Concise Review: Bioprinting of Stem Cells for Transplantable Tissue Fabrication

Bioprinting is a quickly progressing technology, which holds the potential to generate replacement tissues and organs. Stem cells offer several advantages over differentiated cells for use as starting materials, including the potential for autologous tissue and differentiation into multiple cell lines. The three most commonly used stem cells are embryonic, induced pluripotent, and adult stem cells. Cells are combined with various natural and synthetic materials to form bioinks, which are used to fabricate scaffold‐based or scaffold‐free constructs. Computer aided design technology is combined with various bioprinting modalities including droplet‐, extrusion‐, or laser‐based bioprinting to create tissue constructs. Each bioink and modality has its own advantages and disadvantages. Various materials and techniques are combined to maximize the benefits. Researchers have been successful in bioprinting cartilage, bone, cardiac, nervous, liver, and vascular tissues. However, a major limitation to clinical translation is building large‐scale vascularized constructs. Many challenges must be overcome before this technology is used routinely in a clinical setting. Stem Cells Translational Medicine2017;6:1940–1948

Genetic Factors in Tendon Injury: A Systematic Review of the Literature

BACKGROUND

Tendon injury such as tendinopathy or rupture is common and has multiple etiologies, including both intrinsic and extrinsic factors. The genetic influence on susceptibility to tendon injury is not well understood.

PURPOSE

To analyze the published literature regarding genetic factors associated with tendon injury.

STUDY DESIGN

Systematic review; Level of evidence, 3.

METHODS

A systematic review of published literature was performed in concordance with the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) guidelines to identify current evidence for genetic predisposition to tendon injury. PubMed, Ovid, and ScienceDirect databases were searched. Studies were included for review if they specifically addressed genetic factors and tendon injuries in humans. Reviews, animal studies, or studies evaluating the influence of posttranscription factors and modifications (eg, proteins) were excluded.

RESULTS

Overall, 460 studies were available for initial review. After application of inclusion and exclusion criteria, 11 articles were ultimately included for qualitative synthesis. Upon screening of references of these 11 articles, an additional 15 studies were included in the final review, for a total of 26 studies. The genetic factors with the strongest evidence of association with tendon injury were those involving type V collagen A1, tenascin-C, matrix metalloproteinase-3, and estrogen-related receptor beta.

CONCLUSION

The published literature is limited to relatively homogenous populations, with only level 3 and level 4 data. Additional research is needed to make further conclusions about the genetic factors involved in tendon injury.

Research Pearls: The Significance of Statistics and Perils of Pooling. Part 3: Pearls and Pitfalls of Meta-analyses and Systematic Reviews

Within the health care environment, there has been a recent and appropriate trend towards emphasizing the value of care provision. Reduced cost and higher quality improve the value of care. Quality is a challenging, heterogeneous, variably defined concept. At the core of quality is the patient's outcome, quantified by a vast assortment of subjective and objective outcome measures. There has been a recent evolution towards evidence-based medicine in health care, clearly elucidating the role of high-quality evidence across groups of patients and studies. Synthetic studies, such as systematic reviews and meta-analyses, are at the top of the evidence-based medicine hierarchy. Thus, these investigations may be the best potential source of guiding diagnostic, therapeutic, prognostic, and economic medical decision making. Systematic reviews critically appraise and synthesize the best available evidence to provide a conclusion statement (a "take-home point") in response to a specific answerable clinical question. A meta-analysis uses statistical methods to quantitatively combine data from single studies. Meta-analyses should be performed with high methodological quality homogenous studies (Level I or II) or evidence randomized studies, to minimize confounding variable bias. When it is known that the literature is inadequate or a recent systematic review has already been performed with a demonstration of insufficient data, then a new systematic review does not add anything meaningful to the literature. PROSPERO registration and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines assist authors in the design and conduct of systematic reviews and should always be used. Complete transparency of the conduct of the review permits reproducibility and improves fidelity of the conclusions. Pooling of data from overly dissimilar investigations should be avoided. This particularly applies to Level IV evidence, that is, noncomparative investigations. With proper technique, systematic reviews and meta-analyses have the potential to be powerful investigations that efficiently assist clinicians in decision making.

Biomechanical Comparison of a First- and a Second-Generation All-Soft Suture Glenoid Anchor

Background:

All–soft tissue suture anchors provide advantages of decreased removal of bone and decreased glenoid volume occupied compared with traditional tap or screw-in suture anchors. Previous published data have led to biomechanical concerns with the use of first-generation all-soft suture anchors.

Purpose/Hypothesis:

The purpose of this study was to evaluate the load to 2-mm displacement and ultimate load to failure of a second-generation all-soft suture anchor, compared with a first-generation anchor and a traditional PEEK (polyether ether ketone) anchor. The null hypothesis was that the newer second-generation anchor will demonstrate no difference in loads to 2-mm displacement after cycling compared with first-generation all-soft suture anchors.

Study Design:

Controlled laboratory study.

Methods:

Twenty human cadaveric glenoids were utilized to create 97 total suture anchor sites, and 1 of 3 anchors were randomized and placed into each site: (1) first-generation all-soft suture anchor (Juggerknot; Biomet), (2) second-generation all-soft suture anchor (Suturefix; Smith & Nephew), and (3) a control PEEK anchor (Bioraptor; Smith & Nephew). After initial cyclic loading, load to 2 mm of displacement and ultimate load to failure were measured for each anchor.

Results:

After cyclic loading, the load to 2-mm displacement was significantly less in first-generation anchors compared with controls (P < .01). However, the load to 2-mm displacement was significantly greater in second-generation anchors compared with controls (P < .01). There was no difference in ultimate load to failure between the first- and second-generation all-soft suture anchors (P > .05).

Conclusion:

The newer generation all-soft suture anchors with a theoretically more rigid construct and deployment configuration demonstrate biomechanical characteristics (specifically, with load to 2-mm displacement after cyclic loading) that are improved over first-generation all-soft suture anchors and similar to a traditional solid tap-in anchor. The configuration of these newer generation all-soft suture anchors appears to mitigate the biomechanical concerns of decreased load to failure with first-generation all–soft tissue suture anchors.

Clinical Relevance:

The theoretical advantages of all-soft anchors may be particularly valuable in revision surgery or in cases where multiple anchors are being placed into a small anatomic area.

Bioprinting of osteochondral tissues: A perspective on current gaps and future trends

Osteochondral tissue regeneration has remained a critical challenge in orthopaedic surgery, especially due to complications of arthritic degeneration arising out of mechanical dislocations of joints. The common gold standard of autografting has several limitations in presenting tissue engineering strategies to solve the unmet clinical need. However, due to the complexity of joint anatomy, and tissue heterogeneity at the interface, the conventional tissue engineering strategies have certain limitations. The advent of bioprinting has now provided new opportunities for osteochondral tissue engineering. Bioprinting can uniquely mimic the heterogeneous cellular composition and anisotropic extra-cellular matrix (ECM) organization, while allowing for targeted gene delivery to achieve heterotypic differentiation. In this perspective, we discuss the current advances made towards bioprinting of composite osteochondral tissues and present an account of challenges-in terms of tissue integration, long-term survival, and mechanical strength at the time of implantation-required to be addressed for effective clinical translation of bioprinted tissues. Finally, we highlight some of the future trends related to osteochondral bioprinting with the hope of in-clinical translation.

Effect of Patellar Tunnel Placement on Fracture Risk after MPFL Reconstruction- A Cadaveric Study

Objectives:

Patella fracture is a rare complication after medial patellofemoral ligament (MPFL) reconstruction. Though many of the cases in the literature have been precipitated by trauma, the surgical factors that may lead to a higher risk of fracture are not well understood. The purpose of our study was to determine if transosseous tunnels that exit through the anterior cortex of the patella, and transverse bone tunnels have lower tensile load to failure as compared to control, and may predispose to post-operative patellar fracture.

Methods:

Fresh-frozen cadaveric human patellas were randomized to one of three groups: a control group with unmodified intact patellas, a group with two transverse tunnels (TT) drilled in the superior third of the patella that did not violate the anterior cortex, and a group with two transversetunnels that breach anterior cortex of the patella (PA). Patellas were connected to a freeze clamp mechanism via the remaining quadriceps and patellar tendons. A load cell was connected in series with the quadriceps clamp to measure maximum load to failure with a maximum load of 9000N. The angle of pull was fixed at 45 degrees, with the patella set in the trochlear groove of a composite synthetic femur. Patellas were cyclically loaded to 500 N for a total of 100 cycles. Specimens that did not fail during cyclic loading were then loaded to failure defined as fracture or tendon rupture. At failure, fluoroscopy was used to confirm a fracture if present and maximum load was recorded. The mean and standard deviation (STD) for each group were recorded. ANOVA and Student-T tests were used to identify significant differences between groups.

Results:

A total of 26 patellas were randomized and tested in this study. There were 12 male and 14 female patellas ranging in age from 37-95 years. There was no significant difference in the average age among the groups (Mean = 71.4 years, STD = 11.5 years, P =0.96). None of the patellas failed during cyclic loading alone. Control, TT and PA groups failed at 1915 N (STD= 508N), 1901 N (STD= 884N), and 1640 N (STD= 625N) respectively. This represents a 14% difference in means between Control and PA and Control and TT tunnels. There was no statistically significant difference between control and TT (p=.969), control and PA (p=.321), and TT and PA (p=.488). Subset analysis of fractures only through bone tunnels did not affect the significance.

Conclusion:

Our results show that breeching of the anterior cortex and transosseous tunnels that do not breach the anterior cortex during MPFL reconstruction do not significantly decrease the load to failure when compared to native patellas and, thus, may not pose an increased risk for patellar fracture. Further research is needed to analyze if other surgical factors may predispose to this complication.

Patient Outcomes as a Function of Shoulder Surgeon Volume: A Systematic Review

PURPOSE

To examine surgical complications, length of stay, surgical time, cost, revision rates, clinical outcomes, current surgical trends. and minimum number of cases in relationship to surgeon volume for shoulder arthroplasty and rotator cuff repair.

METHODS

We performed a systematic review of studies using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All studies that met inclusion criteria from January 1990 to January 2016 were included. Inclusion criteria included Level IV evidence or greater, contained specific surgeon volume, and were written in or translated into English. Exclusion criteria included non-English manuscripts, abstracts, and review papers. A written protocol was used to extract relevant data and evaluate study results. Data extracted included volume-specific data pertaining to length of stay, operating time, complications, and cost.

RESULTS

A total of 10 studies were included. Seven studies evaluated arthroplasty with 88,740 shoulders, and 3 studies evaluated rotator cuff repair with 63,535 shoulders. Variation was seen in how studies defined low- versus high-volume surgeon. For arthroplasty, <5 cases per year met the criteria for a low-volume surgeon and were associated with increased length of stay, longer operating room time, increased in-hospital complications, and increased cost. Mortality was not significantly increased. In rotator cuff surgery, <12 surgeries per year met the criteria for low volume and were associated with increased length of stay, increased operating room time, and increase in reoperation rate.

CONCLUSIONS

Our systematic review demonstrates increased surgical complications, length of stay, surgical time, and surgical cost in shoulder arthroplasty and rotator cuff repair when performed by a low-volume shoulder surgeon, which is defined by those performing <5 arthroplasties and/or <12 rotator cuff repairs per year.

LEVEL OF EVIDENCE

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

Trends in Surgical Management of Shoulder Instability

Background:

Optimal surgical management of anterior shoulder instability remains controversial. There is a need to assess the most recent trends for primary and revision shoulder stabilization surgery using a national database significantly larger than those previously utilized.

Hypothesis:

Most shoulder stabilization procedures are performed arthroscopically. Examining revision procedures, we hypothesized that open procedures would result in decreased revision stabilizations compared with arthroscopic procedures and that most revision procedures would be open Bankart or bone transfer procedures regardless of the index procedure technique.

Study Design:

Descriptive epidemiology study.

Methods:

The MarketScan Database was searched using International Classification of Diseases–Ninth Revision (ICD-9) and Current Procedural Terminology (CPT) codes to identify patients who underwent any shoulder stabilization procedure between 2008 and 2012. Regression analysis was used to evaluate trends between patient groups. The Cochran-Armitage trend test was used to identify differences in trends seen yearly. Odds ratios (ORs) were calculated to compare the likelihood of undergoing a revision stabilization procedure.

Results:

A total of 66,564 shoulder stabilization procedures were identified from 2008 through 2012: 60,248 arthroscopic stabilization procedures (90.5%) and 6316 open stabilization procedures (9.5%), including 1623 bone block procedures. Arthroscopic stabilization procedures increased in total number and percentage of all procedures in each year of the study. Bone block procedures increased in number each year, although other open procedures decreased during the study period. Males underwent more stabilization procedures, while patients between the ages of 10 and 19 years were most likely to undergo any procedure. Patients who underwent bone block stabilization were significantly less likely to undergo a second stabilization procedure during the study period when compared with open Bankart repair (OR, 0.582; 95% CI, 0.405-0.836; P < .05) and arthroscopic Bankart repair (OR, 0.587; 95% CI, 0.418-0.824; P < .05). No statistically significant difference in revision stabilization was seen when comparing arthroscopic versus open Bankart repair (OR, 0.934; 95% CI, 0.863-1.139).

Conclusion:

Although the number of arthroscopic shoulder stabilization surgeries continues to increase, our data show a consistent increase, not seen in prior studies, in the number of bone block procedures. Contrary to some studies, there was no significant difference in the likelihood of a second procedure between patients initially undergoing arthroscopic compared with open Bankart repair.

Research Pearls: The Significance of Statistics and Perils of Pooling

A series of articles on statistics are intended for an audience of clinicians, as well as statisticians and authors. Statistical significance is different than clinical significance. Understanding of clinical outcomes, value, quality, or generalizability requires critical analysis of medical research literature to ensure that statistical analyses have been properly applied and interpreted.

Research Pearls: The Significance of Statistics and Perils of Pooling. Part 1: Clinical Versus Statistical Significance

Patient-reported outcomes (PROs) are increasingly being used in today's rapidly evolving health care environment. The value of care provision emphasizes the highest quality of care at the lowest cost. Quality is in the eye of the beholder, with different stakeholders prioritizing different components of the value equation. At the center of the discussion are the patients and their quantification of outcome via PROs. There are hundreds of different PRO questionnaires that may ascertain an individual's overall general health, quality of life, activity level, or determine a body part-, joint-, or disease-specific outcome. As providers and patients increasingly measure outcomes, there exists greater potential to identify significant differences across time points due to an intervention. In other words, if you compare groups enough, you are bound to eventually detect a significant difference. However, the characterization of significance is not purely dichotomous, as a statistically significant outcome may not be clinically relevant. Statistical significance is the direct result of a mathematical equation, irrelevant to the patient experience. In clinical research, despite detecting statistically significant pre- and post-treatment differences, patients may or may not be able to perceive those differences. Thresholds exist to delineate whether those differences are clinically important or relevant to patients. PROs are unique, with distinct parameters of clinical importance for each outcome score. This review highlights the most common PROs in clinical research and discusses the salient pearls and pitfalls. In particular, it stresses the difference between statistical and clinical relevance and the concepts of minimal clinically important difference and patient acceptable symptom state. Researchers and clinicians should consider clinical importance in addition to statistical significance when interpreting and reporting investigation results.

Late cytomegalovirus infection in children: High incidence of allograft rejection and hepatitis in donor negative and seropositive liver transplant recipients

The complications and outcome associated with late CMV infection and disease on the graft are poorly characterized in PLT recipients. We studied the overall incidence, risk factors, and outcome of late CMV infection and disease (infection 6 months after transplant) in 180 PLT recipients admitted between 2008 and 2011 at the King's College Hospital. Antiviral prophylaxis of intravenous ganciclovir was given only to the D+R- group starting at day 7 post-transplant. The remaining groups (D-R+, D+R+, and D-R-) received pre-emptive therapy when they have CMV viremia above cut-off value and treatment for symptomatic CMV infection. The overall incidence of late CMV infection and disease was 9.4% (19/180) and 14.5% (19/130) in D+R-, D-R+, D+R- groups. The D-R+ group had the highest incidence of hepatitis (37.5%) and significantly increased incidence of CMV disease, and single and multiple acute rejection episodes when compared to the D+R- group, which received prophylaxis. The late CMV infection and disease in pediatric LT recipients was comparable to adult LT recipients despite variable duration of antiviral prophylaxis. Our results show that D-R+ group had highest rate of hepatitis and rejection episodes, associated with high morbidity, and should be considered for antiviral prophylaxis.

Reliability, Validity, and Injury Predictive Value of the Functional Movement Screen: A Systematic Review and Meta-analysis

BACKGROUND

The Functional Movement Screen (FMS) is utilized by professional and collegiate sports teams and the military for the prevention of musculoskeletal injuries.

HYPOTHESIS

The FMS demonstrates good interrater and intrarater reliability and validity and has predictive value for musculoskeletal injuries.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review and meta-analysis were conducted using a computerized search of the electronic databases MEDLINE and ScienceDirect in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Extracted relevant data from each included study were recorded on a standardized form. The Cochran Q statistic was utilized to evaluate study heterogeneity. Pooled quantitative synthesis was performed to measure the intraclass correlation coefficient (ICC) for interrater and intrarater reliability, along with 95% CIs, and odds ratios with 95% CIs for the injury predictive value for a score of ≤14.

RESULTS

Eleven studies for reliability, 5 studies for validity, and 9 studies for the injury predictive value were identified that met inclusion and exclusion criteria; of these, 6 studies for reliability and 9 studies for the injury predictive value were pooled for quantitative synthesis. The ICC for intrarater reliability was 0.81 (95% CI, 0.69-0.92) and for interrater reliability was 0.81 (95% CI, 0.70-0.92). The odds of sustaining an injury were 2.74 times with an FMS score of ≤14 (95% CI, 1.70-4.43). Studies for validity demonstrated flaws in both internal and external validity of the FMS.

CONCLUSION

The FMS has excellent interrater and intrarater reliability. Participants with composite scores of ≤14 had a significantly higher likelihood of an injury compared with those with higher scores, demonstrating the injury predictive value of the test. Significant concerns remain regarding the validity of the FMS.

Abstract P3-03-18: An ex-vivo platform predicts anti-tumor outcome of metabolically-targeted, algorithm-driven combination therapy in triple-negative breast cancer

Cancer cells undergo phenotypic cell state transitions in response to chemotherapy as a mechanism that can confer transient resistance. However, such cell state transitions can also unlock unique vulnerabilities that can be exploited using temporally-sequenced combination chemotherapy. Here, utilizing a primary breast cancer ex-vivo functional assay that captures tumor heterogeneity, we report that in response to a chemotherapeutic agent, a subset of cancer cells can mount an acutely-induced phenotypic adaptive resistance to future cytotoxic pressure via the transient acquisition of a unique metabolic state defined by augmented glycolysis together with mitochondrial proficiency. These cells activate two complex, temporally-interdependent pathways that enable a glucose shunt towards the pentose phosphate pathway (PPP), which confers an adaptive cross-tolerance to different chemotherapeutic agents. Mathematically modeling these pathways, and simulating drug schedules, we define a rationally-designed 3-drug combination therapy of metabolic inhibitors and cytotoxic agents, which results in improved cancer survival. Our findings highlight a new bioenergetics-based adaptive resistance mechanism through which cancer cells can survive combinations of chemotherapy. Administration of metabolic inhibitors in rational, temporal sequence with existing chemotherapy can emerge as a new paradigm in the treatment of cancer.

Citation Format: Goldman A, Majumder B, Dhawan A, Kohandel M, Majumder P, Sengupta S. An ex-vivo platform predicts anti-tumor outcome of metabolically-targeted, algorithm-driven combination therapy in triple-negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-03-18.

Editorial Commentary: The Jury Remains Out on Hybrid Autograft-Plus-Allograft for Diminutive Hamstring Anterior Cruciate Ligament Autografts

In a Level III, single center, retrospective, nonrandomized observational study, anterior cruciate ligament reconstruction revision rates and patient-reported outcomes were found to be similar at 2-year follow-up when using autograft hamstrings versus a hybrid graft (autograft and nonirradiated allograft), with both groups reporting low levels of revisions and excellent outcomes. Despite previous published data that were cause for concern, a study in this issue provides support for use of a hybrid graft technique when encountering the challenging situation of a diminutive hamstring autograft when performing anterior cruciate ligament reconstruction.

Acute Liver Failure Due to Adenoviral Hepatitis in a Pediatric Liver Transplant

Adenoviral infection is a significant cause of morbidity and mortality in immunocompromised patients in the pediatric age group, hepatitis caused by the serotype 5 being the most common manifestation in the liver transplant recipient. The authors report a case of a 3 1/2-year-old child in whom fatal adenoviral hepatitis developed after liver transplantation for syndromic paucity of the intrahepatic bile ducts. Allograft biopsy at 14 days showed early changes of microabscesses in the parenchyma but no inclusions. Immunohistochemistry using an adenovirus-group antibody (MAB805, Chemicon International, Harrow, England), however, demonstrated nuclear positivity in hepatocytes related to and at a distance from the lesions. As antibody titers are unreliable in an immunocompromised patient and culture results take time, immunohistochemistry for adenovirus offers a rapid diagnosis. The technique is economic and has a clear advantage on the more demanding electron microscopic screening, which was performed in the case as additional evidence. Immunohistochemistry for adenovirus should be done routinely in the presence of microabscesses to differentiate the lesion from hepatitis due to cytomegalovirus. Int J Surg Pathol 3(3) :189-194, 1996

Suture Anchor Biomechanics After Rotator Cuff Footprint Decortication

PURPOSE

To identify the biomechanical consequences of violating the cortical shelf when preparing the greater tuberosity for suture anchor repair.

METHODS

Demographic information and bone mineral density were obtained for 20 fresh-frozen human humeri (10 matched pairs). Suture anchors were placed at a predetermined location in decorticated and non-decorticated settings after randomization. Anchors were tested under cyclic loads followed by load-to-failure testing. The number of cycles, failure mode, stiffness, and final pullout strength were recorded.

RESULTS

Nineteen specimens met the inclusion criteria for final testing. A significant difference in mean ultimate load to failure was seen between the non-decorticated specimens (244.04 ± 89.06 N/mm) and the decorticated humeri (62.84 ± 38.04 N/mm, P < .0001). Regression analysis showed positive correlations with female gender and decreased bone mineral density (P = .008 and P = .0005, respectively).

CONCLUSIONS

Decortication of the rotator cuff footprint significantly decreases the pullout strength of the suture anchor. Gender and bone mineral density also play a significant role in bone-anchor biomechanics and should be considered during repair.

CLINICAL RELEVANCE

Caution should be exercised when preparing the rotator cuff footprint before suture anchor placement because of the significant risk of early repair failure at the bone-anchor interface.

Cartilage repair techniques in the knee: stem cell therapies

Among the surgical options for large full-thickness chondral injuries, cell-based therapy has been practiced and its satisfactory outcomes have been reported. One area that appears promising is cell-based therapies utilizing stem cells. Various tissues within the human body contain mesenchymal stem cells (MSCs) from where these can be harvested. These include bone marrow, adipose, synovium, peripheral blood, and umbilical cord. In this article, both preclinical animal studies and clinical studies dealing with the use of MSCs for cartilage repair of the knee are reviewed. Majority of the clinical papers have shown promising results; however, there are a limited number of studies of high evidence level. Clinical significance of the stem cell therapy as compared to other surgical options as well as optimization of the procedure in terms of cell type and delivery method is still to be determined.

Surgical treatment of symptomatic superior labrum anterior-posterior tears in patients older than 40 years: a systematic review

BACKGROUND

Successful arthroscopic repair of symptomatic superior labral tears in young athletes has been well documented. Superior labral repair in patients older than 40 years is controversial, with concerns for residual postoperative pain, stiffness, and higher rates of revision surgery.

PURPOSE

To analyze the published data on the surgical treatment of superior labral injuries in patients aged ≥40 years, including those with concomitant injuries to the rotator cuff.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of the literature was performed using the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The MEDLINE database via PubMed and the Cochrane Database of Systematic Reviews were searched for articles related to superior labrum anterior-posterior (SLAP) tears. Studies were included if they met the following criteria: the study contained at least 1 group of patients who had undergone arthroscopic repair of a type II or IV SLAP lesion with a minimum 2-year follow-up, objective and/or functional scoring systems were used to evaluate postoperative outcomes, and the mean patient age was ≥40 years for at least 1 treatment arm or subgroup analysis. Studies were excluded if the article was a review or if the article included data for SLAP type I, III, or V to X tears or Bankart lesions.

RESULTS

While several authors reported equivalent outcomes of SLAP repair in patients both older than 40 years and younger than 40 years, others demonstrated significantly higher failure rates in the older cohort. Decreased patient satisfaction and increasing complications, including postoperative stiffness and reoperations, occur at higher rates as the patient age increases. The literature demonstrates that biceps tenotomy and tenodesis are reliable alternatives to SLAP repair and that biceps tenotomy is a viable revision procedure for failed SLAP repair. With concomitant rotator cuff tears, the evidence favors debridement or biceps tenotomy over SLAP repair.

CONCLUSION

While studies show that good outcomes can be obtained with SLAP repair in an older cohort of patients, age older than 40 years and workers' compensation status are independent risk factors for increased surgical complications. The cumulative evidence supports labral debridement or biceps tenotomy over labral repair when an associated rotator cuff injury is present.

Quantifying the Economic Impact of Provider Volume Through Adverse Events: The Case of Sports Medicine

BACKGROUND

Procedures performed by surgeons with higher provider volumes offer advantages both to the individual patient and the health system, with studies documenting fewer adverse events, shorter surgical times, and decreased reoperation rates. With workforce requirements for surgeons growing, it is increasingly necessary to establish the most efficient structure of this workforce.

HYPOTHESIS

Substantial economic savings are realized when procedures are performed by high-volume providers as compared with low-volume providers in the areas of readmission, prolonged admission, and subsequent surgery.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 2.

METHODS

This study utilized decision modeling to estimate the cost savings to high-volume providers in sports medicine. Simple decision models were constructed for 3 common procedures: anterior cruciate ligament (ACL) reconstruction, rotator cuff repair, and total shoulder arthroplasty. Outcome probabilities for adverse events (readmission, prolonged admission, and subsequent surgery) and costs were taken from the literature. A Monte Carlo simulation reflecting the incidence of these procedures in the United States was performed to estimate the total nationwide cost of these procedures, and the impact of both negative and positive policies on this cost were examined using sensitivity analysis.

RESULTS

The costs per case attributable to adverse outcomes for ACL reconstruction (in 2010 US$) were $496, $781, and $868 for high-, medium-, and low-volume providers, respectively. For rotator cuff repair, these numbers were $523, $640, and $872, and for total shoulder arthroplasty, $1692, $1876, and $2021, respectively. Sensitivity analysis revealed that a 50% increase in the number of these 3 procedures performed by high-volume surgeons could save the health system $23.1 million. If all procedures were performed by high-volume surgeons, the health system could save $72 million.

CONCLUSION

The hypothesis was accepted; higher provider volumes for surgeons do convey substantial societal economic benefits. Policies to incentivize and facilitate a greater portion of procedures being performed by high-volume surgeons may increase the efficiency of resource utilization in health care delivery.

Efficacy of dose escalation on TCP, recurrence and second cancer risks: a mathematical study

OBJECTIVE

We investigated the effects of conventional and hypofractionation protocols by modelling tumour control probability (TCP) and tumour recurrence time, and examined their impact on second cancer risks. The main objectives of this study include the following: (a) incorporate tumour recurrence time and second cancer risks into the TCP framework and analyse the effects of variable doses and (b) investigate an efficient protocol to reduce the risk of a secondary malignancy while maximizing disease-free survival and tumour control.

METHODS

A generalized mathematical formalism was developed that incorporated recurrence and second cancer risk models into the TCP dynamics.

RESULTS

Our results suggest that TCP and relapse time are almost identical for conventional and hypofractionated regimens; however, second cancer risks resulting from hypofractionation were reduced by 22% when compared with the second cancer risk associated with a conventional protocol. The hypofractionated regimen appears to be sensitive to dose escalation and the corresponding impact on tumour recurrence time and reduction in second cancer risks. The reduction in second cancer risks is approximately 20% when the dose is increased from 60 to 72 Gy in a hypofractionated protocol.

CONCLUSION

Our results suggest that hypofractionation may be a more efficient regimen in the context of TCP, relapse time and second cancer risks. Overall, our study demonstrates the importance of including a second cancer risk model in designing an efficient radiation regimen.

ADVANCES IN KNOWLEDGE

The impact of various fractionation protocols on TCP and relapse in conjunction with second cancer risks is an important clinical question that is as yet unexplored.