The superficial medial collateral ligament reconstruction of the knee: effect of altering graft length on knee kinematics and stability.

PURPOSE: The purpose of this study was to evaluate and compare the resulting knee kinematics and stability of an anatomic superficial MCL (sMCL) reconstruction and a non-anatomic sMCL reconstruction. METHODS: In a cadaveric model, normal knee stability and kinematics were compared with sMCL deficient knees and with two experimental sMCL reconstructions. The first reconstruction (AnatRecon) attempted to anatomically reconstruct the sMCL. The second reconstruction (ShortRecon) used a shorter graft to mimic the effect of failing to reproduce the anatomic length of the sMCL. Changes in position of the femur with respect to the tibia were measured with an electromagnetic tracking system during simulated active knee extension and during passive knee stability testing in the sMCL intact knee, the sMCL deficient knee, and the two experimental reconstructions. RESULTS: Simulated active knee extension demonstrated a significant increase in external tibial rotation of ShortRecon compared to AnatRecon between 30° and 80° of knee flexion (mean difference <3.0° over the range of knee flexion angles; P < 0.008), and a significant increase in external tibial rotation of ShortRecon compared to the intact sMCL was found at 60° and 70° of knee flexion (mean difference <2.0°over the range of knee flexion angles; P < 0.008). Passive joint stability testing demonstrated that division of the sMCL produced approximately 6° of valgus laxity at 30° of knee flexion and increased external tibial rotation of approximately 5° at 30°, 9° at 60°, and 10° at 90° of knee flexion, respectively. AnatRecon restored normal knee kinematics and stability. Additionally, passive stability testing demonstrated a significant increase in external tibial rotation of ShortRecon compared to AnatRecon at 60° (mean difference = 3.7°; P < 0.05) and 90° of knee flexion (mean difference = 4.9°; P < 0.05). CONCLUSION: Anatomic reconstruction of the sMCL effectively restored knee kinematics and stability in the sMCL deficient knee. Altering the normal ligament length resulted in measurable changes in knee kinematics and stability. This study suggests that in cases of chronic valgus knee instability, anatomic sMCL reconstruction would provide better results than non-anatomic sMCL reconstruction.

Effect of Medicaid managed care on pregnancy complications.

OBJECTIVE: This study examined the impact of managed care on hospital obstetric outcomes in Medicaid-sponsored women. METHODS: The study sample consisted of a total of 525,517 maternal deliveries for singleton births from three payer groups, Medicaid managed care, Medicaid fee-for-service, and private managed care in 439 short-term-stay nonfederal hospitals in California and Florida. Quality of care comparisons were made using six indicators. Data were derived from linked computer files of birth certificates, hospital discharge abstracts, Medicaid eligibility records, Medicaid health care claims, and surveys of hospital characteristics. RESULTS: The overall multivariate likelihood of an adverse maternal outcome during hospitalization for a delivery was not significantly different between Medicaid managed care and Medicaid fee-for-service groups in California and Florida. However, mothers in the Medicaid managed care group compared with mothers in the private managed care group experienced a higher likelihood of eclampsia (California) (adjusted odds ratio = 1.26; 95% confidence interval 1.05, 1.57; P = .04). CONCLUSION: Overall, managed care has not adversely affected pregnancy outcomes in Medicaid-sponsored women. Yet, payer system changes may be insufficient to achieve complete parity of outcomes relative to private managed care patients.

Primary repair of patellar tendon rupture without augmentation.

Repair of patellar tendon ruptures has often relied on cerclage augmentation and prolonged immobilization in extension. We are reporting our experience with avulsion injuries as well as midsubstance ruptures, both treated with primary repair without augmentation, allowing early mobilization in the athlete less than 40 years of age. Repairs were performed to allow knee flexion to more than 60 degrees. Rehabilitation was performed with heel slides, allowing flexion to 45 degrees for the first 3 weeks, increasing to 90 degrees at 3 to 6 weeks, and thereafter without restriction. An accelerated weightbearing and muscle strengthening program was adopted. At a mean follow-up of 2.6 years (range, 20 to 61 months), 12 patients had returned to their previous levels of activity. No loss of extension or extensor lag was noted; mean flexion loss was 5 degrees. Patellofemoral symptoms and signs were present in five patients, but activity was limited in only two. Mean peak torque at 60 deg/sec was 92% (range, 73% to 105%). Mean Lysholm score was 94 +/- 2.5 points. Primary repair with immediate, protected range of motion resulted in uniformly excellent results and obviated the need for manipulation or subsequent hardware removal.

Enhancing clinical pathway placement.

Soaring health care costs have fueled the immense growth in managed care. To contain these costs, health care organizations have turned to clinical pathways. However, clinical pathways cannot do an effective job if health care personnel are not aware of their existence. The article presents a simple, effective, and efficient method to increase placement of clinical pathways in inpatient medical records.

Patellar strain and patellofemoral contact after bone-patellar tendon-bone harvest for anterior cruciate ligament reconstruction.

OBJECTIVE: To characterize the morbific consequences of harvesting a patellar tendon graft for use in reconstructing the anterior cruciate ligament (ACL) of the knee, specifically, (1) to measure changes in patellar strain and patellofemoral contact due to graft harvest, (2) to evaluate the ability of bone-grafting the patellar defect to mitigate these effects, and (3) to characterize failure of the extensor mechanism after harvest of a patellar tendon graft. DESIGN: Twenty-two cadaver knee joints were tested before and after harvest of a patellar tendon graft and after filling the patellar defect with polymethylmethacrylate to simulate a healed bone graft, Knees were positioned in 30 degrees, 60 degrees, and 90 degrees flexion and loaded while measuring axial strain in the anterior patella and patellofemoral contact. Knees were then loaded to failure. RESULTS: Harvest of the graft produced increases in axial strain at all flexion angles. Filling the defect restored axial strain to normal values. Patellofemoral contact in the presence of a defect, either filled or empty, was not different from contact for intact patellae. Most knees failed by transpatellar fracture; mean extension moment at failure was 112.8Nm. The best predictors of failure were age and gender. CONCLUSION: Patients undergoing ACL reconstruction with a patellar tendon graft are at increased risk of anterior knee pain and disruption of the extensor mechanism. Bone-grafting the patellar defect created by graft harvest can reduce these risks. Our findings underscore the importance of carefully controlled rehabilitation and suggest that if an accelerated program of rehabilitation is anticipated, the patellar defect should be bone-grafted. Older patients, particularly women, are at increased risk of catastrophic failure of the knee extensor mechanism after ACL reconstruction using patellar tendon graft.

The rotator cuff opposes superior translation of the humeral head.

To determine the influence of rotator cuff muscle activity on humeral head migration relative to the glenoid during active arm elevation we studied five fresh cadaveric shoulders. The shoulder girdles were mounted in an apparatus that simulated contraction of the deltoid and rotator cuff muscles while maintaining the normal scapulothoracic relationship. The arms were abducted using four different configurations of simulated muscle activity: deltoid alone; deltoid and supraspinatus; deltoid, infraspinatus, teres minor, and subscapularis; and deltoid, supraspinatus, infraspinatus, teres minor, and subscapularis. For each simulated muscle configuration the vertical position of the humeral head in relation to the glenoid was determined at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of abduction using digitized anteroposterior radiographs. Both muscle activity and abduction angle significantly influenced the glenohumeral relationship. With simulated activity of the entire rotator cuff, the geometric center of the humeral head was centered in the glenoid at 30 degrees but had moved 1.5 mm superiorly by 120 degrees. Abduction without the subscapularis, infraspinatus, and teres minor muscles caused significant superiorly directed shifts in humeral head position as did abduction using only the deltoid muscle. These results support the possible use of selective strengthening exercises for the infraspinatus, teres minor, and subscapularis muscles in treatment of the impingement syndrome.

The entire rotator cuff contributes to elevation of the arm.

The function of the infraspinatus, teres minor, and subscapularis during elevation of the arm remains poorly defined. These muscles may generate moments that contribute to abduction of the arm, although they frequently are classified as humeral depressors. The purposes of this study were to measure the contributions to abduction made by the more inferiorly positioned rotator cuff muscles relative to the contributions of the supraspinatus and to determine the range of motion at which the muscles are most effective. Five fresh cadaveric shoulder girdles were mounted in an apparatus designed to simulate contraction of the deltoid and rotator cuff while maintaining the normal relationship between glenohumeral and scapulothoracic motions. The deltoid force required for elevation was measured without simulated contraction of the rotator cuff and with simulated contraction of the entire rotator cuff, of the supraspinatus only, and of the infraspinatus-teres minor and subscapularis only. A significant reduction in deltoid force when other muscle activity was added indicated that the additions contributed significantly to abduction. The deltoid force required with concurrent contraction of the entire rotator cuff averaged 41% less than with the deltoid alone but was not significantly different than with the deltoid and supraspinatus or with the deltoid, infraspinatus-teres minor, and subscapularis. Concurrent application of forces to the supraspinatus or the infraspinatus-teres minor and subscapularis significantly reduced the required deltoid force over the range of motion studied by an average of 28 and 36%, respectively. The contributions of the rotator cuff muscles to abduction of the arm were greatest at low abduction angles (30 and 60 degrees) and were insignificant by 120 degrees. The infraspinatus-teres minor and subscapularis contribute significantly to abduction: their contribution was equal to that of the supraspinatus and, like the supraspinatus, they are most effective during the first 90 degrees of abduction.

Ankle dislocation.

From 1980 to 1991, 14 patients with pure ankle dislocation unassociated with fracture were identified. All patients were young adults (18-41 years of age) with a male preponderance (11 of 14). The cause of injury in nine of the 14 cases was a motor vehicle accident and in the remainder, sporting events or fall from a height. Thirteen of the 14 injuries were open, and 12 patients underwent lateral ligamentous repair. Twelve of the 14 patients were available for follow-up, which ranged from 15 to 122 months. Two patients had poor results; the remainder (10 of 12) had good and excellent results. Interestingly, no patient had signs or symptoms of instability. One patient required immediate below-the-knee amputation for open dislocation associated with avulsion of soft tissue and neurovascular structures.

Effects of partial patellectomy and reattachment of the patellar tendon on patellofemoral contact areas and pressures.

We used a previously reported experimental method to measure patellofemoral contact areas and pressures in four pairs of human cadaveric knees before and after a partial patellectomy. The knee joints were loaded by application of a flexion moment, which was resisted by the extension moment of the quadriceps mechanism. Patellofemoral contact was measured with the use of pressure-sensitive film, at 30, 60, and 90 degrees of flexion of the knee. Partial patellectomy decreased the patellofemoral contact area and increased pressure. We observed alterations in the patterns of contact, including a proximal shift in patellofemoral contact, after partial patellectomy. An anterior reattachment of the patellar tendon significantly minimized the effects of 20 and 40 per cent patellectomies (p < 0.05). After a 60 per cent patellectomy, patellofemoral contact was altered markedly, with the contact area reduced to less than 50 per cent of the control values regardless of the position of the patellar tendon reattachment.

Arthroscopic versus open debridement of penetrating knee joint injuries.

Arthroscopic debridement of penetrating knee joint injuries has become a common treatment method. A comparative study was undertaken to compare this method with open joint debridement. Fourteen penetrating knee joint injuries (fourteen patients) were treated by arthroscopic examination and debridement and were compared to sixteen penetrating knee joint injuries (fifteen patients) treated by open debridement. There were no resultant infections or operative complications in either group. Of note, the arthroscopic debridement group had a shorter postoperative hospital stay [mean of 1.6 days compared to a mean of 2.6 days in the open debridement group (p < 0.02)], a significant incidence of additional intra-articular injuries detected (p < 0.01), less postoperative pain, and a superior cosmetic result. We conclude that arthroscopic debridement of penetrating knee joint injuries is a safe and effective method of treatment, providing additional diagnostic information while minimizing morbidity and reducing hospital stay.

Reconstruction of the lateral ankle ligaments. A biomechanical analysis.

UNLABELLED: The purpose of this study was to perform a biomechanical analysis of several commonly performed operative procedures used to stabilize the lateral ankle. We performed the Evans, Watson-Jones, and Chrisman-Snook procedures on 15 cadaveric ankles and tested the ankles for stability, motion, and isometry of graft placement. The Evans procedure allowed increased anterior displacement, internal rotation, and tilt of the talus when compared to ankles with intact ligaments. Subtalar joint motion was restricted by the Evans procedure. The Watson-Jones procedure controlled internal rotation and anterior displacement of the talus, but was less effective in controlling talar tilt and also restricted subtalar joint motion. The Chrisman-Snook procedure allowed increased internal rotation and anterior displacement of the talus when compared to ankles with intact ligaments. The procedure was effective in limiting talar tilt, but restricted subtalar joint motion. Based on the biomechanical data obtained, we devised a lateral ankle reconstruction with bone tunnels that reproduce the anatomic orientation of both the anterior talofibular and calcaneofibular ligaments. This ankle ligament reconstruction resists anterior displacement, internal rotation, and talar tilt without restricting subtalar joint motion. CLINICAL RELEVANCE: We found considerable mechanical differences among the more commonly performed lateral ankle reconstructions. It is possible to locate bone tunnels and graft placement so that a more anatomic configuration is achieved.

Medical social work long-term care referrals for people with HIV infection.

Hospital social workers were surveyed to identify referral efforts and outcomes for clients with human immunodeficiency virus (HIV) infection who required long-term placement. Over a three-month period, none of the 42 identified clients was admitted to a nursing home. In two-thirds of the cases, social workers contacted only one facility, and in about one-sixth of the cases, workers reported no placement attempts. Clients remained in the hospital a median overstay of eight days beyond acute care needs, representing 205 aggregate days that could have been spent in less intensive settings. Workers made few placement attempts because of beliefs that they would be unsuccessful or that nursing homes would not accept admissions. Increased communication and education both for referring workers and for long-term care facilities may improve the referral process, reduce costs, and decrease emotional distress for people infected with HIV.

Prospective evaluation of arthroscopically assisted anterior cruciate ligament reconstruction. Patellar tendon versus semitendinosus and gracilis tendons.

Eighty consecutive patients with chronic laxity due to a torn ACL underwent arthroscopically assisted reconstruction with either autogenous patellar tendon or doubled semitendinosus and gracilis tendons. Reconstructions were performed on a one-to-one alternating basis. Preoperatively, no significant differences between the two groups were noted with respect to age, sex, level of activity, and degree of laxity (chi square analysis). A standard rehabilitation regimen was used for all patients after surgery including immediate passive knee extension, early stationary cycling, protected weightbearing for 6 weeks, avoidance of resisted terminal knee extension until 6 months, and return to activity at 10 to 12 months postoperatively. Seventy-two patients were evaluated at a minimum of 24 months postoperatively (range, 24 to 40 months). No significant differences were noted between groups with respect to subjective complaints, functional level, or objective laxity evaluation, including KT-1000 measurements. Seventeen of 72 patients (24%) experienced anterior knee pain after ACL reconstruction. Overall, 46 of 72 patients (64%) returned to their preinjury level of activity. Mean KT-1000 scores were 1.6 +/- 1.4 mm for the patellar tendon group and 1.9 +/- 1.3 mm for the semitendinosus and gracilis tendons group. This study did find a statistically significant weakness in peak hamstrings torque at 60 deg/sec when reconstruction was performed with double-looped semitendinosus and gracilis tendons.

Measuring the quality of care for the cancer patient.

In recent years, the efforts to better define quality of patient care have focused on attempts to improve on the measurement of quality. These efforts raise three questions: (1) Why attempt to measure quality? (2) What is the best way to measure quality of care of the cancer patient? and (3) What must be done to achieve this? Three main reasons for measuring quality of patient care are to describe the current state, plan strategies for improvement, and implement and monitor improvements. To measure quality, both the definition of quality and the tools available for measurement must be addressed. The difficulty in developing a measurable definition of quality is achieving agreement on the measurable components of quality. The tools to measure quality have evolved to focus on monitoring of key indicators for comparative use. The utility of indicators lies in demonstrating that they have the capacity to identify opportunities for improving care. The Joint Commission is improving measurement tools through the development and testing of oncology indicators for reliability and the capacity to identify opportunities for improving care. The development and teaching of new quality improvement methods to health care professionals also is necessary.

Monoclonal antibodies detect monocyte/macrophage activation and differentiation antigens and identify functionally distinct subpopulations of human rheumatoid synovial tissue macrophages.

Monoclonal antibodies (MAbs) to functionally heterogeneous populations of human rheumatoid arthritis (RA) synovial tissue macrophages and lipopolysaccharide (LPS)-activated U937 cells were generated. These MAbs were used to characterize macrophages in situ in the synovial pannus and to study relative antigen expression on the surface of cells isolated from the synovium and from normal peripheral blood. Monoclonal antibody 3D8, an anti-CD13 MAb, reacts with an antigen expressed on the surface of blood monocytes and is a monocyte activation-related antigen that is upregulated by exposure of monocytes to interferon-gamma (IFN-gamma) and LPS. The expression of the 3D8 antigen increases in parallel with MHC class II antigen expression and also is upregulated in culture as monocytes mature to macrophages. 3D8 antigen is expressed strongly on RA synovial tissue lining cells, which are thought to be composed of macrophages. 8D7 antigen expression, detected by MAb 8D7, increases on blood monocytes on cellular activation with LPS and interferon-gamma, but in contrast to the 3D8 antigen, does not increase with monocyte maturation in vitro. The 8D7 antigen is expressed differentially on density-defined macrophage subpopulations isolated from RA synovial tissue and is expressed more strongly on macrophages that are nonangiogenic than those that are angiogenic.