The Missouri Osteochondral Preservation System Is Associated With Better Short-Term Outcomes Than Standard Preservation Methods When Performing Osteochondral Allograft Transplantation Using Shell Grafts for Patellofemoral Lesions.

PURPOSE: To compare outcomes after whole-surface osteochondral allograft (OCA) transplantation using shell grafts for treatment of patellofemoral joint lesions with respect to surfaces treated and OCA preservation method. METHODS: With institutional review board approval and informed consent, patients were prospectively enrolled into a registry to follow outcomes after OCA transplantation. Patients who received patellofemoral shell OCA to treat the entire articular surface of the patella, trochlea, or both, and with a minimum of 2-year follow-up data, including patient-reported outcome measures (PROMs), failures, and complications, were included. Functional graft survival was determined based on patients returning to functional activities without need for OCA revision or arthroplasty surgery and calculated using the formula: 100% - (%revision + %failure). Minimum clinically important differences were determined based on previously validated data. Outcomes were compared based on differences in graft preservation methodology (Missouri Osteochondral Preservation System [MOPS] or standard preservation [SP]) and based on surfaces treated (patella, trochlea, or both). RESULTS: Fifty-eight patients met inclusion criteria. Mean age was 36.7 years (range 15-60 years) and mean body mass index was 28.9 (range 18-42). OCAs stored using SP methods were transplanted in 12 patients, mean follow-up was (66.1 months; range 54-70 months): OCAs stored using MOPS methods were transplanted in 46 patients, mean follow-up was (44.8 months; range 24-60 months). Graft survival rate at final follow-up was significantly greater (P = .025) for MOPS OCAs (98%) compared with SP OCAs (75%), whereas 2-year functional graft survival rates (MOPS 98% vs SP 83%; P = .1) were not. Reoperation rate was significantly greater (P = .0014) for SP cases compared with MOPS cases. PROMs showed statistically significant and clinically meaningful improvements through 4 years after unipolar patella, unipolar trochlea, and bipolar patellofemoral OCA transplantation using MOPS grafts. Unipolar patella OCA transplantations were associated with significantly more reduction in pain and significantly better PROMs at 1-year compared with unipolar trochlea and bipolar patellofemoral OCAs. CONCLUSIONS: OCA transplantation using MOPS shell grafts for unipolar and bipolar patellofemoral resurfacing was associated with statistically significant and clinically meaningful improvements from preoperative levels of pain and function. The 2-year functional graft survival rate was 83% in the SP group and 98% in the MOPS group, such that MOPS was associated with better short-term outcomes than SP methods when performing OCA transplantation using shell grafts for patellofemoral lesions. Patients who received unipolar patella allografts reported the best outcomes in terms of pain and function. LEVEL OF EVIDENCE: Level III, retrospective analysis of registry data.

Preoperative Planning and Preservation of the Knee with Complex Osteotomies.

The knee is a complex structure composed of bone, cartilage, menisci, ligaments and muscles, which all work synergistically to optimize congruence, stability, and function. Osteotomies are procedures addressing an abnormal joint alignment, shifting the mechanical load from a diseased joint compartment to a healthier one. Preoperative planning is an important art of identifying the source of abnormal load distribution to the joint, enabling the surgeon to simulate a deformity correction ahead of the surgical procedure.

Bench to Bedside: A Multidisciplinary Approach toward the Unknowns after ACL Injuries to Drive Individual Success.

ACL injury and surgery are increasing in prevalence. Several challenges exist that can be obstacles to an individual achieving success after ACL surgery. A knowledge of these risk factors alongside a multidisciplinary collaborative team approach can result in a greater likelihood of achieving individual success after ACL surgery.

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.

Does Blood Flow Restriction Therapy in Patients Older Than Age 50 Result in Muscle Hypertrophy, Increased Strength, or Greater Physical Function? A Systematic Review.

BACKGROUND: Blood flow restriction (BFR) is a process of using inflatable cuffs to create vascular occlusion within a limb during exercise. The technique can stimulate muscle hypertrophy and improve physical function; however, most of these studies have enrolled healthy, young men with a focus on athletic performance. Furthermore, much of the information on BFR comes from studies with small samples sizes, limited follow-up time, and varied research designs resulting in greater design, selection, and sampling bias. Despite these limitations, BFR's popularity is increasing as a clinical rehabilitation tool for aging patients. It is important for practitioners to have a clear understanding of the reported effects of BFR specifically in older adults while simultaneously critically evaluating the available literature before deciding to employ the technique. QUESTIONS/PURPOSES: (1) Does BFR induce skeletal muscle hypertrophy in adults older than 50 years of age? (2) Does BFR improve muscle strength and/or physical function in adults older than 50 years? METHODS: Using PubMed, Google Scholar, Web of Science, and Science Direct, we conducted a systematic review of articles using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess the reported effects of BFR on skeletal muscle in older adults. Included articles enrolled participants 50 years of age or older and used BFR in conjunction with exercise to study the effects of BFR on musculoskeletal outcomes and functionality. The following search terms were used: "blood flow restriction" OR "KAATSU" OR "ischemic training" AND "clinical" AND "elderly." After duplicates were removed, 1574 articles were reviewed for eligibility, and 30 articles were retained with interventions duration ranging from cross-sectional to 16 weeks. Sample sizes ranged from 6 to 56 participants, and exercise tasks included passive mobilization or electrical stimulation; walking; resistance training using machines, free weights, body weight, or elastic bands; and water-based activities. Furthermore, healthy participants and those with cardiovascular disease, osteoarthritis, osteoporosis, sporadic inclusion body myositis, spinal cord injuries, and current coma patients were studied. Lastly, retained articles were assigned a risk of bias score using aspects of the Risk of Bias in Nonrandomized Studies of Interventions and the Cochrane Collaboration's tool for assessing the risk of bias in randomized trials. RESULTS: BFR, in combination with a variety of exercises, was found to result in muscle hypertrophy as measured by muscle cross-sectional area, thickness, volume, mass, or circumference. Effect sizes for BFR's ability to induce muscle hypertrophy were calculated for 16 of the 30 papers and averaged 0.75. BFR was also shown to improve muscle strength and functional performance. Effect sizes were calculated for 21 of the 30 papers averaging 1.15. CONCLUSIONS: Available evidence suggests BFR may demonstrate utility in aiding rehabilitation efforts in adults older than 50 years of age, especially for inducing muscle hypertrophy, combating muscle atrophy, increasing muscle strength, and improving muscle function. However, most studies in this systematic review were at moderate or high risk of bias; that being so, the findings in this systematic review should be confirmed, ideally using greater sample sizes, randomization of participants, and extended follow-up durations. LEVEL OF EVIDENCE: Level II, systematic review.

Use of a Hyperosmolar Saline Solution to Mitigate Proinflammatory and Degradative Responses of Articular Cartilage and Meniscus for Application to Arthroscopic Surgery.

PURPOSE: This study was designed to evaluate differences in proinflammatory and degradative mediator production and extracellular matrix degradation from osteoarthritic knee articular cartilage and meniscus explants treated with either hyperosmolar saline or isotonic saline. METHODS: 6 mm-diameter full-thickness explants were created from articular cartilage and menisci recovered after patients underwent knee surgery. One explant half was treated for 3 hours with hyperosmolar saline (600 mOsm/L) and the corresponding half with isotonic saline (300 mOsm/L). Explants were subsequently cultured for 3 days in tissue culture media. On day 3, media were collected for biomarker analyses. Results were normalized to tissue wet weight and analyzed statistically. RESULTS: Articular cartilage was collected from 10 patients (5 male, 5 female; mean age = 66.9 years) and menisci were collected from 8 patients (2 male, 6 female; mean age = 66 years). Articular cartilage media concentrations of monocyte chemoattractant protein-1 (P = .001) and interleukin (IL)-6 (P = .049) were significantly lower in explants treated with hyperosmolar saline. Meniscus media concentrations of prostaglandin E2 (P = .008), monocyte chemoattractant protein-1 (P = .011), IL-6 (P = .029), IL-8 (P = .012), matrix metalloproteinase-2 (P = .011), and glycosaminoglycan (P = .008) were significantly lower in explants treated with hyperosmolar saline. CONCLUSIONS: Treatment of cartilage and meniscus explants with hyperosmolar saline effectively mitigated key proinflammatory mediator production, as well as degradative mediator production and glycosaminoglycan loss from meniscus, with no detrimental effects noted compared to isotonic saline. CLINICAL RELEVANCE: These results suggest that hyperosmolar saline irrigation fluid may provide a safe alternative to standard isotonic saline irrigation fluid, and could mitigate untoward effects associated with inflammatory responses after standard-of-care knee arthroscopy.

Comprehensive Case-Based Review of Knee Ligament Injuries.

The management of knee ligament injuries continues to evolve, and much debate persists over the timing of surgery, repair versus reconstruction, surgical technique, postoperative rehabilitation, graft selection, and fixation. Surgeons should be aware of updates on the best management strategies of knee ligament injuries in 2018 and understand the important history and physical examination findings of the knee with ligamentous injury; the anterior cruciate ligament; the role of the anterolateral ligament and lateral extra-articular tenodesis; combined anterior cruciate ligament and medial collateral ligament injuries; the posterior cruciate ligament; medial collateral ligament repair versus reconstruction; posterolateral corner repair versus reconstruction; the role of coronal plane osteotomies, including high tibial osteotomy and distal femoral osteotomy; the role of sagittal plane osteotomies, including anterior closing wedge osteotomy and anterior opening wedge osteotomy; the initial management of the multiligament-injured knee; and five keys to avoiding complications in the multiligament-injured knee. The best available evidence and sample case presentations help guide surgical decision making and improve patient outcomes.

Incisional Negative Pressure Wound Therapy Devices Improve Short-Term Wound Complications, but Not Long-Term Infection Rate Following Hip and Knee Arthroplasty.

BACKGROUND: The potential value of incisional negative pressure wound therapy (iNPWT) on lower extremity total joint arthroplasty (TJA) wound healing has been supported in a few retrospective studies. We performed this prospective, randomized, controlled trial to assess the impact of iNPWT on wound appearance, early complications, and late infection rates following hip and knee TJA compared with a standard surgical dressing. METHODS: Three-hundred ninety-eight patients undergoing primary or revision lower extremity TJA were randomized into iNPWT or conventional wound dressing groups. Wound healing and early complication rates were assessed at 7, 14, and 35 days after the index surgery. Late infection rates were determined at a mean 2-year follow-up. RESULTS: Patients treated with an iNPWT device were more likely to report wound drainage at day 7 (P = .01), but less drainage longer than 14 days (P = .04). Wound drainage was significantly higher for total hip arthroplasty patients at day 7 (P = .04), but differences were not sustained through the other time intervals. Total knee arthroplasty patients with a body mass index > 35 kg/m2 treated with an iNPWT device experienced fewer complications (1.3% vs 21.6%, P < .01) and fewer dressing-related concerns (1.3% vs 10.8%, P = .02) compared with a conventional dressing. No significant difference in late superficial or deep infection rates was identified between iNPWT and conventional dressing groups (4.0% vs 3.4%, P = .8). CONCLUSION: Our study findings support improved soft tissue healing response with the use of iNPWT devices. While postoperative wound drainage may limit their value following total hip arthroplasty, incisional NPWT devices may have a targeted benefit for elective total knee arthroplasty patients with a body mass index > 35 kg/m2. Specific study in this higher-risk patient group may be helpful to define the value of iNPWT.

Biologic Joint Repair Strategies: The Mizzou BioJoint Story.

Because articular cartilage has very limited healing potential, most symptomatic cartilage injuries eventually result in end-stage osteoarthritis and are treated with artificial joint replacement. Our interdisciplinary, comparative orthopedic research performed by a team of DVMs, MDs, engineers, and basic scientists has yielded marked progress toward effective biologic joint restoration strategies by bringing bench-side ideas to fruition in bedside applications in both canine and human patients. This mini-review summarizes the progress of biologic joint restoration strategies at our center.

Suspensory Versus Interference Screw Fixation for Arthroscopic Anterior Cruciate Ligament Reconstruction in a Translational Large-Animal Model.

PURPOSE: To compare all-inside cortical-button suspensory fixation in sockets versus interference screw fixation in tunnels with respect to clinical, histologic, and biomechanical assessments of all-soft tissue (AST) tendon autografts used for anterior cruciate ligament (ACL) reconstruction in a canine model. METHODS: By use of a validated "hybrid" double-bundle ACL reconstruction technique (reconstruction of the anteromedial bundle with preservation of the native posterolateral bundle), dogs were randomly assigned to undergo either suspensory fixation in sockets (n = 6) or interference screw fixation in tunnels (n = 6). Contralateral knees were used as nonoperated controls (n = 12). Quadrupled extensor tendon autografts were used for both ACL reconstruction groups. Dogs were assessed radiographically and functionally and humanely euthanized at 12 weeks after surgery for arthroscopic, gross, biomechanical, and histologic assessments. RESULTS: Histologic assessments showed significantly (P = .018) better graft incorporation with 4-zone direct healing to bone for the grafts using suspensory fixation in sockets (16.3 ± 1.5) compared with the grafts using interference screw fixation in tunnels (14.2 ± 2.1). Furthermore, graft healing to bone was significantly better at the aperture (P = .05) and mid-socket (P = .01) location for the group that underwent suspensory fixation in sockets (16.1 ± 1.8 and 16.4 ± 1.9, respectively). CONCLUSIONS: Suspensory fixation of AST grafts in sockets was associated with superior tendon-to-bone healing compared with interference screw fixation in tunnels, with 4-zone direct graft healing to bone seen for femoral and tibial sockets only in the suspensory-fixation group. Biomechanical properties were similar between groups. CLINICAL RELEVANCE: These data provide evidence suggesting that an all-inside ACL reconstruction technique using adjustable-loop cortical-button suspensory fixation in bone sockets has potential clinical advantages for ACL reconstruction using AST grafts.

Acute Management and Surgical Timing of the Multiligament-injured Knee.

Multiligament knee injuries are relatively rare, but the outcomes can be disastrous if they are not identified and treated appropriately. Recent trends in the literature are showing more focus on early identification and subspecialist management as important ways to achieve the best possible outcomes for these injuries. Early identification and the appropriate treatment of associated injury patterns are the keys to improving outcomes. These injuries are usually associated with high-energy trauma, but low-energy injuries also cause these severe injuries in patients with other comorbidities, such as those with high body mass indices. Familiarity with an evidence-based approach is helpful for managing these complex injuries.

A novel system improves preservation of osteochondral allografts.

BACKGROUND: Osteochondral allografting is an option for successful treatment of large articular cartilage defects. Use of osteochondral allografting is limited by graft availability, often because of loss of chondrocyte viability during storage. QUESTIONS/PURPOSES: The purpose of this study was to compare osteochondral allografts implanted in canine knees after 28 days or 60 days of storage for (1) initial (1 week) safety and feasibility; (2) integrity and positioning with time (12 weeks and 6 months); and (3) gross, cell viability, histologic, biochemical, and biomechanical characteristics at an endpoint of 6 months. METHODS: With Institutional Animal Care and Use Committee approval, adult dogs (n=16) were implanted with 8-mm cylindrical osteochondral allografts in the lateral and medial femoral condyles of one knee. Osteochondral allografts preserved for 28 or 60 days using either the current tissue bank standard-of-care (SOC) or a novel system (The Missouri Osteochondral Allograft Preservation System, or MOPS) were used, creating four treatment groups: SOC 28-day, MOPS 28-day, SOC 60-day, and MOPS 60-day. Bacteriologic analysis of tissue culture and media were performed. Dogs were assessed by radiographs and arthroscopy at interim times and by gross, cell viability, histology, biochemistry, and biomechanical testing at the 6-month endpoint. RESULTS: With the numbers available, there was no difference in infection frequency during storage (5% for SOC and 3% for MOPS; p=0.5). No infected graft was implanted and no infections occurred in vivo. MOPS grafts had greater chondrocyte viability at Day 60 (90% versus 53%; p=0.002). For 60-day storage, MOPS grafts were as good as or better than SOC grafts with respect to all outcome measures assessed 6 months after implantation. CONCLUSIONS: Donor chondrocyte viability is important for osteochondral allograft success. MOPS allows preservation of chondrocyte viability for up to 60 days at sufficient levels to result in successful outcomes in a canine model of large femoral condylar articular defects. CLINICAL RELEVANCE: These findings provide a promising development in osteochondral allograft technology that can benefit the quantity of grafts available for use and the quality of grafts being implanted.

Accuracy and reliability of determining the isometric point of the knee for multiligament knee reconstruction.

PURPOSE: To compare the accuracy and reliability of the anatomic and radiographic techniques for identifying the isometric point of the knee. METHODS: Only four specimens were used; however, eight experienced multiligament knee injury surgeons were recruited to address this limitation. Surgeons estimated the isometric point (EIP) on the medial and lateral sides using an anatomic and radiographic method. The x and y coordinates of the EIP were compared to the true isometric point (TIP). T-tests and interclass correlation coefficients (ICC) were performed to determine the accuracy and reliability between the methods. RESULTS: There was no difference in placement of the EIP on the medial side of the knee in the anterior/posterior (x; p = n.s.) and superior/inferior direction (y; p = n.s). The EIP was anterior (p = 0.001) to the TIP with the radiographic method on the lateral side and approached significance (p = 0.05) in the superior/inferior direction. The ICC (95% CI) for identifying the EIP on the medial side in the anterior/posterior direction using the anatomic method was 0.64 (0.28-0.96) and 0.11 (-0.06 to 0.77) in the superior/inferior direction. Using the radiographic method, the ICC in the anterior/posterior and superior/inferior direction was 0.49 (0.14-0.94) and 0.15 (-0.47 to 0.81), respectively. On the lateral side, the ICC for the anatomic method was 0.84 (0.56-0.99) in the anterior/posterior direction and 0.36 (0.05-0.90) in the superior/inferior direction. Using the radiographic method, the ICC in the anterior/posterior and superior/inferior direction was 0.61 (0.26-0.96) and 0.89 (0.67-0.99), respectively. CONCLUSIONS: There was no difference in accuracy on the medial side of the knee. On the lateral side, the anatomic method was more accurate in the anterior/posterior direction. Reliability was greater in the anterior/posterior direction on both sides of the knee. Surgeons were most likely to place the isometric point anterior and superior to the TIP on both the medial and lateral sides of the knee with either method which has the potential to cause graft lengthening. This should be taken into consideration during reconstruction/repair of the MCL/PMC and LCL/PLC.

Accelerated versus Standard Rehabilitation after Meniscus Allograft Transplantation in the Knee.

Meniscus allograft transplantation (MAT) is a proven treatment option for patients with symptomatic irreparable meniscus deficiency. When patients are adherent to prescribed postoperative restriction and rehabilitation protocols, outcomes after MAT are considered good to excellent. However, nonadherence to standard protocols is common and can be associated with undesirable outcomes and patient dissatisfaction. Based on demonstrated safety for early weight-bearing following MAT in conjunction with significant advances in graft preservation and surgical techniques, our joint preservation center implemented a shift in practice toward accelerated weight-bearing following MAT and designed this study to test the hypothesis that accelerated rehabilitation would be associated with superior adherence, patient-reported outcomes, and patient satisfaction, without diminishing patient safety, when compared with standard rehabilitation. Patients were included for analyses when they had undergone fresh or fresh-frozen MAT using a double bone plug technique for treatment of medial or lateral meniscus deficiency and had at least 1-year treatment outcomes recorded. The results of this study revealed that patients who were prescribed accelerated rehabilitation after MAT were significantly more adherent than patients who were prescribed standard rehabilitation and reported statistically significant and clinically meaningful improvements in knee pain and function for at least 1-year following MAT, whereas those in the standard cohort did not. While not statistically different, treatment failure rate was lower in the accelerated rehabilitation cohort when compared with the standard rehabilitation cohort (11 vs. 29%). Importantly, initial outcomes for revision MAT were associated with short-term success in all the patients who opted for this option in the study population. These data suggest that accelerated weight-bearing after MAT is safe, promotes patient adherence, and is associated with statistically significant and clinically meaningful improvements in patient-reported knee pain and function at early and mid-term follow-up.

Outcomes after Anatomic Double-Bundle Posterior Cruciate Ligament Reconstructions Using Transtibial and Tibial Inlay Techniques.

Surgical reconstruction is recommended for symptomatic posterior cruciate ligament (PCL) deficiency. While anatomic double-bundle PCL reconstruction (PCLR) has been reported to be associated with biomechanical and clinical advantages over other methods, there is still debate regarding the optimal technique for tibial positioning and fixation. Based on reported advantages and disadvantages, we employed two tibial fixation techniques, transtibial (TT) and tibial inlay (TI) for anatomic double-bundle PCLR with technique selection based on body mass index, comorbidities, and primary versus revision surgery. This study aimed to compare clinical outcomes following PCLR utilizing either TT or TI techniques to validate relative advantages, disadvantages, and indications for each based on the review of prospectively collected registry data. For 37 patients meeting inclusion criteria, 26 underwent arthroscopic TT PCLR using all-soft- tissue allograft with suspensory fixation in the tibia and 11 patients underwent open TI PCLR using an allograft with calcaneal bone block and screw fixation in the tibia. There were no significant preoperative differences between cohorts. Success rates were 96% for TT and 91% for TI with all successful cases documented to be associated with good-to-excellent posterior stability and range of motion in the knee at the final follow-up. In addition, patient-reported outcome scores were within clinically meaningful ranges for pain, function, and mental health after PCLR in both cohorts, suggesting similarly favorable functional, social, and psychological outcomes. Patient-reported pain scores at 6 months postoperatively were significantly (p = 0.042) lower in the TT cohort, which was the only statistically significant difference in outcomes noted. The results of this study support the use of TT and TI techniques for double-bundle anatomic PCLR in restoring knee stability and patient function when used for the treatment of isolated and multiligamentous PCL injuries. The choice between tibial fixation methods for PCLR can be appropriately based on patient and injury characteristics that optimize respective advantages for each technique.

Impacts of Knee Arthroplasty on Activity Level and Knee Function in Young Patients: A Systematic Review.

The annual demand for knee arthroplasty has been steadily rising, particularly in younger patients. The primary objective of this systematic review was to determine the impact of knee arthroplasties on knee function and activity levels in young (≤55 years) patients. A PubMed search from inception (1977) to March 2022 to identify eligible studies produced 640 peer-reviewed studies for consideration. A total of 18 studies including 4,186 knee arthroplasties in 3,200 patients (mean patient age at the time of surgery: 47.4 years, range: 18-55 years) were ultimately included for analysis. Mean final follow-up (FFU) duration was 5.8 years (range: 2-25.1 years). Mean FFU improvement in Knee Society Clinical Score was 48.0 (1,625 knees, range: 20.9-69.0), Knee Society Function Score was 37.4 (1,284 knees, range: 20-65). Mean FFU for the Tegner and Lysholm activity scale was 2.8 (4 studies, 548 knees, range: 0.7-4.2); University of California Los Angeles Physical Activity Questionnaire score was 2.8 (3 studies, 387 knees, range: 1.2-5); lower extremity activity scale was 1.84 (529 knees). The available evidence suggest that young patients typically realize sustained improvements in knee function compared to preoperative levels; however, these improvements do not typically translate into a return to desired activity levels or quality of life, and this patient population should expect a higher and earlier risk for revision than their older counterparts. Further research, including robust registry data, is needed to establish evidence-based indications, expectations, and prognoses for outcomes after knee arthroplasty in young and active patients.

Characterizing Osteochondral Allograft Biomechanics for Optimizing Transplant Success: A Systematic Review.

Osteochondral allograft (OCA) transplantation has been largely successful in treating symptomatic articular cartilage lesions; however, treatment failures persist. While OCA biomechanics have been consistently cited as mechanisms of treatment failure, the relationships among mechanical and biological variables that contribute to success after OCA transplantation have yet to be fully characterized. The purpose of this systematic review was to synthesize the clinically relevant peer-reviewed evidence targeting the biomechanics of OCAs and the impact on graft integration and functional survival toward developing and implementing strategies for improving patient outcomes. The Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, MEDLINE, PubMed, Cumulative Index to Nursing and Allied Health (CINAHL), Google Scholar, and EMBASE were searched to identify articles for systematic review. This review of relevant peer-reviewed literature provided evidence that the biomechanics related to OCA transplantation in the knee have direct and indirect effects on functional graft survival and patient outcomes. The evidence suggests that biomechanical variables can be optimized further to enhance benefits and mitigate detrimental effects. Each of these modifiable variables should be considered regarding indications, patient selection criteria, graft preservation methodology, graft preparation, transplantation, fixation techniques, and prescribed postoperative restriction and rehabilitation protocols. Criteria, methods, techniques, and protocols should target OCA quality (chondrocyte viability, extracellular matrix integrity, material properties), favorable patient and joint characteristics, rigid fixation with protected loading, and innovative ways to foster rapid and complete OCA cartilage and bone integration to optimize outcomes for OCA transplant patients.

Comparison of Outcomes After Primary Versus Salvage Osteochondral Allograft Transplantation for Femoral Condyle Osteochondritis Dissecans Lesions.

Background: Osteochondral allograft transplantation (OCAT) allows the restoration of femoral condyle osteochondritis dissecans (OCD) lesions using an osteochondral unit. When OCD lesions are irreparable, or treatments have failed, OCAT is an appropriate approach for revision or salvage surgery. Based on its relative availability, cost-effectiveness, lack of donor site morbidity, and advances in preservation methods, OCAT is also an attractive option for primary surgical treatment for femoral condyle OCD. Hypothesis: OCAT for large femoral condyle OCD lesions would be highly successful (>90%) based on significant improvements in knee pain and function, with no significant differences between primary and salvage procedure outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Patients were enrolled into a registry for assessing outcomes after OCAT. Those patients who underwent OCAT for femoral condyle OCD and had a minimum of 2-year follow-up were included. Reoperations, treatment failures, and patient-reported outcomes were compared between primary and salvage OCAT cohorts. Results: A total of 22 consecutive patients were included for analysis, with none lost to the 2-year follow-up (mean, 40.3 months; range, 24-82 months). OCD lesions of the medial femoral condyle (n = 17), lateral femoral condyle (n = 4), or both condyles (n = 1) were analyzed. The mean patient age was 25.3 years (range, 12-50 years), and the mean body mass index was 25.2 kg/m2 (range, 17-42 kg/m2). No statistically significant differences were observed between the primary (n = 11) and salvage (n = 11) OCAT cohorts in patient and surgical characteristics. Also, 91% of patients had successful outcomes at a mean of >3 years after OCAT with 1 revision in the primary OCAT cohort and 1 conversion to total knee arthroplasty in the salvage OCAT cohort. For both primary and salvage OCATs, patient-reported measures of pain and function significantly improved at the 1-year and final follow-up, and >90% of patients reported that they were satisfied and would choose OCAT again for treatment. Conclusion: Based on the low treatment failure rates in conjunction with statistically significant and clinically meaningful improvements in patient-reported outcomes, OCAT can be considered an appropriate option for both primary and salvage surgical treatment in patients with irreparable OCD lesions of the femoral condyles.

Treatment failures (revision or arthroplasty) after knee osteochondral allograft transplantation with minimum two-year follow-up.

BACKGROUND: Knee osteochondral allograft transplantation (OCAT) has been associated with good short- to mid-term outcomes, however, treatment failures occur more frequently than desired. This study used data from a lifelong outcomes registry to analyze knee OCAT treatment failure rates, variables associated with knee OCAT treatment failures, and outcomes after revision or arthroplasty surgery for knee OCAT treatment failures. METHODS: Patient outcomes were followed after knee OCAT performed using standard preservation (SP) or Missouri Osteochondral Preservation System (MOPS®) allografts. The study population consisted of patients undergoing primary OCAT with ≥ 2-year follow-up. For comparisons, the treatment failure population was defined by patients in the study population with documented treatment failure (revision or arthroplasty) with ≥ 2-year follow-up after failure. Functional graft survival was defined as no further need for revision surgery after primary or revision OCAT. RESULTS: A total of 262 patients (n = 136 males; 51.9%) were analyzed. SP grafts were used for 59 cases and MOPS grafts were used for 203 cases. Treatment failure was documented in 61 cases (23.3%). MOPS grafts were 3.3 times more likely to be associated with functional graft survival. SP grafts, older patient age, higher BMI, tibiofemoral bipolar OCAT and non-adherence to the postoperative rehabilitation protocol were significantly associated with treatment failure. CONCLUSIONS: Knee OCAT resulted in functional graft survival at short- to mid-term follow-up in the majority (70-88%) of cases. In addition, revision of primary OCAT resulted in functional graft survival for at least 2 years after revision surgery in the majority (66%) of patients. LEVEL OF EVIDENCE: 2, prospective cohort study.

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.