High failure rate of 2-stage revision for the infected total elbow arthroplasty: a single institution's experience.

BACKGROUND: Despite 2-stage revision being a common treatment for elbow prosthetic joint infection (PJI), failure rates are high. The purpose of this study was to report on a single institution's experience with 2-stage revisions for elbow PJI and determine risk factors for failed eradication of infection. The secondary purpose was to determine risk factors for needing allograft bone at the second stage of revision in the setting of compromised bone stock. METHODS: We retrospectively analyzed all 2-stage revision total elbow arthroplasties (TEAs) performed for infection at a single institution between 2006 and 2020. Data collected included demographics and treatment course prior to, during, and after 2-stage revision. Radiographs obtained after explantation and operative reports were reviewed to evaluate for partial component retention and incomplete cement removal. The primary outcome was failed eradication of infection, defined as the need for repeat surgery to treat infection after the second-stage revision. The secondary outcome was the use of allograft for compromised bone stock during the second-stage revision. Risk factors for both outcomes were determined. RESULTS: Nineteen patients were included. Seven patients (37%) had either the humeral or ulnar component retained during the first stage, and 10 (53%) had incomplete removal of cement in either the humerus or ulna. Nine patients (47%) had allograft strut used during reimplantation and reconstruction. Nine patients (47%) failed to eradicate the infection after 2-stage revision. Demographic data were similar between the repeat-infection and nonrepeat-infection groups. Six patients (60%) with retained cement failed compared with 3 patients (33%) with full cement removal (P = .370). Two patients (29%) with a retained component failed compared to 7 patients (58%) with full component removal (P = .350). Allograft was used less frequently when a well-fixed component or cement was retained, with no patients with a retained component needing allograft compared to 9 with complete component removal (P = .003). Three patients (30%) with retained cement needed allograft, compared with 6 patients (67%) who had complete cement removal (P = .179). CONCLUSION: Nearly half of the patients failed to eradicate infection after 2-stage revision. The data did not demonstrate a clear association between retained cement or implants and risk of recurrent infection. Allograft was used less frequently when a component and cement were retained, possibly serving as a proxy for decreased bone loss during the first stage of revision. Therefore, the unclear benefit of removing well-fixed components and cement need to be carefully considered as it likely leads to compromised bone stock that complicates the second stage of revision.

Contemporary concepts on periodontal complications from prosthetic and restorative therapies.

The clinical outcome of every prosthetic and restorative procedure depends on the maintenance of a healthy periodontium. It is, therefore, important that the prosthodontist and restorative dentist cause no harm or permanent damage to the underlying hard and soft tissues when performing clinical procedures necessary to carry out the planned treatment. Several factors involved in these procedures have been described to have an impact on gingival health. For the present article, a selection of four of these factors are presented with the goal of evaluating the current trends and their influence on periodontal structures: (1) tooth preparation configuration and apical extension, (2) gingival tissue sulcular expansion/retraction, (3) prosthetic contours, and (4) prosthesis marginal adaptation and the consequences of excess cement remnants. Based on the available scientific evidence and clinical experience, recommendations for the practitioner are given.

Evaluation of Effectiveness of Cement Removal From Implant-Retained Crowns Using a Proposed "Circular Crisscross" Flossing Technique.

Extruded cement during dental implant crown cementation may cause peri-implant diseases if not removed adequately. The purpose of this study was to evaluate the efficiency of removal of cement after cementation of implant crowns using an experimental circular crisscross flossing technique (CCFT) flossing technique, compared to the conventional "C"-shape flossing technique (CSFT). Twenty-four patients rendered 29 experimental and 29 control crowns. Prefabricated abutments were secured to the implant such that the margins were at least 1 mm subgingivally. The abutments were scanned using computer-aided design/computer-aided manufacturing technology and Emax crowns were fabricated in duplicates. Each crown was cemented individually and excess cement was removed using the CSFT and the CCFT techniques. After completion of cementation was completed, the screw access holes were accessed and the crown was unscrewed along with the abutment. The samples were disinfected using 70% ethanol for 10 minutes. Crowns were divided into 4 parts using a marker to facilitate measurement data collection. Vertical and horizontal measurements were made for extruded cement for each control and experimental groups by means of a digital microscope. One-hundred and seventeen measurements were made for each group. Mann-Whitney test was applied to verify statistical significance between the groups. The CCFT showed a highly statistically significant result (104.8 ± 13.66, P < .0001) for cement removal compared with the CSFT (291.8 ± 21.96, P < .0001). The vertical measurements of the extruded cement showed a median of 231.1 µm (IQR = 112.79-398.39) and 43.62 µm (IQR = 0-180.21) for the control and the experimental flossing techniques, respectively. The horizontal measurements of the extruded cement showed a median of 987.1 µm (IQR = 476.7-1,933.58) and 139.2 µm (IQR = 0-858.28) for the control and the experimental flossing techniques, respectively. The CCFT showed highly statistically significant less cement after implant crowns cementation when compared with the CSFT.

A Novel Universal Cementation Technique for Implant-Supported Crowns with Subgingival Margins.

Restoration of implant crowns with subgingival margins has always been a challenge. If done precisely it leads to better treatment outcomes and prognosis. An incorrect technique and improper execution of the luting procedure are known to cause a high incidence of peri-implant disease due to incomplete elimination of the luting agent. Deep subgingival abutment margins are difficult to recognize, and cement removal in these cases becomes complicated if the sulcus depth is greater than 3 mm. Irrespective of the type of instrument used to remove the excess cement, scratches on the abutment and some cement remnants are consistently noticed. Therefore elimination of excess luting agent before the prosthesis is inserted intraorally is considered an effective technique to prevent complications due to excess luting agent. This article presents a chairside universal technique for cementation of implant crowns on abutments with deep subgingival margins. This technique attempts to minimize the amount of excess cement in peri-implant tissue.

The anterior femoral cortical window as an alternative to an extended trochanteric osteotomy in revision hip arthroplasty surgery: the evolution of the surgical technique and outcomes in 22 consecutive cases.

BACKGROUND: The anterior femoral cortical window is an attractive alternative to the extended trochanteric osteotomy when removing femoral cement in revision hip arthroplasty. CT-based additive manufacturing technology has now permitted the creation of patient-specific instrumented (PSI) jigs to facilitate this. The jig simplifies creation of the window, potentiating medullary exposure through an optimally-sized window and therefore cement removal. Between 2006 and 2021 this technique was used in 22 cases at a regional hospital in New Zealand (mean age 74; range 44 to 89 years). 16 cases were for aseptic loosening and 6 for infection. We describe the technique and our case series. Bone incorporation for the cortical window was assessed in all cases using CT imaging. Oxford scores were obtained at a minimum of 6 months after revision surgery. Of the 6 septic cases 5 went onto successful stage-2 procedures, the other to a Girdlestone procedure. RESULTS: The mean rectangular shaped window size was 8 × 1.5 cm and in each case, this provided adequate intramedullary access. On average at minimum 5 months post-surgery, 84% bone incorporation of the cortical window occurred on CT (40-100%). The functional outcome Oxford hip score was 37 (range 22-48) for 10 cases. There were 2 cases with femoral component subsidence which then stabilised. CONCLUSIONS: This technique description and retrospective case series has shown the effectiveness of removing a distal femoral cement mantle in revision hip arthroplasty using an anterior femoral cortical window, recently optimised using a PSI jig. This technique is a straightforward alternative to a trochanteric osteotomy. Reliable bony integration of the cortical window occurred and functional outcomes were comparable with the mean score for revision hip procedures reported in the New Zealand Joint Registry.

Ultrasonic bone cement removal efficiency in total joint arthroplasty revision: A computer tomographic-based cadaver study.

Polymethylmethacrylate (PMMA) removal during septic total joint arthroplasty revision is associated with a high fracture and perforation risk. Ultrasonic cement removal is considered a bone-preserving technique. Currently, there is still a lack of sound data on efficacy as it is difficult to detect smaller residues with reasonable technical effort. However, incomplete removal is associated with the risk of biofilm coverage of the residue. Therefore, the study aimed to investigate the efficiency of ultrasonic-based PMMA removal in a human cadaver model. The femoral components of a total hip and a total knee prosthesis were implanted in two cadaver femoral canals by 3rd generation cement fixation technique. Implants were then removed. Cement mantle extraction was performed with the OSCAR-3-System ultrasonic system (Orthofix®). Quantitative analysis of cement residues was carried out with dual-energy and microcomputer tomography. With a 20 µm resolution, in vitro microcomputer tomography visualized tiniest PMMA residues. For clinical use, dual-energy computer tomography tissue decomposition with 0.75 mm resolution is suitable. With ultrasound, more than 99% of PMMA was removed. Seven hundred thirty-four residues with a mean volume of 0.40 ± 4.95 mm3 were identified with only 4 exceeding 1 cm in length in at least one axis. Ultrasonic cement removal of PMMA was almost complete and can therefore be considered a highly effective technique. For the first time, PMMA residues in the sub-millimetre range were detected by computer tomography. Clinical implications of the small remaining PMMA fraction on the eradication rate of periprosthetic joint infection warrants further investigations.

The effect of different methods of cleansing temporary cement (with and without eugenol) on the final bond strength of implant-supported zirconia copings after final cementation: An in vitro study.

Background: The temporary cement remaining inside the dental prosthesis can act as a source of microbial colonization and contamination and decrease the final cement retention. Consequently, complete removal of temporary cement before permanent cementation is suggested. This study aimed to assess the effect of different cleaning methods for removing temporary cement on the tensile bond force (TBF) of permanently cemented implant-supported zirconia copings. Materials and Methods: In this in vitro study fifty titanium abutments were screwed onto 50 analogs with 30 Ncm torque into in acrylic resin blocks. Each abutment was scanned separately, and 50 zirconia copings were designed and milled. Permanent resin cement was used to cement copings of control group (N = 10). Copings were divided into two temporary cementation types that in each group, two cleansing methods were used: Temp-S (temporary cement with eugenol and sandblasted after debonding), Samples of the control group were placed in the universal testing machine, and the TBF values were recorded. Samples of the test groups after debonding and cleaning the abutments were subjected to cement with permanent resin cement, aging, and removing. Levene test, two-way analysis of variance (ANOVA), and Tamhane post hoc tests were applied. α = 0.05. Results: The highest and lowest TBF values were found for the TempNE-SU (554.7 ± 31.5 N) and Temp-S (492.2 ± 48 N) groups, respectively. The two groups of isopropyl alcohol baths in ultrasonics in combination with sandblasting showed statistically higher TBF values than the other two groups that used only sandblasting (P < 0.001) and had similar values compared to the control group. Conclusion: Sandblasting combined with immersion in an ultrasonic bath containing isopropyl alcohol resulted in statistically similar values to the values of cementation with resin cement from the beginning. However, cleaning the inside of the copings only by sandblasting method reduced the values of the final retention force in comparison to cement with permanent resin cement from the beginning.

Surgical Technique of a Cement-On-Cement Removal System for Hip and Knee Arthroplasty Revision Surgery.

Cement removal during hip or knee arthroplasty revision surgery is technically demanding and prone to severe complications such as periprosthetic fractures, incomplete cement removal, or perforations. Several alternative techniques have been developed to enable complete, accurate, and safe removal of cement from bone, including osteotomies and cortical windows, endoscopic instruments, ultrasound devices, lithotripsy, and laser-assisted removal. We describe a cement-on-cement technique with a sterile, single-use tool for cement removal. The cement is removed piece by piece using a specifically designed device, without osteotomies or cortical windows.

Ultrasonic cement removal in cement-in-cement revision total hip arthroplasty: What is the effect on the final cement-in-cement bond?

OBJECTIVES: Previous studies have evidenced cement-in-cement techniques as reliable in revision arthroplasty. Commonly, the original cement mantle is reshaped, aiding accurate placement of the new stem. Ultrasonic devices selectively remove cement, preserve host bone, and have lower cortical perforation rates than other techniques. As far as the authors are aware, the impact of ultrasonic devices on final cement-in-cement bonds has not been investigated. This study assessed the impact of cement removal using the Orthosonics System for Cemented Arthroplasty Revision (OSCAR; Orthosonics) on final cement-in-cement bonds. METHODS: A total of 24 specimens were manufactured by pouring cement (Simplex P Bone Cement; Stryker) into stainless steel moulds, with a central rod polished to Stryker Exeter V40 specifications. After cement curing, the rods were removed and eight specimens were allocated to each of three internal surface preparation groups: 1) burr; 2) OSCAR; and 3) no treatment. Internal holes were recemented, and each specimen was cut into 5 mm discs. Shear testing of discs was completed by a technician blinded to the original grouping, recording ultimate shear strengths. Scanning electron microscopy (SEM) was completed, inspecting surfaces of shear-tested specimens. RESULTS: The mean shear strength for OSCAR-prepared specimens (33.6 MPa) was significantly lower than for the control (46.3 MPa) and burr (45.8 MPa) groups (p < 0.001; one-way analysis of variance (ANOVA) with Tukey's post hoc analysis). There was no significant difference in shear strengths between control and burr groups (p = 0.57). Scanning electron microscopy of OSCAR specimens revealed evidence of porosity undiscovered in previous studies. CONCLUSION: Results show that the cement removal technique impacts on final cement-in-cement bonds. This in vitro study demonstrates significantly weaker bonds when using OSCAR prior to recementation into an old cement mantle compared with cement prepared with a burr or no treatment. This infers that care must be taken in surgical decision-making regarding cement removal techniques used during cement-in-cement revision arthroplasty, suggesting that the risks and benefits of ultrasonic cement removal need consideration.Cite this article: A. Liddle, M. Webb, N. Clement, S. Green, J. Liddle, M. German, J. Holland. Ultrasonic cement removal in cement-in-cement revision total hip arthroplasty: What is the effect on the final cement-in-cement bond? Bone Joint Res 2019;8:246-252. DOI: 10.1302/2046-3758.86.BJR-2018-0313.R1.

Use of flexible elbow reamers for cement removal in the humerus during revision shoulder arthroplasty.

Humeral cement removal in revision shoulder arthroplasty can be challenging. Secondary damage to the bone and neighbouring structures can be extensive and compromise later reconstruction. We present a technique that employs flexible reamers from elbow arthroplasty instrumentation, which aids cement removal at the same time as minimizing the risk of iatrogenic injury.