Spacer Implantation Research Articles

Screw-Tip Augmented Locked Plating Versus Primary Reverse Total Shoulder Arthroplasty in Displaced Proximal Humeral Fractures: A Retrospective Comparative Cohort Study With a Mean Follow-Up of 39 Months.

IntroductionThis study compared the clinical and radiologic outcomes of screw-tip augmented locking plate osteosynthesis (STA) vs primary reverse total shoulder arthroplasty (RSA) in elderly patients with displaced proximal humeral fractures.Methods60 patients (age >65 years) with a displaced proximal humeral fracture underwent open reduction and internal fixation with locking plate and fluoroscopy controlled screw-tip augmentation. Sixty matched individuals (age, gender, fracture pattern, and mean follow-up) treated by RSA for fractures were identified from the institutional database and outcomes as well as occurring complications and need for revision surgery were compared.ResultsAt 39 months’ follow-up, 25 patients in the STA group (mean age 74.5 ± 12 years, 76.7% woman) showed a mean Constant Score (CS) of 68 ± 18.8 points. Mean %CS compared to the contralateral side was 81.6 ± 19.8%. Of 60 matched individuals in the RSA group, 22 patients (mean age 78.9 ± 8.2 years, 76.7% woman) showed a mean CS of 60.6 ± 21.2 points (P = .33), and the mean %CS compared to the contralateral side was 81.6 (74.7 ± 18.6)% (P = .14). The overall complication rate in STA group was 32% (secondary varus or valgus displacement >10°, n = 4, avascular necrosis, n = 4). In RSA group, the overall complication rate was 4.5% (P = <.05). We observed one early onset infection. Revision surgery with removal of the prosthesis and PMMA spacer implantation for two-stage revision was necessary. The follow-up rate was 41.7 vs 36.7%.ConclusionsScrew-tip augmented locked plating and reverse total shoulder arthroplasty result in comparable satisfying functional outcome 3 years following a displaced proximal humeral fracture in elderly patients. However, we noted a higher complication and revision rate in the STA group. In contrast, primary reversed shoulder arthroplasty resulted in a lower rate of complications and revisions, which may be beneficial in elderly patients.

330. Risk Factors for Acute Kidney Injury after the Use of Antibiotic Loaded Bone Cement in Orthopedic Surgery – a Retrospective Case-control Study

BackgroundAs the number of joint replacement surgeries continues to rise, so does the number of joint infections. Many patients end up needing the implantation of antibiotic loaded bone cement (ALBC) to treat their infection. The use of localized high dose vancomycin, tobramycin, and gentamicin may be linked to acute kidney injury (AKI) in certain patients. Our hypothesis is that patients who developed AKI after receiving a joint spacer had a predisposition to AKI due to other comorbidities, high antibiotic doses in ALBC, immunosuppression, or the use of other nephrotoxic drugs pre-op. These patients may need close monitoring of their renal function and serum antibiotic levels after surgery.MethodsWe performed a chart review of 428 patients who underwent an orthopedic surgery that involved insertion of ALBC at our institution between 2015 and 2018. We excluded patients under age 18, those who had antibiotic irrigation only, trauma patients, non-arthroplasty surgeries (such as fractures and debridement of deep wounds), and patients with missing data for 30 days after the surgery. We identified 57 patients who fit our inclusion criteria and received a bone cement spacer or beads to treat an infection of the hip, knee, shoulder, or ankle. We matched patients who had AKI to 2 patients who did not have AKI. Matching was based on age (± 5 years), joint operated on, and antibiotics used.Results15 patients showed an elevated serum creatinine level of over 1.2 within 30 days of surgery. 86.7% of these patients were male, their average age was 64.1 ± 6.2 years old, 40% had hip surgery, 46.7% knee surgery, 6.7% ankle, and 6.7% shoulder. All received vancomycin and tobramycin in Palacos bone cement. Compared to their case-control matches, these patients had more frequent use of immunosuppressive medication, a history of malignancy, a history of previous kidney disease, and obesity. The use of combined intravenous vancomycin and piperacillin-tazobactam post-operatively may also be linked to higher rates of AKI.ConclusionImmunosuppression, obesity, male gender, and history of kidney injury and cancer are factors associated with AKI after ALBC spacer implantation. Further analysis and study are needed to identify potential causation between ALBC use and AKI.Disclosures All Authors: No reported disclosures

A New Proximal Dorsal Approach for DIP Arthroplasty.

Degenerative changes of the distal interphalangeal (DIP) joints can be painful, disabling, and disfiguring. Swanson spacers can be used for DIP arthroplasty. The standard approach for Swanson spacer implantation at the DIP joint involves transecting the extensor tendon close to its insertion, which necessitates a 6-week period of postoperative immobilization. Another DIP approach involves sparing the extensor tendons, as already published. Both techniques lead to a similar range of motion of the replaced DIP joints. We present a novel approach for DIP joint arthroplasty with division of the extensor tendon in zone 2 with only 2 weeks of postoperative immobilization. Optimizing the motion-preserving operative approaches is of value to our high-demand patients. Postoperative results do not differ from the postoperative range of motion published in the literature for both tendon-sparing and standard approaches. But our approach is technically easy and requires a significantly shorter time of immobilization.

Two-staged revision of the infected total elbow arthroplasty with an articulating spacer: a good option for an unsolved problem

Background/PurposeInfection after total elbow arthroplasty (TEA) is a difficult problem for both patients and surgeons. When two-stage revision is required, a custom antibiotic laden articulating spacer fashioned using Ilizarov external fixation rods allows for a functional elbow prior to revision. The purpose of this review and case series is to investigate clinical and patient reported outcomes of the articulating spacer and investigate its effectiveness as bridge prosthesis and a long-term option prior to revision. MethodsA retrospective review between 2016 and 20 identified patients with an infected TEA treated with an articulating spacer. Patient age, surgical indication, spacer duration, and comorbidities were recorded. Outcome scores included Visual Analog Scale (VAS) for pain (1-10), Single Assessment Numerical Evaluation (SANE) (0-100%) of overall elbow function, and range of motion at the pre-spacer, three month, and most recent follow-up visit. Statistical analysis compared outcomes at each time period using an analysis of variance or Friedman's test followed by post-hoc analyses using paired t-tests or Sign tests. Minimal Detectable Change (MDC) was calculated for pain and SANE scores. ResultsEleven articulating spacers (9 patients) with 13 months mean spacer implantation were identified. Mean long-term spacer implantation (4 patients, 6 spacers) was 22 months (range 7-40). Median pain scores were significantly lower at three month and latest follow-up relative to preoperative assessment. Analysis of long term spacers revealed a significant decrease in pain scores from pre-op to 3 months. Analysis of SANE scores demonstrated three month and latest follow-up scores to be significantly improved from preoperative assessment. SANE scores for long-term spacers were significantly improved at three months and last follow-up. Range of motion analysis demonstrated no significant differences other than significantly increased pronation/supination at three months in long term spacers. Eight of 11 spacers met MDC for pain and 5/11 for SANE at three months. Three of 6 long-term spacers met MDC for SANE. Total implant cost is $158.32. ConclusionMost spacers are effective in clearing infection, but a custom articulating spacer importantly provides significant, early pain relief and improved patient reported function of the elbow. Improvements in range of motion are also achieved. An articulating spacer allows for an improved quality of life during the interim period prior to revision as well as a long-term option providing sustained improvement in function for those unwilling to undergo further surgery or with complex medical issues that preclude them from a definitive revision. Level of EvidenceLevel IV; Case Series

Improvement in Neurogenic Pain with Epidural Injections Following Interspinous Spacer Implantation in Patients with Lumbar Stenosis: A Case Series

Background: Lumbar spinal stenosis with neurogenic claudication can be a debilitating condition, affecting quality of life. Interspinous spacer implantation is a minimally invasive procedure for treatment of lumbar spinal stenosis with neurogenic claudication and associated symptoms by minimizing spinal extension and therefore neural compression. Case Presentation: This case series presents 4 cases of patients with multilevel stenosis, most radiographically severe in the lumbar region, all who received interspinous spacers at L3-4 and L4-5 after minimal improvement in symptoms with conservative management including epidural injections. In all 4 cases, patients reported improved standing and gait but limited improvement in pain and overall function after interspinous spacer implantation. Each patient underwent repeat epidural injections at or below the level of the interspinous spacer with significant improvement in pain for up to 6 months. Conclusion: Our conclusion is that either postspacer epidural injections helped reduce inflammation associated with the implantation procedure, or the spacer maintained an open space to allow the injectate to permeate areas with the most stenosis and help reduce inflammation and therefore pain. Key words: Epidural injection, interspinous process decompression, interspinous spacer, interspinous spacer implant, low back pain, lumbar spinal stenosis, neurogenic claudication, spinal stenosis

Virtual Spacer Implantation Platform Based on Finite Element Method for Simulation and Planning Patient-Specific Spacer Placement

In recent years, due to major advances in radiotherapy (RT) delivery systems, more attention is paid to integrating RT into cancer management. Efficacy of advanced RT techniques like stereotactic body radiation therapy is shown for lung, liver, prostate and pancreas cancer. Use of RT, however, can be limited due to proximity of organs at risk (OARs). Previous studies show dosimetric benefits of spacers, namely dose escalation and increasing OAR sparing, to make separation between target and OARs for prostate and recent studies for pancreas. Yet, dosimetric benefits of placement of spacer highly depend on location and shape of spacer implanted. Accordingly, purpose of our study is to reduce geometric uncertainties of spacer placement by presenting a simulation platform that generates an optimized plan for spacer implantation. Pre- and post-spacer paired computed tomography (CT) are acquired. Gross target volume (GTV) and OARs are delineated by physician, as well as, spacer in the post-injection CT. Data is anonymized and fed into our simulation platform to create finite element model (FEM) of spacer placement process and simulate using finite element analysis (FEA). In this study, location of spacer is determined by post-injection CT for validation. To do so, pre- and post-injection CTs are registered by a rigid registration method while bones and later head of pancreas and prostate are used as landmark. To ensure the accuracy and convergence of FEA, anatomical and physical properties of organs are considered as a set of patient-specific boundary conditions. Finally, result of FEA is interpreted as deformations of 3D CT images and structures. To evaluate performance of simulation, we utilized overlap volume histogram (OVH) thresholds, L3cc and L9cc defined as overlapping tumor and OAR volume at 3mm and 9mm expansion of GTV, while introducing Distance Angular Histogram (DAH) to assess spatial performance of our method. 4 cases of hydrogel spacer are included in this study: 2 prostate and 2 pancreas cases. Applicable to any type of spacer, we used hydrogel cases for validation due to considerably higher level of biomechanical complexity. OVH thresholds (L3cc and L9cc) are similar for virtual and post injection cases, and considerably lower compared to pre-injection (table_1). Further, DAH shows that distribution of distance between tumor and OAR is more than a simple shift, and thus, closer to reality. Although spacer can improve RT outcome, its use is impeded by uncertainties associated with placement procedure. Our virtual spacer platform is aimed to help planning placement of spacer and obviate uncertainties of using it. Future studies will focus on improving performance and integration to real-time ultrasound guided procedure.Tabled 1Abstract 2678; TableOVH MetricL3mmL9mmSitesPancreasProstatePancreasProstateCasesABCDABCDPre-Injection0.0050.015000.0700.1600.0200.126Post-Injection00000.0140.0140.0050.004Virtual Spacer00000.0190.0120.0010.005 Open table in a new tab

The subacromial spacer system for irreparable posterosuperior rotator cuff tears: A retrospective study of 47 patients with a two-year follow-up.

Numerous surgical options are available for the management of massive irreparable rotator cuff tears, but there are no current definitive guidelines concerning the optimal treatment modality. The purpose of this study was to evaluate the efficacy and safety of a biodegradable subacromial spacer (InSpace) implantation in patients with irreparable rotator cuff tears. A retrospective study was conducted involving 47 patients treated with the InSpace balloon between 2016 and 2018. Shoulder function was assessed using Constant Score. Pain was scored using a visual analogue scale, with scores ranging from 0 to 10. At an average follow-up of 24.6 months (range 12-38), the Constant Score had improved from 39.4 to 71.5 points (p < 0.0001). The range of motion, a main component of Constant Score, was improved after two years, from 27.6 to 42.2 points (p < .001). The visual analogue scale score decreased from 6.32 at baseline to a mean score of 2.7 points (p < 0.0001). Arthroscopic deployment of the InSpace device was found to be a safe, reliable treatment option in patients with painful irreparable rotator cuff tears, with meaningful improvement in shoulder function without serious complications.

Two-stage revision arthroplasty in the treatment of periprosthetic hip infections with severe bone loss: Results from 182 cases.

The optimum treatment for periprosthetic joint infection (PJI) of the hip with substantial bone defects remains controversial. A retrospective assessment was performed for 182 patients treated for PJI with a two-stage protocol from 2005 to 2015. Implant removal and debridement were followed by Girdlestone arthroplasty or spacer implantation. The results of the Girdlestone and spacer groups were compared. There were 71 cases that received spacers, and 111 Girdlestone procedures were performed. After the first stage, 26.37% of cultures were negative, and among patients with a detected pathogen, methicillin-sensitive Staphylococcus aureus was the most common organism (41.79%). Acetabular and femoral bone defects, according to the Paprosky classification, were more severe in the Girdlestone group (P<0.05). During the follow-up (mean, 5.95 years), the overall incidence of complications was 21.42%. The mean Harris hip score was significantly lower in the Girdlestone group (68.39 vs 77.79; P<0.0001). The infection recurrence rate reached 8.79%. Despite satisfactory infection control, the number of complications and poor functional outcomes associated with resection arthroplasty indicate the necessity for development of different approaches for patients with advanced bone loss.

A two-stage approach to primary TKA using articulating antibiotic-loaded spacers improve function and eradicate infection in septic arthritic knees.

The treatment of an infected arthritic knee might be challenging. The failure rate has been reported to be high for open or arthroscopic debridement. A subsequently high rate of infection has been noted in these patients undergoing primary total knee arthroplasty (TKA). In the present study, a two-stage approach using an articulating spacer was used. The hypothesis was that the procedure would eradicate the infection and improve pain and function in these patients. A total of 16 consecutive patients were enrolled in this retrospective study. The mean follow-up time was 6.1years (range 2.0-9.9years). Patients with advanced osteoarthritis and infection of the knee were included. All patients had previously undergone one or more failed arthroscopic or open procedures for the eradication of infection. All patients received the same homemade metal-on-plastic articulating antibiotic spacer. Double antibiotic therapy was given for 2weeks intravenously and orally for 4weeks. TKA implantation was performed 6weeks after the first stage. The infection was eradicated without recurrence in all patients. The functional results were significantly improved, and pain was significantly reduced after spacer and TKA implantation. The mean amount of knee flexion was 95 ± 30° preoperatively, and it increased to 109 ± 14° (p = 0.012) after spacer implantation and to 119 ± 10° (p = 0.002) after TKA implantation. The mean KSS objective was 58 ± 12 preoperatively, and it increased to 75 ± 14 (p < 0.0001) after spacer implantation and to 96 ± 3 (p < 0.0001) after TKA implantation. The mean KSS function was 17 ± 11 preoperatively, and it increased to 46 ± 10 (p < 0.0001) after spacer implantation and to 86 ± 6 (p < 0.0001) after TKA implantation. The mean VAS score was 65 ± 11 preoperatively, and it decreased to 2 ± 4 (p < 0.0001) after spacer implantation and to 1 ± 2 (p < 0.0001) after TKA implantation. The two-stage procedure for the treatment of infected arthritic knees after failed eradication surgery was effective in all patients. Using an antibiotic articulating metal-on-plastic cement spacer showed improved functional results between the stages and at the final follow-up. No intra- or postoperative complications occurred.

Arthrodesis with Retrograde Intramedullary Nail for Recurrent Infected Total Knee Arthroplasty with Patellar Tendon Rupture: A Case Report and Literature Review

Patellar tendon rupture after total knee arthroplasty is a rare, but often catastrophic complication. In addition, infection is also a dreaded complication after total knee arthroplasty. We report an 84-year-old female that has late infected total knee arthroplasty with patellar tendon rupture treated with resection arthroplasty and then subsequent arthrodesis with retrograde intramedullary nail.Case Presentation:The 84-year-old female underwent left total knee arthroplasty 2 years ago and revision arthroplasty last year after trauma. She presented to the emergency department with painful disability of left knee. The septic arthritis of left knee was confirmed by bacterial culture through arthrocentesis which yielded methicillinsensitive staphylococcus aureus. Patellar tendon rupture was also noted by loss of extension mechanism and patella alta in plain films. Despite attempts on open debridement and parenteral antibiotics, the infection did not settle. Resection arthroplasty with vancomycin- impregnated cement spacer implantation was performed following by 4-week parenteral antibiotics therapy. The ESR and CRP level of serum improved gradually. Arthrodesis of left knee with retrograde locking intramedullary femoral nail through single incision of the knee was performed. Protected weight bearing was allowed in one week after arthrodesis. The patient discharged 2 weeks later without recurrent infection, but leg length discrepancy about 2cm was noted.Discussion:Patellar tendon rupture after total knee arthroplasty is a rare but disabling complication whose management is often difficult. It was reported that incidence of patellar tendon rupture in literature varies between 0.3- 12.4% for primary total knee arthroplasty and between 1-15% for revision total knee arthroplasty. Contributing factors are excessive dissection and knee manipulation, and trauma. In the literature, various different operative techniques and rehabilitation programs have been described indicating the lack of a golden standard treatment protocol. However, in patients with a total knee arthroplasty, the results have been discouraging. Reconstruction of the patellar tendon can be utilized semitendinosus-gracilis graft with an interference screw and a staple fixation in treating acute ruptures, whereas allografts and synthetic mesh are indicated for chronic cases. Nevertheless, treatment outcomes for ruptured patellar tendon are not good. Gold standard treatment of infected total knee arthroplasty was resection arthroplasty with antibiotic-impregnated bone cement spacer and parenteral antibiotics therapy and then second stage revision total knee arthroplasty until the infection is eradicated. The patella tendon repair and second revision arthroplasty were not suggested by Jake et al. Patellar tendon rupture is best treated with primary repair, but infected prosthetic knee with patellar tendon rupture seemed to be more difficult to manage. Arthrodesis but not revision arthroplasty may be the best choice after infection control to improve the patient’s level of function.

CBCT evaluation of inter- and intra-fraction motions during prostate stereotactic body radiotherapy: a technical note

BackgroundIn most clinical trials, gold fiducial markers are implanted in the prostate to tune the table position before each radiation beam. Yet, it is unclear if a cone-beam computed tomography (CBCT) should be performed before each beam to monitor a possible variation of the organs at risk (OARs) fullness, especially in case of recto-prostatic spacer implantation. The present study aimed at assessing the inter- and intra-fraction movements of prostate, bladder and rectum in patients implanted with a hyaluronic acid spacer and undergoing prostate stereotactic body radiotherapy (SBRT).MethodsData about consecutive patients undergoing prostate SBRT were prospectively collected between 2015 and 2019. Inter-and intra-fraction prostate displacements and volume variation of organs at risk (OARs) were assessed with CBCTs.ResultsEight patients were included. They underwent prostate SBRT (37.5Gy, 5 fractions of 7.5Gy) guided by prostate gold fiducial markers. Inter-fraction variation of the bladder volume was insignificant. Intra-fraction mean increase of the bladder volume was modest (29 cc) but significant (p < 0.001). Both inter- and intra-fraction variations of the rectum volume were insignificant but for one patient. He had no rectal toxicity. The magnitude of table displacement necessary to match the prostate gold fiducial marker frequently exceeded the CTV/PTV margins (0.4 cm) before the first (35%) and the second arc (15%). Inter- and intra-fraction bladder and rectum volume variations did not correlate with prostate displacement.ConclusionMajor prostate position variations were reported. In-room kV fiducial imaging before each arc seems mandatory. Intra-fraction imaging of the OARs appears unnecessary. We suggest that only one CBCT is needed before the first arc.Trial registrationNCT02361515, February 11th, 2015.

Short-term efficacy between open-wedge high tibial osteotomy applying absorbable spacer implantation combined with proximal fibular osteotomy and unicompartmental knee arthroplasty: medial interventricular knee osteoarthritis

Purpose: To evaluation the short-term efficacy of Open-Wedge HTO with absorbable spacer implantation and Proximal Fibular Osteotomy and UKA (Unicompartmental Knee Arthroplasty) for targeting medial interventricular knee osteoarthritis.

Prospective 2-year Data Collection of the First 10 Patients After Ankle Spacer Implantation

Prospective 2-year Data Collection of the First 10 Patients After Ankle Spacer Implantation

Subacromial balloon spacer implantation for patients with massive irreparable rotator cuff tears achieves satisfactory clinical outcomes in the short and middle of follow-up period: a meta-analysis.

This meta-analysis was performed systematically to evaluate the efficacy of subacromial balloon spacers for patients with massive, irreparable rotator cuff tears. Electronic databases, including Medline/PubMed, Embase and Cochrane Library, were systematically searched to identify studies evaluating the efficacy of subacromial spacers for patients with irreparable or massive rotator cuff tears. Meta-analyses were performed to pool the outcome estimates of interest, such as the total constant score (TCS) and its sub-score (pain, activities of daily living [ADL], range of motion [ROM], and strength), Oxford shoulder score (OSS), American Shoulder and Elbow Society scores (ASES) and numeric rating scale (NRS), as well as different outcomes at different time points in the follow-up period. Ten studies with a total of 261 patients involving 270 shoulders were deemed viable for inclusion in the meta-analysis. The combined results demonstrated significant improvements in the TCS at the final follow-up (pooled mean difference = 26.4, 95% confidence intervals [CIs] 23.3 to 29.5). A sensitivity analysis and subgroup analysis, which were implemented based on two factors, different follow-up points and sub-scores (pain, ADL, ROM, and strength), revealed a consistent trend. The combined shoulder motion results demonstrated significant improvements in the forward flexion and external rotation (0° abduction) variables rather than in the abduction and external rotation (90° abduction) variables. Additionally, significant improvements in the OSS and ASES and a decrease in the NRS were observed in the middle of the follow-up period. This meta-analysis indicated that subacromial balloon spacer implantation for patients with massive irreparable rotator cuff tears may achieve satisfactory outcomes between 3months and 3years of follow-ups. Although the short- and middle- term effect is significant, the long-term effect needs to be confirmed by large-sample randomized controlled trial. IV.

Rotator Cuff Reconstruction Using Fascia Lata Patch Autograft for the Nonrepairable Rotator Cuff Tear

A large to massive rotator cuff tear is a common issue that lacks reliable options to return a patient's range of motion and function when conservative treatment has failed. With up to 96% of massive rotator cuff repairs failing within the first 6 months of repair, surgeons have been searching for a reliable treatment option for this difficult subset of patients. Surgical options for massive, retracted rotator cuff tears include re-establishing the counterforce coupling of the rotator cuff with techniques such as a partial repair or superior capsular reconstruction, preventing superior humeral migration as seen with balloon spacer implantation, and eliminating pain generators with techniques such as biceps tenotomy; however, these do not reconstitute dynamic cuff control. More recently, an acellular dermal allograft, as seen in superior capsular reconstruction, has been used to reconstruct the remaining rotator cuff. We describe a technique using a fascia lata autograft to reconstruct the rotator cuff in the setting of a massive cuff tear. This is of particular importance in centers that lack the funding or institutional approval to use acellular dermal allografts that have been popularized to date.

Does the use of a closed-suction drain reduce the effectiveness of an antibiotic-loaded spacer in two-stage exchange Arthroplasty for Periprosthetic hip infection? A prospective, randomized, controlled study

BackgroundThere is a concern regarding the use of a closed-suction drain (CSD) in two-stage exchange arthroplasty for periprosthetic joint infection as it may decrease the antibiotic concentrations in the joint fluids. The purpose of this study was to identify whether the use of a CSD could reduce local antibiotic concentrations following spacer implantation.MethodsA prospective, randomized, controlled trial was conducted at our institution between January 2018 and November 2018. We enrolled 32 patients undergoing two-stage exchange arthroplasty for periprosthetic hip infection with an interim cement spacer containing 4-g vancomycin and 2-g meropenem per 40-g methyl-methacrylate cement polymer. Patients were randomized and evenly divided into the study group (non-CSD) and control group (CSD group) by sealed envelopes. Drainage samples of joint fluids (n = 160) were collected every 24 h for the first five days following spacer implantation. The antibiotic concentrations of drainage samples were measured by high-performance liquid chromatography, and the bioactivities of the drainage samples against methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) and E. coli were assessed.ResultsThere was no significant difference in the decrease of vancomycin (study group vs. control group: 163.20 ± 77.05 vs. 162.39 ± 36.31; p = 0.917) and meropenem concentration (123.78 ± 21.04 vs. 117.27 ± 19.38; P = 0.548) between the two groups during the first five days following spacer implantation. All joint drainage samples in each group exhibited antibacterial activity against MSSA, MRSA and E. coli.ConclusionsThe use of CSD following the implantation of an antibiotic-loaded cement spacer does not reduce the effectiveness of such a spacer in two-stage exchange arthroplasty.(Chinese Clinical Trial Registry, ChiCTR-INR-17014162. Registered 26 December 2017.)

Reconstruction osseuse métacarpienne par membrane induite sans ciment

Hand ballistics traumas often produce complex limb injuries and large segmental bone defects. The induced membrane (IM) technique is a simple and effective procedure for reconstruction of segmental bone defects. Usually polymethylmethacrylate (PMMA) cement is required for the first stage of the surgery. We describe four metacarpal bone reconstructions with the IM technique but without PMMA cement after ballistic trauma in a low-resources setting. Two patients were treated in a forward surgical unit for gunshot wounds of the hand. A 33 years old man presented a 4th and 5th metarcarpal bone fracture with critical bone defect and a 25 years old man presented a 2nd and 3rd metacarpal bone and soft tissue defect. In addition to the surgical initial management, we performed the IM technique with a syringe's body in polypropylene (PP) instead of PMMA cement that was not available in this situation. A thick membrane was observable six weeks after the spacer implantation. We performed the bone graft in one case with an iliac crest and in the other with a tibial cortical and cancelous graft. Bone union was achieved in the two cases for the four metacarpal bones. We report cases treated in an austere environment where PMMA cement was not available. This PP induced membrane technique as first been described in a public communication at the SICOT congress by Mozumder et al. It involved critical bone defects from the lower limb. The IM technique has proven its efficiency in hand and wrist bone defect reconstruction but its success is based on strict compliance with technical execution. Our plastic spacers met the requirements of surgical technique. After six weeks, an IM membrane macroscopically similar to cement's IM was found in all cases. The PP spacer shows interesting characteristics: it does not contain antibiotics, it does not heat the surrounding tissues and it is not expensive and easily available. The use of a PP spacer allowed us to achieve bone union in four critical metacarpal bone defects related to ballistic trauma. This procedure respects the technical execution of the IM technique. It is achievable in very low-resources settings. Further biomolecular studies are necessary to assess the PP IM biological properties.

Treatment of Periprosthetic Infection with Silver-Doped Implants Based on Two-Dimensionally Ordered Linear Chain Carbon

Relevance. Formation of pan-resistance microorganisms, microbial biofilms on implants and recurrent infection rate stimulate the search for optimal prosthesis materials for treatment of periprosthetic infection (PJI). Purpose of the study — to compare the efficiency of two stage PJI treatment with simultaneous implantation of a spacer in combination with implants with silver-doped coatings based on two-dimensionally ordered linear chain carbon (TDOLCC+Ag) during the first stage and the conventional revision with a spacer only. Materials and methods. The study included 72 patients with PJI of the knee (n = 42) and hip (n = 30) joints. Control group (conventional revision) consisted of 35 patients and the main group (TDOLCC+Ag coated implant incorporated in a spacer) — 37 patients. Mean age of the patients was 61 years. Temporary components were replaced by the final components during revision at the second stage. Evaluation methods: clinical, X-ray, laboratory, microbiological and follow up history. Results. Inflammation markers and synovial fluid cytosis in the groups at the first revision stage featured equal high base values. During the second stage leucocyte count and cytosis reached normal values, ESR decreased twofold in both groups, CRP decreased five times in the main group. Throat and nasal swabs demonstrated growth of Staphylococcus aureus at 24,3-32,4% in both groups. The leading inducer of PJI was staphylococcal flora with MRSA share of 7,1% and MRSE — from 62,5 to 66,7%. End-points of evaluating treatment outcomes were revision spacer implantation at the second stage of sanation and recurrent PJI. Control group featured implantation of more revision spacers (5) as compared to the main group (1) after the treatment. Two recurrent PJIs were reported for the control group in 11 months while no recurrent infection was reported for the main group. Conclusion. The study demonstrated statistically significant improvement in the outcomes of PJI treatment by spacers with implants coated by TDOLCC+Ag as compared to the conventional treatment option.

Open-Wedge HTO with Absorbable β-TCP/PLGA Spacer Implantation and Proximal Fibular Osteotomy for Medial Compartmental Knee Osteoarthritis: New Technique Presentation

Purpose The purpose of this study was to present a new absorbable spacer for medial compartmental knee osteoarthritis (OA). The functional and radiographic results of patients treated with the novel surgical technique were also evaluated to investigate its clinical feasibility. Methods Patients with medial compartmental knee OA who underwent open-wedge high tibial osteotomy (HTO) with absorbable β-TCP/PLGA [30% beta-tricalcium phosphate and 70% poly (lactic-co-glycolic acid)] spacer implantation and proximal fibular osteotomy from January 2016 to February 2017 were retrospectively analyzed. The operation time, blood loss, and relevant complications were reviewed. The femorotibial angle (FTA), varus angle (VA), joint line convergence angle (JLCA), American Knee Society Score (KSS), and visual analog scale (VAS) score were recorded preoperatively and at the final follow-up, respectively. Results At the final follow-up, the mean FTA and JLCA were 179.85° ± 4.34° and 2.44° ± 1.26°, respectively, which were smaller than the preoperative values (182.94° ± 3.86° and 4.12° ± 1.65°, respectively; both p < 0.001). The final VA and VAS score were lower than those measured preoperatively (both p < 0.001). The clinical and functional KSSs at the final follow-up were higher than the preoperative scores (p < 0.001). Conclusions This novel absorbable spacer could provide adequate stability for the tibial osteotomy gap, at a lower cost than a traditional plate. With the use of this spacer as an osteoinductive and biodegradable device, secondary surgery for fixation removal could be avoided. The novel surgical technique could improve both the radiographic appearance and the function of the knee in patients with knee OA.

Kinematics of a Pyrocarbon Ankle Spacer for the Treatment of Arthritic Disease

Category:Ankle, Ankle ArthritisIntroduction/Purpose:Treatment options for ankle arthritis in younger patients are currently limited. Since the longevity of modern total ankle replacements is not sufficient for this patient population, ankle arthrodesis is typically utilized when joint preserving treatment is not a viable option. A new procedure using a pyrocarbon ankle spacer has been developed as a potential alternative, allowing for talar articular resurfacing for pain relief with minimal bone resection. The objective of this study was to assess whether this pyrocarbon ankle spacer could provide normal ankle kinematics as the native ankle joint using cadaveric gait simulation.Methods:Five mid-tibia cadaveric specimens without deformity and no history of lower limb injury or surgery were utilized. The stance phase of gait was simulated for each specimen using a six degree-of-freedom robotic device. A force plate was moved relative to stationary specimen through an inverse tibial kinematic path calculated from in vivo data while extrinsic tendons were actuated using physiologic loads (Figure 1A). Magnitudes of load were scaled to that of 25% bodyweight. Ankle kinematics were measured from reflective markers attached to the tibia and talus via surgical pins. The pyrocarbon ankle spacer (Exactech, Gainesville, FL, USA) was implanted in a nest formed 3-4 mm in depth on the talar articular surface using a custom burring technique (Figure 1B). Ankle spacer kinematics were compared to 95% confidence intervals of native, intact ankle joint kinematics to assess agreement.Results:Outcomes revealed no significant difference in ankle joint kinematics between the native, intact condition and post- pyrocarbon spacer implantation (Figure 1C). This result was consistent for the sagittal, coronal and axial planes of motion.Conclusion:The results of this study demonstrate that a pyrocarbon spacer permits normal ankle kinematics. Further, the device was observed to be stable in the joint throughout simulations. While the testing was performed at 25% bodyweight for analyses on all specimens, load magnitudes were also increased up to 75% on a subset of specimens and the structural integrity of the device remained pristine. With these findings, we concluded that the pyrocarbon spacer device offers promising potential as a treatment option for ankle arthritis.