Tibial External Rotation Test for Patellar Instability.

BACKGROUND: There is no dynamic physical examination test that reproduces patellar instability or the effect of tibial rotation on patellar tracking. METHODS: This article describes a provocative physical examination test that can reproduce lateral patellar subluxation: the tibial external rotation test (TERT). The principle behind the TERT is to vary the quadriceps angle (Q-angle) by changing the rotation of the tibia with the knee at 90° of flexion and asking the patient to forcefully extend the knee against resistance. If the patella subluxates at about 25° of flexion when the tibia is held in the externally rotated position and the knee is extended against resistance (i.e., with an increased Q-angle) but is more stable when the same is done when the tibia is internally rotated, the test is positive. RESULTS: The TERT confirmed the diagnosis of patellar instability and helped determine if medialization of the tibial tubercle should be performed. CONCLUSIONS: The TERT is a provocative physical examination test that can cause the patella to subluxate laterally. The TERT can simulate the effect of medializing the tibial tubercle on patellar tracking. LEVEL OF EVIDENCE: Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.

Selecting the Next Class: The "Virtual Orthopaedic Rotation".

INTRODUCTION: When the COVID-19 pandemic forced the cancellation of visiting subinternships, we pivoted to create a virtual orthopaedic rotation (VOR). The purpose of this study was to assess the effect of the VOR on the residency selection process and determine the role of such a rotation in the future. METHODS: A committee was convened to create a VOR to replace visiting orthopaedic rotations for medical students who are interested in pursuing a career in orthopaedic surgery. The VOR was reviewed and sanctioned by our medical school, but no academic credit was granted. We conducted three 3-week VOR sessions. During each session, virtual rotators participated in regularly scheduled educational conferences and attended an invitation-only daily conference in the evenings that was designed for a medical student audience. In addition, students were paired with faculty and resident mentors in a structured mentorship program. Students' orthopaedic knowledge was assessed using prerotation and postrotation tests. RESULTS: From July to September 2020, 61 students from 37 distinct medical schools participated in the VOR. Notable improvements were observed in prerotation and postrotation orthopaedic knowledge test scores. In postrotation surveys, both students and faculty expressed high satisfaction with the curriculum but less certainty about how well they got to know each other. In the subsequent residency application cycle, 27.9% of the students who participated in the VOR were selected to interview, compared with 8.7% of the total application pool. DISCUSSION: The VOR was a valuable substitute for in-person clinical rotations during the COVID-19 pandemic. Although not likely to be a replacement for conventional away rotations, the VOR is a possible adjunct to in-person clinical rotations in the future.

Surgical Release of the Adductor Longus With or Without Sports Hernia Repair Is a Useful Treatment for Recalcitrant Groin Strains in the Elite Athlete.

BACKGROUND: Chronic strain and/or tendinopathy of the adductor longus tendon can be a cause of long-standing groin pain in the elite athlete, resulting in significant time lost from competition. Accurate diagnosis and treatment can expedite return to play. PURPOSE/HYPOTHESIS: To evaluate return to sport and performance in National Collegiate Athletic Association (NCAA) Division I football players and National Football League (NFL) players following adductor longus release with or without sports hernia repair. We hypothesized that adductor release will be an effective method of treatment for recalcitrant groin/adductor pain in these athletes. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A cohort study was performed of all NFL players and NCAA Division I college athletes who had undergone an adductor longus tendon release with or without sports hernia repair by 1 of 2 fellowship-trained orthopaedic surgeons between May 1999 and January 2013. All patients reported groin pain below the inguinal ligament and localized to their adductor longus. Symptoms lasted longer than 10 weeks and limited their ability to effectively perform during sport, as assessed by their coach and self-assessment. Questionnaires were given to all 26 patients to assess long-term surgical outcomes. A subgroup analysis was performed for NFL players, in which "performance scores" were calculated according to individual player statistics while playing. Scores obtained before the diagnosis of chronic adductor longus tendinopathy or strain were compared with those after surgery. Patients with prior abdominal or pelvic surgery, radiographic evidence of degenerative joint disease of the hip, labral tears or femoral acetabular impingement, prostatic or urinary tract disease, or nerve entrapment of the ilioinguinal, genitofemoral, or lateral femoral cutaneous nerves were excluded from the study. RESULTS: A total of 32 athletes underwent an adductor longus tenotomy during the study period. Of these patients, 28 were college- or professional-level athletes who underwent an adductor longus tenotomy, with a mean ± SD follow-up time of 6.2 ± 4.2 years (range, 12-178 months). Of the 32 patients, 20 had a concomitant sports hernia repair in addition to an adductor longus tenotomy. Thirty-one patients (97%) were able to return to their previous sport, and 30 (94%) were able to return at their previous level of play. Thirty patients (94%) reported that they were satisfied with their decision to have surgery. No player complained of weakness or a decrease in running speed or power. Mean return to play was 12 weeks from date of surgery. In the subgroup analysis of 16 NFL players, there were no statistically significant differences for the pre- versus postoperative comparisons of the athlete performance scores (P = .74) and the percentage of the games started versus played (P = .46). After separation of players who had a concomitant hernia repair from players who did not, there was no statistically significant difference in performance scores or percentages of games started. CONCLUSION: In this study of elite athletes, adductor longus tenotomy with or without a concomitant sports hernia repair provided overall acceptable and excellent results. Athletes were able to return to their previous level of athletic competition and performance with consistent relief of groin pain. Return to play in an NFL game averaged 12 weeks following surgery.

An in Vivo Simulation of Isometry of the Anterolateral Aspect of the Healthy Knee.

BACKGROUND: To assess the isometry of theoretical lateral extra-articular reconstruction (LER), we evaluated theoretical grafts attached to various points on the lateral femoral condylar area and to either Gerdy's tubercle or the anatomic attachment site of the anterolateral ligament to the tibia. METHODS: In 18 subjects, healthy knees with no history of either injury or surgery involving the lower extremity were studied. The subjects performed a sit-to-stand motion (from approximately 90° of flexion to full extension), and each knee was studied using magnetic resonance and dual fluoroscopic imaging techniques. The 3-dimensional wrapping paths of each theoretical LER graft were measured. Grafts showing the least change in length during the sit-to-stand motion were considered to be the most isometric. RESULTS: The most isometric attachment site on the lateral femoral epicondyle to either of the studied tibial attachment sites was posterior-distal to the femoral attachment site of the fibular collateral ligament. The LER graft had a mean change in length of approximately 3%. Moving the femoral attachment site anteriorly resulted in increased length of the graft with increasing flexion; more posterior attachment sites resulted in decreased length with increasing flexion. Moving the attachment site in the proximal-distal direction had a less profound effect. Moving the tibial attachment site from Gerdy's tubercle to the tibial attachment site of the anterolateral ligament affected the overall isometric distribution on the lateral femoral epicondyle. CONCLUSIONS: The most isometric attachment site on the femur for an LER would be posterior-distal to the femoral attachment site of the fibular collateral ligament. Different length changes for LER grafts were identified with respect to different femoral attachment sites. Desirable graft fixation locations for treating anterolateral rotatory instability were found posterior-proximal to the femoral fibular collateral ligament attachment. CLINICAL RELEVANCE: The present data could be used both in biomechanical studies and in clinical studies as guidelines for planning LER surgical procedures.

Tunnel position and graft orientation in failed anterior cruciate ligament reconstruction: a clinical and imaging analysis.

PURPOSE: It has been reported that technical error in positioning the graft tunnel is the most common problem in anterior cruciate ligament (ACL) reconstruction. The objective of this study was to quantitatively evaluate femoral and tibial tunnel positions and intra-articular graft orientation of primary ACL reconstruction in patients who had undergone revision ACL reconstruction. We postulated that this patient cohort had a nonanatomically positioned tunnel and graft orientation. METHODS: Twenty-six patients who had undergone a revision ACL were investigated. Clinical magnetic resonance (MR) images prior to revision were analysed. Three-dimensional models of bones and tunnels on the femur and tibia were created. Intra-articular graft orientation was measured in axial, sagittal and coronal planes. Graft positions were measured on the tibial plateau as a percentage from anterior to posterior and medial to lateral; graft positions on the femur were measured using the quadrant method. RESULTS: Sagittal elevation angle for failed ACL reconstruction graft (69.6° ± 13.4°) was significantly greater (p < 0.05) than that of the native anteromedial (AM) and posterolateral (PL) bundles of the ACL (AM 56.2° ± 6.1°, PL 55.5° ± 8.1°). In the transverse plane, the deviation angle of the failed graft (37.3° ± 21.0°) was significantly greater than native ACL bundles. The tibial tunnel in this patient cohort was placed posteromedially and medially to the anatomical AM and PL bundles, respectively. The femoral tunnel was placed anteriorly to the anatomical AM and PL bundles. CONCLUSIONS: This study reveals that both the tibial and femoral tunnel positions and consequently the intra-articular graft orientation in this patient group with failed ACL reconstruction were nonanatomical when compared with native ACL values. The results can be used to improve tunnel placement in ACL reconstruction.

Hamstring muscle strains in professional football players: a 10-year review.

BACKGROUND: Investigations into hamstring strain injuries at the elite level exist in sports such as Australian Rules football, rugby, and soccer, but no large-scale study exists on the incidence and circumstances surrounding these injuries in the National Football League (NFL). HYPOTHESIS: Injury rates will vary between different player positions, times in the season, and across different playing situations. STUDY DESIGN: Descriptive epidemiology study. METHODS: Between 1989 and 1998, injury data were prospectively collected by athletic trainers for every NFL team and recorded in the NFL's Injury Surveillance System. Data collected included team, date of injury, activity the player was engaged in at the time of injury, injury severity, position played, mechanism of injury, and history of previous injury. Injury rates were reported in injuries per athlete-exposure (A-E). An athlete-exposure was defined as 1 athlete participating in either 1 practice or 1 game. RESULTS: Over the 10-year study period 1716 hamstring strains were reported for an injury rate (IR) of 0.77 per 1000 A-E. More than half (51.3%) of hamstring strains occurred during the 7-week preseason. The preseason practice IR was significantly elevated compared with the regular-season practice IR (0.82/1000 A-E and 0.18/1000 A-E, respectively). The most commonly injured positions were the defensive secondary, accounting for 23.1% of the injuries; the wide receivers, accounting for 20.8%; and special teams, constituting 13.0% of the injuries in the study. CONCLUSION: Hamstring strains are a considerable cause of disability in football, with the majority of injuries occurring during the short preseason. In particular, the speed position players, such as the wide receivers and defensive secondary, as well as players on the special teams units, are at elevated risk for injury. These positions and situations with a higher risk of injury provide foci for preventative interventions.

Pathologic characteristics of the torn human meniscus.

BACKGROUND: Acellular meniscus tissue is at a high risk for degeneration and retear. Information that would help surgeons predict, preoperatively, or intraoperatively which torn menisci had few viable cells could be useful in deciding which patients might be at increased risk for retear and failure of surgical repair. HYPOTHESIS: Patient age, length of time since injury, and tear type are predictors of the cellularity of meniscus tissue. STUDY DESIGN: Descriptive laboratory study. METHODS: Gross and histologic evaluation of torn meniscus tissue from 44 patients and 10 control menisci was performed. RESULTS: The patient factors of age, time since injury, and tear type all had significant effects on the pathologic characteristics of the torn meniscus. Patients older than 40 years had lower cellularity in the torn menisci than did patients younger than 40 years (P < .01). As time since injury increased, so did the rates of DNA fragmentation in the midsubstance of the meniscus and rates of Outerbridge II changes in the adjacent cartilage. Worse meniscal histologic scores were found in menisci with degenerative and radial tear types. CONCLUSION: Patient age had a significant effect on the cellularity of the torn meniscus, with patients older than 40 years having significantly fewer meniscus cells than did those younger than 40 years. Further studies are needed to define the relative importance of the individual histologic findings in the clinical setting of meniscus tear and repair. CLINICAL RELEVANCE: In light of their decreased cellularity, menisci from patients older than 40 years may be more vulnerable to degeneration and retear after repair than are menisci of younger patients.

Arthroscopic versus open Bankart repair: analysis of patient subjective outcome and cost.

PURPOSE: Although the comparative efficacy of open and arthroscopic Bankart repair remains a matter of debate, little data exist on relative costs. We analyzed the patient outcomes, cost, and resource utilization of both procedures to determine if differences exist between open versus arthroscopic Bankart repair. TYPE OF STUDY: Retrospective case-control study. METHODS: We compared 22 patients who had open Bankart repair with 20 patients who had arthroscopic Bankart repair. Total operating times and all charges were obtained from records. Patients were evaluated using the American Shoulder and Elbow Surgeons (ASES) shoulder score, and any recurrence of dislocation was noted at minimum 24-month follow-up. RESULTS: For arthroscopic Bankart repairs, operating times were shorter, but operating room equipment charges were greater. Overall charges were greater for open repairs as all open repair patients were admitted postoperatively. ASES shoulder scores were not significantly different between treatment groups. Four of 17 evaluable patients with open Bankart repair (including 1 shoulder in a patient who underwent bilateral repairs) had recurrent dislocation. One of the 18 evaluable patients with arthroscopic Bankart repair had recurrent dislocation. CONCLUSIONS: Arthroscopic Bankart repair as same-day surgery has lower overall charges than open repair, although this difference would be negligible if all patients went home immediately after surgery. LEVEL OF EVIDENCE: Level III, therapeutic, retrospective cohort study.

Photochemical repair of Achilles tendon rupture in a rat model.

BACKGROUND: Photochemical tissue bonding (PTB) is an emerging technique for bonding or sealing tissue surfaces that requires light and a photoactive dye for its effect. The potential of PTB for tendon repair was assessed in a rat model. MATERIALS AND METHODS: The optical properties of bovine tendon were determined ex vivo to gauge the depth of light penetration as a function of wavelength and dosimetry parameters were established for PTB repair of ruptured tendon. PTB was then tested in vivo to repair transected tendons in Sprague-Dawley rats. Repair strengths were measured using a strain gauge up to 14 days post treatment. RESULTS: The effective penetration depth in tendon was estimated to be 0.68 mm at 514 nm. Following PTB treatment of mechanically ruptured tendon, significant bonding was dependent on the presence of both light and dye and attained a plateau strength at a fluence of 125 J/cm2. In a subsequent in vivo study to investigate PTB for repair of transected rat Achilles tendon, the ultimate stress required to break the repaired tendon was measured immediately after irradiation and at 7 and 14 days post-repair. Results showed that the difference in the ultimate stress between control and PTB treatment groups was statistically significant immediately after treatment and at 7 days (p = 0.04) but not 14 days (p = 0.75) post-repair. CONCLUSIONS: PTB provides a benefit to tendon repair at early stages in repair and is worthy of further investigation as a potential surgical adjunct for tendon repair in orthopedic surgeries.

The effect of posterior cruciate ligament reconstruction on patellofemoral contact pressures in the knee joint under simulated muscle loads.

BACKGROUND: The mechanism of cartilage degeneration in the patellofemoral joint (PFJ) and medial compartment of the knee following posterior cruciate ligament (PCL) injury remains unclear. PCL reconstruction has been recommended to restore kinematics and prevent long-term degeneration. The effect of current reconstruction techniques on PFJ contact pressures is unknown. PURPOSE: To measure PFJ contact pressures after PCL deficiency and reconstruction. METHOD: Eight cadaveric knees were tested with the PCL intact, deficient, and reconstructed. Contact pressures were measured at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion under simulated muscle loads. Knee kinematics were measured by a robotic testing system, and the PFJ contact pressures were measured using a thin film transducer. A single bundle achilles tendon allograft was used in the reconstruction. RESULTS: PCL deficiency significantly increased the peak contact pressures measured in the PFJ relative to the intact knee under both an isolated quadriceps load of 400 N and a combined quadriceps/hamstrings load of 400 N/200 N. Reconstruction did not significantly reduce the increased contact pressures observed in the PCL-deficient knee. CONCLUSION: The elevated contact pressures observed in the PCL-deficient knee and reconstructed knee might contribute to the long-term degeneration observed in both the non-operatively treated and PCL-reconstructed knees.

The biomechanical effect of posterior cruciate ligament reconstruction on knee joint function. Kinematic response to simulated muscle loads.

BACKGROUND: The effectiveness of posterior cruciate ligament reconstruction in restoring normal kinematics under physiologic loading is unknown. HYPOTHESIS: Posterior cruciate ligament reconstruction does not restore normal knee kinematics under muscle loading. STUDY DESIGN: In vitro biomechanical study. METHODS: Kinematics of knees with an intact, resected, and reconstructed posterior cruciate ligament were measured by a robotic testing system under simulated muscle loads. Anteroposterior tibial translation and internal-external tibial rotation were measured at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion under posterior drawer loading, quadriceps muscle loading, and combined quadriceps and hamstring muscle loading. RESULTS: Reconstruction reduced the additional posterior tibial translation caused by ligament deficiency at all flexion angles tested under posterior drawer loading. Ligament deficiency increased external rotation and posterior translation at angles higher than 60 degrees of flexion when simulated muscle loading was applied. Posterior cruciate ligament reconstruction reduced the posterior translation and external rotation observed in posterior cruciate ligament-deficient knees at higher flexion angles, but differences were not significant. CONCLUSION: Under physiologic loading conditions, posterior cruciate ligament reconstruction does not restore six degree of freedom knee kinematics. CLINICAL RELEVANCE: Abnormal knee kinematics may lead to development of long-term knee arthrosis.

Open repairs for the treatment of anterior shoulder instability.

Successful treatment of anterior instability of the shoulder requires a balance between restoring joint stability and minimizing loss of glenohumeral motion. The choice of treatment should be individualized on the basis of the patient's occupation and level of participation in sports, as well as on the degree of instability of the shoulder. Despite discussions to the contrary, there is no single "essential lesion," as proposed by Bankart, that is responsible for recurrent anterior shoulder instability, although the Bankart lesion is by far the most important. The choice of operative treatment must be tailored to correct the abnormality that is identified at the time of surgery. A variety of promising arthroscopic techniques have been developed for the treatment of anterior shoulder instability; however, open stabilization remains the standard, especially for severe instabilities, revision procedures, and for athletes who participate in contact sports. This article will review the open surgical techniques used for treatment of anterior instability of the shoulder. Both current and historical operations will be discussed. Regardless of which procedure is chosen by a surgeon, the treatment should follow the guidelines taught by Rowe: anatomic dissection at the time of surgery, identification and repair of the lesions responsible for the instability, returning tissues to their anatomic locations, and early postoperative range of motion. By following these guidelines, the results of treatment of anterior instability of the shoulder can be optimized.

Biomechanical consequences of PCL deficiency in the knee under simulated muscle loads--an in vitro experimental study.

The mechanism of chronic degeneration of the knee after posterior cruciate ligament (PCL) injury is still not clearly understood. While numerous biomechanical studies have been conducted to investigate the function of the PCL with regard to antero-posterior stability of the knee, little has been reported on its effect on the rotational stability of the knee. In this study, eight cadaveric human knee specimens were tested on a robotic testing system from full extension to 120 degrees of flexion with the PCL intact and with the PCL resected. The antero-posterior tibial translation and the internal-external tibial rotation were measured when the knee was subjected to various simulated muscle loads. Under a quadriceps load (400 N) and a combined quadriceps/hamstring load (400/200 N), the tibia moved anteriorly at low flexion angles (below 60 degrees). Resection of the PCL did not significantly alter anterior tibial translation. At high flexion angles (beyond 60 degrees), the tibia moved posteriorly and rotated externally under the muscle loads. PCL deficiency significantly increased the posterior tibial translation and external tibial rotation. The results of this study indicate that PCL deficiency not only changed tibial translation, but also tibial rotation. Therefore, only evaluating the tibial translation in the anteroposterior direction may not completely describe the effect of PCL deficiency on knee joint function. Furthermore, the increased external tibial rotations were further hypothesized to cause elevated patello-femoral joint contact pressures. These data may help explain the biomechanical factors causing long-term degenerative changes of the knee after PCL injury. By fully understanding the etiology of these changes, it may be possible to develop an optimal surgical treatment for PCL injury that is aimed at minimizing the long-term arthritic changes in the knee joint.

Virtual reality simulation of arthroscopy of the knee.

The virtual reality arthroscopic knee simulator (VR-AKS) consists of a computer platform, a video display, and two force-feedback (haptic) interfaces known as "PHANToMs" that also monitor the position of the instruments in the user's hands. The forces that the user would normally apply to the lower limb during arthroscopy are directed through an instrumented surrogate leg. Proprietary software provides the mathematical representation of the physical world and replicates the visual, mechanical, and behavioral aspects of the knee. This includes moderating the haptic interface and simultaneously executing a collision-detection algorithm that prevents the instruments from moving through "solid" surfaces. Modeling software interacts with this algorithm to send the appropriate images to the video display, including knee pathology such as meniscal tears and chondral defects as well as normal anatomy. Task-oriented programs monitor specific performance such as executing a proper examination of the knee or shaving a torn meniscus.