The Minimal Clinically Important Difference: A Review of Clinical Significance

Background: The minimal clinically important difference (MCID) is a term synonymous with orthopaedic clinical research over the past decade. The term represents the smallest change in a patient-reported outcome measure that is of genuine clinical value to patients. It has been derived in a myriad of ways in existing orthopaedic literature. Purpose: To describe the various modalities for deriving the MCID. Study Design: Narrative review; Level of evidence, 4. Methods: The definitions of common MCID determinations were first identified. These were then evaluated by their clinical and statistical merits and limitations. Results: There are 3 primary ways for determining the MCID: anchor-based analysis, distribution-based analysis, and sensitivity- and specificity-based analysis. Each has unique strengths and weaknesses with respect to its ability to evaluate the patient’s clinical status change from baseline to posttreatment. Anchor-based analyses are inherently tied to clinical status yet lack standardization. Distribution-based analyses are the opposite, with strong foundations in statistics, yet they fail to adequately address the clinical status change. Sensitivity and specificity analyses offer a compromise of the other methodologies but still rely on a somewhat arbitrarily defined global transition question. Conclusion: This current concepts review demonstrates the need for (1) better standardization in the establishment of MCIDs for orthopaedic patient-reported outcome measures and (2) better study design—namely, until a universally accepted MCID derivation exists, studies attempting to derive the MCID should utilize the anchor-based within-cohort design based on Food and Drug Administration recommendations. Ideally, large studies reporting the MCID as an outcome will also derive the value for their populations. It is important to consider that there may be reasonable replacements for current derivations of the MCID. As such, future research should consider an alternative threshold score with a more universal method of derivation.

The Fragility of Statistical Significance in Patellofemoral Instability Research: A Systematic Review

Background: Fragility analysis is increasingly utilized to evaluate the robustness of results within the orthopaedic literature and has frequently revealed instability of reported outcomes. Purpose/Hypothesis: The purpose of this investigation was to utilize a fragility analysis to evaluate the stability of reported results in the patellofemoral instability (PFI) literature. We hypothesized the demonstration of significant fragility in patellofemoral research to be similar to that identified throughout other areas of the orthopaedic literature. Study Design: Systematic review; Level of evidence, 4. Methods: The PubMed database was queried from January 1, 2000, to October 10, 2020 for comparative trials in 10 prominent orthopaedic journals that reported dichotomous outcomes related to the management of PFI. The fragility index (FI) and the fragility quotient (FQ) were calculated for each individual outcome event, and the overall FI and FQ were determined for all included studies. Results: A total of 22 comparative studies comprising 11 randomized controlled trials and 11 nonrandomized trials were included for the analysis. A total of 75 outcome events underwent a fragility analysis and revealed a median FI and FQ of 3 (interquartile range [IQR], 1-5) and 0.043 (IQR, 0.018-0.081), respectively. Also 27% of included studies reported loss to follow-up greater than the overall FI, therefore suggesting the maintenance of the follow-up may have resulted in the reversal of significance. Conclusion: The result of the comprehensive fragility analysis demonstrated a lack of robustness in PFI research with the alteration of only a few outcome events required to reverse statistical significance. We therefore recommend the triple reporting of the P value, the FI, and the FQ to aid in the interpretation of the statistical integrity of future comparative trials in the PFI literature.

Current Trends in Orthobiologics: An 11-Year Review of the Orthopaedic Literature

Background: The use of “orthobiologics” or regenerative therapies in orthopaedic surgery has grown in recent years. Particular interest has been raised with regard to platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells. Although studies have analyzed outcomes after orthobiologic treatment, no study has analyzed how the literature as a whole has evolved. Purpose: To evaluate trends in platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cell publications and to assess how these might inform efforts to establish minimum reporting standards and forecast future use. Study Design: Systematic review; Level of evidence, 4. Methods: A database was compiled systematically using PubMed to identify articles published between 2009 and 2019 within 9 prominent orthopaedic journals and pertaining to the use of platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells in the treatment of musculoskeletal conditions. Included articles were classified as clinical, nonclinical (translational or basic science), or review, and a variety of study parameters were recorded for each. Additional queries were performed to identify articles that utilized minimum reporting standards. Results: A total of 474 articles (132 clinical, 271 nonclinical, 71 review) were included, consisting of 244 (51.5%) platelet-rich plasma, 146 (30.8%) bone marrow aspirate, 72 (15.2%) adipose-derived cells, and 12 (2.5%) amniotic cells. The greatest annual increase in publications for each orthobiologic topic was from 2018 to 2019. The American Journal of Sports Medicine demonstrated the highest number of overall (34.2%) and clinical (50.0%) publications, and accounted for 44.3% of all platelet-rich plasma publications. The Journal of Orthopaedic Research accounted for the second highest overall number of publications (24.9%) and highest nonclinical publications (41.0%). Platelet-rich plasma accounted for 91.5% of all level 1 clinical studies, while much greater than half of bone marrow aspirate, adipose-derived cells, and amniotic cell publications were level 3 or lower. Out of the 207 articles that used some form of reporting protocol, 59 (28.5%) used an established algorithm and 125 (60.4%) used their own. Conclusion: Interest in orthobiologics continues to grow, as evidenced by an increasing trend in publications over an 11-year period. However, current reporting on orthobiologic formulations is largely heterogeneous, emphasizing the need for minimum reporting standards and higher-quality studies.

Posterolateral corner knee injuries: a narrative review

Limited knowledge of the anatomy and biomechanics of the posterolateral corner (PLC) of the knee, coupled with poor patient outcomes with non-operative management, resulted in the PLC often being labelled as the ‘dark side’ of the knee. In the last two decades, extensive research has resulted in a better understanding of the anatomy and function of the PLC, and has led to the development of anatomic reconstructions that have resulted in improved patient outcomes. Despite considerable attention in the clinical orthopaedic literature (nearly 400 articles published in the last decade), a standardized algorithm for the diagnosis and treatment of the PLC is still lacking, and much controversy remains. Considering the literature review, there is not a reconstruction technique that clearly prevails over the others. As anatomic, biomechanical, and clinical knowledge of PLC injuries continues to progress, finding the balance between re-creating native anatomy and safely performing PLC reconstruction provides a big challenge. Treatment decisions should be made on a case-by-case basis. Cite this article: EFORT Open Rev 2021;6:676-685. DOI: 10.1302/2058-5241.6.200096

PROMIS Global-10 poorly correlates with legacy outcomes for patients undergoing hip arthroscopy

ABSTRACT The Patient-Reported Outcomes Measurement Information System (PROMIS) Global-10 assesses generic-related quality of life, but has not been well studied in the orthopaedic literature. The purpose was to compare PROMIS Global-10 and legacy hip-specific patient-reported outcome measures (PROMs) in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS). This study included patients who underwent primary hip arthroscopy with complete preoperative and 6-month post-operative follow-up. PROMIS Global-10 Physical (PROMIS-P) and Mental (PROMIS-M) components, as well as the modified Harris hip score (mHHS) and International Hip Outcome Tool-33 (iHOT-33) were assessed. PROM analysis included: post-operative changes, correlations, floor and ceiling effects and responsiveness. Final analysis included 112 patients. Average age and body mass index were 36.1±11.7 years and 24.8±3.9 kg/m2, respectively. All 6-month PROMs, except PROMIS-M, were significantly improved compared to preoperative level (P<0.02). Preoperatively, PROMIS-P was poorly correlated with mHHS and iHOT-33 (rs <0.4) whereas PROMIS-M was only poorly correlated with iHOT-33 (rs <0.4, 95% CI of 0.02–0.37). Post-operatively, the iHOT-33 was poorly correlated with both PROMIS measures (rs <0.4). The mHHS was fairly correlated with both PROMIS measures (rs <0.6) post-operatively. The effect sizes for mHHS and iHOT-33 were high (d=1.2 and 1.40, respectively), whereas the effect sizes for PROMIS Global-10 were small (d<0.3). PROMIS Global-10 demonstrated lower effect sizes and poor to fair correlation with legacy hip-specific PROMs, and appears to have a limited role in the assessment of patients undergoing hip arthroscopy for FAIS. Therefore, the PROMIS Global-10 may have a limited role in assessing patients with FAIS.