Recurrent Hip Dislocation Following Total Hip Arthroplasty: Treatment with Sagittal Spinal Deformity Correction: A Case Report

Self-Reducible Painless and Recurrent Prosthetic Hip Dislocation: A Case Study

Prosthetic hip dislocations following total hip arthroplasty can significantly impact patient quality of life and functional capabilities. Early dislocations typically occur within the first three months post-surgery, while delayed dislocations arise after three months. Notably, patients may experience implant instability and dislocation for years, even decades, after the initial procedure due to a variety of underlying issues. A comprehensive evaluation including patient history, physical examination, and imaging studies is essential for diagnosing delayed dislocations. Reducing prosthetic hip dislocations can be particularly challenging, often necessitating the cooperation of multiple healthcare professionals to perform a series of reduction maneuvers. For this reason, it is surprising when an individual is able to self-reduce a dislocated prosthetic hip. Documenting this instance of self-reduction can foster dialogue among orthopedic surgeons and healthcare providers, ultimately enhancing the management strategies for similar cases in the future. In this study, the case of a 73-year-old male with a six-month history of painless, recurrent prosthetic hip dislocations with self-reduction is detailed. Self-reduction was performed via maneuvers including right lower extremity extension and external rotation. To corroborate the patient's story, multiple X-rays were obtained. These images demonstrated an initially stable right hip prosthesis, followed by evidence of a dislocated femoral implant, and concluded with a reduced hip after self-reduction.  Self-reduction of a prosthetic hip dislocation by a patient is unusual, therefore presenting a unique case. The primary purpose of this case report is to describe this case of self-reduction, increase awareness of this instance, and highlight the importance of obtaining serial imaging to thoroughly identify a potential dislocation.

How the hip-spine relationship influences total hip arthroplasty

INTRODUCTION

Motion in the spine, pelvis and hips which make up the spinopelvic femoral complex (SPFC) implies mechanical relationships that help maintain trunk balance and optimize hip functionThe aim of this study was to understand the physiology of the SPFC and evaluate the dysfunctions of the SPFC and their implications for total hip arthroplasty considering the hip-spine relationship.

METHODS

A review of relevant and comprehensive studies on this subject is reported in order to highlight a pathophysiology that integrates the description of the evaluations of the spine-pelvic and hip parameters and recommendations for the kinematic planning of the THA procedure. The primary objective was to determine which type of hip-spine relationship has the highest risk for THA complications and to become proficient in selecting the priority surgical intervention when both the hip and spine are affected. Finally, this review attempted to assist hip surgeons with surgical technique, tools, implant selection, and goals of planning a THA that requires personalized kinematic alignment. Determine the influence of THA on these kinematics and the effect of stiffness of the lumbopelvic complex on the risk of THA failure.

RESULTS

When a person sits, the pelvis goes into retroversion and the acetabulum opens forward. This frees the femoral head and neck to allow hip flexion. The opposite - pelvic anteversion - occurs when a person stands. When pelvic mobility is limited, the hip must increase its range of motion to accommodate these posture changes. Disturbances in spinal and pelvic kinematics lead to abnormal hip function, which may contribute to complications following total hip arthroplasty (THA).

CONCLUSION

A precise evaluation of the parameters governing the SPFC must be taken into account in order to best optimize the placement and choice of THA implants.

LEVEL OF EVIDENCE

IV.

Spinopelvic Biomechanics and Total Hip Arthroplasty: A Primer for Clinical Practice

Abnormal spinopelvic motion from spine pathology is associated with inferior outcomes after total hip arthroplasty, including inferior patient-reported outcomes, increased rates of instability, and higher revision rates. Identifying these high-risk patients preoperatively is important to conduct the appropriate workup and formulate a surgical plan. Standing and sitting lateral spinopelvic radiographs are able to identify and quantify abnormal spinopelvic motion. Depending on the type of spinopelvic deformity, some patients may require increased anteversion, increased offset, and large diameter heads or dual mobility articulations to prevent dislocation. This review article will provide the reader with practical information that can be applied to patients regarding the terminology, pathophysiology, evaluation, and management of total hip arthroplasty patients with spinopelvic pathology.

The Impact of Spinopelvic Mobility on Arthroplasty: Implications for Hip and Spine Surgeons

Spinopelvic mobility represents the complex interaction of hip, pelvis, and spine. Understanding this interaction is relevant for both arthroplasty and spine surgeons, as a predicted increasing number of patients will suffer from hip and spinal pathologies simultaneously. We conducted a comprehensive literature review, defined the nomenclature, summarized the various classifications of spinopelvic mobility, and outlined the corresponding treatment algorithms. In addition, we developed a step-by-step workup for spinopelvic mobility and total hip arthroplasty (THA). Normal spinopelvic mobility changes from standing to sitting; the hip flexes, and the posterior pelvic tilt increases with a concomitant increase in acetabular anteversion and decreasing lumbar lordosis. Most classifications are based on a division of spinopelvic mobility based on ΔSS (sacral slope) into stiff, normal, and hypermobile, and a categorization of the sagittal spinal balance regarding pelvic incidence (PI) and lumbar lordosis (LL) mismatch (PI–LL = ± 10° balanced versus PI–LL > 10° unbalanced) and corresponding adjustment of the acetabular component implantation. When performing THA, patients with suspected pathologic spinopelvic mobility should be identified by medical history and examination, and a radiological evaluation (a.p. pelvis standing and lateral femur to L1 or C7 (if EOS (EOS imaging, Paris, France) is available), respectively, for standing and sitting radiographs) of spinopelvic parameters should be conducted in order to classify the patient and determine the appropriate treatment strategy. Spine surgeons, before planned spinal fusion in the presence of osteoarthritis of the hip, should consider a hip flexion contracture and inform the patient of an increased risk of complications with existing or planned THA.

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.

In Vivo analysis of spinopelvic kinematics and peak head-cup contact in total hip arthroplasty patients with lumbar degenerative disc disease

Anterior instability after total hip arthroplasty (THA) has been described in patients with thoracolumbar kyphotic deformity. Although compensatory posterior pelvic tilt with subsequent increased functional anteversion has been described as the mechanism, there is a paucity of in vivo data. The purpose of our study was to compare pelvic tilt, anteversion, inclination, and position of head-cup contact points in patients with lumbar degenerative disc disease (DDD) and a matched patient cohort without DDD. A total of 50 THA, 18 hips with lumbar DDD and 32 hips without DDD, underwent CT imaging for 3D hip reconstruction. Component orientations and in vivo hip gait kinematics was quantified using a validated dual fluoroscopic imaging system. Hip kinematics and head-cup contact points were compared. Patients with lumbar DDD demonstrated decreased maximum (5.9° ± 4.2° vs. 9.3° ± 5.4°, p = 0.02) and minimum (2.4° ± 4.1° vs. 6.2° ± 5.6°, p = 0.01) anterior pelvic tilt, and increased maximum cup anteversion (29.3° ± 8.7° vs. 25.1° ± 8.1°, p = 0.05). The peak head-cup contact points were shifted closer to the anterior edge of the polyethylene (7.8 ± 1.7 mm vs. 9.6 ± 2.2 mm, p = 0.02). Patients with lumbar degenerative disc disease demonstrated increased posterior pelvic tilt, functional acetabular anteversion, inclination as well as shifting of the peak head-cup contact pattern significantly closer to an anterior edge, suggesting sagittal spinopelvic deformity may predispose to anterior instability in THA patients during upright activities. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Late Dislocation Following Total Hip Arthroplasty: Spinopelvic Imbalance as a Causative Factor

BACKGROUND

Late dislocations after total hip arthroplasty (THA) are challenging for the hip surgeon because the cause is often not evident and recurrence is common. Recently, decreased spinopelvic motion has been implicated as a cause of dislocation. The purpose of this study was to assess the mechanical causes of late dislocation, including the influence of spinopelvic motion.

METHODS

Twenty consecutive patients were studied to identify the cause of their late dislocation. Cup inclination and anteversion were measured on standard pelvic radiographs. Lateral standing and sitting spine-pelvis-hip radiographs were used to measure pelvic motion, femoral mobility, and sagittal cup position by assessing sacral slope, pelvic-femoral angle, and cup ante-inclination. Spinopelvic motion was defined as the difference between the standing and sitting sacral slopes (Δsacral slope). A new measurement, the combined sagittal index, which measures the sagittal acetabular and femoral positions, was used to assess the functional motion of the hip joint and risk of impingement.

RESULTS

There were 9 anterior dislocations (45%) and 11 posterior dislocations (55%) at a mean of 8.3 years after a primary THA. Eight of the 9 patients with an anterior dislocation had spinopelvic abnormalities such as fixed posterior pelvic tilt when standing, increased standing femoral extension, and an increased standing combined sagittal index. Ten of the 11 patients with a posterior dislocation had abnormal spinopelvic measurements such as decreased spinopelvic motion (average Δsacral slope [and standard error] = 9.0° ± 2.4°), increased femoral flexion, and a decreased sitting combined sagittal index. For every 1° decrease in spinopelvic motion, there was an associated 0.9° increase in femoral motion and, in some patients, this resulted in osseous impingement and dislocation.

CONCLUSIONS

Patients with a late dislocation have abnormal spinopelvic motion that precipitates the dislocation, especially when combined with cup malposition or soft-tissue abnormalities. Spinopelvic stiffness is associated with increased age and increased femoral motion, which may lead to impingement and dislocation. Lateral spine-pelvis-hip radiographs may predict the risk and direction of dislocation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.