Custom Patient-Specific 3D-Printed Titanium Truss Tibiotalocalcaneal Arthrodesis Implants for Failed Total Ankle Replacements: Classification, Technical Tips, and Treatment Algorithm.

BACKGROUND: The management of failed total ankle replacements, with significant loss of bone stock, is challenging with high rates of complications and associated morbidity. Recent technological advances have enabled the development of patient-customized 3D-printed titanium truss arthrodesis implants, which offer an alternative salvage option for failed total ankle replacements. METHODS: A prospective observational study was performed of 6 cases of failed total ankle replacements that were managed using custom patient-specific 3D-printed titanium truss arthrodesis implants. Technical tips, classification, and a treatment algorithm were developed based on our initial experience. RESULTS: Between November 2018 and March 2022, 6 patients underwent arthrodesis for failed total ankle replacements. Follow-up was available for all cases. The mean follow-up was 3.0 years (range 1-4.5). The mean MOXFQ Index improved from 73.1 to 32.3 (P < .05). The mean EQ-5D-5L Index improved from 0.366 to 0.743 (P < .05) and the EQ-VAS also improved from 53.0 to 63.3 (P = .36). The mean VAS-Pain score at final follow-up was 27.5. There were no cases of nonunion. None of the patients were smokers. The overall complication rate was 50%. Two patients returned to surgery: one for wound washout following TAR explantation and a second for removal of metalwork 2 years following surgery for a prosthetic joint infection secondary to hematogenous spread. No patients underwent revision fixation or amputation. CONCLUSION: Custom patient-specific 3D-printed titanium truss arthrodesis implants are a viable treatment option for failed total ankle replacements.

Elective foot and ankle surgery following the peak of the COVID-19 pandemic is safe: A report of 30-day morbidity and mortality.

INTRODUCTION: The safety of resuming elective surgical services remains unclear following several surges of the COVID-19 pandemic worldwide. Multiple studies have reported high rates of post-operative mortality and pulmonary complications. 30-day outcomes on an initial cohort of patients undergoing elective foot and ankle surgery at 3 central London hospitals are presented. MATERIALS AND METHODS: This study is a retrospective review of the first 63 patients undergoing surgery following the first UK surge via a modified treatment pathway, based on published national guidelines, designed to minimise the risks to patients and staff associated with COVID-19. RESULTS: 90% of patients were ASA 1 or 2, with an average age of 46. All tested negative for COVID-19 pre-operatively and all but one underwent a general anaesthetic. 10 patients required one night hospital stays and 1 was admitted for four nights. 52 were day case procedures. 2 complications were identified, not relating to COVID-19 infection. No 30-day mortalities or pulmonary complications were recorded. CONCLUSIONS: With a community prevalence of COVID-19 of between 1 in 1500 and 1 in 1700, elective foot and ankle surgery was safe following the first surge of the pandemic in the UK. This data can guide elective service planning in countries with pandemic curves behind the UK's or in the event of further surges in national cases.

Chronic Fracture of the Posteromedial Tubercle of the Talus Masquerading as Os Trigonum Syndrome.

Posterior ankle impingement syndrome (PAIS) can be caused by osseous pathology from the posterior aspect of the talus. The commonest cause is an os trigonum, an accessory ossicle arising from the lateral tubercle of the posterior talus. We have observed cases where the osseous impingement is due to a chronic fracture nonunion of the medial tubercle of the posterior talus with unique symptoms, differentiating this clinical syndrome from the more common os trigonum syndrome. These can be readily overlooked on imaging and confused with an often coexisting os trigonum. Awareness of these lesions is paramount to ensure appropriate management and safe surgery. We describe a series of patients presenting to the senior author with this clinical syndrome, discuss its unique clinical and radiological features, and describe our surgical technique.

Saw transection of retained compression screws with damaged heads instead of removal in revision first metatarsal osteotomy: a technique tip.

Distal first metatarsal osteotomy is performed to correct hallux valgus. The surgery is being performed throughout the UK in increasing numbers. The osteotomies used are commonly fixed with one or two variable pitch compression screws. Recurrence of the deformity or inadequate correction in the primary surgery may require revision osteotomy which necessitates removal of previous screws. Revision rates for scarf osteotomy have been reported at 5%. Removal of screws can be challenging as they are often buried in bone and/or the screw heads can get damaged even despite meticulous preparation. Various techniques for removal of damaged screws are described, which require additional equipment and may result in significant loss of the host bone. We describe another technique where a standard Stryker TPS sagittal saw and saw blade (Kalamazoo, USA) are used to cut through the shaft of the compression screws in line with the planned revision osteotomy. We have successfully performed this on two occasions with good results, and describe our experience of using this technique which eliminates the need for complex over drilling procedures often required for removing stripped and retained screws.

Clarification on "Critical Comments on 'Assessment of the Thermodynamic Properties of DL-p-Mentha-1,8-diene, 4-isopropyl-1-methylcyclohexene (DL-Limonene) by Inverse Gas Chromatography (IGC)'".

A clarification is given regarding recent polemic over our original published study. The author of this polemic has claimed a few issues about the computations and data listed in our work such as choosing the wrong temperature unit and the incorrect calculation of molar heat of vaporization. Here it is elaborated the complete data and computations that are not included in the original paper, and list out also the parameters, which may be the source of difference in reported molar heat of vaporization through inverse gas chromatography methods and other conventional methods. It is showed that there are no wrong calculations or reports of molar heat of vaporization in our published paper.

Management of spiral diaphyseal fractures of the fifth metatarsal: A case series and a review of literature.

INTRODUCTION: Spiral diaphyseal fractures of the fifth metatarsal can present with significant displacement. It is considered that non-operative management is sufficient in most cases but there is no clear consensus as to what this may be. This study reports the functional outcome of this injury in a small patient cohort and is the first study to report on outcomes of different non-operative measures. MATERIAL AND METHODS: This is a retrospective study of 33 consecutive patients presenting to a central London teaching hospital who were managed by a variety of treatment modalities depending on surgeon preference which included a boot or a rigid sole shoe. Demographic data was obtained and time to pain free walking and return to normal footwear was recorded. The patients were asked how restrictive the injury was on a Likert scale (1-5). The average final follow up was 12 months. RESULTS: All fractures were managed conservatively with excellent functional outcomes. Those patients managed in a shoe had a statistically significant shorter average time to return to pain free walking (4.6 vs 8.4 weeks, p=0.027) and average time to return to normal footwear (6 vs 7.3 weeks, p=0.044) in comparison to a boot. Patients managed in a shoe reported the injury was less restrictive in comparison to patients managed in a boot (p=0.0002). The average time to evidence of bony union was 8.3 weeks. There were 3 delayed unions. CONCLUSION: All patient in this series were treated without surgery regardless of the degree of displacement. Conservative management of this fracture in a rigid sole shoe resulted in better outcomes and was reported to be less restrictive by the patients in comparison to a boot. On this basis, non-surgical management of these injuries is recommended in a shoe, full weight bearing with early range of movement of the ankle.

In Vitro Evaluation of CMV Specific CD8+T Cells Function in CMV+ Colorectal Cancer Patients Compared to Healthy Controls.

The oncogenic role of human cytomegalovirus (HCMV) has been recently shown in different cancers like colorectal cancer (CRC). According to the recent immunotherapy approach to target the CMV-expressing tumor cells, we investigated the CMV peptide-stimulated CD8+T cells functions in CRC patients compared to healthy individuals. All sixteen patients and seven controls were CMV seropositive. Blood samples were obtained from patients without chemotherapy and radiotherapy before surgery. Cytotoxic CD8+ T cells were generated using 14-day culture of PBMCs in the presences of CMV peptide epitopes and rhIL-2. In addition to the supernatant evaluations for TNF-α and IFN-γ, the functionality of CD8+ T cells was examined by detecting CD107a and intracellular IFN-γ using flow cytometry. CMV DNA was detected in tissues by Real Time PCR. CMV DNA was found in 31% of tumor tissues, while it was not seen in the adjacent non-tumor tissues. There was a close association between CMV in tumor tissue and tumor grade. Surface expression of CD107a and intracellular IFN-γ in CMV-stimulated CD8+T cells and the level of IFN-γ production in patient and control groups increased significantly after culture. The number of functions increased in patients (p<0.05) and healthy individuals after culture. Followingstimulation, expressions of CD107a and intracellular IFN-γ were elevated in tumor CMV positive patients while the TNF-α secretion was decreased. In vitro stimulation of PBMC in the presence of CMV peptide epitopes and IL-2 can be an applicable method to generate cytotoxic CD8+ T cells in CRC patients for future T cell therapy.

First metatarsophalangeal fusion using joint specific dorsal plate with interfragmentary screw augmentation: Clinical and radiological outcomes.

BACKGROUND: This study reports the outcome of a plating system for arthrodesis of the first metatarsophalangeal joint (1st MTPJ) that incorporates a lag compression screw within a low profile titanium plate with a predetermined contour. This is the first report of the outcomes of this implant from a non-affiliated centre. PATIENT AND METHODS: This is a prospective cohort study of 40 consecutive primary 1st MTPJ arthrodesis procedures. The mean age of the cohort was 56 years (range, 20-74 years). The diagnosis was hallux rigidus in 31 patients and inflammatory arthropathy in 7 patients. RESULTS: All patients achieved clinical union at 6 weeks and radiological union was confirmed on plain radiographs between 6-16 weeks. One case of hardware removal was reported. CONCLUSION: The cohort achieved consistently satisfactory results with a reliable and reproducible MTPJ position and a 100% union rate. There was a low rate of hardware removal. LEVEL OF EVIDENCE: Level IV evidence. Prospective cohort study.

Fractures of the anterior process of the calcaneum; a review and proposed treatment algorithm.

BACKGROUND: There remains a lack of recognition of these fractures, which leads to a delay in diagnosis and appropriate management. METHODS: A comprehensive literature search was performed. Following inclusion and exclusion criteria, 23 studies were available for analysis. RESULTS: Delay in diagnosis is common and has a negative impact on outcome. If an APC fracture is suspected; anteroposterior, lateral and oblique plain radiographs should be requested. Further investigation with computed tomography or magnetic resonance imaging is indicated if plain radiographs are inconclusive and patient remains symptomatic. Non-operative measures are usually adequate for most undisplaced fractures, however surgical intervention maybe required for large, intra-articular fractures in the acute setting and for non-union. CONCLUSIONS: A treatment algorithm is suggested that may help with the diagnosis and management of these injuries. LEVEL OF EVIDENCE: Level IV.

Assessment of the Thermodynamic Properties of DL-p-Mentha-1,8-diene, 4-Isopropyl-1-Methylcyclohexene (DL-limonene) by Inverse Gas Chromatography (IGC).

Limonene is a colorless liquid hydrocarbon and had been investigated as a plasticizer for many plastics. Prediction of solubility between different materials is an advantage in many ways, one of the most convenient ways to know the compatibility of materials is to determine the degree of solubility of them in each other. The concept of "solubility parameter" can help practitioners in this way.In this study, inverse gas chromatography (IGC) method at infinite dilution was used for determination of the thermodynamic properties of DL-p-mentha-1,8-diene, 4-Isopropyl-1-methylcyclohexene (DL-limonene). The interaction between DL-limonene and 13 solvents were examined in the temperature range of 63-123°C through the assessment of the thermodynamic sorption parameters, the parameters of mixing at infinite dilution, the weight fraction activity coefficient and the Flory-Huggins interaction parameters. Additionally, the solubility parameter for DL-limonene and the temperature dependence of these parameters was investigated as well.Results show that there is a temperature dependence in solubility parameter, which increases by decreasing temperature. However, there were no specific dependence between interaction parameters and temperature, but chemical structure appeared to have a significant effect on them as well as on the type and strength of intermolecular interactions between DL-limonene and investigated solvents. The solubility parameter δ2 of DL-limonene determined to be 19.20 (J/cm3)0.5 at 25°C.

Management of Paget's Disease of the Calcaneum.

The calcaneum is not the most common site for Paget's disease of bone, with only a few reports of monostotic involvement. We present 2 cases of Paget's disease of bone affecting the calcaneus, present an overview of the published data, and describe our management of these interesting cases.

Atypical Presentation of Fibrolipomatous Hamartoma of Superficial Peroneal Nerve.

Fibrolipomatous hamartoma is a rare presentation in the foot. An accurate diagnosis is key, with magnetic resonance imaging findings considered definitive. The management is dependent on the symptoms. We present an atypical presentation of fibrolipomatous hamartoma of the superficial peroneal nerve and discuss the current published data.

Comparison of three different fixation methods of calcaneal osteotomies.

BACKGROUND: There are various methods available to fix a calcaneal osteotomy, ranging from screws to plates and staples. It is not clear if one method is superior to the other. In this series we compare the complications and union rates of 3 different methods of fixation. METHODS: A retrospective review of the records of a consecutive series of patients who had a calcaneal osteotomy was undertaken. All patients had their osteotomy by the same technique, however the subsequent fixation was performed using 3 different methods: a lateral locking plate, a headless, or a headed screw. The screws were placed through a separate stab incision inserted from the infero-posterior heel. Records were kept of subsequent symptoms from the hardware and need for hardware removal as well as any complications. When screws were inserted, the entry point in relation to the weight-bearing surface of the calcaneus was also recorded. Sixty-seven osteotomies were investigated, of which 17 were fixed using a headed screw, 18 using a headless screw, and the remaining 32 were fixed using a lateral plate. RESULTS: There was an overall 97% union rate. The only 2 cases of delayed union were both fixed using a lateral plate. Overall, 47% of the headed screws, 11% of the headless screws, and 6% of the lateral plates were removed to address symptoms that were suspected to arise from the hardware. There was a 10% rate of wound complication in the lateral plate cohort. There were no cases of sural nerve injury or neuroma. No correlation was found between entry position of screw and subsequent hardware symptoms. CONCLUSIONS: Calcaneal osteotomies have high union rates regardless of fixation method. Fixation using a headed screw is associated with a high rate of secondary screw removal. This was unrelated to the position of the screw in relation to the weight-bearing surface of the calcaneus in our series. Hardware problems were less frequent in the headless screw or the lateral plate groups; however, the incidence of local wound complications and radiological delayed union was higher in the group fixed with a lateral plate. This may be related to the greater soft tissue dissection and lesser compression achieved at the osteotomy site. LEVEL OF EVIDENCE: Level III, retrospective case control study.