Background & purpose

Measurement inconsistency across clinical trials is tackled by the development of a core outcome measurement set. Four core outcome domains were recommended for clinical trials in patients with non-specific LBP (nsLBP): physical functioning, pain intensity, health-related quality of life (HRQoL), and number of deaths. This study aimed to reach consensus on core instruments to measure the first three domains.

Introduction: The Corail stem is a well proven femoral implant used for the past 22 years. It is the most common uncemented femoral stem used for total hip replacements in the UK. The stem was modified in 2004 with an increased neck taper to allow for an increased range of bearings and modular heads. This study reviews a series of primary total hip replacements using this recently modified Corail stem to assess if this implant is still performing to acceptable standards.

Method: A prospective patient database collated by 2 arthroplasty surgeons recorded data at the time of operation and subsequent follow up. All intra-operative and post-operative complications were recorded. Pre and postoperative oxford hip scores were analysed.

Results: 751 cases were reviewed. The average age was 63 with females accounting for 69%. The pinnacle cup was used in 83% of cases, with a polyethylene bearing in 48%. Survival of the stem at 3 years was 99.9% (1 periprosthetic fracture following a fall), the cup 99.6%, with overall survival of 99.5%. The most common intra operative complication was calcar fracture occurring in 0.9%. Dislocation occurred in 0.5%, subsidence in 0.3%, deep infection in 0.1% and leg length discrepancy requiring shoe raise in 0.1%. Average 3 year oxford hip score was 12.

Discussion: 3 year survival of both the femoral stem and the total hip replacement are above the quoted rates in the National Joint Registry’s 4th annual report for corail and uncemented stems (98.8% and 98.1% respectively), and also exceeds that of cemented stems (99.1%). The same report quotes similar rates of calcar fractures (0.8%), although we recorded no other perioperative complications. We conclude the new generation of Corail stem has excellent 3 year performance.

Metal-on-metal hip resurfacing is increasingly common. Patients suitable for hip resurfacing are often young, more active, may be in employment and may have bilateral disease. One-stage bilateral total hip replacement has been demonstrated to be as safe as a two-stage procedure and more cost effective. The aim of this study was to compare the in-patient events, outcome and survival in patients undergoing one-stage resurfacing with a two-stage procedure less than one-year apart.

Methods. Between July 1994 and August 2006 a consecutive series of 93 patients underwent bilateral hip resurfacing within a year. 34 patients in the one-stage group. 44 patients in the two-stage group. The age, gender, diagnosis, ASA grade, total operative time, blood transfusion requirements, medical complication, surgical complications, length of stay, duration of treatment, revision and Oxford hip scores were recorded.

Results. There were no significant differences in age, gender, ASA grade between the one-stage and the two-stage. There were 4 minor complications in the one stage group and 5 in the two-stage group. All patients that suffered a complication made a full recovery. There was no significant difference in the blood transfusion requirements. The mean anaesthetic time was 136 minutes in the one stage group and 92 minutes in the two-stage group with a significant mean difference of 44 minutes(95% c.i. 31–52). The mean total length of hospital stay was 11 days in the one-stage group and 16 days in the two-stage group with a significant mean difference of 5 days(95\% c.i. 4.0–6.9). The mean difference in length of treatment time of 6.5 months was significant(95\% c.i. 4.0–9.0).

No patients have undergone a revision procedure during the study period and no patient is awaiting revision surgery.

Conclusions. This study demonstrates no detrimental effects when performing a one-stage bilateral metal-on-metal hip resurfacing in comparison to a two-stage procedure. There are advantages of a one-stage procedure over a two-stage procedure for bilateral disease. Total hospital stay is reduced by 31.3% and the mean length of treatment is reduced by 50.0%. These benefits do not appear to come at the cost of increase complications. The complication rate in both groups was very low and all of the complications were short-term and are unlikely to have any bearing on the longevity of the prosthesis.

We wished to estimate the incidence of surgical-site infection (SSI) after total hip replacement (THR) and hemiarthroplasty and its strength of association with major risk factors. The SSI surveillance service prospectively gathered clinical, operative and infection data on inpatients from 102 hospitals in England during a four-year period.

The overall incidence of SSI was 2.23% for 16 291 THRs, 4.97% for 5769 hemiarthroplasty procedures, 3.68% for 2550 revision THRs and 7.6% for 198 revision hemiarthroplasties. Staphylococcus aureus was identified in 50% of SSIs; 59% of these isolates were methicillin-resistant (MRSA). In the single variable analysis of THRs, age, female gender, American Society of Anesthesiologists (ASA) score, body mass index, trauma, duration of operation and pre-operative stay were significantly associated with the risk of SSI (p < 0.05). For hemiarthroplasty, the ASA score and age were significant factors. In revision THRs male gender, ASA score, trauma, wound class, duration of operation and pre-operative stay were significant risk factors. The median time to detection of SSI was eight days for superficial incisional, 11 days for deep incisional and 11 days for joint/bone infections. For each procedure the mean length of stay doubled for patients with SSI. The multivariate analysis identified age group, trauma, duration of operation and ASA score as significant, independent risk factors for SSI. There was significant interhospital variation in the rates of SSI. MRSA was the most common pathogen to cause SSI in hip arthroplasty, especially in patients undergoing hemiarthroplasty, but coagulase-negative Staph. aureus may be more important in deep infections involving the joint.

There is an increasing interest amongst surgeons and demand from patients for hip resurfacing. One concern regarding resurfacing is the incidence of femoral neck fracture post operatively. McMinn and Treacy report an incidence of 0.4% in their series, our finding was of an incidence of over four times as high (1.9%). We looked at our database of hip resurfacings and tried to identify the risk factors for fracture.

We identified 11 fractures and compared these with 22 controls selected by choosing the cases performed by the surgeon immediately before and after the fracture case. We analysed their medical notes and x-rays. Statistical analysis was performed using a package in ™Excel. The implants were either Birmingham Hip (Midland Medical Technologies) or Cormet (Corin) resurfacings.

No statistically significant correlation was found for sex, age or body mass index. We found that fracture was twice as likely in the presence of possible or probable osteopenia. We did not find that fracture was more likely to occur in patients with a previous diagnosis of Perthes, DDH, SUFE and avascular necrosis (AVN).

We found patients with a superior overhang of the femoral component on the neck did not risk fracture, however we could not demonstrate that notching in itself increased the risk of fracture.

There was no correlation with neck-shaft and stem-shaft angle or neck lengthening and offset and subsequent neck fracture.

In 13 bilateral cases there was fracture in 3 (incidence 23%). Apart from one fracture that occurred at 18 weeks post-operatively all the others occurred before eight weeks. Five fractures occurred in patients who subsequently on histological analysis were found to have avascular necrosis.

We conclude that bilateral surgery is probably unwise. That a superior overhang seems to protect against fracture as long as this is not at the expense of creating an inferior notch. Finally, we find AVN in a number of retrieved heads, what is the true incidence of AVN and does the approach adopted cause the avascular process and if so why do we see so few fractures?

Aims: Data collected on knee replacements from 93 hospitals in England were analysed to identify risk factors for surgical site infection. Methods: Prospective surveillance data collected from hospitals in England to calculate surgical site infection rates and potential risk factors Results: There were 242 (1.6%) infections in 15427 primary TKR, with a 0.11% joint infection rate, and 36 (3.6%) infections in 988 revisions, with a signiþcantly higher joint infection rate of 0.35%. There was considerable variation between hospitals. Multivariable logistic regression found signiþcant association between risk of SSI and type of procedure (p< 0.01), the hospital where the procedure was performed, male sex (p< 0.001), age (p< 0.001) and wound class (p< 0.05). The mean length of stay in primary TKRñs increased from 9 days to 18 days with an infection; and in revision procedures from 12 to 24 days. The median time to diagnosis for SSI was 7.5 days. Staphylococcus aureus accounted for 33%, 66% of which were methicillin resistant (MRSA). Conclusions: There is signiþcant inter-hospital variation in the incidence of SSI following knee replacements in England. Signiþcant risk factors include revision procedures. Male sex, age and wound class. SSIñs doubled the length of post-operative stay and MRSA accounted for 21% of organisms.

Aims: To calculate SSI rates and potential risk factors for primary total hip replacements (THR), hip hemiarthroplasties (HH), revision THR’s, and revision HH’s in England. Methods: Demographic, operative, and infection data was collected prospectively from 104 hospitals in England over 4 years to calculate SSI rates and potential risk factors. Results: There were 353 (2.3%) infections in 15697 THR’s with a 0.2% joint infection rate; 248 (4.6%) infections in 5456 HH procedures (0.9% joint). For revision THRs there were 92 (3.6%) infections in 2563 procedures, and 11 (5.6%) infections in 197 revision HH’s. Staphylococcus Aureus was identified in 52%; 58% were MRSA. With multivariable analysis, only inter-hospital variation (p< 0.001) and ASA score (p< 0.001) remained significant. Mean time to detection of infection varied from 9.2 days (superficial) to 11.3 days (joint). Mean length of stay increased from 9 to 14 days in THR’s; from 14 to 30 days for revision THR’s; from 19 to 34 days for HH’s and from 20 to 28 days for revision HH’s with an infection.

Conclusions: Infection rates are within acceptable levels, however there is a significant inter-hospital variation in infections following hip prosthesis in England. ASA score remains a significant risk factor and MRSA accounted for 30% of organisms.

Data collected on total knee replacements (TKR) from 77 hospitals in England were analysed to identify risk factors for surgical site infection (SSI).

Demographic, operative, and infection data were collected prospectively over a four-year period by the Nosocomial Infection National Surveillance Scheme.

There were 213 (1.8%) infections reported in 11552 primary TKR of which 82% were superficial, 10% deep incisional, and 8% joint/bone infections. The incidence of SSI in 687 revision of TKRs was 4.1% (71% superficial incisional, 18% deep incisional and 11% joint/bone). In the single variable analysis of primary TKRs, significant risk factors were male sex (p< 0.01), age (p< 0.001), ASA score (p< 0.001), wound class (p< 0.001) and NNIS risk index (p< 0.001). In revision of TKRs, only age (p< 0.01) and pre-operative hospital stay of more than one day (p< 0.02) were found to be significant. Significant risk factors with multi-variable logistic regression were type of procedure (TKR or revision TKR), hospital where the procedure was performed, male sex, and age. The mean length of stay in primary TKRs was 10 days (19 days with SSI) and 12 days in revision TKR (22 days with SSI). The median time to diagnosis for superficial SSI was 7 days for superficial SSIs, 9 days for deep incisional SSIs and 7.5 days for joint/bone infections. Staphylococcus aureus accounted for 35% of the infections and nearly one third of these were methicillin resistant (MRSA).

There is significant inter-hospital variation in the incidence of SSI following total knee replacement. Revision TKR procedures are associated with a significantly higher incidence of SSI than primary TKRs (p< 0.001). Male sex and age are also important risk factors. Patients with SSI had a length of post-operative stay approximately twice that of those without SSI.