An atypical inferior gluteal artery passing through the piriformis muscle.

PURPOSE: In this article, we report a case of an atypical inferior gluteal artery that passed through the piriformis muscle when it emerged from the pelvic cavity in an elderly Japanese female cadaver. We speculate that this atypical artery could be entrapped and compressed by the piriformis muscle and may therefore be associated with piriformis syndrome; however, the anatomical characteristics of such an atypical artery have not been previously reported. To assess this potential association, the atypical inferior gluteal artery was anatomically examined. METHODS: The cadaver examined in this report was a 97-year-old Japanese female who was donated to The Nippon Dental University for use in medical education and research. The atypical inferior gluteal artery and surrounding structures in half of the pelvis were examined macroscopically. RESULTS: The atypical inferior gluteal artery arose from the common arterial trunk, formed by itself and the superior gluteal artery, passed through the superior proximal part of the piriformis muscle, and left the pelvic cavity. It supplies branches to the lower half of the gluteus maximus and proximal part of the long head of the biceps femoris muscle. The piriformis muscle originates from the 2nd to 4th sacral vertebrae and attaches to the greater trochanter via a single short tendon. CONCLUSION: According to our findings, when the atypical inferior gluteal artery is entrapped and compressed, ischemic signs and symptoms may emerge in the lower buttocks and proximal posterior thigh. These results provide a new perspective for the diagnosis and treatment of piriformis syndrome.

Effect of hip external rotator muscle contraction on pelvic floor muscle function and the piriformis.

INTRODUCTION AND HYPOTHESIS: There is a lack of in-depth understanding of the muscles surrounding the pelvic floor muscle (PFM). The study aimed to investigate the functional relationship between PFM and hip external rotator muscles by observing the piriformis muscle thickness and displacement of the bladder base under different contraction conditions of the hip external rotator and/or PFM. We hypothesized that PFM function would be the strongest when the hip external rotator and PFM contracted simultaneously and that during PFM contraction, the piriformis muscle would act as an auxiliary muscle and show coactivation. METHODS: The participants included 13 healthy adult women (mean age 23.8 ± 2.8 years). The three contraction conditions were PFM contraction, hip external rotator contraction, and simultaneous contraction of the hip external rotator and PFM. During the tasks, the piriformis muscle thickness and bladder base displacement were measured using ultrasonography and compared among the contraction conditions using one-way analysis of variance. RESULTS: Significant differences were noted in bladder base displacement among the three contraction conditions (P < 0.01), with PFM contraction having the highest value. The piriformis muscle thickness showed the greatest increase in simultaneous contraction. CONCLUSIONS: In our study, we showed PFM contraction positively influences piriformis contraction, while PFM function operationalized by bladder base displacement was highest during PFM contraction alone.

Bifurcation of the sciatic nerve: A descriptive study on a South African cadaver cohort.

BACKGROUND: The sciatic nerve bifurcates into the tibial and common fibular nerves in six different regions: the pelvic region, gluteal region, proximal, middle, or distal third of the posterior thigh, or in the popliteal fossa. Inadequate knowledge of sciatic nerve anatomy could lead to failed nerve blocks, and damage during intramuscular injections. Limited studies have been done on African population groups and lack a quantifiable method to classify the levels of sciatic nerve bifurcation. AIM: Thus, this descriptive cadaver study aimed to assess the bifurcation level of the sciatic nerve in a South African population group using a quantifiable method. METHODS: Three hundred and thirty-eight formalin-fixed limbs from three universities were dissected between March and August 2018. Type A was classified if the sciatic nerve bifurcated within the pelvic region. A sciatic nerve bifurcation level index (SNBLI) was developed for this study to quantitatively classify the region of sciatic nerve bifurcation into types B to F. RESULTS: Type F bifurcation was most common (79.6%), and types B and C were not observed. In 15 (0.04%) specimens, two separate nerves entered the gluteal region and converged to form the sciatic nerve distal to the piriformis, which could bifurcate either in the distal third of the posterior thigh or popliteal fossa. CONCLUSION: This is the first study to provide information on the sciatic nerve bifurcation in a large South African cadaver cohort. Moreover, we created a quantifiable method that can be used to classify the sciatic nerve bifurcation level. This will be beneficial in ensuring accurate comparison between different population groups in future.

Does piriformis muscle syndrome impair postural balance? A case control study.

BACKGROUND AND PURPOSE: While patients with musculoskeletal disorders reported postural balance impairments, it is unknown whether patients with piriformis muscle syndrome (PMS) may exhibit postural balance disorders compared to controls. The aim was to compare postural balance in patients with PMS to controls in static and dynamic conditions. MATERIAL AND METHODS: Twelve patients with PMS and twelve controls were enrolled. Static postural balance was assessed by calculating the symmetry index (SI) in the unipedal posture. To measure vision contribution, the Romberg index (RI) was computed. Dynamic postural balance was evaluated with the Timed up and go test (TUGT). Besides, inter-limb strength asymmetry (SA), pain and the short form-36 (SF-36) were assessed. RESULTS: The PMS group (PMSG) exhibited significant (p < 0.001) higher SI in eyes opened (EO) and eyes closed (EC) conditions compared to the control group (CG). Besides, PMSG had significant higher RI (p < 0.05), TUGT scores (p < 0.001), SA values (p < 0.05), pain intensity (p < 0.001), and worse SF-36 scores on all physical health (p < 0.05) and psychological health (only in vitality and mental health [p < 0.05]), compared to CG. CONCLUSION: Our data revealed impaired static and dynamic postural balance, and reduced quality of life in PMSG compared to CG. Postural balance impairments could explain the poor quality of life, which are likely due to the higher SA and higher pain intensity. Clinicians and physiotherapists should consider postural balance disorders while designing rehabilitation programs in these patients.

Guidelines for botulinum neurotoxin injections in piriformis syndrome.

BACKGROUND: The piriformis muscle is normally involved in piriformis syndrome and can be treated with botulinum neurotoxin using several different injection methods. However, definitive injection guidelines for the muscle have not been reported previously. AIMS: This study aimed to determine the ideal area for injections based on the intramuscular nerve distribution as obtained using a modified Sihler's staining technique. MATERIALS AND METHODS: A modified Sihler's method was applied to the piriformis muscle in 15 specimens. The intramuscular arborization areas were identified based on two anatomical landmarks: (a) the lateral border of the sacrum bone and (b) the greater trochanter. RESULTS: The nerve entry point for both piriformis muscles was found in the area between the lateral border of the sacrum and one-fifth of the distance toward the greater trochanter. The intramuscular nerve distribution for the piriformis muscle had the largest arborization patterns between one-fifth and two-fifths of the distance from the sacrum to the greater trochanter. The piriformis muscle was tendinous from two-fifths of the distance to the greater trochanter. DISCUSSION: This study has yielded suggested optimal injection locations for the piriformis muscle relative to external anatomical landmarks. CONCLUSION: Clinicians can use these guidelines to ensure the effectiveness of not only botulinum neurotoxin injections but also other agents such as steroids, anesthetics, and normal saline. These guidelines will also help to avoid adverse outcomes of injection treatments.

Pressure Pain Threshold in Subjects With Piriformis Syndrome: Test-Retest, Intrarater, and Interrater Reliability, and Minimal Detectible Changes.

OBJECTIVE: This study aimed to assess the test-retest, intrarater, and interrater reliability of using the pressure pain threshold (PPT) in healthy and affected piriformis muscles and to estimate its absolute reliability. As a secondary objective, the degree of tenderness of the affected piriformis muscles was compared with healthy piriformis muscles. STUDY DESIGN: This study used a comparative and reliability-based design. SETTING: Rehabilitation clinic. PARTICIPANTS: Patients (N=30) with unilateral piriformis muscle syndrome (30 affected and 30 healthy piriformis muscles) were recruited, and the PPT of both the healthy and affected piriformis muscles was recorded using digital algometry. Measurements of PPT were done by 2 raters (rater 1 and 2), which were selected at random order. Rater 1 repeated the PPT measurements 24-72 hours after initial assessment. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: PPT. RESULTS: Excellent intrarater intraclass correlation coefficient (ICC) values were observed for the PPT of the affected piriformis (ICC: 0.86-0.96) and the healthy piriformis (ICC: 0.88-0.96) in the same session. The PPT measurements using digital algometry showed good-to-excellent interrater reliability (ICC: 0.64-0.92) and test-retest reliability (ICC: 0.72-0.95) in both the healthy and affected piriformis muscles. The findings revealed a significant decrease in the PPT of the affected piriformis muscle in comparison to the healthy piriformis muscle (mean difference 12.76; 95% confidence interval, 15.69-9.82; P<.001). CONCLUSIONS: Digital algometry is a reliable tool for measuring piriformis PPT, regardless of the testing session and the rater. Patients with unilateral piriformis muscle syndrome have increased tenderness and decreased PPT in the affected piriformis muscle in comparison to the healthy piriformis muscle.

Case report and review of the potential role of the Type A piriformis muscle in dynamic sciatic nerve entrapment variant of piriformis syndrome.

Piriformis syndrome (PS) is an underdiagnosed but common cause of chronic buttock pain and sciatica. Anatomical variants of the piriformis muscle and sciatic nerve have not been thought to be significant in the pathophysiology of PS however, recent description of the piriformis musculotendinous junction has identified a common variant that we believe frequently results in dynamic sciatic nerve entrapment at the infra-piriformis fossa. We performed ultrasound guided low-dose Botulinum Toxin-A (BTX-A) injection to the lower piriformis muscle belly in an elite Australian Rules football player with PS and Type A piriformis muscle to relieve symptomatic sciatic nerve compression. Positive response to targeted BTX-A piriformis muscle injections support the hypothesis that sciatic nerve compression by Type A piriformis muscles may contribute to the pathophysiology of neuropathic PS, along with other functional factors. Sciatic nerve compression due to Type A piriformis at the infra-piriformis fossa has not been described previously and is a potentially common cause of neuropathic PS, especially when combined with other functional factors such as piriformis muscle spasm/hypertrophy and sacroiliac joint counternutation.

Ultrasound appears to be a reliable technique for the diagnosis of piriformis syndrome.

INTRODUCTION: Piriformis muscle syndrome (PS) is a disorder encompassing a constellation of symptoms, including buttock and hip pain. In this study we aimed to assess the value of ultrasound (US) in the diagnosis of PS. METHODS: Thirty-three clinically diagnosed PS patients and 26 healthy volunteers underwent a clinical PS scoring examination and US and MRI assessment of the bilateral piriformis muscles. The areas under the receiver operating characteristic curves (AUROCs) of the US parameters (i.e., increased thickness [iTh] and increased cross-sectional area [iCSA]) for piriformis muscle were evaluated. RESULTS: On US and MRI, the thickness and CSA were increased in PS patients. The AUROCs for the iTh and iCSA for discriminating stage 0 (healthy volunteers) from stage 1 through stage 3 (PS patients) were 0.88 and 0.95, respectively. DISCUSSION: US may be a reliable technique for the clinical diagnosis of PS. Muscle Nerve 59:411-416, 2019.

Ultrasound-guided dry needling decreases pain in patients with piriformis syndrome.

INTRODUCTION: Piriformis muscle syndrome (PMS) is a disorder that can lead to symptoms of buttock pain and limited hip-joint mobility, and may have an impact on quality of life. METHODS: Thirty-two patients with PMS were randomized to the treatment group, which included three sessions of ultrasound-guided dry needling (DN) of the piriformis muscle (n = 16), or a waitlist control group (n = 16). The primary outcome was pain intensity measured on the visual analog scale recorded at baseline and then at 72 hours and 1 week after treatment. RESULTS: At 1-week follow-up, pain intensity was significantly less in the DN group than in the waitlist control group (-2.16 [-1.01 to -3.32], P = .007) by an amount consistent with clinically meaningful improvement. DISCUSSION: The findings suggest that DN resulted in clinically meaningful short-term improvement in pain intensity of patients with PMS.

Myositis ossificans traumatica of the piriformis muscle: a rare mature case in an adult African male.

Myositis ossificans traumatica (MOT) is a common form of heterotopic ossification associated to trauma. Rare mature manifestations and topographically atypical presentations of MOT are often misdiagnosed as osteosarcoma. This case study discusses a rare, mature case of MOT of the piriformis muscle, potentially clinically associated with piriformis syndrome. The ossification was observed on a dry sacral bone of an adult skeleton belonging to a South African male during routine inventory of the Raymond A. Dart Collection of Human Skeletons, the University of the Witwatersrand, Johannesburg. The MOT was located on the anterior aspect of the sacrum at a site corresponding to the upper portion of the origin of the muscle and extended laterally towards the greater trochanter, beyond the greater sciatic notch. It was cylindrical in shape and measured approximately 52.70 mm in length and 12.10 mm in diameter. Micro-focus CT revealed an extensive and mature bony development of the piriformis muscle with distinct outer cortical and inner trabecular bone. In addition, the skeleton showed widespread healed skeletal trauma, suggesting a history of trauma. The MOT was completely fused to the sacral bone excluding the possibility of congenital anomalies. Information on the MOT of the piriformis muscle is vital to clinicians and radiographers to aid in successful diagnosis and management of the piriformis syndrome and sciatica in the gluteal region. This case also provides a rare example to biological anthropologists, paleoanthropologists and bioarchaeologists of the representation of pathologies like these on a dry bone sample.

Case report: absence of the right piriformis muscle in a woman.

We report a very rare case of a unilaterally absent piriformis muscle in a 60 year old woman. Accompanying variations comprised a common gluteal artery (instead of two distinct superior and inferior gluteal arteries), and an absent gemellus inferior muscle. The contralateral left side showed a normally developed piriformis muscle. In hominoids, the piriformis is constant, but is regularly missing in several other vertebrates. The piriformis muscle is an anatomical landmark for ultrasound investigations and ultrasound-guided interventions in the deep gluteal region such as a superior gluteal nerve block or even a sacral plexus block, also for any surgical approach such as total hip arthroplasty. A missing piriformis muscle therefore affects the orientation in the deep gluteal region and therefore the identification of the targeted structures.

Piriformis muscle syndrome: A cross-sectional imaging study in 116 patients and evaluation of therapeutic outcome.

OBJECTIVES: To increase the clinical awareness of piriformis muscle syndrome (PMs) by reporting cross-sectional imaging findings, the clinical impact of imaging studies and treatment outcome. METHODS: Within a 10-year-period, 116 patients referred for radiological evaluation of clinically suspected PMs, with excluded lumbar pathology related to symptomatology, were prospectively studied with MRI and/or computed tomography (CT). Piriformis muscle (PM), sciatic nerve (SN), piriformis region and sacroiliac joints were evaluated. PMs was categorised into primary/secondary, according to a reported classification system. Treatment decisions were recorded. Outcome was categorised using a 3-point-scale. RESULTS: Seventy-four patients (63.8%) exhibited pathologies related to PMs. Primary causes were detected in 12 and secondary in 62 patients. PM enlargement was found in 45.9% of patients, abnormal PM signal intensity/density in 40.5% and sciatic neuritis in 25.7%. Space-occupying lesions represented the most common related pathology. Treatment proved effective in 5/8 patients with primary and 34/51 patients with secondary PMs. In 34 patients, imaging revealed an unknown underlying medical condition and altered treatment planning. CONCLUSIONS: Secondary PMs aetiologies appear to prevail. In suspected PMs, PM enlargement represented the most common imaging finding and space-occupying lesions the leading cause. Imaging had the potential to alter treatment decisions. KEY POINTS: • In clinically suspected PMs cross-sectional imaging may reveal variable pathology. • Secondary PMs aetiologies appeared to be more common than primary. • PM enlargement represented the most common imaging finding in clinically suspected PMs. • Space-occupying lesions in the piriformis region represented the leading cause of PMs. • In clinically suspected PMs cross-sectional imaging may alter treatment planning.

Is it painful to be different? Sciatic nerve anatomical variants on MRI and their relationship to piriformis syndrome.

OBJECTIVES: To investigate the purported relationship between sciatic nerve variant anatomy and piriformis syndrome. METHODS: Over 49 months, 1039 consecutive noncontrast adult hip MRIs were completed for various clinical indications. Repeat and technically insufficient studies were excluded. Radiologists categorized sciatic nerve anatomy into Beaton and Anson anatomical types. Chart review using our institution's cohort search and navigation tool determined the prevalence of the explicit clinical diagnosis of piriformis syndrome (primary endpoint) and sciatica and buttock pain (secondary endpoints). A Z-test compared the prevalence of each diagnosis in the variant anatomy and normal groups. RESULTS: Seven hundred eighty-three studies were included, with sciatic nerve variants present in 150 hips (19.2%). None of the diagnoses had a statistically significant difference in prevalence between the variant and normal hip groups. Specifically, piriformis syndrome was present in 11.3% of variant hips compared with 9.0% of normal hips (p = 0.39). CONCLUSIONS: There were no significant differences in the prevalence of piriformis syndrome, buttock pain, or sciatica between normal and variant sciatic nerve anatomy. This large-scale correlative radiologic study into the relationship between sciatic nerve variants and piriformis syndrome calls into question this purported relationship. KEY POINTS: • Large retrospective study relating variant sciatic nerve anatomy, present in 19.2% of hip MRIs, and piriformis syndrome • While sciatic nerve variant anatomy has previously been implicated in piriformis syndrome in small studies, no relationship was identified between sciatic nerve variants and piriformis syndrome.

[Pathogenesis of piriformis syndrome: a magnetic resonance imaging-based comparison study].

Objective: To assess the morphological parameters of the piriformis muscle through magnetic resonance imaging(MRI) so as to further elucidate the pathogenesis of piriformis syndrome (PS). Methods: From September 2015 to October 2016, 30 suspected PS patients and 30 normal controls were enrolled in this study from the Nanfang Hospital, Southern Medical University. The possible causative factors of the PS in the patients were obtained, and the PS patients were divided into subgroups according to the anatomic site of the tender regions. The parameters of the maximum thickness (cm), area (cm(2)) and the volume (cm(3)) of the piriformis muscle of both groups were measured by MRI and were statistically compared between the groups with the independent-sample t test so as to investigate the pathogenesis of injured sciatic nerve. Results: Twenty-six patients were verified with PS, unhealthy sitting postures presented in 16 patients (61.5%) and no trauma history was recorded in these patients. Fifteen cases (57.7%) with tenderness located at the suprapiriformis foramen region (SPF group, n=15), 11 patients (42.3%) with tenderness at the piriformis muscle (PM group, n=11). The thickness, area and volume of the pathological side piriformis muscle in the PM group were all significantly higher than the corresponding indexes in the control group[(2.24±0.46) vs (1.66±0.30) cm, (14.4±2.2) vs (8.8±2.1) cm(2,) (23.9±3.8) vs (15.2±2.6) cm(3,) respectively, t=4.699, 7.437, 8.291, all P<0.05]and were all higher remarkably than those in the SPF group[(1.62±0.20) cm, (8.7±1.6) cm(2,) (14.1±4.8) cm(3,) respectively, t=4.640, 7.631, 5.589, all P<0.05]. No significant difference was observed in the up-mentioned indexes between the SPF and the control group (t=-0.439, -0.102, -1.083, all P>0.05). Conclusions: Tender region at the buttock indicates the lesion site in the PS patients. The PS patients with tenderness at the suprapiriformis region might originate from another pathogenesis independent of piriformis muscle compression, the injury of the sciatic nerve or its branch maybe due to the indirect crush by the soft tissue of the suprapiriformis region under an unhealthy sitting posture.

Piriformis muscle syndrome with assessment of sciatic nerve using diffusion tensor imaging and tractography: a case report.

Piriformis muscle syndrome (PMS) is difficult to diagnose by objective evaluation of sciatic nerve injury. Here we report a case of PMS diagnosed by diffusion tensor imaging (DTI) and tractography of the sciatic nerve, which can assess and visualize the extent of nerve injury. The patient was a 53-year-old man with a 2-year history of continuous pain and numbness in the left leg. His symptoms worsened when sitting. Physical examination, including sensorimotor neurologic tests, the deep tendon reflex test, and the straight leg raise test, revealed no specific findings. The hip flexion adduction and internal rotation test and resisted contraction maneuvers for the piriformis muscle were positive. There were no abnormal findings on magnetic resonance imaging (MRI) of the lumbar spine. The transverse diameter of piriformis muscle was slightly thicker in affected side on MRI of the pelvis. A single DTI sequence was performed during MRI of the pelvis. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve were quantified at three levels using the fiber-tracking method. FA values were significantly lower and ADC values were significantly higher distal to the piriformis muscle. We performed endoscopic-assisted resection of the piriformis tendon. Intraoperatively, the motor-evoked potentials in the left gastrocnemius were improved by resection of the piriformis tendon. The patient's symptoms improved immediately after surgery. There was no significant difference in FA or ADC at any level between the affected side and the unaffected side 3 months postoperatively. MRI-DTI may aid the diagnosis of PMS.

Diffusion tensor imaging and tractography of the sciatic nerve: assessment of fractional anisotropy and apparent diffusion coefficient values relative to the piriformis muscle, a preliminary study.

OBJECTIVE: Piriformis muscle syndrome (PMS) is underdiagnosed. To evaluate the potential of diffusion tensor imaging and diffusion tensor tractography as innovative tools for the diagnosis of PMS by functional assessment of the sciatic nerve, the aims of this study are to assess the reproducibility and to evaluate the changes in the parameters at levels proximal and distal to the piriformis. MATERIALS AND METHODS: Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve at three levels were quantified twice each by two examiners using the fiber-tracking method. In the first part of the study, laterality and reproducibility were evaluated using intraclass correlation coefficients (ICC) in ten healthy volunteers. In the second part of the study, the healthy side and symptomatic side were assessed in ten consecutive patients with sciatica. There were three patients with no findings on lumbar magnetic resonance imaging (MRI). RESULTS: There was no laterality in either FA or ADC values in asymptomatic patients at any level. The mean intra-rater ICC was 0.90 and the mean inter-rater ICC was 0.87. FA was significantly lower and ADC significantly higher on the symptomatic side at each level in patients with sciatica. In the three sciatica patients with no findings on lumbar MRI, FA was significantly lower and ADC was significantly higher only at levels distal to the piriformis. These patients experienced full pain relief after ultrasound-guided injection of local anesthesia. CONCLUSIONS: Diffusion tensor imaging and diffusion tensor tractography might be innovative tools for the diagnosis of PMS.

The sciatic nerve in human cadavers - high division or low formation?

Variations of the sciatic nerve have been extensively studied in the past including its relationship with the piriformis muscle and associated clinical conditions like piriformis syndrome and sciatica. In the present study we noticed some interesting variations of the sciatic nerve, which were slightly different from the cases described earlier. In the previous studies most of the authors described the higher division of sciatic nerve and none of them discussed its formation. In this study we tried to look its formation from the sacral plexus and its divisions in the thigh. We noticed that in one cadaver the two components of the sciatic nerve originated directly from the sacral plexus and coursed down without merging in the thigh. Should this be called a higher division or non formation of the sciatic nerve? On the other hand in two other cadavers, the two divisions after emerging separately from the sacral plexus, united in the gluteal region and in the thigh respectively. Should we call this as higher division or low formation of the sciatic nerve? In two other cadavers the sciatic nerve emerged from the greater sciatic foramen below the piriformis and divided in the gluteal region itself. Ideally this should be called as higher division of sciatic nerve.

Atypical lipoma of the right piriformis muscle: a case report and review of the literature.

BACKGROUND: Piriformis muscle mass is rare, which is particular for intrapiriformis lipoma. Thus far, only 11 cases of piriformis muscle mass have been reported in the English literature. Herein, we encountered one patient with intrapiriformis lipoma who was initially misdiagnosed. CASE PRESENTATION: The patient is a 50-year-old Chinese man. He complained of osphyalgia, right buttock pain, and radiating pain from the right buttock to the back of the right leg. Both ultrasound and magnetic resonance imaging demonstrated a cyst-like mass in the right piriformis muscle. Ultrasonography-guided aspiration was performed on this patient first, but failed. He was then recommended to undergo mass resection and neurolysis of sciatic nerve. Surprisingly, final histology revealed the diagnosis of intrapiriformis lipoma. The patient exhibited significant relief of symptoms 3 days post-surgery. CONCLUSION: Diagnosis and differential diagnosis of radicular pain are potentially challenging but necessary. Atypical lipoma is prone to be misdiagnosed, especially in rare sites. It is notable for clinicians to be aware of the presence of intrapiriformis lipoma to avoid misdiagnosis and inappropriate treatment.

Could dry needling change the kinematics of gait in individuals with piriformis muscle syndromes? Secondary analysis of a randomized controlled trial.

INTRODUCTION: Piriformis muscle syndrome (PMS) is a condition that can lead to symptoms including gluteal pain, local tenderness, and limitation of hip joint motion in daily activities, and it may have a major impact on some daily functions such as gait. We proposed that dry needling (DN) can improve the gait of individuals with PMS. METHODS: Thirty-two individuals with PMS were assigned equally and randomly to the treatment group or the wait-list control group. Subjects in the treatment group received three sessions of DN of the piriformis muscle. All participants in both groups were educated to correct their lifestyles. The outcome measures were the gait-related parameters (walking speed, peak hip flexion, peak hip extension, time to peak internal and external hip rotation, and knee sagittal range of motion), which were evaluated at baseline and after treatment. To compare different outcomes, analysis of covariance (ANCOVA) was used, with baseline as the covariance and groups as a factor. RESULT: After DN sessions, peak hip extension during gait showed a statistically significant difference [adjusted MD 1.9 (3.7-0.08), p < 0.05, d = 0.56 (0.1-1.28)] in favor of the DN group. Peak hip flexion, on the other hand, exhibited a marginal statistically significant difference [adjusted MD -3.2 (-6.51 to 0.01), p = 0.053, d = 0.44 (1.16 to -0.02)] compared to the control group. CONCLUSION: The findings suggest that participants in DN showed significantly greater peak extension angle of the hip during walking in individuals with PMS than in the control group.

Piriformis syndrome as an overlooked cause of pain in a patient with axial spondyloarthritis: a case report.

Piriformis syndrome is a neuromuscular disorder characterized by hip, buttock, and leg pain. Axial spondyloarthritis is a rheumatic disease primarily affecting the sacroiliac joint and the spine. Due to their anatomical proximity, the potential relationship between piriformis syndrome and sacroiliitis has been discussed for some time. However, literature review revealed that there is no study on piriformis syndrome in individuals with axial spondyloarthritis. Here, we present the case of a 30-year-old female with axial spondyloarthritis who developed severe low back, hip, and buttock pain that persisted despite initial treatment for axial spondyloarthritis. We first re-evaluated her condition through physical examination, magnetic resonance imaging, and an injection test for piriformis syndrome. Following a comprehensive assessment, the patient was diagnosed with both axial spondyloarthritis and piriformis syndrome. Subsequently, a tailored treatment plan was devised, addressing both conditions, and after a 3-month course of treatment, we obtained significant reduction in pain of the patient. This is the first case report in literature, where we used injection test to confirm the diagnosis of the piriformis syndrome in a patient with axial spondyloarthritis. We therefore strongly advocate considering piriformis syndrome as a potential etiology for pain in individuals with axial spondyloarthritis consistently. This recognition is important as piriformis syndrome does not respond adequately to non-steroidal anti-inflammatory drugs and may lead to unnecessary use of biological disease-modifying antirheumatic drugs. Timely identification and intervention are imperative in ensuring optimal patient care.