Investigation of the Unstable Total Hip Arthroplasty

Patients Requiring Both Total Hip Arthroplasty and Lumbar Spinal Fusion Have Lower Hip Functional Outcome Scores: A Matched Case-Control Study

BACKGROUND

While patients who undergo both lumbar spinal fusion (LSF) and total hip arthroplasty (THA) have increased complication rates compared to patients who have not undergone LSF, there is a paucity of literature evaluating THA functional outcomes in patients with a history of LSF. This study was conducted to determine whether patients undergoing THA with a history of LSF have inferior functional outcomes compared to patients having no history of LSF.

METHODS

A retrospective matched case-control study was conducted at an academic center. Patients who underwent both THA and LSF (cases) were matched with controls who underwent THA without LSF. Inclusion criteria required a minimum of 1-year follow-up for the Hip Disability and Osteoarthritis Outcome Score Joint Replacement [HOOS-JR]. Following propensity matching for age, sex, race, body mass index, and comorbidities, 291 cases and 1,164 controls were included, with no demographic differences.

RESULTS

Patients who underwent both THA and LSF had a significantly lower preoperative HOOS-JR (47 versus 50; P < .001), postoperative HOOS-JR (77 versus 85; P < .001), a significant lower rate of achieving the patient acceptable symptom state (55 versus 67%; P < .001), with no significant difference in delta HOOS-JR (34 versus 34; P = .834). When comparing patients undergoing THA before LSF or LSF before THA, no differences existed for preoperative HOOS-JR (50 versus 47; P = .304), but patients undergoing THA before LSF had lower postoperative HOOS-JR scores (74 versus 81; P = .034), a lower-delta HOOS-JR (27 versus 35; P = .022), and a lower rate of reaching the HOOS-JR minimal clinically important difference (62 versus 76%; P = .031).

CONCLUSIONS

Patients who have a history of LSF experience a similar improvement in hip function when undergoing THA compared to patients who do not have a history of LSF. However, due to lower preoperative function, they may have a lower postoperative functional outcome ceiling. Additionally, patients undergoing THA before LSF have worse hip functional outcomes than patients undergoing LSF before THA.

Increased dislocation rates following total hip arthroplasty in patients with ankylosing spondylitis

BACKGROUND

Patients with ankylosing spondylitis (AS) experience abnormal spinopelvic motion due to chronic inflammation of the axial skeleton, predisposing them to impingement and dislocation. The purpose of this study was to evaluate total hip arthroplasty (THA) dislocation rates in AS patients and evaluate the effects of age and gender on dislocation risk.

METHODS

Patients who underwent primary THA from 2005 to 2014 were identified using the PearlDiver database. AS patients were compared to age- and gender-matched controls without AS. Patients with a history of spine pathology or spine surgery were excluded. Univariate analyses were performed based on age and sex to evaluate dislocation rates at 90 days, 6 months, 1 year, and 5 years postoperatively.

RESULTS

A total of 2792 THA patients (59.6% male) with AS were identified and compared to an age- and gender-matched control group of 5582 THA patients (59.5% male) without AS or known spine pathology. At final follow-up, there were 96 dislocations (3.4%) in the AS group and 138 (2.5%) dislocations in the control group (OR 1.40; 95% CI, 1.08-1.83; p = 0.0118). AS patients ⩾70 years old had higher dislocation rates at all time points (OR range, 1.75-2.09; p < 0.05) compared to controls. At 5-year follow-up, dislocation-free survivorship was 95.7% (95% CI, 94.5-96.9%) for AS patients ⩾70 years old compared to 97.3% (95% CI, 96.6-98.0%) for patients ⩾70 years old without AS.

CONCLUSIONS

Older AS patients have higher dislocation rates following THA. This effect is likely related to decreased spinopelvic motion in the sagittal plane, predisposing patients to impinge and dislocate.

A Novel Method to Calculate Functional Pelvic Tilt Using a Standing Anteroposterior Pelvis Radiograph

Background

Functional patient-specific acetabular component positioning is important in total hip arthroplasty. We preoperatively evaluate the pelvic tilt (PT) on standing anteroposterior (AP) pelvis radiographs using a novel measurement and then recreate this intraoperatively using imaging. The purpose of this study was to determine if there is a linear correlation between this novel measurement and the actual PT.

Methods

A retrospective study of 200 patients was performed, measuring PT on standing lateral radiographs as the angle between the anterior superior iliac spines and the pubic symphysis. On the AP pelvis radiographs, the trans-teardrop (TT) line was drawn between the teardrops. The vertical distance between the TT line and the top of the pubic symphysis (TTPS) was then measured. A ratio was made between the lengths of both lines to account for the overall size of the pelvis (TTPS/TT). Linear regression analysis was then performed between PT and TTPS/TT.

Results

There was a strong linear correlation between the TTPS/TT ratio on AP pelvis radiographs and PT on lateral radiographs (r = 0.785, r² = 0.616, P < .001). On subanalysis of the female cohort, the correlation became even stronger (r = 0.864, r² = 0.747, P < .001). Using regression analysis, a linear equation was created (PT = 97.32 [TTPS/TT] - 5.51), to calculate the PT using the TTPS/TT ratio.

Conclusions

There is a strong linear correlation between the TTPS/TT ratio and PT. Using this information, a surgeon can reliably use the distance between the TT line and the superior pubic symphysis on an AP radiograph to recreate the patient's functional PT intraoperatively, allowing for a more accurate patient-specific placement of the acetabular component.

Evaluating Outcomes of Spinopelvic Fixation for Patients Undergoing Long Segment Thoracolumbar Fusion with a Prior Total Hip Arthroplasty

INTRODUCTION

Understanding the relationship between spinal fusion and its effects on relative spinopelvic alignment in patients with prior total hip arthroplasty (THA) is critical. However, limited data exist on the effects of long spinal fusions on hip alignment in patients with a prior THA. Our objective was to compare clinical outcomes and changes in hip alignment between patients undergoing long fusion to the sacrum versus to the pelvis in the setting of prior THA.

METHODS

Patients with a prior THA who underwent elective thoracolumbar spinal fusion starting at L2 or above were retrospectively identified. Patients were placed into one of two groups: fusion to the sacrum or pelvis. Preoperative, six-month postoperative, one-year postoperative, and delta spinopelvic and acetabular measurements were measured from standing lumbar radiographs.

RESULTS

A total of 112 patients (55 sacral fusions, 57 pelvic fusions) were included. Patients who underwent fusion to the pelvis experienced longer length of stay (LOS) (8.31 vs. 4.21, P < 0.001) and less frequent home discharges (30.8% vs. 61.9%, P = 0.010), but fewer spinal revisions (12.3% vs. 30.9%, P = 0.030). No difference was observed in hip dislocation rates (3.51% vs. 1.82%, P = 1.000) or hip revisions (5.26% vs. 3.64%, P = 1.000) based on fusion construct. Fusion to the sacrum alone was an independent predictor of an increased spine revision rate (odds ratio: 3.56, P = 0.023). Patients in the pelvic fusion group had lower baseline lumbar lordosis (LL) (29.2 vs. 42.9, P < 0.001), six-month postoperative LL (38.7 vs. 47.3, P = 0.038), and greater 1-year ∆ pelvic incidence-lumbar lordosis (-7.98 vs. 0.21, P = 0.032).

CONCLUSION

Patients with prior THA undergoing long fusion to the pelvis experienced longer LOS, more surgical complications, and lower rate of spinal revisions. Patients with instrumentation to the pelvis had lower LL preoperatively with greater changes in LL and pelvic incidence-lumbar lordosis postoperatively. No differences were observed in acetabular positioning, hip dislocations, or THA revision rates between groups.

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.

Imaging in Hip Arthroplasty Management-Part 1: Templating: Past, Present and Future

Hip arthroplasty is a frequently used procedure with high success rates. Its main indications are primary or secondary advanced osteoarthritis, due to acute fracture, osteonecrosis of the femoral head, and hip dysplasia. The goals of HA are to reduce pain and restore normal hip biomechanics, allowing a return to the patient’s normal activities. To reach those goals, the size of implants must suit, and their positioning must meet, quality criteria, which can be determined by preoperative imaging. Moreover, mechanical complications can be influenced by implant size and position, and could be avoided by precise preoperative templating. Templating used to rely on standard radiographs, but recently the use of EOS^® imaging and CT has been growing, given the 3D approach provided by these methods. However, there is no consensus on the optimal imaging work-up, which may have an impact on the outcomes of the procedure. This article reviews the current principles of templating, the various imaging techniques used for it, as well as their advantages and drawbacks, and their expected results.

Imaging in Hip Arthroplasty Management Part 2: Postoperative Diagnostic Imaging Strategy

Hip arthroplasty (HA) is a frequently used procedure with high success rates, but 7% to 27% of the patients complain of persistent postsurgical pain 1 to 4 years post-operation. HA complications depend on the post-operative delay, the type of material used, the patient’s characteristics, and the surgical approach. Radiographs are still the first imaging modality used for routine follow-up, in asymptomatic and painful cases. CT and MRI used to suffer from metallic artifacts but are nowadays central in HA complications diagnosis, both having their advantages and drawbacks. Additionally, there is no consensus on the optimal imaging workup for HA complication diagnosis, which may have an impact on patient management. After a brief reminder about the different types of prostheses, this article reviews their normal and pathologic appearance, according to each imaging modality, keeping in mind that few abnormalities might be present, not anyone requiring treatment, depending on the clinical scenario. A diagnostic imaging workup is also discussed, to aid the therapist in his imaging studies prescription and the radiologist in their practical aspects.

Instability After Primary Total Hip Arthroplasty: Dual Mobility Versus Jumbo Femoral Heads

BACKGROUND

The use of dual mobility (DM) articulations has grown substantially over the last decade to help minimize dislocation risk. The purpose of this study is to compare the results of DM articulations to jumbo femoral heads of equivalent sizes as they relate to postoperative dislocation.

METHODS

This is a retrospective cohort study of primary total hip arthroplasties (THAs) performed at a single institution between 2005 and 2018. DM articulations and large-diameter metal-on-metal femoral heads were included. Patients were followed with Harris Hip Scores and standard radiographs. Complications were prospectively recorded. Statistical analyses included chi-squared and Brown-Forsythe tests.

RESULTS

In total, 1,288 Magnum femoral head THAs and 365 Active Articulation DM THAs were included for analysis. The same monoblock cup was implanted via a posterior approach in all cases. Age, gender, body mass index, and diagnosis were similar between groups. Average follow-up in the DM group was 49 months, and 126 months in the jumbo head group. The average head sizes in the DM and jumbo head groups were 50 mm. There were no dislocations in the DM hips and only 2 (0.2%) in the jumbo femoral head group. Both groups had significant improvements in Harris Hip Score from their preoperative baseline.

CONCLUSION

Our study found similarly low dislocation rates in DM and jumbo femoral heads in primary THA. No evidence currently exists showing a benefit of the DM articulation beyond that of the large effective head size, and we recommend making every attempt at maximizing head size prior to using DM articulations.

Causes of and treatment options for dislocation following total hip arthroplasty

The second most common complication following total hip arthroplasty (THA) is dislocation. The majority of dislocations occur early in the post-operative period and are due to either patient-associated or surgical factors. The patient-associated factors that have been implicated as causes of post-operative dislocation include previous surgery, lumbar spine fusion surgery and/or neurological impairment. The surgical factors include surgical approach, component orientation and prosthetic and/or bony impingement. In order to delineate the cause of the hip instability a thorough history and physical and a radiographic assessment (possibly including advanced imaging) needs to be performed. Approximately two thirds of cases are successfully treated; one third of cases will require surgical treatment (e.g., revision arthroplasty (including constrained liners, the use of elevated rim liners and dual mobility implants or trochanteric advancement). In this review, we discuss the causes leading to dislocation following THA and evaluate the different treatment options available.

[Revision total hip arthroplasty : Significance of instability, impingement, offset and gluteal insufficiency]

BACKGROUND

Instability is a common cause of failure in primary and, especially, revision total hip arthroplasty. The reasons for instability include implant malpositioning, impingement, inadequate offset reconstruction, and gluteal insufficiency. Impingement following THA and revision THA is divided into prosthetic and bony impingement, and in addition to instability also causes pain in the area of the hip joint. Offset reconstruction during revision THA is of particular biomechanical importance, since insufficient reconstruction leads not only to instability and pain but also to dislocation. Abductor deficiency often occurs after revision THA and leads to a change in gait pattern, instability and pain.

AIM

Current diagnostic and treatment procedures for instability, impingement, insufficient offset reconstruction and abductor deficiency after THA and revision THA are summarized.

RESULTS AND DISCUSSION

Diagnosis of an instable THA and painful THA includes patient history, physical examination and medical imaging. Thus, in almost all cases, the cause can be determined and treated. Dislocation after primary THA in the early postoperative period can often be treated conservatively if accurate component placement is observed, while a late-onset and recurrent dislocation after primary and revision THA usually needs surgical procedures. To avoid bony and prosthetic THA impingement intraoperative control is absolutely necessary. If possible, the offset reconstruction is based on the condition of the native hip joint and can be achieved by using modular prostheses, neck adapters and different head lengths. Abductor deficiency also occurs frequently after revision THA and can be treated surgically if severe clinical symptoms and fatty degeneration of the abductors have been diagnosed.