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Background: Distal femoral replacement (DFR) is a salvage option for complex primary and revision total knee arthroplasty (TKA). Although excellent immediate fixation and weight-bearing are achieved, there is a paucity of data on long-term outcomes of TKA with DFR. The purpose of the present study was to determine implant survivorship, clinical outcomes, and radiographic results of TKAs with contemporary DFR components in a large series. Methods: We identified 144 consecutive TKAs performed with DFR for non-oncologic indications from 2000 to 2015 at a single academic institution. Indications for the index DFR included 66 (46%) for native (n = 11) or periprosthetic (n = 55) femoral fracture, 40 (28%) for staged treatment of periprosthetic joint infection, 28 (19%) for aseptic TKA loosening, and 10 (7%) for other indications. Porous metal cones were used to augment femoral fixation in 28 patients (19%) and tibial fixation in 38 patients (26%). Outcomes included cumulative incidence of revision and reoperation (utilizing a competing risk model), Knee Society scores, and radiographic results. The mean age at the time of index DFR was 72 years, and 65% of patients were female. The mean follow-up was 5 years (range, 2 to 13 years) for the 111 patients who did not undergo revision, had not died, and were not lost to follow-up. Results: The 10-year cumulative incidences of revision for aseptic loosening, all-cause revision, and any reoperation were 17.0%, 27.5%, and 46.3%, respectively. There was an increased risk of reoperation in patients who underwent index DFR for aseptic TKA loosening (hazard ratio [HR], 2.30; p = 0.026) or periprosthetic joint infection (HR, 2.18; p = 0.022) compared with periprosthetic or native femoral fractures. However, there was no difference in risk of revision for aseptic loosening or all-cause revision based on the original operative indication. The mean Knee Society score increased from 45 preoperatively to 71 at the time of the latest follow-up (p < 0.001). Radiographic loosening was observed in 8 unrevised DFRs (7%). There were 7 above-the-knee amputations performed at the time of the final follow-up, all for intractable periprosthetic joint infection. Conclusions: TKAs with contemporary DFR had high 10-year cumulative incidences of both revision and reoperation, underscoring the salvage nature of this procedure as a final reconstructive option. Most patients experienced substantial clinical improvements with this end-stage revision procedure. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Update This article was updated on December 6, 2019, because of a previous error. On page 1936, in Table VII, “Performance of the Bearing Surface Algorithm,” the row that had read “Bearing surface predicted by algorithm” now reads “Bearing surface predicted by algorithm*.” An erratum has been published: J Bone Joint Surg Am. 2020 Jan 2;102(1):e4. Update This article was updated on March 31, 2020, because of a previous error. On page 1934, in Table IV (“THA Bearing Surface-Related Keywords in Operative Notes”), the row that had read “Femoral stem; stem; HFx-stem; femoral component; femoral component/stem; permanent prosthesis; stem fem cemented” now reads “Femoral head; ball; delta head; delta ceramic head; ion treated; BIOLOX delta; ceramic head; ceramic femoral head; ceramic offset head; ceramic (size) head; alumina ceramic head; alumina prosthetic head; alumna ceramic head; BIOLOX ceramic head; BIOLOX delta head; BIOLOX femoral head; BIOLOX delta ceramic head.” An erratum has been published: J Bone Joint Surg Am. 2020 May 6;102(9):e43. Background: Manual chart review is labor-intensive and requires specialized knowledge possessed by highly trained medical professionals. Natural language processing (NLP) tools are distinctive in their ability to extract critical information from raw text in electronic health records (EHRs). As a proof of concept for the potential application of this technology, we examined the ability of NLP to correctly identify common elements described by surgeons in operative notes for total hip arthroplasty (THA). Methods: We evaluated primary THAs that had been performed at a single academic institution from 2000 to 2015. A training sample of operative reports was randomly selected to develop prototype NLP algorithms, and additional operative reports were randomly selected as the test sample. Three separate algorithms were created with rules aimed at capturing (1) the operative approach, (2) the fixation method, and (3) the bearing surface category. The algorithms were applied to operative notes to evaluate the language used by 29 different surgeons at our center and were applied to EHR data from outside facilities to determine external validity. Accuracy statistics were calculated with use of manual chart review as the gold standard. Results: The operative approach algorithm demonstrated an accuracy of 99.2% (95% confidence interval [CI], 97.1% to 99.9%). The fixation technique algorithm demonstrated an accuracy of 90.7% (95% CI, 86.8% to 93.8%). The bearing surface algorithm demonstrated an accuracy of 95.8% (95% CI, 92.7% to 97.8%). Additionally, the NLP algorithms applied to operative reports from other institutions yielded comparable performance, demonstrating external validity. Conclusions: NLP-enabled algorithms are a promising alternative to the current gold standard of manual chart review for identifying common data elements from orthopaedic operative notes. The present study provides a proof of concept for use of NLP techniques in clinical research studies and registry-development endeavors to reliably extract data of interest in an expeditious and cost-effective manner.

Objectives: Participation in National Collegiate Athletic Association (NCAA) football is at an all-time high. This population experiences a substantial injury burden with many of these injuries affecting the upper extremities. The NCAA has adopted a data-driven decision-making process when providing recommendations for protecting player safety. The purpose of this study was to describe the epidemiology of hand and wrist injury in NCAA football in an effort to provide meaningful data for tailoring effective injury prevention strategies. Methods: An epidemiologic study utilizing the NCAA Injury Surveillance Program (NCAA-ISP) database was performed to investigate rates and patterns of hand and wrist injury in NCAA varsity football teams participating in the NCAA-ISP from 2009 to 2014. Descriptive statistics were used to present demographic data. Injury rates were calculated per 1000 athlete-exposures (AEs) using statistical cross-referencing between injury-level and event-level data. Injury mechanism and severity, as measured by time-loss from play, were determined and compared between exposure factors such as player position, player seniority, and practice versus game setting. Results: 725 hand and wrist injuries were captured in 899,225 AEs. The observed practice hand and wrist injury rate was 0.51 injuries per thousand AEs, which was significantly lower than the game injury rate of 3.60 (p < 0.01). Comparing player demographics for injuries sustained during practice as opposed to game time revealed significant differences based on player year, player position, activity performed at the time of injury, and mechanism of injury (p < 0.01, Figure 1). Player-on-player contact was the most common injury mechanism reported with blocking being the most common activity at injury. Of all sustained injuries, 71.4% resulted in no time loss from competition whereas 9.8% of injuries resulted in greater than 7 days of time loss. On average, fracture resulted in the greatest time loss from competition (8.3 ± 24.0 days for injuries sustained in practice setting, 7.7 ±15.8 days for injuries sustained in game setting). When comparing injury by location, hand injury resulted in greater time loss (3.7 ± 15.1, 4.4 ± 13.8) than to nail/subungual (0±0, 0±0), finger (1.6 ± 6.7, 1.1 ± 4.2), and wrist injury (1.2 ± 3.8, 1.8 ± 4.9). Conclusion: This study characterizes the incidence of NCAA football hand and wrist injuries in both practice and game settings and demonstrates the relatively low rate of injuries leading to loss of playing time. Hand and wrist injury was found to be significantly more common in games when compared to practice. Offensive linemen were the most commonly affected players in the cohort, with most injuries occurring during game time compared to practice. This study provides valuable prognostic data regarding expected time loss from play on a per injury pattern basis. Further investigation on specific injury subtypes and expected time loss as a result of these injures would provide trainers, players, and coaches with useful information on an expected post-injury recovery and rehabilitation timeline. [Figure: see text]

Aims The aims of this study were to characterize antibiotic choices for perioperative total knee arthroplasty (TKA) and total hip arthroplasty (THA) prophylaxis, assess antibiotic allergy testing efficacy, and determine rates of prosthetic joint infection (PJI) based on perioperative antibiotic regimen. Patients and Methods We evaluated all patients undergoing primary TKA or THA at a single academic institution between January 2004 and May 2017, yielding 29 695 arthroplasties (22 705 patients), with 3411 arthroplasties in 2576 patients (11.5%) having undergone preoperative allergy testing. A series of institutional databases were combined to identify allergy consultation outcomes, perioperative antibiotic regimen, and infection-free survivorship until final follow-up. Results Among 2576 allergy-tested patients, 2493 patients (97%) were cleared to use cephalosporins. For the entire cohort, 28 174 arthroplasties (94.9%) received cefazolin and 1521 (5.1%) received non-cefazolin antibiotics. Infection-free survivorship was significantly higher among arthroplasties receiving cefazolin compared with non-cefazolin antibiotics, with 0.06% higher survival free of infection at one month, 0.56% at two months, 0.61% at one year, and 1.19% at ten years (p < 0.001). Overall, the risk of PJI was 32% lower in patients treated with cefazolin after adjusting for the American Society of Anesthesiologists (ASA) classification, joint arthroplasty (TKA or THA), and body mass index (BMI; p < 0.001). The number needed to treat with cefazolin to prevent one PJI was 164 patients at one year and 84 patients at ten years. Therefore, potentially 6098 PJIs could be prevented by one year and 11 905 by ten years in a cohort of 1 000 000 primary TKA and THA patients. Conclusion PJI rates are significantly higher when non-cefazolin antibiotics are used for perioperative TKA and THA prophylaxis, highlighting the positive impact of preoperative antibiotic allergy testing to increase cefazolin usage. Given the low rate of true penicillin allergy positivity, and the readily modifiable risk factor that antibiotic choice provides, we recommend perioperative testing and clearance for all patients presenting with penicillin and cephalosporin allergies. Cite this article: Bone Joint J 2019;101-B(6 Supple B):9–15.

Background: Periacetabular osteotomy (PAO) is the most common treatment for symptomatic acetabular dysplasia, or developmental dysplasia of the hip (DDH), in skeletally mature patients. The purpose of this multicenter cohort study was to delineate the long-term radiographic natural history of the dysplastic hip following PAO. Methods: We evaluated all patients undergoing PAO from 1996 to 2012 at 3 academic institutions in the United States. Inclusion criteria were PAO for DDH with a minimum 5-year radiographic follow-up. Exclusion criteria were PAO for isolated acetabular retroversion, neurogenic dysplasia, Legg-Calvé-Perthes disease, and prior hip surgery including osteotomies and arthroscopy. There were 288 patients, 83% of whom were women; the mean age and body mass index (BMI) were 29 years and 25 kg/m 2 , respectively. The mean clinical and radiographic follow-up was 9.2 years (range, 5.0 to 21.1 years). Every preoperative and postoperative hip radiograph was assessed to determine the degree of osteoarthritis according to the Tönnis classification. Survivorship was analyzed by multistate modeling, enabling assessment of progression through the Tönnis grades rather than just individual transitions as with Kaplan-Meier techniques. Results: At the time of final follow-up, 144 patients (50%) had progressed at least 1 Tönnis grade, with 42 patients (14.6%) undergoing total hip arthroplasty. The mean number of years spent in each Tönnis grade following PAO was 19 for Tönnis grade 1, 8 for Tönnis grade 2, and 4 for Tönnis grade 3. The probability of progression to total hip arthroplasty increased significantly on the basis of a higher initial Tönnis grade (p < 0.001). The most marked difference occurred between Tönnis grade 0 or 1 and Tönnis grade 2; for Tönnis grade 1, the probability of progression to total hip arthroplasty at 5 and 10 years was 2% and 11%, respectively, compared with 23% and 53%, respectively, for Tönnis grade 2. Conclusions: PAO effectively alters the natural history of DDH. Precise radiographic progression based on the Tönnis grade can now be used to ascribe prognosis for the native hip. Importantly, this investigation demonstrates a stark increase in progression to total hip arthroplasty within 10 years of PAO for patients with preoperative Tönnis grade-2 osteoarthritis compared with those with Tönnis grade-0 or 1 osteoarthritis. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Revision total hip arthroplasty (revision THA) occurs for a wide variety of indications and in the United States it is coded under Diagnosis-Related Groups (DRGs) 466, 467, and 468, which do not account for revision etiology, a potentially substantial driver of cost. This study investigates revision THA costs and 30-day complications by indication, both locally and nationally. Methods: Hospitalization costs and complication rates for 1,422 aseptic revision THAs performed at a high-volume center between 2009 and 2014 were retrospectively reviewed. Additionally, charges for 28,133 revision THAs in the National Inpatient Sample (NIS) were converted to costs using the Healthcare Cost and Utilization Project cost-to-charge ratios, and 30-day complication rates for 3,224 revision THAs were obtained with use of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). Costs and complications were compared between revision THAs performed for fracture, wear/loosening, and dislocation/instability with use of simultaneous and pairwise comparisons and a multivariable model accounting for American Society of Anesthesiologists (ASA) score, age, and sex. Results: Local hospitalization costs for fracture (median, $25,672) were significantly higher than those for wear/loosening ($20,228; p < 0.001) or dislocation/instability ($17,911; p < 0.001), with differences remaining significant even after adjusting for patient comorbidities (p < 0.001). NIS costs for fracture (median, $27,596) were higher than those for other aseptic indications (wear/loosening: $21,176, p < 0.001; dislocation/instability: $16,891, p< 0.001). Local 30-day orthopaedic complication rates for fracture (20.7%) were higher those than for dislocation/instability (9.0%; p = 0.007) and similar to those for wear/loosening (17.6%; p = 0.434). Nationally, combined medical and surgical complication rates for fracture (71.3% of patients with ≥1 complication) were significantly higher than those for wear/loosening (35.2%; p < 0.001) or dislocation/instability (35.1%; p < 0.001). Conclusions: Hospitalization costs for revision THA for fracture were 33% to 48% higher than for all other aseptic revision THAs, both locally and nationally. This increased cost persisted even after multivariable comorbidity adjustment, the current DRG basis for stratifying revision THA reimbursement. Additionally, 30-day complication rates suggest that increased resource utilization for fracture patients continues even after discharge. Indication-specific coding and reimbursement systems are necessary to maintain sustainable access to revision THA for all patients. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Hypertrophic scars and keloids are characterized by excessive fibrosis and can be functionally problematic. Indeed, hypertrophic scarring is characterized by wide, raised scars that remain within the original borders of injury and have a rapid growth phase. There is a need for quantitative scar measurement modalities to effectively evaluate and monitor treatments. We aim to assess the role of the non-invasive scar-measuring device, ultrasound surface wave elastography (USWE), in accurately evaluating scar metrics. Two sites of breast tissue were tested control and scar portions. In USWE, a small, local, and 0.1-s harmonic vibration at three excitation frequencies (100, 150, and 200 Hz) was generated on these sites, and the resulting surface wave speed was measured via an ultrasound probe with a central frequency of 6.4 MHz. There was a statistically significant difference in the wave speed at three frequencies of the scar portion between prior and after treatment, suggesting that the scar portion was softener after treatment. USWE provides an objective assessment of the reaction of the scar to injury and treatment response.

Background: Participation in National Collegiate Athletic Association (NCAA) football is at an all-time high. This population of athletes experiences a substantial injury burden, with many injuries affecting the upper extremities. Purpose/Hypothesis: The purpose of this study was to describe the epidemiology of hand and wrist injuries in college football players from the academic years 2009–2010 to 2013–2014. We hypothesized that variables such as event type (practice vs game), mechanism of injury, and player position would have an effect on the injury incidence. Study Design: Descriptive epidemiological study. Methods: An epidemiological study utilizing the NCAA Injury Surveillance Program was performed to investigate rates and patterns of hand and wrist injuries in participating varsity football teams from 2009–2010 to 2013–2014. Results: A total of 725 hand and wrist injuries were captured in 899,225 athlete-exposures. The observed practice injury rate was 0.51 injuries per 1000 athlete-exposures, compared with a game injury rate of 3.60 ( P < .01). Player-on-player contact was the most common injury mechanism reported, with blocking being the most common activity at the time of injury. Offensive linemen were most likely to experience an injury. Of all injuries sustained, 71.4% resulted in no time loss from competition, whereas 9.8% of injuries resulted in longer than 7 days of time loss. A fracture resulted in the greatest time loss from competition (mean ± SD, 8.3 ± 24.0 days; median, 0 days [range, 0-148 days] for injuries sustained in a practice setting) (mean ± SD, 7.7 ± 15.8 days; median, 0 days [range, 0-87 days] for injuries sustained in a game setting). Conclusion: Hand and wrist injuries were found to be significantly more common in games when compared with practices. This study provides valuable prognostic data regarding expected time loss on a per-injury pattern basis. Further investigation on specific injury subtypes and expected time loss as a result of these injures would provide trainers, players, and coaches with useful information on an expected postinjury recovery and rehabilitation timeline.

Introduction: There is little data regarding timing of index dislocation in patients who undergo primary total hip arthroplasty (THA) and subsequent risk of redislocation and revision. Methods: Between 1992 and 2013, 21,490 primary THAs were performed at a single institution. 189 patients (190 hips) had a first episode of dislocation within one year of index surgery (0.9 %). 32 patients (32 hips) were excluded for the following reasons: complex THA secondary to fracture malunion, Crowe III/IV developmental hip dysplasia, periprosthetic fracture, prior hip surgery, incomplete information, and hip abductor avulsion. The final cohort consisted of 157 patients (158 hips) who experienced dislocation within 1 year of primary non-complex THA. 88 patients were female (56%), mean age was 61 years (SD = 14), and mean follow-up was 76 months (range 0–229). Multivariable Cox proportional-hazards regression models with fractional polynomial models were used to estimate the association between timing of index dislocation and subsequent redislocation and revision surgery. Results: 69 patients (44%) redislocated at final follow-up. Revision for any cause occurred in 26 out of 157 hips (17%). Time lapse from index THA to first dislocation was significantly associated with the risk of redislocation ( p = 0.004) and with the risk of revision ( p = 0.04). For every additional 7 days from surgery, risk of redislocation increased by a factor of 1.1 and risk of revision was increased by a factor of 1.13. Conclusion: This study demonstrates there is a lower risk of redislocation and revision in patients who have a first episode of dislocation closer to primary THA.