Arthroscopic Anterior Cruciate Ligament Femoral Tunnel Visualization for Button Fixation.

Arthroscopic reconstruction of the anterior cruciate ligament (ACL) remains one of the most commonly performed procedures in orthopaedic surgery. We describe a technique to visualize the button being advanced through the femoral tunnel using an arthroscope placed in the anteromedial portal. Looking into the femoral tunnel in line with the sutures, this technique allows the surgeon to directly visualize the femoral button as it traverses the femoral tunnel and confirms that it is engaged over the femoral cortex. Certain complications can arise, however, with the use of a suspensory fixation with a button on the femoral cortex. This method can decrease operative time and complication rates.

Immortalized Mouse Achilles Tenocytes Demonstrate Long-Term Proliferative Capacity While Retaining Tenogenic Properties.

Investigating the cellular processes underlying tendon healing can allow researchers to improve long-term outcomes after injury. However, conducting meaningful studies to uncover the injury healing mechanism at cellular and molecular levels remains challenging. This is due to the inherent difficulty in isolating, culturing, and expanding sufficient primary tenocytes, due to their limited proliferative capacity and short lifespan. In this study, we sought to establish a novel line of immortalized mouse Achilles tenocytes (iMATs) with primary tenocyte properties, but increased proliferative capacity suitable for extensive in vitro experimentation. We show that isolated primary mouse Achilles tenocytes (pMATs) can be effectively immortalized using a piggyBac transposon expressing SV40 large T antigen flanked by FLP recombination target site (FRT). The resulting iMATs exhibit markedly greater proliferation and survival, which can be reversed with FLP recombinase. Furthermore, iMATs express the same set of tendon-specific markers as that of primary cells, although in lower levels, and respond similarly to exogenous stimulation with bone morphogenetic protein 13 (BMP13) as has been previously reported with pMATs. Taken together, our results suggest that iMATs acquire long-term proliferative capacity while maintaining tenogenic properties. We believe that iMATs are a suitable model for studying not only the native cellular processes involved in injury and healing, but also potential therapeutic agents that may augment the stability of tendon repair.

Pectoralis major repair with cortical button technique.

Pectoralis major tendon ruptures can lead to significant functional deficits that affect high-level athletic and labor-intensive activities. In active populations operative repair of the ruptured pectoralis major tendon has shown significant advantages over nonoperative treatment. We describe a novel surgical technique for pectoralis major repair with tension button fixation. This study included 12 recreational athletes and 2 professional athletes. The initial results were measured subjectively after a minimum of 6 months by the Single Assessment Numeric Evaluation score, the American Shoulder and Elbow Surgeons score, and the ability to return to the patient's sport at a preinjury level. Objectively, strength was measured with resisted horizontal adduction of the arm for both repaired and contralateral sides. Of the 12 recreational patients, 8 returned to their sport at preinjury levels, and the 2 professional athletes returned to their sport at full capacity in the National Football League. The mean Single Assessment Numeric Evaluation score was 87, and the mean American Shoulder and Elbow Surgeons scores were 99 for both the operative and contralateral sides. Isokinetic strength testing showed no significant differences between the operative and nonoperative sides. Patients with pectoralis major tendons repaired with the proposed tensioned cortical button technique had excellent results. This new technique provides a reliable method of repair in an efficient and safe manner.

Posterior instability caused by batter's shoulder.

In summary, batter's shoulder is a rare and only recently recognized entity. This condition is posterior shoulder instability caused by a missed attempt at hitting a pitch, especially with an outside pitch. The lack of counterforce from hitting a ball produces increased forces imparted on the posterior capsulolabral complex of the lead shoulder during batting. If the player fails conservative management, she or he can undergo an arthroscopic posterior labral repair instead of debridement. After treatment, the player can expect to return to play after approximately 6 to 7 months. Initial results from a small, retrospective series demonstrate greater than 90% excellent results. These findings are similar to current literature for arthroscopic treatment of posterior instability, which reports success rates that range from 75% to 91%. Longer-term follow-up will be needed to determine the natural history and prognosis or batter's shoulder. Based on initial results, the authors predict good to excellent results for most players with batter's shoulder who undergo proper treatment. Additionally, with the exception of switch hitters, the nonthrowing arm is affected. This can also improve the athlete's return to play.

Age-related differences in radiographic parameters for femoroacetabular impingement in hip arthroplasty patients.

PURPOSE: To compare the prevalence of femoroacetabular impingement (FAI) radiographic findings between patients aged younger than 50 years and those aged 50 years or older who underwent total hip arthroplasty. METHODS: Total hip arthroplasty patients aged younger than 50 years and those aged 50 years or older were identified retrospectively from a facility medical record database. Fifty patients from each group were randomly selected, and preoperative radiographs were collected. Dysplastic, inflammatory, post-traumatic, and osteonecrosis patients were excluded. Radiographs were evaluated for FAI-specific findings. Intraobserver and interobserver reliability was evaluated with κ statistics for categorical variables and intraclass correlation coefficients for continuous variables. An independent t test was used to compare continuous variables, χ(2) analysis was used for discrete variables, and a z ratio was used to analyze proportions. RESULTS: The mean age between the subgroups of patients aged younger than 50 years and those aged 50 years or older (43 years and 68 years, respectively) was significantly different (P < .05). Findings in the subgroup aged younger than 50 years included significantly more men (P < .001), decreased lateral joint space with maintained medial joint space (P < .05), significantly greater alpha angle on both the anteroposterior view and the frog-leg lateral view (P < .05), significantly higher Tönnis and Sharp angles (P < .01), and significantly lower center-edge angle (P < .001). CONCLUSIONS: This retrospective case series shows an increased prevalence of FAI findings (specifically cam pathology) in a patient population aged younger than 50 years undergoing total hip arthroplasty when compared with a cohort aged 50 years or older. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

The biomechanical effects of 1.0 to 1.2 Mrad of γ irradiation on human bone-patellar tendon-bone allografts.

BACKGROUND: Recent data suggest that anterior cruciate ligament (ACL) reconstruction with irradiated allograft tissue may lead to increased failure rates. HYPOTHESIS: Low-dose (1.0-1.2 Mrad) gamma irradiation does not significantly alter the preimplantation biomechanical properties of bone-patellar tendon-bone (BTB) allografts. STUDY DESIGN: Controlled laboratory study. METHODS: Cyclic and failure mechanical properties were evaluated for 20 paired central-third human BTB allografts, with and without 1.0 to 1.2 Mrad of gamma irradiation. Testing included cyclic loading at 0.5 Hz for 100 cycles from 50 to 200 N and failure testing at a strain rate of 10% per second. RESULTS: Cyclic elongation did not change significantly (P = .151) with irradiation, increasing from a mean ± SD of 9.4 ± 2.1 mm to 11.3 ± 3.4 mm. Cyclic creep strain approached a significant increase with irradiation (1.3% ± 0.8% to 2.6% ± 1.5%; P = .076). Failure testing was not affected with irradiation with regard to maximum load (1680 ± 417 mm to 1494 ± 435 mm), maximum stress (40.8 ± 10.6 MPa to 37.5 ± 15.7 MPa), elongation (7.85 ± 1.35 mm to 8.67 ± 2.05 mm), or strain at maximum stress (0.158 ± 0.03 to 0.175 ± 0.03). Graft stiffness significantly decreased by 20% with irradiation (278 ± 67 N/mm to 221 ± 50 N/mm; P = .035). CONCLUSION: Low-dose (1.0-1.2 Mrad) gamma irradiation decreases BTB graft stiffness by 20%, but it does not affect other failure or cyclic parameters. CLINICAL RELEVANCE: Aside from graft stiffness during load to failure testing, low-dose (1.0-1.2 Mrad) gamma irradiation of central-third human BTB allografts is not deleterious to preimplantation biomechanical properties.

Emerging ideas: Novel 3-D quantification and classification of cam lesions in patients with femoroacetabular impingement.

BACKGROUND: Femoroacetabular impingement (FAI) can lead to labral injury, osseous changes, and even osteoarthritis. The literature contains inconsistent definitions of the alpha angle and other nonthree-dimensional (3-D) radiographic measures. We present a novel approach to quantifying cam lesions in 3-D terms. Our method also can be used to develop a classification system that describes the exact location and size of cam lesions. QUESTIONS/HYPOTHESES: We asked whether automated quantification of CAM lesions based on CT data is a reasonable way to detect CAM lesions and whether they may be classified based on location. METHOD OF STUDY: We developed a method to quantify femoral head cam lesions using 3-D modeling of CT scans. By segmenting raw DICOM data, we can determine the distance from the cam lesion's surface points to the centroid of the femoral head to quantify the mean bump height, volume, and location. The resulting 3-D femoral and acetabular models will be analyzed with custom software. We then will quantify the cam lesion with 3-D parameters using a modified zoning method. The mean bump height, volume, and location on the clock face, and relative zoning will be calculated. Zonal differences will be statistically analyzed. To assess the ability of this method to predict arthroscopic findings, we will obtain preoperative CT scans for 25 patients who undergo hip arthroscopy for FAI. We will compare measurements with the method with our measurements from arthroscopy. The clinical implications of our method's measurements then will be reviewed and refined for future prospective studies. SIGNIFICANCE: We present a novel approach that can quantify a cam lesion's location and size. This method will be used to provide guidelines for the exact amount of bony resection needed from a specific location of the proximal femur. There is also potential to develop software for ease of use so this method can be more widely applied.

Allograft meniscus transplantation.

Menisci function to manage load transmission, provide secondary mechanical stability as well as nutrition, and lubricate the joint. Meniscus transplantation techniques continue to evolve and include: free soft tissue allograft implantation; separate anterior and posterior bone plugs; and bone bridges including key hole, trough, dovetail, and bridge-in-slot variations. The senior author's preference is for the bridge-in-slot technique for lateral and medial menisci, owing to its simplicity and secure bony fixation, flexibility in allowing concomitant procedures as osteotomy and ligament reconstruction, and the ability to maintain the native anterior and posterior meniscal horn attachments. Meniscal allograft transplantation yields fair to excellent results in almost 85% of patients. Patients demonstrate significant decrease in pain, as well as an increase in activity. Long-term success is encouraging in well-selected patients but is unknown whether transplantation is protective against the progression of degenerative changes.

Effect of donor age on bone mineral density in irradiated bone-patellar tendon-bone allografts of the anterior cruciate ligament.

BACKGROUND: Allograft tissue remains a valuable alternative for anterior cruciate ligament reconstruction. No study to date has correlated the effect of donor age to bone mineral density (BMD) in a large series of irradiated bone-patellar tendon-bone (BPTB) allograft tissue. Hypothesis/ PURPOSE: The authors attempted to correlate donor age with BMD in a large group of BPTB allograft specimens treated with low-dose gamma irradiation (1.0-1.3 Mrad) collected over a 4-year period. They hypothesized there would be no effect of donor age on the BMD of irradiated BPTB allografts. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 110 BPTB allograft specimens from 44 male and 66 female donors with a mean age of 46 years (range, 21-58 years) were analyzed. Bone mineral density data were obtained from both the patellar and tibial bone plugs of the BPTB complex. Statistical analyses were conducted using linear regression for correlations and 2-tailed Student t tests for comparisons between groups. RESULTS: The mean BMD of the patellar bone plug (0.471 g/cm(2)) was significantly greater than the mean BMD of the tibial bone plug (0.328 g/cm(2)) (P < .001). No correlation was identified between donor age and BMD for either the patella or tibial bone plugs (R(2) = .014 and .011, respectively). Both patellar and tibial BMD was significantly greater for the male grafts than the female ones. CONCLUSION: No correlation was found between donor age and BMD for irradiated BPTB allograft tissue. The patellar bone plugs were noted to have a greater BMD than the tibial bone plugs. Allograft tissue from male donors had higher BMD values than that harvested from female donors.

Osteochondral Tissue Cell Viability Is Affected by Total Impulse during Impaction Grafting.

OBJECTIVE: Osteochondral graft transplantation has garnered significant attention because of its ability to replace the lesion with true hyaline cartilage. However, surgical impaction of the graft to anchor it into the defect site can be traumatic and lead to cell death and cartilage degeneration. This study aimed to test the hypothesis that increasing impulse magnitude during impaction of osteochondral plugs has a direct effect on loss of cell viability. DESIGN: In this controlled laboratory study, the impaction force was kept constant while the impulse was varied. Ninety-six osteochondral plugs were extracted from the trochlea of bovine stifle joints and were randomly assigned into 3 experimental and 1 (nonimpacted) control group. The transferred impulse of the experimental groups reflected the median and the lower and upper quartiles of preceding clinical measurements. Data were obtained at day 0, day 4, and day 8; at each point, cell viability was assessed using the Live/Dead staining kit and histological assessments were performed to visualize matrix structural changes. RESULTS: After impaction, cartilage samples stayed intact and did not show any histological signs of matrix disruption. As expected, higher impulse magnitudes introduced more cell death; however, this relationship was lost at day 8 after impaction. CONCLUSION: Impulse magnitude has a direct effect on cell viability of the graft. Because impulse magnitude is mostly governed by the press-fit characteristics of the recipient site, this study aids in the definition of optimal insertion conditions for osteochondral grafts.

Effect of impaction sequence on osteochondral graft damage: the role of repeated and varying loads.

BACKGROUND: Osteochondral autografts and allografts require mechanical force for proper graft placement into the defect site; however, impaction compromises the tissue. This study aimed to determine the effect of impaction force and number of hits to seat the graft on cartilage integrity. HYPOTHESIS: Under constant impulse conditions, higher impaction load magnitudes are more detrimental to cell viability, matrix integrity, and collagen network organization and will result in proteoglycan loss and nitric oxide release. STUDY DESIGN: Controlled laboratory study. METHODS: Osteochondral explants, harvested from fresh bovine trochleae, were exposed to a series of consistent impact loads delivered by a pneumatically driven device. Each plug received the same overall impulse of 7 Ns, reflecting the mean of 23 clinically inserted plugs. Impaction loads of 37.5 N, 75 N, 150 N, and 300 N were matched with 74, 37, 21, and 11 hits, respectively. After impaction, the plugs were harvested, and cartilage was analyzed for cell viability, histology by safranin-O and picrosirius red staining, and release of sulfated glycosaminoglycans (GAGs) and nitric oxide. Data were compared with nonimpacted controls. RESULTS: Impacted plugs had significantly lower cell viability than nonimpacted plugs. A dose-response relationship in loss of cell viability with respect to load magnitude was seen immediately and after 4 days but lost after 8 days. Histological analysis revealed intact cartilage surface in all samples (loaded or control), with loaded samples showing alterations in birefringence. While the sulfated GAG release was similar across varying impaction loads, release of nitric oxide increased with increasing impaction magnitudes and time. CONCLUSION: Impaction loading parameters have a direct effect on the time course of the viability of the cartilage in the graft tissue. CLINICAL RELEVANCE: Optimal loading parameters for surgical impaction of osteochondral grafts are those with lower load magnitudes and a greater number of hits to ensure proper fit.

Complications associated with anterior shoulder instability repair.

Anterior shoulder instability is a common orthopaedic problem, and the surgical treatment, both open and arthroscopic, has been shown to effectively restore stability and prevent recurrence. However, despite success with these surgical techniques, there are several clinically relevant complications associated with both open and arthroscopic techniques for anterior shoulder stabilization. These complications can be subdivided into preoperative, intraoperative, and postoperative and include entities such as nerve injury, chondrolysis, incomplete treatment of associated lesions, and subscapularis dysfunction. When they occur, complications may significantly impact patient outcomes and function. Therefore, surgeon awareness and identification of the factors associated with these complications may help prevent occurrence. Although failure of instability repair can be classified as a complication of surgery, it requires an entirely separate discussion and is therefore not addressed in this article. Because most of the previously published studies on anterior shoulder instability have emphasized surgical technique and clinical outcomes, the purpose of this article is to define the complications associated with anterior instability repair and provide recommendations on techniques that may be used to help avoid them.

Triad of cartilage restoration for unicompartmental arthritis treatment in young patients: meniscus allograft transplantation, cartilage repair and osteotomy.

Arthritis treatment in young patients remains a challenge. Joint replacement surgery offers excellent pain relief but is controversial with this age group because of long-term wear and loosening. Recently, biological reconstructive techniques have become available to improve traditional treatment methods such as osteotomies. We present our experience with a technique for combined meniscal transplantation, chondral repair, and osteotomy in 7 patients presenting with a constellation of meniscal deficiency, focal arthritis, and malalignment. Patients underwent concurrent or staged meniscal transplantation, cartilage repair, and osteotomy. Evaluation included the International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Short Form-12 and Lysholm scales. At average follow-up of 24 months, patients experienced significant improvements in the IKDC, Lysholm, and KOOS functional scores. Six of 7 patients were able to return to unrestricted activities; 1 patient experienced mild pain with high-impact activities. Combined treatment with meniscal transplantation, cartilage repair, and osteotomy demonstrated promising clinical results of unicompartmental arthritis treatment in young patients.

A randomized, prospective, double-blind study to investigate the effectiveness of adding DepoMedrol to a local anesthetic injection in postmeniscectomy patients with osteoarthritis of the knee.

BACKGROUND: Patients with osteoarthritis of the knee are at risk for poorer outcomes after arthroscopic meniscectomy. Intra-articular corticosteroid injections have been shown to be efficacious both in patients with osteoarthritis and postarthroscopy patients. HYPOTHESIS: A postoperative, intra-articular methylprednisolone and lidocaine injection in patients with chondromalacia undergoing meniscectomy will improve patient-rated pain and function compared with control patients. STUDY DESIGN: Randomized, controlled trial; Level of evidence, 1. METHODS: A total of 58 patients (59 knees) were randomized in a double-blinded fashion to receive either saline plus lidocaine (saline) or methylprednisolone plus lidocaine (steroid) after arthroscopic meniscectomy in which chondromalacia (modified Outerbridge grade 2 or higher) was confirmed. Preoperatively and at follow-up-6 weeks and 6, 9, and 12 months-patients underwent an examination and completed a subjective functioning survey. Scores were calculated using several validated scoring systems including the Lysholm, International Knee Documentation Committee (IKDC), and Short Form-12 (SF-12). RESULTS: No statistically significant differences were observed between the saline (n = 30) and steroid (n = 29) groups in their demographics and preoperative scores. At 6 weeks, the steroid group had higher scores than the saline group on multiple scales, including the IKDC. No differences in outcome scores existed at later time points. At 12 months, 86% of the steroid and 69% of the saline group were completely or mostly satisfied with the procedure (P = .01). In the saline group, 4 patients required reinjection and 2 underwent joint replacements within 12 months, while the steroid group had 3 reinjections and 2 meniscus transplants. CONCLUSION: The addition of a postoperative corticosteroid injection resulted in improved pain and function at an early time point; however, it provided no lasting difference compared with only local anesthetic injection.

Long-term effects of bupivacaine on cartilage in a rabbit shoulder model.

BACKGROUND: Previous investigations have reported on the chondrotoxicity of bupivacaine in short-term in vivo and in vitro models. This study was designed to provide additional information on the long-term effects of bupivacaine infusion on articular cartilage in an established rabbit shoulder model. HYPOTHESIS: Infusion of bupivacaine into the rabbit shoulder will have long-term deleterious effects on articular cartilage. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-six rabbits were randomized into 3 groups and were infused over 48 hours with saline (S), bupivacaine alone (B), or bupivacaine with epinephrine (B+E) into the glenohumeral joint. Animals were sacrificed after 3 months, and tissue samples were analyzed with live/dead cell assay, proteoglycan (PG) synthesis and content assays, and conventional histological evaluation. RESULTS: No macroscopic or radiographic changes were detected in the infused shoulders. Sulfate uptake of infused shoulders relative to controls was elevated to 112% +/-39% (S), 166% +/-67% (B), and 210% +/-127% (B+E). Statistical analysis of PG content demonstrated significantly increased levels in bupivacaine groups compared with saline. There were no significant differences among groups in cell count, percentage of living cells, or histological grade. CONCLUSIONS: No permanent impairment of cartilage function was detected 3 months after intra-articular infusion of bupivacaine. Cartilage metabolism was increased, indicating a possible reparative response. This suggests that, at least in the model used, articular cartilage has the ability to recover from the chondrotoxic effects of bupivacaine infusion. Before extrapolating these results to human cartilage, other factors including underlying cartilage injury or disease, decreased chondrocyte density, and increased bupivacaine dosing need to be taken into account. Clinical Relevance Bupivacaine toxicity has recently been implicated in the development of chondrolysis after arthroscopic shoulder procedures, but these findings suggest that additional noxious stimuli might be required before permanent damage ensues.

Biceps tendinitis in chronic rotator cuff tears: a histologic perspective.

Patients with chronic rotator cuff tears frequently have anterior shoulder pain attributed to the long head of the biceps brachii (LHBB) tendon. In this study, tenodesis or tenotomy samples and cadaveric controls were assessed by use of immunohistochemical and histologic methods to quantify inflammation, vascularity, and neuronal plasticity. Patients had moderate pain and positive results on at least 1 clinical test of shoulder function. The number of axons in the distal LHBB was significantly less in patients with biceps tendinitis. Calcitonin gene-related peptide and substance P immunostaining was predominantly within nerve roots and blood vessels. A moderate correlation (R = 0.5) was identified between LHBB vascularity and pain scores. On the basis of these results, we conclude that, in the context of rotator cuff disease, the etiology of anterior shoulder pain with macroscopic changes in the biceps tendon is related to the complex interaction of the tendon and surrounding soft tissues, rather than a single entity.