The association of leg length and offset reconstruction after total hip arthroplasty with clinical outcomes.

BACKGROUND: Restoring native hip anatomy and biomechanics is important to create a well-functioning hip arthroplasty. This study investigated the association of hip offset and leg length after hip arthroplasty with clinical outcomes, including patient reported outcome measures, the Trendelenburg Test and gait analysis. METHODS: In 77 patients undergoing primary hip arthroplasty for osteoarthritis (age mean = 65 SD = 11 years; BMI mean = 27 SD = 5 kg/m2), hip offset and leg length discrepancy were measured on anteroposterior radiographs. The Western Ontario & McMaster Universities Osteoarthritis Index, the Trendelenburg Test and gait were assessed preoperatively, and at 3 and 12 months postoperatively. An inertial measurement unit was used to derive biomechanical parameters, including spatiotemporal gait parameters and tilt angles of the pelvis. Relationships between radiographic and functional outcomes were investigated, and subgroups of patients with >15% decreased and increased femoral offset were analysed separately. FINDINGS: Patient-reported function scores and clinical tests demonstrated a few significant, weak correlations with radiographic outcomes (Spearman's ρ range = 0.26-0.32; p < 0.05). Undercorrection of femoral offset was associated with lower patient-reported function scores and with more step irregularity as well as step asymmetry during gait. Postoperative leg length inequality was associated with increased frontal plane tilt angle of the pelvis during the Trendelenburg Test and increased sagittal plane motion of the pelvis during gait. Femoral offset subgroups demonstrated no significant differences for patient-reported function scores and outcomes of the Trendelenburg Test and gait analysis. INTERPRETATION: Reduced hip offset and leg length discrepancy following hip arthroplasty seem to be marginally associated with worse clinical outcomes.

Frontal plane pelvic motion during gait captures hip osteoarthritis related disability.

Gait analysis has widely been accepted as an objective measure of function and clinical outcome. Ambulatory accelerometer-based gait analysis has emerged as a clinically more feasible alternative to optical motion capture systems but does not provide kinematic characterisation to identify disease dependent mechanisms causing walking disability. This study investigated the potential of a single inertial sensor to derive frontal plane motion of the pelvis (i.e. pelvic obliquity) and help identify hip osteoarthritis (OA) related gait alterations. Patients with advanced unilateral hip OA (n = 20) were compared to patients with advanced unilateral knee OA (n = 20) and to a healthy control group (n = 20). Kinematic characterisation of frontal plane pelvic motion during gait demonstrated decreased range of motion and increased asymmetry for hip OA patients specifically.

The impact of leg length discrepancy on patient satisfaction and functional outcome following total hip arthroplasty.

A series of 191 patients undergoing THA with a standardised stem were studied. The effect of leg length discrepancy (LLD) on patient function (Oxford Hip Score), health measures (Short Form 12) and satisfaction (Self-Administered Patient Satisfaction Scale) at a mean 3.8 years of follow up (range 3.3 to 4.9) is reported. 8.9% of cases had shortening, 0.5% no LLD and 90.6% had lengthening. In 21.5% the LLD was more than 10mm, in 37.1% 5-10mm, and in 40.9% 0-5mm. There was no significant difference in patient reported outcome measures (PROMs) according to LLD. Correlation of recorded measurements between multiple observers was excellent (0.93). LLD following total hip arthroplasty remains common but in this series, was not correlated with PROMs.

Direct thrombin inhibitor (DTI) vs. aspirin in primary total hip and knee replacement using wound ooze as the primary outcome measure. A prospective cohort study.

The latest NICE guidance dictates that all patients undergoing lower-limb arthroplasty should be prescribed potent venous thromboembolic (VTE) prophylaxis. However, use of potent anti-thrombotics is likely to lead to increased post-operative wound ooze. Postoperative wound ooze is associated with increased risk of infection. This study used a prospective, consecutive, multi-surgeon sample of 110 patients undergoing primary total hip replacement (THR) and total knee replacement (TKR) prescribed either direct thrombin inhibitor (DTI) (n=51, 26 males: 25 females, age 69 ±18) or aspirin (n=59, 25 males: 34 females, age 69 ± 19). Hospital stay, body mass index (BMI), wound length and patient demographics were documented along with a daily assessment of wound ooze. The use of DTI's was associated with a significant increase in mean days to dryness in both THR (6.2 ± 0.98, 95% C.I. 5.2-7.1) and TKR (6.6 ± 1.89, 95% C.I. 4.7-8.5) compared to aspirin in THR (3.0 ± 1.03, 95% C.I 1.9-4.0) and TKR (3.4 ± 1.21, 95% C.I 2.2-4.6) with p-values of <0.0001 and 0.0024 for THR and TKR respectively. Age, gender and wound length were not found to be significant confounding variables. DTI's proven benefit in lowering venous thromboembolism when compared with aspirin needs to be balanced with their increased cost and increased duration of wound ooze.

Acute knee dislocation: an evidence based approach to the management of the multiligament injured knee.

Traumatic knee dislocations are uncommon yet serious injuries that historically have had variable prognosis. The evaluation and management of traumatic knee dislocations remains controversial. Appropriate early management has been shown to have a significant impact on long term functional outcome. A comprehensive review of the recent literature is presented alongside our current approach to management. The dislocated knee is an under diagnosed injury which relies on a high index of clinical suspicion on presentation of any knee injury. There is now a degree of consensus regarding need for surgery, timing of surgery, vascular investigations, surgical techniques and rehabilitation protocols. Vigilant monitoring for neurovascular complications, appropriate investigations and early involvement of surgeons with a specialist interest in knee ligament surgeries is the key to successful management of these difficult injuries.

Anti-embolism stockings and proximal indentation.

The authors of this study noticed that the elastic garters of below knee anti-embolism stockings (AES) were indenting the proximal calves of patients after application and feared this might be interrupting venous return. This was lower on one ward which had a rigorous standardized protocol for sizing and checking stockings. Hypotheses were that proximal indentation caused higher proximal than distal pressures (reverse gradients) and that by adopting the standardized protocol throughout the unit, proximal indentation could be reduced. Fifty-seven patients were recruited after total hip replacement (THR) or total knee replacement (TKR) in a regional orthopaedic centre. The authors implemented the standardized protocol for sizing stockings and measured the pressures under them. After implementation of the standardized protocol, proximal indentation fell from 53% to 19% (p<0.05), incorrectly sized stockings from 74% to 34% (p<0.05) and removal of stockings by patients from 32% to 0% (p<0.05). In total, 21% of patients had reverse gradients which occurred in 41% of legs with proximal indentation and 8% without. When reverse gradients or proximal indentation exist, AES may not be as effective and may be counterproductive. A standardized protocol of nursing practice is critical to optimizing AES after THR and TKR. More in-vivo research is needed on AES after hip and knee replacement.