Review of clinical approaches and diagnostic quantities used in pedobarographic measurements.

The non-invasive nature of pedobarographic measurements is particularly attractive to researchers for analyzing and characterizing the impact of specific pathological foot conditions. However, adequate clinical use of pedobarographic technology requires a profound technical and methodological knowledge. Several papers summarized the technical capacities of pedobarographic technology. Moreover, methodological expertise has grown considerably during the last two decades. Therefore, two crucial decisions have to be made before pathomechanical modelling or functional interpretation of foot and lower limb disorders can be pursued. The first is the selection of the specific method to analyse the dynamic plantar footprint, and the second is the choice of parameters to quantify the results. In the first part of this paper, we review the different methods used to analyse the dynamic plantar footprint and discuss their conceptual backgrounds. We also aim to illustrate the clinical relevance of each method and elaborate on the future perspectives. In the second part, we review quantification methods of pedobarographic measurements. The latter is of primary relevance to clinicians and investigators with a special interest in foot and lower limb biomechanics.

The effect of ankle and hindfoot malalignment on foot mechanics in patients suffering from post-traumatic ankle osteoarthritis.

BACKGROUND: Ankle and hindfoot malalignment is a common finding in patients suffering from post-traumatic ankle osteoarthritis. However, no studies have addressed the effect of concomitant foot deformities on intrinsic foot kinematics and kinetics. Therefore, the objective of this study was to investigate the effect of ankle and hindfoot malalignment on the kinematics and kinetics of multiple joints in the foot and ankle complex in patients suffering from post-traumatic ankle osteoarthritis. METHODS: Twenty-nine subjects with post-traumatic ankle osteoarthritis participated in this study. Standardized weight-bearing radiographs were obtained preoperatively to categorize patients as having cavus, planus or neutral ankle and hindfoot alignment, based on 4 X-ray measurements. All patients underwent standard gait assessment. A 4-segment foot model was used to estimate intrinsic foot joint kinematics and kinetics during gait. Statistical parametric mapping was used to compare foot kinematics and kinetics between groups. FINDINGS: There were 3 key findings regarding overall foot function in the 3 groups of post-traumatic ankle osteoarthritis: (i) altered frontal and transverse plane inter-segmental angles and moments of the Shank-Calcaneus and Calcaneus-Midfoot joints in the cavus compared to the planus group; (ii) in cavus OA group, Midfoot-Metatarsus joint abduction sought to compensate the varus inclination of the ankle joint; (iii) there were no significant differences in inter-segmental angles and moments between the planus and neutral OA groups. INTERPRETATION: Future studies should integrate assessment of concomitant foot and ankle deformities in post-traumatic ankle osteoarthritis, to provide additional insight into associated mechanical deficits and compensation mechanisms during gait.

Plantar pressure relief using a forefoot offloading shoe.

AIM: To assess the effectiveness of the Barouk(®) second-generation postoperative forefoot relief shoes during appropriate use of the shoe on healthy subjects. MATERIALS AND METHODS: A convenience sample of 35 volunteer subjects (17 women, 18 men) was recruited to participate in this study. Dynamic foot loading was evaluated with inshoe plantar pressure measurements. Subjects were asked to walk two trials at a self-selected speed: (a) in their mass-produced shoes to assess baseline pressure values, defined as 100% and (b) with the Barouk(®) postoperative shoe on the right foot and their own shoe on the left side. Data analysis was tested for statistical differences with paired Student's t-tests (with p<0.05 as a significance level). RESULTS: The Barouk(®) second-generation postoperative forefoot relief shoes relieved forefoot pressure in all trials. For all 35 volunteers, there was a 79-96% mean peak pressure reduction (p<0.001) of the forefoot except for the fifth metatarsal head during appropriate use of the postoperative shoe. In contrast to the results for the forefoot, a significant increase of the peak pressure values was observed in the heel region. Similar findings were observed for the pressure-time integral values. CONCLUSION: The data of our study provide evidence that the second-generation Barouk(®) shoe relieve pressure of the forefoot with appropriate use.

Clinical assessment of 115 cases of hindfoot fusion with two different types of graft: Allograft+DBM+bone marrow aspirate versus autograft+DBM.

INTRODUCTION: Nonunion is a common complication (15%) of hindfoot and ankle arthrodesis. Autograft can improve the fusion rate because of its osteoconductive, osteoinductive and osteogenic properties. However, autograft harvesting is a source of morbidity. One alternative is to combine allograft with demineralized bone matrix (DBM) and iliac bone marrow aspirate (BMA). This combination graft has similar biological properties to healthy bone. When used alone, allograft has osteoconductive and sometimes structural properties. DBM provides osteoinduction and improves the osteconductivity. BMA adds cells and thereby osteogenic potential. HYPOTHESIS: Given its intrinsic properties, allograft-DBM-BMA is as effective as autograft-DBM treatment while simplifying the clinical practice. MATERIAL AND METHODS: One hundred and fifteen cases of ankle and hindfoot arthrodesis were studied in 82 patients divided in two groups: autograft-DBM vs allograft-DBM-BMA. Treatment effectiveness was assessed using clinical (time to fusion, fusion rate) and radiological (trabecular bone bridge, disappearance of joint space) criteria. A CT scan was done in 60% of cases when fusion could not be confirmed using the clinical and radiological criteria. RESULTS: There was no significant difference between the two groups in terms of fusion rate, time to fusion, number of heterotopic ossifications, revision rate and quantity of DBM used. The nonunion rate was 18% in the autograft group and 13% in the allograft group. The infection rate was 11% in the autograft and 4% in the allograft group. DISCUSSION: Allograft-DBM-BMA is an alternative to autograft-DBM that provides similar effectiveness without increasing the number of nonunion or complications. Osteonecrosis and surgical revision are risk factors. LEVEL OF EVIDENCE: III retrospective study.

Comparison of foot segmental mobility and coupling during gait between patients with diabetes mellitus with and without neuropathy and adults without diabetes.

BACKGROUND: Reduction in foot mobility has been identified as a key factor of altered foot biomechanics in individuals with diabetes mellitus. This study aimed at comparing in vivo segmental foot kinematics and coupling in patients with diabetes with and without neuropathy to control adults. METHODS: Foot mobility of 13 diabetic patients with neuropathy, 13 diabetic patients without neuropathy and 13 non-diabetic persons was measured using an integrated measurement set-up including a plantar pressure platform and 3D motion analysis system. In this age-, sex- and walking speed matched comparative study; differences in range of motion quantified with the Rizzoli multisegment foot model throughout different phases of the gait cycle were analysed using one-way repeated measures analysis of variance (ANOVA). Coupling was assessed with cross-correlation techniques. FINDINGS: Both cohorts with diabetes showed significantly lower motion values as compared to the control group. Transverse and sagittal plane motion was predominantly affected with often lower range of motion values found in the group with neuropathy compared to the diabetes group without neuropathy. Most significant changes were observed during propulsion (both diabetic groups) and swing phase (predominantly diabetic neuropathic group). A trend of lower cross-correlations between segments was observed in the cohorts with diabetes. INTERPRETATION: Our findings suggest an alteration in segmental kinematics and coupling during walking in diabetic patients with and without neuropathy. Future studies should integrate other biomechanical measurements as it is believed to provide additional insight into neural and mechanical deficits associated to the foot in diabetes.

Scarf osteotomy without internal fixation to correct hallux valgus.

Scarf osteotomy of the first metatarsal bone to correct hallux valgus deformity has benefited from a number of improvements over the past two decades, most notably regarding the internal fixation method. Internal fixation was deemed mandatory by the authors of early case-series studies. Maestro suggested eliminating the proximal screw by locking the two fragments distally: a notch was created via a medial extension of the cephalic part of the osteotomy, the plantar fragment was displaced laterally, and the distal end of the proximal fragment was then fit into the notch (secondary cut and interlocking joint technique). To further develop this concept and to increase the potential range of translation, we developed an original technique involving distal locking without shortening and proximal stabilisation by impaction of a cortical-cancellous bone graft taken from the medial overhanging edge of the proximal fragment. This original technical variant has not been reported previously.

Diabetic foot: the orthopedic surgery angle.

As diabetes takes on pandemic proportions, it is crucial for the orthopedic surgeon to be aware of the issues involved in diabetic foot. Ulceration is related to neuropathy and to arterial disease, a vital prognostic factor for healing; infection plays an aggravating role, increasing the risk of amputation. At-risk feet need to be screened for. Ulcer classification is essential, to set treatment strategy and determine prognosis. Before any treatment is decided on, neuropathy, vascular insufficiency and infection should individually be assessed by clinical examination and appropriate additional work-up. Despite the International Consensus on the Diabetic Foot recommendations, management of diabetic foot in Europe still varies greatly from country to country, very few of which have established reference centers. Management of diabetic foot remains multidisciplinary; but it has been shown that the orthopedic surgeon should play a central role, providing a biomechanical perspective so as to avoid complications recurrence. Strategy notably includes prevention of at-risk foot, revascularization surgery (which should systematically precede orthopedic surgery in case of critical vascular insufficiency), and treatment of ulcers, whether these latter are associated with osteitis or not. Indications for "minor" amputation should be adequate, and meticulously implemented. "Acute foot" is a medical emergency, entailing massive empirically selected I.V. antibiotics to "cool" the lesion. Prophylactic surgery to limit further risks of ulceration is to be indicated with caution and only when clearly justified. France urgently requires accredited specialized multidisciplinary centers to manage severe lesions: deep and infected ulceration, advanced arteriopathy, and Charcot foot arthropathy.

Posterior arthroscopic subtalar arthrodesis: ten cases at one-year follow-up.

BACKGROUND: Isolated subtalar arthrodesis is the treatment of choice for several conditions -mostly subtalar arthritis, tarsal coalition and posterior tibial tendon dysfunction- unresponsive to conservative treatment. Arthroscopic procedures are an interesting recent alternative, less invasive than conventional open techniques. Posterior arthroscopy, in prone position, could be more advantageous than the conventional lateral and/or anterior approach. PATIENTS AND METHODS: Ten cases, from 20 to 59-years-old, were prospectively followed up for minimum of one-year (range 12 to 31 months). Arthritis and tarsal coalition were the most common indications. RESULTS: Fusion was observed in all cases at a maximum of nine weeks. Mean average AOFAS score improved from 47 to 78. No complications were noted related to the technique. Only two patients, operated for a symptomatic subtalar coalition, complained of some residual pain due to a lateral submalleolar impingement. Interest of preservation of vascular talar supply and bone grafting are discussed. CONCLUSION: The good results using this innovative technique are encouraging. Long-term randomized studies remain necessary to confirm the reliability of the procedure in these different indications, and the type of bone graft to favour, if really needed. LEVEL OF EVIDENCE: Level IV therapeutic study.

Tarsal tunnel syndrome and flexor hallucis longus tendon hypertrophy.

Tarsal tunnel syndrome (TTS) defines an entrapment neuropathy of the posterior tibial nerve or one of its branches, within the tarsal tunnel. Numerous etiologies have been described explaining this entrapment, including trauma, space-occupying lesions, foot deformities, etc. We present an unreported cause of a space-occupying lesion in the etiology of TTS, namely the combination of a hypertrophic long distally extended muscle belly of the flexor hallucis longus and repetitive ankle motion. Surgical debulking of the muscle belly in the posterior ankle compartment resolved all symptoms.

Technique and early experience with posterior arthroscopic tibiotalocalcaneal arthrodesis.

Tibiotalocalcaneal arthrodesis is indicated for pain relief in patients with combined arthritis of the ankle and subtalar joint. An arthroscopic posterior approach was designed to improve upon traditional methods by using a minimally invasive technique. The technique involves prone positioning of the patient, one anterolateral and two posterolateral portals, and arthroscopic debridement of both the tibiotalar and posterior talocalcaneal joint. Stabilisation is obtained with a retrograde intramedullary nail, with static interlocking. This article presents illustrative cases and discusses some of the technical advantages and disadvantages over conventional open surgery. For surgeons familiar with posterior ankle or subtalar arthroscopy, this minimally invasive debridement and nailing appears to offer superior exposure, high patient satisfaction and lower postoperative morbidity than traditional methods; fusion is encouraged by preserving the medullary reaming material at the site of the fusion.