P. Walmsley

A prospective, randomised, controlled trial of the use of drains in total hip arthroplasty

The routine use of surgical drains in total hip arthroplasty remains controversial. They have not been shown to decrease the rate of wound infection significantly and can provide a retrograde route for it. Their use does not reduce the size or incidence of post-operative wound haematomas. This prospective, randomised study was designed to evaluate the role of drains in routine total hip arthroplasty. We investigated 552 patients (577 hips) undergoing unilateral or bilateral total hip arthroplasty who had been randomised to either having a drain for 24 hours or not having a drain. All patients followed standardised pre-, intra-, and post-operative regimes and were independently assessed using the Harris hip score before operation and at six, 18 and 36 months follow-up. The rate of superficial and deep infection was 2.9% and 0.4%, respectively, in the drained group and 4.8% and 0.7%, respectively in the undrained group. One patient in the undrained group had a haematoma which did not require drainage or transfusion. The rate of transfusion after operation in the drained group was significantly higher than for undrained procedures (p < 0.042). The use of a drain did not influence the post-operative levels of haemoglobin, the revision rates, Harris hip scores, the length of hospital stay or the incidence of thromboembolism. We conclude that drains provide no clear advantage at total hip arthroplasty, represent an additional cost, and expose patients to a higher risk of transfusion.

Delay increases the need for open reduction of type-III supracondylar fractures of the humerus

Recent reports have suggested that a delay in the management of type-III supracondylar fractures of the humerus does not affect the outcome. In this retrospective study we examined whether the timing of surgery affected peri-operative complications, or the need for open reduction. There were 171 children with a closed type-III supracondylar fracture of the humerus and no vascular compromise in our study. They were divided into two groups: those treated less than eight hours from presentation to the Accident and Emergency Department (126 children), and those treated more than eight hours from presentation (45 children). There were no differences in the rate of complications between the groups, but children waiting more than eight hours for reduction were more likely to undergo an open reduction (33.3% vs 11.2%, p < 0.05) and there was a weak correlation (p = 0.062) between delay in surgery and length of operating time. Consequently, we would still recommend treating these injuries at the earliest opportunity.

Does obesity influence clinical outcome at nine years following total knee replacement

A total of 445 consecutive primary total knee replacements (TKRs) were followed up prospectively at six and 18 months and three, six and nine years. Patients were divided into two groups: non-obese (body mass index (BMI) < 30 kg/m(2)) and obese (BMI ≥ 30 kg/m(2)). The obese group was subdivided into mildly obese (BMI 30 to 35 kg/m(2)) and highly obese (BMI ≥xa035 kg/m(2)) in order to determine the effects of increasing obesity on outcome. The clinical data analysed included the Knee Society score, peri-operative complications and implant survival. There was no difference in the overall complication rates or implant survival between the two groups. Obesity appears to have a small but significant adverse effect on clinical outcome, with highly obese patients showing lower function scores than non-obese patients. However, significant improvements in outcome are sustained in all groups nine years after TKR. Given the substantial, sustainable relief of symptoms after TKR and the low peri-operative complication and revision rates in these two groups, we have found no reason to limit access to TKR in obese patients.

Fractures of the tibial spine: epidemiology and outcome.

We documented functional outcome in 83 knees with tibial spine fractures. The mean age at injury was 35 years. There was a medial collateral ligament sprain in 17 knees and posterolateral corner injury in three knees. Twenty patients with displaced tibial spine fractures were treated with fixation of the tibial spine and 63 patients with undisplaced or minimally displaced fractures were treated non-operatively. Fourteen (22%) non-operatively treated knees developed symptomatic instability, three of which underwent ACL reconstruction. Tibial spine fixation restored stability in 18 of 20 knees, but knee stiffness was more common in this group when compared to non-operatively treated knees (60% vs 19%, p<0.0005). Patients with postoperative knee stiffness had a mean age of 28 years compared to 18 in patients with no knee stiffness (p<0.05). We concluded that tibial spine fracture in skeletally mature patients is associated with a significant risk of knee stiffness and instability.

Ten-year survival of cemented total knee replacement in patients aged less than 55 years

We report the ten-year survival of a cemented total knee replacement (TKR) in patients aged < 55 years at the time of surgery, and compare the functional outcome with that of patients aged > 55 years. The data were collected prospectively and analysed using Kaplan-Meier survival statistics, with revision for any reason, or death, as the endpoint. A total of 203xa0patients aged < 55 years were identified. Four had moved out of the area and were excluded, leaving a total of 221 TKRs in 199 patients for analysis (101 men and 98 women, mean age 50.6 years (28 to 55)); 171 patients had osteoarthritis and 28 had inflammatory arthritis. Four patients required revision and four died. The ten-year survival using revision as the endpoint was 98.2% (95% confidence interval 94.6 to 99.4). Based on the Oxford knee scores at five and ten years, the rate of dissatisfaction was 18% and 21%, respectively. This was no worse in the patients aged < 55 years than in patients aged > 55 years. These results demonstrate that the cemented PFC Sigma knee has an excellent survival rate in patients aged < 55 ten years post-operatively, with clinical outcomes similar to those of an older group. We conclude that TKR should not be withheld from patients on the basis of age.

Ten-year results of the Press Fit Condylar Sigma total knee replacement

We report ten-year clinical and radiological follow-up data for the Sigma Press Fit Condylar total knee replacement system (Sigma PFC TKR). Between October 1998 and October 1999 a total of 235 consecutive PFC Sigma TKRs were carried out in 203 patients. Patients were seen at a specialist nurse-led clinic seven to ten days before admission and at six and 18 months, three, five and eight to ten years after surgery. Data were recorded prospectively at each clinic visit. Radiographs were obtained at the five- and eight- to ten-year follow-up appointments. Of the 203 patients, 147 (171 knees) were alive at ten years and 12 were lost to follow-up. A total of eight knees (3.4%) were revised, five for infection and three to change the polyethylene insert. The survival at ten years with an endpoint of revision for any reason was 95.9%, and with an endpoint of revision for aseptic failure was 98.7%. The mean American Knee Society Score (AKSS) was 79 (10 to 99) at eight to ten years, compared with 31 (2 to 62) pre-operatively. Of 109 knee with radiographs reviewed, 47 knees had radiolucent lines but none showed evidence of loosening.

Reduction of blood transfusion rates in unilateral total knee arthroplasty by the introduction of a simple blood transfusion protocol

We prospectively studied blood transfusion practices within a single institution before and after the introduction of a blood transfusion protocol in consecutive patients undergoing unilateral total knee arthroplasty. Data were collected on 393 patients (group I) prior to and 295 patients (group II) after the introduction of the protocol. Following the introduction of the protocol, patients with preoperative haemoglobin of less than 11 g/dl were cross-matched prior to surgery. The criterion for postoperative transfusion was postoperative haemoglobin of less than 8.5 g/dl or a symptomatic patient with haemoglobin of greater than 8.5 g/dl. This change in practice reduced the transfusion rates from 31% in group I to 11.9% in group II. It reduced the non-utilisation of blood from 64 to 1%. There were no adverse outcomes related to the introduction of the protocol.

Predictors of mortality after total knee replacement: A ten-year survivorship analysis

We report the general mortality rate after totalnknee replacement and identify independent predictors of survival. Wenstudied 2428 patients: there were 1127 men (46%) and 1301 (54%)nwomen with a mean age of 69.3 years (28 to 94). Patients were allocatedna predicted life expectancy based on their age and gender. There were 223 deaths during the study period. This representednan overall survivorship of 99% (95% confidence interval (CI) 98nto 99) at one year, 90% (95% CI 89 to 92) at five years, and 84%n(95% CI 82 to 86) at ten years. There was no difference in survivalnby gender. A greater mortality rate was associated with increasingnage (p < 0.001), American Society of Anesthesiologists (ASA)ngrade (p < 0.001), smoking (p < 0.001), body mass index (BMI)n 2 (p < 0.001) and rheumatoid arthritisn(p < 0.001). Multivariate modelling confirmed the independentneffect of age, ASA grade, BMI, and rheumatoid disease on mortality.nBased on the predicted average mortality, 114 patients were predictednto have died, whereas 217xa0actually died. This resulted in an overallnexcess standardised mortality ratio of 1.90. Patient mortality afternTKR is predicted by their demographics: these could be used to assignnan individual mortality risk after surgery.We report the general mortality rate after total knee replacement and identify independent predictors of survival. We studied 2428 patients: there were 1127 men (46%) and 1301 (54%) women with a mean age of 69.3 years (28 to 94). Patients were allocated a predicted life expectancy based on their age and gender. There were 223 deaths during the study period. This represented an overall survivorship of 99% (95% confidence interval (CI) 98 to 99) at one year, 90% (95% CI 89 to 92) at five years, and 84% (95% CI 82 to 86) at ten years. There was no difference in survival by gender. A greater mortality rate was associated with increasing age (p < 0.001), American Society of Anesthesiologists (ASA) grade (p < 0.001), smoking (p < 0.001), body mass index (BMI) <xa020xa0kg/m(2) (p < 0.001) and rheumatoid arthritis (p < 0.001). Multivariate modelling confirmed the independent effect of age, ASA grade, BMI, and rheumatoid disease on mortality. Based on the predicted average mortality, 114 patients were predicted to have died, whereas 217xa0actually died. This resulted in an overall excess standardised mortality ratio of 1.90. Patient mortality after TKR is predicted by their demographics: these could be used to assign an individual mortality risk after surgery.

The pre-operative levels of haemoglobin in the blood can be used to predict the risk of allogenic blood transfusion after total knee arthroplasty

AIMSnThe pre-operative level of haemoglobin is the strongest predictor of the peri-operative requirement for blood transfusion after total knee arthroplasty (TKA). There are, however, no studies reporting a value that could be considered to be appropriate pre-operatively. This study aimed to identify threshold pre-operative levels of haemoglobin that would predict the requirement for blood transfusion in patients who undergo TKA.nnnPATIENTS AND METHODSnAnalysis of receiver operator characteristic (ROC) curves of 2284 consecutive patients undergoing unilateral TKA was used to determine gender specific thresholds predicting peri-operative transfusion with the highest combined sensitivity and specificity (area under ROC curve 0.79 for males; 0.78 for females).nnnRESULTSnThreshold levels of 13.75 g/dl for males and 12.75 g/dl for females were identified. The rates of transfusion in males and females, respectively above these levels were 3.37% and 7.11%, while below these levels, they were 16.13% and 28.17%. Pre-operative anaemia increased the rate of transfusion by 6.38 times in males and 6.27 times in females. Blood transfusion was associated with an increased incidence of early post-operative confusion (odds ratio (OR) = 3.44), cardiac arrhythmia (OR = 5.90), urinary catheterisation (OR = 1.60), the incidence of deep infection (OR = 4.03) and mortality (OR = 2.35) one year post-operatively, and increased length of stay (eight days vs six days, p < 0.001).nnnCONCLUSIONnUncorrected low pre-operative levels of haemoglobin put patients at potentially modifiable risk and attempts should be made to correct this before TKA. Target thresholds for the levels of haemoglobin pre-operatively in males and females are proposed.nnnTAKE HOME MESSAGEnLow pre-operative haemoglobin levels put patients at unnecessary risk and should be corrected prior to surgery.

Changing trends in total knee replacement

IntroductionThis study evaluates a possible change in the demographics and surgical practice observed in a large cohort of patients undergoing total knee replacement (TKR).Patients and methodsWe performed a retrospective analysis of a prospectively collected data on two groups of consecutive patients undergoing primary TKR. Group one consisted of patients who underwent surgery between 1994 and 1998. Group two consisted of patients who had surgery between 2009 and 2012.ResultsThe mean age of group two was significantly greater than that of group one: 68.9xa0years (68.1–69.7xa0years) for group one versus 70.1xa0years (69.6–70.6xa0years) for group two (pxa0=xa00.009). The mean BMI of group two was significantly greater than that of group one: 29.5xa0kg/m2 (29.0–29.9xa0kg/m2) for group one versus 32.0xa0kg/m2 (31.7–32.3xa0kg/m2) for group two (pxa0<xa00.001). The mean pain component of the AKSS was significantly worse in group one than in group two: 28.6 (27.2–30.0) for group one versus 35.5 (34.6–36.4) for group two (pxa0<xa00.001). The mean function component of the AKSS was significantly worse in group one than in group two: 48.6 (47.3–49.9) for group one versus 51.5 (50.7–52.3) for group two (pxa0<xa00.001).ConclusionThis study describes the change in demographics of patients undergoing TKR in our institution over the last two decades.