Showing papers in "Journal of Bone and Joint Surgery, American Volume in 1994"

Mesenchymal Cell-Based Repair of Large Full Thickness Defects of Articular Cartilage

Abstract: Osteochondral progenitor cells were used to repair large, full-thickness defects of the articular cartilage that had been created in the knees of rabbits. Adherent cells from bone marrow, or cells from the periosteum that had been liberated from connective tissue by collagenase digestion, were grown in culture, dispersed in a type-I collagen gel, and transplanted into a large (three-by-six-millimeter), full-thickness (three-millimeter) defect in the weight-bearing surface of the medial femoral condyle. The contralateral knee served as a control: either the defect in that knee was left empty or a cell-free collagen gel was implanted. The periosteal and the bone-marrow-derived cells showed similar patterns of differentiation into articular cartilage and subchondral bone. Specimens of reparative tissue were analyzed with use of a semiquantitative histological grading system and by mechanical testing with employment of a porous indenter to measure the compliance of the tissue at intervals until twenty-four weeks after the operation. There was no apparent difference between the results obtained with the cells from the bone marrow and those from the periosteum. As early as two weeks after transplantation, the autologous osteochondral progenitor cells had uniformly differentiated into chondrocytes throughout the defects. This repair cartilage was subsequently replaced with bone in a proximal-to-distal direction, until, at twenty-four weeks after transplantation, the subchondral bone was completely repaired, without loss of overlying articular cartilage. The mechanical testing data were a useful index of the quality of the long-term repair. Twenty-four weeks after transplantation, the reparative tissue of both the bone-marrow and the periosteal cells was stiffer and less compliant than the tissue derived from the empty defects but less stiff and more compliant than normal cartilage. Clinical Relevance: The current modalities for the repair of defects of the articular cartilage have many disadvantages. The transplantation of progenitor cells that will form cartilage and bone offers a possible alternative to these methods. As demonstrated in this report, autologous, bone-marrow-derived, osteochondral progenitor cells can be isolated and grown in vitro without the loss of their capacity to differentiate into cartilage or bone. Sufficient autologous cells can be generated to initiate the repair of articular cartilage and the reformation of subchondral bone. The repair tissues appear to undergo the same developmental transitions that originally led to the formation of articular tissue in the embryo.(ABSTRACT TRUNCATED AT 400 WORDS)

Acceleration of tibial fracture-healing by non-invasive, low-intensity pulsed ultrasound.

Abstract: Sixty-seven closed or grade-I open fractures of the tibial shaft were examined in a prospective, randomized, double-blind evaluation of use of a new ultrasound stimulating device as an adjunct to conventional treatment with a cast. Thirty-three fractures were treated with the active device and thirty-four, with a placebo control device. At the end of the treatment, there was a statistically significant decrease in the time to clinical healing (86 +/- 5.8 days in the active-treatment group compared with 114 +/- 10.4 days in the control group) (p = 0.01) and also a significant decrease in the time to over-all (clinical and radiographic) healing (96 +/- 4.9 days in the active-treatment group compared with 154 +/- 13.7 days in the control group) (p = 0.0001). The patients' compliance with the use of the device was excellent, and there were no serious complications related to its use. This study confirms earlier animal and clinical studies that demonstrated the efficacy of low-intensity ultrasound stimulation in the acceleration of the normal fracture-repair process.

Outcomes after Displaced Fractures of the Femoral Neck. A Meta-Analysis of One Hundred and Six Published Reports.

Abstract: Methods of meta-analysis, a technique for the combination of data from multiple sources, were applied to analyze 106 reports of the treatment of displaced fractures of the femoral neck. Two years or less after primary internal fixation of a displaced fracture of the femoral neck, a non-union had developed in 33 per cent of the patients and avascular necrosis, in 16 per cent. The rate of performance of a second operation within two years ranged from 20 to 36 per cent after internal fixation and from 6 to 18 per cent after hemiarthroplasty (relative risk, 2.6; 95 per cent confidence interval, 1.4 to 4.6). Conversion to an arthroplasty was the most common reoperation after internal fixation and accounted for about two-thirds of these procedures. The remaining one-third of the reoperations were for removal of the implant or revision of the internal fixation. For the patients who had had a hemiarthroplasty, the most common reoperations were conversion to a total hip replacement, removal or revision of the prosthesis, and debridement of the wound. Although we observed an increase in the rate of mortality at thirty days after primary hemiarthroplasty compared with that after primary internal fixation, the difference was not significant (p = 0.22) and did not persist beyond three months. The absolute difference in perioperative mortality between the two groups was small. An anterior operative approach for arthroplasty consistently was associated with a lower rate of mortality at two months than was a posterior approach. Some reports showed promising results after total hip replacement for displaced fractures of the femoral neck; however, randomized clinical trials are still needed to establish the value of this treatment.

Mechanical behavior of the human lumbar and lumbosacral spine as shown by three-dimensional load-displacement curves

Abstract: The lumbar region is a frequent site of spinal disorders, including low-back pain, and of spinal trauma. Clinical studies have established that abnormal intervertebral motions occur in some patients who have low-back pain. A knowledge of normal spinal movements, with all of the inherent complexities, is needed as a baseline. The present study documents the complete three-dimensional elastic physical properties of each lumbar intervertebral level from the level between the first and second lumbar vertebrae through the level between the fifth lumbar and first sacral vertebrae. Nine whole fresh-frozen human cadaveric lumbar-spine specimens were used. Pure moments of flexion-extension, bilateral axial torque, and bilateral lateral bending were applied, and three-dimensional intervertebral motions were determined with use of stereophotogrammetry. The motions were presented in the form of a set of six load-displacement curves, quantitating intervertebral rotations and translations. The curves were found to be non-linear, and the motions were coupled. The ranges of motion were found to compare favorably with reported values from in vivo studies.

The natural history of hereditary multiple exostoses

Abstract: We established a database of hereditary multiple exostoses for the state of Washington, on the basis of a retrospective review of the medical records and a clinical evaluation of family members, to determine the prevalence, clinical range of expression, and rate of malignant degeneration The database comprised forty-six kindreds with 113 affected members; all kindreds had at least one member living in the state of Washington The over-all prevalence was at least one in 50,000 Approximately 10 per cent of the subjects had no family history of multiple exostoses With the use of twenty-three pedigrees that demonstrated an adequate multigenerational history for determination of penetrance of the gene, we identified one unaffected individual among twenty-six obligate heterozygotes, a rate of penetrance of 96 per cent There was no evidence for a substantial reduction of penetrance in female subjects The median age at the time of the diagnosis in the 113 affected individuals was three years (range, birth to twelve years) In a cohort of eighty-four subjects for whom we had complete information, the clinical range of expression was wide: thirty-three (39 per cent) had an obvious deformity of the forearm, eight (10 per cent) had an inequality in the lengths of the limbs, seven (8 per cent) had an angular deformity of the knee, and two (2 per cent) had a deformity of the ankle The average number of operations for the patients for whom the operative history was known was two(ABSTRACT TRUNCATED AT 250 WORDS)

Limb salvage compared with amputation for osteosarcoma of the distal end of the femur. A long-term oncological, functional, and quality-of-life study.

Abstract: The outcome of treatment of nonmetastatic high-grade osteosarcoma in the distal part of the femur was studied in 227 patients from twenty-six institutions. Eight of the seventy-three patients who had had a limb-salvage procedure and nine of the 115 patients who had had an above-the-knee amputation had a local recurrence, but there was no local recurrence in the thirty-nine patients who had had a disarticulation at the hip. There were no significant differences in the rate of survival or in the duration of the postoperative disease-free period between the three groups. One hundred and nine patients (48 per cent) were alive at an average of eleven years after the operation, and ninety patients (40 per cent) remained continuously disease-free. An additional operation on the limb was necessary more often for patients who had had a limb-salvage procedure than for those who had had an amputation. Function in seventy-eight living patients was assessed with the system of the Musculoskeletal Tumor Society for evaluation of function and by the functional assessment portion of the 1989 scoring system of the Knee Society; the scores were higher for the patients who had had a limb-salvage procedure than for the two groups of patients who had had an amputation. No difference was identified between the groups with regard to the patient's acceptance of the postoperative state, the ability to walk, or the amount of pain. The quality of life was evaluated for twenty-nine patients with a series of complex questionnaires.(ABSTRACT TRUNCATED AT 250 WORDS)

Recurrence of giant-cell tumors of the long bones after curettage and packing with cement.

Abstract: The nine-year experience with sixty patients who had had a giant-cell tumor of a long bone was reviewed to determine the rate of recurrence after treatment with curettage and packing with polymethylmethacrylate cement. The demographic characteristics, including the age and sex of the patient and the site of the tumor, were similar to those that have been reported for other large series. An average of four years (range, two to ten years) after the operation, the over-all rate of initial local recurrence was 25 per cent (fifteen of sixty patients). Patients who had had a tumor of the distal aspect of the radius had a higher rate of recurrence (five of ten) than those who had had a tumor of the proximal aspect of the tibia (seven [28 per cent] of twenty-five) or of the distal part of the femur (three [13 per cent] of twenty-three). Higher rates of recurrence were also noted for patients who had had a pathological fracture (three of six), those who had had a Stage-III tumor according to the classification of Campanacci et al. (six of sixteen), and those who had not had adjuvant treatment with either a high-speed burr or phenol (eight of nineteen). Patients who had had an initial recurrence after packing with cement had a low rate of secondary recurrence when the initial recurrence had been treated with a wide resection or a second intralesional procedure (zero of ten and one of five patients, respectively), after an average of three years (range, ten months to eight years). No patient had a multicentric tumor or metastasis.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of recombinant human osteogenic protein-1 on healing of large segmental bone defects.

Abstract: A rabbit ulnar non-union model was used to evaluate the effect of recombinant human osteogenic protein-1 on the healing of a large segmental osteoperiosteal defect. A 1.5-centimeter segmental defect was created in the mid-part of the ulnar shaft of adult rabbits. The defect was filled with an implant containing either recombinant human osteogenic protein-1 or naturally occurring bovine osteogenic protein. The recombinant human osteogenic protein-1 implants consisted of a carrier of 125 milligrams of demineralized, guanidine-extracted, insoluble rabbit bone matrix (the collagen carrier), reconstituted with 3.13, 6.25, 12.5, twenty-five, fifty, 100, 200, 300, or 400 micrograms of recombinant human osteogenic protein-1. Animals that received recombinant human osteogenic protein-1 were compared with animals that received an implant of 250 micrograms of a preparation of naturally occurring bovine osteogenic protein mixed with the collagen carrier. Limbs that served as controls received either the collagen carrier alone or no implant at all. The treated and the untreated defects were examined radiographically and histologically at eight or twelve weeks after implantation. Mechanical testing was performed on six animals. All implants of recombinant human osteogenic protein-1, except for those containing 3.13 micrograms of the substance, induced complete radiographic osseous union within eight weeks. The defects that were treated with an implant of bovine osteogenic protein also healed within this time-period. The bone induced by both types of implants had new cortices with advanced remodeling and marrow elements. Histological evaluation of this new bone at eight weeks postoperatively revealed primarily lamellar bone, with the formation of new cortices and normal-appearing marrow elements. The average torsional strength and energy-absorption capacity of the union induced by recombinant human osteogenic protein-1 was comparable with that of intact bone. The control defects that had been implanted with collagen carrier alone and those with no implant showed no bridging of the defect.

Migration of corrosion products from modular hip prostheses. Particle microanalysis and histopathological findings.

Abstract: Migration of solid corrosion products from the modular head-neck junction of fifteen total hip replacements to the periprosthetic tissues was studied. The devices and tissues were recovered at the time of a revision procedure or at autopsy after a mean of sixty-four months (range, eight to ninety-seven months). The prostheses had a cobalt-chromium-alloy head coupled with a cobalt-chromium-alloy or a titanium-alloy stem. The solid corrosion product was identified by electron microprobe analysis and Fourier transform infrared microprobe spectroscopy as a chromium orthophosphate hydrate-rich material. The product was present at the junction of the modular head and neck and as particles within the periprosthetic tissues as early as eight months postoperatively. In several hips, it was also present on the polyethylene bearing surface. The particles in the tissues ranged in size from less than one to 500 micrometers. They were present within histiocytes or were surrounded by foreign-body giant cells in the pseudocapsule of the hip joint; in the membranes of the femoral bone-implant interface; and at sites of femoral endosteal erosions, with and without loosening of the femoral component.

Biomechanical evaluation of a simulated Bankart lesion.

Abstract: The purpose of this study was to determine the effect of sectioning of the anterior part of the inferior glenohumeral ligament (a simulated Bankart lesion) on load-induced multidirectional glenohumeral motion. Nine fresh, intact cadaveric shoulders were tested on a special apparatus that constrained three rotations but allowed simultaneous measurement of anterior-posterior, superior-inferior, and medial-lateral translation. Coupled anterior-posterior and superior-posterior translations were recorded while anterior, posterior, superior, and inferior forces of fifty newtons were applied sequentially. Testing was done in three positions of humeral elevation in the scapular plane, in three positions of humeral rotation, and with an externally applied joint-compression load of twenty-two newtons. A liquid-metal strain-gauge was placed on the posterior band of the inferior glenohumeral ligament to assess concomitant posterior capsular strain during the various test conditions. All shoulders were tested intact and again after the inferior glenohumeral ligament and the labrum had been detached from the glenoid from just superior to the anterior band of the inferior glenohumeral ligament to a point just posterior to the infraglenoid tubercle. The simulated Bankart lesion resulted in selected increases in anterior translation at all positions of elevation, in posterior translation at 90 degrees of elevation, and in inferior translation at all positions of elevation. However, these increases were very small; the maximum mean increase in translation seen over-all was only 3.4 millimeters, which occurred during inferior translation at 45 degrees of elevation.(ABSTRACT TRUNCATED AT 250 WORDS)

Fractures of the Proximal Part of the Femur

Abstract: The orthopaedic surgeon has a multitude of internal fixation devices and techniques available for use in the treatment of subtrochanteric fractures of the proximal femur. The successful use of second-generation locking nails is technically demanding. Close attention to positioning of the patient, reduction of the fracture, placement of the guide-wire, and insertion of the nail and of the proximal and distal locking screws is mandatory. The newer, high-strength hip-screws allow good fixation of a fracture that extends into the piriformis fossa. If medial comminution is present, this technique is best performed in conjunction with indirect reduction and bone-grafting. With proper technique, these devices allow the surgeon to manage predictably a complex subtrochanteric fracture that previously had to be treated with traction or extensive dissection and with (frequently inadequate) internal fixation.

Reflex inhibition of the quadriceps femoris muscle after injury or reconstruction of the anterior cruciate ligament.

Abstract: A burst-superimposition technique was used to assess the strength of the quadriceps femoris muscle in three groups of patients. Group 1 comprised twenty patients who had had a torn anterior cruciate ligament of the knee and had a reconstruction of the ligament one to six months after the injury. Group 2 comprised twelve patients who had had a torn anterior cruciate ligament for an average of three months (a subacute tear). Group 3 comprised eight patients who had had a torn anterior cruciate ligament for an average of two years (a chronic tear). The patients in Groups 2 and 3 had not had an operation for the torn ligament. The patients in Groups 1 and 3 had no evidence of failure of activation of the involved quadriceps, but nine of the twelve patients in Group 2 had reflex inhibition of contraction of the muscle.

The Milwaukee brace for the treatment of adolescent idiopathic scoliosis. A review of one thousand and twenty patients.

Abstract: We reviewed the medical records and roentgenograms of 1020 patients who had been managed for adolescent idiopathic scoliosis, between January 1954 and December 1979, with a Milwaukee brace; we wished to determine whether use of the brace had effectively altered the natural history of the disease. The findings were considered with respect to a previous study of 727 children who had had comparable curves and had not initially been managed with the brace but had been followed for progression of the curve, during the same time-span as that in the current study. Of those 727 patients, 558 (77 percent) had no progression of the curve. The average age of the 1020 patients at the time that treatment with the brace was begun was thirteen and one-half years (range, ten to seventeen years). None of the patients had received any other treatment, and all had been managed only by the physicians participating in this study. In both the current and the earlier series, the outcome was considered a failure if the curve had increased 5 degrees or more; in the patients in the current study, who were managed with the brace, the outcome was also considered a failure if operative intervention had been needed. Of the 1020 patients in the current series, 229 (22 percent) had operative intervention; this rate was higher in the patients who had a curve of more than 30 degrees at the time of bracing and in those who had a Risser sign of 0 or 1. The 791 remaining patients, who were managed with the brace only, had a mild improvement of 1 to 4 degrees at the time that use of the brace was discontinued (the difference being within the margin of error of measurement). With respect to curves of between 20 and 39 degrees, the rate of failure was lower in the current series of patients who had been managed with the brace than in the earlier series of patients who had not been thus managed but had been followed for progression. Progression of the curve was found to be related to the pattern and magnitude of the curve; the age of the patient at the time of presentation; the Risser sign; and, in girls, the menarchal status. We recommend that immature adolescents who have a curve of more than 25 degrees and a Risser sign of 0 be managed with a brace immediately, rather than after progression has been documented.

Interobserver agreement in the classification of open fractures of the tibia. The results of a survey of two hundred and forty-five orthopaedic surgeons

Abstract: The system of Gustilo and Anderson for the classification of open fractures is commonly used as a basis for treatment decisions and for comparison of the published results of treatment. The reliability of this classification system was tested on the basis of the responses of 245 orthopaedic surgeons to a survey. The respondents were asked to provide data about their age, type of practice, and type of training; the number of open fractures of the tibia that they treated each year; and their use of the Gustilo-Anderson classification system. They were also asked to classify twelve open fractures of the tibia on the basis of a series of videotaped case presentations. Each case presentation on the color videotape included demographic data on the patient, a history of the injury, the results of the physical examination, the appearance and dimensions of the open wound before the operation, preoperative radiographs, and selected portions of the operative debridement with narration. The level of agreement for the classification of each fracture was determined according to the largest percentage of observers who chose a single classification type. The average agreement among the observers for all twelve fractures was 60 percent. The over-all agreement for each fracture ranged from 42 to 94 percent. The average agreement in the subgroup of surgeons who were considered to have the least experience (residents and fellows) was 59 per cent (range, 33 to 94 percent).(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between the design, position, and articular wear of acetabular components inserted without cement and the development of pelvic osteolysis.

Abstract: Between 1983 and 1987, an acetabular component with a unique chamfered-cylinder design was inserted without cement in 134 hips. With use of this design, initial stability is achieved through a cylindrical interference fit with the peripheral rim of the acetabulum, without the need for pegs, spikes, or screws. At an average of sixty-four months (range, forty to ninety-six months) after implantation, follow-up data were available for 113 hips (ninety-three patients). No component had been revised for loosening or was radiographically loose. However, the prevalence of balloon-like osteolysis of the pelvis was 17 per cent (nineteen hips). This bone loss was generally not associated with pain or other symptoms. Ten of the nineteen hips that were associated with pelvic osteolysis (including six of the nine that were associated with osteolysis of the ilium) had been reconstructed with use of an acetabular component that had no holes in the shell (that is, the shell was completely solid). This finding indicates that, while elimination of holes through the acetabular shell may have advantages, it will not prevent pelvic osteolysis. The osteolysis of the ilium was associated with a lateral opening of the acetabular component of more than 50 degrees (p < 0.0001). All of the hips in this series had insertion of a porous-ingrowth femoral resurfacing component made of titanium alloy. These components are no longer used. Revision of the femoral side due to osteolysis provided a unique opportunity to inspect directly forty-two clinically well functioning acetabular components. All of the polyethylene liners and acetabular shells were found to be rigidly fixed. Inflammatory tissue at the periphery of the implant-bone interface resulted in circumferential resorption of periacetabular bone despite rigid fixation of the component. This is direct evidence that a process of bone resorption similar to that reported at the cement-bone interface of cemented acetabular components can occur at the implant-bone interface of components inserted without cement. At the reoperation, a communication that had led to the pelvic osteolysis was found through areas of bone resorption at the periphery of the implant-bone interface. These areas were essentially cystic and were filled with a mixture of fluid and friable, yellow-tan tissue. It appeared that the osteolytic process had expanded into the soft cancellous bone and marrow while being contained by the denser cortical shell of the pelvic bones.(ABSTRACT TRUNCATED AT 250 WORDS)

Torsional strength of pin configurations used to fix supracondylar fractures of the humerus in children.

Abstract: Supracondylar fractures of the humerus in children are commonly treated with closed reduction and percutaneous pin fixation. Using an adult human cadaver model, we measured the resistance to internal rotation of the distal fragment of simulated supracondylar fractures, fixed with four different configurations of pins. The maximum stability was provided by two crossed pins placed from the medial and lateral condyles. In comparison, the torque required to produce 10 degrees of rotation averaged 37 per cent less with use of two lateral parallel pins and 80 per cent less with use of two lateral crossed pins (p < 0.05 for both). The average torque required to produce 10 degrees of rotation with use of three lateral pins was 25 per cent less than with use of two medial and lateral crossed pins, although the difference was not significant.

The cement mantle in total hip arthroplasty. Analysis of long-term radiographic results.

Abstract: The correlation between the thickness of the cement mantle, the medullary canal fill, and the orientation of the stem and the long-term radiographic outcome of 836 cemented femoral components in patients who had a primary total hip replacement was assessed with use of survival analysis over a twenty-one-year follow-up period. The femoral stems of hips that had a two to five-millimeter-thick cement mantle in the proximal medial region had a better outcome than stems implanted with a thicker or thinner cement mantle. Stems in femora with less than two millimeters of proximal medial cancellous bone had a better outcome than stems in femora with thicker cancellous bone. Stems that filled more than half of the medullary canal had better radiographic results than those that filled half or less. Progressive loosening, fracture of the cement, and radiolucent lines at the stem-cement or bone-cement interfaces were more likely to develop in stems that were oriented in more than 5 degrees of varus than in those in neutral or valgus. The noted correlations were true whether the stem was made of titanium alloy or of stainless steel. The results of this study emphasize the importance of careful preoperative planning in total hip arthroplasty done with cement and provide guidelines for the selection of the shape, size, and position of the stem.

Isolation and characterization of debris in membranes around total joint prostheses.

Abstract: Particles of wear debris have been implicated in osteolysis around and aseptic loosening of total joint prostheses, but the number and size distribution of particles present in periprosthetic tissues are unknown. A method of particle assay was developed, consisting of nitric-acid digestion of tissue followed by collection of particles, electronic quantitation, and parallel morphological and chemical characterization. Nitric acid had minimum deleterious effects on control samples of titanium, cobalt-chromium alloy, and polyethylene particles, as determined by atomic absorption spectroscopy, scanning electron microscopy, and electronic measurements of the sizes of the particles. Acid digestion of twelve control samples of tissue, including tissue rich in hemosiderin, resulted in particle counts that were no higher than that in the digestion solution background. Other digestion preparations, including hydrochloric acid and sodium hypophosphate, were not as effective as nitric acid. With the low size limit of detection of approximately 0.58 micrometer, particle analysis of tissue adjacent to twenty retrieved total joint implants indicated a range of concentration of 0.85 to 141.85 x 10(9) particles per gram of tissue (dry weight). Although a few particles of more than 100 micrometers were detected, the mode of particle diameter from each sample ranged from the lower limit of detection (approximately 0.58 micrometer) to 0.79 micrometer. The findings of morphological studies and x-ray spectroscopy of isolated particles corresponded with those of light microscopy of the fibrous membranes. These data indicate that most of the particles in implant membranes are smaller than the resolution of the light microscope and that tissue digestion is necessary for quantitation and characterization.

Fixation with Bioabsorbable Screws for the Treatment of Fractures of the Ankle.

Abstract: One hundred and fifty-five patients who had a closed, displaced medial malleolar, bimalleolar, or trimalleolar fracture of the ankle were managed with medial malleolar fixation with use of either 4.0-millimeter orientruded polylactide screws (eighty-three patients, study group) or 4.0-millimeter stainless-steel screws (seventy-two patients, control group). All lateral malleolar fractures were stabilized with standard metallic implants. At an average of thirty-seven months (range, twenty-one to fifty-nine months), the radiographic and functional results in the two groups were equivalent. Differences between the two groups with regard to the rates of operative and postoperative complications were not statistically significant. Late spontaneous drainage of the hydrolyzed polylactide was not noted in any patient in the study group. The prevalence of late tenderness over the medial malleolar implant was lower in the patients in whom the fracture had been stabilized with polylactide screws. We conclude that polylactide screws are a safe and effective alternative to stainless-steel screws for the fixation of displaced medial malleolar fractures.

Closed reduction for congenital dysplasia of the hip. Functional and radiographic results after an average of thirty years

Abstract: The functional and radiographic results of closed reduction in 152 congenitally dislocated hips of 119 patients who had been managed between 1938 and 1969 were reviewed retrospectively. The average age of the patients at the time of the reduction was twenty-one months (range, one to ninety-six months). At the time of the latest follow-up evaluation, the average age was thirty-one years (range, sixteen to fifty-six years). The average duration of follow-up was thirty years (range, fifteen to fifty-three years). At the latest follow-up evaluation, the Iowa hip rating averaged 91 points (range, 38 to 100 points) and the Harris hip score averaged 90 points (range, 33 to 100 points). Thirty-five hips were rated Severin Class I; thirty-five, Class II; twenty-eight, Class III; fifty-three, Class IV; and one, Class VI. Disturbance of growth in the proximal end of the femur occurred in ninety-one hips (60 per cent). Eight contralateral hips that had appeared normal also demonstrated disturbance of proximal femoral growth. In many hips, partial physeal arrest could not be determined for ten to twelve years after the reduction. Seventeen hips (twelve patients) had a total replacement when the patients were an average age of thirty-six years (range, nineteen to fifty-three years). Sixty-five hips (43 per cent) had radiographic evidence of degenerative joint disease. Patients who did not have a growth disturbance of the proximal end of the femur or evidence of subluxation tended to function extremely well for many years despite a radiographic result that was less than anatomical. Function tended to deteriorate with time, even in the absence of disturbance of growth in the proximal end of the femur. Despite generally good function at the latest follow-up evaluation, the prognosis for these patients remained guarded.

Changes in the moment arms of the rotator cuff and deltoid muscles with abduction and rotation

Abstract: The behavior of the moment arms of the rotator cuff and deltoid muscles was studied during simple and combine movements of abduction and rotation about the glenohumeral joint. This was done by experimental measurement of excursions of the muscles in an in vitro cadaver model and by use of a multiple-regression analysis to delineate the changes in the moment arms as a function of abduction and rotation. The results demonstrated the potential of some rotator cuff muscles to contribute to both abduction and rotation, the sensitivity of the abductor moment-arm lengths to internal and external rotation and of the rotator moment-arm lengths to the degree of abduction, and the capacity of the abductor moment-arm lengths of the deltoid to increase with increasing abduction. Characterization of this behavior resulted in an increased understanding of the complex role of the rotator cuff and deltoid muscles about the gleno-humeral joint and provided quantitative descriptions of functional relationships. This study demonstrates the capacity of the infraspinatus and subscapularis muscles to contribute not only to external and internal rotation, respectively, but also to elevation of the arm in the plane of the scapula, a role for which these muscles have been given little or no consideration. Furthermore, it demonstrates that the contribution of the infraspinatus to abduction is enhanced with internal rotation while that of the subscapularis is enhanced with external rotation. Thus, dysfunction of the supraspinatus muscle need not preclude good elevation of the arm, and rehabilitation to reprogram and strengthen the remaining muscles becomes an important consideration.

Functional Recovery After Fracture of the Hip

Abstract: Fracture of the hip remains one of the most common and potentially devastating injuries in the geriatric population. These fractures have an impact that extends far beyond the obvious orthopaedie injury into the domains of medicine, rehabilitation, psychiatry, social work, and economics. Fractures of the proximal pant of the femur continue to consume a major portion of national healthcane resources’235; their importance becomes even more apparent because of the increasing number that occur each year3’. in the face of increasing pressure for the containment of costs at all levels of our system of health care55. Despite improvements in patient care, including advances in operative technique and implant technology. the outcome of treatment often falls short of expeetations. All too often. the operation is successful in terms of healing of the fracture but the patient is unable to regain the preinjuny level of function and independence: a true measure of the successful treatment of any injury or disease is to what extent the patient has returned to the premorbid level of function. Knowledge of both positive and negative predictors of outcome is needed to guide treatment, planning of the discharge of the patient from the hospital, and utilization of health-care

A prospective, double-blind trial of electrical capacitive coupling in the treatment of non-union of long bones.

Abstract: Twenty-three patients who had an established non-union of a long bone were entered into a prospective, double-blind trial in which electrical capacitive coupling was used for treatment. Twenty-one patients completed the study: ten who were actively managed and eleven who were managed with a placebo unit. The non-union healed in six of the ten patients who had been managed actively but in none of the patients who had been managed with the placebo unit. This difference in the rates of healing between the actively managed and the placebo groups is highly significant (p = 0.004).

Parosteal osteosarcoma. A clinicopathological study

Abstract: The records of 226 patients (sixty-seven who were managed at our institution and 159 who were identified from the consultation files) who had had a parosteal osteosarcoma were reviewed. The criteria for diagnosis were that, roentgenographically, the lesion had arisen from the surface of the bone and that, histologically, the tumor was well differentiated (Grade 1 or 2); it was characterized by well formed osteoid within a spindle-cell stroma; and, when there was medullary involvement, less than 25 per cent of the medullary cavity was affected. Dedifferentiation was more common (16 per cent of the patients) than previously reported and was associated with a poor prognosis. Cross-sectional imaging studies demonstrated medullary involvement in 22 per cent of the patients, an unmineralized soft-tissue mass peripheral to the mineral component in 51 per cent, and adjacent soft-tissue invasion in 46 per cent. In contrast to the findings in our previous studies, medullary involvement was not a poor prognostic factor. At an average of thirteen years (range, two to forty-one years), eleven of the sixty-seven patients who were managed at our institution died of the tumor; ten of these patients had a dedifferentiated tumor. Statistical analysis of the thirty-nine patients who had had the primary treatment at our institution revealed that incomplete resection was associated with an increased risk of local recurrence and that dedifferentiation markedly increased the risk of metastasis.

Micromotion of femoral stems in total hip arthroplasty. A randomized study of cemented, hydroxyapatite-coated, and porous-coated stems with roentgen stereophotogrammetric analysis.

Abstract: The fixation of the femoral stem in a total hip arthroplasty was studied in sixty patients (sixty-four hips) with use of roentgen stereophotogrammetric analysis. The hips were randomly stratified on the basis of the age, sex, and weight of the patient; the roentgenographic quality of the bone; and the reason for the operation (primary or secondary osteoarthrosis). The hips were then randomly assigned to one of three types of fixation of the femoral component: insertion with cement, hydroxyapatite coating, or porous coating. Examinations with roentgen stereophotogrammetry were done as long as two years after the operation. Micromotion of the prostheses was evaluated in terms of subsidence or proximal migration and rotations and translations of the proximal-lateral (shoulder) and distal (tip) parts of the prostheses. The clinical results at the two-year follow-up evaluation did not differ significantly between the groups with regard to the Harris hip score or the pain score (p > 0.05 for both; Wilcoxon rank-sum test). There were small or no differences in rotations and micromotions of the shoulder and the tip of the prostheses. Increased subsidence of 0.1 to 0.2 millimeter was recorded for the cemented and the porous-coated prostheses (p = 0.002 and p = 0.02, respectively; Wilcoxon rank-sum test). Thus, proximal hydroxyapatite coating seems to enhance the early fixation of the stem. Conventional roentgenography revealed an increased number of radiodense lines surrounding the porous-coated prostheses. Distal hypertrophy of the femoral cortex was found mainly around the hydroxyapatite-coated prostheses. Proximal resorption of bone and heterotopic ossification occurred to approximately the same extent regardless of the type of fixation used.

Compartment pressure in association with closed tibial fractures. The relationship between tissue pressure, compartment, and the distance from the site of the fracture.

Abstract: We studied twenty-five consecutive patients who had a closed tibial fracture to determine whether there was a relationship between compartment pressure and the distance at which the pressure was measured from the site of the fracture. Tissue pressure was measured in all four compartments of the leg at the level of the fracture and at five-centimeter increments proximal and distal to the fracture. The peak pressure was usually found at the level of the fracture and was always located within five centimeters of the fracture. The highest pressures were recorded in the anterior and the deep posterior compartments in twenty patients, including all five of those who had had a fasciotomy. The measured pressure decreased steadily when sampled at increasing distances proximal and distal to the site of the highest recorded pressure. Decreases of twenty millimeters of mercury (2.67 kilopascals) five centimeters adjacent to the site of the peak pressure were common. Compartment syndrome was diagnosed in five patients on the basis of clinical findings, and the diagnosis was confirmed when peak compartment pressures of more than the critical threshold (within twenty millimeters of mercury [2.67 kilopascals] of the diastolic blood pressure) were recorded. Three of these five patients had measured pressures that were less than the critical threshold within five centimeters of the site of the peak pressure. Failure to measure tissue pressure within a few centimeters of the zone of peak pressure may result in a serious underestimation of the maximum compartment pressure. Our results suggest that measurements should be performed in both the anterior and the deep posterior compartments at the level of the fracture as well as at locations proximal and distal to the zone of the fracture to determine reliably the location of the highest tissue pressure in a lower extremity when a compartment syndrome is suspected clinically. The highest pressure should be used in the decision-making process.

Effects of Gamma Irradiation on the Human Immunodeficiency Virus. A Study in Frozen Human Bone-Patellar Ligament-Bone Grafts Obtained from Infected Cadavera.

Abstract: We studied the effects of several different doses of gamma radiation, ranging from 20,000 to 40,000 gray (2.0 to 4.0 megarad), with respect to the inactivation of the human immunodeficiency virus in fresh-frozen, whole bone-patellar ligament-bone grafts. Although the International Atomic Energy Agency has recommended the use of 25,000 gray of gamma radiation for the sterilization of medical products, the dose required for the inactivation of the human immunodeficiency virus in frozen allografts has not been established. Using one of the most sensitive and specific tests for the detection of the human immunodeficiency virus, the polymerase-chain-reaction test, we found that doses of 20,000 or 25,000 gray of gamma radiation did not destroy the genes of the human immunodeficiency virus effectively; DNA of the virus was detectable in the DNA of bone-marrow tissue obtained from grafts treated with these doses. However, DNA of the human immunodeficiency virus was not detectable in the grafts treated with 30,000 or 40,000 gray of gamma radiation. We conclude that a dose of 30,000 gray of gamma radiation or more is necessary for the sterilization of a fresh-frozen bone-patellar ligament-bone allograft, so that it can be used for reconstructive procedures without the risk of transmission of the virus to the recipient.