Dennis Molloy

Comparison of topical fibrin spray and tranexamic acid on blood loss after total knee replacement: A PROSPECTIVE, RANDOMISED CONTROLLED TRIAL

We performed a randomised, controlled trial involving 150 patients with a pre-operative level of haemoglobin of 13.0 g/dl or less, to compare the effect of either topical fibrin spray or intravenous tranexamic acid on blood loss after total knee replacement. A total of 50 patients in the topical fibrin spray group had 10 ml of the reconstituted product applied intra-operatively to the operation site. The 50 patients in the tranexamic acid group received 500 mg of tranexamic acid intravenously five minutes before deflation of the tourniquet and a repeat dose three hours later, and a control group of 50 patients received no pharmacological intervention. There was a significant reduction in the total calculated blood loss for those in the topical fibrin spray group (p = 0.016) and tranexamic acid group (p = 0.041) compared with the control group, with mean losses of 1190 ml (708 to 2067), 1225 ml (580 to 2027), and 1415 ml (801 to 2319), respectively. The reduction in blood loss in the topical fibrin spray group was not significantly different from that achieved in the tranexamic acid group (p = 0.72).

The transverse acetabular ligament: an aid to orientation of the acetabular component during primary total hip replacement: A PRELIMINARY STUDY OF 1000 CASES INVESTIGATING POSTOPERATIVE STABILITY

Ensuring the accuracy of the intra-operative orientation of the acetabular component during a total hip replacement can be difficult. In this paper we introduce a reproducible technique using the transverse acetabular ligament to determine the anteversion of the acetabular component. We have found that this ligament can be identified in virtually every hip undergoing primary surgery. We describe an intra-operative grading system for the appearance of the ligament. This technique has been used in 1000 consecutive cases. During a minimum follow-up of eight months the dislocation rate was 0.6%. This confirms our hypothesis that the transverse acetabular ligament can be used to determine the position of the acetabular component. The method has been used in both conventional and minimally-invasive approaches.

The use of ceramic-on-ceramic bearings in isolated revision of the acetabular component

The practice of removing a well-fixed cementless femoral component is associated with high morbidity. Ceramic bearing couples are low wearing and their use minimises the risk of subsequent further revision due to the production of wear debris. A total of 165 revision hip replacements were performed, in which a polyethylene-lined acetabular component was revised to a new acetabular component with a ceramic liner, while retaining the well-fixed femoral component. A titanium sleeve was placed over the used femoral trunnion, to which a ceramic head was added. There were 100 alumina and 65 Delta bearing couples inserted. The mean Harris hip score improved significantly from 71.3 (9.0 to 100.0) pre-operatively to 91.0 (41.0 to 100.0) at a mean follow up of 4.8 years (2.1 to 12.5) (p < 0.001). No patients reported squeaking of the hip. There were two fractures of the ceramic head, both in alumina bearings. No liners were seen to fracture. No fractures were observed in components made of Delta ceramic. At 8.3 years post-operatively the survival with any cause of failure as the endpoint was 96.6% (95% confidence interval (CI) 85.7 to 99.3) for the acetabular component and 94.0% (95% CI 82.1 to 98.4) for the femoral component. The technique of revising the acetabular component in the presence of a well-fixed femoral component with a ceramic head placed on a titanium sleeve over the used trunnion is a useful adjunct in revision hip practice. The use of Delta ceramic is recommended.

Placement of the acetabular component

Ideal placement of the acetabular component remains elusive both in terms of defining and achieving a target. Our aim is to help restore original anatomy by using the transverse acetabular ligament (TAL) to control the height, depth and version of the component. In the normal hip the TAL and labrum extend beyond the equator of the femoral head and therefore, if the definitive acetabular component is positioned such that it is cradled by and just deep to the plane of the TAL and labrum and is no more than 4mm larger than the original femoral head, the centre of the hip should be restored. If the face of the component is positioned parallel to the TAL and psoas groove the patient specific version should be restored. We still use the TAL for controlling version in the dysplastic hip because we believe that the TAL and labrum compensate for any underlying bony abnormality. The TAL should not be used as an aid to inclination. Worldwide, > 75% of surgeons operate with the patient in the lateral decubitus position and we have shown that errors in post-operative radiographic inclination (RI) of > 50° are generally caused by errors in patient positioning. Consequently, great care needs to be taken when positioning the patient. We also recommend 35° of apparent operative inclination (AOI) during surgery, as opposed to the traditional 45°.

Limb length restoration during total hip arthroplasty: Use of a caliper to control femoral component insertion and accurate acetabular placement relative to the transverse acetabular ligament

Current methods for restoring or preserving limb length following total hip arthroplasty largely depend on restoring the distance between a fixed point on the pelvis and femur. Each of these techniques allows length correction to be made by combining the effects of both acetabular and femoral height into a single measurement. These methods help to minimise inequality but are anatomically flawed, as they do not allow independent control of placement of the femoral and acetabular components which both contribute to leg length. To address this we present and evaluate a technique that uses a caliper to control the vertical placement of the femoral component and the transverse acetabular ligament to control the vertical height of the acetabular component. Limb lengths were measured in 200 patients who had undergone primary total hip arthroplasty using this technique. Using this method 94% had a postoperative limb length inequality that was 6mm or less (average, +0.38 mm). The maximum measured limb length inequality was +/-8 mm.

Sub-ungual epidermoid cyst.

A 53 year-old female was referred urgently to a regional plastic surgery unit with a 2-week history of increasing pain and swelling of the tip of the middle finger of her non-dominant hand. She gave no history of trauma to the digit. Examination revealed a painful subungal lesion. On X-ray, it was seen to be pressing on bone, but not of bony origin (Fig 1). She had immediately previously been prescribed a 5 day course of antibiotics which had no effect. Exploration of the lesion was carried out under general anaesthesia and identified a subungual, encapsulated lesion containing a material consistent with keratin. Histological examination confirmed the lesion to be an epidermoid cyst. Postoperatively, on further questioning, the patient recalled that she had crushed her finger 12 years previously, causing loss of the nail. Epidermoid cysts occuring below the nail bed are not frequently reported (Saez-de-Ocariz et al., 2001). Differential diagnoses include foreign body granulomas and glomus tumours, the latter usually being slow growing (Tomak et al., 2003).

Correction of pelvic adduction during total hip arthroplasty reduces variability in radiographic inclination: findings of a randomised controlled trial

Introduction: The study aims were to identify the incidence of pelvic adduction during total hip arthroplasty (THA) in lateral decubitus and to determine, when aiming for 35° of apparent operative inclination (AOI), which of 3 operating table positions most accurately obtained a target radiographic inclination (RI) of 42°: (1) horizontal; (2) 7° head-down; (3) patient-specific position based on correction of pelvic adduction. Methods: With patients seated on a levelled theatre table, a ruler incorporating a spirit level was used to draw transverse pelvic lines (TPLs) on the skin overlying the pelvis and sacrum. Subsequently, when positioned in lateral decubitus these lines provided a measure of pelvic adduction. 270 participants were recruited, with 90 randomised to each group for operating table position. In all cases target AOI was 35°, aiming to achieve a target RI of 42°. The primary outcome measure was absolute (unsigned) deviation from the target RI of 42°. Results: 266/270 patients demonstrated pelvic adduction (overall mean 4.4°, range 0– 9.2°). No patients demonstrated pelvic abduction. There were significant differences in RI between each of the 3 groups. The horizontal table group displayed the highest mean RI. The patient specific table position group achieved the smallest absolute deviation from target RI of 42°. Discussion: In lateral decubitus, unrecognised pelvic adduction is common and is an important contributor to unexpectedly high RI. The use of preoperative TPLs helps identify pelvic adduction and its subsequent correction reduces variability in RI. Clinical Trial Protocol number: NCT01831401.

Reducing variability in apparent operative inclination during total hip arthroplasty: findings of a randomised controlled trial

Aims: To determine which of 3 methods of cup insertion most accurately achieved a target apparent operative inclination (AOI) of 35° ± 2.5°: (1) Freehand; (2) Modified Mechanical Alignment Guide (MAG); or (3) Digital Inclinometer assisted. Methods: Using a cementless cup via a posterior approach in lateral decubitus 270 participants were recruited, with 90 randomised to each method. The primary outcome was the unsigned deviation from target AOI. The digital inclinometer was used to measure AOI in all cases, though the surgeon remained blinded to the reading intraoperatively for both the Freehand and MAG methods. Results: Mean deviation from target AOI for the Freehand, Modified 35° MAG and Digital Inclinometer techniques was 2.9°, 1.8° and 1.3° respectively. When comparing mean deviation from target AOI, statistically significant differences between the Freehand / Inclinometer groups (p < 0.001), the Freehand / Modified 35° MAG groups (p < 0.001) and the Digital Inclinometer / Modified 35° MAG groups (p < 0.023) were evident. The Digital Inclinometer technique enabled the surgeon to achieve a target AOI of 35° ± 2.5° in 88% of cases, compared to 71% of Modified 35° MAG cases and only 51% of Freehand cases. Discussion: The Digital Inclinometer and the Modified 35° MAG techniques were both more accurate than the Freehand technique, with the Digital Inclinometer technique proving most accurate overall. Radiographic inclination (RI) is also influenced by operative anteversion; however, the greatest source of error with respect to RI occurs when the pelvic sagittal plane is not horizontal at the time of acetabular component insertion. Clinical Trial Protocol number: NCT01831401