Caroline Park

Diagnostic Algorithm for Residual Pain After Total Knee Arthroplasty

Although total knee arthroplasty is a successful and cost-effective procedure, patient dissatisfaction remains as high as 50%. Postoperative residual knee pain after total knee arthroplasty, with or without crepitation, is a major factor that contributes to patient dissatisfaction. The most common location for residual pain after total knee arthroplasty is anteriorly. Because residual pain has been associated with an un-resurfaced patella, this review includes only registry data and total knee arthroplasty with patella replacement. Some suggest that the pathogenesis of residual knee pain may be related to mechanical stimuli that activate free nerve endings around the patellofemoral joint. Various etiologies have been implicated in residual pain, including (1) low-grade infection, (2) midflexion instability, and (3) component malalignment with patellar maltracking. Less common causes include (4) crepitation and patellar clunk syndrome; (5) patellofemoral symptoms, including overstuffing and avascular necrosis of the patella; (6) early aseptic loosening; (7) hypersensitivity to metal or cement; (8) complex regional pain syndrome; and (9) pseudoaneurysm. Because all of these conditions can lead to residual pain, identifying the etiology can be a difficult diagnostic challenge. Often, patients with persistent pain and normal findings on radiographs and laboratory workup may benefit from a diagnostic injection or further imaging. However, up to 10% to 15% of patients with residual pain may have unexplained pain. This literature review summarizes the findings on the causes of residual pain and presents a diagnostic algorithm to facilitate an accurate diagnosis for residual pain after total knee arthroplasty.

Role of magnetic resonance imaging in the diagnosis of the painful unicompartmental knee arthroplasty

BACKGROUND Unicompartmental knee arthroplasty (UKA) is a well established method for the treatment of single compartment arthritis; however, a subset of patients still present with continued pain after their procedure in the setting of a normal radiographic examination. This study investigates the effectiveness of magnetic resonance imaging (MRI) in guiding the diagnosis of the painful unicompartmental knee arthroplasty. METHODS An IRB-approved retrospective review identified 300 consecutive UKAs performed over a three years period with 28 cases of symptomatic UKA (nine percent) with normal radiographic images. RESULTS MRI examination was instrumental in finding a diagnosis that went undetected on radiographs. Based on MRI findings, 10 (36%) patients underwent surgery whilst 18 (64%) were treated conservatively. CONCLUSION This study supports the use of MRI as a valuable imaging modality for managing symptomatic unicompartmental knee arthroplasty. LEVEL OF EVIDENCE Case series.

Hip arthroscopy: the use of computer assistance.

Background:Hip arthroscopy is rapidly becoming the mainstay of treatment for femoroacetabular impingement (FAI), but remains technically demanding and has its limitations. The failures of arthroscopic FAI surgery due to inaccurate and inadequate resection are reported to be increasing. Computer-assisted surgery (CAS) can theoretically improve the accuracy and precision of the osseous resections required to treat FAI. It does so by providing a preoperative assessment tool, an intraoperative tracking device, and a robotic-assisted cutting instrument.Questions/Purposes:The purpose of this review is to discuss the evolution of CAS to address the current limitations of arthroscopic FAI surgery and propose the features required of the ideal CAS solution for FAI.Methods:A computerized keyword search of MEDLINE was performed for studies that investigated the use of computer assistance in FAI surgery. Data was collected on preoperative assessment tools, intraoperative navigation programs, and robotic-assisted execution of FAI surgery.Results:Sixty-one articles were identified after the keyword search. Nineteen studies met our inclusion criteria. Thirteen studies were selected to address our study questions: three studies were analyzed for preoperative planning, six for navigated osseous resection, and four for robotic-assisted execution.Conclusion:Navigation and robotic-assisted surgery can preoperatively plan and execute osseous resection with greater accuracy compared to freehand techniques, although the clinical success and cost-effectiveness has yet to be demonstrated. The ideal CAS solution must be able to virtually plan a resection, guide the surgeon towards accurate execution of the plan, and facilitate post-resection assessment of the adequacy of resection.

Robotic-assisted femoral osteochondroplasty is more precise than a freehand technique in a Sawbone model

Robotic-assistance has the potential to improve the accuracy of bony resections, when performing femoral osteochondroplasty in the treatment of cam-type femoroacetabular impingement (FAI). The purpose of this study was to determine the accuracy of robotic-assisted femoral osteochondroplasty and compare this to a conventional open, freehand technique. We hypothesized that robotic-assistance would increase the accuracy of femoral head-neck offset correction in cam FAI. Sixteen identical sawbones models with a cam-type impingement deformity were resected by a single surgeon, simulating an open femoral osteochondroplasty. Eight procedures were performed using an open freehand technique and eight were performed using robotic-assistance, through the creation of a three-dimensional haptic volume. A desired arc of resection of 117.7° was determined pre-operatively using an anatomic plan. Post-resection, all 16 sawbones were laser scanned to measure the arc of resection, volume of bone removed and depth of resection. For each sawbone, these measurements were compared with the pre-operatively planned desired resection, to determine the resection error. Freehand resection resulted in a mean arc of resection error of 42.0 ± 8.5° compared with robotic-assisted resection which had a mean arc of resection error of 1.2 ± 0.7° (P < 0.0001). Over-resection occurred with every freehand resection with a mean volume error of 758.3 ± 477.1 mm3 compared with a mean robotic-assisted resection volume error of 31.3 ± 220.7 mm3 (P < 0.01). This study has shown that robotic-assisted femoral osteochondroplasty in the treatment of cam-type FAI is more accurate than a conventional, freehand technique, which are currently in widespread use.

The Impact of Body Checking on Youth Ice Hockey Injuries

Background: Body checking is a common cause of youth ice hockey injuries. Consequently, USA Hockey raised the minimum age at which body checking is permitted from the Pee Wee level (11-12 years old) to the Bantam level (13-14 years old) in 2011. Purpose/Hypothesis: The purpose of this investigation was to determine the impact of body checking on the distribution of injuries reported in youth ice hockey players. We hypothesized that the elimination of body checking at the Pee Wee level would lower the frequency of serious injuries, particularly concussions. Study Design: Descriptive epidemiology study. Methods: Injury data from the National Electronic Injury Surveillance System (NEISS), a United States Consumer Product Safety Commission database, were analyzed for Pee Wee and Bantam players between January 1, 2008 and December 31, 2010 and again between January 1, 2013 and December 31, 2015. Data on the location of injury, diagnosis, and mechanism of injury were collected. The location of injury was categorized into 4 groups: head and neck, upper extremity, lower extremity, and core. Diagnoses investigated included concussions, fractures, lacerations, strains or sprains, internal organ injuries, and other. The mechanism of injury was broken down into 2 categories: checking and other. Results: Between the 2008-2010 and 2013-2015 seasons, overall injuries decreased by 16.6% among Pee Wee players, with injuries caused by body checking decreasing by 38.2% (P = .012). There was a significant change in the distribution of diagnoses in the Pee Wee age group during this time frame (P = .007): strains or sprains, internal organ injuries, and fractures decreased in frequency, while the number of concussions increased by 50.0%. In the Bantam age group, recorded injuries decreased by 6.8%, and there was no change in the distribution of the location of injury, diagnosis, or mechanism of injury (P > .05). Conclusion: There was an observed reduction in the total number, mechanism, and type of injuries when body checking was eliminated from the Pee Wee level. There was, however, an unexpected increase in the number of concussions.

Performance-Based Outcomes after Operative Management of Athletic Pubalgia / Core Muscle Injury in National Football League Players

Objectives: Athletic pubalgia is a condition in which there is an injury to the core musculature that precipitates groin and lower abdominal pain, particularly in cutting and pivoting sports. These are common injury patterns in the National Football League (NFL); however, the effect of surgery on performance for these players has not been described. Methods: Athletes in the NFL that underwent a surgical procedure for athletic pubalgia / core muscle injury (CMI) were identified through team injury reports and archives on public record since 2004. Outcome data was collected for athletes who met inclusion criteria which included total games played after season of injury / surgery, number of Pro Bowls voted to, yearly total years and touchdowns for offensive players and yearly total tackles sacks and interceptions for defensive players. Previously validated performance scores were calculated using this data for each player one season before and after their procedure for a CMI. Athletes were then matched to control professional football players without a diagnosis of athletic pubalgia by age, position, year and round drafted. Statistical analysis was used to compare pre-injury and post-injury performance measures for players treated with operative management to their case controls. Results: The study group was composed of 32 NFL athletes who underwent operative management for athletic pubalgia that met inclusion criteria during this study period, including 18 offensive players and 16 defensive players. The average age of athletes undergoing this surgery was 27 years old. Analysis of pre- and post-injury athletic performance revealed no statistically significant changes after return to sport after surgical intervention; however, there was a statistically significant difference in the number of Pro Bowls that affected athletes participated in before surgery (8) compared to the season after surgery (3). Analysis of durability, as measured by total number of games played before and after surgery, revealed no statistically significant difference. Conclusion: National Football League players who undergo operative care for athletic pubalgia have a high return to play with no decrease in performance scores when compared to case-matched controls. However, the indications for operative intervention and the type of procedure performed are heterogeneous. Further research is warranted to better understand how these injuries occur, what can be done to prevent their occurrence, and the long term career ramifications of this disorder.

Advances in 2D and 3D Imaging for FAI Surgical Planning

Accurate preoperative assessment of osseous morphology and precise surgical resection is critical in the diagnosis and surgical management of femoroacetabular impingement (FAI). Hip arthroscopy has quickly become the mainstay of treatment for FAI; however, it remains technically demanding and has its limitations. This chapter discusses the use of imaging studies for the assessment and treatment of FAI.

Foot Progression Angle Walking Test- An Effective Dynamic Test for the Diagnosis of Femoroacetabular Impingement and Hip Instability

Objectives: Clinical diagnosis of femoroacetabular impingement (FAI) and hip instability is determined by accurate history, physical examination, and imaging assessment. Currently, there is no ideal physical examination maneuver and certainly no dynamic method of testing. In this prospective study, we evaluate the Foot Progression Angle Walking (FPAW) test as a novel diagnostic tool that is sensitive and specific for the detection of FAI and hip instability. Methods: A prospective cohort of patients who presented with hip pain underwent FPAW testing in addition to the gold standard assessments for impingement and instability, the Flexion Adduction and Internal Rotation (FADIR) test and the Abduction and External Rotation (ABER) test, respectively. Baseline foot progression angles were initially recorded. Patients were then instructed to walk with foot progression angles: 1) internally rotated (-15º) and 2) externally rotated (+15º). A positive FPAW test was defined by an increase in hip pain with either internal or external rotation. Radiographs and/or magnetic resonance imaging were then used to evaluate for abnormal hip morphology and confirm diagnosis. Results: 80 patients (53 Female) with hip pain were evaluated by FPAW testing. Imaging used to assess for hip pathology exhibited FAI (n=48), instability (n=26) and normal anatomic morphology (n=13). Baseline measurements showed a neutral foot progression (64%), out-toeing gait (35%), and in-toeing gait (1%). Analysis of FPAW testing showed a sensitivity of 75% and specificity of 66% for FAI; sensitivity 54% and specificity 61% for instability. A positive predictive value (FAI: 77%; Instability 40%) and negative predictive value (FAI 64%; Instability 73%) were also determined. In comparison, the FADIR test showed a sensitivity and specificity of 96% and 13% for FAI, respectively. Its positive predictive value was 62% while its negative predictive value was 67%. Abduction and external rotation testing showed a sensitivity and specificity of 42% and 96%, respectively for diagnosing instability. Its positive predictive value was 85% and negative predictive value was 78%. Conclusion: FPAW testing was found to be more sensitive and specific for detecting FAI than instability. The higher specificity and positive predictive value of FPAW in comparison to the FADIR test makes it a reliable tool to identify patients with impingement. The FPAW test appears to be an effective tool to reproduce hip pathology in FAI patients during weight-bearing activity and could be a useful adjunct to give further clinical prospective in FAI and hip instability.