Outcomes of orthopaedic trauma patients undergoing surgery during the peak period of COVID-19 infection at a UK major trauma centre.

BACKGROUND: To review the clinical outcomes of all patients undergoing emergency orthopaedic trauma surgery at a UK major trauma centre during the first 6 weeks of the COVID-19 related lockdown. METHODS: A retrospective review was performed of all patients who underwent emergency orthopaedic trauma surgery at a single urban major trauma centre over the first six-week period of national lockdown. Demographics, co-morbidities, injuries, injury severity scores, surgery, COVID-19 status, complications and mortalities were analysed. RESULTS: A total of 76 patients were included for review who underwent multiple procedures. Significant co-morbidity was present in 72%. The overall COVID-19 infection rate of the study population at any time was 22%. Sub-group analysis indicated 13% had active COVID-19 at the time of surgery. Only 4% of patients developed COVID-19 post surgery with no mortalities in this sub-group. The overall mortality rate was 4%. The overall complication rate was 14%. However mortality and complications rates were higher if the patients had active COVID-19 at surgery, if they were over 70 years and had sustained life-threatening injuries. CONCLUSION: The overall survival rate for patients undergoing emergency orthopaedic trauma surgery during the COVID-19 peak was 96%. The rate of any complication was more significant in those presenting with active COVID-19 infections who had sustained potentially life threatening injuries and were over 70 years of age. Conversely those without active COVID-19 infection and who lacked significant co-morbidities experienced a lower complication and mortality rate.

The "Purse-string" Technique for Shoulder Stabilization, Description of the Technique, Long term Results and Literature Review.

BACKGROUND: Over the last 2 decades arthroscopic stabilization and Bankart repair has gained popularity due to the advances in materials and surgical techniques. Results of arthroscopic stabilization have been similar to open without the risks of it. The number of anchors used has been suggested to be very important in "spot-weld" arthroscopic stabilization however the "purse-string" technique (PST) can achieve similar results using only one anchor. We describe technique and long term results from using the PST and search the literature for other papers regarding PST. METHODS: Between 2003 and 2013 a total of 193 patients were operated. Patients included those with anterior instability. Using PubMed relevant studies reporting results of PST were identified. RESULTS: Mean follow up was 2 (range 0.5 to 3) years. 9 (4.7%) patients experienced recurrent instability. Almost all patients (97%) returned to their sporting and leisure activities and all professional athletes went back to the same sport. One more UK centre reported 6.1% recurrence in 114 patients at 4 years follow up. These results are similar to the published 11% recurrence of instability after "spot-weld" arthroscopic techniques at 11 years clinical follow-up. CONCLUSION: This study indicates that PST is safe and effective alternative method for the treatment of anterior shoulder instability. In this technique with one anchor simultaneous repair of labrum, creation of an anterior bumper and capsular shift can be achieved. It has the advantage of being cheaper, faster yet efficient with good long term results and leaves space for revision anchors in case of recurrence.

A comparison of the efficacy of various antioxidants on the oxidative stability of irradiated polyethylene.

BACKGROUND: Ultrahigh-molecular-weight polyethylene (UHMWPE) is subjected to radiation crosslinking to form highly crosslinked polyethylene (HXLPE), which has improved wear resistance. First-generation HXLPE was subjected to thermal treatment to reduce or quench free radicals that can induce long-term oxidative degeneration. Most recently, antioxidants have been added to HXLPE to induce oxidative resistance rather than by thermal treatment. However, antioxidants can interfere with the efficiency of radiation crosslinking. QUESTIONS/PURPOSES: We sought to identify (1) which antioxidant from among those tested (vitamin E, ß-carotene, butylated hydroxytoluene, or pentaerythritol tetrakis [methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]) causes the least reduction of crosslinking; (2) which promotes the greatest oxidative stability; and (3) which had the lowest ratio of oxidation index to crosslink density. METHODS: Medical-grade polyethylene (PE) resin was blended with 0.1 weight % of the following stabilizers: alpha tocopherol (vitamin E), ß-carotene, butylated hydroxytoluene (BHT), and pentaerythritol tetrakis [methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (a hindered phenol antioxidant [HPAO]). These blends were compression-molded into sheets and subjected to electron beam irradiation to a dose of 100 kGy. Equilibrium swelling experiments were conducted to calculate crosslink density. Each PE was subjected to accelerated aging for a period of 2 weeks and Fourier transform infrared spectroscopy was used to measure the maximum oxidation. Statistical analysis was conducted using analysis of variance with Fisher's protected least significant difference in which a p value of < 0.05 was used to define a significant difference. RESULTS: The least reduction of crosslinking in antioxidant-containing HXLPE was observed with HPAO, which had a crosslink density (n = 6) of 0.167 (effect size [ES] = 0.87; 95% confidence interval [CI], 0.162-0.173) mol/dm(3) compared with 0.139 (ES = 1.57; 95% CI, 0.132-0.146) mol/dm(3) (p = 0.020) for BHT, 0.131 (ES = 1.77; 95% CI, 0.123-0.139) mol/dm(3) (p = 0.004) for ß-carotene, and 0.130 (ES = 1.79; 95% CI, 0.124-0.136) mol/dm(3) (p = 0.003) for vitamin E, whereas pure HXLPE had a crosslink density of 0.203 (95% CI, 0.170-0.235) mol/dm(3) (p = 0.005). BHT-PE had an oxidation index of 0.21 (ES = 13.14; 95% CI, 0.19-0.22) followed by HPAO-PE, vitamin E-PE and ß-carotene-PE, which had oxidation indices of 0.28 (ES = 9.68; 95% CI, 0.28-0.29), 0.29 (ES = 9.59; 95% CI, 0.27-0.30), and 0.35 (ES = 6.68; 95% CI, 0.34-0.37), respectively (p < 0.001 for all groups). BHT-PE had the lowest ratio of oxidation index to crosslink density of the materials tested (1.49, ES = 1.94; 95% CI, 1.32-1.66) followed by HPAO-PE (1.70, ES = 1.52; 95% CI, 1.61-1.80), vitamin E-PE (2.21, ES = 0.52; 95% CI, 2.05-2.38), and ß-carotene-PE (2.69, ES = -0.43; 95% CI, 2.46-2.93) compared with control PE (2.47, 95% CI, 2.07-2.88) with ß-carotene (p = 0.208) and vitamin E (p = 0.129) not being different from the control. CONCLUSIONS: BHT-modified HXLPE was found in this study to have the lowest oxidation index as well as the lowest ratio of oxidation index to crosslink density compared with vitamin E, HPAO, and ß-carotene-modified HXLPEs. More comprehensive studies are required such as wear testing using joint simulators as well as biocompatibility studies before BHT-modified HXLPE can be considered for clinical use. CLINICAL RELEVANCE: BHT is a synthetic antioxidant commonly used in the polymer industry to prevent long-term oxidative degradation and has been approved by the FDA for use in cosmetics and foodstuffs. It may be an attractive potential stabilizer for HXLPE in total joint replacements.

Comparison of kinematic and kinetic parameters calculated using a cluster-based model and Vicon's plug-in gait.

Gait analysis is an important clinical tool. A variety of models are used for gait analysis, each yielding different results. Errors in model outputs can occur due to inaccurate marker placement and skin motion artefacts, which may be reduced using a cluster-based model. We aimed to compare a custom-made cluster model (ClusBB) with Vicon's plug-in gait. A total of 21 healthy subjects wore marker sets for the ClusBB and plug-in gait models simultaneously while walking on a 6-m walkway. Marker and force plate data were captured synchronously and joint angles/moments were calculated using both models. There was good correlation between the models (coefficient of multiple correlations > 0.65) and good intra-session correlation for both models (coefficient of multiple correlations > 0.80). Inter-subject variability was high, ranging from 15° to 40° in the sagittal plane and 11° to 52° in the coronal and transverse planes. Intra-subject variability was small for both ClusBB and plug-in gait models. Inter-subject variance tended to be high in both models for knee abduction/adduction, but particularly so for plug-in gait, suggesting that a cluster-based model may reduce the variability. The inter-subject variance in out-of-sagittal plane data is of particular importance clinically, given the reliance on these datasets in clinical decision-making.

The use of nanotechnology in tendon regeneration and repair.

Tendon injuries are common and due to their limited capacity for self-healing, the biomechanical and functional properties of healed tendon are usually inferior to normal tissue. Tissue engineering offers the hope of regenerating tendon tissue with the same biomechanical properties of the native undamaged tissue by augmenting the regenerative process of in vivo tissue or producing a functional tissue in vitro that can be implanted into the defective tendon site. Current research on tendon tissue engineering has focused on the role of stem cell and tendon derived cell therapy, scaffolds, chemical and physical stimulation and gene-therapeutic approaches. In this review we review the important functional anatomy and pathomechanics of tendon injury and discuss the current advances in tendon tissue engineering.