Fatty muscle infiltration of the hip lateral rotator muscles following direct anterior minimally invasive total hip arthroplasty

Gluteal muscle fatty infiltration, fall risk, and mobility limitation in older women with urinary incontinence: a pilot study

OBJECTIVE

Gluteal muscle quality influences risk of falling and mobility limitation. We sought (1) to compare gluteal muscle fatty infiltration (FI) between groups of older women with urinary incontinence (UI) at risk for falling (at-risk group) and not at risk for falling (not-at-risk group), and (2) to determine correlation of gluteal FI with Timed Up and Go (TUG) and Short Physical Performance Battery (SPPB) performance.

MATERIALS AND METHODS

Prospective pilot study of gluteal FI on pelvis MRI for 19 women with UI, aged ≥ 70 years. A musculoskeletal radiologist selected axial T1-weighted MR images; then, two blinded medical student research assistants analyzed gluteal FI by quantitative fuzzy C-means segmentation. TUG and SPPB tests were performed. TUG ≥ 12 s defined participants as at risk for falling. Descriptive, correlation, and reliability analyses were performed.

RESULTS

Mean age, 76.3 ± 4.8 years; no difference for age or body mass index (BMI) between the at-risk (n = 5) versus not-at-risk (n = 14) groups. SPPB score (p = 0.013) was lower for the at-risk group (6.4 ± 3.1) than for the not-at-risk group (10.2 ± 1.9). Fuzzy C-means FI-%-estimate differed between the at-risk group and the not-at-risk group for bilateral gluteus medius/minimus (33.2% ± 15.6% versus 19.5% ± 4.1%, p = 0.037) and bilateral gluteus maximus (33.6% ± 15.6% versus 19.7% ± 6.9%, p = 0.047). Fuzzy C-means FI-%-estimate for bilateral gluteus maximus had significant (p < 0.050) moderate correlation with age (rho =  - 0.64), BMI (rho = 0.65), and TUG performance (rho = 0.52). Fuzzy C-means FI-%-estimates showed excellent inter-observer and intra-observer reliability (intraclass correlation coefficient, ≥ 0.892).

CONCLUSION

Older women with UI at risk for falling have greater levels of gluteal FI and mobility limitation as compared to those not at risk for falling.

Quantitative gait analysis after total hip arthroplasty through a minimally invasive direct anterior approach: A case control study

INTRODUCTION

Total Hip Arthroplasty (THA) leads to excellent clinical and functional results. The Minimally Invasive Anterior Approach (MIAA) theoretically allows rapid recovery and a reduction in the need for rehabilitation, but alterations in muscle and static balance have previously been demonstrated. Kinetic, kinematic and muscular alterations have been shown to persist up to 1year postoperatively but data beyond 1year postoperatively is lacking. Thus, the objective of this study was to compare the data from Quantitative Gait Analysis (QGA) coupled with electromyography (EMG), of patients one year postoperatively with THA through MIAA, compared to an asymptomatic control group.

HYPOTHESIS

We hypothesized that QGA and EMG parameters would not normalize beyond one year postoperatively.

PATIENTS AND METHODS

Twenty-seven patients were recruited, including 15 subjects (64.6±6.6years) operated on by MIAA, who at 15.9±3.1months postoperatively, along with 12 asymptomatic control subjects (68.9±9.7years), who underwent QGA and maximal isometric muscle strength tests, coupled with EMG on the gluteus medius and maximus, Tensor Fascia Lata (TFL) and Sartorius muscles. The spatiotemporal parameters of walking (step length, walking speed, cadence, single leg support time), kinetics (vertical ground reaction forces, hip moments in the 3 planes) and kinematics (coxofemoral and pelvic amplitudes) were analyzed.

RESULTS

The walking speed was lower on the non-operated side of the experimental subjects (0.96ms^-1 compared to 1.13ms^-1 for asymptomatic [p=0.018]), as was the step length on the operated side (0.53m compared to 0.60m for asymptomatic [p=0.042]). Maximal isometric muscle strength was lower in subjects operated on for the gluteus maximus and medius (p=0.004), compared to asymptomatic subjects. Moments were lower in the subjects operated on in extension (0.72Nm on the operated side, 0.75Nm on the non-operated side compared to 1.06Nm for asymptomatic [p=0.007 and p=0.024]) and lateral rotation (0.09Nm on the operated side, 0.05Nm on the non-operated side compared to 0.16Nm for asymptomatic subjects [p=0.009 and p=0.0005]). Hip adduction amplitudes were lower on the operated side compared to asymptomatic subjects (3.93° versus 9.14° for asymptomatic [p=0.005]). Pelvic amplitudes in the frontal plane were lower amongst operated subjects (0.44° against 1.97° for asymptomatic [p=0.041]). Pelvic amplitudes in the sagittal plane were higher in the operated subjects (15.74° on the operated side, 15.43° on the non-operated side compared to 9.65° for asymptomatic [p=0.041 and p=0.032]).

DISCUSSION

Our initial hypothesis was validated, since walking deficits persisted beyond one year postoperatively after THA through MIAA. A decrease in maximal isometric muscle strength of the gluteus medius and gluteus maximus was observed, as well as an alteration of kinetic and kinematic parameters in the sagittal and frontal planes. The results were in agreement with the literature and reflected the establishment of compensatory mechanisms to overcome alterations in joint strength and range more than one year postoperatively. These results would allow rehabilitation programs to be more specific and would justify a study on the other approaches for THA.

LEVEL OF EVIDENCE

III; non-randomized control trial.

MRI assessment of minimally invasive anterolateral approaches in total hip arthroplasty

INTRODUCTION

Total hip arthroplasty (THA) on a minimally invasive anterolateral (MIAL) approach frequently leads to gluteus minimus and gluteus medius lesions, and sometimes to tensor fasciae latae (TFL) denervation. We therefore developed compensatory strategies, which we assessed on pre- and post-operative MRI: 1) to assess gluteus minimus and gluteus medius fatty infiltration (FI), 2) to assess TFL FI, and 3) to assess FI in the other periarticular muscles.

HYPOTHESIS

The modified MIAL approach reduces the rate of gluteus minimus and gluteus medius lesion.

MATERIALS AND METHODS

A continuous prospective single-surgeon series of THA using a MIAL approach included 25 patients. Femoral implantation was performed with the hip in extension so as to distance the proximal femur from the gluteals, avoiding muscle trauma. The superior gluteal nerve branch in the space between the gluteus medius and TFL, running toward the TFL, was systematically released and protected. MRI was performed preoperatively and at 3 months and 1 year post-surgery. FI was analyzed according to the Goutallier classification in all periarticular muscles.

RESULTS

One patient lacked preoperative MRI and was excluded, leaving 24 patients, for 72 MRIs. In 10/24 patients (41.7%) the gluteus minimus and in 8/24 patients (33.3%) the anterior third of the gluteus medius showed ≥2 grade increase in FI between preoperative and 1-year MRI, with significant increases in both at 3 months (p<0.001) and 1 year (p<0.001). At least a 2 grade increase in FI at 1 year was seen in 1 patient (4.2%) in the TFL, in 2 (8.3%) in the piriformis, and in 1 (4.2%) in the obturator internus. There were no significant differences in FI between preoperative, 3-month or 1-year MRI in any other periarticular muscles.

CONCLUSION

Femoral implantation in hip extension did not reduce the rate of gluteal lesions, which remained frequent. In contrast, release of the superior gluteal nerve branch could be effective in conserving TFL innervation. Some rare lesions of the proximal part of the pelvi-trochanteric muscles were also observed.

LEVEL OF EVIDENCE

IV, Prospective case series.

Comparative MRI assessment of three minimally invasive approaches in total hip arthroplasty

INTRODUCTION

Minimally invasive approaches (direct anterior approach: DAA; minimally invasive anterolateral: MIAL; piriformis-sparing posterior approach: PSPA) are widely used for total hip arthroplasty (THA), with a muscle-sparing objective. There are no published comparative studies of muscle damage secondary to these approaches. The aim of the present study was to compare fatty infiltration (FI) on MRI induced by DAA, MIAL and PSPA in THA 1) in the tensor fasciae latae (TFL) and sartorius muscles, 2) in the gluteal muscles, and 3) in the pelvitrochanteric muscles.

HYPOTHESIS

Greater FI is induced by DAA in anterior muscles, by MIAL in gluteal muscles and by PSPA in pelvitrochanteric muscles.

MATERIALS AND METHODS

Three continuous prospective series of THA by DAA, MIAL and PSPA included 25 patients each. MRI was performed preoperatively and at 1 year postoperatively. FI was graded on the Goutallier classification in all periarticular hip muscles. Muscles showing ≥2 grade aggravation at 1 year were considered damaged.

RESULTS

Nine patients whose preoperative MRI was uninterpretable were excluded. In all, 66 patients (21 DAA, 24 MIAL and 21 PSPA) with 132 MRI scans were analyzed. TFL was damaged in 2/21 DAA patients (9.5%), 1/24 MIAL patients (4.2%) and 0/21 PSPA patients (0%). There were no sartorius lesions. The anterior third of the gluteus medius was damaged in 8/24 MIAL patients (33.3%) and the gluteus minimus in 10/24 (41.7%), compared to 1/21 DAA patients (4.8%) and 0/21 PSPA patients (0%). The mid and posterior thirds of the gluteus medius and the gluteus maximus were never damaged. The piriformis muscle was damaged in 3/21 DAA patients (14.3%), 2/24 MIAL patients (8.3%) and 2/21 PSPA patients (9.5%). The obturator internus was damaged in 4/21 DAA patients (19%), 1/24 MIAL patients (4.2%) and 16/21 PSPA patients (76.2%). The obturator externus and quadratus femoris were mainly damaged in PSPA patients: respectively, 5/21 (23.8%) and 4/21 patients (19%)).

CONCLUSION

The muscle-sparing properties of minimally invasive hip approaches are only theoretical. In the present series, there were rare TFL lesions with DAA and MIAL. Gluteus medius and minimus lesions were frequent in MIAL. Pelvitrochanteric muscles lesions were more frequent in PSPA, but found in all 3 approaches. These findings should help guide surgeons in their choice of approach and in informing patients about the damage these minimally invasive approaches can cause.

LEVEL OF EVIDENCE

III, prospective comparative study.

MRI assessment of piriformis-sparing posterior approach in total hip arthroplasty

INTRODUCTION

In total hip arthroplasty (THA), the posterior approach is the most common throughout the world. Dislocation is one of the main complications incurred, but the risk may be reduced by sparing posterior structures. Thus, piriformis-sparing posterior approaches (PSPA) were described, and satisfactory conservation of the muscle was reported. On the other hand, a recent cadaver study reported occult intrapelvic piriformis lesions in 91% of cases. In the light of this discordance, we performed pre- and postoperative MRI in THA by PSPA: 1) to assess the fatty infiltration of the piriformis induced by the approach, with particular attention to intrapelvic lesions; and 2) to assess fatty infiltration of the other periarticular muscles.

HYPOTHESIS

The piriformis muscle will show little fatty infiltration following PSPA.

MATERIALS AND METHODS

A continuous prospective single-surgeon series of THA by PSPA included 25 patients. MRI was performed preoperatively and at 3 months and 1 year postoperatively. Fatty infiltration was assessed on the Goutallier classification in all periarticular muscles.

RESULTS

Preoperative MRI was lacking in 4 patients, who were excluded from analysis; 21 patients with MRI were thus analyzed. In the piriformis muscle, there was no significant change in fatty infiltration between preoperative and 3-month (p=0.29) or 1-year (p=0.41) MRI. Two of the 21 patients (9.5%) showed grade 3 or 4 fatty infiltration at 1 year, compared to 0/21 (0%) preoperatively; both showed sacral avulsion of the piriformis. Significant differences between preoperative and 1-year MRI were found for the obturator internus and externus, with grade 3 or 4 infiltration at 1 year in 14 cases for the obturator internus (14/21: 66.7%), in 3/21 for the obturator externus (14.3%) and in 6/21 for the quadratus femoris (28.6%), compared to respectively 0/21 (0%), 0/21 (0%) and 3/21 (14.3%) preoperatively. There were no significant differences for any of the other periarticular muscles.

CONCLUSION

PSPA in THA ensured good conservation of the piriformis. There may, however, be rare and irreversible sacral lesions invisible intraoperatively.

LEVEL OF EVIDENCE

IV; prospective case series.