Cannulated hip screws are frequently used in the management of hip fractures. There have been concerns over the failure rate of the technique and the outcomes of those that subsequently require conversion to total hip replacement (THR).

This study utilised a database of over 600 cannulated hip screw (CHS) fixations performed over a 14-year period and followed up for a minimum of one year (1-14). We identified 57 cases where a conversion to THR took place (40 females, 17 males, mean age: 71.2 years). Patient demographics, original mechanism of injury, fracture classification, reason for fixation failure, time until arthroplasty, implant type and post-arthroplasty complications were recorded. Clinical outcomes were measured using the Oxford Hip Score.

The failure rate of cannulated screw treatment was 9.4% and the mean time from initial fixation to arthroplasty was 15.4 (16.5) months. Thirty six fractures were initially undisplaced and 21 were displaced. As one might expect the displaced cases tended to be younger but this didn't reach statistical significance [66.5(14.3) vs 72.7(13.1), p=0.1]. The commonest causes of failure were non-union (25 cases, 44%) and avascular necrosis (17 cases, 30%). Complications after THR consisted of one leg length discrepancy and one peri-prosthetic fracture. The mean Oxford score pre-arthroplasty was 12.2 (8.4), improving to 38.4 (11.1) at one-year. Although the pre op Oxford scores tended to be lower in patients with undisplaced fractures and higher ASA scores, the improvement was the same whatever the pre-op situation. The one-year Oxford score and the improvement in score are comparable to those seen in the literature for THR in general.

In conclusion, CHS has a high success rate and where salvage arthroplasty is required it can provide good clinical outcomes with low complication rates.

Abstract

Summary

The 80% porous structure of trabecular metal allows for bone ingrowth in more than 90% of the available surface. The Nexgen LPS Uncemented Knee using a trabecular metal tibial component has performed well at minimum of 5 years’ follow-up.

The fixation of comminuted femoral fractures with intramedullary nails is commonplace but there remains little work on the mechanical ability of the different diameters of nail available to resist bending. What previous work there is has produced conflicting conclusions. The bending stiffness against the intramedullary nail diameter and the extent of the comminuted fracture is clinically important due to the impact on fracture healing and implant failure.

Intramedullary nails of differing diameters (10 mm, 11 mm and 13 mm) were loaded axially in fourth generation composite femurs with increasing mid shaft bone defects, namely 3cm, 5cm, 8cm and 10cm bones. The loading versus the displacement was recorded for each nail.

A one-way ANOVA analysis demonstrated a significant difference between intramedullary nail diameters and the bending stiffness, with p values of less than 0.012; 3cm mean 12.26 (CI 9.06-15.46) mm, p=0.012; 5 cm mean 10.63 (CI 8.35-12.92) mm, p=<0.001; 8 cm mean 11.04 (CI 8.35-13.74) mm, p=<0.001; 10 cm mean 11.68 (CI 7.86-15.50) mm, p=<0.001. For the 11 mm diameter intramedullary nail, failure occurred at around two times the body weight of an average individual or 1400 to 1800 N. A repeated measure ANOVA analysis of the effect of the increasing bone defect showed a mixed picture, with a significant difference between the 5 cm and 8 cm gap and only a trend towards significance between 5 cm and 10 cm.

Caution should be advised when considering using a cannulated femoral intramedullary nail in a patient with a fracture gap of greater than 5 cm. Further, the mechanical effect of comminuted fractures treated with nails suggests reduced stiffness with increasing length of fracture gap although the picture is complex and explains the divergence of research conclusions.

The reintroduction of hip resurfacing has raised the possibility of whether it could offer a better outcome in sporting and work activity after surgery compared to total hip replacement.

Questionnaires were analysed from 125 total hip replacement (THR) and 108 hip resurfacing (HR) patients regarding participation in sport in the year after their surgery and returning to work they were employed at prior to their surgery. The two groups had similar average age (61 vs 60) and pre-operative Oxford hip scores (41 vs 38).

Seventy-one of one-hundred and twenty-five THR patients compared to 76/108 HR patients participated in sporting activity in the year after their surgery. When including only patients that played sport before their surgery 54/75 THR and 66/83 HR patients returned to same sporting activity level after their surgery. Of the patients that worked before surgery 35/44 THR patients compared to 70/74 HR patients returned work to after their surgery.

There is significant difference quantity of patients participating in sporting activity after HR and THR (fishers exact test, p value=0.04). However there is no significant difference in quantity of patients returning to sporting activity after HR or THR including only patients that played sport before their surgery (fishers exact test, p value=0.35). There is a significant difference in the quantity of patients returning to work activity after HR and THR (fishers exact test, p value= 0.02). HR has a better outcome in patients participating in sport after surgery compared to THR however there is no benefit for patients that are active pre-operatively. More patients return to work after HR than THR.

Our aim in this audit was to determine whether intensive rehabilitation post-operatively influenced length of stay and readmission rates for patients undergoing primary total knee arthroplasty.

In September 2007, a dedicated weekend physiotherapy service was set up in our Trust for patients following joint arthroplasty at a cost of £30,000 per annum. A prospective audit was conducted over two six-month periods, before and after the introduction of this service, including 202 and 240 patients respectively. Patient demographics including ASA grade and strict inclusion and exclusion criteria were used. The effect of anaesthetic type on post-operative pain control was also reviewed. Chi-squared and Mann-Whitney tests were used to analyse non-parametric data.

In the second cohort, with intensive rehabilitation, a statistically significantly higher number of patients were discharged within seven days of admission (64% vs 36%, p<0.01). This was despite there being a significantly higher number of patients with high ASA grades 3-4 in this cohort (37% vs 27%, p<0.05). The median length of stay in the second cohort was seven days compared to eight in the first cohort. There was a slight increase in rate of readmission within the second cohort but this was not statistically significant. We found that the addition of a femoral nerve block significantly reduced post-operative pain.

We concluded that an annual financial saving to the Trust of approximately £118,000 could be made by the addition of an additional dedicated physiotherapist in our unit. Patients can be safely discharged sooner with intensive rehabilitation and may benefit in the longer term by improved knee function.

Background: Long term follow up data on patients following ankle fracture is scarce. As a follow on from a year long prospective audit of patients admitted to a trauma unit data was collected on a cohort of such patients at a minimum of 4 years post injury to ascertain functional outcome.

Methods: All patients with ankle fractures requiring admission to the Royal Preston Hospital in the period August 2004 to August 2005 were identified. Patients with multiple injuries were excluded. One hundred and one patients were confirmed as fulfilling the criteria that all medical notes were present and the patient had a principle injury of a malleolar fracture. Patients were then invited to a follow up clinic. Functional outcome relating to work and leisure pursuits, the American Orthopaedic Foot and Ankle Society hindfoot score (AOFAS) and a Visual Analogue Scale for residual pain were recorded.

Results: Utilising the Weber classification there were 63% B, 24% C fractures and 5% A fractures. 91 patients underwent surgical fixation. The most common post hospital discharge complication was excessive swelling and 17 patients’ required additional surgery. The only factor that predicted length of follow up before discharge was the presence of diabetes. The Weber classification had no predictive value for length of follow up. 90% of patients returned to their previous work. All ankle fractures had a significant impact on social activities, 45% with a Weber C fracture patients had not returned to their previous sporting activities. The median AOFAS score was 85/100. The median VAS pain score was 9 out of 100. Fifty-eight patients had a change to the type of footwear tolerated.

Conclusion: Patients with an ankle fracture requiring admission to hospital have significant residual symptoms at a minimum four years post injury. Weber B and C fractures have significant long term effects on ADL.

Introduction: Hip resurfacing has been promoted as a procedure that results in a better outcome in sporting and work activity after surgery compared to total hip replacement (THR). Recently more standard THRs have offered the same large metal on metal joint articulation but using a standard stem.

Method: Questionnaires were analysed from 125 metal on metal total hip replacement (THR) and 108 hip resurfacing (HR) patients regarding participation in sport and returning to work at a minimum of a year after surgery.

Results: The two groups had similar mean age (61 vs 60) and pre-operative Oxford hip scores (41 vs 38). Seventy-one of 125 THR (57%) patients compared to 76 of 108 (70%) HR patients participated in sporting activity in the year after their surgery (fishers exact test, p value=0.04). When including only patients that played sport before their surgery 54 of 75 (72%) THR and 66 of 83 (80%) HR patients returned to same sporting activity level after their surgery (fishers exact test, p value=0.35). Of the patients that worked before surgery 35 of 44 (80%) THR patients compared to 70 of 74 (95%) HR patients returned work to after their surgery (fishers exact test, p value= 0.02).

Conclusion: There was no difference in the proportion of patients who played sport prior to their surgery returning to sport. After hip resurfacing however more people took up a sporting activity and at a year post surgery a greater number of patients were taking part in sport after a hip resurfacing. Patients with a hip resurfacing were more likely to return to work after surgery.

Patients overestimate pain following hip and knee replacement.

Ninety two patients awaiting hip or knee replacement were asked at their pre-operative assessment to estimate the level of pain they expected following their surgery on a 10cm visual analogue scale. Note was made of their age, gender, previous surgeries, Amsterdam anxiety score as regards the anaesthetic and surgery and an information score relating to their anaesthetic and surgery. Seventy nine patients had pain scores collected on a daily basis post surgery.

Mean (std dev) age of the group was 68 (11) years and with a female to male ratio of 1.57. Females were significantly more anxious about the surgery than males (t-test, p< 0.007). Patients were more anxious about the anaesthetic and the surgery with hip replacement compared to knee replacement although this did not reach significance (t-test p=0.07). The mean (std dev) pain score pre-operatively was 7.5 (1.6). The mean (std dev) pain score expected was 7.0 (2.2) on the first post operative day and 4.3 (2.2) on the sixth post operative day. Forty four per cent of patients expected to have pain greater than their arthritis pain on the day following surgery.

The level of pain experienced post-operatively was significantly lower than expected. Mean (std dev) pain score was 5.1 (2.7) on day 1 post op and 3.3 (2.4) on day 6 (t-test, p< 0.05 for both). There was no correlation between age, gender, number of previous surgeries, anxiety or information scores and the expected level of pain.

The majority of patients, whatever their age, gender or level of anxiety over estimate their level of post-operative pain after joint replacement. Studies are needed to assess whether educating patients about pain post surgery will be of benefit, particularly in their early rehabilitation.

In patients with an ankle fracture initial delay to operation because of time constraints is often prolonged because swelling precludes surgery for some days. We made use of a year long prospective audit of 2000 trauma patients to analyse the effect of delay to surgery on length of stay in ankle fracture patients.

One hundred and fifty patients were admitted with an ankle fracture. One hundred and twenty nine were operated on. The median (inter quartile range) time to surgery was 3 (2–5) days. Twenty six patients got to theatre within 24 hours. For those who didn’t get to theatre within 24 hours the median time to surgery was 4 days.

For the group as a whole there was a poor correlation between wait for surgery and length of stay (Pearson = 0.6). For the 98 patients under the age of 60 there was a significant relationship (Pearson co-efficient = 0.85). Fifty per cent of those under 60 were discharged within 48 hours of their surgery. The number of co-morbidities was different between the under and over 60s. The over 60s had a median (inter quartile range) of 2 (1–5) co-morbidities, compared to 0 (0–1) in those under 60.

Patients under 60 with an ankle fracture are generally medically fit. If 90% of such patients had their fractures fixed within 24 hours the median post operative length of stay for all ankle fractures in this population would fall from 7 to 3 days and the number of bed days saved would be 400 a year. The length of stay in patients over the age of 60 is more related to their associated co-morbidities than their time to surgery.

A prospective audit was carried out to analyse the relationship between time to surgery, number of co-morbidities and length of stay in 357 consecutive patients operated on for a fractured neck of femur.

One hundred and thirty five patients were operated on within 48 hours (group 1), 129 between 48 and 96 hours (group 2) and 93 patients after 96 hours (group 3). The mean (std dev) age was 77.2 (12.5) years in group 1, 79.8 (9.9) years in group 2 and 79.2 (9.4) in group 3. There were 93 (69%) females in group 1, 99 (77%) in group 2 and 67 (72%) in group 3. The number (%) admitted from home was 85 (63) in group 1, 81 (63) in group 2 and 73 (79) in group 3.

In the 30 patients with no co-morbidities there was a strong relationship between wait for surgery and length of stay. In these patients the median length of stay increased from 8.5 days in group 1 to 21 days when in group 3. In the 187 patients with one or two co-morbidities the relationship was present but weaker. The median length of stay increased from 16 days in group 1 to 21 days when in group 3. In the 140 patients with 3 or more co-morbidities there was no relationship between wait for surgery and length of stay. Median length of stay was 23 days in group 1 and 21 days in group 3.

This data from a large consecutive group of patients suggests that the fit patient with a hip fracture benefits from early surgery with a shorter length of stay. Those with multiple co-morbidities have their length of stay determined by their medical condition.

Elevated plasma levels of D-dimer have been found to be a useful screening tool in the diagnosis of deep venous thrombosis (DVT) in the general population. In the post operative setting however their role is less clear. The majority of NHS trusts use D-dimer as a prerequisite test prior to radiological imaging to diagnose DVT.

Aims and method: This study evaluates the effectiveness of D-dimer as a screening tool for DVT in the postoperative period following total hip and knee arthroplasty.

Plasma D-dimer levels were measured pre operatively and on post operative days 1, 3, 5, and 7 in 78 patients undergoing primary total hip or knee arthroplasty. On day 7 patients underwent bilateral duplex ultrasound scanning in order to confirm the absence of DVT. All patients wore pneumatic foot pumps for DVT prophylaxis. Chemical thromboprophylaxis was not used.

Results: D-dimer levels in the post operative period were characterized by a double peak, on days 1 and 7. Mean day 1 value 3.63 (sd=2.72), mean day 7 value 2.83 (sd=1.58). Mean values on days 3 and 5 were 2.52 (sd=2.26) and 2.45 (sd=1.41)

Comparing D-dimer levels between hip and knee arthroplasty we found that both groups displayed the same trend in post operative D-dimer levels; however levels were significantly higher following knee replacement.

We compared D-dimer levels of these patients with a second group of 43 patients who had a confirmed DVT following hip or knee arthroplasty. The mean D-dimer level in this group was 2.20 (sd=0.98 or range 0.80 – 4.46). This group was subdivided into two groups, those with D-dimer samples before day 8 and those after. We found a significant difference between the groups (p=0.01). Mean < day 8 = 2.70. Mean ³ day 7 = 1.97.

The group of patients with Confirmed DVT before day 8 were compared with those free of clot. There was no significant difference found between the D-dimer levels of the two groups. (p=0.37).

Conclusion: The D-dimer level is never normal (< 0.4mg/l), in the week following total hip or knee replacement and so cannot exclude a DVT. The level it rises to is indistinguishable form that seen in the population with a DVT and so cannot identify those patients in whom further investigation is warranted. Requesting a D-dimer test in this population wastes time and resources and is of no benefit.