Targeted muscle reinnervation following external hemipelvectomy or hip disarticulation: An anatomic description of technique and clinical case correlates

BACKGROUND

Targeted muscle reinnervation (TMR) has been shown to decrease or prevent neuropathic pain, including phantom and residual limb pain, after extremity amputation. Currently, a paucity of data and lack of anatomical description exists regarding TMR in the setting of hemipelvectomy and/or hip disarticulations. We elaborate on the technique of TMR, illustrated through cadaveric and clinical correlates.

METHODS

Cadaveric dissections of multiple transpelvic exposures were performed. The major mixed motor and sensory nerve branches were identified, dissected, and tagged. Amputated peripheral nerves were transferred to identified, labeled target motor nerves via direct end-to-end nerve coaptations per traditional TMR technique. A retrospective review was completed by our multi-institutional teams to include examples of clinical correlates for TMR performed in the setting of hemipelvectomies and hip disarticulations.

RESULTS

A total of 12 TMR hemipelvectomy/hip disarticulation cases were performed over a 2 to 3-year period (2018-2020). Of these 12 cases, 9 were oncologic in nature, 2 were secondary to traumatic injury, and 1 was a failed limb salvage in the setting of chronic refractory osteomyelitis of the femoral shaft.

CONCLUSIONS

This manuscript outlines the technical considerations for TMR in the setting of hemipelvectomy and hip disarticulation with supporting clinical case correlates.

Preserving the Knee in the Setting of High Segmental Tibial Bone and Massive Soft-Tissue Loss Using Vascularized Distal Tibial Bone Docking and a Foot Fillet Flap: A Case Report

CASE

We discuss our reconstructive approach to avoid an above-knee amputation in a 33-year-old man presenting after lower extremity crush injury. We used a vascularized tibial bone flap and a foot fillet flap to restore length and joint functionality to the residual limb. The patient ambulates with good prosthetic fit on durable heel pad skin and 100° active knee motion.

CONCLUSION

This pairing of intramedullary nail with vascularized bone flap and fillet flap to address soft-tissue coverage and retain limb length is a useful tool in traumatic lower extremity injury management, providing an alternative technique for tibial bone graft stabilization with robust, sensate tissue coverage.

A biomechanical cadaver comparison of suture button fixation to plate fixation for pubic symphysis diastasis

OBJECTIVES

To determine whether suture button fixation of the pubic symphysis is biomechanically similar to plate fixation in the treatment of partially stable pelvic ring injuries.

METHODS

Twelve pelvis specimens were harvested from fresh frozen cadavers. Dual-x-ray-absorptiometry (DXA) scans were obtained for all specimens. The pubic symphysis of each specimen was sectioned to simulate a partially stable pelvic ring injury. Six of the pelvises were instrumented using a 6 hole, 3.5 mm low profile pelvis plate and six of the pelvises were instrumented with two suture button devices. Biomechanical testing was performed on a pneumatic testing apparatus in a manner that simulates vertical stance. Displacement measurements of the superior, middle, and inferior pubic symphysis were obtained prior to loading, after an initial 440 N load, and after 30,000 and 60,000 rounds of cyclic loading. Statistical analysis was performed using Wilcoxon-Mann-Whitney tests, Fisher's exact test, and Cohen's d to calculate effect size. Significance was set at p < 0.05.

RESULTS

There was no difference between groups for DXA T scores (p = 0.749). Between group differences in clinical load to failure (p = 0.65) and ultimate load to failure (p = 0.52) were not statistically significant. For symphysis displacement, the change in fixation strength and displacement with progressive cyclic loading was not significant when comparing fixation types (superior: p = 0.174; middle: p = 0.382; inferior: p = 0.120).

CONCLUSION

Suture button fixation of the pubic symphysis is biomechanically similar to plate fixation in the management of partially stable pelvic ring injuries.

Delayed Diagnosis of Tuberculous Arthritis of the Knee in an Air Force Service Member: Case Report and Review of the Literature

Tuberculosis (TB) is a common disease worldwide affecting more than 2 billion people, including latent, pulmonary, and extrapulmonary TB. The presentation of disseminated TB is variable and dependent on the organs affected. Therefore, making the diagnosis and providing appropriate treatment can be delayed. We present a case of disseminated TB in a patient with Sjögren's syndrome on hydroxychloroquine monotherapy without traditional risk factors.

Review of 88 nail gun injuries to the extremities

BACKGROUND

Nail guns have been employed since 1959 to speed construction work, but with the increased productivity came an increasing number of injuries associated with the device. The majority of reported cases occur to the extremities.

METHODS

Our study retrospectively examines 88 cases of nail gun injuries to the extremities collected from a 4-year period. Radiographs and charts were used to collect data on anatomic site, type of treatment, type and duration of antibiotic treatment, and outcomes.

RESULTS

We found that infections associated with nail gun injuries were relatively rare (n=3) and in our study were limited to those patients who presented later than the day of injury. The majority of injuries were to the hand and knee (38.6% and 28.1%, respectively). No significant vascular or neurological injuries were encountered.

CONCLUSIONS

It appears that simple emergency room removal of the nail with local debridement and a short course of antibiotics is appropriate in most cases. The exception to this is where there is intra-articular or neurovascular involvement, then operative debridement is recommended.