John C. Richmond

Development and Validation of the International Knee Documentation Committee Subjective Knee Form

A committee of international knee experts created the International Knee Documentation Committee Subjective Knee Form, which is a knee-specific, rather than a disease-specific, measure of symptoms, function, and sports activity. The purpose of this study was to evaluate the reliability and validity of the new International Knee Documentation Committee Subjective Knee Form. To provide evidence for reliability and validity, we administered the final version of the form, along with the Short Form-36, to 533 patients with a variety of knee problems. Analyses were performed to determine reliability, validity, and differential item function related to age, sex, and diagnosis. Factor analysis revealed a single dominant component, making it reasonable to combine all questions into a single score. Internal consistency and test-retest reliability were 0.92 and 0.95, respectively. Based on test-retest reliability, the value for a true change in the score was 9.0 points. The International Knee Documentation Committee Subjective Knee Form score was related to concurrent measures of physical function (r = 0.47 to 0.66) but not to emotional function (r = 0.16 to 0.26). Analysis of differential item function indicated that the questions functioned similarly for men versus women, young versus old, and for those with different diagnoses. In conclusion, the International Knee Documentation Committee Subjective Knee Form is a reliable and valid knee-specific measure of symptoms, function, and sports activity that is appropriate for patients with a wide variety of knee problems. Use of this instrument will permit comparisons of outcome across groups with different knee problems.

Silk matrix for tissue engineered anterior cruciate ligaments

A silk-fiber matrix was studied as a suitable material for tissue engineering anterior cruciate ligaments (ACL). The matrix was successfully designed to match the complex and demanding mechanical requirements of a native human ACL, including adequate fatigue performance. This protein matrix supported the attachment, expansion and differentiation of adult human progenitor bone marrow stromal cells based on scanning electron microscopy, DNA quantitation and the expression of collagen types I and III and tenascin-C markers. The results support the conclusion that properly prepared silkworm fiber matrices, aside from providing unique benefits in terms of mechanical properties as well as biocompatibility and slow degradability, can provide suitable biomaterial matrices for the support of adult stem cell differentiation toward ligament lineages. These results point toward this matrix as a new option for ACL repair to overcome current limitations with synthetic and other degradable materials.

Cell differentiation by mechanical stress

Growth factors, hormones, and other regulatory molecules are traditionally required in tissue engineering studies to direct the differentiation of progenitor cells along specific lineages. We demonstrate that mechanical stimulation in vitro, without ligament‐selective exogenous growth and differentiation factors, induces the differentiation of mesenchymal progenitor cells from the bone marrow into a ligament cell lineage in preference to alternative paths (i.e., bone or cartilage cell lineages). A bioreactor was designed to permit the controlled application of ligament‐like multidimensional mechanical strains (translational and rotational strain) to the undifferentiated cells embedded in a collagen gel. The application of mechanical stress over a period of 21 days up‐regulated ligament fibroblast markers, including collagen types I and III and tenascin‐C, fostered statistically significant cell alignment and density and resulted in the formation of oriented collagen fibers, all features characteristic of ligament cells. At the same time, no up‐regulation of bone or cartilage‐specific cell markers was observed.

Responsiveness of the International Knee Documentation Committee Subjective Knee Form

Background and Purpose The International Knee Documentation Committee Subjective Knee Form was developed to measure change in symptoms, function, and sports activity in patients treated for a variety of knee conditions. Although previous research has demonstrated reliability and validity of the form, its responsiveness has not been evaluated. The purpose of this study was to determine responsiveness of the International Knee Documentation Committee Subjective Knee Form. Study Design Cohort study (diagnosis); Level of evidence, 1. Methods Patients who participated in the original validation study for the International Knee Documentation Committee Subjective Knee Form completed the form and a 7-level global rating of change scale that ranged from greatly worse to greatly better after a mean of 1.6 years (range, 0.5-2.3 years). Analyses included calculation of the standardized response mean and mean change in International Knee Documentation Committee Subjective Knee Form score compared to the patients perception of change on the global rating of change scale. In addition, a receiver operating characteristic curve was plotted to determine the change in score that best distinguished patients who improved from those who did not. Results The overall standardized response mean was 0.94, which is considered large. With the exception of those who were slightly worse or unchanged, the mean change in the International Knee Documentation Committee Subjective Knee Form score compared to the patients’ perceived global ratings of change was as expected (greatly worse,–15.1; somewhat worse,–8.4; slightly worse, 20.6; no change, 10.7; slightly better, 5.9; somewhat better, 18.1; greatly better, 38.7). The receiver operating characteristic curve analysis revealed that a change score of 11.5 points had the highest sensitivity, and a change score of 20.5 points had the highest specificity to distinguish between those who were or were not improved. Conclusion The International Knee Documentation Committee Subjective Knee Form is a responsive measure of symptoms, function, and sports activity for patients with a variety of knee conditions.

Meniscal Allograft Transplantation Two- to Eight-Year Results

We evaluated 18 of 23 patients who had undergone cryopreserved meniscal allograft transplantation for compartmental pain after total meniscectomy 2 to 8 years (mean, 5.4) after the operation. The Short Form-36 scores revealed a decrease in pain with a significant improvement in function, although function remained limited. There was no significant decrease in joint space on 45° posteroanterior weightbearing radiographs through the duration of the study. Eight of 22 allograft menisci (36%) tore during the study period, necessitating 6 partial and 2 total meniscectomies. Two patients subsequently underwent reimplantation. Histologic examination of the removed tissue revealed reduced cellularity as compared with normal or torn native menisci. Four specimens also underwent detailed cytokine evaluation and demonstrated reduced cytokine expression compared with controls. While successful in alleviating compartmental pain that may be a late consequence of major meniscectomy, allograft menisci are repopulated with fewer cells than are present in normal or torn native menisci. These cells also demonstrate potentially reduced function, as measured by decreased growth factor production. This decreased biologic activity may be a factor that contributes to the high frequency of retears noted in this and prior studies.

Advanced Bioreactor with Controlled Application of Multi-Dimensional Strain For Tissue Engineering

Advanced bioreactors are essential for meeting the complex requirements of in vitro engineering functional skeletal tissues. To address this need, we have developed a computer controlled bench-top bioreactor system with capability to apply complex concurrent mechanical strains to three-dimensional matrices independently housed in 24 reactor vessels, in conjunction with enhanced environmental and fluidic control. We demonstrate the potential of this new system to address needs in tissue engineering, specifically toward the development of a tissue engineered anterior cruciate ligament from human bone-marrow stromal cells (hBMSC), where complex mechanical and biochemical environment control is essential to tissue function. Well-controlled mechanical strains (resolution of < 0.1 micron for translational and < 0.1 degree for rotational strain) and dissolved oxygen tension (between 0%-95% +/- 1%) could be applied to the developing tissue, while maintaining temperature at 37 +/- 0.2 degrees C about developing tissue over prolonged periods of operation. A total of 48 reactor vessels containing cell culture medium and silk fiber matrices were run for up to 21 days under 90 degrees rotational and 2 mm translational deformations at 0.0167 Hz with only one succumbing to contamination due to a leak at an medium outlet port. Twenty-four silk fiber matrices seeded with human bone marrow stromal cells (hBMSCs) housed within reactor vessels were maintained at constant temperature (37 +/- 0.2 degrees C), pH (7.4 +/- 0.02), and pO2 (20 +/- 0.5%) over 14 days in culture. The system supported cell spreading and growth on the silk fiber matrices based on SEM characterization, as well as the differentiation of the cells into ligament-like cells and tissue (Altman et al., 2001).

Institutional Prescreening for Detection and Eradication of Methicillin-Resistant Staphylococcus aureus in Patients Undergoing Elective Orthopaedic Surgery

BACKGROUND Surgical site infection has been identified as one of the most important preventable sources of morbidity and mortality associated with medical treatment. The purpose of the present study was to evaluate the feasibility and efficacy of an institutional prescreening program for the preoperative detection and eradication of both methicillin-resistant and methicillin-sensitive Staphylococcus aureus in patients undergoing elective orthopaedic surgery. METHODS Data were collected prospectively during a single-center study. A universal prescreening program, employing rapid polymerase chain reaction analysis of nasal swabs followed by an eradication protocol of intranasal mupirocin and chlorhexidine showers for identified carriers, was implemented. Surgical site infection rates were calculated and compared with a historical control period immediately preceding the start of the screening program. RESULTS During the study period, 7019 of 7338 patients underwent preoperative screening before elective surgery, for a successful screening rate of 95.7%. One thousand five hundred and eighty-eight (22.6%) of the patients were identified as Staphylococcus aureus carriers, and 309 (4.4%) were identified as methicillin-resistant Staphylococcus aureus carriers. A significantly higher rate of surgical site infection was observed among methicillin-resistant Staphylococcus aureus carriers (0.97%; three of 309) compared with noncarriers (0.14%; seven of 5122) (p = 0.0162). Although a higher rate of surgical site infection was also observed among methicillin-sensitive Staphylococcus aureus carriers (0.19%; three of 1588) compared with noncarriers, this difference did not achieve significance (p = 0.709). Overall, thirteen cases of surgical site infection were identified during the study period, for an institutional infection rate of 0.19%. This rate was significantly lower than that observed during the control period (0.45%; twenty-four cases of surgical site infection among 5293 patients) (p = 0.0093). CONCLUSIONS Implementation of an institution-wide prescreening program for the identification and eradication of methicillin-resistant and methicillin-sensitive Staphylococcus aureus carrier status among patients undergoing elective orthopaedic surgery is feasible and can lead to significant reductions in postoperative rates of surgical site infection. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

American Academy of Orthopaedic Surgeons Lower Limb Outcomes Assessment Instruments: Reliability, Validity, and Sensitivity to Change

BACKGROUND The American Academy of Orthopaedic Surgeons (AAOS) has developed an array of outcomes assessment instruments designed for the efficient collection of outcomes data from patients of all ages with musculoskeletal conditions in all body regions. The Lower Limb Instruments were developed through a process of literature review, consensus-building, and field-testing. METHODS The instruments were distributed to a total of 290 subjects in twenty orthopaedic practices throughout the United States and Canada. Of the 290 patients, seventy each had a diagnosis in the categories of foot and ankle, sports/knee, and hip and knee and forty each had a diagnosis in the categories of trauma and rehabilitation. Retests to be taken twenty-four hours after the first test were distributed to subsamples of patients for each instrument. Seventy-one one-year follow-up questionnaires (twenty-five Sports/Knee, twenty-five Foot and Ankle, sixteen Hip and Knee, and five Lower Limb Core instruments) were returned. RESULTS The Lower Limb Core Scale and the Hip and Knee Core Scale, each consisting of seven items addressing pain, stiffness and swelling, and function, performed at an acceptable level. Additional Sports/Knee and Foot and Ankle Modules proved to have internal and retest reliability of 0.80 or better, comparable with the values for well-established measures such as the Short Form-36 (SF-36). All of the new scales were moderately to strongly correlated with other measures of pain and function, such as physician ratings, the SF-36, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Seventy-one patients provided follow-up information for the analysis of sensitivity to change. The Lower Limb Core was found to contribute independently to the prediction of the transition score based on the patient and physician assessments of change. CONCLUSIONS The AAOS Lower Limb Instruments for outcomes assessment are highly reliable and are correlated with other measures for similar constructs. They are also sensitive to change in patient status. The Lower Limb Core Scale may be used with attribution of pain either to the lower limb or to a specific joint or side without sacrificing reliability. Combined with the SF-36, the AAOS outcomes assessment instruments comprehensively and efficiently measure outcomes in orthopaedic patients with lower-limb conditions.

Outcomes After a Single-Stage Procedure for Cell-Based Cartilage Repair A Prospective Clinical Safety Trial With 2-year Follow-up

Background: There are currently several approaches being pursued to treat focal defects of articular cartilage, each having specific advantages or challenges. A single-stage procedure that uses autologous cartilage fragments, Cartilage Autograft Implantation System (CAIS), is being evaluated in patients and may offer a clinically effective option. Purpose: To establish the safety of CAIS and to test whether CAIS improves quality of life by using standardized outcomes assessment tools. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: Patients (n = 29) were randomized (1:2) with the intent to treat with either a control (microfracture [MFX]) or an experimental (CAIS) procedure. Patients were followed at predetermined time points for 2 years using several standardized outcomes assessment tools (SF-36, International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS]). Magnetic resonance imaging was performed at baseline, 3 weeks, and 6, 12, and 24 months. Results: Lesion size and International Cartilage Repair Society (ICRS) grade were similar in both groups. General outcome measures (eg, physical component score of the SF-36) indicated an overall improvement in both groups, and no differences in the number of adverse effects were noted in comparisons between the CAIS and MFX groups. The IKDC score of the CAIS group was significantly higher (73.9 ± 14.72 at 12 months and 82.95 ± 14.88 at 24 months) compared with the MFX group (57.78 ± 18.31 at 12 months and 59.5 ± 13.44 at 24 months). Select subdomains (4/5) in the KOOS instrument were significantly different at 12 and 18 months, and all subdomains (Symptoms and Stiffness, Pain, Activities of Daily Living, Sports and Recreation, Knee-related Quality of Life) were significantly increased at 24 months in CAIS with scores of 88.47 ± 11.68, 90.64 ± 7.87, 97.29 ± 3.8, 78.16 ± 22.06, and 69 ± 23.15 compared with 75 ± 9.31, 78.94 ± 13.73, 89.46 ± 8.13, 51.67 ± 26.01, and 37.15 ± 21.67 in the MFX group. These significant improvements were maintained at 24 months in both IKDC and KOOS. Qualitative analysis of the imaging data did not note differences between the 2 groups in fill of the graft bed, tissue integration, or presence of subchondral cysts. Patients treated with MFX had a significantly higher incidence of intralesional osteophyte formation (54% and 70% of total number of lesions treated) at 6 and 12 months when compared with CAIS (8% and 25% of total number of lesions treated). Conclusion: The first clinical experience in using CAIS for treating patients with focal chondral defects indicates that it is a safe, feasible, and effective method that may improve long-term clinical outcomes.

Modification of the Bankart reconstruction with a suture anchor Report of a new technique

We assessed the effectiveness of a new suture anchor that has been designed to anchor sutures into a blind, straight hole drilled in bone. The strength of fixation in glenoid bone is 67 N for the No. 0 anchor and suture, and 82 N for the No. 2 device with suture. During 1988 and 1989, 32 patients underwent a modified Bankart reconstruction for recurrent anterior glenohumeral in stability at two centers as part of a prospective study of this modified technique. There were no complications as a result of the technique. The four surgeons involved agreed that the suture anchor simplified the procedure. Seventeen patients have been reviewed, with more than 1 year followup. Ninety-four percent had good to excellent results according to the Bankart rating scale. There was one recurrent dislocation in a football player.