Motorized arthroscopic instruments: a review.
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Arthroscopes↗
Biomedical subjects
B K Graf
Publications and source records attributed to B K Graf.
Results of knee manipulations after anterior cruciate ligament reconstructions.
We analyzed the results of knee manipulations in 42 knees that had persistent flexion or extension deficits after intraarticular ACL reconstructions. All manipulations were done under a spinal or general anesthetic and, in 10 cases, arthroscopic debridement of adhesions also was performed. The average time from reconstruction to manipulation was 7 months (range, 3 to 14 months) and the average followup was 26 months (range, 6 to 56 months). At manipulation, average flexion was increased from 95 degrees to 136 degrees and average extension from 11 degrees to 3 degrees. In no case was motion gained at the expense of joint stability and, at final followup, average flexion and extension were 127 degrees and 4 degrees, respectively. The final range of motion achieved was not affected by the time to manipulation, severity of premanipulation flexion deficit, or concomitant arthroscopic debridement of adhesions. However, knees with premanipulation extension deficits of greater than or equal to 15 degrees achieved significantly less final extension than knees with lesser premanipulation deficits. Overall, manipulations were a safe and effective method for improving both flexion and extension in 86% of the knees that had restricted motion after ACL reconstructions.
Adolescent↗
The effect of in situ freezing on rabbit patellar tendon. A histologic, biochemical, and biomechanical analysis.
Cell necrosis has been well documented as one of the many changes that occur in autogenous tendon when it is used to reconstruct the anterior cruciate ligament. The purpose of this experiment was to isolate cell necrosis as a variable and study its effect on the patellar tendon. To accomplish this, both knees of 25 New Zealand White rabbits were operated on. In one knee, a 5-mm wide band of patellar tendon was subjected to two rapid freeze-thaw cycles, while the other knee underwent sham surgery. Histologic evaluation showed a zone of necrosis at 2 and 4 weeks with cellular repopulation complete at 8 weeks. patellar tendon cross-sectional area was 0.118 cm2 at 8 weeks for the frozen specimens compared to 0.102 cm2 for the sham-operated controls. This difference was significant at the P = 0.025 level. Mechanical testing at 4 and 8 weeks revealed no significant changes in tendon length, maximum load, or stiffness. The collagen content was also unchanged at both 4 and 8 weeks.
Animals↗
"Bone bruises" on magnetic resonance imaging evaluation of anterior cruciate ligament injuries.
Magnetic resonance imaging of the knees of 98 consecutive patients with clinically diagnosed anterior cruciate ligament injuries revealed 47 patients (48%) with focal signal abnormalities consistent with the diagnosis of a "bone bruise." Seventy-one percent of the magnetic resonance images taken within 6 weeks of injury demonstrated a bone bruise, whereas no scans done longer than 6 weeks after injury showed a bruise (P < 0.0001). Also significant was the tendency for lesions to be located in the lateral compartment (P < 0.0001). In the sagittal plane, lesions were most likely to be in the middle third of the lateral femoral condyle and the posterior third of the lateral tibial plateau (P < 0.0001). In 31 patients evaluated arthroscopically, there was no correlation between the presence or location of a bone bruise and articular alterations or meniscal tears observed at surgery.
Anterior Cruciate Ligament↗
Anterior cruciate ligament reconstruction. The effect of tibial tunnel placement on range of motion.
In 111 patients who had anterior cruciate ligament reconstructions, postoperative radiographic measurements of anterior to posterior and medial to lateral location of the tibial tunnels were correlated with the final range of motion achieved. In the 25 patients with extension deficits of 10 degrees or more, placement of the tibial tunnel was more anterior (average, anterior 23% of the tibia) than in the remaining 86 patients with extension deficits of < 10 degrees (average, anterior 29% of tibia). This difference was statistically significant with P < 0.001. Logistic regression analysis revealed that the more anterior the placement of the tibial tunnel, the greater the loss of both flexion (P = 0.01) and extension (P = 0.002). In the 21 patients with full extension but flexion < 130 degrees, placement of the tibial tunnel tended to be more medial (average, medial 40% of the tibia) than in the 65 patients without flexion deficit (average, medial 45% of the tibia). We conclude that placement of the tibial tunnel in the "eccentric," anteromedial position may contribute to the development of flexion and extension deficits after anterior cruciate ligament reconstruction.
Adult↗
Anterior cruciate ligament reconstruction with patellar tendon. An ex vivo study of wear-related damage and failure at the femoral tunnel.
Patellar tendon grafts used in the reconstruction of the anterior cruciate ligament may be subjected to thousands of knee flexion-extension cycles during the early postoperative period. The purpose of this study was to model experimentally the patellar tendon graft wear-related damage and failure at the femoral tunnel during simulated knee motion of 0 degrees to 112 degrees of flexion at 1 cycle/sec. To evaluate the effects of 2 different femoral tunnel orientations, tunnel chamfering, and 3 different graft loads on graft survival, 25 calf femurs and patellar tendons were used. All 5 specimens with a "straight-line" femoral tunnel and an applied load of 5 pounds (22.3 N) survived greater than 125,000 cycles. All 5 of the 5-pound unchamfered transverse tunnel grafts failed at an average of 19,869 cycles, but chamfering transverse tunnels resulted in the survival of 4 of 5 specimens. Decreasing the load to 2 pounds (8.9 N) for transverse unchamfered tunnels increased survival to 1 of 5, and cycles to failure to 75,132. If patellar tendon grafts used to reconstruct the anterior cruciate ligament are subjected to large numbers of flexion-extension cycles, the risk of wear-related damage and early failure may be decreased by straight-line femoral tunnel orientation, by chamfering of more transverse tunnels, or by avoiding large graft preloads.
Animals↗
Treatment of osteitis pubis in athletes. Results of corticosteroid injections.
This study presents the results of treatment of osteitis pubis in 12 intercollegiate athletes. Early in this series, athletes were treated with prolonged rest, oral antiinflammatory medications, and hip-stretching exercises. Of the nine athletes treated in this manner, only one resumed symptom-free activity after 16 weeks of therapy; eight remained symptomatic and subsequently received a corticosteroid injection (1 ml 1% lidocaine, 1 ml 0.25% bupivacaine, and 4 mg dexamethasone) into the pubic symphysis. Of these eight athletes, three returned to full participation within 3 weeks of injection, four required a second injection to alleviate their symptoms, and one was unable to resume athletic activities despite two injections and an inguinal herniorrhaphy. In recent years, we have recommended an injection if treatment. Three athletes received a corticosteroid injection when their symptoms did not resolve. All three returned to full athletic competition within 2 weeks of the injection. The results of our study suggest that a more rapid return to intercollegiate athletics can be achieved through the judicious use of corticosteroid injections.
Administration, Oral↗