Masanori Tsubosaka

Comparison of Intraoperative Soft Tissue Balance Between Cruciate-Retaining and Posterior-Stabilized Total Knee Arthroplasty Performed by a Newly Developed Medial Preserving Gap Technique

BACKGROUND Medial stability of the knee is considered to be associated with good clinical results after total knee arthroplasty (TKA). This study aimed to compare intraoperative soft tissue balance between cruciate-retaining (CR) and posterior-stabilized (PS) TKA performed by a newly developed medial preserving gap technique, which aimed at preserving medial stability throughout the range of motion. METHODS Seventy CR-TKAs and 70 PS-TKAs were performed in patients with varus type osteoarthritis with the novel technique guided by tensor measurements. Final intraoperative soft tissue balance with femoral trial component in place and patellofemoral joint reduced, including the joint component gap and varus/valgus ligament balance (varus angle), with the knee at 0° (full extension), 10° (extension), 30°, 45°, 60°, 90° (flexion), 120°, and 135° (deep flexion), was measured with Offset Repo-Tensor under 40 lbs of joint distraction force. The medial compartment gap (MCG), lateral compartment gap, and medial joint looseness (MCG-polyethylene insert thickness) at each flexion angle were calculated from the measured joint component gap and varus ligament balance, and compared between CR-TKA and PS-TKA. RESULTS The MCGs from extension to deep flexion of the knee showed no significant differences between CR-TKA and PS-TKA. The lateral compartment gaps in PS-TKA from 30° to 60° of knee flexion was significantly larger than those in CR-TKA (P < .05). Medial joint looseness showed no significant differences between CR-TKA and PS-TKA which is consistent within 1 mm from extension to flexion of the knee. CONCLUSION PS-TKA similarly achieved medial stability comparable to CR-TKA using the medial preserving gap technique.

Pseudoaneurysm of the articular branch of the descending genicular artery following double-bundle anterior cruciate ligament reconstruction

Abstract This report describes a case of a pseudoaneurysm of the articular branch of the descending genicular artery following double-bundle anterior cruciate ligament (ACL) reconstruction. An 18-year-old male received double-bundle ACL reconstruction. During ACL reconstruction, a far anteromedial portal was created for femoral tunnel drilling. The patient presented with pulsatile swelling on the medial side of the knee on the second post-operative day. The pseudoaneurysm was diagnosed using contrast computed tomography and Doppler ultrasonography and was subsequently treated by embolization with a microcatheter. Although a vascular injury is a very rare complication of knee arthroscopy, it should be considered a possibility in patients who undergo such procedures.Level of evidenceV.

Effects of Suture and Tourniquet on Intraoperative Kinematics in Navigated Total Knee Arthroplasty

BACKGROUND To investigate the effects of suture (soft tissue closure) and air tourniquet use on intraoperative kinematics in navigated total knee arthroplasty. METHODS The study included 20 patients with varus-type knee osteoarthritis who underwent primary posterior-stabilized total knee arthroplasty using computed tomography (CT)-based navigation. Intraoperative tibiofemoral kinematics from maximum extension to maximum flexion were measured using the computed tomography-based navigation. The measurements were performed 3 times as follows: measurement 1: before suture (tourniquet on), measurement 2: after suture (tourniquet on), and measurement 3: after tourniquet removal. Details of kinematics including knee joint gap, tibiofemoral rotational angles, and anteroposterior (AP) distance between the femur and tibia were compared among the 3 measurements and statistically evaluated. RESULTS On the medial side, there was no significant difference among the 3 measurements in the extension gap, but measurement 1 showed a significantly larger flexion gap compared with the other 2 measurements. On the lateral side, there was no significant difference between the extension and flexion gaps in all measurements. The anteroposterior distance in measurement 1 showed that the femur was positioned significantly more anterior to the tibia at 10° and 20° of flexion compared with the other 2 measurements after suture. There was no significant difference among the 3 measurements in the tibiofemoral rotation angles. CONCLUSION These results found that the effect of suture and tourniquet was minimal, and that intraoperative kinematics can effectively evaluate postoperative passive kinematic conditions.

Two cases of late medial instability of the knee due to hip disease after total knee arthroplasty

Highlights • There are few specific reports of late medial instability after TKA.• We described two cases of late medial instability of the knee due to hip disease after TKA, which required revision TKA.• Both cases required revision TKA with constrained knee prostheses due to the severe medial instability.• The late medial instability in current study was partially due to the same mechanism underlying the long-leg arthropathy and coxitis knee.• Constrained prostheses were applied for both patients, providing moderately good results.