Aim

Prosthetic joint infection (PJI) is a devastating and costly complication of total joint arthroplasty (TJA). Use of extended oral antibiotic prophylaxis (EOAP) has become increasingly popular in the United States following a highly publicized study (Inabathula et al) from a single center demonstrating a significant protective effect (81% reduction) against PJI in ‘high-risk’ patients. However, these results have not been reproduced elsewhere and EOAP use directly conflicts with current antibiotic stewardship efforts. In order to study the role of EOAP in PJI prevention, consensus is needed for what defines ‘high-risk’ patients. The revision TJA (rTJA) population is an appropriate group to study due to having a higher incidence of PJI. The purpose of the current study was to rigorously determine which preoperative conditions described by Inabathula et al. (referred to as Inabathula criteria (IBC)) confer a higher rate of PJI in patients undergoing aseptic rTJA.

Immigrated Canadians make up approximately 20% of the total population in Canada, and 30% of the population in Ontario. Despite universal health coverage and an equal prevalence of severe arthritis in immigrants relative to non-immigrants, the former may be underrepresented amongst arthroplasty recipients secondary to challenges navigating the healthcare system. The primary aim of this study was to determine if utilization of arthroplasty differs between immigrant populations and persons born in Canada. The secondary aim was to determine differences in outcomes following total hip and knee arthroplasty (THA and TKA, respectively).

This is a retrospective population-based cohort study using health administrative databases. All patients aged ≥18 in Ontario who underwent their first primary elective THA or TKA between 2002 and 2016 were identified. Immigration status for each patient was identified via linkage to the ‘Immigration, Refugee and Citizenship Canada’ database. Outcomes included all-cause and septic revision surgery within 12-months, dislocation (for THA) and total post-operative case cost and were compared between groups. Cochrane-Armitage Test for Trend was utilized to determine if the uptake of arthroplasty by immigrants changed over time.

There was a total of 186,528 TKA recipients and 116,472 THA recipients identified over the study period. Of these, 10,193 (5.5%) and 3,165 (2.7%) were immigrants, respectively. The largest proportion of immigrants were from the Asia and Pacific region for those undergoing TKA (54.0%) and Europe for THA recipients (53.4%). There was no difference in the rate of all-cause revision or septic revision at 12 months between groups undergoing TKA (p=0.864, p=0.585) or THA (p=0.527, p=0.397), respectively. There was also no difference in the rate of dislocations between immigrants and people born in Canada (p=0.765, respectively).

Despite having similar complication rates and costs, immigrants represent a significantly smaller proportion of joint replacement recipients than they represent in the general population in Ontario. These results suggest significant underutilization of surgical management for arthritis among Canada's immigrant populations. Initiatives to improve access to total joint arthroplasty are warranted.

Abstract

Total hip replacements (THRs) are performed by surgeons at various stages in their training, with varying levels of senior supervision. There is a balance between protecting training opportunities for the next generation of surgeons, while limiting the exposure of patients to unnecessary risk during the training process. The aim of this study was to examine the association between surgeon grade, the senior supervision of trainees, and the risk of revision following THR.

We included 603 474 primary THRs recorded in the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man (NJR) between 2003 and 2016 for an indication of osteoarthritis. Exposures were the grade of the surgeon (consultant or trainee), and whether trainees were supervised by a scrubbed consultant or not. Outcomes were all-cause revision, the indication for revision, and the temporal variation in risk of revision (all up to 10 years). Net failure was calculated using Kaplan-Meier analysis and adjusted analyses used Cox regression and flexible parametric survival analysis (adjusted for patient, operative, and unit level factors).

There was no association between surgeon grade and all-cause revision up to 10 years (crude hazard ratio (HR) 0·999, 95% confidence interval (CI) 0.936–1.065; p=0.966); a finding which persisted with adjusted analysis. Adjusted analysis demonstrated an association between trainees operating without supervision by a scrubbed consultant and an increase in all-cause revision (HR 1.100, 95% CI 1.002–1.207; p=0.045). There was an association between the trainee-performed THRs and revision due to instability (crude HR 1.143, 95% CI, 1.007–1.298; p=0.039). However, this was not observed in fully adjusted models, or when trainees were supervised by a scrubbed consultant.

Within the current training system in the United Kingdom, trainees achieve comparable outcomes to consultant surgeons when supervised by a scrubbed consultant. Revision rates are higher when trainees are not supervised by a scrubbed consultant but remain within internationally recognised acceptable limits.

Aims

The aim of this study was to conduct evidence synthesis on the available published literature of the impact of the training status of the operating surgeon (trainee vs. consultant) on the survival and revision rate of primary hip and knee replacements.

Introduction

Given the rising incidence of obesity in the adult population, it is more than likely that orthopaedic surgeons will be treating more obese patients with lumbar disc pathologies. The relationship between obesity and recurrent herniated nucleus pulposus (HNP) following microdiscectomy remains unclear.

Historically human and animal bites to the hand have resulted in significant morbidity in relation to the high risk of contamination and subsequent infection. Our study aimed to assess the outcomes following such injuries in terms of infection requiring further intervention through specialist referral to the hand surgery team at our hospital.

124 consecutive patients attending the A&E department over a three month period in 2011 were included in this retrospective study which provided 126 separate cases due to bilateral injuries (110 animal: 16 human). Data was obtained from the electronic patient management system. The demographics of each patient were recorded followed by type of bite sustained including number and size of lacerations.

79% of patients presented within 24 hours and the majority before 6 hours from injury. The majority of the forearm bites were documented as superficial abrasions and none of these went on to develop problems with infection, so the study concentrated on bite injuries to the hand of which there were 99 cases. Most hand injuries were a single puncture or laceration (64%) but in 9 cases there were greater than 3 separate wounds.

5 cases were directly referred to the Hand surgery team with 4 requiring admission and of these 3 required washout and debdridement in theatres. The remaining 94 cases were managed solely by A&E. Of these 94 cases 87 pts received Abx and 78 pts had a lavage. Overall 68% received both Abx and lavage. Subsequent to discharge from A&E only 3 developed problems with infection later (2 requiring specialist input) they were all dog bites and in keeping with the ‘typical’ bite pattern seen in other pts.

The study concluded that bites not involving joint, tendon or bone have only a small chance of causing infection provided good initial treatment.

To assess whether Patients who are clinically Obese are more likely to require further or revision Surgery following One-Level simple Microdiscectomy compared to Non-obese Patients.

Retrospective, single centre and single Surgeon review of Patients' Clinical notes of consecutive Patients who underwent primary One-Level Microdiscectomy between December 2007 and July 2009.

Background: Obesity in Surgery has become a topical subject given the increasing proportion of Surgical Patients being Obese. This study provides the largest single centre and single Surgeon comparative cohort.

All Patients had undergone One-level simple Primary Microdiscectomy Surgery. Data from the Clinical notes included Patient Demographics, level and side of operation, Length of stay and Re-Operation details. A total number of 71 Patients were eligible for inclusion of which 38 were Female and 33 Male with an average age of 41 years. 25 Patients were Clinically Obese (35%). Average LOS was 1.1 days. 8% of the clinically Obese Patients required further Surgery compared to 8.7% in the Non-obese group.

Revision surgery for recurrent discs and Surgery for dural tear repair were the main reasons for return to theatre. Revision rates were comparable between the two Patient groups. LOS was no different for Obese Patients. This study concludes that Obese Patients undergoing One-Level simple Microdiscectomy do not face a significantly higher risk of requiring Revision Surgery in the future.

Introduction

Negative pressure wound therapy (NPWT) and vessel loop assisted closure are two common methods used to assist with the closure of fasciotomy wounds. This retrospective review compares these two methods using a primary outcome measurement of skin graft requirement.

Purpose: Medial opening wedge high tibial osteotomy (MOW-HTO) is a well-described operative method for the treatment of medial gonarthrosis in selected patients. One of the concerns with MOW-HTO is the potential delayed or nonunion across the medial gap. Traditionally, this gap was filled with autograft to facilitate union. Although alternative graft options, such as allograft, are available and have theoretical advantages over autograft, little is known about their efficacy relative to autograft in MOW-HTO. The purpose of our study was to perform a retrospective matched cohort study comparing union, re-operation and complication rates between autograft and morselized allograft as filler for the medial gap created in MOW-HTO.

Method: Forty patients who underwent MOW-HTO for sympathetic varus deformity with the use of autograft bone were matched for age, sex, body mass index, deformity and deformity correction with 40 patients who underwent the same procedure with the use of morselized bone allograft. The operative technique utilized, type of hardware fixation and rehabilitation program were similar for both groups. The primary outcome assessed was union rate as evaluated on radiographs by two independent blinded examiners. Re-operation and complication rates were assessed as secondary outcomes.

Results: A total of 73/80 patients in the study (91%) developed union, 4/80 (5%) developed nonunion, and 3/80 (4%) required early revision. The union rate was 95% and 88% in the autograft and allograft groups respectively. Three percent in the autograft and 8% in the allograft groups developed nonunion (p=0.64). Thirteen percent of the autograft patients required re-operation compared to 18% from the allograft patients (p=0.53). Complications were encountered in 28% of the autograft group and in 23% of the allograft group (p > 0.05). There was a 10% incidence of harvest site complications in the autograft group. The average operative time was 21 minutes shorter using allograft compared with using autograft (p< 0.01).

Conclusion: No statistical significant difference was demonstrated between the groups for union, re-operation rates and overall complication rates. However, the autograft group had a significant 10% incidence of harvest site complications and a statistically significant increased operative time. We conlcude that allograft is safe and efficacious to use in valgus producing MOW-HTO. Allograft avoids harvest site complications and is associated with decreased operative time when compared to autograft.

Background and purpose of study: Intervertebral disc height loss is associated with decreased spinal stability and increased loading on spinal structures, which may be a source of back pain. In the past, total stature change, measured using stadiometry, has often been used as an indication of disc height loss and as an index of the load on the spine. The aim of this study was to use an upright MRI scanner to investigate the changes in lumbar disc dimensions following a short-term loading protocol. It was hypothesized that there would be a linear relationship between the loss in total lumbar disc height and a measure of stature change obtained from a stadiometer.

Method and Results: Thirteen participants with no history of low back pain were recruited. Stadiometer measurements and MRI images of the lumbar spine were obtained both before and after 15-minutes of walking wearing a weighted vest. Contrary to the original hypothesis, no correlation (r = 0.32) was found between total disc height loss measured via MRI and via stadiometry. However a correlation (r = 0.54) was found between stature loss measured on the stadiometer and the decrease in posterior spine length.

Conclusion: The results suggest that stadiometry should not be used to quantify the change in individual disc height or individual disc compression force. However, the correlation with the composite measure of spinal length does offer support to the use of stadiometry to assess the overall effect of loading.

Purpose: To clinically evaluate the medium term outcome of a patient cohort age 55 years or older at the time of medial opening wedge high tibial osteotomy (MOWHTO).

Methods: Between January 1997 and January 2003, 60 patients (52 males) underwent 66 MOWHTOs. Following a systematic chart review 56 returned for follow up. Outcomes measures were KOOS, LEFS, SF-12, Cincinnati, Tegner scores, a new activity score and physical examination. Routine knee and long leg standing radiographs were compared to pre and early postoperative radiographs.

Results: Thirteen patients were not assessed further, 6 (7 MOWHTOs) had undergone total knee arthroplasty (TKA), 3 had passed away and 4 were lost to follow up. Thus the probability of survival (not converting MOWHTO to TKA) was 0.966 at 3 years, 0.927 at 4 years and 0.878 at 5 years. Quality of life, functional status and general health of the remaining 47 patients (52 HTOs) with a mean age of 62 years (55–75) at the time of surgery were assessed. At a mean follow up of 62 months (26–98), on the author’s activity score, 83% performed at least one high impact activity at moderate to high intensity an average of 4–7 times per week and 6% did not participate in any sport. Average participation in activities/sports was 3 per person at a participation level of 4.6 (Tegner). The mean Cincinnati score was 75% (SD=23, 14–95%). Mean scores for the KOOS and LEFS were 66% (SD=22, 7–99%) and 49 (SD=18, 5–80) respectively. Seventy–two percent were fully weight bearing by 3 months. There were 6 revisions for a combination of delayed and non-unions.

Conclusions: MOWHTO remains a viable alternative for patients over the age of 55 with knee osteoarthritis and varus malalignment who would otherwise be candidates for arthroplasty and particularly for those wishing to maintain or regain a high level of activity.

Background and Purpose: The majority of non-specific low back pain is presumed to be mechanical in origin. Many interventions, including manipulation, mobilisation, core strengthening and rigid/motion preserving surgery rely on the premise that intervertebral motion is related to pain in some patients, however, there is no reliable in vivo experimental evidence for this. We compared continuous intervertebral motion from quantitative digital fluoroscopic sequences in asymptomatic controls and patients with chronic non-specific low back pain to investigate associations between pain and intervertebral motion.

Methods: Thirty asymptomatic volunteers and 21 patients with chronic non-specific low back pain underwent passive, controlled, recumbent lateral bending motion during video-fluoroscopic screening. These provided 90 and 44 intervertebral levels from L2-L5 respectively for analysis. Vertebrae were registered digitally and automatically tracked throughout the motion. Inter-vertebral rotation phenotypes for each left-right sequence were obtained and analysed for stiffness (inter-vertebral motion of less than 3o), lax appearance and paradoxical motion. A similar population underwent sEMG studies to determine if muscle activity was present during controlled passive recumbent motion. Associations between pain and stiffness, lax appearance and paradoxical motion were calculated from chi-squared distributions. A subset of patients also had MR scans to assess disc degeneration.

Conclusion: Stiffness was observed significantly more frequently in patients with pain, as was paradoxical motion and lax appearance. sEMG activity was very small throughout motion in both groups. MR degeneration was not associated with stiffness in patients. Results must, however, be regarded as preliminary as greater normative referencing, group matching, more extensive kinematic analysis, flexion-extension, weight-bearing, and clinical outcomes studies are needed.

To examine the effect of gender on outcome of high tibial osteotomy (HTO) for varus gonarthrosis at a minimum two year follow-up

Sixty-five patients (twenty-four female and forty-one male) participated in this investigation. Mean age at the time of surgery was fifty-five years and mean time to follow-up was 54.83 months. Multiple linear regression was used to estimate the strength of the association between post-operative WOMAC osteoarthritis index scores and the independent variables of gender, age, BMI, time (months from surgery) and pre and post operative mechanical axis angles (MAA) measured on standing double-leg hip-to-ankle radiographs.

This analysis revealed that none of the independent variables contributed significantly to the WOMAC outcome scores.

The results of this study indicate that gender is not a significant predictor of outome following medial opening wedge HTO. This is contrary to the view held by many.

The purpose of this study was to determine if there is a relationship between ultrasound measured gap size and functional outcomes in non-operatively treated achilles tendon ruptures.

Patients who presented with complete achilles tendon ruptures were prospectively randomised to operative or non-operative treatment groups and followed over a one year period. The non-operative patients were selected and reassessed at three months, six months and one year. Patients were included if seen within seven days of their injury and had ultrasound confirmation of a complete tear. Non-operative treatment consisted of a functional bracing protocol with an aircast boot. Ultrasound measures included tear location and gap size in neutral, dorsiflexion, and plantar flexion of the ankle. Outcome measures were re-rupture rates, complications, range of motion, calf circumference, strength, and functional outcome scores.

Twenty-five patients were included with complete data. The mean plantar flexion gap was 5.6(+/−7.5mm). The mean dorsiflexion gap was 13.7(+/−12.5mm). Proximal tears were found in 41% of patients, midsubstance in 27%, and distal tears in 32%. At one year follow-up 71% of patients had excellent results with the remaining 29% showing good results. Isokinetic strength, range of motion, and calf circumference measurements were all greater than 90% relative to the contralateral extremity. There were two reruptures and no other complications present. There were no significant relationships between plantar or dorsiflexion gap size and functional outcomes scores or tear location.

Gap size was not significantly related to functional outcomes. Non-operative treatment produced very good results at one year follow-up with low complication rates. These results suggest that ultrasound estimation of gap size and location may be of limited clinical value in the management of achilles tendon ruptures.

The purpose of our study is to determine if hamstring autograft size can be predicted preoperatively. We will define a relationship between patient body size (BMI, height, and weight) and harvested graft size, as well as define a relationship between the preoperative MRI cross-sectional area (CSA) of hamstring tendons and harvested graft size. This information will be useful as a tool for preoperative planning in graft choice selection.

The pre-operative MRIs of one hundred and four patients (62M, 42F) who underwent ACL reconstruction using hamstring autografts were analyzed. Cross-sectional area (CSA) of the ST and G was measured on a single axial MRI image at the level of the knee joint. Combined CSA of both tendons was then compared to the diameter of the four-strand hamstring autograft measured intra-operatively. Patient BMI, height and weight was also compared to intraoperative hamstring autograft size. Linear regression analysis was then performed to define the relationship and predictive value of body size on graft diameter.

Mean graft size was 7.4mm (range 6 – 9). Average graft size for men and women, 7.6mm and 7.1mm, respectively. Predicting graft size from BMI: r= 0.29, R2= 0.08. Predicting graft size from height: r= 0.52, R2= 0.27. Predicting graft size from weight: r= 0.5, R2= 0.25. On preoperative MRI, the mean CSA of ST and G was 9.8mm2 (range 5.4 – 17.7) and 4.5mm2 (range 1.8 – 9.4) respectively, with a total CSA of 14.3mm2 (range 8.4 – 25). If the total CSA was greater than 12mm2, a graft of 7.0mm or greater could be predicted 93% of the time, with sensitivity and specificity, 78% and 76%, respectively, and a LR of 3.25.

Body size is a poor predictor of hamstring graft size in ACL reconstruction, and therefore a large patient does not always provide a large graft from harvested hamstring tendons. MRI assessment of hamstring tendons can be a useful tool for preoperative planning, providing a strong predictive value of graft size from a simple calculation.

Summary Results of this two-group parallel design randomised controlled trial indicated one and two year outcomes following ACL reconstruction were not different in one hundred and fifty patients using either an ACL functional knee brace or neoprene knee sleeve. Introduction: The primary objective of this study was to compare postoperative outcomes in patients using an ACL functional knee brace and patients using a neoprene knee sleeve

One hundred and fifty patients were randomised to receive an ACL functional knee brace (n=76) or a neoprene sleeve (n=74) at their six week postoperative visit following primary ACL reconstruction. Patients were instructed to wear the knee orthosis during participation in all physical activities. Patients were assessed preoperatively, six weeks, six, twelve, eighteen and twenty-four months postoperatively. Outcome measures included disease-specific quality of life (ACL QOL), KT 1000 and single limb forward hop test administered by a blinded research assistant. One and two-year outcomes were compared after adjusting for baseline scores. A priori directional subgroup hypotheses based on time from injury to surgery, pre-operative KT 1000 scores, and one and two-year compliance scores were evaluated using tests for interactions. Analysis was completed on an intention-to-treat basis.

There were no significant between-group differences for any of the outcomes at one and two-year follow-ups. Mean between-group differences at two years were: 2.87% (95% CI: −3.85 – 9.60) for the ACL QOL, 0.07mm (95% CI: −0.80 – 0.93) for KT 1000 side-to-side difference, and 2.64% (95% CI: −4.57 – 9.85) for hop limb symmetry index. There were no significant subgroup findings and adverse events were similar between groups.

Confidence intervals for between-group differences are narrow and exclude clinically important differences. These findings suggest a functional knee brace does not result in superior outcomes over a neoprene sleeve following ACL reconstruction.

Stature change has been used to indicate the stress associated with specific tasks. Interpretation of stature change is often related to the diurnal change found in healthy participants. However, it has not been determined whether individuals with chronic Low Back Pain (LBP) experience a similar diurnal pattern. The aim of this study is to investigate diurnal stature change in individuals with and without CLBP.

Eight participants with LBP and eight matched asymptomatic controls took part in the investigation. Twenty-four stature measurements were made across a 24 hour period using a standing stadiometer. Differences between the two groups were analysed using two-way ANOVAs (time x group). Correlations between stature change and levels of low-back discomfort were examined using Spearman’s rho.

A clear diurnal variation was found for both groups, with the trough to peak variation in stature of 17.9 mm (LBP) and 17.6 mm (control) groups did not differ significantly (P > 0.05). Both groups experienced their greatest stature change in the 1^st hour after rising 31.3% (LBP) and 44.6% (Control) of the total stature change. Towards the end of the day stature in the chronic LBP group reached a plateau while the control group continued to shrink. Between 2pm and 6pm both groups demonstrated a previously unreported recovery of stature. Reasons underlying this finding could be hormonal, behavioural or due to hydration status and require further investigation. A significant correlation was found between low-back discomfort and stature change in the LBP group, whereby when stature was lost greater discomfort was experienced and when stature recovery discomfort decreased.

Measures of lower limb alignment and knee joint load during walking were evaluated before and six months after medial opening wedge high tibial osteotomy (HTO) in ninety-five patients with knee medial compartment osteoarthritis (OA). Full-length standing radiographs were used to calculate the mechanical axis angle, and a gait analysis was performed to calculate the external adduction moment about the knee. Results indicated significant decreases in mechanical axis angle and peak adduction moment. These findings provide an indication of the early success of HTO in reducing the extent of lower limb malalignment and knee joint load during walking.

Medial opening wedge high tibial osteotomy (HTO) is intended to correct lower limb malalignment, resulting in decreased medial knee joint load and improved function. Due to the potential for the amount of alignment correction to change over time after surgery, frequent follow-up evaluations are encouraged.

To evaluate the early changes in lower limb alignment and medial knee joint load experienced during walking after medial opening wedge HTO.

Ninety-five patients (seventy-nine males, sixteen females; age range = 21–76 years; BMI range = 18.0–38.5) with knee joint OA affecting primarily the medial compartment underwent radiographic and gait analyses pre-surgically and six months following HTO. Full-length standing radiographs were obtained on both occasions and used to measure the static mechanical axis angle. Three-dimensional kinetic and kinematic data were also collected and combined to calculate the external knee joint adduction moment, an indirect measure of knee joint load. Paired t-tests indicated the mechanical axis angle (mean decrease = 8.32 degrees, 95% CI = 7.54,9.10) and peak external knee joint adduction moment (mean decrease = 1.61%BW*ht, 95% CI = 1.25,1.95) significantly decreased post-operatively (p< 0.001). These results indicate less varus angulation and reduced medial knee joint load following HTO.

These preliminary findings suggest that medial opening wedge HTO is an effective surgical treatment for improving alignment and reducing knee joint load.

Although these early results are promising, future research is required to determine the long-term success of this surgery in the treatment of knee OA.

Funding:

CIHR, NSERC, Arthrex Inc.

Purpose: Medial Opening Wedge High Tibial Osteotomy (MOWHTO) is a joint preserving procedure of the knee. Currently we understand the anatomical changes occurring in the varus/valgus plane, but our understanding of other anatomical changes are limited. The objective of this study is to determine immediate anatomical changes occurring about the knee following MOWHTO. Our hypothesis is that anatomical changes occur in all planes of motion. More specifically, we hypothesize that posterior tibial slope is increased and patellar height is decreased immediately following the osteotomy.

Methods: This study was prospective in design. Patients with knee OA were evaluated according to strict inclusion and exclusion criteria. Pre-operative clinical assessment, radiographic evaluation, and patient assessment scores were performed. Intraoperatively, patients had radiostereometric analysis (RSA) beads placed in a predetermined pattern. Intraoperative radiographs were taken. The MOWHTO was then performed. A second radiograph was then taken following the osteotomy. The radiographs were analysed using dedicated RSA computer software to determine anatomical changes.

Results: Eleven patients were included in this study. Average age was 50 years. Mean error and condition number were 0.70 and 74 respectively, indicating highly accurate and reliable results. Analysis of the proximal tibia showed an average valgus correction angle of 8.69 degrees. The average osteotomy size was 12.5mm (9–17.5). Posterior tibial slope increased on average by 2.07 degrees (+5.91–−1.56). Analysis of the patella revealed anatomical changes occurred in all planes. However, the only consistent alteration was a decrease in patellar height by an average of 8.16mm (1.79–13.17). Additionally, there was a consistent increase in patellar tendon length by 5.30mm (2.38–7.34).

Conclusions: Using RSA in MOWHTO for the first time, we were able to demonstrate a useful and accurate measurement tool for this procedure. We found there were many immediate anatomical changes following MOWHTO that are inconsistent and not well understood. There were, however, several anatomical changes that remained consistent among all subjects. Patellar height decreased, patellar tendon length increased, and posterior tibial slope demonstrated an average increase.