Faculty Bibliography

INTRODUCTION: Recurrent patellar instability can be a source of continued pain and functional limitation in the young, active patient population. Instability in the setting of an elevated tibial tubercle-trochlear groove (TT-TG) distance can be effectively managed with a tibial tubercle osteotomy. At the present time, clinical outcome data are limited with respect to this surgical approach to patellar instability. METHODS: A retrospective chart review was performed to identify all cases of tibial tubercle osteotomy for the management of patellar instability performed at our institution with at least 1 year of post-operative follow-up. Patient demographic information was collected along with relevant operative data. Each patient was evaluated post-operatively with their outcomes assessed utilising a visual analogue score of pain, patient satisfaction, Tegner Activity Scale and Kujala score. RESULTS: 31 patients (23 females and 8 males) with mean age of 27 years (17-43 years) and a mean BMI of 26.3kg/m(2) (19.6-35.8) at time of surgery who underwent a tibial tubercle osteotomy as treatment for recurrent patellar instability were identified. The cohort had a mean follow up of 4.4 years (1.5-11.8 years). The mean pre-operative TT-TG distance was 18mm (10-22mm). The mean VAS pain score demonstrated a significant improvement from 6.8 (95% CI 6.1-7.5) at baseline to 2.8 (95% CI 1.9-3.7) post-operatively (p<0.001). The Tegner score improved from 4.1 (95% CI 3.4-4.8) pre-operatively to 5.2 (95% CI 4.5-5.9) at the time of final follow up (p<0.04). The Kujala score for anterior knee pain improved postoperatively from 62 (95% CI 55.4-68.7) to 76.5 (95% CI 69.5-83.5) at final follow up (p<0.001). 26 of the 31 patients (83.8%) had good to excellent Kujala scores. 27 of 31 patients (87.1%) reported that they would undergo the procedure again if necessary. CONCLUSION: For the management of recurrent patellar instability in the setting of an increased tibial tubercle-trochlear groove distance, a corrective tibial tubercle osteotomy is an effective treatment modality to reliably prevent patellar instability while reducing pain and improving function in this cohort of young, active patients.

PURPOSE: To correlate the intraoperative concentrations of 20 synovial fluid biomarkers with preoperative symptoms, intraoperative findings, and postoperative outcomes in patients undergoing knee arthroscopy, with comparisons made to samples obtained from asymptomatic knees. METHODS: Synovial fluid samples were obtained from 81 patients undergoing knee arthroscopy meeting the inclusion criteria, which included 70 samples from operative knees and 32 samples from contralateral knees. Preoperatively, baseline data obtained from clinical questionnaires including a visual analog scale (VAS) score, the Lysholm score, and the Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form were recorded. Synovial fluid was collected from both the operative knee and asymptomatic contralateral knee. Synovial fluid was stored with a protease inhibitor at -80 degrees C until analysis. Intraoperative findings, procedures performed, and International Cartilage Repair Society (ICRS) cartilage status scores in all operative knees were documented. The concentrations of the following 20 biomarkers were measured using a multiplex magnetic bead immunoassay: matrix metalloproteinase (MMP) 3; MMP-13; tissue inhibitor of metalloproteinase (TIMP) 1; TIMP-2; TIMP-3; TIMP-4; fibroblast growth factor 2; eotaxin; interferon gamma; interleukin (IL) 10; platelet-derived growth factor BB; IL-1 receptor antagonist; IL-1beta; IL-6; monocyte chemotactic protein 1 (MCP-1); macrophage inflammatory protein 1alpha; macrophage inflammatory protein 1beta; RANTES (regulated upon activation, normal T cell expressed and secreted); tumor necrosis factor alpha; and vascular endothelial growth factor. Clinical outcome scores were obtained in 83% of patients at a mean of 17 months' follow-up postoperatively. Analysis of variance and Pearson correlation analysis were performed to determine statistical significance between preoperative data, intraoperative findings, postoperative outcomes, and synovial fluid biomarker concentrations compared with asymptomatic contralateral knees. RESULTS: Analysis was performed on 70 operative and 32 contralateral samples. There were strong positive correlations between ICRS score and age, symptom duration, VAS score, and Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form. A strong positive correlation was found between MCP-1 and IL-6 concentrations, intraoperative ICRS score, and continued pain at the time of final follow-up. MCP-1 and IL-6 were the strongest predictors of severe cartilage lesions, whereas IL-1 receptor antagonist was inversely related. MMP-3 levels were consistently elevated in all operative samples and directly correlated to increased preoperative VAS scores. RANTES, vascular endothelial growth factor, and platelet-derived growth factor BB were the strongest predictors of postoperative improvement at final follow-up regardless of injury and cartilage status. CONCLUSIONS: Synovial fluid biomarkers have the capacity to reflect the intra-articular environment before surgery and potentially predict postoperative clinical outcomes. Recognition of key molecular players may yield future therapeutic targets, and large clinical trials exploring these discoveries are anticipated. LEVEL OF EVIDENCE: Level III, therapeutic case-control study.

Bone marrow edema of the knee occurs secondary to a myriad of causes. The hallmark of a bone marrow lesion (BML) is an area of decreased signal intensity on T1 weighted MRI with a corresponding area of increased signal intensity on a T2 weighted MRI. Recently, chronic bone marrow lesions have been correlated with knee pain and progression of osteoarthritis. These lesions have also been associated with other degenerative conditions such as meniscal tears, cartilage deterioration, subchondral cyst formation, mechanical malalignment, and ultimately progression to arthroplasty. Medical treatments, such as prostacyclin and bisphosphonate therapy, have shown promise. Alignment procedures, as well as core decompression and subchondroplasty, have been used as surgical treatments for chronic BMLs.

Anterior cruciate ligament (ACL) injuries are common among all participants in sports, occurring in approximately 1 in 3,000 individuals yearly in the USA. Epidemiological studies of ACL injuries have demonstrated that females are at higher risk for injury than males. When compared to male athletes participating in the same sports, the risk of ACL injury is two to eight times greater in females.1-3 A significant research effort has been directed at identifying risk factors that may predispose females to ACL injury. Female athletes likely have an increased incidence of ACL injury due to anatomic, hormonal, biomechanical, and neuromuscular differences between the sexes. Extrinsic factors may also play a role. As the number of girls and women participating in athletics continues to increase, understanding risk factors and developing prevention strategies will have profound physical, psychological, and financial implications for female athletes and the medical system.

Injuries to the pectoralis major muscle are relatively rare but result in pain, weakness, cosmetic deformity and in many cases, inability to return to previous levels of function. The most common cause of this injury is bench-pressing, as it places the muscle fibers in a position of mechanical disadvantage while under heavy load. The ability to detect and appropriately treat each patient with this injury is essential to restoring not only strength and function but also cosmesis. This article reviews the diagnostic workup of this injury and examines both the outcomes and techniques of non-operative and operative management.

Anterior cruciate ligament (ACL) rupture is a common injury that mostly affects young adults. The mechanisms of injury and surgical treatment have been extensively studied in both the laboratory and clinical arenas; however, great controversy still exists in regards to the best surgical technique, graft choice, and graft fixation device. In the area graft fixation, multiple breakthroughs have occurred in terms of fixation devices. These devices generally fall within the broad categories of interference screw, cross-pins, or cortical-based devices. Furthermore, some of these devices are available in either metal or bioabsorbable materials, which adds to the already great variety of options. Although biomechanically these devices have been shown to be able to withstand the typical forces experienced by the ACL graft during the early phases of rehabilitation before the graft has fully incorporated into the bone, little is known about the clinical outcomes. It is well recognized that graft fixation is the weakest link in the early postoperative period after ACL reconstruction. This review of the outcomes of ACL fixation devices explores some of the evidence available for the different devices.

The purpose of the current study was to determine if the application of platelet-rich fibrin matrix could improve regeneration of the tendon-bone insertion site in a rat rotator cuff repair model. 25 Lewis syngeneic rats underwent bilateral tenotomy and repair of the supraspinatus tendon. 10 separate rats were used for PRFM harvest. All left (control) shoulders underwent transosseous rotator cuff repair, while all right (treatment) shoulders were repaired similarly with PRFM augmentation. 9 rats were sacrificed at 2-weeks and ten at 4-weeks for biomechanical testing. 3 separate rats were sacrificed at 2-weeks and 4-weeks each for histologic analysis of the insertion site. At 2 weeks, the experimental group repairs were significantly stronger in ultimate load to failure (P=0.01), stress (P=0.03), and stiffness (P=0.03). Differences in biomechanical testing were not found between the groups at 4 weeks. Histological analysis revealed less collagen organization and cartilage formation at the insertion site in the experimental group. Semiquantitative histologic analysis confirmed our qualitative assessment of the specimens. PRFM does not recapitulate the native enthesis, but rather induces an exuberant and disordered healing response that is characterized by fibrovascular scar tissue.

OBJECTIVES: The objective of the current study was to evaluate the accuracy and precision of femoral and tibial tunnel placement during anterior cruciate ligament reconstruction (ACLR) using independent anteromedial portal (AMP) drilling over a three-year observation period. METHODS: This study was a retrospective review of 161 consecutive primary ACL reconstructions from a single surgeon over his first 36-months in practice. Femoral and tibial tunnel angulation measurements were made on anteroposterior radiographs by a single observer utilizing the assessment method described by Aglietti et al. The accuracy and precision of tunnel placement across the three-year period were assessed with comparisons made. RESULTS: Significantly improved accuracy was demonstrated toward the cadaveric ideal femoral tunnel angle of 33.5 degrees over time. Improved precision of tunnel placement was also demonstrated evidenced by declining standard deviations across each year. Statistically significant improvement in femoral tunnel placement was seen between the first and second cohorts of 32 cases. No significant change was seen with respect to tibial tunnel angle across the observation period. CONCLUSIONS: A learning curve in developing accuracy and precision in ACL femoral tunnel placement using the AMP technique exists; our study indicates this to be somewhere between 32 and 64 cases. Tibial tunnel placement does not share the same learning curve using this surgical technique.

INTRODUCTION: Though outcomes following ACL reconstruction are largely positive, patients' post-operative recovery is highly variable, and is typically based off generalized timetables derived from population data. In an attempt to individualize prognostic estimates and establish how biomarker concentrations may change with injury, we sampled knee joint synovial fluid from patients with ACL tears with and without associated cartilage injuries and compared biomarker concentrations to samples obtained from the contralateral non-injured knee. Method: In an institutional review board approved study, 480 patients indicated for knee arthroscopy were consented and had samples drawn to form a synovial fluid database. If no injury history or symptoms were present in the contralateral knee, samples were drawn as well. For the current study, only patients that had confirmed ACL injury at the time of arthroscopy were included. Associated cartilage injury location, size and depth was documented. Synovial fluid samples were centrifuged, and the concentrations of 20 biomarkers were determined using a multiplex magnetic bead immunoassay. Concentrations were then compared between the three study groups (ACL tear with cartilage injury, ACL tears without cartilage injury, and healthy contralateral knees) using a Welch ANOVA test with pairwise comparisons. Results: The study included samples from 132 knees: 34 ACL tears without cartilage injury (mean age 34.0 years); 28 ACL tears with cartilage injury (mean age 36.3 years), and 72 contralateral knees (41.1 years). ANOVA testing demonstrated significant differences among groups for: MMP-3 (p>001); TIMP-1 (p=.001); TIMP-2 (p=.015); FGF-2 (p=.011); IL-6 (p=.001); and MlP-lb (p=001). Pairwise comparisons demonstrated no significant differences between ACL tears with, and without cartilage damage, but did show both types of ACL tears had significantly higher concentrations of MMP-3, TIMP-1, IL-6, and MlP-lb than contralaterals. ACL tears without cartilage damage had significantly lower concentrations of TIMP-2 and FGF-2 (13) than contralaterals (Table 1). Discussion: The course from surgery to symptomatic relief and functional improvement following ACL reconstruction is highly variable. Data from the current study demonstrated that cytokine concentrations are significantly different between ACL tears (+/- cartilage damage) and healthy knees. SIGNIFICANCE: These validated differences can help establish synovial fluid biomarker analysis as a method for injury stratification ultimately providing patient-specific prognostic data