Clinical Outcomes of Isolated Polyethylene Exchange Versus Full Component Revision for the Management of Instability Following Total Knee Arthroplasty.

BACKGROUND: Instability following total knee arthroplasty (TKA) is a common cause for revision. Isolated polyethylene exchange (IPE) can be performed to increase knee joint stability, but results have been mixed. The purpose of this study was to compare the survivorship and patient-reported outcomes of patients undergoing revision TKA for instability with IPE versus full component revision. METHODS: We reviewed 280 primary TKAs undergoing revision TKA for instability. There were 181 knees that underwent revision with IPE, compared to 99 knees treated with full component revision. The mean follow-up was 32.8 months (range, 24.8 to 82.5). Patient demographics, radiographic parameters, prosthesis constraints, reoperations for instability, and patient-reported outcomes were compared. RESULTS: The survivorship for instability was significantly higher at 2 years (99 versus 92%, P = .024) and 5 years (94 versus 84%, P = .024) for patients undergoing full component revision. Although there was no difference in Knee Injury and Osteoarthritis Outcome Score for Joint Replacements and Veterans RAND 12 physical component scores between the 2 groups at 6 weeks, 1 year, and 2 years after surgery, full revision patients reported greater pain relief (P = .006) and greater improvements in Veterans RAND 12 physical component scores (P = .027) at 1 year and Knee Injury and Osteoarthritis Outcome Score for Joint Replacements scores at 2 years (P = .017) compared to IPE patients. Men were associated with an increased risk for recurrent instability following IPE (hazard ratio 3.3, 95% confidence interval: [1.0 to 10.6]). CONCLUSIONS: Isolated polyethylene exchange was not as reliable or durable compared to full component revision for the management of postoperative instability. These procedures should only be reserved in cases with competent collaterals and when component position, offset, and rotation are optimized.

Aseptic Loosening at the Tibia in Total Knee Arthroplasty: A Function of Cement Mantle Quality?

BACKGROUND: Aseptic loosening remains one of the leading causes for failure of total knee arthroplasty (TKA). We sought to identify early radiographic measures that may associate with aseptic tibial component loosening, emphasizing systematic evaluation of the cement mantle. METHODS: All TKA revisions from 2007 to 2015 with the primary indication of tibial aseptic loosening were identified using in an institutional implant retrieval database. After exclusion criteria, 61 TKAs comprised the study group. A matched control group of 59 TKAs that had not failed at a minimum of 3 years was identified for comparison. Radiographic analysis on all 6-week postoperative radiographs included angulation of components, cement penetration depth, and presence of radiolucency at the implant-cement and bone-cement interfaces. Groups were compared with Student's t-test, chi-squared test, and Mann-Whitney U-test. A final multivariable logistic regression model was formed for the outcome of aseptic loosening. RESULTS: On multivariable analysis, failure was associated with a greater number of zones with cement penetration <2 mm (5.6 vs 3.4 zones, odds ratio [OR] 1.89, P < .001), increasing percent involvement of radiolucency at the implant-cement interface (8.7% vs 3.1%, OR = 1.15, P = .001), and increased varus alignment of the tibial component (1.5° vs 0°, OR = 1.35, P = .014). A greater number of zones with a radiolucent line at the bone-cement interface did not significantly associate (1.1 vs 0.3, P = .091). CONCLUSION: Our results suggest that radiographic indicators of poor cement mantle quality associate with later aseptic loosening. This emphasizes the need for surgeons to perform careful cement technique in order to reduce the risk of TKA failure. LEVEL OF EVIDENCE: III (Case-control).

Adverse Local Tissue Reaction due to Mechanically Assisted Crevice Corrosion Presenting as Late Instability Following Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND: Mechanically assisted crevice corrosion (MACC) at modular junctions can cause a spectrum of adverse local tissue reactions (ALTRs) in patients who have undergone total hip arthroplasty (THA). The purpose of this study is to describe the presentation, treatments, and related complications of a cohort of patients presenting with late instability following metal-on-polyethylene THA due to underlying MACC and ALTR. METHODS: This multicenter retrospective case series presents 17 patients (12 women, mean age 62.6, range 42-73) presenting with late instability secondary to ALTR and MACC. All patients had a metal (Cobalt Chrome)-on-polyethylene bearing surface. Patients experienced a mean 2.7 dislocations (range 1-6) at mean 4.3 years (range 0.4-17.0) following their index surgery. Serum metal levels (n = 12) demonstrated a greater elevation of cobalt (mean 6.9, range 0.13-20.88 ng/mL) than chromium (mean 1.9, range 0.13-3.23 ng/mL). RESULTS: Patients were revised for instability at a mean of 6.8 years (range 2.1-19.4) following their index surgery. ALTR was encountered in every case and the modular head-neck junction demonstrated visible corrosion. An exchange of the CoCr head to a ceramic head with a titanium sleeve and placement of a constrained liner was performed for a majority of patients (n = 15, 88.2%). Five patients (29.4%) had complications postoperatively including peroneal palsy (n = 2), periprosthetic joint infection (n = 2), and ALTR recurrence (n = 1). CONCLUSION: Recurrent instability in the setting of otherwise well-positioned THA components and without another obvious cause should raise concern for ALTR as a potential underlying etiology.

Magnetic Solid-Phase Extraction Based on Poly 4-Vinyl Pyridine for HPLC-FLD Analysis of Naproxen in Urine Samples.

A magnetic solid phase extraction technique followed by liquid chromatography with a fluorescence detector for naproxen analysis in human urine samples was developed. The method includes the extraction of naproxen with a magnetic solid synthetized with magnetite and poly 4-vinylpriridine, followed by the magnetic separation of the solid phase and desorption of the analyte with methanol. Under optimal conditions, the linear range of the calibration curve was 0.05-0.60 µg L-1, with a limit of detection of 0.02 µg L-1. In all cases values of repeatability were lower than 5.0% with recoveries of 99.4 ± 1.3%. Precision and accuracy values are adequate for naproxen (Npx) analysis in urine samples.

Supra-alveolar attachment gain in the treatment of combined intra-suprabony periodontal defects by non-incised papillae surgical approach.

AIM: To assess the effectiveness of non-incised papillae surgical approach (NIPSA) in periodontal reconstructive surgery of combined intra-suprabony defects. MATERIALS AND METHODS: Patients with deep periodontal defects treated with NIPSA (n = 20) were analysed. Defects were treated with enamel matrix derivative plus xenograft. Clinical outcomes were assessed before surgery and at 12 months. Wound closure was assessed one week post-surgery. Supra-alveolar attachment gain (SUPRA-AG) was recorded at 12 months post-surgery. RESULTS: Non-incised papillae surgical approach showed significant improvements in clinical attachment gain (5.9 ± 2.38 mm; p < 0.001), recession reduction (0.25 ± 0.44; p < 0.05) and tip of the papillae coronal displacement (0.4 ± 0.5; p < 0.05). It also showed complete wound closure of the apical mucosal incision in the 85% of the cases, with no interproximal tissue necrosis. SUPRA-AG (1.9 ± 1.74) showed a positive tendency, associated with complete intrabony defect resolution. CONCLUSIONS: Non-incised papillae surgical approach promoted primary intention healing, wound stability and space provision for optimal periodontal reconstruction, preserving supra-alveolar soft tissue integrity.

New Poly(Ionic Liquid) Based Fiber for Determination of Oxytetracycline in Milk Samples by Application of SPME-CE Technique.

In this work, a procedure using solid phase microextraction in combination with capillary electrophoresis was developed for the determination of oxytetracycline in milk samples. The method involves the synthesis of poly(1-allyl-3-methyl imidazolium) chloride film on a stainless-steel bar via electropolymerization and its use as an adsorbent for oxytetracycline (OT) by an ionic exchange mechanism. The coated fiber is then immersed in milk samples for retention of oxytetracycline residues, followed by elution, drying, and reconstitution before analysis with capillary electrophoresis. The proposed method achieves a limit of detection of 70 µg L⁻¹ with adequate precision and uncertainty, making this methodology appropriate for the determination of OT in milk samples. The method was applied to the pre-concentration and quantification of oxytetracycline in ten commercial milk samples. Two tested samples were positive for the presence of oxytetracycline but the concentration was below the maximum residue limit according to the international normative standard. The proposed methodology was evaluated according to the Eco-Scale approach, and the total score of 51 indicated that the methodology proposed is both green and acceptable despite the multi-stage character. SPME-CE methodology allows us to perform the sample pre-treatment and determination of OT in an effective and greener way, decreasing the number of steps during the analysis and the generation of waste.

Bone mineral density of the femur in autopsy retrieved total knee arthroplasties.

Bone mineral density (BMD), as measured by DEXA, can vary depending on bone rotation and fat content of soft tissues. We performed DEXA measurements, under controlled positioning, on 24 autopsy-retrieved femora from patients who had fully functional and asymptomatic successful TKA to determine periprosthetic BMD changes and compared results to 24 normal cadaveric femora. In TKA specimens, BMD was affected by gender, preoperative diagnosis, and zone under analysis. The lowest mean BMD was in the anterior femoral condylar zone. Males had higher mean BMD at all zones while patients with preoperative diagnosis of osteoarthritis had higher BMD in the posterior condylar zone. The mean BMD in the anterior femoral condylar zone in TKA specimens was significantly lower than in normal specimens without arthroplasties, most likely due to stress shielding.

A Surgical Approach to Root Coverage and Correction of Mucogingival Conditions and Deformities in Mandibular Incisors with Isolated Gingival Recession: Free Mucogingival Graft. A Pilot Prospective Cohort Study.

The aim of this study was to present a periodontal plastic surgery approach to treat gingival recessions (GRs) and correct mandibular incisor mucogingival conditions and deformities. Isolated deep GRs (≥ 3 mm) in the mandibular incisors (n = 24 teeth) were treated: 66.6% of sites were recession types 2 or 3, and 58.3% of teeth were malpositioned. Recessions were treated using free mucogingival grafts (FMGs) harvested from the buccal aspect of donor teeth with altered passive eruption or healthy periodontal support, with < 3 mm between the cementoenamel junction and the buccal alveolar crest. Clinical parameters (GR, clinical attachment level, interproximal papilla tip location, keratinized tissue, vestibule depth) and root coverage esthetic score were evaluated at 9 months. FMG significantly reduced GR (P < .001) and increased keratinized tissue (P < .001) without loss of vestibule depth (P > .05). Mean root coverage was 94.37% ± 10.60%, mean residual GR was 0.08 ± 0.65 mm, and the mean root coverage esthetic score was 8.9 ± 1.24. Recession types 2/3 showed significant interproximal clinical attachment gain (P < .05). The interproximal papilla was significantly augmented at sites with papilla loss (P < .001). No clinical attachment loss (P = .346) was detected at donor sites. These results suggest that FMG is a promising root coverage approach for recession types 1, 2, and 3, correcting mucogingival conditions and deformities and reconstructing the interproximal papilla.

Adsorbents obtained from recycled polymeric materials for retention of different pollutants: A review.

Polymeric waste is an environmental problem, with an annual world production of approximately 368 million metric tons, and increasing every year. Therefore, different strategies for polymer waste treatment have been developed, and the most common are (1) redesign, (2) reusing and (3) recycling. The latter strategy represents a useful option to generate new materials. This work reviews the emerging trends in the development of adsorbent materials obtained from polymer wastes. Adsorbents are used in filtration systems or in extraction techniques for the removal of contaminants such as heavy metals, dyes, polycyclic aromatic hydrocarbons and other organic compounds from air, biological and water samples. The methods used to obtain different adsorbents are detailed, as well as the interaction mechanisms with the compounds of interest (contaminants). The adsorbents obtained are an alternative to recycle polymeric and they are competitive with other materials applied in the removal and extraction of contaminants.

All-polyethylene tibial implant in young, active patients a concise follow-up, 10 to 18 years.

This is a long-term follow-up report of all-polyethylene tibial components in 60 years and younger, active patients. At the mean follow-up of 12.4 ± 2.7 (range, 10-18 years), no more patients were deceased or lost to follow-up, leaving 32 patients (44 knees) for final analysis. Good to excellent results were achieved in 96% of patients. The mean Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score were 31 and 97, respectively. Sixty-two percent of patients were participating in sport activities such as running, gym exercises, and playing tennis or golf, with a mean UCLA score of 7.2. There were no cases of malalignment, aseptic loosening, excessive wear, or osteolysis. Seven patients (9 knees) had incomplete, nonprogressive demarcation at the zone 1 tibial interface. Kaplan-Meier survivorship at 10 years for revision due to mechanical reasons and for all failures was 97.7% and 95.5%, respectively.

Minimum 5-year wear analysis of first-generation highly cross-linked polyethylene in patients 65 years and younger.

The purpose of this study was to analyze wear rates of highly cross-linked polyethylene comparing the Martell and the Roman methods in 112 total hip arthroplasties in patients 65 years and younger, with a mean follow-up of 5.7 years. The mean wear rates in the Martell and Roman methods were 0.014 ± 0.05 mm/y and 0.011 ± 0.04 mm/y when including all values and 0.043 ± 0.028 mm/y and 0.038 ± 0.02 mm/y when negative values were assumed to be zero, respectively. Both Roman and Martell methods showed similar low wear rates with negative values. The Roman method had higher precision and was more user friendly because it required less steps to measure wear, especially when comparing with the manual feature of Martell method.

Apical approach to the treatment of peri-implantitis in the esthetic zone: nonincised papillae surgical approach (NIPSA). Case reports.

OBJECTIVE: Advanced peri-implantitis treatment is a clinical challenge. Reconstructive surgery is not suggested in defects with limited bony walls and/or in those with a suprabony defect. All studies of peri-implantitis reconstructive surgery have considered a marginal surgical approach. However, in the present case report, a new apical approach is presented for the reconstruction of an advanced peri-implantitis lesion. MATERIALS AND METHOD: First, a non-surgical phase combines prosthetic, mechanical, and chemical strategies. Second, a surgical phase combines the apical nonincised papillae surgical approach (NIPSA) with biomaterials and a connective tissue graft. CONCLUSION: Successful results have been obtained when using a NIPSA for the treatment of peri-implantitis, despite the unfavorable characteristics of the peri-implant defect.

Periodontal granulation tissue preservation in surgical periodontal disease treatment: a pilot prospective cohort study.

PURPOSE: The aim of this study was to evaluate the clinical outcomes of periodontal granulation tissue preservation (PGTP) in access flap periodontal surgery. METHODS: Twenty patients (stage III-IV periodontitis) with 42 deep periodontal pockets that did not resolve after non-surgical treatment were consecutively recruited. Access flap periodontal surgery was modified using PGTP. The clinical periodontal parameters were evaluated at 9 months. The differences in the amount of granulation tissue width (GTw) preserved were evaluated and the influence of smoking was analyzed. RESULTS: GTw >1 mm was observed in 97.6% of interproximal defects, and the granulation tissue extended above the bone peak in 71.4% of defects. At 9 months, probing pocket depth reduction (4.33±1.43 mm) and clinical attachment gain (CAG; 4.10±1.75 mm) were statistically significant (P<0.001). The residual probing depth was 3.2±0.89 mm. When GTw extended above the interproximal bone peak (i.e., the interproximal supra-alveolar granulation tissue thickness [iSUPRA-GT] was greater than 0 mm), a significant CAG was recorded in the supra-alveolar component (1.67±1.32 mm, P<0.001). Interproximal gingival recession (iGR) was significant (P<0.05) only in smokers, with a reduction in the interdental papillary tissue height of 0.93±0.76 mm. In non-smokers, there was no increase in the iGR when the iSUPRA-GT was >0 mm. The clinical results in smokers were significantly worse. CONCLUSIONS: PGTP was used to modify access flap periodontal surgery by preserving affected tissues with the potential for recovery. The results show that preserving periodontal granulation tissue is an effective and conservative procedure in the surgical treatment of periodontal disease.

Polyethylene subluxation: a radiographic sign of locking mechanism failure after modular total knee arthroplasty.

Tibial insert locking mechanisms are intended to limit interface motion and "backside" wear in modular total knee arthroplasty (TKA). Nevertheless, anterior polyethylene subluxation is occasionally apparent on lateral radiographs after TKA, suggesting locking mechanism failure. We retrospectively identified 10 modular posterior-stabilized implants of a single design that were found to have failure of the locking mechanism at the time of revision surgery for osteolysis. Operative reports were reviewed for the presence of backside wear, and preoperative radiographs were inspected for polyethylene subluxation. All 10 implants demonstrated significant backside wear. Nine had anterior polyethylene subluxation evident on preoperative radiographs. Anterior polyethylene subluxation on the lateral radiograph is a subtle sign of failure of the locking mechanism in this modular posterior-stabilized TKA.

Patterns of osseointegration and remodeling in femoral revision with bone loss using modular, tapered, fluted, titanium stems.

Radiographic signs of osseointegration with the use of fluted, tapered, modular, titanium stems in revision hip arthroplasty with bone loss have not been previously categorized. Serial radiographs of 64 consecutive hips with mean follow-up of 6.2 years were retrospectively reviewed. Bone loss was classified as per Paprosky classification, osseointegration was assessed according to a modified system of Engh et al, and Harris Hip Score was used to document pain and function. Seventy-four percent of the hips had type 3 or 4 bone loss. All stems were radiographically osseointegrated. Early minor subsidence was seen in 6.2% of the hips; definite bony regeneration, 73% of the hips; and stress shielding, 26% of the hips. These osseointegration patterns were different from those described for extensively porous-coated cobalt-chromium stems and had a bearing on the evaluation of fixation of these stems.

Preliminary Results of a Minimally Invasive Microsurgical Approach to Sinus Floor Elevation and Bone Reconstruction Using a Palatal Septum Window.

The aim of this case report was to present the preliminary results of a novel microsurgical approach to sinus floor elevation and bone augmentation. This technique was used to treat four patients in whom an implant could not be placed in the maxillary first molar position because of insufficient bone height. The maxillary first molar was extracted, and a sinus access window was created in the palatal area of the bony interradicular septum. The sinus membrane with the palatal septum fragment was elevated, and the sinus space between and above the roots was filled with xenograft. Alveolar preservation was done with xenograft and a nonresorbable membrane. Bone augmentation was evaluated 6 months after preservation by computed tomography and histology; clinical, radiologic, and histologic bone reconstruction were seen, allowing placement of implants. The novel approach utilized in this study demonstrated positive preliminary results in bone reconstruction with reduced morbidity.

Aseptic Tibial Implant Loosening After Total Knee Arthroplasty: Preventable?

Aseptic loosening is a considerable complication that affects the longevity of total knee arthroplasty (TKA) implants. Surgeon technique may help minimize aseptic loosening after TKA. Meticulous cementation of the prosthesis and the bone surface during various stages of cement polymerization will maximize cement adherence to the prosthesis and the bone, respectively. Pressurization of the cement in the canal and at the cut surface to achieve at least 2 mm of cement depth penetration has been reported to increase TKA implant longevity.

Laterally rotated flap for soft tissue augmentation around maxillary loaded osseointegrated dental implants: preliminary results of a pilot study.

A minimal width and thickness of keratinized and attached soft tissue is desirable to prevent peri-implant diseases. This report describes the preliminary results of a pilot study of a surgical approach for soft tissue augmentation around loaded dental implants in the partially or totally edentulous maxilla. Four patients presenting eight maxillary implants with a buccal peri-implant soft tissue deficiency received a laterally rotated flap. A buccal mesial and apical recipient area was created around each implant, and a pediculated keratinized graft was rotated 90° from the distopalatal and positioned and sutured on the peri-implant buccal aspect. All implants treated showed a gain in buccal clinical peri-implant attachment (1.37 ± 0.44 mm) and buccal soft tissue levels (2.06 ± 1.40 mm) and interproximal soft tissue levels (1 ± 0.75 mm). The technique provided quality soft tissue with a gain in soft tissue thickness (3.06 ± 0.68 mm) and keratinized wide tissue (4.69 ± 0.80 mm) with minimal morbidity (1575 ± 549.67 mg of ibuprofen) and maintenance of prosthetic loading. Peri-implant soft tissue stability was maintained for 13.5 ± 1.87 months. Laterally rotated flap can be applied and provide clinical benefits to compromised implants due to the presence of buccal peri-implant soft tissue deficiency. Further studies are required to confirm these preliminary results.

Papilla preservation periodontal surgery in periodontal reconstruction for deep combined intra-suprabony defects. Retrospective analysis of a registry-based cohort.

BACKGROUND: Suprabony defects are the most prevalent defects and there is very little evidence on their treatment. This study aims to assess the effectiveness of papilla preservation periodontal surgery in the periodontal reconstruction of combined deep intra-suprabony defects. MATERIAL AND METHODS: 20 patients with combined intrabony and supra-alveolar deep periodontal defects treated by papilla preservation periodontal surgery were analyzed. Defects were treated with enamel matrix derivate plus xenograft. Clinical recordings made before surgery and at 12 months. RESULTS: Papilla preservation periodontal surgery showed significant PPD reduction (4.4 ± 1.46 mm; p<0.001), clinical attachment gain (3.35 ± 1.6 mm; p<0.001), increased REC (1.05 ± 0.94; p<0.001), papilla apical displacement (0.85 ± 1.31 mm; p<0.005) and KT reduction (0.5 ± 0.76 mm; p<0.05). At one week, there was incomplete wound closure and necrosis in 40% and 30% of the treated sites, respectively. At one year, the intrabony component filling was 73.65 ± 27.6 % and the supra-alveolar attachment gain indicated an incomplete intrabony defect resolution (-0.15 ± 1.56 mm). CONCLUSIONS: Periodontal pocket was significantly reduced and the level of clinical attachment increased. However, there was significant recession of the gingival margin and the papilla and a trend to incomplete resolution of the intrabony component. Key words:Periodontitis, surgical flaps, reconstructive surgery, regeneration.

Two-year to five-year follow-up of femoral defects in femoral revision treated with the link MP modular stem.

Femoral deficiency has been shown to adversely affect the results of revision total hip arthroplasty. Tapered titanium modular stems allow distal fixation of the fluted, conical portion of the implant in the setting of proximal bone loss. One hundred two consecutive hips with proximal bone loss underwent revision femoral reconstruction between 1998 and 2002 at 3 centers using the Link MP modular stem. Forty-three hips had Mallory type 3C femoral deficiency. Ninety-seven hips were observed for an average of 45 months (range, 24-72; median, 36 months). Clinically, mean Harris hip score improved from 36 to 84 (range, 54-99). Radiographically, 93 hips were considered stable, with no circumferential lucencies at the distal fixation surface. Three hips migrated and required revision, along with one periprosthetic fracture. Five other hips had nonprogressive migration of 1 to 2 mm.