Aims

Although the short stem concept in hip arthroplasty procedure shows acceptable clinical performance, we sometimes get unexplainable radiological findings. The aim of this retrospective study was to evaluate changes of radiological findings up to three years postoperatively, and to assess any potential contributing factors on such radiological change in a Japanese population.

Background

Polymethylmethacrylate (PMMA) has been used for total knee arthroplasty (TKA) as a method of fixation; however, its durability has been questionable for the long-term use because of the loosening after the cement deterioration, its vulnerability toward infectious resistance, and a smaller amount of healthy bone left for the knee revision surgery. Especially, a decrease of bone density on the proximal tibia has been believed to be triggered as a result of stress shielding. When compared with a cemented TKA, a cementless TKA reduces the amount of bone loss after surgery. In 1999, the Trabecular Metal (TM), with its main composition being the porous tantalum metal, became available as a choice of the porous cementless knee joint prosthesis. The characteristics of porous tantalum metal are its great affinity to the bone as well as its similarity to cancellous bone. The porous tantalum metal starts to bond with osteoblasts, and fills up 80% of porous structure in one year; therefore, it has been characterized by its higher initial fixation strength. However, it is questionable if strong fixation strength due to bone ingrowth between the tibial tray mainly made up with the porous tantalum metal and a cancellous bone will continually be kept. Bobyn, JD, Dunbar et al. have acknowledged the existence of bone ingrowth based on the radiographic evaluation; however, their data had not been quantified in their report. In this study, the bone ingrowth density have periodically quantified using 3D bone morphometric software (TRI/3D-BON64.RATOC) after taking CT of the knee joint prosthesis.

A 51 years old female who experienced difficulty in gait ambulation due to secondary osteoarthritis of knee showed knee instability caused by paralysis associated with poliomyelitis and scoliosis. At the first medical examination, right knee range of motion was 0° to 90°, and spino malleolar distance (SMD) showed 72cm for the right leg, 78cm for the left leg, and the bilateral comparison of SMD indicated the leg length discrepancy of 6cm. The patient has a history of surgeries with an anterior – posterior instrument for the treatment of scoliosis, and with Langenskiöld method for the paralyzed right knee at the age of seventeen. The patient also experienced varus degeneration at the age of twenty seven, which was surgically treated with high tibial osteotomy. In this case, a reoperation of her right knee was performed due to the reoccurrence of the knee pain. Preoperative planning was performed using Patient-matched instrument (Signature; Biomet) which was created based on computed tomography data. Each part of osteotomy followed the resection guide by Signature, and a total knee arthroplasty was carried out using the Rotating Hinge Knee System (Zimmer, warsaw. Inc). Two week after the operation, the patient showed the ability to walk without any assistance, and has been in a good condition.

Total Knee Replacement (TKR) has been proven to be an effective procedure not only to eliminate pain but also to achieve better knee function. Recent rehabilitation is basically focused on achieving better ROM and muscle strength. However, improvements of balancing or walking ability in detail have not been sufficiently elucidated yet.

Patients who have undergone Total Knee Replacement (TKR) improve their knee functions with time dependent recovery. However, the speed and degree of recovery widely varies from person to person. Practitioners generally find that postoperative satisfaction after TKR is closely related to the degree of preoperative severity in deformity. We focused on preoperative FTA to determine how the degree of deformity affects postoperative improvements after TKR.

Total Knee Replacement (TKR) has been proven to be an effective procedure not only to eliminate pain but also to achieve better knee function. However, details improvements of balancing or walking ability have not been sufficiently elucidated yet.

The purpose of this study was to investigate the effect of knee flexion contracture on trunk kinematics.

Ten healthy old women, averaged sixty-two years, participated in this study. Subjects were tested at our laboratory with use of gait analysis system which consisted of eight retro-reflective markers (placed at bilateral acromion, anterior and posterior superior iliac spine, and iliaccrest), and five cameras. Unilateral (only right side) knee flexion contractures of zero, fifteen, and thirty degrees were simulated with a hard brace. All subjects performed walking trials at their preferred speed with or without simulation. First, level walking was measured without simulation, and then, with simulation at zero, fifteen and thirty degrees of flexion in order. Walking trials without brace was used as control. We evaluated walking velocity (m/s) and trunk kinematics (degrees). In the coronal plane, shoulder-pelvis bending angle was defined as the angle between shoulder girdle line and pelvic line. In the sagittal plane, anterior inclination of the trunk was defined by the slope linked right acromion and iliac crest, and anterior inclination of the pelvis was defined by the slope linked right superior anterior iliac spine and right superior posterior iliac spine. Shoulder-pelvis rotation angle was defined as the angle between shoulder girdle line and pelvic line in the axial plane. Maximum values were calculated.

Walking velocity was significantly decreased at thirty degrees contracture (1.19 at controls, 0.98 at thirty degrees contracture). In the coronal plane, trunk significantly tilted leftward rather (4.5) than rightward (1.8) at thirty degrees contracture. In the sagittal plane, trunk anterior inclination significantly increased at thirty degrees contracture (0.1 at controls, 3.1 at thirty degrees contracture). However, pelvic anterior inclination was similar. In the axial plane, trunk significantly rotated rightward (6.7) rather than leftward (4.3) at thirty degrees contracture.

Knee flexion contracture significantly influences physiological trunk kinematics in each plane. In particular, lateral bending to the contracture side was restricted, and this fact indicated that the lumbar spine may bend convexly to knee contracture side. These facts may result in Knee-Spine Syndrome.

Purpose: The purpose of this study was to investigate the relationship between knee flexion contracture and spinal alignment.

Methods: Ten healthy women (mean age 62) participated in this study. Subjects were examined with posture analysis system, using twelve retro-reflective markers (placed at bilateral acromion, bilateral anterior and posterior superior iliac spine, iliaccrest, greater trochanter, lateral knee joint, lateral malleolus, lateral calcaneus, and fifth metatarsal head), five cameras and a force plate. Unilateral (only right side) knee flexion contractures were simulated by using a hard brace at 0, 15 and 30 degrees. First, relaxed standing was measured without simulation, and then the same measurement was performed with each simulation. The posture without brace was used as control. The shoulder tilting angle was defined by the height difference in right and left acromions. The pelvic tilting angle was defined by the height difference in right and left superior posterior iliac spines. The anterior-bent of the trunk was defined by the slope linked right acromion and right iliac crest. The posterior-bent of the pelvis was defined by the slope linked right superior anterior iliac spine and right superior posterior iliac spine. Knee resultant force (% body weight) was calculated by using inverse dynamics technique.

Results: When contracture angle increased, the trunk was significantly tilted leftward (1.4 degrees at 30 degrees contracture), and the pelvis was significantly tilted rightward (1.8 degrees at 30 degrees contracture). In anterior-bent of the trunk, no significant difference was detected. The posterior-bent of the pelvis was significantly increased (1.5 degrees at 30 degrees contracture). The severer the right knee contracture, the smaller the right knee resultant force (41.5 at controls, 28.7 at 30 degrees contracture) and the larger the left knee resultant force (40.2 at controls, 59.9 at 30 degrees contracture).

Conclusions: This study showed the influence of knee flexion contracture not only in the sagittal plane, as the previous study reported, but also in the coronal plane. Severe unilateral knee flexion contracture can cause the lumbar spine bent convexly to the contracture side. This may result in Knee-Spine Syndrome.

The outcomes of various operative methods for osteochondritis dissecans of the femoral condyles were reviewed, and choice of these operative methods were discussed.

Twenty-four cases (19 males and 5 females) which underwent operative treatments were reviewed. The operative methods included drilling, repositioning and fixation of the osteochodral fragment, and bone graft or osteochondral graft. The minimum follow-up period was two years. The medial femoral condyle was involved in 17 cases, and the lateral, in seven. Lateral discoid meniscus or meniscal injury was combined in all the 7 cases in the lateral. The operative methods were decided from the condition of the cartilage. Drilling was performed in cases with no or minimal cartilage damages (10 cases). Repositioning (if required) and fixation of the fragment using absorbable pins was carried out in cases with a partial or total fragmentation (7 cases). Bone graft or osteochondral graft was performed when the original site was already degenerated (7 cases). Partial meniscectomy was added when the meniscal injury was combined.

In patients who received drilling, the lesion healed radiographically in all the cases and they complained of no or minimal symptoms. In patients who received the fragment fixation, re-union of the fragment was observed in 71% and the clinical outcomes were satisfactory in most of the cases. In patients who received bone graft or osteochondral graft, although union of the graft was observed in all the cases radiographically, 71% of the patients complained of residual pain.

From the results, drilling is sufficient if the cartilage surface is not damaged. When the fragmentation occurred already, the fragment should be repositioned and fixed to the original site before degenerated, as its clinical symptoms were much better than those with bone graft or osteochondral graft.