Centre of Rotation of the Human Subtalar Joint Using Weight-Bearing Clinical Computed Tomography

Accurate in vivo quantification of subtalar joint kinematics can provide important information for the clinical evaluation of subtalar joint function; the analysis of outcome of surgical procedures of the hindfoot; and the design of a replacement subtalar joint prosthesis. The objective of the current study was to explore the potential of full weight-bearing clinical computed tomography (CT) to evaluate the helical axis and centre of rotation of the subtalar joint during inversion and eversion motion. A subject specific methodology was proposed for the definition of the subtalar joint motion combining three-dimensional (3D) weight-bearing imaging at different joint positions with digital volume correlation (DVC). The computed subtalar joint helical axis parameters showed consistency across all healthy subjects and in line with previous data under simulated loads. A sphere fitting approach was introduced for the computation of subtalar joint centre of rotation, which allows to demonstrate that this centre of rotation is located in the middle facet of the subtalar joint. Some translation along the helical axis was also observed, reflecting the elasticity of the soft-tissue restraints. This study showed a novel technique for non-invasive quantitative analysis of bone-to-bone motion under full weight-bearing of the hindfoot. Identifying different joint kinematics in patients with ligamentous laxity and instability, or in the presence of stiffness and arthritis, could help clinicians to define optimal patient-specific treatments.

Minimally invasive distal metaphyseal metatarsal osteotomy (DMMO) for symptomatic forefoot pathology - Short to medium term outcomes from a retrospective case series

BACKGROUND

Minimally invasive distal metaphyseal metatarsal osteotomy (DMMO) may be used to treat metatarsalgia and forefoot pathology. Few large series report its results or examine the degree of metatarsal shortening with this technique. The clinical and radiographic results of a cohort of patients treated with DMMOs at our unit are reported.

METHODS

This was a single-centre retrospective study looking at the outcome of consecutive patients undergoing DMMOs. Demographics, radiological and clinical outcomes, complications and patient reported outcome measures (PROMs) were analysed.

RESULTS

DMMOs on 106 toes in 43 feet were included. Mean age was 60.2±10.2 years and median follow-up was 38 months. Concurrent procedures were performed in 26 cases (60%). DMMO was performed on multiple toes in 42 cases (97%). Mean shortening achieved was 3.6±2.2mm, 4.1±1.6mm, and 3.6±1.6mm for the second, third and fourth metatarsals respectively. Mean time to fusion was 11.4±7.8 weeks and union occurred in 105 toes (99%). The single non-union was asymptomatic at 12 months. Two patients required a subsequent additional DMMO for transfer metatarsalgia. Minor complications were seen in 11 patients (26%). At final follow-up PROMs data was available for 42 cases: mean MOxFQ was 28.8±27.6, mean EQ-5D was 0.789±0.225, mean EQ-VAS was 68.5±20.3, mean VAS-Pain score was 3.1±2.8, and patients were satisfied overall in 40 cases (95%).

CONCLUSIONS

The authors demonstrate excellent radiological and clinical outcomes in the short to medium term with DMMOs and present data on metatarsal shortening achieved with this technique.

Current concepts in the techniques, indications and outcomes of meniscal repairs

Knee arthroscopy for meniscal tears is one of the most commonly performed orthopaedic procedures. In recent years, there has been an increasing incidence of meniscal repairs, as there are concerns that meniscectomy predisposes patients to early osteoarthritis. Indications for meniscal repair are increasing and can now be performed in older patients who are active, even if the tear is in the avascular zone. Options for meniscal tear management broadly fall into three categories: non-operative management, meniscal repair or meniscectomy. With limited evidence directly comparing each of these options optimal management strategies can be difficult. Decision making requires thorough assessment of patient factors (e.g. age and comorbidities) and tear characteristics (e.g. location and reducibility). The purpose of this paper is, therefore, to review the management options of meniscal tears and summarize the evidence for meniscal tear repair.

A novel freehand method for patellar resurfacing in total knee replacement

Patellar resurfacing in the context of primary total knee replacement (TKR) and in the presence of patella-femoral osteoarthritis is common and widespread practice, as it reduces the rate of re-operation and anterior knee pain. There are several measuring devices and cutting jigs available in the market, which aim to aid with accurately resecting the patellar articular surface. A common characteristic of these jigs is that the patella needs to be everted at some stage to apply them and use them. The senior author of this paper has developed a method of performing patellar resection with the use of simple instruments with no need to evert it and while it engages the trochlea in a physiological position. We propose that this method is reproducible and produces cuts that are parallel to the trochlea.