Shoulder external rotation contracture following neonatal brachial plexus injury.

BACKGROUND: Glenohumeral posterior external rotation contractures and scapular winging are frequently overlooked problems in residual neonatal brachial plexus injury (NBPI). Recent attention has emphasized their impact on vital functions such as feeding and hygiene. This study aims to present the epidemiology of posterior glenohumeral (GH) contractures in a significant pediatric NBPI population and explore contributing factors. METHODS: We conducted a retrospective analysis of data collected from January 2019 to November 2022, involving a case series of 262 children with residual NBPI. The data included demographics, palsy level, prior surgical history, and the modified Mallet scale. Glenohumeral passive internal rotation in abduction (IRABD) and cross-body adduction (CBADD) angles were measured bilaterally. Subjects were categorized into 'Belly-' (Mallet Hand-to-Belly <3) and 'Belly+' (Mallet Hand-to-Belly ≥3) groups. RESULTS: Median participant age was 7.9 years (range: 3.5 - 21 years). Extension injury patterns included Erb's palsy (56.5%), extended Erb's palsy (28.6%), and global palsy (14.9%). Contractures exceeding 10, 20, and 30 degrees were prevalent in both IRABD and CBADD angles. The 'Belly-' group (9.5%) demonstrated a significant reduction in both angles compared to the 'Belly+' group. Weak correlations were found between IRABD (r=0.390, p<0.0001) or CBADD (r=0.163, p=0.0083) angles and Mallet hand-to-abdomen item. Glenohumeral reduction and Hoffer procedures led to a notable decrease in CBADD angle, without affecting 'Belly-' prevalence. Global injuries exhibited decreased angles compared to Erb's group. CONCLUSIONS: External rotation glenohumeral contractures are prevalent in residual NBPI, impacting midline access. Surprisingly, history of glenohumeral procedures or extensive injuries did not increase the likelihood of losing the ability to reach the belly. ROC analysis suggests specific thresholds for maintaining this ability.

Are silver-coated megaprostheses superior to uncoated megaprostheses in managing chronic end-stage periprosthetic hip and knee infection?

INTRODUCTION: Outcomes for silver coated megaprostheses (SC-MP) used in cases of end-stage periprosthetic joint infection (PJI) have not been clearly defined. Although attractive, concerns over implant longevity and the risk of infection relapse exist among the scientific community. Therefore, we sought to investigate the effect of silver coating in lower-extremity MPs used in such difficult-to-treat scenarios. The study's primary hypothesis was that the periprosthetic infection control rate would be higher in patients with silver-coated implants. MATERIALS AND METHODS: Non-interventional retrospective study with a historical comparison group. We identified all consecutive end-stage hip and knee PJI cases at our center managed with exchange arthroplasty using a silver-coated megaprosthesis from January 2016 to March 2021, these cases were compared with a historical cohort of end-stage PJI cases managed with uncoated megaprostheses. The main outcome studied was infection control rate. Secondarily, we analyzed the short-to-medium-term survivorship of this type of silver-coated implant. RESULTS: Fifty-nine megaprostheses used in cases of end-stage PJI were included in this study. We identified 30 cases of chronic hip or knee PJI in which a silver-coated modular megaprosthesis was implanted. Our non-coated megaprosthesis (NC-MP) historical group included 29 patients. Both groups had similar demographic characteristics. We found no statistically significant differences in infection control rate (80% vs. 82.8%, p = 0.47) or implant survivorship (90% vs. 89.65%, p = 1) after a mean follow-up for SC-MP of 46.43 months, and 48 months for the non-coated MP group. In relapsed cases, there were no differences in infection eradication after DAIR (66% SC-MP vs. 60% NC-MP success rate, p = 1). During the follow-up we observed one case of skin argyria without further repercussion. CONCLUSION: We were unable to confirm our initial hypothesis that use of silver-coated implants in end-stage PJI scenarios may be associated with better outcomes in terms of infection control or implant survivorship.

Etiology and antimicrobial resistance patterns in chronic osteomyelitis of the tibia: an 11-year clinical experience.

PURPOSE: To analyze changes in tendency of etiology and of antimicrobial resistance patterns to most common local and systemic antibiotics in chronic osteomyelitis of the tibia (COM-T) in a Level I trauma center over an 11-year period. METHODS: A retrospective review including all patients with COM-T who were surgically treated from January 2009 to December 2019. Patients were divided into two period groups: 2009-2014 and 2015-2019. Microbiologic etiology was analyzed. Bacterial resistance patterns evaluation was based on the Magiorakos et al. classification, including proportions of multidrug-resistant organisms (MDROs, acquired non-susceptibility to at least one agent in three or more antimicrobial categories), extensively drug-resistant (XDR) and pan drug-resistant (PDR) organisms encountered. RESULTS: A total of 173 episodes of COM-T were identified. Monomicrobial infections represented 47.4% of all cases, while 28.3% had polymicrobial infections. Negative deep-bone cultures were identified in 24.3% of the patients. The most commonly isolated microorganisms were coagulase-negative Staphylococci (24.5%) and S. aureus (20.5%). No differences were found when comparing Gram-positive infections between periods (58.3% for 2009-2014 vs. 46.7% for 2015-2019; p = 0.10). Findings were similar for Gram-negative infections (37% vs. 33.7%; p = 0.62), although more polymicrobial infections were detected (24.7% vs. 33.3%, respectively; p = 0.359). MDROs were involved in 15% of the cases, with an upward trend when comparing both periods (12.8% vs. 23.6%; p = 0.07). The most-used combination of local antibiotics-glycopeptide (vancomycin) plus aminoglycoside (gentamicin or tobramycin)-was met with low rates of resistance in the most frequently isolated microorganisms. CONCLUSION: According to the results of the present study, rates of Gram-positive and Gram-negative infections remained consistent during the two study periods, but with an upward trend in MDRO and polymicrobial infections detected. The local combination of a glycopeptide plus an aminoglycoside was effective in treating the most frequently isolated microorganisms.

Prosthetic joint infection caused by an atypical gram-negative bacilli: Odoribactersplanchnicus.

Prosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty. Its management consists of both: a radical debridement and implant retention or exchange (depending on the timing of symptoms) and directed antibiotic therapy. Thus, the isolation of atypical microorganisms implies a challenge, where anaerobes are responsible for only 4% of cases. However, Odoribacter splanchnicus has not been reported as a cause of PJI yet. We present an 82 year-old woman who was diagnosed with hip PJI. A radical debridement, prosthetic withdrawal, and spacer introduction was performed. Despite the directed antibiotic therapy against E. coli which was first isolated, the patient persisted clinically febrile. An anaerobic Gram-negative rod was isolated and finally, Odoribacter splanchnicus was identified and confirmed by 16S rRNA gene sequencing. Then, antibiotic bitherapy with ciprofloxacin and metronidazole was started until 6 weeks after surgery. The patient had no signs of infection recurrence after then. This case report also shows the importance of genomic identification of rare microorganisms causing PJI, and also allows setting a directed antibiotic therapy which is crucial for infection eradication.

Sequential repeated tibial tubercle osteotomy in a two-stage exchange strategy: a superior approach to treating a chronically infected knee arthroplasty?

PURPOSE: Surgical approach can impact the reliability of the debridement after a chronic total knee periprosthetic joint infection (PJI), a factor of utmost importance to eradicate the infection. The most adequate knee surgical approach in cases of PJI is a matter of debate. The purpose of this study was to determine the influence of performing a tibial tubercle osteotomy (TTO) in a two-stage exchange protocol for knee PJI treatment. METHODS: Retrospective cohort study examining patients managed with two-stage arthroplasty due to chronic knee PJI (2010-2019). Performance and timing of the TTO were collected. Primary end-point was infection control with a minimum FU of 12 months and according to internationally accepted criteria. Correlation between TTO timing and reinfection rate was reviewed. RESULTS: Fifty-two cases were finally included. Overall success (average follow-up: 46.2 months) was 90.4%. Treatment success was significantly higher among cases addressed using TTO during the second stage (97.1% vs. 76.5%, p value 0.03). Only 4.8% of the patients relapsed after performing a sequential repeated TTO, that is, during both first and second stages, compared to 23.1% cases in which TTO was not done (p value 0.28). No complications were observed among patients in the TTO group with a significant decrease in soft tissue necrosis (p: 0.052). CONCLUSION: Sequential repeated tibial tubercle osteotomy during a two-stage strategy is a reasonable option and offers high rates of infection control in complex cases of knee PJI with a low rate of complications.

Three-stage limb salvage in tibial fracture related infection with composite bone and soft-tissue defect.

INTRODUCTION: Managing critical-sized tibial defects is one of the most complex challenges orthopedic surgeons face. This is even more problematic in the presence of infection and soft-tissue loss. The purpose of this study is to describe a comprehensive three-stage surgical protocol for the reconstruction of infected tibial injuries with combined bone defects and soft-tissue loss, and report the clinical outcomes. MATERIALS AND METHODS: A retrospective study at a specialized limb reconstruction center identified all patients with infected tibial injuries with bone and soft-tissue loss from 2010 through 2018. Thirty-one patients were included. All cases were treated using a three-stage protocol: (1) infected limb damage control; (2) soft-tissue coverage with a vascularized or local flap; (3) definitive bone reconstruction using distraction osteogenesis principles with external fixation. PRIMARY OUTCOMES: limb salvage rate and infection eradication. SECONDARY OUTCOMES: patient functional outcomes and satisfaction. RESULTS: Patients in this series of chronically infected tibias had been operated upon 3.4 times on average before starting our limb salvage protocol. The mean soft-tissue and bone defect sizes were 124 cm2 (6-600) and 5.4 cm (1-23), respectively. A free flap was performed in 67.7% (21/31) of the cases; bone transport was the selected bone-reconstructive option in 51.7% (15/31). Local flap failure rate was 30% (3/10), with 9.5% for free flaps (2/21). Limb salvage rate was 93.5% (29/31), with infection eradicated in all salvaged limbs. ASAMI bone score: 100% good/excellent. Mean VAS score was 1.0, and ASAMI functional score was good/excellent in 86% of cases. Return-to-work rate was 83%; 86% were "very satisfied" with the treatment outcome. CONCLUSION: A three-stage surgical approach to treat chronically infected tibial injuries with combined bone and soft-tissue defects yields high rates of infection eradication and successful limb salvage, with favorable functional outcomes and patient satisfaction.

Role of asymptomatic bacteriuria on early periprosthetic joint infection after hip hemiarthroplasty. BARIFER randomized clinical trial.

PURPOSE: To evaluate preoperative asymptomatic bacteriuria (ASB) treatment to reduce early-periprosthetic joint infections (early-PJIs) after hip hemiarthroplasty (HHA) for fracture. METHODS: Open-label, multicenter RCT comparing fosfomycin-trometamol versus no intervention with a parallel follow-up cohort without ASB. PRIMARY OUTCOME: early-PJI after HHA. RESULTS: Five hundred ninety-four patients enrolled (mean age 84.3); 152(25%) with ASB (77 treated with fosfomycin-trometamol/75 controls) and 442(75%) without. Despite the study closed without the intended sample size, ASB was not predictive of early-PJI (OR: 1.06 [95%CI: 0.33-3.38]), and its treatment did not modify early-PJI incidence (OR: 1.03 [95%CI: 0.15-7.10]). CONCLUSIONS: Neither preoperative ASB nor its treatment appears to be risk factors of early-PJI after HHA. ClinicalTrials.gov Identifier: Eudra CT 2016-001108-47.

Vancomycin-Gentamicin Prefabricated Spacers in 2-Stage Revision Arthroplasty for Chronic Hip and Knee Periprosthetic Joint Infection: Insights Into Reimplantation Microbiology and Outcomes.

BACKGROUND: Second-stage positive cultures in 2-stage revision arthroplasty are a matter of concern, as their influence in outcomes is not clearly defined. We sought to study reimplantation microbiology when using vancomycin-gentamicin prefabricated cement spacers in hip and knee periprosthetic joint infection. The associations of second-stage positive cultures with treatment failures and patient-associated factors were analyzed. METHODS: We conducted a retrospective cohort study, examining patients managed with 2-stage revision arthroplasty due to knee or hip chronic periprosthetic joint infection between 2010 and 2017. Prefabricated vancomycin-gentamicin cement spacers were used during the spacer stage. Intraoperative microbiological culture results after the first and second stages were evaluated. The primary end point was infection eradication or relapse. RESULTS: A total of 108 cases were included (61 hips and 47 knees). And 22.2% of patients had ≥1 second-stage positive culture, while 9.3% had ≥2 positive samples. Overall success, at an average follow-up of 46.4 months, was 77.8%. Treatment failure was higher among cases with positive cultures (15.5% vs 45.8%, P < .01) regardless of the number of positive samples. Diabetes was identified as a risk factor for second-stage positive cultures (P = .03); use of cement loaded with extra antibiotics for spacer fixation showed a protective effect (P < .01). CONCLUSION: Second-stage positive cultures were related to a higher failure rate when using vancomycin-gentamicin cement spacers. Diabetes increased the likelihood of second-stage positive cultures. The use of extra-antibiotic-loaded cement for spacer fixation during the first stage showed a protective effect.

Uniplanar versus biplanar monolateral external fixator knee arthrodesis after end-stage failed infected total knee arthroplasty: a comparative study.

BACKGROUND: External fixator knee arthrodesis is a salvage procedure used primarily in cases of end-stage infected total knee replacement (iTKR). Stable fixation combined with bone-end compression is essential to achieve knee fusion, but providing sufficient stability can be challenging in the presence of severe bone loss. Our hypothesis is that using an external fixation biplanar configuration would bring about a fusion rate superior to that of a monolateral frame. METHODS: This study compares outcomes of biplanar external fixator knee fusion due to non-revisable iTKR with those of a historical cohort control study with patients managed with a monoplanar configuration. Primary endpoints were fusion rate, time to achieve bone fusion and infection eradication rate. Limb-length discrepancy, pain level, patient satisfaction and health-related quality of life were evaluated. RESULTS: A total of 29 knee fusion cases were included. In the biplanar group, infection was eradicated in 100% of the patients and fusion was achieved in all cases within an average of 5.24 months. In comparison, in the monolateral group, infection was eradicated in 86% of the cases and fusion was achieved in 81% of the patients after a mean of 10.3 months (p < 0.05). In both groups, postoperative pain was mild and patients expressed a high degree of satisfaction once fusion was achieved. CONCLUSIONS: According to our data, external fixation knee fusion is a useful limb-salvage procedure in end-stage cases of knee PJI. We conclude that a biplanar configuration can halve the time required to achieve solid bone fusion in such a complex scenario.

Vascularized humeral periosteal flap to treat lateral humeral condyle nonunion: An anatomical study and report of two successfully-treated pediatric cases.

PURPOSE: Nonunion is a common complication of lateral condyle humeral (LCH) fractures in children. In situ fixation with a screw and bone grafting is the classically-recommended method of treatment. The purpose of this study is to analyze the feasibility of obtaining a vascularized periosteal flap obtained from the lateral humerus and based on the posterior collateral radial vessels (PCRV). Second, to report the results after the application in two pediatric cases. METHODS: Periosteal branches of PCRV were studied in ten upper limbs from fresh human cadavers. Then, two children with LCH nonunion were treated with this flap. RESULTS: The PCRV provided mean of 5.3 anterior periosteal branches (range 4-7) with a mean distance between them of 19.1 mm (range 5-29 mm) and 5.7 posterior periosteal branches (range 3-7) with a mean distance between them of 15.9 mm (range 6-33 mm. PCRV distally anastomosed to the interosseous recurrent artery and the radial recurrent artery, creating a vascular net over the lateral condyle and allowing for the design of a reverse vascularized humeral periosteal flap (VHPF). Abundant periosteal callus and rapid consolidation were achieved in both children. No bone fixation or grafting was necessary. CONCLUSIONS: VHPF might be considered a viable biological surgical option to promote bone healing in LCH nonunions in children, while avoiding the need for bone fixation and the donor morbidity associated with bone grafting.

Acute periprosthetic joint infection due to Fusobacterium nucleatum in a non-immunocompromised patient. Failure using a Debridement, Antibiotics + Implant retention approach.

Fusobacterium nucleatum is an obligately anaerobic gram-negative rod, a component of the microbiome of the oropharynx and the gastrointestinal and urogenital tracts, causing an array of human infections which often include periodontal pathologies. As far as we know, there are no previous publications about acute periprosthetic joint infection due to Fusobacterium sp.; we report the first case in the medical literature of an aggressive, acute knee prosthetic infection due to F. nucleatum in a non-immunocompromised patient, unsuccessfully treated with a DAIR approach (Debridement + Antibiotics + Implant Retention).

Use of modular megaprosthesis in managing chronic end-stage periprosthetic hip and knee infections: Is there an increase in relapse rate?

BACKGROUND: Bone loss is a common problem in periprosthetic joint infection (PJI) scenarios. Modular megaprosthesis (MP) could offer a limb salvage solution in such situations. Concerns about risk of infection relapse, reinfection and implant longevity exist regarding MP use in cases of chronic PJI, rather than standard implants. We therefore sought to analyze our results with MP use in chronic PJI cases. METHODS: We performed a retrospective analysis of 29 MP patients. Inclusion criteria were the use of this type of modular megaimplant for reconstruction of segmental bone defects in chronically infected lower-extremity arthroplasties (hip or knee) and a minimum follow-up of 18 months. We evaluated the primary outcome of infection control or recurrence. The MPs were classified into 3 groups, according the bone segment replaced (proximal femur, distal femur or total femur). We further analyzed complications, pain, patient satisfaction and functional results. RESULTS: Mean age was 75 years; mean follow-up was 48 months (range 18-82). The most frequently involved pathogens were coagulase-negative staphylococci (62%). Polymicrobial infection was detected in 7 patients. Twenty-eight patients were managed with a two-stage approach. The infection-free rate at the end of follow-up was 82.8% (24 of 29 patients). Aside from infection relapse, the most frequent complication was dislocation. Final-point survival rate was 91.2% (CI 68.1-97.8). Clinical outcome data and satisfaction results were acceptable. CONCLUSION: According our data, MP is a useful tool in treating end-stage PJI cases, achieving acceptable eradication, satisfaction and implant survivorship rates.

Algorithm to Diagnose Delayed and Late PJI: Role of Joint Aspiration.

Total Joint Arthroplasty (TJA) continues to gain acceptance as the standard of care for the treatment of severe degenerative joint disease, and is considered one of the most successful surgical interventions in the history of medicine. A devastating complication after TJA is infection. Periprosthetic joint infection (PJI), represents one of the major causes of failure and remains a significant challenge facing orthopaedics today. PJI usually requires additional surgery including revision of the implants, fusion or amputations causing tremendous patient suffering but also a heavy health economics burden. PJI is at the origin of around 20-25 % of total knee arthroplasty (Bozic et al. 2010; de Gorter et al. 2015; Sundberg et al. 2015) and 12-15 % of total hip arthroplasty (Bozic et al. 2009; Garellick et al. 2014; de Gorter et al. 2015) failures.

Periprosthetic joint infection by Propionibacterium acnes: Clinical differences between monomicrobial versus polymicrobial infection.

OBJECTIVE: To compare a series of monomicrobial Propionibacterium acnes (P. acnes) knee and hip periprosthetic joint infection (PJI) cases with cases of polymicrobial PJI which included P. acnes. We hypothesized that the presence of a polymicrobial P. acnes infection would lead to worse outcomes than those in cases of monomicrobial P. acnes PJI. METHODS: Retrospective multicentre study. All patients with hip or knee PJIs including P. acnes diagnosed from August-2002 to July-2013 in two university hospitals were included. We collected demographic data, McPherson classification, local signs of infection (swelling or wound drainage), laboratory and histological data, surgical management, antibiotic treatment and outcomes. Data were compared between two groups: cases of monomicrobial P. acnes PJI, and cases of polymicrobial PJI involving P. acnes. RESULTS: Thirty-eight patients who presented with 38 PJIs were included; median age was 71 (IQR:62.5-79); 21 were men (55%); median follow-up was 42 months (IQR:17.5-58). Local signs of infection were present in 14 patients (36.8%); ESR>30 mm/h in 14 patients (36.8%); CRP>1 mg/dl in 15 patients (39.5%); 11 out of 25 patients (44%) had positive preoperative cultures from joint aspiration. Positive histologic studies (Feldman's criteria) were found in 5 out of 28 patients (17.8%). Twenty-four patients (63%) had monomicrobial PJIs; 14 patients (37%) had polymicrobial PJIs. There were no significant outcome differences between monomicrobial and polymicrobial PJIs cases; overall, the success rates were 79.2% and 85.7% respectively (P > 0.05). CONCLUSIONS: We did not find any significant differences between monomicrobial and polymicrobial P. acnes PJI outcomes. ESR, CRP and histologic study are established parameters for diagnosing PJI which did not prove useful in P. acnes PJI.

Free vascularized tibial periosteal graft with monitoring skin island for limb reconstruction: Anatomical study and case report.

Several types of vascularized periosteal flaps have recently been described for the treatment or prevention of complex non-union in pediatric patients. Among them, a vascularized tibial periosteal graft (VTPG), supplied by the anterior tibial vessels (ATV), has been used successfully as a pedicled flap in a few patients. The purpose of the study is to describe the periosteal branches of the ATV, as well as the cutaneous and muscular branches by means of an anatomical study. In addition, to report on the use of VTPG as a free flap with a monitoring skin island in a clinical case. A mean of 6.5 periosteal branches (range 5-7) were found. In all cases we located a cutaneous perforator branching from one of the periosteal branches located at the midlevel of the leg. We performed a two-stage reconstruction of a recalcitrant non-union and residual shortening of the right tibia in a 17-year-old boy. After nonunion focus distraction, we used a massive bone allograft fixed with a nail and covered by a VTPG as a biological resource. Allograft consolidation was achieved 5.5 months after surgery. At eighteen months after surgery, no complications were observed and the patient had resumed all his daily activities, despite a residual 2-cm limb-length discrepancy. VTPG may be considered as a valuable surgical option for bone reconstruction in complex biological scenarios in the young population. © 2015 Wiley Periodicals, Inc. Microsurgery 37:248-251, 2017.

Mid-Term Outcomes and Complications with Cementless Distal Locking Hip Revision Stem with Hydroxyapatite Coating for Proximal Bone Defects and Fractures.

We revised the first 100 revision total hip arthroplasties using a cementless distal locking revision stem conducted in our referral centre. Average follow-up was 9.2 years (range: 5.5-12 years). Harris Hip Score improved from 42.5 to 81.6, and none had thigh pain at last follow-up. No significant stress shielding, osteolysis, or radiologic loosening was found. All patients showed radiological evidence of secondary implant osseointegration. Overall survival was 97% with three patients being revised: two stem ruptures and one subsidence. We could trace these complications to technical errors. These findings suggest that a diaphyseal fixation of the revision stem with distal locking can provide the needed primary axial and rotational stability of the prosthesis. This would allow further bony ingrowth, enhanced by the hydroxyapatite coating.

Vascularized tibial periosteal graft in complex cases of bone nonunion in children.

Bone nonunion in the pediatric population usually occurs in the context of highly unfavorable biological conditions. Recently, the vascularized fibular periosteal flap has been reported as a very effective procedure for treating this condition. Even though a vascularized tibial periosteal graft (VTPG) was described long ago and has been successfully employed in one adult case, there has been no other report published on the use of this technique. We report on the use of VTPG, pedicled in the anterior tibial vessels, for the treatment of two complex pediatric bone nonunion case: a recalcitrant supracondylar femoral pseudarthrosis secondary to an infection in an 11-year-old girl, and a tibial nonunion secondary to a failed bone defect reconstruction in a 12-year-old girl. Rapid healing was obtained in both cases. In the light of the data presented, we consider VTPG as a valuable surgical option for the treatment of complex bone nonunions in children.

Industrially prefabricated cement spacers: do vancomycin- and gentamicin-impregnated spacers offer any advantage?

BACKGROUND: Industrially preformed antibiotic-loaded cement spacers are useful to facilitate the second stage of two-stage exchange arthroplasty for infected THAs and TKAs. However, whether gentamicin alone or a combination of antibiotics (such as vancomycin and gentamicin) is more effective is not known. QUESTIONS/PURPOSES: We therefore sought to compare industrially prefabricated spacers containing either gentamicin or gentamicin and vancomycin with respect to (1) infection control, (2) complications, and (3) quality of life, pain, and patient satisfaction. METHODS: We performed a review of 51 patients with chronic infections treated at one center using either gentamicin or vancomycin and gentamicin-prefabricated spacers. The former were used exclusively from January 2006 until May 2009, and the latter from June 2009 until July 2011, and there was no overlap. We collected data on demographics, immunologic status (McPherson classification), prosthetic joint infection location, type of prosthesis, microbiologic results, and time between stages. We evaluated the primary outcome of infection control or recurrence after at least 12 months followup. We also recorded complications. Each patient completed a quality-of-life survey, VAS, and a self-administered satisfaction scale. RESULTS: The overall infection control rate was 83% after a mean followup of 35 months (range, 12.4-64.7 months). There were no differences between gentamicin and vancomycin and gentamicin spacers in terms of infection eradication (80 % versus 85 %, respectively; p = 0.73), nor in terms of complications, quality of life, pain, or satisfaction scores. CONCLUSIONS: Prefabricated, antibiotic-loaded cement spacers has been proven effective for infection control in TKAs and THAs but with the numbers available, we did not find any differences between a gentamicin or vancomycin and gentamicin-prefabricated spacer, and therefore, we are unable to validate the superiority of the combination of vancomycin and gentamicin over gentamicin alone. Because of the higher costs involved with vancomycin and gentamicin spacers, and the potential risks of unselective use of vancomycin, further comparative studies are necessary to evaluate their role in the treatment of infected THAs or TKAs. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Antibiotic susceptibility in gram-positive chronic joint arthroplasty infections: increased aminoglycoside resistance rate in patients with prior aminoglycoside-impregnated cement spacer use.

Two-stage revision using aminoglycoside-cement spacers (A-CSs) is widely used to manage chronic periprosthetic joint infection (PJI). However, aminoglycoside-resistance in gram-positive cocci (GPC) seems to be increasing. Moreover, the contribution of these A-CSs to select resistant mutants is a matter of concern. We study the antibiotic susceptibility profile of GPC after 113 chronic hip and knee PJIs. Aminoglycoside susceptibility-profiles were compared between cases where A-CSs had previously been used (n: 52), and cases of primary infection (n: 61). 32% of isolates were resistant to gentamicin and 40.6% to tobramycin. Gentamicin resistance after previous A-CS use was significantly higher (49.2% [30/61] vs. 19.3% [16/83]; P: 0.0001) as well as with tobramycin (52.7% [29/55] vs. 30.9% [21/66]; P: 0.014). A high rate of gentamicin-tobramycin resistance exists among the most common bacteria involved in chronic-PJI. The risk of selection for aminoglycoside-resistant mutants in cases of infection relapse is a concern following A-CS use.