Initial Outcomes following Fresh Meniscus Allograft Transplantation in the Knee.

Based on recent evidence-based advances in meniscus allograft transplantation (MAT), fresh (viable) meniscus allografts have a potential for mitigating key risk factors associated with MAT failure, and preclinical and clinical data have verified the safety of fresh meniscus allografts as well as possible efficacy advantages compared to fresh-frozen meniscus allografts. The objective of this study was to prospectively assess clinical outcomes for the initial cohort of patients undergoing MAT using fresh meniscus allografts at our center. Patients who were prospectively enrolled in a dedicated registry were included for analyses when they had undergone primary MAT using a fresh meniscus allograft for treatment of medial and/or lateral meniscus deficiency with at least 1-year follow-up data recorded. Forty-five patients with a mean final follow-up of 47.8 months (range = 12-90) were analyzed. Mean patient age was 30.7 years (range = 15-60), mean BMI was 29.7 kg/m2 (range = 19-48), and 14 patients (31%) were female. In total, 28 medial, 13 lateral, and 4 combined medial and lateral MATs with 23 concurrent ligament reconstructions and 2 concurrent osteotomies were included. No local or systemic adverse events or complications related to MAT were reported for any patient in the study. Treatment success rate for all patients combined was 91.1% with 3 patients requiring MAT revision and 1 patient requiring arthroplasty. Treatment failures occurred 8 to 34 months after MAT and all involved the medial meniscus. None of the variables assessed were significantly different between treatment success versus treatment failure cohorts. Taken together, the data suggest that the use of fresh (viable) meniscus allografts can be considered a safe and effective option for medial and lateral meniscus allograft transplantation. When transplanted using double bone plug suspensory fixation with meniscotibial ligament reconstruction, fresh MATs were associated with a 91% success rate, absence of local or systemic adverse events or complications, and statistically significant and clinically meaningful improvements in patient-reported measures of pain and function at a mean of 4 years postoperatively.

Tunnel Overlap Occurs 25% of the Time With Simultaneous Anterior Cruciate Ligament Reconstruction and Lateral Meniscal Root Repair.

Purpose: To assess the risk of socket-tunnel overlap for posterior medial or lateral meniscal root repair combined with anterior cruciate ligament reconstruction (ACLR) using artificial tibias and computed tomography scans for 3-dimensional modeling. Methods: Artificial tibias (n = 27; n = 3/subgroup) were allocated to groups based on inclination of socket-tunnels (55°, 60°, 65°) created for posterior root of the medial meniscus (MMPR) and lateral meniscus posterior root (LMPR) repair, and ACLR. Three standardized socket-tunnels were created: one for the ACL and one for each posterior meniscal root insertion. Computed tomography scans were performed and sequentially processed using computer software to produce 3-dimensional models for assessment of socket-tunnel overlap. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney U tests. Significance was set at P < .05. Results: The present study found no significant risk of tunnel overlap when drilling for combined ACLR and MMPR repair, whereas 7 cases of tunnel overlap occurred between ACL tunnels and LMPR (25.9% of cases). No subgroup or specific pattern of angulation consistently presented significantly safer distances than other subgroups for all distances measured. Conclusions: This study demonstrated 25.9% rate of overlap for combined LMPR repair and ACLR, compared with 0% for MMPR repair with ACLR. Lower ACL drilling angle (55 or 60°) combined with greater lateral meniscus drilling angle (65°) produced no socket-tunnel overlap. Clinical Relevance: Socket-tunnel overlap during meniscal root repair combined with ACLR may compromise graft integrity and lead to impaired fixation and treatment failure of either the ACL, the meniscus, or both. Despite this, risk for socket-tunnel overlap has not been well characterized.

Optimizing Socket-Tunnel Position for Meniscal Allograft Transplantation Combined With ACL Reconstruction: A 3D Model Analysis.

Background: Socket-tunnel overlap during meniscal allograft transplantation (MAT) combined with anterior cruciate ligament reconstruction (ACLR) may compromise graft integrity and lead to impaired fixation and treatment failure. Purpose/Hypothesis: The purpose of this study was to determine optimal socket-tunnel drilling parameters for medial and lateral MAT with concurrent ACLR using artificial tibias and computed tomography (CT) scans for 3-dimensional (3D) modeling. It was hypothesized that clinically relevant socket tunnels could be created to allow for concurrent medial or lateral MAT and ACLR without significant risk for overlap at varying tunnel guide angles. Study Design: Descriptive laboratory study. Methods: A total of 27 artificial right tibias (3 per subgroup) were allocated to 9 experimental groups based on the inclination of the socket tunnels (55°, 60°, and 65°) created for simulating medial and lateral MAT and ACLR. Five standardized socket tunnels were created for each tibia using arthroscopic guides: one for the ACL tibial insertion and one for each meniscus root insertion. CT scans were performed for all specimens and sequentially processed using computer software to produce 3D models for quantitative assessment of socket-tunnel overlap risk. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney U tests. Results: No subgroup consistently presented significantly safer distances than other subgroups for all distances measured. Three cases (11%) and 24 cases (~90%) of tunnel overlap occurred between the ACL tunnel and tunnels for medial and lateral MAT, respectively. Most socket-tunnel overlap (25 of 27; 92.6%) occurred between sockets at depths ranging between 6.3 and 10 mm from the articular surface. For ACLR and posterior root of the lateral meniscus setting, the guide set at 65° increased socket-tunnel distances. Conclusion: When combined ACLR and MAT using socket tunnels for graft fixation is performed, the highest risk for tibial socket-tunnel overlap involves the ACLR tibial socket and the lateral meniscus anterior root socket at a depth of 6 to 10 mm from the tibial articular surface. Clinical Relevance: Setting tibial guides at 65° to the tibial articular surface with the tunnel entry point anteromedial and socket aperture location within the designated anatomic "footprint" will minimize the risk for socket-tunnel overlap.

Comparison of reamer irrigator aspirator (RIA) suspension versus bone marrow aspirate concentrate (BMC) for percutaneous treatment of long bone nonunions-A preclinical canine model.

OBJECTIVE: To compare the bone healing effects of percutaneously delivered bone marrow aspirate concentrate (BMC) versus reamer irrigator aspirator (RIA) suspension in a validated preclinical canine ulnar nonunion model. We hypothesized that BMC would be superior to RIA in inducing bone formation across a nonunion site after percutaneous application. The null hypothesis was that BMC and RIA would be equivalent. METHODS: A bilateral ulnar nonunion model (n= 6; 3 matched pairs) was created. Eight weeks after segmental ulnar ostectomy, RIA from the ipsilateral femur and BMC from the proximal humerus were harvested and percutaneously administered into either the left or right ulnar defect. The same volume (3 ml) of RIA suspension and BMC were applied on each side. Eight weeks after treatment, the dogs were euthanized, and the nonunions were evaluated using radiographic, biomechanical, and histologic assessments. RESULTS: All dogs survived for the intended study duration, formed radiographic nonunions 8 weeks after segmental ulnar ostectomy, and underwent the assigned percutaneous treatment. Radiographic and macroscopic assessments of bone healing at the defect sites revealed superior bridging-callous formation in BMC-treated nonunions. Histologic analyses revealed greater amount of bony bridging and callous formation in the BMC group. Biomechanical testing of the treated nonunions did not reveal any significant differences. CONCLUSION: Bone marrow aspirate concentrate (BMC) had important advantages over Reamer Irrigator Aspirator (RIA) suspension for percutaneous augmentation of bone healing in a validated preclinical canine ulnar nonunion model based on clinically relevant radiographic and histologic measures of bone formation.

Serial ultrasonographic imaging can predict failure after meniscus allograft transplantation.

Introduction: Treatment monitoring after meniscus allograft transplantation (MAT) is challenging. Ultrasonographic (US) imaging has been proposed as a modality that may allow for treatment monitoring after MAT, but has yet to be clinically validated for this purpose. The objective of this study was to assess the capabilities for serial US imaging during the first year after surgery to predict short-term MAT failure. Methods: Patients who had undergone Meniscus-only or Meniscus-Tibia MAT for treatment of medial or lateral meniscus deficiency were prospectively evaluated by US imaging at various time points after transplantation. Each meniscus was evaluated for abnormalities in echogenicity, shape, associated effusion, extrusion and extrusion with weightbearing (WB). Results: Data from 31 patients with a mean follow-up of 32 ± 16 (range, 12-55) months were analysed. MAT failure occurred in 6 patients (19.4%) at a median time point of 20 (range, 14-28) months with 4 (12.9%) converted to total knee arthroplasty. US imaging was effective for assessing MAT extrusion and imaging with WB demonstrated dynamic changes in MAT extrusion. US characteristics that were significantly associated with higher likelihood for MAT failure included abnormal echogenicity, localised effusion, extrusion with WB at 6 months, and localised effusion and extrusion with WB at 1 year. Conclusions: US assessments of meniscus allografts at 6 months after transplantation can effectively determine risk for short-term failure. Abnormal meniscus echogenicity, persistent localised effusion and extrusion with weightbearing were associated with 8-15 times higher odds for failure, which occurred at a median of 20 months post-transplantation.

Initial Validation of a Modified MRI Scoring System for Assessing Outcomes after Single-Surface Osteochondral Shell Allograft Transplantation in the Knee.

The Osteochondral Allograft Magnetic Resonance Imaging Scoring System (OCAMRISS) provides a reproducible method for imaging-based grading for osteochondral allograft (OCA) transplants. However, the OCAMRISS does not account for larger whole-surface OCA shell grafts, and has not been validated for assessing outcomes after shell OCA transplantation. Therefore, the objective of this study was to evaluate a modified OCAMRISS for assessing single-surface shell OCAs in the knee based on strength of correlations for a modified OCAMRISS score with graft success and patient-reported outcomes for pain and function. With institutional review board approval and informed patient consent, patients who underwent large single-surface shell OCA transplantation and magnetic resonance imaging (MRI) exams at 1-year postsurgery were identified from a prospectively enrolled registry. All patients with a minimum of 2 years of clinical follow-up were included in the present study. A modified OCAMRISS, as well as assessment of the percentage of OCA bone incorporation, was used to score each knee. Two radiologists, blinded to patient demographics and outcomes, reviewed all MRIs together to determine a consensus score for each category and %-incorporation for each OCA. Thirteen patients (7 F, 6 M; mean age = 29.8 ± 9.4; mean body mass index = 27.1 ± 5.8); 8 medial femoral condyle, 4 patella, and 1 medial tibial plateau shell OCAs were evaluated. Mean modified OCAMRISS score was 5.2 ± 2.8, range (2-12) and %-integration was 72.7 ± 33.8, range (0-100). Moderate to strong correlations were noted for 1-year modified OCAMRISS total score with final follow-up (FFU) visual analog scale (VAS) pain (r = +0.58) and Single Assessment Numeric Evaluation (SANE) function (r = -0.7) scores, and for 1-year %-incorporation with FFU VAS pain (r = -0.76) and SANE function (r = +0.83) scores. The modified OCAMRISS total score and %-incorporation assessments determined at 1 year following single-surface shell OCA transplantation correlate well with initial patient outcomes and have clinical applicability for monitoring patients after large-shell OCA transplants in the knee.

Biologic Joint Restoration: A Translational Research Success Story.

Treatment options that result in consistently successful outcomes for young and active patients with joint disorders are needed. This article summarizes two decades of rigorous research using a bedside-to-bench- to-bedside translational approach based on the One Health - One Medicine concept that culminated in successful clinical use of biologic joint restoration options for treatment of knee, hip, ankle, and shoulder problems in this growing patient population.

Kinematic Analysis of Lateral Meniscal Oblique Radial Tears in Anterior Cruciate Ligament-Reconstructed Knees: Untreated Versus Repair Versus Partial Meniscectomy.

BACKGROUND: Lateral meniscal oblique radial tears (LMORTs) affect joint and meniscal stability in anterior cruciate ligament (ACL)-deficient knees. PURPOSE: To determine the clinically relevant kinematics associated with the most common posterior horn LMORT lesion types, types 3 (LMORT3) and 4 (LMORT4), untreated versus arthroscopic repair versus partial meniscectomy in combination with ACL reconstruction (ACLR). STUDY: Controlled laboratory study. METHODS: Sixteen cadaveric knees underwent robotic testing for anterior drawer and pivot-shift simulations at multiple knee flexion angles in ACL-intact and ACL-deficient states, followed by sequential testing of arthroscopic ACLR, LMORT3 lesion, LMORT3 repair, and partial meniscectomy (n = 8). The same testing sequence was performed for LMORT4 lesions (n = 8). RESULTS: ACLR restored kinematics in ACL-deficient knees to intact levels for all metrics tested. For anterior drawer, ACLR + LMORT3 tear and partial meniscectomy resulted in significantly greater anterior translation compared with ACL-intact at all angles (P < .05) and compared with ACLR at 60° and 90° (P < .014). For pivot shift, compared with ACL-intact knees, ACLR + LMORT3 tear resulted in significantly more anterior translation at 15° (P = .041); and for ACLR + partial meniscectomy, at both 0° and 15° (P < .03). ACLR + LMORT4 tear and partial meniscectomy resulted in significantly greater anterior translation for anterior drawer (P < .04) and pivot-shift testing (P < .05) compared with intact and ACLR knees at all angles tested. ACLR + LMORT3 repair and ACLR + LMORT4 repair restored kinematics to ACLR and intact levels at all angles tested. ACLR + LMORT3 tear (P < .008) and both LMORT4 tear and partial meniscectomy (P < .05) resulted in increased meniscal extrusion compared with intact and ACLR statuses at all tested angles for anterior drawer and pivot shift, while repairs restored meniscal stability to ACLR and intact levels. CONCLUSION: Untreated LMORT tears increased anterior translation, pivot shift, and meniscal extrusion after ACLR, while partial meniscectomy further exacerbated these detrimental effects in this cadaveric model. In contrast, arthroscopic side-to-side repair of LMORT lesions effectively restored measured knee kinematics. CLINICAL RELEVANCE: LMORT lesions are common with ACL tears and adversely affect joint stability and meniscal extrusion. This study highlights the importance of repair of LMORT 3 and 4 lesions at the time of ACLR.

Alveolar echinococcosis in a dog in Missouri, USA.

A 10-y-old, castrated male Boxer dog that was born and had lived in Missouri without any travel history to other states, except for a few trips to Kansas, was presented with a distended abdomen and declined health. Ultrasonographic examination revealed a large hepatic mass, and the dog was euthanized. A postmortem examination revealed that the left liver lobes were largely replaced by a white-to-tan multilobular mass with a cobblestone surface. The lesion also involved the diaphragm. Histologically, hepatic architecture was effaced by large areas of necrosis with numerous, ≤0.2-cm, cystic structures that stained positively with periodic acid-Schiff stain and contained calcareous corpuscles. Gross and microscopic hepatic lesions were compatible with alveolar echinococcosis (AE) caused by Echinococcus multilocularis. PCR examination confirmed E. multilocularis, and results from genotyping were consistent with the E4 haplotype. To our knowledge, this is only the second canine AE case and the third pet dog that has been confirmed to be infected by E. multilocularis in the contiguous United States. E. multilocularis is a serious health risk for both pet dogs and humans.

Development and Assessment of Novel Multiligament Knee Injury Reconstruction Graft Constructs and Techniques.

Multiligament knee injury (MLKI) typically requires surgical reconstruction to achieve the optimal outcomes for patients. Revision and failure rates after surgical reconstruction for MLKI can be as high as 40%, suggesting the need for improvements in graft constructs and implantation techniques. This study assessed novel graft constructs and surgical implantation and fixation techniques for anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), posterior medial corner (PMC), and posterior lateral corner (PLC) reconstruction. Study objectives were (1) to describe each construct and technique in detail, and (2) to optimize MLKI reconstruction surgical techniques using these constructs so as to consistently implant grafts in correct anatomical locations while preserving bone stock and minimizing overlap. Cadaveric knees (n = 3) were instrumented to perform arthroscopic-assisted and open surgical creation of sockets and tunnels for all components of MLKI reconstruction using our novel techniques. Sockets and tunnels with potential for overlap were identified and assessed to measure the minimum distances between them using gross, computed tomographic, and finite element analysis-based measurements. Percentage of bone volume spared for each knee was also calculated. Femoral PLC-lateral collateral ligament and femoral PMC sockets, as well as tibial PCL and tibial PMC posterior oblique ligament sockets, were at high risk for overlap. Femoral ACL and femoral PLC lateral collateral ligament sockets and tibial popliteal tendon and tibial posterior oblique ligament sockets were at moderate risk for overlap. However, with careful planning based on awareness of at-risk MLKI graft combinations in conjunction with protection of the socket/tunnel and trajectory adjustment using fluoroscopic guidance, the novel constructs and techniques allow for consistent surgical reconstruction of all major ligaments in MLKIs such that socket and tunnel overlap can be consistently avoided. As such, the potential advantages of the constructs, including improved graft-to-bone integration, capabilities for sequential tensioning of the graft, and bone sparing effects, can be implemented.

Kinematic Analysis of Lateral Meniscal Oblique Radial Tears in the Anterior Cruciate Ligament-Deficient Knee.

BACKGROUND: Lateral meniscal oblique radial tears (LMORT) occur frequently in conjunction with anterior cruciate ligament (ACL) disruption and are anatomically distinct from meniscus root tears. HYPOTHESIS/PURPOSE: The purpose of this study was to characterize the effects of LMORT types 3 (LMORT3) and 4 (LMORT4) lesions on joint stability and meniscal extrusion in ACL-deficient knees. Our hypothesis was that both lesions would promote significant increases in anterior translation and meniscal extrusion, with the LMORT4 lesion having a greater effect. STUDY DESIGN: Controlled laboratory study. METHODS: Two matched pairs of cadaveric knees (n = 4) were used to optimize the testing sequence. Additional cadaveric knees with LMORT3 (n = 8) and LMORT4 (n = 8) lesions created after ACL transection underwent robotic kinematic testing for anterior drawer and pivot-shift simulations with associated ultrasound-measured meniscal extrusion at clinically relevant knee flexion angles. RESULTS: Optimization testing showed no differences on the effect of LMORT4 lesions for anterior translation and lateral meniscal extrusion with ACL-intact versus ACL-deficient knees. ACL deficiency and LMORT3 and LMORT4 lesions with ACL deficiency were associated with significantly greater anterior translation compared with ACL-intact state for both anterior drawer and pivot-shift testing at all flexion angles (P < .001). ACL deficiency with either LMORT3 or LMORT4 lesion was associated with significantly greater anterior translation than was ACL deficiency only (P < .005) for anterior drawer testing at 90° of flexion. Meniscal extrusion was greater with LMORT3 and LMORT4 lesions compared with ACL deficiency only (P < .05) for anterior drawer at 60° of flexion and for pivot shift at 15° of flexion. The LMORT4 lesion demonstrated increased anterior translation for anterior drawer (P = .003) at 60° of flexion (12%) as well as for pivot shift at 15° of flexion (7%) and 30° of flexion (13%) (P < .005) compared with ACL deficiency only. CONCLUSION: In this cadaveric model, the addition of an LMORT3 or LMORT4 lesion increased anterior laxity for both the anterior drawer and the pivot shift when compared with an isolated ACL tear. Lateral meniscal extrusion was also exacerbated by these LMORT lesions. CLINICAL RELEVANCE: LMORT lesions, distinct from meniscus root tears, occur frequently in conjunction with ACL tears. This study characterized the biomechanical consequences of LMORT3 and LMORT4 lesions on joint stability and meniscal function, highlighting the importance of diagnosing and treating LMORT lesions at the time of ACL reconstruction.

Imaging Review of the Posterior Cruciate Ligament.

Posterior cruciate ligament (PCL) injuries can often be missed on physical examination, especially in multiligament knee injuries. Therefore, a comprehensive approach to imaging the PCL should be implemented whenever history and examination findings indicate relative risk. Radiography, including a posterior-stress view, and magnetic resonance imaging, when available, provide consistently accurate diagnosis of PCL pathology and common knee comorbidities. Computed tomography and ultrasonography can be useful modalities with potential advantages with respect to availability and access, specific comorbidities, and/or cost-effectiveness.

Comparison of meniscal allograft transplantation techniques using a preclinical canine model.

Meniscal allograft transplantation (MAT) can be a safe, effective treatment for meniscal deficiency resulting in knee dysfunction, leading to osteoarthritis (OA) without proper treatment with 5-year functional success rates (75%-90%). While different grafts and techniques have generally proven safe and effective, complications include shrinkage, extrusion, progression of joint pathology, and failure. The objective of this study was to assess the functional outcomes after MAT using three different clinically-relevant methods in a preclinical canine model. The study was designed to test the hypothesis that fresh meniscal-osteochondral allograft transplantation would be associated with significantly better function and joint health compared with fresh-viable or fresh-frozen meniscus-only allograft transplantations. Three months after meniscal release to induce meniscus-deficient medial compartment disease, research hounds (n = 12) underwent MAT using meniscus allografts harvested from matched dogs. Three MAT conditions (n = 4 each) were compared: frozen meniscus-fresh-frozen meniscal allograft with menisco-capsular suture repair; fresh meniscus-fresh viable meniscal allograft (Missouri Osteochondral Preservation System (MOPS)-preservation for 30 days) with menisco-tibial ligament repair; fresh menisco-tibial-fresh, viable meniscal-tibial-osteochondral allografts (MOPS-preservation for 30 days) with menisco-tibial ligament preservation and autogenous bone marrow aspirate concentrate on OCA bone. Assessment was performed up to 6 months after MAT. Pain, comfortable range of motion, imaging, and arthroscopic scores as well histological and cell viability findings were superior (P < .05) for the fresh menisco-tibial group compared with the two other groups. Novel meniscal preservation and implantation techniques with fresh, MOPS-preserved, viable meniscal-osteochondral allografts with menisco-tibial ligament preservation appears to be safe and effective for restoring knee function and joint health in this preclinical model. This has the potential to significantly improve outcomes after MAT.

Superior Capsular Reconstruction Using Dermal Allograft Is a Safe and Effective Treatment for Massive Irreparable Rotator Cuff Tears: 2-Year Clinical Outcomes.

PURPOSE: To evaluate functional, symptomatic, and diagnostic imaging outcomes after arthroscopic superior capsular reconstruction (SCR) using dermal allograft in patients with massive irreparable rotator cuff tears. METHODS: From 2015 to 2017, this multicenter study retrospectively evaluated patients undergoing arthroscopic SCR for treatment of symptomatic massive rotator cuff tears. Study criteria included the presence of a massive irreparable rotator cuff tear with retraction to the glenoid without diffuse bipolar cartilage loss, Grade 4 or 5 Hamada classification, and subscapularis pathology that could not be addressed. All SCR procedures were performed with neutral abduction of the arm at the time of implantation. Outcome measures included visual analog pain scale (VAS) score, the American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE) score, and active forward elevation (FE) through 2 years postoperatively. Imaging analyses included radiographs, ultrasound, and magnetic resonance imaging at 6 months and 1 year. RESULTS: Fourteen patients met all study criteria including required follow-up. There were statistically significant improvements in VAS pain (3.3-0.6, P = .001), ASES (55.0-86.5, P < .0001), SANE (33.1-71.5, P < .0001), and active FE (128-172, P = .0005) with mean follow-up of 2.1 years. Twelve patients (86%) met the minimum clinically important difference in VAS pain, ASES, and SANE. Thirteen grafts (93%) had ultrasonographic evidence for vascularity by 1 year postoperatively. There were 2 graft complications (14%) with one (7%) requiring revision to reverse total shoulder arthroplasty. CONCLUSIONS: Arthroscopic SCR using dermal allograft can be a safe and effective treatment option for patients with massive irreparable rotator cuff tears with statistically significant improvements in VAS pain, ASES, SANE, and active FE at 2-years postoperatively, with 93% of grafts demonstrating vascularity at 1-year postoperatively. Neutral abduction of the arm at the time of implantation resulted in positive clinical outcomes and may decrease graft failure rate. LEVEL OF EVIDENCE: Level IV, case series.

Unicompartmental bipolar osteochondral and meniscal allograft transplantation is effective for treatment of medial compartment gonarthrosis in a canine model.

Osteochondral allograft (OCA) transplantation can restore large articular defects in the knee. Bipolar OCA transplantations for partial and whole joint resurfacing often have less favorable results than single-surface transplants. This study was designed to use a large animal model to test the hypothesis that unicompartmental bipolar osteochondral and meniscal allograft transplantation (BioJoint) would be as or more effective for treatment of medial compartment osteoarthritis (OA) compared to standard-of-care nonoperative treatment. OA was induced in one knee of each research hound (n = 8) using a meniscal release model and pretreatment assessments were performed. After 3 months, dogs were randomly assigned to either the control group (n = 4, no surgical intervention, daily nonsteroidal antiinflammatory drugs [NSAIDs]) or the BioJoint group (n = 4). Clinical, radiographic, and arthroscopic assessments were performed longitudinally and histopathology was evaluated at the 6-month endpoint. At study endpoint, functional, pain, and total pressure index measures, as well as radiographic and arthroscopic grading of graft appearance and joint health, demonstrated superior outcomes for BioJoints compared to NSAID controls. Furthermore, histologic assessments showed that osteochondral and meniscal transplants maintain integrity and integrated into host tissues. Clinical significance: The results support the safety and efficacy of unicompartmental bipolar osteochondral and meniscal allograft transplantation in a preclinical model with highly functional outcomes without early OA progression.

Initial clinical outcomes comparing frozen versus fresh meniscus allograft transplants.

BACKGROUND: To evaluate initial clinical outcomes using fresh meniscal allografts with high cell viability at transplantation time and meniscotibial ligament (MTL) reconstruction (Fresh) in comparison to standard fresh-frozen (Frozen) meniscus allograft transplantation (MAT). METHODS: Patients treated for medial and/or lateral meniscal deficiency using either Fresh or Frozen MAT with minimum of 1-year follow-up were identified from a prospective registry. Patient demographics, prior surgeries, MAT surgery data, complications, revisions, and failures were documented. Functional outcome scores were collected preoperatively, and 6 months and yearly after surgery and radiographic joint space measurements were performed. Treatment cohorts were compared for statistically significant (P < 0.005) differences using t-Tests and Fisher's exact tests. RESULTS: Twenty-seven patients (14 Fresh, 13 Frozen) met inclusion criteria and showed comparable characteristics. For Fresh MAT + MTL, 10 medial, two lateral, and two medial + lateral MAT were performed. For Frozen MAT, nine medial, and four lateral MAT were performed. There was significantly more improvement in the Fresh cohort compared to the Frozen cohort for VAS pain (P = 0.014), PROMIS Physical Function (P = 0.036) and Single Assessment Numeric Evaluation (P = 0.033) from preoperatively to 2 years postoperatively. Tegner Activity Scale and PROMIS Mobility score showed no significant differences. The International Knee Documentation Committee score revealed a clinically meaningful change for the Fresh group. Radiographic measurements showed no significant differences between groups. There were two Fresh MAT + MTL revisions and one conversion to TKA in each cohort. CONCLUSIONS: Fresh MAT + MTL is safe and associated with potential advantages with respect to initial pain relief and function compared to standard frozen MAT.

Comparison of biologic scaffolds for augmentation of partial rotator cuff tears in a canine model.

BACKGROUND: This study was designed to test the hypothesis that biologic scaffold augmentation of articular-sided partial-thickness supraspinatus tendon tears would be associated with superior functional, imaging, biomechanical, and histologic properties compared with untreated tears in a preclinical canine model. METHODS: With Institutional Animal Care and Use Committee approval, dogs (n = 16) underwent half-thickness resection of the articular portion of the supraspinatus tendon (SST). Defects were treated by débridement (DB) (n = 8) or scaffold augmentation on the bursal side using amnion matrix cord scaffold (AM) (n = 8), decellularized human dermal allograft (AF) (n = 8), or bovine collagen patch (RMP) (n = 8). Control dogs (n = 4; 8 normal shoulders) were included. Assessments included lameness, function, comfortable shoulder range of motion (CROM), pain, ultrasonography, magnetic resonance imaging (MRI), arthroscopy, gross examination, biomechanical testing, and histopathology. RESULTS: At 3 months, CROM was significantly lower and pain significantly higher in DB compared with all other groups. At 6 months, CROM was significantly lower and pain significantly higher in RMP compared with AM and AF, and AM and AF showed significantly less thickening than DB and RMP. AF had the least severe MRI pathology and AM had significantly less MRI pathology than DB. AF SSTs and biceps tendons showed the least severe histopathology, and AM SSTs showed significantly less histopathology than DB and RMP SSTs. CONCLUSION: Biologic scaffolds can be effective in augmenting healing of articular-sided partial-thickness SST tears when compared with débridement in a preclinical canine model. Decellularized human dermal allograft and amnion matrix cord may have advantages over the bovine collagen patch for use in this indication.

Canine models of spine disorders.

Neck and low back pain are common among the adult human population and impose large social and economic burdens on health care and quality of life. Spine-related disorders are also significant health concerns for canine companions with etiopathogeneses, clinical presentations, and diagnostic and therapeutic options that are very similar to their human counterparts. Historically, induced and spontaneous pathology in laboratory rodents, dogs, sheep, goats, pigs, and nonhuman primates have been used for study of human spine disorders. While each of these can serve as useful preclinical models, they all have inherent limitations. Spontaneously occurring spine disorders in dogs provide highly translatable data that overcome many of the limitations of other models and have the added benefit of contributing to veterinary healthcare as well. For this scoping review, peer-reviewed manuscripts were selected from PubMed and Google Scholar searches using keywords: "intervertebral disc," "intervertebral disc degeneration," "biomarkers," "histopathology," "canine," and "mechanism." Additional keywords such as "injury," "induced model," and "nucleus degeneration" were used to further narrow inclusion. The objectives of this review were to (a) outline similarities in key features of spine disorders between dogs and humans; (b) describe relevant canine models; and (c) highlight the applicability of these models for advancing translational research and clinical application for mechanisms of disease, diagnosis, prognosis, prevention, and treatment, with a focus on intervertebral disc degeneration. Best current evidence suggests that dogs share important anatomical, physiological, histological, and molecular components of spinal disorders in humans, such that induced and spontaneous canine models can be very effective for translational research. Taken together, the peer-reviewed literature supports numerous advantages for use of canine models for study of disorders of the spine when the potential limitations and challenges are addressed.

Knee Ultrasonography to Determine Risk for Noncontact Injuries in Collegiate American Football Players.

Knee ultrasonography has been used effectively as a screening tool for determining risk for knee injuries in athletes. Ultrasonography may be a valuable screening tool for relative risk of noncontact knee injuries that occur over a typical playing career in collegiate American football players. In this prospective longitudinal study, we evaluated American football players (n = 48) in an academic institution affiliated with the National Collegiate Athletic Association Division I athletic program. Players underwent comprehensive ultrasonography of both knees prior to beginning their collegiate careers. Anatomic structures were evaluated for presence and severity of abnormalities. Noncontact lower extremity injuries sustained over the collegiate career of the subjects were documented. Data were analyzed for correlations, differences in proportions, and odds ratio (OR). Seventy-nine percent of the athletes had at least one ultrasonographic abnormality, with quadriceps tendon (47.9%) and patellar tendon (39.6%) abnormalities predominating. Seventy-nine percent of players had at least one noncontact lower extremity injury (23.5% involving the knee) during their careers with an average of 2.8 injuries per career. The majority of injuries occurred in the second and third playing years. There was a significantly higher likelihood of patellar tendon injury based on the presence of patellar tendon ultrasonographic pathology (p = 0.024; OR = 11x). There was a significantly higher likelihood of quadriceps muscle-tendon injury based on the presence of quadriceps tendon ultrasonography pathology (p = 0.0012; OR = 140x). All athletes sustaining meniscal injuries had preexisting joint effusion but no preexisting ultrasonographic meniscal pathology. Knee ultrasonography along with patient history and complete physical examination may help reduce injury risk through education, prevention, and training programs.

Patellar Bone-Tendon-Bone Autografts versus Quadriceps Tendon Allograft with Synthetic Augmentation in a Canine Model.

Patellar bone-tendon-bone (pBTB) autografts are often considered the "gold standard" for complete anterior cruciate ligament (ACL) reconstruction and are also associated with significant complications and early-onset knee osteoarthritis (OA). A novel quadriceps tendon allograft with synthetic augmentation, or "internal brace" (QTIB), has been reported to have potential advantages for ACL reconstruction based on animal model data. In this preclinical canine comparison study, we hypothesized that QTIB allograft compared with pBTB autograft would provide superior durability for knee stability, function, and prevention of OA. Under approval from our Institutional Animal Care and Use Committee, adult purpose-bred research hounds (n = 10) underwent arthroscopic complete transection of the ACL followed by either an arthroscopic-assisted all-inside ACL reconstruction using the QTIB allograft (n = 5) or pBTB autograft (n = 5). Contralateral knees were used as nonoperated controls (n = 10). Radiographic and arthroscopic assessments were performed at 2 and 6 months, respectively, after surgery. Anterior drawer, internal rotation, lameness, kinetics, pain, effusion, and comfortable range of knee motion were measured at 2, 3, and 6 months. Biomechanical and histologic assessments were performed at 6 months. All reconstructed knees were stable and had intact ACL grafts 6 months after surgery. At 6 months, QTIB reconstructed knees had significantly less lameness, lower pain, less effusion, and increased range of motion when compared with BTB knees (p < 0.05). BTB knees had significantly higher radiographic OA scores than QTIB knees at 6 months (p < 0.05). Superior outcomes associated with QTIB allograft may be due to the lack of donor site morbidity, the use of a robust tendon graft, and/or protection of the graft from the synthetic augmentation. Robust tendon grafts combined with a synthetic internal brace and platelet-rich plasma (PRP) may allow for more rapid and robust tendon-bone healing and graft "ligamentization," which protects the graft from early failure and rapid OA development that can plague commonly-used allografts.