Comparative Outcomes Occur After Superficial Medial Collateral Ligament Augmented Repair vs Reconstruction: A Prospective Multicenter Randomized Controlled Equivalence Trial.

BACKGROUND: Although previous studies have reported good short-term results for superficial medial collateral ligament (sMCL) reconstruction, whether an augmented MCL repair is clinically equivalent remains unclear. PURPOSE/HYPOTHESIS: The purpose of this study was to compare clinical outcomes between randomized groups that underwent sMCL augmentation repair and sMCL autograft reconstruction. The hypothesis was that there would be no significant differences in objective or subjective outcomes between groups. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Patients were prospectively enrolled between 2013 and 2019 from 3 centers. Grade III sMCL injuries were confirmed via stress radiography. Patients were randomized to anatomic sMCL reconstruction versus augmented repair with surgical treatment, determined after examination under anesthesia confirmed sMCL incompetence. Postoperative visits occurred at 6 weeks and 6 months for repeat evaluation, with repeat stress radiography at final follow-up. Patient-reported outcome measures were obtained pre- and postoperatively at 6 months, 1 year, and final follow-up. The primary outcome measure was side-to-side difference on valgus stress radiographs at a minimum follow-up of 1 year. The two 1-sided t test procedure was used to test clinical equivalence for side-to-side difference in valgus gapping, and the Mann-Whitney U test was used to compare postoperative patient-reported outcome measures between groups. RESULTS: A total of 54 patients were prospectively enrolled into this study. Of these, 50 patients had 6-month stress radiograph data, while 40 had 1-year postoperative valgus stress radiograph data. The mean (SD) patient age was 38.0 years (14.2), and body mass index was 25.0 (3.6). Preoperative valgus stress radiographs demonstrated 3.74 mm (1.1 mm) of increased side-to-side gapping overall, while it was 4.10 mm (1.46 mm) in the MCL augmentation group and 3.42 mm (0.55 mm) in the MCL reconstruction group. Postoperative valgus stress radiographs at an average of 6 months were obtained in 50 patients after surgery, which showed 0.21 mm (0.81 mm) for the MCL augmentation group and 0.19 mm (0.67 mm) for the MCL reconstruction group (P = .940). At final follow-up (minimum 1 year), median (interquartile range) Lysholm scores were significantly higher in the reconstruction group (90 [83-99]) as compared with the repair group (80 [67-92]) (P = .031). Final International Knee Documentation Committee (IKDC) scores were also significantly higher for the reconstruction group (85 [68-89]) versus the repair group (72 [60-78] (P = .039). Postoperative Tegner scores were not significantly different between the repair group (5 [3.5-6]) and the reconstruction group (5.5 [4-7]) (P = .123). Patient satisfaction was also not significantly different between repair (7.5 [5.75-9.25]) and reconstruction groups (9.0 [7-10]) (P = .184). CONCLUSION: This study found no difference in objective outcomes between an sMCL augmentation repair and a complete sMCL reconstruction at 1 year postoperatively, indicating equivalence between these procedures. Patient-reported clinical outcomes favored the reconstruction over a repair. In addition, this study demonstrated that anatomic-based treatment of MCL tears with an early knee motion program had a very low risk of graft attenuation and a low risk of arthrofibrosis.

Axial-Oblique Versus Standard Axial 3-T Magnetic Resonance Imaging for the Detection of Trochlear Cartilage Lesions: A Prospective Study.

BACKGROUND: Imaging of the femoral trochlea has been inherently difficult because of its convex anatomy. PURPOSE/HYPOTHESIS: The purpose of this study was to compare the diagnostic utility of a standard axial magnetic resonance imaging (MRI) sequence with an axial-oblique MRI sequence of the knee for the detection of trochlear articular cartilage lesions on a high-field 3-T MRI scanner. We hypothesized that axial-oblique MRI scans of the knee obtained along the true axis of the trochlea would significantly improve the detection of high-grade cartilage lesions. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Patients who underwent MRI and subsequent surgery for any indication were prospectively enrolled into this study between June 2014 and February 2015. The articular cartilage of the trochlea was evaluated independently by 3 raters on axial and axial-oblique MRI and compared with arthroscopic findings (gold standard). The interrater and intrarater reliability of mild (International Cartilage Repair Society [ICRS] grades 1 or 2) and severe (ICRS grades 3 or 4) lesions on MRI were assessed as well as the sensitivity, specificity, positive predictive value, and negative predictive value. RESULTS: A total of 99 knees in 96 patients were included in the study. Interrater and intrarater agreement for the identification of severe lesions were moderate to good on the proximal trochlea and fair to moderate on the distal trochlea. No significant differences in sensitivity were found between axial and axial-oblique scans for any grade of lesion (55% vs 51%, respectively; P = .700) or for severe lesions (61% vs 52%, respectively; P = .289). Similarly, specificity for detecting severe lesions was not significantly different between axial and axial-oblique scans (95% vs 87%, respectively; P = .219). Last, no significant differences in sensitivity or specificity were found between MRI sequences when separately evaluating proximal and distal trochlear lesions (all P > .05). CONCLUSION: The axial-oblique sequence was unable to improve the sensitivity of MRI in detecting articular cartilage lesions on the trochlea. Both conventional axial and axial-oblique sequences, reviewed independently of the complete MRI series, had low sensitivity in detecting trochlear articular cartilage lesions. For this reason, clinicians should utilize all MRI planes to evaluate the articular cartilage of the trochlea. Future studies should focus on improving MRI techniques for detecting and characterizing cartilage lesions of the trochlea.

Direct versus indirect ACL femoral attachment fibres and their implications on ACL graft placement.

PURPOSE: To further elucidate the direct and indirect fibre insertion morphology within the human ACL femoral attachment using scanning electron microscopy and determine where in the footprint each fibre type predominates. The hypothesis was that direct fibre attachment would be found centrally in the insertion site, while indirect fibre attachment would be found posteriorly adjacent to the posterior articular cartilage. METHODS: Ten cadaveric knees were dissected to preserve and isolate the entirety of the femoral insertion of the ACL. Specimens were then prepared and evaluated with scanning electron microscopy to determine insertional fibre morphology and location. RESULTS: The entirety of the fan-like projection of the ACL attachment site lay posterior to the lateral intercondylar ridge. In all specimens, a four-phase architecture, consistent with previous descriptions of direct fibres, was found in the centre of the femoral attachment site. The posterior margin of the ACL attachment attached directly adjacent to the posterior articular cartilage with some fibres coursing into it. The posterior portion of the ACL insertion had a two-phase insertion, consistent with previous descriptions of indirect fibres. The transition from the ligament fibres to bone had less interdigitations, and the interdigitations were significantly smaller (p < 0.001) compared to the transition in the direct fibre area. The interdigitations of the direct fibres were 387 ± 81 µm (range 282-515 µm) wide, while the interdigitations of indirect fibres measured 228 ± 75 µm (range 89-331 µm). CONCLUSIONS: The centre of the ACL femoral attachment consisted of a direct fibre structure, while the posterior portion had an indirect fibre structure. These results support previous animal studies reporting that the centre of the ACL femoral insertion was comprised of the strongest reported fibre type. Clinically, the femoral ACL reconstruction tunnel should be oriented to cover the entirety of the central direct ACL fibres and may need to be customized based on graft type and the fixation device used during surgery.

Posteromedially placed plates with anterior staple reinforcement are not successful in decreasing tibial slope in opening-wedge proximal tibial osteotomy.

PURPOSE: To document the effectiveness of a novel technique to decrease tibial slope in patients who underwent a proximal opening-wedge osteotomy with an anteriorly sloped plate placed in a posteromedial position. The hypothesis was that posteromedial placement of an anteriorly sloped osteotomy plate with an adjunctive anterior bone staple on the tibia would decrease, and maintain, the tibial slope correction at a minimum of 6 months following the osteotomy. METHODS: All patients who underwent biplanar medial opening-wedge proximal tibial osteotomy with anterior staple augmentation to decrease sagittal plane tibial slope were included, and data were collected prospectively and reviewed retrospectively. Indications for decreasing tibial slope included medial compartment osteoarthritis with at least one of the following: ACL deficiency, posterior meniscus deficiency, or flexion contracture. Preoperative, immediate postoperative, and 6-month postoperative radiographs were reviewed. RESULTS: Twenty-one patients (14 males and 7 females) were included in the study with a mean age of 36.5 years. Intrarater and interrater reliability of slope measurements were excellent at all time points (ICC ≥ 0.94, ICC ≥ 0.85). The osteotomy resulted in an average tibial slope decrease of 0.8 from preoperative (n.s.). At 6-month postoperative, average slope was not significantly different from time-zero postoperative slope (mean = +0.2°). CONCLUSIONS: The most important finding of this study was that posteromedial placement of an anteriorly angled osteotomy plate augmented with an anterior staple during a biplanar medial opening-wedge proximal tibial osteotomy did not decrease sagittal plane tibial slope. Whether a staple was effective in maintaining tibial slope from time zero to 6 months postoperatively was unable to be assessed due to no significant change in tibial slope from the preoperative postoperative states. The results of this study note that current osteotomy plate designs and surgical techniques are not effective in decreasing sagittal plane tibial slope. LEVEL OF EVIDENCE: IV.

Patellofemoral Joint Reconstruction for Patellar Instability: Medial Patellofemoral Ligament Reconstruction, Trochleoplasty, and Tibial Tubercle Osteotomy.

Recurrent patellar instability can be very debilitating and may require surgical intervention. A thorough workup must be completed in this subset of patients. Risk factors for recurrent instability include patella alta, trochlear dysplasia, an increased tibial tubercle-trochlear groove distance, and insufficiencies in the medial retinacular structures. Necessary treatment of these risk factors, once identified, should be addressed surgically. Patellofemoral reconstruction must be individually tailored to each patient's anatomy and may necessitate medial patellofemoral ligament reconstruction, tibial tubercle osteotomy, or trochleoplasty in any combination or as a standalone procedure. This article details our technique for surgical treatment of recurrent patellar instability with a medial patellofemoral ligament reconstruction, an open trochleoplasty, and a tibial tubercle osteotomy for patients with severe trochlear dysplasia, an increased tibial tubercle-trochlear groove distance, or patella alta.

Radiographic Identification of Arthroscopically Relevant Acetabular Structures.

BACKGROUND: The anatomy of the acetabulum has been described extensively in the literature, but radiographic acetabular guidelines have not been well established. This study provides a radiographic map of acetabular landmarks in the hip. PURPOSE/HYPOTHESIS: The purpose of this study was to quantify the precise radiographic location of arthroscopic landmarks around the acetabulum. The hypothesis was that their locations were reproducible despite variability in the anatomy and positioning of pelvic specimens. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten fresh-frozen cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Anteroposterior (AP) and false-profile radiographs were obtained, and measurements were taken using a digital picture archiving and communication system. RESULTS: On AP radiographs, the direct and indirect heads of the rectus femoris were a mean 48.2 ± 4.6 mm and 44.7 ± 4.3 mm proximal to the teardrop line, respectively. The mean radiographic distance between their insertions was 5.0 ± 3.4 mm. Moreover, the anterior inferior iliac spine was a mean 11.5 ± 3.8 mm from the acetabular rim. On false-profile radiographs, the mean distance between the direct and indirect heads of the rectus femoris was 31.4 ± 6.2 mm. The mean distance between the superior margin of the anterior labral sulcus (the psoas-u) and the midpoint of the transverse acetabular ligament was 41.0 ± 5.7 mm. Additionally, the direct and indirect heads of the rectus femoris corresponded to the 2:30 and 1:30 locations on the acetabular clockface, respectively. The midpoint of the transverse acetabular ligament was located at 7 o'clock on the clockface. CONCLUSION: The most important finding of this study, determined by quantitative measurements, was that the described surgical landmarks had reliable locations on radiographs. Distances between landmarks as well as distances between landmarks and reference lines were reproducible in both AP and false-profile views. CLINICAL RELEVANCE: An understanding of how acetabular structures present on radiographs could lead to more accurate portal and hardware placement intraoperatively during arthroscopic surgery as well as better preoperative and postoperative assessments.

Radiographic Identification of Arthroscopically Relevant Proximal Femoral Structures.

BACKGROUND: Anatomic landmarks located on the proximal femur have only recently been defined, and there is a lack of radiographic guidelines for their locations presented in the literature. With the confident identification of these landmarks, radiographs could provide more assistance in preoperative evaluations, intraoperative guidance, and postoperative assessments. PURPOSE: To quantify the radiographic locations of endoscopic landmarks of the proximal femur. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Radiographs were obtained and measurements recorded in anteroposterior (AP) and Dunn 45° views. RESULTS: In the AP view, the gluteus medius insertion was located a mean 12.9 ± 2.4 mm and 34.7 ± 5.1 mm from the piriformis fossa and vastus tubercle, respectively. The piriformis fossa was a mean 14.8 ± 5.9 mm and 4.9 ± 1.9 mm from the anterior and posterior tips of the greater trochanter, respectively. The anterior and posterior tips of the greater trochanter were a mean 14.8 ± 5.1 mm from each other. In the Dunn 45° view, the piriformis fossa was a mean 13.3 ± 2.0 mm, and the vastus tubercle was a mean 21.5 ± 6.0 mm, from the gluteus medius insertion. Moreover, the vastus tubercle was a mean 33.5 ± 6.4 mm from the anterior tip of the greater trochanter and 31.6 ± 8.5 mm from the posterior tip of the greater trochanter. CONCLUSION: In spite of the variation in cadaveric sizes, quantitative descriptions of endoscopic landmarks were reproducible in clinical views. CLINICAL RELEVANCE: A detailed understanding of how the described landmarks present radiographically is relevant to preoperative planning, intraoperative evaluations, and postoperative assessments.

The Supine Internal Rotation Test: A Pilot Study Evaluating Tibial Internal Rotation in Grade III Posterior Cruciate Ligament Tears.

BACKGROUND: Biomechanical studies have reported that the posterior cruciate ligament (PCL) functions as a restraint against excessive tibial internal rotation at higher degrees of knee flexion. PURPOSE: To investigate the use of a supine internal rotation (IR) test for the diagnosis of grade III PCL injuries. The hypothesis was that internal rotation would be greater in patients with grade III PCL injuries compared with other knee injuries and that the supine IR test would demonstrate excellent diagnostic accuracy. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A consecutive series of 309 patients underwent arthroscopic and/or open knee ligament reconstruction surgery. Seven patients were excluded based on the inability to perform a side-to-side comparison of internal rotation. Tibial internal rotation was assessed bilaterally on 302 patients during examination under anesthesia by a single orthopaedic surgeon measuring tibial tubercle excursion (mm) while applying internal rotation torque. Internal rotation was graded from 0 to 4 at 60°, 75°, 90°, 105°, and 120° of knee flexion. Data were collected and stored prospectively. The optimal threshold for the supine IR test was chosen based on maximization of the Youden index. Diagnostic accuracy parameters were calculated. Multiple logistic regression models were constructed to assess the influence of other knee pathologies on diagnostic accuracy. RESULTS: Examination of the 22 PCL-deficient knees demonstrated an increase in tibial internal rotation at 60°, 75°, 90°, 105°, and 120° of knee flexion. The supine IR test had a sensitivity of 95.5%, a specificity of 97.1%, a positive predictive value of 72.4%, and a negative predictive value of 99.6% for the diagnosis of grade III PCL injuries. Posterolateral corner injury had a significant interaction with the supine IR test, increasing its sensitivity and decreasing its specificity. CONCLUSION: PCL-deficient knees demonstrated an increase in the side-to-side difference in tibial internal rotation compared with other knee pathologies. The supine IR test offers high sensitivity and specificity for grade III PCL injuries and may represent a useful adjunct for diagnosing PCL injuries.

Posterior lateral meniscal root tear due to a malpositioned double-bundle anterior cruciate ligament reconstruction tibial tunnel.

UNLABELLED: The posterior lateral (PL) meniscal root plays an essential role in ensuring the health of the articular cartilage of the knee joint. Injuring the PL meniscal root has been demonstrated to result in significant deleterious changes to tibiofemoral contact mechanics. Anatomic studies have reported that the posterolateral bundle of the anterior cruciate ligament (ACL) and PL root lie in close proximity on the tibial plateau. Therefore, during a double-bundle ACL reconstruction, the PL root may be inadvertently injured during the reaming of the posterior ACL double-bundle reconstruction tibial tunnel that is intended to recreate the posterolateral bundle of the ACL. This case report describes an occurrence of iatrogenic injury to the PL root due to a posteriorly malpositioned double-bundle ACL tibial tunnel. This report is the first known description of this mechanism of injury in the literature. LEVEL OF EVIDENCE: Case report, Level IV.

Meniscal root tears: a classification system based on tear morphology.

BACKGROUND: Meniscal root tears present in many forms and can have profound consequences on the health of knee articular cartilage. While the biomechanics, natural history, and treatment of root tears have been increasingly investigated, the spectrum of meniscal root tear patterns observed during arthroscopic examination has yet to be defined and categorized. PURPOSE: To establish a classification system for meniscal root tears by reporting the morphology of meniscal root tears from a consecutive series of arthroscopic surgeries. It was hypothesized that meniscal root tears could be grouped into types by distinct tear patterns and that recognition of tear pattern would affect treatment choice. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: All patients who underwent arthroscopic surgery from April 2010 to May 2014 by a single orthopaedic surgeon were included. After arthroscopic examination, data regarding the integrity of the meniscal roots were prospectively recorded in a data registry. Tear morphology and treatment received were subsequently extracted by 2 independent reviewers from operative notes and arthroscopic surgical photos. RESULTS: A total of 71 meniscal root tears in 67 patients were grouped into tear types with similar tear morphologies. Meniscal root tear patterns were categorized into partial stable root tears (type 1; n = 5); complete radial tears within 9 mm of the bony root attachment (type 2; n = 48), further subclassified into types 2A, 2B, and 2C, located 0 to <3 mm, 3 to <6 mm, and 6 to 9 mm from the root attachment, respectively; bucket-handle tears with a complete root detachment (type 3; n = 4); complex oblique tears with complete root detachments extending into the root attachment (type 4; n = 7); and bony avulsion fractures of the root attachments (type 5; n = 7). CONCLUSION: This study demonstrated that it was possible to establish a concise classification system to group patients with meniscal root tears by tear morphology. Treatments received varied across tear types.

Trochlear dysplasia and the role of trochleoplasty.

The diagnosis and treatment of chronic patellar instability caused by trochlear dysplasia can be challenging. A dysplastic trochlea leads to biomechanical and kinematic changes that often require surgical correction when symptomatic. In the past, trochlear dysplasia was classified using the 4-part Dejour classification system. More recently, new classification systems have been proposed. Future studies are needed to investigate long-term outcomes after trochleoplasty.