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The Knee Oct 2023Recurrent patella instability is a common and debilitating condition which affects mainly adolescents and young adults. Medial patellofemoral ligament (MPFL)...
BACKGROUND
Recurrent patella instability is a common and debilitating condition which affects mainly adolescents and young adults. Medial patellofemoral ligament (MPFL) reconstruction is the most popular surgical treatment for recurrent patella instability. The most common graft choice in the literature is ipsilateral hamstring tendon (gracilis or semitendinosis) but the complication rate remains high (11-26%). Conversely, there are very few papers on the use of modern, synthetic grafts.
METHODS
A total of 85 patients who underwent MPFL reconstruction using a modern, synthetic graft (Xiros, UK) from 2014 to 2022 were retrospectively reviewed. Exclusion criteria were patella alta, malalignment, trochlea dysplasia and significant pain between episodes of instability. The author has developed an operative technique which is anatomic, minimally invasive and reproducible. Pre- and post-operative Kujala and Oxford knee scores were collected and analysed.
RESULTS
The male to female ratio was 27:58, the average age was 28 years, and the follow up range was 1-9 years (mean follow up 4.84 years). We found a statistically significant improvement in mean Kujala and Oxford knee scores (P < 0.001) postoperatively. No major complications such as knee stiffness, soft tissue reaction, re-dislocation, patella fracture were identified in the series. There were nine minor complications (10.6%): five cases of medial knee pain, two cases of residual instability and two of superficial infection.
CONCLUSION
This study demonstrates that modern, synthetic graft is a viable option for MPFL reconstruction. The technique described, achieves good clinical outcomes with low complication rates when compared with the published literature.
Topics: Adolescent; Young Adult; Humans; Male; Female; Infant; Child, Preschool; Child; Patellar Dislocation; Patellofemoral Joint; Retrospective Studies; Patella; Ligaments, Articular; Joint Instability; Pain; Treatment Outcome
PubMed: 37672914
DOI: 10.1016/j.knee.2023.08.004 -
Veterinary Medicine and Science May 2023A 2-day-old Cleveland Bay colt was referred to the Equine Emergency Service of the Farm Animal and Equine Veterinary Medical Center at North Carolina State University's...
A 2-day-old Cleveland Bay colt was referred to the Equine Emergency Service of the Farm Animal and Equine Veterinary Medical Center at North Carolina State University's College of Veterinary Medicine for evaluation of decreased nursing behaviour and right hindlimb lameness of 2 days' duration. When assisted to stand, the foal was unable to extend either hindlimb or bear weight on the hindlimbs, the right patella was luxated laterally and unable to be reduced, and the foal assumed a crouched position. Stifle radiographs revealed minimal, heterogeneous, ill-defined ossification of both patellae. Due to the severity of the musculoskeletal defects, humane euthanasia was elected. Post-mortem examination identified a congenital malformation of both patella bones with failure of ossification and cardiac changes suggestive of right atrioventricular valve dysplasia. Histology of the patellae showed no evidence of osteoid deposition or ossification. To our knowledge, bilateral congenital patellar aplasia has not been previously described in foals.
Topics: Animals; Horses; Male; Patella; Hindlimb; Animals, Domestic; Horse Diseases
PubMed: 36734120
DOI: 10.1002/vms3.1083 -
Journal of Orthopaedic Surgery and... Apr 2023Patellar resurfacing is considered the standard of care for total knee arthroplasty in the USA. Complications of patella resurfacing include aseptic loosening or patella...
PURPOSE
Patellar resurfacing is considered the standard of care for total knee arthroplasty in the USA. Complications of patella resurfacing include aseptic loosening or patella fractures and can threaten the integrity of the extensor mechanism. The goal of this study was to report on patella button revision rates in posterior stabilized total knee arthroplasty.
MATERIAL AND METHODS
Between 01/2010 and 08/2016 patella buttons were implanted in 1056 patients (267 men and 550 women) as part of a posterior stabilized total knee arthroplasty.
RESULTS
Of 1056 cases, 35 cases (14 women, 15 men, 5 bilateral, 3.3%) showed early loosening at a mean 52.5 months postoperatively. Patella components of 38 mm or larger diameters showed a significantly higher loosening rate than the 29, 32, 35 mm buttons (p < 0.01). Mean BMI of patients identified with aseptic loosening was 31.7 kg/m, mean age at time of revision surgery was 63.3 years. All of the patients with loosening of the patella button required revision surgery; in 33 cases an exchange of the button was performed, in two cases a removal of the button and patellar bone grafting was indicated. No complications occurred after revision surgery.
CONCLUSION
The current study reports a 3.3% patella loosening rate during this mid-term follow-up. Size 38 mm and larger patella components showed a significantly higher revision rate than smaller buttons and the authors advise caution when using large diameter patella components.
Topics: Male; Humans; Female; Middle Aged; Patella; Arthroplasty, Replacement, Knee; Knee Prosthesis; Bone Transplantation; Reoperation
PubMed: 37106469
DOI: 10.1186/s13018-023-03705-9 -
The American Journal of Sports Medicine Dec 2023Adolescents who experience a patellar dislocation have an elevated risk of patellofemoral posttraumatic osteoarthritis. Magnetic resonance imaging (MRI)-based T1ρ...
BACKGROUND
Adolescents who experience a patellar dislocation have an elevated risk of patellofemoral posttraumatic osteoarthritis. Magnetic resonance imaging (MRI)-based T1ρ relaxation times were measured for adolescents to evaluate patellofemoral cartilage after patellar dislocation. Long T1ρ relaxation times are an indicator of cartilage degradation.
HYPOTHESIS
The primary hypothesis is that patellofemoral cartilage T1ρ relaxation times will be elevated in the acute phase after patellar dislocation. The secondary hypothesis is that T1ρ relaxation times will be higher for knees with multiple rather than single dislocations due to repeated traumatic injury.
STUDY DESIGN
Cross-sectional study; Level of evidence, 3.
METHODS
In total, 23 adolescents being treated for a recent patellar dislocation, 13 for a first-time dislocation (47 ± 38 days since most recent dislocation) and 10 for multiple dislocations (55 ± 24 days since most recent dislocation), and 10 healthy controls participated in MRI-based T1ρ relaxation time mapping. For multiple regions of the patellofemoral joint, mean T1ρ values were compared between the 3 groups with multiple group comparisons and post hoc tests. T1ρ relaxation times were also correlated against measures of patellofemoral anatomy and alignment for single and multiple dislocations. Statistical significance was set at < .05.
RESULTS
T1ρ relaxation times were significantly longer for injured knees (single and multiple dislocations) than controls at the medial and central patella and central trochlear groove. For the regions on the patella, significant differences between injured and control knees exceeded 15%. No significant differences were identified between single and multiple dislocations. For the initial dislocation group, T1ρ relaxation times within multiple regions of the patellofemoral joint were significantly correlated with lateral patellar alignment or patellar height.
CONCLUSION
Elevated patellofemoral cartilage T1ρ relaxation times are consistent with a high risk of long-term patellofemoral osteoarthritis for adolescents who experience patellar dislocations. T1ρ relaxation times were elevated for multiple regions of patellofemoral cartilage. T1ρ relaxation times were expected to increase with additional dislocation episodes, but relaxation times after single and multiple dislocations were similar. After a first dislocation, parameters related to patellar maltracking were correlated with cartilage degradation.
Topics: Humans; Adolescent; Patellar Dislocation; Cross-Sectional Studies; Cartilage; Patellofemoral Joint; Patella; Osteoarthritis, Knee; Joint Dislocations; Bone Diseases; Magnetic Resonance Imaging
PubMed: 37897349
DOI: 10.1177/03635465231205562 -
Journal of Orthopaedic Research :... Apr 2023The role of patella height is discussed controversially in total knee arthroplasty (TKA). Therefore, this computational study aims to systematically analyze the...
The role of patella height is discussed controversially in total knee arthroplasty (TKA). Therefore, this computational study aims to systematically analyze the biomechanical effect of different patella heights on patellofemoral (PF) forces and kinematics after cruciate-retaining (CR) TKA. We implemented a CR bicondylar TKA with a dome patellar button in a validated dynamic musculoskeletal multibody model of a male human knee joint. Retropatellar dynamics (contact force [N], shear force [N], patellar shift [mm], tilt [°], and rotation [°]) were evaluated during dual-limb squat motion (flexion from 0° to 90°) with simulated active muscle forces and the effects of different patella heights (Blackburne-Peel [BP] ratio of 0.39, 0.49, 0.65, 0.85, 1.01, and 1.1 were systematically examined). As active knee flexion increased, PF contact force also increased. Patella alta (BP = 1.1) resulted in higher PF contact forces compared to normal patella height (BP = 0.65) by up to 16%. Contrarily, patella baja was associated with decreased PF forces by 7%. Compared to patella baja (BP = 0.39), patella alta (BP = 1.1) considerably increased the contact force by up to 25%. Different patellar heights mainly affected PF shear forces during early knee flexion. Concerning PF kinematics, patella alta (BP = 1.1) yielded a greater lateral tilt of more than 4° and higher patellar rotation by up to 3° during deep knee flexion, compared to normal patella height (BP = 0.65). Our computational study indicates that patella alta is associated with the highest PF contact and shear force after the implantation of a CR bicondylar TKA. This should be considered in PF disorders following TKA.
Topics: Male; Humans; Arthroplasty, Replacement, Knee; Patella; Biomechanical Phenomena; Patellofemoral Joint; Knee Joint; Bone Diseases; Range of Motion, Articular; Knee Prosthesis
PubMed: 35949157
DOI: 10.1002/jor.25425 -
Archives of Orthopaedic and Trauma... Jul 2022The incidence of patella fracture is statistically low (0.5-1.5%) compared to other fractures of the extremities [Patella fractures 76(10):987-997, 2005]. In the latter...
INTRODUCTION
The incidence of patella fracture is statistically low (0.5-1.5%) compared to other fractures of the extremities [Patella fractures 76(10):987-997, 2005]. In the latter research, patella fractures if treated surgically present an overall inferior functional outcome. Little is known about the influence of the postoperative patella height on the clinical outcome. Therefore, the aim of our study was to analyse the influence of the patella height on the patients' functional outcome after surgery.
METHODS
In this retrospective study the in-house trauma register of our level I University trauma center was screened for patients suffering patella fractures treated surgically. Patella height of the same patients was evaluated on lateral X-rays using the Insall-Salvati Ratio (ISR). The patients' X-rays were analyzed at two time points for the ISR, whereas group A presents ISR data right after surgery and group B data at the latest follow up (minimum 6 weeks). The change of mean ISR at both time points was tested for significance. The functional outcome was measured by the "Munich Knee Questionaire" (MKQ). These MKQ results of different patella heights and fracture types were compared.
RESULTS
The screening of our in-house trauma register revealed 375 patients between the years 2003 and 2016. Out of these 54 patients (34f, 20 m) were enrolled. In detail the follow-up time for ISR between group A and B accounted for a mean of 503.8 ± 655.7 days. The MKQ was assessed at a mean of 1367.0 ± 1042.8 days after surgery. According to the AO-classification 10% AO.34 type B and 90% AO.34 type C fractures were found. Group A showed in 9.1% a patella baja and in 27.3% a patella alta compared to group B presenting 20.0% patella baja and 14.5% patella alta. There was no significant difference in functional outcome referring to the MKQ in patella alta (MKQ 69.0% ± 18.2) or baja (MKQ 67.1% ± 17.9) (p = 0.9). No significant functional difference between AO34.type B (MKQ 74.5% ± 11.0) and AO34.type C fractures (MKQ 64.0% ± 15.0) resulted (p = 0.1).
CONCLUSION
Our results demonstrate that different postoperative patella heights apparently do not influence the functional outcome in the short follow-up.
Topics: Fractures, Bone; Humans; Knee Injuries; Knee Joint; Patella; Retrospective Studies; Treatment Outcome
PubMed: 33825039
DOI: 10.1007/s00402-021-03871-7 -
Journal of Orthopaedic Surgery and... Jul 2021The objectives of this study were to investigate the anatomic morphology of patellar ridge using computed tomography-based three-dimensional (3D) computer models and to...
BACKGROUND
The objectives of this study were to investigate the anatomic morphology of patellar ridge using computed tomography-based three-dimensional (3D) computer models and to assess the center of the patellar ridge after virtual resections.
METHODS
We selected 80 patients, 40 males (age, 33.2±6.8 years) and 40 females (age, 30.6±7.2 years), who were slightly symptomatic with soft tissue injury of the knee joint. The right or left knees were scanned by computed tomography (CT). The CT data of 160 knees was used to construct 3D computer models by image analysis software (Mimics). Variables such as the angle between the patellar ridge and patellar long axis, the distance between the center of the patellar ridge and the center of patellar cut after virtual resections were measured. We detect differences between the sides and genders with the 3D computer models by Student's t test. Simple linear regression and correlation test was used to correlate the patellar ridge center to the center of the patellar cut.
RESULTS
According to the available data, there were significant gender differences in the length and width of patellar cut after virtual resections even with strict control for the height and weight of the patients. The angle between the patellar ridge and the patellar long axis was 11.24° ± 3.62°. The angle in male patients was 10.17° ± 4.82°, and it was 12.28°± 3.78° in female patients. The morphological difference was statistically significant (P < 0.05). After using the subchondral method to virtually resect the patellae, with reference to the center of the patellar cut, the center of the patellar ridge lies superiorly and medially in 88.75%, inferiorly and medially in 8.75%, laterally and superiorly in 2.5%, and in no case laterally and inferiorly. The intra-observer reliability regarding the dimensional measurements was excellent in this study.
CONCLUSIONS
Advances in 3D computer models had resulted in the availability of preoperative measurement and virtual planning. The anthropometric dimensions of this study could provide general information for guiding surgical management of the patella in total knee arthroplasty (TKA) and were useful in designing patellar implants.
CLINICAL RELEVANCE
The placement of the patellar component during TKA differs from one patella to another. The anatomic morphology information of the patellar ridge is helpful for surgeons to perform patellar resurfacing in TKA.
Topics: Adult; Anatomic Landmarks; Arthroplasty, Replacement, Knee; Computer Simulation; Female; Humans; Imaging, Three-Dimensional; Male; Patella; Sex Factors; Tomography, X-Ray Computed
PubMed: 34229682
DOI: 10.1186/s13018-021-02587-z -
Developmental Dynamics : An Official... Jun 2020Cruciate ligament (CL) and patellar tendon (PT) are important elements of the knee joint, uniting femur, patella, and tibia into a single functional unit. So far,...
BACKGROUND
Cruciate ligament (CL) and patellar tendon (PT) are important elements of the knee joint, uniting femur, patella, and tibia into a single functional unit. So far, knowledge on the developmental mechanism of CL, PT, and patella falls far behind other skeletal tissues.
RESULTS
Here, employing various lineage tracing strategies we investigate the cellular sources and dynamics that drive CL, PT, and patella formation during mouse embryonic development. We show that Gdf5 and Gli1 are generally expressed in the same cell population that only contributes to CL, but not PT or patella development. In addition, Col2 is expressed in two independent cell populations before and after joint cavitation, where the former contributes to the CL and the dorsal part of the PT and the latter contributes to the patella. Moreover, Prrx1 is always expressed in CL and PT progenitors, but not patella progenitors where it is switched off after joint cavitation. Finally, we reveal that patella development employs different cellular dynamics before and after joint cavitation.
CONCLUSIONS
Our findings delineate the expression changes of several skeletogenesis-related genes before and after joint cavitation, and provide an indication on the cellular dynamics underlying ligament, tendon, and sesamoid bone formation during embryogenesis.
Topics: Animals; Female; Knee Joint; Mice; Patella; Patellar Ligament; Posterior Cruciate Ligament; Pregnancy; Tendons; Transcription Factors
PubMed: 32022343
DOI: 10.1002/dvdy.158 -
In Vivo (Athens, Greece) 2020Patella baja (PB) and pseudo-patella baja (PPB) have been shown to negatively influence outcomes after total knee arthroplasty. We hypothesized that there is a high...
BACKGROUND/AIM
Patella baja (PB) and pseudo-patella baja (PPB) have been shown to negatively influence outcomes after total knee arthroplasty. We hypothesized that there is a high incidence of PB and PPB after megaprosthetic total knee arthroplasty (M-TKA), and that this is associated with reduced range of motion.
PATIENTS AND METHODS
We retrospectively analysed all patients in our Orthopaedic Trauma Department after distal femur or proximal tibia replacement. Preoperative and one-year postoperative follow-up included measurement of range of motion and detection of PB and PPB using radiological indices.
RESULTS
We included 44 patients (age: 73±19 years). Preoperative PB detected by ISI could be reduced from 13 (36%) to 11 (25%) (p<0.01). Preoperative vs. postoperative ISI was 0.88±0.23 vs. 1.06±0.45 (p=0.03). PPB was observed preoperatively in 23 (63%) patients vs. 24 (54%) postoperatively. Preoperative vs. postoperative CDI was 0.70±0.24 vs. 0.95±0.43 (p=0.002). Preoperative flexion was 91°±30° vs. 85°±24° postoperatively (p>0.05).
CONCLUSION
Both PB and PPB are frequently observed after M-TKA. A reduction in PB and PPB alone does not improve postoperative range of motion.
Topics: Aged; Aged, 80 and over; Arthroplasty, Replacement, Knee; Female; Humans; Male; Patella; Postoperative Period; Range of Motion, Articular; Treatment Outcome
PubMed: 32354904
DOI: 10.21873/invivo.11887 -
Journal of Orthopaedic Research :... Mar 2023To determine the cross-sectional and longitudinal associations of patella alignment with cartilage relaxation and patients' self-reported symptoms. Thirty participants...
To determine the cross-sectional and longitudinal associations of patella alignment with cartilage relaxation and patients' self-reported symptoms. Thirty participants with isolated patellofemoral joint (PFJ) degeneration (six males, 53.7 ± 9.3 years) and 24 controls (12 males, 47.6 ± 10.7 years) were included. Magnetic resonance assessment was performed to provide grading of structural abnormalities, cartilage relaxation times, and patella alignment. Self-reported symptoms were assessed using the self-administrated knee injury and osteoarthritis outcome score (KOOS). All participants were examined at baseline and 3 years. Statistical parametric mapping and Pearson partial correlation were used to evaluate the associations between patella alignment with cartilage relaxation times and self-reported symptoms, respectively. The analyses were performed between baseline (cross-sectional) as well as the baseline against 3 years (longitudinal). Results indicated that patella height and patella flexion were associated with T and T relaxation times at baseline (percentages of voxels showing significant correlation [PSV] = 10.1%-24.8%; mean correlations [R] = 0.34-0.36; mean p = 0.015-0.026). Furthermore, greater patella lateral alignment, lateral tilt, and lateral spin were associated with longer T times at 3 years (PSV = 11.0%-14.4%, R = 0.39-0.44, p = 0.017-0.028). Last, a higher patella was associated with a lower KOOS at baseline and at 3 years (R = -0.33 to -0.35). The study suggests that patella malalignment is a risk factor for worsening cartilage health, informing clinicians of a better rehabilitation program that targets PFJ degeneration.
Topics: Male; Humans; Patella; Self Report; Cross-Sectional Studies; Patellofemoral Joint; Cartilage; Osteoarthritis, Knee; Magnetic Resonance Imaging; Bone Diseases; Cartilage, Articular; Knee Joint
PubMed: 35598282
DOI: 10.1002/jor.25384