True Lateral Radiographs Research Articles

Comparison of Cephalometric Norms of Pleasing Faces with Patients Reported in the Out Patients Department of Orthodontic at Liaquat University of Medical and Health Sciences Hyderabad/ Jamshoro

Abstract: Objective: This was a cross sectional study aimed to analyze Cephalometric norms of patients reporting to outpatients department of Orthodontic Department Liaquat University of Medical and health sciences, Hyderabad / Jamshoro in comparison with the Caucasian norms. Methods: The study was carried out on true lateral cephalometric radiographs of 150 subjects (75 male, 75 female) between 18-28 years, with esthetically pleasing and harmonious faces, competent lips, class 1 molar relationship, with all permanent teeth present, no facial trauma and no history of previous orthodontic treatment. The mean, standard deviation and ranges of all measurements were compared with the norms established by Steiner. For all statistical evaluation was performed by SPSS 16 .0 version software, the student t-test were performed to compare the sample with Steiner means. Results: several significant findings were notable in the result of the present study. The result of the present study sample showed retrusive mandible (p < 0.000), horizontal growth pattern, procline upper incisors (p < 0.000), decrease inter-incisal angle (p < 0.001) when compared with the Caucasian norms taken by Steiner. No significant findings were found between male and female in present study sample. Conclusion: There were no significant differences between the male and female Population cephalometric norms Even though, a careful analysis of cephalom norms of patients along with other diagnostic considerations before initiating orthodontic treatment for better stability. Keywords: Cepahlomatric norms, Steiner analysis

Three-Dimensional Computed Tomography Assessment and Planning for Severe Lower Limb Deformities: A Case Report of Bilateral Fibular Hemimelia

To correct a lower limb deformity, orthopedic surgeons must have an exact understanding of the deformity. In general, preoperative planning is carried out using anterior-posterior (AP) and lateral radiographs. However, for severe cases with a combination of angular and rotational deformities of the lower limb, obtaining true AP and lateral radiographs is difficult and accurate calculation of the rotational deformity from radiographs is impossible. In this report, we propose to focus on preoperative assessment using three-dimensional (3D) reconstruction images of computed tomography (CT) scans for severe lower limb deformity in a patient with bilateral fibular hemimelia type II according to the Achterman- Kalamchi classification. She underwent bifocal deformity corrections of the bilateral tibiae using Taylor spatial frames in combination with the Ilizarov external fixator. Complete bony union was achieved, without angular deformity or limb length discrepancy.

Beta Angle in a Sample of Iraqi Adults with Class I Skeletal and Dental Relations and Its Correlation with Other Craniofacial Measurements

This study aimed to determine the value of Beta angle for a sample of Iraqi adults with class I skeletal and dental relations and to verify the existence of sexual dimorphism and to find out the relation between this angle and other craniofacial measurements. Materials and Methods: Sixty dental students (23 males and 37 females) with an age ranged between 20-31 years old and having class I skeletal and dental relations were chosen for this study. Each student was subjected to clinical examination and digital true lateral cephalometric radiograph. The radiographs were analyzed using AutoCAD 2007 computer program to measure the angular and linear variables. Descriptive statistics were obtained for the measurements for both genders and total sample; independent samples t-test was performed to evaluate the gender difference and Pearson's correlation coefficient test used to detect the relation between the Beta angle and other measurements. Results and Conclusions: The value of Beta angle in this study was 32.63°± 2.57°. When the Beta angle is less than 27°, the case is class II and when it is more than 38°, the case is class III. There is no genders difference regarding the Beta angle and this angle correlated significantly and positively with the mandibular length and articular angle and negatively with ANB and saddle angles.

Does flexion of the femoral implant in total knee arthroplasty increase knee flexion: A randomised controlled trial

IntroductionProsthetic and operative modifications in total knee arthroplasty (TKA) have been proposed to maximise post-operative knee flexion as it is essential in routine functional activities. MethodsWe performed a double blind randomised controlled trial to compare clinical outcomes of primary cruciate-retaining TKA for osteoarthritis with the femoral component implanted in either 4° flexion in the sagittal plane (F) or in a neutral position (C). The primary outcome of knee flexion and secondary outcomes knee extension, quadriceps strength, WOMAC, SF-12v2, timed stand test, stair climb test and satisfaction were assessed at 1year. Knee flexion and extension were also assessed intra-operatively. Implant flexion was measured from true lateral radiographs. ResultsThirty-nine participants (40 knees) were recruited, 20 knees per group. Three subjects from the control group and two from the flexed group were lost to 1year follow-up but numbers were sufficient to satisfy the sample size calculation. Significant differences were found between the groups in knee flexion (F: 113.6±8.8° pre-operative, 122.4±6.0° intra-operative, 110.2±7.5° 1year, C: 117.4±11.7°, 117.4±7.6°, 103.5±10.7°. p=0.031) and mental component score of the SF12-v2 (F 53.3±13.2, C 61.1±7.3, p=0.009) but there were no significant differences in other outcomes and patients were equally satisfied. ConclusionFlexing the femoral implant in this cruciate retaining TKA system provided a significant difference in knee flexion compared to a neutral position. The improvement appears to occur predominantly at surgery and was not associated with a clinical or functional benefit at 1year. (ACTRN12606000325505). Level of evidence: Level 1; randomised controlled trial.

Measured Flexion Following Total Knee Arthroplasty

Postoperative flexion is an important factor in the outcome of total knee arthroplasty. Although normal activities of daily living require a minimum of 105° to 110° of flexion, patients from non-Western cultures often engage in activities such as kneeling and squatting that require higher flexion. The desire to achieve greater flexion serves as the driving force for prosthetic modifications, including high-flexion designs. Techniques used to measure knee flexion and knee position during measurement are not often described or are different depending on the examiner. The purpose of this study was to compare active (self) and passive (assisted) flexion after successful total knee arthroplasty for 5 prostheses (2 standard and 3 high-flexion) using clinical (goniometer) and radiographic (true lateral radiograph) measurement techniques by different independent examiners.At a mean follow-up of 2.7 years (range, 1-5.6 years), a total of 108 patients (144 total knee arthroplasties) had completed the study. Mean postoperative active flexion was 111° clinically and 109° radiographically for the standard designs and 114° clinically and 117° radiographically for the high-flexion designs. Adding passive flexion increased flexion to 115° clinically and 117° radiographically for the standard designs and 119° clinically and 124° radiographically for the high-flexion designs. Flexion differences between the 2 measurement techniques (active vs passive and clinically vs radiographically) were statistically significant (P<.05). These findings demonstrate the importance of describing how flexion is measured in studies and understanding how the method of measurement can affect the findings.

Paper 116: Quantitative Analysis of Lateral Intercondylar Ridge Using Transparent 3D-CT

IntroductionLateral intercondyler ridge has been attracting attention as the osseous landmarks of the femoral attachment of the anterior cruciate ligament (hereafter referred to as ACL). Several studies have focused on the three dimensional (3D) imaging of this bony eminence. We have reported the value of transparent 3D computed tomography (T-3DCT) and true lateral radiograph of the knee, with due consideration to the rotational condition of the femur. The purpose of this study is to quantitatively analyze the configuration and location of the ridge using T-3DCT images.

In-hospital postoperative radiographs for instrumented single-level degenerative spinal fusions: utility after intraoperative fluoroscopy

There is a paucity of literature examining the clinical yield of in-hospital postoperative radiographs for patients who have had instrumented single-level spinal fusions with intraoperative fluoroscopic guidance. Many spinal surgeons consider postoperative standing radiographs to be the appropriate standard of care, even in patients who have an uneventful postoperative course. To evaluate the additional clinical yield and cost-effectiveness of in-hospital postoperative standing radiographs for patients undergoing instrumented single-level cervical and lumbar fusions in which intraoperative fluoroscopy is used. Are postoperative standing radiographs necessary before hospital discharge? Retrospective review of 100 consecutive degenerative spinal surgical cases in which intraoperative fluoroscopic imaging was compared with immediate postoperative radiographs using a vertebral grid mapping technique. A retrospective review of 100 consecutive patients who had an instrumented single-level cervical (30) or lumbar (70) fusion for a degenerative spinal condition performed by the same surgeon using intraoperative fluoroscopy. All patients had a documented uneventful postoperative hospitalization without evidence of new postoperative neurologic finding. All patients had both anteroposterior (AP) and lateral intraoperative fluoroscopic images and same-hospitalization standing AP and lateral radiographic images, which were performed within 72 hours postoperatively. Intraoperative and postoperative images were compared by two observers independently using a vertebral grid mapping technique to locate screw position and control magnification differences. Study parameters included screw tip position grids, interbody graft position, segmental sagittal plane alignment, spondylolisthesis grade, and hospital charges for patient imaging and interpretation. Early instrumentation failure and/or screw position change was not observed in any patient. Seventy-four patients demonstrated a grid match for all screw tip positions on both true AP and lateral radiographs. Twenty-six patients had either a postoperative AP or lateral radiograph that was clinically malrotated and precluded comparison with the intraoperative true fluoroscopic images. Segmental sagittal alignment difference between intraoperative fluoroscopic and postoperative radiographic sagittal images averaged only 1.2° (range, 0-9) and was not statistically significant (paired Student t test, p=.88). Significant difference between intraoperative and immediate postoperative interbody graft position and spondylolisthesis grade was not demonstrated in any patient. Patient hospital billing charges for postoperative AP and lateral radiographic imaging with interpretation averaged $600. In patients who have a single-level instrumented fusion and a documented uneventful postoperative course, in-hospital postoperative standing AP and lateral radiographs do not appear to provide additional clinically relevant information when intraoperative fluoroscopy is properly used. Fluoroscopy also demonstrated more consistent accuracy and a potential for significant cost savings.

Fractures in Brief: Olecranon Fractures

Olecranon fractures are relatively common injuries, accounting for approximately 10% of upper extremity fractures in adults [26]. These fractures may result from a direct blow to the proximal ulna, or indirectly, via the forceful contraction of the triceps against resistance (typically, during a fall onto an outstretched hand). Less commonly, the olecranon may fracture when the elbow is hyperextended, as the bone is impacted against the olecranon fossa of the distal humerus. For unstable injuries, operative fixation typically is required. Even after recovery, loss of ROM is not uncommon. This article provides an overview of olecranon fractures in adults; therefore, discussion of olecranon fractures in skeletally immature patients is beyond the scope of this article.

The Posterior Condylar Offset Ratio

IntroductionPosterior Condylar Offset is an area of interest in knee arthroplasty research and clinical outcome. The aim of the study is to define a quantifiable Posterior Condylar Offset Ratio, a normal value for this ratio and to confirm its reproducibility on pre-operative radiographs. MethodWe propose a new Posterior Condylar Offset Ratio which is defined as the maximal thickness of the posterior condyle projecting posteriorly to a straight line drawn as the extension of the posterior femoral shaft cortex, divided by the maximal thickness of the posterior condyle projecting posterior to a straight line drawn as the extension of the anterior femoral shaft cortex on a true lateral radiograph of the distal quarter of the femur. We have measured this on 100 true lateral radiographs (50 females, 50 males, and mean age 65years). ResultsThe mean ratio was 0.44 (SD 0.02) and was shown to have good reproducibility (intra-observer error 0.899 and inter-observer error 0.882. The ratio was also very consistent between male and female patients (0.44 (SD 0.02) for the males and 0.45 (SD 0.02) for the females). Adjusting the ratio for reported posterior condyle articular cartilage thickness increased the ratio to 0.47 (SD 0.02). ConclusionWe suggest our Posterior Condylar Offset Ratio is a useful tool to aid further research in this area of knee arthroplasty and propose a normal value of 0.44 on radiographs and 0.47 on post-operative knee arthroplasty radiographs.

The reliability of AutoCAD program in cephalometric analysis in comparison with pre- programmed cephalometric analysis software

Background: This study aimed to evaluate the reliability of AutoCAD program in cephalometric analysis in comparison with View - box 3.1.1 cephalometric computer software. Materials and method: The sample consisted of 30 digital true lateral cephalometric radiographs of some under- and postgradu - ate students in the College of Dentistry/ University of Baghdad. Seventeen parameters (11 angular and 6 linear) were measured using the Viewbox 3.1.1 cephalometric computer software and re-measured using AutoCAD program. Descriptive statistics were performed for each parameter and paired samples t-test was obtained to evaluate the difference between both of the methods. Results: The results revealed the presence of non-significant difference between both softwares. Conclusions: Cephalometric analysis with AutoCAD program was comparable with Viewbox 3.1.1 software and both of them de - pend on the landmarks identification by the observer. AutoCAD software is available in Iraq unlike the other softwares and it can be used in clinical diagnosis also suited for research projects.

Radiographic landmarks for tunnel placement in reconstruction of the medial patellofemoral ligament

To verify the findings of previous studies in confirming radiographic landmarks for the femoral attachment of the medial patellofemoral ligament (MPFL), but also to define radiographic landmarks for the patellar attachment. Assess the effect of limb rotation upon these radiographic landmarks. The medial patellofemoral ligament was identified in ten fresh-frozen human cadaveric knees. A headed pin was used to mark the centre of the femoral and patellar attachments. True lateral radiographs were performed followed by lateral radiographs in 10° and 20° of internal and external rotation. Posterior-anterior and proximal-distal position of the headed pin was evaluated. The femoral attachment averaged 3.8 ± 5.0 mm anterior to the posterior femoral cortical line and 0.9 ± 2.4 mm distal to the perpendicular line intersecting the posterior aspect of Blumensaat's line. The patellar attachment averaged 7.4 ± 3.5 mm anterior to the posterior patellar cortical line, 5.4 ± 2.6 mm distal to the perpendicular line intersecting the proximal margin of the patellar articular surface. There was a significant relationship between limb rotation and distance of femoral and patellar attachment from the posterior cortical line (P < 0.0001 and P < 0.0002 respectively). Radiographic landmarks for the femoral attachment of the MPFL identified in this study are comparable with other recent work. This study describes new radiographic landmarks for the patellar attachment of the MPFL and highlights that it is essential to acquire true lateral radiographs if these radiographic landmarks are to be interpreted accurately.

Factors Affecting Assessment of Ulnar Bowing in Radiography

The "ulnar bow sign" is a novel marker of plastic ulnar deformity with radial head dislocation. This sign is best assessed on true lateral radiographs. However, such radiographs are rarely obtained in routine clinical situations. Misdiagnosis can result from using suboptimum radiographs. The present study examined the clinical radiographs of normal forearms in children to identify factors that affect the assessment of ulnar bowing. We retrospectively analyzed the lateral forearm radiographs of 175 normal children ranging in age from 2 to 12 years. Radiographs were classified according to humeral position. The size and direction of the maximum ulnar bow were evaluated. The effect of humeral position, age, sex, and arm side on ulnar bow assessment were analyzed. Of the 175 radiographs, 27 showed a concave dorsal ulnar border (15.4%), 90 showed a straight dorsal ulnar border (51.4%), and 58 showed a convex dorsal ulnar border (33.2%). Only 22 (12.6%) radiographs were found to be true lateral radiographs; the remainder showed evidence of humeral rotation and/or tilting. Humeral tilting was found to affect the assessment of ulnar bowing (P<0.05), whereas the other measured factors did not. The present study found that humeral tilting at the time of forearm radiography affected the assessment of ulnar bowing. Therefore, physicians should be cautious when assessing ulnar bow in the clinical setting. Level IV.

The prediction of the relation between anterior facial skeleton and sella turcica in Iraqi sample

Background: The relation between the anterior facial skeleton and sella turcica may vary from individual to individual, and the establishment of normal standards in different skeletal patterns will aid in the process of eliminating any abnormality in such an important region. This study aimed to find the relation of the anterior facial skeleton to the sella turcica in different skeletal patterns and in both gender and also to find the most valid equation for describing these relationships to be applied practically in different skeletal patterns. Materials and method: The sample consisted of “138” digital true lateral cephalometric radiographs related mostly to patients attended to the college of dentistry /Baghdad University with an age range “18-30” years, they classified into three skeletal patterns . Six cephalometric parameters in addition to shape of Sella Turcica were measured and assessed for each individual radiograph using AutoCAD program 2008. Results : The linear measurements that assess the relation of sella turcica to anterior facial skeleton in all skeletal patterns showed a very highly significant gender differences; being larger in males than in females, while for the angular measurements, no gender difference were found. Among the three skeletal patterns only the “S-B Length” and the “ASB angle” showed a very highly significant difference. The Pearson’s correlation test in all skeletal patterns showed a very highly significant positive correlation among “ S-N, S-A & S-B Length ” and among “ NSA, NSB & ASB angles”, however highly predictable regression equations in the three skeletal patterns were found for the first time in Iraq between “ NSB & NSA angles ”. Conclusions: The introduction of valid predictable equations for the first time that can assess the relation between Sella Turcica and anterior facial skeleton in Iraqi sample.

Evaluation of Popliteal Artery Injury Risk With Locked Lateral Plating of the Tibial Plateau

This study was undertaken to determine if there is increased likelihood of popliteal artery injury as one places a fixed-angle lateral proximal tibia locking plate with posterior plate lift off and or anterior plate translation from the ideal position. A Synthes (Synthes USA, West Chester, PA) 3.5-mm and 4.5-mm lateral proximal tibia locking plate was placed consecutively on each of six specimens in the straight lateral (SL) position. Screw position with respect to the medial cortex was recorded as well as the distance of the posterior most screw tip to the popliteal artery. Next a 3-mm shim was placed under the posterior edge of the same plate to mimic posterior plate lift off (LO) followed by placement of a 6-mm shim. The same experiment was repeated with the plate translated 5 mm anteriorly (AT). The popliteal artery was injured in zero of six specimens using the 3.5-mm plate. The popliteal artery was injured in six of six specimens using the 4.5-mm plate in the 5-mm AT 6-mm LO position, five of six with 5-mm AT and 3-mm LO, two of six with only 5-mm AT, four of six with SL and 6-mm LO, two of six with SL and 3-mm LO, and zero of six with SL. The Synthes 4.5-mm plate can put the popliteal artery at risk with as little as 3-mm posterior liftoff in the intended straight lateral position or with 5-mm anterior plate translation with no posterior liftoff. Therefore, placement of the 4.5-mm plate in the proper position and confirmation of its position with a true lateral radiograph is paramount to avoid injury to the popliteal artery.

Radiological criteria for trochlear dysplasia in children and adolescents

Trochlear dysplasia is a well-known cause for recurrent patellar instability. Besides clinical findings, the treatment is based on radiological diagnostic tools. In adults the characteristics of trochlear dysplasia are determined by magnetic resonance imaging (MRI) scans as well as on true lateral radiographs. For children there are no established criteria for the radiological diagnosis of trochlear dysplasia. This study was designed to evaluate if typical radiological findings of trochlear dysplasia on lateral radiographs in adults are also found in children and adolescents with open growth plates. We analyzed true lateral radiographs of children and adolescents with MRI-detected trochlear dysplasia. On lateral radiographs three factors were relevant: crossing sign (deepest part of the trochlea crosses the most anterior point of the lateral condyle), a supratrochlear spur or bump (bulge of the proximal trochlea), and a double contour (due to a hypoplastic medial condyle). In all patients with trochlear dysplasia at least one typical radiological finding usually found in adults could be documented. Only true lateral radiographs allow the diagnosis of trochlear dysplasia in children and adolescents with open physis to be made. MRI scans on a regular basis are, therefore, not mandatory although they are the diagnostic golden standard for the diagnosis of trochlear dysplasia.

A More Reliable Method to Assess Acetabular Component Position

Acetabular component position is associated with joint function and bearing wear. Current techniques for determining acetabular component version on standard radiographs lack reliability. Other, more consistent techniques are time-consuming and require additional equipment or software. We compared three methods of acetabular component position assessment: (1) Einzel-Bild-Roentgen-Analyse (EBRA), (2) Woo and Morrey, and (3) the new ischiolateral method. We assessed axial component position for 52 hips, with at least three radiographic series, using EBRA, and on true lateral radiographs using the Woo and Morrey method and a new method that uses the ischium as a skeletal landmark, the ischiolateral method. The mean SDs of the ischiolateral (2.15°) and EBRA (2.06°) methods were lower than that of the Woo and Morrey method (3.65°) but were not different from one another. We observed a SD of greater than 4° in 19 (36.5%) hip series using the Woo and Morrey method, compared to six series (11.5%) for both the ischiolateral and EBRA methods. Twenty-four (12.6%) Woo and Morrey measurements were greater than 4° from the mean for the hip series, compared to seven (3.8%) for ischiolateral and nine (4.7%) for EBRA. The intraclass correlation coefficients for intra- and interobserver reliability for the ischiolateral method and EBRA were the same (0.9). Referencing the ischium standardizes pelvic position on each lateral radiograph and provides a simple and reliable means to assess axial component position, which is a surrogate for the planar anteversion measured by EBRA.

Nose and skeletal patterns, is there a relationship?

Background: This study aimed to evaluate the relationship between the nasal length and projection with the sagittal and vertical jaw parameters. Material and method: One hundred digital true lateral cephalometric radiographs were selected from the files of the patients attending the orthodontic clinic in the College of Dentistry at Baghdad University and classified according to the ANB angle into class I and class II (50 cases for each group). Eleven skeletal and 2 nasal soft tissue parameters were measured using AutoCAD program. Independent samples t-test was used to evaluate the genders and classes differences and Pearson coefficient of correlation was used to show the relationship between the nasal and skeletal parameters. Results: The results indicated that the males had longer and prominent noses in both classes. On the other hand, there was non-significant correlation between the sagittal relation and the nasal parameters, while there was significant correlation between the facial heights and nasal parameters. Conclusion: The noses in males were longer and more prominent than females. The sagittal relation parameters had no influence on the nasal parameters in contrary to the facial heights. Key words: Nasal length, projection, skeletal relations

The relation of the distal femoral physis and the medial patellofemoral ligament

The purpose of this study was to analyse true lateral radiographs of children and adolescents to determine the relation of the origin of the MPFL and the distal femoral physis considering the complex anatomy of the physis. The hypothesis was that the femoral insertion of the MPFL is distal to the growth plate. Antero-posterior and true lateral radiographs from PACS computer records of 27 patients with a history of patellofemoral instability were assessed. To determine the femoral origin of the MPFL, the method by Schöttle et al. and the method by Redfern et al. were applied independently. On the anteroposterior radiograph, the distance between the medial most part of the physis and the central part of the physis was measured to quantify the concave curvature of the physis. To cross-reference the femoral insertion of the MPFL onto an ap view, the projected MPFL origin-physis distance was subtracted from the distance between the most medial part of the physis and the central part of the physis. The projected median origin of the MPFL as measured on a lateral radiograph was located 3.2 mm (1.2-5.8 mm) proximal to the physis. The median distance between the most medial part of the physis and the physeal line on the anteroposterior radiograph was 9.9 mm (4.1-12.0 mm). Subtracting the two measured values, the median origin of the MPFL as seen on the ap view was 6.4 mm (2.9-8.5 mm) distal to the femoral physis. Considering the concave curvature of the distal femoral physis, it can be assumed that the femoral insertion of the MPFL is distal to the femoral physis. As a too proximal insertion of the graft can cause unintentional tightening of the MPFL in knee flexion, these results have to be considered when performing reconstruction of the MPFL in children and adolescents with open growth plates.

Fracture Dislocation of Carpometacarpal Joints: A Missed Injury

Fracture dislocation of the carpometacarpal joints on the ulnar side of the hand is an uncommon injury. These are high-energy injuries seen in motorcyclists and boxers. The mechanism of injury involves violent, forceful dorsiflexion of the wrist combined with longitudinal impact on the closed hand. This article reports a case of fracture of the base of the middle finger with dislocation of the ring and little finger carpometacarpal joints. On first examination, a diagnosis of isolated, minimally-displaced, middle-metacarpal base fracture was made and deemed suitable for nonoperative management. The hand was splinted in a plaster-of-Paris slab. Later, a true lateral radiograph showed the exact nature of the injury. The fracture was successfully treated with closed reduction under general anesthesia and transfixation using Kirschner wires. Functional results were excellent with return to work at 10 weeks and excellent grip strength at 14 weeks. This injury may be missed in an acute setting in a busy accident and emergency unit. Swelling around the wrist with shortening of the knuckle should alert the clinician towards the possibility of such an injury. On routine anteroposterior view, overlap of joint surfaces, loss of parallelism, and asymmetry at the carpometacarpal joints should raise suspicion of the possibility of a subtle carpometacarpal injury. This article highlights the importance of a high index of suspicion, a true lateral radiograph, and careful evaluation of radiographs in diagnosing these injuries. Intensive postoperative physiotherapy is vital to achieving a satisfactory outcome.

Clinical outcomes of medial patellofemoral ligament repair in recurrent (chronic) lateral patella dislocations

The specific aim of this project was to review a homogenous group of patients who had chosen to undergo medial patellofemoral ligament (MPFL) repair to stabilize their patella after repeat (chronic) patellofemoral dislocations and to record the success of this procedure in stabilizing the patella against further lateral dislocations. This is a retrospective study of 55 knees in 48 patients who underwent a repair of the medial patellofemoral ligament by a single surgeon over a 4-year period. The endpoint of the study was a documented patellofemoral dislocation or a minimum 2-year follow-up. Fifty-five knees in 48 patients underwent a MPFL repair/reattachment. Patella alta, as defined by the Insall-Salvati (I/S) ratio, was within normal limits in 6 (14%). The I/S ratio was greater than 1.2 in 38 patients (86%) and greater than 1.4 in 23 patients (52%). Trochlear dysplasia as defined by a positive crossing sign on a true lateral radiograph and/or a sulcus angle on axial view of greater than 145 was present in 45/47 (96%). Successful management of the knee as defined by no further patella dislocation occurred in 22 knees. Nineteen knees sustained a redislocation event (46%). The surgical procedure of operative repair (reattachment) of the MPFL to its femoral attachment had a significantly high rate of failure in this patient group of chronic (repeat) lateral patellar dislocators.