Introduction

The ability to walk over various surfaces such as cobblestones, slopes or stairs is a very patient centric and clinically meaningful mobility outcome. Current wearable sensors only measure step counts or walking speed regardless of such context relevant for assessing gait function. This study aims to improve deep learning (DL) models to classify surfaces of walking by altering and comparing model features and sensor configurations.

Aim

To find out the usefulness of knee arthroscopy with debridement in patients of 60 years or more.

Long-term implant survivorship in total knee arthroplasty (TKA) depends on the alignment of the tibial and femoral components, as well as on the mechanical alignment of the leg. Computer navigation improves component and limb alignment in TKA compared to the manual technique. However, its use is often associated with an increase in surgical time. We aimed to evaluate the use of adjustable cutting blocks (ACB) in navigated TKA. We hypothesised that the use of ACB would (1) improve tibial and femoral component positioning; (2) improve postoperative mechanical leg alignment; and (3) decrease tourniquet time, when compared to conventional cutting blocks (CCB).

This was a retrospective cohort study of 94 navigated primary TKA. Patients were classified into two groups according to whether the surgery had been performed using ACB or CCB. There were sixty-four patients in the CCB group and 30 patients in the ACB group. Charts were reviewed to obtain the following data: age, gender, body mass index (BMI), tourniquet time and operated side. Pre- and postoperative standing full-leg radiographs and lateral radiographs were reviewed.

Mean coronal femoral alignment for the CCB group was 0.8® varus (SD = 1.95®) and for the ACB group it was 1.1® varus (SD = 1.5®) (P = 0.12). Mean coronal tibial alignment for the CCB group was 0.1® valgus (SD = 1.3®) and for the ACB group it was 0.5® varus (SD = 1.01) (P = 0.15). Sagittal tibial alignment was a mean 0.5® of anterior slope (SD = 2.9®) for the CCB group and 0.7® anterior slope (SD = 2.5®) for the ACB group (P = 0.38).

Preoperatively, the CCB group had a mean mechanical alignment of 1.8® varus (SD = 9.6®), while the ACB group had a mean 1.8® varus (SD = 9.37®) (P = 0.88). After surgery, mechanical leg alignment for the CCB group improved to a mean 0.7® varus (SD = 2.7®) (P = 0.0001), while the ACB group improved to 1.8® varus (SD = 1.7®) (P<0.0001). There was significantly less variability in postoperative mechanical alignment in the ACB group (P = 0.0091).

Mean tourniquet time for the CCB group was 91 minutes (SD = 17.7 minutes). The ACB group a mean tourniquet time of 76 minutes (SD = 16.7 minutes) (P = 0.01). In the multiple linear regression model, the use of an ACB reduced tourniquet time by 16.8 minutes (P = 0.001).

Adjustable cutting blocks for TKA significantly reduced postoperative mechanical alignment variability and tourniquet time compared to conventional navigated instrumentation, while providing equal or better component alignment.

The incidence of hip fractures is rising worldwide. Hip fracture patients with a cardiac murmur have an echocardiogram pre-operatively in our unit. We assessed the impact of obtaining a pre-operative echocardiogram on treatment of such patients, using National Confidential Enquiry into Patient Outcome and death (NCEPOD) report 2001 as gold standard. We undertook a retrospective audit of hip fracture patients (N=349) between 01/06/08 and 01/06/09. 29 patients had pre-operative echocardiogram (echo group). A computer generated randomised sample of 40 patients was generated from N, ‘non-echo’ group. Data was obtained from medical records and the Hospital Information Support System. The groups were compared using Student's t test. Age and gender distribution were similar in both groups. 29 patients had pre-operative echo. The indication for requesting an echocardiogram pre-operatively was an acute cardiac abnormality in 4 cases. 25 patients had echocardiogram for no new cardiac problem. In the latter group, the reason for requesting an echo was a cardiac murmur in 23 patients and extensive cardiac history in 2 cases. A specialist input from the cardiologist was sought in 5 cases. Most patients with aortic valve abnormality had surgery under general anaesthetic. No patient required cardiac surgery or balloon angioplasty pre-operatively. There was a significant delay to surgery in the patients who had a pre-operative echo (average 2.7 days, range 0–6 days) compared to ‘non-echo’ group (average 1.1 days, range 0–3 days), (P< 0.001). There was no significant difference in length of stay and mortality at 28 days between the two groups. We are now developing departmental guidelines for requesting echo in hip fracture patients with cardiac murmur to prevent unnecessary avoidable delay. We are developing a link with the cardiology department to expedite echocardiogram requests in hip fracture patients.

Antibiotic prophylaxis aims to reduce wound and prosthetic infection, with minimal adverse effects. The 3 dose Cefuroxime regime is widely used, despite the risk of infective diarrhoea. We describe the results of single dose intraoperative Gentamicin and Amoxicillin compared to this standard regime.

We retrospectively reviewed 220 patients following hip hemiarthroplasty, creating 2 demographically matched cohorts; Group 1: 3 doses of Cefuroxime (n=113) and Group 2: single dose Gentamicin and Amoxicillin (n=107). End points were evidence of infection, length of stay and Clostridium difficile (CD) rates. results showed a significant reduction in group 2 for average length of stay (17 Vs. 13 days p=0.0432) and CD rates (7/113 Vs 0/107 p=0.0158).

Considering antibiotic therapies administered; significant reductions in group 2 for the number of patients that required post-operative antibiotics (99/113 Vs 73/107 p=0.0005), the median antibiotic DDDs (Defined Daily Doses) in 1st 2 post-operative days (0.25 Vs 0 p=0.0000) and those that received Ciprofloxacin or Cefuroxime post-operatively (82/113 Vs 24/107 p=0.0000). No significant difference was found for median antibiotic DDDs, median antibiotic DDDs from 2nd post-operative day, patients that received Flucloxacillin post-operatively.

Measured microbiological outcomes showed a significant reduction in the number of patients with confirmed growth requiring treatment with antibiotics in group 2 (21/23 Vs 12/22 p=0.0053). No difference was found between number patients with operation site swabbed and those with confirmed microbial growth.

We demonstrate single dose Gentamicin and Amoxicillin significantly reduces length of stay, CD rates and the number of patients requiring post-operative antibiotics for wound infection, inferring a reduction in the rate of wound infection. We would recommend this as an effective alternative to the 3 dose Cefuroxime regime.

Objective: To identify institution specific risk factors for developing MRSA surgical site infection (SSI) and develop an objective mechanism to estimate the probability of MRSA infection in a given patient admitted to the orthopaedic unit.

Design: A cohort study was performed to identify risk factors in all patients who had MRSA infection during admission on the orthopaedic unit between January 2002 and December 2004. Logistic regression was used to model the likelihood of MRSA. A stepwise approach was employed to derive a model. The MRSA prediction tool was developed from the final model.

Results: Of the 11 characteristics included in the logistic regression, the features that strongly predicted a MRSA infection were ASA grade, patient’s residence and reason for admission.

110 had MRSA infection in their surgical wound. 83 of 110 (75.5%) patients were non-elective admissions, of which 49 (60%) were proximal femur fractures. 20% of proximal femur fractures admitted from nursing home and 7.8% from their own homes developed SSI with MRSA. This cohort of SSI with MRSA had an average of 5.7(1–18) previous admissions. 25 (23%) had been previously colonised with MRSA. Majority of them (76%) were between 70–90 years old and were ASA grade 3–4.

Conclusion: Through multivariate modelling technique we were able to identify the most important determinants of patients developing SSI with MRSA in our institute and develop a tool to predict the probability of MRSA in a given patient. This knowledge can be used to guide the use of appropriate prophylactic antibiotic and to take other required measures to avoid the SSI with MRSA.

We have carried out a prospective study comparing the results at five years in patients older than 75 years of age undergoing hydroxyapatite-coated, cementless total knee replacement (TKR) with those who were younger. The Knee Society clinical rating scores were recorded before and after operation. Of 559 patients undergoing TKR, 135 were in the elderly age group. The knee scores at five years or more showed comparable results, with patients under 75 years of age reaching a score of 183 and those aged 75 years or over reaching 174. These differences were predominantly due to the functional component of the score. We conclude that elderly patients do just as well as the younger group using this prosthesis.

Infection is a potentially disastrous complication of total knee replacement (TKR). Retention of the prosthesis has been associated with high rates of persistent infection. Our study shows that in selected situations, arthroscopic debridement may allow retention of the prosthesis and eradication of the infection. However, the prosthesis must be stable, the surgical technique must be meticulous and specific antibiotics must be taken for a lengthy period. Arthroscopic debridement should be considered as an alternative to an open technique, or revision, for the infected TKR.

Although hydroxyapatite (HA) coating is known to enhance fixation in THR, its role in the fixation of Total Knee Replacements is less well appreciated. This study was performed to assess the medium-term results of an HA-coated TKR.

Between August 1992 and 1998 all patients requiring a primary TKR were treated with a hydroxyapatite-coated, PCL-retaining prosthesis implanted by the senior author. The HA coating used was 70 microns thick with 75% crystallinity and 20% porosity. It is deposited on a beaded heat-sintered surface. A combined Hospital for Special Surgery and Knee Society Score was recorded pre-operatively and at three, six, 12, 24 and 60 months post-operatively. Fluoroscopically-controlled interface views were performed on the first 161 knees immediately post-operatively and repeated 24 months postoperatively.

Six hundred and ninety two patients (Male:Female 335:357) with a mean age of 68 years (31–88 years) underwent 1 000 TKR mainly for OA (93%) and inflammatory arthropathies (RA 3%, psoriasis 1%). The mean follow up was 75 months (40–115). There were 461 unilateral (R:L 256:205) and 539 bilateral replacements (462 simultaneous and 77 staged).

The pre-operative knee score was 95/200, ROM 6–115 degrees and at latest review was 182/200, ROM 1–113 degrees.

Forty four patients have died (mean age 73 years, range 54 to 88). There have been 14 deep infections (1.4%), 22 proven pulmonary emboli (2.2%) and five periprosthetic fractures (0.5%). Six revisions have been performed. Visible gaps between bone and implant were present in 91% of femora and 58% of tibiae initially and in 6% of femora and 8% of tibiae at two years on interface views. There have been no cases of clinical loosening.

Currently, this study comprises the largest known series of HA-coated total knee replacements. These results demonstrate that HA appears to enhance fixation of uncemented knee prostheses which maintain good clinical outcomes.