Reconstructed Patellar Tendon Length after Proximal Tibia Prosthetic Replacement
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A common problem after proximal tibia prosthetic reconstruction is insufficient extensor mechanism or extensor lag. Maintaining the reconstructed patellar tendon length is an important way to minimize extensor lag. We measured the patellar tendon length and extensor lag serially. From 1994-2003, seven consecutive patients with malignant bone tumors of the proximal tibia had prosthetic reconstruction. The extensor mechanism was reconstructed by reattachment of the patellar tendon to the prosthesis with a synthetic material and augmented by a gastrocnemius flap. The patellar tendon length was measured according to the Insall-Salvati ratio. The ratios at 30 degrees knee flexion decreased immediately postoperatively, and reverted to almost the same preoperative values within 18 months. The mean ratios at 60 degrees knee flexion are significantly greater than 30 degrees at 6 months postoperatively. These findings indicate that the patellar tendon stretched, whereas the extensor lag improved continuously for 12 months postoperatively. In the revision at 22 months postoperatively, although the patellar tendon was not reattached to the replaced prosthesis, the ratio and the extensor lag had not worsened. These results show that providing strong continuity of the patellar tendon, gastrocnemius flap, and leg extensors can decrease the extensor lag, although the patellar tendon stretches.Keywords:
Patellar ligament
Quadriceps tendon
Tibial tuberosity
Patellar ligament
Quadriceps tendon
Quadriceps muscle
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Morphometric analyses of the patella and patellar ligament have been reported to be important in human identification, in knee implant design and in certain surgical procedures of the knee. It has also been shown that success in the functionality of a knee arthroplasty (knee replacement) is dependent on the implant being of an appropriate dimension. We undertook this study because of the lack of available data on these dimensions in South Africans. Careful dissection was carried out on both knees of 46 South African cadavers (25 females and 21 males) of European ancestry. The quadriceps femoris tendon and patellar ligament were carefully freed from the underlying structures. Eight measurements of the patella and patellar ligament were taken using a Vernier caliper. Patellae were also classified based on the dimensions of the articular facets. No significant difference was found when the measurements taken from both knees were compared except for the dimensions of patella thickness and widths. Dimensions of the patella, patellar ligament and articular facets are sexually dimorphic. In addition, measurements of the patella and patellar ligament showed significant positive correlations, with Type B patellae being the most prevalent in South Africans of European ancestry. The data from the present study will be beneficial in clinical and pathological practices and for local anthropological records.
Quadriceps tendon
Patellar ligament
Calipers
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Retinaculum
Quadriceps tendon
Patellar ligament
Vastus medialis
Infrapatellar fat pad
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Patella alta has been identified as an important risk factor for lateral patellar instability and medial patellofemoral complex (MPFC) reconstruction failure.To evaluate the length changes of the MPFC at multiple possible reconstruction locations along the extensor mechanism in varying degrees of patella alta throughout knee motion.Controlled laboratory study.Eight fresh-frozen cadaveric knees were used in this study. The MPFC was identified and dissected with the patellar tendon and quadriceps tendon. A custom-made jig was utilized to evaluate lengths from 0° to 90° of flexion with physiological quadriceps loading. Length was measured with a 3-dimensional robotic arm at 4 possible reconstruction locations along the extensor mechanism: the midpoint patella (MP), the MPFC osseous center (FC), the superior medial pole of the patella (SM) at the level of the quadriceps insertion, and 1 cm proximal to the SM point along the quadriceps tendon (QT). These measurements were repeated at 0°, 20°, 40°, 60° and 90° of flexion. Degrees of increasing severity of patella alta at Caton-Deschamps index (CDI) ratios of 1.0, 1.2, 1.4, and 1.6 were then investigated.Patella alta and MPFC attachment site location significantly affected changes in MPFC length from 0° to 90° of flexion (P< .0005). Length changes at attachment MP showed no difference when CDI 1.0 was compared with all patella alta values (CDI 1.2, 1.4, 1.6; P > .05). Similarly, FC showed no difference in length change from 0° to 90° until CDI 1.6, in contrast to proximal attachments (SM, QT), which demonstrated significant changes at CDI 1.4 and 1.6. When length changes were analyzed at each degree of flexion (0°, 20°, 40°, 60°, 90°), Spearman correlation analysis showed a moderate negative linear correlation for QT at CDI 1.0 (r= -0.484; P = .002) and 1.6 (r = -0.692; P < .0005), demonstrating constant loosening at the QT point at normal and elevated patellar height. In contrast, no differences in length were observed for MP at CDI 1.0 throughout flexion, and at CDI 1.6, there was a difference only at 0° (P < .05). Points FC and MP at CDI 1.6 had similar length change properties to points SM and QT at CDI 1.0 (P > .05), suggesting that distal attachments in the setting of patella alta may provide similar length changes to proximal attachmentswith normal height.Anisometry of the MPFC varies not only with attachment location on the extensor mechanism but also with patellar height. Increased patellar height leads to more significant changes in anisometry in the proximal MPFC attachment point as compared with the distal component. In the setting of patella alta, including a CD ratio of 1.6, the osseous attachments of the MPFC remain nearly isometric wheras the proximal half length changes increase significantly.The results of this study support the idea that the MPFC should be considered as 2 separate entities (proximal medial quadriceps tendon femoral ligament and distal medial patellofemoral ligament) owing to their unique length change properties.
Cadaveric spasm
Quadriceps tendon
Patellar ligament
Medial Patellofemoral Ligament
Knee flexion
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Morphometric analyses of the patella and patellar ligament have been reported to be important in human identification, in knee implant design and in certain surgical procedures of the knee. It has also been shown that success in the functionality of a knee arthroplasty (knee replacement) is dependent on the implant being of an appropriate dimension. We undertook this study because of the lack of available data on these dimensions in South Africans. Careful dissection was carried out on both knees of 46 South African cadavers (25 females and 21 males) of European ancestry. The quadriceps femoris tendon and patellar ligament were carefully freed from the underlying structures. Eight measurements of the patella and patellar ligament were taken using a Vernier caliper. Patellae were also classified based on the dimensions of the articular facets. No significant difference was found when the measurements taken from both knees were compared except for the dimensions of patella thickness and widths. Dimensions of the patella, patellar ligament and articular facets are sexually dimorphic. In addition, measurements of the patella and patellar ligament showed significant positive correlations, with Type B patellae being the most prevalent in South Africans of European ancestry. The data from the present study will be beneficial in clinical and pathological practices and for local anthropological records.
Patellar ligament
Quadriceps tendon
Calipers
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Abstract The patella is the largest sesamoid bone of the skeleton. It is strongly involved in the knee, improving output force and velocity of the knee extensors, and thus plays a major role in locomotion and limb stability. However, the relationships between its structure and functional constraints, that would enable a better understanding of limb bone functional adaptations, are poorly known. This contribution proposes a comparative analysis, both qualitative and quantitative, of the microanatomy of the whole patella in perissodactyls, which show a wide range of morphologies, masses, and locomotor abilities, in order to investigate how the microanatomy of the patella adapts to evolutionary constraints. The inner structure of the patella consists of a spongiosa surrounded by a compact cortex. Contrary to our expectations, there is no increase in compactness with bone size, and thus body size and weight, but only an increase in the tightness of the spongiosa. No particular thickening of the cortex associated with muscle insertions is noticed but a strong thickening is observed anteriorly at about mid‐length, where the strong intermediate patellar ligament inserts. The trabeculae are mainly oriented perpendicularly to the posterior articular surface, which highlights that the main stress is anteroposteriorly directed, maintaining the patella against the femoral trochlea. Conversely, anteriorly, trabeculae are rather circumferentially oriented, following the insertion of the patellar ligament and, possibly also, of the quadriceps tendon. A strong variation is observed among perissodactyl families but also intraspecifically, which is in accordance with previous studies suggesting a higher variability in sesamoid bones. Clear trends are nevertheless observed between the three families. Equids have a much thinner cortex than ceratomorphs. Rhinos and equids, both characterized by a development of the medial border, show an increase in trabecular density laterally suggesting stronger stresses laterally. The inner structure in tapirs is more homogeneous despite the absence of medial development of the medial border with no “compensation” of the inner structure, which suggests different stresses on their knees associated with a different morphology of their patellofemoral joint.
Sesamoid bone
Quadriceps tendon
Patellar ligament
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Enthesis
Patellar ligament
Quadriceps tendon
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One hundred twenty-one patients were prospectively studied to determine whether the different remaining patellar tendon widths after central 10-mm bone-patellar tendon-bone graft harvest influenced the rate and level of quadriceps strength achieved during rehabilitation. Size of the patellar tendon width, measured at the same location in each patient, ranged from 24 to 35 mm. For this study, patients were grouped according to their remaining tendon size into small (14 to 17 mm; mean, 15.8), medium (18 to 20 mm; mean, 19.2), and large (21 to 25 mm; mean, 22.5) widths. Postoperatively, the patient's isokinetic quadriceps scores were determined at 6 weeks, 3 months, 6 months, and 1 year. At 6 weeks, the small- and medium-width tendon groups were significantly weaker than the large-width tendon group. At 3 months, only the small-width tendon group continued to be significantly weaker than the large-width tendon group. At and beyond 6 months, no statistically significant differences were seen between remaining patellar tendon width groups and their isokinetic quadriceps scores. A constant-sized autogenous patellar tendon graft may be harvested for anterior cruciate ligament reconstruction without compromising ultimate postoperative quadriceps strength recovery.
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Patellar ligament
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Patellar maltracking after total knee arthroplasy (TKA) introduces complications such as anterior knee pain and patellar subluxation, generally due to prosthetic component malallignment in both tibiofemoral (TF) and patellofemoral joints. It is still debated if it is necessary to resurface the patella, which would better adapt the patellar articular surface to the prosthetic femoral troclea with a prosthesis, but also result in possible bone fractures. In this study, an in-vitro analysis is presented in order to identify differences between intact and TKA patellar tracking with and without patellar resurfacing and to show how much the latter is similar to intact knee patellar tracking. Three fresh-frozen amputated legs with knees free from anatomical defects and with intact joint capsule, collaterals and quadriceps tendon were analyzed using the Stryker knee navigation system (Kalamazoo, MI-USA). Landmark digitations were used to define anatomical frames for femur, tibia and patella. Manually driven TF flexions, from 0 to 140, were performed under conditions of no load and of 10 kg on the quadriceps, with intact knee and TKA with patella resurfaced and not. TF flex/extension, intra/extra rotation, ad/abduction were calculated according to a standard convention. Patellar flex/extension, medial/lateral tilt, rotation and shift were calculated according to a recently proposed articular convention. Since more repeatable, results relative to trials under 10 kg are reported. Intact knee: 4 abduction; considerable intra rotation (from 16 to 4), followed by continuous extra rotation starting at 30 TF flexion; linear increase in patellar flexion (from 20 to 110); initial medial patellar rotation (from 12 to 8), followed by medial rotation starting at 60 TF flexion; initial lateral patellar tilt (from 4 lateral to 4 medial), followed by medial tilt starting at 70 TF flexion; initial 6 mm lateral patellar shifts from 0 to 80 TF flexion, followed by 4 mm medial shift. TKA knee: small differences in ad/abduction between intact and TKA knees, both with and without resurfaced patella; slight initial extra rotation, followed by continuous intra rotation starting at 20 TF flexion; linear increase in the flexion of the patella, both resurfaced and not, close to the that of the intact knee; patellar rotation more lateral than in the intact knee; patellar tilt without resurfaced patella closer to the intact knee one; 6 mm lateral patellar shift, likely accounted for the surgical technique. Slightly more than TKA with resurfaced patella, TKA with non resurfaced patella flexes nearly like the intact knee. The closeness in values of patellar flexion and tilt represents a proof of the closeness in behavior of not resurfaced patella in TKA to the patella in the intact knee.
Quadriceps tendon
Anterior knee pain
Patellar ligament
Subluxation
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To study the diagnosis and treatment of rupture of patella ligament and Femoral quadriceps tendon.Twenty-three patients with rupture of the patella ligament and femoral quadriceps tendon were treated from March 1990 to August 2000. They were retrospectively evaluated with regard to patient's age, cause of injuries, characteristics of injuries, symptoms and signs, supplemental checkup, patella position, operative method and time interval from injury to treatment, immobilization, motion of knee, functional recovery etc.They were followed up for 6 years (4 months-11 years) on average. Thirteen of 15 acute injuries after treatment showed excellent results and good results in 2. In 5 old injuries of the extensor mechanism after treatment 2 got excellent results (3 lost to follow-up).Excellent or good results could obtain in patients with acute injuries after operation. The results of old injuries are not as good as acute injures, but better results could also achieve after repair.
Quadriceps tendon
Patellar ligament
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