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Successful shoulder surgery, whether open or arthroscopic, depends on the surgeon's knowledge of anatomy and pathology. Over the last 10 years, arthroscopic applications for shoulder surgery have become increasingly popular. As with arthroscopy of the knee, new applications are constantly being developed and defined. The most common current applications of shoulder arthroscopy are to confirm clinical diagnosis, establish specific details of intra- and extra-articular pathology, perform surgical procedures relative to pathology, and plan for subsequent management. Over the last several years, arthroscopic techniques have been developed to replace some of the more traditional open procedures. There is no question that there are definite advantages to an arthroscopic surgical procedure vs an open shoulder surgical procedure. These are reviewed in Table 1. Many of these advantages are similar arguments orthopaedic surgeons used in the past to justify knee arthroscopy. Although we would like to think of arthroscopic procedures as being easier and problem free, there are definite disadvantages that exist and must be recognized. There has been a great deal of initial enthusiasm over many different arthroscopic procedures, but it must be remembered that this is a new area with few good long-term studies. There is little doubt that arthros5opy of the shoulder has evolved at a much slower pace than that of the knee. However, since 1980 there has been a definite increase in the number of clinical and scientific publications pertaining to shoulder arthroscopy. What was once regarded as another "arthroscopic gimmick" has become a very important tool in the diagnostic and therapeutic approach to many different shoulder problems. The purpose of this introductory article is to give the reader an overview of the current applications, positioning, equipment, and complications of shoulder arthroscopy. Many of the procedures mentioned in this brief overview are covered in detail elsewhere in this issue.

Traumatic knee dislocations leading to multiple ligament injury are relatively uncommon but not rare injuries. These injuries demand prompt and appropriate attention; they represent one of the few true orthopedic emergencies because of their potentially limb-threatening nature. Because many of these injuries reduce spontaneously near the time of the injury, the true incidence is unknown but is thought to be relatively low. 24 , 31 , 38 Out of two million admissions during a 50-year period at the Mayo Clinic, Hoover 15 reported only 14 cases of knee dislocations. At a major level 1 trauma center in New Mexico, only 50 patients with knee dislocations were admitted between 1987 and 1994. 44 At the University of Pittsburgh, 52 patients have been treated for acute and chronic knee dislocations between 1990 and 1997, reflecting a tendency to refer these complex cases to centers familiar with their relative severity. The ideal management of ligamentous injury in the dislocated knee remains controversial. Because literature is relatively sparse and includes a heterogeneity of injuries, treatment protocols and evaluation methods will vary by specialty and region. Nonoperative management emphasizing immobilization, although possibly leading to a stable knee, is frequently associated with stiffness and dysfunction. 1 Alternatively, more aggressive nonoperative management using early range of motion will restore functional motion at the expense of knee stability. 41 O'Donoghue, 28 Meyers et al 24 , 25 and Shields et al 38 were the earliest authors to recommend acute repair of all torn ligaments to achieve the best results. Most contemporary reports include recommendations for early ligament repair or reconstruction when necessary. * The focus of this review is on the acute management of the dislocated knee; however, except for the management of vascular injury, the same principles and techniques that apply to the acute injury also generally apply to the chronically unstable knee sustaining a previous dislocation.

The ultrastructural anatomy of collagen fibril diameters in the cruciate and meniscofemoral ligaments, from four young human cadaver knees (mean age, 20 years, range, 17-22 years) was studied using transmission electron microscopy. Samples were harvested from the proximal, middle, and distal regions of the anterior and posterior cruciate ligaments, and the meniscofemoral ligament. Photomicrographs were taken and assessed quantitatively using image analysis software to determine the collagen fibril diameters and eccentricities, and the percentage of total cross sectional area occupied by collagen. The collagen fibril diameter for the anterior cruciate ligament was found to be largest in the distal region but it decreased as it moved proximally. The posterior cruciate ligament had an opposite trend because it decreased from the proximal to the distal region. For the meniscofemoral ligament, the fibrils of the middle region were larger than those of the proximal and distal regions. The percentage of total cross sectional area occupied by collagen, however, did not vary significantly between regions. Fibril eccentricity also varied little between ligament or location. The variability observed in fibril diameters may account for the different mechanical properties of the ligaments.

Clinical outcomes of reconstructive surgery for injuries to the posterior cruciate ligament (PCL) of the knee have been unsatisfactory, with persistent instability predisposing patients to early degenerative joint disease [Clancy, 1983]. One explanation for these outcomes has been the high incidence (up to 60%) of associated injuries to the posterolateral structures (PLS), which include the lateral collateral ligament (LCL) and popliteus complex. Combined PCL/PLS injuries are particularly debilitating because restraints to both posterior tibial translation and external rotation are lost [Grood, 1988]. Further, PLS injuries are difficult to reconstruct due to its complex anatomy; thus, often only the PCL is reconstructed when combined injuries occur.

Study Objectives: (1) To introduce anesthesia clinical pathways as a management tool to improve the quality of care; (2) to use the Procedural Times Glossary published by the Association of Anesthesia Clinical Directors (AACD) as a template for data collection and analysis; and (3) to determine the effects of anesthesia clinical pathways on surgical processes, outcomes, and costs in common ambulatory orthopedic surgery. Design: Hospital database and patient chart review of consecutive patients undergoing anterior cruciate ligament reconstruction (ACLR) during academic years (AY) 1995–1996 and 1996–1997. Patient data from AY 1995–1996, during which no intraoperative anesthesia clinical pathways existed, served as historical controls. Data from AY 1996–1997, during which intraoperative anesthesia clinical pathways were used, served as the treatment group. Regional anesthesia options were routinely offered to patients in the clinical pathway. Setting: Ambulatory surgery center in a teaching hospital. Measurements and Main Results: The records of 503 ASA physical status I and II patients were reviewed. 1996–1997 patients underwent clinical pathway anesthesia care in which the intraoperative and postoperative anesthesia process was standardized with respect to symptom management, drugs, and equipment used. 1995–1996 patients did not have a standardized intraoperative and postoperative anesthetic course with respect to the management of common symptoms or to specific drugs and supplies used. Intervals described in the AACD Procedural Times Glossary, anesthesia drug and supply costs, and patient outcome variables (postoperative nursing interventions required and unexpected admissions), as influenced by the use of the anesthesia clinical pathway, were measured. Clinical pathway anesthesia care for ACLR in 1996–1997, which actively incorporated regional anesthesia options, reduced pharmacy and materials cost variability; slightly increased turnover time; improved intraoperative anesthesia and surgical efficiency, recovery times, and unexpected admission rates; and decreased the number of required nursing interventions for common postoperative symptoms. Conclusions: Clinical pathway patient management systems in anesthesia care are likely to produce useful outcome data of current practice patterns when compared with historical controls. This management tool may be useful in simultaneously containing costs and improving process efficiency and patient outcomes.

The purpose of the present study was to demonstrate the reliability, validity, and responsiveness of the Activities of Daily Living Scale of the Knee Outcome Survey, a patient-reported measure of functional limitations imposed by pathological disorders and impairments of the knee during activities of daily living. The study comprised 397 patients; 213 were male, 156 were female, and the gender was not recorded for the remaining twenty-eight. The mean age of the patients was 33.3 years (range, twelve to seventy-six years). The patients were referred to physical therapy because of a wide variety of disorders of the knee, including ligamentous and meniscal injuries, patellofemoral pain, and osteoarthrosis. The Activities of Daily Living Scale was administered four times during an eight-week period: at the time of the initial evaluation and after one, four, and eight weeks of therapy. Concurrent measures of function included the Lysholm Knee Scale and several global measures of function. The subjects also provided an assessment of the change in function, with responses ranging from greatly worse to greatly better, at one, four, and eight weeks. The Activities of Daily Living Scale was administered to an additional sample of fifty-two patients (thirty-two male and twenty female patients with a mean age of 31.6 years [range, fourteen to sixty-six years]) before and after treatment within a single day to establish test-retest reliability. Factor analysis revealed two dominant factors: one that reflected a combination of symptoms and functional limitations and the other, only symptoms. The internal consistency of the Activities of Daily Living Scale was substantially higher than that of the Lysholm Knee Scale (coefficient alpha, 0.92 to 0.93 compared with 0.60 to 0.73), resulting in a smaller standard error of measurement for the former scale. Validity was demonstrated by moderately strong correlations with concurrent measures of function, including the Lysholm Knee Scale (r = 0.78 to 0.86) and the global assessment of function as measured on a scale ranging from 0 to 100 points (r = 0.66 to 0.75). Analysis of variance with repeated measures revealed significant improvements in the score on the Activities of Daily Living Scale during the eight weeks of physical therapy (F2,236 = 108.13; p < 0.0001); post hoc testing indicated that the change in the score at eight weeks was significantly greater than the change at four weeks and that the change at four weeks was significantly greater than that at one week (p < 0.0001 for both). As had been hypothesized, the patients in whom the knee had somewhat improved had a significantly smaller change in the score, both at four weeks (F1,189 = 33.50; p < 0.001) and at eight weeks (F1,156 = 22.48; p < 0.001), compared with those in whom the knee had greatly improved. The test-retest reliability coefficient (intraclass correlation coefficient[2,1]) was 0.97. These results suggest that the Activities of Daily Living Scale is a reliable, valid, and responsive instrument for the assessment of functional limitations that result from a wide variety of pathological disorders and impairments of the knee.

Thirty patients having had anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) autograft and thirty patients having had ACL reconstruction with hamstring (HS) autograft were enrolled. All procedures were performed using an endoscopic technique with identical postoperative rehabilitation, such that the only variable was the type of graft and its fixation. Lateral and 45 degrees posteroanterior (PA) weightbearing radiographs were performed in each patient at 6-12 (mean 9) months postoperatively in the HS group and 9-22 (mean 13) months postoperatively in the PT group. The sclerotic margins of the tunnel were measured at the widest dimension of the tunnel by a single observer and were compared with the initially drilled tunnel size after correction for radiographic magnification. For the BPTB group, all bone plugs appeared to be incorporated radiographically. On the femoral side, the bone plug was incorporated at the roof of the intercondylar notch, such that no tunnel measurement could be made. Well-defined sclerotic margins were always present at the tibial and femoral tunnels for the HS group and at the tibial tunnel for the BPTB group. The mean percentage increase in tunnel size in the PA view was 9.7%+/-14.7% for the BPTB tibial tunnel, 20.9%+/-13.4% for the HS tibial tunnel, and 30.2%+/-17.2% for the HS femoral tunnel. The mean percentage increase in tunnel size in the lateral view was 14.4%+/-16.1% for the BPTB tibial tunnel, 25.5%+/-16.7% for the HS tibial tunnel, and 28.1%+/-14.7% for the HS femoral tunnel. The difference in HS and BPTB tibial tunnel expansion on both the PA and lateral views was statistically significant (P = 0.003 and P = 0.01, respectively). Inter-observer variability was excellent with an intra-class correlation coefficient of 0.92. Tunnel expansion was significantly greater following ACL reconstruction using HS autografts than in those using BPTB autografts. The points of fixation for the HS grafts are at a greater distance from the normal insertion site and biomechanical point of action of the ACL than the points of fixation for BPTB grafts. We believe that this greater distance creates a potentially larger force moment during graft cycling which may lead to greater expansion of bone tunnels.

Koehler RJ, Amsdell S, Arendt EA, Bisson LJ, Braman JP, Butler A, Cosgarea AJ, Harner CD, Garrett WE, Olson T, Warme WJ, Nicandri GT. The Arthroscopic Surgical Skill Evaluation Tool (ASSET). Am J Sports Med. 2013;41(6):1229-1237. (Original DOI: 10.1177/0363546513483535 ) Author Jonathan P. Braman’s name appeared incorrectly in this article. The correct author information appears above.

To define the positive predictive value (PPV) for the magnetic resonance (MR) imaging diagnosis of meniscocapsular separation in the knee.The MR reports of 52 patients aged 16-75 years who had a prospective MR diagnosis of meniscocapsular injury were correlated with arthroscopic results. MR images obtained in 50 of these patients were retrospectively reviewed for specific signs of meniscocapsular separation, which included meniscal displacement, peripheral meniscal corner tears, increased perimeniscal signal intensity, fluid deep to the medial collateral ligament, and abnormal lateral fascicles. MR findings were correlated with arthroscopic findings.For the prospective MR interpretations, the PPV for meniscocapsular separation was 9% medially and 13% laterally. Meniscal displacement (measured from the meniscal edge to the tibia) was as great as 10 mm medially or 13 mm laterally without meniscocapsular tears at arthroscopy. Meniscal displacement did not correlate with effusion. Meniscal corner tears had a PPV of 0% medially and 50% laterally. Fluid at the meniscocapsular border and fluid deep to the medial collateral ligament were poor predictors of meniscocapsular abnormalities. Abnormal-appearing meniscal fascicles had a PPV of 8% for lateral meniscocapsular separation.The PPV for the MR diagnosis of meniscocapsular separation is low; the reported MR signs correlate poorly with arthroscopic findings.

Treatment of meniscal injuries in the knee has evolved over the past three decades. New research regarding the functional roles of the menisci has increased emphasis on the preservation of meniscal tissue. Meniscal transplantation has developed as a surgical technique for individuals whose menisci have been compromised through trauma or previous meniscectomy. The purpose of this article is to review the current literature regarding meniscal function, the deleterious effects of meniscectomy, and the development of transplantation of allograft menisci as a surgical technique. A case study of a 28-year-old male undergoing medial meniscus transplantation is presented, with emphasis on the development of postoperative rehabilitation guidelines.

Revision anterior cruciate ligament surgery will become more common as the number of primary anterior cruciate ligament reconstructions increases. Also contributing to this increase are those patients who had anterior cruciate ligament reconstruction using synthetic ligaments and other nonanatomic techniques that are no longer used. Preoperative planning is imperative to a successful outcome. This begins with determining the primary, and often times secondary, mechanism of failure for each patient. The determination of the etiology of failure is the first step in a carefully constructed preoperative plan, including the type of revision, skin incision, graft removal, hardware removal, tunnel placement, graft selection, graft fixation, and rehabilitation. The precise preoperative plan should have enough flexibility to accommodate unanticipated findings in the operating room. Rehabilitation protocols must be designed specifically for the revision surgery patient and be flexible enough to accommodate changes based on surgical findings and techniques. Finally, the importance of counseling the patient preoperatively regarding the potential results which, in general, are somewhat less satisfactory than with most primary reconstructions, must be emphasized. However, with proper planning, attention to detail, and adherence to basic principles of anterior cruciate ligament reconstruction, revision anterior cruciate ligament surgery can provide a satisfying solution to difficult knee instability cases.

The use of soft tissue allografts in knee ligament reconstruction has an important role in the surgical treatment of patients in the field of sports medicine. Currently, the most common uses for soft tissue allografts involve isolated anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction, revision ACL and PCL reconstruction, medial collateral ligament augmentation, lateral collateral ligament augmentation, and combined ligamentous injuries of the knee. This chapter will highlight the current basic science, clinical knowledge, and controversies regarding the use of fresh frozen allograft tissues. In addition, we report the results of our early clinical experience using fresh frozen shft tissue allografts in knee ligament reconstruction. We will be focussing our attention on fresh frozen allografts as this has been our preferred allograft of choice since 1985. The use of freeze-dried allografts will only be mentioned briefly in this chapter.

Objectives: Return to sports (RTS) is a primary goal for ACL reconstruction. Recent studies indicate that return to prior level of sports participation is poor with only 45% of patients having returned to sport.1 The purpose of this study was to evaluate return to pre-injury level of sports participation after ACL reconstruction using a strict comprehensive definition for RTS. Methods: Participants who were 1 to 5 years after ACL reconstruction completed a survey to determine their pre-and post-surgery sports activity levels. Comprehensive return to pre-injury level of sports (comprehensive RTS) was operationally defined as returning to the same type and frequency of sports and same Marx Activity Score (MAS) as before injury. Patients also answered a global question on whether they had returned to their pre-injury level of sports (global RTS). The International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) was used to compare symptoms and function between patients who did and did not meet comprehensive RTS criteria. Results: One hundred sixty eight participants (mean age, 28.8±10.9 years) completed the survey. Using comprehensive RTS criteria, 69 (41.1%) participants returned to their pre-injury level of sports. Based on the global RTS, 79 (47%) reported they had returned to their pre-injury level of sports. Fifty nine (74.7%) of the 79 individuals that reported global RTS met the comprehensive RTS criteria. Patients who met the comprehensive RTS criteria had fewer symptoms and better function based on the IKDC-SKF than those who did not (87.5±10.6 vs. 80.1±13.7, pConclusion: RTS is more common if based on a global RTS question than if measured by strict comprehensive criteria that combine return to the same type and frequency of sports and MAS. Patients who do not meet comprehensive RTS criteria demonstrate poorer function than those that do. A global rating of RTS may overestimate the true RTS rate by 25%. Fear of re-injury, ongoing knee problems, and lack of confidence play a greater role in preventing RTS than lifestyle changes. These issues need to be addressed to improve RTS after ACL reconstruction

To study the structural and functional properties of the human posterior cruciate ligament complex, we meas ured the cross-sectional shape and area of the anterior cruciate, posterior cruciate, and meniscofemoral liga ments in eight cadaveric knees. The posterior cruciate ligament increased in cross-sectional area from tibia to femur, and the anterior cruciate ligament area de creased from tibia to femur. The meniscofemoral liga ments did not change shape in their course from the lateral meniscus to their femoral insertions. The pos terior cruciate ligament cross-sectional area was ap proximately 50% and 20% greater than that of the an terior cruciate ligament at the femur and tibia, respectively. The meniscofemoral ligaments averaged approximately 22% of the entire cross-sectional area of the posterior cruciate ligament. The insertion sites of the anterior and posterior cruciate ligaments were evalu ated. The insertion sites of the anterior and posterior cruciate ligaments were 300% to 500% larger than the cross-section of their respective midsubstances. We determined, through transmission electron microscopy, fibril size within the anterior and posterior cruciate liga ment complex from the femur to the tibia. The posterior cruciate ligament becomes increasingly larger from the tibial to the femoral insertions, and the anterior cruciate ligament becomes smaller toward the femoral insertion. We evaluated the biomechanical properties of the femur-posterior cruciate ligament-tibia complex using 14 additional human cadaveric knees. The posterior cruciate ligament was divided into two functional com ponents : the anterolateral, which is taut in knee flexion, and the posteromedial, which is taut in knee extension. The anterolateral component had a significantly greater linear stiffness and ultimate load than both the postero medial component and meniscofemoral ligaments. The anterolateral component and the meniscofemoral liga ments displayed similar elastic moduli, which were both significantly greater than that of the posteromedial com ponent.

A cadaveric study was performed to determine the insertion-site anatomy of the human menisci, their topographical relationships to adjacent intra-articular structures, and which arthroscopic portal provides for optimal visualization of each insertion site. Fifteen fresh-frozen cadaver knees were studied (ages 48 to 63 years). Ten knees underwent arthroscopy using four standard arthroscopic portals. Visualization and placement of an arthroscopic guide over each meniscal horn insertion site was attempted through the four arthroscopic portals. Guide wires were drilled to mark horn insertions followed by a gross dissection to evaluate accuracy of the guide wire gross dissection to evaluate accuracy of the guide wire placement and to isolate meniscal horn insertion sites. Insertion sites were outlined and evaluated for size and topographical relationships to other intra-articular structures. Five additional knees were dissected free of all soft tissues except the tibial insertions of the meniscal roots and anterior cruciate ligament/posterior cruciate ligament. Each tibia was mounted in a jig and a digitizing system was used to record coordinates of points along the outline of each bony meniscal horn insertion site, the ACL tibial insertion, and the articular surface of each tibial plateau. The x, y, z coordinates for each point were calculated and loaded into a computer program allowing for surface area determination and computer-generated topographical maps to assess relative position of each specific insertion site. Placement of the arthroscope in the anterolateral portal allows optimal visualization and guide wire placement for both lateral meniscal horn insertion sites. Medial meniscal anterior and posterior horn insertion sites are best visualized with the arthroscope in the anteromedial and posteromedial portals respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

As an important step toward determination of the function of cruciate ligaments, the cross-sectional shapes and areas of the anterior cruciate, posterior cruciate, and meniscofemoral ligaments were evaluated in situ within the same knee with use of a laser micrometer system. Measurements were made in eight human cadaveric knees at five levels along the midsubstance of each ligament, with the knee at 0 degree, 30 degrees, 60 degrees, and 90 degrees of flexion. The posterior cruciate ligament was found to be widest in the medial-lateral direction, whereas the anterior cruciate ligament usually was larger in the anterior-posterior direction. The cross-sectional shapes of the anterior cruciate ligament generally were noted to be more circular along the entire midsubstance than were those of the posterior cruciate ligament. In contrast, the cross-sectional shapes of the posterior cruciate ligament were more circular near the tibia, becoming progressively more elongated toward the femur. The meniscofemoral ligaments were more circular than the cruciate ligaments, with an occasional medial-lateral widening similar to that of the posterior cruciate ligament. The cross-sectional area of both the cruciate ligaments changed along the length of the midsubstance, with the anterior cruciate ligament becoming slightly larger distally and the posterior cruciate ligament enlarging proximally. The angle of flexion of the knee was not found to have a significant effect on the cross-sectional areas of the ligaments but was noted to alter the cross-sectional shapes.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of motion following knee ligament surgery is a common and potentially serious complication. Loss of extension is most common following anterior cruciate ligament reconstruction, and loss of flexion is most common after posterior cruciate ligament reconstruction. The aetiology of loss of motion is multifactorial and includes impingement and capsulitis. The risk for loss of motion can be minimised by appropriate preoperative, intraoperative and postoperative intervention. Management of loss of motion depends on the cause and length of time following surgery.

The meniscofemoral ligaments (MFL) of 26 human cadaver knees were studied to determine their structural importance. The incidence of at least one MFL in each of the specimens studied was 100%, and 46% of the specimens had both MFL ligaments (Humphry and Wrisberg). Another 23% had a single Humphry ligament, and the remaining 31% had a single Wrisberg ligament. A laser micrometer system was used to measure cross-sectional shape and area. The average cross-sectional areas of the Humphry and Wrisberg ligaments were 7.8 +/- 4.7 mm2 and 6.7 +/- 4.1 mm2, respectively. In specimens with both a Humphry and Wrisberg ligament, the larger ligament area was on average 100% greater than the smaller ligament area. The average ratios of the cross sectional areas of Wrisberg and Humphry to that for the PCL within the same knee were 12.0% +/- 7.7% and 11.9% +/- 5.7%, respectively. The structural properties of the MFL bone-ligament-meniscus complex and the mechanical properties of the MFL midsubstance were determined by uniaxial tensile testing. The average stiffness, ultimate load, and energy absorbed at failure were, respectively, 49.0 +/- 18.4 N/mm, 297.4 +/- 141.4 N and 1125.4 +/- 735.8 N/mm. The tangent modulus between 4% and 7% strain was 355.1 +/- 234.0 MPa. Our findings suggest that the MFL is a significant biomechanical structure in the knee because of its size, stiffness, and strength.

The “stiff knee,” which has been referred to as “arthrofibrosis,” “infrapatellar contracture syndrome,” “patella infera,” “ankylosis,” and various other names, is unfortunately an all too common complication of both fracture management and knee ligament surgery. The etiology of this difficult problem is as diverse as the terms used to describe it. It can be related to inadequate reduction or fixation of intraarticular fractures, prolonged traction or immobilization, infection, and ligament surgery (both intra- and extraarticular) to highlight only a few associated risk factors.

The authors conducted a study to determine if the long head of the biceps muscle and its attachment at the superior glenoid labrum play a role in stability of the shoulder in an overhead position. Their study used a dynamic cadaveric shoulder model that simulated the forces of the rotator cuff and long head of biceps muscles as the glenohumeral joint was abducted and externally rotated. Their data suggest that the long head of the biceps muscle contributes to anterior stability of the glenohumeral joint by increasing the shoulder's re sistance to torsional forces in the vulnerable abducted and externally rotated position. The biceps muscle also helps to diminish the stress placed on the inferior gle nohumeral ligament. Detachment of the superior gle noid labrum is detrimental to anterior shoulder stability as it decreases the shoulder's resistance to torsion and places a greater magnitude of strain on the inferior gle nohumeral ligament.

With the significant amount of research directed towards the anterior cruciate Hgament (ACL) over the last two decades, the functional importance of the posterior cruciate ligament (PCL) has also become evident. As is true for the ACL, PCL insufficiency can lead to progressive laxity of secondary stabilizers of the knee, resulting in localized pain, swelling, and joint instability, and long-term degenerative changes. While surgical reconstruction is often performed in active patients, a better understanding of both the anatomy and biomechanics of the PCL is required in order to ensure the proper selection of appropriate structure and material for the graft, as well as the optimal graft placement. This chapter will attempt to review, quantify, as well as compare the basic anatomical and biomechanical properties of the PCL (and its subportions) and meniscofemoral ligaments (MFLs). In considering PCL anatomy, the midsubstance cross-sectional and insertion site areas of the PCL and MFLs will be compared and contrasted with those of the ACL. The tensile properties of these tissues, i.e., the structural and mechanical properties, will then be addressed. The information reviewed should provide a better understanding of the structure-function relationship of the PCL and supply initial basic science data to assist in guiding PCL reconstruction.

Harvesting the central third of the patellar tendon for autograft anterior cruciate ligament reconstruction is thought to compromise quadriceps strength and func tional capacity. We compared objective measurements of quadriceps strength and functional capacity in ath letes after patellar tendon autograft or allograft anterior cruciate ligament reconstruction. We looked at 33 ac tive male patients (mean age, 24.3 years) who had anterior cruciate ligament reconstructions 12 to 24 months earlier using patellar tendon autograft (N = 15) or allograft (N = 18) techniques. All patients under went an intensive rehabilitation program. Quadriceps strength and power were assessed by measuring peak torque at 60 and 240 deg/sec, torque acceleration energy at 240 deg/sec, and the quadriceps index using a Cybex II isokinetic testing device. Functional capacity was evaluated based on the results of 3 specially designed functional performance tests and the hop test. Results revealed no significant difference between au tograft and allograft groups with respect to any of these parameters. These findings indicate that harvesting the central third of the patellar tendon for autograft anterior cruciate ligament reconstruction does not diminish quadriceps strength or functional capacity in highly active patients who have intensive rehabilitation. Thus, the recommendation to avoid patellar tendon autograft anterior cruciate ligament reconstruction to preserve quadriceps strength and functional capacity may be unnecessary.

We did a retrospective review and follow-up examina tion to investigate the incidence, risk factors, and out come of patients who developed loss of motion after arthroscopic anterior cruciate ligament reconstruction. Two hundred forty-four patients with a minimum fol lowup of 1 year were reviewed. Loss of motion (defined as a loss of extension of more than I0° or flexion of less than 125°) was identified in 27 patients for an overall incidence of 11.1%. Factors associated with loss of motion included acute reconstruction (less than 1 month from initial injury), male sex, and concomitant medial collateral ligament repair or posterior oblique ligament reefing or both. Twenty-one patients required surgery to regain their motion; three patients required a second procedure. Twenty-one of 27 patients with loss of motion under went a detailed followup and were compared with 24 randomly chosen controls who had a normal range of motion after anterior cruciate ligament reconstruction. At followup, patients who experienced loss of motion had a significant decrease in noninvolved to involved knee extension and flexion compared to the control patients. There was no difference between our patients and the controls regarding patellofemoral problems, anterior knee laxity, and functional strength. Sixty- seven percent of patients with loss of motion had a good or excellent result in comparison to 80% of the controls.

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.

Question: In asymptomatic patients, what is the clinical course of meniscal lesions diagnosed by magnetic resonance imaging? Design: Inception cohort study with follow-up of ≥2 years (mean, 30 mo). Setting: An orthopaedic hospital in Zurich, Switzerland. Patients: 100 patients who were referred for magnetic resonance imaging for suspected meniscal lesions in one knee and no symptoms in the other were followed. Patients were ≥18 years of age, had no pain in the asymptomatic knee before presenting for magnetic resonance imaging, had not experienced disruptions of work or sports activity because of knee problems, and had not had knee surgery. 84 patients (mean age, 44 y; 57% men) completed the study. Assessment of prognostic factors: Magnetic resonance imaging was used to assess meniscal lesions of the asymptomatic knee. 53 knees had normal menisci, 26 had horizontal or oblique partial-thickness tears, 1 had a radial tear, 2 had vertical or full-thickness tears, and 2 had tears with displaced meniscal fragments. Main outcome measure: The adapted Knee Injury and Osteoarthritis Outcome Score (KOOS), which assessed pain, stiffness, and function with use of visual analogue scales (VAS). Main results: More patients with meniscal tears than those without meniscal tears reported having some pain, stiffness, and impaired daily function; however, the mean VAS scores for these outcomes did not differ between patients with and without meniscal tears (Table). None of the initially asymptomatic knees underwent surgery during follow-up.

The objectives of this study were to determine the effects of hamstrings and quadriceps muscle loads on knee kinematics and in situ forces in the posterior cruciate ligament of the knee and to evaluate how the effects of these muscle loads change with knee flexion. Nine human cadaveric knees were studied with a robotic manipulator/universal force-moment sensor testing system. The knees were subjected to an isolated hamstrings load (40 N to both the biceps and the semimembranosus), a combined hamstrings and quadriceps load (the hamstrings load and a 200-N quadriceps load), and an isolated quadriceps load of 200 N. Each load was applied with the knee at full extension and at 30, 60, 90, and 120 degrees of flexion. Without muscle loads, in situ forces in the posterior cruciate ligament were small, ranging from 6+/-5 N at 30 degrees of flexion to 15+/-3 N at 90 degrees. Under an isolated hamstrings load, the in situ force in the posterior cruciate ligament increased significantly throughout all angles of knee flexion, from 13+/-6 N at full extension to 86+/-19 N at 90 degrees. A posterior tibial translation ranging from 1.3+/-0.6 to 2.5+/-0.5 mm was also observed from full extension to 30 degrees of flexion under the hamstrings load. With a combined hamstrings and quadriceps load, tibial translation was 2.2+/-0.7 mm posteriorly at 120 degrees of flexion ut was as high as 4.6+/-1.7 mm anteriorly at 30 degrees. The in situ force in the posterior cruciate ligament decreased significantly under this loading condition compared with under an isolated hamstrings load, ranging from 6+/-7 to 58+/-13 N from 30 to 120 degrees of flexion. With an isolated quadriceps load of 200 N, the in situ forces in the posterior cruciate ligament ranged from 4+/-3 N at 60 degrees of flexion to 34+/-12 N at 120 degrees. Our findings support the notion that, compared with an isolated hamstrings load, combined hamstrings and quadriceps loads significantly reduce the in situ force in the posterior cruciate ligament. These data are in direct contrast to those for the anterior cruciate ligament. Furthermore, we have demonstrated that the effects of muscle loads depend significantly on the angle of knee flexion.

Impingement syndrome is an ill-defined term for a variety of disorders of the shoulder that manifest as anterior shoulder pain, especially during overhead activities. These disorders each have a common pathologic course that includes rotator cuff tendinitis (RCT), and, if untreated, may proceed to cuff rupture. RCT has at least two distinct etiologies. Primary impingement of the supraspinatus tendon on the coracoacromial arch is responsible in the majority of nonathletic cases. Overhead movements in sports are prone to developing secondary mechanical impingement because of an instability pattern that is common in this population. Information from this review and clinical practice permits differentiation of the two distinct etiologies of RCT which is important in treatment planning. Much work still needs to be done in defining the microscopic pathology of RCT.