Press-fit fixation using autologous bone in the tibial canal causes less enlargement of bone tunnel diameter in ACL reconstruction--a CT scan analysis three months postoperatively.

BACKGROUND: Bone tunnel enlargement is a phenomenon present in all anterior cruciate ligament (ACL)- reconstruction techniques. It was hypothesized that press-fit fixation using a free autograft bone plug reduces the overall tunnel size in the tibial tunnel. METHODS: In a prospective cohort study twelve patients who underwent primary ACL reconstruction using an autologous quadriceps tendon graft and adding a free bone block for press-fit fixation (PF) in the tibial tunnel were matched to twelve patients who underwent ACL reconstruction with a hamstring graft and interference screw fixation (IF). The diameters of the bone tunnels were analysed by a multiplanar reconstruction technique (MPR) in a CT scan three months postoperatively. Manual and instrumental laxity (Lachman test, Pivot-shift test, Rolimeter) and functional outcome scores (International Knee Documentation Committee sore, Tegner activity level) were measured after one year follow up. RESULTS: In the PF group the mean bone tunnel diameter at the level of the joint entrance was not significantly enlarged. One and two centimeter distal to the bone tunnel diameter was reduced by 15% (p = .001). In the IF group the bone tunnel at the level of the joint entrance was enlarged by 14% (p = .001). One and two centimeter distal to the joint line the IF group showed a widening of the bone tunnel by 21% (p < .001) One and two centimeter below the joint line the bone tunnel was smaller in the PF group when compared to the IF group (p < .001). No significant difference for laxity test and functional outcome scores could be shown. CONCLUSION: This study demonstrates that press-fit fixation with free autologous bone plugs in the tibial tunnel results in significantly smaller diameter of the tibial tunnel compared to interference screw fixation.

Rolimeter measurements are suitable as substitutes to stress radiographs in the evaluation of posterior knee laxity.

PURPOSE: The quantification of posterior knee laxity is crucial in the evaluation of injuries to the posterior cruciate ligament (PCL) as it has important implications to the treatment for these injuries. The objective of this study was to compare the test results of stress radiography and instrumented drawer testing (Rolimeter) for the assessment of posterior knee laxity in patients with PCL injury. METHODS: In 45 patients with an injury to the PCL, lateral radiographs of both knees were obtained under anterior and posterior tibial load (150 N) using a standardized approach. Patients with injury of the ACL to either knee were excluded from the study. During the same clinic visit, an instrumented measurement of anterior-posterior knee laxity was performed at 90° of knee flexion by an experienced examiner using the Rolimeter device. The mean side-to-side differences (SSD) of both (radiographic and instrumented) measurements were compared to each other, and the correlation was calculated using the Pearson coefficient. RESULTS: The SSD (affected/healthy side) of posterior translation determined from the radiographs was 8.2 ± 3.2 mm, and the SSD of the instrumented measurement testing was 7.6 ± 3.2 mm. The mean difference between radiographic and Rolimeter test results was 1.8 ± 1.5 mm. The Pearson's correlation coefficient revealed a good correlation between both measurements of 0.74. CONCLUSIONS: It may be suggested by the results of this study that under the absence of an ACL injury and a fixed posterior drawer sign, the Rolimeter is a suitable tool to assess the posterior laxity of the knee in the clinical setting. Its advantages are the absence of radiation to the patient, its availability, and the low cost. Therefore, the Rolimeter device may serve as a valuable alternative to stress radiography in the evaluation of PCL-injured patients. LEVEL OF EVIDENCE: II.

Excellent results of lesser tuberosity transfer in acute locked posterior shoulder dislocation.

PURPOSE: The aim of the present study was to evaluate the clinical and radiological results of lesser tuberosity transfer in acute locked posterior shoulder dislocation with a humeral head defect between 25 and 45 %. METHODS: Clinical and radiological results of seven patients with locked posterior shoulder dislocation with a humeral head defect between 25 and 45 % which were managed with a modification of the McLaughlin procedure within 14 days after injury were evaluated retrospectively after a mean follow-up of 41 months. RESULTS: All shoulders remained stable. The results were good in one and excellent in six patients with a median absolute Constant score of 92 (range 80-98). Mean active pain-free abduction was 171.4° (SD 6.4), mean flexion was 175.7° (SD 4.9), and mean external rotation was 54.3° (SD 17.6). Internal rotation was restricted in all patients. There were no radiological signs of osteoarthritis. CONCLUSIONS: Lesser tuberosity transfer shows excellent clinical and radiographic mid-term results in acute cases of locked posterior shoulder dislocation with a reverse Hill-Sachs lesion between 25 and 45 %.