Neer Award 2018: Benzoyl peroxide effectively decreases preoperative Cutibacterium acnes shoulder burden: a prospective randomized controlled trial.

BACKGROUND: Benzoyl peroxide (BPO) solutions effectively reduce Cutibacterium acnes (formerly Propionibacterium acnes) on the face, neck, and back in nonoperative settings. This study compared preoperative application of BPO vs. chlorhexidine gluconate (CHG) in decreasing shoulder C acnes skin burden in surgical patients. METHODS: Eighty patients undergoing shoulder surgery were prospectively enrolled in a randomized double-blind trial at 1 institution from August 2015 to April 2017. Participants were randomized to 5% BPO or 4% CHG for 3 consecutive days. The nonoperative shoulder had no intervention and served as the negative control. Skin cultures of both shoulders were obtained via a detergent scrub technique the day of surgery at anterior, lateral, and posterior sites and the axilla. RESULTS: Fewer positive cultures were obtained from the BPO-treated side compared with the contralateral side (P = .0003), and no change was shown for the CHG group (P = .80). Shoulders treated with BPO showed a statistically significant reduction in C acnes counts compared with CHG at anterior (P = .03) and posterior (P = .005) portal sites. No significant difference was found at the axilla (P = .99) or lateral portal site (P = .08). No postoperative infections or wound complications occurred in either group. CONCLUSIONS: BPO is more effective than CHG at reducing C acnes on the shoulder. Decreasing the skin burden of C acnes may reduce intraoperative wound contamination and postoperative infection. BPO should be considered as an adjunctive preoperative skin preparation considering its potential benefit, low risk, and low cost.

Sonographically guided percutaneous first annular pulley release: cadaveric safety study of needle and knife techniques.

OBJECTIVE: The purpose of this study was to assess the safety of sonographically guided percutaneous finger and thumb first annular (A1) pulley releases performed using needle and hook knife techniques in an unembalmed cadaveric model. METHODS: A single operator completed 50 (40 fingers and 10 thumbs) sonographically guided percutaneous A1 pulley releases in unembalmed cadavers using previously described needle and hook knife techniques and simulated local anesthesia. Half of the fingers and thumbs were completed with each technique. An experienced observer blinded to the technique dissected each specimen and assessed for neurovascular, flexor tendon, and A2 pulley injury. Completeness of release was also recorded as a secondary outcome. RESULTS: No neurovascular or A2 pulley injury occurred in any digit, regardless of technique. No significant flexor tendon injury was seen in any digit, although minor surface scratches were visualized in 3 cases (6%; 2 knife and 1 needle). The hook knife technique was significantly more likely to result in a complete pulley release compared to the needle technique (22 of 25 [88%] versus 8 of 25 [32%]; P < .001). CONCLUSIONS: Sonographically guided percutaneous A1 pulley releases can be performed safely using previously described needle and hook knife techniques. The safety margin for thumb releases is less than that for finger releases, particularly with respect to the radial digital nerve. These cadaveric data support recently published clinical investigations recommending consideration of sonographically guided percutaneous A1 pulley release in the management of patients with a disabling trigger finger.

Sonographically guided proximal tibiofibular joint injection: technique and accuracy.

OBJECTIVE: The purpose of this investigation was to describe a technique for sonographically guided proximal tibiofibular joint (PTFJ) injections and compare its accuracy with that of palpation guided injections in a cadaveric model. METHODS: A single experienced operator completed 12 sonographically guided and 12 palpation guided PTFJ injections in unembalmed cadavers. The injection order was randomized, and all injections were completed with diluted colored latex. Coinvestigators blinded to the injection technique dissected each specimen and graded the colored latex location as accurate (in the PTFJ), accurate with overflow (within the PTFJ but also in other regions), or inaccurate (no latex in the joint). For statistical analysis, all injections placing latex within the PTFJ were considered "accurate," whereas "inaccurate" injections resulted in no PTFJ latex. RESULTS: All 12 sonographically guided PTFJ injections accurately placed latex into the PTFJ (100% accuracy), whereas only 7 of 12 palpation guided injections (58%) placed latex within the PTFJ (P = .01). All 5 inaccurate palpation guided injections were superficial and inferior to the PTFJ. Four of 12 accurate sonographically guided PTFJ injections (33%) showed some overflow into the adjacent anterior musculature, whereas 5 of the accurate palpation guided injections (42%) resulted in overflow into the anterior musculature (1), knee joint (2), or both (2). CONCLUSIONS: This cadaveric investigation suggests that sonographic guidance can be used to inject the PTFJ with a high degree of accuracy and should be considered superior to palpation guidance. Clinicians should consider using sonographic guidance to inject the PTFJ for diagnostic or therapeutic purposes when clinically indicated.

Sonographic evaluation of the distal biceps tendon using a medial approach: the pronator window.

OBJECTIVE: The purpose of this report is to describe and demonstrate the potential advantages of a technique to image the distal biceps tendon using a medial approach: the pronator window. METHODS: Distal biceps tendon imaging via the medial approach was shown using real-time sonography on an asymptomatic volunteer as well as cadaveric anatomic dissection. RESULTS: The medial approach images the biceps tendon with minimal anisotropy while providing several potential advantages, including (1) complete visualization of the ulnarly facing radial tuberosity and the tapered distal biceps insertion, (2) increased contrast and reduced beam attenuation at the interface between the biceps tendon and overlying brachial artery, and (3) avoidance of the beam-attenuating effects of the supinator encountered when imaging the tendon from a lateral approach. CONCLUSIONS: The medial approach to image the distal biceps tendon complements previously described techniques and should be considered in the evaluation of patients presenting with distal biceps tendon disorders. Future clinical studies may elucidate the relative advantages and disadvantages of sonographic distal biceps imaging techniques in specific patient populations.

Sonographically guided popliteus tendon sheath injection: techniques and accuracy.

OBJECTIVE: The purpose of this investigation was to describe two sonographically guided popliteus tendon sheath injection techniques and determine their accuracy in a cadaveric model. METHODS: A single experienced operator completed 24 sonographically guided popliteus tendon sheath injections, 12 using a longitudinal approach and 12 using a transverse approach relative to the tendon. The injection order was randomized, and all injections were completed with diluted colored latex. Coinvestigators blinded to the injection technique dissected each specimen and graded the colored latex location as accurate (in the sheath), accurate with overflow (within the sheath but also in other regions), or inaccurate (no latex in the sheath). RESULTS: All 12 sonographically guided popliteus sheath injections using the longitudinal approach placed latex into the sheath. Eight of these injections (67%) also resulted in overflow into the knee joint. Ten of 12 transverse approach injections placed latex into the sheath (83%), with 7 of these (70%) also producing overflow into the knee joint. Two of 12 transverse injections (17%) placed latex only into the knee joint and were therefore inaccurate. CONCLUSIONS: Sonographic guidance can be used to inject the popliteus tendon sheath with a high degree of accuracy. Although the longitudinal approach is potentially more accurate, both approaches may result in injectate overflow into the knee joint, likely through the popliteus hiatus.

Risk factors for increased shoulder Cutibacterium acnes burden.

BACKGROUND: Cutibacterium acnes is the primary cause of shoulder surgery infections, but the predisposition to larger skin counts and potentially higher risk for postoperative infection remains unclear. This study aimed to quantify risk factors influencing endogenous C. acnes burden and to compare counts among 4 shoulder sites. METHODS: C. acnes counts were quantified via a detergent scrub technique for 173 participants. Bivariate and multivariable stepwise linear regression statistical analyses were used to investigate the association of sex, age, ethnicity, degree of hirsutism, diabetes, smoking status, body mass index, and location with counts. A separate Wilcoxon rank-sum test was performed analyzing counts of East/Southeast Asians vs. all other ethnicities. RESULTS: Sex, age, degree of hirsutism, diabetes, smoking status, and body mass index were included in the multivariable stepwise linear regression analysis. The multiple regression analysis isolated individuals <40 years with the highest burden (P = .001). Males had a 191% increase in C. acnes counts compared with females (P = .001). Increased hirsutism was further indicated to be a risk factor for the male sex although not in a dose-dependent manner (P = .027). Wilcoxon rank-sum test results found that East/Southeast Asians had the lowest load (P = .019), although not significant in the multivariate model. CONCLUSION: Surgical site C. acnes infections occur more frequently in younger males, and males <40 years with shoulder-specific hirsutism have the highest preoperative burden. East/Southeast Asians have lower raw counts of C. acnes compared with other ethnicities that may be related to less hirsutism.

Diminished Canonical ß-Catenin Signaling During Osteoblast Differentiation Contributes to Osteopenia in Progeria.

Patients with Hutchinson-Gilford progeria syndrome (HGPS) have low bone mass and an atypical skeletal geometry that manifests in a high risk of fractures. Using both in vitro and in vivo models of HGPS, we demonstrate that defects in the canonical WNT/ß-catenin pathway, seemingly at the level of the efficiency of nuclear import of ß-catenin, impair osteoblast differentiation and that restoring ß-catenin activity rescues osteoblast differentiation and significantly improves bone mass. Specifically, we show that HGPS patient-derived iPSCs display defects in osteoblast differentiation, characterized by a decreased alkaline phosphatase activity and mineralizing capacity. We demonstrate that the canonical WNT/ß-catenin pathway, a major signaling cascade involved in skeletal homeostasis, is impaired by progerin, causing a reduction in the active ß-catenin in the nucleus and thus decreased transcriptional activity, and its reciprocal cytoplasmic accumulation. Blocking farnesylation of progerin restores active ß-catenin accumulation in the nucleus, increasing signaling, and ameliorates the defective osteogenesis. Moreover, in vivo analysis of the Zmpste24-/- HGPS mouse model demonstrates that treatment with a sclerostin-neutralizing antibody (SclAb), which targets an antagonist of canonical WNT/ß-catenin signaling pathway, fully rescues the low bone mass phenotype to wild-type levels. Together, this study reveals that the ß-catenin signaling cascade is a therapeutic target for restoring defective skeletal microarchitecture in HGPS. © 2018 American Society for Bone and Mineral Research.

Fatty Infiltration Is a Prognostic Marker of Muscle Function After Rotator Cuff Tear.

BACKGROUND: Massive rotator cuff tears (RCTs) begin as primary tendon injuries and cause a myriad of changes in the muscle, including atrophy, fatty infiltration (FI), and fibrosis. However, it is unclear which changes are most closely associated with muscle function. PURPOSE: To determine if FI of the supraspinatus muscle after acute RCT relates to short-term changes in muscle function. STUDY DESIGN: Controlled laboratory study. METHODS: Unilateral RCTs were induced in female rabbits via tenotomy of the supraspinatus and infraspinatus. Maximal isometric force and rate of fatigue were measured in the supraspinatus in vivo at 6 and 12 weeks after tenotomy. Computed tomography scanning was performed, followed by histologic analysis of myofiber size, FI, and fibrosis. RESULTS: Tenotomy resulted in supraspinatus weakness, reduced myofiber size, FI, and fibrosis, but no differences were evident between 6 and 12 weeks after tenotomy except for increased collagen content at 12 weeks. FI was a predictor of supraspinatus weakness and was strongly correlated to force, even after accounting for muscle cross-sectional area. While muscle atrophy accounted for the loss in force in tenotomized muscles with minimal FI, it did not account for the greater loss in force in tenotomized muscles with the most FI. Collagen content was not strongly correlated with maximal isometric force, even when normalized to muscle size. CONCLUSION: After RCT, muscle atrophy results in the loss of contractile force from the supraspinatus, but exacerbated weakness is observed with increased FI. Therefore, the level of FI can help predict contractile function of torn rotator cuff muscles. CLINICAL RELEVANCE: Markers to predict contractile function of RCTs will help determine the appropriate treatment to improve functional recovery after RCTs.

Treatment of chronic tendinopathy with ultrasound-guided needle tenotomy and platelet-rich plasma injection.

OBJECTIVE: To determine whether ultrasound (US)-guided percutaneous needle tenotomy followed by a platelet-rich plasma (PRP) injection would result in pain reduction, functional improvement, or structural alterations in patients with chronic, recalcitrant tendinopathy. DESIGN: Part A was a retrospective observational study. Part B was a prospective observational study. SETTING: Outpatient academic sports medicine center. PARTICIPANTS: Patients were required to have chronic (>3 months), recalcitrant tendinopathy treated with US-guided percutaneous tenotomy and PRP injection between January 2007 and October 2009. Fifty-one subjects met the inclusion criteria. Forty-one (80%) participated in part A of the study, whereas 34 subjects (67%) participated in part B. METHODS: In part A, subjects completed a survey obtaining anthropomorphic, demographic, pain, and functional data. Subjects' platelet, hemoglobin, and white blood cell concentrations from their whole-blood and PRP samples were also obtained. In part B, subjects returned to the clinic after US-guided percutaneous needle tenotomy and PRP injection for a diagnostic US, which was compared with their preprocedure diagnostic US. MAIN OUTCOME MEASURES: The main outcome measures included changes in pain, function, and tendon characteristics. RESULTS: The tendinopathy location was in the upper extremity in 10 subjects (24.4%), was in the lower extremity in 31 subjects (75.6%), and had been present for a mean of 40 months. The mean postprocedure follow-up was 14 months, and the maximum benefits occurred 4 months postprocedure. There were mean functional and worst-pain improvements of 68% and 58%, respectively. Eighty-three percent of subjects were satisfied with their outcomes and would recommend the procedure to a friend. Although no tendons demonstrated a normal sonographic appearance after the procedure, 84% of subjects had an improvement in echotexture, 64% had a resolution of intratendinous calcifications, and 82% had a decrease in intratendinous neovascularity. None of the variables analyzed in this study demonstrated a significant correlation with pain or functional outcome measures. CONCLUSIONS: In this case series, we found US-guided percutaneous needle tenotomy followed by PRP injection to be a safe and effective treatment for chronic, recalcitrant tendinopathy, and this treatment was associated with sonographically apparent improvements in tendon morphology. However, because of the intrinsic limitations of the study design and the heterogeneity of treated tendons, further research is required to corroborate our findings.

Accuracy of ultrasound-guided versus palpation-guided acromioclavicular joint injections: a cadaveric study.

OBJECTIVE: To describe a technique for sonographically guided acromioclavicular joint (ACJ) injections and compare its accuracy to palpation-guided injections in a cadaveric model. DESIGN: Prospective laboratory investigation. SETTING: Procedural skills laboratory at a tertiary medical center. METHODS: A single experienced operator completed 10 sonographically guided and 10 palpation-guided ACJ injections in unembalmed cadavers. Injection order was randomized and all injections were completed with diluted colored latex. Co-investigators blinded to the injection technique dissected each specimen and graded colored latex location as accurate (in the ACJ), partially accurate (within and outside the ACJ), or inaccurate (no latex in the ACJ). MAIN OUTCOME MEASUREMENTS: Direct assessment of injected dye within the ACJ via dissection. RESULTS: All 10 sonographically guided ACJ injections accurately placed latex into the ACJ (100% accuracy), whereas only 4 of 10 (40%) palpation-guided injections accurately placed latex within the ACJ (P = .0054). CONCLUSIONS: This cadaveric investigation suggests that sonographic guidance can be used to inject the ACJ with a high degree of accuracy, and should be considered superior to palpation guidance. Clinicians should consider using sonographic guidance to inject the ACJ when diagnostic specificity is paramount or when otherwise clinically indicated.