Bone Density by Specific Anatomic Location Using Hounsfield Samples of the Lower Extremity: A Multi-center Retrospective Analysis.

Understanding bone mineral density and its effects on patient outcomes is a useful tool for lower extremity surgeons. Historically, dual-energy X-ray absorptiometry scans have been the gold standard for quantifying bone mineral density. In this study, we look at an indirect way to measure bone mineral density using Hounsfield units on computed tomography. The aim of this study is to establish normal physiological Hounsfield ranges in specific bones of the foot by analyzing Hounsfield unit measurements and determining associated factors. We hypothesize that there will be a difference in density based on age, sex, and anatomic location. Patient data from January 2010 to January 2020 were retrospectively analyzed from 2 institutions. Nine anatomic locations (calcaneus, talar body, talar head, navicular, cuboid, medial cuneiform, head of first and fifth metatarsal, and base of first proximal phalanx) were measured for bone mineral density averages. In total, 137 patients were evaluated (71 males, 66 females) with an average age of 54 years. Significant differences in density were found between the 9 anatomic locations. Age was confirmed to be a significant covariate with inverse relation to Hounsfield units, p < .001. There were no density differences between sexes at any of the locations, except the talar head, p < .001. This is the first study to our knowledge to establish normal physiological ranges of bone density on computed tomography for specific anatomic locations of the foot. This quantitative approach to bone density and the established effect of age, sex, and location is pivotal for diagnostic and preoperative planning.

Surgical Treatment of Plantar First Metatarsal Ulcerations in High-Risk Patients: A Case Series.

BACKGROUND: Plantar first metatarsal ulcerations pose a difficult challenge to clinicians. Etiologies vary and include first metatarsal declination, cavus foot deformity, equinus contracture, and hallux limitus/rigidus. Our pragmatic, sequential approach to the multiple contributing etiologies of increased plantar pressure sub-first metatarsal can be addressed through minimal skin incisions. METHODS: A retrospective review was performed for patients with surgically treated preulcerations or ulcerations sub-first metatarsal head. All of the patients underwent a dorsiflexory wedge osteotomy, and the need for each additional procedure was independently assessed. Equinus contracture was treated with Achilles tendon lengthening, cavovarus deformity was mitigated with Steindler stripping, and plantarflexed first ray was treated with dorsiflexory wedge osteotomy. RESULTS: Eight patients underwent our pragmatic, sequential approach for increased plantar pressure sub-first metatarsal, four with preoperative ulcerations and four with preoperative hyperkeratotic preulcerative lesions. The preoperative ulcerations were present for an average of 25.43 weeks (range, 6.00-72.86 weeks), with an average size of 0.19 cm3 (median, 0.04 cm3). Procedure breakdown was as follows: eight first metatarsal osteotomies, four Achilles tendon lengthenings, and six Steindler strippings. Postoperatively, all eight patients returned to full ambulation, and the four ulcerations healed at an average of 24 days (range, 15-38 days). New ulceration occurred in one patient, and postoperative infection occurred in one patient. There were no ulceration recurrences, dehiscence of surgical sites, or minor or major amputations. CONCLUSIONS: The outcomes in patients surgically treated for increased plantar first metatarsal head pressure were evaluated. This case series demonstrates that our pragmatic, sequential approach yields positive results. In diabetic or high-risk patients, it is our treatment algorithm of choice for increased plantar first metatarsal pressure.

Clinical Outcomes for Pilon Variant Posterior Malleolar Fractures: A Multicenter Retrospective Analysis.

Currently, there is no consensus on surgical approach for posterior malleolar fracture fragments with significant posteromedial involvement. The Bartonicek type III/Haraguchi type II posterior malleolar morphologies typically involve large posteromedial fragments, behaving like a pilon injury and have been reported as pilon variant fractures. We performed a retrospective chart review at 2 large healthcare institutions, evaluating patients that underwent surgical management of pilon variant posterior malleolar fractures and determining clinical outcomes including: time to union, union rates, soft tissue complications, infection and time to weight bearing. A total of 68 patients were included (51 females, 17 males). A total of 51 direct (19 posterolateral, 31 posteromedial), 6 indirect, and 11 no-fixation approaches were identified. Significantly different time-to-union was found between direct fixation (mean = 85.1 days), indirect fixation (mean = 74 days) and no-fixation (mean = 174.3 days) (p < .001). A posteromedial approach (mean = 63.0 days, SD = 16.6) was associated with significantly shorter time to union when compared to a posterolateral approach (mean = 124.8 days, SD = 59.4; p < .001). Fixation (direct or indirect) was associated with significantly increased likelihood of union of the overall ankle fracture pattern (52/57 = 91%) when compared to no fixation of the posterior malleolar component (9/14 = 64%), p = .01. Patients who underwent direct fixation had significantly lower incidence of neurovascular damage (6%) when compared to patients who underwent indirect fixation (33%) or no-fixation (29%) (p = .02). There was no significant difference between the groups in terms of tendon damage (p = .54), infection rates (p = .45) and time to weight bearing (p = .66). The authors suggest that surgical management and specifically direct approaches have better outcomes in the short-term follow up.

Predicting Nonunions in Ankle Fractures Using Quantitative Tibial Hounsfield Samples From Preoperative Computed Tomography: A Multicenter Matched Case Control Study.

The aim of this study is to use tibial Hounsfield unit measurements from preoperative computed tomography scans of ankle fractures to predict delayed union and nonunion. We hypothesize that patients with lower Hounsfield unit averages, an indirect measure of lower bone mineral density, in the distal tibia are more likely to develop delayed union and nonunion complications after ankle fracture surgery. Patient data from January 2010 to January 2020 were retrospectively analyzed from 2 institutions. Exposure cases of delayed union or nonunion that had preoperative computed tomography were compared to 5 controls matched for sex, age, and classification. 3 measurements were taken from the tibia on axial computed tomography and averaged to create a summative measure for overall bone health. Statistical analysis was used to analyze the relationship between the groups. 19 exposure patients were compared to 95 control patients. There were 16 females and 3 males in the exposure group aged from 30 to 88 years. Average follow-up was 1.6 years. The average exposure and control Hounsfield measurements were 186 (161-210) and 258 (248-269), respectively. Significant differences were found for all measured averages. This is the first study to our knowledge relating preoperative tibial Hounsfield measurements to healing rates of ankle fractures. Measurements taken from any of the 3 sites or the average could be an indicator of overall bone health. Using this technique on preoperative imaging will help surgeons adjust their perioperative planning for patients at higher risk for delayed union and nonunion.

The Association Between Lateral Radiographs and Axial Computed Tomography of Posterior Malleolar Fractures as a Tool for Predicting Medial Malleolar Extension: A Multi-Center Retrospective Analysis.

Posterior malleolar fractures are often part of complex ankle fracture patterns. Radiographs and computed tomography are often obtained in the preoperative setting. In this study, we compared measurements from lateral ankle radiographs with measurements on axial computed tomography. We hypothesize that there is an association between measurements taken on lateral XR and certain fracture morphology such as medial extension and that measurements taken on lateral XR can be used to predict likelihood of medial extension type fractures. A multi-center retrospective analysis was performed involving patients with trimalleolar ankle fractures treated at two large urban healthcare systems ranging from January 1, 2010 to November 1, 2019. A total of 279 patients met criteria including 186 females and 93 males aged 18 to 90 with an average age 55. Four reviewers measured continuous variables on lateral radiograph and axial computed tomography: posterior malleolus fracture height, articular surface length, medial-lateral width, and anterior-posterior depth and then agreement was assessed via intraclass correlation coefficient. Pearson correlations were calculated for all pairwise combinations of measurements. Two fracture classification systems were then evaluated for association with the continuous variables. Lateral height was divided into quartiles and analyzed for the degree of association. Positive correlation was found between lateral height and axial depth/axial width. Taller lateral height values were statistically associated with medial extension type fractures. Lateral height 24.5mm-29.5mm is 3.1x higher, and lateral height >29.5mm is 8.6x more likely to have medial extension when compared to shorter lateral heights(<20.5mm). Based on these findings we suggest increased usage of pre-operative CT and evaluation for the use of posteromedial approaches in the setting of taller lateral height fracture patterns(>24.5mm) as seen on lateral XR.

Reconciliation Between Lateral X-ray and Axial Computed Tomography Regarding Posterior Malleolus Fracture Anatomy and Medial Malleolus Involvement: A Pilot Study.

Configuration of a posterior malleolus fracture has significant variation based on mechanism of injury and concomitant ankle injuries. Radiographs obtained during early workup of ankle trauma play a pivotal role in closed reduction, surgical planning and preoperative management. Preoperative computed tomography helps distinguish fracture pathoanatomy. The purpose of this study is to relate measurements from traditional lateral radiographs with measurements on axial computed tomography. Imaging from a total of 22 patients treated at our institution from January 2008 to 2018 were evaluated. Two raters measured posterior malleolus fracture height and articular surface length on lateral radiographs, as well as medial-lateral width and anterior-posterior depth on axial computed tomography using calibrated imaging software. Posterior malleolar fractures with medial extension were recorded. Pearson correlations were calculated for all pairwise combinations of measurements. Lateral height and axial width were positively correlated. There was found to be an association between taller lateral height, and separately, wider axial width with presence of medial extension. Based on the correlations found between the measurements as well as the independent associations found with presence of medial extension, we suggest posterior-medial incision be evaluated as a potential approach in taller fractures as noted on lateral radiograph.

The Vertical Contour Calcanectomy, an Alternative Approach to Surgical Heel Ulcers: A Case Series.

Heel ulcers have a significant impact on lower-extremity morbidity and confer high risk of major amputations. Treating these ulcers is difficult because of poor tissue coverage and the bony os calcis, often leading to proximal amputation. This case series shows the vertical contour calcanectomy (VCC) as a surgical alternative in functional limb salvage. Sixteen feet (14 patients) with recalcitrant heel wounds who underwent VCC were identified. The minimum follow-up time for inclusion was 1 year. Body mass index, diabetes, renal disease, peripheral vascular disease, lymphedema/venous insufficiency, smoking status, Charcot, amputation, vascular intervention, wound recurrence, reoperation rate, and ambulatory status were evaluated. The average follow-up time was 27.1 months (range 13.5 to 51.1). At 1 year of follow-up, 56% of heel wounds (9 of 16) treated with the VCC remained closed. An average of 1.44 subsequent surgeries were required per patient. Baseline or improved ambulatory status was achieved in 69% of patients (9 of 14) at 1-year follow up and 100% of patients (8 of 8) at 2-year follow up. The overall rate of major amputation was 19%. The long-term ambulatory status of patients treated with the VCC shows promise. The VCC should be considered as an alternative, reliable, surgical limb salvage tool for heel ulcerations.

The Misdiagnosis of Acral Lentiginous Melanoma: Three Case Presentations.

Acral lentiginous melanoma (ALM) is a disease that is found on the palms, soles, and nail beds. Because these areas are not often examined during general medical examinations, the presence of ALM often goes unnoticed or the diagnosis is delayed. Research shows that the misdiagnosis of ALM is common, reported between 20% and 34%. We present three cases of ALM that were initially misdiagnosed and referred to the senior author (B.C.M.) in an effort to assess why misdiagnosis is common. The existing literature illuminates clinical pitfalls in diagnosing ALM. The differential diagnosis of many different podiatric skin and nail disorders should include ALM. Although making the correct diagnosis is essential, the prognosis is affected by the duration of the disease and level of invasiveness. Unfortunately, most of the reported misdiagnosed cases are of a later stage and worse prognosis. This review highlights that foot and ankle specialists should meet suspect lesions with a heightened index of suspicion and perform biopsy when acral nonhealing wounds and/or lesions are nonresponsive to treatment.