Domenica A. Delgado

Plantar Plating for the Treatment of Proximal Fifth Metatarsal Fractures in Elite Athletes

Proximal fifth metatarsal fractures, zones II and III, are commonly treated surgically, especially in elite athletes. Intramedullary screw fixation remains the most used construct despite nonunion and refracture. High tensile forces on the plantar-lateral aspect of the fifth metatarsal are difficult to control, and intramedullary screw fixation depends on ideal screw position, length, and width. The authors present a plantar plating technique with cancellous bone autograft for zones II and III proximal fifth metatarsal fractures. Rotational instability and plantar-lateral gapping are resisted by applying a compression plate to the tension side of the fracture, eliminating causes for failure. [Orthopedics. 2017; 40(3):e563-e566.].

A Biomechanical Comparison of Fifth Metatarsal Jones Fracture Fixation Methods

Background: Fifth metatarsal base fractures of the metaphyseal-diaphyseal watershed junction (Jones fracture) are commonly treated with surgical fixation in athletes. Intramedullary screw fixation remains the most utilized construct, although plantar-lateral plating is an alternative. Purpose/Hypothesis: The purpose was to compare the mechanical strength of fracture fixation between an intramedullary screw and plantar-lateral plating. The hypothesis was that plantar-lateral plate fixation would allow for more cycles and higher peak loads before failure, as well as less fracture gapping, than would an intramedullary screw in cadaveric foot specimens with simulated Jones fractures exposed to cantilever bending. Study Design: Controlled laboratory study. Methods: Twelve pairs of male cadaver feet were separated into 2 groups (plate or screw) to conduct contralateral comparative testing of 2 devices with equally numbered right and left feet. For each fifth metatarsal, an osteotomy with a microsagittal saw was created to simulate a Jones fracture. The plate group underwent fixation with a 3.0-mm 4-hole low-profile titanium plate placed plantar-laterally with 3 locking screws and 1 nonlocking screw. The screw group underwent fixation with a 40- or 45-mm × 5.5-mm partially threaded solid titanium intramedullary screw. After fixation, the metatarsals were excised for biomechanical testing. Cyclic cantilever failure testing was conducted with a gradient-cycle method. Sinusoidal loading forces were applied, increasing by 5.0-pound-force increments per 10 cycles, until each specimen experienced mechanical failure of implant or bone. Failure mode, number of cycles to failure, peak failure load, gap width at the last mutual prefailure loading, and video data were recorded. Paired 2-tailed t test (α = 0.05) was used to compare groups (P < .05 set for significance). Results: Failure mode in both groups occurred predominantly at the bone-implant interface. Plate fixation resulted in significantly higher mean ± SD values for cycles to failure (63.9 ± 27.0 vs 37.3 ± 36.9, P = .01) and peak failure load (159.2 ± 60.5 N vs 96.5 ± 45.8 N, P = .01), with a significantly lower mean gap width (0.0 ± 0.0 mm vs 3.2 ± 2.4 mm, P < .01). Conclusion: As compared with intramedullary screw fixation, plantar-lateral plating allowed for greater cycles to failure and peak load before failure, as well as less gap width, when applied to cadaver foot specimens with simulated Jones fractures exposed to cantilever bending in a load frame. Clinical Relevance: Early return to play among athletes before Jones fracture union is associated with increased risk of failure. This study introduces a plantar-lateral plating construct that performed more favorably than intramedullary screw fixation when applied to simulated Jones fractures in cadaveric foot specimens. Further clinical comparative studies are needed to assess the clinical use of this construct.

The Risk of Impingement With Sexual Activity in Femoroacetabular Impingement Syndrome Due to Cam Morphology: Shape Matters

Background: Sexual difficulties and dysfunction are common in patients with femoroacetabular impingement syndrome (FAIS) secondary to hip pain and stiffness. Purpose: To determine the risk of impingement in patients with FAIS during common sexual positions using 3-dimensional computer-simulated collision detection before and after cam correction. Study Design: Descriptive laboratory study. Methods: Ten computed tomography scans of the pelvis and femur from patients with FAIS due to isolated cam morphology were retrospectively reviewed. Three-dimensional osseous models were developed using Mimics software. The cam deformity was then completely corrected. Simulations of hip range of motion for the most common sexual positions for men (n = 15) and women (n = 14) were conducted before and after cam resection. Impingement was determined for each sexual position. Position safety was defined as ≤20% of models demonstrating impingement in a position. Descriptive and simple comparative statistics were calculated. Results: There was no sexual position that was impingement free in all models before cam correction. After cam correction, 11 (37.9%) of 29 total positions were impingement free. There was a significant decrease in impingement from before to after cam correction (40.7% vs 11.4%, respectively, of all female positions [P < .0001]; 26.0% vs 6.7%, respectively, of all male positions [P < .0001]). There was a significant increase in the number of “safe” positions from before to after cam correction (4 vs 11, respectively, of all female positions [P = .008]; 7 vs 15, respectively, of all male positions [P = .001]). Conclusion: After cam correction, there was a significant reduction in the impingement rate and a significant increase in the number of “safe” sexual positions. Clinical Relevance: Impingement in patients with cam morphology is common during sexual activity. Surgical correction of cam morphology significantly reduces the rate of impingement. Although this laboratory imaging-only study did not account for patient symptoms, this likely translates to significant symptomatic improvement during sexual activity after surgical cam correction.

MRI prevalence and characteristics of supraacetabular fossae in patients with hip pain

Background: Supraacetabular fossae (SAF) are normal anatomic variants found at the 12 o’clock position of the acetabulum and can be mistaken for osteochondral defects. Purpose: Determine SAF prevalence on MRI of patients with hip pain. Characterise SAF by type, size, and location. Determine sensitivity of radiology reports and sensitivity of radiographs in SAF detection. Methods: MRIs performed over 1 year in patients with hip/groin pain were analysed for SAF. Measurements of SAF in the coronal and sagittal planes and location using clockface notation were recorded. Radiology reports were reviewed to determine if SAF were identified and radiographs were assessed for presence of SAF. Mean characteristics of type 1 and 2 SAF were compared using Student’s t-test. Results: 214 hips (mean age 35.9 ± 14.2 years; 66.8% female) were analysed. Twenty-seven hips (12.6%) had SAF. There were five type 1 SAF (mean age 16.8 ± 2.2 years) and 23 type 2 SAF (mean age 33.0 ± 16.3 years). Mean dimensions of type 1 and 2 SAF (coronal width × sagittal width × depth, in millimetres) were 7.1 × 6.5 × 3.4 and 6.1 × 5.9 × 2.8, respectively. Mean clockwise location in the coronal and sagittal planes (in minutes) was 1236 and 1212 for type 1 SAF and 1213 and 1207 for type 2 SAF. Radiology reports identified 7.1% of SAF identified on MRI. Plain radiographs demonstrated 67.9% of SAF identified on MRI. Conclusion: This study found a 12.6% prevalence of SAF in hips. Radiology reports had a 7.1% sensitivity in correctly identifying SAF on MRI. IRB: Pro00016584

A Biomechanical Comparison of Fifth Metatarsal Jones Fracture Fixation Methods - What is the Ideal Construct?

Fifth metatarsal base fractures of the metaphyseal-diaphyseal watershed junction (Jones fractures) are commonly treated with surgical fixation in athletes. Intramedullary screw fixation remains the most utilized construct despite reports of non-union and refractures. This paper compares the biomechanical strength of an intramedullary screw with a plantar-lateral plating construct applied to simulated Jones fractures in paired cadaver foot specimens.