We evaluated the outcome in a series of patients with recurrent patellar dislocation who had either medial transfer of the tibial tuberosity and lateral release or an isolated lateral release as the primary treatment. The decision to use one or other procedure was based on a pre-operative distance between the tibial tuberosity to the trochlear groove (TTTG) of less than 10 mm to include the tibial tuberosity transfer in addition to the lateral release. Between April 2002 and December 2006, 49 patients (63 knees) underwent one of these procedures. A total of 35 patients (46 knees) was evaluated at a mean of 38 months (13 to 71) post-operatively. Medial transfer of the tibial tuberosity was performed in 33 knees and isolated lateral release in the remaining 13. Evaluation included the International Knee Documentation Committee (IKDC), the Kujala and the Short-form 36 scores. From the tibial tuberosity group 23 knees also underwent radiological examination at follow-up. There were further episodes of patellar dislocation in six of the 46 knees available for review. Further dislocation was noted in five of 33 knees (15.2%) in the tibial tuberosity transfer group and in one of 13 knees (7.7%) in the lateral release group. The mean subjective IKDC score was 80.4 (. sd. 11.6), the mean Kujala score 88 (. sd. 8.2) and the mean objective IKDC score was 79% normal and 21% nearly normal. The mean post-operative TTTG distance in the tibial tuberosity transfer group was 8.9 mm (3.2 to 15.7) compared with the mean pre-operative value of 16.8 mm (12.2 to 24.4)

Introduction. Tibial tuberosity and trochlear groove (TT-TG) distance has been investigated for the patients with primary patellofemoral subluxation/dislocation. To date, TT-TG distance after TKA has not been evaluated, and the effect of postoperative TT-TG distance on patellar tracking is unknown. The purpose of the current study was to investigate the effect of TT-TG distance and rotational position of the femoral and tibial components on patellar tilt after TKA. Methods. Consecutive 115 knees for the diagnosis of osteoarthritis were included in the current study. TKA was performed using posterior cruciate ligament sacrificed prosthesis. A total of 17 men and 96 women with an average age of 75.3 years were included at the time of the surgery. Computed tomography (CT) was taken after TKA in full extension. Postoperative TT-TG distance was measured as a reference of surgical epicondylar axis (SEA) of the femur. Patellar tilt was defined as the angle of the patellar component relative to SEA. Femoral and tibial component rotation was measured as the angle relative to SEA and tibial antero-posterior (AP) axis. Tibial AP axis was defined as the line connecting medial one-third of the tibial tuberosity and center of medial-lateral width. Pearson correlation coefficients were calculated to determine the correlations between patellar tilt and TT-TG distance and between patellar tilt and femoral and tibial component rotation. Results. TT-TG distance had significant correlation with patellar tilt (Figure 1; r = 0.254, p = 0.006), whereas femoral component rotation (p = 0.092) and tibial component rotation (p = 0.062) were not correlated with patellar tilt. Concerning the effect on TT-TG distance, femoral component rotation (r = 0.248, p = 0.008) and tibial component rotation (r = −0.567, p < 0.001) were correlated with TT-TG distance. Conclusion. The current study investigated the effect of TT-TG distance on patellar tilt with postoperative CT scan. Greater TT-TG distance resulted in more patellar tilt, which might have negative effects on patellar tracking. In previous clinical studies, femoral component and tibial component rotation affected patellar maltracking. In the current study, however, component rotation itself did not affect patellar tilt. Postoperative TT-TG distance includes information of rotational and medial-lateral positioning of the femoral and tibial components, and can be a useful indicator to predict patellar maltracking after TKA. For any figures or tables, please contact authors directly

An abnormal lateral position of the tibial tuberosity causes distal malalignment of the extensor mechanism of the knee and can lead to lateral tracking of the patella causing anterior knee pain or objective patellar instability, characterised by recurrent dislocation. Computer tomography is used for a precise pre-operative assessment of the tibial tubercle-trochlear groove distance. A distance of more than 15 mm is considered to be pathological and an indication for surgery in symptomatic patients. In a prospective study we performed a subtle transfer of the tibial tuberosity according to the information gained from the pre-operative CT scan. This method was applied to two groups of patients, those with painful lateral tracking of the patella, and those with objective patellar instability. We evaluated the clinical results in 30 patients in each group. The outcome was documented at 3, 12 and 24 months using the Lysholm scale, the Kujala score, and a visual analogue pain score. Post-operatively, all but one patient in the instability group who had a patellar dislocation requiring further surgery reported good improvement with no further subluxation or dislocation. All patients in both groups had a marked improvement in pain and functional score. Two patients sustained a tibial fracture six and seven weeks after surgery. One patient suffered a per-operative fracture of the tibial tubercle which later required further fixation. If carefully performed, this type of transfer of the tibial tubercle appears to be a satisfactory technique for the treatment of patients with an increased tibial tubercle-trochlear groove distance and who present with symptoms related to lateral maltracking of the patella

The Q angle is an important determinant of patellar tracking, though its clinical relevance is debatable. One controversy centres around any possible differences in its value between men and women. The accepted, though unproven explanation, for the greater Q angle in women is that a woman has a wider pelvis. However, because of the long distance between the pelvis and patella, relative to the distance from the patella to the tibial tuberosity, large changes in the position of the anterior superior iliac spine are necessary to effect significant changes in the Q angle. In our study of 69 subjects, we did not find such large differences in the position of the anterior superior iliac spine, and found a mean difference of only 2.3° between the Q angles of men and women. Furthermore, we found that men and women of equal height demonstrated similar Q angles, with taller people having slightly smaller Q angles. The slight difference in Q angles between men and women can be explained by the fact that men tend to be taller

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As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA).

Aim. The aim of this study was to study the course of the infra-patellar branch of the saphenous nerve (IPBSN) and describe its anatomical variations and relations. Materials and Methods. Twenty-eight formalin-fixed cadaver lower extremity specimens were methodically dissected in the University Department of Anatomy. Dissection included identifying the saphenous nerve and tracing it distally till it pierced the deep fascia between the tendons of gracilis and sartorius. At this point, the saphenous nerve gave a branch that pierced the sartorius and became subcutaneous, known as the infrapatellar branch. The association of the nerve trunk with the sartorius muscle in terms of whether it originated above it, below it or pierced through it was studied. Following this the nerve was dissected along its course distally to the point of its termination where it gave one to three branches. The relationship of the point of termination of the IPBSN with bony surface landmarks like the medial border of the patella, the apex of the patella and the tibial tuberosity were also studied. The distance of the trunk from medial margin of patella was measured. Conclusions. The anatomy of the IPBSN along with its branches is quite variable and a thorough knowledge of the same is essential to any knee surgeon to avoid injury to this structure

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The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective.

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In cases of severe periprosthetic joint infection (PJI) of the knee, salvage procedures such as knee arthrodesis (KA) or above-knee amputation (AKA) must be considered. As both treatments result in limitations in quality of life (QoL), we aimed to compare outcomes and factors influencing complication rates, mortality, and mobility.

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Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity.

Statement of purpose. To determine whether the Q-angle, measured in a defined and reproducible manner, correlates with the TT-TG distance in patients with patellar instability. Methods and results. The Q-angle represents the angle between the vector of action of the quadriceps and patellar tendon. The normal angle is 14. +/−. 3° in males and 17. +/−. 3° in females. An increased Q-angle is associated with an increased risk of patellar instability, although there is disagreement on its reliability and validity. It can be affected by the anatomical points used to record the measurement, the position of the limb and whether the quadriceps are relaxed or contracted. TT-TG is ascertained by axial CT scanning, with a value exceeding 20mm associated with patellar instability. Q-angles were measured in patients presenting to the patella clinic who had previously undergone Lyon protocol CT scanning for patellar instability. Patients were positioned supine with both feet in neutral rotation taped to a specially designed wooden board (the same position used for CT scanning). The anatomical landmarks were the anterior superior iliac spine, the centre of the patella and the centre of the tibial tuberosity. Both knees were measured with the quadriceps relaxed (relaxed Q-angle) and contracted (contracted Q-angle). Thirty-four knees were measured, 24 pathological and 10 non-pathological. Pearson moment correlation demonstrated a significant correlation between relaxed Q-angle and TT-TG in all knees (R=-0.377; p=0.028). In pathological knees, contracted Q-angle also demonstrated a significant correlation with TT-TG but to a lesser extent than relaxed Q-angle (R=-0.428; p=0.037, R=-0.578; p=0.003 respectively). Linear regression analysis demonstrated relaxed Q-angle as a significant predictor of TT-TG distance in pathological knees. Contracted Q-angle was not significant. Conclusion. The relaxed Q-angle, when measured as above, reliably correlates with and is a significant predictor of TT-TG distance in patients with symptomatic patellar instability

A controlled study, comparing computer- and conventional jig-assisted total knee replacement in six cadavers is presented. In order to provide a quantitative assessment of the alignment of the replacements, a CT-based technique which measures seven parameters of alignment has been devised and used. In this a multi-slice CT machine scanned in 2.5 mm slices from the acetabular roof to the dome of the talus with the subject’s legs held in a standard position. The mechanical and anatomical axes were identified, from three-dimensional landmarks, in both anteroposterior and lateral planes. The coronal and sagittal alignment of the prosthesis was then measured against the axes. The rotation of the femoral component was measured relative to the transepicondylar axis. The rotation of the tibial component was measured with reference to the posterior tibial condyles and the tibial tuberosity. Coupled femorotibial rotational alignment was assessed by superimposition of the femoral and tibial axial images. The radiation dose was 2.7 mSV. The computer-assisted total knee replacements showed better alignment in rotation and flexion of the femoral component, the posterior slope of the tibial component and in the matching of the femoral and tibial components in rotation. Differences were statistically significant and of a magnitude that support extension of computer assistance to the clinical situation

Purpose of Study. 1- To introduce a new graft technique for ACL reconstruction using the patellar tendon with its attachment on the tibial tuberosity as bone-tendon (B PT) auto graft sparing the patella. 2-To assess the above described technique prospectively in a group of patients with ACL deficient knees. Type of study. Prospective case series of a newly describedACL graft technique. Material and methods. 44 patients with ACL deficient knee (with no other ligament injuries) were recruited to have ACL reconstruction using the above mentioned graft technique, there was 39 males and 5 females, average age at the index surgery was 24,4 year (range 20-40), the average time from injury to operation was 4 months (range 1 week to 1 year), the average follow up period was 30 months (ranged 24-35), there was 19 patients with isolated ACL injury and 25 with associated intra articular pathology including 22 meniscal tear, 8 with articular cartilage injury (3 of them associated with the meniscal tears). Those injuries were treated with meniscal repair (12 cases), partial menisectomy (10 cases), debridement and shaving +/− micro fracture technique for the articular cartilage injuries. Results. at the final follow up all patients were satisfied with their knees, the IKDC improved from 68 +- 2.8(pre-op) to 92 +- 2.7 (CI-95%), and Lysholm score from 65 +- 3.2 to 93 +- 3(CI-95%) at the final visit. Anterior knee pain was reported in 4 patients (9%) on moderate to strenuous activities. 7 patients (16%) could not return to their pre-injury activity level. The mean difference in KT-1000 measurement was 2 +- 0.8. Conclusion. our technique is effective with compatible results with other ACL graft's technique with less complications rate when compared with PBTB auto graft, it avoids the remote incidence of patellar fractures, and reducing the incidence of anterior knee pain

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The objective of this study was to compare the two-year migration pattern and clinical outcomes of a total knee arthroplasty (TKA) with an asymmetrical tibial design (Persona PS) and a well-proven TKA with a symmetrical tibial design (NexGen LPS).

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The objectives of this study were to assess the effect of anterior cruciate ligament (ACL) resection on flexion-extension gaps, mediolateral soft tissue laxity, maximum knee extension, and limb alignment during primary total knee arthroplasty (TKA).

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The Oswestry-Bristol Classification (OBC) was recently described as an MRI-based classification tool for the femoral trochlear. The authors demonstrated better inter- and intraobserver agreement compared to the Dejour classification. As the OBC could potentially provide a very useful MRI-based grading system for trochlear dysplasia, it was the aim to determine the inter- and intraobserver reliability of the classification system from the perspective of the non-founder.

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The purpose of this study was to explore the correlation between femoral torsion and morphology of the distal femoral condyle in patients with trochlear dysplasia and lateral patellar instability.

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The extensive variation in axial rotation of tibial components can lead to coronal plane malalignment. We analyzed the change in coronal alignment induced by tray malrotation.

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The aim of this study was to assess the effect of posterior cruciate ligament (PCL) resection on flexion-extension gaps, mediolateral soft-tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilized (PS) total knee arthroplasty (TKA).

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The aims of this study were to determine the effect of osteophyte excision on deformity correction and soft tissue gap balance in varus knees undergoing computer-assisted total knee arthroplasty (TKA).

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The aim of this study was to determine and compare the congruency of the articular surface contact area of the patellofemoral joint (PFJ) during both active and passive movement of the knee with the use of an MRI mapping technique in both the stable and unstable PFJ.