1/8. Progressive bone resorption after pathological fracture of the femoral neck in Hunter's syndrome.We report a case of Hunter's syndrome associated with a transverse fracture of the left femoral neck after minor trauma, followed by progressive resorption of the femoral head at 12 years of age and a stress fracture of the right femoral neck at 16 years of age. MRI performed at 15 years of age revealed intra-articular low intensity on T1-weighted and T2-weighted images of both hip joints. The MR finding may represent fibrous synovial thickening, which caused pressure erosion of the femoral neck, resultant pathological and/or stress fractures, and subsequent osteonecrosis with rapid absorption of the femoral head.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
2/8. In vivo acetabular contact pressures during rehabilitation, Part I: Acute phase.The authors conducted a two-part study to compare in vivo acetabular contact pressures during the acute and postacute phases of rehabilitation. This report compares in vivo acetabular contact pressures generated during selected "inpatient" rehabilitation activities and their relationship to pain, range of motion, and other clinical indicators. A pressure-instrumented Moore-type endoprosthesis was implanted in a 73-year-old woman who had sustained a femoral neck fracture. Acetabular contact pressures during the first 2 weeks after surgery were rank-ordered. Clinical data, including range of motion, manual muscle test grade, use of pain medication, and independence in gait, were collected simultaneously. Acetabular pressures did not follow the predicted rank order corresponding to the commonly prescribed temporal order of inpatient rehabilitation activities. Isometric hip extension and active hip flexion generated the highest pressures of all the studied activities, including those measured during gait activities. Isometric exercises, therefore, may not be entirely benign preparation for ambulatory activity. Clinical data did not correspond with peak pressure data, suggesting that observed responses to rehabilitation may not be dependable criteria for progressing the acute hip rehabilitation protocol. We discuss applications for rehabilitation programs based on hip contact pressure data as an initial attempt to formulate more defensible rehabilitation approaches for patients with acutely painful hips.- - - - - - - - - - ranking = 12keywords = pressure (Clic here for more details about this article) |
3/8. In vivo acetabular contact pressures during rehabilitation, Part II: Postacute phase.The authors conducted a two-part study to compare in vivo acetabular contact pressures during the acute and postacute phases of rehabilitation in a single subject with a pressure-instrumented femoral prosthesis. This report compares six common hip rehabilitation activities for resultant in vivo hip pressure magnitudes during the first 5 years after discharge from an acute care hospital. These activities were full, partial, touch-down, and non-weight-bearing ambulation and isometric hip abduction and straight-leg-raising exercises. A pressure-instrumented femoral endoprosthesis implanted in a 73-year-old woman who had sustained a femoral neck fracture provided data for the activities. The activities were rank ordered and compared over time according to peak pressure magnitude. Prescribed weight bearing and exercise type were not good predictors of hip peak pressures in this patient. Maximum pressures occurred by 1 year postdischarge for most activities, with a tendency to stabilize or decline thereafter. Resisted isometric hip abduction exercise demonstrated the most variation over time. The results suggest that hip pressures may be limited by controlling muscle force and movement velocity during postoperative hip rehabilitation activities.- - - - - - - - - - ranking = 12keywords = pressure (Clic here for more details about this article) |
4/8. Contact pressures from an instrumented hip endoprosthesis.A pressure-measuring Moore-type endoprosthesis was implanted in a seventy-three-year-old patient who had sustained a displaced fracture of the femoral neck. The measurement and telemetry of contact pressures in the hip began in the operating room, and data were acquired periodically for more than thirty-six months. Unexpectedly high localized contact pressures between the acetabular cartilage and the prosthesis were recorded. Early in the period of recovery, activities such as using a bedpan or performing isometric exercise produced pressures that were close to those recorded during normal walking. The highest pressure, eighteen megapascals, was recorded one year postoperatively, while the patient was rising from a chair. High pressures occurred in the superior and posterior aspects of the acetabulum.- - - - - - - - - - ranking = 10keywords = pressure (Clic here for more details about this article) |
5/8. Transient impotence from positioning on the fracture table.A case of transient impotence caused by pressure from the perineal post of the fracture table is reported. The anatomic position of the pudendal and cavernous nerves appears to account for the impotence. The use of a foam-rubber fitting for the perineal post is recommended.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
6/8. Prevention and management of pressure sores.Continuity of care is needed when transferring patients at risk of developing pressure sores. The tools used to assess such patients must be consistent. A turning clock system has been developed for use with the patient.- - - - - - - - - - ranking = 5keywords = pressure (Clic here for more details about this article) |
7/8. hip stress during lifting with bent and straight knees."Correct" body mechanics during lifting are believed to protect the back by employing knee and hip flexion while keeping the back straight. Lower limb joint stress, however, has been largely ignored. We compared hip cartilage contact stress during "leg lifting" with "back lifting" (lifting with bent or straight knees, respectively) in a subject fitted with a pressure instrumented hip endoprosthesis. Synchronized pressure data and whole-body kinematics and kinetics were collected simultaneously while the subject lifted an 11.8 kg mass from the floor to waist level. The highest pressure, 13.7 MPa, occurred during leg lifting at the antero-lateral femoral head transducers opposed at maximum hip flexion by the postero-superior quadrant of acetabular cartilage. In back lifting, the highest pressure, 11.5 MPa occurred in the supero-lateral aspect of the head, which during hip extension was opposed by the posterior quadrant of the acetabulum. Maximum pressures and hip torques occurred simultaneously with peak hip flexion, during the initial lifting of the burden from the floor. Acetabular contact pressures during leg lifting were on average twice as great as during back lifting, and both techniques generate much greater hip stress than gait (typically 4-6 MPa). Degenerative changes in the articular surface of the acetabulum occur primarily on the postero-superior aspect, corresponding to the locations of peak contact pressures in the present in vivo data. Thus leg lifting puts more stress on the postero-superior region, and probably contributes to more hip cartilage degeneration, than does back lifting. We conclude that although leg lifting may mechanically protect the back, it substantially increases hip cartilage stress.- - - - - - - - - - ranking = 7keywords = pressure (Clic here for more details about this article) |
8/8. Acetabular pressures during hip arthritis exercises.OBJECTIVE: To examine in vivo maximum acetabular contact pressures during gait and hip arthritis exercises recommended by clinicians and the Arthritis Foundation. methods: Acetabular contact pressure data were collected for 2.5 years, at 3-4-month intervals, from an instrumented endoprosthesis implanted in an 84-year-old male who had sustained a left hip fracture. Maximum pressure data were compared for each activity. RESULTS: Mean pressures ranged from 9.0 /- 2.3 megapascals (MPa) during maximum isometric hip abduction, 9.0 /- 0.8 MPa during standing right hip abduction, and 8.9 /- 2.8 MPa during standing left hip abduction to 1.2 /- 0.3 MPa during quiet standing. Free-speed gait pressure averaged 5.6 /- 0.9 MPa. The maximum mean pressure during side-lying hip abduction and straight leg raise at 30 degrees/second were less than the same activities at 60 degrees/second. CONCLUSIONS: These in vivo hip pressure measurements challenge traditional protocols for patients with hip osteoarthritis and provide quantitative data as a framework for designing exercise programs. Maximum isometric hip exercise and standing exercise generated much higher hip pressures, and are therefore probably more stressful to acetabular cartilage, than gait or stationary cycling. Clinicians must consider exercise velocity because of its direct correlation with hip contact pressure. walking generated lower pressure than most activities studied and, given its other benefits, is therefore probably beneficial for patients with hip osteoarthritis.- - - - - - - - - - ranking = 14keywords = pressure (Clic here for more details about this article) |