Pseudo-Patella Baja after total knee arthroplasty

Kazemi, Seyyed Morteza; Besheli, Laleh Daftari; Eajazi, Alireza; Sajadi, Mohammad Reza Miniator; Okhovatpoor, Mohammad Ali; Zanganeh, Ramin Farhang; Minaei, Reza

doi:10.12659/msm.881770

Cited by 65 publications

(61 citation statements)

References 16 publications

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“…In addition, we found that cartilage stress plateaued when patella height had been corrected close to normal (InsallSalvati ratio approximately 1.0); further distalization did not provide lower values. Clinically, a low-lying patella or elevated tibiofemoral joint line also may lead to several complications such as joint stiffness, decreased ROM, and anterior knee pain [11,14,28]. Therefore, we advocate proper distalization of the tibial tubercle to correct the Insall-Salvati ratio to normal.…”

Section: Discussionmentioning

confidence: 99%

Does Patella Tendon Tenodesis Improve Tibial Tubercle Distalization in Treating Patella Alta? A Computational Study

Liao

Yang

et al. 2016

Clinical Orthopaedics &Amp; Related Research

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Background Patellofemoral malalignment associated with patella alta may cause pain and arthritis; because of this, the condition sometimes is treated surgically. Two common procedures are tibial tubercle distalization with or without patellar tendon tenodesis. However, the biomechanical consequences of these interventions for patella alta are not clearly understood. Questions/purposes We evaluated changes in patellofemoral joint contact mechanics after tibial tubercle distalization and tibial tubercle distalization combined with patella tendon tenodesis. Specifically, we asked: (1) Are there biomechanical differences between these two types of procedures? (2) Is there an ideal range to distalize the patella? Methods Subject-specific finite-element models were created for 10 individuals with patella alta (mean InsallSalvati ratio of 1.34 ± 0.05). Input parameters for the finite-element models included subject-specific joint geometry, quadriceps muscle forces, and weightbearing patellofemoral joint kinematics. Virtual operations were conducted to simulate the two procedures. For distalization, the tibial tubercle and patella were displaced distally 4 mm to 20 mm in 4-mm increments based on the original model. At each level of distalization, the patella tendon was attached back to its original insertion to simulate the additional tenodesis procedure. Cartilage stress, contact area, and contact forces were quantified and compared between procedures and distalization levels. Results Distalization and distalization + tenodesis reduced patellofemoral joint stress compared with the baseline of 1.02 ± 0.11 MPa. Distalization led to lower cartilage stress than distalization + tenodesis, and the effect size was relatively large (0.88 ± 0. Conclusions Cartilage stress appears lower using distalization as opposed to distalization + tenodesis in this finite-element analysis simulation. An Insall-Salvati ratio of 0.95 may be an ideal level for distalization; further distalization does not show additional benefits. Clinical Relevance This study suggests that distalization may result in less stress than distalization + tenodesis,

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Section: Discussionmentioning

confidence: 99%

Does Patella Tendon Tenodesis Improve Tibial Tubercle Distalization in Treating Patella Alta? A Computational Study

Liao

Yang

et al. 2016

Clinical Orthopaedics &Amp; Related Research

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“…Some reports have suggested that patellar baja increases the risk of patellar fracture. [34][35][36] Although the position and resection angle of the patellar component were not found to be a significant risk, patellar over resection and increased delta patellar tilting angle did increase the incidence of patellar fracture. These factors probably compromise the mechanical strength of the patella.…”

Section: Discussionmentioning

confidence: 85%

A case-control study of spontaneous patellar fractures following primary total knee replacement

Seo

Moon

Park

et al. 2012

The Journal of Bone and Joint Surgery. British volume

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Peri-prosthetic patellar fracture following resurfacing as part of total knee replacement (TKR) is an infrequent yet challenging complication. This case-control study was performed to identify clinical, radiological and surgical factors that increase the risk of developing a spontaneous patellar fracture after TKR. Patellar fractures were identified in 74 patients (88 knees) from a series of 7866 consecutive TKRs conducted between 1998 and 2009. After excluding those with a previous history of extensor mechanism realignment or a clear traumatic event, a metal-backed patella, any uncemented component or subsequent infection, the remaining 64 fractures were compared with a matched group of TKRs with an excellent outcome defined by the Knee Society score. The mean age of patients with a fracture was 70 years (51 to 81) at the time of TKR. Patellar fractures were detected at a mean of 13.4 months (2 to 84) after surgery. The incidence of patellar fracture was found to be strongly associated with the number of previous knee operations, greater pre-operative mechanical malalignment, smaller post-operative patellar tendon length, thinner post-resection patellar thickness, and a lower post-operative Insall-Salvati ratio. An understanding of the risk factors associated with spontaneous patellar fracture following TKR provides a valuable insight into prevention of this challenging complication.

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“…19,20 Kazemi et al study done in 2010, on 60 patients (with prior patella baja patient exclusion) shows 43 had no joint line elevation or patellar tendon shortening. 21 Divided patients into 3 groups-Group A had no patella baja or pseudo-patella baja, Group B had pseudo-patella baja and Group C had patella baja and pseudo-patella baja patients. 15 patients demonstrated joint line elevation, and both patella baja and pseudo-patella baja were present in 2 patients.…”

Section: Resultsmentioning

confidence: 99%

“…About 25 to 30% of TKRs may develop patella infera. 7 The current study was designed so as to assess whether jointline elevation and change in patellar tendon length influences knee flexion after primary cruciate retaining TKR.…”

Section: Introductionmentioning

confidence: 99%

Influence of prosthetic joint line position on outcome after total knee replacement

Choudhary

Bahre²

2017

Int J Res Orthop

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Background: The current study had been designed so as to assess whether joint line elevation and change in patellar tendon length influences knee flexion after primary cruciate retaining TKR.Methods: This prospective study involved patients with advanced degenerative joint disease involving one or both knees who presented to the outpatient department of a tertiary care hospital. Exclusion criteria were any prior knee surgery. Surgery was performed under tourniquet with standard medial para-patellar arthrotomy to expose all our knees. In the study radiological assessment was done by true lateral X-ray view of knee in 30 degree of flexion. We choose Caton-Deschamps indices (CI) for diagnosis of post TKR patella infera and joint line elevation. CI<0.6 was defined as patella infera (normal range of CI 0.60-1.45). After all data collection comparison was done between joint line elevation versus without joint line elevation patients (with/without patellar tendon shortening) range of movement.Results: Total of 100 patients (72 females and 28 males) with 176 knees (bilateral=76, unilateral=24) who fulfilled the above said criteria involved in study. The mean age of the patients at the time of surgery was 64.4 years with range of 54 years to 80 years. The average follow up of 24 months, with minimum follow up of 18 months. Average range of motion (ROM) in NO Joint line elevation/patella tendon shortening patient measured 107.2°, and joint line elevation with patellar tendon shortening (prior patella infera) and joint line elevation without patella tendon shortening(prior patella infera) patient average ROM was measured 86.7 and 87.8 degree respectively.Conclusions: In our study patellar tendon shortening and joint line elevation reduces ROM knee. Mechanical factors also explain the association between joint line elevation and patellar tendon length with range of motion. Reduction in length of extensor apparatus reduces the range of flexion.

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Pseudo-Patella Baja after total knee arthroplasty

Cited by 65 publications

References 16 publications

Does Patella Tendon Tenodesis Improve Tibial Tubercle Distalization in Treating Patella Alta? A Computational Study

Does Patella Tendon Tenodesis Improve Tibial Tubercle Distalization in Treating Patella Alta? A Computational Study

A case-control study of spontaneous patellar fractures following primary total knee replacement

Influence of prosthetic joint line position on outcome after total knee replacement

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