Preoperative Degenerative Changes at the Tibial Sesamoid-Metatarsal Joint in Hallux Valgus: Association With Postoperative Patient-Reported Outcomes After Modified Lapidus Procedure.

Background: Degenerative changes at the sesamoid-metatarsal joints (SMJs) may be a source of pain following hallux valgus surgery. The aims of this study were to describe degenerative changes at the SMJs on weightbearing computed tomography (WBCT) scans and, secondarily, investigate their association with 1-year patient-reported outcome scores following a modified Lapidus procedure for hallux valgus. We hypothesized that reduced joint space in the SMJs would correlate with worse patient-reported outcomes. Methods: Fifty-seven hallux valgus patients who underwent a modified Lapidus procedure had preoperative and minimum 5-month postoperative WBCT scans, and preoperative and at least 1-year postoperative PROMIS physical function (PF), pain interference, and pain intensity scores were included. Degenerative changes at the SMJs were measured using distance mapping between the sesamoids and first metatarsal head on preoperative and postoperative WBCT scans. The minimum and average distances between the first metatarsal head and tibial sesamoid (tibial-SMJ) for each patient preoperatively and postoperatively were measured. Sesamoid station was measured on WBCT scans using a 0 to 3 grading system. Linear regression was used to investigate the correlations between minimum preoperative and postoperative tibial-SMJ distances and 1-year postoperative PROMIS scores. Results: The median minimum and average tibial-SMJ distances increased from 0.82 mm (interquartile range [IQR] 0.40-1.03 mm) and 1.62 mm (IQR 1.37-1.75 mm) preoperative to 1.09 mm (IQR 0.96-1.23 mm) and 1.73 mm (IQR 1.60-1.91 mm) postoperative (P < .001 and P < .001), respectively. In a subset of patients with complete sesamoid reduction, we found an association between preoperative minimum tibial-SMJ distance and 1-year postoperative PROMIS PF scores (coefficient 7.2, P = .02). Conclusion: Following the modified Lapidus procedure, there was a statistically significant increase in the tibial-SMJ distance. Additionally, in patients with reduced sesamoids postoperatively, reduced preoperative tibial-SMJ distance correlated with worse PROMIS PF scores. Level of Evidence: Level IV, case series.

Correlation of Clinical Outcomes and Relative Position of the First Metatarsal After the Modified Lapidus Procedure.

BACKGROUND: Hallux valgus is a complex 3-dimensional deformity, and the modified Lapidus is a commonly used procedure to correct moderate to severe cases. Shortening and elevation of the first ray can occur with this procedure, which may result in increased pressure on the lesser metatarsal heads. However, there is currently no consensus regarding an accepted length and elevation of the first ray following the modified Lapidus. Therefore, the purpose of this study is to evaluate the impact of the position of the first ray on patient-reported outcome measures. METHODS: This retrospective study identified 68 patients (72 feet) who underwent the modified Lapidus bunionectomy over a 4-year period at a single institution with a median follow-up of 24 months (range, 11-35.6 months). Patients were included if they were over 18 years of age, had pre- and postoperative weightbearing computed tomography (WBCT) scans, and preoperative and minimum 1-year postoperative Patient-Reported Outcome Measurement Information System (PROMIS) scores. PROMIS scores from 6 domains including physical function, pain interference, pain intensity, global physical health, global mental health, and depression were evaluated and compared pre- and postoperatively. Radiographic parameters were measured and compared before and after surgery. Paired t tests were used to evaluate the significance of pre- to postoperative changes. Differences between cohorts were compared using Mann-Whitney U test for continuous variables or Fisher exact test for categorical variables. Correlation between radiographic measurements and patient-reported outcomes were assessed using the Spearman rank rho estimate and visualized with scatterplots with a linear regression. RESULTS: PROMIS physical function, pain interference, pain intensity, and global physical health improved significantly following the modified Lapidus (all P < .001); however, scores did not show any significant correlation with shortening of the first ray up to a maximum shortening of 4.8 mm. The length of the first metatarsal relative to the second decreased by an average of 2.7 mm following the procedure when measured on WBCT (P < .001), and 2.6 mm when measured on plain radiographs (P < .001). No significant elevation of the first ray was observed postoperatively. CONCLUSION: This study revealed that the Lapidus bunionectomy resulted in significantly improved pain and physical function at short-term follow-up. The amount of first ray shortening and elevation that occurred in this cohort did not adversely affect patient-reported outcomes.

Nitinol Staple Use in Primary Arthrodesis of Lisfranc Fracture-Dislocations.

BACKGROUND: Primary arthrodesis of Lisfranc fracture-dislocations is a reliable treatment option, yet concerns remain about nonunion. Nitinol staple use has recently proliferated in midfoot arthrodesis. The purpose of this study is to examine the union rate of primary arthrodesis of acute Lisfranc fracture-dislocations treated with nitinol staples compared with traditional plate-and-screw fixation. The secondary objective is to assess the difference in operative times and reoperation rates. METHODS: Midfoot fracture-dislocations treated with primary arthrodesis by 7 foot and ankle orthopaedic surgeons were reviewed. Of 160 eligible patients, 121 patients (305 joints) met the required 4-month minimum radiographic follow-up. Radiographic outcomes were analyzed at the individual joint level. Each joint was classified as either staples alone (45 patients, 154 joints), staples plus plates and screws (hybrid) (45 patients, 40 joints), or plates and screws alone (31 patients, 111 joints). The primary outcome was arthrodesis union at each joint fused. RESULTS: Nonunion was more common (9.0%, 10/111) among joints fixed with plate and screws than with hybrid (2.5%, 1/40) or staples only (1.3%, 2/154) (P = .0085). Multivariable regression demonstrated that autograft use was independent associated with union (P = .0035) and plate-and-screw only fixation was an independent risk factor for nonunion (P = .0407). Median operating room and tourniquet times were shorter for hybrid (92 and 83 minutes) and staple only (67 and 63 minutes) constructs compared to plate-and-screw only fixation (105 and 95 minutes) (P ≤ .0001 and .0003). There was no difference in reoperation rates among patients with different fixation types. CONCLUSION: We found that use of nitinol compression staple and bone autograft in primary arthrodesis of Lisfranc and midfoot fracture-dislocations was associated with both improved union rates and shorter tourniquet and operative times compared to traditional plate-and-screw fixation techniques. LEVEL OF EVIDENCE: Level III, therapeutic.

Defining the Patient Acceptable Symptom State (PASS) for PROMIS After Total Ankle Replacement.

BACKGROUND: Although patient-reported outcomes (PROs), such as the Patient-Reported Outcomes Measurement Information System (PROMIS), are a key element of evaluating success after total ankle replacement (TAR), many do not explicitly state a key factor of postoperative success: is the patient satisfied with their outcome after TAR? The patient acceptable symptom state (PASS) represents the symptom threshold beyond which patients consider themselves well. This study aimed to establish the PROMIS thresholds for the PASS in a primary cohort of TAR patients. METHODS: This single-institution study included 127 primary TAR patients with preoperative and 2-year postoperative PROMIS scores. At 2 years postoperatively, patients answered 2 PASS anchor questions (Satisfaction, Delighted-Terrible scale) with Likert-scale responses. PASS thresholds with 95% confidence intervals (CIs) were calculated from PROMIS scores using an anchor-based method. Using a bootstrapping technique with 1,000 iterations, the Youden index was calculated to determine the best specificity and sensitivity coordinates to maximize their combination. Finally, preoperative variables associated with the likelihood of achieving the PASS were assessed. RESULTS: There was a strong association between PASS thresholds and PROMIS domains, especially Pain Interference (PASS threshold of <56.0, area under the receiver operating characteristic curve [AUC] = 0.940), Pain Intensity (<48.4, AUC = 0.936), and Physical Function (>44.7, AUC = 0.883). The likelihood of achieving the PASS was not affected by age, race, gender, American Society of Anesthesiologists (ASA) class, body mass index, or severity of ankle deformity. Patients with worse preoperative Physical Function and Global Mental Health scores were less likely to meet the PASS threshold for Physical Function postoperatively (p = 0.028 and 0.041). CONCLUSIONS: The ability to reach the PASS after TAR was most strongly associated with postoperative PROMIS pain scores. However, PASS thresholds were generally poorer than population means. This demonstrates that patients do not need to reach normal pain or physical function levels to have an acceptable symptom state after TAR. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Defining the patient acceptable symptom state using PROMIS following reconstruction of the progressive collapsing foot deformity.

BACKGROUND: The patient acceptable symptom state (PASS) represents the threshold beyond which patients are satisfied with their outcome. This study aimed to define PASS thresholds for progressive collapsing foot deformity (PCFD) reconstruction using Patient-Reported Outcomes Measurement Information System (PROMIS) scores and anchor question responses. METHODS: This retrospective study consisted of 109 patients who underwent flexible PCFD reconstruction, had preoperative and 2-year postoperative PROMIS scores, and 2-year postoperative anchor question responses. ROC curve analyses were performed to quantify PASS thresholds. RESULTS: PASS thresholds for the PROMIS Physical Function (PF) and Pain Interference (PI) domains were found to be lower and higher, respectively, than population norms. Furthermore, patients with higher preoperative PROMIS PF scores or lower preoperative PROMIS PI scores had a significantly higher likelihood of achieving the PASS thresholds. CONCLUSION: In addition to guiding future outcomes research, these results may help surgeons optimize treatment for PCFD and better manage patient expectations. LEVEL OF EVIDENCE: III, retrospective cohort study.

Safety of Same-Day Discharge Following Total Ankle Arthroplasty: A Retrospective Cohort Analysis.

Background: Joint replacement procedures have traditionally been performed in an inpatient setting to minimize complication rates. There is growing evidence that total ankle arthroplasty (TAA) can safely be performed as an outpatient procedure, with the potential benefits of decreased health care expenses and improved patient satisfaction. Prior studies have not reliably made a distinction between outpatient TAA defined as length of stay <1 day and same-day discharge. The purpose of our study was to compare a large volume of same-day discharge and inpatient TAA for safety and efficacy. Methods: Patients undergoing TAA at our US-based institution are part of an institutional review board-approved registry. We queried the registry for TAA performed by the single highest-volume surgeon at our institution between May 2020 and March 2022. Same-day discharge TAA was defined as discharge on the day of the procedure. Patient demographics, baseline clinical variables, concomitant procedures, postoperative complications, and patient-reported outcomes were collected. Postoperative outcomes were compared after 1:1 nearest-neighbor matching by age, sex, Charlson Comorbidity Index (CCI), and American Society of Anesthesiologists (ASA) score. Multivariable models were created for comparison with the matched cohort outcome comparison analysis. Results: Our same-day discharge group was younger (median 58 vs 67 years; P < .001), with proportionally fewer females (36.4% vs 51.4%; P = .044) and lower Charlson Comorbidity Indices (median 1 vs 3; P < .001) than the inpatient group. At a median follow-up of 1 year, after matching by age, sex, CCI, and ASA score, there was no difference in complications (P = .788), reoperations (P = .999), revisions (P = .118), or Patient-Reported Outcomes Measurement Information System (PROMIS) scores between the 2 groups. Multivariable analyses performed demonstrated no evidence of association between undergoing same-day discharge TAA vs inpatient TAA and reoperation, revision, complication, or 1-year PROMIS scores (P > .05). Conclusion: In our system of health care, with appropriate patient selection, same-day discharge following TAA can be a safe alternative to inpatient TAA. Level of Evidence: Level III, retrospective cohort study.

Peroneus Brevis to Longus Tendon Transfer in the Treatment of Flexible Progressive Collapsing Foot Deformity: A Cadaveric Study.

BACKGROUND: Although operative treatment of the flexible progressive collapsing foot deformity (PCFD) remains controversial, correction of residual forefoot varus and stabilization of the medial column are important components of reconstruction. A peroneus brevis (PB) to peroneus longus (PL) tendon transfer has been proposed to address these deformities. The aim of our study was to determine the effect of an isolated PB-to-PL transfer on medial column kinematics and plantar pressures in a simulated PCFD (sPCFD) cadaveric model. METHODS: The stance phase of level walking was simulated in 10 midtibia cadaveric specimens using a validated 6-degree of freedom robot. Bone motions and plantar pressure were collected in 3 conditions: intact, sPCFD, and after PB-to-PL transfer. The PB-to-PL transfer was performed by transecting the PB and advancing the proximal stump 1 cm into the PL. Outcome measures included the change in joint rotation of the talonavicular, first naviculocuneiform, and first tarsometatarsal joints between conditions. Plantar pressure outcome measures included the maximum force, peak pressure under the first metatarsal, and the lateral-to-medial forefoot average pressure ratio. RESULTS: Compared to the sPCFD condition, the PB-to-PL transfer resulted in significant increases in talonavicular plantarflexion and adduction of 68% and 72%, respectively, during simulated late stance phase. Talonavicular eversion also decreased in simulated late stance by 53%. Relative to the sPCFD condition, the PB-to-PL transfer also resulted in a 17% increase (P = .045) in maximum force and a 45-kPa increase (P = .038) in peak pressure under the first metatarsal, along with a medial shift in forefoot pressure. CONCLUSION: The results from this cadaver-based simulation suggest that the addition of a PB-to-PL transfer as part of the surgical management of the flexible PCFD may aid in correction of deformity and increase the plantarflexion force under the first metatarsal. CLINICAL RELEVANCE: This study provides biomechanical evidence to support the addition of a PB-to-PL tendon transfer in the surgical treatment of flexible PCFD.

Flatfoot Reconstruction for Painful Pediatric Idiopathic Flexible Flatfoot: Prospective Study Demonstrates Improved Alignment, Function, and Patient-reported Outcomes.

BACKGROUND: This prospective study was undertaken to report outcomes following reconstructive surgery for patients with painful pediatric idiopathic flexible flatfoot. METHODS: Twenty-five patients with pediatric idiopathic flexible flatfoot were evaluated pre- and post flatfoot reconstruction with lateral column lengthening (LCL). All patients had lengthening of the Achilles or gastrocnemius, while 13 patients had medial side soft tissue (MSST) procedures, 7 underwent medial cuneiform plantarflexion osteotomy (MCPO), and 5 had medializing calcaneal osteotomy. Measures of static foot alignment-both radiographic parameters and clinical arch height indices-were compared, as were measures of dynamic foot alignment and loading, including arch height flexibility and pedobarography. Preoperative and postoperative patient-reported outcome (PRO) scores were compared between those treated with or without MSST procedures. RESULTS: The median subject age was 13.8 years (range: 10.3 to 16.5) at the time of surgery. All radiographic parameters improved with surgery ( P <0.001). The mean sitting arch height index showed a modest increase after surgery ( P =0.023). Arch height flexibility was similar after surgery. The mean center-of-pressure excursion index increased from 14.1% to 24.0% ( P <0.001), and the mean first metatarsal head (MH) peak pressure dropped ( P <0.001), while the mean fifth MH peak pressure increased ( P =0.018). The ratio of peak pressure in the fifth MH to peak pressure in the second MH increased ( P =0.010). The ratio of peak pressure in the first MH to peak pressure in the second MH decreased when an MCPO was not used ( P <0.002), but it remained stable when an MCPO was included. Mean scores in all PRO domains improved ( P <0.001). Patients treated without MSST procedures showed no difference in PROMIS Pain Interference scores compared to those without MSST procedures. CONCLUSIONS: Flatfoot reconstruction surgery using an LCL with plantarflexor lengthening results in improved PROs. LCL changes but does not normalize the distribution of MH pressure loading. The addition of an MCPO can prevent a significant reduction in load-sharing by the first MH.

Outpatient Total Ankle Arthroplasty (TAA) as a Rising Alternative to Inpatient TAA: A Database Analysis.

BACKGROUND: There is growing evidence that total ankle arthroplasty (TAA) can safely be performed as an outpatient procedure, with the benefit of decreased health care expenses and improved patient satisfaction. The purpose of our study was to compare readmissions, arthroplasty failures, infections, and annual trends between outpatient and inpatient TAA using a large publicly available for-fee database. METHODS: The PearlDiver Database was queried to identify outpatient and inpatient TAA-associated claims for several payer types from January 2010 to October 2021. Preoperative patient characteristics and annual trends were compared for inpatient and outpatient TAA. International Classification of Diseases, Ninth and Tenth Revision, diagnosis codes were used to identify infections and arthroplasty failures. Complications rates were compared after matching patients by age, gender, and the following comorbidities: diabetes, smoking, congestive heart failure (CHF), hypertension (HTN), obesity, and chronic kidney disease (CKD). RESULTS: A total of 12 274 patients were included in the final exact-matched analysis for complications, with 6137 patients in each group. Outpatients had a significantly lower rate of readmission within 90 days (2.6% vs 4.0%, P < .001), arthroplasty failure (4.1% vs 6.9%, P < .001), and infection (2.4% vs 3.1%, P = .015). Among database enrollees, outpatient TAA has risen in proportion to inpatient TAA from 2019 to 2021. CONCLUSION: Outpatient TAA had lower rates of risk-adjusted readmission, arthroplasty failure, and infection compared to inpatient TAA. LEVEL OF EVIDENCE: Level III, retrospective comparative database study.

Midterm Outcomes of the INBONETM II Total Ankle Arthroplasty.

As the number of total ankle arthroplasties (TAA) performed continues to increase, understanding midterm outcomes can guide both implant selection and preoperative patient counseling. The purpose of this study was to investigate midterm results including the survival rate and reasons for revision for the INBONETM II TAA. Patients undergoing a primary TAA with the study implant and minimum of 4.6 years postoperative follow-up were reviewed from a prospectively collected database. The primary outcome was implant survival. Secondary outcomes included coronal plane radiographic alignment, evaluation for cysts and osteolysis, and failure mode when applicable. Patients were eligible for inclusion in this study if they had a minimum of 4.6-year follow-up TAA with the study implant. Eighty-five TAAs in 83 patients were eligible for inclusion; 75 TAA in 73 patients were included in the study. The mean duration of follow up was 6.2 ± 0.9 years (range 4.7-8.1 years). Thirty-six percent of the TAAs had a preoperative coronal plane deformity of at least 10°, and 12% of the TAAs had at least 20°. There were 6 (8%) implant failures that occurred at a mean 2.0 ± 1.4 years postoperatively. Eighty-one percent of the TAAs had no reoperation events in the follow-up period. Midterm outcomes at a minimum of 4.6 years postoperatively in patients undergoing a TAA using this implant demonstrates acceptable implant survival, an approximately 20% reoperation rate, and maintenance of coronal plane alignment.

Complications, Reoperations, and Patient-Reported Outcomes Following a 2-Stage Revision Total Ankle Arthroplasty for Chronic Periprosthetic Joint Infections.

BACKGROUND: As total ankle arthroplasty (TAA) becomes more common, chronic periprosthetic joint infections (PJIs) will be encountered more frequently. No studies have reported on patient-reported outcomes following a 2-stage revision procedure for a chronic PJI after a TAA. The primary purpose of this study was to investigate postoperative clinical outcomes at a minimum of 2 years following a 2-stage revision TAA for chronic PJI. METHODS: Patients who underwent a 2-stage revision TAA for a chronic PJI (>4 weeks after a primary TAA) between January 2010 and December 2019 were eligible to be included in this study. Chronic PJI was defined as a sinus tract that directly communicated with the prosthesis or the same organism identified in ≥2 synovial fluid samples. Twelve patients were eligible to be included in this case series. One patient died prior to 2-year follow-up, which left 11 patients available for analysis. All 11 patients underwent reimplantation. The data were found not to be normally distributed; therefore, medians and interquartile ranges (IQRs) were reported. RESULTS: At a median of 3.0 years (IQR 2.0-4.0 years) following the second stage of their revision arthroplasty, the median Foot and Ankle Ability Measure (FAAM) Activities of Daily Living and Sports scores were 60.7 (IQR 52.4, 79.8) and 31.3 (IQR 9.4, 40.6), respectively. At final follow-up, 10 patients (90.9%) were ambulating with a TAA in place. Seven patients (63.6%) required a reoperation including 1 patient who underwent a below-knee amputation. CONCLUSION: Our study suggests that a 2-stage revision TAA may be an option for patients with a chronic PJI. However, patients who undergo a 2-stage revision TAA for a chronic PJI have lower than previously published 2-year FAAM scores and a high rate of reoperation. LEVEL OF EVIDENCE: Level IV, case series.

Clinical Outcomes and Rotational Correction of First Metatarso-Cuneiform Fusion With First Metatarsal to Second Cuneiform Fixation.

Background: The modified Lapidus procedure (first metatarso-cuneiform fusion) is a powerful technique for correcting triplanar deformity in hallux valgus. Although traditionally fixed with cross-screws (CS), growing awareness of intercuneiform stability and pronation deformity has led to fixation using a plate and first metatarsal-second cuneiform (1MT-2C) screw fixation (PS). We investigated Lapidus patient cohorts using CS vs PS fixation to understand patient-reported outcomes, angular and rotational correction, and complication rates. Methods: We retrospectively reviewed cases of modified Lapidus for hallux valgus by a single surgeon. Patients were divided into CS or PS groups according to fixation. All patients had preoperative Patient Reported Outcome Measurement Information System (PROMIS) scores and minimum 12 months of follow-up. PROMIS scores in 6 key domains were compared within and between groups. Radiographic assessment of hallux valgus angle and intermetatarsal angle were performed on pre- and postoperative XR. Pronation of the first ray was measured on pre- and postoperative weightbearing computed tomography. Results: We compared 42 patients with PS fixation to 43 with CS fixation. Both groups had significant improvement in hallux valgus angle and intermetatarsal angle (P < .001), with no difference between groups. PS patients experienced a greater correction of first metatarsal pronation, an average reduction of 11 degrees, compared to 8 degrees in the CS group (P < .039). Both cohorts experienced improvement in PROMIS physical function, pain interference, pain intensity, and global physical function. There were no differences in PROMIS score improvements between the cohorts. The CS group started weightbearing at 6 weeks vs 3.6 weeks for the PS group. Complication and revision rates were similar. Conclusion: A plate and 1MT-2C screw fixation provides safe, robust fixation of Lapidus procedure and prevents instability through the intercuneiform joint. We observed similar improvement in PROMIS compared with patients treated with cross-screws. Complications did not increase despite the PS group weightbearing much earlier. PS patients achieved greater first ray rotational correction. Level of Evidence: Level III, retrospective cohort study.

Relationship Between Preoperative PROMIS Scores and Postoperative Outcomes in Hallux Rigidus Patients Undergoing Cheilectomy.

BACKGROUND: Previous studies have demonstrated that preoperative patient-reported outcome measures are associated with postoperative outcomes in foot and ankle surgery, and also in specific procedures such as bunionectomy, flatfoot reconstruction, and total ankle replacement. The primary purpose of this study was to determine if preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) physical function, pain interference, pain intensity, and depression scores were associated with the ability of patients undergoing cheilectomy for hallux rigidus to achieve a minimal clinically important difference (MCID) of improvement. METHODS: This retrospective study included preoperative and ≥2-year postoperative PROMIS physical function, pain interference, pain intensity, and depression scores for 125 feet in 118 patients undergoing cheilectomy collected from an institutional review board (IRB)-approved foot and ankle registry database. MCIDs were established using distribution-based methods to determine clinical significance of improvements in PROMIS scores. Receiver operating characteristic (ROC) curves and area under the curve analyses were used to determine which preoperative PROMIS scores were associated with patients meeting the MCID. RESULTS: ROC analysis found statistically significant areas under the curve (AUCs) for the physical function domain (AUC 0.71), pain intensity (AUC 0.70), and depression (AUC 0.79) PROMIS domains. Subsequent analyses were unable to identify clinically useful 95% sensitivity and specificity preoperative thresholds, with the exception of the 95% sensitivity PROMIS physical function threshold. A preoperative physical function score of greater than 53.2 resulted in a 63% probability of achieving the MCID. The pain interference PROMIS domain did not demonstrate a statistically significant AUC. CONCLUSION: Preoperative PROMIS physical function, pain interference, pain intensity, and depression scores are minimally associated with preoperative to 2-year postoperative improvement in patients undergoing cheilectomy. It may be difficult to determine which patients improve from a cheilectomy based on the severity of symptoms they exhibit preoperatively. LEVEL OF EVIDENCE: Level IV, retrospective case series.

The Association of Crista Volume With Sesamoid Position as Measured From 3D Reconstructions of Weightbearing CT Scans.

BACKGROUND: Malposition of the sesamoids relative to the first metatarsal head may relate to intersesamoid crista underdevelopment or erosion. Using 3-dimensional models created from weightbearing CT (WBCT) scans, the current work examined crista volume and its relationship to first metatarsal pronation and sesamoid station. METHODS: Thirty-eight hallux valgus (HV) patients and 10 normal subjects underwent weightbearing or simulated WBCT imaging. The crista was outlined by the inferior articular surface, and a line was drawn to connect the lowest point of each sulcus on either side of the intersesamoidal crista throughout the length of the crista. The volume was calculated. Sesamoid station and first metatarsal pronation were calculated from the 3D reconstructions. The mean crista volumes between HV and normal patients were statistically compared, as were the crista volume and pronation angle between sesamoid stations. RESULTS: The mean crista volume in HV patients was 80.10 ± 35 mm3 and in normal subjects was 150.64 ± 24 mm3, which differed significantly between the 2 groups (P < .001). Mean crista volumes were found to be statistically significantly different between the sesamoid stations (P < .001) with decreasing crista volumes significantly and strongly correlated with increasing sesamoid station (r = -0.80, P < .001). There was no difference in the mean pronation angle between the 4 sesamoid stations (P = .37). The pronation angle was not associated with crista volume (P = .52). CONCLUSION: HV patients have lower mean crista volume than normal patients. Crista volume is correlated with sesamoid station. Pronation of the first metatarsal was not associated with crista volume. CLINICAL RELEVANCE: Crista volume may offer an additional determinant for the severity of hallux valgus.

Association of First Metatarsal Pronation Correction With Patient-Reported Outcomes and Recurrence Rates in Hallux Valgus.

BACKGROUND: The purpose of this study was to determine if a postoperative decrease in first metatarsal pronation on 3-dimensional imaging was associated with changes in patient-reported outcomes as measured by the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function, pain interference, and pain intensity domains or recurrence rates in patients with hallux valgus (HV) who undergo a first tarsometatarsal fusion (modified Lapidus procedure). METHODS: Thirty-nine consecutive HV patients who met the inclusion criteria and underwent a modified Lapidus procedure had preoperative and ≥2-year postoperative PROMIS scores and had first metatarsal pronation measured on preoperative and at least 5-month postoperative weightbearing CT scans were included. Multivariable regression analyses were used to investigate differences in the change in PROMIS domains preoperatively and 2 years postoperatively between patients with "no change/increased first metatarsal pronation" and "decreased first metatarsal pronation." A log-binomial regression analysis was performed to identify if a decrease in first metatarsal pronation was associated with recurrence of the HV deformity. RESULTS: The decreased first metatarsal pronation group had a significantly greater improvement in the PROMIS physical function scale by 7.2 points (P = .007) compared with the no change/increased first metatarsal pronation group. Recurrence rates were significantly lower in the decreased first metatarsal pronation group when compared to the no change/increased first metatarsal pronation group (risk ratio 0.25, P = .025). CONCLUSION: Detailed review of this limited cohort of patients who underwent a modified Lapidus procedure suggests that the rotational component of the HV deformity may play an important role in outcomes and recurrence rates following the modified Lapidus procedure. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Pronation on weightbearing radiographs does not correlate with pronation from weightbearing CT scans.

INTRODUCTION: In hallux valgus (HV), first metatarsal pronation is increasingly recognized as an important aspect of the deformity. The purpose of this study was to compare pronation in HV patients determined from the shape of the lateral head of the first metatarsal on AP weightbearing radiographs with pronation calculated from weightbearing CT (WBCT) scans. METHODS: Patients were included in this study if they had preoperative and 5-month postoperative WBCT scans and corresponding weightbearing AP radiographs of the affected foot. Pronation of the first metatarsal on WBCT scans was measured using a 3D CAD model and the alpha angle and categorized into four groups on radiographs. Association between pronation groups on radiographs and WBCT scans was determined using Spearman correlation coefficients (rs) and by comparing mean WBCT pronation of the first metatarsal between plain radiograph pronation groups. RESULTS: Agreement between the two observers' pronation on radiographs was good (k = 0.634) and moderate (k = 0.501), respectively. There was no correlation between radiographic pronation and the 3D CAD model (rs < 0.15). Preoperatively, there was weak correlation between the alpha angle and the radiographic pronation groups (rs = 0.371, P = 0.048) although this relationship did not hold postoperatively (rs = 0.330, P = 0.081). There was no difference in mean pronation calculated on WBCT scans between the plain radiographic groups. CONCLUSION: Pronation of the first metatarsal measured on weightbearing AP radiographs had moderate interobserver agreement and was only weakly associated with pronation measured from WBCT scans. These results suggest that first metatarsal pronation measured on weightbearing radiographs is not a substitute for pronation measured on WBCT scans. LEVEL OF EVIDENCE: III, retrospective cohort study.

Spare the Talonavicular Joint! The Role of Isolated Subtalar Joint Fusion in the Treatment of Progressive Collapsing Foot Deformity.

Surgical management of progressive collapsing foot deformity continues to evolve. Previous studies have demonstrated that fusion of the talonavicular joint results in limited hindfoot motion and, therefore, may accelerate adjacent-joint arthrosis. Recent literature has supported using alternative arthrodesis constructs that spare the talonavicular joint, such as naviculocuneiform or isolated subtalar fusions, which may maintain some hindfoot motion through the talonavicular joint yet adequately address a patient's deformity. Concomitant reconstructive procedures may be used in addition to subtalar fusion to address severe deformities. Isolated subtalar fusions may be considered in cases of sinus tarsi or subfibular impingement deformities.

Modified Lapidus vs Scarf Osteotomy Outcomes for Treatment of Hallux Valgus Deformity.

BACKGROUND: The Lapidus procedure and scarf osteotomy are indicated for the operative treatment of hallux valgus; however, no prior studies have compared outcomes between the procedures. The aim of this study was to compare clinical and radiographic outcomes between patients with symptomatic hallux valgus treated with the modified Lapidus procedure versus scarf osteotomy. METHODS: This retrospective cohort study included patients treated by 1 of 7 fellowship-trained foot and ankle surgeons. Inclusion criteria were age older than 18 years, primary modified Lapidus procedure or scarf osteotomy for hallux valgus, minimum 1-year postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores, and minimum 3-month postoperative radiographs. Revision cases were excluded. Clinical outcomes were assessed using 6 PROMIS domains. Pre- and postoperative radiographic parameters were measured on anteroposterior (AP) and lateral weightbearing radiographs. Statistical analysis utilized targeted minimum-loss estimation (TMLE) to control for confounders. RESULTS: A total of 136 patients (73 Lapidus, 63 scarf) with an average of 17.8 months of follow-up were included in this study. There was significant improvement in PROMIS physical function scores in the modified Lapidus (mean change, 5.25; P < .01) and scarf osteotomy (mean change, 5.50; P < .01) cohorts, with no significant differences between the 2 groups (P = .85). After controlling for bunion severity, the probability of having a normal postoperative intermetatarsal angle (IMA; <9 degrees) was 25% lower (P = .04) with the scarf osteotomy compared with the Lapidus procedure. CONCLUSION: Although the modified Lapidus procedure led to a higher probability of achieving a normal IMA, both procedures yielded similar improvements in 1-year patient-reported outcome measures. LEVEL OF EVIDENCE: Level III, retrospective cohort.

Correlation of Different Methods of Measuring Pronation of the First Metatarsal on Weightbearing CT Scans.

BACKGROUND: There is no consensus in the foot and ankle literature regarding how to measure pronation of the first metatarsal in patients with hallux valgus. The primary purpose of this study was to compare 2 previously published methods for measuring pronation of the first metatarsal and a novel 3-dimensional measurement of pronation to determine if different measurements of pronation are associated with each other. METHODS: Thirty patients who underwent a modified Lapidus procedure for their hallux valgus deformity were included in this study. Pronation of the first metatarsal was measured on weightbearing computed tomography (WBCT) scans using the α angle with reference to the floor, a 3-dimensional computer-aided design (3D CAD) calculation with reference to the second metatarsal, and a novel method, called the triplanar angle of pronation (TAP), that included references to both the floor (floor TAP) and base of the second metatarsal (second TAP). Pearson's correlation coefficients were used to determine if the 3 calculated angles of pronation correlated to each other. RESULTS: Preoperative and postoperative α angle and 3D CAD had no correlation with each other (r = 0.094, P = .626 and r = 0.076, P = .694, respectively). Preoperative and postoperative second TAP and 3D CAD also had no correlation (r = 0.095, P = .624 and r = 0.320, P = .09, respectively). However, preoperative and postoperative floor TAP and α angle were found to have moderate correlations (r = 0.595, P = .001 and r = 0.501, P = .005, respectively). CONCLUSION: The calculation of first metatarsal pronation is affected by the reference and technique used, and further work is needed to establish a consistent measurement for the foot and ankle community. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Preoperative Patient-Reported Outcome Measures Relationship With Postoperative Outcomes in Flexible Adult-Acquired Flatfoot Deformity.

BACKGROUND: Previous studies have demonstrated that procedure-specific thresholds using preoperative patient-reported outcome scores may be used to predict postoperative outcomes. The primary purpose of this study was to determine if preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) thresholds could be used to predict which patients would clinically improve at 2 years postoperatively following reconstruction of their flexible adult-acquired flatfoot deformity (AAFD). METHODS: PROMIS physical function, pain interference, and depression scores were prospectively collected preoperatively and at a minimum of 2 years postoperatively for 75 feet with flexible AAFD. Minimal clinically important differences (MCIDs) were calculated to establish significant postoperative improvement. Receiver operating characteristic curves and area under the curve analyses were employed to determine whether preoperative PROMIS scores could be used to predict postoperative outcomes. RESULTS: The PROMIS physical function receiver operating characteristic curve analysis (area under the curve = 0.913, P < .001) found that a preoperative PROMIS physical function score greater than 45.7 resulted in a 14.3% probability of achieving the MCID, whereas a preoperative score of less than 40.8 had a 97.7% probability of achieving the MCID. A preoperative PROMIS pain interference score (area under the curve = 0.799, P < .001) less than 54.1 had only a 23.1% probability of achieving the MCID at 2 years postoperatively. CONCLUSIONS: Preoperative PROMIS physical function and pain interference scores could be used to predict postoperative improvement in patients with flexible AAFD. These results may help surgeons counsel patients regarding the anticipated benefit of surgery. LEVEL OF EVIDENCE: Level III, retrospective comparative series.