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Alter, Thomas D.

https://orcid.org/0000-0003-2126-2766

Mayo Clinic

Mayo Clinic

Citations 7

Three Hundred Periprosthetic Tibial Fractures Around a Total Knee Replacement
Dugdale, Evan M. , Alter, Thomas D. , Stuart, Michael J. , Sems, S.A. , Yuan, Brandon J. , Spangehl, Mark J. , Springer, Bryan D. , Berry, Daniel J. , Abdel, Matthew P. , Sems, Stephen A , Abdel, Matthew P , Stuart, Michael J , Yuan, Brandon , Berry, Daniel J , Spangehl, Mark

Journal of Bone and Joint Surgery | May 23, 2025 | Volume: 107 | Issue: 14 | Pages: 1579-1589

10.2106/jbjs.24.01407 Get It

Background: Periprosthetic tibial fractures around a total knee replacement (TKR) remain challenging to manage, with little published information for guidance. The purpose of this study was to review the types, management techniques, and outcomes of periprosthetic tibial fractures in the largest series to date. Methods: We identified 300 periprosthetic tibial fractures (285 patients) around a TKR (43% in primary TKRs and 57% in revision TKRs) sustained between 1996 and 2020. Fractures were classified according to Felix et al. as Type I (tibial plateau), Type II (adjacent to stem), Type III (distal to stem), or Type IV (tibial tubercle), with subtypes A (well-fixed component), B (loose component), and C (intraoperative fracture). Of the fractures in this study, 53% were Type I, 24% were Type II, 16% were Type III, and 8% were Type IV. A total of 46% of fractures occurred intraoperatively, and 54% of fractures occurred postoperatively (61% subtype A, 39% subtype B). The mean patient age at fracture was 67 years, and 64% of patients were female. The mean follow-up was 6 years. Results: The intraoperative fracture incidence was 1.40% in revision TKRs and 0.10% in primary TKRs. Among intraoperative fractures, the 2-year survivorship free from tibial component revision was highest in Type I (100%) and lowest in Type IV (67%) (p < 0.001). For postoperative fractures, the 2-year survivorship free from any reoperation was 29% and the 2-year survivorship free from tibial component revision was 51%. Type-I postoperative fractures had the lowest 2-year survivorship free from tibial component revision (10%), whereas Type-III fractures had the highest survivorship (88%) (p < 0.001). Conclusions: Intraoperative periprosthetic fracture of the tibia was fourteenfold more likely in revision TKRs compared with primary TKRs. Among all intraoperative fractures, Type-I fractures were well-tolerated, with 100% survivorship free from tibial component revision at 2 years. Conversely, Type-I postoperative fractures had only 10% survivorship at 2 years. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.
EP4.7 Two-Year Minimum Outcomes of Arthroscopic Subchondroplasty for Acetabular Subchondral Cysts Demonstrates 62.1% Arthroplasty-Free Survivorship: Smaller Cyst Size Predicts Survivorship
Vogel, Michael , Alvero, Alexander , Cotter, Eric J. , Alter, Thomas D. , Nho, Shane, Cervantes, Jesus, Chapman, Reagan S. , Nho, Shane J. , Cervantes, Jesus

Journal of Hip Preservation Surgery | March 31, 2025 | Volume: 12 | Issue: Supplement_1 | Pages: i80-i81

10.1093/jhps/hnaf011.260 Get It

Abstract Background: Prior studies have evaluated the efficacy of subchondroplasty for the management of subchondral cysts of the knee, yet few studies to date evaluate minimum 2-year outcomes following subchondroplasty of the acetabulum. Purpose: The purpose of this study was to evaluate minimum two-year outcomes following arthroscopic subchondroplasty for the treatment of acetabular subchondral cysts and to identify variables associated with total hip arthroplasty (THA) conversion following subchondroplasty. Study Design: Cases Series, Level of Evidence IV. Methods: A retrospective review of prospectively maintained data was performed on patients who underwent primary hip arthroscopy May 2019 to September 2021 by a single surgeon. Consecutive patients who underwent subchondroplasty for acetabular subchondral cysts with minimum two-year follow-up were identified. Demographics, magnetic resonance imaging (MRI), intraoperative findings, and clinical outcomes were evaluated. Cross-sectional area of the subchondral cysts was measured on MRI. Clinical outcomes included Hip Outcome Score–Activities of Daily Living (HOS-ADL), HOS–Sports Subscale (HOS-SS), international Hip Outcome Score-12 (iHOT-12), and visual analog scale for pain (VAS-Pain). Conversion to THA was recorded. The patients who converted to THA were compared to those who did not. Continuous variables associated with THA conversion were analyzed with receiver operating characteristic (ROC) curves to identify thresholds associated with THA conversion. Results: Twenty-nine patients underwent subchondroplasty for acetabular subchondral cysts with minimum two-year follow up (age: 48.2±11.1 years, body mass index: 29.9±6.6kg/m2, 52.0% female). The THA-free survivorship rate was 62.1%. Patients who achieved THA-free survivorship had smaller subchondral cysts (88.5±59.2 mm2 vs. 147.1±54.8, P=0.013) and a lower prevalence of high-grade femoral head chondral defects (16.7% vs. 54.5%, P=0.048) compared to patients who converted to THA. ROC analysis identified patients with a subchondral cyst &lt;133 mm2 were 21.3 times more likely to achieve THA-free survivorship (P=0.001). The THA-free survivors demonstrated significant improvements across all measured PROs (P≤0.015). Conclusions: Subchondroplasty for acetabular subchondral cysts demonstrated a 62.1% THA-free survivorship at minimum 2-year follow-up, with survivors demonstrating significantly improved PROs. Patients with cysts &lt;133 mm2 were 21.3 times more likely to achieve THA-free survivorship than patients with larger cysts. Keywords: Hip, Acetabulum, Subchondral Cysts, Subchondroplasty
Risk of Subsequent Hip Fractures across Varying Treatment Patterns for Index Vertebral Compression Fractures
Ton, Andy , Bell, Jennifer A. , Karakash, William J. , Alter, Thomas D. , Erdman, Mary Kate , Kang, Hyunwoo P. , Ragheb, Jonathan , Athari, Mirbahador , Wang, Jeffrey C. , Athari, Mirbahador , Ton, Andy , Mills, Emily S. , Alluri, Ram Kiran , Hah, Raymond J.

Journal of Clinical Medicine | August 14, 2024 | Volume: 13 | Issue: 16 | Pages: 4781

10.3390/jcm13164781 Get It

Introduction: Vertebral compression fractures (VCFs) pose a considerable healthcare burden and are linked to elevated morbidity and mortality. Despite available anti-osteoporotic treatments (AOTs), guideline adherence is lacking. This study aims to evaluate subsequent hip fracture incidence after index VCF and to elucidate AOT prescribing patterns in VCF patients, further assessing the impact of surgical interventions on these patterns. Materials and Methods: Patients with index VCFs between 2010 and 2021 were identified using the PearlDiver database. Diagnostic and procedural data were recorded using International Classification of Diseases (ICD-9, ICD-10) and Current Procedural Terminology (CPT) codes. Patients under age 50 and follow-up <one year following index VCF were excluded. Patients were categorized based on whether they received AOT within one year, preceding and after index VCF, and were subsequently propensity-matched 1:3 based on age, sex, and Elixhauser Comorbidity Index (ECI) score to compare hip fracture incidence following index VCF. Sub-analysis was performed for operatively managed VCFs (kyphoplasty/vertebroplasty). Statistical tests included Chi-squared for categorical outcomes, and Kruskal–Wallis for continuous measures. Results: Of 637,701 patients, 72.6% were female. The overall subsequent hip fracture incidence was 2.6% at one year and 12.9% for all-time follow-up. Propensity-matched analysis indicated higher subsequent hip fracture rates in patients initiated on AOT post-index VCF (one year: 3.8% vs. 3.5%, p = 0.0013; all-time: 14.3% vs. 13.0%, p < 0.0001). Conclusions: The study reveals an unexpected increase in subsequent hip fractures among patients initiated on AOT post-index VCF, likely due to selection bias. These findings highlight the need for refined osteoporosis-management strategies to improve guideline adherence, thereby mitigating patient morbidity and mortality.
Effect of Differing Orientation and Magnitude of Femoral Torsion on Outcomes and Achievement of the MCID and PASS at 5 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome
Alter, Thomas D. , Fenn, Thomas W. , Rice, Morgan W. , Kaplan, Daniel James , Nho, Shane J.

The American Journal of Sports Medicine | June 29, 2023 | Volume: 51 | Issue: 10 | Pages: 2540-2550

10.1177/03635465231182151 Get It

Background: Femoral torsion measurements and outcomes are variable throughout the literature and have focused on short-term follow-up. However, there is a paucity of literature investigating clinically meaningful outcomes at midterm follow-up after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Purpose: To quantify femoral version using computed tomography imaging in patients with FAIS and to explore the relationship between version abnormalities and 5-year outcomes after hip arthroscopy. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent primary hip arthroscopy for FAIS between January 2012 and November 2017 were identified. Patients were included if they had 5-year follow-up with completion of ≥1 patient-reported outcome (PRO) scores and excluded if they had Tönnis grade >1, revision hip surgery, a concomitant hip procedure, a developmental disorder, or a lateral center-edge angle <20°. Torsion groups were defined as severe retrotorsion (<0°), moderate retrotorsion (0.1°-5°), normal torsion (5.1°-20°), moderate antetorsion (20.1°-25°), and severe antetorsion (>25.1°) based on computed tomography measurements. Patient characteristics were analyzed among the torsion cohorts, as were preoperative and 5-year PROs: Hip Outcome Score–Activities of Daily Living, Hip Outcome Score–Sports Subscale, modified Harris Hip Score, international Hip Outcome Tool, visual analog scale for pain, and visual analog scale for satisfaction. Achievement rates of cohort-specific thresholds for the minimal clinically important difference and Patient Acceptable Symptom State were calculated and compared among cohorts. Results: A total of 362 patients (244 female, 118 male; mean ± SD age, 33.1 ± 11.5 years; body mass index, 26.9 ± 17.8) met inclusion/exclusion criteria and were analyzed at a final mean follow-up of 64.3 ± 9.4 months (range, 53.5-115.5 months). Mean femoral torsion was 12.8°± 9.2°. The number of patients within each group was 20 for severe retrotorsion (torsion, −6.3°± 4.9°), 45 for moderate retrotorsion (2.7°± 1.3°), 219 for normal torsion (12.2°± 4.1°), 39 for moderate antetorsion (21.9°± 1.3°), and 39 for severe antetorsion (29.0°± 4.2°). No significant differences in age, body mass index, sex, smoking status, workers’ compensation, psychiatric history, back pain, or physical activity were found among the torsional groups. All groups demonstrated significant improvements at 5 years postoperatively ( P < .01 for all). All torsion subgroups demonstrated similar pre- to postoperative changes in PROs ( P≥ .515) and PRO values at 5-year follow-up ( P≥ .098). There were no significant differences in the achievement of the minimal clinically important difference ( P≥ .422) or Patient Acceptable Symptom State ( P≥ .161) for any of the PROs among the torsion groups. Conclusion: The orientation and severity of femoral torsion at the time of hip arthroscopy for FAIS in this study’s cohort did not affect the propensity for clinically meaningful outcome improvement at midterm follow-up.
Isolated, Full-Thickness Proximal Rectus Femoris Injury in Competitive Athletes: A Systematic Review of Injury Characteristics and Return to Play
Knapik, Derrick M. , Alter, Thomas D. , Ganapathy, Aravinda , Smith, Matthew V. , Matava, Matthew J. , Brophy, Robert H.

Orthopaedic Journal of Sports Medicine | January 23, 2023 | Volume: 11 | Issue: 1 | Pages: No page available

10.1177/23259671221144984 Get It

Background: Characteristics regarding mechanism of injury, management, and return-to-play (RTP) rate and timing are important when treating and counseling athletes with rectus femoris tears. Purpose: To systematically review the literature to better understand the prevalence, sporting activity, injury mechanisms, and treatment of patients with rectus femoris injury and to provide prognostic information regarding the rate and timing of RTP. Study Design: Systematic review; Level of evidence, 4. Methods: Following the 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we queried PubMed/MEDLINE, Cochrane, OVID, EMBASE, and Google Scholar in March 2022 for studies reporting on athletes sustaining isolated, full-thickness tearing, or bony avulsion injuries to the proximal rectus femoris during sporting activity. Excluded were studies without evidence of full-thickness tearing or avulsion, with athletes sustaining concomitant injuries, or with injuries occurring from nonsporting activities. The percentage of athletes sustaining injuries was calculated based on sport, injury mechanism, and management (nonoperative versus operative). Results: Of 132 studies initially identified, 18 were included, comprising 132 athletes (mean age, 24.0 ± 5.4 years; range, 12-43 years). The most common sporting activities were soccer (70.5%) and rugby (15.2%). The most reported mechanisms of injury were kicking (47.6%) and excessive knee flexion/forced hip extension (42.9%). Avulsion injuries were reported in 86% (n = 114) of athletes. Nonoperative management was reported in 19.7% of athletes, with operative management performed in 80.3%. The mean follow-up time was 21.4 ± 11.4 months (range, 1.5-48 months). The RTP rate was 93.3% (n = 14) in nonoperatively treated and 100% (n = 106) in operatively treated athletes, and the mean RTP time was 11.7 weeks (range, 5.5-15.2 weeks) in nonoperatively treated and 22.1 weeks (range, 14.0-37.6 weeks) in operatively treated athletes. Complications were reported in 7.7% (2/26) of nonoperatively treated and 18% (n = 19/106) of operatively treated athletes. Conclusion: Full-thickness proximal rectus femoris injuries occurred most frequently in athletes participating in soccer and rugby secondary to explosive, eccentric contractions involved in kicking and sprinting. Operative management was performed in the majority of cases. Athletes who underwent operative repair had a 100% RTP rate versus 93.3% in athletes treated nonoperatively.
Staged Bilateral Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Index Surgery Patient Reported Outcome Measures Predict Contralateral Surgery Results at 2 Years
Horner, Nolan S. , Rice, Morgan W. , Alter, Thomas D. , Ephron, Christopher G. , Nho, Shane J. , Alter, Thomas, Sivasundaram, Lakshmanan

Arthroscopy | December 8, 2022 | Volume: 39 | Issue: 5 | Pages: 1175

10.1016/j.arthro.2022.10.048 Get It

Purpose To determine whether (1) patient‐reported outcome (PRO) scores after index hip arthroscopy correlate with PRO scores for the contralateral hip in patients undergoing staged bilateral hip arthroscopy and (2) patients who achieved minimal clinically important difference (MCID) or patient‐acceptable symptom state (PASS) for the index hip were more likely to achieve MCID or PASS for the contralateral hip. Methods Patients who underwent staged bilateral hip arthroscopy for femoroacetabular impingement syndrome were retrospectively reviewed. PRO scores were prospectively collected at preoperative and 1‐ and 2‐year timepoints. Odds ratios for achievement of MCID and PASS for the contralateral hip given achievement for the index hip were calculated. Improvements from before surgery to 2 years after surgery were correlated between both hips. Results A total of 143 patients (286 hips) were included in the final analysis. Average time between surgeries was 8.5 months (range, 0.7‐57.2). Both hips demonstrated significant improvement ( P < .05 for all) in all PROs at 2 years. Achievement of MCID in Hip Outcome Score Activities of Daily Living (HOS‐ADL) at the 1‐year timepoint for the index hip was predictive of achievement of MCID in HOS‐ADL at 2 years for the contralateral hip. Achievement of PASS in all PROs at the 1‐year timepoint for the index hip were predictive of achievement of PASS in the equivalent outcome score at the 2‐year mark for the contralateral hip. Achievement of MCID or PASS at the 2‐year timepoint for the index hip was predictive of achievement of the equivalent outcome at the 2‐year timepoint for the contralateral hip. The strongest correlation between improvement in PRO scores for the index and contralateral hips was noted in patients who underwent staged hip arthroscopy within less than 3 months. Conclusion Patients experience significant clinical benefit in both hips after staged bilateral hip arthroscopy. Results from the initial hip arthroscopy at either 1‐ or 2‐year follow‐up can be used to predict outcomes on the contralateral side; however, there is a higher degree of predictive value using 2‐year results. Average correlations between 2‐year PROs on the index and contralateral hips were moderate to strong, regardless of the time between surgeries. Level of Evidence Level III, retrospective cohort study.
Outcomes for the Arthroscopic Treatment of Femoroacetabular Impingement Syndrome With Acetabular Retroversion: A 3D Computed Tomography Analysis
Alter, Thomas D. , Knapik, Derrick M. , Lambers, Floor M. , Sivasundaram, Lakshmanan , Malloy, Philip , Chahla, Jorge , Nho, Shane J.

The American Journal of Sports Medicine | May 23, 2022 | Volume: 50 | Issue: 8 | Pages: 2155-2164

10.1177/03635465221097118 Get It

Background: Increased attention has been directed toward the acetabular morphology in the management of patients with femoroacetabular impingement syndrome (FAIS). Whether acetabular version influences patient-reported outcomes remains poorly understood. Purpose: To use computed tomography (CT)–based 3-dimensional (3D) bone models to (1) quantify acetabular version in patients with FAIS, (2) compare acetabular version on 3D bone models with current plain radiographic parameters, and (3) explore the relationship between the magnitude of acetabular version and minimum 2-year clinical outcomes after hip arthroscopy. Study Design: Cohort study; Level of evidence, 3. Methods: Three-dimensional models of the pelvis and femur were generated by semiautomated segmentation and aligned to a standard coordinate system. Acetabular version was quantified at the 3-o’clock position, and 3 groups were identified: acetabular retroversion (AR; <15°), normal acetabular version (NV; 15°-25°), and acetabular anteversion (AA; >25°). Patient demographic characteristics, plain radiographic parameters, and clinical outcomes were analyzed, including the Hip Outcome Score–Activities of Daily Living, Hip Outcome Score–Sports Subscale, modified Harris Hip Score (mHHS), International Hip Outcome Tool (iHOT-12), and visual analog scale (VAS) for pain and satisfaction. Results: Preoperative CT scans were acquired in 105 consecutive patients before hip arthroscopy for FAIS, of which 84 (80.0%) completed minimum 2-year patient-reported outcomes. The mean ± SD age and body mass index of patients were 33.9 ± 12.6 years and 26.0 ± 5.4, respectively; 70.2% were female. The number of patients and the mean central acetabular version within each group were as follows: AR (n = 12; 11.3°± 2.7°), NV (n = 56; 20.7°± 2.9°), and AA (n = 16; 28.5°± 2.7°). Posterior wall sign was the only plain radiographic parameter that was significantly more observed in the AR group than in the other 2 groups. At minimum 2-year follow-up, significant between-group differences in the mHHS, iHOT-12, and VAS for pain and satisfaction ( P < .05) were appreciated, while post hoc analysis with Bonferroni correction ( P < .0167) found lower scores on the mHHS, iHOT-12, and VAS for pain and satisfaction in patients with AR as compared with NV. Lower scores on the VAS for satisfaction were reported in patients with AR when compared with AA ( P = .006) but not on the mHHS ( P = .023), iHOT-12 ( P = .032), or VAS for pain ( P = .072). Conclusion: Traditional plain radiographic indices to describe AR, including crossover sign and ischial spine sign, were not reliable in defining AR according to 3D models derived from CT scans. Only the posterior wall sign was observed in a higher proportion in the AR group. Patients with AR demonstrated inferior outcomes when compared with patients with NV and AA after hip arthroscopy for FAIS.