Routine postoperative blood tests in all patients undergoing Total Hip Arthroplasty as part of an enhanced recovery pathway: Are they necessary?

INTRODUCTION: The increasing demand for Total Hip replacement (THR)/Total Hip Arthroplasty (THA) continues to place significant financial pressure on the National Health Service (NHS). Many institutions undertake post-operative blood tests routinely in this group of patients. The aim of this study was to identify if such routine blood tests (Full Blood Count (FBC) and Urea and Electrolytes(U&Es)) are required in all THR patients post-operatively. METHODS: Single institute, Multi-surgeon, retrospective observational study of consecutive patients who underwent primary elective THR done from Jan 2014 to Dec 2018.Post-operative blood tests and medical records were reviewed to identify derangement in haemoglobin (Hb) level and renal function requiring clinical intervention. RESULTS: Over the period of 4 years, 353 patients underwent elective THR with mean age of 70 years (range: 42-90). There were 203 Males and 150 Females. Mean pre-operative Hb was 134.7 g/l. Mean post-operative drop in Hb was 22.3 g/l. None of the patients in ASA grade 1 and 2 with age ≤70 years required blood transfusion post operatively.6.4% of patients (n = 18/280) with an ASA of 1-2 had postoperative blood results requiring intervention of which only four (1.2%) were ≤70 years of age compared to 17.8% of patients (n = 14/73) with ASA 3-4.Overall none of the patients in ASA grade 1 and 2 with age ≤70 years required blood transfusion post operatively nor had electrolyte disturbance. 1.2% had deranged renal function that needed minor clinical intervention. CONCLUSION: Routine post-operative blood analyses may not required for all patients undergoing THA. Young and healthier patients seldom have significant abnormalities on routine post-operative blood analyses which requires clinical intervention.

The Interchangeability of Plasma and Whole Blood Metal Ion Measurement in the Monitoring of Metal on Metal Hips.

One hundred and twenty six paired samples of plasma and whole blood were measured with inductively coupled plasma mass spectrometry technique for metal ions analysis to determine a relationship between them. There was a significant difference between the mean plasma and whole blood concentrations of both cobalt (Co) and chromium (Cr) (p < 0.0001 for both Co and Cr). The mean ratio between plasma and whole blood Cr and Co was 1.56 (range: 0.39-3.85) and 1.54 (range: 0.64-18.26), respectively, but Bland and Altman analysis illustrated that this relationship was not universal throughout the range of concentrations. There was higher variability at high concentrations for both ions. We conclude that both these concentrations should not be used interchangeably and conversion factors are unreliable due to concentration dependent variability.

Cemented metal-on-metal total hip replacement with 28-mm head: prospective, long-term, clinical, radiological and metal ions data.

PURPOSE: The aim of this study was to evaluate the long-term clinical, radiological and metal ion blood concentration results following 28-mm metal-on-metal cemented total hip replacement using Metasul(®) acetabular component and polished, cannulated Allopro CF-30 (Sulzer-Medica, subsequently Centerpulse-Zimmer, Winterthur, Switzerland) femoral component. METHODS: Prospective follow-up of patients operated between 1997 and 2000 at a district general hospital. RESULTS: Seventy-nine patients (89 implants) with female predominance and median age of 66 years (IQR 45-87 years) were prospectively followed up for mean 13 years (11-14 years). There was significant improvement in Harris hip score (paired Student's t test p = 0.0001). The mean plasma cobalt and chromium levels were 1.3 µg/L (IQR 0.5-23.9) and 3.6 µg/L (IQR 1.0-22), respectively. Elevated plasma metal ions >7 µg/L were noted in four asymptomatic patients with negative ultrasound examination. Radiolucent lines were present in various zones but majority were stable. One femoral component was revised due to aseptic femoral loosening. Three acetabular and one femoral component have radiologically failed but not revised yet. The Kaplan-Meier survival at 14 years was 92 % for failure as endpoint. CONCLUSION: The long-term survival of Metasul(®) cemented total hip replacements using 28-mm metal-on-metal head is comparable with metal on polyethylene bearing devices.

The Correlation of Serum Metal Ions with Functional Outcome Scores at Three-to-Six Years following Large Head Metal-on-Metal Hip Arthroplasty.

Based on success of hip resurfacing, large head Metal on Metal (MoM) hip arthroplasty has gained significant popularity in recent years. There are growing concerns about metal ions related soft tissue abnormalities. The aim of this study was to define a correlation of metal ions with various functional outcome scores following large head MoM hip arthroplasty. Consecutive cohort of 70 patients (76 hips) with large head MoM hip arthroplasty using SL-Plus femoral stem and Cormet acetabular component were prospectively followed up. An independent observer assessed the patients which included serology for metal ion levels and collection of Oxford Hip, Harris hip, WOMAC, SF-36 & modified UCLA scores. Median serum cobalt and chromium levels were 3.10 µg/L (0.35-62.92) and 4.21 µg/L (0.73-69.27) with total of median 7.30 µg/L (2.38-132.19). The median Oxford, Harris, WOMAC, SF-36 and modified UCLA scores were 36 (6-48), 87 (21-100), 36 (24-110), 104 (10-125), and 3 (1-9), respectively. Seventeen patients had elevated serum cobalt and chromium levels ≥7 µg/L. There was no significant correlation between serum metal ion levels with any of these outcome scores. We recommend extreme caution during follow up of these patients with large head MoM arthroplasty.

Socio-economic impact of Birmingham hip resurfacing on patient employment after ten years.

Birmingham hip resurfacing is an attractive option for treatment of arthritis in young and active patients. The aim of this study was to assess the socio-economic impact of Birmingham hip resurfacing on their employment and work intensity at ten years. A cohort of 90 consecutive patients with 100 Birmingham hip resurfacing, performed by single surgeon, were reviewed prospectively. The mean age was 51 years at surgery. Prospective review was undertaken from surgery until the tenth post-operative year. Overall, 90% of patients were in the same employment following surgery. Two patients who were employed before surgery were unemployed. Three patients had to decrease their work intensity but were still employed. Three out of five disabled patients regained employment following surgery. Seventy-eight patients were able to continue their employment with no or minimal restriction. Birmingham hip resurfacing allows the majority of patients to continue their same employment at similar intensity ten years following surgery.

Use of elastic stable intramedullary nailing for treating unstable forearm fractures in children.

BACKGROUND: The majority of the pediatric diaphyseal forearm fractures are treated with closed reduction and the application of an above elbow cast for a varying period, depending on the age of the child. Some forearm diaphyseal fractures require osteosynthesis mainly because of the presence of an unacceptable angular deformity, fracture instability, presence of an open injury or failure of conservative management in the form of redisplacement in the cast after manipulation. METHODS: We present our experience with elastic stable intramedullary nailing (ESIN) for displaced and unstable pediatric diaphyseal fractures. A consecutive series of 21 patients treated with ESIN between 1997 and 2005 have been reviewed retrospectively. There were 14 boys and 7 girls with a median age of 11.8 years. All fixations were protected in an above elbow plaster cast. Patients were followed up for an average of 12.8 months (Range, 12-21.5 months). RESULTS: Clinical and radiologic union was achieved within 13 weeks after the procedure in 19 children. One patient had delayed union of the ulna which finally united at 9 months after operation without any further intervention. Another patient had nonunion of ulna that required autologous bone marrow injection after 1 year before full consolidation occurred. Complications were all modest and transient and eventually all patients achieved a good functional clinical outcome. CONCLUSION: We think that the technique has many merits over a more traditional plating technique including a minimally invasive technique, a less time consuming procedure and easier metal work removal. We think that cosmesis is perhaps the most important to our patients because the wounds are small and less conspicuous than the traditional Henry approach for plating which leaves a long unsightly volar forearm scar. We think that ESIN is an attractive treatment option for displaced and unstable diaphyseal forearm fractures in children.