Showing papers in "Clinical Orthopaedics and Related Research in 2000"
TL;DR: The good clinical outcomes of autologous chondrocyte transplantation in this study are encouraging, and clinical trials are being done to assess the outcomes versus traditional fibrocartilage repair techniques.
Abstract: Autologous cultured chondrocyte transplantation was introduced in Sweden in 1987 for the treatment of large (1.5-12.0 cm2) full thickness chondral defects of the knee. The clinical, arthroscopic, and histologic results from the first 101 patients treated using this technique are reported in this study. Patients were assessed retrospectively using three types of endpoints: patient and physician derived clinical rating scales (five validated and two new); arthroscopic assessment of cartilage fill, integration, and surface hardness; and standard histochemical techniques. Ninety-four patients with 2- to 9-years followup were evaluable. Good to excellent clinical results were seen in individual groups as follows: isolated femoral condyle (92%), multiple lesions (67%), osteochondritis dissecans (89%), patella (65%), and femoral condyle with anterior cruciate ligament repair (75%). Arthroscopic findings in 53 evaluated patients showed good repair tissue fill, good adherence to underlying bone, seamless integration with adjacent cartilage, and hardness close to that of the adjacent tissue. Hypertrophic response of the periosteum or graft or both was identified in 26 arthroscopies; seven were symptomatic and resolved after arthroscopic trimming. Graft failure occurred in seven (four of the first 23 and three of the next 78) patients. Histologic analysis of 37 biopsy specimens showed a correlation between hyalinelike tissue (hyaline matrix staining positive for Type II collagen and lacking a fibrous component) and good to excellent clinical results. The good clinical outcomes of autologous chondrocyte transplantation in this study are encouraging, and clinical trials are being done to assess the outcomes versus traditional fibrocartilage repair techniques.
1,403 citations
TL;DR: Graft materials are likely to become more specialized for use in specific clinical applications, and composite preparations may soon provide bone graft materials with efficacy that equals or exceeds that of autogenous grafts.
Abstract: Autograft, allograft, and synthetic bone graft substitute materials play an important role in reconstructive orthopaedic surgery, and understanding the biologic effects of these materials is necessary for optimum use. Although vascularized and cancellous autograft show optimum skeletal incorporation, host morbidity limits autograft availability. Experimental studies have confirmed an immune response to allograft bone, but the clinical significance of this response in humans still is unclear. Small amounts of cancellous allograft in humans usually are remodeled completely; large allografts become incorporated by limited, surface intramembranous bone formation suggesting that these graft are primarily osteoconductive. Several synthetic skeletal substitute materials also are osteoconductive, and may show remodeling characteristics similar to allograft. Demineralized bone matrix and some isolated or synthetic proteins can induce endochondral bone formation, and therefore are osteoinductive. The extent and distribution of remodeling of bone graft materials are influenced by many factors, including the quality of the host site and the local mechanical environment (strain). Graft materials are likely to become more specialized for use in specific clinical applications, and composite preparations may soon provide bone graft materials with efficacy that equals or exceeds that of autogenous grafts.
1,153 citations
TL;DR: In this paper, the average volumetric wear rate per million cycles with a 70 kg patient weight was 30 mm 3, which can be considered a target wear rate for standard polyethylene in hip simulator studies.
Abstract: Polyethylene wear (linear penetration) in 37 hip replacements was assessed from digital images using a validated two-dimensional, edge detection-based computer algorithm. Patient activity was assessed with a pedometer, a step activity monitor and a simple visual analog scale. Joint use was related to wear at the 90% confidence level. Without three recognized outliers, wear was highly correlated to use. The visual analog scale activity rating was significantly related to wear for the 24 hip replacements with standard polyethylene. Univariate regression analysis indicated that male gender, height, weight (which were both highly correlated to male gender) and hip center of rotation were significantly correlated to wear. Multivariate regression analysis indicated that male gender, femoral off-set, and Hylamer® were significantly correlated to wear. Based on the wear and activity data from the 24 hip replacements with standard polyethylene, the average volumetric wear rate per million cycles with a 70 kg patient weight was 30 mm 3 . This unique in vivo result can be considered a target wear rate for standard polyethylene in hip simulator studies.
455 citations
TL;DR: Several markers of increased risk of the occurrence of a foreign body reaction were found, including a poorly vascularized bone section such as scaphoid, use of a quinone dye as an additive in the polymer, and an implant geometry with large surface area (screw versus pin or rod).
Abstract: Among 2528 patients operated on using pins, rods, bolts, and screws made of polyglycolic acid or polylactic acid, 108 (4.3%) were affected by a clinically significant local inflammatory, sterile tissue reaction. The three most common indications for the use of these fixation devices were a displaced malleolar fracture, a chevron osteotomy for hallux valgus, and a displaced fracture of the radial head. In 107 patients, the reaction was elicited by a polyglycolic acid implant, and in one patient by a polylactic acid implant. The incidences were 5.3% (107 of 2037) and 0.2% (one of 491), respectively. The adverse tissue responses to polyglycolic acid were seen 11 weeks after the operation, on average, whereas the reaction to polylactic acid occurred 4.3 years after fixation of an ankle fracture. The mild reactions consisted of a painful erythematous papule of a few weeks' duration. Those of medium severity had a sinus that discharged remnants of the implant for up to 6 months. In the patients affected by severe reactions, extensive osteolytic lesions developed at the implant tracks. The histopathologic picture was that of a nonspecific foreign body reaction. In four patients with vigorous reactions, an arthrodesis of the wrist or ankle later was necessary because of severe osteoarthritis. Several markers of increased risk of the occurrence of a foreign body reaction were found. These included a poorly vascularized bone section such as scaphoid, use of a quinone dye as an additive in the polymer, and an implant geometry with large surface area (screw versus pin or rod). For polyglycolic acid implants, the risk of an adverse tissue response in a given clinical situation can be estimated from the findings of this study. For slow degrading polymers like polylactic acid, however, the ultimate biocompatibility still is unsettled, and additional clinical research with long followup is required.
447 citations
TL;DR: Analyzing the clinical experience of more than 20 years, it can be concluded that all the improvements have produced reliable ceramic femoral heads.
Abstract: In the 1970s it was first realized that the properties of alumina ceramics could be exploited to provide better implants for orthopaedic applications. Applications depend on the fact that ceramics provided wear characteristics suitable for bearing surfaces in total hip replacement. Resultant orthopaedic use had more than 20 years' clinical success. To date more than 2.5 million alumina femoral heads have been implanted. Published reports of fracture rates of the alumina heads range between 0% for ceramics manufactured after 1990 and 13.4% for ceramics manufactured before 1990. These high fracture rates were caused by materials manufactured by companies that are not on the market today. These old aluminas had a low density, had a very coarse microstructure, and were not in compliance with specifications that are valid today. Materials scientists have substantially improved the mechanical strength of alumina. There are three generations of medical grade aluminas. The latest generation is an alumina that is hot isostatic pressed, laser marked, and proof tested. This material has been on the market since 1994. The fracture rates of the most commonly used ceramics have been analyzed by various groups, and are based on.5 million femoral heads to 1.5 million femoral heads. The fracture rate of ceramic Biolox femoral heads are 0.026% for first generation alumina, 0.014% for second generation alumina, and 0.004% for femoral heads manufactured after 1994. Analyzing the clinical experience of more than 20 years, it can be concluded that all the improvements have produced reliable ceramic femoral heads.
341 citations
TL;DR: Treatment options including benign neglect, home-based and supervised physical therapy, intraarticular corticosteroid injections, closed manipulations, and arthroscopic capsular release will be reviewed critically and the authors' approach to the treatment of patients with idiopathic adhesive capsulitis also will be presented.
Abstract: Adhesive capsulitis of the shoulder is a condition of unknown etiology that results in the development of restriction of active and passive glenohumeral motion. The authors will review what currently is known about the etiology of idiopathic adhesive capsulitis, will raise unanswered questions regarding etiology and treatment, and will define a stage-based evaluation and treatment program. Treatment options including benign neglect, home-based and supervised physical therapy, intraarticular corticosteroid injections, closed manipulations, and arthroscopic capsular release will be reviewed critically and the authors' approach to the treatment of patients with idiopathic adhesive capsulitis also will be presented. Additionally, areas of future research will be defined.
333 citations
TL;DR: In this article, the authors evaluated the effect of articulating spacers on the reinfection rate and bone loss in a two-stage total knee arthroplasty with static and non-articulating spacer blocks.
Abstract: Antibiotic laden spacer blocks frequently are used to treat an infected total knee arthroplasty. Static spacer blocks make exposure at reimplantation difficult secondary to quadriceps shortening. Unexpected bone loss attributable to migration of the spacer block also has been reported. To avoid these problems, a temporary articulating molded implant made of antibiotic cement was used in a consecutive series. The authors sought to determine whether its use would affect the reinfection rate, improve functional results, or prevent bone loss compared with static spacers. Twenty-five patients were treated with static nonarticulating spacers. Since 1996, 30 patients have been treated with tobramycin-laden articulating spacers. The knee arthroplasties in three patients treated with a static spacer became reinfected (12%). The knee arthroplasty in one patient with an articulating spacer became reinfected (7%). Fifteen of the 25 patients with static spacers had unexpected bone loss between stages. No appreciable bone loss could be measured in the patients who received articulating spacers. The average Hospital for Special Surgery score was 83 points in the patients with static spacers and 84 points for the patients with articulating spacers. Range of motion at final followup averaged 98° in the patients who received static spacers and 105° in the patients who received articulating spacers. Articulating spacers seem to facilitate reimplantation of infected total knee arthroplasty without additional risk of infection. Unexpected bone loss is no longer a concern with this two-stage technique. Articulating spacers offered no functional advantage over static spacers in this study group.
314 citations
TL;DR: The most recent scientific studies of intrinsic and extrinsic risk factors thought to be contributing to the high rate of female anterior cruciate ligament injuries will be reviewed, important differences will be highlighted, and recommendations proposed to alleviate or minimize these risk factors among female athletes will be reported where appropriate.
Abstract: In the general population, an estimated one in 3000 individuals sustains an anterior cruciate ligament injury per year in the United States, corresponding to an overall injury rate of approximately 100,000 injuries annually. This national estimate is low for women because anterior cruciate ligament injury rates are reported to be two to eight times higher in women than in men participating in the same sports, presenting a sizable health problem. With the growing participation of women in athletics and the debilitating nature of anterior cruciate ligament injuries, a better understanding of mechanisms of injury in women sustaining anterior cruciate ligament injuries is essential. Published studies strongly support noncontact mechanisms for anterior cruciate ligament tears in women, which make these injuries even more perplexing. Speculation on the possible etiology of anterior cruciate ligament injuries in women has centered on anatomic differences, joint laxity, hormones, and training techniques. Investigators have not agreed on causal factors for this injury, but they have started to profile the type of athlete who is at risk. In the current study the most recent scientific studies of intrinsic and extrinsic risk factors thought to be contributing to the high rate of female anterior cruciate ligament injuries will be reviewed, important differences will be highlighted, and recommendations proposed to alleviate or minimize these risk factors among female athletes will be reported where appropriate.
251 citations
TL;DR: The clinical presentation, diagnosis, radiographic features, mechanism, pathologic changes, and treatment of elbow instability are understood better now.
Abstract: The clinical presentation, diagnosis, radiographic features, mechanism, pathologic changes, and treatment of elbow instability are understood better now. Elbow instability can be classified according to five criteria: (1) the timing (acute, chronic or recurrent); (2) the articulation(s) involved (elbow versus radial head); (3) the direction of displacement (valgus, varus, anterior, posterolateral rotatory); (4) the degree of displacement (subluxation or dislocation); and (5) the presence or absence of associated fractures. Posterolateral rotatory instability is the most common pattern of elbow instability, particularly that which is recurrent. Posterolateral rotatory instability can be considered a spectrum consisting of three stages according to the degree of soft tissue disruption. Patients typically present with a history of recurrent painful clicking, snapping, clunking, or locking of the elbow and careful examination reveals that this occurs in the extension portion of the arc of motion with the forearm in supination. There are four principle physical examination tests. The most sensitive is the lateral pivot-shift apprehension test, or posterolateral rotatory apprehension test, just as the anterior apprehension test of the shoulder is the most sensitive test for a patient with shoulder instability. Next is the lateral pivot-shift test, or posterolateral rotatory instability test. Reproducing the actual subluxation and the clunk that occurs with reduction usually can be accomplished only with the patient under general anesthesia or occasionally after injecting local anesthetic into the elbow. The third test is the posterolateral rotatory drawer test, which is a rotatory version of the drawer or Lachman test of the knee. The final test is the stand up test as reported by Regan. The patient's symptoms are reproduced as he or she attempts to stand up from the sitting position by pushing on the seat with the hand at the side and the elbow fully supinated. A lateral stress radiograph can show the rotatory subluxation.
239 citations
TL;DR: A thorough knowledge of pelvic osseous anatomy, injury patterns, deformities, and their fluoroscopic correlations are mandatory for percutaneous pelvic fixation to be effective.
Abstract: Percutaneous pelvic fixation is possible because intraoperative fluoroscopic imaging and other technologies have been refined. Anterior and posterior unstable pelvic ring disruptions are amenable to percutaneous fixation after closed manipulation or open reduction. Stable and safe fixation is achieved only after an accurate reduction. Anterior pelvic external fixation remains the most common form of percutaneous pelvic fixation; however, percutaneously inserted medullary pubic ramus, transiliac, and iliosacral screws stabilize pelvic disruptions directly while diminishing operative blood loss and operative time. These percutaneous techniques do not decompress the pelvic hematoma allowing early definitive fixation without the risk of additional hemorrhage. Complications associated with open posterior pelvic surgical procedures are similarly avoided by using percutaneous techniques. A thorough knowledge of pelvic osseous anatomy, injury patterns, deformities, and their fluoroscopic correlations are mandatory for percutaneous pelvic fixation to be effective.
239 citations
TL;DR: The purpose of the current study was to determine the variance between balancing the flexion gap with the classic method versus the technique of using fixed femoral landmarks to determine rotation.
Abstract: Ligamentous balancing is a crucial part of total knee arthroplasty. To ensure proper kinematics, balance must be achieved in flexion and extension. Failure to do so may result in limited range of motion, premature polyethylene wear, or patellofemoral tracking problems. Balancing in extension is dependent on the type and extent of correctional ligamentous release. Flexion balance is dependent on proper femoral rotation. There are two methods to determine femoral rotation. In the classic method, the knee is tensed in flexion after ligamentous release in extension. The anteroposterior cut then is made parallel to the cut tibial surface. Alternatively, the anteroposterior cut can be based off fixed femoral landmarks. The purpose of the current study was to determine the variance between balancing the flexion gap with the classic method versus the technique of using fixed femoral landmarks to determine rotation. One hundred consecutive posterior stabilized knee arthroplasties were performed using the classic method. The resected posterior condyles in each case were measured. The actual difference between the resected condyles using the classic method was compared with the calculated difference of resected bone using bony landmarks to determine rotation. A variance analysis then was performed. Compared with classically balanced knees, rotational errors of at least 3 degrees occurred in 45 % of patients when rotation was determined from fixed bony landmarks. These patients had trapezoidal rather than rectangular flexion gaps. Such errors may have implications regarding polyethylene wear, range of motion, and long-term clinical results.
TL;DR: The overall conclusion is that the alumina-on-alumina sliding surfaces material is very safe if all the quality requirements are met and impart a long lifetime to the implant in young and active patients.
Abstract: The use of alumina-on-alumina sliding surfaces for total hip replacement is becoming increasingly popular. The author has reviewed the 30-year history of this material. Technical aspects such as the quality of the material, quality of the design, and the risk of fracture are presented. The clinical results observed by the author are summarized with additional references to the results of other surgeons. The overall conclusion is that this material is very safe if all the quality requirements are met. The extremely low generation of wear debris and the excellent biologic tolerance of the material impart a long lifetime to the implant in young and active patients.
TL;DR: Because of the increased incidence of bony and soft tissue complications when treating open or closed Type C fractures, use of limited exposures and stabilization with small wire circular external fixators is recommended.
Abstract: One hundred seven pilon fractures in 107 patients were treated according to a staged prospective protocol. All pilon fractures were stabilized immediately by the application of calcaneal traction. Open fractures or fractures in patients with multiple injuries were stabilized with traveling traction that was applied in the operating room. A distraction computed tomography scan was obtained before definitive treatment. Treatment groups were based on the degree of soft tissue compromise. Forty-one patients with Tscherne Grade 0 or Grade I injuries underwent open reduction and internal fixation (open plating) using contemporary techniques and low-profile implants. Sixty-four patients with Tscherne Grade II and Grade III closed injuries and all patients with open fractures underwent definitive treatment with limited open reduction and stabilization using small wire circular external fixators. Clinical and radiographic evaluations were performed at an average 4.9 years after injury. For all fracture types (AO classification), 81% of the patients who were treated with external fixation and 75% of the patients who were treated with open plating had good or excellent results. For severe fracture patterns (Type C), patients in both groups had significantly poorer results than patients with Types A and B fractures. The patients in the open plating group had a significantly higher rate of nonunion, malunion, and severe wound complications compared with the patients who received external fixation for Type C fracture patterns. Because of the increased incidence of bony and soft tissue complications when treating open or closed Type C fractures, use of limited exposures and stabilization with small wire circular external fixators is recommended.
TL;DR: A literature review of allograft bone use in lumbar spine surgery finds that fresh-frozen grafts are stronger, more immunogenic and more completely incorporated than freeze-dried grafts.
Abstract: Bone grafting is an integral part of many lumbar spinal surgeries. The two choices of bone are autograft and allograft. Each source has its own advantages and disadvantages. The current study is a literature review of allograft bone use in lumbar spine surgery. Allograft bone can be procured in greater quantities than autograft. With standard protocols of harvesting, the risk of disease transfer is negligible. Only fresh-frozen and freeze-dried products are used. Allografts are incorporated slower and to a lesser degree than autografts. Fresh-frozen grafts are stronger, more immunogenic and more completely incorporated than freeze-dried grafts. Allografts used alone or combined with autografts for posterior lumbar spinal procedures have decreased fusion rates compared with autografts. If used anteriorly, allografts are well suited for reconstructive procedures and have good fusion rates, especially if combined with posterior fusions. If used in the proper situations, allograft bone can be used successfully in lumbar spine surgeries.
TL;DR: In this paper, the effects of a lipid lowering agent, lovastatin, on the prevention of steroid induced adipogenesis in vitro in cell culture, and on adipogenesis and osteonecrosis in vivo in chickens, were evaluated.
Abstract: The effects of steroids on a cloned pluripotential cell from bone marrow stroma were examined in vitro in culture and in vivo after the cells were transfected with a traceable gene and transplanted into host mice. Bipedal chickens were treated with steroids to establish a model for osteonecrosis. The effects of a lipid lowering agent, lovastatin, on the prevention of steroid induced adipogenesis in vitro in cell culture, and on adipogenesis and osteonecrosis in vivo in chickens, were evaluated. On treatment with dexamethasone, cloned pluripotential cells began to differentiate into adipocytes and expressed a fat specific gene, whereas the expression of Type I collagen and osteocalcin messenger ribonucleic acid decreased. Addition of lovastatin in culture inhibited steroid induced fat gene expression and counteracted the inhibitory effect of steroids on osteoblastic gene expression. Cloned pluripotential cells were transduced with a traceable retrovirus vector encoding the beta-galactosidase and neomycin resistance genes. The transfected cells were administered to mice either by tail vein or by direct intramedullary injection. Half of the animals in each group were treated with steroids. Histologic sections showed the appearance of transplanted cells in the marrow. Analysis of marrow blowouts by flow cytometry revealed that steroid treatment produced adipogenesis in transplanted cells. Evidence of osteonecrosis was observed in steroid treated chickens, whereas sections from animals treated with steroids and lovastatin showed less adipogenesis and no bone death. The results indicate that steroid induced adipogenesis in the marrow may contribute to osteonecrosis and that lovastatin may be helpful in preventing the development of steroid induced osteonecrosis.
TL;DR: The tendency was always for operatively treated patients to have better outcomes and the strength of evidence to recommend operative treatment for displaced intraarticular calcaneal fractures remains weak.
Abstract: A MEDLINE search from 1980 through 1996 revealed 1845 articles dealing with calcaneal fractures. Six of these articles that compared operative versus nonoperative treatment for displaced calcaneal fractures met the minimum criteria for inclusion in a meta-analysis. A statistical summary of information across the six articles revealed a trend for surgically treated patients to be more likely to return to the same type of work as compared with nonoperatively treated individuals. There also was a trend for nonoperatively treated patients to have a higher risk of experiencing severe foot pain than did operatively treated patients. Unfortunately, none of the other outcomes could be summarized formally across studies using statistical techniques because of variability in reporting across studies. Although the tendency was always for operatively treated patients to have better outcomes (reaching statistical significance in some of the articles), the strength of evidence to recommend operative treatment for displaced intraarticular calcaneal fractures remains weak. A large prospective randomized controlled trial should be able to answer this question.
TL;DR: The grafts containing bone morphogenic protein-7 gene modified cells consistently showed complete or near complete bone and articular cartilage regeneration at 8 and 12 weeks whereas the grafts from the control groups had poor repair as judged by macroscopic, histologic, and immunohistologic criteria.
Abstract: Joint cartilage injury remains a major problem in orthopaedics with more than 500,000 cartilage repair procedures performed yearly in the United States at a cost of hundreds of millions of dollars. No consistently reliable means to regenerate joint cartilage currently exists. The technologies of gene therapy and tissue engineering were combined using a retroviral vector to stably introduce the human bone morphogenic protein-7 complementary deoxyribonucleic acid into periosteal-derived rabbit mesenchymal stem cells. Bone morphogenic protein-7 secreting gene modified cells subsequently were expanded in monolayer culture, seeded onto polyglycolic acid grafts, implanted into a rabbit knee osteochondral defect model, and evaluated for bone and cartilage repair after 4, 8, and 12 weeks. The grafts containing bone morphogenic protein-7 gene modified cells consistently showed complete or near complete bone and articular cartilage regeneration at 8 and 12 weeks whereas the grafts from the control groups had poor repair as judged by macroscopic, histologic, and immunohistologic criteria. This is the first report of articular cartilage regeneration using a combined gene therapy and tissue engineering approach.
TL;DR: Female athletes had a 25% greater risk of sustaining a Grade I ankle sprain compared with their male counterparts, and male and female athletes doubled their risk for sustaining an ankle injury at the intercollegiate level compared with the interscholastic level.
Abstract: The increased participation of women in organized athletics has resulted in an interest in gender-related injury patterns. Previous reports have indicated an increased incidence in anterior cruciate knee injuries among female intercollegiate basketball players compared with their male counterparts. The current epidemiologic study prospectively evaluated the relative risk of ankle injuries in scholastic and collegiate basketball players during a 2-year period. Eleven thousand seven hundred eighty athletes participated in this study, 4940 females and 6840 males. There were 1052 ankle injuries. Overall, females had a 25% greater risk of sustaining a Grade I ankle sprain compared with their male counterparts. This increased risk was present in the interscholastic and intercollegiate players. There was no significant difference in the risk for Grades II and III ankle sprains, ankle fractures, or syndesmotic sprains. Male and female athletes doubled their risk for sustaining an ankle injury at the intercollegiate level compared with the interscholastic level.
TL;DR: From 1986 to 1994, 112 bone allograft reconstructions were performed in patients with high-grade osteosarcoma in whom neoadjuvant chemotherapy was administered, finding that the incidence of delayed union, but not infection or fracture, was increased by the use of chemotherapy.
Abstract: From 1986 to 1994, 112 bone allograft reconstructions were performed in patients with high-grade osteosarcoma in whom neoadjuvant chemotherapy was administered. The allograft reconstruction was used in arthrodesis in 44 cases (41 knees, three ankles), as an intercalary graft in 39 (28 femurs, 11 tibias), as an osteoarticular graft in 22 (three proximal and/or distal humeri, six distal femurs, 13 proximal tibias), and as an allograft and prosthesis composite in seven (two proximal humeri, one proximal femurs, four proximal tibias). In 20 patients an autologous vascularized fibula was used to augment the allograft. Functional results were excellent or good in 74% of the patients after the primary surgery, and in 83% of the patients after secondary surgery. Complications include delayed union (49%) and fracture (27%), although there were no cases of deep infection. The incidence of delayed union, but not infection or fracture, was increased by the use of chemotherapy.
TL;DR: The results suggest that the pain relief and improvement in function reported by patients with osteoarthritis while using lateral-wedged insoles may be achieved by a reduction in external varus moment and medial compartment load.
Abstract: Lateral-wedged insoles have been shown to help clinically alleviate pain associated with medial compartment osteoarthritis. This study analyzed the effects of lateral-wedged insoles on the gait and medial knee compartment load of 17 healthy subjects. Three-dimensional gait analysis was performed for each subject with and without wearing a 5 degrees lateral-wedged insole. Subjects walked at a constant velocity for both conditions. A motion analysis system and force plate were used to calculate temporal and spatial parameters, joint angles, moments, and powers. An analytical model was developed to estimate medial compartment loads at the knee for each subject during both conditions. Results were compared with a Student's paired t test. There were no significant differences in temporal and spatial parameters, joint angles at the hip, knee, and ankle, or kinetics at the hip and ankle. However, the external varus moment and estimated medial compartment load at the knee were reduced significantly with the addition of the lateral-wedged insole. These results suggest that the pain relief and improvement in function reported by patients with osteoarthritis while using lateral-wedged insoles may be achieved by a reduction in external varus moment and medial compartment load.
TL;DR: There is wide variability in the duration of parenteral antibiotic therapy, and there essentially are no data on the use of bone graft in association with direct exchange, so the indications for direct exchange are limited.
Abstract: A literature review was performed to determine when direct exchange was most likely to be successful Twelve reports provided outcome data on infected hip replacements treated with direct exchange The average duration of followup was 48 years, but the range was broad (01-171 years) Of the 1,299 infected hip replacements treated with direct exchange, 1,077 (83%) were thought to be free of infection at the last followup Antibiotic-impregnated bone cement was used in 1,282 of the cases (99%) There was wide variability in the duration of parenteral antibiotic therapy, ranging from just 24 hours to as many as 8 weeks In some cases, no oral antibiotics ever were given, whereas in others, oral antibiotics were given for as many as 8 months after parenteral therapy Factors associated with a successful direct exchange included: (1) absence of wound complications after the initial total hip replacement; (2) good general health of the patient; (3) methicillin-sensitive Staphylococcus epidermidis, Staphylococcus aureus, and Streptococcus species; and (4) an organism that was sensitive to the antibiotic mixed into the bone cement Factors associated with failure included: (1) polymicrobial infection; (2) gram-negative organisms, especially Pseudomonas species; and (3) certain gram-positive organisms such as methicillin-resistant Staphylococcus epidermidis and Group D Streptococcus Methicillin-resistant organisms have become more common Many current revision surgical techniques use cementless implants Fixation without any cement (no depot antibiotics) may be a contraindication to direct exchange Additionally, there essentially are no data on the use of bone graft in association with direct exchange For these reasons, the indications for direct exchange are limited
TL;DR: This study indicated that acetabular allograft reconstructions reinforced by the Kerboull acetabULAR device were able to provide satisfactory long-term clinical and radiologic results.
Abstract: Sixty consecutive revision total hip arthroplasties were performed with bulk allograft bone supported by the Kerboull reinforcement acetabular device in 53 patients from 1980 to 1987. The average age of the patients at the time of hip revision was 57.7 years. Acetabular bone loss according to the American Academy of Orthopaedic Surgeons grading system was Type III for 48 hips in 41 patients and Type IV for 12 hips in 12 patients. Three failures, defined as radiologic loosening of the socket, revised or not, were reported in this series at a mean 8-year followup. Eight patients died of unrelated causes at a mean of 5 years. No patient was lost to followup. The mean followup of the series was 10 years +/- 3 years. The mean preoperative Merle d'Aubigne hip functional score was 11.7 +/- 2.4 versus 17.4 +/- 0.6 at the latest followup. Consolidation of the graft was considered completed in all 60 hips and occurred by 12 months. Remodeling of the graft proceeded for 3 to 4 years. The survival rate at 13 years was 92.1% +/- 5% using loosening of the acetabular component as the end point. This study indicated that acetabular allograft reconstructions reinforced by the Kerboull acetabular device were able to provide satisfactory long-term clinical and radiologic results.
TL;DR: Using measurements calculated from preoperative and intraoperative imaging, the approximate position of the nerve could be determined to better plan fixation method and implant location.
Abstract: Because the axillary and radial nerves can be injured during operative exposure and fixation of the humerus, accurate delineation of their location is vital to avoid complications. The authors investigated the relationship of the radial and axillary nerves for radiographically and surgically identifiable bony landmarks. Fifty fresh human cadaveric upper extremities were dissected to identify the nerves as they crossed the lateral intermuscular septum and the humeral surgical neck, respectively. Longitudinal distances between the nerves and the superior aspect of the humeral head, the surgical neck, the superior extent of the olecranon fossa, and the distal aspect of the trochlea were measured with calipers. The average distance from the axillary nerve to the proximal humerus was 6.1 +/- 0.7 cm (range, 4.5-6.9 cm) and 1.7 +/- 0.8 cm (range, 0.7-4.0 cm) from the surgical neck. The radial nerve traversed the lateral intermuscular septum 17 +/- 2.3 cm (range, 13-22 cm) from the proximal humerus, 12 +/- 2.3 cm (range, 7.4-16.6 cm) from the olecranon fossa, and 16 +/- 0.4 cm (range, 9.0-20.5 cm) from the distal humerus, representing the approximate midpoint of the bone. Anteroposterior locking screws placed into the proximal humerus endanger the axillary nerve because it lies directly over the posterior cortex as little as 0.7 cm from the surgical neck. As the radial nerve crosses the lateral intermuscular septum more proximal than generally was thought, it is at risk during implant insertion in the distal half of the humerus. Using measurements calculated from preoperative and intraoperative imaging, the approximate position of the nerve could be determined to better plan fixation method and implant location.
TL;DR: It is shown that human fracture hematoma contains the angiogenic cytokine vascular endothelial growth factor and has the inherent capability to induce angiogenesis and thus promote revascularization during bone repair.
Abstract: This study attempts to explain the cellular events characterizing the changes seen in the medullary callus adjacent to the interfragmentary hematoma during the early stages of fracture healing. It also shows that human fracture hematoma contains the angiogenic cytokine vascular endothelial growth factor and has the inherent capability to induce angiogenesis and thus promote revascularization during bone repair. Patients undergoing emergency surgery for isolated bony injury were studied. Raised circulating levels of vascular endothelial growth factor were seen in all injured patients, whereas the fracture hematoma contained significantly higher levels of vascular endothelial growth factor than did plasma from these injured patients. However, incubation of endothelial cells in fracture hematoma supernatant significantly inhibited the in vitro angiogenic parameters of endothelial cell proliferation and microtubule formation. These phenomena are dependent on a local biochemical milieu that does not support cytokinesis. The hematoma potassium concentration is cytotoxic to endothelial cells and osteoblasts. Subcutaneous transplantation of the fracture hematoma into a murine wound model resulted in new blood vessel formation after hematoma resorption. This angiogenic effect is mediated by the significant concentrations of vascular endothelial growth factor found in the hematoma. This study identifies an angiogenic cytokine involved in human fracture healing and shows that fracture hematoma is inherently angiogenic. The differences between the in vitro and in vivo findings may explain the phenomenon of interfragmentary hematoma organization and resorption that precedes fracture revascularization.
TL;DR: The data suggest that the disease modifying effect (the ability to retard progression of cartilage degeneration) of a mixture of glucosamine, chondroitin sulfate, and manganese ascorbate is more efficacious than either agent alone.
Abstract: Supplements of glucosamine hydrochloride, low molecular weight chondroitin sulfate, and manganese ascorbate were tested separately and in combination for their ability to retard progression of cartilage degeneration in a rabbit instability model of osteoarthrosis. Computerized quantitative histologic evaluation of safranin O stained sections of the medial femoral condyles measured the grade and extent of tissue involvement of lesions. Severe lesions (Mankin grade greater than 7) were absent in all animals supplemented with a dietary mixture of glucosamine, chondroitin sulfate, and manganese ascorbate. Total linear involvement (mm of lesioned surface) and total grade (mean grade x number of lesions per animal) were reduced significantly in animals given the combination compared with controls (59% and 74% respectively). Animals supplemented with glucosamine, chondroitin sulfate, or manganese ascorbate alone had less moderate and severe tissue involvement than controls but not to the extent of the combined group. In vitro, a combination of glucosamine hydrochloride and chondroitin sulfate acted synergistically in stimulating glycosaminoglycan synthesis (96.6%). Chondroitin sulfate and manganese ascorbate but not glucosamine were effective in inhibiting degradative enzyme activity. These data suggest that the disease modifying effect (the ability to retard progression of cartilage degeneration) of a mixture of glucosamine, chondroitin sulfate, and manganese ascorbate is more efficacious than either agent alone.
TL;DR: Markers of thrombin generation and fibrinolysis showed a significant increase from baseline in all the patients, and in Group II these markers started to increase during surgery, whereas in Group I the increase occurred at the end of the procedure when the tourniquet was deflated.
Abstract: Total knee replacement often is performed with tourniquet application. The advantages of a dry field, including fixation, are well known, but it still is debatable if tourniquet application increases deep vein thrombosis. Measurement of coagulation markers is a well accepted method of studying thrombogenesis activation intraoperatively and postoperatively. Twenty patients undergoing total knee replacement with subarachnoid anesthesia were assigned randomly to two groups: either with tourniquet application (Group I) or without tourniquet application (Group II). There were no differences between patients in the two groups in terms of age, gender, diagnosis (all had osteoarthritis), operative time, and total (intraoperative and postoperative) blood loss. Markers for thrombin generation and fibrinolysis were measured. Blood samples were drawn at four times: baseline before the operation; after bone cuts; after cement fixation (Group II) or 2 minutes after tourniquet deflation (Group I); and 1 hour after surgery. Markers of thrombin generation and fibrinolysis showed a significant increase from baseline in all the patients. In Group II these markers started to increase during surgery, whereas in Group I the increase occurred at the end of the procedure when the tourniquet was deflated. The total amount of thrombin generation was significantly higher in Group II (without tourniquet), whereas fibrinolysis was significantly greater in Group I. Total knee replacement is accompanied by a hypercoagulative state with or without the use of a tourniquet, but it seems to be higher when the tourniquet is not used. In addition, tourniquet application may increase fibrinolysis.
TL;DR: Function of the anterior and posterior oblique portions of the medial collateral ligament and the posterior capsule in flexion and extension was evaluated in eight knee specimens after posterior cruciate retaining total knee arthroplasty and increased laxity significantly in both groups in flexION and extension.
Abstract: Function of the anterior and posterior oblique portions of the medial collateral ligament and the posterior capsule in flexion and extension was evaluated in eight knee specimens after posterior cruciate retaining total knee arthroplasty. The posterior oblique portion of the medial collateral ligament was released subperiosteally in four specimens, and the anterior portion was released in four specimens. The medial posterior capsule was released in each group, then the remaining portion of the medial collateral ligament was released. Release of the posterior oblique portion produced moderate laxity at full extension and at 30 degrees flexion, and posterior capsule release produced additional laxity in full extension. Release of the anterior portion produced major laxity at 60 degrees and 90 degrees flexion. Complete medial collateral ligament release increased laxity significantly in both groups in flexion and extension. This rationale was tested in a clinical study of 82 knees (76 patients) in which 62 (76%) required medial collateral ligament release to correct varus deformity during posterior cruciate retaining total knee arthroplasty. Twenty-two knees (35.5%) were tight medially in extension only, and were corrected by releasing the posterior oblique portion. Thirty-one knees (50%) were tight medially in flexion only, and were corrected by releasing the anterior portion. Nine knees (14.5%) were tight medially in flexion and extension and required complete medial collateral ligament release, but three knees (4.8%) remained tight in extension and required medial posterior capsule release to correct flexion contracture and medial ligament contracture. Seventeen (27%) had partial posterior cruciate ligament release to correct excessive rollback of the femoral component on the tibial surface.
TL;DR: A literature review combined with the current series confirms that the principles of early reduction of hip dislocation, early stabilization, anatomic reduction of the fracture, and rigid fixation are critical principles to attain good results.
Abstract: Fracture of the femoral head after hip dislocation is a relatively rare injury often associated with a poor functional outcome. Twenty-six patients who sustained femoral head fractures were evaluated using radiographs, clinical examinations, and a validated outcome scoring system. The Short Form-12 was used to assess functional outcome. Patients whose fractures were stabilized with 3-mm cannulated screws and washers had a poor functional outcome. When evaluated with an odds ratio analysis, the use of Kocher-Langenbeck posterior approach was associated with a 3.2 times higher incidence of the patients having avascular necrosis develop when compared with the Smith-Petersen approach. A literature review combined with the current series confirms that the principles of early reduction of hip dislocation, early stabilization, anatomic reduction of the fracture, and rigid fixation are critical principles to attain good results. The Brumback classification system provides superior differentiation of different fracture types when compared with the Pipkin classification. The Smith-Petersen anterior surgical approach is recommended for the majority of patients with femoral head fractures. Three-millimeter cannulated screws with threaded washers are contraindicated for use in stabilizing femoral head fractures, and should not be used in any joint because of dissociation between the screw and the washer.
TL;DR: Postural and sociologic factors such as wearing high heels and sitting with legs adducted can influence the incidence and severity of anterior knee pain in women.
Abstract: There are clear differences between men and women regarding anterior knee pain Anatomic factors including increased pelvic width and resulting excessive lateral thrust on the patella are primary factors that predispose females to anterior knee pain Effects of estrogen on connective tissue synthesis have been reported, but there is no clear mechanism by which this would affect anterior knee pain Postural and sociologic factors such as wearing high heels and sitting with legs adducted can influence the incidence and severity of anterior knee pain in women
TL;DR: To elucidate the thermokinetic properties of collagen, punch biopsies of bovine joint capsule were immersed in a heated saline bath at temperatures between 20° and 90°C for periods up to 60 minutes and thermal shrinkage was measured by the change in the cross-sectional area.
Abstract: Thermal shrinkage of collagen currently is being used in orthopaedic surgery to treat ligamentous laxity. Understanding the kinetics of collagen shrinkage is key to revealing the events that take place during application of thermal energy. To elucidate the thermokinetic properties of collagen, punch biopsies of bovine joint capsule were immersed in a heated saline bath at temperatures between 20° and 90°C for periods up to 60 minutes. The resulting tissue thermal shrinkage was measured by the change in the cross-sectional area of the specimens. Only a small amount of shrinkage occurred at temperatures below 63°C, and increasing amounts and rates of shrinkage were seen at temperatures between 63° and 72°C. The denaturation kinetics of bovine knee collagen, which could be described by a first order reaction rate, had an activation energy of 2.3 × 10 5 kJ/mol.