Martin F. Hoffmann

Outcome of periprosthetic distal femoral fractures following knee arthroplasty.

INTRODUCTION The majority of periprosthetic fractures around the knee occur at the supracondylar region of the distal femur. Fixation of distal femoral fractures in osteoporotic bone with short segment remains a challenge, especially after total knee arthroplasty (TKA). Internal fixation of these fractures using locking plates has become popular. The purpose of this study was to evaluate a consecutive series of periprosthetic supracondylar femoral fractures treated with locked periarticular plate fixation with regard to surgical procedure, complications and clinical outcome. MATERIALS AND METHODS From two academic trauma centres, 55 consecutive periprosthetic distal femoral fractures (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association, AO/OTA 33) were retrospectively identified as having been treated with locked plate fixation. Of these, 36 fractures in 35 patients (86.1% female) met the inclusion criteria. Patients had an average age of 73.2 years (range 54-95 years). Fixation constructs for plate length and working length were delineated. Nonunion, infection and implant failure were used as complication variables. Demographics were assessed. Outcome was addressed radiographically and clinically according to Kristensen et al.(1) by range of motion and pain. RESULTS Twenty-five of 36 fractures (69.4%) healed after the index procedure. Eight of 36 fractures (22.2%) developed a nonunion with three fractures (8.3%) leading to hardware failure. Nine of the 36 patients (25%) were radiographically diagnosed with notching of the anterior femoral cortex. Regarding technical aspects, distance from the anterior flange of the femoral component to fracture was significantly shorter in patients with compared to without anterior notching (t=3.68, p=0.02). Patients who underwent submuscular plate insertion compared to an extensive lateral approach had a reduced nonunion risk (χ(2)=0.05). No difference in infection rate was found for submuscular procedures compared with open procedures (χ(2)=0.85). Range of motion was reduced in most of the patients and 13.5% had a persistent loss of extension of 5°. More than 77% of the patients reported no or only mild pain during the last office visit. Range of motion loss did not influence pain. Successful treatment according to Cain et al.(2) was achieved in 83%. Using Kristensens(1) criteria, 56% of the knees had acceptable flexion. CONCLUSION Operative fixation of periprosthetic distal femoral fractures after TKA continues to be challenging. Notching of the anterior femoral cortex should be avoided. Loss of reduction and high failure rates still occur with locked plating and may be related to underlying factors. Indirect reduction and submuscular plate insertion technique reduce nonunion risk.

Clinical outcomes of locked plating of distal femoral fractures in a retrospective cohort

PurposeLocked plating (LP) of distal femoral fractures has become very popular. Despite technique suggestions from anecdotal and some early reports, knowledge about risk factors for failure, nonunion (NU), and revision is limited. The purpose of this study was to analyze the complications and clinical outcomes of LP treatment for distal femoral fractures.Materials and methodsFrom two trauma centers, 243 consecutive surgically treated distal femoral fractures (AO/OTA 33) were retrospectively identified. Of these, 111 fractures in 106 patients (53.8% female) underwent locked plate fixation. They had an average age of 54 years (range 18 to 95 years): 34.2% were obese, 18.9% were smokers, and 18.9% were diabetic. Open fractures were present in 40.5% with 79.5% Gustilo type III. Fixation constructs for plate length, working length, and screw concentration were delineated. Nonunion and/or infection, and implant failure were used as outcome complication variables. Outcome was based on surgical method and addressed according to Pritchett for reduction, range of motion, and pain.ResultsEighty-three (74.8%) of the fractures healed after the index procedure. Twenty (18.0%) of the patients developed a NU. Four of 20 (20%) resulted in a recalcitrant NU. Length of comminution did not correlate to NU (p = 0.180). Closed injuries had a higher tendency to heal after the index procedure than open injuries (p = 0.057). Closed and minimally open (Gustilo/Anderson types I and II) fractures healed at a significantly higher rate after the index procedure compared to type III open fractures (80.0% versus 61.3%, p = 0.041). Eleven fractures (9.9%) developed hardware failure. Fewer nonunions were found in the submuscular group (10.7%) compared to open reduction (32.0%) (p = 0.023). Fractures above total knee arthroplasties had a significantly greater rate of failed hardware (p = 0.040) and worse clinical outcome according to Pritchett (p = 0.040). Loss of fixation was related to pain (F = 3.19, p = 0.046) and a tendency to worse outcome (F = 2.43, p = 0.071). No relationship was found between nonunion and working length.ConclusionDespite modern fixation techniques, distal femoral fractures often result in persistent disability and worse clinical outcomes. Soft tissue management seems to be important. Submuscular plate insertion reduced the nonunion rate. Preexisting total knee arthroplasty increased the risk of hardware failure. Further studies determining factors that improve outcome are warranted.

Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) in posterolateral lumbar spine fusion: complications in the elderly

Study designRetrospective cohort study of 1430 patients undergoing lumbar spinal fusion from 2002 - 2009. Objective: The goal of this study was to compare and evaluate the number of complications requiring reoperation in elderly versus younger patients.Summary of background datarhBMP-2 has been utilized off label for instrumented lumbar posterolateral fusions for many years. Many series have demonstrated predictable healing rates and reoperations. Varying complication rates in elderly patients have been reported.Materials and methodsAll patients undergoing instrumented lumbar posterolateral fusion of ≤ 3 levels consenting to utilization of rhBMP-2 were retrospectively evaluated. Patient demographics, body mass index, comorbidities, number of levels, associated interbody fusion, and types of bone void filler were analyzed. The age of patients were divided into less than 65 and greater than or equal to 65 years. Complications related to the performed procedure were recorded.ResultsAfter exclusions, 482 consecutive patients were evaluated with 42.1% males and 57.9% females. Average age was 62 years with 250 (51.9%) < 65 and 232 (48.1%) ≥ 65 years. Patients ≥ 65 years of age stayed longer (5.0 days) in the hospital than younger patients (4.5 days) (p=0.005).Complications requiring reoperation were: acute seroma formation requiring decompression 15/482, 3.1%, bone overgrowth 4/482, 0.8%, infection requiring debridement 11/482, 2.3%, and revision fusion for symptomatic nonunion 18/482, 3.7%. No significant differences in complications were diagnosed between the two age groups. Statistical differences were noted between the age groups for medical comorbidities and surgical procedures. Patients older than 65 years underwent longer fusions (2.1 versus 1.7 levels, p=0.001).DiscussionDespite being older and having more comorbidities, elderly patients have similar complication and reoperation rates compared to younger healthier patients undergoing instrumented lumbar decompression fusions with rhBMP-2.

Complications of rhBMP-2 utilization for posterolateral lumbar fusions requiring reoperation: a single practice, retrospective case series report

BACKGROUND CONTEXT Recombinant human bone morphogenetic protein-2 (rhBMP-2) (INFUSE, Medtronic, Memphis, TN, USA) has been used off-label for posterolateral lumbar fusions for many years. PURPOSE The goal of this study was to evaluate the complications requiring reoperation associated with rhBMP-2 application for posterolateral lumbar fusions. STUDY DESIGN/SETTING During a 7-year period of time (2002-2009), all patients undergoing lumbar posterolateral fusion using rhBMP-2 (INFUSE) were retrospectively evaluated within a large orthopedic surgery private practice. PATIENT SAMPLE A total of 1,158 consecutive patients were evaluated with 468 (40.4%) males and 690 (59.6%) females. OUTCOME MEASURES Complications related to rhBMP were defined as reoperation secondary to symptomatic failed fusion (nonunion), symptomatic seroma formation, symptomatic reformation of foraminal bone, and infection. METHODS Inclusion criteria were posterolateral fusion with rhBMP-2 implant and age equal to or older than 18 years. Surgical indications and treatment were performed in accordance with the surgeons best knowledge, discretion, and experience. Patients consented to lumbar decompression and arthrodesis using rhBMP-2. All patients were educated and informed of the off-label utilization of rhBMP-2. Patient follow-up was performed at regular intervals of 2 weeks, 6 weeks, 12 weeks, 6 months, 1 year, and later if required or indicated. RESULTS Average age was 59.2 years, and body mass index was 30.7 kg/m². Numbers of levels fused were 1 (414, 35.8%), 2 (469, 40.5%), 3 (162, 14.0%), 4 (70, 6.0%), 5 (19, 1.6%), 6 (11, 0.9%), 7 (7, 0.6%), 8 (4, 0.3%), and 9 (2, 0.2%). Patients having complications requiring reoperation were 117 of 1,158 (10.1%): symptomatic nonunion requiring redo fusion and instrumentation 41 (3.5%), seroma with acute neural compression 32 (2.8%), excess bone formation with delayed neural compression 4 (0.3%), and infection requiring debridement 26 (2.2%). Nonunion was related to male sex and previous BMP exposure. Seroma formation was significantly higher in patients with higher doses of rhBMP-2 (p=.050) and with more than 12 mg of rhBMP-2 (χ(2)=0.025). Bone reformation and neural compression at the laminectomy and foraminotomy sites occurred in a delayed fashion. Infection was associated with obesity and respiratory disease. Infections were noted with a greater BMP dose (p<.001), more than 12 mg (χ(2)<0.001), fusion more than three levels (χ(2)<0.001), and reexposed to BMP (χ(2)=0.023). CONCLUSIONS rhBMP-2 utilization for posterolateral lumbar fusions has a low symptomatic nonunion rate. Prior rhBMP-2 exposure and male sex were related to symptomatic nonunion formation. rhBMP-2-associated neural compression acutely with seroma formation and delayed with foraminal bone formation is concerning and associated with higher rhBMP-2 concentrations.

Results of anterior-inferior 2.7-mm dynamic compression plate fixation of midshaft clavicular fractures.

Objectives: To evaluate the outcome of operatively treated unstable displaced diaphyseal clavicle fractures with anterior–inferior 2.7-mm dynamic compression plate (DCP) fixation. Design: Retrospective review of clavicle fractures. Setting: Level-1 trauma teaching center. Patients/Participants: One hundred twenty-nine clavicle fractures. Intervention: An anterior–inferior approach to clavicle fractures was used with the application of a 2.7-mm DCPs. Main Outcome Measurement: Radiographic assessment of healing and complication rates. Results: One hundred twenty-five fractures healed (97%). Postoperative complications included 1 superficial wound problem, 3 deep wound problems, 5 nonunions, and 4 prominent implants requiring removal in 3. Conclusions: Anterior–inferior placement of 2.7-mm DCPs seems safe and is associated with minimal complications. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Fate of patients with a "Surprise" positive culture after nonunion surgery

Objective: Review the impact of unexpected positive cultures from definitive surgery for nonunion regarding postoperative treatment and ultimate result. Designs: Retrospective multicenter case series. Setting: Three level-one trauma centers. Patients: Six-hundred sixty-six consecutive nonunions were treated during the study period. Four-hundred fifty-three cases (68%) were considered at risk for indolent infection (prior open fracture, surgery, or infection) and had cultures taken at the time of definitive surgery. Intervention: Intraoperative cultures during definitive operative treatment of nonunions. Main Outcome Measurement: The incidence of “surprise” positive cultures was determined, and the course of the patients was documented including the use of antibiotics, surgery performed, and the outcome regarding infection and union. Results: Ninety-one (20%) cases had a surprise positive culture despite negative inflammatory markers. Most of bacteria isolated from the cultures were Staphylococcus species. Eight (9%) of the ninety-one cultures were considered probable contaminants and no antibiotics were given, 5 of these patients healed. The other 83 patients were treated with antibiotics, initially 66 (80%) healed and 12 (14%) remained infected. Eighty-two percent of patients with augmentation healed as compared with 86% of those not grafted. Conclusions: The treatment of nonunions is challenging, and in patients with a history of surgery or open fracture, we found that 20% had positive intraoperative cultures from the definitive surgery. We recommend intraoperative cultures for all patients undergoing revision surgery. The use of culture-specific antibiotics is justified based on the overall low rate of infection in this complex population and the high rate of chronic infection (25%) for those treated as contaminants. Patients may be counseled that a positive culture after nonunion surgery is a treatable problem but does increase the risk of infection and additional surgery as compared with those with a negative intraoperative culture. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Determination of sagittal alignment measurements in distal femurs.

Objective: Open reduction and internal fixation is presently the treatment of choice for distal femur fractures. Anatomic reconstruction of the articular surface and restoration of biomechanical relations to the diaphysis are desired. A method to determine sagittal alignment on plain radiographs is warranted. Methods: Consecutive adult, normal, distal femur/knee, plain lateral radiographs and scanned and digitalized cadaveric distal femurs were analyzed. Measurement of 7 different angles was performed. Results: Ninety-four adults [39 men (41.5%) and 55 women (58.5%)] with a mean age of 54 years (range, 18–92 years) and body mass index (BMI) of 29.7 kg/m2 (range, 16.6–47.2 kg/m2), as well and 35 cadaveric femora [24 men (68.6%) and 11 women (31.4%)] with a mean age of 53 years (25–85 years) and BMI of 29.8 kg/m2 (17.7–53.3 kg/m2) were studied. Twenty-two of the patients (23.4%) had radiographic findings of arthrosis. If arthrosis was diagnosed, measurements including the proximal rim of the articular surface were significantly greater (P = 0.001). Two angles were significantly smaller in women (P < 0.05). No significant differences in any measurement for age or BMI were recorded. Conclusions: The necessity for reliability and quality of intraoperative and postoperative radiographic controls of the obtained fracture reduction, implant insertion, and final healed fracture increases with popularity of less invasive indirect reduction and stabilization methods. The ability to obtain exact sagittal alignment measurements has been problematic with other studies. Two different and reliable methods of measuring sagittal plane anatomy and measurements independent of implants were confirmed using plain radiographic images.