Understanding the Role of Surface Modification of Randomized Trabecular Titanium Structures in Bone Tissue Regeneration: An Experimental Study.

Background and Objectives: Three-dimensional (3D) metallic trabecular structures made by additive manufacturing (AM) technologies promote new bone formation and osteointegration. Surface modifications by chemical treatments can improve the osteoconductive properties of metallic structures. An in vivo study in sheep was conducted to assess the bone response to randomized trabecular titanium structures that underwent a surface modification by chemical treatment compared to the bone response to the untreated specimens. Material and Methods: Sixteen specimens with a randomized trabecular titanium structure were implanted in the spongious bone of the distal femur and proximal tibia and the cortical bone of the tibial diaphysis of two sheep. Of them, eight implants had undergone a chemical treatment (treated) and were compared to eight implants with the same structure but native surfaces (native). The sheep were sacrificed at 6 weeks. Surface features of the lattice structures (native and treated) were analyzed using a 3D non-contact profilometer. Compression tests of 18 lattice cubes were performed to investigate the mechanical properties of the two structures. Excellent biocompatibility for the trabecular structures was demonstrated in vitro using a cell mouse fibroblast culture. Histomorphometric analysis was performed to evaluate bone implant contact and bone ingrowth. Results: A compression test of lattice cubic specimens revealed a comparable maximum compressive strength value between the two tested groups (5099 N for native surfaces; 5558 N for treated surfaces; p > 0.05). Compared to native surfaces, a homogenous formation of micropores was observed on the surface of most trabeculae that increased the surface roughness of the treated specimens (4.3 versus 3.2 µm). The cellular viability of cells seeded on three-dimensional structure surfaces increased over time compared to that on plastic surfaces. The histomorphometric data revealed a similar behavior and response in spongious and cortical bone formation. The percentage of the implant surface in direct contact with the regenerated bone matrix (BIC) was not significantly different between the two groups either in the spongious bone (BIC: 27% for treated specimens versus 30% for native samples) or in the cortical bone (BIC: 75% for treated specimens versus 77% for native samples). Conclusions: The results of this study reveal rapid osseointegration and excellent biocompatibility for the trabecular structure regardless of surface treatment using AM technologies. The application of implant surfaces can be optimized to achieve a strong press-fit and stability, overcoming the demand for additional chemical surface treatments.

In vivo osseointegration of a randomized trabecular titanium structure obtained by an additive manufacturing technique.

The additive manufacturing techniques (AM) are able to realize three-dimensional trabecular structures that mimic the trabecular structure of the bone. An in vivo study in sheep was carried out with the aim of assessing the bone response and the trend of osteointegration of a randomized trabecular titanium structure produced by the AM technique. In 6 sheep were implanted 84 specimens with a trabecular titanium structure (4 implants in the femur distal epiphysis; 4 implants in the tibial plate; 6 implants in the tibial shaft). Sheep were sacrificed at 3 postoperative time-points: 6 weeks, 10 weeks, 14 weeks. Histomorphometric analysis was performed for the evaluation of Bone Implant Contact, and Bone Ingrowth. A standard push-out test was used to analyze the mechanical characteristics of the bone-implant interface. The histomorphometric data and biomechanical tests showed a fast osseointegration of the specimens both in the cancellous and in the cortical bone. The quantitative analysis of osseointegration data in cancellous bone showed the percentage of the surface of the implant in direct contact with the regenerated bone matrix significantly improved from 28% at 6 weeks to 54% at 14 weeks. An early osseointegration occurred in cortical bone showing that 75% of surface of implant was in direct contact with regenerated bone after 6 weeks; this value increased to 85% after 14 weeks. Mechanical tests revealed an early improvement of mean peak load of implants at 10 weeks (4486 N ± 528 N) compared to values at 6 weeks (2516 N ± 910 N) confirming the high rate of progression of osseointegration in the cortical bone. The non-mineralized matrix followed an increasing process of mineralization almost completely after 14 weeks. The results of this study have showed a rapid osseointegration and excellent biocompatibility for a randomized trabecular titanium structure that should be confirmed by clinical investigations.

CoCrMo alloys ions release behavior by TiNbN coating: an in vitro study.

The aim of the study was to show in vitro the greater inertness to the corrosion body fluid of TiNbN coating than the CoCrMo alloy substrate. The prosthetic component under study was a femoral component of total knee prosthesis in CoCrMo alloy coated in TiNbN with Physical Vapor Deposition technique immersed in static Hank's balanced salt solution (HBS) (pH = 6) for at least 34 months at a constant temperature of 37 °C. Another uncoated prosthetic component of CoCrMo alloy with the same type and size was left in static immersion in the same solution and for the same period of time. Scanning electron microscope (SEM) analysis was performed to investigate adhesion and proliferation at 24, 48, 72 h after seeding of 104 sub-confluents osteoblast-like cells (SaOS-2) cells on scaffold. The results of the study showed a reduction in the concentration of the metal ions released from the TiNbN-coated femoral component surface compared to the uncoated surface in the HBS solution. The overall reduction of the ions for the TiNbN-coated femoral component compared to the uncoated one was 80.1 ± 2%, 62.5% ± 8% and 48% ± 10% for Co, Cr, Mo, respectively (p < 0.01). SEM analysis confirmed the healthy state of the cells, the cellular adhesion and proliferation of SaOS-2 on the TiNbN-coated specimen. Although the results observed in vitro for the TiNbN coating are encouraging, clinical studies are certainly needed to be performed in order to understand how these positive findings can be translated in vivo and to determine the clinical benefit of TiNbN coating.

Effects of Vitamin E-Stabilized Ultra High Molecular Weight Polyethylene on Oxidative Stress Response and Osteoimmunological Response in Human Osteoblast.

High Crosslink process was introduced in the development of joint prosthetic devices, in order to decrease the wear rate of ultrahigh molecular weight polyethylene (UHMWPE), but it also triggers the formation of free radicals and oxidative stress, which affects the physiological bone remodeling, leading to osteolysis. Vitamin E stabilization of UHMWPE was proposed to provide oxidation resistance without affecting mechanical properties and fatigue strength. The aim of this study is to evaluate the antioxidant effect of vitamin E added to UHMWPE on oxidative stress induced osteolysis, focusing in particular on the oxidative stress response in correlation with the production of osteoimmunological markers, Sclerostin and DKK-1, and the RANKL/OPG ratio compared to conventional UHMWPE wear debris. Human osteoblastic cell line SaOS2 were incubated for 96 h with wear particles derived from crosslinked and not crosslinked Vitamin E-stabilized, UHMWPE without Vitamin E, and growth medium as control. Cellular response to oxidative stress, compared to not treat cells, was evaluated in terms of proteins O-GlcNAcylation, cellular levels of OGA, and OGT proteins by immunoblotting. O-GlcNAcylation and its positive regulator OGT levels are increased in the presence of Vitamin E blended UHMWPE, in particular with not crosslinked Vit E stabilized UHMWPE. Conversely, the negative regulator OGA increased in the presence of UHMWPE not blended with Vitamin E. Vitamin E-stabilized UHMWPE induced a decrease of RANKL/OPG ratio compared to UHMWPE without Vitamin E, and the same effect was observed for Sclerostin, while DKK-1 was not significantly affected. In conclusion, Vitamin E stabilization of UHMWPE increased osteoblast response to oxidative stress, inducing a cellular mechanism aimed at cell survival. Vitamin E antioxidant effect influences the secretion of osteoimmunological factors, shifting the bone turnover balance toward bone protection stimuli. This suggests that Vitamin E-Stabilization of UHMWPE could contribute to reduction of oxidation-induced osteolysis and the consequent loosening of the prosthetic devices, therefore improving the longevity of total joint replacements.

Retears and complication rates after arthroscopic rotator cuff repair with scaffolds: a systematic review.

The goal of repairing rotator cuff injuries is an anatomical procedure without tension repair. Considering the high percentage of re-rupture after large and massive lesions repair, numerous surgical solutions have been proposed. The purpose of this systematic review was to present retears and complication rates following arthroscopic treatment of rotator cuff pathology with scaffolds. A systematic review of the existing literature was performed to identify all studies dealing with arthroscopic rotator cuff repair using scaffolds. Two independent investigators performed the research using MEDLINE, Scopus, Embase and Cochrane Databases (1950 to January 2018). The search terms used were "arthroscopic" OR "arthroscopy" AND "rotator cuff" AND "augmentation" OR "scaffold" OR "patch" OR "matrix" OR "xenograft" OR "allograft" OR "autograft". A total of 10 articles met our inclusion criteria. Mean age at surgery was 61.92 years and size lesion ranged from small-intermediate lesion (3-6 mm) to irreparable/massive lesion. In 19 (10.67%) cases surgery was performed on recurrent rotator cuff repair with failed previous repair. Mean follow-up was 24.70 months. On 178 shoulders repaired, 32 (17.97%) reported a retear. As regards complications rate a total of 18 (10.11%) were noted. In conclusion, this review shows arthroscopic rotator cuff repair with scaffold can be considered an effective and safe treatment particularly for large or masive rotator cuff lesions, potentially able to provide clinical improvement.

Arthroscopic treatment of osteochondral knee defects with resorbable biphasic synthetic scaffold: clinical and radiological results and long-term survival analysis.

PURPOSE: The aim of our study is to evaluate the long-term results in patients treated with a fully arthroscopic TruFit system for osteochondral lesions of the femoral condyle, analyzing the clinical and radiological outcomes, survival rate, complications, and correlations. METHODS: The study included all patients treated with the TruFit system with a full-thickness focal lesion of the knee cartilage (grade IV according to the ICRS classification), entirely arthroscopically with a minimum follow-up of five years. All patients were evaluated clinically prior to surgery (T0) and at two consecutive follow-ups (T1 36.4 ± 17.03 months and T2 101.63 ± 19.02 months), using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Hospital for Special Surgery Score (HSS). At the final follow-up, the magnetic resonance imaging (MRI) was evaluated by two orthopaedists using the magnetic resonance observation of cartilage repair tissue (MOCART) score. RESULTS: The sample was formed of 21 patients, of which 14 were males (67%) and 7 females (33%), with a mean age of 51.29 ± 10.70. Of the 21 patients, two underwent prosthetic knee replacement at 24 and 65 months, respectively. At T0, the HSS and the KOOS score were, respectively, 60.71 ± 11.62 and 57.71 ± 6.11. For both clinical values, a significant improvement was noted between T0 and T1 (p < 0.05) and between T0 and T2 (p < 0.05). At the final follow-up, the MOCART value was found to be 45.78 ± 5.27. CONCLUSIONS: The study results highlighted the safety and potential of the arthroscopic TruFit system procedure, which offered a good clinical outcome with stable results at long-term follow-up although we found no correlations between the MRI and clinical results.

Effect of multiple hereditary exostoses on sports activity in children.

OBJECTIVE: The purpose of this clinical case-control study was to assess the level of sports activity in children with hereditary multiple exostoses (HME) and to compare with the degree of physical activity in children of the same age without pathology. METHODS: A case-control study was designed. Cases were drawn from children with HME diagnosed on the basis of clinical and radiographic evaluation with an age less then 12 years. Controls were chosen from a group of children with the same age and a negative family history for HME. All patients and controls were completed with the help of parents using the following evaluations: Tegner Activity Level Scale and University of California Los Angeles (UCLA) activity scale. RESULTS: A total of 154 individuals participated (54 cases and 100 controls). In the case groups, the mean age was 9.07; the mean number of exostoses resulted 29.51, while the mean value of UCLA and Tegner score resulted respectively 6.04 and 5.09. In the controls, the mean age was 8.88; mean UCLA and Tegner resulted respectively 7.17 and 5.64. Comparing the two groups, the only difference was between UCLA score (p = 0.0053). Moreover, comparing the results between female children affected by HME and female controls, we found a significant difference as regards UCLA score (p = 0.0045). CONCLUSION: Children affected by HME reported lower sports activity, in particular as regards female patients. Moreover, physical activity is not correlated with any other independent factor leading different patients to a similar level of ability in performing sport. STUDY DESIGN: Level III - Case Control Study.

Vitamin E-stabilized UHMWPE: Biological response on human osteoblasts to wear debris.

UHMWPE doped with vitamin E was introduced to provide oxidation resistance upon sterilization, without affecting UHMWPE's mechanical properties. Particle-induced macrophage activation leads to periprosthetic bone resorption, requiring total joint replacements. During osteolysis, osteoblasts produce osteoimmunological factors such as RANKL and OPG, and the inhibitors of the Wnt pathway DKK-1 and Sclerostin. This study investigated in vitro how vitamin E-blended-UHMWPE wear debris might affect osteoblast-mediated osteolysis and the production of RANKL, OPG, Sclerostin and DKK-1, compared to conventional UHMWPE wear debris. Human osteoblastic SaOS2 cells were incubated with wear particles from Vitamin E doped and conventional UHMWPE and the gene expression and protein production of IL-6, RANKL, OPG, DKK-1, and Sclerostin was evaluated, RANKL, a bone erosion marker, was reduced, while OPG, a bone protective marker, were increased by the vitamin E-blended UHMWPE compared to conventional UHMWPE. Vitamin E doped UHMWPE reduced Sclerostin level, and partially affected DKK-1 production, thereby protecting against bone erosion. In conclusion, Vitamin E-blended UHMWPE induced an osteoimmunological response in bone cells that had positive effects on the osteolysis induced by wear debris, reducing aseptic loosening of the implants. In conclusion, this is the first study showing that Vitamin E-blended UHMWPE induced an osteoimmunological response in bone cells that positively affect the osteolysis induced by wear debris, thereby reducing the aseptic loosening of the implants.

Survival Analysis after Core Decompression in Association with Platelet-Rich Plasma, Mesenchymal Stem Cells, and Synthetic Bone Graft in Patients with Osteonecrosis of the Femoral Head.

Purpose The aim of this study was to report the rate of survivorship in patients with osteonecrosis of the femoral head treated with core decompression in association with mesenchymal stem cells (MSCs) implantation, platelet-rich plasma (PRP) injection, and synthetic bone graft. Methods We evaluated 24 hips in 16 patients, according to Ficat classification, treated by core decompression, injection of PRP and MSCs, and backfilling of the core tract with synthetic bone graft. Survivorship was estimated using Kaplan-Meier curves. Results The survivorship of core decompression in association with the procedure is 50% at 75 months of follow-up. The survival rate was 80% for patients in early stage and 28.6% for patients in advanced stage at 75 months. When we compared Kaplan-Meier survival curves of patients in stage III + IV and patients in stage I + II, we noticed that the survival functions are statistically different ( p < 0.05, log-rank test), particularly in stage I + II where we had a greater surviving core decompression, in comparison to patients in stage III + IV. Conclusion This technique is safe and good preliminary results were obtained in patients with early stages of the disease with no reported complications. Level of Evidence Level IV, therapeutic case series.

Efficacy of a single intra-articular injection of ultra-high molecular weight hyaluronic acid for hip osteoarthritis: a randomized controlled study.

BACKGROUND: Viscosupplementation with hyaluronic acid (HA) is increasingly used for the treatment of hip osteoarthritis (OA). The purpose of this study was to compare the efficacy of intra-articular injections of an ultra-high molecular weight viscosupplement (UHMW-HA, Fermathron S) with a medium molecular weight hyaluronan (MMW-HA, Hyalubrix 60) in hip OA. METHODS: Fifty-four patients with hip OA grade 3 on the Kellgren/Lawrence scale were randomized. All infiltrations were performed under ultrasound guidance. Evaluation was performed preoperatively and at 1, 3, 6 and 12 months after infiltration. Patients were clinically evaluated using Lequesne index, VAS and WOMAC score. RESULTS: Fifty patients, including 27 in the MMW-HA group and 23 in the UHMW-HA group, completed the follow-up. No significant difference was found between the two groups in terms of VAS, WOMAC or Lequesne index preoperatively or at 1, 3, 6 and 12 months after viscosupplementation. A stratified analysis was performed to study the development over time of Lequesne index of patients aged ≤ 55 years, > 55 and, ≤ 70 years and > 70 years and Lequesne index was different between the three age-stratified subgroups only in the MMW-HA group. The subgroup of older patients showed a higher Lequesne index than the subgroups of younger patients (p < 0.05). CONCLUSIONS: UHMW-HA is a safe and effective treatment for hip osteoarthritis. A single dose of UHMW-HA was as effective as two doses of MMW-HA resulting in similar reductions of pain and disability. STUDY DESIGN: Multicenter, independent, prospective, randomized controlled trial with level of evidence 1.

What Arthroscopic Skills Need to Be Trained Before Continuing Safe Training in the Operating Room?

The purpose of this study was to generate consensus among experienced surgeons on "what skills a resident should possess before continuing safe training in the operating room (OR)." An online survey of 65 questions was developed and distributed to surgeons in the European community. A total of 216 responded. The survey included 15 questions regarding generic and specific skills; 16 on patient and tissue manipulation, 11 on knowledge of pathology and 6 on inspection of e-anatomical structures; 5 methods to prepare residents; and 12 on specific skills exercises. The importance of each question (arthroscopic skill) was evaluated ranging from 1 (not important at all) to 6 (very important). Chi-square test, respondent agreement, and a qualitative ranking method were determined to identify the top ranked skills (p < 0.05). The top four of general skills considered important were "anatomical knowledge," "tissue manipulation," "spatial perception," and "triangulation" (all chi-square test > 134, p < 0.001, all excellent agreement > 0.85, and all "high priority" level). The top ranked 2 specific arthroscopic skills were "portal placement" and "triangulating the tip of the probe with a 30-degree scope" (chi-square test > 176, p < 0.001, excellent agreement, and assigned high priority). The online survey identified consensus on skills that are considered important for a trainee to possess before continuing training in the OR. Compared with the Canadian colleagues, the European arthroscopy community demonstrated similar ranking.

The impact of hereditary multiple exostoses on quality of life, satisfaction, global health status, and pain.

PURPOSE: The aim of the study was to evaluate quality of life (QOL), global health status, pain, and level of satisfaction in patients with hereditary multiple exostoses (HME), and to correlate the association between the severity of diseases and age, sex, number of surgical procedures, and number of exostoses. METHODS: The data of 50 patients with HME were retrospectively evaluated and recorded. QOL was evaluated with the Short-Form Health Survey (SF-12) questionnaire, the 12-Item General Health Questionnaire (GHQ-12), and Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q-SF); intensity of pain was measured using the visual analogue scale (VAS). The association of age, gender, pain, quality of life, number of exostoses, and number of surgical procedures were evaluated and correlated. RESULTS: Mean number of exostoses in our patient's cohort resulted 18.12 ± 8.60, and every patient underwent to a mean of 5.62 ± 5.74 surgical procedures for the exostoses. Mean VAS resulted 5.16 ± 2.90. Considering SF-12, mental (MCS) and physical (PCS) component resulted, respectively, 45.36 ± 10.76 and 38.73 ± 11.09, while GHQ-12 and Q-LES-Q-SF were 15.48 ± 4.70 and 45.28 ± 9.55, respectively. We found a significant positive correlation between the number of exostoses and the number of surgical procedures (p < 0.001), a significant positive correlation between the number of surgical procedures and GHQ-12 (p = 0.422) and VAS (p = 0.0011), and a negative correlation between the number of surgical procedures and PCS (p = 0.0257) and between age and GHQ-12 (p = 0.0385). CONCLUSIONS: We can conclude that HME impact on patient quality of life as measured by the MCS and PCS scores similar to the disability associated with osteoarthritis in the mental component and tumors or diabetes as regards the physical component. Moreover, we found no difference in patients' quality of life as regards number of exostoses, age, and surgical procedure, but we found that women have a worse response as regards the psychological side than men.

Effects of the pulsed electromagnetic field PST® on human tendon stem cells: a controlled laboratory study.

BACKGROUND: Current clinical procedures for rotator cuff tears need to be improved, as a high rate of failure is still observed. Therefore, new approaches have been attempted to stimulate self-regeneration, including biophysical stimulation modalities, such as low-frequency pulsed electromagnetic fields, which are alternative and non-invasive methods that seem to produce satisfying therapeutic effects. While little is known about their mechanism of action, it has been speculated that they may act on resident stem cells. Thus, the purpose of this study was to evaluate the effects of a pulsed electromagnetic field (PST®) on human tendon stem cells (hTSCs) in order to elucidate the possible mechanism of the observed therapeutic effects. METHODS: hTSCs from the rotator cuff were isolated from tendon biopsies and cultured in vitro. Then, cells were exposed to a 1-h PST® treatment and compared to control untreated cells in terms of cell morphology, proliferation, viability, migration, and stem cell marker expression. RESULTS: Exposure of hTSCs to PST® did not cause any significant changes in proliferation, viability, migration, and morphology. Instead, while stem cell marker expression significantly decreased in control cells during cell culturing, PST®-treated cells did not have a significant reduction of the same markers. CONCLUSIONS: While PST® did not have significant effects on hTSCs proliferation, the treatment had beneficial effects on stem cell marker expression, as treated cells maintained a higher expression of these markers during culturing. These results support the notion that PST® treatment may increase the patient stem cell regenerative potential.

Lipogems Product Treatment Increases the Proliferation Rate of Human Tendon Stem Cells without Affecting Their Stemness and Differentiation Capability.

Increasing the success rate of rotator cuff healing remains tremendous challenge. Among many approaches, the possibility of activating resident stem cells in situ, without the need to isolate them from biopsies, could represent valuable therapeutic strategy. Along this line, it has been recently demonstrated that lipoaspirate product, Lipogems, contains and produces growth-factors that may activate resident stem cells. In this study, human tendon stem cells (hTSCs) from the rotator cuff were cocultured in a transwell system with the Lipogems lipoaspirate product and compared to control untreated cells in terms of cell proliferation, morphology, stem cell marker and VEGF expression, and differentiation and migration capabilities. Results showed that the Lipogems product significantly increases the proliferation rate of hTSCs without altering their stemness and differentiation capability. Moreover, treated cells increase the expression of VEGF, which is crucial for the neovascularization of the tissue during the healing process. Overall, this study supports that directly activating hTSCs with the Lipogems lipoaspirate could represent a new practical therapeutic approach. In fact, obtaining a lipoaspirate is easier, safer, and more cost-effective than harvesting cells from tendon or bone marrow biopsies, expanding them in GMP facility and then reinjecting them in the patient.

Effectiveness of Vitamin-E-Doped Polyethylene in Joint Replacement: A Literature Review.

Since polyethylene is one of the most frequently used biomaterials, such as in bearing components in joint arthroplasty, strong efforts have been made to improve the design and material properties over the last decades. Antioxidants, such as vitamin-E, seem to be a promising alternative to further increase durability and reduce polyethylene wear and degradation in the long-term. Nevertheless, even if several promising in vitro results are available, there is yet no clinical evidence that vitamin-E polyethylenes show these advantages in vivo. The aim of this paper was to provide a comprehensive overview on the current knowledge regarding the biological and mechanical proprieties of this biomaterial, underlying the in vitro and in vivo evidence for effectiveness of vitamin-E-doped polyethylene in joint arthroplasty.

Reliability of forced internal rotation and active internal rotation to assess lateral instability of the biceps pulley.

PURPOSE: the aim of this study was to investigate the relationship between positive painful forced internal rotation (FIR) and lateral pulley instability in the presence of a pre-diagnosed posterosuperior cuff tear. The same investigation was conducted for painful active internal rotation (AIR). METHODS: a multicenter prospective study was conducted in a series of patients scheduled to undergo arthroscopic posterosuperior cuff repair. Pain was assessed using a visual analog scale (VAS) and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) was administered. The VAS score at rest, DASH score, and presence/absence of pain on FIR and AIR were recorded and their relationships with lesions of the lateral pulley, cuff tear patterns and shape of lesions were analyzed. RESULTS: the study population consisted of 115 patients (mean age: 55.1 years) recruited from 12 centers. The dominant arm was affected in 72 cases (62.6%). The average anteroposterior extension of the lesion was 1.61 cm. The mean preoperative VAS and DASH scores were 6.1 and 41.8, respectively. FIR and AIR were positive in 94 (81.7%) and 85 (73.9%) cases, respectively. The lateral pulley was compromised in 50 cases (43.4%). Cuff tears were partial articular in 35 patients (30.4%), complete in 61 (53%), and partial bursal in 19 (16.5%). No statistical correlation between positive FIR or AIR and lateral pulley lesions was detected. Positive FIR and AIR were statistically associated with complete lesions. Negative FIR was associated with the presence of partial articular tears. CONCLUSIONS: painful FIR in the presence of a postero-superior cuff tear does not indicate lateral pulley instability. When a cuff tear is suspected, positive FIR and AIR are suggestive of full-thickness tear patterns while a negative FIR suggests a partial articular lesion. LEVEL OF EVIDENCE: level I, validating cohort study with good reference standards.

Revision reverse shoulder arthroplasty in failed shoulder arthroplasties for rotator cuff deficiency.

PURPOSE: the aim of this systematic literature review is to report clinical outcomes of reverse shoulder arthroplasty (RSA) used as a revision surgery following failure of the primary implant due to rotator cuff insufficiency. METHODS: a systematic review was performed using the following key words: revision, shoulder, rotator cuff deficiency, outcome assessment, treatment outcome, complications. Studies eligible for inclusion in the review were clinical trials investigating patients in whom a primary shoulder arthroplasty implant with an incompetent rotator cuff was replaced with a reverse shoulder prosthesis. RESULTS: nine articles were identified and further reviewed. The results refer to a total of 226 shoulders that were treated with RSA as revision surgery. The patients in the studies had a mean age ranging from 64 to 72 years and the longest follow-up was 3.8 years. Improvements in function and reduction of pain were shown by many studies, but the mean Constant score ranged from 44.2 to 56. High complication rates (of up to 62%) were recorded, and a mean reoperation rate of 27.5%. CONCLUSIONS: RSA as revision surgery for patients with rotator cuff deficiency is a valid option, and often the only solution available, but it should be limited to elderly patients with poor function and severe pain. LEVEL OF EVIDENCE: level IV, systematic review of level I-IV studies.

History of rotator cuff surgery.

PURPOSE: Rotator cuff surgery is a rapidly evolving branch in orthopaedics, which has raised from a minor niche to a fully recognized subspecialty. This article summarizes its history, examining the development of its key principles and the technical advancements. METHODS: Literature was thoroughly searched, and few senior surgeons were interviewed in order to identify the significant steps in the evolution of rotator cuff surgery. RESULTS: A wide variety of surgical options is available to reduce pain and restore function after rotator cuff tears. Rotator cuff repair surgical techniques evolved from open to arthroscopic and are still in development, with new fixation techniques and biological solutions to enhance tendon healing being proposed, tested in laboratory and in clinical trials. Although good or excellent results are often obtained, there is little evidence that the results of rotator cuff repair are improving with the decades. An overall high re-tear rate remains, but patients with failed rotator cuff repairs can experience outcomes comparable with those after successful repairs. CONCLUSIONS: Rotator cuff repair techniques evolve at a fast pace, with new solutions often being used without solid clinical evidence of superiority. It is necessary to conduct high-level clinical studies, in which data relating to anatomical integrity, patient self-assessed comfort and function, together with precise description of patient's condition and surgical technique, are collected. LEVEL OF EVIDENCE: IV.