Daniel Levin

Hyperbaric oxygen therapy as a treatment for stage-I avascular necrosis of the femoral head.

Avascular necrosis (AVN) of the head of the femur is a potentially crippling disease which mainly affects young adults. Although treatment by exposure to hyperbaric oxygen (HBO) is reported as being beneficial, there has been no study of its use in treated compared with untreated patients. We selected 12 patients who suffered from Steinberg stage-I AVN of the head of the femur (four bilateral) whose lesions were 4 mm or more thick and/or 12.5 mm or more long on MRI. Daily HBO therapy was given for 100 days to each patient. All smaller stage-I lesions and more advanced stages of AVN were excluded. These size criteria were chosen in order to compare outcomes with an identical size of lesion in an untreated group described earlier. Overall, 81% of patients who received HBO therapy showed a return to normal on MRI as compared with 17% in the untreated group. We therefore conclude that hyperbaric oxygen is effective in the treatment of stage-I AVN of the head of the femur.

The effects of enoxaparin on the reparative processes in experimental osteonecrosis of the femoral head of the rat

The blood supply of one femoral head of 6‐month‐old rats was severed by incising the periosteum of the neck and cutting the ligamentum teres. The rats were killed on the 30th postoperative day and the femoral bones were obtained for semiquantification of the reparative processes in the necrotic heads. Fourteen rats were treated with enoxaparin and 14 untreated animals served as controls. Statistically, the amounts of necrotic bone in the epiphysis were less, the extent of remodeling of the femoral heads was milder, and the articular cartilage degeneration was slighter in the enoxaparin‐treated than untreated rats. There was no significant difference in the quantities of newly formed bone in femoral heads of treated and untreated rats. These findings are in agreement with the known effects of unfractionated and low‐molecular‐weight heparins which enhance osteoclastic bone resorption and angiogenesis and decrease osteoblastic bone formation. The former activities, operative in minimizing the structural distortion of the femoral head, oppose the crucial event in the pathogenesis of post‐osteonecrotic osteoarthritis.

Osteoarthritis-like disorder in rats with vascular deprivation-induced necrosis of the femoral head.

The reparative processes following vascular deprivation-induced necrosis of the femoral head were studied histologically in rats sacrificed 2, 7, 14, 21, 42 and 92 days postoperatively. The blood supply was severed by incision of the periosteum at the neck of the femoral head and transection of the ligamentum teres. Granulation tissue and a well-vascularized fibrous tissue originating from the joint capsule invaded the necrotic marrow spaces. With progressive resorption of the necrotic tissues and osteoneogenesis, both appositional and intramembranous, within the fibrotic intertrabecular spaces, the remodeling process led to a shift of the normal spongy architecture of the femoral head to a compacta-like one. In a few cases, osseous bridges bisected a necrotic physeal cartilage at the latest time intervals. The remodeling was associated with flattening of the femoral heads as well as with degenerative, regenerative and reparative alterations of the articular cartilage. In one of the two femoral heads obtained three months postoperatively, cystic spaces developed in the fibrous subchondral zone. Our findings are consistent with the view that ineffective attempts at restoring the prenecrotic state of the femoral head by replacing the necrotic with viable tissue triggers the collapse of the femoral head. Thickening and condensation of the subchondral bone, leading to increased stiffness of the subchondral zone, result in the osteoarthritis-like disorder. Mimicking the well-known phases of human osteonecrosis, the model readily allows for preclinical studies of therapeutic regimens.

Transphyseal osseous bridges in experimental osteonecrosis of the femoral head of the rat. Histologic study of the bony bridges connecting the epiphyseal with the metaphyseal bony trabeculae through gaps in the physeal cartilage.

In view of the lifelong persistence of the physis, the femoral head of rats may serve to model Perthes disease and slipped capital femoral epiphysis. To produce osteonecrosis, the blood supply of one femoral head of 133, 6-month-old animals was severed by circumferentially incising the periosteum of the neck and cutting the ligamentum teres. The rats were killed 7 days to 90 days postoperatively. Associated with resorption of the necrotic bone and marrow, remodeling of the epiphysis was characterized by an ingrowth of vascularized fibrous tissue, formation of new bone and some cartilage, architectural deformation and flattening of the head. In 22 of 83 rats killed 30 days or more postoperatively, gaps in the continuity of the physeal cartilage were occupied by osseous bridges, connecting newly formed epiphyseal bony trabeculae with either the preexisting or newly formed metaphyseal osseous trabeculae. This healing mode may follow ischemic death of physeal chondrocytes or be owing to another mechanism, e.g., release of mediatory substances of inflammation. These findings raise the possibility that fixation of the healing epiphysis of a childs previously necrotic femoral head to the metaphysis occurs by transphyseal osseous growth in cases in which the physis is involved in the necrotic process.

Postosteonecrotic osteoarthritis-like disorder of the femoral head of rats.

The femoral heads of 15 rats were studied histologically 3 months after the induction of ischaemic necrosis by incising the cervical periosteum and cutting the ligamentum teres. The epiphyses consisted of immature disorganized subchondral and trabecular bone. The inter-trabecular spaces contained fibrous or haematopoietic tissue. Residual necrotic bone was rare. There was marked osteoblastic and osteoclastic activity. The articular aspect of the heads showed a spectrum of changes, ranging from cartilaginous degeneration with fibrillation and loss of glycosaminoglycans to an eburnated and polished bony surface. In seven rats, transphyseal bridges connected the epiphyseal and metaphyseal bony trabeculae to each other. It is suggested that the postnecrotic reparative processes, including the resorption of the necrotic debris and its replacement by newly formed, weak bone, led to an osteoarthritis-like disorder. This healing pattern of the necrotic femoral head was reminiscent of the progressive remodelling that occurs in rings in femoral capital osteonecrosis of adult human patients and in Perthess disease of children.

Positive outcomes following gait therapy intervention for hip osteoarthritis: A longitudinal study

Footwear‐generated biomechanical manipulation of lower‐limb joints was shown to beneficially impact gait and quality of life in knee osteoarthritis patients, but has not been tested in hip osteoarthritis patients. We examined a customized gait treatment program using a biomechanical device shown in previous investigations to be capable of manipulating hip biomechanics via foot center of pressure (COP) modulation. The objective of this study was to assess the treatment program for hip osteoarthritis patients, enrolled in a 1‐year prospective investigation, by means of objective gait and spatiotemporal parameters, and subjective quality of life measures. Gait analysis and completion of questionnaires were performed at the start of the treatment (baseline), and after 3, 6, and 12 months. Outcome parameters were evaluated over time using linear mixed effects models, and association between improvement in quality of life measures and change in objective outcomes was tested using mixed effect linear regression models. Quality of life measures improved compared to baseline, accompanied by increased gait speed and cadence. Sagittal‐plane hip joint kinetics, kinematics, and spatiotemporal parameters changed throughout the study compared to baseline, in a manner suggesting improvement of gait. The most substantial improvement occurred within 3 months after treatment initiation, after which improvement approximately plateaued, but was sustained at 12 months. Speed and cadence, as well as several sagittal‐plane gait parameters, were significant predictors of improvement in quality of life. Clinical significance: Evidence suggests that a biomechanical gait therapy program improves subjective and objective outcomes measures and is a valid treatment option for hip osteoarthritis.

Urinary frequency caused by a misplaced acetabular reinforcement ring--a case report

Matta J M. Operative treatment of acetabular fractures through the ilioinguinal approach. A 10-year perspective. Clin Orthop 1994; 305: 10-9. Mayo K A. Open reduction and internal fixation of fractures of the acetabulum. Results in 163 fractures. Clin Orthop 1994; 305: 31-7. Miranda Junior F, Francisco Junior J, Burihan E. The management of venous trauma: early and late results. Int Angiol 1991; 10 (3): 146-51. Moreno C, Moore E E, Rosenberger A, Cleveland H C. Hemorrhage associated with major pelvic fracture: a multispecialty challenge. J Trauma 1986; 26 (11): 98794. Nazzal M, Bove P G, Harris J A, Bendick P J, Glover J L. Hemodynamic sequelae of combined arteriovenous injury in an experimental canine hindlimb model: venous ligation vs. repair. Ann Vasc Surg 1994; 8 (2): 166-71. Pohlemann T, Bosch U, Gansslen A, Tscherne H. The Hanover experience in management of pelvic fractures. Clin Orthop 1994; 305: 69-80. Rothenberger D A, Fischer R P, Perry J F, Jr. Major vascular injuries secondary to pelvic fractures: an unsolved clinical problem. Am J Surg 1978a; 136 (6): 660-2. Rothenberger D A, Fischer R P, Strate R G, Velasco R, Perry J F, Jr. The mortality associated with pelvic fractures. Surgery 1978b; 84 (3): 356-61. Ruesch P D, Holdener H, Ciaramitaro M, Mast J W. A prospective study of surgically-treated acetabular fractures. Clin Orthop 1994; (305): 38-46. Sharma P V, Shah P M, Vinzons A T, Pallan T M, Clauss R H, Stahl W M. Meticulously restored lumina of injured veins remain patent. Surgery 1992; 112 (5): 928-32. Woodson J, Rodriguez A A, Menzoian J O. The use of internal jugular vein as interposition graft for femoral vein reconstruction following traumatic venous injury: a useful approach in selected cases. Ann Vasc Surg 1990; 4 (5): 494-7. Yelon J A, Scalea T M. Venous injuries of the lower extremities and pelvis: repair versus ligation. J Trauma 1992; 33 (4): 532-6; discussion 536-8.