Fluoroscopically Guided Subacromial Spacer Implantation for Massive Rotator Cuff Tears: Two Years of Prospective Follow-up.

BACKGROUND: Massive rotator cuff tears (MRCTs) are common and have been estimated to account for nearly 40% of all rotator cuff tears. An evolving strategy for management of MRCTs has been the implantation of a degradable subacromial spacer balloon that attempts to restore normal shoulder biomechanics. PURPOSE: To assess the safety and efficacy of fluoroscopically guided balloon spacer implantation under local anesthesia in a cohort of patients with 2 years of postoperative follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The safety and efficacy of using fluoroscopically guided subacromial spacer implantation was assessed in 46 patients. Follow-up visits were scheduled according to routine clinical practice. Shoulder function was evaluated using Constant and American Shoulder and Elbow Society (ASES) scores. RESULTS: Overall, 87.5% (35/40) of patients saw clinically significant improvement in the total Constant and ASES scores from 6 weeks postoperatively, with improvement maintained up to 24 months postoperatively. CONCLUSION: The data suggest that fluoroscopically guided subacromial spacer implantation under local anesthesia is a low-risk, clinically effective option, especially for the elderly population and those patients who have multiple comorbidities or a contraindication to general anesthesia. Patients undergoing subacromial spacer implantation for the treatment of MRCTs had satisfactory outcomes at 2-year follow-up, with a low rate of complications.

In vitro and in vivo degradation behavior and the long-term performance of biodegradable PLCL balloon implants.

Biodegradable poly(l-lactide-co-ε-caprolactone) (PLCL) are used to prepare inflatable balloon implants in treating rotator-cuff injuries and tissue separation. These balloon implants act as a temporary spacer for tissues, while reducing pain and allowing rehabilitation after surgery. It is essential to ensure that each balloon fulfill two requirements after implantation: (1) display a well-defined degradation profile, and (2) remain unaffected by premature rapture or leakage. Storage also affects the stability of a polymer-based implant. Since the balloons are implanted into humans, it is essential to understand their in vitro and in vivo degradation along with their physicochemical properties. It is unpredictable if balloon storage on their performance. Therefore, the in vitro and in vivo degradation behavior of PLCL balloons was examined during one year, and the information obtained was used to correlate reliability under prolonged storage conditions. We investigated changes in weight, melting temperature (Tm), molecular weight distribution (Mw, Mn and PDI), crystallinity (Χ), optical activity [α], and inherent viscosity (η) of the balloons during the entire degradation time. We also examined the molecular properties of the balloons under annealing and extreme temperature conditions, such as the combined effect of temperature and humidity that simulate various storage conditions. We have concluded that degradation of the PLCL balloons is slow, and they remain stable during the test period. Results reveal that the balloons retain their molecular properties under long-term storage, annealing, and extreme temperature conditions. The balloons did not show any variation from reference samples, and they exhibited a constant stability profile even after shelf-storage of more than 3 years. These findings can serve as a case study for evaluating various other biodegradable materials.

Biodegradable implantable balloons: Mechanical stability under physiological conditions.

Rotator cuff tendons injuries occurs as a result of trauma, e.g. due to falling, mechanical injuries and frequent overhead activity and as natural degenerative tears in elderly people. Biodegradable balloon shaped spacer of Poly-(L-lactide-co-ε-caprolactone) (PLCL) are applied in the treatment of these injuries. This type of treatment involves insertion of inflated biodegradable implant into the tissues of the damaged region in the shoulder to avoid shoulder impingement and reduce friction between the acromion and the humeral head and propagation of inflammation. The implant must maintain integrity under significant mechanical loading in order to remain effective. However, with time, the implant is exposed to the risk of failure due to the high pressure caused by the muscular motion and the friction with the bones. We report in this study the limits of the mechanical stability of the PLCL balloon shape spacer (implant) under prolonged cyclic loading, so as to be able to predict their physical stability in vivo. We have demonstrated in an in vitro settings that the implant withstands fatigue cycles for significantly longer than 8 weeks, which provides sufficient time window for patients to perform substantial rehabilitation and recover from an injury. The data presented herein is expected to assist medical practitioners in safety and efficacy measurements and assessment following spacer implantation.

The biodegradable spacer as a novel treatment modality for massive rotator cuff tears: a prospective study with 5-year follow-up.

BACKGROUND: The management of massive, irreparable rotator cuff tears (RCT) is challenging and associated with high failure rates. There are no current consensus or definitive guidelines concerning the optimal surgical treatment for this devastating condition. This study was designed to confirm the long-term safety and efficacy of the biodegradable inflatable InSpace™ system in patients with massive reparable or irreparable RCTs. METHODS: In this open-label, single arm, prospective study, subjects with massive RCT underwent subacromial implantation with the biodegradable spacer. Follow-up visits were scheduled according to routine clinical practice. Shoulder function was evaluated using Total Constant Score (TCS). RESULTS: Twenty-four patients were treated and assessed. Four patients had partial tears, and in three of them RC repair was performed. These patients were not included in the efficacy analyses. Of the participating subjects who reached the 5-year follow-up, 84.6% of the patients showed a clinically significant improvement of at least 15 points in their score, while 61.54% showed at least 25 points of improvement. Only 10% of the treated patients showed no improvement or worsening in the shoulder score comparing to their baseline. An overall improvement in the total CS commencing at 3 months and sustained by 6 months through to 5 years of follow-up (P < 0.0001) was demonstrated. CONCLUSIONS: We conclude that in this initial cohort, arthroscopic implantation of InSpace™ system represented an effective alternative to the existing arthroscopic procedures in patients with painful massive RCT refractory to conservative management. Further randomized controlled trials comparing the clinical and functional outcomes after implantation of the InSpace™ device are warranted.

Long-term Local and Systemic Safety of Poly(L-lactide-co-epsilon-caprolactone) after Subcutaneous and Intra-articular Implantation in Rats.

The use of biodegradable materials is gaining popularity in medicine, especially in orthopedic applications. However, preclinical evaluation of biodegradable materials can be challenging, since they are located in close contact with host tissues and might be implanted for a long period of time. Evaluation of these compounds requires biodegradability and biocompatibility studies and meticulous pathology examination. We describe 2 preclinical studies performed on Sprague-Dawley rats for 52 weeks, to evaluate clinical pathology, biocompatibility, biodegradability, and systemic toxicity after implantation of 2-layered films or saline-inflated balloon-shaped implants of downsized InSpace™ devices (termed "test device"). The test devices are made from a copolymer of poly-L-lactide-co-∊-caprolactone in a 70:30 ratio, identical to the device used in humans, intended for the treatment of rotator cuff tears. Intra-articular film implantation and subcutaneous implantation of the downsized device showed favorable local and systemic tolerability. Although the implanted materials have no inherent toxic or tumorigenic properties, one animal developed a fibrosarcoma at the implantation site, an event that is associated with a rodent-predilection response where solid materials cause mesenchymal neoplasms. This effect is discussed in the context of biodegradable materials along with a detailed description of expected pathology for biodegradable materials in long-term rodent studies.

The modified Fitzpatrick Wrinkle Scale: a clinical validated measurement tool for nasolabial wrinkle severity assessment.

BACKGROUND: The number of existing wrinkle assessment scales makes it difficult to compare the efficacy of cosmetic techniques in rejuvenating photoaged skin. A single and simple assessment scale that reliably quantifies wrinkle depth is needed. OBJECTIVE: The objective was to validate the Modified Fitzpatrick Wrinkle Scale (MFWS) as a nasolabial wrinkle severity assessment tool. METHODS AND MATERIALS: The MFWS comprises three main classes, in which definitions are based on a set of reference photographs and descriptions, and three interclasses, in which definitions are based only on descriptions. Assessors were trained to apply this scale to volunteers and study patients by using photographs of nasolabial wrinkles either alone or with descriptions. Inter- and intraassessment reliability coefficients were calculated using weighted kappa statistics. RESULTS: In patients, the combined intraassessor reliability from both sides of the face was 0.71 (95% confidence interval [CI], 0.68-0.74) when only photographs were used and 0.79 (95% CI, 0.76-0.82) when descriptions were added. Interassessor reliability for the photographs alone was 0.65 (95% CI, 0.62-0.68) and 0.74 (95% CI, 0.69-0.79) for photographs plus descriptions. CONCLUSIONS: The MFWS is a reliable method for quantitative assessment of nasolabial skin folds, with good inter- and intraassessor reliability. Including descriptions with the photographs increased reliability.

Skin test hypersensitivity study of a cross-linked, porcine collagen implant for aesthetic surgery.

BACKGROUND: The use of bovine collagen implants for dermal contour correction is associated with a 3% to 5% incidence of hypersensitivity, which necessitates pretreatment screening by an intradermal skin test. OBJECTIVE: The objective was to determine the incidence of hypersensitivity with the recently developed cross-linked, porcine collagen implant, EVOLENCE (ColBar LifeScience Ltd.), which is used intradermally for correction of rhytids and scars. MATERIALS AND METHODS: Enrolled subjects (n=530) received an intradermal injection of 0.1 mL EVOLENCE implant in the left forearm and a second injection in the right forearm after 2 weeks. Injection sites were assessed clinically at 30 minutes and 72 hours after each injection and at 30 days after the second injection. Serum anticollagen antibody determinations were performed at screening and at the end of the study. RESULTS: Study assessments were completed by 519 subjects. No significant erythematous reactions suggestive of positive hypersensitivity were observed. Most subjects did not display antibodies against porcine Type I collagen at any time, and those who did showed no changes in levels during the study. The single-sided 95% upper confidence limit for the possibility of moderate-to-severe erythematous reactions with the EVOLENCE implant was determined as 0.58% of subjects. CONCLUSION: Because the EVOLENCE implant has a low potential for hypersensitivity, intradermal skin testing before its use appears unnecessary.