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Engasser, William M.

https://orcid.org/0000-0002-7230-3356

Mayo Clinic

Mayo Clinic

Citations 9

Intra‐articular Diagnostic Injection Exhibits Poor Predictive Value for Outcome After Hip Arthroscopy
Krych, Aaron J. , Sousa, Paul L., King, Alexander H. , Engasser, William M. , Levy, Bruce A. , Krych, Aaron J

Arthroscopy | April 30, 2016 | Volume: 32 | Issue: 8 | Pages: 1592-1600

10.1016/j.arthro.2016.02.005 Get It

Purpose To determine whether the amount of pain relief after preoperative intra‐articular (IA) anesthetic injection predicts clinical and functional outcomes after hip arthroscopy, especially when controlling for the presence of chondral degeneration. Methods We identified patients who underwent IA injection and subsequent hip arthroscopy for labral pathology between 2007 and 2013 performed by a single surgeon. Inclusion criteria were ultrasound‐ or fluoroscopic‐guided IA anesthetic injection performed at our institution, prospectively documented pre‐ and postinjection numerical rating scale pain scores, and minimum 1‐year follow‐up postoperatively. Patients were divided into 2 groups, those who received >50% pain relief from preoperative IA anesthetic injection and those who received ≤50% relief. Preoperative radiographs were reviewed, and degree of osteoarthritis was determined using the Tonnis classification system. Outcomes were assessed with Modified Harris Hip Score and Hip Outcome Score (HOS). Univariate and multivariate models were performed to assess whether percent pain relief correlated with outcome. Results Of the 319 arthroscopic hip surgeries performed between 2007 and 2013, 115 (37%) patients were lost to follow‐up, 16 (5%) patients did not receive an IA injection, 16 (5%) patients had an injection containing gadolinium, and 40 (13%) patients completed injections at an outside institution. Five (2%) patients were excluded for a history of ipsilateral hip surgery, and 3 (1%) for a history of contralateral hip surgery, leaving 96 hips in 96 patients. There were 71 females (74%) and 25 males (26%) with a mean age of 37.6 ± 14.0 years. Tonnis was grade 0, 1, and 2 for 26 (27%), 55 (56%), and 16 (17%) patients, respectively. Fifty‐one (53%) of the injections contained a corticosteroid. The mean pain relief after IA injection was 73% ± 36% (range, 0% to 100%). Twenty‐six hips (26%) had ≤50% pain relief, whereas 70 (73%) had >50% pain relief, and the median time interval from injection to surgery was 3 (range, <1 to 20) months. Outcome scores were obtained at a mean 14.8 (range, 11 to 30) months after arthroscopic surgery. Postoperative mean Modified Harris Hip Score, HOS activities of daily living, and HOS‐Sport scores were 79.2 ± 17.3, 82.6 ± 17.3, and 67.4 ± 28.2, respectively. There was no statistical correlation between percent pain relief and outcome. There was no significant difference in outcome scores between those with ≤50% and >50% pain relief. Multivariate regression analysis showed no significant predictors of outcome, including age, gender, Tonnis grade, percent relief with IA injection, or type of surgery. Conclusions In this study of patients undergoing hip arthroscopy for labral pathology, our data indicate that the amount of pain relief from IA injection may be a poor predictor of short‐term outcome, even when adjusting for chondral degeneration. Although anesthetic injections can be an important diagnostic tool in select patients, a combination of the clinical history, physical examination, and imaging findings is fundamental. Level of Evidence Level IV, therapeutic case series.
Lateral Tibial Posterior Slope Is Increased in Patients With Early Graft Failure After Anterior Cruciate Ligament Reconstruction
Christensen, Joshua J., Krych, Aaron J. , Engasser, William M. , Vanhees, Matthias , Collins, Mark S., Dahm, Diane L., Krych, Aaron J

The American Journal of Sports Medicine | August 28, 2015 | Volume: 43 | Issue: 10 | Pages: 2510-2514

10.1177/0363546515597664 Get It

Background: The lateral tibial posterior slope (LTPS) has been reported in multiple studies to correlate with an increased risk for native anterior cruciate ligament (ACL) tearing. To date, no study has examined the effect of an increased LTPS as measured on magnetic resonance imaging (MRI) on the likelihood of ACL graft failure. Hypothesis: An increased LTPS as measured on MRI would correlate with an increased risk for ACL graft failure. Study Design: Case-control study; Level of evidence, 3. Methods: Fifty-eight patients were initially identified who experienced graft failure after primary ACL reconstruction and underwent revision between 1998 and 2009. Exclusion criteria were clinical follow-up of less than 4 years, graft failure occurring greater than 2 years after primary surgery, skeletal immaturity, deep infection, lack of available preoperative MRI, and history of trauma to the proximal tibia. This left 35 patients with early (within 2 years) failure of primary ACL reconstruction. These patients were matched to 35 control participants who had undergone ACL reconstruction with a minimum of 4 years of clinical follow-up and no evidence of graft failure. Patients were matched by age, sex, date of primary surgery, and graft type. The LTPS was then determined on MRI in a blinded fashion. Results: The mean time to failure in patients in the study group was 1 year (range, 0.6-1.4 years). The mean follow-up of those in the matched control group was 6.9 years (range, 4.0-13.9 years). The mean LTPS in the early ACL failure group was found to be 8.4°, which was significantly larger than that in the control group at 6.5° ( P = .012). The odds ratio for graft failure considering a 2° increase in the LTPS was 1.6 (95% CI, 1.1-2.2) and continued to increase to 2.4 (95% CI, 1.2-5.0) and 3.8 (95% CI, 1.3-11.3) with 4° and 6° increases in the LTPS, respectively. No significant association was identified between graft type and graft failure. Conclusion: An increased LTPS is associated with an increased risk for early ACL graft failure, regardless of graft type. Orthopaedic surgeons should consider measuring the LTPS as part of the preoperative assessment of ACL-injured patients.
Does Relief from Intra-articular Anesthetic Injection Predict Outcome after Hip Arthroscopy?
Engasser, William M. , Sousa, Paul L., King, Alexander H. , Levy, Bruce A. , Krych, Aaron J. , Sierra, Rafael J.

Orthopaedic Journal of Sports Medicine | March 29, 2015 | Volume: 3 | Issue: 3_suppl | Pages: No page available

10.1177/2325967115s00018 Get It

Objectives: Intra-articular (IA) anesthetic injection is commonly performed as a diagnostic test in the setting of femoroacetabular impingement (FAI). Currently, there is a paucity of data correlating post-injection pain relief and outcomes after hip arthroscopy for FAI. The purpose of this study is to determine whether the amount of pain relief after IA injection predicts clinical and functional outcomes following hip arthroscopy. We hypothesize that increased pain relief (>50%) will correlate with better outcomes after surgery. Methods: The records of patients undergoing hip arthroscopy for FAI at our institution between April 2007 and April 2012 were reviewed. We identified patients who underwent IA injection and subsequent hip arthroscopy. Inclusion criteria were: ultrasound or fluoroscopic guided intra-articular anesthetic injection performed at our institution, prospectively documented pre- and post-injection Numerical Rating Scale (NRS) pain scores, no prior ipsilateral hip surgery, and minimum 1 year follow-up. Pre-operative radiographs were reviewed and degree of osteoarthritis was determined using the Tonnis classification system. Outcomes were assessed with Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). Univariate and multivariate models were performed to assess whether percent pain relief correlated with outcome scores. Results: 99 hips in 96 patients met our inclusion criteria and included 71 females (74%) and 25 males (26%) with a mean age of 37.5 ± 14.0 years. 26 patients had Tonnis grade 0, 55 had grade 1, and 18 had grade 2 (0 grade 3). Mean pain relief after IA injection was 73.6 ± 36.1 (range 0-100) percent. 26 patients (26%) had ≤50% pain relief while 73 (74%) had >50% pain relief. Outcome scores were obtained at a mean 14.9 months. Mean MHHS, HOS-ADL, and HOS-Sport scores were 79.2 ± 17.3, 82.6 ± 17.3, and 67.4 ± 28.2, respectively. There was no statistical correlation between percent pain relief and MHHS, HOS-ADL, or HOS-Sport scores. There was no significant difference in outcome scores between those with ≤50% and >50% pain relief. While patients that received >50% pain relief by IA injection were more likely to achieve positive results (MHHS >70) with a likelihood ratio of 1.23 (95% CI 0.92-1.53), this was not significant. Multivariate regression analysis demonstrated no significant predictors of outcome, including age, gender, Tonnis grade, percent relief with IA injection, number of months postoperatively, or type of surgery. Conclusion: In patients undergoing hip arthroscopy for FAI, our data indicates that the amount of pain relief from IA injection is a poor predictor of short term outcome, even when adjusting for chondral degeneration. While anesthetic injections can be an important diagnostic tool in select patients, correlation of the clinical history, physical examination, and imaging findings are fundamental. In addition, outcome following hip arthroscopy remains multifactorial.
Medial Patellofemoral Ligament Tears in the Setting of Multiligament Knee Injuries Rarely Cause Patellar Instability
Allen, B J, Krych, Aaron J. , Engasser, William M. , Levy, Bruce A. , Collins, Mark S., Dahm, Diane L., Allen, Benjamin J, Engasser, William, Allen, Benjamin J., Stuart, Michael J. , Krych, Aaron J

The American Journal of Sports Medicine | March 26, 2015 | Volume: 43 | Issue: 6 | Pages: 1386-1390

10.1177/0363546515576902 Get It

Background: Multiligament knee injuries (MLKIs) can also involve the medial patellofemoral ligament (MPFL), but there is a paucity of information regarding prevalence and relevance of MPFL involvement in this setting. Purpose: (1) To identify the prevalence of MPFL injury in MLKIs, (2) to determine whether an MPFL tear results in symptomatic patellar instability, and (3) to report clinical and functional outcomes of patients with and without MPFL tears after MLKI surgical reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: The records of all patients who underwent surgical reconstruction of MLKI (defined as a grade 3 injury of ≥2 ligaments) at a single institution from 2007 to 2010 were reviewed. Age, sex, knee dislocation classification (according to Schenck), and MRI findings were documented. All preoperative MRI scans were reviewed by an experienced musculoskeletal radiologist to determine the presence or absence of MPFL involvement. If an MPFL tear was present, its anatomic location and severity as well as the presence of patellar or lateral femoral condyle bone bruises were documented. Inclusion criteria included (1) MLKI treated at a single institution, (2) presence of MPFL tear on preoperative MRI, and (3) minimum 2-year clinical follow-up. Patellar instability symptoms were assessed with the Kujala Knee Questionnaire. Functional outcomes were measured using the International Knee Documentation Committee (IKDC) score. IKDC scores were compared between patients who sustained MLKIs with and without MPFL tears. There were 21 patients in each group. Results: Over the 4-year study period, 30 of 51 patients (59%) treated surgically for a MLKI had MRI evidence of an MPFL tear. Nine were lost to follow-up, leaving 21 patients for review. There were 13 complete (62%), 5 high-grade partial (24%), and 3 partial (14%) MPFL tears. Sixteen of 21 tears (76%) occurred at the proximal third, with the remainder exhibiting diffuse signal abnormality consistent with tearing throughout the length of the MPFL. The superficial medial collateral ligament was involved in all patients. In no case was the MPFL repaired or reconstructed. At mean follow-up of 3.6 years (range, 2.0-5.7 years), only 1 of 21 patients (5%) complained of patellofemoral instability symptoms whereas 20 of 21 patients (95%) did not experience patellar subluxation or dislocation. No significant difference was found when IKDC scores were compared between patients with and without an MPFL tear (mean ± SD, 65.5 ± 22.9 vs 79.4 ± 16.1; P = .07). Conclusion: MPFL tears occur frequently in patients with MLKI but rarely cause instability. In the majority of cases, MPFL tears do not need to be addressed at the time of surgery.
Does Relief from Intra-articular Anesthetic Injection Predict Outcome after Hip Arthroscopy?
Engasser, William M. , Kuzma, Scott A., Levy, Bruce A. , Krych, Aaron J.

Orthopaedic Journal of Sports Medicine | August 2, 2014 | Volume: 2 | Issue: 7_suppl2 | Pages: No page available

10.1177/2325967114s00091 Get It

Objectives: Arthroscopy is being used more frequently as a treatment for intra-articular hip pathology due to femoroacetabular impingement (FAI). Prior to surgery, intra-articular anesthetic injection is commonly performed as a diagnostic test to localize the source of pain. Currently, there is a paucity of data correlating post-injection pain relief and functional outcomes after hip arthroscopy for FAI. The purpose of this study is to determine whether the amount of pain relief after preoperative intra-articular anesthetic injection predicts clinical and functional outcomes following hip arthroscopy with minimum one year follow-up. We hypothesize that increased pain relief (>50%) will correlate with better outcomes after surgery. Methods: The records of patients undergoing hip arthroscopy for FAI at our institution between April 2007 and April 2012 were reviewed. We identified patients who underwent pre-operative intra-articular anesthetic injection and subsequent hip arthroscopy. Inclusion criteria were: ultrasound or fluoroscopic guided intra-articular anesthetic injection performed at our institution, documented pre- and post-injection Numerical Rating Scale (NRS) pain scores, no prior ipsilateral hip surgery, and minimum 1 year follow-up. Pre-operative radiographs were reviewed and degree of osteoarthritis was determined using the Tonnis classification system. Outcomes were assessed with Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). Univariate and multivariate models were performed to assess whether percent pain relief correlated with outcome scores. Results: 57 hips in 55 patients met our inclusion criteria and included 37 females (67%) and 18 males (33%) with a mean age of 42.6 ± 14.7 (range 15-68) years. 8 patients had Tonnis grade 0, 35 had Tonnis grade 1, and 14 had Tonnis grade 2. Mean pain relief after intra-articular injection was 74.4 ± 31.9 (range 0-100) percent. 13 patients (23%) had ≤50% pain relief while 44 (77%) had >50% pain relief. Outcome scores were obtained at a mean 25.5 (range 12- 60) months. Mean MHHS, HOS-ADL, and HOS-Sport scores were 82.1 ± 17.4 (range 42.9-100), 85.0 ± 16.6 (range 39.7-100), and 71.8 ± 28.1 (range 11.1-100) respectively. There was no correlation between percent pain relief and MHHS, HOS-ADL, or HOS-Sport scores. There was no significant difference in outcome scores between those with ≤50% and >50% pain relief. When adjusting for Tonnis grade there was no correlation between percent relief and any of the outcome scores measured. Conclusion: In patients undergoing hip arthroscopy for FAI, our data indicates that the amount of pain relief from intra-articular anesthetic injection does not correlate with minimum 1 year clinical and functional outcomes even when adjusting for Tonnis grade. Although pain relief did not predict outcomes in our study, we still believe it is a useful diagnostic tool to localize the source of pain in patients considering hip arthroscopy.
Lateral Tibial Slope is Increased with Patients with Early Graft Failure Following ACL Reconstruction
Christensen, Joshua J., Engasser, William M. , Collins, Mark S., Dahm, Diane L., Vanhees, Matthias

Orthopaedic Journal of Sports Medicine | August 2, 2014 | Volume: 2 | Issue: 7_suppl2 | Pages: No page available

10.1177/2325967114s00047 Get It

Objectives: To determine the relationship between lateral tibial slope and probability of early graft failure in patients who have undergone anterior cruciate ligament (ACL) reconstruction. Methods: Fifty-eight patients were initially identified who experienced graft failure following primary ACL reconstruction and were revised between 1989 and 2009. Exclusion criteria were: clinical follow-up of less than four years, graft failure occurring greater than two years from primary surgery, skeletal immaturity, deep infection, lack of availability of preoperative MRI imaging, and history of previous trauma to the proximal tibia. This left 35 cases of early (within 2 years) failure of primary ACL reconstruction. These cases were matched to 35 controls that had undergone ACL reconstruction with a minimum of 4 years of clinical follow-up and no evidence of graft failure. Patients were matched by age, gender, date of primary surgery, and graft type. Lateral tibial slope was then determined on MRI imaging in blinded fashion. Results: All 35 cases failed within 2 years of primary ACL reconstruction. Mean time to failure in this group was 1 year (range 0.6-1.4 years). Mean follow-up of the matched control group was 6.9 years (range 4.0-13.9 years). Mean lateral tibial slope in the early ACL failure group was found to be 8.4 degrees, which was significantly larger than the control group at 6.5 degrees (p=0.02). The odds ratio for failure considering a 2 degree increase in tibial slope was 1.5 (95% CI 1.02-2.2), and continued to increase to 2.2 (95% CI 1.1-4.6) and 3.3 (95% CI 1.1-10) with 4 degree and 6 degree increases in tibial slope, respectively (Fig 1). No significant association was identified between graft type and primary ACL reconstruction failure. Conclusion: Increased lateral tibial slope is associated with an increased risk for early ACL graft failure, regardless of graft type. Orthopaedic surgeons should consider measuring lateral tibial slope as part of the preoperative assessment of ACL-injured patients.
Reconstruction of the Posterolateral Corner of the Knee With Achilles Tendon Allograft
Kuzma, Scott A., Chow, Roxanne M., Engasser, William M. , Levy, Bruce A. , Stuart, Michael J.

Arthroscopy Techniques | June 16, 2014 | Volume: 3 | Issue: 3 | Pages: No page available

10.1016/j.eats.2014.02.006 Get It

Abstract Posterolateral corner injuries of the knee are relatively rare; however, they can result in significant long‐term disability without appropriate treatment. They often occur in the setting of multiligament knee injuries, and as a result, diagnosis and management can be challenging. Severe injuries often require reconstruction, and both anatomic and nonanatomic techniques exist. We describe our preferred operative technique to reconstruct the fibular collateral ligament and posterolateral corner using a single Achilles tendon allograft. Technique Video video See video under supplementary data.
Arthroscopic Capsular Repair in the Treatment of Femoroacetabular Impingement
Chow, Roxanne M., Engasser, William M. , Krych, Aaron J. , Levy, Bruce A. , Krych, Aaron J

Arthroscopy Techniques | December 7, 2013 | Volume: 3 | Issue: 1 | Pages: No page available

10.1016/j.eats.2013.08.006 Get It

Abstract The role of capsular repair in the arthroscopic treatment of femoroacetabular impingement remains poorly defined. Some surgeons rarely repair the capsule, whereas others perform repairs routinely. There is little direct clinical evidence to guide surgeon decision making. When capsular repairs are performed, the procedure requires adequate visualization and careful suture placement either to re‐establish the patient's normal capsular volume or to plicate a redundant capsule in a hip with hyperlaxity preoperatively. We present our preferred technique for arthroscopic capsular repair. Technique Video video See video under supplementary data.
A comprehensive five‐phase rehabilitation programme after hip arthroscopy for femoroacetabular impingement
Spencer-Gardner, Luke , Eischen, Joseph J., Levy, Bruce A. , Engasser, William M. , Krych, Aaron J. , Sierra, Rafael J. , Krych, Aaron J

Knee Surgery, Sports Traumatology, Arthroscopy | September 27, 2013 | Volume: 22 | Issue: 4 | Pages: 848-859

10.1007/s00167-013-2664-z Get It

Abstract Purpose Recent advancements in the understanding of hip biomechanics have led to the development of techniques to remove bony impingement and repair and/or preserve the labrum during hip arthroscopy. Although much attention in the literature is devoted to diagnosis and treatment, there is little information about post‐operative rehabilitation. Therefore, the purpose of this review is to (1) provide a five‐phase rehabilitation protocol following arthroscopic treatment for FAI and (2) report clinical and functional outcomes of patients following this protocol at minimum 1‐year follow‐up, in order to provide the surgeon and therapist with a protocol that is supported by clinical data. Methods All consecutive patients undergoing hip arthroscopy and subsequent five‐phase rehabilitation protocol at a single institution from 1 April 2011 to 1 April 2012 were analysed. Inclusion criteria were as follows: no prior ipsilateral hip surgery, completion of the five‐phase rehabilitation protocol, minimum 1‐year follow‐up, and documented outcome scores. Prospective outcomes were assessed with modified Harris hip score (MHHS) and hip outcome score (HOS). Results Fifty‐two patients (19 male and 33 female) met the inclusion criteria with a median age of 42 (range 16–59) years. Mean MHHS, HOS‐ADL, and HOS‐sport scores at a mean 12.5 (range 12–15) months were 80.1 ± 19.9 (0–100), 83.6 ± 19.2 (13.2–100), and 70.3 ± 27.0 (0–100), respectively. Conclusion This five‐phase rehabilitation programme provides a framework where progression from surgery to increasing post‐operative activity level can take place in a predictable manner. Patients following this rehabilitation protocol after hip arthroscopy demonstrated satisfactory clinical and functional outcomes, validating its implementation. Level of evidence Case series, Level IV.