Reysner T, Ciftci B, Alver S
… +3 more, Wieczorowska-Tobis K, Neumann-Podczaska A, Reysner M
Clin Orthop Relat Res
· 2026 Jun · PMID 42246693
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BACKGROUND: Postoperative pain after lumbar spine surgery often requires substantial opioid use. Perineural adjuvants such as dexamethasone and dexmedetomidine are increasingly used to prolong the duration of regional bl...BACKGROUND: Postoperative pain after lumbar spine surgery often requires substantial opioid use. Perineural adjuvants such as dexamethasone and dexmedetomidine are increasingly used to prolong the duration of regional blocks and improve analgesic quality; however, their comparative effects remain uncertain. Ultrasound-guided erector spinae plane block (ESPB) is widely used as part of multimodal analgesia, but the selection of perineural adjuvants remains uncertain. QUESTIONS/PURPOSES: (1) Does adding adjuvants (dexamethasone or dexmedetomidine) to the ESPB result in longer time to first rescue opioid? (2) Do patients who received adjuvants have lower total opioid consumption in the first 48 hours after surgery, and do they have lower pain scores? (3) Does dexamethasone or dexmedetomidine result in lower postoperative systemic inflammatory indices? METHODS: This study was conducted at a tertiary academic referral center specializing in spine surgery. In this prospective, randomized, triple-blinded controlled trial, between March 2024 and December 2025, a total of 103 patients were assessed for eligibility. Of these, 94 were randomized. Four patients were excluded after randomization because of intraoperative changes in surgical plan or hemodynamic instability, leaving 96% (90) of adult patients undergoing posterior lumbar decompression with instrumented fusion. These patients were randomly assigned to receive ESPB in three groups: the ropivacaine alone (control), the ropivacaine plus dexamethasone, and the ropivacaine plus dexmedetomidine groups. The primary outcome was time to first rescue opioid administration. Secondary outcomes included cumulative opioid consumption within 48 hours, postoperative pain scores, and systemic inflammatory markers (neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and systemic immune-inflammation index). Patients were followed for 48 hours postoperatively. RESULTS: Patients receiving dexamethasone or dexmedetomidine required rescue opioids later than those receiving ropivacaine alone. The mean ± SD time to first opioid administration was 6.2 ± 0.8 hours with ropivacaine alone versus 12.7 ± 2.7 hours with dexamethasone (mean difference 6.6 hours [95% confidence interval (CI) 5.6 to 7.7]; p < 0.001) and 15.5 ± 2.0 hours with dexmedetomidine (mean difference 9.6 hours [95% CI 8.5 to 10.5]; p < 0.001). Postoperative pain scores were reduced in both adjuvant groups at all assessed time points. Compared with dexmedetomidine and ropivacaine alone, dexamethasone was associated with lower postoperative systemic inflammatory indices, indicating greater attenuation of the inflammatory response. CONCLUSION: Dexamethasone and dexmedetomidine demonstrate distinct and complementary effects when used as adjuvants to ESPB in lumbar spine surgery. Dexmedetomidine primarily enhances early postoperative analgesia, whereas dexamethasone more effectively reduces cumulative opioid consumption and systemic inflammation. These findings support a clinically actionable, mechanism-informed approach to selecting ESPB adjuvants according to the desired temporal analgesic profile and risk of prolonged postoperative opioid requirement. LEVEL OF EVIDENCE: Level I, therapeutic study.
Yamada T, Yamato Y, Hasegawa T
… +9 more, Yoshida G, Banno T, Arima H, Oe S, Ushirozako H, Ide K, Kurosu K, Nurakami Y, Matsuyama Y
Clin Orthop Relat Res
· 2026 Jun · PMID 42241679
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BACKGROUND: Mechanical complications remain a major concern after adult spinal deformity surgery. Diabetes has been associated with impaired bone quality and delayed healing in orthopaedic surgery, but its relationship w...BACKGROUND: Mechanical complications remain a major concern after adult spinal deformity surgery. Diabetes has been associated with impaired bone quality and delayed healing in orthopaedic surgery, but its relationship with mechanical complications and patient-reported outcomes after adult spinal deformity surgery remains incompletely understood. QUESTIONS/PURPOSES: (1) Is diabetes associated with a higher odds of mechanical complications after adult spinal deformity surgery? (2) Is revision-free survivorship for proximal junctional failure lower in patients with diabetes than in those without diabetes? (3) Do radiographic alignment parameters differ between groups after surgery? (4) Are patient-reported outcomes lower in patients with diabetes at 2 years? METHODS: Between January 2010 and December 2023, a total of 585 patients underwent corrective fusion for adult spinal deformity at our institution. Of these, 11% (65) had diabetes and 89% (520) did not. Among patients with diabetes, none died before 2 years, but 3% (2 of 65) were lost to follow-up for reasons other than death. Among patients without diabetes, 0.6% (3 of 520) died, and 4% (23) were lost to follow-up before 2 years. This analysis therefore consisted of 557 patients, of whom 11% (63) had diabetes and 89% (494) did not; their data were analyzed at least 2 years after the index fusion. Diabetes was defined as a documented diagnosis being treated with medical therapy or hemoglobin A1c of at least 6.5%. Patients with diabetes were propensity score matched 1:2 with patients without diabetes based on age, gender, BMI, bone mineral density, deformity characteristics, osteotomy, pelvic fixation, and number of fused levels. The purpose of propensity matching was to improve comparability between groups by adjusting for measured baseline covariates rather than to establish causal inference. Proximal junctional failure was defined as structural failure at the upper instrumented vertebra or adjacent segment, accompanied by concordant symptoms and subsequent revision surgery. We compared the matched groups of patients with and without diabetes in terms of mechanical complications, revision-free survivorship using Kaplan-Meier analysis, postoperative alignment parameters on standing full-length AP and lateral radiographs, and patient-reported outcome scores (Oswestry Disability Index [ODI] and Scoliosis Research Society-22 [SRS-22] scores). For patient-reported outcomes, we focused on whether between-group differences exceeded prespecified minimum clinically important differences (MCIDs). RESULTS: Patients with diabetes had a higher odds of proximal junctional failure compared with patients without diabetes (19% [12 of 63] versus 9% [11 of 126], OR 2.5 [95% confidence interval (CI) 1.02 to 5.9]; p = 0.04). Revision-free survivorship for proximal junctional failure at 2 years was lower in patients with diabetes than in those without it (85% [95% CI 83% to 97%] versus 93% [95% CI 93% to 99%]; p = 0.02). We found no difference between groups in most radiographic alignment parameters at 1 and 2 years after surgery. Sagittal vertical axis was greater at the first standing radiograph in patients with diabetes than in those without it (mean ± SD 71 ± 53 mm versus 54 ± 49 mm, mean difference 17 [95% CI 1 to 33]; p = 0.04). Although patient-reported outcomes improved in both groups, none of the between-group differences exceeded reasonable MCID thresholds for the ODI or SRS-22 domains. CONCLUSION: Patients with diabetes undergoing corrective fusion for adult spinal deformity had a higher odds of proximal junctional failure and lower revision-free survivorship. Surgeons may consider discussing the possibility of junctional complications when counseling patients with diabetes and may consider closer postoperative surveillance and improvement of metabolic control in this population. Future studies should examine how glycemic control and bone quality influence junctional complications after deformity correction. LEVEL OF EVIDENCE: Level Ⅲ, therapeutic study.
Parthasarathi A, Setoguchi S, DeConti DK
… +7 more, Kupchak P, Donnelly P, Kardos K, McLaren AC, Fillingham YA, Levine BR, Deirmengian C
Clin Orthop Relat Res
· 2026 Jun · PMID 42233696
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BACKGROUND: The Unified Periprosthetic Joint Infection (PJI) Criteria were developed and endorsed by the European Society of Clinical Microbiology and Infectious Diseases, the European Bone and Joint Infection Society, t...BACKGROUND: The Unified Periprosthetic Joint Infection (PJI) Criteria were developed and endorsed by the European Society of Clinical Microbiology and Infectious Diseases, the European Bone and Joint Infection Society, the Infectious Diseases Society of America, and the Musculoskeletal Infection Society and formally presented at the 2025 International Consensus Meeting. These criteria recommended that synovial fluid white blood cells (WBC) > 3000 cells/µL or polymorphonuclear cells (PMN) > 75% each should be considered individually sufficient to confirm a diagnosis of PJI as standalone rule-in tests, stating specificity of > 95%. These thresholds and performance align with a 2025 meta-analysis published on behalf of the Unified PJI Definition Task Force, reporting specificities of 98.5% and 97.8%, respectively. Because such near-perfect specificities conflict with prior meta-analyses and known causes of false-positive leukocyte testing, independent validation of the supporting evidence is warranted. QUESTIONS/PURPOSES: (1) Is the 2025 meta-analysis published on behalf of the Unified PJI Definition Task Force methodologically rigorous and reproducible under independent appraisal and audit? (2) Do WBC count and PMN percentage demonstrate sufficient and generalizable rule-in performance for PJI? METHODS: An independent consortium with expertise in PJI diagnostics, epidemiology, and biostatistics conducted a formal methodological reappraisal of the 2025 meta-analysis. To address the first study question, the 2025 meta-analysis, all 74 primary studies, and the original source data files provided by that study's authors were assessed. After reproducing the original results of the 2025 meta-analysis to confirm understanding of data files and workflow, two independent reviewers used A Measurement Tool to Assess Systematic Reviews (AMSTAR-2) to assess quality, and then a methodological audit was performed using the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. Limitations were graded by consensus as critical, major, or minor, with critical limitations independently verified by three statisticians and two clinicians. To address our second study question, a reanalysis of the same corpus of 74 studies was performed using a hierarchical bivariate random-effects model, restricted to studies with predetermined thresholds. A standalone rule-in test is one in which a positive result alone is sufficient to establish the diagnosis of PJI, and its performance is most appropriately assessed using positive predictive value (PPV), which directly reflects the probability that a positive result represents true PJI. Sufficient rule-in performance was pragmatically defined as a PPV of > 90% across clinically plausible prevalence rates. Sufficiently generalizable performance was defined as demonstrable consistency across institutions, assessed through between-study heterogeneity of specificity. RESULTS: For the first study question, AMSTAR-2 assessment rated the 2025 meta-analysis as critically low overall confidence, reflecting weaknesses in multiple domains. Three critical limitations were identified during audit: (1) a data integrity discrepancy in the software input table used for the 2025 meta-analysis, in which false-positive counts were placed in the false-negative column and false-negative counts were placed in the false-positive column for all studies, rendering downstream results unreliable; (2) an outcome-dependent (self-fulfilling) threshold-selection approach that included only studies already reporting > 95% sensitivity or specificity, yielding results that were mathematically constrained to meet the 95% performance criteria, followed by derivation of thresholds using unweighted medians rather than meta-analytic techniques; and (3) presentation of pooled estimates and clinical threshold recommendations despite acknowledgment of markedly high heterogeneity (I2 statistic 88.3% to 99.3%). Major limitations included unit-of-analysis errors, use of specificity alone (rather than PPV) to define rule-in performance, unaddressed incorporation bias, and reliance on data-driven (Youden index) threshold selection. Regarding our second study question, in a reanalysis of the same 74 source studies, we found that WBC count and PMN percentage did not demonstrate sufficient or generalizable rule-in performance for PJI. Specifically, the heterogeneity for specificity remained high (I2 = 85% for WBC and I2 = 93% for PMN), reflecting considerable between-study variability. Summary specificity was 90% (95% confidence interval [CI] 86% to 92%) for WBC and 92% (95% CI 87% to 96%) for PMN. Resulting PPVs were low across clinically plausible disease prevalence rates, with point estimates of 67% (95% CI 61% to 74%) and 73% (95% CI 63% to 87%), respectively, at 20% PJI prevalence. CONCLUSION: Critical data integrity discrepancies and methodological limitations substantially undermine the reliability of the 2025 meta-analysis published on behalf of the Unified PJI Definition Task Force. Reanalysis of the same evidence base using recommended meta-analytic methods characterizes WBC count and PMN percentage as poor standalone rule-in tests for PJI for two main reasons: (1) the high heterogeneity of specificity for both WBC count and PMN percentage undermines the generalizability of these tests across institutions and precludes the establishment of universal thresholds, and (2) PPVs at clinically reasonable prevalence rates were low (67% to 73%) for standalone rule-in test usage, meaning that roughly 1 in 3 positive results would likely be a false-positive. CLINICAL RELEVANCE: We recommend that surgeons not use synovial fluid WBC count or PMN percentage thresholds as standalone rule-in criteria for PJI. Instead, these tests should be interpreted as supportive findings within a multimodal diagnostic framework, particularly when results are discordant with clinical findings, cultures, histology, serum markers, or other synovial tests. Professional organizations and regulatory bodies should reconsider recommending WBC count or PMN percentage as standalone rule-in tests for PJI until methodologically robust evidence demonstrates reproducible thresholds with sufficiently high PPVs.
Kirchner GJ, Riley C, Jimenez E
… +2 more, Stambough JB, Nikkel LE
Clin Orthop Relat Res
· 2026 Jun · PMID 42233625
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BACKGROUND: Robot-assisted THA is becoming more common, and evidence suggests that robot assistance improves the accuracy of acetabular cup positioning. By means of reducing implant malpositioning, robot-assisted THA has...BACKGROUND: Robot-assisted THA is becoming more common, and evidence suggests that robot assistance improves the accuracy of acetabular cup positioning. By means of reducing implant malpositioning, robot-assisted THA has been proposed as a method to reduce the risk of revision surgery and particularly revision due to dislocation. However, this has not yet been explored using an arthroplasty registry. QUESTIONS/PURPOSES: (1) In a dataset drawn from the American Joint Replacement Registry (AJRR) and its Medicare claims data linkage, after controlling for confounding variables, is robot-assisted THA associated with a decreased risk of all-cause revision at minimum 2-year follow-up? (2) After controlling for confounding variables, is robot-assisted THA associated with a decreased risk of revision for dislocation at minimum 2-year follow-up? METHODS: The AJRR and its Medicare claims data linkage were used to create a retrospective comparative study of patients aged 65 years or older who underwent primary elective robot-assisted THA (n = 113,477) or conventional THA (n = 10,988) between 2017 and 2021. All patients within the AJRR who had undergone primary THA and had complete records with respect to robot data were included. The AJRR was selected for this study because of its Medicare linkage, and therefore follow-up data are considered near complete. Both cohorts had the same mean age (74 ± 6 years; p = 0.15) and the same proportion of females (60% [67,903 of 113,447] for conventional THA versus 60% [6540 of 10,988] for robot-assisted THA; p = 0.51). Mixed-effect Cox regression models were used to determine the hazard of all-cause revision and revision for dislocation at 2 years. Variables included within these models were age, Charlson comorbidity index (CCI), length of stay (LOS), sex, anesthesia type, and race. Surgeon and institution were controlled as the random effect within these models. RESULTS: After controlling for confounding variables, the risk of all-cause revision at 2 years did not differ between robot-assisted THA and conventional THA (1.9% [208 of 10,988] versus 2.1% [2357 of 113,477], HR 0.9 [95% confidence interval (CI) 0.7 to 1.1]; p = 0.42). Revision for dislocation was lower in robot-assisted THA (0.3% [35 of 10,988]) compared to conventional THA (0.6% (689 of 113,477), HR 0.5 [95% CI 0.3 to 0.9]; p = 0.03). CONCLUSION: Robot-assisted THA did not demonstrate a difference in all-cause revision at 2 years, but robot-assisted THA was associated with a reduced risk of revision for dislocation compared to conventional THA. This study demonstrates that robotic assistance is a potentially useful adjunct during THA to decrease the risk of early revision for dislocation. In clinical scenarios where early dislocation might be a concern, robot-assisted THA might be considered a means to mitigate this risk. However, until or unless robot assistance demonstrates clear improvement regarding revision-free implant survival, surgeons should remain cautious of widespread adoption of this technology. LEVEL OF EVIDENCE: Level III, therapeutic study.
Catley CD, Payne ER, Ballatori SE
… +4 more, Pangelinan J, Chen L, O'Keefe R, Cahill SV
Clin Orthop Relat Res
· 2026 Jun · PMID 42223149
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BACKGROUND: Lesbian, gay, bisexual, transgender, and queer (LGBTQ+) patients often face barriers to trust in healthcare settings because of historical and ongoing discrimination. In orthopaedic surgery-a specialty someti...BACKGROUND: Lesbian, gay, bisexual, transgender, and queer (LGBTQ+) patients often face barriers to trust in healthcare settings because of historical and ongoing discrimination. In orthopaedic surgery-a specialty sometimes perceived as less inclusive-visible symbols of allyship such as rainbow flags may influence patient perceptions, yet this remains unstudied. QUESTIONS/PURPOSES: (1) Is the display of LGBTQ+ allyship symbols (rainbow flags) associated with patient trust in an orthopaedic surgeon? (2) Which demographic factors are associated with positive or negative responses to these symbols? (3) What opinions do patients have regarding LGBTQ+ surgeons or displaying these symbols in an orthopaedic setting? METHODS: We conducted two randomized, blinded surveys; the first recruited from a tertiary urban and academic orthopaedic clinic (362 of 477 patients contacted) and the second cohort recruited nationally via the online Amazon Mechanical Turk (MTurk) platform (439 of 1258 patients contacted). Clinic participants had a mean ± SD age of 48 ± 17 years, with 62% (223) women, while online participants had a mean ± SD age of 45 ± 17 years, with 49% (215) women. Online participants were more frequently White, men, urban dwelling, and highly educated, with 82% (358 of 439) holding a bachelor's degree or higher. Prior reported experience with orthopaedic care was common in both groups: 77% (280 of 362) in-clinic, 69% (303 of 439) online. Participants viewed an image of a hypothetical orthopaedic surgeon presented as a Black man wearing a white coat either with a rainbow pride lapel pin or without a pin; they then completed the Trust in Physician Scale (TIPS), a previously validated measure of patient trust, with higher scores indicating more trust (range 0 to 100). Scores were then compared between the group that viewed the image with the pin and the group that viewed the image without a pin using a minimum clinically important difference of 14 points. Participants were blinded to the purpose of the study and could not go back to change the TIPS scores. Demographic factors including US Census region, urban versus rural location, age, race or ethnicity, education, income, degree of religiousness, political ideology, reported gender, and sexual orientation were assessed for association with position toward allyship symbols. Explicit attitudes toward LGBTQ+ allyship symbols and LGBTQ+ surgeons were then assessed via direct questioning using a 10-point Likert scale (10 indicating more positive response) and ordinal categorical responses about hypothetical surgeons or scenarios. Free response answers were also collected and qualitatively categorized. RESULTS: Among all responders, we found no important difference in trustworthiness between surgeons wearing allyship symbols and those not wearing them in clinic (mean ± SD 76 ± 16 versus 71 ± 15, mean difference 5 [95% confidence interval (CI) -8 to -1]; p = 0.005) and online (64 ± 13 versus 64 ± 13, mean difference 0.7 [95% CI -2 to 3]; p = 0.6). Democrat-leaning participants reported higher trust in both cohorts (in clinic: OR 10.00 [95% CI 5.56 to 20.00]; p < 0.001 and online: OR 3.45 [95% CI 2.33 to 5.00]; p < 0.001), with women and less religious individuals in the clinic cohort showing greater trust (OR 2.27 [95% CI 1.52 to 3.45]; p < 0.001 and OR 1.80 [95% CI 1.18 to 2.75]; p = 0.006, respectively) and nonheterosexual participants in the online cohort (OR 2.43 [95% CI 1.56 to 3.85]; p < 0.001). Conversely, Republican-leaning participants in both groups reported lower trust (in clinic: OR 0.1 [95% CI 0.05 to 0.18]; p < 0.001 and online: OR 0.29 [95% CI 0.20 to 0.43]; p < 0.001), with lower positivity among men and more religious clinic participants (OR 0.44 [95% CI 0.29 to 0.66]; p < 0.001 and OR 0.56 [95% CI 0.36 to 0.85]; p = 0.006, respectively) and among heterosexual respondents online (OR 0.41 [95% CI 0.26 to 0.64]; p < 0.001). When asked, most respondents expressed neutral or positive views toward LGBTQ+ symbols: rainbow pins (clinic group versus online group 6 ± 3 versus 7 ± 3, mean difference 0.3 [95% CI -0.07 to 0.7]; p = 0.1) and flags (6 ± 3 versus 6 ± 3, mean difference 0.3 [95% CI -0.01 to 0.8]; p = 0.06). Confidence in the surgical skills of LGBTQ+ surgeons was high across cohorts (> 90% in both groups). A minority reported that they would be more likely to switch surgeons (clinic 12% [41 of 350], online 11% [50 of 439]) or less likely (clinic 11% [38 of 350], online 28% [124 of 439]). Free responses were largely neutral, with a number of patients responding to individual displays of allyship positively, while institutional displays were interpreted as unprofessional. Respondents emphasized the importance of surgical skills above all. Mean differences within this paragraph appear incorrect due to rounding of means ± SDs. CONCLUSION: We found no perceptible difference in the degree to which a surgeon would be trusted based on whether (s)he did or did not display LGBTQ+ allyship symbols. However, among some subgroups of patients, displaying these symbols was associated with greater or less trust. CLINICAL RELEVANCE: Displaying LGBTQ+ allyship symbols is unlikely to meaningfully shape trust in orthopaedic settings but may foster trust or distrust among certain patient populations. Individual surgeons should consider context and patient demographics when choosing whether to display such symbols, but they are unlikely to alienate most patients who prioritize surgical competence. Institutions may achieve greater benefit by prioritizing structural inclusion efforts-such as nondiscrimination policies, staff training, and outreach-rather than relying on symbolic displays.
Clin Orthop Relat Res
· 2026 Jun · PMID 42208061
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BACKGROUND: Hallux valgus is a common forefoot deformity that alters forefoot loading and often leads to secondary complications such as intractable plantar keratosis beneath the second metatarsal head. Although the link...BACKGROUND: Hallux valgus is a common forefoot deformity that alters forefoot loading and often leads to secondary complications such as intractable plantar keratosis beneath the second metatarsal head. Although the link between hallux valgus and intractable plantar keratosis is recognized, whether two procedures that correct intractable plantar keratosis through different mechanisms-minimally invasive chevron Akin osteotomy (MICA) with first metatarsal head lowering and conventional MICA combined with second distal metatarsal minimally invasive osteotomy (DMMO)-have differential effects on symptom improvement has not, to our knowledge, been assessed. QUESTIONS/PURPOSES: (1) Do patients with hallux valgus and intractable plantar keratosis beneath the second metatarsal head have distinctive radiographic features compared with those with hallux valgus alone? (2) How do the two different surgical strategies (MICA with first metatarsal head lowering versus MICA with second DMMO) differ in terms of lesser metatarsal head height and intractable plantar keratosis resolution? (3) What are the differences in the Foot and Ankle Ability Measure (FAAM), including the subscales for activities of daily living (ADL) and sports, and other complications between these techniques? METHODS: Between January 2017 and June 2024, two surgeons treated 194 feet with hallux valgus using MICA after predefined exclusions. Of these, 113 feet did not have preoperative intractable plantar keratosis beneath the second metatarsal head; after excluding 13 feet without a minimum 1-year follow-up, 100 feet were included as a reference cohort. The remaining 81 feet had preoperative intractable plantar keratosis beneath the second metatarsal head and constituted the primary study cohort. Within this group, 34 feet underwent MICA with first metatarsal head lowering and 47 feet underwent MICA with second DMMO. From 2017 to 2020, MICA with second DMMO was routinely used for patients with intractable plantar keratosis beneath the second metatarsal head. Beginning in 2021, we gradually incorporated first metatarsal head lowering, and both procedures were used thereafter based on first-ray sagittal alignment, intraoperative loading patterns, and patient preference. After excluding feet without a minimum 1-year follow-up, 30 feet in the MICA with first metatarsal head lowering group and 42 feet in the MICA with second DMMO group were available for comparative analysis. There was no differential loss to follow-up between study groups for analysis in this retrospective study (12% [4 of 34] and 11% [5 of 47]). Follow-up completeness was comparable between groups, with similar mean ± SD follow-up durations (15 ± 3 months versus 17 ± 4 months). The study population had a mean age of 57 years and was predominantly female (approximately 90%), with comparable demographic characteristics between groups. To answer our first study question, we compared preoperative radiographic characteristics-including hallux valgus angle, first-to-second intermetatarsal angle, and the relative length and height of the lesser metatarsals-between patients with and without intractable plantar keratosis beneath the second metatarsal head. To address our second study question, we evaluated the changes in the relative height of the lesser metatarsals and postoperative resolution of intractable plantar keratosis following two different techniques. To answer our third study question, we compared the FAAM-ADL and sports scores and procedure-related complications between the two surgical techniques. All p values were adjusted using the Holm-Bonferroni method. Because some patients contributed bilateral feet, analyses were adjusted for the nonindependence of observations using a mixed-effects model with patient as a random effect; within-patient correlation was negligible, supporting inclusion of both feet in the analysis. RESULTS: Patients with hallux valgus and intractable plantar keratosis beneath the second metatarsal head had a larger hallux valgus angle (mean ± SD 35° ± 8° versus 31° ± 8°, mean difference 4° [95% confidence interval (CI) 1° to 5°]; p < 0.001) and lower second (3 ± 2 mm versus 1 ± 2 mm, mean difference 2 mm [95% CI 1.5 to 2.7]; p < 0.001) and third metatarsal heads (4 ± 2 mm versus 2 ± 1 mm, mean difference 2 mm [95% CI 1.3 to 2.5]; p < 0.001) than those without intractable plantar keratosis. Both procedures resolved intractable plantar keratosis at similar percentages (87% [26 of 30] versus 91% [38 of 42], OR 0.7 [95% CI 0.2 to 3.0]; p = 0.71). However, MICA with first metatarsal head lowering elevated both the second (-2 mm [95% CI -4.2 to 0]) and third metatarsal heads (-2 mm [95% CI -3.8 to 0]), whereas MICA with second DMMO elevated the second (-2 mm [95% CI -4.7 to -0.1]) but lowered the third (1 mm [95% CI -0.4 to 2.4]), producing a between-group difference of 3 mm (95% CI 1.9 to 3.9; p < 0.001). Functional outcomes improved in both groups, but MICA with first metatarsal head lowering showed greater improvement in FAAM-sports scores (24% versus 21%, mean difference 3% [95% CI 2% to 7%]; p = 0.04). Postoperatively, MICA with second DMMO resulted in new intractable plantar keratosis beneath the third metatarsal head (10% [4 of 42]). In contrast, first metatarsal head lowering more frequently caused plantar discomfort beneath the first metatarsal head (17% [5 of 30]). CONCLUSION: Accurate assessment of metatarsal height in the axial plane is essential when surgically treating hallux valgus with intractable plantar keratosis. Although both adjunctive procedures-first metatarsal head lowering and second DMMO-effectively improved intractable plantar keratosis, they differ in their corrective mechanisms and associated risks: adding only second DMMO may predispose patients to new keratosis beneath the third metatarsal head, whereas lowering the first metatarsal head may result in postoperative plantar discomfort beneath the first metatarsal head. LEVEL OF EVIDENCE: Level III, therapeutic study.