Joint aspiration is a useful tool during preoperative workup in suspected periprosthetic infection. The aim of this study was to review efficacy of joint aspiration in our unit and compare results with the published literature. We undertook a retrospective review of 153 consecutive patients who underwent joint aspirations for suspected periprosthetic infection between 03/2011 and 10/2012 who were identified from the hospital electronic database. As per protocol, joint fluid was sent in an EDTA tube for cell count, Paediatric blood culture bottle and the remainder in a specimen pot. 105 (69%) were TKRs and 48 (31%) were THRs. Intraoperative samples were sent as per protocol in only 40 (26%) cases. The hit rate of positive cultures was 11/153 (7%) and specimens sent in paediatric culture bottles identified more positives than if it was omitted (10.5 Vs 5.5%). In conclusion, the hit rate of positive cultures is low in this study compared to the literature (7% Vs 33%) and this is likely due to blanket aspiration of all patients who are undergoing revision. In addition, specimens sent in paediatric culture bottles seem to identify more positives. We recommend cases are selected for aspiration according to AAOS guidelines.
Medical and Health care products Regulatory Agency (MHRA) released an alert in 2010 regarding metal on metal (MoM) bearings in hip arthroplasty owing to soft tissue reactions to Metal debris. Following this, we adopted a targeted screening protocol to review patients with this bearing couple. 218 Patients (252 hips), mean age 53.2 (25–71) years were assessed clinically using Oxford hip score (OHS) and X-ray examination. The mean follow up was 44.5 (12–71) months. Patients were considered at higher risk (118 patients/133 hips) if they had deterioration of OHS (50 hips), Small sized heads <50mm (114 hips), acetabular inclination >500 (37 hips), neck thinning (17 hips). These patients (107/118), (120/133 hips) were further investigated through measuring metal ion levels and magnetic resonance imaging (MRI). The mean blood levels of cobalt and chromium in this group were 6.7, 8.62 ug/L respectively. Metal ions increased significantly with high acetabular inclination angles (p=0.01, 0.004 respectively), but was not affected by the size of the head (p=0.13). MRI showed periprosthetic lesions around 28 hips (26 fluid collections, 2 pseudotumours). The screening protocol detected all patients who subsequently required elective revision. We believe that this protocol was beneficial in detecting problematic MoM hip replacements.
Scarf osteotomy for correction of painful hallux valgus is an effective technique, giving a predictable correction of the deformity. However, some patients remain less than fully satisfied, despite normalisation of the usual radiographic parameters. This study examines whether lateral soft tissue release can cause late splaying of the forefoot. A series of 32 feet in 29 consecutive patients in a single centre, operated on by a single surgeon, over a 12 month period were studied. After pre-operative weight-bearing x-rays and consenting, a standardised ‘Barouk-technique’ Scarf procedure was undertaken with on-table assessment for lateral soft tissue release and phalangeal varisation. Post-operatively, patients were kept heel weight-bearing without cast for 6 weeks, with use of a fabric splint after removal of bandages at 2 weeks. HVA and IMA were measured pre-operatively, at 6 weeks, and at 6-12 month follow-up. Distance from the mid-points of the 1st to the 5th metatarsal heads and distance from lateral sesamoid to 2nd metatarsal shaft were also recorded by blinded observers. AOFAS Foot Scores were collected prospectively. Student's t-test for single-tailed paired data was applied and p-values calculated. There were 22 female and 10 male feet; in patients aged 27 to 74 (mean 58). Average HVA improved from 34° to 17° and was maintained at 16°. IMA improved from 14° to 7°, but then increased significantly to 10°. Overall inter-metatarsal width reduced from 76mm to 65mm but then significantly increased to 71mm. Sesamoid distance was also reduced and later increased, but not significantly. Mean foot scores improved from 52 to 85 at late follow-up. Complication rate was low. Late widening occurred more in those feet with bigger original HVA, which were likely to have had more extensive soft tissue release (deep inter-metatarsal ligament). We recommend cautious release; and pre-operatively counselling specifically regarding eventual overall foot-width.
