Kevin L. Garvin

New Definition for Periprosthetic Joint Infection: From the Workgroup of the Musculoskeletal Infection Society

Based on the proposed criteria, definite PJI exists when: (1) There is a sinus tract communicating with the prosthesis; or (2) A pathogen is isolated by culture from at least two separate tissue or fluid samples obtained from the affected prosthetic joint; or (3) Four of the following six criteria exist: (a) Elevated serum erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) concentration, (b) Elevated synovial leukocyte count, (c) Elevated synovial neutrophil percentage (PMN%), (d) Presence of purulence in the affected joint, (e) Isolation of a microorganism in one culture of periprosthetic tissue or fluid, or (f) Greater than five neutrophils per high-power field in five high-power fields observed from histologic analysis of periprosthetic tissue at ×400 magnification. PJI may be present if fewer than four of these criteria are met.

Ceramic-on-polyethylene bearing surfaces in total hip arthroplasty: Seventeen to twenty-one-year results

Background: Polyethylene wear debris, and the resulting inflammatory response leading to osteolysis and loosening, is the primary mode of failure limiting the longevity of total hip replacements. Alternative bearing surfaces, including ceramic-on-polyethylene, have been investigated in an effort to decrease the amount of polyethylene wear debris. The purpose of this study was to evaluate the seventeen to twenty-one-year results of the use of ceramic-on-polyethylene total hip prostheses. Methods: Sixty-four total hip prostheses were implanted with cement, by one surgeon, in fifty-six patients from 1978 to 1981. The average age at the index arthroplasty was sixty-nine years (range, fifty-one to eighty-four years). The components consisted of a cemented Charnley-Müller stem with a 32-mm modular alumina femoral head and a cemented all-polyethylene acetabular component. All patients who retained the index prosthesis were assessed clinically with use of Harris hip scores and were evaluated radiographically at the time of the latest follow-up. Results: At the time of this latest follow-up, of the original sixty-four implants, eighteen (28%) were still in place and five (8%) had been revised. The remaining forty-one implants were in patients who had died and were functioning well until the patient’s death. No patient was lost to follow-up. Of the eighteen hips with an intact prosthesis in the surviving patients, seven had an excellent clinical result; nine, a good result; and two, a fair result. One asymptomatic hip had definite radiographic evidence of femoral loosening. No hip had definite signs of acetabular loosening or evidence of osteolysis. Survivorship analysis revealed that the probability of survival of the prostheses without revision was 95% at five years, 95% at ten years, 89% at fifteen years, and 79% at twenty years. The mean linear and volumetric polyethylene wear rates were 0.034 mm/yr and 28 mm3/yr, respectively. There were no fractures of the ceramic heads. Conclusions: Outstanding long-term clinical and radiographic results were attained despite the use of what are now considered substandard techniques (an inferior stem design, a 32-mm head, and first-generation cementing techniques). The wear rates in this study are lower than previously reported metal-on-polyethylene wear rates and are consistent with the lowest reported in vivo ceramic-on-polyethylene wear rates. These findings support the consideration of ceramic-on-polyethylene bearing surfaces in total hip arthroplasty.

THE ROLE OF A COMPOSITE, DEMINERALIZED BONE MATRIX AND BONE MARROW IN THE TREATMENT OF OSSEOUS DEFECTS

The efficacy of demineralized bone matrix (DBM) used alone and with bone marrow as a graft material in the treatment of osseous defects was evaluated in 48 patients. Of these 48 patients, 39 were available to follow up and review. Follow up averaged 19 months for all patients. In the entire series, 30 of 39 patients demonstrated osseous union for a 77% success rate. Patients with fracture nonunion represented the most recalcitrant group clinically, with union achieved in only 61% of these cases. Overall, the 39 patients grafted with DBM demonstrated healing that was comparable to results achieved with standard iliac crest bone graft. The results indicate the DBM and marrow composite grafting is a suitable alternative to autologous iliac crest bone graft for use in certain clinical situations, such as bone defects in children, comminuted fractures with associated bone loss, nonunited fractures, or to augment an intended arthrodesis site.

Polylactide/polyglycolide antibiotic implants in the treatment of osteomyelitis. A canine model.

Osteomyelitis with Staphylococcus aureus was established in the tibiae of twenty-six adult mongrel dogs. After confirmation of infection at four weeks, all animals had operative débridement and were then divided into three treatment groups. Group 1 (eight animals [sixteen tibiae]) was treated with parenteral administration of gentamicin (three milligrams per kilogram of body weight per day) every eight hours for four weeks. Group 2 (nine animals [nine tibiae]) was treated with a polymethylmethacrylate implant containing 100 milligrams of gentamicin that was placed in the tibia for six weeks. Group 3 (nine animals [nine tibiae]) was treated with a polylactide/polyglycolide implant containing 100 milligrams of gentamicin that was placed in the tibia for six weeks. All animals were killed at the end of treatment. At that time, specimens of tissue were obtained for quantitative culture as well as for antibiotic immunoassay. In the groups that had been treated with an implant, serum was obtained for the measurement of serum drug levels after débridement; after the implantation; four, seven, and twenty-one days postoperatively; and immediately before the animals were killed. The infection was eradicated in ten of the sixteen tibiae in Group 1, in eight of the nine tibiae in Group 2, and in all nine tibiae in Group 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative autologous donation for total joint arthroplasty. An analysis of risk factors for allogenic transfusion.

Background: While autologous blood is commonly predonated to provide replacement of blood lost in orthopaedic procedures, few studies of patients managed with total joint replacement have addressed the problem of which patients are likely to benefit from an autologous blood-donation program. Methods: A retrospective analysis of 489 consecutive patients who had had a total joint arthroplasty was performed to identify the risk factors for allogenic transfusion and to further define the indications for preoperative autologous blood donation. The operations included 247 total knee replacements (157 unilateral primary, thirty-two revision, and twenty-nine one-stage bilateral primary procedures) and 271 total hip replacements (163 primary and 108 revision procedures). Fifty-four percent (264) of the 489 patients donated a total of 527 units of blood (average, 2.0 units per patient) preoperatively. Results: One hundred and ninety-one patients (39 percent) required a transfusion of autologous blood or allogenic blood, or both. One hundred and thirty-one patients (27 percent) received autologous blood, and eighty-two patients (17 percent) received a transfusion of allogenic blood; twenty-two patients (4 percent) received both autologous and allogenic blood. Neither form of transfusion caused serious complications. Fifty-six percent (295) of the 527 units of autologous blood were discarded. Autologous donation significantly decreased the requirements for allogenic transfusion (relative risk, 0.1; p < 0.0001). It also caused the level of hemoglobin to decrease an average of 12.2 grams per liter from the time before donation to the time before the operation (p < 0.0001). Factors that increased the risk for allogenic transfusion were a revision knee or hip procedure or a one-stage bilateral primary knee replacement (relative risk, 5.7; p < 0.0001), an initial hemoglobin level of less than 130 grams per liter (relative risk, 5.6; p < 0.0001), and an age of sixty-five years or older (relative risk, 2.8; p = 0.02). None of the sixty-seven patients who had a primary knee or hip arthroplasty and an initial hemoglobin level of 150 grams per liter or more required an allogenic transfusion. In addition, none of the sixty-three patients who had a primary arthroplasty, an initial hemoglobin level of between 130 and less than 150 grams per liter, and an age of less than sixty-five years required an allogenic transfusion. Eighty-three percent (115) of the 138 autologous units donated by the seventy patients in these two groups were discarded. These wasted units accounted for 39 percent of the 295 discarded units for the entire study sample. Conclusions: The efficiency of collection of autologous blood can be improved by identifying patients who have a very low risk of transfusion according to the type of arthroplasty, the initial level of hemoglobin, and age. Patients who have an initial hemoglobin level of at least 150 grams per liter or an initial hemoglobin level of between 130 and 150 grams per liter and an age of less than sixty-five years have a minimal risk of needing a transfusion during or after a primary total joint replacement. These patients should be apprised of their low risk so that they can make an informed decision regarding preoperative autologous donation.

Two-stage reimplantation of total joint infections: a comparison of resistant and non-resistant organisms.

The prevalence of resistant organisms has increased throughout the last decade. In order to determine best treatment strategies, studies on reimplantation must address this population. The purpose of this study is to compare the results of delayed reconstruction for total joint infections caused by methicillin-sensitive and methicillin-resistant organisms. This investigation included 46 patients (21 men, 25 women) with an average age 67 years (range, 36–86 years) who had a two-staged reimplantation after periprosthetic total joint infection. Thirty-seven patients cultured methicillin-sensitive organisms and nine cultured methicillin-resistant organisms. Treatment included resection, aggressive debridement, 6 weeks of parenteral antibiotics, and subsequent debridement and reimplantation. Treatment was considered successful if the patient was disease free at last followup (average 5 years, range 2–10 years). The efficacy of two-stage reconstruction was similar for infections with sensitive and resistant bacteria. Only 3 of 46 patients failed delayed reconstruction requiring further treatment. Failure rates with regards to infections with sensitive bacteria were 5.4% (2 of 37 infections) and resistant bacteria 11.1% (1 of 9 infections), which was not significant. The current study shows clinical success of two-stage reimplantation for patients with methicillin-resistant bacteria complicating total joint arthroplasty.

Palacos gentamicin for the treatment of deep periprosthetic hip infections

Between 1983 and 1986, 40 hip arthroplasties in 40 patients with documented deep infection were reimplanted using Palacos Gentamicin at The Hospital for Special Surgery. Palacos Gentamicin was added to the standard protocol, which included removal of the prosthesis, cement, if present, and a thorough debridement of infected and necrotic tissue, six weeks of intravenous antibiotics with a postpeak serum bactericidal titer of at least 1:8 against the infecting bacteria, followed by reimplantation of the hip. Sixteen of the patients also had the placement of gentamicin-impregnated beads at the time of prosthetic removal. All patients had a deep periprosthetic infection, 13 with Staphylococcus epidermidis, seven Staphylococcus aureus, four Streptococcus, three Enterococcus, three with gram-positive bacteria, four Escherichia coli, two Proteus, one Pseudomonas, and three anaerobic organisms. At an average follow-up period of five years (range, two to ten), two of the 40 hips (5%) developed recurrent infection. These cases recurred at one month in a patient immunocompromised by end-stage systemic lupus erythematosus (S. epidermidis) and at five months in a patient with severe titanium metallosis (S. aureus). No recurrence was noted in eight cases with gram-negative organisms or in three cases of mixed infections. No infection recurred after five months in the remaining patients before their death or last follow-up examination. Of the remaining 38 hips, 16 died of causes unrelated to the hip, leaving 21 with an average follow-up period of 7.5 years. Clinical results in these patients were 14 excellent, five good, two fair, and no poor results.(ABSTRACT TRUNCATED AT 250 WORDS)

Infection following total knee arthroplasty: prevention and management.

Despite diligent efforts to prevent infection, prosthetic knee infection occurs in up to 2% of patients treated with total knee arthroplasty. Although the risk of infection is relatively low, the effects are considerable. The number of total knee arthroplasties is projected to increase by more than 600% by 2030, resulting in 3.48 million knee replacements, with a possible 70,000 prosthetic knee infections. Infection will be the most common indication for revision total knee arthroplasty. Prophylactic antibiotics and minimizing patient risk factors are critical in preventing infections. Staphylococcus is the most common organism in infected total knee arthroplasties. Prompt diagnosis and treatment are crucial to the long-term outcomes of patients with prosthetic joint infections. The erythrocyte sedimentation rate, C-reactive protein level, and interleukin-6 serum level should be checked in all patients with clinical signs of infection or unexplained pain or stiffness. The surgical management of a prosthetic knee infection depends on several factors, but none is more important than the timing of infection in relationship to the index surgery. With a success rate of 80% to 90%, two-stage component exchange remains the treatment of choice for chronically infected total knee arthroplasties.

Arthrodesis of the Knee with a Modular Titanium Intramedullary Nail

We retrospectively studied the results of arthrodesis of the knee with a modular titanium intramedullary nail that couples at the knee. The study group consisted of thirteen patients who had a malignant tumor around the knee, five who had failure of a total knee arthroplasty, and three who had a locally destructive benign tumor about the knee. All of the patients were followed for a minimum of two years. Through a single incision at the knee, one nail was inserted retrograde into the femur and the other, antegrade into the tibia; the two nails were joined at the level of the knee by a conical couple and were secured with locking screws. The diameters of the nails were different, to accommodate the dissimilar sizes of the tibial and femoral intramedullary canals. A solid osseous fusion was achieved in nineteen (90 per cent) of the twenty-one patients (sixteen who had had resection of a tumor and three who had had a failed arthroplasty), at an average of 8.4 months (range, three to nineteen months) after the operation. One patient had a delayed union, but fusion was achieved after additional bone-grafting. Of the sixteen patients who were available for clinical and radiographic evaluation at the time of the study, fifteen were satisfied with the over-all outcome and thirteen had either less pain or the same amount of pain as they had had preoperatively. There were no mechanical failures of the implant and no recurrences of tumor. Complications occurred in eight (38 per cent) of the twenty-one patients: three patients had a stress fracture, three had a peroneal nerve palsy (one of which was transient), one had a superficial wound infection, and one had reflex sympathetic dystrophy.

Dealing with complications: Neurovascular complications associated with total hip arthroplasty

BACKGROUND The treatment of unstable thoracolumbar burst fractures with short-segment posterior spinal instrumentation without anterior column reconstruction is associated with a high rate of screw breakage and progressive loss of reduction. The purpose of the present study was to evaluate the functional, neurologic, and radiographic results following transpedicular, balloon-assisted fracture reduction with anterior column reconstruction with use of calcium phosphate bone cement combined with short-segment posterior instrumentation and a laminectomy. METHODS A consecutive series of thirty-eight patients with an unstable thoracolumbar burst fracture with or without neurologic deficit were managed with transpedicular, balloon-assisted fracture reduction, calcium phosphate bone cement reconstruction, and short-segment spinal instrumentation from 2002 to 2005. Twenty-eight of the thirty-eight patients were followed for a minimum of two years. Demographic data, neurologic function, segmental kyphosis, the fracture severity score, canal compromise, the Short Form-36 score, the Oswestry Disability Index score, and treatment-related complications were evaluated prospectively. RESULTS All thirteen patients with incomplete neurologic deficits had improvement by at least one Frankel grade. The mean kyphotic angulation improved from 17 degrees preoperatively to 7 degrees at the time of the latest follow-up, and the loss of vertebral body height improved from a mean of 42% preoperatively to 14% at the time of the latest follow-up. Screw breakage occurred in two patients, and pseudarthrosis occurred in one patient. CONCLUSIONS The present study demonstrates that excellent reduction of unstable thoracolumbar burst fractures with and without associated neurologic deficits can be maintained with use of short-segment instrumentation and a transpedicular balloon-assisted reduction combined with anterior column reconstruction with calcium phosphate bone cement performed through a single posterior incision. The resultant circumferential stabilization combined with a decompressive laminectomy led to maintained or improved neurologic function in all patients with neurologic deficits, with a low rate of instrumentation failure and loss of correction.