Lateral Total Hip Arthroplasty Research Articles

Accuracy of Cup Placement Angle, Leg Lengthening, and Offset Measurement Using an AR-Based Portable Navigation System: Validation in Supine and Lateral Decubitus Positions for Total Hip Arthroplasty

Background and Objectives: Total hip arthroplasty (THA) requires accurate implant placement to ensure optimal outcomes. In this study, the AR Hip navigation system, an imageless portable navigation tool using augmented reality (AR), was evaluated for measuring radiographic inclination (RI), anteversion (RA), leg lengthening (LL), and offset (OS) changes in supine and lateral decubitus THA. Notably, this is the first report to assess the accuracy of LL and OS measurements using AR technology. Methods: We analyzed 48 hips from primary THA patients: 17 in the supine (S) group and 31 in the lateral (L) group. RI, RA, LL, and OS were measured intraoperatively using AR Hip and postoperatively using Zed Hip 3D software (Version 18.0.0.0). The absolute errors and outlier rates (≥5° for RI/RA and ≥5 mm for LL/OS) were compared between groups. Results: The mean intraoperative RI values with AR Hip were 40.1 ± 0.6° (S), 40.2 ± 1.2° (L), and 40.1 ± 1.0° (total), while the postoperative RI values with Zed Hip were 39.7 ± 2.9° (S), 39.5 ± 2.5° (L), and 39.6 ± 2.6° (total). The absolute errors were 1.8 ± 1.7° (total), with no significant group differences (p = 0.957). For RA, the errors were 2.0 ± 1.2° (total) (p = 0.771). The LL errors were 2.3 ± 2.2 mm (total) (p = 0.271), and the OS errors were 3.5 ± 2.8 mm (total) (p = 0.620). The outlier rates for RI were 11.8% (S) and 3.2% (L); for RA, 0% (S) and 3.2% (L); for LL, 29.4% (S) and 6.5% (L) with a significant difference (p = 0.031); and for OS, 23.5% (S) and 25.8% (L). No significant differences were observed for RI, RA, or OS. Conclusions: AR Hip provided accurate measurements of cup orientation, LL, and OS in both supine and lateral THA. Importantly, this study is the first to report the accuracy of LL and OS measurements using AR technology, demonstrating the potential of AR Hip for improving THA precision.

The Influence of Lateral and Posterior Total Hip Arthroplasty Approaches on Muscle Activation and Joint Mechanics During Gait

BackgroundLateral and posterior total hip arthroplasty (THA) approaches disrupt muscle function, which could impact gait. The objectives of this study were to compare muscle activation and joint mechanics during gait, and isometric strength between participants after lateral and posterior THA approaches and healthy adults. MethodsParticipants 1 year post-THA from either lateral (n = 21) or posterior (n = 21) approaches, and healthy adults (n = 21) ambulated at self-selected speeds. Surface electromyography, optical motion capture, and force plates measured muscle activation and joint mechanics during gait. A dynamometer measured isometric torque. Gait characteristics and isometric torque were compared using analysis of variance and effect sizes (d). ResultsLateral THA group had higher gluteus medius amplitudes during gait compared to the healthy group (P < .01, d = −0.97). Posterior THA group had higher gluteus maximus amplitudes during loading response (P = .02, d = −0.94) and higher hamstring amplitudes during midstance (P = .02, d = 0.45-1.31) than the healthy group. Both THA groups had decreased hip flexion and adduction angle excursions during gait (d = 0.89-1.14), but increased medial rotation angle excursions (d = −1.06 to −0.91), compared to the healthy group. Lateral THA group had lower isometric hip abduction torque than the healthy group (P = .03, d = 0.74). There was no pelvic drop in the THA groups. ConclusionThere were few differences in gait and isometric torque between lateral and posterior THA groups. The elevated muscle activation amplitudes in the lateral and posterior THA groups compared to healthy adults were likely due to muscle weakness. Despite these findings, there was no evidence of pelvic drop.

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

BackgroundNerve 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.MethodsWe 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.ResultsWe 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).ConclusionsA 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 registrationClinicaltrials.gov: NCT03138668. Registered 3rd of May 2017.

Short-term outcomes of the supine muscle-sparing anterolateral versus direct lateral approach to primary total hip arthroplasty.

Although total hip arthroplasty (THA) is among the most successful orthopaedic procedures, it is not without complications. As such, finding the optimal surgical approach has become an area of particular interest. In this study, we compare: (1) pain intensity; (2) opioid consumption; (3) lengths of stay (LOS); (4) complication rates; (5) discharge destination; and (6) ambulatory function between patients who underwent THA via the supine muscle-sparing anterolateral (MS-ALA) and conventional direct lateral (DLA) approaches. A retrospective analysis was conducted on 220 consecutive patients who received primary THA using the supine MS-ALA (n = 101) or DLA (n = 119) between 1 January 2014 and 31 December 2016. Outcomes included postoperative pain intensity, opioid consumption, LOS, discharge destination, complications, additional procedures, and time to independent ambulation. We demonstrated significantly lower opioid consumption on postoperative days (POD) 1 and 2 (mean differences, -32.0 and -28.4 mg, respectively; p ⩽ 0.001) and decreased pain intensity during the second 24 hours of the hospital stay (mean difference, -22.0; p < 0.001) in patients receiving the MS-ALA. Relative to the DLA cohort, patients in the MS-ALA cohort were 2.04 times more likely to be discharged to home (p = 0.028) and 1.91 times less likely to experience postoperative abductor insufficiency (p = 0.039). The present study is the 1st to compare postoperative outcomes, particularly pain intensity and opioid consumption, between the supine muscle-sparing anterolateral and direct lateral THA approaches. Further research should investigate the effect of surgical approach on quality and cost of care, include larger sample sizes, and involve longer-term follow-up.

Patient-Specific Guides for Acetabular Prosthesis result in Better Hip ROMs: a 3D Regeneration Research

Objective: Orientation of the acetabular prosthesis is extremely relevant for total hip arthroplasty (THA) stability, which is usually predicted by hip range of motion (ROM). The desired acetabular cup orientation includes inclination of 40° and anteversion of 15°. The classical method uses mechanical alignment as a guide, which could be unstable and unreliable. Two anatomical structures, transverse acetabular ligament (TAL) and ischiadic-pubis line (IPL) have been suggested as patient-specific guide for orientations. The purpose of this study was to provide a basis for selection of an optimal guide for orientation in THA practice, by comparing these methods in THA simulation model. Materials and Methods: CT angiography of lower extremities from 47 participants (94 hips) treated at Union Hospital were imported to Mimics to regenerate pelvis and bilateral femurs. The desired orientation was inclination of 40° and anteversion of 15°. Bilateral acetabular prosthesis for each participant was guided by TAL and IPL, respectively. Inclinations and anteversions of the TAL and IPL guided prosthesis were measured and compared with the goal. Hip joints were rotated outward, inward, backward and forward to evaluate four parameters of hip ROMs, i.e. abduction, adduction, extension and flexion. Hip joints were manipulated to perform circumduction and to draw boundary map. Result. The mean inclinations generated by TAL and IPL guides were 36.35° and 36.90° respectively, which was significantly smaller compared to goal inclination (p=2.2×10-16 and p=2.2×10-16 respectively). The mean anteversions generated TAL and IPL guides were 23.09° and 20.93°, which was significantly larger compared goal anteversion (p=2.2×10-16 and 2.2×10-16 respectively). The analysis of ROMs showed compared with hip ROMs by goal orientations, both TAL and IPL guides led to increased abduction (38.25°±8.30° and 38.47°±8.00° respectively, p<2×10-16 and p<2×10-16, respectively) and flexion (98.47°±9.71° and 100.50°±10.44°, p<2.2×10-16 and p<2.159×10-16, respectively); while decreased abduction (38.25°±8.30° and 38.47°±8.00°, p<2×10-16 and p<2×10-16, respectively) and extension (27.66°±10.18° and 25.93°±9.29°, p<2×10-16 and p<2×10-16, respectively). Conclusion. Compared with the goal orientations, the use of TAL and IPL guides led to greater motion in flexion and adduction, and lower motions in abduction and extension, thus suggesting these guides might be more suitable for post lateral THA.

Gains and losses of small incision lateral total hip arthroplasty: what the patients want and its index case result

A poll was initially attempted to elucidate what type of skin incision would be preferred by the patients. The retrospective analysis of index cases was preformed to reveal the gains and losses of small incision transgluteal THA. We performed a poll on the preferred type of skin incision to the patients, their families and the medical personnel in orthopedic department in a face-to-face manner. According to the result of the poll, we changed approaches from a standard transgluteal to a small incision transgluteal approach. Each 20 consecutive index patients that underwent standard or small-incision transgluteal THA were followed and compared for more than 2 years. The small incision THA group showed more rapid mobilization, shorter hospital stay, and better early satisfaction. However, no clinical benefits of small incision were observed after 6-weeks postoperatively. There were significant variations in implant alignments. More early major complications such as dislocation, intraoperative femoral fracture or leg length inequalities occurred in the small incision group. The use of a small incision in THA resulted in subtle and temporary gains, at the cost of several major early complications. Now we perform THA with definitely smaller incision than before but we do believe that performing a stable and well-aligned THA is far more important than the length or amount of surgical dissection.