Contracture of the deltoid muscle: imaging findings in 17 patients

Soft Tissue Lengthening for Flexion Dislocation of Patella

PURPOSE OF REVIEW

Obligatory dislocation of the patella (also known as habitual dislocation) is a rare subset of patellofemoral instability in which the patella dislocates every time the knee is flexed. The problem arises due to contracture of the quadriceps muscles. Soft tissue lengthening procedures such as quadriceps tendon lengthening are the mainstay of treatment, in contrast to medial patellofemoral reconstruction (MPFL-R) for the more common recurrent lateral patellar dislocation. The current review explores the existing literature surrounding the pathophysiology and treatment strategies for this unique cause of knee instability.

RECENT FINDINGS

Flexion dislocation of the knee often presents in children when they begin to walk. It is also termed obligatory or habitual because the patella dislocates laterally with each flexion and extension cycle of the knee. In contrast to other forms of patellar dislocation, the displacement is painless in obligatory dislocation. Likewise, the underlying biomechanical cause of this issue is related to contracture of tissues lateral to the patella rather than disruption of medial soft tissues as seen in recurrent/traumatic dislocation or subluxation of the patella. A number of procedures have been described for management of obligatory dislocation of the patella, with the general consensus that a combination of procedures including release/lengthening of the proximal lateral soft tissues as a critical component for a successful outcome. Soft tissue release/lengthening has been performed for over 50 years to treat obligatory dislocation of the patella. This procedure must be used in combination with other proximal and distal reconstructive with careful intraoperative assessment of knee flexion and patellar tracking for satisfactory outcomes. Further research using standardized outcome measures is needed to identify the optimal step-wise approach in treatment of obligatory patellar dislocation.

MR Imaging of Atraumatic Muscle Disorders

Atraumatic disorders of skeletal muscles include congenital variants; inherited myopathies; acquired inflammatory, infectious, or ischemic disorders; neoplastic diseases; and conditions leading to muscle atrophy. These have overlapping appearances at magnetic resonance (MR) imaging and are challenging for the radiologist to differentiate. The authors organize muscle disorders into four MR imaging patterns: (a) abnormal anatomy with normal signal intensity, (b) edema/inflammation, (c) mass, and (d) atrophy, highlighting each of their key clinical and imaging findings. Anatomic muscle variants, while common, do not produce signal intensity alterations and therefore are easily overlooked. Muscle edema is the most common pattern but is nonspecific, with a broad differential diagnosis. Autoimmune, paraneoplastic, and drug-induced myositis tend to be symmetric, whereas infection, radiation-induced injury, and myonecrosis are focal asymmetric processes. Architectural distortion in the setting of muscle edema suggests one of these latter processes. Intramuscular masses include primary neoplasms, metastases, and several benign masslike lesions that simulate malignancy. Some lesions, such as lipomas, low-flow vascular malformations, fibromatoses, and subacute hematomas, are distinctive, but many intramuscular masses ultimately require a biopsy for definitive diagnosis. Atrophy is the irreversible end result of any muscle disease of sufficient severity and is the dominant finding in disorders such as the muscular dystrophies, denervation myopathy, and sarcopenia. This imaging-based classification, in correlation with clinical and laboratory data, will aid the radiologist in interpreting MR imaging findings in patients with atraumatic muscle disorders. ^©RSNA, 2018.

Congenital gluteus maximus contracture syndrome--a case report with review of imaging findings

Although the clinical features of gluteus maximus contracture syndrome have been frequently described, imaging features have been seldom described. Most commonly reported cases are those following intramuscular injection in the gluteal region although congenital contracture is an uncommon but important occurrence. This condition has most often been reported in children of school going age. These patients often present with difficulty in squatting, limitation of hip motion or specific deformities and often require surgical correction. We describe the plain radiography, ultrasonography (USG) and magnetic resonance imaging (MRI) features of this condition in a patient with no previous known history of intramuscular injections.

The deltoid, a forgotten muscle of the shoulder

The deltoid is a fascinating muscle with a significant role in shoulder function. It is comprised of three distinct portions (anterior or clavicular, middle or acromial, and posterior or spinal) and acts mainly as an abductor of the shoulder and stabilizer of the humeral head. Deltoid tears are not infrequently associated with large or massive rotator cuff tears and may further jeopardize shoulder function. A variety of other pathologies may affect the deltoid muscle including enthesitis, calcific tendinitis, myositis, infection, tumors, and chronic avulsion injury. Contracture of the deltoid following repeated intramuscular injections could present with progressive abduction deformity and winging of the scapula. The deltoid muscle and its innervating axillary nerve may be injured during shoulder surgery, which may have disastrous functional consequences. Axillary neuropathies leading to deltoid muscle dysfunction include traumatic injuries, quadrilateral space and Parsonage-Turner syndromes, and cause denervation of the deltoid muscle. Finally, abnormalities of the deltoid may originate from nearby pathologies of subdeltoid bursa, acromion, and distal clavicle.

The role of ultrasonography in the diagnosis of gluteal muscle contracture

AIM

To evaluate the use of ultrasonography (US) in the diagnosis of gluteal muscle contracture (GMC) by analysis of its imaging characteristics.

MATERIALS AND METHODS

Thirty-nine patients suspected of having GMC due to abnormal gait underwent pre-operative US.

RESULTS

The diagnosis of GMC was confirmed by surgery in 27 patients. Six patients were diagnosed with congenital hip dysplasia, and the remaining six patients were diagnosed with sciatic nerve damage, post-poliomyelitis sequelae, and myasthenia gravis. For the patients with GMC, US showed muscle thinning and hyperechoic strips (specific for muscular contracture) in the muscles involved. In three patients with GMC, the strips were integrated into muscle bundles, demonstrating both strong and weak sonographic echoes. The sensitivity and specificity of the diagnosis of GMC using the presence of strips were 88.9% and 83.3%, respectively, and using muscle thinning, the sensitivity and specificity were 92.6% and 50%, respectively. The contracture strips, as measured by US, were significantly smaller than the actual measurements at the time of surgery, but there was a significant correlation between the two measurements (r = 0.814, P < 0.01). The highest detection rate of GMC by US was found in the gluteus maximus muscle (91.8%), and the lowest rate was found in the piriformis muscle (52.9%).

CONCLUSION

Ultrasonography is a valuable tool for the diagnosis of GMC, especially for the detection of specific contracture strips in involved muscles. Its role in the pre-operative diagnosis of GMC also provides surgical planning that can guide subsequent treatment.

Deltoid contracture mimicking shoulder dislocation in a 7-year-old boy

Contracture of the deltoid muscle, a relatively uncommon disorder in children, can be caused by repeated intramuscular injection, trauma, or congenital disease. The typical clinical manifestations of deltoid contracture (i.e., a palpable fibrous cord within the deltoid muscle, abduction contracture of the shoulder, winged scapula, and skin dimpling over the fibrous bands), however, may be atypical or even lacking, thus, leading to misdiagnosis. The procedure going from misdiagnosis to recognition of the correct diagnosis is reviewed in a 7-year-old boy with deltoid contracture.

Deltoid contracture: a case with multiple muscle contractures

Deltoid contracture is relatively uncommon. The literature consists primarily of case reports and few articles on large case series. The pathogenesis has been well studied. Muscle contractures can occur in the deltoid, biceps, triceps, gluteus and quadriceps muscles; however, cases of multiple muscle contractures are rare. We reported a patient with multiple contractures of the bilateral deltoid, bilateral gluteus, and bilateral quadriceps muscles, who had received repeated intramuscular injections during childhood and adulthood. The radiographic, including magnetic resonance imaging (MRI), features of the bone and joint abnormalities are presented. Some literatures reported that damage to the structures of the body due to intramuscular injection is related to the site of injection, age of the patient, and the volume, pH, chemical composition, and diffusional capacity of the injectate. Our patient had muscular contracture induced by needle injection regardless of her age, medication and injection site.

Deltoid contracture: a study of nineteen cases

OBJECTIVE

Deltoid contracture is not uncommon in India. Contractures of deltoid often do not have definite etiology. We have critically analyzed the condition as regards the etiopathogenesis and its surgical results.

MATERIALS AND METHODS

Nineteen patients with deltoid contracture operated between June 1990 and September 2001 were enrolled for a unicentric retrospective study. The surgery was indicated in patients with abduction deformity of more than 30 degrees at the shoulder. The etiology of deltoid contracture was idiopathic (n = 13) intramuscular injection in deltoid muscle (n = 5) and blunt trauma (n = 1). All were operated by distal release (incision near the insertion of the deltoid muscle). The average follow-up was of 9.5 years (range 6-17 years). They were evaluated based on parameters like pain, persistence of deformity, range of shoulder movements and strength of deltoid.

RESULTS

All patients recovered painless full range of shoulder motion except one. The correction of deformity was achieved in all patients and there was no loss of strength of deltoid compared to the opposite side. Histology of excised tissue showed features of chronic inflammation. The complications observed were hypertrophic scar (n = 1), painful terminal restriction of shoulder movements (n = 1) and prominent vertebral border of scapula (n = 1).

CONCLUSION

Deltoid contracture has features of chronic inflammation, and the intramuscular deltoid injection is the most incriminating factor in its etiopathogenesis. The condition can be effectively managed surgically by distal release of the deltoid muscle combined with excision of the muscular fibrotic contracture band.

MRI Diagnosis of Contracture of the Gluteus Maximus Muscle

OBJECTIVE

The objective of our study was to describe MRI features of contracture of the gluteus maximus muscle after providing a retrospective review of the MRI studies of 21 patients.

CONCLUSION

Gluteal contracture manifests characteristic features on MRI, including an intramuscular fibrotic cord extending to the thickened distal tendon with atrophy of the gluteus maximus muscle and posteromedial displacement of the iliotibial tract. In advanced cases, medial retraction of the muscle and its tendon results in a depressed groove at the muscle-tendon junction and external rotation of the proximal femur. Clinical correlation and meticulous physical examination may confirm the MR diagnosis.

Imaging Factors Related to Rotator Cuff Tear in Patients with Deltoid Contracture

BACKGROUND

Bony deformity and muscular malfunction around the shoulder induced by deltoid contracture may influence rotator cuff function and lead to subsequent tearing. The purpose of this study was to investigate the imaging and clinical factors related to rotator cuff tear in patients with deltoid contracture.

METHODS

We retrospectively reviewed 48 shoulders in 44 patients with magnetic resonance imaging diagnosis of deltoid contracture and surgically-proven rotator cuff tear. These shoulders were subdivided into partial-thickness and full-thickness tear groups. Another 17 shoulders in 17 patients with deltoid contracture but no evident rotator cuff tear were included as the control group. The characteristics, including age, gender and imaging features, of these three groups were compared.

RESULTS

Two patients who underwent initial operations for cuff tears required secondary operations for distal release of deltoid contracture. The age of patients with full-thickness tear was significantly greater than that of patients with partial-thickness tear or without tear. The winging angle of the glenoid (WAG) in the full-thickness tear group was significantly greater than that in the partial-thickness tear group. Patients with partial-thickness tear also had greater WAG than those without tear. However, WAG was not significantly correlated with the fibrotic size or age of the patient.

CONCLUSION

In patients with deltoid contracture, age and WAG are associated with the development of rotator cuff tear. To prevent the occurrence of rotator cuff tear, early surgical release of deltoid contracture is highly recommended, especially in patients with greater WAG.

Contracture of the Deltoid Muscle: Sonographic Evaluation with MRI Correlation

OBJECTIVE

This article evaluates the sonographic features of deltoid contracture (DC) with MRI correlation.

MATERIAL AND METHODS

Two reviewers evaluated the imaging features in 22 painful shoulders of 20 patients with a sonographic diagnosis of DC and a subsequent confirming MRI study. The sonographic and MRI findings with regard to the lesion extent (assessed by a 3-point scale: 1 = less than or equal to one third of the longitudinal deltoid length involved, 2 = greater than one third and less than or equal to two thirds involved, and 3 = greater than two thirds involved), transverse lesion morphologic appearance, and maximal transverse diameter measured were compared with kappa statistics and Wilcoxon's signed rank test, respectively.

RESULTS

Compared with MRI, there were two false-positive diagnoses of DC on sonography. Among the 20 true-positive diagnoses, sonography showed good agreement with MRI in assessing the lesion extent (kappa = 0.796, p < 0.001). Three sonographic lesion morphologic patterns for hyperechoic lesions (I = with multiple < 8-mm hypoechoic spots, II = heteroechoic lesions with predominant 8-15-mm hypointense areas, and III = > 15-mm calcified nodules, respectively) showed excellent agreement with three MRI lesion patterns (I = multiple < 8-mm hypointense spots, II = predominant 8-15-mm hypointense areas, and III = > 15-mm hypointense nodules, respectively) (kappa = 0.921, p < 0.001). However, the maximum lesion diameters appeared significantly larger on sonography than on MRI (2.8 +/- 0.6 cm vs 2.0 +/- 0.8 cm, mean +/- SD; p < 0.001), which was plausibly ascribed to the better sonographic delineation of hyperechoic immature fibrotic tissues.

CONCLUSION

Sonography is helpful for evaluating DC and correlates well with MRI.

MR abnormalities of the lateral pterygoid muscle in patients with nonreducing disk displacement of the TMJ

The aim of this study was to investigate the pathological changes of the lateral pterygoid muscle (LPM) using magnetic resonance imaging (MRI) in patients with anterior disk displacement with nonreduction (ADDnr) of the temporomandibular joint (TMJ) and to compare the abnormal findings of the LPM with the clinical symptoms and other pathological MRI alterations of the TMJ. Bilateral or unilateral ADDnr was demonstrated in 142 patents by MRI (176 TMJs; 106 females; 36 males; range 19 to 72 years; mean 43.9 years). In 123 TMJs, the LPMs were clearly observed in MRIs and analyzed in this study. Pathological changes of the LPM were found in 92 TMJs (74.8%) in MRI. Hypertrophy, atrophy and/or contracture were detected in the superior belly of the LPM (SBLPM) (35.8%, 44/123) or in the inferior belly of the LPM (IBLPM) (9.8%, 12/123) or in both bellies (29.3%, 36/123). The pathological changes of the LPM in MRI presented a significant association with the main clinical symptoms of TMJs with ADDnr, i.e. pain on jaw movement (P<0.01), pain in the LPM (P<0.01), pain in TMJ (P<0.05) and restricted jaw opening (P<0.05). The proportion of the abnormalities in LPM was significantly lower in TMJs with condylar limitation (63.6%) than in TMJs with condylar hypermobility (83.3%) and normal motion (88.9%)(P=0.008). Osteoarthritis was found to be correlated with condylar limitation (P<0.01). The results of this study indicate that the pathological changes of the LPM in TMJs with ADDnr could be detected by MRI and have a significant association with the main clinical symptoms of the patients. When condylar limitation happened, on the contrary, the pathological changes of the LPM in MRI were reduced. The alteration of the clinical symptoms in the patents with ADDnr might be associated with the pathological situations and symptoms of the LPM.

Deltoid contracture: MR imaging features

AIM

To describe the magnetic resonance imaging (MRI) features of deltoid contracture and compare these findings with the operative and histological findings and to determine the utility of MRI for diagnosis and treatment planning.

PATIENTS AND METHODS

Retrospective review of clinical and imaging in six patients with deltoid contracture, as well as the operative and histological findings of four operated patients.

RESULTS

Magnetic resonance imaging clearly demonstrated the intramuscular fibrous bands of the deltoid as a homogeneously hypointense area with distinctive margins on T1-, T2- and T2*-weighted images. Operative findings were exactly consistent with the findings observed by MRI.

CONCLUSION

Deltoid contracture is best evaluated with MRI which facilitates visualization of the intramuscular fibrous bands being pathognomonic of this entity and may provide information useful in treatment planning.