All-arthroscopic glenoid reconstruction by iliac crest bone graft transfer does not affect structural integrity and 3-dimensional volume of the subscapularis muscle.

AIM: The subscapularis muscle is an important active stabilizer of the glenohumeral joint. For this radiological study, we investigated if its radiological integrity is affected after arthroscopic glenoid reconstruction. In the technique used, an autologous iliac crest graft is transported through the rotator interval, and the graft is fixed via an antero-inferior portal with compression screws. METHODS: 3 women and 6 men (mean age 31 ± 9 years, min 21, max 46 years) who had a preoperative glenoid deficit of 23% ± 6% (min 13%, max 29%) were included. In a follow-up after an interval of 34 months (min 19, max 50), MRI scans were performed on both shoulders. With ITK-SNAP, a 3D reconstruction software, the volume of the subscapularis muscle in the injured and contralateral shoulder was measured. In addition, signal intensity ratios (PSI) (infraspinatus muscle / cranial subscapularis muscle and infraspinatus muscle / caudal subscapularis muscle) were analyzed and the width of the cranial and caudal portions as well as the length of the subscapularis muscle in the parasagittal plane were determined. RESULTS: The 3D volume showed no difference between operated and healthy shoulders (p = 0.07), neither did PSI ratios (infraspinatus muscle / cranial subscapularis muscle: p = 1.00, infraspinatus muscle / caudal subscapularis muscle: p = 1.00). In the parasagittal plane, length (p = 0.09) and cranial width (p = 0.23) did not differ. However, the width of the lower muscle was increased in injured shoulders (p = 0.02). CONCLUSION: In this cohort, no relevant volume loss could be found after arthroscopic glenoid reconstruction. However, a greater width of the lower muscle portion could be identified in the parasagittal plane as a possible indication of scarring.

Bone grafts used for arthroscopic glenoid reconstruction restore the native glenoid anatomy.

PURPOSE: Recurrent anterior instability of the glenohumeral joint is a demanding condition, especially in cases of glenoid bone loss. Various treatment options have been described, such as arthroscopic grafting techniques and the Latarjet procedure. In this study, the degree to which an arthroscopically applied iliac crest graft restores the glenoid anatomy was evalutated. METHODS: Nine patients (three women and six men) with an average age of 31 ± 9 years (21-46 years) who were treated with an arthroscopic iliac crest graft technique were included in this study. After a mean follow up of 34 ± 10 months (19-50 months) after the procedure, MRI scans of both shoulders were performed and the glenoid width, Glenoid Index (GI), Pixel Signal intensity (PSI), thickness of the tissue covering the articular aspect of the graft, inclination, version, concavity and balance stability angle were measured. RESULTS: All scans showed the cultivation of tissue on the graft, which visually resembled the cartilage of the native ipsilateral glenoid. Additionally, reshaping of the graft to repair the glenoid configuration could be observed. Glenoid width (p = 0.022) and GI (p < 0.001) increased significantly through surgery. The tissue examined on the graft showed a significant pixel intensity gap (p = 0.017) but comparable thickness (n.s.) in relation to native cartilage. The remaining parameters did not differ significantly between both shoulders. CONCLUSION: In the cohort presented, iliac crest grafts were able to restore the glenoid configuration, and the glenoid was re-shaped to its native contour. Additionally, cartilage-like scar tissue with similar thickness as healthy cartilage was formed on the articular side of the graft. These results suggest that glenoid reconstruction is not only important for prevention of recurrence, but also for restoration of the native glenoid anatomy. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Improved outcomes after anterior cruciate ligament reconstruction with quadrupled hamstring autografts and additional bone plug augmentation at five year follow-up.

PURPOSE: Hybrid fixation has been proposed to improve outcomes of anterior cruciate ligament (ACL) reconstructions. This study evaluated midterm outcomes after transfemoral graft fixation using either a conventional or a modified technique using additional bone plug augmentation (BPA) of the femoral tunnel aperture. METHODS: Seventy-one consecutive patients undergoing ACL reconstruction using a quadrupled hamstring autograft with transfemoral graft fixation and tibial interference screw fixation were included. Of these, 56 patients could be followed up 61 months (range 52-69 months) after ACL reconstruction both clinically and by magnetic resonance imaging (group A, conventional technique, n = 34; group B, modified technique, n = 22). Anteroposterior (AP) laxity measurements and International Knee Documentation Committee (IKDC), Lysholm and Tegner activity scoring were performed, while imaging included assessment of bone tunnel diameters, graft condition and graft filling at the femoral bone tunnel aperture. RESULTS: Patients with additional BPA had a significantly higher degree of graft filling at the femoral bone tunnel aperture (p = .0135) and 'healthier' grafts (p = .0495). They also tended to display less AP laxity difference in terms of mean differences and total patient numbers. Lysholm, IKDC and Tegner activity index scores and bone tunnel diameters were not significantly different. CONCLUSIONS: Additional BPA is an easy-to-perform, cheap and safe manoeuvre, which has the capacity to improve morphological and clinical outcomes at five year follow-up. However, femoral tunnel widening is unaffected by additional BPA.

High incidence of tunnel widening after anterior cruciate ligament reconstruction with transtibial femoral tunnel placement.

BACKGROUND: This study evaluated the incidence, amount, morphology and clinical significance of bone tunnel widening (TW) at a mean 5-year period after anterior cruciate ligament reconstruction (ACLR) with a transtibial drilling technique. METHODS: Fifty-nine patients undergoing primary ACLR using quadrupled hamstring autografts, biodegradable transfemoral pins for femoral-sided and 2-mm oversized interference screws for tibial-sided graft fixation were followed up at a mean 61 months postoperatively. Patients were examined clinically and by MRI. Tunnel cross-sectional areas (CSA) were related to drill diameters, which were significantly correlated with radiographic tunnel sizes. Tunnel morphologies were assessed and their positions determined using an anatomical coordinate system. RESULTS: CSA had more than doubled in all segments measured (p < 0.0001) except at the femoral notch level. Greatest CSA increases were found at the femoral graft suspension point (122 %) and at the central tibial tunnel segment (134 %). 54 (92) and 56 (95 %) patients had significant TW, i.e., CSA increase of more than 50 %, in at least one tunnel segment femorally and tibially. Four different tunnel morphologies were observed, of which the linear type was most often encountered on either side. Mean side-to-side difference in anterior-posterior laxity was 1.0 ± 1.4 mm, while Lysholm, IKDC and Tegner activity scores were 90 ± 12, 84 ± 15 and 4 (1-9); clinical outcomes were not found to be correlated with tunnel sizes and morphologies as were tunnel positions and tunnel sizes. CONCLUSIONS: This study demonstrates that considerable TW occurs in virtually all patients in the mid term after ACLR using a transtibial drilling technique with 'high' femoral tunnel positions. Yet, neither amount nor morphology or tunnel position does affect knee stability or function.

Anterior cruciate ligament reconstruction using biodegradable transfemoral fixation at 5-year follow-up: clinical and magnetic resonance imaging evaluation.

PURPOSE: Biodegradable transfemoral graft fixation devices used in anterior cruciate ligament (ACL) reconstruction have recently been reported to precociously lose structural integrity. METHODS: This study investigated outcomes after ACL reconstruction using hamstring grafts and biodegradable transfemoral fixation at 5-year follow-up. The condition of both graft and fixation device was evaluated by magnetic resonance imaging (MRI) and related to clinical outcomes. In total, 85 patients on whom index ACL reconstructive surgery by means of a quadrupled semitendinosus-gracilis graft and biodegradable transfemoral fixation was performed were included in the study. RESULTS: Fifty-nine patients could be assessed by clinical and MRI examinations at a mean follow-up of 61 months (range, 52-69 months). Completely intact pins were found in 17 patients (29%), intact pins with delicate areas of resorption in 8 patients (14%), pin deformation in 5 patients (8%), pin fracture in 22 patients (37%) and pin migration in 3 patients (5%). In 40 patients (68%), pins had undergone degradation at the graft suspension point. Hamstring graft integrity and signal intensity scores were found to be significantly higher in patients with deformed, broken or dislocated pins as compared to patients with fully or mainly intact pins. Clinically, the mean side-to-side difference in anterior-posterior-laxity was 1.1 ± 1.6 mm, while Lysholm, IKDC and Tegner scores were 89 ± 11, 84 ± 14 and 4 (1-9). No statistically significant correlation was found between pin condition and clinical outcomes. CONCLUSION: Biodegradable fixation pins lose structural integrity in a way that suggests continuous loading of the pin/graft construct, thereby questioning osseous incorporation of the graft. This situation is clinically relevant in terms of improved graft condition. LEVEL OF EVIDENCE: Retrospective case series, Level III.