The Current State of Meniscus Replacements.

PURPOSE OF REVIEW: The field of meniscus replacement is changing continuously, with new devices emerging and others disappearing from the market. With the current tendency to preserve the knee joint, meniscus implants may become more relevant than ever. The purpose of this review is to provide an overview of the current state of partial and total meniscus replacements that have been developed beyond the academic phase. The available clinical and pre-clinical data is evaluated, and omissions are identified. RECENT FINDINGS: Recent systematic reviews have shown a lack of homogenous clinical data on the CMI and Actifit meniscal scaffolds, especially regarding long-term performance without concomitant surgical interventions. Clinical studies on the medial total meniscus prostheses NUsurface and Artimis are ongoing, with the NUsurface being several years ahead. New techniques for meniscus replacement are rapidly developing, including the Artimis lateral meniscus prosthesis and the MeniscoFix 3D-printed scaffold. All evaluated clinical studies point towards improved clinical outcomes after implantation of partial and total meniscus replacements. Long-term data on survival and performance is of low quality for CMI and Actifit and is unavailable yet for NUsurface and Artimis. It is of major importance that future research focuses on optimizing fixation methods and identifying the optimal treatment strategy for each patient group. New techniques for total and partial replacement of the medial and lateral meniscus will be followed with interest.

Temporomandibular joint prosthesis as treatment option for mandibular condyle fractures: a systematic review and meta-analysis.

The aim of this study was to perform a systematic review of the literature on the temporomandibular joint (TMJ) prosthesis as a treatment option after mandibular condyle fracture. Three databases were searched (PubMed, Embase, Cochrane Library) and 2670 unique papers were identified. A total of 337 studies were included (121 case reports, 89 case series, and 127 cohort/clinical studies). In total 14,396 patients and 21,560 prostheses were described. Of the 127 cohort or clinical studies, 100 (79%) reported inclusion criteria, 54 (43%) reported exclusion criteria, and 96 (76%) reported the inclusion period. The base population from which patients were recruited was reported in 57 studies (45%). The reason for TMJ prosthesis implantation was reported for 4177 patients (29.0%). A history of condylar fracture was present in 83 patients (2.0%); a history of mandibular trauma was present in 580 patients (13.9%). The meta-analysis showed a pooled prevalence of condylar fracture of 1.6% (95% confidence interval 0.9-2.4%) and a pooled prevalence of trauma or condylar fracture of 11.3% (95% confidence interval 7.1-16.0%). Heterogeneity was highly significant (P < 0.001). The TMJ prosthesis appears to be reserved for patients with persistent pain, bony or fibrous ankylosis, or osteomyelitis after primary closed or open treatment of fractures of the mandibular condyle.

The first-generation anatomical medial meniscus prosthesis led to unsatisfactory results: a first-in-human study.

PURPOSE: The purpose of this first-in-human study was to evaluate the effect of a polycarbonate anatomical meniscus prosthesis system, including the surgical procedure, on knee pain and describe potential adverse events in patients with post-meniscectomy pain syndrome. METHODS: Eleven patients with post-meniscectomy pain syndrome and limited underlying cartilage damage were enrolled in the study. Five received a medial polycarbonate urethane meniscus prosthesis which was clicked onto 2 titanium screws fixated at the native horn attachments on the tibia. The KOOS score was planned to be collected at baseline and at 3, 6, 12 and 24 months following the intervention including radiographs at 6, 12 and 24 months. MRI scans were repeated after 12 and 24 months. RESULTS: The surgical technique to select an appropriately sized implant and correct positioning of the fixation screws and meniscus prosthesis onto the tibia was demonstrated to be feasible and reproducible. Inclusion stopped after 5 patients because of serious adverse device-related events. All patients reported knee joint stiffness and slight effusion in their knee at 6 months follow-up. In 3 patients the implant was removed because of implant failure and in 1 patient the implant was removed because of persistent pain and extension limitation. In none of the patients did the KOOS score improve in the first 6 months after surgery. However, in the patient who still has the implant in situ, PROMs started to improve 1 year after surgery and this improvement continued through 2 years of follow-up. The KOOS Pain, symptoms and ADL were close to the maximal 100 points. KOOS QoL and sport did improve but remained suboptimal. CONCLUSION: This first version of the meniscus prosthesis led to impaired knee function and failed in four out of five patients. The patients where the prosthesis was removed were salvable and the PROMs returned to pre-study levels. The results in the patient where the device is still in place are promising. LEVEL OF EVIDENCE: Level II.

Harvesting anterior iliac crest or calvarial bone grafts to augment severely resorbed edentulous jaws: a systematic review and meta-analysis of patient-reported outcomes.

The aim of this systematic review was to compare patient-reported outcomes after harvesting calvarial or anterior iliac crest bone grafts to repair severe jaw defects and enable implant placement. The MEDLINE, Embase, Cochrane Central Register of Controlled Trials databases, and OpenGrey were searched for studies on patient satisfaction, pain, disturbances in daily functioning, sensory alterations, donor site aesthetics, and complication rates. Of the 1946 articles identified, 43 reporting 40 studies fulfilled the inclusion criteria; the studies were one randomized controlled clinical trial, one retrospective controlled clinical trial, and 23 prospective and 15 retrospective cohort studies. A meta-analysis of two studies (74 patients) showed no difference in satisfaction (mean difference (MD) - 0.13, 95% confidence interval (CI) - 1.17 to 0.92; P = 0.813) or postoperative pain (directly postoperative: MD -2.32, 95% CI -5.20 to 0.55, P = 0.113; late postoperative: MD -0.01, 95% CI -0.14 to 0.11, P = 0.825) between donor sites. However, the level of evidence is limited, due to the retrospective, non-randomized design of one study. Postoperative gait disturbances were highly prevalent among the anterior iliac crest patients (28-100% after 1 week). The incidence rates of sensory disturbances and other complications were low, and the donor site aesthetic outcomes were favourable for both graft types. To conclude, harvesting bone grafts from the calvarium or anterior iliac crest to augment the severely resorbed edentulous jaw results in similar patient satisfaction. However, the findings for postoperative pain and disturbances in daily living suggest a trend in favour of calvarial bone grafts if harvested using an adjusted technique.

[Antithrombotics: backgrounds with haemostasis and antithrombotic therapy]. / Antitrombotica: achtergronden bij stolling en antistolling.

The clinical guidelines on antithrombotics, published by the Dutch Institute of Expertise for Oral Healthcare, give advice on policy to be followed in cases of dental procedures involving bleeding. The guidelines allow room for professional assessment of bleeding risks, for which background knowledge about haemostasis, thrombosis and antithrombotic processes is necessary. Normal haemostasis can be divided in several steps: vasoconstriction, primary haemostasis by aggregation of thrombocytes, and secondary haemostasis by the formation of fibrin out of coagulation factors. In the case of thrombosis, a blood clot forms inside a blood vessel, causing obstruction of blood flow to the underlying tissue. Various antithrombotics are prescribed for the prevention and treatment of thrombosis. Thrombocyte aggregation inhibitors only have an effect on primary haemostasis. Vitamin K antagonists influence secondary haemostasis by lowering the production of several coagulation factors. The direct oral anticoagulants have an immediate effect on an activated coagulation factor, and are currently prescribed in large quantities [in the Netherlands]. Low-molecular-weight heparin also inhibits activated coagulation factors, but is not used for long-term antithrombotic therapy since it is administrated subcutaneously.

[Using the new clinical guidelines on antithrombotics in the dental practice]. / Toepassen van nieuwe richtlijn 'Antitrombotica' in de mondzorgpraktijk.

A 64-year-old man has deep caries in tooth 37 without acute pain; extraction is indicated, however. According to his list of medications, he takes the antithrombotics apixaban and clopidogrel. Or: a 78-year-old woman has upper and lower dentures that don't function well, and she experiences retention problems. Implant-bearing upper and lower dentures on 4 and 2 implants, respectively, are indicated. The patient takes acenocoumarol and reports that the clotting time value of her blood (INR) sometimes fluctuates. The clinical guidelines 'Dental procedures in patients using antithrombotic medication', which recently appeared, offer oral healthcare providers recommendations for reducing the risk of bleeding while observing the risk of thrombosis. These guidelines by the Dutch Institute of Expertise for Oral Healthcare replace the previous guidelines from 2012. The recommendations are up to date with current practice in the Netherlands and take into account all antithrombotics patients may currently use in an outpatient setting. Furthermore, the responsibilities of the oral healthcare providers and the agreements with thrombosis services are formalised in these guidelines.

Retreatment of multiple failing maxillary implants after full arch rehabilitation: a retrospective, observational cohort study.

The aim of this study was to assess implant retreatment in a group of patients whose maxillary implants were all failing after full arch rehabilitation. Treatment involved implant removal, augmentation, and placement of an overdenture supported by four to six implants. All consecutive patients referred between 2008 and 2018, following multiple late implant failures in the rehabilitated maxilla, were included in the study. Seventy implants in 15 patients were evaluated at 3.3 ± 2.5 years (range 1.1-8.6 years) after loading. Implant survival, complications, clinical parameters, marginal bone loss, and patient-related outcome measures were recorded at the time of evaluation. Overall implant survival was 95.7%. Three implant failures occurred within the first year of function. Marginal bone loss was 0.32 ± 0.46 mm; pocket probing depth was 4.55 ± 1.59 mm. Plaque, calculus, inflammation, and bleeding were hardly seen (median index score 0). Patients scored their satisfaction with their overdentures as high (mean overall score 8.7 ± 1.2, maximum 10). Chewing soft and tough food was scored as 'good' and hard food as 'moderate'. The mean Oral Health Impact Profile score was 29.5 ± 33.3. It can be concluded that the replacement of multiple failing implants in an edentulous maxilla after bone augmentation is a safe and predictable treatment procedure when applied as an implant-supported overdenture.

Biodegradable versus titanium osteosynthesis in maxillofacial traumatology: a systematic review with meta-analysis and trial sequential analysis.

Titanium osteosynthesis is currently the fixation system of choice in maxillofacial traumatology. Biodegradable osteosynthesis systems have the ability to degrade in the human body. The aim of this study was to conduct a systematic review, with meta- and trial sequential analyses, to assess the efficacy and morbidity of biodegradable versus titanium osteosynthesis after maxillofacial trauma. MEDLINE, Embase, and CENTRAL were searched for randomized controlled trials and prospective and retrospective controlled studies. Five time periods were studied: perioperative, short-term (0-4 weeks), intermediate (6-12 weeks), long-term (>12 weeks), and overall follow-up. After screening 3542 records, 24 were included. All had a high risk of performance and detection bias due to the nature of the interventions. Meta-analysis showed no differences in efficacy or morbidity between biodegradable and titanium osteosynthesis. The risk of perioperative screw breakage was significantly higher (risk ratio 17.13, 95% confidence interval 2.19-34.18) and the symptomatic plate removal rate lower in the biodegradable group (risk ratio 0.11, 95% confidence interval 0.02-0.57), which was confirmed by the trial sequential analysis. The quality of evidence ranged from very low to moderate. Based on the narrative review and meta-analyses, current evidence shows that biodegradable osteosynthesis is a viable alternative to titanium osteosynthesis when applied in the treatment of maxillofacial trauma, with similar efficacy but significantly lower symptomatic plate removal rates. Perioperative screw breakage occurred significantly more often in the biodegradable group compared to the titanium group.

Complications of locking and non-locking plate systems in mandibular fractures.

This systematic review and meta-analysis was performed to critically assess the methodological quality of the existing systematic reviews, and to evaluate the postoperative complications of the mandibular fractures treated with locking and non-locking plate systems. An electronic search was conducted in PubMed, Embase, Web of Science, Cochrane library's electronic databases and grey literate using a combination of Medical Subject Heading terms and key words, until September 2018. No restrictions were applied to the search strategy. In total, three relevant systematic reviews were included, and the quality of these studies was low. A total of 33 studies (20 randomized studies and 13 non-randomized studies) were included in this systematic review, and 16 of them were included in meta-analysis. Most of the included randomized studies had an unclear risk of bias (Cochrane Collaboration); the quality of non-randomized studies ranged between 6 and 17 (Methodological Index for Non-Randomized Studies - MINORS). Based on the results of our meta-analysis, we conclude that locking plates are superior only with respect to the need for mandibulomaxillary fixation (MMF) in the early postoperative period.

Morbidity of anterior iliac crest and calvarial bone donor graft sites: a 1-year randomized controlled trial.

Autogenous bone graft harvesting is still commonly considered the gold standard for the reconstruction of a severely resorbed maxillary alveolar ridge; however, the preferred donor site remains a subject of debate. This study compared the morbidity of calvarial and iliac crest donor sites after harvesting. Twenty edentulous patients with an insufficient volume of maxillary bone for reliable implant placement were assigned randomly to either calvarial (n=10) or anterior iliac crest (n=10) bone harvesting groups. All patients underwent a maxillary sinus floor elevation procedure combined with widening of the alveolar process using buccal bone blocks. Donor site morbidity was assessed before, during, and at 1year after the surgery through patient questionnaires, physical examination, and medical records. No perioperative complications occurred. The anterior iliac crest group reported minor postoperative pain after harvesting. The scars after calvaria harvesting were significantly longer (P=0.003), but this was not bothersome for the group of patients. Long-term pain was negligible and satisfaction was high in both groups. Both the calvaria and anterior iliac crest are associated with low long-term donor site morbidity and high patient satisfaction. Thus, patient-centred decision-making is appropriate when selecting the preferred harvesting method for that patient.

Comparison of the long-term clinical performance of a biodegradable and a titanium fixation system in maxillofacial surgery: A multicenter randomized controlled trial.

BACKGROUND: Biodegradable fixation systems could reduce or eliminate problems associated with titanium removal of implants in a second operation. AIM: The aim of this study was to compare the long-term (i.e. >5 years postoperatively) clinical performance of a titanium and a biodegradable system in oral and maxillofacial surgery. MATERIALS AND METHODS: The present multicenter Randomized Controlled Trial (RCT) was performed in four hospitals in the Netherlands. Patients treated with a bilateral sagittal split osteotomy (BSSO) and/or a Le Fort-I osteotomy, and those treated for fractures of the mandible, maxilla, or zygoma were included from December 2006 to July 2009. The patients were randomly assigned to either a titanium (KLS Martin) or a biodegradable group (Inion CPS). RESULTS: After >5 years postoperatively, plate removal was performed in 22 of the 134 (16.4%) patients treated with titanium and in 23 of the 87 (26.4%) patients treated with the biodegradable system (P = 0.036, hazard ratio (HR) biodegradable (95% CI) = 2.0 (1.05-3.8), HR titanium = 1). Occlusion, VAS pain scores, and MFIQ showed good and (almost) pain free mandibular function in both groups. CONCLUSION: In conclusion, the performance of the Inion CPS biodegradable system was inferior compared to the KLS Martin titanium system regarding plate/screws removal in the abovementioned surgical procedures. TRIAL REGISTRATION: http://controlled-trials.com ISRCTN44212338.

[Recent increase in simple extractions in OMF-surgeries in the Netherlands studied]. / Recente toename van reguliere extracties in mka-chirurgie onderzocht.

Tooth extraction is a treatment that can be carried out by general dental practitioners. It is suspected that the number of referrals to OMF-surgeons for simple tooth extractions has increased in the Netherlands in recent years. In a study, the health records of 2 groups of outpatients treated at the Oral and Maxillofacial Surgery department of a university medical centre between 1996 and 2014 were investigated. Patients who had undergone tooth extractions were included. The complexity of the tooth extractions was analyzed according to 4 criteria. The results of the study show a significant increase in simple tooth extractions by OMF surgeons in 2014 in comparison with 1996. The complexity of the total number of tooth extractions in 2014 was lower than in 1996. Reasons for these results could not be unambiguously determined. Possible significant aspects are the risk of per-operative complications, insufficient affinity of general dental practitioners with tooth extractions or financial considerations on the part of both the general dental practitioners and the patients.

[The 3D-printed dental splint: a valuable tool in the surgical treatment of malocclusion after polytrauma]. / De driedimensionaal geprinte dentale spalk bij chirurgische behandeling van malocclusie na polytrauma.

A 22-year old male was referred to the Department of Oral and Maxillofacial Surgery of a university clinic 2 months after he had sustained multiple traumatic injuries abroad because of an anterior malocclusion. The malocclusion was the sequel of an unrecognised, untreated, already consolidated paramedian mandibular fracture on the right and a fracture of the contralateral mandibular angle on the left. Preoperatively, a cobalt-chrome 3D-printed dental splint was prepared. Surgical correction of the malocclusion was carried out by segmental osteotomies of the mandible at the original fracture sites. This involved a vertical paramedian osteotomy on the right side and a unilateral sagittal split osteotomy on the left mandibular angle side. The mandibular segment was mobilised in the correct occlusion with the aid of the 3D-printed dental splint. The splint was fixed to the teeth with dental composite. The custom made 3D-printed dental splint is considered a promising procedural innovation in oral and maxillofacial surgery.

In vitro degradation of a biodegradable polyurethane foam, based on 1,4-butanediisocyanate: a three-year study at physiological and elevated temperature.

Biodegradable polyesterurethanes (PUs) may be used as scaffold materials for tissue regeneration applications, because of their excellent mechanical properties. In this study, the degradation of highly porous PU foams was evaluated in vitro. The PU had amorphous soft segments of DL-lactide/epsilon-caprolactone and uniform hard segments, synthesized from 1,4-butanediisocyanate and butanediol. The foams were degraded for 3 years in a Sörensen buffer solution (pH 7.4) at 37 and 60 degrees C. Dimensions of the foams, intrinsic viscosity, mass loss, thermal properties, and composition of the remaining material were evaluated. Copolyester (CP) foams of DL-lactide/epsilon-caprolactone served as controls. The PU foams kept their dimensions for 20 weeks at 37 degrees C, whereas CP foams collapsed after 3 weeks. PU mass loss reached a maximum of 80% at both 37 and 60 degrees C. CP mass loss reached 99.9% at 60 degrees , and 92% at 37 degrees C after 3 years. The degradation processes at 37 and 60 degrees C are initially the same, but eventually degradation products with different thermal properties are being formed. (1)H NMR studies showed that the hard urethane segments of the PU do not degrade in vitro at pH 7.4. It was concluded that the PU material has favorable characteristics for a scaffold material. Compared to long-term in vivo results of the same PU these in vitro results are not representative for the in vivo situation and therefore total resorption has to be investigated in long-term in vivo studies.

In vivo resorption of a biodegradable polyurethane foam, based on 1,4-butanediisocyanate: a three-year subcutaneous implantation study.

Degradable polyurethanes (PUs), based on aliphatic diisocyanates, can be very useful in tissue regeneration applications. Their long-term in vivo degradation has not been extensively investigated. In this study a biodegradable PU with copolyester soft segments of DL-lactide/epsilon-caprolactone and hard segments synthesized from 1,4-butanediisocyanate was evaluated with regard to tissue response during degradation and, ultimately, the resorption of the material. Highly porous PU foam discs were subcutaneously implanted in rats and rabbits for intervals up to 3 years. A copolymer foam of DL-lactide and epsilon-caprolactone served as a control. The foams, the surrounding tissues and the draining lymph nodes were evaluated with light and electron microscopy. In the first stages of degradation the number of macrophages and giant cells increased. As the resorption stage set in their numbers gradually decreased. Electron microscopy showed macrophages containing pieces of PU. The size of the intracellular PU particles diminished and cells containing these remnants gradually disappeared after periods from 1 to 3 years. After 3 years an occasional, isolated macrophage with biomaterial remnants could be traced in both PU and copolymer explants. Single macrophages with biomaterial remnants were observed in the lymph nodes between 39 weeks and 1.5 years following implantation. It is concluded that the PU foam is biocompatible during degradation. After 3 years PU samples had been resorbed almost completely. These results indicate that the PU foam can be safely used as a biodegradable implant.

A long-term in vitro biocompatibility study of a biodegradable polyurethane and its degradation products.

The biological safety of degradation products from degradable biomaterials is very important. In this study a new method is proposed to test the cytotoxicity of these degradation products with the aim to save time, laboratory animals, and research funds. A biodegradable polyurethane (PU) foam was subjected to this test method. The PU had soft segments of DL-lactide/epsilon-caprolactone and hard segments synthesized from butanediol and 1,4-butanediiosocyanate. Copolymer foams without urethane segments, consisting of DL-lactide/epsilon-caprolactone, were tested as well. Accumulated degradation products were collected by degrading the foams in distilled water at 60 degrees C up to 52 weeks. Cell-culture medium was prepared from powder medium with this water. In different tests the cytotoxicity of this medium was established. The first signs of cytotoxicity were observed after 3-5 weeks of degradation. This accounts for both materials and reestablishes the good short-term biocompatibility of these materials. The PU showed more toxicity toward the end stages of degradation in comparison with the copolymer. This is probably related to the accumulation of degradation products of the urethane segments. In the in vivo situation the degradation of the PU and the metabolism and excretion of degradation products may differ. Therefore, long-term in vivo studies will have to establish whether these in vitro results are representative for the in vivo behavior of the degrading PU.

An animal model for oroantral communications: a pilot study with Göttingen minipigs.

A pilot study was performed to investigate whether the Göttingen minipig is a suitable animal model for creating and closing oroantral communications (OACs) and to test whether these defects can be closed with a biodegradable polyurethane (PU) foam. In three adult minipigs, an OAC was created on both sides of the maxilla. The left side was closed by a standard surgical buccal flap procedure, the right side by applying a PU foam. The pigs were killed after two weeks, one month and three months, respectively. Postmortem and histological examination showed that an OAC was created in only one of six cases. In the remaining cases, the infraorbital canal was perforated instead of the floor of the maxillary sinus. It was concluded that the Göttingen minipig is not a suitable animal model for OAC investigations. As a result, the closure of OACs with a biodegradable PU could not be evaluated.

Short-term in vitro and in vivo biocompatibility of a biodegradable polyurethane foam based on 1,4-butanediisocyanate.

In this study short-term in vitro and in vivo biocompatibility apects of a biodegradable polyurethane (PU) foam were evaluated. The PU consists of hard urethane segments and amorphous soft segments based on a copolyester of dl-lactide and epsilon-caprolactone. The urethane segments are of uniform length and synthesized with 1,4-butanediisocyanate. The foam has good mechanical properties and will be used for tissue regeneration applications. Degradation tests were carried out in a buffer solution for twelve weeks. Cytotoxicity was determined using extract and direct contact test methods with incubation periods varying form 24 to 72 h. The foam was implanted subcutaneously for one, four and twelve weeks and the tissue response to the material was histologically evaluated. In vitro, the mass loss was 3.4% after twelve weeks. In the cytotoxicity tests the PU caused no abnormal growth behaviour, nor morphological changes or inhibition in metabolic activity. The in vivo studies showed no toxic tissue response to the PU. Connective tissue ingrowth, accompanied by vascular ingrowth was complete at twelve weeks. In vivo degradation had started within four to twelve weeks. In conclusion, the PU shows a good in vitro and in vivo biocompatibility in these short-term experiments.

Long-term functional outcome of mandibular reconstruction with stainless steel AO reconstruction plates.

Mandibular continuity defects are usually reconstructed with bone grafts. However, factors associated with the tumour and the patient can still be reasons to choose reconstruction plates. The aim of this study was to find out the results of mandibular reconstructions with stainless steel AO reconstruction plates after a long follow-up period. The records of 36 patients were reviewed for personal data and the history of disease, treatment and complications. Patients with failed reconstructions were compared with those in whom the procedure had been successful. Patients and surgeons gave their opinion on the functional and cosmetic results. The mean follow-up was 39 months (range 4-99); 4 patients were withdrawn because they developed early recurrent disease and in 17 patients the reconstruction failed. We found no significant differences between the successful and the failed group. Fourteen patients could be evaluated for functional outcome, 10 of whom were totally or satisfactorily rehabilitated. Therefore, stainless steel reconstruction plates can be used in patients when other options are inappropriate.