Abductor Dysfunction Research Articles

Comparison of Gait and Functional Outcomes Between Open and Arthroscopic Treatment of Adolescent and Young Adult Femoroacetabular Impingement.

Management of femoroacetabular impingement (FAI) through an arthroscopic or surgical hip dislocation (SHD) approach has been shown to have similar clinical success and patient-reported outcomes. However, there are limited data comparing functional outcomes. The purpose of this study was to compare gait and functional outcomes of adolescent/young adult patients with FAI treated by either an arthroscopic or open SHD approach. We identified prospectively enrolled adolescent/young adult patients (≤20 years old) who underwent surgical treatment for FAI through an SHD or arthroscopic approach. Participants were evaluated in a movement science lab preoperatively and postoperatively (minimum 8 months postoperatively) with barefoot walking and a 30-second single-limb balance trial on the affected side. Participants also completed the Harris Hip Score at the same timepoints. Differences from preoperative to postoperative were determined using a paired-samples t test for each surgical technique, and differences between the SHD and arthroscopic groups were determined using an independent samples t test (α=0.05). Fifty-five participants (42F, 16.2±1.4y) were tested and grouped by surgical intervention. The SHD and arthroscopy groups consisted of 28 and 27 participants, respectively, with no significant difference between the SHD and arthroscopic cohorts in age (16.4±1.2 vs. 15.9±1.5y, respectively, P=0.218) or sex distribution (78.6% vs. 74.1% females, respectively, P=0.75). Each group demonstrated significant postoperative improvement in Harris Hip Score (SHD: 64.8±16.4 to 81.8±17.8; arthroscopy: 57.0±16.7 to 84.7±19.7; preoperatively to postoperatively, respectively, both P<0.001). During gait, increased maximum hip flexion was observed following surgical intervention for the SHD group (32.3±5.7 vs. 36.1±5.2, P=0.003). No other clinically significant changes were detected in the SHD or arthroscopic groups preoperatively to postoperatively in trunk, pelvis, or hip kinematics in the coronal plane. During the balance task, neither cohort demonstrated markers of clinically significant abductor dysfunction. However, post operatively, the arthroscopy group was able to balance longer than the SHD group (18.8±7.8 vs. 14.2±2.7s, respectively, P=0.008), although no differences were detected in trunk or pelvis position in the coronal plane during balance. Both open SHD and arthroscopic treatment of FAI resulted in improved clinical outcomes with no clinically significant abductor dysfunction 1 year post operatively. However, further study is needed to determine whether more dynamic tasks can potentially elicit subtle differences between the groups. Level II-prospective study.

The surgical destabilization ofthe abductor muscle leads to development ofinstability-associated hip osteoarthritis inmice.

Osteoarthritis (OA) of the hip is a common and debilitating painful joint disease. However, there is paucity of surgically induced hip OA models in small animals that allow scientists to study the onset and progression of the disease. A growing body of evidence indicates a positive association between periarticular myotendinous pathology and the development of hip OA. Thus, in the current study, we aimed to establish a novel mouse instability-associated hip OA model via selective injury of the abductor complex around the hip joint. C57BL6/J mice were randomized to sham surgery or abductor injury, in which the myotendinous insertion at the third trochanter and greater trochanter were surgically detached. Mice were allowed free active movement until they were sacrificed at either 3 weeks or 20 weeks post-injury. Histologic analyses and immunohistochemical staining of the femoral head articular cartilage were performed, along with microCT (µCT) analysis to assess subchondral bone remodeling. We observed that mice receiving abductor injury exhibited significantly increased instability-associated OA severity with loss of proteoglycan and type II collagen staining compared to sham control mice at 20 weeks post-surgery, while comparable matrix metalloproteinase 13 expression was observed between injury and sham groups. No significant differences in subchondral bone remodeling were found after 3 or 20 weeks following injury. Our study further supports the link between abductor dysfunction and the development of instability-associated hip OA. Importantly, this novel surgically induced hip OA mouse model may provide a valuable tool for future investigations into the pathogenesis and treatment of hip OA.

Hip abductor dysfunction following total hip arthroplasty by modified direct lateral approach: Assessment by quantitative electromyography

Abstract Background The use of the direct lateral approach and its modifications for total hip arthroplasty (THA) may lead to postoperative abductor weakness. Assessment of abductor muscle function by the use of quantitative electromyography (EMG) aims to investigate the nature of abductor muscle dysfunction. Methods We conducted a study on 40 patients who had hip replacement through the modified direct lateral approach. EMG was performed before surgery on the affected and normal sides and repeated on the operated side after surgery by 6 and 12 weeks. Analysis of EMG of the three abductor muscles was done in all patients. Results EMG evidence of acute denervation of hip abductors was present in 15 hips (37.5%) after 6 weeks. Improvement of EMG findings occurred in 8 out of 15 patients. Quantitative electromyography (QEMG) showed early significant increase in amplitude in all muscles and decrease in duration in gluteus medius (G. Med) with a pattern of acute nerve injury. At 12 weeks, the values of duration, amplitude, and phase were insignificantly different from the preoperative values signifying the return of near normal muscle activity. Conclusion The use of modified direct lateral approach can cause denervation of hip abductors. It is common in the early postoperative weeks. However, it tends to improve and the residual weakness in some patients is not marked. Quantitative electromyography showed that partial denervation is related to superior gluteal nerve stretching and not to direct injury of the terminal branches of the nerve through the incision.

Abductor recovery after muscle-sparing periacetabular osteotomy using a lateral approach.

To decrease hip abductor dysfunction after periacetabular osteotomy using a lateral/trochanteric approach, we aimed to modify transposition osteotomy of the acetabulum (TOA) to not cut the greater trochanter and abductor-iliac crest detachment. We subsequently compared abductor muscle strength recovery between TOAs with [conventional TOA (C-TOA)] and without [modified TOA (M-TOA)] trochanteric osteotomy. C-TOA and M-TOA were performed in 27 and 34 hips, respectively. Hip abduction, flexion and knee extension muscle strength were measured preoperatively and at 3, 5, 10, 24 and 52 weeks postoperatively. The muscle strength ratio of the affected and contralateral lower limbs was compared between the C-TOA and M-TOA groups. Neither the mean Merle d'Aubigné-Postel score at the final follow-up nor the postoperative center-edge angle showed significant differences between the M-TOA and C-TOA groups (15.7 versus 16.4 points; P = 0.25 and 38.5° versus P = 0.62 and 39.8°, respectively). The mean muscle strength ratios of hip abduction at 5, 12 and 24 weeks postoperatively were significantly higher in the M-TOA group than in the C-TOA group (0.62 versus 0.39, 0.76 versus 0.59 and 0.94 versus 0.70; P = 0.03, 0.04 and 0.01, respectively). There were no significant differences between groups at Postoperative Week 52 (P = 0.36). Discomfort at the greater trochanter was observed in 18 hips (66.7%) in the C-TOA group but only in 4 hips (11.2%) in the M-TOA group. In conclusion, M-TOA is less invasive than C-TOA and allows an earlier recovery of abductor muscle strength without significant correction loss.

CORR Insights®: The External Obturator Footprint Is a Usable, Accurate, and Reliable Landmark for Stem Depth in Direct Anterior THA.

CORR Insights®: The External Obturator Footprint Is a Usable, Accurate, and Reliable Landmark for Stem Depth in Direct Anterior THA.

Stridor during sleep: description of 81 consecutive cases diagnosed in a tertiary sleep disorders center.

To describe the characteristics of stridor during sleep (SDS) in a series of adults identified by video-polysomnography (V-PSG). Retrospective clinical, V-PSG, laryngoscopic, and therapeutic data of patients diagnosed with SDS in a tertiary referral sleep disorders center between 1997 and 2017. A total of 81 patients were identified (56.8% males, age 61.8 ± 11.2 years). Related etiologies were multiple system atrophy (MSA), amyotrophic lateral sclerosis, spinocerebellar ataxia type 1, anti-IgLON5 disease, fatal familial insomnia, brainstem structural lesions, vagus nerve stimulation, recurrent laryngeal nerve injury, the effect of radiotherapy on the vocal cords, cervical osteophytes, and others. Stridor during wakefulness coexisted in 13 (16%) patients and in MSA was only seen in the parkinsonian form. Laryngoscopy during wakefulness in 72 (88.9%) subjects documented vocal cord abductor impairment in 65 (90.3%) and extrinsic lesions narrowing the glottis in 2 (2.4%). The mean apnea-hypopnea index (AHI) was 21.4 ± 18.6 and CT90 was 11.5 ± 19.1. Obstructive AHI > 10 occurred in 52 (64.2%) patients and central apnea index >10 in 2 (2.4%). CPAP abolished SDS, obstructive apneic events and oxyhemoglobin desaturations in 58 of 60 (96.7%) titrated patients with optimal pressure of 9.0 ± 2.3 cm H20. Tracheostomy in 19 (23.4%) and cordotomy in 3 (3.7%) subjects also eliminated SDS. SDS in adults is linked to conditions that damage the brainstem, recurrent laryngeal nerve, and vocal cords. V-PSG frequently detects obstructive sleep apnea and laryngoscopy usually shows vocal cord abductor dysfunction. CPAP, tracheostomy, and laryngeal surgery abolish SDS.

Physical Therapy Management of Patients With Chronic Low Back Pain and Hip Abductor Weakness.

Hip abductor dysfunction is common in individuals with chronic low back pain (CLBP). Previous research investigating abductor strengthening in the heterogeneous CLBP population is sparse and has failed to target those patients most likely to benefit. The aim of the current case series was to describe the physical therapy management and outcomes of 3 patients with CLBP matching a previously identified subgroup characterized by substantial hip abductor weakness. Three nonconsecutive patients with CLBP-a 77-year-old man, a 78-year-old woman, and an 85-year-old woman-were treated in an outpatient physical therapy clinic. All 3 patients matched a previously identified CLBP subgroup characterized by substantial hip abductor weakness. Patients were treated using a targeted exercise approach consisting mostly of hip abductor strengthening for 11 to 17 visits over 8 to 10 weeks. Patients received additional treatments including heel lift and pain neuroscience education when indicated. By discharge, all patients had made clinically important improvements in pain (3- to 7-point reduction on the Numeric Pain Rating Scale), function (10- to 16-point change on the Modified Oswestry Disability Index), and perceived improvement (6-7 on Global Rating of Change Scale). Lumbar range of motion was painless, and hip abductor strength was improved from 2+/5 to 3+/5 in all 3 patients. These gains were maintained at 3-month follow-up. The current case series describes the use of a targeted exercise approach consisting mostly of hip abductor strengthening in a group of patients with CLBP and hip abductor weakness. The results indicated that this approach may be effective in reducing pain and improving function, particularly for older patients.

Multivariate analysis of risk factors for re-dislocation after revision for dislocation after total hip arthroplasty.

The treatment for recurrent dislocation of a total hip arthroplasty is surgical using varied techniques and technologies to reduce the chances of re-dislocation and re-revision. The goal of this study is to compare operative techniques to reduce re-dislocation and re-revision in revision hip arthroplasty due to recurrent dislocations. A retrospective study of revision hip arthroplasties done due to recurrent dislocation prior to 01 January 2014. Electronic physician and provincial health records were used to collect patients' initial and follow-up data. Treatment failure was defined as either aseptic re-revision or re-dislocation without revision. Time to event was considered as the re-revision date or the date of second dislocation when the latter endpoint was used. Of 379 operations, 88 (23.2%) had aseptic repeat revision or recurrent dislocation. Of these: 66 (75.0%) due to dislocation with re-revision; 10 (11.4%) due to dislocation with no re-revision surgery; 5 (5.7%) due to aseptic loosening of components; 3 (3.4%) due to osteolysis; 3 (3.4%) due to pseudotumour; and 1 (1.1%) due to periprosthetic fracture. The following factors increase risk of failure: the use of augmented-liners (lipped, oblique and high-offset liners; HR = 1.68, 95% CI, 1.05-2.69), periprosthetic femur fracture (HR = 2.80, 95% CI, 1.39-8.21) and pelvic discontinuity (HR = 3.69, 95% CI, 1.66-8.21). Femur head sizes 36-40 mm are protective (HR = 0.54, 95% CI, 0.31-0.86). In abductor dysfunction the use of focal constrained liners decreases the risk of failure (HR = 0.13, 95% CI, 0.018-0.973). Larger head sizes and focal constrained liners (abductors dysfunction) should be used and fully constrained liners and augmented-liners should be avoided in a revision hip arthroplasty due to recurrent dislocations.

Abductor Dysfunction and Related Sciatic Nerve Palsy, a New Complication of Metal-on-Metal Arthroplasty

The optimal bearing for use in young patients with hip arthritis remains elusive. Current options include metal–on–cross-linked polyethylene, ceramic–on–cross-linked polyethylene, ceramic on ceramic, and metal on metal. Each of these bearing couples has advantages and disadvantages. Metal-on-metal designs allow the use of large heads that decrease impingement and improve stability. This fact has made this bearing an attractive option for surgeons and patients alike. This case report will illustrate a severe adverse reaction to metal debris with necrosis of soft tissues and subsequent damage to the sciatic nerve.

Acetabular Orientation: Anterolateral Approach in the Supine Position

The anterolateral approach in the supine position provides excellent visualization of the acetabulum. The main advantage of the approach, a low dislocation rate, has been demonstrated in the literature, while the purported disadvantage of abductor dysfunction has not been clearly delineated in the literature. The technique requires meticulous attention to preservation of the gluteus medius and minimus tendons. Impingement and dislocation are avoided by careful attention to the preparation of acetabulum, critical assessment of the implanted components, and intraoperative trialing. Leg lengths are assessed through direct palpation of the malleoli. Routine use of postoperative hip precautions is not necessary when this approach is utilized. The anterolateral approach in the supine position allows for a reproducible result with a low dislocation rate. Level V, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Strain pattern following surface replacement of the hip

The aim is to compare the strain pattern in intact and resurfaced femurs using validated third-generation composite femurs and rosette strain gauges. The rosette strain gauges were applied to an intact and a resurfaced third-generation composite femur at three sites: the narrowest part of the lateral surface of the neck, the narrowest part of the medial surface of the neck, and the medial surface at the level of the lesser trochanter. The maximum and minimum principal strains were calculated at axial loads of 600, 800, and 1000 N. Further tests were carried out with an additional abductor load. The maximum principal strains in the resurfaced femur were approximately 50 per cent higher in the lateral surface of the neck and about 25 per cent higher in the lesser trochanteric region than in the intact femur. Inclusion of the abductor force decreased the strains in both the intact and the resurfaced femurs, particularly at the lateral surface of the femoral neck. Increased strain at the lateral surface of the femoral neck following hip resurfacing could be a cause of neck fracture, particularly if there are other predisposing factors such as notching of the femoral neck and/or abductor dysfunction. Meticulous repair of the abductors is warranted if a lateral approach is used.

Total hip arthroplasty with a sliding iliac graft for acetabular dysplasia

We describe a new technique of reconstruction of the deficient acetabulum in cementless total hip arthroplasty. The outer iliac table just above the deficient acetabulum is osteotomised and slid downwards. We have termed this an iliac sliding graft. Between October 1997 and November 2001, cementless total hip arthroplasty with an iliac sliding graft was performed on 19 patients (19 hips) with acetabular dysplasia. The mean follow-up was 3.4 years (2 to 6). The mean pre-operative Harris hip score was 45.1 which improved significantly to 85.3 at the time of the final follow-up. No patient had post-operative abductor dysfunction. Incorporation of the graft was seen after two to three months in all patients. Resorption of the graft and radiolucencies were infrequent. This technique is a useful alternative to femoral head autografting when the patient's own femoral head cannot be used.

Curved Periacetabular Osteotomy for Treatment of Dysplastic Hip

The Bernese periacetabular osteotomy has a considerable rate of postoperative complications such as reflex sympathetic dystrophy, motor nerve palsy, heterotopic ossification, and delayed union of the ilium, which are assumed to be caused by extensive exposure or asphericity of the osteotomy surfaces. To address these issues, we developed the curved periacetabular osteotomy, a modification of the Bernese periacetabular osteotomy which limits dissection, prevents the outside of the ilium from being exposed, and produces osteotomy surfaces with the same curvature. Curved periacetabular osteotomies were done on 128 hips in 118 patients whose average age at the time of surgery was 35.2 years (range, 16-59 years). The average followup was 46 months (range, 24-99 months). The average center-edge angles were 4 degrees (range, -15 degrees -5 degrees ) preoperatively and 35 degrees (20 degrees -55 degrees ) postoperatively, and union of the iliac osteotomy was achieved in all hips. We experienced three asymptomatic pubic nonunions. Dysesthesias occurred in 27 patients along the lateral femoral cutaneous nerve and symptoms resolved in 23 patients within 1 year. The average Harris hip score improved from 72 to 93 points. There were no major complications such as sciatic nerve palsy, abductor dysfunction, or heterotopic ossification. Therapeutic study, Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Proximal femoral osteotomy: Current indications and techniques

Osteotomy of the proximal femur can be a useful procedure in the management of a number of different disorders around the hip. The ultimate goal of treatment is to reduce pain and prevent degeneration of the hip joint. The osteotomy can be done alone or in conjunction with other procedures in an attempt to fully address the pathology affecting the hip and lower extremity. Currently a regional variation seems to exist with regards to the indications, location, and value of these procedures, especially with the success of total hip arthroplasty (THA) in the patient with endstage arthrosis. However, with increasing numbers of replacement arthroplasty performed in young and active patients, there is a concomitant increase in the number of patients requiring challenging and complex revision procedures. Unfortunately this often leaves compromised bone stock and soft-tissue function. In our experience, obtaining a more functional native hip joint through osteotomy can delay the onset and progression of arthrosis, thereby delaying or even eliminating the need for THA. We believe that total hip arthroplasty and proximal femoral osteotomy should not be viewed as being in competition, rather each has its own distinct indications and when performed appropriately, has reproducible clinical results. Traditionally, a large proportion of femoral osteotomies were performed at the intertrochanteric region. 1-3 However, it should be noted that several other sites for performing proximal femoral osteotomy can be used to address pathology around the hip. These include an intracapsular subcapital, extracapsular base of the neck and subtrochanteric osteotomy. Osteotomy of the greater trochanter can also be used alone or in conjunction with other proximal osteotomies to help gain exposure to the hip joint and to address abductor dysfunction or trochanteric impingement. The purpose of this article is to present the indications, rationale, decision-making, and technical considerations for osteotomy of the proximal femur in the treatment of hip disorders prone to early degeneration. This article will focus primarily on the use of intertrochanteric and subcapital osteotomy.

両側声帯固定を呈したＳｈｙ‐Ｄｒａｇｅｒ症候群例

Shy-Drager syndrome has been labeled one type of multiple system atrophy. We report a patient with bilateral vocal cord abductor dysfunction and Shy-Drager syndrome.The patient was a 79-year-old male suffering from dysuria. In January 2003, he was referred with a complaint of nocturnal stridor lasting two years. Fiberscopic examination of the larynx revealed insufficient abduction of the bilateral vocal cords with a slight aperture. No definitive diagnosis regarding the nocturnal stridor was established at that time. Six months later he complained of deterioration of the nocturnal stridor. While he did not have any other symptoms of respiration, the laryngeal examination showed his bilateral vocal cords lying in the midline position. Three months later, languor and dizziness occurred after every meal. When he was hospitalized for examination, he experienced faintness after meals. His condition progressed from bad to worse. He began suffering from aspiration pneumonia, requiring artificial respiration with intubation. The next day, he was given a tracheostomy to prevent laryngeal obstruction. After his recovery from pneumonia, orthostatic hypotension and hypotension after meals were discovered. T2-weighted magnetic resonance images showed high-intensity areas in the pons, an abnormal sign indicating multiple system atrophy. The diagnosis of Shy-Drager syndrome was made from these clinical observations. We reviewed 13 reports mentioning the surgical treatment for bilateral abductor dysfunction with Shy-Drager syndrome. It is necessary in patients with bilateral abductor dysfunction to restore the airway in order to prevent nocturnal sudden death. 33 cases have been treated by tracheostomy (29 cases), vocal cord lateralization (3 cases), and selective resection of the adductor branch from the recurrent laryngeal nerve (1 case).It is important for physicians treating patients with bilateral abductor dysfunction to formulate an examination plan concerning nervous system degeneration diseases and to consider the indication for an operation to maintain the airway.

Rotational transfer of the vastus lateralis muscle for the treatment of the abductor deficient hip: a cadaveric feasibility study and initial clinical experience

Abductor insufficiency of the hip remains a difficult problem in orthopedic surgery. Although a variety of procedures have been described, abductor function cannot be satisfactorily restored. Because of the location and innervation of the vastus lateralis muscle, its transfer might provide a promising alternative to replacing dysfunctional hip abductors. Physiological cross-sectional area, muscle fiber length, and time of action during the gait cycle are all similar to the gluteus medius muscle. To investigate the potential usefulness of the vastus lateralis muscle for treating abductor dysfunction of the hip, we dissected 15 thighs, 6 of them after arterial injection with colored latex to further study the vascular supply. The vastus lateralis was found to be vascularized from branches of the lateral femoral circumflex artery in all specimens. In 14 cases, we found a dual innervation from the femoral nerve. The vastus lateralis muscle could be completely mobilized on its neurovascular pedicle and rotated 180° without difficulty. This allowed firm suture fixation to both the iliac crest and the greater trochanter. Clinically, the technique was used in 5 patients. In 2 patients with unfavorable biomechanics, the results were not satisfactorily. In the other 3 patients with normal biomechanics, the clinical results were satisfying. Based on our clinical experience, we feel that this transfer should be reserved for patients with an abductor-deficient hip, considerable associated functional loss, and few other reconstructive options. In the appropriately selected patient, this transfer can restore some of the abductor function.

Use of the Ilizarov technique to improve limb function following hemipelvectomy

Aims: Limb salvage surgery combined with tumour resection has become established in the management of pelvic tumours. However, subsequent reconstructive options for maintaineance of quality of life lead to varied outcomes. We present a hitherto undescribed use of the Ilizarov technique as a second stage adjunct, for the optimisation of function, after first stage tumour resection and arthrodesis.Methods: We describe the surgical technique used to address leg length discrepancy and abductor dysfunction following internal hemipelvectomy with ischifemoral arthrodesis. Distal femoral and distal tibial lengthening using circular frames, with a valgus subtrochanteric femoral osteotomy, enabled a rapid correction of both anomalies. Controlled varus correction at the distal femoral osteotomy site was performed to obtain a horizontal joint line at the knee.Conclusion: The Ilizarov technique is suitable for selected patients with tumour free survival following the initial resection. Our experience indicates that it is a good alternative to a mammoth one stage internal hemipelvectomy with reconstruction. The latter is often attempted even though there is a high risk of local recurrence and distant metastasis.

Continuous positive air pressure eliminates nocturnal stridor in multiple system atrophy

We prospectively studied the sleep patterns and laryngeal function of 20 patients with multiple system atrophy and found sleep disturbances in all subjects and vocal cord abduction dysfunction in 14 (70%). In three patients with nocturnal stridor and complete vocal cord abductor dysfunction, continuous positive airways pressure eliminated laryngeal stridor, obstructive apnoea, and haemoglobin desaturation.