Faculty Bibliography

Metacarpophalangeal (MP) joint contractures are common after traumatic injury, and can be difficult to manage. After surgical capsulectomy, it remains challenging to maintain motion that was obtained at the time of surgery. Our group uses a novel, prefabricated digital external fixator to provide both distraction, and motion therapy across the MP joint after surgical treatment of MP contracture. The purpose of this technique is to demonstrate the effectiveness of an adjunctive dynamic distraction external fixator for the maintenance of joint motion after surgical treatment of MP contractures of the border digits.

OBJECTIVE: Identification of Gerdy's tubercle is the mainstay to any approach to the knee. Most surgical approaches to the proximal tibia and distal femur reference Gerdy's tubercle as a critical landmark. Its identification is therefore paramount. Unfortunately, the bony landmark can be skewed by soft tissue swelling, morbid obesity, or disruption from bony injury. The objective of this study was to determine a reliable way of identifying the normal anatomic location of Gerdy's tubercle using surrounding structures during any surgical approach to the knee. DESIGN: Anatomic cadaver study. SETTING: Academic laboratory center. MATERIALS AND METHODS: Twenty-four adult human cadaver lower extremities as 12 matched pairs were used. Systematic identification and measurement from the point of intersection of a line drawn between 2 corners of a box created using the tibial tubercle, inferior pole of the patella, and the fibula head were performed and recorded. MAIN OUTCOME MEASUREMENT: Mean distance from cutaneous point of intersection to Gerdy's tubercle upon dissection. RESULTS: The mean distance from the point of intersection to Gerdy's tubercle was 2.58 +/- 2.01 mm with a range from 0 to 8. The mean distances for the right and left lower extremities were 2.67 +/- 2.02 and 2.5 +/- 2.11 mm, respectively. Statistical analysis using 2-tailed independent t test with a significance set at P <0.05 revealed no significant differences with P = 0.84. CONCLUSIONS: Our group has identified the point of intersection among 3 landmarks forming a point of intersection. This point is the intersection of a line drawn between 2 corners of a box created using the tibial tubercle, inferior pole of the patella, and the fibula head. This serves as a reliable and reproducible method to identify Gerdy's tubercle.

BACKGROUND: Compartment syndrome of any extremity is a limb-threatening emergency requiring an emergent surgical management. Thus, ruling out compartment syndrome is often high on the list of priorities when treating high-energy injuries and fractures. However, even in the most seemingly benign injuries, this dangerous diagnosis must always remain on the differential and suspicion must remain high. CASE PRESENTATION: 23-year-old factory worker presents after a low energy entrapment injury to his left forearm. Initial work-up and evaluation noted an isolated radial head dislocation with a normal physical motor and sensory exam. However, maintaining high suspicion for compartment syndrome despite serial normal physical exams, led objective compartment pressure measurement leading to definitive diagnosis. Emergent surgical intervention via compartment fasciotomies was performed, along with closed reduction and ligament repair. At 1 year follow-up, the patient was well-healed, back to work with full range of motion and not activity limitations. CONCLUSION: Despite a seemingly benign injury pattern, and a relatively low energy mechanism, vigilant concern for compartment syndrome following any kind of entrapment injury should initiate serial examinations and compartment pressure measurements especially in circumstances with continued swelling and inability to perform an accurate clinical assessment due to an obtunded or medicated patient.

OBJECTIVE: Identification of the radial nerve is necessary during the posterior approach to the humerus in an effort to maintain its integrity. Other than anatomic descriptions of the radial nerve with respect to osseous structures, there are few superficial intraoperative landmarks along the course of the traditional triceps-splitting approach to provide facile nerve identification. The objective of this study was to determine the reliability of using the anatomic intersection of the long and lateral heads of the triceps and the triceps aponeurosis as a superficial reference point for radial nerve identification during the posterior approach to the humerus. METHODS: Thirty adult human cadaver upper extremities as 15 matched pairs were used. Systematic identification and measurement from the point of intersection between the long and lateral heads of the triceps and the triceps aponeurosis to the distal most aspect of the radial nerve as it coursed the posterior humerus at its midaxial point was performed and recorded. RESULTS: Mean distance was found to measure 39.0 +/- 2.1 mm (range, 36-44 mm), approximating a fixed distance, two finger breadths proximal to our identified point of intersection. Statistical analysis between the two matched pair groups yielded no significant difference in measured distances (P = 0.88). CONCLUSIONS: Our group has identified the point of intersection among three landmarks forming a point of intersection. This point is the confluence of the long and lateral heads of the triceps and the triceps aponeurosis. This serves as a visualized anatomic reference point during the posterior surgical exposure to the humerus and can be used to identify the radial nerve as it courses the posterior humerus.

Over the years a variety of cartilage restorative procedures have been developed for athletes to address focal, full-thickness cartilaginous defects in the knee joint, including microfracture, osteochondral autografts, osteochondral allografts, autologous chondrocyte implantation (ACI), and most recently, next-generation ACI involving scaffolds or cell-seeded scaffolds. Since its introduction, ACI has yielded some very promising results in athletes and nonathletes alike. Rehabilitation following ACI requires an in-depth understanding of joint mechanics, and knowledge of the biologic and biomechanical properties of healing articular cartilage. A patient-, lesion-, and sports-specific approach is required on the part of the trainer or physical therapist to gradually restore knee joint function and strength so that the athlete may be able to return to competitive play. This article reviews the rehabilitation protocols for injured athletes following an ACI procedure.

Since 1996, Vibrio parahaemolyticus serotype O3:K6 and closely related strains have been associated with an increased incidence of V. parahaemolyticus gastroenteritis worldwide, suggesting the emergence of strains with enhanced abilities to cause disease. One hypothesis for the recent emergence of V. parahaemolyticus O3:K6 and related strains is an enhanced capacity for environmental survival relative to other strains, which might result in increased human exposure to these organisms. Therefore, the objective of this study was to test the hypothesis that survival or growth characteristics of clinical V. parahaemolyticus isolates differ from those of nonclinical isolates under different environmental conditions. Twenty-six V. parahaemolyticus isolates selected to represent either clinical or food sources were monitored for either survival following exposure to high magnesium (300 mM) or growth under iron-limited conditions. Isolates in each category (clinical or food) differed widely in survival capabilities following 24 h of exposure to 300 mM Mg2+. Although 4 of 15 clinical isolates grew better at approximately 0.96 microM Fe2+ (iron-limited conditions) than at 50 microM Fe2+ (iron-rich conditions), as an entire group clinical isolates in this study were not more effective at growing under iron-limited conditions than were strains not associated with disease. Within the diverse collection of strains examined in these experiments, neither growth characteristics in low-iron environments nor survival capabilities following exposure to high magnesium concentrations were uniformly different between clinical and nonclinical V. parahaemolyticus isolates. Therefore, neither phenotypic characteristic can be used to reliably differentiate potentially pathogenic V. parahaemolyticus strains.

The emergence of new bone grafting options and alternatives has led to significant uncertainty when determining the most appropriate product for surgical procedures requiring bone graft in orthopedics. Allografts, demineralized bone matrices, synthetic bone graft substitutes, and osteoinductive growth factors are all viable options, yet there is a lack of data reporting clinical usage of these products. This correspondence reports on the use of bone grafting products at the Hospital for Special Surgery for a 27-month period and makes recommendations based on surgical usage, safety, and cost. Approximately half (48.6%) of all bone graft substitutes were implanted during spinal surgery. Arthroplasty, trauma, and foot/hand cases all used considerable amounts of bone grafting products as well (20.1%, 19.0%, 12.1%, respectively). Considerable differences were noticed in usage of bone grafting products among each orthopedic discipline. Of all bone graft substitutes used in arthroplasty, 14.4% were demineralized bone matrices, whereas 56.8% were allografts. Demineralized bone matrix grafts were used in 82% of trauma surgery and 89% of foot/hand cases. An increase in synthetic bone graft alternatives was noticed near the end of our investigation period.