Primary Rotator Cuff Bridging Reconstruction Shows Better Clinical and Radiographic Results Than Revision Bridging Reconstruction.

Purpose: To evaluate the outcome of revision rotator cuff bridging reconstruction (BR) as compared to primary BR in a large cohort of patients. Methods: A retrospective chart review was conducted for patients who underwent BR using dermal allograft for large/massive rotator cuff tears between 2010 and 2018. Patients who completed Western Ontario Rotator Cuff Index (WORC) and Disability of the Arm, Shoulder, and Hand (DASH) scores both pre- and postoperatively were included. Pre- and postoperative magnetic resonance imaging scans were compared to assess for differences in fatty infiltration, muscle atrophy, and graft status. Results: Eighty patients met the inclusion criteria, including 43 patients who underwent BR as a primary surgery and 37 patients who underwent revision BR. The mean follow-up duration was 5.7 ± 1.9 years in the primary group and 5.8 ± 2.0 years in the revision group. Both WORC and DASH scores significantly improved from pre- to postoperatively for both the primary and revision groups (P < .05). The primary group had significantly better postoperative WORC and DASH scores at 6 months, 1 year, and final follow-up (P < .05). Failure rate of the graft was higher in the revision group compared to primary group (14.3% vs 6.1%, respectively; P = .337), and the amount of fatty infiltration of supraspinatus and infraspinatus muscles significantly improved in patients who received primary BR compared to revision BR (P < .05). Conclusions: BR using dermal allograft for large/massive irreparable rotator cuff tears showed improvement of functional outcomes, with primary cases resulting in better improvement in patient-reported outcomes compared to revision cases. Primary BR was also associated with better postoperative fatty infiltration of supraspinatus and infraspinatus muscles. Level of Evidence: Level III, retrospective cohort study.

Interposition Graft Bridging Reconstruction of Irreparable Rotator Cuff Tears Using Acellular Dermal Matrix: Medium-Term Results.

PURPOSE: In this study, we aimed to evaluate the medium-term clinical outcomes for patients who underwent bridging reconstruction. METHODS: A retrospective chart review was conducted for all patients who underwent bridging reconstruction between 2010 and 2018. Patients who were missing either pre- or postoperative outcome scores were excluded. All included patients completed self-reported questionnaires (Western Ontario Rotator Cuff [WORC] and Disabilities of the Arm, Shoulder and Hand [DASH]) pre- and postoperatively at 6 months, 1 year, and annually thereafter. All scores were reported out of 100. RESULTS: Ninety-one patients initially met our inclusion criteria, and 33 were excluded owing to lack of either pre- or postoperative outcome scores. Nine patients were lost to follow-up; therefore, 49 patients were finally evaluated, including 30 males (61.2%) and 19 females (38.8%) with an age of 59.6 ± 10.4 years (mean ± standard deviation) and mean follow-up of 5.3 years (range 2 to 9). Both WORC and DASH scores significantly improved from pre- to postoperatively (WORC: 69.6 ± 12.2 to 27.9 ± 23.7, P < .001; DASH: 51.5 ± 17.5 to 24.5 ± 23.0, P = .001). For WORC and DASH, 92% and 74% of patients, respectively, met the minimal clinical importance difference. CONCLUSION: Our results showed that patients' clinical outcome scores significantly improved with an average of 5-year follow-up, which demonstrates that bridging reconstruction is a safe procedure with promising midterm clinical outcomes. LEVEL OF EVIDENCE: IV, retrospective case series.

Bridging Allograft Reconstruction Is Superior to Maximal Repair for the Treatment of Chronic, Massive Rotator Cuff Tears: Results of a Prospective, Randomized Controlled Trial.

BACKGROUND: Despite advances in surgical techniques, the use of maximal repair to treat large or massive rotator cuff tears results in a high retear rate postoperatively. Currently, no randomized controlled trials have compared the outcomes of maximal repair with interposition dermal allograft bridging reconstruction. HYPOTHESIS: We hypothesized that large or massive rotator cuff tendon tears reconstructed using bridging dermal allograft would have better clinical outcomes 2 years postoperatively, as measured using the Western Ontario Rotator Cuff (WORC) index, than would those receiving the current gold standard treatment of debridement and maximal repair alone. We also expected that patients treated via bridging reconstruction using dermal allograft would have fewer postoperative failures as assessed using postoperative magnetic resonance imaging scans. STUDY DESIGN: Randomized controlled trial; Level of evidence 1. METHODS: A sample size of 30 patients (determined using a priori sample size calculation) with massive, retracted rotator cuff tears were randomly allocated to 1 of 2 groups: maximal repair or bridging reconstruction using dermal allograft. All patients completed questionnaires (WORC and Disabilities of the Arm, Shoulder and Hand [DASH]) preoperatively and postoperatively at 3 months, 6 months, 1 year, and 2 years. The primary outcome of this study was the WORC index at 2 years. Secondary outcomes included healing rate, progression of rotator cuff arthropathy, and postoperative acromiohumeral distance in both groups. RESULTS: Patients treated via bridging reconstruction using dermal allograft had better postoperative WORC and DASH scores (23.93 ± 24.55 and 15.77 ± 19.27, respectively) compared with patients who received maximal repair alone (53.36 ± 31.93 and 34.32 ± 23.31, respectively). We also noted increased progression to rotator cuff arthropathy in the maximal repair group with an increased retear rate when compared with the reconstruction group (87% and 21%, respectively; P < .001). The acromiohumeral distance was maintained in the reconstruction group but significantly decreased in the maximal repair group. CONCLUSION: Rotator cuff bridging reconstruction using a dermal allograft demonstrated improved patient-reported outcomes as measured using the WORC index 2 years postoperatively. This technique also showed favorable structural healing rates and decreased progression to arthropathy compared with maximal repair. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01987973).

Large area used by squirrel gliders in an urban area, uncovered using GPS telemetry.

The squirrel glider (Petaurus norfolcensis) is a threatened, gliding marsupial that persists in fragmented landscapes despite its restricted capacity to cross large gaps. As measures to maintain and/or restore suitable habitat depend on knowledge about the species' ecological requirements, we investigated the area used by squirrel gliders in an urban area near Newcastle, Australia. Using GPS telemetry data and the autocorrelated kernel density estimator, we estimated area used to average 10.8 ha and varied from 4.6 to 15 ha, which is equal to or greater than found in previous studies that spanned longer time periods. This has implications when identifying the minimum patch size necessary for ensuring the long-term conservation of a squirrel glider population.

The Reduction of Heterotopic Ossification Incidence After Hip Arthroscopy in Patients Treated With Selective Cyclooxygenase 2 Inhibitor (Celecoxib).

PURPOSE: To evaluate the effectiveness of celecoxib, a selective cyclooxygenase 2 inhibitor, in reducing heterotopic ossification (HO) after hip arthroscopic surgery and to evaluate celecoxib's impact on clinical outcomes. METHODS: We performed a retrospective review of patients who received hip arthroscopy performed by the same surgeon between January 1, 2012, and December 31, 2016. Patients who had an allergy to sulfa drugs, had pre-existing HO or previous surgery on the operative side, or failed to complete radiographic follow-up at 6 months postoperatively were excluded. Patients in the treatment group received 400 mg of celecoxib postoperatively for 6 weeks, whereas the control group received no postoperative celecoxib. The incidence of HO was assessed using anteroposterior radiographs obtained at 6 months, 1 year, and 2 years postoperatively. Patients completed the International Hip Outcome Tool 33 survey, and the proportion of patients who met the minimal clinically important difference, substantial clinical benefit (SCB), and absolute SCB was calculated. RESULTS: A total of 559 patients were identified. After application of the exclusion criteria, 454 patients were included in the study (211 in control group and 243 in treatment group). The overall incidence of HO was 20.3% (n = 92). The treatment group had a significantly lower incidence of HO at 6 months (P = .006), 1 year (P < .001), and 2 years (P = .008) postoperatively. At 2 years postoperatively, the treatment group had a significantly higher International Hip Outcome Tool 33 score on average: 64.2 versus 57.3 (P = .023). No significant difference in the proportion of patients reaching the minimal clinically important difference, SCB, or absolute SCB was found at any of the postoperative time points. CONCLUSION: The findings of this study suggest that a prophylactic treatment regimen of 400 mg of celecoxib once daily for 6 weeks significantly reduces the incidence of HO formation after hip arthroscopic surgery; however, it did not impact clinical outcomes. LEVEL OF EVIDENCE: Level III, retrospective, comparative case-control study.

Radiographic Analysis of Glenoid Size and Shape After Arthroscopic Coracoid Autograft Versus Distal Tibial Allograft in the Treatment of Anterior Shoulder Instability.

BACKGROUND: The Latarjet procedure for autograft transposition of the coracoid to the anterior rim of the glenoid remains the most common procedure for reconstruction of the glenoid after shoulder instability. The anatomic glenoid reconstruction using distal tibial allograft has gained popularity and is suggested to better match the normal glenoid size and shape. However, concerns about decreased healing and increased resorption arise when an allograft bone is used. PURPOSE: To use radiological findings to evaluate the arthroscopic reconstruction of the glenoid with respect to the size, shape, healing, and resorption of coracoid autograft versus distal tibial allograft. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective review was performed of 48 consecutive patients who had an arthroscopic bony reconstruction of the glenoid (12 coracoid autograft, 36 distal tibial allograft), diagnosed anterior shoulder instability, and computed tomography (CT)-confirmed glenoid bone loss more than 20%. Coracoid autograft was performed only when tibial allograft was not accessible from a bone bank. Two fellowship-trained musculoskeletal radiologists reviewed pre- and postoperative CT scans at a minimum follow-up of 6 months for the following: graft position, glenoid concavity, cross-sectional area, width, version, total area, osseous union, and graft resorption. Clinical outcome was noted in terms of instability, subluxation, and dislocation at a minimum follow-up of 2 years. Simple logistic regression, 2-tailed independent-sample t tests, paired t tests, and Fisher exact tests were performed. RESULTS: Graft union was seen in 9 of the 12 patients (75%) who had coracoid autograft and 34 of the 36 patients (94%) who had tibial allograft (odds ratio, 5.66; 95% CI, 0.81-39.20; P = .08). The odds ratio comparing allograft to coracoid for overall resorption was 7.00 (95% CI, 1.65-29.66; P = .008). Graft resorption ≥50% was seen in 3 (8%) of the patients who had tibial allograft and none of the patients who had coracoid autograft. Graft resorption less than 50% was seen in the majority of patients in both groups: 27 (73%) patients with tibial allograft and 5 (42%) patients with coracoid autograft. No statistically significant difference was found between the 2 procedures regarding anteroposterior diameter of graft ( P = .81) or graft cross-sectional area ( P = .93). However, a significant difference was observed in step formation between the 2 procedures ( P < .001). Two patients experienced subluxations in the coracoid group (16%) as well as 2 patients in the tibial allograft group (6%) with a P value of .25. CONCLUSION: Arthroscopic anatomic glenoid reconstruction via distal tibial allograft showed similar bony union but higher resorption compared with coracoid autograft. Even so, no statistically significant difference was found between the 2 procedures regarding final graft surface area, the size of grafts, and the anteroposterior dimensions of the reconstructed glenoids. These short-term results suggest that distal tibial allografts can be used as an alternative to coracoid autograft in the recreation of glenoid bony morphologic features.

Biphasic electrical field stimulation aids in tissue engineering of multicell-type cardiac organoids.

The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5 V/cm, 1 Hz, 1 ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5 V/cm, 1 Hz, 2 ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence.