CLINICAL OUTCOMES AFTER MEDIAL PATELLOFEMORAL LIGAMENT RECONSTRUCTION UTILIZING ALLOGRAFT TISSUE IN PEDIATRIC AND ADOLESCENT PATIENTS: MINIMUM 2-YEAR FOLLOW-UP

Background: Medial patellofemoral ligament (MPFL) reconstruction has gained popularity as a tool to manage recurrent patellar instability. The use of allograft for reconstruction includes benefits of quicker surgical time and obviating donor-site morbidity. In anterior cruciate ligament (ACL) reconstruction hesitancy exists to use allograft in younger patients based on data demonstrating higher graft failure rates. However, a similar trend of allograft failure has not been demonstrated for reconstruction of the MPFL, which has a lower tensile strength than that of the ACL. Hypothesis/Purpose: The purpose of this study is to evaluate outcomes including recurrent instability after MPFL reconstruction utilizing allograft tissue in pediatric and adolescent patients. Methods: A retrospective review was performed to identify patients of a single surgeon with MPFL reconstructions with allograft for recurrent patellar instability with minimum two-year follow-up. Surgical management was recommended after minimum six weeks of nonoperative management including bracing, physical therapy, and activity modification. Pre-operative x-rays were evaluated to assess physeal closure, lower extremity alignment and trochlear morphology, and Insall-Salvati and Caton-Deschamps ratios. MRIs were reviewed to evaluate the MPFL, trochlear morphology, and tibial tubercle trochlear groove distance (TT-TG). The allograft was fixed with a bioabsorbable screw. Descriptive statistics were used to characterize data. The primary outcome was recurrent instability. Results: 20 patients (23 knees) 14 females (17 knees) with average age 15.8 years (range: 11.5-19.6 years) underwent MPFL reconstruction with allograft with average follow-up of 3.6 years (range: 2.2-5.9 years). Physes were open in 8 knees. Average Insall-Salvati ratio was 1.08 ± 0.16 and Caton-Deschamps index was 1.18 ± 0.15. Eighteen patients were noted to have trochlear dysplasia pre-operatively and TT-TG was 15.4 ± 3.9 mm. The three knees (13.0%) with complications had open physes – two (8.7%) had recurrent instability requiring subsequent operation and one sustained a patella fracture requiring open reduction internal fixation. The average Insall-Salvati of these three patients was 1.26 ± 0.21, Caton-Deschamps was 1.18 ± 0.21, and TT-TG was 18.3 ± 3.5mm. There were no growth disturbances noted post-operatively. Conclusion: MPFL reconstruction using allograft tissue may be performed safely in the pediatric and adolescent population with good outcomes at mid-term follow-up with few complications and low rate of recurrent instability. Anatomic factors for may contribute to recurrent instability and complications post-operatively, though larger numbers are needed for statistical analyses. Further prospective and randomized evaluation comparing autograft to allograft reconstruction is warranted to understand graft failure rates.

Initial study on removing cellular residues from hydrostatic high-pressure treated allogeneic tissue using ultrasound

Hydrostatic high-pressure technology (HHD) devitalizes tissue quickly and gently, without negatively affecting the structural properties. HHD-treated tissues must be cleaned from devitalized cells. A partially automated, gentle, reproducible and timesaving rinsing test setup utilizing ultrasound is demonstrated in this study. The test setup is used to clean HHD-treated bone allografts of tissue residues and prevent microbiological contamination. A rinsing procedure is investigated. Residual DNA content determination is utilized to analyze cleaned bone allograft tissue for rinsing procedure evaluation.

Terminal Sterilization of Anterior Cruciate Ligament (ACL) Allografts: A Systematic Review of Outcomes

Introduction. Anterior cruciate ligament (ACL) injuries are common and reconstruction can be completed with either autograft or allograft tissue. However, there is concern about an increased failure rate with allograft tissue. The purpose of this study was to systematically review the available evidence to determine the effect of irradiation and level of dose on the failure rates of allograft in ACL reconstruction. Methods. A literature search was performed using PubMed, Scopus, and Web of Science from January 2000 to September 2013. Inclusion criteria consisted of the following: (1) primary, unilateral, single-bundle allograft ACL procedure, (2) studies with data documenting graft type and terminal sterilization technique, (3) subjective assessments of outcome, and (4) objective assessments of outcome. Studies without reported subjective and objective outcomes and those pertaining to revision ACL reconstruction were excluded. Failures were defined and compared between irradiated and non-irradiated grafts, as well as between grafts irradiated with 1.2 - 1.8 Mrad and those with 2.0 - 2.5 Mrad. Results. Of the 242 articles identified via initial search, 17 studies met the final inclusion criteria. A total of 1,090 patients were evaluated in this study, all having undergone unilateral primary ACL reconstruction with allograft tissue with 155 failures. The failure rate between non-irradiated (98/687, 14.7%) and irradiated (57/408, 14.0%) was not statistically significant (p = 0.86). Grafts in the high-dose irradiation group (27/135, 20.0%) had a statistically significant higher (p < 0.001) rate of failure than those in the low-dose irradiation group (30/273, 10.6%). Conclusion. The irradiation of an allograft increases the risk of failure after an ACL reconstruction but the use of lower doses of radiation decreases that risk.

Hand Surgeon Perspectives on Upper Extremity Allograft: A Survey of the American Society for Surgery of the Hand

ABSTRACT Introduction Allograft tissue products have widespread applications across surgical specialties, but little data exist about surgeon attitudes toward the use of these products in the upper extremity. Methods Using a web-based survey, we sought to investigate the use of and feelings toward allograft products among hand surgeons. A short questionnaire was distributed to all active members of American Society for Surgery of the Hand as of October 2015 (N = 2,578). Demographic and practice setting information was collected. Additionally, questions concerning the use of human allograft tissue products of various types including bone, skin, and soft tissues were asked. Results Of 2,578 American Society for Surgery of the Hand members, 406 hand surgeons (15.8%) responded to the survey. A large majority (92%) reported having used allograft products in the upper extremity. Orthopedic-trained surgeons were more likely to have used bone and tendon allograft, whereas plastic and general surgery-trained surgeons were more likely to have used nerve and dermis allograft. Reduced donor site morbidity and complication rates were factors motivating surgeons to use allograft tissue. Conclusions In spite of variation with respect to their use, allograft tissue products are popular and interest in new products, especially to improve flexor tendon pulley reconstruction, is high.

Outcomes of Revision Anterior Cruciate Ligament Surgery in Adolescents

Background: Although primary anterior cruciate ligament (ACL) reconstructions have been well studied in children and adolescents, the literature lacks information about revision ACL reconstructions in this population. Purpose: This study aims to analyze the outcomes of revision ACL surgeries in the pediatric population. Study Design: Case series; Level of evidence, 4. Methods: A retrospective study was performed on all revision ACL reconstructions performed at a single institution between 2009 and 2017. Patient demographic, injury, and operative data from both the initial surgery and the revision were documented. Outcome measures included the Lysholm score, Single Assessment Numeric Evaluation (SANE) score, Tegner activity score, visual analog scale for pain, Hospital for Special Surgery Pediatric Functional Activity Brief Scale score, patient satisfaction, ability to return to the same level of sport, and any additional injury and/or surgery. Outcomes of the revision surgeries were compared with our institution’s outcome database of primary ACL reconstructions. Results: During the study period, 60 revision ACL reconstructions were performed in 57 patients. Of these patients, 84% (n = 48) were available for a minimum 2-year follow-up and a mean follow-up of 4.4 years. A greater number of meniscal tears and cartilage injuries were documented in the revision cohort. Compared with the primary cohort, the revision cohort had lower SANE scores, Lysholm scores, and satisfaction. Furthermore, the revision cohort had a higher rate of graft failure than the primary cohort (21% vs 9%, respectively; P = .015), and only 27% of revision patients returned to the same level of sport. In a comparison of revision procedures performed with autograft versus allograft tissue, the autograft patients had higher Lysholm scores than the allograft patients (91 vs 83, respectively; P = .045) and trended toward a lower failure rate (11% vs 27%, respectively; P = .199). Conclusion: Adolescent patients undergoing revision ACL reconstruction had more meniscal and cartilage abnormalities, poorer functional outcomes, and higher graft failure rates than patients undergoing primary ACL reconstructions. Additionally, revision procedures performed with allograft tissue resulted in lower Lysholm scores and a trend toward higher failure rates. When an ACL graft fails in a young patient, strong consideration should be given to using autograft tissue for the revision.