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Biomedical subjects

David G Lewallen

Publications and source records attributed to David G Lewallen.

At least 37 records · Page 2Linked to original sources
PubMed2004

Modular porous metal augments for treatment of severe acetabular bone loss during revision hip arthroplasty.

Modular acetabular augments were implanted in 16 patients (16 hips) for support of an uncemented hemispheric acetabular component during revision acetabular reconstruction. Based on the classification of Paprosky, acetabular bone defects were classified as 2A in one hip, 2B in three hips, 2C in one hip, 3A in five hips, and 3B in six hips. Preoperatively, the prosthetic femoral head centers were located at a mean horizontal distance of 18.6 mm (range, -3-46 mm), and a mean vertical distance of 27.6 mm (range, -16-52 mm) from the approximate femoral head center. Postoperatively, the prosthetic femoral head centers were located at a mean horizontal distance of 10.4 mm (range, 1-25 mm), and a mean vertical distance of 7.4 mm (range, -15-25 mm). At final followup, no implant had evidence of migration or loosening. At early clinical followup, this modular acetabular augment system seems helpful in acetabular reconstructions that cannot be treated with an uncemented hemispheric cup that would have required other forms of treatment such as structural allografts, acetabular cages, bilobed acetabular components, or custom acetabular components. Longer term followup is required to determine whether there are untoward effects of using a modular acetabular reconstructive system.

Acetabulum↗
PubMed2004

Use of a constrained tripolar acetabular liner to treat intraoperative instability and postoperative dislocation after total hip arthroplasty: a review of our experience.

Constrained acetabular components have been used to treat certain cases of intraoperative instability and postoperative dislocation after total hip arthroplasty. We report our experience with a tripolar constrained component used in these situations since 1988. The outcomes of the cases where this component was used were analyzed for component failure, component loosening, and osteolysis. At average 10-year followup, for cases treated for intraoperative instability (2 cases) or postoperative dislocation (4 cases), the component failure rate was 6% (6 of 101 hips in 5 patients). For cases where the constrained liner was cemented into a fixed cementless acetabular shell, the failure rate was 7% (2 of 31 hips in 2 patients) at 3.9-year average followup. Use of a constrained liner was not associated with an increased osteolysis or aseptic loosening rate. This tripolar constrained acetabular liner provided total hip arthroplasty construct stability in most cases in which it was used for intraoperative instability or postoperative dislocation.

Adult↗
PubMed2004

Thirty-day mortality following hip arthroplasty for acute fracture.

BACKGROUND: Hip fractures are associated with a substantial mortality rate. Previous reports on perioperative mortality associated with hip arthroplasty for the treatment of acute fracture have not documented demographic and surgical characteristics that increase the likelihood of death. The purpose of the present study was to determine the prevalence of, and associated risk factors for, perioperative death following hip arthroplasty for the treatment of acute fracture. METHODS: Data were compiled from the computerized total joint registry at a single institution to determine the mortality rate following hip arthroplasty according to age, gender, diagnosis, implant type, and fixation mode. A review of this database revealed that 7774 consecutive patients had undergone hip arthroplasty for the treatment of an acute fracture between 1969 and 1997. The medical records of all patients who had died within thirty days after hip arthroplasty were reviewed retrospectively. RESULTS: The overall mortality rate within thirty days after hip arthroplasty for the treatment of an acute fracture was 2.4% (186 of 7774), yet notable variations in the mortality rate were seen within clinical subgroups. The thirty-day mortality rate was significantly higher for patients who had received a cemented implant, female patients, elderly patients, patients with cardiorespiratory comorbidities, and patients with intertrochanteric fractures. With the numbers available, there was no significant difference in mortality between patients who had been managed with total hip arthroplasty and those who had been managed with hemiarthroplasty. CONCLUSIONS: Hip arthroplasty for the diagnosis of acute fracture is associated with a nearly tenfold higher rate of perioperative mortality compared with elective hip arthroplasty. Medical optimization, appropriate choice of implants, and vigilant intraoperative management of these patients are essential.

Acute Disease↗
PubMed2004

A constrained liner cemented into a secure cementless acetabular shell.

BACKGROUND: Constrained acetabular components have been used to treat hips with recurrent instability following total hip arthroplasty and hips that demonstrate instability during revision surgery. In such hips, when a secure cementless acetabular shell is present, the surgeon can cement a constrained liner into the existing shell. The purpose of this study was to evaluate the clinical and radiographic outcome of this technique with use of a tripolar constrained liner that was cemented into a well-fixed cementless acetabular shell. METHODS: Between 1988 and 2000, constrained liners were cemented into thirty-one well-fixed cementless acetabular shells at three centers. The average age of the patients at the time of the index surgery was 72.1 years, and the indications for the procedure were recurrent hip instability in sixteen hips and intraoperative instability in fifteen hips. The patients were evaluated with respect to the clinical outcome and radiographic evidence of shell loosening and osteolysis. RESULTS: At an average duration of follow-up of 3.9 years, twenty-nine liners (94%) were securely fixed in the cementless shells and two constrained liners had failed. One liner failed because it separated from the cement, and one failed because of fracture of the capturing mechanism. Both hips were successfully revised with another cemented tripolar constrained liner. No acetabular component demonstrated radiographic evidence of progressive loosening or osteolysis. CONCLUSIONS: A constrained tripolar liner cemented into a secure, well-positioned cementless acetabular shell provides stability and durability at short-term follow-up. Careful attention to the preparation of the liner, the sizing of the component, and the cementing technique are likely to reduce the failure of this construct, which can be used for difficult cases of total hip instability.

Acetabulum↗
PubMed2004

Understanding osteoarthritis of the knee--causes and effects.

Osteoarthritis of the knee is common, increasing with age in both women and men, but is generally more prevalent in women following the fourth decade. Osteoarthritis may be primary/idiopathic or secondary as a consequence of trauma, surgery, infection, or another disease process. Normal articular cartilage is composed of an extracellular matrix and chondrocytes. This matrix contains water, collagen fibers, and proteoglycan macromolecules cross-linked into an integrated network with hyaluronic acid. Osteoarthritis represents an imbalance in the destructive and synthetic processes of the cartilage that leads to erosion of the cartilage. In addition, there is a decreased concentration and viscosity of the synovial fluid in osteoarthritic patients, and this may decrease the lubricating and cushioning properties of the joint. There is also an underlying inflammation of the synovium, as well as damage or reactive changes in the subchondral bone. The entire process is thought to involve a complex interaction of cells and soluble mediators such as cytokines, growth factors, inflammatory mediators, metalloproteinases, and chondrodegradative enzymes. Understanding the biochemical and molecular changes that occur in the joint is requisite to the development of treatments for osteoarthritis of the knee that address both the symptoms of pain and loss of mobility as well as the underlying disease progression. The clinical goal of the management of osteoarthritis should be to treat not only the symptoms of the disease, such as pain and decreased mobility, but also the underlying pathology of the degenerative process.

Cartilage, Articular↗
PubMed2004

Nonsurgical approaches to pain management for osteoarthritis of the knee.

The effective management of pain in osteoarthritis of the knee is complex and subject to many treatment- and patient-related variables. This article reviews the broad range of nonsurgical options available to the clinician, which include pharmacologic and nonpharmacologic measures such as weight loss, physical and occupational therapy, exercises, and the use of assistive devices. Pharmacotherapeutic options for osteoarthritis of the knee include the use of oral agents, topical creams, and intra-articular injections of hyaluronans or glucocorticoids. Since pain in the osteoarthritic knee can vary widely from patient to patient in its origins, pain management should address the individual patient's symptoms, level of pain, and functional disabilities.

Humans↗
PubMed2004

Surgeons rarely discuss sexual activity with patients after THA: a survey of members of the American Association of Hip and Knee Surgeons.

A survey of members of the American Association of Hip and Knee Surgeons was done to document surgeons' attitudes and practices regarding discussion of return to sexual activity, timing of return, and safety of various sexual positions for patients after total hip arthroplasty. Surveys were returned by 254 of 821 surgeons (31%). Two hundred thirty-three (80%) surgeons reported they rarely or never discuss sexual activity with their patients who have had hip arthroplasty. Of surgeons who stated they did discuss this topic, 96% spent 5 minutes or less. Most respondents (67%) recommended delaying return to sexual activity until 1-3 months postoperatively. Fifty-one respondents (20%) reported knowledge of patients experiencing dislocation of the total hip replacement during sexual activity. Five specific sexual positions for men and three positions for women were considered acceptable by more than 90% of respondents. Most agreed that sexual activity could be resumed safely 1-3 months postoperatively if acceptable positions were used.

Arthroplasty, Replacement, Hip↗
PubMed2003

Cementation of an acetabular liner into a well-fixed acetabular shell during revision total hip arthroplasty.

Cementing a polyethylene liner into a well-fixed acetabular shell during revision hip arthroplasty may be appropriate in select patients. The purpose of this study was to review our early results with this technique. Sixteen patients with >2-year follow-up or who had any complications at <2 years from surgery were identified. Indications for this technique included: failure of the previous locking mechanism, significant polyethylene wear, malposition of the well-fixed metal shell, and previous removal of the liner with a retained acetabular shell. One acetabular shell has been revised at 13 months for multiple dislocations. Hip scores improved an average of 24.2 points. Radiographs revealed no polyethylene dissociation or acetabular loosening. Complications occurred in 7 patients. Initial results appear successful at providing secure fixation, while preventing the bone loss that might occur with removal of a well-fixed component.

Aged↗
PubMed2003

Total knee arthroplasty in post-traumatic arthrosis of the knee.

Total knee arthroplasty is an effective method of treatment for the majority of patients with a prior distal femoral or tibial plateau fracture and end-stage arthritis. There is a higher complication rate and overall poorer outcome when compared with routine primary total knee arthroplasty. In patients for whom the goals of optimal limb and implant alignment are achieved, the results are comparable with routine primary knee arthroplasty. Patients with suboptimal component positioning or residual deformity have a poorer outcome. The technical challenges encountered can require skills, implant systems, and methods usually reserved for complex revision arthroplasty.

Arthritis↗
PubMed2003

Total knee arthroplasty in patients with a prior fracture of the tibial plateau.

BACKGROUND: A fracture of the tibial plateau may predispose the knee to the development of posttraumatic arthritis. Malunion, intra-articular chondro-osseous defects, limb malalignment, retained internal fixation devices, and poor surrounding soft tissues may in turn compromise the outcome of total knee arthroplasty. The aim of our study was to evaluate the results of total knee arthroplasty in patients with a previous fracture of the tibial plateau. METHODS: The results of sixty-two condylar total knee arthroplasties performed with cement, from 1988 to 1999, in sixty-two patients with a previous fracture of the tibial plateau were reviewed. The fracture of the tibial plateau had been treated by open reduction and internal fixation in thirty-eight knees, external fixation in one knee, and nonoperatively in twenty-three knees. There were forty women and twenty-two men with an average age of sixty-three years at the time of the arthroplasty. Knee Society scores were recorded preoperatively and at the time of follow-up, at an average of 4.7 years, and complications were noted. No patient was lost to follow-up. RESULTS: The mean Knee Society scores improved significantly (p < 0.0001), from 43.9 points for pain and 52 points for function preoperatively to 82.9 and 84 points, respectively, at the time of the latest follow-up. There were thirteen reoperations, which included manipulation with the patient under anesthesia (five knees), wound revision (three knees), and component revision (five knees). There were six intraoperative complications (10%). A postoperative complication occurred in sixteen knees (26%). CONCLUSIONS: The vast majority of patients treated with total knee arthroplasty after a previous fracture of the tibial plateau have substantial improvement in function and relief of pain. However, these patients are at increased risk for perioperative complications, as evidenced by the high reoperation rate of 21% in this study.

Adult↗
PubMed2003

Treatment of periprosthetic femoral fractures following total hip arthroplasty with femoral component revision.

BACKGROUND: Revision total hip arthroplasty is indicated for most periprosthetic fractures that occur around the stem of the femoral implant. The purpose of the present study was to assess the results and complications of revision total hip arthroplasty for the treatment of periprosthetic femoral fractures. METHODS: We evaluated 118 hips in 116 patients who underwent revision total hip arthroplasty because of an acute Vancouver type-B periprosthetic femoral fracture. The femoral implant used for the revision was a cemented stem in forty-two hips, a proximally porous-coated uncemented stem in twenty-eight, an extensively porous-coated stem in thirty, and an allograft-prosthesis composite or tumor prosthesis in eighteen. The mean duration of follow-up was 5.4 years. RESULTS: Kaplan-Meier analysis demonstrated that the probability of survival was 90% at five years and 79.2% at ten years with revision or removal of the femoral implant for any reason as the end point. Sixteen femoral components were rerevised: ten were rerevised because of loosening; three, because of loosening in association with a fracture nonunion; two, because of recurrent dislocation; and one, because of a new periprosthetic fracture. Additionally, six femoral implants were resected because of deep infection (five) or prosthetic loosening (one). Radiographs of the ninety-six hips with a surviving implant showed that twenty-one had evidence of loosening of the femoral implant, four had a nonunion of the femoral fracture, and two had both a nonunion and loosening of the femoral implant. CONCLUSIONS: Revision total hip arthroplasty for the treatment of a periprosthetic fracture around the stem of the femoral implant successfully restored function for most patients. The greatest long-term problems were prosthetic loosening and fracture nonunion. Better results were seen when an uncemented, extensively porous-coated stem was used.

Adult↗
PubMed2003

The use of a constrained acetabular component to treat instability after total hip arthroplasty.

BACKGROUND: Recurrent dislocation after total hip arthroplasty is a disabling complication that can be difficult to treat and may not be amenable to nonoperative management. The purpose of the present study was to evaluate the clinical and radiographic outcome associated with the use of a constrained acetabular component as a salvage treatment for instability after hip arthroplasty. METHODS: We retrospectively reviewed the clinical and radiographic outcome of 110 arthroplasties, in 109 patients, that had been performed with use of a single design of constrained acetabular component. In seventy-nine hips the constrained component was implanted for the treatment of recurrent instability, and in thirty-one hips it was implanted because of absent or grossly deficient soft-tissue attachments that were believed to be associated with a high risk for subsequent instability. RESULTS: The constrained acetabular device eliminated or prevented hip instability in all patients except two, who continued to have sensations of subluxation. The mean Harris hip score improved significantly, from 62.7 points preoperatively to 76.4 points at the time of the latest follow-up (p < 0.0001). There were no instances of dislocation or disassembly of the hip components. Radiographic analysis revealed radiolucent lines around the cup in fifteen hips (14%). There was a total of nine revisions: six for deep infection, two for acetabular component loosening, and one for a periprosthetic fracture of the femur. CONCLUSIONS: A constrained acetabular component reliably restores and maintains hip stability in patients with recalcitrant recurrent instability and can dependably prevent dislocation in those who are at high risk because of absent or deficient soft tissues about the hip. However, because of the early appearance of radiolucent lines around some components and concerns about long-term fixation, the use of these devices should be reserved for situations in which other methods are inadequate or have already failed.

Adult↗
PubMed2002

Total knee arthroplasty following prior distal femoral fracture.

BACKGROUND: Femoral fracture may predispose the knee to the development of post-traumatic arthritis by either a direct intra-articular injury or residual limb malalignment. Malunion, intra-articular osseous defects, limb malalignment, retained internal fixation devices, and compromised surrounding soft tissues may in turn affect the outcome of total knee arthroplasty (TKA) in these patients. The aim of our study was to evaluate the result of TKA in patients with previous distal femoral fracture. METHODS: The results of 48 cemented condylar total knee arthroplasties, performed between 1980 to 1998, in 47 patients with a previous distal femoral fracture were reviewed. There were 37 females and 10 males with an average age of 65 years (range, 19-84 years). Follow-up averaged 6.2 years (range, 2-16 years). No patients were lost to follow-up. RESULTS: At the time of arthroplasty a femoral fracture non-union was present in three knees, all of which were treated with a long stem cemented femoral component and bone grafting. Malunion, defined as angulation greater than 10 degrees in the coronal plain or greater than 15 degrees in the sagittal plain, was present in 21 knees. Of these, six underwent distal femoral osteotomy during TKA. In the remaining 15 patients, with a malunion, the deformity was addressed by alterations in the orientation and location of bone resection. Other procedures were commonly needed at the time of arthroplasty and included: lateral retinacular release (22 knees), extensor mechanism realignment (eight knees), and collateral ligament reconstruction (two knees). The mean pre-operative Knee Society Scores were 40 (range, 0-80) for pain and 48 (range, 0-100) for function and improved significantly to a mean of 84 (range, 37-99) and 66 (range, 0-100) points, respectively, at the latest follow-up (P<0.001). The knee arc of motion improved from a pre-operative mean of 83-99 degrees at the latest follow-up (P<0.004). Post-operative manipulation under anesthesia for poor motion was carried out in four knees. Two knees had aseptic loosening that required subsequent revisions. Three knees developed deep infection which was treated with debridement and retention of components in one knee, arthrodesis in another, and eventual amputation in one knee. CONCLUSIONS: Significant improvement in function and relief of pain is seen in the vast majority of patients with previous distal femoral fractures undergoing subsequent TKA. However, these patients are at increased risk for restricted motion and perioperative complications following TKA. Special efforts to preserve the vascularity of the skin and subcutaneous tissues, restore limb alignment, ensure correct component positioning, and achieve soft tissue balance may help minimize the problems identified in this study.

Adult↗
PubMed2002

Outcome of uncemented hip arthroplasty components in patients with Paget's disease.

The outcome of uncemented hip arthroplasty in patients with Paget's disease is unknown. The clinical and radiographic records of patients with Paget's disease affecting the hip who had total hip arthroplasty using uncemented components against pagetic bone were reviewed. There were 18 patients (19 hips) with an average age of 71.3 years (range, 54-85 years). Followup averaged 7 years (range, 2-15 years). Surgery often was reported to be demanding technically because of hard sclerotic bone and excessive bleeding in some patients. Estimated blood loss averaged 996 mL (range, 200-2500 mL). Harris hip scores improved significantly. There was clinical and radiographic evidence of bone ingrowth in all patients. Six of 19 hips had heterotopic bone. One hip had severe Brooker Grade IV heterotopic ossification and the patient required excision of the ossification at 5 years. One hip was unstable (subluxating) at the latest followup. There was no revision for component loosening and no recognized cases of clinical or radiographic loosening of any uncemented implants. Results of total hip arthroplasty using uncemented components in patients with Paget's disease are excellent overall, with an extremely low risk of component loosening during the first decade after implantation. These patients may be at higher risk for heterotopic bone formation and increased perioperative blood loss because of hypervascularity of the bone.

Aged↗
PubMed2002

Total knee arthroplasty in limbs affected by poliomyelitis.

BACKGROUND: Little information is available regarding the results and complications of total knee arthroplasty in limbs affected by poliomyelitis with severe knee degeneration. METHODS: We performed a retrospective chart and radiograph review of patients with a history of poliomyelitis involving a limb that subsequently underwent primary total knee arthroplasty between 1970 and 2000. Sixteen total knee arthroplasties were performed in limbs affected by poliomyelitis in fifteen patients. Eleven patients were followed for a minimum of two years, one (two knees) died before the minimum two-year follow-up could be completed, and three were followed for less than two years. No patient was lost to follow-up. RESULTS: There were two periprosthetic fractures, one peroneal nerve palsy, one avulsion of the patellar tendon, and four cases of recurrent instability. These complications were related to the poor bone quality, valgus deformity, patella baja, poor musculature, and attenuated soft tissues commonly found in knees affected by poliomyelitis. Knee Society pain and knee scores were improved postoperatively for all nine knees with a two-year follow-up that had had at least antigravity quadriceps strength prior to surgery. However, Knee Society function scores remained at 0 or worsened for six of the eleven knees followed for at least two years, including those with less than antigravity strength, and four of the nine knees with at least antigravity strength. None of the prostheses loosened. CONCLUSIONS: Pain and knee scores improved following total knee arthroplasty in patients with a history of poliomyelitis and antigravity quadriceps strength, but there was less pain relief in patients with less than antigravity quadriceps strength. Recurrence of instability and progressive functional deterioration is possible in all knees affected by poliomyelitis that have undergone total knee replacement, but they appear to occur more commonly in more severely affected knees.

Aged↗