The two most common techniques to determine femoral tunnel placement during medial patellofemoral ligament (MPFL) reconstruction are radiographic and by palpation. Their intra/interobserver reliability is widely debated. Both techniques rely on identifying bony landmarks such as the medial epicondyle (ME) and adductor tubercle (AT) during surgery. During MPFL reconstructive surgery, the central longitudinal vessels (CLVs) are seen consistently. The aim of this study was to investigate the anatomic relationship of CLV to ME and AT and to determine if CLV might be used as a landmark during MPFL reconstruction. A retrospective review of MRI scans in skeletally mature patients was undertake. There were two groups, a PFI group that consisted of patients with a diagnosis of patellofemoral instabiliy (PFI) and a non-PFI group that underwent MRI scan for an alternative diagnosis. MRIs were measured for the CLV-ME-AT anatomy and relationship. Following exclusions, 50 patients were identified in each group. The CLV passed anterior to the AT and ME in all patients. ME morphology did not differ greatly between the groups except in the tubercle height, where there was statistically significant but not a clinically important difference (larger in the non-PFI group, 2.95 vs. 2.52 mm, p = 0.002). The CLV to ME tip distance was consistent between the groups (PFI group 3.8 mm and non-PFI group 3.9 mm). The CLV-ME-AT relationship remained consistent irrespective of patients\' presenting pathology. The CLV consistently courses anterior to ME and AT. The CLV could be used as a vascular landmark assisting femoral tunnel placement during MPFL reconstruction.

The femoral epicondyle is an anatomical bony landmark essential for surgeons and anatomists, but there are discrepancies between the two fields when using this term. In current orthopedic surgery, it commonly denotes the small bony prominence of the femoral condyle. Given the derivation, \"epicondyle\" should be a region projecting laterally from the articular surface rather than a point. These discrepancies in usage are found not only between the fields but also in the literature. This article reviews the narrative definition of \"epicondyle of the femur\" in surgery and the evolution of the term in anatomy. The outcomes of the review suggest a relationship between the differing perceptions of the epicondyle and the evolution of the term. In reports of studies related to the epicondyle, it is strongly recommended that the definition of the word is clearly stated, with an understanding of its evolution.

The adductor tubercle of the distal femur is utilized by surgeons as an anatomic landmark to identify graft anchor placement during medial patellofemoral ligament (MPFL) and medial quadriceps tendon femoral ligament (MQTFL) reconstruction for patellofemoral instability. In the skeletally immature population, its location relative to the physis has not been well defined.
To identify the location of the adductor tubercle relative to the distal femoral physis in skeletally immature individuals and gain insight regarding optimal graft anchor placement for pediatric patients undergoing MPFL and MQTFL reconstruction.
Descriptive laboratory study.
Thin-cut computed tomography scans of 37 male cadaveric specimens (age, 4-16 years) were obtained from the New Mexico Decedent Image Database. A measurement protocol to identify the adductor tubercle was created with guidance from a fellowship-trained musculoskeletal radiologist. By utilizing axial, coronal, and sagittal views of knee computed tomography scans, the adductor magnus tendon was identified and followed distally to its insertion (adductor tubercle) on the distal femur. Distance from the midpoint of the adductor magnus tendon insertion relative to the physis in the proximal-distal orientation was measured. The anterior-posterior distance of the midpoint tendon insertion relative to the posterior femoral cortex line was also evaluated.
The midpoint of the adductor magnus tendon was at the physis in 30 specimens. One 8-year-old cadaveric specimen had an insertion 1.1 mm distal to the physis. In all specimens ≥15 years old (n = 6), the adductor magnus tendon insertion was distal to the physis with a mean distance of 2.73 mm. The location of the adductor tubercle was always posterior (mean, 5.1 mm) with respect to the posterior femoral cortex line.
The location of the adductor tubercle in male pediatric patients is likely at or distal to the physis. Thus, the findings of this study directly conflict with previous studies that suggested a more proximal location.
Optimal graft anchor placement during MPFL and MQTFL reconstruction in the skeletally immature patient can be challenging because of the variability reported in previous studies of the medial patellofemoral complex origin relative to the physis. This study suggests that distal-rather than proximal-graft anchor placement might better help restore patellofemoral isometry.

OBJECTIVE: This study aimed to investigate the bony surface characteristic of the femoral attachment of the medial patellofemoral ligament (MPFL) and the correlation between the relevant layered structures, including muscular aponeurosis and the joint capsule, which contribute to patellofemoral joint (PFJ) stability.
METHODS: The morphology of the medial aspect of the medial condyle using micro-computed tomography and analysed cortical bone thickening in 24 knees was observed. For the macroscopic and histological analyses, 21 and 3 knees were allocated, respectively. The Kruskal-Wallis one-way analysis of variance test with Dunn post hoc testing was performed for statistical analysis.
RESULTS: At the level of the adductor tubercle, there were no significant differences in cortical bone thickness. At the level of the medial epicondyle (MEC), cortical bone thickness was considerably greater than that in other areas of the medial condyle (mean ± standard deviation, 0.60 ± 0.20 mm; p < 0.0001). Macroscopic analysis revealed that the deep aponeurosis of the vastus medialis obliquus and the tendinous arch of the vastus intermedius distally formed the composite membrane and adjoined to the joint capsule to firmly attach to MEC, which was located at 41.3 ± 5.7 mm posterior and 14.2 ± 3.1 mm superior to the joint cartilage. Histological analysis showed a composite membrane and adjoining capsule attached to MEC via fibrocartilage.
CONCLUSIONS: MPFL could be interpreted as part of the deep aponeurosis of the vastus medialis obliquus (VMO) and the tendinous arch of the vastus intermedius, which combined with the joint capsule to attach to MEC. The cortical bone thickening indicated that the tensile stresses were loaded on MEC in aged cadavers. Involvement of VMO and vastus intermedius aponeuroses in restored graft of MPFL could utilise the dynamic stability of surrounding muscles to mimic a native structure.

BACKGROUND: In this study, the traditional \"Anatomical Landmark-Distance Method (AL-DM)\" in the formation of joint line (JL) was compared with \"Adductor Tubercle-Ratios method\" (AT-RM), and the effect of reestablishment of JL on clinical and functional outcomes were evaluated.
METHODS: 16 revision total knee arthroplasties (rTKAs) were performed by using \"AT-RM\" (group 1) and 16 rTKA by using \"AL-DM\" (group 2) in our clinic between 2015 and 2018. The data were prospectively collected and a total of 32 knees of 31 patients were analyzed. At the final follow-up, knee functions were evaluated by using Knee Society Score (KSS) knee and function, Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores, Short Form-36 (SF-36) questionnaires and physical examinations.
RESULTS: Postoperative flexion arc was higher in Group 1. KSS knee and function scores were better in group 1. In group1, JL was reestablished successfully in all revision rTKAs in terms of ATJL and the tibial tubercle TT-JL ratios. The improvement in KSS knee and function scores and WOMAC scores were also better in group 1. Measurements showed that the improvement in KSS scores increased as AT-JL and TT-JL distances approached the calculated values.
CONCLUSIONS: \"AT-RM\" was shown to be superior to the traditional distance method in terms of JL reestablishment. Functional results and patient satisfaction increased when JL was reestablished.

Medial patellofemoral ligament (MPFL) reconstruction is one of the main treatments for lateral patellar translation. Based on intraoperative true lateral radiographs, the accepted methods for femoral MPFL tunnel location are potentially inaccurate. Direct assessment of anatomic characteristics during surgery through palpation of the anatomic landmarks involving the saddle sulcus might help eliminate tunnel malposition.
The saddle sulcus is a reliable osseous landmark where the MPFL attaches for tunnel placement.
Descriptive laboratory study.
A total of 9 fresh-frozen unpaired human cadaveric knees were dissected; MPFL insertion point and relative osseous structures were marked. Three-dimensional images and transformed true lateral radiographs were obtained for analysis; 3 previously reported radiographic reference points for MPFL femoral tunnel placement were determined on all images and compared with the anatomic insertion.
A saddle sulcus consistently existed where the MPFL was attached, located at 11.7 ± 5.9 mm from the apex of the adductor tubercle (AT) to the medial epicondyle (ME), 62.8% of the average distance between the apexes of the AT and ME, and 5.6 ± 2.8 mm perpendicular-posterior to the border connecting the AT and ME. The reported radiographic reference points were located at average distances of 6.2 ± 3.2 mm (Schöttle method), 5.9 ± 2.3 mm (Redfern method), and 7.3 ± 6.6 mm (Fujino method) from the saddle sulcus center on the true lateral radiographs.
The saddle sulcus was a reliable landmark where the MPFL was anatomically attached, located approximately 12 mm from the AT to the ME (approximately 60% along a line from the AT to the ME) and 6 mm perpendicular-posterior to the border connecting the apexes of the AT and ME. Additionally, the saddle sulcus position presented variability on the femoral aspect of different knees. All of the average direct distances from the sulcus to the reference radiographic points exceeded 5 mm, and tunnel localizations on a true lateral radiograph were inaccurate.
This study demonstrates the potential precise position of the saddle sulcus, according to the ME and AT, as a reliable anatomic landmark for MPFL femoral tunnel location. Radiographic reference points were not accurate during MPFL reconstruction. Direct palpation of the landmarks might be effective for femoral MPFL tunnel placement.

BACKGROUND: The adductor tubercle (AT) has been used intraoperatively as a landmark to evaluate the joint line position in knee arthroplasty. The purpose of this study was to determine whether the AT could be clearly identified on radiographic imaging as well as if the AT to joint line distance could be accurately measured for use as a radiographic landmark.
METHODS: The distance from the AT to the joint line was measured on each of 78 knees during total knee arthroplasty. Next, the AT was marked with a metal marker for radiographic analysis. On the postoperative radiograph, the location of the AT was determined by tracing the metal marker. Subsequently, the radiographic joint line distance (RJLD) was measured and compared with the intraoperative joint line distance (IJLD) to test the agreement of the measurements.
RESULTS: Location analysis indicated that the inflection point on the radiographic contour of the distal femur was the predicted location for the AT. The mean IJLD was 45 ± 3 mm and the RJLD was 45 ± 4 mm. The intraclass correlation coefficient was used to evaluate the inter-rater reliability between the two methods; that coefficient was 0.751, indicating good agreement between them. Measurements on the radiograph were comparable to the intraoperative measurements of the operated knees.
CONCLUSIONS: In addition to being an intraoperative landmark, the AT may also be an eligible radiographic landmark for analyzing joint line level. The RJLD measurement may be obtained to plan the joint line position in knees with significant bone loss preoperatively and to follow up the results of surgery postoperatively.

暂无摘要。

Restoring the joint line (JL) is a key element of performing joint arthroplasty, which is a challenging proposition during revision surgeries. We investigated the accuracy of 2 different methods of identifying the JL using the adductor tubercle (AT) as the reference landmark.
Standardized protocols for measurements from 50 knee radiographs were established. Femoral width (FW) and the distance from the AT to the JL (ATJL) were measured on anteroposterior radiographs, and the femoral diameter (FD) was measured on true lateral views. The individual ratio of FW and FD to ATJL was calculated using linear regression analysis. Intraobserver and interobserver reliability was assessed. In order to test the accuracy of the ratio calculated, we also recorded the FW and ATJL of 20 additional knees by magnetic resonance images.
There are significant differences between genders with these parameters. A linear correlation was found between FW and ATJL (r2 = 0.7201), which was more reliable than the correlation between FD and ATJL (r2 = 0.3918). Interobserver repeatability was better for ATJL and FW than for FD. The mean ratio of ATJL/FW was 0.560 ± 0.03, and there was no statistical difference between men and women. After using this ratio formulas in those data measured from knee magnetic resonance imaging, all cases revealed reliability with 100% cases lying in a 4-mm error margin.
The AT can be used as a reliable landmark to determine the knee JL position, and the formulas for calculating the ATJL with FW can be applied, making intraoperative identification and judgment easier.

BACKGROUND: If the adductor tubercle could be accurately located, it would be a useful landmark for identifying the joint line during knee arthroplasty. This study aimed to develop an intraoperative technique to improve its locating accuracy.
METHODS: Evaluation of bone specimens and cadaveric knees revealed that the proximal slope of the adductor tubercle (PSAT) turns from the medial surface vertically into the superior surface of the medial condyle, which forms a distinctive edge. This provided an ideal landmark that could be unambiguously engaged using a tipped instrument. Using the PSAT as a reference point, we measured the distance to the joint line (the proximal-distal condylar length; PDCL) in eight pairs of cadaveric knees, and evaluated the inter-observer variability. Next, we measured 120 knees undergoing total knee arthroplasty to test this technique in a normal population. Finally, we divided each PDCL by the respective anterior-posterior condylar length (APCL) to create a ratio that could predict the PDCL regardless of knee size.
RESULTS: The intra-class correlation coefficient (ICC) was 0.86 for the cadaveric measurements. The mean PDCL from the operated knees was 46mm (coefficient of variance (CV): eight percent). The mean PDCL/APCL ratio was 0.77 (CV: six percent). The high ICC and low CV indicated that using the PSAT was a reliable technique.
CONCLUSIONS: The PSAT is an ideal surgical landmark. The tipped instrument engagement technique with it may help to unambiguously locate the adductor tubercle in order to identify the joint line during knee arthroplasty.