➤ Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis. ➤ While generally considered an idiopathic phenomenon, various etiopathogenetic theories are being investigated, including local ischemia, aberrant endochondral ossification of the secondary subarticular physis, repetitive microtrauma, and genetic predisposition. ➤ Diagnosis is based on the history, physical examination, radiography, and advanced imaging, with elbow ultrasonography and novel magnetic resonance imaging protocols potentially enabling early detection and in-depth staging. ➤ Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy, and is typically nonoperative for stable lesions in skeletally immature patients and operative for those who have had failure of conservative management or have unstable lesions. ➤ Clinical practice guidelines have been limited by a paucity of high-level evidence, but a multicenter effort is ongoing to develop accurate and reliable classification systems and multimodal decision-making algorithms with prognostic value.

Background: Functional testing is used to assess anterior cruciate ligament (ACL) reconstruction rehabilitation, with the goal of symmetric ability. The pattern of change in the uninvolved limb’s function during rehabilitation is not established. Hypotheses: (1) Involved and uninvolved limb ability increases during rehabilitation, but the uninvolved limb ability increases to a lesser degree. (2) Hop tests will show larger initial asymmetry and will improve the most with rehabilitation. Study Design: Cohort study; Level of evidence, 3. Methods: This was a retrospective case series of 122 patients who underwent ACL reconstruction at our ambulatory surgery center and received multiple postoperative Standard Functional Tests (SFTs) between October 2009 and October 2013. Ten of the 12 individual tests within the SFT battery were analyzed. The patients’ earliest and latest SFTs were compared for changes in Limb Symmetry Index (LSI) and absolute function in each limb. We also analyzed the subgroup with SFTs (n = 38) at both 4 and 6 months postoperatively. Results: In all patients with multiple SFTs, involved limb performance increased in all tests except eyes-closed stork. Uninvolved limb performance increased in 4 SFT component tests and decreased in none. LSI significantly improved in 6 tests, all of which also showed involved limb improvement that was significant. Of these 6 tests, 5 showed initial LSI below 90%: single-leg squat, retro step-up, single-leg hop, crossover triple hop, and timed hop. Retro step-up and single-leg hop showed LSI improvements greater than 10 percentage points. In patients with 4- and 6-month data, involved limb performance increased in all tests except single-leg triple hop. Uninvolved limb performance increased in 5 SFT component tests and decreased in none. LSI significantly improved in 4 tests, all of which had initial LSI below 90%, and showed involved limb improvement that was significant. Retro step-up, single-leg hop, and crossover triple hop showed LSI improvements greater than 10 percentage points. Conclusion: During ACL reconstruction rehabilitation, LSI improvements indicated absolute increases in involved limb ability and were not attributable to uninvolved limb deterioration. The single-leg squat, retro step-up, single-leg hop, crossover triple hop, and timed hop are suggested as highly useful tests, since all showed initial LSI below 90%, with significant LSI improvement after rehabilitation.

Background: During anatomic anterior cruciate ligament (ACL) reconstruction, we have found that the femoral footprint can best be visualized from the anteromedial portal. Independent femoral tunnel drilling can then be performed through an accessory medial portal, medial and inferior to the standard anteromedial portal. Purpose: To compare the accuracy of independent femoral tunnel placement relative to the ACL footprint using an accessory medial portal versus tunnel placement with a traditional transtibial technique. Study Design: Controlled laboratory study. Methods: Ten matched pairs of cadaveric knees were randomized such that within each pair, one knee underwent arthroscopic transtibial (TT) drilling, and the other underwent drilling through an accessory medial portal (AM). All knees underwent computed tomography (CT) both preoperatively and postoperatively with a technique optimized for ligament evaluation (80 keV with maximum mAs). Computed tomography was performed with a dual-energy scanner. Commercially available third-party software was used to fuse the preoperative and postoperative CT scans, allowing anatomic comparison of the ACL footprint to the drilled tunnel. The ACL footprint was marked in consensus by an orthopaedic surgeon and a musculoskeletal radiologist and then compared with the tunnel aperture after drilling. The percentage of tunnel aperture contained within the native footprint as well as the distance from the center of the tunnel aperture to the center of the footprint was measured. Results: The AM technique placed 97.7% ± 5% of the tunnel within the native femoral footprint, significantly more than 61.2% ± 24% for the TT technique (P = .001). The AM technique placed the center of the femoral tunnel 3.6 ± 1.2 mm from the center of the native footprint, significantly closer than 6.0 ± 1.9 mm for the TT technique (P = .003). Conclusion: This study demonstrates that use of an accessory medial portal will facilitate more accurate placement of the femoral tunnel in the native ACL femoral footprint. Clinical Relevance: More accurate placement of the femoral tunnel in the native ACL femoral footprint should improve the ability to achieve more anatomic positioning of the ACL graft.

Insall–Salvati (IS) ratio, modified IS ratio (mIS), Caton–Deschamps (CD) index, and Blackburne–Peel (BP) index are patellar height measurements commonly made on lateral radiographs (XRs) in patients with patellofemoral instability. More recently, magnetic resonance imaging (MRI) has been used as an additional imaging modality to measure patellar height. However, different imaging modalities have not been previously compared for all of these measurements. First, to compare the patellar height measurements of IS, mIS, CD, and BP on XR and MRI in first-time lateral patellar dislocation (LPD) patients and a control population and, second, to evaluate for the effect of sex and skeletal maturity. All first-time LPD patients with both MRI and XR of the knee within 6 weeks of injury from 2008 to 2012 were included in the LPD group (n = 112). Patients without patellofemoral instability who underwent both MRI and XR of the knee served as controls (n = 129). Two independent observers measured patellar height. Mean values were compared among the radiographic modalities, sex, and skeletal maturity status. Interobserver reliability was assessed using intraclass correlation coefficients (ICCs). Patellar height in the LPD group measured greater on MRI than on XR for all four patellar height ratios (IS: 0.11; mIS: 0.07; CD: 0.18; BP: 0.08). In controls, MRI also demonstrated higher readings than XR on two indices (CD: 0.17; BP: 0.16). Skeletally immature patients measured higher than skeletally mature patients in the majority of the measurements by 0.12 to 0.20 on MRI and XR; the majority of the measurements showed no sex differences. ICC was excellent for IS on both MRI (ICC = 0.830) and XR (ICC = 0.849) and for CD on XR (ICC = 0.786). Patellar height measured greater on MRI than XR by approximately 0.10 across four patellar height measurement indices. Skeletally immature patients measured higher than skeletally mature on both MRI and XR, but sex did not have an effect. This is a retrospective cohort study and its level of evidence is 3.

Background: Arthroscopic suprapectoral and open subpectoral surgical techniques are both commonly utilized approaches for proximal biceps tenodesis of the long head of the biceps brachii. A central limitation to the widespread use of an arthroscopic approach for biceps tenodesis is that the tendon may be tenodesed too proximally in the bicipital groove, leading to persistent pain and tendinopathy. Purpose/Hypothesis: The purpose of this study was to determine the in vivo tenodesis location using arthroscopic suprapectoral and open subpectoral techniques for proximal biceps tenodesis in relation to clinically pertinent anatomic and radiographic landmarks. The null hypothesis was that arthroscopic suprapectoral biceps tenodesis would not be significantly different in terms of the location from open subpectoral biceps tenodesis. Study Design: Controlled laboratory study. Methods: A total of 20 matched pairs of cadaveric shoulder specimens were randomized such that within each pair, 1 shoulder underwent a standard open subpectoral biceps tenodesis and the other underwent an arthroscopic suprapectoral tenodesis. Limited dissection and exposure of the surgical tunnel site and reference landmarks were subsequently performed, and anteroposterior and lateral radiographs were obtained. Direct measurements were performed anatomically using a digital caliper and radiographically using picture archiving and communication system (PACS) software from the proximal lip of the humeral tunnel to regional landmarks. Results: Both techniques were able to place the humeral tunnel distal to the bicipital groove in all specimens. On average, the open subpectoral approach placed the tunnel 2.2 cm distal to the arthroscopic suprapectoral approach. Conclusion: The arthroscopic suprapectoral biceps tenodesis technique used in this study consistently placed the tenodesis tunnel distal to the bicipital groove, which may allay concerns about the bicipital groove as a pain source after this procedure. Clinical Relevance: This anatomic study provides new information on tunnel placement in 2 biceps tenodesis techniques. In addition, it provides clinically relevant anatomic and radiographic guidelines using clinically pertinent landmarks. This information may be useful in preoperative planning, intraoperative technique, and postoperative assessment of both open subpectoral and arthroscopic suprapectoral biceps tenodesis.