Operative treatment of nonunions in the elderly: Clinical and radiographic outcomes in patients at minimum 75 years of age.

BACKGROUND: Limited information exists on nonunion treatment in the elderly. This retrospective study evaluates whether results of operative treatment of nonunion of the humerus or femur in patients aged ≥ 75 years are comparable to those in younger patients. METHODS: We identified patients age ≥ 75 years with a nonunion of humerus or femur treated with open reduction and internal fixation. The Non-Union Scoring System was calculated. Complications, clinical outcome, and radiographic findings were assessed. Primary endpoint was nonunion healing. A literature review compared time to healing of humeral and femoral nonunion in younger populations. RESULTS: We identified 45 patients treated for a nonunion of humerus or femur with > 12 months follow-up. Median age was 79 years (range 75-96). Median time to presentation was 12 months (range 4-127) after injury, median number of prior surgeries was 1 (range 0-4). Union rate was 100%, with median time to union 6 months (range 2-42). Six patients underwent revision for persistent nonunion and healed without further complications. CONCLUSIONS: Using a protocol of debridement, alignment, compression, stable fixation, bone grafting and early motion, patients aged 75 years or older can reliably achieve healing when faced with a nonunion of the humerus or femur. LEVEL OF EVIDENCE: IV.

The performance of PROMIS computer adaptive testing for patient-reported outcomes in hip fracture surgery: a pilot study.

INTRODUCTION: Patient-reported outcome measures (PROMs) are essential to patient-centered care in orthopaedics. PROMIS measures have demonstrated reliability, validity, responsiveness, and minimal floor and ceiling effects in various populations of patients receiving orthopaedic care but have not yet been examined in hip fracture patients. This pilot study sought to evaluate the psychometric performance of the PROMIS Physical Function (PROMIS PF) and Pain Interference (PROMIS PI) computer adaptive tests and compare these instruments with legacy outcome measures in hip fracture patients. METHODS: This study included 67 patients who were 27-96 years old (median 76) and underwent osteosynthesis for a proximal femoral fracture. At 3, 6, and/or 12 months follow-up, patients completed both legacy (mHHS, SF-36-PCS, and VAS for pain) and PROMIS questionnaires (PROMIS PF and PROMIS PI). Respondent burden and floor/ceiling effects were calculated for each outcome measure. Correlation was calculated to determine concurrent validity between related constructs. RESULTS: A strong correlation was found between PROMIS PF and mHHS (rho = 0.715, p < 0.001) and moderately strong correlation between PROMIS PF and SF-36 PCS (rho = 0.697, p < 0.001). There was also a moderately strong correlation between the VAS and the PROMIS PI (rho = 0.641, p < 0.001). Patients who completed PROMIS PF were required to answer significantly fewer questions as compared with legacy PROMs (mHHS, SF-36). For the PROMIS measures, 1% of patients completing PROMIS PF achieved the highest allowable score while 34% of patients completing PROMIS PI achieved the lowest allowable score. Of the legacy outcome measures, 31% of patients completing the VAS for pain achieved the lowest allowable score and 7% of patients completing the mHHS achieved the highest allowable score. CONCLUSIONS: The results of this study support the validity of PROMIS CATs for use in hip fracture patients. The PROMIS PF was significantly correlated with SF-36 PCS and mHHS while requiring fewer question items per patient relative to the legacy outcome measures.

Surgical outcomes of dual-plate fixation for periprosthetic femur fractures around a stable hip arthroplasty stem.

INTRODUCTION: The incidence of periprosthetic femur fractures is increasing. Multiple treatment methods exist to treat fractures surrounding stable hip arthroplasty implants including locking plate fixation, cable fixation, allograft augmentation, and revision arthroplasty. No consensus regarding optimal treatment has been reached, and significant complications remain. Recently, biomechanical studies have demonstrated the benefits of orthogonal dual-plate fixation, but little clinical data exist. The purpose of the current study was to investigate the clinical and radiographic outcomes of dual-plated periprosthetic femur fractures around stable hip stems. MATERIALS AND METHODS: Patients with periprosthetic femur fractures following hip arthroplasty with a stable femoral stem treated with dual-plate fixation were identified through chart review at a single institution. Fracture classification, fixation characteristics, radiographic outcomes, clinical outcomes and complications including re-operation were recorded. RESULTS: Over a 12-year period, 31 patients (mean age 77 years at surgery, range 48-94) underwent dual plating by three traumatologists for implant-stable periprosthetic femur fractures surrounding a hip arthroplasty stem. There were 27 Vancouver B1-type and 9 inter-prosthetic fractures. Average follow-up was 2 years. Of the 26 patients with minimum 6-month follow-up, 24 (92%) united after index surgery (mean time to union 6.0 months, range 1.5-14.0). Mean time to full weight-bearing post-operatively was 2.6 months (range 1.5-4.0 months). Two patients required secondary surgery to address nonunion. CONCLUSIONS: Dual-plating achieved high union rates with an acceptable complication profile for the treatment of periprosthetic femur fractures surrounding a stable hip arthroplasty stem. Our preferred fixation construct involves a lateral plate spanning the entire femur secured with non-locking bicortical screws supplemented with an anteriorly based reconstruction plate. Additional prospective research is required to confirm the results of this study.

Validating the Patient Reported Outcomes Measurement Information System (PROMIS) computerized adaptive tests for upper extremity fracture care.

BACKGROUND: Computerized adaptive testing (CAT) for patient-reported outcomes (PROs) is a developing area within orthopedic surgery. Our objective was to validate the Patient Reported Outcomes Measurement Information System (PROMIS) CATs for upper extremity fracture care. We sought to correlate PROMIS with legacy PROs and to investigate floor and ceiling effects. METHODS: Patients who underwent open reduction and internal fixation of upper extremity trauma were prospectively enrolled. Legacy PROs included the visual analog scale for pain, the Disabilities of the Arm, Shoulder and Hand questionnaire, the University of California-Los Angeles Shoulder Rating Scale, the Mayo Elbow Performance Score, and the 36-Item Short Form Health Survey. PROMIS CATs included Physical Function (PROMIS PF), PROMIS Pain Interference (PROMIS Pain), and PROMIS Upper Extremity (PROMIS UE). Correlations between the PROs were calculated as were the absolute and relative floor and ceiling effect. RESULTS: The study prospectively enrolled 174 patients with upper extremity trauma. There was moderate to high correlation between PROMIS UE CAT and legacy upper extremity-specific PROs (ρ = 0.42-0.79), and high correlation between the PROMIS PF CAT and the 36-Item Short Form Health Survey Physical Component Summary (ρ = 0.71, P < .001). The visual analog scale for pain, University of California-Los Angeles Shoulder Rating Scale, Constant Score, and Mayo Elbow Score demonstrated a significant absolute ceiling effect (20.5%-23.7%), whereas the PROMIS PF, PROMIS UE, and PROMIS Pain CATs demonstrated no absolute ceiling effect. CONCLUSION: PROMIS PF, Pain, and UE correlate well with legacy PROs in a upper extremity trauma population, with less absolute floor or ceiling effects. This study provides preliminary evidence for the utility of PROMIS CATs in upper extremity trauma patients.

An alternative technique for greater tuberosity fractures: use of the mesh plate.

INTRODUCTION: Isolated greater tuberosity (GT) fractures (AO 11-A1) tend to occur in the younger patient population and are poorly managed by most precontoured proximal humerus locking plates. The goal of this study was to identify and assess an alternative treatment strategy for greater tuberosity fractures. MATERIALS AND METHODS: A retrospective review of all cases of isolated greater tuberosity fractures treated with a 2.4/2.7 mesh plate (Synthes) between 2010 and 2015 was conducted. Patient demographics, operative reports, and clinical notes were reviewed. The time to radiographic union was assessed. Clinical outcomes were retrieved from patients at their follow-up visits or via mailed Disabilities of the Arm, Shoulder, Hand (DASH) questionnaires. RESULTS: Ten patients with isolated GT fractures treated with mesh plating were identified with an average age of 47.1 years. The average radiographic follow-up was 7.2 months and the average clinical follow-up was 8.0 months. The mean time to union was 8.5 weeks. Two patients underwent elective hardware removal. The mean DASH at final follow-up was 28.2 (±22.4), while the mean DASH work was 13.6 (±19.1). CONCLUSION: We have identified a viable alternative treatment option for the surgical management of isolated greater tuberosity fractures using a mesh plate that can be contoured to the patient's anatomy. Surgeons should be aware of this option for select patients.

Comminuted olecranon fractures: biomechanical testing of locked versus minifragment non-locked plate fixation.

INTRODUCTION: Open reduction and internal fixation has long been accepted as optimal treatment for displaced olecranon fractures based on poor results seen with conservative management. With the presence of comminution, tension-band wiring constructs are contraindicated due to tendency to compress through fragments, thereby shortening the articular segment. Therefore, plate fixation is typically employed. Our hypothesis was that in a comminuted fracture model, 2.7 mm reconstruction plating without locking screws will perform equally to 3.5 mm locked plating in terms of fracture displacement and rotation (shear). MATERIALS AND METHODS: A three-part comminuted olecranon fracture pattern was created in nine matched pairs of cadaveric specimen using an oscillating saw in standardized, reproducible fashion. Each matched pair was then randomized to receive either 2.7 mm reconstruction plating or 3.5 mm proximal ulna locked plating. Random allocation software was used to assign the 2.7 mm plate construct to either the right or left side of each pair with the contralateral receiving the 3.5 mm plate construct. Specimens were cyclically loaded simulating passive range of motion exercises commonly performed during rehabilitation. Displacement and rotation in relation to the long axis of the ulna were measured through motion capture. Fragment gapping and rotation was quantified following 100 cycles at 10 N and again following 100 cycles at 500 N. RESULTS: No significant differences were detected between the 2.7 and 3.5 mm plates in fracture rotation or gapping following loads at 10 N (0.5° and 0.7°; 0.6 and 1.2 mm; respectively; p > 0.05) or 500 N (2.3° and 1.6°; 3.8 and 3.1 mm; respectively; p > 0.05) loading. Fragment rotation and gapping were positively correlated within each plate construct (R 2 > 0.445; p < 0.05). CONCLUSIONS: 2.7 mm plating is an alternative to 3.5 mm locked plating with decreased plate prominence without significantly sacrificing displacement and rotational control. This is beneficial in fracture patterns where the traditional dorsal plating does not offer optimal screw trajectory.

Plate fixation and bone grafting of distal clavicle nonunions: radiologic and functional outcomes.

INTRODUCTION: The optimal treatment for distal clavicle nonunions remains unknown. Small series have reported outcomes following distal fragment excision and various fixation techniques. We present the clinical, radiographic and functional outcomes after superior plating or double (superior and anteroinferior) plating in combination with bone grafting as treatment for distal clavicle nonunions. METHODS: We collected demographic and radiographic data from a consecutive series of ten patients with symptomatic nonunion of the distal clavicle treated since 1998. Functional outcomes were assessed, as well as the visual analogue scale (VAS) score. RESULTS: The mean clinical follow-up was 41.4 months (range of 12-158 months). The mean radiological follow-up was 30.6 months (range of 3-158 months). All nonunions healed as demonstrated by subsidence of clinical symptoms and radiographic criteria. The average time to union was 3.7 months (range of 2-8 months). The mean The Disabilities of the Arm, Shoulder and Hand (DASH) score was 11.9 (range of 0-62.5) and mean VAS score was 0.9 at follow-up. CONCLUSION: This study illustrates good clinical, radiologic and functional outcomes in ten patients with distal clavicle nonunion treated with superior or double (superior and anteroinferior) plating in combination with bone grafting. Double-plating can be considered an alternative to superior plating offering better resistance against the pulling effect of the arm with the use of smaller fixation plates.

Dual mini-fragment plating for midshaft clavicle fractures: a clinical and biomechanical investigation.

BACKGROUND: We sought to evaluate clinical and biomechanical outcomes of dual mini-fragment plate fixation for clavicle fractures. We hypothesized that this technique would produce an anatomical reduction with good clinical outcomes, be well tolerated by patients, and demonstrate equivalent biomechanics to single plating. METHODS: Dual mini-fragment plating was performed for 17 isolated, displaced midshaft clavicle fractures. Functional outcomes and complications were retrospectively reviewed. A sawbones model compared dual plating biomechanics to a (1) superior 3.5-mm locking reconstruction plate, or (2) antero-inferior 3.5-mm locking reconstruction plate. RESULTS: On biomechanical testing, with anterior loading, dual plating was significantly more rigid than single locked anterior-plating (p = 0.02) but less rigid than single locked superior-plating (p = 0.001). With superior loading, dual plating trended toward higher rigidity versus single locked superior-plating (p = 0.07) but was less rigid than single locked anterior-plating (p = 0.03). No statistically significant differences in axial loading (p = 0.27) or torsion (p = 0.23) were detected. Average patient follow-up was 16.1 months (12-38). Anatomic reduction was achieved and maintained through final healing (average 14.7 weeks). No patient underwent hardware removal. Average 1-year DASH score was 4.0 (completed in 88 %). CONCLUSIONS: Displaced midshaft clavicle fractures can be effectively managed with dual mini-fragment plating. This technique results in high union rates and excellent clinical outcomes. Compared to single plating, dual plating is biomechanically equivalent in axial loading and torsion, yet offers better multi-planar bending stiffness despite the use of smaller plates. This technique may decrease the need for secondary surgery due to implant prominence and may aid in fracture reduction by buttressing butterfly fragments in two planes.

The use of the 95-degree-angled blade plate in femoral nonunion surgery.

INTRODUCTION: The 95-degree-fixed angle blade plate has been in use for decades for both acute femoral fractures and nonunions. Our objective was to examine the results of use by a single surgeon of the 95-degree-angled blade plate in proximal and distal femoral nonunion surgery. PATIENTS AND METHODS: The nonunion database of a single surgeon over a 16 year period was used to identify all proximal and distal femoral nonunions that were treated with open reduction and internal fixation using the 95-degree-angled blade plate. There were 78 cases in which the blade plate was used, and 68 of 78 (87.2 % follow-up rate) were followed to a final outcome, which was defined as complete healing of the nonunion, conversion to arthroplasty, or amputation. Failure was defined as revision surgery for persistence of nonunion, conversion to arthroplasty prior to healing, or amputation. Three patients who failed were lost to follow-up prior to a final outcome. RESULTS: In the 71 patients who were followed to failure or complete follow-up, the rate of healing with one surgery was 77.5 % (55 of 71). Eight of 16 failures required a second surgery for persistence of nonunion and eventually went on to heal the nonunion. Eleven of the 16 failures were in patients who had a known infected nonunion. When the 21 cases of infected nonunions were excluded, the healing rate for aseptic nonunions with one surgery alone using the 95-degree-angled blade plate was 91.2 % (52 of 57) compared with 47.6 % (10 of 21) in the infected nonunion group (p < 0.0001). Eleven patients who had healed their nonunion underwent all or partial removal of the implant for irritation or prominence. CONCLUSION: The 95-degree-angled blade plate is an effective reduction aid and fixation device for aseptic nonunions of the proximal and distal femur with acceptable healing rates with one surgery alone.

Biomechanical strain characteristics of soft tissue biceps tenodesis and bony tenodesis.

BACKGROUND: Biomechanical analysis of biceps tenodesis procedures has historically focused on load to failure models. Minimal data exists for the analysis of biomechanical strain properties of the biceps tendon in a sub-failure, physiologic cadaver model. HYPOTHESIS: Tendon strain characteristics are different between bony and soft tissue tenodesis surgery, and the soft tissue tenodesis procedure reproduces a strain pattern more similar to the native biceps tendon. METHODS: Eight fresh frozen cadaver upper extremities were mounted onto a custom device that controls shoulder abduction and rotation. Strain on the tendon was measured using a differential variable reluctance transducer as the arm was moved through cycles of abduction and external rotation. Each arm was mounted once, and all 3 testing procedures were performed on each of the 8 specimens. Statistical analysis was completed using ANOVA, followed by multiple comparisons with Bonferroni correction. RESULTS: The bony tenodesis model placed higher strain on the biceps tendon than the soft tissue tenodesis (p = 0.025). Also, the bony tenodesis model increased the strain on the biceps tendon when compared to the native tendon (p = 0.031). In contrast, the soft tissue tenodesis did not significantly alter strain when compared to the native tendon (p = 0.089). CONCLUSION: The soft tissue tenodesis procedure better maintained the native strain environment when compared to the bony tenodesis using an interference screw. Due to this closer approximation of native biceps tendon biomechanics, the soft tissue procedure may be more preferable clinically than the bony tenodesis. LEVEL OF EVIDENCE: 1, Controlled Laboratory Study.

Botulinum Toxin as an Adjunctive Therapy for Immobilization of a Distal Humerus Fracture in Parkinson's Disease-Associated Psychosis: A Case Report.

BACKGROUND Attainment of extremity immobilization in orthopedic trauma patients experiencing psychosis is often uniquely challenging. Many fractures, including those of the distal humerus, require a period of immobilization postoperatively to optimize fracture healing. Patients with Parkinson's disease have also been shown to have lower rates of union after fracture compared to the general population. The combination of Parkinson's disease and associated psychosis requires heightened attention to those parameters that may hinder fracture healing, such as inadequate immobilization of the fracture. Botulinum toxin has previously been described as a potential adjunctive therapy for fracture immobilization but has not yet been described in the setting of distal humerus fractures. CASE REPORT A 75-year-old woman with Parkinson's disease-associated psychosis presented 2 weeks after open reduction and internal fixation of a distal third humeral shaft fracture due to failure of fixation and episodes of violent hallucinations. The patient underwent irrigation and debridement, and revision open reduction and internal fixation. Given her uncontrolled hallucinations, intramuscular botulinum toxin injections were given to the right triceps, biceps, and brachialis muscles to aid in the immobilization of the right extremity and protect the surgical site during the perioperative period. The patient subsequently followed up at the clinic 3 months postoperatively with ongoing fracture healing, evidenced by bridging callous and bone formation on radiographs, as well as a return of motion to the extremity. CONCLUSIONS Botulinum toxin may be a safe and effective adjunct for fracture immobilization in patients who are difficult to immobilize and have high fixation failure risk.

Botulinum toxin as adjunct therapy in surgical management of a periprosthetic scapular spine fracture: a case report.

Six months after undergoing reverse shoulder arthroplasty (RSA) a 73-year-old woman sustained a periprosthetic scapular spine fracture following a fall. She was treated with open reduction and internal fixation (ORIF), followed by botulinum toxin injection into the deltoid muscle to temporarily minimize strain at the fracture. Fracture union was achieved by 3 months, with excellent clinical function more than 1 year following fracture fixation and full resolution of deltoid function. Scapular spine fracture following RSA can be treated with ORIF and temporary deltoid paralysis using botulinum toxin in the immediate postoperative period to safely support fracture healing.

Total Hip Arthroplasty After Proximal Femoral Nailing: Preoperative Preparation and Intraoperative Surgical Techniques.

The combination of an aging population and increased utilization of total hip arthroplasty (THA) is leading to a higher incidence of conversion THA, defined as conversion from previous hip fracture surgery to THA. Conversion THA is a more technically challenging, time-consuming, and costly procedure compared to primary THA and frequently involve more medically complex patients. Thus, the aim of this review is to provide a rubric for surgeons to use when preparing for a conversion THA. We have assessed the compatibility of commonly available extraction devices with popular femoral nails. Furthermore, we review technical pearls for conversion THA including equipment planning, operative setup, intraoperative imaging, extraction sequencing, and troubleshooting commonly encountered obstacles.

Independent predictors of systemic inflammatory response syndrome for intramedullary nailing of femoral shaft fractures: Analysis of national inpatient sample database.

Background: The systemic inflammatory response syndrome (SIRS) is a clinical reaction that can occur due to a variety of stimuli. Reamed intramedullary femoral nailing is a common orthopedic surgery that has been shown to induce SIRS. To date, no nationwide analyses have been performed to evaluate the incidence, risk factors, and economic burdens of SIRS following intramedullary femoral nailing for femoral shaft fractures. The objective of this study is to investigate the independent predictors, incidence, post-operative, and economic burden of SIRS among patients treated with intramedullary nailing for femoral shaft fractures. Methods: We utilized the 2016-2019 National Inpatient Sample (NIS) to identify patients who underwent intramedullary femoral nailing and were diagnosed with non-infectious SIRS (NI-SIRS) based on ICD-10-CM coding. Identified patients who underwent intramedullary femoral nailing were dichotomized into SIRS and Non-SIRS groups to assess independent predictors of SIRS development, and to compare post-operative complications and costs. Results: A total of 65,240 patients with femur shaft fractures underwent IMFN, of which 665 (1.0 %) developed NI-SIRS. Patients with NI-SIRS had a higher incidence of laparotomy (OR = 13.97, p < 0.001), initial treatment with external fixation (OR = 1.845, p < 0.001), and late application of external fixation (OR = 4.884, p = 0.005). Routine discharge (OR = 0.491, p < 0.001) was less likely in patients with NI-SIRS. Length of stay (12.38 days vs 7.16 days, p < 0.001) and total charges ($278, 590 vs $145,118, p < 0.001) were both increased in patients with NI-SIRS. Conclusion: NI-SIRS is associated with increasing injury severity and post-operative complications. Those that developed NI-SIRS experienced higher healthcare resource utilization. Risk factors associated with development of NI-SIRS warrant further investigation.

Predictors of in-hospital surgical site infections in surgically managed acetabular fractures: A nationwide analysis.

Background: A surgical site infection (SSI) rate of 4%-8% has been reported in patients who undergo open reduction and internal fixation (ORIF) for acetabular fractures. Studies have identified risk factors for SSI, but none have performed a nationwide analysis of SSI in surgically managed acetabular fracture patients. Methods: The National Inpatient Sample (NIS) database was queried for patients who underwent ORIF for acetabular fractures from 2016 to 2019. Analysis was performed on all patients who underwent ORIF for acetabular fractures, as well as those who only underwent ORIF for isolated acetabular fractures. Clinical characteristics, hospital course, discharge disposition, and hospitalization costs were compared between groups. Multivariate regression analysis was conducted to assess predictors of SSI. Results: 41,725 patients undergoing acetabular fracture repair were identified, of which 490 (1.2%) developed SSI during hospitalization. Age (45.90 vs 49.90, p < 0.001) and Injury Severity Scale (5.99 vs 8.30, p < 0.001) were increased in patients who developed SSI. History of hypertension (HTN) (OR = 2.343, 95% CI 1.96-2.80, p < 0.001), longer hospital length of stay (30.27 days vs 10.00 days, p < 0.001) and total charges ($469,005 vs $193,032, p < 0.001) were associated with SSI. Lower rates of routine discharge were seen in SSI patients (OR = 0.333, 95% CI 0.260-0.426, p < 0.001). Higher rates of inpatient death were associated with SSI (OR = 2.210, 95% CI 1.172-4.17, p = 0.019). Multiple procedures in addition to acetabular fracture repair, iliac artery embolization, substance abuse, later time to internal fixation and HTN were predictive of SSI (p < 0.001). Conclusions: Severity of injury, time to fixation, and factors associated with compromised cardiovascular integrity were predictors of SSI. Identifying patients at risk for SSI should lead to clinical maneuvers that may optimize outcome.

Identifying alternative antibiotics that elute from calcium sulfate beads for treatment of orthopedic infections.

There has been increasing interest in the use of a synthetic absorbable calcium sulfate (CaSO4 ) for local antibiotic delivery in orthopaedic infections. The purpose of this study was to quantify elution kinetics of six antibiotics (amikacin, meropenem, fosfomycin, minocycline, cefazolin, and dalbavancin) from a clinically relevant CaSO4 bead model and compare elution and antimicrobial activity to the current clinical gold standards: vancomycin and tobramycin. Antibiotic-loaded synthetic CaSO4 beads were immersed in phosphate buffered saline and incubated at 37°C. Eluent was harvested at eight time points over 28 days. Antibiotic concentrations were measured by high performance liquid chromatography to quantify elution rates. CaSO4 beads demonstrated burst release kinetics. Dalbavancin, cefazolin, and minocycline all demonstrated similar elution profiles to vancomycin. Amikacin and meropenem demonstrated favorable elution profiles and durations of above-minimum inhibitory concentration when compared to tobramycin. Clinical Significance: This study provides important novel data regarding the utility of amikacin, meropenem and dalbavancin as alternative choices to place in CaSO4 carriers when treating orthopaedic infections.

Orthopaedic expert opinion, testimony, and the physician as a defendant.

Medicolegal issues continue to challenge orthopaedic surgeons. Although health reform legislation has passed Congress, the first phase has not incorporated any significant changes regarding liability reform for practicing orthopaedic surgeons. Medical malpractice, personal injury, and workers' compensation litigation remains an issue for patients and physicians. Although orthopaedic surgeons can be defendants, it is more likely that they will be retained as treating physicians or experts as part of the litigation process. The involvement of a qualified physician as an expert witness is essential to the outcome of any litigation involving medical issues. As triers of the facts, the judge and jury members rely on quality medical testimony. Expert witness testimony can be a time-consuming process. A physician who assumes the role must be able to spend the time necessary to do a good job. A prepared expert witness can have a profound effect on litigation. A poorly prepared physician expert witness can be harmful to a case and risks the loss of prestige, honor among colleagues, and future work. Sanctions may be imposed by professional organizations. Most importantly, a physician working within the legal system must remain honest and tell nothing but the truth.

Assessment of malreduction standards for the syndesmosis in bilateral CT scans of uninjured ankles.

AIMS: Malreduction of the syndesmosis has been reported in up to 52% of patients after fixation of ankle fractures. Multiple radiological parameters are used to define malreduction; there has been limited investigation of the accuracy of these measurements in differentiating malreduction from inherent anatomical asymmetry. The purpose of this study was to identify the prevalence of positive malreduction standards within the syndesmosis of native, uninjured ankles. METHODS: Three observers reviewed 213 bilateral lower limb CT scans of uninjured ankles. Multiple measurements were recorded on the axial CT 1 cm above the plafond: anterior syndesmotic distance; posterior syndesmotic distance; central syndesmotic distance; fibular rotation; and sagittal fibular translation. Previously studied malreduction standards were evaluated on bilateral CT, including differences in: anterior, central and posterior syndesmotic distance; mean syndesmotic distance; fibular rotation; sagittal translational distance; and syndesmotic area. Unilateral CT was used to compare the anterior to posterior syndesmotic distances. RESULTS: A difference of anterior to posterior syndesmotic distance > 2 mm was observed in 89% of ankles (n = 190) on unilateral CT assessment. Using bilateral CT, we found that 35% (n = 75) of normal ankles would be considered malreduced by current malreduction parameters. In 50 patients (23%), only one parameter was anomalous, 18 patients (8%) had two positive parameters and seven patients (3%) had three. Difference in fibular rotation had the lowest false positive rate of all parameters at 6%, whereas posterior syndesmotic distance difference had the highest at 15%. CONCLUSION: In this study, 35% of native, uninjured syndesmoses (n = 75) would be classified as malreduced by current diagnostic standards on bilateral CT and 89% had an asymmetric incisura on unilateral CT (n = 190). Current radiological parameters are insufficient to differentiate mild inherent anatomical asymmetry from malreduction of the syndesmosis. Cite this article: Bone Joint J 2021;103-B(1):178-183.

Thermal Stability and in Vitro Elution Kinetics of Alternative Antibiotics in Polymethylmethacrylate (PMMA) Bone Cement.

BACKGROUND: Amikacin, meropenem, minocycline, and fosfomycin have potential clinical utility for orthopaedic infections; however, their suitability for use in polymethylmethacrylate (PMMA) is poorly understood. The purpose of this study was (1) to quantify the thermal stability of these antibiotics at clinically relevant temperatures and (2) to determine the elution pharmacodynamics of these alternative antibiotics in vitro from PMMA beads of different sizes. METHODS: Polymerization temperatures of 10-mm PMMA beads were measured over time to generate a simulated heating curve. Aqueous solutions of tobramycin, amikacin, meropenem, minocycline, and fosfomycin were subjected to the temperature curves, followed by incubation at 37°C. Minimum inhibitory concentrations of each antibiotic were evaluated against Staphylococcus aureus, Escherichia coli, and Acinetobacter baumannii. High-dose 4.5-mm, 6-mm, and 10-mm antibiotic-laden PMMA beads (10% antibiotic by weight) were submerged individually in a phosphate-buffered saline solution and incubated at 37°C. Antibiotic elution was determined with use of high-performance liquid chromatography with mass spectrometry. RESULTS: Tobramycin, amikacin, and fosfomycin demonstrated thermal stability and maintained antimicrobial activity for 28 days. Minocycline and meropenem lost antimicrobial activity against all 3 organisms after 48 hours and 7 days, respectively. Elution concentrations, rates, and cumulative drug mass for tobramycin, amikacin, and meropenem were orders of magnitude higher than minocycline and fosfomycin at each time point. CONCLUSIONS: This study identified notable differences in thermal stability and elution among antibiotics used to treat infections. Amikacin exhibited activity similarly to tobramycin. Meropenem demonstrated favorable elution kinetics and thermal stability in the initial 7-day period. CLINICAL RELEVANCE: Amikacin and meropenem show pharmacologic promise as potential acceptable alternatives for local delivery in PMMA for treatment of orthopaedic infections. Further work to establish clinical relevance and utility is needed.

The effects of locking inserts and overtorque on the mechanical properties of a large fragment locking compression plate.

PURPOSE: The study was to determine the effect of locking hole inserts and their insertion torque on the fatigue life of a large fragment Locking Compression Plate (LCP) under bending forces. METHODS: Fatigue strength of the LCP was examined using cyclic three-point bend testing at 80% yield strength of the construct. Locking hole inserts were used in 2, 4, and 6-hole of a 12-hole plate to simulate three different working lengths. Within each working length, plates were tested without locking inserts serving as the control group. In the experimental groups, inserts were tightened to manufacturer recommendations (4 Nm) and using overtorque (8 Nm). RESULTS: Significantly fewer cycles to failure were observed in control groups versus the locking hole insert groups for all working lengths (2-hole: 4 Nm p = 0.003, 8 Nm p = 0.003; 4-hole: 4 Nm p = 0.02, 8 Nm p < 0.001; 6-hole: 4 Nm p = 0.004, 8 Nm p < 0.001). There was a statistically significant increase in fatigue strength when using overtorque in the 4-hole (p = 0.04) and 6-hole (p = 0.01) defect groups. This was not shown in the 2-hole defect group (p = 0.99). CONCLUSIONS: By placing locking inserts in the empty locking regions of Combi holes along the working length, the number of cycles to failure was increased. Tightening inserts to twice the recommended insertion torque further increased cycles to failure in longer working length models. A longer fatigue life has the potential to decease the incidence of plate failure especially in the setting of delayed union due to poor intrinsic healing capacity, fractures in the geriatric population, osteoporosis and periprosthetic fractures.