Age-related Changes in Maximum Pelvic Anteversion and Retroversion Angles Measured in the Sitting Position

Screw penetration of the iliopsoas muscle causing late-onset pain after total hip arthroplasty: A case report

BACKGROUND

Postoperative pain following total hip arthroplasty (THA) may occur in a few patients but may pose a significant challenge to surgeons if the etiology is not identified. Herein, we report the case of a patient who developed late-onset pain following THA due to screw penetration of the iliopsoas tendon.

CASE SUMMARY

We report the case of a 77-year-old man who developed inguinal pain 7 years after THA. While the symptoms resembled that of iliopsoas impingement by the acetabular cup, the pain resolved only when the supplementary acetabular screw protruding through the ilium was decompressed. Decompression was performed using the pararectus approach. The patient was able to ambulate pain-free immediately after surgery.

CONCLUSION

A protruded screw through the ilium may penetrate the iliopsoas muscle, causing pain following THA. Pain may resolve with the decompression of the protruded screw.

Influence of pelvic inclination on sit to stand task in stroke patients

Background

Stroke results in an impaired sit to stand (STS) task. Pelvic movements are essential in daily living activities. Few studies investigated the effect of spine and pelvis separately on functional activities in stroke patients.

Objective

The study aimed to assess the angles of pelvic inclination (anterior and posterior pelvic tilt angles) (APT and PPT) during sitting position and during STS movement. It aimed also to determine the influence of sagittal pelvic tilt angles on STS performance in stroke patients.

Patients and methods

Thirty male hemi-paretic stroke patients (GI) and 15 matched healthy volunteer subjects (GII) represented the sample of this study. Stroke patients were assigned into two equal groups (group Ia and Ib). Sagittal pelvic tilt angles were measured by using the palpation meter inclinometer during sitting position and during initiation and mid of STS by using two dimensional (2D) video-based motion analysis system. Time of five repetitions STS test was used to assess the ability to perform STS task.

Results

The results showed a significant increase of PPT angle during static sitting, a significant decrease in APT angle during initiation and mid of STS task and a significant increase in time taken for five repetitions STS test in both stroke groups (P < 0.05).

Conclusion

Abnormal pelvic alignment and movements affect the functional performance of stroke patients during sitting and sit to stand task.

Trial registration

NCT03053154. Registered January 22, 2017. Retrospectively registered.

How much does lumbar fusion change sagittal pelvic tilt in individuals receiving total hip arthroplasty?

Background

This study primarily aims to examine the effect of lumbar fusion on changes in sagittal pelvic tilt (SPT) in total hip arthroplasty (THA) patients.

Methods

We reviewed 19 hip osteoarthritic patients undergoing THA with or without lumbar fusion. The gender, age, primary disease, Deyo comorbidity score, and year of surgery were sorted and matched. All patients were followed up for at least 12 months. They were compared in terms of the SPT angle, Harris hip score (HHS) and complications.

Results

On average, the patients receiving lumbar fusion had a − 3.9 (95% CI − 7.7 to − 1.5) degrees of SPT before THA and − 2.7 (95% CI − 6.5 to 1.1) degrees postoperatively, and the THA patients without lumbar fusion averaged 2.5 (95% CI − 0.1 to 5.0) degrees and 4.2 (95% CI 2.0 to 6.4) degrees, respectively. In the lumbar fusion patients, the mean SPT was − 3.9 (95% CI − 9.9 to 2.0) degrees with L5S1 fusion and − 4.0(95% CI − 10.0 to 2.1) degrees without L5S1 fusion on the standing radiograph before THA (t = 0.01, P = 0.99). The mean SPT was − 1.2 (95% CI − 4.9 to 2.6) degrees with one- and two-segment fusion and − 10.0 (95% CI − 18.5 to 1.5) degrees with three- and four-segment fusion before THA (t = 2.60, P = 0.02). There was no statistically significant difference in cup inclination and cup anteversion after THA between the lumbar fusion and control groups. These patients in the two groups achieved a similar HHS 12 months after THA despite the fact that they had different SPT and HHS before THA.

Conclusion

Lumbar fusion appears to increase the posterior SPT by approximately 6 degrees in the patients undergoing THA. Lumbar fusion of more than two segments is a predictor of more posterior SPT changes, but fusion of L5S1 is not.

Pelvic retroversion: a compensatory mechanism for lumbar stenosis

OBJECTIVE

The flexed posture of the proximal (L1–3) or distal (L4–S1) lumbar spine increases the diameter of the spinal canal and neuroforamina and can relieve symptoms of neurogenic claudication. Distal lumbar flexion can result in pelvic retroversion; therefore, in cases of flexible sagittal imbalance, pelvic retroversion may be compensatory for lumbar stenosis and not solely compensatory for the sagittal imbalance as previously thought. The authors investigate underlying causes for pelvic retroversion in patients with flexible sagittal imbalance.

METHODS

One hundred thirty-eight patients with sagittal imbalance who underwent a total of 148 fusion procedures of the thoracolumbar spine were identified from a prospective clinical database. Radiographic parameters were obtained from images preoperatively, intraoperatively, and at 6-month and 2-year follow-up. A cohort of 24 patients with flexible sagittal imbalance was identified and individually matched with a control cohort of 23 patients with fixed deformities. Flexible deformities were defined as a 10° change in lumbar lordosis between weight-bearing and non–weight-bearing images. Pelvic retroversion was quantified as the ratio of pelvic tilt (PT) to pelvic incidence (PI).

RESULTS

The average difference between lumbar lordosis on supine MR images and standing radiographs was 15° in the flexible cohort. Sixty-eight percent of the patients in the flexible cohort were diagnosed preoperatively with lumbar stenosis compared with only 22% in the fixed sagittal imbalance cohort (p = 0.0032). There was no difference between the flexible and fixed cohorts with regard to C-2 sagittal vertical axis (SVA) (p = 0.95) or C-7 SVA (p = 0.43). When assessing for postural compensation by pelvic retroversion in the stenotic patients and nonstenotic patients, the PT/PI ratio was found to be significantly greater in the patients with stenosis (p = 0.019).

CONCLUSIONS

For flexible sagittal imbalance, preoperative attention should be given to the root cause of the sagittal misalignment, which could be compensation for lumbar stenosis. Pelvic retroversion can be compensatory for both the lumbar stenosis as well as for sagittal imbalance.

Relationship between the ability to perform the sit-to-stand movement and the maximum pelvic anteversion and retroversion angles in patients with stroke

[Purpose] The purpose of this study was to investigate the relationship between the ability to perform the sit-to-stand movement and the maximum pelvic anteversion and retroversion angles of patients. [Subjects] Thirty-two stroke patients (66.7±7.6 years) (>3 months post-stroke) who were able to sit unsupported and 50 age-matched healthy subjects participated in this study. The stroke patients were classified into two groups according to the sit-to-stand movement test: the group that was able to stand up (the stand-able group) (18 persons) and the group that was unable to stand up (the stand-unable group) (14 persons). [Methods] Pelvic anteversion and retroversion maximum angles were measured by a manual goniometer attached to an inclinometer. [Results] The maximum pelvic anteversion angles were −1.6 ± 5.0°, 1.2 ± 2.8°, and −12.4 ± 6.1° in the control group, the stand-able stroke group, and the stand-unable stroke group, respectively. A significant main effect of group was found. An angle discriminating between the two stroke groups was found: the maximum anteversion angles in the stand-able group were distributed above −5°. [Conclusion] The maximum pelvic anteversion angle was significantly smaller in the stand-unable group than in the stand-able and control groups.