• Hip & pelvis
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• v.36 no.2
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• pp.144-154
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• 2024

Purpose: The objective of this study was to assess postoperative direct medical expenses and medical utilization of elderly patients who underwent either hemiarthroplasty (HA) or internal fixation (IF) for treatment of a femoral intertrochanteric fracture and to analyze differences according to surgical methods and age groups. Materials and Methods: Data from the 2011 to 2018 Korean National Health Insurance Review & Assessment Service database were used. Risk-set matching was performed for selection of controls representing patients with the same sex, age, and year of surgery. A comparative interrupted time series analysis was performed for evaluation of differences in medical expenses and utilization between the two groups. Results: A total of 10,405 patients who underwent IF surgery and 10,405 control patients who underwent HA surgery were included. Medical expenses were 18% lower in the IF group compared to the HA group during the first year after the fracture (difference-in-difference [DID] estimate ratio 0.82, 95% confidence interval [CI] 0.77-0.87, P<0.001), and 9% lower in the second year (DID estimate ratio 0.91, 95% CI 0.85-0.99, P=0.018). Length of hospital stay was significantly shorter in the IF group compared to the HA group during the first two years after time zero in the age ≥80 group. Conclusion: A noticeable increase in medical expenses was observed for patients who underwent HA for treatment of intertrochanteric fractures compared to those who underwent IF over a two-year period after surgery. Therefore, consideration of such findings is critical when designing healthcare policy support for management of intertrochanteric fractures.

• Hip & pelvis
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• v.34 no.3
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• pp.150-160
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• 2022

Purpose: The purpose of this study is to determine risk factors that affect mortality following osteoporotic hip fracture in patients 50 years or older using the National Health Insurance Service (NHIS) sample cohort 2.0 database. Materials and Methods: Data from 2,533 patients who satisfied the inclusion criteria for the NHIS sample cohort 2.0 database were used in this study. Data from patients who suffered osteoporotic hip fractures between 2002-2015 were used. An analysis of correlations between the incidence of osteoporotic hip fractures and various factors (sex, age, underlying diseases, etc.) was performed. Analysis of the associations between the mortality of osteoporotic hip fracture and the various factors with hazard ratio (HR) was performed using Cox regression models. Results: Patient observation continued for an average of 38.12±32.09 months. During the observation period, a higher incidence of hip fracture was observed in women; however, higher mortality following the fracture was observed in men (HR=0.728; 95% confidence interval [CI], 0.635-0.836). The incidence and mortality of fractures increased when there were increasing age, more than three underlying diseases (HR=1.945; 95% CI, 1.284-2.945), cerebrovascular diseases (HR=1.429; 95% CI, 1.232-1.657), and renal diseases (HR=1.248; 95% CI, 1.040-1.497). Also, higher mortality was observed in patients who were underweight (HR=1.342; 95% CI, 1.079-1.669), current smokers (HR=1.338; 95% CI, 1.104-1.621), and inactivity (HR=1.379; 95% CI, 1.189-1.601). Conclusion: Male gender, the presence of cerebrovascular or kidney disease, a more than three underlying diseases, underweight, a current smoker, and inactivity were risk factors that increased mortality.

• Hip & pelvis
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• v.34 no.1
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• pp.18-24
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• 2022

Purpose: The aim of this study was to determine whether there is a correlation between the type and stability of intertrochanteric fractures caused by low-energy trauma and gluteus muscle volume. Materials and Methods: A total of 205 elderly (>65 years) patients with intertrochanteric fractures caused by low-energy trauma treated from January 2018 to December 2020 were included in this study. The mean age of patients was 81.24 years (range, 65-100 years). Fractures were classified according to the Jensen modification of the Evans classification. The cross-sectional area of the contralateral gluteus muscle (minimus, medius, and maximus) was measured in preoperative axial computed tomography slices. An analysis and comparison of age, body mass index (BMI), weight, height, and the gluteus muscle area in each fracture type group was performed. Results: In the uni-variable analysis, statistically significant taller height was observed in patients in the stable intertrochanteric fracture (modified Evans 1 and 2) group compared with those in the unstable intertrochanteric fracture (modified Evans 3, 4, and 5) group (P<0.05). In addition, significantly higher BMI-adjusted gluteus muscle area (gluteus muscle area/BMI) was observed for the stable intertrochanteric fracture group compared with the unstable intertrochanteric fracture group except for the BMI-adjusted gluteus minimus area (P=0.112). In multivariable analysis, only the BMI-adjusted gluteus maximus (P=0.042) and total gluteus areas (P=0.035) were significantly higher in the stable group. Conclusion: Gluteal muscularity around the hip, especially the gluteus maximus, had a significant effect on the stability of intertrochanteric fractures.

• Hip & pelvis
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• v.34 no.1
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• pp.10-17
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• 2022

Purpose: This study was conducted in order to assess changes in hip muscles by comparing results of preoperative and postoperative computed tomography (CT) in older patients who underwent surgery for treatment of hip fracture. Materials and Methods: A total of 50 patients (aged ≥65 years) who underwent surgery for treatment of intertrochanteric fractures (25 patients) and femoral neck fractures (25 patients) between February 2013 and February 2019 and underwent preoperative and postoperative pelvic CT were enrolled in the study. The cross-sectional area, attenuation and estimates of muscle mass of the gluteus medius, gluteus minimus, iliopsoas, and rectus femoris on the uninjured side were measured. Basic patient data (sex, age, height, weight, body mass index [BMI], bone mineral density [BMD], Harris hip score [HHS], and length of follow-up) were collected from medical records. Results: No significant differences in sex, age, height, weight, BMI, BMD, HHS, and length of follow-up were observed between the two groups. No significant difference in the cross-sectional areas and attenuations of gluteus medius and gluteus minimus was observed after surgery; however, a statistically significant decrease was observed in those of iliopsoas and rectus femoris after surgery. Lower estimates with statistical significance of muscle mass of the iliopsoas and rectus femoris were observed on postoperative CT. Conclusion: Muscle mass of the hip flexor (iliopsoas, rectus femoris) showed significant decreases on postoperative CT compared with preoperative CT. Based on these findings, selective strengthening exercise for hip flexor should be beneficial in rehabilitation of hip fractures.

• Hip & pelvis
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• v.34 no.3
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• pp.161-171
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• 2022

Purpose: The number of obese patients seeking total hip arthroplasty (THA) continues to expand despite body mass index (BMI) cutoffs. We sought to determine the outcomes of THA in the morbidly obese patient, and hypothesized they would have comparable outcomes to two cohorts of obese, and normal weight patients. Materials and Methods: THA performed on morbidly obese patients (BMI >40 kg/m²) at a single academic center from 2010 until 2020 were retrospectively reviewed. Eighty morbidly obese patients were identified, and matched in a 1:3:3 ratio to control cohorts with BMI 30-40 kg/m² and BMI <30 kg/m². Acute postoperative outcomes and BMI change after surgery were evaluated for clinical significance with univariate and regression analyses. Cox proportional hazard ratio was calculated to evaluate prosthetic joint infection (PJI) and revision surgery through follow-up. Mean follow-up was 3.9 years. Results: In the acute postoperative period, morbidly obese patients trended towards increased hospital length of stay, facility discharge and 90-day hospital returns. At final follow-up, a higher percentage of morbidly obese patients had clinically significant (>5%) BMI loss; however, this was not significant. Cox hazard ratio with BMI <30 kg/m² as a reference demonstrated no significant difference in survival to PJI and all-cause revision in the morbidly obese cohort. Conclusion: Morbidly obese patients (BMI >40 kg/m²) require increased resource expenditure in the acute postoperative period. However, they are not inferior to the control cohorts (BMI <30 kg/m², BMI 30-40 kg/m²) in terms of PJI or all-cause revisions at mid-term follow-up.

• Hip & pelvis
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• v.34 no.1
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• pp.35-44
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• 2022

Purpose: Osteosynthesis has been recommended for treatment of Pauwels type III femoral neck fractures in young patients. However, no implant of choice has been reported so far. This study was conducted in order to compare the fixation stability of two conventional fixation methods with three different novel fixed angle devices in this type of fracture. Materials and Methods: A total of 25 composite femurs (4th Generation Saw bone; Pacific Research Laboratories, USA) corresponding to human bone were used. Pauwels type III fracture type was uniformly reproduced. Specimens were fixed with a cannulated screw, cannulated screw with cable, and Intertan nail, dynamic hip screw, and IKEY nail. Measurement of failure loads and the rotational change of the femoral head fragment was performed for evaluation of fixation stability. Results: All implants were compared with cannulated screw and dynmaic hip screw. No meaningful improvement was observed for the cannulated screw with cable compared with the cannulated screw and dynamic hip screw. Meaningful improvement in load-to-failure and y-rotation and z-rotation was observed for both the Intertan nail and IKEY nail compared with the cannulated screw. However, compared with the dynamic hip screw, only the IKEY nail showed improvement in the same profile but the Intertan nail did not. Conclusion: Among novel fixed angle devices, meaningful improvement was observed for the IKEY nail compared with conventional implants. Strengths of this implant include biomechanical stability and simplicity of surgical technique, indicating that it may be another good option for osteosynthesis of Pauwels type III femoral neck fractures.

• Hip & pelvis
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• v.34 no.1
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• pp.45-55
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• 2022

Purpose: The aim of this study was to evaluate the short-term outcome of physiotherapy in patients with acetabular labral tears and to assess the effectiveness of physiotherapy according to the severity of the labral tear. Materials and Methods: Thirty-five patients who underwent physiotherapy for treatment of symptomatic acetabular labral tears were enrolled. We evaluated the severity of the acetabular labral tears, which were classified based on the Czerny classification system using 3-T MRI. Clinical findings of microinstability and extra-articular pathologies of the hip joint were also examined. The International Hip Outcome Tool 12 (iHOT12) was use for evaluation of outcome scores pre- and post-intervention. Results: The mean iHOT12 score showed significant improvement from 44.0 to 73.6 in 4.7 months. Compared with pre-intervention scores, significantly higher post-intervention iHOT12 scores were observed for Czerny stages I and II tears (all P<0.01). However, no significant difference was observed between pre-intervention and post-intervention iHOT12 scores for stage III tears (P=0.061). In addition, seven patients (20.0%) had positive microinstability findings and 22 patients (62.9%) had findings of extra-articular pathologies. Of the 35 patients, eight patients (22.9%) underwent surgical treatment after failure of conservative management; four of these patients had Czerny stage III tears. Conclusion: The iHOT12 score of patients with acetabular labral tears was significantly improved by physiotherapy in the short-term period. Improvement of the clinical score by physiotherapy may be poor in patients with severe acetabular labral tears. Determining the severity of acetabular labral tears can be useful in determining treatment strategies.

• Hip & pelvis
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• v.34 no.1
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• pp.56-61
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• 2022

Purpose: Histopathologic analysis of femoral head specimens following total hip arthroplasty (THA) is a routine practice that represents a significant use of health care resources. However, it occasionally results in discovery of undiagnosed hematopoietic malignancy and other discrepant diagnoses such as avascular necrosis. The purpose of this study was to determine the rate of discordant and discrepant diagnoses discovered from routine histopathological evaluation of femoral heads following THA and perform a cost analysis of this practice. Materials and Methods: A review of patients undergoing primary THA between 2004-2017 was conducted. A comparison of the surgeon's preoperative and postoperative diagnosis, and the histopathologic diagnosis was performed. In cases where the clinical and histopathology differed, a review determined whether this resulted in a change in clinical management. Medicare reimbursement and previously published cost data corrected for inflation were utilized for cost calculations. Results: A review of 2,134 procedures was performed. The pathologic diagnosis matched the postoperative diagnosis in 96.0% of cases. Eighty-three cases (4.0%) had a discrepant diagnosis where treatment was not substantially altered. There was one case of discordant diagnosis where lymphoma was diagnosed and subsequently treated. The cost per discrepant diagnosis was $141,880 and per discordant diagnosis was $1,669 when using 100% Medicare reimbursement and Current Procedural Terminology (CPT) code combination 88304+88311. Conclusion: Histopathologic analysis of femoral head specimens in THAs showed an association with high costs given the rarity of discordant diagnoses. Routine use of the practice should be at the discretion of individual hospitals with consideration for cost and utility thresholds.

• Hip & pelvis
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• v.34 no.4
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• pp.203-210
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• 2022

Purpose: Total hip arthroplasty (THA) using the direct anterior approach (DAA) is known to have a learning curve. The purpose of this study was to review cases where surgery was performed by an arthroplasty surgeon transitioning from the posterior approach (PA) to the DAA. We hypothesized similar complication rates and improvements in surgical duration over time. Materials and Methods: A review of 2,452 consecutive primary THAs was conducted. Surgical duration, length of stay (LOS), surgical complications, decrease in postoperative day (POD) 1 hemoglobin, transfusion rates, POD 0 and POD 1 pain scores, incision length, leg length discrepancy (LLD), and radiographic cup position were recorded. Results: No differences in surgical duration were observed after the first 50 DAA cases. A shorter LOS was observed for the DAA, and statistical difference was appreciated after the first 100 DAA cases. There were no differences in periprosthetic fractures. A higher rate of infections and hip dislocations were observed with the PA. The PA showed an association with higher transfusion rates without significant difference in POD 1 decrease in hemoglobin over the first 100 DAA cases. Similar POD 0 and POD 1 pain scores with a smaller incision were observed for the first 100 DAA cases. The DAA cohort showed less variation in cup inclination, version, and LLD. Conclusion: DAA is safe and non-inferior in terms of reduced LOS, smaller incision, and less variation in cup position. Fifty DAA cases was noted to be the learning curve required before no differences in duration between approaches were observed.

• Hip & pelvis
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• v.34 no.4
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• pp.219-226
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• 2022

Purpose: The purpose of this study was to examine the clinical outcomes and efficacy of hip resurfacing arthroplasty (HRA) in patients with osteonecrosis of the femoral head after the failure of porous tantalum rod insertion without rod removal. Materials and Methods: Conversion to hip resurfacing arthroplasty was performed in 10 patients (11 hips) with a mean period of 14.9 months after the primary surgery. The mean follow-up period was 73.7 months. Analysis of pre and postoperative range of motion (ROM), University of California at Los Angeles (UCLA) activity score, modified Harris hip score, and visual analog scale (VAS) pain score was performed. Radiographic analysis of component loosening and osteolysis was performed. Results: The postoperative ROM showed significant improvement (P<0.05), excluding flexion contracture. The modified Harris hip score showed improvement from 65.82 to 96.18, the UCLA score showed improvement from 4.18 to 8.00, and the VAS pain score was reduced from 6.09 to 1.80. All scores showed statistically significant improvement (P<0.05). No component loosening or osteolysis was detected by radiographic analysis. Conclusion: Satisfactory results were obtained from conversion hip resurfacing arthroplasty after failure of porous tantalum rod insertion without rod removal. The findings of this study demonstrate the advantages of HRA, including no risk of trochanteric fracture and no bone loss around the tantalum rod. In addition, the remaining porous tantalum rod provided mechanical support, which reduced the potential risk of femoral neck fracture or loosening. This technique can be regarded as a favorable treatment option.