Aims

Within the UK, around 70,000 patients suffer neck of femur (NOF) fractures annually. Patients presenting with this injury are often frail, leading to increased morbidity and a 30-day mortality rate of 6.1%. COVID-19 infection has a broad spectrum of clinical presentations with the elderly, and those with pre-existing comorbidities are at a higher risk of severe respiratory compromise and death. Further increased risk has been observed in the postoperative period. The aim of this study was to assess the impact of COVID-19 infection on the complication and mortality rates of NOF fracture patients.

Introduction: Osteochondral lesions (OCL) of the talar dome are defects of the cartilaginous surface and underlying bone of the superior articular surface of the talus. Their natural history is uncertain, but the association with residual, debilitating ankle pain is strong. Literature describes OCL’s as occurring anterolaterally or posteromedially, with associated localising symptoms. Early diagnosis of OCL’s may be important in preventing progression. The aim of this study was to investigate the value of clinical findings when compared to MRI scanning.

Materials and Methods: Patients with reported OCL’s of the talar dome on MRI were asked to indicate the location of their ankle pain. Subsequently they were physically examined to identify the area of maximum tenderness. Direct visual measures were taken of these sites, using modified anthropometry. The patient, examiner and person measuring were blind to the MRI scan. The lesion on MRI was then measured and locations compared for any correlation, distance and association.

Results: A series of eighteen OCL’s were studied. The strongest correlation was between the subject and the examiner in the axial plane (medial/lateral). The weakest was between MRI and clinical locations in the axial plane. Overall, the greatest difference between locations was between clinical examination and MRI. Euclidean distances showed that clinical predictions of lesion site were only reliable to within approximately 5cm.

Discussion and conclusion: Although there was a correlation between some locations, measure reliability negated this as the distances between sites represented the maximal distances within the ankle joint. We suggest that OCL of the talar dome result in pain that is poorly localised with respect to the site of the lesion. Suspicion of OCL must remain high in cases of un-resolving ankle pain, irrespective of specific clinical findings and early evaluation with the use of MRI scanning is justified.

The study evaluated and compared the three-dimensional (3-D) changes in geometry of the first metatarsal following scarf osteotomy. All osteotomies were performed on standardised Sawbone® models by consultant orthopaedic surgeons with a sub-specialist interest in foot and ankle surgery. The study considered the inter-surgeon variances in interpretation and performance of the scarf osteotomy with respect to intra-surgeon variances. The analysis used an accurate digitising system to measure and record points on the Sawbone® models in 3-D space. Computer software performed vector analysis to calculate 3-D rotations and translations of the first metatarsal head as well as the inter-metatarsal angle. Bone cut lengths and displacements were measured using a digital Vernier caliper. One surgeon performed the osteotomy ten times to form an intra-surgeon control dataset, while ten different surgeons each did one scarf osteotomy to form an inter-surgeon test dataset. Both surgical groups produced reductions in the 3-D inter-metatarsal angle with non-significant differences between the groups (p> 0.05). In contrast, the test group demonstrated highly significant (p=0.000) greater variance compared with the control dataset for all of the variables (bone cut length, proximal and distal metatarsal displacements plus angulation of the distal fragment) associated with surgical technique. In addition, there were highly significant (p=0.02 and p=0.002) greater variances in the interpretation of the degree to which the metatarsal head should be translated medially (X) and inferiorly (Z). There was also a significant (p=0.001) increase in variances in the rotations about the dorsi/plantarflexion (X) axis. The only significant differences (all p=0.000) attributable solely to differences in mean values were in proximal-distal (Y) translation, pronation (Y) rotation and medial (Z) rotation. The test group applied greater medial and plantarflexion rotation of the metatarsal head than the control surgeon and significantly less (p=0.000) shortening of the first metatarsal than the control surgeon. The results of this geometric study demonstrate the versatility of the scarf osteotomy. In addition, it indicated notable out-of-plane metatarsal head rotations and translations effected by the scarf osteotomy. As a result of the multi-planar nature of the osteotomy, there is a potential risk of producing unintended rotational mal-unions in all three planes. These rotational mal-unions may account for some of the poorer outcomes documented within the literature.

Background: Accurate history and examination is often supported by radiological imaging and diagnostic injection to diagnose joint pathology. In the foot and ankle communications have previously been reported which may reduce the sensitivity of this technique.

Method: We analysed the findings of 389 arthrograms of the foot and ankle, identifying any joint communications noted on imaging. A single consultant radiologist using local anaesthetic and contrast performed all injections.

Results: Observed results were similar to those previously reported for joint communications, with 13.9% of cases showing a communication between the ankle and subtalar joints (10% reported incidence), and a 42.3% communication rate between the talonavicular and calcaneocuboid joints. We also identified previously unreported communications between the anterior subtalar and naviculocuneiform joints (8%), anterior subtalar and calcaneocuboid joints (9%) and the naviculocuneiform and tarsometatarsal joints (1.1%).

Conclusion: This study confirms the presence of multiple joint communications within the foot, and highlights the potential importance of arthrography in the diagnosis of foot and ankle pathology. These communications must be appreciated when considering joint fusion within the foot and ankle, especially where local anaesthetic injection has been used to aid diagnosis.

The positioning of components in knee replacement is related to outcome and for this reason a study has been conducted to compare the exact position of the tibial and femoral components in total knee arthroplasty with the placement as judged by the surgeon at the time of operation.

Operating surgeons of a range of grades completed a pro-forma immediately after operating on 25 patients having total knee replacement. Patients were entered into the study by consent providing that they had osteoarthritis and this was their first ever lower limb joint replacement. The form detailed where the surgeon considered he had placed the femoral component in the coronal plane and in terms of rotation upon the femur. They were asked to state what lines or angles of reference they had used and whether they had used intra or extra medullary jigs. Likewise for the tibia, implant position was detailed for coronal, sagittal and transverse planes. The proforma stated the grade of operating surgeon but were otherwise kept anonymous.

All study patients had pre and postoperative CT scans. These involved an AP scannogram and transverse sections, according to a protocol, through the femoral neck, femoral condyles, tibial plateau and ankle. By comparing bony landmarks seen on the pre-operative CT scans with lines of reference from the components post-operatively the exact position of the implant was determined in the transverse and coronal planes. For the sagittal plane (slope) the standard lateral X-ray was used.

For the femur all operations were carried out using intra-medullary jigs. For the femoral component the difference was not significant between the measured position and the surgeons estimate in any plane (p=0.937 for coronal and p=0.432 for transverse). The measured position of the component was not related to the grade of the operating surgeon nor to the axis nor technique of reference used.

For the tibial component, coronal alignment was significantly different (p=0.001) with the measured position being in more varus than was estimated. The range of transverse placement was from 4° of external rotation to 35° of internal rotation of the tibial prosthesis with reference to the tibial tubercle centre. This was significantly different to that estimated by the surgeon (p< 0.001). Estimation of slope in the sagittal plane was good. None of these differences were related to operator grade. For 15 of the TKR’s the tibail component was aligned using intra-medullary techniques. This was related to the accuracy of positioning of the prosthesis with significantly better estimation compared to those in which extra-medulary jigs had been used (p=0.002 for the transverse plane and p=0.065 for the coronal plane).

This study has demonstarted that surgeons are able to accurately judge the position of insertion of the femoral component in total knee replacement. Surgeons are poor at estimating the position of the tibial component in the transverse and coronal planes but better in the sagittal plane. Due to the difficulty in its assessment rotational alignment has been ignored in arthroplasty but as with alignment in the other planes it is likely to have a bearing on outcome. Improved techniques to help us judge placement of knee components are needed.