Bryan D. Springer

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.

Systemic safety of high-dose antibiotic-loaded cement spacers after resection of an infected total knee arthroplasty

The purpose of this study was to assess the systemic safety and potential adverse effects of using a high-dose antibiotic-impregnated cement spacer after resection arthroplasty of an infected total knee replacement. Between October 2000 and December 2002, 36 knees (34 patients) had a resection arthroplasty of an infected total knee prosthesis with placement of a high-dose antibiotic impregnated cement spacer. There were 24 men and 10 women with a mean age of 66.5 years (range, 48–84 years). All spacers placed contained an average of 3.4 batches of cement with an average total dose of 10.5 g of vancomycin (range, 3–16 g) and 12.5 g of gentamicin (range, 3.6–19.2 g). All patients were followed up postoperatively until reimplantation for evidence of renal failure. The preoperative creatinine ranged from 0.7 to 1.8 mg/dL. All patients were concomitantly treated with 6 weeks of intravenous organism-specific antibiotics. One patient with normal preoperative renal function (Cr 0.7 mg/dL) had a perioperative 1-day transient rise in serum creatinine (1.7 mg/dL) postoperatively that subsequently normalized. No patients showed any clinical evidence of acute renal insufficiency, failure, or other systemic side effects of the antibiotics. Treatment of patients with an infected total knee arthroplasty with high-dose vancomycin and gentamicin antibiotic spacers seems to be clinically safe.

Motor Nerve Palsy Following Primary Total Hip Arthroplasty

BACKGROUND Nerve palsy is a potentially devastating complication following total hip arthroplasty. The purpose of this study was to retrospectively identify risk factors for, and the prognosis associated with, a motor nerve palsy following primary total hip arthroplasty. METHODS Between 1970 and 2000, 27,004 primary total hip arthroplasties were performed at our institution. Forty-seven patients (0.17%) with postoperative motor nerve dysfunction were identified by a review of the complications log of a total joint database. The medical record of each patient provided the data for this study. The average age of the patients was fifty-seven years at the time of surgery. The patients had serial clinical examinations for a minimum of two years, or until neurologic recovery or death. The nerve palsies were classified as complete or incomplete, and only patients with objective motor weakness were included in the study. The limb lengths were measured on preoperative and postoperative radiographs, and those data were then compared with the limb lengths in a matched cohort of patients who had not sustained a nerve injury after a primary total hip arthroplasty. The extent of neurologic recovery, the need for braces or walking aids, and the use of medications for neurogenic pain were evaluated. RESULTS There were twenty-nine complete motor nerve palsies (sixteen peroneal, eleven sciatic, and two femoral) and eighteen incomplete motor nerve palsies (fourteen peroneal, three sciatic, and one femoral). A preoperative diagnosis of developmental dysplasia of the hip (p = 0.0004) or posttraumatic arthritis (p = 0.01), the use of a posterior approach (p = 0.032), lengthening of the extremity (p < 0.01), and cementless femoral fixation (p = 0.03) were associated with a significantly increased odds ratio for the development of a postoperative motor nerve palsy. Of the twenty-eight patients with a complete palsy who were available for follow-up, only ten (36%) had complete recovery of motor strength, which took an average of 21.1 months. Seven of the eighteen patients with an incomplete palsy fully recovered their preoperative strength. Twenty-one patients required walking aids, and fifteen required permanent use of an ankle-foot orthosis. Five patients required daily medication for chronic neurogenic pain. CONCLUSIONS Motor nerve palsy is uncommon following primary total hip arthroplasty. A preoperative diagnosis of developmental dysplasia of the hip or posttraumatic arthritis, the use of a posterior approach, lengthening of the extremity, and use of an uncemented femoral implant increased the odds ratio of sustaining a motor nerve palsy. The majority of the motor nerve deficits in our series, whether complete or incomplete, did not fully resolve.

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.

The Kinematic Rotating hinge prosthesis for complex knee arthroplasty

Fifty-eight patients (69 knees) treated with the Kinematic Rotating Hinged knee prosthesis for complex primary and salvage revision total knee arthroplasty were followed up for an average of 75.2 months (range, 24–199 months). The indications for use of the Kinematic Rotating Hinged knee prosthesis included severe bone loss combined with ligamentous instability (30 knees), nonunion of a periprosthetic fracture (10 knees), an acute periprosthetic fracture (nine knees), severe collateral ligamentous instability (five knees), reimplantation for infection (six knees), nonunion of a supracondylar femoral fracture (four knees), congenital dislocation of the knee (three knees), and treatment of a severely comminuted distal femur (two knees). At the time of surgery, the average patient age was 72 years (range, 46–92 years). Preoperatively, knee extension averaged 4.94° (range, 0°–40°) and flexion averaged 81° (range, 15°–125°). At final followup, knee extension averaged 1.25° (range, −5°–25°) and flexion averaged 94.2° (range, 5°–125°). The preoperative Knee Society Knee score averaged 40.3 points (range, 2–93 points) and improved to 77 points (range, 33–99 points) at final followup. Complications were numerous: 23 (32%) patients experienced at least one complication and 12 (17%) patients had two or more complications. Deep periprosthetic infection was the most common complication (14.5%), followed by patellar complications (13%), and prosthetic component breakage (10%). During the period of this study, there were 15,798 primary and 2673 revision total knee arthroplasties done at the authors’ institution. The patients receiving a Kinematic Rotating Hinged knee prosthesis represent a highly complex and small subset (0.37%) of the overall population having knee arthroplasty. Although the use of the Kinematic Rotating Hinged knee prosthesis for these limited indications has been useful for the authors, the incidence of complications and the poor outcome of these complications is disconcerting. Hinged total knee arthroplasty should be reserved for the final salvage option of the treatment options available when doing complex primary and salvage revision knee arthroplasties.

The modular segmental kinematic rotating hinge for nonneoplastic limb salvage.

From January 1980 to July 1998, 25 patients (26 knees) were treated with an arthroplasty using a Modular Segmental Kinematic Rotating Hinge total knee prosthesis for nonneoplastic limb salvage. The indications included: nonunion of a periprosthetic femur fracture (11 knees), severe bone loss and ligamentous instability (eight knees), nonunion of a supracondylar femur fracture (four knees), acute periprosthetic fracture (one knee), fracture of a previous hinge (one knee), and prior resection arthroplasty (one knee). The average age of the patients was 72.3 years. Twenty-two arthroplasties were revisions. The average followup was 58.5 months. At the latest followup, knee extension averaged 2.4° and flexion averaged 93.6°. The Knee Society knee score improved from an average of 45.4 preoperatively to 75.5. Preoperatively, functional scores averaged 8.6 and improved to 25. Complications occurred in eight patients. The most common was deep infection (five patients). The use of the Modular Kinematic Rotating Hinge for nonneoplastic limb salvage represents a small proportion (0.14%) of all primary and revision knee arthroplasties done at our institution. The indications for the surgery are for a highly complex and small subset of patients. The patients in the current study gained significant improvement in overall range of motion, Knee Society knee scores, and functional scores when this prosthesis was used.

Conversion of failed unicompartmental knee arthroplasty to TKA.

As the number of unicompartmental knee arthroplasties performed continues to rise, so too will the number of failures. In order to justify its continued use, conversion to total knee arthroplasty must be evaluated. From 1993-2004, 22 consecutive knees from 18 patients with a failed unicondylar knee arthroplasty underwent conversion to total knee arthroplasty. The most common modes of failure were polyethylene wear (12 patients), loosening of the femoral (4 patients) or tibial component (3 patients), and osteoarthritis progression (3 patients). All patients were converted to primary cruciate retaining components. Twenty-seven percent of patients had contained defects on the femoral condyle that required bone graft. No femoral stems or metal augmentation were required. Forty-five percent of patients had contained defects on the tibia that required bone graft. Metal wedge augmentation was required in five knees (23%), and stems were used in two patients. Sixteen of 22 knees (73%) were followed for an average of 64.5 months. Knee Society knee scores and functional scores at latest followup were 93 and 78, respectively. Conversion of a failed unicondylar knee arthroplasty to a total knee arthroplasty is technically demanding, but may be done successfully with careful preoperative planning and possible need for revision techniques.Level of Evidence: Therapeutic study, level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Microbiological, clinical, and surgical features of fungal prosthetic joint infections: a multi-institutional experience.

Periprosthetic joint infection is one of the most dreaded and complex complications of total joint arthroplasty. Periprosthetic joint infection is now the major cause of failure following total knee arthroplasty1 and the third most common cause of failure following total hip arthroplasty2. It is estimated that the prevalence of periprosthetic joint infection may be on the rise3. A wide variety of pathogens are known to cause periprosthetic joint infection, with the majority of infections being caused by gram-positive bacteria, especially staphylococcal species4,5. The treatment of a confirmed periprosthetic joint infection often includes the need for surgical intervention, and two-stage exchange arthroplasty is the most common mode of surgical treatment in North America. Two-stage exchange arthroplasty relies on removal of all foreign material and insertion of an antibiotic-impregnated cement spacer for the purpose of delivering high doses of antibiotics locally in the interval of time between the resection arthroplasty and subsequent reimplantation. Periprosthetic infection with fungi, although rare, represents a diagnostic and therapeutic challenge to which clear guidelines have not yet been established. It is not known if the protocol for treatment of a bacterial periprosthetic joint infection can also be applied in the same manner to fungal infections. Patients with fungal periprosthetic joint infection are believed to be a different type of host with decreased cellular immunity, mostly due to an underlying cause of immunosuppression, such as malignant disease, drug therapies (antineoplastic agents, corticosteroids, or immunosuppressive drugs), overuse or inappropriate use of antibiotics, and indwelling catheters (urinary or parenteral hyperalimentation). Other factors, such as diabetes, tuberculosis, intravenous drug use, and acquired immunosuppressive disease, are associated with an increased frequency of mycotic infection6. The lack of reliable antifungal medications for systemic and, in particular, local delivery poses a real challenge …

Extensor Mechanism Allograft Reconstruction After Total Knee Arthroplasty

Disruption of the extensor mechanism is an infrequent but catastrophic complication after total knee arthroplasty. Treatment is technically challenging. For patellar tendon ruptures, multiple treatment options having been described with inconsistent results. Allograft tissue may provide the best means to adequately reconstruct the disrupted patellar tendon. Options for allograft reconstruction include an Achilles tendon bone block allograft or a whole extensor mechanism allograft. Important surgical principals include rigid fixation of the host allograft junction, coverage of the allograft tissue with as much autogenous tissue as possible to reduce the risk of infection, tensioning the graft in full extension, and not testing the completed repair is crucial. Current results with proper surgical technique show acceptable functional outcome for this devastating complication.

Why Do Revision Knee Arthroplasties Fail

This study identified the mechanisms of failure and the variables associated with failure after revision knee arthroplasty. Five hundred sixty-six index revision knee arthroplasties were studied. Of index revisions, 12.0% failed at an average of 40.1 months. Predominant revision failure modes included infection (46%), aseptic loosening (19%), and instability (13%). Only 4.3% of knees revised for aseptic loosening required rerevision as compared to 21% of knees revised for infection. Revision knee arthroplasty was more likely to fail in younger patients and in those who underwent polyethylene exchanges. Mechanisms of failure for revision arthroplasties are different than for primary knee arthroplasties. Revisions for infection are 4 times more likely to fail than revisions for aseptic loosening. The survivorship for the entire cohort, with revision for any reason as an end point, was 82% at 12 years.