Prevention of Dislocation After Total Hip Arthroplasty

Mid-term outcomes of total hip arthroplasty in patients younger than 30 years

INTRODUCTION

Total hip arthroplasty (THA) has predominantly been utilized to treat older patients with primary osteoarthritis. However, recent improvements in surgical technique and implant materials have increased implant longevity, making THA a viable option for younger patients (< 30 years old). While trend analyses indicate an expanding utilization of THA in younger patients with non-OA diagnoses, current data on mid- and long-term THA outcomes in this population are limited. This study aims to describe the demographics, perioperative data, and implant survivorship of patients younger than 30 years undergoing THA.

METHODS

A retrospective study across two large urban academic medical institutions identified 135 patients aged < 30 years who underwent 155 primary THAs between 2012 and 2017, with up to 10-year clinical follow-up. Baseline demographics, surgical indications, intraoperative details, and postoperative outcomes were analyzed.

RESULTS

The mean age at surgery was 24.9 years (range 18-29). Osteonecrosis of the femoral head (55.5%), developmental hip dysplasia (28.3%), and arthritis (15.5%) were the primary indications. Most surgeries utilized the posterior approach (64.5%), manual technique (65.8%), and Ceramic-on-Polyethylene articulation (71.6%). Seven patients (4.5%) were readmitted within 90-days of surgery, including three non-orthopedic-related readmissions (1.9%) and four orthopedic-related readmissions (2.6%). Dislocations were reported in two patients (1.3%). There were six all-cause revisions (3.9%), four aseptic (2.6%) and two septic (1.3%). Kaplan-Meier analysis showed 10-year survival from implant retaining reoperation was 98.7%, 10-year survival from all-cause revision was 96.1%, and 10-year survival from aseptic revision was 97.4%.

CONCLUSION

With a 10-year aseptic implant survivorship rate of 97.4%, THA is a reliable surgical intervention for patients younger than 30 years of age who have severe hip pathology. Further studies are warranted for a more comprehensive understanding of mid- and long-term survivorship risk factors in this demanding population, facilitating improved risk assessment and informed surgical decisions.

Efficacy of Dexamethasone in Reducing Pain and Inflammation and Accelerating Total Hip Arthroplasty Postoperative Recovery: A Randomized Controlled Trial

PURPOSE

To evaluate the efficacy of dexamethasone in reducing pain and accelerating recovery after total hip arthroplasty (THA).

DESIGN

A prospective randomized controlled trial.

METHODS

A total of 98 patients who underwent THA received either low-dose (10 mg) dexamethasone (dexa group) or isotonic saline (placebo group). C-reactive protein and interleukin-6 levels were recorded at 24, 48, and 72 hours after surgery. Pain visual analog scale (VAS) score at rest and walking, the incidence of postoperative nausea and vomiting (PONV), nausea VAS score, postoperative identity-consequence fatigue scale rating, antiemetic use, postoperative length of stay (PLOS), and complications were also recorded and compared.

FINDINGS

Inflammatory marker (C-reactive protein and interleukin-6) levels at 24, 48, and 72 hours postoperatively in the dexa group were lower than that in the placebo group (P < .05). After 24 hours of rest, the dynamic pain VAS scores in the dexa group were lower than those in the placebo group (P < .05). The incidence of PONV, nausea VAS score, and identity-consequence fatigue scale score in the dexa group were lower than those in the placebo group (P < .05), and the dosages of analgesics and antiemetics were also lower (P < .05). In addition, PLOS in the dexa group was shorter than that in the placebo group (P < .05). No significant difference in perioperative complications between the two groups was observed (P > .05).

CONCLUSIONS

Low-dose dexamethasone in the THA perioperative period can effectively reduce inflammatory marker levels, pain, nausea, postoperative fatigue, opioid analgesic use, and shorten PLOS without increasing complications.

Dual mobility in primary total hip arthroplasty: A temptation from the devil or a blessing from above

Dual mobility (DM) bearings have gained significant attention in the field of total hip arthroplasty (THA) as a valid treatment option in cases of revision for instability after THA whereas its use in primary THA is still a matter of debate. This manuscript explores the pathology, incidence, diagnosis, treatment options, prognosis, ongoing studies in the literature, and future perspectives related to the use of DM bearings employed in primary THA. DM bearings are primarily designed to address one of the major concerns in THA: Instability of the prosthetic hip. Instability is both for the surgeon and the patient a devastating postoperative complication, leading to significant pain and subsequent apprehension by the patient and may require revision surgeries. The use of DM implants poses the worry of wear-related complications, such as accelerated polyethylene wear and osteolysis, which also pose challenges to long-term implant survival. This technique has seen a steady rise in recent years, with multiple studies reporting favorable outcomes. The incidence of their utilization varies among institutions and surgeons, reflecting differing preferences and patient populations. The diagnosis of instability and wear-related complications in THA often involves clinical assessment, imaging modalities such as X-rays, computed tomography scans, and sometimes advanced imaging techniques like magnetic resonance imaging. DM bearings can be considered as an option when patients present neurologic pathologies such as Parkinson's disease or recurrent dislocations after THA. DM bearings provide an additional articulation point within the implant, facilitating a greater range of motion and inherent stability. This design allows for reduced risk of dislocation and improved functional outcomes. Various implant manufacturers offer different designs and sizes of DM bearings to suit individual patient needs. Current literature suggests that the use of DM bearings in primary THA has demonstrated promising outcomes in terms of enhanced stability, reduced dislocation rates, and improved patient satisfaction. However, long-term studies with larger patient cohorts are necessary to establish the durability and longevity of these implants. Several ongoing studies are investigating the role of DM bearings in primary THA. These studies focus on evaluating long-term implant survivorship, assessing wear patterns, analyzing patient-reported outcomes, and comparing the effectiveness of DM bearings with traditional THA designs. The future of DM bearings in primary THA holds potential for further advancements. Research efforts are aimed at refining implant materials, optimizing designs, and studying the influence of surgical techniques on implant performance. Additionally, continued investigation into the long-term outcomes and cost-effectiveness of DM bearings will play a crucial role in shaping their future use. While further research is warranted, the current evidence supports their potential as a beneficial solution in improving surgical outcomes and patient satisfaction.

Dislocation of primary total hip arthroplasty: Analysis of risk factors and preventive options

Total hip arthroplasty (THA) is one of the most successful elective operations in orthopedic surgery for improving pain and functional disability in patients with end-stage joint disease. However, dislocation continues to be a troublesome complication after THA, as it is a leading cause of revision and is associated with substantial social, health, and economic costs. It is a relatively rare, usually early occurrence that depends on both the patients' characteristics and the surgical aspects. The most recent and important finding is the special attention to be given preoperatively to spinopelvic mobility, which is closely related to the incidence of dislocation. Consequently, clinical and radiographic assessment of the lumbar spine is mandatory to identify an altered pelvic tilt that could suggest a different positioning of the cup. Lumbar spinal fusion is currently considered a risk factor for dislocation and revision regardless of whether it is performed prior to or after THA. Surgical options for its treatment and prevention include the use of prostheses with large diameter of femoral head size, dual mobility constructs, constrained liners, and modular neck stems.

Risk factors for complications in total hip arthroplasty

INTRODUCTION AND OBJECTIVE

Hip arthroplasty represents a significant advancement in the treatment of refractory chronic joint pain, improving quality of life and functionality. The objective of this study is to identify the risk factors associated with local and systemic complications in patients treated with total hip arthroplasty.

METHODS

Observational, analytical, retrospective cohort study, which included 304 participants treated with total hip replacement. Comparison of variables between two groups was performed; 38 participants in the group with complications and 266 participants in the group without complications.

RESULTS

The mean age in the complication group was 66 years (SD 18.7) and in the uncomplicated group it was 67,1 years (SD 15.1) (p 0,686). Female sex was observed in 73.3% of the group with complications and 65% in the group without complications. (p 0.292). Risk factors were: hip fracture as an indication for arthroplasty RR 1.33 [95% CI 1.004;1.775 p 0.047], coronary heart disease RR 1.31 [95% CI 1.067;1.616 p 0.010] and surgical bleeding equal to or greater than 400 cc RR 1.11 [95% CI 1.012;1.218 p 0.028].

CONCLUSIONS

The risk factors for complications in total hip arthroplasty were: hip fracture as the indication for arthroplasty, coronary artery disease, and surgical bleeding equal to or greater than 400 cc.

Multivariate Analysis of Risk Factors for In-Hospital Dislocation Following Primary Total Hip Arthroplasty

Background: Early dislocation following primary total hip arthroplasty (THA) is a rare but devastating complication and represents a source of patient morbidity and financial burden to the healthcare system. The objective of this study was to identify patient characteristics and comorbidities that are associated with increased early in-hospital dislocation rates following primary THA. Methods: A retrospective cohort study was conducted using patient data from the Nationwide Inpatient Sample (NIS) database; we identified patients who had undergone THA from 2016 to 2019 and compared those with an early periprosthetic dislocation prior to discharge to those without. The patient characteristics and comorbidities were compared using univariate analysis with a subsequent investigation of statistically significant variables using multivariate analysis. The variables were compared using chi square, Fisher's exact test, and independent sample t-tests with data assessed using odds ratio with 95% confidence intervals. Results: A total of 5151 patients sustained an early dislocation compared to 362,743 who did not. Those who sustained an in-hospital dislocation were more likely to share the following characteristics: female sex (OR 1.21, p < 0.01), age > 70 (OR 1.45, p < 0.01), Caucasian ethnicity (OR 1.22, p < 0.01), SLE (OR 1.87, p < 0.01), and Parkinson's disease (OR 1.93, p < 0.01). Certain characteristics were also associated with decreased odds of having an in-hospital dislocation including elective surgery (OR 0.14, p < 0.01), tobacco use (OR 0.8, p < 0.01), diabetes without complications (OR 0.87, p < 0.01), and a history of heart valve replacement (OR 0.81, p < 0.01). The length of stay was significantly longer (4.7 days vs. 2.3 days) as was the total hospital charges (USD $101,517 vs. USD $66,388) for the early in-hospital dislocation group. Conclusions: Several patient characteristics and comorbidities are associated with early in-hospital dislocation episodes following total hip arthroplasty including female sex, age > 70, non-elective surgery, SLE, and Parkinson's. This information may be useful to help guide intraoperative implant selection and/or postoperative protocol in select patient populations to limit early instability as well as decrease the financial burden associated with this postoperative complication.

Individualized Surgeon Reports in a Statewide Registry

ABSTRACT

Despite progress with the development of joint replacement registries in the United States, surgeons may have limited opportunities to determine the cumulative outcome of their own patients or understand how those outcomes compare with their peers; this information is important for quality improvement. In order to provide surgeons with accurate data, it is first necessary to have a registry with complete coverage and patient matching. Some international registries have accomplished this. Building on a comprehensive statewide registry in the United States, a surgeon-specific report has been developed to provide surgeons with survivorship and complication data, which allows comparisons with other surgeons in the state. This article describes funnel plots, cumulative sum reports, complication-specific data, and patient-reported outcome measure data, which are provided to hip and knee arthroplasty surgeons with the goal of improving quality, decreasing variability in the delivery of care, and leading to improved value and outcomes for hip and knee arthroplasty in the state of Michigan.

Does the limb lengthening reduce the incidence of hip dislocation in patients with neurological disorders and insufficient muscle tension who undergoing hip arthroplasty?

Background

The soft-tissue tension is closely associated with postoperative hip dislocation in patients undergoing total hip arthroplasty (THA), especially for those patients with neurological disorders and insufficient muscle tension. The aim of this study is to explore the effect of limb lengthening on the incidence of complications following THA in patients with neurological disorders and insufficient muscle tension.

Methods

This retrospective analysis examines individuals with neurological disorders, such as ischemic stroke and poliomyelitis, who underwent primary total hip arthroplasty (THA) at our medical center between January 2015 and April 2021. Demographic and baseline characteristics (such as age, gender, muscle strength) were obtained from medical records. The limb length, offset and the positional parameters of both acetabular and femoral component were measured on pre- and postoperative plain radiograph. The primary outcome was the occurrence of hip dislocation. The secondary outcome included the incidence of other complications and the hip function (determined by Harris score). The correlation between the occurrence of hip dislocation and limb lengthening was analyzed.

Results

A total of 258 patients were finally analyzed. The hip dislocations were identified in 35 patients (overall incidence = 13.57%). The incidence of early dislocation was lower in patients whose limb-length discrepancy (LLD) was over 20 mm (incidence = 4.1% for LLD >20 mm, 12.2% for LLD 10 mm-20 mm and 17% for LLD <10 mm). The odds ratio (OR) was 0.206 and 95% confidence interval (CI) was 0.058-0.737 (compared between LLD <10 mm and LLD >20 mm). But the no difference was identified regarding on the incidence of late dislocation among patients with different LLD. Moreover, the overall incidence of other complications was elevated in patients with LLD >20 mm (incidence = 17.58% for LLD >20 mm, 11.11% for LLD 10 mm-20 mm and 3.19% for LLD <10 mm; OR = 6.464, 95% CI = 1.768-23.640). And the Harris scores, which reflected the hip function, was gradually decreased with the increasing in LLD. In terms of the relationship between the offset and dislocation rate, it was found that increased offset discrepancy was associated with decreased dislocation incidence (incidence = 4.71% for offset discrepancy >10 mm, 12.5% for offset discrepancy 5 mm-10 mm and 17.20% for offset discrepancy <5 mm; OR = 0.238, 95% CI = 0.076-0.742). Furthermore, increased offset discrepancy also bring a reduction in late dislocation. The incidences of late dislocation were 0%, 2.5% and 10.8% for offset discrepancy >10 mm, offset discrepancy 5 mm-10 mm and 17.20% for offset discrepancy respectively. Different from that of LDD, the incidences of other complications were similar among patients with different offset discrepancy. Besides, no influence of offset discrepancy on the hip function was identified in this study.

Conclusion

Unfortunately, although increasing in limb length could partially reduce early dislocation postoperatively, it could not affect the incidence of late dislocation in those patients with neurological disorders and insufficient muscle tension. Moreover, over limb lengthening was associated with other postoperative complications and worse hip function. Instead, additional offset could reduce the probability of postoperative dislocation, without increasing the incidence of other complications. Therefore, femoral stem with lower cervico-diaphyseal angle (higher offset) should be recommended to patients with neurological disorders who were in high risk of postoperative dislocation. Isolated increasing in limb length should be avoided.

Predictors of Reoperation and Survival Experience (Minimum 1 Year) for Primary Versus Conversion Total Hip Arthroplasty in Young Patients

BACKGROUND

Total hip arthroplasty (THA), including primary and conversion procedures, is commonly used for many types of joint disease in patients aged below 65 years, though few studies have evaluated THA outcomes in young patients (≤ 40 years old). This study examined a large cohort of patients who underwent THA at a young (≤ 40 years old) age to identify predictors of reoperation and compare survivorship between primary and conversion THAs.

METHODS

A retrospective study was conducted on 497 patients who underwent 612 primary and conversion THAs at 40 years old or younger between 1990 and 2020. Medical records were reviewed to collect patient/surgical data. A multivariable logistic regression model identified independent predictors of reoperation, and Kaplan-Meier analysis with log-rank tests was used to compare survival curves by THA type.

RESULTS

The median age at surgery (interquartile range) was 31 years (25 to 36). The median follow-up time was 6.6 years (range, 3.8 to 10.5). Conversion THAs had an increased rate of both revisions (12.3 versus 5.6%, P = 0.02) and nonrevision reoperations (8.9 versus 3.2%, P = 0.03) compared to primary THAs. A ceramic-on-ceramic articulation (odds ratio: 5.17; P = 0.03) and a higher estimated blood loss (odds ratio: 1.0007; P = 0.03) were independent predictors of reoperation for primary and conversion THA, respectively. Conversion THAs had a lower 15-year survival (77.8 versus 90.8%, P = 0.009) compared to primary THAs.

CONCLUSIONS

Patients ≤ 40 years old who underwent primary and conversion THAs demonstrated an impressive 15-year survival comparable to that of older populations (74 to 93%), while conversion procedures had a higher reoperation rate. Although primary THA may be more ideal, there are promising outcomes for patients who need THA at a younger age than typically implemented, especially for those who are very young (≤ 30 years old).

Fretting and Tribocorrosion of Modular Dual Mobility Liners: Role of Design, Microstructure, and Malseating

BACKGROUND

Modular dual mobility (DM) bearings have a junction between a cobalt chrome alloy (CoCrMo) liner and titanium shell, and the risk of tribocorrosion at this interface remains a concern. The purpose of this study was to determine whether liner malseating and liner designs are associated with taper tribocorrosion.

METHODS

We evaluated 28 retrieved modular DM implants with a mean in situ duration of 14.6 months (range, 1 to 83). There were 2 manufacturers included (12 and 16 liners, respectively). Liners were considered malseated if a distinct divergence between the liner and shell was present on postoperative radiographs. Tribocorrosion was analyzed qualitatively with the modified Goldberg Score and quantitatively with an optical coordinate-measuring machine. An acetabular shell per manufacturer was sectioned for metallographic analysis.

RESULTS

There were 6 implants (22%) that had severe grade 4 corrosion, 6 (22%) had moderate grade 3, 11 (41%) had mild grade 2, and 5 (18.5%) had grade 1 or no visible corrosion. The average volumetric material loss at the taper was 0.086 ± 0.19 mm3. There were 7 liners (25%) that had radiographic evidence of malseating, and all were of a single design (P = .01). The 2 liner designs were fundamentally different from one another with respect to the cobalt chrome alloy type, taper surface finish, and shape deviations. Malseating was an independent risk factor for increased volumetric material loss (P = .017).

CONCLUSIONS

DM tribocorrosion with quantifiable material loss occurred more commonly in malseated liners. Specific design characteristics may make liners more prone to malseating, and the interplay between seating mechanics, liner characteristics, and patient factors likely contributes to the shell/liner tribocorrosion environment.

LEVEL OF EVIDENCE

Level III.

A new designed full process coverage robot-assisted total hip arthroplasty: a multicentre randomized clinical trial

OBJECTIVE

To compare the effect of a new complete robot-assisted total hip arthroplasty (RA-THA) with that of the manual total hip arthroplasty (MTHA) and to verify the accuracy and safety of the former.

METHODS

Overall, 148 patients were enroled from 3 March 2021 to 28 December 2021 in this study and classified into RA-THA ( n =74 patients) and MTHA ( n =74 patients) groups. The sex, age, operative side, BMI, diagnosis, other basic information, operative time, acetabular prosthesis anteversion and inclination, femoral prosthesis anteversion and angulation, femoral prosthesis filling rate, leg length discrepancy (LLD), Harris hip score, and visual analogue scale (VAS) score of the two groups were compared.

RESULTS

No significant differences were observed in the two groups regarding sex, age, operative side, BMI, diagnosis, Harris hip score, VAS score, acetabular inclination, acetabular prosthesis anteversion, femoral prosthesis anteversion, combined anteversion, and femoral prosthesis filling rate ( P >0.05). The operative time was significantly longer in the RA-THA group than in the MTHA group (106.71±25.22 min vs. 79.42±16.16 min; t=7.30, P <0.05). The femoral angulation (1.78°±0.64°) and LLD (2.87±1.55 mm) in the RA-THA group were significantly lesser than those in the MTHA group (2.22°±1.11° and 5.81±6.27 mm, respectively; t=-2.95 and t=-3.88, P <0.05).

CONCLUSION

The complete RA-THA has some advantages over the traditional procedure in restoring the lower limb length and controlling the femoral prosthesis angulation. Thus, this study verifies the accuracy and safety of the robot-assisted system.

Dislocation Following Anterior and Posterior Total Hip Arthroplasty in the Setting of Spinal Deformity and Stiffness: Evolving Trends Using a High-Risk Protocol at a Single Tertiary Center

BACKGROUND

Patients who have spinal stiffness and deformity are at the highest risk for dislocation after total hip arthroplasty (THA). Previous reports of this cohort are limited to antero-lateral and postero-lateral (PL) approaches. We investigated the dislocation rate after direct anterior (DA) and PL approach THA with a contemporary high-risk protocol to optimize stability.

METHODS

We investigated patients undergoing THA who had preoperative biplanar imaging from January-December 2019. Patients were identified using radiographic criteria of spinal-stiffness (<10-degree change in sacral slope from standing to seated) and deformity (flatback deformity with >10-degree difference in pelvic incidence and lumbar lordosis). There were 367 patients identified (181 DA, 186 PL). The primary outcome was dislocation rate at 2-years postoperatively. Risk-factors for dislocation were evaluated using logistic regressions (significance level of 0.05).

RESULTS

There were 6 (1.6%) dislocations in the entire cohort, with low dislocation rates for both DA (0.6%) and PL-THA (2.7%). We observed increased utilization of dual mobility with larger outer head bearings (>38 mm) with PL-THA (34.4 versus 5.0%, P < .01) and conversely increased utilization of 32-mm femoral-heads with DA-THA (39.4 versus 7.0%, P < .001). Surgical approach (PL) was not a significant risk-factor for dislocation (odds ratio: 5.03, P = .15). Patients who had a history of lumbar-fusion had 8-times higher odds for dislocation (OR: 8.20, P = .020).

CONCLUSIONS

To the best of our knowledge, this is the largest series to date evaluating DA and PL-THA in the hip-spine 2B-group. Our results demonstrate lower dislocation rate than expected with either surgical approach using a high-risk protocol.

A prospective and consecutive study assessing short-term clinical and radiographic outcomes of Chinese domestically manufactured 3D printing trabecular titanium acetabular cup for primary total hip arthroplasty: evaluation of 236 cases

Purpose

We prospectively evaluate the short-term clinical and radiographic outcomes of the only Chinese domestically produced trabecular titanium acetabular cup(3D ACT™ cup) in primary total hip arthroplasty (THA), aiming to provide evidence-based support for its clinical application.

Methods

A total of 236 patients, who underwent primary THA using 3D ACT™ cup in the Department of Joint Surgery at our hospital between January 2017 and June 2019, were included in this study. General patient data, imaging information, functional scores, and complications were collected to evaluate the early clinical efficacy.

Results

All patients were followed up for 33-52 months, with an average of (42.2 ± 9.2) months. At the last follow-up, the preoperative HHS score increased significantly from 43.7 ± 6.8 to 85.6 ± 9.3 points (P < 0.01). Similarly, the preoperative WOMAC scores showed significant improvement from 59.2 ± 5.8 to 13.1 ± 3.5 points (P < 0.01). 92.3% of the patients expressed satisfaction or high satisfaction with the clinical outcome. Furthermore, 87.7% of the acetabular cups were positioned within the Lewinnek safe zone, achieving successful reconstruction of the acetabular rotation center. The cup survival rate at the last follow-up was 100%.

Conclusions

The utilization of the only Chinese domestically manufactured 3D printing trabecular titanium acetabular cup in primary THA demonstrated favorable short-term clinical and radiographic outcomes. The acetabular cup exhibits excellent initial stability, high survival rate, and favorable osseointegration, leading to a significant enhancement in pain relief and functional improvement. In the future, larger sample sizes and multicenter prospective randomized controlled trials will be required to validate the long-term safety and effectiveness of this 3D ACT™ cup.

Clinical outcomes in patients with neurological disorders following periacetabular tumor removal and endoprosthetic reconstruction of the hemipelvis

Background

Surgical treatment of musculoskeletal tumors in the periacetabular region present extremely difficult due to the complex anatomy and need for reconstruction. Orthopedic surgeons face more difficulties in patients with neurological conditions, which can cause increased muscle tone, an elevated risk of fractures, and compromised bone quality. There is limited evidence regarding endoprosthetic reconstruction for periacetabular tumors in individuals with neurological disorders.

Methods

We conducted a single-center retrospective study to examine the outcomes of patients with preexisting neurological conditions who underwent surgery to remove periacetabular tumors and who underwent endoprosthesis reconstruction. Clinical presentation, detailed neurological conditions, complications, and functional outcomes were studied.

Results

Sixteen out of the 838 patients were identified (1.91%), with a mean follow-up time of 33 months. The primary neurological conditions encompassed Parkinson's disease, Alzheimer's disease, dementia, and cerebral ischemic stroke. Every patient was diagnosed with periacetabular lesions that were either primary or oligometastatic. They underwent tumor resection and subsequently received endoprosthetic reconstruction of the hemipelvis. Three patients developed metastasis lesions later, and two patients experienced tumor recurrence. Five cases experienced hip dislocation-one with periprosthetic fracture and one with surgical site infection. The position of the prosthetic rotating center was not correlated with dislocation. The reoperation rate was 31.25%. The cohort of patients all presented with more extended hospital stays and rehabilitation. In 3 patients, the general functional score was good, while in 6 patients, it was fair; in 7 patients, it was regarded as poor. The average MSTS93 score was 49.71%.

Conclusion

Endoprosthetic reconstruction after periacetabular tumor resection is an effective way to eliminate tumors and salvage limbs. However, this group of patients has an increased likelihood of secondary surgery, complications, extended hospital stay, and no significant improvement in functional outcomes. Despite the diverse nature of the cohort, it is recommended to consider enhanced soft tissue reconstruction, supervised functional recovery and rehabilitation training.

Are Synovial Inflammatory Markers Increased in Patients Who Have Aseptic Total Hip Arthroplasty Dislocation Indicated for Revision?

BACKGROUND

Previous studies have speculated on elevated synovial inflammatory markers in patients undergoing surgical revision for total hip arthroplasty (THA) dislocation. However, this assumption is based on small patient series and a full investigation according to International Consensus Meeting (ICM) criteria has not yet been performed.

METHODS

Patients who had aseptic THA dislocation indicated for revision surgery were identified retrospectively. Only patients who had available diagnostic workup according to ICM 2018 criteria, including preoperative and intraoperative parameters, were included. For comparison, we analyzed a matched cohort of patients indicated for aseptic THA revision for other conditions. The 2 cohorts each consisted of 55 patients and were not different regarding age, sex, BMI, or implant fixation.

RESULTS

There was no difference in synovial white blood cell count (2,238 ± 2,544 versus 2,533 ± 3,448 c/μL; P = .601), alpha-defensin quotient (0.14 ± 0.11 versus 0.19 ± 0.28; P = .207), or polymorphonuclear neutrophil percentage (% PMN) (36.7 ± 22.6 versus 31.3 ± 24.5%; P = .312) between the groups. In the dislocation cohort, 20% of patients had a synovial white blood cell count of 3,000 c/μL or higher, compared with 18% in the control cohort. However, all patients in the dislocation cohort were below the cutoff for alpha-defensin or % PMN.

CONCLUSION

In patients who have aseptic THA dislocation, synovial inflammatory markers are not elevated compared with patients undergoing aseptic revision for other complications. A detailed preoperative analysis of synovial inflammatory markers using ICM criteria appears critical in patients who have a THA dislocation to exclude periprosthetic joint infection.

LEVEL OF EVIDENCE

Level III, retrospective, comparative study.

Evaluating computed bony range of motion (BROM) by registering in-vitro cadaver-based functional range of motion (FROM) to a hip motion simulation

BACKGROUND

While modern hip replacement planning relies on hip motion simulation (HMS), it lacks the capability to include soft-tissues and ligaments restraints on computed bony range of motion (BROM), often leading to an overestimation of the in-vivo functional range of motion (FROM). Furthermore, there is a lack of literature on BROM assessment in relation to FROM. Therefore, the study aimed to assess computed BROM using in-vitro cadaver-derived FROM measurements, registered to a CT-based in-house HMS, and to further investigate the effect of functional and anatomical hip joint centres (FHJC and AHJC) on BROM.

METHOD

Seven limiting and three non-limiting circumducted passive FROM of four cadaver hips were measured using optical coordinate measuring machine with reference spheres (RSs) affixed to the pelvis and the femur, following CT-scan of the specimen. The RSs' centres were used to register the measured FROM in HMS, enabling its virtual recreation to compute corresponding BROM by detecting nearest bony impingement. FHJC, estimated from non-limiting FROM, was compared with AHJC to examine their positional differences and effect on BROM.

RESULTS

Differences in BROM and FROM were minimal in deep flexion (3.0° ± 4.1°) and maximum internal rotation (IR) at deep flexion (3.0° ± 2.9°), but substantially greater in extension (53.2° ± 9.5°). Bony impingement was observed during flexion, and IR at deep flexion for two hips. The average positional difference between FHJC and AHJC was 3.1 ± 1.2 mm, resulting in BROM differences of 1°-13° across four motions.

CONCLUSIONS

The study provided greater insight into the applicability and reliability of computed BROM in pre-surgical planning.

The Empty Ischial Fossa Sign: A Visual Representation of Relative Inadequate Anteversion in the Posteriorly Tilted Pelvis

Background

Instability is a known complication following total hip arthroplasty (THA) and is influenced by spinopelvic alignment. Radiographic markers have been investigated to optimize the acetabular cup position. This study evaluated if the empty ischial fossa (EIF) sign and the position of the trans-teardrop line were predictive of postoperative instability.

Methods

All patients who underwent THA from 2011 to 2018 at a single institution were retrospectively reviewed. Pelvic tilt was measured using a trans-teardrop line compared to the superior aspect of the pubic symphysis on standing anteroposterior pelvis radiographs. Postoperative dislocations were identified through chart review and radiographic review. The EIF sign was determined by the presence of uncovered bone below the posterior inferior edge of the acetabular component at the level of the native ischium and posterior wall on standing postoperative anteroposterior radiographs.

Results

One thousand seven hundred fifty patients (952 anterior approach and 798 posterior approach) were included. The EIF sign was present in 458 patients (26.2%) and associated with an increased dislocation rate (3.9% vs 0.9%, P < .0001). Patients with spondylosis/instrumented fusion, and positive EIF sign had a dislocation risk of 5.1% vs 1.3% (P = .001). A postoperative outlet pelvis was not significant for increased dislocation risk (odds ratio 2.16, P = .058). Patients with combined spondylosis/fusion, posterior approach, outlet pelvis, and EIF sign had a dislocation rate of 14.5%.

Conclusions

The EIF sign was an independent risk factor for postoperative instability and may represent failure to account for pelvic tilt. Avoidance of the EIF sign during cup positioning may help reduce dislocations following THA.

An analysis of the prevalence and risk factors of deep vein thrombosis in non-fracture patients awaiting total hip arthroplasty: a retrospective study of 1244 cases

BACKGROUND

Deep vein thrombosis (DVT) has been one of the most dangerous complications in total hip arthroplasty (THA). If a patient's pre-surgical DVT is overlooked, it can easily be mistaken for a post-operative thrombus and lead to an increased risk of DVT during and after surgery. This retrospective study was to explore the incidence and associated risk factors of deep vein thrombosis (DVT) in non-fracture patients before total hip arthroplasty (THA).

METHODS

From September 2015 to September 2020, 1242 patients admitted for THA were enrolled with 1120 patients (90.2%) for primary THA and 122 patients (9.8%) for revision THA. An experienced sonographer performed a bedside ultrasound to detect DVT in bilateral lower limbs preoperatively. Univariate and logistic regression analysis was performed to identify the independent risk factors.

RESULTS

38 patients (3.1%) were detected with preoperative DVT. Univariate analysis showed that age (P < 0.001), D-dimer level (P = 0.002), female patients (P = 0.016), revision THA (P < 0.001), Barthel Index score (P = 0.010) were significantly associated with preoperative DVT. In subgroup comparison, the incidence of DVT increased with age significantly (P < 0.001) and D-dimer level (P < 0.001). In logistic regression analysis, age ≥ 75 years old (odds ratio [OR] 3.678, 95% CI [2.197-18.721], P < 0.001), gender (OR 2.709, 95% CI [1.244-5.896], P = 0.012), higher D-dimer ≥ 0.5 mg/l (OR 6.841, 95% CI [2.197-18.721], P < 0.001) and revision THA (OR 2.240, 95% CI [1.143-5.372], P = 0.05) were confirmed as the independent risk factors.

CONCLUSIONS

The incidence of preoperative DVT in non-fracture patients was 3.1%, with 2.4% in primary THA and 9.0% in revision THA. Age ≥ 75 years old, female, D-dimer ≥ 0.5 mg/l, and revision THA were independent risk factors. When evaluating the risk factors associated with thrombus formation preoperatively, it is important to take these into account before surgery.

Clinical reasoning for the continuation or discontinuation of hip precautions after total hip arthroplasty in Switzerland: a qualitative study

BACKGROUND

Growing evidence raises doubts about the need for routine hip precautions after primary total hip replacements to reduce the risk of postoperative dislocation. However, hip precautions are still routinely and widely prescribed in postoperative care in Switzerland. We aimed to investigate experts' clinical reasoning for hip precaution recommendations after total hip arthroplasty.

METHODS

Using a convenience sampling strategy, 14 semi-structured expert interviews were conducted with surgeons, physiotherapists, and occupational therapists in the vicinity of an inpatient rehabilitation clinic in Switzerland. Data analysis followed Mayring's principle of inductive and deductive structuring content analysis.

RESULTS

Expert statements from the interviews were summarised into four main categories and 10 subcategories. Categories included statements on the incidences of dislocation and underlying risk factors; current preferences and use of hip precautions; their effect on physical function, anxiety, or costs; and patient's adherence to the movement restrictions. Hip surgeons routinely prescribed hip precautions, although in different variations. Fear of dislocation and caution are barriers to changing current practice. Some surgeons are considering individualised prescribing based on patients' risk of dislocation, which therapists would welcome.

CONCLUSION

A lack of clear instructions from the surgeon leads to ambiguity among therapists outside the acute hospital. A shared understanding of the need for and nature of hip precautions, guidelines from societies, or at least specific instructions from surgeons to therapists are warranted.

Bilateral Total Hip Prosthesis in Coxarthritis of Inflammatory Origin: Technical Features and Intraoperative Complications Encountered in Five Cases

Total hip arthroplasty remains the treatment of last resort in inflammatory coxarthritis, where joint destruction is bilateral as well as the treatment which must be bilateral. We present in this work the experience of our orthopaedic department with a series of five cases (10 hips) operated for total hip arthroplasty. the first particularity observed in this series is the abnormal bone fragility present in 55% of the cases. For this reason, we had two other intraoperative complications that are related to this bone fragility, during the preparation of the acetabulum, we had a destruction of the medial wall by the burr that went unnoticed intraoperatively and was discovered during the patient's recovery from acute ischemia secondary to the burr, which led to an extensive rupture of the common femoral vein and partial sectioning of the common femoral artery. We also had an exceptional incident in a case with two ankylosed hips; in fact, when the approach was performed, the sciatic nerve was found pressed against the posterior surface of the greater trochanter, which was unusual but was explained by the retraction of the structures of the gluteal region secondary to prolonged immobilization. Thus, there was one case of cement shock manifested by hypotension occurring immediately after cement placement. In front of this inflammatory disease and ankylosis terrain, the surgeon must always be prepared for any complication and must keep in mind that he is operating on a hip that is anatomically not normal due to ankylosis and retraction of the vascular, nerve, and muscle structures.

Soft-tissue tension during total hip arthroplasty measured in four patients and predicted using a musculoskeletal model

PURPOSE

Soft-tissue tension around the hip joint is related to the incidence of dislocation after total hip arthroplasty (THA), but it remains difficult to quantify the soft-tissue tension during surgery. In this study, a three-dimensional force sensor-instrumented modular femoral head was developed and used to quantify soft-tissue tension during THA. The forces at the hip joint were also calculated using a three-dimensional musculoskeletal computer model to validate the measured forces.

METHODS

Soft-tissue tension was investigated by measuring the hip joint forces and directions during intraoperative trialing in four patients through passive range of motion (ROM) from 0° extension to 90° flexion. A musculoskeletal model with THA, which was scaled to one of four patients, was developed. The hip joint forces were calculated under the same motion.

RESULTS

Through the passive ROM, the magnitude of soft-tissue tension was greatest when the hip was extended, decreased with flexion to 34°, and progressively increased to flexion at 90°. The mediolateral force component was relatively constant, but the supero-inferior and anterior-posterior force components changed significantly. Within-individual variations were small during three repeated cycles of measurement, but magnitudes varied significantly among patients. Similar force patterns and magnitudes were calculated by the musculoskeletal model.

CONCLUSIONS

This study demonstrates that it is possible to quantify soft-tissue tension and direction during THA with an instrumented head. There was general agreement between the calculated and measured forces in both pattern and magnitude. Including additional subject-specific details would further enhance agreement between the model and measured hip forces.

Accuracy of Preoperative 3D vs 2D Digital Templating for Cementless Total Hip Arthroplasty Using a Direct Anterior Approach

Background

An important aspect of preoperative planning for total hip arthroplasty is templating. Although two-dimensional (2D) templating remains the gold standard, computerized tomography (CT)-based three-dimensional (3D) templating is a novel preoperative planning technique. This study aims to compare the accuracy of a 2D and 3D plan using an anterior approach for the placement of the same uncemented prosthesis.

Methods

Two consecutive cohorts of 100 patients each were retrospectively analyzed. We analyzed the accuracy of the size of the implant (stem, cup, head), the length of head, and offset. As a secondary criterion, we analyzed the rates of stems with more than 3° of varus, fracture, and/or subsidence at 3 months postoperatively.

Results

Within the exact size, the accuracy of the stem and cup size with the 2D plan was 69% and 56%, respectively. With the 3D plan accuracy being 88% (P = .0046) and 96% (P < .0001), respectively. Regarding size and length of the implant head, accuracy was 86% and 82% with the 2D plan and 100% (P < .0001) and 94% (P = .016), respectively, with the 3D plan. The offset of the implants increased beyond 3 mm in 23% of patients in the 2D group and in 5% of patients in the 3D group (P = .0003). The rate of varus stems was 10% in the 2D group and 2% in the 3D group (P = .03). Two fractures and one case of subsidence occurred in the 2D group. None were identified in the 3D cohort.

Conclusions

A CT-based 3D plan is more accurate for implant size selection, allows better prosthetic offset, and reduces the rate of varus stems.

Accuracy and safety of a new robotic arm for both femoral and acetabular side in total hip arthroplasty: a cadaveric study

BACKGROUND

To investigate the accuracy and safety of a newly constructed robotic arm which can cover the whole process of THA, we performed a series of robot-assisted total hip replacement on the cadaver.

METHODS

Fifteen frozen cadaveric specimens (30 hips) were used for this study. In this investigation, united hip system and Longwell robotic-assisted system were used. The entire lower limb was CT scanned prior to surgery. The 3D model was produced based on CT data; the site of the prosthesis, including acetabular anteversion, inclination angle, and the position of femoral prosthesis, was planned. With the assistance of a robotic arm, the surgeon changed the parameters based on the preoperative plan and the actual condition during surgery, and completed the whole procedure. Following surgery, we measured the acetabular anteversion angle, acetabular inclination angle, femur anteversion angle, combined anteversion angle, stem angulation, and canal fill ratio.

RESULTS

The parameters proved that the acetabular anteversion angle was 16.85 ± 3.00°, the acetabular inclination angle was 40.38 ± 5.37°, femur anteversion angle was 15.90 ± 9.01°, combined anteversion angle was 32.75 ± 9.03°, stem angulation was 1.84 ± 0.99°, and leg length discrepancy was 2.47 ± 1.43 mm. The canal fill ratio (CFR) of femoral prosthesis of osteotomy line in sagittal section is 99.72 ± 1.54% and in coronal section is 62.94 ± 8.91%; below osteotomy line 2.5 cm in sagittal section is 100.00% and in coronal section is 81.48 ± 12.94%; below osteotomy line 7.5 cm in sagittal section is 59.51 ± 12.94% and in coronal section is 89.79 ± 11.13%; femoral shaft isthmus in sagittal section is 56.41 ± 13.80% and in coronal section is 84.95 ± 15.17%.

CONCLUSION

The accuracy and safety of this novel robotic arm are suitable for preparing both the acetabular and femoral sides, providing evidence for clinical trial.

A novel algorithm to efficiently calculate the impingement-free range of motion of irregularly-shaped total hip arthroplasty components

There is great difficulty in quickly calculating the impingement-free range of motion (IFROM) of hip components with complex shapes after total hip arthroplasty. We have established a new algorithm to investigate the effect of different shapes of hip components on the IFROM and impingement-free safe zone (IFSZ). Then find the best combination of hip prosthesis and the optimal mounting position of the elevated-rim liner under different radiographic anteversion (RA) and radiographic inclination (RI) of the cup. We found the larger the opening angle of the beveled-rim liner and the smaller the cross-sectional area of the stem neck with an inverted teardrop cross-sectional shape, the greater the IFROM of the hip component. The beveled-rim liner in combination with the stem neck with an inverted teardrop-shaped cross-section could provide the greatest IFSZ (excluding the flat-rim liner). The optimal orientation of the elevated-rim liner was the posterior-inferior side (RI ≤ 37°), posterior-superior side (RI ≥ 45°), and posterior side (37° ≤ RI ≤ 45°). Our novel algorithm provides a solution to analyze the IFROM of any hip prosthesis with any complex shape. The shape and size of the cross-section of the stem neck, the orientation of the elevated rim, and the shape and opening angle of the liner are all critical factors for the quantitative calculation of the IFROM and mounting safe zone of the prosthesis. Stem necks with inverted teardrop cross-section and beveled-rim liner improved the IFSZ. The optimal direction of the elevated rim is not constant but varies with RI and RA.

Influence of obesity and intra-operative imaging guidance technology on acetabular cup positioning in total hip arthroplasty

BACKGROUND

Accuracy of acetabular cup positioning during total hip arthroplasty (THA) can be improved with intra-operative imaging but may be influenced by body mass index (BMI). This study assessed the influence of BMI (kg/m2) on cup accuracy when using intra-operative fluoroscopy (IF) alone or supplemented with a commercial product.

METHODS

This retrospective review included four consecutive cohorts of patients having undergone anterior approach THA with IF alone (2011-2015), IF and Overlay (2015-2016) (Radlink Inc., Los Angeles, CA), IF and Grid (2017-2018) (HipGrid Drone™, OrthoGrid Systems Inc., Salt Lake City, UT) and IF and Digital (2018-2020) (OrthoGrid Phantom®, OrthoGrid Systems, Inc., Salt Lake City, UT). Component placement accuracy was measured on 6-week post-operative weight bearing radiographs and compared between four BMI patient groups (BMI ≤ 25, 25 < BMI ≤ 30, 30 < BMI ≤ 35, and 35 < BMI). Total fluoroscopy times were also recorded directly from the fluoroscopy unit.

RESULTS

Abduction angle significantly increased as BMI increased (p = 0.003) with IF alone but no difference was present in groups with guidance technology. Anteversion was significantly different between BMI groups for IF alone (p = 0.028) and Grid (p = 0.027) but was not different in Overlay (p = 0.107) or Digital (p = 0.210). Fluoroscopy time was significantly different between BMI categories for IF alone (p = 0.005) and Grid (p = 0.018) but was not different in Overlay (p = 0.444) or Digital (p = 0.170).

CONCLUSION

Morbid obesity (BMI > 35) increases risk for malpositioning of acetabular cups and increases surgical time with IF alone or the Grid. Additional IF guidance technology (Overlay or Digital) increased cup positioning accuracy without decreasing surgical efficiency.

Could We Expect Postoperative Cup Anteversion after Total Hip Arthroplasty Using Postoperative Plain Anteroposterior and Lateral Radiograph? A Three-Dimensional Experimental Operation Study

BACKGROUND

A postoperative radiograph in total hip arthroplasty (THA) is usually obtained to evaluate the inclination and anteversion of the acetabular components. However, there is no gold-standard method for calculating the exact inclination and anteversion of the acetabular components on post-THA radiographs. We aimed to measure the actual anteversion of the acetabular component on postoperative radiographs by obtaining correlation data between the virtual and actual acetabular component positioning using virtual three-dimensional (3D) surgery.

METHODS

A total of 64 hip scans of 32 patients who underwent lower-extremity computed tomography (CT) were retrospectively reviewed. We reconstructed 3D models of the 64 hips using customized computer software (Mimics). Furthermore, to identify the safe zone of acetabular component position in THA, we performed virtual 3D surgery simulations for five anteversion (-10°, 0°, 10°, 20°, and 30°) and five inclination (20°, 30°, 40°, 50°, and 60°) types. We analyzed the acetabular anatomy using 3D models to measure the radiographic, anatomical, and operative anteversion (RA, AA, OA) and inclination (RI, AI, OI) angles. Additionally, we used the Woo-Morrey (WM) method to calculate the anteversion angle in the reconstructed cross-table lateral (CL) radiographs and determined the correlation between these measurements.

RESULTS

The safe zone of the acetabular component was visualized on post-THA CL radiographs using the WM method of anteversion measurement based on the different anteversions and inclinations of the acetabular component. The AA, RA, OA, OI, and WM differed significantly between males and females (p value < 0.05). As the anatomical inclination or anteversion increased, the WM anteversion measurements also increased. The radiographic anteversion measurement best matched the WM method of measurement, followed by anatomical and operative methods.

CONCLUSIONS

The actual anteversion of the acetabular component after THA can be measured on CL radiographs with the WM method using a 3D virtual program, with good reproducibility.

Clinical utilization of methylprednisolone in conjunction with tranexamic acid for accelerated rehabilitation in total hip arthroplasty

PURPOSE

This study aimed to evaluate the efficacy and safety of combined methylprednisolone (MP) and tranexamic acid (TXA) in promoting accelerated rehabilitation following total hip arthroplasty (THA). We further investigated effective strategies for rapid rehabilitation post-THA.

METHODS

Conducted as a randomized controlled trial involving 80 patients, the study allocated subjects into two groups. The control group received saline and TXA, whereas the experimental group was administered with an additional dose of MP. Several clinical parameters, including markers of inflammation, pain, nausea, and coagulation factors, were meticulously assessed in both groups.

RESULTS

It was observed that the group receiving the MP + TXA treatment showcased significant reductions in postoperative levels of CRP and IL-6, as well as an alleviation in pain scores. Furthermore, this group demonstrated lower incidences of postoperative nausea and fatigue, facilitating enhanced hip joint mobility. Interestingly, this group did exhibit blood glucose fluctuations within the first 24 h postoperatively. However, there was no notable difference between the groups concerning transfusion rate, postoperative hospital stay duration, and coagulation profile, and no severe complications were reported.

CONCLUSION

The findings suggest that the combined administration of MP and TXA can appreciably enhance postoperative recovery, by reducing inflammatory markers, alleviating pain, reducing nausea and fatigue, and improving hip mobility, without leading to an increased risk of severe perioperative complications. This highlights the potential role of this combined therapy in facilitating improved postoperative patient experiences.

Radiographic parameters of pelvic and proximal femoral morphology do not predict outcomes for direct anterior total hip arthroplasty

BACKGROUND

Radiographic predictors of outcomes associated with direct anterior approach (DAA) total hip arthroplasty (THA) are largely unknown. Anecdotally, some surgeons limit surgery to patients with low body mass index (BMI) or "favorable" bony morphology. Objective data on the impact of these factors is limited. We sought to determine radiographic and demographic predictors of outcomes after DAA arthroplasty.

METHODS

A consecutive series of patients undergoing unilateral, elective DAA THA, who had linked pre- and post-operative patient reported outcome scores, from January 1, 2017 to March 30, 2019 were included. Radiographic measurements, including proxies for pelvic overhang, femoral canal access, acetabular morphologic changes, and markers of disease severity, were performed on calibrated radiographs. Intra-observer consistency was also evaluated. Outcome measures included disease specific and general health patient-reported outcomes scores, while surgical difficulty was approximated by estimated blood loss and surgical time. Multivariate analyses were performed to determine statistically significant correlations.

RESULTS

168 patients were included. Overall, patients experienced significant improvement in outcome scores (mean ∆ HOOS-JR 39.4, PROMIS-physical 12.3). There were two reoperations (1.2%), for recurrent dislocation. Female sex (p = 0.015) and increasing age (p == 0.019) were associated with shorter surgical times. No statistically significant correlations were found between the radiographic parameters and outcome measures. Intraclass correlation coefficients of the radiographic measurements were overall strong (0.73-1.0).

CONCLUSION

We demonstrated consistent results in this series of patients despite variation in bony morphology. Our findings suggest that DAA THA can be safely performed on a broader patient population.

Hip offset and leg-length restoration in revision hip arthroplasty with a monoblock, hydroxyapatite-coated stem

AIMS

Restoration of normal hip biomechanics in arthroplasty surgery is important in order to achieve good muscle function and joint stability.

METHODS

In this retrospective cohort study, we examined the postoperative radiographs of 131 femoral revision arthroplasty procedures using a monoblock, fully hydroxyapatite (HA)-coated titanium stem. Femoral offset, modified-global offset and leg length were measured of the operated and contralateral hips.

RESULTS

Femoral offset was restored to ±10 mm in 108 cases (82%), modified-global offset was restored ±10 mm in 93 cases (71%) and leg length was restored to ±10 mm in 102 cases (81%). There were 4 dislocations with a mean follow-up period of 38 months.

CONCLUSIONS

Restoration of hip biomechanics is achievable with a monoblock stem and thus is a viable option in revision hip arthroplasty.

Did the dislocation risk after primary total hip arthroplasty decrease over time? A meta-analysis across six decades

BACKGROUND

While continuous optimization is attempted to decrease the incidence of dislocation after total hip arthroplasty (THA), dislocation remains a major complication. This meta-analysis aims to analyze the evolution of the dislocation risk after primary THA over the decades and to evaluate its potential publication bias.

PATIENTS AND METHODS

A systematic search was performed according to the PRISMA guidelines for this meta-analysis in the literature published between 1962 and 2020. MEDLINE, Cochrane and Embase databases were searched for studies reporting the dislocation risk and length of follow-up. Studies that reported on revision rates only and did not mention separate dislocations were excluded. All study designs were eligible. Study quality was assessed by existing quality assessment tools adjusted for arthroplasty research. Overall risk and yearly dislocation rates were calculated and related to historical time frame, study design, sample size and length of follow-up.

RESULTS

In total, 174 studies were included with an overall moderate quality. In total there were 85.209 dislocations reported in 5.030.293 THAs, showing an overall dislocation risk of 1.7%, with a median follow-up of 24 months. The overall dislocation risk classified per decade decreased from 3.7% in 1960-1970 to 0.7% in 2010-2020. The yearly dislocation rate decreased from 1.8 to 0.7% within these same decades. There was no significant correlation between the reported dislocation risk and the duration of follow-up (p = 0.903) or sample size (p = 0.755). The reported dislocation risk was higher in articles with registry data compared to other study designs (p = 0.021).

CONCLUSION

The dislocation risk in THA has been decreasing over the past decades to 0.7%. Non-selective registry studies reported a higher dislocation risk compared to studies with selective cohorts and RCTs. This indicates that the actual dislocation risk is higher than often reported and 'real-world data' are reflected better in large-scale cohorts and registries.

Does total hip arthroplasty result in intercostal nerve injury? A case report and literature review

Neuropathy in surgical-related locations has received concerns after total hip arthroplasty (THA), while the contralateral intercostal nerve (ICN) injury has not been reported. A 25-year-old female patient with a body mass index (BMI) of 17.9 kg/m² visited the orthopedic outpatient clinic with complaints of progressive left hip pain for 20 days. She was diagnosed with left end-stage hip osteoarthritis and developmental dysplasia of the bilateral hips after radiographs and a detailed history-taking. After painstaking consideration, a cementless THA with the standard posterolateral approach was performed under general anesthesia. The procedure was difficult but successful. Unexpectedly, the numbness and slight tingling in the skin of the right breast, lateral chest wall, and axilla cropped up on the first postoperative day. Following the clinical features and the conclusion of the multidisciplinary discussion, we assume that ICN neuropathy is the diagnosis in this case due to compression of the lateral decubitus position during the operation. Her symptoms completely disappeared after using mecobalamin injection (0.5 mg, intramuscular injection, every other day) for 11 days. The Harris left hip score improved from 39 to 94, and the visual analogue scale from 7 was reduced to 2 on the day of discharge. There were no other complications within the first year after the operation. For THA, we should pay attention to some unexpected complications by virtue of the special position, especially in thin and low-BMI people, which suggested that further comprehensive perioperative nursing measures and the beneficial surgical position and anesthesia type were called for.

Total hip arthroplasty for failed internal fixation of femoral neck fracture: a retrospective study with 2-14 years' follow-up of 345 patients

OBJECTIVES

The purpose of this study was to analyze mid- to long-term outcomes of total hip arthroplasty (THA) following failed internal fixation of femoral neck fracture.

METHODS

This study retrospectively analyzed 345 patients with femoral neck fracture who underwent THA after failure of internal fixation at our hospital between January, 2003 and December, 2019. Patients older than 55 years (n = 175) and patients no older than 55 years (n = 170) were compared in terms of complications and survival rates during follow-up, which lasted a mean of 6 years.

RESULTS

The two age groups showed similarly low incidence of complications and similarly long periods of survival without revision surgery. Only three younger patients and two older patients underwent revision surgery during follow-up. The two groups showed similarly high survival rates at the end of follow-up (> 93%). Younger patients showed significantly bettter Harris hip score at last follow-up (90.2 vs. 88.1 points, p < 0.001) without clinically significant difference, but they required THA significantly earlier after internal fixation (4.4 vs. 6.8 years, p < 0.001).

CONCLUSIONS

THA after failed internal fixation of femoral neck fracture is a well tolerated and effective procedure in older and younger patients.

"Incidence of Instability Following Primary Total Hip Arthroplasty Continues to Decline in the Medicare Population"

BACKGROUND

Instability has been the primary cause of failure following primary total hip arthroplasty (THA) leading to revision hip surgery. The purpose of this study was to determine if instability rates have further declined following advances in primary THA including dual mobility articulations, direct anterior approaches, advanced technologies, and improved knowledge of the hip-spine relationships.

METHODS

Using the 5% Medicare Part B claims data from 1999 to 2019, we identified 81,573 patients who underwent primary THA for osteoarthritis. Patients who experienced instability at 3 months, 6 months, 1 year, and 2 years were identified. Multivariate cox regression analyses evaluated the effect of patient and procedure characteristics on the risk for instability.

RESULTS

Instability at 1 year following primary THA declined from approximately 4% in 2000 to 2.3% in 2010 and 1.6% in 2018. The leading cause of revision surgery was infection (18.6%), followed by peri-prosthetic fracture (14%), mechanical loosening (11.5%), and instability (9.4%). High risk groups for instability continue to include increased age, higher Charlson index, obesity, lumbar spine pathology, and neurocognitive disorders.

CONCLUSION

Instability is no longer the leading etiology of failure following primary THA with a decline of approximately 40% over the past decade. Infection, periprosthetic fracture, mechanical loosening, and then instability are now the leading causes of failure. Multiple factors may play a role in the decline of instability including increased use of dual mobility articulations, direct anterior approaches, improved knowledge of the hip-spine relationships, and use of advanced technologies.

Short term outcomes (average follow up of 2.4 years) of a constrained acetabular liner in primary and revision total hip arthroplasty

BACKGROUND

As instability continues to be a burden post total hip arthroplasty (THA), there has been a controversial discussion on the ideal implant choice. We report here the outcomes of a modern constrained acetabular liner (CAL) system in primary and revision THA at an average follow up of 2.4 years.

METHODS

We performed a retrospective study of all patients undergoing primary and revision hip arthroplasty and being implanted with the modern CAL system from 2013 to 2021. We identified 31 hips, of which 13 underwent primary THA and the remaining 18 underwent revision THA for instability.

RESULTS

Of those implanted with CAL primarily, 3 had concomitant abductor tear repair and gluteus maximus transfer, 5 had Parkinson's disease, 2 had inclusion body myositis, 1 had amyotrophic lateral sclerosis, and the remaining 2 were above 94 years of age. All patients implanted with the CAL were as a result of active instability post-primary THA and underwent only liner and head exchange without revision of the acetabular or femoral components. At an average follow up of 2.4 years (range, 9 months to 5 years and 4 months), we had 1 case (3.2 %) of dislocation post-CAL implantation. None of the patients undergoing surgery with CAL for active instability had a re-dislocation.

CONCLUSION

In conclusion, a constrained acetabular liner provides excellent stability in both primary THA in high risk individuals and revision THA in cases of active instability. There were no dislocations when using a constrained acetabular liner to treat active instability post THA.

Pelvic morphologies of developmental dysplasia and primary osteoarthritis on range of motion after total hip arthroplasty

Bony impingement, especially in the anterior inferior iliac spine (AIIS) after total hip arthroplasty (THA), may cause dislocation. However, the influence of AIIS characteristics on bony impingement after THA is not fully understood. Thus, we aimed to determine the morphological characteristics of AIIS with developmental dysplasia of the hip (DDH) and primary osteoarthritis (pOA) and to evaluate its effect on range of motion (ROM) after THA. Hips from 130 patients who underwent THA, including pOA were analyzed. In total, we had 27 male and 27 female participants with pOA, and 38 male and 38 female participants with DDH. The horizontal distances of AIIS from teardrop (TD) were compared. In the computed tomography simulation, flexion ROM was measured, and its relationship to the distance between TD and AIIS was investigated. DDH had a more medial (male: DDH, 36.9 ± 5.8; pOA, 45.5 ± 6.1; p < 0.001) (female: DDH, 31.5 ± 10.0; pOA, 36.2 ± 4.7; p < 0.001) position of AIIS than pOA. In the male with pOA group, flexion ROM was significantly smaller than that in the other groups, and there was a correlation between flexion ROM and horizontal distances (r = -0.543; 95% confidence interval = -0.765 to -0.206; p = 0.003). AIIS position is a factor that limits ROM during flexion after THA, particularly in males. Further studies are required to develop surgical strategies for cases of impingement at the AIIS site after THA. Level of evidence: Ш, retrospective comparative study.

Accuracy of cup placement using computed tomography-based navigation system in total hip arthroplasty through the direct anterior approach

BACKGROUND

This study aimed to elucidate the accuracy of cup placement with the computed tomography (CT)-based navigation system (CTN) in the direct anterior approach (DAA)-total hip arthroplasty (THA) in the supine position compared with the mechanical cup alignment guide (MG) or the fluoroscopy (FS).

METHODS

A total of 171 hips of 156 patients undergone primary THA were classified into the following three groups (the MG group: 63 hips, the FS group: 58 hips, the CTN group: 50 hips). Comparing the preoperative planning with postoperative CT measurement by three-dimensional templating software, the accuracy of cup placement was investigated in the three groups.

RESULTS

There were significant differences in the mean absolute error of radiographic inclination (RI) between the MG group (4.4° ± 3.2°) and the CTN group (2.8° ± 2.5°) (p = 0.01). The mean absolute error of radiographic anteversion (RA) also showed significant differences between the CTN group (2.8° ± 1.9°) and the MG group (5.8° ± 4.7°) (p = 0.0001) or the FS group (4.8° ± 4.1°) (p = 0.02). Regarding the cup center position, the mean absolute error of vertical position from preoperative planning was the smallest in the CTN group (1.8 ± 1.4 mm) compared with those in other groups (MG: 3.3 ± 3.2 mm, p = 0.007, FS: 3.2 ± 3.0 mm, p = 0.017).

CONCLUSION

The CTN guarantees accurate cup placement in the DAA-THA in the supine position compared with the MG and FS groups.

THE CEMENTED DOUBLE MOBILITY CUP IN HIP REVISION: DIFFERENT POSSIBILITIES OF USE

Introduction

The aim of our work is to review those patients who underwent prosthetic hip revision surgery in our hospital considered to be patients at high risk of dislocation or recurrent dislocation, and who underwent a double mobility cemented cup (CMD). Analyzing the different ways to place these cups and the clinical results and reluxations.

Material and methods

The 69 cases comprised 34 men and 35 women with a mean age of 77,39 years. The mean follow-up was 4.7536 years. The type of intervention performed varied according to the cause of the intervention, the acetabular bone stock and the state of the primary cup. In the cases in which there was a good fixation of the primary metalback, we opted to carry out a cementation of the cemented DMC into the existing well-fixed metal acetabular shell, this occurred in 23 cases. In the cases where there was loosening of the primary cup but there was a good bone stock, a CMD was cemented into the bone (21 cases). In the cases where there was a Paprosky type III we cemented a DMC to a Bursch-Schneider reinforcement ring together with the placement of a cancellous bone graft (25 cases).

Results

The clinical evaluation at the end of the follow-up, according to the MD Scale, showed the mean value was 16.454 (SD 0.79472), with a survival at the end of the follow-up of 100% of the placed DMC.

Conclusion

The use of cemented DMC is a good solution in the replacement of THA, especially in cases of reluxation or risk of dislocation due to personal or technical predisposing factors. The use of these DMC cemented can be directly to the bone, into the existing well-fixed metal Shell, or cemented to a reinforcing ring, depending on the acetabular defect. Evidence Level III; Comparative Case Series .

Angular changes in pelvic tilt and cup orientation at a minimum of eighteen years after primary total hip arthroplasty with an uncemented cup

BACKGROUND

Changes in pelvic tilt angle (PTA) and cup orientation have been reported in patients after total hip arthroplasty, but the current literature generally has a brief follow-up period. This study will be the first to report PTA and cup orientation changes in the supine position for a minimum 18 years after total hip arthroplasty (THA) and investigate the factors associated with pelvic tilt and cup orientation changes.

METHODS

In this study, 101 patients (120 hips) who underwent THA were retrospectively analyzed. The aims of our study were to evaluate the PTA and cup orientation change over 18 years after THA to assess differential PTA, cup inclination, and anteversion. We also investigated whether factors such as gender, body mass index, and age have any influence on PTA and cup orientation after THA.

RESULTS

Patients showed a significant incremental change in PTA pre-operatively, immediately post-operatively, and at final follow-up. Cup orientation increased significantly at the final follow-up compared to the immediate post-operative period. Gender subgroup analysis showed that PTA was significantly greater in females than in males at the final follow-up (p = 0.025). Age subgroup analysis showed that PTA was significantly greater in the over 60 years group than in the other groups.

CONCLUSION

Our patients showed significant changes in PTA and cup orientation at a minimum 18 years after surgery, especially in females over 60 years. Female patients over 60 are a risk factor after THA.

Total Hip Arthroplasty in Patients With Neurological Conditions: A Systematic Review

Background

As operative techniques and implant design have evolved over time, total hip arthroplasty (THA) is increasingly being carried out for patients with neurological impairment. This patient group places unique surgical challenges to the arthroplasty surgeon, which may include contractures, instability, and altered muscular tone. The purpose of this systematic review is to report the patient outcomes, complications, and implant survival following THA for patients with neurological conditions affecting the hip. Thus, we aim to support orthopaedic surgeon decision-making when considering and planning THA for these patients.

Methods

A systematic review was performed as per Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the PubMed/Medline OVID, Cochrane, and Embase databases. All studies reporting the outcomes of THA in the neurological population which met defined inclusion criteria were included.

Results

From an initial screen of 1820 studies, 45 studies with a total of 36,251 THAs were included in the final selection. All 45 studies reported complication rates, with controls included in 16 for comparison. High complication rates were observed following THA in the neurologically impaired population, most notably dislocation with observed rates up to 10.6%. An improvement was noted in all 36 studies (1811 THAs) which reported upon patient-reported outcomes.

Conclusions

THA may be beneficial in the selected patients with neurological conditions, to reduce pain and improve function. There is an increased risk of complications which require careful consideration when planning the operation and open discussion with prospective patients and caregivers before proceeding with surgery.

Radiologic restoration inaccuracy increases postoperative dislocation in primary total hip arthroplasty: a retrospective study with propensity score matching

BACKGROUND

Dislocation is a complicated process and associated with multivariate etiology and risk factors. The purpose of this study was to verify if radiologic restoration inaccuracy increases postoperative dislocation in primary total hip arthroplasty (THA) individually or synergistically.

METHODS

From 2017 to 2020, we identified 76 (1.9%) patients who suffered postoperative dislocations from 3926 THAs in our institution. After excluded patients with previously proven patient-related and implant-related risk factors, the remaining patients were used to match a 1:1 control patients who were without dislocation. The cup position (inclination and anteversion angles), hip offset (HO), leg length discrepancy (LLD), and abductor lever arm (ALA) were analyzed by univariate analyses and multivariate logistic regressions.

RESULTS

Measurements on radiographs showed excellent interobserver agreement (intraclass correlation coefficient (ICC) 0.922-0.952) and intraobserver agreements (ICC 0.933-0.967). HO restoration inaccuracy (without ± 5 mm) was associated with higher dislocation risk (OR 4.241 95% CI 1.440-12.492, P = 0.009). The restoration inaccuracy of the cup position, LLD, or ALA could not increase the dislocation risk individually. When combining the radiologic restoration inaccuracy factors, the HO + LLD restoration inaccuracy and HO + ALA restoration inaccuracy increased the odds of postoperative dislocation (OR 12.056, 95% CI 1.409-103.127, P = 0.023; OR 4.770, 95% CI 1.336-17.028, P = 0.016, respectively). Combining the four risk factors of cup safe zone, HO, LLD, and ALA, patients with 3 or 4 radiologic restoration inaccuracy factors showed a higher risk of dislocation (OR 13.500, 95% CI 1.340-135.983, P = 0.027).

CONCLUSION

Hip offset (HO) restoration inaccuracy increased the risk of dislocation following primary THA. Multivariate radiologic restoration accuracy is critical for the prevention of dislocation and needs to be valued by surgeons.

Prior Instability is Strongly Associated With Dislocation After Isolated Head and Liner Exchange

BACKGROUND

Isolated head and liner exchange is an appealing alternative to a more extensive revision total hip arthroplasty in patients who have well-fixed components. Despite efforts to increase femoral offset and restore soft tissue tensioning, limited component revision may be associated with higher rates of postoperative instability.

METHODS

This retrospective analysis assessed 209 patients who had a head and liner exchange conducted at a large academic medical center between 2011 and 2019 and had >2 years of follow-up. Functional cup positioning within the Lewinnek safe zone was assessed on postoperative weight-bearing radiographs. Included patients were 56% women, had a mean age of 64 years (range, 24-89) and a mean body mass index of 28.8 kg/m² (range, 18.2-46.7). The most common indications for surgery included acetabular liner wear in 86 hips (41%), instability in 40 hips (19%), and infection in 36 hips (17%).

RESULTS

Twenty-eight hips (13%) had a dislocation within 2 years after surgery. The best-fit model predicting postoperative dislocation included a history of dislocation (adjusted-odds ratio [adj-OR] 5.67, 95% CI 2.39-14.09, P < .001), age (adj-OR 1.04 per 1-year increase, 95% CI 0.99-1.08, P = .10), and body mass index (adj-OR 0.90 per 1-kg/m² increase, 95% CI 0.80-0.99, P = .046).

CONCLUSION

In a large cohort of patients who had isolated head and liner exchange, patients who had prior instability had 7-fold elevated odds of postoperative dislocation. This risk remains significant after controlling for cup positioning outside the Lewinnek safe zone, liner type, head size, neck length, soft tissue compromise, neuromuscular disease, and dual mobility constructs.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Robotic-Arm-Assisted Total Hip Arthroplasty: A Review of the Workflow, Outcomes and Its Role in Addressing the Challenge of Spinopelvic Imbalance

Robotic-arm-assisted total hip arthroplasty (RoTHA) offers the opportunity to improve the implant positioning and restoration of native hip mechanics. The concept of individualised, functional implant positioning and how it relates to spinopelvic imbalance is an important yet rather novel consideration in THA. There is mounting evidence that a significant percentage of dislocations occur within the perceived “safe zones”; hence, in the challenging subset of patients with a stiff spinopelvic construct, it is imperative to employ individualised component positioning based on the patients’ phenotype. Restoring the native centre of rotation, preserving offset, achieving the desired combined anteversion and avoiding leg length inequality are all very important surgeon-controlled variables that have been shown to be associated with postoperative outcomes. The latest version of the software has a feature of virtual range of motion (VROM), which preoperatively identifies potential dynamic causes of impingement that can cause instability. This review presents the workflow of RoTHA, especially focusing on pragmatic solutions to tackle the challenge of spinopelvic imbalance. Furthermore, it presents an overview of the existing evidence concerning RoTHA and touches upon future direction.

Patient-specific Hip Arthroplasty Dislocation Risk Calculator: An Explainable Multimodal Machine Learning-based Approach

PURPOSE

To develop a multimodal machine learning-based pipeline to predict patient-specific risk of dislocation following primary total hip arthroplasty (THA).

MATERIALS AND METHODS

This study retrospectively evaluated 17 073 patients who underwent primary THA between 1998 and 2018. A test set of 1718 patients was held out. A hybrid network of EfficientNet-B4 and Swin-B transformer was developed to classify patients according to 5-year dislocation outcomes from preoperative anteroposterior pelvic radiographs and clinical characteristics (demographics, comorbidities, and surgical characteristics). The most informative imaging features, extracted by the mentioned model, were selected and concatenated with clinical features. A collection of these features was then used to train a multimodal survival XGBoost model to predict the individualized hazard of dislocation within 5 years. C index was used to evaluate the multimodal survival model on the test set and compare it with another clinical-only model trained only on clinical data. Shapley additive explanation values were used for model explanation.

RESULTS

The study sample had a median age of 65 years (IQR: 18 years; 52.1% [8889] women) with a 5-year dislocation incidence of 2%. On the holdout test set, the clinical-only model achieved a C index of 0.64 (95% CI: 0.60, 0.68). The addition of imaging features boosted multimodal model performance to a C index of 0.74 (95% CI: 0.69, 0.78; P = .02).

CONCLUSION

Due to its discrimination ability and explainability, this risk calculator can be a potential powerful dislocation risk stratification and THA planning tool.Keywords: Conventional Radiography, Surgery, Skeletal-Appendicular, Hip, Outcomes Analysis, Supervised Learning, Convolutional Neural Network (CNN), Gradient Boosting Machines (GBM) Supplemental material is available for this article. © RSNA, 2022.

Long-Term Survivorship of Cemented and Uncemented Polyethylene Liner Exchange

BACKGROUND

Revision surgery is usually required for complications associated with total hip arthroplasty (THA). Significant morbidity can be associated with revision THA and thus some may only revise the liner of the original metal back component if it is found to be well fixed. We compare the long-term survivorship of cemented and uncemented head-liner THA exchange surgeries and possible causes.

METHODS

Between 2000 and 2018, we reviewed cases from our arthroplasty database who underwent THA revision for head-liner exchange. We stratified our cohort into 2 groups: cemented and uncemented liners. Patients were followed clinically and radiographically to determine survivorship of the exchanges for both cemented and uncemented liners. Implant survivorship was measured using a competing risk analysis considering death and patients lost to follow-up as competing risks.

RESULTS

A total of 84 patients (85 hips) underwent head-liner exchange surgery during the study period (21 cemented and 64 uncemented liners). The mean follow-up time was 6.9 years, with 75.3% and 24.7% of patients having been revised due to non-dislocation and dislocation causes, respectively. Two cemented liners (9.5%) and 11 uncemented liners (17.2%) required revision. The survival analysis of all head-liner revision was 86.4% at 18 years. Survival estimates liner exchanges due to dislocation versus non-dislocation groups were 57.3% versus 82.7% respectively (P = .034).

CONCLUSION

The present study shows improved survivorship of head-liner exchanges performed due to non-dislocation etiology compared to dislocation etiology, but no difference in survivorship between cemented and uncemented head-liner exchange.

LEVEL OF EVIDENCE

Level III.

Application of dexamethasone combined with tranexamic acid in perioperative period of total hip arthroplasty

OBJECTIVE

To evaluate the efficacy and safety of dexamethasone (DEXA) combined with tranexamic acid (TXA) in the perioperative period of total hip arthroplasty.

MATERIALS AND METHODS

A total of 100 cases were randomly divided into 2 groups (50 cases per group). All patients were given 15 mg/kg TXA before skin incision and 3 hours later. Patients in the intervention group (TXA + DEXA group) were given 20 mg dexamethasone intravenously after the onset of anesthesia, and the same dose of DEXA was administered again 24 hours later. Patients in the placebo group (TXA group) were only given the same dose of normal saline. Postoperative c-reactive protein and interleukin-6, postoperative nausea and vomiting, fatigue visual analogue scale score, postoperative length of stay, range of motion, and consumption of analgesic and antiemetics were statistically analyzed in the 2 groups.

RESULTS

The levels of c-reactive protein and interleukin-6 in the TXA + DEXA group were lower than those in the TXA group at 24, 48, 72 hours post-operatively (P < .001). Walking pain scores in the TXA + DEXA group were also significantly lower than those in the TXA group at 24 and 48 hours (P < .001); rest pain scores were lower at 24 hours (P < .001). Compared with the TXA group, the incidence of nausea VAS, postoperative nausea and vomiting, fatigue, analgesia and antiemetics consumption, postoperative length of stay, and range of motion were lower in the TXA + DEXA group (all P < .05), while there were no significant differences in postoperative hematocrit, total blood loss, and complications (P > .05).

CONCLUSION

The combination of TXA (15 mg/kg; before skin incision and 3 hours later) and DEX (20 mg dexamethasone intravenously after the onset of anesthesia, and again 24 hours later) is an effective and safe strategy for patients undergoing total hip arthroplasty.

Clinical efficacy of direct anterior approach vs. other surgical approaches for total hip arthroplasty: A systematic review and meta-analysis based on RCTs

BACKGROUND

Direct anterior approach (DAA) is an accurate technique for total hip arthroplasty (THA) through the muscle gap. Physicians who apply DAA believe that it accelerates patient recovery and results in lower rates of postoperative dislocation. However, the traditional surgical approach adherents believe that it is shorter and has fewer complications than DAA.

METHODS

We use the method of META analysis to organize and analyze the data of the randomized controlled studies (RCT) obtained after our screening. To compare the clinical efficacy of DAA approach and other surgical approaches for THA.

RESULTS

After rigorous screening, 15 RCT studies were included in our study, and data were extracted. The study included 1,450 patients from 15 RCTs, with a mean age of 63 years and a distribution of 52-67 years. Six weeks after the operation, the Harris hip score of the DAA approach improved by an average of 4.06 points (95% confidence interval (CI) 2.54 -5.59, P < 0.01, I ² = 45%, which can significantly improve the clinical efficacy of patients. However, the 0.61 points [95% confidence interval (CI) -1.13 -2.34, P > 0.01, I ²= 0%] at 3 months and 1.49 points [95% confidence interval (CI) -1.65 -2.25, P > 0.01, I ²= 0%] at 12 months postoperatively. In terms of dislocation rate, results show that the use of DAAs does not reduce Dislocation Rate with significant statistical heterogeneity among study groups (95% CI 0.18-2.94 P > 0.001, I ²= 0%).

CONCLUSION

The hip function of DAA was superior to posterolateral approach (PLA) and latera approach (LA) in the early days after hip replacement, especially within six weeks. However, at six months or more after surgery, the difference was not significant. The DAA did not show a lower rate of dislocation than other surgical approaches.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO.

Risk factor investigation for hip dislocation after periacetabular tumour resection and endoprosthetic reconstruction via thin-slice CT-based 3D model

AIMS

Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation.

METHODS

A total of 122 patients who underwent reconstruction following resection of periacetabular tumour between January 2011 and January 2020 were studied. The risk factors for dislocation were investigated with univariate and multivariate logistic regression analysis on patient-specific, resection-specific, and reconstruction-specific variables.

RESULTS

The dislocation rate was 13.9% (n = 17). The hip COR was found to be significantly shifted anteriorly and inferiorly in most patients in the dislocation group compared with the non-dislocation group. Three independent risk factors were found to be related to dislocation: resection of gluteus medius (odds ratio (OR) 3.68 (95% confidence interval (CI) 1.24 to 19.70); p = 0.039), vertical shift of COR > 18 mm (OR 24.8 (95% CI 6.23 to 128.00); p = 0.001), and sagittal shift of COR > 20 mm (OR 6.22 (95% CI 1.33 to 32.2); p = 0.026).

CONCLUSION

Among the 17 patients who dislocated, 70.3% (n = 12) were anterior dislocations. Three independent risk factors were identified, suggesting the importance of proper restoration of the COR and the role of the gluteus medius in maintaining hip joint stability.Cite this article: Bone Joint J 2022;104-B(10):1180-1188.

The incidence of hip dislocation after posterior approach primary total hip arthroplasty: comparison of two different posterior repair techniques

INTRODUCTION

Total hip arthroplasty (THA) remains one of the most successful orthopedic surgical procedures. The posterior approach is associated with a higher incidence of post-operative dislocations than others. Adequate posterior soft tissue repair techniques, including capsulorrhaphy and transosseous bone sutures in the greater trochanter effectively reduce the dislocation rate. Post-operative "posterior hip precautions" were historically believed to reduce dislocation risks, although not clearly proven. The first protocol consists of capsulorrhaphy with the prescription of post-operative posterior hip precautions (TT) and the second, transosseous bone sutures without precautions (TB). This study aims to determine the optimal protocol to decrease the dislocation rate following posterior approach primary THA.

MATERIALS AND METHODS

A 10-year retrospective case-control chart review analyzed demographic, pre-, intra-, and post-surgical parameters. Primary outcomes were the difference in dislocation and revision surgery rates between protocols. Secondary outcomes included the incidence of recurrent dislocations and the identification of predictors of dislocation.

RESULTS

2,242 THAs were reviewed and 26 (1.2%) resulted in dislocation. Increased age (p = 0.04) ASA score (p = 0.03) and larger acetabular cup size (p < 0.001) were associated with heightened risk. Tendon to tendon (TT) repair saw a 1.62% dislocation rate versus 0.98% for tendon-to-bone (TB) repair, although statistically insignificant (p = 0.2). Transosseous repair resulted in recurrent dislocations for 8/16 (50%) patients compared to 6/10 (60%) in the suture group (p ≤ 0.001). No significance was found for prescription of posterior hip precautions.

CONCLUSIONS

To our knowledge, this is the first study to perform a direct comparison of TT repair with posterior precautions to TB repair without posterior precautions. Similarity in dislocation rate, decreased recurrent events and the alleviated patient burden from precautions leads the authors to recommend the TB repair without precautions for a successful THA.

Case report: A 3-year follow-up study of simultaneous bilateral total hip arthroplasty for Femoral head necrosis in a patient with Kashin-Beck Disease

Introduction

Kashin-Beck Disease (KBD) is an endemic disease predominantly affecting joint and skeletal muscle, predisposing the articular cartilage to degeneration and necrosis. Currently,staged total hip arthroplasty is a common surgical method for advanced femoral head necrosis from KBD, but there are no reports in the literature on simultaneous bilateral total hip arthroplasty (SB-THA) for patients with KBD.

Case presentation

A 42-year-old male from Shaanxi Province, an endemic area, had bilateral hip pain for 4 years, with hips inversion and a crossed gait. After preoperative preparation, a SB-THA was performed by a posterolateral approach. Postoperative medication and functional exercises were administered and the patient was followed up for at least 3 years after discharge. The patient's hip mobility, hip scores and quality of life scores were recorded in detail during the follow-up.

Result

The patient stopped antibiotic treatment on the postoperative day-2, and all inflammatory indicators showed normal and started appropriate exercise, and the pain score decreased significantly. On the postoperative day-7, the patient had gradually adapted to various forms of rehabilitation exercises. He was discharged from the hospital on the postoperative day-10 and continued to be followed up. From the preoperative period to the last follow-up, the patient's bilateral hip mobility and functional scores improved significantly, and no adverse events such as hip pain, prosthesis loosening or dislocation were found at the last follow-up.

Conclusion

The patient's performance was satisfactory both intraoperatively and in the early postoperative period, but the hip scores and quality of life scores began to plateau or even decline from the third year after surgery to the last follow-up, probably due to the influence of further damage to articular cartilage in other parts of the body.