Gehron Treme

Comprehensive Reconstruction of the Lateral Ankle for Chronic Instability Using a Free Gracilis Graft

Purpose: The purpose of this retrospective study was to assess the results of a novel surgical technique for the treatment of chronic lateral ankle instability using both a direct repair of the anterior talofibular ligament and a free gracilis tendon transfer to reconstruct anatomically the anterior talofibular and calcaneofibular ligaments. Methods: Between December 1998 and February 2002, 28 patients (29 ankles) underwent an anatomic reconstruction of the lateral ankle ligaments for chronic ankle instability. Patients returned for a clinical and radiologic follow-up evaluation at an average of 23 months following surgery (range, 12–52 months). Outcomes were assessed by comparison of preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores and visual analog pain scores as well as a postoperative Karlsson score. A subjective self-assessment rating was also obtained. All patients underwent preoperative and postoperative radiographic assessment including talar tilt and anterior drawer stress radiographs. Results: Twenty-eight patients (29 ankles) (100%) returned for final evaluation. Good or excellent outcome was noted on patient subjective self-assessment, pain scores, AOFAS, and Karlsson scores at final follow-up in all patients. Ankle range of motion was not affected by lateral ankle reconstruction. The talar tilt was reduced from a mean of 13° to 3° (p < .0001) and the anterior drawer was reduced from a mean of 10 mm to 5 mm (p < .0001) by the lateral ankle ligamentous reconstruction. Conclusion: In the present study, lateral ankle reconstruction with a direct anterior talofibular ligament repair and free gracilis tendon graft augmentation resulted in a high percentage of successful results, excellent ankle stability with a minimal loss of ankle or hindfoot motion, and marked reduction of pain at an average follow-up of almost 2 years.

Hamstring Graft Size Prediction A Prospective Clinical Evaluation

Background Recently we retrospectively collected clinical data to predict hamstring graft diameter. Prospective data collection will improve and further define prediction of hamstring graft size. Hypothesis Clinical anthropometric data can be used to predict hamstring graft size. Study Design Cohort study (prevalence); Level of evidence, 1. Methods Fifty consecutive patients with anterior cruciate ligament deficiency scheduled for reconstruction using hamstring autograft were prospectively evaluated. Preoperatively we recorded height, weight, body mass index, age, gender, leg length, thigh length, shank length, bilateral thigh circumference, and Tegner score. Intraoperative measurements of both the gracilis and semitendinosus tendons were made, including absolute length before fashioning the graft and final diameter of the quadrupled graft using sizing tubes calibrated to 0.5 mm. Bivariate correlation coefficients (Pearson r) were calculated to identify relationships among clinical data and intraoperatively measured hamstring graft length and diameter. Results Strongest correlations for graft lengths were height and leg length measurements. Shorter persons with shorter leg, thigh, and shank lengths tended to have shorter gracilis and semitendinosus grafts. Likewise, the strongest correlations for graft diameter were weight and thigh circumference. Self-reported activity level and age did not correlate. Gender comparison revealed that women who were shorter, lighter, and had smaller body mass indices were more likely to have smaller graft diameters and shorter graft lengths. Conclusion Patients weighing less than 50 kg, less than 140 cm in height, with less than 37 cm thigh circumference, and with body mass index less than 18 should be considered at high risk for having a quadrupled hamstring graft diameter less than 7 mm. When separated by gender, small graft diameters are most likely in older, short, female subjects with small thigh circumferences or young, skinny, male subjects with small thigh circumferences and low body mass index. Common clinical measurements can be used for preoperative identification of patients at risk for insufficient graft tissue and would be useful for patient counseling and alternative graft source planning.

Tibial Tubercle-Trochlear Groove Distance: Defining Normal in a Pediatric Population

BACKGROUND The tibial tubercle-trochlear groove (TT-TG) distance is a useful tool in guiding surgical management for patients with recurrent lateral patellar instability. Current recommendations for tibial tubercle transfer are based on TT-TG distance thresholds derived from adult populations. Recurrent patellar instability, however, frequently affects children, but normal and pathological TT-TG values have not been established for pediatric patients. The objectives of this study were to (1) confirm that magnetic resonance imaging (MRI) measurements for TT-TG distance in a pediatric population are reliable and reproducible, (2) determine whether the TT-TG distance changes with age, (3) define normal TT-TG distances in a pediatric population, and (4) confirm that a subgroup of pediatric patients with patellar instability have higher TT-TG distances. METHODS Six hundred and eighteen MRIs were retrospectively collected for patients who were nine months to sixteen years old. Each MRI was measured twice in a blinded, randomized manner by each reviewer. Patient age, sex, knee laterality, magnet strength, underlying diagnosis, and pertinent previous surgical treatments were all recorded separately from the measurements. MRIs that were unreadable and those of patients who had previous extensor mechanism surgery, preexisting deformity, or destructive neoplasms were excluded. RESULTS There was excellent intraobserver and interobserver reliability of TT-TG distance measurements. TT-TG distance was associated with the natural logarithm of age (p < 0.001). A percentile-based growth chart was created to demonstrate this relationship. The median TT-TG distance for patients without patellar instability in this pediatric population was 8.5 mm (mean and 95% confidence interval, 8.6 ± 0.3 mm). Patients with patellar instability had higher TT-TG distances (median, 12.1 mm; p < 0.001). TT-TG distance measured nearly 2 mm less on MRIs performed with a 3-T magnet than on those acquired with a 1.5-T magnet (p < 0.001). CONCLUSIONS TT-TG distance changes with chronologic age in the pediatric population. As such, we developed a percentile-based growth chart in order to better depict normal TT-TG distances in the pediatric population. Like many issues in pediatric orthopaedics, an age-based approach for directing surgical treatment may be more appropriate for skeletally immature individuals with recurrent lateral patellar instability.

Knee Articular Cartilage Repair and Restoration Techniques A Review of the Literature

Context: Isolated chondral and osteochondral defects of the knee are a difficult clinical challenge, particularly in younger patients for whom alternatives such as partial or total knee arthroplasty are rarely advised. Numerous surgical techniques have been developed to address focal cartilage defects. Cartilage treatment strategies are characterized as palliation (eg, chondroplasty and debridement), repair (eg, drilling and microfracture [MF]), or restoration (eg, autologous chondrocyte implantation [ACI], osteochondral autograft [OAT], and osteochondral allograft [OCA]). Evidence Acquisition: PubMed was searched for treatment articles using the keywords knee, articular cartilage, and osteochondral defect, with a focus on articles published in the past 5 years. Study Design: Clinical review. Level of Evidence: Level 4. Results: In general, smaller lesions (<2 cm2) are best treated with MF or OAT. Furthermore, OAT shows trends toward greater longevity and durability as well as improved outcomes in high-demand patients. Intermediate-size lesions (2-4 cm2) have shown fairly equivalent treatment results using either OAT or ACI options. For larger lesions (>4 cm2), ACI or OCA have shown the best results, with OCA being an option for large osteochondritis dissecans lesions and posttraumatic defects. Conclusion: These techniques may improve patient outcomes, though no single technique can reproduce normal hyaline cartilage.

Injury Patterns at a Large Western United States Ski Resort With and Without Snowboarders The Taos Experience

Background: Differences in injury patterns among alpine skiers and snowboarders have previously been recognized, and controversy remains about the safety implications that snowboarding may pose to a ski resort. A change of policy at Taos Ski Valley provides a unique and modern perspective on the effect that snowboarders have on ski resort injuries. Hypothesis: The addition of snowboarders to a large ski resort may result in a significant change in both the rate and pattern of injuries treated. Study Design: Descriptive epidemiology study. Methods: Patient records from the Mogul Medical Clinic at Taos Ski Valley were reviewed from the 2006-2007 ski season through the 2009-2010 season (approximately 2 years before and after snowboarding was allowed) and recorded for age, sex, diagnosis, body region, anatomic location, injury type, and sport (skiing, snowboarding). The total numbers of mountain visits for the time periods with and without snowboarding were used to determine injury rates. Results: The overall rate of persons injured increased from 206.7 per 100,000 mountain visits without snowboarders to 233.8 with snowboarders. The relative risk ratio was 1.131, also represented as a 13.1% increased risk of injury (IRI) (statistically significant; 95% CI, 3.5%-23.6%). Increases were seen in the rate of upper extremity injuries (IRI, 39.1%; 95% CI, 14.3-69.4) and head/neck injuries (IRI 30.8%; not significant), while lower extremity and trunk/pelvis injuries remained relatively constant. Distal radius fractures, closed head injuries, and acromioclavicular separations showed statistically significant increases with the addition of snowboarding. The most frequent injuries among snowboarders were distal radius fractures, wrist sprains, closed head injuries, and acromioclavicular separations. The most frequent injuries among skiers were anterior cruciate ligament tears, knee sprains, closed head injuries, and gastrocnemius tears. The median age of injured persons decreased from 39 years (range, 4-100 years) without snowboarders to 31 years (range, 4-99 years) with snowboarders, and this was significant. Approximately 45% of injured persons were female, and this did not change with the addition of snowboarders. Conclusion: In this study, there was a small but statistically significant increase in the likelihood of injury with the addition of snowboarding to a large ski resort. It is likely that factors such as younger demographic, elevated risk-taking behavior, or increased mountain crowding are involved. The difference in injuries is largely because of a significant increase in distal radius fractures, closed head injuries, and acromioclavicular separations. On mountain safety precautions such as widening of runs and streamlining of high traffic areas, training medical providers to recognize and treat sport-specific injuries, and promoting the use of wrist guards and helmets may be useful in reducing the effect that snowboarders have on ski resort injuries.

Incidence of Associated Knee Injury in Pediatric Tibial Eminence Fractures

Our intent is to review pediatric tibial eminence fractures treated at a Level I Trauma Center and to note the incidence of associated knee pathology. All pediatric patients treated operatively for a tibial eminence fracture over a 10-year period were identified. A chart review was performed to identify patient demographics, injury pattern, presence of associated pathology, and magnetic resonance imaging (MRI) findings. In our series of 20 pediatric tibial eminence fractures, 6 patients had associated meniscal tears. Meniscal tears occurred more commonly in type III injuries (5 of 13) than type II injuries (1 of 6). Two patients sustained associated ligamentous injury; there were no patients with associated chondral defects. A displaced pediatric tibial eminence fracture is a relatively infrequent injury. The incidence of associated meniscal injury in our study was 30%, and associated ligamentous injury was uncommon. Arthroscopic evaluation before definitive treatment of displaced tibial eminence fractures should be considered given the associated incidence of meniscal tears. MRI does not appear to provide additional information if arthroscopic treatment is pursued. This study is level IV, case series.

Distal tibia allograft for glenohumeral instability: does radius of curvature match?

BACKGROUND A distal tibia osteochondral allograft is a potential graft option for glenoid reconstruction because the distal tibia may have a similar radius of curvature (ROC) as the glenoid. This study evaluated ROC mismatch as measured on computed tomography (CT) scans between the glenoid, distal tibia, and humeral head. METHODS Bilateral CT images were formatted for 10 decedents from the Office of the Medical Investigator database, giving 20 specimens per anatomic location. The ROCs of the glenoid, distal tibia, and humeral head were measured. A statistical model was generated to assess ROC mismatch of randomly paired distal tibias and glenoids. RESULTS The mean ± standard deviation ROC was 2.9 ± 0.25 cm for the glenoid, 2.3 ± 0.21 cm for the distal tibia, and 2.5 ± 0.12 cm for the humeral head. No differences were found in laterality, intraobserver, or interobserver measurements. The least-squares difference in the ROC between the glenoid and tibia was 0.57 cm, glenoid and humerus was 0.40 cm, and humerus and tibia was 0.17 cm. Only 22% of randomly paired distal tibias and glenoids had a difference in ROC of 0.3 cm or less. CONCLUSION CT measurement of the ROC of the glenoid, distal tibia, and humeral head is reliable and reproducible. The probability of obtaining a random distal tibia allograft with a similar ROC to the glenoid is low. Obtaining ROC measurements of the injured glenoid and the distal tibia allograft specimen before use for glenoid reconstruction may be useful.

Surgical treatment of medial instability of the knee.

Medial collateral ligament (MCL) injuries are commonly seen in orthopedic practice. Most MCL injuries are isolated and can be treated nonsurgically with focus on brace protection of the ligament, range of motion, gait training, and relatively quick return to full activity. A subset of MCL injuries, however, requires operative treatment. It is critical to identify patients with medial instability and develop an operative plan that will restore stability and function to the injured knee. Many MCL reconstruction and repair techniques have been described, and improvement in outcomes with improvement of technique remains an area of great interest. This review discusses several MCL reconstruction options and outlines the authors’ preferred MCL reconstruction technique.

Evaluation of the Tibial Tubercle to Posterior Cruciate Ligament Distance in a Pediatric Patient Population

Background: Evaluation of distal extensor mechanism alignment continues to evolve in children with patella instability. Prior studies support the use of the tibial tubercle to trochlear groove (TT-TG) distance but limitations exist for this measurement including: changes in the TT-TG distance with knee flexion, difficulty with finding the deepest part of a dysplastic trochlea, and limitations regarding identification of the site of the anatomic abnormality. The tibial tubercle-posterior cruciate ligament (TT-PCL) distance has been introduced as an alternative measure to address the shortcomings in the TT-TG distance by quantifying the position of the TT independent of the trochlea and with respect to the tibia only. The objectives of this study were to (1) confirm that TT-PCL measurements in the pediatric population are reliable and reproducible; (2) determine whether normal TT-PCL distance changes with age; and (3) compare TT-PCL distances in patients with and without patellar instability to assess its utility in the workup of pediatric patellar instability. Methods: All knee magnetic resonance imaging performed for patients from birth to 15.9 years of age at our institution between December 2004 and February 2012 were retrospectively collected (total 566). Eighty-two patients had patellar instability and 484 patients did not have patellar instability. Two magnetic resonance imaging reviewers measured TT-PCL distance on T2-weighted axial images in a blinded manner. Intraobserver and interobserver agreement was measured. Correlation between TT-PCL distance and age as well as group differences between mean TT-PCL distances was evaluated. Results: Intraobserver and interobserver agreement was excellent (0.93) and very good (0.80), respectively. The mean TT-PCL distance was 20.1 mm with a range of 5.8 to 32.1 mm. The mean age was 12.6 years with a range of 0.8 to 15.9 years. The average TT-PCL distance was 21 mm for the instability group and 19.9 mm for the control group. TT-PCL distance increased significantly as subject age increased; however, there was no significant measurement difference shown between the patellar instability group and the control group. Conclusions: TT-PCL distance increased with age in the pediatric population but did not correlate with recurrent patella instability in this pediatric cohort. Level of Evidence: Level III—diagnostic.

A Biomechanical Comparison of Knee Stability after Posterolateral Corner Reconstruction: Arciero vs. LaPrade

Objectives: The Posterolateral Corner (PLC) is an area of the knee that does not receive adequate research recognition despite its functionality and contribution to the overall stability of the knee. Until recently, its anatomy and biomechanics have been poorly understood which has led to the creation of multiple reconstruction methods. Two frequently used techniques are the Arciero and LaPrade reconstructions. Both have shown promising outcomes, but the two techniques have never been compared against each other from a biomechanical perspective. The objective of this study was to identify which reconstruction technique (Arciero vs. LaPrade) best restores stability to an isolated posterolateral corner (PLC) injury and injuries of the PLC which occur concurrently with injury to the tibiofibular ligament (tib-fib) and the anterior cruciate ligament (ACL), respectively. Methods: Ten matched paired fresh-frozen cadaveric specimens from mid femur to foot were used. The Semitendinosus, Gracilis, and Achilles tendons were harvested from each specimen to use as allografts for the corresponding reconstructions. Mechanical Testing: To examine the significance of PLC instability a custom made testing fixture was created to isolate and test for 10 Nm Varus Angulation (VA) and 5 Nm External Rotation (ER) at 0, 20, 30, 60, and 90 degrees of flexion about the knee joint. Data Acquisition: 8 Optitrack Motion Capture cameras were used to acquire VA and ER data through the use of 3 rigid body marker sets. The motion capture software recorded the initial and final positions of the marker sets under loading. Measures were taken of the intact knee, at post-sectioning of the PLC, and post-reconstruction (Arciero or LaPrade). Subsequently, half the specimens were subject to sectioning of the tib-fib ligament and half to sectioning of the ACL. Measures were collected of each. Data Analysis: Multivariate Analysis of Variance (MANOVA) was used to assess the mean differences over the five angles at each stage. The Wilks’ Lambda statistic and significance level of 5% were used to establish statistically significant differences. Results: Data from paired, intact knees were found to be statistically similar confirming that all subsequent tests would not be affected by specimen variabilities. Post-PLC sectioning data for both groups showed significant instability from intact data, but were not different from each other. Data analysis concluded that there was no statistically significant difference between the LaPrade and Arciero techniques post-reconstruction. Both techniques were able to regain >80% of the stability of the intact knee. Post-tib-fib sectioning, ER instability was increased for all Arciero reconstructions at 90º flexion (p=0.01). Additionally, VA instability was increased for Arciero reconstructions at all flexion angles, but not significantly. A positive post-hoc parallel profile test indicates that the post-tib-fib VA data may have been significant with a larger sample size. Sectioning the ACL showed no difference between the two techniques. Conclusion: The outcome measures of this study show no statistical differences between the Arciero and LaPrade techniques for VA and ER at varying degrees of knee flexion. Post-hoc tests showed that the LaPrade technique may be the preferred option when PLC injury is concurrent with injury to the tib-fib ligament.