Rare Bipolaris Species Fungal Periprosthetic Hip Infection in an Immunocompetent Host: A Case Report.

CASE: We present a case report of a 64-year-old man who developed a rare Bipolaris species fungal periprosthetic joint infection (PJI) after revision arthroplasty for complications associated with a metal-on-metal total hip arthroplasty. The patient underwent a 2-stage debridement with antibiotic bead placement and implant retention, along with chronic antifungal suppression. At the 2-year follow-up, the patient remained asymptomatic. CONCLUSION: Fungal PJI with filamentous fungi such as Bipolaris species is a rare clinical entity. This case report highlights the clinical presentation and management of this rare condition.

How Does Orthopaedic Surgeon Gender Representation Vary by Career Stage, Regional Distribution, and Practice Size? A Large-Database Medicare Study.

BACKGROUND: Orthopaedic surgery has the lowest proportion of women surgeons in practice of any specialty in the United States. Preliminary studies suggest that patients who are treated by physicians of the same race, ethnicity, cultural background, or gender feel more comfortable with their care and may have better outcomes. Therefore, understanding the discrepancies in the diversity of the orthopaedic surgeon workforce is crucial to addressing system-wide healthcare inequities. QUESTIONS/PURPOSES: (1) Does a difference exist in gender representation among practicing orthopaedic surgeons across geographic distributions and years in practice? (2) Does a difference exist in gender representation among practicing orthopaedic surgeons with regard to rural-urban setting, group practice size, and years in practice? METHODS: Orthopaedic surgeons serving Medicare patients in 2017 were identified in the Medicare Physician and Other Supplier Public Use File and Physician Compare national databases. This dataset encompasses more than 64% of practicing orthopaedic surgeons, providing a low proportion of missing data compared with other survey techniques. Group practice size, location, and Rural-urban Commuting Area scores were compared across physician gender and years in practice. Linear and logistic regressions modeled gender and outcomes relationships adjusted by years in practice. Least-square means estimates for outcomes were calculated by gender at the median years in practice (19 years) via regression models. RESULTS: According to the combined Medicare databases used, 5% (1019 of 19,221) of orthopaedic surgeons serving Medicare patients were women; this proportion increased with decreasing years in practice (R 2 0.97; p < 0.001). Compared by region, the West region demonstrated the highest proportion of women orthopaedic surgeons overall (7% [259 of 3811]). The Midwest and South regions were below the national mean for proportions of women orthopaedic surgeons, both overall (5% [305 of 6666] and 5% [209 of 4146], respectively) and in the first 5 years of practice (9% [54 of 574] and 9% [74 of 817], respectively). Women worked in larger group practices than men (median [interquartile range] 118 physicians [20 to 636] versus median 56 [12 to 338]; p < 0.001, respectively). Both genders were more likely to practice in an urban setting, and when controlling for years in practice, there was no difference between men and women orthopaedic surgeons practicing in rural or urban settings (respectively, R 2 = 0.0004 and 0.07; p = 0.89 and 0.09). CONCLUSION: Among orthopaedic surgeons, there is only one woman for every 20 men caring for Medicare patients in the United States. Although gender representation is increasing longitudinally for women, it trails behind other surgical subspecialties substantially. Longitudinal mentoring programs, among other evidenced initiatives, should focus on the more pronounced underrepresentation identified in Midwestern/Southern regions and smaller group practices. Gender-based equity, inclusion, and diversity efforts should focus on recruitment strategies, and further research is needed to study how inclusion and diversity efforts among orthopaedic surgeons improves patient-centered care. LEVEL OF EVIDENCE: Level III, therapeutic study.

Periosteal chondrosarcoma: an unusual juxtacortical sarcoma.

Periosteal chondrosarcoma is a rare tumor. It can be difficult to diagnose radiographically and pathologically and can be confused with periosteal osteosarcoma; however, the treatment of these two lesions is quite different. Increased awareness of imaging features of this lesion, particularly those that can help differentiate it from other surface-based tumors, can help one recognize this entity. We report the case of a periosteal chondrosarcoma in a young woman, highlighting the diagnostic imaging features of this disease, and her treatment with a joint-sparing geometric resection of the distal femur, using patient-specific 3D-printed cutting guides and matched allograft reconstruction.

What are the 2-year survivorship outcomes of custom hemipelvis reconstruction after hemipelvectomy and revision arthroplasty? The evolution of a custom ilium "monoflange".

BACKGROUND: Innovations in machined and three-dimensionally (3D) printed implant technology have allowed for customized complex pelvic reconstructions. We sought to determine the survivorship of custom hemipelvis reconstruction using ilium-only fixation at a minimum 2-year follow-up, their modes of failure, and the postoperative complications resulting from the procedure. METHODS: A retrospective review identified 12 consecutive patients treated with custom hemipelvis reconstruction. Indications for surgery were bone tumor requiring internal hemipelvectomy (four patients) or multiply revised, failed hip arthroplasty with massive bone loss (eight patients). All patients had a minimum of 2-year follow-up with a mean of 60.5 months. Kaplan-Meier survivorship analysis was determined for all patients. Postoperative complications and reoperations were categorized for all patients. RESULTS: At a mean of 60.5 months, 11 of 12 patients had retained their custom implant (92% survivorship). One implant was removed as a result of an acute periprosthetic joint infection (PJI). There were no cases of aseptic loosening. Seven of 12 patients required reoperation (three PJI; two dislocations; two superficial wound complications), with five patients going on to reoperation-free survival. CONCLUSIONS: Custom hemipelvis reconstruction utilizing an ilium monoflange provides durable short-term fixation at a minimum 2-year follow-up. Reoperation for infection and dislocation is common.

A Contemporary Classification System of Femoral Bone Loss in Revision Total Hip Arthroplasty.

BACKGROUND: Current femoral bone loss classification systems in revision total hip arthroplasty were created at a time when the predominant reconstructive methods used cylindrical porous-coated cobalt-chrome stems. As these stems have largely been replaced by fluted-tapered titanium stems, the ability of these classification systems to help guide implant selection is limited. The purpose of this study was to describe a novel classification system based on contemporary reconstructive techniques. METHODS: We reviewed the charts of all patients who underwent femoral component revision at our institution from 2007 through 2019. Preoperative images were reviewed, and FBL was rated according to the Paprosky classification and compared to ratings using our institution's NCS. Rates of reoperation at the time of most recent follow-up were determined and compared. RESULTS: Four-hundred and forty-two femoral revisions in 330 patients with a mean follow-up duration of 2.7 years were identified. Femoral type according to Paprosky and NCS were Paprosky I (36, 8.1%), II (61, 13.8%), IIIA (180, 40.7%), IIIB (116, 26.2%), and IV (49 11.1%) and NCS 1 (35, 7.9%), 2 (364, 82.4%), 3 (8, 1.8%), 4 (27, 6.1%), and 5 (8, 1.8%). Of the 353 nonstaged rTHAs, there were 42 cases requiring unplanned reoperation (11.9%), including infection (18, 5.1%), instability (10, 2.8%), femoral loosening (5, 1.4%), and various other causes (9, 2.5%). The NCS was more predictive of reoperation than the Paprosky classification (Fisher's exact test, P = .008 vs P = ns, respectively). CONCLUSION: We present a novel femoral classification system that can help guide contemporary implant selection.

The Double DAIR: A 2-Stage Debridement with Prosthesis-Retention Protocol for Acute Periprosthetic Joint Infections.

BACKGROUND: Debridement and implant retention (DAIR) has variable success as a treatment for acute periprosthetic joint infection (PJI), with generally poor outcomes reported in the literature1. Because of the unacceptably high failure rate of DAIR, we implemented a 2-stage debridement protocol that includes the use of high-dose antibiotic beads between stages for the treatment of acute PJI. In 2 previous studies, with an average follow-up of 3.5 years in each study, we reported overall infection-control rates of 87% and 90%2,3. DESCRIPTION: Following exposure of the joint, cultures are obtained, and all modular components are removed, scrubbed, and soaked in an antiseptic solution. A thorough irrigation and debridement with complete synovectomy is performed, followed by temporary reinsertion of the original modular parts. High-dose antibiotic cement beads are inserted into the joint, and the joint is closed. Approximately 5 to 6 days later, a second debridement is performed, the beads are removed, and the new modular, sterile components are implanted. The patient is placed on a course of intravenous and, later, oral antibiotics, in addition to a standard postoperative rehabilitation protocol. ALTERNATIVES: Long-term suppressive antibiotic therapy.One-stage DAIR.One-stage exchange arthroplasty.Two-stage exchange arthroplasty.Resection arthroplasty.Amputation. RATIONALE: The treatment of acute PJI has historically consisted of a single irrigation and debridement, with exchange of modular parts and retention of the components, followed by intravenous antibiotic therapy. Despite having lower rates of patient morbidity compared with a 2-stage exchange arthroplasty, this more traditional procedure also has a higher rate of failure, with reported rates as high as 60% to 84%4-12. The utility of component retention continues to be a topic of debate13. Alternatives to component retention include both 1- and 2-stage exchange procedures. Although these modalities offer potentially higher rates of infection control, they are associated with substantial patient morbidity, particularly in patients with well-fixed implants14-16. Furthermore, exchange procedures may result in substantial iatrogenic bone loss, which can be problematic in revision total joint arthroplasty procedures, in which bone stock may already be limited. The double-DAIR protocol offers infection-control rates that are comparable with those of component-exchange procedures, but with the lower patient morbidity associated with component-retention procedures. Furthermore, the double-DAIR procedure provides the added benefit of retaining important bone stock. EXPECTED OUTCOMES: The success rate for the double-DAIR procedure has been reproducible, with infection-control rates of 87% and 90% reported in 2 studies from a single cohort at our institution2,3. These rates represent a substantial improvement compared with a single irrigation and debridement1, and are on par with those reported for 2-stage exchange arthroplasty procedures17-21. The infection-control rates of the double-DAIR procedure did not significantly vary depending on whether infection occurred following a total knee or total hip arthroplasty. However, not surprisingly, patients who underwent debridement following a revision procedure had a lower rate of success (77.1% successful infection control) compared with patients debrided following a primary procedure (93.8% successful infection control). We could not demonstrate an association with organism and success or failure of treatment.Although not significant, there was a trend toward an association between the time from symptom onset to initial treatment and infection control (p = 0.07)2. Patients with successful infection control underwent the initial debridement an average of 6.2 days after symptom onset, compared with 10.7 days in patients in whom treatment had failed. Several other studies have demonstrated that successful infection control is associated with earlier initial irrigation and debridement22-27. We strongly support that, in the setting of confirmed acute PJI, prompt initiation of treatment optimizes the chances for successful infection control. IMPORTANT TIPS: Thorough debridement is key to successful infection control of infection.Antibiotic-loaded bone cement has repeatedly been demonstrated to be safe, and we recommend its use28-31.Extended oral antibiotics following debridement with component retention can increase infection-free survivorship32.

Synovial fluid α defensin has comparable accuracy to synovial fluid white blood cell count and polymorphonuclear percentage for periprosthetic joint infection diagnosis.

AIMS: The aim of this study was to determine the diagnostic accuracy of α defensin (AD) lateral flow assay (LFA) and enzyme-linked immunosorbent assay (ELISA) tests for periprosthetic joint infection (PJI) in comparison to conventional synovial white blood cell (WBC) count and polymorphonuclear neutrophil percentage (PMN%) analysis. METHODS: Patients undergoing joint aspiration for evaluation of pain after total knee arthroplasty (TKA) or total hip arthroplasty (THA) were considered for inclusion. Synovial fluids from 99 patients (25 THA and 74 TKA) were analyzed by WBC count and PMN% analysis, AD LFA, and AD ELISA. WBC and PMN% cutoffs of ≥ 1,700 cells/mm3 and ≥ 65% for TKA and ≥ 3,000 cells/mm3 and ≥ 80% for THA were used, respectively. A panel of three physicians, all with expertise in orthopaedic infections and who were blinded to the results of AD tests, independently reviewed patient data to diagnose subjects as with or without PJI. Consensus PJI classification was used as the reference standard to evaluate test performances. Results were compared using McNemar's test and area under the receiver operating characteristic curve (AUC) analysis. RESULTS: Expert consensus classified 18 arthroplasies as having failed due to PJI and 81 due to aseptic failure. Using these classifications, the calculated sensitivity and specificity of AD LFA was 83.3% (95% confidence interval (CI) 58.6 to 96.4) and 93.8% (95% CI 86.2 to 98.0), respectively. Sensitivity and specificity of AD ELISA was 83.3% (95% CI 58.6 to 96.4) and 96.3% (95% CI 89.6 to 99.2), respectively. There was no statistically significant difference between sensitivity (p = 1.000) or specificity (p = 0.157) of the two AD assays. AUC for AD LFA was 0.891. In comparison, AUC for synovial WBC count, PMN%, and the combination of the two values was 0.821 (sensitivity p = 1.000, specificity p < 0.001), 0.886 (sensitivity p = 0.317, specificity p = 0.011), and 0.926 (sensitivity p = 0.317, specificity p = 0.317), respectively. CONCLUSION: The diagnostic accuracy of synovial AD for PJI diagnosis is comparable and not statistically superior to that of synovial WBC count plus PMN% combined. Cite this article: Bone Joint J 2021;103-B(6):1119-1126.

Modular Fluted Tapered Stems in Aseptic Oncologic Revision Total Hip Arthroplasty: A Game Changer?

BACKGROUND: Modular fluted tapered (MFT) stems are the most frequently used femoral component in revision total hip arthroplasties (THAs). Despite this, no data are available on how they perform in revision THA for oncologic salvage. This is a unique population, often with severe bone loss and prior radiation that extends the limits of uncemented femoral reconstruction. The aims of this study were to evaluate the implant survivorship, radiographic results, and clinical outcomes of MFT stems used for revision oncologic salvage. METHODS: We identified 17 patients treated initially with primary THA for an oncologic diagnosis (15 primary oncologic, 2 metastatic disease) who underwent subsequent femoral revision with an MFT stem. Mean age at revision was 66 years and 35% of patients were female. Mean follow-up was 4 years. Before revision, 5 of 17 had undergone local radiation. RESULTS: Ten-year survivorship free from aseptic loosening was 100%. The survivorship free of any reoperation was 76%. There were no femoral component fractures. Three patients were revised for recurrent instability, and 1 patient underwent irrigation and debridement for an acute infection. At most recent follow-up, no patient had radiographic evidence of progressive femoral component subsidence or failure of osteointegration. The mean Harris Hip Score improved from 29 preoperatively to 76 postoperatively (P < .0001). CONCLUSION: In this series of patients with cancer, many of whom had severe bone loss and/or prior local radiation, being treated with revision THA, there were no revisions for femoral component loosening and no cases of implant fracture. LEVEL OF EVIDENCE: III.

Comparative analysis of 23 synovial fluid biomarkers for hip and knee periprosthetic joint infection detection.

There is interest in novel synovial fluid biomarkers for the detection of periprosthetic joint infection (PJI). Here, we assessed the diagnostic accuracy of 23 simple or sophisticated synovial fluid biomarkers for periprosthetic hip or knee infection detection. One hundred seven subjects were studied, 57 of whom had aseptic failure (AF) and 50 PJI. The following synovial fluid biomarkers were tested using spectrophotometric assays, immunoassays, lateral flow tests, or test strips: leukocyte count, monocyte percentage, lymphocyte percentage, neutrophil percentage, C-reactive protein (CRP), glucose, lactate, granulocyte-macrophage colony-stimulating factor, interferon-γ, interleukin-1ß (IL-1ß), IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-17A, IL-23, tumor necrosis factor-α, α-defensin, and leukocyte esterase. The best-performing synovial fluid biomarkers to differentiate PJI from AF-that is, those with highest area under the curve compared to all other biomarkers-were leukocyte count, percent neutrophils and percent monocytes, CRP, and α-defensin (P < .0001).

Screening for Periprosthetic Joint Infections With ESR and CRP: The Ideal Cutoffs.

BACKGROUND: The purpose of this study was to (1) determine the sensitivity and specificity of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) when screening for a periprosthetic joint infection (PJI) using the standard MSIS cutoff of 30 mm/h and 10 mg/L, respectively, and (2) determine the optimal ESR and CRP cutoff to achieve a sensitivity ≥95%. METHODS: We retrospectively analyzed 81 PJI patients and 83 noninfected arthroplasty patients. We calculated the sensitivity and specificity (and 95% confidence intervals) for ESR and CRP at thresholds of 30 mm/h and 10 mg/L, respectively. We determined the optimal cutoff for both ESR and CRP to yield a sensitivity greater than or equal to 95%. RESULTS: The ESR cutoff that resulted in a sensitivity ≥ to 95% (95% CI: 85.2-97.6%) was 10 mm/h, and the CRP cutoff that resulted in a sensitivity ≥ to 95% (95% CI: 87.1-98.4%) was 5 mg/L. The sensitivity and specificity with a combined ESR and CRP of 10 mm/h and 5 mg/L was 100% (95% CI: 94.1-100%) and 54.7% (95% CI: 46.4-62.3%). CONCLUSION: When using ESR and CRP as a screening tool with the accepted cutoffs of 30 mm/h and 10 mg/L, there is an unacceptably low sensitivity and a high number of false negatives. Therefore, further recommendation must be given to lowering these thresholds to avoid the devastating morbidity of a missed PJI. LEVEL OF EVIDENCE: III.

Frequency, Cost, and Clinical Significance of Incidental Findings on Preoperative Planning Images for Computer-Assisted Total Joint Arthroplasty.

BACKGROUND: The frequency of incidental findings with computer-assisted total joint arthroplasty (CA TJA) preoperative imaging and their clinical significance are currently unknown. METHODS: We reviewed 573 patients who underwent primary CA TJA requiring planning imaging. Incidental findings were defined as reported findings excluding those related to the planned arthroplasty. Secondary outcomes were additional tests or a delay in surgery. Associated charges were obtained from our institution's website. Charge and incidence data were combined with TJA volumes obtained from the 2016 National Inpatient Sample to model costs to the healthcare system. RESULTS: Overall, 262 patients (45.7%) had at least 1 incidental finding, 144 patients (25.1%) had 2, and 65 (11.3%) had 3. The most common finding types were musculoskeletal (MSK, 67.7%), digestive (19.5%), cardiovascular (4.9%), and reproductive (4.7%). Also, 9.3% of patients had at least 1 non-MSK incidental finding. Both MSK and non-MSK incidental findings were more common with total hip arthroplasty compared to total knee arthroplasty (67.9% vs 42.2%, P < .0001, and 15.4% vs 8.3%, P < .05, respectively). Further testing was required in 6 cases (1.0%); 1 case required delay in surgery (0.2%). Using the 2016 volume of TJA procedures and assuming a 10%, 15%, and 25%, utilization rate of image-based CA TJA, the annual cost of additional testing was $2.7 million (95% confidence interval, $1.1-$6.3 million), $4.1 million ($1.6-$9.5 million), and $6.9 million (95% confidence interval, $2.7-$15.8 million), respectively. CONCLUSION: Incidental findings are relatively common on planning images. Stakeholders should be aware of the hidden costs of incidental findings given the increasing popularity of image-based CA TJA.

Robot Assisted Cystectomy With Holmium Laser Debridement for Osteomyelitis of the Pubic Symphysis With Urinary Fistula.

OBJECTIVE: To assess the success of robot-assisted holmium laser debridement of the pubic symphysis for osteomyelitis of the pubic symphysis with associated urosymphyseal fistula. Traditionally, excision of the fistulous tract and concomitant cystectomy with urinary diversion and pubic symphyseal debridement has been done using an open approach. This paper presents patients who were successfully managed with this approach. METHODS AND MATERIALS: Between January 2007 and January 2018, all patients who underwent pubic symphyseal debridement with or without cystectomy were identified. We reviewed patients who underwent planned robot-assisted cystectomy with holmium laser debridement for osteomyelitis of the pubic symphysis as a result of urinary fistula. Data on clinical presentation, perioperative outcomes, and recurrence of urinary tract fistula and symptoms were collected. RESULTS: Twelve patients underwent holmium laser debridement of the pubic symphysis during robot-assisted cystectomy for urinary fistula. Eleven patients had prior radiation treatments for prostate cancer with all having failed prior conservative management. Median operative time was 270 minutes with median length of stay of 5 days. At last follow-up, 11 (91.7%) of patients had complete resolution of their urinary fistula at median follow-up of 29 months. No patients developed osteonecrosis of the bone or complications from their urinary diversion at last follow-up. CONCLUSION: Definitive surgical treatment with holmium laser debridement of the pubic symphysis with concomitant robot-assisted cystectomy and urinary diversion is a safe and durable approach to the complex problem of urinary fistula with pubic symphysis osteomyelitis.

Two-Stage Debridement With Prosthesis Retention for Acute Periprosthetic Joint Infections.

BACKGROUND: Historically, infection control rates with debridement and component retention have been poor in the management of acute prosthetic joint infections. We previously described a 2-stage debridement with prosthesis retention protocol for acute periprosthetic joint infection and reported a 90% success rate in a sample of 20 patients. METHODS: A retrospective review of 83 patients who underwent a 2-stage debridement with implant retention with a minimum 1-year follow-up was performed. Patient data were primarily analyzed to determine infection control rates. Infections were considered controlled when patients had not undergone a reoperation for infection, and demonstrated lack of any clinical signs or symptoms of infection (a well healed wound, diminishing swelling and warmth, absence of erythema, improvement in baseline pain symptoms) A secondary goal of this study was to examine the effects of symptom duration on infection control rate. RESULTS: Average patient follow-up was 41.8 months (range 12-171) for all patients. The overall protocol success rate was 86.7% (72/83): 82.9% in hips and 89.6% in knees. Additionally, protocol success was observed in 45 of 48 primary joints (93.8%) and 27 of 35 (77.1%) revision joints (P = .046). Average time from onset of symptoms to surgery was 6.2 days for successfully treated patients (range 0-27 days) compared to 10.7 days for those who failed treatment (range 1-28 days, P = .070). CONCLUSION: This 2-stage retention protocol resulted in a higher likelihood of infection control compared to prior reports of single stage debridement and modular part exchange.

The Alpha-Defensin Test for Diagnosing Periprosthetic Joint Infection in the Setting of an Adverse Local Tissue Reaction Secondary to a Failed Metal-on-Metal Bearing or Corrosion at the Head-Neck Junction.

BACKGROUND: In patients with adverse local tissue reaction (ALTR) secondary to a failed metal-on-metal (MoM) bearing or corrosion at the head-neck junction in a metal-on-polyethylene bearing, ruling in or out periprosthetic joint infection (PJI) can be challenging. Alpha-defensin has emerged as an accurate test for PJI. The purpose of this multicenter, retrospective study was to evaluate the accuracy of the alpha-defensin synovial fluid test in detecting PJI in patients with ALTR. METHODS: We reviewed medical records of 26 patients from 3 centers with ALTR that had an alpha-defensin test performed. Patients were assessed for PJI using the Musculoskeletal Infection Society criteria. Thirteen of these subjects had MoM total hip arthroplasty, 9 had ALTR secondary to head-neck corrosion, and 4 had MoM hip resurfacing. RESULTS: Only 1 of the 26 patients met Musculoskeletal Infection Society criteria for infection. However, 9 hips were alpha-defensin positive, including 1 true positive and 8 that were falsely positive (31%). All 8 of the false positives were also Synovasure positive, although 5 of 8 had an accompanying warning stating the results may be falsely positive due to a low synovial C-reactive protein value. CONCLUSION: Similar to synovial fluid white blood cell count, alpha-defensin testing is prone to false-positive results in the setting of ALTR. Therefore, we recommend an aggressive approach to ruling out PJI including routine aspiration of all hips with ALTR before revision surgery to integrate the synovial fluid blood cell count, differential, cultures and adjunctive tests like alpha-defensin to allow for accurate diagnosis preoperatively.

Surgeon Personal Protection: An Underappreciated Benefit of Positive-pressure Exhaust Suits.

BACKGROUND: Positive-pressure exhaust suits cost more than standard surgical gowns, and recent evidence suggests that they do not decrease infection risk. As a result, some hospitals and surgeons have abandoned positive-pressure exhaust suits in favor of less expensive alternatives. We propose that in addition to their original purpose of decreasing infection rates, positive-pressure exhaust suits may also improve personal protection for the surgeon and assistants, perhaps justifying their added costs. QUESTIONS/PURPOSES: (1) Do positive-pressure exhaust suits decrease exposure to particulate matter during TKA? (2) What areas covered by gowning systems are at risk of exposure to particulate matter? METHODS: Three surgical gowning systems were tested: (1) surgical gown, face mask, surgical skull cap, protective eyewear; (2) surgical gown, face mask, surgical protective hood, protective eyewear; and (3) positive-pressure exhaust suit. For each procedure, a cadaver knee was injected intraarticularly and intraosseously with a 5-µm fluorescent powder mixed with water (1 g/10 mL). After gowning in the standard sterile fashion, the primary surgeon and two assistants performed two TKAs with each gowning system for a total of six TKAs. After each procedure, three independent observers graded skin exposure of each surgical participant under ultraviolet light using a standardized scale from 0 (no exposure) to 4 (gross exposure). Statistical analysis was performed using Friedman's and Nemenyi tests. The interrater reliability for the independent observers was also calculated. RESULTS: The positive-pressure exhaust suits had less surgeon and assistant exposure compared with other systems (p < 0.001). The median overall exposure grade for each gowning system was 4 for System 1 (range, 3-4), 2.5 for System 2 (range, 2-3), and 0 for System 3 (range, 0-0). In pairwise comparisons between gowning systems, the positive-pressure exhaust suits had less exposure than gowning System 1 (difference of medians: 4, p < 0.001) and gowning System 2 (difference of medians: 2.5, p = 0.038). There was no difference found in exposure between Systems 1 and 2 (difference of medians: 1.5, p = 0.330). When gowning Systems 1 and 2 were removed, particulate matter was found in places that were covered such as the surgeon's beard, lips, inside the nostrils, behind the protective eyewear around the surgeon's eye, and in both eyebrows and eyelashes. CONCLUSIONS: The positive-pressure exhaust suits provided greater personal protection with each procedure than the other two gowning systems. CLINICAL RELEVANCE: With conventional gowns, particulate matter was found in the surgeon's eyelashes, under the face mask around the mouth, and inside the nostrils. Despite recent evidence that certain types of positive-pressure exhaust suits may not decrease infection, there is a clear benefit of surgeon protection from potentially infectious and harmful patient substances. Despite their added costs, hospitals and surgeons should weigh this protective benefit when considering the use of positive-pressure exhaust suits.

Compressive osseointegration endoprosthesis for massive bone loss in the upper extremity: surgical technique.

BACKGROUND: Reconstruction of large segments of bone loss can be very difficult. The use of a prestressed ingrowth implant can offer an attractive surgical option in these challenging cases. METHODS: This report describes the surgical technique in depth, combining the experience of the authors. Nuances of the technique are emphasized. RESULTS: Although published reports are uncommon, long-term restoration of extremity function is possible with this technology. CONCLUSIONS: The use of compressive osseointegration endoprostheses is not yet widespread in the upper extremity, but this technology adds to the host of surgical options for managing massive bone loss and difficult revision surgery.

Use of Compressive Osseointegration Endoprostheses for Massive Bone Loss From Tumor and Failed Arthroplasty: A Viable Option in the Upper Extremity.

BACKGROUND: Endoprostheses using principles of compressive osseointegration have shown good survivorship in several studies involving the lower extremity; however, no series to our knowledge have documented the use of this technology in the management of massive bone loss in the upper limb. QUESTIONS/PURPOSES: (1) What proportion of upper extremity implants using compressive osseointegration fixation principles achieved durable short-term fixation, and what were the modes of failure? (2) What surgical complications resulted from reconstruction using this technique? METHODS: A multiinstitutional retrospective review identified nine patients (five women; four men) who underwent 13 endoprosthetic replacements between 2003 and 2014 using compressive osseointegration (Compliant® Pre-stress Device [CPS]; Biomet Inc, Warsaw, IN, USA) in the upper extremity, including two proximal humeri, two humeral diaphyses, seven distal humeri, and two proximal ulna. During the early part of that period, the indication for use of a compressive prosthesis in our centers was revision of a previous tumor reconstruction (allograft-prosthetic composite or stemmed endoprosthetic reconstruction) (three patients; five implants), or revision arthroplasty with massive bone loss (three patients, four implants); more recently, indications became somewhat more permissive and included posttraumatic bone loss (one patient, one implant), primary bone sarcoma, and resections with very short remaining end segments after diaphyseal resections (two patients, three implants). Minimum followup was 24 months; one patient (one implant) was lost to followup before that time with the implant intact at 14 months and no patients have died. The mean age of the patients was 45 years (range, 21-62 years). Mean followup was 68 months (range, 24-141 months). Implant revision for any cause and for failure of the CPS mechanism was recorded. Modes of failure were categorized as soft tissue, aseptic loosening, structural, infection, and tumor progression; CPS modes of failure were defined as lack of fixation, with or without bone or implant fracture. RESULTS: Of the 12 implants accounted for beyond 2 years, six had undergone revision of any kind. Only two revisions in two patients were attributable to lack of CPS fixation at the bone-implant interface; one of the patients also had periprosthetic and implant fracture develop through the traction bar. Other modes of failure were aseptic loosening of the standard ulnar component (two patients, two implants), bushing wear (one patient; one implant) and infection resulting in two-stage exchange and free soft tissue transfer with retention of the CPS spindle (one patient, one implant). Complications for all nine patients included one transient radial nerve palsy, one ulnar nerve sensory neurapraxia, one superficial infection, and two glenohumeral subluxations, one underwent revision surgery with implantation of a constrained liner. CONCLUSIONS: A compressive osseointegration endoprosthesis is an option for very difficult revisions or sarcoma resection in the upper extremity in which the remaining segment of host bone is too short for a conventional prosthesis. However, surgeons must inform patients that these are salvage operations, and revision surgery is common. Long-term followup of more patients is necessary to further document the survivorship of these implants in the upper extremity. LEVEL OF EVIDENCE: Level IV, therapeutic study.