Biomechanics of Proximal Hamate Autograft in Scaphoid Nonunion.

Purpose Treatment of proximal scaphoid fractures remains a challenge with a risk of nonunions and avascular necrosis due to its retrograde blood supply. The ipsilateral proximal hamate has been described as a viable autograft option for osteochondral reconstruction of the proximal scaphoid. Our study evaluated the changes in the contact area and pressure of the radioscaphoid joint after proximal hamate autograft reconstruction. Methods Thin sensors (Tekscan Inc., Boston, MA) were placed in the radiocarpal joints of six fresh-frozen cadaveric forearms. Each specimen's tendons were loaded to 150 N in neutral, 45-degree flexion/extension positions through five cycles. Through a dorsal wrist approach, the proximal 10 mm of the scaphoid and hamate was excised. The proximal hamate autograft was affixed to the scaphoid with K-wires. Peak contact pressures and areas at the scaphoid facet were determined and averaged across loading cycles. Results At the radioscaphoid facet, peak contact pressures were equivalent, although an increasing trend in the neutral and extended wrist position was seen. At the radiolunate facet, contact pressure had an increasing trend in the hamate reconstructed wrists in all wrist positions. Contact areas had a decreasing trend and were nonequivalent at the radioscaphoid facet in the hamate reconstructed wrist. Conclusion After hamate autograft, the contact areas were not equivalent between the native and reconstructed wrists but contact pressures were equivalent in the facets. The proximal hamate has a more pointed morphology compared with the proximal scaphoid, which would explain the change in contact area in the hamate autografted wrist. Our study suggests hamate autograft may present a viable reconstruction for the proximal pole of the scaphoid without significantly altering peak contact pressures at the radioscaphoid facet.

Evaluation of Antegrade Intramedullary Compression Screw Fixation of Metacarpal Shaft Fractures in a Cadaver Model.

PURPOSE: Surgical options for displaced metacarpal shaft fractures include the use of Kirschner wires, plates and screws, and most recently, intramedullary headless compression screws (IMHCS), which have been reported using only retrograde insertion through the metacarpal head. We evaluated IMHCS fixation of metacarpal shaft fractures through an antegrade approach in a cadaver model. METHODS: We performed antegrade placement of IMHCS in 10 cadaver hands including all 5 digits (total of 50). Displaced transverse proximal metacarpal shaft fractures were created and reduced with a retrograde guidewire from the metacarpal head across the shaft fracture and exiting the metacarpal base. This was retrieved through a 6-mm dorsal wrist incision and overdrilled before the placement of a 4.1-mm-diameter IMHCS in the ring finger and a 4.7-mm screw in all other metacarpals. After IMHCS placement, carpometacarpal (CMC) joint violation was measured along with the optimal starting point for the guidewire on the metacarpal head relative to the dorsal cortex. RESULTS: In all 50 metacarpals, we achieved successful fracture reduction and fixation without violating the extensor mechanism at the wrist. Our retrograde guidewire entry point through the metacarpal head ranged from 4.2 to 4.7 mm volar to the dorsal cortex. The actual area of CMC joint violated by IMHCS placement was largest in the index CMC joint (4.9%), followed by the middle (3.7%), little (2.9%), ring (0.5%), and thumb joints (0.2%). CONCLUSIONS: Placement of IMHCS through an antegrade approach from the CMC joint can be performed effectively for all transverse metacarpal fractures, including the thumb, using a limited incision. There is minimal violation of the articular surfaces of the trapezium, capitate, and hamate for the thumb, middle, ring, and little metacarpals. CLINICAL RELEVANCE: Antegrade IMHCS fixation successfully avoids the potential morbidity of creating a metacarpal head articular surface or extensor mechanism defect at the metacarpophalangeal joint seen with the retrograde approaches.

An Anatomical Study of Metacarpal Morphology Utilizing CT Scans: Evaluating Parameters for Antegrade Intramedullary Compression Screw Fixation of Metacarpal Fractures.

PURPOSE: This study evaluated metacarpal morphology for antegrade placement of intramedullary headless compression screws (IMHCS) for metacarpal fracture fixation. METHODS: We analyzed 100 hand computed tomography scans to quantify cortical thickness, intramedullary diameter, and metacarpal lengths. In addition, dorsal or ulnar overhang of the metacarpals over their respective carpal bones was measured. We also predicted optimal entry points for guidewire placement at the metacarpal head. RESULTS: The ring finger metacarpal had the narrowest medullary canal width (coronal, 2.8 mm; sagittal, 3.5 mm). Not counting the thumb, the little finger metacarpal had the widest midshaft medullary width of 4.1 mm in the coronal plane and the middle metacarpal was widest in the sagittal plane with canal width of 3.9 mm. On average, there was maximal dorsal overhang at the base of the middle metacarpal (4.2 mm) and maximal ulnar overhang at the base of the small metacarpal (3.9 mm). The optimal entry point for guidewire placement over each metacarpal head was approximately 3.5 to 3.8 mm volar to the dorsal cortex. CONCLUSIONS: Minimum IMHCS diameters of 3.5 mm for the ring and 4.0 mm for the index, middle and little fingers are necessary to achieve interference fit within the medullary canal. Minimum screw lengths of 38 mm would be needed to ensure 6 mm fixation past the midshaft of the metacarpals. Antegrade IMHCS for fixation of proximal metacarpal fractures may be most feasible with thumb, middle, and little finger metacarpals because there was larger dorsal or ulnar overhang to allow screw placement without violating the carpometacarpal joints. CLINICAL RELEVANCE: Our analysis provides a reference guide for intramedullary screw sizes for each metacarpal of the hand to achieve interference fit with fracture fixation. Furthermore, the dorsal and ulnar overhangs of the metacarpal bases suggest the practicality of antegrade IMHCS fixation.

Prospective spine at risk program for prevalence of intracanal spine lesions in pediatric hereditary multiple osteochondromas.

STUDY DESIGN: Retrospective cohort study OBJECTIVES: To determine prevalence of hereditary multiple osteochondromas (HMO) and utility of MRI surveillance in a prospective Spine at Risk (SAR) program. Unidentified intraspinal exostoses in HMO can lead to neurologic injury in children during sedated procedures but no MRI guidelines exist. We sought to determine the prevalence and age of intraspinal exostoses from MRIs, and indications for MRI surveillance. METHODS: Retrospective review was performed of pediatric HMO patients who underwent total spine MRIs at a single institution after a prospective SAR program was instituted. Charts were reviewed for MRI indication and findings, symptoms, surgery, and location of other exostoses. Fisher's exact test was used to compare categorical variables and T test to compare continuous variables. Predictive value of pelvic/rib exostoses was calculated for intraspinal lesions. RESULTS: Forty-three patients with HMO underwent total spine MRIs with average age of 11.5 years. Fifteen (35%) patients had exostoses on vertebral column, eight (19%) had intra-canal spinal exostoses. Higher prevalence of spine lesions occurred in symptomatic patients than asymptomatic (any spinal lesion: 73% prevalence in symptomatic vs 22% in asymptomatic, p < 0.005; intra-canal spinal lesion: 46% vs 9%, p < 0.05). Only two of the 11 'symptomatic presentations' could be attributable to intracanal spinal exostoses. Only one intra-canal exostosis found on asymptomatic surveillance was treated surgically. Presence of pelvic or rib exostoses were not strongly predictive of intra-canal lesions (23% PPV, 85% NPV, 63% sensitivity, 51% specificity). CONCLUSIONS: Even with the presence of intra-canal exostoses, true symptomatic lesions are rare. Rib and pelvic lesions were not predictive of intra-canal lesions in our population. We recommend obtaining MRIs at time of preoperative evaluation in asymptomatic children old enough to not need sedation, or in patients with true neurologic symptoms to prevent unnecessary sedation of younger children for surveillance MRI. LEVEL OF EVIDENCE: III.

Frailty predicts mortality and complications in chronologically young patients with traumatic orthopaedic injuries.

BACKGROUND: As morbidity and mortality from traumatic orthopaedic injuries continues to rise, increased research is being conducted on how to best predict complications in at risk patients. Recently, frailty indices have been validated in a variety of surgical subspecialties as predictors of morbidity and mortality. However, the vast majority of research has been conducted on geriatric patient populations, with little evidence on patients who are chronologically young. The purpose of this study was to evaluate the role of a modified frailty index (mFI) in predicting mortality and complications after pelvis, acetabulum, and lower extremity trauma in patients of all ages. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried from 2005 to 2014 for all patients who underwent surgery for pelvis, acetabulum, and lower extremity trauma. The sample size was divided into geriatric (age ≥ 60) and young (age < 60) cohorts. The mFI score was calculated for each patient. Bivariate analysis was performed using logistic regression and a chi-square test to determine the relationship between mFI and both primary and secondary outcomes while adjusting for age. Univariate analysis and multivariate analyses were performed. All analyses were done using SAS 9.4 (Cary, NC) and a p < 0.05 was considered significant. RESULTS: 56,241 patients were identified to have undergone surgery for pelvis, acetabulum, or lower extremity trauma. 28% of patients were identified under the age of 60. In the young cohort, mFI was a strong predictor of thirty-day mortality (OR 11.02, 95% CI 6.26-19.39, p < 0.001). With regards to Clavien-Dindo grade IV complications, MFI is also a strong predictor in the young cohort (OR 28.82, 95% CI 16.05-51.77, p < 0.001). CONCLUSION AND RELEVANCE: The mFI score was a significant predictor of morbidity and mortality in chronologically young orthopaedic trauma patients. The use of the mFI score can provide an individualized risk assessment to interdisciplinary teams for perioperative counseling and to improve outcomes.

Variations in Treatment of C2 Fractures by Time, Age, and Geographic Region in the United States: An Analysis of 4818 Patients.

BACKGROUND: The optimal form of treatment for C2 spine fractures is controversial. This investigation analyzed the variations in treatment of C2 fractures over time, by age group, and by geographic location. METHODS: The Nationwide Emergency Department Sample database was queried to identify patients 18 years and older who sustained C2 fracture without neurologic injury from 2006 to 2012. Subsequently, patients were further filtered based on the intervention they received: collar, halo, and surgery. Regions of hospital used in analysis were defined as Northeast, Midwest, South, and West. Linear regression models were used to analyze trends for C2 incidence rates and treatment type. Analysis of variance tests were used to determine differences among procedure groups when stratified by regions and age groups. RESULTS: Surgical intervention for C2 fracture increased from 36.5% in 2006 to 55.7% in 2012 (r = 0.116, P < 0.001). In contrast, the rate of halo use decreased from 57.8% in 2006 to 37.1% in 2012 (r = -0.139, P < 0.001). Surgery displayed increasing trend across all age groups. A greater proportion of patients in the Northeast were treated by collar compared with all other regions (P < 0.001). In contrast, halo use was significantly lower in the Northeast than the other 3 regions (P < 0.001). CONCLUSIONS: This investigation demonstrated that surgical management of C2 fractures is increasing in frequency over time and at all age groups. Furthermore, the treatment of these fractures varies by region-the Northeast had the highest incidence of collar use and lowest rate of halo use.

Variations in treatment of C1 fractures by time, age, and geographic region in the United States: An analysis of 985 patients.

The purpose of this investigation was to evaluate the variations in the treatment of C1 fractures over time, by age group, and by geographic region using a nationwide database. The Nationwide Emergency Department Sample (NEDS) database was queried to identify patients ≥18 years who sustained C1 fracture from 2006-2012. Patients were filtered based on the intervention they received: collar, halo, or surgery. Regions of hospital used in analysis were defined as Northeast, Midwest, South, and West. Surgical intervention for C1 fracture increased from 27.1% of cases in 2006 to 55.4% of cases in 2012 (P<0.001). The rate of collar treatment increased with increasing age. In contrast, rate of halo use decreased with increasing age. A greater proportion of patients in the Northeast were treated by collar compared to all other regions (P<0.001). We can conclude that there is considerable variation in the treatment of C1 fractures with regards to age and geographic region. Surgical treatment of these fractures is increasing over time. Future considerations should be given to developing treatment guidelines to decrease variation and potentially create cost-savings.

The frail fail: Increased mortality and post-operative complications in orthopaedic trauma patients.

OBJECTIVE: The burgeoning elderly population calls for a robust tool to identify patients with increased risk of mortality and morbidity. This paper investigates the utility of the MFI as a predictor of morbidity and mortality in orthopaedic trauma patients. DESIGN: Retrospective review of the NSQIP database to identify patients age 60 and above who underwent surgery for pelvis and lower extremity fractures between 2005 and 2014. MAIN OUTCOMES AND MEASURES: For each patient, an MFI score was calculated using NSQIP variables. The relationship between the MFI score and 30-day mortality and morbidity was determined using chi-square analysis. MFI was compared to age, American Society of Anesthesiologists physical status classification, and wound classifications in multiple logistic regression. RESULTS: Study sample consisted of 36,424 patients with 27.8% male with an average age of 79.5 years (SD 9.3). MFI ranged from 0 to 0.82 with mean MFI of 0.12 (SD 0.09). Mortality increased from 2.7% to 13.2% and readmission increased from 5.5% to 18.8% with increasing MFI score. The rate of any complication increased from 30.1% to 38.6%. Length of hospital stay increased from 5.3days (±5.5days) to 9.1days (±7.2days) between MFI score 0 and 0.45+. There was a stronger association between 30-day mortality and MFI (aOR for MFI 0.45+: 2.6, 95% CI: 1.7-3.9) compared to age (aOR for age: 1.1, 95% CI: 1.1-1.1) and ASA (aOR 2.5, 95% CI: 2.3-2.7). CONCLUSIONS AND RELEVANCE: MFI was a significant predictor of morbidity and mortality in orthopaedic trauma patients. The use of MFI can provide an individualized risk assessment tool that can be used by an interdisciplinary team for perioperative counseling and to improve outcomes.

Modified Frailty Index Is an Effective Risk Assessment Tool in Primary Total Hip Arthroplasty.

BACKGROUND: Frailty is described as decreased physiological reserve and typically increasing with age. Hospitals are being penalized for reoperations and readmissions, which can affect reimbursement. The purpose of this study was to determine if the modified frailty index (MFI) could be used as a risk assessment tool for preoperative counseling and to make an objective decision on whether to perform total hip arthroplasty (THA) on a frail patient. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried by Current Procedural Terminology code for primary THA (27130) from 2005 to 2014. MFI was calculated using 11 variables extracted from the medical record. Bivariate analysis was performed for outcomes and complications, and the multiple logistic regression model was used to compare MFI with other predictors of readmission, any complication, and reoperation. RESULTS: A total of 51,582 patients underwent primary THA during the study period. MFI was a significant and stronger predictor than the American Society of Anesthesiologists class and age for readmission (odds ratio [OR], 14.72; 95% confidence interval [CI], 6.95-31.18; P < .001), any complication (OR, 3.63; 95% CI, 1.64-8.05; P = .002), and reoperation (OR, 8.78; 95% CI, 3.67-20.98; P < .001). As MFI increased, adverse discharge, any complication, readmission, reoperation, and mortality significantly increased (P < .001). Rates of systemic complications and length of stay significantly increased with increasing MFI. CONCLUSION: MFI is a simple and effective risk assessment tool to preoperatively counsel and make an objective decision on whether to perform THA on a frail patient.

Modified Frailty Index Is an Effective Risk Assessment Tool in Primary Total Knee Arthroplasty.

BACKGROUND: "Frailty" is a marker of physiological decline of multiple organ systems, and the frailty index identifies patients who are more susceptible to postoperative complications. The purpose of this study is to validate the modified frailty index (MFI) as a predictor of postoperative complications, reoperations, and readmissions in patients who underwent primary total knee arthroplasty (TKA). METHODS: The American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2014 was queried by the Current Procedural Terminology code for primary TKA (27447). A previously described MFI was used to summate 11 variables in 5 organ systems. Bivariate analysis was performed for postoperative complications. A multiple logistic regression model was used to determine the relationship between MFI, American Society of Anesthesiologists score, and 30-day reoperation, controlling for age, gender, and body mass index. RESULTS: A total of 90,260 patients underwent primary TKA during the study period. As MFI score increased, 30-day mortality significantly increased (P < .001). In addition, significantly higher rates of postoperative complications (all P < .001) were observed with increasing MFI: infection, wound, cardiac, pulmonary, and renal complications; and any occurrence. More frail patients also had increasing odds of adverse hospital discharge disposition, reoperation, and readmission (all P < .001). Length of hospital stay increased from 3.10 to 5.16 days (P < .001), while length of intensive care unit stay increased from 3.47 to 5.07 days (P < .001) between MFI score 0 and ≥0.36. MFI predicts 30-day reoperation with an adjusted odds ratio of 3.32 (95% confidence interval, 1.36-8.11; P < .001). Comparatively, MFI was a stronger predictor of reoperation compared with American Society of Anesthesiologists score and age with adjustment for gender and body mass index. CONCLUSION: Utilization of the MFI is a valid method in predicting postoperative complications, reoperations, and readmissions in patients undergoing primary TKA and can provide an effective and robust risk assessment tool to appropriately counsel patients and aid in preoperative optimization.

Efficacy of Hybrid Plasma Scalpel in Reducing Blood Loss and Transfusions in Direct Anterior Total Hip Arthroplasty.

BACKGROUND: Allogeneic blood transfusions have inherent risk and direct cost in total hip arthroplasty. Anterior total hip arthroplasty has grown in popularity with increased utilization. This approach may offer an enhanced recovery but has been associated with increased blood loss. Several technologies have been developed including the Canady Hybrid Plasma Scalpel (CHPS) and Aquamantys Bipolar Sealer (BS) to decrease blood loss. METHODS: Two hundred forty-four consecutive patients undergoing anterior supine intermuscular total hip arthroplasty were separated by intraoperative cautery device (CHPS vs BS). Exclusion criteria included blood dyscrasias and contraindication to tranexamic acid. Demographic data, blood loss, transfusion requirements, and Harris Hip Scores were obtained. Differences between groups were evaluated using the Student t-test or Wilcoxon rank-sum test for continuous variables and chi-square test for categorical variables. RESULTS: There were no differences in demographic data between the groups. Patients in the CHPS group had a significantly smaller decrease in postoperative hemoglobin (-2.3 mg/dL vs -2.7 mg/dL, P < .05), estimated blood loss (240.3 mL vs 384.4 mL, P < .001), and calculated actual blood loss (1.11 L vs 2.47 L, P < .001). There were 12 transfusions in the BS group and none in CHPS group (P < .001). CONCLUSION: The use of the hybrid plasma scalpel resulted in significantly less blood loss and transfusions than the BS. Additionally, patients treated with the hybrid plasma scalpel had significantly shorter operative times and reduced hospital length of stay. The hybrid scalpel shows promise in reducing blood loss in anterior total hip arthroplasty and is a valuable tool in the multimodal approach to avoiding transfusions.

Polymicrobial ventriculitis involving Pseudomonas fulva.

Infections due to Pseudomonas fulva remain a rare but emerging concern. A case of ventriculitis due to Enterobacter cloacae and Pseudomonas fulva following placement of an external ventricular drain is described. Similar to other reports, the organism was initially misidentified as Pseudomonas putida. The infection was successfully treated with levofloxacin.