Abstract. Objectives. The outcomes from patella fracture have remained dissatisfactory despite advances in treatment, especially from operative fixation1. Frequently, reoperation is required following open reduction and internal fixation (ORIF) of the patella due to prominent hardware since the standard technique for patella ORIF is tension band wiring (TBW) which inevitably leaves a bulky knot and irritates soft tissue given the patella's superficial position2. We performed a systematic review to determine the optimal treatment of patella fractures in the poor host. Methods. Three databases (EMBASE/Medline, ProQuest and PubMed) and one register (Cochrane CENTRAL) were searched. 476 records were identified and duplicates removed. 88 records progressed to abstract screening and 73 were excluded. Following review of complete references, 8 studies were deemed eligible. Results. Complication rates were shown to be high in our systematic review. Over one-fifth of patients require re-operation, predominantly for removal of symptomatic for failed hardware. Average infection rate was 11.95% which is higher than rates reported in the literature for better hosts. Nevertheless, reported mortality was low at 0.8% and thromboembolic events only occurred in 2% of patients. Average range of movement achieved following operative fixation was approximately 124 degrees. Upon further literature review, novel non-operative treatment options have shown acceptable results in low-demand patients, including abandoning weight-bearing restrictions altogether and non-operatively treating patients with fracture gaps greater than 1cm. Regarding operative management, suture/cable TBW has been investigated as a viable option with good results in recent years since the materials used show comparable biomechanics to stainless steel. Additionally, ORIF with locking plates have shown favourable results and have enabled aggressive post-operative rehabilitation protocols. TBW with metallic implants has shown higher complication rates, especially for
Abstract. Objective. A common orthopaedic pain found in a wide spectrum of individuals, from young and active to the elderly is
Introduction. High-volume image guided injections (HVIGI) followed by structured rehabilitation have been shown to be effective in various musculoskeletal conditions including Achilles tendinopathy and shoulder impingement syndrome. The aim was to explore the effect of a HVIGI in Hoffa's fat pad impingement, a common cause of
Introduction. Management of the patellofemoral surface in total knee arthroplasty (TKA) remains a topic of debate. Incidence of
Shortening of patellar tendon after total knee arthroplasty (TKA) was previously reported by several studies. Its etiology still remains controversial. Patellar tendon shortening, a direct cause of patella baja, has a dramatic negative impact in terms of clinical outcomes after TKA. Main objective of this study is to assess the feasibility of utilizing a different technique with Ultrasound that is easy to use, cost-effective and able to eliminate the problem of differential magnification occurring in other techniques which count on standard x-rays and to establish the correlation between clinical outcomes and changes in patellar tendon length and thickness after TKA. The study was designed as prospective cohort and, after a minimum of 4-year-follow up period, 47 knees of 24 patients who had undergone primary TKA without patellar resurfacing were included in the study. All patients were scored with Kujala and HSS scores and all patellar tendons were evaluated with USG regarding their length and thickness. We used conventional grey-scale ultrasound imaging (US) to determine any changes in patellar tendon morphology. All cases were evaluated by the same radiologist. The patellar tendon was examined with the knee in 30° flexion. The flexion angle helped to stretch the extensor mechanism and avoid anisotropy (concavity) of the patellar tendon. The transducer was placed along the long axis of the tendon. The patellar tendon was initially examined in the longitudinal plane in order to measure the total length. Then, total length was divided into three parts and sagittal thickness was calculated at the proximal, median, and distal thirds of the patellar tendon. Both the length and thickness of the tendon were measured before surgery and at the 4th year of follow-up. Of the 47 knees that were included in our study, the mean pre-operative and postoperative length of the patellar tendon was 40.78±6.15 mm and 35.93±4.52 mm. Our results suggested significant shortening of the patellar tendon after primary TKA surgery (p<0.05). Intergroup analysis suggested that reduced sagittal thickness in the proximal third of the tendon was more strongly correlated with an increase in functional outcomes (p<0.05). Our results suggested no significant difference in clinical outcome scores between patients with increased or decreased length of the patellar tendon after TKA (p>0.05). We suggest that determining morphologic changes in sagittal thickness as well as length is important in explaining some of the ambiguous causes of
Patellofemoral osteoarthritis (PFOA) affects 32% men and 36% women over the age of 60years and is associated with
Trochlear geometry of modern femoral implants is designed for mechanical alignment (MA) technique for TKA. The biomechanical goal is to create a proximalised and more valgus trochlea to better capture the patella and optimize tracking. In contrast, Kinematic alignment (KA) technique for TKA respects the integrity of the soft tissue envelope and therefore aims to restore native articular surfaces, either femoro-tibial or femoro-patellar. Consequently, it is possible that current implant designs are not suitable for restoring patient specific trochlea anatomy when they are implanted using the kinematic technique, this could cause patellar complications, either
One of the most controversial issues in total knee replacement is whether or not to resurface the patella. In order to determine the effects of different designs of femoral component on the conformity of the patellofemoral joint, five different knee prostheses were investigated. These were Low Contact Stress, the Miller-Galante II, the NexGen, the Porous-Coated Anatomic, and the Total Condylar prostheses. Three-dimensional models of the prostheses and a native patella were developed and assessed by computer. The conformity of the curvature of the five different prosthetic femoral components to their corresponding patellar implants and to the native patella at different angles of flexion was assessed by measuring the angles of intersection of tangential lines. The Total Condylar prosthesis had the lowest conformity with the native patella (mean 8.58°; 0.14° to 29.9°) and with its own patellar component (mean 11.36°; 0.55° to 39.19°). In the other four prostheses, the conformity was better (mean 2.25°; 0.02° to 10.52°) when articulated with the corresponding patellar component. The Porous-Coated Anatomic femoral component showed better conformity (mean 6.51°; 0.07° to 9.89°) than the Miller-Galante II prosthesis (mean 11.20°; 5.80° to 16.72°) when tested with the native patella. Although the Nexgen prosthesis had less conformity with the native patella at a low angle of flexion, this improved at mid (mean 3.57°; 1.40° to 4.56°) or high angles of flexion (mean 4.54°; 0.91° to 9.39°), respectively. The Low Contact Stress femoral component had the best conformity with the native patella (mean 2.39°; 0.04° to 4.56°). There was no significant difference (p >
0.208) between the conformity when tested with the native patella or its own patellar component at any angle of flexion. The geometry of the anterior flange of a femoral component affects the conformity of the patellofemoral joint when articulating with the native patella. A more anatomical design of femoral component is preferable if the surgeon decides not to resurface the patella at the time of operation.
The biomechanics of the patellofemoral joint can become disturbed during total knee replacement by alterations induced by the position and shape of the different prosthetic components. The role of the patella and femoral trochlea has been well studied. We have examined the effect of anterior or posterior positioning of the tibial component on the mechanisms of patellofemoral contact in total knee replacement. The hypothesis was that placing the tibial component more posteriorly would reduce patellofemoral contact stress while providing a more efficient lever arm during extension of the knee. We studied five different positions of the tibial component using a six degrees of freedom dynamic knee simulator system based on the Oxford rig, while simulating an active knee squat under physiological loading conditions. The patellofemoral contact force decreased at a mean of 2.2% for every millimetre of posterior translation of the tibial component. Anterior positions of the tibial component were associated with elevation of the patellofemoral joint pressure, which was particularly marked in flexion >
90°. From our results we believe that more posterior positioning of the tibial component in total knee replacement would be beneficial to the patellofemoral joint.