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.

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.

A Staged Approach to Combined Extra-articular Limb Deformity Correction and Total Ankle Arthroplasty for End-Stage Ankle Arthritis.

BACKGROUND: Patients presenting with end-stage ankle osteoarthritis (OA) in the setting of a concomitant extra-articular limb deformity pose a challenging problem that has not yet been described in the literature. We describe a case series of patients treated with external and internal fixation techniques followed by total ankle arthroplasty (TAA) in a staged approach to treat this complex presentation. METHODS: Eight patients with limb deformity and end-stage ankle OA who underwent staged deformity correction and TAA from 2016 to 2019 at our institution were retrospectively identified. Average age was 58.5 (range, 49-68) years, with an average follow-up of 2.6 (range, 0.8-4.2) years. All patients underwent limb reconstruction with either tibial osteotomy with a circular frame (n=6) or intramedullary nail (n=2). Limb deformities consisted of the following: posttraumatic tibial malunion (2), limb length discrepancy (1), acquired tibial deformity (1), genu varum (2), or genu valgum (2). Radiographic parameters were assessed pre- and postoperatively on 51-inch standing and ankle radiographs: limb length discrepancy (LLD), genu varum/valgum deformity, recurvatum deformity, mechanical axis deviation, medial proximal tibial angle, lateral distal tibial angle, anterior distal tibial angle, and tibiotalar alignment. Pre- and postoperative patient-reported outcomes were assessed using 2 metrics, the Limb Deformity-Scoliosis Research Society (LD-SRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) scores (Physical Function, Pain Intensity, Pain Interference, Global Physical Function, and Global Mental Function). RESULTS: Following staged limb deformity correction and TAA, all patients achieved correction of LLD and angular deformities of the lower limb, along with restoration of normal alignment of the ankle joint. There was significant mean improvement in all patient-reported LD-SRS and PROMIS domains, except for LD-SRS mental health. LD-SRS function improved from 2.6 (±0.7) to 4.6 (±0.2), P = .008; pain improved from 2.9 (±0.9) to 4.8 (±0.2), P = .012; self-image improved from 2.9 (±0.4) to 4.7 (±0.3), P < .001; and total LD-SRS improved from 3.3 (±0.4) to 4.8 (±0.2), P = .002. Average satisfaction was 4.9 (±0.3). PROMIS physical function improved from 32.3 (±6.8) to 51.3 (±5.3), P = .008; pain interference improved from 66.0 (±9.1) to 41.3 (±6.2), P = .004; pain intensity improved from 60.0 (±13.3) to 33.1 (±5.3), P = .007; global physical health improved from 39.3 (±6.8) to 60.7 (±5.1), P = .002; global mental health improved from 54.8 (±5.9) to 65.6 (±2.8), P = .007. There was one incidence of pin site infection and one reoperation. CONCLUSION: Deformity correction with either external frame or intramedullary nail fixation followed by TAA in a staged approach was a viable surgical option in the treatment of end-stage ankle OA with concurrent extra-articular limb deformity. This unique approach was capable of achieving deformity correction with improved patient-reported outcomes, minimal complications, and good patient satisfaction. LEVEL OF EVIDENCE: Level IV, retrospective case series.

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.

Radiographic and Clinical Outcomes of Hallux Valgus and Metatarsus Adductus Treated With a Modified Lapidus Procedure.

BACKGROUND: Previous studies have found an increased rate of deformity recurrence in hallux valgus (HV) patients with concomitant metatarsus adductus (MA) undergoing metatarsal osteotomies. The purpose of this paper was to determine if there were radiographic or clinical outcome differences between HV patients with and without MA undergoing a modified Lapidus procedure. METHODS: One hundred forty-seven feet that underwent a modified Lapidus procedure for HV were divided into 2 groups based on their preoperative modified Sgarlato's angle: (1) the MA group had an angle ≥20 degrees and (2) the HV-only group had an angle <20 degrees. HV angle (HVA) and intermetatarsal angle (IMA) were measured on preoperative and ≥5-month postoperative weightbearing radiographs. Patient-Reported Outcome Measurement Information System (PROMIS) physical function (PF) and pain interference (PI) scores were obtained preoperatively and postoperatively. RESULTS: Patients in the MA group had a significantly higher mean postoperative HVA (10.8 vs 7.5 degrees; P = .038). There was a trend toward higher PROMIS PI scores in the MA group at 1 year postoperatively (51.9 vs 47.6; P = .088). Patients in the MA group were more likely to have a revision surgery (7.3% vs 0%; P = .021), and there was a trend toward those patients having a higher recurrence rate (17.1% vs 6.6%; P = .064). CONCLUSION: Despite potentially worse postoperative outcomes in patients with HV and MA who undergo a modified Lapidus procedure, the recurrence rates reported here are lower than those reported in the literature for patients with MA undergoing metatarsal osteotomies, indicating that a modified Lapidus procedure may be an acceptable choice in these patients. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Preoperative PROMIS Physical Function Scores Predict Postoperative Outcomes Following Total Ankle Replacement.

BACKGROUND: Despite good evidence that supports significant improvements in pain and physical function following a total ankle replacement (TAR) for end-stage ankle arthritis, there is a subset of patients who do not significantly benefit from surgery. The purpose of this study was to perform a preliminary analysis to determine if preoperative Patient-Reported Outcome Measurement Information System (PROMIS) scores could be used to predict which patients were at risk of not meaningfully improving following a TAR. METHODS: Prospectively collected preoperative and ≥2-year postoperative PROMIS physical function, pain interference, pain intensity, and depression scores for 111 feet in 105 patients were included in the study. Significant postoperative improvement was defined using minimal clinically important differences (MCIDs). Logistic regression models and area under the curve (AUC) analyses were used to determine whether preoperative PROMIS scores were predictive of postoperative outcomes. RESULTS: Receiver operating characteristic curves found statistically significant AUCs for the PROMIS physical function (AUC = 0.728, P = .004), pain intensity (AUC = 0.720, P = .018), and depression (AUC = 0.761, P < .001) domains. The preoperative PROMIS pain interference domain did not achieve a statistically significant AUC. CONCLUSION: Preoperative PROMIS physical function and pain intensity t scores may be used to predict postoperative improvement in patients following a fixed-bearing TAR; however, preoperative PROMIS pain interference scores were not good predictors. The results of this study may be used to guide research regarding patient-reported outcomes following TAR. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Clinical Outcomes and Complications With Open vs Minimally Invasive Achilles Tendon Repair.

BACKGROUND: There is no current consensus on whether to use an open or minimally invasive (MIS) approach for Achilles tendon repair after acute rupture. We hypothesized that patients in both open and MIS groups would have improved patient-reported outcome scores using the PROMIS system postoperatively, but that there would be minimal differences in these scores and complication rates between operative techniques. METHODS: A total of 185 patients who underwent surgery for an acute, unilateral Achilles tendon rupture between January 2016 and June 2019, with minimum 1-year follow-up were included in the cohort studied. The minimally invasive group was defined by use of a commercially available minimally invasive device through a smaller surgical incision (n=118). The open repair group did not use the device, and suture repair was performed through larger surgical incisions (n=67). Postoperative protocols were similar between groups. Preoperative and postoperative PROMIS scores were collected prospectively through our institution's registry. Demographics and complications were recorded. RESULTS: PROMIS scores overall improved in both study groups after operative repair. No significant differences in postoperative PROMIS scores were observed between the open and MIS repair groups. There were also no significant differences in complication rates between groups. Overall, 19.5% of patients in the MIS group had at least 1 postoperative complication (8.5% deep vein thrombosis [DVT], 3.3% rerupture, 1.7% sural nerve injury, 2.5% infection), compared to 16.4% in the open group (9.0% DVT, 1.5% rerupture, 1.5% sural nerve injury, 0% infection). CONCLUSION: Patients undergoing either minimally invasive or open Achilles tendon repair after acute rupture have similar PROMIS outcomes and complication types and incidences. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Position of the Posteromedial Ankle Structures in Patients Indicated for Total Ankle Replacement.

BACKGROUND: The posteromedial ankle structures are at risk during total ankle replacement (TAR). The purpose of our study was to investigate the distance of these structures from the posterior cortex of the tibia and talus in order to determine their anatomy at different levels of bone resection during a TAR and whether plantarflexion of the ankle reliably moved these structures posteriorly. METHODS: Ten feet in 10 patients with end-stage tibiotalar arthritis indicated for a TAR were included. Preoperative magnetic resonance images were obtained with the foot in a neutral position as well as in maximum plantarflexion to measure the distance of posteromedial ankle structures to the closest part of the posterior cortex of the tibia or talus. Wilcoxon signed-rank rests were used to investigate differences in these distances. RESULTS: The mean distance from the posterior tibial cortex to the tibial nerve at 14 and 7 mm above the tibial plafond was 8.7 mm (range 5.0-11.8 mm) and 6.7 mm (range 2.7-10.6 mm), respectively, which represented a statistically significant movement anteriorly (P = .021). The posterior tibial artery was, on average, 8.0 mm (range 3.6-13.9 mm) and 7.2 mm (range 3.1-9.4 mm) from the posterior tibial cortex at 14 and 7 mm above the tibial plafond, respectively. Distal to the tibial plafond, the posterior tibial artery and flexor digitorum longus tendons moved posteriorly by less than 1 mm in plantarflexion (all P < .05); otherwise, plantarflexion of the ankle did not affect the position of the tibial nerve, posterior tibial tendon, or flexor hallucis longus. CONCLUSION: In patients with end-stage ankle arthritis, the tibial nerve and posterior tibial artery lie, on average, between 6.5 and 10 mm from the posterior tibial and talar cortices. Plantarflexion of the ankle did not reliably move the posteromedial ankle structures posteriorly. LEVEL OF EVIDENCE: Level IV, case series, therapeutic.

Assessing the Ankle Joint Line Level Before and After Total Ankle Arthroplasty With the "Joint Line Height Ratio".

BACKGROUND: Restoring the joint line is an important principle in total knee arthroplasty. However, the effect of joint line level on patient outcomes after total ankle arthroplasty (TAA) remains unclear, as there is no established method for measuring ankle joint level in TAA. The objective of this study was to develop a reliable radiographic ankle joint line measurement method and to compare ankle joint line level measured pre-TAA, post-TAA, and in nonarthritic ankles. METHODS: A total of 112 radiographic sets were analyzed. Each set included weightbearing anteroposterior radiographs of the operative ankle taken preoperatively, 1-year postoperatively, and of the contralateral ankle. Measurements of vertical intermalleolar distance (VIMD) and vertical joint line distance (VJLD) at pre-TAA, post-TAA, and of the contralateral ankle were recorded by 2 authors on 2 separate occasions. The ratio of VJLD to VIMD was defined as the joint line height ratio (JLHR). Reliability of measurements and correlation between VIMD and VJLD were assessed. Pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHR were compared and considered significantly different if P <.05. RESULTS: The inter- and intrarater reliability of radiographic measurements was excellent (r > 0.9). There were strong positive correlations of VIMD and VJLD, r = 0.809 (pre-TAA)/0.756 (post-TAA), P < .001. Mean (SD) pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHRs were 1.54 (0.31), 1.39 (0.26), and 1.62 (0.49), respectively. Pre- and post-TAA JLHRs were significantly higher compared to the nonarthritic contralateral ankle (P < .05). JHLR was not significantly different between pre- and post-TAA (P = .15). CONCLUSION: The JLHR was reliable and could be a clinically applicable method for assessing ankle joint line level in patients undergoing TAA. End-stage ankle arthritis demonstrated elevated joint line level compared with nonarthritic ankles, and the joint line level post-TAA remained elevated compared with nonarthritic ankles. Further studies are needed to understand the effect of joint line elevation on clinical outcomes after TAA. LEVEL OF EVIDENCE: Level III, retrospective comparative study.