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Sixteen patients (13 males and three females; average age, 27 years) with large symptomatic osteochondral defects of the femoral condyle were treated with an osteochondral autograft taken from the ipsilateral lateral patellar facet. Two patients had bilateral procedures for a total of 18 knees. These patients were followed up prospectively with an average followup of 7.6 years (range, 2-14.6 years). Cincinnati knee scores showed significant changes, from an average preoperative score of 37 to an average final followup score of 85. In all of the patients, knee function was improved, and they were able to return to their normal lifestyle with minimal or no restriction. Eighty-one percent of patients have returned to a high level of functioning.

Traditional images of the distal femur place the intercondylar groove midway between the condyles. The location of the sulcus of the intercondylar groove in a large Sudanese skeletal population was verified using a custom stereotactic device. The results of this study show that the femoral sulcus is lateral to the midplane between the 2 femoral condyles. This study also shows that the configuration of the sulcus is linear and is oriented between the traditional anatomic and mechanical axes of the femur.

In the natural and prosthetic knees the position, shape, and orientation of the trochlea groove are three of the key determinants of function and dysfunction, yet the rules governing these three features remain elusive.The aim was to define the three-dimensional geometry of the femoral trochlea and its relation to the tibiofemoral joint in terms of angles and distances.Forty CT scans of femurs of healthy patients were analyzed using custom-designed imaging software. After aligning the femur using various axes, the locations and orientations of the groove and the trochlear axis were examined in relation to the conventional axes of the femur.The trochlear groove was circular and positioned laterally in relation to the mechanical, anatomic, and transcondylar axes of the femur; it was not aligned with any of these axes. We have defined the trochlear axis as a line joining the centers of two spheres fitted to the trochlear surfaces lateral and medial to the trochlear groove. When viewed after aligning the femur to this new axis, the trochlear groove appeared more linear than when other methods of orientation were used.Our study shows the importance of reliable femoral orientation when reporting the shape of the trochlear groove.

To examine the healing of surface defects in articular fractures, gaps measuring 0.5 mm wide and 2 mm deep were created in 0.5-mm coronal step-offs on the medial femoral condyles of 16 rabbits, and identical gaps without step-offs were created in another set of 13 rabbits. Evaluation of repair was done 6, 12, and 24 weeks postoperatively. Histologically, subchondral bone restoration of gaps in step-offs was complete by 24 weeks, whereas restoration was incomplete in most gap-only lesions. Bone density measured by peripheral quantitative computed tomography was normal in gaps in step-offs by 24 weeks, but values were less than in controls in the gap-only group. A moderate degree of degeneration was detected only at the high sides of step-off + gap lesions. The joint surface was restored by fibrous cartilage that showed gradually improving maturity in all defects, however, real integration with adjacent original cartilage did not occur. Immunohistologic examination showed decreasing collagen Type I and increasing Type II staining intensity in repair tissue of both types of lesions. These observations suggest that minor surface gaps and steps of articular fractures may regenerate without inducing severe early joint degeneration. However, certain repair features make the long-term outcome of these defects uncertain.

The concept of a Unispacer is not new. McKeever and Macintosh metallic hemiarthroplasties have been available for more than 50 years. Two decades ago, published reports for patients with unicompartmental OA revealed good initial results in 85% of patients. This procedure is conservative and easily revised, if necessary, to any type of arthroplasty in the future. The Unispacer can be thought of as a mobile McKeever or Macintosh metallic hemiarthroplasty. Rather than attempting fixation to the tibial plateau via a keel or a roughened undersurface, it is designed to translate freely on the tibial plateau as determined by the conforming articulation of its top side surface with the femoral condyle. This mobility makes it inappropriate for use in the lateral compartment where the femoral roll-back could cause prosthetic dislocation or soft tissue impingement or both. The eventual role of the Unispacer in arthroplasty currently is uncertain. There are no published reports of its effectiveness. Its indication should be similar to those for McKeever arthroplasty. A patient with unicompartmental OA in whom an osteotomy is contraindicated but is considered too young, heavy, or active for a metal-to-plastic arthroplasty is ideal. Less than 1% of patients with OA should be appropriate candidates. The procedure is technically demanding and sensitive, making its widespread success unlikely.

The use of steroid medication may predispose to osteonecrosis of the femoral condyle. However, there is a controversy regarding treatment of this disease, especially for lesions in advanced stages. Since 1987, the authors have treated such lesions by autologous osteoperiosteal graft obtained from the iliac bone. When limb alignment was affected by the disease, proximal tibial valgus or varus osteotomy was done concomitantly. The rationale for this method is to replace the necrotic bone and damaged cartilage by autogenous bone and periosteum, anticipating the chondrogenic potential of the latter. In this study, 10 knees in eight patients were reviewed to learn the outcome of this procedure with a mean followup of 79 months (range, 32-158 months). The grafts were incorporated successfully in nine joints, and satisfactory results were achieved in all patients. Therefore autologous iliac bone graft is a promising alternative for treatment of osteonecrosis, especially when patients are young and physically active.

This study was designed to analyze anteroposterior and rotational movement of femoral condyles during knee flexion from 15 degrees to 90 degrees using magnetic resonance imaging. After a pilot study, scans were made in 10 healthy male Japanese volunteers. When centers of the circular profiles of posterior femoral condyles were used as reference points, the medial and lateral femoral condyles displaced posteriorly 1.9 +/- 0.8 mm and 2.3 +/- 0.5 mm, respectively (mean +/- standard error). Duplicate examinations on two separate occasions revealed the accuracy of this procedure was in the range of 1 to 2 mm. These results have confirmed that femoral rollback occurs in the unloaded normal knee during flexion from 15 degrees to 90 degrees, but its magnitude is small (2 mm). The results obtained in this in vivo measurement of anteroposterior movement of the femoral condyles have relevance for total knee replacement design.

The site of lesion, spontaneous healing, onset mechanism, and magnetic resonance imaging findings of 51 knees in 38 patients with osteochondritis dissecans involving the femoral condyle in the growth stage were investigated. tercondylar site, and the remaining 1/4 were in other sites. Compared with those in the other sites, the lesions in a medial intercondylar site had a lower healing rate and required a longer time to heal. T2 weighted images of the lesions showed a progression from low signal areas to the appearance of a high signal line at the fragment to parent to bone interface, to a high signal double line at the interface and parent-bone surface, or to disappearance of the line. Magnetic resonance imaging often revealed discoid menisci or meniscal tears in patients with lesions in the lateral condyle, suggesting that endogenous forces play an important role in the onset of osteochondritis dissecans.

The history of osteonecrosis in the femoral condyle of the knee was observed in 15 knees in 14 patients, averaging 62.8 years in age (range, 23-79 years). There were nine women and five men. The average follow-up period was 4.9 years (range, one to 12 years). Spontaneous osteonecrosis was found in 11 patients and steroid-induced osteonecrosis in three. The medial femoral condyles were involved in 13 knees and the lateral femoral condyles in two. The maximum width of the lesion was measured on anteroposterior roentgenograms and an osteonecrotic lesion less than 10 mm wide was rated as small. Cases of small osteonecrotic lesions displayed no remarkable changes with respect to stages and limb alignment. The average size of the steroid-induced osteonecrotic lesions was significantly larger than that of the spontaneous type. The size of the osteonecrotic lesions at the follow-up examination was compared to that observed at the initial diagnosis in 12 knees. Eight of these lesions displayed increases in dimension of more than 18% over the initial size at diagnosis.

A cross-validation study was conducted on the estimation of femoral condyle width from height and gender. An equation was published in 1989 for estimation of femoral condyle width using in vivo measurements of femoral condyle width from radiographs. Further cross-validation evidence for this equation is reported using in vitro measurements from 27 cadavers. The data indicated a high correlation (r = 0.85) between actual and estimated femoral condyle width and an acceptable standard error of estimate (range, 4.48-4.29 mm). It was concluded that the published equation which uses height and gender to form an estimate of femoral condyle width has acceptable validity and is a useful tool in the selection process of donors for osteochondral allografts.

The Q-angle should be the angle generated by a line connecting the anteroinferior iliac spine (AIIS), the bottom of the groove of the femoral condyle, and the tibial tubercle. The Q-angle was measured by computed tomography (CT) in 43 lower limbs with recurrent patellar dislocation and 26 normal controls. The mean Q-angle was 20 degrees in the dislocated group and 13 degrees in controls, a significant difference. No significant difference was found in the Q-angle between the dislocated and control groups using the conventional method. Lower limb rotation had little effect on accuracy of the method.

By varying the parameters that determine the cryopreservation process (freezing rate, storage temperature, cryoprotective agents, storage time), various protocols have been designed for preservation of osteochondral allografts of rabbit femoral condyles. The grafts were implanted orthotopically for three months. After harvesting, the results were evaluated by optical microscopy, histochemistry, and electron microscopy (scanning and transmission). A quantitative study and statistical analysis was performed using a gradation scale of chondral degeneration. Synovial reaction was higher in the fresh allograft than in the cryopreservation groups. Glycerol yielded better results than DMSO as a cryoprotective agent. No cryopreservation protocols produced the results equal to the control groups of either fresh auto- or allografts. Optimal preservation was achieved with either the group with hypothermic storage at 4 degrees for no more than 48 hours or the group with slow freezing to -80 degrees and preparative exposure to 15% glycerol at 4 degrees for 60 minutes. No statistically significant differences were found in these two groups.

Forty-two knee arthroplasties (TKAs) of the posterior cruciate condylar design performed from 1975 until 1978 were reviewed. Follow-up evaluations averaged 11 years. There were 21 knees each of osteoarthrosis and rheumatoid arthritis. The average postoperative knee score was 85.4 points. Thirty-nine knees (92.8%) were rated good or excellent, one (2.4%) was judged fair, and two (4.8%) were considered failures

Fresh osteochondral shell allografting is conceived as an interim response to the localized loss of articular cartilage in young patients for whom there is no reasonable alternative after conservative procedures have failed. The concept is not new and has been investigated extensively in in vivo animal investigations. The functional and anatomic results of these studies, however, have been consistently unsatisfactory because of technical deficiencies and supposed immunogenic responses. The results of early clinical studies were variable, and despite more recent clinical work, the procedure has been considered at least investigational by some. The purpose of this study is to retrospectively review a series of patients treated with osteochondral allografting of the femoral condyle with particular emphasis on those done more than five years ago. No tissue-typing blood-group matching or gender distinction was made and immunosuppressant agents were not used. Size matching of the donor and recipient were essential to provide an orthotopic graft. Twelve knees were operated on more than five years ago. Of these twelve, three are not available for review. Nine knees have been observed for an average of 66 months and eight are rated good or excellent by a standardized rating scale. One knee rated poor seems to be the result of a technical deficiency. Since 1983, 37 fresh osteochondral allografts of the femoral condyle have been performed in 36 patients. Twenty-five of these have been performed in the last five years and the results to date are summarized.

Femoral condylar cartilage abnormalities were evaluated in patients treated with total knee arthroplasty, and real-time ultrasonic images were correlated with the abnormalities seen in the corresponding gross pathologic specimens. Subjective impressions of abnormalities on the images recorded on film correlated well with pathologic findings. Thickness measurements were easily made in normal images but proved difficult at sites of cartilage damage where the cartilage-bone and cartilage-soft-tissue interfaces became less clear. This study suggests that with further technologic refinement, this technique may provide a rapid and cost-effective method of assessing the integrity of femoral condylar cartilage.

An analysis of 1004 X-rays has demonstrated that the medial patella facet is significantly smaller in patients with patellofemoral instability. There is no such significant difference in the width of the whole patella. Therefore the longitudinal ridge separating the smaller medial facet from the larger lateral facet must be closer to the medial patella border. As this ridge articulates with the groove between the femoral condyles, its medial position is accounted for by the patella being more laterally positioned in patients with patellofemoral instability.

The surfaces of the knee--anomalous to most animal joints through apparent gross incongruity--would appear more congruous if the menisci bore load. A simple system is used to show how the menisci can bear load. The strong tibial fixation and structure of the menisci, and the geometry of the femoral condyles indicate that the menisci bear load throughout flexion and extension. Confirmatory experimental results show that in partially degenerate human and healthy pigs' knees the menisci bear at least 45 and 75% respectively of the total joint load. The knee joint is similar in this respect to other synovial joints.

Osteonecrosis of both lateral femoral condyles was observed in a 42-year-old black woman under treatment with oral prednisone. She was treated by arthrotomy and debridement on the right side and conservative management on the left side. Lateral compartment osteonecrosis is most frequently associated with steroid therapy, but bilateral involvement is infrequent.

Osteochondritis dissecans of the posterior femoral condyle is an uncommon condition. In many respects--the large size of the joint, involvement of the weight-bearing surface, natural history, method of treatment, and the population affected--it differs from the more usual condition found in the intercondylar region. In 14 cases (16 involved knees), representing the total number of cases found in the province of British Columbia during a five-year period, nearly every patient was a young male athlete. If the patient is treated before the age of 15 years, the condition may heal spontaneously or with a regimen of restricted activity. From this time, the lesion remains fairly stable and mildly symptom-producing, often for many years, until finally the osteochondral surface fragment breaks free into the joint. Once the fragment has separated, surgery becomes mandatory. To prevent degenerative joint changes and major disability is a challenge to the surgeon. Fragment removal, even with drilling of the base, has proved ineffectual. The fragment must be replaced and stable and exact anatomic realignment of the weight-bearing condylar surface restored. Multiple drilling perforations through the sclerotic base are required to stimulate revascularization. Because of the difficulty, and sometimes impossibility, of successfully meeting these exacting surgical requirements, the operation should be performed before the osteochondral fragment breaks free. The surgical technique is designed to restore vascularity to the ischemic bone and to maintain the normal contour of the condylar surface, without violating the articular cartilage surface.

An important component of successful osteochondral allograft surgery of the knee is securing a donor with a femoral condyle (FC) of the appropriate size. The purposes of the present investigation were to analyze the effect of femoral rotation on measurement of FC size and to determine if easily measured variables, such as manual caliper measurements, height, weight, and gender, are useful in matching donors and recipients. Three separate investigations were conducted to accomplish these purposes. The results indicated that femoral rotation has a significant negative effect on accurate sizing of the FC. Height and gender provide an acceptable prediction of femoral condyle size and can be used effectively in the donor selection process.

The osseous tunnel technique of anterior cruciate ligament (ACL) reconstruction was compared to the over-the-top (OTT) technique in vivo. A prosthesis replaced the ACL in 35 dogs by one of three methods: double osseous tunnels, OTT, or a combined method utilizing the unique Y shape of the prosthesis by placing one fork through a femoral osseous tunnel and the other fork over the top of the femoral condyle in the same stifle. Rupture occurred in all prostheses placed in double osseous tunnels and in one of 12 prostheses placed by the OTT technique. When rupture occurred in only one fork of prostheses placed in the combined method, all occurred in the tunnel-placed fork. If the results of the three groups are combined, rupture occurred in 16.7% of all OTT-placed prostheses versus 91.3% rupture of all osseous tunnel-placed prostheses. Objective assessment of the in vivo testing clearly indicates that the OTT technique is superior to the tunnel technique under the conditions of this study. The relationship between placement technique and rupture of other prostheses should also be tested in vivo.

The lateral X-ray view of the knee is more likely to yield the diagnosis of osteochondritis dissecans of the femoral condyles if the examiner is aware that most cases are located in the subarticular bone of the medial femoral condyle between two lines: The first extended anteriorly from the density of the roof of the intercondylar notch, and the second, extended distally from the posterior cortex of the distal femoral diaphysis.