Inflammatory synovial biomarkers and state of the tibiofemoral joint in the post-surgical settings: a narrative review.

Background and Objective: Knee surgery attempts to restore the native biomechanics of the knee, improve stability, and decrease the progression of osteoarthritis (OA). However, despite improvements in surgical techniques, tissue degradation and OA are common after knee surgery, occurring in higher rates in surgical knees compared to non-surgical knees. The aim of this study is to analyze previous literature to determine which synovial fluid biomarkers contribute to knee tissue degradation and decrease patient outcomes in the post-surgical setting of the knee. Methods: A narrative review of relevant literature was performed in July 2023. Studies reporting on synovial biomarkers associated with the post-surgical knee were included. Key Content and Findings: The literature reported that proinflammatory synovial biomarkers cause cartilage degradation and turnover which eventually leads to OA. The associated biomarkers are typically present prior to physical symptoms so understanding which one's correlate to OA is important for potential therapeutic treatments in the future. Studying the preoperative, early postoperative, and late postoperative synovial biomarkers will allow physicians to develop an improved understanding of how these biomarkers progress and correlate to knee tissue degradation and OA. This understanding could lead to further developments into potential treatment options. Research into inhibiting or reversing these inflammatory biomarkers to slow the progression of knee tissue degradation has already begun and has reported some promising results but is currently limited in scope. Conclusions: Synovial fluid biomarkers in the post-surgical knee setting may contribute to decreased patient outcomes and the progression of knee tissue degradation. There is no current consensus on which of these biomarkers are the most detrimental or associated with decreased patient outcomes. With an improved understanding of the individual biomarkers, potential personalized therapeutic treatment could be used by physicians in the future to improve patient outcomes after surgery.

Effect of anti-inflammatory treatments on patient outcomes and concentrations of inflammatory modulators in the post-surgical and post-traumatic tibiofemoral joint setting: a narrative review.

Background and Objective: There are several anti-inflammatory therapeutic options that can be used in the context of post-surgical and post-traumatic knee settings. Each of these options carries with it certain benefits, as well as potential issues depending on the duration and administration of each therapy. An understanding of how these anti-inflammatory drugs modulate various biomarkers of inflammation is also necessary in understanding how they can affect patient and objective outcomes following acute knee injury or surgery. This review covers the many traditional therapeutic options that have been used in treating knee injuries, as well as some natural therapeutics that have shown anti-inflammatory properties. Methods: A current review of the literature was conducted and synthesized into this narrative review. Key Content and Findings: Many traditional anti-inflammatory therapeutics have been shown to be beneficial in both post-traumatic and post-surgical tibiofemoral joint settings at reducing inflammation and improving patient outcomes. However, many of these treatments have risks associated with them, which becomes problematic with prolonged, repeated administration. Natural anti-inflammatory compounds may also have some benefit as adjunctive treatment options in these settings. Conclusions: There are multiple different therapeutic options that can be used in acute knee settings, but the specific mechanism of injury or surgical context should be weighed when determining the best clinical approach.

Comparative Outcomes Occur After Superficial Medial Collateral Ligament Augmented Repair vs Reconstruction: A Prospective Multicenter Randomized Controlled Equivalence Trial.

BACKGROUND: Although previous studies have reported good short-term results for superficial medial collateral ligament (sMCL) reconstruction, whether an augmented MCL repair is clinically equivalent remains unclear. PURPOSE/HYPOTHESIS: The purpose of this study was to compare clinical outcomes between randomized groups that underwent sMCL augmentation repair and sMCL autograft reconstruction. The hypothesis was that there would be no significant differences in objective or subjective outcomes between groups. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Patients were prospectively enrolled between 2013 and 2019 from 3 centers. Grade III sMCL injuries were confirmed via stress radiography. Patients were randomized to anatomic sMCL reconstruction versus augmented repair with surgical treatment, determined after examination under anesthesia confirmed sMCL incompetence. Postoperative visits occurred at 6 weeks and 6 months for repeat evaluation, with repeat stress radiography at final follow-up. Patient-reported outcome measures were obtained pre- and postoperatively at 6 months, 1 year, and final follow-up. The primary outcome measure was side-to-side difference on valgus stress radiographs at a minimum follow-up of 1 year. The two 1-sided t test procedure was used to test clinical equivalence for side-to-side difference in valgus gapping, and the Mann-Whitney U test was used to compare postoperative patient-reported outcome measures between groups. RESULTS: A total of 54 patients were prospectively enrolled into this study. Of these, 50 patients had 6-month stress radiograph data, while 40 had 1-year postoperative valgus stress radiograph data. The mean (SD) patient age was 38.0 years (14.2), and body mass index was 25.0 (3.6). Preoperative valgus stress radiographs demonstrated 3.74 mm (1.1 mm) of increased side-to-side gapping overall, while it was 4.10 mm (1.46 mm) in the MCL augmentation group and 3.42 mm (0.55 mm) in the MCL reconstruction group. Postoperative valgus stress radiographs at an average of 6 months were obtained in 50 patients after surgery, which showed 0.21 mm (0.81 mm) for the MCL augmentation group and 0.19 mm (0.67 mm) for the MCL reconstruction group (P = .940). At final follow-up (minimum 1 year), median (interquartile range) Lysholm scores were significantly higher in the reconstruction group (90 [83-99]) as compared with the repair group (80 [67-92]) (P = .031). Final International Knee Documentation Committee (IKDC) scores were also significantly higher for the reconstruction group (85 [68-89]) versus the repair group (72 [60-78] (P = .039). Postoperative Tegner scores were not significantly different between the repair group (5 [3.5-6]) and the reconstruction group (5.5 [4-7]) (P = .123). Patient satisfaction was also not significantly different between repair (7.5 [5.75-9.25]) and reconstruction groups (9.0 [7-10]) (P = .184). CONCLUSION: This study found no difference in objective outcomes between an sMCL augmentation repair and a complete sMCL reconstruction at 1 year postoperatively, indicating equivalence between these procedures. Patient-reported clinical outcomes favored the reconstruction over a repair. In addition, this study demonstrated that anatomic-based treatment of MCL tears with an early knee motion program had a very low risk of graft attenuation and a low risk of arthrofibrosis.

Increased posterior tibial slope results in increased incidence of posterior lateral meniscal root tears in ACL reconstruction patients.

PURPOSE: While the association with acute anterior cruciate ligament (ACL) tears has been established, other risk factors and associated pathologies which occur with a concomitant lateral meniscal posterior root tear (LMPRT) are not well defined. The purpose of this study was to compare the risk factors and concomitant pathologies between patients with LMPRT and patients without LMPRTs in the setting of a primary ACL tear. METHODS: Patients with a LMPRT identified at the time of primary ACL reconstruction by a single surgeon were identified. These patients were matched by age and sex to patients undergoing primary ACL reconstruction who were not found to have lateral meniscus root tears (control group) in a 1:1 ratio. Lateral posterior tibial slope (PTS), medial PTS, lateral femoral condyle height and depth, lateral tibial plateau depth, and lateral tibial plateau subluxation were measured on MRI. Anteroposterior full-limb alignment radiographs were used to measure the medial proximal tibia angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical weightbearing axis for the injured extremity. RESULTS: One-hundred three patients were included in both the LMPRT group and the matched control group. Patients with a LMPRT had a significantly steeper lateral PTS (9.1° vs. 7.0°, p = 0.001), a steeper medial PTS (7.0° vs. 6.0°, p = 0.03), and a greater lateral-to-medial slope asymmetry (2.0° vs. 1.0°, p = 0.001). There were no differences in lateral femoral condyle depth or height, lateral tibial plateau depth, lateral tibial plateau subluxation, MPTA, mLDFA, or mechanical weightbearing axis between groups. There was a significantly increased incidence of medial meniscus ramp lesions in patients with lateral meniscus posterior root tears compared with controls (34.0% vs. 15.5%, odds ratio: 2.8, p = 0.002). There were no associations with concomitant ligament injuries, medial meniscus root tears, or non-ramp tears based on case/control grouping. CONCLUSION: In conclusion, LMPRTs in the setting of primary ACL injuries were associated with significantly increased lateral and medial PTSs, and increased asymmetry between lateral and medial PTSs. In addition, clinicians should be aware of the increased incidence of concurrent medial meniscal ramp lesions in patients with LMPRTs. Knowledge of these associations helps guide clinical decision-making and counselling of patients in the setting of ACL tears with concomitant LMPRTs. LEVEL OF EVIDENCE: IV.

Beighton Score, Tibial Slope, Tibial Subluxation, Quadriceps Circumference Difference, and Family History Are Risk Factors for Anterior Cruciate Ligament Graft Failure: A Retrospective Comparison of Primary and Revision Anterior Cruciate Ligament Reconstructions.

PURPOSE: To assess patient history, physical examination findings, magnetic resonance imaging (MRI) and 3-dimensional computed tomographic (3D CT) measurements of those with anterior cruciate ligament (ACL) graft failure compared with primary ACL tear patients to better discern risk factors for ACL graft failure. METHODS: We performed a retrospective review comparing patients who underwent revision ACL reconstruction (ACLR) with a primary ACLR group with minimum 1-year follow-up. Preoperative history, examination, and imaging data were collected and compared. Measurements were made on MRI, plain radiographs, and 3D CT. Inclusion criteria were patients who underwent primary ACLR by a single surgeon at a single center with minimum 1-year follow-up or ACL graft failure with revision ACLR performed by the same surgeon. RESULTS: A total of 109 primary ACLR patients, mean age 33.7 years (range 15 to 71), enrolled between July 2016 and July 2018 and 90 revision ACLR patients, mean age 32.9 years (range 16 to 65), were included. The revision ACLR group had increased Beighton score (4 versus 0; P < .001) and greater side-to-side differences in quadricep circumference (2 versus 0 cm; P < .001) compared with the primary ACLR group. A family history of ACL tear was significantly more likely in the revision group (47.8% versus 16.5%; P < .001). The revision group exhibited significantly increased lateral posterior tibial slope (7.9° versus 6.2°), anterolateral tibial subluxation (7.1 versus 4.9 mm), and anteromedial tibia subluxation (2.7 versus 0.5 mm; all P < .005). In the revision group, femoral tunnel malposition occurred in 66.7% in the deep-shallow position and 33.3% in the high-low position. The rate of tibial tunnel malposition was 9.7% from medial to lateral and 54.2% from anterior to posterior. Fifty-six patients (77.8%) had tunnel malposition in ≥2 positions. Allograft tissue was used for the index ACLR in 28% in the revision group compared with 14.7% in the primary group. CONCLUSION: Beighton score, quadriceps circumference side-to-side difference, family history of ACL tear, lateral posterior tibial slope, anterolateral tibial subluxation, and anteromedial tibia subluxation were all significantly different between primary and revision ACLR groups. In addition, there was a high rate of tunnel malposition in the revision ACLR group.

Global Forum: Orthopaedic Physicians in the Winter and Summer Olympic Games.

In training for and performing in the sporting competitions of the Olympic Games, athletes endure a variety of injuries that can lead to the development of a chronic musculoskeletal condition. Injury surveillance studies are in place for each event to collect epidemiological data in an attempt to enhance injury prevention for future Winter and Summer Olympic Games. Periodic health evaluations also are used to screen for injuries and monitor athletes' health in order to take measures to reduce the risk of reinjury. Orthopaedic physicians work to improve sport-specific injury prevention protocols to create a safe environment for competition and ultimately reduce the occurrence of injuries throughout the Olympic Games.

Clinical Characteristics and Outcomes After Anatomic Reconstruction of the Proximal Tibiofibular Joint.

PURPOSE: To assess the most common presenting symptoms, clinical outcomes, and satisfaction after anatomic reconstruction of the proximal tibiofibular joint (PTFJ) with a free semitendinosus autograft. METHODS: Consecutive patients with minimum 2-year follow-up after isolated anatomic PTFJ reconstruction were retrospectively reviewed. Patients were evaluated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and Lysholm Knee Survey score along with a simple numeric patient satisfaction score (0-10, with 10 rated as perfect). Statistical analysis was performed with paired t tests, with P < .05 considered significant. RESULTS: The study included 16 PTFJ reconstruction surgical procedures in 15 patients with isolated proximal tibiofibular instability verified by an examination under anesthesia (4 reconstructions in male patients vs 12 in female patients); the average age was 37.9 ± 14.6 years, with an average follow-up period of 43.2 months (range, 22-72 months). Of the 13 patients with complete follow-up, 11 (84.6%) were able to return to full desired activities and previous level of sport. Fourteen patients presented with concomitant common peroneal nerve pathology. Two patients had a subsequent complication. No patients needed an additional procedure. Significant (P < .05) improvement occurred across all WOMAC domains and in the WOMAC total score, from 31.4 (±14.9) preoperatively to 15.2 (±15.5) postoperatively. Lysholm Knee Survey scores significantly (P < .05) improved from 51.2 (±17.2) to 75.0 (±18.0). Patients' overall satisfaction was rated 7.6 (± 2.7) of 10. CONCLUSIONS: At an average follow-up of 43.2 months, anatomic PTFJ reconstruction for isolated PTFJ instability provided improvement in clinical outcomes, a return to activities, and a low risk of complications or need for additional procedures. CLINICAL RELEVANCE: PTFJ reconstruction with hamstring tendon graft is a promising surgical treatment that improves patient satisfaction when conservative treatment of PTFJ instability fails. LEVEL OF EVIDENCE: Level IV, case series.

Injury of the Meniscus Root.

Meniscus root tears biomechanically disrupt normal joint loading and lead to joint overload with the possible development of spontaneous osteonecrosis of the knee and early-onset osteoarthritis. Proper identification and treatment of meniscal root tears has been proven to restore joint loading and improve patient outcomes.

Low-Profile Dual Small Plate Fixation Is Biomechanically Similar to Larger Superior or Anteroinferior Single Plate Fixation of Midshaft Clavicle Fractures.

BACKGROUND: Limited biomechanical data exist for dual small plate fixation of midshaft clavicle fractures, and no prior study has concurrently compared dual small plating to larger superior or anteroinferior single plate and screw constructs. PURPOSE: To biomechanically compare dual small orthogonal plating, superior plating, and anteroinferior plating of midshaft clavicle fractures by use of a cadaveric model. STUDY DESIGN: Descriptive laboratory study. METHODS: The study used 18 cadaveric clavicle specimens (9 pairs total), and 3 plating techniques were studied: anteroinferior, superior, and dual. The dual plating technique used smaller diameter plates and screws (1.6-mm thickness) than the other, single plate techniques (3.3-mm thickness). Each of the 9 clavicle pairs was randomly assigned a combination of 2 plating techniques, and randomization was used to determine which techniques were used for the right and left specimens. Clavicles were plated and then osteotomized to create an inferior butterfly fracture model, which was then fixed with a single interfragmentary screw. Clavicle specimens were then potted for mechanical testing. Initial bending, axial, and torsional stiffness of each construct was determined through use of a randomized nondestructive cyclic testing protocol followed by load to failure. RESULTS: No significant differences were found in cyclical axial (P = .667) or torsional (P = .526) stiffness between plating groups. Anteroinferior plating demonstrated significantly higher cyclical bending stiffness than superior plating (P = .005). No significant difference was found in bending stiffness between dual plating and either anteroinferior (P = .129) or superior plating (P = .067). No significant difference was noted in load to failure among plating methods (P = .353). CONCLUSION: Dual plating with a smaller plate-screw construct is biomechanically similar to superior and anteroinferior single plate fixation that uses larger plate-screw constructs. No significant differences were found between dual plating and either superior or anteroinferior single plating in axial, bending, or torsional stiffness or in bending load to failure. Dual small plating is a viable option for fixing midshaft clavicle fractures and may be a useful low-profile technique that avoids a larger and more prominent plate-screw construct. CLINICAL RELEVANCE: Plate prominence and hardware irritation are commonly reported complaints and reasons for revision surgery after plate fixation of midshaft clavicle fractures. Dual small plate fixation has been used to improve cosmetic acceptability, minimize hardware irritation, and decrease reoperation rate. Biomechanically, dual small plate fixation performed similarly to larger single plate fixation in this cadaveric model of butterfly fracture.

Single-Stage Multiple-Ligament Knee Reconstructions for Sports-Related Injuries: Outcomes in 194 Patients.

BACKGROUND: Outcomes after sports-related multiple-ligament knee reconstructions are limited. PURPOSE: To evaluate outcomes after single-stage surgical treatment of sports-related multiple-ligament knee injuries and to compare outcomes after anterior cruciate ligament (ACL)-based and posterior cruciate ligament (PCL)-based multiple-ligament knee reconstructions. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Skeletally mature patients with at least 2 major knee ligaments torn during a sporting activity that required surgery with a minimum of 2 years' follow-up were included. The Lysholm score, Tegner activity scale, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 12-Item Short Form Health Survey Physical Component Summary were collected preoperatively and at a minimum of 2 years' follow-up. Clinical data, including range of motion and knee stability, were also recorded at final follow-up. RESULTS: A total of 276 patients with multiple-ligament knee injuries incurred during sport participation from 2010 to 2016 were identified. Of the 276 patients, 194 (70.5%) had complete follow-up at a mean 3.5 years (range, 2-8 years). There was a significant improvement in all outcome scores as compared with the preoperative scores (P < .001 for all scores). The median (first and third quartiles) Tegner activity score improved from 1 (0, 2) preoperatively to 6 (4, 7) postoperatively. Significant improvements were from 41 (22, 57) to 90 (78, 95) and 44 (24, 60) to 3 (1, 8) for median Lysholm and WOMAC scores, respectively. There was no significant difference in postoperative outcome scores between patients treated in the acute and chronic phases. Furthermore, there was no significant difference between PCL- and ACL-based multiple-ligament knee injuries. Eighteen (9.3%) patients developed arthrofibrosis requiring reintervention surgery. CONCLUSION: These results demonstrated that single-stage anatomic-based knee ligament reconstructions with immediate postoperative rehabilitation in the setting of sports-related multiligament injuries yielded significantly improved outcomes irrespective of the ligament injury pattern. In addition, there was no difference in outcomes between ACL- and PCL-based injuries in the setting of sports-related multiligament injuries.

Clinical Outcomes of Inside-Out Meniscal Repair According to Anatomic Zone of the Meniscal Tear.

BACKGROUND: There is significant discrepancy in the reported vascularity within the meniscus, and a progressively diminishing blood supply may indicate a differential healing capacity of tears that is dependent on the affected meniscal zone. PURPOSE: To examine the outcomes after inside-out meniscal repair in all 3 meniscal vascularity zones. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients were included if they underwent inside-out meniscal repair by a single surgeon between 2010 and 2014 and had a minimum 2-year follow-up. Patients were divided into 3 groups based on the meniscal tear location (red-red, red-white, and white-white zones) as determined during an intraoperative assessment. Patient-reported outcome scores were obtained at final follow-up. RESULTS: A total of 173 patients (mean age, 33.6 ± 14.3 years) were included, with a mean follow-up of 2.9 ± 0.9 years. All patients demonstrated significant improvements with inside-out meniscal repair from preoperatively to postoperatively, regardless of the meniscal tear location. Patients who underwent meniscal repair in the red-red and red-white zones had significantly increased postoperative Tegner, Lysholm, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores compared with patients who underwent meniscal repair in the white-white zone (P < .05). Patients who underwent acute repair (≤6 weeks) demonstrated significantly higher improvements on the Tegner activity scale (acute: 5.8 ± 2.2; chronic: 4.6 ± 2.2; P = .001) and Lysholm score (acute: 85.6 ± 13.3; chronic: 80.8 ± 13.5; P = .025) compared with patients treated beyond 6 weeks from injury, regardless of the meniscal tear zone. Patients with grade IV femoral condyle chondral lesions at the time of surgery had significantly inferior outcomes compared with patients with grade I through III chondral lesions, regardless of the meniscal tear zone. Three patients (1.7%) subsequently underwent revision inside-out repair, and 3 (1.7%) underwent partial meniscectomy. CONCLUSION: Patients who underwent inside-out meniscal repair demonstrated significant improvements on subjective outcome measures at a minimum 2-year follow-up, regardless of the meniscal tear zone. Inside-out meniscal repair is recommended for potentially reparable meniscal tears in all 3 vascular zones; however, improved outcomes can be achieved when performed acutely, in the absence of full-thickness femoral condyle chondral injuries, and in the red-red and red-white zones.

Variability of Reporting Recurrence After Arthroscopic Bankart Repair: A Call for a Standardized Study Design.

BACKGROUND: High recurrence rates have been reported after anterior shoulder dislocations, regardless of the treatment utilized. However, the definition of recurrent instability has been inconsistent, making a comparison between studies difficult. PURPOSE: To report on the nature with which the rate of recurrent instability is reported after arthroscopic Bankart repair, across all levels of evidence, and to analyze factors that may affect the reported rate of recurrence. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review of the literature was performed by searching PubMed, the Cochrane Central Register of Controlled Trials, Embase, and ClinicalTrials.gov for studies published within the dates of January 2008 and September 2018. Studies in English that reported on the recurrence of instability after arthroscopic Bankart repair for anterior shoulder instability were considered for inclusion in this review. A meta-regression was performed to test for a linear association between the reported recurrence rate and several continuous covariates, including mean age at surgery, mean length of follow-up, attrition rate (loss to follow-up percentage), and percentage of male patients. RESULTS: A trim-and-fill meta-analysis yielded an estimated overall recurrence rate of 17.4% (95% CI, 14.3%-20.9%). There was a significant difference in the recurrence rate depending on the level of evidence (Q(3) = 10.98; P = .012). Significant associations were found with the recurrence rate through the meta-regression, including a negative association with mean age (P = .009), a positive association with mean follow-up time (P = .002), and a positive association with attrition rate (P = .035). CONCLUSION: A call for standardization is necessary for reporting outcomes of anterior instability after arthroscopic Bankart repair, especially with regard to the reporting of recurrence/failure rates, with careful consideration of the effects that may occur from patient demographics and study design. With no current recommendations for deeming failure, we suggest that all forms of instability be accounted for when determining a failed treatment procedure, with future studies placing an emphasis on greater control of the study design.

Characterization of Growth Factors, Cytokines, and Chemokines in Bone Marrow Concentrate and Platelet-Rich Plasma: A Prospective Analysis.

BACKGROUND: Platelet-rich plasma (PRP) and bone marrow concentrate (BMC) are orthobiologic therapies with numerous growth factors and other bioactive molecules. Before the clinical utility of PRP and BMC is optimized as a combined therapy or monotherapy, an improved understanding of the components and respective concentrations is necessary. PURPOSE: To prospectively measure and compare anabolic, anti-inflammatory, and proinflammatory growth factors, cytokines, and chemokines in bone marrow aspirate (BMA), BMC, whole blood, leukocyte-poor PRP (LP-PRP), and leukocyte-rich PRP (LR-PRP) from samples collected and processed concurrently on the same day from patients presenting for elective knee surgery. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Patients presenting for elective knee surgery were prospectively enrolled over a 3-week period. Whole blood from peripheral venous draw and BMA from the posterior iliac crest were immediately processed via centrifugation and manual extraction methods to prepare LR-PRP, LP-PRP, and BMC samples, respectively. BMA, BMC, whole blood, LR-PRP, and LP-PRP samples were immediately assayed and analyzed to measure protein concentrations. RESULTS: BMC had a significantly higher interleukin 1 receptor antagonist (IL-1Ra) concentration than all other preparations (all P < .0009). LR-PRP also had a significantly higher IL-1Ra concentration than LP-PRP (P = .0006). There were no significant differences in IL-1Ra concentration based on age, sex, body mass index, or chronicity of injury in all preparations. LR-PRP had significantly higher concentrations of platelet-derived growth factor AA (PDGF-AA) and PDGF-AB/BB than all other preparations (all P < .0006). LR-PRP also had significantly higher concentrations of matrix metalloproteinase 1 (MMP-1) and soluble CD40 ligand than all other preparations (all P < .004). LP-PRP had significantly higher concentrations of MMPs, namely MMP-2, MMP-3, and MMP-12, than all other preparations (all P < .007). CONCLUSION: BMC is a clinically relevant source of anti-inflammatory biologic therapy that may be more effective in treating osteoarthritis and for use as an intra-articular biologic source for augmented healing in the postsurgical inflammatory and healing phases, owing to its significantly higher concentration of IL-1Ra as compared with LR-PRP and LP-PRP. Additionally, LR-PRP had a significantly higher concentration of IL-1Ra than LP-PRP. In cases where increased vascularity and healing are desired for pathological or injured tissues, including muscle and tendon, LR-PRP may be optimal given its higher overall concentrations of PDGF, TGF-ß, EGF, VEGF, and soluble CD40 ligand.

Patellar Tendon Tenotomy for Treatment of Patella Baja and Extension Deficiency.

Extension loss due to patella baja is a rare but devastating postoperative complication associated with knee surgery. The most common causes of patella baja are prolonged postoperative immobilization, over-distalization of the patellar tendon during patella-related surgical procedures (i.e., tibial tubercle osteotomy and patellar tendon reconstruction), and inadequate knee range-of-motion exercises postoperatively. Patella baja can cause significant functional limitations owing to knee-related stiffness, pain, and weakness. Arthroscopy with scar tissue debridement is the standard of care for patients with arthrofibrosis in whom conservative treatment has failed. However, when this surgical approach fails, patients with continued patella baja may be candidates for open patellar tendon tenotomy as a salvage procedure.

Fibular Collateral Ligament/ Posterolateral Corner Injury: When to Repair, Reconstruct, or Both.

The posterolateral corner (PLC) of the knee was regarded as the "dark side" of the knee because of limited understanding of its anatomy and biomechanics and because of poor outcomes after injuries to PLC structures. These injuries rarely occur in isolation, with 28% reported as isolated PLC injuries. Nonoperative treatment of these injuries has led to persistent instability, development of early osteoarthritis, and poor outcomes. Several techniques for reconstruction of the PLC have been described, and all are reported to improve outcomes. Biomechanically validated anatomic reconstructions are preferred because they restore native knee kinematics and improve clinical outcomes without over-constraining the knee.

Decreased Posterior Tibial Slope Does Not Affect Postoperative Posterior Knee Laxity After Double-Bundle Posterior Cruciate Ligament Reconstruction.

BACKGROUND: Recent clinical studies identified sagittal plane posterior tibial slope as a risk factor for increased postoperative laxity after single-bundle posterior cruciate ligament reconstruction (PCLR). PURPOSE/HYPOTHESIS: To retrospectively compare the degree of posterior tibial slope and its effect on posterior tibial translation (PTT) after double-bundle (DB) PCLR. Our null hypothesis was that preoperative tibial slope would not be associated with graft laxity. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent DB PCLR between 2010 and 2017 by a single surgeon were retrospectively analyzed. Measurements of posterior tibial slope were performed on lateral radiographs, and PTT was measured with pre- and postoperative kneeling stress radiographs. Simple and multiple linear regression was performed to estimate the unadjusted and adjusted effect of tibial slope on postoperative graft laxity, respectively. RESULTS: A total of 103 patients with posterior cruciate ligament tears and subsequent reconstructions were included. There was a significant reduction of the mean ± SD side-to-side difference in PTT between stress radiographs (preoperative, 10.6 ± 2.7 mm; postoperative, 1.5 ± 2.6 mm; mean difference, 9.1 mm; 95% CI, 8.4-9.8; P < .001). Linear regression analysis revealed no significant correlation between preoperative posterior tibial slope and the amount of side-to-side difference in PTT on postoperative stress radiographs obtained at a mean 18.5 months ( R = -0.115, P = .249). Combined ligament injury (beta = -1.01; 95% CI, -2.00 to -0.01; P = .047) was a significant independent predictor of decreased postoperative side-to-side difference in PTT. CONCLUSION: Graft laxity, determined by PTT in posterior kneeling stress radiographs, was not influenced by decreased posterior tibial slope after DB PCLRs. The observed results in the current study support the use of DB PCLR. Future studies should be conducted to compare the effect of tibial slope after SB PCLR and DB PCLR at long-term follow-up.

The Influence of Naproxen on Biological Factors in Leukocyte-Rich Platelet-Rich Plasma: A Prospective Comparative Study.

PURPOSE: To quantify and compare normative catabolic and anabolic factor concentrations in leukocyte-rich platelet-rich plasma (LR-PRP) at various time points, including baseline, 1 week after initiating naproxen use, and after a 1-week washout period. METHODS: Asymptomatic healthy donors aged between 18 and 70 years were recruited (average age, 36.6 years; range, 25-64 years). Subjects were excluded from the study if they were actively taking any prescribed medications or nonsteroidal anti-inflammatory drugs (NSAIDs) or if they had any of the following at present or previously: blood or immunosuppression disorders, cancer, osteonecrosis, rheumatoid arthritis, avascular necrosis, NSAID intolerance, gastrointestinal or peptic ulcer disease, or kidney dysfunction. The anabolic factors vascular endothelial growth factor, fibroblast growth factor 2, platelet-derived growth factor AB (PDGF-AB), and platelet-derived growth factor AA (PDGF-AA) and the catabolic factors interleukin (IL) 1ß, IL-6, IL-8, and tumor necrosis factor α in LR-PRP were measured. Peripheral blood was drawn at 3 time points: baseline, after 1 week of naproxen use, and after a 1-week washout period. RESULTS: The angiogenic factors PDGF-AA (44% decrease in median) and PDGF-AB (47% decrease) significantly declined from baseline (P < .05) after 1 week of naproxen use. There was a significant recovery (P < .05) of PDGF-AA (94% increase) and PDGF-AB (153% increase) levels after the 1-week washout period, with a return to baseline levels. The catabolic factor IL-6 also had a significant decline from baseline (77% decrease in median, P < .05) after 1 week of naproxen use. After a 1-week washout period, the IL-6 level was similar to the baseline level (130% increase, P < .05). CONCLUSIONS: Naproxen use diminished several biological factors in LR-PRP; however, a 1-week washout period was sufficient for the recovery of PDGF-AA, PDGF-AB, and IL-6 to return to baseline levels. Tumor necrosis factor α, IL-1ß, IL-8, vascular endothelial growth factor, and fibroblast growth factor 2 did not show differences between the 3 time points of data collection. Discontinuing NSAIDs for a minimum of 1 week before LR-PRP treatment may improve certain biological factor levels. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Ortho-Biologics for Ligament Repair and Reconstruction.

Biologics enhance tissue healing by stimulating the recovery processes for restoration of native or near-native tissue in addition to symptom management. The most popular biological modalities currently used include hyaluronic acid, growth factors therapy, platelet-rich plasma, and bone marrow aspirate concentrate. These treatment protocols are thought to facilitate and signal with cells or bioactive factors to improve ligament interventions by enhanced graft incorporation and strength, gene activation, and other mechanisms. Various growth factors regulate and improve cellular activities and proliferation, extracellular matrix deposition, and differentiation of mesenchymal stem cells into fibroblasts in the repair process of torn ligaments.

Blood Flow Restriction Therapy After Knee Surgery: Indications, Safety Considerations, and Postoperative Protocol.

Blood flow restriction (BFR) training involves occluding venous outflow while maintaining arterial inflow by the application of an extremity tourniquet after surgery. BFR ultimately reduces oxygen delivery to muscle cells, similar to an anaerobic environment, and allows patients to exercise with low resistance and stimulates muscle hypertrophy and strength using heavy resistance. Thus orthopaedic surgeons and physical therapists are incorporating this type of training into their postoperative rehabilitation protocols, particularly after injuries or surgical procedures about the knee joint. The purpose of this Technical Note is to describe a BFR clinical application technique and to report on the indications, safety considerations, and postoperative knee surgery rehabilitation protocols for BFR.

The Role of Blood Flow Restriction Therapy Following Knee Surgery: Expert Opinion.

Blood flow restriction (BFR) therapy is becoming increasingly popular in musculoskeletal injury rehabilitation. In particular, this form of therapy is being utilized more often in the postoperative setting following knee surgery, including anterior cruciate ligament reconstruction. BFR therapy provides patients and clinicians an alternative treatment option to standard muscle strengthening and hypertrophy guidelines in the setting of postoperative pain, weakness, and postoperative activity restrictions that contribute to muscle atrophy. The ability to complete exercise in a low load environment and achieve similar physiological adaptations as high-intensity strength training makes this modality appealing. With poor patient-related outcomes associated with continued muscle atrophy, pain, and muscle weakness, some researchers have investigated BFR training postoperatively following arthroscopic knee surgery with promising results. However, owing to the current paucity of research studies, inconsistency among reported protocols, and mixed results, it may be some time before a mass adoption of BFR therapy is made into the world of orthopaedic rehabilitation. Although the current data is inconclusive, we choose to utilize BFR in postoperative knee patients, regardless of weight-bearing status, for whom maintenance of existing muscle mass or improvement of decreased postoperative strength levels is important. Therefore, the purpose of this expert opinion is to review the background of BFR, describe the clinical evidence of BFR following knee surgery, and report the authors' current recommendations for application of BFR postoperatively.