Faculty Bibliography

Background The use of tourniquets and their role in extremity-based microsurgery has not been thoroughly investigated. The purpose of this study was to investigate tourniquet use and its associated outcomes and complications. Methods Approval from the Institutional Review Boards was granted at each site. A retrospective chart review was completed for patients who had undergone extremity-based microsurgery with the use of a tourniquet between 01/01/2018 and 02/01/2021 at two large academic institutions. Demographic characteristics, initial reasons for surgery, complications, and outcomes were recorded. Patients were separated into groups based on tourniquet-use during three operative segments: (1) flap elevation, (2) vessel harvest and (3) microvascular anastomosis. An internal comparison of complication rate was performed between cases for which a tourniquet was used for one operative segment to all cases in which it was not used for the same operative segment. Univariate and multivariate statistical analyses were performed to identify statistically significant results. Results A total of 99 patients (106 surgeries) were included in this study across sites. The mean age was 41.2 years and 67.7% of the patients were male. The most common reason for microsurgical reconstruction was a traumatic event (50.5%). The need for an additional unplanned surgery was the most common surgical complication (16%). 70% of procedures used a tourniquet for flap elevation. When these cases were compared to those that did not use a tourniquet for flap elevation, there was no difference in complication rates. 61% of procedures used a tourniquet for vessel harvest and 32% for anastomosis. Similarly, additional analyses identified no difference in complication rates when compared to procedures for which a tourniquet was not used for the intervention. Conclusions Based on these results, the authors encourage the use of tourniquets for extremity-based microsurgery to enable bloodless dissection without the concern of increased complication rates.

INTRODUCTION/BACKGROUND:The purpose of this study was to evaluate the role of body mass index (BMI) in predicting postoperative complications following myocutaneous free flap transfer. In addition, we sought to identify certain body composition variables that may be used to stratify patients into low- versus high-risk for gracilis myocutaneous free flap with skin paddle failure. METHODS:Using the National Surgical Quality Improvement Program database, we collected data for all patients who underwent myocutaneous free flap transfer from 2015 to 2021. Demographic data, medical history, surgical characteristics, and postoperative outcomes, including complications, reoperations, and readmissions, were collected. Body mass index was correlated with outcome measures to determine its role in predicting myocutaneous free flap reliability. Subsequently, we retrospectively obtained measurements of perigracilis anatomy in patients who underwent computed tomography angiography bilateral lower extremity scans with intravenous contrast at our institution. We compared body composition data with mathematical equations calculating the potential area along the skin of the thigh within which the gracilis perforator may be found. RESULTS:Across the United States, 1549 patients underwent myocutaneous free flap transfer over the 7-year study period. Being in obesity class III (BMI ≥40 kg/m2) was associated with a 4-times greater risk of flap complications necessitating a return to the operating room compared with being within the normal BMI range. In our computed tomography angiography analysis, average perigracilis adipose thickness was 18.3 ± 8.0 mm. Adipose thickness had a strong, positive exponential relationship with the area of skin within which the perforator may be found. CONCLUSIONS:In our study, higher BMI was associated with decreased myocutaneous free flap reliability. Specifically, inner thigh adipose thickness can be used to estimate the area along the skin within which the gracilis perforator may be found. This variable, along with BMI, can be used to identify patients who are considered high-risk for flap failure and who may benefit from additional postoperative monitoring, such as the use of a color flow Doppler probe and more frequent and prolonged skin paddle monitoring.

BACKGROUND/UNASSIGNED:The purpose of this study was to evaluate the association between timing of nerve repair and the ability to perform a primary nerve repair versus a bridge repair requiring the use of allograft, autograft, or a conduit in lacerated upper extremity peripheral nerve injuries. METHODS/UNASSIGNED:This is a retrospective case-control study of patients who underwent upper extremity nerve repair for lacerated peripheral nerves identified by Current Procedural Terminology codes. Timing of injury and surgery, as well as other information such as demographic information, mechanism of injury, site of injury, and type of nerve repair, was recorded. The odds of a patient requiring bridge repair based on the duration of time between injury and surgery was evaluated using logistic regression. RESULTS/UNASSIGNED:A total of 403 nerves in 335 patients (mean age 35.87 ± 15.33 years) were included. In all, 241 nerves were primarily repaired and 162 required bridge repair. Patients requiring bridge repair had a greater duration between injury and surgery compared with patients who underwent primary repair. Furthermore, the nerves requiring bridge repair were associated with a greater gap compared with the nerves repaired primarily. Based on logistic regression, each 1-day increase in duration between injury and surgery was associated with a 3% increase in the odds of requiring bridge repair. CONCLUSIONS/UNASSIGNED:There is no defined critical window to achieve a primary nerve repair following injury. This study demonstrated that nerve injuries requiring bridge repair were associated with a significantly greater delay to surgery.

The goal of this study was to define safe zones to prevent radial nerve injury in an extended deltopectoral approach. Relative distances of the upper margin (UMRN) and lower margin (LMRN) of the radial nerve to the proximal and distal borders of the pectoralis major and deltoid insertions were measured in 20 cadaveric arms. Four proximal humeral zones were identified (zone I, proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon; zone II, proximal border of the deltoid tendon to the distal border of the pectoralis major tendon; zone III, distal border of the pectoralis major tendon to the distal border of the deltoid tendon; and zone IV, distal to the distal border of the deltoid tendon). On fluoroscopic measurement, mean distances between the UMRN and the proximal border of the pectoralis major tendon and the proximal border of the deltoid tendon were 71.6±2.1 mm and 26.2±2.5 mm, respectively. The incidence of the radial nerve in the spiral groove within each defined zone was as follows: zone I, 0%; zone II, 50%; zones III and IV, 100%. There was a significant association between anatomic zone and radial nerve entry into the spiral groove, χ²(3, N=88)=64.53, P<.001. The proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon (zone I) is a safe location to avoid injury to the radial nerve. We recommend placing cerclage wires proximal to zone I from lateral to medial to avoid entrapment of the radial nerve. [Orthopedics. 2023;46(1):e31-e37.].

PURPOSE/OBJECTIVE:The extensor retinaculum of the wrist, a thickening of the deep forearm fascia, is often used as do- nor graft material for annular pulley reconstructions and bone-retinaculum-bone grafts for ligament reconstructions. The purpose of our study was to identify the relationships between the radial and ulnar styloids, readily recogniz- able topographic landmarks of the wrist, and the anatomic boundaries of the retinaculum. METHODS:The extensor retinacula of 12 preserved, right cadaver wrists (3 male and 9 female) were studied by gross dissection using 3.5-power loupe magnification. The proxi- mal and distal extents of the retinaculum were identified and marked with needles, and their distances from the radial and ulnar styloids measured to determine the lengths of the retinaculum on both sides. RESULTS:The extensor retinaculum on the radial side extended 23.9 ± 2.9 mm proximal to the radial styloid and 5.8 ± 2.6 mm distal to the styloid for a total length of 29.7 ± 3.8 mm. On the ulnar side, the retinaculum extended 2.4 ± 1.4 mm proximal to the ulnar styloid and 17.9 ± 2.6 mm distal to the styloid for a total length of 20.3 ± 2.9 mm. CONCLUSIONS:The extensor retinaculum has a consis- tent relationship with the readily recognized topographic landmarks of the radial and ulnar styloids. The use of the extensor retinaculum as donor material for pulley and liga- ment reconstruction make these findings useful for surgical planning.

The objective of this study was to determine the role of ad- junctive surgical procedures on the median nerve for carpal tunnel syndrome as measured by somatosensory evoked potentials (SEPs) on the nerve. Fifty-five median nerves in 47 patients were studied. In each patient, a base-line SEP was recorded in the operating room prior to incision and then intraoperatively following each of three sequential pro- cedures: division of the transverse carpal ligament, an epi- neurolysis of the nerve, and finally, either an epineurotomy or epineurectomy that we refer to as a "limited internal neu- rolysis" since it did not involve any intraneural dissection of fascicles. Comparison of the baseline mean SEP latency for the median nerve, referred to as N19 (negative polarity = 19 msec), showed a statistically significant improvement following each of the three procedures. The average reduc- tion of latency after ligament release alone was 1.52 msec, and the total improvement in latency from baseline through limited internal neurolysis was 4.72 msec. Our study showed that epineurolysis followed by a limited internal neurolysis using either an epineurotomy or epineurectomy produced a significant electrophysiologic improvement in the median nerve. There was no significant difference when comparing epineurotomy and epineurectomy.

BACKGROUND/UNASSIGNED:Much has been written about the diagnosis and treatment of soft tissue mallet injuries. However, there has been little regarding the characteristics of this injury affecting patients' prognosis. The purpose of this prospective study was to identify factors influencing the outcome of treatment of soft tissue mallet injuries. METHODS/UNASSIGNED:12 months. RESULTS/UNASSIGNED:15°. Those failing splint treatment were older compared with those successfully treated. Patient compliance was significantly associated with a successful outcome. Factors that did not significantly affect success included time to treatment, initial injury severity, splinting duration, sex, and ligamentous laxity. Disabilities of Arm, Shoulder, and Hand scores >0 were not associated with treatment failure. Radiographic and clinical extension lag were statistically comparable. CONCLUSIONS/UNASSIGNED:This study shows strong association between the success of splint treatment, younger patient age, and compliance with the treatment protocol. Despite this finding, most patients did not report any functional limitations, irrespective of the treatment success. In contrast to prior results, time to treatment and initial extensor lag did not significantly affect treatment success.

Neuropathic symptoms involving the wrist are a common clinical presentation that can be due to a variety of causes. Imaging plays a key role in differentiating distal nerve lesions in the wrist from more proximal nerve abnormalities such as a cervical radiculopathy or brachial plexopathy. Imaging complements electrodiagnostic testing by helping define the specific lesion site and by providing anatomical information to guide surgical planning. This article reviews nerve anatomy, normal and abnormal findings on ultrasonography and magnetic resonance imaging, and common and uncommon causes of neuropathy.