Vascularized Fibular Epiphyseal Transfer for Pediatric Limb Salvage: Review of Applications and Outcomes.

Vascularized fibular epiphyseal transfer (VFET) offers a functional advantage in pediatric limb salvage due to the preservation of growth potential and an articular surface for remodeling. This review summarizes the available evidence on the clinical characteristics and outcomes of pediatric reconstruction applying VFET at different recipient sites and with varying techniques. VFET was used to reconstruct the proximal humerus, distal radius or ulna, proximal femur, distal fibula, calcaneus, and mandible. Although most often harvested on the anterior tibial artery, VFET has also been performed using the peroneal artery, the inferior lateral genicular artery, and a dual pedicle. Recipient site flap inset most often involved fixation with plates and/or screws as well as soft tissue reconstruction using a retained slip of biceps femoris tendon. Outcomes included limb growth, range of motion, and strength. The most common reported complications were bone flap fracture and peroneal nerve palsy. The anterior tibial artery was the most applied pedicle with reliable limb growth, but with the added risk of postoperative peroneal palsy. Bone flap fracture most often occurred at the proximal humerus and femur recipient sites. Plate fixation and the combined use of allograft had lower instances of bone flap fracture. This review highlights how the anticipated dynamic growth and remodeling this free flap offers in the long term must be weighed against its complexity and potential complications.

Retained Functional Antibiotic Hip Spacers Have High Rates of Stem Loosening, Subsidence, and Reoperation.

BACKGROUND: Functional antibiotic hip spacers for treatment of periprosthetic joint infection may be retained in patients deemed too sick for reimplantation, or who elect to forego additional surgery. Our aim was to characterize reoperations, modes of failure, and function outcomes in patients who have retained hip spacers. METHODS: We performed a retrospective review of 43 hips that underwent placement of an articulating hip spacer between January 1, 2014 and November 30, 2021. There were 28 hips that completed 2-stage exchange (TS group) and were reimplanted at mean 4 months (range, 2 to 10). The other 15 hips underwent planned spacer retention (RS group). Mean follow-up was 2.9 years (range, 1 to 6.1 years). The RS group was older (74 versus 66 years, P = .005) and had a higher age-adjusted Charlson Comorbidity Index (4.4 versus 3.3, P = .04) compared with the TS group. RESULTS: Overall survivorship free of reinfection was 91% at 1 year and 86% at 5 years. There were 6 RS hips that underwent reimplantation for spacer failure at a mean of 23 months (range, 6 to 71 months) and 8 had radiographic stem loosening/subsidence. Patients who had a retained spacer at final follow-up were more likely to require a walker (P = .005) or wheelchair (P = .049) compared with patients who underwent reimplantation. CONCLUSIONS: Retained hip spacers can decrease overall surgical burden, but are associated with high rates of stem loosening, subsidence, and unplanned reoperation. Planned spacer retention should be undertaken with caution in patients healthy enough to undergo reimplantation.

Conversion Total Hip Arthroplasty in the Era of Bundled Care Payments: Impacts on Costs of Care.

BACKGROUND: Conversion hip arthroplasty is defined as a patient who has had prior open or arthroscopic hip surgery with or without retained hardware that is removed and replaced with arthroplasty components. Currently, it is classified under the same diagnosis-related group as primary total hip arthroplasty (THA); however, it frequently requires a higher cost of care. METHODS: A retrospective study of 228 conversion THA procedures in an orthopaedic specialty hospital was performed. Propensity score matching was used to compare the study group to a cohort of 510 primary THA patients by age, body mass index, sex, and American Society of Anesthesiologists score. These matched groups were compared based on total costs, implants used, operative times, length of stay (LOS), readmissions, and complications. RESULTS: Conversion THA incurred 25% more mean total costs compared to primary THA (P < .05), longer lengths of surgery (154 versus 122 minutes), and hospital LOS (2.1 versus 1.56 days). A subgroup analysis showed a 57% increased cost for cephalomedullary nail conversion, 34% increased cost for sliding hip screw, 33% for acetabular open reduction and internal fixation conversion, and 10% increased costs in closed reduction and percutaneous pinning conversions (all P < .05). There were 5 intraoperative complications in the conversion group versus none in the primary THA group (P < .01), with no statistically significant difference in readmissions. CONCLUSION: Conversion THA is significantly more costly than primary THA and has longer surgical times and greater LOS. Specifically, conversion THA with retained implants had the greatest impact on cost.

Use of Tetrahydrocannabinol and Cannabidiol Products in the Perioperative Period Around Primary Unilateral Total Hip and Knee Arthroplasty.

BACKGROUND: Given the opioid crisis in America, patients are trying alternative medications including tetrahydrocannabinol (THC) and other cannabidiol (CBD) containing products in the perioperative period, especially in states where these products are legal. This study sought to analyze usage rates of CBD/THC products in the perioperative period for primary unilateral total hip and knee arthroplasty (THA/TKA) patients and identify a possible association with post-operative opioid use. METHODS: A prospective cohort of primary unilateral THA/TKA patients were enrolled at a single institution. Patients who completed detailed pain journals were retrospectively surveyed for CBD/THC product usage. Pain medications were converted to morphine milligram equivalents (MME). RESULTS: Data from 195 of the 210 patients (92.9% response rate) following primary arthroplasty were analyzed. Overall, 16.4% of arthroplasty-22.6% (n = 19) of TKA and 11.7% (n = 13) of THA-patients used CBD/THC products in the perioperative period. There was a wide variety of usage patterns among those using CBD/THC products. In comparing CBD/THC users and non-users, there was no significant difference in the length of narcotic use, total morphine milligram equivalents taken, narcotic pills taken, average post-op pain scores, the percentage of patients requiring a refill of narcotics, or length of stay. CONCLUSION: Understanding that CBD/THC usage was not consistent for patients who used these products, 22.6% of TKA and 11.7% of THA patients tried CBD/THC products in the perioperative period. In this small sample, CBD/THC use was not associated with a major effect on narcotic requirements. Further studies on the effects of CBD/THC are needed as these therapies become more widely available.

Opioid Use After Discharge Following Primary Unilateral Total Hip Arthroplasty: How Much Are We Overprescribing?

BACKGROUND: The opioid crisis pressures orthopedic surgeons to reduce the amount of narcotics prescribed for postoperative pain management. This study sought to quantify postoperative opioid use after hospital discharge for primary unilateral total hip arthroplasty (THA) patients. METHODS: A prospective cohort of primary unilateral THA patients were enrolled at a single institution. Detailed pain journals tracked all prescription and over-the-counter pain medication, quantity, frequency, and visual analog scale pain scores. Pain medications were converted to morphine milligram equivalents (MME). RESULTS: Data from 121 subjects were analyzed; the average visual analog scale pain score was 3.44 while taking narcotics. The average number of days taking narcotics was 8.46 days. The distribution of days taking narcotics was right shifted with 50.5% of patients off narcotics after 1 week, and 82.6% off by 2 weeks postoperatively. The average number of narcotic pills prescribed was significantly greater than narcotic pills taken (72.5 vs 28.8, P < .0001). The average MME prescribed was significantly greater than MME taken (452.1 vs 133.8, P < .0001). The average excess narcotic pills prescribed per patient was 51.7 pills. And 71.9% took fewer than 30 narcotic pills; 90.9% patients took fewer than 50 narcotic pills. Also, 10.7% did not require any narcotics; 9.9% required a refill of narcotics; and 33.1% went home the day of surgery. CONCLUSION: Significantly more narcotics were prescribed than were taken in the postoperative period following THA with an average 51.7 excess narcotic pills per patient. Adjusting prescribing patterns to match patient narcotic usage could reduce the excess narcotic pills following THA.

Opioid Use After Discharge Following Primary Unilateral Total Knee Arthroplasty: How Much Are We Over-Prescribing?

BACKGROUND: The opioid crisis pressures orthopedic surgeons to reduce the amount of narcotics prescribed for post-operative pain management. This study sought to quantify post-operative opioid use after hospital discharge for primary unilateral total knee arthroplasty (TKA) patients. METHODS: A prospective cohort of primary unilateral TKA patients performed by one of 5 senior fellowship-trained arthroplasty surgeons were enrolled at a single institution. Detailed pain journals tracked all prescriptions and over-the-counter pain medications, quantities, frequencies, and visual analog scale pain scores. Narcotic and narcotic-like pain medications were converted to morphine milligram equivalents (MME). Statistical analysis was performed using Student's t-test with α < 0.05. RESULTS: Data from 89 subjects were analyzed; the average visual analog scale pain score was 6.92 while taking narcotics. The average number of days taking narcotics was 16.8 days. The distribution of days taking narcotics was right shifted with 52.8% of patients off narcotics after 2 week, and 74.2% off by 3 weeks post-op. The average MME prescribed was significantly greater than MME taken (866.6 vs 428.2, P < .0001). The average number of narcotic pills prescribed was significantly greater than narcotic pills taken (105.1 vs 52.0, P < .0001). The average excess narcotic pills prescribed per patient was 53.1 pills. About 48.3% took fewer than 40 narcotic pills; 75.3% took fewer than 75 narcotic pills. About 3.4% did not require any narcotics; 40.5% required a refill of narcotics. Also, 9.0% went home the day of surgery. CONCLUSION: Significantly more narcotics were prescribed than were taken in the post-operative period following TKA with an average 53.1 excess narcotic pills per patient. Adjusting prescribing patterns to match patient narcotic usage could reduce the excess narcotic pills following TKA.

Intraoperative Comparison of Measured Resection and Gap Balancing Using a Force Sensor: A Prospective, Randomized Controlled Trial.

BACKGROUND: For establishing femoral component position, gap-balancing (GB) and measured resection (MR) techniques were compared using a force sensor. METHODS: Ninety-one patients were randomized to undergo primary total knee arthroplasty using either MR (n = 43) or GB (n = 48) technique using a single total knee arthroplasty design. GB was performed with an instrumented tensioner. Force sensor data were obtained before the final implantation. RESULTS: GB resulted in greater range of femoral component rotation vs MR (1.5° ± 2.9° vs 3.1° ± 0.5°, P < .05) and posterior condylar cut thickness medially (10.2 ± 2.0 mm vs 9.0 ± 1.3 mm) and laterally (8.5 ± 1.9 mm vs 6.4 ± 1.0 mm). Force sensor data showed a decreased intercompartmental force difference at full flexion in GB (.8 ± 2.3 vs 2.0 ± 3.3u, 1u ≈ 15 N, P < .05). CONCLUSION: GB resulted in a greater range of femoral component rotation and thicker posterior condylar cuts resulting in an increased flexion space relative to MR. Intercompartmental force difference trended toward a more uniform distribution between full extension and full flexion in the GB vs MR group.

Impact of Femoral Stem Design on Failure After Anterior Approach Total Hip Arthroplasty.

BACKGROUND: An increased rate of complications related to femoral component failure has been described with less invasive total hip arthroplasty (THA). This study evaluated the incidence of femoral complications associated with the direct anterior approach for THA. METHODS: Retrospective review was performed of the initial 1120 consecutive patients who underwent direct anterior THA by 2 surgeons. RESULTS: A total of 899 patients (80.3%) had a 2-year follow-up (range, 2-8 years). Complications within 90 days occurred in 20 patients (1.8%): 10 calcar fractures, 1 greater trochanter fracture, 1 canal perforation, 3 hematomas, 2 dislocations, 2 superficial, and 1 deep infection. Nine patients (1%) underwent revision: 5 for aseptic femoral loosening (0.55%), 1 for periprosthetic joint infection, 1 for dislocation, 1 for hip flexor irritation, and 1 for a damaged polyethylene liner. Of the 5 patients with aseptic femoral loosening, 3 had a short, mediolateral tapered stem, 1 cemented stem, and 1 S-ROM stem placed to bypass a canal perforation. There were no revisions for aseptic loosening in the collared, fully hydroxyapatite (HA)-coated compaction broached or triple tapered proximal fit and fill stem designs (70.6% of all stems). Revision rate for femoral loosening was significantly higher for tapered wedge over HA-coated, compaction broached stems (P < .005). CONCLUSION: Pain and function improved predictably with a 0.55% rate of femoral loosening at 2-year follow-up. Among collared, fully HA-coated and triple taper fit and fill femoral stems, there were no instances of revision for aseptic loosening vs 3 in the short stem, collarless mediolateral tapered group.

Mechanical comparison of iliosacral reconstruction techniques after sarcoma resection.

BACKGROUND: Reconstruction of iliosacral defects following oncologic resection is a difficult clinical problem associated with a high incidence of failure. Technical approaches to this problem are heterogeneous and evidence supporting specific techniques is sparse. Maximizing construct stability may improve union rates and functional outcomes. The purpose of this study is to compare construct stiffness, load to failure, and mechanism of failure between two methods of iliosacral reconstruction in an ex-vivo model to determine if either is mechanically superior. METHODS: Eight third-generation composite pelves reconstructed with a plate-and-screw technique were tested against seven pelves reconstructed with a minimal spinal instrumentation technique using axial loading in a double-leg stance model. FINDINGS: The pelves from the plate group demonstrated higher stiffness in the direction of applied load (102.9 vs. 66.8N/mm; p=0.010) and endured a significantly larger maximum force (1416 vs. 1059N; p=0.015) than the rod group prior to failure. Subjectively, the rod-reconstructed pelves were noted to be rotationally unconstrained while pivoting around their single point-of fixation in each segment leading to earlier failure. INTERPRETATION: Plate-reconstruction was mechanically superior to spinal instrumentation in the manner performed in this study. More than one point of fixation in each segment should be achieved to minimize the risk of rotational deformation.

Ten Year Follow-Up of Gap Balanced, Rotating Platform Total Knee Arthroplasty in Patients Under 60 Years of Age.

68 patients (91 primary total knee arthroplasties) were evaluated at a mean 10-year, minimum 5 year follow up in patients younger than sixty years of age utilizing the gap balanced, rotating platform design. Follow up assessment included implant survivorship, adverse events, x-rays, Knee Society rating system and clinical evaluation. Three revisions were performed with only one for aseptic loosening at 45 months. Two manipulations were performed in the early postoperative period. Survivorship of the rotating platform, gap balanced knee was 96.7% using surgical revision for any reason and 98.9% using aseptic loosening as endpoints. The rotating platform design using the gap balancing technique in young patients had excellent survivorship at 10-year mean follow up.

The role of margins in extremity soft tissue sarcoma.

For extremity soft tissue sarcomas, limb salvage is now standard of care. The extent of surgical margins is balanced with functionality of the resected limb. Although negative margins are the goal, the necessary width is unclear. Additional considerations for margin adequacy include presence of anatomic barriers such as fascia and periosteum, proximity of critical structures, receipt of adjuvant and neoadjuvant therapies, and histologic subtype. Multidisciplinary team discussion is critical for treatment planning.

Taper design affects failure of large-head metal-on-metal total hip replacements.

BACKGROUND: Large-head metal-on-metal (MoM) hip arthroplasties have demonstrated poor survival. Damage at the taper-trunnion junction is a contributing factor; however, the influence of junction design is not well understood. QUESTIONS/PURPOSES: (1) Does taper type affect fretting, corrosion, and volumetric wear at the junction? (2) Do taper types have different wear patterns? (3) Does larger offset or head diameter increase fretting, corrosion, and wear? (4) Is the extent of fretting and corrosion associated with earlier failure? METHODS: Taper damage in 40 retrieved heads was subjectively graded for fretting and corrosion, and wear was determined with high-resolution confocal measurement. Taper types (11/13, 12/14, and Type 1) differed by angle, distal diameter, and contact length; Type 1 were thinnest and 11/13 had longer contact lengths. RESULTS: Fretting scores were higher in 11/13 than in Type 1 tapers. Volumetric wear and wear rates did not differ among types. Uniform, circumferential, and longitudinal wear patterns were observed in all types, but fretting, corrosion, and wear did not differ among the patterns. Head diameter and lateral offset did not correlate with fretting, corrosion, or wear. No correlation was found between fretting, corrosion, or wear and length of implantation. CONCLUSIONS: In general, thicker tapers with longer contact lengths were associated with greater fretting scores, whereas no relationship was found among the three designs for corrosion scores or volumetric wear. This finding suggests that trunnion diameter and engagement length are important factors to consider when improving taper-trunnion junction design.

What causes unexplained pain in patients with metal-on metal hip devices? A retrieval, histologic, and imaging analysis.

BACKGROUND: Adverse tissue reactions associated with metal-on-metal (MOM) hips are common in resurfacing and total hip arthroplasty (THA) designs. The etiology of these reactions in painful, well-positioned arthroplasties is inconsistently described. QUESTIONS/PURPOSES: The purposes of this study were to compare the (1) articular wear rates; (2) histologic findings; (3) synovial response on MRI; and (4) graded intraoperative tissue damage between well-positioned, MOM hips revised for unexplained pain and MOM hips revised for other reasons and to (5) determine whether the presence of a taper junction on a MOM articulation affects these four parameters in unexplained pain. METHODS: We retrospectively studied 88 patients (94 hips) who had undergone revision of either a hip resurfacing or a large-head (> 36 mm) THA. Thirty-five hips revised for unexplained pain were compared with a control group of 59 hips revised for other causes. Articular wear was measured using three-dimensional contactless metrology and histologic analysis was performed using the aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) score. Preoperative MRI was performed on 57 patients to determine synovial volumes and thicknesses. Tissue damage was graded from intraoperative reports. RESULTS: Articular wear rates in the unexplained pain group were lower than in the control group (median 2.6 µm/year versus 12.8 µm/year, p < 0.001). Sixty-six percent of patients in the unexplained pain group had histologic confirmation of ALVAL compared with 19% in the control group (p < 0.001). The synovial thickness on MRI was higher in the unexplained pain group (p = 0.04) and was highly predictive of ALVAL. Severe intraoperative tissue damage was noted in more cases in the unexplained pain group (p = 0.01). There were no differences in articular wear, histology, MRI, and tissue damage between resurfacings and THAs revised for unexplained pain. CONCLUSIONS: Unexplained pain in patients with well-positioned MOM hips warrants further investigation with MRI to look for features predictive of ALVAL. Tissue destruction in these cases does not appear to be related to high bearing wear or the presence of a taper.

Laser scanning as a useful tool in implant retrieval analysis: a demonstration using rotating platform and fixed bearing tibial inserts.

Objective methods for analyzing arthroplasty retrieval implants are needed. To address this, we used a readily available laser scanner to analyze damage deviations between cohorts of rotating platform and fixed bearing inserts previously analyzed using traditional, subjective retrieval analysis methods. We asked the following research questions: 1) Do articular surface deviations measured by the scanner correlate with the subjective damage scores? 2) Do articular surface deviations differ between inserts due to design differences? Correlations between deviations and damage scores were present in RP but not FB inserts. Seven different deviation patterns were present between the RP and FB inserts and were a function of design. In conclusion laser scanning was found to be a useful objective tool for analyzing arthroplasty retrievals.

Surgical technique: Iliosacral reconstruction with minimal spinal instrumentation.

BACKGROUND: Posterior pelvic ring reconstruction can be challenging and controversial. The choice regarding whether to reconstruct and how to reconstitute the pelvic ring is unclear. Many methods provide stability but often are technically difficult and require excessive dissection. DESCRIPTION OF SURGICAL TECHNIQUE: This unique reconstructive technique uses the anterior aspect of the iliac crest with its attached muscle pedicle to provide a biologic scaffold for healing. The construct is secured with pedicle screws into the posterior column and S1 vertebral body with a spinal rod locked in compression. No additional fixation is used proximally into the lumbar spine. The iliac crest remains attached to the gluteus medius, allowing potential abductor function. METHODS: We retrospectively reviewed six patients who underwent iliosacral resection with this reconstruction. The mean age of the patients was 41 years. Complications were recorded. One patient died 6 months postoperatively. Musculoskeletal Tumor Society 1993 (MSTS '93) score and Toronto Extremity Salvage Score (TESS) were obtained at a minimum 1-year followup in five patients. Healing was assessed radiographically. The minimum followup was 6 months (median, 33 months; range, 6-53 months). RESULTS: The mean MSTS '93 score was 72% and mean TESS was 66. All posterior column graft sites healed. At last followup, four of the five surviving patients had a stable pseudarthrosis at the proximal sacral site. One patient had a local recurrence and experienced failure of instrumentation without collapse or rotation of the hemipelvis 3 years postoperatively. CONCLUSIONS: This technique provides a simple way to reconstruct the pelvic ring after iliosacral resection with clinical outcomes comparable to those for other methods. The method is a potential alternative for reconstruction of the posterior pelvic ring after resecting the ilium although reliable healing of the sacral site needs to be improved.

Periacetabular osteotomy and combined femoral head-neck junction osteochondroplasty: a minimum two-year follow-up cohort study.

BACKGROUND: Proximal femoral deformities and overcorrection of the acetabulum both can result in secondary femoroacetabular impingement and suboptimal clinical results after periacetabular osteotomy. The purpose of the present study was to determine the rate of complications, the need for reoperations, radiographic correction, and hip function among patients who underwent periacetabular osteotomy and combined femoral head-neck osteochondroplasty as compared with those who underwent periacetabular osteotomy alone. METHODS: Patients who underwent periacetabular osteotomy with or without osteochondroplasty of the femoral head-neck junction were evaluated retrospectively after a minimum duration of follow-up of two years. We compared the two groups with regard to the modified Harris hip score, radiographic correction, complications, and reoperations. RESULTS: Forty patients (forty hips) who underwent periacetabular osteotomy in conjunction with a femoral head-neck osteochondroplasty were compared with forty-eight patients (forty-eight hips) who underwent an isolated periacetabular osteotomy. Patients were evaluated after a mean duration of follow-up of 3.4 years (range, 2.0 to 9.7 years). Preoperatively, the modified Harris hip score (and standard deviation) was 64.3 ± 13.2 for the study group and 63.2 ± 13.4 for the comparison group. At the time of the latest follow-up, the modified Harris hip score was not significantly different between the study group and the comparison group (p = 0.17). Patients demonstrated equivalent preoperative deformities and postoperative acetabular radiographic parameters. There was a significant decrease in the alpha angle and improvement in head-neck offset in the study group. There was one reoperation for secondary impingement and/or labral pathology in the study group, compared with four reoperations in the comparison group. There were no adhesions requiring surgery, femoral neck fractures, instances of osteonecrosis, or increases in heterotopic ossification in the study group. CONCLUSIONS: Femoral head-neck junction osteochondroplasty performed concurrently with a periacetabular osteotomy for the treatment of symptomatic acetabular dysplasia and associated femoral head-neck junction deformities is not associated with an increased complication rate. This combined procedure provides effective correction of associated femoral head-neck deformities and produces similar early functional outcomes when compared with isolated periacetabular osteotomy. LEVEL OF EVIDENCE: Therapeutic Level III.

Osseous remodeling after femoral head-neck junction osteochondroplasty.

UNLABELLED: Femoral head-neck junction osteochondroplasty is commonly used to treat femoroacetabular impingement, yet remodeling of the osteochondroplasty site is not well described. We therefore describe bony remodeling at the osteochondroplasty site and analyze clinical outcomes and complications associated with femoral osteochondroplasty. We retrospectively reviewed 135 patients (150 hips) who underwent femoral head-neck osteochondroplasty combined with hip arthroscopy, surgical hip dislocation, periacetabular osteotomy, or proximal femoral osteotomy. The minimum clinical followup was 10 months (mean, 22.3 months; range, 10-65 months). We assessed the femoral-head neck offset, head-neck offset ratio, alpha angle, and cortical remodeling. We used the Harris hip score to determine hip function. We observed an increase in the head-neck offset, offset ratio, and decrease in the alpha angle postoperatively and at latest followup. Ninety-eight of 113 (87%) hips had partial or complete recorticalization at the osteochondroplasty site. The mean Harris hip score improved from 64 to 85. We excised heterotopic bone in one hip. There were no femoral neck fractures. The deformity correction achieved with femoral head-neck osteochondroplasty is maintained and recorticalization occurs in the majority of cases during the first two years. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Knee pain after tibial nailing: the role of nail prominence.

UNLABELLED: We analyzed the relationship between knee pain after tibial nailing and nail prominence. We identified 70 patients in our trauma registry with healed fractures initially treated with intramedullary nails. Subjective pain and function were measured with visual analog pain scales and Lysholm knee scores at a mean of 20 months after fracture. These scores were compared with nail prominence measured on postoperative radiographs. More than 49% of patients had knee pain. Subjective knee pain was more common in women and patients with a smaller plateau width. Anterior nail prominence was associated with increased pain at rest. Patients with superior nail prominence had increased pain with kneeling and walking. Nail prominence correlated with increased knee pain. We think surgeons can decrease, but not eliminate, the severity of knee pain after tibial nailing by burying the tip of the nail as reflected on lateral radiographs. LEVEL OF EVIDENCE: Prognostic Study, Level II-1 (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.

Measurement of morphologic changes induced by trauma with the use of coherence tomography in porcine vocal cords.

BACKGROUND AND OBJECTIVE: To evaluate the ability of optical coherence tomography (OCT) (a noncontact, high-resolution imaging technique that generates detailed cross-sectional images of tissue structure) to image and document acute response to trauma in the larynx. MATERIALS AND METHODS: Porcine larynges were dissected to expose the vocal cords. Vocal cords were imaged with 1310 nanometer (nm) light source with a bandwidth of 75 nm at 1 frame/second (s). Vocal cord injuries were simulated by applying topical phenolic acid, injecting titanium dioxide into the submucosa, and carbon dioxide laser irradiation. RESULTS: The epithelium, basement membrane, and lamina propria were clearly delineated, and the effect of each intervention could be monitored as lesions progressed. The OCT image corresponded closely with histology. CONCLUSION: OCT is a powerful imaging tool with the potential for use in real time and has potential for multiple clinical applications in the larynx.