Biomedical subjects

R J Haddad

Publications and source records attributed to R J Haddad.

At least 19 recordsLinked to original sources

PubMed1991

Tissue growth into porous primary and revision femoral stems.

The authors studied 45 uncemented porous-coated femoral stems from 45 patients: 35 primary total hip arthroplasties and 10 revisions of either cemented (7) or uncemented (3) femoral components. Histologic sections were examined quantitatively for type, amount, and distribution of tissue ingrowth; these findings were correlated with clinical and radiographic data. Fibrous tissue ingrowth predominated in both groups. Of the primary arthroplasty group, the grade of bone ingrowth in 8 specimens was none, 14 minimal, 6 moderate, and 7 more extensive. In the revision cases, the grade of bone ingrowth in 5 was none, 3 minimal, and 2 moderate. Bone ingrowth was seen more frequently in the distal porous coating, particularly in the revision cases, and most often where direct stem-endosteal canal contact had occurred. While bone ingrowth can occur in uncemented revision stems, it generally appears less abundantly than in primary total hip arthroplasty.

Adult↗

PubMed1991

Inflammatory response in retrieved noncemented porous-coated implants.

One hundred forty-six noncemented porous-coated hip and knee implants retrieved from 97 patients were evaluated histologically for the type, amount, and anatomic distribution of tissue ingrowth. The degree of inflammatory cell infiltrate present was also evaluated and the predominant cell type was identified. An inflammatory infiltrate was present in the components of 21 of 97 patients (22%). In 16 of the 21 cases the infiltrate was lymphocytes and histiocytes with a minor population of plasma cells. One of the remaining five cases had a predominately plasma cell reaction, and the other four had significant populations of plasma cells. Vascular proliferation was observed in nine of the 21 cases. Bone ingrowth was present in ten of the 21 cases. A 38% incidence of removal for persistent pain was present in cases with an inflammatory infiltrate. Seventeen of 87 patients (20%) with cobalt-chromium devices and four of ten patients (40%) with titanium devices were identified as having an inflammatory infiltrate. The origin of the inflammatory infiltrate is unclear. All patients with inflammatory infiltrates had noninfected implants, which were not loose roentgenographically or clinically at the time of removal. Hypersensitivity and allergic responses to metal ions may produce such infiltrates. It is impossible, however, in the present study to definitively determine the etiology of the infiltrates.

Adult↗

PubMed1990

A comparison of three varieties of noncemented porous-coated hip replacement.

We reviewed 134 primary noncemented porous-coated total hip replacements in 125 patients: 64 were DePuy AML prostheses, 20 were Howmedica PCA and 50 were Implant Technology LSF. The prostheses had been in situ for an average of 36 months, 40 months and 24 months respectively. The average pre-operative Harris hip scores were 38.2 for AML, 33.2 for PCA, and 41.0 for the LSF prostheses. The average postoperative scores were 80.7 for AML, 83.8 for the PCA, and 91.5 for LSF. Thigh or groin pain associated with the prosthesis was present in 30% of AML, 30% PCA and 8% of the LSF cases. The clinical and radiographic review showed better early results with the LSF prostheses than the others; this seemed to be related to the implant design, which provided improved initial stability and more physiological transfer of load.

Adult↗

PubMed1990

Four-year average follow up of cemented PCA total knees: clinical and roentgenographic analysis.

Twenty patients with 25 consecutive primary-cemented Howmedica PCA total knee prostheses were clinically and roentgenographically reviewed. Twenty implants were placed in 16 women and five in four men. The average patient age at surgery was 68.0 years (range, 53 to 82), and average follow up was 51 months. Total knee replacement indication was degenerative joint disease in 21 knees and rheumatoid arthritis in four. Excellent or good results were seen in 22 of 25 knees (88%) at the early follow up examination and 18 of 25 knees (72%) at the most recent follow up examination.

Aged↗

PubMed1990

Clinical and roentgenographic evaluation of bipolar prostheses with noncemented anatomic medullary locking femoral stems.

Fifty-six DePuy anatomic medullary locking femoral bipolar prostheses were reviewed clinically and roentgenographically in 50 patients at an average follow-up period of 30 months (range, 24-71 months). Forty-four of the implantations were in 40 male and 12 were in ten female patients. Forty-five devices were placed in primary operations, while 11 were used in revisions. The overall average age was 53.5 years. The average Harris hip scores for the primary bipolars were 29.8 preoperative and 77.3 postoperative, while the revision bipolars had Harris hip scores of 35.9 preoperative and 75.1 postoperative. Nearly one-half (47%) of all primary and 54% of the revision patients experienced pain to some degree on ambulation. Roentgenographically, all femoral components appeared to be well fixed biologically. Roentgenographic changes occurred with time in both primary and revision prostheses. On roentgenographic zonal analysis of primary prostheses, radiolucencies greater than 1 mm were present most frequently in the most proximal lateral zone and at the distal tip of the prosthesis. Although the use of noncemented bipolar prostheses generally shows acceptable clinical results, noncemented fixed acetabular components with noncemented femoral components produce a more satisfactory clinical result.

Adult↗

PubMed1990

Clinical and roentgenographic evaluation of noncemented porous-coated anatomic medullary locking (AML) and porous-coated anatomic (PCA) total hip arthroplasties.

Eighty-four primary noncemented porous-coated total hip arthroplasties (THAs) in 78 patients were reviewed clinically and roentgenographically at an average follow-up period of 37 months. The average patient age was 51.9 years. Sixty-four Anatomic Medullary Locking (AML) devices were placed in 58 patients, and 20 Porous-Coated Anatomic (PCA) devices were placed in 20 patients. The AML devices had been in situ an average of 36 months (range, 24-49 months), and the PCA devices had been in situ an average of 40 months (range, 29-51 months). The average patient ages were 52.7 and 49.2 years for AML and PCA patients, respectively. The AML devices included three that were fully coated, 59 that were five-eighths coated, and two that were one-third coated. The average preoperative Harris hip score was 38.2 for the AML devices and 33.2 for the PCA devices. The average postoperative Harris hip score was 80.7 for the AML devices and 83.8 for the PCA devices. Pain related to the implant was present in 30% of the AML devices and 30% of the PCA devices. Roentgenographically, no component demonstrated complete radiolucency, and all components demonstrated roentgenographic evidence of bone ingrowth. Roentgenographic changes with time noted for both the AML and PCA devices included: neck roundoff, neck osteolysis, neck corticocancellization, endosteal bone bridging, and distal hypertrophy. On roentgenographic zonal analysis, radiolucency greater than 1 mm was observed most frequently in the most proximal lateral zone and distal tip of the femoral component. The current series of cases, although clinically acceptable, does not support the current widespread enthusiasm for primary noncemented AML and PCA total hip systems. Cemented THA appears to produce superior clinical results, particularly when contemporary cementing techniques are employed.

Adult↗

PubMed1989

Quantitative histologic analysis of tissue growth into porous total knee components.

Histologic and radiographic analysis was performed on 85 porous-coated, uncemented knee components (26 femoral, 34 tibial, and 25 patellar) retrieved from 45 patients for malposition or instability, unexplained pain, late infection, postmortem or postamputation, and posttrauma. No component was clinically or radiographically loose at the time of removal. The average patient age at removal was 62.1 years (range, 39-85 years), and the average time in situ was 12.4 months (range, 2 weeks to 53 months). Radiographs from 31 of the 45 patients (69%) were examined for implant alignment, fit, subsidence, loose beads, and the presence of sclerotic and lucent lines. Histologic and microradiographic sections of the implant and adherent tissue were examined for type, amount, and anatomic location of tissue ingrowth. Overall, 52% of the components showed no evidence of bone ingrowth, 29% showed minimal (less than 2%), 12% showed moderate (2-5%), and 7% showed extensive (5-10%) bone ingrowth. In no case was bone present in more than 10% of the available pore volume of any component. There were no significant differences in the incidence or extent of bone ingrowth among femoral, tibial, and patellar components, nor in the extent of bone ingrowth observed in comparing different implant designs, materials, or porous coating types. When bone ingrowth was observed, the anatomic location was consistent in each type of component. The presence of a lucent line radiographically was indicative of fibrous encapsulation, while a sclerotic line or absence of any radiographic abnormality was seen with both fibrous tissue and bone ingrowth.

Aged↗

PubMed1989

Biologic response to hydroxylapatite-coated titanium hips. A preliminary study in dogs.

Hydroxylapatite (HA)-coated and uncoated Ti-6A1-4V alloy femoral endoprostheses were evaluated in adult dogs. The femoral stems had proximal anterior, posterior, and medial pockets of either a commercially pure titanium porous coating or a grooved macrotexture. They also had a medial collar, with an inferior surface pocket of either the porous coating or the grooved macrotexture. HA-coated and uncoated specimens of each type were evaluated. The devices were placed as unilateral hemiarthroplasties in 12 dogs and remained in function for up to 52 weeks. Histologic sections from the uncoated grooved implants showed no direct bone-implant apposition in the proximal regions after up to 10 weeks; the HA-coated grooved implants demonstrated extensive direct bone-coating apposition after 5 weeks. Sections from uncoated porous implants evaluated after 10 weeks demonstrated approximately equivalent in-growth to those sections from the HA-coated devices after 6 weeks. All HA-coated implants demonstrated consistent bone-implant apposition with no fibrous tissue interposition. The HA-coated surfaces were associated with increased bone deposition and proliferation at early implantation periods. In no histologic section examined was there any evidence of deterioration of the HA coating, nor was any separation of the coating from the substrate material observed.

Alloys↗

PubMed1989

Initial antibiotic therapy for alligator bites: characterization of the oral flora of Alligator mississippiensis.

An open thumb fracture resulting from an alligator bite became infected with Aeromonas hydrophila, Enterobacter agglomerans, and Citrobacter diversus. The patient was treated by surgical debridement and antibiotic therapy. We obtained cultures from the mouth of ten alligators to characterize their oral flora. Initial empiric therapy after alligator bites should be directed at gram-negative species, in particular, Aeromonas hydrophila and anaerobic species including Clostridium. Of the numerous fungi that were isolated, none has been reported to result in wound infection after alligator bites.

Adult↗

PubMed1988

The effect of post-sintering heat treatments on the fatigue properties of porous coated Ti-6Al-4V alloy.

Porous coated Ti-6Al-4V alloy implant systems provide a biocompatible interface between implant and bone, resulting in firm fixation and potential long-term retention via bony ingrowth. In order to achieve an acceptable porous coating structure, the sintering protocol for Ti-6Al-4V alloy systems often requires that the material be heat treated above the beta transus. This transforms the as-received equiaxed microstructure, recommended for surgical implants, to a lamellar alpha-beta distribution, which has been shown to have the worst fatigue properties of the most common structures attainable in Ti-6Al-4V alloy. However, post-sintering heat treatments may be used to improve these properties by producing microstructures more resistant to crack initiation and propagation. This study investigated the influence of microstructural variations on the fatigue properties of porous coated Ti-6Al-4V alloy material. Nonporous coated and porous coated Ti-6Al-4V alloy fatigue specimens were subjected to a standard sintering heat treatment to produce a lamellar microstructure. In addition, two post-sintering heat treatments were used to produce coarse and fine acicular microstructures. Rotating beam (reversed bending) fatigue testing was performed and the endurance limits determined for the noncoated and porous coated microstructures. The values determined were 668 MPa (noncoated as-received equiaxed), 394 MPa (noncoated lamellar), 488 MPa (non-coated coarse acicular), 494 MPa (noncoated fine acicular), 140 MPa (porous coated lamellar), 161 MPa (porous coated coarse acicular), and 162 MPa (porous coated fine acicular). The noncoated coarse and fine acicular specimens displayed an approximate 25% increase over the noncoated lamellar specimens. The porous coated coarse and fine acicular specimens showed an approximate 15% improvement over the porous coated lamellar specimens.

Alloys↗

PubMed1988

Comparative mechanical analysis of a looped-suture tendon repair.

The in vitro breaking force of a braided nylon looped-suture tendon juncture designed to decrease tying time was compared with the breaking force of the modified Kessler and Bunnell techniques. Repaired with either braided nylon or tetrafluoroethylene, porcine digiti quarti propius tendons were tested to single cycle failure on a MTS hydraulic testing machine. The results showed that the looped-suture technique had a mean breaking force that was statistically indistinguishable from that of the Bunnell technique regardless of suture material. However, the breaking forces for the looped suture and Bunnell techniques were statistically greater for both suture materials when compared with the modified Kessler technique. The resistance to gap formation for the looped suture was found to be intermediate between the Bunnell technique and the modified Kessler technique.

Animals↗

PubMed1988

Quantitative analysis of tissue growth into human porous total hip components.

Histologic and radiographic analysis was performed on 36 porous-coated total hip components (22 femoral and 14 acetabular) retrieved from 30 patients. The average patient age was 53.0 years (range, 28-78 years) for femoral components and 56.9 years (range, 28-78 years) for acetabular components. The average time in situ was 13.6 months (range, 2-36 months) for femoral components and 5.5 months (range, 1-18 months) for acetabular components. Fourteen implants were retrieved for instability or dislocation, 12 for late infection, and 8 for persistent pain, and 2 were retrieved after the patient died. Radiographs were reviewed for Singh index, heterotopic bone, implant fit, subsidence, and presence of lucent and sclerotic zones. Histologic and microradiographic sections of the implant and adherent tissue were examined for type, amount, and anatomic distribution of tissue ingrowth. Four femoral stems had no bone ingrowth, 10 had minimal bone growth into the available pore volume (less than 2%), 3 had moderate bone ingrowth (2-5%), and 5 had more extensive bone ingrowth (5-10%). Bone ingrowth tended to occur where the implant made direct contact with the endosteal cortical surface and was rarely seen in proximal metaphyseal bone. Bone ingrowth was completely absent in eight acetabular components, minimal (less than 2%) in three, moderate (2-5%) in two, and more extensive (5-10%) in one and tended to occur adjacent to fixation pegs, spikes, or screws. Radiographic or clinical findings were unreliable in predicting the presence or extent of bone ingrowth in either femoral or acetabular components.

Acetabulum↗

PubMed1988

Tissue reaction to implant corrosion in 38 internal fixation devices.

The corrosion characteristics, metallurgical properties, and clinical performance of 38 retrieved internal fixation devices were correlated with the tissue reaction to these devices. Metallurgical parameters included thin and heavy inclusion content, Rockwell hardness, and grain size. The excised fibrous tissue strip was directly overlying each plate at removal and sectioned between screw-hole sites. The material studied from the 38 plates consisted of 201 screw-hole junctions with associated tissue biopsy sites. Clinical histories were obtained on all 38 patients with hardware removal. The average age at the time of plate insertion was 35.6 years (range, 4 to 75 years). Insertion diagnoses included acute trauma (35 patients), joint dislocations (two patients), and fracture nonunion (one patient). The devices included seven upper extremity bone plates, 19 lower extremity bone plates, and 12 hip screw plates. The devices remained in situ an average of 20.4 months (range, 3 to 60 months). Routine asymptomatic removals were performed on 17 of the patients, while the remaining 21 patients were symptomatic at the time of removal. Included in the reasons for symptomatic removal were pain associated with the implant (eight patients), nonunion (four patients), bursae prominence (three patients), and implant breakage (two patients). Significant correlations were found between average tissue reaction scores and average crevice corrosion scores; a trend of increasing average tissue reaction scores with increasing average screw surface corrosion scores also was observed for the 38 devices, although this relationship was not significant. Average crevice corrosion scores and average screw surface corrosion scores were highly correlated for all removals, and for the asymptomatic and symptomatic removal groups. The metallurgical parameters of thin inclusion content and heavy inclusion content also were significantly correlated for all removals, as well as for symptomatic removals. Similarly, significant correlations were found between the individual tissue reaction scores and crevice corrosion scores from the 201 individual sites, again for all devices and for the asymptomatic and symptomatic removal groups. Tissue reaction scores and time in situ showed significant correlation, with tissue reaction decreasing over time. Crevice corrosion and screw surface corrosion scores were not significantly related to time in situ. The results of this study indicate that there is considerable tissue reaction to the corrosion products of this material.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1988

A chronically dislocating prosthetic patella. A case report.

A 63-year-old white woman was evaluated for a chronically dislocating right patella 6 months following total knee arthroplasty. At the time of our initial evaluation, her knee would not extend beyond 35 degrees and her patella was dislocated and irreducible. At arthrotomy, when the patella was everted, the patellar component was oriented with the facet ridge rotated 90 degrees to the trochlear groove of the femoral component. The patellar template guide indicated that the fixation pegs had been drilled properly, and thus, the patellar component had been assembled improperly during manufacturing. After dome-type patellar prosthesis replacement and proximal and distal extensor realignments were performed, 2 months post-revision the patient had a range of motion from 5 degrees to 95 degrees and ambulated with no patellar instability or pain.

Equipment Failure↗

PubMed1988

Hallux rigidus.

This article discusses the pathophysiology in the development of the hallux rigidus deformity. The clinical and radiographic findings are discussed and identified. Various modalities of conservative and surgical care are discussed.

Arthrodesis↗

PubMed1988

Histologic analysis of retrieved human porous-coated total joint components.

A histologic and microradiographic analysis was performed on 90 retrieved human noncemented porous-coated total joint implants recovered from 58 patients. The specimens included 62 total knee components from 34 patients and 28 total hip components from 24 patients. All components were inserted without the use of bone cement, and in no case was the retrieved component removed due to clinically or roentgenographically apparent loosening. Approximately 92% of the total knee components and 93% of the total hip components had been in situ at least six weeks; 70% of the knee components and more than 50% of the hip components had been functional for at least nine months. The histologic sections and microradiographs revealed varying amounts of bone growth into or in apposition to the porous coatings. In approximately one third of the components, no bone ingrowth or apposition was observed. No component had greater than 10% of the available porous material ingrown with bone. No relationship between the degree of bone ingrowth and the length of time in situ was noted. In all components, the majority of the porous coating contained fibrous tissue that in some cases displayed orientation indicating evidence of load transmission capability. The adherence of bony tissue at the time of removal, a positive roentgenographic evaluation, or a positive clinical presentation was not found to be a definite prognosticator of bone ingrowth. It appears that the combination of limited bone ingrowth and extensive fibrous tissue ingrowth is adequate for implant fixation.

Adult↗

PubMed1987

The in vivo performance of 250 internal fixation devices: a follow-up study.

The in vivo performance of 250 retrieved internal fixation plates was evaluated. The corrosion characteristics and metallurgical properties of each implant were assessed and correlated with respective clinical performance. Screw-plate interface corrosion and screw surface corrosion were graded; Rockwell hardness, grain size, thin inclusion content, and heavy inclusion content measurements were made. The devices studied included 169 bone plates, 59 Richards type hip screw-plates and 22 Jewett type hip nail-plates. The devices remained in situ for an average of 26.3 months, with in situ periods ranging from 1 to 192 months. The majority of the plates (50.4%) were removed due to cause-related reasons, while the remaining devices (49.6%) were removed on a routine asymptomatic basis. The primary symptomatic removal reasons consisted of implant related pain, nonunion or malunion, infection, loosening and implant breakage. Upon stereomicroscopic examination, 89% of all plates exhibited some degree of interface crevice corrosion, and 88% of all screws exhibited some degree of surface corrosion. Statistical analysis of corrosion gradings and metallurgical data revealed significant correlations between the two. As was suggested in our previous study of a limited number of implants, this study demonstrates that stricter manufacturing standards for metallurgical properties would serve to enhance corrosion resistance and improve the in vivo performance of stainless steel internal fixation devices. It is also suggested that the routine removal of all internal fixation plates after fracture healing has been achieved would reduce the occurrence of symptomatic complications, such as implant breakage, implant loosening and implant related pain.

Bone Plates↗

PubMed1987

Clinical performance of endoprosthetic and total hip replacement systems.

A retrospective study of endoprosthetic replacements and total hip prostheses was undertaken to determine factors that have the greatest effect on the success or failure of femoral hip components. A total of 227 endoprostheses were inserted within the years 1970-1985. Of these, 67 components (29.5 percent) required removal for various reasons. For an endoprosthesis, the most significant factor in determining the chances of success appeared to be the initial insertion diagnosis. Patients who received an endoprosthesis for an ailment which affected only the femoral side of the joint (such as traumatic fracture) had a much lower rate of failure than those patients with disease etiologies that could affect the acetabulum (such as osteoarthritis). The opposite was found for total hip prostheses. Of the 641 total hip devices inserted, 148 (23.0 percent) required removal. The highest rate of failure among these total hip components was for those devices inserted for trauma and the lowest rate of failure was for those inserted for osteoarthritis. Age at the time of insertion also proved to be of importance when estimating a hip component's chance of survival. For both endoprosthetic replacements and total hip arthroplasties, patients younger than 50 years of age at insertion experienced a failure rate almost twice that of those patients more than 50 years of age at insertion.

Hip Prosthesis↗