Stephen H. Liu

Arthroscopically assisted rotator cuff repair: Correlation of functional results with integrity of the cuff

Thirty-three patients (35 full-thickness rotator cuff tears) who underwent arthroscopically assisted mini open repair between June 1987 and January 1990 were evaluated for shoulder function and cuff integrity. The study population was composed of 19 women and 14 men with an average age of 63 years (range 35-76) and an average follow-up of 3.7 years (range 2.5-5.1). Functional results were obtained using the UCLA Shoulder Rating Scale. Integrity of the rotator cuff was established by shoulder arthrography at a minimum 2 years postoperatively. UCLA Shoulder Rating Scale showed 86% good/excellent results with 92% patient satisfaction. The shoulder arthrography showed 12 (34%) full-thickness tears, seven (20%) partial tears, and 16 (46%) no tears. The size of the arthrographic defect correlated well with the size of the intraoperative tear. Seventy percent of the large tears had follow-up full-thickness defects and 80% of the small tears had no defect. Eighty percent and 88% good/excellent functional results were achieved in patients with full-thickness defects and no defects, respectively, without significant differences. The size of the tear at the time of the repair is a major determinant of the integrity of the cuff after repair. The integrity of the cuff at follow-up does not determine the functional outcome of the operated shoulder.

Estrogen Affects the Cellular Metabolism of the Anterior Cruciate Ligament A Potential Explanation for Female Athletic Injury

Investigations from this laboratory have established the presence of estrogen receptors in the human an terior cruciate ligament. This study further investigates the effects of 17β-estradiol on the cellular proliferation and collagen synthesis of fibroblasts derived from the rabbit anterior cruciate ligament. Fibroblast prolifera tion and collagen synthesis in response to near log concentrations of 17β-estradiol (at 0.0029, 0.025, 0.25, 2.5, and 25 ng/ml) were assessed by measuring [3H]thymidine and [14 C]hydroxyproline incorporation, respectively. Collagen synthesis was significantly re duced with increasing local estradiol concentration (P < 0.001). Declining collagen synthesis was first noted at a 17β-estradiol concentration of 0.025 ng/ml. Within normal physiologic levels of estrogen (0.025 to 0.25 ng/ml), collagen synthesis was reduced by more than 40% of control, and at pharmacologic levels of 2.5 and 25 ng/ml, by more than 50% of control. A signifi cant reduction of fibroblast proliferation was also ob served with increasing estradiol concentrations (P = 0.023). Clinically, alterations in anterior cruciate liga ment cellular metabolism caused by estrogen fluctua tions may change the composition of the ligament, rendering it more susceptible to injury.

Morphology and matrix composition during early tendon to bone healing.

This study outlines the early morphologic phenomenon of tendon to bone healing in the rabbit model. Twelve skeletally mature, male New Zealand White rabbits received transplantation of the hallucis longus tendon into a 2-mm calcaneal bone tunnel. The morphologic characteristics of the healing tendon to bone interface were evaluated at 1, 2, 4, and 6 weeks after surgery by the use of conventional histology and immunohistochemical localization of collagen Types I, II, and III. Histologic analysis illustrated progressive maturation and reorganization of the tendon to bone interface with subsequent development of tissue collagen fiber continuity between the tendon and bone. Initially, diffuse immunolocalization of all three collagen types was observed within the scar tissue filling the space between the tendon and bone. During a 6-week period, reorganization of the scar tissue into an interface occurred, similar to an indirect insertion. Although a definitive fibrocartilage region did not form, Type II collagen was localized at the remodeling insertion site throughout the first 6 weeks of repair. In addition, Type III collagen fibers, resembling Sharpeys fibers, were noted to span this interface. The characterization of the insertion between tendon and bone is important to the understanding of healing in commonly used orthopaedic grafting procedures, such as anterior cruciate ligament reconstructions.

Long-term effects of fetal ethanol exposure on pituitary-adrenal response to stress ☆

Pregnant female rats were fed either a 5.0-5.5% w/v ethanol-containing liquid diet ad lib or pair-fed the isocaloric control diet during gestation weeks 2 and 3. At 75-105 days of age, female offspring of the ethanol-treated dams showed significantly greater corticosterone responses than pair-fed- or normally-derived offspring to the stress of cardiac puncture or of noise and shaking, while pituitary-adrenal responses to exposure to a novel environment, cold or 2-3 days of fasting were normal. Adrenal sensitivity to ACTH in dexamethasone-suppressed adult offspring was unaffected by the prenatal treatment. The results demonstrate that fetal ethanol exposure enhances adult pituitary-adrenal responses to certain stressors, including alcohol as demonstrated previously, and suggest that the long-term effects may be mediated by developmental actions of alcohol on central neural mechanisms involved in the regulation of this neuroendocrine system.

Comparison of Open and Arthroscopically Assisted Rotator Cuff Repairs

Open rotator cuff repair has shown reliable results in terms of pain relief and improved shoulder function. Re cently, however, arthroscopically assisted rotator cuff repair has shown promising preliminary results. We compared the results of these two procedures with re gard to pain, function, range of motion, strength, patient satisfaction, and return to previous activity. Thirty-seven rotator cuff repairs were evaluated in 36 patients with a minimum followup of 2 years. The open repair group comprised 20 shoulders with an average followup of 3.3 years; the arthroscopically assisted repair group com prised 17 shoulders with an average followup of 3.2 years. Overall, the open repair group had 80% good- to-excellent results and 88% patient satisfaction, and the arthroscopically assisted repair group had 85% good-to-excellent results and 92% patient satisfaction. Shoulder flexion and abduction strength, the size of the tear repaired, and the functional outcome did not differ significantly between the two groups. In general, how ever, small and moderate-sized tears (<3 cm) had bet ter functional outcome with arthroscopically assisted re pair. The arthroscopically assisted repair group was hospitalized 1.2 days less and returned to previous ac tivity an average of 1 month earlier. In the surgical treat ment of symptomatic complete rotator cuff tears, arthro scopically assisted rotator cuff repair is as effective as open repair.

Combined effects of estrogen and progesterone on the anterior cruciate ligament.

Previous studies from the authors’ laboratory have established the presence of estrogen and progesterone receptors in the human anterior cruciate ligament. The purpose of the current study was to investigate the combined effects of 1˘β-estradiol and progesterone on cell proliferation and procollagen synthesis of the human anterior cruciate ligament fibroblasts. Fibroblast proliferation and procollagen synthesis in response to logarithmic concentrations of 17β-estradiol (0.0025 ng/mL, 0.025 ng/mL, 0.25 ng/mL) and progesterone (1 ng/mL, 10 ng/mL, 100 ng/mL) were assessed with the measurement of 3H-thymidine incorporation and Types I and III procollagen specific equilibrium radioimmunoassays. On Days 1, 3, and 5 there was a dose dependent decrease in the fibroblast proliferation and procollagen Type I synthesis with increasing estradiol concentrations. The effect was attenuated with increasing progesterone concentrations. Controlling for estrogen levels, a dose dependent increase in fibroblast proliferation and procollagen Type I synthesis was observed with increasing progesterone concentrations. The effect was more pronounced at lower concentrations of estrogen, suggesting estrogen levels were the dominant factor. The effects of estrogen and progesterone became less apparent by Day 7. No significant differences in Type III procollagen synthesis were seen with varying estradiol concentrations at any of the designated times. These early physiologic changes in fibroblast proliferation and Type I procollagen synthesis may provide a biologic explanation for the increased anterior cruciate ligament injury rate observed in female athletes, suggesting the acute cyclical hormonal variations in the female athlete during menstruation predispose her to ligamentous injury.

Effect of estrogen on cellular metabolism of the human anterior cruciate ligament

Previous studies from this laboratory have established the presence of estrogen receptors in the human anterior cruciate ligament. The purpose of this study was to investigate the effects of 17 beta-estradiol on cell proliferation and procollagen levels, as an indicator of collagen synthesis, in the human anterior cruciate ligament fibroblasts. Fibroblast proliferation and procollagen synthesis in response to near log concentrations of 17 beta-estradiol (at 0.0029 ng/mL, 0.025 ng/mL, 0.25 ng/mL, 2.5 ng/mL, and 25 ng/mL) were assessed with the measurement of 3H-thymidine incorporation and Types 1 and 3 procollagen specific equilibrium radioimmunoassays. On Days 1 and 3, there was a dose dependent decrease in the proliferation of anterior cruciate ligament fibroblasts with increasing estradiol concentrations. This dose dependent effect of decreased fibroblast proliferation with increasing estradiol concentrations became less apparent at 7, 10, and 14 days. On Days 1 and 3, procollagen synthesis decreased in a dose dependent manner with increasing estradiol concentrations. On Days 7, 10, and 14, this dose dependent effect was attenuated. No significant differences in Type 3 procollagen synthesis by anterior cruciate ligament fibroblasts were observed with varying estradiol concentrations at any of the designated points. These early physiologic changes in fibroblast proliferation and Type I procollagen synthesis may provide a biologic explanation for the increased anterior cruciate ligament injury rate observed in female athletes, suggesting that it is the acute cyclic variations in the female athlete who is menstruating that predisposes her to ligamentous injury.

Diagnosis of Anterolateral Ankle Impingement Comparison Between Magnetic Resonance Imaging and Clinical Examination

We reviewed 22 patients who had arthroscopic evalu ations and preoperative magnetic resonance imaging studies of their ankles because of chronic anterolateral ankle pain after sprains. The ability of surgeons to use the initial clinical examination to predict arthroscopi cally confirmed anterolateral ankle impingement was compared with the ability to predict this condition using preoperative magnetic resonance imaging. The patient population consisted of 15 men and 7 women who had an average age of 28 years. Five patients (23%) were intercollegiate athletes and 17 patients (77%) were recreational athletes. All patients reported previous traumas to the involved ankles, and all were seen with chronic ankle pain. Clinical examinations were used to assess ankle pain, swelling, range of motion, and sta bility. Anterolateral ankle impingement was confirmed in 18 patients (82%) with arthroscopic examination. Clinical examinations had a sensitivity of 94% and a specificity of 75% for predicting impingement, and magnetic resonance imaging had a sensitivity of 39% and a specificity of 50%. The results of this study suggest that preoperative magnetic resonance imag ing examination is not beneficial or cost-effective in the diagnosis of anterolateral ankle impingement; further more, its use may cause further delay in treatment.

Arthroscopic treatment of anterolateral ankle impingement

Fifty-five ankle arthroscopies performed for anterolateral ankle impingement between January 1987 and April 1992 were reviewed for functional outcome and patient satisfaction. There were 33 men and 22 women with an average age of 34 years (range 20-67). All patients reported a previous history of ankle injury, and 60% of the patients had at least one ankle sprain. At an average follow up of 2.6 years (range 1.0-4.5), 87% of the patients had good/excellent results, 98% were satisfied, and 84% returned to their previous sports.

Diagnosis of Glenoid Labral Tears: A Comparison Between Magnetic Resonance Imaging and Clinical Examinations

We studied 54 patients with shoulder pain secondary to anterior instability or glenoid labral tears refractory to 6 months of conservative management with no evi dence of rotator cuff lesions. All patients had sufficient preoperative clinical data, magnetic resonance imag ing, and shoulder arthroscopy results for analysis. The ability to predict the presence of a glenoid labral tear by physical examination was compared with that of mag netic resonance imaging (conventional and arthro gram) and confirmed with arthroscopy. There were 37 men and 17 women (average age, 34 years) in the study group. Of this group, 64% were throwing athletes and 61% recalled specific traumatic events. Clinical assessment included history with specific attention to pain with overhead activities, clicking, and instances of shoulder instability. Physical examination included the apprehension, relocation, load and shift, inferior sulcus sign, and crank tests. Shoulder arthroscopy confirmed labral tears in 41 patients (76%). Magnetic resonance imaging produced a sensitivity of 59% and a specificity of 85%. Physical examination yielded a sensitivity of 90% and a specificity of 85%. Physical examination is more accurate in predicting glenoid labral tears than magnetic resonance imaging. In this era of cost con tainment, completing the diagnostic workup in the clinic without expensive ancillary studies allows the patients care to proceed in the most timely and economic fashion.