Ho-Rim Choi

Massachusetts General Hospital, Boston, Massachusetts, United States

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Publications (16)37.2 Total impact

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    ABSTRACT: Modular revision femoral components allow the surgeon to make more precise intraoperative adjustments in anteversion and sizing, which may afford lower dislocation rates and improved osseointegration, but may not offer distinct advantages when compared with less expensive monoblock revision stems. We compared modular and monoblock femoral components for revision of Paprosky Type I to IIIA femoral defects to determine (1) survivorship of the stems; and (2) complications denoted as intraoperative fracture, dislocation, or failure of osseointegration. Between 2004 and 2010, participating surgeons at three centers revised 416 total hip arthroplasties (THAs) with Paprosky Type I to IIIA femoral defects. Of those with minimum 2-year followup (343 THAs, mean followup 51 ± 13 months), 150 (44%) were treated with modular stems and 193 (56%) were treated with monoblock, cylindrical, fully porous-coated stems. During this time, modular stems were generally chosen when there was remodeling of the proximal femur into retroversion and/or larger canal diameters (usually > 18 mm). A total of 27 patients died (6%) with stems intact before 2 years, 46 THAs (13%) were lost to followup before 2 years for reasons other than death, and there was no differential loss to followup between the study groups. The modular stems included 101 with a cylindrical distal geometry (67%) and 49 with a tapered geometry (33%). Mean age (64 versus 68 years), percentage of women (53% versus 47%), and body mass index (31 versus 30 kg/m(2)) were not different between the two cohorts, whereas there was trend toward a slightly greater case complexity in the modular group (55% versus 65% Type 3a femoral defects, p = 0.06). Kaplan-Meier survivorship was calculated for the endpoint of aseptic revision. Proportions of complications in each cohort (dislocation, intraoperative fracture, and failure of osseointegration) were compared. Femoral component rerevision for any reason (including infection) was greater (OR, 2.01; 95% CI, 1.63-2.57; p = 0.03) in the monoblock group (27 of 193 [14%]) compared with the modular cohort (10 of 150 [7%]). Femoral component survival free from aseptic rerevision was greater in the modular group with 91% survival (95% CI, 89%-95%) at 9 years compared with 86% survival (95% CI, 83%-88%) for the monoblock group in the same timeframe. There was no difference in the proportion of mechanically relevant aseptic complications (30 of 193 [16%] in the monoblock group versus 34 of 150 [23%] in the modular group, p = 0.10; OR, 1.47; 95% CI, 0.86-2.53). There were more intraoperative fractures in the modular group (17 of 150 [11%] versus nine of 193 [5%]; OR, 2.2; 95% CI, 1.68-2.73; p = 0.02). There were no differences in the proportions of dislocation (13 of 193 [7%] monoblock versus 14 of 150 [9%] modular; OR, 0.96; 95% CI, 0.67-1.16; p = 0.48) or failure of osseointegration (eight of 193 [4%] monoblock versus three of 150 [2%] modular; OR, 1.92; 95% CI, 0.88-2.84; p = 0.19) between the two groups with the number of hips available for study. Although rerevisions were less common in patients treated with modular stems, aseptic complications such as intraoperative fractures were more common in that group, and the sample was too small to evaluate corrosion-related or fatigue concerns associated with modularity. We cannot therefore conclude from this that one design is superior to the other. Larger studies and pooled analyses will need to be performed to answer this question, but we believe modularity should be avoided in more straightforward cases if possible. Level III, therapeutic study.
    No preview · Article · Aug 2015 · Clinical Orthopaedics and Related Research
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    ABSTRACT: Although manipulation under anesthesia (MUA) has been considered effective first-line treatment for stiff total knee arthroplasty (TKA), there is no consensus regarding the usefulness of repeated MUA. The purpose of this study was to investigate the usefulness of repeated MUA performed for patients in whom satisfactory range of motion (ROM) was not achieved by MUA. The authors retrospectively reviewed 15 patients who underwent repeated MUA after failure of initial MUA for stiff TKA. Demographic and ROM data were collected. A final ROM of less than 90° was considered a failed manipulation (failure group) and a final ROM of 90° or more was considered a successful manipulation (success group). Average pre-repeated MUA ROM (72.3°±19.5°) immediately improved to 112.3°±9.7° (P<.001) in the operating room, and final ROM was 89.6°±23.9°, an overall gain of 17.3° (P=.04). However, despite this overall ROM increase, a successful final ROM (90° or more) was achieved in approximately half of patients (7 of 13; 54%). There were no significant differences in demographics between the success and failure groups, except that there was significantly less pre-TKA ROM in the failure group (P=.02). There were no complications related to either the first or the repeated MUA procedures. The findings of this study suggest that repeated MUA can improve overall ROM for stiff TKA. The success rate of repeated MUA was less than that of primary MUA; however, it is a useful treatment modality for stiff TKA. Decreased pre-TKA ROM appeared to be associated with poor outcomes after repeated MUA. [Orthopedics. 2015; 38(3):e157-e162.]. Copyright 2015, SLACK Incorporated.
    Full-text · Article · Mar 2015 · Orthopedics
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    ABSTRACT: Purpose: To evaluate how often manipulation under anesthesia (MUA) can achieve functional flexion ≥ 90 degrees and identify predictor for successful outcome of MUA for stiff total knee arthroplasty (TKA). Methods: Demographic data, range of motion, and surgical and anesthetic information of 143 MUAs were retrospectively analyzed from 2000 to 2011. Results: One-hundred thirty-six out of 143 patients (95 %) improved mean range of motion (ROM) from pre-MUA 62 ± 17° to final ROM 101 ± 21° (p < 0.001). Flexion ≥ 90 degrees was achieved in 74% (106/143) of patients. Regional anesthesia was identified as predictor of successful MUA outcome (p = 0.007, OR: 8.5, 95% CI: 1.2-66.7). Conclusions: Although the proportion of patients regaining flexion ≥ 90 degrees following MUA was less than those patients with simple overall ROM increase, the functional flexion ≥ 90 degrees was achieved in the vast majority of patients with stiff TKA following MUA.
    No preview · Article · Jul 2014 · International Orthopaedics
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    ABSTRACT: The two-stage exchange algorithm is the gold standard for managing chronic periprosthetic joint infection (PJI); this study evaluated the impact of having the stages performed at different institutions. Patients with a chronically infected total joint arthroplasty (hip or knee) with initial resection at an outside hospital and subsequent care at our institution (transferred group) were identified then matched with a similar cohort that received both stages at our institution (continuous group). Eighteen patients (transferred group) were compared to 36 matched controls. There were significantly lower rates of successful reimplantation and retention, longer duration of treatment and more procedures in the transferred group compared to the continuous group. Patients transferred during their care for chronic PJI underwent more surgeries, longer treatment times, and less favorable outcomes.
    No preview · Article · Jan 2014 · The Journal of arthroplasty
  • Ho-Rim Choi · Hany Bedair
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    ABSTRACT: We report the medium-term mortality after septic versus aseptic revision total knee arthroplasty (TKA) and factors that can contribute to mortality in revision TKA. Mortality rates of 88 patients undergoing septic revision (septic group) were compared with age- and year of surgery-matched 88 patients of aseptic revision (aseptic group). The overall mortality after revision TKA was 10.7% at a median of 4years of follow-up (range, 2-7years). However, the mortality after septic revision (18%, 16/88) was six times higher than that of aseptic revision (3%, 3/88) (P=0.003). Infections with Staphylococcus aureus and/or methicillin resistance was not associated with higher mortality rates. Multivariate analysis indicated that increased age (P<0.001), higher ASA class (P=0.002), and septic revision (P<0.001) were identified as independent predictors of increased mortality after revision TKA.
    No preview · Article · Dec 2013 · The Journal of arthroplasty
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    ABSTRACT: Eighty three patients of infected total hip arthroplasty (THA) treated by implant removal and staged revision were retrospectively analyzed. Clinical characteristics and treatment outcomes were compared between three groups: 17 one-stage revisions (one-stage group), 44 two-stage revisions with second stage reimplantation (two-stage reimplanted group), and 22 planned two-stage but no reimplantation (two-stage non-reimplanted group). The rate of infection control was 82% (14/17) in the one-stage group, 75% (33/44) in the two-stage reimplanted group, and 68% (15/22) in the two-stage non-reimplanted group (P=0.60). The mean of latest Harris hip score was 77, 60, and 58 (P=0.14), and the UCLA activity score was 4.0, 4.2, and 3.6 (P=0.74) for each group, respectively. Results of this study suggest that one-stage revision arthroplasty can be a treatment option in selected cases of infected THA with a satisfactory infection control rate and functional outcomes comparable to those of two-stage revision.
    No preview · Article · Aug 2013 · The Journal of arthroplasty
  • Ho-Rim Choi · Benjamin Beecher · Hany Bedair
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    ABSTRACT: Mortality rates after revision total hip arthroplasty (THA) for periprosthetic sepsis were investigated in 93 patients and compared to 93 patients, matched for age, gender, year of surgery, who underwent revision for aseptic failures. The mortality rate was 33% (31/93) in the septic group and 22% (20/93) in the aseptic group at 5 and 6year follow-up, respectively (P=0.10). Patients in the septic group died on average 6years earlier (74 versus 80yrs; P<0.05) than those in the aseptic group. Charlson Comorbidity Index (CCI) was an independent predictor of mortality among the both groups (P<0.05), while age (P<0.01) was a predictor of mortality only in the aseptic group. While revision THA for sepsis alone did not predict increased mortality, a 33% mortality rate at five years in patients with an average age of 66years and earlier death by 6years compared to aseptic revisions is alarming.
    No preview · Article · Aug 2013 · The Journal of arthroplasty
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    ABSTRACT: Eighteen patients with periprosthetic joint infection (11 hips and 7 knees) treated by prosthetic articulating spacers retained their spacers and were followed up at an average of 43.8months(range, 13-78months). Fifteen patients maintained well-functioning spacers for an average of 42.7months, of which 4 patients died with the spacers in situ at an average of 48.7months. The mean Harris Hip Score and Knee Society knee and function scores of survivors were 92, 92, 88, respectively. Spacers were revised in 3 patients because of recurrent infection (n=1) at 24months and mechanical loosening (n=2) at 74 and 50months. Findings of this study suggest that a proportion of patients with unplanned retention of prosthetic spacers appear to function well up to 6years without necessarily requiring further surgical intervention.
    No preview · Article · Aug 2013 · The Journal of arthroplasty
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    ABSTRACT: This study evaluates acetabular cup position in the setting of revision total hip arthroplasty (THA) with severe acetabular bone defects. With a definition of safe zone of abduction (30-50°) and anteversion (5-25°), acetabular cup position was measured by a digital image analysis program for 34 patients with Paprosky type III acetabular bone defects. There were 24 cups (71 %) for abduction and 26 cups (76 %) for anteversion located in the safe zone. Nineteen cups (56 %) were within the safe zone for both abduction and anteversion. There was no dislocation, however one cup out of the safe zone resulted in early cup failure due to aseptic loosening. The acetabular cup positioning in patients with Paprosky type III defects was 'optimal' in half of the cases. The prevalence of optimal acetabular cup position was similar to those reported in primary THA, suggesting that the presence of a large acetabular bone defect may not be a significant risk factor for suboptimal acetabular cup positioning in the setting of revision THA.
    No preview · Article · Jul 2013 · International Orthopaedics
  • Ho-Rim Choi · Young-Min Kwon

    No preview · Article · Jun 2013 · Journal of Orthopaedic Science
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    ABSTRACT: Negative culture result is frequently encountered in periprosthetic joint infection, but its clinical feature has not been well studied. In this study, clinical characteristics and treatment outcome were compared in two patient groups: (1) 40 periprosthetic joint infections with negative culture results (culture-negative group) and (2) 135 patients with positive culture results (culture-positive group). In comparison of two groups, the culture-negative group showed significantly higher incidence of prior antibiotic use (p=0.005), higher incidence of prior resection surgery (p<0.001) and lower ESR (p=0.02) than the culture-positive group. The success rate of infection control was higher in the culture-negative group (p=0.006), which suggests that culture negativity may not necessarily be a negative prognostic factor for periprosthetic joint infection.
    No preview · Article · Mar 2013 · The Journal of arthroplasty
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    ABSTRACT: Thirteen patients with infected total knee arthroplasty treated by 2-stage revision requiring tibial tubercle osteotomy in both stages for extensile exposure were retrospectively analyzed. The preoperative mean range of knee motion improved from 60° (range, 30°-90°) to 94° (range, 70°-120°) at latest follow-up. The Knee Society knee scores and function scores were 39 and 18 preoperatively and 78 and 67 at latest follow-up, respectively. Although proximal migration occurred in 3 cases and a partial proximal avulsion fracture of the osteotomy segment occurred in 1 case after the second-stage reimplantation, radiographic bony union was observed in all cases. Sequential repeated tibial tubercle osteotomy can be a useful extensile surgical approach in staged revision for infected total knee arthroplasty with satisfactory clinical and radiographic outcomes.
    No preview · Article · May 2012 · The Journal of arthroplasty
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    ABSTRACT: This study reports radiographic and clinical treatment outcomes of tibial tubercle osteotomy (TTO) used for two-stage revision total knee arthroplasty (TKA) in the setting of periprosthetic infection. Thirty-six patients with 51 TTOs used for infected TKA were retrospectively analysed from 2000 to 2010. In 15 of 36 patients, TTO was used in a sequential manner during both first and second stage procedures. The mean follow-up period was 57 months (range seven-126 months). The mean pre-operative range of knee motion was 40° (range 10-90°), and at latest follow-up it was 92° (range 50-140°). The Knee Society knee scores and function scores were 47 and 9 pre-operatively and 82 and 72 at latest follow-up, respectively. Bony union was achieved in all cases except one nonunion of an avulsion fragment of the osteotomy segment without functional deterioration. TTO can be a useful extensile surgical approach for treatment of infected TKA with satisfactory clinical and radiographic outcomes.
    No preview · Article · May 2012 · International Orthopaedics
  • Ho-Rim Choi · Henrik Malchau · Hany Bedair
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    ABSTRACT: This retrospective study compares treatment results of infected total knee arthroplasty with 2-stage exchange technique using 14 articulating spacers using metallic and polyethylene components (prosthetic group) and 33 static all-cement spacer (static group). For the prosthetic and static groups, treatment success rate was 71% and 67% at 58 months of follow-up, respectively, and not significantly different. The prosthetic group required less frequent extensile surgical approaches at the second-stage reimplantation. Range of motion was significantly improved in both groups, but there was no difference at latest follow-up between the groups. Of 14 in the prosthetic group, 4 (28%) did not undergo second-stage procedure. Antibiotic spacers consisting of prosthetic components can be a safe and effective treatment option for 2-stage revision total knee arthroplasty with equivalent infection control rates.
    No preview · Article · Apr 2012 · The Journal of arthroplasty
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    ABSTRACT: The purpose of this study was to compare infection control rates between implant retention and two-stage revision and assess the effectiveness of retention treatment in THA. Twenty-eight debridements with implant retention (retention group) and 65 staged revisions (removal group) were retrospectively analysed and risk factors that can contribute to failure of infection control were explored. For the retention and removal groups, infection control rates were 50% and 78% after initial treatment, and 68% and 82% at latest follow-up, respectively. There were no significant differences in the number of additional operative procedures, total length of hospital stay, and duration of treatment between groups. Infection of revision THA, polybacterial and S. aureus infection were identified as risk factors for infection control. Retention treatment can be considered an initial treatment option in selected cases of primary THA, with a single organism, non-S. aureus infection with 50% chance of infection control and no disadvantages in terms of additional procedure, hospital stay, and treatment duration.
    Full-text · Article · Jul 2011 · International Orthopaedics
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    ABSTRACT: Retention treatment is reportedly associated with lower infection control rates than two-stage revision. However, the studies on which this presumption are based depend on comparisons of historical rather than concurrent controls. We (1) asked whether the infection control rates, number of additional procedures, length of hospital stay, and treatment duration differed between implant retention and two-stage revision treatment; and (2) identified risk factors that can contribute to failure of infection control. We reviewed the records of 60 patients treated for 64 infected TKA from 2002 to 2007. Twenty-eight patients (32 knees) underwent débridement with retention of component, and 32 patients (32 knees) were treated with component removal and two-stage revision surgery. We determined patients' demographics, type of infection, causative organisms, and outcome of treatment. Mean followup was 36 months (range, 12-84 months). Infection control rate was 31% in retention and 59% in the removal group after initial surgical treatment, and 81% and 91% at latest followup, respectively. Treatment duration was shorter in the retention group and there was no difference in number of additional surgeries and length of hospital stay. Type of treatment (retention versus removal) was the only factor associated with infection control; subgroup analysis in the retention group showed Staphylococcus aureus infection and polyethylene nonexchange as contributing factors for failure of infection control. Although initial infection control rate was substantially lower in the retention group than the removal group, final results were comparable at latest followup. We believe retention treatment can be selectively considered for non-S. aureus infection, and when applied in selected patients, polyethylene exchange should be performed. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
    Full-text · Article · Nov 2010 · Clinical Orthopaedics and Related Research

Publication Stats

125 Citations
37.20 Total Impact Points


  • 2011-2015
    • Massachusetts General Hospital
      • • Harris Orthopaedics Lab
      • • Department of Orthopaedic Surgery
      Boston, Massachusetts, United States
  • 2010-2014
    • Harvard University
      Cambridge, Massachusetts, United States