Faculty Bibliography

RATIONALE AND OBJECTIVES: The objectives of this study were to investigate the changes in compartment-specific subchondral bone marrow lipids of femoral-tibial bone in acute anterior cruciate ligament (ACL)-injured patients compared to that of healthy volunteers and patients with osteoarthritis (OA) (Kellgren-Lawrence [KL] grade 2-3). MATERIALS AND METHODS: A total of 55 subjects were recruited in the study and subdivided into three subgroups: 17 healthy controls (4 females, 13 males; mean age = 41 +/- 16, age range 24-78 years), 17 patients with acute ACL injury (3 females, 14 males; mean age = 30 +/- 11, age range 18-61 years), and 21 patients with KL2-3 OA (12 females, 9 males; mean age = 65 +/- 12, age range 44-89 years). Routine clinical proton density-weighted fast spin echo images in sagittal (without fat saturation), axial, and coronal (fat saturation) planes were acquired on a 3 T clinical scanner for cartilage morphology using Whole-Organ Magnetic Resonance Imaging Score grading. A voxel of 10 x 10 x 10 mm3 was positioned in the medial and lateral compartments of the tibia and femur for proton magnetic resonance spectroscopy measurements using the single voxel stimulated echo acquisition mode pulse sequence. All proton magnetic resonance data were processed with Java-based magnetic resonance user interface. Wilcoxon rank sum test and mixed model two-way analysis of variance were performed to determine significant differences between different compartments and examine the effect of ACL injury, OA grade and compartment, and their interactions. RESULTS: The index of unsaturation in lateral tibial compartment in ACL-injured patients was significantly higher (P < .05) than all compartments except lateral femoral in patients with KL2-3 OA. Significantly lower values (P < .05) were also identified in saturated lipids at 2.03 ppm in all compartments in ACL-injured patients than those of all compartments in patients with KL2-3 OA. CONCLUSIONS: The preliminary results suggest that the indices of unsaturation in the lateral tibial compartment and the peaks of saturated lipids at 1.3 and 2.03 ppm in medial tibial compartment may be clinically useful to characterize subchondral bone marrow among healthy controls, acute ACL-injured patients, and patients with OA.

Tendon-to-bone healing is vital to the ultimate success of the various surgical procedures performed to repair injured tendons. Achieving tendon-to-bone healing that is functionally and biologically similar to native anatomy can be challenging because of the limited regeneration capacity of the tendon-bone interface. Orthopaedic basic-science research strategies aiming to augment tendon-to-bone healing include the use of osteoinductive growth factors, platelet-rich plasma, gene therapy, enveloping the grafts with periosteum, osteoconductive materials, cell-based therapies, biodegradable scaffolds, and biomimetic patches. Low-intensity pulsed ultrasound and extracorporeal shockwave treatment may affect tendon-to-bone healing by means of mechanical forces that stimulate biological cascades at the insertion site. Application of various loading methods and immobilization times influence the stress forces acting on the recently repaired tendon-to-bone attachment, which eventually may change the biological dynamics of the interface. Other approaches, such as the use of coated sutures and interference screws, aim to deliver biological factors while achieving mechanical stability by means of various fixators. Controlled Level-I human trials are required to confirm the promising results from in vitro or animal research studies elucidating the mechanisms underlying tendon-to-bone healing and to translate these results into clinical practice.

OBJECTIVE: To assess the ability of 3D MR shoulder reconstructions to accurately quantify glenoid bone loss in the clinical setting using findings at the time of arthroscopy as the gold standard. MATERIALS AND METHODS: Retrospective review of patients with MR shoulder studies that included 3D MR reconstructions (3D MR) produced using an axial Dixon 3D-T1W-FLASH sequence at our institution was conducted with the following inclusion criteria: history of anterior shoulder dislocation, arthroscopy (OR) performed within 6 months of the MRI, and an estimate of glenoid bone loss made in the OR using the bare-spot method. Two musculoskeletal radiologists produced estimates of bone loss along the glenoid width, measured in mm and %, on 3D MR using the best-fit circle method, which were then compared to the OR measurements. RESULTS: There were a total of 15 patients (13 men, two women; mean age, 28, range, 19-51 years). There was no significant difference, on average, between the MRI (mean 3.4 mm/12.6 %; range, 0-30 %) and OR (mean, 12.7 %; range, 0-30 %) measurements of glenoid bone loss (p = 0.767). A 95 % confidence interval for the mean absolute error extended from 0.45-2.21 %, implying that, when averaged over all patients, the true mean absolute error of the MRI measurements relative to the OR measurements is expected to be less than 2.21 %. Inter-reader agreement between the two readers had an IC of 0.92 and CC of 0.90 in terms of percentage of bone loss. CONCLUSIONS: 3D MR reconstructions of the shoulder can be used to accurately measure glenoid bone loss.

BACKGROUND: Anterior cruciate ligament reconstruction (ACLR) has traditionally been reserved for young patients with functional instability. As the aging population continues to grow and embrace a more active lifestyle, it is important to determine if favorable outcomes of ACLR can be achieved in older adults. METHODS: Patients greater than 50 years of age undergo- ing ACLR between January 2001 and September 2006 were identified. Charts were retrospectively reviewed for clinical, pathologic, and radiographic findings. Prospective data was collected at follow-up, including Lysholm Knee Score, Tegner Activity Level Score, International Knee Documenta- tion Committee (IKDC) Subjective Knee Form Score, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Anteroposterior (AP) instability was assessed with use of a KT-2000 arthrometer (MEDmetric, San Diego, CA). RESULTS: Forty-seven patients underwent ACLR with 32 (16 males and 16 females) available at a mean follow-up of 5.0 years (range: 2.2 to 9.0 years). The mean age at the time of operation was 58.4 years (range: 51 to 65 years). At time of final follow-up, the mean side-to-side difference measured by KT-2000 was 1.2 +/- 1.3 mm (range: 0 to 4.5 mm). Mean postoperative subjective IKDC score was 80.1 (range: 33 to 100) and Lysholm score was 86.7 (range: 45 to 95). There was no change in Tegner score from pre-injury (range: 0 to 3) to postoperative (range: 0 to 3). Twelve patients (38%) underwent subsequent knee surgery. All patients were sat- isfied with the final outcome of their ACLR surgery. Only patellofemoral Outerbridge cartilage grade was associated with worse outcome. CONCLUSION: ACLR provides symptomatic relief and restoration of function for patients greater than 50 years of age. ACLR should be considered in active older patients with subjective functional instability.

OBJECT: Our objective was to use 7 T MRI to compare cartilage morphology (thickness) and collagen composition (T2 values) in cartilage repair patients and healthy controls. MATERIALS AND METHODS: We scanned the knees of 11 cartilage repair patients and 11 controls on a 7 T MRI scanner using a high-resolution, gradient-echo sequence to measure cartilage thickness and a multi-echo spin-echo sequence to measure cartilage T2 values. We used two-tailed t tests to compare cartilage thickness and T2 values in: repair tissue (RT) versus adjacent cartilage (AC); RT versus healthy control cartilage (HC); AC versus HC. RESULTS: Mean thickness in RT, AC, HC were: 2.2 +/- 1.4, 3.6 +/- 1.1, 3.3 +/- 0.7 mm. Differences in thickness between RT-AC (p = 0.01) and RT-HC (p = 0.02) were significant, but not AC-HC (p = 0.45). Mean T2 values in RT, AC, HC were: 51.6 +/- 7.6, 40.0 +/- 4.7, 45.9 +/- 3.7 ms. Differences in T2 values between RT-AC (p = 0.0005), RT-HC (p = 0.04), and AC-HC (p = 0.004) were significant. CONCLUSION: 7 T MRI allows detection of differences in morphology and collagen architecture in: (1) cartilage repair tissue compared to adjacent cartilage and (2) cartilage repair tissue compared to cartilage from healthy controls. Although cartilage adjacent to repair tissue may be normal in thickness, it can demonstrate altered collagen composition.

Diabetes mellitus (DM) affects a significant proportion of the patients evaluated and treated by orthopedic surgeons who specialize in sports medicine. Sports-medicine-related conditions associated with DM include tendinopathy, adhesive capsulitis of the shoulder, and articular cartilage disease. This article reviews the current literature adressing the effect of DM on surgical outcomes in sports medicine. In general, patients with DM undergo operations more frequently and experience inferior surgical outcomes compared with patients without DM. Diabetes mellitus is associated with increased rates of complications from sports medicine procedures, such as infection, delayed healing, and failure of the operation. However, additional research is needed to determine the full impact of DM on patient outcomes in sports medicine. Surgeons should be cognizant of special considerations in the population of patients with DM and aim to tailor the surgical management of this growing patient population.

BACKGROUND: Chronic ruptures of the distal biceps are often complicated by tendon retraction and fibrosis, precluding primary repair. Reconstruction with allograft augmentation has been proposed as an alternative for cases not amenable to primary repair. PURPOSE: To investigate the clinical outcomes of late distal biceps reconstruction using allograft tissue. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 20 patients who underwent distal biceps reconstruction with allograft tissue between May 2007 and May 2012 were identified. Charts were retrospectively reviewed for postoperative complications, gross flexion and supination strength, and range of motion. Subjective functional outcomes were assessed prospectively with the Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. RESULTS: Eighteen patients with adequate follow-up were included in the study. All had undergone late distal biceps reconstruction with allografts (Achilles [n = 15], semitendinosus [n = 1], gracilis [n = 1], or anterior tibialis [n = 1]) for symptomatic chronic ruptures of the distal biceps. At a mean office follow-up of 9.3 months (range, 4-14 months), all patients had full range of motion and mean gross strength of 4.7 of 5 (range, 4-5) in flexion and supination. After a mean out-of-office follow-up at 21 months (range, 7-68.8 months), the mean DASH score was 7.5 +/- 17.9, and the mean MEPS increased from 43.1 preoperatively to 94.2 postoperatively (P < .001). The only complication observed was transient posterior interosseous nerve palsy in 2 patients. Additionally, all but 1 patient reported a cosmetic deformity. However, all patients found it acceptable. CONCLUSION: Late reconstruction for chronic ruptures of the distal biceps using allograft tissue is a safe and effective solution for symptomatic patients with functional demands in forearm supination and elbow flexion. While there are several graft options, the literature supports good results with Achilles tendon allografts. Further studies are needed to evaluate the clinical outcomes of other allograft options.