Stabilization of chronic proximal tibiofibular joint instability with a semitendinosus graft.

Although chronic proximal tibiofibular joint instability is a rare condition, it is associated with marked functional impairment. Various surgical options have been reported in literature, all associated with several problems and limitations. We describe a new technique of reconstruction of the proximal tibiofibular joint using the semitendinosus tendon. The key steps of the procedure are the preparation of a proximally released semitendinosus tendon, and its guidance through two transtibial tunnels and one transfibular tunnel. The semitendinosus tendon acts as a soft tissue sling and does not interfere with mobility at the proximal or distal tibiofibular joints as noted after fibular head resection or arthrodesis of the proximal tibiofibular joint. Further advantages are the easy accessibility of the semitendinosus graft and the small surgical scar with better cosmetic results as compared to ligamentous reconstructive procedures using a split biceps femoris tendon or a strip of the iliotibial band.

Distribution of posterior tibial displacement in knees with posterior cruciate ligament tears.

BACKGROUND: While stress radiography has been used to objectively determine the limits of posterior tibial displacement in knees with posterior cruciate ligament tears, the magnitude and distribution of posterior tibial translation has not been defined in a large population of patients with this injury. METHODS: A retrospective diagnostic study of 1041 consecutive patients with posterior cruciate ligament tears was done. Posterior tibial displacement values that were obtained with use of instrumented stress radiography with the knee held in 90 degrees of flexion in the Telos device were evaluated and compared with the values from relevant cadaveric dissection studies. RESULTS: The mean amount of posterior tibial displacement on stress radiographs was -11.58 +/- 4.31 mm (range, -5 to -30 mm). There was a displacement peak in the range of -9 to -12 mm, with 37.9% of patients exhibiting posterior laxity within this range. Traffic-related injuries were associated with significantly greater displacement values than were sports-related injuries (p < 0.001). Grade-I or II instability (12 mm of posterior tibial displacement) occurred in association with 68.7% of the sports-related injuries, compared with 54.1% of the traffic-related injuries (p < 0.001). The mean amount of posterior tibial displacement on the intact side was -1.31 +/- 1.85 mm (range, -6 to 4 mm). CONCLUSIONS: Instrumented stress radiography is a useful testing method for objectively determining the amount of posterior tibial displacement of the knee in adults with a posterior cruciate ligament injury. Absolute posterior tibial displacement in excess of 8 mm is indicative of complete insufficiency of the posterior cruciate ligament. With tibial displacement exceeding 12 mm, additional injury of secondary restraining structures should be considered. We recommend the use of stress radiography to grade and classify posterior knee laxity.

Titanium serum levels may remain elevated despite hip revision surgery for wear-through of an acetabular component.

A 62-year-old female patient showed radiographic signs of severe linear wear of the acetabular component six years after cementless total hip arthroplasty. This suggested wear-through of the acetabular liner with secondary wear of the titanium shell. At revision surgery wear-through of both the inlay and the acetabular shell were confirmed. Despite meticulous debridement serum titanium levels remained elevated for more than 12 months. Wear-through of a polyethylene acetabular liner with secondary wear of the titanium shell can lead to increased titanium serum levels. Titanium serum levels can remain highly elevated despite revision surgery.

Reliability of stress radiography for evaluation of posterior knee laxity.

BACKGROUND: Although stress radiography has been recommended for quantifying posterior tibial displacement in knees with posterior cruciate ligament insufficiency, the intratester reliability and intertester reliability of this measurement method have not been evaluated. HYPOTHESIS: Stress radiography is a reproducible measurement method in the assessment of posterior knee laxity in patients with posterior cruciate ligament lesions. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Stress radiographs of 787 patients with suspected posterior cruciate ligament lesions taken using the Telos device were evaluated independently by 3 testers: 2 of the testers were clinically experienced in the evaluation of stress radiographs, and 1 tester was a novice tester. Change in mean, standard error of measurement with calculated confidence intervals, and intra-class correlation coefficients were determined to assess intratester and intertester reliability. RESULTS: There was no significant intratester change in mean. Intratester standard error of measurement was 1.03 mm; 95% confidence intervals were+/-2.02 mm for a single measurement and+/-2.86 mm for a change in measurement. The intratester intra-class correlation coefficient was 0.95. Intertester reliability revealed a significant change in mean between the experienced testers and the novice tester (P<.001). There was no substantial difference for the standard error of measurement of each tester. The mean intertester standard error of measurement was 1.41 mm; 95% confidence intervals were+/-2.77 mm for a single measurement and+/-3.91 mm for a change in measurement. The intertester intraclass correlation coefficient was 0.91. CONCLUSION: Stress radiography was found to be a measurement method with a useful reliability for evaluation of posterior laxity in patients with posterior cruciate ligament lesions. The reproducibility of stress radiography may be influenced by multiple variables, and standardized methods are needed to minimize measurement error.

Arthroscopic evaluation of articular cartilage lesions in posterior-cruciate-ligament-deficient knees.

PURPOSE: The goal of this study was to gain more information on the likelihood of developing cartilage lesions in posterior cruciate ligament (PCL)-deficient knees. TYPE OF STUDY: Retrospective clinical study. METHODS: Standardized arthroscopy records of 181 patients with a nonsurgically treated acute or chronic PCL injury were analyzed with respect to cartilage degeneration. Subgroups with different duration of PCL insufficiency, the influence of isolated PCL or combined PCL/posterolateral instability, and the grade of posterior laxity was analyzed. RESULTS: PCL insufficiency significantly increased the risk of developing medial femoral condyle and patellar cartilage degeneration over time. Of patients whose PCL deficiency was present for more than 5 years, 77.8% showed degenerative cartilage lesions of the medial femoral condyle and 46.7% showed cartilage degeneration of the patella. After 1 year of PCL insufficiency, the number of medial femoral cartilage lesions increased threefold (13.6% v 39.1%). With the presence of combined PCL/posterolateral insufficiency the amount of medial femoral degeneration was significantly increased (36.6% v 60.6%). CONCLUSIONS: We found that PCL insufficiency is not a benign injury with respect to the development of degenerative articular cartilage lesions. The early and continuous increase in cartilage degeneration at the medial femoral condyle and the patella should be considered when discussing operative versus conservative treatment for a PCL-deficient knee. The rapid development of medial arthritis should also be considered during decision making, particularly in patients with combined PCL/posterolateral instability or those who underwent previous partial medial menisectomy.

Fixed posterior subluxation in posterior cruciate ligament-deficient knees: diagnosis and treatment of a new clinical sign.

Among 248 patients seen for posterior cruciate ligament insufficiency, 109 (44%) had fixed posterior subluxation of the tibia, defined as a condition in which posterior sag could not be reduced to a neutral position, as evidenced by posterior tibial displacement of 3 mm or more on anterior stress radiographs at 200 N. The mean fixed posterior displacement was 6.23 mm (range, 3 to 20). The fixed posterior subluxation was divided into three grades: I, 3 to 5 mm (57.8%); II, 6 to 10 mm (33.9%); and III, more than 10 mm (8.3%). Comparison of the 109 study patients with the 139 control patients revealed a history of a failed posterior cruciate ligament operation or of a patellar tendon harvest, male sex, and a long history of posterior cruciate ligament insufficiency as significant risk factors for the development of a fixed posterior subluxation. After patients were treated with a posterior tibial support brace, the fixed posterior subluxation could be reduced to a mean of 2.58 +/- 5.22 mm within an average treatment period of 180 days. Fixed posterior subluxation can be detected in patients with posterior cruciate ligament deficiency by anterior and posterior stress radiographs and should be addressed before posterior cruciate ligament reconstruction to prevent early overloading of the graft.