Despite widespread use, the benefit of knee arthroscopy for symptomatic osteoarthritis (OA) remains controversial. The theoretical benefit of removal of particulate debris and washout of inflammatory cytokines has not been supported by strong evidence. Arguments exist for its short term benefit in well selected patients. We sought to determine if arthroscopy provided any short term symptomatic relief in patients with a clinical diagnosis of OA in our unit.

A total of 20 patients were listed for routine arthroscopy over a one year period for OA. Mean age was 60 (range 48–74) years and 3 in 5 patients were female. 9 patients were listed by registrars, 6 by locum consultants and 5 by substantive consultants. One procedure was cancelled on the day of surgery due to lack of indication, with 19 knees proceeding to surgery. There was evidence of significant arthritis in 17 knees, 6 of which had associated degenerate meniscus tears. Two knees had meniscus tears without significant arthritis. All patients had washout and debridement and in addition, 8 partial menisectomies were carried out together with 3 loose body removals. Patients were followed up after an average of 12 weeks. The 2 patients (both male, mean age 52) with meniscus tears in the absence of significant arthritis fully recovered. Both had symptoms of true locking. 2 patients with loose bodies also fully recovered. With the exception of 2 patients with partial relief, the remainder had no symptomatic relief. One reported a worsening of symptoms and progressed to total knee arthroplasty.

These results suggest that arthroscopic debridement and washout plays a limited role in the short term symptomatic relief of OA. Surgeons should limit its use to younger patients with mild radiographic disease and true mechanical symptoms who are otherwise unsuitable for arthroplasty and not keen on undergoing joint conserving surgery.

Magnetic resonance imaging (MRI) is a useful diagnostic tool in evaluating meniscus pathology in the knee. Data from available literature suggests sensitivity and specificity rates around 90% when compared to the gold standard findings at knee arthroscopy. We sought to evaluate the sensitivity, specificity and precision rate (positive predictive value) of MRI at diagnosing meniscus tears within our unit.

A retrospective audit of a total of 79 MRI reports and arthroscopic findings spanning a one year period was carried out. There were 66 positive MRI reports and 13 negative reports. There were 6 false positives 4 false negatives when compared to arthroscopic findings. The sensitivity of MRI for detecting meniscus tears was 93.7% with 60 out of 64 tears detected. All 4 false negatives also had at least grade III osteoarthritic changes at arthroscopy. Specificity was rather low at 60% with MRI reporting 6 tears (false positives) out of 15 patients who had no tears found at arthroscopy. The positive predictive value (precision rate) of MRI detecting tears was 90.9%.

This data shows that MRI in our unit has a comparable high sensitivity to that in various literature making it a useful tool at ruling out disease with a negative result in the clinical setting. A more useful parameter in the clinical setting is its high precision rate when faced with a positive result. However, its specificity is much lower than that in most published data. A total of 6 tears on MRI turned out not to be on arthroscopy meaning patients could have been subjected to an avoidable invasive procedure in the absence of any other indication. This highlights the importance of obtaining reports from experienced musculoskeletal radiologists and the need for surgeons to review MRI images and match them to clinical information prior to subjecting patients to surgery.

Aim

To review the infants in our district general hospital receiving delayed treatment for DDH i.e. those infants who had more than one ultrasound scan prior to diagnosis and treatment. In this group all scans were abnormal at the time of treatment but the scans at first presentation were normal for age when reviewed by our senior radiologist.

Background

We switched our antibiotic prophylaxis for elective hip and knee surgery from cefuroxime to flucloxacillin with single dose gentamicin in order to reduce the incidence of C. Diff diarrhoea. More patients subsequently appeared to develop acute kidney injury (AKI).

SIGN guidelines advise the use of flucloxacillin and gentamicin instead of cefuroxime as antibiotic prophylaxis for elective hip and knee arthroplasty. It is our impression that this change in practice has been associated with an increased risk of acute kidney injury (AKI).

During a twelve month period we examined the incidence of AKI sequentially in four groups of patients: cefuroxime prophylaxis (n = 46); high dose flucloxacillin (5-8g) with single shot gentamicin (n = 50); low dose flucloxacillin (1-4 g) with single shot gentamicin (n = 45); and finally cefuroxime again (n = 52).

There were no statistically significant differences by chi-square tests for age, gender, operation (hip or knee), ASA, anaesthesia, baseline serum creatinine, hypertension, diabetes or pre-operative medication. The proportion of patients in each antibiotic group with any form of AKI by RIFLE criteria was: cefuroxime group 1 (9%), high dose flucloxacillin (52%), low dose flucloxacillin (22%), cefuroxime 2 (14%) (p < 0.0001 by chi-square test). Odds ratios (OR) for AKI derived from a multivariate logistic regression model and assigning an OR of 1 to cefuroxime group 1 was: high dose flucloxacillin 14.5 (95% CI, 4.2, 50.2); low dose flucloxacillin 3.0 (0.8-10.9) and cefuroxime group 2 1.9 (0.5, 7.4). Three patients in the high dose flucloxacillin group required temporary haemodialysis.

We have shown a strong association between high dose prophylactic flucloxacillin and subsequent development of AKI. We have no reason to believe that this was confounded by any of the co-variates we measured.

We have encountered radiological reports of ‘normal Graf α-angles’ when the femoral head was subluxed. We therefore developed a simple method to determine femoral/acetabular congruency known as the 50/50 method. We compare our method to the established Graf method.

Two identical, randomly assorted sets of 100 ultra-sonograms were evaluated. All ultrasonograms were of patients under 3 months of age within our DDH screening program. The images were assessed to be either ‘normal’ or ‘abnormal’ by 6 FY1’s using each method after reading brief instructions. (Images were classified as normal or abnormal by consensus between an orthopaedic consultant and radiologist who also examined and preformed dynamic screening on each infant).

The mean proportion of abnormal scans with agreement and normal scans with agreement was 0.52 (95% CI 0.39–0.69) and 0.92 (CI 0.87–0.96) respectively, indicating moderate agreement (kappa 0.41, CI 0.12–0.71) for inter-observer variability using the Graf method. On average the inter-observer variability using the 50/50 method for abnormal and normal scans with agreement was 0.60 (CI 0.35–0.84) and 0.92 (95% CI 0.85–0.99) respectively with moderate agreement (kappa 0.50, CI 0.20–0.80). Intra-observer variability between the Graf and 50/50 methods revealed moderate agreement (mean kappa 0.41, CI 0.17–0.66) with the average proportion of abnormal and normal scans with agreement of 0.50 (CI 0.32–0.69) and 0.91 (CI 0.83–0.98) correspondingly. The accuracy of each test was equal, ranging from 84% to 93%.

The 50/50 method is straightforward to both use and teach. Moreover, it successfully serves as “red dot” system to flag up abnormal hips at clinic. The 50/50 method is at least as good as Graf with regard to accuracy, inter-observer and intra-observer variability. We recognise that dynamic screening remains the gold standard.

Introduction: The Pavlik harness is widely used in the management of developmental dysplasia of the hip and its efficacy in the treatment of instability and acetabular dysplasia is well established. There are some hips which although reducible consistently fail to stabilise in a harness irrespective of the age of application. We report three cases in which through altering the method of application of the harness, stability and subsequent normal development was achieved.

Method: Three patients age one week, six weeks and twelve weeks failed to stabilise in a harness applied in the conventional fashion. By rerouting the posterior “abduction strap” in front of the anterior “flexion” strap and attaching it as usual distally we observed improved abduction and more restriction of movement such that the unstable hip was held reduced. Reduction was confirmed by anterior ultrasound. The harness was converted back to the conventional application at four weeks by which time all of the hips had stabilised clinically. It was retained for a further eight weeks.

Results: Significant dysplasia was evident in all three hips at presentation ( alpha angles 32, 48 and 34). At average follow up of 23 months all hips were concentrically reduced with no significant persisting dysplasia nor evidence of avascular necrosis.

Discussion: Early reduction and stabilisation of the femoral head in DDH is important if subsequent intervention is to be minimised and it has been suggested that the more rigid Von Rosen splint is more effective than the Pavlik in achieving this. Our early experience with this simple modification has been successful in treating three unstable hips which would otherwise have failed splintage in our hands. We recommend it as an option to consider in the unstable hip, in conjunction with anterior ultrasound to confirm that reduction has been achieved from the outset.

We have performed a prospective review of 590 consecutive patients treated for a displaced intracapsular femoral neck fracture with a Thompson hemiarthroplasty. 113 patients had the prosthesis cemented, 477 had no cement. The outcome at 12 months was obtained for every patient still alive as regards to pain, mobility, re-operation rate and residential status. There was no significant difference between the 2 groups as regards pain (p = 0.482), decrease in mobility or re-operation rate (p = 0.168). The main determination of poor outcome was increasing age at time of injury and whether the patient was already in institutional care at the time of the injury. The use of cement had no bearing on outcome.

This study is of clinical interest because patients who have undergone uncemented hemiarthroplasty have been shown to have similar out come to cemented hemiarthroplasty in terms of function. In addition possible but preventable complications associated with cementing can be minimized. We now believe there is no primary indication to cement the Thompsons hemiarthroplasty in this group of patients.

There have been smaller studies looking at this, but we believe this to be the largest and most comprehensive to date.