Nam Hoon Moon

Surgical Outcomes of Biologic Fixation for Subtrochanteric Fracture Using Locking Compression Plates

Purpose This study aimed to evaluate the surgical outcomes of biologic plating using locking compression plate-distal femur (LCP-DF) in patients with subtrochanteric fracture of the femur. Materials and Methods Between January 2010 and December 2013, 28 consecutive patients with subtrochanteric fractures of the femur, treated with biologic fixation using LCP-DF, were enrolled. Preoperative values, including patient age, sex, body mass index, fracture type, type of lung injury, and surgical timing from injury to surgery, were retrospectively evaluated. Radiologic assessments included time to union, coronal alignment, rotational alignment, and complications such as implant breakage and screw breakage. Adverse events, including postoperative fat embolism and adult respiratory distress syndrome, infection during the follow-up period, and walking ability at the last follow-up visit, were assessed. Results Union was achieved in 27 patients (96.4%) after a mean duration of 5.4 months (range, 3-14 months). No patients developed fat embolism or adult respiratory distress syndrome during the hospitalization period of this study. Conclusion Biologic fixation using locking compression plates may represent a safe surgical option which can be utilized in patients with subtrochanteric fracture regardless of injury severity, surgical timing, fracture type, and presence of lung injury.

C-reactive protein for early detection of postoperative systemic infections in intertrochanteric femoral fractures

BACKGROUND This retrospective cohort study investigated perioperative C-reactive protein (CRP) value for early detection of postoperative systemic infective complications in elderly patients with intertrochanteric femoral fracture. METHODS A total of 250 patients aged ≥65 years, with intertrochanteric femoral fractures that were surgically treated between January 2011 and December 2015 were included. CRP value was measured preoperatively and on postoperative day (POD) 3, 5, and 10, and analyzed with regard to postoperative systemic infections, delirium, and death within 1 year. The patients were divided into two groups according to postoperative systemic infection, and perioperative CRP responses between the two groups were comparedusing t-test (or Man-Whitney test where appropriate). The receiver operator characteristic (ROC) curves of CRP value were used to determine the best-supported cut-off values for identifying postoperative systemic infections. Systemic infections were reclassified as pulmonary and extra-pulmonary infections. RESULTS The mean CRP values preoperatively and on POD 3, 5, and 10 were 2.82, 10.10, 3.74, and 1.89 mg/dL, respectively. Postoperative systemic infections, delirium, and death within 1 year were noted in 35 (14.0%), 30 (12.0%), and 45 (18.0%) patients, respectively. The CRP value in patients with postoperative systemic infections significantly elevated on POD 5 and 10 (p < 0.001, p < 0.001), and cut-off values were 4.71 and 1.59 mg/dL on POD 5 and 10, respectively. Postoperative delirium and death within 1 year were observed more often in the group with postoperative systemic infections (p = 0.003, p = 0.014). Although preoperatively elevated CRP values did not influence the postoperative CRP responses, they were significantly associated with delirium (p = 0.015). CONCLUSIONS The CRP value on POD 5 is the earliest predictor of postoperative systemic infections in elderly patients with intertrochanteric femoral fractures that are managed surgically. Moreover, when the CRP value on POD 5 is >4.71 mg/dL, the possibility of postoperative systemic infections should be considered. LEVEL OF EVIDENCE III, Retrospective cohort study.

High energy injury is a risk factor for preoperative venous thromboembolism in the patients with hip fractures: A prospective observational study

BACKGROUND The purpose of this study was to identify the incidence of preoperative venous thromboembolism (VTE), and determine if high energy hip fracture affects preoperative VTE occurrence. METHODS Three-hundred nine patients (244 low and 61 high energy injuries) treated between March 2015 and March 2017 were included in this study. Indirect multidetector computed tomographic venography for the detection of preoperative VTE was performed at admission. The incidence of preoperative VTE was compared between high and low energy injury hip fractures. Logistic regression analysis was used to identify independent risk factors for preoperative VTE. RESULTS The overall incidence of preoperative VTE was 18.4% (56 of 305 patients). Preoperative VTE was identified in 17 (27.9%) and 39 (16.0%) patients in the high and low energy injury groups, respectively (p = 0.034). Multivariate logistic regression analysis showed that high energy injury, history of VTE, and myeloproliferative disease were significant predictive factors of preoperative VTE (OR = 2.451; 95% CI = 1.227-4.896, OR = 11.174; 95% CI = 3.500-35.673, OR = 6.936; 95% CI = 1.641-29.321, respectively) CONCLUSION: Because high energy hip fracture is significantly associated with preoperative VTE occurrence, preoperative evaluation and proper thromboprophylaxis should be performed for patients with a high-energy hip fracture.

An Uncommon Case of Bilateral Pathologic Hip Fractures: Antiviral Drug-induced Osteomalacia in a Patient with Hepatitis B

The long-term use of adefovir and tenofovir–antiviral medications commonly used to treat chronic hepatitis B–can be associated with proximal renal tubular dysfunction resulting in significant hypophosphatemic osteomalacia. However, there have been few reports about pathological fractures requiring surgical stabilization in cases of antiviral drug-induced hypophosphatemic osteomalacia. We present the case of a 51-year-old man who sustained bilateral pathological hip fractures associated with antiviral drug-induced hypophosphatemic osteomalacia. To treat a lamivudine-resistant hepatitis-B viral infection, the patient received adefovir for 7 years followed by tenofovir for the subsequent 3 years. He had suffered from polyarthralgia and generalized weakness for 2 years prior to presentation at our clinic. Misdiagnosis and inadequate management of his condition accelerated weakness of the bone matrix and ultimately induced pathological fractures. The patient was managed via cementless total hip arthroplasty on the left hip and internal fixation on the right hip. This case highlights that orthopaedic surgeons should consider the possibility of hypophosphatemic osteomalacia if patients receiving antiviral drugs complain of polyarthralgia and generalized weakness.

Arthroscopic Management of Intraarticular Screw Perforation after Surgical Treatment of an Acetabular Posterior Wall Fracture: A Case Report

Although surgical techniques for treating acetabular fracture are evolving, the use of periacetabular screws is common, and their placement in acetabular surgery is still technically demanding. For instance, intraarticular screw perforation is a serious complication that may occur during surgical treatment of an acetabular fracture. Here, we describe the case of a 50-year-old female who experienced an intraarticular screw perforation after surgical treatment of a posterior acetabular wall fracture. Removal of the perforated screw was performed arthroscopically based on its ability to offer minimally invasive access to the hip joint. One year after removal of the screw, no radiological signs of osteoarthritic changes were observed. The patient regained normal ambulation without limitations to range of motion or hip pain. To our knowledge, this is the first report on the use of arthroscopy to treat intraarticular screw perforation after surgical treatment of an acetabular fracture.

Diagnostic strategy for elderly patients with isolated greater trochanter fractures on plain radiographs

BackgroundIsolated greater trochanter (GT) fractures are relatively rare and few studies have assessed the appropriate diagnostic and therapeutic strategies for these fractures. When initial plain radiographs show an isolated GT fracture, underestimation of occult intertrochanteric extension may result in displacement of a previously non-displaced fracture. This study examined the clinical results and value of different diagnostic strategies in elderly patients with isolated GT fractures on plain radiographs.MethodsBetween January 2010 and January 2015, 30 patients with initial plain radiographs showing isolated GT fractures were examined using MRI, bone scanning and/or CT for suspected occult intertrochanteric extension. We assessed the sensitivity, specificity, and positive and negative predictive value of each test. In addition, we noted the location of the fracture or soft-tissue injury on MRI in addition to treatment results.ResultsAll 30 patients had osteoporosis and fractures caused by minor trauma. MRI revealed isolated GT fractures in nine patients and occult intertrochanteric fractures in 21 patients. Using the MRI-based diagnosis as a reference, the results showed that plain radiographs, bone scans, and CT scans can be used for supplementary examination but they are not appropriate as confirmatory tests for these fractures. However, in patients with both isolated GT fractures seen on plain radiographs and increased uptake in only the GT area on bone scans, MRI revealed isolated GT fractures. The fractures were treated surgically in 20 patients and conservatively in 10 patients with satisfactory clinical results.ConclusionsWe confirmed that MRI-based examination is useful in all symptomatic elderly patients whose plain radiographic findings reveal isolated GT fractures. However, we suggest that there is a need to establish a diagnostic strategy through increased understanding of the available diagnostic methods. We believe that surgical treatment should be considered in patients with occult intertrochanteric fractures that are detected on MRI.

Amount of Weight-Bearing During Tilt Table Inclination, With Neutral and Unilateral Knee Flexion Postures

Objective To analyze the amount of weight-bearing during tilt table increments, with a review of neutral and unilateral knee flexion postures. Methods There were 17 healthy participants enrolled in this study. The subjects were tilted from 10° to 90°, and their body weight was measured at each 10° increment. In the first test, both plantar pressures, with the subjects in neutral posture, were recorded. During the second and third tests, the angle of inclination was thus recorded and increased, with the subjects in unilateral knee flexion posture; flexion was maintained at 25° by attaching a cylindrical support to the tilt table at the level of the popliteal fossa. Results The study was divided into two types of postures: neutral and unilateral knee flexion. The percentage of body weight (%BW) between each leg during neutral posture was noted as not being statistically significant. The %BW of one side during tilt table inclination was significantly different between the two postures at 10° to 80° (p<0.05). The weight during unilateral knee flexion posture was lower as analyzed, regardless of tilt table inclination compared with that in neutral posture. We note that fifty percent of the ratio of %BW was noted at 33.12° and 38.76° in neutral and flexion postures, respectively. Conclusion The unilateral knee flexion could induce the effect of decreased body weight compared with non-flexion side. The results of this study will help in setting a safe and quantitative percentage of weight-bearing on the lower extremity during tilt training.

Reliable anatomical landmarks for minimizing leg-length discrepancy during hip arthroplasty using the lateral transgluteal approach for femoral neck fracture

BACKGROUND The purpose of this study was to describe our experience of a preoperative templating technique, and to investigate the most reliable anatomical reference to minimize leg length discrepancy (LLD) during hip arthroplasty using the lateral transgluteal approach for femoral neck fractures. We hypothesized that the medial fracture tip and greater trochanter would be viable alternative anatomical References METHODS: A total of 156 hip arthroplasty cases were enrolled in the present study (103 women, 114 hemiarthroplasties, 42 total hip arthroplasties). Preoperative acetate overlay templating was conducted based on pelvic anteroposterior radiographs. Three different anatomical references were used to determine the bony resection level, including the uppermost point of the lesser trochanter, uppermost point of the greater trochanter, and medial fracture tip. The accuracy of preoperative templating and the reliability of each anatomical reference for minimizing LLD were assessed. RESULTS Significant differences in postoperative LLD after hip arthroplasty between the three groups were identified. Post-hoc analysis showed that postoperative LLD in group A was significantly larger than that in groups B or C in hip arthroplasty. CONCLUSION The results of this study suggest that the use of the lesser trochanter as an anatomical reference to determine the level of femoral neck osteotomy should be discouraged, and that the medial fracture tip and greater trochanter may be better alternatives when using the lateral transgluteal approach.

Comparative study between biologic plating and intramedullary nailing for the treatment of subtrochanteric fractures: Is biologic plating using LCP-DF superior to intramedullary nailing?

BACKGROUND The objective of this study is to evaluate the outcome measures of subtrochanteric fractures between biologic plating and intramedullary nailing and determine if biologic plating is superior to intramedullary nailing. METHODS Between March 2009 and December 2015, 81 patients with subtrochanteric fractures were enrolled (52 males and 29 females; 31 treated with biologic plating and 50 with intramedullary nailing). Biologic plating was conducted consecutively between May 2011 and March 2013 and intramedullary nailing was performed for the rest of period. Perioperative outcomes including operation time and blood loss during the operation; postoperative radiologic outcomes including union, time to union, coronal alignment, and shortening of the femur; and clinical outcomes including walking ability and pain were evaluated. The biologic plating group was compared with the intramedullary nailing group as a historical control. RESULTS No significant differences were identified for bony union and time to union between the two different fixation methods Coronal alignment was significantly better in the biologic plating group than in the intramedullary nailing group (p<0.016). Postoperative coronal alignment was the only risk factor associated with the nonunion of subtrochanteric fractures (unadjusted OR: 1.915, 95% CI: 0.190 - 19.273; adjusted OR: 0.042, 95% CI: 0.000 - 21.517; p=0.320). CONCLUSION Surgical outcomes using LCP-DF are comparable to those using intramedullary nailing. Further clinical studies with a larger sample size are required to show the advantage of biologic plating for the treatment of subtrochanteric fractures.

Radiographic Outcomes of Osteosynthesis Using Proximal Femoral Nail Antirotation (PFNA) System in Intertrochanteric Femoral Fracture: Has PFNA II Solved All the Problems?

Purpose We evaluated the geometric discrepancies between the proximal femur in Koreans and two types of proximal femoral nail using plain radiographs. Materials and Methods A total of 100 consecutive patients (38 treated with proximal femoral nail antirotation [PFNA], 62 PFNA II) with intertrochanteric fracture were retrospectively identified. The minimum follow up period was 32 months. The geometric analysis of the proximal femur was performed using preoperative true hip antero-posterior radiographs of the unaffected side, and the data were compared with the PFNA and PFNA II dimensions. Postoperative assessments were performed using postoperative radiographs for the proximal protruding length of nail tip, quality of reduction, implant position and the presence of lateral cortical impingement. Results The geometric dimensions of the proximal femur were different between the two proximal femoral nail types. No impingement was detected in patients treated with PFNA II, whereas 13 cases of lateral impingement were observed in patients treated with PFNA. A significant association was observed between the short proximal femur and the presence of lateral cortical impingement (P=0.032) and between impingement and intraoperative reduction loss (P=0.012). Proximal protrusion of the nail tip was seen in 71 patients and no difference was observed between two groups. Conclusion Our study demonstrates that the flat lateral surface of PFNA II can avoid lateral cortical impingement, which provide better fixation for intertrochanteric fracture. However, there was still a problem associated with longer proximal end of PFNA II compared with the proximal femoral length in Korean.