Optimal Immobilization After Fixation of Bennett's Fracture: A Cadaveric Study.

OBJECTIVE: Treating high-level athletes involves a balance between early and safe return to play. Various types of protective immobilization have been recommended after operatively treated Bennett's fracture. The purpose of this study was to investigate if hand-based immobilization offers protection equivalent to forearm-based immobilization. MATERIALS AND METHODS: A cadaveric model of Bennett's fracture was created in 8 fresh-frozen, cadaveric forearms. Osteosynthesis was performed using a single headless compression screw. Three matched pairs were casted in either hand-based or forearm length, thumb spica casts, while 2 specimens remained un-casted as controls. Specimens were mounted on a custom testing apparatus. Weights were added in 6.8-kg increments until fixation failed and the fracture displaced. Fluoroscopy was performed after each trial. We used the Kruskal-Wallis non-parametric test to compare the groups. We considered P<.05 statistically significant. RESULTS: Failure of fixation occurred at 6.8 kg in the control specimens. Fixation failed in hand-based and forearm length casts at a mean of 18.1±5.1 kg. We did not find a statistically significant difference between median values of load at failure in kilograms across control specimens and 2 immobilization categories (P=.114). All specimens in the hand-based group sustained additional wrist injuries, while no additional injuries were noted in the forearm length group. CONCLUSION: Our study results showed that hand-based immobilization provides equivalent protection against fixation failure for operatively treated Bennett's fractures but may predispose athletes to increased risk of wrist injury compared with traditional, forearm-based casting. [Orthopedics. 2024;47(3):157-160.].

Hand and Upper Extremity Surgical Site Infection Rates Associated With Perioperative Corticosteroid Injection: A Review of the Literature.

BACKGROUND: Corticosteroid injection (CSI) has a relatively high benefit-to-risk ratio and is commonly administered to treat musculoskeletal conditions. However, perioperative CSI has been associated with an increased risk of postoperative infection. The literature suggests delaying surgery after CSI to minimize the risk of postoperative infection. We review the literature to summarize the most current knowledge on the association between perioperative CSI and infection rates for different hand and upper extremity procedures. METHODS: Two independent reviewers conducted a literature search using PubMed and Web of Science databases (through October 1, 2022). The database searches used were (((injection) AND (infection)) AND (risk)) AND ((hand) OR (wrist) OR (elbow) OR (shoulder)). English-language articles were screened for infection rates associated with CSI given temporally around upper extremity surgery, focusing between 6 months preoperatively and 1 month postoperatively. RESULTS: Nineteen articles including database queries and retrospective case-control or cohort studies were used after screening 465 articles. Most infection rates were increased in hand, wrist, elbow, and shoulder surgery between 3 months preoperatively and 1 month postoperatively. Intraoperative injection during elbow arthroscopy demonstrated increased infection rate relative to other upper extremity surgeries. CONCLUSIONS: Corticosteroid injection increased the risk of infection temporally around upper extremity surgeries; however, CSI provides benefits. The consensus regarding CSI timeline perioperatively has yet to be determined. The evidence supports an increased benefit-to-risk ratio when giving corticosteroids greater than 3 months preoperatively and greater than 1 month postoperatively for most upper extremity procedures, with relative contraindications within 1 month of upper extremity surgery.

Glenohumeral Cartilage Thickness: Implications in Prosthetic Design and Osteochondral Allograft Transplantation.

OBJECTIVE: A complete understanding of the glenohumeral joint anatomy is crucial for osteochondral allograft (OCA) transplantation and prosthetic design. However, existing data on the cartilage thickness distribution are not consistent. This study aims to describe the cartilage thickness distribution at both the glenoid cavity and humeral head in males and females. DESIGN: Sixteen fresh cadaveric shoulder specimens were dissected and separated to expose the glenoid and humeral head articular surfaces. The glenoid and humeral head were cut into 5-mm coronal sections. Sections were imaged and cartilage thickness was measured at 5 standardized points on each section. Measurements were analyzed based on age, sex, and regional location. RESULTS: For the humeral head, cartilage was thickest centrally (M = 1.77 ± 0.35 mm) and thinnest superiorly and inferiorly (M = 1.42 ± 0.37 mm, 1.42 ± 0.29 mm). At the glenoid cavity, cartilage was thickest in the superior and inferior areas (M = 2.61 ± 0.47 mm, 2.53 ± 0.58 mm) and thinnest centrally (M = 1.69 ± 0.22 mm). Males were found to have thicker cartilage at both the humeral head and glenoid (P = 0.0014, P = 0.0133). CONCLUSIONS: Articular cartilage thickness distribution of the glenoid and humeral head is nonuniform and reciprocal in nature. These results can be used to further inform prosthetic design and OCA transplantation. We noted a significant difference in cartilage thickness between males and females. This suggests that the sex of the patient should be taken into consideration when matching donors for OCA transplantation.

Clean Shot: Bacterial Contamination After Positive Pressure Irrigation of Low-Velocity Gunshot Wounds.

OBJECTIVE: Low-velocity gunshot wounds (LV-GSWs) are a common reason for emergency department visits. Optimal nonsurgical treatment has not been thoroughly studied and is not standardized. The goal of this study was to determine whether positive pressure irrigation reduces the bacterial contamination after a simulated GSW to soft tissue. METHODS: Nineteen lamb shank specimens were prepared with denim inoculated with Serratia marcescens cultures. A 9-mm pistol round was fired from a distance of 3 m through the contaminated denim into the lamb shank. A culture swab was placed in the wound directly after firing, after 250 cubic-centimeters (cc) irrigation with normal saline, and after an additional 250 cc irrigation (for a total of 500 cc). Swabs were then cultured to determine the amount of bacterial growth. RESULTS: Before irrigation, 0 (0%) plates showed no growth, 2 (10.5%) showed rare growth, 8 (42.1%) showed few growth, 6 (31.6%) showed moderate growth, and 3 (15.8%) showed many growth. After 500 cc irrigation, 2 (10.5%) showed no growth, 1 (5.3%) showed rare growth, 11 (57.9%) showed few growth, 2 (10.5%) showed moderate growth, and 3 (15.8%) showed many growth. Fisher exact test confirmed no significant change in bacterial concentration after irrigation ( P = 0.59). A Pearson test found no correlation between irrigation and bacterial growth (r = -0.15, P = -0.25). CONCLUSIONS: Positive pressure irrigation with up to 500 cc normal saline did not significantly alter the quantity of bacterial growth within a simulated GSW cavity. The data suggest that bedside positive pressure irrigation may not be beneficial in the initial emergency department treatment of LV-GSWs.

Factors affecting internal rotation following total shoulder arthroplasty.

Background: Reverse shoulder arthroplasty (RSA) was developed in the late twentieth century to provide a stable arthroplasty option for patients with rotator cuff deficiency arthropathy. Since its inception, there have been changes in materials, design, and positioning. One of the persistent clinical issues has been difficulty with internal rotation (IR) and the associated difficulty with behind the back activities. Implant design, positioning, and the available soft tissues may influence IR after RSA. The purpose of this systematic review is to assess factors that impact IR following RSA. Methods: The literature search, based on PRISMA guidelines, used 4 databases: Pubmed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials. We included clinical trials that compared different implantation and design modifications and assessed IR. Results: Of the 617 articles identified in the initial search, 46 satisfied the inclusion criteria. The articles explored multiple factors of RSA and their effects on IR, including humeral and glenoid components and muscle function and integrity. Among humeral factors affecting rotation, there was a broad consensus that: IR decreases as retroversion increases, humeral neck-shaft angle less than 155° improves IR, lateralized humeral offset does not improve IR, and shallow cups improve IR. Insert thickness was not associated with a reproducible effect. Of the studies evaluating the effect of glenoid components, there was majority agreement that glenosphere lateralization improved IR, and there were mixed results regarding the effects of glenosphere size and tilt. Others included one study in each: glenoid overhang, retroversion, and baseplate. One study found an association between teres minor insufficiency and improved IR, with mixed results in the presence of fatty infiltration in both teres minor and subscapularis. Most studies noted subscapularis repair had no effect on IR. Conclusion: Prosthetic variables affecting IR are not widely studied. Based on the existing literature, evidence is conflicting. More research needs to be undertaken to gain a greater understanding regarding which factors can be modified to improve IR in RSA patients.

Histologic Evaluation of the Triceps Brachii Tendon Insertion: Implications for Triceps-Sparing Surgery.

PURPOSE: Triceps detachment and olecranon osteotomy are 2 techniques used to enhance exposure in elbow surgery. Both the techniques can potentially add considerable morbidity and lengthen the recovery after surgery. Triceps-sparing surgery can potentially mitigate those issues. The purpose of this study was to evaluate the triceps tendon insertion at a histologic level to help improve triceps-sparing surgical techniques used in elbow trauma and arthroplasty. METHODS: Seventeen fresh-frozen cadaveric elbow specimens were collected. The olecranon and its soft tissue attachments were isolated. We performed gross measurements and sectioned the specimens for histologic evaluation in the saggital or coronal planes. The proximal-to-distal and medial-to-lateral dimensions of the tendon and the distance from the proximal tip of the olecranon to the proximal tendon insertion were measured microscopically on stained embedded sections. RESULTS: The proximal-to-distal dimension of the triceps tendon insertion was less than previously reported, whereas the medial-to-lateral dimension was similar. The true distance from the tip of the olecranon to the proximal tendon insertion was greater than the previously reported distance obtained via gross measurement. CONCLUSIONS: Gross measurement of the triceps tendon insertion overestimates and inaccurately represents the true insertional footprint. Gross measurement has been shown to demonstrate consistent disparity compared with histologic measurement. Histologic investigation provides a more accurate description. CLINICAL RELEVANCE: The finding that the distance from the articular tip of the olecranon to the proximal tendon insertion is greater than previously reported may have clinical implications. A triceps split approach may allow more visualization and exposure of the posterior joint and, therefore, lessen the need for triceps detachment or olecranon osteotomy.

Electrophysiological Findings in Common Median-Ulnar Nerve Interconnections and Their Clinical Implications.

Median and ulnar nerve interconnections commonly occur in the brachial plexus, forearm, and hand. Each is classified based on location, fiber type (sensory fibers, motor fibers, or both), and directionality (ie, carrying fibers from median to ulnar or vice versa). There are 4 main interconnections found in the forearm and hand: Martin-Gruber and Marinacci anastomoses in the forearm and Riche-Cannieu and Berrettini anastomoses in the hand. The presence of an interconnection may skew electrodiagnostic findings, possibly resulting in misdiagnosis and iatrogenic injury. Clinicians should perform nerve studies of both nerves at proximal and distal stimulation sites to rule out interconnections and guide treatment. This review details anatomy, electrodiagnostic findings, and clinical approach.

Distal Biceps Tendon Ruptures: An Epidemiological Analysis Using a Large Population Database.

BACKGROUND: The incidence of distal biceps tendon ruptures was studied more than 10 years ago in a small patient cohort. Recent diagnostic advancements have improved the ability to detect this rare injury. HYPOTHESIS: The incidence of distal biceps tendon ruptures will be significantly greater than previously reported. STUDY DESIGN: Descriptive epidemiologic study. METHODS: A query of the PearlDiver Technologies national database containing public and private insurance patients was used to estimate the national incidence of distal biceps tendon ruptures in the United States. A retrospective chart review of our local population identified demographic groups and risk factors that increased likelihood of injury. RESULTS: The estimated national incidence of distal biceps tendon rupture was 2.55 per 100,000 patient-years. The local incidence was 5.35 per 100,000 patient-years. The mean and median ages of patients in our regional cohort were 46.3 and 46 years, respectively. Males composed the majority of the injured population (national 95%, regional 96%). Smoking and elevated body mass index were found to be associated with increased likelihood of injury, while diabetes mellitus showed no association. CONCLUSION: The incidence of distal biceps tendon ruptures in this study was higher than previously reported.

The use of BMP-2 and screw exchange in the treatment of scaphoid fracture non-union.

Scaphoid non-union, particularly following internal fixation, is a vexing problem. A retrospective review was conducted analysing the outcome of 4 patients who failed initial open reduction and internal fixation of scaphoid fractures. Three fractures were located in the waist and the fourth in the proximal pole. All patients underwent screw exchange and Bone Morphogenic Protein (BMP)-2 sponge placement with no additional bone grafting. Patients were immobilised for 4 weeks and followed with serial radiographs in all cases and CT scans in 3 cases. All patients demonstrated evidence of bony union at an average of 53 days from surgery and ultimately returned to pain-free full activity. There were no complications. BMP-2 and screw exchange yielded a 100% union rate in patients with established scaphoid non-union. While this retrospective study represents a small number of patients and clearly requires further investigation, it presents a promising technique for managing a difficult clinical problem.

The incidence and demographics of shoulder repair in Wisconsin, 2002-2010.

IMPORTANCE: Recent evidence has demonstrated a profound increase in the incidence of shoulder surgery. Superior labral anterior and posterior (SLAP) repair is a common procedure that has been noted in other studies to be increasing. OBJECTIVE: The purpose of this study is to report the incidence and demographics of a single shoulder surgery code in the state of Wisconsin in order to evaluate whether it is being performed in increasing numbers relative to population. METHODS: In a retrospective review of the Wisconsin Hospital Association statewide database for the years 2002-2010, we queried one ICD-9 procedure code: 81.83, other repair of shoulder (not replacement or repair of recurrent dislocation). This code was selected because it would include SLAP repair and exclude most other common shoulder surgeries. The data retrieved includes ICD-9 diagnosis codes, county of surgery, patient age, and gender. RESULTS: The number of surgeries performed in Wisconsin over the course of the study increased by 91.4% between 2002 and 2010, starting at 5649 in 2002 and rising to 10,812 by 2010. The incidence of surgeries increased 83.1% over this time period: from 103.8 per 100,000 in 2002 to 190.1 per 100,000 in 2010. The ratio of male to female surgeries remained nearly constant at 3:2 throughout the length of the study. The mean patient age at time of surgery increased 2.6 years, from 48.3 in 2002 to 50.9 in 2010. CONCLUSIONS: The increase in number of shoulder surgeries is well beyond expectations based on population growth. The relatively high percentage of females does not correspond with reported gender ratios in other studies of similar shoulder procedures. The high mean age of patients and the large number of surgeries in older patients also is concerning. More educational effort needs to be given regarding the diagnosis and treatment of common shoulder conditions.

Magnetic resonance imaging study of glenohumeral relationships between genders.

BACKGROUND: During glenohumeral arthroplasty, not only should the dimensions of the prosthesis match the normal anatomy but also the relationship of the humeral head-greater tuberosity and humeral head inclination should be replicated to avoid muscular dysfunction. To date there is no evidence whether fit could be optimized with gender-specific prostheses. MATERIALS AND METHODS: Magnetic resonance (MR) arthrography imaging was used to evaluate 81 proximal humeral scans for 5 different anatomic parameters. The study group included 41 men and 40 women, aged 20 to 62 years. Anatomic parameters, including the humeral head height, humeral head width, humeral head-greater tuberosity distance, humeral head inclination, and glenoid version were measured using Horizon Rad Station 11.0 to evaluate the MR imaging. RESULTS: The humeral head height, width, and distance to the greater tuberosity were significantly different in size between genders. However, none of the anatomic relationships were different. The humeral head-greater tuberosity distance significantly correlated with the humeral head inclination in both men (r = 0.338; P < .05) and women (r = 0.448; P < .005). CONCLUSION: We conclude that there are no significant differences in glenohumeral relationships between genders.

Prevalence of carpal tunnel syndrome in pregnant women.

Carpal tunnel syndrome (CTS) is a frequent complication of pregnancy, with a prevalence reported as high as 62%. The most typical symptoms are numbness and tingling in the thumb, index finger, middle finger, and radial half of the ring finger. Other common manifestations include burning dysesthetic wrist pain, as well as the loss of grip strength and dexterity. Proximal radiation along the volar forearm, medial arm, and shoulder, while not as common, is not unusual. Symptoms are often worse at night and can be exacerbated by forceful activity and extreme wrist positions. It can be diagnosed to a high degree of specificity via history and physical examination. Median nerve function is impaired in virtually all pregnant women during the third trimester, even in the absence of symptoms. Treatment is symptomatic and usually consists of activity modification, splinting, edema control, and, if necessary, steroid injections. While most women experience symptomatic improvement following delivery, a significant percentage may still have some complaints up to at least 3 years post-partum and continue to wear splints. A high level of vigilance should be maintained in the management of these patients.

Ultrasound imaging of normal displacement of the extensor carpi ulnaris tendon within the ulnar groove in 12 forearm-wrist positions.

OBJECTIVE: Instability of the extensor carpi ulnaris (ECU) tendon can be a difficult clinical diagnosis because of normal changes in tendon position during wrist motion. Our goal was to determine the normal variation of ECU tendon displacement in 12 forearm-wrist positions. SUBJECTS AND METHODS: Ultrasound imaging of the ECU tendons of 40 symptom-free wrists of healthy volunteers (13 women, seven men; mean age, 22.3 years; range, 20-25 years) was performed. Each ECU tendon was examined in 12 positions: four wrist positions (ulnar deviation, radial deviation, flexion, and extension) in each of three forearm positions (pronation, supination, and neutral). RESULTS: ECU tendon displacement in the right hand was not significantly different from that in the left, and displacement in men did not differ significantly from that in women. There was a small but significant difference between displacement in the dominant and that in the nondominant hand (p < 0.02). Mean ECU tendon displacement was greatest in the supinated forearm position (p < 0.001) followed by the neutral position (p < 0.001) and was least in the pronated position (p < 0.001). Both ulnar deviation (p < 0.001) and flexion (p < 0.002) were associated with greater ECU tendon displacement than were radial deviation (p < 0.001) and extension (p < 0.002). Maximum percentage displacement volar to the ulnar border of the groove was 50% in flexed supination and ulnar deviation. The maximum displaced distance volar to the ulnar border of the groove was 5 mm. CONCLUSION: Sonographic evaluation of the ECU tendon is simple and practical. Knowledge of normal ECU displacement relative to the ulnar groove may help in evaluation of ulnar-sided wrist pain.

Coronoid fractures of the elbow.

Coronoid fractures of the ulna are relatively uncommon, yet critical injuries to recognize. They often occur in association with elbow dislocations and play an important role in elbow instability. Historic recommendations are to fix all large coronoid fracture fragments, as well as small fracture fragments associated with instability. There is little data regarding management of small coronoid fracture fragments. The coronoid process acts as a bony buttress to prevent posterior dislocation and has three soft tissue insertions which lend stability as well: the anterior joint capsule of the elbow, the brachialis muscle and the medial ulnar collateral ligament. Injured patients often present with swelling, tenderness and limited range of motion. After obtaining a detailed history and performing a careful physical examination, plain radiographs should be obtained. If present, dislocations are reduced and post-reduction stability is assessed. If the elbow is unstable, management usually consists of a combination of bony and soft-tissue repairs often including coronoid process repair. Loss of motion is the most common complication of these injuries. The current recommendation is to repair virtually all coronoid fractures associated with instability.

Elevation in compartment pressure following hypovolemic shock and fluid resuscitation: a canine model.

We induced hemorrhagic shock in seven dogs and then resuscitated them with intravenous (IV) lactated ringers. We then monitored anterior leg compartment pressures via a slit catheter during both bleeding and reperfusion. These values were compared with controls that received IV fluids without being bled. Compartment pressures in resuscitated dogs rose well above control values. These values were statistically significant when compared to controls via the paired student t test (P < .01). This model demonstrates that sufficient swelling occurs to significantly elevate compartment pressures, even in the absence of local trauma. While this elevation may not be sufficient enough to cause a compartment syndrome, it reinforces the notion that extremities that have experienced ischemia and reperfusion are at an increased risk for developing compartment syndrome.

Ulnar coronoid process anatomy: possible implications for elbow instability.

Ulnar coronoid process fractures are relatively uncommon injuries usually occurring with elbow dislocations and contributing to elbow instability. Recent evidence suggests coronoid tip fractures have a role in the instability. We sought to quantify the capsular and brachialis attachments of the ulnar coronoid process to better understand why instability occurs. We prepared eight fresh-frozen cadaveric specimens to ascertain the specific attachment locations. After dissection, we isolated and resected the proximal ulna, including the coronoid process and its soft tissue attachments. We then embedded, sectioned, and stained the specimens. The average distance from the tip of the coronoid to the proximal capsule was 2.36 +/- 0.39 mm. The average distance from the tip of the coronoid to the proximal brachialis insertion was 10.13 +/- 1.6 mm. Most coronoid tip fractures included disruption of the anterior capsule, which potentially explains why instability can be associated with these fractures.