Biomechanical evaluation of the modified lasso technique.

BACKGROUND: The Terrible Triad of the elbow is a constellation of elbow dislocation, radial head fracture and coronoid process fracture. A common type of coronoid fracture documented with this triad is type II Regan-Morrey coronoid fractures. The preferred fixation method for this fracture type is the lasso technique, medial-lateral tunnel orientation being the traditional approach. Considering elbow anatomy, we saw an opportunity to potentially improve fixation by altering the suture lasso tunnel orientation to a proximal-distal orientation. HYPOTHESIS: Two tunnels in the proximal-distal direction would result in greater biomechanical stability as compared to the traditional lasso technique. MATERIAL AND METHODS: A type 2 Regan-Morrey fracture was created in 12 fresh frozen cadaveric elbows at 50% of the coronoid height using an oscillating saw. The humero-ulnar joint was placed in 0 degrees flexion then loaded at a rate of 10mm/min to failure. RESULTS: The control technique (medio-lateral tunnels) showed failure load of 150±81N that was not significantly different (p=0.825) than the 134±116N measured for the modified technique (distal-proximal tunnels). The portion of the load-displacement curve used to calculate stiffness was linear (R^2=0.94±0.04) with determination coefficients that did not differ between the two groups (p=0.351). For stiffness, we measured 17±13N/mm and 14±12N/mm respectively for control and modified techniques that did not result in a significant difference (p=0.674). CONCLUSION: In this attempt to improve the shortcomings of the lasso technique, we found that changing from medio-lateral to proximal-distal drilling directions did not result in an appreciable biomechanical benefit. LEVEL OF EVIDENCE: Basic science study; Biomechanics.

Modular fluted tapered stems in two-stage reimplantation of previously infected total hip arthroplasties.

Aims: Uncemented implants are now commonly used at reimplantation of a two-stage revision total hip arthoplasty (THA) following periprosthetic joint infection (PJI). However, there is a paucity of data on the performance of the most commonly used uncemented femoral implants - modular fluted tapered (MFT) femoral components - in this setting. This study evaluated implant survival, radiological results, and clinical outcomes in a large cohort of reimplantation THAs using MFT components. Methods: We identified 236 reimplantation THAs from a single tertiary care academic institution from September 2000 to September 2020. Two designs of MFT femoral components were used as part of an established two-stage exchange protocol for the treatment of PJI. Mean age at reimplantation was 65 years (SD 11), mean BMI was 32 kg/m2 (SD 7), and 46% (n = 109) were female. Mean follow-up was seven years (SD 4). A competing risk model accounting for death was used. Results: The 15-year cumulative incidence of any revision was 24%. There were 48 revisions, with the most common reasons being dislocation (n = 25) and infection (n = 16). The 15-year cumulative incidence of any reoperation was 28%. Only 13 revisions involved the fluted tapered component (FTC), for a 15-year cumulative incidence of any FTC revision of 8%. Only two FTCs were revised for aseptic loosening, resulting in a 15-year cumulative incidence of FTC revision for aseptic loosening of 1%. Stem subsidence ≥ 5 mm occurred in 2% of unrevised cases. All stems were radiologically stable at most recent follow-up. Mean Harris Hip Score was 69 (SD 20) at most recent follow-up. Conclusion: This series demonstrated that MFT components were durable and reliable in the setting of two-stage reimplantation THA for infection. While the incidence of aseptic loosening was very low, the incidence of any revision was 24% at 15 years, primarily due to dislocation and recurrent PJI.

Highly Porous Acetabular Cup and Augment Constructs in Complex Revision Total Hip Arthroplasty: What Predicts 10-Year Implant Survivorship?

BACKGROUND: Porous tantalum acetabular cup and augment constructs have demonstrated favorable outcomes up to 5 years postsurgery despite severe bone loss during revision total hip arthroplasty (THA). Prior literature lacks long-term studies with substantial case numbers. This study aims to assess long-term clinical and radiographic outcomes 10 years postsurgery in patients undergoing revision THA with porous tantalum acetabular cup-augment constructs and determine factors associated with long-term survivorship. METHODS: Between 2000 and 2012, 157 revision THAs were performed in cases with major acetabular defects (mainly Paprosky type IIIA and IIIB) utilizing porous tantalum cup-augment constructs. Pelvic discontinuity was noted intraoperatively in 17 hips (11%). Postoperative radiographs were evaluated at regular intervals for implant stability and radiolucent lines. There were 49 patients who had complete radiographic follow-up at 10 years or longer postsurgery. RESULTS: The 10-year survivorship free of revision of the cup-augment construct for aseptic loosening was 93%, free of any acetabular construct revision was 91%, free of any hip rerevision was 77%, and free of any reoperation was 75%. Pelvic discontinuity was associated with increased risk of reoperation (hazard ratio [HR] = 2.8), any hip rerevision (HR = 3.2), any cup-augment construct revision (HR = 11.8), and aseptic construct revision (HR = 10.0). Of unrevised cases with radiographs at 10 years, 4 hips showed radiographic loosening. Mean Harris hip scores improved from 47 preoperatively to 79 at 10 years. CONCLUSIONS: Porous tantalum acetabular cup-augment constructs used in revision THA with severe acetabular bone loss provide excellent implant survivorship at 10 years when the acetabulum is intact. Due to lower survivorship of cup-augment constructs in cases of pelvic discontinuity, additional construct fixation or stabilization methods are recommended, when a discontinuity is present. LEVEL OF EVIDENCE: IV.

Are luggage scales a viable alternative to hand-held dynamometers for the measurement of shoulder scaption strength?

Background: The accurate and reliable measurement of muscle strength is a valuable tool in most medical practices. The use of dynamometers allows for objective muscle strength assessment. Even so, dynamometry has its limitations due to increased cost and inconvenience in the clinic. Isokinetic dynamometers, the gold standard, are typically very large and expensive. However, smaller hand-held dynamometers are a cheaper and more efficient alternative. Hand-held dynamometers have been shown to demonstrate comparable reliability to the more expensive isokinetic dynamometers, despite their reduced cost and ease of use. Even though hand-held dynamometers are cheaper and more convenient to use in the clinical setting, their price tag is still burdensome for most medical practices, commonly costing $1000 or more. The aim of this study is to assess the reliability of luggage scales vs. dynamometers for measuring shoulder scaption strength. Methods: One hand-held dynamometer was compared to two luggage scales using a set-up intended to mimic clinical testing. The set-up consisted of each device being tethered to the floor with the opposite end tied to a length of paracord that had been placed through a shoulder-height pulley and fastened to a flat plate used to hold the weight. In total, ten trials were completed, where a 2.3 kg (5 lb), 4.5 kg (10 lb), and 11.3 kg (25 lb). weight was measured by each device. Analysis of variance was used to compare the numerical data for the three groups. Results: Our results indicate that there were no significant differences in the force measurements between each device (P = .99). The average force measurements between the three dynamometers were: 2.3 kg trial: 2.3 kg, 2.4 kg, and 2.2 kg; 4.5 kg trial: 4.5 kg, 4.6 kg, and 4.5 kg ; and 11.3 kg trial: 11.4 kg, 11.3 kg, and 11.4 kg. for the digital dynamometer, digital luggage scale, and the analog luggage scale, respectively. Subgroup analysis showed there was also no difference in force measurements between the 3 devices for the 2.3 kg, 4.5 kg, and 11.3 kg. trials (P = .14, P = .49, and P = .40, respectively). Conclusion: Our data demonstrates that two inexpensive luggage scales showed no statistically significant differences in measurements compared to an expensive hand-held dynamometer. Utilization of luggage scales to measure shoulder scaption strength should yield similar results to handheld dynamometers. This may be an alternative, objective measure of manual muscle strength that is both efficient and economical.

Marlex Mesh Reconstruction of the Extensor Mechanism: A Concise 5-Year Follow-up of 2 Previous Reports.

LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Machine-Learning Identifies a Strategy for Differentiation Therapy in Solid Tumors.

BACKGROUND: Although differentiation therapy can cure some hematologic malignancies, its curative potential remains unrealized in solid tumors. This is because conventional computational approaches succumb to the thunderous noise of inter-/intratumoral heterogeneity. Using colorectal cancers (CRCs) as an example, here we outline a machine learning(ML)-based approach to track, differentiate, and selectively target cancer stem cells (CSCs). METHODS: A transcriptomic network was built and validated using healthy colon and CRC tissues in diverse gene expression datasets (~5,000 human and >300 mouse samples). Therapeutic targets and perturbation strategies were prioritized using ML, with the goal of reinstating the expression of a transcriptional identifier of the differentiated colonocyte, CDX2, whose loss in poorly differentiated (CSC-enriched) CRCs doubles the risk of relapse/death. The top candidate target was then engaged with a clinical-grade drug and tested on 3 models: CRC lines in vitro, xenografts in mice, and in a prospective cohort of healthy (n = 3) and CRC (n = 23) patient-derived organoids (PDOs). RESULTS: The drug shifts the network predictably, induces CDX2 and crypt differentiation, and shows cytotoxicity in all 3 models, with a high degree of selectivity towards all CDX2-negative cell lines, xenotransplants, and PDOs. The potential for effective pairing of therapeutic efficacy (IC50) and biomarker (CDX2-low state) is confirmed in PDOs using multivariate analyses. A 50-gene signature of therapeutic response is derived and tested on 9 independent cohorts (~1700 CRCs), revealing the impact of CDX2-reinstatement therapy could translate into a ~50% reduction in the risk of mortality/recurrence. CONCLUSIONS: Findings not only validate the precision of the ML approach in targeting CSCs, and objectively assess its impact on clinical outcome, but also exemplify the use of ML in yielding clinical directive information for enhancing personalized medicine.

Contemporary outcomes of primary total hip arthroplasty in patients with inflammatory arthritis.

Aims: Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis. Methods: We identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m2 (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18). Results: The ten-year cumulative incidence of any revision was 3%, and was highest in psoriatic arthritis patients (16%). The most common indications for the 15 revisions were dislocations (n = 8) and periprosthetic joint infections (PJI; n = 4, all on disease-modifying antirheumatic drugs (DMARDs)). The ten-year cumulative incidence of reoperation was 6.1%, with the most common indications being wound infections (six cases, four on DMARDs) and postoperative periprosthetic femur fractures (two cases, both uncemented femoral components). The ten-year cumulative incidence of complications not requiring reoperation was 13.1%, with the most common being intraoperative periprosthetic femur fracture (15 cases, 14 uncemented femoral components; p = 0.13). Radiological evidence of early femoral component subsidence was observed in six cases (all uncemented). Only one femoral component ultimately developed aseptic loosening. Harris Hip Scores substantially improved (p < 0.001). Conclusion: Contemporary primary THAs with HXLPE in patients with inflammatory arthritis had excellent survivorship and good functional outcomes regardless of fixation method. Dislocation, PJI, and periprosthetic fracture were the most common complications in this cohort with inflammatory arthritis.

Sex-specific analysis of clinical features and outcomes in staphylococcal periprosthetic joint infections managed with two-stage exchange arthroplasty.

Background: Differences in susceptibility and response to infection between males and females are well established. Despite this, sex-specific analyses are under-reported in the medical literature, and there is a paucity of literature looking at differences between male and female patients with periprosthetic joint infection (PJI). Whether there are sex-specific differences in presentation, treatment tolerability, and outcomes in PJI has not been widely evaluated. Methods: We undertook a retrospective case-matched analysis of patients with staphylococcal PJI managed with two-stage exchange arthroplasty. To control for differences other than sex which may influence outcome or presentation, males and females were matched for age group, causative organism category (coagulase-negative staphylococci vs. Staphylococcus aureus), and joint involved (hip vs. knee). Results: We identified 156 patients in 78 pairs of males and females who were successfully matched. There were no significant baseline differences by sex, except for greater use of chronic immunosuppression among females (16.4 % vs. 4.1 %; p = 0.012 ). We did not detect any statistically significant differences in outcomes between the two groups. Among the 156 matched patients, 16 recurrent infections occurred during a median follow-up time of 2.9 (IQR 1.5-5.3) years. The 3-year cumulative incidence of relapse was 16.1 % for females, compared with 8.8 % for males ( p = 0.434 ). Conclusions: Success rates for PJI treated with two-stage exchange arthroplasty are high, consistent with previously reported literature. This retrospective case-matched study did not detect a significant difference in outcome between males and females with staphylococcal PJI who underwent two-stage exchange arthroplasty.

Comparative Survival of Contemporary Cementless Acetabular Components Following Revision Total Hip Arthroplasty.

BACKGROUND: The advent of highly porous ingrowth surfaces and highly crosslinked polyethylene has been expected to improve implant survivorship in revision total hip arthroplasty. Therefore, we sought to evaluate the survival of several contemporary acetabular designs following revision total hip arthroplasty. METHODS: Acetabular revisions performed from 2000 to 2019 were identified from our institutional total joint registry. We studied 3,348 revision hips, implanted with 1 of 7 cementless acetabular designs. These were paired with highly crosslinked polyethylene or dual-mobility liners. A historical series of 258 Harris-Galante-1 components, paired with conventional polyethylene, was used as reference. Survivorship analyses were performed. For the 2,976 hips with minimum 2-year follow-up, the median follow-up was 8 years (range, 2 to 35 years). RESULTS: Contemporary components with adequate follow-up had survivorship free of acetabular rerevision of ≥95% at 10-year follow-up. Relative to Harris-Galante-1 components, 10-year survivorship free of all-cause acetabular cup rerevision was significantly higher in Zimmer Trabecular Metarevision (hazard ratio (HR) 0.3, 95% confidence interval (CI) 0.2-0.45), Zimmer Trabecular MetaModular (HR 0.34, 95% CI 0.13-0.89), Zimmer Trilogy (HR 0.4, 95% CI 0.24-0.69), DePuy Pinnacle Porocoat (HR 0.24, 95% CI 0.11-0.51), and Stryker Tritanium revision (HR 0.46, 95% CI 0.24-0.91) shells. Among contemporary components, there were only 23 rerevisions for acetabular aseptic loosening and no rerevisions for polyethylene wear. CONCLUSION: Contemporary acetabular ingrowth and bearing surfaces were associated with no rerevisions for wear and aseptic loosening was uncommon, particularly with highly porous designs. Therefore, it appears that contemporary revision acetabular components have dramatically improved upon historical results at available follow-up.

A Living Organoid Biobank of Crohn's Disease Patients Reveals Molecular Subtypes for Personalized Therapeutics.

Crohn's disease (CD) is a complex, clinically heterogeneous disease of multifactorial origin; there is no perfect pre-clinical model, little insight into the basis for such heterogeneity, and still no cure. To address these unmet needs, we sought to explore the translational potential of adult stem cell-derived organoids that not only retain their tissue identity, but also their genetic and epigenetic disease-driving traits. We prospectively created a biobank of CD patient-derived organoid cultures (PDOs) using biopsied tissues from colons of 34 consecutive subjects representing all clinical subtypes (Montreal Classification B1-B3 and perianal disease). PDOs were generated also from healthy subjects. Comparative gene expression analyses enabled benchmarking of PDOs as tools for modeling the colonic epithelium in active disease and revealed that despite the clinical heterogeneity there are two major molecular subtypes: immune-deficient infectious-CD [IDICD] and stress and senescence-induced fibrostenotic-CD [S2FCD]. The transcriptome, genome and phenome show a surprising degree of internal consistency within each molecular subtype. The spectrum of morphometric, phenotypic, and functional changes within the "living biobank" reveals distinct differences between the molecular subtypes. These insights enabled drug screens that reversed subtype-specific phenotypes, e.g., impaired microbial clearance in IDICD was reversed using agonists for nuclear receptors, and senescence in S2FCD was rectified using senotherapeutics, but not vice versa . Phenotyped-genotyped CD-PDOs may fill the gap between basic biology and patient trials by enabling pre-clinical Phase '0' human trials for personalized therapeutics. In Brief: This work creates a prospectively biobanked phenotyped-genotyped Crohn's disease patient-derived organoids (CD-PDOs) as platforms for molecular subtyping of disease and for ushering personalized therapeutics. HIGHLIGHTS: Prospectively biobanked CD-organoids recapitulate the disease epithelium in patientsThe phenome-transcriptome-genome of CD-organoids converge on two molecular subtypesOne subtype shows impaired microbial clearance, another increased cellular senescencePhenotyped-genotyped PDOs are then used for integrative and personalized therapeutics.

Extended Trochanteric Osteotomy in Revision Total Hip Arthroplasty.

Background: Removal of well-fixed femoral components during revision total hip arthroplasty (THA) can be difficult and time-consuming1, leading to numerous complications, such as femoral perforation, bone loss, and fracture. Extended trochanteric osteotomies (ETOs), which provide wide exposure and direct access to the femoral canal under controlled conditions, have become a popular method to circumvent these challenges. ETOs were popularized by Wagner (i.e., the anterior-based osteotomy), and later modified by Paprosky (i.e., the lateral-based osteotomy)2. Description: The decision to utilize the laterally based Paprosky ETO versus the anteriorly based Wagner ETO is primarily based on surgeon preference, the location and type of in situ implants, and the osseous anatomy. Typically, a laterally based ETO is most facile in conjunction with a posterior approach and an anteriorly based ETO is most commonly paired with a lateral or anterolateral approach. Attention must be paid to maintaining vascularity to the osteotomy fragment, including minimizing stripping of the vastus lateralis from the osteotomy fragment and maintaining abductor attachments to the osteotomy fragment. When utilizing a laterally based ETO, the posterior border of the vastus lateralis must be carefully elevated to provide exposure for performance of the osteotomy. When an anteriorly based osteotomy is performed, the surgeon may instead extend the abductor tenotomy proximally with use of a longitudinal split of the vastus lateralis distally, which helps to keep the anterior and posterior sleeves of soft tissue in continuity. In either approach, dissection of the vastus lateralis involves managing several large vascular perforators. We prefer performing careful blunt dissection to identify the perforators and prophylactically controlling them, with ligation of large vessels and electrocautery of smaller vessels. Vascular clips are also available in case difficult-to-control bleeding is encountered. In general, an oscillating saw (with preference for a thin blade) is utilized to complete the posterior longitudinal limb of the ETO, extending approximately 12 to 16 cm distally from the tip of the greater trochanter. Although a 12 to 16-cm zone is required to maintain maximum vascularity to the osteotomized fragment, the osteotomy length must ultimately be determined by (1) the length of the femoral component to be removed; (2) the presence of distal bone ingrowth, ongrowth, or cement; and (3) the presence of distal hardware or stemmed knee components. A smaller oscillating saw is then utilized to complete the transverse limb at the previously identified distal extent. A high-speed pencil-tip burr is utilized to complete the corners of the osteotomy in a rounded configuration, and a combination of saws and pencil-tip burrs is utilized to create partial proximal and distal anterior longitudinal limbs of the osteotomy to the extent allowed by the soft-tissue attachments. The anterior longitudinal limb may be further weakened in a controlled fashion with use of serial drill holes. The anterior longitudinal limb then undergoes controlled fracture by placement of 2 to 4 broad straight osteotomes in the posterior longitudinal limb. These osteotomes are carefully levered anteriorly in unison with a gentle, steady force. After the ETO is completed, intramedullary prostheses, hardware, and cement are removed; the acetabulum is addressed as needed; and a final femoral stem is implanted, if appropriate. After completion of the osteotomy, the osteotomized fragment must be retracted gently, with care taken to avoid a fracture and maintain vascularity. To this end, debridement of the endosteum of the osteotomized fragment, including any cement removal, should be avoided until the end of the procedure, when the osteotomy is ready to be closed. Our preferred method for closure is to place 1 prophylactic cable 1 cm distal to the osteotomy, 1 to 2 cables along the diaphyseal segment of the osteotomy, and 1 Luque wire above the less trochanter. A Luque wire is our specific choice for the location above the lesser trochanter because it sits in the effective joint space; however, the use of Luque wires distal to the lesser trochanter is also acceptable. A strut allograft or locking plate can be utilized to reinforce the osteotomy in rare cases or to bridge interprosthetic stress risers. Trochanteric implants are typically avoided because of the low rate of clinically relevant trochanteric migration with this closure technique and because of the high rate of symptomatic implants with trochanteric claws or plates. Alternatives: An alternative osteotomy of similar exposure is the transfemoral osteotomy. Additionally, a variety of non-extended trochanteric osteotomies, such as trochanteric slide osteotomies, offer more limited exposure. Rationale: Femoral surgical exposure for revision THA can be aided by performing transfemoral osteotomies, but these provide less precise control of the separate proximal femoral osteotomized segment(s), and healing and fixation can be less reliable. Less invasive osteotomies such as non-extended trochanteric osteotomies typically do not provide adequate exposure in challenging cases for which ETO is being considered. Expected Outcomes: ETOs have high union rates, and notable trochanteric migration is infrequent. The most common complications are fracture of the osteotomy fragment intraoperatively or postoperatively. Radiographic and clinical union is achieved in 98% of patients. The mean proximal trochanteric osteotomy fragment migration prior to union is 3 mm. ETO fragment migration of >1 cm occurs in just 7% of hips. Postoperative greater trochanter fractures occur in 9% of hips. The 10-year survivorship free of revision for aseptic femoral loosening, free of femoral or acetabular component removal or revision for any reason, and free of reoperation for any reason is 97%, 91%, and 82%, respectively3. Important Tips: Attention should be paid to patient anatomy, deformity, surgical approach, and implant type when choosing to perform a laterally based Paprosky or anteriorly based Wagner ETO.Appropriate length of the posterior longitudinal limb of the ETO is approximately 12 to 16 cm distally from the tip of the greater trochanter.Attention must be paid to maintaining vascularity to the osteotomy fragment, including minimizing stripping of the vastus lateralis from the osteotomy fragment and maintaining abductor attachments to the osteotomy fragment.A high-speed pencil-tip burr should be utilized to complete the corners of the osteotomy in a rounded configuration in order to avoid stress risers.The anterior longitudinal limb is completed by controlled fracture of the remaining intervening segment in order to maintain vastus lateralis attachments and vascular supply to the osteotomy fragment.The ETO is closed with use of cerclage cables and/or double-stranded Luque wires, typically utilizing a total of 3 to 4 in order to obtain secure fixation without compromising local biology. Acronyms and Abbreviations: MFT = modular fluted tapered.

Low Mortality of Orthopedic Trauma Patients With Asymptomatic COVID-19: A Level I Trauma Center Pandemic Experience.

Background: Early (2020) reports on mortality in patients with coronavirus disease 2019 (COVID-19) who underwent orthopedic surgery ranged from 20.5% to 56%, but these studies included elderly patients with multiple comorbidities. The mortality rate for younger and asymptomatic COVID-19-positive patients undergoing orthopedic surgery after high-energy trauma is underreported. The purpose of this study was to compare the 30-day mortality of asymptomatic COVID-19-positive patients and COVID-19-negative patients surgically treated for orthopedic trauma at a Level I trauma center during the coronavirus pandemic. A secondary objective was to compare the patients' postoperative hospital course and length of stay. Methods: This study is a single-center retrospective review of all patients who underwent an orthopedic surgical procedure at a Level I trauma center during a 3-month period early in the COVID-19 pandemic. All patients received a preoperative nasopharyngeal swab to determine COVID-19 infection status. Preoperative demographic variables, perioperative and postoperative mortality within 30 days, length of stay, and intensive care unit days were compared between COVID-19-positive and COVID-19-negative patients. Results: Of the 471 total patients, 13 were COVID-19-positive and 458 were COVID-19-negative prior to surgery. The average age of all patients was 40.5 ± 19.8 years. The mortality rate in the COVID-19-positive group was 0% vs 0.7% in the COVID-19-negative group, with no significant difference between groups (P=0.77). The COVID-19-positive group vs the COVID-19-negative group had no significant difference in hospital length of stay (7.4 days vs 4.4 days, respectively, P=0.12). Conclusion: Asymptomatic COVID-19-positive orthopedic trauma patients treated with surgery at a Level I trauma center in a 3-month period during the COVID-19 pandemic had a 0% mortality rate, and we found no differences between COVID-19-positive and COVID-19-negative patients with respect to mortality and hospital length of stay.

Case report: unique failure of a Synthes TFNA fenestrated lag screw in a peritrochanteric nonunion.

Background: Intertrochanteric femur fractures are a common orthopaedic injury that are often treated surgically. Cephalomedullary nails (CMN) are frequently the implant of choice for intertrochanteric femur fractures, resulting in low complication rates. Implant failure is a rare but reported complication. Common locations of failure include the proximal nail aperture, distal screw holes, and implant shaft. In this case report, we describe a CMN failure pattern through fenestrated cephalic screw holes. Case: A 70-year-old female sustained an OTA 31A-2.2 peritrochanteric fracture during a motor vehicle collision. She was treated the following day with a Synthes Trochanteric Fixation Nail-Advanced CMN utilizing a fenestrated cephalic screw. There were no intraoperative complications. She was made non-weight bearing for 8 weeks after the procedure due to ipsilateral foot fractures. At 6 months follow-up she was noted to have a delayed union. 11 months postoperatively she suffered a ground level fall and the cephalic lag screw failed through its fenestrations, resulting in varus collapse of her fracture at the femoral neck. The patient then underwent nail extraction and salvage total hip arthroplasty. Conclusion: Cephalomedullary nail implant failure is presented with implant fracture propagation through a fenestrated cephalic screw. Cephalomedullary lag screw failure is rare and can be difficult to manage. It is important to monitor new implants for unique failure mechanisms.

Improved Radiation Exposure Monitoring of Orthopaedic Residents After Institution of a Personalized Lead Protocol.

Radiation exposure of orthopaedic residents should be accurately monitored to monitor and mitigate risk. The purpose of this study was to determine whether a personalized lead protocol (PLP) with a radiation monitoring officer would improve radiation exposure monitoring of orthopaedic surgery residents. Materials and Methods: This was a retrospective case-control study of 15 orthopaedic surgery residents monitored for radiation exposure during a 2-year period (March 2017 until February 2019). During the first 12-month period (phase 1), residents were given monthly radiation dosimeter badges and instructed to attach them daily to the communal lead aprons hanging outside the operating rooms. During the second 12-month period (phase 2), a PLP (PLP group) was instituted in which residents were given lead aprons embroidered with their individual names. A radiation safety officer was appointed who placed the badges monthly on all lead aprons and collected them at the end of the month, whereas faculty ensured residents wore their personalized lead apron. Data collected included fluoroscopy use time and radiation dosimeter readings during all orthopaedic surgeries in the study period. Results: There were 1,252 orthopaedic surgeries using fluoroscopy during phase 1 in the control group and 1,269 during phase 2 in the PLP group. The total monthly fluoroscopy exposure time for all cases averaged 190 minutes during phase 1 and 169 minutes during phase 2, with no significant difference between the groups (p < 0.45). During phase 1, 73.1% of the dosimeters reported radiation exposure, whereas during phase 2, 88.7% of the dosimeters reported radiation exposure (p < 0.001). During phase 1, the average monthly resident dosimeter exposure reading was 7.26 millirems (mrem) ± 37.07, vs. 19.00 mrem ± 51.16 during phase 2, which was significantly higher (p < 0.036). Conclusions: Institution of a PLP increased the compliance and exposure readings of radiation dosimeter badges for orthopaedic surgery residents, whereas the actual monthly fluoroscopy time did not change. Teaching hospitals should consider implementing a PLP to more accurately monitor exposure. Level of Evidence: 3.

Variability in rod to bone distance needed in pelvic subcutaneous internal fixation to avoid nerve compression: A tridimensional population-based study.

INTRODUCTION: Pelvic internal fixation has become a popular method for treatment of unstable pelvic ring injuries. Although successful, one complication is femoral nerve palsy from compression of the connecting rod. In light of this complication, this study was designed to evaluate sagittal inclinations of the rod and the feasibility of using a rod with a constant curvature. HYPOTHESIS: It is hypothesized that that there is a connection between the sagittal inclination of the rod and the rod to bone distance, as well as single rod can be contoured with a constant curvature to be used in the majority of all patients. METHODS: Three dimensional models of pelvis CTs from a single level 1 trauma center were created and imported into a program where software superimposed a pre-contoured rod in the sagittal planes upon the pelvic slices. The sagittal inclination was deemed acceptable is no interference occurred between the area of compression risk and the rod. For each pelvis and considered sagittal rod inclination, the rod radius of curvature (ROC), minimal rod to bone distance (RTB) and transverse inclinations (φL and φR) were measured at which the pedicle screws should be inserted to follow the direction of the smallest RTB. RESULTS: The sagittal inclinations feasible for all subjects were between 15° to 30°. In this sagittal range, the average RTB varied in values ranging from 4.0±0.9mm to 25.4±11.4mm (p<0.01). Only 46% of subjects allowed a rod with constant curvature. DISCUSSION AND CONCLUSION: Our study found that a rod to bone distance of 15mm was not safe for all models. As well, many subject models did not allow placement of pre-contoured rod. Patient specific templating of pelvic subcutaneous internal fixation is strictly needed to limit complications. LEVEL OF EVIDENCE: VII; Basic Science.

Contemporary Outcomes of Transfemoral Amputation After Total Knee Arthroplasty.

BACKGROUND: Transfemoral amputation (TFA) is a salvage procedure for unreconstructable failed total knee arthroplasty (TKA). Prior studies have reported poor outcomes, patient survival, and prosthetic use. The purpose of this study was to analyze patient outcomes and prosthetic utilization in a contemporary group of patients undergoing TFA in the setting of a TKA. METHODS: We reviewed 112 patients undergoing TFA with a prior TKA. Indications for amputation and postoperative functional measures were captured through chart review. Patients were contacted by survey to assess the quality of life. The mean follow-up after TFA was 4 years. RESULTS: Amputations were performed for a chronically infected TKA (n = 87, 78%) and an ischemic limb without signs of an infected TKA (n = 22, 20%). The 10-year survival after TFA was 21%. Of the patients not lost to follow-up, 53 (47%) patients were fitted for a prosthesis. Patients who underwent a TFA after the year 2000 were more likely to be fit for a prosthesis (odds ratio 7.27, P < .01); however, patients were likely to be ambulatory before TFA than after TFA (odds ratio 3.68, P < .01). After TFA, the mean 12-Item Short Form Survey scores for the mental and physical components were 54 ± 13 and 34 ± 7, with no difference in scores between patients fitted for a prosthesis and those who were not (P > .05). CONCLUSION: Patients undergoing a TFA after TKA due to failure of the TKA are more likely to be fit for a prosthesis; however, they reported no better quality of life and satisfaction compared with patients not fit for a prosthesis. LEVELS OF EVIDENCE: Level III, Therapeutic.

Lymphedema Is a Significant Risk Factor for Failure After Primary Total Hip Arthroplasty.

BACKGROUND: Lymphedema is a chronic disease characterized by fluid buildup and swelling that can lead to skin and soft-tissue fibrosis and recurring soft-tissue infections. Literature with regard to the increased risk of complications following a surgical procedure in patients with lymphedema is emerging, but the impact of lymphedema in the setting of primary total hip arthroplasty (THA) remains unknown. The purpose of this study was to review outcomes following primary THA performed in patients with lymphedema compared with a matched cohort without lymphedema. METHODS: Using our institutional total joint registry and medical records, we identified 83 patients (57 were female and 26 were male) who underwent THA with ipsilateral lymphedema. For comparison, these patients were matched 1:6 (based on sex, age, date of the surgical procedure, and body mass index [BMI]) to a group of 498 patients without lymphedema who underwent primary THA for osteoarthritis. Subsequently, postoperative complications and implant survivorship were evaluated for each group. The mean follow-up for each group was 6 years. Survivorship was compared between cohorts using Kaplan-Meier methodology and included both survivorship free of infection and survivorship free of reoperation or revision. Univariate Cox regression analysis was utilized to assess the association between patient factors for the time to event outcomes noted above. RESULTS: In patients with a history of lymphedema, there was an increased risk of complications (hazard ratio [HR], 1.97; p < 0.01), including reoperation for any cause (HR, 3.16; p < 0.01) and postoperative infection (HR, 4.48; p < 0.01). The 5-year infection-free survival rate was 90.3% for patients with lymphedema compared with 97.7% for patients without lymphedema (p < 0.01). CONCLUSIONS: Patients with lymphedema are at increased risk for complications, including reoperation and infection, following primary THA. These data emphasize the importance of appropriate preoperative counseling in this population and should encourage efforts to identify methods to improve outcomes, including further investigation of the effects of preoperative optimization of lymphedema prior to THA and methods for improved perioperative management. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Value of ultrasound-guided aspiration of hip arthroplasties performed in an orthopedic clinic by orthopedic surgeons.

Background: Total joint arthroplasties continue to increase as do periprosthetic joint infections (PJIs). Ultrasound-guided aspiration can yield useful synovial fluid for analysis while avoiding radiation exposure. This study presents a high-yield, ultrasound-guided technique with analysis of aspiration results. Methods: All consecutive ultrasound-guided aspirations of hip arthroplasties performed from May 2016 through to April 2019 were retrospectively reviewed. Patient demographic information, component specifics, presence of draining sinus, and inflammatory markers were recorded. Results of aspiration including volume, appearance, lavage use, synovial fluid differential leukocyte count, synovial neutrophil percent, and culture results were recorded. Surgical results, specimen cultures, and surgeon description of purulence were recorded. Aspiration results were compared to the surgical specimen results in all patients who underwent reoperations. Results: Review of 349 hip aspirations demonstrated accuracy of 87 %, sensitivity of 83 %, specificity of 89 %, positive predictive value of 79 %, and negative predictive value 91 %. Surgical and aspiration cultures matched in 81 % of cases. Bloody aspirates and aspirates obtained after lavage had less accuracy at 69 % and 60 %, respectively. Specificity was 100 % for cultures obtained with lavage and 91 % for bloody aspirates. Synovial leukocyte count and neutrophil percentage was obtained in 85 % of aspirations, and cultures were obtained in 98 % of aspirates. Contamination rate was 2 %. Conclusion: Ultrasound-guided aspirations aid in the diagnosis of PJI. The use of lavage to obtain fluid is helpful when aspiration cultures are positive. Bloody aspirates are less accurate but have high specificity. A low contamination rate and 88 % accuracy results with this meticulous technique.

Free Flap Coverage for Complex Primary and Revision Total Knee Arthroplasty.

BACKGROUND: Free flap coverage in the setting of a total knee arthroplasty is rare. The purpose of the current study was to evaluate the outcome of patients who underwent a free flap to assist with soft-tissue coverage following a complex total knee arthroplasty. METHODS: The authors used their institutional total joint registry to retrospectively review patients undergoing a free soft-tissue flap in the setting of complex primary and revision total knee arthroplasty. Among 29,069 primary and 6433 revision total knee arthroplasties from 1994 to 2017, eight (0.02 percent) required a free flap for wound coverage. This included three primary total knee arthroplasties (0.01 percent) for posttraumatic arthritis and five revision total knee arthroplasties (0.07 percent) in the setting of infection. Median follow-up was 4 years. RESULTS: Free flaps included vertical rectus abdominis (n = 3), anterior lateral thigh (n = 2), latissimus (n = 2), and transverse rectus abdominis (n = 1). There were no total flap losses; however, one patient required additional skin grafting. Reoperation occurred in six patients, of which four were revisions of the total knee arthroplasty for infection (n = 2) and tibial component loosening (n = 2). One patient ultimately underwent transfemoral amputation for persistent infection. Following reconstruction, there was improvement in the median Knee Society Score (49 versus 82; p = 0.03) and total range of motion between preoperative and postoperative assessments (70 degrees versus 85 degrees; p = 0.14). CONCLUSION: Free flap coverage in the setting of total knee arthroplasty was associated with a high rate of reoperation; however, the limb was able to be preserved in the majority of patients, with a reasonable functional outcome. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Outcomes of operatively treated interprosthetic femoral fractures.

AIMS: The prevalence of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) is rising in concert with life expectancy, putting more patients at risk for interprosthetic femur fractures (IPFFs). Our study aimed to assess treatment methodologies, implant survivorship, and IPFF clinical outcomes. METHODS: A total of 76 patients treated for an IPFF from February 1985 to April 2018 were reviewed. Prior to fracture, at the hip/knee sites respectively, 46 femora had primary/primary, 21 had revision/primary, three had primary/revision, and six had revision/revision components. Mean age and BMI were 74 years (33 to 99) and 30 kg/m2 (21 to 46), respectively. Mean follow-up after fracture treatment was seven years (2 to 24). RESULTS: Overall, 59 fractures were classified as Vancouver C (Unified Classification System (UCS) D), 17 were Vancouver B (UCS B). In total, 57 patients (75%) were treated with open reduction and internal fixation (ORIF); three developed nonunion, three developed periprosthetic joint infection, and two developed aseptic loosening. In all, 18 patients (24%) underwent revision arthroplasty including 13 revision THAs, four distal femoral arthroplasties (DFAs), and one revision TKA: of these, one patient developed aseptic loosening and two developed nonunion. Survivorship free from any reoperation was 82% (95% confidence interval (CI) 66.9% to 90.6%) and 77% (95% CI 49.4% to 90.7%) in the ORIF and revision groups at two years, respectively. ORIF patients who went on to union tended to have stemmed knee components and greater mean interprosthetic distance (IPD = 189 mm (SD 73.6) vs 163 mm (SD 36.7); p = 0.546) than nonunited fractures. Patients who went on to nonunion in the revision arthroplasty group had higher medullary diameter: cortical width ratio (2.5 (SD 1.7) vs 1.3 (SD 0.3); p = 0.008) and lower IPD (36 mm (SD 30.6) vs 214 mm (SD 32.1); p < 0.001). At latest follow-up, 95% of patients (n = 72) were ambulatory. CONCLUSION: Interprosthetic femur fractures are technically and biologically challenging cases. Individualized approaches to internal fixation versus revision arthroplasty led to an 81% (95% CI 68.3% to 88.6%) survivorship free from reoperation at two years with 95% of patients ambulatory. Continued improvements in management are warranted. Cite this article: Bone Joint J 2021;103-B(7 Supple B):122-128.