Clinical Registry Assessment of the Missouri Osteochondral Allograft Preservation System - MOPS

Overview

With institutional review board approval and informed consent, patients are prospectively enrolled into a registry to follow outcomes after osteochondral allograft (OCA) and/or meniscal allograft transplantation. Patients are included when 1 year followup data are available, including complications and reoperations, patient reported outcome measures (PROMs), compliance with rehabilitation, revisions, and failures. In addition, MOPS grafts are compared to standard preservation grafts, and unipolar, multisurface, and bipolar cohorts, as well as patient compliance variables, are compared.

With institutional review board approval and documented informed consent, patients are prospectively enrolled into a dedicated registry designed to follow outcomes after OCA transplantation with or without meniscal allograft transplantation. All grafts are obtained from tissue banks accredited by the American Association of Tissue Banks (AATB) and used in conformance of the tissue to the US Food and Drug Administration classification of a human cell and tissue product under section 361 of the Public Health Services Act. Initially, standard preservation (SP) grafts stored in refrigeration in proprietary solutions for 21 days after recovery from 1 of 3 AATB accredited tissue banks were used. As a separate arm, first clinical use of Missouri Osteochondral Preservation System (MOPS) grafts, which are stored at room temperature using MOPS methods for up to 56 days after recovery from 1 AATB accredited tissue bank, was assessed. In phase 2, after MOPS grafts became commercially available, type of graft implanted was based on patient-matched graft availability. Then, on the basis of emerging evidence published in the peer-reviewed medical literature, we implemented a shift in practice to discontinue use of SP grafts at our center. Surgery is performed on patients with at least one large focal full-thickness articular cartilage defect and/or functional deficiency of 1 or both menisci for knee patients, and for hip, ankle or shoulder patients with at least 1 large focal full-thickness defect who chose this treatment option over other nonsurgical or surgical options as indicated and were approved for coverage by their insurance provider. OCA transplantation surgery is performed using press-fit cylindrical grafts and/or custom-cut patient-specific tab-in-slot shell grafts stabilized with either screws, bioabsorbable pins, or bioabsorbable nails. OCA bone is saturated with autogenous bone marrow aspirate concentrate (Angel System; Arthrex, Inc) immediately before implantation after subchondral drill holes are created and the donor bone is thoroughly lavaged to remove marrow elements. Meniscal allograft transplants (fresh or fresh frozen) are performed via a bone plug technique with suspensory fixation or included as part of the tibial OCA transplant. Viable chondrocyte density of OCAs at the time of transplantation are determined when tissues are available, as previously described. Procedure-specific postoperative management protocols are prescribed to each patient undergoing allograft transplantation. All patients receive oral and written instructions regarding postoperative rehabilitation. Data are collected preoperatively and at 6 weeks, 3 months, 6 months, and yearly after surgery for each case. Demographic and operative data are collected from the electronic medical record. Patient-reported outcome measures (PROMs) are collected at each time point. All reported complications and reoperations are recorded in the electronic medical record. Revision is defined as a second operation to revise the osteochondral and/or meniscal allograft in at least 1 part of the patient's joint, and failure is defined as conversion to total or partial artificial joint arthroplasty, joint fusion, or amputation. The decision to pursue revision or failure surgery is based on the attending surgeon's discussion of joint pathology, treatment options, and related prognosis in conjunction with patient preference. Successful outcomes are defined as patients reporting return to functional activities with no need for revision or conversion surgery at last recorded follow-up. Descriptive statistics are calculated to report means, ranges, and percentages. On the basis of the difference in graft preservation methodology, cases are also analyzed by cohort as defined by SP versus MOPS. On the basis of surgery type, cases are also analyzed by cohort as defined by unipolar, multisurface, or bipolar transplants. Chi-square or Fisher exact tests are used to assess for significant differences in proportions. When significant differences in proportions are noted, odds ratios are calculated for relevant comparisons. One-way analysis of variance or t tests are used to assess for significant differences among cohorts at respective time points. Repeated measures analyses of variance are used to assess for significant differences within cohorts over time. Kaplan-Meier survival probability estimates with 95% CIs are calculated and compared. Significance is set at P\<.05.