Self-powered, light-controlled, bioresorbable platforms for programmed drug delivery.

Degradable polymer matrices and porous scaffolds provide powerful mechanisms for passive, sustained release of drugs relevant to the treatment of a broad range of diseases and conditions. Growing interest is in active control of pharmacokinetics tailored to the needs of the patient via programmable engineering platforms that include power sources, delivery mechanisms, communication hardware, and associated electronics, most typically in forms that require surgical extraction after a period of use. Here we report a light-controlled, self-powered technology that bypasses key disadvantages of these systems, in an overall design that is bioresorbable. Programmability relies on the use of an external light source to illuminate an implanted, wavelength-sensitive phototransistor to trigger a short circuit in an electrochemical cell structure that includes a metal gate valve as its anode. Consequent electrochemical corrosion eliminates the gate, thereby opening an underlying reservoir to release a dose of drugs by passive diffusion into surrounding tissue. A wavelength-division multiplexing strategy allows release to be programmed from any one or any arbitrary combination of a collection of reservoirs built into an integrated device. Studies of various bioresorbable electrode materials define the key considerations and guide optimized choices in designs. In vivo demonstrations of programmed release of lidocaine adjacent the sciatic nerves in rat models illustrate the functionality in the context of pain management, an essential aspect of patient care that could benefit from the results presented here.

Better Radiographic Reduction and Lower Complication Rates With Combined Coracoclavicular and Acromioclavicular Ligament Reconstruction Than With Isolated Coracoclavicular Reconstruction.

PURPOSE: To determine whether combined acromioclavicular (AC) ligament reconstruction and coracoclavicular (CC) ligament reconstruction without bone tunnels would improve radiographic reduction maintenance and complication rates for type III to V AC dislocations. METHODS: This single-institution retrospective study analyzed all patients who underwent a hybrid synthetic/graft wrap CC reconstruction without tunnels with additional AC reconstruction/repair from January 2013 to August 2019. This 26-patient cohort was compared with a 1:1 sex- and age-matched control group who underwent CC reconstruction without AC reconstruction. CC distances on postoperative radiographs were compared with normal contralateral shoulders. RESULTS: Of the 93 patients who underwent AC reconstructive surgery during this time period, 26 patients (96% male) met the inclusion criteria. The AC/CC cohort had 23.5% type III injuries, 23.1% type IV injuries, and 53.8% type V injuries, similar to the control group. Final radiographs of the operative shoulder's CC distance were (mean ± standard deviation) 0.9 ± 4.0 mm greater than that of the contralateral shoulder (9.6 ± 8.7 mm) in the AC/CC cohort. Final radiographs of the operative shoulder's coracoclavicular distance were 4.0 ± 4.7 mm greater than that of the contralateral shoulder (13.3 ± 9.3 mm) in the CC control group, a significant difference (P = .014). The AC/CC reconstruction group had fewer patients with a loss of reduction >5 mm (11.5% versus 38.5%, P = .025). The complication rate in the CC control group was higher than in the AC/CC cohort (30.7% versus 7.7%, P = .035). The reoperation rate was also greater in the CC control group (8 versus 1, P = .010). CONCLUSION: This cohort study shows that the addition of AC reconstruction to CC reconstruction using synthetic tapes/grafts or allograft tissues without bone tunnels significantly improves durable radiographic outcomes, diminishes complication rates, and improves reoperation rates. LEVEL OF EVIDENCE: III, retrospective comparative study.

The relationship of bilateral shoulder arthroplasty timing and postoperative complications.

BACKGROUND: Though several case series have described bilateral shoulder arthroplasty results with range of motion, patient-reported outcomes, and complications, little guidance exists regarding the optimal interval timing between surgeries. METHODS: All patients from 2 insurance databases who underwent staged bilateral shoulder arthroplasty between 2005 and 2016 were identified. These patients were then stratified by elapsed time between surgeries into 4 study groups: (1) less than 3 months, (2) 3-6 months, (3) 6-9 months, and (4) 9-12 months. Surgical and perioperative medical complications of these patient cohorts were compared to a control group that underwent bilateral shoulder arthroplasty with a greater than 1-year interval between surgeries. RESULTS: From 2005-2016, a total of 1764 patients (6.3%) underwent bilateral shoulder arthroplasty out of 27,962 shoulder arthroplasties performed in the 2 databases. Of the bilateral patients, 49.1% waited more than 1 year before their second shoulder arthroplasty. Patients waiting less than 3 months between surgeries comprised 4.9% of the total number of staged bilateral surgeries. Demographics and comorbidities were similar between the study groups. Overall, implant complications were higher in patients with surgeries less than 3 months apart compared to controls, including revision arthroplasty (11.6% vs. 5.4%, odds ratio [OR] 2.29, P = .037), loosening/lysis (8.1% vs. 3.5%, OR 2.46, P = .032), and periprosthetic fracture (4.7% vs. 1.2%, OR 4.18, P = .010). There were no significant increases in any implant-related complications when surgeries were staged by 3 months or more compared to controls. Venous thromboembolism (VTE; 8.1% vs. 2.2%, OR 3.95, P = .001) and blood transfusion (9.3% vs. 1.7%, OR 5.82, P < .001) occurred at a significantly higher rate in patients with less than 3 months between surgeries compared with controls. There were no differences in any medical complications when surgeries were staged by 3 months or more compared with controls. CONCLUSIONS: Patients with staged bilateral shoulder arthroplasty who have the second arthroplasty within 3 months have significantly higher rates of revision surgery, loosening/lysis, periprosthetic fracture, VTE, and blood transfusions. Based on these lower complication rates, surgeons should consider waiting a minimum of 3 months before performing the second portion of a staged bilateral shoulder arthroplasty.

High-Energy Proximal Humerus Fractures in Geriatric Patients: A Review.

High-energy proximal humerus fractures in elderly patients can occur through a variety of mechanisms, with falls and MVCs being common mechanisms of injury in this age group. Even classically low-energy mechanisms can result in elevated ISS scores, which are associated with higher mortality in both falls and MVCs. These injuries result in proximal humerus fractures which are commonly communicated via Neer's classification scheme. There are many treatment options in the armamentarium of the treating surgeon. Nonoperative management is widely supported by systematic review as compared to almost all other treatment methods. ORIF is particularly useful for complex patterns and fracture dislocations in healthy patients. Hemiarthroplasty can be of utility in patients with fracture patterns with high risk of AVN and poor bone quality risking screw cut-out. Reverse total shoulder arthroplasty is a popular method of treatment for geriatric patients also, with literature now showing that even late conversion from nonoperative management or ORIF to rTSA can lead to good clinical outcomes. Prevention is possible and important for geriatric patients. Optimizing medical care including hearing, vision, strength, and bone quality, in coordination with primary care and geriatricians, is of great importance in preventing fractures and decreasing injury when falls do occur. Involving geriatricians on dedicated trauma teams will also likely be of benefit.

The effect of current and former tobacco use on outcomes after primary reverse total shoulder arthroplasty.

BACKGROUND: The purpose of this study was to determine the influence of current and former tobacco use on minimum 2-year clinical and radiographic outcomes after reverse total shoulder arthroplasty (RTSA). METHODS: Review of primary RTSA patient data identified 186 patients with at least 2 years of follow-up. Patients were classified as nonsmokers (76 patients), former smokers (89 patients), or current smokers (21 patients). Assessment included preoperative and postoperative visual analog scale pain scores, American Shoulder and Elbow Surgeons scores, strength, range of motion, complications, revisions, and narcotic use. Radiographs were analyzed for signs of loosening or mechanical failure. RESULTS: Overall mean age of the patients was 70 (48-87) years, and mean follow-up was 2.6 (2.0-5.7) years. Smokers (62.1 years) were significantly younger than nonsmokers (70.7 years) and former smokers (70.8 years; P = .00002). All patients had significant improvements in pain, American Shoulder and Elbow Surgeons score, strength, and forward flexion range of motion; however, smokers had higher visual analog scale pain scores (mean, 2.5) than nonsmokers (mean, 1.8) or former smokers (mean, 1.0; P = .014). Otherwise, no differences were found regarding any of the postoperative parameters (P > .05). CONCLUSIONS: Aside from increased patient-reported pain, current tobacco use does not appear to negatively affect outcomes after primary RTSA. The RTSA design obviates the need for a functioning rotator cuff, possibly mitigating tobacco's negative effects previously demonstrated in rotator cuff repair and anatomic total shoulder arthroplasty. Former users obtained outcomes similar to those of nonusers, suggesting that tobacco use is a modifiable risk factor to achieve optimal pain relief after RTSA.

Bundled Payment Plans Are Associated With Notable Cost Savings for Ambulatory Outpatient Total Shoulder Arthroplasty.

INTRODUCTION: Bundling of services, typically into a 90-day episode of care, is intended to facilitate cost reduction. The purpose of this study was to determine the impact of a private insurance bundling program on the costs of outpatient total shoulder arthroplasty (TSA) at a freestanding ambulatory surgery center. METHODS: A cost minimization analysis was done of patients who had anatomic TSA by a single surgeon at a single freestanding ambulatory surgery center, including line-by-line comparisons of demographic and comorbidity factors for all patients treated within the 90-day episode of care. RESULTS: Seventy-six primary anatomic TSAs were included, 39 in the bundled group and 37 outside of the program. The bundled group was on average older (58 years) than the unbundled group (54 years, P = 0.021), but the groups were otherwise similar in demographics. The average total implant charges were significantly less for the bundled group ($24,822.43 versus $28,405.51, P = 0.014). Average total surgery supply charges and anesthesia supply charges were similar (P > 0.05). Mean total outpatient surgical day charges (implants, surgical, and anesthesia equipment) were significantly less for the bundled group ($29,782.43 versus $33,238.68, P = 0.022), as were average operating room staffing costs ($135.37 versus $162.55, P = 0.015). During the 90-day postoperative period, charges were similar. CONCLUSIONS: Primary anatomic TSA using a bundled care program in an outpatient setting coincides with markedly lower charges. The primary driver of this reduction is implant pricing, which is negotiated as part of the bundle. Surgeons must carefully analyze their unique practices in the changing economic health care environment when creating an outpatient TSA and/or bundling program. LEVEL OF EVIDENCE: Level III economic analysis.

Safety and Cost-Effectiveness of Outpatient Unicompartmental Knee Arthroplasty in the Ambulatory Surgery Center: A Matched Cohort Study.

Using an age- and comorbidity-matched cohort, we compared patients who underwent unicompartmental knee arthroplasty in an ambulatory surgery center with those who underwent the procedure in a traditional hospital inpatient setting. Postoperatively, the ambulatory surgery center cohort had fewer major complications than the inpatient cohort. No ambulatory surgery center patients required acute hospital admission and none had major complications. Four major complications occurred in the inpatient cohort. There was no difference in complication rates. Our results suggest that outpatient unicompartmental knee arthroplasty in a freestanding ambulatory surgery center is a safe and reasonable alternative to the traditional inpatient hospital setting.

Outcomes of Uncemented Versus Cemented Reverse Shoulder Arthroplasty for Proximal Humerus Fractures.

Reverse shoulder arthroplasty (RSA) for proximal humerus fractures (PHFs) is traditionally performed with cemented humeral fixation. The purpose of this study was to compare the clinical and radiographic outcomes of cemented and cementless RSA for PHF. Between 2010 and 2014, 38 acute PHFs were treated with RSA and followed for a minimum of 2 years (mean, 37 months; range, 24-66 months). The mean time from fracture to RSA was 7 days (range, 1-30 days). Humeral stems were cemented in 19 shoulders and uncemented in 19 shoulders. Outcome measures included visual analog scale pain scores, range of motion, postoperative Quick Disabilities of the Arm, Shoulder and Hand scores, American Shoulder and Elbow Surgeons scores, and radiographic parameters. The 2 groups had similar visual analog scale pain scores, postoperative range of motion, and Quick Disabilities of the Arm, Shoulder and Hand scores (P>.05). American Shoulder and Elbow Surgeons scores and satisfaction scores were significantly higher with cemented humeral fixation (76.3 vs 48.0, P=.005; 1.2 vs 1.8, P=.04). Radiographically, there was no difference in terms of tuberosity healing, component loosening, or notching (P>.05). Reverse shoulder arthroplasty provides pain relief for PHF, regardless of humeral fixation. In this cohort, cementless fixation was associated with worse patient-reported outcomes, although no correlation could be established with pain, motion, or tuberosity healing. Further studies are required before cementless fixation can be recommended for RSA for fracture. [Orthopedics. 2019; 42(2):e236-e241.].

Younger patients report similar activity levels to older patients after reverse total shoulder arthroplasty.

BACKGROUND: Younger patients who have undergone reverse total shoulder arthroplasty (RTSA) are believed to have higher activity levels that place higher stresses across the prosthesis, increasing the risk of failure, but there is little information to support or refute this supposition. The purposes of this study were to define the patient-reported activity levels of patients younger than 65 years and older than 65 years who underwent RTSA and to evaluate any differences between the groups. METHODS: Forty-six patients who underwent primary RTSA answered a questionnaire regarding their activity levels. Data were categorized and tabulated according to pain, range of motion, strength, and activity level (low, medium, and high demand). Statistical analyses were performed using the Fisher exact test, χ(2) test, and independent t test. Differences with P < .05 were considered statistically significant. RESULTS: Seventeen patients younger than 65 years (mean age, 57.7 years) and 29 patients older than 65 years (mean age, 75.2 years) were included. No significant differences were found for range of motion, strength, or number of activities; 47% of younger patients and 44% of older patients reported high-demand activities (P = .64); 24% of younger patients and 37% of older patients reported medium-demand use (P = .30). Patients younger than 65 years were more likely to require narcotic pain medication (P = .03) and to have disability (P = .0001). CONCLUSION: These data provide initial evidence that commonly held concerns about higher activity levels among younger patients placing excessive demands on the RTSA prosthesis may not be as important as currently thought. Rather, patients seem to self-regulate their activities to minimize pain and maximize essential functions after surgery.

Advanced age diminishes tendon-to-bone healing in a rat model of rotator cuff repair.

BACKGROUND: Advanced patient age is associated with recurrent tearing and failure of rotator cuff repairs clinically; however, basic science studies have not evaluated the influence of aging on tendon-to-bone healing after rotator cuff repair in an animal model. Hypothesis/ PURPOSE: This study examined the effect of aging on tendon-to-bone healing in an established rat model of rotator cuff repair using the aged animal colony from the National Institute on Aging of the National Institutes of Health. The authors hypothesized that normal aging decreases biomechanical strength and histologic organization at the tendon-to-bone junction after acute repair. STUDY DESIGN: Controlled laboratory study. METHODS: In 56 F344xBN rats, 28 old and 28 young (24 and 8 months of age, respectively), the supraspinatus tendon was transected and repaired. At 2 or 8 weeks after surgery, shoulder specimens underwent biomechanical testing to compare load-to-failure and load-relaxation response between age groups. Histologic sections of the tendon-to-bone interface were assessed with hematoxylin and eosin staining, and collagen fiber organization was assessed by semiquantitative analysis of picrosirius red birefringence under polarized light. RESULTS: Peak failure load was similar between young and old animals at 2 weeks after repair (31% vs 26% of age-matched uninjured controls, respectively; P > .05) but significantly higher in young animals compared with old animals 8 weeks after repair (86% vs 65% of age-matched uninjured controls, respectively; P < .01). Eight weeks after repair, fibroblasts appeared more organized and uniformly aligned in young animals on hematoxylin and eosin slides compared with old animals. Collagen birefringence analysis of the tendon-to-bone junction demonstrated that young animals had increased collagen fiber organization and similar histologic structure compared with age-matched controls (53.7 ± 2.4 gray scales; P > .05). In contrast, old animals had decreased collagen fiber organization and altered structure compared with age-matched controls (49.8 ± 3.1 gray scales; P < .01). DISCUSSION: In a rat model of aging, old animals demonstrated diminished tendon-to-bone healing after rotator cuff injury and repair. Old animals had significantly decreased failure strength and collagen fiber organization at the tendon-to-bone junction compared with young animals. This study implies that animal age may need to be considered in future studies of rotator cuff repair in animal models. CLINICAL RELEVANCE: With increasing age and activity level of the population, the incidence of rotator cuff tears is predicted to rise. Despite advances in rotator cuff repair technique, the retear rate remains specifically high in elderly patients. The findings of this research suggest that aging negatively influences tendon-to-bone healing after rotator cuff repair in a validated animal model.

Rotator cuff injuries in professional and recreational athletes.

Professional and recreational athletes involved in contact sports and sports with repetitive overhead motion are at increased risk for rotator cuff tears. Shoulder anatomy, pathology, and biomechanics place unique stress on the rotator cuff tendons during sports activity. Athletes demand effective treatment to quickly return to elite competition. A PubMed search assessed treatment options providing expedited recovery time and return to competition. Twelve of 231 articles fit the objective criteria; 90.5% of professional contact athletes, 40% of professional overhead athletes, and 83.3% of recreational athletes fully recovered following rotator cuff tear surgical repair. Prompt surgical treatment for full-thickness rotator cuff tears may be appropriate for contact athletes and recreational overhead athletes. Although professional overhead athletes have low recovery rates, surgical repair of full-thickness rotator cuff tears may still be indicated. The authors propose a treatment algorithm based on the limited literature (mainly level 4 and 5 evidence).