Patellar Bone Research Articles

CORRELATION BETWEEN MORPHOMETRY OF PATELLAR LIGAMENT AND PATELLA-AN AID TO TOTAL KNEE ARTHROPLASTY

Background: Patellar ligament is of surgical importance in procedures pertaining to total knee arthroplasty. It is extensively used as an autogenous graft for endoscopic anterior cruciate ligament reconstruction. Patellar ligament is the most preferred autograft owing to sufcient load to failure strength and stiffness. Purpose of the study: Dimensions of patella have been shown to be of anthropometric importance and is also used for personal identication as the bone is resistant to postmortem changes. There is paucity of literature on studies correlating the dimensions of patellar ligament and patella bone in Indian population. This study is the rst of its kind to provide data on the same. 53 prosected lower limbs were used to study the morphome Material and Methods: try of Patellar ligament and Patella using digital vernier calipers. The mean length, width and thickness values of Patellar ligament and bone were recorded. Pearson correlation coefcient was used to test the strength of association between the two variables. It was seen that there was negative correlation between Results: patella length and ligament length and thickness. There was positive correlation between patella length and ligament width. Patella width correlated positively with ligament length and ligament width but negatively with ligament thickness. Patella thickness correlated negatively with ligament length and thickness but positively with ligament width. This Conclusion- study will provide valuable anthropometric data and aid the orthopaedic surgeons performing knee surgeries.

Novel press-fit technique of patellar bone plug in anterior cruciate ligament reconstruction is comparable to interference screw fixation.

Conventional press-fit technique for anterior cruciate ligament reconstruction (ACLR) is performed with extraction drilling of the femoral bone tunnel and manual shaping of the patellar bone plug. However, the disadvantages of this technique include variation in bone plug size and, thus, the strength of the press-fit fixation, bone loss with debris distribution within the knee joint, potential heat necrosis, and metal wear debris due to abrasion of the guide wire. To overcome these disadvantages, a novel technique involving punching of the femoral bone tunnel and standardized compression of the bone plug was introduced. In this study, the fixation strength and apparent stiffness were tested and compared to that of the gold-standard interference screw fixation technique in three flexion angle configurations (0°/45°/90°) in a porcine model. We hypothesized that the newly developed standardized press fit fixation would not be inferior to the gold standard method. Sixty skeletally mature porcine knees (30 pairs) were used. Full-thickness central third patellar tendon strips were harvested, including a patellar bone cylinder of 9.5mm in diameter. The specimens were randomly assigned to 10 pairs per loading angle (0°, 45°, 90°). One side of each pair was prepared with the press-fit technique, and the contra-lateral side was prepared with interference screw fixation. Equivalent numbers of left- and right-sided samples were used for both fixation systems. A three-way multifactor ANOVA was carried out to check for the influence of (a) fixation type, (b) flexion angle, and (c) side of the bone pair. The primary fixation strength of femoral press-fit graft fixation with punched tunnels and standardized bone plug compression did not differ significantly from that of interference screw fixation (p = 0.51), which had mean loads to failure of 422.4 ± 134.6N and 445.4 ± 135.8N, respectively. The flexion angle had a significant influence on the maximal load to failure (p = 0.01). Load values were highest in 45° flexion for both fixations. The anatomical side R/L was not a statistically significant factor (p = 0.79). The primary fixation strength of femoral press-fit graft fixation with punched femoral tunnels and standardized bone plug compression is equivalent to that of interference screw fixation in a porcine model. Therefore, the procedure represents an effective method for ACL reconstruction with patellar or quadriceps tendon autografts including a patellar bone plug.

Transpatellar bone tunnels perforating the lateral or anterior cortex increase the risk of patellar fracture in MPFL reconstruction: a finite element analysis and survey of the International Patellofemoral Study Group.

(1) To determine applied patellar drilling techniques for medial patellofemoral ligament (MPFL) reconstruction among members of the International Patellofemoral Study Group (IPSG) and (2) to evaluate the risk of patellar fracture for various patellar bone tunnel locations based on a finite element analysis (FEA) model. In the first part of the study, an online survey on current MPFL reconstruction techniques was conducted among members of the IPSG. In the second part of the study, a three-dimensional FEA model of a healthy knee joint was created using a computed tomography scan. Patient-specific bone density was integrated into the patella, and cartilage of 3mm thickness was modeled for the patellofemoral joint. According to the survey's results, two different types of patellar bone tunnels (bone socket and transpatellar bone tunnel) were simulated. The risk of patellar fracture was evaluated based on the fracture risk volume (FRV) obtained from the FEA. Finite element analysis revealed that subchondral bone socket tunnel placement is associated with the lowest FRV but increased with an anterior offset (1-5mm). Transpatellar bone tunnels violating the lateral or anterior cortex showed a higher FRV compared to bone socket, with the highest values observed when the anterior cortex was penetrated. Violation of the anterior or lateral patellar cortex using transpatellar bone tunnels increased FRV compared to a subchondral patellar bone socket tunnel. In MPFL reconstruction, subchondral patellar bone socket tunnels should be considered for patellar graft fixation to avoid the risk of postoperative patellar fracture. Survey; Descriptive laboratory study/Level V.

Prediction of quadriceps tendon-patellar bone autograft diameter in adolescents with 2-dimensional magnetic resonance imaging and anthropometric measures.

This study evaluates the correlation between the bone end and soft tissue end of the quadriceps tendon-patellar bone autograft (QPA) size and pre-operative MRI measurements of the quadriceps tendon along sections to be included in the graft harvest in adolescents. We also assessed association between graft diameter and anthropometric measures (height, weight, and BMI), age, and sex. Patients (10-18years) who underwent QPA ACL reconstruction and had a pre-operative MRI were considered for inclusion. Age, height, and weight, tibial and femoral side graft diameter, and patellar bone block dimensions were collected. Using a pre-operative 2D sagittal plane MRI, we measured the quadriceps at 10-mm increments above the patella, up to 40mm. We assessed correlation between the bone-end graft diameter and the AP measure at 10mm above the patella, and correlation between the soft-tissue end graft diameter and the most proximal AP measure. A total of 103 patients were included. A significant correlation between the soft-tissue side graft diameter and most proximal AP measurement was observed (rs = 0.51; p < 0.001). However, measurements significantly underestimated the soft-tissue end graft diameter (9.6 ± 0.8 vs. 7.4 ± 1.1; p < 0.001). There was no correlation between the bone-end graft diameter and AP measurement 10mm above the patella. Anthropometric measures were not associated with graft size. Skeletal maturity was associated with smaller graft size (p = 0.08). Soft-tissue end graft diameter is associated with the AP measure of the quadriceps at 20-40mm above the superior pole of the patella.

Surgical management of arthroscopic anterior cruciate ligament reconstruction using quadruple hamstring graft and assessment of its fuctional outcome

The knee joint is one of the most commonly injured joint in our body and the most commonly injured ligament is ACL. Due to ever increasing RTA’s and increased participation in sporting activities. There is increase in incidence of ligament injuries of knee. The ACL along with other ligaments, capsule is the primary stabilizer of knee and prevent anterior translation and restricts valgus and rotational stress to certain degree. Open reconstruction of ACL which was done earlier is not practiced now a day due to complications such as increased Post-operative pain, stiffness and lengthy rehabilitation phase. Arthroscopic reconstruction of the injured ACL has become the gold standard procedure. The ideal graft for ACL is still a topic of debate. The most commonly used graft are bone patellar tendon bone graft and hamstring graft. The hamstring graft is increasingly used now a day for the following reasons: . Advanced soft tissue fixation technique . Increased incidence of anterior knee pain with bone patellar tendon bone graft This study has been done to evaluate the functional outcome of arthroscopic single bundle anterior cruciate ligament reconstruction using quadrupled hamstring tendon (Gracilis and semitendinosus) autograft in anterior cruciate injuries.Methods: Twenty cases of arthroscopic anterior cruciate ligament reconstruction were regularly followed for an average period of 17.6 months in mamta medical college, Khammam from august 2019 to march 2021. Results: Among twenty patients treated with arthroscopic anterior cruciate ligament reconstruction 45% (9 patients) had excellent functional outcome while 40% (8 patients) had good functional outcome and remaining 15% (3 patients) had fair outcome according to LYSHOLM KNEE SCORE. One patient had superficial infection at the donor site which settled with intravenous antibiotics. One patient developed deep infection of the donor site with wound gaping which is managed with wound debridement and secondary closure and was given intravenous antibiotics which is healed well and the sutures removed after 10 days. One patient developed fixed flexion deformity of 10 degree with range of movements ranging from 10 to 90 degree. The patient had poor compliance to rehabilitation protocol. The mean pre-operative IKDC (international knee documentation 2000 score) score was 50.86 while the mean post-operative score was 87.66. there was significant improvement in post-operative IKDC score compared with pre-operative score with P value

Comparison of Doubled Semitendinosus and Gracilis Autograft Versus Bone-Patellar Tendon-Bone Autograft for Reconstruction of the Anterior Cruciate Ligament

Background: The choice of graft for anterior cruciate ligament (ACL) reconstruction is a matter of debate with hamstring and bone-patellar tendon-bone being the most popular autologous graft options. Objective: The objective of this study was to conduct a prospective randomized control trial comparing doubled semitendinosus and gracilis graft versus bone-patellar tendon-bone graft. Materials and Methods: Sixty patients with chronic unilateral rupture of ACL underwent arthroscopically assisted ACL reconstruction using quadrupled hamstring and bone-tendon-bone graft after randomization. Both groups were comparable with demographic data, preoperative activity level, mechanism of injury, the interval between injury and operation, and preoperative laxity of the knee. The same well-proved surgical technique and aggressive rehabilitation were used in all cases. The outcome assessment was done using the visual analog scale, Lysholm score, Tegner activity level, and International Knee Documentation Committee (IKDC) evaluation system. Results: At 2-year follow-up, we found that results within the same groups showed statistically significant improvement as assessed by IKDC, Tegner’s, and Lysholm operative scores. There was also a significant correlation between the manual Lachman test and stress laxometry findings. There was no statistically significant difference between the scores of the two groups (hamstring and bone patella tendon). In the hamstring group, we recorded a higher incidence of femoral tunnel widening, and in the bone-patellar tendon-bone group the higher incidence of kneeling discomfort and increased area of decreased sensation in the skin. Conclusions: Arthroscopic ACL reconstruction by either hamstring tendon graft or bone-patellar tendon-bone graft gives equally satisfactory results.

Transosseous Tie Fixation Using Krackow Sutures and Bone Tunnels in a Comminuted Fracture of the Upper Pole of the Patella: A Case Report

Comminuted fractures of the patella mostly occur at the inferior pole and require appropriate reduction and fixation to restore the extensor mechanism. Conventional methods such as tension-band wiring are not enough to gain proper fixation strength. Numerous methods have been reported, including circumferential cerclage wiring, osteosynthesis, and suture anchors depending on the fracture pattern. Herein, the author reports a relatively rare case of a comminuted fracture of the upper pole of the patella, for which we used augmented Krackow sutures in the quadriceps and fixation with tying of the suture limbs through patellar bone tunnels. Satisfactory results were obtained in terms of reduction and extensor mechanism recovery.

Anterior Cruciate Ligament Reconstruction with Quadriceps Tendon–Patellar Bone Autograft and Dual Tibial Fixation

Anterior cruciate ligament ruptures are a relatively common injury in the athletic population, and surgical reconstruction is often indicated to restore knee stability. While hamstring tendon and patellar bone–tendon–bone autografts are a well-established graft choice in this population, there has been a growing body of literature supporting the benefits of quadriceps tendon autograft. Our technique illustrates a full-thickness quadriceps tendon–patellar bone autograft with dual tibial fixation using an interference screw and backup suspensory anchor fixation.

Evaluation of ACL Graft Remodeling and Prediction of Graft Insufficiency in Sequenced MRI—Two-Year Follow-Up

Background: Postoperative magnetic resonance imaging (MRI) evaluation of anterior cruciate ligament (ACL) graft maturity is a useful and practical tool that allows for assessment of graft status and remodeling stage. The purpose of this study was to evaluate and compare previously described methods of graft evaluation in MRI. We identify factors influencing the maturation and correlating graft appearance in MRI with indirect symptoms of graft insufficiency to identify patients at risk. Methods: Retrospective evaluation was performed in 44 patients who received bone patellar tendon bone (BPTB) ACL reconstruction with nine consecutive postoperative MRIs at 2, 6, 12, 18, 24, 36, 48, 72, and 96 weeks. Graft status was evaluated using signal-to-noise quotient (SNQ) methods in both sagittal and axial planes. We also assessed the homogeneity of the graft by standard deviation (SD) of signal intensity. SNQ was correlated with patient’s age, sex, postoperative weight-bearing, as well as indirect signs of graft insufficiency by MRI including graft appearance, posterior cruciate ligament (PCL) buckling, and measurement of anterior tibia subluxation. Results: We observed that the results of modelling SNQs from both sagittal and axial planes were similar. For both SNQs, the change over weeks quotient was nonlinear where the clinical parameter increased at week 36 and subsequently decreased. The SNQ at week 96 does not reach the levels from week 2. We observed that the model incorporating SNQ and relative SD (rSD) in the sagittal plane predicted the tibia anterior subluxation proportions better than the model with clinical parameters measured in the axial plane. Our results demonstrate that greater SD is associated with less graft homogeneity, which could indicate that this model is a good predictor of graft insufficiency. In addition, the proportion of PCL buckling increased over the course of the study. Conclusions: MRI graft evaluation is very useful for assessing graft ligamentization stage and to predict graft insufficiency.

Long-term Outcomes of Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon-Patellar Bone Autograft.

Background:To date, there have been few studies on the outcomes of anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon–patellar bone (QTPB) autograft.Purpose:To evaluate the long-term clinical outcomes of ACLR using QTPB autograft.Study Design:Case series; Level of evidence, 4.Methods:We retrospectively reviewed 139 patients who underwent primary ACLR with QTPB autografts and had at least 7 years of postoperative follow-up data. Instability, clinical scores, donor-site morbidity, radiographic progression of osteoarthritis, and any associated complications were assessed.Results:The proportion of knees classified as grade >1 on the anterior drawer, Lachman, and pivot-shift tests decreased significantly postsurgically (from 47.4% to 5.0%, 48.9% to 4.3%, and 53.3% to 5.0%, respectively; P < .001 for all). The mean clinical scores at the final follow-up were 89.8, 81.0, and 4.4 for the Lysholm, International Knee Documentation Committee, and Tegner Activity Scale, respectively. The results of the Cybex II dynamometer isokinetic test showed decreases in flexion and extension strength at both 60° and 180° per second, which persisted until the final follow-up visit. About one-fifth (19.4%) of the patients had osteoarthritis (Kellgren-Lawrence grade ≥1) before surgery, which increased to 33.8% at the final follow-up. The overall complication rate was 23.2%, and about one-third of the patients who experienced complications underwent revision surgery as a result of graft rupture and residual instability.Conclusion:In the current study, ACLR using QTPB autograft provided satisfactory long-term clinical results, with acceptable rates of complication and donor-site morbidity.

Stacked Biocomposite Screws in a Single-Stage Revision Anterior Cruciate Ligament Reconstruction Has Acceptable Fixation Strength in a Porcine Cadaveric Model

Background: Stacked screws is a commonly used technique in single-stage revision anterior cruciate ligament (ACL) reconstruction in the setting of bone loss, but there are limited data to support its use. Hypothesis: Two configurations of a biocomposite stacked screws construct have similar fixation strength and linear stiffness as a primary ACL reconstruction construct in a biomechanical model. Study Design: Controlled laboratory study. Methods: A total of 30 porcine legs were divided into 3 groups. Group 1 underwent primary ACL reconstruction with a patellar tendon graft fixed into the femur, with an 8-mm biocomposite interference screw of beta-tricalcium phosphate and poly lactide-co-glycolide. For a revision ACL reconstruction model, groups 2 and 3 had bone tunnels created and subsequently filled with 12-mm biocomposite screws. New bone tunnels were drilled through the filler screw and the surrounding bone, and the patellar bone plug was inserted. Group 2 was fixed with 8-mm biocomposite screws on the side of the graft opposite the filler screw, while group 3 had the interference screw interposed between the graft and the filler screw. The construct was loaded at 1.5 mm/s in line with the tunnel until failure. Load to failure, linear stiffness, and mode of failure were recorded. Results: The mean pullout strength for groups 1, 2, and 3 was 626 ± 145 N, 653 ± 152 N, and 720 ± 125 N, respectively (P = .328). The mean linear stiffness of the construct in groups 1, 2, and 3 was 71.4 ± 9.9 N/mm, 84.1 ± 11.1 N/mm, and 82.0 ± 10.8 N/mm, respectively. Group 2 was significantly stiffer than group 1 (P = .037). Conclusion: Two configurations of a biocomposite stacked screws construct for a single-stage revision ACL reconstruction in the setting of bone loss show a similar fixation strength and linear stiffness to a primary ACL reconstruction at time zero in a porcine model. Clinical Relevance: In the setting of bone loss from tunnel malpositioning, a single-stage revision ACL reconstruction using a stacked screws construct may provide adequate fixation strength and linear stiffness.

Anatomic single vs. double-bundle ACL reconstruction: a randomized clinical trial\u2013Part 1: clinical outcomes

PurposeCompare clinical outcomes of anatomic single-bundle (SB) to anatomic double-bundle (DB) anterior cruciate ligament reconstruction (ACLR). It was hypothesized that anatomic DB ACLR would result in better International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) scores and reduced anterior and rotatory laxity compared to SB ACLR.MethodsActive individuals between 14 and 50 years of age that presented within 12 months of injury were eligible to participate. Individuals with prior injury or surgery of either knee, greater than a grade 1 concomitant knee ligament injury, or ACL insertion sites less than 14 mm or greater than 18 mm were excluded. Subjects were randomized to undergo SB or DB ACLR with a 10 mm-wide quadriceps tendon autograft harvested with a patellar bone block and were followed for 24 months. The primary outcome measures included the IKDC-SKF and KT-1000 (side to side difference) and pivot shift tests. Other secondary outcomes included measures of sports activity and participation, range of motion (ROM) and re-injury.ResultsEnrollment in the study was suspended due to patellar fractures related to harvest of the patellar bone plug. At that time, 57 subjects had been randomized (29 DB) and two-year follow-up was attained from 51 (89.5%). At 24-month follow-up there were no between-group differences detected for the primary outcomes. Twenty-one (77.8%) DB’s and 20 (83.3%) SB’s reported returning to pre-injury sports 2 years after surgery (n.s) Three subjects (2 DB’s, 5.3% of total) sustained a graft rupture and 5 individuals (4 SB’s, 8.8% of total) had a subsequent meniscus injury.ConclusionsDue to the early termination of the study, there were no detectable differences in clinical outcome between anatomic SB and DB ACLR when performed with a quadriceps tendon autograft with a bone block in individuals with ACL insertion sites that range from 14 to 18 mm.Level of EvidenceLevel 2

EVALUATION OF ARTHROSCOPIC ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING BONE-PATELLAR TENDON-BONE GRAFT

AIM- Anterior cruciate ligament (ACL) is most common injured ligament in the knee joint. Surgical management of ACL rupture is technically demanding as improper reconstruction can lead to an unstable joint. The aim of present study was to nd out the outcome of Arthroscopic reconstruction of ACLusing Bone patellar tendon bone (BPTB) graft. METHOD – It is a retrospective observational study where arthroscopic reconstruction of ACLwas done over a period of 5 years. IKDC score was applied to nd out the outcome of surgery. Strict post operative rehabilitation regime was followed. RESULT- After evaluation of 25 cases, 60% (15cases) showed very good outcome, 36%(9 cases) showed good outcome and 4% (1 case) showed poor outcome. Implant related local irritation is seen in 2 patients and low grade infection was seen in 1 patient. CONCLUSION – Majority of the patients were satised with the result so it is purposeful to perform ACL reconstruction arthroscopically using BPTB graft.

Psychological, physical and social factors influence decision to return to sport after revision ACL reconstruction with BPTB graft.

There is limited evidence in literature regarding the patient-reported factors that influence their return to sport (RTS) in revision anterior cruciate ligament reconstruction (ACLR). The medium-term results of a prospective consecutive cohort of patients undergoing single- and two-stage revision ACLR with bone patellar tendon bone graft (BPTB) and patient-reported factors that influence their decision to return to sport are presented in this study. Seventy-two patients were included in this prospective study. Single- or two-stage revision with BPTB graft was performed based on pre-operative planning. Iliac crest bone graft was used. Pre-operative and follow-up Lysholm and Tegner activity scores and RTS, level of sport and patient-reported factors affecting RTS were recorded. The mean follow-up was 9years (SD 2.7years). Single-stage revision ACLR was performed in 61 patients. In 11 patients (15%), revision ACLR was performed in two stages. There was a significant improvement in Lysholm score from mean 51.1 to 86.7 (p < 0.001). The incidence of re-rupture in this cohort was 0%. The median Tegner score was 6 (range 2-9). Twenty-five patients (34.7%) did not return to anysport at final follow-up. Twenty-nine (40.2%) patients returned to their pre-injury level of sport. Fear of reinjury (79%, p < 0.001) and persistent knee symptoms (35.8%, p = 0.03) were the most common factors limiting RTS in non-returners. Psychological and social factors may have an influence on RTS in addition to physical factors. Level III.

Patellofemoral pain patients show differences in 3D patellar shape compared to healthy control subjects

Purpose: Alterations in bone shape are not only associated with the presence of radiographic OA, they are predictive of tibiofemoral OA onset and have even been proposed as a biomarker for tibiofemoral OA progression. Such biomarkers for early OA detection and progression are essential in the developing successful and early OA interventions. There is evidence suggesting patellofemoral pain (PFP) is a precursor for developing patellofemoral osteoarthritis (PFOA) and that it is associated with altered bone shape. As such, alterations in patellofemoral bone shape may also be a promising biomarker in patients with PFP and may offer an opportunity for early therapeutic intervention for OA, potentially even before its onset. Therefore, the purpose of this study is to quantitatively define differences in 3D patellar shape between patients with PFP and healthy controls, using statistical shape modeling (SSM). Additionally, we studies if 3D shape variations in the patella are associated with the presence of structural abnormalities in the patellofemoral joint. Methods: Data from 62 PFP and 69 matched control subjects (age: 23.5±7.1 & 23.1±5.9 years, Table 1) comprised the study’s two cohorts. We used 3D magnetic resonance images of the knee and a semi-automatic segmentation algorithm to create 3D models of the patella. The resulting 3D statistical shape model included 25 shape modes after a parallel analysis was used to discard noise. Logistic regression analyses, with adjustment for age, BMI, and sex were applied to test the association between independent shape modes and group status. For the secondary analysis, logistic regression was used to test the association between MOAKS features (patellar osteophytes, patellar bone marrow lesions, patellar minor cartilage defects, anterior femoral osteophytes, anterior femoral bone marrow lesions, and Hoffa synovitis) and the independent shape modes, adjusted for age, sex, BMI and group status. Results are expressed using odds ratios (OR) with accompanying 95% confidence intervals. Results: Only modes 16 and 22 showed significant associations with the presence of PFP (OR 0.66 with p=0.025 and OR 1.56 with p=0.036, Figure 1). These modes described a variance within the population of 1.42% and 0.87%. Statistical analyses showed multiple associations between patellar shape modes and 5 out of our 6 tested MOAKS features. Shape modes 1, 6, 9, 10, 12, and 23 were associated with the presence of minor cartilage defects on the patella. Furthermore, mode 6 was associated with patellar bone marrow lesions, mode 9 was associated with osteophytes on the anterior femur while mode 3 was associated with bone marrow lesions in the anterior femur. Hoffa synovitis was associated with modes 5, 11, 12, and 24. Conclusions: Our study is the first to demonstrate that not only are 3D shape patterns altered in patients with PFP, similar to patients with OA, but that patellar shape variations in this young population are associated with the presence of structural abnormalities linked to OA. Specifically, mode 16 shows a rounder shape at the lateral side and apex of the patella of patients with PFP, while a pointier shape is seen in healthy controls. Mode 22 shows a more diagonal base of the patella in patients with PFP while in control subjects a more horizontal patellar base was observed. The association between changes in shape and markers of OA (especially minor cartilage defects and Hoffa synovitis) in this young population indicates that 3D SSM can be used to create shape biomarkers that likely indicate the earliest stages of OA.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Biconvex Patellar Components: 96% Durability at 10 Years in 262 Revision Total Knee Arthroplasties.

The optimal strategy to address osseous deficiencies of the patella during revision total knee arthroplasty (TKA) remains controversial. One possible solution is a cemented biconvex patellar component used such that the non-articular convexity both improves fixation and makes up for bone loss. The aim of this study was to determine the outcomes of the use of biconvex patellar components in a large series of revision TKAs. From 1996 to 2014, 262 revision TKAs were performed at a single institution using a biconvex patellar component. Implant survivorship, clinical and radiographic results, and complications were assessed. The mean patient age at the TKA revision was 69 years, and 53% of the patients were female. The mean follow-up was 7 years. The 10-year survivorship free of revision of the biconvex patellar component due to aseptic loosening was 96%. The 10-year survivorship free of any revision of the biconvex patellar component was 87%. The 10-year survivorship free of any rerevision and free of any reoperation was 75% and 70%, respectively. The mean Knee Society Score (KSS) improved from 45.4 before the index revision to 67.7 after it. The mean residual composite thickness seen on the most recent radiographs was 18.1 mm. In addition to the complications leading to revision, the most common complications were periprosthetic patellar fracture (6%), of which 3 required revision; superficial wound infection (6%) requiring antibiotic therapy only or irrigation and debridement; and arthrofibrosis (3%). In this cohort of 262 revision TKAs, biconvex patellar components used to treat marked patellar bone loss demonstrated excellent durability with a 10-year survivorship free of patellar rerevision due to aseptic loosening of 96%. The biconvex patellar components were reliable as evidenced by substantial improvements in clinical outcomes scores and a low risk of complications. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Prenatal blood lead levels and reduced preadolescent glomerular filtration rate: Modification by body mass index

BackgroundFor the developing kidney, the prenatal period may represent a critical window of vulnerability to environmental insults resulting in permanent nephron loss. Given that the majority of nephron formation is complete in the 3rd trimester, we set out to test whether 1) prenatal lead exposure is associated with decreased preadolescent kidney function and 2) whether preadolescent obesity acts synergistically with early life lead exposure to reduce kidney function. MethodsOur study included 453 mother–child pairs participating in the PROGRESS birth cohort. We assessed prenatal blood lead levels (BLLs) in samples collected in the 2nd and 3rd trimesters and at delivery, as well as tibial and patellar bone lead measures assessed one-month postpartum. Preadolescent estimated glomerular filtration rate (eGFR) was derived from serum levels of creatinine and/or cystatin C measured at age 8–12 years. We applied linear regression to assess the relationship between prenatal bone and BLL with preadolescent eGFR, and adjusted for covariates including age, sex, BMI z-score, indoor tobacco smoke exposure, and socioeconomic status. We also examined sex-specific associations and tested for effect modification by BMI status. ResultsWe observed null associations between prenatal lead exposure and eGFR. However, in interaction analyses we found that among overweight children, there was an inverse association between BLL (assessed at 2nd and 3rd trimester and at delivery) and preadolescent eGFR. For example, among overweight participants, a one ln-unit increase in 2nd trimester BLL was associated with a 10.5 unit decrease in cystatin C-based eGFR (95% CI: −18.1, −2.8; p = 0.008). Regardless of lead exposure, we also observed null relationships between BMI z-score and eGFR overall, as well as among overweight participants. However, among participants with preadolescent obesity, we observed a significant 5.9-unit decrease in eGFR. We observed no evidence of sex-specific effects. ConclusionsOur findings, if confirmed in other studies, suggest a complex interplay between the combined adverse effects of adiposity and perinatal lead exposure as they relate to adolescent kidney function. Future studies will assess kidney function and adiposity trajectories through adolescence to better understand environmental risk factors for kidney function decline.

Anatomic single- and double-bundle ACL reconstruction both restore dynamic knee function: a randomized clinical trial\u2014part II: knee kinematics

PurposeCompare side-to-side differences for knee kinematics between anatomic single-bundle (SB) and anatomic double-bundle (DB) ACLR during downhill running at 6 and 24 months post ACLR using high-accuracy dynamic stereo X-ray imaging. It was hypothesized that anatomic DB ACLR would better restore tibio-femoral kinematics compared to SB ACLR, based on comparison to the contralateral, uninjured knee.MethodsActive individuals between 14 and 50 years of age that presented within 12 months of injury were eligible to participate. Individuals with prior injury or surgery of either knee, greater than a grade 1 concomitant knee ligament injury, or ACL insertion sites less than 14 mm or greater than 18 mm were excluded. Subjects were randomized to undergo SB or DB ACLR with a 10 mm-wide quadriceps tendon autograft harvested with a patellar bone block and were followed for 24 months. Dynamic knee function was assessed during treadmill downhill running using a dynamic stereo X-ray tracking system at 6 and 24 months after surgery. Three-dimensional tibio-femoral kinematics were calculated and compared between limbs (ACLR and uninjured contralateral) at each time point.ResultsFifty-seven subjects were randomized (29 DB) and 2-year follow-up was attained from 51 (89.5%). No significant differences were found between SB and DB anatomic ACLR for any of the primary kinematic variables.ConclusionsContrary to the study hypothesis, double-bundle reconstruction did not show superior kinematic outcomes compared to the single-bundle ACLR. While neither procedure fully restored normal knee kinematics, both anatomic reconstructions were similarly effective for restoring near-normal dynamic knee function. The findings of this study indicate both SB and DB techniques can be used for patients with average size ACL insertion sites.Level of evidenceLevel I

Evolution in ACL Autograft Harvesting Techniques: Transition to Minimally Invasive Autograft Harvesting.

Surgical techniques for anterior cruciate ligament (ACL) reconstruction continue to evolve. Harvesting techniques for commonly used ACL autografts such as bone patellar tendon bone, hamstring, and quadriceps tendon have similarly continued to progress. Traditional larger incisions for graft harvesting that were described in the 1980s have given way to smaller or more minimally invasive techniques. Advantages of these techniques are primarily anatomy based and include the following: decreased nerve complaints such as hypoesthesia or dysesthesia, improved cosmesis, decreased surgical site pain or morbidity, and, in the case of hamstring harvesting, easier tendon identification. The current literature supports reproducible minimally invasive or modified graft harvesting techniques for bone patellar tendon bone, hamstring, and quadriceps tendon autografts. Specialized instrumentation is available to simplify the harvesting process. Each of these techniques is described in detail outlining surgical steps, technical considerations, and precautions. Knowledge and review of these techniques provides the surgeon with greater flexibility and options when choosing and harvesting autograft tissue for ACL reconstruction.

Peroneus Longus Tendon Autograft for Anterior Cruciate Ligament Reconstruction: A Safe and Effective Alternative in Nonathletic Patients.

Introduction:Anterior cruciate ligament (ACL) is a common injury which has been conventionally managed by various graft reconstruction using bone patellar tendon bone, or quadruple hamstring autograft, to name a few. However, all these grafts are associated with many complications. Lately, peroneus longus tendon (PLT) autograft has shown promising results in this field, although there is still a dearth of data on its use. We, therefore, aimed at carrying out a study to evaluate the functional outcome and knee stability results of ACL reconstruction using PLT graft.Patients and Methods:Patients with a completely torn ACL were included in the study. The PLT was harvested, and graft length, thickness, and harvesting time were noted intraoperatively. Knee stability and functional scores were evaluated clinically and using Lachman test (primarily) and KT-2000 arthrometer and subjectively with International Knee Documentation Committee (IKDC) score at 6, 12, and 24 months (secondary outcome) postoperatively. Ankle scores were also recorded by making use of American Orthopedic Foot and Ankle Score (AOFAS)–Hindfoot Scale.Results:Forty-eight patients met the inclusion criteria. The graft harvest time was 7.4 min (5–9 min). The mean thickness of the graft on doubling was 7.9 mm (7–9 mm). Ninety-six percent of the patients were satisfied with their results of the knee surgery, and 95% of the patients had no complaints of ankle joint. The mean IKDC score postoperatively was 78.16 ± 6.23, and the mean AOFAS score was 98.4 ± 4.1. None of the patients had any neurovascular deficit.Conclusion:ACL reconstruction using PLT graft yields a good functional score (IKDC, KT-2000 arthrometer) even at 2-year follow-up. It is a safe and effective autograft option for ACL reconstruction.