The purpose of this study was to document the longterm clinical, radiographic, and magnetic resonance imaging results after open meniscal repair. Twenty-two patients, with 23 open meniscal repairs, were evaluated after a mean follow-up of 12.9 years using patient history, physical examination, KT-1000 arthrometer testing, the "Orthopaedische Arbeitsgemeinschaft Knie" knee evaluation scheme, Tegner activity score, weightbearing radiographs, and magnetic resonance imaging. Two of the 22 patients had retears and both occurred in unstable knees. Radiographs revealed no degenerative changes in 17 of the 23 compartments. Grade III and IV signal alterations were present on magnetic resonance imaging scans in more than 50% of the repaired menisci. We concluded that the longterm survival rate of repaired menisci was 91%, and that magnetic resonance imaging is unsuitable for diagnosis of the healing process of a repaired meniscus.

Clinical knee examination is imperative for the prognosis, follow-up, and scientific comparison of anterior cruciate ligament surgery results. A new device, the Rolimeter knee tester was studied in this study with respect to inter- and intratester reliability. We found no significant difference in the intratester evaluation, and data were reliable between repeated measurements and between different testers with the same examination technique. The tester's experience seems to play a role using use the Rolimeter knee tester, but even an inexperienced tester can use it and obtain data that are very close to the data obtained by an experienced tester when the same technique is used. Furthermore, it was found that the manual examination of anterior translation also provides a reliable measurement, at least in the hand of experienced testers. Further advantages are that the Rolimeter knee tester is cheap, can be sterilized, and is simple to use.

Prospectively, 119 patients were pursued clinically and by follow-up-arthroscopy for the occurrence of a "cyclops syndrome" after ACL reconstruction with a patellar tendon autograft, augmented by LAD. Twenty-one patients showed nodular formations. Ten of these (group 1) developed early clinical evidence of a "cyclops syndrome" with a mean extension deficit of 19 degrees before follow-up-arthroscopy, on average 5.9 months after the index operation. The nodular formations found and excised during débridement had a hard consistency. Histomorphological undecalcified microtome section evaluation of six specimens revealed fibrocartilagineous tissue with active bone formation in the center. The other 11 patients showed no clinical symptoms (group 2). A similar but soft nodulous scar formation was detected at follow-up-arthroscopy, on average 9.5 months after the index operation. Histomorphologically these so-called "cyclopoid" formations were only built-up fibrocartilagineous islands surrounded by granulation tissue. Neither remnants of tendon graft fibers nor old bone particles were found in specimens of either group. It can be concluded that both the hard cyclops and the soft "cyclopoid" are de novo scar formations.

No abstract

With magnetic resonance imaging (MRI) the surgeon has such an effective diagnostic tool in the diagnosis of a meniscal lesion that the times of diagnostic arthroscopy should be in the past. A total of 823 patients with clinically diagnosed meniscal lesions were divided into two groups: group A, 143 patients underwent MRI and 75 of those arthroscopy; group B, 680 patients, 201 (30%) of whom were operated after being only clinically examined. MRI was done on a Siemens Medical System Magnetom 1.5 Tesla with a 256 x 256 matrix. Spinal echo and gradient echo images were performed with slices of 2 to 4 mm thickness. All meniscal tears were graded according to Reicher and Crues, respectively. Grades III and IV were judged to be positive for a meniscal lesion. Arthroscopy was carried out under general anesthesia and the usual technique. The MRI revealed the following results: Medial meniscus: accuracy 95%, positive predictive value (PPV) 92%, negative predictive value (NPV) 95%, sensitivity 98%, and specificity 82%, lateral meniscus: accuracy 97%, PPV 92%, NPV 98%, sensitivity 94%, and specificity 98%. The overall values for MRI of the medial and lateral menisci combined were: accuracy 96%, PPV 93%, NPV 98%, sensitivity 96%, and specificity 90%. The clinical examination often failed to diagnose a meniscal lesion: accuracy 64%, PPV 59%, NPV 89%, sensitivity 96%, and specificity 33% for the medial meniscus. For the lateral meniscus the accuracy was 91%, PPV 61%, NPV 98%, sensitivity 89%, and specificity 91%. The overall values for the clinical investigation of the medial and lateral menisci combined were: accuracy 78%, PPV 60%, NPV 94%, sensitivity 93%, and specificity 62%. Investigation of all 201 patients operated from group B with MRI would have cost $160,800. The cost of 30% fewer arthroscopies would have been $562,800--in total $723,600. The operation of all 201 patients cost $804,000. Hence about $80,000 could have been saved by scanning all 201 patients and therefore reduce the rate of diagnostic arthroscopies.

Forty patients were prospectively investigated to evaluate the effects of bandaging after reconstructive surgery of the anterior cruciate ligament (ACL). For the 6 weeks of the postoperative course, the operated knee was bandaged in 20 patients (group A) and braced in the other 20 patients (group B). The isokinetic torque for extension and flexion (Cybex) and the range of motion (ROM) were investigated after 6, 12, 24 and 52 weeks postoperatively. At 24 weeks and 1 year postoperatively the stability of the knee joint (KT-1000) as well as the clinical outcome ('Orthopädische Arbeitsgemeinschaft Knie') were evaluated. No statistically significant differences between the two groups were found for the extension and flexion strengths. Free ROM was achieved significantly earlier in group A than in group B. No statistically significant differences regarding the stability of the operated knee joint nor the early outcome were found between the two groups. This study demonstrated that the renunciation of using a brace had no adverse effect on the early outcome with respect to stability and function. On the contrary, bracing seems not to be mandatory after ACL reconstruction when the central third of the patellar tendon is used.

V.

In this second part of our study, the histomorphologic changes occurring in the patellar tendon (PT) of rats after sole stress-shielding were evaluated. In seven adult albino rats, both PTs were exposed by straight skin incision and then stress-shielded on one side by a cerclage, while the contralateral PT served as the sham-operated control. One animal died after the operation and was used as a negative control. After 10 weeks of otherwise unrestricted motion, the rats were killed, and the histomorphology of all PT specimen pairs compared by light and transmission electron microscopy. Light microscopy showed mid-portion thickening and irregularity of collagen bundles in the stress-shielded tendons. Intense remodelling was demonstrated by increased cellularity and vascularity, as well as by enrichment in acidic proteoglycans. Ultrastructural evaluation and morphometry revealed a predominance of large diameter (peak between 180 and 260 nm) collagen fibrils in the sham-operated controls, while in the stress-shielded tendons the number of apparently new, small-diameter (peak between 40 and 60 nm) collagen fibrils increased (up to 77% per cross-sectional field of view). The difference in peak diameters was statistically significant (p < 0.0005). This rat model demonstrated that sole stress-shielding not only causes biomechanical alterations, but also intense tissue remodelling and significant morphological changes in the collagen fibrils in the patellar tendon, comparable to so-called 'ligamentization' in experimental and clinical patellar tendon grafts for anterior cruciate ligament reconstruction.