InSpace Implant Compared with Partial Repair for the Treatment of Full-Thickness Massive Rotator Cuff Tears: A Multicenter, Single-Blinded, Randomized Controlled Trial.

BACKGROUND: The purpose of this study was to prospectively evaluate the efficacy and safety of a subacromial balloon spacer (InSpace implant; Stryker) compared with arthroscopic partial repair in patients with irreparable, posterosuperior massive rotator cuff tears. METHODS: Patients ≥40 years of age with symptomatic, irreparable, posterosuperior, massive rotator cuff tears and an intact subscapularis who underwent failed nonoperative management were included in this randomized controlled trial comparing the InSpace implant with partial repair. Clinical outcome data were collected at baseline through a 24-month follow-up. The primary outcome was improvement in the American Shoulder and Elbow Surgeons (ASES) scores. The secondary outcomes included change from baseline in the Western Ontario Rotator Cuff (WORC) score, the visual analog scale (VAS) pain score, the Constant-Murley shoulder score, the EuroQol-5 Dimensions-5-Level (EQ-5D-5L) score, active range of motion, and operative time. Complications and reoperations for each group were also recorded. RESULTS: Twenty sites randomized 184 patients: 93 in the InSpace group and 91 in the partial repair group. Significant and clinically relevant improvements in the ASES score from baseline were noted in both groups at Month 12 and were maintained at Month 24. Overall, 83% of patients in the InSpace group and 81% of patients in the partial repair group achieved the ASES minimally clinically important difference threshold, and 82% of patients in the InSpace group and 79% of patients in the partial repair group achieved the substantial clinical benefit threshold. Forward elevation was significantly greater in the InSpace group compared with the partial repair group at Day 10 (p = 0.04), Week 6 (p = 0.0001), Month 12 (p = 0.005), and Month 24 (p = 0.003). The operative time was significantly shorter in the InSpace group (p < 0.0001). No device-related surgical complications were noted, and 4 reoperations after InSpace implantation and 3 reoperations after partial repair were required. CONCLUSIONS: The InSpace implant is an appropriate alternative to partial repair in patients with irreparable posterosuperior massive rotator cuff tears and an intact subscapularis. Notable benefits include early functional recovery and pain relief combined with a shorter operative time. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Infection and nuclear interaction in mammalian cells by 'Candidatus Berkiella cookevillensis', a novel bacterium isolated from amoebae.

BACKGROUND: 'Candidatus Berkiella cookevillensis' and 'Ca. Berkiella aquae' have previously been described as intranuclear bacteria of amoebae. Both bacteria were isolated from amoebae and were described as appearing within the nuclei of Acanthamoeba polyphaga and ultimately lysing their host cells within 4 days. Both bacteria are Gammaproteobacteria in the order Legionellales with the greatest similarity to Coxiella burnetii. Neither bacterium grows axenically in artificial culture media. In this study, we further characterized 'Ca. B. cookevillensis' by demonstrating association with nuclei of human phagocytic and nonphagocytic cell lines. RESULTS: Transmission electron microscopy (TEM) and confocal microscopy were used to confirm nuclear co-localization of 'Ca. B. cookevillensis' in the amoeba host A. polyphaga with 100% of cells having bacteria co-localized with host nuclei by 48 h. TEM and confocal microscopy demonstrated that the bacterium was also observed to be closely associated with nuclei of human U937 and THP-1 differentiated macrophage cell lines and nonphagocytic HeLa human epithelial-like cells. Immunofluorescent staining revealed that the bacteria-containing vacuole invaginates the nuclear membranes and appears to cross from the cytoplasm into the nucleus as an intact vacuole. CONCLUSION: Results of this study indicate that a novel coccoid bacterium isolated from amoebae can infect human cell lines by associating with the host cell nuclei, either by crossing the nuclear membranes or by deeply invaginating the nuclear membranes. When associated with the nuclei, the bacteria appear to be bound within a vacuole and replicate to high numbers by 48 h. We believe this is the first report of such a process involving bacteria and human cell lines.

Effect of recombinant human platelet-derived growth factor-BB-coated sutures on Achilles tendon healing in a rat model: A histological and biomechanical study.

PURPOSE: Repairing tendon injuries with recombinant human platelet-derived growth factor-BB has potential for improving surgical outcomes. Augmentation of sutures, a critical component of surgical tendon repair, by coating with growth factors may provide a clinically useful therapeutic device for improving tendon repair. Therefore, the purpose of this study was to (a) coat Vicryl sutures with a defined dose of recombinant human platelet-derived growth factor-BB without additional coating excipients (e.g. gelatin), (b) quantify the recombinant human platelet-derived growth factor-BB released from the suture, and (c) use the recombinant human platelet-derived growth factor-BB-coated sutures to enhance tendon repair in a rat Achilles tendon transection model. METHODS: Vicryl sutures were coated with 0, 0.3, 1.0, and 10.0 mg/mL concentrations of recombinant human platelet-derived growth factor-BB using a dip-coating process. In vitro release was quantified by an enzyme-linked immunosorbent assay. Acutely transected rat Achilles tendons were repaired using one of the four suture groups (n = 12 per group). Four weeks following repair, the tensile biomechanical and histological (i.e. collagen organization and angiogenesis) properties were determined. RESULTS: A dose-dependent bolus release of recombinant human platelet-derived growth factor-BB occurred within the first hour in vitro, followed by a gradual release over 48 h. There was a significant increase in ultimate tensile strength (p < 0.01) in the two highest recombinant human platelet-derived growth factor-BB dose groups (1.9 ± 0.5 and 2.1 ± 0.5 MPa) relative to controls (1.0 ± 0.2 MPa). The modulus significantly increased (p = 0.031) with the highest recombinant human platelet-derived growth factor-BB dose group (7.2 ± 3.8 MPa) relative to all other groups (control: 3.5 ± 0.9 MPa). No significant differences were identified for the maximum load or stiffness. The histological collagen and angiogenesis scores were comparable in all groups, although there was a trend for improved collagen organization in the recombinant human platelet-derived growth factor-BB-treated groups (p = 0.054). CONCLUSIONS: The results of this study suggest that recombinant human platelet-derived growth factor-BB can be used to reproducibly coat Vicryl sutures and improve remodeling in a rat Achilles tendon transection model by significantly decreasing the resulting cross-sectional area, thus improving the material properties of the repaired tendon.

Augmentation of a rotator cuff suture repair using rhPDGF-BB and a type I bovine collagen matrix in an ovine model.

BACKGROUND: Rotator cuff tears are a common source of shoulder pain. High rates (20%-94%) of structural failure of the repair have been attributed to multiple factors, including poor repair tissue quality and tendon-to-bone integration. Biologic augmentation using growth factors has potential to promote tendon-to-bone integration, improving the function and long-term success of the repair. One such growth factor is platelet-derived growth factor-BB (PDGF-BB), which has been shown to improve healing in tendon and bone repair models. HYPOTHESIS: Recombinant human PDGF-BB (rhPDGF-BB) combined with a highly porous type I bovine collagen matrix will improve the biomechanical function and morphologic appearance of the repair in a dose-dependent manner, relative to a suture-only control, after 12 weeks in an acute ovine model of rotator cuff repair. STUDY DESIGN: Controlled laboratory study. METHODS: An interpositional graft consisting of rhPDGF-BB and a type I collagen matrix was implanted in an ovine model of rotator cuff repair. Biomechanical and histologic analyses were performed to determine the functional and anatomic characteristics of the repair after 12 weeks. RESULTS: A significant increase in the ultimate load to failure was observed in repairs treated with 75 µg (1490.5 ± 224.5 N, P = .029) or 150 µg (1486.6 ± 229.0 N, P = .029) of rhPDGF-BB, relative to suture-only controls (910.4 ± 156.1 N) and the 500-µg rhPDGF-BB group (677.8 ± 105.9 N). The 75-µg and 150-µg rhPDGF-BB groups also exhibited increased tendon-to-bone interdigitation histologically. No differences in inflammation or cellularity were observed among treatments. CONCLUSION: This study demonstrated that an interpositional graft consisting of rhPDGF-BB (75 or 150 µg) and a type I collagen matrix was able to improve the biomechanical strength and anatomic appearance in an ovine model of rotator cuff repair compared to a suture-only control and the 500-µg rhPDGF-BB group. CLINICAL RELEVANCE: Recombinant human PDGF-BB combined with a type I collagen matrix has potential to be used to augment surgical repair of rotator cuff tears, thereby improving clinical success.