A systematic review of conflicting meta-analyses in orthopaedic surgery

Overview of systematic reviews on periodontal-orthodontic interactions: A comprehensive literature analysis

The aims of this research were to investigate the methodological quality of systematic reviews on periodontal-orthodontic interactions (i.e. reviews of primary research broadly defined as any including both periodontic and orthodontic components) and to provide a mapping of the researched topics. We searched four major databases (PubMed, Lilacs, Web of Science, and Embase) for systematic reviews of periodontal-orthodontic interactions. We used the AMSTAR-2 tool (the acronym is derived from 'a measurement tool to assess systematic reviews') to assess the methodological quality of the included systematic reviews. Individual AMSTAR-2 ratings were tabulated, and the percentage per item was calculated. To assess the association between the AMSTAR-2 percentage score and the overall confidence in the systematic review results, an ordinal regression model was used. We initially retrieved 973 documents, and 43 systematic reviews were included. Systematic reviews of interventions were the most prevalent (n = 26, 60.5%). Most of the systematic reviews did not report a meta-analysis (n = 25, 58.1%). In addition, most of the studies included in the systematic reviews had an unclear or high risk of bias. Most of the systematic reviews were rated as having critically low or low overall confidence (n = 34, 79.1%). A significant correlation was found between the AMSTAR-2 percentage score and overall confidence in the results. The methodological quality of systematic reviews on periodontal-orthodontic interactions can be improved. The limitations of our study include potential language bias and an arbitrary classification of the topics researched.

How can clinicians choose between conflicting and discordant systematic reviews? A replication study of the Jadad algorithm

Introduction

The exponential growth of published systematic reviews (SRs) presents challenges for decision makers seeking to answer clinical, public health or policy questions. In 1997, an algorithm was created by Jadad et al. to choose the best SR across multiple. Our study aims to replicate author assessments using the Jadad algorithm to determine: (i) if we chose the same SR as the authors; and (ii) if we reach the same results.

Methods

We searched MEDLINE, Epistemonikos, and Cochrane Database of SRs. We included any study using the Jadad algorithm. We used consensus building strategies to operationalise the algorithm and to ensure a consistent approach to interpretation.

Results

We identified 21 studies that used the Jadad algorithm to choose one or more SRs. In 62% (13/21) of cases, we were unable to replicate the Jadad assessment and ultimately chose a different SR than the authors. Overall, 18 out of the 21 (86%) independent Jadad assessments agreed in direction of the findings despite 13 having chosen a different SR.

Conclusions

Our results suggest that the Jadad algorithm is not reproducible between users as there are no prescriptive instructions about how to operationalise the algorithm. In the absence of a validated algorithm, we recommend that healthcare providers, policy makers, patients and researchers address conflicts between review findings by choosing the SR(s) with meta-analysis of RCTs that most closely resemble their clinical, public health, or policy question, are the most recent, comprehensive (i.e. number of included RCTs), and at the lowest risk of bias.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01750-2.

This is the first empirical study to replicate Jadad algorithm assessments to evaluate discordance across systematic reviews.

In 62% (13/21) of cases, we were unable to replicate the Jadad algorithm assessment and ultimately chose a different systematic review than the authors.

When assessing systematic reviews using the Jadad algorithm, some steps of the Jadad algorithm were vague in description, making it difficult to operationalise, interpret, and use.

The Jadad algorithm has several limitations as it does not account for the last literature search of the systematic review and publication recency of included trials.

To assess discordance in the absence of an algorithm, we recommend decision makers consider relevance (objectives that most closely resemble their clinical question), recency (dates of search), comprehensiveness (most trials), and risk of bias (lowest risk of bias SR) when choosing one systematic review across multiple.

Implementing living evidence to inform health decisions: A strategy for building capacity in health sector (Protocol)

Every day important healthcare decisions are made with incomplete or outdated information about the effects of the healthcare interventions available, what delivers the best value for the health system and where more research is needed. It is necessary to invest in strategies that allow access to reliable and updated evidence on which to base health decisions. The objective is to develop and evaluate a strategy for building the capacity among different actors of a country's health system to implement the model known as "Living Evidence" [LE] in the evidence synthesis and dissemination of knowledge transfer [KT] products to inform health decisions. The study will involve professional members of health system organizations in charge of developing KT products to inform health decisions. The project will be developed in three complementary phases: 1) LE-implementation framework development through review of the literature, brainstorming meetings, user testing, and expert consultation; 2) training in LE tools and strategies; 3) developing LE synthesis for KT products by applying the framework to real-life diverse situations. To achieve the capacity-building strategy assessment goal, several surveys and interviews will take place during the process to assess: 1) the LE-implementation framework for the incorporation of LE synthesis in the development of KT products; 2) the training workshops; 3) the whole capacity-building strategy used for health system organizations be able of implementing the LE as part of the KT products they regularly produce. The expected results are an effective capacity-building strategy for health system organizations to implement the living evidence model in different KT products; a LE-implementation framework to be applicable to any country or region to incorporate LE in the KT products; LE synthesis for KT products directly applicable to the real-setting situations; integration of Epistemonikos-L.OVE platform for keeping the LE process in the development and updating of KT products.

Identifying and addressing conflicting results across multiple discordant systematic reviews on the same question: protocol for a replication study of the Jadad algorithm

INTRODUCTION

An increasing growth of systematic reviews (SRs) presents notable challenges for decision-makers seeking to answer clinical questions. In 1997, an algorithm was created by Jadad to assess discordance in results across SRs on the same question. Our study aims to (1) replicate assessments done in a sample of studies using the Jadad algorithm to determine if the same SR would have been chosen, (2) evaluate the Jadad algorithm in terms of utility, efficiency and comprehensiveness, and (3) describe how authors address discordance in results across multiple SRs.

METHODS AND ANALYSIS

We will use a database of 1218 overviews (2000-2020) created from a bibliometric study as the basis of our search for studies assessing discordance (called discordant reviews). This bibliometric study searched MEDLINE (Ovid), Epistemonikos and Cochrane Database of Systematic Reviews for overviews. We will include any study using Jadad (1997) or another method to assess discordance. The first 30 studies screened at the full-text stage by two independent reviewers will be included. We will replicate the authors' Jadad assessments. We will compare our outcomes qualitatively and evaluate the differences between our Jadad assessment of discordance and the authors' assessment.

ETHICS AND DISSEMINATION

No ethics approval was required as no human subjects were involved. In addition to publishing in an open-access journal, we will disseminate evidence summaries through formal and informal conferences, academic websites, and across social media platforms. This is the first study to comprehensively evaluate and replicate Jadad algorithm assessments of discordance across multiple SRs.

Systematic reviews in spinal cord injury: A step-by-step guide for rehabilitation science learners and clinicians

BACKGROUND

The COVID-19 pandemic has created opportunity for multiple rehabilitation science learners and clinicians to critically evaluate and synthesize published research in the field of spinal cord injury (SCI) rehabilitation.

OBJECTIVE

To provide a step-by-step guide for rehabilitation science learners and clinicians outlining how to conduct rigorous systematic reviews in the field of SCI.

RESULTS

Steps for conducting a systematic review (SR) include: (1) formation of the SR team consisting of interprofessional experts; (2) formulation of the research question(s) with patient/population/problem, Intervention, Comparison, and Outcome (PICO) specification; (3) determination of inclusion and exclusion criteria; (4) development of SR protocol and registration; (5) development of the search strategies (database specific); (6) screening of titles and abstracts (level 1 screening), and full-texts (level 2 screening); (7) quality assessment of the included studies; (8) data extraction; (9) summary of findings and discussion; and, (10) dissemination of results.

CONCLUSIONS

The enclosed ten steps for conducting SRs in SCI rehabilitation research have the potential to significantly improve the quality of evidence synthesis and the associated inferences. The importance of assembling team with diverse expertise is emphasized to assure a quality product with the potential to influence practice and inform the content of clinical practice recommendations.

Intra-articular hyaluronic acid injection in treating knee osteoarthritis: assessing risk of bias in systematic reviews with ROBIS tool

OBJECTIVES

Intra-articular injection of hyaluronic acid (HA) is a common, yet controversial therapeutic option in treating knee osteoarthritis (OA). The purpose of the present study was to assess the risk of bias (RoB) of systematic reviews (SRs) and to summarize available evidence of HA in treating knee OA.

METHODS

A systematic search of SRs published through to December 2016 was conducted using the MEDLINE, EMBASE and Cochrane Library. The RoB of included SRs was assessed by ROBIS tool. In addition, the methodological quality of primary studies in SRs with low RoB was evaluated according to the Cochrane Handbook. The evidence quality of each primary outcome of SRs with low RoB was determined by the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system.

RESULTS

Thirty-one SRs were eligible for inclusion. According to the ROBIS tool, there were 13 SRs with low RoB, 16 with high RoB and two with unclear RoB. The methodological quality of a total of 135 primary studies was evaluated and summarized. Forty-two outcomes from these 13 SRs were classified into the four following quality levels based on the GRADE approach: three outcomes with high quality, eight with moderate quality, 12 with low quality and 19 with very low quality.

CONCLUSIONS

This study evaluated RoB in SRs for managing knee OA with HA and assessed the evidence quality of each primary outcome in SRs with low RoB. These results can help users of SRs to improve the process of SR assessment in developing overviews or guidelines, leading to more reliable recommendations for improvements in treating knee OA. Registration: PROSPERO ((http://www.crd.york.ac.uk/PROSPERO) [CRD42017057384].

Safety and efficacy of intra-articular injections of a combination of hyaluronic acid and mannitol (HAnOX-M) in patients with symptomatic knee osteoarthritis: Results of a double-blind, controlled, multicenter, randomized trial

BACKGROUND

To compare both safety and efficacy of a novel intra-articular viscosupplement made of intermediate molecular weight (MW) hyaluronic acid (HA) mixed with high concentration of mannitol with a marketed high MW HA, in patients with knee osteoarthritis (OA).

METHODS

Patients with symptomatic knee OA, with radiological OARSI grades 1 to 3, were enrolled in a controlled, double-blind, parallel-group, non-inferiority trial. They were randomized to receive three intra-articular injections, at weekly intervals, of either HAnOX-M made of a combination of HA (MW one to 1.5MDa, 31mg/2ml) and mannitol (70mg/2ml) or Bio-HA (MW 2.3 to 3.6MDa, 20mg/2ml). The primary outcome was six-month change in the WOMAC pain subscale (0 to 20). Sample size was calculated according to a non-inferiority margin of 1.35. Secondary endpoints included six-month change in function and walking pain, analgesic consumption and safety.

RESULTS

The intention-to-treat (ITT) and per-protocol (PP) populations consisted of 205 and 171 patients. HAnOX-M and Bio-Ha groups did not differ statistically at baseline. The primary analysis was conducted in the PP population, then in the ITT population. The average WOMAC pain score at baseline was 9.5 in both groups. Mean (SD) variations in WOMAC pain score were -4.4 (3.8) and -4.5 (4.3) mm, for HAnOX and Bio-HA respectively, satisfying the claim for non-inferiority. Similar results were obtained for all other secondary endpoints.

CONCLUSION

Treatment with of HAnOX-M is effective to alleviate knee OA symptoms and to improve joint function over six months, with similar safety than conventional HA viscosupplement.

A Systematic Summary of Systematic Reviews on the Topic of the Anterior Cruciate Ligament

BACKGROUND

There has been a substantial increase in the amount of systematic reviews and meta-analyses published on the anterior cruciate ligament (ACL).

PURPOSE

To quantify the number of systematic reviews and meta-analyses published on the ACL in the past decade and to provide an overall summary of this literature.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of all ACL-related systematic reviews and meta-analyses published between January 2004 and September 2014 was performed using PubMed, MEDLINE, and the Cochrane Database. Narrative reviews and non-English articles were excluded.

RESULTS

A total of 1031 articles were found, of which 240 met the inclusion criteria. Included articles were summarized and divided into 17 topics: anatomy, epidemiology, prevention, associated injuries, diagnosis, operative versus nonoperative management, graft choice, surgical technique, fixation methods, computer-assisted surgery, platelet-rich plasma, rehabilitation, return to play, outcomes assessment, arthritis, complications, and miscellaneous.

CONCLUSION

A summary of systematic reviews on the ACL can supply the surgeon with a single source for the most up-to-date synthesis of the literature.

[Injection treatment with hyaluronic acid]

This article presents the spectrum of indications for the use of hyaluronic acid (HA) based on the recommendations of the European League Against Rheumatism (EULAR), the American College of Rheumatology (ACR), the Osteoarthritis Research Society International (OARSI), the International Institute for Health and Clinical Excellence (NICE) and the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) taking the reality of patient care in Europe into account.

Consensus statement on viscosupplementation with hyaluronic acid for the management of osteoarthritis

Viscosupplementation (VS) with hyaluronic acid is currently used by physicians to treat osteoarthritis. However, many aspects of this treatment remain questionable and subject of controversy. A group of 8 experts in this field, from European countries, met to debate on 24 statements previously listed by the group members. Based on an extensive research of the literature and expert opinion, a consensus position has been proposed for each statement. Agreement was achieved on some recommendations. In particular, the expert achieved unanimous agreement in favor of the following statements: VS is an effective treatment for mild to moderate knee OA; VS is not an alternative to surgery in advanced hip OA; VS is a well-tolerated treatment of knee and other joints OA; VS should not be used only in patients who have failed to respond adequately to analgesics and NSAIDs; VS is a "positive" indication but not a "lack of anything better" indication; the dosing regimen must be supported by evidence-based medicine; cross-linking is a proven means for prolonging IA residence time of HA; the best approach to inject accurately knee joint is the lateral mid-patellar one; when VS is performed under fluoroscopy, the amount of radiopaque contrast agent must be as low as possible to avoid viscosupplement dilution. These clear recommendations have been established to help practitioners in the use of viscosupplementation.

Complications and cancer rates in spine fusion with recombinant human bone morphogenetic protein-2 (rhBMP-2)

PURPOSE

To quantitatively synthesize the available best evidence for general complications, heterotopic ossification (HO), retrograde ejaculation, cervical swelling, and cancer rates with the use of rhBMP-2 in lumbar and cervical spine fusion.

METHODS

We conducted an online search for relevant controlled trials and extracted data on the abovementioned endpoints. Studies were eligible for inclusion if they reported on spinal fusion with rhBMP-2 in humans. Publication bias and heterogeneity were assessed mathematically. These data were synthesized in a meta-analysis using DerSimonian-Laird random effects modeling to calculate pooled odds ratios.

RESULTS

We identified 26 studies reporting on a total of 184,324 patients (28,815 experimental, 155,509 controls) with a mean age of 51.1 ± 1.8 years. There was a significantly higher risk of general complications with rhBMP-2 compared to iliac crest bone graft (ICBG) with an odds ratio (OR) of 1.78 (95 %CI 1.20-2.63), (p = 0.004). The odds ratio for HO was 5.57 (95 %CI 1.90-16.36), (p = 0.002), for retrograde ejaculation 3.31 (95 %CI 1.20-9.09), (p = 0.020), and for cervical swelling 4.72 (95 %CI 1.42-15.67), (p = 0.011), all significantly higher in the rhBMP-2 group. The pooled odds ratio for new onset of tumor was 1.35 (95 %CI 0.93-1.96), which represents no statistically significant difference between the groups (p = 0.111).

CONCLUSION

rhBMP-2 is associated with a higher rate of general complications as well as retrograde ejaculation, HO, and cervical tissue swelling in spine fusion. There is a slightly increased risk of new onset of tumors, however, without statistical significance.

Immobilization in internal or external rotation does not change recurrence rates after traumatic anterior shoulder dislocation

BACKGROUND

The objective of this study was to systematically review and quantitatively synthesize the data on recurrence rates after shoulder immobilization in internal versus external rotation in first-time, traumatic shoulder dislocations.

MATERIALS AND METHODS

We performed a systematic search of the keywords "(((external rotation) OR internal rotation) AND immobilization) AND shoulder" in the online databases PubMed, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and the Cochrane Library. Random-effects models were used to calculate the cumulatively pooled risk ratios (RRs) of recurrent shoulder dislocations. All analyses were also stratified by age.

RESULTS

We included 5 studies with a total of 471 patients (230 internal rotation and 241 external rotation) published between 2001 and 2011 in English. The pooled random-effects RR for recurrence of shoulder dislocations at all ages was 0.74 (95% confidence interval [CI], 0.44-1.27; P = .278). The RR was 0.70 (95% CI, 0.38 to 1.29; P = .250) for patients aged 30 years or younger and 0.78 (95% CI, 0.32 to 1.88; P = .579) for those aged older than 30 years.

CONCLUSION

The current best evidence does not support a relative effectiveness of immobilization in external rotation compared with internal rotation to avoid recurrent shoulder dislocations in patients with traumatic anterior shoulder dislocations.

Dealing with clinical heterogeneity in meta-analysis. Assumptions, methods, interpretation

OBJECTIVE

There is an ongoing debate how to interpret findings of meta-analyses when substantial clinical heterogeneity is present among included trials. The aim of the present study was to demonstrate various ways of dealing with clinical heterogeneity along with underlying assumptions and interpretation. A recent meta-analysis on long-term psychodynamic psychotherapy (LTPP) was used as an illustrative example.

METHOD

Re-analysis of published data including calculation of a prediction interval, heterogeneity tests, Bayesian meta-analysis, meta-regression, and subgroup analysis to explore and interpret summary estimates in clinically heterogeneous studies.

RESULTS

Meta-analytic results and their implications varied considerably depending on whether and how clinical heterogeneity was addressed.

CONCLUSIONS

Whether or not to trust summary estimates in meta-analysis depends largely on the subjective relevance of clinical heterogeneity present. No single analysis and interpretation strategy can be valid in every context or paradigm, thus, reflection of own beliefs on the role of heterogeneity is needed.

Rationale for and methods of superiority, noninferiority, or equivalence designs in orthopaedic, controlled trials

BACKGROUND

To provide value-based healthcare in orthopaedics, controlled trials are needed to assess the comparative effectiveness of treatments. Typically comparative trials are based on superiority testing using statistical tests that produce a p value. However, as orthopaedic treatments continue to improve, superiority becomes more difficult to show and, perhaps, less important as margins of improvement shrink to clinically irrelevant levels. Alternative methods to compare groups in controlled trials are noninferiority and equivalence. It is important to equip the reader of the orthopaedic literature with the knowledge to understand and critically evaluate the methods and findings of trials attempting to establish superiority, noninferiority, and equivalence.

QUESTIONS/PURPOSES

I will discuss supplemental and alternative methods to superiority for assessment of the outcome of controlled trials in the context of diminishing returns on new therapies over old ones.

METHODS

The three methods-superiority, noninferiority, and equivalence-are presented and compared, with a discussion of implied pitfalls and problems.

RESULTS

Noninferiority and equivalence offer alternatives to superiority testing and allow one to judge whether a new treatment is no worse (within a margin) or substantively the same as an active control. Noninferiority testing also allows for inclusion of superiority testing in the same study without the need for adjustment of the statistical methods.

CONCLUSIONS

Noninferiority and equivalence testing might prove most valuable in orthopaedic, controlled trials as they allow for comparative assessment of treatments with similar primary end points but potentially important differences in secondary outcomes, safety profiles, and cost-effectiveness.

Treating anterior cruciate ligament tears in skeletally immature patients

PURPOSE

To systematically review the current evidence for conservative and surgical treatment of anterior cruciate ligament (ACL) tears in skeletally immature patients.

METHODS

A systematic search of PubMed, CINAHL, EMBASE, CCTR, and CDSR was performed for surgical and/or conservative treatment of complete ACL tears in immature individuals. Studies with less than six months of follow-up were excluded. Study quality was assessed and data were collected on clinical outcome, growth disturbance, and secondary joint damage.

RESULTS

We identified 48 studies meeting the inclusion criteria. Conservative treatment was found to result in poor clinical outcomes and a high incidence of secondary defects, including meniscal and cartilage injury. Surgical treatment had only very weak evidence for growth disturbance, yet strong evidence of good postoperative stability and function. No specific surgical treatment showed clearly superior outcomes, yet the studies using physeal-sparing techniques had no reported growth disturbances at all.

CONCLUSIONS

The current best evidence suggests that surgical stabilization should be considered the preferred treatment in immature patients with complete ACL tears. While physeal-sparing techniques are not associated with a risk of growth disturbance, transphyseal reconstruction is an alternative with a beneficial safety profile and a minimal risk of growth disturbance. Conservative treatment commonly leads to meniscal damage and cartilage destruction and should be considered a last resort.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III, and IV studies.

The prevalence and effect of publication bias in orthopaedic meta-analyses

BACKGROUND

Meta-analyses of randomized, controlled trials are considered the highest level-of-evidence, thus strongest source of information. However, questions concerning the validity of meta-analyses in orthopaedic surgery emerged recently. Among the most common sources for errors is publication bias. This describes the fact that studies with small or non-significant outcomes are less likely to be published, thus less likely to be identified and included in systematic reviews and meta-analyses. In this study we asked three questions: (1) Whether publication bias is assessed in orthopaedic meta-analyses, (2) What the actual prevalence of publication bias is, and (3) what effect publication bias has on the outcomes of orthopaedic meta-analyses.

METHODS

Using the estimate of 35 ± 20% for the prevalence of publication bias in meta-analyses obtained from earlier research we calculated a required samples size of 22 (plus 20% to account for attrition) and randomly selected 26 orthopaedic meta-analyses. To answer our first question we calculated the percentage of papers that report on formal assessment of publication bias. For our second question we obtained all primary studies (n = 321) from the included meta-analyses and used Egger's regression to search for evidence for publication bias. Third, we used the trim-and-fill method to assess the impact of publication bias, if present. This method estimates publication bias in a meta-analysis and adds hypothetical studies to reduce this bias; it thus produces an estimate of adjusted, unbiased outcomes that can be compared with the unadjusted, publication-biased outcomes to assess the effect of publication bias.

RESULTS

We found that only 35% (95% CI 20-57) of all orthopaedic meta-analyses published between 1992 and 2008 in English and German assessed publication bias. Most studies used funnel plots, which are rather insensitive. The prevalence of publication bias, based on a sensitivity analysis, ranged between 12 and 19%. Adjustment for publication bias did not produce significantly different results, but the magnitude of the pooled estimates in the affected meta-analyses changed by 29% (95% CI 0-63) on average.

CONCLUSION

We found a rather low prevalence of publication bias in orthopaedic meta-analyses, but recommend assessing for it and its effects, which might be substantial.

Does autograft choice determine intermediate-term outcome of ACL reconstruction?

PURPOSE

Many clinical studies and systematic reviews have compared the short-term (2 years) outcomes of ACL reconstruction with hamstring and patellar tendon autograft. Few differences have been observed, with the exception of increased kneeling pain with patellar tendon grafts. The goal of this systematic review is to determine whether there are differences in clinical, patient-reported, or radiographic outcomes based on graft choice at a minimum of 5 years after ACL reconstruction.

METHODS

A systematic review was performed to identify all prospective outcome studies comparing patellar tendon and hamstring autograft ACL reconstruction with minimum follow-up of at least 5 years. Seven studies were identified and meta-analysis of select data determined to be sufficiently homogenous was performed (failure and laxity).

RESULTS

Five randomized controlled trials and two prospective cohorts comparing hamstring and patellar tendon autografts were identified. Clinical assessment [failure rate, International Knee Documentation Committee (IKDC) class, Lachman, pivot shift, and KT 1000 testing] showed no difference between grafts. Patient-reported outcomes (Lysholm, Cincinnati, and IKDC) showed no difference. Both anterior knee pain (3/3 studies) and kneeling pain (4/4 studies) were more frequent in the patellar tendon group. However, the patient-reported outcomes in these studies were not different. Radiographic evidence of osteoarthritis was inconsistent between autograft choices.

CONCLUSION

This level II systematic review demonstrates no difference in major clinical results between graft types with the exception of increased anterior knee and kneeling pain. There exists a potential for increased incidence of osteoarthritis in the patellar tendon group but increased sample size is required. These longer-term outcomes are similar to results of prior systematic reviews with two-year follow-up.

Does minimally invasive surgery improve short-term recovery in total knee arthroplasty?

BACKGROUND

Concerns have been raised regarding minimally invasive surgery (MIS) and its possible effect on postoperative functional recovery, complications, and survival rate after TKA.

QUESTIONS/PURPOSES

We specifically asked whether MIS TKA would be associated with (1) increased operative time, (2) reduced blood loss, (3) shortened hospital stay, (4) faster recovery of ROM, (5) higher knee scores, (6) inferior component positioning, and (7) increased complications.

METHODS

We performed a systematic literature search of randomized controlled trials between minimally invasive and standard approaches in TKA that compared operative time, blood loss, ROM, knee scores, component positioning, and complications. We conducted a systematic review and meta-analysis of 13 trials published from 2007 to 2009 of MIS versus standard TKA.

RESULTS

Patients in the MIS group had longer operating times (10-19 minutes). Mean Knee Society scores were better after MIS than after the standard procedure at 6 and 12 weeks postoperatively, but not after 6 months. Improvement in ROM occurred more rapidly in the MIS group 6 days after TKA but later improvements are not clearly documented. We identified no differences between minimally invasive and standard approaches regarding the short-term overall complications and alignment of femoral and tibial components. However, wound healing problems and infections occurred more frequently in the MIS group.

CONCLUSIONS

MIS leads to faster recovery than conventional surgery with similar rates of component malalignment but is associated with more frequent delayed wound healing and infections. Potential benefits in long-term survival rate and functional improvement require additional investigation. Level of Evidence Level II, therapeutic study (systematic review). See the Guidelines for Authors for a complete description of levels of evidence.

Anterior cruciate ligament reconstruction results in alterations in gait variability

INTRODUCTION

The temporal structure of gait variability has shown that healthy human gait exhibits long-range correlations and deterministic properties which allow the neuromuscular system to be flexible and adaptable to stresses. Pathology results in deterioration of these properties. We examined structure of gait variability after ACL reconstruction with either BPTB or quadrupled ST/G tendon autografts.

METHODS

Six patients with BPTB reconstruction, six with ST/G reconstruction and six healthy controls walked on a treadmill at their self-selected pace. Two minutes of continuous kinematic data were recorded with a 6-camera optoelectronic system. The nonlinear measure of the largest Lyapunov Exponent (LyE) was estimated from the knee flexion-extension time series from 100 continuous walking strides to assess the structure of gait variability.

RESULTS

The reconstructed limbs in both reconstructed groups exhibited significantly larger LyE values than the control limbs (p<0.05), even though clinical outcomes indicated complete restoration. No significant differences were found between the two autografts. In addition, the intact contralateral leg produced significant higher LyE values as compared with the ACL-reconstructed leg in both groups. No interaction was found.

DISCUSSION

The larger LyE values indicate that the reconstructed knees of both reconstructed groups exhibit more divergence in the movement trajectories during gait. The larger Lye values found in the intact leg in both reconstructed groups could be interpreted as a compensatory mechanism. However, the increased divergence found in both limbs may present an alternative explanation for the impaired neuromuscular performance and increased susceptibility to future pathology, which is supported by the increased amount of osteoarthritis found in ACL-reconstructed patients.