The purpose of this pilot study was to explore the potential of an autogenous tendon graft to substitute for an absent human knee joint meniscus. Based on the results of animal studies and human reports, it was hypothesized that autogenous tendon tissue would substitute for human knee joint meniscus: maintain mechanical integrity, convert to fibrocartilage, preserve the joint compartment, and provide symptomatic relief for the patient. Five patients, 2 men and 3 women, average age 41 years, had surgical absence of the lateral meniscus, genu valgum, and severe degenerative arthritis of the lateral compartment, but a stable knee. All patients were offered alternative treatments: do nothing, medication, arthroscopic debridement, osteotomy, and knee replacement. The operations were performed by arthroscopy. An accompanying arthroscopic debridement procedure was performed in the same compartment. In 4 cases, the donor graft was the semitendinosus tendon. In 1, the patellar tendon was used because the semitendinosus had been previously used in an anterior cruciate ligament reconstruction. Four of the 5 patients had a second-look arthroscopy and biopsy between 9 and 24 months. There was partial physical integrity to the tendon graft. The tendon graft did not completely convert to fibrocartilage. The joint surface was not preserved. Only 1 patient had minimal clinical improvement; the others were not improved. No patient was made worse. One patient had a total knee replacement 1 year later. Another had a knee fusion after 4 years. All other patients are considering future reconstructive surgery. The autogenous tendon graft as used in this pilot study was not successful as a substitute for an absent meniscus. The hypothesis was not realized. The observations from this pilot study should be helpful in future study protocol design.

The effect of a bone compaction technique versus conventional drilling on the early fixation of porous-coated implants was examined in a canine model. Compaction dilation resulted in a significant increase in implant fixation stiffness (P <.01) and ultimate fixation strength (P <.01) at 0 and 3 weeks. Fixation stiffness remained significantly increased at 6 weeks (P <.01); however, the ultimate fixation strength was not statistically significant between the 2 techniques (P >.05). There was no significant difference in either fixation value at 9 weeks (P >.05). Histological examination of the bone-implant interface demonstrated an increase in the density of cancellous bone immediately adjacent to the implants placed in the compaction dilated holes. The results of this study suggest that the compaction method of host bone preparation may optimize the initial stability of the implant interface of porous-coated prostheses.

Autogenous cancellous bone was evaluated as a material to repair large osteochondral defects in 20 adult mongrel dogs. In one knee, the bone graft was used to fill an osteochondral cylindrical defect (10 mm diameter x 10 mm deep) created in the femoral trochlea. A similar lesion was created in the contralateral knee but was left untreated for spontaneous healing. Four animals were killed at each of five periods (2, 4, 8, 12, and 24 weeks), and the healing response of the defects was evaluated by gross anatomic inspection, plain film radiography, high-resolution radiography, and histology. The results of this study suggest that the use of a cancellous bone graft accelerates the repair of large osteochondral defects and produces more uniform filling of the defect than the ungrafted control. The reparative surface of the grafted lesions also differed from that of controls, having uniform coverage with histochemical-positive staining fibrocartilage at 8 weeks, a finding not observed in any control defect through the length of this study, 24 weeks.

Two hundred ten adults, 100 women and 110 men, were recruited on the condition of always having asymptomatic knee joints. These recruits were initially solicited by newspaper advertisement. The women were recruited in 3 weeks, but additional efforts and 3 months were necessary to assemble the group of men. The volunteers underwent a uniform comprehensive medical history questionnaire, physical examination, and plain film radiographs. The data collected were subjected to computerization and statistical analysis. Although these subjects were always asymptomatic, only 4.5% of 200 women's knees and 21% of 220 men's knees had no "positive" physical findings. The findings of hypermobile patella, patellar crepitus, and lateral patellar position on Merchant x-ray view were common. Findings not present or infrequent in these asymptomatic subjects and potentially pathological were patellar J-sign, decreased range of motion, asymmetrical ligamentous laxity, McMurray's sign, compartmental crepitus, and severe degenerative arthritis or loose bodies on radiograph. The findings in women were different from those observed in men. This gender-specific information should be helpful in patient management but also useful and timely for establishing practice guidelines, treatment algorithms, and outcome study instruments.

The purpose of this study was to establish the incidence of the anatomic structure, the popliteal bursa, in patients undergoing arthroscopy and to determine the relationship to associated clinical and pathological factors. Diagnostic arthroscopy was used to identify the presence of the popliteal bursa in 187 consecutive patients (195 knees). Thirty-seven percent of knees had a popliteal bursa identified by the communication with the posterior medial compartment. The cause of the popliteal bursa was not established by this study. This study refuted the causes proposed by others. The existing erroneous conclusions concerning the cause of the popliteal bursa were probably attributable to the failure to recognize the common continuity of the bursa and the knee joint. When the popliteal bursa is present (37%), it becomes symptomatic by responding to the intraarticular disease because of its continuity with the knee joint.

The purpose of this pilot study was to determine if an accurate diagnosis could be made concerning the knee joint using only the patients' medical history information. Only women were chosen for this study because of existing unpublished data on a cohort of 100 women with normal knees to act as a control (group I). From the 2,266 knee surgical procedures in the database of one surgeon, two other groups were selected. Group II was those women with only a torn medial meniscus. Group III were those women with only a torn anterior cruciate ligament (ACL). The medical history data of one half of the database were statistically analyzed to determine the questions that were the best predictors of each group. The medical history questions discovered to be best predictors were different from what might be expected from an individual surgeon's experience, expert opinion, or a medical consensus opinion panel, but the predictors did have a foundation in fact and are substantiated by statistical analyses. Using these predictors, a validation was performed on the other half of the database. When the top 142 predicting questions were used, the diagnostic accuracy was 98%; 98 of 100 of the "normal" group, 57 of 59 cases classified as having a torn meniscus, whereas 128 of 129 cases classified as having a torn ACL were correctly identified. When the only the 30 strongest predictors were used, the diagnostic accuracy was 85%: 100 of 100 cases were correctly classified as normal, 45 of 59 cases were correctly classified as having a torn meniscus, and 101 of 129 cases were correctly classified as having a torn ACL. This study demonstrated that statistical methods applied to medical historical data can make a differential clinical diagnosis of an unknown knee joint problem with high degree of accuracy and with statistical significance. In the future, computerized medical diagnostic instruments can be constructed using these statistical methods.