Lateral femoral cutaneous nerve block with different volumes of Ropivacaine:A randomized trial in healthy volunteers

BACKGROUND: Nerve block of the lateral femoral cutaneous nerve (LFCN) is a predominantly sensory block. It reduces pain following total hip arthroplasty (THA), but the non-responder rate is high. We hypothesized, that an increased volume of ropivacaine, would result in greater coverage of incisions used for THA.METHODS: We conducted a randomized, blinded trial in 20 healthy volunteers. Participants were randomized to receive bilateral LFCN-blocks with 8 mL ropivacaine 0.75% on the left side and 16 mL ropivacaine 0.75% on the right side, or vice versa. Allocation was blinded to both participants and outcome assessors. Before nerve block performance, incision lines for posterior and lateral THA approaches were depicted with invisible ultraviolet-paint, thereby securing sufficient blinding during outcome assessment. The blocked area was mapped using temperature and mechanical discrimination tests. Quadriceps muscle strength was monitored. Primary outcome was coverage of the posterior incision line assessed by temperature discrimination test.RESULTS: We found no difference in coverage of the posterior or lateral incision lines when comparing LFCN-blocks with 8 mL versus 16 mL of ropivacaine. The blocked area was significantly larger in the 16 mL group, assessed by both temperature discrimination test (p = 0.012) and mechanical discrimination test (p = 0.034). We observed no difference between groups regarding quadriceps muscle strength (p = 1.0).CONCLUSIONS: A LFCN-block with increased volume of ropivacaine from 8 mL to 16 mL did not result in a greater coverage of posterior or lateral incision lines used for THA, but in a larger blocked sensory area.TRIAL REGISTRATION: Clinicaltrials.gov: NCT03138668 . Registered 3rd of May 2017.</p

Radiographic cup position following posterior and lateral approach to total hip arthroplasty. An explorative randomized controlled trial.

The two most common surgical approaches to total hip arthroplasty are the posterior approach and lateral approach. The surgical approach may influence cup positioning and restoration of the offset, which may affect the biomechanical properties of the hip joint. The primary aim was to compare cup position between posterior approach and lateral approach. Secondary aims were to compare femoral offset, abductor moment arm and leg length discrepancy between the two approaches. Eighty patients with primary hip osteoarthritis were included in a randomized controlled trial and assigned to total hip arthroplasty using posterior approach or lateral approach. Postoperative radiographs from 38 patients in each group were included in this study for measurement of cup anteversion and inclination. Femoral offset, cup offset, total offset, abductor moment arm and leg length discrepancy were measured on preoperative and postoperative radiographs in 28 patients in each group. We found that mean anteversion was 5° larger in the posterior approach group (95% CI, -8.1 to -1.4; p = 0.006), while mean inclination was 5° less steep (95% CI, 2.7 to 7.2; p<0.001) compared with the lateral approach group. The posterior approach group had a larger mean femoral offset of 4.3mm (95% CI, -7.4 to -1.3, p = 0.006), mean total offset of 6.3mm (95% CI, -9.6 to -3; p<0.001) and mean abductor moment arm of 4.8mm (95% CI, -7.6 to -1.9; p = 0.001) compared with the lateral approach group. We found a larger cup anteversion but less steep cup inclination in the posterior approach group compared with the lateral approach group. Femoral offset and abductor moment arm were restored after total hip arthroplasty using lateral approach but significantly increased when using posterior approach

Patient-reported outcome after total hip arthroplasty: comparison between lateral and posterior approach: A randomized controlled trial in 80 patients with 12-month follow-up

Background and purpose — Criticism of the lateral approach (LA) for hip arthroplasty is mainly based on the risk of poor patient-reported outcomes compared to the posterior approach (PA). However, there have been no controlled studies comparing patient-reported outcomes between them. In this randomized controlled trial, we tested the hypothesis that patient-reported outcomes are better in patients who have undergone total hip arthroplasty (THA) with PA than in those who have undergone THA with LA, 12 months postoperatively. Patients and methods — 80 patients with hip osteoarthritis (mean age 61 years) were randomized to THA using PA or the modified direct LA. We recorded outcome measures preoperatively and 3, 6, and 12 months postoperatively using the Hip Disability and Osteoarthritis Outcome Score–Physical Function Short Form (HOOS-PS) as the primary outcome. Secondary outcomes were HOOS-Pain, HOOS-Quality-Of-Life, EQ-5D, UCLA Activity Score, and limping. Results — We found no statistically significant difference in the improvements in HOOS-PS between the treatment groups at 12-month follow-up. All secondary outcomes showed similar results except for limping, where PA patients improved significantly more than LA patients. Interpretation — Contrary to our hypothesis, patients treated with PA did not improve more than patients treated with LA regarding physical function, pain, physical activity, and quality of life 12 months postoperatively. However, limping was more pronounced in the LA patients

The effect of posterior and lateral approach on patient-reported outcome measures and physical function in patients with osteoarthritis, undergoing total hip replacement:a randomised controlled trial protocol

BACKGROUND: Total hip replacement provides pain relief and improves physical function and quality of life in patients with end-stage hip osteoarthritis. The incidence of hip replacement operations is expected to increase due to the growing elderly population. Overall, the posterior approach and lateral approach are the two most commonly used approaches for hip replacement operations. The posterior approach is associated with an increased risk of revision due to dislocations, and some studies have shown that the lateral approach is associated with reduced patient-reported outcomes, including physical function and pain; however, this has not been investigated in a randomised controlled trial with a twelve-month follow-up. We hypothesized that the lateral approach has an inferior outcome in patient-reported outcome compared with the posterior approach after one year. METHODS/DESIGN: The trial is a prospective, double blinded, parallel-group controlled trial with balanced randomisation [1: 1]. Patients with hip osteoarthritis scheduled for hip replacement surgery, aged 45–70 years, will be consecutively recruited and randomised into two groups. Group A will receive hip replacement using the posterior approach, and Group B will receive hip replacement using the lateral approach. The primary end-point for assessing the outcome of the two interventions will be twelve months after surgery. Follow-up will also be performed after three and six months. The primary outcome is Hip Disability and Osteoarthritis Outcome Score, subscale of "Physical function Short form" (HOOS-PS) Secondary outcome measures include two other subscales of HOOS ("Pain" and "Hip related Quality of Life"), physical activity level (UCLA activity score), limping (HHS) and general health status (EQ-5D-3L). Explorative outcomes include physical function test, 3D-gait-analysis and muscle strength. DISCUSSION: To our knowledge, this is the first randomised controlled trial comparing the posterior approach with the lateral approach with patient reported outcome as the primary outcome and with a twelve-month follow-up. TRIAL REGISTRATION: Clinicaltrial.gov:NCT01616667. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2474-15-354) contains supplementary material, which is available to authorized users

The efficacy of modified direct lateral versus posterior approach on gait function and hip muscle strength after primary total hip arthroplasty at 12months follow-up. An explorative randomised controlled trial

BACKGROUND: The lateral and the posterior approach are the most commonly used procedures for total hip arthroplasty. Due to the detachment of the hip abductors, lateral approach is claimed to cause reduced hip muscle strength and altered gait pattern. However, this has not been investigated in a randomised controlled trial. The aim was to compare the efficacy of total hip arthroplasty performed by lateral or posterior approach on gait function and hip muscle strength up to 12months post-operatively. We hypothesised that posterior approach would be superior to lateral approach.METHODS: Forty-seven patients with primary hip osteoarthritis were randomised to total hip arthroplasty with either posterior or lateral approach and evaluated pre-operatively, 3 and 12months post-operatively using 3-dimensional gait analyses as objective measures of gait function, including Gait Deviation Index, temporo-spatial parameters and range of motion. Isometric maximal hip muscle strength in abduction, flexion and extension was also tested.FINDINGS: Post-operatively, no between-group difference in gait function was observed. However, both hip abductor and flexor muscle strength improved more in the posterior approach group: -0.20(Nm/kg)[95%CI:-0.4 to 0.0] and -0.20(Nm/kg)[95%CI:-0.4 to 0.0], respectively.INTERPRETATION: Contrary to our first hypothesis, the overall gait function in the posterior approach group did not improve more than in the lateral approach group. However, in agreement with our second hypothesis, patients in the posterior approach group improved more in hip abductor and flexor muscle strength at 12months. Further investigation of the effect of reduced maximal hip muscle strength on functional capacity is needed. ClinicalTrials.gov. No.: NCT01616667.</p

Radiographic cup position following posterior and lateral approach to total hip arthroplasty. An explorative randomized controlled trial

<div><p>The two most common surgical approaches to total hip arthroplasty are the posterior approach and lateral approach. The surgical approach may influence cup positioning and restoration of the offset, which may affect the biomechanical properties of the hip joint.</p><p>The primary aim was to compare cup position between posterior approach and lateral approach. Secondary aims were to compare femoral offset, abductor moment arm and leg length discrepancy between the two approaches. Eighty patients with primary hip osteoarthritis were included in a randomized controlled trial and assigned to total hip arthroplasty using posterior approach or lateral approach. Postoperative radiographs from 38 patients in each group were included in this study for measurement of cup anteversion and inclination. Femoral offset, cup offset, total offset, abductor moment arm and leg length discrepancy were measured on preoperative and postoperative radiographs in 28 patients in each group. We found that mean anteversion was 5° larger in the posterior approach group (95% CI, -8.1 to -1.4; p = 0.006), while mean inclination was 5° less steep (95% CI, 2.7 to 7.2; p<0.001) compared with the lateral approach group. The posterior approach group had a larger mean femoral offset of 4.3mm (95% CI, -7.4 to -1.3, p = 0.006), mean total offset of 6.3mm (95% CI, -9.6 to -3; p<0.001) and mean abductor moment arm of 4.8mm (95% CI, -7.6 to -1.9; p = 0.001) compared with the lateral approach group. We found a larger cup anteversion but less steep cup inclination in the posterior approach group compared with the lateral approach group. Femoral offset and abductor moment arm were restored after total hip arthroplasty using lateral approach but significantly increased when using posterior approach.</p></div