Knee

Latest journal articles about knee arthroplasty and reconstruction from Journal of Arthroplasty, Knee Surgery, Sports Traumatology, Arthroscopy, Knee, The Bone & Joint Journal, Journal of Bone and Joint Surgery, Clinical Orthopaedics and Related Research, Acta Orthopaedica, Orthopedic Clinics of North, America, Journal of Orthopaedic Surgery and Research, Orthopedics

Related Articles The effect of a biphasic injectable bone substitute on the interface strength in a rabbit knee prosthesis model. J Orthop Surg Res. 2013 Jul 31;8(1):25 Authors: Zampelis V, Tägil M, Lidgren L, Isaksson H, Atroshi I, Wang JS Abstract BACKGROUND: In joint prosthetic surgery, various methods are used to provide implant stability. We used an injectable bone substitute, composed of calcium sulfate/hydroxyapatite, as bone defect filler to stabilize a tibia prosthesis in an experimental rabbit model. The aim of the study was to investigate and compare the stability of prosthetic fixation with and without the use of an injectable bone substitute. METHODS: Sixteen rabbits were used and the tibia prostheses were implanted bilaterally, one side with the prosthesis alone and the other side with the prosthesis and calcium sulfate/hydroxyapatite (CeramentTM). The rabbits were randomly divided into two groups and euthanized after 6 and 12 weeks, respectively. The prosthesis was extracted measuring the pull-out force in an Instron tester, and the bone surrounding the former prosthesis site was analyzed by histology, histomorphometry, and micro-computed tomography. RESULTS: At 6 weeks no difference in maximum pull-out force was found between the prostheses fixed with or without CeramentTM. At 12 weeks the maximum pull-out force for the prostheses with CeramentTM was significantly higher than that for the prostheses without CeramentTM (p = 0.04). The

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Related Articles Trends in the surgical treatment of articular cartilage defects of the knee in the United States. Knee Surg Sports Traumatol Arthrosc. 2013 Jul 30; Authors: Montgomery SR, Foster BD, Ngo SS, Terrell RD, Wang JC, Petrigliano FA, McAllister DR Abstract PURPOSE: The purpose of this study was to evaluate trends in surgical treatment of articular cartilage defects of the knee in the United States. METHODS: The current procedural terminology (CPT) billing codes of patients undergoing articular cartilage procedures of the knee were searched using the PearlDiver Patient Record Database, a national database of insurance billing records. The CPT codes for chondroplasty, microfracture, osteochondral autograft, osteochondral allograft, and autologous chondrocyte implantation (ACI) were searched.

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Related Articles Causes of Instability After Total Knee Arthroplasty. J Arthroplasty. 2013 Jul 26; Authors: Song SJ, Detch RC, Maloney WJ, Goodman SB, Huddleston JI Abstract The purpose of the present study was to characterize the underlying causes that lead to instability after total knee arthroplasty (TKA). We reviewed 83 revision TKAs (79 patients) performed for instability. After detailed analysis of patient's history, physical examination, operative report and radiographs, we identified six categories: flexion/extension gap mismatch, component malposition, isolated ligament insufficiency, extensor mechanism insufficiency, component loosening, and global instability. Twenty-five knees presented with multi-factorial instability. When these knees were classified according to the most fundamental category, each category above included 24, 12, 11, 10, 10 and 16 knees respectively. The unstable TKA may result from a variety of distinct etiologies which must be identified and treated at the time of revision. The revision TKA could be tailored to the specific causes. PMID: 23896358 [PubMed - as supplied by publisher]Read more... http://www.ncbi.nlm.nih.gov/pubmed/23896358?dopt=Abstract

Related Articles Amount of Torque and Duration of Stretching Affects Correction of Knee Contracture in a Rat Model of Spinal Cord Injury. Clin Orthop Relat Res. 2013 Jul 27; Authors: Moriyama H, Tobimatsu Y, Ozawa J, Kito N, Tanaka R Abstract BACKGROUND: Joint contractures are a common complication of many neurologic conditions, and stretching often is advocated to prevent and treat these contractures. However, the magnitude and duration of the stretching done in practice usually are guided by subjective clinical impressions. QUESTIONS/PURPOSES: Using an established T8 spinal cord injury rat model of knee contracture, we sought to determine what combination of static or intermittent stretching, varied by magnitude (high or low) and duration (long or short), leads to the best (1) improvement in the limitation in ROM; (2) restoration of the muscular and articular factors leading to contractures; and (3) prevention and treatment of contracture-associated histologic alterations of joint capsule and articular cartilage.

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Related Articles Abnormal Axial Rotations in TKA Contribute to Reduced Weightbearing Flexion. Clin Orthop Relat Res. 2013 Jul 27; Authors: Meccia B, Komistek RD, Mahfouz M, Dennis D Abstract BACKGROUND: Previous in vivo fluoroscopy studies have documented that axial rotation for patients having a TKA was significantly less than those having a normal knee. In fact, many subjects having a TKA experience a reverse axial rotation pattern where the femur internally rotates with increasing flexion. However, no previous studies have been conducted to determine if this reverse axial rotation pattern affects TKA performance. QUESTIONS/PURPOSES: The purposes of this study were: (1) Do normal and reverse axial rotation patterns of a TKA affect the maximum flexion angle postoperatively? (2) Does the axial rotation angle of the knee at maximum flexion during weightbearing impact the magnitude of the maximum flexion achieved in weightbearing? METHODS: One hundred twenty patients having TKA, previously analyzed under in vivo conditions using fluoroscopy and a three-dimensional model-fitting software package, were further evaluated to determine if reverse axial rotation patterns limit weightbearing TKA flexion. In this retrospective cohort, we identified 58 patients who had a normal axial rotation pattern (greater than 15° normal rotation). Sixty-two patients experienced greater than 3° of reverse axial rotation, defined as internal rotation of the femur

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Related Articles Rediscovering the history of orthopedics. Knee Surg Sports Traumatol Arthrosc. 2013 Jul 28; Authors: Marcacci M, Di Matteo B, Filardo G, Tarabella V PMID: 23892472 [PubMed - as supplied by publisher]Read more... http://www.ncbi.nlm.nih.gov/pubmed/23892472?dopt=Abstract

Related Articles Comparison of double-bundle anterior cruciate ligament (ACL) reconstruction and single-bundle reconstruction with remnant pull-out suture. Knee Surg Sports Traumatol Arthrosc. 2013 Jul 27; Authors: Kim SH, Jung YB, Song MK, Lee SH, Jung HJ, Lee HJ, Jung HS, Siti HT Abstract PURPOSE: The purpose of this study was to evaluate the stability and functional outcomes of anterior cruciate ligament (ACL) reconstruction by tensioning of the ACL remnant using pull-out sutures compared with ACL double-bundle reconstruction. METHODS: Forty-four patients were included in single-bundle reconstruction with remnant tensioning group (Group 1), and 56 patients were included in the double-bundle reconstruction group (Group 2). The remnant tissue was tensioned to the direction of posterolateral bundle, which unrelated to the type of remnant bundle. Objective knee stability was evaluated by anterior stress radiography, KT-1000 and lateral pivot shift tests. The Tegner activity scale, International Knee Documentation Committee and OrthopädischeArbeitsgruppeKnie scoring systems were used for clinical evaluation. RESULTS: No statistically significant intergroup differences were observed in mechanical stability and clinical results (n.s). However, surgical time of remnant tensioning group is shorter than double-bundle reconstruction group (P = 0.005).

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Related Articles The use of navigation to achieve soft tissue balance in total knee arthroplasty - A randomised clinical study. Knee. 2013 Jul 26; Authors: Joseph J, Simpson PM, Whitehouse SL, English HW, Donnelly WJ Abstract BACKGROUND: Achieving soft tissue balance is an operative goal in total knee arthroplasty. This randomised, prospective study compared computer navigation to conventional techniques in achieving soft tissue balance. METHODS: Forty one consecutive knee arthroplasties were randomised to either a non-navigated or navigated group. In the non-navigated group, balancing was carried out using surgeon judgement. In the navigated group, balancing was carried out using navigation software. In both groups, the navigation software was used as a measuring tool. RESULTS: Balancing of the mediolateral extension gap was superior in the navigation group (p=0.001). No significant difference was found between the two groups in balancing the mediolateral flexion gap or in achieving equal flexion and extension gaps. CONCLUSIONS: Computer navigation offered little advantage over experienced surgeon judgement in achieving soft tissue balance in knee replacement. However, the method employed in the navigated group did provide a reproducible and objective assessment of flexion and extension gaps and may therefore benefit surgeons in training. LEVEL OF EVIDENCE: Level I, RCT.

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Related Articles Unsatisfactory Accuracy With VISIONAIRE Patient-Specific Cutting Jigs for Total Knee Arthroplasty. J Arthroplasty. 2013 Jul 25; Authors: Lustig S, Scholes CJ, Oussedik S, Kinzel V, Coolican MR, Parker DA PMID: 23891059 [PubMed - as supplied by publisher]Read more... http://www.ncbi.nlm.nih.gov/pubmed/23891059?dopt=Abstract

Related Articles Effect of Patellar Thickness on Knee Flexion in Total Knee Arthroplasty: A Biomechanical and Experimental Study. J Arthroplasty. 2013 Jul 25; Authors: Abolghasemian M, Samiezadeh S, Sternheim A, Bougherara H, Barnes CL, Backstein DJ Abstract A biomechanical computer-based model was developed to simulate the influence of patellar thickness on passive knee flexion after arthroplasty. Using the computer model of a single-radius, PCL-sacrificing knee prosthesis, a range of patella-implant composite thicknesses was simulated. The biomechanical model was then replicated using two cadaveric knees. A patellar-thickness range of 15mm was applied to each of the knees. Knee flexion was found to decrease exponentially with increased patellar thickness in both the biomechanical and experimental studies. Importantly, this flexion loss followed an exponential pattern with higher patellar thicknesses in both studies. In order to avoid adverse biomechanical and functional consequences, it is recommended to restore patellar thickness to that of the native knee during total knee arthroplasty. PMID: 23891057 [PubMed - as supplied by publisher]Read more... http://www.ncbi.nlm.nih.gov/pubmed/23891057?dopt=Abstract