Hamstring Autograft versus Patellar Tendon Autograft for ACL Reconstruction: Is There a Difference in Graft Failure Rate? A Meta-analysis of 47,613 Patients

BACKGROUND

Bone-patellar tendon-bone (bone-tendon-bone) and four-strand hamstring tendon grafts (hamstring) are the most commonly utilized autografts for primary anterior cruciate ligament (ACL) reconstruction. Existing clinical trials, registry studies, and meta-analyses offer conflicting opinions regarding the most favorable graft choice.

QUESTIONS/PURPOSES

Which graft type for ACL reconstruction (bone-tendon-bone or hamstring) has a higher risk of (1) graft rupture and/or (2) graft laxity?

METHODS

We performed a meta-analysis of randomized controlled trials (RCTs), prospective cohort studies, and high-quality national registry studies to compare the outcomes of primary ACL reconstruction with bone-tendon-bone autograft or hamstring autograft. Studies that compared these graft types were identified through a comprehensive search of electronic databases (PubMed, MEDLINE, EMBASE, and the Cochrane Library). Two independent reviewers utilized the Jadad scale for RCT study quality and the Modified Coleman Methodology Score for prospective comparative and registry study quality. The included studies were analyzed for the primary outcome measure of graft rupture with or without revision ACL surgery. In surviving grafts, secondary outcomes of graft laxity were quantified by KT1000/2000™ testing, a positive pivot shift test, and a positive Lachman test. Meta-analysis was performed with Review Manager. A total of 47,613 ACL reconstructions (39,768 bone-tendon-bone and 7845 hamstring) from 14 RCTs, 10 prospective comparative studies, and one high-quality national registry study were included in this meta-analysis. Mean age was 28 years in both groups. Sixty-three percent of patients in the bone-tendon-bone cohort were men versus 57% of patients in the hamstring cohort. Mean followup was 68 ± 55 months.

RESULTS

Two hundred twelve of 7560 (2.80%) bone-tendon-bone grafts ruptured compared with 1123 of 39,510 (2.84%) in the hamstring group (odds ratio = 0.83, 95% confidence interval, 0.72-0.96; p = 0.01). The number needed to treat analysis found that 235 patients would need to be treated with a bone-tendon-bone graft over a hamstring tendon graft to prevent one graft rupture. Instrumented laxity analysis showed that 22% (318 of 1433) of patients in the bone-tendon-bone group had laxity compared with 18% (869 of 4783) in the hamstring tendon group (odds ratio = 0.86; p = 0.16). Pivot shift analysis showed a positive pivot shift in 19% (291 of 1508) of the bone-tendon-bone group compared with 17% (844 of 5062) in the hamstring group (odds ratio = 0.89; p = 0.51). Lachman testing showed a positive Lachman in 25% (71 of 280) of patients receiving bone-tendon-bone grafts compared with 25% (73 of 288) in the hamstring group (odds ratio = 0.96; p = 0.84).

CONCLUSIONS

In this meta-analysis of short- to mid-term followup after primary ACL reconstruction, hamstring autografts failed at a higher rate than bone-tendon-bone autografts. However, failure rates were low in each group, the difference observed was small, and we observed few differences between graft types in terms of laxity. Both graft types remain viable options for primary ACL reconstruction, and the difference in failure rate should be one part of a larger conversation with each individual patient about graft selection that should also include potential differences in donor site morbidity, complication rates, and patient-reported outcome measures. Continued prospective collection of patient data will be important going forward as we attempt to further characterize the potential differences in outcomes attributable to graft selection.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Comparative Outcomes of All-Inside Versus Inside-Out Repair of Bucket-Handle Meniscal Tears: A Propensity-Matched Analysis

Background:

There are limited data comparing the outcomes of all-inside versus inside-out meniscal repair techniques.

Purpose:

To assess failure rates and clinical outcomes after the surgical repair of bucket-handle meniscal tears utilizing either an all-inside or inside-out technique.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients with bucket-handle meniscal tears undergoing all-inside or inside-out repair at a single institution between 2003 and 2013 were analyzed. A total of 28 mensici repaired utilizing second-generation all-inside suturing devices and 42 menisci repaired using an inside-out technique were eligible for inclusion. Rigorous propensity matching was performed on the basis of age, sex, tear laterality, rim width, and concomitant anterior cruciate ligament reconstruction (ACLR), resulting in a total of 40 patients equally distributed between the 2 repair techniques for comparison. Retear-free survival as well as preoperative and postoperative International Knee Documentation Committee (IKDC) and Tegner scores and physical examination findings were subsequently analyzed.

Results:

Twenty patients who underwent all-inside repair (14 male; mean age, 23.7 ± 6.7 years) were successfully propensity matched to 20 patients who underwent inside-out meniscal repair (15 male; mean age, 22.5 ± 7.6 years), with a mean retear-free follow-up of 4.4 years (range, 2.5-7.4 years). Four (20%) all-inside repairs and 4 (20%) inside-out repairs failed over the course of follow-up (P > .999), with a mean time to failure of 2.7 years (range, 1.3-4.4 years) and 5.0 years (range, 0.8-7.5 years), respectively (P = .25). Increasing patient age trended toward a decreased clinical retear rate, independent of the repair technique (hazard ratio, 0.86; P = .056). There were no significant differences in the Tegner scores, IKDC scores, or range of motion between the groups as a whole or when subcategorizing by age, sex, body mass index, tear complexity, rim width, isolated versus concomitant ACLR, or medial- versus lateral-sided repair. There were no complications in the all-inside group, while there was a 10% rate of minor complications in the inside-out group (P = .49).

Conclusion:

Overall, satisfactory clinical outcomes are achievable at short-term to midterm follow-up with both inside-out and all-inside repair techniques of bucket-handle meniscal tears in rigorously matched patients with similar meniscal tear patterns.

What Are the Complications, Survival, and Outcomes After Revision to Reverse Shoulder Arthroplasty in Patients Older Than 80 Years?

BACKGROUND

By the time patients with a failed shoulder arthroplasty require revision surgery, a substantial number are older than 80 years. The risk of complications of revision arthroplasty in this elderly population is largely unknown and needs to be considered when contemplating whether these patients are too frail for revision surgery.

QUESTIONS/PURPOSES

(1) What are the 90-day medical and surgical complications after revision to reverse shoulder arthroplasty (RSA) in patients older than 80 years? (2) What are the 2- and 5-year survival rates after revision? (3) Was there an improvement in pain at rest or with activity, range of motion (ROM), and strength after revision surgery?

METHODS

Between 2004 and 2013, 38 patients who were older than 80 years (84 ± 3 years) underwent revision surgery to a RSA. Of those, five were lost to followup before 2 years, and two had died within 2 years of revision surgery, leaving 31 for analysis of our survivorship, pain, ROM, and strength endpoints at a minimum of 2 years or until revision surgery had occurred (mean, 28 months; range, 1-77 months); all 38 patients were included for purposes of evaluating medical and surgical complications at 90 days. During the period in question, our general indication for using RSA included failure of previous shoulder arthroplasty because of instability, glenoid loosening with bone loss, or rotator cuff insufficiency. The indication for revision to RSA did not change during the study period. The index procedure (revision to RSA at the age of 80 years or older) was the first revision arthroplasty in 33 (87%) patients and the second in five (13%) patients. We tallied 90-day medical and surgical complications by performing a retrospective chart and institutional joint registry review. The cumulative incidence of implant loosening (implant migration or tilting, or complete radiolucent lines present) and revision surgery was calculated at 2 and 5 years using competing risk of death method. Pain levels at rest or with activity (rated in a 1 to 5 Likert-type scale) were collected through a retrospective chart review and values before and after surgery were compared.

RESULTS

Medical complications occurred in three of 38 (8%) patients and surgical complications occurred in five of 38 (13%) patients. The 90-day mortality was 3% (one of 38 patients), and the total mortality was 26% (10 of 38 patients). The cumulative incidence of revision was 11% (95% CI, 0%-20%) at 2 years and 16% (95% CI, 1%-30%) at 5 years; the cumulative incidence of loosening was 8% (95% CI, 0%-20%) at 2 years and 16% (95% CI, 1%-30%) at 5 years. Pain at rest or with activity improved from pre- to postoperation (preoperative: median, 4 [range, 2-5]; postoperative: median, 1 [range, 1-4]; median difference: -2, 95% CI -3 to 0; p < 0.000). The active ROM improved during the preoperative compared with postoperative periods: mean ± SD forward flexion of 52° ± 40° to 109° ± 44°, respectively (mean difference: 56; 95% CI, 40-72; p < 0.000), and mean ± SD external rotation of 15° ± 22° to 31° ± 21°, respectively (mean difference: 16; 95% CI, 8-25; p < 0.000).

CONCLUSIONS

Age should not be used as a reason to not consider revision surgery to RSA in patients older than 80 years. Further studies with a prospective design, larger sample size, investigating risk factors for complications or poor outcome, and incorporation of functional scores are required.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Posterior Medial Meniscus Root Tears Potentiate the Effect of Increased Tibial Slope on Anterior Cruciate Ligament Graft Forces

BACKGROUND

Increased posterior tibial slope and posterior medial meniscus root tears increase the force experienced by the anterior cruciate ligament (ACL) and predispose patients to higher rates of primary ACL injury or ACL graft failure after an ACL reconstruction (ACLR). However, the interplay among sagittal plane tibial slope, medial meniscus root tears, and ACLR graft force remains inadequately defined.

PURPOSE/HYPOTHESIS

The purpose was to quantify the effect of sagittal plane tibial slope on ACLR graft force at varying knee flexion angles with an intact medial meniscus, a posterior medial meniscus root tear, and a medial meniscus root repair. Our null hypothesis was that changes in slope and meniscal state would have no effect on the forces experienced by the ACLR graft.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten male fresh-frozen cadaveric human knees underwent a posteriorly based high tibial osteotomy. A spanning external fixator and wedges of varying sizes were used to stabilize the osteotomy and allow for accurate slope adjustment. After ACLR, specimens were compressed with a 1000-N axial load at flexion angles of 0° and 30° for each of the 3 meniscal states and at tibial slopes of 0° to 15° at 3° increments. Graft loads were recorded through a force transducer clamped to the graft.

RESULTS

Increasing tibial slope led to a linear increase in ACLR graft force at 0° and 30° of knee flexion. Posterior medial meniscus root tear led to significant increases in ACLR graft forces over the intact state, while root repair restored the function of the medial meniscus as a secondary stabilizer. At 30° of knee flexion, the tibial slope effect on ACLR graft force was potentiated in the root tear state as compared with the intact and root repair states-test of interaction effect: t(139) = 2.67 (P = .009).

CONCLUSION

Increases in tibial slope lead to a linear increase in ACLR graft forces, and this effect is magnified in the setting of a posterior medial meniscus root tear. At slopes >12°, a slope-changing osteotomy could be considered in the setting of a revision ACLR with a concomitant medial meniscus root tear.

CLINICAL RELEVANCE

Defining the relationship between tibial slope and varying states of meniscal insufficiency can help determine when it may be necessary to perform a slope-decreasing proximal tibial osteotomy before ACLR and meniscal repair.

Increased posterior tibial slope results in increased incidence of posterior lateral meniscal root tears in ACL reconstruction patients

PURPOSE

While the association with acute anterior cruciate ligament (ACL) tears has been established, other risk factors and associated pathologies which occur with a concomitant lateral meniscal posterior root tear (LMPRT) are not well defined. The purpose of this study was to compare the risk factors and concomitant pathologies between patients with LMPRT and patients without LMPRTs in the setting of a primary ACL tear.

METHODS

Patients with a LMPRT identified at the time of primary ACL reconstruction by a single surgeon were identified. These patients were matched by age and sex to patients undergoing primary ACL reconstruction who were not found to have lateral meniscus root tears (control group) in a 1:1 ratio. Lateral posterior tibial slope (PTS), medial PTS, lateral femoral condyle height and depth, lateral tibial plateau depth, and lateral tibial plateau subluxation were measured on MRI. Anteroposterior full-limb alignment radiographs were used to measure the medial proximal tibia angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical weightbearing axis for the injured extremity.

RESULTS

One-hundred three patients were included in both the LMPRT group and the matched control group. Patients with a LMPRT had a significantly steeper lateral PTS (9.1° vs. 7.0°, p = 0.001), a steeper medial PTS (7.0° vs. 6.0°, p = 0.03), and a greater lateral-to-medial slope asymmetry (2.0° vs. 1.0°, p = 0.001). There were no differences in lateral femoral condyle depth or height, lateral tibial plateau depth, lateral tibial plateau subluxation, MPTA, mLDFA, or mechanical weightbearing axis between groups. There was a significantly increased incidence of medial meniscus ramp lesions in patients with lateral meniscus posterior root tears compared with controls (34.0% vs. 15.5%, odds ratio: 2.8, p = 0.002). There were no associations with concomitant ligament injuries, medial meniscus root tears, or non-ramp tears based on case/control grouping.

CONCLUSION

In conclusion, LMPRTs in the setting of primary ACL injuries were associated with significantly increased lateral and medial PTSs, and increased asymmetry between lateral and medial PTSs. In addition, clinicians should be aware of the increased incidence of concurrent medial meniscal ramp lesions in patients with LMPRTs. Knowledge of these associations helps guide clinical decision-making and counselling of patients in the setting of ACL tears with concomitant LMPRTs.

LEVEL OF EVIDENCE

IV.

Complications and implant survivorship following primary reverse total shoulder arthroplasty in patients younger than 65 years: a systematic review

BACKGROUND

Concerns exist regarding the complication rates and implant survivorship of reverse total shoulder arthroplasty (RTSA) in younger patients.

METHODS

A systematic review of the literature regarding the existing evidence on RTSA in patients younger than 65 years was performed using the CENTRAL (Cochrane Central Register of Controlled Trials), PubMed, and Embase databases on June 9, 2019. Articles published between 1995 and 2019 with combinations of the following keywords were identified: "reverse shoulder arthroplasty" and "65," "60," and/or "55." Complications, reoperations, and revisions were recorded. Reoperation-free survival and implant survival rates were grouped at 2, 5, and 10 years. Range of motion and clinical outcomes, along with postoperative radiographic results, were recorded.

RESULTS

Data from 7 studies with a total of 286 shoulders were obtained for quantitative analysis. The mean patient age was 58.4 years (mean age range, 48.9-60.4 years), and the mean follow-up period was 4.7 years (mean follow-up range, 3.0-7.8 years). The overall rate of complications was 18.6%; reoperations, 14.4%; and revisions, 11.2%. The reoperation-free survival rate was 97% at 2 years, 88%-90% at 5 years, and 76% at 10 years. The implant survival rate was 99% at 2 years, 91%-98% at 5 years, and 88% at 10 years. Active abduction, forward elevation, and external rotation significantly improved from preoperatively to postoperatively. All clinical outcome measures significantly improved from preoperatively to postoperatively, with no decline seen over time. The overall rate of infrascapular notching was 22.7% at final follow-up.

CONCLUSION

RTSA is safe and effective in patients younger than 65 years. Complication, reoperation, and revision rates were similar to those seen in older patient cohorts, without an increase in revisions owing to aseptic loosening. Clinical outcome scores showed significant and lasting improvements.

Emerging multidrug resistance of methicillin-resistant Staphylococcus aureus in hand infections

BACKGROUND

Methicillin-resistant Staphylococcus aureus has been the most commonly identified pathogen in hand infections at urban centers, but the evolving antibiotic sensitivity profiles of methicillin-resistant Staphylococcus aureus are not known. The purposes of this study are to determine if multidrug resistance in methicillin-resistant Staphylococcus aureus is emerging and to provide current recommendations for empiric antibiotic selection for hand infections in endemic regions.

METHODS

An eight-year longitudinal, retrospective chart review was performed on all culture-positive hand infections encountered by an urban hospital from 2005 to 2012. The proportions of all major organisms were calculated for each year. Methicillin-resistant Staphylococcus aureus infections were additionally analyzed for antibiotic sensitivity.

RESULTS

A total of 683 culture-positive hand infections were identified. Overall, methicillin-resistant Staphylococcus aureus grew on culture in 49% of cases; the annual incidence peaked at 65% in 2007. Over the study period, methicillin-resistant Staphylococcus aureus was universally resistant to penicillin, oxacillin, and ampicillin. Clindamycin resistance significantly increased, approaching 20% by 2012 (p = 0.02). Levofloxacin resistance linearly increased from 12% to 50% (p < 0.01). Resistance to trimethoprim-sulfamethoxazole, tetracycline, gentamicin, and moxifloxacin was only sporadically observed. Resistance to vancomycin, daptomycin, linezolid, and rifampin was not observed.

CONCLUSIONS

Significant increases in resistance to clindamycin and levofloxacin were observed in recent years, and empiric therapy with these drugs may have limited efficacy, especially in urban centers.

CLINICAL RELEVANCE

Hand infections caused by methicillin-resistant Staphylococcus aureus may be developing increasing resistance to clindamycin and levofloxacin in recent years. This longitudinal study examines the effectiveness of a variety of antibiotics to methicillin-resistant Staphylococcus aureus.

Primary reverse shoulder arthroplasty in patients older than 80 years of age

Aims

Reverse shoulder arthroplasty (RSA) reliably improves shoulder pain and function for a variety of indications. However, the safety and efficacy of RSA in elderly patients is largely unknown. The purpose of this study was to report the mortality, morbidity, complications, reoperations, and outcomes of primary RSA in patients aged > 80 years.

Patients and Methods

Between 2004 and 2013, 242 consecutive primary RSAs were performed in patients aged > 80 years (mean 83.3 years (sd 3.1)). Of these, 53 were lost to follow-up before two years and ten had died within two years of surgery, leaving 179 for analysis of survivorship, pain, motion, and strength at a minimum of two years or until revision surgery. All 242 patients were considered for the analysis of 90-day, one-year, and overall mortality, medical complications (90-day and overall), surgical complications, and reoperations. The indications for surgery included rotator cuff arthropathy, osteoarthritis, fracture, the sequela of trauma, avascular necrosis, and rheumatoid arthritis. A retrospective review of the medical records was performed to collect all variables. Survivorship free of revision surgery was calculated at two and five years.

Results

One patient (0.4%) died within the first 90 days. A total of 45 patients (19%) were known to have died at the time of the final follow-up, with a median time to death of 67.7 months (interquartile range 40.4 to 94.7) postoperatively. Medical complications occurred in six patients (3%) and surgical complications occurred in 21/179 patients (12%). Survivorship free from revision was 98.9% at two years and 98.3% at five years; survivorship free from loosening was 99.5% at final follow-up. The presence of peripheral vascular disease correlated with a higher complication rate.

Conclusion

Primary RSA was safe and effective in patients aged > 80 years, with a relatively low rate of medical and surgical complications. Thus, age alone should not be a contraindication to primary RSA in patients aged > 80 years. However, a careful evaluation of comorbidities is required in this age group when considering primary RSA. Cite this article: Bone Joint J 2019;101-B:1520–1525

Generational Differences in Grit, Self-Control, and Conscientiousness Among Orthopaedic Surgeons: From Millennials to Baby Boomers

BACKGROUND

The training process and practice of orthopaedic surgery is demanding and arduous. Accordingly, grit, self-control, and conscientiousness are desirable qualities in orthopaedic surgeons. Some established orthopaedists have expressed concern that the future generation of surgeons may not possess the same level of grit as their predecessors. The purpose of this study was to evaluate levels of grit among attending orthopaedic surgeons, identify predictors of grit in orthopaedic surgeons, and compare grit scores between attending surgeons and orthopaedic residency applicants. We hypothesized that applicants would demonstrate lower grit and self-control scores but greater conscientiousness scores than attending surgeons.

METHODS

A total of 2,342 attending orthopaedic surgeons and 895 orthopaedic residency applicants from the 2016-2017 National Resident Matching Program (NRMP) were given surveys that quantified their grit, self-control, and conscientiousness. Demographic and career information also was collected.

RESULTS

Assessments were completed by 655 (28%) of 2,342 practicing orthopaedic surgeons and 455 (50.8%) of 895 orthopaedic residency applicants. The residency applicants demonstrated higher mean grit scores (4.12 of 5.0) than the attending orthopaedic surgeons (4.03) (p < 0.01). These average scores placed applicants and attending surgeons at the 70th and 65th percentile, respectively, when compared with the general population. There were no differences in self-control (p = 0.68) or conscientiousness (p = 0.93) between the 2 groups. Attending surgeons with more publications had increased grit (p < 0.01), self-control (p = 0.04), and conscientiousness (p = 0.01) scores. Attending surgeons who had been inducted into the Alpha Omega Alpha honor society as medical students demonstrated greater conscientiousness scores than those who were not members (p = 0.04).

CONCLUSIONS

Orthopaedic residency applicants were at least as gritty, consistent in their interest, persevering in their efforts, and ambitious as currently practicing orthopaedic surgeons. Although these results may be encouraging and diverge from some preconceived perceptions of "millennials," it is unclear if they will be predictive of career success in the next generation of orthopaedists.

Multidirectional Shoulder Instability With Bone Loss and Prior Failed Latarjet Procedure: Treatment With Fresh Distal Tibial Allograft and Modified T-Plasty Open Capsular Shift

Recurrent multidirectional shoulder instability (MDI) is a challenging clinical problem, particularly in the setting of connective tissue diseases, and there is a distinct lack of literature discussing strategies for operative management of this unique patient group. These patients frequently present with significant glenoid bone loss, patulous and abnormal capsulolabral structures, and a history of multiple failed arthroscopic or open instability procedures. Although the precise treatment algorithm requires tailoring to the individual patient, we have shown successful outcomes in correcting recurrent MDI in the setting of underlying connective tissue disorders by means of a modified T-plasty capsular shift and rotator interval closure in conjunction with distal tibial allograft bony augmentation. The purpose of this Technical Note was to describe a technique that combines a fresh distal tibial allograft for glenoid bony augmentation with a modified T-plasty capsular shift and rotator interval closure for the management of recurrent shoulder MDI in patients presenting with Ehlers-Danlos syndrome or other connective tissue disorders after failed Latarjet stabilization.

Ruptured Spinal Aneurysms: Diagnosis and Management Paradigms

BACKGROUND

Spinal aneurysms (SA) are rare neurovascular pathologies with an unclear natural history and management strategy. We review the clinical and radiologic manifestations, management, and outcome of patients who presented with spinal subarachnoid hemorrhage (SAH) secondary to ruptured spinal aneurysms over a 10-year period. We provide a literature review about this condition and its management.

METHODS

All patients diagnosed with nontraumatic spinal SAH were collected from a single-center prospectively maintained database of patients with SAH between January 2010 and January 2020. Patients diagnosed with spinal aneurysms were reviewed. For each patient, demographic data, clinical presentation, imaging findings, management strategies, and outcomes are reviewed and discussed.

RESULTS

Between January 2010 and January 2020, ten patients were diagnosed with nontraumatic spinal SAH (3 patients presented with isolated spinal SAH and 7 patients with concomitant spinal and posterior fossa SAH). Among those, 4 patients were found to have a spinal aneurysm as the cause of SAH. The aneurysms were located in the cervical regions in 3 patients (75%) and at the thoracic level in 1 patient. Two aneurysms (50%) involved the anterior spinal artery, and 2 aneurysms (50%) involved a radiculomedullary artery. One aneurysm was a flow-related aneurysm of the anterior spinal artery in the setting of bilateral vertebral artery occlusion and was treated by surgical clipping with good outcome. Three aneurysms were idiopathic pseudoaneurysms with a negative diagnostic evaluation for secondary causes. These pseudoaneurysms were treated conservatively; 2 patients did well and 1 patient passed away from severe intracranial vasospasm. Two aneurysms resolved on diagnostic angiogram, and 1 aneurysm was absent on initial angiogram and appeared on follow-up diagnostic imaging 3 months later.

CONCLUSIONS

Spinal aneurysms are rare neurovascular pathologies that should be considered in the setting of spinal and/or posterior fossa subarachnoid hemorrhage. Conservative treatment may be a potential safe alternative to interventional treatment. Before the initiation of surgical or endovascular treatment, spinal angiography should be repeated because of the potential for spontaneous resolution.

Chronic Instability and Pain of the Sternoclavicular Joint: Treatment With Semitendinosus Allograft to Restore Joint Stability

Chronic instability of the sternoclavicular (SC) joint is a challenging clinical problem, particularly in a patient population for which nonoperative forms of treatment prove ineffective. Patients present after experiencing recurrent subluxation events and subsequent pain, which commonly result in increasing functional limitation. Recurrent SC joint instability of this nature can lead to damage of the SC joint cartilage and bone, and in cases of posterior subluxation or dislocation, damage to mediastinal structures. While the precise treatment algorithm requires tailoring to individual patients and their respective pathologies, we have demonstrated successful outcomes in correcting chronic SC joint instability by means of SC joint reconstruction with semitendinosus allograft, SC joint capsular reconstruction, and, in cases of arthritic damage, resection of a small portion of the degenerative component of the medial clavicle. The purpose of this Technical Note is to describe a technique that uses a semitendinosus allograft to stabilize the SC joint combined with a capsular reconstruction in patients who have previously failed nonoperative treatment methods.

Spectrophotometry in modular microfluidic architectures

Assays for chemical biomarkers are a vital component in the ecosystem of noninvasive disease state assessment, many of which rely on quantification by colorimetric reactions or spectrophotometry. While modern advances in microfluidic technology have enabled such classes of devices to be employed in medical applications, the challenge has persisted in adapting the necessary tooling and equipment to integrate spectrophotometry into a microfluidic workflow. Spectrophotometric measurements are common in biomarker assays because of straightforward acquisition, ease of developing the assay's mechanism of action, and ease of tuning sensitivity. In this work, 3D-printed, discrete microfluidic elements are leveraged to develop a model system for assaying hyaluronidase, a urinary biomarker of bladder cancer, via absorbance spectrometry of gold nanoparticle aggregation. Compared to laboratory microtiter plate-based techniques, the system demonstrates equivalent performance while remaining competitive in terms of resource and operation requirements and cost.