Justin Greisberg

Deformity and degeneration in the hindfoot and midfoot joints of the adult acquired flatfoot

Adult acquired flatfoot is generally characterized by loss of the longitudinal arch, hindfoot valgus, and forefoot abduction, but the precise deformity has not been adequately described at the level of individual joints. Simulated weightbearing CT scans and plain radiographs of 37 symptomatic flat feet were examined in this study. The degree of arthritic degeneration was assessed in the major hindfoot and midfoot joints, and the location of deformity was studied along the medial column of the arch. Moderate to severe degeneration was seen in about one-third of talonavicular, subtalar, and calcaneocuboid joints. The medial column of the arch collapsed through the talonavicular joint in some feet, through the medial naviculocuneiform joint in others, but rarely through both. First tarsometatarsal joint subluxation was a frequent finding as well. In this small series, neither the degree of degenerative arthritis nor the amount of joint deformity was seen to correlate with patient age. Furthermore, no correlation was observed between foot deformity and joint degeneration.

Isolated medial column stabilization improves alignment in adult-acquired flatfoot

In some patients with painful flatfoot, realignment and arthrodesis of the medial naviculocuneiform and first tarsometatarsal joints can be done to correct alignment and relieve symptoms. The primary purpose of this radiographic study was to assess the ability of isolated medial column arthrodesis to improve hindfoot alignment. We also assessed the ability of the procedure to correct radiographic parameters of overall foot structure in acquired flatfoot. Preoperative and postoperative radiographs of 19 patients who had naviculocuneiform and/or tarsometatarsal realignment and arthrodesis for adult-acquired flatfoot were examined by two reviewers. All parameters improved, with the lateral talometatarsal angle approaching normal. A decrease in talonavicular subluxation in the axial plane suggests passive improvement in hindfoot position without direct manipulation of any hindfoot bones or joints. These observations provide evidence for a link between stability of the midfoot and alignment of the hindfoot. In carefully selected patients, medial column realignment may restore normal anatomy without fusing essential joints. Modern clinical outcome studies are the next step in the objective evaluation of this procedure. Level of Evidence: Therapeutic study, Level IV (case series-no, or historical, control group) See the Guidelines for Authors for a complete description of levels of evidence.

A surgical approach to posterior pilon fractures.

Posterior pilon fractures are injuries of the posterior tibial plafond that likely occur through a combined rotational and axial load mechanism and are often difficult to treat with standard surgical approaches to the ankle. We describe an alternative surgical approach to this injury using posteromedial, posterolateral, or combined approaches and present a series of patients with either radiographic or functional outcomes at a minimum of 1-year follow up that were treated by this method.

Abnormal microarchitecture and stiffness in postmenopausal women with ankle fractures.

BACKGROUND Ankle fractures are not typically considered osteoporotic fractures. However, bone quality in patients with low trauma ankle fractures has not been explored. METHODS Women with (n = 17) and without (n = 112) a history of low trauma ankle fracture after menopause had areal bone mineral density measured by dual-energy x-ray absorptiometry, trabecular (Tb) and cortical volumetric bone mineral density, and Tb microarchitecture measured by high-resolution peripheral computed tomography of the radius and tibia. Finite element analysis was performed to estimate bone stiffness. RESULTS Women with fractures were older (72 ± 2 vs. 68 ± 1 yr; P < 0.02) but similar with respect to race and body mass index. Mean T-scores by dual-energy x-ray absorptiometry of fracture subjects were above the osteoporotic range and did not differ from controls. By high-resolution peripheral computed tomography at the radius, fracture subjects had preferentially lower central trabecular bone density, lower Tb number, and increased separation compared with controls (P < 0.0001-0.04). At the tibia, fracture subjects had lower total and Tb density, lower Tb number, and increased Tb separation and network heterogeneity (P < 0.02). Whole-bone stiffness was 13-17% lower at the radius and tibia in fracture subjects (P < 0.003-0.01). CONCLUSIONS Postmenopausal women with ankle fractures have disrupted microarchitecture and decreased stiffness compared with women with no fracture history, suggesting that low trauma ankle fractures should be considered similarly to other classical osteoporotic fractures.

Ankle replacement: management of associated deformities

Ankle arthroplasty is emerging as an alternative to arthrodesis. Restoring and maintaining proper bony alignment and muscle balance in the limb is essential if there is to be any chance for long-term survival. Deformity can arise above the ankle, in the joint itself, or in the foot. Secondary procedures in the foot and leg, including osteotomies, fusions and muscle balancing, are performed either before or simultaneously with ankle replacement.

Achilles Lengthening Procedures

Contracture of the gastrocnemius-soleus complex with equinus deformity is a common hindfoot condition. In children, it is frequently associated with neuromuscular conditions such as cerebral palsy. In the adult population, it is linked to numerous pathologies such as adult-acquired flatfoot, diabetic neuropathic ulcers, and plantar fasciitis. With the medial column reduced, failure to achieve 10 degrees of passive ankle dorsiflexion with the knee flexed and extended suggests a contracture. This article reviews the anatomical and evolutionary basis for human foot structure, implications of tight gastrocnemius, and specific disease states. Operative releases for lengthening, including proximal gastrocnemius recession, tendo-Achilles lengthening, and endoscopic recession, are detailed.

Revision total ankle arthroplasty: conversion of New Jersey Low Contact Stress to Agility: surgical technique and case report.

Encouraged by intermediate results of second generation ankle implants, many surgeons are expanding their indications for total ankle arthroplasty1,3,5 As these devices are used in younger and more active patients, it is likely there will be an increasing number of patients with failed implants as is seen with hip and knee replacements. A major concern with ankle replacement surgery is late salvage. With significant bone loss, revision arthroplasty may not be possible, leaving arthrodesis with structural autograft or even amputation as the only options.4 The New Jersey Low Contact Stress (Endotec, South Orange, NJ) (NJLCS) total ankle implant requires relatively little initial bone resection.2 The implant relies on intact medial and lateral talar walls (medial and lateral ankle gutters) for stability. Unfortunately, subsidence of the talar component is a common mode of failure for any ankle implant, and this results in loss of the ankle gutters, making revision with a similar implant impossible. The Agility (DePuy, Warsaw, IN) total ankle does not rely on talar walls for stability. In fact, much of the talar walls are not resected, but the inner medial and lateral malleolar walls are resected during Agility ankle arthroplasty, which makes it a potential candidate for revision procedures. The NJLCS tibial component has a stem with a porous surface for bone ingrowth. Removal of this stemmed component has not been well described, but there is reasonable concern that replacement of this may cause major bone loss or even distal tibial fracture

How long should patients be kept non-weight bearing after ankle fracture fixation? A survey of OTA and AOFAS members

BACKGROUND Ankle fractures are common injuries treated routinely by orthopaedic surgeons. A variety of different post-operative protocols have been described with differing periods of non-weight bearing after surgery. The aim of this study was to identify how patient injury characteristics and medical comorbidities contribute to the period of non-weight bearing chosen by orthopaedic surgeons after open reduction and internal fixation of rotational ankle fractures. METHODS A cross sectional expert opinion survey was administered to members of the AOFAS as well as OTA to determine how long they would instruct patients to be non-weight bearing after open reduction and internal fixation of ankle fractures. Three different injury characteristics were described: supination external rotation type 4 equivalents, bimalleolar, and trimalleolar patterns. These patterns were combined with three different medical statuses: young and healthy, older and healthy, and older with significant medical comorbidity. Respondents selected how long they would keep the patient non-weight bearing after surgery for each of the potential scenarios. Finally, they were directly asked which factors they felt affected their decision about length of time to keep patients non-weight bearing. RESULTS Seven hundred and two surgeons (31%) responded to the survey. The average time of non-weight bearing selected varied from 4.9 (± 3.1) weeks for in young, healthy patients with SER4 equivalent injuries to 7.6 (± 6.0) weeks for older patients with medical comorbidities with trimalleolar fractures. Responses had a high degree of heterogeneity, but both injury pattern and medical status were significant predictors of non-weight bearing period (p<0.01), with medical status the stronger determinant. CONCLUSIONS There is significant variation among orthopaedic surgeons when selecting period of non-weight bearing after fixation of ankle fractures, with both injury pattern and medical comorbidity playing a role in decision of time to keep patient non-weight bearing. Further research further evaluating the relationship between these factors and safe periods of non-weight bearing could help identify patients that may benefit from earlier mobilization, and improve surgeons comfort with early mobilization. LEVEL OF EVIDENCE Therapeutic Level V.

Comparison of radiographic stress tests for syndesmotic instability of supination-external rotation ankle fractures: a cadaveric study.

Objective: According to the classification of Lauge–Hansen, supination–external rotation IV (OTA 44-B) injuries should not have syndesmotic instability; yet, several studies have suggested disruption is present in up to 40% of these injuries based on stress tests. In this study, we examine various stress radiographic parameters in a cadaver model of supination–external rotation IV equivalent injury. We hypothesize that external rotation stress testing and widening of the medial clear space do not always represent syndesmotic instability. Rather, the better predictor of syndesmotic instability will be an increased tibia–fibula clear space with the lateral stress test. Methods: Eleven fresh frozen human lower limbs were each secured into a custom frame. External rotation stress test was performed by applying an external moment of 7.5 Nm, and lateral stress test was performed by applying 100 N lateral pull at the distal fibula. True mortise radiographs were taken of intact ankles and while performing external rotation and lateral stress tests at each stage of sequentially sectioning the ankle ligaments. The deltoid ligament was sectioned first, then anterior–inferior tibiofibular ligament, posterior–inferior tibiofibular ligament, and interosseous membrane. Tibiofibular clear space and medial clear space were measured on each radiograph. Results: External rotation stress test produced significant medial clear space widening when the deltoid ligaments were sectioned (P < 0.05). Lateral stress test produced no significant widening of the tibiofibular clear space until interosseous membranes were sectioned (P < 0.05). Conclusions: Lateral stress test with widening of the tibiofibular clear space is the preferred indicator of syndesmotic instability. The external rotation stress is a poor indicator of syndesmotic injury in the setting of deltoid ligament injury.

First Ray Mobility Increase in Patients With Metatarsalgia

Background: The significance and measurement of first metatarsal hypermobility has been difficult to quantify in relation to transfer metatarsalgia. We evaluated the hypothesis that dynamic elevation of the first metatarsal relative to the second metatarsal could be measured with a simple device and would be associated with transfer metatarsalgia. We also assessed intraobserver and interobserver reliability of the simple device. Materials and Methods: A series of 352 patients were prospectively measured for dynamic metatarsal elevation: 64 patients with transfer metatarsalgia and 288 patients without symptoms. Results: Those with metatarsalgia symptoms had significantly greater first ray mobility (9 mm versus 7 mm; p < 0.0002) and metatarsal elevation (5 mm versus 3 mm; p < 0.0002) than patients without symptoms. Conclusion: In this prospective series, the device was reliable for measuring dynamic first metatarsal elevation at different time points with different examiners. Patients with metatarsalgia had higher dynamic metatarsal elevation compared to patients without metatarsalgia, suggesting a mechanism by which load can be transferred from the first to lesser metatarsals. Level of Evidence: III, Case Control Series