Partial-thickness rotator cuff tears

Hyaluronate Acid Plus Platelet-Rich Plasma Is Superior to Steroids for Pain Relief Less Than 6 Months Using Injection Therapy of Partial Rotator Cuff Tears: A Systematic Review and Network Meta-analysis

PURPOSE

To compare the efficacy of steroid injections to other injectable therapies in partial-thickness rotator cuff (RC) tears.

METHODS

A systematic literature search was performed until October 25, 2021, in 3 databases (Cochrane Central Register of Controlled Trials, Embase, MEDLINE). Eligible studies compared the efficacy of steroid, hyaluronic acid (HA), platelet-rich plasma (PRP), the combination of HA and PRP (HA + PRP), and adipose-derived regenerative cells in RC tears. The primary outcomes were the visual analog scale (VAS), Constant-Murley Shoulder Outcome Score (CMS) and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form. Using paired and network meta-analysis, we calculated pooled mean differences (MDs) with 95% confidence intervals (CIs).

RESULTS

We included a total of 7 articles in the quantitative synthesis. In shorter periods, the HA + PRP combination was superior to the other substances we investigated (HA + PRP: VAS [0-4 weeks]: MD: -0.99 [95% CI, -1.62 to -0.36]; CMS [0-3 months]: 20.56 [95% CI, 16.18 to 24.94]. This combination was followed by the use of HA or PRP alone, depending on the duration of follow-up and the outcome being studied. In our study, short-term results suggest that saline is superior to steroids for partial tears, but this trend is reversed at 6-month follow-up.

CONCLUSIONS

The HA and PRP combination is currently the most effective in partial RC tear treatment in the short term. After 6 months, there is no meaningful difference, so the benefits of the combination are short term.

LEVEL OF EVIDENCE

Level II, including Level I to II studies.

Partial-thickness rotator cuff tears: a review of current literature on evaluation and management

Rotator cuff disease is a common cause of shoulder pain for which partial-thickness rotator cuff tears occupy a significant proportion. Such tears are often difficult to diagnose and manage in the general clinic setting. A review of the available literature from well-known databases was performed in this study to provide a concise overview of partial-thickness rotator cuff tears to aid physicians in their understanding and management.

Regenerative Medicine Solutions for Rotator Cuff Injuries in Athletes: Indications and Outcomes

Rotator cuff (RC) injuries include a wide range of pathologic states. Athletes are perhaps the most susceptible to RC injuries ranging from tendinopathy to partial or full-thickness tears, due to functional overload and repetitive movements, causing abstention from sports for long periods. Regenerative medicine keeps giving us multiple choices to fight the disability caused by these pathologies. A literature search was performed, and findings related to the structure-function of rotator cuff units, pathophysiology of injuries, regenerative medicine treatments, and future strategies were outlined. Platelet-rich plasma (PRP) has a greater number of articles and clinical trials, accompanied by stem cells progenitor, prolotherapy, and new approaches such as microfragmented adipose tissue and exosomes. RC injuries in athletes can cause pain, functional impotence, and the risk of recurrence, and can lead them to stop playing sports. Regenerative medicine offers a range of treatments, but some of them need further studies to underline their actual validity.

Role of platelet-rich plasma in the treatment of rotator cuff tendinopathy

Shoulder pain is a common musculoskeletal complaint, and rotator cuff (RC) pathologies are one of the main causes. The RC undergoes various tendinopathic and avascular changes during the aging process. Other degenerative changes affecting its healing potential make it an appealing target for biological agents. Platelet-rich plasma (PRP) has demonstrated the potential to deliver a high concentration of several growth factors and anti-inflammatory mediators, and its clinical use is mainly supported by experiments that demonstrated its positive effect on muscle, ligaments, and tendinous cells. This review aimed to specify the role of PRP and its future applications in RC tendinopathies based on the current clinical evidence. Due to the different characteristics and conflicting outcomes, clinicians should use PRP with moderate expectations until more consistent evidence is available. However, it is reasonable to consider PRP in patients with contraindications to corticosteroid injections or those with risk factors for inadequate healing. Its autologous origin makes it a safe treatment, and its characteristics make it a promising option for treating RC tendinopathy, but the efficacy has yet to be established.

Comparison of ultrasound-guided subacromial corticosteroid and ozone (O2-O3) injections in the treatment of chronic rotator cuff tendinopathy: a randomized clinical trial

Background

: The authors aimed to compare the effects of a one-time ultrasound (US)-guided subacromial corticosteroid injection and three-time ozone (O₂-O₃) injection in patients with chronic supraspinatus tendinopathy.

Methods

: Participants were randomly assigned to the corticosteroid group (n = 22) or ozone group (n = 22). Injections in both groups were administered into subacromial bursa with an US-guided in-plane posterolateral approach. Primary outcome measure was the change in the Western Ontario Rotator Cuff Index (WORC) score between baseline and 12-weeks post-injection. Secondary outcome measures included visual analog scale and Shoulder Pain and Disability Index scores. Assessments were recorded at baseline, and 4-weeks and 12-weeks post-injection.

Results

: Forty participants completed this study. Based on repeated measurement analysis of variance, a significant effect of time was found for all outcome measures in both groups. Both the groups showed clinically significant improvements in shoulder pain, quality of life, and function. Baseline, 4-week post-injection, and 12-week post-injection WORC scores (mean ± standard deviation) were 57.91 ± 18.97, 39.10 ± 20.50 and 37.22 ± 27.31 in the corticosteroid group, respectively and 69.03 ± 15.89, 39.11 ± 24.36, and 32.26 ± 24.58 in the ozone group, respectively. However, no significant group × time interaction was identified regarding all outcome measures.

Conclusions

: Three-time ozone injection was not superior to a one-time corticosteroid injection in patients with chronic supraspinatus tendinopathy. It might be as effective as corticosteroid injection at 4-weeks and 12-weeks post-injection in terms of relieving pain and improving quality of life and function.

Platelet rich plasma versus extracorporeal shock wave therapy in patients with non-calcific supraspinatous tears

Background

To compare the clinical efficacy of platelet rich plasma (PRP) subacromial injection and extracorporeal shock wave therapy (ESWT) on refractory non-calcific partial thickness supraspinatous tendon tear.

Results

Significant improvement in all outcome measures achieved in both groups at 4 weeks follow-up period (the end of treatment course) (P< 0.05). At 12 weeks follow-up period, group I, showed significant improvement in all outcome measures compared to baseline and group II; however, in group II, there was no significant difference compared to baseline; moreover, deterioration in the previous improvement was noticed.

Conclusion

Both PRP (group I) and ESWT (group II) are effective therapeutic methods in the management of refractory non-calcific partial thickness supraspinatous tendon tear; however, PRP (group I) has better long-term effects on both pain and function.

A comparative study of arthroscopic débridement versus repair for Ellman grade II bursal-side partial-thickness rotator cuff tears

HYPOTHESIS

We aimed to report the clinical outcomes of arthroscopic débridement vs. repair for Ellman grade II bursal-side partial-thickness rotator cuff tears.

METHODS

Patients who presented with Ellman grade II bursal-side partial-thickness rotator cuff tears from September 2015 to August 2017 were included. On the basis of preoperative findings and patient preference, 20 patients underwent débridement whereas 26 underwent arthroscopic repair. The visual analog scale (VAS), Constant-Murley shoulder, American Shoulder and Elbow Surgeons, and University of California-Los Angeles scores were assessed. Magnetic resonance imaging and B-mode ultrasonography were performed preoperatively and at 6, 12, and 24 months postoperatively.

RESULTS

All 46 patients were available throughout follow-up. At 2 years postoperatively, the VAS score had improved from 6.42 ± 1.56 to 0.65 ± 0.51 in the débridement group and from 6.26 ± 1.32 to 0.75 ± 0.42 in the repair group. The VAS score differed significantly between the 2 groups at 6 months postoperatively. All patient-reported outcomes improved in both groups. The American Shoulder and Elbow Surgeons score (P = .009), Constant-Murley shoulder score (P = .014), and University of California-Los Angeles score (P = .030) differed significantly between the 2 groups (higher in the débridement group) at 6 months postoperatively. Finally, 44 patients having intact tendon repairs with no interval worsening of partial-thickness tears underwent postoperative scheduled magnetic resonance imaging and B-mode ultrasonography examinations.

CONCLUSION

Arthroscopic débridement and repair of Ellman grade II bursal-side partial-thickness rotator cuff tears achieved comparable clinical scores and low retear rates during 2 years of follow-up. However, débridement achieved better results, especially within 6 months postoperatively, and achieved a favorable prognosis up to 2 years postoperatively.

The Effectiveness of Ischemic Compression Technique on Pain and Function in Individuals With Shoulder Pain: A Systematic Review

OBJECTIVE

To systematically review current literature to determine the effectiveness of the ischemic compression (IC) technique on pain and function in individuals with shoulder pain.

METHODS

This review was conducted according to recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Collaboration for Systematic Reviews; a search was performed in the electronic databases PubMed, Cumulative Index to Nursing and Allied Health Literature, SPORTDiscus, Physiotherapy Evidence Database, and Web of Science. Randomized clinical trials and quasi-randomized clinical trials were included, and the methodological quality was evaluated through the Physiotherapy Evidence Database scale.

RESULTS

The search found 572 studies; of these, 71 were selected by title and, subsequently, 29 were selected through abstract analyses. After critical analyses, 5 studies were included. The methodological quality ranged from 4 (reasonable) to 9 (excellent) points. Pain was assessed by all studies using the visual analog scale, Global Perceived Effect scale, Numerical Rating Scale, pressure pain threshold, or Perceived Amelioration Numerical Scale. Function was evaluated by 3 studies through the Shoulder Pain and Disability Index; Neck Disability Index; American Shoulder and Elbow Surgeons Standardized Shoulder Assessment; and Disabilities of the Arm, Shoulder, and Hand questionnaires. The studies showed that the IC technique produces immediate and short-term positive effects for pain, and positive short-term effects for shoulder function in individuals with shoulder pain.

CONCLUSION

The IC technique seems to be beneficial for pain and shoulder function. However, caution is needed when considering this evidence owing to the limited quality of some studies, the few articles found, and the lack of standardization of the application parameters of the technique to facilitate its reproducibility.

Evaluation of the cross-sectional area of acromion process for shoulder impingement syndrome

Background

Anatomic changes in the acromion have been considered a main cause of shoulder impingement syndrome (SIS). To evaluate the relationship between SIS and the acromion process, we devised a new morphological parameter called the acromion process cross-sectional area (APA). We hypothesized that the APA could be an important morphologic diagnostic parameter in SIS.

Methods

We collected APA data from 95 patients with SIS and 126 control subjects who underwent shoulder magnetic resonance imaging (MRI). Then we measured the maximal cross-sectional area of the bone margin of the acromion process on MRI scans.

Results

The mean of APAs were 136.50 ± 21.75 mm² in the male control group and 202.91 ± 31.78 mm² in the male SIS group; SIS patients had significantly greater APAs (P < 0.001). The average of APAs were 105.38 ± 19.07 mm² in the female control group and 147.62 ± 22.90 mm² in the female SIS group, and the SIS patients had significantly greater APAs (P < 0.001). The optimal APA cut-off in the male group was 165.14 mm² with 90.2% sensitivity, 91.4% specificity, and an area under the curve (AUC) of 0.968. In the female group, the optimal cut-off was 122.50 mm² with 85.2% sensitivity, 84.9% specificity, and an AUC of 0.928.

Conclusions

The newly devised APA is a sensitive parameter for assessing SIS; greater APA is associated with a higher possibility of SIS. We think that this result will be helpful for the diagnosis of SIS.

Agreement between physical therapists and radiologists of stratifying patients with shoulder pain into new treatment related categories using ultrasound; an exploratory study

STUDY DESIGN

A systematic overview of the literature and an agreement study.

OBJECTIVES

The aim of this study is to explore the inter-professional agreement of diagnostic musculoskeletal ultrasound (DMUS) between physical therapists (PT) and radiologists, using a new classification strategy based upon the therapeutic consequences in patients with shoulder pain.

BACKGROUND

DMUS is frequently used by PTs, although the agreement regarding traditional diagnostic labels between PTs and radiologists is only fair. Nevertheless, DMUS could be useful when used as a stratifying-tool.

METHODS

First, a systematic overview of current evidence was performed to assess which traditional diagnostic labels could be recoded into new treatment related categories (referral to secondary care, corticosteroid injections, physical therapy, watchful waiting). Next, kappa values were calculated for these categories between PTs and radiologists.

RESULTS

Only three categories were extracted, as none of the traditional diagnostic labels were classified into the 'corticosteroid injection' category. Overall, we found moderate agreement to stratify patients into treatment related categories and substantial agreement for the category 'referral to secondary care'. Both categories 'watchful waiting' and 'indication for physical therapy' showed moderate agreement between the two professions.

CONCLUSION

Our results indicate that the agreement between radiologists and PTs is moderate to substantial when labelling is based on treatment consequences. DMUS might be able to help the PT to guide treatment, especially for the category 'referral to secondary care' as this showed the highest agreement. However, as this is just an explorative study, more research is needed, to validate and assess the consequences of this stratification classification for clinical care.

The value of sonoelastography in the diagnosis of supraspinatus tendinopathy-a comparison study

OBJECTIVE:

This study assessed the association between tendon stiffness on sonoelastography and grades of tendinopathy on MRI in patients with supraspinatus tendinopathy.

METHODS:

25 consecutive adult patients with clinically suspected supraspinatus tendinopathy and no prior history of trauma referred for MRI of the shoulder were selected for this study. The supraspinatus tendinopathy was graded in consonance with MRI findings (Grade I, normal; Grade II, mild tendinopathy; Grade III, moderate tendinopathy; and Grade IV, marked tendinopathy). Strain ratios were evaluated. Spearman rank correlation test was used, to analyze the association of the MRI grade with strain ratios.

RESULTS:

Out of 25 patients, Grade I changes on MRI were found in 5 patients (20.0%), Grade II tendinopathy in 13 patients (52.0%), Grade III in 6 patients (24.0%), and Grade IV in 1 patient (4.0%). The mean sonoelastography strain ratio of supraspinatus tendons were 0.76 ± 0.32 in patients with Grade I, 0.59 ± 0.40 in Grade II, 0.31 ± 0.10 in Grade III and 0.15 ± 0.02 in Grade IV patients respectively. The strain ratios showed good correlation with the MRI grade p < 0.05.

CONCLUSION:

We compared the MRI findings of supraspinatus tendinopathy with sonoelastography strain ratios. Sonoelastography showed good correlation with MRI.

ADVANCES IN KNOWLEDGE:

Sonoelastography in supraspinatus tendinopathy may help in predicting improvement or worsening of the tendon health at the tissue level. Therefore, there is a possibility that it has use in the rehabilitation of professionals suffering from supraspinatus tendinopathy.

SUPRASPINATUS TENDON PATHOMECHANICS: A CURRENT CONCEPTS REVIEW

BACKGROUND AND PURPOSE

Tendinopathy of the supraspinatus muscle is a frequent cause of shoulder pain. Although it is a common condition, the pathophysiology is not fully understood. The purpose of this clinical commentary is to provide an overview of the pathophysiology of supraspinatus tendinopathy and discuss the conservative treatment solutions.

DESCRIPTION

Supraspinatus tendinopathy is thought to be caused by both intrinsic, and extrinsic factors. Structural and biological changes happen when tendinopathy develops. Cellular and extracellular modifications characterize tendon healing stages that continue over time. Assessment is paramount in order to differentiate the structure involved, and to offer a proper treatment solution.

RELATION TO CLINICAL PRACTICE

Knowledge of the general concepts regarding the development of supraspinatus tendinopathy, and of the healing process should guide physiotherapists when proposing treatment options. Physical modalities commonly utilized for supraspinatus tendinopathy such as: laser, ultrasound, and shock-wave therapy have little and contradictory evidence. Exercise in form of eccentric training may be considered as it seems to have beneficial effects, however, more research is needed.

Ultrasound-Guided Prolotherapy with Polydeoxyribonucleotide for Painful Rotator Cuff Tendinopathy

Background

Rotator cuff tendinopathy is a primary cause of shoulder pain and dysfunction. Several effective nonsurgical treatment methods have been described for chronic rotator cuff tendinopathy. Prolotherapy with polydeoxyribonucleotide (PDRN), which consists of active deoxyribonucleotide polymers that stimulate tissue repair, is a nonsurgical regenerative injection that may be a viable treatment option. The objective of this study was to assess the efficacy of PDRN in the treatment of chronic rotator cuff tendinopathy.

Method

The records of patients with chronic rotator cuff tendinopathy (n=131) were reviewed retrospectively, and the patients treated with PDRN prolotherapy (n=32) were selected. We measured the main outcome of the shoulder pain and disability index score on a numerical rating scale of average shoulder pain.

Results

Compared with baseline data, significant improvements in the shoulder pain and disability index and pain visual analog scale scores were demonstrated at one week after the end of treatment, and at one month and three months later.

Conclusions

PDRN prolotherapy may improve the conservative treatment of painful rotator cuff tendinopathy for a specific subset of patients.

Transtendon repair in partial articular supraspinatus tendon tear

INTRODUCTION

Partial thickness rotator cuff tears (PTRCTs) are common, with an incidence between 17% and 37%, and a high prevalence in throwing athletes. Different surgical procedures are suggested when partial tears involve the articular portion of the rotator cuff, including arthroscopic debridement of the tear, debridement with acromioplasty, tear completion and repair, and lately transtendon repair. This systematic review describes the transtendon repair and examines indications, contraindications, complications and clinical outcome.

SOURCE OF DATA

We identified clinical studies listed in the Pubmed Google Scholar, CINAHL, Cochrane Central and Embase Biomedical databases in English and Italian concerning the clinical outcomes following treatment of partial articular supraspinatus tendon tear using transtendon surgical repair.

AREAS OF AGREEMENT

Eighteen studies fulfilled our inclusion criteria. All were published between 2005 and 2016, three were retrospective, and 15 prospective. The total number of patients was 507 with a mean age of 50.8 years.

AREAS OF CONTROVERSY

Tear completion and repair and transtendon repair alone produce similar results.

GROWING POINTS

Transtendon surgical repair allows to obtain good-excellent results in the treatment of partial articular supraspinatus tendon tears.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies are needed to produce clear guidelines in the treatment of partial articular supraspinatus tendon tears.

LEVEL OF EVIDENCE

IV.

Effectiveness of Biologic Factors in Shoulder Disorders

Background:

Shoulder pathology can cause significant pain, discomfort, and loss of function that all interfere with activities of daily living and may lead to poor quality of life. Primary osteoarthritis and rotator cuff diseases with its sequalae are the main culprits. Management of shoulder disorders using biological factors gained an increasing interest over the last years. This interest reveals the need of effective treatments for shoulder degenerative disorders, and highlights the importance of a comprehensive and detailed understanding of the rapidly increasing knowledge in the field.

Methods:

This study will describe most of the available biology-based strategies that have been recently developed, focusing on their effectiveness in animal and clinical studies.

Results:

Data from in vitro work will also be briefly presented; in order to further elucidate newly acquired knowledge regarding mechanisms of tissue degeneration and repair that would probably drive translational work in the next decade. The role of platelet rich-plasma, growth factors, stem cells and other alternative treatments will be described in an evidence-based approach, in an attempt to provide guidelines for their clinical application. Finally, certain challenges that biologic treatments face today will be described as an initiative for future strategies.

Conclusion:

The application of different growth factors and mesenchymal stem cells appears as promising approaches for enhancing biologic repair. However, data from clinical studies are still limited, and future studies need to improve understanding of the repair process in cellular and molecular level and evaluate the effectiveness of biologic factors in the management of shoulder disorders.

Immunobiological factors aggravating the fatty infiltration on tendons and muscles in rotator cuff lesions

Rotator cuff lesions (RCLs) are a common cause of shoulder pain and dysfunction. The rotator cuff tendons can degenerate and/or tear from the greater tuberosity of the humerus, which is associated with several anatomical, physiological, biochemical, and molecular changes in tendon and muscle. In this article, these pathways are critically reviewed and discussed with various management strategies of RCLs. The article also highlights the immunobiological responses following the RCL and the inherent repair mechanisms elicited by the body. The greatest difficulty in treating this pathology is that the muscle can undergo irreversible fatty infiltration in the setting of chronic tears that is associated with poor surgical outcomes. The article also investigates the key molecular pathways of the muscle homeostasis (mTOR, Rho kinase, AMPK, and Ca(2+)) with the energy metabolism to propose a possible mechanism for fatty infiltration. Future research is warranted to target the key players of these pathways in the management of fatty infiltration and thus RCL.

Intratendinous rupture of the supraspinatus: anatomical and functional results of 24 operative cases

INTRODUCTION

The aim was to describe the natural history of intratendinous partial rotator cuff tears as well as the anatomical and clinical results of surgical treatment of a cohort of 24 patients.

PATIENTS AND METHODS

There were 14 men and 10 women with a mean age of 50 years. The right shoulder was involved in 17 cases. For 16 cases, a progressive history of shoulder pain was reported. Pre-operatively, a painful and positive Jobe's sign was observed in only 13 cases. Pre-operative mean absolute constant score was 63.52 points. Based on standard MRI, intratendinous lesions were diagnosed on the coronal view with hyper-signal within the tendon in the T2 FatSat sequence. No fatty infiltration was noted. Fourteen open and 10 arthroscopic repairs were performed.

RESULTS

Patients were reviewed with clinical assessment and MRI. The final Constant score was 81.3 points with a mean gain of 18.5 points. Patients were back to work after a mean of 5.8 months and to sports after 6 months. The mean subjective result was of 8.9/10. Three cases of reflex sympathetic dystrophy were observed.

DISCUSSION

Intratendinous tears of the supraspinatus tendon are rare and difficult to diagnose. Diagnosis relies on MRI (T2 FatSat). Trauma is not usually described. Chronic calcifying tendonitis may also contribute to the development of such tears. There is no associated fatty infiltration of the muscle. The Jobe's test is frequently painful or positive. Arthroscopic resection of the tendon insertion with reinsertion to the greater tuberosity seems to be the optimal treatment.

LEVEL OF EVIDENCE

Retrospective study, IV.

Current concepts of rotator cuff tendinopathy

PURPOSE/BACKGROUND

Tendinopathies are a broad topic that can be examined from the lab to their impact upon function. Improved understanding will serve to bring this pathology to the forefront of discussion, whether in the clinic or the classroom. The purpose of this current concepts clinical commentary is to explore intrinsic and extrinsic mechanisms of rotator cuff (RC) tendinopathy in order to improve clinical and research understanding.

METHODS

Pubmed, Medline, Cinahl, PEDro, and Cochrane databases were searched, limiting results to those published in the English language, between the years of 2005 and 2012. The key search terms utilized were intrinsic mechanisms, tendinopathy, stem cells, biologics, platelet-rich plasma (PRP), healing, rotator cuff tears, full-thickness tears, tests, impingement, imaging, ultrasound, Magnetic Resonance Imaging (MRI), radiograph, shoulder advances, treatment, diagnoses, tendon disorders, pathogenesis, matrix metalloproteinase, injections, and RC repair. Over 150 abstracts were reviewed and 43 articles were analyzed for quality and relevance using the University of Alberta Evidence Based Medicine Toolkit.

RESULTS/CONCLUSIONS

Current evidence suggests that tendinopathies arise from a multivariate etiology.It is increasingly evident that intrinsic mechanisms play a greater role than extrinsic mechanisms in this process. Emphasis should be placed on patient information (i.e. background information and personal description of symptoms) and imaging/ injection techniques in order to aid in diagnosis. Future treatment technologies such as cell therapy and biological engineering offer the hope of improving patient outcomes and quality of life.

LEVEL OF EVIDENCE

Level 5 - Clinical Commentary Related to a Review of Literature.

Clinics in diagnostic imaging. 148. Bursal-sided partial-thickness supraspinatus tendon tear

Rotator cuff injury comprises a continual spectrum of lesions ranging from tendinopathy, which may progress to partial- or full-thickness tear. This progression may be influenced by the interplay of extrinsic and intrinsic factors. We describe the case of a 29-year-man who presented with right shoulder pain for one year. His initial magnetic resonance (MR) arthrogram showed supraspinatus tendinopathy. Subsequent MR arthrogram, obtained after a road traffic accident, showed a bursal-sided partial-thickness tear of the supraspinatus tendon. In view of his worsening clinical symptoms, surgery was performed ten months later, revealing a full-thickness rotator cuff tear near the tendon insertion, with a tight subacromial space and bony protuberance of the humeral head. The pathogenesis of rotator cuff injuries, the roles of different imaging modalities in the diagnosis of rotator cuff injuries, as well as the advantages and limitations of various radiological modalities, are discussed.

Statistical methods for multivariate meta-analysis of diagnostic tests: An overview and tutorial

In this article, we present an overview and tutorial of statistical methods for meta-analysis of diagnostic tests under two scenarios: (1) when the reference test can be considered a gold standard and (2) when the reference test cannot be considered a gold standard. In the first scenario, we first review the conventional summary receiver operating characteristics approach and a bivariate approach using linear mixed models. Both approaches require direct calculations of study-specific sensitivities and specificities. We next discuss the hierarchical summary receiver operating characteristics curve approach for jointly modeling positivity criteria and accuracy parameters, and the bivariate generalized linear mixed models for jointly modeling sensitivities and specificities. We further discuss the trivariate generalized linear mixed models for jointly modeling prevalence, sensitivities and specificities, which allows us to assess the correlations among the three parameters. These approaches are based on the exact binomial distribution and thus do not require an ad hoc continuity correction. Lastly, we discuss a latent class random effects model for meta-analysis of diagnostic tests when the reference test itself is imperfect for the second scenario. A number of case studies with detailed annotated SAS code in MIXED and NLMIXED procedures are presented to facilitate the implementation of these approaches.