Hip Arthroscopy in Patients with Spine Pain: Outcomes Vary Compared to Patients with Isolated Hip Pathology, but Many Hip-Spine Patients Do Just as Well.

Low back pain present concurrently with hip impingement or labral pathology is frustrating for both patient and surgeon. It is difficult to distinguish true hip pathology from secondary low back symptoms, even with the use of diagnostic injections, cross-sectional imaging, electromyography, and/or nerve conduction studies. In addition, even properly indicated hip arthroscopy can exacerbate sciatic nerve dysfunction, a known complication from traction, and altered gait in the early postoperative period can aggravate sacroiliac and lumbar pathology. Moreover, difficult results vary in these patients after hip arthroscopy, and show higher revision rates and less improvement in functional scores compared to patients with isolated hip pathology. Nevertheless, appropriately selected "hip-spine" patients show significant benefit from hip arthroscopy. Provided they have appropriate counseling, many hip-spine patients can undergo hip arthroscopy and experience a satisfying, durable outcome, and improvements at one year post-operatively are shown to be maintained at five or more years.

The Air-Lift Technique for Improving Ease and Safety When Establishing the Modified Midanterior Portal in Hip Arthroscopy.

Hip arthroscopy continues to increase in popularity and has an ever-expanding range of indications; however, the steep learning curve introduces significant risk of iatrogenic chondrolabral injury when accessing the joint and establishing arthroscopic portals. This article presents a technique for establishing the modified midanterior portal and is particularly useful when the available space is tight. We present "the air-lift" as a safe and simple adjunct to standard portal creation when performing hip arthroscopy in the supine position.

Editorial Commentary: Diagnosis of Hip Acetabular Retroversion Requires 3-Dimensional Imaging.

Diagnosis of global hip acetabular retroversion requires 3-dimensional imaging. Using anteroposterior pelvis radiographs, the crossover sign has been associated with retroversion. Recent research reports that the ischial spine sign and posterior wall sign also should be considered, yet even taking into account all 3 signs, the false-positive rate for retroversion is reported as greater than 35%. In truth, an anteroposterior radiograph is not sufficient for determination of acetabular retroversion. Retroversion is a 3-dimensional condition, and magnetic resonance imaging or computed tomography-based measurements are required. Thus, before we can determine the efficacy of hip arthroscopy versus periacetabular osteotomy for patients with hip impingement secondary to acetabular retroversion, we need to precisely measure to confirm our diagnosis.

Editorial Commentary: Improved Operating Room Efficiency Is the Best Way to Control Orthopaedic Costs.

Current procedural terminology codes and assigned relative value units associated with arthroscopic hip surgery lag behind other joints in accurately describing, and often undervaluing, what surgery entails. Hip arthroscopy is expensive, and, to address inequity, procedural cost drivers require review. Consumable implants and operating room (OR) time drive the costs associated with the procedure. Hospitals, healthcare payors, patients, and surgeons all benefit from increasing OR efficiency and reducing equipment cost. However, the patient loses if financial strategy supersedes care delivery, and it is wrong to cut necessary use of consumables to save money. Fewer anchors is not the answer (yet we should use reusable, nonimplantable supplies when feasible). The greater opportunity to lower costs is improved OR efficiency, requiring a team approach with buy-in from perioperative, anesthesia, surgical staff, and administrators. OR time is a consistent driver of cost across every type of orthopaedic surgery. Studies evaluating strategies for OR efficiency in hip arthroscopy will benefit the field. By leading this effort, surgeons could be best positioned to address inadequate relative value units.

The Effects of Residual Femoral Deformity on Computed Contact Mechanics in Patients Treated With In Situ Fixation for Slipped Capital Femoral Epiphysis.

OBJECTIVE: In situ fixation for treatment of slipped capital femoral epiphysis (SCFE) can stabilize the epiphysis and prevent further joint deformation but often leaves residual deformity that may adversely affect intra-articular contact mechanics. The purpose of this study was to investigate the relationship between residual deformity and contact mechanics in the post-SCFE hip. METHODS: Patient-specific hip models were created for 19 patients with SCFE treated with in situ fixation. For each model, discrete element analysis was used to compute cumulative acetabular and femoral contact stress exposure during a walking gait cycle. Slip severity was evaluated for each patient using the two-dimensional Southwick angle and a novel three-dimensional (3D) assessment of multiplanar femoral deformity (3D slip angle). RESULTS: Of the SCFE cases, 2/7 mild (Southwick angle ≤30 degrees) had peak cumulative femoral exposures equivalent to that of severe (Southwick angle ≥60 degrees) cases. Severe SCFE cases had higher peak ( P = 0.015) and mean ( P = 0.028) femoral contact stress exposure and lower cumulative femoral contact area ( P = 0.003) than mild (Southwick angle ≤30 degrees) SCFE cases. Mean femoral contact stress exposure was also higher in severe SCFE cases than in moderate SCFE cases ( P = 0.027). Acetabular and femoral contact mechanics metrics typically demonstrated stronger correlations with 3D slip angle than two-dimensional Southwick angle. CONCLUSIONS: Increased slip severity adversely impacts intra-articular femoral contact mechanics. Contact mechanics metrics demonstrate higher correlations with 3D slip angle, indicating that this novel measurement may better describe global deformity and its relationship to intra-articular mechanics; however, the modest strength of these correlations may also imply that global impingement-generating deformity is not the primary factor driving contact mechanics in the post-SCFE hip. CLINICAL RELEVANCE: Greater slip severity adversely impacts contact mechanics in the post-SCFE hip. However, focal regions of high contact stress were seen even in mild SCFE deformities, suggesting some type of deformity correction should be considered even for mild slips to alleviate secondary impingement, address focal incongruities, and reduce osteoarthritis development/progression.

Editorial Commentary: Hip Arthroscopy Pain Management With Surgeon-Administered Pericapusular Injection Is Fast, Safe, Inexpensive, and Effective.

Regional pain management after hip arthroscopy is challenging. The hip capsule alone has a complex and highly variable innervation, including contributions from articular branches of the femoral, obturator, accessory obturator, accessory femoral, superior gluteal, accessory superior gluteal, inferior gluteal, sciatic, and posterior femoral cutaneous nerves, nerve to the quadratus femoris, as well as a direct supply from the lumbosacral plexus. Thus, it is unrealistic to expect a traditional peripheral nerve block, including blocks of the proximal lumbar plexus, femoral nerve, and fascia iliaca region to provide thorough hip analgesia without inducing quadriceps weakness that could result in a patient experiencing a fall during the postoperative period. In addition, newer, sensory-only blocks, such as quadratus lumborum or pericapsular nerve group blocks, have not been shown to be superior to simple pericapsular injection (PCI). Hip arthroscopy pain management using surgeon administered PCI is fast, safe, inexpensive, and effective. While not perfect, PCI is the best option among current choices.

Pain Catastrophizing, Kinesiophobia, Stress, Depression, and Poor Resiliency Are Associated With Pain and Dysfunction in the Hip Preservation Population.

Background: Psychiatric disorders are known to have a negative impact on outcomes attained from hip-preservation surgery. Psychosocial traits such as resiliency and pain avoidance likely also affect treatment outcomes, however these characteristics are less easily identified, and data is lacking supporting their presence and impact on related outcomes within the hip preservation population. We therefore evaluated hip preservation patients for a variety of maladaptive psychosocial traits and assessed patient-reported outcomes (PROs) in order to ascertain which specific traits were most associated with hip pain and dysfunction. Methods: 62 subjects aged 15-49 years presenting for evaluation of a nonarthritic hip condition completed psychosocial questionnaires and patient reported outcome measures via electronic survey as listed in table one. Participants were tested again eight weeks later to evaluate the relationship between changes in physical function, pain, and mental health behaviors. Pearson correlation coefficients assessed association between hip PROs and psychosocial tests and analyses were corrected for multiple comparisons. Results: Pain Catastrophizing (PCS), Kinesiophobia (TSK), Stress, and PROMIS-Global Mental Health (GMH) scores correlated with poor physical function and high pain scores at zero and eight weeks. Low resiliency (BRS) and depression were also associated with elevated pain on PRO tests as well as HOOS-Physical Function. There was a moderately strong correlation between improvement in PROMIS-Physical Function (PF) from zero to eight weeks and subjects initial scores for kinesiophobia, anxiety, and stress (r= -0.45, -0.41, -0.44, all p<0.05). Conclusion: PCS, TSK, Stress, Depression, and low BRS are associated with pain and disability in hip preservation subjects. Elevated TSK, Anxiety and Stress may be predictors of failure to improve with nonoperative treatment. These psychosocial characteristics should be investigated further as predictors of clinical outcomes in the hip preservation population. Level of Evidence: II.

Editorial Commentary: Segmental Hip Labral Reconstruction May Be Superior to Circumferential Reconstruction: Bigger Isn't Better.

Hip arthroscopic segmental and circumferential labral reconstruction show similar outcomes in short-term follow-up. Will bigger (circumferential reconstruction) eventually be largely a historical method? Bigger does not appear to be better, although some argue that segmental techniques inadequately restore the labrum's function, incompletely treat the defect, and result in mismatch at the labral-graft junction, which is also a "weak spot" for future tears. Yet, others show that circumferential reconstruction is without clear benefit and adds additional anchors, complexity and operating room time and costs. The next phase of research on hip labral reconstruction requires evaluation of the numerous variables within the category of "reconstruction." Today, a great number of different reconstruction techniques exist. Measuring a segmental defect can be challenging but is facilitated with methods such as the kite technique, use of a shoulder superior capsular reconstruction guide, or a pull-through method to simply avoid measuring. Graft options include ligamentum teres and iliotibial band, anterior and posterior tibialis, hamstring, fascia lata, autograft and allograft. Graft preparation, passage, and fixation techniques also vary widely. Finally, determining how much overlap with native labrum, ideal graft tension, or integrating the transverse acetabular ligament is more art than science. It's time we begin to critically evaluate the differences in reconstructive techniques.

Editorial Commentary: Despite Decades of Research on Patellar Instability, the Isolated Lateral Release Endures.

Surgical management of patellar instability has transformed over the last 40 years as our understanding of contributing anatomical factors, particularly medial patellofemoral ligament insufficiency, has matured. The International Patellofemoral Study Group recently concluded with 89% agreement that lateral release should not be done in isolation for patellofemoral instability. And yet, with 11% dissent, controversy remains, and the isolated lateral retinacular release for patellar instability continues to be favored by a subset of surgeons. In my opinion, lateral retinacular release may have a role in the rare situation in which laterally based capsuloligamentous tightness has led to focal patellar compression, but in the setting of patellar instability, lateral release should not be used alone as a solution for patellofemoral instability.

Automated Text-Messaging After Hip Arthroscopy: A Randomized-Controlled Trial of "Post-Op Buddy".

PURPOSE: To assess an automated text-messaging system for patients after hip arthroscopy and its impact at 90 days on the Hip Disability Osteoarthritis Outcome Score Physical Function Short form (HOOS-PS, HOOS-Pain), compliance with rehabilitation guidelines, and patient satisfaction. METHODS: One hundred twenty-one participants (average age 29 ± 8.7 years, 52% female) undergoing hip arthroscopy at 2 academic institutions were prospectively enrolled and randomized to receive (1) standard perioperative communication or (2) additional automated mobile phone text messages. Inclusion criteria included ability to communicate in written English and access to a mobile phone with text-messaging capability. Patients undergoing revision surgery or simultaneous femoral or acetabular osteotomy were excluded. HOOS-PS and HOOS-Pain were collected preoperatively, and after surgery an automated mobile phone robot sent participants in the therapeutic arm intermittent text messages for 90 days. At 90 days all participants again completed HOOS-PS, HOOS-Pain, and additional survey questions on satisfaction with their experience (10-point scale), communication from the surgical team (10-point scale) and adherence to physical therapy exercises, weight-bearing guidelines, and brace use, The primary outcome assessed was a statistically significant change in HOOS-PS and HOOS-Pain; secondary outcomes included change in satisfaction, communication, and adherence to physical therapy exercises, weightbearing guidelines, or brace use. Wilcoxon rank sum was used to compare HOOS-PS and HOOS-Pain scores at 0 and 90 days. Demographic characteristics and survey variables were compared using Students t test for continuous variables and χ2 or Fisher exact test for categorical variables as appropriate. RESULTS: There were statistically significant and clinically relevant improvements in HOOS-PS and HOOS-Pain in both groups (P < .05). Subjective feedback was strongly positive, with 96% of text message participants reporting they would choose automated messages if it was offered to them again in the future. CONCLUSIONS: Ninety days of automated text messaging after hip arthroscopy failed to show a significant difference in HOOS-PS (P = .09), HOOS-Pain (P = .13), patient-reported compliance with postoperative guidelines, or satisfaction with support and communication from the surgical team. LEVEL OF EVIDENCE: I, randomized control trial (RCT).

Activity Level and Sport Type in Adolescents Correlate with the Development of Cam Morphology.

BACKGROUND: The purpose of this study was to evaluate the influence of the volume and type of sport on the development of cam-type femoroacetabular impingement and acetabular dysplasia. METHODS: The Physical Activity Questionnaire for Adolescents (PAQ-A) was administered to Iowa Bone Development Study participants at the age of 17 years to identify those who had participated in at least 2 seasons of high school interscholastic sports. Based on relative peak strain and ground reaction forces, subjects were grouped as power sport athletes (basketball, cheerleading, football, gymnastics, soccer, and volleyball), non-power sport athletes (wrestling, baseball, cross-country or track and field, softball, or tennis), or non-athletes. Using anteroposterior views of the left hip formatted from dual x-ray absorptiometry (DXA) scans, the alpha angle, head-neck offset ratio (HNOR), and lateral center-edge angle (LCEA) were evaluated longitudinally at the ages of 17, 19, and 23 years. Logistic regression was used to evaluate the odds of hip cam morphology (alpha angle >55° and/or HNOR <0.17) or acetabular dysplasia (LCEA <24°) at the age of 23 years in all athlete groups. The relationships between physical activity level and hip measures (alpha angle, HNOR, and LCEA) from the ages of 17 to 23 years were examined using linear mixed models adjusted for sex. RESULTS: Compared with non-athletes at the age of 23 years, power sport athletes had significantly greater odds of cam morphology according to the alpha angle (odds ratio [OR], 2.93 [95% confidence interval (CI), 1.02 to 8.41]; p = 0.046) and HNOR (OR, 1.91 [95% CI, 1.01 to 3.60]; p = 0.047), but not greater odds of acetabular dysplasia (p > 0.05). There were no significant differences in the odds of cam morphology or acetabular dysplasia in non-power sport athletes compared with non-athletes (all p > 0.05). Higher physical activity levels were significantly associated with an increase in the alpha angle (beta and standard error, 0.77° ± 0.30°; p = 0.011) and a decrease in the HNOR (-0.003 ± 0.001; p = 0.003), but not the LCEA (-0.05 ± 0.15; p = 0.744). CONCLUSIONS: A higher volume of physical activity and participation in sports with higher peak strain and ground reaction forces during the process of skeletal maturation may increase the risk of developing cam morphology during late adolescence. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Physical Performance Tests Correlate With Patient-reported Outcomes After Periacetabular Osteotomy: A Prospective Study.

INTRODUCTION: Individuals with hip dysplasia report significant functional disability that improves with periacetabular osteotomy (PAO). Four physical performance measures (PPMs) have been recently validated for use with nonarthritic hip conditions; however, their ability to detect functional improvement and correlate with improvements in popular hip-specific patient-reported outcome (PRO) instruments after PAO is unknown. The purpose of this study was to evaluate the responsiveness of four PPMs up to 1 year after PAO, compare PPMs with established PRO measures at these time points, and report the acceptability and utility of PPMs for assessing outcomes after PAO. METHODS: Twenty-two participants aged 15 to 39 years completed the timed stair ascent (TSA), sit-to-stand five times (STS5), self-selected walking speed, four-square-step test, and seven hip-specific PRO measures before surgery and at approximately 6 months and 1 year after PAO. They completed questions regarding acceptability and utility of both types of testing. Wilcoxon rank sum test and unpaired Student t-tests were used to assess differences between time points; Spearman correlation and generalized linear modeling were used to determine the relationship between PPMs and PRO measures. RESULTS: Six months after PAO, participants showed significant improvements on all seven PRO instruments (P < 0.001) and on the STS5 (P = 0.01). At one year, these improvements were maintained and TSA also improved (P = 0.03). Improvement in other PPMs did not reach significance (P = 0.07 and 0.08). The STS5 test demonstrated moderate to strong correlation (|r| = 0.43 to 0.76, P < 0.05) with all PRO measures, and the TSA test demonstrated moderate to strong correlation with almost all measures (|r| = 0.43 to 0.58, P < 0.05). Correlations strengthened on subanalysis of participants with unilateral disease (n = 11) (|r| = 0.56 to 0.94, P < 0.05). All participants (100%) found PPM testing acceptable despite disability; 25% preferred PPMs to PRO measures, whereas 75% of participants found them equal in usefulness. DISCUSSION: The STS5 and TSA tests demonstrated moderate to very strong correlation with PRO measures at six and 12 months after PAO for dysplasia. These tests could be used as a functional outcome to supplement PRO instruments after PAO.

Assessment of Disability Related to Hip Dysplasia Using Objective Measures of Physical Performance.

BACKGROUND: Lower extremity physical performance measures (PPMs), which can objectively quantify functional ability, are an attractive adjuvant to patient-reported outcome (PRO) instruments. However, few tests have been validated for use in hip instability. PURPOSE: To evaluate 4 different PPMs for their ability to differentiate between young adults with hip dysplasia indicated for treatment with periacetabular osteotomy (PAO) and asymptomatic controls and to test inter- and intratest reliability and relationship with popular hip PRO instruments. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A total of 24 symptomatic patients aged 15 to 39 years (100% female) with hip dysplasia (lateral center-edge angle <25°) indicated for treatment with PAO completed the visual analog scale (VAS) for pain, Hip disability and Osteoarthritis Outcome (HOOS) Pain subscale, HOOS Short Version (HOOS PS), International Hip Outcome Tool Short Version (iHOT-12), modified Harris Hip Score (mHHS), Patient Reported Outcome Measurement Information System (PROMIS) physical function (PF) and pain interference (PI), and 4 physical function tests: (1) self-selected walking speed (SSWS), sit-to-stand 5 times (STS5), (3) 4-square step test (FSST), and (4) timed stair ascent (TSA). A further 21 young, asymptomatic adults aged 18 to 39 years (91% female) also underwent testing. Between-group comparisons were made with unpaired t test with Bonferroni-Holm correction. Inter- and intrarater reliability was assessed in 38 participants by repeating PPMs at a second visit and using 2 raters. Spearman rank correlation coefficients were used to determine associations between PPMs and PRO instruments. RESULTS: Significant differences between patients with hip dysplasia and controls were observed for all PRO instruments (HOOS Pain, 47.8 vs 99.2; HOOS PS, 61.9 vs 99.2; iHOT-12, 32.2 vs 99.2; mHHS, 54.5 vs 90.6; PROMIS PF, 41.4 vs 65.6; and PROMIS PI, 62.0 vs 39.1 [all P < .001]), and all PPMs (SSWS, 1.21 vs 1.53 m/s; STS5, 10.85 vs 5.95 s; FSST, 6.59 vs 4.03 s [all P < .001]; and TSA, 4.58 vs 3.29 s [P = .002]). All 4 PPMs demonstrated excellent intra- and intertest reliability (intraclass correlation coefficient, 0.83-0.99). STS5, FSST, and TSA were correlated highly (r > 0.5) with physical function PRO instruments, including PROMIS PF, mHHS, and iHOT-12. CONCLUSION: Patients with symptomatic hip dysplasia demonstrated significant impairment on functional testing compared with asymptomatic controls, and performance measure testing demonstrated excellent test-retest reliability. Timed stair ascent and sit-to-stand testing in particular were correlated strongly with physical function PRO instruments. PPMs may be a viable and well-received adjuvant to PRO instrument administration for patients with nonarthritic hip conditions, and investigation of the ability of PPMs to assess surgical outcomes for hip dysplasia is warranted.

Closed Vs. Open Reduction/Salter Innominate Osteotomy for Developmental Hip Dislocation After Age 18 Months: Comparative Survival at 45-Year Follow-up.

BACKGROUND: Despite widespread use of single-stage open reduction and pelvic osteotomy for treatment of developmental dysplasia of the hip (DDH) after walking age, this aggressive strategy remains controversial. We directly compared dislocated hips treated with closed reduction (CR) to those treated with open reduction and Salter innominate osteotomy (OR/IO) to estimate the relative hazard of total hip arthroplasty (THA) and the THA-free survival time. METHODS: In a series of patients 18 to 60 months of age, 45 patients (58 hips) underwent CR and 58 patients (78 hips) were treated with OR/IO and followed to a minimum 40 years post-reduction. Observations in the survival analysis were censored if no THA had occurred by 48 years. Multivariate Cox regression analysis was used to estimate the hazard of THA given treatment, age, and bilaterality. Complications and additional procedures were noted. RESULTS: At 48 years of follow-up, 29 (50%) of the hips survived after CR compared with 54 (69%) after OR/IO. At 45 years, the survival probability after OR/IO was 0.63 (95% confidence interval [CI] = 0.50 to 0.78) compared with 0.55 (95% CI = 0.43 to 0.72) after CR. The hazard ratio (HR) of THA was modeled as a function of treatment, age at reduction, and bilaterality. The effect of age and treatment on the outcome of hips in patients with unilateral involvement was minimal. However, age did significantly alter the relationship between treatment and outcome in bilateral cases. In the bilateral group, the predicted HR of THA was lower after CR in hips that were reduced at the age of 18 months (HR = 0.16, 95% CI = 0.04 to 0.64) but higher in those that were reduced at 36 months (HR = 4.23, 95% CI = 2.00 to 8.95). Additional procedures were indicated for 17% and 22% of hips after CR and OR/IO, respectively. CONCLUSIONS: Osteoarthritis and THA was more likely after CR than OR/IO, but the data do not indicate a difference in unadjusted hip-survival time. In patients with bilateral disease, an older age at reduction was associated with an increased hazard of THA after CR than after OR/IO. Both treatments provided substantial benefit relative to the natural history of DDH, but THA is the expected outcome in middle adulthood. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Weight-Bearing CT Scan After Tibial Pilon Fracture Demonstrates Significant Early Joint-Space Narrowing.

BACKGROUND: Posttraumatic osteoarthritis (PTOA) is a common and early sequela of tibial pilon fractures resulting in substantial long-term disability. New approaches are needed to objectively and reliably quantify early disease progression in order to critically assess the impact of interventions aimed at preventing or mitigating PTOA. Weight-bearing computed tomography (WBCT) scans provide a means for measuring joint space while the ankle is in a loaded, functional position. We assessed the interrater and intrarater reliability of a standardized, regional method to quantify joint-space loss following tibial pilon fracture compared with the uninjured contralateral ankle. METHODS: We prospectively enrolled 20 patients with intra-articular tibial pilon fractures that were surgically treated at 1 of 2 level-I trauma centers. Six months after injury, bilateral ankle WBCT scans were obtained. Joint space was measured by 4 reviewers at 9 discrete regions of the tibiotalar articulation on sagittal images. Measurements were repeated by reviewers 2 weeks later. To characterize the measurement method, interrater correlation coefficient estimates and test-retest reproducibility were calculated. RESULTS: The mean tibiotalar joint space was 21% less in the injured ankles compared with the contralateral uninjured ankles (p < 0.0001). The middle-lateral and middle-central regions of the joint demonstrated the greatest decrease in joint space between injured and uninured ankles. The interrater correlation coefficient of the measurement technique was 0.88, and the test-retest reproducibility was 0.80, indicating good reliability and reproducibility of the method. CONCLUSIONS: We developed a simple, standardized, and reliable technique to quantify tibiotalar joint space following tibial pilon fracture on WBCT. Significant loss of joint space is seen 6 months after the injury. This tool can be used to longitudinally quantify loss of joint space following pilon fracture and assess the impact of interventions to reduce PTOA.

Mobile Phone Administration of Hip-Specific Patient-Reported Outcome Instruments Correlates Highly With In-office Administration.

INTRODUCTION: Patient-reported outcome (PRO) instruments typically are delivered via paper or computer; we validated administration of hip-specific instruments over a mobile phone software communication platform outside a clinical encounter. METHODS: Consecutive patients (n = 69) presenting to a hip preservation clinic completed the Hip Disability and Osteoarthritis Outcome Score Short Form physical function and pain subscales (HOOS-PS and HOOS-PAIN) using standard collection techniques. The subsequent day, patients completed these instruments via a text messaging software program. Text reminders were sent to encourage completion of unanswered questions. Correlation between in-office and mobile phone delivery of PROs was assessed. RESULTS: The intraclass correlation coefficient between in-clinic and mobile phone delivery of HOOS-PS and HOOS-PAIN was 0.72 (95% confidence interval, 0.58 to 0.81) and 0.80 (95% confidence interval, 0.69 to 0.87), respectively. Completion rate of 93% (64 of the 69) was observed using mobile phone and software messaging. Nine patients completed their PRO after being sent a text message reminder. Fifty-one percent of patients completed all PRO questions within 5 minutes; 26% took between 5 and 10 minutes, and 16% took 10 to 30 minutes for completion. DISCUSSION: HOOS-PS and HOOS-PAIN PRO instruments administered via text messaging with automated reminders demonstrate good to excellent reproducibility, no minimal detectable change between communication methods, and a high completion rate in adolescents and young adults with hip pain. Mobile phone delivery via automated software may be a valid method for administration of other PROs, allowing for communication with patients anytime and anywhere. LEVEL OF EVIDENCE: Level IV, case series.

Outcomes of Hip Arthroscopy in the Medicare Patient: A Growing Population.

Background: Although the results of hip arthroscopy in the elderly have been inferior to the results in younger patients, there have recently been some encouraging reports in carefully selected series of older patients. The purpose of this study was to identify the utilization of hip arthroscopy in the Medicare population and to determine the rate and timing of revision arthroscopy and/or total hip arthroplasty (THA) with the goal of identifying risk factors for secondary procedures based on patient demographics, comorbidities and the diagnosis at the time of arthroscopy. Methods: The Medicare Standard Analytic Files were reviewed from 2005-2014 for all patients undergoing hip arthroscopy allowing for minimum 2 year follow-up (100% sample). Patients were tracked through the dataset for the occurrence of an ipsilateral THA or revision hip arthroscopy. Rates and timing of the subsequent procedures were then determined within 6 month intervals. Patients less than 65 years old were excluded. Multivariate logistic regression analysis was performed to determine the impact of patient age, sex, obesity or a diagnosis of hip osteoarthritis on need for revision procedures. Results: 3,320 Medicare patients had a hip arthroscopy during 2005-2014 (0.3% compared to THA). 73 patients (2.2%) underwent reoperation during the follow-up period. Two-thirds (n = 46) of all revision procedures occurred within one year of primary hip arthroscopy. A pre-operative diagnosis of hip osteoarthritis significantly increased the odds of reoperation (OR = 5.3). (Conclusion: Relatively few numbers of Medicare patients underwent hip arthroscopy during the time interval evaluated (0.3% when compared to THA utilization). 2.2% underwent a subsequent revision arthroscopy or THA with many occurring soon after the procedure and for the diagnosis of hip OA demonstrating the need to better define indications in this population. This study should provide baseline utilization and outcome trends for future studies.Level of Evidence: IV.

Unaddressed Cam Deformity Is Associated with Elevated Joint Contact Stress After Periacetabular Osteotomy.

BACKGROUND: Femoral cam deformity is frequently present in patients with acetabular dysplasia. Computational modeling can be used to identify how this deformity affects joint mechanics. Our purpose was to identify the relationship between cam deformity and joint contact stress after periacetabular osteotomy (PAO). We hypothesized that cam deformity is associated with an increase in peak joint contact stress after PAO. METHODS: This was a retrospective review of patients treated for hip dysplasia with PAO without femoral osteochondroplasty. Patient-specific hip models created from preoperative and postoperative computed tomography (CT) scans were evaluated using discrete element analysis to determine maximum joint contact stress after PAO. Twenty hips with a postoperative increase in maximum contact stress were compared with 20 that demonstrated decreased maximum contact stress. Hips were assessed for cam deformity on cross-sectional imaging. Radiographic measures of acetabular dysplasia before and after PAO were assessed and compared with the change in maximum contact stress after PAO. RESULTS: There was a moderate relationship between the change in maximum contact stress and the α angle (r = 0.31; p = 0.04), and the average α angle in the hips with increased maximum contact stress was significantly different from that in the hips with decreased joint contact stress (51° ± 11.4° versus 42° ± 5.1°; p = 0.04). All 6 hips with an α angle of >60° demonstrated increased joint contact stress. CONCLUSIONS: Cam deformity is common in patients with hip dysplasia. In our study, α angles of >60° were associated with increased postoperative joint contact stress. The α angle should be assessed preoperatively, and deformity should be addressed for optimal joint mechanics after PAO. CLINICAL RELEVANCE: A reduction in joint contact stress is a proposed mechanism for the increased joint longevity following periacetabular osteotomy for hip dysplasia. Impingement from abnormal femoral offset negatively impacts clinical outcome, but this finding has not been evaluated from a biomechanical perspective previously and a threshold for performing femoral osteochondroplasty has not been established previously. This study provides biomechanical evidence supporting surgical management of femoral cam deformity for an α angle of >60°.

Performance of the PROMIS in Patients After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) is designed to advance patient-reported outcome (PRO) instruments by utilizing question banks for major health domains. PURPOSE: To compare the responsiveness and construct validity of the PROMIS physical function computer adaptive test (PF CAT) with current PRO instruments for patients before and up to 2 years after anterior cruciate ligament (ACL) reconstruction. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Initially, 157 patients completed the PROMIS PF CAT, Short Form-36 Health Survey (SF-36 physical function [PF] and general health [GH]), Marx Activity Rating Scale (MARS), Knee injury and Osteoarthritis Outcome Score (KOOS activities of daily living [ADL], sport, and quality of life [QOL]), and EuroQol-5 dimensions questionnaire (EQ-5D) at 6 weeks, 6 months, and 2 years after ACL reconstruction. Correlations between instruments, ceiling and floor effects, effect sizes (Cohen d), and standardized response means to describe responsiveness were evaluated. Subgroup analyses compared participants with and without additional arthroscopic procedures using linear mixed models. RESULTS: At baseline, 6 weeks, and 6 months, the PROMIS PF CAT showed excellent or excellent-good correlations with the SF-36 PF (r = 0.75-0.80, P < .01), KOOS-ADL (r = 0.63-0.70, P < .01), and KOOS-sport (r = 0.32-0.69, P < .01); excellent-good correlation with the EQ-5D (r = 0.60-0.71, P < .01); and good correlation with the KOOS-QOL (r = 0.52-0.58, P < .01). As expected, there were poor correlations with the MARS (r = 0.00-0.24, P < .01) and SF-36 GH (r = 0.16-0.34, P < .01 ). At 2 years, the PROMIS PF CAT showed good to excellent correlations with all PRO instruments (r = 0.42-0.72, P < .01), including the MARS (r = 0.42, P < .01), indicating frequent return to preinjury function. The PROMIS PF CAT had the fewest ceiling or floor effects of all instruments tested, and patients answered, on average, 4 questions. There was no significant difference in baseline physical function scores between subgroups; at follow-up, all groups showed improvements in scores that were not statistically different. CONCLUSION: The PROMIS PF CAT is a valid tool to assess outcomes after ACL reconstruction up to 2 years after surgery, demonstrating the highest responsiveness to change with the fewest ceiling and floor effects and a low time burden among all instruments tested. The PROMIS PF CAT is a beneficial alternative for assessing physical function in adults before and after ACL reconstruction.