The optimal correction of the weight bearing line during High Tibial Osteotomy has not been determined. We used finite element modelling to simulate the effect that increasing opening wedge HTO has on the distribution of stress and pressure through the knee joint during normal gait. Subject-specific models were developed by combining geometry from 7T MRI scans and applied joint loads from ground reaction forces measured during level walking. Baseline stresses and pressures on the articulating proximal tibial cartilage and menisci were calculated. Progressive osteotomies were then simulated to shift the weight-bearing line from the native alignment towards/into the lateral compartment (between 40 – 80% of medial-lateral tibial width). Changes in calculated stresses and pressures were recorded. Both stress and pressure decreased in the medial compartment and increased in the lateral compartment as increasingly valgus osteotomies were simulated. The models demonstrated a consistent “safe zone” for weight bearing line position at 50%-65% medial-lateral tibial width, outside of which compartment stresses and pressures substantial increased. This study suggests a safe correction zone within which a medial opening wedge HTO can be performed correcting the WBL to 55% medio-lateral width of the tibia.
Endoprosthetic replacement (EPR) is an available option for the management of massive bone loss around failed knee implants. The aim of this study was to determine the results of knee EPRs performed for non-tumour indications. Since 2007, 85 EPRs were performed for in a single tertiary centre by seven surgeons. Mean age at surgery was 73.5 years (range:35–95) with infection as the most common indication (49%), followed by aseptic loosening (18%), complex primary replacement (16%), fracture (15%) and mechanical failure (2%). Mean follow up was 4 years (range:1–9). Functional outcome was determined using the Oxford Knee Score (OKS). At follow-up, 21 patients were deceased and 2 lost to follow-up. Complication rate was 19%. Of the 7 infected cases, 6 were treated with DAIR (debridement, antibiotics, and implant retention) and one underwent above knee amputation. Four of the patients undergoing DAIR were cleared of infection and 2 are on long-term antibiotics. Accounting for implant revision, loss to follow-up and those on long-term antibiotics as failures, 5-year survival was 89% with an average OKS of 25 (SD=10). This mid-term study shows that distal femur EPR is a valuable option for the increasing burden of complex revision knee surgery
Traditionally, a Surgical Tourniquet (ST) is used during Total Knee Replacement Surgery (TKRS) to prevent blood flow to the leg and improve the surgical field of view. The use of a ST is known to increase the risk of venous thromboembolism. Echogenic material, suggestive of emboli has been observed in the brain following ST deflation in TKRS despite the absence of a patent foramen ovale, likely through pulmonary shunts. The aim of this study was to assess whether cerebral emboli result from tourniquet use in TKRS and the sequelae of any emboli. 11 subjects from a single centre undergoing routine TKRS with a ST gave informed consent. Each participant had diffusion weighted MR brain imaging prior to, and within 48 hours after TKRS and completed pre and post-operative mini-mental state examinations (MMSE).Background
Methods
Since 2011, the knee service at the Nuffield Orthopaedic Centre has been offering a neutralising medial opening wedge high tibial osteotomy (HTO) to a group of patients presenting with early medial osteoarthritis of the knee, varus alignment and symptoms for more than 2 years. During development of this practice an association was observed between this phenotype of osteoarthritis and the presence of CAM deformity at the hip. A retrospective cohort study. All patients who underwent HTO since 2011 were identified (n=30). Comparator groups were used in order to establish whether meaningful observations were being made: Control group: The spouses of a high-risk osteoarthritis cohort recruited for a different study at our unit (n=20) Pre-arthroplasty group: Patients who have undergone uni-compartmental arthroplasty (UKA) for antero-medial osteoarthritis (n=20)All patients had standing bilateral full-length radiographs available for analysis using in house developed Matlab-based software for hip measurements and MediCAD for lower limb alignment measurements.Background
Methods
This article reviews four commonly used approaches to assess patient responsiveness to a treatment or therapy [Return To Normal (RTN), Minimal Important Difference (MID), Minimal Clinically Important Difference (MCID), OMERACT-OARSI (OO)], and demonstrates how each of the methods can be formulated in a multi-level modelling (MLM) framework. Data from the Arthroplasty Pain Experience (APEX) cohort study was used. Patients undergoing total hip and knee replacement completed the Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire prior to surgery and then at 3, 6 and 12 months after surgery. We compare baseline scores, change scores, and proportion of individuals defined as “responders” using traditional and multi-level model (MLM) approaches to patient responsiveness.Background
Methods
The burden of peri-prosthetic joint infection (PJI) following hip and knee surgery is increasing. Endoprosthetic replacement (EPR) is an option for management of massive bone loss resulting from infection around failed lower limb implants. To determine clinical outcome of EPRs for treatment of PJI around the hip and knee joint.Introduction
Aims
Dickkopf-3 is upregulated in OA cartilage and synovial tissue. In vitro studies show Dkk3 can prevent cartilage degradation and antagonise Wnt signaling. We hypothesis that Dkk3 can protect against OA-related cartilage destruction. Our group has previously shown that Dkk3, a member of the Dkk family of Wnt antagonists, is upregulated in OA cartilage and synovium. Levels of Dkk3 in synovial fluid are also increased in individuals with tricompartmental OA and after arthroscopy. The role of Dkk3 in cartilage or the factors regulating its expression are not currently understood. Correct regulation of cell signalling pathways is integral to cartilage homeostasis and thus the prevention of OA pathogenesis. Dkk3 is a member of the Dkk family of Wnt antagonists and therefore may impact on chondrocyte biology through interaction with the Wnt pathway. Dkk3 has also been found to influence TGFβ signalling in other cell systems.Summary Statement
Introduction
The mechanical properties of porcine tibial plateau (TP) cartilage are shown to vary topographically. Low Elastic moduli (Em) were found in the positions where unicompartimental knee osteoarthritis (OA) lesions are typically expected to develop. These results suggest that there is a different response to load in these areas. OA is one of the ten most disabling diseases in developed countries. OA of the knee, in particular, is a major cause of mobility impairment; up to 40% of the population over the age of 70 suffers from OA of the knee. It has been observed that unicompartmental knee OA occurs with very distinct and repeatable lesion patterns. It is hypothesised that these patterns are the result of differences in the material properties throughout articular cartilage. The aim of this study was to measure the mechanical properties of porcine cartilage in a whole undamaged TP.Summary
Introduction
AIS causes a loss of trunk height. This paper documents this loss against sitting height standards and assesses formulae for adjusting height loss back to the standard. A total of 334 patients (84% female) with AIS and no other known systemic disease had sitting height measured. This was compared to standards of sitting height with age and the ratio of height to sitting height with age (HSH). The corrected height was calculated using published formulae and replotted against these standards.Aim:
Methods:
Current work-hour restrictions and cost pressures have highlighted the limitations of apprenticeship-based learning, and led to the development of alternative methods to improve the skills of orthopaedic trainees outside of the clinical environment. These methods include using synthetic bones and simulators in the laboratory setting. Educational theory highlights the importance of context for effective learning, yet full-immersion simulation facilities are prohibitively expensive. This study explored the concept of contextualised training day in trauma & orthopaedics. Fifteen novice surgeons provided feedback after completing three teaching modules: OSCE-style Problem-based Learning of Orthopaedic Trauma in the Fracture Clinic Setting, utilising an actor and radiographs to teach history, examination, diagnostic and management skills The positioning, preparing and draping of a patient, and Examination under anaesthesia (EUA) for arthroscopic knee surgery, utilising an operating table and theatre equipment to teach procedural and examination skills Simulator based training for diagnostic shoulder and knee arthroscopy; and Bankart repair, utilising arthroscopic stack and synthetic joint models to develop arthroscopic motor skill and procedural knowledgeIntroduction
Methods
This study examines variations in knee arthroplasty patient reported outcome measures according to patient age. We analysed prospectively collected outcome data (OKS, Eq5D, satisfaction, and revision) on 2456 primary knee arthroplasty patients. Patients were stratified into defined age groups (< 55, 55–64, 65–74, 75–84, and ≥85 years). Oxford Knee Score and Eq5D were analysed pre-operatively, and postoperatively at 6 months and 2 years. Absolute scores and post-operative change in scores were calculated and compared between age groups. Satisfaction scores (0–100) were analysed at 6 months post-operatively. Linear, logistic and ordinal regression modelling was used to describe the association between age and outcomes, for continuous, binary and ordinal outcomes, respectively. Kaplan-Meier analysis was performed to describe revision rates at 2 years.Objectives
Methods
Unicompartmental Knee Replacement (UKR) is associated with fewer complications, faster recovery and better function than Total Knee Replacement (TKR). However, joint registries demonstrate a higher revision rate in UKR, limiting its use. Currently most UKRs are cemented and performed using a minimally invasive technique. In joint registries, common reasons for revision include aseptic loosening and pain. These problems could potentially be addressed by using cementless implants, which may provide more reliable fixation. The objectives of this study were to compare the quality of fixation (determined by the incidence and appearance of radiolucencies), and clinical outcomes of cemented and cementless UKR at five years. A randomised controlled trial was established with 63 knees (62 patients) randomised to either cemented (32 patients) or cementless UKR (30 patients). Fixation was assessed with fluoroscopic radiographs aligned to the bone-implant interface at one and five years. Outcome scores were collected pre-operatively and at one, two and five years, including Oxford Knee Score (OKS), American Knee Society Score, objective and functional (AKSS-O/F) and Tegner Activity Scale (TAS), expressed as absolute scores and 0–5 year change (δ) scores. Four patients died during the study period. There were no revisions. Mean operative time was 11 minutes shorter in the cementless group (p=0.029). At five years, there was no significant difference in any outcome measure except AKSS-F and δAKSS-F which were significantly better in the cementless group (both p=0.003). There were no femoral radiolucencies in either group. There were significantly more tibial radiolucencies in the cemented group (20/30 vs 2/27, p< 0.001). There were nine complete radiolucencies in the cemented group and none in the cementless group (p< 0.001). Cementless fixation provides improved fixation at five years compared to cemented fixation in UKR, maintaining equivalent or superior clinical outcomes with a shorter operative time and no increase in complications.
Hip arthroscopy is a relatively new procedure and evidence to support its use remains limited. Well-designed prospective clinical trials with long-term outcomes are required, but study design requires an understanding of current practice. Our aim was to determine temporal trends in the uptake of non-arthroplasty hip surgery in England between 2001 and 2011. Using procedure and diagnosis codes, we interrogated the Hospital Episode Statistics (HES) Database for all hip procedures performed between 2001 and 2011, excluding those relating to arthroplasty, tumour or infection. Osteotomy procedures were also excluded.Introduction
Methods
Restrictions placed on the working hours of doctors have led to increasing time-pressures on surgical training. Consequently, there has been growing interest in developing new techniques to teach and assess technical skills. The primary aim of this study was to determine whether a novel set of visual parameters assessing visuospatial ability, fine motor dexterity and gaze control could objectively distinguish between varying levels of arthroscopic experience. The secondary aim was to evaluate the correlations between these new parameters and previously established technical skill assessment methods. 27 subjects were divided into a “novice” group (n=7), “trainee” group (n=15) and expert group (n=5) based on previous arthroscopic experience. All subjects performed a diagnostic knee arthroscopy task on a simulator. Their performance was assessed using new simple visual parameters that included “prevalence of instrument loss,” “triangulation time” and “prevalence of look downs”. In addition, performance was also evaluated using previously validated technical skill assessment methods (a global rating scale and motion analysis).Introduction
Methods
Indications for Unicompartmental Knee Arthroplasty (UKA) vary between units. Some authors have suggested, and many surgeons believe, that medial UKA should only be performed in patients who localise their pain to the medial joint line. This is despite research showing a poor correlation between patient-reported location of pain and radiological or operative findings in osteoarthritis. The aim of this study is to determine the effect of patient-reported pre-operative pain location and functional outcome of UKA at one and five years. Pre-operative pain location data were collected for 406 knees (380 patients) undergoing Oxford medial UKA. Oxford Knee Score, American Knee Society Scores and Tegner activity scale were recorded preoperatively and at follow-up. 272/406 (67%) had pure medial pain, 25/406 (6%) had pure anterior knee pain and 109/406 (27%) had mixed or generalised pain. None had pure lateral pain. The primary outcome interval is one year; 132/406 patients had attained five years by the time of analysis and their five year data is presented. At one and five years, each group had improved significantly by each measure (mean δOKS 15.6 (SD 8.9) at year one, 16.3 (9.3) at year five). There was no difference between the groups, nor between patients with and without anterior knee pain or isolated medial pain. We have found no correlation between preoperative pain location and outcome. We conclude that localised medial pain should not be a prerequisite to UKA and that it may be performed in patients with generalised or anterior knee pain.
Motion analysis is a validated method of assessing technical dexterity within surgical skills centers. A more accessible and cost-effective method of skills assessment is to use a global rating scale (GRS). We aimed to perform a validation experiment to compare an arthroscopic GRS against motion analysis for monitoring orthopaedic trainees learning simulated arthroscopic meniscal repairs. An arthroscopic meniscal repair task on a knee simulator was set up in a bioskills laboratory. Nineteen orthopaedic trainees with no experience of meniscal repair were recruited and their performance assessed whilst undertaking a standardized meniscal repair on 12 occasions. An arthroscopic GRS, assessing parameters such as “depth perception,” “bimanual dexterity,” “instrument handling,” and “final product analysis” was used to evaluate technical skill. Performance was assessed blindly by watching video recordings of the arthroscopic tasks. Dexterity analysis was performed using a motion analysis tracking system which measured “time taken,” “total path length of the subject's hands,” and “number of hand movements”.Introduction
Methods
Musicians' hand problems are as old as music itself. These problems involve functional motor disorders which have been underestimated by musicians, who do not want to accept the possibility of reducing their professional activity and doctors who are either not knowledgeable about musicians' characteristics or underestimate this artistic activity. The aim of this study is to determine the causes of the pathologies instrumentalist musicians have, and their distribution according to age group, instrument and type of music, and thus infer the main risk factors in the occurrence of medical problems related to musicians' activity. We consider musicians those who devote themselves to the study, teaching and playing of a musical instrument. In Argentina there are about 50.000 instrumental musicians. Since over 14 years the members of “Las Manos del Músico” have treated 574 musicians. The 84% of the medical problems related to the playing of the instrument. Ages are between 13 and 78 years. The musicians treated belong to different conservatories, symphonic and popular orchestras. Each musician was studied with the same protocol, filled in by the same professional. Variables such as type of music, age, sex, instrument, dominance andrelated variables were taken into account.INTRODUCTION
MATERIALS AND METHODS
The peri-operative analgesic management of patients having either Total Knee Replacement (TKR) or Unicompartmental Knee Replacement (UKR) is an area that continues to have prominence, driven in part by the desire to reduce hospital stay, while maintaining high patient satisfaction. This is particularly relevant in the current climate of healthcare cost savings. We evaluated the role of “top up” intra-articular local anaesthetic injection after identifying that an appreciable number of patients in the unit suffered “breakthrough pain” on the first post-op day, when the effects of local analgesia are wearing off. 43 patients, who were scheduled to have a cemented Oxford UKR, were prospectively recruited and randomised. All patients had the same initial anaesthetic regime of general anaesthesia, femoral nerve block and intra-operative intra-articular infiltration of the cocktail. All patients had a 16G multi-holed epidural catheter placed intra-articularly prior to wound closure. Patients had the same operative technique, post operative rehabilitation and rescue analgesia. An independent observer recorded post-operative pain scores using a visual analogue score (1–10) every 6 hours and any rescue analgesia that was required. On the morning after surgery, 22 patients, (Group I), received 20 mls of 0.5% bupivicaine through the catheter whilst 21 patients, (Group II), had 20 mls of normal saline by the same observer, (who was blinded to the contents of the solution being injected), after which the catheter was removed.Introduction
Method
To assess the beneficial use of polypropylene mesh impregnated with vancomycin in an experimental model open fractures Gustilo IIIa in rabbits. We worked with 15 New Zeland White rabbits. All of them were carried out under general anaesthetic, a 5-cm incision longitudinal was made at the back of the right thigh. The femur was aproached and a fracture was performed with a shear, giving rise to a multifragment fracture. The wound remained open for 6 hours with the bone exposed, in a non-surgical ambient. Subsequently underwent surgical cleaning of the open fractures in two stages. The fracture was stabilized with an intramedular pin. The animals were sorted in 3 different therapeutic groups: Group 1: (5 rabbits) without other treatment. Group 2: (5 rabbits) a polypropylene mesh was placed around the fracture. Group 3: (5 rabbits) a polypropylene mesh with vancomycin was placed around the fracture. The wound was closed with nylon stiches. Three weeks postoperative, the animals were intervened surgically under general anesthesia, after aseptic cure and placement of surgical fields, femoral bone biopsies, soft tissue and mesh were taken. The rabbits were sacrified. The samples were sent to pathology and bacteriology labs.Objective
Material and Method
Despite interest, the current rate of day-case anterior cruciate ligament reconstruction (ACLR) in the UK remains low. Although specialised care pathways with standard operating procedures (SOPs) have been effective in reducing length of stay following some surgical procedures, this has not been previously reported for ACLR. We evaluate the effectiveness of SOPs for establishing day-case ACLR in a specialist unit. Fifty patients undergoing ACLR between May and September 2010 were studied prospectively (“study group”). SOPs were designed for pre-operative assessment, anaesthesia, surgical procedure, mobilisation and discharge. We evaluated length of stay, readmission rates, patient satisfaction and compliance to SOPs. A retrospective analysis of 50 patients who underwent ACLR prior to implementation of the day-case pathway was performed (“standard practice group”).Background
Methods
