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Background: This 1-stage cell-free scaffold-based technique is indicated for the treatment of full-thickness chondral and osteochondral lesions in the knee, regardless of the lesion size. The aim of the procedure is restoration of the osteochondral unit while avoiding the issues of donor site morbidity and those related to cell management. Description: The surgical technique is simple and can be performed as a 1- stage procedure. The lesion site is visualized through a standard knee medial or lateral parapatellar arthrotomy. The defect is prepared by excision of the injured cartilage and subchondral bone to ensure adequate bone-marrow blood flow and to create a squared, regularly shaped lodging for the device. The scaffold is then shaped and sized according to the dimensions of the prepared lesion site and implanted by press-fitting or with addition of fibrin glue. Finally, the complete range of motion is tested to assess the stability of the implant before and after releasing the tourniquet. Alternatives: Nonsurgical alternatives have been reported to include nonpharmacological modalities, such as dietary supplements, and pharmacological therapies as well as physical therapies and novel biological procedures involving injections of various substances1. There are several surgical alternatives, including among others microfracture, mosaicplasty, osteochondral allograft, and total knee arthroplasty, depending primarily on the disease stage and etiology as well as the specific patient conditions2,3. Rationale: This cell-free device is engineered in 3 layers to mimic the structure and composition of the osteochondral unit in order to guide resident cells toward an ordered regeneration of both bone and cartilage layers, providing a better quality of regenerated articular surface. The treatment approach offers a useful alternative to current procedures in the field of osteochondral lesions, in particular for young and middle-aged patients affected by symptomatic defects in which subchondral bone is likely involved. The advantages of this scaffold include the ability to perform a 1-stage surgical procedure, off-the-shelf availability, a straightforward surgical technique, and lower costs compared with cell-based regenerative options. Furthermore, in contrast to some more traditional treatments, it can be used for large lesions. [ABSTRACT FROM AUTHOR]

Background: When anterior cruciate ligament (ACL) reconstruction fails, a revision procedure may be performed to improve knee function, correct instability, and allow return to activities. The results of revision ACL reconstruction have been reported to produce good but inferior patient-reported and objective outcomes compared with primary ACL reconstruction, but the degree to which this is the case varies widely among published studies and may be influenced by heterogeneity of patients, techniques, and endpoints assessed. For those reasons, a systematic review may provide important insights.Questions/purposes: In a systematic review, we asked: (1) What is the proportion of revision ACL reconstruction cumulative failures defined as rerupture or objective failure using prespecified clinical criteria at mean followup of at least 5 years? (2) What are the most common complications of revision ACL reconstruction?Methods: A systematic review was performed by searching PubMed/Medline, EMBASE, and CENTRAL. We included studies that reported the clinical evaluation of revision ACL reconstruction with Lachman test, pivot shift test, side-to-side difference with KT-1000/2000 arthrometer, and with a mean followup of at least 5 years. We excluded studies that incompletely reported these outcomes, that reported only reruptures, or that were not in the English language. Extracted data included the number of graft reruptures and objective clinical failure, defined as a knee that met one of the following endpoints: Lachman test Grade II to III, pivot shift Grade II to III, KT-1000/2000 > 5-mm difference, or International Knee Documentation Committee Grade C or D. For each study, we determined the proportion of patients who had experienced a rupture of the revision ACL graft as well as the proportion of patients who met one or more of our clinical failure endpoints. Those proportions were summed for each study to generate a percentage of patients who met our definition of cumulative failure. Complications and reoperations were recorded but not pooled as a result of inconsistency of reporting and heterogeneity of populations across the included studies. Of the 663 screened studies, 15 articles were included in the systematic review. Because one study reported two separate groups of patients with different treatments, 16 case series were considered in the evaluation.Results: The proportion of reruptures (range, 0%-25%) was > 5% in only four of 16 series and > 10% in only one of them. The objective clinical failures (range, 0%-82%) was > 5% in 15 of 16 series and > 10% in 12 of them. The proportion exceeded 20% in five of 16 series. The cumulative failures (range, 0%-83%) was > 5% in all except one series and > 10% in 12 of 16 series; five series had a cumulative failure proportion > 20%. The most frequent complications were knee stiffness and anterior knee pain, whereas reoperations were primarily débridement and meniscectomies.Conclusions: Considering rerupture alone as a failure endpoint in patients who have undergone revision ACL reconstruction likely underestimates the real failure rate, because the percentage of failures noticeably increases when objective criteria are also considered. Whether patient-reported and subjective scores evaluating knee function, level of activity, satisfaction, and pain might also contribute to the definition of failure may be the focus of future studies.Level Of Evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: Although 7% to 38% of revision total knee arthroplasties (RTKAs) are attributable to prosthetic knee infections, controversy exists regarding the best surgical approach while reducing the risk of extensor mechanism complications and the reinfection rate. Questions/purposes: We compared The Knee Society Score (KSS), incidences of complications, maximum knee flexion, residual extension lag, and reinfection rate in patients with prosthetic knee infections treated with two-stage RTKAs using either the tibial tubercle osteotomy (TTO) or the quadriceps snip (QS) for exposure at the time of reimplantation. Methods: We prospectively followed 81 patients with chronic prosthetic knee infections treated between 1997 and 2004. Patients were randomized to receive a TTO or QS for exposure at the time of reimplantation. All patients had the same rehabilitation protocol. The minimum followup was 8 years (mean, 12 years; range, 8-15 years). Results: Patients in the TTO group had a higher mean KSS than the QS group (88 versus 70, respectively). Mean maximum knee flexion was greater in the TTO group (113° versus 94°); with a lower incidence of extension lag (45% versus 13%). We observed no differences in reinfection rate between groups. Conclusions: We found the TTO combined with an early rehabilitation protocol associated with superior KSS did not impair extensor mechanism function or increase the reinfection rate. We believe a two-stage RTKA with TTO is a reasonable approach for treating prosthetic knee infections. Level of Evidence: Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: The literature suggests survivorship of unicompartmental knee arthroplasties (UKAs) for spontaneous osteonecrosis of the knee ranges from 93% to 97% at 10 to 12 years. However, these data arise from small series (23 to 33 patients), jeopardizing meaningful conclusions. Questions/purposes: We determined (1) the longer-term survivorship of UKAs in a larger group of patients with spontaneous osteonecrosis of the knee; (2) their subjective, symptomatic, and functional outcomes; and (3) the percentage of failures and reasons for failures to identify relevant indications, contraindications, and technical parameters for treatment with a modern implant design. Methods: We retrospectively evaluated all 84 patients with late-stage spontaneous osteonecrosis of the knee who had a medial UKA from 1998 to 2005. All patients had preoperative MRI to confirm the diagnosis, exclude metaphyseal involvement, and confirm the absence of major degenerative changes in the lateral and patellofemoral compartments. The mean age of the patients at surgery was 66 years and mean BMI was 28.9. We conducted Kaplan-Meier survival analysis using revision for any reason as the end point. Minimum followup was 63 months (mean, 98 months; range, 63-145 months). Results: Ten-year survivorship was 89%. Ten revisions were performed; the most common reasons were subsidence of the tibial component (four) and aseptic loosening of the tibial component (three). No patient underwent revision for progression of osteoarthritis in the lateral or patellofemoral compartments. Conclusions: Our data suggest spontaneous osteonecrosis of the knee may be an indication for UKA, provided secondary osteonecrosis of the knee is ruled out, preoperative MRI documents the absence of disease in other compartments, and there is no overcorrection in any plane. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Knee dislocation is a severe but relatively uncommon injury caused by violent trauma that can result in long-term complications, such as arthrofibrosis, stiffness, instability, and pain. Perhaps owing in part to its rarity, treatment of this injury is controversial. We therefore describe a treatment approach for these complex cases involving a novel dynamic knee external fixator. Description of Technique: We performed open PCL reconstruction when possible and/or repair of other associated lesions. At the end of the surgical procedure, the surgeon applied an external fixator that reproduced normal knee kinematics, allowing early motion exercises and reducing the risk of joint stiffness while protecting the bony and soft tissue structures involved in the repair during the first healing phase. Patients and Methods: We retrospectively reviewed eight patients treated with this approach, four of whom had the PCL reconstructed and four of whom had only associated injuries reconstructed. We evaluated all patients with clinical scores (subjective International Knee Documentation Committee form, Lysholm score, and Tegner level), physical examination (objective International Knee Documentation Committee form), and KT-1000™ arthrometer for AP laxity. Minimum followup was 10 months (mean, 26 months; range, 10-45 months). Results: One patient had manipulation under anesthesia. The median Lysholm score was 76, Tegner level was 4, and subjective International Knee Documentation Committee was 73. All patients recovered to their preinjury work activity, except one unemployed patient. Stability was normal or nearly normal in five patients; the mean side-to-side difference in AP displacement with manual maximum force was 2.9 mm. Conclusions: This approach with an external fixator allowed staged reconstruction and early motion and provided reasonable stability, ROM, and activity level at followup in patients with complex injuries. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]