Ipsilateral above-knee amputation in patient with recurrent dislocation after total hip arthroplasty: A case report.

Amputation secondary to vascular complications of recurrent dislocations after total hip arthroplasty (THA) is an extremely rare. We describe an unusual case of above-knee amputation resulting from vascular complications after recurrent dislocations of a THA. A 63-year-old male patient with walking pain and limp has a history of acetabular fracture and central dislocation of the femoral head. He was diagnosed as post-traumatic arthritis and subluxation of the femoral head and suffered from four similar dislocations in 210 days after the THA. The patient received conservative treatment after every hip dislocation. However, four months after the fourth reduction, the emergent femoral artery and popliteal artery exploration and catheter thrombectomy were performed at another hospital. An ipsilateral above-knee amputation was done after sepsis and failure of the revascularization procedure. Clinicians should be cognizant that above-knee amputation resulting from vascular complications after recurrent dislocations of a THA may occur. The lack of adherence to critical treatment may have led to the severe outcome of amputation. In conclusion, patient education and compliance are essential for both the treatment of hip dislocations and arterial occlusion. More active and effective measures should be used to prevent such catastrophic events.

[Evaluation of spino-pelvic mobility; its importance in preventing total hip replacement dislocation]. / Evaluación de la movilidad espino-pélvica; su importancia para prevenir la luxación de prótesis total de cadera.

Recently, it has been recognized that changes in sagittal alignment and spinopelvic mobility due to alterations of the lumbosacral spine can influence the dislocation of a hip replacement. The biggest difficulties for this problem are: a) the bibliography related to this topic has been written in English and there is confusion in its terminology; b) there is no consensus on what parameters should be used to identify, measure, and estimate the risks of dislocation occurring; c) the basic concepts that interrelate spinal disorders and prosthetic dislocation are not clearly understood; and d) spine and hip surgeons pursue different goals. The objective of this narrative review is to overcome the aforementioned difficulties by using a strategy to answer some questions: Is hip dislocation really a problem? What is the interrelationship between alterations in the pelvic spinal balance and the dislocation of a prosthesis? How is sagittal balance and lumbosacral mobility defined and how can their alterations be measured? What are their compensatory mechanisms to achieve a good functioning and how these mechanisms can be used to correctly orient the acetabulum? To document this review, we consulted the databases of PubMed, Scopus, SciELO and Google Scholar with the keywords: Spinopelvic, Total Hip Arthroplasty, Hip Dislocation, Spine-Pelvis-hip Arthroplasty. The articles that, in the author's opinion, were the most objective and/or relevant for the study of this topic were selected.

Recientemente se ha reconocido que los cambios en alineación sagital y la movilidad espino-pélvica por alteraciones de la columna lumbosacra pueden ejercer influencia en la luxación de una prótesis de cadera. Las mayores dificultades para este problema son: a) que la bibliografía relacionada con este tema se ha escrito en idioma inglés y hay confusiones en su terminología; b) no hay consenso de cuáles son los parámetros que deben utilizarse para identificarla, medirla y para estimar los riesgos de que ocurra una luxación; c) no se conocen con claridad los conceptos básicos que interrelacionen los trastornos de la columna y la luxación protésica; y d) que los cirujanos de columna y artroplásticos de cadera persiguen diferentes objetivos. Esta revisión narrativa persigue como objetivo allanar las dificultades antes mencionadas, utilizando como estrategia contestar algunas preguntas: ¿la luxación de cadera es realmente un problema?; ¿cuál es la interrelación entre las alteraciones en el balance espino-pélvico y la luxación de una prótesis?; ¿cómo se define el balance sagital y la movilidad lumbosacra y cómo se pueden medir sus alteraciones?; ¿cuáles son sus mecanismos compensatorios para lograr un buen funcionamiento, y cómo se pueden aprovechar estos mecanismos para orientar correctamente el acetábulo? Para documentar esta revisión se consultaron las bases de datos de PubMed, Scopus, SciELO y Google Académico con las palabras clave: Spinopelvic, Total Hip Arthroplasty, Hip Dislocation, Spine-Pelvis-hip Arthroplasty. Se seleccionaron los artículos que a juicio del autor fueron los más objetivos y/o relevantes para el estudio de este tema.

Use of the flat panel detector fluoroscope reduces radiation exposure during periacetabular osteotomy.

The Periacetabular Osteotomy is a technically demanding procedure that requires precise intraoperative evaluation of pelvic anatomy. Fluoroscopic images pose a radiation risk to operating room staff, scrubbed personnel, and the patient. Most commonly, a Standard Fluoroscope with an Image Intensifier is used. Our institution recently implemented the novel Fluoroscope with a Flat Panel Detector. The purpose of this study was to compare radiation dosage and accuracy between the two fluoroscopes. A retrospective review of a consecutive series of patients who underwent Periacetabular Osteotomy for symptomatic hip dysplasia was completed. The total radiation exposure dose (mGy) was recorded and compared for each case from the standard fluoroscope (n = 27) and the flat panel detector (n = 26) cohorts. Lateral center edge angle was measured and compared intraoperatively and at the six-week postoperative visit. A total of 53 patients (96% female) with a mean age and BMI of 17.84 (± 6.84) years and 22.66 (± 4.49) kg/m2 (standard fluoroscope) and 18.23 (± 4.21) years and 21.99 (± 4.00) kg/m2 (flat panel detector) were included. The standard fluoroscope averaged total radiation exposure to be 410.61(± 193.02) mGy, while the flat panel detector averaged 91.12 (± 49.64) mGy (p < 0.0001). The average difference (bias) between intraoperative and 6-week postoperative lateral center edge angle measurement was 0.36° (limits of agreement: - 3.19 to 2.47°) for the standard fluoroscope and 0.27° (limits of agreement: - 2.05 to 2.59°) for the flat panel detector cohort. Use of fluoroscopy with flat panel detector technology decreased the total radiation dose exposure intraoperatively and produced an equivalent assessment of intraoperative lateral center edge angle. Decreasing radiation exposure to young patients is imperative to reduce the risk of future comorbidities.

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.

Dual-mobility bearings reduce instability but may not be the only answer in revision total hip arthroplasty for recurrent dislocation.

Aims: There is little information in the literature about the use of dual-mobility (DM) bearings in preventing re-dislocation in revision total hip arthroplasty (THA). The aim of this study was to compare the use of DM bearings, standard bearings, and constrained liners in revision THA for recurrent dislocation, and to identify risk factors for re-dislocation. Methods: We reviewed 86 consecutive revision THAs performed for dislocation between August 2012 and July 2019. A total of 38 revisions (44.2%) involved a DM bearing, while 39 (45.3%) and nine (10.5%) involved a standard bearing and a constrained liner, respectively. Rates of re-dislocation, re-revision for dislocation, and overall re-revision were compared. Radiographs were assessed for the positioning of the acetabular component, the restoration of the centre of rotation, leg length, and offset. Risk factors for re-dislocation were determined by Cox regression analysis. The modified Harris Hip Scores (mHHSs) were recorded. The mean age of the patients at the time of revision was 70 years (43 to 88); 54 were female (62.8%). The mean follow-up was 5.0 years (2.0 to 8.75). Results: DM bearings were used significantly more frequently in elderly patients (p = 0.003) and in hips with abductor deficiency (p < 0.001). The re-dislocation rate was 13.2% for DM bearings compared with 17.9% for standard bearings, and 22.2% for constrained liners (p = 0.432). Re-revision-free survival for DM bearings was 84% (95% confidence interval (CI) 0.77 to 0.91) compared with 74% (95% CI 0.67 to 0.81) for standard articulations, and 67% (95% CI 0.51 to 0.82) for constrained liners (p = 0.361). Younger age (hazard ratio (HR) 0.92 (95% CI 0.85 to 0.99); p = 0.031), lower comorbidity (HR 0.44 (95% CI 0.20 to 0.95); p = 0.037), smaller heads (HR 0.80 (95% CI 0.64 to 0.99); p = 0.046), and retention of the acetabular component (HR 8.26 (95% CI 1.37 to 49.96); p = 0.022) were significantly associated with re-dislocation. All DM bearings which re-dislocated were in patients with abductor muscle deficiency (HR 48.34 (95% CI 0.03 to 7,737.98); p = 0.303). The radiological analysis did not reveal a significant relationship between restoration of the geometry of the hip and re-dislocation. The mean mHHSs significantly improved from 43 points (0 to 88) to 67 points (20 to 91; p < 0.001) at the final follow-up, with no differences between the types of bearing. Conclusion: We found that the use of DM bearings reduced the rates of re-dislocation and re-revision in revision THA for recurrent dislocation, but did not guarantee stability. Abductor deficiency is an important predictor of persistent instability.

The outcome of revision total hip arthroplasty for instability.

Aims: Instability is a common indication for revision total hip arthroplasty (THA). However, even after the initial revision, some patients continue to have recurrent dislocation. The aim of this study was to assess the risk for recurrent dislocation after revision THA for instability. Methods: Between 2009 and 2019, 163 patients underwent revision THA for instability at Stanford University Medical Center. Of these, 33 (20.2%) required re-revision due to recurrent dislocation. Cox proportional hazard models, with death and re-revision surgery for periprosthetic infection as competing events, were used to analyze the risk factors, including the size and alignment of the components. Paired t-tests or Wilcoxon signed-rank tests were used to assess the outcome using the Veterans RAND 12 (VR-12) physical and VR-12 mental scores, the Harris Hip Score (HHS) pain and function, and the Hip disability and Osteoarthritis Outcome score for Joint Replacement (HOOS, JR). Results: The median follow-up was 3.1 years (interquartile range 2.0 to 5.1). The one-year cumulative incidence of recurrent dislocation after revision was 8.7%, which increased to 18.8% at five years and 31.9% at ten years postoperatively. In multivariable analysis, a high American Society of Anesthesiologists (ASA) grade (hazard ratio (HR) 2.72 (95% confidence interval (CI) 1.13 to 6.60)), BMI between 25 and 30 kg/m2 (HR 4.31 (95% CI 1.52 to 12.27)), the use of specialized liners (HR 5.39 (95% CI 1.97 to 14.79) to 10.55 (95% CI 2.27 to 49.15)), lumbopelvic stiffness (HR 6.03 (95% CI 1.80 to 20.23)), and postoperative abductor weakness (HR 7.48 (95% CI 2.34 to 23.91)) were significant risk factors for recurrent dislocation. Increasing the size of the acetabular component by > 1 mm significantly decreased the risk of dislocation (HR 0.89 (95% CI 0.82 to 0.96)). The VR-12 physical and HHS (pain and function) scores improved significantly at mid term. Conclusion: Patients requiring revision THA for instability are at risk of recurrent dislocation. Higher ASA grades, being overweight, a previous lumbopelvic fusion, the use of specialized liners, and postoperative abductor weakness are significant risk factors.

Incidence, treatment, and outcomes of modern dual-mobility intraprosthetic dissociations.

Aims: Dual-mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a rare complication of DM that is believed to have decreased with contemporary implants. This study aimed to report incidence, treatment, and outcomes of contemporary DM IPD. Methods: A total of 1,453 DM components were implanted at a single academic institution between January 2010 and December 2021: 695 in primary and 758 in revision THA. Of these, 49 presented with a dislocation of the large DM head and five presented with an IPD. At the time of closed reduction of the large DM dislocation, six additional IPDs occurred. The mean age was 64 years (SD 9.6), 54.5% were female (n = 6), and mean follow-up was 4.2 years (SD 1.8). Of the 11 IPDs, seven had a history of instability, five had abductor insufficiency, four had prior lumbar fusion, and two were conversions for failed fracture management. Results: The incidence of IPD was 0.76%. Of the 11 IPDs, ten were missed either at presentation or after attempted reduction. All ten patients with a missed IPD were discharged with a presumed reduction. The mean time from IPD to surgical treatment was three weeks (0 to 23). One patient died after IPD prior to revision. Of the ten remaining hips with IPD, the DM head was exchanged in two, four underwent acetabular revision with DM exchange, and four were revised to a constrained liner. Of these, five (50%) underwent reoperation at a mean 1.8 years (SD 0.73), including one additional acetabular revision. No patients who underwent initial acetabular revision for IPD treatment required subsequent reoperation. Conclusion: The overall rate of IPD was low at 0.76%. It is essential to identify an IPD on radiographs as the majority were missed at presentation or after iatrogenic dissociation. Surgeons should consider acetabular revision for IPD to allow conversion to a larger DM head, and take care to remove impinging structures that may increase the risk of subsequent failure.

Impact of combined lumbar spine fusion and total hip arthroplasty on spine, pelvis, and hip kinematics during a sit to stand task.

Lumbar fusion is a risk factor for hip dislocation following total hip arthroplasty (THA). The objective was to compare joint/segment angles during sit-stand-sit in participants that had a THA with and without a lumbar fusion. The secondary objective was to compare pain, physical function, disability, and quality of life. This cross-sectional study includes participants that had THA and lumbar fusion (THA-fusion; n = 12) or THA only (THA-only; n = 12). Participants completed sit-stand-sit trials. Joint/segment angles were measured using electromagnetic motion capture. Angle characteristics were determined using principal component analysis. Hierarchical linear models examined relationships between angle characteristics and groups. Pain, physical function, and disability were compared using Mann-Whitney U tests. Upper lumbar spine was more extended during sit-stand-sit in the THA-fusion group (b = 42.41, P = 0.04). The pelvis was more posteriorly and anteriorly tilted during down and end sit-stand-sit phases, respectively, in the THA-fusion group (b = 12.21, P = 0.03). There were no significant associations between group and other angles. THA-fusion group had worse pain, physical function, disability, and quality of life. Although differences in spine joint, pelvis segment, and hip joint angles existed, these findings are unlikely to account for the increased incidence of hip dislocation after total hip arthroplasty in patients that had spine fusion.

Management of long bone fractures and traumatic hip dislocations in paediatric patients: study protocol for a prospective global multicentre observational cohort registry.

INTRODUCTION: Management controversy and clinical equipoise exist in treatments of long bone fractures and traumatic hip dislocation in paediatric patients due to the lack of high-quality clinical evidence. This protocol describes the effort of a large prospective global multicentre cohort study (registry) aiming at providing quality data to assist evidence-based treatment decision-making. METHODS AND ANALYSIS: Eligible paediatric patients (N=750-1000) with open physes suffering from proximal humerus fractures, distal humerus fractures, proximal radius fractures, forearm shaft fractures, traumatic hip dislocations, femoral neck fractures or tibial shaft fractures will be recruited over a period of 24-36 months. Hospitalisation and treatment details (including materials and implants) will be captured in a cloud-based, searchable database. Outcome measures include radiographic assessments, clinical outcomes (such as range of motion, limb length discrepancies and implant removal), patient-reported outcomes (Patient Reported Outcomes Of Fracture, Patient-Reported Outcomes Measurement Information System (PROMIS) and EuroQol-5D (EQ-5D-Y)) and adverse events.Aside from descriptive statistics on patient demographics, baseline characteristics, types of fractures and adverse event rates, research questions will be formulated based on data availability and quality. A statistical analysis plan will be prepared before the statistical analysis. ETHICS AND DISSEMINATION: Ethics approval will be obtained before patients are enrolled at each participating site. Patient enrolment will follow an informed consent process approved by the responsible ethics committee. Peer-reviewed publication is planned to disseminate the study results. TRIAL REGISTRATION NUMBER: NCT04207892.

Does Size Really Matter? Incidence of Periprosthetic Fractures After Femoral Osteotomy in Patients With Cerebral Palsy.

OBJECTIVE: Of children, 30% to 35% with cerebral palsy (CP) develop hip subluxation or dislocation and often require reconstructive hip surgery, including varus derotation osteotomy (VDRO). A recent literature review identified postoperative fractures as the most common complication (9.4%) of VDROs. This study aimed to assess risk factors for periprosthetic fracture after VDRO in children with CP. METHODS: A total of 347 patients (644 hips, 526 bilateral hips) with CP and hip subluxation or dislocation (129 females; mean age at index VDRO: 8.6 y, SD 3.4, range: 1.5 to 17.7; 2 Gross Motor Function Classification System (GMFCS) I, 35 GMFCS II, 39 GMFCS III, 119 GMFCS IV, 133 GMFCS V, 21 unavailable) were included in this retrospective, single-group intervention (VDRO) study at a tertiary referral center. Imaging and clinical documentation for patients age 18 years or younger at index surgery, treated with VDRO were reviewed to determine demographic data, GMFCS level, surgeon, type of hardware implanted, use of anticonvulsants and steroids, type of postoperative immobilization, presence of periprosthetic fractures, fracture location and mechanism, and time from surgery to fracture. Potential determinants of periprosthetic fractures were assessed using mixed effects logistic regression. RESULTS: Of 644 hips, 14 (2.2%, 95% CI: 1.3%, 3.6%) sustained a periprosthetic fracture, at a median of 2.1 years postoperatively (interquartile range: 4.6 y, range: 1.2 mo to 7.8 y). Patients with a fracture had a median age at index surgery of 7.3 years (interquartile range: 4.3, range: 2.8 to 17.8; 1 GMFCS II, 6 GMFCS IV, 7 GMFCS V). Periprosthetic fractures were not significantly related to age at index surgery ( P = 0.18), sex ( P = 0.30), body mass index percentile ( P = 0.87), surgery side ( P = 0.16), anticonvulsant use ( P = 0.35), type of postoperative immobilization ( P = 0.40), GMFCS level ( P = 0.31), or blade plate size ( P = 0.17). Only surgeon volume significantly related to periprosthetic fracture (odds ratio = 5.03, 95% CI: 1.53, 16.56, P = 0.008), with the highest-volume surgeon also using smaller blade plates ( P < 0.01). CONCLUSIONS: Periprosthetic fractures after VDRO surgery in children with CP are uncommon, and routine hardware removal appears unnecessary. The data suggest that the common dogma of putting in the largest blade plate possible to maximize fixation may increase the risk of periprosthetic fracture. Due to the overall low fracture rate, especially when contextualized relative to the risk of hardware removal, a reactive approach to hardware removal appears warranted. LEVEL OF EVIDENCE: Level III-retrospective study (targeting varus derotational osteotomies in children with cerebral palsy).

A rare soccer-related injury: Traumatic posterior hip fracture-dislocation - Case series and overview of the literature.

BACKGROUND: Soccer is one of the most popular sports with millions of active professional and non-professional players worldwide. Traumatic hip dislocations are rare in soccer but can lead to major sequelae both physically and psychologically. The aim of this review was to obtain insight into the outcomes after surgerically repaired hip fracture-dislocation in soccer players as well as rehabilitation and prevention. METHODS: Two cases of a posterior hip fracture-dislocation that occurred during an amateur soccer match are presented and mechanism of injury, complications and rehabilitation were analysed. Follow-up of both patients was at least one year after surgery. Questionnaires and physical examinations were obtained to quantify and qualify outcome. RESULTS: In both cases the hip-dislocations were reduced within 3 h after injury. Semi-elective open reduction and internal fixation was performed within seven days. In one case, there was a concomitant Pipkin fracture and sciatic nerve neuropathy. There were no postoperative complications. Follow-up showed full of range of motion and normal hip functionality in both cases. However, both patients indicated a reduced quality of life and anxiety related to the accident. CONCLUSION: Traumatic hip fracture-dislocations during soccer practice are extremely rare. Despite uncomplicated fracture healing after surgery and return of hip function, both patients still suffer from psychological problems resulting in a decreased quality of life. Further research is required to enhance psychological outcomes, as well as to facilitate return to pre-injury levels of participation and engagement in sports following traumatic hip fracture-dislocations related to soccer.

Closed reduction of dislocated hip prosthesis using a traction table.

This article describes three cases in which a dislocated hip prosthesis was reduced by a new reduction technique - that we previously described - using traction table. The dissociation of a prosthesis is a rare but serious complication of closed reduction manoeuvre. The new reduction manoeuvre using a traction table may be a good option to avoid dissociation of the prosthesis during closed reduction for treatment of dislocation after total hip arthroplasty.

Instability in Patients With Lumbar Spine Disease Undergoing Posterior Approach and Lateral Approach Primary Total Hip Arthroplasty.

INTRODUCTION: Dislocation rates in patients who have fixed spinopelvic motion have been reported up to 20%. Few studies have directly compared dislocation rates in patients who have spine pathology undergoing total hip arthroplasty (THA) through different surgical approaches. This study compared postoperative dislocation rates in patients who had lumbar spine disease and underwent primary THA using a posterior or direct lateral approach. METHODS: Between 2011 and 2017, consecutive cohorts of primary THAs were retrospectively reviewed. One surgeon routinely used a posterior approach, while the other used a direct lateral approach. Chart and radiographic review were conducted to identify patients who had lumbar spine disease. Dislocations among cohorts with and without lumbar spine disease were compared by posterior and direct lateral approaches. RESULTS: The overall dislocation rate was 1.3% (15/1,198). The top four predictors of dislocation were presence of lumbar spine disease (odds ratio [OR] 5.0; P = 0.014), posterior surgical approach (OR, 6.5; P = 0.074), cases performed for fracture (OR, 4.4; P = 0.035), and women (OR, 4.6; P = 0.050). Dislocation rates among direct lateral approach patients who had lumbar spine pathology were significantly lower than posterior approach patients who had lumbar spine pathology (0.0% versus 3.6%; P = 0.011). DISCUSSION: Although dislocation rates were low in both groups, study results suggest that a direct lateral approach for primary THA may reduce postoperative dislocations for patients who have limited spinopelvic motion due to lumbar spine pathology. Furthermore, surgeons using the posterior approach might consider optimizing the femoral head to acetabular cup ratio in patients who have lumbar spine disease.

Hip reduction surgery versus scoliosis correction in non-ambulant neuromuscular patients: which surgery is the first step?

PURPOSE: Children and young adults with neuromuscular disorders have a high incidence of both spine and hip deformities. The aim of this study was to evaluate the outcome of either primary scoliosis or hip surgery in children and young adults with neuromuscular disorders. METHODS: A retrospective study was conducted on all children and young adults with neuromuscular-related synchronous hip subluxation/dislocation and scoliosis undergoing hip or scoliosis surgery in our institution between 2012 and 2021 with a minimum follow-up of 24 months. Demographic and operative data were collected; radiological parameters were measured preoperatively and postoperatively at final follow-up. RESULTS: Forty neuromuscular patients with synchronous hip displacement and scoliosis were included. Twenty patients with an average age of10.2 years had hip correction surgery performed primarily, with a mean follow-up of 54.9 (24-96) months. The other 20 patients with an average age of 12.4 years had scoliosis correction first, with a mean follow-up of 40 (24-60) months. In the "Hip first" group, pelvic obliquity, hip MP and Cobb angle were 16.8°, 71%, and 49°, respectively. At final follow-up, the mean pelvic obliquity and Cobb angles significantly progressed to 27.2° (p = 0.003) and 82.2° (p = 0.001), respectively. Eighteen patients (90%) required scoliosis correction after the hip surgery. In the "Scoliosis first" group, the mean pelvic obliquity, hip MP and Cobb angle were 21.2°, 49% and 65.5°, respectively. At final follow-up, both pelvic obliquity and Cobb angle significantly improved to 8.44° (p = 0.002) and 23.4° (p = 0.001), respectively. In 11/20 (55%) patients, the hip MP had significantly increased following the spinal surgery to 62% (p = 0.001), but only 5/20 (25%) patients underwent hip surgery after scoliosis correction. CONCLUSION: In neuromuscular patients presenting with synchronous hip displacement and scoliosis deformity, corrective scoliosis surgery is associated with a significant correction of pelvic obliquity and lower rates of secondary hip surgery. On the other hand, primary hip surgery does not reduce the risk of pelvic obliquity and scoliosis deformity progression.

The relationship between hip displacement, scoliosis, and pelvic obliquity in 106 nonambulatory children with cerebral palsy: a longitudinal retrospective population-based study.

BACKGROUND AND PURPOSE: The relationship between hip displacement (HD), pelvic obliquity (PO), and scoliosis in nonambulatory children with cerebral palsy (CP) has not been clearly elucidated. The aims of this population-based study were to examine the prevalence and temporal sequence of these deformities in nonambulatory children with CP and to evaluate how probable it is that severe unilateral HD contributes to development of scoliosis. PATIENTS AND METHODS: This longitudinal study comprised 106 nonambulatory children, enrolled in a surveillance program. Pelvic radiographs for measurements of migration percentage (MP) and PO were taken once a year from the diagnosis of HD. Spine radiographs were taken in patients with clinically detected scoliosis. Radiographic follow-up continued until skeletal maturity. RESULTS: Clinically significant scoliosis (Cobb angle ≥ 40°) occurred in 60 patients at a mean age of 11.8 years. 65 patients developed clinically significant HD (MP ≥ 40%) at a mean age of 4.8 years. 24 patients had no significant hip or spine deformities, 22 had HD only, 17 had scoliosis only, and 43 had both deformities. HD was diagnosed before scoliosis in all except 1 of the patients with both deformities. 14 of 19 patients with severe unilateral HD (MP ≥ 60%) had scoliosis convexity to the opposite side of the displaced hip. CONCLUSION: The combination of scoliosis and HD was frequent, and HD was diagnosed first in almost all the patients. HD might be a contributory cause of scoliosis in patients with severe, unilateral HD, PO, and later scoliosis with convexity to the opposite side.

Insufficient stem antetorsion and lower cup abduction is a combined risk factor for posterior hip dislocation in patients undergoing THA for femoral neck fractures: a retrospective analysis.

BACKGROUND: The role of acetabular and femoral component positions with respect to the risk of post-operative instability and dislocation remains debated. In this study, we aimed to identify potential risk factors for early dislocation following primary total hip arthroplasty (THA) for displaced intracapsular femoral neck fractures (FNF) using radiological measurements. METHODS: We retrospectively analyzed data for patients who underwent cementless primary THA for FNF using a posterolateral approach between January 2018 and December 2021. Follow-up duration, age, sex, affected side, and mean time from THA to dislocation were recorded. Leg-length inequality, abductor lever arm, vertical and horizontal femoral offsets, vertical and horizontal hip centers of rotation, abduction, anteversion of the acetabulum and femoral prosthesis, and combined anteversion were measured. RESULTS: The study sample included 17 men and 34 women, with 21 and 30 patients undergoing left- and right-hip operations, respectively. The mean patient age was 70.18 ± 7.64 years, and the mean follow-up duration was 27.73 ± 13.52 months. The mean time between THA and dislocation was 1.58 ± 0.79 months. Seven patients (13.73%) sustained posterior dislocation of the hip. The abduction angle (36.05 ± 6.82° vs. 45.68 ± 8.78°) (p = 0.008) and anteversion of the femoral prosthesis (8.26 ± 4.47° vs. 19.47 ± 9.01°) (p = 0.002) were significantly lower in the dislocation group than in the control group. There were no significant differences in other parameters. CONCLUSIONS: Insufficient stem antetorsion combined with lower abduction angle of the acetabular component were associated with a high risk of dislocation, especially in patients with deep flexion or internal rotation of the flexed hip joint and knees, or in patients with a stiff spine or anterior pelvic tilt, impingement may then occur in the neck of the prosthesis and cup component, ultimately resulting in posterior dislocation. These findings could remind surgeons to avoid simultaneous occurrence of both in THA surgery. These results provide new insight into risk factors for hip dislocation in patients undergoing primary THA for FNF and may aid in reducing the risk of instability and dislocation. LEVEL OF EVIDENCE: Prospective comparative study Level II.

Prior hip arthroscopy increases the risk of dislocation, reoperation, and revision after hip arthroplasty: An updated meta-analysis and systematic review.

BACKGROUND: The indications for hip arthroscopy have been increasing, as have been the number of patients undergoing total hip arthroplasty (THA) after hip arthroscopy. Several matched cohort studies have assessed the impact of prior hip arthroscopy on THA, but conflicting results have been observed. The purpose of this study was to evaluate the influence of prior arthroscopy on subsequent THA. METHODS: This systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 checklist. PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library were searched to identify relevant studies. Dichotomous variables were summarized qualitatively as a meta-analysis of pooled odds ratios (ORs) and 95% confidence intervals (CIs), and continuous variables were summarized as standardized mean differences and 95% CIs. P-values <0.05 were considered statistically significant. The risk of bias was evaluated for each study, as was publication bias. RESULTS: In patients who underwent hip arthroscopy prior to THA, the ORs for dislocation, reoperation, and revision were 2.02 (P = 0.01), 1.66 (P = 0.01), and 2.15 (P = 0.001), respectively. There were no significant between-group differences in the Harris Hip Score (HHS; P = 0.40), WOMAC (P = 0.069), FJS-12 (P = 0.77), estimated blood loss (P = 0.48), and surgical time (P = 0.16). CONCLUSIONS: Prior hip arthroscopy is a risk for postoperative dislocation, reoperation, or revision after conversion THA. However, prior hip arthroscopy has no effect on patient-reported outcomes, or operative factors such as surgical time and blood loss.