Acute trunnion failure of a TMZF alloy stem with large diameter femoral heads.

INTRODUCTION: Femoral head-neck modularity in total hip arthroplasty (THA) is advantageous but taper corrosion at the trunnion can result in implant failure. We report two cases of acute catastrophic trunnion failure with a TMZF alloy cementless stem. METHODS: Demographic, clinical, radiographic and operative data including implant retrieval was recorded and is presented. RESULTS: Case 1: A 79 year old farmer presented with sudden onset of hip pain and an inability to weight bear. He underwent a cementless large diameter stemmed metal-on-metal system (MITCH acetabular component, 56mm cobalt chrome head 4.5 lateralised Accolade TMZF, Stryker) nine years previously. He denied symptoms prior to his presentation to the Emergency Department.Case 2: An 86 year old gentleman presented with sudden onset of hip pain and inability to weight bear. He underwent a cementless large diameter stemmed metal-on-poly THA (Trident acetabular component, X3 polyethylene insert, 44mm cobalt chrome head, 4.5 lateralised Accolade TMZF, Stryker)nine years previously. This man had been complaining of mild hip symptoms prior to presentation. CONCLUSION: Patients that have received TMZF alloy cementless stems coupled with CoCr alloy heads are at risk of catastrophic trunnion failure. Importantly, background trunnion corrosion may occur silently and present emergently irrespective of surveillance.

Lateral extra-articular tenodesis with ACL reconstruction demonstrates better patient-reported outcomes compared to ACL reconstruction alone at 2 years minimum follow-up.

PURPOSE: The role for extra-articular procedures in addition to ACL reconstruction to restore rotational stability is debated. We use lateral extra-articular tenodesis (LEAT) for patients that meet criteria. Our null hypothesis was that there would be no difference between two groups of patients that were treated with ACL reconstruction alone or ACL reconstruction with LEAT according to criteria. METHODS: A prospectively collected database of patients that were treated primarily according to the presence of a high-grade pivot shift with LEAT at the time of ACL reconstruction was propensity-matched with a group of patients that underwent ACL reconstruction alone. Minimum follow-up was 2 years. Stratified variable analysis of the groups was also performed. RESULTS: There were 218 and 55 patients in the ACL reconstruction group and ACL reconstruction with LEAT group, respectively. There were 125 patients and 46 patients after propensity matching with a median follow-up of 52 months and 27 months, respectively. Post-operative Lysholm score (P = 0.005), Tegner activity index (P = 0.003) and time to return to sport (P < 0.001) favoured ACL reconstruction with LEAT compared to ACL reconstruction alone. Sports with frequent change of direction maneuvers and higher rates of ACL injury (rugby, soccer, skiing) favoured ACL reconstruction with LEAT versus ACL reconstruction alone (P = 0.001). No significant difference in re-operation rate or type of surgery was found between the two surgical groups after propensity matching but 13 patients in the ACL reconstruction-only group re-injured their ACL, 8 of whom required supplementary LEAT at the time of revision surgery. CONCLUSION: Patient-reported outcomes and return to multi-directional sports after ACL reconstruction favour LEAT at the time of ACL reconstruction when narrow inclusion criteria are applied.

An assessment of early functional rehabilitation and hospital discharge in conventional versus robotic-arm assisted unicompartmental knee arthroplasty: a prospective cohort study.

AIMS: The objectives of this study were to compare postoperative pain, analgesia requirements, inpatient functional rehabilitation, time to hospital discharge, and complications in patients undergoing conventional jig-based unicompartmental knee arthroplasty (UKA) versus robotic-arm assisted UKA. PATIENTS AND METHODS: This prospective cohort study included 146 patients with symptomatic medial compartment knee osteoarthritis undergoing primary UKA performed by a single surgeon. This included 73 consecutive patients undergoing conventional jig-based mobile bearing UKA, followed by 73 consecutive patients receiving robotic-arm assisted fixed bearing UKA. All surgical procedures were performed using the standard medial parapatellar approach for UKA, and all patients underwent the same postoperative rehabilitation programme. Postoperative pain scores on the numerical rating scale and opiate analgesia consumption were recorded until discharge. Time to attainment of predefined functional rehabilitation outcomes, hospital discharge, and postoperative complications were recorded by independent observers. RESULTS: Robotic-arm assisted UKA was associated with reduced postoperative pain (p < 0.001), decreased opiate analgesia requirements (p < 0.001), shorter time to straight leg raise (p < 0.001), decreased number of physiotherapy sessions (p < 0.001), and increased maximum knee flexion at discharge (p < 0.001) compared with conventional jig-based UKA. Mean time to hospital discharge was reduced in robotic UKA compared with conventional UKA (42.5 hours (sd 5.9) vs 71.1 hours (sd 14.6), respectively; p < 0.001). There was no difference in postoperative complications between the two groups within 90 days' follow-up. CONCLUSION: Robotic-arm assisted UKA was associated with decreased postoperative pain, reduced opiate analgesia requirements, improved early functional rehabilitation, and shorter time to hospital discharge compared with conventional jig-based UKA.

Preoperative CT-Based Three-Dimensional Templating in Robot-Assisted Total Knee Arthroplasty More Accurately Predicts Implant Sizes than Two-Dimensional Templating.

Patient dissatisfaction after total knee arthroplasty (TKA) is a concern. Surgical error is a common, avoidable cause of failed TKA. Correct femoral and tibial component sizing improves implant longevity, clinical outcomes, knee balance, and pain scores. We hypothesized that preoperative three-dimensional (3D) templating for robot-assisted TKA (RA-TKA) is more accurate than two-dimensional (2D) digital templating. Prospectively collected data from 31 RA-TKAs were assessed to determine accuracy pertaining to implant sizing and positioning. All cases undergoing RA-TKA undergo preoperative CT-scans as per protocol. Three blinded observers retrospectively templated these knees for TKA using standard radiographs. We compared whether 2D templating was as accurate as CT-guided templating. Postoperative radiographs were then evaluated for sizing and positioning. Intraclass correlation coefficients (ICCs) and the effect of learning curve were assessed. Preoperative femoral component 3D templating and retrospective blinded 2D templating accuracies were 96.6% and 52.9%, respectively (χ 2: 17.965; odds ratio [OR]: 24.957, 3.250-191.661; p < 0.001). Tibial component 3D and 2D templating accuracies were 93.1% and 28.7%, respectively (χ 2: 36.436; OR: 33.480, 7.400-151.481; p < 0.001). ICC for the three radiograph observers was 0.920 (95% confidence interval [CI]: 0.652-0.890; p < 0.001) for the femur and 0.833 (0.717-0.911; p < 0.001) for the tibia, showing excellent agreement. We conclude that preoperative CT-based templating for RA-TKA more accurately predicts the size of implants compared with traditional 2D digital templating. This may improve operating room efficiency and cost containment.

Factors influencing radiation exposure during internal fixation of hip fractures.

The use of fluoroscopy is of great importance for operative fixation of fractures. Previous studies have shown an increased fluoroscopy time for intramedullary nails and with junior surgeons in comparison with more experienced surgeons. We examined the impact of operation length on fluoroscopy dose, cumulative fluoroscopy time between consultant and registrar surgeons and cumulative fluoroscopy time between dynamic hip screw and intramedullary nailing. We performed a retrospective cohort study of all patients admitted to our centre over the period of 1 year. Patients who underwent dynamic hip screw (DHS) or intramedullary (IM) nailing were identified from our in-hospital hip fracture database. Intraoperative fluoroscopy images were then accessed through our hospital's medical imaging software. A total of 137 patients were identified. Fluoroscopy reports were not available for 49 patients, resulting in a final total of 88 patients. Patients whose operation lasted longer than 1 h received a statistically significant higher dose of radiation (183.83 cGYM2 vs. 368.22 cGYM2; p value 0.0002). Operations performed by a consultant resulted in less cumulative fluoroscopy time in comparison with those performed by a registrar or specialist registrar although this was not statistically significant (00:00:53 vs. 00:00:45; p vaue 0.38). Cumulative fluoroscopy time was less in dynamic hip screw compared to long intramedullary nails (00:00:39 vs. 00:01:29; p value <0.001) and short intramedullary nails (00:00:39 vs. 00:01:52; p value 0.387). Studies, which had a cumulative fluoroscopy time exceeding 50 secs, delivered a higher radiation dose (434.34cGYM2 vs. 150.51cGYM2; p value <0.001). We concluded that there is no significant impact in cumulative fluoroscopy time in operations performed by either a registrar or consultant. Dynamic hip screws have a lower fluoroscopy time in comparison with long intramedullary nails.

International variance in the treatment of developmental dysplasia of the hip.

INTRODUCTION: Developmental dysplasia of the hip (DDH) is the most common congenital musculoskeletal abnormality. Recourse to definitive surgical treatment is not typically taken until over the age of 18-24 months. International consensus regarding age at surgery, degree of dysplasia requiring surgery and type of osteotomy is not available in the literature. STUDY AIMS: To determine variation in timing and type of osteotomy for persistent DDH across the world. METHODOLOGY: Senior authors of recent publications pertaining to hip dysplasia were sampled. Participants' practice relating to age and radiological indications for surgery were determined. RESULTS: Thirty-two surgeons responded from five different geographical regions. No inter-regional consensus was established regarding investigations to determine the need for osteotomy, preferred osteotomy type or ideal age at which to perform an osteotomy. CONCLUSION: International agreement regarding the surgical management of DDH does not exist. This common congenital condition warrants development of a treatment algorithm.

Sulphate-reducing bacteria and hydrogen sulphide in the aetiology of ulcerative colitis.

BACKGROUND: The aetiology of ulcerative colitis is uncertain but may relate to environmental factors in genetically predisposed individuals. Sulphate-reducing bacteria (SRB) have been implicated through the harmful effects of hydrogen sulphide, a by-product of their respiration. Hydrogen sulphide is freely permeable to cell membranes and inhibits butyrate. This review examines the available evidence relating to SRB as a possible cause of ulcerative colitis. METHODS: A literature search was conducted using the PubMed database and search terms 'sulphate reducing bacteria', 'hydrogen sulphide', 'ulcerative colitis', 'mucous gel layer' and 'trans-sulphuration'. RESULTS: Search results were scrutinized and 113 pertinent full-text articles were selected for review. Collected data related to hydrogen sulphide metabolism, SRB respiration, mucous gel layer composition and their association with ulcerative colitis. CONCLUSION: There is evidence to implicate SRB as an environmental factor in ulcerative colitis. More sophisticated mucosal dissection and molecular techniques using bacteria-directed probes are required to determine an association definitively.