Foot surgery for adults with Charcot-Marie-Tooth disease.

People with Charcot-Marie-Tooth (CMT) disease often undergo foot and ankle surgery, as foot deformities are common and cause a degree of functional limitations impairing quality of life. Surgical approaches are variable and there are no evidence-based guidelines. A multidisciplinary approach involving neurology, physical therapy and orthopaedic surgery is ideal to provide guidance on when to refer for surgical opinion and when to intervene. This review outlines the range of foot deformities associated with CMT, their clinical assessment, and their conservative and surgical and postoperative management.

3-D joint space mapping at the ankle from weight-bearing CT: reproducibility, repeatability, and challenges for standardisation.

OBJECTIVES: We present a 3-D approach to joint space width (JSW) measurement across the ankle from weight-bearing CT (WBCT) to demonstrate inter-operator reproducibility, test-retest repeatability, and how differences in angulation affect ankle JSW distribution. METHODS: One side from repeat WBCT imaging of both feet and ankles was analysed from 23 individuals as part of their routine clinical care pathway. Joint space mapping was performed at four facets across the talus: talonavicular, talar dome and medial gutter (dome-medial), lateral gutter, and posterior subtalar. Inter-operator reproducibility was calculated for two users, while test-retest repeatability was calculated by comparing the two visits, both presented as Bland-Altman statistics. Statistical parametric mapping determined any significant relationships between talocrural joint space angulation and 3-D JSW distribution. RESULTS: The average ± standard deviation interval between imaging was 74.0 ± 29.6 days. Surface averaged bias ± limits of agreement were similar for reproducibility and repeatability, the latter being: talonavicular 0.01 ± 0.26 mm, dome-medial 0.00 ± 0.28 mm, lateral gutter - 0.02 ± 0.40 mm, and posterior subtalar 0.02 ± 0.34 mm. Results are presented as 3-D distribution maps, with optimum test-retest repeatability reaching a smallest detectable difference of ± 0.15 mm. CONCLUSIONS: Joint space mapping is a robust approach to 3-D quantification of JSW measurement, inter-operator reproducibility, and test-retest repeatability at the ankle, with sensitivity reaching a best value of ± 0.15 mm. Standardised imaging protocols and optimised metal artefact reduction will be needed to further understand the clinical value of these 3-D measures derived from WBCT. CLINICAL RELEVANCE STATEMENT: Weight-bearing computed tomography is an increasingly important tool in the clinical assessment of orthopaedic ankle disorders. This paper establishes the performance of measuring 3-D joint space width using this technology, which is an important surrogate marker for severity of osteoarthritis. KEY POINTS: • Joint space width values and error metrics from across the ankle measured from weight-bearing CT can be presented as 3-D maps that show topographic variation. • The best sensitivity for detecting meaningful change in 3-D joint space width at the ankle was ± 0.15 mm, a value less than the isotropic imaging voxel dimensions. • Standardised imaging protocols and optimised metal artefact reduction will be needed to understand the clinical value of 3-D measures from weight-bearing CT.

Staples and locking plates provide comparable outcomes for fixation of first metatarsal dorsiflexion osteotomies in pes cavovarus.

BACKGROUND: One commonly encountered deformity within the cavovarus foot is plantarflexion of the first metatarsal which may be a primary or secondary deformity. Correcting the plantarflexion may be achieved through a dorsiflexion osteotomy although the optimal fixation device for this osteotomy has not been determined. This clinical study compared the outcomes using staples and locking plates. METHODS: A retrospective evaluation was performed of 52 feet that had undergone dorsiflexion osteotomy of the first metatarsal as part of a cavovarus foot correction with a minimum follow-up of two years. Data was collected on deformity correction, complications and cost-analysis. RESULTS: As a cohort, Meary's angle improved from 13.4° to 7.72° (p < 0.001), Hibbs' angle improved from 117.1° to 124.2° (p < 0.001) and navicular height dropped from 52.7 mm to 47.7 mm (p < 0.001) while calcaneal inclination changed from 20.9° to 21.2° but this did not reach significance (p = 0.66). These indices and the number of complications were not significantly different between the staple and locking plate group. The overall cost of using staples was less than using locking plates. CONCLUSIONS: Both staples and locking plates are effective devices for fixation of the first metatarsal after a dorsiflexion osteotomy in cavovarus foot surgery. They were both able to provide comparable fixation, although staples were less expensive to use in our study.

Relationship between foot posture index and weight bearing computed tomography 3D biometrics to define foot alignment.

BACKGROUND: The Foot Posture Index (FPI) was originally validated only against two dimensional radiographic imaging at the time of its inception since weight bearing three dimensional (3D) imaging did not exist. This technology is now widely available but it is not known if the FPI will continue to correlate well against it. RESEARCH QUESTION: How does the clinical assessment tool of FPI correlate against 3D biometrics of foot alignment assessed on weight bearing computerised tomography (WBCT)? METHODS: The FPI and 3D biometrics of 66 feet in 33 patients presenting to a single foot and ankle unit were assessed by two observers independently. All measurements were assessed for intra-rater and inter-rater reliability, and the association between the clinically assessed FPI and radiologically assessed 3D biometrics was identified. RESULTS: The FPI demonstrated excellent intra-rater and good inter-rater reliability. All 3D biometric measures demonstrated excellent intra-rater and inter-rater reliability. A strong and significant correlation was identified between the FPI and 3D biometrics overall although subgroup analysis revealed the strength of association dropped when the hindfoot had a valgus alignment. SIGNIFICANCE: This study confirmed that the FPI is a valid tool for assessing foot position. However, correlation between the FPI and 3D biometrics fell in the valgus aligned hindfoot so caution must be used when the FPI is used for assessment in this population.

The dowel technique for first metatarso-phalangeal joint arthrodesis in revision surgery with bone loss.

BACKGROUND: The operative management of failed first metatarso-phalangeal joint (MTPJ) surgery is often complicated by bone loss and shortening of the hallux. Restoration of first ray length and alignment often cannot be achieved with in situ fusion and reconstruction techniques with bone graft are therefore required. We present a novel technique of longitudinal (proximo-distal) bone dowel arthrodesis for first MTPJ arthrodesis with bone loss. METHODS: Between August 2007 and February 2015, eight patients have been treated by the senior author with this technique. The mean age at surgery was 60.5 years (range 45-80) with seven females and one male. Index surgery was MTPJ arthrodesis (three patients), Keller excision arthroplasty (two patients), MTPJ hemiarthroplasty (two patients) and silastic arthroplasty (one patient). Clinical and radiological fusion was assessed and other radiological measurements included hallux valgus angle (HVA) and length of the hallux (LOH). RESULTS: All patients achieved fusion at a mean of 9.3 weeks (range 6-12) from surgery and only one patient required removal of metalwork. There were no major complications. The HVA improved in all cases from 21.4±2.8 pre-operatively to 11.6±3.5 post-operatively (p>0.05). The LOH also increased in all cases from 82.1±8.3mm to 86.7±8.2mm (p>0.05). The subgroup of patients who were revised from an arthroplasty, where maintenance of length rather than increase in length was desirable (hemiarthroplasty, silastic) had significantly lower increase in LOH than those revised from a non-arthroplasty index surgery (arthrodesis, Keller) (p=0.029). CONCLUSION: The dowel technique is successful for first MTPJ arthrodesis revision surgery with optimal union rates and satisfactory radiographic and clinical outcomes. It is an effective and versatile option for managing bone loss and deformity of the hallux.

Müller-Weiss Syndrome: Radiological Features and the Role of Weightbearing Computed Tomography Scan.

UNLABELLED: Müller-Weiss disease (MWD) is a rare condition that results in dorsolateral collapse of the navicular associated with rotation of the talar head and subtalar varus deformity. There are also varying degrees of midfoot collapse and associated loss of the medial arch in more advanced cases. The characteristic deformities and classification have been described on weightbearing radiographs. While early stage disease can be detected on magnetic resonance imaging and bone scan, there are considerable advantages to computed tomography (CT) scanning, in particular, weightbearing CT for further evaluation of this condition. We describe the imaging findings of this condition, and present 3 cases where weightbearing CT was used in the context of MWD. This is the first time the use of weightbearing CT scan has been reported for diagnosis and treatment of this condition. LEVELS OF EVIDENCE: Diagnostic, Level IV: Case series.

Use of bone marrow derived stem cells in trauma and orthopaedics: A review of current concepts.

There is a considerable amount of interest in the future role of bone marrow-derived stem cells (BMDSCs) and tissue engineering techniques to manage conditions within the musculoskeletal system. Repair of soft tissue and bone defects, in the early stages of injury, may lead to a reduction in progression of symptoms. Furthermore, troublesome soft tissue injuries that are notoriously fraught with problems either in healing or function, could be augmented with such techniques. The aim of this review paper is to look at the advances in such strategies to tackle these problems and assess how BMDSCs, with the aid of growth factors and scaffolds, are being used in vitro, animal and even human models to treat problems within the field of trauma and orthopaedics. There is plenty of evidence that the results are encouraging and thus gaining momentum toward their use in human studies.