminectomy. Unilateral laminotomy for bilateral decompression and bilateral laminotomy resulted in numerically fewer cases of iatrogenic instability, although in both cases, the incidence of instability was low. The difference in severity of postoperative low back pain following bilateral laminotomy and split-spinous process laminotomy was significantly less, but was too small to be clinically important. We found no evidence to show that the incidence of complications, length of the procedure, length of hospital stay and postoperative walking distance differed between techniques of posterior decompression. CONCLUSION: The evidence provided by this systematic review for the effects of unilateral laminotomy for bilateral decompression, bilateral laminotomy and split-spinous process laminotomy compared with conventional laminectomy on functional disability, perceived recovery and leg pain is of low or very low quality. Therefore, further research is necessary to establish whether these techniques provide a safe and effective alternative for conventional laminectomy. Proposed advantages of these techniques regarding the incidence of iatrogenic instability and postoperative back pain are plausible, but definitive conclusions are limited by poor methodology and poor reporting of outcome measures among included studies.

IPD without bony decompression versus conventional surgical decompression for lumbar spinal stenosis: 2-year results of a double-blind randomized controlled trial.

PURPOSE: Interspinous process devices (IPDs) are implanted to treat patients with intermittent neurogenic claudication (INC) based on lumbar spinal stenosis. It is hypothesized that patients with lumbar spinal stenosis treated with IPD have a faster short-term recovery, an equal outcome after 2 years and less back pain compared with bony decompression. METHODS: A randomized design with variable block sizes was used, with allocations stratified according to center. Allocations were stored in prepared opaque, coded and sealed envelopes, and patients and research nurses were blind throughout the follow-up. Five neurosurgical centers (including one academic and four secondary level care centers) included participants. 211 participants were referred to the Leiden-The Hague Spine Prognostic Study Group. 159 participants with INC based on lumbar spinal stenosis at one or two levels with an indication for surgery were randomized into two groups. Patients and research nurses were blinded for the allocated treatment throughout the study period. 80 participants received an IPD and 79 participants underwent spinal bony decompression. The primary outcome at long-term (2-year) follow-up was the score for the Zurich Claudication Questionnaire. Repeated measurement analyses were applied to compare outcomes over time. RESULTS: At two years, the success rate according to the Zurich Claudication Questionnaire for the IPD group [69 % (95 % CI 57-78 %)] did not show a significant difference compared with standard bony decompression [60 % (95 % CI 48-71 %) p value 0.2]. Reoperations, because of absence of recovery, were indicated and performed in 23 cases (33 %) of the IPD group versus 6 (8 %) patients of the bony decompression group (p < 0.01). Furthermore, long-term VAS back pain was significantly higher [36 mm on a 100 mm scale (95 % CI 24-48)] in the IPD group compared to the bony decompression group [28 mm (95 % CI 23-34) p value 0.04]. CONCLUSIONS: This double-blinded study could not confirm the advantage of IPD without bony decompression over conventional 'simple' decompression, two years after surgery. Moreover, in the IPD treatment arm, the reoperation rate was higher and back pain was even slightly more intense compared to the decompression treatment arm.

Interspinous process device versus standard conventional surgical decompression for lumbar spinal stenosis: randomised controlled trial.

STUDY QUESTION: Is interspinous process device implantation more effective in the short term (eight weeks) than conventional surgical decompression for patients with intermittent neurogenic claudication due to lumbar spinal stenosis? SUMMARY ANSWER: The use of interspinous implants did not result in a better outcome than conventional decompression, but the reoperation rate was significantly higher. WHAT IS KNOWN AND WHAT THIS PAPER ADDS: Bony decompression and treatment with interspinous process devices are superior to conservative and non-surgical treatment for intermittent neurogenic claudication due to lumbar spinal stenosis. Interspinous implants surgery is not superior to bony decompression, and the reoperation rate is significantly higher.

Similar outcome after retention or sacrifice of the posterior cruciate ligament in total knee arthroplasty.

BACKGROUND AND PURPOSE: To retain or to sacrifice the posterior cruciate ligament (PCL) in total knee arthroplasty (TKA) remains a matter of discussion. In this systematic review, we wanted to find differences in functional and clinical outcome between the 2 methods. METHODS: We conducted a systematic review and meta-analysis including all randomized controlled trials (RCTs) and quasi-RCTs that have compared PCL retention with PCL sacrifice in TKA with a minimum of 1-year follow-up. Primary outcome was range of motion. Secondary outcomes were knee pain and clinical scoring systems that were preferably validated. Quality of evidence was graded using the GRADE approach. All outcomes available for data pooling were used for meta-analysis. RESULTS: 20 studies involving 1,877 patients and 2,347 knees were included. In meta-analysis, the postoperative flexion angle had a mean difference of 2 degrees (95% CI: 0.23-4.0; p = 0.03) and the KSS functional score was 2.4 points higher in favor of PCL sacrifice (95% CI: 0.41-4.3; p = 0.02). There were no statistically significant differences regarding other measured clinical outcomes such as WOMAC, KSS pain, clinical and overall score, HSS score, SF-12, radiolucencies, femoro-tibial angle, and tibial slope. The quality of the studies varied considerably. Risk of bias in most studies was unclear; 5 were judged to have a low risk of bias and 5 to have a high risk of bias. INTERPRETATION: We found no clinically relevant differences between retention and sacrifice of the PCL in TKA, in terms of functional and clinical outcomes. The quality of the studies ranged from moderate to low. Based on the current evidence, no recommendation can be made as to whether to retain or to sacrifice the PCL.

Evidence and practice in spine registries.

BACKGROUND AND PURPOSE: We performed a systematic review and a survey in order to (1) evaluate the evidence for the impact of spine registries on the quality of spine care, and with that, on patient-related outcomes, and (2) evaluate the methodology used to organize, analyze, and report the "quality of spine care" from spine registries. METHODS: To study the impact, the literature on all spinal disorders was searched. To study methodology, the search was restricted to degenerative spinal disorders. The risk of bias in the studies included was assessed with the Newcastle-Ottawa scale. Additionally, a survey among registry representatives was performed to acquire information about the methodology and practice of existing registries. RESULTS: 4,273 unique references up to May 2014 were identified, and 1,210 were eligible for screening and assessment. No studies on impact were identified, but 34 studies were identified to study the methodology. Half of these studies (17 of the 34) were judged to have a high risk of bias. The survey identified 25 spine registries, representing 14 countries. The organization of these registries, methods used, analytical approaches, and dissemination of results are presented. INTERPRETATION: We found a lack of evidence that registries have had an impact on the quality of spine care, regardless of whether intervention was non-surgical and/or surgical. To improve the quality of evidence published with registry data, we present several recommendations. Application of these recommendations could lead to registries showing trends, monitoring the quality of spine care given, and ultimately improving the value of the care given to patients with degenerative spinal disorders.

A proposed set of metrics for standardized outcome reporting in the management of low back pain.

BACKGROUND AND PURPOSE: Outcome measurement has been shown to improve performance in several fields of healthcare. This understanding has driven a growing interest in value-based healthcare, where value is defined as outcomes achieved per money spent. While low back pain (LBP) constitutes an enormous burden of disease, no universal set of metrics has yet been accepted to measure and compare outcomes. Here, we aim to define such a set. PATIENTS AND METHODS: An international group of 22 specialists in several disciplines of spine care was assembled to review literature and select LBP outcome metrics through a 6-round modified Delphi process. The scope of the outcome set was degenerative lumbar conditions. RESULTS: Patient-reported metrics include numerical pain scales, lumbar-related function using the Oswestry disability index, health-related quality of life using the EQ-5D-3L questionnaire, and questions assessing work status and analgesic use. Specific common and serious complications are included. Recommended follow-up intervals include 6, 12, and 24 months after initiating treatment, with optional follow-up at 3 months and 5 years. Metrics for risk stratification are selected based on pre-existing tools. INTERPRETATION: The outcome measures recommended here are structured around specific etiologies of LBP, span a patient's entire cycle of care, and allow for risk adjustment. Thus, when implemented, this set can be expected to facilitate meaningful comparisons and ultimately provide a continuous feedback loop, enabling ongoing improvements in quality of care. Much work lies ahead in implementation, revision, and validation of this set, but it is an essential first step toward establishing a community of LBP providers focused on maximizing the value of the care we deliver.

Down-titration and discontinuation strategies of tumor necrosis factor-blocking agents for rheumatoid arthritis in patients with low disease activity.

BACKGROUND: Anti-tumor necrosis factor (TNF) agents are effective in treating patients with rheumatoid arthritis (RA), but they are associated with (dose-dependent) adverse effects and high costs. To prevent overtreatment, several trials have assessed the effectiveness of down-titration compared with continuation of the standard dose. OBJECTIVES: To evaluate the benefits and harms of down-titration (dose reduction, discontinuation or disease activity guided dose tapering) of anti-TNF agents (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab) on disease activity, functioning, costs, safety and radiographic damage compared with usual care in patients with RA and low disease activity. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Issue 8, 2013; Ovid MEDLINE (1946 to 8 September 2013); EMBASE (1947 to 8 September 2013); Science Citation Index (Web of Science); and conference proceedings of the American College of Rheumatology (2005 to 2012) and European League against Rheumatism (2005 to 2013). We contacted authors of the seven included studies to ask for additional information on their study; five responded. SELECTION CRITERIA: Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing down-titration (dose reduction, discontinuation, disease activity-guided dose tapering) of anti-TNF agents (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab) to usual care/no down-titration in patients with RA and a low disease activity state. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risk of bias and extracted data. MAIN RESULTS: Six RCTs and one CCT (total 1203 participants), reporting anti-TNF down-titration, were included. Three studies (559 participants) reported anti-TNF dose reduction compared with anti-TNF continuation. Five studies (732 participants) reported anti-TNF discontinuation compared with anti-TNF continuation (two studies assessed both anti-TNF discontinuation and dose reduction), and one study assessed disease activity-guided anti-TNF dose tapering (137 participants). These studies include only adalimumab and etanercept; controlled data on other anti-TNF agents are absent. Two studies were available in full text; one was assessed as having low risk of bias and the other high risk. Five studies were available only as one or more abstracts. Because data provided in these abstracts were limited, risk of bias was unclear. Clinical heterogeneity between the trials was high.Dose reduction of anti-TNF (etanercept data only) showed no statistically significant or clinical relevant difference in disease activity score in 28 joints (DAS28) (mean difference (MD) 0.10, 95% confidence interval (CI) -0.11 to 0.31) (scale 0.9 to 8; higher score indicates worse disease activity). The proportion of participants who maintained low disease activity was slightly lower among participants given reduced doses of the anti-TNF agent (risk ratio (RR) 0.87, 95% CI 0.78 to 0.98, absolute risk difference (ARD) 9%). Radiographic outcome was slightly worse, but this was not clinically meaningful, compared with continuation of anti-TNF (MD 0.11, 95% CI 0.08 to 0.14) (scale 0 to 448; higher score indicates greater joint damage). Function was not statistically different between anti-TNF dose reduction and continuation (MD 0.10, 95% CI 0.00 to 0.20) (scale 0 to 3; higher score indicates worse functioning). Reinstalment of anti-TNF after failure of dose reduction showed a 5% risk of persistent flare. Data on numbers of serious adverse events (SAEs) (RR 0.58, 95% CI 0.23 to 1.45, ARD -2%) and withdrawals due to adverse events (AEs) (RR 0.57, 95% CI 0.17 to 1,92, ARD -1%) were inconclusive. Most outcomes were based on moderate quality evidence.Participants who discontinued anti-TNF (adalimumab and etanercept data) had higher mean DAS28 (DAS28-erythrocyte sedimentation rate (ESR): MD 1.10, 95% CI 0.86 to 1.34) and DAS28-C-reactive protein (CRP): MD 0.57 95% CI -0.09 to 1.23) and were less likely to maintain a low disease activity state (RR 0.43, 95% CI 0.27 to 0.68, ARD 40%). Also, radiographic and functional outcomes are worse after anti-TNF discontinuation (MD 0.66, 95% CI 0.63 to 0.69, and MD 0.30, 95% CI 0.19 to 0.41, respectively). Data on numbers of SAEs (RR 1.26, 95% CI 0.61 to 2.63, ARD 2%) and withdrawals due to AEs (RR 0.72, 95% CI 0.23 to 2.24, ARD -1%) were inconclusive. Most outcomes were based on moderate quality evidence.The one study comparing disease activity-guided anti-TNF dose tapering (adalimumab and etanercept data) reported no statistically significant differences in functional outcomes (MD 0.20, 95% CI -0.02 to 0.42). Significantly higher mean disease activity was found among participants with tapered anti-TNF at study end (MD 0.50, 95% CI 0.11 to 0.89). No full text of this trial was available for this review. No other major outcomes were reported. All outcomes were based on low quality evidence. AUTHORS' CONCLUSIONS: We can conclude, mostly based on moderate quality evidence, that non-disease activity guided dose reduction of etanercept 50 mg weekly to 25 mg weekly, after at least three to 12 months of low disease activity, seems as effective as continuing the standard dose with respect to disease activity and functional outcomes, although dose reduction significantly induces minimal and not clinically meaningful differences in radiological progression. Discontinuation (also without disease activity-guided adaptation) of adalimumab and etanercept is inferior to continuation of treatment with respect to disease activity and radiological outcomes and function. Disease activity-guided dose tapering of adalimumab and etanercept seems slightly inferior to continuation of treatment with respect to disease activity, with no difference in function. However the only study investigating this comparison included lower than projected numbers of participants.Caveats of this review are that available data are limited. Also, the heterogeneity between studies and the suboptimal design choices (including absence of disease activity-guided dose reduction and discontinuation and use of superiority designs) limit definitive conclusions. None of the included studies assessed long-term safety and costs, although these factors are specific reasons why clinicians consider lowering the dose or stopping the administration of anti-TNF agents.Future research should include other anti-TNF agents; assessment of disease activity, function and radiographic outcomes after longer follow-up; and assessment of long-term safety, cost-effectiveness and predictors for successful down-titration. Also use of a validated flare criterion, non-inferiority designs and disease activity-guided instead of fixed-dose tapering or stopping would allow researchers to better interpret study findings and generalise the information to clinical practice.

Rationale and design of the INNOVATE Trial: an international cooperative study on surgical versus conservative treatment for odontoid fractures in the elderly.

BACKGROUND: Fractures of the odontoid process of the axis are the most common fractures of the geriatric cervical spine. As the population ages, their incidence is expected to increase progressively, as is the number of very old patients (>80 years) with an odontoid fracture. No consensus exists on the optimal treatment (surgical or conservative) and the most relevant outcome parameter (osseous union, fracture stability or clinical outcome). The aim of the INNOVATE (INterNational study on Odontoid frActure Treatment in the Elderly) Trial is to prospectively assess fracture healing and clinical outcome after surgical and conservative treatment for odontoid fractures in the elderly patient, with a specific focus on the very old patient. METHODS/DESIGN: The trial is an observational study in which eleven centres in five European countries are involved. All patients admitted to one of these centres who meet the selection criteria (≥55 years, acute (

CASINO: surgical or nonsurgical treatment for cervical radiculopathy, a randomised controlled trial.

BACKGROUND: Cervical radicular syndrome (CRS) due to a herniated disc can be safely treated by surgical decompression of the spinal root. In the vast majority of cases this relieves pain in the arm and restores function. However, conservative treatment also has a high chance on relieving symptoms. The objective of the present study is to evaluate the (cost-) effectiveness of surgery versus prolonged conservative care during one year of follow-up, and to evaluate the timing of surgery. Predisposing factors in favour of one of the two treatments will be evaluated. METHODS/DESIGN: Patients with disabling radicular arm pain, suffering for at least 2 months, and an MRI-proven herniated cervical disc will be randomised to receive either surgery or prolonged conservative care with surgery if needed. The surgical intervention will be an anterior discectomy or a posterior foraminotomy that is carried out according to usual care. Surgery will take place within 2-4 weeks after randomisation. Conservative care starts immediately after randomisation. The primary outcome measure is the VAS for pain or tingling sensations in the arm one year after randomisation. In addition, timing of surgery will be studied by correlating the primary outcome to the duration of symptoms. Secondary outcome measures encompass quality of life, costs and perceived recovery. Predefined prognostic factors will be evaluated. The total follow-up period will cover two years. A sample size of 400 patients is needed. Statistical analysis will be performed using a linear mixed model which will be based on the 'intention to treat' principle. In addition, a new CRS questionnaire for patients will be developed, the Leiden Cervical Radicular Syndrome Functioning (LCRSF) scale. DISCUSSION: The outcome will contribute to better decision making for the treatment of cervical radicular syndrome. TRIAL REGISTRATION: NTR3504.

Management of lumbar spinal stenosis: a survey among Dutch spine surgeons.

BACKGROUND: Various surgical and non-surgical treatments for lumbar spinal stenosis (LSS) are widely adopted in clinical practice, but high quality randomised controlled trials to support these are often lacking, especially in terms of their relative benefit and risk compared with other treatment options. Therefore, an evaluation of agreement among clinicians regarding the indications and the choice for particular treatments seems appropriate. METHODS: One hundred and six Dutch neurosurgeons and orthopaedic spine surgeons completed a questionnaire, which evaluated treatment options for LSS and expectations regarding the effectiveness of surgical and non-surgical treatments. RESULTS: Responders accounted for 6,971 decompression operations and 831 spinal fusion procedures for LSS annually. Typical neurogenic claudication, severe pain/disability, and a pronounced constriction of the spinal canal were considered the most important indications for surgical treatment by the majority of responders. Non-surgical treatment was generally regarded as ineffective and believed to be less effective than surgical treatment. Interlaminar decompression was the preferred technique by 68% of neurosurgeons and 52% orthopaedic surgeons for the treatment of LSS. Concomitant fusion was applied in 12% of all surgery for LSS. Most surgeons considered spondylolisthesis as an indication and spinal instability as a definite indication for additional fusion. CONCLUSIONS: The current survey demonstrates a wide variety of preferred treatments of symptomatic LSS by Dutch spine surgeons. To minimise variety, national and international protocols based on high-quality randomised controlled trials and systematic reviews are necessary to give surgeons more tools to support everyday decision-making.

Retention versus sacrifice of the posterior cruciate ligament in total knee arthroplasty for treating osteoarthritis.

BACKGROUND: The functional and clinical basis on which to choose whether or not to retain the posterior cruciate ligament during total knee arthroplasty surgery remained unclear after a Cochrane systematic review and meta-analysis in 2005, which contained eight clinical trials. Several new trials have been conducted since then. Hence, an update of the review was performed. OBJECTIVES: Our aim was to assess the benefits and harms of retention compared to sacrifice of the posterior cruciate ligament in total knee arthroplasty in patients with osteoarthritis of the knee. SEARCH METHODS: An extensive search was conducted in CENTRAL, MEDLINE (PubMed), EMBASE, Web of Science, CINAHL, Academic Search Premier, Current Contents Connect and Science Direct. All databases were searched, without any limitations, up to 6 December 2012. References of the articles were checked and citation tracking was performed. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials comparing retention with sacrifice of the posterior cruciate ligament in primary total knee arthroplasty in patients with osteoarthritis of the knee. DATA COLLECTION AND ANALYSIS: Data were collected with a pre-developed form. Risk of bias was assessed independently by two authors (WV, LB). The level of evidence was graded using the GRADE approach. Meta-analysis was performed by pooling the results of the selected studies, when possible. Subgroup analyses were performed for posterior cruciate ligament retention versus sacrifice using the same total knee arthroplasty design, and for studies using a posterior cruciate ligament retaining or posterior stabilised design, and when sufficient studies were available subgroup analyses were performed for the same brand. MAIN RESULTS: Seventeen randomised controlled trials (with 1810 patients and 2206 knees) were found, described in 18 articles. Ten of these were new studies compared to the previous Cochrane Review. One study from the original Cochrane review was excluded. Most new studies compared a posterior cruciate ligament retaining design with a posterior stabilised design, in which the posterior cruciate ligament is sacrificed (a posterior stabilised design has an insert with a central post which can engage on a femoral cam during flexion).The quality of evidence (graded with the GRADE approach) and the risk of bias were highly variable, ranging from moderate to low quality evidence and with unclear or low risk of bias for most domains, respectively.The performance outcome 'range of motion' was 2.4 ° higher in favour of posterior cruciate ligament sacrifice (118.3 ° versus 115.9 °; 95% confidence interval (CI) of the difference 0.13 to 4.67; P = 0.04), however the results were heterogeneous. On the item 'knee pain' as experienced by patients, meta-analysis could be performed on the Knee Society knee pain score; this score was 48.3 in both groups, yielding no difference between the groups. Implant survival rate could not be meta-analysed adequately since randomised controlled trials lack the longer term follow-up in order to evaluate implant survival. A total of four revisions in the cruciate-retention and four revisions in the cruciate-sacrifice group were found. The well-validated Western Ontario and McMaster Universities osteoarthritis index (WOMAC) total score was not statistically significantly different between the groups (16.6 points for cruciate-retention versus 15.0 points for cruciate-sacrifice). One study reported a patient satisfaction grade (7.7 points for cruciate-retention versus 7.9 points for cruciate-sacrifice on a scale from 0 to 10, 10 being completely satisfied) which did not differ statistically significantly. Complications were distributed equally between both groups. Only one study reported several re-operations other than revision surgery; that is patella luxations, surgical manipulation because of impaired flexion.The mean functional Knee Society Score was 2.3 points higher (81.2 versus 79.0 points; 95% CI of the difference 0.37 to 4.26; P = 0.02) in the posterior cruciate ligament sacrificing group. Results from the outcome Knee Society functional score were homogeneous. All other outcome measures (extension angle, knee pain, adverse effects, clinical questionnaire scores, Knee Society clinical scores, radiological rollback, radiolucencies, femorotibial angle and tibial slope) showed no statistically significant differences between the groups. In the subgroup analyses that allowed pooling of the results of the different studies, no homogeneous statistically significant differences were identified. AUTHORS' CONCLUSIONS: The methodological quality and the quality of reporting of the studies were highly variable. With respect to range of motion, pain, clinical, and radiological outcomes, no clinically relevant differences were found between total knee arthroplasty with retention or sacrifice of the posterior cruciate ligament. Two statistically significant differences were found; range of motion was 2.4 ° higher in the posterior cruciate ligament sacrificing group, however results were heterogeneous; and the mean functional Knee Society Score was 2.3 points higher in the posterior cruciate ligament sacrificing group. These differences are clinically not relevant.