Milbrandt, Todd A.

» Patients with neuromuscular spasticity about the hip with concomitant painful hip arthritis can be effectively treated with total hip arthroplasty, with excellent clinical outcomes and durable implant survivorship. » Certain subsets of patients in this population are at increased risk of dislocation, component loosening, and heterotopic ossification and are also prone to postoperative medical complications. » Strategies that may mitigate the risk of dislocation include using large femoral heads or dual-mobility articulations with cautious use of constrained liners, careful repairing of soft-tissue structures at the conclusion of the surgical procedure, and performing concomitant adductor and flexor tenotomies. In addition, the other common complications can be reduced by coordinating perioperative care with neurological and medical specialists and administering perioperative heterotopic ossification prophylaxis, most commonly in the form of nonsteroidal anti-inflammatory medications, if tolerated.

Vibrational characteristics of the bone are directly dependent on bone’s physical properties. In this paper, a vibrational method for bone evaluation is introduced. We propose a new type of quantitative vibro-acoustic method based on acoustic radiation force of ultrasound for bone characterization in patients with fracture. In this method, we excite the clavicle and ulna by an ultrasound radiation force (URF) pulse. The URF pulse induces vibrations in the bone, resulting in an acoustic wave that is measured by a hydrophone placed on the skin. The resulting acoustic signals were used for wave velocity estimation based on cross-correlation technique. To further separate different vibration characteristics, we adopt a variational mode decomposition (VMD) technique to decompose the received signal into an ensemble of band-limited intrinsic mode functions, which allows analyzing the acoustic signals in terms of their constitutive components. We conducted a prospective study that included a total of 15 patients, 12 with clavicle fractures and 3 with ulna fractures. The contralateral intact bones were used as control. Statistical analysis demonstrated that fracture bones can be differentiated from intact bone with a detection probability of 80%. Also, we introduce a “healing factor” that quantifies the progress of healing in clavicle bones. Statistical analysis showed that healing factor can track the progress of healing in clavicle in 80% of fractures.

Background: Foot abduction orthoses (FAO) are believed to decrease recurrence following treatment of congenital talipes equinovarus (CTEV) as described by Ponseti. The purpose of this project is to examine the outcomes of FAO bracing following treatment by the Ponseti method in a cohort of idiopathic CTEV patients. Methods: After IRB approval, a cohort of patients aged 3 to 46 days with idiopathic CTEV was identified in a previous prospective study of brace compliance by family report and sensor. Dimeglio score and family demographic information were collected. Initial treatment was by the Ponseti method, with or without Achilles tenotomy. Following correction, patients had three months of full-time FAO bracing during which parents kept a log of compliance. Patients were followed until recurrence (need for further treatment) or age 5. Results: In total, 42 patients with 64 affected feet met the above criteria and were included in the final analysis. Twenty-six feet (40%) went on to develop recurrence requiring further treatment, including casting, bracing, or surgery. Because of poor tolerance of the original FAO, 20 feet were transitioned to an alternative FAO, and 14 of these (70%) went on to recur (P<0.01). The casting duration (P=0.02) had a statistically significant relationship to recurrence. Patients who were casted for 9 weeks or more had a higher rate of recurrence (57.1% vs. 27.8%; P=0.02). Age at treatment start, Dimeglio score, demographic factors, and compliance during full-time bracing, whether by report or sensor, did not show a significant relationship with recurrence. Conclusions: The study showed a statistically significant relationship between the difficulty of CTEV correction and the risk of recurrent deformity requiring treatment. This relationship could be used to provide prognostic information for patients’ families. Caregiver-reported compliance was not significantly related to recurrence. Level of Evidence: Level III—Prognostic Retrospective Cohort Study.

Background: Recent research has identified posterior tibial slope as a risk factor for anterior cruciate ligament (ACL) injury, due to increased forces on the ACL with this tibial anatomy. Biomechanical studies suggest that altering a patient’s posterior tibial slope may lower the risk of ACL injury. Due to the presence of an open physis, guided growth may be used to reduce the posterior tibia slope in this high risk skeletally immature population. The primary purpose of this study was to quantify and measure the posterior tibial slope in pediatric knees. Methods: Forty-four pediatric knee CT scans were analyzed using OsiriX, an imaging software. Specimens analyzed were between the ages of 2 and 12 years of age. The proximal tibial slope for each specimen was measured on CT scan sagittal slices at 2 locations: 1) At the medial tibial plateau at the mid region of the medial femoral condyle, as determined on a coronal slice through the femoral condyle; 2) At the lateral tibial plateau at the mid region of the lateral femoral condyle, as determined on the coronal slice through the femoral condyle. The measurement of the posterior tibial slope was determined by placing two lines parallel to the diaphysis of the tibia, one located in the middle of the diaphysis and one located at the most posterior aspect of the diaphysis. The most proximal aspect of both the medial and lateral tibial plateau were then identified and angle measurements were taken in reference to the parallel lines. The angle measurements were plotted graphically by age in order to account for variability in development within age groups. The anterior medial and lateral tibia plateau widths were measured by identifying the mid region of the respective plateaus. From this point, the distance between the top of the tibial plate and the physis was measured. Results: The average posterior tibial slope angle for the medial and lateral tibial plateau were (5.53° ± 4.17°) and (5.95° ± 3.96°) respectively. Independent samples t-test and ANOVA indicate the difference between the posterior tibial slope angle of the medial and lateral tibial plateau were not statistically significant (p < 0.05). When plotted graphically by age, a slight negative trend between age and posterior tibial slope was identified. As age increases, the medial and lateral posterior tibial slope decreases. The mean anterior medial tibial plateau width and lateral tibial plateau width were .99 cm and 1.19 cm respectively. Discussion/Conclusion: ACL primary and secondary injury occur at very high rates in the skeletally immature, especially in females at age 11 and older, and in males at age 13 and older. This data set offers some preliminary values for posterior tibial slope in patients without a history of ACL injury, allowing for comparisons to patients with ACL Injury. Increased tibial slope is a risk factor for ACL injury. In the skeletally immature, one option to alter the tibial slope is the use of guided growth with implants to slow the anterior growth of the proximal tibia, reducing the posterior slope of the tibia, and possibly lower the risk of ACL injury in this high-risk population. [Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Table: see text][Table: see text]

Background: Avulsion fractures involving the tibial eminence are considered equivalent in etiology to anterior cruciate ligament tears, however there is limited data comparing outcomes of adolescent patients undergoing surgical fixation of tibial eminence fractures to those undergoing anterior cruciate ligament (ACL) reconstruction. Purpose: The purpose of this study was to compare clinical outcomes, subsequent ACL injury rates, and activity levels between adolescent patients who underwent tibial eminence fracture fixation to patients with mid-substance ACL tears who required acute ligament reconstruction. Methods: This study included a group of patients with tibial eminence fractures treated with surgical fixation matched to a group of similar patients with ACL tears treated with reconstruction between the years of 2001 and 2015. Data regarding initial injury, surgical intervention, ACL/ACL graft injury rates, and physical examination findings were recorded. Clinical and functional outcomes were obtained using physical examination, IKDC subjective scores, Lysholm scores, and Tegner Activity levels. Results: Sixty patients with a mean follow-up of 57.7 (24-206) months were included. 20 patients (11 M:9 F) who underwent surgical fixation for tibial eminence fractures (TEF) with a mean age of 11.9 (7-15) years were matched to a group of 40 patients (23 M:17 F) who underwent ACL reconstruction for ACL tears with a mean age of 12.5 (8-15) years. The TEF group demonstrated significantly lower postoperative IKDC (TEF group: 94.0, ACL group: 97.2 (p=0.04)) and Lysholm scores (TEF group: 92.4, ACL group: 96.9 (p=0.02)). The TEF group returned to sport 121 days sooner (p<0.01), but there was no difference in postoperative Tegner scores (TEF group: 7.3, ACL group: 7.6 (p=0.16)). The TEF group demonstrated increased postoperative anterior laxity (p=0.02) and a higher rate of postoperative arthrofibrosis (p=0.04). There was no difference in subsequent ACL injury (p=0.41). Conclusion: Patients with tibial eminence fractures demonstrated lower mean clinical outcome scores compared to patients with ACL tears at minimum 2-year follow up. Additionally, they experienced more postoperative anterior laxity and had a higher rate of postoperative arthrofibrosis. There was no difference in subsequent ACL injury rate. The TEF group returned to sport sooner than the ACL group, but the postoperative activity level was similar.

Purpose: The goal of this study was to evaluate patient and surgical factors predictive of excellent functional and isokinetic test results 6-months following anterior cruciate ligament (ACL) reconstruction in a group of pediatric patients with open physes. Methods: We retrospectively reviewed the records of all patients 14 years of age or younger that underwent ACL reconstruction from 2000 to 2015. An excellent 6-month outcome was defined as greater than 85% in isokinetic strength and greater than 90% in functional tests when compared to the non-operative extremity. We then utilized univariate and multivariate statistical models to identify patient and/or surgical factors associated with excellent 6-month outcomes. Results: Eighty-six patients (46 male, 42 female) with open physes on preoperative radiographs were included in the study, with a mean age of 13.6 (range, 8.4-14.9), body mass index (BMI) of 22.1 (range, 15.6-36.0), Tegner activity score of 8.8 (6.0-9.0). Thirty-four patients (40%) met the criteria for the excellent 6-month group, which left 52 (60%) in the delayed 6-month group. In univariate analysis, no single preoperative factor correlated with excellent 6-month outcome. The two groups were statistically similar in terms of age, BMI, time to surgery, preoperative arc of motion, presence of concomitant meniscal tear, cartilage damage, graft size, use of a nerve block or tourniquet, operative time, and tourniquet time. Use of a nerve block trended towards delayed outcomes (p = 0.051). Conclusion: Children undergoing ACL reconstruction only have a 40% chance of achieving an excellent rehabilitation result at 6 months. We found no statistically significant patient or surgical characteristics that could predict this outcome. Utilizing a nerve block is a factor which will need to be further evaluated. Significance: Studies in the adult population have identified preoperative patient and surgical factors associated with excellent 6-month isokinetic and functional test results. This pediatric cohort did not find similar results as many of these children were young, healthy and fit. However, the variability of the outcome casts doubts on applying adult rehabilitation protocols to children.

Introduction: It is unknown whether functional and isokinetic testing at 6 months following ACL reconstruction in patients with open-physes correlates with longer term outcomes. The purpose of this study was to compare subsequent ACL rupture risk, knee function, and activity level in patients with open-physes who had excellent 6-month testing to those who did not. Methods: Between the years of 2000 and 2015, 86 patients with open-physes underwent ACL reconstruction and had functional and isokinetic testing performed at 6-months post-operatively. Thirty-four (40%) tested in the excellent range in all categories of both functional and isokinetic testing and were labeled the excellent group. The remaining 52 (60%) patients were labeled the delayed testing group. Data regarding patient, injury, and surgical characteristics were retrospectively collected. The rate of second ACL injury as well as clinical outcome scores were collected postoperatively. Results: Graft rupture rate was 23.4% (n = 8) in the excellent group and 15.4% (n = 8) in the delayed group (p = 0.51). In the excellent group, 20.5% (n = 7) had a contralateral ACL tear versus 11.5% (n = 6) in the delayed group (p = 0.40). Five patients in the excellent group and 4 patients in the delayed group sustained both graft failure and contralateral ACL tear. The overall prevalence of second ACL injury was 29% in the excellent group and 23% in the delayed group. The delayed group returned to sport at an average of 8.8 months whereas the excellent group returned at an average of 6.6 months (p < 0.01). At mean follow up of 3.59 years, the excellent group had a higher Tegner activity level (8.9 versus 8.3) than the delayed group (p < 0.02). Conclusion: Pediatric patients with open-physes who had excellent isokinetic strength and functional testing 6-months postoperatively returned to sport sooner than those who did not. There was no statistical difference in either graft failure or contralateral ACL disruption between these groups. However, both groups had unacceptably high rates of second ACL injury (29% for the excellent group and 23% for the delayed group). Significance: Excellent 6 month return of strength and function was not protective of subsequent ACL disruption, the rate of which remains dismal within this pediatric population. Development of more sensitive functional measures for children could help to change these poor outcomes and guide clinicians when to allow return to sport.

Background Adductor canal block (ACB) is an alternative method to femoral nerve block (FNB) for post-operative analgesia for anterior cruciate ligament reconstruction (ACLR) in pediatric and adolescent patients. Prior studies have suggested that FNB is associated with persistent strength deficits at 6 months after ACLR in this population. Proponents of the ACB consider that this method may result in a decreased incidence of quadriceps strength deficits during post-operative rehabilitation. The purpose of this study was to compare knee strength and function at 6 and 9 months after ACLR in pediatric and adolescent patients who received FNB versus ACB peri-operatively. Methods Patients 18 years or younger who underwent primary ACLR between 2002 and 2017 at a single institution were identified. ACLR was performed with either a patellar tendon autograft or hamstring autograft. A transphyseal ACLR was performed in patients with open physes. All patients participated in a comprehensive rehabilitation program which included isokinetic strength testing and functional testing at 6 and/or 9 months postoperatively. Patients were excluded if they underwent multiligamentous knee reconstruction, concomitant cartilage restoration procedures, did not receive perioperative FNB or ACB, or if they did not complete isokinetic strength and functional testing at 6 or 9 months. The included cohort was separated into FNB group and ACB group for comparison. Isokinetic extension and flexion strength deficits and functional deficits in vertical jump, single hop, and triple hop between the two groups were compared at both time points. A strength deficit of 15% or less and a functional deficit of 10% or less compared to the contralateral side were considered satisfactory. Univariate analysis was performed to assess for differences in patient demographics and surgical variables. A 1:1 matched subgroup analysis between the two groups was performed to account for possible differences in outcomes associated to graft types, concomitant meniscus repair, and BMI. Results Of the 240 patients identified, 85 patients (64 FNB, 21 ACB) with a mean age of 15.9 years (Range: 11-18) met inclusion criteria for comparison at 6 months and 76 patients (40 FNB, 36 ACB) with a mean age of 15.5 years (Range: 12-17) met inclusion criteria for comparison at 9 months. Univariate analysis showed significantly greater deficits at 6 months in the FNB with respect to fast isokinetic flexion strength (7.7% vs. -4.9%; p = .03). There were no differences in slow isokinetic flexion (10.5% vs. 6.8%; p = .79) and fast isokinetic extension (11.9% vs. 13.9%; p = .68) strength deficits between the groups. There were clinically relevant greater deficits in the FNB group with respect to slow isokinetic extension (19.3% vs. 12.0%; p = .24), but this did not reach statistical significance. This clinical difference in satisfactory scores between the groups with respect to slow isokinetic extension was accentuated with the 1:1 matched outcome trial (23.9% vs. 12.1%; p = .20). With respect to function, there were no differences in deficits for vertical jump (8.4% vs. 4.3%; p = .55), single hop (7.4% vs. 9.3%; p = .65), or triple hop (6.0% vs. 7.1%; p = .77) between the two groups. Univariate analysis showed significant greater deficits at 9 months in the FNB with respect to slow isokinetic flexion strength (9.6% vs. 0.4%; p = .01). There were no differences in fast isokinetic flexion (-0.2% vs. 0.7%; p = .87) and fast isokinetic extension (6.0% vs. 2.7%; p = .51) strength deficits between the groups. There were clinically relevant greater deficits in the FNB group with respect to slow isokinetic extension (17.3% vs -14.0%, p = .19), but this did not reach statistical significance. With respect to function, there were no differences in deficits for vertical jump (5.2% vs. 6.5%, p = .85), single hop (7.7% vs. 6.2%; p = .79), or triple hop (1.9% vs. 3.9%; p = .35) between the two groups. Conclusion Because previous studies have shown a significant delay in return of strength with FNB, ACB began to be employed at our center for post-operative pain control following ACLR in pediatric and adolescent patients. This study showed that pediatric and adolescent patients treated with FNB as a method of post-operative analgesia after ACLR had significantly greater deficits in fast isokinetic flexion at 6 months and slow isokinetic flexion at 9 months compared to those who received ACB. These differences may or may not have clear clinical relevance. However, patients treated with FNB showed clinically relevant greater deficits in slow isokinetic extension strength at 6 and 9 months postoperatively compared to those who received ACB if 85% strength return is used as criteria to return to sport. Pediatric and adolescent patients could benefit from undergoing perioperative analgesia with ACB instead of FNB, but comparison between these two methods of regional anesthesia may require a prospective trial. Level of Evidence Retrospective cohort study, Level IV [Table: see text][Table: see text]

Background: In skeletally immature patients, the MPFL femoral origin as near or below the physis in most age groups. Although MPFL reconstruction procedures that employ patella drill holes facilitate graft tension adjustment, recent research demonstrates significant risk of patella fractures if patella drill holes are utilized. For this reason, the use of patella drill holes may be best avoided, but this technical alteration makes graft tension fixation more challenging during MPFL reconstruction in the skeletally immature. The purpose of this study was to evaluate the feasibility of developing a physeal respecting femoral drill for the MPFL origin with surgical model simulation, which allows for graft tensioning during MPFL reconstruction. Methods: Pediatric cadaveric specimens (n=5) were dissected by a group of fellowship trained pediatric and/or sports orthopaedic surgeons, and these specimens were then subject to CT Scans for the creation of 3D models. Specimens, aged 7, 9, 10, 11 and 11 years, were used to develop surgical simulations. CT Scans were loaded into Osyrix, converted to appropriate file structure, and then 3D models were loaded into Blender (Stichting Blender Foundation, Buikslotermeerplein 161, 1025 ETAmsterdam, the Netherlands). These models were used to evaluate 3D models of the knee, with placement of medial femoral condyle drill holes starting at the MPFL femoral origin, and entering the joint just anterior to the PCL femoral origin. The anatomic goals of the surgical simulation include: 1. Place drill hole at the MPFL origin on the femur. 2 Enter the intercondylar notch region of the femur anterior to the PCL origin allowing for arthroscopic visualization. 3. avoiding the articular cartilage on the medial femoral condyle. 4. Avoid the femoral physis throughout the course of drilling from the femoral MPFL Origin point to the entry location into the intercondylar notch. In the specimens, a full length drill hole was placed with either a 4 or 5 mm drill hole. Results: All specimens were subject to the surgical modeling and simulated drill hole placement. In each case, a drill hole was successfully placed meeting all the goals of the simulation: 1. Starting Point at MPFL, 2. Exit point anterior the PCL origin, 3. Exit point posterior to the articular cartilage, and 4. Avoidance of direct physeal injury. Figures 1 and 2. Conclusion: Setting graft tension during MPFL reconstruction is one of the significant technical challenges during MPFL reconstruction, and appropriate graft position and tension may be the most critical elements of successful MPFL reconstruction. Historically, graft tension has been set on the patella, using drill holes for the MPFL attachment point on the patella, but this technique has been associated with patella fractures. In order to allow for adjustment of graft tension on the femoral side of the MPFL graft during surgical reconstruction, a surgical simulation was developed to confirm the anatomic appropriateness and safety of placement of femoral drill holes which allow for adjustment of graft tension. This surgical simulation model confirms that MPFL femoral origin anatomy can be reproduced with injury to the physis, the PCL, or the articular cartilage of the femoral condyle. This drill hole and graft can be visualized arthroscopically and allow for appropriate graft tensioning during the procedure. [Figure: see text][Figure: see text]

Background: Avulsion fractures involving the tibial eminence are considered equivalent in terms of the cause to anterior cruciate ligament (ACL) tears; however, there are limited data comparing the outcomes of adolescent patients undergoing surgical fixation of a tibial eminence fracture (TEF) with those undergoing ACL reconstruction. Purpose: To compare the clinical outcomes, subsequent ACL injury rates, and activity levels between adolescent patients who underwent TEF fixation with patients with midsubstance ACL tears who required acute reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: This study included a group of patients with TEFs treated with surgical fixation matched to a group of similar patients with ACL tears treated with reconstruction between the years 2001 and 2015. Data regarding the initial injury, surgical intervention, ACL/ACL graft injury rates, and physical examination findings were recorded. Clinical and functional outcomes were obtained using a physical examination, the International Knee Documentation Committee (IKDC) subjective score, the Lysholm score, and the Tegner activity score. Results: Sixty patients with a mean follow-up of 57.7 months (range, 24-206 months) were included; 20 patients (11 male, 9 female; mean age, 11.9 years [range, 7-15 years]) who underwent surgical fixation for a TEF were matched to a group of 40 patients (23 male, 17 female; mean age, 12.5 years [range, 8-5 years]) who underwent reconstruction for ACL tears. The TEF group demonstrated significantly lower postoperative IKDC scores (TEF group, 94.0; ACL group, 97.2; P = .04) and Lysholm scores (TEF group, 92.4; ACL group, 96.9; P = .02). The TEF group returned to sport 119 days sooner ( P < .01), but there was no difference in postoperative Tegner scores (TEF group, 7.3; ACL group, 7.6; P = .16). The TEF group demonstrated increased postoperative anterior laxity ( P = .02) and a higher rate of postoperative arthrofibrosis ( P = .04). There was no difference in subsequent ACL injuries ( P = .41). Conclusion: Both groups demonstrated quality outcomes at a minimum 2-year follow-up. Patients with TEFs demonstrated lower mean clinical outcome scores compared with patients with ACL tears, but the differences were less than reported minimal clinically important difference values. Additionally, the TEF group experienced more postoperative anterior laxity and had a higher rate of postoperative arthrofibrosis. There was no difference in the rate of subsequent ACL injuries. The TEF group returned to sport sooner than the ACL group, but the postoperative activity levels were similar.