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    Robert Burks

    Few studies have investigated the influence of patient-specific variables or procedure-specific factors on the overall cost of anterior cruciate ligament reconstruction (ACLR) in an ambulatory surgery setting. To determine patient- and... more
    Few studies have investigated the influence of patient-specific variables or procedure-specific factors on the overall cost of anterior cruciate ligament reconstruction (ACLR) in an ambulatory surgery setting. To determine patient- and procedure-specific factors influencing the overall direct cost of outpatient arthroscopic ACLR utilizing a unique value-driven outcomes (VDO) tool. Cohort study (economic and decision analysis); Level of evidence, 3. All ACLRs performed by 4 surgeons over 2 years were retrospectively reviewed. Cost data were derived from the VDO tool. Patient-specific variables included age, body mass index, comorbidities, American Society of Anesthesiologists (ASA) classification, smoking status, preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Computerized Adaptive Testing (PF-CAT) score, and preoperative Single Assessment Numeric Evaluation (SANE) score. Procedure-specific variables included graft type, revision statu...
    To compare the biomechanics of a transosseous equivalent (TOE) repair using medial and lateral anchors with tape to a transosseous knotless (TOK) tape repair with only laterally placed intraosseous anchors. One of 2 different repairs were... more
    To compare the biomechanics of a transosseous equivalent (TOE) repair using medial and lateral anchors with tape to a transosseous knotless (TOK) tape repair with only laterally placed intraosseous anchors. One of 2 different repairs were performed on 8 paired specimens: (1) transosseous equivalent (TOE) tape repair or (2) transosseous knotless (TOK) tape repair. Specimens were mounted on a materials testing machine and loaded in uniaxial tension to measure cyclic construct gap formation, followed by failure testing. Paired t tests were used to compare gapping, ultimate stiffness, and failure loads. Fisher exact test was used to compare modes of failure (soft tissue failure vs construct failure). Peak cyclic gapping, failure stiffness, and ultimate failure loads did not differ between TOE and TOK repairs (P = .140 for gapping, P = .106 for stiffness, and P = .672 for peak failure loads). All TOK repairs failed via soft tissue failure medial to the medial suture line, with no constru...
    Acromioplasty has been proposed as a means of altering elevated critical shoulder angles (CSAs). We aimed to localize the critical acromion point (CAP) responsible for the acromial contribution of the CSA and determine whether resection... more
    Acromioplasty has been proposed as a means of altering elevated critical shoulder angles (CSAs). We aimed to localize the critical acromion point (CAP) responsible for the acromial contribution of the CSA and determine whether resection of the CAP can alter the CSA to a normal range. The CAP and 3-dimensional (3D) CSAs were determined on 3D computed tomography reconstructions of 88 cadaveric shoulders and compared with corresponding CSAs on digitally reconstructed radiographs. The position of the CAP was fluoroscopically isolated in 20 of these specimens and the resulting fluoroscopic CSA compared with the corresponding 3D CAP and 3D CSA. We investigated the CSA before and after a virtual acromioplasty of 2.5 and 5 mm at the CAP in specimens with a CSA greater than 35°. The mean CAP was 21% ± 10% of the acromial anterior-posterior length from the anterolateral corner. There was no difference between the mean 3D CSA and the CSA on digitally reconstructed radiographs (32° vs 32°, P = ...
    To evaluate the convergent validity, precision, and completion times for the Physical Function Computerized Adaptive Test (PF-CAT) in a sports medicine patient population relative to standard measures of knee and shoulder function. We... more
    To evaluate the convergent validity, precision, and completion times for the Physical Function Computerized Adaptive Test (PF-CAT) in a sports medicine patient population relative to standard measures of knee and shoulder function. We reviewed all patient visits from April through September 2014 with either knee or shoulder complaints from a university-based sports medicine clinic, during which PF-CAT, Single Assessment Numerical Evaluation (SANE), Simple Shoulder Test (SST), and American Shoulder and Elbow Surgeons (ASES) outcome scores for shoulder patients and PF-CAT, SANE, and International Knee Documentation Committee (IKDC) scores for knee patients were obtained, with an initial visit or one follow-up visit included in the study. Spearman correlation was used to evaluate pairwise agreement among scores. The McNemar χ(2) test was used to evaluate a difference in the number of times floor and ceiling values occurred. Wilcoxon signed rank tests were used to compare differences in...
    Background: Despite advances in surgical technique, rotator cuff repair retears continue to occur at rates of 10%, 22%, and 57% for small, medium, and large tears, respectively. A common mode of failure in transosseous-equivalent rotator... more
    Background: Despite advances in surgical technique, rotator cuff repair retears continue to occur at rates of 10%, 22%, and 57% for small, medium, and large tears, respectively. A common mode of failure in transosseous-equivalent rotator cuff repairs is tissue pullout of the medial mattress stitch. While the medial mattress stitch has been studied extensively, no studies have evaluated a vertical mattress pattern placed near the musculotendinous junction in comparison with a horizontal mattress pattern. Hypothesis: Vertical mattress stitches will have higher load to failure and lower gapping compared with horizontal mattress stitches in a transosseous-equivalent rotator cuff repair. Study Design: Controlled laboratory study. Methods: Double-row transosseous-equivalent rotator cuff repairs were performed in 9 pairs of human male cadaveric shoulders (mean age ± SD, 58 ± 10 years). One shoulder in each pair received a medial-row suture pattern using a vertical mattress stitch, and the ...
    Patellar instability is a common complaint after traumatic dislocation of the patella. Traumatic dislocation always leads to tearing of the medial patellofemoral ligament (MPFL). Treatment consists of recovery from the traumatic injury,... more
    Patellar instability is a common complaint after traumatic dislocation of the patella. Traumatic dislocation always leads to tearing of the medial patellofemoral ligament (MPFL). Treatment consists of recovery from the traumatic injury, followed by reconditioning and physical therapy to strengthen the dynamic stabilizers of the patella. In patients with recurrent instability, detailed evaluation of the cause is required to determine the needed interventions. In patients with an incompetent MPFL and recurrent instability, reconstruction is indicated, along with other procedures to address other contributing factors. This article details our technique for MPFL reconstruction using semitendinosus autograft, which can be performed alone or in concert with other realignment procedures.
    The purpose of this study was to investigate the intersurgeon variation in technical aspects of performing an arthroscopic Bankart repair. A unique approach with experienced equipment representatives from 3 different arthroscopic... more
    The purpose of this study was to investigate the intersurgeon variation in technical aspects of performing an arthroscopic Bankart repair. A unique approach with experienced equipment representatives from 3 different arthroscopic companies was used. Experienced representatives were identified by DePuy Mitek, Smith & Nephew, and Arthrex and filled out questionnaires on how their surgeons performed arthroscopic Bankart procedures. This was performed in a blinded fashion with no knowledge of the identities of the specific surgeons or representatives by us. A video on different aspects of the procedure was observed by each representative before filling out the questionnaire to help standardize responses. Data were collected using REDCap (Research Electronic Data Capture). Data were analyzed as an infrequent observation with 0% to 30% of representatives reporting the observation; sometimes, 31% to 70% reporting the observation; and often, greater than 70% of representatives reporting. Se...
    Criteria are needed for primary care providers such that they can evaluate age-related knee pain in a cost-effective manner. This study examined (1) in what percentage of patients are appropriate radiographic views of the knee ordered... more
    Criteria are needed for primary care providers such that they can evaluate age-related knee pain in a cost-effective manner. This study examined (1) in what percentage of patients are appropriate radiographic views of the knee ordered before magnetic resonance imaging (MRI) for knee pain, (2) specialists' retrospective evaluation for appropriate utilization of MRI in knee pain, and (3) in what manner would the MRIs have altered diagnosis and management of knee disorders. Primary care providers underuse appropriate radiographs-especially, flexion weightbearing posteroanterior films-and overuse MRIs when evaluating older patients with knee pain. Case control. The authors performed a retrospective analysis of 100 patients older than 40 years with knee MRIs. Patient encounters with primary care physicians were reviewed. Given available information, specialists then formulated a pre- and post-MRI diagnosis and treatment plan and indicated whether the MRI would have altered their trea...
    Arthroscopy is considered a relatively new technique for the surgical repair of an unstable shoulder. Shoulder arthroscopy has grown in popularity and is considered the gold standard for treating carefully selected patients. Despite its... more
    Arthroscopy is considered a relatively new technique for the surgical repair of an unstable shoulder. Shoulder arthroscopy has grown in popularity and is considered the gold standard for treating carefully selected patients. Despite its increasing popularity, the procedure has a significant learning curve and has resulted in early higher recurrence rates when compared with patients treated with open techniques. With the addition of newer instrumentation, the refinement of techniques, and additional capsular plication and tensioning, outcomes for patients treated with shoulder arthroscopy should continue to improve. A major distinguishing feature in selecting appropriate candidates for shoulder arthroscopy is whether there have been significant bone changes resulting from dislocation recurrence. Recurrent anterior dislocation may create an anterior glenoid rim fracture, erosion loss from multiple recurrences, and an impression defect on the posterior aspect of the humeral head. The l...
    Introduction:Given that factors like center of rotation (COR), neck shaft angle, glenosphere diameter and component tilt alter the biomechanics of reverse total shoulder arthroplasty (rTSA), the pe...
    Research Interests:
    Scapular notching is a complication of reverse total shoulder arthroplasty (rTSA) that results in bone loss on the lateral border of the scapula. Notching has been reported in up to 86% of patients at 5 year follow-up [1], and is graded... more
    Scapular notching is a complication of reverse total shoulder arthroplasty (rTSA) that results in bone loss on the lateral border of the scapula. Notching has been reported in up to 86% of patients at 5 year follow-up [1], and is graded 1–4 as a function of progressive bone loss [2]. Notching may arise from impingement, erosion, periprosthetic osteolysis, stress shielding or a combination of these [1]. Glenosphere position can mitigate notching by limiting hardware impingement [3–5], but may increase the forces required to abduct the arm [6]. Clinicians might optimize patient range of motion and function via implant placement if susceptibility to notching was known a-priori.
    Continuous peripheral nerve block (CPNB) is an optimal choice for analgesia after orthopedic procedures, but is not commonly used in outpatients because of concern regarding the possibility of catheter-related complications. In addition,... more
    Continuous peripheral nerve block (CPNB) is an optimal choice for analgesia after orthopedic procedures, but is not commonly used in outpatients because of concern regarding the possibility of catheter-related complications. In addition, it may be difficult to provide adequate patient access to physicians in this setting. We present 620 outpatients who were treated with CPNB using an established protocol. All catheters were placed using direct ultrasound visualization. These patients received extensive oral and written preoperative instruction and were provided continuous telephone access to the anesthesiologist during the postoperative period. All patients were also contacted at home by telephone on the first postoperative day. In addition, each patient was seen and examined by the surgeon within 2 wk of hospital discharge. Of the 620 patients, there were 190 interscalene (brachial plexus), 206 fascia iliaca (femoral nerve), and 224 popliteal fossa (sciatic nerve) catheters. Two patients (0.3%) had complications related to the nerve block. In both of these patients, the symptoms resolved within 6 wk of surgery. Twenty-six patients (4.2%) required postoperative interventions by the anesthesiologist. One patient returned to the hospital for catheter removal. In this large series of outpatients treated with CPNB, there were surprisingly few interventions requiring an anesthesiologist. Likewise, patients were able to manage and remove their catheters at home without additional follow-up. This suggests that with adequate instruction and telephone access to health care providers, patients are comfortable with managing and removing CPNB catheters at home.
    Various surgical techniques exist for rotator cuff repair that provide a suitable environment for tendon-bone healing. Arthroscopic recreation of transosseous repairs, which had previously been performed by open or miniopen techniques,... more
    Various surgical techniques exist for rotator cuff repair that provide a suitable environment for tendon-bone healing. Arthroscopic recreation of transosseous repairs, which had previously been performed by open or miniopen techniques, can now be performed; however, arthroscopic, transosseous passage of suture material can be challenging technically. There are potential biologic and cost-saving advantages of arthroscopic transosseous rotator cuff repair that make an efficient and reproducible technique desirable for arthroscopists. The technique for arthroscopic transosseous rotator cuff repair using a knotless anchor-based system is demonstrated in the current Technical Note. Potential advantages of this construct include excellent biomechanics, enhanced footprint vascularization, and utility in poor bone quality while using minimal anchor numbers. Further studies will be needed to elucidate healing rates and clinical outcomes.
    1. J Bone Joint Surg Am. 1994 Jul;76(7):1077-9. Allograft reconstruction of the patellar ligament. A case report. Burks RT, Edelson RH. Division of Orthopedic Surgery, University of Utah, Salt Lake City 84132. PMID: 8027118 [PubMed -... more
    1. J Bone Joint Surg Am. 1994 Jul;76(7):1077-9. Allograft reconstruction of the patellar ligament. A case report. Burks RT, Edelson RH. Division of Orthopedic Surgery, University of Utah, Salt Lake City 84132. PMID: 8027118 [PubMed - indexed for MEDLINE]. Publication Types: ...
    We evaluated patellar tracking in six cadaveric knees with the medial restraints intact and then sectioned to determine their contribution to lateral translation of the patella with and without a lateral force on the patella. The medial... more
    We evaluated patellar tracking in six cadaveric knees with the medial restraints intact and then sectioned to determine their contribution to lateral translation of the patella with and without a lateral force on the patella. The medial patellofemoral ligament was then reconstructed with a gracilis tendon graft and patellar tracking was again evaluated. The knees were extended using a materials testing machine, and patellar tracking was measured with a position sensing system. With no lateral force applied to the patella, patellar tracking was unaffected by the presence or absence of the medial restraints or by reconstruction of the medial patellofemoral ligament. With a lateral force applied to the patella, patellar tracking was changed significantly by the loss of the medial restraints. Normal patellar tracking was substantially restored by reconstruction of the medial patellofemoral ligament.
    This study evaluated the clinical outcome in 21 patients (22 knees) undergoing osteochondral autologous transplantation (OATS) in the knee over a 5-year period. Sixteen knees in 15 patients were available for follow-up at an average of 40... more
    This study evaluated the clinical outcome in 21 patients (22 knees) undergoing osteochondral autologous transplantation (OATS) in the knee over a 5-year period. Sixteen knees in 15 patients were available for follow-up at an average of 40 months after the procedure. The clinical outcome was analyzed using the IKDC and Knee and Osteoarthritis Outcome Score (KOOS) evaluation forms, a subjective questionnaire, and a clinical examination. At final follow-up, the average KOOS result for pain was 80.6 (range: 56-94), symptoms 53.6 (range: 25-71), function of activities of daily living 93.4 (range: 79-100), function of sports and recreational activities 65.3 (range: 20-100), and quality of life 51.0 (range: 6-88). The average IKDC score was 68.2. On our subjective questionnaire, the average preoperative grade given was 3.1 (range: 1-7) with an improvement at the most recent follow-up to a grade of 8.0 (range: 5-10) (P < .00001). Thirteen (86%) patients reported that they would have the surgery again if they had to make the decision a second time. Age did not correlate with subjective results on the IKDC evaluation (P = .7048) or score difference on our questionnaire (P = .9175). This procedure provides an option for articular resurfacing of the femoral condyles for focal areas of chondral defects with promising results regarding subjective improvement.
    Patellofemoral instability has been a difficult problem to solve. Redislocation rates after nonoperative treatment of primary lateral patellar dislocation and of recurrent lateral patellar dislocation approach 17% and 50%, respectively.... more
    Patellofemoral instability has been a difficult problem to solve. Redislocation rates after nonoperative treatment of primary lateral patellar dislocation and of recurrent lateral patellar dislocation approach 17% and 50%, respectively. 1-6 The risk of recurrence appears to be higher in patients ...
    ABSTRACT
    Patients with shoulder and rotator cuff pathology who exhibit greater levels of psychological distress report inferior preoperative self-assessments of pain and function. In several other areas of orthopaedics, higher levels of distress... more
    Patients with shoulder and rotator cuff pathology who exhibit greater levels of psychological distress report inferior preoperative self-assessments of pain and function. In several other areas of orthopaedics, higher levels of distress correlate with a higher likelihood of persistent pain and disability after recovery from surgery. To our knowledge, the relationship between psychological distress and outcomes after arthroscopic rotator cuff repair has not been similarly investigated. (1) Are higher levels of preoperative psychological distress associated with differences in outcome scores (visual analog scale [VAS] for pain, Simple Shoulder Test, and American Shoulder and Elbow Surgeons score) 1 year after arthroscopic rotator cuff repair? (2) Are higher levels of preoperative psychological distress associated with less improvement in outcome scores (VAS for pain, Simple Shoulder Test, and American Shoulder and Elbow Surgeons score) 1 year after arthroscopic rotator cuff repair? (3) Does the prevalence of psychological distress in a population with full-thickness rotator cuff tears change when assessed preoperatively and 1 year after arthroscopic rotator cuff repair? Eighty-five patients with full-thickness rotator cuff tears were prospectively enrolled; 70 patients (82%) were assessed at 1-year followup. During the study period, the three participating surgeons performed 269 rotator cuff repairs; in large part, the low overall rate of enrollment was related to two surgeons enrolling only two patients total in the initial 14 months of the study. Psychological distress was quantified using the Distress Risk Assessment Method questionnaire, and patients completed self-assessments including the VAS for pain, the Simple Shoulder Test, and the American Shoulder and Elbow Surgeons score preoperatively and 1 year after arthroscopic rotator cuff repair. Fifty of 85 patients (59%) had normal levels of distress, 26 of 85 (31%) had moderate levels of distress, and nine of 85 (11%) had severe levels of distress. Statistical models were used to assess the effect of psychological distress on patient self-assessment of shoulder pain and function at 1 year after surgery. With the numbers available, distressed patients were not different from nondistressed patients in terms of postoperative VAS for pain (1.9 [95% confidence interval {CI}, 1.0-2.8] versus 1.0 [95% CI, 0.5-1.4], p = 0.10), Simple Shoulder Test (9 [95% CI, 8.1-10.4] versus 11 [95% CI, 10.0-11.0], p = 0.06), or American Shoulder and Elbow Surgeons scores (80 [95% CI, 72-88] versus 88 [95% CI, 84-92], p = 0.08) 1 year after arthroscopic rotator cuff repair. With the numbers available, distressed patients also were not different from nondistressed patients in terms of the amount of improvement in scores between preoperative assessment and 1-year followup on the VAS for pain (3 [95% CI, 2.2-4.1] versus 2 [95% CI, 1.4-2.9], p = 0.10), Simple Shoulder Test (5.2 [95% CI, 3.7-6.6] versus 5.0 [95% CI, 4.2-5.8], p = 0.86), or American Shoulder and Elbow Surgeons scale (38 [95% CI, 29-47] versus 30 [95% CI, 25-36], p = 0.16). The prevalence of psychological distress in our patient population was lower at 1 year after surgery 14 of 70 (20%) versus 35 of 85 (41%) preoperatively (odds ratio, 0.36; 95% CI, 0.17-0.74; p = 0.005). Mild to moderate levels of distress did not diminish patient-reported outcomes to a clinically important degree in this small series of patients with rotator cuff tears. This contrasts with reports from other areas of orthopaedic surgery and may be related to a more self-limited course of symptoms in patients with rotator cuff disease or possibly to a beneficial effect of rotator cuff repair on sleep quality or other unrecognized determinants of psychosocial status. Level I, prognostic study.
    PURPOSE Our study is designed to evaluate the evolving MRI appearance of the repaired rotator cuff, and to compare these findings to clinical outcomes. METHOD AND MATERIALS A prospective series of 40 patients with full-thickness rotator... more
    PURPOSE Our study is designed to evaluate the evolving MRI appearance of the repaired rotator cuff, and to compare these findings to clinical outcomes. METHOD AND MATERIALS A prospective series of 40 patients with full-thickness rotator cuff tear were selected for clinical and MRI evaluation after arthroscopic rotator cuff repair. MRI studies were performed preoperatively, at 6 weeks, 3 months and 1 year post repair. Postoperative scans were evaluated by two musculoskeletal radiologists for the following: 1) size of repaired footprint compared to anatomic footprint, 2) average tendon thickness at the site of repair compared to preoperative thickness, 3) signal intensity of the repaired tendon, 4) presence of full-thickness tear. A four-tiered grading criteria was established for each of the first 3 criterion. The sum of these three grades was designated the “rotator cuff score”. Pre- and postoperative clinical evaluations using the Constant score at 3 and 12 months were performed by...
    The femoral, lateral femoral cutaneous, and obturator nerves (ONs) can reportedly be blocked using a single-injection deep to the fascia iliaca (FI) at the level of the inguinal ligament. Two commonly used methods (the FI compartment and... more
    The femoral, lateral femoral cutaneous, and obturator nerves (ONs) can reportedly be blocked using a single-injection deep to the fascia iliaca (FI) at the level of the inguinal ligament. Two commonly used methods (the FI compartment and 3-in-1 blocks) have produced inconsistent results with respect to local anesthetic distribution and effect on the ON. To date, no study of either method has been performed using advanced imaging techniques to document both needle placement and local anesthetic distribution. We report the outcome of a series of 3-in-1 and FI blocks performed using ultrasound to guide needle position and magnetic resonance imaging (MRI) to define local anesthetic distribution. Patients were prospectively studied, and images were interpreted using a randomized and blinded protocol. The study was performed in the perioperative area of an academic orthopedic specialty hospital. Ten patients (ASA 1-2) having anterior cruciate ligament reconstruction received either 3-in-1...
    Few population-based studies have examined the incidence of meniscal injuries, and limited information is available on the influence of patient's demographic and occupational factors. To examine the incidence of meniscal injuries and... more
    Few population-based studies have examined the incidence of meniscal injuries, and limited information is available on the influence of patient's demographic and occupational factors. To examine the incidence of meniscal injuries and the influence of demographic and occupational factors among active-duty US service members between 1998 and 2006. Cohort study. Using the International Classification of Diseases (9th revision) codes 836.0 (medial meniscus), 836.1 (lateral meniscus), and 836.2 (meniscus unspecified), we extracted injury data from the Defense Medical Surveillance System to identify all acute meniscal injuries among active-duty military personnel. Active-duty military personnel serving in all branches of military service during the study period. Incidence rate (IR) per 1000 person-years at risk and crude and adjusted rates by strata for age, sex, race, rank, and service. During the study period, 100201 acute meniscal injuries and 12115606 person-years at risk for inju...
    No clear recommendations exist regarding optimal humeral component version and deltoid tension in reverse total shoulder arthroplasty (TSA). A biomechanical shoulder simulator tested humeral versions (0°, 10°, 20° retroversion) and... more
    No clear recommendations exist regarding optimal humeral component version and deltoid tension in reverse total shoulder arthroplasty (TSA). A biomechanical shoulder simulator tested humeral versions (0°, 10°, 20° retroversion) and implant thicknesses (-3, 0, +3 mm from baseline) after reverse TSA in human cadavers. Abduction and external rotation ranges of motion as well as abduction and dislocation forces were quantified for native arms and arms implanted with 9 combinations of humeral version and implant thickness. Resting abduction angles increased significantly (up to 30°) after reverse TSA compared with native shoulders. With constant posterior cuff loads, native arms externally rotated 20°, whereas no external rotation occurred in implanted arms (20° net internal rotation). Humeral version did not affect rotational range of motion but did alter resting abduction. Abduction forces decreased 30% vs native shoulders but did not change when version or implant thickness was altered. Humeral center of rotation was shifted 17 mm medially and 12 mm inferiorly after implantation. The force required for lateral dislocation was 60% less than anterior and was not affected by implant thickness or version. Reverse TSA reduced abduction forces compared with native shoulders and resulted in limited external rotation and abduction ranges of motion. Because abduction force was reduced for all implants, the choice of humeral version and implant thickness should focus on range of motion. Lateral dislocation forces were less than anterior forces; thus, levering and inferior/posterior impingement may be a more probable basis for dislocation (laterally) than anteriorly directed forces.
    ABSTRACT Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth... more
    ABSTRACT Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
    Patellar instability is a common complaint after traumatic dislocation of the patella. Traumatic dislocation always leads to tearing of the medial patellofemoral ligament (MPFL). Treatment consists of recovery from the traumatic injury,... more
    Patellar instability is a common complaint after traumatic dislocation of the patella. Traumatic dislocation always leads to tearing of the medial patellofemoral ligament (MPFL). Treatment consists of recovery from the traumatic injury, followed by reconditioning and physical therapy to strengthen the dynamic stabilizers of the patella. In patients with recurrent instability, detailed evaluation of the cause is required to determine the needed interventions. In patients with an incompetent MPFL and recurrent instability, reconstruction is indicated, along with other procedures to address other contributing factors. This article details our technique for MPFL reconstruction using semitendinosus autograft, which can be performed alone or in concert with other realignment procedures.
    Septic arthritis after arthroscopic anterior cruciate ligament reconstruction is rare, and the most appropriate treatment is unclear. Current recommendations are that, if the graft is removed, reimplantation should be delayed for 6 to 9... more
    Septic arthritis after arthroscopic anterior cruciate ligament reconstruction is rare, and the most appropriate treatment is unclear. Current recommendations are that, if the graft is removed, reimplantation should be delayed for 6 to 9 months. Early removal of the graft with appropriate infection management followed by early reimplantation can lead to good results. Uncontrolled retrospective review. Records of all patients who developed postoperative infection after anterior cruciate ligament reconstruction were reviewed. Four patients had early graft removal and appropriate infection management including 6 weeks of intravenous antibiotics followed by anterior cruciate ligament graft reimplantation within 6 weeks of completion of antibiotic therapy. Follow-up at an average of 21 months (range, 14 to 31) showed that the patients treated with early reimplantation had full symmetric knee range of motion and no effusion. The average modified Lysholm score was 92.5. Radiographs demonstr...
    The patient with meniscal injury may present with pain, swelling, or mechanical symptoms and often requires surgical intervention for symptom resolution. Treatment of such injuries relies on understanding the gross and microanatomic... more
    The patient with meniscal injury may present with pain, swelling, or mechanical symptoms and often requires surgical intervention for symptom resolution. Treatment of such injuries relies on understanding the gross and microanatomic features of the meniscus that are important in maintaining meniscal function. The ability of the meniscus to participate in load bearing, shock absorption, joint lubrication, and joint stability depends on the maintenance of its structural integrity. The diagnosis of meniscal injury often can be made by clinical evaluation utilizing the history, physical examination, and plain radiographs. Magnetic resonance imaging can be useful in confirming the diagnosis when clinical findings are inconclusive. Treatment depends on tear pattern, vascularity, and an assessment of tissue quality. Surgical decision making for the treatment of meniscal injury is based on patient factors and understanding of the meniscal structure, function, and pathology.
    We prospectively studied the natural history of untreated acute grade III acromioclavicular separations. Twenty-five patients were treated nonoperatively with a sling for comfort through progressive early range of motion as tolerated. Ten... more
    We prospectively studied the natural history of untreated acute grade III acromioclavicular separations. Twenty-five patients were treated nonoperatively with a sling for comfort through progressive early range of motion as tolerated. Ten additional uninjured subjects underwent strength testing to evaluate the difference between the dominant and nondominant sides so that patient data could be standardized. The patients were examined at intervals of 6, 12, 24, 36, and 52 weeks after injury, at which time they completed a subjective questionnaire and underwent isometric dynamometer testing as well as military press and bench press strength testing. One patient underwent a surgical procedure at 2 weeks after injury because of cosmetic concerns. Twenty of the 25 patients completed the 1-year evaluation and strength-testing protocol. Subjectively, 4 of the 20 patients (20%) thought that their long-term outcome was suboptimal, although for 3 of them it was not enough to warrant surgery. O...
    Using a dog model, we examined the influence of tendon length and fit within a bone tunnel on the pull-out strength of a tendon-bone tunnel complex at 6 weeks after fixation. Fourteen adult mongrel dogs (weight, 25 to 30 kg) underwent... more
    Using a dog model, we examined the influence of tendon length and fit within a bone tunnel on the pull-out strength of a tendon-bone tunnel complex at 6 weeks after fixation. Fourteen adult mongrel dogs (weight, 25 to 30 kg) underwent bilateral hindlimb surgery in which the extensor digitorum longus tendon was transplanted into an extraarticular metaphyseal bone tunnel. Our findings demonstrated that pull-out strength at 6 weeks was enhanced by increasing the length of tendon within the tunnel. The average load to failure with 1 cm of tendon within the tunnel was 153.7 +/- 78.6 N, compared with 265.5 +/- 93.3 N for the specimens with 2 cm of tendon in the tunnel. Tendon fit within the tunnel was also found to be important. The average load to failure when a tendon was placed in a 4.2-mm diameter tunnel was 301 +/- 61 N at 6 weeks. The average load to failure when the tendon was placed within a 6-mm diameter tunnel was 228 +/- 65 N. These differences were statistically different. His...
    The purpose of this investigation was to identify and quantify the soft tissue restraints, both medially and laterally, to lateral patellar translation. These restraints to lateral patellar translation at 20 degrees of knee flexion were... more
    The purpose of this investigation was to identify and quantify the soft tissue restraints, both medially and laterally, to lateral patellar translation. These restraints to lateral patellar translation at 20 degrees of knee flexion were tested biomechanically on a universal testing instrument in nine fresh-frozen cadaveric knees. After preconditioning the tissues, the patella of each intact knee was translated laterally to a distance at which a force of 200 N was recorded. This distance was used to translate the patella for the remaining structures to be sectioned. The contribution of each structure to the total restraining force was determined as the percent of the force to restrain the intact specimen by sectioning the restraints in a predetermined order. The contribution of each structure to the restraining force was defined as the difference between the restraining force before and after its sectioning. The medial patellofemoral ligament was found to be the primary restraint to ...
    Although greater trochanteric pain syndrome is thought to be a common musculoskeletal disorder, little has been reported on the incidence rates of the disorder. The purpose of this study was to determine the incidence and demographic risk... more
    Although greater trochanteric pain syndrome is thought to be a common musculoskeletal disorder, little has been reported on the incidence rates of the disorder. The purpose of this study was to determine the incidence and demographic risk factors of greater trochanteric pain syndrome in a United States military population. Multivariate Poisson regression analysis was used to estimate the rate of greater trochanteric pain syndrome per 1000 person-years, controlling for sex, race, age, rank, and branch of service. The overall unadjusted incidence rate of greater trochanteric pain syndrome was 2.03 per 1000 person-years. Women had a significantly increased adjusted incidence rate ratio for greater trochanteric pain syndrome of 5.03 (95% confidence interval [CI], 4.91-5.16). The adjusted incidence rate ratio for White servicemembers compared with Black servicemembers was 1.36 (95% CI, 1.32-1.40). The adjusted incidence rate ratio for the 40+ age group compared with the 25 to 29 age group was 2.81 (95% CI, 2.68-2.95). Compared with junior officers, junior and senior enlisted ranks had an increased adjusted incidence rate ratio of 1.94 (95% CI, 1.84-2.04) and 1.17 (95% CI, 1.12-1.23), respectively. Compared with the Navy, each branch of service had an increased adjusted incidence rate ratio, with the Army at 2.90 (95% CI, 2.80-3.01), the Marines at 1.96 (95% CI, 1.87-2.07), and the Air Force at 1.33 (95% CI, 1.27-1.38). Female servicemembers had a five-fold greater incidence of greater trochanteric pain syndrome. Increasing age, enlisted rank groups, and service in the Army, Marines, or Air Force were also significant risk factors.
    Transosseous-equivalent rotator cuff repair has an increased incidence of medial rotator cuff failure compared with single-row repair. No studies have evaluated the influence of the proximity of the suture row to the musculotendinous... more
    Transosseous-equivalent rotator cuff repair has an increased incidence of medial rotator cuff failure compared with single-row repair. No studies have evaluated the influence of the proximity of the suture row to the musculotendinous junction (MTJ) on cyclic gapping and failure properties. A single row of horizontal mattress sutures placed within the supraspinatus tendon lateral to the MTJ will experience less gap formation and higher failure loads than a similar suture row placed at the MTJ. Controlled laboratory study. Paired supraspinatus tendons were isolated from human cadaveric specimens and resected at the tendon insertion to the humerus. Randomized within a pair, a single row of 4 horizontal mattress sutures was placed either in the tendon 5 mm lateral to the MTJ or at the MTJ. The tied sutures secured the tendon to a fixture that ensured consistent placement of the suture row in the tendon and static fixation of the row. The muscle belly was gripped in a cryoclamp, and a servohydraulic materials testing machine was used to provide uniaxial tensile deformation for 500 cycles at 1 Hz, followed by load to failure at 1 mm/s. Fiducial markers with video tracking were used to quantify gap formation at the suture line, while the materials testing machine recorded loading for the cyclic and failure tests. During cyclic loading, both constructs experienced gross initial gap formation, followed by progressive gap formation that plateaued after cycle 200. The MTJ specimens had significantly higher mean cumulative gapping than the tendon specimens: 3.6±1.0 mm versus 2.4±0.6 mm, respectively (P=.012). The tendon specimens had significantly higher mean loads to failure than did the MTJ specimens: 567.1±121.8 N versus 434.2±148.1 N, respectively (P=.013). The mean failure displacement did not differ between groups for the tendon and MTJ: 5.7±2.5 mm versus 4.5±2.0 mm, respectively (P=.144). A horizontal suture row placed at the MTJ has inferior mechanical properties (increased gapping, decreased load support) as compared with a suture row placed 5 mm laterally within the tendon. The integrity of rotator cuff repair may be compromised if sutures are placed too close to the MTJ.
    Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment... more
    Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a ...
    Various reverse total shoulder arthroplasty (rTSA) implant options are available for the humeral and glenosphere components. This study used a cadaveric biomechanical shoulder simulator to evaluate how hardware configurations in 2 common... more
    Various reverse total shoulder arthroplasty (rTSA) implant options are available for the humeral and glenosphere components. This study used a cadaveric biomechanical shoulder simulator to evaluate how hardware configurations in 2 common rTSA systems affect (1) abduction/adduction range of motion (ROM), (2) rotational ROM, and (3) forces to elevate the arm. Seven pairs of shoulders were tested on a biomechanical shoulder simulator before and after rTSA implantation. The Aequalis Reverse Shoulder (Tornier, Edina, MN, USA) and the Reverse Shoulder Prosthesis (RSP; DJO Surgical, Austin, TX, USA) were implanted in opposing shoulders. Aequalis implant options included humeral polymer insert thickness and eccentricity and glenosphere tilt. RSP implant options included glenosphere diameter and lateralization, humeral shell offset, and polymer insert depth. Both the RSP and Aequalis shifted the center of rotation inferior and medially compared with native shoulders (P < .001). Increased ...
    In many areas of orthopaedics, patients with greater levels of psychological distress report inferior self-assessments of pain and function. This effect can lead to lower-than-expected baseline scores on common patient-reported outcome... more
    In many areas of orthopaedics, patients with greater levels of psychological distress report inferior self-assessments of pain and function. This effect can lead to lower-than-expected baseline scores on common patient-reported outcome scales, even those not traditionally considered to have a psychological component. This study attempts to answer the following questions: (1) Are higher levels of psychological distress associated with clinically important differences in baseline scores on the VAS for pain, the Simple Shoulder Test, and the American Shoulder and Elbow Surgeons score in patients undergoing arthroscopic rotator cuff repair? (2) Does psychological distress remain a negative predictor of baseline shoulder scores when other clinical variables are controlled? Eighty-five patients with full-thickness rotator cuff tears were prospectively enrolled. Psychological distress was quantified using the Distress Risk Assessment Method questionnaire. Patients completed baseline self-a...
    Reverse total shoulder arthroplasty is an effective procedure for treatment of glenohumeral joint disease among patients with severe rotator cuff deficiency. Improvements in prosthetic design are the result of an evolved understanding of... more
    Reverse total shoulder arthroplasty is an effective procedure for treatment of glenohumeral joint disease among patients with severe rotator cuff deficiency. Improvements in prosthetic design are the result of an evolved understanding of both shoulder and joint replacement biomechanics. Although modern generations of the reverse shoulder prosthesis vary in specific design details, they continue to adhere to Grammont's core principles demonstrated by his original Delta III prosthesis. This review article discusses the biomechanics of reverse total shoulder arthroplasty with a focus on elements of implant design and surgical technique that may affect stability, postoperative complications, and functional outcomes.
    Few population-based studies have examined the incidence of meniscal injuries, and limited information is available on the influence of patient's demographic and occupational factors. To examine the incidence of meniscal injuries and... more
    Few population-based studies have examined the incidence of meniscal injuries, and limited information is available on the influence of patient's demographic and occupational factors. To examine the incidence of meniscal injuries and the influence of demographic and occupational factors among active-duty US service members between 1998 and 2006. Cohort study. Using the International Classification of Diseases (9th revision) codes 836.0 (medial meniscus), 836.1 (lateral meniscus), and 836.2 (meniscus unspecified), we extracted injury data from the Defense Medical Surveillance System to identify all acute meniscal injuries among active-duty military personnel. Active-duty military personnel serving in all branches of military service during the study period. Incidence rate (IR) per 1000 person-years at risk and crude and adjusted rates by strata for age, sex, race, rank, and service. During the study period, 100201 acute meniscal injuries and 12115606 person-years at risk for inju...
    We sought to determine whether sex had a significant effect on the hematologic and serum chemistry analytes in adult sand rats (Psammomys obesus) maintained under normal laboratory conditions. According to the few data available for this... more
    We sought to determine whether sex had a significant effect on the hematologic and serum chemistry analytes in adult sand rats (Psammomys obesus) maintained under normal laboratory conditions. According to the few data available for this species, we hypothesized that levels of hematologic and serum chemistry analytes would not differ significantly between clinically normal male and female sand rats. Data analysis revealed several significant differences in hematologic parameters between male and female sand rats but none for serum biochemistry analytes. The following hematologic parameters were greater in male than in female sand rats: RBC count, hemoglobin, hematocrit, red cell hemoglobin content, and percentage monocytes. Red cell distribution width, hemoglobin distribution width, mean platelet volume, and percentage lymphocytes were greater in female than in male sand rats. The sex of adult sand rats is a source of variation that must be considered in terms of clinical and resear...
    Magnetic resonance imaging of the knee is expensive and is neither needed nor useful for all patients presenting with knee pain. Our objective was to determine the completeness of evaluation prior to ordering magnetic resonance imaging of... more
    Magnetic resonance imaging of the knee is expensive and is neither needed nor useful for all patients presenting with knee pain. Our objective was to determine the completeness of evaluation prior to ordering magnetic resonance imaging of the knee correlated to the ordering providers' postgraduate medical training and the rate of positive findings on the subsequent magnetic resonance imaging. Six hundred consecutive knee magnetic resonance images were reviewed, including 200 consecutive knee magnetic resonance imaging examinations from each of three provider types: orthopaedic surgeons, non-surgical physicians with sports medicine training, and primary care providers. Positive findings on magnetic resonance imaging were recorded as well as a history of present illness, a physical examination, and radiographs made prior to ordering magnetic resonance imaging of the knee. Patient and injury factors were recorded. Differences in patient factors, evaluation before magnetic resonance...
    This investigation sought to determine occupational outcomes after total knee arthroplasty (TKA) in a high-demand cohort. A total of 159 military servicemembers underwent 181 primary TKAs with mean follow-up of 4.1 (range, 2.0-6.6) years.... more
    This investigation sought to determine occupational outcomes after total knee arthroplasty (TKA) in a high-demand cohort. A total of 159 military servicemembers underwent 181 primary TKAs with mean follow-up of 4.1 (range, 2.0-6.6) years. Approximately 18% of servicemembers underwent medical separation from the military due to TKA-related limitations, and age <45years (OR=2.36; 95% CI: 1.14, 4.90) was established as the significant risk factor. Twenty servicemembers (12.6%) performed postoperative combat deployments, with age <45years (OR=3.10; 95% CI: 1.29, 7.47) or combat arms designation (OR=2.75; 95% CI: 1.13, 6.73) associated with higher rates of deployment. Nine revision TKAs (5.0%) were performed at an average of 1.9years. Following TKA, 82% of servicemembers remained on active-duty or completed their military service. Level of Evidence: IV.

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