Strain Assessment of Deep Fascia of the Thigh During Leg Movement: An in situ Study

Harvest of large fascia lata autograft: Outcomes in 108 patients

PURPOSE

Due to the reclassification of transvaginal mesh as a high-risk device, there has been renewed interest in the use of fascia lata in pelvic floor reconstruction. Here we report our experience in 108 patients who underwent large fascia lata harvest for pelvic organ prolapse (POP) repair. Our primary objective was to highlight the postoperative morbidity of the large fascia lata harvest in patients who underwent POP repair using fascia lata autograft.

METHODS

Surgery involved harvesting a fascia lata graft through a small lateral upper thigh incision and was used for either autologous transvaginal POP repair or autologous sacrocolpopexy. To prevent seroma, a temporary Jackson-Pratt drain was intraoperatively placed and a mild compression wrap was applied to the area for 4-6 weeks postoperatively. Patient demographics were obtained preoperatively, while physical exam findings and postoperative outcomes related to the fascia lata harvest were collected at sequential follow up visits.

RESULTS

One-hundred eight patients underwent 111 large fascia lata harvests for either transvaginal or abdominal/robotic POP repair from July 2016 to January 2022. Mean follow-up was 19.6 months (range: 1-65) with 38 patients having 24 months or more of follow-up. Mean Visual Analog Pain (VAP) score was 1 (range: 0-10). Sixteen patients developed asymptomatic thigh bulges, 16 patients developed harvest site seromas (of which 14 resolved), and 59 patients experienced mild, non-bothersome paresthesia near the incision.

CONCLUSION

Large fascia lata harvest offers a robust autograft for transvaginal or transabdominal POP repair with minimal morbidity. Harvest site complications are minor and typically resolve with expectant management. This technique can be safely utilized in patients who desire graft-augmented repair of POP without the use of synthetic mesh, allograft, or xenograft.

First-in-human demonstration of floating EMG sensors and stimulators wirelessly powered and operated by volume conduction

BACKGROUND

Recently we reported the design and evaluation of floating semi-implantable devices that receive power from and bidirectionally communicate with an external system using coupling by volume conduction. The approach, of which the semi-implantable devices are proof-of-concept prototypes, may overcome some limitations presented by existing neuroprostheses, especially those related to implant size and deployment, as the implants avoid bulky components and can be developed as threadlike devices. Here, it is reported the first-in-human acute demonstration of these devices for electromyography (EMG) sensing and electrical stimulation.

METHODS

A proof-of-concept device, consisting of implantable thin-film electrodes and a nonimplantable miniature electronic circuit connected to them, was deployed in the upper or lower limb of six healthy participants. Two external electrodes were strapped around the limb and were connected to the external system which delivered high frequency current bursts. Within these bursts, 13 commands were modulated to communicate with the implant.

RESULTS

Four devices were deployed in the biceps brachii and the gastrocnemius medialis muscles, and the external system was able to power and communicate with them. Limitations regarding insertion and communication speed are reported. Sensing and stimulation parameters were configured from the external system. In one participant, electrical stimulation and EMG acquisition assays were performed, demonstrating the feasibility of the approach to power and communicate with the floating device.

CONCLUSIONS

This is the first-in-human demonstration of EMG sensors and electrical stimulators powered and operated by volume conduction. These proof-of-concept devices can be miniaturized using current microelectronic technologies, enabling fully implantable networked neuroprosthetics.

Stretch tolerance and elastic passive reaction of the quadriceps femoris seem to depend more on the fascia profundis taut surfaces than on the underlying stretched muscle

The rectus femoris and its covering, the fascia lata (i.e., fascia profundis), are two anatomical structures involved in anterior thigh stretching. This study aimed to identify the role of strain changes in the fascia lata in limiting stretch tolerance. The reaction force intensity of 11 men and 5 women was assessed during passive stretching of the anterior thigh at 130, 110, 90, and 70° of knee flexion. Recent data suggest that the fascia lata strain field is modified with knee flexion. Therefore, the relationship between knee flexion angle and stretch tolerance was assessed. We found that the reaction force of the anterior thigh increased almost linearly with the degree of knee extension between 130° and 70°. The fascia lata stretched surface proprioceptive information seems responsible for stretch tolerance. Fascia profundis strain field must be considered during stretching experiments.

Donor-Site Morbidity After Autologous Fascia Lata Harvest for Arthroscopic Superior Capsular Reconstruction: A Midterm Follow-up Evaluation

Background:

Autologous fascia lata (AFL) graft use in arthroscopic superior capsular reconstruction (ASCR) is effective for the treatment of irreparable rotator cuff tears (RCTs). Although donor-site morbidity (DSM) is a recurrent argument against AFL graft use, scientific evidence for this argument is lacking.

Purpose:

To report the midterm clinical follow-up evaluation of DSM in ASCR using minimally invasively harvested AFL grafts and compare thigh function and patient satisfaction with those of an unharvested control group.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Of 66 consecutive patients who underwent ASCR using a minimally invasively harvested AFL graft, 39 patients with a minimum follow-up of 24 months were retrospectively evaluated (ASCR group) and compared with 39 randomly selected patients who underwent arthroscopic RCT repair by the same surgeons (control group). The functional outcomes of both thighs were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Patient satisfaction was evaluated using the Patient Scar Assessment Questionnaire (PSAQ) and a subjective questionnaire. Pain was quantified using a visual analog scale (VAS).

Results:

The ASCR group had a mean age of 65 years (range, 51-77 years) and a mean follow-up of 47 months (range, 24-66 months). The WOMAC score in the harvested thigh differed by 0.8% from that in the contralateral thigh ( P = .002). The mean PSAQ score differed by 6 points from the minimum PSAQ score ( P < .001). Overall, 95% of the patients indicated that they would undergo the same surgery again and that the shoulder outcome compensated for the thigh symptoms. There was no significant association between the presence of residual thigh symptoms and the willingness to undergo the same surgery again ( P = .354). The mean VAS score in the harvested thigh was 0.6 (range, 0-5). There was no significant difference in the average WOMAC score or VAS score between groups ( P = .684 and P = .148, respectively).

Conclusion:

Despite the proportion of residual symptoms, the associated functional effects were small and not clinically significant, and the vast majority of patients were accepting of the harvest symptoms given the improvement in shoulder function.