Instability After Total Hip Arthroplasty and the Role of Advanced and Robotic Technology

Fewer Dislocations After Total Hip Arthroplasty With Robotic Assistance or Fluoroscopic Guidance

BACKGROUND

Computer navigation and robotic assistance may reduce total hip arthroplasty (THA) dislocations by improving the accuracy and precision of component positioning. We investigated dislocation rates for THAs using conventional techniques, robotic assistance, and computer navigation, while controlling for surgical approach, dual mobility (DM) use, and fluoroscopic guidance.

METHODS

We reviewed 11,740 primary THAs performed between June 2016 and December 2022, including 5,873 conventional, 1,293 with robotic-arm assistance, and 4,574 with navigation. The approach was posterior in 6,580 (56.0%), anterior in 4,342 (37.0%), and lateral in 818 (7.0%). A DM was used in 10.4%. Fluoroscopy was used in 3,653 cases and only with the anterior approach. Multivariate analyses yielded odds ratios (OR) for dislocation and revision. Additional regression analyses for dislocation were performed for approach and DM.

RESULTS

Raw dislocation rates were as follows: conventional 1.2%, robotic 0.4%, navigation 0.9%, anterior with fluoroscopy 0.4%, anterior without fluoroscopy 2.3%, posterior 1.3%, and lateral 0.5%. Upon multivariate analysis, use of robotics was found to be associated with significantly reduced dislocation risk compared to conventional (OR: 0.3), as did anterior (OR: 0.6) compared to posterior approach; navigation and lateral approach were not found to be associated with a significant reduction in risk. For the anterior approach, multivariate analysis demonstrated that fluoroscopy significantly reduced dislocation risk (OR: 0.1), while DM, robotics, and navigation were not significant. For the posterior approach, the dislocation risk was lower with robotics than with conventional (OR: 0.2); the use of navigation or DM did not demonstrate a significant reduction in risk.

CONCLUSIONS

The use of robotics was associated with a reduction in dislocations for this cohort overall. Further, fluoroscopy in the anterior approach and robotic assistance in the posterior approach were both associated with decreased dislocation risk. The role of imageless computer navigation and DM implants requires further study.

The learning curve of a novel seven-axis robot-assisted total hip arthroplasty system: a randomized controlled trial

BACGROUND

The aim of this study was to assess the learning curve of a novel seven-axis robot-assisted total hip arthroplasty (RaTHA) system.

METHODS

A total of 59 patients who underwent unilateral total hip arthroplasty at our institution from June 2022 to September 2022 were prospectively included in the study. In this randomized controlled clinical trial, robot-assisted THA (RaTHA) and Conventional THA (CoTHA) were performed using cumulative sum (CUSUM) analysis to evaluate the learning curve of the RaTHA system. The demographic data, preopera1tive clinical data, duration of operation, postoperative Harris Hip Score (HHS), postoperative Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and duration of operation between the learning stage and the proficiency stage of the RaTHA group were compared between the two groups.

RESULTS

The average duration of operation of the RaTHA group was increased by 34.73 min compared with the CoTHA group (104.26 ± 19.33 vs. 69.53 ± 18.38 min, p < 0.01). The learning curve of the RaTHA system can be divided into learning stage and proficiency stage, and the former consists of the first 13 cases by CUSUM analysis. In the RaTHA group, the duration of operation decreased by 29.75 min in the proficiency stage compared to the learning stage (121.12 ± 12.84 vs.91.37 ± 12.92, p < 0.01).

CONCLUSIONS

This study demonstrated that the surgical team required a learning curve of 13 cases to become proficient using the RaTHA system. The duration of operation, total blood loss, and drainage gradually shortened (decreased) with the learning curve stage, and the differences were statistically significant.

TRIAL REGISTRATION

Number: ChiCTR2200061630, Date: 29/06/2022.

Evolution and New Generation of Dual Mobility Cups

Although total hip arthroplasty (THA) is considered a successful procedure, hip dislocation remains the main cause of early failure. Dual mobility cups (DMCs) have been shown to significantly reduce the dislocation rate in both primary and revision THAs. During the past several decades, DMCs have evolved in design and fixation interface. There have been three generations of DMCs. This article addresses the rationale for a new cementless highly porous titanium DMC to improve component fixation and implant biocompatibility. [Orthopedics. 2023;46(5):e273-e280.].

Precise acetabular positioning, discrepancy in leg length, and hip offset using a new seven-axis robot-assisted total hip arthroplasty system requires no learning curve: a retrospective study

Objective

The purpose of the present study was to determine the learning curve for a novel seven-axis robot-assisted total hip arthroplasty (RA-THA) system, and to explore whether it was able to provide greater accuracy in acetabular cup positioning, superior leg length discrepancy (LLD), and hip offset than conventional methods.

Methods

A total of 160 patients in which unilateral THA was performed in the second affiliated Hospital of Xi'an Jiaotong University from July 2021 to September 2022 were studied. The first 80 patients underwent robot-assisted THA, while conventional THA was performed on the subsequent 80 by the same team of experienced surgeons. The learning curve for the RA-THA system was evaluated using cumulative sum (CUSUM) analysis. The demographic data, preoperative clinical data, duration of surgery, postoperative Harris hip score (HHS) and postoperative radiographic data from patients that had conventional THA were compared.

Results

The 80 patients who underwent primary unilateral RA-THA comprised 42 males and 38 females and were followed up for 12 weeks. Using analysis by CUSUM, the learning curve of the RA-THA system could be divided into learning and proficiency phases, the former of which consisted of the first 17 cases. There was no significant difference between the learning and proficiency phases in terms of LLD, hip offset, or accuracy of acetabular prosthesis position in the RA-THA groups. The proportion of acetabular prostheses located in the Lewinnek safe zone was 90.5% in the proficiency group and 77.5% in the conventional group, respectively, a difference that was statistically significant (P < 0.05). The absolute error between target angle and postoperative measured angle of anteversion was statistically significant in the proficiency group and the conventional group((P < 0.05). Postoperative acetabular anteversion and LLD were 19.96 ± 5.68° and 6.00 (5.00) mm in the proficiency group, respectively, and 17.84 ± 6.81° and 8.09 (4.33) mm using conventional surgery, respectively (anteversion: P = 0.049; LLD: P < 0.001).

Conclusions

The surgical team required a learning curve of 17 cases using the RA-THA system to become proficient. There was no learning curve for other parameters, namely LLD, hip offset, or accuracy of acetabular prosthesis positioning. During the proficiency phase, the RA system was superior to conventional THA for control of leg length and accuracy of acetabular cup placement.

Achieving Target Cemented Femoral Stem Anteversion Using a 3-Dimensional Model

Background

Total hip arthroplasty aims to provide patients with a pain-free and stable hip joint through optimization of biomechanics such as femoral anteversion. There are studies evaluating the limits of cementless stem version, however, none assessing the range of version achieved by a cemented collarless stem. A computed tomography (CT)-based study was performed, utilizing a contemporary robotic planning platform to assess the amount of rotation afforded by a cemented collarless stem, whilst maintaining native biomechanics.

Methods

The study utilized 36 cadaveric hips. All had CT scans of the pelvis and hip joints. The CT scans were then loaded into a contemporary robotic planning platform. A stem that restored the patients native femoral offset was selected and positioned in the virtual femur. The stem was rotated while checking for cortical contact at the level of the neck cut. Cortical contact was regarded as the rotation limit, assessed in both anteversion and retroversion. Target range for stem anteversion was 10°-20°. Failure to achieve target version triggered a sequence of adjustments to simulate surgical decisions.

Results

Native femoral offset and target version range was obtained in 29 of 36 (80.5%) cases. Following an adjustment sequence, 4 further stems achieved target anteversion with a compromise in offset of 2.3 mm. Overall 33 of 36 (91.7%) stems achieved the target anteversion range of 10°-20°.

Conclusions

Target femoral stem anteversion can be achieved using a cemented, collarless stem in a CT-based 3-dimensional model in 80.5% of hips. With a small compromise in offset (mean 2.3 mm), this can be increased to 91.7%.

Anesthetic Effect of the Fascia Iliaca Compartment Block with Different Approaches on Total Hip Arthroplasty and Its Effect on Postoperative Cognitive Dysfunction and Inflammation

Objective

The objective of this article is to make a comparison of the anesthetic effects of the inside and outside fascia iliaca compartment block (FICB) in total hip arthroplasty (THA) and to study the effect of the different approaches of the FICB on postoperative cognitive dysfunction (POCD) and serum inflammatory cytokines in THA patients.

Methods

A total of 60 patients who received THA treatment from January 2021 to December 2021 were divided into two groups, namely, Inside group (inside approach of the FICB) and Outside group (outside approach of the FICB), according to the different approaches of the FICB. Forty-eight hours after surgery, we compared the use of ropacaine dosage, visual analogue scale (VAS) score, the use of patient-controlled analgesia (PCA), mini-mental state examination (MMSE) score, the incidence of POCD, and the serum levels of IL-1, IL-6. Secondary indicators include surgical indicators and the quality of anesthesia cannula.

Results

The ratio of re-fix the catheter, intubation time, and the use of ropacaine dosage at 48 h after surgery in the Outside group were significantly higher than that in the Inside group (p &lt; 0.05), while the depth of cannulation in the Outside group was significantly lower than that in the Inside group (p &lt; 0.05). VAS scores were comparable between the Inside and the Outside groups, except at 24 h after surgery. The use of PCA from 24 to 48 h after surgery in the Outside group was significantly higher than that in the Inside group (p &lt; 0.05). The MMSE score and the incidence of POCD in the Outside group were higher than that in the Inside group. At the same time, the serum IL-1β levels at 1 and 6 h after surgery and the serum IL-6 levels at 1, 6, 24, and 48 h after surgery in the Outside group were significantly higher than that in the Inside group (p &lt; 0.05).

Conclusion

Compared with the outside approach of the FICB, the inside approach of the FICB has better anesthetic effect, better postoperative analgesia, fewer postoperative analgesics, lower incidence of POCD, and lower serum cytokines during the treatment of THA patients.